A wire connecting method and a wire connecting apparatus

Abstract: To improve a cutting reliability and facilitate automation of connection of wires and allow for a reliable detection of wire joints. Ends of wires "a", "a'" to be connected along their longitudinal directions are linearly placed, and a tape t is wound over and around the both wire ends. At this time, if an adhesive layer of the tape is faced up, the tape is wound as the wire ends are rolled, thereby connecting the wires "a", "a'". Since the tape displays a strong resistance to a tearing force acting in its longitudinal direction, the wires are strongly connected. Particularly, if the tape contains reinforced fibers, the tape displays a stronger tear resistance. The wires "a", "a'" are rolled by being held between plates 11, 33 and moving the plate 33 to the right with respect to the plate 11. The tape t is placed on an auxiliary base plate 12 and is wound by the rolling movement of the wires "a", "a'". The plate 33 is moved back to the left after winding of the tape t to untwist the wires "a", "a'". Moreover, the invention provide a method and apparatus for detecting a wire joint thus formed.

Description: The present invention relates to a method and apparatus for connecting wires in particular at the time of exchanging (replacing) wire when terminals are mounted on wires during manufacturing of a wiring harness. For example, when terminals are mounted (by crimping, insulation displacement, etc.) on wires during manufacturing of a wiring harness, wires are drawn from a plurality of wire supplies to a cutting/mounting apparatus to be cut to a specified length and have terminals crimped into connection with (mounted on) their cut ends. At this time, one wire drawn from the wire supply is cut and an other wire is connected with its cut ends in order to replace the one wire by the other wire when the one wire is used up or the one wire needs to be replaced. Following connection methods (means) (1) to (5) have been conventionally known. Specifically, (1): to insert ends of the wires to be connected into a sleeve and compress the sleeve to connect the wire ends, (2): to place the wires on the substantially same axis such that the ends thereof substantilly face each other and to weld the wire ends to be connected as disclosed in Japanese Unexamined Patent Publication No. 8-138824, (3): to successively feed crimping pieces by a strip, position the wire ends to be connected on the crimping piece along a straight line, crimp the crimping piece while forming it into a tubular shape, and cut the crimping piece from a carrier piece, thereby connecting the wire ends by crimping, (4): to wind an aluminum tape over and around the both wire ends to connect them, and (5): to strip sheaths of the wire ends to be connected to expose strands and twist or braid the exposed strands to connect the wire ends. With the means (1), since a compression force (crimping force) of the sleeve is sometimes insufficient, reliability of connection is low (unstable). Further, the sleeve is expensive. The means (2) is expensive, and finishing of a joint portion (connection portion) is unstable, i.e. burrs and/or flash are likely to be formed. If flash or the like is formed, it may disadvantageously catch a nozzle through which the wire is fed. With the means (3), it is difficult to position and abut the wire ends against each other. If the wire ends are overlapped, burrs are likely to be formed. The burrs cause a problem of, e.g. catching the nozzle. With the means (4), the aluminum tape itself is expensive and is generally wound by hand, causing a poor operability and a low connection reliability. With the means (5), it is difficult to twist or braid the strands at the both wire ends. Since it is difficult to automate this operation, it is generally done by hand, causing a poor operability and a low connection reliability. Moreover, in the manufacturing of, for example, a wiring harness, there is a step of cutting a wire drawn from a wire supply to a specified length and mounting terminals on both ends of the cut wire by crimping, insulation displacement, etc. An example of the apparatus for mounting the terminals is a wire cutting/crimping apparatus. Under the situations described above, an object of the present invention is to provide wire connecting method and apparatus which have a high connection reliability and can be easily automated. This object is solved according to the invention by a wire connecting method according to claim 1, a wire connecting apparatus according to claim 5. Preferred embodiments of the invention are subject of the dependent claimsAccording to the invention, there is provided a wire connecting method for connecting wires by placing the wires on the substantially same axis such that ends thereof substantially face each other and winding a tape over and around the ends of the wires, comprising the steps of: placing the ends of the wires to be connected