WO2011111488A1

WO2011111488A1 - Fluid pressure cylinder

Info

Publication number: WO2011111488A1
Application number: PCT/JP2011/053260
Authority: WO
Inventors: 貴彦原
Original assignee: カヤバ工業株式会社
Priority date: 2010-03-08
Filing date: 2011-02-16
Publication date: 2011-09-15
Also published as: JP2011185343A

Abstract

A piston is housed in a cylinder tube, which has a central axis and an inner circumferential surface facing the central axis. The piston is configured from a first piston component and a second piston component, which join in the central axis direction. A seal ring housing groove for holding a seal ring is positioned between the first piston component and the second piston component, thereby facilitating the attachment of the seal ring to the piston.

Description

Fluid pressure cylinder

The present invention relates to a fluid pressure cylinder used in hydraulic equipment, pneumatic equipment, etc. for construction machines and work machines.

The piston that is slidably mounted in the cylinder tube of the hydraulic cylinder, and that defines the oil chamber in the cylinder tube, is fitted with a seal ring that comes into sliding contact with the cylinder tube to prevent leakage of hydraulic oil from the oil chamber. Is done. In order to hold the seal ring, a ring-shaped accommodation groove continuous in the circumferential direction is formed on the outer periphery of the piston.

¡When mounting the seal ring to the piston, the diameter of the seal ring is expanded using a mounting jig and guided to the receiving groove along the outer periphery of the piston. The seal ring that reaches the periphery of the receiving groove is fitted into the receiving groove by reducing the diameter using a correction jig.

¡As described above, mounting the seal ring to the piston using a plurality of jigs increases the number of steps for assembling the piston.

JP62-016865U issued by the Japan Patent Office in 1987 proposes to divide the piston.

¡A metal ring is mounted on the outer periphery of the piston according to this conventional technology along with the seal ring. The metal ring functions to keep the shape of the seal ring by contacting the end face of the seal ring. The piston is divided into two piston components axially from the receiving groove of the metal ring. By attaching the metal ring when connecting the two piston components, the metal ring can be easily attached to the receiving groove formed between the two piston components.

Although the conventional technology facilitates the mounting of the metal ring to the piston, the mounting of the seal ring to the piston still requires expansion and contraction of the seal ring.

The object of the present invention is therefore to facilitate the mounting of the seal ring to the piston.

To achieve the above object, a fluid pressure cylinder according to the present invention includes a cylinder tube having a central axis and an inner peripheral surface facing the central axis, a cylinder tube and a seal ring receiving groove in the circumferential direction on the outer periphery. And a seal ring held in the seal ring receiving groove and in sliding contact with the inner peripheral surface of the cylinder tube. The piston is composed of a first piston component and a second piston component that are coupled in the central axial direction. The seal ring receiving groove is disposed between the first piston component and the second piston component.

DETAILED DESCRIPTION Details and other features and advantages of the present invention are described in the following description of the specification and shown in the accompanying drawings.

FIG. 1 is a longitudinal sectional view including a partial side surface of a hydraulic cylinder according to a first embodiment of the present invention. FIG. 2 is an enlarged longitudinal sectional view of a main part of the fluid pressure cylinder. FIG. 3 is a composite view of a side view and a longitudinal sectional view of the piston according to the first embodiment of the present invention. FIG. 4 is a plan view of the piston. FIG. 5 is a composite view of a side view and a longitudinal sectional view of a piston according to a second embodiment of the present invention. FIG. 6 is a plan view of a piston according to a second embodiment of the present invention. FIG. 7 is a composite view of a side view and a longitudinal sectional view of a piston of a piston according to a third embodiment of the present invention. FIG. 8 is a plan view of a piston according to a third embodiment of the present invention. FIG. 9 is a composite view of a side view and a longitudinal sectional view of a piston of a piston according to a fourth embodiment of the present invention. FIG. 10 is a plan view of a piston according to a fourth embodiment of the present invention.

Fig. Of the drawing. 1, a hydraulic cylinder 1 using oil as a working fluid includes a cylinder tube 2, a piston 4 slidably housed inside the cylinder tube 2, and a piston 4 coupled to the piston 4. A piston rod 3 projecting in the direction. The piston rod 3 protrudes outside the cylinder tube 2 through a cylinder head 7 provided at the opening end of the cylinder tube 2 so as to freely slide.

The hydraulic cylinder 1 is used as an actuator for construction machines and work machines, for example. It is also possible to use a water-soluble alternative liquid or gas instead of oil as the working fluid.

