JPS6224852Y2 - - Google Patents

Description

[Detailed explanation of the idea] (Industrial application field) This invention relates to a hydraulic shock absorber for two-wheeled vehicles.

Conventional hydraulic shock absorbers used in motorcycles generally have an air chamber and an oil reservoir inside.
The intrusion volume of the piston rod is compensated for by the contraction of the air chamber. In this case, the damping force during compression and extension operation is generated according to the piston speed, and the higher the speed, the higher the damping force becomes. However, normally the damping force does not change depending on the piston position, i.e., the stroke position.

As a result, the following problems arose.

For example, in hydraulic shock absorbers for street vehicles, the damping force is set relatively low because the road surface has small undulations to improve responsiveness.However, when cornering, the vehicle body sinks, and this sinking The required damping force is large in the fully loaded state, so the damping force of the front fork and rear fork is IG.
There is a need to make it smaller in the vicinity, but to make it larger when cornering to improve the vehicle's ground contact.

Hydraulic shock absorbers for off-road vehicles have a large stroke and have large undulations on the road surface, so the damping force during normal driving is also set to be relatively large. However, this damping force also provides resistance to the extension operation from the vicinity of maximum compression, so during the extension operation, the vehicle may pick up bumps on the road surface and bottom out.

Furthermore, in the case of a loaded vehicle, it is necessary to adjust the damping force between empty and loaded vehicles.

(Problems to be solved by the invention) Therefore, in order to solve these problems, as disclosed in Utility Model Application No. 52-146461, the flow path area for damping force generation was It has been proposed to change the value sequentially according to the

However, such a means of sequentially changing the flow path area requires a large amount of man-hours to process, leading to high costs.In addition, since the damping force characteristics in both the expansion and contraction operating regions change simultaneously, It was not possible to independently change the damping characteristics and the compression side operation with the desired damping characteristics. Therefore, even if suitable damping force characteristics are obtained in the compression side operation, there is a problem in that the damping force characteristics are poor in the rebound side operation.

In addition, as disclosed in Utility Model Publication No. 17481, when the piston descends to a certain position, the resistance of the piston-side valve is changed by a spring placed in the cylinder in advance, and the damping force characteristics of the piston are changed. There have also been proposals that change the temperature in the middle of the operating range.

However, since the positioning for changing the damping force characteristics is determined in advance by the length of the spring, there was a problem in that the position could not be adjusted.

(Means for solving the problem) This invention was made in order to solve the problems of the conventional technology. The object of the present invention is to provide a hydraulic shock absorber whose damping force can be freely adjusted.

Therefore, the present invention is a dual-tube type hydraulic shock absorber in which an inner tube is slidably inserted into an outer tube, a cylinder is provided in sliding contact with the inside of the inner tube, and a suspension spring is interposed between the cylinder and the inner tube. , the cylinder is formed with a compression side port that communicates with the lower oil chamber and an expansion side port that communicates with the upper oil chamber, and a cylindrical type that expands or contracts the areas of the expansion side and compression side ports depending on the position inside the cylinder. A slider was inserted freely and this slider was sandwiched between a suspension spring and a detection spring opposing the suspension spring. Further, each of the compression side and expansion side ports was set so that the compression side port would contract and the expansion side port would expand in accordance with the movement of the slider accompanying the compression side operation of the shock absorber. As a result, as the shock absorber is in the compressed position, the compression side damping force increases and the rebound side damping force decreases, and similarly, as the shock absorber is in the extended position, the compression side damping force decreases and the rebound side damping force increases.

(Example) Hereinafter, an example of this invention will be described based on the drawings.

FIG. 1 shows an embodiment of this invention.

First, to explain the configuration, 1 is an outer tube, 2 is an inner tube, 3 is a cylinder, and 4 is an expanded diameter part, and the cylinder 3 slides on the inner circumference of the inner tube 2 via the expanded diameter part 4. A check valve 6 is disposed at the piston portion 2A at the tip of the inner tube 2.

Inside the cylinder 3 fixed to the outer tube 1, a cylindrical slider 17 with a flange is slidably inserted due to the balance between the suspension spring 5 and the detection spring 11. That is, the slider 17 is placed on the opposing surface of the suspension spring 5 and the detection spring 11, which are interposed in series between the inner tube 2 and the cylinder 3.
The flange portion 13 of is clamped.

