JPH02270620A - Pressure control device for suspension - Google Patents

Abstract

PURPOSE:To reduce excessive consumption of a high-pressure liquid due to oversensitive action of a needle valve by constituting a pressure control means for controlling the suspension pressure so that a target-pressure space being the driving source for displacing a spool is communicated with a low-pressure pipe line via a needle valve equipped with a sliding resistance means. CONSTITUTION:In a device in which the discharged oil of a hydraulic pump is fed through high-pressure feed pipes to the suspensions for respective wheels via a pressure control valve 80fr, the pressure control valve 80fr is constituted so as to be provided with a spool 90, a needle valve 95, and electrical driving means (96 to 99) for driving the needle valve 95. And the spool 90 is provided so as to be driven by receiving the pressure in an output port 84 for applying a pressure to the suspensions on one end thereof, while by receiving the pressure in a target-pressure space 88 being communicated with a line-pressure port 82, communicated with a high-pressure feed pipe, via an orifice 88f on the other end thereof. And the needle valve 95 equipped with sliding resistance means 95a, 95b is provided so as to regulate the flow rate between the target-pressure space 88 through a passage port 94 and a low-pressure port 85 communicated with a low-pressure pipe line.

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, in Japanese Utility Model Publication No. 62-38402, the steering angular velocity is detected by a sensor, and when the vehicle speed is above a set value and the steering angular velocity is above the set value, the damping force or spring force of the suspension is increased. Suspension pressure control has been proposed to

In addition, 1, for example, Japanese Patent Application Laid-Open No. 106133/1983 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 turning pattern of the vehicle is determined based on the steering angle and the steering angular velocity, and the gain is changed accordingly. 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 proposed in Japanese Patent Application No. 365/1983 includes a line pressure port communicating with a high pressure pipe, a low pressure port communicating with a fluid return pipe to the reservoir, an output port that applies pressure to the suspension, A target pressure space that communicates with the line pressure port through an orifice.

The pressure of the output port is received at one end, and this pressure 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, thereby increasing the pressure in the target pressure space. A spool received at the end and driven by this pressure in a direction to increase the degree of communication between the line pressure port and the output port and to decrease the degree of communication between the low pressure port and the output port, and a fluid return pipe to the target pressure space and reservoir. A needle valve that defines the degree of flow between the passage and the passage, and a solenoid that drives the needle valve in a direction to increase or decrease the degree of flow.

By controlling the energizing current of the solenoid, the balancing force of the needle valve is determined and a corresponding required pressure is created in the target pressure space, and a pressure substantially equal to the pressure of this target pressure space is applied to the output port ( suspension).

(Problem to be Solved by the Invention) By the way, the pressure in the target pressure space (target pressure) can be set by adjusting the degree of communication with the fluid return pipeline to the reservoir (hereinafter referred to as return pipeline) using a needle valve. However, in a pressure control valve that applies this pressure to one end of the spool and applies the pressure of the output port to the other end of the spool to output a pressure corresponding to the target pressure, for example, when a wheel rides on a protrusion on the road surface, the suspension pressure increases. As a result, the pressure at the output port of the pressure control valve increases rapidly, and the spool moves in the direction of contracting the target pressure space (lowering the pressure at the output port), causing the pressure in the target pressure space to increase. Pressure increases. This pressure acts on the needle valve, and the needle valve is pushed in a direction that increases the degree of communication between the target pressure space and the fluid return line to the reservoir (in a direction that lowers the pressure in the target pressure space). This push causes the needle valve to move in that direction (retreat), but if the resistance to this movement of the needle valve is large.

The retreat of the needle valve is delayed, resulting in a delay in the pressure drop in the target pressure space, and as the spool moves, the pressure drop in the output port is delayed. In this way, if the response of the spool, needle valve, etc. is slow as described above to the pressure increase at the output port of the pressure control valve due to the wheel running onto a convex part of the road surface, the suspension pressure may not be lowered in time. The vehicle body lifts up and a shock is applied to the driver.

Therefore, the needle valve is required to be easy to move.
On the other hand, if the movement resistance of the needle valve is too small, the needle valve responds too sensitively and retreats quickly, causing the pressure in the target pressure space to drop quickly, making it easy for the spool to move, and the pressure at the output port to drop quickly. moves excessively in the pressure-reducing direction, causing the pressure at the output port to drop too much.

