Gripping device and industrial robot

Abstract

To provide a gripping device and an industrial robot which can prevent fracture of a workpiece while keeping gripping force.SOLUTION: A gripping device 10A comprises: a palm part 30; a plurality of finger parts 32A which are arranged protruding around the palm part 30 and fall toward the palm part 30 when the palm part 30 is deformed in the thickness direction; and an elastic part 50A arranged in the finger part 32A which has higher flexibility in comparison with the finger part 32A and deformable in a direction opposite to the falling direction of the finger part 32A.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a gripping device and an industrial robot.

Background Art

[0002] As a gripping device for gripping a workpiece, a gripping device having a bag-shaped gripping body is known (Patent Document 1). In the gripping device according to Patent Document 1, the gripping body has a palm portion and a plurality of finger portions that protrude around the palm portion and fall toward the palm portion by deforming the palm portion in the thickness direction. By depressurizing the inside of the gripping body, the palm portion deforms in the thickness direction, and the plurality of finger portions elastically deform so as to fall toward the palm portion. Thereby, the plurality of finger portions come into contact with the surface of the workpiece, and the workpiece is gripped.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the gripping device according to Patent Document 1, when the plurality of finger portions are tilted and the workpiece is gripped by the plurality of finger portions, there is a possibility that damage such as a dent mark occurs on the workpiece. As one method of gripping the workpiece without leaving a dent mark, it is conceivable to make the finger portions flexible and enhance the followability to the workpiece shape. However, if the finger portions are made flexible, the gripping force decreases, and there is a risk that the workpiece will fall from the gripping device when the gripping device is moved while gripping the workpiece.

[0005] An object of the present invention is to provide a gripping device and an industrial robot that can prevent damage to a workpiece while maintaining a gripping force.

Means for Solving the Problems

[0006] The gripping device according to the present invention includes a palm portion, a plurality of finger portions provided to protrude around the palm portion and falling toward the palm portion by deforming the palm portion in the thickness direction, and higher flexibility than the finger portions, and an elastic portion provided on the finger portion so as to be deformable in a direction opposite to the direction in which the finger portion falls.

[0007] The industrial robot according to the present invention includes the above-described gripping device.

Effects of the Invention

[0008] According to the present invention, by providing the elastic portion, it is possible to grip the workpiece so as to sandwich it while the elastic portion follows the shape of the workpiece, and thus it is possible to prevent damage to the workpiece while maintaining the gripping force.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

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Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Modes for Carrying Out the Invention

[0010] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The following embodiments and modifications are examples of the present invention, and the present invention is not limited thereto. In the following description regarding the embodiments and each modification, the same components are denoted by the same reference numerals, and the description thereof will be omitted as appropriate.

[0011] 1. Embodiment (Overall Configuration) Fig. 1 shows the configuration of an industrial robot 12 to which a gripping device 10A according to the present embodiment is applied. The industrial robot 12 is an orthogonal robot and includes a rail 14, a moving body 16 that moves along the rail 14, and an air cylinder 18 fixed to the moving body 16. The rail 14 is provided so as to be movable in the Y-axis direction in the figure.

[0012] The air cylinder 18 has a cylinder tube 19 and a piston rod 20 provided so as to be able to advance and retreat with respect to the cylinder tube 19. Pipes 21 and 22 are provided on the cylinder tube 19. By supplying and exhausting gas through the pipes 21 and 22, the piston rod 20 can advance and retreat with respect to the cylinder tube 19. A gripping device 10A is provided at the tip of the piston rod 20 via a detachable portion 24 connected to an adapter plate 23. The adapter plate 23 is fixed to the tip of the piston rod 20 by bolts (not shown).

[0013] The industrial robot 12 can grip the workpiece W placed on the horizontal base 26 with the gripping device 10A and move in the X-axis, Y-axis, and Z-axis directions.

[0014] FIG. 2 shows a partial cross-sectional view of the gripping device 10A. FIG. 2 shows a state in which the gripping device 10A is removed from the detaching / attaching portion 24. The gripping device 10A includes a gripping body 28 attached to the piston rod 20 via the detaching / attaching portion 24. The gripping body 28 can be formed of a material having airtightness, elasticity, and flexibility, such as natural rubber, synthetic rubber, various elastomers, etc. The material of the gripping body 28 does not necessarily have to be a single type of material, and a composite material combining different types of materials may also be used. The hardness measured according to the JIS K6253 durometer hardness test (type A) of the gripping body 28 is preferably about 60 to 90.

