Transfer device and machine tool

Abstract

To provide a conveyance device and a machine tool, which improve a degree of freedom in design and a degree of freedom in an object to be conveyed.SOLUTION: A conveyance device includes: a hand which grips an object and is rotatably movable; an arm which conveys the object gripped by the hand; a motor (a hand motor 63) which drives the hand through a speed reduction mechanism (a hand speed reduction mechanism 64); and a casing (a hand casing 6) which is supported by the arm and stores the motor and the speed reduction mechanism. The speed reduction mechanism has an input shaft (a hand input shaft 641) to which a motor output shaft (a hand motor output shaft 63a) of the motor is coaxially connected and an output shaft (a hand output shaft 642) for speed-reducing and transmitting rotation of the input shaft to the hand. The hand rotates and moves around the output shaft and a shaft length direction of the motor output shaft crosses a longitudinal direction of the arm.SELECTED DRAWING: Figure 10

Description

Technical Field

[0001] The present disclosure relates to a conveying device and a machine tool.

Background Art

[0002] In recent years, conveying devices for conveying objects such as tools or workpieces have become widespread. The conveying device described in Patent Document 1 includes a hand and an arm. The arm is hollow and houses a motor. The output shaft of the motor extends along the longitudinal direction of the arm. By driving the hand with the motor, the hand rotates around a predetermined axis orthogonal to the longitudinal direction of the arm. The hand grips the object. The object gripped by the hand rotates together with the hand. The arm conveys the object gripped by the hand, for example, inside and outside a machine tool.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In order to house the motor, the width of the arm (the length in the direction along the rotation axis of the hand) cannot be made less than the width of the motor. When the width of the arm is large, the size or shape of the object may be restricted so that the arm and the object do not interfere with each other. However, if a motor with a narrow width is used for the purpose of narrowing the width of the arm, there is a risk that the output torque of the motor will be insufficient.

[0005] An object of the present disclosure is to provide a conveying device and a machine tool in which the degree of freedom in design and the degree of freedom in the object to be conveyed are improved.

Means for Solving the Problems

[0006] The transfer device according to the present disclosure includes a hand that grips an object and is rotatable, an arm that transfers the object gripped by the hand, a motor that drives the hand via a speed reduction mechanism, and a casing that is supported by the arm and houses the motor and the speed reduction mechanism. The speed reduction mechanism has an input shaft coaxially connected to the motor output shaft of the motor, and an output shaft for reducing and transmitting the rotation of the input shaft to the hand. The hand rotates around the output shaft, and the axial length direction of the motor output shaft intersects the longitudinal direction of the arm. The conveying device according to the present disclosure includes a hand that grips an object and is rotatably movable, an arm that conveys the object gripped by the hand, a motor that drives the hand via a speed reduction mechanism, and a casing that is supported by the arm and houses the motor and the speed reduction mechanism. The speed reduction mechanism has an input shaft coaxially connected to the motor output shaft of the motor, and an output shaft for reducing and transmitting the rotation of the input shaft to the hand. The axial length direction of the motor output shaft is orthogonal to the longitudinal direction of the arm. A part of the casing protrudes from the outer surface of the arm to one side in the axial length direction. The hand rotates and moves around the output shaft so as to face the outer peripheral surface of the part of the casing.

[0007] In the present disclosure, the casing supported by the arm houses the motor and the speed reduction mechanism. Since the arm does not house the motor, the designer of the transfer device can determine the width of the arm and the size of the motor independently of each other. That is, the degree of freedom in the design of the transfer device is improved. Since the width of the arm can be made sufficiently narrow, the size, shape, or orientation of the object gripped by the hand is not restricted. That is, the degree of freedom of the object to be transferred is improved.

[0008] The axial length direction of the motor output shaft of the motor intersects the longitudinal direction of the arm. The speed reduction mechanism has an input shaft and an output shaft. The motor output shaft is coaxially connected to the input shaft. The rotation of the motor output shaft is transmitted to the input shaft, and the rotation of the input shaft is reduced and transmitted to the hand via the output shaft, so that the hand rotates around the output shaft.

[0009] Since it is not necessary to use a small motor for the purpose of narrowing the width of the arm, a large motor having sufficient output torque can be used. Therefore, it is not necessary to interpose a plurality of speed reduction mechanisms between the motor and the hand to compensate for the lack of output torque of the motor. That is, the transfer device can be made smaller and lighter and the number of parts can be reduced.

[0010] The transfer device according to the present disclosure is characterized in that the axial length direction is perpendicular to the longitudinal direction, a part of the casing protrudes from the outer surface of the arm to one side in the axial length direction, and the hand rotates around the part of the casing.

[0011] In the present disclosure, an arm and a part of the casing constitute one side and the other side of an L shape. Since the hand rotates around a part of the casing, the space inside the L shape (the space surrounded by the arm and the casing) can be effectively utilized. Therefore, it is possible to prevent an object grasped by the hand from interfering with surrounding objects (for example, members constituting a machine tool) during conveyance. Hereinafter, a motor and a speed reduction mechanism related to the rotational movement of the hand are referred to as a hand motor and a hand speed reduction mechanism, and a casing that houses the hand motor and the hand speed reduction mechanism is referred to as a hand casing.

[0012] The conveying device according to the present disclosure, wherein the arm has a first arm that can swing, and a second arm whose tip supports the casing and whose base end is connected to the tip of the first arm and can swing, and further includes a first motor that drives the first arm via a first speed reduction mechanism, the first speed reduction mechanism has a first input shaft coaxially connected to a first motor output shaft of the first motor, and a first output shaft for reducing and transmitting the rotation of the first input shaft to the first arm, and the first arm swings around the first output shaft.

[0013] In the present disclosure, each of the first arm and the second arm can swing. The base end of the second arm is connected to the tip of the first arm. The tip of the second arm supports the hand casing. The first speed reduction mechanism has a first input shaft and a first output shaft. The first motor output shaft of the first motor is coaxially connected to the first input shaft. The rotation of the first motor output shaft is transmitted to the first input shaft, and the rotation of the first input shaft is reduced and transmitted to the first arm via the first output shaft, whereby the first arm swings around the first output shaft.

[0014] Since the second arm is lightweight, the torque required to drive the first arm to which the second arm is connected is small. Therefore, there is no need to interpose a plurality of speed reduction mechanisms between the first motor and the first arm to compensate for the shortage of the output torque of the first motor. That is, it is possible to reduce the size and weight of the transfer device and the number of components.

[0015] The transfer device according to the present disclosure further includes a pipe extending across the tip of the first arm and the base of the second arm, a second motor for driving the second arm, a hollow base for supporting the first arm, a first casing provided between the base and the base of the first arm for housing the first motor and the first speed reduction mechanism, a torque-resistant cable for supplying power to the motor, a first cable for supplying power to the first motor, a second cable for supplying power to the second motor, and connectors for connecting the torque-resistant cable, the first cable, and the second cable to a power supply cable extending from a power source. The second arm swings around the pipe, each of the first arm and the second arm is hollow, the first arm houses the second motor, the torque-resistant cable is arranged inside the base from inside the casing, inside the second arm, inside the pipe, inside the first arm, and outside the first casing, the second cable is arranged inside the base from outside the first casing, the first cable is arranged inside the base from inside the first casing, and the connector is arranged inside the base. The above-mentioned characterized in that the second cable is arranged inside the base through the outside of the first casing, the first cable is arranged inside the base from inside the first casing, and the connector is arranged inside the base.

