JP2506444B2 - Vehicle fluid pressure supply device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle fluid pressure supply device for an active suspension that utilizes fluid pressure such as hydraulic pressure, and particularly to a pump capable of changing the discharge amount. The present invention relates to a fluid pressure supply device including a section.

[Conventional technology]

As a conventional vehicle fluid pressure supply device, for example, a device described in Japanese Patent Application Laid-Open No. 63-251313 proposed by the present applicant is known.

One aspect of this conventional device is that a variable discharge hydraulic pump connected to a rotary drive source such as an engine and a discharge amount of pressure oil per one rotation of the hydraulic pump are set to be higher than those when the vehicle is stopped. And a discharge amount control means for increasing the discharge amount.
Among them, the hydraulic pump is composed of a plurality of pumps, and the discharge amount control means is a discharge amount control circuit that operates while receiving a vehicle speed signal, for example, indicating that the vehicle is traveling, and the discharge current control circuit uses the exciting current from the discharge amount control circuit And an electromagnetic directional valve that switches the discharge path of each pump. The discharge flow rate controlled by the electromagnetic directional control valve is supplied to the hydraulic active suspension.

[Problems to be Solved by the Invention]

However, in such a conventional vehicle fluid pressure supply device, the electromagnetic directional control valve is controlled according to the drive current (excitation current) from the discharge amount control circuit, and the vehicle-mounted battery is used as its power source. Therefore, a large current flows through the starter motor during engine cranking,
Battery terminal voltage drop occurs. As a result, it becomes difficult to maintain the switching position of the electromagnetic directional control valve, the switching of the directional control valve becomes intermittent, and chattering occurs. There was an unsolved problem of reducing durability.

On the other hand, when starting the engine,
When the terminal voltage drops or the battery is weak, we want to prioritize the start of the engine so that the power of the battery can be prioritized to be supplied to the starter motor. There is a request to keep it as small as possible.

The present invention has been made by paying attention to such unsolved problems and demands of the related art, so that the switching position of the electromagnetic directional control valve during cranking of the engine is not affected by the decrease in the terminal voltage of the battery. The first problem to be solved is to solve the problem.

Further, in the present invention, in addition to the above-mentioned first problem, it is necessary to reduce the load at the time of starting the engine as much as possible and to ensure the starting of the engine while maintaining an accurate vehicle posture when the vehicle is stopped.
This is the second issue.

[Means for solving the problem]

In order to solve the first problem, the invention according to claim (1) supplies a fluid pressure to a fluid pressure cylinder interposed between a vehicle body and wheels via a control valve, as shown in FIG. In a fluid pressure supply device, a pump unit whose discharge amount can be changed, an electromagnetic valve which changes the discharge amount of this pump unit according to an electric signal supplied thereto, and an electromagnetic valve which is operated according to the operating state of the vehicle A discharge amount control unit that supplies a signal and a cranking state detection unit that detects a cranking state of the engine are provided, and the discharge amount control unit is provided when the cranking state detection unit detects the cranking state of the engine. In addition, it includes energization stopping means for turning off the electric signal supplied to the solenoid valve.

Further, in order to solve the second problem, in the invention according to claim (2), particularly, the drive torque of the pump portion is lower when the electric signal supplied to the solenoid valve is off than when it is on. Further, the fluid pressure cylinder is set to a value capable of supplying the minimum discharge amount required when the vehicle is stopped.

[Action]

In the invention according to claim (1), when the cranking state detecting means detects the cranking state of the engine, the energization stopping means stops (turns off) the supply of the electric signal to the solenoid valve. Therefore, the solenoid valve takes an operation mode corresponding to the turning off of the electric signal, and the pump section sends the discharge amount based on the operation mode to the load side to form the line pressure. Therefore, even if a large current flows through the starter motor when the engine is started and the terminal voltage of the battery drops, the drop does not affect the operation mode of the solenoid valve. That is, even when an electromagnetic directional switching valve is used as the electromagnetic valve, it is possible to eliminate a mode in which it becomes difficult to maintain the switching position of the switching valve due to a decrease in the terminal voltage of the battery.

