JP2929215B2 - Hydraulic shock absorber - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a double-cylinder hydraulic shock absorber used for a vehicle suspension.

(Prior Art) Generally, a hydraulic shock absorber that generates a large damping force instead of a hydraulic shock absorber that is provided as a standard is replaced and mounted in a vehicle for motor sports such as a race.

By the way, in a normal hydraulic shock absorber, the larger the amount of the oil liquid that flows when the damping force is generated, the larger the damping force having stable characteristics can be obtained without being affected by the dimensional accuracy of the parts. Therefore, in order to increase the piston diameter, the hydraulic shock absorber which is replaced and mounted on a motor sports vehicle has a larger shock absorber main body than a standard hydraulic shock absorber (size increase). For this reason, the outer diameter of the shock absorber main body becomes large and cannot be fixed to a knuckle or the like on the wheel side as it is, and as shown in FIG. Another attachment member 3 is connected by welding. The mounting member 3 supports the ends of the outer cylinder 1a and the inner cylinder 1b.
The attachment member 3 is formed to have an outer diameter that can be fixed to a knuckle (not shown) by processing a solid metal material by cutting.

(Problems to be Solved by the Invention) However, the above-mentioned conventional hydraulic shock absorber has the following problems.

Although it is desired to reduce the weight of the racing vehicle, the weight of the hydraulic shock absorber increases because the mounting member 3 made of a solid metal material is connected to the shock absorber main body 1, and the entire vehicle becomes heavier. There was a problem of doing it.

In addition, since the shock absorber main body and the mounting member are connected by welding at an intermediate portion of the hydraulic shock absorber where the bending moment becomes large, there is a problem that sufficient reliability in strength cannot be obtained.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a replacement hydraulic shock absorber which can suppress an increase in weight and is reliable in terms of strength.

(Means for Solving the Problems) A hydraulic shock absorber according to the present invention comprises a shock absorber main body composed of an outer cylinder and an inner cylinder, a piston slidably fitted in the inner cylinder, and one end connected to the piston. A piston rod having the other end protruding outside from an end of the shock absorber main body, wherein an outer cylinder is provided at an end of the shock absorber main body opposite to a side where the piston rod protrudes. Forming a squeezed outer cylinder small-diameter portion, and corresponding to the outer cylinder small-diameter portion, the inner cylinder is provided with an inner cylinder small-diameter portion with a narrowed end at which the piston does not slide. It is.

(Operation) According to the above configuration, the outer cylinder small-diameter portion formed by squeezing one end of the outer cylinder is used as a portion to be attached to a knuckle or the like on the wheel side, so that the weight does not increase significantly. Since no welding or the like is performed, the strength against the bending moment does not decrease. Also, even if the outer cylinder is narrowed to form the outer cylinder small-diameter portion, the portion of the inner cylinder where the corresponding piston does not slide is squeezed to have a small diameter so that the end of the inner cylinder is supported by the outer cylinder. The inner diameter of the sliding part can be freely set to be large.

(Example) Next, an example of a hydraulic shock absorber of the present invention will be described with reference to the drawings. FIG. 1 shows a double-cylinder hydraulic shock absorber according to a first embodiment of the present invention, which is mounted in place of a standard hydraulic shock absorber provided in a vehicle.

The shock absorber main body 4 is composed of an inner cylinder 5 and an outer cylinder 6, and a piston 7 is slidably fitted in the inner cylinder 5. One end of a piston rod 8 is connected to the piston 7, and the other end of the piston rod 8 projects outside from an end of the shock absorber main body 4 through a rod guide 9 and a seal member 10.

The inner cylinder 5 and the outer cylinder 6 of the shock absorber main body 4 are larger in diameter than the inner cylinder and the outer cylinder of the standard hydraulic shock absorber in order to set the piston diameter large. 6a are formed. The outer cylinder 6 is formed with an outer cylinder small diameter portion 6b having the same outer diameter as a standard hydraulic shock absorber so that the side opposite to the side from which the piston rod 8 protrudes is narrowed and can be fixed to a knuckle on the wheel side (not shown). . The inner cylinder 5 is also the outer cylinder small diameter section 6b.
The end of the piston 7 where the piston 7 does not slide is narrowed to form an inner cylinder small diameter portion 5b. The inner cylinder small diameter portion 5b is fixed to the bottom side of the outer cylinder 6 via a base member 18 described later.

