JPS59216712A - Level-control device - Google Patents

Abstract

PURPOSE:To make a spring constant in a suspension variable as well as to secure good driving comfortableness and steering stability despite being simple in structure, by installing a selector valve which interconnects or intercepts an interval between an air source and an air spring. CONSTITUTION:When a selector valve 3 is selected to the side of an interconnecting valve 31, both sides of an air spring 13 of a suepension 1 and an air tank 21 of an air source 2 are interconnected with each other whereby there comes to a large quantity in capacity. Therefore, a spring constant in the suspension 1 is changed over to soft. In contrast with this, when the selector valve 3 is selected to the side of a cutoff valve 32, interconnection between both insides of the air spring 13 of the suspension 1 and the air tank 21 of the air source 2 is cut off, and the capacity comes to small to the inside of the air spring alone so that the spring constant of the suspension 1 is changed over to hard.

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 in which the spring constant of a suspension can be made variable.

Various vehicle height adjustment devices have been proposed in the past, but these devices are equipped with a control circuit inside the suspension that performs the functions of adjusting the vehicle height and changing the spring constant.
Not only does the structure become complicated, but the number of parts also increases, and as a result, the vehicle height adjustment device itself becomes expensive. Therefore, although it is desirable to equip a vehicle with a vehicle height adjustment device that can change the spring constant of the suspension, it is only installed on so-called Jij-class vehicles, and is relatively inexpensive. So-called popular vehicles such as light vehicles were not to be equipped with this system.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a vehicle height adjustment device that can be installed even in relatively inexpensive vehicles such as light trucks, and that can make the spring constant of the suspension variable.

In order to achieve this object, the present invention has a structure including a suspension having an upper end connected to the vehicle body side, a lower end connected to the wheel side, and having an air spring, and an air source disposed outside the suspension. and a switching valve that enables communication and isolation between the air source and the air spring,
The present invention is characterized in that the spring constant of the suspension can be made variable by communicating or cutting off the air spring and the air source.

The present invention will be explained below based on the illustrated embodiments.

As shown in Figure 1, the vehicle height adjustment device according to the present invention includes a suspension (1), an air source (2), and a switching valve (3).
A hydraulic cylinder (4) is connected to the suspension (1).

The suspension (1) has an upper end connected to the vehicle body A side and a lower end connected to the wheel (not shown) side,
In this embodiment, a hydropneumatic suspension is used. The suspension is set up with four suspensions that suspend each of the vehicle's four wheels independently.

This suspension (1) has a coil spring (12) supported by a cylinder (01), and also has a coil spring (12) supported by a cylinder (01).
11) An air spring (13) is provided outside the upper end. The lower end of the coil spring (121) is supported by a spring receiver cylinder αa held by a spring receiver (12) fixed to the outer periphery of the cylinder (11). is installed.

This piston 04) is raised or lowered by operating the external hydraulic cylinder (4) to contract or expand the upper coil spring 02). Note that the upper end of the coil spring α2) is connected to the vehicle body A. Therefore, if the piston side of the spring receiving cylinder (14) is raised to shorten the coil spring (I2), the weight of the vehicle body A will not change.

When the vehicle height becomes higher, if the piston αδ is lowered, the vehicle height becomes lower and the vehicle height can be adjusted.

The air spring (13) is made of a bellows containing air or gas, and one side of the bellows is connected to the cylinder (11).
The piston rod (connected to lω and the other end of the bellows is connected to the outer periphery of the cylinder 01) which is inserted into the cylinder and projects outside. A piston (15) that moves up and down inside the cylinder (111) is attached to the piston rod (circle), and one side is opened into the air spring (13), and the other side is a through hole that opens at the upper end of the piston rod (151). (The upper end of the piston rod (151) is connected to the vehicle body A with a nut (17) via a bracket (16), a buffer material A6), etc. The external air source (2) is connected to the switching valve (3) through the through hole ab bored in the piston rod f15).
) are connected via.

In this embodiment, the air source (2) is comprised of an air tank (21) containing a fixed volume of air.

In addition, the switching valve (3) is intended to communicate or cut off air between the air source (2) and the suspension (1). It has a switching mechanism (33) consisting of a solenoid for controlling the switching valve (3).It goes without saying that this switching mechanism (33) may be configured to be operated manually. When switched to the communication valve (31) side, the inside of the air spring side of the suspension (1) and the inside of the air tank (21) of the air source (2) are communicated, and the spring constant of the Lee suspension (1) is so-called. In addition, when the switching valve (3) is switched to the shutoff valve (321 side), communication between the air spring (131) of one suspension (1) and the air tank (2I) of the air source (2) is cut off. As a result, only the air spring (13) has a small capacity, and the spring constant of the suspension (1) is changed to a so-called hard one.

The hydraulic cylinder (4) connected to the suspension (1) has a cylinder body (411) and a drive motor (42).
1 are connected in series, and the drive shaft (431) is rotated by the rotation of the drive motor (42), and the piston (44) is slid within the cylinder body (41) along with the rotation. The oil contained in the cylinder body (41) is discharged to the outside of the cylinder (4) by the forward movement of the piston (44), and the oil is discharged into the cylinder body (41) by the backward movement of the piston (44). Therefore, by rotating the drive motor (42) as desired, the spring receiving cylinder (1) of the suspension (1)
The piston (151) inside can be raised or lowered.

