WO2019167652A1

WO2019167652A1 - Gripping device and industrial robot

Info

Publication number: WO2019167652A1
Application number: PCT/JP2019/005381
Authority: WO
Inventors: 至波多野; 浩和新田; 俊介岩田
Original assignee: ニッタ株式会社
Priority date: 2018-02-28
Filing date: 2019-02-14
Publication date: 2019-09-06
Also published as: JP2019147237A; TW201936347A; JP7112210B2

Abstract

Provided is a gripping device and an industrial robot capable of gripping a workpiece more reliably without using particulate matter. The present invention is provided with: a palm part 30; a plurality of finger parts 32A that are provided around the palm part 30 so as to project and that come down toward the palm part 30 by deforming the palm part 30 in the thickness direction; a connection part 38 formed at a position that encloses the outer periphery of the palm part 30 and that is on the opposite side to the side where the finger parts 32A are formed, so as to be connected to a case 36; a high-strength part 42 that is disposed between the palm part 30 and the connection part 38, that has a predetermined length in the thickness direction of the palm part 30 from the outer periphery of the palm part 30, and that is less likely to be deformed than the palm part 30; the case 36 that is connected to the connection part 38 and that is in contact with the base end of the high-strength part 42; and a cover part 72A that covers at least a part of the surrounding of a portion except the palm part 30 and the finger parts 32A.

Description

Gripping device and industrial robot

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

As a gripping device for gripping a workpiece, 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, There is disclosed a gripping device including a bag-shaped gripping body having a granular material housed in the gripping body (Patent Document 1). In the gripping device, by reducing the pressure in the gripping main body, the palm is deformed elastically so that the palm is deformed in the thickness direction and the finger is tilted toward the palm. Since this gripping device has a plurality of finger parts, it can grip a workpiece of different sizes and shapes for general use, and it can be gripped simply by reducing the pressure inside the gripping body. Since it is not necessary to press strongly against the workpiece, a flexible workpiece such as food can be gripped without being damaged.

JP 2017-185553 A

However, the gripping device of Patent Document 1 has a problem that when the grip body is ruptured due to deterioration or breakage, the granular material filled in the grip body is scattered to contaminate the workpiece. Since the granular material deteriorates due to the density change accompanying the Jamming transition, there is a problem that it cannot be used stably.

An object of the present invention is to provide a gripping device and an industrial robot that can grip a workpiece more reliably without using a granular material.

A gripping device according to the present invention is provided with a palm, a plurality of fingers that protrude around the palm, and are tilted toward the palm by deforming the palm in the thickness direction, and the finger Formed at a position surrounding the outer edge of the palm part on the opposite side of the side where the part is formed, and connected to a case, provided between the palm part and the connecting part, and provided at the outer edge of the palm part A high-strength portion that has a predetermined length in the thickness direction of the palm portion and is less likely to be deformed than the palm portion; and the case that is connected to the connection portion and contacts a proximal end of the high-strength portion; A cover portion covering at least a part of the periphery of the portion excluding the palm portion and the finger portion.

The industrial robot according to the present invention is provided with the gripping device.

According to the present invention, the high strength portion prevents the outer periphery of the palm portion from contracting, and the palm portion deforms in the thickness direction, thereby deforming the finger portion toward the palm portion and gripping the work. Therefore, the workpiece can be gripped more reliably without using powder. The gripping device can prevent foreign matter from accumulating in the uneven portion by covering the uneven portion on the surface with the cover portion.

It is a schematic diagram which shows the example of the industrial robot to which the holding | grip apparatus which concerns on this embodiment is applied. It is a fragmentary longitudinal cross-section which shows the structure of the holding | gripping apparatus which concerns on 1st Embodiment. It is a perspective view showing composition of a grasping device concerning a 1st embodiment. It is a longitudinal cross-sectional view which shows the structure of the case which concerns on 1st Embodiment. It is a perspective view which shows the use condition of the holding | gripping apparatus which concerns on 1st Embodiment. It is a fragmentary longitudinal cross-section which shows the use condition of the holding | gripping apparatus which concerns on 1st Embodiment. It is a perspective view which shows the modification of the cover which concerns on 1st Embodiment. It is a fragmentary sectional view which shows the structure of the detection part which concerns on 2nd Embodiment. It is a fragmentary sectional view showing modification (1) of a detection part concerning a 2nd embodiment. It is a fragmentary sectional view which shows the modification (2) of the detection part which concerns on 2nd Embodiment. It is a fragmentary longitudinal cross-section which shows the structure of the holding | gripping apparatus which concerns on 3rd Embodiment. It is a perspective view which shows the structure of the holding | maintenance main body which concerns on 3rd Embodiment. It is a perspective view which shows the modification (1) of a holding | gripping apparatus, FIG. 13A is an example in which a cover part is a separate type, FIG. It is a perspective view which shows the modification (2) of a holding | gripping apparatus, FIG. 14A is an example in which a cover part is a separate type, FIG.

