JPH0640342Y2 - Variable damping force type hydraulic shock absorber - Google Patents

Description

TECHNICAL FIELD The present invention relates to a damping force variable hydraulic shock absorber used for a vehicle suspension.

As is well known in the prior art, for example, in a hydraulic shock absorber used for a suspension for an automobile, a piston rod penetrating liquid-tightly from one end of the cylinder inside a cylinder filled with hydraulic fluid. Is inserted so as to be detachable, and a piston having a damping force generating means that divides the inside of the cylinder into two chambers is fixed to one end of the piston rod.

Then, in order to assemble the piston to the piston rod, each component of the piston is mounted on the stud portion at one end of the piston rod, and then the male screw portion formed at the tip side of the stud portion is tightened with the nut mold. The female thread portion of the fitting is screwed in and tightened to fix the entire piston (for example, see Japanese Patent Publication No. 42-17787).

However, in the above hydraulic shock absorber, when assembling the piston to the piston rod as described above, the assembling work and the piston on the stud portion of the piston rod are different. Since the work of mounting the above-mentioned components must be performed in one step, the assembly and transfer work becomes extremely complicated.
As a result, for example, when automating the assembly line, the automation assembly line and the device are inevitably complicated and large in size. Particularly, in the hydraulic shock absorber provided with the damping force varying mechanism, since the entire structure becomes complicated, it is further required to omit the assembly line.

Further, as another conventional example, for example, the invention described in Japanese Patent Laid-Open No. 58-166150 discloses that each component of the piston is fixed to one end of the piston rod by a fastening member. Since the step of assembling each component to the tightening member and the step of tightening the tightening member to the piston rod are separate, the same problem as in the former conventional example is brought about.

Means for Solving the Problems The present invention has been devised in view of the problems of each of the conventional examples described above, and is based on the premise that a damping force variable hydraulic shock absorber is used. And a shaft portion protruding from the upper portion of the retainer, each component of the piston is fitted to the shaft portion, and the shaft portion is hollow at one end of the piston rod through a male screw portion on the outer circumference. It is characterized in that each component of the piston is sandwiched between the retainer and one end of the piston rod by being screwed into an internal thread of the inner periphery of the piston.

Each component of the piston having the action damping force generating means is previously attached to the shaft portion of the tightening member, and the tightening member and the piston component are unitized. After that, if the shaft portion of the tightening member is tightened to the female screw portion at one end of the piston rod via the male screw portion, it becomes possible to simultaneously assemble each component of the piston together with the tightening member to the piston rod. Each component of the piston can be securely and easily assembled to the piston rod.

Embodiment Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an embodiment of a variable damping force type hydraulic shock absorber according to the present invention. That is, in the figure, 1 is a cylinder whose both ends are sealed by a sealing member or a sealing member (not shown) and the inside is filled with hydraulic fluid, and 2 is a piston whose one end 2a is inserted into the cylinder 1 in a removable manner. The rods 3 are fixed to one end 2a of the piston rod 2 through a check valve 4, which is a tightening member, and divide the inside of the cylinder 1 into two chambers, an upper liquid chamber 5 and a lower liquid chamber 6. is there.

The piston rod 2 is formed with a hollow portion 2b in the inner axial direction, and upper and lower two stages having different opening diameters for communicating the hollow portion 2b with the upper liquid chamber 5 are formed on a peripheral wall at a predetermined position above the one end portion 2a. A plurality of side holes 7, 8 are radially provided, and
A female screw portion 9 is formed on the inner peripheral surface of the hollow portion 2b of the one end portion 2a. Further, a cylindrical adjuster 10 is rotatably mounted in the hollow portion 2b, and the adjuster 10 is rotatably driven by a motor (not shown) via a drive rod 11. . Further, an axial hole 12 is formed so as to open toward the lower liquid chamber 6 in the inner axial direction, and the axial hole 12 and the side holes 7 and 8 of the piston rod 2 are respectively formed in the radial direction of the peripheral wall. Communication holes 13 and 14 that selectively communicate with each other are formed.

The piston 3 is disposed at the upper and lower ends of a plurality of expansion side ports 16 and compression side ports 17 penetrating the upper and lower surfaces of the piston body 15, and is connected to the upper liquid chamber 5 and the lower part through the expansion side ports 16 and 17, respectively. Plate valves 18 and 19 on the extension side and the compression side, which are damping force generating means for imparting flow resistance to the working fluid that is displaced and flow between the liquid chamber 6 and the washer 2 on the upper side of the pressure plate valve 19.
It is mainly composed of an annular collar 21 which is arranged via 0. Further, on the outer periphery of the main body 15, the upper liquid chamber 5
A piston ring 22 that seals between the lower liquid chamber 6 and the lower liquid chamber 6 is wound.

