JPH05229412A - Hydraulic controller for antiskid - Google Patents

Abstract

PURPOSE:To remove generate small kick back phenomena and remove the sense of unease by remarkable kick back while making it recognize that an antiskid device is operating normally by making it in such mechanism as to accumulate one part of the brake liquid discharged from a hydraulic pump in an accumulator. CONSTITUTION:When the discharge pressure of a hydraulic pump 10 is smaller than the force of a relief spring 21 after an antiskid device is started, the discharged brake liquid passes a check valve 2. And it returns to a master cylinder 14, passing an outlet port 16, an orifice 35, and an inlet port 15. Since the discharge pressure is throttled by the orifice 35, the hydraulic pressure fluctuation of the master cylinder 14 is small, and kick back also is small. When the discharge pressure becomes higher than the force of the relief spring 21, an orifice piston 20 and the relief piston 23 shifts up, and and a passage 18 is opened, and one part of the discharged brake liquid flows in an accumulator 12. Accordingly, only the one part of brake liquid returns to the master cylinder 14, and kick back phenomena is lightened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anti-skid device (hereinafter referred to as an ABS device), in which the hydraulic fluid returned to the hydraulic fluid supply line by a hydraulic pump during anti-skid control is a hydraulic pressure generating chamber of a master cylinder. The present invention relates to an ABS hydraulic pressure control device that can alleviate the so-called kickback phenomenon that occurs when the piston of the master cylinder is pushed back and the brake pedal is pushed back.

[0002]

2. Description of the Related Art Conventionally, various ABS devices have been developed which are capable of exerting a more effective and safe braking force on an automobile on any road surface. In these ABS devices, the skid state of the wheels is evaluated by a control unit (electronic control device), and based on this evaluation, the brake fluid pressure supplied to the brake device for the wheels is decreased, increased, or held constant, The braking force that acts on the wheels is controlled.

As an example of such an ABS device, an actual Kaihei 1
-65746. This device has a hydraulic control valve between the master cylinder and the wheel cylinder of the wheel brake device, which receives a command from the control unit that evaluates the skid state of the wheel and controls the brake hydraulic pressure of the wheel cylinder. At the same time, when releasing the brake fluid pressure, a reservoir for storing the brake fluid discharged from the wheel cylinder via the fluid pressure control valve is provided, and the brake fluid discharged to the reservoir is pressurized by a hydraulic pump, The master cylinder and the hydraulic pressure control valve are connected to each other via a pressure liquid supply conduit (so-called liquid recirculation type ABS device).

However, in this ABS system of liquid recirculation type, the brake fluid discharged to the reservoir is pressurized by a hydraulic pump operating at the same time when the hydraulic control is started,
Since the pressure is directly returned to the pressure fluid supply line of the master cylinder, the fluid pressure fluctuates greatly, causing the hydraulic pressure discharged from the pump to push back the piston in the master cylinder, a phenomenon known as kickback. There was a problem such as giving anxiety and discomfort.

Therefore, in order to solve the above problem, an ABS device which does not generate a kickback phenomenon to the brake pedal at the time of anti-skid control has been developed (so-called variable volume ABS device, Japanese Patent Publication No. 61-16656).
Publication). This device is arranged between a master cylinder and a wheel cylinder of a wheel brake device, and receives a command from a control unit that evaluates a skid state of a wheel, and a hydraulic control valve that controls a brake hydraulic pressure of the wheel cylinder. And a reservoir for storing the brake fluid discharged from the wheel cylinder via the fluid pressure control valve when the brake fluid pressure is reduced by the control of the fluid pressure control valve,
An accumulator provided in a pressure fluid supply line connecting the master cylinder and the fluid pressure control valve, and a hydraulic pump for pressurizing the brake fluid stored in the reservoir to accumulate the pressure in the accumulator are provided. Therefore, all the brake fluid discharged from the hydraulic pump during the anti-skid control can be accumulated in the accumulator. Therefore, in this device, the pulsation of the brake fluid by the hydraulic pump can be completely absorbed by the accumulator, and kickback does not occur at all.

However, since this device has a mechanism for accumulator to store all the brake fluid pumped up from the reservoir by the hydraulic pump, the kickback phenomenon can be surely prevented, but at the time of anti-skid control. A large volume accumulator capable of accommodating all the liquid discharged from the hydraulic pump and a high hydraulic pressure accumulator for re-pressurizing and a switching valve for separating the master cylinder and the wheel cylinder are indispensable, which causes the device to become large. Inconvenience occurs. Furthermore, the fact that kickback does not occur at all makes it impossible for the driver to determine whether the ABS device is operating normally, and
It has also come to be pointed out that the driver feels anxiety rather than unfavorable.

