JPH10914A - Car height adjusting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the easiness in getting on or off a car by increasing a car descending speed of a car height adjusting device. SOLUTION: A car height adjusting device is provided with fluid pressure actuators 11i, 11FL, 11FR, 11RL, 11RR, which are interposed between wheels Wi, WFL, WFR, WRL, WRR and a car body so that, when oil is supplied to the actuator, the car height corresponding to the position of the actuator supplied with the oil is increased/decreased, an oil pump 20, which supplies the fluid pressure actuator with the oil accommodated in a reserve tank 16, a drain pipe 40, which discharges the oil from the fluid pressure actuator to the reserve tank 16, and a discharge valve 41, which controls the communication of the drain pipe 40. When the car height is to be decreased, the discharge valve 41 is turned into an open state, while the driving of the pump 20 is stopped, so that the oil is discharged to the reserve tank 16 via the pump 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle height adjusting device for adjusting the vehicle height by supplying and discharging working fluid to and from a hydraulic actuator interposed between a vehicle body and wheels.

[0002]

2. Description of the Related Art Conventionally, there has been a vehicle height adjusting device for adjusting a vehicle height by supplying and discharging a working fluid to and from a fluid pressure actuator. This vehicle height adjusting device is, for example, a vehicle having a speed of 80 km / h.
When the vehicle travels at a high speed, the vehicle height is lower than at normal speed to improve running stability, or the vehicle height is kept constant regardless of changes in the number of passengers or the weight of the load. When the occupant gets on and off, the height of the occupant is made lower than the height of the occupant during traveling to improve the easiness of getting on and off. Also, by providing switches that can arbitrarily switch the vehicle height between high level and low level, and by setting the vehicle height specified by these switches,
In some cases, the vehicle height is lowered or raised according to the occupant's preference. In these cases, the current vehicle height (hereinafter,
Currently called the vehicle height. ) Is controlled to coincide with the target vehicle height.

That is, when the current vehicle height is lower than the target vehicle height, the oil in the reserve tank is supplied by a pump to an actuator interposed between the wheels and the vehicle body so that the vehicle height reaches the target vehicle height. To raise. On the other hand, when the current vehicle height is higher than the target vehicle height, oil is discharged from the actuator to lower the vehicle height to the target vehicle height.

[0004] As this type of vehicle height adjusting device, there is a device disclosed in Japanese Patent Application Laid-Open No. 4-108017.

[0005]

By the way, the oil discharged from the actuator is returned to the reserve tank. However, since there is only a path for returning the oil through the discharge valve, the oil return speed is reduced. However, the vehicle is limited by the diameter of the discharge valve, and a sufficiently low descent speed cannot be obtained.

[0006] In particular, when the occupant gets on and off the vehicle, it is required to lower the vehicle height quickly in order to improve the getting on and off.
Since it takes time to descend the vehicle height, sufficient getting on and off properties cannot be obtained, and further improvement in getting on and off properties has been required.

An object of the present invention is to increase a vehicle descent speed,
An object of the present invention is to provide a vehicle height adjusting device capable of improving the getting on and off.

[0008]

According to a first aspect of the present invention, there is provided a vehicle height adjusting device which is interposed between a wheel and a vehicle body, and which supplies and discharges a working fluid to increase or decrease the vehicle height of a corresponding portion. A pressure actuator, a fluid pressure source for supplying a working fluid stored in a reserve tank to the fluid pressure actuator, a discharge passage for discharging the working fluid from the fluid pressure actuator to the reserve tank, and a communication between the discharge passage. In a vehicle height adjusting device provided with a discharge valve for controlling the vehicle, when the vehicle height drops, the discharge valve is opened and the drive of the fluid pressure source is stopped, and the operation to the reserve tank is performed via the fluid pressure source. The fluid is discharged.

Therefore, according to the vehicle height adjusting device of the present invention, when the vehicle height drops, the working fluid discharged from the actuator returns to the reserve tank not only through the discharge valve but also through the fluid pressure source. Therefore, the vehicle descent speed can be increased.