[0016] In the present disclosure, the second arm driven by the second motor swings around a pipe extending across the tip of the first arm and the base of the second arm. The base is hollow, and a first casing is provided between the base and the base of the first arm. The first casing houses the first motor and the first speed reduction mechanism. The first arm is hollow and houses the second motor. The second arm is hollow.

[0017] The anti-twist cable for supplying power to the hand motor is arranged inside the base through the inside of the hand casing, the inside of the second arm, the inside of the pipe, the inside of the first arm, and the outside of the first casing. Since the first arm and the second arm swing relative to each other, the anti-twist cable passing through both of them may be twisted. However, since the anti-twist cable is resistant to twisting, the risk of wire breakage due to twisting can be reduced.

[0018] The second cable for supplying power to the second motor is arranged inside the base through the outside of the first casing from the inside of the first arm. The first cable for supplying power to the first motor is arranged inside the hollow base from the inside of the first casing.

[0019] The second arm swings relative to the first casing, but each of the anti-twist cable and the second cable bypasses the first casing from the second arm and extends to the base, so there is no risk of twisting. Since the first casing and the base do not swing relative to each other, the first cable passing through both of them will not be twisted. As a result, there is no risk of the first cable and the second cable breaking due to twisting, and neither the first cable nor the second cable needs to have anti-twist properties.

[0020] Each of the anti-twist cable, the first cable, and the second cable is connected to the power supply cable extending from the power source via a connector. Since the connector is arranged inside the base, leakage due to the attachment of conductive foreign matter to the connection part by the connector can be suppressed.

[0021] The conveying device according to the present disclosure is characterized in that the base end portion of the first arm is located below the tip end portion of the first arm, and is connected to the side wall of the base at the base end portion of the first arm outside the first casing, and further includes a flexible tube through which the anti-twist cable and the second cable pass.

[0022] In the present disclosure, the twist-resistant cable and the second cable are arranged inside the base through a flexible tube that is inside the first arm and outside the first casing. Therefore, since the portions of the twist-resistant cable and the second cable that pass outside the first casing can be protected by the flexible tube, the risk of wire breakage can be reduced.

[0023] The conveying device according to the present disclosure is provided inside the base and further includes a housing chamber for housing the connector.

[0024] In the present disclosure, the housing chamber provided inside the base houses the connector. Since the connector is doubly surrounded, it is possible to prevent electric leakage caused by the attachment of foreign matter having conductivity to the connection portion by the connector. Here, the foreign matter having conductivity is, for example, a conductive liquid, such as water or cutting oil containing cutting chips. Hereinafter, liquid foreign matter is exemplified as the foreign matter, and unless otherwise specified, the liquid foreign matter is simply referred to as foreign matter.

[0025] The machine tool according to the present disclosure includes the conveying device according to the present disclosure, and is characterized in that the work conveyed by the conveying device is processed.

[0026] In the present disclosure, since the conveying device according to the present disclosure is provided, the degree of freedom in design and the degree of freedom of the object to be conveyed are improved.

Effects of the Invention

[0027] According to the conveying device and the machine tool of the present disclosure, the degree of freedom in design and the degree of freedom of the object to be conveyed are improved.

Brief Description of the Drawings

[0028]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Embodiments for Carrying Out the Invention

[0029] Hereinafter, embodiments of the present disclosure will be described. In the following description, up and down, front and back, and left and right indicated by arrow signs in the drawings are used.

[0030] FIG. 1 is a perspective view of a machine tool according to an embodiment. In the figure, 1 is a machine tool, and the machine tool 1 is installed in a factory. The machine tool 1 includes a machine body 11, a body cover 12, a conveying device 13, and a control device 14. The machine body 11 performs cutting on a workpiece W (see FIG. 11 described later). When machining the workpiece W, the machine body 11 uses cutting oil (coolant) to cool the workpiece W and wash the cutting chips, etc. The body cover 12 is a wall that covers the machining area where the machine body 11 processes the workpiece W from the front, back, left, and right. An opening 121 is provided in the right wall of the body cover 12. A door 122 that slides in the front-rear direction opens and closes the opening 121.

[0031] The transfer device 13 is a workpiece exchange device that transfers the workpiece W in and out of the body cover 12 through the opening 121. The control device 14 is provided behind the body cover 12. The control device 14 includes a CPU, a ROM, a RAM, etc. The CPU controls the operation of the machine tool 1 by loading the control program stored in the ROM into the RAM and executing it.

[0032] The transfer device 13 includes a support portion 131 and an arm device 132. The support portion 131 is fixed to the lower part on the right side of the machine body 11. The support portion 131 supports the arm device 132 so as to be movable in the front-rear direction. The arm device 132 is driven by a drive portion (not shown) when transferring the workpiece W and reciprocates in the front-rear direction. Hereinafter, the description of the front-rear movement of the arm device 132 will be omitted. The arm device 132 rises from the support portion 131 and is located on the right side of the opening 121.

[0033] Figures 2 and 3 are a perspective view and a cross-sectional view of the arm device 132. The arm device 132 includes a base 2, a first casing 3, a first arm 4, a second arm 5, and a hand casing 6. The base 2 constitutes the lower part of the arm device 132, and the support portion 131 directly supports the base 2 (see Figure 1).

[0034] Figure 4 is a cross-sectional view of the base 2. The base 2 has a rectangular box shape extending in the vertical direction. The front wall 2a of the base 2 is openable and functions as a lid for the base 2. Inside the base 2, a storage chamber 21 is provided. The rear wall of the storage chamber 21 also serves as the rear wall of the base 2. The storage chamber 21 has a front opening 211 and a bottom opening 212. Except for the front opening 211 and the bottom opening 212, the inside of the storage chamber 21 is liquid-tightly partitioned from the external space. The front opening 211 is liquid-tightly covered by a lid plate 22 that can be opened and closed. The bottom opening 212 is covered by an elastic member 23. The elastic member 23 is, for example, a sponge, and an angled support 213 fixed to the peripheral edge of the bottom opening 212 supports the elastic member 23.

[0035] The base 2 has openings 24, 25. The opening 24 is provided at the lower part of the side wall (the rear wall in this embodiment) of the base 2 and is located below the storage chamber 21. The opening 25 is provided in the bottom wall of the base 2 and is located directly below the bottom opening 212.

[0036] As shown in FIGS. 2 and 3, the first casing 3 is integrally provided on the upper part of the base 2. The base 2 supports the first casing 3. FIG. 5 is a cross-sectional view of the first casing 3. The first casing 3 has a cylindrical shape with its axial length direction facing front and back. The first casing 3 has a partition wall 301. The partition wall 301 is integrally provided on the inner surface of the first casing 3 and divides the internal space of the first casing 3 into two parts in the front and back directions. A through hole 302 that penetrates the partition wall 301 in the front and back directions is provided at the central part of the partition wall 301.

[0037] A part of the lower part of the peripheral wall of the first casing 3 that is in front of the partition wall 301 is open. The upper surface of the base 2 is open toward the lower opening of the first casing 3, and the internal space of the first casing 3 and the internal space of the base 2 communicate with each other through both openings. The first casing 3 has an auxiliary case 303 (see FIGS. 2 and 3). The auxiliary case 303 has a bottomed cylindrical shape. The auxiliary case 303 is fixed to the front part of the first casing 3 such that the bottom surface faces forward and the top surface opening faces the front end opening of the first casing 3.

[0038] The first casing 3 houses a first motor 31, a first speed reduction mechanism 32, and a first coupling 33. The first motor 31 is a known electric motor having water resistance and oil resistance. The first motor output shaft 31a of the first motor 31 faces forward and backward. The main body of the first motor 31 is fixed to the first casing 3 using appropriate fixing tools from the front side of the partition wall 301 to the auxiliary case 303. The first motor output shaft 31a penetrates the through hole 302 of the partition wall 301 from the front side.

