JP2529072Y2 - Anti-skid brake device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial application field) The present invention relates to an anti-skid brake for a vehicle that controls a brake fluid pressure supplied to a brake cylinder of a wheel brake device according to a skid state of a wheel of a vehicle or the like. More specifically, the present invention relates to an anti-skid brake device in which brake fluid discharged from a brake cylinder via a hydraulic pressure control valve is pressurized by a hydraulic pump and returned to a hydraulic fluid supply pipe connected to a master cylinder. It is.

(Prior art) Conventionally, while a car is running, on any road surface,
Various anti-skid devices have been developed as brake devices for performing a more effective and safe braking action.

In these anti-skid brake systems, the skid condition of the wheels is evaluated by the control unit,
Based on this evaluation, the brake fluid pressure supplied to the brake cylinder of the wheel is reduced, increased, or kept constant.

FIG. 3 shows a well-known anti-skid brake device. The configuration of this anti-skid brake device will be briefly described with reference to FIG.

In the figure, reference numeral 1 denotes a brake pedal, and the brake pedal 1 is connected to a master cylinder 2. The master cylinder 2 is connected to a hydraulic pump 20 via a hold valve 4, a decay valve 5, and a reservoir 10. An oil passage between the hold valve 4 and the decay valve 5 is connected to a brake cylinder 6 of a wheel.

The hold valve 4 is operated by a signal from the control circuit 8, and when this valve is operated to cut off the communication between the master cylinder 2 and the brake cylinder 6, the hydraulic pressure in the brake cylinder 6 is maintained. The decay valve 5 is operated by a signal from the control circuit 8. When the decay valve 5 is operated, an oil passage between the brake cylinder 6 and the reservoir 10 is opened, and the brake fluid in the brake cylinder 6 is discharged to the reservoir 10.

The reservoir 10 is for storing the brake fluid discharged from the brake cylinder 6, and the brake fluid stored in the reservoir 10 is pressurized by the hydraulic pump 2 and returned to the master cylinder via the check valve 3.

As shown in FIG. 4, the hydraulic pump 20 includes a housing 30, a cylinder member 23, a plunger 22, and ball valves 24 and 25, and is disposed between the cylinder member 23 and the housing 30 of the hydraulic pump 20. It has a hydraulic seal 321. The hydraulic seal 321 is for preventing the brake fluid in the hydraulic pump 20 from leaking into the atmosphere.

Hydraulic pump 20, hold valve 4, decay valve 5
Is controlled by a control circuit 8 that evaluates the skid state of the wheel based on a signal from a sensor 7 provided on the wheel.

In this type of hydraulic pressure control device, when the brake hydraulic pressure of the brake cylinder is reduced, the master cylinder 2
The hold valve 4 as a hydraulic pressure control valve interposed between the hydraulic cylinder and the brake cylinder 6 is closed to cut off the communication with the master cylinder 2, and the decay valve 5 as the hydraulic pressure control valve is opened to open the brake cylinder 6. Is discharged into the reservoir 10. The brake fluid discharged to the reservoir 10 is sucked and pressurized by a plunger 22 of a hydraulic pump 20 which operates simultaneously with the start of the hydraulic control, and the ball valve
It is returned to the pressure liquid supply line connected to the master cylinder 2 via 24.

(Problem to be Solved by the Invention) However, the hydraulic return operation from the reservoir 10 to the brake hydraulic pressure supply line by the hydraulic pump 20 is performed at the same time when the brake fluid is discharged from the brake cylinder 6 to the reservoir 10. Specifically, since the brake fluid returning operation is performed when the hold valve 4 is closed, the hydraulic fluid generated by the hydraulic pump is pulsated with the hydraulic pump 20.
And the seal portion of the hold valve 4. However, since the hydraulic seal of the conventional hydraulic pump 20 and the seal member of the hold valve 4 all have a shape with little change in volume, the pulsation cannot be absorbed, and the pulsation cannot be directly mastered. The pulsation flows into the hydraulic pressure generating chamber of the cylinder 2, and this pulsation causes the piston of the master cylinder to be largely pushed back, and hence the brake pedal to be pushed back, causing a phenomenon called “kickback” which causes discomfort to the driver.

The present invention has been made in order to mitigate the above-mentioned phenomenon.By adopting a hydraulic seal 32 in the hydraulic pump 20 which can absorb the pulsation of the brake hydraulic pressure, the brake discharged to the reservoir during anti-skid control. It is an object of the present invention to provide an anti-skid brake device capable of mitigating a kickback phenomenon to a brake pedal which occurs when a liquid is pressurized by a hydraulic pump and returned to a pressure liquid supply line.