[0015] The gripping body 28 has a palm portion 30 and a plurality of finger portions 32A provided to protrude around the palm portion 30. The palm portion 30 has a substantially disk shape. The finger portions 32A are integrally formed with the palm portion 30 and are provided in two so as to sandwich the palm portion 30. A predetermined interval is formed between the finger portions 32A. Three or more finger portions 32A may be provided radially so as to surround the palm portion 30.

[0016] The inner surface 34 of the finger portion 32A is integrally formed with the palm portion 30. The finger portion 32A is solid. The material of the finger portion 32A may be the same as or different from the material of the palm portion 30, and furthermore, it does not have to be uniform, and may contain additives such as a composite material combining different types of materials or a filler.

[0017] When a force acts on the palm portion 30 of the gripping body 28 and the palm portion 30 is deformed in the thickness direction (Z direction), the inner surface 34 is pulled by the palm portion 30. As a result, as shown in FIG. 3, the finger portion 32A elastically deforms so as to fall toward the palm portion 30.

[0018] The force for deforming the palm part 30 in the thickness direction (Z direction) is applied to the palm part 30 using gas. The deformation of the palm part 30 using gas will be specifically described with reference to FIGS. 2 and 3.

[0019] The gripping main body 28 is formed in a bag shape having an opening on the surface opposite to the surface on which the palm part 30 and the finger part 32A are formed. The opening of the gripping main body 28 is sealed by the case 40, and an internal space 29 is formed by the inner surface of the gripping main body 28 and the case 40. The gripping main body 28 and the case 40 are fixed by a band 41 wound around the outer periphery of the gripping main body 28.

[0020] The case 40 is preferably made of a metal such as stainless steel or a hard resin such as plastic. The case 40 has a cylindrical part 42, an upper part 43 provided at the upper end of the cylindrical part 42, and a joint 44 provided on the upper part 43. The cylindrical part 42 is a cylindrical member. The upper part 43 is a disk-shaped member. The cylindrical part 42 and the upper part 43 are integrally formed. A through hole 45 penetrating in the thickness direction is provided at the center of the upper part 43. The joint 44 communicates with the through hole 45. The joint 44 is screwed to the upper part 43 via a sealing material 46. The joint 44 is detachably connected to the detachable part 24 with one touch.

[0021] The detachable part 24 is a one-touch joint, one end of which is connected to the adapter plate 23 and the other end of which is connected to the joint 44. The detachable part 24 is connected to the joint 44 when the joint 44 is inserted in the insertion direction, and the connection with the joint 44 is released when the release part 47 is pushed in the insertion direction. The detachable part 24 is not limited to a one-touch joint and may be a joint connected to the joint 44 by a screw.

[0022] An air supply and exhaust port 48 is provided on the circumferential surface of the attaching / detaching portion 24. The air supply and exhaust port 48 is connected to one end of a pipe (not shown). The other end of this pipe is connected to a vacuum pump via, for example, a three-way valve. The three-way valve has a vacuum port, an air supply and exhaust port, and an air release port. The vacuum port is connected to the vacuum pump, the air supply and exhaust port is connected to the gripping device 10A, and the air release port is connected to the atmospheric pressure space. Through the pipe connected to the air supply and exhaust port 48, gas flows from the internal space 29 to the vacuum pump and from the atmospheric pressure space to the internal space 29. The attaching / detaching portion 24 is fixed to the adapter plate 23 by screwing bolts through mounting holes (not shown) provided on the top surface into the adapter plate 23.

[0023] When gas is sucked from the internal space 29 of the gripping body 28 using a vacuum pump, the palm portion 30 is pulled in the thickness direction (Z direction) together with the gas in the internal space 29. That is, a force that deforms the palm portion 30 in the thickness direction (Z direction) is applied to the palm portion 30. Thus, in this embodiment, the palm portion 30 is deformed in the thickness direction using gas.

[0024] The gripping device 10A includes an elastic portion 50A having higher flexibility than the finger portion 32A. The elastic portion 50A is provided on the finger portion 32A so as to be deformable in a direction opposite to the direction in which the finger portion 32A falls. With reference to FIG. 4, the deformation of the elastic portion 50A will be described in detail.

