JPH02162114A - Car height regulation device for vehicle - Google Patents

Abstract

PURPOSE:To suppress a feeling of disorder following a sudden car height variation by feeding an operation fluid from a control valve to an operation fluid chamber through a one-way passage device in the stage when the operation fluid feeding pressure is less than a specific value, at the starting of operation of a car height regulation device for automobile. CONSTITUTION:When a car height regulation is started to operate, and in the stage when the operation fluid feeding pressure, that is, the pressure of the operation fluid feeding passages to operation fluid chambers 2FR-2RL, does not reach a specific value, the operation fluid is fed to the operation fluid chambers 2FR-2RL from control valves 40-46 for regulating the car heights, not through cutoff valves 197FR-197RL, but through a one-way passage which is composed of passages 197FR-197RL and check valves 199FR-199RL. By such a constitution, the pressures at the front side and at the rear side of the cutoff valves are made practically equal a large amount of operation fluid flow when the cutoff valves are opened can be suppressed, and a feeling of disorder following a sudden car height variation can be prevented.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a vehicle height adjustment device for a vehicle such as an automobile.

Conventional technology Vehicle height adjustment devices for vehicles such as automobiles have conventionally generally included an actuator that increases or decreases the vehicle height by supplying and discharging working fluid to a working fluid chamber, and an actuator that supplies working fluid to the working fluid chamber. A fluid supply passage means, a working fluid discharge passage means for discharging the working fluid from the working fluid chamber, a connecting passage means communicating with the working fluid chamber, and a connecting passage means and the working fluid supply passage means or the working fluid discharge passage means. It has a control valve that is selectively connected for communication and controls supply and discharge of working fluid to and from the working fluid chamber.

In such a vehicle height adjustment device, when the pump that supplies high-pressure working fluid to the working fluid supply passage means is stopped, or when an abnormality occurs in the working fluid supply passage means, the working fluid may flow out from the working fluid chamber. In order to prevent the vehicle height from decreasing due to It is already known to incorporate an on-off valve in the middle of the means.

Problems to be Solved by the Invention In a vehicle height adjustment device incorporating such an on-off valve, when the on-off valve is opened with a relatively large differential pressure existing on both sides of the on-off valve at the start of its operation, Since a relatively large amount of working fluid flows through the on-off valve when the on-off valve is opened, there is a problem in that the vehicle height temporarily fluctuates rapidly, giving a sense of discomfort to the occupants of the vehicle.

This problem arises when the control valve is a pressure control valve, and the on-off valve is a pressure control valve, as shown in FIGS. This is particularly noticeable when the shutoff valve is configured to open in response to the pressure in the working fluid supply passage means upstream of the control valve being equal to or higher than a predetermined value. That is, in such a vehicle height adjustment device, when the vehicle height adjustment device starts operating, the pressure in the working fluid supply passage means upstream of the pressure control valve rises from a predetermined value or less, and at the stage when the pressure reaches the predetermined value or more. Because the shutoff valve opens, it is not possible to know exactly when the shutoff valve opens, and therefore it is not possible to know the control pressure of the pressure control valve at the time when the shutoff valve opens. .

The present invention has been developed in view of the above-mentioned problems in conventional vehicle height adjustment devices in which an on-off valve is incorporated between a control valve and an actuator, and the above-mentioned previously proposed vehicle height adjusting device. To provide a vehicle height adjustment device that is improved so as not to give a sense of discomfort to a vehicle occupant due to a temporary and rapid change in vehicle height when the valve is activated. The purpose is

Means for Solving the Problems According to the present invention, an actuator that increases or decreases the vehicle height by supplying and discharging a working fluid to and from a working fluid chamber, and a vehicle height detecting means that detects the vehicle height. a working fluid supply passage means for supplying working fluid at a supply pressure to the working fluid chamber; a working fluid discharge passage means for discharging the working fluid from the working fluid chamber; and a connecting passage means communicating with the working fluid chamber. , a cutoff valve that is provided in the middle of the connecting passage means and opens in response to the supply pressure being equal to or higher than a predetermined value; and the working fluid supply passage means or the working fluid discharge passage means and the connecting passage means. a control valve that selectively communicates and connects the control valve; one-way passage means that bypasses the cutoff valve and allows only the flow of working fluid from the control valve toward the working fluid chamber; and control means that controls the control valve. The vehicle height is detected by the vehicle height detection means by supplying working fluid from the control valve to the working fluid chamber via the one-way passage means when the supply pressure is less than the predetermined value at the start of operation. This is achieved by a vehicle height adjustment device configured to increase the vehicle height by a predetermined amount from the initial vehicle height.