(Means for Solving the Problem) The present invention has been proposed for such a problem. At the time of anti-skid control, a hydraulic pump is opened and closed while opening and closing a hold valve and a decay valve arranged in a brake pipe. In an anti-skid brake device capable of operating and returning brake fluid in a brake cylinder to a master cylinder to eliminate a skid phenomenon, the hydraulic pump includes a housing, a cylinder member fitted and fixed in the housing, and a cylinder. A plunger slidably housed in a cylinder formed in the member, and a valve for sucking and discharging brake fluid by actuation of the plunger, and a width in a cross-sectional shape between the housing and the cylinder member. A hydraulic seal that is large with respect to the height is arranged, and the hydraulic seal has a discharge side oil passage. The hydraulic pressure acts in the width direction, and the hydraulic pressure discharged to the oil passage side with pulsation from the hydraulic pump during anti-skid control is transmitted to the hydraulic seal, and the pulsation is generated by deformation of the hydraulic seal. It is one that can be absorbed.

(Operation) According to the present invention, the hydraulic seal in the hydraulic pump has a larger cross-section than that of the conventional hydraulic pump, and the pulsation of the brake fluid generated in the hydraulic pump by the large hydraulic seal. And thereby alleviate the kickback phenomenon to the brake pedal.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings. FIG. 1 is a piping diagram of an anti-skid brake device according to an embodiment of the present invention, and FIG. 2 is an enlarged view of a hydraulic pump.

In the figure, reference numeral 1 denotes a brake pedal, and the brake pedal 1 is connected to a master cylinder 2. The master cylinder 2 is connected to a hold valve 4, a decay valve 5, and a reservoir 10.
And is connected to the hydraulic pump 20 via An oil passage between the hold valve 4 and the decay valve 5 is connected to a brake cylinder 6 of a wheel. Hold valve 4
Is operated by a signal from the control circuit 8, and when this valve operates, the master cylinder 2 and the brake cylinder 6
When the communication is cut off, the hydraulic pressure in the brake cylinder 6 is maintained. The decay valve 5 is operated by a signal from the control circuit 8. When the valve is operated and the oil passage between the brake cylinder 6 and the reservoir 10 is opened, the brake fluid in the brake cylinder 6 is discharged to the reservoir 10.

The reservoir 10 includes a cylinder 13, a plunger 22 housed in the cylinder 13, and a spring 12 for pressing the plunger 22 upward in the drawing. An oil passage 28 is connected to the reservoir 10, and the brake fluid discharged from the brake cylinder 6 flows through the oil passage 28 into the reservoir 10 and is stored therein.

In FIG. 2, the hydraulic pump 20 includes a housing 30, a cylinder member 23 fitted and fixed in the housing 30, and a plunger 22 slidably housed in a cylinder formed in the cylinder member 23. The plunger 22 and the silina member 23 have an oil chamber for supplying and discharging brake fluid.
31 are formed. An oil passage 29 communicating with the reservoir 10 and an oil passage 33 communicating with the master cylinder 2 are formed in the cylinder member 23. The oil passage 29 and the above-described oil chamber 31 are provided only from the oil passage 29 to the oil chamber 31 side. Ball valve that allows brake fluid to flow
Connected at 25. This ball valve 25 is a plunger 22
Are pressed rightward in the figure by a spring 27 interposed therebetween. The oil chamber 31 and the oil passage 33 are connected by a ball valve 24 that allows oil to flow only from the oil chamber 31 to the oil passage 33. The ball valve 24 is pressed toward the oil chamber 31 by a leaf spring 36. ing. The plunger 22 is in contact with a camshaft 21 driven by a signal from the control circuit 8 by a spring 26, and the rotation of the camshaft 21 causes the plunger 22 to move into the cylinder member 23.
It is configured to be able to reciprocate inside. Therefore, the control circuit 8
When the motor 9 is driven by the signal of the above, the camshaft 21 rotates and the plunger 22 reciprocates, the brake fluid flows into the oil chamber 31 through the ball valve 25, and then the brake fluid flowing into the 31 It is returned to the master cylinder 2 side via 24. A hydraulic seal 32 for sealing the brake fluid flowing through a gap between the cylinder member 23 and the housing 30 is disposed between the cylinder member 23 and the housing 30. The hydraulic seal 32 has a cross-sectional shape whose width is relatively large with respect to its height so as to absorb the pulsation of the brake hydraulic pressure. In experiments, it has been confirmed that when the ratio of the width to the height of the cross section of the hydraulic seal 32 is at least 2: 1 or more, an effective volume change capable of absorbing the pulsation of the brake hydraulic pressure is obtained. Therefore, the hydraulic seal 32 of the present invention has a function of absorbing the pulsation of the brake fluid generated by the hydraulic pump in addition to the function of sealing the brake fluid.

The control circuit 8 has a function of calculating the wheel speed, the slip ratio, the speed, and the like based on the input from the sensor 7 as is well known, and based on the calculation result, the hold valve 4,
The decay valve 5 and the hydraulic pump 20 are controlled. When the control circuit 8 detects the skid of the wheel based on the signal of the wheel sensor 7, the control circuit 8 controls the hold valve 4, the decay valve 5, and the motor 8 to hold the brake fluid pressure, and then the decay valve 5 is opened. To return the brake fluid from the brake cylinder to the master cylinder to control the skid condition of the wheels.

