JP3941064B2 - Fluid pressure cylinder and manufacturing method thereof - Google Patents

Description

  The present invention relates to a fluid pressure cylinder that displaces a piston along the axial direction of the cylinder with a pressure fluid, and a manufacturing method thereof.

  Conventionally, fluid pressure cylinders have been used as driving means for conveying and positioning workpieces and driving various industrial machines. In the fluid pressure cylinder, the piston provided inside the cylinder tube is displaced along the axial direction by the pressure fluid supplied from the fluid supply port, and the workpiece is moved through a piston rod connected to one end of the piston. Carrying, positioning, etc.

  In general, such a hydraulic cylinder has a head cover and a rod cover connected to the end of an open cylindrical cylinder tube, respectively, and the cylinder tube is closed by the head cover and the rod cover. The air-tightness or liquid-tightness is maintained (for example, see Patent Document 1).

  At this time, since the head cover and the rod cover are connected so as to protrude from both ends of the cylinder tube along the axial direction, the length of the entire fluid pressure cylinder along the axial direction increases. There's a problem.

  Therefore, there is a demand for further miniaturization of the fluid pressure cylinder because of the space for installing the fluid pressure cylinder. In order to meet such demands, the head cover and / or rod cover is provided inside the cylinder tube, and the dimensions along the axial direction can be shortened without protruding the head cover and rod cover from the end of the cylinder tube. A fluid pressure cylinder is employed.

  In this fluid pressure cylinder, a head cover provided on the piston head side is inserted into the inside of the cylinder tube, and an outer peripheral portion thereof is fitted into an annular groove formed along an inner peripheral surface of the end of the cylinder tube. It is attached to the cylinder tube integrally. In addition, after a rod cover provided on the piston rod side is inserted into the cylinder tube, a retaining ring having a resilient force in the radially outward direction is inserted into an annular groove formed on the opening side of the cylinder tube. It is a structure that is mounted in a state in which the displacement along the axial direction of the rod cover is restricted by the retaining ring (see, for example, Patent Document 2).

JP-A-10-196609 Japanese Patent Laid-Open No. 10-299717

  By the way, in such a conventional technique according to Patent Document 2, an annular groove for fitting the head cover into the cylinder tube is formed at a position closer to the center of the cylinder tube by a predetermined length from the end surface of the cylinder tube. . That is, in order to engage the outer peripheral portion of the head cover with the annular groove having a substantially concave cross section, the inner circumference of the cylinder tube having a diameter smaller than the inner circumference diameter of the annular groove is formed between the annular groove and the end surface of the cylinder tube. It is necessary that the surface is formed.

  In this case, in order to form an annular groove for fitting the head cover, it is necessary to make the length along the axial direction of the cylinder tube longer by the width dimension of the annular tube, and accordingly the fluid pressure There is a problem that the length of the cylinder in the axial direction increases.

  Further, when the head cover is fitted into the annular groove, the portion where the head cover is attached is closer to the center of the cylinder tube than the end surface of the cylinder tube, that is, from the end surface of the cylinder tube. Since the position is recessed by a predetermined length, there is a slight difference between the end surface of the cylinder tube and the end surface of the head cover. As a result, there is a concern that dust or the like accumulates in the recess formed by the head cover.

  The present invention has been made in consideration of the above-mentioned various problems and the like, and while shortening the length along the axial direction of the cylinder tube constituting the cylinder, the one surface of the cylinder tube is substantially planar. It is an object of the present invention to provide a fluid pressure cylinder that can be closed and a manufacturing method thereof.

To achieve the above object, the present invention provides a fluid pressure cylinder in which a piston is displaced in the cylinder chamber under the action of a pressure fluid supplied to the cylinder chamber via a pressure fluid inlet / outlet port.
A cylinder tube having a cylinder chamber penetrating in the axial direction, and an opening formed in said end of the cylinder chamber,
Wherein it is found on the end of the cylinder tube, and a protrusion protruding in the axial direction with respect to said end with facing the opening,
A small-diameter portion having a diameter smaller than the inner peripheral diameter of the opening, and a large-diameter portion having a diameter larger than that of the small-diameter portion and formed to have substantially the same diameter as the inner peripheral diameter of the opening. A cover member that is inserted into the block and closes,
A space formed between the opening and the outer peripheral surface of the small diameter portion;
Disposed in the space comprising an outer peripheral side of the small diameter portion, and the seal member ing an elastic material,
With
The protruding portion is inserted into the opening so that the large diameter portion is on the cylinder chamber side, and when the protruding portion is plastically deformed, the flesh of the protruding portion is plastically flowed into the space. The cover member is fitted and fixed to the opening of the cylinder tube while crushing the seal member, and the end of the cylinder tube is closed so as to be substantially flush with one surface of the cover member. It is characterized by that.

