JPH017607Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an actuator for a hydraulic suspension for a vehicle, and more particularly to an actuator for a hydraulic suspension for an automobile, etc., which prevents damage to a diaphragm that partitions a gas chamber as an accumulator.

As a conventional hydraulic suspension actuator incorporating this type of accumulator in the actuator, the one shown in FIG. 1 has been developed by the present applicant.

That is, a cylinder 2 is disposed concentrically with the outer shell 1, a piston rod 4 is slidably inserted into the cylinder 2 via a piston 3, and the piston 3 has piston valves 5 and 6 built therein. The piston 3 defines two oil chambers 7 and 8 within the cylinder 2, and the two oil chambers 7 and 8 communicate with each other via piston valves 5 and 6.

An accumulator is arranged outside the cylinder 2. That is, both ends of the diaphragm 9 are kept sealed, a gas chamber 10 filled with nitrogen gas etc. is defined inside the diaphragm 9, and an oil chamber 11 is defined between the diaphragm 9 and the outer shell 1. 11 communicates with the oil chamber 8 through ports 13 and 14 formed in the bottom 12. An oil hole 15 is formed in the piston 4 in the axial direction, and the oil chamber 8 is communicated with or shut off from a hydraulic power source through the oil hole 15. When the oil chamber 8 communicates with the pump, high pressure oil is guided to the piston rod 4. The piston rod 4 is compressed when the piston rod 4 is expanded and communicated with the tank. Further, a gas filling hole 16 is formed in the bottom 12, and after nitrogen gas is filled into the gas chamber 10 through the gas filling hole 16, the gas chamber 10 is sealed with a stopper.

In the diagram of outer shell 1, the left side is gas chamber 10.
The diameter of the right side is reduced through a stepped portion 17, and this reduced diameter portion 18 is press-fitted into the knuckle and connected to the axle side of the vehicle. The outer end of the piston rod 4 is connected to the vehicle body.

In the above hydraulic suspension actuator, the oil chamber 8 expands when the piston rod is extended, and the oil corresponding to the volume of the piston rod 4 that has come out of the cylinder 2 flows into the oil chamber 8 from the oil chamber 11 through the ports 13 and 14. For this reason, the gas chamber 10 by the volume of the piston rod 4 expands due to the gas pressure, and the diaphragm 9 expands, so that the outer periphery of the diaphragm 9 comes into contact with the stepped portion 17 of the outer shell 1, and as this movement is repeated, There was a risk that the contact portion of the diaphragm 9 would be damaged. Furthermore, when the diaphragm 9 comes into contact with the oil chamber 11, the oil passage in the oil chamber 11 may be restricted, impairing the flow of oil. In addition, the oil chamber 11 is damaged due to the expansion and contraction of the piston rod 4 and due to vibrations under the spring.
There was a problem in that the diaphragm 9 was damaged not only by the contact of the diaphragms but also by the flow of oil from the narrow flow path inside the stepped portion 17.

Therefore, the object of the present invention is to provide an actuator for a hydraulic suspension that does not impair the durability of the diaphragm even if the diaphragm comes into contact with the stepped portion of the outer shell or oil flows from a narrow flow path. The goal is to provide the following.

In order to achieve this objective, the present invention arranges a cylinder concentrically within an outer shell in which an inwardly facing step is formed between a large diameter part and a reduced diameter part, and The piston rod is slidably inserted through the piston, a diaphragm is interposed between the outer shell and the cylinder, an oil chamber is defined between the diaphragm and the outer shell, and a gas chamber is defined between the diaphragm and the cylinder. In the actuator for hydraulic suspension,
The present invention is characterized in that at least a portion of the diaphragm facing the stepped portion of the outer shell is formed thick.

An embodiment of the present invention will be described below with reference to FIG. 2 and subsequent figures.

The hydraulic suspension actuator according to the preferred embodiment of FIG. 2 is basically the same as the prior art shown in FIG.

That is, the outer shell 1 is composed of a reduced diameter part 18 on the right side, a large diameter part 18a on the left side, and a stepped part 17 facing inward, and a head cap 1 is provided at the end of the large diameter part 18a.
9 and bearing 20 are held through a seal,
A bottom cap 21 is held at the end of the reduced diameter portion 18 via a seal.

A cylinder 2 is disposed inside the outer shell 1 and coaxially therewith.The left end of the cylinder 2 is held by a bearing 20, and the right end is press-fitted into the bottom 12 via a seal. The end of the bottom 12 is inserted into the bottom cap 21 and held upright.

A piston rod 4 is slidably inserted into the cylinder 2 via a piston 3, and the piston rod 4 passes through a bearing 20 and a seal 22 and projects to the outside.

The piston 3 divides the cylinder 2 into two left and right oil chambers 7, 8, and the piston 3 is provided with fixed or variable piston valves 5, 6, through which two oil chambers 7, 8 are provided. Rooms 7 and 8 are connected.

A diaphragm 9 is extendably arranged on the outside of the cylinder 2, and both ends of the diaphragm 9 are hermetically held via a bearing 20 and clamping parts 23 and 24 of the bottom 12. A gas chamber 10 filled with nitrogen gas as a mulrator is partitioned.

Further, an oil chamber 11 is defined between the diaphragm 9 and the outer shell 1, and this oil chamber 11 communicates with the oil chamber 8 through a radial port 13 and an axial port 14 formed in the bottom 12.

