JP2020051458A - Cylinder device and method for manufacturing the same - Google Patents

Abstract

To provide a cylinder device that can improve reliability, and to provide a method for manufacturing the same.SOLUTION: A cylinder device includes: a piston rod 15 having one end connected to a piston and the other end extending to the outside of a cylinder 19; and a stopper 121 provided in a groove part 111 formed in the other end of the piston rod and having a diameter larger than an internal diameter of an insertion hole 34 of a cover part 31 that abuts on a side of one end of the cylinder 19 and is formed with the insertion hole 34 into which the piston rod 15 is inserted, whereby reliability can be improved.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a cylinder device and a method for manufacturing the same.

  There is a cylinder device having a cylinder in which a working fluid is sealed, a piston inserted into the cylinder, and a piston rod one end of which is connected to the piston and the other end of which extends to the outside of the cylinder (for example, Patent Document 1). 1). In such a cylinder device, a seal member that slides on the piston rod to prevent the working fluid from leaking out of the cylinder is provided.

JP 2013-133927 A

  It is desired to improve the reliability of the cylinder device.

  An object of the present invention is to provide a cylinder device capable of improving reliability and a method of manufacturing the same.

  In order to achieve the above object, a cylinder device according to the present invention is characterized in that a stopper provided in a groove formed on the other end side of a piston rod having one end connected to a piston and the other end extending to the outside of the cylinder has a piston. An insertion hole through which the rod is inserted is formed, and the diameter of the insertion hole is larger than the inner diameter of the insertion hole of the cover portion abutting on one end side of the cylinder.

  Further, in the method for manufacturing a cylinder device according to the present invention, the stopper provided in the groove formed on the other end of the piston rod having one end connected to the piston and the other end extending to the outside of the cylinder is fixed to the piston rod. A stopper fixing step of fixing the stopper to the piston rod by plastically deforming the stopper while constraining a part of a side surface connected to the opposite surface and the opposite surface facing the cover part of the stopper. did.

  According to the present invention, it is possible to improve reliability.

It is a sectional view showing the cylinder device of one embodiment concerning the present invention. It is a fragmentary sectional view of an important section showing a cylinder device of one embodiment concerning the present invention. It is the fragmentary front view which showed a part of stopper and piston rod before a stopper fixing process of a cylinder device of one embodiment concerning the present invention. It is a sectional view showing a cylinder device of one embodiment concerning the present invention, and a manufacturing device for the same. BRIEF DESCRIPTION OF THE DRAWINGS It is the cylinder apparatus of one Embodiment which concerns on this invention, and the fragmentary sectional view of the principal part which shows the manufacturing apparatus.

  An embodiment of the present invention will be described below with reference to the accompanying drawings.

  The cylinder device 10 of the present embodiment shown in FIG. 1 is a shock absorber used for a suspension device of an automobile or a railway vehicle. The cylinder device 10 according to the present embodiment is a hydraulic shock absorber using a working liquid as a working fluid, and more specifically, a hydraulic shock absorber using an oil liquid as a working liquid. The cylinder device 10 is mainly used for an automobile suspension device.

  The cylinder device 10 includes an inner cylinder 12, an outer cylinder 14 having a diameter larger than the inner cylinder 12 and arranged coaxially so as to form a reservoir chamber 13 between the inner cylinder 12, and a center axis of the inner cylinder 12. And a piston rod 15 whose one axial side is inserted into the inner cylinder 12 and the other axial side extends outside from the inner cylinder 12 and the outer cylinder 14, and which is connected to one end of the piston rod 15. A piston 18 is slidably inserted into the cylinder 12 to partition the inner cylinder 12 into two chambers 16 and 17. That is, the cylinder device 10 is a double-cylinder type in which the cylinder 19 has the inner cylinder 12 and the outer cylinder 14. The piston 18 is slidably inserted into the inner cylinder 12 of the cylinder 19, and partitions the inner cylinder 12 of the cylinder 19 into two chambers 16 and 17. The piston rod 15 has one end connected to the piston 18 and the other end extending outside the cylinder 19.

  The piston rod 15 moves integrally with the piston 18 connected to one end. The cylinder 19 has an inner cylinder 12 filled with an oil liquid as a working liquid, and a reservoir chamber 13 between the inner cylinder 12 and the outer cylinder 14 contains an oil liquid as a working liquid and a high-pressure liquid. Gas will be enclosed. The reservoir chamber 13 may be filled with atmospheric pressure air instead of high pressure gas.

  The cylinder device 10 includes a rod guide 20 disposed at an end position on the side where the piston rod 15 protrudes in the cylinder 19, and an end position on the side where the piston rod 15 protrudes within the cylinder 19 and A seal member 21 disposed outside the rod guide 20 in the axial direction and the base valve 23 disposed at an end of the cylinder 19 opposite to the rod guide 20 and the seal member 21 in the axial direction; ,have.

  Each of the rod guide 20 and the seal member 21 has an annular shape, and the piston rod 15 is slidably inserted inside each of them. The rod guide 20 supports the piston rod 15 so as to be movable in the axial direction while restricting the movement in the radial direction, and guides the movement of the piston rod 15. The seal member 21 is slidably contacted at its inner peripheral portion with the outer peripheral portion of the piston rod 15 which moves in the axial direction, and is connected to the oil liquid in the inner cylinder 12 and the high-pressure gas and oil liquid in the reservoir chamber 13 in the outer cylinder 14. From the cylinder 19 to the outside. In other words, the seal member 21 prevents leakage of the oil liquid and gas in the cylinder 19 from the cylinder device 10 to the outside.

