JPH02204117A - Suspension pressure controller - Google Patents

Abstract

PURPOSE:To prevent instability of suspension pressure control by closing a cut valve device to shut off the connection between a pressure control valve and a suspension when the pressure in a high pressure pipe passage drops below the pressure at which the pushing force of a spring member of the cut valve device balances with the pressure in the high pressure pipe passage. CONSTITUTION:Front and rear high pressure supply pipes 6, 9 connected to the height pressure port 3 side of a hydraulic pump 2 driven by an engine are provided with cut valves 70 (70fl-70rr) and pressure control valves 80 (80fl-80rr) for controlling hydraulic pressure supplied to suspensions 100 (100fl-100rr) provided for respective pair of wheels. The cut valves 70 are provided so that the connection between an output port 84 of a pressure control valve 80 communicating to the suspension 100 and hollow piston rods 102fl-102rr of shock absorbers 101fl-101rr is shut off when the pressure in the high pressure supply pipes 6, 9 is below a specified value, and that the output pressure of the pressure control valve 80 as it is can be supplied when the line pressure is equal to or higher than the specified value.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to pressure control of vehicle suspensions.

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 and the like.

(Prior art) For example, Japanese Utility Model Publication No. 62-38402 discloses suspension pressure control that detects the steering angular velocity with a sensor and increases the suspension pressure when the vehicle speed is above a set value and the steering angular velocity is above the set value. is proposed.

Furthermore, for example, Japanese Patent Application Laid-Open No. 63-106133 discloses that the turning pattern of the vehicle is determined from the steering angle and the steering angular velocity, the gain is changed accordingly, and the gain is changed correspondingly to the turning pattern of the vehicle based on the steering angle and the steering angular velocity. Suspension pressure control during turning has been proposed to determine the suspension pressure.

In these suspension pressure controls, a required pressure is applied to the suspension by a pressure control valve. For example, the pressure control valve controls the pressure of a line pressure port communicating with a high pressure pipe, a low pressure port communicating with a fluid return pipe (return pipe) to the reservoir, an output port that applies pressure to the suspension, and a target pressure space 2 output port. The pressure received at one end drives the flow in the direction of lowering the degree of communication between the line pressure port and the output port and increasing the degree of flow between the low pressure port and the output port. A spool that is driven by pressure in a direction that increases the degree of flow between the line pressure port and the output port and lowers the degree of flow between the low pressure port and the output port, and defines the degree of flow between the target pressure space and the return pipe. The device has a valve body that moves the valve body, and a solenoid that drives the valve body in the direction of increasing or decreasing the degree of flow (for example, Japanese Patent Application Laid-Open No. 106133/1983). The position is determined, a corresponding required pressure is created in the target pressure space, and a pressure substantially equal to the pressure in the target pressure space is applied to the output port (suspension).

(Problem W1 to be solved by the invention) If the pressure in the high-pressure pipeline falls below a predetermined pressure due to an increase in consumption flow, etc., the pressure in the target pressure space will drop and the spool will move between the line pressure port and the output port. The pressure at the output port is reduced by lowering the flow rate and increasing the flow rate between the low pressure port and the output port. Therefore, the pressure at the output port (suspension pressure) decreases as the pressure in the high-pressure pipeline decreases.The maximum control pressure at the output port is limited by the pressure in the high-pressure pipeline, and when the pressure drops below a predetermined pressure, The pressure that can be controlled by the control valve decreases, making it impossible to maintain the required suspension pressure. As a result, the vehicle height sinks, making it impossible to control the attitude of the vehicle body. It is necessary to prevent such a drop in suspension pressure.

The above-mentioned suspension pressure drop is caused by a pilot pressure space that receives the pressure of the high-pressure pipe between the output port of the pressure control valve and the suspension, an input port that receives the pressure regulated by the pressure control valve, and an output port that communicates with the suspension. ,
a valve body that is driven by the pressure of the pilot pressure space to allow flow to flow between the input port and the output port; and a spring member that drives the valve body in a direction that blocks the input port and the output port. This can be achieved by inserting a cut valve device with a According to this, when the pressure in the high-pressure pipeline decreases to less than the pressure that balances the pushing force of the spring member of the cut valve device, the cut valve device automatically shuts off between the pressure control valve and the suspension, and This automatically prevents pressure from being released to the pressure control valve.

