JPH0464903B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hydraulic pressure adjustment device for anti-skid brakes used in a vehicle brake system.

Conventionally, one of these types of devices includes a cutoff valve that is placed between a master cylinder and a wheel cylinder and can cut off communication between the two, and one end of the cutoff valve is movable and faces the cutoff valve so that it can be opened and closed. a volume chamber that is defined between one end of the plunger and the cutoff valve and communicates with the wheel cylinder and whose volume increases or decreases according to movement of the plunger; a variable pressure chamber that is partitioned and supplies and discharges pressure that urges the plunger in the opening direction of the shutoff valve against the pressure in the volume chamber; and a variable pressure chamber that sucks and pressurizes the hydraulic fluid discharged from the variable pressure chamber and discharges it. a pump capable of supplying pressurized working fluid to the variable pressure chamber; and a position provided between the pump and the variable pressure chamber to communicate the variable pressure chamber to the discharge side of the pump in response to an external command. A hydraulic pressure adjusting device for an anti-skid brake is known, which includes a switching valve device that switches between a position where the variable pressure chamber is communicated with the suction side of the pump, and a switching valve device that is switched to a position that communicates the variable pressure chamber with the suction side of the pump.

By the way, in such a device, the hydraulic system from the master cylinder to the wheel cylinder,
Since the hydraulic system, which is equipped with a pump and a switching valve device and supplies and discharges pressure to the transformation chamber, is separate and independent, the latter hydraulic system is equipped with a hydraulic fluid reservoir for the master cylinder. A hydraulic fluid reservoir must be provided to temporarily store the hydraulic fluid discharged from the variable pressure chamber to the suction side of the pump and release or reduce the pressure. These reservoirs are sized to be able to store hydraulic fluid with a certain amount of margin relative to the amount of fluid required for each system. For this reason, the conventional brake system has had the problem of increasing the size and weight of the entire brake system.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a hydraulic pressure adjustment device for an anti-skid brake that can downsize the entire brake device. According to the present invention, in the above configuration, an auxiliary passage is provided which branches from a discharge passage connecting the switching valve device and the suction side of the pump and is connected to the master cylinder side of the shutoff valve.
This is achieved by disposing a check valve whose forward direction is in the direction toward the master cylinder in the auxiliary passage.

Embodiments of the present invention will be described below with reference to the drawings.

In the figure, the anti-skid brake hydraulic pressure adjusting device of this embodiment is indicated as a whole by 1, and a stepped hole 3 extending from side to side is formed in the upper portion of a housing 2 thereof. The stepped hole 3 is composed of a small diameter hole part 4 and a large diameter hole part 5, and the small diameter hole part 4 communicates with a wheel cylinder connection port 6 at its left end via a passage 7 extending in the vertical direction. The opening at the left end of the large diameter hole 5 is closed by screwing a lid 8 fitted with a seal ring 9. A master cylinder connection port 10 and a lateral passage 11 are formed in the lid body 8 and communicate with the large diameter hole portion 5 of the stepped hole 3.

The large diameter hole 5 has a stepped shutoff valve main body 13.
A seal ring 14 is attached and fitted to the large diameter portion 15, and a stepped hole 18 extends in the axial direction.
It is equipped with A plurality of through holes 17 are formed in the small diameter portion 16 of the shutoff valve body 13, allowing communication between the large diameter portion 19 of the internal stepped hole 18 and the large diameter hole 5 of the housing 2.

In addition, the right end surface 18 of the large diameter portion 15 of the shutoff valve main body 13
1 has a groove 27 formed in the radial direction, and such a right end surface 181 is brought into contact with a step between the small diameter hole 4 and the large diameter hole 5. The shutoff valve main body 13 is tightly fixed between the right end of the lid 8 and the stepped portion by screwing the lid 8. A slope portion 20 is formed between the large diameter hole portion 19 and the medium diameter hole portion 21 in the stepped hole 18 in the shutoff valve body 13, and serves as a valve seat for the ball valve 25 as the valve element. A valve spring 26 is stretched between the ball valve 25 and the right end surface of the lid body 8, and urges the ball valve 25 to the right. Stepped hole 18
A shaft-shaped member 24 is inserted between the medium-diameter hole 21 and the small-diameter hole 22, and the enlarged diameter portion at the left end is slidable in the medium-diameter hole 21 and comes into contact with the ball valve 25. ing. In the normal state shown in the figure, the ball valve 25 is separated from the valve seat 20 by the shaft-like member 24, and the master cylinder connection port 10 side is connected to the shaft-like member 24.
A plurality of grooves 2 formed on the outer periphery of the left end increased diameter portion of 4.
3. Small diameter hole 22 and right end surface 1 of the shutoff valve body 13
It is communicated with the wheel cylinder connection port 6 side via a radial groove 27 formed in 81.

