Transfer device

Abstract

A transfer device (1) comprises: a workpiece-holding part (11); a first supporting part (12) that rotatably supports the workpiece-holding part (11); a reference orientation return mechanism (14) which, when a first external force in a rotational direction is applied to the workpiece-holding part (11) and the workpiece-holding part (11) has thereby rotated from a reference orientation with respect to the first supporting part (12), biases the workpiece-holding part (11) in a direction in which the workpiece-holding part (11) returns to the reference orientation; a second supporting part (15) that supports the first supporting part (12) movably in directions orthogonal to the vertical direction; and a reference position return mechanism (13) which, when a second external force in a direction orthogonal to the vertical direction is applied to the first supporting part (12) and the first supporting part (12) has thereby moved from a reference position with respect to the second supporting part (15) in a direction orthogonal to the vertical direction, biases the first supporting part (12) in a direction in which the first supporting part (12) returns to the reference position.

Description

Transfer equipment

[0001] The present invention relates to a transfer device.

[0002] A machining system has been proposed that includes two base units, two work machine modules mounted on each of the two base units in a unidirectional arrangement, and a conveying device unit that transports workpieces from one of the two work machine modules to the other (see, for example, Patent Document 1).

[0003] International Publication No. 2015 / 037147

[0004] In the system described in Patent Document 1, there is a demand for increasing the degree of freedom in the arrangement of the work machine modules by using an automated guided vehicle instead of a conveyance device unit. In this case, there is a demand for smooth and appropriate transfer of workpieces from the automated guided vehicle to the work machine modules.

[0005] The present invention has been made in view of the above-mentioned circumstances, and has an object to provide a transfer device that can appropriately transfer a workpiece.

[0006] In order to achieve the above-mentioned object, the transfer device of the present invention comprises: a work holding section that holds a work; a first support section that supports the work holding section so that it can rotate freely in a rotational direction around a predetermined rotation axis; a reference position return mechanism that urges the work holding section in a direction returning to the reference position when a first external force is applied to the work holding section in the direction of rotation around the rotation axis, causing the work holding section to rotate from a predetermined reference position relative to the first support section in the rotational direction about the rotation axis; a second support section that supports the first support section so that it can move freely in a second direction perpendicular to a first direction along the rotation axis; and a reference position return mechanism that urges the first support section in a direction returning to the reference position when a second external force is applied to the first support section in the second direction, causing the first support section to move from a predetermined reference position relative to the second support section in the second direction.

[0007] According to the present invention, the first support portion supports the workpiece holding portion rotatably in a direction rotating about the rotation axis, and the second support portion supports the first support portion, which supports the workpiece holding portion, movably in a direction perpendicular to a first direction along the rotation axis. Meanwhile, the reference attitude return mechanism urges the workpiece holding portion in a direction returning to the reference attitude when the workpiece holding portion rotates from the reference attitude relative to the first support portion in the rotation direction about the rotation axis, and the reference position return mechanism urges the first support portion in a direction returning to the reference position when the first support portion moves from the reference position relative to the second support portion in a direction perpendicular to the first direction. As a result, when transferring the workpiece to a jig used in, for example, a machine tool, even if there is a relative positional deviation between the workpiece and the jig, the positional deviation is absorbed by the workpiece holding portion rotating relative to the first support portion or the first support portion moving relative to the second support portion, so that the workpiece can be smoothly transferred to the jig. Furthermore, when the workpiece holder is released from the workpiece, the reference posture return mechanism and the reference position return mechanism can automatically return the workpiece holder to the reference posture and reference position, making it easy to position the workpiece on the workpiece holder the next time it is placed on the workpiece holder. This allows the workpiece to be transferred from the workpiece holder to the jig and placed on the workpiece holder in an appropriate manner.

[0008] 1 is a schematic side view showing an unmanned transport device and a machine tool equipped with a transfer device according to a first embodiment of the present invention. FIG. 1 is a schematic perspective view of a workpiece and a jig according to the first embodiment. FIG. 2 is a schematic cross-sectional view of the transfer device according to the first embodiment. FIG. 3 is a cross-sectional view of a part of the transfer device according to the first embodiment. FIG. 4 is a schematic plan view of a part of the transfer device according to the first embodiment. FIG. 5 is a schematic plan view of a part of the transfer device according to the first embodiment. FIG. 6 is a cross-sectional view of a part of the transfer device of the transfer device according to the first embodiment. FIG. 7 is a schematic side view showing an unmanned transport device and a machine tool equipped with a transfer device according to the first embodiment. FIG. 8 is a schematic side view showing an unmanned transport device and a machine tool equipped with a transfer device according to the first embodiment. FIG. 9 is a schematic perspective view showing an unmanned transport device and a staging platform equipped with a transfer device according to a second embodiment. FIG. 10 is a schematic plan view showing an unmanned transport device and a staging platform equipped with a transfer device according to the second embodiment. 1 is a schematic perspective view of an unmanned transport device equipped with a transfer device according to embodiment 2. FIG. 1 is a schematic perspective view of a transfer device according to embodiment 2. FIG. 2 is a schematic side view of a transfer device according to embodiment 2. FIG. 3 is a schematic cross-sectional view of a part of a transfer device according to embodiment 2. FIG. 4 is a schematic cross-sectional view of a part of a transfer device according to embodiment 2. FIG. 5 is a schematic cross-sectional view of a part of a transfer device according to embodiment 2. FIG. 6 is a schematic plan view showing an unmanned transport device equipped with a transfer device according to embodiment 2 and a relay platform. FIG. 7 is a schematic cross-sectional view of a part of a transfer device according to a modified example. FIG. 8 is a schematic cross-sectional view of a part of a transfer device according to a modified example. FIG. 9 is a schematic cross-sectional view of a part of a transfer device according to a modified example.

[0009] (Embodiment 1) A transfer device according to an embodiment of the present invention will be described below with reference to the drawings. The transfer device according to this embodiment includes a workpiece holding unit that holds a workpiece, a first support unit that supports the workpiece holding unit so that it can rotate freely in a rotational direction about a predetermined rotation axis, a reference position return mechanism that urges the workpiece holding unit in a direction returning to the reference position when a first external force is applied to the workpiece holding unit in the rotational direction about the rotation axis, causing the workpiece holding unit to rotate from a predetermined reference position relative to the first support unit in the rotational direction about the rotation axis, a second support unit that supports the first support unit so that it can move in a direction perpendicular to the first direction along the rotation axis, and a reference position return mechanism that urges the first support unit in a direction returning to the reference position when a second external force is applied to the first support unit in the direction perpendicular to the first direction, causing the first support unit to move from a predetermined reference position relative to the second support unit in the direction perpendicular to the first direction.

