Heat treatment apparatus

Provided is a heat treatment apparatus capable of more reliably conveying a workpiece along a desired conveyance path by a simple configuration.A heat treatment apparatus 1 includes a heating chamber 7, a cooling chamber 8 disposed adjacent to the heating chamber 7, a conveyance tray 2 to support the workpiece 100, and a first conveyance mechanism 3 to convey the conveyance tray 2 along a conveyance path B1 from the outside of the heating chamber 7 to the outside of the cooling chamber 8 through the heating chamber 7 and the cooling chamber 8.

TECHNICAL FIELD

The present invention relates to a heat treatment apparatus for applying heat treatment and cooling treatment to a workpiece.

BACKGROUND ART

For example, a heat treatment apparatus for applying heat treatment to a metallic component (workpiece) such as a gear is known (for example, refer to Patent Application Documents 1 and 2). A continuous vacuum carburizing furnace as a heat treatment apparatus described in Patent Application Document 1 includes a plurality of treatment chambers. A metallic component is conveyed among the plurality of treatment chambers by a conveyance portion.

CITATION LIST

Patent Application Documents

Patent Application Document 1: Japanese Unexamined Patent Application Publication No. 2014-231637

Patent Application Document 2: Japanese Unexamined Patent Application Publication No. 2014-70251

SUMMARY OF THE INVENTION

Technical Problem

The conveyance portion includes a plurality of horizontal conveyance portions, and conveys the metallic component by directly delivering the metallic component between adjacent horizontal conveyance portions. However, in such a configuration, when the metallic component is delivered between adjacent horizontal conveyance portions, unless accuracy of displacement of the metallic component is high, the metallic component cannot be disposed at a desired position in the horizontal conveyance portion that receives the metallic component. As a result, the metallic component may lose its balance and fall from the horizontal conveyance portion. In particular, when the metallic component is a small component, this trouble easily occurs.

In view of the circumstances described above, an object of the present invention is to provide a heat treatment apparatus capable of more reliably conveying a workpiece along a desired conveyance path by a simple configuration.

Solution to Problem

(1) In order to solve the problem described above, a heat treatment apparatus according to an aspect of the present invention includes a heating chamber to provide heat energy to a workpiece, a cooling chamber disposed adjacent to the heating chamber to cool the workpiece provided with the heat energy, a conveyance tray to support the workpiece, and a first conveyance mechanism to convey the conveyance tray along a predetermined conveyance path from the outside of the heating chamber to the outside of the cooling chamber through the heating chamber and the cooling chamber.

With this configuration, a workpiece is supported by the conveyance tray, and this conveyance tray is conveyed in the conveyance path by the first conveyance mechanism. Accordingly, the first conveyance mechanism conveys the workpiece not directly but via the conveyance tray. Therefore, the first conveyance mechanism can convey the conveyance tray in a stable posture without being influenced by the shape of the workpiece. As a result, the workpiece is conveyed in a more stable posture. In addition, by a simple configuration using the conveyance tray to convey the workpiece, the workpiece is conveyed in a stable posture. Accordingly, by the simple configuration, a heat treatment apparatus capable of more reliably conveying a workpiece along a desired conveyance path is realized.

(2) Preferably, the heat treatment apparatus further includes a heating member to heat the workpiece, disposed away from the conveyance path along a direction crossing a conveyance direction of the workpiece in the heating chamber, and a second conveyance mechanism to move the workpiece between the conveyance tray and the heating member in the heating chamber.

With this configuration, a workpiece can be heated by the heating member. At the time of this heating, the workpiece is away from the conveyance tray. Therefore, the conveyance tray is prevented from being heated by the heating member and the workpiece. Accordingly, defects of the conveyance tray caused by heat distortion etc. can be prevented more reliably. Therefore, the life of the conveyance tray (the number of times of reuse of the conveyance tray) can be improved. Further, since a conveyance tray that does not need to be heated can be prevented from being heated, through improvement in energy efficiency, the energy for the heat treatment apparatus can be further saved.

(3) More preferably, the conveyance direction extends along a horizontal direction, and the heating member is disposed above the conveyance path.

With this configuration, by disposing the heating member at a position away from the conveyance direction, the heat treatment apparatus can be prevented from assuming a shape long in the conveyance direction. In addition, since the heating member is disposed above the conveyance path, heat from the heating member is transferred to an upper side of the heating member, and is prevented from being transferred to the conveyance path side. Accordingly, the conveyance tray can be more reliably prevented from being heated.

(4) More preferably, the second conveyance mechanism includes a support portion to lift the workpiece through a hole portion formed in the conveyance tray in the heating chamber.

With this configuration, the support portion can lift the workpiece by a simple operation of upward displacement with respect to the conveyance tray. Therefore, the configuration of the second conveyance mechanism can be made simpler.

(5) Preferably, the heat treatment apparatus includes a coolant passage to supply a coolant to the workpiece inside the cooling chamber, and the coolant passage extends along a vertical direction.

With this configuration, the cooling chamber can be formed to be vertically long, so that the size of the heat treatment apparatus in the horizontal direction can be reduced. In addition, an extending direction of the coolant passage and the conveyance direction are orthogonal to each other, so that the heat treatment apparatus can be prevented from being shaped to be excessively large in size in each of the horizontal direction and the vertical direction. Therefore, the heat treatment apparatus can be made more compact.

(6) Preferably, the heat treatment apparatus further includes an intermediate door provided in the conveyance path to be switchable between a closed state and an opened state between the heating chamber and the cooling chamber, and the first conveyance mechanism includes a heating chamber-side conveyance portion disposed in the heating chamber to convey the conveyance tray along the conveyance path, and a cooling chamber-side conveyance portion disposed away from the heating chamber-side conveyance portion and disposed in the cooling chamber to convey the conveyance tray along the conveyance path.

With this configuration, a space between the heating chamber and the cooling chamber can be closed by the intermediate door. Accordingly, the atmosphere in the heating chamber can be made more stable. In addition, a coolant inside the cooling chamber can be more reliably prevented from flying into the heating chamber.

(7) Preferably, the first conveyance mechanism is configured to circulate the conveyance tray between the outside of the heating chamber, the heating chamber, the cooling chamber, and the outside of the cooling chamber.

With this configuration, the conveyance tray can be repeatedly used for conveyance of workpieces in the heat treatment apparatus. Therefore, the number of conveyance trays necessary for heat treatment of a large number of workpieces in the heat treatment apparatus can be further reduced. The possible number of times of repeated use of the conveyance tray is significantly increased by preventing the conveyance tray from being heated.

(8) Preferably, the first conveyance mechanism includes a drive source disposed outside the heating chamber, an output transmitting member to transmit an output of the drive source from the outside of the heating chamber to the inside of the heating chamber at a predetermined fixed position, and a drive member disposed inside the heating chamber to displace the conveyance tray in a predetermined conveyance direction by receiving power from the output transmitting member.

With this configuration, since the drive source is disposed outside the heating chamber, the heating chamber can be made more compact. In addition, the output transmitting member is configured so as not to move from a fixed position. Therefore, a portion that needs to be sealed between the inside and the outside of the heating chamber, that is, a portion between the output transmitting member and the heating chamber can be made smaller. Accordingly, the first conveyance mechanism can be realized by a simple configuration.

Effect of the Invention

According to the present invention, a heat treatment apparatus capable of more reliably conveying a workpiece along a desired conveyance path can be realized by a simple configuration.

