Fluid pressure actuator and method for manufacturing fluid pressure actuator

Abstract

This fluid pressure actuator 20 comprises: a tube 24 pair including a pair of parallel-aligned tubes 24 that expand and contract according to the pressure of a fluid; a sealing member 30 in which is formed an insertion portion 50 pair including a pair of insertion portions 50 into which the ends of the tubes 24 in the axial direction X are respectively inserted to seal the end of each of the tubes 24; a crimping member 36 that secures the tube 24 pair to the insertion portion 50 pair from the outer side of a sleeve 26; and a filler material 60 that is disposed in a recessed space 70 around the outer circumference of the insertion portion 50 pair across the facing portions, as viewed from the axial direction X, to contact the tube 24 pair and the sleeve 26 and fill the gap.

Description

Fluid pressure actuator and method of manufacturing the fluid pressure actuator

[0001] The present disclosure relates to a fluid pressure actuator and a method for manufacturing a fluid pressure actuator.

[0002] Japanese Patent Application Laid-Open Publication No. 2021-088998 discloses a fluid pressure actuator that includes a cylindrical tube that expands and contracts due to fluid pressure, an elastic structure made of woven fiber cords oriented in a predetermined direction, a sleeve that covers the outer surface of the tube, and a sealing member that seals the axial end of the tube, wherein the tubes are arranged in a line perpendicular to the axial direction, and at the opposing portions where adjacent tubes face each other, a restraining member is provided that extends from one axial end of the tube to the other axial end, and the restraining member resists compression along the axial direction and is deformable in the orthogonal direction.

[0003] It is desirable for the fluid pressure actuator to be one that is resistant to fluid leakage when fluid pressure is applied to the tube.

[0004] An object of the present disclosure is to provide a fluid pressure actuator that is less likely to leak fluid when fluid pressure is applied to a tube, and a method for manufacturing the fluid pressure actuator.

[0005] A first aspect of the fluid pressure actuator comprises: a tube pair having a pair of tubes arranged in parallel and expanding and contracting due to fluid pressure; a sleeve covering the outer peripheral surfaces of the pair of tubes and expanding the tubes radially while restricting axial extension as the tubes expand; a pair of insertion sections having insertion sections into which axial ends of tubes of the pair of tubes are respectively inserted, and a sealing member sealing the ends of each of the tubes; a restraint member extending from one axial end side to the other axial end side of the pair of tubes and sandwiched between the opposing portions where the tubes face each other; a crimping member fixing the pair of tubes to the pair of insertion sections from the outside of the sleeve; and a filler material positioned in a recessed space on the outer periphery of the pair of insertion sections, spanning the opposing portions when viewed from the axial direction, and contacting the pair of tubes and the sleeve to fill any gaps.

[0006] When assembled by crimping with a crimping member, the fluid pressure actuator of this aspect includes a filler that is disposed in the recessed space on the outer periphery of the insertion portion pair and that contacts the tube pair and the sleeve to fill the gap. This allows the tube to be pressed against the insertion portion by the crimping member via the sealing member. Therefore, with this fluid pressure actuator, when fluid is supplied inside the tube, it is unlikely that the fluid will leak between the tube and the insertion portion.

[0007] The fluid pressure actuator of a second aspect is the fluid pressure actuator according to the first aspect, wherein the length of the pair of insertion portions in the axial direction covers the pair of insertion portions from one end to the other end.

[0008] In the fluid pressure actuator of this aspect, the axial length of the filler is set to a length that covers the entire length of the pair of insertion parts, which allows the filler to press the entire axial length of the pair of insertion parts, compared to when the axial length of the filler is shorter than the pair of insertion parts.

[0009] A fluid pressure actuator of a third aspect is the fluid pressure actuator according to the second aspect, wherein a contact portion of the filler that comes into contact with the insertion portion via the tube follows the shape of the insertion portion.

[0010] In this fluid pressure actuator, the shape of the contact portion conforms to the shape of the insertion portion, so the tube is pressed against the filler to make tight contact with the insertion portion. Therefore, when fluid is supplied inside the tube, the fluid is less likely to leak between the tube and the sealing member than when the shape of the contact portion does not conform to the shape of the insertion portion.

[0011] A fluid pressure actuator of a fourth aspect is the fluid pressure actuator according to the second aspect, wherein the filler is deformed to follow the shape of the pair of insertion portions when the crimping member presses the sleeve from outside.

