JPS6230596Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a damping force adjusting device for a shock absorber used in two-wheeled vehicles, four-wheeled vehicles, etc., and particularly to a damping force adjusting device suitable for adjusting damping force on the compression side.

For example, as this type of compression side damping force adjustment device,
The one disclosed in Japanese Patent No. 54-19890 is known.

This is a system in which the shock absorber main body and a gas tank are connected through a communication pipe, and a compression side damping force adjustment device is provided inside the gas tank. This device has the advantage that the compression side damping can be easily adjusted according to the driver's preference and is structurally simple, but it also changes the square-law damping characteristics by adjusting the opening area of the orifice. Therefore, the adjustment range in the high speed range is large, and the adjustment range in the low speed range is small and hardly changes. Therefore, it has not been possible to cope with cases where a high damping force is required in a low speed range depending on road conditions or driver preference.

For example, if the compression side damping force is small on a soft running road, the ground contact will be too good, which may impair steering stability. In this case, if the orifice opening area is made smaller in response to the requirements in the low-speed range, the damping force in the high-speed range will increase, which will cause poor ground contact when landing from a jump, for example, and impair steering stability.

In other words, there is a problem in that it is not possible to perform preferable damping adjustment over the entire speed range simply by adjusting the opening area of the orifice. SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a damping force adjusting device for a shock absorber that allows a desirable compression damping force to be obtained in all speed ranges, both low speed and high speed.

In order to achieve the above object, the structure of the present invention is such that, in a shock absorber in which the liquid chamber of the main body is communicated with the liquid chamber of the tank via a communication member, a passage is provided to communicate the liquid chamber on the main body side and the liquid chamber on the tank side. A hollow rotary valve is rotatably inserted in the middle, and the rotary valve is formed with a mouth end side through hole that opens directly into the passage and a plurality of body side orifices that are selectively opened and have different inner diameters. A proportional valve consisting of a poppet-shaped valve body is inserted into the hollow part of the valve so as to be slidable up and down, and a spring is interposed between the valve body and an adjuster screwed onto the rotary valve so as to be movable up and down. , the valve body is biased by a spring in a direction to close the opening end side passage of the rotary valve.

An embodiment of the present invention will be described below with reference to the drawings.

The hydraulic shock absorber consists of a main body 1 and a tank 2. In the main body 1, a piston rod 4 is slidably inserted into a cylinder 3 via a piston, and two liquid chambers are defined within the cylinder 3 by the piston, and the lower liquid chamber is connected via a hose 5 serving as a communicating member. tank 2
It communicates with the liquid chamber on the side. The main body 1 is interposed between the wheel side and the vehicle body side via an eye 6 on the cylinder side and an eye 7 on the piston rod side. A suspension spring 8 is interposed between the spring seat on the outer periphery of the cylinder and the spring seat on the piston rod side to constantly urge the piston rod 4 in the direction of extension.

The tank 2 includes a tank cylinder 9 and a free piston 1 that is slidably fitted into the tank cylinder 9.
0, a gas chamber 11 and a liquid chamber 12 divided by a free piston 10, and a valve device 13 provided at one end of the tank cylinder 9 and in the middle of a passage leading to the liquid chamber 12 of the main body 1. It consists of

A valve case 14 is screwed onto the end of the tank cylinder 9 on the liquid chamber 12 side, and the valve case 14 has two vertical passages 15 and 16 that open into the liquid chamber 12.
and a lateral passage 17 are provided, the lateral passage 1
7 communicates with the hose 5 via a passage 19 in a thick walled portion 18 that is integral with the tank cylinder 9.

A rotary valve 22 is fitted into the passage 15, and the upper end of the rotary valve 22 is fixed with a stopper 21 such as a snap spring, and an orifice opening into the lateral passage 17 is provided.

That is, a cylindrical rotary valve 22 is rotatably inserted into the passage 15 via a seal, and the rotary valve 22 has one opening end through hole 23 that opens into the passage 15 and a passage 17 in the lateral direction. A plurality of body-side orifices a with different inner diameters that are selectively opened;
b . However, the orifice may be one in which the opening area of one orifice can be sequentially made smaller or larger by rotating the rotary valve of the orifice. A plurality of grooves 24 corresponding to the positions and numbers of orifices a, b...n are provided on the lower outer periphery of the rotary valve 22, and one of the grooves 24 is selectively connected to a detent mechanism consisting of a ball 25 and a spring 26. The mating is adapted to position the selected orifice.