[0039] The first speed reduction mechanism 32 is a known speed reducer, and includes a first input shaft 321, a first output shaft 322, and a first housing 323. The first input shaft 321 and the first output shaft 322 are coaxial with each other, and the axial length directions of both face forward and backward. The first housing 323 has a cylindrical shape, and the axial length direction faces forward and backward. The first housing 323 houses the first input shaft 321 and the first output shaft 322 such that the front end portion of the first input shaft 321 protrudes forward from the front end opening of the first housing 323, and the rear end portion of the first output shaft 322 is exposed from the rear end opening of the first housing 323. The first housing 323 also houses gears (not shown) for reducing the rotation of the first input shaft 321 and transmitting it to the first output shaft 322.

[0040] The disk 34 of the first arm 4 covers the rear end opening of the first casing 3 from the rear side (see FIGS. 2 and 3). Hereinafter, the space surrounded by the disk 34, the peripheral wall of the first casing 3, and the partition wall 301 is referred to as the first speed reduction chamber 35.

[0041] The first housing 323 is located in the first speed reduction chamber 35. The first housing 323 is fixed to the first casing 3 using appropriate fixing tools. The first input shaft 321 extends toward the through hole 302 of the partition wall 301 and is coaxially connected to the first motor output shaft 31a via the first coupling 33. The first motor output shaft 31a rotates forward and backward, and the rotation of the first motor output shaft 31a is transmitted to the first input shaft 321. The first output shaft 322 is fixed coaxially to the disk 34. The disk 34 is rotatable integrally with the first output shaft 322 about the first output shaft 322.

[0042] The inside of the first housing 323 is filled with a lubricant. The lubricant is interposed between the first input shaft 321 and the first output shaft 322. The first casing 3 houses a plurality of seals. By each of the plurality of seals being interposed between the first reduction mechanism 32 and a member adjacent to the first reduction mechanism 32, the lubricant is sealed in a liquid-tight manner. Therefore, it is not necessary to configure the entire first casing 3 in a liquid-tight manner. The number and arrangement of the seals are not limited.

[0043] In the present embodiment, the lubricant can flow out from the front-end opening of the first housing 323 into the first reduction chamber 35. An O-ring 361 is interposed between the inner surface of the peripheral wall of the first casing 3 and the outer peripheral surface of the front-end portion of the first housing 323. An oil seal 362 is interposed between the first input shaft 321 and the peripheral edge of the rear-side opening of the through-hole 302 of the partition wall 301.

[0044] The O-ring 361 can prevent the lubricant that has flowed out into the first reduction chamber 35 from flowing rearward along the outer surface of the first housing 323 and leaking from the rear-end opening of the first casing 3. The oil seal 362 can prevent the lubricant that has flowed out into the first reduction chamber 35 from flowing through the through-hole 302 to the front side of the partition wall 301 and leaking from the front-end opening or the lower opening of the first casing 3. The O-ring 361 and the oil seal 362 can prevent foreign matter from entering the first reduction chamber 35 and mixing into the lubricant.

[0045] As shown in FIGS. 2 and 3, the base end portion (the lower end in FIG. 3) of the first arm 4 is adjacent to the rear side of the first casing 3. The base end portion (the upper end in FIG. 3) of the second arm 5 is adjacent to the rear side of the tip end portion of the first arm 4. The first arm 4 and the second arm 5 constitute the arms of the present embodiment. FIG. 5 also shows a cross-section of the proximal end of the first arm 4. As shown in FIGS. 2, 3, and 5, the proximal end of the first arm 4 integrally has a disk 34. The first arm 4 is rotatable integrally with the disk 34. In other words, the proximal end of the first arm 4 is connected to the first casing 3 via the first reduction mechanism 32, and the first arm 4 is swingable about the first output shaft 322. The base 2 supports the first arm 4 via the first casing 3.

[0046] The first motor 31 drives the first arm 4 via the first reduction mechanism 32, the first coupling 33, and the disk 34. Due to the intervention of the first reduction mechanism 32, the rotation of the first motor output shaft 31a is decelerated and transmitted to the first arm 4. The first arm 4 driven by the first motor 31 swings about the first output shaft 322. The first arm 4 can be stationary in the home position where the longitudinal direction is vertically oriented (see FIGS. 2 and 3). The distal end of the first arm 4 can reciprocate left and right about the home position.

[0047] As shown in FIGS. 2 and 3, the first arm 4 includes a first arm main body 41 and a front-stage casing 42. The first arm main body 41 has a rectangular box shape that is long in one direction. The lower end of the first arm main body 41 is fixed to the disk 34 (see FIG. 5). The front surface of the first arm main body 41 is open. The front-stage casing 42 is integrally provided at the upper end of the first arm main body 41. The front-stage casing 42 has a cylindrical shape with the axial length direction facing front and back. As shown in FIG. 3, a first cover plate 43 common to both covers the front surface opening of the first arm main body 41 and the front end opening of the front-stage casing 42 in an openable and closable manner.

[0048] FIG. 6 is a cross-sectional view of the distal end of the first arm 4 and the proximal end of the second arm 5. The front-stage casing 42 has a partition wall 421. The partition wall 421 is integrally provided on the inner surface of the front-stage casing 42 and divides the internal space of the front-stage casing 42 into two parts in the front and back directions. A through hole 422 that penetrates the partition wall 421 in the front and back directions is provided at the central portion of the partition wall 421. A part of the lower part of the peripheral wall of the front casing 42, which is in front of the partition wall 421, is open. The upper surface of the first arm body 41 is open toward the lower opening of the front casing 42, and the internal space of the front casing 42 and the internal space of the first arm body 41 communicate with each other through the openings of both.

[0049] A through hole 401 is provided across the lower part of the peripheral wall of the front casing 42 and the upper surface of the first arm body 41 behind the partition wall 421. The axial length direction of the through hole 401 is vertical. The first arm body 41 houses a communication pipe 411. The axial length direction of the communication pipe 411 is vertical. The communication pipe 411 is fixed to the first arm body 41 by inserting the upper end portion of the communication pipe 411 into the through hole 401 from below. An O-ring 412 is interposed hermetically between the outer peripheral surface of the communication pipe 411 and the inner peripheral surface of the through hole 401. The internal space of the front casing 42 and the internal space of the first arm body 41 communicate with each other through the through hole 401 and the communication pipe 411.

[0050] As shown in FIGS. 2 and 3, the second arm 5 includes a second arm body 51 and a second casing 52. The second arm body 51 has a rectangular box shape that is long in one direction. The front surface of the second arm body 51 is open. As shown in FIG. 3, the front opening of the second arm body 51 is covered by a second cover plate 53 so as to be openable and closable. The second casing 52 has a bottomed cylindrical shape, the axial length direction is forward and backward, and it is integrally provided at the upper end portion of the second arm body 51 so as to open forward.

[0051] As shown in FIG. 6, the second casing 52 has a partition wall 521. The partition wall 521 is integrally provided on the inner surface of the second casing 52 and divides the internal space of the second casing 52 into two parts in the front and rear directions. A through hole 522 that penetrates the partition wall 521 in the front and rear directions is provided at the central portion of the partition wall 521. The front-end opening of the second casing 52 and the rear-end opening of the front-stage casing 42 of the first arm 4 face each other such that the through-holes 422 and 522 are coaxial with each other. Hereinafter, the space surrounded by the peripheral wall of the second casing 52, the peripheral wall of the front-stage casing 42, and the partition walls 421 and 521 is referred to as the second reduction chamber 70.