[0010] 1, for example, a transfer device 1 according to this embodiment is attached to an automated guided vehicle (hereinafter referred to as "AGV") 2 that transports a workpiece W1 to a machine tool 3. The AGV 2 includes an AGV main body 21 having a traveling function, and a long, plate-shaped arm 23 having a through-hole 23a penetrating through its thickness at one end in the longitudinal direction. The AGV 2 also includes a long shaft 22 that supports the other end of the arm 23 in the longitudinal direction at one end in the longitudinal direction, i.e., the end on the +Z direction, and an elevation drive unit 24 mounted on the AGV main body 21 and elevating the shaft 22. The transfer device 1 is fixed to the arm 23 in such a way that a portion of a workpiece holding unit 11 (described later) of the transfer device 1 is inserted inside the through-hole 23a.

[0011] The machine tool 3 is, for example, a honing device that cuts a workpiece W1 and includes a stage 31, a head 33 equipped with a spindle, and a support column 32 that is erected on the stage 31 and supports the head 33. A jig JI1 for holding the workpiece W1 to be machined by the machine tool 3 is placed on the vertically upper side of the stage 31, i.e., on the +Z direction side. As shown in FIG. 2 , the jig JI1 is a rectangular plate with a groove JI12 extending along the Y-axis direction on the +Z direction side of the jig JI1. Four protrusions JI11 for positioning the workpiece W1 are provided on both sides of the groove JI12 in the X-axis direction on the +Z direction side of the +Z direction side, jutting out along the Y-axis direction. A holding piece 112 of a workpiece holding unit 11 (described later) of the transfer device 1 can be inserted into the groove J12 from the +Z direction side and then removed from the -Y direction side.

[0012] On the other hand, the workpiece W1 is formed with a recess De1 that can fit onto the protrusion JI11 of the jig JI1, and a recess De2 that can fit onto the protrusion 112a provided on the workpiece holding portion 11 of the transfer device 1. Here, as shown by the four dashed arrows in Fig. 2, the workpiece W1 can be moved toward the jig JI1 from the +Z direction side of the jig JI1, and placed on the +Z direction side of the jig JI1 with the four protrusions JI11 of the jig JI1 fitted inside each of the four recesses De1.

[0013] 3, the transfer device 1 includes a workpiece holding unit 11 that holds the workpiece W1, a first support unit 12 that supports the workpiece holding unit 11 so as to be rotatable in a rotational direction around a rotation axis J1 that is aligned with a predetermined vertical direction, as indicated by an arrow AR11, a reference attitude return mechanism 14, a second support unit 15 that supports the first support unit 12 so as to be movably in a direction perpendicular to the first direction along the rotation axis J1, i.e., in the XY directions, as indicated by an arrow AR12, and a reference position return mechanism 13. The workpiece holding unit 11 includes a cylindrical holding unit main body 111, a long, plate-like holding piece 112 that holds the workpiece W1, and an arm 113 that has a base end fixed to one end of the holding unit main body 111 in the column axis direction, i.e., the end on the -Z direction side, and a holding piece provided at a tip end thereof. In addition, the workpiece holding portion 11 is disk-shaped and has recesses 114a at two locations in the circumferential direction that are approximately wedge-shaped when viewed from the direction of the rotation axis J1, and has a disk-shaped portion 114 at the other end in the column axis direction of the holding portion main body 111, i.e., the end on the +Z direction side, so that the central axis along the thickness direction coincides with the column axis of the holding portion main body 111.

[0014] The first support part 12 has a support part main body 121 that is plate-shaped and has a through hole 121a that is circular in plan view and penetrates through the thickness direction, and a bearing 122 that is fitted into the through hole 121a of the support part main body 121 and fixed to the support part main body 121 to rotatably support the holder part main body 111 arranged inside. The bearing 122 has an outer ring 1221 that is annular and fixed to the support part main body 121 while being fitted into the through hole 121a, an inner ring 1222 that is annular and fixed to the holder part main body 111 that is fitted inside, rolling elements 1223 that roll between the outer ring 1221 and the inner ring 1222, and a cage (not shown) that holds the rolling elements 1223.

[0015] 4A and 4B , the reference attitude return mechanism 14 has a roller 141 that abuts against the inside of the recess 114a from the outside in the radial direction of the disc-shaped portion 114 of the workpiece holding part 11, a roller support part 142 that supports the roller 141, and a roller biasing part 143 that biases the roller 141 toward the center of the disc-shaped portion 114. The roller support part 142 has a support part main body 1421 that is L-shaped in a plan view, a shaft part 1422 that is provided at one end of the support part main body 1421 in the extension direction and is fixed to the first support part 12 to rotatably support the support part main body 1421, and a shaft part 1423 that is provided at the other end of the support part main body 1421 and rotatably supports the roller 141. The roller biasing portion 143 includes a biasing member 1431 having one end fixed to the support portion main body 1421 and a fixed portion 1432 protruding from the periphery of the support portion main body 121 of the first support portion 12 and having the other end of the biasing member 1431 fixed thereto. The biasing member 1431 is, for example, a coil spring. The biasing member 1431 may also be an air cylinder, an elastic member such as rubber, or the like. When an external force is applied to the workpiece holder 11 in the direction of rotation about the rotation axis J1, the reference posture return mechanism 14 rotates the workpiece holder 11 relative to the first support portion 12 from a preset reference posture as shown in FIG. 4A in the rotation direction about the rotation axis J1. At this time, the roller 141 moves along the inner inclined surface 114b of the recess 114a of the disk-shaped portion 114, as shown in FIG. 4B , due to the restoring force of the biasing member 1431, a biasing force in the direction indicated by arrow AR21 is generated on the roller 141. This biasing force generates a force in the disk-shaped portion 114 that rotates it in the direction of returning it to the basic position as shown by arrow AR22, and the workpiece holding portion 11 is biased in the direction of returning it to the reference position shown in Figure 4A.

