Fluid pressure actuator

Abstract

To provide a fluid pressure actuator capable of further certainly preventing a sleeve from falling out from a sealing member, while using a locking member for locking the sleeve.SOLUTION: A fluid pressure actuator is equipped with an actuator body portion 100, and a sealing mechanism 200. The sealing mechanism 200 has a sealing member 210 into which the sealing mechanism 200 is inserted, a caulking ring 230 that is provided on an outer peripheral surface of the sealing mechanism 200 into which the sealing member 210 is inserted, and restrains the sealing mechanism 200, and a locking wire 220 that locks a sleeve to the sealing member 210. The sealing member 210 has a head portion 211 provided on an outer side than a body portion 212, and an intermediate portion 213 provided between the body portion 212 and a head portion 211. The intermediate portion 213 has a diameter expanding part 214 that has a smaller size in a diametrical direction of the sealing mechanism 200 than the head portion 211 and bulges outward in a diametrical direction of the actuator body portion 100 than the body portion 212. The locking wire 220 is compressively deformed to fill a space formed between the caulking ring 230 and the intermediate portion 213.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a fluid pressure actuator that expands and contracts a tube using a gas or a liquid, and more specifically, to a so-called McKibben type fluid pressure actuator.

Background Art

[0002] Conventionally, as a fluid pressure actuator that expands and contracts a tube as described above, a structure (so-called McKibben type) having a rubber tube (tubular body) that expands and contracts by air pressure and a sleeve (mesh reinforcing structure) that covers the outer peripheral surface of the tube has been widely used.

[0003] Both ends of the actuator main body portion composed of the tube and the sleeve are sealed using a sealing member formed of metal.

[0004] The sleeve is a cylindrical structure body in which high-tensile fibers such as polyamide fibers or metal cords are woven, and restricts the expansion movement of the tube within a predetermined range.

[0005] In order to prevent the sleeve from coming off from the sealing member due to the load during the operation of such a McKibben type fluid pressure actuator, a structure is known in which a locking member (locking ring) is used to lock the sleeve to a flange portion formed on the sealing member (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] According to the structure using the above-described locking member, the failure of the fluid pressure actuator can be prevented, and the durability of the fluid pressure actuator is improved.

[0008] However, there are cases where a high pressure is applied to the fluid pressure actuator (such as in the case of hydraulic drive), and even higher durability has been required.

[0009] Therefore, the following disclosure has been made in view of such a situation, and an object is to provide a fluid pressure actuator that can more reliably prevent the sleeve from coming off from the sealing member while using a locking member for locking the sleeve.

Means for Solving the Problems

[0010] One aspect of the present disclosure is a fluid pressure actuator including an actuator body portion composed of a cylindrical tube that expands and contracts by the pressure of a fluid and a structure in which cords oriented in a predetermined direction are woven, and a sleeve that covers the outer peripheral surface of the tube, and a sealing mechanism that seals an end portion of the actuator body portion in the axial direction of the actuator body portion. The sealing mechanism includes a sealing member through which the actuator body portion is inserted, a restraining member provided on the outer peripheral surface of the actuator body portion inserted through the sealing member to restrain the actuator body portion, and a locking member that locks the sleeve to the sealing member.

[0011] The sealing member has a body portion through which the tube is inserted, a head portion provided outside the body portion in the axial direction, and an intermediate portion provided between the body portion and the head portion.

[0012] The intermediate portion is smaller in size in the radial direction of the actuator body portion than the head portion, and has a diameter-expanded portion that bulges outward in the radial direction of the actuator body portion from the body portion. The locking member is compressed and deformed to fill a space formed between the restraining member and the intermediate portion.

Effects of the Invention

[0013] According to the above-described fluid pressure actuator, it is possible to more reliably prevent the sleeve from coming off from the sealing member while using a locking member for locking the sleeve.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Modes for Carrying Out the Invention

[0015] Hereinafter, embodiments will be described with reference to the drawings. In addition, the same or similar reference numerals are given to the same functions and configurations, and the description thereof will be omitted as appropriate.

