Fluid pressure actuator and fitting

Abstract

A fluid pressure actuator is provided with an elastic tube having a tube main body and a reinforcing member, the elastic tube expanding in the radial direction and contracting in the axial direction by fluid pressure supplied to the tube main body. The fluid pressure actuator is provided with a first bracket fitted to a first end portion of the elastic tube and a second bracket fitted to a second end portion of the elastic tube. The fluid pressure actuator is provided with a plate member provided between the first holder and the second holder, and the plate member is disposed on the outside of the elastic tube and has a wave-shaped portion. The fluid pressure actuator is provided with a connecting member that holds the plate member and the elastic tube.

Description

Technical Field

[0001] This disclosure relates to fluid pressure actuators and accessories. Background Technology

[0002] Previously, an elastic tube that contracts axially under the pressure of a fluid such as compressed air was known. Furthermore, an actuator described below is known as a fluid pressure actuator that bends the elastic tube.

[0003] Patent Document 1 discloses a fluid pressure actuator having a flat plate-shaped restraining member between a tube and a sleeve covering the tube. If compressed air is supplied to the fluid pressure actuator to cause the tube to contract axially, the fluid pressure actuator causes the restraining member to bend outward.

[0004] Furthermore, Non-Patent Document 1 discloses a fluid pressure actuator having a flexible sleeve around a pipe. Multiple slits forming a bellows portion are formed on the side of the sleeve covering the pipe. If compressed air is supplied to this fluid pressure actuator to cause the pipe to contract axially, the fluid pressure actuator causes the bellows portion of the sleeve to bend inwards.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2021-088999

[0008] Non-patent literature

[0009] Non-patent literature 1: F.Zhao, S.Dohta and T.Akagi, Development and Analysis ofBending ActuatorUsing McKibben Artificial Muscle, Journal of System Design andDynamics, Vol.6 No.2 (2012), p.158-169 Summary of the Invention

[0010] The technical problem that the invention aims to solve

[0011] The fluid pressure actuator disclosed in Patent Document 1 has a structure in which a restraining component is assembled between the tube and the sleeve. Assembling a restraining component between the tube and the sleeve in this way will complicate the manufacturing process of the fluid pressure actuator and increase its cost.

[0012] The fluid pressure actuator disclosed in Non-Patent Document 1 has a bellows-shaped flexible sleeve, which not only makes the bending shape of the fluid pressure actuator unstable, but also makes it difficult to maintain the posture of the fluid pressure actuator.

[0013] The purpose of this disclosure is to provide a low-cost fluid pressure actuator and accessories capable of maintaining posture.

[0014] Technical solutions to solve technical problems

[0015] According to this disclosure, a fluid pressure actuator includes an elastic tube having a tube body and a reinforcing member. The elastic tube expands radially and contracts axially by fluid pressure supplied to the tube body. The fluid pressure actuator includes a first support mounted on a first end of the elastic tube and a second support mounted on a second end of the elastic tube. The fluid pressure actuator includes a plate member disposed between the first and second supports, positioned outside the elastic tube, and having a corrugated portion. The fluid pressure actuator includes a connecting member for maintaining the plate member and the elastic tube.

[0016] According to this disclosure, the fitting is used on an elastic tube that expands radially and contracts axially by fluid pressure supplied to the tube body. The fitting includes a first bracket for mounting to the elastic tube and a second bracket for mounting to the elastic tube. The fitting includes a plate member having a corrugated portion disposed between the first and second brackets. The fitting includes a connecting member for retaining the plate member and the elastic tube.

[0017] Invention Effects

[0018] According to this disclosure, since there is a plate component between the first support and the second support, it is possible to suppress costs and maintain posture. Attached Figure Description

[0019] Figure 1 This is a perspective view showing a fluid pressure actuator according to one embodiment.

[0020] Figure 2 This is a cross-sectional view showing a fluid pressure actuator.

[0021] Figure 3 It is a three-dimensional view showing a part of the elastic tube.

[0022] Figure 4A This is a diagram showing the fluid pressure actuator in its initial state.

[0023] Figure 4B This is a diagram showing a fluid pressure actuator in a bent state.

[0024] Figure 5 This is a perspective view of a gripping device that uses a fluid pressure actuator.

[0025] Figure 6A This is a diagram showing the panel components.

[0026] Figure 6B This is a diagram showing a variation of a plate component.