As described above, the shutoff valve 113 capable of blocking liquid movement from the master cylinder connection port 10 side to the wheel cylinder connection port 6 side is configured, and furthermore, the shaft-shaped member 24
By assembling the cutoff valve 113 into the cutoff valve main body 13, the cutoff valve 113 becomes one assembly.

A plunger 28 equipped with sealing members 29 and 30 is slidably fitted into a small diameter hole 4 of a stepped hole 3 extending left and right in the upper part of the housing 2.
The left end portion 31 is reduced in diameter to form the shaft-like member 24 described above.
A volume chamber 180 is formed between the shutoff valve body 13 and the plunger 28, and the volume can be changed by the movement of the plunger 28. A variable pressure chamber 33 is defined between the right end side of the plunger 28 and the end wall of the housing 2, and a spring 32 is tensioned in this chamber to bias the plunger 28 to the left.

Note that the spring force of the spring 32 is the same as that of the sealing members 29, 3.
The biasing force is light enough to overcome the sliding resistance between the plunger 28 and the small diameter hole 4 and move the plunger 28 to the left. Furthermore, the above-mentioned shaft-like member 24 has a length that separates the ball valve 25 and the valve seat 20 by a predetermined amount when the plunger 28 and the right side surface 181 of the shutoff valve main body 13 come into contact, in other words, a desired length. The right end surface 1 of the shutoff valve main body 13
The length is the sum of the length from 81 to the seating position of the ball valve 25.

A lateral passage 34 is formed that extends in the lateral direction and is perpendicular to and communicates with the vertical passage 12 that communicates with the master cylinder connection port 10 through a hole 17 formed in the small diameter portion 16 of the shutoff valve body 13. Stepped holes are formed in the horizontal direction in an aligned and continuous manner, and in order from the left are a small diameter hole section 35, a medium diameter hole section 36, and a large diameter hole section 3.
7, and the right end opening of the large-diameter hole 37 is closed by attaching the lid member 38 with the seal rings 39, 92 attached to the housing 2 by suitable means such as bolts (not shown). A sloped surface 99 is formed between the small diameter hole 35 and the lateral passage 34, and serves as a valve seat for the ball valve 40. It is seated on a sloped portion, that is, a valve seat 99.
Further, the left side small diameter portion of the communication member 71 is fitted with a seal ring 72 in the medium diameter hole portion 36.
The space inside the small diameter hole 35 between the left end face and the ball valve 40 is defined as a pump pressure chamber P. Hydraulic pressure from the master cylinder acts on the left side of the ball valve 40, and pressure from the pump pressure chamber P acts on the right side. The pump pressure chamber P is a vertical passage 4 extending downward.
2, which in turn communicates with a stepped hole including a valve hole 43. The lower end opening of this stepped hole is closed by screwing a lid 46 fitted with a seal ring 47. A hydraulic pump connection port 48 is formed in the lid body 46, and a valve seat 100 of the ball valve 44 is formed around the upper end opening. In the normal illustrated state, the ball valve 44 is seated on the valve seat 100 under the urging force of the valve spring 45. The hydraulic pump connection port 48 is connected to a discharge port of a hydraulic pump 49 via a conduit 51 and is also connected to an accumulator 50 . The accumulator 50 has a known structure and consists of a main body, a slidable piston provided in the main body, a spring, etc., and the pressure of the hydraulic fluid is determined by the hydraulic fluid capacity of the pressure accumulating chamber and the spring force of the spring. It is supplied to the pump pressure chamber P. hydraulic pump 1
9 is driven by the motor 52, but even when it is not driven, the accumulated pressure in the accumulator 50 at that time is supplied to the pump pressure chamber P and presses the ball valve 40 to the left.
The state shown in the figure can be achieved. A suction port of the hydraulic pump 49 communicates with a hydraulic fluid reservoir 53 via a conduit 54 .