on the substantially same axis on a base plate for rolling the wires such that the wire ends substantially face each other, placing the tape in proximity of, preferably substantially in parallel to the wire ends with its adhesive surface facing towards the wires, placing a movable plate for rolling the wires on the wire ends, and moving the wire ends toward the tape to roll them onto the tape between the movable plate and the base plate to at least partly wind the tape over and around the wire ends to connect the wires. , Thus a tape is at least partly wound over and around ends of wires by substantially linearly aligning the wire ends to be connected in their longitudinal directions and rolling them. If an adhesive layer of the tape is faced up, the tape is wound over and around the wire ends as the wire ends are rolled, thereby connecting the wires. Since the piece of tape displays a strong resistance to a tearing force acting in its longitudinal direction, the wires are strongly connected. Particularly, if the tape contains reinforced fibers, it displays a stronger tear resistance. A specific embodiment of the inventive connecting method for connecting wires by placing the wires on the same axis such that ends thereof face each other and winding a tape over and around the ends of the wires, comprising the steps of: placing the ends of the wires to be connected on the same axis on a base plate for rolling the wires such that the wire ends face each other, placing the tape in parallel to the wire ends with its adhesive surface faced up, placing a movable plate for rolling the wires on the wire ends, and moving the wire ends toward the tape to roll them onto the tape between the movable plate and the base plate to wind the tape over and around the wire ends to connect the wires. Preferably, one wire drawn from one of a plurality of wire supplies is replaced by an other wire drawn from an other one of the plurality of wire supplies while being guided to a wire processing apparatus, and connecting the two wires, wherein the end of the other wire is positioned substantially on the same axis as a cut end of the one wire after the one wire is cut on the base plate, and the both wire ends are then rolled to at least partly wind the tape over and around them. Accordingly, the above method can be employed when replacing one wire drawn from one of a plurality of wire supplies by an other wire drawn from an other one of the plurality of wire supplies while being guided to a wire processing apparatus midway, and connecting the two wires. In such a case, the end of the other wire is positioned on the same axis as a cut end of the one wire after the one wire is cut on the base plate, and the both wire ends are then rolled to wind the tape over and around them. Further preferably, after being rolled in a direction to wind the tape, the both wire ends are rolled in an opposite direction to return to a path along which the wire is substantially drawn and guided. At this time, if the both wire ends are rolled in an opposite direction to return to a path along which the wire is drawn and guided after being rolled in a direction to wind the tape, the wire twisted during winding of the tape can be untwisted, enabling the wire to smoothly run thereafter. Most preferably, the wire ends are clamped and pulled in directions away from each other after the wires are connected by the tape to allow for a check whether or not the wire ends are or can be disengaged from each other, thereby judging whether or not the connection is satisfactory. Further, if the wire ends are clamped and pulled in directions away from each other after the wires are connected by the tape to check whether the wire ends are disengaged from each other, thereby judging whether or not the connection is satisfactory based on, the movement of the wire processing apparatus can be controlled in accordance with a connection judgment signal to prevent possible problems caused by a breakage of the wire and the like resulting from a defective connection. According to the invention, there is further provided a wire connecting apparatus, in particular an automated wire connecting apparatus, preferably used in connection with a wire connecting method according to the invention or an embodiment thereof, comprising: an apparatus frame provided with one or more base plates, a movable plate which is movable substantially toward and away from the base plates and capable of reciprocating with respect to wires and a tape, preferably along a direction arranged at an angle different from 0° or 180°, most preferably substantially normal to an extension direction thereof, a cutting device for cutting the one wire, a transferring plate for transferring an end of the other wire onto the same axis as a cut end of the one wire while supporting it, jigs for feeding and positioning the tape , and driving means for respectively driving the movable plate, the cutting device, the transferring plate