Since the high-strength part is harder to deform than the palm part, when the inner surface side of the palm part is depressurized, the palm part deforms in the thickness direction without contracting the outer periphery. Therefore, the gripping main body is elastically deformed so that the finger part falls down toward the palm part, so that the workpiece can be gripped more reliably without using the powdery body.

The high-strength part is formed to have higher mechanical strength than the palm part. The high-strength portion includes a case where it is separate from the palm portion, the finger portion, and the connection portion, and a case where it is integral.

When the high-strength part is integrated with the palm part, the finger part, and the connection part, the high-strength part may be provided uniformly around the palm part or may be provided partially. Specifically, the high-strength part may be thicker than the palm part. In this case, the thickness of the high-strength portion is not limited to being uniform, and may be partially thick. The case of being partially thick includes the case of being partially in the circumferential direction of the palm part and the case of being partially in a direction parallel to the thickness direction of the palm part. The high strength portion may be formed of a material having higher mechanical strength than the palm portion. The material having high mechanical strength includes a material having the same quality as the palm but having high hardness, a material different from the palm, a case of containing an additive such as a filler, and a case of a composite material thereof. The high-strength portion contacts a part of the case at the proximal end. The high-strength portion includes a case where the base end is in surface contact with the case and a case where the base portion is in line contact. The proximal end preferably has a contact surface that contacts the case. When the case includes an upper case and a lower case, the upper case may contact the contact surface, or the lower case may contact the contact surface. The high-strength portion is a certain region from the proximal end to the distal end connected to the palm portion. The tip is the boundary between the high-strength part and the palm part, but is not limited to the case where it can be clearly visually recognized. The tip is preferably a fulcrum when the palm is deformed in the thickness direction.

The palm part and the finger part are elastically deformed parts when the gripping device grips the workpiece. It can also be said that the part excluding the palm part and the finger part is a part of the gripping device other than elastic deformation.

The periphery of the part excluding the palm part and the finger part is not limited to the case of contacting the surface of the part, but includes the case where it is separated from the surface of the part by a predetermined distance.

The cover part has a first cover that covers at least a part of the periphery of the connection part. The first cover includes a case where the first cover is in contact with the connecting portion, a case where there is a predetermined gap between the first cover and the case where there is another member between the connecting portion.

The cover portion has a second cover that covers at least a part of a detachable portion that is detachably connected to the case. The second cover portion includes a case where the second cover portion is in contact with the detachable portion, a case where there is a predetermined gap between the second cover portion and the detachable portion, and a case where there is another member between the detachable portion.

The detection part which detects the surrounding state is provided in the cover part. The surrounding state includes a case where it is detected that the distance to the detection target is within a predetermined range and a case where environmental information such as temperature, humidity, and brightness is detected. A contact sensor, a non-contact sensor, or the like is applied to the detection unit that detects that the distance to the detection target is within a predetermined range.

1. First Embodiment Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
(overall structure)
FIG. 1 shows a configuration of an industrial robot 12 to which the 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 that is fixed to the moving body 16. The rail 14 is provided so as to be movable in the Y-axis direction in the drawing.

The air cylinder 18 has a cylinder tube 19 and a piston rod 20 provided so as to be able to advance and retract with respect to the cylinder tube 19. The cylinder tube 19 is provided with

pipes

21 and 22. 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 10 A is provided at the tip of the piston rod 20 via an adapter plate 23. The adapter plate 23 is fixed to the tip of the piston rod 20 by a bolt (not shown).

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.

The gripping device 10 A includes a gripping main body 28 A connected to the piston rod 20. The grip body 28A can be formed of a material having airtightness and elasticity, for example, natural rubber or synthetic rubber. The hardness measured according to the JIS K6253 durometer hardness test (type A) of the gripping body 28A is preferably about 60 to 90.

