Holder with compliance mechanism

Abstract

To provide a holder with a compliance mechanism capable of generating a floating state and a locking state with a simple structure.SOLUTION: A compliance mechanism 7 selectively generates a floating state where a holding part 3 is moved to a position where a workpiece W can be held without being moved through displacement caused by a load applied to the holding part 3 and a locking state where the position displacement of the holding part 3 with respect to a support 5 is blocked. The compliance mechanism 7 is provided with a slide mechanism 19 for permitting a mounting part 17 to slide along a parallel line PL parallel to a shared virtual center line CL with respect to the support 5 in the floating state, and a fluid pressure circuit 21 disposed between first and second cylinder mechanisms 9 and 15 and a fluid drive source FS to selectively generate the floating state and the locking state.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a workpiece holding device, and more particularly to a holding device equipped with a compliance mechanism. [Background technology]

[0002] Japanese Patent Laid-Open Publication No. 5-269689 (Patent Document 1) discloses a conventional holding device equipped with a floating mechanism and a gripping part as a holding part. In this conventional holding device, a compliance mechanism including a locking means disposed between the holding part and the support part (main body) selectively forms a floating state in which the holding part is displaced by a load applied to the holding part to move the holding part to a position where the work can be held without moving, and a locked state in which the position of the holding part relative to the support part is prevented from being displaced. When holding a work by gripping it, compliance (flexibility) of the holding part is required. On the other hand, when mounting the gripped work in a line, a certain degree of hardness (locking) is required. In the conventional holding device, compliance (flexibility) is imparted in a floating state. And hardness is realized in a locked state during transportation. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 5-269689 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the holding device shown in Patent Document 1, the configuration of the locking means is not clearly disclosed, so it is unclear whether the holding part is returned to the origin position by selecting the locked state before holding the workpiece with the holding part. Therefore, even if Patent Document 1 is looked at, it is not possible to easily configure a compliance mechanism equipped with a locking means. If the holding part can be returned to the origin position, the holding operation can be accurately controlled regardless of the position of the holding part relative to the support part.

[0005] In addition, in the structure shown in Patent Document 1, if the support part is inclined with respect to the vertical direction in a floating state, as soon as the workpiece is lifted, the holding part that holds the workpiece in a vertically downward direction may shift and collide with the guide end, causing the workpiece to fall due to the impact. Such a tilt of the support part occurs all the time, for example, in a holding device installed in a place called a "wet area" in a food factory. In the "wet area," it is important to form a drainage plan and an appropriate floor gradient according to the arrangement of production equipment, etc., for cleaning. For this reason, the ground contact surface of the robot and pallet has a floor gradient (1.0 to 2.0 / 100). When the holding device is installed in a place with such a floor gradient, it is sufficient to quickly lock the gripping part that constitutes the holding part at the moment it lifts the workpiece, but if it is locked at high speed, the gripping part's claws and the workpiece will collide with each other while being centered because of the floating state. If the gripping part is offset from the center of the workpiece, when the workpiece comes into contact with one of the claws, it may bounce because it is in a free state and the claw on the opposite side may collide with the workpiece. If this happens, not only can the workpiece fall, but it can also lead to wear and damage to the chuck jaws.

[0006] An object of the present invention is to provide a holding device equipped with a compliance mechanism that can establish a floating state and a locked state with a simple structure.

[0007] It is a further object of the present invention to provide a holding device having a compliance mechanism that prevents the holding portion from being suddenly displaced in a floating state. [Means for solving the problem]

[0008] The present invention relates to a holding device including a holding part for holding a workpiece, a support part for supporting the holding part, and a compliance mechanism disposed between the holding part and the support part. The compliance mechanism selectively forms a floating state in which the holding part is displaced by a load applied to the holding part to move the holding part to a position where the workpiece can be held without being moved, and a locked state in which the position of the holding part is prevented from being displaced relative to the support part. The compliance mechanism includes a first cylinder mechanism including one or more cylinders with rods and fixed to the support part, a second cylinder mechanism including one or more cylinders with rods and fixed to a mounting part to which the holding part is attached, a connecting part connecting one or more rods of the first cylinder mechanism and one or more rods of the second cylinder mechanism so as to be linearly movable along a common virtual center line CL, a slide mechanism disposed between the support part and the mounting part and allowing the mounting part to slide along a parallel line PL parallel to the common virtual center line CL relative to the support part in the floating state, and a fluid pressure circuit disposed between the first cylinder mechanism, the second cylinder mechanism, and a fluid drive source and selectively forming a floating state and a locked state. The holding portion may be either a gripping portion having a mechanical structure with at least a pair of holding claws, or an adsorption portion having an adsorption pad.