[0012] In this fluid pressure actuator, the filler is deformed to conform to the shape of the insertion section pair when the crimping member fixes the tube pair to the insertion section pair, so that the tube is pressed against the filler and tightly adheres to the insertion section. Therefore, when fluid is supplied inside the tubes, the fluid is less likely to leak between the tubes and the sealing member than when the filler does not deform before or after the crimping member fixes the tube pair to the insertion section pair.

[0013] A manufacturing method for a fluid pressure actuator of a fifth aspect includes the steps of: inserting a tube pair having a pair of parallel-aligned tubes that expand and contract due to fluid pressure into an insertion section pair, the insertion section pair having insertion sections into which axial ends of the tubes are inserted, the insertion section pair having sealing members that seal the ends of the tube pair; providing restraining members at opposing portions where the tubes face each other, from one axial end side to the other axial end side of the tube pair; arranging a filler material in a recessed space on the outer periphery of the insertion section pair across the opposing portions as viewed from the axial direction; covering the outer surface of the tube pair with a sleeve that is an elastic structure woven with fiber cords oriented in a predetermined direction; and filling a gap between the tube pair and the sleeve with the filler material while fixing the tube pair to the insertion section pair using a crimping member from the outside of the sleeve.

[0014] The method for manufacturing a fluid pressure actuator according to this aspect includes the steps of: placing a filler in the recessed space on the outer periphery of the pair of insertion sections across the opposing portions when viewed from the axial direction; and filling the gap between the pair of tubes and the sleeve with the filler while fixing the pair of tubes to the pair of insertion sections. Therefore, the method for manufacturing a fluid pressure actuator according to this aspect can provide a fluid pressure actuator in which fluid is less likely to leak between the tubes and the insertion sections when fluid is supplied inside the tubes.

[0015] According to the present disclosure, a fluid pressure actuator is provided in which, when a fluid is supplied inside the tube, the fluid is less likely to leak out from between the tube and the sealing member.

[0016] FIG. 13A is a plan view of a fluid pressure actuator according to an embodiment of the present disclosure. FIG. 13B is an exploded perspective view of one axial end side of a fluid pressure actuator according to an embodiment of the present disclosure. FIG. 13C is a perspective view illustrating a front side of a first sealing member according to an embodiment of the present disclosure. FIG. 13D is a perspective view illustrating a back side of a first sealing member according to an embodiment of the present disclosure. FIG. 13E is a plan view illustrating a first sealing member according to an embodiment of the present disclosure. FIG. 13F is a side view illustrating a sealing member according to an embodiment of the present disclosure. FIG. 13G is a front view illustrating a filler included in a fluid pressure actuator according to an embodiment of the present disclosure. FIG. 13H is a perspective view illustrating a procedure for assembling a fluid pressure actuator according to an embodiment of the present disclosure. FIG. 13I is a front view of the sealing member in FIG. 10 as viewed from the axial direction. FIG. 13I is a cross-sectional view illustrating operation of a fluid pressure actuator according to an embodiment of the present disclosure. FIG. 13I is a cross-sectional view taken along line 13A-13A in FIG. 12.

[0017] Hereinafter, embodiments for realizing the technology of the present disclosure will be described in detail with reference to the drawings.

[0018] In addition, components and processes that perform the same actions and functions are given the same reference numerals throughout the drawings, and duplicated explanations may be omitted as appropriate. Furthermore, the present disclosure is not limited to the following embodiments, and can be implemented with appropriate modifications within the scope of the purpose of the present disclosure.

[0019] 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. Also, the "arrow X+ direction" and "arrow X- direction" in each drawing are examples of the width direction Y in the present disclosure.

[0020] 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. In other words, when the axial direction X, the arrangement direction Z, and the width direction Y are described without adding "one side" or "the other side," they may refer to both the "+" side and the "-" side.

[0021] 1 shows a fluid pressure actuator 20 according to an embodiment of the present disclosure. The fluid pressure actuator 20 includes an actuator body 22, a sealing member 30, and a sealing member 31.

[0022] 2 , the actuator body 22 includes a pair of tubes 24, a sleeve 26, a restraining member 28, a locking ring 34, and a crimping member 36. The fluid pressure actuator 20 according to this embodiment further includes a pair of fillers 60.

