Holding device

Abstract

To provide a gripping device that can grip an object more securely, using a fluid-pressure actuator that bends (curls) while shrinking.SOLUTION: Fluid pressure actuators 10 of gripping device 1 have flexibility. One fluid-pressure actuator 10 is arranged in an offset manner so that the one fluid pressure actuator crosses the other fluid pressure actuator 10 at least, at a base end part side of the fluid pressure actuator 10. When the fluid-pressure actuators 10 respectively shrink, a tip part of the one fluid pressure actuator 10 gets close to a tip part of the other fluid-pressure actuator 10 which crosses the one fluid-pressure actuator at the base end part side.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a gripping device that uses a fluid pressure actuator that curves (curls) when contracted. [Background technology]

[0002] Conventionally, a widely used fluid pressure actuator that uses gas or liquid to expand and contract a tube is a structure (the so-called McKibben type) that has a rubber tube that expands and contracts using air pressure and a sleeve that covers the outer surface of the tube.

[0003] Such McKibben type fluid pressure actuators are also known to have a structure that curves (curls) when contracted (see Patent Document 1). Specifically, Patent Document 1 discloses a gripping device that uses a plurality of such fluid pressure actuators to grip an object (which may also be called a workpiece). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-088999 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the above-described gripping device using a fluid pressure actuator has the following problem: Specifically, depending on the size, shape, or properties of the object, the curled fluid pressure actuator may not be able to grip the object properly.

[0006] The following disclosure has been made in light of the above circumstances, and aims to provide a gripping device that can grip an object more reliably while using a fluid pressure actuator that curves (curls) when contracted. [Means for solving the problem]

[0007] One aspect of the present disclosure is a gripping device (e.g., gripping device 1) that uses multiple fluid pressure actuators (fluid pressure actuators 10) that bend when contracted, wherein the fluid pressure actuators are flexible soft actuators, and the fluid pressure actuators are offset at their base ends (base end 200) so as to intersect with at least any other of the fluid pressure actuators, and when each of the fluid pressure actuators contracts, the tip ends (tip end 300) of the fluid pressure actuators approach the tip ends of the other fluid pressure actuators that intersect at the base end. [Effects of the Invention]

[0008] According to the above-described fluid pressure actuator, an object can be gripped more reliably while using a fluid pressure actuator that curves (curls) when contracted. [Brief explanation of the drawings]

[0009] [Figure 1] 1(a) and (b) are perspective views of a gripping device 1 according to this embodiment. [Figure 2] 2(a) to 2(d) are side and bottom views of the gripping device 1. FIG. [Figure 3] FIG. 3 is a side view of the fluid pressure actuator 10. [Figure 4] FIG. 4 is a cross-sectional view of the actuator body 100 taken along the radial direction DR. [Figure 5] FIG. 5 is an explanatory diagram of the behavior of the fluid pressure actuator 10. [Figure 6] 6(a) and (b) are perspective views of a gripping device 1A according to a modified example. [Figure 7] 7(a) to 7(d) are side and bottom views of the gripping device 1A. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments will be described with reference to the drawings. Note that the same or similar reference numerals are used to designate the same functions or configurations, and descriptions thereof will be omitted as appropriate.

[0011] (1) Overall configuration of the gripping device 1(a) and (b) are perspective views of the gripping device 1 according to this embodiment. Specifically, Fig. 1(a) is a perspective view of the gripping device 1 when the fluid pressure actuator 10 is not contracted. Fig. 1(b) is a perspective view of the gripping device 1 when the fluid pressure actuator 10 is contracted.

[0012] 2(a) to 2(d) are side views and bottom views of the gripping device 1. Specifically, Fig. 2(a) and 2(b) respectively show a side view and a bottom view of the gripping device 1 (when the fluid pressure actuator 10 is not contracted). Fig. 2(c) and 2(d) respectively show a side view and a bottom view of the gripping device 1 (when the fluid pressure actuator 10 is contracted).

[0013] The gripping device 1 uses a plurality of fluid pressure actuators 10 (flexible, flexible soft actuators) that curve (curl) when contracted. The gripping device 1 can grip an object (which may also be called a workpiece) using the plurality of fluid pressure actuators 10. The gripping device 1 may be used as a robot hand, etc.

[0014] The gripping device 1 includes a gripping unit 15 and a mounting base 20. The gripping unit 15 is composed of a fluid pressure actuator 10 and a claw portion 50. The gripping device 1 functions as a robot hand and may be movably supported by a support portion (see FIGS. 2(a) and (c)).

[0015] The fluid pressure actuator 10 is attached to a mounting base 20. Specifically, a base end portion 200 (not shown in FIGS. 1 and 2, see FIG. 3) of the fluid pressure actuator 10 is attached to the mounting base 20.

