JPS63297159A - Actuator for wheel braking device - Google Patents

Abstract

PURPOSE:To improve the fitting property to a vehicle and reduce the cost by connecting the first and second pipelines to a master cylinder and a wheel cylinder respectively to complete the fitting to the vehicle and using a liquid pressure pump as a liquid pressure source at the time of lock prevention and slip prevention. CONSTITUTION:The fitting of an actuator A to a vehicle is completed when the first pipeline 21 is connected to a master cylinder 11 and the second pipeline 22 is connected to a wheel cylinder 12. At the time of antiskid control, a transfer valve 28 connects the pipeline 21 to the discharge path 27b of a liquid pressure pump 27 and connects a passage 29 to a reservoir 23, and the function that the liquid pressure in the pipeline 22 is reduced and the braking force is decreased, the function that the liquid pressure is held and the braking force is held, and the function that the liquid pressure is fed and the braking force is increased are obtained in response to the locking state of a wheel 13 at the time of braking, and the lock of the wheel 13 is prevented. The transfer valve 28 connects the pipeline 21 to the reservoir 23 and connects the discharge path 27b of the pump 27 to the passage 29 at the time of traction control, the wheel 13 is braked in response to the slip at the time of start and acceleration, and the slip is prevented.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a wheel braking device for a vehicle, and particularly relates to an anti-skid control function (a function that prevents wheels from locking during vehicle braking) and a traction control function (a function that prevents wheels from locking when braking a vehicle). The present invention relates to an actuator for a wheel braking device, which has a function of preventing wheel slippage when starting or accelerating a vehicle.

[Conventional technology]

This type of actuator has conventionally been used, for example, in
This is proposed in Publication No. 38243.

However, the actuator proposed in the same publication is combined with a hydraulic booster equipped with a hydraulic pump, an Achiemulator, etc., and moreover, pressure fluid for traction control is supplied from the Achiemulator of the hydraulic booster. It is designed to be introduced through a bypass pipe.

[Problem that the invention seeks to solve]

Therefore, in the conventional actuator described above,
■When installing on a vehicle, it is necessary to connect piping to the hydraulic booster and wheel cylinder as well as to the accumulator of the hydraulic booster (for this, a new piping connection must be installed on the accumulator).
It is difficult to attach to the vehicle. (2) If the booster is not a hydraulic booster but, for example, a vacuum booster, it is necessary to separately provide a hydraulic pump or the like just to obtain pressure fluid for traction control. (2) In addition to (2) and (2) above, the wheel braking device is expensive. There are other problems.

[Means for solving problems]

The present invention has been made to solve the above-mentioned problems, and the above-described actuator is connected to a first pipe line connected to a brake master cylinder, a second pipe line connected to a brake wheel cylinder, and a required amount of hydraulic fluid. accommodating reservoir,
A supply switching valve that controls opening and closing of communication between the first pipe line and the second pipe line, a discharge switching valve that controls opening and closing of communication between the second pipe line and the reservoir, and a connection between the discharge switching valve and the reservoir. a hydraulic pump having a suction passage connected to the passage between the reservoir and the relief valve; a discharge passage of the hydraulic pump connecting the discharge switching valve and the relief valve; The present invention is characterized in that it is configured to include an intake/discharge switching valve that is connected to a passage or the first pipe line and connects the reservoir to the first pipe line or a passage that connects the discharge switching valve and the relief valve. .

[Action of the invention]

The actuator according to the present invention can be installed on a vehicle by connecting the first conduit to the brake master cylinder and the second conduit to the brake wheel cylinder. Time,
(during anti-skid control, traction control) The following operations can be obtained.

(When wheels are not braked) At this time, the brake master cylinder is in a non-operating state and no hydraulic pressure is generated, and the supply switching valve communicates the first pipe line with the second pipe line, so the brake No hydraulic pressure is applied to the wheel cylinder and the wheels are not braked.

(During wheel braking) - During normal braking At this time, the supply switching valve connects the first pipe and the second pipe, the discharge switching valve cuts off communication between the second pipe and the reservoir, and the intake/discharge switching valve Since the first pipe line is connected to the discharge path of the hydraulic pump and the passage connecting the discharge switching valve and the relief valve is connected to the reservoir, the hydraulic pressure in the brake master cylinder is applied to the brake wheel cylinder and the wheels are braked. Ru.