[0023] The tubes 24 are cylindrical members that can expand and contract due to elastic deformation, and expand and contract due to pressure changes of the fluid inside. Note that, when the fluid pressure actuator 20 is in an assembled state, the longitudinal direction of the tubes 24 coincides with the axial direction X. Furthermore, as shown in FIG. 2, when the fluid pressure actuator 20 is in an assembled state, the tubes 24 are arranged in parallel.

[0024] The tube 24 can be made of an elastic material such as butyl rubber. Air can be used as the fluid supplied to the tube 24, in which case the fluid pressure actuator 20 becomes a pneumatic actuator. If the fluid pressure actuator 20 is hydraulically driven, it is preferable to use at least one material selected from the group consisting of highly oil-resistant NBR (nitrile rubber), hydrogenated NBR, chloroprene rubber, and epichlorohydrin rubber.

[0025] The sleeve 26 is a cylindrical member that covers the outer periphery of the tube 24. The sleeve 26 is an elastic structure made by weaving fiber cords oriented in a predetermined direction, 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 pantograph deformation that changes the angle θ, and follows the contraction and expansion of the tube 24 while regulating this contraction and expansion.

[0026] It is preferable to use fiber cords made of aromatic polyamide (aramid fiber) or polyethylene terephthalate (PET) as the cords constituting the sleeve 26. However, the cords are not limited to these types of fiber cords, and other high-strength fiber cords such as PBO fiber (polyparaphenylene benzobisoxazole) may also be used.

[0027] The restraining member 28 is provided between the pair of tubes 24. The restraining member 28 has a long plate shape and is arranged so that its longitudinal direction is along the axial direction X of the tube 24, and is arranged from one end to the other end of the tube 24 while contacting part of the outer periphery of the tube 24. More specifically, as shown in Fig. 12 described below, the restraining member 28 is sandwiched between the opposing portions of the pair of tubes 24 when the fluid pressure actuator 20 is assembled.

[0028] The restraint member 28 is formed of a material that does not expand or contract when pressurized, and is capable of bending and deforming in the direction in which its ends approach each other. A so-called leaf spring can be used as the restraint member 28. The dimensions of the leaf spring are determined based on the magnitude of the force that bends and deforms the actuator body 22, as required by the size and specifications of the fluid pressure actuator 20 (see also FIG. 12 ). The material of the leaf spring is not particularly limited, but typically, any material that is easily bendable and resistant to compression, such as a metal such as stainless steel, may be used. Alternatively, the leaf spring may be formed of a thin plate of carbon fiber reinforced plastic (CFRP).

[0029] The locking ring 34 is a ring-shaped member that is disposed on the outside of the sleeve 26 so as to sandwich the sleeve 26 between itself and a locking portion 58 (described later), and locks the sleeve 26 to the semi-proximal end portion 40. As a result, the sleeve 26 is folded back to the outer periphery via the locking ring 34. The locking ring 34 may be made of a material such as metal, hard plastic, fiber, or rubber.

[0030] The crimping member 36 is disposed so as to cover the outer periphery of the actuator body 22 where the insertion portion 50 is inserted, and presses the actuator body 22 against the insertion portion 50, which will be described later. This fixes the actuator body 22 to the insertion portion 50 of the sealing member 30, which will be described later. The crimping member 36 can be made of a metal such as aluminum alloy, brass, or iron.

[0031] The filler 60 will be described later.

[0032] The crimping member 36 is disposed so as to cover the outer periphery of the actuator body 22 where the insertion portion 50 is inserted, and presses the actuator body 22 against the insertion portion 50, which will be described later. This fixes the actuator body 22 to the insertion portion 50 of the sealing member 30, which will be described later. The crimping member 36 can be made of a metal such as aluminum alloy, brass, or iron.

[0033] 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 in 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 of the sealing members 30 and 31 on which the actuator main body 22 is located may be referred to as the inside in the axial direction X.

[0034] The first sealing member 30A has a semi-proximal end portion 40 and an insertion portion 50. The semi-proximal end portion 40 has an attachment portion 32, a locking portion 58, and a large diameter portion 54.