Particularly, in the invention described in claim (2), when the engine is in the cranking state, the solenoid valve takes an operation mode when the electric signal is off, and the discharge amount at that time is smaller than when the electric signal is on, It also corresponds to the minimum amount required by the fluid pressure cylinder. Therefore, the engine load at the time of starting the engine is reduced as much as possible, the starting thereof is made more reliable, and the proper vehicle posture when the vehicle is stopped can be maintained.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 2 to 5.

In FIG. 2, 2 is a vehicle body, 4 is a wheel, 6 is an active suspension as a load, and 8 is a hydraulic pressure supply device as a fluid pressure supply device for the active suspension 6.
Although not shown in FIG. 2, the suspension structure is the same for all four wheels.

As shown in FIG. 2, the hydraulic pressure supply device 8 determines a tank 10 for storing hydraulic oil, a pump unit 14 having a suction side connected to the tank 10 by a pipe 12 and having a variable discharge amount, and a line pressure. Relief valve 16 and 3 port 3 as solenoid valve
It has a position electromagnetic directional control valve 18 and a discharge amount control circuit 20 for controlling the electromagnetic directional control valve 18.

The pump unit 14 includes an engine 22 as a rotational drive source for the vehicle.
Is a variable discharge amount pump system connected to the output shaft 22A, and specifically includes a plunger type hydraulic pump 24 having a plurality of cylinders and check valves 26a and 26b. The hydraulic pump 24 comprises a first hydraulic pump 24A having a relatively large discharge amount per rotation by every other group in each cylinder, and a small discharge amount per rotation by the other group. The second hydraulic pump 24B is configured. The discharge flow rate characteristics with respect to the rotation speeds of the first and second hydraulic pumps 24A and 24B are as shown in FIG. 3 in this embodiment. That is, when the vehicle is stopped or traveling straight on a good road, the required flow rate is covered by the discharge amount of the second hydraulic pump 24B, and the first hydraulic pump 24A or the first hydraulic pump 24A
The total amount of discharge from the first and second hydraulic pumps 24A and 24B is provided to meet each of the pumps 24A and 24A to satisfy these conditions.
24B maximum flow rate A, B is set.

Supply side pipelines 28a and 28b are connected to the discharge ports of the first and second hydraulic pumps 24A and 24B, respectively, and these pipelines 28a and 28b join via check valves 26a and 26b, and supply side pipelines are connected. As it becomes the path 30, it branches at the upstream side of the check valves 26a, 26b and reaches the first and second input ports A ₁ , A ₂ of the electromagnetic directional control valve 18, respectively. The tank side port T of the switching valve 18 communicates with the tank 10 via a pipe 32.

The electromagnetic directional control valve 18 is a spring offset type having double solenoids 18a, 18b.
It can be switched according to ON / OFF of the exciting currents CS ₁ and CS ₂ as electric signals individually supplied to the discharge amount control circuit 20. That is, when both the currents CS ₁ and CS ₂ are both “off”, the port (A ₁ -T) is placed in a communicating position (neutral position), the current CS ₁ is “on”, and CS ₂ is “off”. , The port is in the first switching position that allows communication only between ports “A ₂ -T”, and conversely the current CS ₁ is “off”, CS ₂
Is on, it assumes a second switching position that shuts off each port A ₁ , A ₂ , T. Therefore, when the electromagnetic directional control valve 18 reaches the second switching position, the maximum flow rate from the pump unit 14 is
The total discharge amount of the second hydraulic pumps 24A, 24B is output to the load side, and the operation mode III is set. Similarly, when the first switching position is reached, the second hydraulic pump 24B becomes no-load operation,
The discharge amount of the first hydraulic pump 24A having a medium flow rate is output, and the operation mode II is set. Further, at the neutral position, on the contrary, the first hydraulic pump 24A is in no-load operation, the discharge amount of the second hydraulic pump 24B, which is the minimum flow rate, is output, and the operating mode I is set.