In this case, the propagation of the shock caused by the thrusting of the wheels against the vehicle body is more than adequately buffered, but the amount of suspension pressure released is too large, and the suspension pressure (pressure control valve Since the pressure at the output port becomes too low, the spool moves in the direction of increasing the pressure at the output port, and pressure is supplied to the suspension from the high pressure line through the pressure control valve. Therefore, the amount of high-pressure fluid consumed is large, the load on the pressure source is large, and pressure fluctuations (hunting) are likely to occur at the output port of the pressure control valve.

An object of the present invention is to reduce the high consumption of high-pressure fluid due to the oversensitive operation of the needle valve of the pressure control valve mentioned above.

(Means for Achieving Problem B) The pressure control device of the present invention supplies fluid at high pressure to a high pressure pipe (6) for supplying pressure fluid to a suspension (100 fr) that expands and contracts according to the supplied pressure. A supply pressure source (1); and a line pressure port (82) communicating with the high pressure pipe (6), a low pressure port (85) communicating with the low pressure pipe (11), and an output that applies pressure to the suspension (100 fr). The target pressure space (84) communicates with the line pressure port (87) via the orifice (88f).
8), one end receives the pressure of the output port (84), and this pressure causes the line pressure port (82) and the output port (84) to
The low pressure port (85) and output port (85) are
4) is driven in the direction of increasing the permeability of the target pressure space (
88) is received at the other end, and this pressure increases the degree of communication between the line pressure port (82) and the output port (84), and lowers the degree of communication between the low pressure port (85) and the output port (84). The spool (90) is driven in the direction, and its tip faces the communication port (94) between the target pressure space (88) and the low pressure pipe line (11), and is movable in the opposite direction. Sliding resistance means (95a, 95b
.

95a1 to 95aa) and defines the degree of communication between the target pressure space (88) and the low pressure pipe (11) through the one communication port (94), and the needle valve (95) is connected to the opposite side. Valve support member (95G) that guides the valve in a movable direction
), and electrically energized driving means (96, 97) for driving the needle valve (95) in the direction of increasing or decreasing the degree of flow.
, 98a.

98b, 99), pressure control valve system with! i! (8
0fr) ; Note that the symbols in parentheses are attached to corresponding elements in the embodiments described later.

(Function) Electrically energized drive means (96, 97, 98a, 98b
, 99) drives the needle valve (95) to a certain position, the flow defined by the communication port between the target pressure space (88) and the low pressure pipe (11) and the tip of the needle valve (95) occurs. The degree is
The pressure in the target pressure space (88) corresponds to the position of the needle valve (95), and the pressure in balance with this pressure is the pressure in the pressure control valve device (80fr).
) appears at the output port (84) of (suspension 1
00fr), drive means (96, 97, 98a,
When 98b, 99) drive the needle valve (95) in the direction of increasing the degree of flow, the pressure in the target pressure space decreases, the pressure in the suspension (100fr) decreases, and the vehicle height decreases. When driven in the direction of lowering the target pressure space, the pressure in the target pressure space increases and the pressure in the suspension (100fr) increases (vehicle height increases). Therefore, the driving means (96°97.98a, 98b, 99) with needle valve (
By changing the position of 95), the vehicle height can be adjusted higher or lower.

When the needle valve is set at a certain position, (A) when a wheel rides on a convex part of the road surface, the wheel pushes up from the road surface and the suspension pressure increases.

Then, the output port (80fr) of the pressure control valve device 1 (80fr)
4) pressure increases and the stay (90) moves in the decreasing direction (
(in the direction of increasing the degree of communication between the output port 84 and the low pressure port 85 and decreasing the degree of communication between the output port 84 and the high pressure port 85).

This buffers the propagation of the wheel thrust impact to the vehicle body. This movement of the spool (90) increases the pressure in the target pressure space (88), and this pressure is applied to the tip of the needle valve (95) through the communication port (94), causing the needle valve (95) to retreat and The flow rate of the flow port (94) is increased.

That is, the degree of flow from the target pressure space (88) to the low pressure pipe (11) increases, and the pressure in the target pressure space (88) decreases.