[0007]

From the above technical background, recently, an ABS device in which a kickback phenomenon appropriately occurs is being developed, and the present invention is based on the fact that the ABS device operates normally. While making the driver aware that
It is intended to propose an ABS device in which the kickback phenomenon is not so remarkable.

[0008]

Therefore, the technical solution of the present invention evaluates the skid state of the wheel by the electronic control unit, and reduces the brake fluid pressure supplied to the brake unit of the wheel based on this evaluation. In the anti-skid device capable of controlling the braking force acting on the wheel by raising, or holding it at a constant level, the anti-skid device includes a reservoir 9 for accumulating brake fluid discharged from the brake cylinder, and an accumulator 12. , A hydraulic pump 10 for pumping the brake fluid from the reservoir 9 and the accumulator 12, and a discharge pressure from the hydraulic pump 10 is returned to a master cylinder through a throttle and a discharge pressure from the hydraulic pump 10 has a predetermined value. When the above is reached, the brake fluid from the hydraulic pump 10 is transferred to the accumulator 1
It is characterized in that it has a switching valve 1 capable of supplying to No. 2.

[0009]

Operation: Anti-skid control is started and hydraulic pump 1
When the discharge pressure from 0 is smaller than the spring force of the relief spring 21, the discharge brake fluid from the hydraulic pump 10 passes through the check valve 21 → the outlet passage 16 → the passage 34 → the orifice 35 → the passage 33 → the inlet passage 15. And returns to the master cylinder 14. At this time, since the discharge pressure from the hydraulic pump 10 is throttled by the orifice 35, the hydraulic pressure fluctuation in the master cylinder is small and the kickback is small.

When the discharge pressure from the hydraulic pump 10 becomes higher than the spring force of the relief spring 21, the orifice piston 20 and the relief piston 24 resist the urging force of the relief spring 21 by the discharge brake fluid from the hydraulic pump 10. And move upward in the figure. Along with this, the valve rod assembly 27 is also moved upward by the stopper 28, the passage 18 closed by the valve rod 36 is opened, and a part of the liquid discharged from the hydraulic pump flows into the accumulator 12.

Thus, when the brake fluid discharged from the hydraulic pump 10 has a hydraulic pressure equal to or higher than a predetermined value, only a part of the brake fluid flows back to the master cylinder, so that the phenomenon of kickback can be alleviated. Excess brake fluid that cannot accumulate pressure in the accumulator 12 is sucked by the hydraulic pump 10 via the check valve 11 and circulates in the flow path.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a hydraulic piping diagram of an anti-skid control device according to an embodiment of the present invention, and FIG. 2 is a sectional view of a switching valve according to an embodiment of the present invention. Each valve, hydraulic pump, etc. provided in the hydraulic circuit are controlled by a known electronic control unit (not shown). Further, since the front wheel and rear wheel piping systems in the figure have the same configuration, only the pipe on the right side (here, the rear wheel) in FIG. 1 will be described below.

In FIG. 1, 13 is a brake pedal, and 14 is
Is a master cylinder, and the master cylinder 14 has an inlet passage 15, an outlet passage 16, passages 17, 18 as will be described later.
Is connected to the inlet passage 15 of the switching valve 1. On the other hand, the outlet passage 16 of the switching valve 1 is connected to the brake cylinders 4 and 6 via the hold valves 3 and 5. The brake cylinders 4 and 6 are connected to a reservoir 9 via decay valves 7 and 8.

The suction port of the hydraulic pump 10 is connected to the conduit between the decay valves 7 and 8 and the reservoir 9, and the discharge port of the hydraulic pump 10 is connected to the outlet passage 16 via the check valve 2. It is in communication with and is connected to a passage 17 formed in the switching valve 1. The passage 18 of the switching valve 1 is connected to the accumulator 18.

The hold valves 3 and 5 are operated by a signal from an electronic control unit (not shown). When the valves are closed, the communication between the switching valve 1 and the brake cylinders 4 and 6 is cut off. Further, the decay valves 7 and 8 are operated by a signal from an electronic control unit (not shown),
When this valve is opened, the oil passage between the brake cylinders 4, 6 and the reservoir 9 is opened and the brake fluid in the brake cylinders 4, 6 is discharged to the reservoir 9. The reservoir 9 is for storing the brake fluid discharged from the brake cylinders 4 and 6.

