Heat exchanger tube inserting apparatus

A heat exchanger tube inserting apparatus includes a roller conveyor section and a pushing section. The roller conveyor section includes a roller that advances the heat exchanger tube to thereby insert the heat exchanger tube into the insertion holes of the fins and to a first position by rotation of the roller. The pushing section pushes the heat exchanger tube, which has been moved to the first position by the roller conveyor section, to a second position located further inside than the first position.

CROSS-REFERENCE TO RELATED APPLICATIONS

This U.S. National stage application claims priority under 35 U.S.C. §119(a) to Japanese Patent Application No. 2013-017752, filed in Japan on Jan. 31, 2013, the entire contents of which are hereby incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to a heat exchanger tube inserting apparatus for inserting a heat exchanger tube for a heat exchanger into a fin.

BACKGROUND ART

Conventionally, a heat exchanger tube inserting apparatus is used for inserting, in a process of manufacturing a heat exchanger, a heat exchanger tube successively into insertion holes formed in each of a number of fins which have laminated so that the heat exchanger tube passes through the number of fins. For example, a heat exchanger tube inserting apparatus disclosed in Japanese Unexamined Patent Publication No. HEI 9-108760 includes guide rods respectively supporting a pair of leading ends of a U-shaped heat exchanger tube, and a heat exchanger tube inserting means for inserting the heat exchanger tube into insertion holes of a fin by pushing the curved portion of the U-shaped heat exchanger tube.

Each of the guide rods has a streamlined head at its leading end and is long enough to be inserted into insertion holes of each fin so as to pass through the number of fins. The streamlined heads located at the respective leading ends of the guide rods support the pair of leading ends of a heat exchanger tube while respectively being inserted in the opening formed at each of the pair of leading ends of the heat exchanger tube. Further, the guide rods can move through insertion holes of fins. This allows the guide rods to guide a heat exchanger tube to inner insertion holes while supporting the heat exchanger tube in insertion holes of the number of fins.

The heat exchanger tube inserting means is disposed at a position opposite to the guide rods in a direction of lamination of the number of fins. The heat exchanger tube inserting means can insert a U-shaped heat exchanger tube successively into insertion holes formed in each of the number of fins by pushing the curved portion of the heat exchanger tube toward the guide rods.

In such apparatus, the guide rods are inserted into insertion holes of the number of fins, in advance. Subsequently, the pair of leading ends of a heat exchanger tube is supported on the streamlined heads located at the respective leading ends of the guide rods. In this state, the curved portion of the heat exchanger tube is pushed by the heat exchanger tube inserting means from the side opposite to the guide rods, whereby the heat exchanger tube is inserted into the insertion holes of each of the fins. At this time, the guide rods are retreated at the same speed as an advancing speed of the heat exchanger tube, thereby allowing the heat exchanger tube to be inserted into the insertion holes of each of the number of fins while being supported by the guide rods.

However, in the above-described heat exchanger tube inserting apparatus, the guide rods and the heat exchanger tube inserting means which are long are disposed respectively on the opposite sides of the assembly of the number of fins in the direction of lamination. This results in an overall large size of the apparatus. Specifically, the guide rods need to be long enough to pass through the number of fins. Further, the heat exchanger tube inserting means needs to be long (have a stroke length) enough to push a heat exchanger tube from the beginning to the end in the insertion process of the heat exchanger tube. Therefore, the total length of the heat exchanger tube inserting apparatus needs to include not only the thickness of lamination of the number of fins, but also the full length of a heat exchanger tube at each of both sides of the assembly of fins in the direction of lamination. This results in a large size of the heat exchanger tube inserting apparatus. Therefore, it is difficult to make the apparatus smaller.

Furthermore, in the above-described heat exchanger tube inserting apparatus, the length of the guide rods and the stroke length of the heat exchanger tube inserting means limit the length of a heat exchanger tube that can be inserted. Therefore, there is a problem that the apparatus is not applicable to heat exchanger tubes having different lengths. In particular, there is a problem that the apparatus cannot insert an extremely long heat exchanger tube having a length exceeding the sum of the length of the guide rods and the stroke length of the heat exchanger tube inserting means.

SUMMARY

The present invention has been made in view of the above-mentioned problems and has an object of providing a heat exchanger tube inserting apparatus which is small in size and applicable to heat exchanger tubes having different lengths.

A heat exchanger tube inserting apparatus according to the present invention is a heat exchanger tube inserting apparatus for inserting, in a process of assembling a heat exchanger including a number of fins and heat exchanger tubes passing through the number of fins, a heat exchanger tube into insertion holes formed in the fins comprising: a roller conveyor section including a roller for advancing the heat exchanger tube to thereby insert the heat exchanger tube into the insertion holes of the fins and to a first position by rotation of the roller; and a pushing section for pushing the heat exchanger tube which has been moved to the first position by the roller conveyor section to a second position located further inside than the first position.

DESCRIPTION OF EMBODIMENTS

In the following, a heat exchanger tube inserting apparatus according to an embodiment of the present invention will be further described in detail with reference to the accompanying drawings.

First Embodiment

A heat exchanger tube inserting apparatus1according to a first embodiment inserts, in a process of assembling a heat exchanger E shown inFIGS. 1 and 2, i.e. a heat exchanger E including a number of fins F and hairpin tubes T passing through the number of fins F as heat exchanger tubes, hairpin tubes T into insertion holes P formed in each fin F. Here, the hairpin tube T refers to a pipe including a pair of straight tube portions SP extending in parallel to each other and a hairpin portion HP connecting respective one ends of the pair of straight tube portions, as shown inFIG. 2.

The heat exchanger tube inserting apparatus1shown inFIGS. 1 to 5includes roller conveyor sections2which each insert a hairpin tube T into insertion holes P of each of fins F and to a predetermined first position I (seeFIGS. 18 and 19), and a pushing cylinder3which inserts the hairpin tubes T which has been pushed to the predetermined first position I by the roller conveyor sections2further to a predetermined second position II (seeFIG. 20) located further inside than the first position I. Here, the predetermined first position refers to a position of a hairpin tube T at which a rear end of the hairpin portion HP of the hairpin tube T is away from the fins F by a predetermined distance. The first position is determined based on a location of driving rollers2aand driven rollers2bdescribed later.

Specifically, the heat exchanger tube inserting apparatus1includes the roller conveyor sections2, the pushing cylinder3, a main body frame4supporting the roller conveyor sections2and the pushing cylinder3, a first vertical mover5for moving the entirety of the main body frame4vertically, and a horizontal mover6for moving the main body frame4and the first vertical mover5horizontally.

Further, the heat exchanger tube inserting apparatus1includes first guide members7and a second guide member8for guiding hairpin tubes T, entanglement eliminators9for eliminating entanglement of a hairpin tube T, rotation detecting sensors10, a hairpin tube detecting sensor11, second vertical movers12for moving the driven rollers2band the first guide members7vertically, a third vertical mover13for moving the second guide member8vertically, a terminal (relay box18), a support board15, a hand switch16, and a foot switch17, these components being also supported on the main body frame4. Further, the heat exchanger tube inserting apparatus1includes a controller14such as a control panel, independently of the main body frame4. The controller14controls each driving component of the heat exchanger tube inserting apparatus1, i.e. driving of each of a motor21for driving the driving rollers2a, the pushing cylinder3, the first to third vertical movers5,12, and13and the horizontal mover6, via the terminal box18.

Further, as shown inFIG. 2, there is disposed a receiving table R for allowing the hairpin portions HP of hairpin tubes T to be placed thereon, at the upstream side of the heat exchanger tube inserting apparatus1in a conveyance direction Y of hairpin tubes T. A top portion of the receiving table is corrugated to have grooves and protrusions extending in parallel to one another in the conveyance direction Y. The hairpin portion HP of a hairpin tube T is placed on the receiving table R, whereby the hairpin tube T can be disposed to extend in the conveyance direction Y.

Further, there is disposed a working stand M for allowing an assembly of the number of fins F to be placed thereon, at the downstream side of the heat exchanger tube inserting apparatus1in the conveyance direction Y of hairpin tubes T. The number of fins are placed on the working stand M, in which state the heat exchanger tube inserting apparatus1inserts hairpin tubes T into fins.

The main body frame4includes a lower mounting board4a, an upper mounting board4bdisposed above the lower mounting board4a, and a connecting portion4c(seeFIGS. 4 and 5) connecting the lower mounting board4aand the upper mounting board4b.

The first vertical mover5includes a rod5aextending vertically, and a cylinder5bfor driving the rod5ato move vertically, as shown inFIG. 1. A top end of the rod5ais connected to a bottom surface of the lower mounting board4a. The first vertical mover5can vertically move the main body frame4and the above-mentioned structural elements supported thereon (such as the roller conveyor sections2and the pushing cylinder3), by the vertical movement of the rod5adriven by the cylinder5b. This makes it possible, in the case of assembling the heat exchanger E including tiers each having a row of hairpin tubes T, to vertically move the main body frame4by the first vertical mover5to thereby adjust its vertical position to correspond to each of the tiers. This makes it possible to insert hairpin tubes T at each of the tiers.

The horizontal mover6includes a main body portion6aand rails6b, as shown inFIGS. 1 to 3. The rails6bare two rails disposed on a perpendicular surface M1of the working stand M and extending in parallel with a top surface M2of the working stand M, the rails being vertically spaced from each other. The main body portion6amoves horizontally along the rails6band includes, for example, a roller which comes into contact with the rails6band a motor for driving the roller. The main body portion6ais connected with the cylinder5bof the first vertical mover5. The horizontal mover6can move the main body frame4and the first vertical mover5horizontally in the direction of X shown inFIG. 2(in a direction extending in parallel to the fins F) by the movement of the main body portion6aalong the rails6b.

The plurality of (in the first embodiment, three) roller conveyor sections2are disposed in parallel to one another in the conveyance direction Y of hairpin tubes T in order to convey a plurality of (in the first embodiment, three) hairpin tubes T simultaneously in the conveyance direction Y with the hairpin tubes T being disposed in parallel to one another, as shown inFIGS. 1 to 5.

Each of the roller conveyor sections2includes a pair of rollers oppositely disposed across a hairpin tube T, specifically, a driving roller2aand a driven roller2bdisposed above the driving roller2a.

The driving roller2aadvances a hairpin tube T. The driving rollers2aare driven by the common motor21as shown inFIG. 4. The driving rollers2aare coaxially secured to a rotary shaft21aof the motor21. The motor21is mounted to the lower mounting board4aof the main body frame4.

The driven roller2bcomes into contact with a hairpin tube T to rotate with the advancing movement of the hairpin tube T. The driven rollers2bare respectively disposed above the driving rollers2a. Each of the driven rollers2bis rotatably supported by a support portion12aof the second vertical mover12.

The driving roller2aof each of the roller conveyor sections2is driven for rotation by the motor21while vertically sandwiching a hairpin tube T with the corresponding driven roller2b. Thereby, roller the conveyor section2makes it possible to simultaneously insert a plurality of hairpin tubes T into insertion holes P of each of fins F and to the predetermined first position I.

The driving roller2aand the driven roller2bhave respective contact portions2a1and2b1(seeFIG. 1) that make contact with a hairpin tube T, the contact portion including a flat part on a circumferential portion thereof. The contact portions2a1and2b1are made of an elastic material (for example, a rubber such as urethane rubber or a resin) elastically deformable to allow a hairpin tube T to sink therein by a small amount of depression (for example, about 0.5 to 1 mm) when the respective flat parts come into contact with the hairpin tube T to thereby make surface contact with the hairpin tube T.

Because the driving roller2aand the driven roller2bhave the respective flat contact portions2a1and2b1as described, they can convey a hairpin tube T while making contact with the hairpin tube T according to the size (specifically, the tube diameter) of the hairpin tube T. Consequently, it is possible to advance hairpin tubes of various tube diameters. Furthermore, it is possible to advance a hairpin tube T having a form different from the form of a cylinder.

The pushing cylinder3is mounted to the lower mounting board4aof the main body frame4and at a side of the roller conveyor sections2(specifically, at the upstream side of the roller conveyor sections2in the horizontal movement direction X of the main body frame4by the horizontal mover6), as shown inFIG. 2. The roller conveyor sections2and the pushing cylinder3are disposed side by side. This allows simultaneous performance of the operation of moving hairpin tubes T to the first position I by the roller conveyor sections2and the operation of pushing hairpin tubes T located at the first position I to the second position II by the pushing cylinder3, which results in excellent working efficiency.

The pushing cylinder3includes two pushing portions vertically aligned as shown inFIGS. 6 to 8, specifically, a first pushing portion3aand a second pushing portion3bfor inserting hairpin tubes T into insertion holes P of each of fins F (seeFIG. 1). The pushing cylinder3is within the concept of a pushing section of the present invention.

The first pushing portion3aincludes a pushing plate3a1, a rod3a2having a leading end secured to the pushing plate3a1, and a cylinder3a3for driving the rod3a2horizontally in opposite directions. The pushing plate3a1receives a driving force of the cylinder3a3via the rod3a2to thereby push hairpin tubes T into insertion holes P of each of fins F by a predetermined first pushing amount while coming into contact with the respective hairpin portions HP (seeFIG. 2) of the hairpin tubes T. Specifically, as the first pushing amount, a stroke length S1(seeFIG. 7) over which the pushing plate3a1can be moved by the cylinder3a3of the first pushing portion3ais set at, for example, about 150 mm.

The pushing plate3a1has a width sufficient to simultaneously push a plurality of (in the first embodiment, three) hairpin tubes T as shown inFIG. 2.