(B) When the axle lifts up, the suspension pressure decreases, so the spool (90) moves in the pressure increasing direction (output port 8
4 and the low pressure port 85, and the output port 84
and the direction of increasing the degree of flow through the high pressure port 85).

This movement of the spool (90) lowers the pressure in the target pressure space, and a force acts on the needle valve (95) in the direction of lowering the degree of flow through the flow port (94).
88) and the low pressure pipe line (11) becomes low, increasing the pressure in the target pressure space (88).

When the wheel falls into a concave part of the road surface, the suspension pressure decreases, and the pressure control valve system 51 (80fr) operates as described in (B) above.
When the wheel goes over the recess, the above operation (A) is performed.

Due to this operation of the pressure control valve system W1 (80fr).

When driving on a rough road where the wheel runs over a convex part or falls into a concave part, the needle valve (95) adjusts the pressure in the target pressure space to the electrically energized drive means (96, 97, 98a, 98b, 9
The spool (90) operates to maintain a constant pressure corresponding to the position determined by the output port (8), and the spool (90)
4. Since the suspension operates to maintain a constant pressure (suspension pressure), the vertical vibration of the vehicle body due to the vertical vibration of the axle is buffered.

Thus, the needle valve (95) is in contact with the sliding resistance means (95
a, 95b, 95a1 to 95a3), and the valve support member (95G) movably guides the needle valve (95), so when the needle valve (95) moves, for example, the hole ( The needle valve (95) moves when the needle valve (95) retreats inward from the hole (95h) and when the needle valve (95) advances outward from the hole (95h) at the above CB). , sliding resistance means (95a, 95b
, 95a 1 to 95a3) by the needle valve (95)
Other objects and features of the present invention will become clear from the following description of embodiments with reference to the drawings.

(Example) FIG. 1 shows an outline of the mechanism of the vehicle body support system 4. A hydraulic pump 1 is a radial pump, which is disposed in the engine room, and is rotationally driven by the vehicle engine (not shown). The oil in the reservoir 2 is sucked in, and the oil is discharged at a predetermined flow rate to the high pressure port 3 at a rotational 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 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 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 100 fL.

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 wheel suspensions 100r L and 100rr communicates with each other, and an accumulator 7 (for the front axle) is connected to the front wheel high pressure supply pipe 6 .

An accumulator 10 (for the rear axle) is connected to the rear wheel high-pressure supply pipe 9.

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 axle high pressure supply pipe 6 (hereinafter referred to as front wheel line pressure) is set to the required pressure (pressure crab suspension support pressure corresponding to the current value of the electric coil) and the cut valve 70fr and the relief are set. 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) and the hollow piston rod 102fr of the shock absorber 101fr of the suspension 100fr.
The pressure control valve 80fr is prevented from leaking from the front wheel side line pressure to the pressure control valve 80fr while the front wheel side line pressure is above a predetermined low pressure.
The output pressure (suspension support pressure) 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 used as a return flow to 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 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 wheel) 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 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
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). suspension 100f
The L shock absorber 101f is applied to the L piston rod 102f.

Pressure control valve 80rr, cut valve 7 similar to the above
0rr + relief valve 60rr to vehicle height sensor 1
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 101rr of the suspension 100rr.
give to

Furthermore, a pressure control valve 80rL, a cut valve 70rL, a relief valve 60rL, a vehicle height sensor 15rL, and a pressure sensor 13rL, which are similar to those described above, are similarly installed and assigned to the front left wheel suspension 100rL. A control valve 80rL is connected to the rear wheel high-pressure supply pipe 9 to apply the required pressure (support pressure) to the suspension 10.
0rL to the piston rod 102rL of the shock absorber 101rL.

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).
is equipped with, from hydraulic pump 1 to rear wheel suspension 1.
Piping lengths up to 00rr and 100rL.

Hydraulic pump 1 to front wheel suspension 100fr.

It is longer than the piping length up to 100f L, so the pressure drop due to the piping is large on the rear wheel side.If an oil leak occurs in the piping, the pressure drop on the rear wheel 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 of the reservoir return pipe 11 is lowest at the end on the reservoir 2 side, and the further away from the reservoir 2 the pressure is.

Since the pressure tends to increase, the reservoir return pipe 1
The pressure No. 1 is also detected on the rear wheel side by a pressure sensor 13rt.