The cylinder tube 2, the piston rod 3, the piston 4, and the cylinder head 7 are arranged coaxially with respect to the central axis O of the cylinder tube 2 and the piston 4.

The inside of the cylinder tube 2 is defined by the piston 4 into an oil chamber 5 on the piston rod 3 side and an oil chamber 6 on the opposite side.

Oil chambers

5 and 6 are each connected to a hydraulic pressure source via a pipe. The hydraulic cylinder 1 is contracted according to the supply of hydraulic oil from the hydraulic source to the oil chamber 5, and is extended according to the supply of hydraulic oil from the hydraulic source to the oil chamber 6.

FIG. 2, on the outer periphery of the piston 4, the contamination seal ring 16, the bearing ring 15, the backup ring 13, the seal ring 10, the backup ring 14, and the contamination seal ring 17 are directed from the oil chamber 5 to the oil chamber 6. Is installed.

The piston 4 includes a ring-shaped first piston component 40 and a second piston component 60 coupled in the axial direction. On the inner periphery of the first piston component 40, a female screw portion 54 that is screwed into the male screw portion 24 of the piston rod 3 is formed. On the inner periphery of the second piston component 60, a female screw portion 72 that is screwed into the male screw portion 24 of the piston rod 3 is formed closer to the tip of the piston rod 3 than the first piston component 40.

A seal ring receiving groove 39 is formed in the circumferential direction between the first piston component 40 and the second piston component 60. The seal ring 10 and the O-ring 11 are disposed in the seal ring receiving groove 39. *

FIG. 3, due to the seal ring receiving groove 39, a circumferential cutout is formed on the outer periphery of the end of the first piston component 40 facing the second piston component 60. The notch is composed of an end face 41 that recedes in the axial direction that constitutes one wall surface of the seal ring accommodating groove 39, and an outer peripheral face 42 that recedes in the radial direction that constitutes the bottom face of the seal ring accommodating groove 39. The end surface 41 receding in the axial direction is formed as an annular plane orthogonal to the central axis O of the piston 4, and the outer peripheral surface 42 receding in the radial direction is formed as a cylindrical surface centered on the central axis O. The second piston component 60 is formed with an end surface 61 constituting the other wall surface of the seal ring receiving groove 39 so as to be opposed to the end surface 41 which is retreated in the axial direction. The end surface 61 is formed as an annular flat surface that is orthogonal to the central axis O of the piston 4.

It is also possible to form a notch for the seal ring housing groove 39 in the second piston component 60 and form an end surface constituting the other wall surface of the seal ring housing groove 39 in the first piston component 40. is there.

The first piston component 40 includes an annular end surface 55 that is orthogonal to the central axis O inside the end surface 41 that is retracted in the axial direction. The second piston component 60 is provided with an end surface 71 that is retracted in the axial direction inside the end surface 61. The end surface 71 receding in the axial direction forms an annular plane orthogonal to the central axis O. A cylindrical inner peripheral surface 62 parallel to the central axis O is formed between the end surface 61 and the end surface 71 receding in the axial direction. By fitting the outer peripheral surface 42 retracted in the radial direction of the first piston component 40 to the inner peripheral surface 62, coaxiality between the first piston component 40 and the second piston component 60 is ensured.

Again FIG. Referring to FIG. 2, the O-ring 11 has a circular cross section, and is formed in a ring shape without a break by an elastic material such as rubber. The O-ring 11 is fitted in the seal ring receiving groove 39 so as to be located inside the seal ring 10, that is, near the center axis O. The seal ring 10 is disposed so as to overlap the outside of the O-ring 11 in the seal-ring receiving groove 39, and the inner peripheral surface abuts on the O-ring 11. The seal ring 10 is urged outward in the radial direction by an O-ring 11 made of an elastic material.

The seal ring 10 has a portion that fits in the seal ring receiving groove 39 and a portion that protrudes outward in the radial direction from the seal ring receiving groove 39 toward the inner peripheral surface 25 of the cylinder tube 2.

The seal ring 10 urged outward in the radial direction by the O-ring 11 is in sliding contact with the inner peripheral surface 25 of the cylinder tube 2 over the entire outer peripheral surface. As a result, the seal ring 10 blocks leakage of hydraulic oil between the oil chamber 5 on the piston rod 3 side and the oil chamber 6 on the opposite side.