[0025] FIG. 4 shows a cross-sectional view taken along line IV-IV shown in FIG. 2. The finger portion 32A has a base portion 35 extending from the palm portion 30 (see FIG. 2) and a pair of protrusions 36A, 37A protruding from the base portion 35. The outer shapes of the base portion 35 and the pair of protrusions 36A, 37A can be appropriately selected, and for example, may be a rectangular parallelepiped, a quadrangular prism, a triangular prism, a cylinder, a quadrangular pyramid, a frustum of a quadrangular pyramid, a frustum of a cone, or the like.

[0026] The pair of protrusions 36A, 37A are arranged at intervals from each other when viewed in the direction in which the finger portion 32A falls, and a cavity is formed between the pair of protrusions 36A, 37A.

[0027] The elastic part 50A is formed in a bag shape and is put on the finger part 32A so as to cover the pair of protrusions 36A and 37A. Since there is a cavity between the pair of protrusions 36A and 37A, the elastic part 50A can be deformed so as to enter between the pair of protrusions 36A and 37A. Thus, the elastic part 50A can be deformed in a direction opposite to the direction in which the finger part 32A falls down.

[0028] FIG. 5 shows a partial cross-sectional view of the gripping device 10A in a state of gripping the workpiece W, and FIG. 6 shows a perspective view of the gripping device 10A in a state of gripping the workpiece W. When the workpiece W is disposed between the elastic parts 50A and the palm part 30 is deformed in the thickness direction, the finger part 32A falls toward the palm part 30 and the elastic part 50A is deformed while following the shape of the workpiece W, and the workpiece W is gripped so as to be sandwiched. Therefore, it is possible to prevent damage to the workpiece W while maintaining the gripping force.

[0029] The followability to the shape of the workpiece W is affected by a combination of the material properties (e.g., flexibility, viscoelasticity, and hardness) of the elastic part 50A and the mechanical structure (e.g., thickness and a structure that contributes to deformation such as a bellows). The material properties and mechanical structure of the elastic part 50A can be appropriately selected according to the required followability.

[0030] On the surface of the elastic part 50A, an anti-slip such as a rib may be provided. In this case, the frictional force between the elastic part 50A and the workpiece W is improved, and it is possible to prevent the workpiece W from falling off the gripping device 10A.

[0031] When the elastic part 50A is in a state of being removed from the finger part 32A, it is smaller than the outer shape of the finger part 32A and is put on the finger part 32A in an expanded state. Therefore, the elastic part 50A can be easily removed. Thus, when the elastic part 50A is damaged or the like, the elastic part 50A can be easily replaced.

[0032] An annular groove 38 is formed on the outer peripheral surface of the base portion 35 in the finger portion 32A, and the elastic portion 50A is hung on the annular groove 38. Therefore, it is possible to prevent the elastic portion 50A from falling off from the finger portion 32A, and it is possible to more reliably prevent the workpiece W from falling off from the gripping device 10A.

[0033] (Operation and Effect) The operation and effect of the industrial robot 12 provided with the gripping device 10A configured as described above will be described. Note that the conditions shown below are an example. As shown in FIG. 1, the industrial robot 12 takes as the origin the state where the piston rod 20 is retracted into the cylinder tube 19 and the air cylinder 18 is contracted. In the gripping device 10A, in the initial state, the pressure in the internal space 29 (see FIG. 2) of the gripping body 28 is the atmospheric pressure. That is, the three-way valve is in a state where the air supply / discharge port is blocked from the vacuum port and is connected to the atmosphere release port.

[0034] The industrial robot 12 positions the gripping device 10A on the vertical line of the workpiece W placed on the base 26 by moving the moving body 16 along the rail 14. Next, the industrial robot 12 extends the air cylinder 18 until the finger portion 32A reaches the side surface of the workpiece W by the piston rod 20 advancing from the cylinder tube 19.

[0035] Next, the three-way valve is switched to a state where the air supply / discharge port is blocked from the atmosphere release port and is connected to the vacuum port. As a result, the gripping device 10A sucks the gas in the gripping body 28 through the pipe, and reduces the pressure in the internal space 29 of the gripping body 28 to, for example, -0.03 MPa or less.