When using such a cut valve device, the direction of the reciprocating movement of the valve body is determined by a guide member, but the guide hole that guides the valve body in a reciprocating manner is designed so as not to obstruct the predetermined movement of the valve body. Connect to return line. However, since the pressure control valve controls the flow rate between the line pressure port, low pressure port, and output port to obtain the required pressure at the output port, The fluid in the high pressure pipe flows out through the pressure control valve (line pressure port/output port communication pressure regulating space/low pressure port path). This flow rate increases as the pressure fluctuation at the output port of the pressure control valve becomes larger and faster. This is because the reciprocating motion of the spool becomes large and frequent.6 The suspension pressure oscillates between high and low due to the sudden rise and fall of the wheel, and this vibration pressure The spool is applied to the output port of the pressure control valve and reciprocates so as to suppress pressure fluctuations due to this oscillating pressure, so in such a case, a large amount of outflow from the high pressure pipe to the return pipe through the pressure control valve increases. Therefore, pressure fluctuations occur in the return line.

When pressure fluctuations in the return line propagate to the guide hole of the cut valve device that reciprocally guides the valve body.

Due to this pressure fluctuation, the force balance of the valve body is disrupted, and a force is applied to the valve body that drives the opening between the output port of the pressure control valve and the suspension pressure supply line in the direction of closing (or in the direction of opening). This fluctuates in response to pressure fluctuations, and the degree of flow through the opening fluctuates.5 This fluctuation causes pressure fluctuations at the output port of the pressure control valve, disturbs the pressure control operation of the pressure control valve, and causes suspension pressure Increases control instability.

The primary purpose of the present invention is to prevent a drop in the pressure control valve output pressure due to a drop in pressure in a high-pressure pipe line, that is, a drop in suspension pressure. The second purpose is to prevent pressure fluctuations at the control valve output port.

[Structure of the invention]

(Means for Solving the Problems) The pressure control device of the present invention has a reservoir (2) connected to a high pressure pipe (6) for supplying pressure fluid to a suspension (100 fr) that expands and contracts according to the supplied pressure. Pressure source (1) that supplies suctioned fluid at high pressure; line pressure port (82) communicating with high pressure pipe (6), low pressure port communicating with first pipe line (II) that returns fluid to reservoir (2). (85
), an output port (84) that provides pressure to the suspensicon (100fr), and a target pressure space (88) that communicates with the line pressure port (82) via an orifice (88f).
.

The pressure of the output port (84) is received at one end, and this pressure lowers the degree of flow between the line pressure port (82) and the output port (84), thereby increasing the degree of flow between the low pressure port (85) and the output port (84). Driven in the direction of increasing the target pressure space (88)
pressure is received at the other end, and this pressure causes the line pressure port (
The spool (90) is driven in the direction of increasing the flow rate between the low pressure port (85) and the output port (84) and lowering the flow rate between the low pressure port (85) and the output port (84), and supplies fluid to the reservoir (2). Target pressure space (88) for returning low pressure pipe (11)
) and a valve body (95) that defines the degree of flow of the valve body (95).
5) A pressure control valve device comprising electrically energized driving means (96, 97, 98a, 98b) for driving the valve in the direction of increasing or decreasing the permeability. (80fr); High pressure pipe (6
), the pilot pressure space (72p) receives the pressure of the pressure control valve (80fr), and the input capo (72p) receives the pressure regulated by the pressure control valve (80fr).
(73), an output port (75) that communicates with the suspension (100fr), and a valve body that is driven by the pressure of the pilot pressure space (72ρ) to allow flow between the input port (73) and the output port (75). 78), first conduit (1
A guide member (77c1) having a guide hole (77(:2)) that communicates with a fluid path (74, 12) for air release that is separate from 1) and guides a valve body (78); ) is provided with a spring member (79) that drives the input port (73) and the output port (75) in a direction to cut off the connection between the input port (73) and the output port (75). This is attached to the corresponding element of the embodiment.

(Function) The pressure control valve device (80fr) moves the valve body (
95) to create a corresponding required pressure in the target pressure space (88), and a pressure substantially equal to the pressure in the target pressure space (88) is applied to the suspension (84) via the output port (84). 100 fr).

As a result, the pressure in the high pressure pipe (6) decreases.

The cut valve device (70fr) is the pressure control valve (80fr)
Output port (84) and suspension (100fr)
Since the gap is shut off between the suspension and the pressure control valve (80fr), pressure is automatically prevented from leaking from the suspension (100fr) to the pressure control valve (80fr).

A guide hole (77c2) that guides the cut valve device [(70fr), the valve body 78 for performing the above-mentioned shutoff]
but.

A fluid path (74,
12), the pressure fluctuation in the first pipe line (11) causes the valve body (78) to generate an erroneous driving force that opens and closes the opening (77ao) between the output port of the pressure control valve and the suspension pressure supply line. will no longer act, and the pressure control operation of the pressure control valve will no longer be disturbed.

As described above, according to the present invention, a decrease in the output pressure of the pressure control valve (80fr) due to a pressure decrease in the high pressure pipe (6) is prevented, and a decrease in the output pressure of the pressure control valve (80fr) due to pressure fluctuations in the return pipe (11) is prevented. Pressure fluctuations at the output port (84) are prevented.

