JPH0343843Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vehicle height adjustment device, and more particularly to a vehicle height adjustment device that exhibits an anti-roll function as well as a damping function as a shock absorber.

2. Description of the Related Art It is well known that a vehicle is equipped with a vehicle height adjustment device in order to improve the running stability of the vehicle, and various vehicle height adjustment devices have been proposed in the past. These conventional vehicle height adjustment devices are
In order to prevent the roll phenomenon where the outside of the vehicle sinks significantly when the vehicle makes a sharp turn, it has been proposed to exert an anti-roll function by generating a large reaction force on the vehicle height adjuster that is subject to the sinking effect. ing.

For example, a vehicle height adjustment device as shown in FIG. 1 has been proposed. The vehicle height adjustment device according to this proposal includes a pair of left and right vehicle height adjusters 1, 1.
In addition, each cylinder 1a constituting the vehicle height adjuster 1 has an upper chamber A and a lower chamber B defined by a piston portion 1b, and one upper chamber A is separated from the other lower chamber. The chamber B and one lower chamber B communicate with the other upper chamber A in a so-called sash-like manner. Each cylinder 1a has a gas chamber G at its upper end, and each vehicle height adjuster 1 has its upper end connected to the vehicle body side and its lower end connected to the axle side.

With this, for example, the left and right vehicle height adjusters 1,
1 contract in the same phase, each upper chamber A compresses the gas chamber G by the volume of entry of the piston rod 1c. At this time, the gas chamber G is compressed by the amount of the intrusion volume of the piston rod 1c, so the reaction force generated in each piston rod 1c is small and deteriorates the ride comfort during normal driving of the vehicle. Never. When the left and right vehicle height adjusters 1, 1 expand and contract in opposite phases, that is, when the vehicle makes a sharp turn, for example, the right vehicle height adjuster 1 in the figure contracts and the left vehicle height adjuster 1 contracts. When the vehicle height adjuster extends, the right upper chamber A is not only compressed by itself, but also receives compression from the left lower chamber B, and at this time the right gas chamber G is extremely large. undergo compression. In other words, an extremely large reaction force can be generated, an anti-roll function can be achieved, and the stability of the vehicle can be achieved.

However, when using the above conventional example, the passage must be formed in the shape of a so-called sash, so there is a drawback that installation space is easily restricted when installing it on a vehicle, and the vehicle height of this conventional example is The adjustment device is originally installed on the vehicle only to perform the anti-roll function, so a shock absorber to improve the ride comfort of the vehicle must be separately installed on the vehicle. cause And each vehicle height adjuster 1
Since the upper chamber A and the lower chamber B are formed independently from each other, if there is oil leakage from the piston part 1b or oil leakage to the outside of the cylinder 1a, the oil in the upper chamber A and the lower chamber B will be damaged. This will lead to a change in the amount or a change in the volume in the gas chamber G, and as a result, there is a fear that the characteristics of the repulsive force will change. Furthermore, in order to generate a large reaction force when even a slight roll phenomenon occurs, that is, reverse phase, the gas chamber G
are formed to be small, and therefore a large reaction force is likely to occur even when the phases are the same, resulting in disadvantages such as deterioration of the ride comfort of the vehicle and deterioration of the durability of the gas chamber G and the like.

Therefore, the purpose of this invention is to
It is convenient and economical to equip vehicles,
Furthermore, it is an object of the present invention to provide a new vehicle height adjustment device that can exhibit an anti-roll function and a damping function as a shock absorber without causing a change in repulsive force characteristics, and can improve the ride comfort and handling stability of a vehicle. It is.

In order to achieve this purpose, the structure of the present invention is
In a vehicle height adjustment device, the vehicle height adjuster has a lower end connected to the axle side and an upper end connected to the vehicle body side so that the vehicle height adjuster expands and contracts. The cylinder has an upper chamber and a lower chamber formed by dividing the inside of the cylinder, and the piston part has a damping valve that generates a damping force on the rebound side and a check valve that allows flow from the upper chamber to the lower chamber. , outside the cylinder there is a reservoir chamber separated from the upper chamber and the lower chamber, the lower chamber communicates with the reservoir chamber through a passage, and the passage is connected to a pressure side damping valve and a connection from the reservoir chamber to the lower chamber. A passageway in which a check valve that allows flow is provided in series, a passageway which is provided in parallel with the check valve and has a switching valve, and a passageway which is also provided in parallel with the check valve and in which the switching valve and the relief valve are arranged in series. The reservoir chamber and the upper chamber are connected by a passage provided with a check valve that allows flow from the reservoir chamber to the upper chamber, thereby functioning as a shock absorber. be.