[0052] A part behind the partition wall 521 is open at the lower part of the peripheral wall of the second casing 52. The upper surface of the second arm main body 51 is open toward the lower opening of the second casing 52, and the internal space of the second casing 52 and the internal space of the second arm main body 51 communicate with each other through both openings.

[0053] The first arm 4 and the second arm 5 accommodate a pipe 71 (see FIG. 3). The pipe 71 is cylindrical and extends over the tip of the first arm 4 and the base end of the second arm 5 so that the axial length direction faces forward and backward. The front end of the pipe 71 is fitted into the through-hole 422 of the partition wall 421. The rear end of the pipe 71 is fitted into the through-hole 522 of the partition wall 521. An O-ring 711 is interposed in a liquid-tight manner between the outer peripheral surface of the front end of the pipe 71 and the inner peripheral surface of the through-hole 422. An oil seal 712 is interposed in a liquid-tight manner between the outer peripheral surface of the rear end of the pipe 71 and the inner peripheral surface of the through-hole 522. The pipe 71 is fixed to the partition wall 421 but not to the partition wall 521.

[0054] The first arm 4 accommodates a second motor 44 (see FIGS. 3 and 5). The second motor 44 is a known electric motor having water resistance and oil resistance. The axial length direction of the second motor output shaft 44a of the second motor 44 faces vertically. The main body of the second motor 44 is fixed to the first arm main body 41 using an appropriate fixing tool such that the second motor output shaft 44a penetrates the communication pipe 411 from below.

[0055] The first arm 4 houses the front-stage speed reduction mechanism 45 and the second coupling 46. The front-stage speed reduction mechanism 45 includes a bevel pinion 451 and a bevel gear 452. The bevel pinion 451 penetrates through the through-hole 401 such that its tip is positioned in the second speed reduction chamber 70, and is coaxially connected to the second motor output shaft 44a of the second motor 44 via the second coupling 46. The bevel gear 452 is positioned in the second speed reduction chamber 70. The pipe 71 penetrates coaxially through the axis of the bevel gear 452. The bevel gear 452 is rotatable about the pipe 71 and meshes with the bevel pinion 451.

[0056] The front-stage casing 42 and the second casing 52 house the second speed reduction mechanism 72. The second speed reduction mechanism 72 is a known speed reducer and includes a second input shaft 721, a second output shaft 722, and a second housing 723. The second input shaft 721 and the second output shaft 722 are coaxial with each other, and the axial directions of their respective shafts face forward and backward. The second housing 723 is cylindrical, and its axial direction faces forward and backward. The second housing 723 houses the second input shaft 721 and the second output shaft 722 such that the front end portion of the second input shaft 721 is exposed from the front end opening of the second housing 723 and the rear end portion of the second output shaft 722 protrudes rearward from the rear end opening of the second housing 723. The second housing 723 also houses gears (not shown) for reducing the rotation of the second input shaft 721 and transmitting it to the second output shaft 722.

[0057] The second housing 723 is positioned in the second speed reduction chamber 70 and is fixed to the front-stage casing 42 using appropriate fixing tools. The pipe 71 penetrates coaxially through the axes of the second input shaft 721 and the second output shaft 722 respectively. Each of the second input shaft 721 and the second output shaft 722 is rotatable about the pipe 71.

[0058] The front end portion of the second input shaft 721 is coaxially fixed to the bevel gear 452 of the front-stage speed reduction mechanism 45 and is rotatable integrally with the bevel gear 452. The second motor output shaft 44a rotates forward and backward, and the rotation of the second motor output shaft 44a is decelerated via the bevel pinion 451 and bevel gear 452 of the front-stage speed reduction mechanism 45 and transmitted to the second input shaft 721. The second output shaft 722 is coaxially fixed to the partition wall 521 of the second casing 52, and the second casing 52 can rotate integrally with the second output shaft 722 around the pipe 71. In other words, the base end portion of the second arm 5 is connected to the tip end portion of the first arm 4 via the second speed reduction mechanism 72, and the second arm 5 can swing around the pipe 71.

[0059] The second motor 44 drives the second arm 5 via the second coupling 46, the front-stage speed reduction mechanism 45, and the second speed reduction mechanism 72. Due to the interposition of the front-stage speed reduction mechanism 45 and the second speed reduction mechanism 72, the rotation of the second motor output shaft 44a is decelerated in two stages and transmitted to the second arm 5. The second arm 5 driven by the second motor 44 swings around the pipe 71. The second arm 5 can be stationary in the home position where the longitudinal direction faces up and down (see FIGS. 2 and 3). The tip end portion of the second arm 5 can reciprocate left and right around the home position.

[0060] The inside of the second speed reduction chamber 70 and the second housing 723 is filled with a lubricant. The lubricant is interposed between the bevel pinion 451 and the bevel gear 452, and between the second input shaft 721 and the second output shaft 722. The front-stage casing 42 and the second casing 52 accommodate a plurality of seals. The plurality of seals are each interposed between the front-stage speed reduction mechanism 45 and a member adjacent to the front-stage speed reduction mechanism 45, or between the second speed reduction mechanism 72 and a member adjacent to the second speed reduction mechanism 72, thereby sealing the filled lubricant in a liquid-tight manner. Therefore, it is not necessary to configure the entire first arm 4 and the entire second arm 5 in a liquid-tight manner. The number and arrangement of the seals are not limited.

[0061] In this embodiment, an O-ring 471 is interposed between the rear surface of the partition wall 421 and the front end surface of the second housing 723. An O-ring 472 is interposed between the rear surface of the partition wall 521 and the rear end surface of the second housing 723. An oil seal 473 is interposed between the base end portion of the bevel pinion 451 and the inner peripheral surface of the communication pipe 411.

[0062] The O-rings 471 and 472 can prevent the lubricant filled in the second reduction chamber 70 from leaking out from the rear end opening of the front casing 42 or the front end opening of the second casing 52 along the outer surface of the second housing 723. The oil seal 473 can prevent the lubricant filled in the second reduction chamber 70 from entering the first arm body 41 through the through hole 401 and the communication pipe 411 and leaking out from the front surface opening of the first arm body 41. The O-ring 711 can prevent the lubricant filled in the second reduction chamber 70 from leaking out from the front end opening of the front casing 42 through the through hole 422. The oil seal 712 can prevent the lubricant filled in the second reduction chamber 70 from leaking out from the rear end opening of the front casing 42 through the through hole 522. The O-rings 471, 472, 711 and the oil seals 473, 712 can prevent foreign matter from entering the inside of the second reduction chamber 70 and mixing into the lubricant.

[0063] FIG. 7 is a perspective view of the second arm 5 and the hand casing 6 as viewed from the front side. However, FIG. 7 omits the illustration of the upper part of the second casing 52. Two discharge ports 54 are provided at the tip of the second arm 5. The two discharge ports 54 are adjacent to each other in the front-rear direction and are located at the lower part of the second arm 5 when the second arm 5 is in the home position. The lower part of the lower part of the second arm 5 in the home position is, for example, a portion below the center position of the second arm 5 in the vertical direction. In this embodiment, each discharge port 54 penetrates in the front-rear direction near the lower edge of the second cover plate 53.

[0064] FIG. 8 is a perspective view of the second arm body 51. Six first connectors 55 and four second connectors 56 are provided on the second arm body 51. FIG. 9 is a cross-sectional view near the first connector 55 and the second connector 56 of the second arm main body 51.

