JPH0780412B2 - Vehicle height control device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an improvement in a vehicle height control device, and more particularly, to a vehicle height adjustment such as a roll height, a dive height or a squat height of a vehicle. The present invention relates to a vehicle height control device that temporarily removes the influence of fluctuations, realizes appropriate vehicle height adjustment sensitivity in accordance with the running state and getting-on / off state of a vehicle, and minimizes the vehicle height adjustment frequency.

[Conventional technology]

The applicant previously provided a vehicle height control device in Japanese Patent Application No. 60-105438.

In this prior art, when the vehicle height sensor detects that the vehicle height is higher than the proper range, the vehicle height is adjusted to decrease, and when the vehicle height is detected to be lower than the proper range, the vehicle height is increased. Adjustments are made to control the vehicle height so that it is always in the proper range.

In this case, the vehicle height difference value adding means obtains a difference value between the vehicle height value detected by the vehicle height detecting means and a preset vehicle height appropriate area value, adds the difference value, and compares the vehicle height added values. The addition value is compared with a predetermined reference value by means, and the vehicle height adjustment means starts the vehicle height adjustment so that the vehicle height value falls within the vehicle height proper range according to the result of the comparison. Has been done.

And by doing this, make the start time of vehicle height adjustment accurate,
The effect of temporary fluctuations of the vehicle such as rolling, dive or squat of the vehicle is eliminated.

[Problems to be solved by the invention]

However, in such a prior art vehicle height control device, the predetermined reference value is constant, and the addition value calculated by the vehicle height difference value adding means is compared with the constant predetermined reference value for judgment. Because of the configuration, the vehicle height adjustment operation does not start immediately immediately after the occupant gets in and out of the vehicle, or the vehicle height adjustment frequency becomes unnecessarily high when the vehicle runs on a running road with continuous slopes, for example. There was a problem.

The present invention has been made by paying attention to the problems of the prior art as described above, and makes it possible to accurately determine the starting point of vehicle height adjustment and to prevent the influence of temporary vehicle height changes such as vehicle roll, dive or squat. It is an object of the present invention to provide a vehicle height adjusting device that is not only removed but also realizes appropriate vehicle height adjustment sensitivity and minimizes vehicle height adjustment frequency.

[Means for solving problems]

Therefore, as shown in FIG. 1, a vehicle height adjusting device of the present invention includes a suspension device which is interposed between a vehicle body and wheels and which includes a fluid chamber capable of adjusting the vehicle height by supplying and discharging fluid. A fluid supply source capable of supplying a fluid to the fluid chamber and a vehicle height detection means for detecting a vehicle height value, and an actual vehicle height value detected by the vehicle height detection means is supplied to the fluid chamber from the fluid supply source. In a vehicle height control device that adjusts the actual vehicle height value of the wheel portion so as to supply the fluid or discharge the fluid from the fluid chamber so as to be contained in the target vehicle height region or to match the target vehicle height value. A vehicle height difference value adding means for obtaining a difference value between the actual vehicle height value detected by the vehicle height detection means and a preset vehicle height appropriate value or vehicle height appropriate area value, and adding the difference value; The added value calculated by the vehicle height difference adding means is a predetermined reference So as to match the vehicle height value with the vehicle height appropriate value by supplying / discharging the fluid to / from the fluid chamber in accordance with the vehicle height addition value comparing means for comparing with the vehicle height addition value comparing means, or Vehicle height adjusting means for starting vehicle height adjustment so that the vehicle height value falls within the appropriate vehicle height area value; and running / boarding / alighting status detecting means for detecting at least one of the running status and the boarding / alighting status of the vehicle. , The running
It is characterized by further comprising predetermined reference value changing means for changing the determination reference value according to at least one of the running situation and the getting on / off situation detected by the getting on / off situation detecting means.

[Action]

The vehicle height value is detected by the vehicle height detection means, the difference value between the vehicle height value detected by the vehicle height difference value adding means and a preset vehicle height appropriate value or vehicle height appropriate area value is obtained, and the difference value is obtained. Is added. On the other hand, at least one of the running situation and the getting on / off situation of the vehicle is detected by the running / getting on / off situation detecting means, and at least one of the detected running situation and getting on / off situation is detected by the predetermined reference value changing means. Depending on,
Change the predetermined reference value. The vehicle height value is calculated by comparing the added value calculated by the vehicle height added value comparison means with the changed predetermined reference value, and supplying and discharging the fluid to and from the fluid chamber according to the comparison result by the vehicle height adjustment means. The vehicle height adjustment is started so as to match the vehicle height appropriate value or to keep the vehicle height value within the vehicle height appropriate area.