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 release from the shock absorber), engine (pump L)
Lighten the load when restarting.

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 into the upper chamber 105 in the inner cylinder 104, and further through the upper and lower through holes 108 of the piston 103 into the lower chamber 10.
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 W109. The upper space of the damping valve system fi109 is divided into a lower chamber 112 and an upper chamber 113 by a piston 111, and the oil in the lower space 11G flows through the damping valve system [109] into the lower chamber 112, but the oil in the lower space 11G flows through the damping valve system [109]. is filled with high pressure gas.

When the piston rod 1.02fr 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 suddenly increases, and the pressure in the upper space 110 similarly increases. The pressure will suddenly become higher than the pressure in the lower chamber 112. 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 wheels! ! It buffers the (upward) propagation to the piston rod 102fr. In other words, the axle impact l! 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 wheel, the internal pressure in 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 into the upper space 110, which causes the piston 111 to descend, and the impact from the wheels! It buffers the (downward) propagation to the piston rod 102fr. That is,
Axle impact on the car body! The propagation of (downturn) will be buffered.

In addition, in order to raise the vehicle height, etc., the shock absorber, +<1
As the pressure applied to 01fr increases, lower chamber 1
12 increases, the piston 111 rises, 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, oil leaking into the outer cylinder 114 is substantially hot. However, in order to reduce the vertical movement load on the piston rod 102fr, the seal is designed so 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 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. 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 structures of the other suspensions 100f L, 100rr and 100r L are also the same as those of the suspension 100 described above.
The structure is substantially similar to that of fr.

FIG. 3a 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. At the left end of the spool 90.

A valve housing hole 6 is opened, and this valve housing hole communicates with the groove 91. A compression coil spring 9 is installed in the valve housing hole.
The valve body 93 pushed in step 2 has been 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, the 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. 6 which provides the effect of buffering the rightward movement of the spool 90, and conversely,
This 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 needle valve 95. The needle valve 95 is the communication port 94
When closed, the pressure in the target pressure space 88 communicating with the high pressure port 87 via the orifice 88f becomes the pressure (line pressure) of the high pressure port 87, and the spool 90 is driven to the left.

Groove 91 of spool 90 is 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 applies rightward driving force to the left end of the spool 90. When the needle valve 95 fully opens the communication port 94, the pressure in the target pressure space 88 is narrowed by the orifice 88f, so it is significantly lower than the pressure (line pressure) in the high pressure port 87, and the spool 90 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 of the valve body 93, and the spool 90 The right driving force at the left end decreases. 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.
The result is that output port 84 is substantially inversely proportional to the distance of
At , a pressure appears that is substantially inversely proportional to the distance of the needle valve 95.

The needle valve 95 passes through a fixed core 96 of magnetic material. The right end of the fixed core 96 has a truncated conical shape, 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 that is released to the atmosphere. As a result, the needle valve 95 receives a rightward driving force corresponding to the pressure value (this corresponds to the position of the needle valve 95), and as a result, the needle valve 95 moves toward the flow port 94.
The distance is substantially inversely proportional to the value of the current flowing through the electric coil 99. 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 is shaped like a corresponding conical hole with a bottom, as described above.

As a result of the above, a pressure substantially proportional to the current value flowing through the electric coil 99 appears at the output port 84 .

This pressure control valve 80fr has an energized current within a predetermined range.

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

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

When the energizing current value is set to a certain value, that is, when the energizing current value of the electric coil is set to apply pressure to the suspension to maintain the vehicle height at a certain value, when the wheel hits a convex part of the road surface. When the vehicle runs over the vehicle, the axle is pushed up from the road surface, and (A) suspension 100fr pressure increases. Then, the pressure at the output port 84 of the pressure control valve 80fr increases, and the spool 90 moves in the pressure decreasing direction (to the right in FIG. 3a). This buffers the propagation of the wheel thrust impact to the vehicle body. This movement of the spool 90 increases the pressure in the target pressure space 88 and applies this pressure to the tip of the needle valve 95 through the communication port 94.
moves backward (moves to the right), and the degree of flow through the flow port 94 increases. That is, the degree of flow from the target pressure space 88 to the return pipe 11 through the orifice 88f and the low pressure port 87 increases, and the pressure in the target pressure space 88 decreases. When the wheel thrust is finished, (B) the suspension pressure decreases, so the spool 90 moves in the pressure increasing direction (leftward in FIG. 3a). This movement of the spool (90) lowers the pressure in the target pressure space 88, and a force acts on the needle valve 95 in a direction (to the left) that lowers the degree of flow in the flow port 94, thereby reducing the pressure in the target pressure space 88. The degree of communication with the return pipe 11 decreases, and the pressure in the target pressure space 88 increases.

