JPH01153316A - Car height regulator - Google Patents

Abstract

PURPOSE:To improve running stability at a car height regulator by means of the feed/discharge of pressure air, by, at the time of car height regulation by means of the feed/discharge of air from a compressor, arranging so that car height regulation control may be interrupted when centrifugal force which is more than a predetermined one is acting on. CONSTITUTION:Car heights from right and left and front and rear car height sensors RR-RL, a car speed from a car speed sensor SS, a steering wheel turning angle from a turning angle sensor HS, are respectively inputted at a control circuit ECU. The ECU calculates the average car height according to a predeter mined procedure, and selects a target car height. And when car heights are wide of the target car height, car heights are regulated by controlling respective solenoid valves VFR-VRL and by feeding/discharging pressure air from a com pressor CP to respective air suspensions EFR-ERL. At this time, centrifugal force is calculated from the detected turning angle and car speed, and when centrifugal force is more than a predetermined value, car height regulation is interrupted. As a result, a stable travel can be done even if entered into a high speed way immediately from the slope portion of an interchange.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vehicle height adjustment device, and particularly to a vehicle height adjustment device that improves running stability.

P6 [Prior Art] Generally, in a vehicle, a suspension device is disposed between the axle and the vehicle body in order to prevent vibrations of the axle from being transmitted to the vehicle body. For this reason, when the vehicle weight increases, the vehicle body sinks, and when the vehicle weight becomes lighter, the vehicle body rises. Also, when braking suddenly, the front of the car sinks, the rear of the car sinks when going uphill, and the front of the car sinks when going downhill.

Therefore, in the past, a vehicle height sensor was installed between the axle and the vehicle body to detect the vehicle height, and the air pressure of the shock absorber of the suspension system was adjusted so that the detected vehicle height was within a predetermined range. X (e.g., U.S. Pat. No. 410,521)
Specification No. 6: 1978 CL 280).

As a specific configuration of this type of vehicle height adjustment device,
The technology published in Publication No.-140317 will be explained.

The technology disclosed in the above publication includes a vehicle height sensor that detects the distance between the vehicle body and the axle, a signal comparison circuit that receives signals from the vehicle height sensor and divides the vehicle height detection area into multiple areas, and multiple A pulse conversion circuit converts a signal divided into regions into a pulse signal, an integration circuit integrates pulse signals in multiple regions within a certain period of time, and the signals integrated by the integration circuit are input, and the vehicle height is calculated. a comparison judgment circuit that judges
The system is constructed with a fluid circuit that controls the supply and discharge of the suspension system based on this determination.

With this configuration, the vehicle height while traveling can be selectively controlled to an arbitrary vehicle height, and changes in cargo while the vehicle is stopped,
Vehicle height control is performed in response to changes in vehicle height due to people getting on and off the vehicle.

[Problems to be Solved by the Invention] In the conventional vehicle height adjustment device as described above, vehicle height adjustment control was performed using a vehicle height sensor, so as shown in the explanatory diagram of FIG. 11 showing a curved driving state, For example, when driving on a long curve such as an interchange slope,
A centrifugal force is applied in a direction perpendicular to the direction of travel of the vehicle. When such a centrifugal force is applied, the load on the suspension device in the outer circumferential direction of the vehicle becomes large, resulting in the same result as a single load, and the suspension device of the wheel on the outer circumferential side sinks. At this time, the vehicle height sensor of the wheel located on the outer circumferential side detects that the vehicle height is lowered, and adjusts to raise the vehicle height of the wheel located on the outer circumferential side.

Therefore, when the vehicle is traveling on a long curve such as an interchange slope, the vehicle height of the wheels on the outer circumferential side is raised, and the vehicle travels around the curve with the vehicle height balanced.

However, if the vehicle were to immediately start driving in a straight line, for example, on a highway, in this state, the vehicle would have to travel for a while with the vehicle body tilted, and it is predicted that problems would arise in the running stability of the vehicle.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and is to provide a vehicle height adjustment device that can maintain a predetermined balanced vehicle height without losing driving stability when driving in a straight line from driving on a curve. The challenge is to provide this information.