According to the present invention, the cover member is inserted into the opening formed at the end of the cylinder tube, the protruding portion of the cylinder tube is plastically deformed, and the cover member is opened by the meat of the protruding portion that plastically flows. The seal member is disposed in a space between the opening and the small diameter portion of the cover member . The flesh of the projecting portion is plastically flowed into the space, and flows into the space between the cover member and the opening while crushing the seal member mounted on the small diameter portion. In other words, since the seal member is made of an elastic material, the seal member is deformed by an amount corresponding to the amount of meat flowing into the space.

Therefore, even when the shape (volume) of the projecting portion of the cylinder tube and / or the space (volume) between the small diameter portion and the opening of the cover member varies, the seal member is deformed to deform the seal member. It becomes possible to adjust the variation in the shape (volume) of the protrusion and / or space. Therefore, even when the variation occurs, the one surface of the cylinder tube and the one surface of the cover member fitted to the opening can be closed as substantially the same plane under the adjusting action by the seal member, Setting of the shape (dimension management) of the protrusion between the cylinder tube and / or the space between the cover member and the opening is facilitated.

As a result, the end face of the fluid pressure cylinder to which the cover member is fitted can be closed as a substantially flat shape without any post-processing, so that the manufacturing process of the fluid pressure cylinder can be shortened. The mounting property of the fluid pressure cylinder to the wall surface can be improved.

Further, even when a cover member is provided inside the cylinder tube, it is not necessary to extend the cylinder tube along its axial direction, and the length along the axial direction of the cylinder tube can be shortened. The size of the fluid pressure cylinder can be reduced.

Still further, the present invention relates to a method for manufacturing a hydraulic cylinder in which a piston is provided so as to be displaceable along a cylinder chamber of a cylinder tube.
The opening formed at the end of the cylinder tube has a small diameter portion that is smaller than the inner peripheral diameter of the opening, and a diameter that is larger than the inner diameter of the small diameter portion and substantially the same diameter as the inner peripheral diameter of the opening. And a step of inserting a cover member fitted with a sealing member made of an elastic material into the small diameter portion ,
Faces to the opening, the plastically deformed protruding portion that protrudes to the end of the cylinder tube, the wall of the protrusion which is the plastic flow, the space between the small diameter portion of the opening and the cover member By pushing in, the cover member fitted with the seal member is fitted into the cylinder tube while crushing the seal member, and one surface of the cylinder tube is substantially flush with the one surface of the cover member. A blockage step;
It is characterized by having.

According to the present invention, after inserting the cover member into the opening formed in the end portion of the cylinder tube, the protruding portion of the cylinder tube is plastically deformed, and the flesh of the protruding portion that has plastic flow is attached to the cover member. The crushing seal member is crushed and flows into the space between the cover member and the opening. In other words, since the seal member is formed of an elastic material, the seal member is deformed by an amount corresponding to the amount of meat flowing in between the cover member and the opening.

Therefore, even when there is variation in the shape (volume) of the protruding portion of the cylinder tube and / or the space shape (volume) between the cover member and the opening, the pressing action of the plastically deformed meat of the protruding portion Variations in the shape (volume) of the protrusion and / or space are adjusted by the amount of deformation of the seal member that deforms downward. Therefore, even when the variation occurs, the one surface of the cylinder tube and the one surface of the cover member fitted to the opening can be closed as substantially the same plane under the adjusting action by the seal member, Setting of the shape (dimension management) of the protrusion between the cylinder tube and / or the space between the cover member and the opening is facilitated.

As a result, the end face of the fluid pressure cylinder to which the cover member is fitted can be closed as a substantially flat shape without post-processing, and therefore the manufacturing process of the fluid pressure cylinder can be shortened. At the same time, it is possible to improve the mountability of the fluid pressure cylinder to the wall surface.

Further, when a cover member is provided inside the cylinder tube, it is not necessary to extend the length along the axial direction of the cylinder tube, and the length along the axial direction of the cylinder tube can be shortened. The size of the fluid pressure cylinder can be reduced.

Further, the cover member has a small diameter portion formed by reducing the diameter from the inner peripheral diameter of the opening,
A large diameter portion formed to have substantially the same diameter as the inner peripheral diameter of the opening;
With
The seal member may be mounted on the outer peripheral surface of the small diameter portion in advance.

