Fluid pressure actuator

Abstract

To provide a fluid pressure actuator in which the length in an arrangement direction, which is a direction that a pair of tubes are arranged, is reduced about a sealing member in a fluid pressure actuator.SOLUTION: A fluid pressure actuator 20 includes: a sealing member 30 for sealing end parts of respective tubes 24 in which an insertion part 50 pair having a pair of insertion parts 50 into which end parts in an axial direction X of the tubes 24 of a tube 24 pair are inserted is formed; and a restraint member 28 provided over one end side to the other end side in the axial direction X of the tube 24 pair, which is sandwiched by opposed parts where the respective tubes 24 are opposed to each other. In each of the insertion parts 50, the length in the width direction Y orthogonal to the arrangement direction Z that the insertion parts 50 are arranged viewed in the axial direction X is longer than the length in the arrangement direction Z.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to a fluid pressure actuator.

Background Art

[0002] Patent Document 1 discloses a fluid pressure actuator including a cylindrical tube that expands and contracts by the pressure of a fluid, a stretchable structure in which fiber cords oriented in a predetermined direction are woven, a sleeve that covers the outer peripheral surface of the tube, and a sealing member that seals the end portions of the tube in the axial direction. The tubes are provided in a plurality of rows along a direction orthogonal to the axial direction, and a restraint member is provided across the opposing portions where adjacent tubes face each other, from one end side to the other end side in the axial direction of the tube. The restraint member resists compression along the axial direction and is deformable in the orthogonal direction.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the configuration described in Patent Document 1, the sealing member of the fluid pressure actuator has a large length in the arrangement direction, which is the direction in which a pair of tubes are arranged.

[0005] An object of the present disclosure is to provide a fluid pressure actuator in which the length of the sealing member in the fluid pressure actuator in the arrangement direction, which is the direction in which a pair of tubes are arranged, is reduced.

Means for Solving the Problems

[0006] The fluid pressure actuator of the first aspect includes a pair of tubes arranged in parallel that expand and contract by the pressure of a fluid, a sleeve that covers the outer peripheral surfaces of the pair of tubes and expands the tubes in the radial direction while restricting axial elongation of the tubes due to expansion of the tubes, a pair of insertion parts in which end parts in the axial direction of the tubes of the pair of tubes are respectively inserted, a sealing member that seals the end parts of the respective tubes, and a restraint member provided from one end side in the axial direction to the other end side of the pair of tubes and sandwiched between opposing parts where the respective tubes face each other. Each of the insertion parts has a length in the width direction, which is orthogonal to the alignment direction in which the insertion parts are aligned as viewed from the axial direction, that is longer than the length in the alignment direction.

[0007] In the fluid pressure actuator according to this aspect, each of the insertion parts has a length in the width direction that is longer than the length in the alignment direction. As a result, the cross-sectional area of the tube inserted into the insertion part can be increased as compared with the case where the length in the alignment direction and the length in the width direction of the insertion part are equal.

[0008] The fluid pressure actuator of the second aspect is the fluid pressure actuator according to the first aspect, wherein the pair of insertion parts is oval-shaped.

[0009] In the fluid pressure actuator according to this aspect, the shape of the insertion part is oval with the width direction being long. Therefore, according to the fluid pressure actuator according to this aspect, the manufacturing cost of the sealing member can be reduced as compared with the case where the shape of the pair of insertion parts is not oval with the width direction being long.

[0010] The fluid pressure actuator of the third aspect is the fluid pressure actuator according to the first or second aspect, wherein the sealing member has a base end part that is larger in diameter than the pair of insertion parts on the outer side in the axial direction, and the restraint member has an end part in the axial direction inserted into an insertion part formed at the base end part.

[0011] In the fluid pressure actuator according to this aspect, since the end of the restraint member is inserted into the insertion portion on the outer side in the axial direction with respect to the insertion portion pair, the restraint member is less likely to shift after the fluid pressure actuator is assembled.

[0012] The fluid pressure actuator according to the fourth aspect is the fluid pressure actuator described in any one of the first aspect to the third aspect, wherein the sealing member is divided into a first sealing member in which one of the insertion portions is formed and a second sealing member in which the other of the insertion portions is formed, and the first sealing member and the second sealing member are overlapped in the alignment direction.

