JPH02267018A - Pressure controlling device for suspension - Google Patents

Abstract

PURPOSE:To stabilize pressure adjusting action of an operating spool in a pressure controlling device for restricting attitude change by change of operating condition by connecting a passage member with work space for a plunger of a solenoid, and flowing fluid in the work space into a liquid return tube. CONSTITUTION:A work space of a plunger 97 of solenoids 96-99 is connected with a passage member 98c connected to a liquid return tube 11, so that the work action side of a spool 90, the liquid return tube 11, and the work space of the plunger 97 are connected with each other. The pressure on the work space side of the spool 90 is a little higher than the pressure on the side of the liquid return tube 11 by the effects of a partial drain emission under high pressure, and thus fluid in operation for a pressure controlling device flows from the work space of the spool 90 to the return tube 11. Stay of fluid in the work space can therefore be prevented, and the pressure adjusting action of the spool is stabilized.

Description

DETAILED DESCRIPTION OF THE INVENTION OBJECTS OF THE INVENTION (Field of Industrial Application) The present invention relates to pressure control of vehicle suspensions, and in particular:
The present invention relates to a device for controlling suspension pressure so as to suppress changes in vehicle body posture due to changes in vehicle driving conditions, etc.

(Prior art) For example, Japanese Utility Model Publication No. 62-38402 discloses that the steering angular velocity is detected by a sensor, and when the vehicle speed reaches a set value, the damping force or spring constant of the suspension is determined. Suspension control has been proposed to increase the

Also, for example, Japanese Patent Application Laid-Open No. 63-106133;
A suspension pressure control method has been proposed in which the turning pattern of the vehicle is determined from the steering angle and the steering angular velocity, the gain is changed accordingly, and the suspension pressure is determined in accordance with the gain and the lateral acceleration of the vehicle. ing.

In these suspension pressure controls, a required pressure is applied to the suspension by a pressure control valve. For example, the pressure control valve receives pressure at one end from a line pressure port communicating with a high-pressure pipe, a low-pressure boat communicating with a fluid return pipe to the reservoir, and an output port 2 that applies pressure to the suspension. The spool is driven in the direction of lowering the flow rate between the line pressure boat and the output port and increasing the flow rate between the low pressure port and the output port, and the spool is driven in the direction of lowering the flow rate between the line pressure port and the output port and increasing the flow rate between the line pressure port and the output port. It has a solenoid that is driven in a direction that lowers the degree of flow between the port and the output port (for example, Japanese Patent Laid-Open No. 63-1999)
106133), by controlling the energizing current of the solenoid, the balancing force of the spool is determined, a pressure corresponding to this is created at the output port, and the pressure of this output port is applied to the suspension.

Various sensors measure vehicle height, longitudinal acceleration, and lateral acceleration of the vehicle.

When steering, etc. is detected, the electrical control means detects or predicts a change in the vehicle body posture, calculates a suspension pressure correction amount to offset (prevent) the vehicle body change, and adjusts the suspension pressure by this correction amount. The solenoid current of the pressure control valve is adjusted to compensate for the
When there is roll, the pressure on the suspension that contracts is increased (linear correction) and the pressure on the suspension that expands is lowered (extension correction) to suppress changes (deterioration) in the vehicle's posture. Alternatively, the target vehicle height can be set according to the vehicle speed or by the driver's input operation, the suspension pressure correction amount can be calculated to make the detected vehicle height the target vehicle height, and the suspension pressure can be adjusted accordingly. The solenoid current of the pressure control valve is adjusted to correct the amount.

(Problem to be Solved by the Invention) The plunger space of the solenoid of the pressure control valve applies force to the spool in the direction of increasing the degree of communication between the line pressure port and the output port and decreasing the degree of communication between the low pressure port and the output port. It communicates with the spool working space through the working space of the actuator for giving, so it is filled with suspension supply and drainage fluid. When the air dissolved in the suspension supply/discharge fluid becomes bubbles in the plunger space, since the air is compressible, it expands and contracts when the plunger moves forward and backward, giving a spring action to the plunger. This spring action causes unintended vibrations and excessive forward and backward movement of the plunger.
This makes the spool output pressure adjustment operation unstable. If the solenoid is equipped with an air bleeder, the air bleeder can be opened to bleed air immediately after device assembly or during inspection, but this must be done manually. If air is generated in the plunger operating space due to bubble formation of air dissolved in the fluid or entry of air from an air bleeder during operation of the device, this cannot be eliminated. Air must be vented when the equipment is stopped.

An object of the present invention is to prevent air from remaining in the plunger operating space of a pressure control valve and to stabilize the pressure regulating operation of the spool of the pressure control valve.

[Structure of the invention]

(Means for Achieving the Object) The pressure control device of the present invention includes a reservoir (2) connected to a high pressure pipe (6) for supplying pressure fluid to a suspension (100 fr) that expands and contracts in accordance with the supplied pressure. A pressure source (1) that supplies suctioned fluid at high pressure; and a line pressure port h (82) communicating with the high pressure pipe (6).

Low pressure port (85) communicating with fluid return line (11) to reservoir (2), output port (84) that provides pressure to suspension (100fr), output port (84)
pressure is received at one end, and this pressure causes the line pressure port (
A spool (90) and a spool (9o) that are driven in a direction that lowers the degree of flow between the output port (82) and the output port (84) and increases the degree of flow between the low pressure port (85) and the output port (84).
To increase the flow rate between the line pressure port (82) and the output port (84), the low pressure bow 1- (85) and the output port (84) are increased.
An operator (9
5a, 95b).