[0035] 3 and 4, the mounting portion 32, the locking portion 58, and the large diameter portion 54 each have a substantially semi-cylindrical shape. The centers of the arcs of the mounting portion 32, the locking portion 58, and the large diameter portion 54 (the centers of the entire circle when the arc extends around the entire circumference) are aligned along the axial direction X and coincide with the central axis S of the fluid pressure actuator 20 in an assembled state, as described below. In the following description, the chord side of the semicircle of the mounting portion 32, the locking portion 58, and the large diameter portion 54 (the negative arrow Z side) may be referred to as the "back side," and the opposite side (the positive arrow Z side) may be referred to as the "front side." In the following description, when the diameters of the mounting portion 32, the locking portion 58, and the large diameter portion 54 are mentioned, they will refer to the diameter of the semicircle (twice the radius of the semicircle).

[0036] 6, the dividing surface 33, which is the back surface of the semi-proximal end portion 40, is a flat surface that passes through the midpoint of the sealing member 30 in the arrangement direction Z and extends along the axial direction X. That is, as shown in FIG. 6, which will be described later, the dividing surface 33 overlaps with a surface that divides the sealing member 30 into a first sealing member 30A and a second sealing member 30B in the arrangement direction Z.

[0037] The mounting portion 32 has a diameter larger than the outer diameter of the tube 24, and an insertion portion 50 extends from one end of the mounting portion 32 in the axial direction X. The mounting portion 32 also has a flow path R that communicates with a connection hole H on the front side, passing through a radial center of the insertion portion 50, and the other end in the axial direction X (the side indicated by the arrow 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 front surface to the back surface of the mounting portion 32, located outside the connection hole H of the mounting portion 32 in the axial direction X (toward the far right in FIGS. 3 and 4 ). The mounting hole 32I is a hole that penetrates from the outer surface of the mounting portion 32 in the axial direction X (the surface on the front left in FIG. 2 ) to the through hole 32T. The mounting hole 32I is, as an example, a female thread into which a male thread member (not shown) is inserted, and the male thread member presses against a shaft member (not shown) that is passed through the through hole 32T, thereby fixing the fluid pressure actuator 20 to the shaft member (not shown).

[0038] 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 Figures 3 and 4. The length of the locking portion 58 in the axial direction X is set appropriately in accordance with the shape of the locking ring 34 described above.

[0039] 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 Figures 3 and 4. The length of the large diameter portion 54 in the axial direction X is set appropriately in accordance with the shape of the above-mentioned crimping member 36.

[0040] A groove-shaped insertion groove 42 is formed in the dividing surface 33. As shown in FIG. 4 , the insertion groove 42 is formed on the back side of the half 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 to match the shape of the restraining member 28. More specifically, the length W of the insertion groove 42 in the width direction Y, which is the distance between the side wall surfaces 42S, is slightly larger than the size of the restraining member 28 in the width direction Y. Furthermore, the size T of the insertion groove 42 in the depth direction, which is the length from the dividing surface 33 to the flat surface 42F, is slightly larger than half the thickness of the restraining member 28. Furthermore, the length D of the insertion groove 42 in the axial direction X, which is the length from the insertion portion 50 side to the bottom surface 42B, is set to a degree that, in the assembled fluid pressure actuator 20, the restraining member 28 is not compressed in the axial direction X and the restraining member 28 is sandwiched to a degree that prevents one end of the restraining member 28 from slipping out of the insertion groove 42. The insertion groove 42 of the first sealing member 30A and the insertion groove 42 of the second sealing member 30B, which will be described later, form an insertion portion 42H into which an end of the restraining member 28 can be inserted.

[0041] As shown in Fig. 4, the boss 44 is a portion that protrudes from the rear surface of the mounting portion 32 toward the rear side, and is, for example, approximately cylindrical. As shown in Fig. 4, the recess 46 is a circular hole that recesses toward the front side on the rear surface of the mounting portion 32, at a position that is line-symmetrical to the boss 44 with respect to the central axis of the fluid pressure actuator 20. 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.

[0042] 3 to 6 , the insertion portion 50 has a plurality of tapered portions that are connected in the axial direction X and that taper inward in the axial direction X. The tapered portions of the insertion portion 50 have an elliptical shape that is long in the width direction Y when viewed from the axial direction X. The insertion portion 50 is inserted into one end of the tube 24.

[0043] The area of ​​the insertion portion 50 as 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, when the insertion portion 50 is inserted into one end side of the tube 24, the large-diameter portion of the tapered portion of the tube 24 is shaped to bite into the inner surface of the tube 24 even when the tube 24 is deformed along the ellipse.