Effects and Effects of the Invention According to the configuration as described above, when the vehicle height adjustment device starts operating, the supply pressure of the working fluid, that is, the pressure in the working fluid supply passage means upstream of the control valve, reaches a stage below a predetermined value. By supplying working fluid from the control valve to the working fluid chamber through the one-way passage means, the vehicle height is increased by a predetermined amount from the initial vehicle height detected by the vehicle height detecting means, and the vehicle height is therefore shut off. At the stage when the isolation valve is opened, the pressures of the working fluid in the connecting passage means before and after the valve are substantially equal to each other, avoiding the existence of large differential pressures on both sides of the isolation valve. Reliably prevents temporary and sudden changes in vehicle height due to the rapid flow of a large amount of working fluid through the shutoff valve, and any discomfort caused to vehicle occupants due to such changes in vehicle height. can do.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention will be explained in detail below by way of example embodiments with reference to the accompanying figures.

Embodiment FIG. 1 is a schematic structural diagram showing one embodiment of a vehicle height ':A adjustment lid device according to the present invention. The illustrated vehicle height adjustment device includes actuators IFR, 11F L, and IRI? provided corresponding to the front right wheel, front left wheel, rear right wheel, and rear left wheel of the vehicle, which are not shown in the figure, respectively. , IRL, and these actuators have working fluid chambers 2PR, 2, respectively.
It has PL, 2RR, and 2RL.

Further, in the figure, 4 indicates a reserve tank that stores hydraulic oil as a working fluid, and the reserve tank 4 is connected to a suction flow path 10 in which a filter 8 for removing foreign matter is provided in the middle.
It is connected in communication with the suction side of the pump 6. A drain passage 12 is connected to the pump 6 for collecting working fluid leaked inside the pump 6 into the reserve tank 4. The pump 6 is rotationally driven by an engine 14, and the engine 140 rotation speed is detected by a rotation speed sensor 16.

A high pressure flow path 18 is connected to the discharge side of the pump 6.

A check valve 20 is provided in the middle of the high-pressure flow path 18 to allow only the flow of working fluid from the pump toward each actuator, and between the pump 6 and the check valve 20, the working fluid discharged from the pump is provided. An attenuator 22 is provided to absorb pressure pulsations and reduce pressure changes. The high pressure flow path 18 includes a front wheel high pressure flow path 18F and a rear wheel high pressure flow path 1.
8R is connected to one end, and accumulators 24 and 26 are connected to these high pressure channels, respectively.

Each of these accumulators has a high pressure gas sealed therein so as to absorb pressure pulsations of the working fluid and perform a pressure accumulating function.

Further, one end of the high pressure flow path 181'R for the right front wheel, the high pressure flow path 18FL for the left front wheel, the high pressure flow path 18RR for the right rear wheel, and the high pressure flow path 18RL for the left rear wheel are connected to the high pressure flow paths 18F and 18R, respectively. There is. High pressure channel 18? , 181'L,
181? Filter 2 is installed in the middle of R and 18RL.
8PR, 281'L, 281? R, 281? The other ends of these high pressure channels are connected to the P boat of the pilot-operated three-boat switching control valve 40.42.44.46 of the pressure control valve 32.34.36.38, respectively. ing.

The pressure control valve 32 is connected to the switching control valve 40 and the high pressure flow path 18P.
It consists of a flow path 50 that communicates and connects the low pressure flow path 48FR for the right front wheel, and a fixed throttle 52 and a variable throttle 54 provided in the middle of the flow path.