Figure 2 shows a vehicle height adjustment device according to another embodiment of the present invention, and this device consists of a suspension (i), an air source (2), and a switching valve (3).

The four wheels of a vehicle are suspended independently, and a suspension (1) and a switching valve (3) are installed around each wheel.

Suspension (1), in this embodiment, is an air suspension whose upper end is connected to the vehicle body A side and whose lower end is connected to the wheels (not shown). The suspension (1) includes an air spring (13) in a cover (08) attached to the upper end of the cylinder (11).
)have. This air spring (13) I consists of a bellows containing air or gas, one end of the bellows is connected to the outer periphery of the cylinder 0D, and the other end of the bellows is a piston inserted into the cylinder (■1). It is connected to the rod (15). A piston (15) that moves up and down within the cylinder (11) is disposed at the lower end of the piston rod (15). This piston rod (151 has an air spring (13
) is provided with a through hole 09 opening into the piston rod (15) and opening the other end into the upper end of the piston rod (15). An external air source (2) is connected to the upper end opening of the through hole (15) via a switching valve (3).

Also, the upper end of the piston rod is a bracket (16).
, and is connected to the vehicle body A by a nut (Iη) with a buffer material (te) interposed therebetween.

In this embodiment, the air source (2) is composed of an air cylinder, and its air capacity can be made variable by driving a drive motor (23) connected to the cylinder body (2211/C). That is, a cylinder (bellows T24 inside the cylinder) is disposed, and the bellows (
The bridge member (2■) connected to 24 is connected to the cylinder body (221
The air capacity inside the bellows can be varied by moving it forward and backward within the cylinder body (22). Therefore, when the drive motor c23 of the air source (2) is operated as desired, the piece member (c) moves within the car cylinder (22) and the bellows (c) moves.
24) can be discharged and inserted into the air spring 03) of the suspension (1). Air spring (I3
), the air spring (13) will expand by the amount supplied, but since this is restricted by the cover, the piston rod 15) will not be able to move into the cylinder (1).
It will be made to protrude from within 1. Since the lower end of the cylinder (11) is considered to be fixed and layered on the wheel side, the vehicle body A will rise by the amount of rise of the piston rod (1), that is, the vehicle height will be adjusted higher. If the bridge member (c) of the air source (2) is moved back inside the cylinder body (221) so as to discharge the air inside the air spring (131), then the piston rod (15) will be released from inside the air spring (13). The amount of air discharged will enter the cylinder 00, and the vehicle body A will be lowered, that is, the vehicle height will be adjusted lower.

The above switching valve (3) connects the air source (2) and the suspension (
1), and has a switching mechanism (33) consisting of a communication valve (31), a cutoff valve (3z), and a solenoid for switching to each valve. Of course, this switching mechanism (33) may be configured to be operated manually.

Therefore, when the total changeover valve (3) is operated to the communication valve (31) side, the inside of the air spring (13) of the suspension (1) and the inside of the bellows (24) of the air source (2) are communicated with each other, resulting in a large capacity. The spring constant of rl) is .

It is changed to so-called software. Furthermore, when the 1-.° switching valve (3) is switched to the shutoff valve bell side, the communication between the inside of the air spring r13) of the suspension fl) and the inside of the bellows (24) of the air source (2) is cut off, and the air spring ( 13) Small capacity only inside.

The spring constant of the suspension (1) is so-called hard changed.

As described above, according to the present invention, there is no need to provide a complicated control circuit inside the suspension to perform the function of adjusting the vehicle height and the function of changing the spring constant of the suspension, so the structure is simplified. The number of parts is also reduced, and as a result, an inexpensive vehicle height adjustment device can be obtained, and its versatility can be increased not only for so-called luxury cars but also for so-called mass-market cars such as light vehicles. Then, with the desired vehicle height adjusted,
Since the spring constant of the suspension can also be changed, it is possible to obtain good ride comfort and steering stability regardless of the road surface conditions.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a diagram schematically showing an embodiment of the vehicle height adjustment device according to the present invention, and Fig. 2 is a diagram showing another embodiment similarly to Fig. 1. (1)...Suspension-(2)...Air source, (
3)...Switching valve-02)...Coil spring, (13)
...Air spring, A...Car body. Representative Patent Attorney Izumi Amano Figure 2

Claims (5)

[Claims] (1) A suspension having an upper end connected to the vehicle body side and a lower end connected to the wheel side and having an air spring, an air source disposed outside the suspension, and the air source and the air spring. 1. A vehicle height adjustment device comprising: a switching valve capable of communicating and cutting off the air spring, and making it possible to vary the spring constant of the suspension by communicating and cutting off the air spring and the air source. (2) The suspension has a suspension spring and is formed to be able to adjust the vehicle height by expanding and contracting the suspension spring, and the air source is a tank with a fixed capacity. Vehicle height adjustment device. (3) The vehicle height adjusting device according to claim 1, wherein the suspension is formed to be able to adjust the vehicle height by making the air capacity of the air spring variable, and the air source is an air cylinder. . (4) The vehicle height adjustment device according to claim 1, wherein the air spring is a bellows containing air or gas. (5) The vehicle height adjusting device according to claim 2, wherein the suspension has an orifice or a valve to provide a desired damping effect when the piston slides.