JPH0632218A - Liquid pressure control device - Google Patents

Abstract

PURPOSE:To provide a liquid pressure control device which causes no delay in increasing the liquid pressure and ensures sufficient slow pressure intensifying range by providing a directional control part, thereby supplying an operating fluid to a target device for liquid pressure supply by switching to either one of without throttling and with throttling and changing the spring constant of a spring which works on a valve element between the directional control operation and the slow pressure intensifying control operation. CONSTITUTION:If the slip rate exceeds the proper range, when an electromagnetic switch valve 80 opens, a spool 44 advances against the energizing force of a second spring 90 so that an output pressure port 62 communicates with a low pressure port 68. In such a condition, a part having a small section of a throttle groove 100 forms a throttle passage 102, and the brake cylinder pressure in a control pressure chamber 72 increases slowly. Secondaly, the spool 44 is retreated to gradually increase the sectional area of the throttle passage 102 so that the flow rate of a brake fluid is kept constant substantially. A directional control part 98 is switched so that a brake fluid is supplied to a brake cylinder 20 through a high pressure port 48 and a high pressure chamber 56. The slow pressure intensifying range can be ensured widely by actuating a first spring 88 only on the way of retreating the spool 44.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device provided between a hydraulic pressure source, a device to be supplied with hydraulic pressure and a reservoir for controlling the hydraulic pressure of the device to be supplied with hydraulic pressure. The present invention relates to a hydraulic pressure control device that gradually increases the hydraulic pressure of a device to be supplied with two types of gradients.

[0002]

2. Description of the Related Art In this type of hydraulic pressure control device, the hydraulic pressure of the hydraulic pressure supply target device is suddenly increased by changing the flow rate of the hydraulic fluid supplied from the hydraulic pressure source to the hydraulic pressure supply target device. Then, there is one that switches to a state of gradually increasing. An example is a hydraulic pressure control device of a reflux type anti-skid type hydraulic brake device. In this hydraulic brake device, during normal braking in which the rotation of the wheels is suppressed based on the operation of the brake operating member, the flow of brake fluid from the master cylinder that is the hydraulic pressure source to the brake cylinder is not throttled, and the brake cylinder pressure is reduced. Is rapidly increased and during anti-skid control, the brake cylinder pressure is reduced by discharging the brake fluid from the brake cylinder to the reservoir, and then the flow of brake fluid supplied from the master cylinder to the brake cylinder is throttled. The brake cylinder pressure is gradually increased by making the flow rate smaller than that during normal braking.

The hydraulic pressure control device of the reflux type anti-skid type hydraulic brake device described in JP-A-64-70253 is an example thereof. This hydraulic control device 200 is shown in FIG.
Shown in. The hydraulic control device 200 includes a valve element 212 and a control piston 214 slidably fitted in a housing 210.
It has and. The valve element 212 and the control piston 214 are integrally configured, and by fitting these into the housing 210, the space inside the housing 210 is partitioned into a first liquid chamber 216 and a second liquid chamber 218. ing. Although the valve element 212 is a cylindrical member, the plurality of small through holes 220 and the small through holes 22 are axially spaced from each other on its peripheral wall.
A large through hole 222 having a diameter larger than 0 is formed.

On the other hand, an annular groove 224 is formed on the inner peripheral surface of the housing 210, and the valve element 212 and the control piston 214 are kept in the retracted end position shown in the figure by the urging force of the spring 226. , All the small through-holes 220 and the large through-holes 222 communicate with the annular groove 224, but each time the valve element 212 and the control piston 214 advance a certain distance against the biasing force of the spring 226, the large through-holes 222 and Each small through-hole 220 has an annular groove 2
It is designed to come off from 24. That is, port 2
The flow passage area from 28 to the port 230 is changed stepwise as the valve element 212 advances.

The first liquid chamber 216 includes a port 228 and a liquid passage 2.
32 is communicated with the pressurizing chamber of the master cylinder 233, and the annular groove 224 serves as the port 230 and the liquid passage 234
Is connected to the brake cylinder 235 by. The liquid passage 234 is provided with an electromagnetic directional control valve 236, which connects the brake cylinder 235 to the master cylinder 233.
To a pressure increasing state for communicating with the reservoir 238, and a depressurizing state for communicating with the reservoir 238, and a holding state with which neither is communicated. The brake fluid discharged from the brake cylinder 235 to the reservoir 238 is pumped up by the pump 240 and returned from the pump passage 242 to the fluid passage 232. Further, the second liquid chamber 218 is provided with the port 244 and the pilot passage 246 so that the electromagnetic directional control valve 2 of the liquid passage 234 is provided.
It is connected to a portion of the brake cylinder 235 side of 36.

In this braking system, during normal braking, the electromagnetic directional control valve 236 is in the pressure increasing state shown in the figure,
By depressing the brake pedal 248, the master cylinder 2
The hydraulic pressure generated in the pressurizing chamber 33 is supplied to the brake cylinder 235 via the liquid passage 232, the first liquid chamber 216, the small through hole 220, the large through hole 222, and the liquid passage 234, and the rotation of the wheels is suppressed. . In this case, the master cylinder pressure is supplied to the brake cylinder 235 and is also supplied to the second liquid chamber 218 by the pilot passage 246. Therefore, the valve element 212 and the control piston 214 do not move forward, and the brake fluid is entirely discharged. It is supplied to the brake cylinder 235 at a large flow rate through the small through hole 220 and the large through hole 222.

