JP2010175043A - Manufacturing method of cylinder device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method for a cylinder device such as a hydraulic damper capable of eliminating the need for masking for a sliding part of a piston rod when coating is conducted. <P>SOLUTION: A cap member 7 is installed at the tip of the piston rod 3 protruding from a cylinder part 2, and a lock member 12 is attached to the end of the cylinder part 2 and cut up upward to form an engagement part 13. The cap member 7 is cut up downward to form an engaging piece 14 and a window 15. Before attaching a dust cover 8, the piston rod 3 is shortened to around the minimum length position, and the cap member 7 is rotated for engagement of the engagement part 13 with the engaging piece 14, to lock the piston rod 3. This allows the cylinder part 2 to be coated in the condition that the piston rod 3 is shortened, which eliminates the need for masking the sliding part of the piston rod 3. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method of manufacturing a cylinder device in which a rod protrudes from one end of a cylinder portion such as a hydraulic shock absorber or a gas spring.

  For example, in the case of a cylindrical hydraulic shock absorber mounted on a suspension system of an automobile, the piston rod is used in order to protect the space of the piston rod from the generation of rust and dirt, and the efficiency of the space when transporting and storing. Is preferably held near the minimum length position. However, in a hydraulic shock absorber filled with a gas that constantly pressurizes oil in the cylinder for the purpose of preventing cavitation or the like, the piston rod is normally extended by the gas pressure.

  Therefore, conventionally, at the time of transportation and storage, the piston rod is restrained at the minimum length position using a synthetic resin band or metal wire, or, for example, as described in Patent Document 1, a hydraulic buffer is used. An engagement member that can be engaged with and disengaged from each other is attached to the distal ends of the main body and the piston rod, and these engagement members are engaged with each other to hold the piston rod at the minimum length position. Further, in the painting process at the time of manufacturing the hydraulic shock absorber, the cylinder portion is painted by masking the extended piston rod.

Japanese Utility Model Publication No. 2-132147

  In the coating process of the conventional hydraulic shock absorber, since the extended piston rod is masked, the masking operation is complicated, and the paint adhering to the masking portion is wasted. Furthermore, since it is difficult to completely mask the base of the piston rod, there is a risk that the paint may adhere to the sliding portion of the piston rod, which is a problem.

  An object of the present invention is to provide a method of manufacturing a cylinder device that eliminates the need for masking of a sliding portion of a rod when performing coating.

In order to solve the above problems, the present invention provides a cylinder in which a fluid is sealed, a rod projecting from one end of the cylinder so as to expand and contract, and an extension direction of the rod with respect to the cylinder with the rod shortened. A cylinder device comprising a lock means for restricting movement, comprising:
It includes an assembling process for assembling the cylinder device, and a painting process for painting in a state where movement of the rod in the extending direction is restricted by the locking means.

  According to the cylinder device manufacturing method according to the invention, since the rod is painted in a shortened state, masking of the sliding portion of the rod becomes unnecessary.

It is a side view which shows a partially broken main part of a hydraulic shock absorber to which a method for manufacturing a cylinder device according to a first embodiment of the present invention is applied. FIG. 2 is a diagram showing a state where a piston rod is locked in the hydraulic shock absorber of FIG. 1. It is a side view of the hydraulic shock absorber of FIG. It is a perspective view which expands and shows the locking mechanism of the hydraulic shock absorber shown in FIG. It is a figure which shows the process of locking the piston rod of a hydraulic shock absorber in the minimum length position in the manufacturing method of the cylinder apparatus which concerns on one Embodiment of this invention. It is a figure which shows the coating process of the cylinder part of a hydraulic shock absorber in the manufacturing method of the cylinder apparatus which concerns on one Embodiment of this invention. It is a figure which shows the manufacturing process of the hydraulic shock absorber after coating in the manufacturing method of the cylinder apparatus which concerns on one Embodiment of this invention.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
A hydraulic shock absorber that is a cylinder device to which the method for manufacturing a cylinder device according to the present embodiment is applied will be described with reference to FIGS. 1 to 4.
As shown in FIGS. 1 to 3, the hydraulic shock absorber 1 is a cylindrical hydraulic shock absorber, and a piston (not shown) can slide on a cylinder (not shown) provided in the cylinder portion 2. A rod guide (not shown) and an oil which are connected to one end of a piston rod 3 (rod) and the other end of the piston rod 3 is attached to an end of the cylinder portion 2. It is inserted through the seal 5 and protrudes outside the cylinder part 2. An oil liquid is sealed in the cylinder portion 2 as a fluid.