A vehicle height adjusting device according to a second aspect of the present invention is provided with a fluid pressure actuator interposed between a wheel and a vehicle body to increase or decrease the vehicle height of a corresponding portion by supplying and discharging a working fluid, A fluid pressure source for supplying a working fluid stored in a reserve tank to the fluid pressure actuator, a discharge passage for discharging the working fluid from the fluid pressure actuator to the reserve tank, and a discharge valve for communicating with the discharge passage. Equipped with a vehicle height adjustment device,
While the discharge valve is in an open state, the fluid pressure source is driven in a direction opposite to a direction in which a working fluid is supplied to an actuator,
The working fluid is discharged to the reserve tank via the fluid pressure source.

Therefore, according to the vehicle height adjusting device of the second aspect, when the vehicle height is lowered, the working fluid discharged from the actuator returns to the reserve tank via the fluid pressure source as well as the discharge valve. In this case, since the fluid pressure source is driven in the opposite direction to the supply of the working fluid to the actuator, a large amount of the working fluid can be discharged at a high speed via the fluid pressure source, and the vehicle height drop can be further reduced. Speed can be increased.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A vehicle height adjusting apparatus according to a first embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a schematic configuration diagram schematically showing a fluid circuit of the vehicle height adjusting device 10. As shown in FIG. 1, the vehicle height adjustment device 10 is configured as follows as a hydraulic vehicle height adjustment device using a hydraulic actuator.

The vehicle height adjusting device 10 includes actuators 11i ( _11FL , _11FR , _11RL , _11RL , 11FL) corresponding to the left front wheel _WFL , the right front wheel _WFR , the left rear wheel _WRL, and the right rear wheel _WRR , respectively.
11 _RR ). In the following description, the suffix i is arbitrarily representative of FL, FR, RL and RR assigned to each wheel.

The actuator 11i is a type of cylinder piston device, and is interposed between a suspension member 12i supporting a corresponding wheel and the vehicle body to suspend the vehicle body. The actuator 11i moves a piston up and down by supplying and discharging a working fluid (in this embodiment, oil) to and from the working fluid chamber, and changes the vehicle height at the corresponding wheel up and down.

An accumulator 13i and a variable throttle 14 are provided upstream of the line of the actuator 11i.
A variable damping force mechanism 15i is provided, and the actuator 11i can change the damping force with respect to the vertical movement of the vehicle body.

The vehicle height adjusting device 10 includes a reserve tank 16 for storing oil supplied to and discharged from the actuator 11i. This reserve tank 16
A suction pipe 21 for supplying the oil in the reserve tank 16 to the pump 20 is provided between the pump 20 and the pump 20. Note that a motor 22 for driving the pump 20 is arranged near the pump 20.

The pump 20 and the actuator 1
A main supply pipe 23 and a front-wheel supply pipe 24 branched downstream of the main supply pipe 23 are provided between 1 _FL and 11 _FR . On the other hand, the pump 20 and the actuator 1
A main supply pipe 23 and a rear-wheel supply pipe 25 branched downstream of the main supply pipe 23 are provided between 1 _RL and 11 _RR .

The front-wheel supply pipe 24 has a front-wheel leveling valve 26 for adjusting the vehicle height of the left and right front wheels, and a front wheel for switching the pair of actuators 11 _FL and 11 _FR between communicating and non-communicating. And the use gate valve 27 are arranged in series in this order. A rear-wheel supply pipe 25 is provided with a rear-wheel leveling valve 28 for adjusting the vehicle height of the right and left rear wheels, and a pair of actuators 11.
_A rear wheel gate valve 29 for switching between _RL and 11 _RR between communication and non-communication is arranged in series in this order. The front-wheel gate valve 27 and the rear-wheel gate valve 29 have an excessive road surface input by switching the pair of actuators 11 _FL and 11 _FR or 11 _RL and 11 _RR between communicating and non-communicating. It suppresses a rise in pressure when the vehicle is hit and a roll angle when the vehicle turns.

Here, the front wheel leveling valve 26, the rear wheel leveling valve 28, and the front wheel gate valve 2
7. The rear-wheel gate valve 29 is provided with two-way communication positions 26a to 29a for bidirectional communication between the front-wheel supply pipe 24 and the rear-wheel supply pipe 25, and the passage of oil from the pump 20 side. This is a two-position switching valve that selectively takes one of the one-way communication positions 26b to 29b that allows the passage of oil from the actuator 11i side at a predetermined pressure or higher.

The front-wheel leveling valve 26 and the rear-wheel leveling valve 28 normally take one-way communication positions 26b and 28b as shown in the figure. When adjusting the vehicle height (during ascent / descent), the two-way communication positions 26a and 26b are used. 28a. The front-wheel gate valve 27 and the rear-wheel gate valve 29 normally take the illustrated two-way communication positions 27a, 29a, and are switched to the one-way communication positions 27b, 29b when the vehicle turns.

