JPS5847322Y2 - Shock absorber damping valve - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a damping valve for a hydraulic shock absorber.

General shock absorbers use a damping valve installed on the piston to create resistance to oil flow and generate a predetermined damping force, but so-called double-acting shock absorbers do not use such a damping valve. Since two damping valves are used and they are arranged in opposite directions, it may be difficult to obtain the desired damping effect if the damping effect of one damping valve is affected by the leakage flow in the other valve. .

For example, the damping valve structure shown in FIG. At the same time, leaf valves 8 and 9 are provided on the downstream side of the oil passing through each of these communication holes 6 and 7, so that oil flows through the oil flow holes 6 and 7 as the piston 2 moves. The oil that alternately flows through these flow holes 6 and 7 is given throttling resistance by the leaf valves 8 and 9, and has a structure that produces a predetermined damping force independently on the expansion side and the net side. There is.

However, in this type of damping valve structure, in order to smooth the damping characteristics especially when the movement of the piston 2 is slow, the flow holes 6 are closed even when each leaf valve 8, 9 is not in operation.
, 7 is not completely blocked, and the pilot orifice i
o, 'ii are provided.

Therefore, for example, when the piston 2 moves to the right and oil in the hydraulic chamber 5 passes through the flow hole 6 and a damping force is generated at the leaf valve 8, some of the oil in the hydraulic chamber 5 is A wave flow passes through the orifice 11 and the flow hole 7 in the other leaf valve 9 and flows into the hydraulic chamber 4, making it impossible to obtain the original damping characteristics determined by the leaf valve 8.

This also applies when the piston moves in the opposite direction.

The purpose of the present invention is to completely prevent hydraulic oil from flowing through the orifice inside the flow hole, while preventing oil from flowing in the forward direction through the flow hole. A damping valve for a hydraulic shock absorber that prevents the above-mentioned wave flow by incorporating a non-return valve that does not create resistance, and can accurately generate the damping force that was originally designed by the leaf valve. It's about providing structure.

To this end, in the present invention, each of the plurality of communication holes has a valve seat portion that faces the damping valve corresponding to the communication hole, and a valve seat portion that engages and separates from the valve seat portion based on the pressure difference between the front and rear hydraulic oil chambers. A non-return valve equipped with a valve body was installed.

The present invention will be explained below with reference to embodiments shown in FIGS. 2 and 3.

Figure 2 shows an example in which the present invention is applied to a double-acting hydraulic shock absorber.
is a piston fixed to a piston rod 3 that reciprocates within the cylinder 1, and defines the inside of the cylinder into hydraulic chambers 4 and 5.

6 and 7 are communication holes opened in this piston 2, and 8,
Reference numeral 9 designates leaf valves serving as damping valves provided at the downstream ends of these communication holes 6 and 7, respectively.

Non-return valve bodies 14 and 15 made of, for example, a thin steel plate are installed inside the enlarged diameter portions 12 and 13 as valve seats formed at the downstream ends of the communication holes 6 and 7. Valves 14, 15 make it possible to prevent backflow in the flow holes 6.7.

That is, the non-return valves 14 and 15 are moved from side to side by the differential pressure on both sides of the valve.
13, and when the hydraulic oil flows forward through the flow holes 6 and 7, the flow holes 6 and 7 are opened, and when the hydraulic fluid is to flow backward, it is pressed against the opening edges of the flow holes 6 and 7 to close the flow. Can be occluded.

16°18 is a stopper.

Therefore, according to the configuration, when the hydraulic oil flows in the forward direction through the communication holes 6 and 7, the non-return valves 14 and 15 move toward the leaf valves 8 and 9 and open the communication holes 6 and 7. Therefore, the non-return valves 14 and 15 do not provide any resistance to the flow of hydraulic oil.

Thereby, the leaf valve exhibits a predetermined throttling effect.

On the other hand, when the oil is about to flow backwards, the non-return valves 14 and 15 are moved to the low pressure side due to the pressure difference between the hydraulic chambers 4 and 5, thereby closing the inlets of the flow holes 6 and 7.

This completely prevents backflow through the flow holes 6 and 7, and does not affect the throttling action in the other valve.

FIG. 3 shows another embodiment, in which a non-return valve is attached to a valve designed to simplify processing by opening a communication hole parallel to the cylinder axis.

That is, communication holes 6', 7' communicating between the hydraulic chambers 4 and 5 are formed at the outer and inner positions of the piston 2, while leaf valves 8', 9' having different diameters are provided respectively. The large-diameter leaf valve 8' and the middle band of the stopper 16 have an opening 1 for communicating the flow hole 7' with the hydraulic chamber 4.
7 is formed.

Then, as in the previous example, there is a communication hole 6'. Expanded-diameter portions 12' and 13' are formed downstream of 7', and non-return valves 14 and 15 are installed inside the expanded diameter portions 12' and 13', respectively.

10 and 11 are orifices.

In this embodiment as well, the effect similar to that of the previous example can be achieved by the action of the non-return valves 14 and 15.

As is clear from the above explanation, the present invention has a non-return valve installed in the flow hole to prevent oil flow in the opposite direction.
On the one hand, the leaf valve at the corresponding passage hole accurately generates the specified damping force without creating any resistance to the oil flow in the forward direction, and on the other hand, by reliably blocking the oil flow in the opposite direction. It does not affect the damping force in the leaf valve of the leaf valve, and furthermore, the opening area of each orifice for the expansion side and the compression side is set for slow operation in each direction of expansion and contraction. This produces the effect that the damping forces in the directions can be set to different values.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a conventional damping valve structure, FIG. 2 is a sectional view of the damping valve structure of the present invention, and FIG. 3 is a sectional view of another embodiment. 1...Cylinder, 2...Piston, 4
, 5... Hydraulic chamber, 6, 6', 7, 7'...
...Flow hole, 8°8', 9,9' ...Leaf valve, 10, 11...Orifice, 12
, 12', 13, 13'... Expanded diameter part, 1
4,15...Non-return valve.

Claims (1)

[Scope of utility model registration request] A plurality of communication holes are provided in the piston that reciprocates within the cylinder to communicate two oil chambers defined by the piston, and an orifice is left on the downstream side of the communication hole. In a double-acting shock absorber provided with a damping valve that closes, each of the plurality of communication holes has a valve seat facing the damping valve corresponding to the communication hole, and a pressure difference between the front and rear hydraulic oil chambers. 1. A damping valve for a shock absorber, characterized in that a non-return valve is interposed, the valve body having a valve body moving into and away from the valve seat portion.