JP2001055129A - Normally open solenoid valve of antilock brake device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a normally open solenoid valve of an antilock brake device for a vehicle, which absorbs pulsation of hydraulic pressure between a brake master cylinder and a wheel brake to prevent generation of vibration and noise. SOLUTION: This normally open solenoid valve includes a valve plunger 16 for opening and closing a valve chest 32 provided in a liquid passage from a brake master cylinder M/C side to the wheel brake side, a damper chamber 35 formed in the interior of the valve plunger 16 to absorb hydraulic pressure from the brake master cylinder M/C side through a communicating hole 34a communicated with the liquid passage, and a movable piston 36 provided in the damper chamber 35, energized in the direction of reducing the capacity of the damper chamber 35 and moved in the direction of enlarging the capacity of the damper chamber 35 by hydraulic pressure from the brake master cylinder M/C side at the time of operation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle which is provided in a hydraulic circuit of an anti-lock brake device for a vehicle, opens a valve so that a brake master cylinder and a wheel brake communicate with each other, and closes magnetically when energized. The present invention relates to a normally-open solenoid valve of an anti-lock brake device.

[0002]

2. Description of the Related Art In an anti-lock brake device for a vehicle, a normally open solenoid valve and a normally closed solenoid valve are provided for each wheel brake in a hydraulic circuit that connects a brake master cylinder and a wheel brake. Have been. These solenoid valves provide a pressure increase mode in which the fluid path between the brake master cylinder and the wheel brake is communicated but the fluid path between the wheel brake and the reservoir is interrupted. Either of the depressurization mode in which the fluid path between the brake and the reservoir communicates, the holding pressure mode in which the fluid path between the brake master cylinder and the wheel brake, and the fluid path between the wheel brake and the reservoir are both shut off, will be one of the states according to the brake state The flow of the brake fluid is controlled by opening and closing each solenoid valve as described above. These solenoid valves include a valve operating unit that opens and closes the valve, and a coil unit that operates the valve operating unit by controlling energization of a coil winding wound around a bobbin. The energization of the coil unit is controlled by an electronic control unit (ECU).

The configuration of a general normally-open solenoid valve will be described. A valve operating unit includes a fixed core, a movable core, a valve plunger, and a valve seat in a valve housing in which a base end of a guide cylinder is connected to a housing body. A member, a return spring, and the like are provided. The valve actuating unit is fitted into a metal base on which a flow path for the brake fluid is formed (see, for example, Japanese Patent Application Laid-Open No. 9-119549).

[0004] A valve plunger having a valve body at the tip and a valve seat member having a valve hole at the tip are valve-opened to transmit hydraulic pressure from the brake master cylinder side to each wheel brake side in the pressure increasing mode. are doing. When the mode shifts to the holding pressure mode and further to the pressure reduction mode, the electronic control unit energizes and energizes the coil unit, and pushes the valve plunger toward the valve seat member by the movable core to close the valve body and the valve hole. Shut off the fluid path between the brake master cylinder and the wheel brake.

[0005]

In the normally-open solenoid valve disclosed in the above prior art, when the valve plunger (valve shaft) is closed to shift from the pressure increasing mode to the holding pressure mode and further to the pressure reducing mode. However, when a high hydraulic pressure is continuously applied from the brake master cylinder side, the hydraulic pressure to each wheel brake side may pulsate or vibration may be transmitted to the brake pedal side.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art, and to absorb an pulsation of hydraulic pressure between a brake master cylinder and a wheel brake to prevent vibration and abnormal noise from occurring. To provide a normally-open solenoid valve.

[0007]

To solve the above-mentioned problems, the present invention has the following arrangement. That is, a vehicle which is provided in a hydraulic circuit of an anti-lock brake device for a vehicle and which is normally opened so as to communicate a brake master cylinder and a wheel brake, and which is operated to close a valve by energizing a coil unit by energizing a coil unit. In the normally open solenoid valve of the anti-lock brake device, the valve operating unit is connected to a valve plunger that closes a valve chamber provided in a fluid path from the brake master cylinder side to the wheel brake side, and a communication that communicates with the fluid path. A damper chamber formed inside the valve plunger so as to be able to absorb the hydraulic pressure from the brake master cylinder side through the hole, and a damper chamber are provided, and are urged in a direction to reduce the volume of the damper chamber. A movable piston that moves in a direction in which the volume of the damper chamber is expanded by the hydraulic pressure from the brake master cylinder side. Further, an orifice is provided in a liquid path to the wheel brake side communicating with the valve chamber, and a back side of a movable piston provided in the damper chamber is connected to a liquid path between the valve chamber and the orifice. .