EMBODIMENTS OF THE INVENTION

Hereinafter, an embodiment to carry out the present invention is described with reference to the drawings. The present invention can be widely applied as a heat treatment apparatus for applying heat treatment to a workpiece.

FIG. 1is a schematic and conceptual perspective view of a heat treatment apparatus1, partially cut away.FIG. 2is a front view of a heating device4of the heat treatment apparatus1.FIG. 3is an inlet-side side view of the heating device4.FIG. 4is an outlet-side side view of the heating device4.FIG. 5is a back view of the heating device4.FIG. 6is a partial sectional view of a major portion of the heating device4, viewed from the front side.FIG. 7is a sectional view in a state where the major portion of the heating device4is shown in a plan view.FIG. 8is a side view of an outlet side of an intermediate door unit5of the heat treatment apparatus1.

FIG. 9is a front view of a cooling device6of the heat treatment apparatus1.FIG. 10is aside view of an outlet side of the cooling device6.FIG. 11is a back view of the cooling device6.FIG. 12is a sectional view taken along line XII-XII inFIG. 11, showing a section orthogonal to a conveyance direction A1of a workpiece100.FIG. 13is an enlarged view of a major portion ofFIG. 12.FIG. 14is a sectional view taken along line XIV-XIV inFIG. 10, showing the cooling device6viewed from the front side.FIG. 15andFIG. 16are views to describe a cooling treatment operation in the cooling device6.

Hereinafter, based on a state where the heat treatment apparatus1is viewed from the front, the left-right direction X1(conveyance direction A1), the front-rear direction Y1, and the up-down direction Z1are prescribed.

Referring toFIG. 1andFIG. 2, the heat treatment apparatus1is provided for applying heat treatment to the workpiece100. This heat treatment includes heat applying treatment and cooling treatment. Examples of heat applying treatment include carburizing heat treatment and heat equalizing treatment, etc. Examples of cooling treatment include quenching treatment, etc. Detailed examples of heat applying treatment and cooling treatment to be performed in the heat treatment apparatus1are not particularly limited. In the present embodiment, the workpiece100is a metallic component, for example, a gear.

The heat treatment apparatus1includes a conveyance tray2, a first conveyance mechanism3, a heating device4, an intermediate door unit5, and a cooling device6.

The conveyance tray2is a conveyance support member to support the workpiece100. The conveyance tray2is, in the present embodiment, a member made of metal or carbon, and is repeatedly used in heat treatment of the workpiece100in the heat treatment apparatus1. The conveyance tray2conveys the workpiece100along a predetermined conveyance direction A1extending along the horizontal direction. In the present embodiment, when heat applying treatment is applied to the workpiece100in the heating device4, the conveyance tray2is away from the workpiece100so as to be prevented from being exposed to high heat from the heating device4.

The conveyance tray2includes a frame portion2aand support portions2b.

The frame portion2ais provided as a portion to be supported by the first conveyance mechanism3. The frame portion2ais formed into, for example, a plate shape having a rectangular external form and a predetermined thickness. The frame portion2ais formed to have a size that can be housed inside the heating device4and housed inside the cooling device6. At a central portion of the frame portion2a, a hole portion2c(opening) is formed. This hole portion2cis formed to be, for example, circular, and penetrates through the frame portion2ain a thickness direction of the frame portion2a. This hole portion2cis provided to move up and down the workpiece100in the heating device4, and provided to allow a coolant to pass through in the cooling device6.

For example, from an inner circumferential portion of the hole portion2ctoward a center of the hole portion2c, a plurality of support portions2bextend. The support portions2bare provided as portions to support the work piece100. The support portions2bare provided in plural (in the present embodiment, three) at even intervals in the circumferential direction of the hole portion2c. Each support portion2bextends from the rim of the hole portion2ctoward the central portion of the hole portion2c. Tip ends of these support portions2bare away from each other so as not to block an operation of lifting the workpiece100by a second conveyance mechanism18described below.

On each support portion2b, a positioning projection2dto position (center) the workpiece100is provided. The projections2dare disposed to receive an outer circumferential surface of the workpiece100, and extend upward. The workpiece100is preferably placed on the support portions2bby point contact or linear contact. The support portions2bfunction as rectifying members to rectify a coolant in a coolant passage48as described below. Batch treatment can be performed by stacking a plurality of workpieces100on the conveyance tray2.

The conveyance tray2configured as described above is conveyed along the conveyance direction A1to the heating device4and the cooling device6by the first conveyance mechanism3. The first conveyance mechanism3is provided to convey the conveyance tray2along a predetermined conveyance path B1from the outside of the heating device4to the outside of a cooling chamber8through a heating chamber7of the heating device4and the cooling chamber8of the cooling device6. This first conveyance mechanism3is configured to circulate the conveyance tray2along the conveyance path B1to the outside of the heating device4, the inside of the heating chamber7of the heating device4, the inside of the cooling chamber8of the cooling device6, and the outside of the cooling chamber8.

Referring toFIG. 1toFIG. 7, the first conveyance mechanism3includes a heating chamber-side conveyance portion11disposed in the heating chamber7to convey the conveyance tray2along the conveyance path B1, a cooling chamber-side conveyance portion12disposed in the cooling chamber8at a position away from the heating chamber-side conveyance portion11to convey the conveyance tray2along the conveyance path B1, and an intermediate conveyance portion13disposed between the heating chamber-side conveyance portion11and the cooling chamber-side conveyance portion12.

The heating chamber-side conveyance portion11is provided to convey the conveyance tray2inside the heating chamber7. The cooling chamber-side conveyance portion12is provided to convey the conveyance tray2, that passed through the heating chamber7, inside the cooling chamber8. The intermediate conveyance portion13is provided to dispose the conveyance tray2along the conveyance direction A1in an intermediate door unit5. Details of the first conveyance mechanism3are described below.

The heating device4includes the heating chamber7, a bottom portion14, columnar supports15, an inlet door unit16, a heating member17, and a second conveyance mechanism18.

The bottom portion14is provided as a base member of the heating device4. The bottom portion14is formed to be rectangular in a plan view, and from the bottom portion14, a plurality of columnar supports15extend upward. The columnar supports15support the heating chamber7.

The heating chamber7is provided to provide heat energy to the workpiece100. The heating chamber7is formed into a rectangular parallelepiped box shape. For example, the heating chamber7is configured for applying, in a state vacuated by a vacuum pump not shown in the drawings, heat treatment to the workpiece100. The heating chamber7has an inlet wall7a, an outlet wall7b, a front wall7c, a rear wall7d, a top wall7e, and a bottom wall7f.

In the inlet wall7a, an inlet7g(opening) to introduce the workpiece100into the heating chamber7is formed. The inlet7gis disposed close to a lower portion of the inlet wall7a, extends to be long and narrow from the front wall7cside to the rear wall7dside, and allows the workpiece100to pass through. This inlet7gis opened and closed by the inlet door unit16.

The inlet door unit16includes an inlet door19and an inlet door opening and closing mechanism20.

The inlet door19is a plate-shaped member disposed along an outer surface of the inlet wall7a. The inlet door19closes the inlet7gwhen being disposed at a closed position. In addition, the inlet door19opens the inlet7gwhen being disposed at an open position. The inlet door19is provided with a sealing structure made of NBR (natural rubber), fluorine-containing rubber, etc., and configured to seal an atmosphere gas and a coolant in the heat treatment apparatus1. The inlet door19is operated to open and close by the inlet door opening and closing mechanism20.

