JPH0741782B2 - Vehicle height control device - Google Patents

Description

The present invention relates to a vehicle height control device.

[Prior art]

Conventionally, in this type of vehicle height control device, the vehicle height control is performed while maintaining the balance of the vehicle height control speed on each wheel side of the vehicle according to the difference between the target vehicle height and the actual vehicle height. There is.

[Problems to be solved by the invention]

However, in such a configuration, even when the vehicle body leans due to rolling or the like, the leaning of the vehicle body is corrected as a result of the vehicle height control described above without directly performing the leaning control of the vehicle body. However, there is a problem that such correction takes time, and as a result, it becomes insufficient to secure the riding comfort and the maneuverability of the vehicle.

Therefore, the present invention intends to provide a vehicle height control device that positively corrects and controls the inclination itself when the vehicle body leans in order to cope with such a problem.

[Means for solving problems]

In solving such problems, the structural features of the present invention are as follows.
As illustrated in FIG. 1, in a vehicle having first, second, ..., Nth wheels, an actual vehicle near each of the first, second, ..., Nth wheels. The first, second, ...
.., 1st, 2nd, ... Generated as nth vehicle height detection signal
.., 1n, vehicle height detection means 1a, 1b, ..., 1n, a target vehicle height 2A near the first wheel, and a value of the first vehicle height detection signal, the second wheel , The difference between the target vehicle height 2B near the second vehicle height detection signal and the target vehicle height 2N near the nth wheel and the value of the nth vehicle height detection signal. 1st, 1st
2, ..., Main vehicle height difference calculating means 2 for calculating the nth main vehicle height differences 2a, 2b, ..., 2n respectively, and the first, second, ...
.. Average vehicle height determining means 3 for averaging the respective values of the n-th vehicle height detection signal to determine the average vehicle height, and the difference between the average vehicle height and the value of the first vehicle height detection signal, The difference between the average vehicle height and the value of the second vehicle height detection signal, ..., The difference between the average vehicle height and the value of the nth vehicle height detection signal, the first, second, ... Auxiliary vehicle height difference calculating means 4 for calculating the nth auxiliary vehicle height differences 4a, 4b, ..., 4n respectively, and the first, second, ..., Nth calculated main vehicle height differences 2a, 2b. , ..., 2n is the first, second, ..., The first, second required to reduce the inclination of the vehicle body in accordance with the nth calculation auxiliary vehicle height difference 4a, 4b ,. ..., nth corrected main vehicle height difference
Correction means 5 for correcting 5a, 5b, ..., 5n respectively
And the 1st, 2nd, ..., The nth corrected main vehicle height difference 5a, 5b, ...
.., 1st, 2nd, ... Adjusting the actual vehicle height in the vicinity of each of the 1st, 2nd, ...
The second, ..., Nth adjusting means 6a, 6b ,.

[Action effect]

Thus, by configuring the present invention in this way, when the vehicle body of the vehicle in the vehicle height control state tilts,
The second, ..., The n-th vehicle height detecting means 1a, 1b ,.
The first, second, ..., Nth vehicle height detection signals are generated,
The main vehicle height difference calculating means 2 uses the difference between the target vehicle height 2A and the value of the first vehicle height detection signal, the difference between the target vehicle height 2B and the value of the second vehicle height detection signal, ... The difference between the vehicle height 2N and the value of the n-th vehicle height detection signal is the first, second, ..., Nth main vehicle height difference 2a, 2b ,.
.., 2n, and the average vehicle height determining means 3 determines the average vehicle height based on the first, second, ..., Nth vehicle height detection signals.

Then, the auxiliary vehicle height difference calculating means 4 calculates the difference between the average vehicle height and the value of the first vehicle height detection signal, the average vehicle height and the second vehicle height.
The difference between the value of the vehicle height detection signal, ..., The difference between the average vehicle height and the value of the nth vehicle height detection signal is defined as the first, second, ..., Nth auxiliary vehicle height difference 4a. , 4b, ..., 4n, respectively, and the correction means 5 performs the first, second, ... Nth operation main vehicle height difference 2a, 2b, ...
., 2n is the first, second, ..., The nth calculation-assisted vehicle height difference 4a, 4b,
..., 4n depending on the 1st, 2nd, ..., nth corrected main vehicle height difference 5a, 5b, ..., 5n, respectively, and
2, ..., The n-th adjusting means 6a, 6b ..., 6n are the first, second, ...
.., at the adjustment speed according to the nth corrected main vehicle height difference
The actual vehicle height near each of the first, second, ..., Nth wheels is adjusted.