The discharge amount control circuit 20 is equipped with a microcomputer in this embodiment. The discharge amount control circuit 20 includes stroke sensors 36FL, 36FR provided on the front left wheel side and the front right wheel side.
Signals x _L and x _R according to the distances (stroke positions) between the vehicle body and the wheels, and a signal N according to the engine speed (that is, pump speed) output from the engine speed sensor 38.
And the starter signal ST from the key switch 40, respectively, and the calculation shown in FIG.
Every 20 msec). Then, the discharge amount control circuit 20 determines to turn on / off the exciting currents CS ₁ and CS ₂ for switching control at regular time intervals T (for example, 2 sec: T> Δt). Here, the stroke sensors 36FL and 36FR are composed of, for example, potentiometers, and the engine speed sensor 38 is structured to magnetically detect the speed of the output shaft of the transmission, for example.

The key switch 40 is interposed between the vehicle-mounted battery 42 and each load, and is rotated from the off (OFF) position to the ignition (IGN) position, whereby the ignition coil and the discharge amount control circuit 20, the attitude control Power circuit 62,
Further, by setting the starter (START) position, the drive current is supplied to the starter motor 44 while the power supply is maintained, and in order to notify such a state, the starter signal ST having the logical value "1" is discharged. Output to the control circuit 20.

The microcomputer of the discharge amount control circuit 20 captures the flow rate characteristic of FIG. 3 as the estimated consumed flow rate Q _{A with} respect to the pump rotation speed N, and stores this in advance in the memory in the form of a storage table. If this storage table is used, the mode I, I depending on which flow rate curve a ₁ , a ₂ , a ₃ includes the coordinate point uniquely determined by both coordinate axes N, Q _A with the maximum efficiency.
I or III can be selected.

Further, the relief valve 16 is provided at a position on the discharge side of the hydraulic pressure supply device 8 and a supply side pipeline 30 from the pump portion 14 to the active suspension 6 and the suspension 6 to the tank.
It is connected to the return pipe line 48 leading to 10.

The active suspension 6 has a supply line and a return line.
Check valves 52, operated check valves 54, accumulators 56 for accumulating pressure, pressure control valves 58 as control valves, hydraulic cylinders 60 as accumulators,
An attitude control circuit 62 that controls the pressure control valve 58 and an acceleration sensor 64 that detects the behavior of the vehicle are included.

Explaining this in detail, the discharge side of the pump section 14 is connected to a supply side pipeline 30, and this pipeline 30 reaches a supply port of a pressure control valve 58 via a check valve 52 and an accumulator 56. It is in communication. The return port of the pressure control valve 58 is connected to the return side pipe line 48, and this pipe line 48 reaches the tank 10 via the operation check valve 54. The operate check valve 54 is composed of a pilot operated check valve in which the line pressure on the downstream side of the check valve 52 is the pilot pressure P _{P. In} this embodiment, the pilot pressure P _P > P _N (P _N is pressure control When the neutral pressure of the valve is operating: See Fig. 4), the pipe 48 is communicated in the unchecked state (the valve is open), and when P _P ≤ P _N , the pipe 48 is in the checked state (the valve is closed). Cut off.

The pressure control valve 58 is an electromagnetic spool including a valve housing, a spool slidably arranged in an insertion hole in the valve housing, and a proportional solenoid that presses one end of the spool according to a command value I. A well-known structure that is composed of a valve and the control pressure of the output port is fed back to the other end of the spool (for example, refer to the above-mentioned JP-A-63-251313).
It has become. This pressure control valve 58 responds to the command value I supplied from the attitude control circuit 62 to its proportional solenoid,
The control pressure c output from the output port can be controlled as shown in FIG. That is, when the command value I is zero, a predetermined offset pressure P _O is output, and when the command value I increases in the positive or negative direction, it changes with a predetermined proportional gain K ₁ and saturates at the maximum line pressure P _MAX . . On the other hand, when the pressure P _{C of the} output port fluctuates due to the vibration input in the sprung resonance region from the road surface side while the urging forces at both ends of the spool are in balance, the spool moves and hydraulic oil is supplied to the hydraulic pressure supply device 8. To distribute between
It is possible to absorb such pressure fluctuations.

