JPH1068379A - Hydraulically-driven pump and antiskid brake control system using the pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate a need for a motor-driven pump, reduce weight and a cost, and reduce the generation of noise. SOLUTION: A ball valve 62 is opened by a control piston 63 by means of an indication pressure, and the atmosphere flows through the ball valve 62 and a control valve 60 to a pressure variable chamber 57. When a diaphragm piston 55 and a piston rod 66 are advanced, and a piston rod 66 effects stroke by a given amount, the control valve 60 is switched by a switching means 61. The pressure variable chamber 57 is cut off from the atmosphere and communicated with a constant pressure chamber 58, the atmosphere in the pressure variable chamber 57 is discharged through the constant pressure chamber 58, and the piston 55 and the piston rod 66 are moved backward. When the piston rod 66 reaches a non-operation position, the control vale 60 is switched again by the switching means 61, the atmospheric air flows in the pressure variable chamber 57, and the piston 55 and the piston rod 66 are advanced again. As noted above, the piston rod 66 is self-excitedly reciprocated and effects pump operation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of a fluid pressure driven pump which performs a pumping operation by reciprocating a piston rod driven by a fluid pressure. When the lock tendency is released, the brake fluid of the brake cylinder of the wheel is discharged to a low-pressure accumulator to reduce the pressure so that the lock tendency is eliminated, and the discharged brake fluid in the low-pressure accumulator is discharged by a fluid pressure driven pump. The present invention belongs to the technical field of a return pump type anti-skid brake control system (hereinafter, also referred to as ABS) that returns to the master cylinder side and performs anti-skid control (hereinafter, also referred to as ABS control) for adjusting a braking force.

[0002]

2. Description of the Related Art Conventionally, in a braking system for a vehicle such as an automobile, the wheels are locked when the vehicle is braked, so that the steering becomes unstable and the stopping distance becomes long. Various brake systems having an ABS that performs the following have been proposed. One of such conventional ABSs is a return pump type ABS.

FIG. 19 is a diagram showing an example of a conventional brake system provided with a return pump type ABS. As is clear from FIG. 19, the brake system 1 is a two-system hydraulic brake system in which the front and rear wheels F and R are independent, and includes an ABS 2 for each brake system and for each of the left and right wheels. Among the components in each brake system, the same components are denoted by the same reference numerals.

In FIG. 19, reference numeral 3 denotes a brake pedal,
Is a negative pressure booster, 5 is a tandem master cylinder (hereinafter,
MCY), 6 is a reservoir of the master cylinder 5, 7 is a normally open ABS control holding valve composed of a solenoid valve in which a communication position I and a shutoff position II are set, and 8 is a brake fluid passage to the master cylinder 5. , Wheel cylinders (hereinafter also referred to as W / C), 9 is a shut-off position
Normally closed A consisting of a solenoid valve with I and communication position II set
BS control pressure reducing valve, 10 is a sump device which is a low pressure accumulator, 11 is a motor driven ABS control pump (hereinafter also simply referred to as a pump), 12 is an ABS control holding valve 7, an ABS control pressure reducing valve 9 and a sump. An ABS control modulator 13 including a device 10 and a pump 11 is a proportioning valve (hereinafter, also referred to as PV) for reducing a rising gradient of a brake pressure when the rear wheel pressure is equal to or higher than a predetermined pressure.

[0005] FIG. 19 shows the brake system 1 only for the left front wheel _FL and the left rear wheel _RL .
Are provided as well for each ABS control modulator 12 is the right front wheel F _R and the right rear wheel R _R.

In the conventional hydraulic brake system 1 having the ABS 2, the pump 11 is stopped without being driven when the brake pedal 3 is not depressed and the brake is not operated. Both the ABS control pressure reducing valves 9 are set at the position I shown in the figure. Accordingly, the W / Cs 8 of the front and rear wheels F and R are both in communication with the reservoir 6 of the MCY 5, and no W / C pressure in the W / C 8, ie, no brake fluid pressure is generated.

At the time of normal braking by depressing the brake pedal 3, the input shaft 4a of the negative pressure booster 4 advances, and the control valve (not shown) of the negative pressure booster 4 is switched, so that the negative pressure booster is operated. Atmosphere is introduced into the transformer room. This allows
The negative pressure booster 4 operates to boost the pedal depression force to generate an output, and the MCY 5 is operated by the output. MCY5
Generates an MCY pressure, and this MCY pressure passes through the ABS control holding valve 7 on the front wheel brake system side, and the W / C 8
At the rear wheel brake system side, is sent to the W / C 8 through the ABS control holding valve 7 and the PV 13 to generate brake fluid pressure in each W / C 8, and the front and rear wheels F,
R is braked respectively. At this time, MCY
Both the pressure and the W / C pressure are high pressure boosted by the negative pressure booster 4.

When the brake is released by releasing the brake pedal 3, the negative pressure booster 4 and the MCY 5 are deactivated, the MCY pressure disappears, and the brake fluid pressure in each W / C 8 disappears. , R are both released.

During normal braking, when an electronic control unit (not shown) determines that at least one of the front and rear wheels F and R has a locking tendency, it shuts off the ABS control holding valve 7 in the ABS control modulator 12 of the front and rear wheels F and R. By setting the position to the position II, the brake fluid pressure in the W / C 8 is maintained at the brake fluid pressure at that time, and the locking tendency is suppressed from further strengthening. Further, when the electronic control unit determines that at least one of the wheels that tend to lock does not release the lock tendency even when the brake fluid pressure is maintained, the electronic control unit sets the ABS control pressure reducing valve 9 corresponding to the wheel to the communication position. II, and the brake fluid of W / C8 of the wheel is supplied to the sump device 10
And the brake fluid pressure of the W / C 8 is reduced, and the pump 11 corresponding to the wheel is driven.

When the wheel lock tendency is eliminated by the reduction of the brake fluid pressure and the wheel speed is recovered to some extent, the electronic control unit sets the ABS control pressure reducing valve 9 to the shut-off position I and sets the ABS control holding valve 7 To the communication position I. Thus, the hydraulic pressure from the pump 11 is supplied to the W / C 8 together with the MCY pressure, and the brake hydraulic pressure of the W / C 8 is increased again.

In this way, the electronic control unit operates the ABS control holding valve 7, the ABS control pressure reducing valve 9, and the pump 11
Control of the brake fluid pressure,
ABS control by pressure reduction and pressure increase is performed until the tendency to lock the wheels is completely eliminated.

[0012]

By the way, in the brake system 1 provided with such an ABS 2, AB
High S / C boosted by negative pressure booster during S control decompression
Since the pressure is reduced, the amount of the brake fluid discharged to the sump device 10 increases. Then, the low-pressure brake fluid discharged to the sump device 10 is returned to the MCY pressure side considerably higher than the brake fluid, so that the pump 11 has a large capacity as a return pump (for example, 25 MPa; 2 cc / sec) is required.
In addition, a motor for driving such a large-capacity pump requires a large-capacity motor, which causes not only an extremely large weight but also a high cost and a high noise level.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to eliminate the need for a motor-driven pump, to reduce the weight and cost, and to reduce the noise. An object of the present invention is to provide an anti-skid brake control system using a pump.

[0014]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a first aspect of the present invention is to form a fluid pressure source, a constant pressure chamber and a variable pressure chamber, and to form the fluid pressure source into the variable pressure chamber from the fluid pressure source. A piston rod that operates by being supplied with the fluid pressure, a piston rod that performs a pumping action by repeatedly sucking and discharging fluid by reciprocating the piston with and without actuation, and the fluid pressure chamber with the fluid pressure. A control valve for selectively switching and communicating with a source or the constant pressure chamber, a switching means for controlling switching of the control valve according to a stroke of the piston or the piston rod, and Control means for operating the switching means.

According to a second aspect of the present invention, the control valve controls a normally closed supply valve for controlling communication between the fluid pressure source and the variable pressure chamber, and controls communication between the variable pressure chamber and the constant pressure chamber. A normally open discharge valve, wherein the switching means closes the supply valve and opens the discharge valve when not operated by the control means in the non-operation position of the piston or the piston rod, and the control means When activated, the supply valve is opened and the discharge valve is closed, and at a position where the piston or the piston rod has stroked a predetermined amount, the supply valve is closed and the discharge valve is opened.

Further, according to a third aspect of the present invention, the switching means includes:
A flip-flop operation for selectively setting and holding the switching means to a first position in which the supply valve is closed and the discharge valve is opened and a second position in which the supply valve is opened and the discharge valve is closed. When the switching means is not operated by the control means in the non-operation position of the piston or the piston rod, the switching means is set and held at the first position, When the switching means is operated by the control means, the switching means is set and held at the second position,
At a position where the piston or the piston rod has stroked a predetermined amount, the switching means is set and held at the first position.

Further, the invention according to claim 4 is characterized in that a fluid pressure source, a piston that defines a constant pressure chamber and a variable pressure chamber, and is operated by supplying fluid pressure from the fluid pressure source to the variable pressure chamber, The piston rod, which performs pumping by repeatedly sucking and discharging the fluid by reciprocating with the operation and non-operation of the piston, normally shuts off the fluid pressure source and the variable pressure chamber and is supplied with the indicated pressure. An on-off valve that controls the valve to communicate when the valve is closed, a control valve that selectively switches the variable pressure chamber to the on-off valve or the constant-pressure chamber to control the communication, and the control valve according to a stroke of the piston or the piston rod. And switching means for controlling the switching between the two.

According to a fifth aspect of the present invention, the control valve controls a normally open supply valve for controlling communication between the fluid pressure source and the variable pressure chamber, and controls communication between the variable pressure chamber and the constant pressure chamber. A normally closed discharge valve, wherein the switching means opens the supply valve and closes the discharge valve in a non-operation position of the piston or the piston rod, and when the piston or the piston rod strokes a predetermined amount, The supply valve is closed and the discharge valve is opened.

Further, according to the present invention, a fluid pressure source, a piston which defines a constant pressure chamber and a variable pressure chamber, and is operated by supplying a fluid pressure from the fluid pressure source to the variable pressure chamber, The piston rod, which performs pumping by repeatedly sucking and discharging the fluid by reciprocating with the operation and non-operation of the piston, normally shuts off the fluid pressure source and the variable pressure chamber and is supplied with the indicated pressure. An on-off valve that controls the valve to communicate when the valve is closed, a control valve that selectively switches the variable pressure chamber to the on-off valve or the constant-pressure chamber to control the communication, and the control valve according to a stroke of the piston or the piston rod. Control the switching of
A first hydraulic pump and a second hydraulic pump each including switching means for causing the piston rod to stroke during operation; and the switching means of the first hydraulic pressure pump and the switching means of the second hydraulic pressure pump. And an interlocking means for interlocking.

Further, the invention according to claim 7 is characterized in that the control valve includes a valve spool that performs a linear movement, and the switching means converts the linear movement of the piston or the piston rod into a rotational movement, and converts the rotational movement to the rotational movement. It is characterized in that it has a crank that converts the linear movement of the valve spool.

Further, in the invention according to claim 8, the interlocking means includes:
A connecting rotary shaft for connecting the crank of the switching means of the first hydraulic drive pump and the crank of the switching means of the second hydraulic drive pump and integrally rotating both cranks; Have a predetermined phase difference, and are complemented with each other so that even if one of the cranks is at the dead center position, it can be rotated by the rotation of the other crank.