A low pressure passage 48FR is connected to the R boat of the switching control valve 40, and a connection passage 56 is connected to the A boat. The switching control valve 40 has a fixed throttle 52 and a variable throttle 54.
It is a spool valve that takes in the pressure Pp in the flow path 50 between the When the pressures Pp and Pa are equal to each other, the switching position 40b switches to the switching position 40b, which cuts off communication between all boats when the pressures Pp and Pa are equal to each other.
When the pressure is lower than the pressure Pa, the switch is switched to a switching position 40c that connects the boat R and the boat A in communication. Further, the variable throttle 54 changes the effective passage cross-sectional area of the throttle by controlling the current applied to the solenoid 58, thereby changing the pressure Pp in cooperation with the fixed throttle 52.

Similarly, pressure control valves 34 to 38 are each pressure control valve 32
A pilot-operated three-port switching control valve 42, 44, 46 corresponding to the switching control valve 40, a flow path 60, 62, 64 corresponding to the flow path 50, and a fixed throttle 66, 68 corresponding to the fixed throttle 52. .70 and variable apertures 72, 74, and 76 corresponding to the variable aperture 54, and the variable apertures 72 to 76 each have a solenoid 78, 80, and 82.

In addition, the switching control valves 42, 44, and 46 are switching control valves 40
The R boat has a low pressure flow path 481'L for the left rear wheel and a low pressure flow path 48 for the right rear wheel.
RR, low pressure flow path 481 for left rear wheel? One end of L is connected, and the A boat has connection channels 84, 86, 8, respectively.
One end of 8 is connected. In addition, the switching control valves 42 to 4
6 is the pressure Pp in the flow passages 60 to 64 between the corresponding fixed throttle and variable throttle, and the corresponding connection flow passages 84 to 8.
It is a spool valve that takes in the pressure Pa in 8 as a pilot pressure, and when the pressure Pp is higher than the pressure Pa, the switching positions 42a and 44 connect the boat P and the boat A for communication.
a, 46a, and the switching position 4 cuts off the communication of all boats when the pressures Pp and Pa are equal to each other;
2b, 44b, and 46b, and when the pressure Pp is lower than the pressure Pa, the switching positions are switched to switching positions 42c, 44c, and 46c for communicating and connecting the boat R and the boat A.

As schematically shown in FIG. 1, each actuator IFR, IPL, IRR, IRL has a cylinder 106PR, 106PL, 106RR, 106, respectively.
RL, and working fluid chambers 2PR, 2PL, and 2RR that fit into the corresponding cylinders and work together with the corresponding cylinders.
, 2R1, pistons 108PR, 108P+
, , 108RR, 108RI, each connected to the vehicle body (not shown in the figure) through a cylinder, and connected to a suspension arm (not shown in the figure) at the tip of the piston rod. . Also, the cylinders 1061'R, 106FL, 106 of each actuator
RI? , 1061? L has drain channels 110.112.
114 and 116 are connected.

The other end of the drain passage 110, 112, 114, 116 is connected to a drain passage 118, which is connected to the reserve tank 4 via a filter 120, thereby preventing leakage from the working fluid chamber. The used working fluid is returned to the reserve tank.

Accumulators 132.134.136.138 are connected to the working fluid chambers 2PR, 2PL, 2RR, and 2R1 via throttles 124.126.128.130, respectively. Also piston 108PR, 108Fl4.1
08 RT? , 108RL has a flow path 140PR, respectively.
,140F+4.140RR,140t? 1. is provided. These channels are respectively corresponding channels 56.
84 to 88 and working fluid chambers 2PR, 2P+1.2 RR.

2RL, and a filter 142 is installed in the middle of each.
1'R, 142r'L, 142RR, 142RL. Also, actuator I PR, 11'L,
I R1? , a vehicle height sensor 144F that detects the distance between the vehicle body and the corresponding wheel is located close to the IRL.
h, 144PL, 144RR11441? L is provided.