The hydraulic cylinder 60 has a cylinder tube 60a attached to the vehicle body 2 and a piston rod 60b attached to the wheel 4, and a pressure chamber L is separated in the cylinder tube 60 by a piston 60c. The pressure chamber L communicates with the output port of the pressure control valve 58 via the pipe 66. In FIG. 2, 68 is a coil spring for supporting the static load of the vehicle body 2,
Reference numeral 70 is an accumulator for absorbing vibration that communicates with the pressure chamber L via the throttle 72.

In the present embodiment, the acceleration sensor 64 accelerates the lateral, front-rear and vertical accelerations acting on the vehicle body 2 and outputs an electric signal G corresponding to the state quantities to the attitude control circuit 62. The attitude control circuit 62 is configured by mounting a microcomputer, and performs a calculation such as multiplying an input acceleration detection signal G by a predetermined gain to suppress a roll and pitch of the vehicle body and a command value I for damping vertical vibration. To calculate
The pressure control valve 58 is supplied.

 Next, the operation of the above embodiment will be described.

First, the processing of FIG. 5 executed by the discharge amount control circuit 20 will be described. When the key switch 40 is turned to the ignition terminal and the discharge amount control circuit 20 is powered on to start the control circuit 20, the processing of a predetermined main program is started, and a minute time Δ is set under the control of this main program.
The process of FIG. 5 is executed as a timer interrupt every t (for example, 20 msec) (in the figure, the counter c is initialized to zero by the main program at the time of startup).

The CPU of the discharge amount control circuit 20 reads the starter signal ST from the key switch 40 in the step of FIG. 5 and determines in step whether or not the key switch 40 is in the starter position.

In the step, the starter signal ST has a logical value "0"
However, when it is determined that the starter motor 44 is not activated although the ignition switch is turned on, the processes of steps 1 to 4 are subsequently performed.

In other words, stroke sensor 36FL, 36FR
The detection signals x _L and x _R are input and subjected to filtering processing in steps. In this fortering processing, it is assumed that the low frequency side, for example, a change amount of 0.5 Hz or less is a value when adjusting the vehicle height, and the high frequency side, for example, a change amount of 6 Hz or more is a stroke change on the unsprung resonance frequency side. It will be cut off as.

Then in steps, Based on the equation (subscripts L and R are omitted), the integrated value of the stroke change, that is, the total stroke amount "1 / T
∫ || dt ”corresponding cylinder flow rate Q _L , Q _R
Are individually requested. T is an integration time (for example, 2 seconds),
It is determined in consideration of the steering frequency, the switching characteristic of the pump unit 14, and the like. K is a gain based on the pressure receiving area of the hydraulic cylinder 60.

By the way, the discharge flow rate from the pump unit 14 is actually required only when the stroke changes to the extension side and the hydraulic oil flows into the hydraulic cylinder 60, and the stroke changes to the contraction side and the hydraulic oil changes. There is no need to supply hydraulic oil when is discharged. Focusing on the actual stroke fluctuation between the vehicle body 2 and the wheels 4, in most cases, the vibration appears symmetrically on the extension side and the contraction side. Therefore, when the above calculation is applied to such a stroke variation curve x,
Since the area in both positive and negative directions with 0 as the boundary can be calculated, after all, the step procedure is to perform an approximate calculation of the consumed flow rate with respect to the total stroke change of the four wheels including the inflow of the hydraulic oil on the rear wheel side. There is.

Next, in a step, Q _A = Q _L + Q _R + Q _O (2) is calculated for the preset value Q _O corresponding to the internal leak amount of the four-wheel pressure control valve 58, and the estimated consumption of the entire system is calculated. Obtain the flow rate Q _A and move to the step.