The piston 7 has an extension-side communication passage 1 communicating the two chambers 11 and 12 in the inner cylinder 5 partitioned by the piston 7.
3 and a contraction side communication passage 14 are formed, and damping force is generated on both end surfaces of the piston 7 by controlling the flow of the oil liquid in the communication passages 13 and 14 generated by the movement of the piston 7. An extension-side damping force generating mechanism 15 and a contraction-side damping force generating mechanism 16 composed of disk valves are arranged, respectively.

In addition, the end of the inner cylinder small diameter portion 5b of the inner cylinder 5 has the inside of the inner cylinder 5,
A base member 18 is provided for partitioning the reservoir chamber 17 between the inner cylinder 5 and the outer cylinder 6. The base member 18 has a compression-side communication passage 19 and a passage communicating the interior of the inner cylinder 5 and the reservoir chamber 17. 20 are formed. The base member 18 has a piston 7
A damping force generating mechanism 21 composed of a disc valve for controlling the flow of the oil liquid in the contraction side communication passage 19 generated by the movement during the contraction stroke to generate a damping force, and the reservoir chamber 17 through the passage 20 To allow the oil liquid to flow into the inner cylinder 5 from the
A check valve 22 for regulating the flow in the reverse direction is provided. The reservoir chamber 17 is filled with a low-pressure gas 23 to compensate for a change in the volume of the oil liquid in the inner cylinder 5 when the piston rod 8 enters the inner cylinder 5.

A spring seat 24 for supporting one end of a suspension spring (not shown) is provided on the outer periphery of the large diameter portion 6a of the outer cylinder 6.
Are fixed by welding, and a bolt groove 6c for fixing with a knuckle on the wheel side is formed in the outer cylinder of the outer cylinder small diameter portion 6b. Further, a knuckle stopper 25 for positioning the knuckle is fixed to the outer periphery of the outer cylinder small diameter portion 6b.

 The operation of the hydraulic shock absorber having the above configuration will be described.

Since the outer cylinder small-diameter portion 6b of the outer cylinder 6, which is a mounting portion with the knuckle on the wheel side, is formed integrally with the outer cylinder 6, the weight of the outer cylinder 6 is smaller than that using a conventional separate mounting member. A significant reduction can be achieved, and sufficient strength against bending moment can be ensured. Also, an inner cylinder small diameter portion 5b is formed in the inner cylinder 5 corresponding to the outer cylinder small diameter portion 6b, and the inner cylinder small diameter portion is formed.
Since the end of 5b is fixed to the bombout side of the outer cylinder 6, the piston 7
The diameter of the large diameter portion 5a of the inner cylinder on which the piston slides can be increased, and the piston diameter can be freely set.

Further, when the piston 7 of the hydraulic shock absorber slides greatly during traveling on a rough road or the like, there is a possibility that the gas 23 in the reservoir chamber 17 may be caught in the oil liquid and enter the inner cylinder 26. Since the position for communicating the inside of the inner cylinder 5 and the inside of the reservoir chamber 17 with respect to the shock absorber (shown in FIG. 4) is provided below, the amount of gas entering the inner cylinder 6 is reduced.

 Here, the operation of the hydraulic shock absorber will be schematically described.

During the extension stroke, the hydraulic fluid flowing through the extension-side communication passage 13 of the piston 7 is controlled by the extension-side damping force generating mechanism 15 to obtain a damping force, and during the contraction stroke, the contraction-side communication passage 14
The damping force is generated by controlling the oil liquid flowing through the contraction side communication passage 19 of the base member 18 by the contraction side damping force generation mechanisms 16 and 21. At this time, in the compression side communication passage 19 of the base member 18, the oil liquid of the volume that the piston rod 8 has penetrated into the inner cylinder 5 flows toward the reservoir chamber 17, and this flows through the compression side damping force generation mechanism 21. Controls.