The inlet door opening and closing mechanism20is formed, in the present embodiment, by using a fluid pressure cylinder, and includes a cylinder supported by the bottom portion14and a rod projecting from the cylinder and joined to the inlet door19. According to a change in projecting amount of the rod from the cylinder, the inlet door19opens or closes. The inlet door19is sandwiched by a pair of front and rear guides21provided on an outer surface of the inlet wall7aand extending vertically, and displacement of the inlet door19in the up-down direction Z1is guided. In a state where the inlet door19is opened, the workpiece100that passed through the inlet7gof the heating chamber7is conveyed to the inside of the heating chamber7by the heating chamber-side conveyance portion11.

The heating chamber-side conveyance portion11is disposed inside the heating chamber7. This heating chamber-side conveyance portion11is a belt conveyor type conveyance portion.

The heating chamber-side conveyance portion11includes a heating chamber-side motor22as a drive source disposed outside the heating chamber7, an output transmitting member23that transmits an output of the heating chamber-side motor22from the outside of the heating chamber7to the inside of the heating chamber7at a predetermined fixed position, a drive shaft25and a driven shaft26to be rotated by the output transmitting member23, and a pair of chains27(drive members) that are disposed inside the heating chamber7and displace the conveyance tray2in the conveyance direction A1by receiving power from the output transmitting member23.

The heating chamber-side motor22is, for example, an electric motor. The heating chamber-side motor22is disposed on a downstream side in the conveyance direction A1in the heating chamber7at the rear (outer surface side) of the rear wall7dof the heating chamber7. A housing22aof the heating chamber-side motor22is fixed to the rear wall7dby using a fixing member such as a bolt. Between the housing22aand the rear wall7d, a sealing member (not shown) is disposed, and the sealing member seals airtightly a portion between the housing22aand the rear wall7d.

To an output shaft (not shown) of the heating chamber-side motor22, one end portion of the output transmitting member23is joined rotatably in a coordinated manner. In detail, the output shaft of the heating chamber-side motor22is directed upward in the up-down direction Z1, and the output transmitting member23is directed in the front-rear direction Y1(horizontal direction). These output shaft and output transmitting member23are joined rotatably in a coordinated manner via a mechanism of a gear pair with intersecting axes such as a bevel gear pair.

The output transmitting member23extends inside the heating chamber7through a hole portion7iformed in the rear wall7d, at a fixed position close to a lower portion of the heating chamber7. To the other end portion of the output transmitting member23, a sprocket is joined integrally rotatable. The drive shaft25is disposed adjacent to the output transmitting member23. The drive shaft25is disposed on a downstream side of the heating chamber7in the conveyance direction A1. The drive shaft25extends along the front-rear direction orthogonal to the conveyance direction A1. To one end portion of the drive shaft25, a sprocket is joined rotatably together. Around the sprocket of the output transmitting member23and the sprocket of the drive shaft25, a chain29is wound. According to the configuration described above, an output of the heating chamber-side motor22is transmitted to the drive shaft25.

The driven shaft26is disposed parallel to the drive shaft25. The driven shaft26is disposed near the inlet7gof the heating chamber7. The drive shaft25and the driven shaft26are respectively supported rotatably by the bottom wall7fvia support members28and28including bearings, etc. To a pair of end portions of the drive shaft25in the front-rear direction Y1and a pair of end portions of the driven shaft26in the front-rear direction Y1, sprockets are respectively joined rotatably together. Around these pairs of sprockets arranged side by side in the conveyance direction A1, chains27and27are wound. The pair of chains27and27are disposed away from each other in the front-rear direction Y1, and are configured to enable the frame portion2aof the conveyance tray2to be placed on the pair of chains27and27.

In the present embodiment, in the front-rear direction Y1, a distance between the chains27and27is set to be equal to or longer than an entire length of the workpiece100. With the configuration described above, according to driving of the heating chamber-side motor22, the output transmitting member23rotates, and this rotation is transmitted to one drive shaft25. Then, this drive shaft25drives the chains27and27and rotates the driven shaft26. That is, according to driving of the heating chamber-side motor22, the pair of chains27and27rotate. Accordingly, the conveyance tray2on the pair of chains27and27are conveyed in the conveyance direction A1.

At an intermediate portion of the heating chamber7in the conveyance direction A1, the heating member17is disposed, and further, at a lower end portion of the heating chamber7and below the heating chamber7, the second conveyance mechanism18is disposed. That is, the second conveyance mechanism18is disposed below the first conveyance mechanism3(horizontal conveyance mechanism). As described below, a part of the coolant passage48of the cooling device6is disposed at a height position lower than a height position of the heating chamber7. Accordingly, the heat treatment apparatus1can be made more compact.

The heating member17is a member disposed away from the conveyance path B1along a direction (up-down direction Z1) crossing the conveyance direction A1in the heating chamber7to heat the workpiece100. The heating member17is disposed, in the present embodiment, above the conveyance path B1. The heating member17is, in the present embodiment, an induction heating coil, and is configured to heat the workpiece100by induction heating.

The heating member17is configured by forming a conductive member such as copper in a spiral manner. A spiral portion of the heating member17is formed into a size capable of surrounding the workpiece100. One end portion and the other end portion of the heating member17extend linearly rearward, and are supported by the rear wall7d. One end portion and the other end portion of the heating member17are electrically connected to a power source (not shown), and is supplied with electric power from this power source. Below the heating member17, the second conveyance mechanism18is disposed.

The second conveyance mechanism18is provided to move up and down the workpiece100between the conveyance tray2and the heating member17in the heating chamber7.

The second conveyance mechanism18includes a support portion18ato support the workpiece100, and a support portion drive mechanism30to displace this support portion18abetween the conveyance tray2and the heating member17.

The support portion18aof the second conveyance mechanism18is provided to lift the workpiece100through the hole portion2cformed in the conveyance tray2, in the heating chamber7. The support portion18ais configured to move up and down between a predetermined standby position P1and a heating position P2. The support portion18ais formed by using a material with excellent heat resistance such as carbon, metal, or ceramic. The support portion18aat the standby position P1is disposed between the pair of chains27and27of the heating chamber-side conveyance portion11. In the present embodiment, the support portion18ais disposed at a substantially center of the heating chamber7in the conveyance direction A1.

The support portion18ais shaped to become capable of lifting the workpiece100supported by the conveyance tray2, without contact with the conveyance tray2. In detail, the support portion18aincludes a shaft-shaped support portion main body18b, and support portion arms18cextending radially from the support portion main body18b. The support portion main body18bat a standby position P1is disposed near the bottom wall7fof the heating chamber7.

The support portion arms18care disposed, for example, at even intervals in the circumferential direction of the support portion main body18bso that the support portion arms18cand the support portions2bof the conveyance tray2that has reached a position above the standby position P1are alternately arranged in the circumferential direction of the support portion main body18b. At the center of the hole portion2cof the conveyance tray2, the components of the conveyance tray2are not disposed, and this configuration prevents the support portion main body18bfrom coming into contact with the conveyance tray2. The support portion main body18bis joined to the support portion drive mechanism30.

The support portion drive mechanism30is provided to displace the support portion18abetween the standby position P1and the heating position P2. In the present embodiment, the support portion drive mechanism30is formed by using a screw mechanism. Examples of this screw mechanism include a so-called bearing nut mechanism configured by using a bearing as a nut on an outer circumference of a male threaded shaft, and a ball screw mechanism, etc.