  The outer cylinder 14 of the cylinder 19 has a substantially bottomed cylindrical shape having a cylindrical body member 25 and a bottom member 26 for closing one end side of the body member 25 opposite to the protruding side of the piston rod 15. I have. The body member 25 has a cylindrical body part 28 and a locking part 29 that protrudes radially inward from the position of the opening 27 on the side where the piston rod 15 of the body part 28 projects. A metal cover portion 31 is attached to the opening 27 side of the outer cylinder 14 so as to cover the locking portion 29 and the seal member 21.

  The cover part 31 is in contact with the locking part 29 on the side of the opening 27 of the cylinder 19 and covers the opening 27 of the cylinder 19 and the sealing member 21. A cylindrical portion 33 extending from the outer peripheral edge to one side in the axial direction and being press-fitted and fixed to the outer peripheral portion of the outer cylinder 14. The disc-shaped portion 32 has an insertion hole 34 through which the piston rod 15 is inserted. In other words, the cover portion 31 is formed with an insertion hole 34 through which the piston rod 15 is inserted, and comes into contact with one end of the cylinder 19.

  The inner cylinder 12 of the cylinder 19 has a cylindrical shape, and one end in the axial direction is supported in a fitted state with the base body 40 of the base valve 23 disposed inside the bottom member 26 of the outer cylinder 14. The other end in the direction is supported by the rod guide 20 fitted to the opening 27 side of the outer cylinder 14 in a fitted state.

  A nut 39 and a frequency sensitive part 41 are connected to the piston rod 15 alongside the piston 18. The nut 39 and the frequency sensitive part 41 are screwed into the piston rod 15, and the piston 18 is fastened to the end of the piston rod 15 inside the inner cylinder 12 by the nut 39 and the frequency sensitive part 41.

  In the base valve 23, a liquid passage 42 and a liquid passage 43 that can communicate the chamber 17 and the reservoir chamber 13 are formed in a base body 40. A disk valve 45 capable of opening and closing the radially inner liquid passage 42 and a disk valve 46 capable of opening and closing the radially outer liquid passage 43 are attached to the base body 40 with rivets 47.

  The disc valve 45 allows the flow of the hydraulic fluid from the chamber 17 to the reservoir chamber 13 while restricting the flow of the hydraulic fluid from the reservoir chamber 13 to the chamber 17 through the liquid passage 42. The disc valve 45 is a damping valve that causes the hydraulic fluid to flow from the chamber 17 to the reservoir chamber 13 when the piston rod 15 moves to the contraction side that reduces the amount of extension from the cylinder 19, thereby generating a damping force. .

  The disc valve 46 allows the flow of the working fluid from the chamber 17 to the reservoir 13 via the fluid passage 43 while allowing the flow from the reservoir 13 to the chamber 17. The disc valve 46 is a suction valve that allows the hydraulic fluid to flow from the reservoir chamber 13 to the chamber 17 without substantially generating a damping force when the piston rod 15 moves to the extension side where the amount of extension from the cylinder 19 is increased. is there.

  The piston 18 and the disc valves 51 and 52 on both sides thereof are attached to an end of the piston rod 15 on the side inserted into the inner cylinder 12 by a nut 39 and a frequency sensitive part 41. The piston 18 is formed with a liquid passage 53 and a liquid passage 54 that can communicate the chamber 16 with the chamber 17. The disc valve 51 can open and close a liquid passage 53, and the disc valve 52 can open and close a liquid passage 54.

  The disc valve 51 allows the flow of the hydraulic fluid from the chamber 17 to the chamber 16 while restricting the flow of the hydraulic fluid from the chamber 16 to the chamber 17 through the liquid passage 53. The disc valve 51 is a damping valve that causes the hydraulic fluid to flow from the chamber 17 to the chamber 16 via the liquid passage 53 when the piston rod 15 moves to the contraction side, and generates a damping force at that time.

  The disc valve 52 allows the flow of the working fluid from the chamber 16 to the chamber 17 while restricting the flow of the working fluid from the chamber 17 to the chamber 16 via the liquid passage 54. The disc valve 52 is a damping valve that causes the hydraulic fluid to flow from the chamber 16 to the chamber 17 via the liquid passage 54 when the piston rod 15 moves to the extension side, and generates a damping force at that time.

  The frequency responsive part 41 changes the damping force without being externally controlled by the frequency of the piston 18, and includes a housing 61, a free piston 62 slidably inserted into the housing 61, and a free piston 62. A pair of O-rings 63 and 64 are provided between the piston 62 and the housing 61 and are compressed and deformed when the free piston 62 moves in the axial direction with respect to the housing 61. The free piston 62 and the pair of O-rings 63 and 64 form a housing chamber 67 inside the housing 61. The housing chamber 67 is always in communication with a rod internal passage 68 formed in the piston rod 15 and constantly communicating with the chamber 16 via the liquid passage 54.

  When the frequency of the reciprocating motion of the piston 18 is high, the frequency responsive part 41 operates from the chamber 16 to the housing chamber 67 through the rod passage 68 of the piston rod 15 when the pressure of the chamber 16 increases during the extension stroke. While introducing the liquid, the free piston 62 moves toward the chamber 17 in the axial direction with respect to the housing 61 against the urging force of the O-ring 64 on the chamber 17 side in the axial direction. By moving the free piston 62 toward the chamber 17 in the axial direction, the hydraulic fluid is introduced into the housing chamber 67 from the chamber 16, and is introduced from the chamber 16 into the liquid passage 54 via the disk valve 52. The flow rate of the oil liquid flowing into the chamber 17 is reduced. This reduces the damping force.