The increased diameter portion formed in the middle portion of the communication member 71 is
It is supported by a contact plate 73 that is in contact with the step between the medium diameter hole 36 and the large diameter hole 37, and is in a fixed state.
The right small diameter portion is fitted with a seal ring 77 and fitted into the guide tube 80. A control piston 81 made of a magnetic material is also slidably fitted into the guide cylinder 80, and valve balls 82, 8 are provided at the center of both end faces of the control piston 81.
3 is fixed. The control piston 81 has a reduced diameter portion 84 near its left end, and grooves 85, 86 are formed on the circumferential surface on both sides of this portion. A coil 7 molded with synthetic resin 79 is provided on the outer periphery of the guide tube 80.
8 is wound around it, and an annular member 90 having seal rings 89 and 88 attached to the inner and outer circumferential parts is fitted. A switching valve device 110 is constituted by the coil 78, the control piston 81, the valve balls 82, 83, and the like. The contact plate 73, the communication member 71, the coil 78, the guide tube 80, and the annular member 90 are connected to the lid member 38 by fitting the lid member 38 into the large diameter hole 37.
and a step between the medium diameter hole 36 and the large diameter hole 37. As a result, a stable fixed state can be obtained.

A spring 87 is tensioned between the flange formed at the right end of the control piston 81 and the annular member 90, and biases the control piston 81 to the right to close the valve ball 83 in the normal state shown. Most of the member 38 is in contact with the opening of the throttle through hole 93 formed on the central axis. The through hole 93 communicates with hydraulic fluid discharge passages 94 and 95 also formed in the lid member 38, and further communicates with the reservoir 53 via a long lateral passage 70 formed in the housing 2, as will be described later.

On the other hand, a passage 74 is formed on the central axis of the above-mentioned communication member 71 facing the valve ball 82, the right end of which is a throttle passage 75, and the opening 76 functions as a valve seat and is normally closed. In the illustrated state, the valve ball 8
2 is far from this.

A plurality of grooves 91 are formed in the inner end wall of the lid member 38 in the radial direction.
is formed, and a communication chamber 101 defined by the lid member 38 and the annular member 90 is communicated with the above-mentioned variable pressure chamber 33 via a passage 102 formed in the housing 2. Therefore, in the normal illustrated state, the pump pressure chamber P to which the discharge port of the hydraulic pump 49 is connected via the conduit 51 and the connection port 48 is connected to the passage 74 of the communication member 71 and the outer circumference of the control piston 81. transformer chamber 3 through grooves 85, 86 and communication chamber 101.
It communicates with 3.

The housing 2 is further formed with a stepped hole aligned with and continuous with the vertical passage 12, the lower end opening of which is provided with a lid 64 fitted with seal rings 66, 67.
It is closed by the screw. A reservoir connection port 65 is formed in the lid body 64, and a passage 6 is connected to the reservoir connection port 65.
8 is formed, and a passage 69 that is perpendicular to and communicates with this passage 68 is also formed. This passage 6
9 communicates with the above-mentioned long lateral passage 70,
This passage 70, a portion of the passage 68 below the communication point with the passage 69, the passage 69, and the above-mentioned hydraulic fluid discharge passages 94 and 95 allow the switching valve device 11 to
0 and the hydraulic pump 49 side is configured. Further, the auxiliary passage consisting of the vertical passage 12, the small-diameter hole portion 98 of the stepped hole, and the portion of the passage 68 above the communication point with the passage 69 communicates with the above-mentioned discharge passage. This includes:
A check valve 111 is provided. That is, this check valve 111 includes a valve seat 103 formed at the upper end of the lid body 64, a ball valve 96 disposed in a small diameter hole 98, and a valve seat 103 to seat the ball valve 96 on the valve seat 103. Normally, the ball valve 96 is seated on the valve seat 103 as shown in the figure, and the direction from the above-mentioned discharge communication side to the master cylinder side is the forward direction.

Reservoir connection port 65 is connected to reservoir 53 via conduits 55 and 54. The reservoir 53 consists of a main body 56, a lid 57 that covers this internal space, and a piston 60 fitted with a seal ring 61 and slidable within the main body 56 and defining a reservoir chamber 59 and an air chamber 62. A through hole 58 is formed in the lid 57, through which the reservoir chamber 59 communicates with the reservoir connection port 65. Although the spring 63 can move the piston 60 to the right by overcoming the sliding resistance between the seal ring 61 and the inner wall of the main body, the spring force is sufficiently small.