〔Example〕

 An embodiment of the present invention will be described below with reference to the drawings.

Although normal air is used as the working medium for vehicle height control in this embodiment, the working medium is not limited to this.
Appropriate fluids such as gas other than air or oil or other liquid can be used.

The configuration will be described with reference to FIG.

First, the air system will be described. 1 is a suspension device interposed between the vehicle body and, for example, the left and right rear wheels, and the suspension device 1 includes an air chamber 2 as a fluid chamber and a shock absorber 3. The air chamber 2 is formed by an elastic body 4 made of, for example, rubber or the like that surrounds the space between the vehicle body and the shock absorber 3 in a vertically expandable and contractible manner.

5 is a reservoir tank for supplying air to the air chamber 2, 6 is a compressor for supplying air to the air chamber 2 or the reservoir tank 5, and these reservoir tank 5 and compressor 6 are air supply sources as fluid supply sources. . Reference numeral 7 is a dryer for dehumidifying the air discharged from the compressor 6, and 8 is a check valve for preventing backflow of the reservoir tank pressure.

Reference numeral 9 is an air supply valve provided between the reservoir tank 5 and the air chamber 2, 10 is a supply / discharge valve provided at the inlet side of the air chamber 2, and 11 is an exhaust valve provided at the outlet side of the compressor 6. Yes, each valve 9, 10, 11 has an electromagnetic solenoid 12, 13, 14 for opening and closing the valve.

Next, explaining the electric system, 16 is a vehicle height sensor for detecting the vehicle height of the rear wheels, and this vehicle height sensor 16 uses ultrasonic waves, potentiometer type or detection coil and inductance change. An appropriate format such as the one used can be used.

Reference numeral 17 denotes a vehicle speed sensor. The vehicle speed sensor 17 is, for example, one that magnetically or optically detects the rotation speed of an output shaft of a transmission (not shown) or a propeller shaft (not shown). 2 per revolution of the output shaft of
It outputs individual vehicle speed pulse signals.

18 is a door opening / closing switch, and this door opening / closing switch 18
Outputs a signal that is on when any one of the doors is open and off when all of the doors are closed.

Reference numeral 19 denotes a trunk opening / closing switch. The trunk opening / closing switch 19 outputs a signal which is turned on when the trunk is opened and turned off when the trunk is closed.

20 is an ignition key switch.

Further, reference numeral 21 is a manual vehicle height select switch. This manual vehicle height select switch 21 is, for example, an auto mode for automatically controlling the vehicle height and a low vehicle height for improving stability at high speeds. Two modes can be selected, a low mode that is fixed at a high value.

Reference numeral 22 is a pressure switch for detecting the internal pressure of the reservoir tank 5. The pressure switch 22 is, for example,
When the internal pressure of is higher than the set value, it is turned on, and when it is lower than the set value, it is turned off.

Reference numeral 23 is a battery, 24 is a relay, and 25 is a motor for driving the compressor 6.

Reference numeral 26 denotes a controller. The controller 26 includes a microcomputer 27, drive circuits 28, 29, 30 for driving the electromagnetic solenoids 12, 13, 14 and a drive circuit for driving the relay 19.
It is configured to include 31 and.

The microcomputer 27 is configured to include at least an interface circuit 32, an arithmetic processing unit 33, and a storage device 34 such as RAM or ROM. The interface circuit 32 has a vehicle height sensor 16, a vehicle speed sensor 17, a door opening / closing on its input side. Switch 18, trunk open / close switch 19, ignition key switch 20,
Manual vehicle height select switch 21 and pressure switch 21
Is connected to the drive circuit 28, 29, 3
0 and 31 are connected.

The arithmetic processing unit 33 receives the detection signals of the vehicle height sensor 16 and the vehicle speed sensor 17 via the interface circuit 32, and the door opening / closing switch 18, the trunk opening / closing switch 19, the ignition key switch 20, the manual vehicle height select switch 21, and the pressure switch 22. Each output signal of is read, and the calculation and other processes described later are performed based on these read signals. In addition, the storage device 34
Stores a predetermined program necessary for executing those processes, a vehicle height proper value or a vehicle height proper area, and a predetermined reference value, and sequentially stores the processing result of the arithmetic processing unit 33 and the like.