[0027] Figure 6C This is a diagram showing a variation of a plate component.

[0028] Figure 6D This is a diagram showing a variation of a plate component.

[0029] Figure 6E This is a diagram showing a variation of a plate component.

[0030] Figure 7 This is a diagram showing a variation of a fluid pressure actuator and its components. Detailed Implementation

[0031] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Furthermore, in the following description, the same or substantially the same structures and elements will be labeled with the same reference numerals, and repeated descriptions will be omitted.

[0032] Structure of fluid pressure actuators and accessories

[0033] like Figure 1 As shown, the fluid pressure actuator 1 has an elastic tube 10 and a fitting 2 assembled to the elastic tube 10. The fitting 2 includes a connector bracket (first bracket) 20A for assembly to the elastic tube 10 and a connector bracket (second bracket) 20B for assembly to the elastic tube 10. In addition, the fitting 2 includes a plate member 30 disposed between the connector bracket 20A and the connector bracket 20B and an O-ring (connecting member, annular member) 40 for retaining the plate member 30 and the elastic tube 10.

[0034] like Figure 3 As shown, the elastic tube 10 consists of a tube body 11 and a braided sleeve 12, which serves as a reinforcing component. The tube body 11 is made of a freely elastically deformable material such as synthetic resin or synthetic rubber. The braided sleeve 12 is a mesh structure formed by braiding threads made of polyester resin, polyamide resin, or the like into a tubular shape. The braided sleeve 12 covers the outside of the tube body 11. The elastic tube 10 can freely elastically deform in both the radial and longitudinal directions.

[0035] Specifically, if compressed air, liquid, or other fluid is supplied to the internal space 11a of the tube body 11, the elastic tube 10 contracts by expanding radially outward under the supplied fluid pressure and shortening its entire length. This elastic tube 10 is also referred to as a McKibben-type artificial muscle. Additionally, as... Figure 1 As shown, the flexible tube 10 has adapters 13 at both ends. Such a flexible tube can, for example, use the actuator element shown in Japanese Patent Application Publication No. 2021-099141.

[0036] like Figure 1 and Figure 2 As shown, connector bracket 20A is fitted to the first end 10A, which is one side of the elastic tube 10. Connector bracket 20B is fitted to the second end 10B, which is the other side of the elastic tube 10. Furthermore, in the following description, one side will sometimes be referred to as the front end side, and the other side as the base end side.

[0037] like Figure 2 As shown, the connector bracket 20A on the front end side has a block 24A with a mounting hole 21 and a through hole 22. A connecting portion 31A provided at the end of the plate member 30 is inserted into the mounting hole 21 of the block 24A. The connecting portion 31A inserted into the mounting hole 21 is fixed to the connector bracket 20A by a pin 28. In addition, a connector 23A is held in the through hole 22 of the block 24A. A plunger 15 is inserted into the connector 23A from one side, and an elastic tube 10 is inserted into the connector 23A from the other side.

[0038] The connector 23A has a sealing member 25, a locking pawl 26, and a release ring 27. The connector 23A is sealed to the plunger 15 by the sealing member 25, and the plunger 15 is fixed to the connector 23A by the locking pawl 26. Similarly, the connector 23A is sealed to the elastic tube 10 by the sealing member 25, and the elastic tube 10 is fixed to the connector 23A by the locking pawl 26. Furthermore, by pressing in the release ring 27, the engagement of the locking pawl 26 with the elastic tube 10 and the plunger 15 can be released, thereby allowing the elastic tube 10 and the plunger 15 to be removed from the connector 23A.

[0039] Similarly, the connector bracket 20B on the base end side has a block 24B with a mounting hole 21 and a through hole 22. A connecting portion 31B provided at the end of the plate member 30 is inserted into the mounting hole 21 of the block 24B. The connecting portion 31B inserted into the mounting hole 21 is fixed to the connector bracket 20B by a pin 28. In addition, a connector 23B is held in the through hole 22 of the block 24B. An elastic tube 10 is inserted into the connector 23B from one side, and a supply pipe 14 is inserted into the connector 23B from the other side.