[0013] In the fluid pressure actuator according to this aspect, insertion portions are respectively formed in the first sealing member and the second sealing member, and a sealing portion is formed by overlapping the first sealing member and the second sealing member. Thus, according to the fluid pressure actuator according to this aspect, the manufacturing cost of the sealing member can be reduced as compared with the case where the sealing member is formed of an integral member.

[0014] The fluid pressure actuator according to the fifth aspect is the fluid pressure actuator described in the fourth aspect, wherein the first sealing member and the second sealing member have the same shape with a dividing surface interposed therebetween.

[0015] In the fluid pressure actuator according to this aspect, since the first sealing member and the second sealing member have the same shape with a dividing surface interposed therebetween, the number of types of parts of the fluid pressure actuator is reduced. Thus, according to the fluid pressure actuator according to this aspect, the manufacturing cost of the sealing member can be reduced as compared with the case where the first sealing member and the second sealing member have different shapes.

[0016] The fluid pressure actuator according to the sixth aspect is the fluid pressure actuator described in the fourth aspect or the fifth aspect, wherein when the first sealing member and the second sealing member are overlapped in the alignment direction, a plurality of fitting portions for positioning the first sealing member and the second sealing member by fitting of a boss portion and a recess portion are formed on the dividing surface.

[0017] In the fluid pressure actuator according to this aspect, a fitting portion for positioning the first sealing member and the second sealing member by fitting a boss portion and a recess, which are fitted when the first sealing member and the second sealing member are overlapped, is formed in plurality on the split surface. Accordingly, according to the fluid pressure actuator according to this aspect, the first sealing member and the second sealing member can be accurately overlapped with each other.

Effects of the Invention

[0018] According to the present disclosure, there is provided a fluid pressure actuator in which the length in the arrangement direction, which is the direction in which a pair of tubes are arranged, of the sealing member in the fluid pressure actuator is reduced.

Brief Description of the Drawings

[0019]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Modes for Carrying Out the Invention

[0020] Hereinafter, embodiments for realizing the technology of the present disclosure will be described in detail with reference to the drawings.

[0021] In addition, for components and processes that perform the same functions, the same reference numerals are given throughout the drawings, and duplicate explanations may be omitted as appropriate. Further, the present disclosure is not limited to the following embodiments, and can be implemented with appropriate modifications within the scope of the object of the present disclosure.

[0022] Note that the "arrow Z+ direction" and "arrow Z- direction" in each drawing are examples of the axial direction X in the present disclosure. Also, the "arrow Y+ direction" and "arrow Y- direction" in each drawing are examples of one of the alignment directions Z in the present disclosure. Further, the "arrow X+ direction" and "arrow X- direction" in each drawing are examples of the width direction Y in the present disclosure.

[0023] In the following description, "one side" refers to the "+" side of the arrows X, Y, and Z, and "the other side" refers to the "-" side of the arrows X, Y, and Z. That is, when the axial direction X, the alignment direction Z, and the width direction Y are described without "one side" or "the other side", it may refer to both the "+" side and the "-" side.

[0024] <Configuration of the fluid pressure actuator 20> FIG. 1 shows a fluid pressure actuator 20 according to an embodiment of the present disclosure. The fluid pressure actuator 20 includes an actuator main body 22, a sealing member 30, and a sealing member 31.

[0025] As also shown in FIG. 2, the actuator main body 22 has a pair of tubes 24, a sleeve 26, a restraining member 28, a locking ring 34, and a caulking member 36.

[0026] The tube 24 is a cylindrical member that can expand and contract due to elastic deformation, and expands and contracts due to a change in the pressure of the fluid inside. Note that the longitudinal direction of the tube 24 coincides with the axial direction X in the state where the fluid pressure actuator 20 is assembled. Also, as shown in FIG. 2, the tubes 24 are arranged in parallel in the state where the fluid pressure actuator 20 is assembled.

[0027] Note that the tube 24 can be made of an elastic material such as butyl rubber. As the fluid supplied to the tube 24, air can be used. In this case, the fluid pressure actuator 20 becomes a pneumatic actuator. When the fluid pressure actuator 20 is hydraulically driven, it is preferably made of at least one selected from the group consisting of NBR (nitrile rubber) with high oil resistance, hydrogenated NBR, chloroprene rubber, and epichlorohydrin rubber.