  According to the present invention, the following effects can be obtained.

  That is, a sealing member is interposed between the end of the cylinder tube and the cover member, and the projecting portion of the cylinder tube is plastically deformed with the cover member inserted into the opening of the cylinder tube. The cover member is fitted into the opening of the cylinder tube by the flesh of the protruding portion that has flowed, and one surface of the cylinder tube is made substantially planar, and one surface of the cover member and one surface of the cylinder tube are made substantially coplanar. Blocked.

  Therefore, even when the cover member is provided inside the cylinder tube, the cylinder tube can be shortened along the axial direction, and the hydraulic cylinder can be downsized.

  Further, when the cover member is fitted into the opening of the cylinder tube, the flesh of the protruding portion that plastically flows into the space between the cover member and the opening causes the seal member attached to the cover member to flow. It is deformed while crushing according to the amount. Therefore, even when variations occur in the shape (volume) of the protruding portion of the cylinder tube and / or the space shape (volume) between the cover member and the opening, the variation is adjusted by the deformation amount of the seal member. The one surface of the cylinder tube and the one surface of the cover member fitted in the opening can be closed as substantially the same plane, and the protrusion and / or the cover member and the opening between the cylinder tube Space shape setting (dimension management) becomes easy.

  The preferred embodiment of the fluid pressure cylinder according to the present invention will be described in detail with reference to the accompanying drawings.

  In FIG. 1, reference numeral 10 indicates a fluid pressure cylinder according to an embodiment of the present invention.

  As shown in FIG. 1, the fluid pressure cylinder 10 (hereinafter simply referred to as cylinder 10) is a cylinder tube having first and second ports 12 and 14 through which pressure fluid (for example, compressed air) is supplied and discharged. 16, an end plate (cover member) 18 that closes one end of the cylinder tube 16, an end block 20 that closes the other end of the cylinder tube 16, and the inside of the cylinder tube 16 in the axial direction. It comprises a piston 22 that is displaceable along a piston rod 24 that is connected to the end of the piston 22.

  The cylinder tube 16 is formed in a cylindrical shape from a metal material, and the first port 12 is formed on the outer peripheral surface on one end side, and the outer peripheral surface on the other end side is spaced apart from the first port 12 by a predetermined distance. A second port 14 is formed. The first and second ports 12 and 14 communicate with a cylinder chamber 28 formed in the cylinder tube 16 via communication passages 26a and 26b, respectively.

  A mounting hole (opening) 30 having a diameter larger than the inner peripheral diameter of the cylinder chamber 28 is formed on one end of the cylinder tube 16, and the end plate 18 is inserted into the mounting hole 30. . The end plate 18 is engaged with an engagement step portion 32 formed at the boundary between the mounting hole 30 and the cylinder chamber 28, and the dimension A in the thickness direction of the end plate 18 is the engagement step of the mounting hole 30. It is formed so as to be approximately the same as dimension B (A≈B) from the portion 32 to one end face (one face) 68 of the cylinder tube 16 (see FIG. 3). That is, when the end plate 18 is inserted into the mounting hole 30, the end surface (one surface) 70 of the end plate 18 and the one end surface 68 of the cylinder tube 16 are formed to be substantially in the same plane.

  As shown in FIG. 2, the end plate 18 is formed in a disk shape, and has a large diameter portion 34 formed to have substantially the same diameter as the mounting hole 30 of the cylinder tube 16, and a diameter reduced from the large diameter portion 34. The small-diameter portion 36 is formed. When the end plate 18 is mounted in the mounting hole 30, the large diameter portion 34 is engaged with the engagement step portion 32, and the end surface of the small diameter portion 36 and the one end surface 68 of the cylinder tube 16 are substantially the same. It becomes a plane (see FIG. 3).

  An annular seal member 46 is mounted on the outer peripheral surface of the small diameter portion 36 between the outer peripheral surface and the side surface of the large diameter portion 34 substantially orthogonal to the outer peripheral surface. The seal member 46 is formed from an elastic material (for example, fluorine rubber, NBR) or the like so as to have a substantially circular cross section.

  As shown in FIG. 1, the end block 20 is inserted into the cylinder chamber 28 on the other end side of the cylinder tube 16 and is engaged with an annular groove on the inner peripheral surface of the cylinder chamber 28. It is locked by a letter-shaped locking member 48. Therefore, displacement of the end block 20 along the axial direction (arrow X1, X2 direction) is restricted by the locking member 48.