Next, the operation of the anti-skid brake device will be described.

When the brake pedal is depressed to apply a brake to the vehicle, hydraulic pressure is generated in the master cylinder. This hydraulic pressure is supplied to the brake cylinder via the hold valve 4 to apply a braking force to the wheels. The state of the wheels is detected by a sensor 7 and applied to a control circuit 8 as an input. The control circuit 8 determines the wheel speed, the slip ratio,
It has a function of calculating deceleration and the like, evaluates the skid state of the wheels based on the results of these calculations, and controls the hold valve 4, the decay valve 5, and the motor 8. Now, when the brake holding signal is output from the control circuit 8, the hold valve 4 is operated, the oil passage between the master cylinder and the brake cylinder is cut off, and the brake fluid pressure of the brake cylinder is held. When a brake release signal is output from the control circuit 8, the hold valve 4 is closed and the decay valve 5 is opened while the oil passage between the master cylinder and the brake cylinder is shut off, and the oil passage between the brake cylinder and the reservoir is connected to connect the brake cylinder. Brake fluid is drained to the reservoir. Then, the brake fluid discharged to the reservoir is pressurized by the hydraulic pump 20 which operates at the same time as the hydraulic pressure control is started, and is returned to the hydraulic fluid supply line of the master cylinder 2. Specifically, when the motor 9 is driven by the signal of the control circuit 8 to rotate the camshaft 21 and the plunger 22 moves, for example, to the left in the drawing, the brake fluid is supplied to the oil chamber via the ball valve 25. When the plunger 22 moves rightward in the drawing, the brake fluid that has flowed into the oil chamber 31 is returned to the master cylinder 2 via the ball valve 24. As a result, the brake fluid in the brake cylinder 6 is returned to the master cylinder, and the brake is released. By the way, at this time, when the brake fluid is pressurized by the plunger 22 of the hydraulic pump 20, pulsation occurs in the brake fluid pressure.
This pulsation is not preferable because it causes a large kickback, but in the present invention, the pulsation is caused by the cylinder member.
It reaches the hydraulic seal 32 through the gap between the housing 23 and the housing, and deforms the hydraulic seal 32, thereby absorbing the pulsation of the brake hydraulic pressure. Therefore, in the present invention, the kickback phenomenon due to pulsation as in the conventional hydraulic pump can be reduced.

Although the present embodiment has been described with reference to one brake system, it is needless to say that the present invention can be applied to a brake system having two or more brake systems.

(Effects of the Invention) According to the present invention, the hydraulic seal 32 of the hydraulic pump is shaped to have a large volume change, so that the hydraulic seal can absorb the pulsation of the brake fluid generated by the hydraulic pump. As a result, the kickback phenomenon to the brake pedal can be reduced. Further, a device for reducing the fluctuating pressure for eliminating kickback, which is conventionally disposed in the brake pipe, becomes unnecessary.

[Brief description of the drawings]

1 is a piping diagram of an anti-skid brake device according to an embodiment of the present invention, FIG. 2 is an enlarged view of a hydraulic pump, and FIG. 3 is a piping diagram of a conventional anti-skid brake device. FIG. 4 is an enlarged view of a conventional hydraulic pump. Description of main parts in the drawing 1 ... Brake pedal 2 ... Master cylinder 4 ... Hold valve 5 ... Decay valve 6 ... Brake cylinder 7 ... Sensor 8 ... Control circuit 9 ... Motor 10 ... Reservoir 20 ... ... Hydraulic pump 21 ... Camshaft 22 ... Plunger 23 ... Cylinder member 32 ... Hydraulic seal

Claims (1)

(57) [Scope of request for utility model registration] 1. During anti-skid control, a hydraulic pump 20 is operated while opening and closing a hold valve 4 and a decay valve 5 disposed in a brake pipe to return a brake fluid in a brake cylinder 6 to a master cylinder 2 to skid. In the anti-skid brake device that can eliminate the phenomenon, the hydraulic pump 20 includes a housing 30, a cylinder member 23 fitted and fixed in the housing 30, and a slidable cylinder in the cylinder formed in the cylinder member 23. A plunger 22 housed in the housing, and valves 24 and 25 for sucking and discharging the brake fluid by the operation of the plunger. A large hydraulic seal 32 is arranged, and the hydraulic pressure of the oil passage 33 on the discharge side acts on the hydraulic seal 32 in the width direction. The hydraulic pressure discharged to the oil passage 33 with pulsation from the hydraulic pump 20 at the time of chip skid control is transmitted to the hydraulic seal 32, and the hydraulic pressure
An anti-skid brake device characterized in that pulsation can be absorbed by the deformation of 32.