JPH0210842Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to an improvement of a hydraulic damper.

(Prior Art) In the case of a hydraulic damper, in order to increase the stroke to some extent, a dust seal that slides on the outer periphery of the rod is made to protrude somewhat from the damper case.

(Problem to be Solved by the Invention) Therefore, in such a hydraulic damper, when the rod is fully compressed, the cap attached to the end of the rod comes into contact with the protrusion of the dust seal from the damper case, causing damage to the dust seal. A problem arises in that the durability of this product decreases.

The present invention has been made to solve the above problems, and its purpose is to provide a hydraulic damper that can effectively protect the dust seal and improve its durability.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides an escape groove for the dust seal on the damper case side end surface of the cap bound to the rod end.

(Function) Therefore, even if the cap comes into contact with the damper case when the hydraulic damper is at maximum compression, the protrusion of the dust seal will fit into the relief groove provided on the end face of the cap.
Since it is not deformed by the cap, it is protected from damage and its durability is improved.

(Example) An example of the present invention will be described below based on the accompanying drawings.

FIG. 1 is a longitudinal sectional view of a hydraulic damper according to the present invention, and FIG. 2 is a partially broken sectional view of the dust seal portion of the hydraulic damper at maximum compression.

In the hydraulic damper 1 shown in Fig. 1, 2 is a damper case, and a thread is cut on the outer periphery of the damper case, and two nuts 3, 3 are screwed together. a plain washer 4 for attaching the damper case 2 to other parts;
4 is being held.

Further, a rod guide 5 is tightly fitted to the inner periphery of one end of the damper case 2 via a seal ring 6, and the rod guide 5 holds one end of an inner cylinder 7 housed inside the damper case 2. There is. The other end of this inner cylinder 7 is held by a valve case 8 that comes into contact with the inner surface of the bottom wall 2a of the damper case 2, and an oil hole 7 is formed in the side wall of the inner cylinder 2 on the rod guide 5 side.
A is drilled. Further, an absorbent material 9 such as a sponge is fitted around the outer periphery of the inner cylinder 7.

Further, the rod guide 5 holds an oil seal 11 that slides on the outer periphery of the rod 10, and a dust seal 12 that also slides on the outer periphery of the rod 10 is held on the outside of this. 12a protrudes a little from the end surface of the damper case 2 as shown in the figure.

Incidentally, the tip of the rod 10 extends through the rod guide 5 into the inner cylinder 7, and a clip 13 for preventing the rod from coming off is fitted onto the outer periphery of the tip. In addition, a cap 14 is connected to the end of the rod 10 outside the damper case 2, and is attached to the end surface of the cap 14 on the side of the damper case 2 to avoid interference with the lip portion 12a of the dust seal 12. Annular relief groove 14
a is formed.

On the other hand, an oil groove 8a is provided on the bottom surface of the valve case 8.
An oil hole 8b is formed in the center of the oil hole 8b. This valve case 8 is provided with a washer 15 held between it and the inner cylinder 7, and a check valve 16 for opening and closing the oil hole 8b is provided in the groove portion 8c of this washer 15. Note that a plurality of notches are provided on the outer circumference of the check valve 16.

Also, the washer 15 has an oil hole 1 in its center.
A spring seat 17 made of a perforated hole 7a is in contact with the spring seat 17, and a coil spring 18 is compressed between this and the tip of the rod 10 as shown.
In addition, the coil spring 18 is attached to the spring seat 1.
It may be applied directly to the washer 15 without using the washer 7.

Therefore, there are oil chambers S1 and S in the damper case 2.
Hydraulic oil is sealed in these oil chambers S1 and S2.

Next, the operation of this hydraulic damper 1 will be explained.

The hydraulic damper 1 is attached to its cap 14 as shown in the figure.
If it moves to the right due to the impact force in the right direction, Rod 10
The rod 10 also moves to the right, and an amount of oil corresponding to the volume that the rod 10 enters into the inner cylinder 7 flows from the oil chamber S1 to the oil chamber S2 side through the oil hole 7a bored in the inner cylinder 7. Absorbent material for the amount of oil volume 9
is compressed. At this time, the hydraulic damper 1 is adjusted based on the flow resistance when the oil passes through the oil hole 7a.
A necessary damping force is generated inside the shaft, and external shocks are effectively absorbed and alleviated.

Therefore, in the most compressed state where the rod 10 reaches its rightward movement limit, even if the end surface of the cap 14 comes into contact with the end surface of the damper case 2 as shown in FIG. 12a
The dust seal 12 is accommodated in the escape groove 14a provided in the cap 14, and is not compressed and deformed and damaged, thereby increasing the durability of the dust seal 12.

Next, when the impact force applied to the cap 14 is released, the rod 10 moves to the left in the figure due to the elastic force of the coil spring 18, and the oil hole 7a, the oil groove 8a, the oil hole 8b, Check valve 16, oil hole 1
Oil is replenished via step 7a.

(Effects of the invention) As is clear from the above explanation, according to the invention, an escape groove for the dust seal is provided on the end face of the damper case side of the cap tied to the rod end, so that when the hydraulic damper is at its maximum compression, the cap Even when the dust seal comes into contact with the case, the protruding portion of the dust seal fits within the relief groove of the cap and is not deformed by the cap, so the dust seal is spared from damage and its durability is improved.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a hydraulic damper according to the present invention, and FIG. 2 is a partially broken sectional view of the dust seal portion of the hydraulic damper at maximum compression. In addition, in the drawing, 1 is a hydraulic damper, 2 is a damper case, 5 is a rod guide, 7 is an inner cylinder, 10 is a rod, 12 is a dust seal, 12a
is a lip portion, and S1 and S2 are oil chambers.

Claims (1)

[Scope of utility model registration request] In a hydraulic damper, a rod is inserted into a damper case, a cap is tied to the outer end of the damper case of the rod, and a dust seal is held in the damper case in sliding contact with the outer periphery of the rod,
A hydraulic damper characterized in that an escape groove for the dust seal is provided on an end surface of the cap on the side of the damper case.