  The hydraulic shock absorber 1 includes an oil passage in which an oil flow is generated by sliding of a piston in a cylinder, and an orifice and a disk valve that generate a damping force by controlling the flow of the oil (not shown) in the oil passage. A damping force generating mechanism (not shown) made up of and the like is provided. The cylinder portion 2 is provided with a reservoir (not shown) filled with compressed gas, so that the volume change in the cylinder accompanying the expansion and contraction of the piston rod 3 is compensated by compression and expansion of the gas in the reservoir. It has become. Alternatively, a free piston (not shown) may be slidably fitted on the bottom side of the cylinder to form a gas chamber (not shown), and high pressure gas may be sealed in the gas chamber. In addition, even if the present invention is filled with atmospheric gas with the piston rod extended, when the piston rod is thick, the cylinder internal pressure increases when the piston rod is shortened. May apply.

  A substantially disc-shaped cap member 7 spreading in the radial direction as a flange is attached to the tip of the piston rod 3 by welding or the like, and the upper end of the cylindrical dust cover 8 is fitted into the outer periphery of the cap member 7. Is fixed. The dust cover 8 is slightly larger in diameter than the cylinder part 2 and covers the cylinder part 2 and the piston rod 3, and the lower end part thereof is located at the upper end part of the cylinder part 2 when the piston rod 3 is at the maximum length position. Stretched to reach. The dust cover 8 can be fitted and fixed to the cap member 7 by covering the piston rod 3 from the tip end side of the piston rod 3 and press-fitting the upper end portion of the dust cover 8 into the cap member 7.

  At the tip of the piston rod 3, there is formed a mounting portion 9 consisting of a screw portion or the like for connecting to a suspension member on the vehicle body side, and at the bottom of the cylinder portion 2 is connected to a suspension member such as a suspension arm. A mounting eye 10 is attached. A bush 10 </ b> A is press-fitted into the mounting eye 10.

  The hydraulic shock absorber 1 is provided with a lock mechanism 11 as a lock means for restricting movement in the extending direction in a state where the piston rod 3 is shortened. Next, the lock mechanism 11 will be described.

  A substantially ring-shaped lock member 12 is attached to an upper end portion of the cylinder portion 2 from which the piston rod 3 is projected. The lock member 12 is fitted into the cylinder part 2 in a state of being superimposed on the retainer 5A of the oil seal 5, and the cylinder part 2 together with the rod guide and the oil seal 5 is crimped by caulking the upper end part of the cylinder part 2 inward. It is fixed to the upper end of the. As shown in FIG. 4, the lock member 12 has a substantially rectangular engagement portion 13 in which two portions in the diameter direction of the inner peripheral portion are cut and raised upward, and one end portion in the inner peripheral portion and the circumferential direction is opened. Is formed as a cylinder side engaging portion.

  The cap member 7 attached to the piston rod 3 has two outer peripheral portions in the diametrical direction on the inner peripheral side facing the engaging portion 13 of the lock member 12, and is lowered downward from the outer peripheral portion of the piston rod 3. A substantially rectangular engagement piece 14 extending in the diameter direction is formed as a buttock side engagement portion. The cap member 7 is formed with a window portion 15 of that shape by cutting the engaging piece 14 downward. Then, the engagement piece 14 is rotated under the engagement portion 13 through the opening of the engagement portion 13 of the lock member 12 by rotating the cap member 7 with the piston rod 3 shortened to the almost minimum position. Engagement, that is, the engaging portion 13 engages on the engaging piece 14 (on the distal end side of the piston rod 3), thereby causing the piston rod 3 to include the minimum length position (including the vicinity of the minimum length position. ) Can be locked. In this embodiment, the cap member 7 is welded and fixed to the piston rod 3 and thus rotates together with the piston rod 3 (that is, the piston). However, the cap member 7 can be rotated with respect to the piston rod 3. You may make it attach.