and the parallel cutting jigs. According to a preferred embodiment of the invention, the jigs are provided for drawing the tape from a roll of tape, substantially positioning it with respect to or aligning it substantially in parallel to the ends of the wires and cutting it to a specified length. An apparatus according to a preferred embodiment of the invention used in connection with the inventive wire connecting method comprises an apparatus frame provided with base plates a movable plate which is movable toward and away from the base plates and capable of reciprocating along a direction parallel to the extension of wires and a tape, a cutting device for cutting the one wire, a transferring plate for transferring an end of the other wire onto the same axis as a cut end of the one wire while supporting it, and jigs for drawing the tape t from a roll of tape, aligning it in parallel to the ends of the wires and cutting it to a specified length, and driving means for respectively driving the movable plate, the cutting device, the transferring plate and the parallel cutting jigs. In the above construction, there may be further provided jigs for clamping the wires on a wire drawing/guiding path which jigs are provided on the apparatus frame above and below the base plate, the one jig being movable upward along the wire drawing/guiding path. Then, the above connection judgment can be made by moving the one jig after the wires are clamped by the both jigs. In other words, the connection is satisfactory if the movement of the one jig stops at such a position where the wires are just straightened, whereas it is not satisfactory if the one jig moves beyond such a position. Further preferably, the wire connecting apparatus further comprises jigs for clamping the wires on a wire drawing/guiding path which jigs are provided on the apparatus frame on substantially opposed sides of or substantially above and below the base plate, wherein the one jig is movable away from the other jig or base plate, preferably substantially along or on the wire drawing/guiding path. Preferably, the movable plate may be split into two sections for the one wire and the other wire, respectively, and the split sections of the movable plate may be (supported to be) elastically movable substantially toward and away from the wires. Then, even if diameters of the wires to be connected differ, the two split sections of the movable plate take up a diameter difference by elastically adjusting their distances to the wire ends, thereby enabling a smooth connection. These and other objects, features and advantages of the present invention will become more apparent upon a reading of the folowing detailed description and accompanying drawings in which: FIG. 1 is a schematic perspective view of one embodiment of the invention, FIGS. 2 to 4 are front views showing an action of the embodiment, FIG. 5 is a side view showing an essential portion of the embodiment, FIG. 6 is a perspective view showing how a tape is clamped according to the embodiment, FIGS. 7(a) to 7(g) are schematic front views showing the action of the embodiment, FIG. 8(a) is a schematic plan view showing the action of the embodiment, FIGS. 8(b) to 8(g) are schematic plan views showing the action of the embodiment, FIG. 9 is a diagram showing a connected state of wires, One embodiment of the invention is shown in FIGS. 1 to 8. This embodiment is scribed mainly with reference to FIG. 1. An apparatus frame F is provided with a base plate 11 used for rolling wire ends (i.e. causing the wires or wire ends to pivot or rotate around their axis or around a direction of their longitudinal extension), a movable plate 33 used for rolling wire ends, a cutting device 18 for cutting a wire a", a transferring plate 19 onto which a wire to be connected is or can be transferred, and a tape drawing device 16 for drawing a tape t". Preferably, there may be provided a forcible wire withdrawing or dropping mechanism which forcibly withdraws the portion of the wire a" which is no longer needed, i.e. the portion of the wire a" different from that portion of the wire a" to be connected to the other wire a" by means of the tape "t". Such forcible wire withdrawing mechanism may include a withdrawing roller in contact or to be brought into contact with the portion of the wire a" to be withdrawn. The base plate 11 is secured to the frame F, and an auxiliary base plate 12 is so provided at one side of the base plate 11 as to be movable toward and away from the frame F by an unillustrated air cylinder or other moving or actuating means such as a step motor. The auxiliary base plate 12 is retracted toward the frame F when the tape drawing device 16 draws the tape t while being moved forward to be substantially flush with the base plate 11 when the tape t is wound around the wire a". A roll of tape 13 is provided above the base plate 11, and the tape t is or can be guided from the tape roll 13 to a position above the auxiliary base plate 12 via guide rollers. 