In other words, the vehicle height adjustment in the vicinity of the first wheel is performed by the first adjusting means 6a by adding the first auxiliary vehicle height difference 4a to the first main vehicle height difference 2a, and the second adjusting means 6b is used. Second
The vehicle height adjustment near the wheels is performed by adding the second auxiliary vehicle height difference 4b to the second main vehicle height difference 2b, ..., The vehicle height adjustment near the nth wheel by the nth adjusting means 6n. Is performed by adding the nth auxiliary vehicle height difference 4n to the nth main vehicle height difference 2n, so that even if the vehicle body tilts, this inclination correction control is positively and promptly performed together with the vehicle height control. As a result, the ride comfort and maneuverability of the vehicle can always be sufficiently ensured.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.
FIG. 3 and FIG. 3 are overall configuration diagrams showing an example in which the vehicle height control device according to the present invention is applied to a vehicle. The vehicle height control device is
It has a plurality of shock absorbers 10a, 10b, 10c, 10d, and each of these shock absorbers 10a, 10b, 10c, 10d,
The vehicle is located on the left and right front wheels and on the left and right rear wheels, respectively, and is interposed between the sprung member and the unsprung member of the suspension mechanism of the vehicle. Then, the shock absorbers 10a to 10d control the distance between the front sprung member and the unsprung member (that is, the vehicle height) according to the pressure oil applied to the cylinder upper chamber.

Further, the vehicle height control device has a hydraulic pump P, which is driven by a DC motor (not shown) to pump hydraulic oil from the reverser R through the oil passage 11 to the oil passage.
Discharge pressure oil into 12. The accumulator Acc receives pressure oil from the hydraulic pump P through the oil passage 12 and accumulates pressure. The flow rate control mechanisms 30a, 30b, 40a, 40b, 50a, 50b, 60a, 60b are both configured by a linear actuator and a flow rate control valve, and the flow rate control valve of the flow rate control mechanism 30a is connected to the oil passage 12. The shock absorber 10a is interposed in an oil passage 13a connected to an oil passage 14a extending from the cylinder upper chamber. Then, the flow rate control mechanism 30a is proportional to the operation amount of the linear actuator, which is proportional to the exciting current to the linear actuator, in proportion to the pressure oil from the upstream portion to the downstream portion of the oil passage 13a passing through the flow control valve. Control the flow rate. On the other hand, flow control mechanism
30b is interposed in the oil passage 13b connected between the oil passage 14a and the oil passage 15 extending from the reservoir R by the flow control valve thereof, and the flow control mechanism 30b includes the linear actuator. The flow rate of the pressure oil from the upstream portion to the downstream portion of the oil passage 13b passing through the flow rate control valve is controlled in proportion to the operation amount of the linear actuator that is proportional to the exciting current to the.

The flow control mechanism 40a uses the flow control valve to control the oil passage 1 and the oil passage 1 extending from the cylinder upper chamber of the shock absorber 10b.
The flow control mechanism 40a is interposed in an oil passage 16a connected to the flow control valve 4b, and the flow control mechanism 40a is proportional to the operation amount of the linear actuator proportional to the exciting current to the linear actuator. The flow rate of the pressure oil from the upstream portion to the downstream portion of the oil passage 16a passing through is controlled. On the other hand, the flow control mechanism 40
b is the flow control valve, and is interposed in the oil passage 16b connected between both oil passages 14b and 15, and the flow control mechanism 40b is
The flow rate of the pressure oil from the upstream portion to the downstream portion of the oil passage 16b passing through the flow rate control valve is controlled in proportion to the operation amount of the linear actuator which is proportional to the exciting current to the linear actuator.

The flow control mechanism 50a uses the flow control valve to control the oil passage 12 and the oil passage 1 extending from the cylinder upper chamber of the shock absorber 10c.
This flow rate control mechanism 50a is installed in an oil passage 18a connected to the flow rate control valve 50a, and is proportional to the operation amount of the linear actuator, which is proportional to the exciting current to the linear actuator. The flow rate of the pressure oil from the upstream portion to the downstream portion of the oil passage 18a passing through is controlled. On the other hand, the flow control mechanism 50
b is the flow control valve, and is interposed in the oil passage 18b connected between both oil passages 17a and 15, and the flow control mechanism 50b is
The flow rate of the pressure oil from the upstream portion to the downstream portion of the oil passage 18b passing through the flow rate control valve is controlled in proportion to the operation amount of the linear actuator which is proportional to the exciting current to the linear actuator.