The second pushing portion3bmoves the cylinder3a3of the first pushing portion3ain the direction toward fins F to thereby push hairpin tubes T which has been pushed by the first pushing portion by a predetermined second pushing amount. Similarly to the first pushing portion3a, the second pushing portion3bincludes a bracket3b1, a rod3b2having a leading end secured to the bracket3b1, and a cylinder3b3for driving the rod3bshorizontally in opposite directions. The cylinder3a3of the first pushing portion3ais secured to the bracket3b1. The bracket3b1receives a driving force of the cylinder3b3via the rod3b2to thereby allow the cylinder3a3of the first pushing portion3asecured to the bracket3b1to move over a predetermined stroke length (for example, about 90 mm). Therefore, as the second pushing amount, a stroke length S2(seeFIG. 8) over which the pushing plate3a1can be moved by simultaneous operation of the first pushing portion3aand the second pushing portion3bis set to be longer than the stroke length S1over which the pushing plate3a1is moved only by the first pushing portion3a. For example, the stroke length S2is set at about 240 mm.

In this manner, the pushing cylinder3is allowed to differentiate the stroke of the pushing plate3a1between the case of operating only the first pushing portion3aand the case of operating the first pushing portion3aand the second pushing portion3bsimultaneously. Therefore, in the assembling of the heat exchanger E including the two or more tiers each having a row of hairpin tubes T as shown inFIGS. 9 to 11, it is possible, even in the case where hairpin tubes T have different effective lengths from one tier to another, to push hairpin tubes T according to the effective length of the hairpin tubes T at each tier. Specifically, in the case of inserting hairpin tubes T into fins F constituting a first tier E1of the heat exchanger E, it is possible to operate only the first pushing portion3aof the pushing cylinder3to move the pushing plate3a1by the first pushing amount, i.e. over the stroke length S1, to thereby insert the hairpin tubes T into the fins F by the pushing plate3a1. Further, in the case of inserting hairpin tubes T into fins F constituting a second tier E2of the heat exchanger E, it is possible to raise the pushing cylinder3by the first vertical mover5for vertically moving the entirety of the main body frame4, and then operate both of the first pushing portion3aand the second pushing portion3bof the pushing cylinder3to move the pushing plate3a1by the second pushing amount, i.e. over the stroke length S2longer than the first stroke length S1, to thereby insert the hairpin tubes T into the fins F by the pushing plate3aalso at the second tier E2of the heat exchanger E.

The first guide members7are respectively disposed upstream of the plurality of driven rollers2bin the conveyance direction Y of hairpin tubes T, as shown inFIGS. 1 to 3andFIG. 12. Each of the first guide members7is supported by a guide support portion12b(seeFIG. 1) of the second vertical mover12from above. The first guide member7positions a hairpin tube T with respect to the driving roller2aand the driven roller2b.

The first guide member7includes two grooves7aopening at a lower end thereof as shown inFIG. 12. Each of the grooves7aextends in the conveyance direction Y of hairpin tubes T. A rib7blies between the two grooves7ato divide one groove from the other. In other words, the first guide member7has an E-shaped cross section. A width W of each of the grooves7ais set to be equal to or slightly greater than an outer diameter of each of the two straight tube portions SP. This makes it possible to reliably guide a hairpin tube T into a space between the driving roller2aand the driven roller2b.

Further, when hairpin tubes T are advanced to the first position I (seeFIGS. 2 and 18) by the roller conveyor sections2, the hairpin portions HP stop in front of the first guide members7, and thereafter the first guide members7and the driven rollers2bare raised by the vertical mover12. Therefore, the ribs7band the hairpin portions HP do not make contact with each other.

The first guide members7are made of a hard resin having a smooth surface, such as MC nylon.

A hairpin tube T is positioned horizontally by the first guide member7immediately in front of the driving roller2aand the driven roller2b. Therefore, the hairpin tube T can be reliably guided into the gap between the driving roller2aand the driven roller2bwithout buckling between the first guide member7and the second guide member8.

The support board15allows hairpin tubes T to be placed thereon. The support board15is disposed upstream of the driving rollers2ain the conveyance direction Y of hairpin tubes T as shown inFIG. 1. The support board15is secured to the lower mounting board4aof the main body frame4. In the first embodiment, a downstream end15a(seeFIG. 1) of the support board15is located upstream of the first guide members7. However, the downstream end15amay be located downstream of the first guide members7.

The second guide member8positions respective hairpin tubes T with respect to the first guide members7as shown inFIGS. 1 to 3, 13, and 14A and 14B. The second guide member8is disposed upstream of the first guide members7in the conveyance direction of hairpin tubes T. Further, the second guide member8is disposed above the support board15where hairpin tubes T are placed so as to be opposite to the support board15. The second guide member8is hanged by a guide support portion13a(seeFIG. 1) of the third vertical mover13.

The second guide member8is generally in the form of a flat plate, and includes three grooves8aopening at a lower end thereof. A width W2of each of the grooves8ais set to be equal to or slightly greater than an outer width of the hairpin tube T (i.e. the distance between respective outer surfaces of the two straight tube portions SP). This allows hairpin tubes T to be easily guided to the first guide members7. A bottom edge of the groove8ais curved as shown inFIG. 13. This allows hairpin tubes T placed on the support board15to be easily inserted into the grooves8awhen the guide member8is lowered.

Further, recesses8care formed by cutting out a top plate portion8bof the second guide member8in upstream portions of the second guide member8respectively corresponding to the grooves8a, as shown inFIGS. 14A and 14B. A part of each of the entanglement eliminators9is inserted in a corresponding one of the recesses8c.

The second guide member8is an integrally molded article, and has a structure capable of simultaneously positioning a plurality of hairpin tubes T. The second guide member8is, similarly to the guide members7, made of a hard resin having a smooth surface, such as MC nylon. The integral formation of the second guide member8results in the need for only one third vertical mover13for vertically moving the second guide member8. This allows a simple configuration of the heat exchanger tube inserting apparatus.

The entanglement eliminators9are disposed upstream of the driving rollers2aand the driven rollers2bin the conveyance direction Y of hairpin tubes T, as shown inFIGS. 1 to 3, 13 and 14A and 14B. Specifically, the entanglement eliminators9are respectively partially inserted into the recesses8cformed in the upstream portions of the second guide member8that correspond to the grooves8a. The entanglement eliminators9protrude upstream beyond the second guide member8.

The entanglement eliminator9is configured to eliminate entanglement between the straight tube portions SP of a hairpin tube T to be guided by the driving roller2aand the driven roller2b. Specifically, the entanglement eliminator is in the form of a plate. The entanglement eliminator9is inserted in the recess8cof the second guide member8vertically movably in a standing state. A width W3of the entanglement eliminator9is set to be equal to or slightly smaller than an inner width of the hairpin tube T (i.e. the distance between respective inner surfaces of the two straight tube portions SP). This allows the entanglement eliminator9to move relative to and between the two straight tube portions SP as a hairpin tube T moves in the conveyance direction Y, to thereby correct the two straight tube portions SP so as to extend in the conveyance direction Y. In this manner, entanglement between the straight tube portions SP can be eliminated.

Further, in the first embodiment, the entanglement eliminators9protrude upstream beyond the second guide member8. Therefore, it is possible to eliminate entanglement between the two straight tube portions SP of a hairpin tube T at the upstream side of the second guide member8, i.e. before the hairpin tube T reaches the second guide member8.

Further, the entanglement eliminator9includes an oblique portion9asloping in a direction away from a movement region of hairpin tubes T as proceeding upstream in the conveyance direction Y of hairpin tubes T. The angle of the oblique portion9ais set at an angle allowing the hairpin portion HP of a hairpin tube T, when it moves to the oblique portion9a, to come into contact with and slide along a surface of the oblique portion9a, as shown inFIG. 14A. The entanglement eliminator9is inserted in the recess8cof the second guide member8vertically movably. This allows the entanglement eliminator9to recede from the hairpin portion HP when the hairpin portion HP comes into contact with the oblique portion9a.

The oblique portion9ahas a curved edge. Therefore, the hairpin portion HP is less likely to be interrupted by the edge of the oblique portion9a.

Further, the entanglement eliminators9are supported by an entanglement eliminator support portion13bof the third vertical mover13from above, as shown inFIG. 1. Further, the entanglement eliminator9is pushed downward by a spring22inserted between the entanglement eliminator9and a top plate13b1of the entanglement eliminator support portion13b, and is vertically movable.

The rotation detection sensors10respectively detect rotation of the driven rollers2b. The rotation detection sensors10are respectively provided for each driven roller2bof the roller conveyor section2, as shown inFIGS. 4 and 5. Each of the rotation detection sensors10is attached to a movable plate12c(seeFIG. 1) of the second vertical mover12via a bracket or the like.

The rotation detection sensors10may be of any type as long as they can detect rotation of the driven rollers2b. For example, a proximity sensor may be used as the rotation detection sensor10. In that case, a detection object made of a metal such as iron is embedded in a circumferential portion of the driven roller2bto be detected by the proximity sensor. This allows the detection object to be detected by the proximity sensor each time it passes in front of the proximity sensor in rotation of the driven roller2b. Therefore, it is possible for the proximity sensor to detect the rotation of the driven roller2b.

In the case where the rotation detection sensor10detects that the corresponding driven roller2bis not rotating, the controller14controls the motor21to stop driving of the driving roller2ain order to stop conveyance of a hairpin tube T by the roller conveyor section2. In other words, the driven roller2bis not rotating when no hairpin tube T is being advanced. Therefore, when the driven roller2bis detected as not rotating, the conveying operation of a hairpin tube T by the roller conveyor section2is stopped. At the same time, the controller14controls the relevant second vertical mover12so as to recede the driven roller2bupward, and further controls the horizontal mover6so as to move the main body frame4in the direction opposite to the horizontal movement direction X in order to return the main body frame4to a position prior to the insertion operation.

The hairpin tube detection sensors11are respectively disposed upstream of the plurality of first guide members7in the conveyance direction Y of hairpin tubes T, as shown inFIGS. 1 to 3. Each of the hairpin tube detection sensors11detects whether a hairpin tube T is at a position between a predetermined initial position N and a position immediately before the first position I. The predetermined initial position N in the first embodiment refers to, for example, a position of a hairpin tube T at which the hairpin tube T is inserted in insertion holes P of a front fin F (on the upstream side in the conveyance direction Y) of the number of fins, as shown inFIG. 16. The initial position N may be a position at which a hairpin tube T is inserted into insertion holes P of a small number of front fins of the number of fins F and can be maintained in that state.

The hairpin tube detection sensor11specifically includes a contact roller11aand a proximity sensor11bas shown inFIG. 1. The contact roller11ais rotatably supported on a bracket11c. Further, the hairpin tube detection sensor11is supported vertically movably with respect to a movable plate13cof the third vertical mover13via the bracket11c. The proximity sensor11bis disposed at a leading end of the bracket11c. A detection object11dto be detected by the proximity sensor11bis disposed on the movable plate13c. The proximity sensor11band the detection object11dmay be inversely disposed.

When a hairpin tube T is at the predetermined initial position N, the contact roller11aof the hairpin tube detection sensor11is on the hairpin tube T, as shown inFIG. 16. Therefore, the bracket11cand the proximity sensor11bdisposed at the leading end of the bracket11care in a raised state in which the proximity sensor11bis distant from the detection object11d. This allows the proximity sensor11bto detect that the detection object11dis distant therefrom. Based on this, it is possible to detect that the hairpin tube T is at the predetermined initial position N. On the other hand, when a hairpin tube T is not at the predetermined initial position N, the contact roller11a, the bracket11cand the proximity sensor11bare located at a lower position than the position shown inFIG. 16, as shown inFIG. 18. At this time, the proximity sensor11bcan detect that no hairpin tube T is at the predetermined initial position N by detecting that the detection object11dis in proximity thereto. When the hairpin tube detection sensor11detects that no hairpin tube T is at the predetermined initial position N, the controller14controls the second vertical mover12that corresponds to the hairpin tube detection sensor11having detected no hairpin tube T, so as not to lower the driven roller2band the first guide member7as described later.

Further, the above-described hairpin tube detection sensor11detects whether a hairpin tube T is at a position between the predetermined initial position N and the position immediately before the first position I while the hairpin tube T is being conveyed by the driving roller2aand the driven roller2bof the roller conveyor section2, as shown inFIGS. 17 to 18. Specifically, as shown inFIG. 17, while a hairpin tube T moves from the initial position N to the position immediately before the predetermined first position I, the contact roller11ais on the hairpin tube T and the proximity sensor11bis distant from the detection object11d. This allows the proximity sensor11bto detect that the hairpin portion HP of the hairpin tube T has not passed the contact roller11a. On the other hand, as shown inFIG. 18, when a hairpin tube T has moved to the predetermined first position I, the contact roller11adescends, so that the proximity sensor11bapproaches the detection object11d. This allows the proximity sensor11bto detect that the hairpin portion HP of the hairpin tube T has passed the contact roller11a. When the hairpin tube detection sensor11detects the passage of the hairpin portion HP, the controller14causes the motor21to stop in order to stop rotation of the driving roller2aof the roller conveyor section2(see step S9inFIG. 15).

The contact roller11ahas a width sufficient to be placed on the two straight tube portions SP of a hairpin tube T at once.

The contact roller11ais made to rotate upon coming into contact with a hairpin tube T to have a reduced friction with the hairpin tube T, thereby reducing rubbing of the hairpin tube T. Further, the contact roller11ais pressed downward by an unillustrated spring via the bracket11c. This makes it possible to press the hairpin tube T from above to thereby prevent the hairpin tube T from shaking during the movement.

It may be appreciated to use a resin plate slidable upon coming into contact with a hairpin tube T, in place of the contact roller11a.

The second vertical movers12are respectively disposed at positions corresponding to the roller conveyor sections2as shown inFIGS. 1 to 4. For each of the roller conveyor sections2, the second vertical mover12is provided to vertically move the driven roller2band the first guide member7. This makes it possible to vertically move the first guide member7and the driven roller2bfor each hairpin tube T. Consequently, the driven roller2band the first guide member7can be shifted between a position at which they come in contact with a hairpin tube T and a position to which they recede upward from the hairpin tube T. Therefore, while a plurality of hairpin tubes T are advanced to the plurality of roller conveyor sections2simultaneously, and when there is an abnormal movement of one of the hairpin tubes T, it is possible to move the driven roller2band the first guide member7corresponding to that hairpin tube T in a direction of receding upward from that hairpin tube T.