14a, 14b. The tape t has an adhesive layer formed on its inner surface in its rolled state, and slightly hangs down while having its adhesive layer adhered to the lower guide roller 14b. The tape t is positioned on the auxiliary base plate 12 by clamping and lowering the hanging piece of the tape t by a clamping jig 16a of the vertically movable drawing device 16. At this time, as shown in FIG. 6, one of clamping pieces 16b, 16c of the clamping jig 16a substantially facing to each other is supported via an insulating plate 16d such as a Bakelite plate, so that voltage is preferably applied to the clamping pieces 16b, 16c while providing an electrical insulation therebetween. Upon an occurrence of an error clamping of the tape t, the clamping pieces 16b, 16c are brought into contact with each other to create an electrical connection, thereby enabling detection of the error clamping. If an error clamping signal is produced, succeeding operations are not performed. After an operator resets the tape t, a tape pulling-down operation follows. The drawing device 16 is vertically moved by anunillustrated driving means provided in the guide 15. After being pulled down by a specified length, the tape t is cut by a cutting device 17 and has its cut end pressed and supported by a probe provided in the cutting device 17 (at point S in FIG. 7(d)). The tape t is released when the cutting device 17 is moved forward at a moment when the wire a" is brought to an end position of the tape t by the movable plate 33 to be described later. Simultaneously, the drawing device 16 is retracted forward. cordingly, the movement of the movable plate 33 is neither interfered nor hindered. The cutting device 17 is reciprocatingly moved preferably forward and backward preferably by an air cylinder 17a, and the drawing device 16 are caused to clamp the tape t and retract by opening and closing movements and a retracting movement (forward movement) of the clamping jig 16a at its leading end. These movements are preferably caused by anunillustrated air cylinder. The base plate 11 is preferably split into first or upper and second or lower sections, between which the cutting device 18 is provided. The cutting device 18 is actuated by an air cylinder 18a to cut the wire a" substantially vertically guided and clamps the upper part of the cut wire a". The cutting device 18 releases the wire a" at a moment when or after the wire a" is clamped between the movable plate 33 and the base plate 11, and is substantially retracted into a clearance between the upper and lower sections of the base plate 11. The movable plate 33 is preferably also split into first or upper and second or lower sections. Since being located between the upper and lower sections of the movable plate 33, the cutting device 18 neither interferes nor hinders the movement of the movable plate 33. The transferring plate 19 is transversely movable by a guide 20. A wire a'" to be connected is laterally inserted into clips 21 e.g. from the right side to be clamped and supported. The transferring plate 19 is transversely moved or moved in a direction at an angle different from 0° or 180°, preferably substantially normal with respect to the direction of extension of the wires a/a' by an unillustrated driving means provided in the guide 20. A U-shaped arm 22 is provided below the transferring plate 19, and the wire a'" is inserted into a clip 23 provided in an intermediate position of the arm 22 e.g. from the right side to be clamped. The arm 22 also drives away the lower part of the wire a'" cut by a leading end 22a of the arm 22, so that this lower part of the wire a'" does not stand as a hindrance. Guiding jigs 24, 25 each provided with a chuck are provided on the frame F at substantially opposed sides of or above and below the base plate 11, respectively. The upper guiding jig 24 moves upward while clamping the wire a" by means of the chuck upon being actuated by an air cylinder 24a. The lower guiding jig 25 clamps and fixes or positions the wire a'" upon being actuated by an air cylinder 25a. Thus, the upper and lower guiding jigs 24, 25 clamp the wires a", a'" while the upper guiding jig 24 moves upward, thereby straightening the wires "a", "a" to judge as to whether the tape t has been satisfactorily wound as described later. In other words, if the connection of the wires a", a'" is satisfactory, the upward movement of the upper guiding jig 24 stops at a specified position. If the guiding jig 24 moves further upward, a defective connection is judged to stop the operation of feeding the wires "a", "a" thereafter. An auxiliary frame 30 is provided on the front surface of the base plate 11 of the frame F such that it is pivotal preferably along forward and backward directions about its left end. A movable plate 32 is so provided on the frame 30 via a slider 32a as to be transversely movable by an air cylinder 31. At the inner side of the movable plate 