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. This embodiment describes a normally-open solenoid valve provided between a brake master cylinder and a wheel brake of a hydraulic circuit of an antilock brake device for a vehicle. 1 is a cross-sectional view of a normally-open solenoid valve in a pressure increasing mode, FIG. 2 is a cross-sectional view of a normally-open solenoid valve in a holding pressure mode and a depressurizing mode, and FIG. 4, FIG. 4 is a partial cross-sectional view near the valve plunger of the normally-open solenoid valve of FIG. 2, and FIG. 5 is a graph showing the change over time of the hydraulic pressure on the brake master cylinder side and the wheel brake side in the holding pressure mode. FIG. 6 is a configuration diagram schematically showing an anti-lock brake device for a vehicle.

First, a schematic configuration of an antilock brake device for a vehicle will be described with reference to FIG. Reference numeral 1 denotes an electronic control unit (ECU) that controls the operation of a hydraulic circuit that constitutes the actuator 2. M / C is a brake master cylinder which is connected to a hydraulic circuit of the actuator 2 and outputs a brake hydraulic pressure from each cylinder chamber according to the depression amount of a brake pedal (not shown). Fl, Rr, Rl,
Fr is a front left wheel, a rear right wheel, a rear left wheel, and a front right wheel. Each wheel has a wheel brake B (Fl), B
(Rr), B (Rl), and B (Fr) are provided. A wheel cylinder for operating each wheel brake is connected to a hydraulic circuit of the actuator 2.

[0010] The structure of the actuator 2 will be described.
(Fl), normally open input valves IV (Fl), IV (Rr) connected to each wheel cylinder of B (Rr), and wheel brakes B (Rl), connected to each wheel cylinder of B (Fr). Normally open input valves IV (Rl), IV
(Fr). For each of these four input valves, normally closed output valves OV (Fl), OV (Rr),
OV (Rl) and OV (Fr) are connected in parallel. The output valves OV (Fl) and OV (Rr) are connected to the reservoir 3 for temporarily storing the brake fluid, and the output valve OV (R
1) and OV (Fr) are connected to a reservoir 4 for temporarily storing brake fluid.

The reservoirs 3, 4 are connected to the suction ports of plunger pumps 5, 6, and the plunger pumps 5, 6 circulate the brake fluid from the reservoirs 3, 4 so as to return to the brake master cylinder M / C. Let it. Reference numeral 7 denotes a pump operating motor. When the motor is rotated, the piston reciprocates to operate the plunger pumps 5, 6.

Normally open input valves IV (Fl), IV
(Rr), IV (Rl) and IV (Fr) are opened and closed by solenoid valves driven by solenoids, and the opening and closing operation of each input valve is controlled by the electronic control unit 1. Also, normally closed output valves OV (Fl), OV
(Rr), OV (Rl) and OV (Fr) are opened and closed by solenoid valves driven by solenoids, and the opening and closing operation of each output valve is controlled by the electronic control unit 1. Also, normally open input valves IV (Fl), IV
Check valves 8 (Fl), 8 (Rr), 8 (Rl), and 8 (Fr) are connected in parallel to (Rr), IV (Rl), and IV (Fr), respectively.
/ C is released, the corresponding wheel brake B
From (Fl), B (Rr), B (Rl), B (Fr),
The valve is opened to return the brake fluid to the brake master cylinder M / C instantaneously.

The electronic control unit 1 controls each wheel Fl, R
The running state of the vehicle is input from a wheel speed sensor (not shown) provided at r, Rl, Fr. The electronic control unit 1 controls each wheel brake B (F
l), B (Rr), B (Rl), and B (Fr) for each normally open input valve IV (Fl), IV (Rr), IV
(Rl) and IV (Fr) are opened, and each normally closed type output valve OV (Fl), OV (Rr), OV (Rl), O
V (Fr) is closed to increase the braking pressure by increasing the hydraulic pressure applied from the brake master cylinder M / C to the wheel cylinder (not shown) to increase the braking torque. Each normally open input valve IV ( Fl), IV (Rr), IV (R
l), IV (Fr) and each normally closed output valve OV
(Fl), OV (Rr), OV (Rl), OV (Fr)
Is closed to prevent the hydraulic pressure from being transmitted from the brake master cylinder M / C to the wheel cylinders (not shown) to maintain the braking torque. (Rr), IV (Rl), IV
(Fr) is closed, and each normally closed output valve OV (F
l), OV (Rr), OV (Rl) and OV (Fr) are opened, and the reservoir 3 is opened from a wheel cylinder (not shown).
4, the brake fluid is temporarily stored, and the brake fluid is controlled by one of pressure reduction mode commands to reduce the braking torque so that the wheels are not locked. Of these,
When shifting to the depressurization mode, the electronic control unit 1 drives the pump operating motor 7 so that the plunger pump 5,
6, the brake fluid temporarily stored in the reservoirs 3 and 4 is returned to the brake master cylinder M / C side.

