JPH076579U - Hydraulic control valve for brake hydraulic pressure control - Google Patents

Abstract

(57) [Abstract] [Purpose] A brake that can prevent the leakage of hydraulic fluid and the occurrence of hydraulic lock when not in operation without suppressing the increase in size and cost and without reducing the reliability during failure. Providing hydraulic control valve for hydraulic control. [Structure] A return spring 4d for urging the spool 4 in the direction of decreasing the output hydraulic pressure and a plunger portion 54 provided on one end surface of the spool for increasing the pressure of sucking the spool in the direction of increasing the output hydraulic pressure by a suction force. The solenoid 5 and an end surface of the spool are provided slidably in the axial direction, and an end portion on the projecting side of the solenoid 5 abuts on the stopper 80 to receive the output hydraulic pressure on the other end surface, whereby the output hydraulic pressure is reduced by the pressure receiving reaction force. Of the reaction force piston 64 for pushing back the spool to the hydraulic pressure supply port 11a and the external hydraulic pressure supply source 6 by the sliding of the spool by the urging force of the return spring when the energization solenoid provided on the spool end surface is deenergized. And an opening / closing rod 40 for shutting off the supply fluid pressure communication passage a between.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a hydraulic pressure control valve for controlling a brake hydraulic pressure capable of controlling an output hydraulic pressure with respect to a supply hydraulic pressure, and particularly to a technology for preventing hydraulic fluid from leaking from a gap between a spool and a spool hole.

[0002]

[Prior art]

 Conventionally, as a technique for preventing hydraulic fluid from leaking in a hydraulic control valve for controlling a brake hydraulic pressure, for example, those disclosed in Japanese Utility Model Publication No. 4-4257 or Japanese Patent Application Laid-Open No. 4-107369 are known.

First, a hydraulic pressure control valve for controlling a brake hydraulic pressure disclosed in Japanese Utility Model Publication No. 4-4257 discloses a spool capable of adjusting an output hydraulic pressure by sliding and a housing for slidably accommodating the spool. It was designed to form a metal-to-metal seal that prevents leakage of hydraulic fluid by reducing the clearance between it and the sliding hole.

Further, the hydraulic pressure control valve for brake hydraulic pressure control disclosed in Japanese Patent Application Laid-Open No. 4-107369 is a midway of a flow path connecting an external hydraulic pressure supply source and a hydraulic pressure supply port in the hydraulic pressure control valve. In addition, a solenoid valve that closes the flow path when the power is turned off is provided.

[0005]

[Problems to be solved by the device]

 However, such a conventional hydraulic control valve has the following problems. First, in the one disclosed in Japanese Utility Model Publication No. 4-4257, there is a limit in working to reduce the clearance between the spool and the sliding hole, so that the leakage of the hydraulic fluid is completely eliminated. Therefore, depending on the amount of leakage, the motor of the external hydraulic pressure supply source will be in continuous operation, causing a problem of heat generation.To solve this problem, the motor is operated intermittently. Therefore, it is necessary to increase the capacity of the accumulator, and in addition, the supply fluid pressure constantly acts on the spool, which may cause hydraulic lock.

Further, in the one described in Japanese Patent Laid-Open No. 4-107369, a hydraulic lock can be prevented by a solenoid valve, but by adding a solenoid valve, the hydraulic control valve In addition to increasing size and cost, it also reduces reliability in terms of failure.

The present invention has been made by paying attention to the above-mentioned conventional problems, and suppresses an increase in size and cost, and at the time of non-operation without reducing reliability at the time of failure. It is an object of the present invention to provide a hydraulic pressure control valve for controlling a brake hydraulic pressure, which can prevent the leakage of hydraulic fluid and the occurrence of hydraulic lock.

[0008]

[Means for Solving the Problems]

 In order to achieve the above object, in the hydraulic pressure control valve for brake hydraulic pressure control according to the present invention, the hydraulic pressure control valve is slidably provided in the valve body and is connected to the hydraulic pressure supplied from the external hydraulic pressure supply source. A spool that can regulate the output fluid pressure by connecting either the fluid pressure supply port or the drain port that is connected to the drain tank to the output port, and the return spring that urges the spool to reduce the output fluid pressure. A plunger portion is provided on one end surface of the spool, and a pressure-increasing solenoid that sucks the spool in a direction to increase the output hydraulic pressure by a suction force and an axially slidable end surface of the spool are provided. A reaction piston that pushes back the spool in a direction in which the output fluid pressure is reduced by the pressure receiving reaction force when the protruding side end contacts the stopper and the output fluid pressure is received by the other end surface. An opening / closing rod that is provided on the end face of the pool and that shuts off the communication flow path between the hydraulic pressure supply port and the external hydraulic pressure supply source by sliding the spool by the urging force of the return spring when the pressure-increasing solenoid is de-energized. , Is provided.