[0036] As shown in FIG. 5, the palm portion 30 deforms in the thickness direction so as to be sucked in. As the palm portion 30 deforms in the thickness direction, the inner surface 34 of the finger portion 32A is pulled toward the center of the palm portion 30. Then, the finger portion 32A elastically deforms so as to fall toward the palm portion 30. As a result, the elastic portion 50A comes into contact with the surface of the workpiece W. As described above, the gripping device 10A grips the workpiece W by decompressing the inside of the gripping body 28.

[0037] Next, the industrial robot 12 can lift the workpiece W from the base 26 by retracting the piston rod 20 into the cylinder tube 19 to contract the air cylinder 18. Further, the industrial robot 12 can freely move the workpiece W in the horizontal direction by the moving body 16 moving along the rail 14 or the rail 14 moving in the Y-axis direction.

[0038] After moving to the desired location, the industrial robot 12 extends the air cylinder 18 until the workpiece W contacts the base 26 by the piston rod 20 protruding from the cylinder tube 19. Next, the three-way valve is switched to a state where the air supply and exhaust port is blocked from the vacuum port and connected to the atmosphere release port. Then, gas flows into the internal space 29 of the gripping body 28 through the pipe from the atmosphere release port. As the pressure in the internal space 29 of the gripping body 28 returns to atmospheric pressure, the palm portion 30 is pushed out and returns to its original state. As the palm portion 30 returns to its original state, the finger portion 32A opens and releases the workpiece W.

[0039] Next, the industrial robot 12 separates the gripping device 10A from the workpiece W by retracting the piston rod 20 into the cylinder tube 19 to contract the air cylinder 18. In the above manner, the industrial robot 12 can move the workpiece W placed on the base 26 to a desired position by gripping it with the gripping device 10A.

[0040] The gripping device 10A includes an elastic portion 50A, so that the finger portion 32A falls toward the palm portion 30 and the elastic portion 50A deforms while following the shape of the workpiece W, and grips the workpiece W so as to sandwich it. Therefore, it is possible to prevent damage to the workpiece W while maintaining the gripping force.

[0041] The gripping device 10A is suitable when sequentially gripping a plurality of flexible, easily breakable, and non-uniformly shaped objects typified by food.

[0042] 2. Modification Example 1 Referring to FIG. 7, the gripping device 10B according to Modification 1 of the above embodiment will be described. FIG. 7 shows a cross-sectional view of the gripping device 10B corresponding to FIG. 4.

[0043] In Modification 1, the elastic part 50B is different from the above embodiment in that it is not covered on the finger part 32A but is stretched like a squeegee between the pair of protrusions 36A and 37A. Also in Modification 1, the elastic part 50B has higher flexibility than the finger part 32A and is provided on the finger part 32A so as to be deformable in a direction opposite to the direction in which the finger part 32A falls. Although not shown, when the workpiece W is arranged between the elastic parts 50B and the palm part 30 is deformed in the thickness direction, the finger part 32A falls toward the palm part 30 and the elastic part 50B deforms while following the shape of the workpiece W, and the workpiece W is gripped so as to be sandwiched. Therefore, it is possible to prevent damage to the workpiece W while maintaining the gripping force.

[0044] The elastic part 50B may be integrally formed with the pair of protrusions 36A and 37A.

[0045] Also in Modification 1, the material properties and mechanical structure of the elastic part 50B can be appropriately selected according to the required followability. A slip prevention such as a rib may be provided on the surface of the elastic part 50B.

[0046] 3. Modification 2 Referring to FIG. 8, the gripping device 10C according to Modification 2 of the above embodiment will be described. FIG. 8(a) shows a cross-sectional view of the gripping device 10C corresponding to FIG. 4, and FIG. 8(b) shows a cross-sectional view taken along line VIIB-VIIB shown in FIG. 8(a).

[0047] In Modification 2, the elastic part 50A in the above-described embodiment and the elastic part 50B in Modification 1 are provided. That is, the gripping device 10C has an elastic part 50B as a first elastic film attached to the finger part 32A and an elastic part 50A as a second elastic film laminated on the elastic part 50B. Also in Modification 2, when the workpiece W is disposed between the elastic parts 50A and the palm part 30 is deformed in the thickness direction, the finger part 32A falls toward the palm part 30 and the elastic parts 50A and 50B are deformed while following the shape of the workpiece W, and the workpiece W is gripped so as to be sandwiched. Therefore, it is possible to prevent damage to the workpiece W while maintaining the gripping force.