[0028] The sleeve 26 is a cylindrical member that covers the outer periphery of the tube 24. The sleeve 26 is a stretchable structure in which fiber cords oriented in a predetermined direction are woven, and the oriented cords intersect at a predetermined angle θ with respect to the axial direction X. By having such a shape, the sleeve 26 undergoes a pantograph deformation that changes the angle θ and follows the contraction and expansion of the tube 24 while restricting the contraction and expansion of the tube 24.

[0029] As the cords constituting the sleeve 26, it is preferable to use fiber cords of aromatic polyamide (aramid fiber) or polyethylene terephthalate (PET). However, it is not limited to such types of fiber cords, and for example, cords of other high-strength fibers such as PBO fiber (polyparaphenylene benzobisoxazole) may also be used.

[0030] The restraint member 28 is provided between a pair of tubes 24. The restraint member 28 is in the shape of a long plate and is arranged such that its longitudinal direction is along the axial direction X of the tube 24, and it is arranged from one end to the other end of the tube 24 while touching a part of the outer periphery of the tube 24. More specifically, as shown in FIG. 8 described later, the restraint member 28 is sandwiched between the opposing portions where a pair of tubes 24 face each other in a state where the fluid pressure actuator 20 is assembled.

[0031] Note that the restraint member 28 is formed of a material that does not expand or contract under pressure and is capable of flexurally deforming in a direction in which the ends approach each other. As the restraint member 28, a so-called leaf spring can be used. The dimensions of the leaf spring are determined according to the size and specifications of the fluid pressure actuator 20, such as the magnitude of the force that causes the actuator main body 22 to bend and deform (see also FIG. 8). Also, the material of the leaf spring is not particularly limited, but typically, a material that is easily flexurally deformable and resistant to compression, such as a metal like stainless steel, may be used. Alternatively, it may be formed of a thin plate of carbon fiber reinforced plastic (CFRP) or the like.

[0032] The locking ring 34 is a ring-shaped member that is disposed outside the sleeve 26 so as to sandwich the sleeve 26 between itself and a locking portion 58 to be described later, and locks the sleeve 26 to the semi-base end portion 40. As a result, the sleeve 26 is folded back to the outer periphery via the locking ring 34. Note that the locking ring 34 can be made of a material such as metal, hard plastic, fiber, or rubber.

[0033] The caulking member 36 is disposed so as to cover a portion of the outer periphery of the actuator main body 22 where the insertion portion 50 is inserted, and crimps the actuator main body 22 to the insertion portion 50 to be described later. As a result, the actuator main body 22 is fixed to the insertion portion 50 of a sealing member 30 to be described later. As the caulking member 36, a metal such as an aluminum alloy, brass, or iron can be used.

[0034] As shown in FIGS. 3 to 7, the sealing member 30 has a first sealing member 30A and a second sealing member 30B that are separated in the middle of the arrangement direction Z. First, the first sealing member 30A will be described with reference to FIGS. 3 to 5. In the following description, the side on which the actuator main body 22 is located as viewed from the sealing member 30 and the sealing member 31 may be referred to as the inner side in the axial direction X.

[0035] The first sealing member 30A has a semi-base end portion 40 and an insertion portion 50. The semi-base end portion 40 has a mounting portion 32, a locking portion 58, and a large-diameter portion 54.

[0036] Note that, as shown in FIGS. 3 and 4, the mounting portion 32, the locking portion 58, and the large-diameter portion 54 are each formed in a substantially semi-cylindrical shape. Further, the centers of the arcs in the mounting portion 32, the locking portion 58, and the large-diameter portion 54 (the center in the full circle when the arc extends over the entire circumference) are arranged along the axial direction X and coincide with the central axis S of the fluid pressure actuator 20 in the assembled state as described later. In the following description, the chord side (arrow Z− side) of the semi-circle in the mounting portion 32, the locking portion 58, and the large-diameter portion 54 may be referred to as the "back side", and the opposite side (arrow Z+ side) may be referred to as the "front side". Further, in the following description, when referring to the diameters of the mounting portion 32, the locking portion 58, and the large-diameter portion 54, it shall refer to the diameter of the semi-circle (twice the radius of the semi-circle).