  Further, a through hole 50 penetrating along the axial direction is formed in the central portion of the end block 20, and the piston rod 24 is inserted into the through hole 50. An annular groove 51 is formed by expanding the diameter from the through hole 50, and a rod packing 52 is attached to the annular groove 51. When the rod packing 52 abuts on the outer peripheral surface of the piston rod 24, the inside of the cylinder chamber 28 is kept airtight.

  A piston packing 54 is mounted on the outer peripheral surface of the piston 22 provided inside the cylinder chamber 28 via an annular groove 53, and the cylinder packing 28 is connected to the cylinder chamber 28 a on the first port 12 side by the piston packing 54. It is divided into a cylinder chamber 28b on the 2 port 14 side (see FIG. 1).

  The fluid pressure cylinder 10 according to the embodiment of the present invention is basically configured as described above. Next, the operation and effects thereof will be described.

  First, a method for manufacturing the cylinder 10 in which the end plate 18 is integrally caulked with respect to the mounting hole 30 of the cylinder tube 16 using an unillustrated caulking jig will be described. It should be noted that an annular projecting portion that projects from the one end surface 68 of the cylinder tube 16 before the end plate 18 is crimped by a predetermined length from the one end surface 68 of the cylinder tube 16 and has the same inner diameter as the mounting hole 30. 62 is formed (see FIG. 3).

  First, as shown in FIG. 2, the cylinder tube 16 is fixed with the mounting hole 30 opened upward, and the end plate 18 is inserted into the mounting hole 30 to insert the end plate 18. The end surface of the large-diameter portion 34 is engaged with the engagement step portion 32 (see FIG. 3). As a result, displacement along the axial direction of the end plate 18 toward the cylinder chamber 28 (in the direction of arrow E in FIG. 3) is regulated, and the end surface 70 of the end plate 18 and one end surface of the cylinder tube 16 are restricted. 68 is substantially the same plane.

  Next, a caulking jig (not shown) is driven to displace the caulking jig downward toward the cylinder tube 16.

  Next, the lower surface of the caulking jig and the projecting portion 62 of the cylinder tube 16 are brought into contact with each other under the displacement action of the caulking jig (in the direction of arrow E).

  As a result, a pressing force (pressing force) applied by a crimping jig (not shown) is locally applied to the projecting portion 62 via a contact portion between the lower surface of the caulking jig and the projecting portion 62. Then, the protruding portion 62 is plastically deformed under a pressing (pressing) action by the lower surface of the caulking jig.

  That is, the contact portion between the lower surface of the caulking jig and the upper surface of the protruding portion 62 circulates in the same direction as the rotation direction of the caulking jig under the rotating action of the caulking jig. And the pressing force from the caulking jig is locally applied to the protrusion 62.

  Next, the caulking jig is further displaced toward the cylinder tube 16 side (in the direction of arrow E), whereby the upper surface of the projecting portion 62 of the cylinder tube 16 is gradually moved along the circumferential direction. The flesh that has been plastically deformed by pressing toward the side is plastically deformed, and gradually flows into a space 74 formed between the mounting hole 30 and the outer peripheral surface of the small diameter portion 36 of the end plate 18.

  Then, the plastically deformed meat of the projecting portion 62 flows into the space 74 between the mounting hole 30 and the end plate 18, and the seal member 46 made of an elastic material is slightly crushed into the space 74 while being slightly crushed. It will be satisfied.

  Finally, the projecting portion 62 pressed by the lower surface of the caulking jig is further plastically deformed under the action of further displacement of the caulking jig (not shown) toward the cylinder tube 16, so that the inside of the space 74 is As a result, the caulking jig is displaced to a position where the one end surface 68 of the cylinder tube 16 and the lower surface of the caulking jig are substantially flush with each other (see FIG. 5).

  As a result, as shown in FIGS. 4 and 5, the projecting portion 62 of the cylinder tube 16 is plastically deformed, and the cylinder tube flows due to the flesh flowing into the space 74 between the mounting hole 30 and the end plate 18. Overhang portions 76 projecting radially inward from the inner peripheral surface of the sixteen mounting holes 30 are formed. The overhanging portion 76 covers the large diameter portion 34 of the end plate 18, so that the end plate 18 is fixed inside the mounting hole 30. Therefore, the end plate 18 is not removed from the mounting hole 30.