・'Anti-skid control At this time, the suction/discharge switching valve connects the first pipe to the discharge path of the hydraulic pump, and the passage connecting the discharge switching valve and the relief valve to the reservoir. Depending on the locked state of the wheels, (8) the supply switching valve cuts off communication between the first pipe line and the second pipe line, and the discharge switching valve connects the second pipe line and the reservoir, so that the second pipe line Pressure fluid in the passage flows to the reservoir through the discharge switching valve and the suction/discharge switching valve, and the fluid pressure in the second pipe decreases, reducing the wheel braking force. (b) The supply switching valve is connected to the first pipe By communicating the fluid pressure in the first pipeline (the discharge pressure of the hydraulic pump ) is supplied to increase the wheel braking force, thereby optimally preventing the wheels from locking.

・During traction control - At this time, the suction/discharge switching valve connects the first pipe line to the reservoir and the discharge line of the hydraulic pump to the passage connecting the discharge/switching valve and the relief valve, allowing the vehicle to start and accelerate. Depending on the slippage of the wheels at the time, the supply switching valve cuts off communication between the first pipe line and the second pipe line, and the discharge switching valve opens communication between the second pipe line and the passage connecting the discharge switching valve and the relief valve. Well, second
The wheels are braked so that the pressure fluid discharged from the hydraulic pump (pressurized in advance by the relief valve) is supplied to the pipeline through the suction/discharge switching valve and the discharge switching valve, and the vehicle starts and accelerates. Wheel slippage at times is optimally prevented.

〔Effect of the invention〕

The actuator according to the present invention can be installed on a vehicle by connecting the first conduit to the brake master cylinder and the second conduit to the brake wheel cylinder. There is no need to change anything at all, and it is easy to install on the vehicle. (2) Since the hydraulic pump functions as a hydraulic pressure source during anti-skid control and also as a hydraulic pressure source during traction control, the actuator has a compact configuration and can be made smaller and lighter. (2) In addition to the above-mentioned effects (2) and (2), the wheel braking device including the actuator becomes inexpensive. The following effects can be expected.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

1 to 3 show a first embodiment of the present invention, and in the vehicle hydraulic wheel braking device shown in FIG. 1, a brake master cylinder (hereinafter simply referred to as A mask cylinder (referred to as a mask cylinder) 11 is connected to a brake wheel cylinder (hereinafter simply referred to as a wheel cylinder) 12 through a hydraulic pressure line, and the hydraulic pressure applied to the wheel cylinder 12 is controlled by an actuator A according to the present invention. (some parts are omitted).

The actuator A includes a first pipe line 21 connected to the mask cylinder 11, a second pipe line 22 connected to the wheel cylinder 12, and a reservoir 2 that can accommodate a required amount of hydraulic fluid.
3 and a supply switching valve 24. Discharge switching valve 25
．． Relief valve 26° hydraulic pump 27. It is equipped with a suction/discharge switching valve 28 and a control valve 30.

The supply switching valve 24 is a two-bottom, two-position electromagnetic on-off valve,
During demagnetization, the pipe line 21 connected to the mask cylinder 11 and the pipe line 22 connected to the wheel cylinder 12 are communicated, and during excitation, the communication between the pipe line 21 and the pipe line 22 is cut off. The discharge switching valve 25 is a two-bottom, two-position electromagnetic on-off valve, and when demagnetizing, the pipe line 22 and the passage 29 (relief valve 26
or connected to the reservoir 23 via the suction/discharge switching valve 28), and at the time of excitation, the conduit 22 and the passage 29 are communicated. Therefore, both switching valves 24.25
The switching operation (demagnetization, excitation) is controlled by an electric control device (not shown).
When there is no need to brake the wheels 13, they are both demagnetized as shown in the figure, and during anti-skid control, demagnetization and excitation are repeated depending on the locked state of the wheels 13 (
Furthermore, during traction control, both switching valves 2 are switched depending on the slip state of the wheels 13.
4.25 are both excited.