[0009]

[Action]

 Since the brake fluid pressure control fluid pressure control valve of the present invention is configured as described above, the spool is slid in the direction in which the output fluid pressure is increased in proportion to the suction force generated by energizing the pressure increase solenoid. It

That is, the spool is arranged at a position where the suction force due to the energization of the pressure-increasing solenoid and the reaction force as the feedback force of the piston, the reaction force of the piston + the urging force of the return spring, are balanced. The output hydraulic pressure is increased in proportion to.

Further, in a state where the pressure-increasing solenoid is de-energized, that is, when the hydraulic pressure control valve is inactive, the opening / closing rod urges the hydraulic pressure supply port and the external hydraulic pressure supply by the urging force of the return spring. The spool is pressed and slid in the direction that blocks the communication flow path with the source, which completely prevents leakage of the supply fluid pressure when it is not operating.

[0012]

【Example】

 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. First, the configuration of the embodiment will be described.

FIG. 1 is a sectional view showing a hydraulic pressure control valve 7 for controlling a brake hydraulic pressure according to an embodiment of the present invention. In the drawing, reference numeral 1 denotes a valve body, and this valve body 1 has a valve hole 1 1 Has been drilled. The valve hole 11 is formed with an annular port 11a for supplying hydraulic pressure and an annular port 11b for drain in order from the left.

The hydraulic pressure supply annular port 11a is connected to the external hydraulic pressure supply source 6 from the supply hydraulic pressure communication passage a via the supply hydraulic pressure liquid passage 14, and the drain annular port 11b is It is connected to the drain tank T from the drain communication passage b via the drain liquid passage 15. The external hydraulic pressure supply source 6 includes a hydraulic pump 6a, a hydraulic pressure sensor 6b for detecting the hydraulic pressure in the hydraulic pressure supply passage 14, and a hydraulic pressure based on a detection signal from the hydraulic pressure sensor 6b. It is composed of a motor control circuit 6c for controlling the drive of the pump 6a and an accumulator 6d for storing the high-pressure liquid discharged from the hydraulic pump 6a.

A valve spool 4 is slidably incorporated in the valve hole 11, and an inner peripheral surface of the valve hole 11 and an outer peripheral surface of the valve spool 4 are arranged so that a clearance between them is 10 μm or less. To form an intermetallic seal. The valve spool 4 has an output annular communication groove 4a at an intermediate position between the hydraulic pressure supply annular port 11a and the drain annular port 11b on the outer periphery of the valve spool 4 with respect to both annular ports 11a and 11b. It is formed in a wrapped state, and variable throttles s and t are formed between the output annular communication groove 4a and the both annular ports 11a and 11b.

An output hydraulic pressure communication passage c is formed on the valve hole 11 side facing the output annular communication groove 4 a, and the output hydraulic pressure communication passage c is connected to each vehicle via the output liquid passage 16. It is connected to the wheel cylinders 3 of the wheel braking system.

That is, when the valve spool 4 is in the neutral position shown in FIG. 1, both variable throttles s and t are in the closed state, and the valve spool 4 is moved from the neutral position to the left in the drawing. When the valve is slid on, the variable restrictor t is closed and the variable restrictor s is opened. As a result, the external hydraulic pressure is supplied from the hydraulic pressure supply annular port 11a side to the output annular communication groove 4a side. Therefore, the hydraulic pressure of the wheel cylinder 3 changes in the increasing direction, and when the valve spool 4 slides to the right in the drawing contrary to the above, the variable throttle t is closed with the variable throttle t closed. As the hydraulic pressure is discharged from the output annular communication groove 4a side to the drain annular port 11b side, the hydraulic pressure of the wheel cylinder 3 changes in a decreasing direction.

A pressure reducing solenoid 5 that slides the valve spool 4 by the suction force generated by energization is provided at the outer peripheral position of the left end of the valve spool 4 in the drawing, and the pressure reducing solenoid 5 is energized. Then, the valve spool 4 is slid to the left in the drawing to increase the hydraulic pressure in the wheel cylinder 3.

The depressurizing solenoid 5 includes a solenoid body portion B, a coil portion K, and a plunger portion 54.