Solenoids (96-99) each having a plunger (97) that drives the actuator (95a, 95b) in the direction, and a fluid return pipe (96-99) coupled to the plunger operating space of the solenoid (96-99). 11) Pressure control valve (80fr) including flow passage part (98c) connected to
; Note that symbols in parentheses indicate corresponding elements in the embodiments shown in the drawings and described later.

(Function) When the solenoid (96 to 99) is energized at a certain ffl flow value, the line pressure port (8
2) and the output port (84) to increase the flow rate between the low pressure photovoltaic (
85) and the direction (
A force in the pressure increasing direction) acts on the spool (9o). That is, a force acts on the spool (9o) in the direction of increasing the output pressure of the outlet port (82). On the other hand, the spool (9
0), the pressure of the output port (82) lowers the flow rate between the line pressure port (82) and the output port (84), and the low pressure port (85) and the output port (84) acts in the direction of increasing the degree of permeability (in the direction of lowering the pressure). Therefore, the sprue (90) is at a position where the force exerted by the solenoids (96-99) and the force exerted by the pressure of the output capacitor (84) are balanced. When the current value of the solenoids (96 to 99) is increased, the output pressure of the output port (871) is increased, and when it is decreased, the output pressure of the output port (871) is decreased by 1ζ.

Even when the solenoid current is kept constant, if the suspension pressure increases due to a wheel bump, this will act on the spool (9o) through the output port (87I), causing the spool (90) to move in the direction of decreasing pressure. Move and select the output port (
84) pressure decreases. That is, the suspension pressure is partially controlled by the pressure control valve 1 (80fr) through the fluid return pipe (11).
) will be overtaken. When the suspension pressure decreases when the car 11 falls, this acts on the spool (90) via the output port (84), causing the spool (9o) to move in the pressure increasing direction and increasing the pressure at the output port (84). goes up. In other words, high pressure is applied to the suspension (by the pressure control valve (80fr)
loofr). In this way, the output port (
84) pressure (suspension pressure) is applied to the pressure control valve (80
The sprue (9
0) operates, and the propagation of the upper and lower vibrations of the wheels to the vehicle body is buffered.

In the plunger operating space of the solenoids (96 to 99),
Fluid enters from the operating space side of the spool (90) through the operating space of the actuators (95a, 95b), and the fluid is transferred to the plunger operating space through the fluid return pipe (11) =
Since the flow path member (98c) connected to 7 is connected, the plunger operation space communicates with the operation space side of the spool (90) and the fluid return pipe (1). Viewed from the plunger operating space, the operating space side of the spool (90) and the fluid return line side have roughly the same low pressure, but more specifically, the operating space side of the spool (90) has a higher pressure. Slightly high due to partial drain discharge.

Hence pressure control! During the operation of 1, the fluid flows through the spool (
The fluid flows through the plunger working space in a direction from the working space side of 90) toward the fluid return conduit (11). Air bubbled from the fluid in the plunger operating space while the pressure control device is stopped, or air generated during operation, is caused by the fluid flow when the pressure control device is in operation, and the solenoid 1 - energizing current value The movement of the plunger due to the change in the axle, the similar reciprocating movement of the actuators (95a, 95b) due to the reciprocating movement of the spool (90) in response to the upward and downward vibrations of the axle, and the reciprocating movement of the plunger brought about by this, the fluid is At the same time, it flows through the flow path member (98c) to the return pipe (]]), reaches the reservoir (2), and exits there to the atmosphere.

Therefore, even if air remains in the plunger operating space while the pressure control device is stopped, it is automatically discharged from the plunger operating space when the pressure control device is activated.

As mentioned above, since the air in the plunger operating space automatically exits to the return pipe (11) during the operation of the pressure control device,
In the first operation of the pressure control device, substantially no air remains in the plunger operating space, and the spring action of the air does not act on the plunger, so the pressure regulating operation of the spool (90) is stabilized. There is no need for manual air removal work.

Other objects and features of the present invention will become apparent from the following description of embodiments with reference to the drawings.

(Example) FIG. 1 shows an outline of the mechanism of a vehicle body support device. The hydraulic pump 1 is a radial pump, which is disposed in the engine room, is driven to rotate by the vehicle engine (not shown), sucks oil from the reservoir 2, and pumps it under high pressure at a predetermined rotational speed. Oil is discharged to ports 1 to 3 at a predetermined flow rate.

High pressure port 3 of radial pump for suspension pressure supply
A pulsation absorbing accumulator 4° main check valve 50 and a relief valve 60m are connected to the high pressure port 3 through the main check valve 50.
high pressure oil is supplied to the high pressure supply pipe 8.

The main check valve 50 prevents oil from flowing back from the high pressure supply pipe 8 to the high pressure port 3 when the pressure in the high pressure boat 3 is lower than the pressure in the high pressure supply pipe 8.

The relief valve 60m connects the high pressure port 3 to the reservoir return pipe 11, which is one of the return oil passages to the reservoir 2, when the pressure in the high pressure port 3 exceeds a predetermined pressure.
The pressure in the high pressure port 3 is maintained at a substantially constant pressure.

The high pressure supply pipe 8 has a front wheel suspension of 100f L.

a front wheel high pressure supply pipe 6 for supplying high pressure to the 100fr;
A rear wheel high pressure supply pipe 9 for supplying high pressure to the rear axle suspensions 100r L and 100rr communicates with each other, the front wheel high pressure supply pipe 6 is connected to an accumulator 7 (for the front wheels), and the rear wheel high pressure supply pipe 9 is connected to an accumulator 7 (for front wheels). 10 (for the rear axle) is in communication.