The front-wheel leveling valve 26 and the rear-wheel leveling valve 28 are connected to the one-way communication position 26.
b, 28b, oil does not flow from the actuator 11i side at the normal internal pressure of the actuator 11i, and the pressure exceeding the normal internal pressure is
It is configured such that oil flows from the actuator 11i only when it is applied to the actuator 1i. Therefore, by switching the front-wheel leveling valve 26 and the rear-wheel leveling valve 28 to the one-way communication positions 26b, 28b, the vehicle height at that time can be maintained.

The supply pipe 24 for the front wheels is downstream of the branch point 24a of the front gate valve 27, a left front-wheel conduit 30 leading to the actuator 11 _FL of the left front wheel W _FL, the actuator 11 _FR of the right front wheel W _FR It is branched into a right front wheel conduit 31 that extends. Similarly, the rear wheel supply pipe 25 is branched into a left rear wheel pipe 32 and a right rear wheel pipe 33 at a branch point 25a.

Therefore, the oil which is pumped by the pump 20 and reaches the front wheel supply pipe 24 and the rear wheel supply pipe 25 through the main supply pipe 23 is fed to the front wheel leveling valve 26,
The rear wheel leveling valve 28 is moved from the illustrated one-way communication positions 26b, 28b to the two-way communication position 26b.
a, 28a, the front wheel leveling valve 26, the rear wheel leveling valve 28, and the downstream front gate valve 27 and rear wheel gate valve 2
Pass 9 Thereafter, the respective branch points 24a, 25
The vehicle is supplied to the actuators 11i of the respective wheels via vehicle height increasing reverse valves 35 to 38 downstream of the position a. Therefore, the vehicle height of the wheel corresponding to the actuator 11i to which the oil is supplied increases. Since the above-described switching between the front-wheel leveling valve 26 and the rear-wheel leveling valve 28 can be performed individually, it is necessary to raise the vehicle height only for the left and right front wheels, only for the left and right rear wheels, or for all the wheels of the vehicle. Can be.

On the other hand, the vehicle height adjusting device 10 is provided with a drain pipe 40 branched from the main supply pipe 23 and reaching the reserve tank 16 as a structure for discharging oil from the actuator 11i to lower the vehicle height. I have. This drain pipe 40 is opened and closed by a discharge valve 41. The discharge valve 41 has a one-way communication position 41a that allows the passage of oil from the main supply pipe 23 to the drain pipe 40, and a closed position that blocks the passage of oil from the main supply pipe 23 to the drain pipe 40. 41b is a two-position switching valve selectively adopting the valve 41b. This discharge valve 41
Is the closing position 4 that closes the pipeline when the vehicle height rises.
Take 1b and close the drain tube 40. On the other hand, at the time of vehicle height descent, the drain pipe 40 is opened by taking the one-way communication position 41a.

The vehicle height adjusting device 10 has a structure for lowering the vehicle height.
Each has a bypass pipe. That is, the vehicle height adjusting device 10
Is the left front wheel conduit 3 for the actuator 11 _FL.
0 from the branch point 30a, and the front-wheel gate valve 27
And the left front wheel bypass pipe 42 reaching the branch point 24b upstream of the front wheel gate valve 27, and the oil is supplied only to the front wheel supply pipe 24 side from the left front wheel pipe 30 in the pipe. It has a check valve 43 for vehicle height descent that allows passage.

Further, regarding the actuator 11 _FR ,
The right front wheel bypass pipe 44 branches off from the branch point 31a and bypasses the front wheel gate valve 27 and reaches a branch point 24b upstream of the front wheel gate valve 27. The vehicle height lowering check valve 45 that allows the passage of oil only on the side of the vehicle. Similarly, for the actuator 11 _RL and the actuator 11 _RR ,
The bypass pipe 46 for the left rear wheel and the right rear wheel, which branch off from the branch points 32a and 33a of the corresponding pipeline and bypass the rear wheel gate valve 29 and reach the branch point 25b upstream of the rear wheel gate valve 29. And a vehicle height lowering check valve 47 and a vehicle height lowering check valve 49.