The solenoid body B is fitted to the base 51 fixed to the end surface of the valve body 1 with a bolt 60, an intermediate cylinder 56 fitted and fixed to the base 51, and the intermediate cylinder 56. It is composed of a suction member 58.

The coil portion K includes a coil 53 that generates a magnetic field, a hobbin 55 that is made of a non-magnetic material around which the coil 53 is wound, and a coil casing 52 that covers the outer circumference of the hobbin 55. . The coil portion K is detachably attached to the outer periphery of the solenoid body portion B, and is replaceably attached by a lock nut 72 screwed to the outer periphery of the end portion of the adjusting member 9 described later.

A through hole 57 that forms a plunger chamber 62 having a diameter larger than that of the valve hole 11 is formed in the center of the base 51, and the plunger portion 54 slides in the through hole 57 via the bush 100. It is housed freely. The plunger portion 54 is moved in the radial direction on the outer periphery of the small diameter portion 4b integrally formed at the left end of the valve spool 4 in the drawing by a fixed plug 41 screwed to the tip of the small diameter portion 4b. Although it has a degree of freedom, it is mounted so that its axial movement is restricted.

The attraction member 58, the coil casing 52, the base 51, the bush 100, and the plunger portion 54 are each made of a magnetic material, and these members form a magnetic loop. It has become. A magnetic leakage portion 61 having a triangular cross section is formed on the inner end surface of the attraction member 58 to generate a force to attract the plunger portion 54.

The adjusting member 9 is screwed into the through hole 71 of the suction member 58. A return spring 4d is interposed in a compressed state between the adjusting member 9 and a fixed plug 41 fixed to the tip of the valve spool 4, and the repulsive force causes the valve spool 4 to move to the right in the drawing. It is biased by pressing. Therefore, in a state where the pressure increasing solenoid 5 is not energized, the valve spool 4 is pressed rightward in the drawing, and the output hydraulic pressure of the output hydraulic pressure communication passage c connected to the wheel cylinder 3 is in the atmospheric pressure state. Has become.

An opening / closing rod 40 is provided at the axial center of the right end surface of the valve spool 4 in the drawing to shut off a supply fluid pressure communication passage a that connects the fluid pressure supply annular port 11 a and the external fluid pressure supply source 6. Has been.

That is, on the right end surface of the valve body 1 in the drawing, a sub-valve body 10 that also serves as a back chamber cover that forms the back chamber 10a on the end surface of the valve spool 4 is fastened and fixed by a bolt (not shown). The sub-valve body 10 that faces the right end surface of the valve spool 4 in the drawing in the axial direction is formed with a valve chamber 10b interposed in the middle of the supply fluid pressure communication passage a. The opening / closing rod 40 is slidably and slidably inserted into a through hole 10c formed by penetrating a partition between the valve chamber 10b and the through hole 10c. A valve hole 10d, which constitutes a part of the supply fluid pressure communication passage a and is opened and closed by the axial sliding of the opening / closing rod 40, is formed in the. Therefore, in the state where the pressure increasing solenoid 5 is not energized, the valve spool 4 is pressed rightward in the drawing by the urging force of the return spring 4d, so that the opening / closing rod 40 closes the valve hole 10d. As a result, the supply fluid pressure communication passage a is shut off.

An intermetallic seal is formed between the inner peripheral surface of the through hole 10c and the outer peripheral surface of the opening / closing rod 40 so that the clearance between the through hole 10c and the opening / closing rod 40 is 10 μm or less in diameter. There is.

A stopper pin 80 is provided at the axial center portion of the inner end surface of the adjusting member 9 so as to project toward the end surface of the valve spool 4, and the stopper pin 80 of the valve spool 4 facing the stopper pin 80 faces the stopper pin 80. A piston slide hole 63 communicating with the output hydraulic connection hole d via the output annular communication groove 4a is formed in the end face shaft center portion, and a cylindrical reaction force piston 64 is formed in the piston slide hole 63. Is slidably provided.

Further, the back chamber 10 a and the plunger chamber 62 are communicated with each other via the damping prevention orifices 12, 12 of the valve spool 4 and to the reservoir tank T via the drain communication passage b. It is connected.

A drive current from the solenoid control circuit 13 is applied to the coil 53 of the pressure-increasing solenoid 5, and the solenoid control circuit 13 has a pedaling force for detecting the pedaling force of the brake pedal 2. A detection signal is input from the sensor 17.