[0037] Also, the dividing surface 33, which is the surface on the back side of the semi-base end portion 40, is a flat surface along the axial direction X passing through the midpoint in the arrangement direction Z of the sealing member 30 as shown in FIG. 6. That is, the dividing surface 33 overlaps with the surface that divides the sealing member 30 into the first sealing member 30A and the second sealing member 30B in the arrangement direction Z as shown in FIG. 6 described later.

[0038] The mounting portion 32 has a larger diameter than the outer diameter of the tube 24, and an insertion portion 50 extends from one end side of the mounting portion 32 in the axial direction X. Further, the mounting portion 32 has a flow path R that communicates from the connection hole H on the front side through the central portion in the radial direction of the insertion portion 50 to the other end side (arrow X+ side) in the axial direction X (see also FIG. 6). An air supply hose (not shown) is connected to the connection hole H, and compressed air is supplied to the flow path R. The through hole 32T is a hole that penetrates from the surface of the mounting portion 32 to the dividing surface 33 on the outer side in the axial direction X (the right back side in the drawing in FIGS. 3 and 4) of the connection hole H of the mounting portion 32. The mounting hole 32I is a hole that penetrates from the outer surface of the mounting portion 32 in the axial direction X (the front left surface in FIG. 2) to the through hole 32T. The mounting hole 32I is, for example, a female thread into which a male threaded member (not shown) is inserted, and the fluid pressure actuator 20 is fixed to a shaft member (not shown) by the male threaded member pressing the shaft member (not shown) passed through the through hole 32T.

[0039] The locking portion 58 is a portion that extends from the inner surface of the mounting portion 32 in the axial direction X toward the other side in the axial direction X, and has a smaller diameter than the mounting portion 32 as shown in FIGS. 3 and 4. Note that the length of the locking portion 58 in the axial direction X is appropriately set according to the shape of the above-described locking ring 34.

[0040] The large-diameter portion 54 is a portion that extends from the surface on the other end side of the locking portion 58 toward the other side in the axial direction X, and has a larger diameter than the locking portion 58 as shown in FIGS. 3 and 4. Note that the length of the large-diameter portion 54 in the axial direction X is appropriately set according to the shape of the above-described caulking member 36.

[0041] A groove-shaped insertion groove 42 is formed in the split surface 33. As shown in FIG. 4, the insertion groove 42 is formed on the back side of the semi-base end portion 40 from the surface on the other end side of the large-diameter portion 54 toward the other end side in the axial direction X, and is a groove-shaped portion that is open on the large-diameter portion 54 side in the axial direction X. The shape of the insertion groove 42 is appropriately set according to the shape of the restraint member 28. More specifically, the length W in the width direction Y, which is the interval between the side wall surfaces 42S in the insertion groove 42, is slightly larger than the size of the restraint member 28 in the width direction Y. Also, the size T in the depth direction of the insertion groove 42, which is the length from the split surface 33 to the flat surface 42F in the insertion groove 42, is slightly larger than half of the thickness direction of the restraint member 28. Further, the length D in the axial direction X of the insertion groove 42, which is the length from the insertion portion 50 side to the bottom surface 42B in the insertion groove 42, is set such that in the fluid pressure actuator 20 after assembly, the restraint member 28 is not compressed in the axial direction X and the restraint member 28 is sandwiched to such an extent that one end does not come out of the insertion groove 42. An insertion portion 42H into which the end portion of the restraint member 28 can be inserted is formed by the insertion groove 42 of the first sealing member 30A and the insertion groove 42 of the second sealing member 30B described later.

[0042] As shown in FIG. 4, the boss 44 is a portion protruding from the dividing surface 33 of the mounting portion 32, and is, for example, substantially cylindrical in shape. Further, as shown in FIG. 4, the recess 46 is a circular recess in a position that is line-symmetrical with the boss 44 with respect to the central axis S of the fluid pressure actuator 20 on the dividing surface 33 of the mounting portion 32. Note that the diameter of the recess 46 is slightly larger than the diameter of the boss 44, and the depth of the recess 46 is larger than the height of the boss 44.