Nitrogen gas is filled into the gas chamber 10 from the outside through a gas filling hole 16 formed in the bottom 12, and after filling, the gas filling hole 16 is sealed with a plug or the like.

An oil hole 15 is formed in the axial direction of the piston rod 4, the right side end of the oil hole 15 opens into the oil chamber 8, and the left side end communicates with a hydraulic pressure source.

That is, as shown in the circuit shown in FIG. 3, the oil hole 15 of the piston rod 4 of the hydraulic suspension actuator A is connected to the pump 29 or When the tank 30 is selectively communicated with or shut off, and pump pressure is supplied to the oil hole 15, the piston rod 4 of the suspension A expands, for example, to raise the vehicle height of the automobile, and when it communicates with the tank 30, the piston rod 4 expands. It is compressed to lower the vehicle height.

When the piston rod 4 is extended, the oil chamber 8 expands, and oil corresponding to the volume of the piston rod 4 that has come out is introduced from the oil chamber 11 through the ports 13 and 14.
When the piston rod 4 is compressed, the oil in the oil chamber 8 flows out into the oil chamber 11. Also, when the piston 3 is extended or compressed, the oil chamber 7,
8 flows out, and at this time a damping force is generated due to the flow resistance of the piston valve 5 or 6.

The reduced diameter portion 18 of the outer shell 1 is connected to the axle side of the vehicle via a nutcle, and is connected to the piston rod 4.
The outer end is connected to the vehicle body.

Therefore, the main part of the present invention is to increase the wall thickness of a part or all of the right diameter reduced part of the diaphragm 9, especially the part 9a facing the step part 17 of the outer shell 1, and The wall thickness on the left side is made smaller, thereby changing the rigidity of the diaphragm 9, improving the durability of the thicker part, and reducing the expansion of the thicker part even when gas pressure is applied. This is what I do.
For this reason, when the piston rod 4 is extended, the oil in the oil chamber 11 flows into the oil chamber 8, and even if the gas chamber 10 expands by the volume of the piston rod 4 and the diaphragm 9 expands, the thick part does not expand significantly, so the outer It does not come into contact with the stepped portion 17 of the shell 1, and even if it does come into contact, it is only slight and will not cause damage. Furthermore, even if a large contact were to occur, the wall thickness is high and the durability is high, and the rate of damage is extremely small.

Furthermore, if the expansion of the thick portion 9a is small, a sufficient oil passage between the diaphragm 9 and the outer shell 1 is secured, and almost no damage occurs due to oil flow.

4 and 5 relate to other embodiments of the present invention,
This has a plurality of ribs 9b provided on a part of the inside of the diaphragm 9, which makes a part of the diaphragm thicker, increasing its rigidity and improving its durability.

Similarly, FIG. 6 and FIG. 7 relate to an embodiment of the present invention, in which an elastic body 9c such as rubber is fixed in a rib shape or integrally formed on the outer periphery of the outer shell in the vicinity opposite to the stepped portion 17. It is something.

In this case as well, the elastic body 9c causes the diaphragm 9 to
The rigidity of some parts is greater, improving durability. Also, since a plurality of gaps 9d are formed between the elastic bodies 9, even if the diaphragm 9 comes into contact with the reduced diameter part or step part of the outer shell 1 during expansion, a sufficient oil passage will be formed by the gaps 9d. It is something that

As described above, according to the present invention, since a part of the diaphragm is made thick, this part has strong rigidity.
Even when the gas pressure in the gas chamber is applied, there is little expansion, so a sufficient oil passage is always formed, and even if it expands and comes into contact with the step part of the outer shell repeatedly, it is durable and will not be easily damaged. There is no risk of damage caused by oil flow.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional front view of a conventional actuator for hydraulic suspension, Fig. 2 is a longitudinal sectional front view of an actuator for hydraulic suspension using a diaphragm according to an embodiment of the present invention, and Fig. 3 is a longitudinal sectional front view of an actuator for hydraulic suspension. A hydraulic circuit diagram connected to an actuator, FIG. 4 is a partially vertical front view of a diaphragm according to another embodiment, FIG. 5 is a cross-sectional side view taken along line A-A in FIG. 4, and FIG. A partially longitudinal front view of such a diaphragm, FIG. 7 is taken along line B-B in FIG.
It is a line cross-sectional side view. 1...Outer shell, 2...Cylinder, 3...
... Piston, 4 ... Piston rod, 9 ... Diaphragm, 9b ... Rib, 9c ... Elastic body, 10
... Gas chamber, 11 ... Oil chamber, 17 ... Stepped section, 18
...Reduced diameter part, 18a...Large diameter part.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A cylinder is disposed concentrically within an outer shell in which an inwardly facing stepped portion is formed between a large diameter portion and a reduced diameter portion; A piston rod is slidably inserted through the piston,
In the hydraulic suspension actuator, a diaphragm is interposed between the outer shell and the cylinder, an oil chamber is defined between the diaphragm and the outer shell, and a gas chamber is defined between the diaphragm and the cylinder. An actuator for a hydraulic suspension, in which at least a portion of a diaphragm facing a stepped portion is formed thick. (2) The actuator for a hydraulic suspension according to claim 1, wherein the thick wall portion is formed of an inner circumferential rib. (3) The actuator for a hydraulic suspension according to claim 1, wherein the thick portion is formed of an elastic body such as rubber fixed to the outer periphery.