[0065] Each first connector 55 is a connector for an air pipe. The first connector 55 penetrates the left side wall of the second arm main body 51 in a liquid-tight manner such that one side portion is located outside the second arm main body 51 and the other side portion is located inside the second arm main body 51. A seal is interposed between the first connector 55 and the left side wall of the second arm main body 51. An air pipe 551 is connected to the outside portion of the first connector 55. An air pipe 552 is connected to the inside portion of the first connector 55. One air pipe 551 and one air pipe 552 are shown respectively.

[0066] Each second connector 56 is a connector for a signal line. The second connector 56 penetrates the right side wall of the second arm main body 51 in a liquid-tight manner such that one side portion is located outside the second arm main body 51 (see FIG. 7) and the other side portion is located inside the second arm main body 51. A seal is interposed between the second connector 56 and the right side wall of the second arm main body 51. A signal line 561 is connected to the outside portion of the second connector 56. A signal line 562 is connected to the other side portion of the second connector 56. One signal line 561 and one signal line 562 are shown respectively.

[0067] The second arm main body 51 houses a cover 57. The cover 57 has a rectangular box shape with one side open. The cover 57 covers the four second connectors 56 in a liquid-tight manner from the inside of the second arm main body 51 such that the open side faces the inner surface of the right side wall of the second arm main body 51. A seal is interposed between the peripheral edge of the opening of the cover 57 and the inner surface of the right side wall of the second arm main body 51. Each signal line 562 penetrates the front wall of the cover 57 in a liquid-tight manner and is arranged from the inside to the outside of the cover 57. In the present embodiment, a cord lock 571 having liquid-proof property penetrates the front wall of the cover 57 in a liquid-tight manner, and the signal line 562 penetrates the cord lock 571 in a liquid-tight manner.

[0068] As shown in FIGS. 2, 3, and 7, the hand casing 6 is integrally provided at the tip of the second arm 5. The tip of the second arm 5 supports the hand casing 6. FIG. 10 is a cross-sectional view of the hand casing 6. As shown in FIGS. 7, 8, and 10, the hand casing 6 has a cylindrical shape with its axial length direction facing forward and backward. As shown in FIGS. 7 and 10, the second cover plate 53 of the second arm 5 covers not only the front opening of the second arm body 51 but also the front end opening of the hand casing 6 in an openable and closable manner. The rear half of the hand casing 6 protrudes rearward from the outer surface of the lower end portion of the second arm body 51.

[0069] As shown in FIG. 10, the hand casing 6 has a partition wall 601. The partition wall 601 is integrally provided on the inner surface of the hand casing 6 and divides the internal space of the hand casing 6 into two parts in the front and rear directions. A through hole 602 that penetrates the partition wall 601 in the front-rear direction is provided at the central portion of the partition wall 601. The hand casing 6 has a disk 61. The disk 61 covers the rear end opening of the hand casing 6 from the rear side. The disk 61 shown in the figure includes a disk body with an opening at the center and a cap that liquid-tightly covers the central opening of the disk body. The space surrounded by the disk 61, the peripheral wall of the hand casing 6, and the partition wall 601 is hereinafter referred to as the hand reduction chamber 62.

[0070] The hand casing 6 houses a hand motor 63 and a hand reduction mechanism 64. The hand motor 63 is a known electric motor having water resistance and oil resistance. The axial length direction of the hand motor output shaft 63a of the hand motor 63 faces forward and backward and is orthogonal to the longitudinal direction of the second arm 5. The main body of the hand motor 63 is located on the front side of the partition wall 601 and is fixed to the hand casing 6 using appropriate fixing tools. The hand motor output shaft 63a penetrates the through hole 602 of the partition wall 601 from the front side.

[0071] The hand reduction mechanism 64 is a known reduction gear, and includes a hand input shaft 641, a hand output shaft 642, and a hand housing 643. The hand input shaft 641 and the hand output shaft 642 are coaxial with each other, and the axial length directions of both face forward and backward. The hand housing 643 is cylindrical, and its axial length direction faces forward and backward. The hand housing 643 houses the hand input shaft 641 and the hand output shaft 642. The front end portion of the hand input shaft 641 is exposed from the front end opening of the hand housing 643, and the rear end portion of the hand output shaft 642 is exposed from the rear end opening of the hand housing 643. The hand housing 643 also houses gears (not shown) for reducing the rotation of the hand input shaft 641 and transmitting it to the hand output shaft 642.

[0072] The hand housing 643 is located in the hand reduction chamber 62. The hand housing 643 is fixed to the hand casing 6 using appropriate fixing tools. The hand input shaft 641 is cylindrical. The hand motor output shaft 63a is inserted inside the hand input shaft 641, and the hand motor output shaft 63a and the hand input shaft 641 are coaxially connected to each other. Since there is no coupling between the hand motor output shaft 63a and the hand input shaft 641, the hand motor 63 and the hand reduction mechanism 64 are closer to each other in the front-rear direction compared to the first motor 31 and the first reduction mechanism 32 (see FIG. 5).

[0073] The hand motor output shaft 63a rotates forward and backward, and the rotation of the hand motor output shaft 63a is transmitted to the hand input shaft 641. The hand output shaft 642 is coaxially fixed to the disk 61. The disk 61 can rotate integrally with the hand output shaft 642 around the hand output shaft 642.

[0074] The inside of the hand housing 643 is filled with a lubricant. The lubricant is interposed between the hand input shaft 641 and the hand output shaft 642. The hand casing 6 houses a plurality of seals. The plurality of seals are each interposed between the hand motor 63 and a member adjacent to the hand motor 63, or between the hand reduction mechanism 64 and a member adjacent to the hand reduction mechanism 64, thereby hermetically sealing the filled lubricant. Therefore, it is not necessary to configure the entire hand casing 6 to be liquid-tight. The number and arrangement of the seals are not limited.

[0075] In the present embodiment, the lubricant can flow out from the front-end opening and the rear-end opening of the hand housing 643 into the hand reduction chamber 62. An O-ring 651 is interposed between the rear surface of the partition wall 601 and the front surface of the hand housing 643. An O-ring 652 is interposed between the hand output shaft 642 and the inner surface of the disk 61. An oil seal 653 is interposed between the hand motor output shaft 63a and the inner peripheral surface of the through-hole 602.

[0076] The O-rings 651 and 652 can prevent the lubricant that has flowed out into the hand reduction chamber 62 from leaking out of the rear-end opening of the hand casing 6. The oil seal 653 can prevent the lubricant that has flowed out into the hand reduction chamber 62 from leaking out of the front-end opening of the hand casing 6 through the through-hole 602. The O-rings 651 and 652 and the oil seal 653 can prevent foreign matter from entering the inside of the hand reduction chamber 62 and mixing into the lubricant.

[0077] FIG. 11 is a perspective view of the second arm 5 and the hand casing 6 as viewed from the rear side. The arm device 132 includes a hand unit 8. FIGS. 2 and 3 omit the illustration of the hand unit 8. The hand casing 6 supports the hand unit 8. The hand unit 8 includes a substrate 81, two drive units 82, and two hands 83 (see FIG. 12 described later).

[0078] The substrate 81 is fixed to the outer surface of the disk 61 of the hand casing 6 such that both sides face forward and backward. The substrate 81 can rotate integrally with the disk 61 about the hand output shaft 642 of the hand reduction mechanism 64. Two extension portions 811 extend outward from the edge of the substrate 81. The extension directions of the two extension portions 811 are perpendicular to each other.