  That is, the protrusion 62 formed so as to protrude from the one end surface 68 of the cylinder tube 16 is plastically deformed under the pressing action of the caulking jig, and all the meat of the plastically deformed protrusion 62 is attached to the mounting hole. The end surface 70 of the end plate 18 and the one end surface 68 of the cylinder tube 16 are formed in substantially the same plane.

  As a result, the end plate 18 is integrally crimped in a state where it is inserted into the mounting hole 30 of the cylinder tube 16, and one end of the cylinder tube 16 is closed by the end plate 18 and the seal member 46.

  When the end plate 18 is inserted into the mounting hole 30 of the cylinder tube 16, the volume of the space 74 formed between the inner peripheral surface of the mounting hole 30 and the outer peripheral surface of the end plate 18 is one of the cylinder tubes 16. It is formed so as to be approximately the same as or slightly smaller than the volume of the protrusion 62 formed on the end face 68. The space 74 formed between the plastically deformed protrusion 62 and the end plate 18 is set so that its cross-sectional area is slightly smaller than the cross-sectional area of the seal member 46. The protrusion 62 is slightly crushed and deformed.

  Next, the operation of the cylinder 10 in which the end plate 18 is integrally crimped to one end of the cylinder tube 16 as described above will be described.

  As shown in FIG. 1, by supplying a pressure fluid (for example, compressed air) from a pressure fluid supply source (not shown) to the first port 12, the pressure fluid flows into one cylinder chamber 28a via a communication passage 26a. The piston 22 is introduced into the inside and is displaced toward the other cylinder chamber 28b (in the direction of arrow X1 in FIG. 1) under the pressing action of the pressure fluid. At that time, the second port 14 is open to the atmosphere.

  On the other hand, by switching the supply of pressure fluid from the first port 12 to the second port 14 under the switching action of a switching valve (not shown), the pressure fluid is supplied to the other cylinder chamber 28b through the communication passage 26b. Then, the piston 22 is displaced in the opposite direction (in the direction of arrow X2 in FIG. 1) under the pressing action by the pressure fluid and returns to the initial position. In this case, the first port 12 is open to the atmosphere. In this way, the piston 22 housed inside the cylinder chamber 28 of the cylinder tube 16 can be reciprocated along the axial direction (arrow X1, X2 direction).

  As described above, in the present embodiment, the disc-shaped end plate 18 is inserted into the mounting hole 30 formed on the one end side of the cylinder tube 16, and the cylinder tube is subjected to a pressing action by a crimping jig (not shown). The projecting portion 62 formed on one end face 68 of the 16 is plastically deformed.

  Then, all the plastically deformed meat of the protruding portion 62 is caused to flow into the space 74 between the mounting hole 30 and the end plate 18, and the end plate 18 is crimped to the cylinder tube 16. Conventionally, the annular groove formed on the inner peripheral surface of the cylinder tube for mounting the head cover is not necessary.

  Accordingly, the length along the axial direction of the cylinder tube that has been extended to form the annular groove can be shortened, and the one end surface 68 of the cylinder tube 16 and the end surface 70 of the end plate 18 are substantially omitted. By using the same plane, there is no useless space between the end plate 18 for closing the cylinder tube 16 and the end surface of the cylinder tube 16. Therefore, the length of the cylinder tube 16 along the axial direction can be shortened, and the size of the cylinder 10 can be reduced.

  Further, the end face 68 of the cylinder tube 16 and the end face 70 of the end plate 18 can be simply closed as substantially the same plane under a pressing action by a crimping jig (not shown). After the plate 18 is crimped, it is not necessary to separately finish the one end face 68 of the cylinder tube 16 and the end face 70 of the end plate 18, and the manufacturing process of the cylinder 10 can be shortened. It becomes.

  Further, when the end plate 18 is caulked into the mounting hole 30 of the cylinder tube 16, in order to close the one end surface 68 of the cylinder tube 16 and the end surface 70 of the end plate 18 as substantially the same plane, The volume of the protrusion 62 provided on the tube 16 is substantially the same as the volume of the space 74 between the mounting hole 30 and the end plate 18 into which the plastically deformed meat of the protrusion 62 flows, or the protrusion 62. It is necessary to set each so that the volume of each becomes slightly larger.

  Even in such a case, by disposing the seal member 46 mounted on the outer peripheral surface of the end plate 18 inside the space 74, the flowed meat of the protruding portion 62 made of a metal material flows into the space 74. At this time, the seal member 46 made of an elastic material is crushed by the meat, so that the volume in the space 74 is suitably adjusted.