[0048] In the example shown in FIG. 8, a gap is provided between the elastic part 50A and the elastic part 50B, but the elastic part 50A and the elastic part 50B may be in contact with each other. When the elastic part 50A and the elastic part 50B are in contact with each other, the elastic part 50A and the elastic part 50B may be entirely adhered to each other or may be locally adhered in a pattern. When locally adhering, a pattern may be provided on the surface of the elastic part 50A according to the shape of the adhesion part.

[0049] 4. Modification 3 With reference to FIG. 9, a gripping device 10D according to Modification 3 of the above-described embodiment will be described. FIG. 9(a) shows a cross-sectional view of the gripping device 10D corresponding to FIG. 4, and FIG. 9(b) shows a cross-sectional view taken along line VIIIB-VIIIB shown in FIG. 9(a).

[0050] In Modification 3, the finger part 32D has a columnar part 36D extending from the base part 35 and a plate-like part 37D provided at the tip of the columnar part 36D, instead of the pair of protruding parts 36A and 37A (see FIG. 4 etc.) of the finger part 32A in the above-described embodiment. The plate-like part 37D is formed in a circular shape, for example.

[0051] The columnar part 36D supports the plate-like part 37D away from the base part 35. The cross-section of the columnar part 36D is smaller than the cross-sections of the base part 35 and the plate-like part 37D, and a cavity is formed between the base part 35 and the plate-like part 37D. That is, a cavity is formed around the columnar part 36D.

[0052] The elastic part 50A is covered on the finger part 32D so as to cover the columnar part 36D and the plate-like part 37D. Since there is a cavity between the base part 35 and the plate-like part 37D, the elastic part 50A can be deformed so as to enter between the columnar part 36D and the plate-like part 37D. In this way, the elastic part 50A can be deformed in a direction opposite to the direction in which the finger part 32D falls.

[0053] When the work W is arranged between the elastic parts 50A and the palm part 30 is deformed in the thickness direction, the finger part 32D falls toward the palm part 30 and the elastic part 50A deforms while following the shape of the work W, and grips the work W so as to sandwich it. Therefore, it is possible to prevent damage to the work W while maintaining the gripping force.

[0054] 5. Modification Example 4 Referring to FIG. 10, the gripping device 10E according to Modification Example 4 of the above embodiment will be described. In FIG. 10, a cross-sectional view of the gripping device 10E is shown corresponding to FIG. 4.

[0055] In Modification Example 4, the finger part 32E has a pair of protrusions 36E, 37E protruding from the base part 35 and a columnar part 39E provided between the pair of protrusions 36E, 37E. The columnar part 39E extends from the base part 35 along the pair of protrusions 36E, 37E. The protrusion 36E and the columnar part 39E are arranged at intervals from each other when viewed in the direction in which the finger part 32E falls. Similarly, the protrusion 37E and the columnar part 39E are arranged at intervals from each other. That is, cavities are formed between the protrusion 36E and the columnar part 39E, and between the protrusion 37E and the columnar part 39E.

[0056] The elastic part 50A is covered on the finger part 32E so as to cover the pair of protrusions 36E, 37E and the columnar part 39E. Since there are cavities between the protrusion 36E and the columnar part 39E, and between the protrusion 37E and the columnar part 39E, the elastic part 50A can be deformed so as to enter between the protrusion 36E and the columnar part 39E, and between the protrusion 37E and the columnar part 39E. In this way, the elastic part 50A can be deformed in a direction opposite to the direction in which the finger part 32E falls.

[0057] When the workpiece W is placed between the elastic portions 50A and the palm portion 30 is deformed in the thickness direction, the finger portion 32E falls toward the palm portion 30 and the elastic portion 50A deforms while following the shape of the workpiece W, and the workpiece W is gripped so as to be sandwiched. Therefore, it is possible to prevent damage to the workpiece W while maintaining the gripping force.

[0058] 6. Modification Example 5 Referring to FIG. 11, the gripping device 10F according to Modification Example 5 of the above embodiment will be described. FIG. 11(a) shows a cross-sectional view of the gripping device 10F corresponding to FIG. 4, and FIG. 11(b) shows a cross-sectional view taken along line XB-XB shown in FIG. 11(a).

