JPH0329606B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a vehicle height adjustment device used for vehicles such as automobiles. An object of the present invention is to provide a vehicle height adjustment device that can compensate for changes in vehicle posture due to changes in the vehicle's live load, and can maintain the vehicle attitude almost horizontally regardless of changes in the live load. It is something to do. The invention will now be described in detail by way of example embodiments with reference to the accompanying drawings. FIG. 1 is a schematic configuration diagram showing one embodiment of a vehicle height adjustment device according to the present invention. In the figure,
1 indicates the left and right front wheels, and 2 indicates the left and right rear wheels, respectively. The front wheel 1 is connected to the vehicle body by a suspension system including a strut device 3, a coil spring 4, and the like. The rear wheel 2 is supported by an axle housing 5, and the axle housing is connected to the vehicle body by a suspension system including a vehicle height adjustable shock absorber 6 and the like. The vehicle height adjustable shock absorber is a well-known shock absorber equipped with a pneumatic vehicle height adjustment means, and changes its effective length by supplying air pressure to an air chamber to adjust the rear wheel 2.
The height of the vehicle is now adjustable. 7 indicates an air compressor that generates air pressure for adjusting the vehicle height. The air compressor 7 is selectively driven by an electric motor 8. Air compressor 7 has conduit 9 and joint 1
0, a conduit 11, a joint 12, and conduits 13, 14 to the air chambers of the left and right shock absorbers 6, respectively, so as to supply air pressure to the air chambers. One end of a conduit 15 is connected to the joint 10, and an exhaust valve 16 is connected to the other end of the conduit. This exhaust valve 16 is constituted by a normally closed solenoid valve, and only when the solenoid 17 is energized, the conduit 1
5 to the atmosphere. Electric current is supplied to the electric motor 8 and the solenoid 17 from a battery power source 18, and the energization control is performed by a control device 19. The control device 19 controls the energization of the electric motor 8 and the solenoid 17 according to the vehicle height of the front wheels detected by the front wheel vehicle height sensor 20 and the vehicle height of the rear wheels detected by the rear wheel vehicle height sensor 21. I'm starting to do that. The energization of the motor 8 is controlled by the control device 19 controlling the opening and closing of a relay switch 22 provided in its power supply circuit. The front wheel height sensor 20 is configured as a rotary sensor, and its detection lever 24 is connected to the stabilizer bar 23 of the front wheel suspension system via link elements 25a and 25b, and senses the amount of vertical displacement of the vehicle body as the amount of rotational displacement of the stabilizer bar. It is designed to detect the vehicle height at the front wheels. An example of this front wheel height sensor 20 is shown in FIG. The front wheel height sensor 20 includes a fixed case 28 to which a photo coupler 27 is fixed, and a shaft 29 of a detection lever 24.
The rotation member 30 is connected to the rotation member 30 and rotates as the detection lever 24 rotates. A blind member 31 is attached to the rotating member 30, and the blind member 31 rotates together with the rotating member 30 to a position that crosses the optical path of the photo coupler 27 when the vehicle height of the front wheels is lower than a predetermined value. On the other hand, when the vehicle height is higher than the predetermined value, the photocoupler 27 rotates together with the rotation member 30 to a position that does not cross the optical path of the photocoupler 27. As a result, the photocoupler 27 of the front wheel height sensor 20 outputs a "0" signal when the vehicle height of the front wheels is lower than a predetermined value (low range), and outputs a "0" signal when the vehicle height is higher than the predetermined value (high range). ) outputs a “1” signal. The rear wheel height sensor 21 is configured as a rotary sensor, and its detection lever 39 is connected to the axle housing 5 via the link element 26, and detects the amount of vertical displacement of the axle housing with respect to the vehicle body, and detects the height of the vehicle at the rear wheel. It is designed to detect high temperatures.
One embodiment of the rear wheel height sensor 21 is shown in FIG. The rear wheel height sensor 21 includes a fixed case 38 to which three photo couplers 32, 33, and 34 are fixed, and a rotating member 36 that is connected to a shaft 35 of a detection lever 39 and rotates therewith. The rotating member 36 is provided with two blind members 37a and 3 that selectively block the optical paths of the photo couplers 32 to 34 according to the rotating angle of the detection lever 39.
7b is provided. three photo couplers 3
2 to 34 generate "1" or "0" signals in combinations as shown in Table 1 depending on the vehicle height at the rear wheel 2.