Next, the operation of the hydraulic shock absorber 1 configured as described above will be described.
In response to expansion and contraction of the piston rod 3, the flow of the oil generated in the oil passage in the cylinder portion 2 by the movement of the piston is controlled by a damping force generation mechanism including an orifice and a disk valve to generate a damping force. At this time, the volume change in the cylinder accompanying the entry and withdrawal of the piston rod 3 is compensated by the compression and expansion of the gas in the reservoir or gas chamber.

  Due to the pressure of the gas in the reservoir or gas chamber, a force in the extending direction always acts on the piston rod 3. When the piston rod 3 is locked at the minimum length position for storage and transportation of the hydraulic shock absorber 1, as shown in FIG. 1, the piston rod 3 is against the pressure of gas in the reservoir or gas chamber. The cap member 7 is rotated to the vicinity of the minimum length position, and the cap member 7 is rotated in this state, and the engagement piece 14 of the cap member 7 attached to the piston rod 3 is fixed to the cylinder portion 2 as shown in FIG. The engaging member 13 is engaged with the engaging portion 13. Thereby, the piston rod 3 can be locked in the minimum length position.

When the piston rod 3 is unlocked, the piston rod 3 is rotated in the opposite direction to that at the time of locking, and the engagement between the engagement portion 13 and the engagement piece 14 is released, thereby releasing the lock. be able to. Note that the engagement between the engagement portion 13 and the engagement piece 14 can be smoothly released by rotating the piston rod 3 while pressing it in the shortening direction.
At this time, since the engaging portion 13 engages on the engaging piece 14, the engagement state of the engaging portion 13 and the engaging piece 14 is easily visually confirmed in the window portion 15 of the cap member 7. Can be locked and unlocked easily.

Moreover, since the engaging part 13 and the engaging piece 14 are formed by cutting and raising the disk-shaped lock member 12 and the cap member 7, the axial dimension can be made sufficiently small, and the piston rod 3 There is almost no effect on the stroke.
Note that the shortest length lock structure applied to the present invention is such that, if the lock-unlock operation can be easily performed after the hydraulic shock absorber is assembled, for example, a male screw is formed at the tip of the piston rod and a female screw is formed at the rod guide portion. However, the configuration of the above embodiment is most desirable because the angle of rotation for locking is small and the locked state can be visually observed from the rod tip side.
In addition, the piston rod and the bottom portion may be engaged with each other in the cylinder, but in this case, the inside is not visible and the workability is poor, so that the effect of the present invention can be obtained. Is desirable.

Next, a method for manufacturing the hydraulic shock absorber 1 will be described with reference to FIGS.
In the assembly process, a cylinder, a base valve or a free piston, a piston, a piston rod 3 to which a cap member 7 is attached, a rod guide, an oil seal 5, a lock member 12, and the like are incorporated into the cylinder portion 2 so that oil and gas 1A is obtained in a state in which is enclosed. The hydraulic shock absorber 1 is completed by performing each step on the shock absorber main body 1A as described below.

  With reference to FIG. 5 (A), the rod expansion-contraction apparatus which is a manufacturing apparatus used for the process of this invention is demonstrated. As shown in FIG. 5A, the rod telescopic device 20 is provided with a holding mechanism 22 that holds the shock absorber main body 1A in an upright state at the lower part of the C-shaped frame 21, and is held by the holding mechanism 22 at the upper part. A rod expansion / contraction mechanism 23 is provided opposite to the mounting portion 9 of the piston rod 3 of the shock absorber body 1A.

  The holding mechanism 22 grips the mounting eye 10 to hold the shock absorber main body 1A in an upright state, and can rotate the cylinder portion 2 around the axis by a predetermined angle in both directions. The holding mechanism 22 can be configured by a combination of a drive source such as a motor, an air cylinder, and a solenoid, and a mechanical element such as a speed reduction mechanism and a link mechanism, or may be manually operated. The holding mechanism 22 may be provided with a cylinder holding mechanism that holds only in the vertical direction and prevents it from falling down separately.