Each of the second vertical movers12specifically includes, as shown inFIG. 1, the roller support portion12arotatably supporting the driven roller2b, the guide support portion12bsupporting the first guide member7, the movable plate12cconnected with the roller support portion12aand the guide support portion12b, a rod12dconnected to the movable plate12c, and a cylinder12efor driving the rod12dvertically. The cylinder12eis secured to the upper mounting board4bof the main body frame4.

The third vertical mover13is disposed upstream of the second vertical movers12in the conveyance direction Y of hairpin tubes T. The third vertical mover13can vertically move the second guide member8and the entanglement eliminators9. Specifically, the third vertical mover13includes, as shown inFIG. 1, the guide support portion13asupporting the second guide member8, the entanglement eliminator support portion13bsupporting the entanglement eliminators9vertically movably, the movable plate13cconnected with the guide support portion13aand the entanglement eliminator support portion13b, a rod13dconnected to the movable plate13c, and a cylinder13efor driving the rod13dvertically. The cylinder13eis secured to the upper mounting board4bof the main body frame4.

The hand switch16can be operated manually such as by being pushed with a hand. The hand switch16issues a command to the controller14to initially start a series of steps of insertion operation performed by the heat exchanger tube inserting apparatus1. In this manner, the operation is initially started by manually operating the hand switch16, which improves the safety. The hand switch16is disposed at a position allowing an operator to easily operate the hand switch16during his work, for example, on a top surface of the upper mounting board4bof the main body frame4. Further, an emergency stop button23is disposed at a position adjacent to the hand switch16for stopping the heat exchanger tube inserting apparatus1in the case of an emergency.

The foot switch17can be operated with a foot such as by being pushed with a foot. The foot switch17issues a command to the controller14to start a subsequent step when the heat exchanger tube inserting apparatus1is in a suspended state in the middle of insertion operation of the heat exchanger tube inserting apparatus1(specifically, when insertion of hairpin tubes T by the roller conveyor sections2is normally completed at step S12inFIG. 15). The foot switch17is disposed at a position allowing an operator to easily operate the foot switch17during his work, for example, at a position below the lower mounting board4aof the main body frame4allowing an easy operation with his foot.

Now, an inserting method of hairpin tubes T using the heat exchanger tube inserting apparatus1according to the first embodiment will be described with reference to a flowchart ofFIG. 15, andFIGS. 16 to 20.

First, as shown inFIG. 16(andFIGS. 1 and 2), an operator sets a plurality of (inFIG. 2, three) hairpin tubes T at the predetermined initial position N (for example, at a position at which respective leading ends of the hairpin tubes T are inserted in insertion holes P of a front fin F of the number of fins F mounted on the working stand M) in advance. At this time, because the hairpin portions HP of the hairpin tubes T are placed on the receiving table R which is in the form of a corrugated plate, the hairpin tubes T are disposed substantially in parallel to each other, as shown inFIG. 2.

After setting the hairpin tubes T at the initial position N, the operator manually operates the hand switch16disposed at the upper end of the main body frame4as shown in step S1of the flowchart inFIG. 15, to thereby start a series of steps of operation performed by the heat exchanger tube inserting apparatus1. It should be noted that, before the start of operation, the driven rollers2b, the first guide members7, the second guide member8, the entanglement eliminators9, and the hairpin tube detection sensors11are at positions apart upward from the hairpin tubes T, as shown inFIG. 1.

First, as shown in step S2ofFIG. 15, the controller14controls the horizontal mover6so as to move the main body frame4in the horizontal movement direction X in order to bring the main body frame4close to the plurality of hairpin tubes T set at the initial position N. Completion of the horizontal movement of the main body frame4allows each of the hairpin tubes T to be on the driving roller2aand the support board15.

Subsequently, the controller14controls the third vertical mover13so as to lower the second guide member8as shown in step S3ofFIG. 15. At this time, the entanglement eliminators9and the hairpin tube detection sensors11also descend with the second guide member8. This allows the hairpin tubes T to be respectively inserted into the grooves8aof the second guide member8. At the same time, each of the entanglement eliminators9is inserted into the space between the two straight tube portions SP of the hairpin tube T.

Subsequently, each of the hairpin tube detection sensors11detects whether the corresponding hairpin tube T is at the initial position N as shown in step S4. Specifically, the contact roller11aof the detection sensor11gets on the hairpin tube T, which allows the proximity sensor11bto detect that the detection object11dis distant therefrom. Based on this, the hairpin tube T is detected as being at the initial position N.

In the case where the hairpin tube T is at the initial position N, the controller14controls the relevant second vertical mover12so as to lower the driven roller2band the first guide member7, as show in step S5ofFIG. 15. At the same time, the controller14controls the motor21so as to rotate the relevant driving roller2aof the roller conveyor section2, as shown in step S6ofFIG. 15. Consequently, each of the hairpin tubes T is sandwiched between the driving roller2aand the driven roller2bof the roller conveyor section2, as shown inFIG. 16. At this time, the straight portions SP of the hairpin tube T are inserted into the grooves7aof the first guide member7. Each of the hairpin tubes T is advanced in the conveyance direction Y while being sandwiched between the driving roller2aand the driven roller2bof the roller conveyor section2, to be inserted into insertion holes P of each fin F, as shown inFIGS. 16 and 17.

In the movement of the hairpin tube T, the two straight tube portions SP of the hairpin tube T are first guided to extend in the conveyance direction Y with a sufficient degree of accuracy while being inserted in the grooves8aof the second guide member8together, and are then advanced to the first guide member7. Further, the two straight tube portions SP of the hairpin tube T are guided to extend in the conveyance direction Y with a higher accuracy while respectively being inserted in the grooves7aof the first guide member7. Subsequently, the straight tube portions SP are advanced into the space between the driving roller2aand the driven roller2b.

While the hairpin tube T is advancing in the manner as described, the entanglement eliminator9advances relative to the two straight tube portions SP of the hairpin tube T so as to get into the space between the straight tube portions SP (seeFIG. 14B). This allows the entanglement eliminator9to eliminate entanglement between the straight tube portions SP. When the hairpin portion HP of the hairpin tube T reaches the entanglement eliminator9, the entanglement eliminator9recedes upward with the oblique portion9athereof making contact with the hairpin portion HP (seeFIG. 17). The entanglement eliminator9returns to the lower position by a restoring force of the spring22when the hairpin portion HP passes the entanglement eliminator9(seeFIG. 18).

Further, while the hairpin tube T is moving, the rotation detection sensor10detects whether the corresponding driven roller2bis rotating with the advancing movement of the hairpin tube T, as shown in step S7ofFIG. 15.

In addition, at this time, the hairpin tube detection sensor11detects whether the hairpin portion HP of the corresponding hairpin tube T has passed thereby, as shown in step S8. Specifically, when the hairpin portion HP passes the contact roller11aof the sensor11, the contact roller11adescends as shown inFIG. 18. This allows the proximity sensor11bto detect that the detection object11dis in proximity thereto. Based on this, the detection as to whether the hairpin portion HP has passed is performed. When the hairpin portion HP passes, the hairpin tube T has been advanced to the predetermined first position I by the roller conveyor section2, as shown inFIGS. 2 and 18. In this state, the hairpin portion HP of the hairpin tube T is located at the upstream of the first guide member7in the conveyance direction Y.

In the case where the passage of the hairpin portion HP is detected, the controller14controls the relevant second vertical mover12so as to raise the driven roller2band the first guide member7, as shown in step S9ofFIG. 15. In the case where the passage of the hairpin portion HP is not detected, the operation returns to step S6to keep the relevant driving roller2arotating.

Subsequently, the controller14controls the motor21so as to stop rotation of the relevant driving miler2a, as shown in step S10.

Thereafter, as shown in step S11ofFIG. 15, the controller14controls the third vertical mover13so as to raise the second guide member8(with the entanglement eliminators9and the hairpin tube detection sensors11) (seeFIG. 19), whereby the series of steps (steps S2to S12) of inserting the hairpin tubes T to the first position I by the roller conveyor sections2is successfully completed (step S12).

During the above-described series of steps (steps S2to S12) of operation, the operator sets, in advance, hairpin tubes T to be subjected to the second insertion operation at the predetermined initial position N at the downstream side of the hairpin tubes T that have been subjected to the first insertion operation and inserted to the first position I as described above, in the horizontal movement direction X, as shown inFIG. 2.

After setting the second set of hairpin tubes T at the initial position N, the operator operates the foot switch17with his foot, the foot switch being located below the main body frame4, as shown in step S19of the flowchart inFIG. 15. This allows the heat exchanger tube inserting apparatus1to simultaneously start a series of steps of inserting the second set of hairpin tubes T to the first position I by the roller conveyor sections2, and an operation of pushing the first set of hairpin tubes T to the second position II by the pushing cylinder3.

Specifically, the controller14first controls the horizontal mover6so as to move the main body frame4in the horizontal movement direction X as shown in step S2ofFIG. 15in the same manner as described. At this time, when the horizontal movement of the main body frame4is completed, the main body frame4has moved in the horizontal movement direction X by the width of three hairpin tubes T from the position shown inFIG. 2. As a result, the second set of hairpin tubes T (i.e. the hairpin tubes T set at the initial position N) are placed on the driving rollers2aand the support board15, and at the same time, the first set of the hairpin tubes T which has been inserted to the first position I are placed in front of the pushing cylinder3.

This allows the operation of inserting the second set of hairpin tubes T to the first position I by the roller conveyor sections2to proceed through the above-described steps S3to S12, and at the same time, the pushing cylinder3to be extended to push the first set of hairpin tubes T to the second position II as shown in step S17. Specifically, as shown inFIG. 20, the cylinder3a3of the pushing cylinder3is caused to drive the rod3a2forward to thereby advance the pushing plate3a1located at the leading end of the rod3a2. This allows the pushing plate3a1to push the hairpin tubes T to the second position II while making contact with the hairpin portions HP. After the hairpin tubes T are pushed to the predetermined second position II, the pushing cylinder3(specifically, the pushing plate3a1) is contracted and returns to the state capable of pushing the second set of hairpin tubes T to the second position II, as shown in step S18.

In the manner as described, it is possible to simultaneously perform the operation of advancing hairpin tubes T to the first position I by the roller conveyor sections2and the operation of pushing hairpin tubes T which has been advanced to the first position I to the second position II by the pushing cylinder3. Repetition of these operations allows hairpin tubes T to pass through all the insertion holes P of the fins F constituting a tier.

When the insertion operation at a tier of the heat exchanger E is completed, the first vertical mover5is driven to raise the main body frame4, to thereby allow insertion of hairpin tubes T into the insertion holes P of fins F constituting an upper tier.

In the case where the hairpin tube detection sensor11does not detect that the corresponding hairpin tube T is at the initial position N at the above-described step S4shown inFIG. 15, the controller14controls the second vertical mover12that corresponds to the hairpin tube detection sensor11having not detected the hairpin tube T, so as not to perform the operation (step S5) of lowering the driven roller2band the first guide member7(i.e. the operation jumps to step11). Further, the controller14controls another second vertical mover12that corresponds to the hairpin tube detection sensor11having detected the hairpin tube T, so as to lower the driven roller2band the first guide member7. In this manner, the operation is controlled through the series of steps from S5to S10in order to insert only the detected hairpin tube T to the first position I, and then proceeds to step S11.

Further, in the case where the driven roller2bis not detected as rotating at the above-described step S7, the corresponding hairpin tube T is not being advanced normally because, for example, the hairpin tube T is caught on the edge of insertion holes P of fins F. In such case, an unillustrated alarm device emits an alarm sound to notify the operator of the insertion failure of the hairpin tube T. At the same time, the controller14proceeds to step S13and controls the second vertical mover12that corresponds to the hairpin tube T not being advanced normally, so as to raise the driven roller2band the first guide member7. Subsequently, the controller14controls the motor21so as to stop rotation of the relevant driving roller2a(step S14), and then controls the third vertical mover13so as to raise the second guide member8(step S15). Further, the controller14controls the horizontal mover6so as to move the main body frame4horizontally to the position prior to the operation, to thereby end the operation while leaving the hairpin tube T failed to be successfully inserted to the first position I by the roller conveyor section2(step S16). In this case, the operator removes the hairpin tube T having not been advanced normally, and sets a replacement new hairpin tube T at the initial position N properly. Thereafter, the operator pushes the hand switch16with a hand (step S1) to thereby restart the insertion operation of the heat exchanger tube inserting apparatus1from step S2.

As described above, the heat exchanger tube inserting apparatus1according to the first embodiment includes the roller conveyor sections2and the pushing cylinder3as a mechanism for advancing hairpin tubes T into insertion holes P of fins F in two steps. Therefore, as long as hairpin tubes T are set at the predetermined initial position N at which the hairpin tubes T are inserted in insertion holes P of a front fin F of the number of fins F in advance, it is possible to first insert the hairpin tubes T into insertion holes P of fins F to the predetermined position I by rotating the driving rollers2aand the driven rollers2bof the roller conveyor sections2, and then further insert the hairpin tubes T to the predetermined second position II by the pushing cylinder3, thereby inserting the hairpin tubes T to the final position, i.e. the predetermined second position II. Therefore, different from the conventional heat exchanger tube inserting apparatus, it does not require a heat exchanger tube inserting means having such a long stroke length as to fully insert a hairpin tube into insertion holes of a number of fins, nor guide rods being so long as to pass through the number of fins F for supporting the hairpin tube T. Consequently, the heat exchanger tube inserting apparatus1can be made small in size.