Pilot-operated shutoff valves 150.152.154.156 are provided in the middle of the connecting channels 56.84 to 88, respectively, and these shutoff valves are connected to corresponding pressure control valves 40.42.44.46, respectively. High pressure flow path 1 on the more upstream side
When the differential pressure between the pressure in 8PR, 18PL, 18RR, and 18RL and the pressure in drain flow path 110.112.114.116 is equal to or higher than a predetermined value, the valve is maintained in an open state. In addition, the portions between the corresponding pressure control valves and the cutoff valves of the connecting channels 56.84 to 88 are respectively connected to the channel 15.
8.160.162.164 communicates with the portion downstream of the variable throttle of the flow path 50.60.62.64 of the corresponding pressure control valve. Relief valves 166, 168, 170, 17 are provided in the middle of the flow paths 158 to 164, respectively.
2 are provided, and each of these relief valves takes in the pressure of the upstream portion of the corresponding flow path 158, 160, 162, 164, that is, the corresponding connection flow path side, as a pilot pressure, and the pilot pressure is When a predetermined value is exceeded, the valve is opened to guide a portion of the working fluid in the corresponding connection flow path to the flow paths 50, 60 to 64.

In addition, the shutoff valves 150 to 156 are connected to the high pressure flow path 18F'R, respectively.
, 18PL, 18RR, and 18RL may be configured to maintain the valve open state when the differential pressure between the pressure inside them and the atmospheric pressure is equal to or higher than a predetermined value.

The other ends of the low pressure passages 48PR and 48['L are connected to one end of the low pressure passage 48F for the front wheels, and the other ends of the low pressure passages 48RR and RL are connected to one end of the low pressure passage 48R for the rear wheels. has been done. The other ends of the low pressure channels 48F and 48R are connected to one end of the low pressure channel 48 in communication. The low pressure flow path 48 has an oil cooler 174 in the middle and a filter 17 at the other end.
It is connected to the reserve tank 4 via 6. A portion of the high-pressure flow path 18 between the check valve 20 and the attenuator 22 is connected to the low-pressure flow path 48 through a flow path 178 . A relief valve 180 is provided in the middle of the flow path 178 and is set to a predetermined pressure in advance.

In the illustrated embodiment, the high pressure channel 18R and the low pressure channel 4
8R is a flow path 188 that has a filter 182, a throttle 184, and a normally open electromagnetic on-off valve 186 that can adjust the flow rate.
are connected to each other by. The electromagnetic on-off valve 186 is configured to open by energizing a solenoid 190 and changing its excitation current, and to adjust the flow rate of the working fluid passing through the valve. Also, the high pressure flow path 181
? and the low-pressure flow path 48R are connected to each other by a flow path 194 having a pilot-operated on-off valve 192 in the middle. The on-off valve 192 takes in the pressure on both sides of the throttle 184 as a pilot pressure, and when there is no differential pressure on both sides of the throttle 184, it maintains the valve closed position 192a, and the pressure on the side of the high-pressure flow path 18 with respect to the throttle 184 is high. At times, the valve is switched to the valve open position 192b. Thus aperture 1
84, the electromagnetic on-off valve 186 and the on-off valve 192 cooperate with each other to open the high pressure flow path 18R and the low pressure flow path 481? Therefore, a bypass valve 196 is configured that selectively connects the high-pressure flow path 18 and the low-pressure flow path 48 to control the flow rate of the working fluid flowing from the high-pressure flow path to the low-pressure flow path.

Further, in the illustrated embodiment, a pressure sensor 198 is provided in the high-pressure flow path 18H, and the pressure of the working fluid in the high-pressure flow path is detected by the pressure sensor. In addition, the connection flow paths 56.84.86.88 include flow paths 197PR and 197PL that bypass the corresponding cutoff valves, respectively.
197RI? , 1971? A check valve 1991 is connected to each of these flow paths, and each of these flow paths is provided with a check valve 1991 that allows only the flow of working fluid from the pressure control valve toward the actuator. ,1
99PL, 199RR, 199RL are provided,
These flow paths and check valves cooperate with each other to define a one-way flow path that allows flow of working fluid only from the corresponding pressure control valve toward the working fluid chamber of the corresponding actuator.

The electromagnetic on-off valve 186 and the pressure control valves 32-38 are controlled by an electric control device 200 shown in FIG. Electrical control device 200 includes a microcomputer 202 .