A pressure control valve 80fr is connected to the front wheel high pressure supply pipe 6 via an oil filter.
However, the pressure in the front wheel high-pressure supply pipe 6 (hereinafter referred to as front axis line pressure) is regulated (pressured down) to the required pressure (pressure crab suspension support pressure corresponding to the energizing current value of the electric coil), and the cut valve 70fr and the relief are activated. Give to valve 60fr.

When the pressure of the front wheel high pressure supply pipe 6 (front wheel side line pressure) is less than a predetermined low pressure, the cut valve 70fr closes the pressure control valve 80fr.
(to the suspension engine) and the hollow piston rod 102fr of the shock absorber 101fr of the suspension 100fr.
) to the outside pressure control valve 80fr, and while the front wheel side line pressure is above a predetermined low pressure, the pressure control valve 80f
The output pressure (suspension support pressure) of r is directly supplied to the piston rod 102fr.

Relief valve 60fr is shock absorber 101
Limit the internal pressure of fr to below the upper limit. That is, when the pressure (suspension support pressure) at the output port 84 of the pressure control valve 80fr exceeds a predetermined high pressure, the output port 84 is made to flow through the reservoir return pipe 11, and the pressure control valve 80fr
maintains the pressure at the output port substantially below a predetermined high pressure.

The relief valve 60fr is further provided with a pressure control valve 80 when the internal pressure of the shock absorber 101fr rises impulsively due to an upward impact on the front right axle from the road surface.
When the internal pressure of the shock absorber 101fr rises impulsively, the internal pressure of the shock absorber 101fr is transferred to the piston rod 100f.
r and the reservoir return pipe 1 through the cut valve.
Release to 1.

Suspension] 0Ofr is roughly a shock absorber of 101fr and a suspension coil spring of 1.19f.
r, and corresponds to the pressure supplied into the shock absorber 101fr via the output port 84 of the pressure control valve 80fr and the piston rod 102fr (pressure regulated by the pressure control valve 80fr: suspension support pressure). Support the vehicle body at height (relative to the front right axle).

The support pressure given to the shock absorber 101fr is
Detected by pressure sensor 13fr, pressure sensor] -3f
r generates an analog signal indicative of the detected support pressure.

A vehicle height sensor 15fr is attached to the vehicle body near the suspension ball 100fr, and a link connected to the rotor of the wheel sensor 15fr is connected to the front right wheel. The vehicle height sensor 15fr generates an electric signal (digital data) indicating the vehicle height of the front right wheel (the height of the vehicle body relative to the wheel).
occurs.

Pressure control valve 80fL and cut valve 70 similar to the above
fL, a relief valve 60fL, a vehicle height sensor 15fL, and a pressure sensor 13f are similarly installed and assigned to the front left axle suspension 100fL,
A pressure control valve 80fL is connected to the front wheel high-pressure supply pipe 6 to apply the required pressure (support pressure) to the piston rod 102f of the shock absorber 101fL of the suspension 100fL.
Give to L.

Pressure control valve 80rr, cut valve 7 similar to the above
0rr, relief valve 60rr, vehicle height sensor 15
Similarly, a pressure control valve 80rr is connected to the rear wheel high pressure supply pipe 9 to maintain the required pressure (support pressure). The suspension 100rr
Shock absorber] 0] rr screws 1 to 2]
, 02rr.

Furthermore, pressure control valves 80r+, -, ka I~ similar to the above
Valve 70rL, relief valve 6orL, vehicle height sensor], 5r and pressure sensor 1.3+7L are similarly,
It is assigned to the suspension engine 3 and 100r L on the front left side of the car, and is connected to the pressure control valve 80r and the rear wheel high pressure supply pipe 9 to apply the required pressure (support pressure) to the suspension + OOr L shock absorber. ]Dlr
L piston rod In this example, the engine is installed on the front shaft side,
Along with this, the hydraulic pump 1 is moved to the front wheel side (engine room).
equipped with hydraulic pump 1 and rear wheel suspension]
,0Orr, ],OOr The piping length from the hydraulic pump] to the front axle suspension is 100fr.

]00f Longer than the piping length to L. Therefore, the pressure drop due to the piping is large on the rear wheel side, and if oil leaks or the like occurs in the piping, the pressure drop on the rear wheel side is greatest. Therefore, a pressure sensor 3rm for detecting line pressure is connected to the rear wheel high pressure supply pipe 9.

On the other hand, the pressure in the reservoir return pipe 11 is lowest at the end on the reservoir 2 side, and the pressure tends to increase as the distance from the reservoir 2 increases. I am trying to detect it with .

A bypass valve] 20 is connected to the rear wheel high-pressure supply pipe 9. This bypass valve 120 regulates the pressure of the high-pressure supply pipe 8 to a pressure corresponding to the current value of the electric coil (obtains the required line pressure). Also, the ignition switch is opened (engine stops: pump 1 stops)
When the line pressure is reduced to the atmospheric pressure of the reservoir 2 through the reservoir return pipe 11, the cut valves 70fr and 70f are
L.

70rr and 70rL are turned off to prevent pressure loss in the shock absorber), and lighten the load when restarting the engine (pump 1).

FIG. 2 shows an enlarged longitudinal section of the suspension], 0Ofr. A screw 103 fixed to the piston rod 102fr of the shock absorber]O]fr is connected to the inner cylinder 10.
4 is roughly divided into two sections: an upper chamber 105 and a lower chamber 106.

Suspension support pressure (hydraulic pressure) is supplied to the piston rod 102fr from the output port of the cut pulp 70fr, and this pressure is applied to the side port 1 of the screw 1-rod 102fr.
07, it joins the upper chamber 105 in the inner cylinder 104, and further joins the royal chamber 106 through the upper and lower through holes 108 of the screw 103. This pressure and screw 1 to screw F102
A support pressure proportional to the product of the cross-sectional area of fr (the square of the rod radius Xπ) is applied to the piston rod], 02f'r.