[0043] As shown in FIGS. 3 to 6, the insertion portion 50 is formed by a plurality of tapered portions that taper inward in the axial direction X being connected in series in the axial direction X. Further, the tapered portion of the insertion portion 50 has an oval shape that is long in the width direction Y when viewed from the axial direction X. Further, the insertion portion 50 is inserted into one end side of the tube 24.

[0044] Note that the area of the insertion portion 50 when viewed from the axial direction X is slightly larger than the cross-sectional area of the flow path R of the tube 24. More specifically, in a state where the insertion portion 50 is inserted into one end side of the tube 24, the portion having the large diameter of the tapered portion of the tube 24 is shaped such that the tube 24 deforms along the ellipse and still digs into the inner surface of the tube 24.

[0045] As the first sealing member 30A, 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.

[0046] The second sealing member 30B is a member having the same shape as the first sealing member 30A with a dividing surface 33 interposed therebetween as shown in FIG. 2. As shown in FIG. 6, the first sealing member 30A and the second sealing member 30B are configured such that the dividing surfaces 33 can be overlapped with each other. More specifically, in FIG. 6, the boss 44 of the first sealing member 30A fits into the recess 46 of the second sealing member 30B, and the boss 44 of the second sealing member 30B fits into the recess 46 of the first sealing member 30A, whereby the first sealing member 30A and the second sealing member 30B are overlapped. That is, the combination of the fitting boss 44 and the recess 46 is an example of the "fitting portion" in the present embodiment. In the present embodiment, it can be said that the fluid pressure actuator 20 has a total of two fitting portions. Further, as shown in FIG. 6, the first sealing member 30A and the second sealing member 30B are positioned by fitting the boss 44 and the recess 46, respectively.

[0047] Then, as shown in FIG. 6, in a state where the first sealing member 30A and the second sealing member 30B are overlapped with each other at the dividing surfaces 33, the combination of each pair of the insertion portions 50 is an example of the "insertion portion pair" in the embodiment. In a state where the first sealing member 30A and the second sealing member 30B are overlapped, the sealing member 30, which is a combination of the first sealing member 30A and the second sealing member 30B, is an example of the "sealing member pair" in the present embodiment. Further, as shown in FIG. 2, a pair of tubes 24 respectively inserted into the pair of insertion portions 50 is an example of the "tube pair" in the present embodiment. Further, as shown in FIG. 6, a state where the semi-base end portions 40 are combined is an example of the "base end portion" in the present embodiment. Further, as shown in FIG. 6, a state where the insertion grooves 42 face each other is an example of the "base end portion" in the present embodiment.

[0048] The sealing member 31 provided on the other end side (the right side in the drawing in FIG. 1) in the axial direction X of the fluid pressure actuator 20 has a lid portion 38 and a pair of insertion portions 50.

[0049] The lid portion 38 of the sealing member 31 is the same as the attachment portion 32 in the sealing member 30, except that the connection hole H and the flow path R are not formed therein and the tip end has an R shape. Further, the sealing member 31 is the same as the sealing member 30, except that the pair of insertion portions 50 are integrated with the lid portion 38. That is, the pair of insertion portions 50 in the sealing member 31 are another example of the "pair of insertion portions" in the present embodiment.

[0050] Subsequently, an assembly procedure of the fluid pressure actuator 20 in the present embodiment will be described.

[0051] <Assembly of Fluid Pressure Actuator 20> As shown in FIGS. 2 to 7, on one end side of the fluid pressure actuator 20 in the present embodiment, the sealing member 30 and the actuator main body portion 22 are assembled as follows.

[0052] First, the respective insertion portions 50 of the first sealing member 30A and the second sealing member 30B are inserted into the respective ones of the pair of tubes 24 until one end abuts against the large diameter portion 54.

[0053] The first sealing member 30A and the second sealing member 30B are overlapped, and one end of the restraining member 28 is inserted into the insertion portion 42H (the portion where the insertion grooves 42 face each other). Thereby, the movement of the restraining member 28 in one direction (the semi-base end portion 40 side) of the arrangement direction W, the width direction Y, and the axial direction X is restricted by the side wall surface 42S, the flat surface 42F, and the bottom surface 42B of the insertion portion 42H. In other words, the insertion portion 42H positions the restraining member 28 along the axial direction X and sandwiches the restraining member 28 between the opposing portions of the pair of tubes 24.

