JPH0447461Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to a shock absorber that controls damping force depending on the stroke of a piston.

(Prior Art) As this type of buffer, one shown in FIG. 2 has been known in the past.

The shock absorber shown in FIG. 3 is provided with a cylinder 1 and an inner tube 2, and an oil reservoir chamber 3 is formed between the cylinder 1 and the inner tube 2.

A piston 4 is slidably installed inside the inner tube 2, and a rod 5 of the piston 4 is made hollow. A hollow pipe 7 is erected on a base member 6 provided at the lower end of the inner tube 2, and an auxiliary piston portion 8 formed at the tip of the hollow pipe 7 is made to face inside the rod 5.

Further, the piston 4 is also provided with a seal member 9 that slides into contact with the hollow pipe 7, and a control pressure chamber 10 is formed between the seal member 9 and the auxiliary piston portion 8.

When the piston 4 rises from the illustrated state, the hydraulic oil in the rod side chamber 11 flows out into the bottom side chamber 12 via the orifice 4a formed in the piston 4, but the excess flow flows through the next oil passage. The water flows to the bottom side chamber 12 via the water. That is, Rod5
Flows into the bottom side chamber 12 via the communication hole 13 formed in → control pressure chamber 10 → damping orifices 14, 15 formed in the hollow pipe 7 → hollow pipe 7 → damping port 16 formed at the lower end of this hollow pipe 7 .

When the piston 4 further rises, the lower damping port 15 is closed by the seal member 9, so that the hydraulic oil that has flowed into the control pressure chamber 10 passes only through the upper damping port 14 and enters the hollow pipe 7. flows to Therefore, when the lower damping port 15 is closed, the damping force is greater than when it is open.

As mentioned above, the effective opening area of the damping port is controlled depending on the moving position of the piston 4, that is, its stroke, so the damping force is controlled depending on the stroke of the shock absorber. .

(Problems to be Solved by the Present Invention) In the conventional shock absorber as described above, the sliding resistance between the auxiliary piston part 8 and the seal member 9 becomes large, and the responsiveness deteriorates accordingly. There was a problem in that the hydraulic oil became contaminated due to wear and other factors, deteriorating the performance of the shock absorber.

In addition, in order to reduce the above-mentioned sliding resistance, it is possible to provide an appropriate clearance in the auxiliary piston section 8 and the seal member 9, but in this case, oil leakage from the control pressure chamber 10, etc. Problems such as damping force characteristics becoming inconsistent occur.

The object of this invention is to provide a shock absorber in which the action of the damping force adjustment mechanism does not affect the damping characteristics.

(Means for solving the problem) In order to achieve the above object, this invention uses a damping force generating valve that discharges hydraulic oil in a chamber that contracts according to the compression stroke of the piston into a tank, and a compression force of a suspension spring. A detection spring formed in the shape of a deflectable plate, a transmission plate interposed between these suspension springs and the detection spring, and a transmission plate that comes into contact with the transmission plate and moves according to the amount of deflection of this detection spring, and the above-mentioned damping force is The damping force adjusting mechanism is provided with a control rod that increases the throttle resistance of the generating valve, and this damping force adjusting device is installed in a buffer installed between the cylinder and the tank.

(Operation of the present invention) The detection spring is deflected according to the spring force when the suspension spring is compressed, that is, the stroke of the piston, and the throttle resistance of the damping force generating valve is controlled according to the amount of deflection of the detection spring. Therefore, the damping force characteristics are controlled depending on the stroke of the shock absorber.

(Effects of the present invention) As mentioned above, since the throttling resistance of the damping force generating valve is adjusted by the amount of deflection of the suspension spring, there is no sliding contact part as in the conventional method, and the damping force characteristics is constant.

Moreover, since the detection spring is formed into a dish shape, the amount of deflection of the detection spring corresponding to the amount of compression of the suspension spring is small, and the amount of movement of the control rod that adjusts the damping force is accordingly reduced, and the damping force adjustment mechanism The department becomes smaller.

In addition, since this damping force adjustment mechanism is provided between the cylinder and the tank, for example, if this shock absorber is used on a two-wheeled vehicle, even if the vehicle falls over, the damping force adjustment mechanism will be protected. .

(Embodiment of the present invention) In the embodiment shown in FIGS. 1 and 2, a piston 17 is slidably installed inside the cylinder S, and the piston 17 moves the inside of the cylinder S into a rod side chamber 18 and a bottom side chamber. It is divided into 19 sections.

Then, the rod 20 provided on the piston 17
While guiding the cylinder S to the bearing 21,
It is made to protrude outward.