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

(Example) Fig. 1 shows an outline of the mechanism of a vehicle body support device. A hydraulic pump 1 is a radial pump, and is disposed in an engine room and is rotationally driven by an on-vehicle engine (not shown). The pump sucks oil from the reservoir 2 and discharges the oil at a predetermined flow rate to the high pressure port 3 at a rotation speed of a predetermined speed or higher.

High pressure port 3 of radial pump for suspension pressure supply
A pulsation absorbing accumulator 4° main check valve 50 and 60 relief valves 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 port 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.

Front wheel high pressure IQ pipe 6 for supplying high pressure to 100fr.

A rear wheel high pressure supply pipe 9 for supplying high pressure to the rear axle suspensions 100rL and 100rr communicates with each other.The front wheel high pressure supply pipe 6 is connected to an accumulator 7 (for front wheels), and the rear axle high pressure supply pipe 9 is connected to an accumulator 10. (for rear wheels) are communicating.

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 wheel line pressure) is regulated (pressurized) 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 valve are activated. Give 60fr.

When the pressure of the front wheel high pressure supply pipe 6 (front axle side line pressure) is less than a predetermined low pressure, the cut valve 70fr closes the pressure control valve 80f.
r (to the suspension) and the hollow piston rod 102fr of the shock absorber 101fr of the suspension 100fr.
) to the pressure control valve 80fr, and while the front shaft side line pressure is above a predetermined low pressure, the pressure control valve 80
The output pressure (suspension support pressure) of fr 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 80f
The pressure at the output port of r is maintained substantially below a predetermined high pressure. The relief valve 60fr was further affected by the impact of pushing up the front right wheel from the road surface, and the shock absorber was 1.01.
When the internal pressure of the shock absorber 101fr rises impulsively, this cushions the propagation of this impact to the pressure control valve 80fr, and when the internal pressure of the shock absorber 101fr impulsively rises, the piston rod 100fr and is discharged into the reservoir return pipe 11 via a cut valve.

Suspension 100fr roughly consists of shock absorber 101fr and suspension coil spring 119fr.
Output port 8 of pressure control valve 80fr
4 and the pressure supplied into the shock absorber 101fr via the piston rod 102fr (pressure control valve 8
The vehicle body is supported at a height (relative to the front right axle) corresponding to the pressure crab suspension support pressure regulated at 0fr.

The support pressure given to the shock absorber 101fr is
It is detected by the pressure sensor 13fr, and the pressure sensor 13fr generates an analog signal indicating the detected support pressure.

A vehicle height sensor 15fr is attached to the vehicle body near the suspension 1oOfr, and a link connected to the rotor of the axle sensor 15fr is connected to the front right axle. The vehicle height sensor 15fr generates an electric signal (digital data) indicating the vehicle height of the front right wheel (height of the vehicle body relative to the axle).
occurs.

Pressure control valve 80fL and cut valve 70 similar to the above
f L, relief valve 60fL, vehicle height sensor 15f
Similarly, a pressure control valve 80fL is connected to the front wheel high pressure supply pipe 6 to maintain the required pressure (support pressure). The suspension 100f
It is applied to the piston rod 1Q2fL of the engine gear absorber 101f of L.

Pressure control valve 80rr, cut valve 7 similar to the above
0rr r Relief valve 60rr, vehicle height sensor l
Similarly, a pressure sensor 13rr and a pressure sensor 13rr are assigned and equipped to the rear right wheel suspension 100rr.

A pressure control valve 80rr is connected to the rear wheel high pressure supply pipe 9 to apply the required pressure (support pressure) to the piston rod 102rr of the shock absorber 1o1rr of the suspension 100rr.
4 Furthermore, the pressure control valve gOrLt cut valve 70rw+ relief valve 60rLl vehicle height sensor 15rL and pressure sensor 13rL similar to the above,
The pressure control valve 80rL is assigned to the front left axle suspension 100rL, and the pressure control valve 80rL is connected to the rear wheel high pressure supply pipe 9.
is connected to apply a required pressure (supporting pressure) to the piston rod 102rL of the shock absorber 1o1rL of the suspension 1oOrL.

In this example, the engine is installed on the front wheel side.
Along with this, the hydraulic pump 1 is moved to the front wheel side (engine room).
It is installed in the hydraulic pump 1 to the rear axle suspension 1.
Piping lengths up to 00rr and 100rL.

Hydraulic pump 1 to front wheel suspension 100fr.

Longer than the piping length to Roof L 6 Therefore, the pressure drop due to the piping is large on the rear wheel side, and if an oil leak occurs in the piping, the pressure drop on the rear axle side is the largest, so the rear wheel high pressure A pressure sensor 13rm for detecting line pressure is connected to the 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 tends to increase as the distance from the reservoir 2 increases. Therefore, the pressure in the reservoir return pipe 11 is also detected on the rear wheel side by the pressure sensor 13rt. I try to do that.

