JPS6143211B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a spring load adjusting device for a hydraulic shock absorber that supports a rear wheel of a motorcycle or a wheel of a four-wheel vehicle in a damping manner.

This type of hydraulic shock absorber slides inside a cylinder and pulls a piston rod equipped with a damping force generating mechanism upwards into the cylinder, between a spring support fixed on the piston rod side and a spring support provided on the outer periphery of the cylinder. It is constructed with a coil spring interposed between the wheels, and is designed to reduce the impact that occurs in the vertical direction of the wheel.

Therefore, vehicle height adjustment has been widely used since the structure for adjusting the spring load of this hydraulic shock absorber is simple. However, on the other hand, there is a problem that the work is not easy and requires a considerable amount of manpower and time, and furthermore, adjustment cannot be performed steplessly. Therefore, on January 28, 1981, the applicant proposed a device for adjusting the spring load of the rear compression unit in order to solve the above problem, but the position of the plug for the pipe communicating with the pressure chamber was not free to rotate. Because of this, it was thought that the position could change due to vibrations while driving, which caused problems from a safety standpoint.

The present invention proposes a spring load adjustment device for a hydraulic shock absorber with the purpose of solving the above-mentioned problem.The present invention proposes a spring load adjustment device for a hydraulic shock absorber. The flange of the guide is fitted and fixed onto the pipe, the flange of the adjuster is slidable around the outer periphery of the pipe, and the upper surface of the flange supports the lower end of the coil spring. The pipe, the guide, and the adjuster constitute a pressure chamber, and the collar of the adjuster is provided with a guide wall extending upward, and the pipe is inserted into the cut groove provided in the guide wall extending upward. A stopper fixed to the outer periphery is loosely inserted so that it can move forward and backward, and the pipe having the above structure is fitted onto the cylinder in a fixed position so as not to rotate, and the pressure chamber is connected to the external sub-tank pressure chamber with variable volume by a plug and a pipe. When communicating through a flexible pipe, rotation of the adjuster relative to the pipe is restricted to prevent the plug position from rotating. An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a sectional view showing an embodiment of the spring load adjustment device for a hydraulic shock absorber according to the present invention, and FIG. 2 is a side view of the main parts of FIG. 1. In the figure, 1 is a cylinder, 2 is a piston, and 3 is a Piston rod, 4 and 5 are mounting brackets,
6 is a spring receiver fixedly installed on the piston rod 3 side. Pipe 7 on the outer periphery of cylinder 1 and in place
be fitted externally and installed so as to at least restrict rotation. Of course, it may be fixed by welding, etc., but as shown in the figure, a notch 8 (see Figure 2) is provided at the bottom of the pipe 7.
It is preferable to provide a notch 8 and restrict the lower limit and rotation of the notch 8 by a stopper 9 fixed to the outer periphery of the cylinder 1 so that the pipe 7 can be removed. A guide 10 having an L-shaped cross section is fitted onto the outer periphery of the lower part of the pipe 7, forming a tubular gap above, and the lower end of the guide 10 is fixed with a circlip. Reference numeral 11 denotes an adjuster, the upper part of which is shaped like a spring holder to support the lower end of the coil spring 12 and is slidably fitted around the outer periphery of the pipe 7, and the lower part is slidably fitted around the outer periphery of the guide 10. It is formed and arranged to fit. A pressure chamber 13 (see FIG. 1) is formed by the guide 10, adjuster 11, and pipe 7.
5 and 16 to maintain airtightness. Further, a guide wall 17 extending upward is provided on the collar portion of the adjuster 11. This guide wall 17 is provided with a cut groove 18 extending upward, and a stopper 19 fixed to the outer periphery of the pipe 7 is attached to the cut groove 18 so that the guide wall
The rotation of the adjuster 11 with 7 attached is restricted,
It can move forward and backward only up and down, and the stopper 19 regulates its upper limit. Further, the inside of the pressure chamber 13 is communicated with the inside of the pressure chamber 23 of an external sub-tank 22 via a plug portion 20 formed at a predetermined location of the adjuster 11 and a flexible pipe 21 .