The master cylinder connection port 10 is connected to the hydraulic pressure generation chamber of the master cylinder via a pipe line (not shown),
The wheel cylinder connection port 6 is connected to a wheel, for example, a wheel cylinder of one rear wheel, via a pipe (not shown). In this case, it is assumed that a device similar to the illustrated device is also connected to the wheel cylinder of the other rear wheel. Alternatively, the wheel cylinder connection port 6 may be commonly connected to the wheel cylinders of both rear wheels.

An output terminal of a control unit (not shown) is connected to the coil 78, and an output terminal of a wheel sensor for detecting the rotational speed of the rear wheel is connected to the input terminal of the control unit.
The output terminal of the pressure switch installed in the terminal is connected.

Although the embodiment of the present invention is configured as described above,
Next, this effect will be explained.

The electric motor 52 that drives the hydraulic pump 49 may be operated at all times when the vehicle is running, or may be operated at the same time as the brakes are applied, or as described later, when the coil 78 is energized. In any case, the hydraulic pressure applied to the variable pressure chamber 33 from the discharge port of the hydraulic pump 49 or the accumulator 50 through the pump connection hole 48 and various passages is
9 is normal, the hydraulic pressure is sufficiently higher than the hydraulic pressure from the master cylinder applied from the left end side of the plunger 28.

That is, in the illustrated state, the hydraulic pressure of the hydraulic pump 49 or the accumulator 50 is transmitted through the connection port 48 → pump pressure chamber P → the axial passage 74 of the communication member 71 → the grooves 85 and 86 on the outer periphery of the control piston 81 → the communication chamber. 1
01→groove 91→through hole 102 and is transmitted to the variable pressure chamber 33. Note that when the pressure in the pump pressure chamber P acting from above the ball valve 14 plus the spring force of the valve spring 45 reaches equilibrium with the pressure on the pump 49 and accumulator 50 sides, the ball valve 44 moves as shown in the figure. It is seated on the valve seat 100.

Now, when the brake pedal (not shown) is stepped on, hydraulic pressure is generated in the hydraulic pressure generation chamber of the master cylinder, and this is caused by the master cylinder connection port 10, the lateral passage 11, the large diameter hole 19 in the shutoff valve body 13, and the ball. It is transmitted to the wheel cylinder through the gap between the valve 25 and the valve seat 20, the groove 23 of the shaft member 24, the groove 27 on the end face of the shutoff valve body 13, the passage 7, and the wheel cylinder connection port 6. This applies the brakes to the wheels. At this time, hydraulic pressure from the master cylinder acts on the left side of the plunger 28, but the hydraulic pressure in the variable pressure chamber 33 acting on the right side of the plunger 28 is greater than that hydraulic pressure, so the plunger 28 cannot be moved to the right. It remained stopped. In addition, the shutoff valve body 1
3 and the plunger 28
Since the volume of 80 is sufficiently small at this time, the amount of liquid transferred from the master cylinder is reduced and the brake can be applied quickly.

The hydraulic pressure in the wheel cylinder of the wheel increases along with the hydraulic pressure in the master cylinder, but if the control unit (not shown) determines that the brake force exceeds the appropriate brake force, it will, for example, indicate that the slip rate of the wheel has exceeded a predetermined slip rate. If it is determined that there is a release signal, the control unit generates a release signal, which energizes the coil 78. This energization generates magnetic flux inside the coil 78, and the control piston 81
is moved to the left by the magnetic force against the spring force of the spring 87, the valve ball 82 seats on the valve seat 76, and the throttle passage 75 of the passage 74 is closed. The other valve ball 83
is separated from the opening of the throttle passage 93 of the lid member 38.

As described above, the pump pressure chamber P and the variable pressure chamber 33 are cut off, and the variable pressure chamber 33 and the reservoir 53 side are communicated with each other. Pressure fluid flows from the variable pressure chamber 33 to the passage 102 and the communication chamber 1
01, throttle passage 93, discharge passage 94, 95, 7
0, 69, 68 and conduits 55, 54 into the reservoir chamber 59 of the reservoir 53. Note that since the pressure liquid is discharged through the throttle passage 93, it is not discharged rapidly but gradually. Transformer room 3
3 decreases along with this, and when the force pushing the plunger 28 to the left becomes smaller than the pressure in the volume chamber 180 between the shutoff valve body 13 and the plunger 28, the plunger 28 moves to the right. start. Shaft member 2 that comes into contact with the left end surface of langeer 28
4 also begins to move to the right due to the spring force of the valve spring 26. When the ball valve 25 is moved by the valve lift amount from the illustrated position, the ball valve 25 is seated on the valve seat 20, and thereafter the master cylinder side and the wheel cylinder side are shut off. As the plunger 28 moves to the right, the volume chamber 180 between the shutoff valve body 13 and the plunger 28
The volume of the wheel cylinder increases, which reduces the pressure in the wheel cylinder communicating with the volume chamber 180, and the braking force decreases.