Further, the above-described heat exchanger tube inserting apparatus1requires an operator to set hairpin tubes T at the initial position N in advance. However, because of being a semi-automatic machine, the heat exchanger tube inserting apparatus1can be configured extremely simply with the combination of the roller conveyor sections2and the pushing cylinder3. Therefore, it is only necessary for an operator to insert leading ends of hairpin tubes T into insertion holes P of a small number of fins F to thereby set the hairpin tubes T at the initial position N, and thereafter, the above-described heat exchanger tube inserting apparatus1automatically and reliably inserts the hairpin tubes T to the final second position II. Therefore, the heat exchanger tube inserting apparatus1can perform the insertion operation efficiently with the simple structure. Further, the operation of setting hairpin tubes T at the initial position N by an operator and the subsequent operation of inserting the hairpin tubes T by the heat exchanger tube inserting apparatus1are performed individually and in parallel as described, which improves the operation rate of the apparatus.

Further, use of the above-described heat exchanger tube inserting apparatus1to insert hairpin tubes T reduces the number and time of handlings of hairpin tubes T, i.e. operator action of pulling in a hairpin tube T and inserting it into fins F with his hands. Therefore, it is possible to reduce deformation of hairpin tubes T during the insertion operation and the number of hairpin tubes T to be thrown away.

Further, use of the heat exchanger tube inserting apparatus1according to the first embodiment makes it possible to insert hairpin tubes T at a constant speed, and therefore reduce fluctuations in the insertion time of an operator. Thus, the operation time shortens.

Further, use of the heat exchanger tube inserting apparatus1according to the first embodiment allows the heat exchanger tube inserting apparatus1to perform most of the insertion operation of hairpin tubes T, which reduces the burden on an operator.

Further, in the heat exchanger tube inserting apparatus1according to the first embodiment, hairpin tubes T are advanced to the first position I to complete the insertion of their large portions by driving of the rollers of the roller conveyor sections2, and then pushed to the final second position II by the pushing cylinder3. This enables projecting lengths (projecting extent) of the hairpin tubes T beyond the front fin F to be equalized to one another.

Furthermore, the above-described heat exchanger tube inserting apparatus1is capable of advancing a hairpin tube T having a desired length, by advancing the hairpin tube T by rotation of the driving roller2aand the driven roller2bof the roller conveyor section2. Therefore, provision of a stroke length can be eliminated, and hairpin tubes T of various lengths can be inserted. Therefore, it is possible to insert even an extremely long hairpin tube T into insertion holes P of fins F. Consequently, the length of usable hairpin tubes T is not limited. Furthermore, the apparatus can be adapted to hairpin tubes T having a different tube diameter by changing to use first guide members7and second guide member8having a dimension corresponding to the tube diameter.

Furthermore, the heat exchanger tube inserting apparatus1according to the first embodiment 1 has an extremely simple and compact configuration with the combination of the roller conveyor sections2and the pushing cylinder3. Therefore, it requires only a small installation space. Therefore, the heat exchanger tube inserting apparatus1according to the first embodiment can be mounted to the existing working stand M on which the number of fins F are placed, and furthermore, it can be easily adjusted according to the change of layout in a factory.

Further, the heat exchanger tube inserting apparatus1according to the first embodiment 1 has an extremely simple and compact configuration with the combination of the roller conveyor sections2and the pushing cylinder3, which allows an operator to visually check whether hairpin tubes T have been inserted to the final second position II, unlike the fully-automatic inserting apparatus such as one disclosed in Patent Literature 1

Further, in the heat exchanger tube inserting apparatus1according to the first embodiment, the entanglement eliminator9disposed upstream of the driving roller2aand the driven roller2bin the conveyance direction Y of hairpin tubes T eliminates entanglement between the straight tube positions SP of a hairpin tube T before the hairpin tube T is advanced into insertion holes P of fins by rotation of the driving roller2aand the driven roller2b. This makes the hairpin tube T more likely to be successfully inserted without being interrupted by the second guide member8or the driving roller2aand the driven roller2blocated downstream thereof.

Further, in the heat exchanger tube inserting apparatus1according to the first embodiment, in the course of advancement of a hairpin tube T into insertion holes P of fins F by rotation of the driving roller2aand the driven roller2b, the oblique portion9aof the entanglement eliminator9can come into contact with the hairpin portion HP to thereby allow the entanglement eliminator9to recede upward from the hairpin portion HP when the hairpin portion HP passes the entanglement eliminator9. This makes the hairpin portion HP less likely to be interrupted by the entanglement eliminator9.

Furthermore, in the heat exchanger tube inserting apparatus1according to the first embodiment, the entanglement eliminator9recedes upward from a hairpin portion HP by the oblique portion9acoming into contact with the hairpin portion HP, and the entanglement eliminator9is pushed downward by a resilient force of the spring22. Therefore, it is possible to eliminate entanglement occurring in the process of inserting a hairpin tube T to prevent the hairpin tube T from getting abnormally caught in the apparatus (in particular, in the second guide member8) with a simple configuration without an additional driver component (such as cylinder or sensor) for moving the entanglement eliminator9.

Further, in the heat exchanger tube inserting apparatus1according to the first embodiment, the respective contact portions2a1and2b1of the driving roller2aand the driven roller2bthat come into contact with a hairpin tube T each have a flat part elastically deformable to make surface contact with the hairpin tube T when coming into contact with the hairpin tube T. This makes it possible to reliably advance a hairpin tube T into insertion holes of fins F by rotation of the driving roller2aand the driven roller2baccording to an outer diameter of the hairpin tube T. Furthermore, the use of the above-described rollers2aand2bmakes it possible to advance a tube having a different cross-section from the circular cross-section. Furthermore, the elastic deformation of the driving roller2aand the driven roller2bmakes a hairpin tube T less likely to be deformed or damaged.

Furthermore, a marketed rubber-coated flat roller can be used rather than a grooved roller as the driving roller2aand the driven roller2b, which allows simplification of the apparatus.

Further, in the heat exchanger tube inserting apparatus1according to the first embodiment, the pushing cylinder3can push hairpin tubes T over two different distances by use of the first pushing portion3aand the second pushing portion3b. Specifically, it is possible to push hairpin tubes T over the predetermined stroke length S1by use of only the first pushing portion3a. Further, it is possible to push hairpin tubes T over the stroke length S2longer than the above-mentioned stroke length S1by combinational simultaneous operation of the first pushing portion3aand the second pushing portion3b. Therefore, even in the case where one tier includes a row of hairpin tubes T having a different effective length from another tier in assembling of a heat exchanger E including the tiers, it is possible to insert one tier of hairpin tubes T in a different stroke length from another tier to thereby accord with the effective length.

Such configuration of the pushing cylinder3including the plurality of pushing portions3aand3bis adaptable to a heat exchanger E including any number of tiers by providing a necessary number of pushing portions.

Further, in the heat exchanger tube inserting apparatus1according to the first embodiment, the first guide member7positions a hairpin tube T with respect to the driving roller2aand the driven roller2bat the upstream side of the driving roller2aand the driven roller2bin the conveyance direction Y of hairpin tubes T. This makes the hairpin tube T less likely to reach the driving roller2aand the driven roller2bobliquely to the predetermined conveyance direction Y.

Further, in the heat exchanger tube inserting apparatus1according to the first embodiment including the plurality of roller conveyor sections2, the first guide members7are respectively disposed upstream of the roller conveyor sections2in the conveyance direction Y of hairpin tubes T. This allows each of the first guide members7to accurately position a hairpin tube T which is to be advanced by the corresponding roller conveyor section2, with respect to the driving roller2aand the driven roller2b. This makes, in insertion of a plurality of hairpin tubes T by the plurality of roller conveyor sections2, each of the hairpin tube T less likely to reach the corresponding driving roller2aand the driven roller2bobliquely to the predetermined conveyance direction Y. Further, it is also possible, in insertion of a plurality of hairpin tubes T by the plurality of roller conveyor sections2, to prevent each of the hairpin tube detection sensors11(i.e. heat exchanger tube detection sensors11) from making an erroneous detection.

Further, in the heat exchanger tube inserting apparatus1according to the first embodiment, it is possible to position hairpin tubes T with respect to the first guide members7by the second guide member8at the upstream side of the first guide members7in the conveyance direction Y of hairpin tubes T before the hairpin tubes are advanced to the respective corresponding first guide members7. This makes each of the hairpin tubes T even less likely to reach the driving roller2aand the driven roller2bobliquely to the predetermined conveyance direction Y.

Further, in the heat exchanger tube inserting apparatus1according to the first embodiment, it is possible to detect that a hairpin tube T is not at the predetermined initial position N by the hairpin tube detection sensor11. This makes it possible to promptly inform that the hairpin tube T is not normally set at the initial position N.

Further, in the heat exchanger tube inserting apparatus1according to the first embodiment, the hairpin tube detection sensor11detects, while a hairpin tube T is being conveyed by the driving roller2aand the driven roller2bof the roller conveyor section2, whether the hairpin tube T is at a position between the initial position N and the position immediately before the first position I. This allows detection of passage of the hairpin portion HP of the hairpin tube T beyond the contact roller11aof the hairpin tube detection sensor11to thereby detect that the hairpin tube T has moved to the first position I. Therefore, when the hairpin tube detection sensor11detects passage of a hairpin portion HP, the controller14can control the driving roller2aof the relevant roller conveyor section2to stop rotating to thereby stop movement of the hairpin tube T.

Further, in the heat exchanger tube inserting apparatus1according to the first embodiment, the pair of driving roller2aand the driven roller2bare oppositely disposed across a hairpin tube T in each of the roller conveyor sections2. This allows the driving roller2aand the driven roller2bto reliably advance the hairpin tube T into insertion holes P of fins F while vertically sandwiching the hairpin tube T therebetween.

Further, in the heat exchanger tube inserting apparatus1according to the first embodiment, each of the roller conveyor sections2include the pair of driving roller2aand the driven roller2b. Therefore, the provision of one driving roller2aallows simplification of the mechanism. Furthermore, the driven roller2bwhich is simpler in the mechanism can be moved easily between the position at which the driven roller2bcomes into contact with a hairpin tube T and the position to which the driven roller2brecedes from the hairpin tube T.

Further, in the heat exchanger tube inserting apparatus1according to the first embodiment, in the case where a hairpin tube T is not normally advanced, the corresponding driven roller2bis in the state of not rotating normally. Therefore, it is possible for the rotation detection sensor10to detect an abnormal state in which a hairpin tube T is not normally advanced by detecting rotation of the driven roller2b.

Further, in the heat exchanger tube inserting apparatus1according to the first embodiment, in simultaneous insertion of a plurality of hairpin tubes T by the plurality of roller conveyor sections2, it is possible, even in the case where an abnormality occurs in the insertion of one of the hairpin tubes T, to detect the abnormality. It is possible to detect an abnormality for each of the roller conveyor sections2by the rotation detection sensor10provided for each of the driven rollers2bof the roller conveyor sections2. Therefore, the driven roller2band the first guide member7of the roller conveyor section2for which an insertion failure of a hairpin tube T has been detected can be raised by the corresponding second vertical mover12. This allows an operator to easily remove the hairpin tube T having failed to be inserted, and replace it with a new hairpin tube T.

Further, in the heat exchanger tube inserting apparatus1according to the first embodiment, in the case where the rotation detection sensor10detects an abnormality in rotation of the driven roller2b, the conveying operation of a hairpin tube T by the relevant roller conveyor section2is stopped. Therefore, it is possible to detect an insertion failure of a hairpin tube T for each of the roller conveyor sections2, and stop only the roller conveyor section2which has been detected as abnormal from performing the insertion operation of a hairpin tube T.

(Modifications of First Embodiment)

In the above-described first embodiment, the heat exchanger tube inserting apparatus1insert hairpin tubes T. However, the present invention is not limited to the insertion of hairpin tubes T. The heat exchanger tube inserting apparatus1can also insert straight tubes having no hairpin portions.

In the above-described first embodiment, the driving roller2aand the driven roller2bexemplify the pair of rollers for sandwiching a hairpin tube T. However, the present invention is not limited to this configuration. A pair of driving rollers which are respectively driven by a motor may alternatively be used. Further, the driving roller2amay be disposed above a hairpin tube T, instead of under the hairpin tube T as shown inFIG. 1.

In the above-described embodiment, the plurality of driving rollers2aare driven by the common motor21. However, the present invention is not limited to this configuration. An individual motor may be provided for each of the driving rollers2a.

In the above-described first embodiment, the roller conveyor section2advances a hairpin tube T in the direction of inserting it into insertion holes P of fins F. However, the configuration may be modified to cause the driving roller2a, in the case where an insertion failure of a hairpin tube T occurs (for example, the case where a hairpin tube T gets caught in insertion holes P and fails to be successfully inserted), to rotate in a reverse direction to allow removal of the hairpin tube T. In that case, the configuration is preferred to allow the driven roller2bto be pushed a little strongly against the hairpin tube T to remove the hairpin tube T, for example, it is preferred to provide an auxiliary cylinder in addition to the second vertical mover12in order to push the driven roller2bdownward.

In the above-described first embodiment, the driving roller2aand the driven roller2bhave the flat respective contact portions2a1and2b1which come into contact with a hairpin tube T. However, the present invention is not limited to this configuration. The driving roller2aand the driven roller2beach may be in the form of a grooved roller having grooves formed in a circumferential portion thereof. Each of the grooves is only necessary to have a shape allowing a part of the straight portion SP of a hairpin tube T to fit therein, and may have a curved shape or a V-shape. Such grooved rollers will make a great friction with a hairpin tube T, which therefore do not need to have an elastically deformable contact portion made of an urethane rubber or the like. On the other hand, they are less versatile and are applicable to hairpin tubes having limited tube diameters. Therefore, in the case of inserting heat exchanger tubes having different tube diameters, it is preferred that the rollers have a flat contact portion as in the above-described embodiment.

In the above-described first embodiment, the pushing cylinder3including vertically aligned two pushing portions3aand3bis illustrated. However, the present invention is not limited to this configuration. A pushing cylinder including vertically aligned three or more pushing portions may alternatively be adopted. In that case, it is possible to set three or more levels of depression amounts.