When the wheel slip ratio exceeds the appropriate range, the electromagnetic directional control valve 236 is switched to the depressurized state, the brake fluid is discharged from the brake cylinder 235 to the reservoir 238, the brake cylinder pressure is reduced, and the wheel The slip ratio of is restored. Further, at this time, the hydraulic pressure in the second liquid chamber 218 also decreases, so that the valve element 212 and the control piston 214 move forward against the biasing force of the spring 226.

Therefore, first, the large through hole 222 is formed in the annular groove 2.
24, and then a part of the small through-hole 220 is disengaged from the annular groove 224, the flow of the brake fluid is throttled, and then the electromagnetic directional control valve 236 is switched to the pressure increasing state. The flow rate of the brake fluid supplied from the master cylinder 233 to the brake cylinder 235 is smaller than that during normal braking, and the brake cylinder pressure is gradually increased.

At this time, the brake fluid is the brake cylinder 2
35, and also to the second liquid chamber 218. Therefore, the fluid pressure in the second fluid chamber 218 increases, the valve element 212 and the control piston 214 retract, and the annular groove 22
The number of small through-holes 220 communicating with 4 increases. The load characteristic of the spring 226 is set such that this increase corresponds to the decrease in the hydraulic pressure difference between the first liquid chamber 216 and the second liquid chamber 218, that is, the hydraulic pressure difference between the master cylinder 233 and the brake cylinder 235. , Brake cylinder 23
The flow rate of the brake fluid supplied to 5 is kept almost constant,
The brake cylinder pressure is gradually increased with an almost constant gradient. However, this hydraulic pressure control device 200 has a problem that air accumulates in the second liquid chamber 218. This is because the brake fluid enters and leaves the second fluid chamber 218 by one port.

Therefore, the applicant of the present invention, as shown in FIG. 12, changes the flow rate of the brake fluid supplied to the brake cylinder into two stages, large and small, to thereby bring the brake cylinder pressure into a rapidly increasing state and a slowly increasing state. A prototype of a fluid pressure control device 260 that can be switched to, and in which air does not accumulate is manufactured. This hydraulic pressure control device 260 is similar to the hydraulic pressure control device 200 in that the valve element 264 and the control piston 266 integrally formed with each other in the housing 262 are fitted to each other so that the first hydraulic chamber 268 and the second hydraulic chamber 268 are provided. The liquid chamber 270 is formed, and the valve 264 and the control piston 266 are urged by the spring 272 in the backward direction.

The port 274 and the liquid passage 276 are connected to the pressurizing chamber of the master cylinder 278, and the port 2
80, the brake fluid is connected to the brake cylinder 284 by the fluid passage 282, and the flow of the brake fluid from the port 274 to the port 280 is generated by a plurality of small through holes 286 formed in the peripheral wall of the valve element 264 and one large through hole. Hole 288
However, it is squeezed by coming out of the annular groove 290. Further, the second liquid chamber 270 includes the port 294 and the liquid passage 29.
6 is connected to the reservoir 298, and the liquid passage 296 is provided with an electromagnetic opening / closing valve 300. The second liquid chamber 270 is also connected to the liquid passage 282 by the port 302 and the pilot passage 304.

In this hydraulic pressure control device 260, the electromagnetic opening / closing valve 300 is closed during normal braking, and when the brake pedal 306 is depressed, like the hydraulic pressure control device 200, all the through holes 288, 286 communicates with the annular groove 290, and a large amount of brake fluid is supplied to the brake cylinder 284. During the anti-skid control, by opening the electromagnetic opening / closing valve 300, the brake fluid in the brake cylinder 284 is discharged to the reservoir 298 via the second fluid chamber 270, the brake cylinder pressure is reduced, and the valve element 264 and the control are performed. The piston 266 advances and the large through hole 288 and some small through holes 286 are disengaged from the annular groove 290, and the flow rate of the brake fluid supplied to the brake cylinder 284 is reduced.

Therefore, when the electromagnetic on-off valve 300 is next closed to increase the brake cylinder pressure, the flow of the brake fluid is throttled and supplied to the brake cylinder 284, and the brake cylinder pressure gradually increases. In this hydraulic pressure control device 260, since the brake fluid to the second fluid chamber 270 flows in and out through the two ports 294 and 302, the air in the second fluid chamber 270 is discharged to the reservoir 238 together with the flow of the brake fluid. , Don't collect.

[0014]

However, in the hydraulic pressure control device 260, the spring 272 is added to the hydraulic pressure difference between the first hydraulic chamber 268 and the second hydraulic chamber 270, that is, the difference between the master cylinder pressure and the brake cylinder pressure. However, there is a problem in that either the braking effectiveness is delayed during normal braking or the deficient slow pressure increase range during anti-skid control is insufficient.