[0054] Next, the sleeve 26 is hung up to the locking portion 58 of the tube 24 and the sealing member 30 while covering the outer peripheral surface of the restraining member 28, and the locking ring 34 is attached at the position of the locking portion 58 from the radially outer side of the sleeve 26 to lock the sleeve 26 to the locking portion 58.

[0055] Next, fold the sleeve 26 back to the insertion portion 50 of the sealing member 30 such that the locking ring 34 is on the inner side, and arrange the caulking member 36 from the radially outer side of the sleeve 26 so as to span the insertion portion 50 and the locking portion 58, and crimp them with a crimping machine (not shown). As a result, at one end of the actuator body portion 22 in the axial direction X, the tube 24, the restraint member 28, and the sleeve 26 are fixed to the sealing member 30.

[0056] Next, on the other side of the tube 24, the sleeve 26, and the restraint member 28 in the axial direction X, insert the restraint member 28 into the insertion portion 42H of the sealing member 31.

[0057] Next, while taking care that the restraint member 28 does not come off from the insertion portion 42H of the sealing member 31, insert each of the pair of insertion portions 50 of the sealing member 31 into the other side of the pair of tubes 24 in the axial direction X, respectively.

[0058] Next, cover the outer peripheral surface of the restraint member 28 while hanging the sleeve 26 up to the locking portion 58 of the tube 24 and the sealing member 31, and lock the sleeve 26 to the locking portion 58 by attaching the locking ring 34 from the radially outer side of the sleeve 26 at the position of the locking portion 58.

[0059] Next, fold the sleeve 26 back to the insertion portion 50 of the sealing member 31 such that the locking ring 34 is on the inner side, and arrange the caulking member 36 from the radially outer side of the sleeve 26 so as to span the insertion portion 50 and the locking portion 58, and crimp them with a crimping machine (not shown). As a result, at the other end of the actuator body portion 22 in the axial direction X, the tube 24, the restraint member 28, and the sleeve 26 are fixed to the sealing member 31.

[0060] By sealing one end and the other end of the tube 24 to the sealing member 30 and the sealing member 31 by the above procedure, the fluid pressure actuator 20 is assembled.

[0061] Subsequently, the operation of the fluid pressure actuator 20 in the present disclosure will be described.

[0062] <Operation of the fluid pressure actuator 20> As shown in FIG. 8, one end sealing member 30 of the fluid pressure actuator 20 is fixed to a robot hand (not shown) or the like, and the other end sealing member 31 is used as a free end.

[0063] First, with the airtightness of the second sealing member 30B released, when compressed air is introduced into the connection hole H of the first sealing member 30A, the pressure in the tube 24 connected to the first sealing member 30A rises. The tube 24 connected to the first sealing member 30A elastically deforms and expands due to the increase in internal pressure. The sleeve 26 undergoes a pantograph deformation so that the angle θ increases, and a force acts in the direction of shortening the length of the actuator main body 22. At this time, since the shortening of the actuator main body 22 is restricted by the restraint member 28 disposed at the opposing portion where the pair of tubes 24 are arranged, the outer peripheral wall on the side where the first sealing member 30A is disposed shortens when viewed from the axial direction X. As a result, the restraint member 28 bends and deforms, and as shown by the two-dot chain line in FIG. 8, the entire actuator main body 22 curves toward the left side of the drawing.

[0064] Similarly, with the airtightness of the first sealing member 30A released, when compressed air is introduced into the connection hole H of the second sealing member 30B, the outer peripheral wall on the side where the second sealing member 30B is disposed shortens when viewed from the axial direction X of the actuator main body 22. As a result, the restraint member 28 bends and deforms, and as shown by the two-dot chain line in FIG. 8, the entire actuator main body 22 curves toward the right side of the drawing.

[0065] In the present disclosure, since the restraint member 28 has a length in the width direction Y, it is difficult to bend in a direction other than the plate thickness direction, that is, the arrangement direction Z intersecting the axial direction X in the sealing member 30 and the sealing member 31.