A bypass valve 120 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). 1 stop)
When this occurs, the line pressure is reduced to substantially zero (atmospheric pressure in the reservoir 2 through the reservoir return pipe 11).
L +70rr, 70r L is turned off to prevent pressure loss in the shock absorber), and lighten the load when restarting the engine (pump 1).

FIG. 2 shows the piston rod 1 of the shock absorber 101fr, showing an enlarged longitudinal section of the suspension 100fr.
A piston 103 fixed to the 02fr roughly divides the inside of the inner cylinder 104 into 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 valve 70fr, and this pressure is applied to the side port 10 of the piston rod 102fr.
7, joins the upper chamber lO5 in the inner cylinder 104, and further connects the royal chamber 10 through the upper and lower through-holes 108 of the piston 103.
Join 6. A support pressure proportional to the product of this pressure and the cross-sectional area of the piston rod 102fr (rod radius squared x π) is applied to the piston rod 102fr.

The lower chamber 106 of the inner cylinder 104 communicates with the upper space 110 of the damping valve system [109]. The space above the damping valve device 109 is
It is divided into a lower chamber 112 and an upper chamber 113 by a piston 111, and oil in an upper space 110 flows through the lower chamber 112 through a damping valve device 109, while high pressure gas is sealed in the upper chamber 113.

When the piston rod 102fr tries to relatively rapidly enter the lower part of the inner cylinder 104 due to the thrust upward movement of the front right wheel, the internal pressure of the inner cylinder 104 increases rapidly, and the pressure in the upper space 110 also decreases to the lower chamber. The pressure will suddenly become higher than that of H2. At this time, the oil flows into the upper space 112 through the check valve of the damping valve device 109 that allows the oil to flow from the upper space 110 to the lower chamber 112 at a predetermined pressure difference or higher, but blocks the flow in the opposite direction. This causes the piston 111 to rise and the impact from the five wheels to be applied! ! It buffers the (upward) propagation to the piston rod 102fr. In other words, the axle impact I on the vehicle body! (ball thrusting) propagation is buffered.

When the piston rod 102fr relatively tries to come out above the inner cylinder 104 due to the sudden fall of the front right axle, 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 oil is allowed to flow into the lower chamber through the check valve of the damping valve system [109, which allows oil to flow from the lower chamber 112 to the upper space 110 at a predetermined pressure difference or higher, but blocks the flow in the opposite direction. 112 and flows into the upper space 110.

As a result, the piston 111 descends and the impact is applied from the wheels! ! It buffers the (downward) propagation to the piston rod 102fr. In other words, axle impact (including falling) on the vehicle body
propagation is buffered.

In addition, shock absorber / <10
As the pressure applied to 1fr increases.

The pressure in the lower chamber 112 increases, causing the piston 111 to rise.

The piston 111 is at a position corresponding to the vehicle body load.

The piston rod against the inner cylinder 104 while parked! 02
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 such that only a small amount of oil leaks when the piston rod 102fr moves up and down. It is said to have the sealing properties of The oil leaking into the outer cylinder 114 passes through the outer cylinder 114 and through the drain 14fr (Fig. 1) which is released to the atmosphere.

Drain return pipe 12 (first return pipe), which is the second return pipe
(Fig.) and is returned to the reservoir 2. The reservoir 2 is equipped with 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.

The structure of the other suspensions 100f L, 100rr and 100r L is also the same as the above-mentioned suspension! 00
The structure is substantially similar to that of fr.

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 storage 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 the pressure of the output port 84 (regulated pressure on the suspension 100fr) at its left end, and thereby receives a force that drives it to the right. Note that when the pressure of the output port 84 becomes shockingly high, the valve body 93 moves to the left against the pushing force of the compression coil spring 92, creating a buffer space at the right end of the valve body 93. , when the output port 84 suddenly rises, this shocking rising pressure is not immediately applied to the left end face of the spool 90, and the valve body 93 responds to the shocking rise in pressure at the output port 84. It has the effect of buffering the rightward movement of the spool 90, and vice versa.

This has the effect of buffering the leftward movement of the spool 90 against an impactful pressure drop at the output port 84.