[0044] The first sealing member 30A is preferably made of a metal such as stainless steel, but is not limited to such a metal and may be made of a hard plastic material or the like.

[0045] As shown in Fig. 2, the second sealing member 30B is a member that is plane-symmetrical to the first sealing member 30A, and as shown in Fig. 6, the first sealing member 30A and the second sealing member 30B can be overlapped with their back surfaces facing 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, thereby overlapping the first sealing member 30A and the second sealing member 30B.

[0046] As shown in FIG. 6 , when the first sealing member 30A and the second sealing member 30B are overlapped with their dividing surfaces 33 facing each other, the combination of the paired insertion sections 50 is an example of an “insertion section pair” in this embodiment. When the first sealing member 30A and the second sealing member 30B are overlapped, the sealing member 30, which is the combination of the first sealing member 30A and the second sealing member 30B, is an example of a “sealing member pair” in this embodiment. Also, as shown in FIG. 2 , the pair of tubes 24 inserted into the pair of insertion sections 50 is an example of a “tube pair” in this embodiment. Also, as shown in FIG. 6 , the state in which the half proximal ends 40 are combined is an example of a “proximal end” in this embodiment. Also, as shown in FIG. 6 , the state in which the insertion grooves 42 face each other is an example of a “proximal end” in this embodiment.

[0047] The sealing member 31 provided at the other end side (the right side 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 .

[0048] The lid portion 38 of the sealing member 31 is similar to the mounting portion 32 in the sealing member 30, except that the connection hole H and the flow path R are not formed and the tip is rounded. The sealing member 31 is also similar to the sealing member 30, except that the pair of insertion portions 50 are integrated with the lid portion 38. In other words, the pair of insertion portions 50 in the sealing member 31 is another example of the "pair of insertion portions" in this embodiment.

[0049] As shown in FIGS. 8 and 9, the filler 60 has an outer contact portion 64 that bulges outward and an inner contact portion 62 that is recessed inward.

[0050] 8, the outer contact portion 64 is a portion that bulges out in an arc shape when the filler 60 is viewed from the front. The arc shape of the outer contact portion 64 is shaped to match the inner diameter of the crimping member 36.

[0051] 8, the inner contact portion 62 is an arc-shaped recessed portion extending from a corner of the surface of the filler 60 opposite the outer contact portion 64 when viewed from the front. The arc shape of the inner contact portion 62 follows the curves formed on both sides of the insertion portion 50 in the width direction Y. In other words, the inner contact portion 62 is an example of a "contact portion" according to this embodiment.

[0052] The length L of the filler 60 shown in FIG. 9 is set to be equal to the length of the insertion portion 50 in the axial direction X.

[0053] As will be described later, the filler 60 is not particularly limited to a material as long as it is capable of transmitting the pressing force from the crimping member 36 via the sleeve 26 when the crimping member 36 is crimped to the pair of insertion sections 50 via the pair of tubes 24. As an example of the material of the filler 60, it is formed using a material such as polypropylene (PP) resin, which is a thermoplastic resin, or cork.

[0054] Next, the assembly procedure for the fluid pressure actuator 20 in this embodiment will be described.

[0055] <Assembly of Fluid Pressure Actuator 20> As shown in Figs. 2 and 10 to 13, at one end of the fluid pressure actuator 20 in this embodiment, the sealing member 30 and the actuator main body 22 are assembled as follows.

[0056] First, as shown in FIGS. 10 and 11, the insertion portions 50 of the first sealing member 30A and the second sealing member 30B are inserted into the pair of tubes 24 until one end abuts against the large diameter portion 54.

[0057] 10 , 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). As a result, the side wall surface 42S, flat surface 42F, and bottom surface 42B of the insertion portion 42H restrict movement of the restraining member 28 in one direction (toward the half base end portion 40) in the arrangement direction W, the width direction Y, and the axial direction X. In other words, the insertion portion 42H aligns the restraining member 28 in the axial direction X and positions the restraining member 28 so that it is sandwiched between the opposing portions of the pair of tubes 24.

[0058] As shown in FIG. 11 , when a pair of insertion sections 50 are inserted into the tube 24, a recessed space 70 is formed on the outer periphery of the pair of insertion sections 50, spanning the opposing portions of the insertion sections 50 facing each other.