Large and small through holes 286 and 288 are provided in the passage for supplying the brake fluid from the master cylinder 278 to the brake cylinder 284. Even if all of them are communicated with the annular groove 290, the throttle action is to some extent. Is inevitable. If the preload of the spring 272 is small, when the brake pedal 306 is depressed during normal braking, the valve 264 and the control piston 266 move forward due to the difference in hydraulic pressure between the first liquid chamber 268 and the second liquid chamber 270. The through hole 288 and some small through holes 286 are disengaged from the annular groove 290, and the flow of the brake fluid is throttled from the beginning of braking. As a result, as shown in FIG. Occurs.

On the other hand, if the preload of the spring 272 is increased, the first liquid chamber 26 required for compression of the spring is increased.
8 and the second hydraulic chamber 270 have a large hydraulic pressure difference, and the valve element 264 and the control piston 266 do not move forward during normal braking, so that the flow of brake fluid is not throttled at the beginning of braking and a delay in braking effectiveness occurs. There is no such thing. However, since the hydraulic pressure difference between the first liquid chamber 268 and the second liquid chamber 270 required to move the valve element 264 and the control piston 266 forward is large, when the pressure is slowly increased, as shown in FIG. The valve 264 and the control piston 266 are moved to the retracted end position by the spring 272 while the pressure is still relatively low and the difference from the master cylinder pressure is large, and all the small through holes 286 and the large through holes 288 are moved.
Is communicated with the annular groove 290, and the flow rate becomes large, so that the pressure gradually changes from a rapid pressure increase to an abrupt pressure increase, and the pressure increase range becomes insufficient. This problem,
The same occurs not only in the anti-skid type hydraulic brake device but also in a device provided with a hydraulic pressure control device similar to the hydraulic pressure control device 260. SUMMARY OF THE INVENTION It is an object of the present invention to provide a hydraulic pressure control device capable of ensuring a sufficient gradual pressure increase range without causing a delay in the increase of the hydraulic pressure of a hydraulic pressure supply target device. is there.

[0017]

In order to solve the above-mentioned problems, a hydraulic control device according to the present invention has (a) a valve hole inside and communicates with each valve hole. An apparatus main body having a high pressure port, an output pressure port and a low pressure port connected to a source, a device to be supplied with hydraulic pressure and a reservoir, and (b) an open state provided between the low pressure port and the reservoir for communicating the two. An on-off valve that can be switched to a closed state that shuts off, and (c) is fitted in a valve hole so as to be liquid-tight and slidable, and is constantly connected to a high-pressure port between its both ends and the device body. A valve that forms a high pressure chamber that continues to communicate and a control pressure chamber that continues to communicate with the low pressure port but whose internal hydraulic pressure is changed by opening and closing the on-off valve; and (d) retract the valve to the high pressure chamber side. A first spring biasing to the end position, and (e) The valve has a spring constant larger than that of one spring, and when the valve element advances from the retreat end position to the advancing end position on the control pressure chamber side, the valve advances from an intermediate position intermediate between those retracting end position and advancing end position. A state in which the second spring acts on the child to bias the valve in the backward direction, and (1) the valve is at the backward end position between the valve and the apparatus body. Is in the first state where the output pressure port is cut off from the low pressure port and communicates with the high pressure port, and when the valve is advanced to the intermediate position the second state where the output pressure port is cut off from the high pressure port and communicated with the low pressure port (2) When the valve is between the intermediate position and the backward end position, the directional controller connects the high pressure port to the output pressure port when the valve is at the backward end position. Smaller than flow path area The high pressure port and the control pressure chamber are communicated with each other by the throttle passage having a passage area, and the flow passage area is gradually increased at least while the valve element is retracting from the forward end position to the intermediate position, so that the high pressure port and the control pressure chamber A variable throttle section is formed to keep the flow rate of the hydraulic fluid from the former to the latter substantially constant regardless of the difference in hydraulic pressure.

[0018]

When the hydraulic pressure control device configured as described above does not perform hydraulic pressure control, the on-off valve is closed, the valve element is at the backward end position, and the direction control unit is in the first state. .
Therefore, when increasing the hydraulic pressure of the hydraulic pressure control device,
The hydraulic pressure of the hydraulic pressure source is supplied to the hydraulic pressure control device via the high pressure port and the output pressure port. Further, at this time, since the control pressure chamber is always communicated with the high pressure port by the throttle passage, its hydraulic pressure rises together with the hydraulic pressure of the high pressure chamber, the valve element does not move, and it is maintained at the backward end position, The hydraulic fluid is supplied to the hydraulic pressure supply target device at a large flow rate without being throttled through the high pressure port and the output pressure port.

When the hydraulic pressure of the device to be supplied with hydraulic pressure is reduced, the on-off valve is opened, the control pressure chamber is made to communicate with the reservoir, and the hydraulic pressure of the control pressure chamber is reduced. Therefore, the hydraulic pressure in the high-pressure chamber becomes higher than that in the control pressure chamber, the valve moves forward against the urging force of the first spring, and when the intermediate position is reached, the direction control unit switches to the second state and the output pressure The port is cut off from the high pressure port and communicated with the low pressure port,
The hydraulic fluid of the hydraulic pressure supply target device is discharged to the reservoir through the low pressure port and the control pressure chamber, and the hydraulic pressure is reduced. Since it is sufficient to resist the biasing force of the first spring until the valve element moves from the retracted end position to the intermediate position, the directional control unit is quickly switched from the first state to the second state.
On the other hand, when the valve element further moves from the intermediate position to the forward end position, it is necessary to resist the urging force of the second spring, and therefore the valve element increases as the hydraulic pressure difference between the high pressure chamber and the control pressure chamber increases. Moving. Further, the flow passage area of the throttle passage decreases as the valve advances.