[Means for Solving the Problems] The vehicle height adjustment device according to the present invention is a vehicle in which the vehicle height output of the vehicle height sensor that detects the height between the axle and the vehicle body brings the vehicle body into a predetermined vehicle height state. When the vehicle moves out of the predetermined target vehicle height range selected by the vehicle height selection means, fluid pressure is supplied from the compressor to the suspension installed at each wheel or from the suspension. The vehicle height adjustment control is performed by controlling the opening and closing of a valve means for controlling the discharge of the fluid pressure of the vehicle, and the vehicle height adjustment control is interrupted when a centrifugal force exceeding a predetermined value is applied.

[Operations] In the present invention, a vehicle height sensor detects the height between the axle and the vehicle body as the vehicle height. Further, a vehicle height selection means selects a target vehicle height that defines a vehicle height range in which the vehicle body is brought into a predetermined vehicle height state. When the vehicle height output of the vehicle height sensor deviates from the predetermined target vehicle height range selected by the vehicle height selection means, the fluid pressure from the compressor is controlled to be supplied to the suspension disposed on each wheel, or the suspension is Vehicle height adjustment control is performed by controlling the opening and closing of a valve means that controls the discharge of fluid pressure from the vehicle. At this time, if a centrifugal force exceeding a predetermined value is applied to the vehicle, the vehicle height adjustment control is interrupted.

Therefore, even if the vehicle goes straight from driving on a curve such as an interchange slope to straight driving on an expressway, a predetermined balanced vehicle height can be maintained without losing driving stability.

[Example] Examples of the present invention will now be described.

FIG. 1 is a configuration diagram of a fluid control system and an electrical control system of a vehicle height adjustment device according to an embodiment of the present invention, and FIG. 2 is an explanatory diagram showing a schematic configuration of a vehicle height adjustment device according to an embodiment of the present invention. be.

In the figure, the control circuit ECU is composed of a microcomputer, etc., and is program-controlled.

The vehicle speed sensor SS is a detector used as a speedometer that detects the traveling speed of the vehicle as the reciprocal of the pulse period. The rotation angle sensor H8 detects the rotation of the steering wheel, and uses a specific code to detect the rotation angle of the steering wheel used in the power steering device. The compressor CP is a fluid pressure supply source rotated by the motor M, and is driven by controlling the motor drive relay RY with the output of the control circuit ECLI. The dryer DR is a fluid pressure supply source, the compressor CP.
From the suspension system, right front wheel air suspension EFR, left front wheel air suspension EFL, right rear wheel air suspension ERR.

This removes the humidity of the fluid supplied to the left rear wheel air suspension ERL. The exhaust solenoid valve EX is the right front wheel air suspension EFR.

The fluid pressure of the left front air suspension EFL, the right rear air suspension ERR, and the left rear air suspension ERL is discharged by the output of the control circuit ECLJ.It opens when the vehicle height is lowered and is closed under normal conditions. It has become.

The low vehicle height selection switch LOWS W, the intermediate vehicle height selection switch NORMAL SW, and the high vehicle height selection switch HIGH3W are vehicle height selection switches that select three levels of vehicle height, and set the vehicle body BO to a predetermined vehicle height state. A vehicle height selection means is configured to select a target vehicle height that defines a range of vehicle heights.

The right front wheel height sensor FR is a detector that detects the height between the right front wheel's axle (not shown) and the vehicle body 80 as a predetermined gray code. Vehicle body B is located between the axle and the vehicle body 80.
Right front wheel air suspension EFR, the suspension system that supports O
The vehicle height is controlled by the supplied air pressure. The front right air suspension valve VFR is a valve that controls the supply of fluid pressure from the compressor CP to the front right air suspension EFR.