Further, the vehicle height adjusting device 10 uses a path leading to the reserve tank 16 via the main pipe 23, the pump 20 and the suction pipe 21 for lowering the vehicle height. The pump 20 is a gear pump and stops rotating when the vehicle height drops.

Here, the structure of the pump 20 will be described with reference to a horizontal sectional view (FIG. 2) showing a gear portion of the pump 20 and a vertical sectional view (FIG. 3) showing an oil flow path of the pump 20. Reference numeral 100 in the figure denotes a casing, in which a gear housing 102 is provided. The gear housing 102 includes a drive gear 104
And the driven gear 106.
04 and the driven gear 106, the driving gear 1
04, a predetermined gap is formed between the tooth tip of the driven gear 106 and the inner wall surface of the gear housing 102.

The pump 20 has a suction passage 108.
Are provided between the suction port 108a and the gear storage section 102, and the discharge path 110 is provided between the gear storage section 102 and the discharge port 110a. Further, a suction pipe 21 is connected to the suction port 108a, and a main supply pipe 23 is connected to the discharge port 110a.
Is connected.

When oil is pressure-fed to the actuator 11i by the pump 20, the drive gear 104 and the driven gear 106 are rotated (in the direction indicated by the solid line in the figure), so that the oil flowing from the suction port 108a is sucked. The gear 108 is caused to flow into the gear housing 102 through the gear 108. In the gear housing 102, the oil is sucked into the tooth groove in the process of expanding the meshing portion, and is conveyed to the discharge path 110 along the inner wall surface of the gear housing 102. Accordingly, high-pressure oil is discharged from the discharge port 110a, and the oil is discharged from the actuator 1
1i can be pumped.

On the other hand, the oil discharged from the actuator 11i through the pump 20 is supplied to the reserve tank 16
In the case of recirculation, the driving gear 104 and the driven gear 1
06 rotation is stopped. Here, when the rotation of the driving gear 104 and the driven gear 106 is stopped, the discharge path 1
Since the pressure on the 10 side is higher than that on the suction path 108 side, the oil flowing into the gear housing 102 from the discharge path 110 is removed from the tooth tips of the drive gear 104 and the driven gear 106 and the inner wall surface of the gear housing 102. Is discharged to the suction passage 108 side through a gap formed between the suction tank 21 and the suction tank 21, and is returned to the reserve tank 16 through the suction pipe 21.

In the vehicle height adjusting device 10, oil is discharged from the actuator 11i and the vehicle height is lowered as described below, using the above-described configuration for each vehicle height lowering. In the following description, the actuator 11
_This is explained using _FL as an example.

The oil in the actuator 11 _FL is
The internal pressure of the actuator 11 _FL is discharged to the left front wheel conduit 30, but the vehicle height rise check valve 35 causes the branch point 24.
a from the branch point 30a and the bypass pipe 4 for the left front wheel.
Run out to 2. Upside down valve 43 for vehicle height lowering of this bypass pipe
Allows oil flow only from the left front wheel bypass pipe 42 to the branch point 24b of the front wheel supply pipe 24. Therefore, the oil discharged from the actuator _11FL flows from the left front wheel bypass pipe 42 into the front wheel supply pipe 24 bypassing the front wheel gate valve 27. In this case, since the front wheel leveling valve 26 has the two-way communication position 26a as described above, the oil passes through the main supply pipe 23 via the front wheel leveling valve 26. At the time of vehicle height descent, as described above, the discharge valve 41 takes the one-way communication position 41a, and the drain pipe 4
Since 0 is open, the oil discharged from the actuator 11 _FL is collected in the reserve tank 16 via the drain pipe 40.

The oil that has passed through the main supply pipe 23 has a high pressure on the discharge port 110a side of the pump 20, so that the oil flows into the pump from the discharge port 110a and flows out from the suction port 108a. Then, the suction pipe 21
And is collected in the reserve tank 16. Therefore, the actuator 11i from which the oil has been discharged as described above.
The vehicle height falls at the wheel corresponding to.

In addition, the vehicle height adjusting device 10 has a structure in which oil is forcibly recirculated to the reserve tank 16 when the pressure of the main supply pipe 23 rises carelessly.
A reflux pipe 50 is provided which branches off from the main supply pipe 23 and joins the drain pipe 40. The reflux pipe 50 is opened and closed by a relief valve 51. The relief valve 51 normally closes the conduit of the reflux pipe 50, but operates when the pressure of the pipeline upstream increases to connect the reflux pipe 50 to the drain pipe 40. Thus, when the pressure rises, the oil
Reserve tank 1 not supplied to actuator 11i
Reflux to 6. For this reason, since oil is not supplied to the actuator 11i at an inadvertently high pressure, damage to the actuator 11i is avoided.