Next, the operation of the embodiment will be described. (B) Non-braking Since the drive current from the solenoid control circuit 13 to the pressure increasing solenoid 5 is not output when the brake pedal 2 is not depressed, the axial direction of the brake fluid pressure control fluid pressure control valve 7 is changed. The balance of forces is as shown in the following equation (1). K × Lk> Pp × AL (1) where K is the spring constant of the return spring 4d, Lk is the deflection from the free length of the return spring 4d, and Pp is the supply liquid. The pressure and AL are the supply pressure receiving surface area of the open / close rod 40.

That is, the valve spool 4 is pressed and slid to the right in the drawing by the setting force of the return spring 4d, and as shown in FIG. 2, the variable throttle t is opened while the variable throttle s is blocked. In this state, the hydraulic pressure of each wheel cylinder 3 is reduced to the atmospheric pressure state, and the brake device is in the inoperative state.

When the valve spool 4 is slid to the right in the drawing in this non-operating state, the opening / closing rod 40 closes the valve hole 10d and the supply fluid pressure communication passage a is shut off. The high supply pressure of the fluid does not act on the valve spool 4, and the hydraulic lock is not generated.

Further, since the supply hydraulic pressure does not leak inside the hydraulic pressure control valve 7, the hydraulic pressure of the accumulator 6d can be kept constant, which makes it possible to maintain the hydraulic pump 6a in a non-operating state. The operation of can be completely stopped.

(B) During Braking When the brake pedal 2 is depressed, the pedaling force is detected by the pedaling force sensor 17, and in the solenoid control circuit 13, a current proportional to the pedaling force is applied to the coil 53 of the pressure increasing solenoid 5.

In this way, when a current is applied to the depressurizing solenoid 5, a magnetic loop is formed by the adsorbing member 58, the coil casing 52, the base 51, the bush 100, and the plunger portion 54. An attraction force for sliding the plunger portion 54 to the left in the drawing is generated in the magnetic leakage portion 61 having a triangular cross section formed on the inner end surface of the attraction member 58, whereby the valve spool 4 is provided with the return spring 4d. It is pulled back to the left in the drawing against the power. Then, the axial force balance acting on the valve spool 4 at the start of sliding the valve spool 4 to the left in the drawing is expressed by the following equation (2). K × Lk <Pp × AL + S (2) Note that S is the attraction force of the pressure increasing solenoid 5.

As described above, when the sliding of the valve spool 4 to the left in the drawing is started, first, the valve hole 10d that has been closed by the opening / closing rod 40 is opened so that the supply fluid pressure communication passage a is shut off. Since it is released, the supply hydraulic pressure is supplied to the hydraulic pressure supply annular port 11a, and further, when the valve spool 4 slides, the variable throttle t on the drain annular port 11b side is shut off. The variable throttle s on the side of the hydraulic pressure supply annular port 11a is opened, whereby the output hydraulic pressure on the side of the output annular communication groove 4a is increased and the supply hydraulic pressure to the wheel cylinder 3 is increased.

On the other hand, the output hydraulic pressure on the side of the output annular communication groove 4 a passes through the output annular communication groove 4 a and the piston sliding hole 63, is received by the reaction force piston 64, and the reaction force piston 64 is received. When the sliding of the reaction force piston 64 is restricted by the stopper pin 80, the pressure receiving reaction force of the reaction force piston 64 acts on the valve spool 4 as a feedback force. The valve spool 4 is pushed back to the right in the drawing.

That is, the balance of the axial force acting on the valve spool 4 at this time is expressed by the following equations (3) and (4). K × Lk + K × Xs + Af × Pc = Pp × AL + S (3) K × Xs + Af × Pc = S (4) where Xs is the displacement of the valve spool 4, Af is the pressure receiving area of the reaction piston 64, and Pc is the output hydraulic pressure.

That is, when the balance of the above equation (4) is established, as shown in FIG. 1, both the variable diaphragms s and t are closed, and at this time, the output liquid is The pressure Pc is settled to a hydraulic pressure corresponding to the suction force S of the pressure increasing solenoid 5, and this state is called a settling state.

When the pedaling force of the brake pedal 2 is increased from this settling state, the applied current to the pressure increasing solenoid 5 increases and the suction force S increases, whereby the valve spool 4 moves leftward from the state of FIG. The output hydraulic pressure Pc is increased by sliding to return to the settling state when the balance of the above equation (4) is established. Contrary to the above, when the depression force of the brake pedal 2 is weakened, the applied current to the pressure-increasing solenoid 5 decreases and the suction force S decreases, which causes the valve spool 4 to move to the right from the state of FIG. It slides to reduce the output hydraulic pressure Pc and returns to the settling state when the balance of the above equation (4) is established.