32, the movable plate 33 preferably split into upper and lower sections is provided. The movable plate 33 is so supported on the movable plate 32 as to be movable toward and away from the movable plate 32, and is preferably biased in a direction away from the movable plate 32 by biasing means such as springs 34. Therefore, as shown in FIG. 5, the movable plate 33 smoothly holds the wires a", a'" in cooperation with the base plate 11 by the elastic force of the springs 34 even if the diameters of the wires a", a'" differ when the movable plate 33 is pressed into contact with the base plate 11 with the wires "a", "a'" providedtherebetween. Stoppers 35 are provided at the leading end of the frame 30. The length of the stoppers 35 is adjustable, and a contact degree (degree of proximity or distance) of the movable plate 33 with respect to the base plates 11, 12 can be adjusted by adjusting the length of the stoppers 35. This adjustment is effective in preventing abrasion of the outer surfaces of the plates 33, 11, 12. Specifically, a non-slip layer to which e.g. sand-like particles are adhered is formed on the contact surface of each of the plates 11, 12, 19 and 33 so that the wires a", a'" can be smoothly rolled. By adjusting the contact degree, the abrasion of the non-slip layers can be prevented. A piston rod 37a of an air cylinder 37 fixed to the frame F is coupled to or fixed with a hook 36 at the leading end of the frame 30 via a pin. The frame 30 is pulled toward the base plate 11 by the actuation of the air cylinder 37, thereby bringing the movable plate 33 substantially into contact (or closer to) the base plate 11 and the like with the wires "a", "a'" located therebetween. In this state, the movable plate 33 is moved to the right by actuating the air cylinder 31 to wind the tape t over and around the wires a", a'" by rolling the wires "a", "a'". Next, the action of this embodiment thus constructed is described. In the case of replacing the wire "a" by the wire "a'" from one wire supply S 2 for the exchange of the wires or other purpose in a state where, as shown in FIG. 1, the wire a" is drawn from another wire supply S 1 and guided to a wire processing apparatus (not shown) through the upper and lower guiding jigs 24, 25, the wire "a'" is clamped by the clips 21, 23 of the plate 19 and the arm 22 beforehand. If a wire exchange signal (e.g. by turning a lamp on) is inputted from the wire processing apparatus in this state, drawing of the wire a" is stopped e.g. upon pressing an unillustrated start switch, thereby proceeding to the operation of connecting the wires a", a'". The clips 21, 23 are provided with clamp completion switches. At this stage, unless these switches are on, the connecting operation is preferably not started even if the start switch is turned on. This is because a connection error is likely to occur if the wires a", a'" are insufficiently clamped by the clips 21, 23. The connection operation is performed as follows. First, in the state shown in FIGS. 2, 7(a) and 8(a), the tape drawing device 16 is moved upward to clamp the tape t by means of the clamping jig 16a (see FIGS. 7(b) and 8(b)), and draws the tape t so as to at least partly extend it substantially along the auxiliary base plate 12 (see FIGS. 7(c) and 8(c)). Simultaneously with the completion of this operation, the tape t is cut and the transferring plate 19 is moved to the right to abut against the lower base plate 11 (see FIGS. 7(c) and 8(c)). In this state, the frame 30 is moved closer to the frame F so that the movable plate 33 comes into contact with (closer to) the base plate 11 with the wires "a", "a'" locatedtherebetween (see FIGS. 7(d) and 8(d)), and the movable plate 33 is moved to the right (see FIGS. 7(e) and 8(e)). As the movable plate 33 is moved, the wires a", a'" are rolled between the base plate 11 and the movable plate 33 (preferably due to a relative movement thereof along a direction at an angle different from 0° or 180°, preferably substantially normal to the extension direction of the wire(s) a/a') and, consequently, are rolled on the tape t on the auxiliary base plate 12. By this rolling movement, the tape t is wound over and around the wires a", a'" to substantially connect or join them as shown in FIG. 9 (see FIGS. 7(e) and 8(e)). Thereafter, the movable plate 33 is moved to the left to untwist the wires a", a'" (see FIGS. 7(f) and 8(f)), and the frame 30 is moved away from the frame F to return the movable plate 33 to its initial position. As the movable plate 33 is returned, the upper and lower guiding jigs 24, 25 clamp the wires a", a'" and the upper guiding jig 24 is moved upward to judge whether or not the connection is satisfactory (see FIGS. 7(g) and 8(g)). The above operations are performed to automatically connect the wires a", a'" when the wires a", a'" are exchanged. The inventive method and apparatus thus constructed achieve a high connection reliability and easily enable automation of the wire connection. List of Reference Numerals a, a' ... wire t ... tape S 1 , S 2 ... wire supply F ... apparatus frame 11 ... base plate for rolling wires 12 ... auxiliary base plate 13 ... roll of tape 16 ... tape drawing device 16a ... tape clamping jig 17 ... tape cutting device 18 ... wire cutting device 19 ... transferring plate 24, 25 ... wire clamping/guiding jig 30 ... pivotal frame 33 ... movable plate for rolling wires 34 ... biasing spring 35 ... stopper