Further, the left front wheel height sensor FL is a detector that detects the height between the left front wheel axle and the vehicle body BO as a predetermined code. The front left wheel air suspension EFL, which is located between the axle and the vehicle body BO and supports the vehicle body 80, controls its vehicle height by supplied air pressure. The front left wheel solenoid valve VFL is the front left wheel air suspension EFL.
This valve controls the supply of fluid pressure from the compressor CP to the compressor CP.

Similarly, the right rear wheel height sensor RR is a detector that detects the height between the right rear wheel axle (not shown) and the vehicle body BO as a predetermined code. The right rear wheel air suspension ERR, which is located between the axle and the vehicle body BO and supports the vehicle body BO, controls its vehicle height by supplied air pressure. The right rear wheel air suspension valve VRR is a valve that controls the supply of fluid pressure from the compressor CP to the right rear wheel air suspension ERR.

Further, the left rear wheel height sensor RL is a detector that detects the height between the left rear wheel axle and the vehicle body BO as a predetermined code. The left rear air suspension ERL, which is located between the axle and the vehicle body BO and supports the vehicle body BO, controls its vehicle height by supplied air pressure. The left rear wheel solenoid valve VRL is the left rear wheel air suspension ERL.
A valve controls the supply of fluid pressure from the compressor CP to the compressor CP.

The vehicle height adjustment device of this embodiment configured as described above is controlled as follows.

3 to 6 are flowcharts for controlling the main program of the control circuit ECLI of the vehicle height adjusting device according to an embodiment of the present invention.

This program starts control by turning on an ignition switch (not shown).

First, in step S1, the RAM and output port used when executing this program are initialized. At this time, each front right wheel up request flag and right front wheel down request flag,
Lower the left front wheel up request flag, the left front wheel down request flag, the right rear wheel up request flag, the right rear wheel down request flag, the left rear wheel up request flag, and the left rear wheel down request flag.
In step S2, an interrupt permission flag is set (set as "1 pass"). In step S3, it is determined that the processing timing has arrived, and when the predetermined processing timing has arrived,
In step S4, right front wheel height sensor FR → left rear wheel height sensor RL → left front wheel height sensor FL → right rear wheel height sensor RR
calls a data input routine that reads the vehicle height of the four wheels in rotation. This data input routine uses the outputs of the right front wheel height sensor FR1, the left rear wheel height sensor RL, the left front wheel height sensor FL, and the right rear wheel height sensor RR as serial signals, so the vehicle height of the four wheels is adjusted in rotation. However, the vehicle height of the four wheels may also be read at the same time. In step S5, the timing of vehicle speed calculation is determined, and when it is the timing of vehicle speed calculation, in step S6, the pulse period of vehicle speed detection performed by a known interrupt routine, the explanation of which is omitted here, is read out, and the pulse period input from the vehicle speed sensor SS is read out. The average vehicle speed is calculated by multiplying the reciprocal of the period by the count. Further, in step S7, it is determined whether it is the timing to divide the vehicle height, and when it is the timing to calculate the vehicle height, the vehicle height is calculated in step S8. This vehicle height calculation converts the gray code output of each right front wheel height sensor FR1, left rear wheel height sensor RL, left front wheel height sensor FL, and right rear wheel height sensor RR into binary code,
Stock up on data from the past eight or so times and calculate the average vehicle height.

In step S9, it is determined from the ignition signal or the engine revolution meter whether the engine is currently rotating. When stopped, all solenoid valves, namely, right front wheel solenoid valve VFR1 left front solenoid valve V
FL, the right rear wheel solenoid valve VRR, and the left rear wheel solenoid valve VRL are closed, and the drive of the motor M is brought to a halt state in order to bring the compressor CP to a halt state.

When it is determined in step S9 that the engine is currently rotating, a target vehicle height is selected in step 810.

This target vehicle height is based on vehicle speed data, vehicle height selection switch low vehicle height selection switch L OWS W, intermediate vehicle height selection switch NORMAL SW, or high vehicle height selection switch H
From the target vehicle height map created from the road driving conditions based on the IGH3W input, the difference between the maximum and minimum vehicle height sensor values, input vehicle speed data, input the vehicle height selection switch, and calculate the maximum and minimum vehicle height sensor values. A predetermined target vehicle height is selected by input.