Further, the vehicle height adjusting device 10 includes a vehicle height sensor 52i for each actuator 11i.
The vehicle height sensor 52i detects the vehicle height for each wheel, and outputs a detection signal representing the current vehicle height Hi corresponding to each wheel to the electronic control unit (ECU) 60.

The ECU 60 includes a CPU, a ROM, a RAM,
A microcomputer having a timer, etc.,
In addition to the vehicle height sensor 52i for each wheel, signals of a sensor switch group 61 including a vehicle speed sensor, a vehicle height setting switch, an ignition switch (IGSW), etc., and the main supply pipe 2
The signal of the pressure sensor 62 for detecting the pressure of No. 3 is taken in.
Then, based on these signals, the front wheel leveling valve 26, the rear wheel leveling valve 28 and the motor 22
Outputs various drive signals required for vehicle height adjustment to execute vehicle height adjustment processing.

The ECU 60 is provided with the damping force variable mechanism 15.
The variable aperture 14i is also connected to the actuator 1 by adjusting the aperture of the variable aperture 14i.
Also, a damping force changing process according to 1i is executed.

The vehicle height setting switch is operated by an occupant, and sets the vehicle height level to one of HIGH, NORMAL, and LOW in accordance with the operation position.
Output that signal. Vehicle height set by the vehicle height setting switch is to be the target vehicle height H _T of the case where the vehicle height adjustment of the vehicle.

Next, the vehicle height adjustment processing executed by the ECU 60 will be described with reference to the flowchart of FIG.

The flowchart of FIG. 4 shows the vehicle height adjustment processing, which is repeatedly executed at predetermined time intervals immediately after the operation of the IGSW switch. When the vehicle height adjustment process is started, first, the various sensors and switches described above are scanned to read signals necessary for vehicle height adjustment (step S100). The signal read in step S100 includes the detected vehicle speed from the vehicle speed sensor and the vehicle height sensor 52i.
From the vehicle height setting switch (i.e., the left front wheel height H _FL , the right front wheel height H _FR , the left rear wheel height H _RL and the right rear wheel height H _RR ). A setting signal.

Next, setting of the target vehicle height H _T is performed (step S101). That is, the passenger operates the vehicle height setting switch, HIGH as the level of the vehicle height, NORMAL, the target vehicle height H _T corresponding to the set level by selecting one of the levels of LOW is set. Also, when driving at a high speed (for example, at a speed of 80 km / h or more), the same target vehicle height H as when the NORMAL level is selected, even when the HIGH level is selected by the vehicle height setting switch, in order to improve running stability. _{Even if T} is set and NORMAL level is selected, L
The same target vehicle as selecting the OW level high H _T is set.

[0043] Subsequently, the detected current vehicle height Hi is determined whether match the target vehicle height H _T is performed (step S102).

[0044] When it is determined that the current vehicle height Hi and the target vehicle height H _T in step S102 coincide with each other, performs the maintenance of the vehicle height as no height adjustment is required (step S103). In this case, as described above, the ECU
The leveling valve for the front wheels 2
6. The rear wheel leveling valve 28 is positioned at the one-way communication position 26b, 28b.

On the other hand, if it is determined that the vehicle height Hi is currently different from the target vehicle height H _T in step S102, it calculates the vehicle height difference Δh between the target vehicle height H _T and the current vehicle height Hi, the car The vehicle height is adjusted so that the height difference Δh disappears.

[0046] That is, if it is determined that the current vehicle height Hi lower than the target vehicle height H _T (step S104), ECU
In response to the control signal from 60, the pump 20 is operated and the front wheel leveling valve 26 and the rear wheel leveling valve 28 are switched to the two-way communication positions 26a, 28a to adjust the vehicle height as described above ( Step S105).

Meanwhile, when it is determined that the current vehicle height Hi is higher than the target vehicle height H _T (step S104), ECU
In response to the control signal from 60, the pump 20 is stopped, the front wheel leveling valve 26 and the rear wheel leveling valve 28 are switched to the two-way communication positions 26a, 28a, and the discharge valve 41 is set to the one-way communication position 41.
Then, the vehicle height is adjusted as described above (step S106). In this case, the oil is returned not only from the main supply pipe 23 to the reserve tank 16 via the discharge valve 41 but also to the reserve tank 16 from the path via the pump 20.