  In the subsequent contraction stroke, the pressure in the chamber 17 increases, so that the hydraulic fluid is discharged from the housing chamber 67 of the frequency sensitive portion 41 to the chamber 16 via the rod passage 68 of the piston rod 15 while the chamber in the axial direction up to that point. The free piston 62 that has moved to the 17 side moves toward the chamber 16 in the axial direction with respect to the housing 61 against the urging force of the O-ring 63 located in the chamber 16 in the axial direction. As the free piston 62 moves toward the chamber 16 in the axial direction, the volume of the chamber 17 is increased, and the free piston 62 is introduced into the liquid passage 53 from the chamber 17 and flows into the chamber 16 via the disk valve 51. The liquid flow will be reduced. This reduces the damping force.

  When the frequency of the reciprocating motion of the piston 18 is low, the frequency of the movement of the free piston 62 is also low when the frequency of the reciprocating motion of the piston 18 is low, so that the hydraulic fluid flows from the chamber 16 to the housing chamber 67 at the beginning of the extension stroke. Thereafter, the free piston 62 compresses the O-ring 64 and stops on the chamber 17 side in the axial direction with respect to the housing 61, so that the working fluid does not flow from the chamber 16 to the housing chamber 67, so The flow rate of the hydraulic fluid introduced and flowing into the chamber 17 via the disk valve 52 does not decrease, and the damping force increases.

  In the subsequent contraction stroke, the volume of the chamber 17 is initially increased by the movement of the free piston 62 with respect to the housing 61, but thereafter, the free piston 62 compresses the O-ring 63 and moves in the axial direction with respect to the housing 61. Stop on the side of the chamber 16 and no longer affect the volume of the chamber 17, so that the flow rate of the working fluid introduced from the chamber 17 into the liquid passage 53 and flowing through the disk valve 51 to the chamber 16 does not decrease, and the damping force is reduced. Get higher.

  An annular locking member 71 is fixed between the piston 18 of the piston rod 15 and the rod guide 20, and an annular buffering member 72 is disposed on the rod guide 20 side of the locking member 71. I have. When the piston rod 15 moves close to the extended position, the shock absorbing member 72 abuts on the rod guide 20 and is elastically deformed, thereby absorbing an impact.

  A mounting eye 75 is fixed outside the bottom member 26 of the outer cylinder 14. When the cylinder device 10 is mounted on a vehicle, for example, the protruding side of the piston rod 15 from the cylinder 19 is disposed on the upper side, and is connected to the vehicle body side by a mounting portion 77 formed at the end thereof. Are arranged on the lower side and connected to the wheel side.

  As shown in FIG. 2, the seal member 21 includes a seal portion 81 made of an elastic rubber material, and a metal member embedded in the seal portion 81 to maintain the shape of the seal member 21 and obtain strength for fixing. An oil seal main body 83, which is an integrally formed product composed of an annular annular member 82; an annular spring 86 fitted to an outer peripheral portion of the seal portion 81 of the oil seal main body 83 in and out of the cylinder; An annular spring 87 is fitted on the outer peripheral portion on the inner side in and out of the cylinder.

  A radially inner portion of the seal portion 81 includes an annular cylindrical dust lip 91 extending in a direction away from the annular member 82 along the axial direction from the inside and outside of the cylinder on the inner peripheral side of the annular member 82, and an annular member. An annular oil lip 92 extends in a direction away from the annular member 82 along the axial direction from the inside of the cylinder inside and outside on the inner peripheral side of the oil lip 82.

  The dust lip 91 has a tapered cylindrical shape whose inner diameter becomes smaller as the distance from the annular member 82 to the outside in the cylinder inside and outside increases. The dust lip 91 has a radially inward recess at the axially intermediate portion of the outer peripheral portion, and the above-described spring 86 is fitted into this portion.

  The oil lip 92 has a tapered cylindrical shape whose diameter becomes smaller as the oil lip 92 moves away from the annular member 82 inward and outward in the cylinder. The oil lip 92 has a radially inward concave portion at the axially intermediate portion of the outer peripheral portion, and the above-described spring 87 is fitted into this portion.

  The seal member 21 has a seal portion 81 in which the dust lip 91 is disposed on the atmosphere side, that is, the outside of the cylinder inside and outside, and the oil lip 92 is disposed inside the inside and outside of the cylinder. The annular member 82 comes into sealing contact with the peripheral portion, and in this state, the position of the annular member 82 is nipped and locked by the rod guide 20 and the swaged locking portion 29 of the outer cylinder 14.

  The piston rod 15 is inserted inside the dust lip 91 and the oil lip 92 into the seal member 21 attached to the cylinder 19. In this state, one end of the piston rod 15 projects from one end of the cylinder 19, the dust lip 91 is provided on one end side of the cylinder 19 where the piston rod 15 projects, and the oil lip 92 is connected to the dust lip 91. Rather than inside the cylinder.

  The sealing member 21 ensures that the dust lip 91 comes into close contact with the piston rod 15 by the interference by the interference and the force of the spring 86 to secure the airtightness. The sealing property is ensured by closely adhering to the rod 15.