The flow control mechanism 60a uses the flow control valve to control the oil passage 1
2 and an oil passage 19a connected between the oil passage 17b extending from the cylinder upper chamber of the shock absorber 10d.The flow rate control mechanism 60a is proportional to the exciting current to the linear actuator. The flow rate of the pressure oil from the upstream portion to the downstream portion to the oil passage 19a passing through the flow control valve is controlled in proportion to the operation amount of the linear actuator. On the other hand, the flow rate control mechanism 60b is interposed by the flow rate control valve in the oil passage 19b connected between the oil passages 17b and 15, and the flow rate control mechanism 60b
Controls the flow rate of the pressure oil from the upstream portion to the downstream portion of the oil passage 19b passing through the flow control valve in proportion to the operation amount of the linear actuator which is proportional to the exciting current to the linear actuator.

Next, the electric circuit configuration of the vehicle height control device will be described. The vehicle height sensors 70a, 70b, 70c and 70b are provided in the shock absorbers 10a, 10b, 10c and 10d, respectively, as shown in FIG. Each of these vehicle height sensors 70a
.About.70d detect the actual vehicle heights in the vicinity of the shock absorbers 10a-10d, respectively, and generate them as vehicle height detection signals. As shown in FIG. 3, the A / D converter 80 is connected to each of the vehicle height sensors 70a to 70d so as to be connected to each of the vehicle height sensors 70a to 70d.
The vehicle height detection signals from 0d are digitally converted and generated as first to fourth digital vehicle height signals. The vehicle speed sensor 90 detects the vehicle speed of the vehicle and generates a series of pulse signals at a frequency proportional to this. The waveform shaper 100 sequentially shapes each pulse signal from the vehicle speed sensor 90 to generate a rectangular wave signal.

The microcomputer 110 executes a computer program stored in its ROM in advance in cooperation with the AD converter 80 and the waveform shaper 100 according to the flowchart shown in FIG. 4, and controls each flow rate during the execution. Mechanism 30a-6
The arithmetic processing required to control the drive circuits 120a to 150b connected to the linear actuator 0b is performed. Under the control of the microcomputer 110, the drive circuits 120a to 150b respectively generate first to eighth drive signals representing an exciting current to be applied to the linear actuators of the flow rate control mechanisms 30a to 60b.

In the present embodiment configured as described above, when the device of the present invention is operating in the traveling state of the vehicle, for example, when the vehicle accelerates while making a large turn along a road surface having a large radius of curvature. , It is assumed that the body of the vehicle is tilted in the left-right direction by rolling. At this stage,
The computer program executed by the microcomputer 110 follows the steps shown in the flowchart in the figure.
Returning to 200, in the next step 210, the microcomputer 110 calculates the vehicle speed (hereinafter referred to as vehicle speed Vs) of the vehicle according to the rectangular wave signals sequentially generated by the waveform shaper 100 in cooperation with the vehicle speed sensor 90. . Then, in step 210, target vehicle heights A1, A2, A3 and A4 and vehicle speeds near the left front wheel, the right front wheel, the left rear wheel and the right rear wheel of the vehicle, which are stored in advance in the ROM of the microcomputer 110, are stored. The target vehicle heights A1 to A4 are determined according to the above-described calculated vehicle speed Vs from predetermined data representing the relationship with Vs. In such a case, in the predetermined data, each target vehicle height A1 to A4 has a predetermined value in the low speed region of the vehicle speed Vs, and a constant value smaller than the predetermined value in the high speed region of the vehicle speed Vs. It is designed to take

Then, in step 220, the microcomputer 110 sets the respective values of the first to fourth digital vehicle height signals generated by the cooperation of the vehicle height sensors 70a to 70d from the AD converter 80 to the respective current vehicle heights. Temporarily memorize as h1 ~ h4, step 230
In step 240, the current vehicle heights h1 to h4 are averaged and the averaged result is set as the average vehicle height H. In step 240, the target vehicle heights A1 to A1 in step 210 are calculated based on the following relational expression (1). The vehicle height differences D1 to D4 are calculated according to the current vehicle heights h1 to h4 in A4 and step 220.