Next, the above embodiment and operation will be described.

Detection signal according to vehicle height by vehicle height sensor 16, vehicle speed sensor
The vehicle speed pulse signal from 17, the output signals from the door opening / closing switch 18, the trunk opening / closing switch 19, the ignition key switch 20, the manual vehicle height select switch 21, and the pressure switch 22 are supplied to the interface circuit of the microcomputer 22.

FIG. 3 shows a procedure of processing executed by the microcomputer 27.

In the figure, reads the vehicle height h from the detection signal of the vehicle height sensor 16 at step, then in step ~, obtaining the difference value of the vehicle height value h and the vehicle height proper domain values h _L to h _U.

It is assumed that the vehicle height appropriate area is an area between the upper limit value h _U and the lower limit value h _L. First, in a step, the vehicle height value h and the upper limit value h _{U are set.}
And h> h _U , the process proceeds to step to obtain the difference value Δh = h−h _U. If h ≦ h _U in the step, the process proceeds to the step and the vehicle height value h is compared with the lower limit value h _L. If h <h _L , the process proceeds to the step and the difference value Δh = h−h _L Ask for. Then, if h ≧ h _L in the step, the process proceeds to the step and Δh = 0. Therefore, the difference value Δh is + if the vehicle height value h is higher than the handmade area,
If it is low, it takes a negative value.

Next, at step, the difference value Δh obtained at step ,, is added to the register H to obtain the added value H.

Next, at step, a predetermined reference value changing subprogram for changing the predetermined reference value H ₀ for comparing and judging the added value H is executed.

This predetermined reference value changing subprogram is shown in FIG. 4, and in this case, the predetermined reference value H ₀ is extremely small, small,
The medium and large four values are stored in the ROM of the storage device 34 in advance, and one of the four values is selected in accordance with the running condition and the getting on / off condition of the vehicle as described below. And is temporarily stored in a predetermined register H ₀ .

That is, in FIG. 4, first in the step,
The vehicle speed value is obtained based on the vehicle speed pulse signal from the vehicle speed sensor 17, and it is determined from the vehicle speed value whether the vehicle is stopped (that is, running).

When the vehicle is stopped, the process proceeds to the next step, and the output signal of the trunk opening / closing switch 19 indicates whether or not it is immediately after the door is changed from the open state to the closed state based on the output signal of the door opening / closing switch 18. Based on whether or not it is immediately after the trunk changes from the open state to the closed state, based on the output signal of the ignition key switch 20, or immediately after the ignition key switch is turned on, the manual height selection switch 21 It is determined whether or not it is immediately after the manual height selection operation is performed based on the output signal of
If the door has changed from open to closed, or if the trunk has changed from open to closed,
If either one of the case where it is immediately after the ignition key switch 20 is turned on and the case where it is immediately after the manual vehicle height select operation is performed, it moves to the next step and the predetermined reference reads the minimum value stored as values of H0 in the ROM of the storage device 34, and temporarily stored in the register H _0, the process returns to the program that is shown in Figure 3.

In the step, it is not immediately after the door changes from the open state to the closed state, immediately after the trunk changes from the open state to the closed state, immediately after the ignition key switch 20 is turned on, and the manual vehicle height select operation is performed. If it is not immediately after, the process proceeds to the next step to determine whether the door is open from the output signal of the door opening / closing switch 18 and whether the trunk is open from the output signal of the trunk opening / closing switch 19. If it is determined whether or not there is at least one of the case where the door is open and the case where the trunk is open, the process proceeds to the next step and the predetermined reference value H ₀ is set to a small value. Read the value,
Temporarily store in register H ₀ and return to the original program.

If both the door and the trunk are in the closed state in the step, the process proceeds to the next step, and it is determined from the output signal of the ignition key switch 20 whether or not the ignition key switch is in the off state, and the ignition key is turned off. If the switch is in the on state, then the process proceeds to step reads the middle value as a predetermined reference value H _0, and temporarily stored in the register H _0, the process returns to the original program.

If the ignition key is in the off state in step, the process proceeds to step, the large value is read as the predetermined reference value H ₀ , the value is temporarily stored in the register H ₀ , and the process returns to the original program.