As shown in FIG. 2, the gripping main body 28 A has a palm portion 30 and a plurality of finger portions 32 A provided so as to protrude around the palm portion 30. The palm 30 has a substantially disk shape. The finger portions 32 A are formed integrally with the palm portion 30, and five radial portions are provided so as to surround the palm portion 30. A predetermined interval is formed between the finger portions 32A. The finger portion 32 A has an inner surface 31 formed integrally with the palm portion 30. The outer shape of the finger 32A can be selected as appropriate, and may be, for example, a cylinder, a cone, a truncated cone, a triangular prism, a quadrangular prism, a triangular pyramid, a quadrangular pyramid, a quadrangular pyramid, a rectangular parallelepiped, or the like. In the case of the present embodiment, the finger portions 32A are configured in the same shape. The plurality of finger portions 32A need not all have the same shape, and may have different shapes.

In the gripping main body 28A, a connecting portion 38 is integrally formed at a position surrounding the outer edge of the palm portion 30 on the side opposite to the side where the finger portion 32A is formed. The connecting portion 38 has a cylindrical shape, and in the case of this figure, has a circular opening at the upper end. The gripping main body 28 A has an outer peripheral surface 34 curved in a direction protruding outward from the palm portion 30 toward the connection portion 38. The finger part 32A is solid. The material of the finger part 32A may be the same material as the other parts (the palm part 30 and the connection part 38) or a different material, and need not be even more uniform. Additives such as composite materials and fillers combining different materials May be included. The opening of the gripping main body 28 A is sealed by a case 36 inserted into the connection portion 38. The gripping main body 28 A and the case 36 are fixed by a band 65 wound around the outer periphery of the connection portion 38. The case 36 is detachably connected to the detachable portion 64.

The attachment / detachment portion 64 is a one-touch joint, and one end is connected to the adapter plate 23 provided at the tip of the piston rod 20 and the other end is connected to the joint 62 of the case 36. The detachable portion 64 is connected when the joint 62 is inserted in the insertion direction, and the connection is released when the release portion is pushed in the insertion direction. The detachable part 64 is not limited to a one-touch joint, and may be a joint connected to the joint 62 by a screw. The detachable portion 64 is provided with an air supply / exhaust port 73 on the peripheral surface. Although not shown, the air supply / exhaust port 73 is connected to one end of a pipe. The other end of the pipe is connected to a vacuum pump via a three-way valve, for example. The three-way valve has a vacuum port, a supply / exhaust port, and an atmosphere release port, and the vacuum port is connected to the vacuum pump, the supply / exhaust port is connected to the gripping device 10A, and the atmosphere release port is connected to the outside. Through the piping, gas flows from the inside of the gripping main body 28A to the outside and from the outside of the gripping main body 28A.

The grip body 28A includes a high-strength portion 42 that is less likely to deform in the thickness direction than the palm portion 30 between the connection portion 38 and the palm portion 30. The high-strength portion 42 is disposed in the internal space of the palm portion 30 of the grip body 28A. The high-strength portion 42 holds the grip body 28A so that the outer periphery of the palm portion 30 other than the palm portion 30, that is, the outer periphery of the palm portion 30 does not contract. The material of the high-strength portion 42 is sufficient if it does not deform under the reduced pressure of the grip body 28A, and for example, a hard resin or metal can be used. The material of the high-strength portion 42 is not necessarily uniform, and may be a composite material in which different materials are combined.

The high-strength portion 42 shown in the figure is a frame-like member having a guide hole 47 that receives the deformed palm portion 30 and a curved portion 46 outside the tip of the guide hole 47 in the axial direction on the finger portion 32A side. In the case of the present embodiment, the high-strength portion 42 is a cylindrical member and is tapered toward the tip as a whole. A bending portion 46 is provided on the finger portion 32A side of the high strength portion 42. The curved portion 46 has a convex shape toward the outside. The guide hole 47 is preferably the center of the high-strength portion 42 corresponding to the palm portion 30 and has an inner diameter that is substantially the same as that of the palm portion 30.

In the high-strength portion 42, the ratio of the outer diameter D to the guide hole 47 inner diameter d is preferably 1.0: 0.98 to 1.0: 0.6. For example, when the outer diameter D of the high-strength portion 42 is 80 mm and the inner diameter d is in the range of 48 to 78 mm, the finger portion 32A is elastically deformed more reliably toward the center of the palm portion 30.

Furthermore, it is preferable that the finger-side tip of the high-strength portion 42 is located on the outer side in the radial direction from the center position of the base end of the finger portion 32A in plan view. That is, when the length of the finger portion 32A in the radial direction is L, the tip on the finger portion side of the high-strength portion 42 is at the position where the distance T from the inside of the finger portion 32A is L / 2 or more. It is preferable to contact the proximal end. When the finger-side tip of the high-strength portion 42 is in contact with the proximal end of the finger portion 32A in the radial direction from the center position of the finger portion 32A (when T is smaller than L / 2), the finger portion 32A is It becomes difficult to elastically deform toward the center of the palm 30.