The right end surface of the spool 90 receives the pressure of the target pressure space 88 that communicates with the high pressure port 87 via the orifice 88f, 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 is supplied to the low pressure port 89 through the flow path 94.
The needle valve 95 defines the flow opening of this flow path 94 . When the needle valve 95 closes the flow path 94, the high pressure port 87 is opened via the orifice lll8f.
The pressure in the target pressure space 88 communicated with the high pressure port 87 becomes the pressure (line pressure), and the spool 90 is driven to the left, whereby the groove 91 of the spool 90 communicates with the groove 83 (line pressure port 82). and groove 91 (output port 84)
The pressure increases, and this is transmitted to the left side of the valve body 93, giving a rightward driving force to the left end of the spool 90. needle valve 95
When the channel 94 is fully opened, the pressure in the target pressure space 88 is throttled by the orifice 18f, so the high pressure port 8
The pressure (line pressure) at 7 is significantly lower than that at spool 9.
0 moves 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 side of the valve body 93, and the spool 90
The right driving force at the left end of is reduced. In this way.

The spool 90 connects the pressure in the target pressure space 80 and the output port 8.
This is the position where the pressure of 4 is balanced. That is, a pressure substantially proportional to the pressure in the target pressure space 88 is applied to the output port 8.
Appears in 4.

The pressure in the target pressure space 88 is determined by the position of the needle valve 95 and is substantially inversely proportional to the distance of the needle valve 95 with respect to the flow path 94. An inversely proportional pressure appears.

The needle valve 95 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 needle valve 95 is fixed to this plunger 97. The fixed core 96 and plunger 97 are
It enters inside the bobbin around which the electric coil 99 is wound.

When the electric coil 99 is energized, magnetic flux flows through the loop of the fixed core 96 - magnetic yoke 98a - magnetic end plate 98b - plunger 97 - fixed core 96, and the plunger 97 is attracted to the fixed core 96 and moves to the left. However, when the needle valve 95 approaches the flow path 94 (the distance becomes shorter),
The left end of the needle valve 95 receives the pressure of the target pressure space 88 as the right driving force, and the right end of the needle valve 95 is at atmospheric pressure through the low pressure port 98c open to the atmosphere. As a result, the needle valve 95 receives a right driving force corresponding to the pressure value (which corresponds to the position of the needle valve 95), and as a result, the needle valve 95 is substantially inversely proportional to the energizing current value of the electric coil 99 with respect to the flow path 94. It becomes the distance. In order to make the relationship between current value and distance linear, one of the fixed core and the plunger is shaped like a truncated cone, and the other one is shaped like a conical hole with a corresponding bottom, as described above.

As a result of the above, the output port 84 is cursed with a pressure that is substantially proportional to the value of the current flowing through the electric coil 99.

This pressure control valve 80fr is a regular f! ! current within the specified range.

A pressure proportional to the pressure is outputted to the output port 84.

FIG. 4 shows an enlarged longitudinal section of the cut valve 70fr.
The valve housing hole drilled in the valve base 71 has a line pressure port 72. Pressure adjustment capo door 3. The oil drain port 74 and the output port door 5 are in communication. Line pressure port 7
2 and the pressure regulation input port door 3 is a ring-shaped first guide 7.
6, and between the pressure regulating input port door 3 and the output port door 5 are cylindrical guides 77a, 77b and 77c.
separated by.・The oil drain port 74 is connected to the second guide 7
It communicates with the guide hole 77c2 of the guide projection 77c1 that guides the tail end of the spool 78 through the ring-shaped groove on the outer periphery of the second guide 77c, and returns the oil leaked to the outer periphery of the second guides 77a, 77b, and 77c to the drain return pipe 12. , the drain return line 12 communicates with the suspension drain I4fr, which is open to the atmosphere, and is open to the atmosphere.

When the spool 78 is driven to the right, the guide hole 77c2
The fluid is discharged to the drain return pipe 12 (pressure released to atmospheric pressure) through the ring-shaped groove on the outer periphery of the second guide 77c and the oil drain port 74, and when the spool 78 is driven to the left, the fluid is discharged into the guide hole 77c2. Drain return pipe] The fluid of 2 is sucked (atmospheric pressure suction).

A spool 78 pushed leftward by a compression coil spring 79 passes through the first and second guides 76.77a to 77c, and the pilot pressure space 7 on the left end surface of the spool 7B
Line pressure is applied to 2p through orifice 72f and line pressure port 72. The guide hole of the central protrusion of the second guide 77c into which the left end of the spool 78 has entered is the second
Ring-shaped groove on the outer periphery of the guide 77c and the oil drain port 7
4 and communicates with the return pipe 11. 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. The spool 78 is the inner lower part 7ao of the second guide 77a.
It is cut off by fully closing the When the line pressure exceeds the predetermined low pressure.

That is, when the pressure in the pilot pressure space 72p exceeds a predetermined low pressure, this pressure causes the compression coil spring 79 to
The spool 79 begins to be driven to the right against the repulsive force of
The pressure regulating input port door 3 communicates with the output port door 5 by moving to the right from the inner lower part 7aO of 7a.