Further, the invention according to claim 9 has a brake operating member, a constant-pressure chamber in which a negative pressure is constantly introduced, and a variable-pressure chamber in which a non-operating negative pressure is introduced and an operating atmosphere is introduced. A negative pressure booster for boosting and outputting the operating force of the brake operating member by operating the control valve by operating the brake operating member and introducing air into the variable pressure chamber; A master cylinder that generates a master cylinder pressure by operating the output of the brake cylinder; a brake cylinder that generates a braking force by introducing the master cylinder pressure; and a low-pressure accumulator that discharges brake fluid from the brake cylinder during anti-skid control. A hydraulic drive pump driven during anti-skid control to recirculate the brake fluid of the low-pressure accumulator to the master cylinder side; A normally-open first electromagnetic on-off valve for controlling the introduction of air, a normally-closed second electromagnetic on-off valve for controlling direct communication between the constant-pressure chamber and the variable-pressure chamber, and shutoff; the master cylinder and the brake cylinder; A normally-open third solenoid on-off valve for controlling the communication and shutoff of these two cylinders, and a passage for connecting the brake cylinder and the low-pressure accumulator, wherein the brake cylinder and the low-pressure accumulator are provided. A fourth solenoid-operated on-off valve that is normally closed and controls communication with the low-pressure accumulator and shuts off the fluid, and the fluid-pressure driven pump is constituted by the fluid-pressure driven pump according to any one of claims 1 to 5. Features.

Further, the invention according to claim 10 has a brake operating member, a constant pressure chamber in which a negative pressure is constantly introduced, and a variable pressure chamber in which a non-operating negative pressure is introduced and an atmosphere is introduced during operation. A negative pressure booster for boosting and outputting the operating force of the brake operating member by operating the control valve by operating the brake operating member and introducing air into the variable pressure chamber; A master cylinder for two systems, which operates by the output of each of the two brake systems to generate a master cylinder pressure for each of the two brake systems, a brake cylinder for each of the two brake systems, to which these master cylinder pressures are respectively introduced to generate a braking force, A low-pressure accumulator for every two brake systems through which the brake fluid of these brake cylinders is discharged during skid control; and a low-pressure accumulator which is driven during anti-skid control. A fluid pressure drive pump for every two brake systems for circulating brake fluid to the master cylinder side, a normally open first solenoid on-off valve for controlling the introduction of air to the negative pressure booster, and the constant pressure chamber A normally-closed second electromagnetic on-off valve for controlling direct communication and disconnection between the cylinder and the transformer chamber, and a passage connecting the master cylinder and the brake cylinder to control the communication and disconnection of these two cylinders A normally open third solenoid on-off valve for every two brake systems, and a passage connecting the brake cylinder and the low-pressure accumulator, for controlling the communication and disconnection between the brake cylinder and the low-pressure accumulator; And a fourth hydraulic on / off valve that is normally closed, wherein the hydraulic drive pumps for each of the two brake systems are respectively a first and a second hydraulic drive according to any one of claims 6 to 8. Is constituted by a pump, each switch means of these two hydraulic drive pump for each brake system is characterized in that it is engaged by the switching means.

[0024]

According to the present invention, when the command pressure is supplied, the control means activates the switching means, so that the switching means switches the control valve to cause the variable pressure chamber to be in fluid pressure. The fluid pressure of the fluid pressure source is supplied to the variable pressure chamber, and the piston is operated. When the piston or the piston rod has made a predetermined stroke, the switching means switches the control valve to communicate the variable pressure chamber with the constant pressure chamber. As a result, the pressure difference between the variable pressure chamber and the constant pressure chamber disappears, and the piston and the piston rod return to the inoperative position. When the piston or piston rod returns to the inoperative position, the switching means switches the control valve again to reconnect the variable pressure chamber to the fluid pressure source and resupply the variable pressure chamber with fluid pressure, after which the fluid pressure driven pump will Repeat the operation. Thus, the piston rod reciprocates self-excitingly.

According to the fourth and fifth aspects of the present invention, when the indicated pressure is supplied, the on-off valve communicates the fluid pressure source with the variable pressure chamber and supplies the fluid pressure of the fluid pressure source to the variable pressure chamber. , The piston operates. When the piston or the piston rod has made a predetermined stroke, the switching means switches the control valve to communicate the variable pressure chamber with the constant pressure chamber. As a result, the pressure difference between the variable pressure chamber and the constant pressure chamber disappears, and the piston and the piston rod return to the inoperative position. When the piston or the piston rod returns to the inoperative position, the switching means switches the control valve, the control valve communicates the variable pressure chamber again with the fluid pressure source, and supplies the fluid pressure to the variable pressure chamber again. Repeats the same operation. Thus, the piston rod reciprocates self-excitingly.

Further, in the invention of claims 6 to 8,
When the indicated pressure is supplied to the first and second fluid pressure driven pumps, the on-off valve communicates the fluid pressure source with the variable pressure chamber and supplies the fluid pressure of the fluid pressure source to the variable pressure chamber, so that the piston operates. I do. When the piston or the piston rod has made a predetermined stroke, the respective switching means of the first and second fluid pressure driven pumps switch their respective control valves in conjunction with each other to communicate the variable pressure chamber with the constant pressure chamber. Thereby, the pressure difference between the variable pressure chamber and the constant pressure chamber disappears, and when the piston or the piston rod returns to the inoperative position, the switching means switches the control valve, and the control valve communicates the variable pressure chamber with the fluid pressure source again,
The fluid pressure is supplied again to the variable pressure chamber, and thereafter, the fluid pressure driven pump repeats the same operation. In this case, since the switching means of the first and second hydraulic drive pumps are interlocked with each other, the two switching means complement each other and operate reliably. Thus, the piston rod reciprocates self-excitingly.

As described above, in the fluid pressure driven pump of the present invention, a motor for driving the pump by being driven by the fluid pressure is not required, and the control valve is switched according to the stroke of the piston or the piston rod to change the piston rod. The self-excited reciprocating motion eliminates the need for an electromagnetic valve, which reduces the weight of the fluid pressure driven pump, reduces costs, and further reduces noise.

In the anti-skid brake control system according to the ninth and tenth aspects of the present invention, the conventional ABS
The motor-driven pump, the motor and the solenoid valve as used in the above are unnecessary. Therefore, the ABS is configured at low cost, and the noise during the ABS control is reduced.

Further, since the brake fluid discharged from the brake cylinder is returned to the MCY side, the amount of the brake fluid sent from the MCY to the brake cylinder is reduced, and the capacity of the low-pressure accumulator can be reduced.

[0030]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram schematically showing an example of an embodiment of an anti-skid brake control system according to the present invention. The same components as those of the conventional anti-skid brake control system shown in FIG. 19 described above are denoted by the same reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 1, the ABS of the present embodiment includes a normally open first solenoid on-off valve 14 for controlling the introduction of the atmosphere to the negative pressure booster 4, and a power piston of the negative pressure booster 4. Normally closed second solenoid on-off valve 15 for controlling communication and shutoff between the chambers on both sides of the valve
Is provided. The vacuum booster 4 will be specifically described. As shown in FIG. 2, the vacuum booster 4 includes a front shell 1 connected to each other by, for example, bayonet coupling.
6 and a rear shell 17.

A valve body 18 is provided so as to penetrate the rear shell 17 between a space formed by the front shell 16 and the rear shell 17 and a space outside the space. Rear shell 1
It is airtightly and slidably supported by the seal member 7 and the seal member 19. The valve body 18 has two shells 16, 1
The power piston member 20 arranged in the space inside 7 is connected. A diaphragm 21 is provided between the shells 16 and 17 and the valve body 18 on the back of the power piston member 20. A power piston 22 is formed by the power piston member 20 and the diaphragm 21. The power piston 22 allows the two shells 16,
The space inside 17 is divided into a constant pressure chamber 23 and a variable pressure chamber 24.

The valve body 18 is formed with a concave fitting portion 25 which opens into the constant pressure chamber 23. The bottom of the concave fitting portion 25 has a central portion projecting toward the constant pressure chamber 23 side.
a is formed. A first hole 26 that opens to the concave fitting portion 25 is formed substantially at the center of the protruding portion 18a, and the rear portion (right side in the drawing) is continuous with the first hole 26.
A second hole 27, a third hole 28, a fourth hole 29, and a fifth hole 30 opening at the rear end of the valve body 18 are formed in this order. Further, an axial passage 31 communicating the constant pressure chamber 23 and the fourth hole 29 is formed in the valve body 18.

A valve plunger 32 is slidably fitted in the first hole 26 and the second hole 27 of the valve body 18. An input shaft 4a linked to a brake pedal (not shown) is connected to the right end of the valve plunger 32. A radial hole 33 is formed in the valve body 18 so as to be orthogonal to the second hole 27, and a key member 34 is fitted through the hole 33 to the valve plunger 32 so as to be relatively movable in the axial direction. ing. The key member 34 can move in the axial direction by the width of the hole 33 together with the valve plunger 32, and the key member 34 prevents the valve plunger 32 from coming out of the valve body 18. Further, a passage 35 is formed in the valve body 18 so as to open to the variable pressure chamber 24 so as to be orthogonal to the second hole 27. This passage 35 also communicates with the third hole 28.

A control valve 36 is provided in the fifth hole 30 of the valve body 18. The control valve 36 is attached to the valve body 18 and is constantly urged in the direction of the valve plunger 32 by a resilient force of a spring 37 interposed between the control valve 36 and the input shaft 4a. A first valve seat 39 formed on the right end of the valve body and a second valve seat 40 formed on the valve body 18. This control valve 36
Means that the valve body 38 is seated on the first valve seat 39 and the second valve seat 40
When the valve is disengaged from the first valve seat 39, the communication between the constant pressure chamber 23 and the variable pressure chamber 24 and the communication between the variable pressure chamber 24 and the atmosphere are interrupted.
When seated on the valve seat 40, the constant pressure chamber 23 and the variable pressure chamber 2
The switching control is performed so as to cut off the communication with the pressure chamber 4 and to connect the variable pressure chamber 24 with the atmosphere. Therefore, the valve body 38 and the first valve seat 39 constitute an atmosphere valve for controlling the introduction of the atmosphere, and the valve body 38 and the second valve seat 40 constitute a vacuum valve for controlling the introduction of the vacuum. ing.

A large-diameter portion on the right end of the output shaft 41 is disposed in the concave fitting portion 25 of the valve body 18. The concave portion formed in the large-diameter portion on the right end slides on the projecting portion 18 a of the valve body 18. They are freely fitted. A reaction disk 42 is housed in the concave portion of the right end large diameter portion between the projection 18 a of the valve body 18 and the output shaft 41. A predetermined gap is interposed between the valve plunger 32 and the reaction disk 42.

The output shaft 41 is prevented from falling out of the valve body 18 by a retainer 44 urged rightward by a return spring 43 for returning the valve body 18 to the inoperative position. Further, the left end of the output shaft 41 is interlocked with a primary piston 5a (shown in FIG. 1) of the master cylinder 5 attached to the front shell 16.