[0016] (1) Overall Schematic Configuration of the Fluid Pressure Actuator FIG. 1 is a side view of the fluid pressure actuator 10 according to the present embodiment. As shown in FIG. 1, the fluid pressure actuator 10 includes an actuator main body portion 100, a sealing mechanism 200, and a sealing mechanism 300.

[0017] The sealing mechanisms 200 and 300 seal both ends of the actuator main body portion 100 in the axial direction D AX Specifically, the sealing mechanism 200 includes a sealing member 210 and a caulking ring 230. The sealing member 210 is in the axial direction D of the actuator main body portion 100 AXSeal the end portion. Also, the caulking ring 230 caulks (which may be expressed as "crimps") the actuator main body portion 100 together with the sealing member 210. On the outer peripheral surface of the caulking ring 230, an indentation 231, which is a mark where the caulking ring 230 has been caulked by a jig, is formed.

[0018] The difference between the sealing mechanism 200 and the sealing mechanism 300 is whether or not a fluid connection port 211a is provided.

[0019] The actuator main body portion 100 is composed of a tube 110 and a sleeve 120. Fluid flows into the actuator main body portion 100 through the connection port 211a.

[0020] The actuator main body portion 100 contracts in the axial direction D of the actuator main body portion 100 due to the inflow of fluid into the tube 110 AX and expands in the radial direction D R Also, the actuator main body portion 100 expands in the axial direction D of the actuator main body portion 100 due to the outflow of fluid from the tube 110 AX and contracts in the radial direction D R Due to such a change in the shape of the actuator main body portion 100, the fluid pressure actuator 10 exhibits its function as an actuator.

[0021] The fluid used to drive the fluid pressure actuator 10 may be either a gas such as air or a liquid such as water or mineral oil. In particular, the fluid pressure actuator 10 has high durability that can withstand even high-pressure hydraulic driving with high pressure applied to the actuator main body portion 100.

[0022] Also, such a fluid pressure actuator 10 is of the so-called McKibben type and can be applied not only for artificial muscles but also preferably for the limbs (such as upper limbs and lower limbs) of robots that require higher capabilities (contracting force).

[0023] Furthermore, the fluid pressure actuator 10 can also be used as a body-worn power assist device, a walking assist device, a training device such as muscle strength, etc.

[0024] FIG. 2 is an exploded perspective view of a part of the fluid pressure actuator 10. As shown in FIG. 2, the fluid pressure actuator 10 includes an actuator main body portion 100 and a sealing mechanism 200.

[0025] As described above, the actuator main body portion 100 is composed of a tube 110 and a sleeve 120.

[0026] The tube 110 is a cylindrical tubular body that expands and contracts by the pressure of a fluid. The tube 110 is made of an elastic material such as butyl rubber in order to repeat contraction and expansion by the fluid. The inner diameter Φ of the tube 110 is not particularly limited, but in this embodiment, it is about 10 mm.

[0027] When the fluid pressure actuator 10 is driven by hydraulic pressure, as the material of the tube 110, NBR (nitrile rubber) with high oil resistance, or at least one selected from the group consisting of NBR, hydrogenated NBR, chloroprene rubber, and epichlorohydrin rubber may be used.

[0028] The sleeve 120 is cylindrical and covers the outer peripheral surface of the tube 110. The sleeve 120 is a structure in which cords oriented in a predetermined direction are woven, and a rhombus shape is repeated as the oriented cords intersect. By having such a shape, the sleeve 120 undergoes a pantograph deformation and follows while restricting the contraction and expansion of the tube 110.

[0029] As the cord constituting the sleeve 120, it is preferable to use a fiber cord of aromatic polyamide (aramid fiber) or polyethylene terephthalate (PET). However, it is not limited to such types of fiber cords. For example, high-strength fibers such as PBO fiber (polyparaphenylene benzobisoxazole) or a metal cord composed of extremely fine filaments may also be used.