  In the seal member 21, the dust lip 91 protrudes outward in the axial direction of the cylinder 19 from the locking portion 29 of the cylinder 19. Here, as described above, since the disc-shaped portion 32 of the cover portion 31 comes into contact with the locking portion 29 of the cylinder 19, the axial position of the cover portion 31 overlaps the dust lip 91 of the seal member 21. For this reason, the insertion hole 34 of the disc-shaped portion 32 is sized so as not to interfere with the dust lip 91 and the spring 86 in which the piston rod 15 is inserted. That is, the insertion hole 34 has a larger diameter than the outer diameter of a portion that is axially aligned with the dust hole 91 and the insertion hole 34 of the spring 86. The insertion hole 34 is a straight hole 97 having a constant diameter on the side opposite to the cylindrical part 33 in the axial direction, and the diameter of the cylindrical part 33 in the axial direction becomes larger toward the cylindrical part 33. The tapered hole 98 is formed. In the insertion hole 34, the inner diameter of the straight hole portion 97 is the smallest.

  The piston rod 15 is in sliding contact with the seal member 21 and the rod guide 20 at a main shaft portion 102 having an outer peripheral surface 101 having a constant outer diameter. As shown in FIG. 1, the piston rod 15 has one end connected to the piston 18 and the other end extending out of the cylinder 19. The other end of the piston rod 15 is located radially inside the outer peripheral surface 101 of the main shaft portion 102. An annular groove 111 that is recessed in the direction is formed. The groove portion 111 is formed in the main shaft portion 102 at a position near the mounting portion 77 which is the end of the piston rod 15 on the side extending outside the cylinder 19.

  As shown in FIG. 2, the groove portion 111 includes a planar groove wall surface 112 extending in a direction perpendicular to the axis of the piston rod 15 in order from the side opposite to the axial mounting portion 77, and a piston extending from an inner peripheral edge of the groove wall surface 112. A cylindrical groove bottom surface 113 extending in the axial direction of the rod 15, and an axially farther radially outward from the end edge of the groove bottom surface 113 opposite to the groove wall surface 112, the radially outward from the groove wall surface 112. And a grooved wall surface 114 having a tapered shape. The groove bottom surface 113 matches the outer peripheral surface 101 of the main shaft portion 102 with the central axis.

  As shown in FIG. 1, the mounting portion 77 includes a small-diameter shaft portion 115 extending from the end of the main shaft portion 102 of the piston rod 15 opposite to the piston 18 to the opposite side to the piston 18, and a main shaft of the small-diameter shaft portion 115. A screw shaft portion 116 extending from the end opposite to the portion 102 to the side opposite to the piston 18, and extending from the other end of the screw shaft portion 116 on the side opposite to the small-diameter shaft portion 115 to the side opposite to the cylinder 19. And a tip shaft portion 117. The outer diameter of the largest diameter of the mounting portion 77 is slightly smaller than the outer diameter of the main shaft portion 102.

  The cylinder device 10 has a metal stopper 121 provided in the groove 111. The stopper 121 supports a mount 122 provided at the other end side of the groove portion 111 of the piston rod 15 having one end connected to the piston 18 and the other end extending out of the cylinder 19. The stopper 121 is a cylindrical member, and is fixed to the piston rod 15 by being caulked from the radial outside and partially entering the groove 111 in a state where the piston rod 15 is inserted inside. The mount 122 is provided with a telescopic boot 123 extending toward the cover 31 and fitted to the cover 31.

  Here, the stopper 121 is provided in the groove portion 111 so as to be located on the opposite side of the cylindrical portion 33 from the disc-shaped portion 32 of the cover portion 31, and the maximum outer diameter of the stopper 121 is set to Is larger than the minimum inside diameter. Thus, the stopper 121 contacts the disc-shaped portion 32 of the cover portion 31 before the frequency sensitive portion 41 attached to one end of the piston rod 15 contacts the base valve 23, and the frequency sensitive portion 41 23 is prevented.

  In this way, the stopper 121 whose maximum outer diameter is larger than the minimum inner diameter of the insertion hole 34 of the cover portion 31 is added to the groove portion 111 of the piston rod 15 and the main shaft portion 102 and the small diameter shaft portion 115 in the vicinity thereof. Install by tightening.

  Here, the stopper 121 before caulking has a shape shown in FIG. The stopper 121 before caulking is cylindrical, and has an end surface 161 formed of a plane that extends in the axis orthogonal direction on one side in the axial direction, and an end surface 162 (opposite surface) formed of a plane that expands in the axis orthogonal direction on the other axial side. An inner peripheral side wall surface 163 composed of a straight cylindrical surface of a constant diameter connecting the inner peripheral edges of the end surfaces 161 and 162; and a straight cylindrical surface of a constant diameter extending from the outer peripheral edge of the end surface 161 to the end surface 162 side. The outer peripheral side wall surface 165 (side wall surface) formed of a straight cylindrical surface of a constant diameter extending from the outer peripheral edge of the end surface 162 to the end surface 161 side, and the outer peripheral side wall surfaces 165 and 166 are connected to each other. And a tapered surface portion 168 having a tapered shape. Here, the outer diameter of the end surface 161 and the outer peripheral side wall surface 165 connected thereto is larger than the outer diameter of the end surface 162 and the outer peripheral side wall surface 166 connected thereto. Therefore, the tapered surface portion 168 has a tapered shape in which the diameter decreases from the outer peripheral side wall surface 165 side to the outer peripheral side wall surface 166 side.