The valve body 18 and each of the power pistons 22 connected thereto are normally held in the inoperative position shown by a return spring 43. In this non-operating state, the key member 34 abuts against the inner surface of the rear shell 17 to regulate the rightward movement of the valve plunger 32 and hold the valve plunger 32 at the retreat limit position. And
When the input shaft 4a is not actuated, the key member 34 is at a position advanced with respect to the valve body 18, and at this time, the valve body 38 is seated on the first valve seat 39, and is slightly different from the second valve seat 40. The gap is maintained, and the variable pressure chamber 24 is isolated from the atmosphere and communicates with the constant pressure chamber 23. Therefore, at the time of braking, as soon as the valve plunger 32 is actuated by the advancement of the input shaft 4a, the valve body 38 is seated on the second valve seat 40, separated from the first valve seat 39, and communicates with the variable pressure chamber 24 and the atmosphere. Are immediately in communication.

The constant pressure chamber 23 is always in communication with a vacuum source 46 (shown in FIG. 1) such as an intake manifold of an engine through a negative pressure introducing pipe 45 attached to the front shell 16. Therefore, a negative pressure is always introduced into the constant pressure chamber 23.

Further, the rear shell 17 is formed with a cylindrical projecting portion 17a projecting rearward.
A hermetic boot 46 made of an elastic material such as rubber is provided between the input shaft 7a and the input shaft 4a so as to completely cover the rear end of the valve body 18 and seal the inside. The first air introduction passage 47 is formed in the boot 46, and the first air introduction passage 47 and the fifth air introduction passage 47 are provided between the inner peripheral surface of the boot 46 and the outer peripheral surface of the rear end of the valve body 18. Annular second air supply passage 48 communicating with the hole 30
Are formed. The first air introduction passage 47 is capable of communicating with the atmosphere via a third air introduction passage 49. In the third air introduction passage 49, a communication position I and a cutoff position II are set. An open first solenoid on-off valve 14 is provided.

The communication between the constant pressure chamber 23 and the variable pressure chamber 24 is made possible by an inter-room communication passage 50. In the inter-room communication passage 50, a shut-off position I and a communication position II are set. The above-mentioned normally closed second electromagnetic on-off valve 15 is provided.

Further, a vacuum drive pump 51 is provided in the ABS 2. As shown in FIG. 3, the vacuum drive pump 51 includes a first housing 52 having a cylinder block shape and a second housing 53 having a U-shaped cross section.

In the first housing 52, a concave fitting portion 54 which opens leftward in FIG. 3 is formed, and a diaphragm piston 55 is disposed in the concave fitting portion 54. The first housing 52 is held between the first housing 52 and a closing plate 56 fixed to the first housing 52 and closing the concave fitting portion 54. Then, the concave fitting portion 5 closed by the closing plate 56 by the diaphragm piston 55
The inside of the space in 4 is divided into a variable pressure chamber 57 and a constant pressure chamber 58. The constant pressure chamber 58 is always in communication with the constant pressure chamber 23 and the vacuum source 46 of the negative pressure booster 4 via a passage 59.

A control valve 60 having a valve spool 60a slidably inserted therein is provided in a hole of the first housing 52. The control valve 60 is operated by a switching means 61 as described later. Controlled, the transformation chamber 57
Is selectively communicated with the constant pressure chamber 58 or the atmosphere. This valve spool 60a and the first housing 5
A slight gap is provided between the two holes.

Further, the ball valve 6 is provided in the first housing 52.
A normally-closed on-off valve 64 including a control piston 2 and a control piston 63 is provided. The control piston 63 of the on-off valve 64 is adapted to operate using the sump pressure of the sump device 10 as a command pressure. That is, when a sump pressure is applied, the control piston 63 moves to the left in FIG. 3 to open the ball valve 62, and communicates the atmosphere to the control valve 60.

Further, a stepped cylinder hole 65 is formed in the first housing 52 so as to penetrate in the axial direction. In the cylinder hole 65, a stepped piston rod 66 slides in a liquid-tight manner. It is provided as possible. One end of the piston rod 66, that is, the large-diameter end, is connected to the diaphragm piston 55, and the other end, that is, the small-diameter end, protrudes outside the first housing 52. The spring force of a return spring 67 supported by the second housing 53 is constantly applied to the other end of the piston rod 66 via a retainer 68.
Are always biased in the non-operation direction.

On the small diameter side of the piston rod 66, an O-ring 69 for sealing between the small diameter side of the piston rod 66 and the large diameter side of the cylinder hole 65, and between the small diameter side of the piston rod 66 and the cylinder hole 65 are formed. An O-ring 70 is provided to seal between the small-diameter side.

Further, the first housing 52 has two O
A suction hole 71 and a discharge hole 72 are formed in a direction perpendicular to the cylinder hole 65 so as to open on the large diameter side of the cylinder hole 65 between the rings 69 and 70. Suction hole 7
1 is communicated with the sump device 10, and the suction hole 71 is provided with a suction-side check valve 73 that allows only the flow of brake fluid from the sump device 10 to the cylinder hole 65. Further, the ejection hole 72 is M
The discharge hole 72 is provided with a discharge-side check valve 74 that allows only the flow of the brake fluid from the cylinder hole 65 toward the MCY5.

The switching means 61 is provided between the piston rod 66 and the valve spool 60a of the control valve 60. As shown in FIG. 4, this switching means 61
A first connecting rod 77 swingably connected between a disk-shaped crank 75 and a connecting rod 76 connected to the first crank pin 75a at an eccentric position on one surface side of the crank 75 and the valve spool 60a. And the crank 75
And a second connecting rod 78 swingably connected between the second crank pin 75b at the eccentric position on the other surface side and the piston rod 66. Then, the linear movement of the piston rod 66 is converted into the rotational movement of the crank 75, and the rotational movement of the crank 75 is converted into the linear movement of the valve spool 60a.
5 is converted into a linear motion of the piston rod 66 and a linear motion of the valve spool 60a.

The ABS of this embodiment is provided for every two brake systems, and therefore, the vacuum drive pump 51 is also provided for every two brake systems. Then, as shown in FIG. 5, for example, the vacuum drive pump 51 'in the ABS of the other brake system (hereinafter, components corresponding to the vacuum drive pump 51 of the one brake system are denoted by the same reference numerals with "'"). ) Is common to the first and second housings 52 and 53 of the vacuum drive pump 51.

In that case, the piston rod 6 of the other system
6 'is arranged in parallel with the piston rod 66 of one system. Also, the cranks 75, 75 'of both systems are the first
The two cranks 75, 75 are connected to each other by a connecting rotary shaft 79 rotatably supported by the housing 52.
75 'and the connecting rotary shaft 79 rotate integrally. Further, in FIG. 4, the first and second crankpins 75a and 75b of one system shown by a solid line and the first and second crankpins 75 of the other system shown by a two-dot chain line.
The phases of a 'and 75b' are set to be shifted from each other by 90 °. Thus, by providing a phase difference between the crank pins of both systems, even if one of the cranks becomes a dead center position and cannot rotate by itself, the other crank rotates, so that one of the cranks rotates. So that both systems of piston rods 66, 66 '
Complement each other to prevent their propulsion from going to zero. Note that the phase difference between the crank pins of both systems can be set to a predetermined angle other than 90 °.

Next, the operation of the two vacuum drive pumps 51 and 51 'constructed as described above will be described.
When not operating, the switching means 61, 61 'of the piston rods 66, 66' of the vacuum drive pumps 51, 51 'and the control valves 60, 60' are in the state shown in FIG. 6, and the control pistons 63, 63 ' The sump pressure of the sump device 10 is not working, and the control pistons 63, 63 'as shown in FIG.
Is in the inoperative position, and the on-off valves 64, 64 'are closed. Further, at this position of the piston rod 66, the first crank pin 75a of the crank 75 of the switching means 61 is located before the upper dead center position with respect to the first connecting rod 77, and the second crank pin 75b is in the second position. The position is slightly past the right dead center position with respect to the two connecting rods 78. Further, the switching spool 61 allows the valve spool 60 a to slightly communicate the variable pressure chamber 57 to the downstream side of the on-off valve 64 and to shut off the variable pressure chamber 57 from the constant pressure chamber 58. However, through a small gap between the valve spool 60a and the hole of the first housing 52, the variable pressure chamber 57 and the constant pressure chamber 58 communicate with each other. The chamber 57 and the constant pressure chamber 58 have the same pressure, and the diaphragm piston 55 does not operate.

On the other hand, the valve drive pump 5 of the other system
In 1 ', the first crank pin 75a' of the crank 75 'of the switching means 61' is located slightly beyond the lower dead center position corresponding to the first connecting rod 77 'and the second crank pin 75a' The crank pin 75b 'is located before the left dead center position with respect to the second connecting rod 78'. Further, the valve spool 6 is switched by the switching means 61 '.
Reference numeral 0a 'is a position for shutting off the downstream side of the on-off valve 64' of the variable pressure chamber 57 'and communicating with the constant pressure chamber 58'. Therefore, a negative pressure is also introduced into the variable pressure chamber 57 ', and the variable pressure chamber 57' and the constant pressure chamber 58 'have the same pressure, and the diaphragm piston 55' does not operate.

Since no sump pressure is generated even when the ABS control is not performed during the brake operation, the vacuum drive pumps 51 and 51 'are maintained in the same state as when the brake is not operated and are not driven.

When the ABS control is performed and the sump pressure is generated in the sump device 10, the sump pressure acts on the control piston 63 in one of the vacuum drive pumps 51 as shown in FIG. Since the control piston 63 operates, the ball valve 62 opens. As a result, the atmosphere flows into the variable pressure chamber through the on-off valve 64 and the control valve 60, so that the diaphragm piston 55 and the piston rod 66 start moving forward as shown by the arrows. As the piston rod 66 starts to move forward, the crank 75 moves as shown in FIG.
6A, the valve spool 60a rotates clockwise, and the valve spool 60a moves upward in FIG. 6A. At this time, since the crank 75 is at a position shifted from the both dead center positions with respect to the first and second connecting rods 77 and 78, the crank 75 easily rotates. This piston rod 66
The brake fluid in the cylinder hole 65 is discharged to the MCY 5 via the discharge-side check valve 74 by the start of the forward movement.

On the other hand, as shown in FIG. 6B, in the vacuum drive pump 51 'of the other system, the sump pressure similarly acts on the control piston 63', and the control piston 63 '
The actuation of 3 'causes the ball valve 62' to open. As a result, the atmosphere flows into the control valve 60 '. However, since the control valve 60' cuts off the communication between the on-off valve 64 'and the transformation chamber 57', the atmosphere flows into the transformation chamber 57 '. do not do. Therefore, the piston rod 66 'does not move by itself. However, the clockwise rotation of the crank 75 of one system causes the crank 75 ′ of the other system to rotate counterclockwise via the connecting rotary shaft 79 as shown in FIG. The rotation of the crank 75 ', that is, the propulsive force of the piston rod 66 of one system causes the piston rod 6' and the diaphragm 55 'to start retreating. With the start of the retraction of the piston rod 66 ′, the brake fluid in the sump device 10 is sucked into the cylinder hole 65 via the suction side check valve 73. Also,
The rotation of the crank 75 'causes the valve spool 60a'
Moves upward, and the variable pressure chamber 57 ′ and the constant pressure chamber 5 in the control valve 60 are moved.
8 'becomes smaller.

When the piston rod 66 of one system is further advanced, the crank 75 is further rotated and the valve spool 60 is further moved upward, but as shown in FIG.
The dead center position (uppermost position) above the crank pin 75a
, The valve spool 60a moves downward after passing through the uppermost position. At this time, a large valve opening between the variable pressure chamber 57 of the control valve 60 and the on-off valve 64 is maintained, and the amount of air flowing into the variable pressure chamber 57 is maintained in a large state. Then, the discharge of the brake fluid from the discharge hole 72 to the MCY 5 is continued.