[0016] 3 , the second support portion 15 has a plate-shaped support portion body 151 with a through hole 151a penetrating through it in the thickness direction, and the second support portion 15 has a support portion body 151 into which the holder body 111 of the workpiece holder 11 is inserted, a plurality of rolling elements 152 interposed between the support portion body 151 and the first support portion 12, and a cage 153 that holds the plurality of rolling elements 152. The second support portion 15 supports the first support portion 12 on its surface facing the first support portion 12, i.e., on the +Z direction side, via the rolling elements 152 so that the first support portion 12 can move freely in the X and Y directions. The support portion body 151 is fixed to the arm 23 of the AGV 2 so that the through hole 151a and a through hole 23a formed in the arm 23 are aligned in the Z axis direction.

[0017] The reference position return mechanism 13 biases the first support part 12 in a direction returning to the reference position when a second external force in the XY directions is applied to the first support part 12, causing the first support part 12 to move in the XY directions from a preset reference position relative to the second support part 15. As shown in Fig. 5A , the reference position return mechanism 13 has a pressing unit 1321 that presses the first support part 12 in the -X direction as indicated by arrow AR11 from the +X direction side of the first support part 12, and a pressing unit 1322 that presses the first support part 12 in the +X direction as indicated by arrow AR12 from the -X direction side of the first support part 12. The reference position return mechanism 13 also includes a pressing unit 1323 that presses the first support 12 in the -Y direction from the +Y direction side of the first support 12 as indicated by arrow AR13, and a pressing unit 1324 that presses the first support 12 in the +Y direction from the -Y direction side of the first support 12 as indicated by arrow AR14. The pressing unit 1321 includes a slider 13211 that abuts against the +X direction side of the support body 121 of the first support 12 and is movable in the X-axis direction, a biasing member 13213, and a fixed portion 13212 that protrudes from the periphery of the support body 151 of the second support 15 and to which the biasing member 13213 is fixed on the -X direction side. The biasing member 13213 is, for example, a coil spring. The biasing member 13213 may also be an air cylinder, an elastic member such as rubber, or the like. The biasing member 13213 and the fixed portion 13212 constitute a slider biasing portion that biases the slider 13211 in the +X direction. The pressing unit 1322 has a slider 13221 that abuts on the -X direction side of the support portion main body 121 of the first support portion 12 and is movable in the X axis direction, a biasing member 13223, and a fixed portion 13222 that protrudes from the periphery of the support portion main body 151 of the second support portion 15 and has the biasing member 13223 fixed to the +X direction side. The biasing member 13223 and the fixed portion 13222 constitute a slider biasing portion that biases the slider 13221 in the -X direction. The pressing unit 1323 has a slider 13231 that abuts against the +Y side of the support body 121 of the first support part 12 and is freely movable in the Y-axis direction, a biasing member 13233, and a fixed part 13232 that protrudes from the periphery of the support body 151 of the second support part 15 and has the biasing member 13233 fixed to its -Y side.The biasing member 13233 and the fixed portion 13232 constitute a slider biasing portion that biases the slider 13231 in the -Y direction. The pressing unit 1324 has a slider 13241 that abuts against the -Y direction side of the support portion main body 121 of the first support portion 12 and is movable in the Y axis direction, a biasing member 13243, and a fixed portion 13242 that protrudes from the periphery of the support portion main body 151 of the second support portion 15 and has the biasing member 13243 fixed to its +Y direction side. The biasing member 13243 and the fixed portion 13242 constitute a slider biasing portion that biases the slider 13241 in the +Y direction.

[0018] Furthermore, the pressing units 1321 and 1323 have pressing restriction portions 13214 and 13234 that restrict the pressing of the first support portion 12 by the pressing units 1321 and 1323, respectively, when the first support portion 12 is positioned at a preset reference position. The pressing restriction portions 13214 and 13234 are pin-shaped members fixed to the support portion main body 151, and abut against a portion of the slider 13211 when the first support portion 12 is positioned at the reference position, thereby restricting movement of the slider 13211 in the X-axis and Y-axis directions. The pressing units 1322 and 1324 have movement restriction portions 13224 and 13244 that are pin-shaped members fixed to the support portion main body 151, and abut against a portion of the slider 13221 and 13241, thereby restricting movement of the sliders 13221 and 13241 in the X-axis and Y-axis directions.

[0019] 5A , when the first support portion 12 is located at the reference position, the sliders 13211, 13221, 13231, and 13241 are all in contact with the first support portion 12. The pressure restricting portions 13214 and 13234 are in contact with portions of the sliders 13211 and 13231, respectively, restricting their movement in the X-axis and Y-axis directions. Since the biasing force F31 of the biasing member 13213 is set to be greater than the biasing force F32 of the biasing member 13233, the pressure restricting portion 13214 is maintained in contact with a portion of the slider 13211. Furthermore, since the biasing force F33 of the biasing member 13233 is set to be greater than the biasing force F34 of the biasing member 13243, the pressure restricting portion 13234 is maintained in contact with a portion of the slider 13231.

[0020] Now, suppose an external force in the -Y direction is applied to the first support portion 12, causing the first support portion 12 to deviate from the reference position toward the -Y direction. In this case, as shown in FIG. 5B , the slider 13241 is pressed toward the -Y direction by the first support portion 12, compressing the biasing member 13243. Meanwhile, a gap G1 is formed between the slider 13231 and the first support portion 12. Then, when the external force applied to the first support portion 12 is released, the first support portion 12 moves toward the +Y direction due to the restoring force F44 of the biasing member 13243 and returns to the reference position. Meanwhile, suppose an external force in the +Y direction is applied to the first support portion 12, causing the first support portion 12 to deviate from the reference position toward the +Y direction. In this case, as shown in FIG. 6 , the slider 13231 is pressed toward the +Y direction by the first support portion 12, compressing the biasing member 13233. At this time, the slider 13231 is released from the pressure regulating portion 13234. When the external force applied to the first support portion 12 is released, the first support portion 12 moves in the −Y direction due to a force (F33−F34) equivalent to the difference between the restoring force F53 of the biasing member 13233 and the restoring force F54 of the biasing member 13243, and returns to the reference position again.

