JPH0433474Y2 - - Google Patents

Description

[Detailed explanation of the invention] [Field of industrial application] This invention is a hydraulic system for two-wheeled and four-wheeled vehicles in which a disc valve and a leaf valve are provided on one side of the piston, and these valves generate both expansion and compression damping force. The present invention relates to a damping force generating device for a shock absorber.

[Conventional technology]

In hydraulic shock absorbers for two-wheeled vehicles and four-wheeled vehicles, a damping force generating device is known in which valves are provided on both sides of a piston, and the valves generate expansion and compression damping forces, respectively. However, providing valves on both sides of the piston end face in this manner is disadvantageous in terms of space, requires a large number of parts, and complicates the structure.

For this reason, a damping force generating device having a structure shown in FIG. 4 has been developed in which a valve is provided only on one side of the piston.

In this device, an outer annular sheet 2 with a higher height and an inner annular sheet 3 with a lower height are erected in parallel at the upper end of a piston 1, an annular groove 11 is defined between the two annular sheets 2 and 3, and the annular groove 11 has piston 1
A port 10 provided in is open.

Further, a shim 7 is abutted on the inner seat 3, and the base end of the inner circumference of the leaf valve 5 is abutted on the shim 7, and the outer end side extends into the annular groove 11. or,
A non-return valve 4 having an orifice 12 is brought into contact with the leaf valve 5, and the lower surface of the outer end of the non-return valve 4 is brought into contact with the outer annular seat 2. At this time, the leaf valve 5 faces the port 12. There is.

A non-return spring 6 is interposed between the non-return valve 4 and a valve stopper 8, and the non-return spring 6 presses and holds the base end of the non-return valve 4.

The piston 1 and the valve stopper 8 are inserted into the lower part of the piston rod 9, and the lower end of the piston 1 is tightened with a piston nut or the like.

In this damping force generator, the upper oil chamber 14 is
The oil is throttled by the orifice 12, and flows into the lower oil chamber from the port 10 while bending the leaf valve 5 downward, and at this time, the orifice 12 and the leaf valve 5 generate a rebound damping force.

On the other hand, during compression, the oil flowing out from the port 10 pushes the entire leaf valve 5 and non-return valve 4 upward against the non-return spring 6.
The oil flows from the outer peripheries of these valves 5 and 4 to the upper oil chamber 14.

In this case, the load on the non-return valve 6 is small and the pressure-receiving area of both valves 5, 4 is large, so the valves 5, 4 are lifted significantly, and since the oil resistance is small, almost no compression-side damping force is generated.

[Problem that the invention attempts to solve]

Since the device shown in FIG. 4 is a one-handed valve that generates only a rebound damping force, another valve mechanism such as a base valve is required to generate a compression damping force.

On the other hand, in the device shown in FIG. 4, the lower surface of the non-return valve 4 becomes non-return only when the difference in height between the inner annular seat 3 and the outer annular seat 2 is equal to the sum of the thicknesses of the shim 7 and the leaf valve 5. Since the upper surface of the valve 5 and the seat surface of the outer annular seat 2 can be uniformly abutted without any gaps, the damping force can be obtained at a preset value without leakage from this abutment surface.

However, as shown in Figure 5, two sheets 2 and 3
and the total thickness t of the shim 7 and the leaf valve 5, if h>t, there is a gap δ (= h
-t) occurs, and this gap δ causes a leakage effect on the rebound damping force, particularly in the low speed range, leading to a decrease in the damping force.

Moreover, it is difficult to eliminate this gap δ in terms of component precision control, and if this is achieved, the cost will be high.

Similarly, as shown in FIG.
When the total thickness t of the shims 7 and 7 is larger than the height difference h between the seats 2 and 3 (t>h), the non-return valve 4 does not reliably contact the seat surface of the outer annular seat 2. , a gap δ occurs. In this case as well, leakage occurs, leading to a decrease in damping force, and moreover, it is difficult to manage the tolerance of this gap δ. In other words, in this conventional device, the variation in damping force becomes extremely large for the reasons mentioned above.

Therefore, the purpose of the present invention is to generate both push and pressure damping force using a valve mechanism provided only on one side of the piston, and to create a gap between the valves without having to control dimensional or processing tolerances. First, it is an object of the present invention to provide a damping force generating device for a hydraulic shock absorber that can prevent variations in damping force, such as a decrease in damping force.