Next, a description will be given of the vehicle height adjustment processing when the occupant gets on and off the vehicle. When the occupant of the passenger, of the signals read in ECU 60, target vehicle height H _T which is a target of the basis vehicle height adjusting vehicle height setting signal is set (step S10
1). That is, when the occupant gets on and off, the occupant operates the vehicle height setting switch to set the vehicle height level to the LOW level. As a result, the target vehicle height H _T according to the LOW level
Is set.

[0049] Subsequently, the detected current vehicle height Hi is determined whether match the target vehicle height H _T is performed (step S102). If the current is vehicle height Hi has a LOW level of the vehicle height, at step S102, it is determined that the current vehicle height Hi is equal to the target vehicle height H _T, the vehicle height as no height adjustment is required Is maintained (step S10).
3).

On the other hand, when it is determined that the current vehicle height Hi is higher than the target vehicle height H _T, i.e., when the vehicle height Hi currently has a HIGH level or NORMAL level vehicle height, ECU
In response to the control signal from 60, the pump 20 is stopped, the front wheel leveling valve 26 and the rear wheel leveling valve 28 are switched to the two-way communication positions 26a, 28a, and the discharge valve 41 is set to the one-way communication position 41.
The control is switched to "a" to adjust the vehicle height down to the LOW level vehicle height (step S106). In this case, oil is not only returned to the reserve tank 16 from the main supply pipe 23 via the discharge valve 41 but also
Is also returned to the reserve tank 16 from a route passing through the reservoir.

When the vehicle is driven after the occupant gets on the vehicle, the occupant operates a vehicle height setting switch to set a desired vehicle height level. As a result, the vehicle height adjustment processing according to the vehicle height level is performed.

As described above, in the vehicle height adjusting apparatus 10 according to the first embodiment, when the vehicle is lowered by discharging the oil from the actuator 11i, the discharge valve 4 is used.
Since the oil is discharged not only from the path 1 but also through the path through the pump 20, the speed of discharging the oil can be increased, and the vehicle height can be lowered in a short time.
Therefore, it is possible to improve the occupant's getting on and off.

Next, a vehicle height adjusting apparatus according to a second embodiment of the present invention will be described. The fluid circuit used in this vehicle height adjusting device is the same fluid circuit as the vehicle height adjusting device of the first embodiment shown in FIG. Also, this second
The pump used in this embodiment has the same configuration as the pump 20 used in the first embodiment shown in FIGS. 2 and 3, but supplies oil to the actuator 11i when the vehicle height drops. It is possible to rotate in a direction opposite to the case where the rotation is performed.

That is, at the time of vehicle height descent, the drive gear 104 and the driven gear 106 rotate in the opposite direction to the case where oil is pressure-fed to the actuator 11i (in FIG. 3, the direction of the dashed line arrow).
Let it. The oil that has flowed into the gear housing 102 from the discharge passage 110 is discharged to the suction passage 108 side by the drive gear 104 and the driven gear 106, and is returned to the reserve tank 16 via the suction pipe 21.

When the vehicle height is lowered by the vehicle height adjusting device, the pump 20 is stopped and the front wheel leveling valve 26 and the rear wheel leveling valve 28 are set in the bidirectional communication position according to a control signal from the ECU 60. 26
a, 28a, the discharge valve 41 is switched to the one-way communication position 41a, and the vehicle height is lowered as described above.

In this case, the oil is not only returned to the reserve tank 16 from the main supply pipe 23 via the discharge valve 41, but also the pump 20 is driven by the actuator 11i.
Since the oil is supplied in the opposite direction to the case where oil is supplied, the oil is returned to the reserve tank 16 also from the path passing through the pump 20.

In the vehicle height adjusting process according to the second embodiment, "stop pump" in step S106 of the flowchart used in the first embodiment as shown in FIG. 4 is replaced with "rotate pump in the opposite direction". It can be implemented in.

As described above, in the vehicle height adjusting device 10 according to the second embodiment, when the vehicle is lowered by discharging the oil from the actuator 11i, the discharge valve 4 is used.
1 as well as oil from the path passing through the pump 20, and the pump drive gear 104 and the driven gear 1
06 is rotated in the opposite direction to the case where oil is supplied to the actuator, so that more oil can be discharged in a shorter time than in the first embodiment, and the vehicle height can be reduced in a very short time. It can be carried out. Therefore, the occupant's getting on and off can be further improved.