On the other hand, the crank 75 'of the other system is further rotated, and as shown in FIG. 7B, the second crank pin 75b' of the crank 75 'is at the left dead center position, and the piston rod 66' Is the retreat position. This allows
The suction of the brake fluid from the sump device 10 'stops. Further, the valve spool 60a 'further moves upward, and the control valve 60' completely shuts off the space between the variable pressure chamber 57 'and the constant pressure chamber 58'.

As shown in FIG. 8A, when the piston rod 66 of one of the systems further advances, the valve spool 6
As 0a further moves down, the control valve 60 completely shuts off the connection between the variable pressure chamber 57 and the on-off valve 64. For this reason, the air does not flow into the transformation chamber 57, and the diaphragm piston 55 and the piston rod 66 do not stroke by themselves.

On the other hand, as shown in FIG. 8B, the other system crank 75 'is connected to the one system piston rod 66.
The second crank pin 75b 'further rotates beyond the left dead center position by the propulsion force, and the piston rod 66' moves forward from the retreat limit position. With the advance of the piston rod 66 ', the sucked cylinder hole 6
The brake fluid in 5 'passes through the discharge side check valve 74' and is discharged from the discharge hole 72 'to the MCY5.

Since the valve spool 60a 'is further moved upward by the rotation of the crank 75', the control valve 60 '
Communicates between the variable pressure chamber 57 'and the on-off valve 64'. As a result, the atmosphere is switched between the on-off valve 64 ′ and the control valve 6.
After passing through 0 'into the transformation chamber 57', the diaphragm piston 55 'and the piston rod 66' advance by themselves. At this time, the crank 75 'also rotates by its own advance of the piston rod 66', so that the crank 75 of one system is rotated by the propulsive force of the piston rod 66 '. Therefore, the piston rod 66 of one system is not self-powered, but continues to move forward, and the discharge of the brake fluid is further continued.

When the piston rod 66 'of the other system advances further, the crank 75' rotates further and the valve spool 60 'further moves upward, but as shown in FIG. 9B, the first crank pin 75a Passes through the upper dead center position (uppermost position), the valve spool 60a 'moves downward after passing through the uppermost position. At this time, a large valve opening between the variable pressure chamber 57 'of the control valve 60' and the on-off valve 64 is maintained, and the amount of air flowing into the variable pressure chamber 57 'is maintained in a large state. Then, the discharge of the brake fluid from the discharge holes 72 'to the MCY5 is continued.

On the other hand, when the crank 75 of one system is further rotated and the piston rod 66 is further advanced, FIG.
As shown in (a), the crank 75 has its second crank pin 75b located at the left dead center position, and the piston rod 66
Is the forward limit position with full stroke. This allows
The discharge of the brake fluid to the MCY5 stops. Further, the valve spool 60a further moves downward, and the control valve 60
7 and the constant pressure chamber 58 are completely shut off.

The other system vacuum drive pump 51 ′
When the piston rod 66 'is further advanced, the second crank pin 75b' of the crank 75 'is at the right-hand dead center position, as shown in FIG. Becomes Thereby, the MCY5 from the vacuum drive pump 51 'is
The discharge of brake fluid to the pump stops. Further, the valve spool 60a 'moves further downward, and the control valve 60'
The connection between the valve 7 'and the on-off valve 64' is completely shut off. For this reason, the air does not flow into the transformation chamber 57 ', and the diaphragm piston 55' and the piston rod 66 do not stroke by themselves.

On the other hand, the crank 75 of one system further rotates the second crank pin 75b beyond the left dead center position by the propulsive force of the piston rod 66 'of the other system,
The piston rod 66 is now retracted from the advanced position. This retraction of the piston rod 66 causes the brake fluid of the sump device 10 to be sucked into the cylinder hole 65 from the suction hole 71 through the suction side check valve 73.

Then, as shown in FIG. 10A, the rotation of the crank 75 lowers the valve spool 60a further, so that the control valve 60 communicates between the variable pressure chamber 57 and the constant pressure chamber 58. . As a result, the air flowing into the variable pressure chamber 57 is discharged to the vacuum source 46 via the control valve 60, the constant pressure chamber 58, and the passage 59. For this reason, the transformer chamber 5
The pressure difference between the pressure chamber 7 and the constant pressure chamber 58 disappears, and the spring force of the return spring 67 causes the piston rod 66 to retreat by itself.

At this time, the crank 75 rotates by itself due to the retreat of the piston rod 66 by itself, so that the crank 75 ′ of the other system rotates beyond the dead center position on the right side by the propulsive force of the piston rod 66. become.
Therefore, the piston rod 66 'of the other system is not self-powered but starts retreating and starts sucking the brake fluid.

In the vacuum drive pump 51 of one system, the piston rod 66 further retreats to suck the brake fluid, and as shown in FIG. When the vehicle retreats beyond the position to the retreat limit position which is a non-operation position, the suction of the brake fluid stops. At this time, the valve spool 60 moves upward to slightly communicate between the variable pressure chamber 57 and the on-off valve 64,
Atmosphere flows into the transformation chamber 57 again. As a result, the piston rod 66 moves forward again as in the case shown in FIG.

On the other hand, in the vacuum drive pump 51 'of the other system, since the valve spool 60a' moves further downward as shown in FIG. 11B, the control valve 60 'is connected to the variable pressure chamber 57' and the constant pressure chamber 58. ′. Thus, the air flowing into the variable pressure chamber 57 'is discharged to the vacuum source 46 via the control valve 60', the constant pressure chamber 58 ', and the passage 59'. Therefore, the pressure difference between the variable pressure chamber 57 'and the constant pressure chamber 58' disappears, and the piston rod 66 'is retracted by itself by the spring force of the return spring 67', so that the brake fluid is sucked.

Thus, both piston rods 66, 66 '
While the sump pressure is present in the sump devices 10 and 10 ', that is, during the ABS control, the reciprocating motion is repeatedly self-excited and the control valves 60 and 60' are switched to switch the brakes from the sump devices 10 and 10 '. Liquid suction and MC
The discharge of the brake fluid to Y5 is repeatedly performed.
That is, both the vacuum drive pumps 51, 51 'are AB
During the S control, a pump action is performed. In this case, the operation of the vacuum drive pump 51 ′ of the other system operates with a phase delay of 90 ° from the operation of the vacuum drive pump 51.

When the ABS control is completed and the brake fluid is no longer discharged from the W / Cs 8, 8 'to the sump devices 10, 10' and the sump pressure decreases, the control piston 63,
63 'returns to the inactive position and ball valves 62, 62' close. As a result, the air does not flow into each of the variable pressure chambers 57, 57 ', and the air in both the variable pressure chambers 57, 57' passes through the gaps on the outer periphery of the valve spools 60a, 60a 'and the constant pressure chambers 58, 58'. And is discharged toward the vacuum source 46. Thus, both vacuum drive pumps 51, 5
1 'returns to the inoperative position, and the two vacuum drive pumps 5
The drive of 1,51 'stops. The other configuration of the ABS2 of this example is the same as the configuration of the ABS of FIG.
The operation of the brake system 1 including the ABS of this example will be described.

When the vacuum booster 4 is in the inoperative position shown in the figure, the valve body 38 of the control valve 36 is seated on the first valve seat 39 and maintains a slight gap with the second valve seat 40. And
The atmosphere valve is closed and the vacuum valve is open. Therefore, since both the constant pressure chamber 23 and the variable pressure chamber 24 have a negative pressure, the negative pressure booster 4 does not operate.

Further, the first solenoid on-off valve 14 is set at the communication position I to communicate the third air supply passage 49 to the atmosphere, and the second solenoid on-off valve 15 is set at the shut-off position I so that the room is closed. The connection passage 50 is shut off. Therefore, the fifth hole 3
0 communicates with the atmosphere via a second air supply passage 48, a first air supply passage 47, a third air supply passage 49, and an open first electromagnetic on-off valve 14, and a constant pressure chamber of the negative pressure booster 4. 23 and the transformation chamber 24 do not communicate with each other via the inter-room connection passage 50. Further, the ABS control holding valves 7, 7 'are set at the communication position I, and the ABS control pressure reducing valves 9, 9' are set at the shut-off position I. Further, since no sump pressure is generated in the sump devices 10, 10 ', the vacuum drive pump 51,
51 'does not work.

When the brake pedal 3 is depressed to perform normal braking in this state, the input shaft 4a moves forward toward the valve body 18. By the advance of the input shaft 4a, the valve plunger 32 moves the key member 34 and the valve body 1
8 and the valve body 38 of the control valve 36 is in the second position.
While seated on the valve seat 40, the first valve seat 3
9 leaves, the vacuum valve closes and the atmosphere valve opens. As a result, the atmosphere communicating with the fifth hole 30 is released from the valve body 38.
Through the gap between the first valve seat 39 and the third hole 28 and the passage 35 into the variable pressure chamber 24.

The power piston 22 is actuated by the air flowing into the variable pressure chamber 24 and the valve body 18 moves forward, so that the negative pressure booster 4 generates an output from the output shaft 41,
As in the conventional case, the pistons 5a and 5b of the MCY 5 operate to generate MCY pressure. This MCY pressure is supplied to the W / Cs 8, 8 'through the first solenoid on-off valves 7, 7' in the same manner as in the prior art, and the normal brake is operated. At this time, the MCY pressure is prevented from being supplied into the vacuum drive pump 51 by the discharge side check valves 74 and 74 '.

When the valve body 38 is seated on the first valve seat 39 and the atmosphere valve is closed, the air does not flow into the variable pressure chamber 24,
The advance of the valve body 18 stops. Thus, the negative pressure booster 4 generates a boosted output at a predetermined servo ratio corresponding to the input.

Normally, the brake pedal 3 for releasing the brake
Is released, the input shaft 4a is retracted, and the valve plunger 32 is retracted relatively to the valve body 18 until the key member 34 contacts the rear surface of the hole 33. By the retreat of the valve plunger 32, the valve element 38 is moved to the second valve seat 40.
And the vacuum valve is opened, and the air introduced into the transformation chamber 24 passes through the passage 35, the third hole 28, the valve body 38 and the second valve seat 40.
, Passage 31, constant pressure chamber 23 and negative pressure introducing pipe 45
Through the vacuum source 46 and the pressure in the transformer chamber 24 decreases. As a result, the spring force of the return spring 43 causes the valve body 18 and the power piston 22 to retreat, and the vacuum booster 4 shown in FIG. Therefore, MCY5 also becomes inactive, and W / C
The brake fluid pressure at 8, 8 'disappears, and the normal brake is released.

When the controller (not shown) detects at least one locking tendency of the wheels during braking by the operation of the negative pressure booster 4, similarly to the conventional general ABS control,
Turn on both the first and second solenoid on-off valves 14, 15;
Therefore, the first solenoid on-off valve 14 closes and the second solenoid on-off valve 15 opens. Therefore, the fifth hole 30 is shielded from the atmosphere, and the variable pressure chamber 24 communicates with the constant pressure chamber 23 via the inter-room connection passage 50 and the open second electromagnetic switching valve 15. Thereby, the air in the variable pressure chamber 24 is
3, the pressure difference between the variable pressure chamber 24 and the constant pressure chamber 23 is reduced, the output of the negative pressure booster 4 is reduced, and the MCY pressure of the MCY 5, that is, the brake pressure of the W / C 8, 8 'is reduced. Both are decompressed.