[Means for solving problems]

In order to achieve the above object, the structure of the present invention is such that a piston rod is slidably inserted into a cylinder via a piston, and a valve is provided on one side of the piston to generate a damping force. An inner annular sheet and an outer annular sheet of the same height are erected on the end face of the disk, an annular groove facing a port of a piston is defined between the two annular sheets, and an orifice is bored on the two annular sheets. The valves are brought into uniform contact, and the proximal end of the disc valve is clamped and fixed between the inner annular seat and a shim having an outer diameter larger than the inner annular seat, and the leaf valve and the elastic body are inserted into the annular groove. The leaf valve uniformly abuts the disc valve while facing the orifice, and the proximal end of the leaf valve is held between the elastic body and the disc valve, and the load is such that the elastic body does not lift the leaf valve. It is characterized by being constantly energized.

[Effect]

The disc valve uniformly contacts the two annular seats, and the leaf valve is pressed so as to uniformly contact the lower surface of the disc valve, so that no leak occurs during expansion and contraction, and the damping force does not vary.

〔Example〕

An example of implementing the present invention will be described below with reference to FIGS. 1 to 3.

The hydraulic shock absorber 15 is connected to the cylinder 13 and the cylinder 1.
The piston rod 9 is slidably inserted into the cylinder 13 via a piston 16, and the piston 16 defines two upper and lower oil chambers 14 within the cylinder 13. The piston 16 has a port 17 and an annular groove 18 through which the two oil chambers 14 communicate, and the piston 1
A valve 19 facing the port 17 is provided on the upper seat surface of the valve 6, and the valve 19 is bent during expansion and contraction to generate both expansion and compression damping forces.

At the bottom of the piston rod 9 is a valve stopper 2.
0, shim 21, disc valve 22 and piston 1
6 are inserted one after another, and these members are tightened and held by a piston nut or the like screwed onto the stepped portion 28' of the piston rod 9 and the lower end of the piston rod 9.

The inner annular sheet 27 and the outer annular sheet 28 that stand up on the upper end of the piston 16 are formed to have the same height, and an annular groove 18 is formed between these annular sheets 27 and 28.
This annular groove 18 faces the port 17 and the orifice 26 provided in the disc valve 22.

The disc valve 22 has two annular seats 27,
The proximal end of the disc valve 22 is clamped and fixed by the shim 21 and the inner annular seat 27 to form an outer peripheral flexible valve.

A leaf valve 23 guided by the outer periphery of the inner annular seat 27, a support 24, and a disc spring 25 which is an elastic body are sequentially inserted into the annular groove 18, and the disc spring 25 connects the leaf valve 23 via the support 24 to a disc valve. The leaf valve itself is constantly energized so as to contact the lower surface of the leaf valve 22 with a load that will not lift it.

Since the heights of the two annular seats 27 and 28 are the same and the leaf valve 23 is biased upward by the disc spring 25, there is a gap between the disc valve 22 and the two seats 27 and 28 and the disc valve 2.
There is no gap between the valve 2 and the leaf valve 23.

According to the damping force generating device described above, when the damping force generator is extended, the oil in the upper oil chamber 14 flows while being throttled by the orifice 26 as shown in FIG.
It flows into the port 17 while being bent downward, and at this time, a rebound damping force is generated by the action of the orifice 26 and the leaf valve 23.

On the other hand, during compression, the oil flowing out from the port 17 simultaneously bends the leaf valve 23 and disc valve 22 upward, as shown in FIG.
4, and at this time, a compression damping force is generated due to the deflection of the leaf valve 23 and the disc valve 22.

By the way, since the upper surface of the base end side of the disc valve 22 is held down by the shim 21, the amount of lift of the disc valve 22 and the leaf valve 23 during compression can be reduced, which also reduces the movable mass, and as a result, the valve Improves frequency response. Also, the thickness of the shim 21 and the valve stopper 2
The lift amount of the disc valve 22 and the leaf valve 23 can be easily controlled by having an outer diameter of 0. Therefore, the damping force in the low and medium speed range is determined by the thickness of the disc valve 22 and the leaf valve 23 and the outer diameter of the shim 21, and the damping force in the high speed range is determined by the thickness of the shim 21 and the valve stopper 20. Since it is determined by managing the lift amount of the valve outer periphery based on the outer diameter, the compression side damping force can be set over a wide range.