[Table] As can be seen from Table 1, this rear wheel height sensor 21
In this case, the vehicle height can be detected in five stages. In Table 1, the first height region is the region where the vehicle height is higher than the middle region, the second height region is the region where the vehicle height is higher than the first height region, and the first low region is the middle region. A low region where the vehicle height is lower is shown, and a second low region is a region where the vehicle height is lower than the first low region. FIG. 4 shows one embodiment of the sequence control logic circuit of the control device 19. This logic circuit has four input terminals 41 to 43, two NOR gates 44 and 45, six NAND gates 46 to 51, and four NOT gates 52 to 56.
, two AND gates 57 and 58, and two output terminals 59 and 60, the input terminal 40 is connected to the photo coupler 27 of the front wheel height sensor 20, and the input terminal 41 is connected to the photo coupler 27 of the rear wheel height sensor 21. coupler 3
2, the input terminal 42 is connected to the photocoupler 33, the input terminal 43 is connected to the photocoupler 34, the output terminal 59 is connected to the relay switch 22, and the output terminal 60 is connected to the solenoid 17. This logic circuit has four input terminals 4
Based on the signals given to 0 to 43, that is, according to the vehicle height of the front wheels and the vehicle height of the rear wheels, "1" signals are sent to the output terminals 59 and 60 in the combinations shown in Table 2. Or generates a “0” signal.

[Table] Note that when the signal at the output terminal 56 is a "1" signal, the relay switch 22 is closed and the motor 8 is energized, and when the signal at the output terminal 59 is a "0" signal, the relay switch 22 is opened. When the signal at the output terminal 60 is a "1" signal, the solenoid 17 is energized, and when the signal at the output terminal 60 is a "0" signal, the solenoid 17 is de-energized. Next, the operation of the vehicle height adjusting device having the above-described structure will be explained. First, a case will be described in which the vehicle height of the front wheels 1 is in a high range, that is, when the output signal of the photocoupler 27 of the front wheel vehicle height sensor 21 is a "1" signal. At this time, the rear wheel 2 detected by the rear wheel height sensor 21
When the vehicle height is in the intermediate range, the first low range, or the second low range, a "1" signal appears at the output terminal 59 and a "0" signal appears at the output terminal 60. Therefore, at this time, the electric motor 8 is operated with the exhaust valve 16 closed, and the air compressor 7 is driven. As a result, the air compressor 7 generates high pressure air, which is supplied to the air chambers of the left and right shock absorbers 6, respectively. This increases the effective length of the shock absorber 6 and increases the vehicle height at the rear wheel 2. When the vehicle height at the rear wheels 2 reaches the first height range due to this increase in vehicle height, "0" signals appear at the output terminals 59 and 60, and the operation of the electric motor 8 is stopped while the exhaust valve 16 remains closed. Then, the drive of the air compressor 7 is stopped, the air compressor 7 no longer generates high pressure air, and the effective length of the left and right shock absorbers 6 stops increasing. As a result, the vehicle height at the rear wheels 2 is maintained in the first height range. At that time, the vehicle's attitude will be almost horizontal. Further, when the vehicle height of the front wheels 1 is in the high range and the vehicle height of the rear wheels 2 is in the second high range, a "0" signal appears at the output terminal 59, and a "0" signal appears at the output terminal 60. 1” signal appears. At this time, the exhaust valve 16 is opened with the operation of the electric motor 8 stopped, and the air pressure supplied to the air chambers of the left and right shock absorbers 6 is exhausted, and the effective length of the shock absorbers 6 is reduced. As a result, the vehicle height at the rear wheels 2 decreases, and when the vehicle height reaches the first height region, the output terminals 59 and 6
A "0" signal appears at each of the zeros, and the exhaust valve 16 is closed while the operation of the electric motor 8 is stopped. As a result, the vehicle height at the rear wheels 2 is maintained in the first height region, and the vehicle height attitude is maintained substantially horizontal. Next, a case will be described when the vehicle height of the front wheel 1 is in a low range, that is, when the output signal of the photocoupler 27 of the front wheel vehicle height sensor 20 is a "0" signal.
At this time, when the vehicle height of the rear wheels 2 detected by the rear wheel height sensor 21 is in the intermediate range, the first height range, or the second height range, a "0" signal appears at the output terminal 59. , a “1” signal appears at the output terminal 60. Therefore, at these times, the exhaust valve 16 is opened with the electric motor 8 stopped, and the air pressure supplied to the air chambers of the left and right shock absorbers 6 is exhausted. As a result, the effective length of the left and right shock absorbers 6 is reduced, and the vehicle height at the rear wheels 2 is reduced. As a result, when the vehicle height at the rear wheel 2 reaches the first low range, the output terminals 59 and 6
All 0 signals become “0” signals, and exhaust valve 1
6 closes. As a result, the vehicle height at the rear wheels 2 is maintained in the first low range, and the attitude of the vehicle is maintained substantially horizontal. Further, when the vehicle height of the front wheels 1 is in the low range and the vehicle height of the rear wheels 2 is in the second low range, a "1" signal appears at the output terminal 59, and a "0" signal appears at the output terminal 60. appears. At this time, the electric motor 8 is operated with the exhaust valve 16 closed, and the air compressor 7 is driven. The high-pressure air generated by driving the air compressor 7 is supplied to the air chambers of the left and right shock absorbers 6, increasing the effective length of these shock absorbers and increasing the vehicle height at the rear wheels 2 accordingly.
When the vehicle height of the rear wheel 2 increases and reaches the first low range, the signals at the output terminals 59 and 60 both become "0" signals, and the electric motor 8 is activated with the exhaust valve 16 closed. Driving is stopped and the vehicle height at the rear wheels 2 is maintained in the first low range. As a result, the attitude of the vehicle is kept almost horizontal. In the above-described embodiment, the vehicle height is detected in stages by the front wheel height sensor and the rear wheel height sensor, but the vehicle height is adjusted to a higher level in order to keep the vehicle in a horizontal position. If precise control is required, a front wheel height sensor and a rear wheel height sensor that can detect the vehicle height in more stages may be used, and the vehicle posture must be controlled more strictly. In this case, a front wheel height sensor and a rear wheel height sensor configured to continuously detect the vehicle height may be used. Further, in the above-mentioned embodiment, the vehicle height adjustment means was provided on the rear wheel side, and the vehicle height of the rear wheels was adjusted according to the vehicle height of the front wheels. However, the vehicle height adjustment means may be provided on the front wheel side, and the vehicle height of the front wheels may be adjusted in accordance with the vehicle height of the rear wheels. Although the present invention has been described in detail with respect to specific embodiments above, it will be understood by those skilled in the art that the present invention is not limited thereto and that various embodiments are possible within the scope of the present invention. It would be obvious to