The seal ring 10 has a rectangular cross section and is formed into a seamless ring shape with a synthetic resin material such as polytetrafluoroethylene (PTFE).

A backup ring receiving groove 37 is formed on the outer periphery of the first piston component 40 outside the seal ring receiving groove 39 in the axial direction. The backup ring receiving groove 37 is formed so as to widen the opening of the seal ring receiving groove 39 and is continuous with the seal ring receiving groove 39 in the axial direction. The backup ring 13 is housed in the backup ring receiving groove 37. The backup ring 13 has a rectangular cross section, and is formed into a continuous ring shape by a resin material having a hardness equal to or higher than that of the seal ring 10. The backup ring 13 is accommodated in the backup ring receiving groove 37 such that one side surface is in contact with the wall surface of the backup ring receiving groove 37 and the other side surface is in contact with the seal ring 10.

A backup ring receiving groove 38 is formed on the outer periphery of the second piston component 60 at a position facing the backup ring receiving groove 37. In a state where the first piston component 40 and the second piston component 60 are integrated, the backup ring receiving groove 38 is located on the opposite side of the backup ring receiving groove 37 with the seal ring receiving groove 39 interposed therebetween, and the seal ring receiving It is continuous with the groove 39 in the axial direction.

The backup ring 14 having the same specifications as the backup ring 13 is housed in the backup ring receiving groove 38. The backup ring 14 is accommodated in the backup ring receiving groove 38 such that one side surface is in contact with the wall surface of the backup ring receiving groove 38 and the other side surface is in contact with the seal ring 10. As described above, the backup rings 13 and 14 are in contact with both end faces in the axial direction of the seal ring 10, so that the seal ring 10 is protected against the load that the seal ring 10 receives from the sliding contact with the inner peripheral surface 25 of the cylinder tube 2. 10 is supported and the shape of the seal ring 10 is maintained.

The housing groove 36 is formed on the outer periphery of the first piston component 40 in parallel with the backup ring housing groove 37 at a slight distance from the backup ring housing groove 37 in the axial direction. The bearing ring 15 is received in the receiving groove 36.

The bearing ring 15 has a rectangular cross section, and is formed in a ring shape with no breaks by synthetic resin such as polyimide resin. The bearing ring 15 slidably supports the piston 4 with respect to the cylinder tube 2 by sliding the outer peripheral surface thereof to the inner peripheral surface 25 of the cylinder tube 2.

In this embodiment, the storage groove 36 and the backup ring storage groove 37 are formed with an interval in the axial direction, but the backup ring 13 and the bearing ring 15 may be arranged side by side in a single storage groove. Is possible. In this case, the backup ring 13 contacts both the bearing ring 15 and the seal ring 10.

The housing groove 34 is formed on the outer periphery of the first piston component 40 in parallel with the housing groove 36 at a slight distance from the housing groove 36 in the axial direction. The contamination seal ring 16 is accommodated in the accommodation groove 34. A receiving groove 35 is formed on the outer periphery of the second piston component 60 in parallel with the backup ring receiving groove 38 at a slight distance from the backup ring receiving groove 38 in the axial direction. The contamination seal ring 17 is received in the receiving groove 35.

The contamination seal rings 16 and 17 have a role of preventing contamination substances mixed in the hydraulic oil from entering the sliding contact portion of the seal ring 10 by sliding contact with the inner peripheral surface 25 of the cylinder tube 2.

The male thread portion 24 of the piston rod 3 is formed on the outer periphery of the tip of the piston rod 3. The piston rod 3 expands to the intermediate diameter portion 22 through the step 23 at the proximal end in the axial direction of the male screw portion 24, and further expands through the step 21.

The enlarged diameter part 52 which adjoins the internal thread part 54 via the end surface 53 in the inner periphery of the 1st piston component 40 is formed. The enlarged diameter portion 52 opens in the end surface 51 opposite to the annular end surface 55 of the first piston component 40.

By tightening the female threaded portion 54 of the first piston component 40 to the male threaded portion 24 of the piston rod 3, the end surface 51 of the first piston component 40 abuts on the step 21 of the piston rod 3, and the first piston component The end face 53 of 40 abuts on the step 23 of the piston rod 3. The end surface 51 abuts on the step 21 and the end surface 53 abuts on the step 23, whereby the axial positioning of the first piston component 40 relative to the piston rod 3 is performed.