At this time, the output of the negative pressure booster 4 lowers, so that the valve body 18 retreats and the valve body 38 is moved to the first valve seat 3.
9. Separate from 9 and open the air valve. However, since the fifth hole 30 is shielded from the atmosphere, the air in the cab does not flow into the variable pressure chamber 24 even when the atmosphere valve is opened, and the output of the negative pressure booster 4 does not increase.

When the brake pressure is reduced due to the decrease in the output of the negative pressure booster 4, the locking tendency of the wheels is not eliminated. If the pressure needs to be further reduced, the controller sets the ABS control holding valves 7, 7 '. Set to the cutoff position II, and
The S control pressure reducing valves 9, 9 'are set to the communication position II. As a result, the W / Cs 8, 8 'are cut off from the MCY 5, and communicate with the sump devices 10, 10', so that the W / Cs 8, 8 'are formed.
The brake fluid inside is discharged to the sump devices 10, 10 ',
The brake pressure of W / C 8, 8 'is further reduced. Then, the sump pressure is generated by discharging the brake fluid into the sump devices 10, 10 '.

Since the sump pressure acts on the control pistons 63, 63 'of the on-off valves 64, 64', the vacuum drive pumps 51, 51 'operate as described above by the differential pressure between the atmosphere and the vacuum. And the sump device 1
The brake fluid within 0,10 'is circulated to MCY5.

When the wheel speed recovers to a predetermined speed due to the reduction of the brake pressure, the controller moves the ABS control holding valves 7, 7 'to the communication position I and sets the ABS control pressure reducing valves 9,
9 'at the shut-off position I, and the first solenoid on-off valve 14 at the communication position I
And the second solenoid on-off valve 15 is set to the shut-off position I.

For this reason, the sump devices 10, 10 'have W
Since the brake fluid is no longer discharged from / C8, 8 'and the sump pressure in the sump devices 10, 10' decreases, the driving of the vacuum drive pumps 51, 51 'is stopped as described above.

Further, the fifth hole 30 communicates with the atmosphere again, and the variable pressure chamber 24 is cut off from the constant pressure chamber 23 via the inter-room connection passage 50. W / C 8, 8 'is MCY5.
And cut off from the sump devices 10, 10 '. As a result, the flow of the air in the variable pressure chamber 24 to the constant pressure chamber 23 is stopped, and the air again flows into the variable pressure chamber 24. Therefore, the output of the negative pressure booster 4 increases, and the brake pressure increases. Is increased.

In this way, the controller keeps the ABS control holding valve 7, 7 until the tendency to lock the wheels is completely eliminated.
7 ', the ABS control pressure-reducing valves 9, 9', and the first and second electromagnetic on-off valves 14, 15 are repeatedly turned on and off, thereby performing ABS control for repeating brake pressure reduction control and pressure increase control. . Each time the pressure reduction and pressure increase control is repeated, the brake fluid of the sump devices 10, 10 'discharged from the W / Cs 8, 8' is returned to the MCY 5 again by the vacuum drive pumps 51, 51 '. .

The vacuum drive pumps 51, 5 of this example
1 'eliminates the need for a motor for driving the motor-driven pump 11 as in the prior art shown in FIG. 19, and is integrated into the vacuum-driven pump and reduces the stroke of the piston rods 66, 66'. When the control valve for controlling the supply and discharge of the fluid pressure to the variable pressure chamber 57 is switched in response, the piston rods 66 and 66 'reciprocate self-excitingly. Absent. Therefore, the vacuum drive pump is reduced in weight, cost is reduced, and noise is further reduced.

Further, according to the ABS 2, since the vacuum drive pumps 51 and 51 'are used, the ABS control pump is reduced in weight, the ABS can be constructed at a low cost, and the noise during the ABS control is reduced.

Also, since the brake fluid discharged from the W / Cs 8, 8 'is returned to the MCY5 side, the MCY5
5 and the sum of the brake fluid to the W / C 8, 8 'can be reduced, and the sump devices 10, 10' can be reduced.

In this embodiment, the command pressure of the on-off valve 64 is the sump pressure, but the MCY pressure may be used as the command pressure. In this example, a vacuum drive pump that operates at a pressure difference between the vacuum and the atmospheric pressure is used as a pump for circulating the brake fluid of the sump device 10 to the MCY 5, but the pressure difference between the atmospheric pressure and the positive air pressure is used. It is also possible to use an air-driven pump that operates with.

Further, in the above-described example, the on-off valves 64, 64 'are provided for each of the vacuum drive pumps 51, 51', but the on-off valves 64, 64 'are provided for both the vacuum drive pumps 51, 51'.
51 'may be provided in common.

FIG. 12 is a view similar to FIG. 1 showing another example of the ABS of the present invention, and FIG. 13 is a sectional view of a vacuum drive pump 51 used in the ABS. In addition,
The same reference numerals are given to the components corresponding to the above-described example of the present invention and the conventional example, and the detailed description thereof will be omitted.

As shown in FIG. 12, the vacuum drive pump 51 of this example is formed in a tandem type and is provided in common for two brake systems. As shown in FIG. The cylinder hole 65 is formed as a two-step cylinder hole, and the piston rod 66 is formed as a two-step piston rod. An O-ring 69 for sealing between the large-diameter portion of the cylinder hole 65 and the middle-diameter portion of the piston rod 66 is provided at the middle-diameter portion of the piston rod 66. An O-ring 69 'is provided for sealing between the middle diameter portion of the hole 65 and the small diameter portion of the piston rod 66.

A suction hole 71 and a discharge hole 72 of one of the brake systems are formed so as to open at a large diameter portion of the cylinder hole 65 between the O-rings 69, 69 '. A suction hole 71 ′ and a discharge hole 72 ′ of the other brake system are formed so as to open to the middle diameter portion of the cylinder hole 65 between 69 ′ and 70 ′. These suction holes 71, 71 'are provided with suction-side check valves 73, 73', respectively, and the discharge holes 72, 72 'are provided with discharge-side check valves 74, 74', respectively. .

A variable pressure chamber 57 and a constant pressure chamber 58 are provided at an attachment portion 66a of the piston rod 66 to the diaphragm piston 55.
And a first communication passage 80 that communicates with the piston rod 66 and the first housing 52.
A second communication passage 81 that communicates the transformation chamber 57 with the atmosphere is provided. The first communication passage 80 has a flange 82a at one end.
Is fitted slidably,
A valve portion 83a provided on a flange 82a of the valve body 82
And a valve seat 83b formed at the end of the piston rod 66 on the side of the variable pressure chamber 57, constitutes a discharge valve 83. Further, two lateral through holes 84 and 85 are formed in the tubular portion of the valve body 82, and an axial inner hole 82b of the tubular portion is formed.
An aperture 86 is provided at the bottom. Therefore, this aperture 8
The pressure changing chamber 57 and the constant pressure chamber 58 are always in communication with each other through the inner hole 6 and the inner hole 82b. Further, the valve element 82 is
7, the valve portion 83a is constantly urged in a direction to separate from the valve seat 83, that is, in a direction to open the discharge valve 83. When the discharge valve 83 is opened, the variable pressure chamber 57 and the constant pressure chamber 5
8 is an open discharge valve 83, a through hole 84, and an inner hole 82b.
It is designed to communicate without being squeezed through.

On the piston rod 66 side of the second communication passage 81, a supply valve 88 comprising a valve body 88a and a valve seat 88b is provided. The distal end of the valve body 88a can be brought into contact with the flange 82a of the valve body 82 of the discharge valve 83.
a is urged in a direction to seat the valve seat 88b, that is, a direction in which the supply valve 88 is closed. Further, the above-described on-off valve 64 is provided on the first housing 52 side of the second communication passage 81. The MCY pressure is applied to the control piston 63 of the on-off valve 64 via a passage hole 90 and a discharge hole 72 formed in the first housing.

Further, the flange 8 of the valve body 82 of the discharge valve 83
At the position of the first housing 52 where the end opposite to 2a faces, a stopper 91 is provided to which the end of the valve element 82 can abut. The other configuration of the vacuum drive pump 51 of this example is the same as the configuration of the vacuum drive pump 51 of the above-described example.

Next, the operation of the thus-configured vacuum drive pump 51 of this embodiment will be described. When not operating, the vacuum drive pump 51 is in the state shown in FIG. That is, since the master cylinder 5 is not operating, the MCY pressure does not operate on the control piston 63, and the ball valve 62 is closed. Further, the piston rod 6 is urged to the left in FIG. 13 by the return spring 67 so that the flange 82a of the valve body 82 is in contact with the closing plate 56, and the valve rod 83a of the flange 82a The left end valve seat 83b abuts, the discharge valve 83 is closed, and the diaphragm piston 55 and the piston rod 66 are held at this retreat limit position. Further, the valve body 88a of the supply valve 88
Abuts against the flange 82a and the valve body 88a
b, the supply valve 88 is open. In this state, since the variable pressure chamber 57 communicates with the constant pressure chamber 58 via the throttle 86, the negative pressure of the constant pressure chamber 58 is also supplied to the variable pressure chamber 57, and the two chambers 57 and 58 have the same pressure. The diaphragm piston 55 does not operate.

When the MCY pressure is generated by the brake operation, the MCY pressure acts on the control piston 63. When the MCY pressure rises to a predetermined pressure, the control piston 6
3 operates to open the ball valve 62. For this reason, the atmosphere flows into the variable pressure chamber 57 through the second communication passage 82 and the on-off valve 64 supply valve 88. The air flowing into the transformer chamber 57 is throttled 86
Flows through the pressure chamber 58, but the flow of the atmosphere is restricted by the restrictor 86. Therefore, a pressure difference is generated between the variable pressure chamber 57 and the constant pressure chamber 58, and the diaphragm piston 55 operates. The diaphragm piston 55 and the piston rod 66 move forward. Thereby, the cylinder hole 6
5 is discharged to the MCY5.

The piston rod 66 moves forward and the discharge valve 8
Since the third valve body 82 contacts the stopper 91 to prevent further advance, the valve portion 83a is separated from the valve seat 83b, the discharge valve 83 is opened, and the distal end of the valve body 88a is moved from the flange 82a. The valve body 88a is separated from the valve seat 88b.
And the supply valve 88 closes. Thereby, the transformer room 5
At the same time, the flow of the air into the pressure chamber 7 stops, and the air in the variable pressure chamber 57 flows into the constant pressure chamber 58 through the discharge valve 83. Therefore, there is no pressure difference between the two chambers 57 and 58.

When the pressure difference between the two chambers 57 and 58 disappears, both the piston rod 66 and the diaphragm piston 55 retreat to the left by the spring force of the return spring 67. Due to the retraction of the piston rod 66,
The brake fluid is sucked from the sump devices 10, 10 'through the suction holes 71,
The air is sucked through the suction check valves 73 'and 73'.