The input valves IV (Fl), IV (Rr),
Normally open solenoid valve V for opening and closing IV (Rl), IV (Fr)
The schematic configuration of o will be described with reference to FIG. Although four normally open solenoid valves Vo are provided, one of them will be described as a representative. The normally-open solenoid valve Vo includes a valve operating unit 9 for opening and closing the valve, and a coil unit 1 for operating the valve operating unit 9 by energization.
0.

The valve operating unit 9 includes a valve housing 13 in which a base end of a guide cylinder 11 is welded to a housing body 12.
Inside, a fixed core 14 and a movable core 15 are provided.
In the fixed core 14, a valve plunger 16, a valve seat member 17,
The check valve 8 and the return spring 18 are provided.
The valve operating unit 9 is fitted into the fitting hole 21 of the metal base 20 in which the fluid path 19 for the brake fluid from the brake master cylinder side is formed, and is released by the retaining ring 22 engaged with the concave groove on the inner wall of the hole. Not to be. Seal rings 23 and 24 are fitted around the outer periphery of the valve housing 13, and an annular chamber 25 communicating with the wheel brake is formed between the seal rings 23 and 24. The check valve 8 is opened to return the brake fluid from the wheel brake side to the brake master cylinder side when an operation of returning the brake pedal is performed. Also, the valve housing 1
A filter 26 is arranged and mounted on the outer periphery of 3 so as to be accommodated in the annular chamber 25.

In the coil unit 10, a connection terminal 28 having electrical conductivity is fixed to one side of a bobbin 27 made of an insulating resin material or the like in a direction in which the connection terminal 28 is suspended from the bobbin 27. A coil winding 29 wound around the bobbin 27 is connected to the connection terminal 28. A cylindrical yoke 30 is fitted on the bobbin 27, and a magnetic path plate 31 is fitted into an upper opening of the yoke 30, and these form a magnetic path. The connection terminal portion 28 is connected to a conductor plate (not shown) electrically connected to the electronic control unit 1 by welding (for example, projection welding). The coil unit 10 is disposed so that the guide cylinder 11 of the valve operating unit 9 fits into the center hole 27 a of the bobbin 27 and the center hole 31 a of the magnetic path plate 31. The yoke 30 is externally fitted to the bobbin 27, and the lower end opening is externally fitted to the housing body 12.

Next, the configuration of the valve operating unit 9 will be described in detail. The movable core 15 is in contact with the upper end of the valve plunger 16, and when the coil unit 10 is energized, pushes the valve plunger 16 to close the fluid path from the brake master cylinder M / C to the wheel brake.

The lower end of the valve plunger 16 and the valve seat member 17
A valve chamber 32 is formed between the two. The valve seat member 17 has a valve hole 17a and a fluid passage 33, which communicate with the fluid passage 19 on the brake master cylinder M / C side. An opening is formed at the lower end side of the valve plunger 16, and a cylindrical valve rod 34 having a smaller diameter than the valve plunger 16 is press-fitted and fixed coaxially to the opening. A return spring 18 is elastically mounted between the lower end surface of the valve plunger 16 and the upper end surface of the valve seat member 17, and the valve plunger is normally opened such that the space between the valve rod 34 and the valve seat member 17 is open. 16 is urged upward.

The internal space surrounded by the valve rod 34 and the valve plunger 16 is a damper chamber 35, which absorbs the hydraulic pressure from the brake master cylinder M / C side. In the center of the tip of the valve rod 34, a damper chamber 35 and a valve chamber 3
A communication hole 34a that communicates with the second valve hole 17a is formed. Liquid passage 19, liquid passage 33, valve hole 17a, valve chamber 32, communication hole 34a from brake master cylinder M / C side
The damper chamber 35 is arranged linearly.