[0059] 10 , in this embodiment, the filler 60 is disposed across the opposing portions of the pair of tubes 24 when viewed in the axial direction X. More specifically, the pair of fillers 60 are disposed so that the inner contact portions 62 of the pair of fillers 60 are in contact with the pair of tubes 24 on both sides of the restraint member 28 in the width direction. In other words, in this embodiment, the filler 60 is disposed in each recessed space 70 formed on the outer periphery of the pair of insertion portions 50. In other words, the filler 60 contacts the pair of tubes 24 and the sleeve 26 within the length of the pair of insertion portions 50 in the axial direction X, filling the gap in the recessed space 70.

[0060] Next, the sleeve 26 is hung up to the locking portion 58 of the tube 24 and the sealing member 30, covering the outer surface of the restraining member 28, and the locking ring 34 is attached from the radial outside of the sleeve 26 at the position of the locking portion 58, thereby locking the sleeve 26 to the locking portion 58.

[0061] Next, the sleeve 26 is folded back up to the insertion portion 50 of the sealing member 30 so that the locking ring 34 is on the inside, and the crimping member 36 is arranged from the radial outside of the sleeve 26 to span the insertion portion 50 and the locking portion 58, and is crimped together with the filler 60 using a crimping machine (not shown). As a result, the tube 24, the restraining member 28, the sleeve 26, and the filler 60 are fixed to the sealing member 30 at one end of the actuator body 22 in the axial direction X. In other words, in this embodiment, the filler 60 is crimped together with the tube 24, the restraining member 28, and the sleeve 26, thereby filling the gap between the pair of tubes 24 and the sleeve 26.

[0062] Next, on the other side of the tube 24 , sleeve 26 , and restraint member 28 in the axial direction X, the restraint member 28 is inserted into the insertion portion 42H of the sealing member 31 .

[0063] Next, while being careful not to remove the restraint member 28 from the insertion portion 42H of the sealing member 31, the pair of insertion portions 50 of the sealing member 31 are inserted into the other of the pair of tubes 24 in the axial direction X.

[0064] Next, the sleeve 26 is hung up to the locking portion 58 of the tube 24 and the sealing member 31 to cover the outer surface of the restraining member 28, and the locking ring 34 is attached from the radial outside of the sleeve 26 at the position of the locking portion 58, thereby locking the sleeve 26 to the locking portion 58.

[0065] Next, the sleeve 26 is folded back up to the insertion portion 50 of the sealing member 31 so that the locking ring 34 is on the inside, and the crimping member 36 is arranged from the radial outside of the sleeve 26 to span the insertion portion 50 and the locking portion 58, and is then crimped using a crimping machine (not shown). As a result, the tube 24, the restraining member 28, and the sleeve 26 are fixed to the sealing member 31 at the other end of the actuator body 22 in the axial direction X.

[0066] By following the above procedure, one end and the other end of the tube 24 are sealed with the sealing member 30 and the sealing member 31, and the fluid pressure actuator 20 is assembled.

[0067] Next, the operation of the fluid pressure actuator 20 in the present disclosure will be described.

[0068] <Operation of fluid pressure actuator 20> As shown in Figure 12, the fluid pressure actuator 20 is used with the sealing member 30 on one end fixed to a robot hand (not shown) or the like, and the sealing member 31 on the other end being a free end.

[0069] First, with the second sealing member 30B airtight, compressed air is introduced through the connection hole H of the first sealing member 30A, increasing the pressure inside the tube 24 connected to the first sealing member 30A. The tube 24 connected to the first sealing member 30A elastically deforms and expands due to the increased internal pressure, causing the sleeve 26 to perform pantograph deformation so that the angle θ increases, and a force acts in a direction that shortens the length of the actuator main body 22. At this time, the shortening of the actuator main body 22 is restricted by the restraining member 28, which is disposed at the opposing portion where the pair of tubes 24 are aligned. As a result, the outer peripheral wall of the actuator main body 22 on the side where the first sealing member 30A is disposed shortens as viewed from the axial direction X. This causes the restraining member 28 to flex and deform, and the entire actuator main body 22 bends toward the left side of the drawing, as indicated by the two-dot chain line in FIG. 12 .

[0070] Similarly, when compressed air is introduced through the connection hole H of the second sealing member 30B with the first sealing member 30A released from its airtight state, the outer peripheral wall of the actuator body 22 on the side where the second sealing member 30B is disposed shortens as viewed from the axial direction X. This causes the restraint member 28 to flex and deform, and the entire actuator body 22 bends toward the right side of the drawing, as shown by the two-dot chain line in FIG.