When the control unit determines that the wheel speed has sufficiently recovered, the brake release signal disappears.
Coil 78 is no longer energized. control piston 8
1 moves back to the right by the spring force of the spring 87, and the valve ball 83 closes the throttle passage 93 again. The other valve ball 82 is separated from the valve seat 76 of the communication member 71 as shown in the figure, and the pump pressure chamber P and variable pressure chamber 33 are brought into communication again. Pressure liquid from the hydraulic pump 49 and the accumulator 50 opens the ball valve 44 and flows through the pump pressure chamber P, the passage 74 of the communication member 71, and the throttle passage 7.
5. Grooves 85, 86 of control piston 81, communication chamber 1
01 and is supplied to the variable pressure chamber 33 through the passage 102. At this time, pressure fluid is gradually supplied to the throttle passage 75. As the pressure in the variable pressure chamber 33 increases, the plunger 28 moves to the left, and the volume of the volume chamber 180 decreases. This causes the pressure in the wheel cylinder to start rising again.

When the control unit determines that the brake has been applied too much and generates a release signal again, the coil 78 is energized and the control piston 81 moves to the left. The valve ball 83 opens the throttle passage 93 and the other valve ball 82 closes the throttle passage 75. Transformer room 3
3 to the communication chamber 101, the throttle passage 93, the discharge passages 94, 95, 70, 69, 68, and the pipe line 5.
Reservoir chamber 5 of reservoir chamber 53 through 5 and 54
It is discharged within 9. Plunger 28 moves to the right and the volume of volume chamber 80 increases. This causes the pressure in the wheel cylinder to drop again.

As described above, the pressure in the wheel cylinder repeatedly increases and decreases, and even if sudden braking is applied, the wheels do not lock up and an appropriate braking force can be applied.

In addition, when the above-mentioned brake is activated, the ball valve 4
The hydraulic pressure from the master cylinder acts on the left side of 0, but the hydraulic pressure on the pump 49 side, which is sufficiently high compared to that hydraulic pressure, acts on the right side of the ball valve 40. The resulting leftward pressing force causes the ball valve 40 to
continues to be seated on the valve seat 99, so that the vertical passage 12
The master cylinder side and the pump pressure chamber P are not communicated via the lateral passage 34.

When the pressure on the brake pedal is released, the pressure on the master cylinder connection port 10 decreases, and the brake fluid in the wheel cylinder passes through the wheel cylinder connection port 6, the passage 7, and the groove 23 of the shaft member 24 to the master cylinder side. and reflux. At this time, the plunger 28 connects the ball valve 25 to the valve seat 20 via the shaft member 24.
When the ball valve 25 is not moved back to the left enough to cause the driver to leave the seat, the ball valve 25 is pressed and moved against the spring force of the valve spring 26, and the brake fluid flows back to the master cylinder side. Further, due to the pressure difference generated between the upper and lower sides of the ball valve 96, the ball valve 96 moves away from the valve seat 103 against the spring force of the valve spring 97, and the hydraulic pressure on the reservoir 53 side is released to the master cylinder side. .

Thus, there is no braking force on the wheels, and each part assumes the position shown, but the hydraulic pump 49
Even if the drive is stopped, the hydraulic fluid in the accumulator 50 is kept in a locked state, so that the accumulated pressure at that time can be supplied to the variable pressure chamber 33. As is well known, the hydraulic pump 49 is provided with check valves on the discharge port side and the suction port side, and the check valves on the discharge port side are arranged in the forward direction from the hydraulic pump 49 side to the pipe line 51 side. Therefore, the hydraulic fluid does not flow into the reservoir 53 from the accumulator 50 through the hydraulic pump 49.

The above is a case where the hydraulic pump 49 operates normally, but the case where the hydraulic pump 49 does not operate when it should or the discharge pressure drops abnormally, that is, the case where the hydraulic pump 49 is broken will be explained. do.

