JPH0840234A - Hydraulic brake device for vehicle - Google Patents

Abstract

PURPOSE:To transmit vacuum to a pump chamber from a slit and surely charge the pump chamber with a brake liquid in case of the vacuum charge with the brake liquid by forming a slit at the seat part of the valve of a plunger shaped pump. CONSTITUTION:As for a plunger-shaped pump, a driving cam 102 is arranged in proximity at one end part of a hole 101 on a body 100. Further, at the other end part of the hole 101, the seat member 104 of a discharge valve 103 is fitted. Further, one end part of the seat member 104 is exposed into a damper chamber 26. At a tapered seat part 105, a spherical valve body 106 is pressed by a coil spring 108 interposed between a retainer 107 engaged with the seat member 104 and the valve body 106. In this case, at the seat part 105, a slit 109 for transmitting vacuum is formed. Accordingly, in case of the vacuum charge with a brake liquid, the vacuum is transmitted to a pump chamber 112 from the slit 109, and the pump chamber 112 is charged with the brake liquid.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The invention of the present application relates to a vehicle hydraulic brake device, and more particularly to a vehicle hydraulic brake device capable of supporting antilock control.

[0002]

A brake for reducing the brake fluid pressure of a wheel brake by selectively letting out the brake fluid in the wheel brake to a low pressure reservoir in a brake fluid passage connecting a pressure chamber of a master cylinder and a wheel brake. A hydraulic pressure control valve means and a motor-driven plunger pump for returning the brake fluid that has flowed out into the low pressure reservoir from the low pressure reservoir to the brake fluid passage are connected, and for a vehicle that is compatible with antilock control. Hydraulic braking devices are well known, for example the Toyota Corona FF.
It is described on pages 4-28 to 4-40 of the manual for the coupe / new model car (issued by Toyota Motor Corporation Service Department on August 4, 1987).

As described in the above-mentioned manual for new-model cars, conventionally, the pump chamber of the plunger type pump is normally isolated from the brake fluid passage by closing the discharge valve and the suction valve. The valve opening pressure of the discharge valve and the suction valve is generally set to several atmospheres from the viewpoint of improving the pump discharge performance.

[0004]

In a vehicle assembling process, a vacuum filling method has recently been adopted as a method for filling a brake fluid in a hydraulic brake device. In this vacuum filling method, after a hydraulic brake device is installed in a vehicle, a device for selectively supplying either one of vacuum and brake fluid (pressurized to several atmospheres) is connected to a master cylinder reservoir. First, vacuum is supplied to bleed air, and then brake fluid is supplied.

The vacuum supplied from the master cylinder reservoir is controlled by actuating the brake fluid pressure control valve or without actuating the brake fluid pressure control valve. It is possible to reach the suction port, but in the configuration where the pump chamber of the plunger type pump is isolated from the brake fluid passage by closing the discharge valve and the suction valve like the conventional device, it does not transmit to the pump chamber. However, there is a problem that the pump chamber cannot be filled with the brake fluid.

The invention of this application aims to solve the above problems.

[0007]

According to a first aspect of the present invention, there is provided a vehicle hydraulic brake device according to the present invention. The brake fluid passage connects the pressure chamber of the master cylinder and the wheel brake. A brake fluid pressure control valve means for selectively reducing the brake fluid pressure of the wheel brake by causing the brake fluid in the wheel brake to flow out to a low pressure reservoir; A hydraulic brake device for a vehicle, to which a motor-driven plunger pump for returning from a reservoir to the brake fluid passage is connected, for vacuum transmission to a seat portion of at least one of a discharge valve and an intake valve of the plunger pump. The small slit is formed.

Further, according to the invention of this application, the hydraulic brake device for a vehicle according to the above-mentioned object, as described in claim 2, has a selective brake fluid passage for connecting the pressure chamber of the master cylinder and the wheel brake. Brake fluid pressure control valve means for reducing the brake fluid pressure of the wheel brake by causing the brake fluid in the wheel brake to flow out to the low pressure reservoir, and the brake fluid flowing out into the low pressure reservoir from the low pressure reservoir In a vehicle hydraulic brake device to which a motor-driven plunger pump for returning to the liquid passage is connected, the piston of the low pressure reservoir is connected to the intake valve of the plunger pump only when the piston is in the initial position. The intake valve is configured to come into contact with the valve body and forcibly open the intake valve.