In step 811, the right front wheel lift request flag is set, and in step 3
Check the right front wheel lowering request flag at step 12. At the beginning of this routine, the right front wheel up request flag and the right front wheel down request flag are off (“O11”), so the calculated vehicle height calculated as the averaged vehicle height in step S8 in step 315 is In step 310, it is determined whether the calculated vehicle height is greater than or equal to the maximum value of the selected target vehicle height.When the calculated vehicle height is greater than or equal to the maximum value of the target vehicle height, a right front wheel elevation request flag is set in step 316 (set to "1"). , step S1
In step 7, it is determined whether the calculated vehicle height is less than or equal to the minimum value of the target vehicle height. When the calculated vehicle height is less than the minimum value of the target vehicle height, step 3
At 18, set the right front wheel lowering request flag (set it to “1”)
.

From next time onwards, if the routine from step 311 to step 318 is entered, step S16 will be executed in step S11.
In step S12, the right front wheel lift request flag is set (set to "'1") at step S12 and set at step 318 ("°1").

) Look at the right front wheel lowering request flag and see if the right front wheel raising request flag or right front wheel lowering request flag is set (“1”).
''), the target vehicle height is compared in step 313 with the h1 calculated vehicle height calculated as the averaged vehicle height in step S8.If the target vehicle height and the reduced vehicle height do not match in step 313, the predetermined output is In order to continue, step 3
The process moves to step 21. When the target vehicle height and the divided vehicle height match in step S13, it means that the vehicle height adjustment control has been completed.
The right front wheel lift request flag was set (set to "1") in Step 16, or the right front wheel lift request flag was set (set to "1") in Step 31B.
Lower the right front wheel lowering request flag (set to "1") (1g
OWe).

Further, in step 321, the left front wheel raising request flag is checked, and in step 322, the left front wheel lowering request flag is checked. At the beginning of this routine, the front left wheel raise request flag and the front left wheel lower request flag are down ("Ott"), so in step S25 the calculated vehicle height calculated in step S8 is the target selected in step S10. It is determined whether the vehicle height is greater than or equal to the maximum value of the vehicle height. When the reduced vehicle height is greater than or equal to the maximum value of the target vehicle height, a left front wheel raising request flag is set (set to "1") in step S26. Also, the flag is calculated in step S27. It is determined whether the vehicle height is below the minimum value of the target vehicle height. When the calculated vehicle height is below the minimum value of the target vehicle height, a left front wheel lowering request flag is set (set to "1") at step 828.

From next time onwards, if the routine from step S21 to step 328 is entered, step 326 will be executed at step 321.
In step S22, the left front wheel lift request flag is set (set to "1") at step S22, and the left front wheel lowered request flag is set at step 328 (it is set to 11T). When the lowering request flag is set (“1”), the target vehicle height is compared in step 323 with the calculated vehicle height calculated as the averaged vehicle height in step S8.Step S23
If the target vehicle height and the calculated vehicle height do not match, the process proceeds to step 331 because it is necessary to continue to perform a predetermined output. When the target vehicle height and the calculated vehicle height match in step 323, it means that the vehicle height adjustment control has been completed, and therefore, in step S24, the left front wheel lift request set in step 826 (set to "1") flag or the left front wheel lowering request flag set (set to 1'') in step 328 (Ote
).

Similarly, for the right rear wheel, in steps 331 to 338, and for the left rear wheel, in steps S41 to 34B, the right rear wheel rise request flag or the right rear wheel lowering request flag, the left rear wheel rise request flag, or the left rear wheel Raise or lower the wheel lowering request flag.

In this way, the need to change the vehicle height of the four wheels of the vehicle is determined by the right front wheel up request flag or right front wheel down request flag, the left front wheel up request flag or left front wheel down request flag, and the right rear wheel up request flag, respectively. or right rear wheel lowering request flag,
The information is stored by setting or lowering the left rear wheel up request flag or the left rear wheel down request flag.