[0059] In the embodiments described above, but conducted in accordance with the setting of the target vehicle height H _T of the time the occupant getting on and off only the setting signal of the vehicle height setting switch is not limited to this IGS
The target vehicle height at the time of getting on and off the occupant according to any of the conditions such as turning off the W, opening the door, the vehicle speed being 0, and applying the parking brake, or a combination of these conditions. It is also possible to set H _T.

Further, in the above-described embodiment, when the occupant operates the vehicle height setting switch when getting on and off, the LO
The vehicle height is lowered to the W level, but the height is not limited to this, and an occupant getting on and off level that allows the vehicle height to be even lower than the LOW level vehicle height is provided, and the vehicle height is lowered to this level You may make it do. In this case, the occupant's getting on and off can be further improved.

In the above-described embodiment, the fluid pressure actuator is configured as a cylinder piston device which is supplied and discharged with oil as a working fluid and expands and contracts. However, the present invention is not limited to this. May be employed, and a diaphragm having a closed space interposed between the wheel and the vehicle body may be employed as the fluid pressure actuator.

[0062]

According to the present invention, the working fluid discharged from the actuator at the time of vehicle height descent returns to the reserve tank via the fluid pressure source as well as the discharge valve, so that the vehicle height descent speed is increased. And the occupant getting on and off can be improved.

When the fluid pressure source is driven in the opposite direction to the supply of the working fluid to the actuator when the vehicle descends, a large amount of working fluid should be discharged at a high speed via the fluid pressure source. The vehicle height descent speed can be further increased, and the occupant's getting on and off can be significantly improved.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram schematically showing a fluid circuit of a vehicle height adjusting device.

FIG. 2 is a horizontal sectional view showing a gear section of the pump.

FIG. 3 is a vertical sectional view showing an oil flow path of a pump.

FIG. 4 is a flowchart illustrating a vehicle height adjustment process executed by an ECU.

[Explanation of symbols]

10 vehicle height adjustment device, 11 _FL , 11 _FR , 11 _RL , 11 _RR
... actuator, 20 ... pump, 23 ... main supply pipe, 24 ... front wheel supply pipe, 25 ... rear wheel supply pipe, 26 ...
Leveling valve for front wheel, 27 ... Gate valve for front wheel,
28: rear wheel leveling valve, 29: rear wheel gate valve, 41: exhaust valve, 52 _FL , 52 _FR , 52 _RL , 5
2 _RR : Height sensor, 60: ECU, W _FL : Left front wheel, W _FR
… Right front wheel, W _RL … left rear wheel, W _RR … right rear wheel.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masaro Tabata 1 Toyota Town, Toyota City, Aichi Prefecture, Toyota Motor Corporation (72) Inventor Shoichi Shono 1 Toyota Town, Toyota City, Aichi Prefecture, Toyota Motor Corporation ( 72) Inventor Kazuo Ogawa 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation

Claims (2)

[Claims] 1. A fluid pressure actuator interposed between a wheel and a vehicle body for increasing or decreasing a vehicle height of a corresponding portion by supplying and discharging a working fluid, and stored in a reserve tank in the fluid pressure actuator. A fluid pressure source for supplying a working fluid, a discharge passage for discharging the working fluid from the fluid pressure actuator to the reserve tank, and a discharge valve that controls the communication of the discharge passage. The vehicle height adjusting device may be configured to open the discharge valve, stop driving the fluid pressure source, and discharge the working fluid to the reserve tank via the fluid pressure source. 2. A hydraulic actuator interposed between a wheel and a vehicle body for increasing / decreasing a vehicle height of a corresponding part by supplying / discharging a working fluid, and a hydraulic actuator stored in a reserve tank in the hydraulic actuator. A fluid pressure source for supplying a working fluid, a discharge passage for discharging the working fluid from the fluid pressure actuator to the reserve tank, and a discharge valve that controls the communication of the discharge passage. Sometimes, while opening the discharge valve,
A vehicle height adjusting device, wherein the fluid pressure source is driven in a direction opposite to the direction of supply of the working fluid to the actuator, and the working fluid is discharged to the reserve tank via the fluid pressure source.