  The stopper 121 before caulking also has an end surface 161 having the maximum outer diameter and an outer diameter of the outer peripheral side wall surface 165 connected to the end surface 161 larger than the minimum inner diameter of the insertion hole 34 of the cover portion 31 shown in FIG. I have.

  Therefore, when manufacturing the cylinder device 10, first, the base valve 23 and the inner cylinder 12 shown in FIG. 1 and the piston rod 15 are attached to the outer cylinder 14 before the locking portion 29 is formed. The disc valves 51 and 52, the piston 18, the nut 39, the frequency sensitive portion 41, the locking member 71 and the buffer member 72 in the closed state, and the rod guide 20 and the seal member 21 in which the piston rod 15 is inserted are arranged. In this state, a main assembling step of forming the locking portion 29 to form the cylinder device main body 125 is performed. After this main assembly process, the cover portion 31 is inserted into the insertion hole 34 by inserting the piston rod 15 of the cylinder device body 125 into the piston rod. A cover mounting process is performed to press-fit into the cylinder 19 until it comes into contact with the cylinder 29 and fix it to the cylinder 19 to form the assembly 155. After the cover attaching step, a stopper fixing step of fixing the stopper 121 to the piston rod 15 of the assembly 155 is performed. The cylinder device 10 is manufactured through the main assembly process, the piston rod insertion process, the cover mounting process, and the stopper fixing process.

  As shown in FIG. 4, the manufacturing apparatus 131 that performs the cover attaching step and the stopper fixing step includes a main body receiving jig 132 that receives the attaching eye 75 of the cylinder device main body 125 and a cover fixing jig that is put on the cover 31. A jig 133 and a pressing jig 134 arranged on the side opposite to the main body receiving jig 132 of the cover fixing jig 133.

  The main body receiving jig 132 has a concave portion 141 that is concave in a semicircular shape, and the mounting eye 75 is supported by the main body receiving jig 132 by arranging the mounting eye 75 on the opposite side to the cylinder 19 in the concave portion 141. I do. The cover fixing jig 133 includes a disc-shaped pressing plate 145 that abuts against the disc-shaped portion 32 of the cover 31, and extends to one side in the axial direction from the outer peripheral edge of the pressing plate 145. And an outer covering portion 146 that covers the 31 cylindrical portion 33 on the outside in the radial direction. The pressing plate 145 has an insertion hole 147 through which the piston rod 15 is inserted. The pressing jig 134 has a plate shape and comes into contact with the pressing plate 145 of the cover fixing jig 133. The pressing jig 134 has an insertion hole 151 through which the piston rod 15 is inserted.

  In the cover attaching process after the piston rod inserting process, the manufacturing apparatus 131 first supports the cylinder device main body 125 and the cover 31 with the main body receiving jig 132 and the cover fixing jig 133, and in this state, The pressing jig 134 presses the cover 31 via the cover fixing jig 133 which comes into contact with the disc 32 of the cover 31 by the pressing plate 145, and the disc 32 is locked. The cylindrical portion 33 is pressed into the outer cylinder 14 of the cylinder 19 until it comes into contact with the portion 29. In this state, in the manufacturing apparatus 131, the body receiving jig 132, the cover fixing jig 133, and the pressing jig 134 position and hold the assembly 155 of the cylinder device main body 125 and the cover 31.

  In the assembly 155 after the cover attaching step, a part of the seal member 21 on the tip end surface 95 side of the dust lip 91 enters the tapered hole 98 of the insertion hole 34 of the cover 31, but the area of the tapered hole 98 Inside, and does not protrude out of the disc-shaped portion 32.

  The manufacturing apparatus 131 has a positioning jig 171 for positioning the stopper 121 before caulking in the axial direction. The positioning jig 171 is cylindrical and has an insertion hole 172 through which the piston rod 15 is inserted. The positioning jig 171 is placed on the opposite side of the pressing jig 134 from the cover fixing jig 133, and in this state, a planar positioning surface portion on the opposite side to the pressing jig 134. 173 extends orthogonally to the axial direction of the piston rod 15. When the pressing jig 134 presses the cover portion 31 via the cover fixing jig 133 and presses into the outer cylinder 14 until the disc-shaped portion 32 comes into contact with the locking portion 29, the positioning is performed. The jig 171 is in a positioning state in which the positioning surface 173 is positioned in the axial direction with respect to the groove 111 of the piston rod 15.

  The stopper 121 before caulking is placed on the positioning surface 173 of the positioning jig 171 with the piston rod 15 inserted through the stopper 121. When in the positioning state, the positioning jig 171 positions the stopper 121 placed on the positioning surface 173 before crimping in the axial direction with respect to the groove 111.

  The manufacturing apparatus 131 has a stopper fixing jig 181 for holding the stopper 121 before caulking with the positioning jig 171 in the positioning state. The stopper fixing jig 181 has a flat opposing surface 182 that faces in parallel with the positioning surface 173 of the positioning jig 171, and an accommodation hole that opens to the positioning jig 171 and accommodates the mounting portion 77 of the piston rod 15. 183, and a fixing hole 184 provided on the side of the facing surface 182 with respect to the accommodation hole 183.