The hydraulic pump 10 is for pumping the brake fluid from the reservoir 9 at the time of anti-skid control, and is operated by a signal from the electronic control unit to pump the brake fluid stored in the reservoir 9 as will be described later. ,
Return to the master cylinder 14 via the check valve 2 and the switching valve 1, or the passage 17 of the switching valve 1,
The pressure is accumulated in the accumulator 12 via 18. The accumulator 12 is connected to the suction port of the hydraulic pump 10 via a check valve 11.

The structure of the switching valve 1 will be described with reference to FIG. The switching valve 1 has the inlet passage 15, the outlet passage 16, the passage 17, and the passage 18 as described above, and the piston accommodating chamber 19 communicating with each passage is formed in the valve body. In the piston accommodating chamber 19, as shown in FIG.
And the relief piston 24 are arranged in contact with each other, and the orifice piston 20 and the relief piston 24 are normally urged toward the valve seat 30 by the relief spring 21.

The orifice piston 20 corresponds to the inlet passage 1
5, the relief piston 24 has a passage 34 which communicates with the outlet passage 16, and the orifice valve 2 is provided between the passages 33, 34.
2 is arranged so as to be sandwiched between the pistons 20 and 24. The orifice valve 22 has a passage 33 of the orifice valve 22 due to a relatively weak spring 23.
Is biased toward, which causes passages 33 and 34
An orifice 35 is formed between and.

Further, the relief piston 24 is provided with passages 38 and 39 for communicating the passage 17 and the passage 18 formed in the switching valve 1, and the valve rod assembly 27 is provided in the passages 38 and 39. Are arranged. The valve rod assembly 27 is a valve rod 3
6, a stopper 37 fixed to the valve rod 36, and a spring 26. Both ends of the valve rod 36 are slidably supported by guides 25, 25, and are normally urged by a spring 26 to engage with a valve seat 30 to close the passage 18.

Since this embodiment is constructed as described above, the following operation is performed during normal braking and antiskid control. [When the normal brake is operating] In FIG. 1, when the normal brake is operating, the switching valve 1 is in the state shown in FIG.
Therefore, the inlet passage 15 formed in the switching valve 1 is the passage 3
3, orifice 35 of orifice valve 22, passage 34
Through the outlet passage 16.

Therefore, in this state, when the brake pedal 13 is operated to generate the hydraulic pressure in the master cylinder 14, the hydraulic pressure from the master cylinder 14 causes the inlet passage 15 →
It acts on the orifice valve 22 via the passage 33, and the orifice valve 22 moves downward in the figure against the spring 23. As a result, the brake fluid does not receive a large resistance and the orifice valve 22 → passage 34 → exit passage 1
It is supplied to the brake cylinders 4 and 6 through 6 to operate the brake. As described above, normally, when the brake pedal is depressed, the brake fluid in the master cylinder is supplied to the brake cylinder through the oil passage to brake the wheels.

When the brake pedal is returned, the brake fluid in the brake cylinders 4 and 6 is discharged from the outlet passage 16 → passage 34 →
The brake is released by being returned to the master cylinder 19 through the orifice 35, the passage 33, and the inlet passage 15. At this time, the brake fluid from the brake cylinders 4 and 6 is returned to the master cylinder while being throttled by the orifice 35 of the orifice valve 22 which has returned to the state of FIG.

[During Anti-Skid Control] When there is a risk of wheel locking due to excessive braking force, a brake holding signal is output from an electronic control unit (not shown), the hold valves 3 and 5 are closed, and the master cylinder and the brake cylinder are closed. The oil passages to 4 and 6 are cut off, and the brake fluid pressure in the brake cylinders 4 and 6 is maintained in that state. When a brake loosening signal is output from the electronic control unit, the hold valves 3 and 5 are closed and the decay valves 7 and 8 are closed.
Is opened to connect the oil passages between the brake cylinders 4 and 6 and the reservoir 9. As a result, the brake fluid in the brake cylinders 4 and 6 is discharged to the reservoir 9 and the brake is released.

The brake fluid discharged to the reservoir 9 is pumped up by the hydraulic pump 10 which operates at the same time when the anti-skid control is started and is returned to the master cylinder or accumulated in the accumulator 12. That is, when the discharge hydraulic pressure from the hydraulic pump is small and cannot overcome the spring force of the relief spring 21 and the hydraulic pressure of the master cylinder, the orifice piston 20 and the relief piston 24 maintain the state of FIG. 36 closes the passage 18 to the accumulator.