On the other hand, the check valve 4 is provided with a substantially large-diameter cylindrical terryner 23 and a shaft portion 24 vertically provided on the retainer 23 and having a central hole 24a communicating with the axial hole 12 in the axial direction. ing. The retainer 23 has a large-diameter opening 23a that communicates with the center hole 24a inside, and is caulked and fixed to the lower peripheral surface of the opening 23a, and has a through-hole 25a in the center and an annular projection on the upper surface. Check seat 25 having valve seat 25b and valve seat 25b
An orifice 26a which is arranged so as to be able to be separated from and seated on the working fluid and which gives a flow resistance to the working fluid and a flow passage 26b which allows the working fluid to flow without resistance.
And a check plate 26 having a check plate
And a spring 27 for urging the valve 26 toward the valve seat 25b. Further, the shaft portion 24 has a length and an outer diameter such that the base end portion 24b can mount all the respective components of the piston 3 at appropriate positions, and the female screw portion 9 is formed on the outer peripheral surface of the tip end portion 24c. A male screw portion 28 to be screwed is formed.

Therefore, according to this embodiment, in order to assemble the piston 3 to the piston rod 2, the constituent parts of the piston 4 are first assembled in advance to the shaft portion 24 of the check valve 4. That is, the washer 29, the extension side plate valve 18, the piston body 15, the pressure side plate valve 19, the washer 20, and the collar 21 are assembled in order from the retainer 23 side.
On the other hand, after inserting the adjuster 10 and the thrust washer 30 into the hollow portion 2b of the piston rod 2, the bush 31 is attached to the one end portion 2a.
Press in from the side and attach the adjuster 10 at an appropriate position. Then, the shaft portion 24 of the check valve 4 in which the piston 3 is assembled to the female screw portion 9 of the piston rod one end portion 2a.
If the male screw portion 28 is screwed on and the retainer 23 is tightened with a predetermined rotational torque, the piston 3 and the check valve 4 can be securely and easily attached to the piston rod 2 as one unit. Therefore, the work of assembling and transporting the piston 3 to the piston rod 2 is simplified. As a result, not only the conventional assembly line can be omitted, but also the automation of the assembly line can be sufficiently coped with and the apparatus can be downsized. Further, as described above, as the retainer 23 is tightened, the base end portion 24 of the shaft portion 24 is
Since a tight fit between b and the inner peripheral surface of the hollow portion 2b can be obtained, a more firmly fixed state of the piston 3 and the check valve 4 can be obtained. Reference numeral 32 in the drawing is a rebound stopper that collides with a guide portion (not shown) of the cylinder 1 during the extension side stroke of the piston rod 2 to regulate the maximum extension side movement, and 33 is a rebound rubber that reduces the impact at the time of the collision. Is.

EFFECTS OF THE INVENTION As is apparent from the above description, according to the damping force variable hydraulic shock absorber of the present invention, in particular, the tightening member is a retainer having a large diameter and the shaft portion protruding from the upper portion of the retainer. And each component of the piston is fitted to the shaft portion, and the shaft portion is screwed to the female screw portion of the inner periphery of the hollow portion of the one end of the piston rod through the male screw portion of the outer periphery, Each component of the piston was sandwiched between the retainer and one end of the piston rod. Therefore, when installing the piston,
The components of the piston can be securely and easily assembled to the piston rod simply by mounting the components in advance on the fastening member and then tightening the fastening member to the female screw. As a result, the assembling and conveying work can be simplified, the existing assembling line can be omitted, the assembling line in the case of automation can be omitted, and the assembling apparatus can be downsized. Further, the cost can be reduced by improving the assembling workability. Moreover, since the nut for assembling each component of the piston to the tightening member is not required unlike the conventional case, the number of parts is reduced,
Manufacturing efficiency can be improved and cost can be reduced.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of a variable damping force type hydraulic shock absorber according to the present invention. 1 ... Cylinder, 2 ... Piston rod, 2a ... One end, 2b ...
Hollow part, 3 ... Piston, 4 ... Check valve (tightening member), 5 ... Upper liquid chamber, 6 ... Lower liquid chamber, 7.8 ... Side hole, 9
… Female screw part, 10… Adjuster, 13 ・ 14… Communication hole, 28… Male screw part, 23… Retainer, 24… Shaft part.

Claims (1)

[Scope of utility model registration request] 1. A cylinder in which hydraulic fluid is filled, a piston rod extending through one end of the cylinder in a sealing manner, and an upper liquid chamber provided inside one end of the piston rod. And a lower liquid chamber, and a piston provided with a damping force generating means for permitting a limited displacement flow of the hydraulic fluid between the two chambers, and a hollow wall of the piston rod is bored in a radial direction. A plurality of side holes having different opening diameters that are provided to connect the upper liquid chamber and the lower liquid chamber to each other, and are rotatably fitted in the hollow portion of the piston rod so that any one of the side holes can be selectively formed on the peripheral wall. A variable damping force type hydraulic shock absorber having an adjuster having a plurality of communication holes communicating with each other and a tightening member for fixing the piston having the damping force generating means to one end of a piston rod. Attach a member with a large diameter retainer and retainer. And a shaft portion projecting from the upper part of the piston, each component of the piston is fitted to the shaft portion, and the shaft portion is inserted into the hollow portion of one end of the piston rod through the male screw portion on the outer periphery. A variable damping force type hydraulic shock absorber, characterized in that each component of the piston is sandwiched between the retainer and one end of the piston rod by being screwed into a female thread portion of the circumference.