First, a case where the accumulated pressure in the accumulator 50 is sufficiently large will be described. When the brake pedal is depressed, the master cylinder connection port 10 and the lateral passage 1
1, brake fluid pressure is applied to the wheel cylinder and plunger 28, but the pressure in the variable pressure chamber 33, that is, the accumulated pressure in the accumulator 50, is sufficiently large, so the plunger 28 does not move to the right and remains stopped. . Therefore, the hydraulic pressure to the wheel cylinders increases rapidly, similar to the case where the hydraulic pump 49 is normal. When the control unit determines that the brake has been applied too much, the coil 78 is energized and the control piston 81 moves to the left. Valve ball 82 seats on valve seat 76 and closes throttle passage 75 of passage 74. The other valve ball 83
is separated from the opening of the throttle passage 93 of the lid member 38. The pressure liquid in the variable pressure chamber 33 flows into the reservoir chamber 59 of the reservoir 53 in the same manner as described above. However, since the hydraulic pump 49 is out of order, no or very little pumping is performed by the hydraulic pump 49. Therefore, the amount of liquid in the reservoir chamber 59 gradually increases. Since the spring 63 is compressed in accordance with this increase, the hydraulic pressure in the reservoir chamber 59 increases, but the spring force of the spring 63 is sufficiently small, and at this time, the hydraulic pressure on the master cylinder side has increased sufficiently. Therefore, the ball valve 96 remains closed.

When the wheel speed is restored and the coil 78 is de-energized, the control piston 81 moves to the right by the spring force of the spring 87, the valve ball 83 closes the throttle passage 93, and the other valve ball 82 closes the throttle passage. Open 75. The pressure liquid in the accumulator 50 is supplied to the variable pressure chamber 33 by opening the ball valve 44 . plunger 28
begins to move to the left, but since the hydraulic pump 49 is out of order, the accumulated pressure in the accumulator 50 decreases as the plunger 28 moves, and finally the passage 1
The hydraulic pressure on the master cylinder side, which is applied via the valve spring 41
The ball valve 40 opens by overcoming the spring force. Further, a decrease in the accumulated pressure in the accumulator 50 is detected by the pressure switch and a fail signal is output to the control unit, so that the coil 78 is not energized and the valve ball 83 of the control piston 81 keeps the throttle hole 93 leading to the reservoir closed. Become. Pressure fluid from the master cylinder connection port 10 passes through passages 12 and 3.
4. It is supplied into the variable pressure chamber 33 through the pump chamber P. That is, the hydraulic pressure on the master cylinder side acts on the right end surface of the plunger 28. The pressure-receiving area of the plunger 28 is equal on the left and right sides, and the plunger 28 is biased to the left by the biasing force of the spring 32.
The plunger 28 can move to the left until it abuts against the shutoff valve body 13. The volume of the volume chamber 180 decreases as the plunger 28 moves to the left, and the hydraulic pressure in the wheel cylinder increases accordingly. The more the ball valve 25 is opened and moved to the left, the more the hydraulic pressure on the master cylinder side increases.

As described above, the pressure fluid from the master cylinder passes through the passages 12 and 34 to open the ball valve 40 and is supplied to the variable pressure chamber 33, and the pressure fluid is discharged from the variable pressure chamber 33 to the reservoir 53. Therefore, after the plunger 28 moves back to the left, it is prevented from moving to the right and the ball valve 25 of the shutoff valve 113 is released from the valve seat 20 via the shaft member 24. It is maintained. Therefore, in response to depression of the brake pedal, the shaft member 24 is moved between the ball valve 25 and the valve seat 20.
Hydraulic pressure from the master cylinder is supplied to the wheel cylinders through the grooves 23, and brakes are applied to the wheels.

Note that while the accumulated pressure in the accumulator 50 is large, the fail signal is not output from the pressure switch to the control unit, and the control piston 78 moves to the left by energizing the coil 81, and the pressure is transferred from the variable pressure chamber 33 to the reservoir 53 several times. Although the brake fluid is discharged, the amount of fluid is small, and as the pressure on the pump chamber P side decreases due to the decrease in the accumulated pressure in the accumulator 50, the ball valve 96 is pumped by pumping the brake pedal. ,40
Since it is possible to open the valve and return the brake fluid from the reservoir 53 to the variable pressure chamber 33 side, there is no problem in brake operation.