When the hydraulic pressure of the hydraulic pressure supply target device is increased from this state, the opening / closing valve is closed. Therefore, the hydraulic pressure in the control pressure chamber is gradually increased by the hydraulic fluid supplied from the high pressure port through the throttle passage to the control pressure chamber, and at the same time, the fluid communicated with the control pressure chamber through the low pressure port and the output pressure port. The hydraulic pressure of the pressure target device is gradually increased. The valve moves backward due to the increase in the hydraulic pressure in the control pressure chamber, but at least while the valve moves backward from the forward end position to the intermediate position, the flow passage area of the throttle passage gradually increases, and the high pressure port and the control pressure chamber are Regardless of the hydraulic pressure difference, the flow rate of the hydraulic fluid flowing from the high pressure port to the control pressure chamber is maintained substantially constant, so that the hydraulic pressure of the hydraulic pressure supply target device is gradually increased with a substantially constant gradient.

When the valve moves backward from the forward end position to the intermediate position, the spring acting on the valve changes from the second spring to the first spring having a small spring constant, and the valve moves from the intermediate position to the backward end position. At this time, the direction control unit switches from the second state to the first state, the output pressure port is cut off from communication with the low pressure port, and the output pressure port is connected to the high pressure port to restrict the working fluid to the hydraulic pressure supply target device. It returns to the state where it is supplied without receiving it.

[0022]

As described above, according to the present invention, the direction control unit is provided in the hydraulic pressure control device so that the hydraulic fluid is supplied to the device to which the hydraulic pressure is supplied without being throttled, and the hydraulic fluid is supplied after being throttled. By switching to the state
There is no delay in boosting when the equipment to be supplied with hydraulic pressure rapidly increases, and the spring constant of the spring that acts on the valve element changes between direction control and slow pressure boost control, allowing a sufficient slow pressure boost range. Can be secured.

When only the spring having a large spring constant is acted on the valve element, the expansion and contraction stroke of the spring with respect to the change in the hydraulic pressure difference between the high pressure chamber and the control pressure chamber is short, and the high pressure chamber and the control pressure are started from the start of the slow pressure increase. Since the amount of movement of the valve that can be obtained until the hydraulic pressure difference with the chamber disappears is short, if the direction control unit is to be switched, in order to secure the amount of movement of the valve for switching, control with the high pressure chamber is required. The direction control unit must switch from the second state to the first state when the pressure difference between the pressure chamber and the pressure chamber is large, and the slow pressure increase range is insufficient. On the other hand, if a spring with a small spring constant acts on the valve element when the direction control unit is switched, the hydraulic pressure in the control pressure chamber increases, and the hydraulic pressure difference between the high pressure port and the spring is reduced. A large expansion / contraction stroke can be obtained, and a movement amount for changing the direction can be secured in the valve element. Therefore, the hydraulic pressure in the control pressure chamber increases, and the second spring acts on the valve element until the hydraulic pressure difference between the high pressure port and the control pressure chamber becomes small, so that the slow pressure increase can be performed for a long time.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a hydraulic pressure control device of a reflux type anti-skid type hydraulic brake device for a four-wheeled vehicle will be described in detail with reference to the drawings. In FIG. 1, 10 is a brake pedal. Brake pedal 10
With the depression of, the hydraulic pressure is generated in the pressurizing chamber of the master cylinder 12 as the hydraulic pressure source, and is supplied to the brake cylinder 20 of the brake 18 provided on the wheel 16 by the liquid passage 14 to suppress the rotation of the wheel 16. . The brake 18 is a hydraulic pressure supply target device. Note that only one wheel 16 is shown in the drawing.

In this brake device, the four wheels 16 are individually anti-skid controlled. for that reason,
Brake cylinder 20 of each wheel 16 and master cylinder 1
A hydraulic pressure control device 24 is provided between the hydraulic pressure control device 2 and the hydraulic pressure control device 2, so that the hydraulic passage 14 is divided into a master cylinder side passage 26 on the master cylinder 12 side and a brake cylinder side passage 28 on the brake cylinder 20 side. .

In the fitting hole 32 formed in the housing 30 of the hydraulic control device 24, the first spring receiver 34, the block 36 and the supporting member 38 are fixed in a fitted state in series and together with the housing 30. It constitutes the device body.
In the block 36, a large-diameter hole 40 opening to the first spring receiver 34 side, and a spool hole 42 as a valve hole opening to the bottom surface 41 of the large-diameter hole 40 and the end surface on the supporting member 38 side are concentrically formed. A spool 44 as a valve is fitted in the spool hole 42 so as to be substantially liquid-tight and slidable.

The block 36 is also formed with a high-pressure port 48, which opens in the spool hole 42 and extends in the radial direction, at a position corresponding to the longitudinal middle portion of the spool hole 42. An end of the high-pressure port 48 on the spool hole 42 side is connected to an annular groove 50 opening in the spool hole 42, and an end of the high-pressure port 48 on the housing 30 side is connected to the high-pressure connection passage 52 and the master cylinder side passage formed in the housing 30. The pressure chamber 26 of the master cylinder 12 is communicated with the reference numeral 26.
The high pressure port 48 is also connected to a high pressure chamber 56 formed on the support member 38 side of the spool 44 by an axial passage 54 formed in the block 36.
6 is communicated with the spool hole 42 by a connection passage 58.