In the step, the counter c is incremented for each interrupt process, and in the step, a predetermined time T (= Δt · A)
It is determined whether or not the integer A corresponding to is reached. If the count value of the counter c has not reached A in this determination,
Return to the main program and keep the currently commanded pump mode.

On the other hand, if "YES" in the step, the counter c = 0 is set in the step, and then the process proceeds to the step. The detection signal N of the engine speed sensor 38 is read, the value is stored, and the process proceeds to the step.

In this step, the minimum discharge flow rate operation mode to which the coordinate point uniquely determined by the estimated consumption flow rate Q _A and the pump rotation speed N belongs is set by referring to the storage table corresponding to FIG. In other words, in mode I, the exciting currents CS ₁ , C
Both S ₂ are turned off, and if mode II, CS ₁ = on, CS ₂ = off, and if mode III, CS ₁ = off, CS ₂ = on. Then, in step, the exciting currents CS ₁ and CS ₂ are output based on the set ON / OFF.

On the other hand, while repeating the timer interrupt process, when it is determined to be “YES” in the above step, the process moves to the step and the energization of the electromagnetic directional control valve 18 is forcibly stopped, so that the exciting currents CS ₁ , CS Both ₂ are commanded off (ie mode I).

 Next, the overall operation will be described.

It is assumed that the vehicle is currently stopped with the engine 22 not driven. In this stopped state, the hydraulic pump 24 is also not rotating, so the discharge amount is zero and the operating check valve 54 is closed. That is, the load side is contained in the neutral pressure P _N by the check valve 52 and the operate check valve 54, and the predetermined vehicle posture is maintained.

In this state, by rotating the key switch 40 to the ignition position, the ignition switch is turned on, power is supplied to the ignition coil and the control circuits 20 and 62, and the discharge amount control and the attitude control are activated.

Then, when the key switch 40 is rotated to the starter position, power is supplied from the key switch 40 to the starter motor 44, the motor 44 is driven, and the engine 22 enters the cranking state. At this time, the processing of FIG. 5 is executed through steps ,, so that the exciting currents CS ₁ , CS ₂
Are both turned off (zero), and the pump unit 14 is in the same operation as the operation mode I. As a result, as described above, since the electromagnetic directional control valve 18 has its switching position in the neutral position, only the second hydraulic pump 24B supplies the line pressure, which covers the small flow rate consumed when the vehicle is stopped.

As described above, in the cranking state when the engine is started, the electromagnetic directional control valve 18 controls the discharge amount by the non-excited switching position, so that the terminal voltage of the battery 42 is changed by driving the starter motor 44. Even if it decreases, it will not be affected. That is, chattering does not occur in the switching valve 18 unlike in the conventional case. For this reason,
The generation of abnormal noise can be eliminated, the occupant does not feel uneasy, and the durability of the switching valve 18 can be improved.

Further, by setting the switching position of the switching valve 18 to the non-energized position during cranking, the electric power of the battery 40 can be preferentially supplied to the starter motor 44, whereby the engine can be started more reliably. This is particularly advantageous when the battery 42 is weak and the terminal voltage is low, or in cold regions.

On the other hand, in this embodiment, when the engine is started, the hydraulic pump
Since the discharge amount of 24, that is, the drive torque is set to the minimum, the load of the engine 22 is small, and the power consumption of the battery 40 is small. From this point as well, the starting of the engine is easier and more reliable.

When the engine 22 is started as described above, the discharge amount from the pump unit 14 also increases accordingly, and the line pressure P _L rises to the maximum ground P _MAX . During this rise, when the pilot pressure P _P becomes P _P > P _N , the operating check valve 54
Is opened, the return-side pipeline 48 is brought into communication, and the vehicle body posture can be actively controlled.