When the pressure on the brake pedal is released, the brake fluid flows from the wheel cylinder to the groove 2 of the shaft member 24.
3. The fluid flows back to the master cylinder side through between the ball valve 25 and the valve seat 20, and the hydraulic pressure that was being supplied to the wheel cylinder is released, and the brakes of the wheels are released. Further, due to the pressure difference acting on both the upper and lower sides of the ball valve 96, the ball valve 96 moves away from the valve seat 103 against the spring force of the valve spring 97, and the hydraulic pressure in the reservoir chamber 59 of the reservoir 53 is moved toward the master cylinder side. To be released.

Further, the brake fluid supplied to the pressure transformation chamber 33 and the pump pressure chamber P side is transferred to the transformer 33 and
It is contained within a sealed system on the pump pressure chamber P side. Therefore, even when the brake pedal is depressed again, the plunger 28 remains stopped, the ball valve 25 of the cutoff valve 113 does not sit on the valve seat 20, and the hydraulic pressure from the master cylinder is maintained as normal for the brake. It is fed to the wheel cylinder as well.

Next, if the hydraulic pump 49 is out of order and the accumulated pressure in the accumulator 50 is sufficiently small and the pressure in the variable pressure chamber 33 is also sufficiently small, a fail signal is already output from the pressure switch of the accumulator 50 to the control unit. The coil 78 is de-energized, and the valve ball 83 of the control piston 81 closes the throttle hole 93. In such a case, when the brake pedal is depressed, hydraulic pressure from the master cylinder side is supplied to the wheel cylinder side, but at the same time, the ball valve 40 is opened and the hydraulic pressure is also supplied to the variable pressure chamber 33 via the passages 12 and 34. Ru. Therefore, the plunger 28 remains stationary without moving at all, and the hydraulic pressure in the wheel cylinder quickly increases without increasing the volume chamber 180. When the force on the brake pedal is released and when the brake pedal is pressed again, the operation is the same as in the case described above.

In addition, even though the hydraulic pump 49 has failed and the accumulated pressure in the accumulator 50 has decreased, and a signal is being output from the pressure switch provided in the accumulator 50, the control unit etc. malfunctions and the coil 78 is energized, the control piston 81 moves to the left, and even if the brake fluid is discharged from the variable pressure chamber 33 to the reservoir 53, when the control piston 81 moves back to the right, the pressure fluid from the master cylinder is immediately discharged. The ball valve 40 is opened and the water is supplied to the variable pressure chamber 33 side. Therefore, plunger 2
8 to the right, the ball valve 25 of the shutoff valve 113
does not remain closed, and the hydraulic pressure of the master cylinder is transmitted to the wheel cylinder, thus applying the brakes to the vehicle.

As described above, according to this embodiment, the small diameter hole 3
5 is provided with a valve device consisting of a ball valve 40, a valve spring 41, and a valve seat 99 that opens when the pressure of the hydraulic pump 49 or the accumulator 50 decreases, so that the hydraulic pressure source consisting of the hydraulic pump 49 and the accumulator 50 is prevented from malfunctioning. However, when the brake pedal is depressed, the plunger 28 retreats and the ball valve 25 closes, making it impossible to increase the hydraulic pressure in the wheel cylinder. This avoids the situation where the vehicle is unable to brake. can.

In addition, a ball valve 9 is installed in a small diameter hole 98 between the auxiliary passage, that is, the vertical passage 12 communicating with the master cylinder side, and the passage 68 communicating with the suction port side of the pump 49.
6. A check valve 111 is provided which is composed of a valve spring 97 and a valve seat 103 and is capable of moving liquid only toward the master cylinder, and the discharge passage 6 is provided through this auxiliary passage.
8, 69, 70, 94, 95 and the master cylinder side of the shutoff valve 113, the pressure difference generated between the upper and lower sides of the ball valve 96 when the brake is released causes the ball valve 96 to be moved by the spring force of the valve spring 97. By opening the valve against the resistance, the hydraulic pressure in the system from the throttle hole 93 to the suction port of the pump 49 can be released to the master cylinder side, making it possible to omit the reservoir 53 or reduce its volume. It can be made as small as possible, and the entire brake device can be prevented from increasing in size. In addition, hydraulic pump 4
9 is not so high, if the pressure fluid is quickly discharged from the variable pressure chamber 33 to the reservoir 53 when the coil 78 is energized during anti-skid control, the braking force to the wheel cylinder can be reduced. can be rapidly reduced. The same applies to a driving mode in which the hydraulic pump 49 is started to be driven at the same time as the coil 78 is energized.
However, in either case, the reservoir 5
3 can be made as small as possible. When the hydraulic pump 49 is operated at all times and its capacity is sufficiently high, the hydraulic fluid discharged from the pressure transformation chamber 33 to the reservoir connection port 65 when the coil 78 is energized is immediately transferred to the accumulator by the hydraulic pump 49. 50
The brake force applied to the wheel cylinder can be suddenly reduced. Therefore, in such a case, even if the reservoir 53 is omitted, the braking force can be suddenly reduced.