  As shown in FIG. 5, the fixing hole 184 is opened in the facing surface 182, and the facing surface 182 in the axial direction has a straight cylindrical inner peripheral surface 191 having a constant diameter orthogonal to the facing surface 182. The opposite side of the axially facing surface portion 182 is a flat pressing surface 192 parallel to the facing surface portion 182. The stopper fixing jig 181 fits the outer peripheral side wall surface 166 of the stopper 121 before caulking to the inner peripheral surface portion 191 of the fixing hole 184 to position the stopper 121 in the radial direction, and attaches the end surface 162 to the pressing surface 192. Then, the stopper 121 before crimping is pressed from the side opposite to the positioning jig 171. Thus, the stopper 121 before caulking is axially positioned and fixed to the positioning jig 171 and the stopper fixing jig 181 in the positioning state.

  The manufacturing apparatus 131 is a shrinking tool for plastically deforming the stopper 121 before caulking, which is fixed to the positioning jig 171 and the stopper fixing jig 181 in the positioning state, from the outside in the radial direction toward the center axis line. 201. A plurality of shrinking tools 201 are radially arranged at equal intervals in the circumferential direction around the center axis, with the positions of the fixing holes 184 of the stopper fixing jig 181 aligned in the center axis direction. The shrinking tool 201 performs shrinking in which the stopper 121 before crimping is pressed from the outside in the radial direction in the processing portion 202 facing the center axis of the fixing hole 184.

  Each of the plurality of shrinking tools 201 faces in parallel with the opposing surface portion 182 of the stopper fixing jig 181, and opposes in parallel with the positioning surface portion 173 of the positioning jig 171. And a flat facing surface portion 204.

  Each of the plurality of shrinking tools 201 has, in order from the side of the facing surface 203, a part 211 of a cylindrical surface orthogonal to the facing surfaces 203 and 204, and a part of a tapered surface. , A surface portion 213 that forms a part of a cylindrical surface orthogonal to the facing surface portions 203 and 204, and a surface portion 214 that forms a part of a tapered surface.

  When all the plurality of shrinking tools 201 are at the forward end positions closest to the center axis of the fixing hole 184, the plurality of surface portions 211 are arranged on the same cylindrical surface, and the plurality of surface portions 212 are arranged on the same taper surface. The plurality of surface portions 213 are arranged on the same cylindrical surface, and the plurality of surface portions 214 are arranged on the same tapered surface. In the shrinking tool 201, the surface portion 211 is connected to the facing surface portion 203, and the surface portion 214 is connected to the facing surface portion 204.

  In the processed portion 202, the distance from the central axis of the fixing hole 184 is shorter in the surface portion 213 than in the surface portion 211. The maximum distance of the surface portion 214 from the central axis of the fixing hole 184 is longer than the distance from the central axis of the fixing hole 184 to the surface 211. In the processed portion 202, the length of the fixing hole 184 in the axial direction is increased in the order of the surface 212, the surface 211, the surface 213, and the surface 214. The angle of the fixing hole 184 with respect to the central axis is smaller in the surface portion 214 than in the surface portion 212.

  The plurality of shrinking tools 201 are mounted on the main body receiving jig 132, the cover fixing jig 133, and the pressurizing jig 134. The surface portion 212 overlaps the groove wall surface 114, the surface portion 213 overlaps the groove wall surface 114 and the groove bottom surface 113, and the surface portion 214 overlaps the groove bottom surface 113 and the groove wall surface 112 in the axial direction.

  In the stopper fixing step, the piston rod 15 of the assembly 155 is positioned by the main body receiving jig 132, the cover fixing jig 133, and the pressing jig 134, and the positioning jig 171 and the stopper fixing jig 181 in the positioning state are set. Thus, the plurality of shrinking tools 201 are simultaneously driven while the stopper 121 before crimping is fixed.

  At this time, the stopper 121 before caulking has an end surface 162 facing the opposite side to the cover portion 31 abuts against the pressing surface 192 of the fixing hole portion 184, and a part of the outer peripheral side wall surface 166 connected to the end surface 162 has a fixing hole portion. The end surface 161 that is fitted to the inner peripheral surface portion 191 of the positioning jig 184 and faces the cover portion 31 is in contact with the positioning surface portion 173 of the positioning jig 171. For this reason, the manufacturing apparatus 131 restrains the end face 162 and a part of the outer peripheral side wall face 166 connected to the end face 162 with the stopper fixing jig 181, and restricts the end face 161 with the positioning jig 171 while forming the plurality of stoppers 121 before caulking. Is plastically deformed by the shrinking tool 201. At this time, the plurality of shrinking tools 201 advance, for example, to a position where the surface portion 211 contacts the outer peripheral side wall surface 166 of the stopper 121 before crimping without plastically deforming the stopper.

  By performing the stopper fixing step, the processing portion 202 forms a concave portion 222 that is recessed radially inward from the outer peripheral side wall surfaces 165 and 166 on the outer peripheral side wall 221 of the stopper 121 by the processing portion 202. A protruding portion 225 (pressing portion) that protrudes radially inward from the inner peripheral side wall surface 163 and enters the groove portion 111 of the piston rod 15 is formed on the inner side wall 224 (side wall) on the inner side in the direction. In addition, an end-side convex portion 226 that protrudes radially inward from the inner peripheral wall surface 163 and contacts the small-diameter shaft portion 115 is formed on the inner wall 224 (side wall).

  That is, the stopper 121 has an inner wall 224 including an inner peripheral wall surface 163 provided at a position facing the groove 111, and the inner wall 224 has a convex shape that is pressed toward the groove 111 and enters the groove 111. An end-side convex portion 226 is formed to be locked to the portion 225 and the attachment portion 77 side of the main shaft portion 102. The protruding portion 225 is plastically deformed and provided in the groove portion 111, and the end-side protruding portion 226 is also plastically deformed and locked on the mounting portion 77 side of the main shaft portion 102.