[0009] According to the present invention, when the first and second cylinder mechanisms of the compliance mechanism are first locked by supplying high-pressure fluid from the fluid pressure circuit, the mounting part to which the holder is attached always returns to the origin position relative to the support part. In other words, before holding and transporting a workpiece, the holding part attached to the mounting part can always be returned to the origin relative to the support part and its position controlled. As a result, the position control of the holding part becomes accurate. When the holding part holds a workpiece, if the compliance mechanism is put into a floating state by controlling the fluid pressure supplied from the fluid pressure circuit, the holding part moves following the workpiece, and the mounting part to which the holding part is attached moves smoothly. As a result, the holding part can hold the workpiece accurately in a position suitable for holding the workpiece.

[0010] When the holding part holds a workpiece and then transports the workpiece, if the compliance mechanism is locked by the fluid pressure circuit and the support part is moved, the position of the mounting part to which the holding part holding the workpiece is attached does not change relative to the support part. Therefore, the workpiece can be securely held and transported without being subjected to excessive vibration. In this way, according to the present invention, it is possible to provide a holding device equipped with a compliance mechanism that can reliably form a floating state and a locked state using a cylinder mechanism with a simple structure.

[0011] The fluid pressure circuit preferably supplies a high pressure to the first cylinder mechanism and the second cylinder mechanism to realize the locked state, and when the floating state is realized, supplies a fluid with a lower pressure than the high pressure supplied to the first cylinder mechanism and the second cylinder mechanism to realize the locked state. Specifically, the low fluid pressure is a pressure that is lower than the high fluid pressure and provides resistance to the holding part to the extent that the position of the holding part cannot be maintained against the weight of the load. In this way, even in the floating state, a certain resistance is provided to the holding part according to the level of the low supply pressure provided. As a result, even if the installation surface of the holding device is inclined, for example, the mounting part equipped with the holding part does not suddenly move just because it is in the floating state. As a result, even in the floating state, the impact and vibration applied to the holding part can be suppressed by appropriately determining the low pressure of the fluid supplied to the first cylinder mechanism and the second cylinder mechanism.

[0012] The support part can be composed of a frame that is driven and controlled, a support extending in a direction intersecting the frame, and a fixed part provided on the support to which the first cylinder mechanism is fixed. The mounting part can be composed of a mounting part main body that slides along the support via a slide mechanism, and a fixed part provided on the mounting part main body to which the second cylinder mechanism is fixed. The holding part 1 is attached to the mounting part main body. By adopting such a structure, the degree of freedom in positioning the holding part relative to the support part is increased. In other words, not only can the mounting position of the holding part be determined at a position considerably separated in the perpendicular direction from a virtual line passing through the support part in the longitudinal direction, but the mounting position of the holding part can also be determined on a virtual line passing through the support part in the longitudinal direction.

[0013] A rotation mechanism for rotating the support or the holder may be disposed between the frame and the support or between the mounting body and the holder. By providing such a rotation mechanism, the operating range of the holder can be expanded.

[0014] The first cylinder mechanism and the second cylinder mechanism may have any configuration. For example, at least one of the first cylinder mechanism and the second cylinder mechanism may each be configured with two or more cylinders arranged in parallel. Furthermore, one or more rods of the first cylinder mechanism and one or more rods of the second cylinder mechanism may be fixed to a connecting portion extending in a direction perpendicular to the common imaginary center line CL.

