JPS644571Y2 - - 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 allows the spring constant of a suspension to be changed in multiple stages.

2. Description of the Related Art It is preferable for a suspension as a suspension system of a vehicle to have a variable spring constant in terms of vehicle riding comfort or vehicle handling stability. In suspensions with air springs such as hydroneumatic suspensions, the spring constant can be easily changed by making the air capacity of the air spring variable. It is possible to propose such a vehicle height adjustment device. According to this proposal,
Air capacity Vs of air spring 11 of suspension 1
changes by △Vs depending on the damper stroke.
When the communication with the air source P is cut off by the main valve 2 and the sub-valve 3 is in communication, the air capacity of the air spring 11 is reduced to the air capacity of the air tank 4.
and the air capacity Vt, that is, Vs+Vt, the volume change ΔVs in the air spring 11 becomes a small ratio, and the spring constant is changed to a so-called soft change. On the other hand, when sub-valve 3 is shut off, air spring 1
The air capacity of 1 is only Vs, and the volume change △
Vs becomes a large ratio, and the spring constant is changed to what is called a hard change. In other words, if the damper stroke is set on the X-axis and the air spring force is set on the Y-axis as shown in Figure 2, the curve will be gentle when the spring constant is soft, and the curve will be gentle when the spring constant is hard, as shown by the solid line in the figure. can be freely changed so that it becomes a steep curve.

However, air spring 1 of suspension 1
1 from an external air source P to adjust the vehicle height, which has become lower due to loading, to a desired height, or to a higher vehicle height than normal, the initial air spring 11 etc. As a result, the air spring force, that is, the spring characteristics, change as shown by the broken line (when loaded) and the dashed-dotted line (increased vehicle height) in Figure 2, which improves the ride comfort and steering stability of the vehicle. There is a risk that you will not be able to have sex.

Therefore, the present invention supplies a desired amount of air from an external air source to the air spring of the suspension to adjust the vehicle height when the vehicle is loaded or to a higher vehicle height than normal. It is an object of the present invention to provide a vehicle height adjusting device which can change a spring constant to a preferable one and does not involve a change in vehicle height when changing the spring constant.

In order to achieve this purpose, the structure of the present invention is
A suspension formed to have an air spring to enable vehicle height adjustment; and communication between the air spring of the suspension and an external air source;
A main valve that can be shut off, a plurality of air tanks each having a switching valve disposed between the suspension and the main valve, and an air spring for each air tank and suspension disposed between the air tank and the suspension. It consists of a sub-valve that allows communication and isolation between the main valve and the main valve, and the vehicle height can be adjusted by allowing the suspension to expand and contract by opening and closing the main valve. The spring constant of the suspension can be changed in multiple stages without changing the vehicle height.

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

As shown in FIG. 3, the vehicle height adjustment device according to the present invention includes a suspension 1, a main valve 2,
It has a sub-valve 3 and air tanks 4, 4',
A switching valve 5, 5' is connected to each air tank 4, 4'.

The suspension 1 has an air spring 11, the upper end of which is connected to the vehicle body side, and the lower end connected to the wheel side. Although only one suspension 1 is shown in the drawing, it goes without saying that there are four suspensions for independently suspending each wheel of a four-wheeled vehicle. In addition, in this embodiment, the suspension 1 is made up of a hydroneumatic suspension that also includes a coil spring, but instead of this, it is possible to use a suspension that simply uses an air spring 11 as the main suspension spring. Of course, it is a good thing. In that case, it is sufficient that the suspension 1 is formed so that the desired vehicle height can be adjusted by making the air capacity Vs in the rubber bellows constituting the air spring 11 variable, for example. Furthermore, in the case of a hydroneumatic suspension as in this embodiment, it is possible to adjust the vehicle height as desired by expanding and contracting the attached coil spring, for example. good.