[0030] The sealing mechanism 200 seals the end portion in the axial direction D of the actuator main body portion 100. The sealing mechanism 200 is composed of a sealing member 210, a locking wire 220, and a caulking ring 230. AX The actuator main body portion 100 is inserted through the sealing member 210. As the sealing member 210, a metal such as stainless steel can be preferably used, but it is not limited to such a metal, and a hard plastic material or the like may be used.

[0031] The locking wire 220 locks the sleeve 120 to the sealing member 210. In the present embodiment, the locking wire 220 constitutes a locking member. Specifically, the sleeve 120 is folded back radially outward via the locking wire 220 (not shown in FIG. 2, see FIG. 3).

[0032] In the present embodiment, the locking wire 220 is formed by winding a wire having a diameter of about 1 mm a plurality of times. R For example, the locking wire 220 can be formed of a metal material, but a material that is relatively soft and rich in ductility and malleability, such as a material containing aluminum (such as an aluminum alloy), is preferable. The member forming the locking wire 220 is preferably more deformable than the member forming the sealing member 210, and more preferably more deformable than the member forming the caulking ring 230.

[0033]

[0034]

[0035] ​​Note that, as the locking wire 220, the same metal as that of the sealing member 210 may be used, or the same metal as that of the caulking ring 230 may be used.

[0036] Note that the locking wire 220 is formed of a material (not necessarily limited to metal) having a hardness such that it deforms when caulked together with the caulking ring 230 as will be described later. Further, instead of the locking wire 220 (locking member), it may be formed of a ring-shaped member.

[0037] The caulking ring 230 is provided on the outer peripheral surface of the actuator main body portion 100 inserted through the sealing member 210, and restrains the actuator main body portion 100. In the present embodiment, the caulking ring 230 constitutes a restraining member.

[0038] The caulking ring 230 caulks the actuator main body portion 100 together with the sealing member 210. As the caulking ring 230, metals such as aluminum alloy, brass, and iron can be used. When the caulking ring 230 is caulked by a caulking jig, an indentation 231 (see FIG. 1) is formed.

[0039] The caulking jig is not particularly limited, but the actuator main body portion 100 is restrained by caulking a plurality of dies (for example, dies divided into seven on the circumference) in contact with the outer peripheral surface of the caulking ring 230 radially inward, and an axial direction D AX a linear indentation 231 along is formed.

[0040] (2) Configuration of the Sealing Mechanism Next, with reference to FIGS. 3 and 4, the specific configuration of the sealing mechanism 200 will be described. FIG. 3 is a partial cross-sectional view along the axial direction D of the sealing mechanism 200. AX FIG. 4 is a partial cross-sectional view along the axial direction D of the sealing mechanism 200 before the caulking ring 230 is caulked. AX is a partial cross-sectional view along.

[0041] As shown in FIGS. 3 and 4, the sealing member 210 includes a head portion 211, a body portion 212, and an intermediate portion 213.

[0042] The head 211 is provided outside the body portion 212 in the axial direction D AX In this case, a connection port 211a is formed in the head 211.

[0043] The connection port 211a is connected to a hose (pipe line) connected to a drive pressure source of the fluid pressure actuator 10, specifically, a compressor of gas or liquid.

[0044] Also, the head 211 has a contact surface 211b that contacts the end surface 232 of the caulking ring 230 in the axial direction D AX The contact surface 211b, which is a flat surface that can be in surface contact with the end surface 232.

[0045] The body portion 212 is a portion through which the tube 110 (see FIGS. 1 and 2) is inserted. Specifically, the body portion 212 contacts the inner peripheral surface of the tube 110 inserted through the sealing member 210.

[0046] On the outer peripheral surface of the body portion 212, a stepped portion 212a is formed to prevent the tube 110 from coming off the sealing member 210. The stepped portion 212a protrudes radially outward in the direction D R so as to provide resistance to the pulling direction of the tube 110 from the body portion 212.