Further, in step, when it is determined that the vehicle is traveling, the process proceeds to the next step, in which the vehicle height appropriate area value as the target vehicle height area value is determined from the output signal of the manual vehicle height select switch 21. Whether or not it is immediately after the change, or when the selected position of the manual vehicle height select switch 21 is in the auto mode, for example, in accordance with a change in the vehicle speed value, the vehicle height appropriateness as the target vehicle height region value is similarly set. It is determined whether or not it is immediately after the area value has changed. Then, when it is determined that the vehicle height appropriate region value has just changed, the process proceeds to the next step, the minimum value is read as the predetermined reference value H ₀ , and is temporarily stored in the register H ₀ . Return to the program.

If it is determined in step that it is not immediately after the vehicle height appropriate region value is changed, the process proceeds to step, and a large value is read as the predetermined reference value H ₀ , and the register H ₀ is read.
Temporarily store in and return to the original program.

Returning to FIG. 3, after the predetermined reference value H ₀ is temporarily stored in the register H ₀ in the predetermined reference value changing subprogram of the step as described above, the process proceeds to the next step, and the register is changed in the step. Addition value H stored in H
Is compared with the predetermined reference value H ₀ stored in the register H ₀ by the above-mentioned predetermined reference value changing subprogram, and H ≧
If it is H ₀ , the process proceeds to step and the adjustment for lowering the vehicle height is started.

The adjustment for lowering the vehicle height is performed by supplying a control signal of "L (low level or logical value" 0 ")" from the interface circuit 32 to the drive circuit 28 to make the electromagnetic solenoid 12 non-excited state. Is closed, the control signal of "H (high level or logical value" 1 ")" is supplied from the interface circuit 32 to the drive circuit 29, the electromagnetic solenoid 13 is excited, and the supply / discharge valve 10 is opened. This is done by supplying the control signal "H" from the circuit 32 to the drive circuit 30, setting the electromagnetic solenoid 14 in the excited state, and opening the exhaust valve 11.
By doing this, the air supply / exhaust valve 10 and the exhaust
Air is exhausted to the outside by decreasing 11 and the vehicle height decreases.

Tsuidei, the vehicle height becomes proper in step (ie vehicle height value h is in the vehicle height appropriate area value h _L to h _U) whether the examined steps of vehicle height lowering operation if the vehicle height is still high When the vehicle height becomes appropriate, the process proceeds to step to finish the vehicle height adjustment and set the non-adjustment state.

When the vehicle height is not adjusted, the control signals “L”, “L”, and “L” are supplied from the interface circuit 32 to the drive circuits 28, 29, 30 to deactivate the electromagnetic solenoids 12, 13, 14 respectively. Then, the air supply valve 9, the air supply / exhaust valve 10, and the exhaust valve 11 are all closed.

Next, the process proceeds to step, the content of the register H storing the added value H at step is reset, and the process proceeds to step.

Alternatively, this reset may be performed when the vehicle height non-adjustment state continues for a predetermined time.

In the step, if H <H ₀ , the process moves to the step and it is checked whether or not H ≦ −H ₀ . If YES, go to step and make an adjustment to raise the vehicle height.

The adjustment to raise the vehicle height is basically done with the pressure switch 22.
The signal is used to check whether or not the internal pressure of the reservoir tank 5 is high. If the internal pressure is high, the pressure is accumulated in the reservoir tank 5, and if the internal pressure is low, the compressor 6 is driven.

When the vehicle height is increased by accumulating the pressure in the reservoir tank 5, the interface circuit 32 supplies the control signals "H", "H", and "L" to the drive circuits 28, 29, 30 and the electromagnetic solenoid.
12,13,14 are energized, energized, de-energized, and air supply valve 9,
The supply / exhaust valve 10 and the exhaust valve 11 are opened, closed, and closed. As a result, air is supplied from the reservoir tank 5 to the air chamber 2, and the vehicle height rises.

When the vehicle height is increased by driving the compressor 6, the interface circuits 32 supply control signals "L", "H", "L" to the drive circuits 28, 29, 30 to cause electromagnetic solenoids 12, 13, 14 is de-energized, energized, de-energized, air supply valve 9, air supply / exhaust valve 10, exhaust valve 11 are closed, opened, and closed, and control signal "H" is supplied from interface circuit 32 to drive circuit 31. Then, the relay 24 is turned on and the motor 25 is driven.