The gripping device 10A is provided with a cover portion 72A around the periphery of the palm portion 30 and the finger portion 32A. The cover portion 72 A includes a first cover 66 A that covers the periphery of the connecting portion 38 and a second cover 68 that covers the periphery of the detachable portion 64. The cover portion 72A is formed of a material softer than the case 36, for example, an elastic material such as resin or rubber. As the material of the cover portion 72A, a material excellent in cushioning properties, for example, a foam material may be used. The material of the cover portion 72A may be the same material as the gripping main body 28A or a different material, and need not be more uniform, and may include additives such as composite materials combining different materials and fillers. Further, the cover portion 72A may be made of foamed polystyrene or the like, so that if it should collide with another object, the cover part 72A may be crushed to absorb the impact applied to the object.

The first cover 66 A includes a cylindrical portion 69 that covers the periphery of the connection portion 38 around which the band 65 is wound, and an annular protrusion 71 provided at one end of the cylindrical portion 69. The annular protrusion 71 protrudes toward the central axis of the cylindrical portion 69. The second cover 68 is a cylindrical member that covers the detachable portion 64. The first cover 66A and the second cover 68 are arranged on the same axis and are overlapped so that there is no gap between the end portions.

As shown in FIG. 3, the second cover 68 has one slit 70A formed in the axial direction. The second cover 68 is elastically deformed by applying a force outward in the circumferential direction around the slit 70A, and the slit 70A is opened. By removing the outward force in the circumferential direction, the second cover 68 is elastically deformed and the slit 70A is closed. The second cover 68 is provided with a through hole that communicates with the air supply / exhaust port 73. The through hole is an upper part of the second cover 68 and penetrates in the thickness direction.

The attachment / detachment portion 64 is fixed to the adapter plate 23 by screwing a bolt (not shown) into the adapter plate 23 through an attachment hole 78 provided on the top surface.

As shown in FIG. 4, the case 36 is preferably made of a metal such as stainless steel or a hard resin such as plastic, and has a lower case 52 and an upper case 54. The lower case 52 includes a bottom portion 58 having a through hole 56 at the center, and a cylindrical portion 60 formed integrally with the outer edge of the bottom portion 58. The outer edge R of the bottom surface, which is the tip surface of the lower case 52, is chamfered. The chamfering can be applied by cutting the outer edge of the bottom surface into a square surface or a round surface. The size of the chamfering process is preferably small in order to prevent the connecting portion 38 from being locally deformed in the thickness direction.

The upper case 54 is a disk-shaped member, and has a through hole 59 provided so as to penetrate in the thickness direction and a joint 62 communicated with the through hole 59. The joint 62 is screwed to the upper case 54 via a seal material 57. The joint 62 is connected to the detachable portion 64 by one touch. The lower case 52 and the upper case 54 are integrated at the upper end of the cylindrical portion 60 via a seal material (not shown).

The first cover 66A is inserted into the joint 62, and the first cover 66A is mounted so as to cover the connection portion 38 and the case 36 from above. Next, the joint 62 is connected to the detachable portion 64 (FIG. 5). Subsequently, the slit 70 A is opened so as to cover the detachable portion 64, and the second cover 68 is attached around the detachable portion 64. As described above, the gripping device 10A to which the cover portion 72A is attached can be obtained.

(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. In addition, the conditions shown below are an example. The industrial robot 12 has the origin when the piston rod 20 is retracted into the cylinder tube 19 and the air cylinder 18 is contracted. In the gripping device 10A, the pressure in the gripping main body 28A is atmospheric pressure in the initial state. That is, the three-way valve is in a state where the vacuum port is shut off and the supply / exhaust port is connected to the atmosphere release port.

The industrial robot 12 positions the gripping device 10A on the vertical line of the workpiece W placed on the base 26 as the moving body 16 moves along the rail 14 (FIG. 1). Next, the industrial robot 12 extends the air cylinder 18 until the finger portion 32 A reaches the side surface of the workpiece W by the piston rod 20 advancing from the cylinder tube 19.

Next, the three-way valve is switched to a state where the air release port is shut off and the air supply / exhaust port is connected to the vacuum port. Thereby, the gripping device 10A sucks the gas in the gripping main body 28A through the pipe, and reduces the pressure in the gripping main body 28A to, for example, −0.03 MPa or less.