[0021] Next, an operation of the AGV 2 equipped with the transfer device 1 according to this embodiment to transfer the workpiece W1 to the jig JI1 placed on the stage 31 of the machine tool 3 will be described. As shown in FIG. 1 , the AGV 2 holds the workpiece W1 with the recess De2 of the workpiece W1 fitted into the protrusion 112a of the holding piece 112 of the workpiece holding unit 11 of the transfer device 1, and moves close to the machine tool 3 that processes the workpiece W1. Next, as shown by arrow AR61 in FIG. 7A , the AGV 2 lowers the arm 23 to insert the holding piece 112 of the transfer device 1 into the groove JI12 of the jig JI1 and abut both ends of the workpiece W1 in the X-axis direction against both ends of the groove JI12 on the +Z-direction side of the jig JI1 in the X-axis direction. At this time, as shown by the dashed arrow in FIG. 2 , the protrusion JI11 protruding from the jig JI1 is fitted into the recess De11 drilled in the workpiece W1. Here, as shown in FIG. 8A , the relative position of the workpiece W1 with respect to the jig JI1 may be misaligned in the XY directions, or as shown in FIG. 8B , the relative position of the workpiece W1 with respect to the jig JI1 may be misaligned in both the rotational direction and the XY directions. In contrast, in the transfer device 1 according to this embodiment, as described above, the first support portion 12 supports the workpiece holding portion 11 so as to be rotatable in the direction of rotation about the rotation axis J1, and the second support portion 15 supports the first support portion 12, which supports the workpiece holding portion 11, so as to be movable in the XY directions. As a result, even if there is a relative positional misalignment between the workpiece W1 and the jig JI1 as shown in FIGS. 8A and 8B , when the workpiece W1 is brought into contact with the jig JI1, the workpiece holding portion 11 rotates relative to the first support portion 12, or the first support portion 12 moves relative to the second support portion 15, when the protrusion JI11 of the jig JI1 fits into the recess De1 of the workpiece W1, thereby absorbing the positional misalignment. Next, as shown by arrow AR62 in Fig. 7B, the AGV2 further lowers the arm 23 toward the bottom side of the groove J12 of the jig JI1, thereby pulling out the protrusion 122a provided on the holding piece 112 of the transfer device 1 from the recess De2 of the workpiece W1. Thereafter, as shown by arrow AR63 in Fig. 9, the AGV2 separates from the machine tool 3 while maintaining the position of the holding piece 112, thereby completing the transfer of the workpiece W1 to the jig JI1.

[0022] As described above, according to the transfer device 1 of this embodiment, the first support portion 12 supports the workpiece holding portion 11 so as to be rotatable in a direction rotating about the rotation axis J1, and the second support portion 15 supports the first support portion 12, which supports the workpiece holding portion 11, so as to be movable in the X and Y directions. Meanwhile, the reference attitude return mechanism 14 urges the workpiece holding portion 11 in a direction returning to the reference attitude when the workpiece holding portion 11 rotates from the reference attitude in the rotation direction about the rotation axis J1 relative to the first support portion 12, and the reference position return mechanism 13 urges the first support portion 12 in a direction returning to the reference position when the first support portion 12 moves in the X and Y directions from the reference position relative to the second support portion 15. As a result, even if there is a relative positional misalignment between the workpiece W1 and the jig JI1 when transferring the workpiece W1 to, for example, the jig JI1 used in the machine tool 3, the workpiece holding unit 11 rotates relative to the first support unit 12, and the first support unit 12 moves relative to the second support unit 15, thereby absorbing the positional misalignment between them, and the workpiece W1 can be smoothly transferred to the jig JI1. Furthermore, when the workpiece holding unit 11 is detached from the workpiece W1, the reference attitude return mechanism 14 and the reference position return mechanism 13 can automatically return the workpiece holding unit 11 to the reference attitude and reference position, thereby facilitating positioning of the workpiece W1 in the workpiece holding unit 11 the next time the workpiece W1 is placed on the workpiece holding unit 11. Therefore, the workpiece W1 can be appropriately transferred from the workpiece holding unit 11 to the jig JI1 and placed on the workpiece holding unit 11.

[0023] (Embodiment 2) A transfer device according to this embodiment differs from Embodiment 1 in the structures of the workpiece holding unit, first support unit, reference attitude return mechanism, and reference position return mechanism. For example, as shown in FIG. 10 , a transfer device 2001 according to this embodiment is attached to an AGV 2002 that transports multiple workpieces W2 to a station 2003 where the workpieces W2 are temporarily placed. As shown in FIGS. 11 and 12 , the AGV 2002 includes an AGV main body 2021 having a traveling function and an elevating unit 2022 that has the function of raising and lowering the transfer device 2001 holding the workpieces W2 together with the workpieces W2. The elevating unit 2022 includes a substantially rectangular box-shaped housing 2229 with one side open on the +Z direction side, a frame 2221, four rails 2223, four sliders 2222, and an elevating drive unit (not shown) housed in the housing 2229 that raises and lowers the transfer device 2001. The frame 2221 is disposed inside a housing 2229, and the transfer device 2001 is fixed thereto. Four rails 2223 are disposed inside two side walls of the housing 2229 facing each other in the X-axis direction, two of each rail extending along the lifting direction of the transfer device 2001. Four sliders 2222 are fixed to the frame 2221 and supported on the four rails 2223 so as to be movable along the rails 2223, respectively. As shown in FIG. 12 , the lifting unit 2022 has a rectangular plate-like shape and includes a cover 2228 that covers the +Z direction side of the housing 2229 and has a long slit 2228a formed therein, into which a portion of a workpiece holding unit 2011 (described later) of the transfer device 1 extending along the Y-axis direction is inserted.

[0024] 10 and 11 , the station 2003 includes a station main body 2031 that is U-shaped in plan view, and a top plate 2032 attached to the station main body 2031 so as to cover the +Z direction side of the station main body 2031. A long slit 2032a is formed in the top plate 2032, extending along the direction in which the AGV 2002 enters the inside of the station main body 2031. A pair of long guide plates 2033 that guide the AGV 2002 is disposed on both sides of the inside of the slit 2032a in the short direction. The pair of guide plates 2033 includes long main pieces 2331 that are arranged approximately parallel to each other and sandwich the inside of the slit 2032a, and inclined pieces 2332 that are continuous with one end of the main piece 2331 in the longitudinal direction and inclined so as to move away from each other toward the +Y direction.