In the above-described first embodiment, the entanglement eliminator9recedes upward from a hairpin portion HP by the oblique portion9acoming into contact with the hairpin portion HP, and the entanglement eliminator9is pushed downward by the spring22. However, the present invention is not limited to this configuration. An alternative configuration may include a mechanism for automatically vertically moving the entanglement eliminator9. Such a moving mechanism may include, for example, a cylinder for vertically moving the entanglement eliminator9, and a proximity sensor for detecting the approach of the hairpin portion HP of a hairpin tube T to the entanglement eliminator9.

The heat exchanger tube inserting apparatus1according to the first embodiment includes the three roller conveyor sections2and the pushing cylinder3having the pushing plate3a1having a width sufficient to simultaneously push three hairpin portions HP in order to simultaneously insert three hairpin tubes T. However, the present invention is not limited to this configuration. A heat exchanger tube inserting apparatus of the present invention may be so configured as to insert one hairpin tube T, or to simultaneously insert a plurality of, i.e. two or four or more, hairpin tubes T.

Second Embodiment

In the heat exchanger tube inserting apparatus1according to the first embodiment, each of the roller conveyor sections2includes the pair of rollers2aand2bfor vertically sandwiching a hairpin tube T therebetween. However, the present invention is not limited to this configuration. For example, as a second embodiment, each of roller conveyor sections2may include a plurality of (two inFIG. 21) driving rollers2adisposed in an insertion direction Y of hairpin tubes T, and a plurality of driven rollers2bdisposed respectively opposite to the plurality of driving rollers2ain order to exert a greater propulsive force on hairpin tubes T, as in a heat exchanger tube inserting apparatus31shown inFIG. 21.

The plurality of driving rollers2aare so configured as to rotate at the same rotational speed. For example, each of the driving rollers2aincludes a rotary shaft2a2and a pulley32secured to the rotary shaft2a2, and an endless belt (such as timing belt)33is wound around two pulleys32. A motor (not shown) rotates the rotary shaft2a2of one of the plurality of driving rollers2ato thereby transmit a torque to the other driving roller(s)2avia the endless belt33. This enables the plurality of driving rollers2ato rotate at the same rotational speed.

A hairpin tube T is sandwiched by the plurality of driving rollers2aand the plurality of driven rollers2bopposed thereto, to thereby come into contact with the plurality of rollers2aand2bover a larger area than in the first embodiment. This makes the hairpin tube T less likely to slip on the rollers, and therefore a greater propulsive force can be exerted on the hairpin tube T.

It should be noted thatFIG. 21shows the roller conveyor section2including the two driving rollers2a. However, a roller conveyor section2may include three or more driving rollers2aand driven rollers2b. Further, each of the driving rollers2amay be driven by an individual motor.

As a modification of the second embodiment, endless belts45and48may each be wound around rollers in order to allow a roller conveyor section42to come into contact with a hairpin tube T over an even larger area, as in a heat exchanger tube inserting apparatus41shown inFIG. 22.

Such roller conveyor section42includes, for example, a plurality of driving rollers43and44disposed in an insertion direction Y of hairpin tubes T, the endless belt45wound around the driving rollers43and44, a plurality of driven rollers46and47disposed respectively opposite to the plurality of driving rollers43and44, and the endless belt48wound around the driven rollers46and47.

Here, the driving rollers43and44, and the driven rollers46and47are in the form of a cylinder, for example.

One of the driving rollers43and44is rotated by a motor (not shown) to thereby cause the endless belt45wound around the rollers43and44to run.

A hairpin tube T is sandwiched between the endless belt45wound around the driving rollers43and44and the endless belt48wound around the driven roller46and47. This allows the roller conveyor section42to come into contact with the hairpin tube T over a large area as compared to the case without the endless belts45and48. This makes the hairpin tube T even less likely to slip on the rollers, and therefore an even greater propulsive force can be exerted on the hairpin tube T.

Third Embodiment

The above-described first embodiment and second embodiment illustrate examples of so-called parallel insertion in which the straight tube portions SP of a hairpin tube T are inserted into through holes P of each of fins F with the hairpin tube T being in a horizontal state, i.e. the pair of straight tube portions SP of the hairpin tube T being in the state (a horizontal state, seeFIG. 32) of extending horizontally side by side. However, the present invention is not limited to this configuration. The scope of the present invention includes a heat exchanger tube inserting apparatus capable of performing not only parallel insertion, but also so-called oblique insertion of hairpin tubes T in which the straight tube portions SP of a hairpin tube T are inserted into through holes P with the hairpin tube T being in an oblique state (seeFIG. 29), i.e. the pair of straight tube portions SP being in the state of extending at different vertical positions.

Here,FIG. 23shows a heat exchanger E3as an example of a multi-tiered heat exchanger including a tier having a row of hairpin tubes T inserted in parallel and a tier having a row of hairpin tubes T inserted obliquely. The heat exchanger E shown inFIG. 23includes a number of fins F3, and a plurality of hairpin tubes T passing through the number of fins F3. The numbers of fins F3are arranged side by side in the direction perpendicularly intersecting the drawing sheet surface ofFIG. 23. The hairpin tubes T include a plurality of hairpin tubes T1which are inserted obliquely and passing through the number of fins F3, and a plurality of hairpin tubes T2which are inserted in parallel and passing through the number of fins F3.

In a first zone A1of each of the fins F, through holes P1are formed at regular intervals in a longitudinal direction of the fins F3. In a second zone A2, through holes P2are formed at regular intervals at positions respectively spaced apart from the through holes P1in the longitudinal direction of the fins F3. Thus, a through hole P2is located in the middle between adjacent through holes P1in the longitudinal direction of the fins F3. Further, in a third zone A3, through holes P3are formed at positions respectively immediately above the through holes P1.

The through hole P2is disposed, for example, at a position shifted from the through hole P1by 45 degrees upward. In this case, the pitch between a through hole P1and a through hole P2is set to half the pitch between adjacent through holes P3in a horizontal direction.

Each of the hairpin tubes (T1, T2) includes, similarly to the hairpin tube T shown inFIG. 2, a pair of straight tube portions SP extending in parallel to each other, and a hairpin portion HP connecting respective one ends of the straight tube portions SP. Regarding the obliquely inserted hairpin tubes T1, the pair of straight tube portions SP includes a straight tube portion SP disposed at a lower vertical position, and a straight tube portion SP2disposed at a higher vertical position than the straight tube portion SP1.

In the pair of straight tube portions SP of a hairpin tube T1for oblique insertion, one straight tube portion SP1is inserted into a through hole P1formed in the first zone A1and the other straight tube portion SP2is inserted into a through hole P2formed in the second zone A2of each of the fins F3. Consequently, the hairpin tube T1is disposed with the hairpin portion HP being oblique to the longitudinal direction of the fins F3, i.e. the hairpin tube T1is obliquely inserted in through holes P1and P2of each of the fins F3.

On the other hand, a hairpin tube T2for parallel insertion is inserted into through holes P3formed in the third zone A3of each of the fins F3with the pair of straight tube portions SP extending horizontally side by side. Consequently, the hairpin tube T2is disposed with the hairpin portion HP extending in the longitudinal direction of the fins F3, i.e. the hairpin tube T2is inserted in through holes F3of each of the fins F3in parallel.

In order to perform insertion operation of hairpin tubes T1and T2for the multi-tiered heat exchanger E3including the tier having a row of hairpin tubes T (T1) which are inserted obliquely and the tier having a row of hairpin tubes T (T2) which are inserted in parallel, a heat exchanger tube inserting apparatus capable of performing both parallel insertion and oblique insertion of hairpin tubes T1and T2is shown in the following third embodiment.

A heat exchanger tube inserting apparatus51shown inFIG. 24includes a roller conveyor section52for moving hairpin tubes T to a predetermined first position (see the first position I shown inFIG. 2), a guide section53, a roller mover54, a second positioner mover55, a plurality of driven roller vertical movers61, and an upper unit vertical mover62.

The heat exchanger tube inserting apparatus51further includes a pushing cylinder (not shown) for pushing and inserting hairpin tubes T which has been pushed to the predetermined first position I by the roller conveyor section2to a predetermined second position (see the second position II shown inFIG. 20) located further inside than the first position I. The pushing cylinder is, similarly to the pushing cylinder3shown inFIG. 2, disposed at a side of the roller conveyor section52in a horizontal direction perpendicularly intersecting a conveyance direction Y of hairpin tubes T (in the direction perpendicularly intersecting the drawing sheet surface ofFIG. 24). The heat exchanger tube inserting apparatus51further includes, similarly to the heat exchanger tube inserting apparatus1shown inFIG. 1, a main body frame4supporting the roller conveyor section52and the pushing cylinder, and a vertical mover (not shown) for vertically moving the entirety of the main body frame4.

The roller conveyor section52includes, as shown inFIGS. 24, 25 and 28, a rear driving roller56, a plurality of front driving rollers57, a plurality of rear driven rollers58, a plurality of front driven rollers59, and a stand60rotatably supporting the rear driving roller56and the front driving rollers57.

The stand60includes a pair of vertical plates60aand60b. The pair of vertical plates60aand60bstand vertically and extend in the conveyance direction Y of hairpin tubes T1. The pair of vertical plates60aand60bare horizontally spaced apart from each other in the direction perpendicularly intersecting the conveyance direction Y. The pair of vertical plates60aand60bare secured to an unillustrated bottom plate, floor surface or the like.

Each of the vertical plates60aand60bis formed with a long hole60c. The long holes60cextend vertically.

The rear driving roller56is configured by a single cylindrical roller as shown inFIG. 28. The rear driving roller56includes a shaft portion56aextending along its axis C1. The rear driving roller56is within the concept of a first roller of the present invention. The rear driving roller56may alternatively be configured to include a plurality of disc-shaped rollers and a shaft connecting the rollers. The rear driving roller56is rotated by a torque of an unillustrated motor.

The opposite ends of the shaft portion56aof the rear driving roller56are rotatably supported on the pair of vertical plates60aand60bof the stand60at the upstream side of the long holes60cin the conveyance direction Y (at the left side inFIG. 24). In this state, the rear driving roller56is placed in the stand60. This allows the rear driving roller56to extend horizontally in the direction of X (seeFIG. 28) perpendicularly intersecting the conveyance direction Y and along the axis C1.

The rear driving roller56is disposed at a position where it comes into contact with both of the pair of straight tube portions SP of a hairpin tube T being conveyed in the horizontal state of extending horizontally side by side, and with the straight tube portion SP1that is at a lower position in the pair of straight tube portions SP of a hairpin tube T being conveyed in the oblique state of extending side by side at different vertical positions.

Each of the plurality of front driving rollers57includes a main body portion57aconfigured in the form of a disc, and a contact portion57bconfigured in the form of a cylinder and disposed axially adjacent to and coaxially with the main body portion57a. The plurality of front driving rollers57are secured to a common shaft63. The front driving roller57is within the concept of a second roller of the present invention.

The opposite ends of the common shaft63allowing the plurality of front driving rollers57to be secured thereto are inserted in the long holes60cformed in the pair of vertical plates60aand60bof the stand60. The common shaft63is rotatably supported in the long holes60cof the vertical plates60aand60b. Furthermore, the common shaft63is movable in a longitudinal direction of the long holes60c, i.e. vertically, in the long holes60c.

The plurality of front driving rollers57are disposed at positions spaced apart from the rear driving roller56in the conveyance direction Y of hairpin tubes T, i.e. at the downstream side (in front of) the rear driving roller56in the conveyance direction Y. Furthermore, the plurality of front driving rollers57are disposed at regular intervals along an axis C2extending in parallel with the axis C1of the rear driving roller56.

The gap between adjacent main body portions57aof the front driving rollers57is set to correspond to the gap between one straight tube portion SP2and another adjacent straight tube portion SP2, each of the straight tube portions SP2being at a higher position in the pair of straight tube positions SP of a hairpin tube T being conveyed in the oblique state.

The plurality of front driving rollers57are rotated by a torque transmitted from the shaft portion56aof the rear driving roller56via an unillustrated transmission mechanism. The transmission mechanism includes, for example, a combination of a timing belt and a pulley or a combination of a plurality of gears.

The rear driven rollers58are disposed immediately above and opposite to the rear driving roller56. Furthermore, the plurality of rear driven rollers58are disposed at regular intervals along an axis C3extending in parallel with the axis C1of the rear driving roller56. The gap between adjacent rear driven rollers58is set to correspond to the gap between the pair of straight tube portions SP of a hairpin tube T being conveyed in the horizontal state of extending horizontally side by side. Each of the rear driven rollers58includes a shaft portion58aextending along its axis.

The plurality of front driven rollers59are disposed respectively immediately above and opposite to the main body portions57aof the front driving rollers57. Each of the front driven rollers59includes a shaft portion59aextending along its axis C4.

The guide section53guides a hairpin tube T to the roller conveyor section52in the conveyance direction Y, regardless of whether the hairpin tube T is in the oblique state (seeFIG. 29) or in the horizontal state (seeFIG. 32). The guide section53includes an upper unit71and a lower unit72.

The upper unit71includes, as shown inFIGS. 24 and 26, a main body portion73, and a plurality of first positioners74provided to the main body portion73in a vertically movable manner. Each of the first positioners74comes into contact with the pair of straight tube portions SP of a hairpin tube T2being in the horizontal state from above to thereby position the straight tube portions SP, and comes into contact with the straight tube portion SP1of the pair of straight tube portions SP1and SP2that is at a lower position of a hairpin tube T1being in the oblique state from above to thereby position the straight tube portion SP1.

The main body portion73includes a bottom surface73aextending horizontally, and is supported by the upper unit vertical mover62. Further, the main body portion73includes a plurality of grooves73bextending vertically from the bottom surface73a. The plurality of grooves73bextend in the conveyance direction Y of hairpin tubes T. Further, the plurality of grooves73bare disposed at regular intervals in the direction X (seeFIG. 26) perpendicularly intersecting the conveyance direction Y.

Each of the plurality of first positioners74is in the form of a plate. An upper end of each of the first positioners74is inserted in a corresponding one of the grooves73bof the main body portion73and is supported in the groove73bby springs75.