[0047] The intermediate portion 213 is provided between the body portion 212 and the head 211. The intermediate portion 213 is smaller in size in the radial direction D than the head 211 R . Note that only a part of the intermediate portion 213 in the axial direction D may be smaller in size in the radial direction D than the head 211 AX . R For example, the intermediate portion 213 near the head 211 in the axial direction D is smaller in size in the radial direction D than the head 211, and the intermediate portion 213 near the body portion 212 has the same size in the radial direction D as the head 211

[0048] For example, in the axial direction D AX The intermediate portion 213 near the head 211 is smaller in size in the radial direction D than the head 211, and the intermediate portion 213 near the body portion 212 is the same size in the radial direction D as the head 211 R . RThe size may be equal or slightly larger. In this embodiment, the diameter Φ of the intermediate portion 213 near the head 211 is about 8 mm.

[0049] The intermediate portion 213 may be interpreted as the region from the position of the end face 232 of the caulking ring 230 to the outer end of the tube 110 inserted into the body portion 212 in the axial direction D AX

[0050] The intermediate portion 213 has a diameter-expanded portion 214 that bulges outward in the radial direction of the actuator main body portion 100 more than the body portion 212. The locking wire 220 around which the sleeve 120 is folded back may be locked by the diameter-expanded portion 214. That is, the diameter formed by the locking wire 220 is smaller than the diameter of the diameter-expanded portion 214.

[0051] The diameter-expanded portion 214 is convex outward in the radial direction D from the body portion 212. The diameter-expanded portion 214 may become larger as it goes from the head 211 toward the body portion 212. That is, the intermediate portion 213 may have a portion where the diameter (diameter size) gradually increases as it goes from the head 211 toward the body portion 212. In other words, the intermediate portion 213 may have a tapered portion in the cross section as shown in FIG. 3. The tapered portion may be interpreted as the diameter-expanded portion 214. R

[0052] Thus, since the intermediate portion 213 has the diameter-expanded portion 214 whose diameter gradually increases as it goes from the head 211 toward the body portion 212, the distance between the caulking ring 230 (constraint member) and the intermediate portion 213 becomes narrower as it goes from the head 211 toward the body portion 212.

[0053] In this embodiment, the maximum diameter Φ of the diameter-expanded portion 214 is about 13 mm. As described above, since the diameter Φ of the intermediate portion 213 near the head 211 is about 8 mm, the step between the diameter-expanded portion 214 and the intermediate portion 213 near the head 211 is about 2.5 mm.

[0054] Inside the sealing member 210, in the axial direction D AX ​​A through hole 215 is formed along [it]. The through hole 215 communicates with the connection port 211a, and fluid flows into the actuator main body 100 through the through hole 215. In this embodiment, the diameter Φ of the through hole 215 is about 3 mm.

[0055] Also, a connecting portion 216 is provided on the sealing member 210. Specifically, the connecting portion 216 is provided on the outer side in the axial direction D of the head portion 211. An engaging hole 216a is formed in the connecting portion 216 to engage members such as those constituting the device using the fluid pressure actuator 10. AX As described above, the tube 110 is inserted into the body portion 212. As described above, the diameter-expanded portion 214 abuts against the end face 111 of the tube 110 (see also FIG. 2). Further, the stepped portion 212a bites into the inner peripheral surface of the tube 110 when the actuator main body 100 is caulked together with the sealing member 210 by the caulking ring 230, more reliably preventing the tube 110 from coming out of the body portion 212.

[0056] As described above, the tube 110 is inserted into the body portion 212. As described above, the diameter-expanded portion 214 abuts against the end face 111 of the tube 110 (see also FIG. 2). Further, the stepped portion 212a bites into the inner peripheral surface of the tube 110 when the actuator main body 100 is caulked together with the sealing member 210 by the caulking ring 230, more reliably preventing the tube 110 from coming out of the body portion 212.