The grip body 28A maintains a state in which the shape of the outer peripheral surface 34 of the palm 30 is held by the high-strength portion 42. Then, the palm portion 30 is deformed in the thickness direction so as to be sucked into the guide hole 47 of the high-strength portion 42 (FIG. 6). As the palm portion 30 is deformed in the thickness direction, the inner surface 31 of the finger portion 32 A is pulled toward the center of the palm portion 30. Then, the finger part 32 A is elastically deformed so as to fall toward the palm part 30. Thereby, as for finger part 32A, inner surface 31 mainly contacts the work W surface. In the case of the cubic workpiece W shown in the figure, the finger portion 32A contacts the side surface of the workpiece W. As described above, the gripping device 10A grips the workpiece W by reducing the pressure inside the gripping main body 28A. The gripping device 10A exhibits a gripping force according to the pressure in the gripping body 28A. That is, the gripping force of the gripping device 10A increases as the pressure in the gripping main body 28A decreases.

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 and contracting the air cylinder 18. Furthermore, the industrial robot 12 can move the workpiece W freely in the horizontal direction by moving the moving body 16 along the rail 14 or moving the rail 14 in the Y-axis direction.

After moving to a desired location, the industrial robot 12 extends the air cylinder 18 until the workpiece W comes into contact with the base 26 by the piston rod 20 advancing from the cylinder tube 19. Next, the three-way valve is switched to a state in which the vacuum port is shut off and the supply / exhaust port is connected to the atmosphere release port. Then, the gas flows into the grip body 28A from the atmosphere release port through the pipe. As the pressure in the gripping main body 28A returns to atmospheric pressure, the palm 30 is pushed out of the guide hole 47 and returns to its original state. As the palm part 30 returns to the original state, the finger part 32A opens and the work W is released.

Next, the industrial robot 12 separates the gripping device 10 A from the workpiece W by retracting the piston rod 20 into the cylinder tube 19 and contracting the air cylinder 18. As described above, the industrial robot 12 can move to a desired position by gripping the workpiece W placed on the base 26 with the gripping device 10A.

The grip body 28A includes the finger portion 32A and the high-strength portion 42, so that the workpiece W can be gripped more reliably without using powder. Since the gripping device 10A does not use powder, even if the gripping main body 28A ruptures, the workpiece W is not contaminated.

The shape of the finger part 32 A is maintained not only when the tip of the finger part 32 A is downward, but also when the finger part 32 A is horizontally or upward. Therefore, the gripping device 10A can not only lift the workpiece W on the base 26 but also grip the workpiece W suspended on a vertical wall surface or ceiling. Since the finger portion 32A has higher rigidity than the powder after the jamming transition, the finger W can be gripped more reliably.

The gripping device 10A can grip the workpiece W by depressurizing the gripping main body 28A and reliably deforming the palm portion 30 in the thickness direction, so there is no need to press the gripping main body 28A against the workpiece W. Accordingly, the gripping device 10A can grip a soft work W such as food without being crushed, and thus can prevent the work W from being damaged.

The gripping main body 28A can change the deformation amount and gripping force of the finger portion 32A depending on the degree to which the inside is decompressed. Accordingly, the gripping device 10A can change the gripping force in accordance with the size and hardness of the workpiece W, so that versatility can be improved. Since the palm portion 30 is deformed in the thickness direction so as to be sucked into the guide hole 47, the finger portion 32 A is deformed to an acute angle toward the palm portion 30. Therefore, the gripping device 10A can grip a smaller workpiece W.

Since the finger portion 32A is deformed in the thickness direction while the palm portion 30 is in contact with the bending portion 46 because the bending portion 46 is formed in the high-strength portion 42, the finger portion 32A is continuous and loose. Transforms into Therefore, the gripping device 10A can grip the workpiece W softly. Incidentally, in the gripping device in which the bending portion is not formed in the high strength portion, the finger portion is deformed so as to buckle.

In the gripping device 10A, the surface of the case 36, the connection portion 38, and the detachable portion 64 are covered with the cover portion 72A, so the band 65 and the detachable portion 64 are not exposed. Accordingly, it is possible to prevent foreign matters from accumulating on the uneven portions of the band 65 and the detachable portion 64.

Since the hard case 36 and the detachable portion 64 are not exposed from the gripping main body 28A, it is possible to reduce the feeling of pressure given to the user. Therefore, the gripping device 10A can reduce a user's psychological burden when applied to an emphasis robot that performs a collaborative work by sharing a work area with the user.

The cover portion 72A is formed of a material having excellent cushioning properties, so that it is possible to reduce the impact given to the object when it collides with the object. By providing a gap between the cover portion 72A and the connecting portion 38 and the detachable portion 64, the cushioning property can be further enhanced.