Inside@1 (the lower chamber 106 of J4 communicates with the upper space of the damping valve device 109] 10. The upper space of the damping valve device 109 is divided into a lower chamber 112 and an upper chamber] 13 by a piston 111. The oil in the upper space 110 flows into the royal chamber 112 through the damping valve device 109, but the upper chamber 113 is filled with high pressure gas.

When the screw I and rod 102fr try to relatively rapidly enter the lower part of the inner cylinder 1071 due to the upward movement of the front right wheel, the internal pressure of the inner cylinder 104 increases rapidly, and similarly the upper space 1]0 The pressure is about to suddenly become higher than the pressure in the lower chamber 112. At this time, the oil flows from the empty space 110 through the check valve of the damping valve device 109 that allows oil to flow from the empty space 110 to the lower chamber 112 at a predetermined pressure difference or higher, but prevents the oil from flowing back in the opposite direction. flows into the lower chamber 112, thereby causing the screws 1-1.1. l rises and fl is added from the wheels
It buffers the propagation of impact (in one direction) to the piston rod 102fr. That is, the propagation of the axle shock (excessive force) to the vehicle body is buffered.

When the piston rod [02fr] attempts to come out above the inner cylinder 104 due to the sudden fall of the front right wheel, the internal pressure of the inner cylinder 104 suddenly decreases and the upper space 1
10 is about to suddenly become lower than the pressure in the lower chamber 112. At this time, the damping valve device 109 allows the oil to flow from the lower chamber 2 to the upper space 10 at a predetermined pressure difference or higher, but prevents the oil from flowing in the opposite direction. It flows from the lower chamber 112 to the upper space 110, which causes the piston] 11 to descend, thereby buffering the propagation of the impact (downward) applied from the axle to the piston rod l02fr. That is,
The propagation of axle shock (downward movement) to the vehicle body is buffered.

In addition, shock absorber 101 is used to raise the vehicle height, etc.
As the pressure applied to fr increases, the lower chamber 11
The pressure at 2 increases, the screw 111 rises by 1, and the piston 111 reaches a position corresponding to the vehicle body load.

Piston rod 102 against inner cylinder 104, such as when parked
When there is no relative vertical movement of fr, the seal between the inner cylinder 104 and the piston rod 102fr allows the inner cylinder 10
4, there is virtually no oil leakage into the outer cylinder 114.

However, in order to reduce the vertical movement load on the piston rod 102fr, the seal is designed to have sealing characteristics that cause a slight oil leak when the piston rod 102fr moves up and down. The oil leaking into the outer cylinder 114 is returned to the reservoir 2 through the outer cylinder 114, through the drain 14fr (Fig. 1) which is open to the atmosphere, and through the drain return pipe 12 (Fig. 1') which is a second return pipe. . Reservoir 2 has a level sensor 28
(Fig. 1), and when the oil level in the reservoir 2 is below the lower limit, the level sensor 28 generates a signal (oil shortage signal) indicating this.

Other suspensions] 00f L, 1oorr and 100rL structures are also similar to the above-mentioned suspensions] 00f
The structure is substantially similar to that of r.

FIG. 3 shows an enlarged longitudinal section of the pressure control valve 80fr.

A spool storage hole is bored in the center of the sleeve 81, and a line pressure port 8 is provided on the inner surface of the spool storage hole.
A ring-shaped groove 83 through which the low-pressure port 85 communicates and a ring-shaped groove 86 through which the low-pressure port 85 communicates are formed. An output port 84 is opened between these ring-shaped grooves 83 and 86. The spool 90 inserted into the spool storage hole has a ring-shaped groove 91 having a width corresponding to the distance between the right edge of the groove 83 and the left edge of the groove 86 in the middle of its side circumferential surface. A valve housing hole is formed in the left end of the spool 90, and this valve housing hole communicates with the groove 91. The valve housing hole has
A valve body 93 pushed by a compression coil spring 92 is inserted.

This valve body 93 has a through orifice at its center, and the space of the groove 91 (output port 84) communicates with the space in which the valve body 93 and the compression coil spring 92 are accommodated. Therefore, the spool 90 receives, at its left end, the pressure of the output port 84 (pressure regulated, the pressure on the suspension 100: Er), thereby receiving a force that drives it to the right. In addition, the output port 84
When the pressure of Mi? increases impulsively, the valve body 93 moves to the left against the pushing force of the compression coil spring 92, and the right end of the valve body 93 Mi? Since it creates an IR space,
When the output port 84 suddenly rises, this sudden rise in pressure is not immediately applied to the left end face of the spool 90.
The valve body 93 has the effect of preventing the spool 90 from moving to the right in response to an impulsive pressure rise at the output port 84. Conversely, it has the effect of buffering the leftward movement of the spool 90 against an impactful pressure drop at the output port 84.