[0057] The locking wire 220 is provided on the outer peripheral surface of the sleeve 120 and is formed by winding a wire around the outer peripheral surface of the intermediate portion 213. The sleeve 120 is folded back toward the center side in the axial direction D via the locking wire 220. That is, the end portion in the axial direction D of the sleeve 120 is folded back via the locking wire 220 (locking member). AX As described above, the tube 110 is inserted into the body portion 212. As described above, the diameter-expanded portion 214 abuts against the end face 111 of the tube 110 (see also FIG. 2). Further, the stepped portion 212a bites into the inner peripheral surface of the tube 110 when the actuator main body 100 is caulked together with the sealing member 210 by the caulking ring 230, more reliably preventing the tube 110 from coming out of the body portion 212. AX As described above, the tube 110 is inserted into the body portion 212. As described above, the diameter-expanded portion 214 abuts against the end face 111 of the tube 110 (see also FIG. 2). Further, the stepped portion 212a bites into the inner peripheral surface of the tube 110 when the actuator main body 100 is caulked together with the sealing member 210 by the caulking ring 230, more reliably preventing the tube 110 from coming out of the body portion 212.

[0058] Specifically, the sleeve 120 has a folded-back portion 120a folded back via the locking wire 220. Also, the folded-back portion 120a is folded back outward in the radial direction D via the locking wire 220 and abuts against the inner peripheral surface of the caulking ring 230. R As described above, the tube 110 is inserted into the body portion 212. As described above, the diameter-expanded portion 214 abuts against the end face 111 of the tube 110 (see also FIG. 2). Further, the stepped portion 212a bites into the inner peripheral surface of the tube 110 when the actuator main body 100 is caulked together with the sealing member 210 by the caulking ring 230, more reliably preventing the tube 110 from coming out of the body portion 212.

[0059] Also, as described above, the contact surface 211b of the head portion 211 abuts against the end face 232 of the caulking ring 230. Specifically, the contact surface 211b is in surface contact with the end face 232.

[0060] The caulking ring 230 fixes the actuator main body 100 to the sealing member 210 by caulking the folded sleeve 120 together with the tube 110 and the locking wire 220 to the sealing member 210.

[0061] Also, when the locking wire 220 is caulked together with the actuator main body 100 by a caulking jig for caulking the caulking ring 230, it is compressed and deformed to fill the space formed between the caulking ring 230 and the intermediate portion 213.

[0062] Specifically, from the state shown in FIG. 4, when the locking wire 220 is caulked by the jig, it deforms so as to be crushed and deforms so that the gap in the space between the caulking ring 230 and the intermediate portion 213 decreases.

[0063] As a result, at least a part of the locking wire 220 is compressed and deformed to form a compression deformation portion 221. The compression deformation portion 221 may be formed in a larger amount in a region closer to the body portion 212 where the distance between the caulking ring 230 and the intermediate portion 213 becomes narrower.

[0064] The locking wire 220 is formed of a material having anisotropy in which the strength in the axial direction D AX is lower than the strength in the radial direction D R in consideration of such ease of compression deformation.

[0065] Also, considering that the volume (A) of the space between the caulking ring 230 and the intermediate portion 213 and the volume (B) of the locking wire 220 and the sleeve 120 sufficiently fill the space and prevent the sleeve 120 from being pulled out, it is preferably 0.5A < B < 1.5A, and more preferably 0.8A < B < 1.2A.

[0066] (3) Function and Effect According to the above-described embodiment, the following functions and effects can be obtained. Specifically, the intermediate portion 213 of the sealing mechanism 200 has a radial direction D of the actuator main body 100 rather than the head portion 211.R is small in size in, it has a diameter-expanded portion 214 that bulges outward in the radial direction D of the actuator main body 100 rather than the body portion 212. Also, the locking wire 220 is compression-deformed and fills the space formed between the caulking ring 230 and the intermediate portion 213. R When caulking the sleeve 120 folded back via the tube 110 and the locking wire 220 together with the sealing member 210 in this way, the locking wire 220 is deformed, and it is possible to more reliably prevent the sleeve 120 from slipping off from the locking wire 220, making it difficult for the sleeve 120 to come off.

[0067] That is, according to the fluid pressure actuator 10, while using the locking member (locking wire 220) for locking the sleeve 120, it is possible to more reliably prevent the sleeve 120 from coming off from the sealing member 210.