The microcomputer 202 may have a general configuration as shown in FIG. 2, and includes a central processing unit (CPU) 204 and a read-only memory (ROM) 2.
06, random access memory (RAM) 208,
It has a human powered boat device 210 and an output port device 212, which are connected to each other by a bidirectional common bus 214. The input port device 210 receives a signal indicating the rotation speed N of the engine 14 from the rotation speed sensor 16, a signal indicating the pressure Ps in the high pressure flow path from the pressure sensor 198, and an ignition switch (IGSW) 216 indicating that the ignition switch is in the on state. A signal indicating whether or not the switch is on from an emergency engine switch (EMSW) 218 provided in the vehicle interior and operated by a vehicle occupant, a vehicle height sensor 1441'l
? , 1441"L, 144RR, and 144RL indicate the vehicle height Hi (+-1'RSRL, RR, RL) of the parts corresponding to the right front wheel, left front wheel, right rear wheel, and left rear wheel, respectively. The human-powered boat device 210 appropriately processes the signals input thereto, and
Based on the program stored in OM206 <CPU2
According to the instruction of 04, the processed signal is output to L% CPU and RAM2o8. ROM206
stores the control flow shown in FIG. 3 and the maps shown in FIGS. 4 to 7.

According to instructions from the CPU 204, the output port device 212 outputs a control signal to the electromagnetic on-off valve 186 via a drive circuit 220, and outputs a control signal to the pressure control valves 32-3 via drive circuits 222-228.
8.In detail, variable aperture 54.72.74.76
A control signal is output to the solenoids 58, 78, 80, and 82 of the controller, and the control signal is output to the display 232 via the drive circuit 230.

The operation of the illustrated embodiment will now be described with reference to the flowchart shown in FIG.

Note that the control flow shown in FIG. 3 is started when the ignition switch 216 is closed. In the flowchart shown in FIG. 3, flag Fr is related to whether or not there is a failure in any part of the vehicle height adjustment device, and 1 indicates whether or not there is a failure in any part of the vehicle height adjustment device. The flag Fe indicates whether or not the engine is in operation, 1 indicates that the engine is in operation, and the flag Fs indicates whether or not the engine is in operation. Increase in vehicle height by a predetermined amount, 1
This relates to whether or not the adjustment has been completed, and 1 indicates that the adjustment to increase the vehicle height by a predetermined amount has been completed.

First, in step 10, a main relay (not shown in the figure) is turned on, and then in step 2
Go to 0.

In step 20, the contents stored in the RAM 208 are cleared and all flags are reset to 0, and the process then proceeds to step 30.

In step 30, a signal indicating the rotation speed N of the engine 14 detected by the rotation speed sensor 16, a signal indicating the rotation speed N of the engine 14 detected by the rotation speed sensor 16,
98, a signal indicating whether the ignition switch 216 is in the on state, a signal indicating whether the EMSW 218 is in the on state, vehicle height sensors 144FR, 144PL. , 14
A signal indicating the vehicle height Hi detected by 4RR and 144RL is read, and then the process proceeds to step 40.

The vehicle height H1 read in the first step 30 after the main relay is turned on is stored in the RAM 208 as the initial vehicle height HoI until the main relay is turned off.

In step 40, it is determined whether or not the ignition switch is in the off state, and when it is determined that the ignition switch is in the off state, the process proceeds to step 240, where it is determined that the ignition switch is in the off state. When it is determined that this is the case, the process advances to step 50.

In step 50, it is determined whether or not the EMSW is in the on state, and when it is determined that the EMSW is in the on state, the process proceeds to step 220, where it is determined that the EMSW is not in the on state. When the determination has been made, the process advances to step 60.

In step 60, it is determined whether or not the flag Ff is 1, and when it is determined that it is Fl'-1, the process proceeds to step 220, and it is determined that it is not Ff'-1. When this has been carried out, the process advances to step 70.

In step 70, whether or not the engine is being operated is determined by determining whether the engine rotation speed N detected by the rotation speed sensor 16 and read in step 32 exceeds a predetermined value. If it is determined that the engine is not being operated, the process proceeds to step 110, and if it is determined that the engine is being operated, the process proceeds to step 80.