The reservoir 23 includes a piston 23a and a spring 23b, and is capable of accommodating the hydraulic fluid to be returned and supplying the hydraulic fluid contained therein to the suction path 27a of the hydraulic pump 27. The relief valve 26 is interposed in a passage connecting the discharge switching valve 25 and the reservoir 23, and as shown in the figure, the relief valve 26 is connected to the discharge switching valve 25 and the reservoir 23.
The passage 29 between them is connected to the discharge path 27b of the hydraulic pump 27, so that when the hydraulic pump 27 is driven, the pump discharge pressure becomes the set pressure. The hydraulic pump 27 is constantly driven by an electric motor (not shown) during vehicle operation, and is configured to suck in hydraulic fluid from the suction passage 27a and discharge it to the discharge passage 27b.

The suction/discharge switching valve 28 is a switching valve that operates using the hydraulic pressure in the pipe line 21 as a pilot pressure, and, as shown in FIG. 2, includes a spool 28a and a spring 28b. This suction/discharge switching valve 28 connects the pipe line 21 to the reservoir 23 via the control valve 30 as shown in the figure when the hydraulic pressure in the pipe line 21 is approximately zero, and also connects the pipe line 21 to the reservoir 23 via the control valve 30.
The discharge passage 27b of the hydraulic pump 27 is connected to the passage 29 between the relief valve 26 and the discharge switching valve 25, and when the hydraulic pressure in the pipe line 21 is higher than the set value, the discharge passage 27b of the hydraulic pump 27 is connected to the passage 29 between the relief valve 26 and the discharge switching valve 25.
is connected to the first conduit 21 via the reservoir 2
3 to the passage 29.

As shown in FIG. 3, the control valve 30 is a differential pressure generating valve 3.
1 and a check valve 32, the differential pressure generating valve 31 does not open until the hydraulic pressure in the pipe line 21 reaches a set value, and the suction/discharge switching valve 28 operates during braking, and the pressure in the pipe line 21 is closed. 2
1 is connected to the discharge line 27b of the hydraulic pump 27 (a function to prevent hydraulic fluid from flowing from the pipe line 21 to the reservoir 23 during braking), and the check valve 32 is connected to the discharge line 27b of the hydraulic pump 27. It has a function of allowing flow to 21.

The actuator A of this embodiment configured as described above is
Installation to the vehicle is completed by connecting the first conduit 21 to the mask cylinder 11 and the second conduit 22 to the wheel cylinder 12, and when the wheels are not braked and when the wheels are braked (during normal braking).

During anti-skid control and traction control), the following operations are available.

(When wheels are not braked) At this time, the mask cylinder 11 is in a non-operating state and no hydraulic pressure is generated, and the supply switching valve 24 communicates the first pipe line 21 and the second pipe line 22. Therefore, no hydraulic pressure is applied to the wheel cylinder 12 and the wheel 13 is not braked. Note that at this time, the hydraulic fluid discharged from the hydraulic pump 27 flows through the suction/discharge switching valve 28 and the relief valve 26.
circulating through.

(During wheel braking) - During normal braking At this time, the supply switching valve 24 connects the first pipe line 21 and the second pipe line 22, and the discharge switching valve 25 blocks communication between the second pipe line 22 and the passage 29. , the suction/discharge switching valve 28 operates to connect the first pipe line 21 to the discharge line 27b of the hydraulic pump 27 and the passage 29 to the reservoir 23, so that the hydraulic pressure in the mask cylinder 11 is applied to the wheel cylinder 12. Then, the wheels 13 are braked.

- During anti-skid control At this time, the suction/discharge switching valve 28 connects the first pipe line 21 to the discharge passage 27b of the hydraulic pump 27 and the passage 29 to the reservoir 23, and locks the wheels 13 when the vehicle is braked. Depending on the state, (the Al supply switching valve 24 cuts off communication between the first pipe line 21 and the second pipe line 22, and the discharge switching valve 2
5 connects the second pipe line 22 and the reservoir 23, so that the pressure liquid in the second pipe line 22 is transferred to the discharge switching valve 25 and the suction/reservoir 23.
The liquid flows into the reservoir 23 through the discharge switching valve 28, and the hydraulic pressure in the second pipe line 22 decreases, reducing the wheel braking force.
b) The supply switching valve 24 cuts off communication between the first pipe line 21 and the second pipe line 22, and the discharge switching valve 25 cuts off communication between the second pipe line 22 and the reservoir 23, so that the second pipe line The effect of maintaining the hydraulic pressure in 22 and maintaining the wheel braking force, (C
) The supply switching valve 24 connects the first pipeline 21 and the second pipeline 22, and the discharge switching valve 25 connects the second pipeline 22 and the reservoir 2.
3, the first
The hydraulic pressure in the pipe 21 (the discharge pressure of the hydraulic pump 27) is supplied to increase the wheel braking force, thereby optimally preventing the wheels 13 from locking.