When the piston rod 66 retreats, first, the flange 82a of the valve element 82 comes into contact with the closing plate 56, and then the tip of the valve element 88a of the supply valve 88 comes into contact with the flange 82a, so that the valve element 88a comes into contact with the valve seat 88b. From the supply valve 8
8 is opened again, the valve seat 83b at the left end of the piston rod 66 abuts on the valve portion 83a of the flange 82a, and the discharge valve 83 is closed again, so that the diaphragm piston 55 and the piston rod 66 shown in FIG. Become.
Then, when the supply valve 88 is opened again, the atmosphere flows into the variable pressure chamber 57 as described above, the diaphragm piston 55 and the piston rod 66 advance, and the brake fluid is discharged to the MCY 5. Thereafter, while the open / close valve 64 is opened and the air is introduced toward the supply valve 88, the piston rod 66 repeats the forward and backward reciprocating motions in this manner, and repeats the discharge and suction of the brake fluid. , The vacuum drive pump 51 is the sump device 1
A pumping action for circulating the brake fluid in 0,10 'to MCY5 is performed.

When the brake is not operated, the MCY pressure is reduced, the control piston 63 returns to the non-operating position, and the ball valve 62 is closed. As a result, the air does not flow into the transformation chamber 57, and the operation of the piston rod 66 stops.

The other structure, operation and effect of the ABS 2 of this embodiment are the same as those of the above-described ABS 2.

In this example, the command pressure of the on-off valve 64 is set to MC
Although the Y pressure is used, a sump pressure may be used as the instruction pressure. However, in this case, the vacuum drive pump 51 operates only during the ABS control.

In this embodiment, a vacuum drive pump operating at a pressure difference between the vacuum and the atmospheric pressure is used as a pump for circulating the brake fluid of the sump device 10 to the MCY 5. It is also possible to use an air-driven pump that operates with a differential pressure.

Further, although a tandem type pump is used as the vacuum drive pump 51, a single type pump may be used. In this case, one pump is provided for each brake system. However, when the ABS control of only the brake system is performed, the vacuum drive pump 51 of the other system in which the ABS control is not performed operates. Therefore, useless operation can be prevented, and durability is improved.

FIG. 14 is a view similar to FIG. 1 showing still another example of the ABS of the present invention, and FIG. 15 is a sectional view of a vacuum drive pump 51 used in the ABS. Note that the same reference numerals are given to components corresponding to each of the above-described examples of the present invention and the conventional example, and a detailed description thereof will be omitted.

As shown in FIG. 14, in the vacuum drive pump 51 of this embodiment, the open / close valve 64 of the embodiment shown in FIGS.
Is not provided. Further, as shown in FIG. 15, the mounting portion 66a of the piston rod 66 is directly in contact with the closing plate 56 when not operating. Thus, when not operated, the valve portion 83a of the discharge valve 83 is set so as to separate from the valve seat 83b and the discharge valve 83 is opened, and the valve body 88a of the supply valve 88 is connected to the valve seat 88b. The supply valve 88 is set so as to be seated and closed.

Further, in this example, the valve element 82 of the discharge valve 83
A connection rod portion 82c slidably and airtightly extending through the first housing 52 is provided. Further, a control piston 92 is provided in the first housing 52, and the control piston 92 has an inverted U-shaped locking portion 9.
2a is provided. The connecting rod portion 82c further penetrates the one arm portion 92b of the locking portion 92a so as to be slidable, and is connected to the connecting rod portion 82c by a locking ring 94 provided at an end of the connecting rod portion 82c. Part 8
2c and the control piston 92 are locked in a direction away from each other. Further, a stopper 91 is provided at a position of the other arm of the locking portion 92a facing the end of the connecting rod portion 82c, with which the end of the connecting rod portion 82c can abut. Therefore, the valve body 82 and the control piston 92 can be relatively moved by a distance substantially between the two arms of the locking portion 92a. Further control piston 9
2, the atmosphere and the spring force of the spring 93 always act in the direction in which the valve portion 83a of the discharge valve 83 is separated from the valve seat 83b.
Is applied with a sump pressure in a direction in which the valve seats on the valve seat 83b. The other configuration of the vacuum drive pump 51 of the present example is the same as the configuration shown in FIG.

Next, the operation of the thus-configured vacuum drive pump 51 of this embodiment will be described. When not operating, the vacuum drive pump 51 is in the state shown in FIG. That is, since no sump pressure is generated, the control piston 92 does not operate, the supply valve 88 is closed, and the discharge valve 83 is open. In this state, the air does not flow into the transformation chamber 57 and the transformation chamber 57 and the constant-pressure chamber 58 communicate with each other.
Is supplied with the negative pressure of the constant pressure chamber 58, the two chambers 57 and 58 have the same pressure, and the diaphragm piston 55 does not operate.
Since no sump pressure is generated even when the ABS control is not performed during the brake operation, the vacuum drive pump 51 is not driven while maintaining this state.

When the ABS control is performed, the sump device 10
At the control piston 92.
To work. When the sump pressure rises to a predetermined pressure, the control piston 92 strokes rightward in FIG. 15, so that the valve body 82 also moves rightward relative to the piston rod 66. By the movement of the valve element 82, the valve portion 83a is seated on the valve seat 83b and the discharge valve 83 is closed. The valve body 88a of the supply valve 88 is separated from the valve seat 88b by the
8 is opened, the atmosphere passes through the second communication passage 81 and is
Flow into 7. The air flowing into the variable pressure chamber 57 flows into the constant pressure chamber 58 through the throttle 86 in the same manner as described above.
7, 58, a pressure difference is generated between the diaphragm piston 5
5 and the piston rod 66 are advanced. This allows
The brake fluid in the cylinder hole 65 is discharged to the MCY5.

When the piston rod 66 moves forward, the discharge valve 8
When the connecting rod portion 82c of the third valve body 82 comes into contact with the stopper 91, further advance of the valve body 82 is prevented, so that the valve portion 83a is separated from the valve seat 83b, and the discharge valve 83 is opened and opened. Since the tip of the valve body 88a is separated from the flange 82a, the valve body 88a is seated on the valve seat 88b, and the supply valve 88 is closed. As a result, the inflow of the atmosphere into the transformation chamber 57 is stopped, and the atmosphere in the transformation chamber 57 is discharged by the discharge valve 83.
And flows into the constant pressure chamber 58. Therefore, both rooms 5
There is no pressure difference between 7,58.

When the pressure difference between the two chambers 57 and 58 disappears, both the piston rod 66 and the diaphragm piston 55 retreat to the left by the spring force of the return spring 67. Due to the retraction of the piston rod 66,
The brake fluid is sucked from the sump devices 10, 10 'through the suction holes 71,
The air is sucked through the suction check valves 73 'and 73'.

When the piston rod 66 retreats, the mounting portion 66a of the piston rod 66 comes into contact with the closing plate 56, and the piston rod 66 returns to the inoperative position. But,
Since the sump pressure is acting on the control piston 92, the control piston 92 moves the valve body 82 again, closes the discharge valve 83 again, and opens the supply valve 88 again. As a result, the air flows into the transformation chamber 57 in the same manner as described above, and the diaphragm piston 55 and the piston rod 6
6 advances again, and the brake fluid is discharged to MCY5.
Thereafter, during the stroke caused by the sump pressure acting on the control piston 92, the piston rod 66 repeats the reciprocating movement in this way, and repeats the discharge and suction of the brake fluid. The brake fluid in 10, 10 'is circulated to MCY5.

When the ABS control is completed, the sump pressure decreases, so that the control piston 92 returns to the inoperative position, the discharge valve 83 opens, and the supply valve 88 closes. As a result, the air does not flow into the variable pressure chamber 57, and the air in the variable pressure chamber 57 is discharged to the vacuum source 46 through the discharge valve 83 and the constant pressure chamber 58, so that the driving of the vacuum drive pump 51 is stopped. The other configuration, operation, and effect of the ABS of this embodiment are the same as those of the above-described embodiments.

FIG. 16 is a view similar to FIG. 1 showing still another example of the ABS of the present invention, and FIG. 17 is a sectional view of a vacuum drive pump 51 used in the ABS. Note that the same reference numerals are given to components corresponding to each of the above-described examples of the present invention and the conventional example, and a detailed description thereof will be omitted.

As shown in FIG. 16, the vacuum drive pump 51 of this embodiment is also not provided with the on-off valve 64 of the embodiment shown in FIGS. As shown in FIG. 17, in the vacuum drive pump 51 of this example, the mounting portion 66 a of the piston rod 66 is slidably and airtightly fitted into the hole 95 of the first housing 52, and At the same time, an atmosphere chamber 96 communicating with the atmosphere is formed.

Further, the mounting portion 66a of the piston rod 66
A space is also formed therein, and a valve rod 97 is provided so as to pass through the space and slidably pass through the mounting portion 66a in the axial direction. This valve rod 97 is provided with a connecting rod portion 97a similar to the connecting rod portion 82c shown in FIG.
Is connected to the engaging portion 92a of the control piston 92 in exactly the same manner as the connecting rod portion 82c.

Further, a first valve seat 97b is formed on the outer periphery of the valve rod 97 so as to be located in the space.
A second valve seat 98 is formed in the mounting portion 66a so as to be located in the space. In addition, a valve body 99 that can be seated on the first and second valve seats 97b and 98 is provided in the mounting portion 66a in a space. Then, the valve element 99 and the first valve seat 97b
Constitutes a supply valve 100, and the valve element 99 and the second valve seat 98 constitute a discharge valve 101.

In this case, as shown in FIG. 17, the valve element 99 is seated on the first valve seat 97b to close the supply valve 100, and the valve element 99 is separated from the second valve seat 98 to release the discharge valve 101.
Is open, the variable pressure chamber 57 is
, A discharge hole 101 opened,
In addition to being communicated with the constant pressure chamber 58 via a passage hole 103 formed in the mounting portion 66a, the passage is blocked from a passage hole 104 formed in the mounting portion 66a and constantly communicating with the atmosphere chamber 96. Further, the valve element 99 is connected to the second valve seat 98.
When the discharge valve 101 is closed and the valve body 99 is separated from the first valve seat 97b and the supply valve 100 is open, the variable pressure chamber 57 is in the passage hole 102 and the open supply valve 100. , And through the passage hole 104, and communicates with the atmosphere chamber 96, and is cut off from the constant pressure chamber 58.

Further, between the valve rod 97 and the mounting portion 66a, there is provided a leaf spring 105 which operates in a flip-flop manner. When the leaf spring 105 is located at the first position shown on the left side of the support portion with the attachment portion 66a, the supply valve 1
00 is closed and the discharge valve 101 is opened, and the two valves 100 and 101 are turned upside down so that the supply valve 100 is opened and the discharge valve 101 is closed when in the second position on the right side of the support portion with the mounting portion 66a. Is controlled.

The valve body 99 is constantly urged by the spring force of the spring 106 in the direction of sitting on the first and second valve seats 97b and 98. The other configuration of the vacuum drive pump 51 of this example is the same as the configuration shown in FIG.

Next, the operation of the thus-configured vacuum drive pump 51 of this embodiment will be described. When not operating, the vacuum drive pump 51 is in the state shown in FIG. That is, since no sump pressure is generated, the control piston 92 does not operate. Therefore, the valve rod 97 does not operate, the supply valve 100 is closed, and the discharge valve 101 is open. Leaf spring 10
5 also does not perform the flip-flop operation and is held at the illustrated first position. In this state, the atmosphere does not flow into the variable pressure chamber 57, and the negative pressure of the constant pressure chamber 58 is supplied to the variable pressure chamber 57 because the variable pressure chamber 57 and the constant pressure chamber 58 communicate with each other.
The two chambers 57 and 58 have the same pressure, and the diaphragm piston 55 does not operate. Since no sump pressure is generated even when the ABS control is not performed during the brake operation, the vacuum drive pump 51 is not driven while maintaining this state.