Note that whether or not the engine is being operated may be determined by determining whether or not the generated voltage of a generator (not shown in the drawings) driven by the engine is equal to or higher than a predetermined value.

In step 80, flag FQ is set to 1,
After that, proceed to step 9o. In this case, if the flag Fc has already been set to 1, it remains in that state.

In step 90, the current 1b applied to the solenoid 190 of the electromagnetic on-off valve 1.86 of the bypass valve 196 is R.
Based on the map corresponding to the graph shown in FIG. 4 stored in the OM 206, calculation is performed according to Ib-1b+ΔI bs , and the process then proceeds to step 100.

In step 100, the current 1b calculated in step 9o is applied to the solenoid 190 of the electromagnetic on-off valve 186, thereby driving the bypass valve 196 in the closing direction, and then the process proceeds to step 130.

In step 110, it is determined whether the flag Fe is 1 or not. When it is determined that the flag Fe is Fe -1, that is, it is determined that the engine has stopped after being started, step 120 is performed. Proceed to and determine that it is not Fe-1.
That is, when it is determined that the engine has not been started at all, the process advances to step 130.

In step 120, the flag Fs is reset to 0, and the process then proceeds to step 220. In this case, if the flag Fs is O, it is maintained at zero.

In step 130, it is determined whether or not the flag Fs is 1, and when it is determined that it is Fs-1, the process proceeds to step 160, and it is determined that Fs is not 1. If so, the process proceeds to step 140.

In step 140, it is determined whether the vehicle height has been increased by a predetermined amount ΔHsi from the initial vehicle height Hol that was first read in step 30 when the vehicle height adjustment device started operating according to the following formula. When the determination is made and it is determined that the adjustment to increase the vehicle height by a predetermined amount has not been completed, the process proceeds to step 170, and when it is determined that the adjustment to increase the vehicle height by the predetermined amount has been completed. Proceed to step 150.

Old≧Hoi+ΔHsl Note that the predetermined amount ΔHsi is the predetermined value Ps of the pressure Ps in the high pressure flow path.
The increment ΔI bs of the current 1b in the calculation of step 90 is set so that the vehicle height increase adjustment by a predetermined amount is completed before the cut-off valve opens and a YES determination is made in step 170. is set to a predetermined value in relation to.

In step 150, the flag Fs is set to 1, and then the process proceeds to step 160.

In step 160, the vehicle height adjustment amount ΔH1 at the position corresponding to each wheel is calculated as the deviation between the vehicle height H1 at the position corresponding to each wheel read in step 30 and the reference vehicle height Ha1.
is calculated according to the following formula, and then step 180
Proceed to.

ΔOld Adjustment Old-Hal Note that the calculation of the vehicle height 33 adjustment amount ΔHi in this step does not constitute a part of the present invention, and therefore the vehicle height adjustment amount may be calculated in other ways.

In step 170, the vehicle height increase adjustment amount ΔH1 at the start of operation of the vehicle height adjustment device is calculated according to the following formula, and then the process proceeds to step 180.

ΔOld−*Hoi+ΔHsl−Old In step 180, in order to adjust the vehicle height adjustment amount ΔH1 calculated in step 160 or step 170, a map corresponding to the graph shown in FIG. Based on this, the current It to be energized to the solenoids 58,78-82 of the variable throttles 54,72-76 of each pressure control valve is calculated, and then the process proceeds to step 260.

In step 190, the solenoid 190 of the electromagnetic on-off valve 186 of the bypass valve 196 is adjusted based on the map corresponding to the graph shown in FIG. 6 stored in the ROM 206.
The current 1b to be passed through 7u is calculated by Ib = 1b - ΔIbc, and then the process proceeds to step 200.

In step 200, the current 1b calculated in step 190 is applied to the solenoid 190, thereby driving the bypass valve 196 in the opening direction, and then the process proceeds to step 260.

In step 210, as shown in FIG.
Time from when the ignition switch is turned off to when the main relay is turned off Tol
It is determined whether or not the timer related to 'l' is activated, and when it is determined that the Torr timer is activated, the process proceeds to step 230, where it is determined that the Toll 'f' timer is not activated. When the determination has been made, the process advances to step 220.