Then, in step 351, all request flags are set, namely, right front wheel up request flag, right front wheel down request flag, left front wheel up request flag, left front wheel down request flag, right rear wheel up request flag, right rear wheel down request flag, right front wheel down request flag, Both the rear wheel up request flag and the left rear wheel down request flag are down (“OIT”).
), the routine starts from repeat step S3.

When any one of the all request flags is set (“1'') in step 851, the current vehicle speed input from the vehicle speed sensor SS and calculated in step S6 and the rotation of the steering wheel are determined in step 852. The "centrifugal force area h1 calculation routine" shown in Fig. 7 or 8 calculates the centrifugal force from the rotation angle sensor H3 to be detected using the centrifugal force or formula shown in Fig. 9 (a) or (b). Start processing.

In this "centrifugal force area calculation routine", for example, in the case of the centrifugal force detection characteristic diagram in FIG. 9(a), if the steering wheel rotation angle θ, which is the output of the rotation angle sensor H3, is 18 degrees or less, , the inside of the control region is determined regardless of the output V of the vehicle speed sensor SS.

Further, even when the output V of the vehicle speed sensor SS is 40 km/h or less, the inside of the control region is determined regardless of the steering wheel rotation angle θ of the rotation angle sensor H3. Then, the output V of the vehicle speed sensor SS exceeds 4 Q Km/h and 5 Q
When the speed is less than Km/h, the steering wheel rotation angle θ
is θ≦-3.6V+288 Furthermore, the output of the vehicle speed sensor SS exceeds 60 Km/h and 1
When the steering wheel rotation angle θ is less than or equal to QQKm/h, if the steering wheel rotation angle θ is θ≦−1, 35V+153, it is determined that the division result is within the control region.

This is processed according to the "centrifugal force area calculation routine" shown in FIG.

First, in step 361, the output V of the vehicle speed center SS is set to 40.
Km/h or less, the control interruption flag is lowered in step 365 (set to "091"). In step 362, the output V of the vehicle speed sensor SS is higher than 40 Km/h < 60 Km
/h or less, θ>-3,6V+2 in step 367
88, a control interruption flag is set in step 368 (“
1"). Also, when θ≦-3.6V+288, the control interruption flag is lowered in step 365 (O
tp). When the output V of the vehicle speed sensor SS is greater than 60 Km/h and less than 1100 Km/h in step 363, and when θ>-1.35V+153 in step S66, a control interruption flag is set in step 368 ("
1 pa). Also, when θ≦-1, 35V+153, the control interruption flag is lowered in step 365 (“
0'').Then, the output V of the vehicle speed sensor SS is 10
0 m/h, when θ>18 in step S64, a control interruption flag is set (“1”) in step 368.
When θ≦18, the control interruption flag is lowered (set to “O′”) in step 365.

In addition, in the case of the centrifugal force detection characteristic diagram shown in FIG. 9(b), the steering wheel rotation angle θ, which is the output of the rotation angle sensor H3 that detects rotation of the steering wheel, is 3.
At 6 degrees or less, the control region is determined regardless of the output V of the vehicle speed sensor SS.

Further, even when the output V of the vehicle speed sensor SS is 20 km/h or less, the inside of the control region is determined regardless of the steering wheel rotation angle θ of the rotation angle sensor H3. When the output V of the vehicle speed sensor SS is more than 20 m/h and less than 1100 K/h, if the steering wheel rotation angle θ is θ≦-1,8V+216, it is determined that the calculation result is in the control region. Ru.

This is processed according to the "centrifugal force area calculation routine" shown in FIG.