The gripping device 10A can conceal the case 36 and the detachable portion 64 formed of different materials such as metal by providing the cover portion 72A formed of the same material and / or color as the grip body 28A, and the appearance is unified. can do.

(Modification)
In the case of the above embodiment, the cover 72A has been described with respect to the case where the first cover 66A and the second cover 68 are separate bodies, but the present invention is not limited to this. For example, as shown in FIG. 7, a cover portion 72B in which a first cover 66A and a second cover 68 are integrated may be used. The cover portion 72B has one slit 70B that penetrates the first cover 66A and the second cover 68 in parallel to the axial direction. Even after the cover portion 72B is attached to the detachable portion 64, the cover portion 72B can be attached around the connection portion 38 and the detachable portion 64 by opening the slit 70B so as to cover the connection portion 38 and the detachable portion 64. The gripping device 10B according to the present modification can obtain the same effect as that of the above embodiment by including the cover portion 72B.

In the case of the above-described embodiment, the case where the high-strength portion 42 is a cylindrical member has been described. However, the present invention is not limited to this, and for example, an oval shape, a polygonal shape, an elliptical shape or the like in plan view. It is good also as a member. The high-strength portion can appropriately change the outer shape in accordance with the shape of the gripping main body. The guide hole of the high-strength portion is not limited to a circular shape, and may be a polygonal shape.

The grip body may be formed of one kind of material, or may be formed by laminating a plurality of films formed of different materials. Further, the gripping main body may be formed of partially different materials. The thickness of the gripping main body may not be constant, and a thick part or a thin part may be partially provided.

2. Second Embodiment A second embodiment will be described with reference to the drawings. The same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted. As shown in FIG. 8, the gripping device according to the second embodiment includes a cover part 72 C provided with a detection part 61. The detection unit 61 shown in the figure is a tape-shaped switch sensor, and is wound around the outer periphery of the cylindrical portion 69 of the first cover 66B.

Although not shown, the detection unit 61 includes an outer electrode disposed on the radially outer side of the cylindrical portion 69 and an inner electrode disposed on the radially inner side, and is electrically connected to the circuit. When a load is applied to the bead 63, an outer electrode (not shown) contacts the inner electrode, and the circuit is closed. When the load applied to the bead 63 is removed, the outer electrode returns and the circuit opens. The detection unit 61 is attached to a guide unit 67 fixed to the outer periphery of the tube unit 69.

The guide portion 67 is fixed to an annular groove formed on the outer peripheral surface of the cylindrical portion 69. The guide part 67 is a belt-like member having a guide groove on the surface. The guide part 67 is wound around the surface of the cylinder part 69 and is fixed by an adhesive, a double-sided tape, a bolt and a nut, and the like.

When a load is applied to the bead 63 such as when the gripping device comes into contact with the object to be detected, the circuit closes and an abnormality is detected. When the gripping device detects an abnormality, it immediately stops the operation of the industrial robot. The gripping device can reduce the damage caused by the collision by detecting contact with the detection target object and stopping the operation of the industrial robot.

In the case of the present embodiment, the detection unit 61 is described as a switch, but the present invention is not limited to this. For example, the detection unit 61 may be a load sensor. The detection unit 61 may be a non-contact sensor, for example, a photoelectric sensor. When the detection unit 61 is a non-contact sensor, the gripping device can prevent contact with the detection target.

Although the detection part 61 demonstrated the case where it mounts | wears with the guide part 67 fixed to the cylinder part 69, this invention is not limited to this. For example, the cover portion 72D shown in FIG. 9 has a first cover 66C in which a guide groove is formed in the cylindrical portion 69 in advance. By attaching the detection part 61 to the first cover 66C, the guide part can be omitted, and accordingly, the number of parts can be reduced.

In the cover part 72E shown in FIG. 10, the detection part 61 is provided on the first cover 66D by integral molding. By integrally molding, the operation of assembling the detection part 61 to the cover part 72E can be omitted, so that the manufacturing process can be simplified accordingly.

3. Third Embodiment A gripping apparatus according to a third embodiment is different from the first embodiment in that the high-strength portion includes a grip body that is integral with the palm portion, the finger portion, and the connection portion. The same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted. A gripping main body 28B shown in FIG. 11 includes a palm part 30 and a plurality of finger parts 32A provided so as to protrude around the palm part 30. The grip body 28 B has an outer peripheral surface 34 that is curved in a direction protruding outward from the palm portion 30 toward the connection portion 38.