[0040] The connector 23B has a sealing member 25, a locking claw 26, and a release ring 27. The connector 23B is sealed to the supply / discharge pipe 14 by the sealing member 25, and the supply / discharge pipe 14 is fixed to the connector 23B by the locking claw 26. Similarly, the connector 23B is sealed to the elastic tube 10 by the sealing member 25, and the elastic tube 10 is fixed to the connector 23B by the locking claw 26. In addition, by pressing in the release ring 27, the engagement between the locking claw 26 and the elastic tube 10 and the supply / discharge pipe 14 can be released, thereby allowing the elastic tube 10 and the supply / discharge pipe 14 to be removed from the connector 23B.

[0041] The supply / discharge pipe 14 and the flexible pipe 10 are interconnected via connector 23B. Additionally, a pressure source is connected to the supply / discharge pipe 14 via a valve unit (not shown). Compressed air can be supplied from the supply / discharge pipe 14 to the flexible pipe 10 by controlling the valve unit. Conversely, compressed air can be discharged from the flexible pipe 10 to the supply / discharge pipe 14 by controlling the valve unit.

[0042] The plate component 30 is disposed between the joint bracket 20A and the joint bracket 20B. The plate component 30 is positioned on the outside of the elastic tube 10. The plate component 30 is constructed, for example, using a thin plate made of plastic or metal. The plate component 30 possesses self-supporting, flexible, and restorative properties. That is, if no external force is applied to the plate component 30, it self-supports and maintains its shape. Furthermore, if an external force is applied to the plate component 30, it flexes; if the external force is removed, it returns to its original shape.

[0043] The plate member 30 has a connecting portion 31A at one end, a connecting portion 31B at the other end, and a wave portion 32 between the connecting portions 31A and 31B. The connecting portion 31A is held in the mounting hole 21 of the connector bracket 20A, and the connecting portion 31B is held in the mounting hole 21 of the connector bracket 20B. The wave portion 32 has a repeating shape of peaks 33 and valleys 34. In the illustrated example, the periods and amplitudes of the multiple waves constituting the wave portion 32 are the same. Furthermore, in the illustrated example, the wave portion 32 has four peaks 33 and five valleys 34, but it is not limited to this; the number of peaks 33 and valleys 34 constituting the wave portion 32 can be varied. Further variations of the wave portion 32 will be referred to... Figure 6A , Figure 6B , Figure 6C , Figure 6D as well as Figure 6E As will be described below.

[0044] The O-ring 40 is installed around the plate member 30 and the elastic tube 10, and holds the plate member 30 and the elastic tube 10 in place. Furthermore, the O-ring 40, as a ring-shaped component, is wound around the valley 34 of the corrugated portion 32 constituting the plate member 30. Because the O-ring 40 is wound around the valley 34, even if the elastic tube 10 deforms due to air pressure, the O-ring 40 will not deviate from the valley 34 and approach the end of the plate member 30. For example, the O-ring 40 is made of an elastomer such as rubber. Friction is generated between the O-ring 40 and the valley 34, and between the O-ring 40 and the elastic tube 10, thus suppressing the sliding of the O-ring 40 relative to the plate member 30 and the elastic tube 10.

[0045] Action of fluid pressure actuator

[0046] Figure 4A and Figure 4B This is a diagram showing the fluid pressure actuator 1. Figure 4A The diagram shows the fluid pressure actuator 1 in its initial state, without pressure application. Figure 4B The diagram shows the pressure application state, i.e., the bending state, of the fluid pressure actuator 1. For example... Figure 4A As shown, if compressed air is supplied from the supply pipe 14 to the internal space 11a of the pipe body 11 with the connector bracket 20B on the base side fixed to a pedestal (not shown) or the like, then as... Figure 4B As shown, the supply and discharge pipes 14 and plate components 30 of the fluid pressure actuator 1 are bent.

[0047] like Figure 4B As shown, in the bent state of the fluid pressure actuator 1, the elastic tube 10 expands radially and contracts axially. At this time, the elastic tube 10 contracts axially, i.e., along its length, while the contraction along the length of the plate member 30 is restricted, thus bending both the elastic tube 10 and the plate member 30 of the fluid pressure actuator 1. In other words, the fluid pressure actuator 1 is bent with the elastic tube 10 positioned inside and the plate member 30 positioned outside. Furthermore, if compressed air is discharged from the internal space 11a of the elastic tube 10, then... Figure 4A As shown, the fluid pressure actuator 1 returns to its initial state through the restoring force of the plate component 30.