Therefore, when the line pressure (line pressure port 72) rises to a predetermined low pressure, the cut valve 70fr opens the communication between 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). When the flow starts and the line pressure (line pressure port 72) further increases, the pressure regulation input port door 3 (pressure regulation output of the pressure control valve 80fr) and the output port door 5 (shock absorber 101
fr) 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.

As described above, when the pressure in the front wheel high-pressure supply pipe 6 decreases below a pressure equal to the repulsive force of the compression coil spring 79, the cut valve 70fr automatically closes the pressure control valve 80f.
r and the suspension 100fr, and the release of pressure from the suspension 10Ofr to the pressure control valve 80fr is automatically prevented.

When the pressure in the front wheel high-pressure supply pipe 6 temporarily or vibrably drops to an extent that does not substantially reduce the suspension pressure, the pilot pressure space 7 with such low pressure
The orifice 72f suppresses the spread to the pilot pressure space 72p, that is, the orifice 72f attenuates the temporary pressure wave from the front wheel high pressure supply pipe 6 to the pilot pressure space 72p.
The impact noise or metal vibration noise of the 0fr spool 78 (due to collision with the edge of the open lower 7ao) is suppressed or eliminated,
Further, pressure shocks and pressure vibrations are substantially prevented from being applied to the output port 84 of the pressure control valve 80fr.

Further, the guide hole 77c2 that guides the spool 78 is connected to the low pressure port 85. which causes pressure fluctuations due to the reciprocating movement of the spool 91 of the pressure control valve 80fr. This is because it is connected to a drain return pipe 12 which is open to the atmosphere and is separate from the return pipe 11 that communicates with the drain oil port 74.

Due to pressure fluctuations in the return pipe 11, the spool valve body 78
Then, the erroneous driving force that opens and closes the opening lower 7aO between the output port 84 of the pressure control valve 80fr and the suspension supply pressure line no longer acts on the output port 84 of the pressure control valve 80fr, and the erroneous pressure fluctuation caused by the opening and closing drive stops acting on the output port 84 of the pressure control valve 80fr. Therefore, the operation of the pressure control valve 80fr will not be disturbed.

FIG. 5 shows an enlarged longitudinal section of the relief valve 60fr, and the input port 2 and the low pressure port 63 are opened in the valve housing hole of the valve base 61. A nine 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 a filter 65. A valve body 66 having an orifice in the center is inserted into the first guide 64, and the valve body 66 is pushed to the left by a compression coil spring 66a. The space in the first guide 64 that accommodates the valve body 66 and the compression coil spring 66a is
It communicates with the input port 2 through the orifice of the spring seat 66b, and also communicates with the second guide 6 through the opening of the spring seat 66b.
A conical valve body 68 that communicates with the inner space of the spring seat 6 is pushed to the left by the repulsive force of the compression coil spring 69 .
The opening of 6b is closed. Input Portro 2 pressure (
When the control pressure) is less than a predetermined high pressure, the pressure in the storage space of the coil spring 66a, which communicates with the input port 2 through the orifice of the valve body 66,
Since the repulsion force of valve body 68 is relatively lower than that of valve body 9.

As shown in FIG. 5, the central opening of the valve seat 66b is closed, and therefore the output port 2 communicates with the low pressure port 63 through the hole 67a. The inner space of the second guide 67 is cut off. 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 66.
b, the valve body 68 begins to be driven to the right by this pressure, and when the pressure of 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.

Furthermore, if a shocking high pressure is applied to the input port 2.

When the valve body 66 is driven to the right, the input port 2 communicates with the valve housing space of the base body 61 through the side port 64a of the first guide 64 and communicates with the low pressure port 63. Since this passage area is large, the output port 2 sudden pressure rise (pressure shock)
is buffered.

FIG. 6 shows an enlarged longitudinal cross-section of the main check valve 50. An input port 52 and an output port 53 communicate with a valve housing hole formed in a valve base 51. A cylindrical valve seat 54 with a bottom is housed in the valve housing hole, and a communication port 55 of the valve seat 54 is inserted into the valve seat 54.

The ball valve 57 pushed by the compression coil spring 56 is closed, but when the pressure at the input port 52 is higher than the pressure at the output port 53, the ball valve 57 is pushed to the right by the pressure at the input port 52 and the flow is allowed to flow. The port 55 is opened, that is, oil flows from the input port 52 to the output port 53 direction. but.

When the pressure in the output port 53 is higher than the pressure in the input port 52, the ball valve 57 closes the communication port, so that oil does not flow from the output port 53 toward the input port 52.