  A plurality of the concave portions 222, the convex portions 225, and the end-side convex portions 226 are aligned with each other in the center axis direction of the fixing hole portion 184 of the stopper fixing jig 181 in the same manner as the shrinking tool 201. They are arranged radially at equal intervals in the circumferential direction about the center axis. As a result, a plurality of the concave portions 222, the convex portions 225, and the end-side convex portions 226 are respectively aligned with the stopper 121 in the center axis direction of the stopper 121, and are arranged in the circumferential direction around the center axis. They are arranged radially at intervals.

  The stopper 121 has a shape in which each concave portion 222 follows the processing portion 202 of the shrinking tool 201. That is, the concave portion 222 is formed by the surface portion 212 and follows the surface portion 212 and forms a part of the tapered surface, and the end portion 161 is formed by the surface portion 213 and follows the surface portion 213. , 162, and a surface portion 233 that forms a part of a cylindrical surface, and a surface portion 234 that is formed by the surface portion 214 and forms a part of a tapered surface in a shape following the surface portion 214. . The plurality of surface portions 232 of the plurality of concave portions 222 are arranged on the same tapered surface, the plurality of surface portions 233 are arranged on the same cylindrical surface, and the plurality of surface portions 234 are arranged on the same tapered surface.

  The plurality of concave portions 222 position the axial position of the piston rod 15 with respect to the groove portion 111 of the piston rod 15 such that the surface portion 232 overlaps the groove wall surface 114, and the surface portion 233 overlaps the groove wall surface 114 and the groove bottom surface 113. The surface portion 234 overlaps the groove bottom surface 113 and the groove wall surface 112.

  In the stopper fixing step, the outer peripheral portion of the stopper 121 is deformed by shrinking. However, since the end surface 161 is restricted by the planar positioning surface portion 173 of the positioning jig 171, the deformation is restricted. Is maintained in a state. Further, the end face 162 is restrained by a flat pressing surface 192 of the stopper fixing jig 181 to restrict the deformation, and a part of the outer peripheral side wall surface 166 on the end face 162 side is a cylindrical surface of the stopper fixing jig 181. Deformation is restricted by the inner peripheral surface portion 191 of the shape. For this reason, the end surface 162 is maintained in a planar shape, and a part of the outer peripheral side wall surface 166 on the end surface 162 side is maintained in a cylindrical shape. The stopper 121 after caulking also has a maximum outer diameter of the end face 161 and a part of the outer diameter of the outer peripheral side wall face 165 that is larger than the minimum inner diameter of the insertion hole 34 of the cover part 31 shown in FIG. It has become.

  As shown in FIG. 2, the mount 122 mainly made of rubber comes into contact with the end face 162 of the stopper 121, and in this state, the stopper 121 supports the mount 122. At this time, even after shrinking as described above, the end surface 162 maintains a planar shape, and a part of the outer peripheral side wall surface 166 on the end surface 162 side maintains a cylindrical shape. Is prevented from being caught or scratched.

  Patent Document 1 discloses a cylinder including a cylinder in which a working fluid is sealed, a piston inserted into the cylinder, and a piston rod having one end connected to the piston and the other end extending outside the cylinder. In the apparatus, a technique is described in which a mounting eye is swaged and fixed to a piston rod. By the way, in a cylinder device, if a seal member that slides on a piston rod to prevent the working fluid from leaking out of the cylinder is damaged, the working fluid may leak out of the cylinder, resulting in reduced reliability. Resulting in. Further, even if the mount supported by the stopper is damaged, the reliability is reduced.

  On the other hand, in the cylinder device 10 of the present embodiment, the stopper 121 provided in the groove 111 formed on the other end of the piston rod 15 having one end connected to the piston 18 and the other end extending outside the cylinder 19 is provided. An insertion hole 34 through which the piston rod 15 is inserted is formed, and has a diameter larger than the inner diameter of the insertion hole 34 of the cover portion 31 abutting on one end side of the cylinder 19. Therefore, it is possible to restrict the stopper 121 from entering the insertion hole 34 of the cover 31. Therefore, the contraction position of the piston rod 15 can be defined by the stopper 121 abutting on the cover portion 31. As a result, even if the piston rod 15 moves to the contracted and cut position, the stopper 121 does not come into contact with the seal member 21, so that damage to the seal member 21 can be suppressed. Therefore, the reliability can be improved.

  Further, since the stopper 121 is plastically deformed and provided in the groove 111 formed in the piston rod 15, even if the stopper 121 has a diameter larger than the inner diameter of the insertion hole 34 of the cover 31, The stopper 121 can be easily attached to the piston rod 15. Therefore, even after assembling the cylinder device main body 125 and assembling the cover portion 31 into the assembly 155, the stopper 121 can be easily and securely attached to the piston rod 15.

  That is, for example, when the stopper is pressed into the piston rod in the axial direction and fixed, it is necessary to press-fit the stopper into the piston rod in a single state. After that, the insertion hole of the cover attached to the cylinder device main body must have an inside diameter that allows the stopper to pass through. With such a structure, there is a possibility that the stopper abuts on the seal member. On the other hand, in the cylinder device 10, since the stopper 121 is provided in the groove 111 formed in the piston rod 15 by plastic deformation, the stopper 121 is retrofitted with a larger diameter than the inner diameter of the insertion hole 34 of the cover 31. The contact of the stopper 121 with the seal member 21 can be restricted by the cover 31.