[0048] As described above, the plate component 30 possesses self-support, flexibility, and resilience. Therefore, as Figure 4A As shown, even when compressed air is discharged from the elastic tube 10, the plate member 30 maintains its initial shape, thus the fluid pressure actuator 1 remains in its initial state of linear extension. In this way, the fluid pressure actuator 1 is able to maintain its initial state.

[0049] like Figure 4BAs shown, if compressed air is supplied to the elastic tube 10, the contraction force in the longitudinal direction of the elastic tube 10 increases, and the plate member 30 flexes accordingly with respect to the contraction force of the elastic tube 10, thus causing the fluid pressure actuator 1 to change from its initial state to a bent state. Furthermore, if in Figure 4B In the bent state shown, compressed air is discharged from the elastic tube 10, and the contraction force in the length direction of the elastic tube 10 decreases. Then, the restoring force of the plate component 30 causes the plate component 30 to return to its initial shape. Therefore, the fluid pressure actuator 1 changes from the bent state to the initial state.

[0050] Furthermore, the bending state of the fluid pressure actuator 1, that is, the position of the connector bracket 20A that moves along with the bending of the fluid pressure actuator 1, is determined by the balance between the contraction force of the elastic tube 10 and the restoring force of the plate member 30. In other words, by keeping the pressure of the compressed air supplied to the elastic tube 10 constant, the contraction force of the elastic tube 10 can be kept constant, thus maintaining the bending state of the fluid pressure actuator 1. In this way, the fluid pressure actuator 1 can maintain its bent posture.

[0051] As described above, the fluid pressure actuator 1 and accessory 2 include connector supports 20A and 20B mounted on the elastic tube 10 and a plate component 30 disposed between the connector supports 20A and 20B. Furthermore, the mounting structure of the plate component 30 is not an assembly onto the elastic tube 10, but rather a structure disposed on the outside of the elastic tube 10. Therefore, the fluid pressure actuator 1 and accessory 2 can be constructed simply, reducing their cost.

[0052] Grip device

[0053] Fluid pressure actuator 1, for example, is used for Figure 5 The gripping device 50 is shown. The gripping device 50 includes a base 51 and four fluid pressure actuators 1. In the following description, from the viewpoint of distinguishing the four fluid pressure actuators 1, each fluid pressure actuator is referred to by reference numerals 1A, 1B, 1C, and 1D.

[0054] Fluid pressure actuators 1A and 1B are arranged opposite each other. Fluid pressure actuators 1C and 1D are arranged opposite each other. A pair of fluid pressure actuators 1A and 1B and a pair of fluid pressure actuators 1C and 1D are arranged side by side.

[0055] The base 51 of the gripping device 50 is used for mounting on robots such as handling robots (not shown). A connector bracket 20B for each fluid pressure actuator 1A, 1B, 1C, and 1D is integrally provided on the base 51. Additionally, a soft pad 52 is provided on the connector bracket 20A for each fluid pressure actuator 1A, 1B, 1C, and 1D.

[0056] In the gripping device 50, compressed air is supplied to the elastic tubes 10 of the four fluid pressure actuators 1A, 1B, 1C, and 1D, causing each fluid pressure actuator 1A, 1B, 1C, and 1D to bend. As a result, the pads 52 of each fluid pressure actuator 1A, 1B, 1C, and 1D can be brought closer together, allowing a workpiece (not shown) to be gently gripped through the pads 52.

[0057] Deformation examples of plate components

[0058] Figure 6A , Figure 6B , Figure 6C , Figure 6D as well as Figure 6E This is a diagram showing plate components 30, 30B, 30C, 30D, and 30E. In Figure 6A It shows Figure 1 and Figure 2 The plate component 30 is shown in the image. Figure 6B , Figure 6C , Figure 6D as well as Figure 6E The plate components 30B, 30C, 30D, and 30E involved in other variations are shown in the figure.

[0059] like Figure 6A As shown, the plate member 30 has connecting portions 31A and 31B at both ends, and a wave portion 32 between the connecting portions 31A and 31B. In the cross-section along the length direction of the wave portion 32 of the plate member 30, at least one of the outline of the cross-sectional shape and the center line contains a sine curve. That is, the shape of the wave portion 32 of the plate member 30 is a sine curve.

[0060] Figure 6B , Figure 6C as well as Figure 6D The plate components 30B, 30C, 30D, and 30E shown have wave portions 32B, 32C, 32D, and 32E with different shapes compared to the wave portion 32 of the plate component 30.