[0025] 13 and 14 , the transfer device 2001 includes a workpiece holding unit 2011 that holds a plurality of workpieces W2 (four in FIGS. 13 and 14 ), a first support unit 2012 that supports the workpiece holding unit 2011 rotatably in a rotational direction about a rotation axis J2 that is aligned with a predetermined vertical direction, a reference attitude return mechanism 2014, a second support unit 2015 that supports the first support unit 2012 movably in directions orthogonal to a first direction along the rotation axis J2, i.e., in the X and Y directions, and a reference position return mechanism 2013. The transfer device 2001 also includes a base main body 2161 that is fixed to a frame 2221 of a lifting unit 2022 of the AGV 2002, and a base member 2016 that has a protrusion 2162 that is fixed to the base main body 2161 and that restricts movement of the first support unit 2012 in the X-axis direction relative to the base main body 2161.

[0026] The workpiece holding unit 2011 has a long, rectangular pillar-shaped holding unit main body 2115, a long holding base 2111 that holds a plurality of workpieces W2 together, and a pillar-shaped support 2112. The support 2112 has a base end fixed to the holding unit main body 2115 at one end in the longitudinal direction of the holding unit main body 2115, i.e., at a position shifted toward the other end, i.e., toward the +Y direction, from the end on the -Y direction side, and supports the holding base 2111 at its tip. The workpiece holding unit 2011 also has two rollers 2113 that are arranged side by side in the X-axis direction with their rotation axes aligned along the Z-axis direction. The two rollers 2113 are rotatably supported by a roller support portion 2114 having two support pieces 2114a, 2114b extending in the -Y direction from the end of the holding base 2111 on the -Y direction side, and two shaft portions 2114c which are long and cylindrical and have both ends in the longitudinal direction supported by the two support pieces 2114a, 2114b, and which pivotally support each of the two rollers 2113.

[0027] 14 and 15A, the first support portion 2012 includes a plate-shaped support portion main body 2121 and a shaft portion 2123 that supports the end portion of the holder body 2115 of the workpiece holder 2011 on the workpiece holder 2011 side in the thickness direction of the support portion main body 2121, i.e., the +Z direction side, so that the end portion is rotatable (pivotable) around the rotation axis J2. The support portion main body 2121 includes a plate-shaped main portion 2121a having an opening 2121c that is generally rectangular in plan view and penetrates the thickness direction at its approximate center, and an extension portion 2121b that is generally semicircular in plan view and extends in the −Y direction from the center in the X-axis direction of the end portion of the −Y direction of the main portion 2121a. The shaft portion 2123 is fixed to the +Z direction side of the extension portion 2121b. Furthermore, on the +Z direction side of the support body 2121, a rotation restriction pin 2125 for restricting the rotation range of the holder body 2115 of the workpiece holder 2011 is protruded from each of the outer peripheries of the opening 2121c near both ends in the X axis direction of the end of the opening 2121c on the +Y direction side of the opening 2121c. Furthermore, the tip of the protrusion 2162 of the base member 2016 is inserted into the inside of the opening 2121c of the support body 2121, restricting the movement range of the first support part 2012 in the X axis direction relative to the base member 2016. Furthermore, the first support part 2012 has two ribs 2126 that protrude from the support body 2121 on the side opposite to the workpiece holder 2011 side in the thickness direction of the support body 2121, i.e., on the -Z direction side.

[0028] 15A and 15B , the reference attitude return mechanism 2014 has a pressing unit 2141 that presses the holder body 2115 of the workpiece holder 2011 in the −X direction from a side of the holder body 2115 in a direction perpendicular to the thickness direction of the support body 2121, i.e., from the +X direction side, and a pressing unit 2142 that presses the holder body 2115 in the +X direction from the −X direction side of the holder body 2115. The pressing unit 2141 has a unit body 21411 that is flat and rectangular in a plan view, two pins 21412 whose tip ends abut against the lateral sides of the holder body 2115 on the +X direction side and are movable in the X-axis direction, and two biasing members 21413. The pin 21412 is elongated and has an elongated portion 21412a whose tip end abuts against the holder main body 2115, and a base end 21412b whose outer diameter is larger than that of the elongated portion 21412a. The unit main body 21411 has a first portion 21411a extending along the X-axis direction and having two grooves 21411b formed therein that accommodate the base end 21412b of the pin 21412 and the biasing member 21423, and a second portion 21411c extending along the X-axis direction and having two grooves (not shown) formed therein that accommodate the elongated portion 21412a of the pin 21412 and communicate with the grooves 21411b, respectively. The biasing member 21413 is housed inside the groove 21411b with one end abutting the base end 21412b of the pin 21412, and biases the pin 21412 in the -X direction. The biasing member 21413 is, for example, a coil spring. Note that the biasing member 21413 may also be an air cylinder, an elastic member such as rubber, or the like. The pressing unit 2142 includes a flat unit main body 21421 that is rectangular in plan view, two pins 21422 whose tip ends abut the sides of the holder main body 2115 on the -X direction side and are movable in the X-axis direction, and two biasing members 21423. The pins 21422 are elongated and have an elongated portion 21422a whose tip end abuts the holder main body 2115, and a base end 21422b whose outer diameter is larger than the outer diameter of the elongated portion 21422a.The unit main body 21421 has a first portion 21421a extending along the X-axis direction and having two grooves 21421b formed therein that accommodate the base end 21422b of the pin 21422 and the biasing member 21423, and a second portion 21421c extending along the X-axis direction and having two grooves (not shown) formed therein that accommodate the elongated portion 21422a of the pin 21422 and communicate with the grooves 21421b. The biasing member 21423 is housed inside the grooves 21421b with one end abutting the base end 21422b of the pin 21422 and biases the pin 21422 in the +X direction. The biasing member 21423 is also, for example, a coil spring.

[0029] Here, when the holder main body 2115 of the workpiece holder 2011 is located at the reference position as shown in FIG. 15A , all of the tip ends of the pins 21412 and 21422 are in contact with the holder main body 2115. Now, as shown by arrow AR221 in FIG. 15B , assume that an external force is applied in a direction that rotates the workpiece holder 2011, causing the holder main body 2115 to shift from the reference position in a direction that rotates around the shaft 2123. In this case, the two pins 21422 are each pressed in the −X direction by the holder main body 2115, and the biasing members 21423 that are in contact with the base ends 21422b of the two pins 21422 are compressed. At this time, the restoring force of the biasing members 21423 causes the two pins 21422 to press the holder main body 2115 in the direction shown by arrow AR222. Furthermore, a gap is formed between each of the two pins 21421 and the holder body 2115. When the external force applied to the workpiece holder 2011 is released, the holder body 2115 is pressed by the two pins 21422 and moves in the +Y direction, returning to the reference position.