Di = Ai-hi (where i = 1,2,3,4) (1) In this case, the relational expression (1) is the microcomputer 110.
It is stored in advance in the ROM. Then, after the calculation in step 240, the microcomputer 110
At a, main vehicle height differences P1 to P4 are calculated in accordance with vehicle height differences D1 to D4 in step 240 based on the following relational expression (2).

Pi = GiDi (however, i = 1,2,3,4) (2) In such a case, the symbol Gi represents the gain. The relational expression (2) is stored in advance in the ROM of the microcomputer 110.

When the computer program proceeds to step 250, the microcomputer 110 calculates the vehicle height differences d1 to d4 according to the average vehicle height H at step 230 and the current vehicle heights h1 to h4 at step 220 based on the following relational expression (3). Calculate

di = H-hi (however, i = 1,2,3,4) (3) In such a case, the relational expression (3) is the microcomputer 110.
It is stored in advance in the ROM. Then, in step 250a, the microcomputer 110 calculates each auxiliary vehicle height difference Q1 to Q4 according to each vehicle height difference d1 to d4 in step 250 based on the following relational expression (4).

Qi = gidi (however, i = 1,2,3,4) (4) In this case, the code gi represents the gain. The relational expression (4) is stored in advance in the ROM of the microcomputer 110. Then the computer program proceeds to step 260.
Then, the microcomputer 110 uses the following relational expression (5) to determine the corrected main vehicle height differences L1 to L4 according to the main vehicle height differences P1 to P4 at step 240a and the auxiliary vehicle height differences Q1 to Q4 at step 250a. Calculate L4.

Li = Pi + Qi (where i = 1,2,3,4) (5) In this case, the relational expression (5) is the microcomputer 110.
It is stored in advance in the ROM.

However, as described above, the vehicle body leans in the left-right direction due to rolling, so if the leaning of this vehicle body decreases from the left side to the right side, both current vehicle heights h1 and h3 in step 220 are the average vehicle in step 230. It is considered that the vehicle height is higher than the high H, while both the current vehicle heights h2 and h4 in step 220 are lower than the average vehicle height in step 230.
Therefore, both vehicle height differences d1 and d3 in step 250 (that is, both auxiliary vehicle height differences Q1 and Q3 in step 250a) are both negative, while both vehicle height differences d2 and d4 in step 250 (that is,
Both auxiliary vehicle height differences Q2 and Q3 in step 250a become positive. Furthermore, under such conditions, the step
A state occurs in which the vehicle height differences D1 to D4 in 240 (that is, the main vehicle height differences P1 to P4 in step 240a) are both positive (or negative).

Under the above conditions, the corrected main vehicle height difference L1 in step 260 is positive when Q1 <0, P1> 0, and the corrected main vehicle height difference L2 is positive when Q2> 0, P2> 0. If the corrected main vehicle height difference L3 is positive when Q3 <0, P3> 0 and the corrected main vehicle height difference L4 is positive when Q4> 0, P4> 0, the microcomputer 110 In step 270, it is determined to be “YES” based on L1> 0, and in step 270a, the corrected main vehicle height difference L1
Is generated as the first output signal to be given to the drive circuit 120a, and the second output signal to be given to the drive circuit 120b is maintained in the extinguished state in step 270b.

Then, in step 280, the microcomputer 110 determines “YES” based on L2> 0, and in step 280a, outputs the absolute value of the corrected main vehicle height difference L2 to the drive circuit 130a. Then, in step 280b, the fourth output signal to be given to the drive circuit 130b is maintained in the extinguished state, and in step 290, it is determined to be “YES” based on L3> 0,
At step 290a, the absolute value of the corrected main vehicle height difference L3 is set to the drive circuit.
Generated as a fifth output signal to be applied to 140a,
At 290b, the sixth output signal to be given to the drive circuit 140b is maintained in the extinguished state, and at step 300, it is determined to be "YES" based on L4> 0, and at step 300a, the corrected main vehicle height difference is determined. L4
Is generated as the seventh output signal to be given to the drive circuit 150a, and in step 300b, the eighth output signal to be given to the drive circuit 150b is maintained in the extinguished state.