FIG. 7 shows an enlarged longitudinal section of the bypass valve 120.
The input port 121 communicates with the inner space of the first guide 123, and a compression coil spring 124b is connected to the inner space.
The valve body 124a pushed to the left is housed. This valve body 124a has an orifice at the center of the left end surface, and the input port 121 is connected to the first guide 1 through this orifice.
It communicates with 23 inner spaces. The inner space has a flow path 122
It communicates with the low pressure port 122 through b, but this flow path 1
22b is opened and closed by a needle valve 125.

It consists of a needle valve 125 to an electric coil 129. The solenoid device includes a needle valve 95 to an electric coil 9 shown in FIG.
The solenoid device has the same structure and dimensions as the solenoid device No. 9 (common design for the pressure control valve and the bypass valve), and the distance of the needle valve 125 with respect to the orifice 122b is substantially inversely proportional to the energizing current value of the electric coil 129. Since the flow opening degree of the orifice 122b is inversely proportional to this distance, the flow from the input port 121 passes through the orifice of the valve body 124a, passes through the inner space of the first guide 123, and enters the orifice 12.
The oil flow rate passing through 2b to the low pressure port 122 is
It is proportional to the differential pressure across the orifice on the left end surface of the valve body 124a.

As a result of the above, the pressure at the input port 121 is
The pressure is substantially proportional to the current value of 29. This bypass valve 120 sets the pressure (line pressure) at the input port 121 to a pressure proportional to one energizing current within a predetermined range. Also, when the ignition switch is off (engine stopped: pump l stopped), the electric coil 129
By stopping the energization, the needle valve 125 moves to the rightmost side, and the input capo-121 (line pressure) becomes a low pressure near the return pressure.

When the pressure of the input port 121 rises shockingly,
The valve body 124a is driven to the right by receiving this pressure on the left end face, and the low pressure port 122a communicates with the low pressure port 122.
communicates with the input port 121. Low pressure port 122a
Since is a relatively large opening, the impulsive rising pressure in the input port 21 immediately escapes to the low pressure port 122a.

The relief valve 60m is the relief valve 60f mentioned above.
The structure is the same as that of r, but the valve body has a conical shape (68:
A compression coil spring (69) presses the spring (Fig. 5).

The spring force is said to be a little small, and the input port (6
When the pressure of 2) (the pressure of the high pressure port 3) is less than the predetermined high pressure, which is a little lower than the pressure that releases the pressure of the input port 2 of the relief valve 60fr to the low pressure port 63, the input port (62) It is cut off from the low pressure port (63). When the pressure of the input port (62) (pressure of the high pressure port 3) becomes equal to or higher than a predetermined high pressure, the valve body (68) is driven to the rightmost side. That is, the pressure in the input port (62) is released to the low pressure port (63).

The pressure in the high pressure port 3 is suppressed to a predetermined high pressure or less.

With the above configuration, in the vehicle body support device shown in FIG. is prevented.

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, and the shocking pressure propagates to the high pressure supply pipe 8! !
to oppose

The bypass valve 120 substantially linearly controls the pressure in the rear wheel high pressure supply pipe 9 within a predetermined range, and maintains the pressure in the rear wheel high pressure supply pipe 9 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, the ignition switch is opened (
When the engine is stopped (pump 1 stopped), the power supply is cut off and the flow is passed through the rear wheel high pressure supply pipe 9 to the return pipe 11 to release the pressure in the rear wheel high pressure supply pipe 9 (high pressure supply pipe 8) 8 Pressure control Valve 80fr, 80f L, 80rr, l1l
Or L is an electric coil (9
9) is controlled, and the required support pressure is output to the output port (84). When shock pressure from the suspension propagates to the output port (84), do this!
1 to suppress disturbances in the pressure control spool (91) (disturbances in the output pressure). In other words, the required pressure is stably applied to the suspension.

Cut valve 70fr, 70f L, 70rr, 70
r L is line pressure (front wheel high pressure supply pipe 6. rear axle high pressure supply pipe 9)
) is less than a predetermined low pressure, the suspension supply pressure line (the output port 84 of the pressure control valve and the suspension lever) is shut off to prevent pressure from escaping from the suspension, and when the line pressure is above the predetermined low pressure, Fully open the supply pressure line. This automatically prevents an abnormal drop in suspension pressure when line pressure is low.

Relief valve 60fr r 60f L + 60r
r * 60r L limits the pressure (mainly suspension pressure) in the suspension supply pressure line (between the output port 84 of the pressure control valve and the suspension) to below the high pressure upper limit, and prevents the lifting of wheels and the loading of heavy objects. When there is a shocking increase in pressure in the supply pressure line (suspension) due to a sudden drop in pressure, etc., this pressure is released to the return pipe 11 to alleviate the impact on the suspension, as well as the hydraulic line connected to the suspension and the mechanical elements connected to it. Increases durability.

