JPS6230337B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a shock absorber equipped with a damping force variable mechanism that operates effectively in both the upper stages of the shock absorber's compression process and extension process.

Traditionally, for example, shock absorbers for motorcycle rear suspensions have been designed to prevent damping force from decreasing due to a drop in the viscosity of the pressurizing oil caused by a rise in the temperature of the pressurizing oil in the cylinder due to the frequent compression and expansion of the piston rod. In order to achieve this, a variable damping force mechanism that operates during either the compression stroke or the extension stroke has been installed. That is, as a damping force variable device during the extension stroke, for example, a leaf valve is provided on the piston,
A rotation adjustment member is provided that forms a bypass passage that opens above and below the piston, and has multiple types of orifices that throttle the amount of liquid that passes through the bypass passage, and that allows oil to pass from above the piston to below. A damping force adjustment mechanism (Japanese Utility Model Publication No. 56-84142) equipped with a check valve that allows only
As illustrated in Fig. 1, a hollow piston rod B has an oil passage for pressurizing oil and a flange provided at the rear of the piston A is attached to a flange portion of the hollow piston rod B, which has a piston A installed at the front and rear ends thereof with a check valve. An oil passage leading to the oil passage of the hollow piston rod b and a check valve that opens during the compression stroke are provided.
A damping force adjustment mechanism is known in which a needle valve c is fitted in a hollow portion so as to be freely advanced and retracted, and an automatic advancing and retracting means is provided for automatically advancing and retracting the needle valve c in accordance with temperature changes.

However, due to manufacturing and mechanical difficulties, there is no shock absorber that is equipped with both of these elements, although each of them is equipped individually, and a shock absorber that is equipped with both of them has been desired.

The inventor of the present invention has made various efforts to obtain a shock absorber equipped with a variable damping force mechanism for both compression and extension strokes, and as a result, one end of the needle valve is made hollow so that the fluid volume can be changed in the oil passage during the extension stroke. The present invention was made based on the discovery that the object could be achieved by providing a separate device.

Hereinafter, one embodiment of the present invention will be described based on the accompanying drawings. FIG. 2 is a sectional view of essential parts showing an embodiment of the variable damping force mechanism of the present invention. In the figure, reference numeral 1 denotes a hollow piston rod, and a piston 5 equipped with an oil passage 2, a check valve 3, and a rebound seat 4 is attached to the tip of the piston rod.
At the rear of the oil passages 6, 6', 6'', a flange portion 9 is integrally protruded and provided with a check valve 8 which is elastically supported in the oil passage 6' by a check valve spring 7 and opens during the compression stroke. Reference numeral 10 denotes a hollow needle valve, which is opened at the open end side of the hollow piston to form an oil passage 11, and is fitted into the hollow portion of the hollow piston rod 1 so as to be able to move forward and backward. The rear of the hollow needle valve 10 is comprised of a push rod A13, a push rod B14, etc. each having an oil chamber 12, and the hollow needle valve 10 is automatically advanced or retracted according to the detection of the built-in temperature sensor, and the oil passage 6, Hollow needle valve 1 for adjusting the amount of oil passing through 6', 6''
0 automatic advance/retreat stages are provided adjacently. 15
is a rebound stopper, which is provided in contact with the flange portion 9, has an oil passage 16 bored therein, and has a check valve 17, which is opened during the extension stroke, elastically supported by a check valve spring 18, and is positioned on the circumference. A steel ball 19 is used to engage a conical groove 20 provided around one circumference of the hollow piston rod. Reference numeral 21 denotes a plug, which is provided in contact with the flange portion 9 via the rebound stopper 15, and is provided with an oil passage 22, and a plurality of plugs bored in the hollow piston rod 1 in various sizes so as to restrict the flow rate. An adjuster sheet 24 with a roughened surface such as grooves is provided on the outside to communicate with one of the seed oil passages 23, and is connected to a plug by a steel ball 25 and a position spring 26. The rebound stopper 21 is engaged with a conical groove 27 formed in the rebound stopper 21 .
28 is a rebound rubber having a rough surface with grooves, etc., and is fitted into a rubber housing 30 fixed to the end of the cylinder 29;
When the hollow piston rod 1 is moved upward in the figure, it joins with the adjuster seat 24, and constitutes a rotary oil passage selection means for selecting the oil passage 23.