[0015] The fluid pressure circuit can operate, for example, as follows. First, high-pressure fluid is supplied to the first and second cylinder mechanisms to lock the positional relationship between the mounting part and the support part. Then, a low-pressure fluid that is lower than the high-pressure fluid and allows the mounting part to move relative to the support part is supplied to the first and second cylinder mechanisms to create a floating state. The floating state is maintained at least until the holding part holds the workpiece. Then, after the holding part holds the workpiece and the workpiece is in a non-contact state with the adjacent workpiece, high-pressure fluid is supplied to the first and second cylinder mechanisms to lock the positional relationship between the mounting part and the support part. [Brief description of the drawings]

[0016] [Figure 1] 1 is a perspective view showing a main part of a configuration of a holding device having a compliance mechanism of the present invention, according to an embodiment in which the holding device is applied to a transport device. [Diagram 2] FIG. 2A is a front view of the main part of FIG. 1, and FIG. 2B is a view showing the compliance mechanism in a locked state. [Diagram 3] FIG. 1C is a diagram showing a floating state of the compliance mechanism, and FIG. 1D is a diagram showing a state in which the workpiece is gripped by the holding portion. [Figure 4] FIG. 10E is a diagram showing a state in which the holding part has been slightly moved upward, and FIG. 10F is a diagram showing a state in which the holding part has been moved to an equilibrium position by the compliance mechanism in a floating state. [Diagram 5]FIG. 1G shows the state in which high-pressure fluid is supplied to the cylinders of the first and second cylinder mechanisms to lock the compliance mechanism, and FIG. 1H shows the state in which the support part consisting of the lifting frame moves the workpiece to a predetermined open position. [Figure 6] 13A and 13B are diagrams showing a main part of the configuration of a holding device having a compliance mechanism according to a second embodiment of the present invention. [Figure 7] 13A and 13B are diagrams showing the main components of a holding device having a compliance mechanism according to a third embodiment of the present invention; [Figure 8] 13(A) and 13(B) are diagrams respectively showing the main parts of the configuration of a holding device having a compliance mechanism according to a fourth embodiment of the present invention. [Figure 9] 13(A) to 13(C) are diagrams respectively showing the main parts of the configuration of a holding device having a compliance mechanism according to a fifth embodiment of the present invention. [Figure 10] 10(A) and 10(B) are diagrams illustrating a state in which the compliance mechanism illustrated in FIG. 9 is in a floating state. [Figure 11] 13(A) and 13(B) are diagrams showing modified examples of the configuration and arrangement of the first cylinder mechanism and the second cylinder mechanism in the compliance mechanism. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view showing a main part of the configuration of a holding device according to an embodiment in which a holding device 1 having a compliance mechanism of the present invention is applied to a transport device. FIG. 2(A) is a front view of the main part. The holding device 1 shown in FIG. 1 and FIG. 2(A) includes a holding unit 3 called a hand that holds a workpiece W, a support unit 5 that is formed by a lifting frame of the transport device and indirectly supports the holding unit 3, and a compliance mechanism 7 that is disposed between the holding unit 3 and the support unit 5. The holding unit 3 used in this embodiment is a gripping unit that includes two claws 31 and grips the workpiece W with the two claws 31. The two claws 31 of the holding unit 3 are in a state in which the two claws 31 are opened wider than the width dimension of the workpiece W until they are driven by electromagnetic drive or air drive, and when they are driven by electromagnetic drive or air drive, the two claws 31 move to close in a direction that sandwiches the workpiece W.

[0018] The compliance mechanism 7 selectively forms a floating state in which the holding part 3 is displaced by a load applied to the claw part 31 of the holding part 3 to a position where the workpiece W can be held without being moved, and a locked state in which the position of the holding part 3 relative to the support part 5 is prevented from being displaced. The compliance mechanism 7 includes a first cylinder mechanism 9 including one or more cylinders 8 equipped with a rod 81 and fixed to the support part 5, and a second cylinder mechanism 15 including one or more cylinders 10 equipped with a rod 11 and fixed to a plate-shaped mounting part 17 to which the holding part 3 is attached. In this embodiment, a support 51 extending in a direction perpendicular to the support part at the tip of the support part 5 and a fixed plate 52 extending from one end of the back surface of the support 51 are provided. The cylinder 8 is fixed to the fixed plate 52 so that the rod 81 can protrude along the imaginary center line CL. The mounting part 17 is composed of a mounting part main body 17A which slides along the support body 51 via a slide mechanism 19, and a fixed part 17B which is provided on the mounting part main body 17A and to which the second cylinder mechanism 15 is fixed. The slide mechanism 19 is a linear guide composed of a rail 19A mounted on the plate-shaped mounting part 17, and two slide guide parts 19B fixed to the support body 51 of the support part 5 which is made up of a lifting frame.