The main valve 2 enables communication or isolation between the air source P disposed outside and the air spring 11 of the suspension 1.
2, a shutoff valve 21, and a switching mechanism 23 consisting of a solenoid that switches each valve to either one. Therefore, by opening and closing the main valve 2, a desired amount of air can be supplied or discharged or shut off as desired. Note that the solenoid in the switching mechanism 23 may be operated manually, or may be automatically operated based on sensor detection. Furthermore, it is of course possible to eliminate the solenoid equipment and simply switch to each valve manually.

The sub-valve 3 is disposed between the air spring 11 of the suspension 1 and each air tank 4, 4' described later, and communicates or blocks air between the air spring 11 of the suspension and each air tank 4, 4'. The aim is to The sub-valve 3 includes a communication valve 31, a cutoff valve 32, and a switching mechanism 33 that selectively switches each valve to either one. Therefore, by operating the switching mechanism 33 to switch to either valve, the air capacity Vs of the air spring 11 of the suspension 1 can be made variable as desired.

The air tanks 4 and 4' contain air of fixed capacities Vt and Vt', and in this embodiment,
Although it is assumed that two of the same capacity are installed, it is of course possible to use three or more of the same capacity or two or three or more of different capacities instead. . Further, each air tank 4, 4' has a switching valve 5,
5' are connected in series. Each of the switching valves 5, 5' includes a communication valve 51, 51' that allows air to communicate between each air tank 4, 4' and the main valve 2 and sub-valve 3, and a cutoff valve that blocks the communication. 52, 52' and switching mechanisms 53, 53' that enable switching to each valve are formed. Therefore, it is possible to operate the switching mechanisms 53, 53' to establish or cut off air communication between the inside of the air tank and the main valve 2 and the sub-valve 3 as desired.

Note that the switching mechanism 33 in the sub-valve 3 and the switching mechanisms 53, 53' in the switching valves 5, 5'
There is no difference in the structure and operation from the switching mechanism 23 of the main valve 2 described above, and the same can be said of the modified examples.

The operation of the vehicle height adjusting device according to the present invention configured as above will be explained next.

First, when only the spring constant of the suspension 1 is to be made variable while maintaining the preset normal vehicle height, the following procedure is performed.

That is, the main valve 2
side, and cut off the air supply from the external air source P. When a so-called hard spring constant is used, the sub-valve 3 is placed on the shut-off valve 32 side. As a result, the air capacity Vs of the air spring 11 of the suspension 1 remains at a small rate of change of capacity ΔVs only within the bellows, and a desired hard spring constant can be obtained.

In addition, when setting the desired soft spring constant,
First, set the sub-valve 3 to the communication valve 31 side, and if you want the softest version, set each air tank 4,
The switching valves 5, 5' connected to the valve 4' are placed on the side of the communication valves 51, 51'. This results in
The air spring 11 of the suspension 1 and each air tank 4, 4' are communicated, and the air capacity of the air spring 11 is
Vs+Vt+Vt', exhibiting an extremely large rate of change in capacitance, making it possible to obtain the desired extremely soft spring constant.

In order to set the spring constant between the above two, only the switching valve 5 connected to one of the air tanks 4 should be set to the cutoff valve 52 side, and the switching valve 5 connected to the other air tank 4' should be set to the cutoff valve 52 side. It is sufficient to place the valve 5' on the communication valve 51 side. and,
If the air tanks 4, 4' have different air capacities, one of which has a larger air capacity than the other,
By communicating with or blocking one of the air tanks 4, 4', the spring constant can be changed to a multi-stage spring constant.