Further, the support portion drive mechanism30includes a rotation mechanism to rotate the support portion18aaround a central axis of the support portion18a. Note that, the detailed configuration of the support portion drive mechanism30is not limited as long as it can displace the support portion18ain the up-down direction Z1, can hold the support portion18aat the standby position P1and the heating position P2, and can rotate the support portion18a(workpiece100) at the heating position P2.

The support portion drive mechanism30includes a main body portion30a, a movable portion30b, and a drive source30c.

The main body portion30ais disposed in a space below the heating chamber7, and supported by the bottom portion14. The main body portion30ais disposed adjacent to a drive source30csuch as an electric motor. The drive source30cis supported by the bottom portion14. The main body portion30adisplaces the movable portion30bin the up-down direction Z1by receiving an output from the drive source30c. The movable portion30bis supported by the main body portion30a, and extends upward from the main body portion30a. The movable portion30bis disposed to penetrate through a cylinder portion31fixed to the bottom wall7fof the heating chamber7and penetrate through the bottom wall7f. A bottom portion of the cylinder portion31is disposed to surround the movable portion30b.

With the configuration of the support portion drive mechanism30described above, after the conveyance tray2and the workpiece100are conveyed to a position above the standby position P1(below the heating member17) by the heating chamber-side conveyance portion11of the first conveyance mechanism3, the movable portion30bof the support portion drive mechanism30moves upward. According to this movement, the support portion18amoves upward from the standby position P1, lifts the workpiece100, and further moves to the heating position P2. Then, by induction heating by the heating member17, the workpiece100is heated to a predetermined carburization temperature.

At this carburizing, the movable portion30brotates the support portion18aand the workpiece100around the central axis of the support portion18aso that the workpiece100can be more uniformly inductively heated. When the operation of heating the workpiece100is completed, the movable portion30bimmobilizes the support portion18aand the workpiece100at a predetermined rotation position (a position around the central axis of the support portion18a). Positional control in this case is performed by a sensor and a control device that are not shown.

After the immobilizing, the movable portion30bof the support portion drive mechanism30is moved downward, and accordingly, the support portion18aand the workpiece100move downward from the heating position P2. Then, the workpiece100is placed on the support portions2bof the conveyance tray2. After that, the support portion18ais further displaced downward to the standby position P1. For example, by a detection portion installed on the conveyance tray2and a sensor that detects a state of this detection portion, positional control of the support portion18ain the up-down direction Z1is performed. Accordingly, without heating the conveyance tray2by the heating member17, heat treatment can be applied to the workpiece100.

The conveyance tray2and the workpiece100after being subjected to heat treatment are conveyed to the intermediate door unit5side by the heating chamber-side conveyance portion11.

The intermediate door unit5is configured to be capable of closing to seal airtightly and liquid-tightly between the outlet7hformed in the outlet wall7bof the heating chamber7and the inlet8gformed in an inlet wall8aof the cooling chamber8, and to be capable of making these outlet7hand inlet8gopen.

Referring toFIG. 6toFIG. 8, the intermediate door unit5includes a frame portion5a, an intermediate door33, and an intermediate door opening and closing mechanism34.

The frame portion5ais a portion assuming a substantially rectangular frame shape as a whole disposed between the heating device4and the cooling device6, and extends along the conveyance direction A1. The frame portion5ais fixed to the outlet wall7bof the heating chamber7, and fixed to the inlet wall8aof the cooling chamber8.

The outlet wall7bof the heating chamber7is provided as a wall portion dividing the heating chamber7and the cooling chamber8. The outlet wall7bof the heating chamber7is formed into, for example, a rectangular plate shape. At a portion closer to a lower portion of the outlet wall7bof the heating chamber7, the outlet7his formed. This outlet7his provided as a rectangular opening, and communicates with both of the space inside the heating chamber7and the space inside the cooling chamber8. This outlet7his opened and closed by the intermediate door33.

The intermediate door33is a plate-shaped member disposed along a side surface on the cooling chamber8side of the outlet wall7b. The intermediate door33closes the outlet7hof the outlet wall7bby being disposed at a closed position. In addition, the intermediate door33opens the outlet7hof the outlet wall7bby being disposed at an open position. Accordingly, the intermediate door33is provided in the conveyance path so as to be switchable between a closed state and an opened state between the heating chamber7and the cooling chamber8. The intermediate door33is provided with a sealing structure including NBR (nitrile rubber) and fluorine-containing rubber, etc., which is a configuration enabled to seal an atmosphere gas and a coolant between the heating chamber7and the cooling chamber8. The intermediate door33is operated to open and close by the intermediate door opening and closing mechanism34.

In the present embodiment, the intermediate door opening and closing mechanism34is formed by using a fluid pressure cylinder, and includes a cylinder34asupported by an upper portion of the frame portion5a, and a rod34bprojecting from the cylinder34aand joined to the intermediate door33. According to a change in projecting amount of the rod34bfrom the cylinder34a, the intermediate door33opens and closes. The intermediate door33is sandwiched by a pair of front and rear guides35provided on one side surface of the cooling chamber8side of the outlet wall7band extending vertically, and displacement of the intermediate door33in the up-down direction Z1is guided by the guides35. In a state where the intermediate door33is opened, the workpiece100that passed through the heating chamber7is conveyed to the inside of the cooling chamber8by the intermediate conveyance portion13.

The intermediate conveyance portion13is supported by a lower portion of the frame portion5aof the intermediate door unit5, and disposed inside the cooling chamber8. This intermediate conveyance portion13is, for example, a belt conveyor type conveyance portion.

The intermediate conveyance portion13includes a drive shaft36, a driven shaft37disposed on an upstream side of the drive shaft36in the conveyance direction A1, and a pair of chains38and38(drive members) that displace the conveyance tray2in the conveyance direction A1by receiving power from the drive shaft36.

The driven shaft37and the drive shaft36extend along the front-rear direction orthogonal to the conveyance direction A1. The drive shaft36and the driven shaft37are respectively supported rotatably by the bottom portion of the frame portion5avia a support member having a bearing, etc. To a pair of end portions of the drive shaft36in the front-rear direction Y1and a pair of end portions of the driven shaft37in the front-rear direction, sprockets are respectively joined rotatably together. Around these pairs of sprockets arranged in the conveyance direction A1, chains38and38are wound. The chains38and38are disposed away from each other in the front-rear direction Y1, which are a configuration enabled to allow the frame portion2aof the conveyance tray2to be placed on the chains38. The drive shaft36is joined to a drive shaft63described below (refer toFIG. 12) via a chain44, and is driven to rotate in accordance with rotation of the drive shaft63.

The workpiece100conveyed to the inside of the cooling chamber8by the intermediate conveyance portion13configured as described above is subjected to cooling treatment by the cooling device6.

Referring toFIG. 1andFIG. 9toFIG. 14, the cooling device6includes the cooling chamber8, an outlet door unit41, a coolant passage defining body42, and a vertical displacement mechanism43.

The cooling chamber8is disposed adjacent to the heating chamber7to cool the workpiece100provided with heat energy in the heating chamber7. The cooling chamber8is formed into a substantially rectangular parallelepiped box shape vertically long. The cooling chamber8includes the inlet wall8a, an outlet wall8b, a front wall8c, a rear wall8d, a top wall8e, and a bottom wall8f.

The inlet wall8ais a wall portion disposed to face the intermediate door33and extending vertically. In an upper portion of the inlet wall8a, the inlet8gis formed, and to this inlet8g, the frame portion5aof the intermediate door unit5is fixed. According to the configuration described above, the workpiece100that passed through the frame portion5aof the intermediate door unit5is allowed to advance toward a downstream side of the cooling chamber8in the conveyance direction A1.