[0019] The cylinder 10 is fixed to the fixed portion 17B extending from the middle position on the back surface of the mounting portion main body 17A of the mounting portion 17 so that the rod 11 can protrude along the imaginary center line CL. The holding portion 3 is attached to the mounting portion main body 17A. By adopting such a structure, the degree of freedom in positioning the holding portion 3 with respect to the support portion 5 is increased. That is, not only can the mounting position of the holding portion 3 be determined at a position considerably separated in the perpendicular direction from the imaginary line C passing through the support portion 5 in the longitudinal direction, but the mounting position of the holding portion 3 can also be determined on the imaginary line C passing through the support portion 5 in the longitudinal direction.

[0020] The compliance mechanism 7 also includes a connecting portion 18 that connects the rods 81 of the one or more cylinders 8 of the first cylinder mechanism 9 and the one or more rods 11 of the one or more cylinders 10 of the second cylinder mechanism 15 so as to be linearly movable along the common imaginary center line CL, and a slide mechanism 19 that is disposed between the support body 51 of the support unit 5 and the mounting portion 17 and allows the mounting portion 17 to slide along a parallel line PL that is parallel to the common imaginary center line CL relative to the support unit 5 in the floating state. The connecting portion 18 in this embodiment has a structure that connects the tips of the rods 81 and 11.

[0021] Furthermore, the compliance mechanism 7 is provided with a fluid pressure circuit 21 that is disposed between the first cylinder mechanism 9 and the second cylinder mechanism 15 and the fluid drive source FS and selectively forms a floating state and a locked state. The fluid pressure circuit 21 supplies a high pressure to the first cylinder mechanism 9 and the second cylinder mechanism 15 to realize the locked state, and when the floating state is realized, supplies a fluid (low pressure fluid) with a lower pressure than the high pressure supplied to the first cylinder mechanism 9 and the second cylinder mechanism 15 to realize the locked state as the fluid pressure supplied to the first cylinder mechanism 9 and the second cylinder mechanism 15. In this way, even in the floating state, a certain resistance is applied to the holding part 3 according to the level of the pressure of the low pressure fluid. As a result, even if the installation surface of the holding device 1 is inclined, for example, the mounting part 17 equipped with the holding part 3 does not suddenly move even if it is in the floating state. As a result, even in a floating state, shocks and vibrations applied to the holding portion 3 can be suppressed by appropriately determining the pressures supplied to the first cylinder mechanism 9 and the second cylinder mechanism 15.

[0022] The operation of the holding device 1 of this embodiment will be described with reference to Figures 2 to 5. First, the support part 5 is driven to move the holding device 1 so that the holding part 3 is positioned above the workpiece W as shown in Figure 2(A). Next, the holding device 1 is lowered toward the workpiece W as shown in Figure 2(B). At this time, high-pressure fluid is supplied to the first and second cylinder mechanisms 9 and 15, and the positional relationship between the mounting part 17 and the support part 5 is locked. Basically, the locked state is the normal state, and this state is the origin state (the state in the reference position).

[0023] Then, a low-pressure fluid, which has a lower pressure than the high-pressure fluid and allows the mounting portion 17 to move relative to the support portion 5, is supplied to the first and second cylinder mechanisms 9 and 15 to create a floating state [Figure 3(C)].

[0024] The floating state is maintained at least until the holding unit 3 holds the workpiece W. As shown in Figures 3(C) and (D) , when the workpiece W is clamped between the two claws 31 of the holding unit 3, the claws 31 move following the workpiece W, and the holding unit 3 moves together with the mounting unit 17 relative to the support body 51 of the support unit 5 via the slide mechanism 19.

[0025] Next, the workpiece W is gripped by the holder 3 in the state shown in Fig. 3(D), and then the holder 3 is moved slightly upward as shown in Fig. 4(E). In this embodiment, since the workpiece W is in an engaged state with the workpiece W below, when the holder 3 is moved upward as shown in Fig. 4(F) until this engaged state is released, the holder 3 is moved to an equilibrium position by the compliance mechanism 7 in a floating state. That is, in this embodiment, the mounting part 17 (holder 3) moves to an equilibrium position determined by the resistance generated by the pressure of the low-pressure fluid supplied to the cylinders of the first and second cylinder mechanisms 9 and 15.