As described above, the microcomputer 110 has the second, fourth, sixth
When the first, third, fifth and seventh output signals are generated in the extinguished state with the eighth and eighth output signals, the respective drive circuits 120a, 130a, 140a are generated.
And 150a denote the respective exciting currents corresponding to the respective values of the first, third, fifth, and seventh output signals as the first, third, fifth, and seventh drive signals, and the respective drive circuits 120b, Occurs under each extinction of the second, fourth, sixth and eighth drive signals from 130b, 140b and 150b. Then, when the flow rate control valve of the flow rate control mechanism 30a is in the fully closed state of the flow rate control valve of the flow rate control mechanism 30b, the drive circuit 1
Flow control mechanism 30a proportional to the value of the first drive signal from 20a
Of the hydraulic pump P and accumulator Acc with a flow rate corresponding to the operation amount of the linear actuator of
The pressure oil applied through 13a is applied to the upper chamber of the shock absorber 10a through the oil passage 14a. As a result, the shock absorber 10a raises the current vehicle height h1 toward the target vehicle height A1 at an adjusting speed according to the amount of pressure oil to the upper chamber.

Further, the flow rate control valve of the flow rate control mechanism 40a is
From the hydraulic pump P and the accumulator Acc with the flow rate corresponding to the operation amount of the linear actuator of the flow rate control mechanism 40a that is proportional to the value of the third drive signal from the drive circuit 130a when the flow rate control valve of 0b is fully closed. The pressure oil applied through the oil passages 12 and 16a is passed through the oil passage 14b to the shock absorber 10b.
To the upper chamber. As a result, the shock absorber 10b raises the current vehicle height h2 toward the target vehicle height A2 at an adjustment speed according to the amount of pressure oil to the upper chamber.

Further, the flow control valve of the flow control mechanism 50a is
From the hydraulic pump P and the accumulator Acc with the flow rate corresponding to the operation amount of the linear actuator of the flow rate control mechanism 50a which is proportional to the value of the fifth drive signal from the drive circuit 140a when the flow rate control valve of 0b is fully closed. The pressure oil applied through the oil passages 12 and 18a is passed through the oil passage 17a to the shock absorber 10c.
To the upper chamber. As a result, the shock absorber 10c raises the current vehicle height h3 toward the target vehicle height A3 at an adjusting speed according to the amount of pressure oil to the upper chamber.

Further, when the flow control valve of the flow control mechanism 60a is in the fully closed state of the flow control valve of the flow control mechanism 60b, the operation of the linear actuator of the flow control mechanism 60a which is proportional to the value of the seventh drive signal from the drive circuit 150a. Pressure oil applied from the hydraulic pump P and the accumulator Acc through the oil passages 12 and 19a is applied to the upper chamber of the shock absorber 10d through the oil passage 17b with a flow rate corresponding to the amount. As a result, the shock absorber 10d raises the current vehicle height h4 toward the target vehicle height A4 at an adjusting speed according to the amount of pressure oil to the upper chamber.

As can be understood from the above description, when the vehicle body is inclined so as to decrease from the left side to the right side,
When the main vehicle height differences P1 to P4 and the corrected main vehicle height differences L1 to L4 are both positive, the corrected vehicle height differences L1 and L3 (that is, the excitation of the linear actuators of both flow rate control mechanisms 30a and 50a to the linear actuators) are performed. Current)
However, only the absolute value of each auxiliary vehicle height difference Q1, Q3, each main vehicle height difference P1, P3
Each of the corrected main vehicle height differences L2, L4 (that is, the exciting currents to the linear actuators of both flow rate control mechanisms 40a, 60a) is determined to be smaller than the absolute value of each auxiliary vehicle height difference Q1, Q4. , The main vehicle height difference P2, P4 is determined to be respectively larger, the vehicle height control degree of each shock absorber 10b, 10d in each relation with Q2> 0, Q4> 0 is Q1 <0, Q3 <0.
It becomes larger than the vehicle height control degree of each shock absorber 10a, 10c in each relation with. This means that the vehicle height control is performed while reducing the downward inclination of the vehicle body from the left side to the right side. In other words, the correction control for the inclination of the vehicle body as described above is promptly performed together with the vehicle height control, and as a result, the riding comfort and the maneuverability of the vehicle can always be sufficiently ensured.