Further, the block 36 has a connection passage 58.
An output pressure port 62 that opens in the spool hole 42 and extends in the radial direction is formed at a position closer to the high pressure port 48, and the brake cylinder 2 is formed by the output pressure connection passage 64 and the brake cylinder side passage 28 formed in the housing 30.
It is connected to 0. Further, between the output pressure port 62 and the high pressure port 48, a low pressure port 68 that opens in the spool hole 42 and extends in the radial direction is formed, and is formed by the axial passage 70 by the spool hole 42 and the large diameter hole 40. The control pressure chamber 72 is communicated with the control pressure chamber 72.

The low pressure port 68 is connected to a reservoir 78 by a low pressure connection passage 74 formed inside the housing 30 and a reservoir passage 76 provided outside the housing 30. A solenoid valve 8 is provided in the middle of the low pressure connection passage 74.
0 is provided, and the control pressure chamber 72 is switched between a state in which it communicates with the reservoir 78 and a state in which it does not communicate by opening and closing the electromagnetic on-off valve 80. The brake fluid discharged into the reservoir 78 is pumped up by the pump 82 and returned to the master cylinder side passage 26.

A second spring receiver 86 is provided in the control pressure chamber 72.
Is slidably fitted, and the spool 44 is biased to the retracted end position on the high pressure chamber 56 side by a first spring 88 arranged between the spool 44 and the second spring receiver 86. The second spring receiver 86 is biased toward the spool 44 by a second spring 90 arranged between the second spring receiver 86 and the first spring receiver 34. The second spring 90 has a larger spring constant than the first spring 88, but its bias is
The second spring receiver 86 is regulated by coming into contact with the bottom surface 41 of the large diameter hole 40, and in this state, the spool 44 does not receive the biasing force of the second spring 90 and the first spring 88.
Is urged by and is separated from the second spring receiver 86 by a predetermined distance.

At the rear end of the spool 44, the spool hole 4
An annular groove 96 that opens at 2 is formed. The annular groove 96 is in the first state where the output pressure port 62 is cut off from the low pressure port 68 and communicates with the high pressure port 48 in a state where the spool 44 is located at the retracted end where it abuts the support member 38. In the state where the output pressure port 62 is advanced to the intermediate position on the retracted end side for a small distance from the contact with the second spring receiver 86, the output pressure port 62 is shut off from the high pressure port 48 and is connected to the low pressure port 68. Is formed in. The direction control unit 9 includes a portion of the spool 44 provided with the annular groove 96 and a portion of the block 36 provided with the connection passage 58, the output pressure port 62, the low pressure port 68, and the like.
8 is composed.

Further, as shown in FIG. 2, the spool 44 is provided with a throttle groove 100 which is open at the tip end surface and the outer peripheral surface of the spool 44 and extends in the longitudinal direction.
0 and the spool hole 42 form a throttle passage 102. As shown in FIGS. 3 and 4, the throttle groove 100 has a fan-shaped cross-sectional shape, and is formed so that the cross-sectional area gradually decreases while maintaining the similarity of the cross-sectional shape toward the rear end of the spool. Is always formed so as to communicate with the annular groove 50 when moving between the backward end position and the forward end position.

Accordingly, the throttle passage 102 has the spool 4
When 4 is in the retracted end position, the control pressure chamber 72 and the high pressure port 48 are communicated with each other in a flow passage area smaller than the flow passage area for communicating the high pressure port 48 of the annular groove 96 with the output pressure port 62, and While the spool 44 retreats from the forward end position to the backward end position, the flow passage area gradually increases, regardless of the hydraulic pressure difference between the high pressure port 48 and the control pressure chamber 72, regardless of the high pressure port 48 to the control pressure chamber 72. Keep the flow rate of brake fluid to the pump at an almost constant level. The portion that forms the throttle passage 102 between the spool 44 and the block 36 is the variable throttle portion 10.
4 is composed.

The opening / closing of the solenoid opening / closing valve 80 is controlled by the control device 1
Controlled by 10. The control device 110 includes wheels 1
The detection result of the rotation sensor 112 for detecting the rotation speed of the No. 6 is supplied, and the control device 110 calculates the wheel speed, the vehicle body speed, the wheel deceleration and the slip ratio based on the detection result, and the electromagnetic opening / closing valve 80 Switch.

In the hydraulic brake device constructed as described above, when the brake is not applied, the spool 44 is at the backward end position as shown in FIG. 5, the direction controller 98 is in the first state, and the brake cylinder 20 is It communicates with the master cylinder 12. Further, the electromagnetic opening / closing valve 80 is closed, and the second spring receiver 86 is in contact with the bottom surface 41.