When the wheel falls into a concave part of the road surface, the suspension pressure decreases and the pressure control valve 80fr performs the operation described in (B) above, and when the wheel goes over the concave part, it operates as described in (A) above.
Perform the following actions.

Due to this operation of the pressure control valve 80fr, the needle valve 95 adjusts the pressure in the target pressure space 88 to the electric coil 9 when driving on a rough road where the wheel runs over a convex part or falls into a concave part.
It operates to maintain the pressure determined by the current value of 9,
In addition, the spool 90 operates to maintain the pressure at the output port 84 (suspension pressure) at a constant pressure despite fluctuations in suspension pressure due to the vertical movement of the wheels, so the vertical vibration of the vehicle body due to the vertical vibration of the wheels is reduced. Buffered.

In Figure 3b, BIB-1 of Figure 3a! Referring to FIGS. 3a and 3b, which show an enlarged cross section of the needle valve 95 taken along the line IB, the needle valve 95 has large diameter lands 95a and 95b, and a hole 95h in the support member 95G.
is inserted into. Lands 95a and 95b of the needle valve 95 are in contact with the inner wall surface of the hole 95h.

Three spiral grooves 95a1 are formed on the side peripheral surface of the land 95a.
~95a3 is engraved and continues on the front and rear surfaces of the land 95a. Therefore, the inner space of the hole 95h is the groove 9
5a1 to 95a3 communicate with a space where the communication port 94 is open, that is, a space where the tip (left end) of the needle valve 95 is located and communicated with the low pressure port 89. land 95b
Three similar spiral grooves are carved into the inner space of the hole 95h and the tail end (right end) of the needle valve 95.
It communicates with the space where is located.

When the needle valve 95 moves, for example, when the needle valve 95 retreats inward (to the right) of the hole 95h in (A) above, the fluid in 605h flows into the spiral grooves 95a1 to 95a3.
69 in (B) above to the outside (left side) of the hole 95h.
When the needle valve 95 advances outward (to the left) of the hole 95h, the fluid from the outside enters the inside (rightward) of the hole 95h through the spiral grooves 95a1 to 95a3. The force trying to prevent movement of the valve 95 is small, and the needle valve 95 can be moved easily. By the way, since the grooves 95a1 to 95a8 are spiral, their total length is relatively long, and the resulting flow resistance is relatively large, thereby suppressing the sensitive movement of the needle valve 95.

It is also brought about by retracting (rightward) movement or advancing (leftward) movement of the needle valve 95. Grooves 95a1 to 95a
Since the groove is spiral, the fluid flow in the groove 3 applies a rotational force about its axis to the needle valve 95, causing the needle valve 95 to rotate. This rotation is effective in preventing the needle valve 95 from becoming stuck (abnormally fixed or unable to move).

In the case of fluid flow through grooves, it is easier to adjust the flow resistance by the length of the groove than by adjusting the opening width of the groove. By doing so, the required flow resistance can be easily set.