Next, a second embodiment of the present invention will be described with reference to FIG. The second embodiment differs from the first embodiment only in the structure of the inner cylinder. The inner cylinder 26 is composed of a large-diameter first inner cylinder (inner cylinder large-diameter portion) 26a and a small-diameter second inner cylinder. A first inner cylinder 26a and a second inner cylinder 26b are connected by an annular connecting member 27. The other configuration is the same as that of the first embodiment, so that the same reference numerals are given and the description is omitted. Since the operation of this embodiment is the same as that of the first embodiment, the description is omitted.

Next, a third embodiment of the present invention will be described with reference to FIG. This third embodiment differs from the second embodiment in that
The contraction side damping force generating mechanism and the check valve provided on the base member 18 are provided on a connecting member 27 for connecting the first inner cylinder 26a and the second inner cylinder 26b. That is, the connecting member 27 vertically separates the chamber 12 in the inner cylinder 26 into a chamber A and a chamber B, and the connecting member 27 is provided with a contraction side communication passage 28 and a passage 29,
Further, the contraction side damping force generating mechanism 30 for controlling the oil liquid flowing through the contraction side communication passage 28 to generate the damping force during the contraction stroke of the connecting member 27 and the oil liquid only from the lower chamber B to the upper chamber A. And a check valve 31 that allows the flow of the fluid.

According to this configuration, the same operation as that of the first embodiment is obtained, and the following specific operation is also performed.

If the piston of the hydraulic shock absorber slides greatly during traveling on a rough road or the like, there is a possibility that the gas 23 in the reservoir chamber 17 may be caught and enter the inner cylinder 26. For this reason, when the damping force generating mechanism 21 is disposed on the base member 18 as in the first and second embodiments, the damping force generated by the entrained gas causes a large disturbance to improve the damping force characteristics. There is a possibility that it will worsen. However, as in the present embodiment, the connecting member 27
If the damping force generating mechanism 30 is provided at the place, the entrained gas is returned from the room B to the reservoir chamber 17 before reaching the damping force generating mechanism 30 provided in the connecting member 27, so that the gas 23 A stable damping force characteristic can be obtained without being affected.

(Effects of the Invention) As described in detail above, the present invention narrows the outer cylinder to the side opposite to the side where the piston rod protrudes in the shock absorber main body to form an outer cylinder small diameter portion, and attaches the outer cylinder to a knuckle or the like on the wheel side. As a result, the weight can be significantly reduced as compared with the conventional mounting member, and the shock absorber body and the small diameter part that is the mounting part are integrated to ensure sufficient strength against bending moment. can do. In addition, by providing the inner cylinder small diameter portion at the end where the piston of the inner cylinder does not slide, corresponding to the outer cylinder small diameter portion, the diameter of the part where the piston slides can be increased, and the piston diameter can be set freely. can do.

Therefore, an optimal replacement hydraulic shock absorber can be provided as desired.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a first embodiment of a hydraulic shock absorber of the present invention, FIG. 2 is a longitudinal sectional view showing a second embodiment of the hydraulic shock absorber of the present invention, and FIG. FIG. 4 is a longitudinal sectional view showing a third embodiment of the hydraulic shock absorber, and FIG. 4 is a longitudinal sectional view showing an example of a conventional replacement hydraulic shock absorber. 4 ... shock absorber main body, 5 ... inner cylinder 5a ... inner cylinder small diameter part, 6 ... outer cylinder 6a ... outer cylinder small diameter part, 7 ... piston 8 ... piston rod

Claims (1)

(57) [Claims] A hydraulic shock absorber main body comprising an outer cylinder and an inner cylinder;
A hydraulic shock absorber comprising a piston slidably fitted in the inner cylinder, and a piston rod having one end connected to the piston and the other end protruding outside from the other end of the hydraulic shock absorber main body. Forming an outer cylinder small-diameter portion in which an outer cylinder is narrowed at an end of the shock absorber body opposite to a side on which the piston rod projects,
A hydraulic shock absorber characterized in that the inner cylinder is provided with an inner cylinder small-diameter portion in which an end at which the piston does not slide is narrowed, corresponding to the outer cylinder small-diameter portion.