Next, check whether the vehicle height has become appropriate at the step. If the vehicle height is still low, continue adjusting the vehicle height increase at the step. If the vehicle height becomes appropriate, move to step and adjust the vehicle height unadjusted. Then, the process goes to the step, the added value H is reset, and the process goes to the step.

In the step, if H> −H _0, that is, −
If H ₀ <H <H ₀ , it is judged that it is not enough to start the vehicle height, and the process proceeds to step to make the vehicle height non-adjustment, and the process proceeds to step.

The operation of vehicle height non-adjustment in step is the same as the operation in step described above.

In the step, it is checked whether or not the control is ended, and if it is not ended, the process returns to the step and the above-described operation is repeated.

FIG. 5 shows a specific example of the vehicle height control according to the present invention, and FIG. 5 (a) shows a case where the vehicle height continues to be extremely high.
FIG. 5 (b) shows a case where the vehicle height continues to be slightly high, and as is clear from both figures, if the vehicle height is extremely high, the vehicle height adjustment will start earlier and the vehicle height will not be so high. For example, the start of vehicle height adjustment will be delayed. Therefore, the start time of the vehicle height adjustment is accurately determined according to the degree of deviation of the vehicle height value.

Further, as shown in FIG. 5 (c), when the vehicle height continues to be high and the vehicle height value temporarily enters the proper region due to the rolling of the vehicle in the period t1, the added value H is During that period t1, a fixed value continues without being added, and during period t2
In the case where the vehicle height temporarily enters the proper range and the vehicle height becomes low due to the dive of the vehicle, the additional value H is slightly reduced. However, in either case, it does not affect the decision to start adjusting the vehicle height.

FIG. 6 shows a concrete example of the vehicle height control by the conventional device before the above prior art, but does not consider the extent to which the vehicle height value deviates from the proper range value, and the predetermined time T ₀ after the vehicle height deviates from the proper range. After that, the vehicle height adjustment operation was started.

Therefore, when the vehicle height shown in FIG. 6 (a) continues to be extremely high or when the vehicle height shown in FIG. 6 (b) continues to be slightly high, the time when the vehicle height deviates from the proper range. The adjustment to lower the vehicle height is started after a certain period of time has passed, and no consideration was given to the degree of deviation from the appropriate vehicle height range.

Further, as shown in FIG. 6 (c), the timer starts the measurement of a predetermined time from the time when the vehicle height value deviates from the proper region to the high region, and the vehicle rolls in the period t1 before the predetermined time elapses. When the high price temporarily enters the proper range,
The adjustment to lower the vehicle height is not started because the timer is reset, and similarly, before the elapse of the predetermined time, the period t2
Even if the vehicle height value temporarily enters a proper range or a low state due to the vehicle dive, the adjustment of lowering the vehicle height is not started because the timer is reset. Or the vehicle height adjustment timing was inappropriate due to squats.

In the embodiments described above, the case where normal air is used as the fluid has been illustrated, but as described above, the present invention is not limited to this, and a suitable fluid such as a gas other than air or oil or other liquid. Can be used.

Further, although the suspension device including the air chamber is attached to the rear left and right wheel regions as an example, the suspension device is not limited to this and is attached to the front left and right wheel regions, or is attached to the front, rear, left and right four wheel regions. Appropriate ones such as ones are used.

Further, although a combination of a reservoir tank and a compressor is shown as an air supply source that is a fluid supply source, only the compressor may be used.

Further, although the vehicle height control in which the vehicle height is set within the vehicle height appropriate area is exemplified, the vehicle height control may be performed so that the vehicle height matches the vehicle height appropriate value.

Further, in FIGS. 1 to 4, steps 1 to 4 are concrete examples of the vehicle height difference value adding means, which are a vehicle speed sensor 17, a door opening / closing switch 18, a trunk opening / closing switch 19, an ignition key switch 20, and a manual vehicle height selection switch 21. Is a specific example of the running / getting on / off status detecting means,
,,,, are specific examples of the predetermined reference value changing means,
Step, is a concrete example of the vehicle height added value comparison means, and includes an air supply valve 9 having electromagnetic solenoids 12, 13, 14 and a supply / discharge valve 1.
0, steps of exhaust valve 11 and drive circuits 28, 29, 30
,, and are specific examples of vehicle height adjusting means.