  In addition, since the stopper 121 is plastically deformed and provided in the groove 111 formed in the piston rod 15, the number of parts is reduced as compared with the case where a C ring or the like is attached to the groove of the piston rod to support the stopper. can do.

  The stopper 121 has an inner wall 224 provided at a position facing the groove 111 of the piston rod 15, and the inner wall 224 has a convex portion 225 pressed toward the groove 111. Therefore, the attachment of the stopper 121 to the piston rod 15 is further ensured.

  The method of manufacturing the cylinder device 10 according to the present embodiment includes the stopper 121 provided in the groove 111 formed on the other end of the piston rod 15 having one end connected to the piston 18 and the other end extending outside the cylinder 19. Is fixed to the piston rod 15, the stopper 121 plastically deforms the stopper 121 while restraining the end surface 162 facing the opposite side of the cover portion 31 and a part of the outer peripheral side wall surface 166 connected to the end surface 162. Since the stopper 15 is fixed to the rod 15, it is possible to prevent the end face 162 of the stopper 121 and a part of the outer peripheral side wall face 166 connected to the end face 162 from being reduced in roughness such as unevenness. Therefore, even if the mount 122 mainly made of rubber is in contact with the end surface 162 of the stopper 121, damage to the mount 122 can be suppressed. Therefore, the reliability of the mount 122 can be improved.

  The first aspect of the embodiment described above is a cylinder in which a working fluid is sealed, a piston inserted into the cylinder, and one end connected to the piston and the other end extending outside the cylinder. A piston rod, a seal member slidingly in contact with the piston rod to prevent the working fluid from leaking out of the cylinder, and a cover portion formed with an insertion hole through which the piston rod is inserted to contact one end of the cylinder And a groove formed on the other end of the piston rod, and a stopper provided in the groove and supporting a mount provided on the other end of the piston rod relative to the groove. The diameter is larger than the inner diameter of the insertion hole of the cover portion. This makes it possible to improve reliability.

  In a second aspect based on the first aspect, the stopper is plastically deformed and provided in the groove.

  According to a third aspect, in the second aspect, the stopper has a side wall provided at a position facing the groove of the piston rod, and the side wall has a pressing portion pressed toward the groove. Is formed. This makes it possible to improve reliability.

  A fourth aspect is a cylinder filled with a working fluid, a piston inserted into the cylinder, a piston rod having one end connected to the piston and the other end extending outside the cylinder, A sealing member that slides against the cylinder to prevent the working fluid from leaking out of the cylinder; a cover formed with an insertion hole through which the piston rod is inserted to abut one end of the cylinder; A method for manufacturing a cylinder device, comprising: a groove formed on an end side; and a stopper provided in the groove and supporting a mount provided on the other end side of the piston rod than the groove. A piston rod insertion step of inserting a piston rod into the cover portion, a stopper fixing step of fixing the stopper to the piston rod, The stopper fixing step includes fixing the stopper to the piston rod by plastically deforming the stopper while restraining an opposite surface facing the cover portion of the stopper and a part of a side wall surface connected to the opposite surface. I do. This makes it possible to improve reliability.

DESCRIPTION OF SYMBOLS 10 Cylinder device 19 Cylinder 18 Piston 15 Piston rod 21 Seal member 34 Insertion hole 31 Cover part 111 Groove part 121 Stopper 122 Mount 162 End surface (opposite surface)
166 Outer side wall surface (side wall surface)
224 Inner wall (side wall)
225 convex part (pressing part)

Claims (4)

A cylinder filled with a working fluid,
A piston inserted into the cylinder,
A piston rod having one end connected to the piston and the other end extending out of the cylinder;
A sealing member that slides on the piston rod to prevent the working fluid from leaking out of the cylinder;
A cover portion formed with an insertion hole through which the piston rod is inserted to abut one end of the cylinder;
A groove formed on the other end of the piston rod;
A stopper that is provided in the groove portion and that supports a mount provided on the other end side of the piston rod with respect to the groove portion;
With
The cylinder device, wherein the stopper has a diameter larger than an inner diameter of the insertion hole of the cover portion.   The cylinder device according to claim 1, wherein the stopper is plastically deformed and provided in the groove. The stopper has a side wall provided at a position facing the groove of the piston rod,
The cylinder device according to claim 2, wherein a pressing portion that is pressed toward the groove is formed on the side wall. A cylinder filled with a working fluid,
A piston inserted into the cylinder,
A piston rod having one end connected to the piston and the other end extending out of the cylinder;
A sealing member that slides on the piston rod to prevent the working fluid from leaking out of the cylinder;
A cover portion formed with an insertion hole through which the piston rod is inserted to abut one end of the cylinder;
A groove formed on the other end of the piston rod;
A stopper that is provided in the groove portion and that supports a mount provided on the other end side of the piston rod with respect to the groove portion;
A method for manufacturing a cylinder device comprising:
A piston rod insertion step of inserting the piston rod into the cover portion,
A stopper fixing step of fixing the stopper to the piston rod,
The stopper fixing step includes fixing the stopper to the piston rod by plastically deforming the stopper while restraining an opposite surface facing the cover portion of the stopper and a part of a side wall surface connected to the opposite surface. A method for manufacturing a cylinder device.

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