In the outlet wall8b, an outlet8hto carry the workpiece100out of the cooling chamber8is formed. The outlet8his disposed close to an intermediate portion of the outlet wall8bin the up-down direction Z1, extends long and narrow from the front wall8cside to the rear wall8dside, and allows the workpiece100to pass through. This outlet8his opened and closed by the outlet door unit41.

The outlet door unit41includes an outlet door45and an outlet door opening and closing mechanism46.

The outlet door45is a plate-shaped member disposed along an outer surface of the outlet wall8b. The outlet door45closes the outlet8hby being disposed at a closed position. In addition, the outlet door45opens the outlet8hby being disposed at an open position. The outlet door45is provided with a sealing structure including NBR, fluorine-containing rubber, etc., which is a configuration enabled to seal an atmosphere gas and a coolant inside the cooling chamber8. The outlet door45is operated to open and close by the outlet door opening and closing mechanism46.

In the present embodiment, the outlet door opening and closing mechanism46is formed by using a fluid pressure cylinder, and includes a cylinder46asupported by the cooling chamber8on an outer surface of the outlet wall8b, and a rod46bprojecting from the cylinder46aand joined to the outlet door45. According to a change in projecting amount of the rod46bfrom the cylinder46a, the outlet door45opens and closes. The outlet door45is sandwiched by a pair of front and rear guides47provided on the outer surface of the outlet wall8band extending vertically, and displacement of the outlet door45in the up-down direction is guided. In a state where the outlet door45is opened, the workpiece100that passed through the outlet8hof the cooling chamber8is conveyed to the outside of the cooling chamber8.

From the conveyance tray2that passed through the outlet8h, the workpiece100is taken out. The conveyance tray2from which the workpiece100was taken out is conveyed to the inlet7gside of the heating chamber7of the heating device4by a returning mechanism such as a belt conveyor, not shown in the drawings, provided to the first conveyance mechanism3. According to the configuration of the first conveyance mechanism3, the conveyance tray2is conveyed to circulate to the heating device4and the cooling device6.

Inside the cooling chamber8, the coolant passage defining body42is provided. The coolant passage defining body42is a unit to define a coolant passage48which supplies a predetermined coolant to the workpiece100that passes through the conveyance path B1along the conveyance direction A1. In the present embodiment, cooling water is used as a coolant, however, oil or the like can be used instead of the cooling water.

The coolant passage defining body42includes a lower member49and an upper member50as a plurality of coolant passage defining members, an introduction pipe51, and the conveyance tray2. The conveyance tray2is disposed between the lower member49and the upper member50as the plurality of coolant passage defining members. That is, in the present embodiment, the conveyance tray2has both of a function of conveying the workpiece100and a function of defining a portion of the coolant passage48. Also the conveyance tray2cooperates with the lower member49and the upper member50, which is configured to define the coolant passage48.

In the present embodiment, the lower member49, the conveyance tray2, and the upper member50are configured to define the coolant passage48in a state of housing the workpiece100by being displaced to approach each other along the up-down direction Z1(crossing direction) crossing the conveyance direction A1, and to allow the workpiece100to be let into and out of the coolant passage48along the conveyance direction A1by being displaced to separate from each other along the up-down direction Z1. The coolant passage48is provided to supply the coolant to the workpiece100inside the cooling chamber8, and extends along the up-down direction Z1(vertical direction).

The lower member49is provided as a cylindrical pipe extending upward from the bottom wall8fof the cooling chamber8. The lower member49is disposed at a substantially center of the cooling chamber8in a plan view. An upper end portion of the lower member49is disposed near the cooling chamber-side conveyance portion12, and is configured to be positioned below the conveyance tray2. To the lower member49, the introduction pipe51is connected.

The introduction pipe51is provided to introduce the coolant from the outside of the cooling chamber8to the lower member49. The introduction pipe51extends in the front-rear direction Y1. One end of the lower member49is connected to a lower end portion of the rear wall8d. The lower member49penetrates through the rear wall8dof the cooling chamber8, and the other end of the lower member49is connected to a coolant tank not shown in the drawings. According to the configuration described above, the coolant pressure-fed from the coolant tank to the introduction pipe51by a pump (not shown) is introduced to the inside of the lower member49, and injected upward. A discharge pipe52is provided adjacent to the introduction pipe51.

The discharge pipe52is provided to discharge the coolant discharged from the inside to the outside of the coolant passage48in the cooling chamber8, to the outside of the cooling chamber8. The discharge pipe52is formed at a lower end portion of the rear wall8dof the cooling chamber8at a position adjacent to the introduction pipe51, and continued to the inside and the outside of the cooling chamber8. The discharge pipe52is connected to the coolant tank not shown in the drawings, and a coolant is stored in this coolant tank. Above the lower member49adjacent to the discharge pipe52, the upper member50is disposed.

The upper member50is provided as a member supported to float inside the cooling chamber8. The upper member50is provided as a cylindrical pipe extending in the up-down direction Z1. At a lower end portion of the upper member50, a flange portion50ais provided. This upper member50is supported to be displaceable in the up-down direction Z1by the vertical displacement mechanism43.

The vertical displacement mechanism.43is provided to support the upper member50and a portion (chain unit66described below) of the cooling chamber-side conveyance portion12in a displaceable manner in the up-down direction Z1with respect to the lower member49. The vertical displacement mechanism43is configured to enable the upper member50and the chain unit66to move relative to each other in the up-down direction Z1. The vertical displacement mechanism43is configured to displace the upper member50downward to bring the upper member50into contact with the conveyance tray2when the conveyance tray2is disposed at a cooling position P4. The vertical displacement mechanism43is supported by the top wall8eof the cooling chamber8, and is disposed to extend downward from the top wall8e.

The vertical displacement mechanism43includes a base plate55, suspended stays56and56, a moving up/down mechanism57, and guide shafts58and58.

The base plate55is formed by using, in the present embodiment, a metal plate. This base plate55is disposed at a predetermined distance in the up-down direction Z1from the opening at the upper end of the upper member50. Accordingly, the coolant that was injected upward inside the upper member50can be prevented from being bounced by the base plate55and returned to the inside of the coolant passage48. To an outer circumferential edge of an upper end of the base plate55, the suspended stays56and56are fixed.

The suspended stays56and56are formed by using, in the present embodiment, metal plates. The suspended stays56and56are disposed, for example, away from each other in the front-rear direction Y1. Upper end portions of the respective suspended stays56and56are fixed to the base plate55. Lower end portions of the respective suspended stays56and56are fixed to an upper end portion of the upper member50. Accordingly, the upper member50, the suspended stays56and56, and the base plate55are configured to integrally move as a unit. The unit of these is displaced in the up-down direction Z1by the moving up/down mechanism57.

In the present embodiment, the moving up/down mechanism57is formed by using a fluid pressure cylinder, and includes a cylinder57asupported by the top wall8eof the cooling chamber8, and a rod57bprojecting downward from the cylinder57aand joined to a center of the base plate55. The cylinder57ais disposed outside the cooling chamber8, and the rod57bextends from a hole portion formed in the top wall8eto the inside of the cooling chamber8.

According to a change in projecting amount of the rod57bfrom the cylinder57a, the upper member50, etc., are displaced in the up-down direction Z1. For example, two guide shafts58are provided, fixed to the base plate55, and supported slidably in the up-down direction Z1by guide shaft guide portions59formed on the top wall8e. This realizes smoother displacement of the rod57b.