Further, each of the first positioners74includes a bottom surface74bextending horizontally. As shown inFIGS. 29 and 32, when the upper unit71is at a lower position, the bottom surface74bcan come into contact with the straight tube portion SP1that is at a lower position in a hairpin tube T1being in the oblique state, or the straight tube portions SP of a hairpin tube T2being in the horizontal state, from above. Further, an oblique portion74ais formed in a lower portion of the first positioner74at an upstream end thereof in the conveyance direction Y of hairpin tubes T. The oblique portion74aslopes in the direction away from a movement region of hairpin tubes T, for example, in the direction of rising, as proceeding upstream in the conveyance direction Y.

The lower unit72includes, as shown inFIGS. 24 to 26, a case76, a plurality of second positioners77, a plurality of pins78, a plurality of partition plates79. The second positioner77comes into contact with the straight portion SP2that is at a higher position in a pair of straight tube portions SP1and SP2being in the oblique state, from below, to thereby adjust the straight portion SP2to a predetermined vertical position.

The case76includes a pair of vertical plates76aand76b, and a bottom plate76cconnecting the pair of vertical plates76aand76b. The pair of vertical plates76aand76bstand vertically and extend in the conveyance direction Y of hairpin tubes T1. The pair of vertical plates76aand76bare horizontally spaced apart from each other in the direction X (seeFIG. 26) perpendicularly intersecting the conveyance direction Y.

Each of the second positioners77includes an upper member77aand a lower member77bconfigured in the form of a plate, and springs77cdisposed between the upper member77aand the lower member77c. The upper member77ais supported by the springs77cfrom below.

The upper member77aand the lower member77bare formed with long holes77dand long holes77e, respectively, the long holes77dand77eextending vertically.

Further, the upper member77aincludes a top surface77gextending horizontally. As shown inFIG. 29, when the second positioner77is at an upper position, the top surface77gcan come into contact with a straight tube portion SP2that is at a higher position as described above, from below. Further, an oblique portion77fis formed at an upstream end of the upper member77ain the conveyance direction Y of hairpin tubes T. The oblique portion77fslopes in the direction away from the movement region of hairpin tubes T, for example, in the direction of descending, as proceeding upstream in the conveyance direction Y.

Further, the lower member77bincludes two projection portions77hprojecting downward. Each of the projection portions77hhas an oblique surface77ion a downstream side thereof in the conveyance direction Y (on the right side thereof inFIG. 25). The oblique surfaces77islope in the direction of rising as proceeding downstream in the conveyance direction Y. Further, each of the projection portions77hhas a bottom surface77kextending horizontally.

The plurality of second positioners77are placed in the case76with each of the partition plates79being disposed between adjacent second positioners77.

The second positioners77and the partition plates79are connected by the pair of vertical plates76aand76bof the case76and the four pins78.

The pins78are respectively inserted in the long holes77dand77eof each of the second positioners77. This permits each of the second positioners77to move vertically.

A top surface79aof the partition plate79is disposed at a position where it comes into contact with one of the pair of straight portions SP of a hairpin tube T being conveyed in the horizontal state of extending horizontally side by side, and with the straight tube portion SP1that is at a lower position in the pair of straight tube portions SP of a hairpin tube T being conveyed in the oblique state of extending side by side at different vertical positions.

The roller mover54serves as a mechanism for vertically moving the front driving rollers57. The roller mover54includes, as shown inFIGS. 24 and 25, a roller guide member81, and a first guide driver82for moving the roller guide member81in the conveyance direction Y.

The roller guide member81includes, as shown inFIGS. 25 and 28, a bottom plate81a, and a plurality of vertical plates81bdisposed on a top surface of the bottom plate81a.

Each of the vertical plates81bis disposed at a position where it comes into contact with a corresponding one of the cylindrical contact portions57bof the front driving rollers57from below.

Each of the vertical plates81bhas a top surface including a guide surface81cextending obliquely, a lower position determining surface81dfor determining a lower position of the corresponding front driving roller57, and the upper position determining surface81efor determining an upper position of the corresponding front driving roller57. The guide surface81cslopes in the direction of changing the distance to the movement region of hairpin tubes T1as proceeding upstream in the conveyance direction Y of hairpin tubes T1, for example, in the direction of rising as proceeding downstream in the conveyance direction Y. The lower position determining surface81dhorizontally extends upstream in the conveyance direction Y from a lower end of the guide surface81c. The upper position determining surface81ehorizontally extends downstream in the conveyance direction Y from an upper end of the guide surface81c.

The first guide driver82moves the roller guide member81so as to raise the front driving rollers57by the guide surfaces81cof the roller guide member81. Specifically, the first guide driver82includes a rod82aextending in the conveyance direction Y, and a cylinder82bfor moving the rod82aforward and backward in the conveyance direction Y. The leading end of the rod82ais connected with the roller guide member81. The rod82ais moved horizontally by the pressure of working fluid such as compressed air supplied into the cylinder82b. Thus, the roller guide member81is moved forward and backward in the conveyance direction Y by the first guide driver82.

As shown inFIGS. 24 and 25, the above-described roller mover54can move the front driving rollers57from the predetermined lower position (seeFIG. 24) at which the respective cylindrical contact portions57bcome into contact with the corresponding lower position determining surfaces81dof the roller guide member81, to the predetermined upper position (seeFIG. 27). Specifically, when the roller guide member81is moved upstream in the conveyance direction Y by the first guide driver82, the contact portions57bof the front driving rollers57are pushed upward by the guide surfaces81cof the roller guide member81in an upward direction Z. In this manner, the front driving rollers57can be raised. The raised front driving rollers57are set at the predetermined upper position shown inFIG. 27by the respective contact portions57bcoming into contact with the upper position determining surfaces81eof the roller guide member81. On the contrary, when the roller guide member81is moved downstream in the conveyance direction Y, the front driving rollers57descend to return to the above-mentioned predetermined lower position (seeFIG. 24).

As shown inFIGS. 25 and 26, the second positioner mover55serves as a mechanism for moving the second positioners77between the upper position at which they positions straight tube portions SP and the lower position to which they recede downward from the movement region of hairpin tubes T.

The second positioner mover55specifically includes a guide member84, and a second guide driver85for moving the guide member84in the conveyance direction Y.

The guide member84includes a bottom plate84a, and a plurality of vertical plates84bprovided on a top surface of the bottom plate84a.

The bottom plate84ahas a top surface including a lower position determining surface84dfor determining a lower position of the second positioners77.

The plurality of vertical plates84bare disposed at positions to come into contact with the lower members77bof the second positioners77from below. In other words, the plurality of vertical plates84bare disposed horizontally at regular intervals in the direction X (seeFIG. 26) perpendicularly intersecting the conveyance direction Y and respectively lie under the second positioners77.

Further, two vertical plates84bare aligned in the conveyance direction Y as shown inFIG. 25. As shown inFIG. 25, when the second positioner77is at the lower position, the two projection portions77hprojecting downward in the second positioner77are engaged with the two vertical plates84b.

Each of the plate portions of the vertical plate84bhas a guide surface84con an upstream side thereof in the conveyance direction Y. The guide surface84cslopes in the direction of descending as proceeding upstream in the conveyance direction Y. The oblique angle of the guide surface84cis set so as to agree with the oblique angle of the oblique surface77iof the projection portion77hof the second positioner77.

Further, each of the plate portions of the vertical plate84bhas a top surface including an upper position determining surface84efor determining an upper position of the corresponding second positioner77. The upper position determining surface84eextends horizontally downstream in the conveyance direction Y from an upper end of the guide surface84c. A lower end of the guide surface84cjoins the lower position determining surface84dof the bottom plate84a.

The second guide driver85includes a rod85aextending in the conveyance direction Y, and a cylinder85bfor moving the rod85aforward and backward in the conveyance direction Y. The guide member84is secured to the leading end of the rod85a. The rod85ais moved horizontally by the pressure of working fluid such as compressed air supplied into the cylinder85b. Thus, the roller guide member84is moved forward and backward in the conveyance direction Y by the second guide driver85.

As shown inFIGS. 24 and 25, the above-described second positioner mover55can move the second positioners77from the predetermined lower position at which the respective projection portions77hcome into contact with the lower position determining surface84dof the guide member84, to the predetermined upper position. Specifically, when the guide member84is moved upstream in the conveyance direction Y by the second guide driver85, the oblique surfaces77iof each of the second positioners77come into contact with the guide surfaces84cof the corresponding one of the vertical plates84bof the guide member84. In this manner, the second positioners77are pushed upward by the vertical plates84bof the guide member84. The second positioners77can be thus raised. When the second positioners77are raised, the bottom surfaces77kof the projection portions77hof each of the second positioners77come into contact with the upper position determining surfaces84eof the corresponding one of the vertical plates84bof the guide member84. This allows the second positioners77to be set at the predetermined upper position shown inFIG. 27. On the contrary, when the roller guide member84is moved downstream in the conveyance direction Y, the second positioners77descend to return to the above-mentioned predetermined lower position (seeFIGS. 24 and 25).

Each of the plurality of driven roller vertical movers61includes, as shown inFIGS. 24 and 28, a roller support portion91, a rod92connected to the roller support portion91, and a cylinder93for moving the rod92vertically.

The roller support portion91includes a rear bearing91aand a front bearing91b. The rear bearing91arotatably supports the shaft portion58aof a corresponding one of the rear driven rollers58at a position immediately above the shaft portion56aof the rear driving roller56. The front bearing91bis located at the downstream side of the rear bearing91ain the conveyance direction Y. The front bearing91brotatably supports the shaft portion59aof a corresponding one of the front driven rollers59at a position immediately above the common shaft63supporting the front driving rollers57.

The front bearing91bis located at a higher position than the rear bearing91a. The vertical difference between the front bearing91band the rear bearing91ais set to be equal to the vertical difference which occurs between the common shaft63supporting the front driving rollers57and the shaft portion56aof the rear driving roller56when the front driving rollers57are at the upper position (seeFIG. 27).

The rod92extends vertically. The rod has a bottom end connected to the roller support portion91. The rod92is moved vertically by the pressure of working fluid such as compressed air supplied into the cylinder93. The cylinder93is secured to an upper mounting board4bof the main body frame4of the heat exchanger tube inserting apparatus51, similarly to the cylinder13eshown inFIG. 1.

The upper unit vertical mover62includes a support portion94supporting the main body portion73of the upper unit71of the guide section53, a rod95connected to the support portion94, and a cylinder96for moving the rod95vertically. The rod95extends vertically. The rod95has a lower end connected to the support portion73. The rod95is moved vertically by the pressure of working fluid such as compressed air supplied into the cylinder96. The cylinder96is secured to, for example, the upper mounting board4bof the main body frame4of the heat exchanger tube inserting apparatus51.

Now, a method of oblique insertion and parallel insertion of hairpin tubes T using the heat exchanger tube inserting apparatus51having the above-described configuration will be described.

First, description will be made on a method of obliquely inserting hairpin tubes T1each into a through hole P1formed in the first zone A1and a through hole P2formed in the second zone A2of each of the fins F3of the heat exchanger E3shown inFIG. 23(i.e. inserting the pair of straight tube portions SP1and SP2of each of hairpin tubes T1into through holes P1and P2at different vertical positions).

In the initial state before oblique insertion of hairpin tubes T1, as shown inFIGS. 24 to 26, the plurality of front driving rollers57are at the predetermined lower position to which they recede downward from the movement region of hairpin tubes T1. Further, the second positioners77of the guide section53are also at the predetermined lower position to which they recede from the movement region of hairpin tubes T1. Further, each of the pluralities of rear driven rollers58and front driven rollers59is at a predetermined upper position to which they recede upward from the movement region of hairpin tubes T1. Further, the upper unit71of the guide section53is at a predetermined upper position to which it recedes upward from the movement region of hairpin tubes T1. Further, the entirety of the heat exchanger tube inserting apparatus51is at a position to which it recedes horizontally in the direction perpendicularly intersecting the conveyance direction Y of hairpin tubes T1(for example, the position of the heat exchanger tube inserting apparatus1to which it recedes from the hairpin tubes T disposed at the initial position N in the direction perpendicularly intersecting the conveyance direction Y, which is shown inFIG. 2).

In this state, an operator inserts, in advance, respective leading ends of the straight tube portions SP1and SP2of each of a plurality of (for example, five) hairpin tubes T1into through holes P1and P2formed in a front fin3of the number of fins3of the heat exchanger E3, to thereby set the hairpin tubes T1at an initial position. Consequently, the straight tube portions SP and SP2of each of the hairpin tubes T1are temporarily set at the initial position by the through holes P1and P2located at different vertical positions.

After the hairpin tubes T1are set at the initial position, the heat exchanger tube inserting apparatus51is moved to approach the hairpin tubes T1horizontally in the direction perpendicularly intersecting the conveyance direction Y of hairpin tubes T1. Consequently, the hairpin tubes T1are disposed between the lower rollers56and57and the upper rollers58and59of the roller conveyor section52, as shown inFIGS. 24 to 26. At the same time, the hairpin tubes T1are disposed between the upper unit71and the lower unit72of the guide section53.

In the state shown inFIGS. 24 to 26, the lower straight tube portion SP1of each of the hairpin tubes T1is placed on the top surface79aof a corresponding one of the partition plates79of the guide section53and, on the other hand, the higher straight tube portion SP2of each of the hairpin tubes T1is at a position apart upward from a corresponding one of the second positioners77.

Thereafter, as shown inFIGS. 27 to 29, the pair of straight tube portions SP1and SP2of each of the hairpin tubes T1are vertically sandwiched by corresponding four rollers56to59of the roller conveyor section52, and also vertically sandwiched by the upper unit71and the lower unit72of the guide section53.

At this time, the roller guide member81of the roller mover54is moved upstream in the conveyance direction Y by the first guide driver82to push the respective contact portions57bof the front driving rollers57in the upward direction Z by the guide surfaces81cof the roller guide member81. This allows the plurality of front driving rollers57to move to the predetermined upper position. Consequently, the front driving rollers57support the upper straight portions SP2from below.