First, in step 371, the output V of the vehicle speed sensor SS is set to 2Q.
Km/h or less, the control interruption flag is lowered (set to "0'') in step 374. In step S72, the output V of the vehicle speed sensor SS is higher than 20 Km/h<100K.
m/h or less, θ>-1,8V+ in step 375
216, a control interruption flag is set in step 376 (“
1"). Also, when θ≦-1,8V+216, the control interruption flag is lowered in step 374 ("
Ott). Then, the output ■ of the vehicle speed sensor SS is 1
When higher than 100K/h, θ>36 in step S73.
, the control interruption flag is set (“1”) in step 876.
When θ≦36, the control interruption flag is lowered (set to “O”) in step 374.

In this way, in step 352, the current vehicle speed calculated in step S6 and the steering wheel rotation angle θ of the rotation angle sensor H3 are used to determine whether the control area or the control interruption area is in the control area, and in step 353, the state of the control interruption flag is determined. look,
Determine whether the control interruption flag is off (“Ott”), and when the control interruption flag is off (“Ott”),
In step S55, the right front wheel up request flag, the right front wheel down request flag, the left front wheel up request flag, the left front wheel down request flag, the right rear wheel up request flag, the right rear wheel down request flag, the left rear wheel up request flag, the left rear wheel up request flag, In response to a request flag such as a wheel lowering request flag, the compressor CP is operated, or in a stopped state, the right front wheel solenoid valve VFR, the left front wheel solenoid valve VFL1, the right rear wheel solenoid valve VRR.
, the left rear wheel solenoid valve VRL is opened, and the exhaust solenoid valve EX is opened as required. That is, according to the output state specification diagram shown in FIG.
Drives P and opens and closes solenoid valves.

At step 353, the control interruption flag is set (“1°
'), in step 354, all the solenoid valves, ie, the front right solenoid valve VFR, the front left solenoid valve VFL, and the rear right solenoid valve VRR.
, the left rear wheel solenoid valve VRL and the exhaust solenoid valve EX are closed, and the drive of the motor M is brought to a halt state in order to bring the compressor CP to a halt state.

As described above, the vehicle height adjustment device of this embodiment uses the right front wheel height sensor "R1 left rear wheel height sensor RL", which is installed on the vehicle to detect the height between the axle and the vehicle body BO. High sensor F
Vehicle height sensors such as L, right rear wheel vehicle height sensor RR, right front wheel air suspension EFR1 installed on each wheel, left front wheel air suspension EFL, right rear wheel air suspension ER
Right front wheel solenoid valve VFR, left front wheel solenoid valve VFL, right rear wheel solenoid valve that supplies fluid pressure from compressor CP to suspensions such as R, left air suspension ERL, and controls Th1J or discharges fluid pressure from the suspension. VRR1 Valve means such as the left rear wheel solenoid valve VRL and the exhaust solenoid valve EX, and a low vehicle height selection switch L that selects a target vehicle height that defines a vehicle height range that brings the vehicle body BO into a predetermined vehicle height state.
OWS W, intermediate vehicle height selection switch NORMAL SW
, high vehicle height selection switch HIGH3W to select the vehicle height, vehicle speed data input, vehicle height sensor value maximum and minimum value input, etc. Target vehicle height map created from road driving conditions selected. a vehicle height selection means, and when the vehicle height output of the vehicle height sensor deviates from a predetermined target vehicle height range selected by the vehicle height selection means, opening and closing control of the valve means is performed to perform vehicle height adjustment control; The vehicle height adjustment control means interrupts the vehicle height adjustment control when a centrifugal force of a predetermined value or more is applied.

Therefore, vehicle height sensors such as the right front wheel height sensor FR1, the left rear wheel height sensor RL, the left front wheel height sensor FL, and the right rear wheel height sensor RR, which are arranged on the four wheels of the vehicle, are used to detect the ground and the vehicle body 80. The vehicle height between the two is detected as the height between the axle and the vehicle body BO. In addition, a low vehicle height selection switch (LOWS W) and an intermediate vehicle height selection switch (N0R)fAL are provided, which select a target vehicle height that defines a vehicle height range from a target vehicle height map created from road driving conditions, which constitutes a vehicle height selection means. The target vehicle height is selected by inputting a vehicle height selection switch consisting of SW, a high vehicle height selection switch HIGH3W, inputting vehicle speed data, and inputting maximum and minimum vehicle height sensor values.