[0026] Next, as shown in Fig. 5(G), when high-pressure fluid is supplied to the cylinders of the first and second cylinder mechanisms 9 and 15 to lock the compliance mechanism 7, the slide mechanism 19 of the compliance mechanism 7 is in the origin state, and the positional relationship between the mounting part 17 and the support part 5 is locked. From this state, the support part 5, which is made up of a lifting frame, moves the workpiece W to a predetermined release position [Fig. 5(H)].

[0027] FIG. 6 is a diagram showing the main part of the configuration of a holding device having a compliance mechanism according to a second embodiment of the present invention. In FIG. 6, the same members as those in the first embodiment shown in FIGS. 1 to 5 are denoted by the same reference numerals as those in FIGS. 1 to 5. Compared with the first embodiment, in the second embodiment, the configurations of the mounting part 117 and the slide mechanism 119 of the compliance mechanism 71 of the holding device 100 are different from those of the mounting part 17 and the slide mechanism 19 of the first embodiment. The mounting part body 117A of the mounting part 117 in the second embodiment has a crank shape. One end of a rod 119A constituting a part of the slide mechanism 119 is fixed to the base of the mounting part body 117A. The rod 119A extends along a parallel line PL parallel to the common virtual center line CL. The rod 119A is journaled on a bearing part 119B made of a ball bush fixed to the back surface of the support 51. The crank-shaped mounting body 117A is fitted with the holding part 3 consisting of a gripping part or the holding part 3' consisting of an adsorption part. According to this embodiment, the bearing part 119B consisting of a ball bush is used, so the slide mechanism 119 can be constructed at low cost. In addition, since the slide mechanism does not get in the way, there is an advantage that the holding part 3 can be inserted into a narrow space.

[0028] FIG. 7 is a diagram showing the main part of the configuration of a holding device having a compliance mechanism according to a third embodiment of the present invention. In FIG. 7, the same members as those in the second embodiment shown in FIG. 6 are given the same reference numerals as those in FIG. 1 to FIG. 6. Compared to the second embodiment, in the compliance mechanism 72 of the holding device 200 of the third embodiment, the configurations of the mounting part 117' and the slide mechanism 119' are different from those of the mounting part 117 and the slide mechanism 119 of the second embodiment. A pair of fixed parts 117'B is fixed to the mounting part main body 117'A of the mounting part 117' of the third embodiment, and a rod 119'A is fixed to the pair of fixed parts 117'B. And two bearing parts 119'B on which the rod 119'A is journaled are fixed to the slide mechanism 119'. According to this embodiment, the force applied to the rod 119'A can be distributed in a well-balanced manner compared to the second embodiment.

[0029] 8(A) and (B) are diagrams showing the main parts of the configuration of a holding device having a compliance mechanism according to the fourth embodiment of the present invention. In FIG. 8(A) and (B), the same members as those in the first embodiment shown in FIG. 1 to FIG. 5 are given the same reference numerals as those in FIG. 1 to FIG. 5. Compared with the first embodiment, in the compliance mechanism 73 of the holding device 300 of the fourth embodiment, the configurations of the mounting part 217 and the slide mechanism 219 are different from those of the mounting part 17 and the slide mechanism 19 of the first embodiment. The mounting part body 217A of the mounting part 217 of the second embodiment has approximately the same size as the cylinder 10 of the fourth cylinder mechanism 15. A slide guide part 219B constituting a part of the slide mechanism 219 is fixed to the mounting part body 217A. A rail 219A constituting a part of the slide mechanism 219 is fixed to the support body 51 of the support part 5. According to this embodiment, as shown in Fig. 8(A), when the compliance mechanism 73 is in the locked state, the virtual line C passing through the center of the support part 5 can be aligned with the center of the holding part 3. As a result, the length dimension of the holding device can be made shorter than in the first embodiment, making the entire device more compact. Fig. 8(B) is a diagram showing the compliance mechanism 73 in a floating state.