[0061] like Figure 6B As shown, plate member 30B has connecting portions 31A and 31B at both ends, and a wave portion 32B between connecting portions 31A and 31B. In a cross-section along the length direction of the wave portion 32B of plate member 30B, at least one of the profile of the cross-sectional shape and the center line includes an attenuation curve. That is, the shape of the wave portion 32B of plate member 30B is an attenuation curve. Furthermore, the attenuation curve is a curve whose amplitude decreases as it moves along the length direction.

[0062] like Figure 6CAs shown, the plate member 30C has connecting portions 31A and 31B at both ends, and a wave portion 32C between the connecting portions 31A and 31B. In a cross-section along the length of the wave portion 32C of the plate member 30C, at least one of the profile of the cross-sectional shape and the center line contains a curve composed of multiple waves. This curve includes a wave WC1 with a period T1 and a wave WC2 with a period T2 shorter than the period T1. That is, the shape of the wave portion 32C of the plate member 30C is a curve containing multiple waves with different periods. Furthermore, Figure 6C The curves shown are WC1 and WC2, which contain two waves with different periods, but this is not the only example. Curves can also contain three or more waves with different periods.

[0063] like Figure 6D As shown, the plate member 30D has connecting portions 31A and 31B at both ends, and a wave portion 32D between the connecting portions 31A and 31B. In a cross-section along the length of the wave portion 32D of the plate member 30D, at least one of the profile of the cross-sectional shape and the center line contains a curve composed of multiple waves. This curve includes a wave WD1 with amplitude A1 and a wave WD2 with amplitude A2 larger than amplitude A1. That is, the shape of the wave portion 32D of the plate member 30D is a curve containing multiple waves with different amplitudes. Furthermore, Figure 6D The curve shown is a curve containing two waves WD1 and WD2 with different amplitudes, but it is not limited to this and can also be a curve containing three or more waves with different amplitudes.

[0064] like Figure 6E As shown, the plate member 30E has connecting portions 31A and 31B at both ends, and a wave-shaped portion 32E and a flat portion 35E are located between the connecting portions 31A and 31B. By using the plate member 30E composed of the wave-shaped portion 32E and the flat portion 35E, the degree of bending in the length direction of the fluid pressure actuator 1 can be varied. That is, the degree of bending of the wave-shaped portion 32E can be greater than that of the flat portion 35E. In other words, the radius of curvature of the wave-shaped portion 32E can be smaller than the radius of curvature of the flat portion 35E.

[0065] The shapes of waveform sections 32, 32B, 32C, 32D, and 32E are not limited to... Figure 6A , Figure 6B , Figure 6C as well as Figure 6D The shapes shown are also possible. The waveforms of each waveform section 32, 32B, 32C, 32D, and 32E can also be combined. Furthermore, in... Figure 6EIn the example shown, one waveform section 32E and one flat section 35E are combined, but this is not a limitation; two or more waveform sections 32E and two or more flat sections 35E can also be combined. That is, as long as at least a portion of the plate components 30, 30B, 30C, 30D, and 30E constituting part of the fluid pressure actuator 1 and accessory 2 has waveform sections 32, 32B, 32C, 32D, and 32E in the length direction, the fluid pressure actuator 1 can be controlled to a desired bending state by any combination of the waveforms of the waveform sections 32, 32B, 32C, 32D, and 32E shown in the figure.

[0066] Furthermore, the shapes of the mountain portions 33 and valley portions 34 constituting the wave portions 32, 32B, 32C, 32D, and 32E are preferably formed as follows: Figure 6A , Figure 6B , Figure 6C , Figure 6D as well as Figure 6E The curve shape shown. In other words, from the viewpoint of mitigating stress concentration relative to the mountain 33 and valley 34 during gentle bending, it is preferable that the shape of the mountain 33 and valley 34 be curved.

[0067] Variations of fluid pressure actuators and accessories

[0068] This disclosure is not limited to the described embodiments, and various modifications may be made without departing from its spirit.

[0069] exist Figure 2 In the example shown, connectors 23A and 23B are installed on connector brackets 20A and 20B, but this is not a limitation; connectors 23A and 23B could also be located away from connector brackets 20A and 20B. Figure 7 This is a diagram showing a variation of a fluid pressure actuator and its components.