[0016] The fluid pressure actuator 10 is attached to the mounting base 20 so as to face at least one other fluid pressure actuator 10 .

[0017] Specifically, the fluid pressure actuator is provided at a base end 200 side of the fluid pressure actuator, offset so as to intersect with at least any other fluid pressure actuator. More specifically, the fluid pressure actuator is provided at a position offset from the axial direction D of the fluid pressure actuator 10 in a bottom view of the gripping device 1 so as not to interfere with other fluid pressure actuators. AX (See FIG. 3) and are provided offset from each other in a direction perpendicular to the axis of the arrows.

[0018] When each fluid pressure actuator contracts, the tip end 300 (see FIG. 3) of the fluid pressure actuator approaches the tip end 300 of the other fluid pressure actuator that intersects with it on the side of the base end 200. In other words, when the fluid pressure actuator bends, the distance between the tip end 300 of the other intersecting fluid pressure actuator becomes narrower, making it possible to grip an object.

[0019] The multiple fluid pressure actuators may be configured as pairs of fluid pressure actuators 10 provided along direction D11 (first direction) and fluid pressure actuators 10 provided along direction D12 (second direction) intersecting direction D11.

[0020] The gripping device 1 is configured by two pairs of fluid pressure actuators (four fluid pressure actuators in total). It is preferable that the gripping device includes at least two pairs of fluid pressure actuators.

[0021] The claw portion 50 is provided on the tip end portion 300 of the fluid pressure actuator 10. The claw portion 50 is provided across the tip end portions 300 of the plurality of fluid pressure actuators 10, and extends in the axial direction D AX Extends to.

[0022] In this embodiment, the claws 50 have a concave portion so that they can hold an object scooped up by operating (contracting and expanding) the fluid pressure actuator 10. The gripping unit 15 including the claws 50 may be called a scoop, a cup, a bucket, or other similar term.

[0023] (2) Schematic configuration of fluid pressure actuator 3 is a side view of the fluid pressure actuator 10 according to this embodiment. R FIG.

[0024] The fluid pressure actuator 10 has an actuator body 100 , a base end 200 and a tip end 300 .

[0025] The actuator body 100 is made up of a tube 110 and a sleeve 120. A fluid flows into the actuator body 100 via a connection port 211a.

[0026] As a basic characteristic of the actuator body 100, when a fluid flows into the tube 110, the actuator body 100 moves in the axial direction D AX contracts in the radial direction D R In addition, the actuator body 100 expands in the axial direction D of the actuator body 100 due to the outflow of fluid from the tube 110. AX Expands in the radial direction D R Such a change in shape of the actuator body 100 allows the fluid pressure actuator 10 to function as an actuator.

[0027] In this embodiment, a McKibben type fluid pressure actuator having such basic characteristics is used, and the axial direction D AX By providing a restraining member 150 (not shown in FIG. 3, see FIGS. 4 and 5) that restrains (may be called restricting or limiting, the same applies hereinafter) the compression of the axial direction D AX The orthogonal direction, i.e., the radial direction D RIt can be curved (curled).

[0028] The fluid used to drive the fluid pressure actuator 10 can be either a gas such as air, or a liquid such as water or mineral oil, but the fluid pressure actuator 10 in particular has high durability that can withstand hydraulic driving, which applies high pressure to the actuator main body 100.

[0029] The connection port 211a is connected to a drive pressure source for the fluid pressure actuator 10, specifically, a hose (pipe) connected to a gas or liquid compressor. The fluid that flows in via the connection port 211a passes through a passage hole (not shown) and flows into the inside of the actuator main body 100, specifically, into the inside of the tube 110.

[0030] The tube 110 is a cylindrical body that expands and contracts due to the pressure of the fluid. The tube 110 is made of an elastic material such as butyl rubber, as it repeatedly expands and contracts due to the fluid. Furthermore, when the fluid pressure actuator 10 is hydraulically driven, it is preferable that the tube 110 be made of at least one material selected from the group consisting of highly oil-resistant NBR (nitrile rubber), chloroprene rubber, and epichlorohydrin rubber.

[0031] The sleeve 120 is cylindrical and covers the outer surface of the tube 110. The sleeve 120 is an elastic structure made by weaving fiber cords oriented in a predetermined direction, and the oriented cords cross to form a repeated diamond shape. Due to this shape, the sleeve 120 undergoes pantograph deformation and follows the contraction and expansion of the tube 110 while regulating it.

[0032] It is preferable to use fiber cords made of aromatic polyamide (aramid fiber) or polyethylene terephthalate (PET) as the cords constituting the sleeve 120. However, the cords are not limited to these types of fiber cords, and may be cords made of high-strength fibers such as PBO fiber (polyparaphenylene benzobisoxazole).

[0033] In this embodiment, a restraining member 150 is provided between the tube 110 and the sleeve 120.