In this state, if the brake pedal 10 is depressed to suppress the rotation of the wheels 16, the master cylinder 1
The hydraulic pressure generated in the second pressurizing chamber is the master cylinder side passage 2
6, high pressure connection passage 52, high pressure port 48, axial passage 5
4 is supplied to the high pressure chamber 56, and
From the connecting passage 58, the annular groove 96, the output pressure port 62,
Output pressure connection passage 64 and brake cylinder side passage 28
And is supplied to the brake cylinder 20 through the above, and the rotation of the wheels 16 is suppressed. At this time, the hydraulic pressure of the high pressure port 48 is also transmitted to the control pressure chamber 72 via the annular groove 50 and the throttle passage 102. Therefore, the hydraulic pressures of the high pressure chamber 56 and the control pressure chamber 72 are equal, and the spool 44 is The brake cylinder 20 is kept in a state of communicating with the master cylinder 12 through the high pressure port 48 without advancing, and the brake is applied without delay.

When the brake cylinder pressure is too high in relation to the friction coefficient of the road surface and the slip ratio of the wheels exceeds the proper range, the control device 110 detects the fact based on the output signal of the rotation sensor 112. , Open the solenoid on-off valve 80. As a result, the control pressure chamber 72 communicates with the reservoir 78, and the hydraulic pressure in the control pressure chamber 72 decreases, so that the spool 4
A hydraulic pressure difference is generated before and after 4, and the spool 44 advances.

Therefore, first, as shown in FIG. 6, the output pressure port 62 is closed, the brake cylinder 20 is cut off from the communication with the master cylinder 12, and the brake fluid in the control pressure chamber 72 further flows out to cause spooling. 44 moves forward, and the output pressure port 62 is changed to the low pressure port 6 as shown in FIG.
8, the brake fluid flows from the brake cylinder 20 to the reservoir 78, and the brake cylinder pressure is reduced. In this state, the spool 44 is in contact with the second spring receiver 86, and if the hydraulic pressure in the control pressure chamber 72 further decreases thereafter, the spool 44 will be urged by the second spring 90 as shown in FIG. Proceed against and move to the second spring receiver 8
4 is separated from the bottom surface 41.

When the slip ratio of the wheel is recovered due to the decrease of the brake cylinder pressure, the electromagnetic opening / closing valve 80 is closed to increase the brake cylinder pressure, and the outflow of the brake fluid from the brake cylinder 20 and the control pressure chamber 72 is stopped. To be Therefore, the hydraulic pressure in the control pressure chamber 72 is equal to that of the annular groove 50.
The brake fluid flows from the master cylinder 12 through the throttle passage 102 and increases, and the brake cylinder pressure rises.

When the spool 44 is advanced, the portion of the throttle groove 100 having a small cross-sectional area constitutes the throttle passage 102 together with the spool hole 42, and the brake fluid supplied to the control pressure chamber 72 is supplied by the throttle passage 102. The brake cylinder pressure gradually increases as the throttle cylinder is squeezed to a small amount. When the hydraulic pressure in the control pressure chamber 72 increases, the spool 44 retracts, and the cross-sectional area of the portion of the throttle groove 100 that constitutes the throttle passage 102 gradually increases. Since the flow passage area increases as the brake cylinder pressure increases, the flow rate of the brake fluid supplied to the control pressure chamber 72 becomes substantially constant regardless of the hydraulic pressure difference between the high pressure port 48 and the control pressure chamber 72. Hold, the brake cylinder pressure increases linearly as shown in the graph of FIG.

As the brake cylinder pressure increases, the second spring receiver 86 and the spool 44 retreat, and the second spring receiver 8 moves.
After 6 comes into contact with the bottom surface 41, the spool 44 is biased by the first spring 88, retracts as the hydraulic pressure in the control pressure chamber 72 increases, and the direction control section 98 switches to the first state. Brake fluid is supplied from the master cylinder 12 to the brake cylinder 20 via the high pressure port 48. The spring constant of the first spring 88 is the second spring 9
Since the spring constant is smaller than 0, the amount of change in the hydraulic pressure difference between the high pressure port 48 and the control pressure chamber 72 required for expansion and contraction is small,
If only the first spring 88 acts during the retreat of the spool 44, the hydraulic pressure difference between the high pressure port 48 and the control pressure chamber 72, that is, the hydraulic pressure difference between the master cylinder 12 and the brake cylinder 20 becomes small. The second spring 90 can act on the spool 44 up to
As shown in FIG. 9, a wide pressure increasing range can be secured, and the spool 44 can be moved by a distance required for the direction control unit 98 to switch from the second state to the first state.

Another embodiment of the present invention is shown in FIG. In this embodiment, a spool 120 as a valve and a spool 12
The variable throttle portion 123 is configured by the variable throttle portion forming member 122 fitted to 0. In this embodiment, the spool 120 is slidably fitted in a spool hole 126 formed in the apparatus main body 124, and a high pressure chamber 128 formed on one side of the spool 120 is provided with a connection passage 130, a high pressure port 132 and a master. The cylinder side passage 134 communicates with the pressurizing chamber of the master cylinder 136 as a hydraulic pressure source.