[0066] Thus, in the fluid pressure actuator 20 of the present embodiment, by supplying compressed air to the tube 24 of the first sealing member 30A or the second sealing member 30B, the fluid pressure actuator 20 can be bent and deformed toward the side of the sealing member 30 to which the compressed air is supplied. In other words, the fluid pressure actuator 20 in the present embodiment can be bent and deformed toward both sides in the alignment direction Z by supplying compressed air to any one of the sealing members 30.

[0067] Subsequently, the operation and effects of the fluid pressure actuator 20 according to the present disclosure will be described.

[0068] <Operation and effects> In addition, in the fluid pressure actuator 20 according to the present embodiment, the length of the insertion portion 50 in the width direction Y is longer than the length in the alignment direction Z. As a result, the cross-sectional area of the tube 24 inserted into the insertion portion 50 can be increased as compared with the case where the length of the insertion portion 50 in the alignment direction Z and the length in the width direction Y are equal. In other words, by increasing the cross-sectional area of the tube 24, the strength of the force with which the fluid pressure actuator 20 bends in the alignment direction Z can be increased as compared with the case where the length of the insertion portion 50 in the alignment direction Z and the length in the width direction Y are equal.

[0069] In addition, in the fluid pressure actuator 20 according to the present embodiment, the shape of the insertion portion 50 is an oval shape with a long width direction Y. Thus, according to the fluid pressure actuator 20 according to the present embodiment, the manufacturing cost of the sealing member 30 can be reduced as compared with the case where the shape of the insertion portion 50 is not an oval shape with a long width direction Y.

[0070] In addition, in the fluid pressure actuator 20 according to the present embodiment, since the end of the restraining member 28 is inserted into the insertion portion 42H outside the insertion portion 50 in the axial direction X, the restraining member 28 is less likely to be displaced after the fluid pressure actuator 20 is assembled.

[0071] In addition, in the fluid pressure actuator 20 according to the present embodiment, insertion portions 50 are respectively formed in the first sealing member 30A and the second sealing member 30B, and a sealing portion is formed by overlapping the first sealing member 30A and the second sealing member 30B. Thus, according to the fluid pressure actuator 20 according to the present embodiment, the manufacturing cost of the sealing member 30 can be reduced as compared with the case where the sealing member 30 is formed of an integral member.

[0072] In addition, in the fluid pressure actuator 20 according to the present embodiment, since the first sealing member 30A and the second sealing member 30B have the same shape with the dividing surface 33 therebetween, the number of types of parts of the fluid pressure actuator 20 is reduced. Thus, according to the fluid pressure actuator 20 according to the present embodiment, the manufacturing cost of the sealing member 30 can be reduced as compared with the case where the first sealing member 30A and the second sealing member 30B have different shapes.

[0073] In addition, in the fluid pressure actuator 20 according to the present embodiment, when the first sealing member 30A and the second sealing member 30B are overlapped, fitting portions for positioning the first sealing member 30A and the second sealing member 30B by fitting of the boss 44 and the recess 46 are formed in total two on the dividing surface 33. Thus, according to the fluid pressure actuator 20 according to the present embodiment, the first sealing member 30A and the second sealing member 30B can be accurately overlapped. In addition, since the fluid pressure actuator 20 according to the present embodiment has a total of two fitting portions, when the first sealing member 30A and the second sealing member 30B are overlapped, the possibility of combining them in the wrong orientation can be suppressed. In addition, since the fluid pressure actuator 20 according to the present embodiment has a total of two fitting portions, it is possible to prevent the overlapped first sealing member 30A and second sealing member 30B from rotating with respect to each other about the dividing surface 33.

[0074] [Modification Example] In the above description, the shape of the insertion portion 50 was an oval shape with a long width direction Y. However, the technology of the present disclosure is not limited to this. The insertion portion 50 only needs to be long in the width direction Y. For example, the outer side in the arrangement direction Z (the side opposite to the facing portion) may be arc-shaped.

[0075] Also, in the above description, the end portion of the sealing member 30 in the axial direction X was sandwiched between the semi-base end portions 40. However, the technology of the present disclosure is not limited to this. Since the restraining member 28 only needs to be provided from one end side to the other end side in the axial direction X of the pair of tubes 24, for example, the insertion portion 42H may not be formed in the sealing member 30. In this case, both ends in the axial direction X may be configured to resist the expansion and contraction of the tube 24 by being abutted against the large-diameter portion 54 of the sealing member 30 and the large-diameter portion 54 of the sealing member 30.