[0079] The two driving portions 82 correspond one-to-one to the two extension portions 811, and the two hands 83 correspond one-to-one to the two driving portions 82. In the following, a set of one of the extension portions 811, the driving portion 82, and the hand 83 will be described, but the set of the other extension portion 811, the driving portion 82, and the hand 83 has the same configuration.

[0080] The driving portion 82 is a known air cylinder having water resistance and oil resistance, and includes two rods 821. The main body of the driving portion 82 is fixed to the extension portion 811 via appropriate fixing tools. The two rods 821 can protrude and retract in opposite directions with respect to the main body of the driving portion 82.

[0081] The hand 83 faces the outer peripheral surface of the rear half portion of the hand casing 6 (the portion protruding rearward from the second arm 5). The hand 83 includes two clamping pieces 831. The two clamping pieces 831 are respectively fixed to the two rods 821 of the driving portion 82, and approach and separate from each other due to the protrusion and retraction of the two rods 821. When the two clamping pieces 831 approaching each other clamp the workpiece W, the hand 83 grips the workpiece W.

[0082] When the substrate 81 rotates together with the disk 61, the hand 83 rotates and moves around the hand output shaft 642 of the hand reduction mechanism 64. FIG. 12 is a perspective view for explaining the rotational movement of the hand 83. As shown in FIGS. 11 and 12, even when the hand 83 rotates and moves, the hand 83 and the outer peripheral surface of the rear half portion of the hand casing 6 always face each other. The hand motor 63 drives the hand 83 via the hand reduction mechanism 64. Due to the intervention of the hand reduction mechanism 64, the rotation of the hand motor output shaft 63a is decelerated and transmitted to the hand 83. The hand 83 driven by the hand motor 63 rotates and moves along the outer peripheral surface of the rear half portion of the hand casing 6.

[0083] Here, the procedure for exchanging the workpiece W by the arm device 132 will be briefly described. One hand 83 grips one workpiece W outside the main body cover 12. The first arm 4 and the second arm 5 convey the one workpiece W gripped by one hand 83 to the inside of the main body cover 12. The other hand 83 grips the other workpiece W placed inside the main body cover 12. One hand 83 places the one workpiece W inside the main body cover 12. The first arm 4 and the second arm 5 convey the other workpiece W gripped by the other hand 83 to the outside of the main body cover 12. In this way, the arm device 132 exchanges the workpiece W.

[0084] Since the second arm 5 is not configured to be liquid-tight, foreign matter may enter the inside of the second arm 5. By returning the second arm 5 to the home position when the workpiece W is not being conveyed, the foreign matter that has entered the inside of the second arm 5 naturally exits from the inside of the second arm 5 through the discharge port 54. Therefore, it is possible to prevent foreign matter from accumulating inside the second arm 5. The discharge port 54 only needs to be located at the tip of the second arm 5 (particularly, the lower part of the second arm 5 when in the home position), so it is not limited to the second cover plate 53 and may be provided, for example, on the peripheral wall of the hand casing 6.

[0085] When foreign matter accumulates inside the second arm 5, the weight of the second arm 5 may increase, which may have an adverse effect on the operation of the second arm 5. Therefore, it is desirable that the discharge port 54 be located at the lower end of the second arm 5 when in the home position. However, since there are no particular problems other than the increase in the weight of the second arm 5, if the increase in weight due to the foreign matter accumulated in the second arm 5 does not have an adverse effect on the operation of the second arm 5, the position of the discharge port 54 is not limited to the lower end of the second arm 5.

[0086] The second arm 5 and the latter half of the hand casing 6 constitute one side and the other side of an L shape. Since the hand 83 rotates around the latter half of the hand casing 6, the space inside the L shape (the space surrounded by the second arm 5 and the latter half of the hand casing 6) can be effectively utilized. Therefore, it is possible to suppress the work W held by the hand 83 from interfering with surrounding objects (for example, members constituting the machine tool 1) during conveyance.

[0087] As shown in FIGS. 2 and 3, the arm device 132 includes a flexible tube 73. The flexible tube 73 is connected to the base end portion of the first arm 4 and the side wall (the rear side wall in this embodiment) of the base 2 outside the first casing 3. The flexible tube 73 includes an I-shaped upper tube 731 and an L-shaped lower tube 732. The upper tube 731 hangs down from the first arm 4, and the lower tube 732 is fixed to the upper tube 731 and the base 2 respectively.

[0088] As shown in FIGS. 3 and 5, a through hole 402 penetrating the wall surface of the first arm 4 is provided at the base end portion of the first arm 4. The upper end portion of the upper tube 731 penetrates through the through hole 402 and is fixed to the first arm 4 such that the upper end opening is located inside the first arm 4. As shown in FIGS. 3 and 4, one end portion of the lower tube 732 is fitted into the opening 24 of the rear side wall of the base 2 such that the opening of the other end portion faces upward. The lower end portion of the upper tube 731 is connected to the other end portion of the lower tube 732. As shown in FIG. 3, the internal space of the base 2 and the internal space of the first arm 4 communicate with each other through the flexible tube 73.

[0089] Since the first arm 4 is not configured to be liquid-tight, foreign matter may enter the inside of the first arm 4. By returning the first arm 4 to the home position when the work W is not being conveyed, the foreign matter that has entered the inside of the first arm 4 naturally exits from the inside of the first arm 4 through the through hole 402 or the flexible tube 73. Therefore, it is possible to suppress the accumulation of foreign matter inside the first arm 4.

[0090] Next, the wiring of the arm device 132 will be described. The signal lines 561 and 562 shown in FIG. 9 are for detecting the operation of the hand 83, for example, and each has water resistance and oil resistance. The signal line 561 extends from a connection terminal for connecting to a detection unit (for example, an encoder provided in the first motor 31, the second motor 44, or the hand motor 63) (not shown), and the tip end portion is liquid-tightly connected to the outer portion of the second connector 56. One end portion of the signal line 562 is connected to the inner portion of the second connector 56. Since there is no risk of foreign matter entering the inside of the cover 57, there is no need to liquid-tightly connect the signal line 562 and the second connector 56, nor is it necessary to liquid-tightly configure the entire second arm 5.

[0091] The signal line 562 is arranged from the inside of the cover 57 to the outside of the cover 57 through the cord lock 571, and goes upward through the inside of the second arm main body 51.

[0092] FIG. 13 is a cross-sectional view of the base 2, the first casing 3, and the base end portion of the first arm 4. FIG. 14 is a cross-sectional view of the first arm 4, the second arm 5, and the hand casing 6. As shown in FIG. 14, the signal line 562 is arranged inside the flexible tube 73 through the inside of the second casing 52, the pipe 71, the front-stage casing 42, and the first arm main body 41 in this order from the inside of the second arm main body 51.

[0093] As shown in FIG. 13, the signal line 562 passes downward inside the flexible tube 73, enters the inside of the base 2 through the opening 24 facing forward, passes through the elastic member 23 upward through the bottom surface opening 212, and is arranged in the accommodation chamber 21. A signal connector 563 is provided at the other end portion of the signal line 562. The accommodation chamber 21 houses the signal connector 563.

[0094] As shown in Fig. 4, the accommodation chamber 21 houses the signal connector 564. The signal connectors 563 and 564 are connected to each other. The signal connector 564 is provided at one end of the signal line 565. The other end of the signal line 565 is connected to the control device 14. The signal line 565 is arranged in the accommodation chamber 21 from the control device 14 through the opening 25 and the elastic member 23. For example, the detection signals for detecting the operation of the hand 83 are transmitted to the control device 14 through the signal lines 561, 562, and 565 in this order.