A movable piston 36 is accommodated in the damper chamber 35. The movable piston 36 is constituted by a piston spring 39 elastically mounted between a piston valve 37 made of an elastic member such as rubber and a damper chamber inner wall 38.
When the piston valve 37 is opened, it is urged downward by a piston spring 39 so as to reduce the volume of the damper chamber 35 and is in pressure contact with the upper end of the valve rod 34. The piston valve 37
When the valve is closed, it moves in the direction of expanding the volume of the damper chamber 35 against the urging force of the piston spring 39 by the hydraulic pressure from the brake master cylinder M / C side.

An orifice 41 is formed in the fluid passage 40 communicating with the valve chamber 32 to the wheel brake side. The fluid passage 40 communicates with the annular chamber 25 and is connected to a wheel cylinder (not shown) on the wheel brake side. A communication hole 42 is formed in the damper chamber wall 38 on the rear side of the piston valve 37, and communicates with a liquid passage 40 between the valve chamber 32 and the orifice 41. When the hole diameter of the valve hole 17a is A, the hole diameter of the communication hole 42 is B, and the hole diameter of the orifice 41 is C, A> B and A> C are formed.

Next, the opening / closing operation of the normally open solenoid valve will be described with reference to FIG.
This will be described with reference to FIGS. In FIG. 5, the hydraulic pressure on the brake master cylinder M / C side is expressed as M / C pressure, and the hydraulic pressure on the wheel brake side is expressed as CAL pressure. When the normally open solenoid valve is in the open state, that is, in the pressure increasing mode in which the fluid paths 19 and 40 on the brake master cylinder M / C side and the wheel brake side are connected, the fluid path 19, the fluid path 33, and the valve Orifice 41 and filter 2 through chamber 32 and liquid passage 40
6, the hydraulic pressure on the wheel brake side is increased, and the braking torque is increased. At this time, the communication hole 3 is provided in the damper chamber 35.
Since the brake fluid is filled from 4a and the fluid pressure is applied to each fluid path at the same pressure, the movable piston 36 is in a stationary state with the piston valve 37 pressed against the upper end of the valve rod 34 as shown in FIG. .

The electronic control unit 1 closes the valve chamber 32 by pushing the valve plunger 16 by the movable core 15 when the coil unit 10 is energized to perform anti-lock control on the wheel brakes according to the brake state. Give a valve. Then, the fluid path 1 on the brake master cylinder M / C side
A holding mode in which the hydraulic pressure is not transmitted from the brake master cylinder M / C to a wheel cylinder (not shown) by shutting off the liquid passage 40 on the wheel brake side, and a braking mode in which the braking torque is maintained, and a normally closed type. By opening each of the output valves OV and temporarily storing brake fluid in the reservoirs 3 and 4 from a wheel cylinder (not shown), a transition is made to a pressure reduction mode in which the braking torque is reduced so that the wheels are not locked. .

In FIG. 4, the valve plunger 16 is depressed against the urging force of the return spring 18 so that the valve rod 34 comes into pressure contact with the valve seat member 17 and the brake master cylinder M / C.
The liquid passages 19 and 33 from the side and the valve chamber 32 are shut off. At this time, when a high fluid pressure is continuously applied from the brake master cylinder M / C side, the fluid path 19 on the brake master cylinder M / C side becomes high pressure instantaneously, and vibration is transmitted to the brake pedal side ( The brake fluid flowing into the wheel brake side pulsates (see broken line R in FIG. 5) (see broken line R in FIG. 5).
See).

In this embodiment, with the valve plunger 16 closed, the valve hole 17a of the valve seat member 17, the communication hole 34a,
When the high hydraulic pressure is continuously applied from the brake master cylinder M / C side because the damper chamber 35 is in communication,
The brake fluid flows into the damper chamber 35 and the movable piston 3
6 against the urging force of the piston spring 39
And moves in the direction of expanding the volume of the damper chamber 35 by the volume corresponding to the hatched portion D shown in FIG. Thus, the pulsation of the brake fluid between the brake master cylinder M / C and the wheel brake can be absorbed, so that the fluid pressure on the wheel brake side can be gradually stabilized from the time of closing the valve (FIG. 5). (See solid line Q), and the transmission of vibration to the brake pedal side can also be suppressed (see solid line P in FIG. 5), and good operability can be maintained.

The rear side of the movable piston 36 provided in the damper chamber 35 has a fluid passage 4 between the valve chamber 32 and the orifice 41 through a communication hole 42 provided in the wall 38 of the damper chamber.
0, the hydraulic pressure in the damper chamber 35 partitioned by the piston valve 37 is maintained at the same pressure at any point in the pressure increase mode, so that the movable piston 36 is immediately returned to the non-operating state. Can be. In addition, since the orifice 41 is provided in the fluid passage 40 communicating with the wheel brake side, the orifice 4 is opened immediately when the valve plunger 16 is opened.
It is possible to make the fluid pressure from 1 to the fluid path 33 constant, which allows the piston valve 37 to return quickly.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and many modifications can be made without departing from the spirit of the invention. Of course.