Therefore, if the vehicle travels straight at a constant speed on a smooth road without unevenness, vibration input from the road surface and stroke fluctuation between the vehicle body 2 and the wheels 4 hardly occur. Therefore, the process in FIG. 5 is performed through steps (or) and the estimated consumption flow rate Q _A ≈Q _O. Then, in step, for example, the point m ₁ is read on the map (FIG. 3) according to the pump rotation speed N at that time, and the mode I is selected, so that the exciting currents CS ₁ and CS ₂ = OFF. Become. As a result, as described above, the electromagnetic directional control valve 18 sets its switching position to the neutral position, so that only the second hydraulic pump 24B is in the operating state in which the line pressure is supplied. That is, when it is estimated that the flow rate consumed by the hydraulic cylinder 60 is low, as in the case where the vehicle runs straight on a good road even in the traveling state, the pump unit 14
Since the discharge amount of is reduced, horsepower consumption is reduced and fuel consumption is improved.

Further, assuming that the running state becomes a swelling road where low-frequency unevenness continues, stroke signals X _L and X _R having frequencies and amplitudes corresponding to this running are output to the stroke sensors 36FL and 36FR.
Obtained from As a result, in the processing of FIG. 5, the estimated consumption flow rate Q _A also increases, so that the point m ₂ , for example, is read on the map (FIG. 3) and the mode II is selected. Therefore, the exciting current CS ₁ = ON, CS ₂ = OFF, and the electromagnetic directional control valve 18 takes the first switching position. Therefore, the first hydraulic pump
A larger discharge amount of 24A is supplied to the line.

On the other hand, in the state where there is a low-frequency vibration input of the sprung resonance frequency from the road surface side, the spool of the pressure control valve 58 first moves to move the hydraulic oil between the cylinder 60 and the hydraulic pressure supply device 8. Distribute and generate damping force. But,
When it reaches a state where it cannot be damped by this damping action,
The acceleration sensor 64 of the vehicle body 2 detects the vertical acceleration, and the attitude control circuit 62 outputs a command value I for generating a damping force to the pressure control valve 58.
To control the operating pressure of the hydraulic cylinder 60. Although the consumed flow rate in this control state is a relatively large value, the discharge rate of the pump unit 14 is also increased to cope with this, so that insufficient flow rate is prevented and an effective damping effect is obtained.

Further, for example, when a point m ₃ is read on the map (FIG. 3) in the processing of FIG. 5 by traveling on a rough road, mode III is set. That is, the exciting current CS ₁ = OFF, CS ₂ = ON, and the electromagnetic directional control valve 18 takes the second switching position, so that the first and second hydraulic pumps 24A,
The total discharge amount of 24B is supplied to the line, which covers a large consumption flow rate.

Further, when the vehicle body 2 tries to generate a roll or pitch due to turning traveling or acceleration / deceleration traveling, the attitude control circuit 62 outputs command values I, ..., I based on lateral and longitudinal accelerations to suppress the attitude change. At this time, the pump unit 14 is set to an appropriate mode corresponding to the consumption flow rate Q _A according to the stroke variation.

In this embodiment, the key switch 40, the step shown in FIG.
Constitutes a cranking state detecting means, and the processes of steps 1 to 5 in the same figure correspond to the discharge amount control section, of which the step corresponds to the energization stopping means.

Here, in the above embodiment, the sensor signals from the lateral acceleration sensor and the longitudinal acceleration sensor are also input to the discharge amount control circuit 20, and when the lateral acceleration or the longitudinal acceleration exceeds a predetermined value, the stroke signal is changed. It is also possible to perform an operation in which the estimated consumption flow rate is further increased by a predetermined value, and to make a mode determination according to the operation result. Similarly, the sensor signal of the vehicle speed sensor may be input, and the mode may be set according to whether the vehicle is in a stopped state or a traveling state.

In the above embodiment, when the engine 22 is cranked, the electromagnetic directional control valve 18 is set to the non-energized switching position (neutral position), and the drive torque of the hydraulic pump 24 is set to the minimum allowable range. Although the value, that is, the operation in the mode I is used, the following examples may be provided as examples corresponding to the invention described in claim (1). In other words, the switching position of the electromagnetic directional control valve 18 is exchanged, and when the engine 22 is cranked, the electromagnetic directional control valve 18 is simply set to the non-energized (CS ₁ and CS ₂ ) switching position. It may be operated in Mode II. This makes it possible to prevent chattering of the switching valve 18 in the same manner as described above, and
Power supply to the starter motor 44 during cranking can be made sufficient.