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. WR press-fit capo door 3. Drain port 7
4 and an output port door 5 are in communication. The line pressure port 72 and the pressure regulation input port door 3 are separated by a ring-shaped first guide 76, and the pressure regulation input port door 3 and the output port door 5 are separated by cylindrical guides 77a, 77b and 77c.
separated by. The oil drain port 74 is connected to the second guide 77
c communicates with the ring-shaped groove on the outer periphery of the second guides 77a, 7.
The oil leaked around the outer circumferences of 7b and 77c is returned 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 left end of the spool 78 has entered. The guide hole of the central projection of the second guide 77c 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
It is blocked by completely closing the inner opening of 7a. When the line pressure exceeds a predetermined low pressure, this pressure causes the spool 7 to resist the repulsive force of the compression coil spring 79.
9 begins to be driven to the right, and the spool 79 moves to the rightmost position at a pressure higher than the predetermined low pressure. (full throttle), i.e.
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 door 5, and the line pressure (line pressure port 72) rises to a predetermined low pressure, the cut valve 70fr il press-fit capo door 3 (
When the line pressure (port 72) starts to flow between the pressure regulation output of the pressure control valve 80fr (pressure regulation output) and the output port door 5 (shock absorber 101fr), and the line pressure (port 72) further increases, the pressure regulation input port door 3 (pressure regulation output of the pressure control valve 80fr) starts flowing. (output) and the output port door 5 (shock absorber 101fr). 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, and the input port 2 and the low pressure port 63 are opened in the valve housing hole of the valve base 61. 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. 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 repulsive force of the fifth valve body 68 is relatively lower than that of the fifth valve body 68,
As shown in the figure, the central opening of the valve seat 66b is closed,
Therefore, the output port 2 has a low pressure port 63 and a hole 6.
It communicated through 7a. 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 technique 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 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 to the output port 53 direction. However, when the pressure at the output port 53 is higher than the pressure at the input port 52, the ball valve 57 closes the communication port, so that oil does not flow from the output port 53 to 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.

The solenoid device consisting of the needle valve 125 to the electric coil 129 includes the needle valve 95 to the 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 the supplied current within a predetermined range. Also, when the ignition switch is off (engine stopped: pump 1 stopped), the electric coil 12G
By stopping the energization, the needle valve 125 moves to the rightmost side, and the input port 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 60 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 port (62) has a slightly small spring force.
pressure (pressure at high pressure port 3) is the pressure at the relief valve 60
When fr is less than a predetermined high pressure, which is a pressure slightly lower than the pressure that releases the pressure of the input port 2 to the low pressure port 63, the output port (62) is cut off from the low pressure port (63). When the pressure at the input port (62) exceeds a predetermined high pressure, the valve body (68) is driven to the rightmost direction.

In other words, the pressure at the input port (62) is lower than that at the low pressure port (
63), and 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. 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 60 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, it suppresses the pressure in the return pipe 1.
1 to prevent the propagation of the impulsive pressure to the high-pressure supply pipe 8.

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, when the ignition switch is open (engine stopped: pump 1 stopped), electricity is cut off, and the rear wheel high pressure supply pipe 9 is passed through the return pipe 11, and the rear wheel high pressure supply pipe 9 (high pressure supply pipe 8 is stopped). ) to release the pressure.

Pressure control valve 80fr, 80f L, 80rr, 80r
L is an electric coil (99) so as to apply the required support pressure to the suspension by suspension pressure control.
The energizing current value is controlled, and the required support pressure is output to the output port (84). When impact pressure from the suspension propagates to the output port (84), it is reduced to IN 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
, 70rL shuts off the suspension supply pressure line (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 wheel 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. Due to this.

Abnormal drop in suspension pressure when line pressure is low is automatically prevented.

Relief valve 60fr, 60f L, 60rr, 6
0rL limits the pressure (mainly suspension pressure) in the suspension supply pressure line (between the a port 84 of the pressure control valve and the suspension) to below the high pressure upper limit, and prevents the vehicle from lifting up a wheel or loading a heavy object. When there is a shocking pressure increase in the supply pressure line (suspension) due to throwing, etc., this is released to the return pipe 11, which alleviates the impact on the suspension and improves the durability of the hydraulic line connected to the suspension and the mechanical elements connected to it. enhance sex.

〔Effect of the invention〕

As described above, according to the pressure control device of the present invention, the driving means (
By changing the position of the needle valve (95) in 96, 97, Ha, 98b, 99), the vehicle height can be adjusted high or low.

When driving on a rough road where the wheel runs over a convex part or falls into a concave part, the needle valve (95) adjusts the pressure in the target pressure space to the electrically energized driving means (96, 97, 98a, 98b).
.

99) operates to maintain a constant pressure corresponding to the defined position, and the spool (90) despite fluctuations in suspension pressure due to up and down movement of the wheels.

Since it operates to maintain the output capo (84, suspension pressure) at a constant pressure, the vertical vibration of the vehicle body due to the vertical vibration of the wheels is buffered.