[0034] Restraint member 150, axial direction D AX It is not compressed in the radial direction D R (which may be referred to as the deflection direction). That is, the restraint member 150 is deformable only along the axial direction D AX Resistance to compression along the axial direction D AX Orthogonal direction (radial direction D R ) can be transformed into

[0035] In other words, the restraining member 150 is AX It is difficult to deform along the radial direction D R The term "deformable" can also be rephrased as "able to be curved or curled."

[0036] Furthermore, the restraining member 150 is arranged in a radial direction D at a position on the outer periphery of the tube 110 where the restraining member 150 is provided. R It also has the function of restricting (limiting) the outward expansion of the tube 110 (and the sleeve 120).

[0037] In this embodiment, the restraint member 150 is disposed inside the sleeve 120, specifically, in a space radially inside the sleeve 120, in the axial direction D AX In this embodiment, the restraining member 150 is formed using a leaf spring.

[0038] The dimensions of the leaf spring are not particularly limited and may be selected depending on the size of the fluid pressure actuator 10 and the required force to be generated. The material of the leaf spring is also not particularly limited, but typically, it is a material that is easy to bend and resistant to compression, such as a metal such as stainless steel. For example, the restraint member 150 may be formed from a thin plate of carbon fiber reinforced plastic (CFRP). CFRP is less susceptible to plastic deformation than metal, and therefore the fluid pressure actuator 10 can easily return to its original straight state after being bent.

[0039] The base end 200 is located on the mounting base 20 side. The above-mentioned connection port 211a is formed in the base end 200. The base end 200 has a connecting port 211a. AX The device may be provided with a mechanism for sealing one end of the device.

[0040] The tip portion 300 is located on the side of the claw portion 50. The tip portion 300 has a groove 301 extending in the axial direction D of the actuator body 100. AX The other end of the nozzle may be provided with a mechanism for sealing the other end.

[0041] The sealing mechanism of the actuator main body 100 provided at the base end 200 and the tip end 300 may be similar to that of the fluid pressure actuator disclosed in, for example, JP 2021-088999 A.

[0042] (3) Behavior of the fluid pressure actuator 10 Figure 5 is an explanatory diagram of the behavior of the fluid pressure actuator 10. The fluid pressure actuator 10 shown in Figure 5 is in a state where the base end 200 side is fixed and the tip end 300 side is free to move. In other words, the base end 200 side is the fixed end and the tip end 300 side is the free end.

[0043] As described above, when a fluid flows into the fluid pressure actuator 10, the fluid flows in the axial direction D AX However, since the restraining member 150 is provided, the AX Contraction along the axis is constrained (regulated).

[0044] In other words, the restraining member 150 formed of a hard member such as a leaf spring plays a role like a backbone, and the restraining member 150 is provided on the opposite side (the lower side in FIG. 5) from the position on the outer periphery of the tube 110 and the sleeve 120 where the restraining member 150 is provided, and the restraining member 150 is provided in the radial direction D R By expanding outward, the axial AX The dimension of the fluid pressure actuator 10 in the direction D1 becomes shorter, and the fluid pressure actuator 10 (specifically, the actuator main body 100) bends along direction D1. Note that direction D1 may also be called the bending direction. Furthermore, to make it easier to recognize that the fluid pressure actuator 10 bends in direction D1, a mark M (see FIG. 3) may be provided to indicate the position where the restraining member 150 is provided.

[0045] The restraining member 150 is provided between the rubber tube 110 and the sleeve 120, and is AX Resistance to compression in the orthogonal direction (radial direction D R ) and is disposed at a portion of the actuator body 100 in the circumferential direction.

[0046] That is, the flow of fluid (pressurization) into the actuator body 100 causes the actuator body 100 (McKibben) to move in the axial direction D AX When the actuator body 100 tries to contract along the perpendicular direction (radial direction D), the portion where the restraint member 150 is arranged cannot contract because the portion where the restraint member 150 is arranged has high compressive rigidity. R ) is generated, causing the binding member 150 to bend with the binding member 150 as its back surface.

[0047] (4) Example of change Next, a modified example of the gripping device 1 will be described. Figures 6(a) and (b) are perspective views of a gripping device 1A according to the modified example. Specifically, Figure 6(a) is a perspective view of the gripping device 1A when the fluid pressure actuator 10 is not contracted. Figure 6(b) is a perspective view of the gripping device 1A when the fluid pressure actuator 10 is contracted.

[0048] 7(a) to 7(d) are side views and bottom views of the gripping device 1A. Specifically, Fig. 7(a) and 7(b) respectively show a side view and a bottom view of the gripping device 1A (when the fluid pressure actuator 10 is not contracted). Fig. 7(c) and 7(d) respectively show a side view and a bottom view of the gripping device 1A (when the fluid pressure actuator 10 is contracted).