However, it is also possible to fix the first piston component 40 to the piston rod 3 at an axial position where the end surface 51 does not contact the step 21 and the end surface 53 does not contact the step 23. In that case, the step 21 may be eliminated and the diameter of the piston rod 3 may be made equal to the intermediate diameter portion 22.

A receiving groove 56 is formed in the circumferential direction on the inner periphery of the first piston component 40. The O-ring 8 is fitted in the receiving groove 56. The O-ring 8 is made of an elastic material such as rubber and abuts against the intermediate diameter portion 22 of the piston rod 3 by an elastic restoring force. The O-ring 8 has a role of preventing leakage of hydraulic oil between the

oil chambers

5 and 6 via a threaded portion between the piston 4 and the piston rod 3.

The second piston component 60 is integrated with the first piston component 40 by screwing the female screw portion 72 to the male screw portion 24 of the piston rod 3 as described above. At this time, the retracted end surface 71 of the second piston component 60 is pressed against the annular end surface 55 of the first piston component 40, and the first piston component 40 and the second piston component are caused by the friction force generated between them. The relative rotation of 60 is restricted. This state is referred to as temporary fastening of the piston 4 to the piston rod 3.

The second piston component 60 has an end surface 73 facing the oil chamber 6 on the side opposite to the retracted end surface 71. Six axial screw holes 74 that pass through the second piston component 60 and reach the end surface 71 retracted from the end surface 73 are formed in the second piston component 60 at equal angular intervals in the circumferential direction. The set screw 9 is received in the screw hole 74 in a screwed state.

FIG. 4, a hexagonal hole 75 is formed in the head of the set screw 9. The set screw 9 is displaced in the axial direction while rotating in the screw hole 74 by a rotating operation of a hexagon wrench inserted into the screw hole 74 of the end face 73 and fitted in the hexagon hole 75.

FIG. As shown in FIG. 1, in the state where the first piston component 40 and the second piston component 60 are screwed to the piston rod 3, the set screw 9 is tightened by operating the hexagon wrench. The tip 19 is strongly pressed against the annular end surface 55 of the first piston component 40. As a result, a large frictional force is generated between the tip 19 of the set screw 9 and the annular end surface 55 with respect to the relative rotation of the first piston component 40 and the second piston component 60. The set screw 9 serves to lock the relative rotation between the first piston component 40 and the second piston component 60 by this frictional force. A state in which all the set screws 9 are tightened is referred to as main fastening of the piston 4 to the piston rod 3.

In this hydraulic cylinder 1, the set screw 9 is screwed into the screw hole 74 in advance through the opening portion of the end surface 71 that is retracted in the axial direction of the second piston component 60. However, it is also possible to form the screw hole 74 so that the set screw 9 can be attached to the screw hole 74 from the opening of the end surface 73 of the second piston component 60.

The piston 4 is assembled as follows, for example.

(1) The female screw portion 54 of the first piston component 40 is screwed into the male screw portion 24 of the piston rod 3.

(2) After mounting the backup ring 13 in the backup ring receiving groove 37 of the first piston component 40, the O-ring 11 is mounted on the outer peripheral surface 42 that has receded in the radial direction, and the seal ring 10 is mounted on the outer periphery of the O-ring 11. Installing.

(3) The backup ring 14 is mounted in the backup ring receiving groove 38 of the second piston component 60.

(4) The set screw 9 is screwed into the screw hole 74 from the opening portion of the screw hole 74 of the end face 71 retracted in the axial direction of the second piston component 60 and buried in the screw hole 74.

(5) The second piston component 60 is screwed into the piston rod 3 to temporarily fix the piston 4 to the piston rod 3. Next, the set screw 9 is rotated by inserting a hexagon wrench into the screw hole 74 from the opening on the end surface 71 side retracted in the axial direction of the second piston component 60, and the tip 19 of the set screw 9 is annular. Tighten until pressed against the end face 55. As a result, the piston 4 is finally fastened to the piston rod 3.

(6) The bearing ring 15 and the contamination seal ring 16 are mounted in the receiving groove 34 of the first piston component 40, and the contamination seal ring 17 is mounted in the receiving groove 35 of the second piston component 60.

The assembly order of the piston 4 is not limited to the above. For example, prior to assembly of the piston 4, the bearing ring 15 and the contamination seal ring 16 may be attached to the first piston component 40, and the contamination seal ring 17 may be attached to the second piston component 60. is there.