Further, the guide member84of the guide driver55is moved upstream in the conveyance direction Y by the second guide driver85to bring the guide surfaces84cof each of the vertical plates84bof the guide member84into contact with the oblique surfaces77iof the corresponding one of the second positioners77. This allows the vertical plates84bof the guide member84to push the second positioners77upward. In this manner, the second positioners77of the lower unit72of the guide section53are moved to the predetermined upper position. Consequently, the top surface77gof the upper member77aof each of the second positioners77comes into contact with the corresponding upper straight tube portion SP2and supports it from below.

Further, the plurality of rear driven rollers58and the plurality of front driven rollers59are lowered by the driven roller vertical mover61. Consequently, the rear driven rollers58respectively sandwich the lower straight tube portions SP1with the single cylindrical rear driving roller56. At the same time, the front driven rollers59and the front driving rollers57opposed thereto sandwich the upper straight tube portions SP2.

Further, the upper unit71of the guide section53is lowered by the upper unit vertical mover62. Consequently, the bottom surface73aof the main body portion73is disposed at a position where it is in contact with the upper straight tube portions SP2or a position close thereto. Further, the bottom surface74bof each of the first positioners74is disposed at a position where it is in contact with the corresponding lower straight tube portion SP1or a position close thereto.

Consequently, as shown inFIGS. 27 and 29, in the guide section53, a guide passage101extending in the conveyance direction Y is defined by the top surface79aof a partition plate79, the bottom surface74bof the corresponding first positioner74, and adjacent side surfaces of the second positioners77located on both sides thereof. Each lower straight tube portion SP1is guided in the conveyance direction Y by the guide passage101. Further, a guide passage102extending in the conveyance direction Y is defined by the top surface77gof a second positioner77, the bottom surface73aof the main body portion73, and adjacent side surfaces of the first positioners74located on both sides thereof. Each upper straight tube portion SP2is guided in the conveyance direction Y by the guide passage102.

Thereafter, in the above-described state, the rear driving roller56and the front driving rollers57of the roller conveyor section52are driven for rotation by an unillustrated motor to thereby convey the hairpin tubes T1being in the oblique state in the conveyance direction Y to the predetermined first position, whereby the hairpin tubes T1are inserted into the middle of the number of fins F3of the heat exchanger E3.

At this time, in the pair of straight tube portions SP1and SP2of each of the hairpin tubes T1, the lower straight tube portion SP1is conveyed in the conveyance direction Y while being guided by the above-described guide passage101in the guide section53and sandwiched by the rear driving roller56and the rear driven roller58. On the other hand, the upper straight tube portion SP2is conveyed in the conveyance direction Y while being guided by the above-described guide passage102in the guide section53and being sandwiched by the front driving roller57and the front driven roller59. At this time, as shown inFIG. 29, a part of each of the first positioner74and the second positioner77gets into the space between the straight tube portions SP1and SP2to thereby function as an entanglement eliminator for eliminating entanglement between the straight tube portions SP1and SP2.

When the hairpin portion HP passes the guide section53, the first positioner74and the second positioner77recede from the movement region of hairpin tubes T1. Specifically, when the hairpin portion HP moves in the conveyance direction Y and reaches the guide section53, the hairpin portion HP comes into contact with the oblique portion74aof the first positioner74and pushes the first positioner74against the restoring force of the springs75to cause it to recede upward from the hairpin tube T1. At the same time, the hairpin portion HP comes into contact with the oblique portion77fof the upper member77aof the second positioner77and pushes the upper member77adownward against the restoring force of the springs77cto cause it to recede downward from the hairpin tube T1. After the hairpin portion HP passes the first positioner74and the upper member77a, the first positioner74and the upper member77areturn to their initial positions occupied before the passage of the hairpin portion HP.

When movement of the hairpin tubes T1to the predetermined first position is completed by passage of the hairpin portions HP through the guide section53, rotation of the rear driving roller56and the front driving rollers57is stopped.

Thereafter, in the reverse sequence to that described above, the plurality of front driving rollers57and the second positioners77are caused to recede downward from the movement region of hairpin tubes T1. At the same time, the plurality of rear driven rollers58and the plurality of front driven rollers59are raised to recede upward from the movement region of hairpin tubes T1. Further, the upper unit71of the guide section53is raised to recede upward.

Thereafter, the heat exchanger tube inserting apparatus51is moved horizontally in the direction perpendicularly intersecting the conveyance direction Y of hairpin tubes T1to locate the above-mentioned unillustrated pushing cylinder at the upstream side of the hairpin tubes T1in the conveyance direction Y. Thereafter, the hairpin tubes T1are inserted into the predetermined second position by the pushing cylinder. In this manner, the hairpin tubes T1are inserted into the end of the number of fins F3of the heat exchanger E3, whereby the oblique insertion of the hairpin tubes T1is completed.

Now, description will be made on a method of inserting hairpin tubes T2in parallel each into through holes P3formed in the third zone A3of each of the fins F3of the heat exchanger E3shown inFIG. 23(i.e. inserting each of hairpin tubes T2into through holes P3with the pair of straight tube portions SP being in the state of extending horizontally side by side).

In the same manner as in the case of oblique insertion described above, an operator sets, in advance, each of hairpin tubes T2at an initial position at which respective leading ends of the pair of straight tube portions SP are inserted in through holes P3formed in a front sheet of the number of fins3. In the case of parallel insertion, the pair of straight tube portions SP is temporarily set at the initial position by the through holes P3which are adjacent at the same vertical position.

After the hairpin tubes T2are set at the initial position, the heat exchanger tube inserting apparatus51is moved to approach the hairpin tubes T2horizontally in the direction perpendicularly intersecting the conveyance direction Y of hairpin tubes T2.

Thereafter, in the same manner as in the case of oblique insertion, as shown inFIGS. 30 to 32, the pairs of straight tube portions SP of the hairpin tubes T2are vertically sandwiched by rollers of the roller conveyor section52(in the parallel insertion, only by the rear driving roller56and the rear driven rollers58). Further the pairs of straight tube portions SP are vertically sandwiched by the upper unit71and the lower unit72of the guide section53.

Specifically, the plurality of rear driven rollers58are lowered with the plurality of front driven rollers59by the driven roller vertical mover61. Consequently, the rear driven rollers58respectively sandwich the pairs of straight tube portions SP with the single cylindrical rear driving roller56.

At this time, the front driving rollers57have moved to the predetermined upper position by the roller mover54in the same manner as in the case of oblique insertion. However, the front driving rollers57and the front driven rollers59do not contribute to supporting the straight tube portions SP. In addition, each of the raised front driving rollers57is located at the gap between the pair of straight tube portions SP, and therefore does not come into contact with the straight tube portions SP.

In the case of parallel insertion, the front driving rollers57may be made to remain at the lower position without being moved to the upper position.

Further, the upper unit71of the guide section53is lowered by the upper unit vertical mover62. Consequently, the bottom surface74bof each of the first positioners74is disposed at a position where it is in contact with a corresponding one of the straight tube portions SP or a position close thereto.

Consequently, as shown inFIGS. 30 and 32, in the guide section53, a guide passage103extending in the conveyance direction Y is defined by the top surface79aof a partition plate79, the bottom surface74bof the corresponding first positioner74, and adjacent side surfaces of the second positioners77located on both sides thereof. Each straight tube portion SP is guided in the conveyance direction Y by the guide passage103. It should be noted that, as shown inFIG. 32, among the pairs of straight tube portions SP, the straight tube portion SP located above the vertical plate76aof the case76of the lower unit72of the guide section53is restrained from upward movement by the vertical plate76aand a downward projection73cof the main body portion73of the upper unit71.

Thereafter, in the above-described state, the rear driving roller56and the front driving rollers57of the roller conveyor section52are driven for rotation by the unillustrated motor to convey the hairpin tubes T2in the horizontal state in the conveyance direction Y to the predetermined first position, for example, a position at which the respective hairpin portions HP of the hairpin tubes T2are between the guide section53and the roller conveyor section52, whereby the hairpin tubes T2are inserted into the middle of the number of fins F3of the heat exchanger E3.

At this time, the pair of straight tube portions SP of each of the hairpin tubes T2is conveyed in the conveyance direction Y while each being guided by the above-described guide passages103in the guide section53and sandwiched by the rear driving roller56and the rear driven roller58. At this time, as shown inFIG. 32, a part of each of the second positioners77gets into the space between a corresponding one of the pairs of straight tube portions SP to thereby function as an entanglement eliminator for eliminating entanglement between the straight tube portions SP.

When the hairpin portion HP passes the guide section53, the second positioner77recedes from the movement region of hairpin tubes T2. Specifically, when the hairpin portion HP moves in the conveyance direction Y and reaches the guide section53, the hairpin portion HP comes into contact with the oblique portion77fof the upper member77aof the second positioner77and pushes the upper member77adownward against the restoring force of the springs77cto cause it to recede downward from the hairpin tube T2. After the hairpin portion HP passes the upper member77a, the upper member77areturns to its initial position occupied before the passage of the hairpin portion HP.

When movement of the hairpin tubes T2to the predetermined first position is completed by passage of the hairpin portions HP through the guide section53, rotation of the rear driving roller56and the front driving rollers57is stopped.

Thereafter, in the same manner as in the case of oblique insertion, the hairpin tubes T2are inserted into the predetermined second position by the pushing cylinder. In this manner, the hairpin tubes T2are inserted into the end of the number of fins F3of the heat exchanger E3, whereby the parallel insertion of the hairpin tubes T2is completed.

In the heat exchanger tube inserting apparatus51according to the third embodiment, the roller conveyor section52includes the rear driving roller56and the front driving rollers57. In the case where the straight tube portions SP in each pair are in the horizontal state of extending horizontally side by side as in hairpin tubes T2for parallel insertion, the rear driving roller56comes into contact with the straight tube portions SP in the pairs. Further, in the case where the straight tube portions SP and SP2in each pair are in the oblique state of extending side by side at different vertical positions as in hairpin tubes T1for oblique insertion, the rear driving roller56comes into contact with the straight tube portions SP1that are at lower positions. In the case where the straight tube portions SP and SP2in each pair are in the oblique state as in hairpin tubes T1for oblique insertion, the front driving rollers57respectively come into contact with the straight tube portions SP2that are at higher positions. This makes it possible to convey the straight tube portions SP (SP1and SP2) of each of hairpin tubes T (T1, T2) in the conveyance direction Y, by bringing only the rear driving roller56or both of the rear driving roller56and the front driving rollers57into contact with the straight tube portions SP (SP1and SP2) depending on whether the hairpin tubes T (T1, T2) are inserted in parallel or obliquely. In this manner, the single heat exchanger tube inserting apparatus51is capable of performing both parallel insertion and oblique insertion of hairpin tubes T (T1, T2).

In the heat exchanger tube inserting apparatus51according to the third embodiment, the rear driving roller56and the front driving rollers57are disposed at different positions in the conveyance direction Y of hairpin tubes T1. This can prevent the rear driving roller56and the front driving rollers57from coming into contact with each other.

The heat exchanger tube inserting apparatus51according to the third embodiment includes the roller mover54for vertically moving the front driving rollers57. Therefore, the front driving rollers57can be made to recede from the movement region of hairpin tubes T (T1, T2) each time an insertion operation of hairpin tubes T (T1, T2) is completed.

In the heat exchanger tube inserting apparatus51according to the third embodiment, the roller mover54includes the roller guide member81having the guide surfaces81csloping in the direction of changing the distance to the movement region of hairpin tubes T (T1, T2) as proceeding upstream in the conveyance direction Y of hairpin tubes T, and the first guide driver82for moving the roller guide member81in the conveyance direction Y. The first guide driver82moves the roller guide member81so as to raise the front driving rollers57by the guide surfaces81cof the roller guide member81. This allows the common shaft63, which serves as a rotary axis of the front driving rollers57and comes into contact with the guide surfaces81c, to be reliably moved vertically according to horizontal movement of the roller guide member81. Furthermore, the roller mover54can be configured to have a relatively low height.

The heat exchanger tube inserting apparatus51according to the third embodiment includes the first positioners74and the second positioners77. Each of the first positioners74positions, in the case where a pair of straight tube portions SP are in the horizontal state as in a hairpin tube T2for parallel insertion, the straight tube portions SP, and in the case where a pair of straight tube portions SP1and SP2are in the oblique state as in a hairpin tube T1for oblique insertion, the straight tube portion SP1that is at a lower position. Each of the second positioners77positions, in the case where a pair of straight tube portions SP1and SP2are in the oblique state as in a hairpin tube T1for oblique insertion, the straight tube portion SP2that is at a higher position. This makes it possible to position the pairs of straight tube portions SP only by the first positioners74in the case of parallel insertion of hairpin tubes T2and position the pairs of straight tube portions SP1and SP2by the first positioners74and the second positioners77in the case of oblique insertion of hairpin tubes T1.

In the heat exchanger tube inserting apparatus51according to the third embodiment, in the case where a pair of straight tube portions SP are in the horizontal state as in a hairpin tube T2for parallel insertion, the second positioner77functions as an entanglement eliminator for eliminating entanglement between the straight tube portions SP. Thus, it is possible to eliminate entanglement between straight tube portions SP being in the horizontal state.

In the heat exchanger tube inserting apparatus51according to the third embodiment, in the case where a pair of straight tube portions SP1and SP2are in the oblique state as in a hairpin tube T1for oblique insertion, a part of each of the first positioner74and the second positioner77functions as an entanglement eliminator for eliminating entanglement between the straight tube portions SP1and SP2. Thus, it is possible to eliminate entanglement between straight tube portions SP1and SP2being in the oblique state.