If you want to make the vehicle height higher than the normal vehicle height or if you want to adjust the vehicle height lowered due to loading, the main valve 2 is set to the communication valve 22 side and the sub valve 3 is set to the communication valve 31 side. It is sufficient to supply a desired amount of air into the air spring 11 of the suspension 1. Even if the air spring 11 has an internal pressure higher than the initial one, a desired spring constant can be selected by communicating with each air tank 4, 4' or with either one, and the spring This makes it possible to prevent the change in force from deteriorating the ride comfort of the vehicle or destabilizing the maneuverability of the vehicle. Furthermore, when changing the spring constant to a soft spring constant after adjusting the vehicle height with the air spring 11 set to a hard spring constant, the spring constant can be changed without causing a change in the vehicle height by using the sub-valve 3. I can do it. In other words, if the air spring 11 is set to a hard spring constant and the vehicle height is adjusted higher in response to a change in load capacity, etc., and then the air spring 11 is changed to a soft spring constant, the vehicle height adjustment Air spring 1 with increasing pressure
1 and the air tanks 4, 4' having a lower pressure are suddenly brought into communication, the pressure of the air spring 11 decreases and the vehicle height decreases. Therefore,
First, the sub-valve 3 is left on the shutoff valve 32 side, that is, the communication between the air spring 11, each air tank 4, 4', and the air source P is cut off, and the switching of each air tank 4, 4' is performed. Switch the valves 5, 5' to the communication valves 51, 51' side. Then, the main valve 2 is switched to the communication valve 22 side, and the air source P
After supplying air to each air tank 4, 4' from the air tank 4, 4' and increasing the pressure in each air tank 4, 4' to the same pressure as the air spring 11, the main valve 2 and, if necessary, the switching valve 5, 5' are opened. Switch one of them to a shutoff valve.
Next, the sub-valve 3 is placed on the communication valve 31 side, and both or one of the air tanks 4 and 4' are connected to the air spring 11.
communicate with. Thereby, the spring constant of the air spring 11 can be set to a soft state without lowering the vehicle height.

As described above, according to the present invention, the spring constant of the suspension can be freely changed even when the vehicle is at a normal vehicle height, so that the ride comfort and steering stability of the vehicle can be improved. Further, when the vehicle height is adjusted when the vehicle is loaded, or when the vehicle height is desired to be higher than the normal vehicle height, the desired spring constant can be selected in multiple stages. In addition, when changing the air suspension's air spring to a soft spring constant after adjusting the vehicle height with a hard spring constant, for example, by using a sub-valve, you can adjust the spring constant without changing the vehicle height. can be changed. Therefore, it is possible to maintain a favorable ride comfort or favorable handling stability of the vehicle without causing a change in vehicle height due to a change in the spring constant.

[Brief explanation of the drawing]

FIG. 1 is a diagram schematically showing a conventional vehicle height adjustment device, FIG. 2 is a diagram showing an example of change in spring characteristics, and FIG. 3 is a diagram showing a vehicle height adjustment device according to the present invention in the same way as FIG. 1. It is a diagram. 1...Suspension, 2...Main valve,
3...Sub valve, 4, 4'...Air tank, 5,
5'...Switching valve, 11...Air spring, P...
Air source.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A suspension formed to have an air spring to enable vehicle height adjustment, and communication between the air spring of the suspension and an external air source. , a main valve that can be shut off, a plurality of air tanks that are arranged between the suspension and the main valve, each having a switching valve, and a plurality of air tanks that are arranged between the air tank and the suspension, and that are arranged between the air tanks and the suspension. a sub-valve that enables communication and isolation with the spring;
By opening and closing the main valve, the suspension can be expanded and contracted to adjust the vehicle height, and by opening and closing selected sub-valves and switching valves, the vehicle height can be adjusted without changing the vehicle height. A vehicle height adjustment device characterized by being formed so that the spring constant of a suspension can be changed in multiple stages. (2) The vehicle height adjustment device according to claim 1, wherein the suspension is provided with a coil spring. (3) The vehicle height adjustment device according to claim 1, wherein each of the plurality of air tanks is formed to have the same air capacity. (4) The vehicle height adjustment device according to claim 1, wherein the plurality of air tanks are formed to have different air capacities.