  In the rod expansion / contraction mechanism 23, an engagement head 26 that is engaged with the distal end portion of the piston rod 3 is attached to the distal end portion of the operating rod 25 of the air cylinder 24. The engaging head 26 has a substantially bottomed cylindrical shape, the operating rod 25 is connected to the bottom, the cylindrical portion 27 into which the mounting portion 9 at the tip of the piston rod 3 is inserted, and the cap member 7 fixed to the piston rod 3. The flange portion 28 whose diameter is increased to be in contact with is integrally formed. The flange portion 28 protrudes with a claw portion 29 that engages with the window portion 15 of the cap member 7 and prevents rotation of the cap member 7 around the axis. The claw portion 29 has a protruding height that does not penetrate the cap member 26 so as not to interfere with the engaging portion 13 on the cylinder portion 2 side when engaged with the window portion 15 of the cap member 26. The flange portion 28 is expanded in diameter so as to cover the outer periphery of the upper end portion of the dust cover 8.

  The air cylinder 24 is a double-acting air cylinder, and is provided with a shortened position where the engagement head 26 is separated from the piston rod 3 of the shock absorber main body 1A as shown in FIG. The operating rod 25 can be expanded and contracted between the extended position where the piston rod 3 is pushed and contracted to the minimum position by the engagement head 26 shown in FIG.

Next, the pre-painting rod shortening process painting process will be described with reference to FIG.
As shown in FIG. 5A, the shock absorber main body 1A in which the piston rod 3 is extended by the pressure of the sealed gas is set on the rod telescopic device 20 and held in an upright state by the holding mechanism 22. As shown in FIG. 5 (B), the air cylinder 24 of the rod expansion / contraction mechanism 23 is operated, the operation rod 25 is extended, and the engagement head 26 is put on the tip of the piston rod 3 of the shock absorber main body 1A. 29 is engaged with the window portion 15 of the cap member 7. At this time, the buffer body 1A is appropriately rotated by the holding mechanism 22 so that the window portion 15 of the cap member 7 and the claw portion 29 of the engagement head 26 can be engaged with each other, and these phases are matched.

As shown in FIG. 5C, the operating rod 25 is further extended to shorten the piston rod 3 to the minimum length position against the gas pressure. In this state, the cylinder portion 2 is rotated by the holding mechanism 22 so that the engaging portion 13 and the engaging piece 14 are engaged, and the piston rod 3 is locked at the minimum length position. At this time, the engagement piece 14 is restricted from rotating about its axis when the claw portion 29 of the engagement head 26 engages the window portion 15 of the cap member 7. Thereafter, the operating rod 25 is shortened, the engagement head 26 is separated from the piston rod 3, the holding by the holding mechanism 22 is released, and the shock absorber main body 1 </ b> A is removed from the rod telescopic device 20.
In the present invention, the pre-painting rod shortening step is not necessary when the piston rod 3 is assembled in a state of being shortened and locked in advance in the assembly step.

  Next, the painting process will be described with reference to FIG. The shock absorber main body 1A in a state where the piston rod 3 is locked at the minimum length position is set in the coating apparatus 30, and the cylinder portion 2 is painted by spraying paint while moving the nozzle 31 appropriately. At this time, the piston rod 3 is locked at the minimum length position, and the sliding part is accommodated in the cylinder part 2, so that masking of the sliding part is unnecessary. Therefore, a minimum masking such as a threaded portion at the tip of the rod may be performed as necessary.

  After completion of the painting process, a releasing process for releasing the lock of the piston rod 3 is performed as follows. As shown in FIG. 7A, the shock absorber main body 1 </ b> A in which the piston rod 3 is locked at the minimum length position is set on the rod telescopic device 20 and is held by the holding mechanism 22. Then, the operating rod 25 of the telescopic mechanism 23 is extended, and the engaging head 26 is put on the tip of the piston rod 9 of the shock absorber main body 1 </ b> A to engage the claw portion 29 with the window portion 15 of the cap member 7. At this time, the shock absorber main body 1A is appropriately rotated by the holding mechanism 22 so that the window portion 15 of the cap member 7 and the claw portion 29 of the engagement head 26 can be smoothly engaged, and these phases are matched. In this state, the cylinder portion 2 is rotated by the holding mechanism 22 to release the engagement between the engagement portion 13 and the engagement piece 14. Thereafter, when the operating rod 25 of the rod expansion / contraction mechanism 23 is shortened, the piston rod 3 extends to the maximum length position by the gas pressure. Further, the operating rod 25 is shortened, the engagement head 26 is separated from the piston rod 3, the holding by the holding mechanism 22 is released, and the shock absorber main body 1 </ b> A is removed from the rod telescopic device 20.