Further, according to the invention of this application according to the above-mentioned object, the vehicle hydraulic brake device according to the present invention has the brake fluid passage connecting the pressure chamber of the master cylinder and the wheel brake selectively. Brake fluid pressure control valve means for reducing the brake fluid pressure of the wheel brake by causing the brake fluid in the wheel brake to flow out to the low pressure reservoir, and the brake fluid flowing out into the low pressure reservoir from the low pressure reservoir A hydraulic brake device for a vehicle, which is connected to an electric motor driven plunger pump for returning to the liquid passage, only when the plunger of the plunger pump is displaced beyond the discharge stroke end in the discharge direction. Is configured to contact the valve body of the discharge valve to forcibly open the discharge valve,
The sliding resistance of the plunger is set to be larger than the force of the valve closing spring of the discharge valve, and a pressure obtained by subtracting the valve opening pressure of the suction valve of the plunger type pump from the lowest pressure in the low pressure reservoir. The product of the effective pressure receiving cross-sectional area of the plunger is set larger than the sliding resistance.

[0010]

In the vehicle hydraulic brake device having the above-described structure, when the brake fluid is filled by the vacuum filling method, it is supplied from the master cylinder reservoir and is sucked into the discharge port of the discharge valve of the plunger type pump or the suction valve. The vacuum transmitted to the mouth portion is a vacuum transmission slit (of claim 1), an intake valve that is open (of claim 2), or a discharge valve that is open (of claim 3). The brake fluid is filled in the pump chamber by subsequently switching the vacuum supply to the master cylinder reservoir to the brake fluid supply.

According to the first aspect of the present invention, the brake fluid leaks from the vacuum transmission slit during the pump action of the plunger type pump, but the amount thereof is small and the discharge performance of the pump does not deteriorate so much. The pressure control action is obtained. According to the second aspect of the present invention, the brake fluid of the wheel brake flows out to the low pressure reservoir by the operation of the brake fluid pressure control valve, and the piston of the low pressure reservoir is displaced, whereby the forced opening of the intake valve is released and the plunger type. Since the pump is ready to perform the pump action, the desired brake fluid pressure control action can be obtained.

In the third aspect of the present invention, the pressure of the brake fluid at the time of vacuum filling is applied to the pump chamber of the plunger type pump from the low pressure reservoir through the suction valve, and this pressure pushes the plunger toward the drive cam. Since the forced opening of the discharge valve is released and the plunger type pump is ready to perform the pumping action, the desired brake fluid pressure control action is obtained.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a vehicle hydraulic brake device according to the invention of this application will be described with reference to the drawings.

FIG. 1 shows a front left wheel brake and a rear right wheel brake in one of the two pressure chambers of the master cylinder, and a front right wheel brake and a rear left wheel brake in the two pressure chambers of the master cylinder. 2 is a schematic view of a hydraulic pressure path of a first embodiment of a hydraulic brake device for an FF vehicle (front engine / front drive vehicle) connected to the other pressure chamber of FIG. In FIG. 1, the brake operating force applied to the brake pedal 10 is doubled by a negative pressure type booster 11 to obtain a tandem type master cylinder 1.
Added to 2. As well known, the master cylinder 12 has two pressure chambers. Of the four front, rear, left and right wheel brakes 13, 14, 16, 17, the left front wheel brake 13 and the right rear wheel brake 14 are connected via an actuator 15 to one of the two pressure chambers of the master cylinder. The front right wheel brake 16 and the rear left wheel brake 17 are connected to the other pressure chamber of the two pressure chambers of the master cylinder via an actuator 18.

The actuator 15 includes a two-port two-position normally open electromagnetic shut-off valve 19 capable of shutting off the front left wheel brake 13 from one pressure chamber of the master cylinder 12, and one rear pressure wheel brake 14 to one pressure of the master cylinder 12. 2 port 2 position normally open type electromagnetic shutoff valve 20 capable of shutting off from the chamber,
The check valves 21 and 22 arranged in parallel with the electromagnetic cutoff valves 19 and 20 and allowing only the flow of the brake fluid from the wheel brake side to the master cylinder side, and the left front wheel brake 13 in a single low pressure reservoir 23. In the low-pressure reservoir 23, a 2-port 2-position normally-closed electromagnetic shutoff valve 24 that can be connected, a 2-port 2-position normally-closed electromagnetic shutoff valve 25 that can connect the right rear wheel brake 14 to the low-pressure reservoir 23. Brake fluid of a constant volume damper chamber 26 and orifice 27
Through the electromagnetic shutoff valves 19 and 20 and the master cylinder 1
2 and a plunger type pump 28 as a positive displacement pump driven by an electric motor.