[0030] As shown in Fig. 14, the second support portion 2015 is disposed opposite the -Z direction side of the support portion main body 2121 of the first support portion 2012. As shown in Figs. 16A and 16B, the second support portion 2015 has a rectangular plate-shaped support portion main body 2151 having an opening 2151a that is generally rectangular in plan view and penetrates through its center, two rails 2152 extending along the X axis direction at both ends of the support portion main body 2151 in the Y axis direction, and four sliders 2153 supported on each of the two rails 2152 so as to be movably movable along the rails 2152. The four sliders 2153 are each fixed to the support portion main body 2121 of the first support portion 2012 and supported on the rails 2152 via rolling elements (not shown). Here, when the second support part 2015 supports the first support part 2012 via the rail 2152 and the slider 2153, the tip of the rib 2126 of the first support part 2012 is spaced apart from one surface on the +Z direction side of the support part main body 2151.

[0031] The reference position return mechanism 2013 has two pressing units 2134 that press each of the two ribs 2126 in the −X direction from the side of each of the two ribs 2126 in a direction perpendicular to the thickness direction of the support portion main body 2121, i.e., the +X direction side, and two pressing units 2135 that press each of the two ribs 2126 in the +X direction from the −X direction side of each of the two ribs 2126. The pressing units 2134 have a unit main body 21341 in the shape of a flat rectangular box, a piston 21342 whose tip abuts against the lateral side of the rib 2126 on the +X direction side and is movable in the X-axis direction, and a biasing member 21343. The piston 21342 has a bottomed cylindrical piston body 21342a with a bottom wall that bulges dome-like toward the -X direction and abuts against the rib 2126, and an outer flange 21342b that protrudes from the end of the piston body 21342a on the +X direction side in a direction away from the cylindrical axis of the piston body 21342a. The outer flange 21342b of the piston 21342 and the biasing member 21343 are housed inside the unit body 21341. The biasing member 21343 is housed inside the unit body 21341 with one end abutting against the outer flange 21342b of the piston 21342 and the other end abutting against the inner wall of the unit body 21341. The biasing member 21343 is, for example, a coil spring. The biasing member 21343 may be an air cylinder, an elastic member such as rubber, or the like. The pressing unit 2135 includes a flat, rectangular box-shaped unit main body 21351, a piston 21352 whose tip abuts the −X-direction side of the rib 2126 and is movable in the X-axis direction, and a biasing member 21353. The piston 21352 includes a piston main body 21352a that is cylindrical with a bottom and has a bottom wall that bulges out like a dome toward the +X-direction side and abuts the rib 2126, and an outer flange 21352b that protrudes from the −X-direction end of the piston main body 21352a in a direction away from the cylindrical axis of the piston main body 21352a. The outer flange 21352b of the piston 21352 and the biasing member 21353 are housed inside the unit main body 21351. The biasing member 21353 is housed inside the unit body 21351 with one end abutting against the outer flange 21352 b of the piston 21352 and the other end abutting against the inner wall of the unit body 21351 .The biasing member 21353 is also, for example, a coil spring.

[0032] When the first support portion 2012 is located at the reference position as shown in FIG. 16A , all of the tip portions of the pistons 21342 and 21352 are in contact with the rib 2126. Assume now that an external force in the +X direction is applied to the first support portion 2012 supporting the workpiece holder 2011, causing the first support portion 2012 to shift from the reference position in the +X direction, as shown by arrow AR211 in FIG. 16B . In this case, the two pistons 21342 are each pressed in the +X direction by the rib 2126 of the first support portion 2012, and the biasing members 21343 in contact with the outer flanges 21342b of each of the two pistons 21342 are compressed. At this time, the restoring force of the biasing members 21343 causes the two pistons 21342 to press the rib 2126 in the direction shown by arrow AR212. Furthermore, a gap is formed between each of the two pistons 21352 and the rib 2126. When the external force applied to the workpiece holding portion 2011 is released, the rib 2127 of the first support portion 2012 is pressed by the two pistons 21342, causing the first support portion 2012 to move in the +Y direction and return to the reference position.

[0033] Next, an operation of the AGV 2002 equipped with the transfer device 2001 according to this embodiment transferring the workpiece W2 to the station 2003 will be described. As shown by the arrow AR231 in FIG. 17 , the AGV 2002 approaches the station 2003 from a direction intersecting the Y-axis direction while holding the workpiece W2. In this case, first, the roller 2113 of the transfer device 2001 abuts against the inclined piece 2033 of the guide plate 2033 of the station 2003. Then, when the AGV 2002 further penetrates the back side of the station body 2031 of the station 2003, the roller 2113 is guided by the inclined piece 2332 and is positioned between the main pieces 2331 of the two guide plates 2033. At this time, the transfer device 2001 rotates the entire workpiece holding unit 2011 relative to the first support unit 2012, or moves the first support unit 2012 supporting the workpiece holding unit 2011 in the X-axis direction relative to the second support unit 2015, so that the longitudinal direction of the holding table 2111 of the workpiece holding unit 2011 coincides with the longitudinal direction of the slit 2032a formed in the top plate 2032 of the station 2003. This makes it possible to align the longitudinal direction of the holding table 2111 with the longitudinal direction of the slit 2032a of the station 2003, regardless of the direction in which the AGV 2002 enters the station 2003. Next, the AGV 2002 lowers the entire transfer device 2001, thereby supporting the workpiece W2 on the outer peripheries of both sides of the slit 2032a in the X-axis direction. Thereafter, the AGV 2002 moves away from the station 2003 with the entire transfer device 2001 lowered, thereby completing the transfer of the workpiece W2 to the station 2003.