[0068]

[0069] If the combined volume (B) of the volume of the locking wire 220 and the volume of the sleeve 120 surrounding the locking wire 220 is less than the volume (A) of the gap surrounded by the caulking ring 230 and the intermediate portion 213 (sealing member 210), when a force is applied in the axial direction D after caulking, AX the caulking ring 230, the sleeve 120, and the locking wire 220 are pulled in the axial direction D, AX and a gap is generated between them and the sealing member 210.

[0070] As a result, the length of the fluid pressure actuator 10 changes. Conversely, if the volume (B) of the locking wire 220 and the sleeve 120 is too large, the locking wire 220 interferes with the caulking ring 230 during caulking, inhibiting the deformation of the locking wire 220 and generating a shape distortion. By setting the volume of the locking wire 220 within an appropriate range, both problems can be solved.

[0071] ​In this embodiment, the diameter-expanded portion 214 of the sealing member 210 becomes larger as it goes from the head portion 211 toward the body portion 212. In other words, the distance between the caulking ring 230 and the intermediate portion 213 becomes narrower as it goes from the head portion 211 toward the body portion 212.

[0072] Therefore, the space between the caulking ring 230 and the intermediate portion 213 can be made smaller as it goes toward the central side in the axial direction D AX and the locking wire 220 can be more easily deformed during caulking. Thereby, it is possible to more reliably prevent the sleeve 120 from coming off the sealing member 210.

[0073] In this embodiment, the locking wire 220 may be formed of a material having anisotropy in which the strength in the axial direction D AX is lower than the strength in the radial direction D R and including at least one of, for example, copper or lead.

[0074] Therefore, compression deformation of the locking wire 220 in the axial direction D AX becomes easy, and the space between the caulking ring 230 and the intermediate portion 213 can be more reliably filled. Thereby, it is possible to more reliably prevent the sleeve 120 from coming off the sealing member 210.

[0075] In this embodiment, the locking wire 220 is formed by winding a wire around the outer peripheral surface of the intermediate portion 213. Therefore, the locking wire 220 can be easily formed in an annular shape, and the caulking operation of the actuator main body portion 100 can be facilitated.

[0076] In this embodiment, the end portion of the sleeve 120 in the axial direction D AX is folded back via the locking wire 220. Therefore, it is possible to more reliably prevent the sleeve 120 from coming off the sealing member 210.

[0077] (4) Other Embodiments Although the embodiments have been described above, it is obvious to those skilled in the art that the present invention is not limited to the description of the embodiments, and various modifications and improvements are possible.

[0078] For example, the sealing mechanism 200 may be modified as follows. FIG. 5 is a partial cross-sectional view along the axial direction D of the sealing mechanism 200A according to a modified example. AX along the axial direction D.

[0079] As shown in FIG. 5, the sealing mechanism 200A includes a sealing member 210A and a locking wire 220A. In the sealing member 210A, the shape of the diameter-expanded portion 214A is different from that of the diameter-expanded portion 214 described above. The diameter-expanded portion 214 has a shape in which the diameter size increases as it goes toward the central side (body portion 212) in the axial direction D, but may have a uniform diameter size in the axial direction D as in the diameter-expanded portion 214A. AX toward the central side (body portion 212) in the axial direction D, but may have a uniform diameter size in the axial direction D as in the diameter-expanded portion 214A. AX in the axial direction D and may have a uniform diameter size.

[0080] The locking wire 220A is the same as the locking wire 220 described above. However, the volume of the locking wire 220A may be changed according to the shape of the sealing member 210A (the space between the caulking ring 230 and the intermediate portion 213). Even in the case of such a sealing mechanism 200A, the locking wire 220A can be compressed and deformed during caulking to fill the space. Thereby, it is possible to more reliably prevent the sleeve 120 from coming off the sealing member 210.

[0081] Also, in the above-described embodiment, the end portion of the sleeve 120 in the axial direction D AX was folded back via the locking wire 220, but the end portion does not necessarily have to be folded back via the locking wire 220.

[0082] Furthermore, in the above-described embodiment, the locking wire 220 was formed by winding the wire a plurality of times, but the locking member may be formed by a ring-shaped member instead of the locking wire 220.