The pressure of the target pressure space 88 communicating with the high pressure port 87 via the orifice 88f is applied to the right end surface of the spool 90, and due to this pressure, the spool 90 receives a force that drives it to the left. Line pressure is supplied to the high pressure port 87, but the target pressure space 88 communicates with the low pressure port 89 through the communication port 94, and the communication opening degree of the communication port 94 is determined by
determined by the needle valve 95a. When the needle valve 95a closes the flow port 94, the pressure in the target pressure space 88 communicating with the high pressure boat 87 via the orifice 88f becomes the pressure (line pressure) of the high pressure boat 87, and the spool 90 is driven to the left. As a result, the groove 91 of the spool 90 communicates with the groove 83 (line pressure port 82), the pressure in the groove 91 (output port 84) increases, this is transmitted to the left side of the valve body 93, and the pressure of the spool 90 is increased. Apply right driving force to the left end. When the needle valve 95a fully opens the flow port 94, the pressure in the target pressure space 88 is narrowed by the orifice 88f, and is significantly lower than the pressure (line pressure) in the high pressure boat 87, causing the spool 90 to move to the right. As a result, the groove 91 of the spool 90 communicates with the groove 86 (low pressure port 85), the pressure in the groove 91 (output port 84) decreases, this is transmitted to the left of the valve body 93, and the spool 90 The right driving force at the left end decreases. In this way, the spool 90 is at a position where the pressure in the target pressure space 80 and the pressure in the output port 84 are balanced. That is, a pressure substantially proportional to the pressure in the target pressure space 88 appears at the output port 811C.

The pressure in the target pressure space 88 is determined by the position of the needle valve 95a and is substantially inversely proportional to the distance between the needle valve 95+1 and the flow CI9/I. r4] A pressure appears that is substantially inversely proportional to the distance 5a. The needle valve 95a is pushed to the left (in the pressure increasing direction) by a rod F95b that passes through a fixed core 96 of magnetic material.

The right end of the fixed core 96 is in the shape of a truncated cone, and the end face of the magnetic plunger 97 in the shape of a conical hole with a bottom is opposed to this right end face. A rod 95b that pushes the needle valve 95a is fixed to this plunger 97.

The fixed core 9G and the plunger 97 are connected to an electric coil 99
It is entering the inside of the bobbin that is wound.

When the electric coil 99 is energized, the fixed core 96 - magnetic yoke 98z1 - magnetic end plate 98b - plunger 97 -
Magnetic flux flows through the loop of the fixed core 96 and the plunger 97
is attracted by the fixed core 96 and moves to the left, and the needle valve 95
a is driven to the left by the rod 95b and approaches the flow path 94 (the distance becomes shorter). By the way, the left end of the needle valve 95a receives the pressure of the target pressure space 88 as the right driving force, and the right end of the needle valve 95a is the return pipe pressure through the drain passage part 98c, so the two-point valve 95a receives the target pressure. Due to the pressure in the space 88, the needle valve 95a receives a right driving force corresponding to the pressure value (this corresponds to the position of the needle valve 95a), and as a result, the needle valve 95a receives the current value of the electric coil 99 with respect to the communication port 94. The distance is substantially inversely proportional to . In order to make the relationship between current value and distance linear, one of the fixed core and plunger is shaped like a truncated cone, and the other is shaped like a corresponding conical hole with a bottom. There is.

As a result of the above, the electric coil 99 is installed in the output capo I~84.
A pressure appears that is substantially proportional to the current value.

This pressure control valve 80 f r outputs a pressure proportional to the applied current to the output port 84 when the current is within a predetermined range.

By changing the value of the current flowing through the electric coil 99, the vehicle height can be adjusted high or low.

The runs of the needle valve 95a are provided with a spiral so that the fluid resistance during its reciprocating motion is neither excessively large nor excessively small, that is, the movement of the needle valve 95a is smooth and does not move too sensitively. il, 5
! 95c, and these spiral grooves 95c communicate the space on the front end (left end) side and the space on the rear end (right end) side of the knee 1 hell valve 95a.

The mouth 951) integrated with the plunger 97 has a groove 95 on its side circumferential surface extending from the tip to the rear end along the longitudinal axis.
d is cut, and these full 95d are the fixed core 95
2 which passes through and communicates with the operating space of the plunger 97.
, Therefore, in the common theory [the operation space at the left end of the low-pressure boat 89 side space (needle valve 95J) heard in 194], there is a spiral groove 95c and a straight line F+! ) The operating space of the plunger 97 is communicated through 95d. On the other hand, the operating space of the plunger 97 communicates with the return pipe 11 via the drain passage part 98c.

The low pressure port 89 also communicates with the return pipe 11, but since fluid with a pressure higher than that of the return pipe 11 flows out from the communication port 94, the knee 1 help? The pressure in the space around the left end of 95C is slightly higher than the pressure in the return pipe 11. Therefore, some of the fluid around the needle valve 95c is absorbed into the spiral groove 95c of the needle valve 95a and the rod 9.
It flows gently into the operating space of the plunger 97 through the linear groove 95d of the groove 5b, and from there flows into the return pipe 1 through the rain flow member 98c. This results in
No air remains in the operating space of the plunger 97. Air remaining in the working space while the pump 1 is stopped automatically flows out to the return pipe 11 when the pump 1 is driven to output high pressure.

FIG. 4 shows an enlarged longitudinal section of the cut valve 10fr.

The valve housing hole drilled in the valve base 71 has a line pressure port 72. Pressure adjustment capo-1 to 73. The exhaust/111 port 74 and the output port door 5 are in communication. A ring-shaped first
The pressure regulating input capo 1-73 and the output port door 5 are separated by cylindrical guides 77a, 77b and 77c. The oil drain bow 1-74 communicates with a ring-shaped groove on the outer periphery of the second guide 77c, and returns oil leaked to the outer periphery of the second guides 77a, 77b, and 77c to the return pipe 11.

A spool 78 pushed leftward by a compression coil spring 79 passes through the first and second guides 76, 77a to 77c, and line pressure is applied to the left end surface of the spool 78.