A flow path 22 is communicated with the bottom side chamber 19, and this flow path 22 communicates with the tank T via the damping force adjustment mechanism A. This damping force adjustment mechanism A moves according to a damping force generation valve v, a detection spring b that is deflected by the spring force when the suspension spring 24 is compressed, and the amount of deflection of this detection spring b,
The control rod 1 increases the set pressure, that is, the throttle resistance, of the damping force generating valve v, and their individual configurations are as follows.

That is, the damping force generating valve v is connected to the cylinder S.
A valve case 26 is provided at the connecting portion 25 connecting the tank T and the valve case 26, and a port 28 of a seat member 27 provided in the valve case 26 is communicated with the flow path 22, and the opening of the port 28 is controlled by a poppet 29. I try to do that.

When the damping force generating valve v opens, the flow path 22 communicates with the tank T via the relay chamber 23 and the oil passage hole 23a.

Note that the reference numeral t in the figure is a check valve provided in the sheet member 27, which allows only flow from the relay chamber 23 to the flow path 22 and blocks flow from the flow path 22 to the relay chamber 23.

Further, one end of the control rod l is exposed to the valve case 26, and this control rod l
and a control spring 30 between the poppet 29 and the poppet 29.
is interposed.

Furthermore, the control rod 1 is provided with a return spring 31.
The return spring 31 is connected to a step 32 formed on the valve case 26 and the control rod 1.
The flange portion 33 is interposed between the flange portion 33 and the casing 32 .

The control rod 1 as described above is slidably supported by a bearing 34, and has its other end protruding outward from the connecting portion 25, and a transmission plate 35 is brought into contact with the protruding end.

The transmission plate 35 is connected to the suspension spring 24
It is made to be able to slide freely on the cylindrical portion 36a of the spring receiver 36, and to cover an annular recess 36b formed in the spring receiver 36.

A dish-shaped detection spring b is provided in the annular recess 36b of the spring receiver 36, and normally the transmission plate 35 is kept in a slightly pushed-up state.

As a result, the piston 17 descends and the pressure in the bottom side chamber 19 rises, and the pressure increases with the damping force generating valve v.
When the pressure exceeds the set pressure, the generating valve v opens and the hydraulic oil flows out to the tank T via the port 28 → poppet 29 → relay chamber 23 → oil passage hole 23a. When passing through v, the desired damping force is exerted.

The set pressure of this damping force generating valve v is determined depending on the stroke of the piston 17,
The principle is as follows.

That is, when the piston 17 descends, the suspension spring 24 is compressed, and the spring force at that time acts on the detection spring b via the transmission plate 35, causing the detection spring b to bend in the direction of flattening it. Let it happen. Therefore, the transmission plate 35 descends against the detection spring b, pushing down the control rod l.

When the control rod l moves as described above, the control spring 30 is compressed and its spring force increases, and the set pressure of the damping force generating valve v increases accordingly.

That is, in this embodiment, the detection spring b detects the stroke of the piston by converting it into the spring force of the suspension spring 24, and
Control spring 30 according to the detected spring force
It is designed to control.

Furthermore, when the piston 17 rises, the hydraulic oil in the tank T flows from the oil passage hole 23a to the relay chamber 23 to
The bottom side chamber 19 via the check valve t flow path 22
leaks into

The damping force adjustment mechanism A as described above is provided at the connecting part 25 that connects the cylinder S and the tank T as shown in FIG. Damping force adjustment mechanism A is located below the upper end of tank T.
For example, if the shock absorber is used in a two-wheeled vehicle, the damping force adjustment mechanism A will be protected even if the vehicle falls over.

[Brief explanation of the drawing]

Figures 1 and 2 show an embodiment of this invention, with Figure 1 being a sectional view and Figure 2 being a plan view of the main parts.
FIG. 3 is a sectional view of a conventional shock absorber. S...Cylinder, 17...Piston, 18...
Rod side chamber, 19... Bottom side chamber, T... Tank, 24... Suspension spring, A... Damping force adjustment mechanism, v... Damping force generation valve, b... Detection spring, l... Control rod.

Claims (1)

[Scope of utility model registration request] a damping force generating valve that causes hydraulic oil in a chamber that contracts in accordance with the compression stroke of the piston to flow out into a tank;
A detection spring formed in a dish shape that deflects due to the compression force of the suspension spring, a transmission plate interposed between these suspension springs and the detection spring, and a transmission plate that is in contact with the transmission plate and depending on the amount of deflection of the detection spring. A damping force adjusting mechanism comprising a control rod that moves and increases the throttle resistance of the damping force generating valve, and the damping force adjusting device is installed between the cylinder and the tank.