When the vehicle height is not within the selected vehicle height range, the vehicle height adjustment control means adjusts the air suspension for the right front wheel EFR1, the left front wheel air suspension EFL, the right rear wheel air suspension ERR1, the left rear wheel air suspension, and the right rear wheel air suspension ERR1 for each wheel. E
Right front wheel solenoid valve VFR1, left front wheel solenoid valve VFL, right rear wheel solenoid valve VR, which controls the supply of fluid pressure from the compressor CP to the suspension such as RL, or controls the discharge of fluid pressure from the suspension.
R1 Valve means such as the left rear wheel solenoid valve VRL and the exhaust solenoid valve EX are opened to supply or discharge fluid pressure to control the vehicle height. At this time, if a centrifugal force exceeding a predetermined value is applied, the vehicle height adjustment control is interrupted.

Therefore, if centrifugal force exceeding a predetermined level is applied when traveling on a curve such as an interchange slope, the vehicle height adjustment control of the vehicle height adjustment control means will be interrupted. Since the vehicle height of the wheels of the vehicle does not rise when driving on a curve, the vehicle maintains a predetermined balanced vehicle height without losing driving stability even when driving on a straight line such as on an expressway after driving on a curve. can.

By the way, the vehicle height selection means for selecting a target vehicle height that defines a vehicle height region that brings the vehicle body into a predetermined vehicle height state in the above embodiment is as follows:
Although the selection was made from a target vehicle height map created from road driving conditions selected by inputting a vehicle height selection switch for selecting vehicle height, inputting vehicle speed data, and inputting maximum and minimum values of vehicle height sensor values, the present invention is implemented. In some cases, it may be calculated using a specific formula.

Alternatively, the vehicle height may be determined only by a vehicle height selection switch that selects the vehicle height. However, the control speed can be made faster by selecting from the target vehicle height map of this embodiment.

Further, the centrifugal force detection means for detecting the centrifugal force applied to the vehicle body in the above embodiment uses a value calculated from the vehicle speed and the rotation angle of the steering wheel, but when implementing the present invention, A known acceleration sensor that detects acceleration in a direction perpendicular to the traveling direction can be used. However, when calculating from the vehicle speed and the turning angle of the steering wheel as in the above embodiment, sensors such as those for power steering can be shared and the number of parts can be reduced.

In addition, the centrifugal force detection means for detecting the centrifugal force applied to the vehicle body in the above embodiment was calculated from the characteristic diagram of FIG. 9(a) or FIG. 9(b), or when implementing the present invention, ,
It can also be approximated by an inverse proportional curve or a proportional straight line with a negative slope.

When the vehicle height output of the vehicle height sensor of the above embodiment deviates from the predetermined target vehicle height range selected by the vehicle height selection means, the valve means is controlled to open and close to perform vehicle height adjustment control. When carrying out the present invention, the vehicle height adjustment control means for interrupting the vehicle height adjustment control when a centrifugal force of a predetermined value or more is applied is a known vehicle height adjustment control means that interrupts the vehicle height adjustment control when a centrifugal force of a predetermined value or more is applied. It is only necessary to perform control such that the vehicle height adjustment control can be interrupted only at certain times.

In the above embodiment, the fluid pressure is air pressure, and the right front wheel air suspension EFR and the left front wheel air suspension E
FL, right rear wheel air υ suspension ERR1, left rear air suspension ERL, etc. are used, but when implementing the present invention, the present invention is not limited to gas, and liquids such as oil may be used. Good too.

[Effects of the Invention] As described above, in the vehicle height adjustment device of the present invention, the vehicle height output of the vehicle height sensor that detects the height between the axle and the vehicle body adjusts the vehicle height to bring the vehicle body into a predetermined vehicle height state. Selecting a target vehicle height within a region When the vehicle deviates from the predetermined target vehicle height region selected by the vehicle height selection means, fluid pressure is supplied from the compressor to the suspension disposed on each wheel or fluid pressure from the suspension is controlled. Vehicle height adjustment control is performed by opening and closing a valve means for controlling discharge of fluid pressure, and at this time, if a centrifugal force of more than a predetermined value is applied to the vehicle body, the vehicle height adjustment control is interrupted.