As a result, the brake fluid discharged from the hydraulic pump 10 is checked valve 2 → outlet passage 16 → passage 34 →
It flows back to the master cylinder 14 through the orifice 35, the passage 33, and the inlet passage 15. In this way, the locking tendency of the wheels is released, and the vehicle is decelerated or stopped in a stable state. Further, at this time, the brake fluid discharged from the hydraulic pump 10 flows back to the master cylinder while being throttled by the orifice 35, so that the hydraulic pressure fluctuation is small and the kickback is small.

Further, when the discharge pressure from the hydraulic pump 10 becomes higher than the spring force of the relief spring 21 and the master cylinder hydraulic pressure, this hydraulic pressure pushes the relief piston 24 upward in the drawing, and the orifice piston 20 is relieved. It is pushed upward together with the orifice piston 20 in the figure against the biasing force of the spring 21. Along with this, the valve rod assembly 27 and the stopper 28
Is moved upward, the passage 18 closed by the valve rod 36 is opened, and a part of the discharge liquid of the hydraulic pump flows into the accumulator 12.

Even at this time, a part of the liquid discharged from the hydraulic pump is returned to the master cylinder through the orifice 35. As described above, when the hydraulic pressure of the brake fluid discharged from the hydraulic pump 10 becomes equal to or higher than a predetermined value, most of the brake fluid is provided in the passage 17 of the switching valve 17 → the passage 3 of the relief piston.
8, 39 → The pressure is accumulated in the accumulator through the passage 18 and only a part of the brake fluid is returned to the master cylinder. Therefore, the kickback phenomenon is transmitted to the driver in a relaxed state.

Excess brake fluid that cannot be accumulated in the accumulator 12 is sucked by the hydraulic pump 10 via the check valve 11 and circulates in the flow passage. When it is necessary to pressurize the brake during the anti-skid control, the brake fluid discharged from the hydraulic pump is supplied to the brake cylinder via the check valve 2 → the hold valves 3 and 5 to perform the brake operation. Since the discharge pressure at this time is smaller than the spring force of the relief spring, the passage 18 remains blocked, and the brake fluid does not flow to the accumulator side.

The anti-skid control of the wheel is executed by repeating the above operation. The hydraulic pressure control of each brake cylinder 4 and 6 is independently performed according to the state of each wheel. As described above, according to the present invention, when the discharge pressure from the hydraulic pump is equal to or higher than a predetermined value during the anti-skid control, most of the brake hydraulic pressure discharged from the hydraulic pump is accumulated in the accumulator. The back can be relaxed.

[0030]

As described in detail above, according to the present invention, since the mechanism for accumulating a part of the liquid discharged from the hydraulic pump in the accumulator having a small capacity, the kickback phenomenon is alleviated. Occurs when the driver is
The driver does not feel anxiety due to kickback while notifying that the BS device is operating normally.
Further, since it is not necessary to store the entire discharge liquid from the hydraulic pump in the accumulator during the anti-skid control, a large-capacity high hydraulic pressure type accumulator is not required, and the size of the device can be prevented from increasing. It has excellent effects such as.

[Brief description of drawings]

FIG. 1 is a piping diagram of an ABS hydraulic pressure control device as an embodiment according to the present invention.

FIG. 2 is a cross-sectional view of a switching valve according to the present invention.

[Explanation of symbols]

 1 Switching valve 2 Check valve 3, 5 Hold valve 4, 6 Brake cylinder 7, 8 Decay valve 9 Reservoir 10 Hydraulic pump 12 Accumulator

Claims (1)

[Claims] 1. A wheel skid state is evaluated by an electronic control device, and based on this evaluation, a brake fluid pressure supplied to a wheel brake device is lowered, raised, or held constant to act on the wheel. In the anti-skid device capable of controlling the braking force to be applied, the anti-skid device includes a reservoir 9 for storing the brake fluid discharged from the brake cylinder, an accumulator 12, and a hydraulic pressure for pumping the brake fluid from the reservoir 9 and the accumulator 12. The discharge pressure from the pump 10 and the hydraulic pump 10 is returned to the master cylinder through a throttle, and when the discharge pressure from the hydraulic pump 10 becomes a predetermined value or more, the brake fluid from the hydraulic pump 10 is collected by the accumulator. Anti-ski valve having switching valve 1 capable of supplying Liquid pressure control device for head.