[0030] 9(A) to 9(C) are diagrams showing the main parts of the configuration of a holding device having a compliance mechanism according to a fifth embodiment of the present invention. In FIG. 9(A) to 9(C), the same members as those in the first embodiment shown in FIG. 1 to 5 are denoted by the same reference numerals as those in FIG. 1 to 5. Compared with the first embodiment, in the compliance mechanism 74 of the holding device 400 of the fifth embodiment, the connection configuration of the first cylinder mechanism 9 and the second cylinder mechanism 15 and the configuration of the mounting part 317 and the slide mechanism 319 are different from those of the first cylinder mechanism 9 and the second cylinder mechanism 15 and the configuration of the mounting part 17 and the slide mechanism 19 of the first embodiment. In the fifth embodiment, the cylinder 308 of the first cylinder mechanism 9 and the cylinder 310 of the second cylinder mechanism 15 are arranged side by side, and the rod 381 of the first cylinder mechanism 9 and the rod 311 of the second cylinder mechanism 15 are arranged in parallel and are connected to each other by the connecting part 318. In the fifth embodiment, mounting portion main body 317A of mounting portion 317 has a size smaller than cylinder 310 of second cylinder mechanism 15. A slide guide portion 319B constituting a part of slide mechanism 319 is fixed to mounting portion main body 317A. Also, rail 319A constituting a part of slide mechanism 319 is fixed to support body 51 of support portion 5. Fig. 9(C) shows the state of cylinder 308 of first cylinder mechanism 9 and cylinder 310 of second cylinder mechanism 15 when compliance mechanism 74 is in the locked state.

[0031] 10(A) and (B) show the states of the cylinder 308 of the first cylinder mechanism 9 and the cylinder 310 of the second cylinder mechanism 15 when the compliance mechanism 74 is in a floating state and the connecting parts 318 are at their left and right end positions, respectively. According to this embodiment, the cylinder 308 of the first cylinder mechanism 9 and the cylinder 310 of the second cylinder mechanism 15 are arranged side by side, so that the overall length of the compliance mechanism 74 can be shortened.

[0032] 11(A) and (B) show modified examples of the configuration and arrangement of the first cylinder mechanism 9 and the second cylinder mechanism 15 in the compliance mechanism. As shown in Fig. 11(A), one or the other of the cylinder mechanisms 9 and 15 can be composed of two or more cylinders (8A, 8B). Also, as shown in Fig. 11(B), the arrangement of the first cylinder mechanism 9 and the second cylinder mechanism 15 may be changed so that the rod 81 of the first cylinder mechanism 9 and the rod 11 of the second cylinder mechanism 15 are located on both sides of the common imaginary center line CL.

[0033] According to each of the above-mentioned embodiments, when the first and second cylinder mechanisms 9, 15 of the compliance mechanism (7, 71-74) are first locked by supplying high-pressure fluid from the fluid pressure circuit 21, the mounting part (17, 117, 117', 217, 317) to which the holder 3, 3' is attached always returns to the original position relative to the support part 5. In other words, before holding and transporting the workpiece W, the holder attached to the mounting part can always be returned to the original position relative to the support part for position control. As a result, the position control of the holder becomes accurate. Then, when the holder holds the workpiece, if the compliance mechanism (7, 71-74) is put into a floating state by controlling the fluid pressure supplied from the fluid pressure circuit 21, the holder 3 moves following the workpiece, and the mounting part to which the holder is attached moves smoothly. As a result, the holder can hold the workpiece accurately at a position suitable for holding the workpiece. After the holders 3, 3' hold the workpiece, the compliance mechanisms (7, 71-74) are locked by the fluid pressure circuit 21 and the support 5 is moved, so that when the workpiece is transported, the mounting parts (17, 117, 117', 217, 317) to which the holders 3, 3' holding the workpiece are attached do not change position relative to the support 5. Therefore, the workpiece is not subjected to excessive vibrations, and the workpiece can be reliably held and moved.