The embodiments of the present invention have been described above, but of course the present invention is not limited thereto, and various modifications can be made based on the technical idea of the present invention.

For example, in the above embodiment, the hydraulic pressure in the variable pressure chamber 33 can be increased or decreased by moving the control piston 81, and brake pressure can be applied or released.
It is also possible to provide a valve device capable of simultaneously shutting off the three sides, so that the hydraulic pressure in the variable pressure chamber 33 can be kept constant and the brake pressure can be maintained.

Furthermore, in the above embodiments, the left and right pressure receiving areas of the plunger 28 are the same, but a stepped plunger is used to increase the pressure receiving area of the variable pressure chamber 33, so that the pressure receiving area on the left and right sides of the plunger 28 is increased, so that the pressure receiving area on the left and right sides of the plunger 28 is increased. The pressure may be increased even further.

Furthermore, in the embodiments described above, the check valve in the small diameter hole 98 was composed of the ball valve 96, the valve spring 97, and the valve seat 103, but the valve seat 103 was made not on an inclined surface but on a vertical surface, and an axial groove was formed on the outer periphery. A check valve may be used in which a valve rubber is attached to a piston having a piston and the valve rubber is seated on the valve seat, or a check valve operated by an electric signal may be used, and various other known methods may be used. A check valve is applicable.

As described above, in the anti-skid brake hydraulic pressure regulating device of the present invention, the discharge passage connecting the switching valve device and the suction side of the pump is provided with a check valve that allows fluid movement from this passage. By communicating with the master cylinder side of the shutoff valve through the auxiliary passage, the hydraulic fluid reservoir for the master cylinder is used to release hydraulic pressure, and it can be used in a hydraulic system that supplies and discharges pressure to and from the variable pressure chamber. The hydraulic fluid reservoir can be omitted or its volume can be made as small as possible, thereby preventing the entire brake device from becoming larger.

[Brief explanation of the drawing]

The figure is a side sectional view showing a hydraulic pressure regulating device for an anti-skid brake according to an embodiment of the present invention together with a piping system. In the figure, 1...hydraulic pressure adjustment device for anti-skid brake, 2...housing, 3...stepped hole, 6...wheel cylinder connection port, 10...
Master cylinder connection port, 12...Vertical passage, 1
3...Shutoff valve body, 20...Slope portion (valve seat), 2
4...Shaft member, 25...Ball valve, 28...Plunger, 33...Transforming chamber, 34...Transverse passage, 4
9...Hydraulic pump, 50...Accumulator, 6
8, 69, 70, 94, 95...Passage (discharge passage), 78...Coil, 81...Control piston,
82, 83... Valve ball, 96... Ball valve, 97... Valve spring, 98... Small diameter hole, 180... Volume chamber, 1
03...Valve seat, 110...Switching valve device, 111...
...Check valve, 113...Shutoff valve, P...Pump pressure chamber.

Claims (1)

[Claims] 1 A shutoff valve disposed between a master cylinder and a wheel cylinder and capable of blocking communication between the two; a plunger movably provided with one end facing the shutoff valve so as to be able to open and close the shutoff valve; and one end of the plunger. A volume chamber is defined between the side and the shutoff valve and communicates with the wheel cylinder, and whose volume increases or decreases according to the movement of the plunger; a variable pressure chamber to which pressure is supplied and discharged that biases the shutoff valve in the opening direction against the pressure; A pump capable of supplying liquid;
The variable pressure chamber is provided between the pump and the pressure conversion chamber, and is switched in response to an external command between a position where the pressure conversion chamber is communicated with the discharge side of the pump and a position where the pressure conversion chamber is communicated with the suction side of the pump. In an anti-skid brake hydraulic pressure adjustment device comprising a switching valve device, the valve is branched from a discharge passage connecting the switching valve device and the suction side of the pump and connected to the master cylinder side of the shutoff valve. A hydraulic pressure regulating device for an anti-skid brake, comprising an auxiliary passage and a check valve whose forward direction is directed toward the master cylinder.