In step 220, the Tofr timer is started, and the process then proceeds to step 230.

In step 230, based on the map corresponding to the graph shown in FIG.
b is Ib-1b-ΔIb.

After that, the process proceeds to step 240.

In step 240, the current 1b calculated in step 230 is applied to the wire 190 of the electromagnetic on-off valve 186, thereby driving the bypass valve 196 in the opening direction, and then the process proceeds to step 250.

In step 250, it is determined whether or not the time To ('f') has elapsed, and when it is determined that the time Torl' has elapsed, the process proceeds to step 350, where the time T
If it is determined that of'f' has not elapsed, the process advances to step 260.

In step 260, step 90.190.23
It is determined whether the current 1b calculated at 0 is greater than or equal to the reference value Ibo, and Ib≧lb.

If it is determined that Ib is not true, the process proceeds to step 290, and if it is determined that Ib≧Ibo, the process proceeds to step 270.

In step 270, it is determined whether the pressure Ps of the working fluid in the high pressure flow path read in step 30 is greater than or equal to the basic value Pso, and it is determined that Ps≧PSO. is performed, the process advances to step 290, and Ps
When it is determined that ≧Pso, step 2
Proceed to 80.

In step 280, the current II calculated in step 180 is applied to the variable throttle solenoid 5 of each pressure control valve.
8. Each pressure control valve is driven by the output from 78 to 82 to adjust the vehicle height, and then step 290
Proceed to.

In step 290, it is determined whether or not there is a fail at any location within the vehicle height adjustment device, and if it is determined that there is no fail, the process proceeds to step 310, where the fail is detected. If it is determined that the file exists, the process advances to step 300.

In step 300, the fail flag Fr is set to 1, and then the process proceeds to step 310.

In step 310, diagnosis processing is performed for each part of the vehicle height adjustment device, and if an abnormality such as a failure exists, a code number indicating the location is displayed on the display 2.
32, and if there is no abnormality in any part, proceed to step 3 without displaying the code number on the display.
0, and steps 30 to 310 described above are repeated.

In step 320, the main relay is turned off, thereby ending the control flow shown in FIG. 3 and stopping power to the electric control device 200 shown in FIG. Ru.

Thus, according to this embodiment, when the vehicle height RJ adjusting device starts operating, a negative determination is first made in steps 40 to 60, and a negative determination is made in step 70 while the engine has not started yet. A determination is made. When the engine is started after a period of time has passed since the ignition switch was closed, a YES determination is made in step 70, and the bypass valve is gradually closed in steps 90 and 100. As a result, the pressure P in the high pressure flow path
s is gradually increased.

In this process, in step 170, the vehicle height is increased by a predetermined amount ΔHsi from the initial vehicle height Hot when the vehicle height adjustment device starts operating; 2! Increased adjustment amount ΔH of vehicle height to achieve normalization
1 is calculated, and the control current 1i to be supplied to the pressure control valve in order to carry out the adjustment of this ΔHI is calculated in step 180. The pressure control valve is controlled by the control current, thereby achieving an increase adjustment of the vehicle height by a predetermined mHsi.

Furthermore, when the predetermined amount of vehicle height increase adjustment is achieved, the flag Fs is set to 1 in step 150, and thereafter a YES determination is made in step 130, and normal vehicle height adjustment is performed. control.

As mentioned above, when the vehicle height is increased by a predetermined amount: A adjustment is achieved,
Check valve 199PR, 199PL, 199RR, 1991
? Flow paths 197I'R and 197r on the upstream and downstream sides of L
'L, 197RR, 197RL are substantially equal to each other, and therefore the pressures in the connecting passages on both sides of each shutoff valve are also substantially equal to each other, which subsequently causes the pressure Ps in the high pressure passage to be at a predetermined level. Even if the value PSO increases, each isolation valve opens with the pressures in the connecting passages on both sides thereof being substantially equal to each other, so that a large amount of working fluid flows rapidly through it when the isolation valve opens. It is possible to reliably prevent the vehicle height from suddenly and temporarily changing due to this, and from giving a sense of discomfort to the occupants of the vehicle due to such a change in the vehicle height.