[0059] In Modification Example 5, the finger portion 32F has a groove forming portion 36F extending from the base portion 35. The groove forming portion 36F is formed with a U-shaped cross section, and a groove 37F is formed by the groove forming portion 36F. A cavity is formed by the groove 37F.

[0060] The elastic portion 50A is covered on the finger portion 32F so as to cover the groove forming portion 36F. Since the groove 37F of the groove forming portion 36F is a cavity, the elastic portion 50A can be deformed so as to enter the groove 37F. Thus, the elastic portion 50A can be deformed in a direction opposite to the direction in which the finger portion 32F falls.

[0061] When the workpiece W is placed between the elastic portions 50A and the palm portion 30 is deformed in the thickness direction, the finger portion 32F falls toward the palm portion 30 and the elastic portion 50A deforms while following the shape of the workpiece W, and the workpiece W is gripped so as to be sandwiched. Therefore, it is possible to prevent damage to the workpiece W while maintaining the gripping force.

[0062] 7. Modification Example 6 Referring to FIGS. 12 and 13, the gripping device 10G according to Modification Example 6 of the above embodiment will be described. FIG. 12 shows a cross-sectional view of the gripping device 10G corresponding to FIG. 4, and FIG. 13 shows a cross-sectional view of the gripping device 10G corresponding to FIG. 2.

[0063] In Modification 6, a plurality of through holes 37G penetrating in the direction in which the finger portion 32G falls are formed in the finger portion 32G, and a cavity is formed by the through holes 37G. The elastic portion 50A is covered on the finger portion 32G so as to cover the through holes 37G. Since the through holes 37G are hollow, the elastic portion 50A can be deformed so as to enter the through holes 37G. Thus, the elastic portion 50A can be deformed in a direction opposite to the direction in which the finger portion 32G falls.

[0064] As shown in FIG. 13, the gripping device 10G is suitable for gripping a workpiece W having a plurality of convex portions. When the workpiece W is disposed between the elastic portions 50A and the palm portion 30 is deformed in the thickness direction, the finger portion 32G falls toward the palm portion 30 and the elastic portion 50A deforms while following the shape of the workpiece W, and grips the workpiece W so as to sandwich it. Therefore, it is possible to prevent damage to the workpiece W while maintaining the gripping force.

[0065] In the example shown in FIG. 12, four through holes 37G are formed in the finger portion 32G, but the number of through holes 37G can be appropriately changed and may be one, two, three, or five or more.

[0066] 8. Modification 7 With reference to FIG. 14, the gripping device 10H according to Modification 7 of the above embodiment will be described. FIG. 14(a) shows a cross-sectional view of the gripping device 10H corresponding to FIG. 4, and FIG. 14(b) shows a cross-sectional view taken along line XIIIB-XIIIB shown in FIG. 14(a).

[0067] In Modification 7, the finger portion 32H has three columnar portions 36H extending from the base portion 35. The columnar portions 36H are arranged at intervals from each other, and a cavity is formed by the plurality of columnar portions 36H. Two of the columnar portions 36H are located on the side where the finger portion 32H falls rather than the other columnar portions 36H, and the entry of the elastic portion 50A into the cavity from between the two columnar portions 36H is not inhibited by the other columnar portions 36H.

[0068] The elastic part 50A is covered on the finger part 32H so as to cover a plurality of columnar parts 36H. Since the inside of the columnar part 36H is hollow, the elastic part 50A can be deformed so as to enter between two columnar parts 36H located on the side where the finger part 32H falls. In this way, the elastic part 50A can be deformed in a direction opposite to the direction in which the finger part 32H falls.

[0069] When the workpiece W is placed between the elastic parts 50A and the palm part 30 is deformed in the thickness direction, the finger part 32H falls toward the palm part 30 and the elastic part 50A deforms while following the shape of the workpiece W, and grips the workpiece W so as to sandwich it. Therefore, it is possible to prevent damage to the workpiece W while maintaining the gripping force.

[0070] 9. Modification Example 8 Referring to FIG. 15, the gripping device 10I according to Modification Example 8 of the above embodiment will be described. In FIG. 15, a cross-sectional view of the gripping device 10I is shown corresponding to FIG. 4.