  Therefore, even when a slight variation occurs in the volume of the protrusion 62 with respect to the volume of the space 74, the deformation amount of the seal member 46 can be freely changed according to the volume of the meat of the protrusion 62 that always flows in. The volume ratio between the projecting portion 62 and the space 74 can be easily set, and the end face 70 of the end plate 18 and the one end face 68 of the cylinder tube 16 can be simply and reliably substantially planar to close the cylinder tube 16. .

  Furthermore, the sealing member 46 attached to the small diameter portion 36 of the end plate 18 is plastically deformed in the protruding portion 62 of the cylinder tube 16 when the end plate 18 is crimped into the mounting hole 30 of the cylinder tube 16. It is sandwiched between the outer peripheral surface of the end plate 18 by the meat and the overhanging portion 76 formed by the plastically deformed meat. Therefore, even when a slight gap is generated between the end plate 18 crimped to the cylinder tube 16 and the mounting hole 30, the sealing member 46 is suitable for airtightness inside the cylinder chamber 28 of the cylinder tube 16. Maintained.

1 is a longitudinal sectional view of a fluid pressure cylinder to which a fluid pressure cylinder and a manufacturing method thereof according to an embodiment of the present invention are applied. FIG. 2 is an exploded perspective view of a cylinder tube, an end plate, and a seal member before the end plate is crimped to the fluid pressure cylinder of FIG. 1. FIG. 5 is a partially omitted vertical cross-sectional explanatory view showing a state where an end plate is inserted into a cylinder tube mounting hole. The protruding portion of the cylinder tube in FIG. 3 is plastically deformed, and the flesh that has been plastically deformed and flowed is caused to flow into the space between the mounting hole and the end plate, so that one end surface of the cylinder tube and the end surface of the end plate are substantially the same. It is a partially-omitted longitudinal cross-sectional explanatory drawing which shows the state formed in the plane. FIG. 5 is a perspective view of a fluid pressure cylinder in a state where an end plate is crimped into the cylinder tube of FIG. 4.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Fluid pressure cylinder 16 ... Cylinder tube 18 ... End plate 20 ... End block 22 ... Piston 24 ... Piston rod 30 ... Mounting hole 34 ... Large diameter part 36 ... Small diameter part 46 ... Seal member 48 ... Locking member 62 ... Protrusion part 74 ... Space 76 ... Overhang

Claims (2)

In the fluid pressure cylinder in which the piston is displaced in the cylinder chamber under the action of the pressure fluid supplied to the cylinder chamber via the pressure fluid inlet / outlet port,
A cylinder tube having a cylinder chamber penetrating in the axial direction, and an opening formed in said end of the cylinder chamber,
Wherein it is found on the end of the cylinder tube, and a protrusion protruding in the axial direction with respect to said end with facing the opening,
A small-diameter portion having a diameter smaller than the inner peripheral diameter of the opening, and a large-diameter portion having a diameter larger than that of the small-diameter portion and formed to have substantially the same diameter as the inner peripheral diameter of the opening. A cover member that is inserted into the block and closes,
A space formed between the opening and the outer peripheral surface of the small diameter portion;
Disposed in the space comprising an outer peripheral side of the small diameter portion, and the seal member ing an elastic material,
With
The protruding portion is inserted into the opening so that the large diameter portion is on the cylinder chamber side, and when the protruding portion is plastically deformed, the flesh of the protruding portion is plastically flowed into the space. The cover member is fitted and fixed to the opening of the cylinder tube while crushing the seal member, and the end of the cylinder tube is closed so as to be substantially flush with one surface of the cover member. A fluid pressure cylinder characterized by that. In a manufacturing method of a fluid pressure cylinder in which a piston is provided to be displaceable along a cylinder chamber of a cylinder tube,
The opening formed at the end of the cylinder tube has a small diameter portion that is smaller than the inner peripheral diameter of the opening, and a diameter that is larger than the inner diameter of the small diameter portion and substantially the same diameter as the inner peripheral diameter of the opening. And a step of inserting a cover member fitted with a sealing member made of an elastic material into the small diameter portion ,
Faces to the opening, the plastically deformed protruding portion that protrudes to the end of the cylinder tube, the wall of the protrusion which is the plastic flow, the space between the small diameter portion of the opening and the cover member By pushing in, the cover member fitted with the seal member is fitted into the cylinder tube while crushing the seal member, and one surface of the cylinder tube is substantially flush with the one surface of the cover member. A blockage step;
A method of manufacturing a fluid pressure cylinder, comprising:

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