Thus, the needle valve (95) is in contact with the sliding resistance means (95
a, 95b, 95a1 to 95a3), and the valve support member (95G) movably guides the needle valve (95), so that when the needle valve (95) moves, for example, the needle valve (95) When retracting and when the needle valve (95) advances, hypersensitive movement of the needle valve (95) is suppressed.

[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. 3a is an enlarged longitudinal sectional view of the pressure control valve 80fL shown in FIG. 1. FIG. 3b is an enlarged sectional view of the needle valve 95 taken along the line IIIB--IIIB shown in FIG. 3a. 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: 7 Cumulator 6: Front shaft high pressure supply pipe 7
: Accumulator 8: High pressure supply pipe 9: Rear wheel high pressure supply pipe 10: Accumulator 11: Reservoir return pipe 12 Nidrain return pipe 13f L I
I 3fr r l 3r L l l 3rr,
13rm p 13rt: Pressure sensor 14f L,
14fr, 1.4r L, 14rr: Drain 15f1-. 15fr, 15rl, 15r
r: Vehicle height sensor 16p: Vertical acceleration sensor
16r: Lateral acceleration sensor 17: Microprocessor
18: Microprocessor 19 H battery
20: Ignition switch 21
: Constant voltage power supply circuit 22: Relay 23 Backup fl source circuit 24 Brake lamp
25: Vehicle speed synchronization pulse generator 26: Rotary encoder 27: Absolute encoder 28: Hot water level detection switch 291 to 293: A/D
Converters 301 to 303: Signal processing circuit 31:
Low-pass filter 32: Duty controller
33: Coil driver 34: Input/output circuit
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 competition fr, 6 shidan" Uraranu lrq: IJ history: Valve 61: Valve base 62: Input port 63: Low pressure port 64: First guide 65: Filter 6
6: Valve body 67: Second guide 68: Valve body
69: Compression coil spring 71: Valve base
72 line pressure port 73: Pressure regulation input port door 4:
Wandering oil port 75: Output port 76: First guide 77: Guide 78: Spool 79: Compression coil spring 80fr 80k 80rr 80rL: Pressure-control valve 8
1 Ni sleeve 82 Ni line pressure port 83: Groove 8
4: Output port 85: Low pressure port 86: Groove 8
7: High pressure port 88: Target pressure space 88f Niorifice 89: Low pressure port 90 Nisbourg
91: Groove 92: Compression coil spring 9
3: Valve body 94: Flow port 95: Two dollar valve
95a, 95b: Lands 95a1 to 95a3: Spiral groove 95G: Support member 95h: Hole
96: Fixed core 97: Blungier 98a
:Yoke 98b:End plate 98C:Low pressure port 99:Four and four rules for electric coils-, 10's attack 1: Suspension 2 and biliary ear h
Mkawa t-2 Shishichi D101rL: Shock absorber 10
2fr, 102k, 102rr, 102rL: Piston rod 103: Piston 104: Inner cylinder
105: Upper chamber 106: Lower chamber 107: Side entrance
108: Upper and lower penetration RO 109: Valve damping valve device 1!
110. Insufficiency 111: Piston 112:
Lower chamber 113: Upper chamber 114: Outer cylinder 1
22: Low pressure port 122a: Low pressure port 122b
: Channel 123: First guide 124a: Valve body! 24b
:Compression coil spring 125:Two dollar valve 129:Electric coil

Claims (1)

[Scope of Claims] A pressure source that supplies fluid 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 line pressure port that communicates with the high-pressure pipeline; A low pressure port that communicates with the low pressure pipe, an output port that applies pressure to the suspension, a target pressure space that communicates with the line pressure port via an orifice, and a line pressure port and output port that receive the pressure of the output port at one end and use this pressure. The pressure in the target pressure space is received at the other end, and this pressure increases the flow rate between the line pressure port and the output port. a spool that is driven in a direction to lower the degree of flow between the low pressure port and the output port; A needle valve having a sliding resistance means for slowing down this movement and regulating the degree of communication between the target pressure space and the low-pressure pipe through the communication port, the needle valve being movably guided in the opposing direction. A pressure control valve device comprising: a valve support member for controlling the flow rate; and an electrically energized drive means for driving the needle valve in a direction that increases or decreases the degree of flow.