The actuator 18 is a normally open type electromagnetic shut-off valve 29 of two ports and two positions capable of shutting off the right front wheel brake 16 from the other pressure chamber of the master cylinder 12 and the left rear wheel brake 17 at the other pressure of the master cylinder 12. 2 port 2 position normally open type electromagnetic shutoff valve 30 capable of shutting off from the chamber,
The check valves 31 and 32, which are arranged in parallel with the electromagnetic cutoff valves 29 and 30 and allow only the brake fluid flow from the wheel brake side to the master cylinder side, and the right front wheel brake 16 are provided in a single low pressure reservoir 33. In the low-pressure reservoir 33, the normally-closed electromagnetic shut-off valve 34 of the 2-port 2-position that can be connected, the normally-closed electromagnetic shut-off valve 35 of the 2-port 2-position that can connect the left rear wheel brake 17 to the low-pressure reservoir 33. The brake fluid of the damper chamber 36 and the orifice 37 of a constant volume.
Through the electromagnetic shut-off valves 29, 30 and the master cylinder 1
2 and a plunger pump 38 driven by an electric motor, which pumps the fluid to a hydraulic pressure path.

A single electric motor 39 drives both plunger pumps 28,38.

Both the plunger type pumps 28 and 38 have the same structure. The details of the plunger type pump 28 are shown in FIG.
Shown in In FIG. 2, the drive cam 102 arranged near the right end of the hole 101 of the body 100 is driven to rotate around the rotation center O by the electric motor 39 of FIG. At the left end of the hole 101, the seat member 1 of the discharge valve 103
04 is inserted and fixed. The left end portion of the seat member 104 is exposed in the damper chamber 26, and the tapered seat portion 1 is provided.
At 05, a spherical valve body 106 is pressed by a compression coil spring 108 stretched between a retainer 107 locked to the seat member 104 and the valve body 106. The seat member 104, the valve body 106, the retainer 107 and the compression coil spring 108 constitute the discharge valve 103, and the seat portion 105 is formed with a vacuum transmission slit 109 according to the invention of this application.

An annular seal member 1 is provided on the right side of the hole 101.
A pump plunger 111 equipped with 10 is slidably fitted. A compression coil spring 113 that presses the right end surface of the pump plunger 111 against the drive cam 102 is disposed in a pump chamber 112 formed between the pump plunger 111 and the seat member 104.

The body 1 is connected to the pump chamber 112.
The seat member 115 fixed to the body 100, the retainer 116 locked to the seat member 115, and the compression coil spring 117 stretched between the retainer 116 and the seat member 115 in the hole 114 formed in the seat member 100. 11
5, the spherical valve body 11 pressed against the tapered seat portion 118
9 is provided.

The low-pressure reservoir 23 is fluid-tightly and slidably fitted in a cylinder formed in the body 100, and forms a brake fluid chamber 121 communicating with the inlet of the intake valve 120 between the cylinder and the upper end of the cylinder. And a compression coil spring 123 that urges the piston 122 in the direction of decreasing the volume of the brake fluid chamber. still,
The chamber in which the compression coil spring 123 is located is at atmospheric pressure.

Solenoid shutoff valves 19, 20, 24, 25, 2
Reference numerals 9, 30, 34 and 35 constitute brake fluid pressure control valve means.

Solenoid shutoff valves 19, 20, 24, 25, 2
9, 30, 34, 35 and the electric motor 39 are electrically operated by an electronic control unit (not shown) so as to avoid locking of the wheels according to the behavior of the wheels during vehicle braking.
As is well known, the electronic control unit detects the behavior of each wheel by a signal from a rotation sensor mounted on each wheel, determines the necessity of reducing or increasing the brake fluid pressure of each wheel brake, and determines the electromagnetic shutoff valve. And the electric motor 39 is operated. Electric motor 39
Is energized from the start to the end of the antilock control to drive the plunger type pumps 28, 38. During vehicle braking, for example, the electromagnetic cutoff valve 19 and the electromagnetic cutoff valve 2
4 is operated, the brake fluid in the wheel brake 13 flows out to the low-pressure reservoir 23, the brake fluid pressure in the wheel brake 13 is reduced, and the operation of the electromagnetic shutoff valve 19 is maintained while the electromagnetic shutoff valve 24 operates. When the operation is released, the outflow of the brake fluid from the wheel brake 13 to the low pressure reservoir 23 is stopped, the brake fluid pressure in the wheel brake 13 is maintained, and the operations of the electromagnetic cutoff valve 19 and the electromagnetic cutoff valve 24 are released. If the brake fluid is applied, brake fluid is pumped from the master cylinder 12 to the wheel brakes 13 and the wheel brakes 13
Brake fluid pressure is increased. The brake fluid that has flowed into the low-pressure reservoir 23 is returned to the master cylinder 12 side by the plunger pump 28 through the damper chamber 26 and the orifice 27.