Further, under the conditions as described above, when the corrected main vehicle height difference L1 in step 260 is Q1 <0, P1 <0, it becomes negative,
The corrected main vehicle height difference L2 becomes negative when Q2> 0, P2 <0, the corrected main vehicle height difference 13 becomes negative when Q3 <0, P3 <0, and the corrected main vehicle height difference L4 is Q4> When 0, P4 <0, when it becomes negative,
In step 270, the microcomputer 110 sets L1 <0.
It is determined to be "NO" based on the above, and in step 270c, the absolute value of the corrected main vehicle height difference L1 is generated as the second output signal, and in step 27
At 0d, the first output signal is maintained in the extinguished state.

Then, in step 280, the microcomputer 110 determines “NO” based on L2 <0, and in step 280c,
Generate the absolute value of the modified main vehicle height difference L2 as the fourth output signal,
In step 280d, maintain the third output signal in the extinguished state,
In step 290, it is determined to be "NO" based on L3 <0, in step 290c the absolute value of the corrected main vehicle height difference L3 is generated as the sixth output signal, and in step 290d the fifth output signal is output. In the extinction state, and in step 300, based on L4 <0, "N
"O", the absolute value of the corrected main vehicle height difference L4 is generated as the eighth output signal in step 300c, and in step 300d,
The seventh output signal is maintained in the extinguished state.

As described above, the microcomputer 110 has the first, third, fifth
When the second, fourth, sixth and eighth output signals are generated in the extinguished state of the seventh and seventh output signals, the drive circuits 120b, 130b, 140b are generated.
And 150b are drive circuits 120a and 130a, respectively, which use the respective exciting currents corresponding to the respective values of the second, fourth, sixth and eighth output signals as the second, fourth, sixth and eighth drive signals. , 140a and 150a from the first, third, fifth and seventh drive signals, respectively. Then, when the flow control valve of the flow control mechanism 30b is in the fully closed state of the flow control valve of the flow control mechanism 30a, the drive circuit 1
Flow control mechanism 30b proportional to the value of the second drive signal from 20b
Pressure oil from the upper chamber of the shock absorber 10a with a flow rate corresponding to the operation amount of the linear actuator of
It is discharged into the reservoir R through 4a, 13b and 15. As a result, the shock absorber 10a reduces the current vehicle height h1 toward the target vehicle height A1 at an adjusting speed according to the amount of pressure oil discharged from the upper chamber.

In addition, the flow rate control valve of the flow rate control mechanism 40b is
From the upper chamber of the shock absorber 10b, with the flow rate corresponding to the operation amount of the linear actuator of the flow rate control mechanism 40b proportional to the value of the fourth drive signal from the drive circuit 130b when the flow rate control valve of 0a is fully closed. Pressure oil of each oil passage 14b, 16b and
It is passed through 15 and discharged into the reservoir R. As a result, the shock absorber 10b reduces the current vehicle height h2 toward the target vehicle height A2 at the adjustment speed according to the amount of pressure oil discharged from the upper chamber.

In addition, the flow control valve of the flow control mechanism 50b is
With the flow control valve of 0a fully closed, the flow rate corresponding to the operation amount of the linear actuator of the flow rate control mechanism 50b, which is proportional to the value of the sixth drive signal from the drive circuit 140b, is applied from the upper chamber of the shock absorber 10c. Pressure oil of each oil passage 17a, 18b and
It is passed through 15 and discharged into the reservoir R. As a result, the shock absorber 10c reduces the current vehicle height h3 toward the target vehicle height A3 at an adjusting speed according to the amount of pressure oil discharged from the upper chamber.

Further, the flow control valve of the flow control mechanism 60b operates the linear actuator of the flow control mechanism 30b which is proportional to the value of the eighth drive signal from the drive circuit 150b when the flow control valve of the flow control mechanism 60a is fully closed. The pressure oil from the upper chamber of the shock absorber 10d is supplied to each of the oil passages 17b and 19b at a flow rate corresponding to the amount.
And 15, and discharge into the reservoir R. As a result, the shock absorber 10d lowers the current vehicle height h4 toward the target vehicle height A4 at an adjustment speed according to the amount of pressure oil discharged from the upper chamber.