The guide hole of the central protrusion of the second guide 77c, into which the left end of the spool 78 has entered, communicates with the return pipe 11 through the ring-shaped groove on the outer periphery of the second guide 77c and the oil drain port 74. When the line pressure is less than a predetermined low pressure, the spool 78 is driven to the leftmost side by the repulsive force of the compression coil spring 79, as shown in FIG. is the second guide 7
This is blocked by fully closing the inner opening of 7a. When the line pressure exceeds a predetermined low pressure, this pressure causes the spool 79 to resist the repulsive force of the compression coil spring 79.
begins to be driven to the right, and the spool 79 is positioned at the rightmost position (fully opened) at a pressure higher than the predetermined low pressure. That is, when the spool 78 moves to the right from the inner opening of the second guide 77a, the pressure regulating input port door 3 communicates with the output port 75, and the line pressure (line pressure port 72) rises to a predetermined low pressure, the cut valve 70fr is activated. When the pressure regulation input port door 3 (pressure regulation output of the pressure control valve 80fr) and the output port door 5 (shock absorber 101fr) start flowing, and the line pressure (boat 72) further increases, the pressure regulation input port door 3
(pressure regulation output of pressure control valve 80fr) and output port door 5 (
The shock absorber 101fr) is fully opened. When the line pressure decreases, the opposite is true, and when the line pressure falls below a predetermined low pressure, the output port door 5 (shock absorber 101fr) is completely cut off from the pressure regulation input port door 3 (pressure regulation output of the pressure control valve 80fr). Ru.

FIG. 5 shows an enlarged longitudinal section of the relief valve 60fr. Insert capo 1-62 into the valve housing hole of the valve base 61.
and low pressure bow 1-63 is open. A cylindrical first guide 64 and a second guide 67 are inserted into the valve storage hole, and the input port 2 communicates with the inner space of the first guide 64 through the filter 65. First guide 64
A valve body 66 having an orifice in the center is inserted into the valve body 66, and this valve body 66 is connected to a compression coil spring 66a.
is pushed to the left. The space in which the valve body 66 and the compression coil spring 66a are accommodated in the first guide 64 communicates with the input port 2 through the orifice of the valve body 66, and also communicates with the input port 2 through the opening of the spring seat 66b. It communicates with the inner space of 67. The conical valve body 68 is pushed to the left by the repulsive force of the compression coil spring 69, closing the opening of the spring seat 66b.

When the pressure (control pressure) of the input port 2 is less than a predetermined high pressure, the pressure in the coil spring 66a housing space, which communicates with the input port 2 through the orifice of the valve body 66, is
Since it is relatively lower than the repulsive force of the compression coil spring 69, the valve body 68 closes the center opening of the valve seat 66b as shown in FIG. It is cut off from the inner space of the second guide 67, which communicates through the hole 67a. That is, the output port 2 is cut off from the low pressure port 63.

When the pressure (control pressure) of the input port 2 rises to a predetermined high pressure, this pressure passes through the orifice of the valve body 66 and reaches the valve seat 6.
When the valve body 68 starts to be driven to the right by this pressure applied to the central opening of the valve 6b, and the pressure in the input port 2 further increases, the valve body 68 is driven to the rightmost side. That is, the pressure of the input port 2 is released to the low pressure port 63, and the control pressure is suppressed to a predetermined high pressure level or less.

Note that when high pressure is applied to the input port 2, the valve body 6G is driven to the right, and the input port 2 is moved to the first guide 64.
It communicates with the valve storage space of the base body 61 through the side port 64a and the low pressure port 63, and because this flow path area is large, a sudden pressure rise (pressure shock) in the output port 2 can occur!
4M'm will be done.

FIG. 6 shows an enlarged longitudinal section of the main check valve 50. An input port 52 and an output port 53 communicate with a valve housing hole formed in the valve base 51. A cylindrical valve seat 54 with a bottom is housed in the valve housing hole, and a ball valve 57 pushed by a compression coil spring 56 closes a communication port 55 of the valve seat 54. When the pressure is higher than the pressure at the output port 53, the ball valve 57
is pushed to the right by the pressure of the input port 52 to open the communication port 55. That is, oil flows from the input port 52 toward the output port 53. However, when the pressure at the output port 53 is higher than the pressure at the input port 52, the ball valve 57 conducts the flow and closes the port 1, so that oil does not flow from the output port I-53 toward the input ports 1 to 52. .

FIG. 7 shows an enlarged longitudinal section of the bypass valve 120.

The six capos 1-121 that communicate with the high-pressure pipe line 9 communicate with the inner space (spool operating space) of the first guy 1; A tab 124a is stored.

This valve body] 24a has a communication port 1.2/Ic in the center of the left end surface.
and through this communication port 124C, the input capo-h12
+ communicates with the inner space of the first guide 123. The inner space communicates with the low pressure port 1.22 which communicates with the return pipe 1 through the communication port 122b.
The degree of flow of the low-pressure side opening of 2b is defined by the two-dollar valve 125 facing the low-pressure side opening 1''.

Needle valve 25 and fixed core 126 to electric coil 1.
The combination with the solenoid 29 is the same as the solenoid device shown in FIG. jut).

The force for pushing the needle valve 125 toward the flow opening] 22b is substantially proportional to the current value flowing through the electric coil 129.