〔Effect of the invention〕

As described above, according to the pressure control device of the present invention, the high pressure pipe (
6) pressure is applied to the spring member (70fr) of the cut valve system [(70fr)
79), the cut valve device [(70fr) automatically closes the pressure control valve (80fr).
) and suspension (100fr).

Pressure control valve (80f) from suspension (100fr)
r) is automatically prevented from releasing pressure.

The guide hole (77c2) that guides the valve body (78) for performing the above-mentioned shutoff communicates with the air-released fluid path (74, 12) that is separate from the first pipe path (11). Conduit (
11) causes the valve body (78) to open between the output port of the pressure control valve and the suspension supply pressure line (7).
7ao) The erroneous driving force that drives opening and closing no longer acts.

No disturbance is caused to the pressure control operation of the pressure control valve.

[Brief explanation of the drawing]

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. 1. FIG. 6 is an enlarged longitudinal sectional view of the main check valve 50 shown in FIG. FIG. 7 is an enlarged longitudinal sectional view of the bypass valve 120 shown in FIG. 1. 1: Pump 2: Reservoir 3: High pressure port 4: Accumulator 6: Front shaft high pressure supply pipe 7
: Accumulator 8: High pressure supply pipe 9: Rear shaft high pressure supply pipe 10: Accumulator 11: Reservoir return pipe 12 Nidrain return pipe 13f L, 13fr, 1.3r L, 13r
r, 13rm, 13rt: Pressure sensor 1 'If
L + 14fr t 14r L l 14rr
: Atmospheric release drain 15f L r 15fr, 1
5r L l 15rr: Vehicle height sensor 28: Hot water level detection switch 50: Main check valve 51: Valve base 52: Input port 53: Output port
54: Valve seat 55: Flow port 56: Compression coil spring 57: Ball valve 60fr, 60f L
, 60rr, 60r L: Relief valve 61: Valve base 62: Input port 63: Low pressure port 64: First guide 65: Filter 66:
Valve body 67: Second guide 68: Valve body 69: Compression coil spring 71: Valve base 72 Ni line pressure port 72f Niorifice 72 p: Pilot pressure space 73: Pressure regulation input port 74: #Oil port 75: Output port door 6: First Guide 77: Guide 77ao
:Open lower 8 Nisbourg 79:Compression coil spring 80fr 80f 80rr 80r L:
m 181 Ni sleeve 82 Ni line Pressure port 83: Groove 84: Output port 85: Low pressure port 86: Groove 87: High pressure port 88: Target pressure space
88f Niorifice 89: Low pressure port 90; Spool
9N groove 92: Compression coil spring
93: Valve body 94: Flow path 95: Needle valve 96: Fixed core 97: Plunger 98a:
Yoke 98b: End plate 98c: Low pressure port
99: Electric coil 100fr ], 00f 100r
r 100rL: Suspension 101fr 1 (Hf
1o1rr 101r: Shock absorber 1
02fr, 102f L, 102rr, 102
r L: Piston rod 103: Piston 10
4: Inner cylinder 105: Upper chamber 106: Lower chamber
107: Side entrance 108: Upper and lower penetration hole 109
: Valve damping valve device 110: Between lower chambers 111: Piston 112: Lower chamber 113 Two upper chambers 1
14: Outer cylinder 120: Bypass valve 121: Input port 122: Low pressure port 122a: Low pressure port 122
b: Channel 123: First guide 124: First guide 124a: Valve body 124b: Compression coil spring 129: Electric coil 125: Needle valve -1=

Claims (1)

[Scope of Claims] A pressure source that supplies fluid drawn 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; a line pressure that communicates with the high-pressure pipeline; a low pressure port that communicates with a first conduit that returns fluid to the reservoir; an output port that applies pressure to the suspension; a target pressure space that communicates with the line pressure port via an orifice; In response, this pressure drives the flow in the direction of lowering the flow rate between the line pressure port and the output port and increasing the flow rate between the low pressure port and the output port, and receives the pressure of the target pressure space at the other end. a spool driven by pressure in a direction that lowers the degree of flow between the line pressure port and the output port and increases the degree of flow between the low pressure port and the output port, and the target pressure space for the low pressure pipe that returns fluid to the reservoir. A pressure control valve device having a valve body that regulates the degree of flow of the high-pressure pipe, and an electrically energized drive means that drives the valve body in a direction that increases or decreases the degree of flow; a pilot pressure space that receives the pressure, an input port that receives the pressure regulated by the pressure control valve, an output port that communicates with the suspension, and a valve that is driven by the pressure of the pilot pressure space and allows flow to flow between the input port and the output port. a guide member having a guide hole that communicates with a fluid path separate from the first conduit and that is open to the atmosphere and guides the valve body; and a guide member that blocks the valve body between the input port and the output port. A suspension pressure control device comprising: a cut valve device having a spring member driven in the direction;