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing one embodiment of a vehicle height adjustment device according to the present invention, and FIG. 2 is a schematic diagram showing an embodiment of a front wheel height sensor used in the vehicle height adjustment device according to the present invention. FIG. 3 is a plan view showing one embodiment of the rear wheel height sensor used in the vehicle height adjustment device according to the present invention, and FIG. 4 is a plan view showing one embodiment of the rear wheel height sensor used in the vehicle height adjustment device according to the present invention. FIG. 2 is a diagram illustrating one embodiment of a sequence control logic circuit of a control device according to the present invention. DESCRIPTION OF SYMBOLS 1... Front wheel, 2... Rear wheel, 3... Strut device, 4... Coil spring, 5... Axle housing, 6... Shock absorber, 7...
Air compressor, 8... electric motor, 9... conduit,
10...Joint, 11...Conduit, 12...Joint, 1
3 to 15...Conduit, 16...Exhaust valve, 17...Solenoid, 18...Battery power supply, 19...Control device, 20...Body wheel height sensor, 21...Rear wheel height sensor, 22... ...Relay switch, 23...Stabilizer bar, 24...Detection lever, 25a,
25b, 26... Link element, 27... Photo coupler, 28... Fixed case, 29... Shaft, 30
...Rotating member, 31...Blind member, 32~
34...Photocoupler, 35...Shaft, 36...
Rotating member, 37a, 37a...blind member,
38...Fixed case, 39...Detection lever, 40
~43...Input terminal, 44,45...NOR gate, 46-51...NAND gate, 52-56
...NOT gate, 57,58...AND gate,
59, 60... Output terminals.

Claims (1)

[Claims] 1. A vehicle height sensor that detects the vehicle height of each of the front wheels and rear wheels, a vehicle height adjustment means that adjusts the vehicle height of either the front wheel or the rear wheel, and a vehicle detected by the vehicle height sensor. The vehicle height is adjusted so that the vehicle height of the wheel on the side where the vehicle height adjustment device is provided follows the change in vehicle height of the wheel on the side where the vehicle height adjustment device is not provided. A vehicle height adjustment device comprising a control device for controlling the operation of an adjustment means.