The needle valve 125 is moved to the right by the fluid pressure (relief pressure) flowing from the six capos 1 to 121, through the communication port 124c, through the spool operating space, and further through the communication port 122b to the low pressure port 1.22. (retreat direction), the needle valve] 25 moves to a position where the force due to this relief pressure and the pushing force (leftward-advance direction) provided by the solenoids 026 to 129 are balanced. When the pressure of the sixth capo-1-121 increases, the force due to the relief pressure increases, the 21-dolbutt t125 retreats, and the relief flow rate through the communication port 122b increases, thereby suppressing the pressure increase in the input port 121. , input port]2] becomes below the relief pressure determined by the solenoid current. As a result, the pressure of the six capos 1-1 and 21 becomes a pressure that is substantially proportional to the current value of the electric coil 129. This bypass valve 120 sets the pressure (line pressure) of the input port 21 within a predetermined range of current and is proportional to the pressure. Furthermore, when the ignition switch is off (engine stopped: pump 1 stopped), the electric coil 129 is de-energized, causing the knee 1 to needle valves 125 to move to the rightmost position. ~121 (line pressure) is a low pressure near the return pressure.

Knee 1 hell valve when the solenoid current is limited to - within the specified range]
When the maximum pushing force is applied to 25, the needle valve 125
When reaches the limit on the retraction (rightward) side of the predetermined range, the compression coil spring 1 is
24b is compressed, the spool 124a moves in the retracting direction (rightward), and the low pressure ports 1i and 22a are connected to the input ports 1 to 1.
]2], the pressure of the inlet port h121 is connected to the low pressure port 1.
-Exit to 122a. Since the low pressure ports 1i and 22a are relatively large openings, the abnormally high pressure in the input port I.2 immediately escapes to the low pressure port h]22a. That is, the spring force of the compression coil spring 1.241) is set to a relatively strong spring force corresponding to the upper limit of the input pressure at which the needle valve 25 performs an effective relief operation within the planned energization range of the solenoid current. For example, when adjusting the relief pressure (pressure in the high-pressure pipe) from the low 8 to the high 13 by adjusting the solenoid current, if a pressure of 8 or more is applied to the input port 121, , the compression coil spring 124b is compressed and the spool 1.24a
Although the low pressure port 1.22a is moved in the retraction direction 'h' and the input port 121 is communicated with the input port 121, the compression coil spring 124b is not substantially compressed at a pressure of less than 8, and the spool 124a is not compressed as shown in FIG. As shown in FIG. 2, the low pressure port 122a is isolated from the input port I-12.

Therefore, when the pressure in the high pressure pipe 9 is within the normal pressure range, the pressure in the input port 12 is maintained at a certain pressure corresponding to the solenoid current by the relief operation of the needle valve 125, and the spool 124a does not move. When abnormally high pressure is applied to the input ports 1 to 12, the spool 12
4a moves away. As a result, the frequency of movement of the spool 24a is extremely low, and accordingly, the probability that the spool will catch foreign objects or burrs in the fluid is low, and the spool will not stick. The needle valve] 25 faces the low-pressure side opening of the communication port 122b, and there is no possibility that foreign matter or particles may become stuck between the needle valve and the needle valve 122b.

The relief valve 60m is the relief valve 60f mentioned above.
It has the same structure as r, but has a conical valve body (68:
The compression coil spring (69) that presses the input capo-1- (62) has a slightly small spring force.
) (pressure of high pressure bow 1-3), the relief valve 60fr reduces the pressure of the capo 1-62 to low pressure photo 63.
When the pressure is less than the predetermined high pressure, which is slightly lower than the pressure to be released to the output port (62), the output port (62)
). When the pressure at the input port (62) exceeds a predetermined high pressure, the valve body (68) is driven to the rightmost direction. That is, the pressure of the input port (62) is released to the low pressure port (63), and the pressure of the high pressure bows 1 to 3 is suppressed to a predetermined high pressure or less.

With the above configuration, in the vehicle body support device shown in FIG. 1, the main check valve 50 supplies oil from the high pressure port 3 to the high pressure supply pipe 8, but prevents backflow from the high pressure supply pipe 8 to the high pressure port 3. do.

The relief valve 60m suppresses the pressure in the high pressure port 3, that is, the pressure in the high pressure supply pipe 8, to a predetermined high pressure or less, and when the pressure in the high pressure port 3 rises impulsively, the pressure in the return pipe 1
1 to buffer the propagation of impactive pressure to the high-pressure supply pipe 8.

The bypass valve 120 controls the pressure of the rear wheel high pressure supply pipe 9 substantially linearly within a predetermined range, and maintains the pressure of the rear wheel high pressure V9 at a predetermined constant pressure during normal operation. This constant pressure control is performed by controlling the energizing current value of the bypass valve 120 with reference to the pressure detected by the pressure sensor 13rm. Furthermore, when there is an impactful pressure increase in the rear wheel suspension, it is released to the return pipe 11 to buffer its propagation to the high pressure supply pipe 8. Furthermore, when the ignition switch is open (engine stopped: pump 1 stopped), electricity is cut off and the flow is returned from the rear wheel high pressure supply pipe 9 to the return pipe 1, and the rear wheel high pressure supply pipe 9 (high pressure supply pipe 8 ) Release the pressure.

Pressure control valve 80fr, 1lof L, 80rr, 80
rL is an electric coil (99
) is controlled, and the required support pressure is output to the output port (84). When the impact pressure from the suspension is propagated to the output port (84), this i!
! As a result, disturbances in the pressure control spool (91) (disturbances in the output pressure) are suppressed. In other words, the required pressure is stably applied to the suspension.

Cut valve 70f r + 70f L I 70r
r + 70r L shuts off the suspension pressure control (between the output port 84 of the pressure control valve and the suspension) when the line pressure (front axle high pressure supply pipe 6, rear axle high pressure supply pipe 9) is less than a predetermined low pressure. , prevents pressure from escaping from the suspension, and fully opens the supply pressure line when the line pressure is higher than a predetermined low pressure. This automatically prevents an abnormal drop in suspension pressure when line pressure is low.