Further, it is configured that the conveyance tray2is conveyed from the intermediate conveyance portion13to a predetermined conveyance position P3by the cooling chamber-side conveyance portion12.

Referring toFIG. 12toFIG. 14, the cooling chamber-side conveyance portion12is disposed inside the cooling chamber8. This cooling chamber-side conveyance portion12is a belt conveyor type conveyance portion.

The cooling chamber-side conveyance portion12includes a cooling chamber-side motor61as a drive source disposed outside the cooling chamber8, an output transmitting member62that transmits an output of the cooling chamber-side motor61from the outside of the cooling chamber8to the inside of the cooling chamber8at a predetermined fixed position, a drive shaft63and a driven shaft64to be rotated by the output transmitting member62, a pair of chains65and65that are disposed inside the cooling chamber8, and displace the conveyance tray2in the conveyance direction A1by receiving power from the output transmitting member62, and a movable joint portion67to join a chain unit66including the drive shaft63, the driven shaft64, and the chains65and65to the upper member50in a relatively displaceable manner in the up-down direction Z1.

The cooling chamber-side motor61is, for example, an electric motor. The cooling chamber-side motor61is disposed on a downstream side in the conveyance direction A1in the cooling chamber8at the rear side (outer surface side) of the rear wall8dof the cooling chamber8. The housing61aof the cooling chamber-side motor61is fixed to a cylindrical motor bracket68by using a fixing member such as a bolt. This motor bracket68is fixed to the rear wall8dby using a fixing member such as a bolt.

Between a portion of the motor bracket68facing the rear wall8dand the rear wall8d, a sealing member (not shown) is disposed, and as a result, between the housing61aand the rear wall8dare sealed airtightly. To an output shaft (not shown) of the cooling chamber-side motor61, one end portion of the output transmitting member62is joined rotatably in an interlocking manner.

In detail, the output shaft of the cooling chamber-side motor61is directed in the up-down direction Z1, and the output transmitting member62is directed in the front-rear direction Y1(horizontal direction). These output shaft and output transmitting member62are joined rotatably in an interlocking manner via a mechanism of a gear pair with intersecting axes such as a bevel gear pair.

The output transmitting member62extends to the inside of the cooling chamber8at a position on a downstream side in the conveyance direction A1in the cooling chamber8through a hole portion8iformed in the rear wall8d. The output transmitting member62includes one end portion62a, a universal joint62b, an intermediate shaft62c, a universal joint62d, and an outer end portion62e, and the one end portion62a, the universal joint62b, the intermediate shaft62c, the universal joint62d, and the other end portion62eare arranged in this order. Thus, by including the universal joints62band62d, the output transmitting member62can change the relative positions of the one end portion62aand the other end portion62e. In particular, in the present embodiment, the other end portion62ecan be displaced in the up-down direction Z1with respect to the one end portion62a.

To the other end portion62eof the output transmitting member62, the drive shaft63is joined rotatably together. The drive shaft63is disposed on a downstream side of the cooling chamber8in the conveyance direction A1. The drive shaft63extends along the front-rear direction Y1orthogonal to the conveyance direction A1. Accordingly, an output of the cooling chamber-side motor61can be transmitted to the drive shaft63.

The driven shaft64is disposed parallel to the drive shaft63. The driven shaft64is disposed near the inlet8gof the cooling chamber8. Between the drive shaft63and the driven shaft64, the lower member49is disposed. To a pair of end portions of the drive shaft63in the front-rear direction Y1and a pair of end portions of the driven shaft64in the front-rear direction Y1, sprockets are respectively joined rotatably together. Around pairs of sprockets arranged in the conveyance direction A1, chains65and65are wound. The chains65and65are disposed away from each other in the front-rear direction Y1, which are a configuration enabled to allow the frame portion2aof the conveyance tray2to be placed on. Between the chains65and65, an upper end portion of the lower member49is disposed. Thus, the upper end portion of the lower member49is surrounded by the drive shaft63, the driven shaft64, and the pair of chains65and65.

In the present embodiment, in the front-rear direction Y1, a distance between the chains65and65is set to be equal to or longer than an entire length of the workpiece100. With the configuration described above, in accordance with driving of the cooling chamber-side motor61, the output transmitting member62rotates, and this rotation is transmitted to the drive shaft63. Then, this drive shaft63drives the chains65and65and rotates the driven shaft64. That is, by driving the cooling chamber-side motor61, the pair of chains65and65rotate. Accordingly, the conveyance tray2on the pair of chains65and65moves in the conveyance direction A1.

As described above, the drive shaft63, the driven shaft64, and the pair of chains65and65described above constitute the chain unit66. This chain unit66is supported to be displaceable in the up-down direction Z1by the movable joint portion67. The chain unit66is configured to be capable of being joined to the vertical displacement mechanism43via the movable joint portion67and the upper member50, and capable of being displaced to the conveyance position P3and the cooling position P4.

The chain unit66at the conveyance position P3supports the conveyance tray2so that the conveyance tray2is away from the upper member50and the lower member49, and, the chain unit66at the cooling position P4disposes the conveyance tray2so that the conveyance tray2comes into contact with the lower member49.

The movable joint portion67includes a pair of beam portions69and70, a plurality of brackets71, and a plurality of guide receiving portions72.

The pair of beam portions69and70are provided as beam-shaped portions extending along the conveyance direction A1. One beam portion69is disposed parallel to the chain65at the rear side (rear wall8dside) of the chain65, and supports one end portion of the drive shaft63and one end portion of the driven shaft64rotatably. The other beam portion70is disposed parallel to the chain65at the front side (front wall8cside) of the chain65, and supports the other end portion of the drive shaft63and the other end portion of the driven shaft64rotatably.

The pair of beam portions69and70are fixed to the plurality of brackets71. The plurality of brackets71are provided to join the pair of beam portions69and70to the upper member50. Each bracket71is formed into, for example, an L shape. The brackets71and71are fixed to both end portions in the conveyance direction A1of one beam portion69, and both ends of the one beam portion69are supported. To both end portions in the conveyance direction A1of the other beam portion70, the brackets71and71are fixed, and both ends of the other beam portion70are supported.

A lower end portion of each bracket71is fixed to a corresponding beam portion69or70. In each bracket71, a lower surface71aof a portion extending horizontally is received by an upper surface of the flange portion50aof the upper member50. The brackets71can be displaced upward with respect to the flange portion50a.

To lower end portions of the respective beam portions69and70, guide receiving portions72are fixed. The guide receiving portions72are disposed at, for example, a plurality of positions (in the present embodiment, two positions) on each of the beam portions69and70in the conveyance direction A1. In each guide receiving portion72, a guide hole portion72aextending vertically is formed. In addition, a guide shaft73that can be fit in this guide hole portion72ais provided.

The guide shaft73is provided for each guide hole portion72a, and fixed to a corresponding one of lower portion stays74and74. The lower portion stays74and74are fixed to the front wall8cor the rear wall8d. Each guide shaft73is fit in a corresponding guide hole portion72avertically slidably. Accordingly, movements of the pair of beam portions69and70in the up-down direction Z1are guided.

To each of the lower portion stays74and74, a stopper75is fixed. The stopper75is formed by using, for example, a bolt, and screw-coupled to a corresponding one of the lower portion stays74and74. Accordingly, the position of the stopper75in the up-down direction Z1can be adjusted.