The grip body 28 B includes a high-strength portion 74 that is less likely to deform in the thickness direction than the palm portion 30 between the connection portion 38 and the palm portion 30. The high strength portion 74 is formed integrally with the palm portion 30 and the connection portion 38. The high-strength portion 74 has a proximal end 76 that contacts the lower case 52 and a distal end 75 that is separated from the proximal end 76 toward the finger portion 32 A and connected to the palm portion 30. The high-strength portion 74 is harder to deform than the palm portion 30, but is not a perfect rigid body and is microscopically deformed with the base end 76 as a fulcrum toward the center of the palm portion 30.

The proximal end 76 is provided at a position away from the outer edge of the palm 30 in the thickness direction of the palm 30, that is, at a position away from the palm 30 to the upper opening side of the connecting portion 38. In the case of this embodiment, the base end 76 has a contact surface that contacts the outer peripheral portion of the bottom surface of the case 36. The high-strength portion 74 has an inner peripheral surface 77 in contact with the guide space 40 on the center side of the palm portion 30 continuous with the contact surface. The inner side of the palm portion 30 has a substantially flat inner surface 48 and a curved surface 50 that is provided around the inner surface 48 and protrudes outward. The inner peripheral surface 77 and the inner surface 48 of the palm 30 are connected by a curved surface 50.

The tip 75 of the high strength portion 74 is disposed between the inner peripheral surface 77 and the curved surface 50. The tip 75 serves as a fulcrum when the palm 30 is deformed in the thickness direction.

As shown in FIG. 12, the high-strength portion 74 is formed in accordance with the shape of the connection portion 38 so as to surround the palm portion 30. The contact surface is the upper surface of the high strength portion 74. The outer peripheral portion of the bottom surface of the case 36 contacts the contact surface of the high-strength portion 74.

The gripping device 10 C can obtain the same effect as that of the first embodiment by including the cover portion 72 A.

The high-strength portion 74 is formed integrally with the palm portion 30 and the finger portion 32A, and microscopically deforms in accordance with the deformation of the palm portion 30 in the thickness direction. As a result, the finger part 32A is continuously and gently deformed by the deformation of the palm part 30. Therefore, the gripping device 10C can grip the workpiece W softly. Incidentally, in the gripping main body that does not have the high strength portion 74, the finger portion is deformed so as to buckle.

Since the grip body 28B is formed integrally with the palm portion 30, the finger portion 32A, the high-strength portion 74, and the connection portion 38, the number of parts and the number of manufacturing steps can be reduced. Since the palm portion 30 and the high-strength portion 74 to which more load is applied during decompression are integrally formed, the gripping main body 28B can be prevented from being damaged and the durability can be improved.

The high-strength portion may be a plurality of strips provided at positions corresponding to the finger portions. The high-strength portion is evenly arranged at a position around the palm portion and corresponding to the base end of the finger portion. The high-strength portion has a contact surface on the upper surface and an inner peripheral surface on the inner surface on the palm portion side. The tip of the high strength part is disposed between the inner peripheral surface and the curved surface. By forming the high-strength portion as a belt-like body, the material can be reduced as compared with the case where the high-strength portion is formed in an annular shape, so that the weight can be reduced accordingly.

The high-strength portion may be a plurality of annular convex portions arranged at predetermined intervals in parallel with the thickness direction of the palm portion. The upper surface of the convex portion that is located farthest from the palm is the contact surface. The inner surface on the palm side of the convex portion is the inner peripheral surface.

The high-strength portion may be a plurality of ridges whose longitudinal direction is the thickness direction of the palm portion. The ridges are arranged around the palm portion with a predetermined interval. The upper surface of the ridge is the contact surface, and the inner surface on the palm side is the inner peripheral surface.

The high-strength part may be formed of a material having higher mechanical strength than the palm part. The high-strength part is obtained by integrally forming the finger part and the palm part by insert molding.

4). In the case of the above embodiment, the case has been described in which five finger portions 32A are provided radially so as to surround the palm portion 30, but the present invention is not limited to this. For example, the gripping device 10D illustrated in FIG. 13A includes a gripping main body 28C having two finger portions 32B. The finger parts 32B are arranged on both sides of the palm part and have a flat shape. The gripping device 10D can obtain the same effect as that of the first embodiment by including the cover portion 72A.

A gripping device 10E shown in FIG. 13B includes a gripping main body 28C and a cover portion 72B. The gripping device 10E can obtain the same effects as those of the first embodiment by including the cover portion 72B.