In the spring load adjustment device for a hydraulic shock absorber having such a configuration, when raising the vehicle height, the piston sliding inside the sub-tank 22 is lowered by externally rotating the threaded rod of the piston. Then, pressure oil is introduced into the pressure chamber 13 via the flexible pipe 21 and the plug section 20. Therefore, the pressure chamber 13 expands, the adjuster 11 moves upward and presses the lower end of the coil spring 12, bending the coil spring 12, and a larger spring load than before is obtained, so the vehicle height becomes higher. Therefore, if a desired spring load is obtained, the introduction of pressure oil can be stopped. Although the spring load increases due to the introduction of pressure oil, the stopper 19 prevents the adjuster 11 from coming off, and reaches its maximum when the lower end of the groove 18 of the guide wall 17 contacts the stopper 19.

On the other hand, when lowering the vehicle height, the piston of the sub-tank 22 is raised, and the pressure oil in the pressure chamber 13 is discharged to the sub-tank 22 side. However, due to the restoring force of the coil spring 12, the adjuster 11 is pressed downward and moves, and the spring load is reduced compared to the previous flexed state, so the vehicle height becomes lower. Note that the spring load is at its minimum when the inner surface of the adjuster 11 comes into contact with the upper end surface of the guide 10.

In this case, the rotation of the pipe 7 is restricted by the stopper 9 or by the fixation of the pipe 7 and the cylinder, while the adjuster 11 is controlled by the cut groove 1 of the guide wall 17.
Since rotation with respect to the pipe 7 is restricted by the stopper 8 and the stopper 19, the position of the plug communicating with the pressure chamber 13 does not change from its initial installation position. Further, only the stopper 9 is fixed to the outer periphery of the cylinder 1, and its position is at the bottom of the cylinder, so even if the fixation is done by welding, for example, the cylinder 1
There is little effect on the buffering function of the piston 2 that slides therein. Furthermore, the adjusting device can be assembled separately from the cushioning device, and its performance can therefore be independently tested. Of course, the pipe 7 may be welded to the cylinder 1 at the bottom, and the adjustment device may be fixed after inspection.

As explained in detail above, according to the present invention, the adjustment device is easy to assemble, and furthermore, since the rotation of the adjuster relative to the pipe can be restricted, the position of the plug communicating with the pressure chamber remains unchanged from the initial installation position. , which has a great effect on safety.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the spring load adjusting device of the present invention, and FIG. 2 is a side view of the main part of FIG. 1. 1... Cylinder, 2... Piston, 3... Piston rod, 6... Spring holder, 7... Pipe, 10
... Guide, 11 ... Adjuster, 12 ... Coil spring, 13 ... Pressure chamber, 17 ... Guide wall, 18
... Cut groove, 19 ... Stopper, 20 ... Plug section, 22 ... Sub tank.

Claims (1)

[Claims] 1. In a hydraulic shock absorber for a vehicle in which the spring holder of a coil spring interposed on the outer periphery of a cylinder can be slid up and down by hydraulic pressure, a guide with an L-shaped cross section and an adjuster with a similar L-shaped cross section are installed on the outer periphery of the pipe on its peripheral wall. are arranged so as to be able to freely slide relative to each other, the flange of the guide is externally fitted and fixed to the pipe, the flange of the adjuster is slidable around the outer periphery of the pipe, and the upper surface of the flange is connected to the lower end of the coil spring. The pipe, the guide, and the adjuster constitute a pressure chamber, and the flange of the adjuster is provided with a guide wall extending upward, and the cut groove provided in the guide wall extends upward.
A stopper fixed to the outer periphery of the pipe is loosely inserted so that it can move forward and backward, and the pipe having the above structure is fitted onto the cylinder in a fixed position so as not to rotate, and the pressure chamber is communicated with an external sub-tank pressure chamber having a variable volume. A spring load adjustment device for a hydraulic shock absorber.