As described above, in the hydraulic cylinder 1, since the seal ring receiving groove 39 is formed between the first piston component 40 and the second piston component 60, the seal ring 10 is not enlarged or reduced in diameter. It can be easily attached to the seal ring receiving groove 39. Therefore, the seal ring 10 can be attached to the piston 4 without using a jig for expanding the diameter or a jig for reducing the diameter after the diameter expansion, and the assembly man-hour of the piston 4 can be reduced.

Further, the backup

ring receiving grooves

37 and 38 for receiving the backup rings 13 and 14 are formed on both sides in the axial direction of the seal ring receiving groove 39 so as to be continuous with the seal ring receiving groove 39 in the axial direction. The ring 13 can be easily mounted in the backup ring receiving groove 37 and the backup ring 14 can be easily mounted in the backup ring receiving groove 38.

Further, the hydraulic cylinder 1 fixes the first piston component 40 and the second piston component 60 to the piston rod 3 by a two-stage fastening process of temporary fastening and final fastening. Therefore, even if the first piston component 40 and the second piston component 60 are not fastened to the piston rod 3 with a large torque at the time of temporary fastening, the first piston component 40 and the second piston component 60 are connected to the piston by this fastening. It can be firmly integrated with the rod 3.

Fig. A second embodiment of the present invention will be described with reference to 5 and 6.

The piston 4 according to this embodiment corresponds to the first embodiment in which the set screw 9 is omitted.

The configuration of the first piston component 40 is the same as that of the first embodiment. The second piston component 60 is not formed with the screw hole 74 as in the first embodiment, but instead a pair of parallel operation surfaces for rotating the second piston component 60 in the vicinity of the end surface 73. 76 is formed.

When screwing the female threaded portion 72 of the second piston component 60 into the male threaded portion 24 of the piston rod 3, the second piston component 60 is rotated using a spanner fitted to the operation surface 76. By this operation, the second piston component 60 is fastened to the piston rod 3 with a large torque, and the end surface 71 retracted in the axial direction is pressed against the annular end surface 55 of the first piston component 40. Relative rotation of the first piston component 40 and the second piston component 60 after the coupling is prevented by the frictional resistance between the end surface 71 that is axially retracted and the annular end surface 55.

According to this embodiment, the piston 4 can be fastened to the piston rod 3 by a single operation.

FIG. A third embodiment of the present invention will be described with reference to FIGS.

The piston 4 according to this embodiment corresponds to the first embodiment in which the female thread portion 54, the O-ring 8 and the housing groove 56 of the first piston component 40 are omitted.

The configuration of the second piston component 60 is the same as that of the first embodiment. The internal thread surface 54 is not formed on the inner peripheral surface 57 of the first piston component 40, and the first piston component 40 is fitted to the outer periphery of the piston rod 3 with a slight gap.

At the time of temporary fastening, the female threaded portion 72 of the second piston component 60 is screwed into the male threaded portion 24 of the piston rod 3, and the end surface 71 retracted in the axial direction is pressed against the annular end surface 55 of the first piston component 40. . At this time, the outer peripheral surface 42 retracted in the radial direction of the first piston component 40 is fitted to the inner peripheral surface 62, so that the coaxiality between the first piston component 40 and the second piston component 60 is ensured. The

Further, in this fastening, as in the first embodiment, by tightening the set screw 9, the tip 19 of the set screw 9 is strongly pressed against the annular end face 55 of the first piston component 40, and the first screw The relative rotation between the first piston component 40 and the second piston component 60 is locked. Further, the end surface 53 of the first piston component 40 is pressed against the step 23 of the piston rod 3, and a metal seal is formed that seals between the first piston component 40 and the piston rod 3.

Also in this embodiment, the first piston component 40 and the second piston component can be separated from the temporary fastening and the main fastening as in the first embodiment without applying a large tightening torque during the temporary fastening. 60 can be firmly integrated with the piston rod 3.

In this embodiment, the end face 53 of the first piston component 40 and the step 23 of the piston rod 3 constitute a metal seal, so that the receiving groove 56 and the O-ring 8 of the first embodiment are omitted. ing. However, it is possible to reduce the pressing force of the end surface 53 of the first piston component 40 against the step 23 of the piston rod 3 by providing the same housing groove 56 and O-ring 8 as in the first embodiment.

FIG. A fourth embodiment of the present invention will be described with reference to FIGS.

This embodiment corresponds to the second embodiment in which the female thread portion 54 of the first piston component 40 is omitted. In other words, this corresponds to a configuration in which the set screw 9 and the female screw portion 54 are omitted from the first embodiment.