Further, the high pressure port 132 of the apparatus main body 124
An output pressure port 140 is formed on the front side, and the brake cylinder 144 is formed by the brake cylinder side passage 142.
It is connected to the. A low pressure port 146 is formed further on the front side of the apparatus main body 124, and is connected to a control pressure chamber 150 formed on the other side of the spool 120 by a connection passage 148. The control pressure chamber 150 has a spool hole 126.
And a large diameter hole 151 formed following the spool hole 126.
It is composed of and. The low pressure port 146 is communicated with the reservoir 154 by the reservoir passage 152, and the reservoir passage 152 is provided with an electromagnetic opening / closing valve 156. The brake fluid discharged to the reservoir 154 is pumped by the pump 158 into the master cylinder side passage 134.
Returned to.

The spool 120 has a cylindrical shape, and the variable throttle portion forming member 122 is fitted inside the spool 120 so as to be relatively movable in the axial direction, and the spool 162 is attached in the backward direction (forward direction of the spool 120). It is energized. The variable throttle portion forming member 122 includes a sliding portion 166 fitted to the spool 120, a plurality of liquid passages 168 formed by axially penetrating an outer peripheral portion of the sliding portion 166, and a sliding portion 16.
6 and a needle valve element 170 which is extended in the backward direction of the spool 120 and whose diameter is gradually reduced toward the tip. The needle valve element 170 is inserted into an orifice 172 projecting from the inner peripheral surface of the spool 120. Has been done. The variable throttle portion 123 is constituted by the needle valve element 170 and the orifice 172.

The spool 120 has a spring 1 disposed between the spool 120 and a support member 174 provided upright in the large-diameter hole 151.
The shoulder surface 17 of the spool hole 126 is biased in the backward direction by 76 (which corresponds to the first spring in the claims) in the backward direction during non-braking and during normal braking.
It is located at the retracted end position where it abuts on 8. Also,
An annular groove 180 is formed on the outer peripheral surface of the spool 120. The spool 120 is provided with a portion having the annular groove 180, a high pressure port 132, an output pressure port 140, a low pressure port 146, etc. of the apparatus main body 124. The part and the part constitute the direction control unit 182.

Large diameter hole 15 forming the control pressure chamber 150
A spring 184 (which corresponds to the second spring in the claims) is arranged in the first unit.
The spring 184 has a spring constant larger than that of the spring 176, and its urging force is regulated by the spring receiver 186 slidably fitted in the large diameter hole 151 coming into contact with the bottom surface 188 of the large diameter hole 151, and thus the spool 120. Is biased by a spring 176 and is always separated from the spring receiver 186.

In this embodiment, the electromagnetic on-off valve 156 is closed during normal braking, and the hydraulic pressure generated in the pressurizing chamber of the master cylinder 136 is the master cylinder side passage 13.
4, is supplied to the brake cylinder 144 via the high pressure port 132, the annular groove 180, the output pressure port 140 and the brake cylinder side passage 142. Brake pedal 19
When 0 is stepped on, the brake cylinder 144 is moved along this path.
Brake fluid is supplied to the variable throttle portion 123
And the high pressure chamber 12 via the liquid passage 168 to the control pressure chamber 150.
The hydraulic pressure of 8 is supplied, and the spool 120 does not move.

If the solenoid on-off valve 156 is opened to reduce the brake cylinder pressure during anti-skid control,
When the hydraulic pressure in the control pressure chamber 150 is reduced, the spool 120 moves forward, the output pressure port 140 is blocked from communicating with the high pressure port 132, and the low pressure port 146 is cut off.
And the brake cylinder pressure is reduced. At this time, the variable throttle portion forming member 122 is urged by the spring 162 and does not move, and the spool 120
Compresses the spring 176 to form the variable throttle portion forming member 12
Go forward with 2. Then, when the spool 120 comes into contact with the spring receiver 186 and compresses the spring 184 to move forward, the support member 174 causes the variable throttle portion forming member 122.
And the variable throttle portion forming member 122 contacts the spool 120.
Prevent them from moving forward with. Therefore, thereafter, the flow passage area of the variable throttle portion 123 gradually decreases.

From this state, if the electromagnetic opening / closing valve 156 is closed to increase the brake cylinder pressure, the high pressure chamber 1
The hydraulic fluid in the control pressure chamber 150 rises due to the brake fluid supplied from 28 through the variable throttle portion 123 and the fluid passage 168, and the brake cylinder pressure rises. The spool 120 retracts due to the increase in the hydraulic pressure of the control pressure chamber 150, and accordingly, the cross-sectional area of the portion of the variable throttle portion forming member 122 located in the orifice 172 of the needle valve element 170 gradually decreases, and the variable throttle portion 123 has a smaller sectional area. Since the flow passage area gradually increases, regardless of the hydraulic pressure difference between the high pressure port 132 and the control pressure chamber 150,
The flow rate of the brake fluid flowing into the brake cylinder 144 via the control pressure chamber 150 is kept substantially constant, and the brake cylinder pressure gradually increases with a substantially constant gradient.

The spool 120 retracts and the spring bearing 186
When the bottom surface 188 contacts with the bottom surface 188, the spool 120 is biased only by the spring 176 and retracts as the hydraulic pressure difference decreases, and the annular groove 180 causes the output pressure port 140 to move.
From the state where the low pressure port 146 is communicated with the high pressure port 1
Then, the brake fluid is supplied to the brake cylinder 144 without being throttled.

In each of the above embodiments, the on-off valve that allows and blocks the communication between the low pressure ports 68 and 146 and the reservoirs 78 and 154 is an electromagnetic on-off valve. It may be a type of on-off valve.