Then, a bushing is press-fitted into the mounting eye 10 of the shock absorber main body 1A, and an inspection process for performing necessary inspections such as measurement of gas repulsive force and measurement of damping force is performed.
The gas reaction force is measured by slightly shrinking the piston rod and measuring the load at that time. The damping force measurement may be performed using various known damping force testers. Although all inspections are desirably performed at this completion stage, if necessary, the damping force may be measured immediately after the assembly process, and only the gas reaction force may be performed at this stage.

  Thereafter, a re-shortening step for shortening and locking the piston rod 3 again and a dust cover mounting step for attaching the dust cover 8 are performed as follows. As shown in FIG. 7B, the shock absorber main body 1A in which the piston rod 3 is in the extended state is set on the rod telescopic device 20 and held in an upright state by the holding mechanism 22, and dust is discharged from the tip end side of the piston rod 3. Cover the cover 8 and place the upper end on the cap member 7. In this state, the air cylinder 24 of the rod expansion / contraction mechanism 23 is operated, the operation rod 25 is extended, the engagement head 26 is put on the tip of the piston rod 9 of the shock absorber main body 1A, and the claw portion 29 is attached to the cap member 7. While being engaged with the window portion 15, the dust cover 8 is pressed by the flange portion 28 of the engagement head 26 to press fit the cap member 7, and the piston rod 3 is shortened to the minimum length position. The shock absorber main body 1A is appropriately rotated by the holding mechanism 22 so that the window portion 15 of the cap member 7 and the claw portion 29 of the engagement head 26 can be engaged, and these phases are matched.

  In this state, the cylinder portion 2 is rotated by the holding mechanism 22 so that the engaging portion 13 and the engaging piece 14 are engaged, and the piston rod 3 is locked at the minimum length position. Thereafter, the operating rod 25 is shortened, the engagement head 26 is separated from the piston rod 3, the holding by the holding mechanism 22 is released, and the hydraulic shock absorber 1 is connected to the rod telescopic device as shown in FIG. Remove from 20. In this way, it is possible to obtain the hydraulic shock absorber 1 that is painted and completed with the dust cover 8 attached thereto and the piston rod 3 is locked at the minimum length position.

In the above embodiment, the case where the present invention is applied to a hydraulic shock absorber has been described. However, the present invention is also applied to a cylinder device in which a rod protrudes from a cylinder portion such as a hydraulic cylinder or a gas spring. The same can be applied.
In the above-described embodiment, the piston rod 3 is locked at the minimum length position. However, this does not necessarily mean that the piston rod 3 is most inserted into the cylinder. As long as the piston rod is locked at a position shorter than the most shortened state when the cylinder device is used, the oil seal 5 can be coated with the paint even when the piston rod 3 is coated. The effect that it does not hurt can be acquired.

  DESCRIPTION OF SYMBOLS 1 Hydraulic buffer (cylinder apparatus), 3 Piston rod (rod), 7 Cap member, 11 Locking mechanism (locking means)

Claims (6)

A cylinder device comprising: a cylinder filled with fluid; a rod projecting from one end of the cylinder so as to extend and contract; and a lock means for restricting movement of the rod relative to the cylinder in a shortened state. A manufacturing method comprising:
An assembly method for assembling the cylinder device, and a painting step for performing painting in a state where movement of the rod in the extending direction is restricted by the locking means. 2. The method of manufacturing a cylinder device according to claim 1, wherein the lock unit restricts movement of the rod in the extending direction with respect to the cylinder in a state where the rod is in a minimum length position. The cylinder device manufacturing method according to claim 1, wherein the cylinder device has a flange portion that extends in a radial direction on a protruding side of the rod. The locking means includes a cylinder side engaging portion provided at one end of the cylinder, and a flange side engaging portion provided at the flange portion and engaged with the cylinder side engaging portion. The manufacturing method of the cylinder apparatus of Claim 3. 5. The method for manufacturing a cylinder device according to claim 3, further comprising a dust cover attaching step of attaching a cylindrical dust cover that covers the rod to the flange portion after the painting step. After the coating step, a releasing step for releasing the restriction on the movement of the rod in the extension direction, an inspection step for inspecting the cylinder device, and a shortening step for shortening the rod and restricting the movement in the extension direction again. The method for manufacturing a cylinder device according to claim 3 or 4, wherein in the re-shortening step, the dust cover is attached to the flange portion.

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