[0034] As described above, according to the transfer device 2001 of this embodiment, the first support portion 2012 supports the workpiece holding portion 2011 rotatably around the rotation axis J2, and the second support portion 2015 supports the first support portion 2012, which supports the workpiece holding portion 2011, movably in the X-axis direction. Meanwhile, the posture return mechanism 2014 urges the workpiece holding portion 2011 in a direction returning to the reference posture when the workpiece holding portion 2011 rotates from the reference posture relative to the first support portion 2012 in the rotation direction about the rotation axis J2, and the reference position return mechanism 2013 urges the first support portion 2012 in a direction returning to the reference position when the first support portion 2012 moves from the reference position in the X direction relative to the second support portion 2015. As a result, when transferring the workpiece W2 to the station 2003, even if the direction of entry of the AGV 2002 into the station 2003 intersects with the Y-axis direction, the workpiece holding unit 2011 rotates relative to the first support unit 2012, and the first support unit 2012 moves relative to the second support unit 2015 in the X-axis direction, so that the longitudinal direction of the holder 2111 of the workpiece holding unit 2011 and the longitudinal direction of the slit 2032a of the station 2003 are aligned, thereby enabling the workpiece W2 to be smoothly transferred to the station 2003. Furthermore, when the AGV 2002 is released from the station 2003, the attitude return mechanism 2014 and the reference position return mechanism 2013 can automatically return the workpiece W2 to the reference attitude and reference position again, which makes it easy to position the workpiece W2 on the holder 2111 of the workpiece holding unit 2011 the next time the workpiece W2 is placed on the holder 2111. Therefore, the workpiece W2 can be transferred from the workpiece holder 2011 to the station 2003 and placed on the holder 2111 of the workpiece holder 2011 in an appropriate manner.

[0035] Although the embodiments of the present invention have been described above, the present invention is not limited to the configurations of the above-described embodiments. For example, as in the transfer device 3001 shown in FIG. 18 , the structure of the reference posture return mechanism 3014 may be different from that of the reference posture return mechanism 14 of embodiment 1. Note that in FIG. 18 , the same components as in embodiment 1 are denoted by the same reference symbols as in FIG. 3 . The transfer device 3001 includes a workpiece holder 3011, a first support 3012 that supports the workpiece holder 3011 rotatably around the rotation axis J3, a reference posture return mechanism 3014, a second support 15 that supports the first support 3012 movably in the X and Y directions, and a reference position return mechanism 13. The workpiece holder 3011 includes a cylindrical holder main body 3111, a holding piece 112, an arm 113, and a main body support 3114 that supports the holder main body 3111. The main body support portion 3114 has a cylindrical main portion 31141 having one end in the column axis direction fixed to the holding portion main body 3111, and a disk-shaped portion 31142 having a disk shape and fixed to the other end of the main portion 31141.

[0036] The first support part 3012 has a plate-shaped support part main body 3121 having a through-hole 3121b that is circular in plan view and penetrates through the thickness direction, a plurality of rolling elements 3122 placed on the +Z direction side of the support part main body 3121, and a retainer (not shown) that holds the plurality of rolling elements 3122. Recesses 3121a are formed at two locations on the +Z direction side of the periphery of the support part main body 3121.

[0037] 19A and 19B , the reference attitude return mechanism 3014 includes a roller 3141 that abuts against the inside of the recess 3121a of the support portion main body 3121 of the first support portion 3012 from the +Z direction side of the recess 3121a, a roller support portion 3142, and a roller biasing portion 3143 that biases the roller support portion 3142 toward the support portion main body 3121. The roller biasing portion 3143 has a biasing member having one end fixed to the −Z direction side of the disk-shaped portion 31142 of the main body support portion 3114 of the workpiece holding portion 3011 and the other end fixed to the roller support portion 3142. The biasing member may be, for example, a coil spring. Note that the biasing member may also be an air cylinder, an elastic member such as rubber, or the like. Roller biasing portion 3143 biases roller 3141 and roller support portion 3142 toward support portion main body 3121 as shown by arrow AR311 by the restoring force of the biasing member.

[0038] In the reference attitude return mechanism 3014, when an external force is applied to the workpiece holding unit 3011 in the direction of rotation about the rotation axis J3, and the workpiece holding unit 3011 rotates relative to the first support unit 3012 from a preset reference attitude as shown in FIG. 19A in the direction of rotation about the rotation axis J3, the roller 3141 moves along the inner inclined surface 3121c of the recess 3121a of the support unit main body 3121. At this time, as shown in FIG. 19B , a biasing force is generated in the roller 3141 in the direction indicated by arrow AR311 due to the restoring force of the biasing member of the roller biasing unit 3143. This biasing force then generates a force in the main body support unit 3114 of the workpiece holding unit 3011 to rotate in the direction indicated by arrow AR312 to return to the basic attitude, and the workpiece holding unit 3011 is biased in the direction to return to the reference attitude shown in FIG. 19A .

[0039] According to this configuration, when the work holding portion 3011 is detached from the work W1, the reference posture return mechanism 3014 can automatically return the work holding portion 3011 to the reference posture, making it easier to position the work W1 in the work holding portion 3011 when the work W1 is next placed on the work holding portion 3011.

[0040] Although the embodiments and modifications of the present invention have been described above, various embodiments and modifications of the present invention are possible without departing from the broad spirit and scope of the present invention. Furthermore, the above-described embodiments are intended to explain the present invention and do not limit the scope of the present invention. That is, the scope of the present invention is defined by the claims, not the embodiments. Various modifications made within the scope of the claims and the meaning of the invention equivalent thereto are considered to be within the scope of the present invention.

[0041] This application is based on Japanese Patent Application No. 2024-084088, filed on May 23, 2024. The entire specification, claims and drawings of Japanese Patent Application No. 2024-084088 are incorporated herein by reference.

[0042] The present invention is suitable for transporting workpieces to machine tools and the like using an automatic guided vehicle.