In this embodiment, as in the second embodiment, a pair of parallel operation surfaces 76 for rotating the second piston component 60 is formed in the vicinity of the end surface 73 of the second piston component 60. .

In assembling the piston 4, the first piston component 40 is fitted to the outer periphery of the male screw portion 24 of the piston rod 3, and the female screw portion 72 of the second piston component 60 is connected to the male screw portion 24 of the piston rod 3. The second piston component 60 is rotated using a spanner that is screwed and fitted to the operation surface 76. By this operation, the second piston component 60 is fastened to the piston rod 3 with a large torque, and the end surface 71 retracted in the axial direction of the second piston component 60 is pressed against the annular end surface 55 of the first piston component 40. . Relative rotation of the first piston component 40 and the second piston component 60 after the coupling is prevented by the frictional resistance between the end surface 71 that is axially retracted and the annular end surface 55.

Also in this embodiment, if the end face 53 of the first piston component 40 and the step 23 of the piston rod 3 can function as a metal seal, the O-ring 8 can be omitted.

Regarding the above explanation, the contents of Japanese Patent Application No. 2010-50300 in Japan, whose application date is March 8, 2010, are incorporated herein by reference.

Although the present invention has been described through several specific embodiments, the present invention is not limited to the above embodiments. Those skilled in the art can make various modifications or changes to these embodiments within the scope of the claims.

For example, in each of the above embodiments, the present invention is applied to the double-acting hydraulic cylinder 1 in which the two

oil chambers

5 and 6 are formed in the cylinder tube 2. The present invention can also be applied to a single-acting hydraulic cylinder in which one chamber on the piston rod 3 side or the other side of 4 is an oil chamber. In that case, the backup ring 13 can be provided only on the opposite side of the oil chamber with the seal ring 10 interposed therebetween without providing the backup ring 13 on both sides of the seal ring 10.

Also, when the hydraulic pressure supplied to the oil chamber is relatively low, the backup ring 13 itself may be eliminated.

The fluid pressure cylinder according to the present invention is useful for hydraulic equipment and pneumatic equipment for construction machines and work machines.

The exclusive properties or features encompassed by embodiments of the invention are claimed as follows.

Claims

A cylinder tube having a central axis and an inner peripheral surface facing the central axis;
A piston housed in a cylinder tube and having a circumferentially formed seal ring receiving groove on the outer periphery;
A seal ring held in the seal ring receiving groove and slidably contacting the inner peripheral surface of the cylinder tube;
With
A first piston component that couples the piston in the central axial direction and a second piston component;
A fluid pressure cylinder having a seal ring receiving groove disposed between a first piston component and a second piston component.
A circumferential notch that forms a seal ring groove in the coupled state of the first piston component and the second piston component is formed on one outer periphery of the opposite ends of the first piston component and the second piston component. The fluid pressure cylinder of claim 1.
The first piston component and the second piston component in the combined state further include a backup ring receiving groove that is continuous in the circumferential direction and faces the seal ring groove and is shallower than the seal ring groove. The fluid pressure cylinder of claim 2, further comprising a backup ring housed in contact with the seal ring.
A piston rod coupled to the piston and projecting axially from the cylinder tube, wherein the first piston component is screwed into the piston rod, and the second piston component is located on the distal end side of the piston rod with respect to the first piston component; The fluid pressure cylinder according to claim 1, wherein the fluid pressure cylinder is screwed to the piston rod.
A piston rod coupled to the piston and projecting axially from the cylinder tube, the first piston component being fitted to the outer periphery of the piston rod, and the second piston component being more of the piston rod than the first piston component; The fluid pressure cylinder according to claim 1, wherein the fluid pressure cylinder is screwed onto a piston rod at a distal end side.
The fluid pressure cylinder according to claim 5, wherein the second piston component has a pair of parallel operation surfaces for holding and rotating with a tool.
The fluid pressure cylinder according to claim 4, further comprising a set screw that is threadedly engaged with the second piston component, penetrates the second piston component, and has a tip abutting against the first piston component.
The fluid pressure cylinder according to claim 4, further comprising an O-ring interposed between the first piston component and the piston rod.
The fluid pressure cylinder according to claim 1, wherein the first piston component has an outer peripheral surface retracted in the radial direction, and the second piston component has an inner peripheral surface fitted to the outer peripheral surface retracted in the radial direction.