Referring toFIG. 13andFIG. 15, the stopper75on the rear wall8dside faces a lower end portion of the beam portion69on the rear wall8dside in the up-down direction Z1. On the other hand, the stopper75on the front wall8cside faces a lower end portion of the beam portion70on the front wall8cside in the up-down direction Z1. When the pair of beam portions69and70reach the predetermined cooling position P4, each of the beam portions69and70is received by a corresponding stopper75, and is restrained from further moving downward.

On the front wall8cand the rear wall8d, upper portion stays76and76are respectively provided. To each of the upper portion stays76and76, a stopper77is fixed. The stopper77is formed by using, for example, a bolt, and screw-coupled to a corresponding one of the upper portion stays76and76. Accordingly, the position of the stopper77in the up-down direction Z1can be adjusted.

The stopper77on the rear wall8dside faces the bracket71of the beam portion69on the rear wall8dside in the up-down direction Z1. On the other hand, the stopper77on the front wall8cside faces the bracket71of the beam portion70on the front wall8cside in the up-down direction Z1. When the pair of beam portions69and70reach the predetermined conveyance position P3, each bracket71is received by a corresponding stopper77, and the pair of beam portions69and70are restrained from further moving upward.

With the configuration described above, when the upper member50lifts each bracket71, the upper member50and the chain unit66are capable of being integrally displaced in the up-down direction Z1. When the upper member50is positioned at the conveyance position P3, the upper member50lifts the pair of beam portions69and70. In this state, the cooling chamber-side conveyance portion12receives the conveyance tray2from the intermediate conveyance portion13and conveys the conveyance tray2by operation of the chains65and65. Then, the power transmitting member62is rotated by driving of the cooling chamber-side motor61, and the drive shaft63accordingly rotates, and as a result, the chains65and65rotate.

When the conveyance tray2reaches the predetermined conveyance position P3, the chains65stop, and the conveyance tray2stops at the conveyance position P3. At this time, by operating the moving up/down mechanism57of the vertical displacement mechanism43, the cylinder57bis displaced downward. Accordingly, the upper member50, the pair of beam portions69and70, and the chain unit66are displaced downward. Then, as shown inFIG. 15andFIG. 16, the pair of beam portions69and70are received by the lower stopper75, and accordingly, the chain unit66is held at the cooling position P4. At this time, the rim portion of the hole portion2cof the conveyance tray2is received by the upper end portion49aof the lower member49.

Then, when the rod57bof the moving up/down mechanism57is further displaced downward, contact of the upper member50with the bracket71is released, and the lower end portion of the upper member50presses the conveyance tray2downward. Note that, in a groove formed on a lower surface of the flange portion49aof the lower member49, a sealing member such as an O-ring is disposed, and in a groove formed on an upper surface of the flange portion50aof the upper member50, a sealing member such as an O-ring is disposed.

Then, the conveyance tray2becomes sandwiched between the lower member49and the upper member50, and the sealing members described above liquid-tightly seal the portions between the conveyance tray2and the upper member50and between the conveyance tray2and the lower member49. Then, a coolant passage48is defined by the lower member49, the conveyance tray2, and the upper member50. Thus, with the configuration in which the upper member50and the lower member49are brought into contact with the conveyance tray2from above and below, a stroke (vertical movement amount) of the upper member50can be reduced, so that the heat treatment apparatus1can be made more compact.

Referring toFIG. 14toFIG. 16, the coolant passage48is a passage extending along the up-down direction Z1. This coolant passage48is defined by an inner circumferential surface of the introduction pipe51, an inner circumferential surface of the lower member49, an inner circumferential surface of the hole portion2cof the conveyance tray2, and an inner circumferential surface of the upper member50, and is opened upward inside the cooling chamber8. Inside the coolant passage48, the workpiece100is surrounded by the upper member50. Inside the coolant passage48, a coolant flows from the lower side to the upper side toward the workpiece100supported by the support portions2bof the conveyance tray2.

Then, the workpiece100supported by the conveyance tray2is soaked in the coolant, and is cooled by the coolant. At this time, the support portions2bof the conveyance tray2function as rectifying members to rectify the coolant in the coolant passage48. This coolant reaches an upper end of the coolant passage48(an upper end of the upper member50), and then reaches the outside of the coolant passage48and falls toward the bottom wall8fof the cooling chamber8. The coolant that fell onto the bottom wall8fpasses through the discharge pipe52attached to the rear wall8d, and is returned to the coolant tank (not shown) outside the cooling chamber8.

A flow volume, a flow rate, and a supply timing of the coolant to the coolant passage48are controlled by operation of a pump provided in a coolant storage tank (not shown). This enables, for example, uniform extinguishment of a vapor film on the workpiece100and cooling of the workpiece100without being pearlite and bainite nose. Uniform cooling while reducing the flow rate enables control of martensitic transformation timing. As a result, low-distortion treatment is enabled, and variation in heat deformation amount of the workpiece100can be reduced.

After cooling treatment is completed, the rod57bof the moving up/down mechanism57of the vertical displacement mechanism43is displaced upward as shown inFIG. 12toFIG. 15. Accordingly, the upper member50is displaced upward, and when the bracket71comes into contact with the flange portion50aof the upper member50, the bracket71and the chain unit66are displaced upward. Then, when the bracket71comes into contact with the stopper77, operation of the moving up/down mechanism57stops.

Accordingly, the conveyance tray2is displaced upward together with the chain unit66and returned to the conveyance position P3. At this time, due to upward displacement of the upper member50with respect to the conveyance tray2, the coolant inside the upper member50instantly falls to the outside of the upper member50. Accordingly, the workpiece100surrounded by the upper member50can be quickly taken out from the coolant. Therefore, for example, marquenching that is effective for low-distortion treatment can also be easily performed.

Next, according to driving of the cooling chamber-side motor61, the chains65and65of the chain unit66rotate, and the conveyance tray2moves to the outlet door45side. Then, the outlet door45is opened, and accordingly, the conveyance tray2and the workpiece100are carried out of the cooling chamber8.

As described above, in the heat treatment apparatus1, the workpiece100is supported by the conveyance tray2, and this conveyance tray2is conveyed in the conveyance path B1by the first conveyance mechanism3. Accordingly, the first conveyance mechanism3conveys the workpiece100not directly but via the conveyance tray2. Therefore, the first conveyance mechanism3can convey the conveyance tray2in a stable posture without being influenced by the shape of the workpiece100. As a result, the workpiece100is conveyed in a more stable posture. In addition, by a simple configuration using the conveyance tray2for conveyance of the workpiece100, the workpiece100is conveyed in a stable posture. Thus, by the simple configuration, the heat treatment apparatus1capable of more reliably conveying the workpiece100along the desired conveyance path B1can be realized.

In addition, in the heat treatment apparatus1, the second conveyance mechanism18to move the workpiece100between the conveyance tray2and the heating member17in the heating chamber7is provided. With this configuration, the workpiece100can be heated by the heating member17. At the time of this heating, the workpiece100is away from the conveyance tray2. Therefore, the conveyance tray2is prevented from being heated by the heating member17and the workpiece100. Accordingly, defects of the conveyance tray2caused by heat distortion can be more reliably suppressed. Therefore, the life of the conveyance tray2(the number of times of reuse of the conveyance tray2) can be improved. Further, a conveyance tray2that does not need to be heated can be prevented from being heated, so that through improvement in energy efficiency, energy for the heat treatment apparatus1can be further saved.