In each of the above embodiments, the case where the present invention is applied to the reflux type anti-skid type hydraulic brake device has been described as an example, but the present invention is not limited to the hydraulic pressure control of the acceleration slip control device and the like. It can also be applied to a device.

In addition, the present invention can be implemented in various modified and improved modes based on the knowledge of those skilled in the art without departing from the scope of the claims.

[Brief description of drawings]

FIG. 1 is a front sectional view showing a reflux type anti-skid type hydraulic brake device equipped with a hydraulic pressure control device according to an embodiment of the present invention.

FIG. 2 is an enlarged front sectional view showing a variable throttle portion of the hydraulic control device.

FIG. 3 is a perspective view showing a portion of a spool of the hydraulic control device in which a throttle groove is formed.

4 is a sectional view taken along line IV-IV in FIG.

FIG. 5 is a diagram showing an operating state of the hydraulic control device during normal braking.

FIG. 6 is a diagram showing an initial state of pressure reduction during anti-skid control of the hydraulic control device.

FIG. 7 is a diagram showing a depressurized state during anti-skid control of the hydraulic control device.

FIG. 8 is a diagram showing a depressurized state and a gradual pressure increase starting state during anti-skid control of the hydraulic pressure control device.

FIG. 9 is a graph showing the relationship between time, brake cylinder pressure, and master cylinder pressure in the hydraulic brake device.

FIG. 10 is a front sectional view showing a reflux type anti-skid type hydraulic brake device including a hydraulic pressure control device according to another embodiment of the present invention.

FIG. 11 is a front sectional view showing a reflux type anti-skid type hydraulic brake device including a conventional hydraulic pressure control device.

FIG. 12 is a front sectional view showing a reflux type anti-skid type hydraulic brake device equipped with a hydraulic pressure control device that was prototyped prior to completion of the present invention.

13 is a graph showing the relationship between time, brake cylinder pressure, and master cylinder pressure when the spring constant of the springs forming the hydraulic control device shown in FIG. 12 is reduced.

14 is a graph showing the relationship between time, brake cylinder pressure, and master cylinder pressure when the spring constant of the springs of the hydraulic control device shown in FIG. 12 is increased.

[Explanation of symbols]

 12 master cylinder 18 brake 24 hydraulic control device 30 housing 34 first spring bearing 36 block 38 support member 42 spool hole 44 spool 48 high pressure port 56 high pressure chamber 62 output pressure port 68 low pressure port 78 reservoir 80 electromagnetic opening / closing valve 88 first spring 90 Second Spring 98 Direction Control Section 102 Throttling Passage 104 Variable Throttling Section 120 Spool 122 Variable Throttling Section Forming Member 123 Variable Throttling Section 124 Device Main Body 126 Spool Hole 128 High Pressure Chamber 132 High Pressure Port 136 Master Cylinder 140 Output Pressure Port 146 Low Pressure Port 150 Control pressure chamber 154 Reservoir 170 Needle valve 172 Orifice 176, 184 Spring

Claims (1)

[Claims] 1. A hydraulic pressure control device which is provided between a hydraulic pressure source, a hydraulic pressure supply target device, and a reservoir to control the hydraulic pressure of the hydraulic pressure supply target device, and which has a valve hole inside, Provided between the device main body having a high-pressure port, an output pressure port and a low-pressure port, which communicate with the valve holes and are connected to the hydraulic pressure source, the device to which the hydraulic pressure is supplied, and the reservoir, and between the low-pressure port and the reservoir. And an open / close valve capable of switching between an open state for communicating the both and a closed state for shutting off the both, and a substantially liquid-tight and slidable fit in the valve hole, and between the both ends of itself and the apparatus main body. And a valve for forming a high pressure chamber that is always in communication with the high pressure port and a control pressure chamber that is always in communication with the low pressure port but whose internal hydraulic pressure is changed by opening and closing the on-off valve, and its valve. Move the child to the retracted end on the high pressure chamber side. A first spring biasing the first spring and a spring constant larger than that of the first spring, and when the valve element advances from the retracted end position to the advancing end position on the control pressure chamber side, the retracted end position and the advancing end position are advanced. A second spring that acts on the valve element from the state of advancing to an intermediate position intermediate between the end position and biases the valve element in the backward direction, and
Between the valve element and the main body of the apparatus, (1) in a state where the valve element is at the retracted end position, the output pressure port is in a first state of being cut off from the low pressure port and communicated with the high pressure port. In the state where the output pressure port is advanced to the intermediate position, the output pressure port is cut off from the high pressure port and is connected to the low pressure port. The direction control unit is switched to the second state, and (2) the valve is between the intermediate position and the backward end position. In the state, the directional control unit communicates the high pressure port with the control pressure chamber by the throttle passage having a flow passage area smaller than the flow passage area that allows the high pressure port to communicate with the output pressure port when the valve is at the backward end position. And at least while the valve is retracting from the forward end position to the intermediate position, the flow passage area gradually increases to operate from the former to the latter regardless of the hydraulic pressure difference between the high pressure port and the control pressure chamber. Hydraulic control apparatus characterized by the variable throttle portion is formed to maintain a substantially constant flow rate.