Claims: A wire connecting method for connecting wires (a, a') by placing the wires (a, a') on the substantially same axis such that ends thereof substantially face each other and winding a tape (t) over and around the ends of the wires (a, a'), comprising the steps of: placing the ends of the wires (a, a') to be connected on the substantially same axis on a base plate (11) for rolling the wires (a, a') such that the wire ends substantially face each other, placing the tape (t) in proximity of, preferably substantially in parallel to the wire ends with its adhesive surface facing towards the wires (a, a'), placing a movable plate (33) for rolling the wires (a, a') on the wire ends, and moving the wire ends toward the tape (t) to roll them onto the tape (t) between the movable plate (33) and the base plate (11) to at least partly wind the tape (t) over and around the wire ends to connect the wires (a, a'). A wire connecting method according to claim 1, wherein one wire (a) drawn from one (S 1 ) of a plurality of wire supplies (S 1 , S 2 ) is replaced by an other wire (a') drawn from an other one (S 2 ) of the plurality of wire supplies (S 1 , S 2 ) while being guided to a wire processing apparatus, and connecting the two wires (a, a'), wherein the end of the other wire (a') is positioned substantially on the same axis as a cut end of the one wire (a) after the one wire (a) is cut on the base plate (11), and the both wire ends are then rolled to at least partly wind the tape (t) over and around them. A wire connecting method according to claim 2, wherein, after being rolled in a direction to wind the tape (t), the both wire ends are rolled in an opposite direction to return to a path along which the wire (a; a') is substantially drawn and guided. A wire connecting method according to one or more of the preceding claims, wherein the wire ends are clamped and pulled in directions away from each other after the wires (a, a') are connected by the tape (t) to allow for a check whether or not the wire ends are or can be disengaged from each other, thereby judging whether or not the connection is satisfactory. A wire connecting apparatus preferably used in connection with a wire connecting method according to claim 2 or 3, characterised in that said wire connecting apparatus comprises: an apparatus frame (F) provided with one or more base plates (11, 12), a movable plate (33) which is movable substantially toward and away from the base plates (11, 12) and capable of reciprocating with respect to wires (a, a') and a tape (t), preferably along a direction arranged at an angle different from 0° or 180°, most preferably substantially normal to an extension direction thereof, a cutting device (18) for cutting the one wire (a), a transferring plate (19) for transferring an end of the other wire (a') onto the same axis as a cut end of the one wire (a) while supporting it, one or more jigs (16) for feeding and positioning the tape (t) , and driving means for respectively driving the movable plate (33), the cutting device (18), the transferring plate (19) and the parallel cutting jigs (17, 18). A wire connecting apparatus according to claim 5, wherein the jigs (16) are provided for drawing the tape (t) from a roll of tape (13), substantially positioning it with respect to or aligning it substantially in parallel to the ends of the wires (a, a') and cutting it to a specified length. A wire connecting apparatus according to claim 5 or 6, preferably used in connection with a wire connecting method according to claim 4, further comprising jigs (24, 25) for clamping the wires (a, a') on a wire drawing/guiding path which jigs (24, 25) are provided on the apparatus frame (F) on substantially opposed sides of or substantially above and below the base plate (11), wherein the one jig (24) is movable away from the other jig (25), preferably substantially along the wire drawing/guiding path. A wire connecting apparatus according to one or more of the preceding claims 5 to 7, wherein the movable plate (33) is split into two sections for the one wire (a) and the other wire (a'), respectively, and the split sections of the movable plate (33) are supported to be elastically (34) movable substantially toward and away from the wires (a, a').

Inventors: MATSUZAWA SUSUMU, TAKEDA TOMIYUKI, Matsuzawa, Susumu, c/o Tohoku Sumidenso Co.,Ltd, Takeda, Tomiyuki, c/o Rapias Electronics Co. Ltd.
Applicants: SUMITOMO WIRING SYSTEMS
Application year: 2000
Main classification: H01R43
IPC codes: H01R4