[0028]

According to the structure of the normally open solenoid valve according to the first aspect of the present invention, the liquid passage from the brake master cylinder side and the damper chamber communicate with each other when the valve plunger is closed.
When a high fluid pressure is continuously applied from the brake master cylinder side, the brake fluid flows into the damper chamber and moves the movable piston in a direction in which the volume of the damper chamber expands. Pulsation can be absorbed. Therefore, the fluid pressure on the wheel brake side can be gradually stabilized after the valve is closed, and the transmission of vibration to the brake pedal side can be suppressed, and good operability can be maintained. According to the configuration of the normally open solenoid valve according to the second aspect, in the pressure increasing mode, the hydraulic pressure in the damper chamber and the hydraulic pressure behind the movable piston are maintained at the same pressure, so that the movable piston can be quickly returned. Becomes Also, by providing an orifice in the fluid path communicating with the wheel brake side, the moment the valve plunger opens,
The fluid pressure from the orifice to the fluid path on the brake master cylinder side can be kept constant, thereby enabling quick return of the piston valve.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a normally-open solenoid valve in a pressure increasing mode.

FIG. 2 is a cross-sectional view of a normally open solenoid valve in a holding pressure mode and a pressure reducing mode.

3 is a partial cross-sectional view of the normally open solenoid valve of FIG. 1 in the vicinity of a valve plunger.

FIG. 4 is a partial cross-sectional view showing the vicinity of a valve plunger of the normally-open solenoid valve of FIG. 2;

FIG. 5 is a graph showing the change over time of the hydraulic pressure on the brake master cylinder side and the wheel brake side in the holding pressure mode.

FIG. 6 is a configuration diagram schematically showing an antilock brake device for a vehicle.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Electronic control unit 2 Actuator 3, 4 Reservoir 5, 6 Plunger pump 7 Pump operation motor 8 (Fl), 8 (Rr), 8 (Rl), 8 (Fr) Check valve 9 Valve operation unit 10 Coil unit 11 Guide Cylinder 12 Housing body 13 Valve housing 14 Fixed core 15 Movable core 16 Valve plunger 17 Valve seat member 17a Valve hole 18 Return spring 19, 33, 40 Liquid path 20 Base 21 Fitting hole 22 Retaining ring 23, 24 Seal ring 25 Annular chamber Reference Signs List 26 filter 27 bobbin 27a, 31a center hole 28 connection terminal portion 29 coil winding 30 yoke 31 magnetic path plate 32 valve chamber 34 valve rod 34a, 42 communication hole 35 damper chamber 36 movable piston 37 piston valve 38 damper chamber wall 39 piston spring 41 orifice

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Naoki Masuda 840 Kokubu, Ueda-shi, Nagano F-term (reference) 3D046 BB07 BB28 CC02 LL23 LL33 LL41 LL51 LL54 3H106 DA07 DA12 DA23 DB02 DB12 DB23 DB32 DC02 DC17 DD05 EE20 GC11 KK22

Claims (2)

[Claims] 1. A valve provided in a hydraulic circuit of an anti-lock brake device for a vehicle, which is normally opened so as to connect a brake master cylinder and a wheel brake, and is operated to close by operating a valve operating unit by energizing a coil unit. A normally open type electromagnetic valve of a vehicular anti-lock brake device, wherein the valve operating unit closes a valve chamber provided in a fluid path from the brake master cylinder side to the wheel brake side; A damper chamber formed inside the valve plunger so as to be able to absorb the hydraulic pressure from the brake master cylinder through a communication hole communicating with the liquid path; and a damper chamber provided in the damper chamber to reduce the volume of the damper chamber. Movable in the direction of expanding the volume of the damper chamber by the hydraulic pressure from the brake master cylinder side during operation. A normally-open solenoid valve for an antilock brake device for a vehicle, comprising a piston. 2. An orifice is provided in a fluid path to the wheel brake side communicating with the valve chamber, and a fluid path between the valve chamber and the orifice is provided on a rear side of the movable piston provided in the damper chamber. The normally-open solenoid valve for an anti-lock brake device for a vehicle according to claim 1, wherein the normally open solenoid valve is connected to the solenoid valve.