14A includes a gripping main body 28C having three finger portions 32C. The finger parts 32C are radially arranged so as to surround the palm part, and have a tapered shape. The gripping device 10F includes a cover portion 72C in which the first cover 80 and the second cover 81 are separate bodies. The gripping device 10F can obtain the same effects as those of the first embodiment by including the cover portion 72C.

14B includes a grip body 28C and a cover portion 72D. In the cover part 72D, the first cover 80 and the second cover 81 are integrally formed. The gripping device 10G can obtain the same effects as those of the first embodiment by including the cover portion 72D.

In the above embodiment, an example of an orthogonal robot is shown as the industrial robot 12, but the present invention is not limited to this, and can be applied to a SCARA robot, a vertical articulated robot, and the like. In other words, the gripping device can grip the workpiece W and maintain the gripped state even when the industrial robot rotates about the X axis, the Y axis, and the Z axis. Although the case where the gripping device is provided in the air cylinder has been described, it may be provided in the hydraulic cylinder.

The gripping device may be provided with a nail portion on the finger portion. A plate-shaped member made of synthetic resin, a conical member, or a sac-shaped member can be used for the claw portion.

The gripping device may be provided with a camera for photographing the workpiece W, a weigh scale for measuring the weight of the gripped workpiece W, a proximity sensor for measuring the distance between the workpiece W and the gripping main body, and the like. The camera or the like can be fixed to a bracket fixed by being sandwiched between the piston rod 20 and the adapter plate 23. The adapter plate 23 may have a shape having a bracket.

The grip body may be rectangular in plan view. In this case, it is preferable that two pairs of finger portions are provided along the long side of the palm portion, and a plurality of pairs are provided on both sides of the palm portion. As the palm is deformed in the thickness direction, the inner surface of the finger is pulled toward the center of the palm. Then, the finger part is elastically deformed so as to fall down toward the palm part. In this case, the finger part is elastically deformed so as to fall toward the opposing long side. Therefore, the gripping device including the gripping body can easily grip a long member such as a cylindrical shape or a prismatic shape.

The finger part may have an elastic part inside. The elastic part is filled in the finger part and has the shape of the finger part. As long as the shape of the elastic portion is inserted into the finger portion of the gripping body and can maintain a certain shape, there may be a slight gap between the inner surface of the finger portion. The material of the elastic part is preferably resin or rubber. The material of the elastic part is not necessarily uniform, and may be a composite material combining different materials. The elastic portion may include an additive such as a filler. The elastic part is preferably arranged so that there is no gap between the inner surface of the finger part.

The high-strength portion may be formed by combining a plurality of, for example, three ring bodies arranged concentrically.

10A to G Gripping device 12 Industrial robot 28A to C Gripping main body 30 Palm part 32A to C Finger part 36 Case 38 Connection part 40 Guide space 42 High strength part 46 Bending part 47 Guide hole 61 Detection part 64 Detachment part 66A to D 80

First cover

68, 81 Second cover 72A to E Cover part

Claims

The palm,
A plurality of fingers that are provided to project around the palm, and fall toward the palm by deforming the palm in the thickness direction;
A connection part that is formed at a position surrounding the outer edge of the palm part on the opposite side to the side on which the finger part is formed, and connected to the case;
A high-strength portion that is provided between the palm portion and the connection portion, has a predetermined length in the thickness direction of the palm portion from an outer edge of the palm portion, and is less likely to deform than the palm portion;
The case connected to the connecting portion and in contact with the proximal end of the high-strength portion;
A gripping device comprising: a cover portion covering at least a part of the periphery of the portion excluding the palm portion and the finger portion.
The gripping device according to claim 1, wherein the cover portion includes a first cover that covers at least a part of the periphery of the connection portion.
The gripping device according to claim 1, wherein the cover portion includes a second cover that covers at least a part of a detachable portion that is detachably connected to the case.
The gripping device according to any one of claims 1 to 3, wherein a detection unit that detects a surrounding state is provided in the cover unit.
The gripping device according to claim 4, wherein the detection unit detects that the distance to the detection target is within a predetermined range.
The high-strength part is
The palm part, the finger part, and the connection part are separate from each other,
A guide hole for receiving the deformed palm,
The gripping device according to any one of claims 1 to 5, further comprising a curved portion outside the tip of the finger side in the axial direction of the guide hole.
The gripping device according to any one of claims 1 to 5, wherein the palm portion, the finger portion, the connection portion, and the high-strength portion are integrally formed.
The gripping device according to any one of claims 1 to 7, further comprising an outer peripheral surface curved in a direction in which the palm portion and the connection portion protrude outward.
An industrial robot provided with the gripping device according to any one of claims 1 to 8.