That is, a braking force (output hydraulic pressure Pc) proportional to the stepping force of the brake pedal 2 is obtained.

During this operation, a metal-metal seal is formed between the inner peripheral surface of the valve hole 11 and the outer peripheral surface of the valve spool 4, and the inner peripheral surface of the through hole 10c and the outer peripheral surface of the opening / closing rod 40 are connected to each other. Since the metal-to-metal seal is formed with, the leakage of hydraulic fluid during operation is suppressed to an extremely small level.

As described above, in this embodiment, the effects listed below can be obtained.

By providing the opening / closing rod 40 that shuts off the supply fluid pressure communication passage a by utilizing the sliding of the valve spool 4 by the urging force of the return spring 4d, it is possible to suppress the increase in size and cost of the fluid pressure control valve 7. In addition, it is possible to prevent the leakage of hydraulic fluid and the occurrence of hydraulic lock at the time of non-operation without lowering the reliability at the time of failure.

Since an intermetallic seal is formed on the inner peripheral surface of the valve hole 11 and the outer peripheral surface of the valve spool 4, and on the inner peripheral surface of the through hole 10c and the outer peripheral surface of the opening / closing rod 40, the operation at the time of operation It also becomes possible to suppress liquid leakage.

The embodiment of the present invention has been described in detail above with reference to the drawings. However, the specific configuration is not limited to this embodiment, and the present invention can be made even if there are design changes within the scope not departing from the gist of the present invention. Included in the device.

For example, although the description of the anti-skid control is omitted in the embodiment, the slip state of the tire is detected from the vehicle speed detected by the vehicle speed sensor and the wheel rotation speed detected by the wheel rotation sensor. By controlling the current applied to the pressure reducing solenoid from the solenoid control circuit in accordance with the amount of slip, the braking force on the wheels can be reduced, thereby controlling the amount of slip on the wheels. The wheels can be prevented from locking. Further, when the brake pedal is not operated, a braking force can be generated by applying a current from the solenoid control circuit to the pressure-increasing solenoid, whereby traction control can be performed.

[0049]

[Effect of device]

 As described above, in the brake fluid pressure control valve of the present invention, the spool is slid by the biasing force of the return spring when the energization of the pressure boosting solenoid is released when it is provided on the spool end surface. By providing an opening / closing rod that shuts off the communication flow path between the hydraulic pressure supply port and the external hydraulic pressure supply source, the hydraulic pressure control valve is prevented from increasing in size and cost, and at the time of failure. It is possible to prevent the leakage of hydraulic fluid and the occurrence of hydraulic lock when not in operation without lowering the reliability.

[Brief description of drawings]

FIG. 1 is a sectional view showing a hydraulic pressure control valve for brake hydraulic pressure control according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view of an essential part for explaining the operation of the essential part of the hydraulic pressure control valve for brake hydraulic pressure control according to the embodiment.

[Explanation of symbols]

 1 Valve Body 4 Valve Spool 4d Return Spring 5 Boosting Solenoid 6 External Hydraulic Pressure Supply Source 7 Hydraulic Pressure Control Valve 11a Liquid Pressure Supply Annular Port (Hydraulic Pressure Supply Port) 11b Drain Annular Port (Drain Port) 40 Open / Close Rod 54 Plunger part 64 Reaction force piston 80 Stopper pin (stopper) a Supply fluid pressure communication path (communication flow path) T Drain tank

Claims (1)

[Scope of utility model registration request] 1. An output port which is slidably provided in a valve body and which is connected to a hydraulic pressure supply port from an external hydraulic pressure source or a drain port connected to a drain tank. A spool that can adjust the output fluid pressure by connecting to the spool, a return spring that urges the spool in the direction to reduce the output fluid pressure, and a plunger portion on one end surface of the spool A pressure-increasing solenoid that sucks the spool in the direction that increases the output hydraulic pressure, and an axially slidable spool end surface that has a protruding end that contacts the stopper and receives the output hydraulic pressure on the other end surface. By doing so, the reaction force piston that pushes back the spool in the direction to reduce the output hydraulic pressure by the pressure receiving reaction force, and when the boost solenoid is de-energized when the energization solenoid is released Hydraulic pressure control valve, characterized in that it comprises a and a closing rod for blocking the communication flow path between the sliding of the spool by the biasing force of the return spring and the hydraulic pressure supply port and an external fluid pressure source.