Now, description will be given of filling the brake fluid into the hydraulic brake apparatus by the vacuum filling method after the hydraulic brake apparatus is assembled to the vehicle in the vehicle assembling process. First, when the vacuum is supplied from the master cylinder reservoir, the vacuum shuts off the solenoid valve 1 which is normally open.
Wheel brakes 13, 1 through 9, 20, 29, 30
4, 16 and 17, and the ventilation in each wheel brake is discharged. At that time, the electromagnetic shutoff valves 24, 25, 34, 35
Is activated (two of the electromagnetic shutoff valves 24, 34 may be actuated), and the vacuum causes the electromagnetic shutoff valves 24, 25, 34,
The air in the low pressure reservoirs 23, 33 is discharged through the low pressure reservoirs 23, 33 through 35.

Further, the vacuum is transmitted to the damper chamber 26 through the orifice 27, is transmitted from the damper chamber 26 to the pump chamber 112 and the hole 114 through the vacuum transmission slit 109, and the air inside the pump chamber 112 and the hole 114 is transmitted. Is discharged. The air in the plunger type pump 38 is discharged similarly to the plunger type pump 28.

After the air in the hydraulic brake system is sufficiently discharged as described above, the brake fluid is pumped into the hydraulic brake system from the master cylinder reservoir in place of the vacuum.

FIG. 3 shows a plunger type pump 28 in the second embodiment. In the second embodiment, the vacuum transmission slit 1 is formed in the seat portion 118 of the intake valve 120.
24, and the vacuum transmission slit is not formed in the seat portion 105 of the discharge valve 103. In this second embodiment, the electromagnetic shutoff valves 24, 25, 34, 3
The vacuum transmitted to the low-pressure reservoirs 23 and 33 through the hole 5 passes through the vacuum transmission slit 124 and the hole 11
4 and the pump chamber 112. The plunger type pump 38 is similar to the plunger type pump 28.

FIG. 4 shows a plunger type pump 28 in the third embodiment. In the third embodiment, the compression coil spring 113 that presses the pump plunger 111 against the drive cam 102 is not installed in the pump chamber 112, and the sliding resistance F of the pump plunger 111 corresponds to that of the compression coil spring 108 of the discharge valve 103. The force is set larger than the force, and the push-up rod 125 formed on the pump plunger 111 causes the discharge valve 10 to be discharged when the pump assembly is completed.
3 can be kept open. As means for pressing the pump plunger 111 against the drive cam 102 in place of the compression coil spring 113, the valve opening pressure P1 of the suction valve 120 is made lower than the lowest pressure P2 of the low pressure reservoir 23, and the pressure difference ΔP (ΔP = P2). -P1)
And the effective pressure receiving cross-sectional area S of the pump plunger 111 are set to be larger than the sliding resistance F. In the third embodiment, when the brake fluid is filled by the vacuum filling method, it is transmitted from the damper chamber 26 to the pump chamber 112 and the hole 114 through the discharge valve 103 in which the vacuum valve is open. In the process of filling with, the pump plunger 111 is slid to the drive cam 102 side against the sliding resistance due to the pressure of the pump chamber, and the discharge valve 103 is closed, but the brake fluid continues to flow from the low pressure reservoir 23 side. Since it is supplied to the pump chamber 112 through the suction valve 120, the pump chamber 112 and the hole 11
4 is filled with brake fluid and pump plunger 11
The numeral 1 is pressed by the drive cam 102.

FIG. 5 shows a plunger type pump 28 in the fourth embodiment. In the third embodiment, the push-up rod 126 formed on the piston 122 of the low-pressure reservoir 23 uses the piston 122 of the low-pressure reservoir 23.
The intake valve 120 is forcibly opened only when the volume of the brake fluid chamber 121 is minimized. When the piston 122 slides due to the brake fluid flowing into the brake fluid chamber 121 of the low-pressure reservoir 23, the forced opening of the intake valve 120 is released.