[0071] In the present disclosure, the restraint member 28 has a length in the width direction Y, and therefore is less likely to bend in any direction other than the thickness direction, i.e., the alignment direction Z that intersects with the axial direction X of the sealing members 30 and 31.

[0072] In this way, in the fluid pressure actuator 20 of this 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 toward the sealing member 30 to which the compressed air is supplied. In other words, by supplying compressed air to either sealing member 30, the fluid pressure actuator 20 of this embodiment can be bent toward both sides in the arrangement direction Z.

[0073] 13 , when the axial cross section of the insertion section 50 of the assembled fluid pressure actuator 20 is viewed, the pair of fillers 60 are arranged in contact with the sleeve 26 and the pair of tubes 24, respectively. In other words, the pair of fillers 60 are pressed by the crimping member 36 via the sleeve 26, and also come into contact with the pair of insertion sections 50 via the tubes 24, thereby pressing the tubes 24 against the respective insertion sections 50.

[0074] Next, the actions and effects of the fluid pressure actuator 20 according to the present disclosure will be described.

[0075] <Operations and Effects> When assembled by crimping with the crimping member 36, the fluid pressure actuator 20 of this embodiment is provided with a filler 60 that is disposed in the recessed space 70 on the outer periphery of the pair of insertion portions 50 and that comes into contact with the pair of tubes 24 and the sleeve 26 to fill the gap. As a result, the tubes 24 are pressed against the insertion portions 50 by the crimping member 36 via the sealing member 30. Therefore, according to the fluid pressure actuator 20 of this embodiment, when fluid is supplied inside the tubes 24, the fluid is less likely to leak between the tubes 24 and the insertion portions 50.

[0076] Furthermore, in the fluid pressure actuator 20 of this embodiment, the length of the filler 60 in the axial direction X is set to a length that covers the length from one end to the other end of the pair of insertion sections 50. This makes it possible to obtain a filler 60 that presses the pair of insertion sections 50 over the entire length of the axial direction X, compared to when the length of the filler 60 in the axial direction X is shorter than the pair of insertion sections 50.

[0077] Furthermore, in the fluid pressure actuator 20 of this embodiment, the shape of the contact portion follows the shape of the insertion portion 50, so the tube 24 is pressed against the filler 60 and thereby comes into close contact with the insertion portion 50. Therefore, when a fluid is supplied inside the tube 24, the fluid is less likely to leak out from between the tube 24 and the sealing member 30, compared to when the shape of the contact portion does not follow the shape of the insertion portion 50.

[0078] Furthermore, the manufacturing method of the fluid pressure actuator 20 according to this embodiment includes the steps of placing a filler 60 in the recessed space 70 on the outer periphery of the pair of insertion portions 50 across the opposing portions as viewed from the axial direction X, and the steps of filling the gap between the pair of tubes 24 and the sleeve 26 with the filler 60 while fixing the pair of tubes 24 to the pair of insertion portions 50. Therefore, according to the manufacturing method of the fluid pressure actuator 20 according to this embodiment, it is possible to obtain a fluid pressure actuator 20 in which fluid is less likely to leak out from between the tubes 24 and the insertion portions 50 when fluid is supplied inside the tubes 24.

[0079] [First Modification] In the above description, the shape of the filler 60 conforms to the shape of the insertion portion 50 before it is assembled by crimping with the crimping member 36, but the technology of the present disclosure is not limited to this. For example, the filler 60 may not conform to the shape of the insertion portion 50 before it is crimped with the crimping member 36, but may be deformed to conform to the shape of the insertion portion 50 by being crimped together with the tube 24 by the crimping member 36. In other words, the filler 60 may be deformed to conform to the shape of the insertion portion 50 by the pressure of the crimping member 36 from the outside of the sleeve 26. In this case, the filler 60 may be a member that undergoes plastic deformation when crimped, or may be a member that undergoes elastic deformation when crimped.

[0080] Furthermore, in the fluid pressure actuator 20 of this modification, the filler is deformed to conform to the shape of the insertion section pair when the crimping member fixes the tube pair to the insertion section pair, so the tube is pressed by the filler to make tight contact with the insertion section. Therefore, when fluid is supplied inside the tubes, the fluid is less likely to leak between the tubes and the sealing member than when the filler does not deform before or after the crimping member fixes the tube pair to the insertion section pair.