[0095] For example, the operator puts his hand into the accommodation chamber 21 through the front opening 211 and connects the corresponding connectors to each other. After the connection work is completed, the operator closes the cover plate 22. Since the elastic member 23 covers the lower surface opening 212, there is no risk of foreign matter entering the accommodation chamber 21 through the lower surface opening 212. As shown in Figs. 4 and 13, each of the signal lines 562 and 565 passes through the elastic member 23 and hangs down from the accommodation chamber 21, so there is no risk of foreign matter entering the accommodation chamber 21 along the signal lines 562 and 565. Therefore, there is no need to connect the signal connectors 563 and 564 in a liquid-tight manner, nor is there a need to configure the entire base 2 in a liquid-tight manner.

[0096] There is no risk of the signal lines 562 and 565 being disconnected due to external force from the elastic member 23. If a foreign object having conductivity adheres to the connection portion of the signal connectors 563 and 564, there is a risk of electric leakage.

[0097] The air pipes 551 and 552 shown in Fig. 9 are drive wirings for supplying air to the drive unit 82 to drive the hand 83, for example. The air pipe 551 extends from the drive unit 82 toward the second arm 5. The tip of the air pipe 551 is liquid-tightly connected to the outer side of the first connector 55. One end of the air pipe 552 is connected to the inner side of the first connector 55. The air pipe 552 is arranged inside the flexible tube 73 through the same path as that of the signal line 562 from the inside of the second arm body 51. Note that the air pipes 551 and 552 are not limited to the drive unit 82, and may be for supplying air to an air brake (not shown). The air brake brakes the hand 83.

[0098] As shown in FIG. 13, the air pipe 552 enters the inside of the base 2 through the opening 24 inside the flexible tube 73. Inside the base 2, the other end of the air pipe 552 is connected to one side of the air connector 553. The air connector 553 is a connector for the air pipe, and is attached to, for example, the inner surface of the left side wall of the base 2 and is located below the accommodation chamber 21.

[0099] As shown in FIG. 4, one end of the air pipe 554 is connected to the other side of the air connector 553. The other end of the air pipe 554 is connected to a compressor (not shown) provided in the factory. The air pipe 554 is arranged inside the base 2 through the opening 25. The air pumped by the compressor reaches the drive unit 82 through the air pipes 554, 552, 551 in this order.

[0100] If a solid foreign object is caught between the first connector 55 and the air pipe 552, or between the air connector 553 and the air pipes 552, 554, there may be air leakage. However, it is difficult for solid foreign objects to enter the inside of the second arm 5 or the inside of the base 2. Therefore, it is not necessary to cover the first connector 55 with a cover similar to the cover 57 from the inside of the second arm 5, or to accommodate the air connector 553 in the accommodation chamber 21. Note that the first connector 55 may be covered with a cover similar to the cover 57 from the inside of the second arm 5, and the air connector 553 may be accommodated in the accommodation chamber 21.

[0101] As shown in FIG. 13, a first cable 311 for supplying power from the first motor 31 to the first motor 31 extends. The first cable 311 enters the inside of the base 2 through the inside of the first casing 3 from the inside of the auxiliary case 303, goes around below the accommodation chamber 21, then penetrates the elastic member 23, passes upward through the bottom surface opening 212, and is arranged in the accommodation chamber 21. A power supply connector 312 is provided at the tip of the first cable 311. The accommodation chamber 21 accommodates the power supply connector 312.

[0102] As shown in FIG. 4, the accommodation chamber 21 houses the power supply connector 313. The power supply connectors 312 and 313 are connected to each other. The power supply connector 313 is provided at one end of the first power supply cable 314. The other end of the first power supply cable 314 is connected to a power source (power supply source) (not shown) provided in the machine tool 1. The first power supply cable 314 is arranged in the accommodation chamber 21 from the power source through the opening 25 and the elastic member 23. The power source supplies power to the first motor 31 through the first power supply cable 314 and the first cable 311.

[0103] As shown in FIG. 14, the second cable 441 for supplying power to the second motor 44 is connected to the second motor 44. The second cable 441 is arranged inside the first arm body 41 and inside the flexible tube 73. As shown in FIG. 13, the second cable 441 is arranged in the accommodation chamber 21 through the inside of the flexible tube 73 and the elastic member 23. A power supply connector 442 is provided at the tip of the second cable 441. The accommodation chamber 21 houses the power supply connector 442.

[0104] As shown in FIG. 4, the accommodation chamber 21 houses the power supply connector 443. The power supply connectors 442 and 443 are connected to each other. The power supply connector 443 is provided at one end of the second power supply cable 444. The second power supply cable 444 is wired in the same manner as the first power supply cable 314. The power source supplies power to the second motor 44 through the second power supply cable 444 and the second cable 441.

[0105] As shown in FIG. 14, the twist-resistant cable 631 for supplying power to the hand motor 63 is connected to the hand motor 63. The twist-resistant cable 631 is arranged in the accommodation chamber 21 through the inside of the hand casing 6 and the inside of the flexible tube 73 (see FIG. 13). As shown in FIG. 13, a power supply connector 632 is provided at the tip of the twist-resistant cable 631. The accommodation chamber 21 houses the power supply connector 632.

[0106] As shown in FIG. 4, the accommodation chamber 21 houses the power supply connector 633. The power supply connectors 632 and 633 are connected to each other. The power supply connector 633 is provided at one end of the hand power supply cable 634. The hand power supply cable 634 is wired in the same manner as the first power supply cable 314. The power supply supplies power to the hand motor 63 via the hand power supply cable 634 and the twist-resistant cable 631. The first cable 311, the first power supply cable 314, the second cable 441, the second power supply cable 444, the twist-resistant cable 631, and the hand power supply cable 634 each have water resistance and oil resistance.

[0107] Regarding the power supply connectors 312 and 313, the power supply connectors 442 and 443, the signal connectors 563 and 564, and the power supply connectors 632 and 633, it is desirable that each is supported by a support tool (not shown) fixed to the inner surface of the accommodation chamber 21. It is desirable that the second cable 441, the signal line 562, and the twist-resistant cable 631 are bundled between the elastic member 23 and the opening 24 inside the base 2. For example, a plate-shaped bundling portion extends downward from the lower portion of the support tool 213, and the second cable 441, the signal line 562, and the twist-resistant cable 631 each pass through a through hole provided in the bundling portion.

[0108] Since the first arm 4 and the second arm 5 swing relative to each other, the twist-resistant cable 631 arranged inside both of them may be twisted. However, since the twist-resistant cable 631 is resistant to twisting, the risk of disconnection due to twisting can be reduced. For the same reason, it is also desirable that the air pipe 552 and the signal line 562 each have twist resistance.

[0109] The second arm 5 swings relative to the first casing 3. However, since the anti-twisting cable 631 and the second cable 441 each bypass the first casing 3 and are arranged on the base 2, there is no risk of twisting. Since the first casing 3 and the base 2 do not swing relative to each other, the first cable 311 passing through both of them will not be twisted. As a result, there is no risk of the first cable 311 and the second cable 441 being disconnected due to twisting, and neither the first cable 311 nor the second cable 441 needs to have anti-twisting properties.

[0110] The anti-twisting cable 631 and the second cable 441 are arranged inside the base 2 through the flexible tube 73 outside the first casing 3 from the inside of the first arm 4. Therefore, the flexible tube 73 can protect the portions of the anti-twisting cable 631 and the second cable 441 that pass outside the first casing 3, reducing the risk of disconnection.