[0043] 1, 2001, 3001: Transfer device, 2, 2002: AGV, 3: Machine tool, 11, 2011, 3011: Workpiece holder, 12, 2012, 3012: First support part, 13, 2013: Reference position return mechanism, 14, 2014, 3014: Reference attitude return mechanism, 15, 2015: Second support part, 21, 2021: AGV main body, 22: Shaft, 23, 113: Arm, 23a, 121a, 151a, 3121b: Through hole, 24: Elevation drive part, 31: Stage, 32, 2112: Support, 33: Head, 111, 2115, 3111: Holder main body, 112: Holder piece , 112a, 122a: protrusions, 114, 31142: disc-shaped portions, 114a, 3121a: recesses, 114b, 3121c: inclined surfaces, 121, 151, 1421, 2121, 2151, 3121: support body, 122: bearings, 141, 2113, 3141: rollers, 142, 2114, 3142: roller support portions, 143, 3143: roller biasing portions, 152, 1223, 3122: rolling elements, 153: cages, 1221: outer rings, 1222: inner rings, 1321, 1322, 1323, 1324, 2134, 2135, 2141, 2142: pressing units, 142 2, 1423, 2114c, 2123: shaft portion, 1431, 13213, 13223, 13233, 13243, 21353, 21413, 21423: biasing member, 1432, 13212, 13222, 13232, 13242: fixed portion, 2003: station, 2016: base member, 2022: lifting unit, 2031: station body, 2032: top plate, 2032a, 2228a: slit, 2111: holder, 2114a, 2114b: support piece, 2121a, 31141: main portion, 2121b: extension portion, 2121c, 2151a: opening, 2125: rotation restriction pin, 2126, 2127: rib, 2152, 2223: rail, 2153, 2222. 13211, 13221, 13231, 13241: slider, 2161: base body, 2162: protrusion, 2221: frame, 2228: cover, 2229: housing, 2331: main piece, 2332: inclined piece, 13214, 13234: pressure restriction portion, 13224, 13244: movement restriction portion, 21341, 21411, 21421: unit body, 21352: piston, 21352a: piston body, 21352b: outer flange portion, 21411a,21421a: first part, 21411b, 21421b, JI12: groove, 21411c, 21421c: second part, 21412, 21422: pin, 21412a, 21422a: elongated part, 21412b, 21422b: base end part, 31141: main part, De1, De2: recess, J1: rotation axis, JI1: jig, JI11: protrusion, W1: workpiece,

Claims

1. A transfer device comprising: a work holding section that holds a workpiece; a first support section that supports the work holding section so that it can rotate freely in a rotational direction about a predetermined rotation axis; a reference position return mechanism that urges the work holding section in a direction returning to the reference position when a first external force is applied to the work holding section in the direction of rotation about the rotation axis, causing the work holding section to rotate from a predetermined reference position relative to the first support section in the rotational direction about the rotation axis; a second support section that supports the first support section so that it can move freely in a direction perpendicular to a first direction along the rotation axis; and a reference position return mechanism that urges the first support section in a direction returning to the reference position when a second external force is applied to the first support section in the direction perpendicular to the first direction, causing the first support section to move from a predetermined reference position relative to the second support section in a direction perpendicular to the first direction.

2. The transfer device according to claim 1, wherein the work holding section comprises: a cylindrical holding section main body; a holding piece that holds the workpiece; an arm having a base end fixed to one end of the holding section main body in the column axis direction and having the holding piece provided at its tip end; and a disk-shaped section that is disk-shaped and has a recess formed in at least one location in the circumferential direction and is provided at the other end of the holding section main body in the column axis direction so that its central axis along the thickness direction coincides with the column axis of the holding section main body; the first support section comprises: a plate-shaped first support section main body having a first through hole that is circular in plan view and penetrates through the thickness direction; and a bearing that is fixed to the first support section main body while fitted into the first through hole of the first support section main body and rotatably supports the holding section main body located inside; and the reference attitude return mechanism comprises: a roller that abuts against the inside of the recess from the outside in the radial direction of the disk-shaped section; and a roller biasing section that biases the roller towards the center of the disk-shaped section.

3. The second support part is plate-shaped and has a second through-hole formed therethrough in the thickness direction, and has a second support part main body with the holding part main body inserted into the second through-hole, and movably supports the first support part via rolling elements on the surface side facing the first support part in the thickness direction, and the reference position return mechanism has: a first pressing unit that presses the first support part in a third direction opposite to the second direction from a second direction side of the first support part that is perpendicular to the first direction; a second pressing unit that presses the first support part in the second direction from the third direction side of the first support part; a third pressing unit that presses the first support part in a fifth direction opposite to the fourth direction from a fourth direction side of the first support part that is perpendicular to the first direction and perpendicular to the second and third directions; and a fourth pressing unit that presses the first support part in the fourth direction from the fifth direction side of the first support part. The transfer device according to claim 2 .

4. The first pressing unit has: a first slider that abuts against the second direction side of the first support part and is movable along the second direction; and a first slider biasing part that biases the first slider in the third direction; the second pressing unit has: a second slider that abuts against the third direction side of the first support part and is movable along the third direction; and a second slider biasing part that biases the second slider in the second direction; the third pressing unit has: a third slider that abuts against the fourth direction side of the first support part and is movable along the fourth direction; and a third slider biasing part that biases the third slider in the fifth direction; and the fourth pressing unit has: a fourth slider that abuts against the fifth direction side of the first support part and is movable along the fifth direction; and a fourth slider biasing part that biases the fourth slider in the fourth direction. The transfer device according to claim 3 .

5. A transfer device as described in claim 3 or 4, wherein a first pressing force with which the first pressing unit presses the first support part is greater than a second pressing force with which the second pressing unit presses the first support part, a third pressing force with which the third pressing unit presses the first support part is greater than a fourth pressing force with which the fourth pressing unit presses the first support part, and the reference position return mechanism has a first pressing regulating part that regulates the pressing of the first support part by the first pressing unit when the first support part is arranged at the reference position, and a second pressing regulating part that regulates the pressing of the first support part by the third pressing unit.

6. The transfer device according to claim 1, wherein the work holding section comprises: a long holding section main body; a holding base that holds the work; and a columnar support having a base end fixed to the holding section main body at a position shifted toward the other end of the one longitudinal end of the holding section main body and supporting the holding base at its tip; the first support section has a plate-shaped first support section main body and rotatably supports the one end of the holding section main body via a shaft on one side of the thickness direction facing the work holding section; and the reference attitude return mechanism comprises: a fifth pressing unit that presses the holding section main body from a seventh direction side of the holding section main body that is perpendicular to the sixth direction along the thickness direction of the first support section main body in an eighth direction that is opposite to the seventh direction; and a sixth pressing unit that presses the holding section main body from the eighth direction side of the holding section main body in the seventh direction.

7. A transfer device as described in claim 6, wherein the first support part further has a rib protruding from the first support part main body on the side opposite to the one surface side in the thickness direction of the first support part main body, the second support part is arranged opposite to the other surface side in the thickness direction of the first support part main body, and the reference position return mechanism has: a seventh pressing unit that presses the rib in the eighth direction from the seventh direction side of the rib, and an eighth pressing unit that presses the rib in the seventh direction from the eighth direction side of the rib.

Images