[0034] More specifically, according to each of the above embodiments, the return force of the floating state can be adjusted arbitrarily by putting low-pressure fluid into the first and second cylinder mechanisms 9, 15. Even when the locked state is formed, it is possible to automatically and gently return to the reference position by adjusting the pressure of the fluid. In the floating state, the pressure of the fluid supplied to the first and second cylinder mechanisms 9, 15 may be adjusted according to the weight of the workpiece and the inclination of the installation state of the holding device. If the pressure of the fluid supplied to the first and second cylinder mechanisms 9, 15 is lowered to create a floating state, it is possible to deal with workpiece misalignment on either the left or right side, and the risk of falling can be reduced by making the return operation gentle. Due to this configuration, according to each of the above embodiments, it is also possible to increase the amount of workpiece misalignment absorbed. [Industrial Applicability]

[0035] According to the present invention, it is possible to provide a holding device equipped with a compliance mechanism that can reliably form a floating state and a locked state with a simple structure using a cylinder mechanism. [Explanation of symbols]

[0036] 1 Holding device 3 Holding part 5 Support part 51 Support 7 Compliance Organization 9 First cylinder mechanism 11 Rod 15 Second cylinder mechanism 17 Mounting part 18 Connection part 19 Slide mechanism 21 Fluid pressure circuit FS Fluid Drive Source

Claims

1. A holding part for holding a workpiece; A support portion that supports the holding portion; A holding device including a compliance mechanism disposed between the holding portion and the support portion, the compliance mechanism selectively forming a floating state in which the holding portion is displaced by a load applied to the holding portion to move the holding portion to a position where the workpiece can be held without being moved, and a locked state in which the position of the holding portion is prevented from being displaced relative to the support portion, The compliance mechanism includes a first cylinder mechanism including one or more cylinders having a rod and fixed to the support portion; a second cylinder mechanism including one or more cylinders fixed to a mounting portion having a rod and mounted to the holding portion; a connecting portion that connects the one or more rods of the first cylinder mechanism and the one or more rods of the second cylinder mechanism so as to be linearly movable along a common imaginary center line; a slide mechanism that is disposed between the support portion and the mounting portion and that allows the mounting portion to slide relative to the support portion along a parallel line that is parallel to the common virtual center line in the floating state; A holding device equipped with a compliance mechanism, comprising a fluid pressure circuit disposed between the first cylinder mechanism and the second cylinder mechanism and a fluid drive source, for selectively forming the floating state and the locked state.

2. 2. The holding device equipped with a compliance mechanism according to claim 1, wherein the fluid pressure circuit supplies a high-pressure fluid to the first cylinder mechanism and the second cylinder mechanism when realizing the locked state, and supplies a fluid of a lower pressure than the high pressure supplied to the first cylinder mechanism and the second cylinder mechanism to realize the locked state when realizing the floating state.

3. the support portion includes a frame that is driven and controlled, a support body that extends in a direction intersecting the frame, and a fixed portion that is provided on the support body and to which the first cylinder mechanism is fixed, the mounting portion includes a mounting portion main body that slides along the support body via the slide mechanism, and a fixed portion that is provided on the mounting portion main body and to which the second cylinder mechanism is fixed, The holding device with a compliance mechanism according to claim 1 , wherein the holding portion is attached to the mounting portion main body.

4. A holding device equipped with a compliance mechanism as described in claim 3, wherein a rotation mechanism for rotating the support body or the holding part is disposed between the frame and the support body or between the mounting body and the holding part.

5. At least one of the first cylinder mechanism and the second cylinder mechanism is configured with two or more of the cylinders arranged in parallel, A holding device equipped with a compliance mechanism as described in claim 1 or 2, wherein one or more of the rods of the first cylinder mechanism and one or more of the rods of the second cylinder mechanism are fixed to a connecting portion extending in a direction perpendicular to the common imaginary center line.

6. The fluid pressure circuit includes: First, a high-pressure fluid is supplied to the first and second cylinder mechanisms to lock the positional relationship between the mounting portion and the support portion; Then, a low-pressure fluid that is lower than the high-pressure fluid and enables the mounting portion to move relative to the support portion is supplied to the first and second cylinder mechanisms to form the floating state. The floating state is maintained at least until the holding portion holds the workpiece, A holding device equipped with a compliance mechanism according to any one of claims 1 to 5, wherein after the holding portion holds the workpiece and the workpiece is in a non-contact state with an adjacent workpiece, the high-pressure fluid is supplied to the first and second cylinder mechanisms to lock the positional relationship between the mounting portion and the support portion.

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