Therefore, when traveling on a curve such as an interchange slope, if a centrifugal force exceeding a predetermined value is applied, the vehicle height adjustment control of the vehicle height adjustment control means can be interrupted. The vehicle height of the positioned wheels is not raised when traveling on a curve. Therefore, a predetermined balanced vehicle height can be maintained without losing running stability even when the vehicle immediately enters straight driving on an expressway or the like after driving on a curve.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a fluid control system and an electrical control system of a vehicle height adjustment device according to an embodiment of the present invention, and FIG. 2 is an explanatory diagram showing a schematic configuration of a vehicle height adjustment device according to an embodiment of the present invention. Figures 3 to 6
9 is a flowchart for controlling the main program of the control circuit of the vehicle height adjustment device according to an embodiment of the present invention, FIGS. 7 and 8 are flowcharts for the centrifugal force area calculation routine of the main program, and FIG. The centrifugal force detection characteristic diagram used in the embodiment shown in the figure, Figure 10 is an output state specification diagram of the vehicle height adjustment control of the embodiment shown in Figure 1, and Figure 11 is an explanation showing the state when the vehicle is running on a curve. It is a diagram. In the figure, BO: Vehicle body, ECU: Control circuit, SS: Vehicle speed sensor, CP: Compressor, FR: Right front wheel height sensor, RL: Left rear wheel height sensor, FL: Left front wheel height sensor, RR: Right rear wheel. Wheel height sensor, EFR: Right front wheel air suspension, EFL: Left front air suspension, ERR: Right rear air suspension, ERL: Left rear air suspension, VFR: Right front solenoid valve, VFL: Left front solenoid valve. , VRR: Right rear wheel solenoid valve, VRL: Left rear wheel solenoid valve, EX: Exhaust solenoid valve, IS: Rotation angle sensor. In addition, in the figures, the same reference numerals and the same symbols indicate the same or equivalent parts. Patent applicant Aisin Seiki Co., Ltd.

Claims (4)

[Claims] (1) A vehicle height sensor that detects the height between the axle and the vehicle body, a centrifugal force detection means that detects the centrifugal force applied to the vehicle body, and controls the supply of fluid pressure from the compressor to the suspension installed on each wheel. or a valve means for controlling discharge of fluid pressure from the suspension; a vehicle height selection means for selecting a target vehicle height that defines a vehicle height range for bringing the vehicle body into a predetermined vehicle height state; and a vehicle height sensor for selecting a vehicle height. When the output is out of the predetermined target vehicle height range selected by the vehicle height selection means, the valve means is controlled to open and close to perform vehicle height adjustment control, and when a centrifugal force of more than a predetermined value is applied, the A vehicle height adjustment device comprising: vehicle height adjustment control means for interrupting vehicle height adjustment control; (2) The centrifugal force detection means for detecting the centrifugal force that interrupts the vehicle height adjustment control is calculated from the vehicle speed and the rotation angle of the steering wheel.
Vehicle height adjustment device described in section. (3) The centrifugal force detection means for detecting the centrifugal force that interrupts the vehicle height adjustment control is an acceleration sensor that detects acceleration in a direction perpendicular to the traveling direction of the vehicle. The vehicle height adjustment device according to item 1. (4) The vehicle height selection means for selecting a target vehicle height that defines a vehicle height range that brings the vehicle body into a predetermined vehicle height state includes a vehicle height selection switch input for selecting the vehicle height, a vehicle speed data input, and a vehicle height sensor. 2. The vehicle height adjustment device according to claim 1, wherein the vehicle height adjustment device is selected from a target vehicle height map created from road driving conditions selected by inputting maximum and minimum values.