[0076] Also, in the above description, the sealing member 30 is a pair of sealing members in which the first sealing member 30A having one insertion portion 50 of the pair of insertion portions and the second sealing member 30B having the other insertion portion 50 of the pair of insertion portions are overlapped in the arrangement direction Z. However, the technology according to the present disclosure is not limited to this. For example, if the pair of insertion portions 50 are formed side by side in the arrangement direction Z, the sealing member 30 may be integrally formed.

[0077] Also, in the above description, the first sealing member 30A and the second sealing member 30B have the same shape with the split surface 33 therebetween. However, the technology according to the present disclosure is not limited to this. Since it is sufficient that the sealing member 30 has the target shape by overlapping the first sealing member 30A and the second sealing member 30B, the first sealing member 30A and the second sealing member 30B may have different shapes.

[0078] In the above description, the first sealing member 30A and the second sealing member 30B each have a boss 44 and a recess 46, respectively, so that a total of two fitting portions are formed. However, the technology according to the present disclosure is not limited to this. For example, among the first sealing member 30A and the second sealing member 30B, only the boss 44 may be formed on one of them, and only the recess 46 may be formed on the other. Further, the number of fitting portions is not limited to two in total, and may be three or more if there are a plurality of them.

[0079] Even in these modified examples, those having the same configuration as the present embodiment can obtain the same operations and effects as the present embodiment.

[0080] As described above, the embodiments of the present disclosure have been described with reference to the accompanying drawings. However, it is obvious that those having ordinary knowledge in the technical field to which the present disclosure belongs can conceive of various modification examples or application examples within the scope of the technical idea described in the claims. It is naturally understood that these also belong to the technical scope of the present disclosure.

Explanation of Reference Numerals

[0081] 20 Fluid pressure actuator, 22 Actuator main body portion, 24 Tube, 26 Sleeve, 28 Restraining member, 30 Sealing member, 30A First sealing member, 30B Second sealing member, 31 Sealing member, 32 Mounting portion, 32T Through hole, 32I Mounting hole, 33 Split surface, 34 Locking ring, 36 Caulking member, 38 Lid portion, 40 Half base end portion, 42 Insertion groove, 42B Bottom surface, 42F Flat surface, 42H Insertion portion, 42S Side wall surface, 44 Boss, 46 Recess, 50 Insertion portion, 54 Large diameter portion, 58 Locking portion

Claims

1. A pair of tubes having a pair of parallel tubes that expand and contract by the pressure of a fluid, A sleeve that covers the outer peripheral surfaces of the pair of tubes and expands in the radial direction while restricting the axial elongation of the tubes due to the expansion of the tubes, A pair of insertion parts having a pair of insertion parts into which the axial ends of the tubes of the tube pair are respectively inserted, and a sealing member that seals the ends of the respective tubes, A restraint member provided from one axial end side to the other end side of the tube pair and sandwiched between opposing portions where the respective tubes face each other, Comprising, Each of the insertion parts has a length in the width direction perpendicular to the alignment direction in which the insertion parts are aligned as viewed from the axial direction, which is longer than the length in the alignment direction, A fluid pressure actuator.

2. The insertion part is oval in shape, The fluid pressure actuator according to Claim 1.

3. The sealing member has a base end portion having a larger diameter than the pair of insertion parts on the outer side in the axial direction, and the restraint member has an end portion in the axial direction inserted into an insertion portion formed in the base end portion, The fluid pressure actuator according to Claim 1.

4. The sealing member is divided into a first sealing member in which one of the insertion parts is formed and a second sealing member in which the other of the insertion parts is formed, and the first sealing member and the second sealing member are formed by being overlapped in the alignment direction, The fluid pressure actuator according to any one of Claims 1 to 3.

5. The first sealing member and the second sealing member have the same shape with a dividing surface therebetween, The fluid pressure actuator according to Claim 4.

6. When the first sealing member and the second sealing member are overlapped in the alignment direction, a plurality of fitting parts for positioning the first sealing member and the second sealing member by fitting of a boss part and a recess part are formed on the dividing surface, The fluid pressure actuator according to Claim 4.

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