Relief valve 60fr, 60f L, 60rr, 6
0rL limits the pressure (mainly suspension pressure) of the Suspension supply pressure line (between the output photo 84 of the pressure control valve and the suspension) to below the high pressure upper limit, and prevents the pressure from rising when the wheels are pushed up or when heavy objects are loaded. When there is a shocking pressure rise in the supply pressure line (suspension) due to the injection of
It alleviates the impact and increases the durability of the hydraulic line connected to the suspension and the mechanical elements connected to it.

〔Effect of the invention〕

As described above, according to the pressure control device of the present invention, the air in the operating space of the plunger (97) of the pressure control valve (80fr) is automatically returned to the return pipe (11) during operation of the pressure control device.
During operation of the pressure control device, the plunger (9)
Since substantially no air remains in the operating space of 7) and the spring action of the air does not act on the plunger (97), the pressure regulating operation of the spool (90) is stabilized.

There is no need for manual air removal work.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a suspension pressure supply system according to an embodiment of the present invention. FIG. 2 is an enlarged longitudinal sectional view of the suspension 100fL shown in FIG. FIG. 3 is an enlarged longitudinal sectional view of the pressure control valve 80fL shown in FIG. 1. FIG. 4 is an enlarged longitudinal sectional view of the cut valve 70fL shown in FIG. 1. FIG. 5 is an enlarged longitudinal sectional view of the relief valve 60fL shown in FIG. 11 and FIG. FIG. 6 is an enlarged longitudinal sectional view of the main chatter valve 50 shown in FIG. 1. FIG. 7 is an enlarged longitudinal sectional view of the bypass valve 120 shown in FIG. 1. ]: Pump 2: Reservoir 3: High pressure ports 1 to 4: Accumulator 6; Front shaft high pressure supply pipe 7:
Accumulator 8: High pressure supply pipe 9: Back II! High pressure supply pipe 10: Accumulator 11; Reservoir return pipe 12 Nidrain return pipe 13f L
, 13fr, 13r L , 13rr, 13r+11.
]-3rl; :Pressure sensor 14f t-, ]7Ifr
, 14rL, I'lrr: l' rain of atmospheric release] 5
fL, 15.1'r,], 5rw, 15rr: JIL high sensor 1.6.3: Longitudinal acceleration sensor 1
6r: Lateral acceleration sensor 17: Microprocessor
18-Microprocessor] 9: Battery
20: Ignition switch 21: Constant voltage power supply circuit 22: Relay 2; 1: Backup power supply circuit 24 Brake lamp 25
: T((Speed synchronous pulse generator 26, two rotary encoders 27: absolute encoder 28: hot water level detection switch 291 to 293: A
/l) converters 301-30. ,: Signal processing circuit
:+11-Ronno (Sfili 32: Duticon I Laura 3:3: Coil 1-Rynobe 34:
6/Output circuit 50: Main check valve 51: Valve base 52; Human capo-1-
53: Dekazuki-1-571 = Benza 55;
Flow “I56: Compression coil spring 5
7: Ball valve 60fr, 60f L, 60rr, 60
r L: Relief valve 61; Novel valve base 62
: Inlet capo l-63: Low pressure port 64: First guide 65: Filter 66: Valve body 67: Second guide 1 to 68: Valve body 69: Compression coil spring 7]: Valve base 72 Line pressure port 73: Adjustment To press-fit capo-1 74: oil drain port, 75
: Output port 76: 1st guy 1-77: Guide
78 Nispool 79: Compression coil spring 80fr, 8C1f L, 80rr, 80r L:
Pressure control valve 81 Ni sleeve 82 Ni line Pressure port 83: Groove 84: Output port 85: Low pressure port
86: Groove 87: High pressure boat 88: Target pressure space
88f Niorifice 89: Low pressure port 90 Varnish spool 91: Groove 92; Compression coil spring
93: Valve body 94: Flow port 95a:
Two dollar valve 95b:Lotsu l<95c: f! Circular groove 95d: Groove 96: Fixed core 97;
Plunger 9B+i: Yoke 98b; End plate 98c Nidrain flow member 99: Electric coil 102fr, 102fL, ], 02rr, 10
2rji screw I-ring t'103: Piston 1
04: Inner cylinder 105: Upper chamber 06: Lower chamber
107: Side entrance 108: J1 bottom penetration [
1] 09: Valve damping valve device 110: Upper space 11
1: Piss 1~n] 12: Lower chamber 113: Upper chamber
1. ]l: Outer cylinder 1.20: Bypass valve
] ] 21: Input port 1 to 122; Low pressure port h 1.22a: Low pressure port h 1.22b, +
24c: communication port 123: first guide], 24a:
Valve body 124b: Compression coil spring 12
5: Needle valve〕29: Electric coil

Claims (1)

[Scope of Claims] A pressure source that supplies fluid sucked from a reservoir at high pressure to a high-pressure pipeline for supplying pressure fluid to a suspension that expands and contracts in accordance with the supplied pressure; and a pressure source that communicates with the high-pressure pipeline. a line pressure port, a low pressure port that communicates with a fluid return conduit to the reservoir, an output port that applies pressure to the suspension, one end of which receives the pressure of the output port and allows communication between the line pressure port and the output port. A spool that is driven in a direction that lowers the degree of communication between the low pressure port and the output port, and increases the degree of communication between the line pressure port and the output port, and increases the degree of communication between the low pressure port and the output port. a solenoid having an actuator for applying a force in a direction that lowers the pressure; a solenoid having a plunger for driving the actuator in the direction; and a flow coupled to a plunger working space of the solenoid and connecting the plunger working space to a fluid return conduit. A pressure control device for a suspension, comprising: a pressure control valve including a passage member;