[0111] The accommodation chamber 21 provided inside the base 2 houses the power supply connectors 312, 313, the power supply connectors 442, 443, the signal connectors 563, 564, and the power supply connectors 632, 633 (hereinafter referred to as the connectors). Since the connectors are doubly surrounded, it is possible to prevent foreign matter from adhering to the connection portions by the connectors (and thus leakage due to the adhesion of conductive foreign matter).

[0112] Hereinafter, the first cable 311, the first power supply cable 314, the second cable 441, the second power supply cable 444, the anti-twisting cable 631, and the hand power supply cable 634 are each referred to as a wiring member. Since each wiring member passes through the elastic member 23 and hangs down from the accommodation chamber 21, there is no risk of foreign matter entering the accommodation chamber 21 along the wiring member. The wiring members are arranged from the inside to the outside of the base 2 through the openings 24, 25. Since the openings 24, 25 of the base 2 are below the accommodation chamber 21, there is no risk of foreign matter entering the accommodation chamber 21 through the openings 24, 25 of the base 2. As a result, it is not necessary to configure the entire base 2 to be liquid-tight.

[0113] As described above, it is not necessary to configure the entire base 2, the entire first casing 3, the entire first arm 4, the entire second arm 5, and the entire hand casing 6 in a liquid-tight manner. Since members for configuring each part in a liquid-tight manner can be omitted, the number of parts can be reduced, and the transfer device 13 can be made smaller and lighter. Also, each of the first motor 31, the second motor 44, the hand motor 63, the wiring member, the signal lines 561, 562, 565, and the air pipes 551, 552, 554 has water resistance and oil resistance. Therefore, it is not necessary to provide a liquid-proof chamber or a liquid-proof passage for protecting these from foreign matter. Therefore, members for configuring the liquid-proof chamber or the liquid-proof passage can be omitted, and the number of parts can be reduced, and the transfer device 13 can be made smaller and lighter.

[0114] There is no risk that the wiring member will be disconnected due to an external force received from the elastic member 23. Since the base 2 is not configured in a liquid-tight manner, foreign matter may enter the inside of the base 2. Also, foreign matter may enter the inside of the base 2 from the first arm 4 through the flexible tube 73. The foreign matter that has entered the inside of the base 2 naturally exits from the inside of the base 2 through the opening 25. Therefore, it is possible to suppress the accumulation of foreign matter inside the base 2.

[0115] According to the transfer device 13 as described above, the hand casing 6 provided between the hand 83 and the second arm 5 houses the hand motor 63 and the hand reduction mechanism 64. Since the second arm 5 does not house the hand motor 63, the designer of the transfer device 13 can determine the width (length in the front-rear direction) of the second arm 5 and the size of the hand motor 63 independently of each other. That is, the degree of freedom in the design of the transfer device 13 is improved. Since the width of the second arm 5 can be made sufficiently narrow, the size, shape, or orientation of the work W gripped by the hand 83 is not restricted. That is, the degree of freedom of the work W to be transferred is improved.

[0116] Since there is no need to use a small hand motor 63 for the purpose of narrowing the width of the second arm 5, a large hand motor 63 having sufficient output torque can be used. Therefore, there is no need to interpose a plurality of speed reduction mechanisms between the hand motor 63 and the hand 83 to compensate for the shortage of the output torque of the hand motor 63. That is, the size and weight of the transfer device 13 can be reduced and the number of parts can be decreased.

[0117] Since both the first arm 4 and the second arm 5 are lightweight, the torque required to drive the first arm 4 to which the second arm 5 is connected is small. Therefore, there is no need to interpose a plurality of speed reduction mechanisms between the first motor 31 and the first arm 4 to compensate for the shortage of the output torque of the first motor 31. That is, the size and weight of the transfer device 13 can be reduced and the number of parts can be decreased.

[0118] Note that the transfer device 13 is not limited to a workpiece exchange device. The transfer device 13 may transfer an object (for example, a tool) other than the workpiece W.

[0119] The embodiments disclosed this time should be considered as illustrative in all respects and not restrictive. The scope of the present invention is not the above-mentioned meaning, but is intended to include the meaning equivalent to the scope of the claims and all modifications within the scope of the claims.

Explanation of Signs

[0120] 1 Machine tool 13 Transfer device 2 Base 21 Accommodation chamber 3 First casing 31 First motor 31a First motor output shaft 311 First cable 312, 313 Power supply connectors (connectors) 314 First power supply cable (power supply cable) 32 First speed reduction mechanism 321 First input shaft 322 First output shaft 4 First arm (arm) 44 Second motor 441 Second cable 442, 443 Power supply connector (connector) 444 Second power supply cable (power supply cable) 5 Second arm (arm) 6 Casing for hand (casing) 63 Hand motor (motor) 63a Output shaft of hand motor (motor output shaft) 631 Cable with resistance to torsional rotation 632, 633 Power supply connector (connector) 634 Power supply cable for hand (power supply cable) 64 Reduction mechanism for hand (reduction mechanism) 641 Input shaft for hand (input shaft) 642 Output shaft for hand (output shaft) 71 Pipe 73 Flexible tube 83 Hand W Workpiece (object)

Claims

1. A hand that grips an object and is rotatably movable, an arm that conveys the object gripped by the hand, a motor that drives the hand via a speed reduction mechanism, a casing that is supported by the arm and houses the motor and the speed reduction mechanism and is provided with, the speed reduction mechanism has an input shaft coaxially connected to the motor output shaft of the motor, and an output shaft for reducing and transmitting the rotation of the input shaft to the hand and has, the axial length direction of the motor output shaft is orthogonal to the longitudinal direction of the arm, a part of the casing protrudes from the outer surface of the arm to one side in the axial length direction, the hand rotates and moves around the output shaft so as to face the outer peripheral surface of the part of the casing, and a conveying device characterized by this.

2. The arm has a first arm that can swing, and a second arm whose tip supports the casing and whose base end is connected to the tip of the first arm and can swing and has, further includes a first motor that drives the first arm via a first speed reduction mechanism, the first speed reduction mechanism has a first input shaft coaxially connected to the first motor output shaft of the first motor, and a first output shaft for reducing and transmitting the rotation of the first input shaft to the first arm and has, the first arm swings around the first output shaft, and the conveying device according to claim 1, characterized by this.

3. a pipe spanning the tip of the first arm and the base end of the second arm, a second motor that drives the second arm, a hollow base that supports the first arm, a first casing provided between the base and the base end of the first arm and housing the first motor and the first speed reduction mechanism, a twist-resistant flexible cable for supplying power to the motor, a first cable for supplying power to the first motor, a second cable for supplying power to the second motor, and further includes connectors for connecting the twist-resistant flexible cable, the first cable, and each of the second cables to a power supply cable extending from a power source and is provided with, the second arm swings around the pipe, each of the first arm and the second arm is hollow, the first arm houses the second motor, the twist-resistant flexible cable is arranged inside the base through the inside of the casing, the inside of the second arm, the inside of the pipe, the inside of the first arm, and the outside of the first casing. The second cable is disposed inside the base through the outside of the first casing from the inside of the first arm. The first cable is disposed inside the base from the inside of the first casing. The conveying device according to claim 2, wherein the connector is disposed inside the base.

4. The base end portion of the first arm is located below the tip end portion of the first arm. The conveying device according to claim 3, further comprising a flexible tube that connects the base end portion of the first arm and the side wall of the base outside the first casing and through which the anti-twisting cable and the second cable pass.

5. The conveying device according to claim 3 or 4, further comprising a housing chamber provided inside the base and housing the connector.

6. A machine tool comprising the conveying device according to any one of claims 1 to 5. The machine tool is characterized by processing a workpiece conveyed by the conveying device.

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