In the heat treatment apparatus1, the heating member17is disposed above the conveyance path B1. With this configuration, since the heating member17is disposed away from the conveyance path B1, the heat treatment apparatus1can be prevented from becoming long in the conveyance direction A1. In addition, since the heating member17is disposed above the conveyance path B1, heat from the heating member17is transferred to a portion above the heating member17, and is prevented from being transferred to the conveyance path B1side. Accordingly, the conveyance tray2can be more reliably prevented from being heated.

In the heat treatment apparatus1, the second conveyance mechanism18includes a support portion18ato lift the workpiece100through the hole portion2cformed in the conveyance tray2in the heating chamber7. With this configuration, by a simple operation of upward displacement with respect to the conveyance tray2, the support portion18aof the second conveyance mechanism18can lift the workpiece100. Therefore, the configuration of the second conveyance mechanism18can be made simpler.

In addition, in the heat treatment apparatus1, the coolant passage48extends along the up-down direction Z1(vertical direction). With this configuration, since the cooling chamber8can be formed to be vertically long, the size of the heat treatment apparatus1in the horizontal direction can be reduced. The extending direction of the coolant passage48and the conveyance direction A1are orthogonal to each other, so that the heat treatment apparatus1can be prevented from becoming excessively large in each of the horizontal direction and the vertical direction. Therefore, the heat treatment apparatus1can be made more compact.

In the heat treatment apparatus1, the space between the heating chamber7and the cooling chamber8can be closed by the intermediate door33. Accordingly, the atmosphere in the heating chamber7can be made more stable. In addition, a coolant inside the cooling chamber8can be more reliably prevented from flying into the heating chamber7.

In the heat treatment apparatus1, the first conveyance mechanism3is configured to circulate the conveyance tray2between the outside of the heating chamber7, the heating chamber7, the cooling chamber8, and the outside of the cooling chamber8. With this configuration, the conveyance tray2can be repeatedly used for conveyance of the workpiece100in the heat treatment apparatus1. Therefore, the number of conveyance trays2necessary for heat treatment of a large number of workpieces100in the heat treatment apparatus1can be reduced. A possible number of times of reuse of the conveyance tray2is significantly increased by preventing the conveyance tray2from being heated.

In the heat treatment apparatus1, since the heating chamber-side motor22of the first conveyance mechanism3is disposed outside the heating chamber7, the heating chamber7can be made more compact. In addition, the output transmitting member23is configured so as not to move from a fixed position. Therefore, a portion that needs to be sealed between the inside and the outside of the heating chamber7, that is, the portion between the output transmitting member23and the heating chamber7can be made smaller. Accordingly, the first conveyance mechanism3can be realized by a simple configuration.

In the heat treatment apparatus1, the extending direction of the coolant passage48(up-down direction Z1) and the conveyance direction A1of the workpiece100are different from each other. Accordingly, the shape of the heat treatment apparatus1can be prevented from becoming excessively long in any of the extending direction of the coolant passage48and the conveyance direction A1. Therefore, the heat treatment apparatus1can be made more compact. In addition, by displacing the upper member50and the lower member49as a plurality of coolant passage defining members relative to each other so as to separate from each other in the up-down direction Z1, the workpiece100can be let into and out of the coolant passage48. Therefore, it is not necessary to provide a robot arm, etc., to let the workpiece100into and out of the coolant passage48. Accordingly, the heat treatment apparatus1can be made more compact.

In addition, the heat treatment apparatus1is configured so that a cooling liquid as a coolant flows upward from the lower side in the coolant passage48. With this configuration, the coolant passage defining body42can be formed to be vertically long, so that the size of the heat treatment apparatus1in the horizontal direction can be made smaller. In addition, the extending direction of the coolant passage48and the conveyance direction A1are orthogonal to each other, so that the heat treatment apparatus1can be prevented from becoming excessively large in size in each of the horizontal direction and the vertical direction. Therefore, the heat treatment apparatus1can be made more compact. Further, in the coolant passage48, a coolant flows upward from the lower side, so that the coolant can be more uniformly moved upward. Accordingly, the workpiece100can be more uniformly cooled.

In the heat treatment apparatus1, the conveyance tray2defines a part of the coolant passage48. Therefore, an exclusive member to support the conveyance tray2inside the coolant passage48is unnecessary, and the heat treatment apparatus1can be configured to be more compact and simpler.

In the heat treatment apparatus1, the workpiece100is disposed at an intermediate portion of the coolant passage48. To this workpiece100, a coolant is supplied through the hole portion2cof the conveyance tray2. Accordingly, the workpiece100can be more reliably cooled by the coolant while being reliably supported inside the coolant passage48.

In the heat treatment apparatus1, by displacing the upper member50to the lower member49side by the vertical displacement mechanism43, the coolant passage48is formed. In addition, by moving up the upper member50away from the lower member49by the vertical displacement mechanism43, the workpiece100can be exposed from the coolant passage defining body42. This enables letting-in and letting-out of the workpiece100along the conveyance direction A1.

In the heat treatment apparatus1, the chain unit66of the first conveyance mechanism3supports, at the conveyance position P3, the conveyance tray2so that the conveyance tray2is away from the upper member50and the lower member49, and at the cooling position P4, disposes the conveyance tray2so that the conveyance tray2comes into contact with the lower member49. With this configuration, when the chain unit66is disposed at the conveyance position P3, the chain unit66can support the conveyance tray2in a state where this conveyance tray2does not collide with other members. Accordingly, the conveyance tray2can be smoothly conveyed. On the other hand, when the chain unit66is disposed at the cooling position P4, the conveyance tray2can be disposed so that this conveyance tray2defines a coolant passage48in cooperation with the lower member49. Thus, the vertical displacement mechanism43not only simply displaces the upper member50vertically with respect to the lower member49, but also displaces the chain unit66and the conveyance tray2vertically.

In the heat treatment apparatus1, the vertical displacement mechanism43is configured to displace the upper member50to bring the upper member50into contact with the conveyance tray2when the conveyance tray2is at the cooling position P4. With this configuration, by displacing the upper member50downward by the vertical displacement mechanism43, the upper member50and the lower member49can be made to sandwich the conveyance tray2. As a result, the coolant passage48can be defined by cooperation of the upper member50, the conveyance tray2, and the lower member49.

In the heat treatment apparatus1, the support portions2bof the conveyance tray2function as rectifying members to rectify a coolant inside the coolant passage48. With this configuration, a larger amount of coolant can be brought into uniform contact with the workpiece100per unit time, so that distortion of the workpiece100can be suppressed.

Referring toFIG. 17as a schematic configuration diagram of the heat treatment apparatus1to describe the effects of the heat treatment apparatus1, the coolant passage48is disposed across the first conveyance mechanism3vertically. In addition, vertically extending disposition of the coolant passage48is adopted, and disposition of the heating member17and the second conveyance mechanism18arranged one above the other is adopted. With this configuration, in the heat treatment apparatus1, a layout compact in the up-down direction Z1as well can be realized.

An embodiment of the present invention is described above, however, the present invention is not limited to the embodiment described above. The present invention can be variously modified within the scope of the claims.

For example, inside the coolant passage48, a rectifying member such as a fin or a rectifying duct to rectify a coolant may be fixed. Accordingly, a coolant flowing direction around the workpiece100can be further uniformized.

INDUSTRIAL APPLICABILITY

The present invention can be widely applied as a heat treatment apparatus.

REFERENCE SIGNS LIST