[0049] The gripping device 1A includes a gripping unit 15 and a gripping unit 15A. Similar to the gripping device 1, the gripping unit 15 is configured with two fluid pressure actuators 10 and a claw portion 50 (strictly speaking, the gripping unit 15 may differ from the gripping unit 15 of the gripping device 1 in at least one of the size and the connection position of the fluid pressure actuators 10).

[0050] On the other hand, the gripping unit 15A is composed of three fluid pressure actuators 10 and a claw portion 50.

[0051] (5) Actions and Effects According to the above-described embodiment, the following advantageous effects can be obtained. Specifically, according to the gripping device 1 (and gripping device 1A) including the above-described modified example, the fluid pressure actuator 10 is provided offset on the base end 200 side so as to intersect with at least one other fluid pressure actuator 10. Furthermore, when each fluid pressure actuator 10 contracts, the tip end 300 of the fluid pressure actuator 10 approaches the tip end 300 of the other fluid pressure actuator that intersects with it on the base end 200 side. Furthermore, a claw portion 50 is provided on the tip end 300 of the fluid pressure actuator 10.

[0052] Therefore, the gripping unit 15 can grip objects over a wider range, allowing it to grip objects more reliably regardless of the size, shape, or properties of the object. In particular, it can grip objects that change shape when gripped and lifted (for example, a bag of rice) more reliably.

[0053] Furthermore, the gripping device 1 (and gripping device 1A) may include at least two pairs of fluid pressure actuators 10, each pair consisting of a fluid pressure actuator 10 provided along direction D11 and a fluid pressure actuator 10 provided along direction D12 intersecting direction D11. This allows the object to be gripped reliably over a wider range.

[0054] Furthermore, in the gripping device 1A, one more fluid pressure actuator 10 (gripping unit 15A) is added to the two pairs of fluid pressure actuators 10. Therefore, even when an object is gripped via the claw portions 50, twisting in the gripping direction is less likely to occur, and the object can be gripped more reliably.

[0055] (6) Other embodiments Although the embodiments have been described above, it will be obvious to those skilled in the art that the present invention is not limited to the description of the embodiments and that various modifications and improvements are possible.

[0056] For example, the gripping device 1 and the gripping device 1A are provided with at least two pairs of fluid pressure actuators 10, but the gripping device may be configured with one pair of fluid pressure actuators 10. Also, the claw portion 50 provided across the tip portions 300 of the multiple fluid pressure actuators 10 is not necessarily required.

[0057] In the above-described embodiment, the flexibility of the fluid pressure actuator is ensured by using the restraint member 150, but the flexibility of the fluid pressure actuator may be ensured by a different structure. For example, by providing a flexible frame material with a portion shaped like a bellows around the fluid pressure actuator, when the fluid pressure actuator contracts, the fluid pressure actuator may bend with the bellows portion facing inward.

[0058] Although the present disclosure has been described in detail above, it is clear to those skilled in the art that the present disclosure is not limited to the embodiments described herein. The present disclosure can be implemented in modified and altered forms without departing from the spirit and scope of the present disclosure as defined by the claims. Therefore, the description of the present disclosure is intended to be illustrative and does not have any limiting meaning on the present disclosure. [Explanation of symbols]

[0059] 1, 1A gripping device 10. Fluid pressure actuator 15, 15A gripping unit 20 Mounting base 50 Claw 100 Actuator body 110 tubes 120 sleeves 150 Restraining member 200 Proximal end 211a connection port 300 Tip

Claims

1. A grasping device using a plurality of fluid pressure actuators that bend when contracted, the fluid pressure actuator is a soft actuator having flexibility, the fluid pressure actuator is provided offset from at least any other fluid pressure actuator on a base end side of the fluid pressure actuator so as to intersect with the other fluid pressure actuator, A gripping device in which, when each of the fluid pressure actuators contracts, the tip end portion of the fluid pressure actuator approaches the tip end portion of the other fluid pressure actuator that intersects with it on the base end side.

2. The fluid pressure actuator includes: a cylindrical tube that expands and contracts due to fluid pressure; a sleeve that is an elastic structure in which fiber cords oriented in a predetermined direction are woven and covers the outer surface of the tube; The gripping device of claim 1 , comprising:

3. 3. The gripping device according to claim 1, further comprising a claw portion provided across the tip ends of the plurality of fluid pressure actuators and extending in the axial direction of the fluid pressure actuators.

4. the plurality of fluid pressure actuators form pairs of the fluid pressure actuator provided along a first direction and the fluid pressure actuator provided along a second direction intersecting the first direction, The gripping device according to claim 1 , wherein the gripping device includes at least two pairs of the hydraulic actuators.

5. The gripping device according to claim 2 , wherein the fluid pressure actuator includes a restraining member provided inside the sleeve and extending from one end side to the other end side in the axial direction of the tube.

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