3 to 5, the same constituent elements as those in the embodiment of FIG. 2 are designated by the same reference numerals as those used in FIG.

The brake fluid pressure control valve means is not limited to the configuration shown in FIG. 1 and can be variously modified.

[0032]

As described above in detail, according to the invention of this application, when the brake fluid is filled by the vacuum filling method, it is supplied from the master cylinder reservoir and the discharge port portion of the discharge valve of the plunger type pump. A vacuum transmission slit (according to claim 1) or a suction valve (according to claim 2) in which the vacuum transmitted to the suction port portion of the suction valve or the suction valve (according to claim 2), or an open discharge valve Since it is transmitted to the pump chamber through (according to claim 3), the pump chamber is filled with the brake fluid by switching the vacuum supply to the master cylinder reservoir to the brake fluid supply thereafter.

[Brief description of drawings]

FIG. 1 is a brake fluid pressure path diagram of a first embodiment of the invention of this application.

FIG. 2 is a view showing a detailed structure of the plunger type pump in FIG.

FIG. 3 is a diagram showing a detailed structure of a plunger type pump of a second embodiment.

FIG. 4 is a diagram showing a detailed structure of a plunger type pump of a third embodiment.

FIG. 5 is a diagram showing a detailed structure of a plunger type pump of a third embodiment.

[Explanation of symbols]

12 ... Master cylinder 19, 20, 24, 25, 29, 30, 34, 35 ...
・ Electromagnetic shutoff valve 23, 33 ... Low pressure reservoir 28, 38 ... Plunger type pump 100 ... Body 102 ... Drive cam 103 ... Discharge valve 104, 115 ... Seat member 105, 118. ..Seat portions 106, 119 ... Valve bodies 107, 116 ... Retainers 108, 117 ... Compression coil springs 109, 124 ... Vacuum transmission slits 125, 126 ... Push-up rods

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Hirohisa Kuwana 2-chome, Asahi-cho, Kariya city, Aichi Aisin Seiki Co., Ltd.

Claims (3)

[Claims] 1. A brake for reducing the brake fluid pressure of a wheel brake by selectively flowing out the brake fluid in the wheel brake to a low pressure reservoir in a brake fluid passage connecting a pressure chamber of a master cylinder and a wheel brake. A hydraulic brake device for a vehicle in which hydraulic pressure control valve means and an electric motor driven plunger pump for returning the brake fluid flowing out into the low pressure reservoir from the low pressure reservoir to the brake fluid passage are connected. A vehicle hydraulic brake device, wherein a small slit for vacuum transmission is formed in at least one seat portion of a discharge valve and a suction valve of a plunger type pump. 2. A brake for reducing the brake fluid pressure of the wheel brake by selectively letting out the brake fluid in the wheel brake to a low pressure reservoir in a brake fluid passage connecting the pressure chamber of the master cylinder and the wheel brake. A hydraulic brake device for a vehicle in which hydraulic pressure control valve means and an electric motor driven plunger pump for returning the brake fluid flowing out into the low pressure reservoir from the low pressure reservoir to the brake fluid passage are connected. Only when the piston of the low-pressure reservoir is in the initial position, the piston comes into contact with the valve body of the intake valve of the plunger type pump to forcibly open the intake valve. Vehicle hydraulic brake system. 3. A brake for reducing the brake fluid pressure of the wheel brake by selectively letting out the brake fluid in the wheel brake to a low pressure reservoir in a brake fluid passage connecting the pressure chamber of the master cylinder and the wheel brake. A hydraulic brake device for a vehicle in which hydraulic pressure control valve means and an electric motor driven plunger pump for returning the brake fluid flowing out into the low pressure reservoir from the low pressure reservoir to the brake fluid passage are connected. Only when the plunger of the plunger type pump is displaced in the discharge direction beyond the discharge stroke end, the plunger contacts the valve body of the discharge valve and forcibly opens the discharge valve. The sliding resistance of the plunger is set to be larger than the force of the valve closing spring of the discharge valve, and the low pressure reservoir is For the vehicle, wherein the product of the pressure obtained by subtracting the valve opening pressure of the intake valve of the plunger type pump from the minimum pressure inside and the effective pressure receiving cross-sectional area of the plunger is set larger than the sliding resistance. Hydraulic brake device.