[0070] like Figure 7 As shown, the fluid pressure actuator 60 has a flexible tube 10 and a fitting 61 mounted on the flexible tube 10. The fitting 61 includes a bracket (first bracket) 62 for mounting on the flexible tube 10 and a bracket (second bracket) 63 for mounting on the flexible tube 10. Through holes 62a and 63a for the flexible tube 10 to pass through are provided in the brackets 62 and 63. In addition, the fitting 61 includes a plate member 30 disposed between the brackets 62 and 63 and an O-ring 40 for holding the plate member 30 and the flexible tube 10.

[0071] The bracket 62 of accessory 61 is mounted on the first end 10A of the elastic tube 10 and is opposite to the connector 64 mounted on the first end 10A. Additionally, the bracket 63 of accessory 61 is mounted on the second end 10B of the elastic tube 10 and is opposite to the connector 65 mounted on the second end 10B. Here, the inner diameter of the through holes 62a and 63a formed in the brackets 62 and 63 is smaller than the outer diameter of the connectors 64 and 65.

[0072] In the fluid pressure actuator 60 equipped with this accessory 61, if compressed air is supplied to the elastic tube 10, causing the elastic tube 10 to contract axially, the connector 64 moves closer to the support 62, and the connector 65 moves closer to the support 63. Furthermore, if the connector 64 contacts the support 62 and the connector 65 contacts the support 63, the fluid pressure actuator 60 then begins to bend. At this time, since the accessory 61 is not fixed to the elastic tube 10, the bending direction of the fluid pressure actuator 60 can be freely changed by rotating the accessory 61 around the circumference of the elastic tube 10.

[0073] In the above description, a rubber O-ring 40 is used as the connecting member between the loosely bound plate component 30 and the elastic tube 10. However, it is not limited to this; the connecting member can also be a ring-shaped component made of metal or resin. Furthermore, the shape of the connecting member is not limited to a circular, elliptical, or other ring-shaped component. In other words, it can be of any shape as long as it can connect the plate component 30 and the elastic tube 10. Additionally, in the above description, compressed air is used as the fluid supplied to the elastic tube 10. However, it is not limited to this; the fluid can also be a gas other than compressed air, or it can be a liquid.

[0074] Explanation of reference numerals in the attached figures

[0075] 1, 1A, 1B, 1C, 1D: Fluid pressure actuator; 2: Accessory; 10: Elastic tube; 10A: First end; 10B: Second end; 11: Tube body; 12: Braided sleeve (reinforcing component); 20A: Connector bracket (first bracket); 20B: Connector bracket (second bracket); 30, 30B, 30C, 30D, 30E: Plate component; 32, 32B, 32C, 32D, 32E: Wave section; 34: Valley section; 40: O-ring (connecting component, ring component); 60: Fluid pressure actuator; 61: Accessory; 62: Bracket (first bracket); 63: Bracket (second bracket); A1, A2: Amplitude; T1, T2: Period; WC1, WC2, WD1, WD2: Wave.

Claims

1. A fluid pressure actuator, comprising: An elastic tube having a tube body and reinforcing components, the elastic tube expanding radially and contracting axially by fluid pressure supplied to the tube body; The first support is assembled at the first end of the elastic tube; The second support is assembled at the second end of the elastic tube; A plate component, disposed between the first support and the second support, the plate component being positioned outside the elastic tube and having a corrugated portion; and A connecting component that holds the plate component and the elastic tube together.

2. The fluid pressure actuator according to claim 1, wherein, The waveform portion has a sinusoidal shape.

3. The fluid pressure actuator according to claim 1, wherein, The shape of the waveform is an attenuation curve.

4. The fluid pressure actuator according to claim 1, wherein, The waveform portion has a curved shape that contains multiple waves with different periods.

5. The fluid pressure actuator according to claim 1, wherein, The waveform portion is a curve containing multiple waves with different amplitudes.

6. The fluid pressure actuator according to claim 1, wherein, The reinforcing component is located on the outside of the tube body and is a mesh structure made of woven tubular threads.

7. The fluid pressure actuator according to claim 1, wherein, The connecting component is an annular component assembled between the valley of the wave section and the elastic tube.

8. A fitting for use in an elastic tube, the elastic tube expanding radially and contracting axially by fluid pressure supplied to a tube body, the fitting comprising: A first bracket is used for assembly onto the elastic tube; The second bracket is used for assembly onto the elastic tube; A plate component is disposed between the first bracket and the second bracket and has a corrugated portion; as well as A connecting component for holding the plate component to the elastic tube.

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