Furthermore, the outer diameter of the shim 21 is the same as that of the leaf valve 23.
The inner diameter of the support 24 is larger than the inner diameter of the support 24, or in other words, the outer diameter of the inner annular seat 27. For this reason, even if the disc spring 25 tries to push up the leaf valve 23 and the disc valve 22, the leaf valve 23 and the disc valve 22 will not be lifted because the shims 21 are arranged facing each other, and the disc valve 22 and the outer annular seat 28 will not be lifted. The accuracy of the damping force can be ensured without creating a gap between the two.

[Effect of idea]

According to the present invention, the following effects can be obtained.

A disc valve and a leaf valve are provided only on one side of the piston, and when the piston is extended, the deflection of the leaf valve generates a rebound damping force, and during compression, the deflection of the leaf valve and disc valve generates a compression damping force. There is no need to install separate expansion and compression valves in separate positions, the number of parts is small, the space for installing the valves is saved, and the structure is compact.

Since one side of the base end of the disc valve is held down by a shim, the amount of deflection and lift of the disc valve and leaf valve can be reduced during compression, which also reduces the movable mass. Improves frequency response.

Since the outer diameter of the shim is larger than the outer diameter of the inner annular seat, even if the disk valve is pushed upward by the elastic body, this disk will not easily bend, and therefore the outer end will not be lifted and the outer annular seat will not be lifted. The accuracy of the damping force can be ensured without creating a gap between the two.

The proximal end of the leaf valve is held between the elastic body and the disc valve, and is constantly energized with a load that prevents the elastic body from lifting, so when it is extended, only the outer peripheral side of the leaf valve flexes, and the flexure allows it to achieve the desired result. Rebound damping force can be obtained.

Since the outer annular seat and the inner annular seat are at the same height, the disc valve uniformly contacts each of these seats, and the leaf valve uniformly contacts the disc valve and is energized by the elastic body. Therefore, there are no gaps between each seat and the disc valve and between the disc valve and the leaf valve, and since there is no leakage, it is possible to prevent variations such as a decrease in damping force.

Even if there is a machining error in the height of the two inner and outer annular seats, if the inner circumference has a negative dimension, there will be no problem because it is clamped and fixed, and even if there is a thickness error in the leaf valve, the elastic material , and no gaps are created.

Because there is no need to manage dimensions and processing tolerances,
Improves workability and reduces costs.

[Brief explanation of the drawing]

1, 2, and 3 are a longitudinal sectional front view showing the main parts of a damping force generating device according to an embodiment of the present invention, and a longitudinal sectional front view showing the operating state, and FIGS. 6
The figure is a longitudinal front view of the longitudinal damping force generator. 13...Cylinder, 16...Piston, 18...
...Annular groove, 21...Shim, 22...Disc valve, 23...Leaf valve, 24...Support,
25...Elastic body, 26...Orifice, 27,2
8...Annular sheet.

Claims (1)

[Claims for Utility Model Registration] (1) In a hydraulic shock absorber in which a piston rod is slidably inserted into a cylinder via a piston, and a valve is provided on one side of the piston to generate damping force, An inner annular seat and an outer annular seat of the same height are erected, an annular groove facing the port of the piston is defined between the two annular seats, and a disc valve with an orifice is bored on the two annular seats. abutting uniformly, the base end side of the disc valve is clamped and fixed by the inner annular seat and a shim having an outer diameter larger than the inner annular seat, and a leaf valve and an elastic body are inserted into the annular groove, The leaf valve uniformly contacts the disc valve while facing the orifice, and the proximal end of the leaf valve is held between the elastic body and the disc valve, and is constantly applied with a load such that the elastic body does not lift. A damping force generating device in a hydraulic shock absorber, characterized in that: (2) A damping force generating device for a hydraulic shock absorber according to claim 1 of the utility model registration claim, wherein the elastic body is a disc spring. (3) A damping force generating device for a hydraulic shock absorber according to claim 1, wherein a support is interposed between the leaf valve and the elastic body.