Hereinafter, the present invention will be explained based on the illustrated embodiments.

As shown in FIG. 2, the vehicle height adjusting device according to the present invention includes a vehicle height adjuster 10. As shown in FIG.

The vehicle height adjuster 10 has brackets at its upper and lower ends so that its lower end is connected to an axle (not shown) and its upper end is connected to a vehicle body (not shown). . The vehicle height adjuster 10 has a piston part 15 disposed at the tip of a piston rod 14 inserted into the cylinder 13, and an upper chamber in the cylinder 13 defined by the piston part 15. A and a lower chamber B. The vehicle height adjuster 10 also includes an extension valve 16 as a damping valve in the piston portion 15.
The cylinder 13 has a check valve that allows flow from the upper chamber to the lower chamber, and a base valve part 17 at the bottom of the cylinder 13. The base valve portion 17 has a pressure side valve 18 which is a pressure side damping valve and a check valve 19. Furthermore, this vehicle height adjuster 10 has a reservoir chamber C formed outside the cylinder 13 so as to surround the cylinder 13 by an outer tube 20. Note that the inside of the upper end of this reservoir chamber C is a gas chamber G.

A passage 21 is connected to the vehicle height adjuster 10. That is, oil in the lower chamber B flows into the reservoir chamber C via the base valve section 17. And this passage 2
1 includes relief valves 22a with different set pressures,
22b, and a plurality of switching valves 28a, 28b, 2
8c.

That is, the parallel passage 2 branched from the passage 21
A switching valve 28a and a relief valve 22a are arranged in the passage 1a, and a switching valve 28b and a relief valve 22b are arranged in the other branched passage 21a. A switching valve 28c is disposed in the passage 21c. Then, each of the switching valves 28
a, 28b, 28c are signal input terminals 2, respectively.
3a, 23b, 23c, and
A signal is inputted to each signal input terminal as information about the state of the vehicle, that is, the steering wheel angle, vehicle speed, sprung mass acceleration, vehicle speed, etc., and each switching valve 28a, 28b, 28c is thereby activated. ing.

Note that a pipe line 24 is formed in parallel in the passage 21, and a check valve 25 is provided in the pipe line 24.
is arranged to allow oil to flow from the reservoir chamber C into the lower chamber B. Further, a return passage 26 communicating with the upper chamber A is connected to the passage 21, and a check valve 27 is disposed in the return passage 26.

The operation of the vehicle height adjusting device according to the embodiment shown in FIG. 2 will be explained.

First, when the vehicle height adjuster 10 is to contract, oil in the lower chamber B passes through the base valve part 17 and flows into the passage 21 due to the lowering of the piston part 15. When oil passes through this base valve portion 17, a desired compression side damping force is generated.

When the communication state of the passage 21 is as shown in the figure, that is, when only the switching valve 28a is in the communication position, the oil flowing into the passage 21 flows into one passage 21a, and the oil flows into the adjacent passage 21a. When the set pressure of the relief valve 22a is exceeded, the inside of the passage 21 is inserted toward the reservoir chamber C and the upper chamber A.
In addition, in this example, the relief valve 2
The set pressure of the relief valve 2a is lower than the set pressure of the other relief valves 22b.

Further, when the switching valve 28a is set to the cutoff position by the input, the other switching valves 28a
When b is input and the communication position is reached, passage 2
The oil in 1 will flow into another branched passage 21a. When the pressure of the inflowing oil exceeds the set pressure of the relief valve 22b, it will flow into the reservoir chamber C and the upper chamber A through the passage 21. The set pressure in the relief valve 22b is set high, and as a result, it is possible to generate a large reaction force on the piston rod 14, and it is possible to prevent a large contraction of the vehicle height adjuster 10 due to the so-called vehicle roll phenomenon. It becomes possible.