[0081] [Second Modification] In the above description, the length of the filler 60 in the axial direction X is the length of the pair of insertion sections 50 in the axial direction X, but the technology of the present disclosure is not limited to this. The length of the filler 60 is not limited as long as it can come into contact with the sleeve 26 and the pair of tubes 24 and press the pair of tubes 24 when crimped by the crimping member 36.

[0082] In the above description, the inner contact portion 62 of the filler 60 that comes into contact with the insertion portion 50 via the tube 24 conforms to the shape of the insertion portion 50, but the technology of the present disclosure is not limited to this. The shape of the inner contact portion 62 is not particularly limited as long as it can come into contact with the sleeve 26 and the pair of tubes 24 and press against the pair of tubes 24 when the filler 60 is crimped by the crimping member 36. For example, the shape of the inner contact portion 62 may be linear when viewed from the axial direction X, or may bulge toward the pair of insertion portions 50.

[0083] In the above description, the outer contact portion 64 of the filler 60 that comes into contact with the insertion portion 50 via the tube 24 conforms to the inner shape of the crimping member 36, but the technology of the present disclosure is not limited to this. The shape of the outer contact portion 64 is not particularly limited as long as it can come into contact with the sleeve 26 and the pair of tubes 24 and press the pair of tubes 24 when the filler 60 is crimped by the crimping member 36. For example, the shape of the outer contact portion 64 may be linear when viewed from the axial direction X, or may be recessed radially inward.

[0084] In these modified examples, if they have the same configuration as this embodiment, the same functions and effects as this embodiment can be obtained.

[0085] The above describes an embodiment of the present disclosure with reference to the accompanying drawings. However, it is clear that a person with ordinary knowledge in the field of technology to which the present disclosure pertains can conceive of various modifications or applications within the scope of the technical ideas set forth in the claims, and it is understood that these also naturally fall within the technical scope of the present disclosure.

[0086] The disclosure of Japanese Patent Application No. 2023-207095, filed on December 7, 2023, is incorporated herein by reference in its entirety. All documents, patent applications, and technical standards described herein are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard was specifically and individually indicated to be incorporated by reference.

Claims

1. A fluid pressure actuator comprising: a tube pair having a pair of tubes arranged in parallel and which expand and contract due to fluid pressure; a sleeve covering the outer peripheral surfaces of the pair of tubes and expanding the tubes radially while restricting axial extension as the tubes expand; a sealing member formed with a pair of insertion sections having insertion sections into which axial ends of the tubes of the pair of tubes are respectively inserted, and sealing the ends of each of the tubes; a restraining member provided from one end side to the other end side of the pair of tubes in the axial direction, and sandwiched between opposing portions where the tubes face each other; a crimping member fixing the pair of tubes to the pair of insertion sections from the outside of the sleeve; and a filler material positioned in a recessed space on the outer periphery of the pair of insertion sections, straddling the opposing portions when viewed in the axial direction, and contacting the pair of tubes and the sleeve to fill any gaps.

2. The fluid pressure actuator according to claim 1, wherein the filler has a length sufficient to cover the pair of insertion portions from one end to the other end in the axial direction.

3. The fluid pressure actuator according to claim 2, wherein a contact portion of said filler that comes into contact with said insertion portion via said tube conforms to a shape of said insertion portion.

4. The fluid pressure actuator according to claim 2, wherein the filler is deformed to conform to the shape of the pair of insertion portions when the crimping member presses the sleeve from the outside.

5. A method for manufacturing a fluid pressure actuator, comprising the steps of: inserting a tube pair having a pair of tubes arranged in parallel and expanding and contracting due to fluid pressure into a pair of insertion parts, the pair of insertion parts having insertion parts into which axial ends of the tubes of a sealing member that seals the ends of the pair of tubes are inserted; providing a restraining member at opposing portions where the tubes face each other, from one end side to the other end side of the pair of tubes in the axial direction; placing a filler material in a recessed space on the outer periphery of the pair of insertion parts, straddling the opposing portions when viewed from the axial direction; covering the outer periphery of the pair of tubes with a sleeve which is an elastic structure woven with fiber cords oriented in a predetermined direction; and filling a gap between the pair of tubes and the sleeve with the filler material while fixing the pair of tubes to the pair of insertion parts using a crimping member from the outside of the sleeve.

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