Further, although the one using the microcomputer as the controller is shown, instead of this, it is also possible to configure the controller by combining electronic circuits such as a subtraction circuit, an addition circuit, a comparison circuit, a logic circuit, and a command value setting circuit. Is.

〔The invention's effect〕

As described above, according to the vehicle height control device of the present invention, the difference value between the vehicle height value detected by the vehicle height detection means and the vehicle height appropriate value or the vehicle height appropriate area value is obtained, and the difference value is added. Then, the added value is compared with a predetermined reference value, and vehicle height adjustment is started so that the vehicle height value matches the vehicle height appropriate value or the vehicle height value falls within the vehicle height appropriate area value according to the comparison result. In addition to the configuration described above, the running / boarding situation detection means for detecting at least one of the running status and the boarding / alighting status of the vehicle, and the long running and boarding status detected by the running / boarding situation detection means According to at least one situation, the predetermined reference value changing means for changing the predetermined reference value is provided, so that the vehicle height adjustment start time is appropriately determined according to the extent to which the vehicle height value deviates from the vehicle height appropriate range value. And in addition, the roll of the vehicle, Eliminates the effects of temporary vehicle height fluctuations such as Eve or Squat, realizes appropriate vehicle height adjustment sensitivity, minimizes vehicle height adjustment frequency, and provides vehicle height control that matches the feeling. Therefore, it is possible to provide the same, it is advantageous in terms of durability, and it is possible to obtain the effect of cost reduction.

[Brief description of drawings]

FIG. 1 is a block diagram showing a basic configuration of a vehicle height control device of the invention, FIG. 2 is a configuration diagram showing an embodiment of the invention, and FIG.
FIG. 4 is a flow chart showing a processing procedure executed by a microcomputer, FIG. 4 is a flow chart showing a processing procedure of a predetermined reference value changing subprogram which is also executed by a microcomputer, and FIG. 5 is a vehicle height control by the apparatus of the present invention. A time chart showing a concrete example of
FIG. 6 is a time chart showing a concrete example of vehicle height control by a conventional device before the conventional device. 1 ... Suspension device, 2 ... Air chamber, 5 ... Reservoir tank, 6 ... Compressor, 9 ... Air supply valve,
10 …… supply / exhaust valve, 11 …… exhaust valve, 16 …… vehicle height sensor, 17 …… vehicle speed sensor, 18 …… door opening / closing switch, 19…
… Trunk opening / closing switch, 20 …… Ignition key switch, 21 …… Manual height switch, 22…
… Pressure switch, 25 …… Motor, 26 …… Controller,
27 …… microcomputer, 28,29,30,31 …… driving circuit, 32 …… interface circuit, 33 …… arithmetic processing unit,
34 ... Storage device.

Claims (1)

[Claims] 1. A suspension device, which is interposed between a vehicle body and a wheel, including a fluid chamber capable of adjusting a vehicle height by supplying and discharging a fluid, and a fluid supply source capable of supplying the fluid to the fluid chamber. A vehicle height detection means for detecting a vehicle height value, and the actual vehicle height value detected by the vehicle height detection means is supplied to the fluid chamber from the fluid supply source or discharged from the fluid chamber. In the vehicle height control device that adjusts the actual vehicle height value of the wheel portion so as to be within the target vehicle height area or to match the target vehicle height value, the actual vehicle height value detected by the vehicle height detection means and A vehicle height difference value adding means for obtaining a difference value from the set vehicle height appropriate value or the vehicle height appropriate area value and adding the difference value, and an addition value calculated by the vehicle height difference value adding means are predetermined. Vehicle height addition value comparing means for comparing with a reference value, and the vehicle height addition By supplying / discharging the fluid to / from the fluid chamber according to the comparison result by the value comparison means, the vehicle height value is made to coincide with the vehicle height appropriate value or the vehicle height value is kept within the vehicle height appropriate area value. A vehicle height adjusting means for starting height adjustment, a traveling / boarding situation detecting means for detecting at least one of a traveling situation and a boarding / alighting situation of the vehicle, and a traveling situation detected by the traveling / boarding / alighting situation detecting means, A vehicle height control device comprising: predetermined reference value changing means for changing the determination reference value according to at least one of the getting on and off situations.