A compression side port 9 is provided on the circumferential surface of the base portion of the cylinder 3, and an expansion side port 16 is provided on the circumferential surface near the expanded diameter portion 4.

A throttle adjustment hole 18 is provided on the circumferential surface of the slider 17 so that one end is in contact with the expansion side port 16, and the throttle adjustment hole 18 has an elliptical shape in the longitudinal direction. It's getting old. Note that there are more throttle adjustment holes 18 than expansion ports 16, so even if the slider 17 rotates within the cylinder 3, the total opening area of the expansion ports 16 remains the same (see Figure 2). .

On the other hand, the pressure side port 9 is narrowed down as the slider 17 moves downward, increasing the damping force during the pressure side operation.

As for the characteristics of the spring in this embodiment, as shown in FIG. 3, since the initial set loads of both the suspension spring 5 and the detection spring 11 are the same, the composite spring force E acts linearly from the time of setting. Therefore, when the initial setting load of the suspension spring 5 is changed, the spring characteristics are changed in parallel. 7 is an oil reservoir chamber, 12 is an upper oil chamber, 14
24 is a lower oil chamber, and 24 is a spring that absorbs the impact when the inner tube 2 is at its most extended position.

Next, the effect will be explained.

When the inner tube 2 moves to the pressure side, hydraulic oil flows from the contracted lower oil chamber 14 to the oil reservoir chamber 7 through the pressure side port 9 due to an increase in the intrusion volume of the inner tube 2. A portion also flows through the check valve 6 into the enlarged upper oil chamber 12.

In this case, as the amount of penetration of the inner tube 2 increases, the amount of compression of the suspension spring 5 increases, and the detection spring 1
1 gradually deflects, the slider 17 narrows the pressure side port 9, and the damping force in the latter half of the compression side increases.

Next, when the inner tube 2 moves toward the expansion side, the hydraulic oil in the upper oil chamber 12 flows out from the expansion side port 16 and generates a damping force, but when the load applied to the suspension spring 5 decreases, the slider 17 rises and the throttle adjustment hole 18 narrows the expansion side port 16, so the damping force can be significantly increased in the latter half of the expansion side operation.

The damping force on the expansion side and compression side can be adjusted by changing the shape of the throttle adjustment hole 18 of the slider 17 or adjusting the compression side port 9.
By changing the shapes of the elements, they can be set independently of each other.

(Effects of the invention) As explained above, with this invention, the damping force can be freely set on the rebound side and the compression side according to the suspension spring load, and suitable damping force characteristics can be provided according to the request. This effect is produced.

[Brief explanation of drawings]

FIG. 1 is a vertical sectional view of the main part of an embodiment of this invention.
FIG. 2 is a longitudinal sectional view taken along the line GG in FIG. 1, showing the arrangement of the expansion side port of the cylinder and the throttle adjustment hole of the adjuster star, and FIG. 3 is an explanatory diagram showing the characteristics of the spring. DESCRIPTION OF SYMBOLS 1... Outer tube, 2... Inner tube, 3... Cylinder, 4... Expansion part, 5... Suspension spring, 6... Check valve, 7... Oil reservoir chamber, 9...
...Pressure side port, 1...Detection spring, 12...Upper oil chamber, 14...Lower oil chamber, 16...Rebound side port, 1
7...Slider, 18...Aperture adjustment hole.

Claims (1)

[Scope of utility model registration request] In a double-tube hydraulic shock absorber, an inner tube is slidably inserted into an outer tube, a cylinder is provided in sliding contact with the inside of the inner tube, and a suspension spring is interposed between the cylinder and the inner tube. A pressure side port that communicates with the oil chamber and a growth side port that communicates with the upper oil chamber are formed, and a cylindrical slider that changes the opening area of the expansion side and compression side ports depending on its position is installed inside this cylinder. The slider is inserted so as to be freely slidable, and the slider is sandwiched between a suspension spring and a detection spring opposing the suspension spring, and each of the ports is arranged so that the compression side port contracts and the rebound side port decreases in accordance with the movement of the slider accompanying the compression side operation. A hydraulic shock absorber characterized by being set to expand.