When the ABS control is performed, the sump device 10
When the sump pressure rises to a predetermined pressure, the control piston 92 strokes rightward in FIG. 17, so that the valve rod 97 also moves rightward relative to the mounting portion 66a. By the movement of the valve rod 97, the leaf spring 105 is inverted and the flip-flop is operated to the second position. As a result, the valve body 99 is seated on the second valve seat 98 and the discharge valve 101 is closed, so that the communication between the variable pressure chamber 57 and the constant pressure chamber 58 is cut off,
Since the valve seat 97b is separated and the supply valve 100 is opened, the atmosphere is released from the atmosphere chamber 96 through the passage hole 104, the opened supply valve 100,
And flows into the transformation chamber 57 through the passage hole 102. As a result, a pressure difference is generated between the two chambers 57 and 58, and the diaphragm piston 55 and the piston rod 66 move forward. As a result, the brake fluid in the cylinder hole 65 becomes MC
Discharged to Y5.

When the connecting rod portion 97a of the valve rod 97 comes into contact with the stopper 91 when the piston rod 66 moves forward, the valve rod 97 is prevented from further moving forward. Moves to the right, that is, the valve rod 97 is
Move to the left relative to. For this reason, the leaf spring 1
05 is set to the first position by inversion.
, The valve rod 97 moves further leftward relative to the mounting portion 66a, so that the first valve seat 97b is seated on the valve body 99, the supply valve 100 is closed, and the valve body 99 is The discharge valve 101 is opened by separating from the second valve seat 98. Thereby, the inflow of the atmosphere into the variable pressure chamber 57 is stopped, and the air in the variable pressure chamber 57 flows into the constant pressure chamber 58 through the passage hole 102, the open discharge valve 101, and the passage hole 103. Therefore, there is no pressure difference between the two chambers 57 and 58.

When the pressure difference between the two chambers 57, 58 disappears, both the piston rod 66 and the diaphragm piston 55 retreat to the left by the spring force of the return spring 67. Due to the retraction of the piston rod 66,
The brake fluid is sucked from the sump devices 10, 10 'through the suction holes 71,
The air is sucked through the suction check valves 73 'and 73'.

When the piston rod 66 retreats, the mounting portion 66a of the piston rod 66 comes into contact with the closing plate 56, and the piston rod 66 returns to the inoperative position. But,
Since the sump pressure is acting on the control piston 92, the control piston 92 moves the valve rod 97 again to close the discharge valve 101 again and open the supply valve 100 again. As a result, the atmosphere flows into the variable pressure chamber 57 as described above, the diaphragm piston 55 and the piston rod 66 advance again, and the brake fluid is discharged to the MCY 5. Thereafter, while the control piston 92 is being stroked by the sump pressure, the piston rod 66 repeats the reciprocating motion in this way, and repeats the discharge and suction of the brake fluid.
Circulates the brake fluid in the sump devices 10, 10 'to the MCY 5.

When the ABS control is completed, the sump pressure decreases, so that the control piston 92 returns to the inoperative position, and the discharge valve 101 opens and the supply valve 100 closes. As a result, the air stops flowing into the transformation chamber 57,
The atmosphere in the variable pressure chamber 57 is discharged to the vacuum source 46 through the discharge valve 101 and the constant pressure chamber 58, and the driving of the vacuum drive pump 51 stops. The other configuration and operation and effect of the ABS 2 of this embodiment are the same as those of the above-described embodiments.

FIG. 18 shows a first solenoid on-off valve 14 for introducing air used in still another example of the ABS of the present invention.
(A) is sectional drawing which shows an ON state, (b) is sectional drawing which shows an OFF state.

As shown in FIGS. 18A and 18B,
The first solenoid on-off valve 14 of the present embodiment includes a plunger 108 that is operated by excitation of a solenoid 107, and a first valve portion 109 is provided at a lower end of the plunger 108. Further, below the plunger 108, the valve 1
10 are provided. The valve body 110 is provided with a first valve seat 111 on which the first valve portion 109 can be seated, and also provided with a second valve portion 112. Further, a second valve seat 113 on which the second valve portion 112 can be seated is provided below the valve body 110. The first valve portion 109 and the first valve seat 111 constitute a first valve 114, and the second valve portion 112 and the second valve seat 113 constitute a second valve 115. Further, the plunger 108
The first valve portion 109 is provided between the first valve seat 1 and the valve body 110.
First spring 11 constantly biased in the direction away from 11
6, and a second spring 117 that constantly biases the second valve portion 112 in a direction away from the second valve seat 113 is provided. In that case, the second spring 1
The spring force of 17 is set larger than the spring force of the first spring 116.

The first valve 11 is located at the center of the valve body 110.
4 and a vertical passage hole 110a communicating with the valve body 11 is formed.
0, a lateral passage hole 110b communicating with the outside is formed.

Further, the valve element 1 of the first solenoid on-off valve 14 of this embodiment
A rectifying material 118 made of a mesh coarser than a normal silencing material mesh is provided in 10, so that the rectifying material 118 is located in a wide space near the downstream side of the second valve 115. I have. Further, the first solenoid on-off valve 14 is provided with an air inlet 119 that opens to the atmosphere and an air outlet 120 that is connected to 47 of the negative pressure booster 4.

In the first solenoid on-off valve 14 of the present embodiment having the above-described configuration, the A and the A during the non-operation and during the normal braking are set.
When the BS control is not performed, the off state shown in FIG. 18B is set. In this off state, the solenoid 107 is not excited and the second and
The plunger 108 and the valve element 110 are both located at the upper limit position by the respective spring forces 6,117. Then, the first valve portion 109 is seated on the first valve seat 111 and the first valve 114 is closed, and the second valve portion 112 is separated from the second valve seat 113 and the second valve 115 is opened. I have. Therefore, the atmosphere inlet 119 and the atmosphere outlet 120 communicate with each other, so that the atmosphere can be introduced into the negative pressure booster 4.

When the pressure in the ABS control is reduced, the solenoid 107 is excited and the first solenoid on-off valve 14 is turned on. For this reason, the plunger 108 moves down and pushes down the valve element 110, so that the second valve portion 112 is seated on the second valve seat 113 as shown in FIG.
15 is also closed. Therefore, the air inlet 119 and the air outlet 120 are shut off. At the time of this pressure reduction, the second electromagnetic opening / closing valve 15 is also turned on, and the variable pressure chamber 24 and the constant pressure chamber 23 are communicated with each other.
The vacuum of the transformer chamber 24 is connected to the 47 of the negative pressure booster 4 and the atmosphere outlet 1 of the first solenoid on-off valve 14.
Through the passage 20, it is also introduced into the space where the flow regulating material 118 is located downstream of the second valve 115. However, this vacuum does not leak to the atmosphere because the second valve 115 is closed.

When the pressure in the ABS control is increased or the pressure in the ABS control is increased or the ABS control is terminated, the solenoid 107 is de-energized, and the first solenoid on-off valve 14 is set from the on state to the off state. For this reason, the plunger 108 moves upward by the spring force of the first spring 116. However, at this time, the atmospheric pressure acts on the upper surface of the valve element 110, and the lower surface of the valve element 110 surrounded by the second valve seat 113 (the valve facing the space where the rectifying material 118 is located) as described above. Vacuum pressure acts on the surface of the body 110), and a pressure difference is generated between the upper and lower surfaces of the valve body 110. Since the force for pushing down the valve body 110 due to this pressure difference is larger than the spring force for pushing up the valve body 110 by the second spring 117, the valve body 110 does not move upward. Therefore, the first
The valve portion 109 is separated from the first valve seat 111 and the first valve 114
Opens, but the second valve 115 remains closed.

As a result, first, a relatively small amount of air flows through the opened first valve 114, the vertical passage hole 110a in the center of the valve body 110, and the horizontal passage hole 110b in the valve body 110.
Through the air outlet 120. The pressure difference between the upper and lower surfaces of the valve element 110 is reduced by the flow of the atmosphere, and the force for pushing down the valve element 110 due to the pressure difference becomes smaller than the force for pushing up the valve element 110 due to the spring force of the second spring 117. , The valve element 110 also moves upward, the second valve portion 112 is separated from the second valve seat 113, and the second valve 115 is opened. At this time, the first valve seat 111 is seated on the first valve portion 109, the first valve 114 is closed, and finally the first electromagnetic on-off valve 1
4 is turned off as shown in FIG.

When the second valve 115 is opened, a large amount of air
Since the gas flows from the narrow gap between the valve portion 112 and the second valve seat 113 into a wide space on the side of the air outlet 120, the flow may be disturbed and fluid noise may be generated. However, in the first solenoid on-off valve 14 of the present embodiment, since the rectifying material 118 is provided in this large space, the rectifying material 118 is provided.
Accordingly, the flow of the air that has passed through the gap of the second valve is not disturbed, and almost no fluid noise is generated. Moreover, since the mesh of the rectifying member 118 is coarser than the mesh of the normal silencing member, the flow of the atmosphere is not greatly reduced, and the responsiveness of the first solenoid on-off valve 14 is good. In the above-described example, the fluid pressure drive pump of the present invention is used for the ABS, but is not limited to the ABS and can be used for various fluid circuits.

[0138]

As is clear from the above description, according to the fluid pressure driven pump of the present invention, a motor for driving the pump is not required, and the pump is driven in accordance with the stroke of the piston or the piston rod. By switching the control valve that controls the supply and discharge of fluid pressure to and from the variable pressure chamber, the piston rod reciprocates self-excitingly, eliminating the need for an electromagnetic valve. The noise can be reduced, and the noise can be further reduced.

Further, according to the anti-skid brake control system of the ninth and tenth aspects of the present invention, the motor-driven pump used in the conventional ABS, the motor and the solenoid valve are not required, so that the ABS is not required. A simple and inexpensive configuration can be achieved, and noise during ABS control can be reduced.

Since the brake fluid discharged from the brake cylinder is returned to the master cylinder side, the amount of the brake fluid sent from the master cylinder to the brake cylinder can be reduced, and the capacity of the low-pressure accumulator can be reduced. .

[Brief description of the drawings]

FIG. 1 is a diagram schematically showing an example of an embodiment of an anti-skid brake control system according to the present invention.

FIG. 2 is a longitudinal sectional view of the negative pressure booster shown in FIG.

FIG. 3 is a longitudinal sectional view of the vacuum drive pump shown in FIG.

FIG. 4 is a diagram showing operation control means of the vacuum drive pump shown in FIG.

FIG. 5 is a view showing an operation control means and a connection rotary shaft of the vacuum drive pump shown in FIG. 3;

6A and 6B show a part of the operation of the operation control means of the vacuum drive pump shown in FIG. 3; FIG. 6A is a diagram partially showing the vacuum drive pump of one system, and FIG. It is a figure which shows a drive pump partially.

7A and 7B show another part of the operation of the operation control means of the vacuum drive pump shown in FIG. 3; FIG. 7A is a view partially showing a vacuum drive pump of one system, and FIG. FIG. 2 is a view partially showing the vacuum drive pump of FIG.

8A and 8B show still another part of the operation of the operation control means of the vacuum drive pump shown in FIG. 3, wherein FIG. 8A is a view partially showing a vacuum drive pump of one system, and FIG. It is a figure which shows partially the vacuum drive pump of a system.