In the heat exchanger tube inserting apparatus51according to the third embodiment, the first positioner74and the second positioner77include the oblique portions74aand77f, respectively, the oblique portions sloping in the direction away from the movement region of hairpin tubes as proceeding upstream in the conveyance direction Y. The oblique portions74aand77fcome into contact with the hairpin portion HP of a hairpin tube T (T1, T2) being conveyed in the conveyance direction Y to thereby allow the first positioner74and the second positioner77to recede from the hairpin portion HP. This makes the hairpin portion HP less likely to be interrupted by the first positioner74and the second positioner77when it passes by the first positioner74and the second positioner77.

The heat exchanger tube inserting apparatus51according to the third embodiment further includes the second positioner mover55for moving the second positioners77between the upper position at which they position the straight tube portions SP2each being at a higher position in a hairpin tube T for oblique insertion, and the lower position to which they recede from the movement region of hairpin tubes T (T1, T2). Therefore, the second positioners77can be made to recede from the movement region of hairpin tubes T (T1and T2) each time an insertion operation of hairpin tubes T (T1and T2) is completed.

(Modification of Third Embodiment)

In the third embodiment, the first guide driver82for moving the roller guide member81and the second guide driver85for moving the guide member84are included independently of each other. However, the present invention is not limited to this configuration. For example, one of the two guide drivers82and84may be omitted to configure the remaining other driver to move the roller guide member81and the guide member84simultaneously in the conveyance direction Y.

The above-described specific embodiments mainly include the invention configured as follows.

A heat exchanger tube inserting apparatus1or51according to one of the first to third embodiments is configured to insert, in a process of assembling a heat exchanger including a number of fins and heat exchanger tubes passing through the number of fins, a heat exchanger tube into insertion holes formed in the fins, the heat exchanger tube inserting apparatus1or51comprising: a roller conveyor section2or52including rollers2aand2bor56and57for advancing the heat exchanger tube to thereby insert the heat exchanger tube into the insertion holes of the fins and to a first position by rotation of the rollers2aand2bor56and57; and a pushing section3for pushing the heat exchanger tube which has been moved to the first position by the roller conveyor section2or52to a second position located further inside than the first position.

The heat exchanger tube inserting apparatus1or51according to one of the first to third embodiments includes the roller conveyor section2or52and the pushing section3, as a mechanism for advancing a heat exchanger tube into insertion holes of fins in two steps. Therefore, as long as an operator sets, in advance, a heat exchanger tube at a predetermined initial position, for example, an initial position at which a leading end of the heat exchanger tube is inserted in an insertion hole of a front fin of the number of fins, it is possible to advance the heat exchanger tube to thereby insert it into insertion holes of the number of fins to the first position by rotation of the rollers2aand2bor56and57of the roller conveyor section2or52, and subsequently push the heat exchanger tube to thereby insert it to the second position by the pushing section3. Therefore, different from the conventional heat exchanger tube inserting apparatus, it does not require a heat exchanger tube inserting means having such a long stroke length as to fully insert a heat exchanger tube into insertion holes of a number of fins, nor guide rods being so long as to pass through the number of fins for supporting the heat exchanger tube. Consequently, the heat exchanger tube inserting apparatus1or51can be made small in size.

Further, the heat exchanger tube inserting apparatus1or51of the present invention requires an operator to set a heat exchanger tube at the initial position in advance. However, because of being a semi-automatic machine, the heat exchanger tube inserting apparatus1or51can be configured extremely simply with the combination of the roller conveyor section2or52and the pushing section3.

Furthermore, the above-described configuration makes it possible to advance a heat exchanger tube having a desired length, by advancing the heat exchanger tube by rotation of the rollers2aand2bor56and57of the roller conveyor section2or52. Therefore, provision of a stroke length can be eliminated, and heat exchanger tubes of various lengths and various tube diameters (outer diameters) can be inserted. Therefore, it is possible to insert even an extremely long heat exchanger tube into insertion holes of fins.

It is preferred that the heat exchanger tube is in the form of a hairpin tube including a pair of straight tube portions extending in parallel to each other and a hairpin portion connecting respective one ends of the straight tube portions, and it is preferred that the heat exchanger tube inserting apparatus further comprises an entanglement eliminator9disposed upstream of the rollers2aand2bin a heat exchanger tube conveyance direction for eliminating entanglement between the straight tube portions conveyed by the rollers2aand2b.

According to such configuration, the entanglement eliminator9disposed upstream of the rollers2aand2bin the conveyance direction of a hairpin tube eliminates entanglement between the straight tube positions of a hairpin tube before the hairpin tube is inserted into insertion holes of fins by rotation of the rollers2aand2b, the hairpin tube being to serve as a heat exchanger tube. This makes the hairpin tube more likely to be successfully inserted without being interrupted by the rollers2aand2b.

It is preferred that the entanglement eliminator9includes an oblique portion9asloping in a direction away from a hairpin tube movement region as proceeding upstream in the conveyance direction and the entanglement eliminator9is configured to recede from a hairpin portion when the hairpin portion comes into contact with the oblique portion9a.

According to such configuration, in the course of advancement of a hairpin tube into insertion holes of fins by rotation of the rollers2aand2b, the oblique portion9aof the entanglement eliminator9can come into contact with the hairpin portion to thereby allow the entanglement eliminator9to recede upward from the hairpin portion when the hairpin portion passes the entanglement eliminator9. This makes the hairpin portion less likely to be interrupted by the entanglement eliminator9.

It is preferred that the rollers2aand2binclude respective contact portions2a1and2b1able to come into contact with a heat exchanger tube, the contact portions each having a flat part made of an elastic material elastically deformable to make surface contact with the heat exchanger tube when coming into contact with the heat exchanger tube.

According to such configuration, the respective contact portions2a1and2b1of the rollers2aand2bthat come into contact with a heat exchanger tube each have a flat part elastically deformable to make surface contact with the heat exchanger tube when coming into contact with the heat exchanger tube. This makes it possible to reliably advance a heat exchanger tube into insertion holes of fins by rotation of the rollers2aand2baccording to an outer diameter of the heat exchanger tube. Furthermore, the elastic deformation of the rollers2aand2bmakes the heat exchanger tube less likely to be deformed or damaged.

It is preferred that the pushing section3includes a plurality of pushing portions3aand3band differentiates a pushing amount of heat exchanger tube into insertion holes of fins by the plurality of pushing portions from a pushing amount of heat exchanger tube by one of the plurality of pushing portions.

According to such configuration, the pushing section3can push a heat exchanger tube over different distances by use of the plurality of pushing portions3aand3b. Specifically, it is possible to push a heat exchanger tube over a predetermined distance by use of the pushing portion3a. Further, it is possible to push a heat exchanger tube over a distance longer than the above-mentioned predetermined distance by simultaneous operation of the pushing portions3aand3b. Therefore, even in the case where one tier includes a row of heat exchanger tubes having a different effective length from another tier in assembling of a heat exchanger including the tiers, it is possible to insert one tier of heat exchanger tubes in a different stroke length from another tier to thereby accord with the effective length.

It is preferred to further comprise a first guide member7disposed upstream of the rollers2aand2bin the heat exchanger tube conveyance direction for positioning a heat exchanger tube with respect to the rollers2aand2b.

According to such configuration, the first guide member7positions a heat exchanger tube with respect to the rollers2aand2bat the upstream side of the rollers2aand2bin the heat exchanger tube conveyance direction. This makes the heat exchanger tube less likely to reach the rollers2aand2bobliquely to the predetermined conveyance direction.

It is preferred that a plurality of roller conveyor sections2are disposed in parallel to each other in the heat exchanger tube conveyance direction, and that a plurality of first guide members7are respectively disposed upstream of the roller conveyor sections2.

According to such configuration including the plurality of roller conveyor sections, the first guide members7are respectively disposed upstream of the roller conveyor sections2in the heat exchanger tube conveyance direction. This allows each of the first guide members7to accurately position a heat exchanger tube which is to be advanced by the corresponding roller conveyor section2, with respect to the rollers2aand2b. This makes, in insertion of a plurality of heat exchanger tubes by the plurality of roller conveyor sections2, each of the heat exchanger tubes less likely to reach the corresponding driving rollers2aand2bobliquely to the predetermined conveyance direction.

It is preferred to further comprise a second guide member8disposed upstream of the first guide member7in the heat exchanger tube conveyance direction for positioning a heat exchanger tube with respect to the first guide member7.

According to such configuration, it is possible to position a heat exchanger tube with respect to the first guide member7by the second guide member8at the upstream side of the first guide member7in the heat exchanger tube conveyance direction before the heat exchanger tube is advanced to the first guide member7. This makes the heat exchanger tube even less likely to reach the rollers2aand2bobliquely to the predetermined conveyance direction.

It is preferred that the roller conveyor section2includes a pair of rollers2aand2bwhich are oppositely disposed across a heat exchanger tube.

Such configuration allows the pair of rollers2aand2bto reliably advance a heat exchanger tube into insertion holes of fins while vertically sandwiching the heat exchanger tube therebetween.

It is preferred that the pair of rollers includes the driving roller2afor advancing a heat exchanger tube, and the driven roller2bable to come into contact with the heat exchanger tube and rotate with the advancing movement of the heat exchanger tube.

According to such configuration, the provision of one driving roller2aallows simplification of the mechanism. Furthermore, the driven roller2bwhich is simpler in the mechanism can be moved easily between a position at which the driven roller2bcomes into contact with a heat exchanger tube and a position to which the driven roller2brecedes from the heat exchanger tube.

It is preferred that the roller conveyor section52includes two rollers56and57, that the heat exchanger tube is in the form of a hairpin tube including a pair of straight tube portions extending in parallel to each other and a hairpin portion connecting respective one ends of the straight tube portions, and that the two rollers include the first roller56configured to come into contact with the pair of straight tube portions in a case where the pair of straight tube portions are in a horizontal state of extending horizontally side by side, and come into contact with one of the pair of straight tube portions that is at a lower position in a case where the pair of straight tube portions are in an oblique state of extending side by side at different vertical positions, and the second roller57configured to come into contact with the other of the pair of straight tube portions that is at a higher position in the case where the pair of straight portions are in the oblique state.

According to such configuration, it is possible to convey the straight tube portions of a hairpin tube in the conveyance direction by bringing only the first roller56or both of the first roller56and the second roller57into contact with the straight tube portions, depending on whether the straight tube portions are inserted in the horizontal state of extending horizontally side by side (in so-called parallel insertion) or in the oblique state of extending side by side at different vertical positions (in so-called oblique insertion). In this manner, the single heat exchanger tube inserting apparatus51is capable of performing both parallel insertion and oblique insertion of a hairpin tube.

It is preferred that the first roller56and the second roller57are disposed at different positions in the heat exchanger tube conveyance direction. This disposition can prevent the rear driving roller56and the front driving roller57from coming into contact with each other.

It is preferred to further comprise a roller mover54for moving the second roller57vertically.

According to such configuration, with the roller mover54, the front driving roller57can be made to recede from the hairpin tube movement region each time an insertion operation of a hairpin tube is completed.

It is preferred that the roller mover54includes a roller guide member81having a guide surface81csloping in a direction of changing a distance relative to the hairpin tube movement region as proceeding upstream in the heat exchanger tube conveyance direction, and a guide mover82for moving the roller guide member81in the conveyance direction, and the guide mover82is configured to move the roller guide member81so as to raise the second roller57by the guide surface81cof the roller guide member81.

According to such configuration, it is possible to reliably vertically move a rotary axis of the second roller57which comes into contact with the guide surface81caccording to horizontal movement of the roller guide member81. Furthermore, the roller mover54can be configured to have a relatively low height.

It is preferred to further comprise a first positioner74for positioning a pair of straight tube portions in the case where the pair of straight tube portions are in the horizontal state and positioning one of a pair of straight tube portions that is at a lower position in the case where the pair of straight tube portions are in the oblique state, and a second positioner77for positioning the other of the pair of straight tube portions that is at a higher position in the case where the pair of straight tube portions are in the oblique state.

According to such configuration, in the case of parallel insertion of a hairpin tube, it is possible to position the pair of straight tube portions only by the first positioner74. On the other hand, in the case of oblique insertion of a hairpin tube, it is possible to position the pair of straight tube portions by the first positioner74and the second positioner77.

It is preferred to configure the second positioner77to function as, in the case where a pair of straight tube portions are in the horizontal state, an entanglement eliminator of eliminating entanglement between the straight tube portions.

According to such configuration, it is possible to eliminate entanglement between straight tube portions being in the horizontal state.

It is preferred to configure a part of the first positioner74and a part of the second positioner77to function as, in the case where a pair of straight tube portions are in the oblique state, an entanglement eliminator of eliminating entanglement between the straight tube portions.

According to such configuration, it is possible to eliminate entanglement between straight tube portions being in the oblique state.

It is preferred that the first positioner74and the second positioner77include oblique portions74aand77f, respectively, the oblique portion sloping in a direction away from the hairpin tube movement region as proceeding upstream in the conveyance direction, and the first positioner74and the second positioner77are configured to recede from the hairpin portion of a hairpin tube being conveyed in the conveyance direction by the respective oblique portions74aand74fcoming into contact with the hairpin portion.

Such configuration allows the hairpin portion less likely to be interrupted by the first positioner74and the second positioner77when it passes by the first positioner74and the second positioner77.

It is preferred to further comprise a second positioner mover55for moving the second positioner77between an upper position where a straight tube portion is positioned and a lower position below the hairpin tube movement region.

According to such configuration, the second positioner77can be made to recede from the hairpin tube movement region each time an insertion operation of a hairpin tube is completed.

It is preferred to further comprise a main body frame4supporting the roller conveyor section2and the pushing section3, and a vertical mover5for moving the entirety of the main body frame4vertically.

According to such configuration, it is possible to vertically move the main body frame4supporting the roller conveyor section2and the pushing section3by the vertical mover5. This makes it possible, in the case of assembling a heat exchanger including tiers each having a row of heat exchanger tubes, to vertically move the main body frame4by the vertical mover5to thereby adjust its vertical position to correspond to each of the tiers. This makes it possible to insert a heat exchanger tube at each of the tiers.