JPH0618082Y2 - Hydraulic shock absorber valve structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a valve structure of a hydraulic shock absorber in which a damping force by a valve is not generated for a minute stroke of a piston.

(Prior Art) In a general hydraulic shock absorber, a piston equipped with a valve mechanism is directly fixed to the lower end of the piston rod, so the valve mechanism also operates according to the movement of a minute stroke of the piston rod, and the piston ring It is not preferable in terms of durability and riding comfort.

Therefore, as disclosed in Japanese Utility Model Publication No. 63-30832, an elastic body is interposed between a piston and a seal member, and even if the piston rod moves a minute stroke, it is absorbed by the deformation of the elastic body, and the valve mechanism It is known to have a structure that does not activate.

(Problems to be solved by the invention) As described above, when the elastic body is interposed between the piston and the seal member, the rigidity against the lateral force acting on the shock absorber during cornering etc. decreases, This causes inconsistency of the axis lines of the piston rod and the cylinder, which makes it rather unstable.

(Means for Solving the Problems) In order to solve the above problems, according to the present invention, both sides of a plate valve incorporated in a piston or a bottom valve are supported by valve seats, and one valve seat has a spring in a valve guide. The other valve seat was floatingly supported on the valve body via an elastic body.

(Operation) Since the valve seats above and below the piston are both movable in the axial direction, a minute stroke of the piston does not reach the plate valve that constitutes the valve mechanism. on the other hand,
The valve body directly receives the lateral (radial) force acting on the shock absorber.

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

FIG. 1 is a half sectional view of a hydraulic shock absorber to which a valve structure according to the present invention is applied, and FIGS. 2 and 3 are enlarged views of a main part of FIG.

In the hydraulic shock absorber, an inner tube 2 is arranged in an outer tube 1, and a piston rod 5 is inserted from above via an oil seal 3 provided at an upper end of the outer tube 1 and a rod guide 4 provided at a lower portion thereof. A piston 10 to which the valve structure according to the present invention is applied is fixed to a lower portion of the piston rod 5, and the inside of the inner tube 2 is divided into an upper oil chamber S1 and a lower oil chamber S2 by the piston 10, and the outer tube 1 and the inner tube 2 are also provided. A bottom valve 3 to which the valve structure according to the present invention is also applied at the bottom of the
0 is provided to partition the lower oil chamber S2 and the oil sump chamber S3.

In the piston 10, a collar 11 and a washer 12 are fitted from below onto the outer periphery of the small diameter portion 5a of the piston rod 5, a valve guide 13 is attached to the outer periphery of the collar 11, and a nut 14 screwed to the washer 12 and the small diameter portion 5a. Piston body 1 as a valve body having an oil hole 15a formed between
Holds 5.

An upper valve seat 16 having an oil hole 16a is slidably inserted between the outer periphery of the collar 11 and the valve guide 13, and the upper valve seat 16 is fitted with a spring 17a.
Is pushing downwards by. Further, an annular recess 18 having a diameter larger than the oil hole 15a is formed on the upper surface of the piston body 15, and a lower valve seat 19 having an oil hole 19a formed therein is slidably accommodated in the lower valve seat. Elastic rings 20 and 21 made of rubber or the like, which also function as seal rings, are interposed between the upper surface of the inner diameter portion of the seat 19 and the washer 12, and between the lower surface of the outer diameter portion and the piston body 15, and the lower valve seat 19 is provided. Has a floating support. The outer diameter portion of the lower valve seat 19 becomes an upward rising portion 19b and enters the inside of the valve guide 13, and the plate valve 22 is provided between the upper end of the rising portion 19b and the lower end of the boss portion of the upper valve seat 16. I support you.

Thus, the upper valve seat 16, the plate valve 22, and the lower valve seat 19 are not fixed to the piston 10, do not follow the minute stroke of the piston rod 5, and maintain their positions. That is, the plate valve 22 does not open.

If the stroke is increased, the plate valve 22 opens. That is, when the piston rod 5 moves downward by a predetermined stroke or more, both the plate valve 22 and the upper valve seat 16 move upward, the plate valve 22 and the lower valve seat 19 are separated from each other, and oil flows therethrough, while the piston When the rod 5 moves upward by a predetermined stroke or more, the inner diameter portion of the plate valve 22 bends downward to open the valve.

Further, in the bottom valve 30, a bottom piece 32 as a valve body is fixed between the lower metal 31 and the inner tube 2. Oil hole 32 in bottom piece 32
Mounting holes 32 formed in the center while forming a and 32b
The bed 33 is fixed by c.

Further, an outer end flange portion of a valve guide 34 is sandwiched between the bottom piece 32 and the lower end of the inner tube 2, and an upper valve seat 36 having an oil hole 36a urged downward by a spring 35 in the valve guide 34. Is slidably disposed, and a lower valve seat 37 having an oil hole 37a formed between the outer periphery of the rivet 33 and the inner periphery of the falling portion 32d of the bottom piece 32 is slidably accommodated. Between the upper surface of the inner diameter portion of 37 and the lower surface of the flange portion 33a at the upper end of the rivet 33, and between the lower surface of the outer diameter portion and the bottom piece 32, the same elastic rings 38, 3 as described above.
9, the lower valve seat 37 is floatingly supported, and the plate valve 40 is supported between the lower valve seat 37 and the upper valve seat 36. And
This plate valve 40 also does not follow the minute vertical stroke of the piston rod 5.

(Effects of the Invention) As described above, according to the present invention, the plate valve incorporated in the piston of the shock absorber or the bottom valve is supported by the upper and lower valve seats, and the upper and lower valve seats are moved vertically with respect to the valve body. Since it is movable, the plate valve does not open even if the piston rod makes a minute stroke, such as when the vehicle rides over a small protrusion or runs on a road surface with continuous unevenness. Since the valve seat and the valve escape integrally, a high damping force is not generated for a minute stroke, and riding comfort is improved.

Further, in the present invention, since the valve body such as the piston or the bottom piece receives the lateral force acting on the shock absorber, the rigidity is high and the maneuverability is excellent.

[Brief description of drawings]

FIG. 1 is a half sectional view of a hydraulic shock absorber to which a valve structure according to the present invention is applied, and FIGS. 2 and 3 are enlarged views of a main part of FIG. In the drawings, 1 is an outer tube, 2 is an inner tube, 5 is a piston rod, 10 is a piston, and 16, 36
Is the upper valve seat, 19 and 37 are the lower valve seats,
20, 21, 38, 39 are elastic rings, and 22, 30 are plate valves.

Claims (2)

[Scope of utility model registration request] 1. In a valve structure in which both sides of a plate valve disposed in a valve guide are held by a pair of valve seats, one valve seat of the pair of valve seats has a spring in the valve guide. The valve structure of the hydraulic shock absorber is characterized in that the other valve seat is floatingly supported by the valve body via an elastic body. 2. The hydraulic shock absorber according to claim 1, wherein the elastic body also serves as a seal ring for preventing a leak between an inner diameter portion and an outer diameter portion of the other valve seat and the valve body. Valve structure.