[0071] In Modification Example 8, the gripping device 10I includes a pair of protruding members 36I and 37I protruding from the finger part 32I. The pair of protruding members 36I and 37I are inserted into the finger part 32I with a space therebetween when viewed in the direction in which the finger part 32I falls, and a cavity is formed between the pair of protruding members 36I and 37I. The pair of protruding members 36I and 37I have higher rigidity than the finger part 32I. The pair of protruding members 36I and 37I are made of, for example, metal such as stainless steel or hard resin such as plastic.

[0072] The elastic part 50A is covered so as to cover the pair of protruding members 36I and 37I together. That is, the elastic part 50A is provided on the finger part 32I via the pair of protruding members 36I and 37I. Since the space between the pair of protruding members 36I and 37I is hollow, the elastic part 50A can be deformed so as to enter between the pair of protruding members 36I and 37I. In this way, the elastic part 50A can be deformed in a direction opposite to the direction in which the finger part 32I falls.

[0073] When the workpiece W is placed between the elastic portions 50A and the palm portion 30 is deformed in the thickness direction, the finger portions 32I fall toward the palm portion 30 and the elastic portions 50A are deformed while following the shape of the workpiece W, and grip the workpiece W so as to sandwich it. Therefore, it is possible to prevent damage to the workpiece W while maintaining the gripping force.

[0074] Since the pair of protruding members 36I and 37I have higher rigidity than the finger portions 32I, the deformation of the pair of protruding members 36I and 37I is small. Therefore, the insertability between a plurality of workpieces W arranged densely can be improved. Since the deformation of the pair of protruding members 36I and 37I when gripping the workpiece W is small, it can contribute to an improvement in the gripping force.

[0075] As described above, the embodiments and Modification Examples 1 to 8 have been described. However, the present invention is not limited to the above-described embodiments and Modification Examples 1 to 8, and can be appropriately changed within the scope of the gist of the present invention. The embodiments and Modification Examples 1 to 8 may be combined, or Modification Examples 1 to 8 may be combined with each other. For example, combinations of the gripping device 10H shown in FIG. 14 and the gripping device 10I shown in FIG. 15, combinations of the gripping device 10F shown in FIG. 11 and the gripping device 10G shown in FIG. 12, and combinations of the gripping device 10C shown in FIG. 8 and the gripping device 10D shown in FIG. 9 are possible.

[0076] The elastic portions 50A and 50B only need to be deformable in a direction opposite to the direction in which the finger portions 32A, 32D to 32I fall, and a cavity is not essential. For example, in the above embodiment, a member (for example, sponge) having higher flexibility than the finger portion 32A may be disposed between the pair of protrusions 36A and 37A in the finger portion 32A.

[0077] Further, the elastic portions 50A and 50B may be formed of a single material, or may be formed by combining a plurality of materials including a rigid member.

Description of Reference Numerals

[0078] 10A to 10I Gripping device 12 Industrial robot 30 Palm part 32A, 32D - 32I Finger parts 36I Protruding member 37I Protruding member 38 Annular groove 50A, 50B Elastic parts

Claims

1. A palm part, a plurality of finger parts provided to protrude around the palm part and falling toward the palm part by deforming the palm part in the thickness direction, and an elastic part provided on the finger parts so as to be deformable in a direction opposite to the direction in which the finger parts fall and having higher flexibility than the finger parts are provided, wherein the elastic part is formed in a bag shape and covers the finger parts in an expanded state, a gripping device.

2. An annular groove is formed on the outer peripheral surface of the finger part, and the elastic part is hung on the annular groove, the gripping device according to Claim 1.

3. The elastic part has a first elastic film attached to the finger part and a second elastic film overlapped on the first elastic film, the gripping device according to Claim 1 or 2.

4. A palm part, a plurality of finger parts provided to protrude around the palm part and falling toward the palm part by deforming the palm part in the thickness direction, an elastic part provided on the finger parts so as to be deformable in a direction opposite to the direction in which the finger parts fall and having higher flexibility than the finger parts, and a protruding member provided to protrude from the finger parts and having higher rigidity than the finger parts are provided, wherein the elastic part is provided on the finger parts via the protruding member, a gripping device.

5. An industrial robot including the gripping device according to any one of Claims 1 to 4.

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