As can be understood from the above description, when the main vehicle height difference P1 to P4 and the corrected main vehicle height differences L1 to L4 are both negative in the case where the vehicle body is inclined so as to decrease from the left side to the right side, Each modified main vehicle height difference L1, L3 (that is, exciting current to each linear actuator of both flow rate control mechanisms 30b, 50b)
However, only the absolute value of each auxiliary vehicle height difference Q1, Q3, each main vehicle height difference P1, P3
The corrected main vehicle height difference L2, L4 (that is, the exciting current to the linear actuators of both flow rate control mechanisms 40b, 60b) is determined to be larger than the absolute value of each auxiliary vehicle height difference Q.
Only the absolute value of 2, Q4 is determined to be smaller than the absolute value of each main vehicle height difference P2, P4, so the vehicle height control of each shock absorber 10a, 10c in each relation with Q1 <0, Q3 <0 The degree is greater than the vehicle height control degree of each shock absorber 10b, 10d in each relation of Q2> 0, Q4> 0. This means that the vehicle height control is performed while reducing the downward inclination of the vehicle body from the left side to the right side. In other words, the correction control for the inclination of the vehicle body as described above is promptly performed together with the vehicle height control, and as a result, the riding comfort and the maneuverability of the vehicle can always be sufficiently ensured.

In the above operation, the case where the vehicle body is inclined so as to decrease from the left side to the right side due to rolling has been described, but the present invention is not limited to this, and when the vehicle body is inclined so as to decrease from the right side to the left side due to rolling,
Alternatively, even when the vehicle body is tilted in the front-rear direction due to pitching, it is possible to achieve substantially the same effect as the above. Further, when the respective corrected main vehicle height differences L1 to L4 obtained in step 260 become zero, the microcomputer 110 causes each step 270,270a, 270b, 280,280a, 280b, 290,290a, 290b, 300,30.
The calculation passing through 0a and 300b is performed in the same manner as described above. In such a case, the respective values of the first, third, fifth and seventh output signals generated in the respective steps 270a, 280a, 290a and 300a are L1 = 0, L2 =
The flow control valves of the flow control mechanisms 30a, 40a, 50a and 60a are fully closed together with the flow control valves of the flow control mechanisms 30b, 40b, 50b and 60b because they are specified by 0, L3 = 0 and L4 = 0 respectively. Then, the current vehicle height of the vehicle body is maintained at the target vehicle height.

[Brief description of drawings]

FIG. 1 is a diagram corresponding to the configuration of the invention described in the claims, FIGS. 2 and 3 are overall configuration diagrams showing an embodiment of the present invention, and FIG. 4 is a diagram of the microcomputer in FIG. It is a flow chart which shows an operation. Explanation of symbols P …… hydraulic pump, 10a-10d …… shock absorber,
30a-60b ... Flow rate control mechanism, 70a-70d ... Vehicle height sensor,
110 ... Microcomputer, 120a-150b ... Drive circuit.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Susumu Ohashi 1-1, Showa-cho, Kariya city, Aichi Nihon Denso Co., Ltd. (56) References JP-A-60-92915 (JP, A)

Claims (1)

[Claims] 1. In a vehicle having first, second, ..., Nth wheels, actual vehicle heights near the first, second, ..., Nth wheels are detected respectively. , Nth vehicle height detection means generated as first, second, ..., Nth vehicle height detection signals, and a target vehicle in the vicinity of the first wheel. The difference between the height and the value of the first vehicle height detection signal, the difference between the target vehicle height near the second wheel and the value of the second vehicle height detection signal, ..., The nth Main vehicle height difference calculating means for calculating the difference between the target vehicle height near the wheels and the value of the n-th vehicle height detection signal as the first, second, ..., Nth vehicle height differences, respectively. Average vehicle height determining means for averaging the respective values of the first, second, ..., Nth detection signals to determine the average vehicle height, the average vehicle height and the first vehicle height detection signal Difference from the value of the average car The difference between the height and the value of the second vehicle height detection signal, ...
Auxiliary vehicle height difference calculating means for calculating a difference between the average vehicle height and a value of the n-th vehicle height detection signal as a first, second, ..., Nth auxiliary vehicle height difference, respectively. , 2nd, ..., The nth calculation main vehicle height difference is the 1st, 2nd, ..., 1st necessary to reduce the inclination of the vehicle body in accordance with the nth calculation auxiliary vehicle height difference, Correction means for respectively correcting the second, n-th corrected main vehicle height difference, and adjusting speeds corresponding to the first, second, ..., nth corrected main vehicle height differences, The first, second, ... Adjusting the actual vehicle heights near the first, second, ..., Nth wheels, respectively.
.., A vehicle height control device characterized in that the nth adjusting means is provided.