9A and 9B show still another part of the operation of the operation control means of the vacuum drive pump shown in FIG. 3, wherein FIG. 9A is a view partially showing the vacuum drive pump of one system, and FIG. It is a figure which shows partially the vacuum drive pump of a system.

10A and 10B show still another part of the operation of the operation control means of the vacuum drive pump shown in FIG. 3, wherein FIG. 10A is a view partially showing a vacuum drive pump of one system, and FIG. It is a figure which shows partially the vacuum drive pump of a system.

11A and 11B show the rest of the operation of the operation control means of the vacuum drive pump shown in FIG. 3, wherein FIG. 11A is a diagram partially showing the vacuum drive pump of one system, and FIG. 11B is a diagram showing the vacuum drive of the other system; It is a figure which shows a pump partly.

FIG. 12 is a diagram schematically showing another example of the embodiment of the anti-skid brake control system according to the present invention.

FIG. 13 is a longitudinal sectional view of the vacuum drive pump shown in FIG.

FIG. 14 is a diagram schematically showing still another example of the embodiment of the anti-skid brake control system according to the present invention.

15 is a longitudinal sectional view of the vacuum drive pump shown in FIG.

FIG. 16 is a view schematically showing still another example of the embodiment of the anti-skid brake control system according to the present invention.

17 is a longitudinal sectional view of the vacuum drive pump shown in FIG.

FIGS. 18A and 18B show a first electromagnetic on-off valve used in still another example of the embodiment of the anti-skid brake control system according to the present invention, wherein FIG. 18A is a cross-sectional view in an on state, and FIG. It is sectional drawing.

FIG. 19 is a diagram schematically illustrating an example of a conventional brake system including an ABS.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Brake system, 4 ... Negative pressure booster, 5 ... Master cylinder (MCY), 7 ... ABS control holding valve, 8 ... Wheel cylinder (W / C), 9 ... ABS control pressure reducing valve,
Reference numeral 10: sump device, 14: normally open first solenoid on-off valve, 15
.., A normally closed second electromagnetic on-off valve, 45, a negative pressure introducing pipe, 46, a vacuum source, 50, an inter-room connection passage, 51, a vacuum drive pump, 52, a first housing, 53, a second housing, 55, a diaphragm Piston, 56 ... closing plate, 57
... variable pressure chamber, 58 ... constant pressure chamber, 60 ... control valve, 60a ... valve spool, 61 ... switching means, 62 ... ball valve, 63 ...
Control piston, 64: open / close valve, 65: cylinder hole, 66
... Piston rod, 66a ... Mounting part, 67 ... Return spring, 69,70 ... O-ring, 71 ... Suction hole, 7
2 ... Discharge port, 73 ... Suction side check valve, 74 ... Discharge side check valve, 75 ... Crank, 75a ... First crank pin, 75b ... Second crank pin, 76 ... Connecting rod, 77 ... First connecting rod, 78 … The second connecting rod,
79: connecting rotary shaft, 80: first communicating path, 81: second communicating path, 82: valve element, 82c: connecting rod part, 83: discharge valve, 83a: valve part, 83b: valve seat, 88: supply valve , 88
a: valve element, 88b: valve seat, 91: stopper, 92: control piston, 92a: locking portion, 94: locking ring, 95 ...
Hole, 96 ... Atmosphere, 97 ... Valve rod, 97b ... First
Valve seat, 98 ... second valve seat, 99 ... valve body, 100 ... supply valve,
101: discharge valve, 103, 104: passage hole, 105: leaf spring

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] September 6, 1996

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] All figures

[Correction method] Change

[Correction contents]

FIG.

FIG. 2

FIG. 3

FIG. 4

FIG. 5

FIG. 6

FIG. 7

FIG. 8

FIG. 9

FIG. 10

FIG. 11

FIG.

FIG. 13

FIG.

FIG. 14

FIG.

FIG. 16

FIG.

FIG.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Hiroyuki Oka 2-11-6 Shinmeicho, Higashimatsuyama-shi, Saitama Automobile Equipment Co., Ltd. Matsuyama Plant

Claims (10)

[Claims] 1. A fluid pressure source, a constant pressure chamber and a variable pressure chamber are defined, and a piston is operated by supplying a fluid pressure from the fluid pressure source to the variable pressure chamber. A piston rod for pumping by repeatedly sucking and discharging a fluid by reciprocating by operation, a control valve for selectively switching the variable pressure chamber to the fluid pressure source or the constant pressure chamber for communication control, and the piston Or a switching means for controlling switching of the control valve in accordance with a stroke of the piston rod, and a control means for operating the switching means when an instruction pressure is supplied. . 2. The control valve includes a normally closed supply valve that controls communication between the fluid pressure source and the variable pressure chamber, and a normally open discharge valve that controls communication between the variable pressure chamber and the constant pressure chamber. Consisting of
In the non-operation position of the piston or the piston rod, the switching means closes the supply valve and opens the discharge valve when not operated by the control means,
When actuated by the control means, the supply valve is opened and the discharge valve is closed, and at a position where the piston or the piston rod has stroked a predetermined amount, the supply valve is closed and the discharge valve is opened. The fluid pressure driven pump according to claim 1, wherein 3. The switching means selects the switching means between a first position in which the supply valve is closed and the discharge valve is opened and a second position in which the supply valve is opened and the discharge valve is closed. A leaf spring that performs a flip-flop operation that is set and held in a non-operative position of the piston or the piston rod.
When the switching means is not operated by the control means, the switching means is set and held at the first position, and when the switching means is operated by the control means, the switching means is set and held at the second position. 3. The fluid pressure driven pump according to claim 2, wherein said switching means is set and held at said first position at a position where said piston or said piston rod has stroked by a predetermined amount. 4. A fluid pressure source, a constant pressure chamber and a variable pressure chamber are defined, and a piston is operated by supplying a fluid pressure from the fluid pressure source to the variable pressure chamber. A piston rod that performs pumping by repeating suction and discharge of fluid by reciprocating by operation, and normally shuts off the fluid pressure source and the variable pressure chamber so as to communicate with each other when an indicated pressure is supplied. An on-off valve to be controlled; a control valve for selectively switching the variable pressure chamber to the on-off valve or the constant-pressure chamber for communication control; and a switch for controlling switching of the control valve according to a stroke of the piston or the piston rod. And a fluid-driven pump. 5. A normally open supply valve for controlling communication between the fluid pressure source and the variable pressure chamber, and a normally closed discharge valve for controlling communication between the variable pressure chamber and the constant pressure chamber. Consisting of
The switching means opens the supply valve and closes the discharge valve when the piston or the piston rod is in the inoperative position, and closes the supply valve when the piston or the piston rod has stroked a predetermined amount and the discharge valve. 5. The hydraulic pressure driven pump according to claim 4, wherein the hydraulic pump is opened. 6. A fluid pressure source, a constant pressure chamber and a variable pressure chamber are defined and a piston is operated by supplying a fluid pressure from the fluid pressure source to the variable pressure chamber. A piston rod that performs pumping by repeating suction and discharge of fluid by reciprocating by operation, and normally shuts off the fluid pressure source and the variable pressure chamber so as to communicate with each other when an indicated pressure is supplied. An on-off valve for controlling, a control valve for selectively switching the variable pressure chamber to the on-off valve or the constant-pressure chamber for communication control, and controlling switching of the control valve according to a stroke of the piston or the piston rod. First and second hydraulically driven pumps each including switching means for causing the piston rod to stroke during operation, and the switching means of the first hydraulically driven pump. A hydraulic drive pump comprising: interlocking means for interlocking a stage with the switching means of the second hydraulic drive pump. 7. The control valve includes a valve spool that performs a linear motion, and the switching unit converts the linear motion of the piston or the piston rod into a rotary motion, and converts the rotary motion into a linear motion of the valve spool. 7. The fluid pressure driven pump according to claim 6, further comprising a converting crank. 8. The connection means for connecting a crank of the switching means of the first fluid pressure driven pump and a crank of the switching means of the second fluid pressure driven pump and rotating both of these cranks integrally. It is provided with a rotating shaft, and these two cranks have a predetermined phase difference, and are complemented with each other so that even if one of the cranks is at the dead center position, it can be rotated by the rotation of the other crank. The fluid pressure driven pump according to claim 7, wherein: 9. A brake operating member, comprising a constant pressure chamber into which a negative pressure is constantly introduced, and a variable pressure chamber into which a non-operating negative pressure is introduced and an atmosphere is introduced at the time of operation. A control valve is operated to introduce air into the variable pressure chamber, thereby boosting the operating force of the brake operating member and outputting the boosted force. A master cylinder that generates master cylinder pressure;
The master cylinder pressure is introduced to generate a braking force, a low-pressure accumulator from which brake fluid is discharged during anti-skid control, and a low-pressure accumulator that is driven during anti-skid control to drive the low-pressure accumulator. A fluid pressure drive pump that recirculates to the master cylinder side, a normally open first solenoid on-off valve that controls the introduction of the atmosphere to the negative pressure booster, and a direct communication between the constant pressure chamber and the variable pressure chamber. Control normally closed second
An electromagnetic on-off valve, a normally-open third electromagnetic on-off valve provided in a passage connecting the master cylinder and the brake cylinder, and controlling communication and shutoff of the two cylinders; and the brake cylinder and the low-pressure accumulator. A fourth solenoid valve which is provided in a passage connecting the brake cylinder and the low pressure accumulator, and controls a communication and a cutoff between the brake cylinder and the low pressure accumulator, and the fluid pressure driven pump is any one of claims 1 to 5. An anti-skid brake control system, comprising the fluid-pressure driven pump according to any one of the preceding claims. 10. A brake operating member, comprising a constant-pressure chamber into which a negative pressure is always introduced, and a variable-pressure chamber into which a non-operating negative pressure is introduced and an atmosphere is introduced during an operation. A control valve is operated to introduce air into the variable pressure chamber, thereby boosting the operating force of the brake operating member and outputting the boosted force. A two-system master cylinder that generates a master cylinder pressure for each two-brake system, and a brake cylinder that generates a braking force by introducing these master cylinder pressures.
A brake cylinder for each brake system, a low-pressure accumulator for each two-brake system from which the brake fluid of these brake cylinders is discharged during anti-skid control, and a brake fluid for the low-pressure accumulator which is driven during anti-skid control to supply the brake fluid to the master cylinder. A fluid pressure drive pump for every two brake systems that recirculates, a normally open first solenoid on-off valve for controlling the introduction of air to the negative pressure booster, and direct communication between the constant pressure chamber and the variable pressure chamber; A normally closed second solenoid on-off valve for controlling shut-off, and a normally-open second solenoid on-off valve for each of two brake systems provided in a passage connecting the master cylinder and the brake cylinder for controlling communication and shut-off of these two cylinders. (3) An electromagnetic on-off valve, provided in a passage connecting the brake cylinder and the low-pressure accumulator, wherein the brake cylinder and the low-pressure accumulator are provided. A normally-closed fourth electromagnetic opening / closing valve for each two-brake system for controlling communication with and disconnection from the pressure accumulator, and the fluid-pressure-driven pump for each of the two brake systems is provided according to any one of claims 6 to 8. An anti-skid brake control system comprising first and second hydraulic drive pumps, wherein each switching means of the hydraulic drive pump for each of the two brake systems is linked by the switching means.