As mentioned above, the set pressure of the relief valve 22a is lower than that of the other relief valves 22b, but the set pressure is used to adjust the vehicle height when the vehicle is running at high speed or on rough roads. This causes the piston rod 14 to generate a reaction force necessary to prevent the contraction of the piston rod 10 to the extent that it occurs.

Further, if the switching valve 28a is in the cutoff position, the other switching valve 28b is also in the blocking position, and only the other switching valve 28c is switched to the communication position, the oil in the passage 21 will remain as it is. Reservoir chamber C
and flows into the upper chamber A. At this time, the damping force on the compression side is the damping force in the base valve section 17, and the damping force on the piston rod 14
In this case, the reaction force is small enough to cause the vehicle height adjuster 10 to contract, which is necessary when emphasis is placed on ride comfort when the vehicle runs on a good road.

Next, when the vehicle height adjuster 10 extends, the piston part 15 moves up inside the cylinder 13, and the oil in the upper chamber A passes through the damping valve of the piston part 15 and flows into the lower chamber B.
flow inside. At this time, a desired extension-side damping force is generated in the piston portion 15. As the piston portion 15 rises, oil corresponding to the rise of the piston rod 14 is removed from the reservoir chamber C by the check valve 25.
It flows into the lower chamber B via the pipe line 24 and the base valve section 17.

Since the vehicle height adjuster according to the present invention is configured as described above, it is no longer necessary to form a so-called swivel-like passage between the pair of left and right vehicle height adjusters as in the past, and it is easy to install the vehicle height adjuster. There is no restriction on installation space, and there is no inconvenience such as having to separately equip the vehicle with a device that functions as a shock absorber. In addition, since the upper and lower chambers defined within the vehicle height adjuster are communicated with each other via a passage, oil volume changes in each chamber due to oil leakage at the piston, etc., and the resulting repulsion force characteristics. There is also the advantage that there is no need to worry about changes in Furthermore, since the use of the gas chamber does not generate a large repulsive force, there is an advantage that even if the gas chamber itself is formed small, the riding comfort of the vehicle will not be deteriorated.

When oil flows through a passage provided with a switching valve and a relief valve, a reaction force is generated on the piston rod by the set pressure of the relief valve, thereby preventing large contraction of the vehicle height adjuster. On the other hand, when this passage is blocked and a passage having a switching valve provided in parallel with the check valve is in communication, the compression side damping valve generates a damping force to improve riding comfort when driving on a smooth road.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a conventional vehicle height adjustment device, and FIG. 2 is a circuit diagram showing a vehicle height adjustment device according to an embodiment of the present invention. 10...Vehicle height adjuster, 13...Cylinder, 14
... Piston rod, 15 ... Piston part, 16
... Extension side valve, 17 ... Base valve part, 18
...Compression side damping valve, 21...Passage, 22a, 22b
... Relief valve, 24 ... Pipe line, 25 ... Check valve, 26 ... Return passage, 27 ... Check valve, 28
a, 28b, 28c... switching valve, A... upper chamber, B... lower chamber, C... reservoir chamber, G... gas chamber.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) In a vehicle height adjustment device comprising an extendable vehicle height adjuster whose lower end is connected to the axle side and whose upper end is connected to the vehicle body side, the vehicle height adjuster The cylinder has an upper chamber and a lower chamber formed by partitioning the inside of the cylinder by a piston section disposed inside the cylinder, and the piston section has a damping valve that generates a damping force on the rebound side and a damping valve that generates a damping force on the rebound side and a damping valve that extends downward from the upper chamber. It has a check valve that allows flow, and has a reservoir chamber outside the cylinder that is separated from the upper chamber and the lower chamber, the lower chamber communicates with the reservoir chamber through a passage, and the passage is on the pressure side. A passage provided in series with a damping valve and a check valve that allows flow from the reservoir chamber to the lower chamber; a passage provided in parallel with the check valve and having a switching valve; The shock absorber is composed of a passage in which a switching valve and a relief valve are arranged in series, and the reservoir chamber and the upper chamber are further connected by a passage in which a check valve is arranged to allow flow from the reservoir chamber to the upper chamber. A vehicle height adjustment device that also functions. (2) The vehicle height adjustment device according to claim 1, wherein a plurality of passages in which switching valves and relief valves are provided in series are provided in parallel.