A poppet valve 27 consisting of a poppet-shaped valve body serving as a proportional valve is inserted into the hollow portion of the rotary valve 22 via a piston so as to be vertically slidable and in series with the orifice.
is always urged upward by a lower spring 28 and is usually pushed against the mouth end seat of the passage hole 23, and when pressure is built up in the passage 17, the passage 23 opens against the spring 28.

A rod-shaped adjuster 29 is screwed into the center of the lower part of the rotary valve 22 through a seal so as to be movable up and down.The upper end of this adjuster 29 supports the spring 28, and moves the adjuster 29 either up or down. In particular, the spring characteristics can be adjusted, and by adjusting the spring characteristics, a proportional damping characteristic can be obtained. On the other hand, a check valve 30 is provided in the other passage 16.
is arranged to be openable and closable, and closes when the main body 1 is compressed.
It is designed to open when stretched.

Next, we will discuss the operation.

When the piston rod of main body 1 is compressed, main body 1
The lower liquid chamber is compressed, and a part of the hydraulic oil in this liquid chamber is led to the passage 19 via the hose 5, and then the poppet valve 27 is pushed open through the passage 17 and orifice a, and the hydraulic oil is introduced from the passage 23 and the passage 15. guided to the liquid chamber 12,
The free piston 1 is moved by the hydraulic oil supplied to the liquid chamber 12.
0 moves against the gas pressure in the gas chamber 11. Therefore, the tank 2 compensates for the volume of the intrusion of the piston rod 4. Also, when hydraulic oil leaks into the passage 17, the check valve 30 is pushed up and closes the passage 16.

Therefore, when the hydraulic oil flows out from the passage 17 to the liquid chamber 12, the flow resistance of the orifice a and the poppet valve 2
A damping force on the compression side is generated due to the combination of the flow resistance squeezed at the head of No. 7. The orifices a, b, . . . n provide square-law type characteristics, and in order to obtain the desired riding comfort mainly in the high-speed range, the rotary valve 22 is rotated to select the desired orifice.

On the other hand, the poppet valve 27 has proportional characteristics, so in order to obtain the desired ride comfort mainly in the low speed range, the spring load of the spring 28 can be adjusted by rotating the adjuster 29 with a screwdriver or the like. It is possible to obtain a corresponding damping force.

When the main body 1 is extended, the piston rod 4 is extended, and the lower liquid chamber of the main body 1 is expanded. At this time, the hydraulic oil in the liquid chamber 12 in the tank 2 pushes the check valve 30 from the passage 16 and opens the passage 17 to the passage 19. -Hose 5
to prevent negative pressure in the lower liquid chamber.

As described above, according to the present invention, a rotary valve with a plurality of orifices formed in the middle of the passage is provided, and a proportional valve consisting of a poppet-type valve body is provided within this rotary valve, so that it can be used mainly in high-speed ranges. The damping force can be adjusted by rotating the rotary valve and adjusting the opening area of the orifice, and the damping force in the low speed range can be adjusted by adjusting the load of the spring that biases the proportional valve. As a result, favorable damping force characteristics can be obtained in the entire speed range,
Since the damping force can be adjusted independently in the high-speed range and low-speed range, and the proportional valve is built into the rotary valve, the adjustment mechanism consisting of these valves can be built into one valve case, for example, in series. The hydraulic shock absorber can be made more compact, and repairs can be made by replacing the valve case.
This has advantages such as easy inspection and easy manufacture.

[Brief explanation of the drawing]

The accompanying drawing is a partially longitudinal side view of a shock absorber according to an embodiment of the present invention. 1...Main body, 2...Tank, 5...Communication member,
12...Liquid chamber, 22...Rotary valve, 27...
...Valve body, 28...Spring, a, b...n...
Orifice.

Claims (1)

[Scope of utility model registration request] In a shock absorber that communicates the liquid chamber of the main body with the liquid chamber of the tank via a communication member, a hollow rotary valve is rotatably inserted in the middle of a passage connecting the liquid chamber of the main body and the liquid chamber of the tank, The rotary valve is formed with a mouth-side through hole that opens directly into the passage, and a plurality of body-side orifices that are selectively opened and have different inner diameters, and a poppet-shaped valve body is formed in the hollow part of the rotary valve. A proportional valve is inserted so as to be vertically slidable, and a spring is interposed between the valve body and an adjuster screwed onto the rotary valve so as to be vertically movable. A damping force adjustment device for a shock absorber that is energized in the direction of closing the side hole.