Further, the pump section in the present invention does not necessarily have to have the structure of three-stage switching by the above-mentioned three modes, and may have a simplified configuration by two-stage switching, or may be equipped with a continuously variable flow rate switching pump. It is also possible to precisely control the total discharge amount. Alternatively, the stroke sensor may be individually provided for each of the four wheels, and the flow rate consumed by the cylinders of the four wheels may be individually calculated. Further, the control circuit 20, 6 in the embodiment
It is also possible to configure the entire 2 by a single microcomputer that performs the same calculation.

On the other hand, although the case where the working fluid is the working oil has been described in the above embodiment, the present invention is not necessarily limited to this, and any fluid having a low compression rate can be applied.

〔The invention's effect〕

As described above, in the invention according to claim (1), the electric signal to the solenoid valve is positively turned off (non-energized) when the engine is cranked, and the operation mode adopted by the solenoid valve when the electric signal is turned off. Since the discharge amount of the pump unit is controlled based on the above, there is an advantage that even if the terminal voltage of the battery is lowered by driving the starter motor, the operation of the solenoid valve is not adversely affected. In other words, even if this solenoid valve is, for example, an electromagnetic directional control valve, chattering does not occur as in the conventional case, so that an abnormal noise is generated and an occupant feels uneasy and durability is reduced. Absent. On the other hand, at the time of cranking, the starter motor can be preferentially supplied with electric power as much as it is not necessary to supply electric power to the solenoid valve, so that the engine can be started reliably.

Further, in the invention described in claim (2), since the drive torque of the pump portion during cranking is a value corresponding to the minimum flow rate that can ensure an appropriate vehicle posture when the vehicle is stopped, the above-described effect is obtained. It can be enjoyed, the load at the time of starting the engine can be further reduced, the reliable starting of the engine can be promoted, and the fuel consumption can be improved.

[Brief description of drawings]

FIG. 1 is a diagram corresponding to the scope of claims of the present invention, and FIG.
FIG. 4 is a schematic configuration diagram showing an embodiment of the present invention, FIG. 3 is a graph showing a discharge amount characteristic of a hydraulic pump, FIG. 4 is a graph showing an output pressure characteristic of a pressure control valve, and FIG. 5 is a discharge amount. It is a flow chart which shows processing in a control circuit. In the figure, 2 is a vehicle body, 4 is wheels, 6 is an active suspension, 8 is a hydraulic pressure supply device (fluid pressure supply device), 14 is a pump section, 18 is an electromagnetic directional control valve (electromagnetic valve), and 20 is a discharge amount control. Circuit, 22 engine, 40 key switch, 42 battery,
44 is a starter motor, 58 is a pressure control valve (control valve), and 60 is a hydraulic cylinder (fluid pressure cylinder).

Claims (2)

(57) [Claims] 1. A fluid pressure supply device for supplying a fluid pressure to a fluid pressure cylinder interposed between a vehicle body and a wheel via a control valve, and a pump portion having a variable discharge amount and a discharge amount of this pump portion. A solenoid valve that changes the electric signal according to the supplied electric signal, a discharge amount control unit that supplies the electric signal to the electromagnetic valve according to the operating state of the vehicle, and a cranking state detection that detects the cranking state of the engine. The discharge amount control unit includes an energization stopping unit that turns off an electric signal supplied to the solenoid valve when the cranking state detection unit detects the cranking state of the engine. A vehicle fluid pressure supply device. 2. The drive torque of the pump unit is lower when the electric signal supplied to the solenoid valve is off than when it is on, and can supply the minimum discharge amount required when the fluid pressure cylinder is stopped. The vehicle fluid pressure supply device according to claim 1, wherein the fluid pressure supply device is set to a value.