[0083] As described above in detail, it is obvious to those skilled in the art that the present disclosure is not limited to the embodiments described in the present disclosure. The present disclosure can be implemented in modified and changed 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 for illustrative purposes only and has no restrictive meaning for the present disclosure.

Explanation of Signs

[0084] 10 Fluid pressure actuator 100 Actuator main body part 110 Tube 111 End face 120 Sleeve 120a Folded-back part 200, 200A Sealing mechanism 210, 210A Sealing member 211 Head 211a Connection port 211b Contact surface 212 Body part 212a Step-like part 213 Intermediate part 214, 214A Diameter-expanded part 215 Through hole 216 Connecting part 216a Engaging hole 220, 220A Locking wire 221 Compression deformation part 230 Crimping ring 231 Indentation 232 End face 233 Chamfered part 300 Sealing mechanism

Claims

1. An actuator body portion composed of a cylindrical tube that expands and contracts by the pressure of a fluid, and a sleeve that covers the outer peripheral surface of the tube and has a structure in which cords oriented in a predetermined direction are woven in, In the axial direction of the actuator body portion, a sealing mechanism for sealing the end portion of the actuator body portion A fluid pressure actuator comprising: The sealing mechanism is A sealing member through which the actuator body portion is inserted, A restraining member provided on the outer peripheral surface of the actuator body portion inserted through the sealing member for restraining the actuator body portion, A locking member for locking the sleeve to the sealing member Comprising, The sealing member is A body portion through which the tube is inserted, A head portion provided outside the body portion in the axial direction, An intermediate portion provided between the body portion and the head portion Having, The intermediate portion is Smaller in size in the radial direction of the actuator body portion than the head portion, Having a diameter-expanded portion that bulges outward in the radial direction of the actuator body portion more than the body portion, The locking member is compressed and deformed to fill the space formed between the restraining member and the intermediate portion, The diameter-expanded portion has a diameter size that increases from the head portion toward the body portion, a fluid pressure actuator.

2. An actuator body portion composed of a cylindrical tube that expands and contracts by the pressure of a fluid, and a sleeve that covers the outer peripheral surface of the tube and has a structure in which cords oriented in a predetermined direction are woven in, In the axial direction of the actuator body portion, a sealing mechanism for sealing the end portion of the actuator body portion A fluid pressure actuator comprising: The sealing mechanism is A sealing member through which the actuator body portion is inserted, A restraining member provided on the outer peripheral surface of the actuator body portion inserted through the sealing member for restraining the actuator body portion, A locking member for locking the sleeve to the sealing member Comprising, The sealing member is A body portion through which the tube is inserted, A head portion provided outside the body portion in the axial direction, An intermediate portion provided between the body portion and the head portion Having, The intermediate portion is Smaller in size in the radial direction of the actuator body portion than the head portion, Having a diameter-expanded portion that bulges outward in the radial direction of the actuator body portion more than the body portion, The locking member is compressed and deformed to fill the space formed between the restraining member and the intermediate portion. A fluid pressure actuator in which the distance between the restraining member and the intermediate portion becomes narrower as it goes from the head portion toward the body portion. **Claim 3** The fluid pressure actuator according to claim 2, wherein the diameter of the enlarged diameter portion increases as it goes from the head portion toward the body portion. **Claim 4** The fluid pressure actuator according to claim 1, wherein the distance between the restraining member and the intermediate portion becomes narrower as it goes from the head portion toward the body portion. **Claim 5** The fluid pressure actuator according to any one of claims 1 to 4, wherein the locking member is formed of a material having anisotropy in which the axial strength is lower than the radial strength. **Claim 6** The fluid pressure actuator according to any one of claims 1 to 4, wherein the locking member is formed of a material containing aluminum. **Claim 7** The fluid pressure actuator according to any one of claims 1 to 6, wherein the locking member is formed by winding a wire around the outer peripheral surface of the intermediate portion. **Claim 8** The fluid pressure actuator according to any one of claims 1 to 7, wherein the end portion of the sleeve in the axial direction is folded back via the locking member.

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