Therefore, the flange portion 9, the oil passages 6, 6', 6'',
An automatic temperature control system consisting of an oil passage during the compression stroke consisting of a check valve 8 which is resiliently stopped by a check valve spring 7, a hollow needle valve 10, an automatic extension/retraction means for the hollow needle valve 10, etc. The guarantee mechanism constitutes a damping force variable mechanism during the compression stroke. Also, the plug 21 is connected to the flange portion 9 via the rebound stopper 15.
Check valves 17 are provided in contact with each other and are resiliently stopped by check valve springs 18, respectively.
an oil passage 16 provided with an oil passage 16, and an oil passage 2 communicating with one of the oil passages 23 for flow rate adjustment provided in the hollow piston rod 1.
2 is provided and communicated with the oil passage 11 of the hollow needle valve 10 to constitute an oil passage during the extension stroke, and together with the rotary oil passage selection means constitutes a damping force variable mechanism during the extension stroke.

Since the shock absorber of the present invention is configured in this way, the built-in temperature sensor senses the temperature of the pressurizing oil in the cylinder in response to the operation of the shock absorber, and the automatic advancing/retracting means of the hollow needle valve is activated. When activated, the hollow needle valve 10 is automatically moved forward and backward to open the oil passage 6,
By adjusting the amount of oil flowing through 6' and 6'',
The damping force during the compression stroke is automatically adjusted. In addition, to adjust the damping force during the extension stroke, pull out the hollow piston rod 1 to the right in the figure in advance, and adjust the adjustment seat 24 and the rebound rubber 2.
8 and engage the respective grooves and rotate the hollow piston rod 1 to form an oil passage 23 of an arbitrary size.
This can be done by selecting and configuring the oil passage during the extension stroke.

As described above, the present invention provides a variable compression damping force mechanism that is equipped with a hollow needle valve that moves forward and backward automatically by an automatic forward and backward means, and a hollow piston rod that is provided with a plurality of oil passages of arbitrary sizes. The damping force variable mechanism during extension is provided with a rotary oil path selection means and a separate oil path during the extension stroke, so compression,
It is possible to equip the same shock absorber with a damping force variable mechanism that operates during both extension strokes, and the effect is great.

The variable damping force mechanism during extension provided in the present invention is not only applicable to all shock absorbers having a variable damping force mechanism during compression using a needle valve, but also to other shock absorbers. The mechanism itself is applicable to any buffer. Moreover, it goes without saying that each mechanism of the present invention can be appropriately converted into other means other than this example.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of an essential part of an example of a shock absorber having a conventional needle valve type variable damping force mechanism during compression, and FIG. 2 is a cross-sectional view of a shock absorber having a variable damping force mechanism according to the present invention. FIG. 2 is a cross-sectional view of main parts showing an example. 1...Hollow piston rod, 5...Piston,
6, 6', 6''...Oil passage, 8...Check valve,
9...Flange part, 10...Hollow needle valve, 11, 11'...Oil passage, 12...Oil chamber, 13
...Push rod A, 14...Push rod B, 15...Rebound rubber, 16...Oil path,
17...Check valve, 21...Plug, 22
...Oil passage, 23...Oil passage, 28...Rebound rubber, 29...Cylinder, 30...Rubber housing.

Claims (1)

[Claims] 1. A hollow piston rod 1 equipped with a piston 5 having an oil passage 2 and a check valve 3 at its tip; an oil passage 6 during the compression stroke that is equipped with a check valve 8 that opens during the compression stroke and communicates the upper and lower chambers of the piston;
6', 6'', and a hollow needle valve 10 that is fitted into the hollow part of the hollow piston rod 1 and moves back and forth depending on the oil temperature to adjust the amount of oil flowing through the oil passage. Oil passages 16, 22, 2 during the extension stroke are provided with a check valve 17 that opens during the extension stroke and communicate the upper and lower chambers of the piston.
3, 11', 11, an adjusting seat 24 is provided which engages with the rebound rubber 28 so that one of the plurality of oil passages 23 provided in the hollow piston rod 1 and the oil passage 22 selectively communicate with each other, and rotates with respect to the hollow piston rod. A damping force variable mechanism equipped with a damping force variable mechanism including a damping force variable mechanism during an extension stroke consisting of a plug 21 that can be provided.