In this case, as mentioned above, when the vehicle height adjustment device starts operating, the bypass valves are gradually closed, thereby gradually increasing the pressure in the high-pressure flow path, and as a result, each cutoff valve is gradually opened. Even if there is some pressure difference on both sides of each shutoff valve, it is possible to avoid a temporary sudden change in the vehicle height when the shutoff valve opens, and therefore the predetermined amount of pressure at the start of operation as described above can be avoided. High precision is not required to control the increase adjustment of the vehicle height.

Furthermore, before each shutoff valve opens, the vehicle height must be increased by a predetermined amount5.
1! The pressure P in the high pressure flow path detected by the pressure sensor 198 before step 130 is performed so that
Determine whether s is greater than or equal to a predetermined value Pso, and determine whether Ps≧P
When it is determined that it is not so, step 13
0, and when it is determined that Ps≧PSO, the process may proceed to step 160.

Although the present invention has been described in detail with respect to specific embodiments above, the present invention is not limited to such embodiments, and various other embodiments are possible within the scope of the present invention. This will be clear to those skilled in the art.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing one embodiment of a vehicle height adjustment device according to the present invention, FIG. 2 is a block diagram showing an electric control device of the embodiment shown in FIG. 1, and FIG. The figure is a flowchart showing the control flow achieved by the electric control device shown in FIG. 2, and FIGS.・
A graph showing a map used when calculating the current Ib supplied to the bypass valve when the operation is stopped in the 11th state, Fig. 7 shows the relationship between the vehicle height adjustment amount ΔH1 and the pressure control valve mouth ■ variable throttle solenoid. It is a graph showing the relationship between supplied current 1i. I PR, I FL, IRR, IRL... Actuator, 2PR12PL, 2RR, 2RL... Working fluid chamber, 4... Reserve tank, 6... Pump, 8
...filter, 10...intake channel, 12...drain channel, 14...engine. 16... Rotation speed sensor, 18... High pressure flow path, 20...
...Check valve, 22...Attenuator, 24.26.
...Accumulator, 32.34.36.38...Pressure control valve, 40.42.44.46...Switching control valve, 48...Low pressure flow path, 52...Fixed throttle, 54...
・Variable aperture. 56... Connection flow path, 58... Solenoid, 66.6
8.70...fixed aperture, 72.74.76...variable aperture. 78.80.82...Solenoid, 84.86.88
... Connection channel, 110-118... Drain channel, 1
20...Filter, 124-130...Aperture, 13
2-138...Accumulator, 144PR, 144
P.L. 1441? R11441? L...Vehicle height sensor, 50~
156...Shutoff valve, 166-172...Relief valve, 174...Oil cooler, 176...Filter,
180... Relief valve, 182... Filter, 18
4... Throttle, 186... Solenoid shut-off valve, 190...
Solenoid, 192...Opening/closing valve, 196...Bypass valve, 198.199...PR, 199FL, 199
RR, 199R1,... Check valve. 200... Electric control device, 202... Microcomputer, 204... CPU, 206... ROM
, 208...RAM, 210...input boat device,
212... Output port device, 216... Ignition switch, 218... EMSW, 220-230
...Drive circuit, 232...Display device patent application Attorney Toyota Motor Corporation

Claims (1)

[Claims] an actuator that increases or decreases a vehicle height by supplying and discharging a working fluid to and from a working fluid chamber; a vehicle height detection means that detects the vehicle height; and a working fluid supply passage that supplies working fluid at a supply pressure to the working fluid chamber. a working fluid discharge passage means for discharging the working fluid from the working fluid chamber; a connecting passage means communicating with the working fluid chamber; a shutoff valve that opens in response to this, a control valve that selectively connects the working fluid supply passage means or the working fluid discharge passage means and the connection passage means; A one-way passage means that allows only the flow of working fluid from the control valve toward the working fluid chamber, and a control means that controls the control valve, and when the supply pressure is less than the predetermined value at the start of operation. A vehicle configured to increase the vehicle height by a predetermined amount from an initial vehicle height detected by the vehicle height detection means by supplying working fluid from the control valve to the working fluid chamber via the one-way passage means. High adjustment device.