- During traction control At this time, as shown in the figure, the suction/discharge switching valve 28 connects the first pipe line 21 to the reservoir 23 and the discharge line 27b of the hydraulic pump 27 to the passage 29. Depending on the slip of the wheel 13 in the supply switching valve 24
disconnects communication between the first conduit 21 and the second conduit 22, and the discharge switching valve 25 connects the second conduit 22 and the passage 29.
The wheels 13 are braked so that the pressure fluid (pressurized in advance by the relief valve 26) discharged from the hydraulic pump 27 is supplied to the pipe line 22 through the suction/discharge switching valve 28 and the discharge switching valve 25. This prevents the wheels 13 from slipping optimally when the vehicle starts and accelerates.

As is clear from the above description, the actuator A of this embodiment has the following features: (1) When installed on a vehicle, the first conduit 21 is connected to the mask cylinder 11 and the second conduit 22 is connected to the wheel cylinder 12. Since the installation to the vehicle is completed by this, there is no need to change the configuration of the existing brake system at all, and the installation to the vehicle is extremely easy.

(2) Since the hydraulic pump 27 functions as a hydraulic pressure source during anti-skid control and also functions as a hydraulic pressure source during traction control, the structure of the actuator A is compact and can be made smaller and lighter. ■The above ■.

Along with the effect (2), the wheel braking device including the actuator A becomes inexpensive. Effects such as these can be expected.

FIG. 4 shows a second embodiment of the present invention, in which a supply/discharge switching valve 24A is employed in place of the supply switching valve 24 and discharge switching valve 25 of the first embodiment. There is. The supply/discharge switching valve 24A is a three-point/two-position electromagnetic switching valve, and connects the pipe line 22 to the pipe line 21 during demagnetization, and connects the pipe line 22 to the passage 29 during excitation. Therefore, the switching operation (demagnetization, excitation) of the supply/exhaust switching valve 24A is controlled by an electric control device (not shown).
It is designed to be switched during anti-skid control and traction control.

In addition, in the first and second embodiments described above, the control valve 30
However, if the spring force of the suction/discharge switching valve 28 is reduced to increase the operational response of the suction/discharge switching valve 28, the invention can be carried out without using the control valve 30. Can be done.

FIG. 5 shows a third embodiment of the present invention, in which the suction/discharge switching valve 28 of the second embodiment is
In place of the control valve 30, a suction/discharge switching valve 28A is employed. The intake/discharge switching valve 28A is a 4-point/2-position electromagnetic switching valve, and is energized during normal braking and anti-skid control.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing a first embodiment of the present invention, FIG. 2 is an enlarged sectional view of the suction/discharge switching valve portion shown in FIG. 1,
Figure 3 is an enlarged sectional view of the control valve shown in Figure 1;
The figure is a schematic diagram showing a second embodiment of the present invention, and FIG. 5 is a schematic diagram showing a third embodiment of the invention. Explanation of symbols 11...Mask cylinder, 12...Wheel cylinder, 13...Wheel, 21...First conduit, 22...
2nd pipe line, 23... Reservoir, 24... Supply switching valve, 25... Discharge switching valve, 24A... Supply/discharge switching valve, 2
6... Relief valve, 27... Hydraulic pump, 27a.
...Suction path, 27b...Discharge path, 28.28A...
Suction/discharge switching valve, 29... Passage connecting the discharge switching valve and relief valve, A... Actuator. Applicant Aisin Seiki Co., Ltd. (1 other person) Agent Patent attorney Teru Hase - (1 other person) Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] A first pipe line connected to the brake master cylinder, a second pipe line connected to the brake wheel cylinder, a reservoir capable of accommodating a required amount of hydraulic fluid, and communication between the first pipe line and the second pipe line. A supply switching valve that controls opening and closing, a discharge switching valve that controls opening and closing of communication between the second pipe line and the reservoir, a relief valve interposed in a passage connecting the discharge switching valve and the reservoir, and the reservoir and the relief. a hydraulic pump having a suction passage connected to a passage between the valves; a discharge passage of this hydraulic pump is connected to a passage connecting the discharge switching valve and the relief valve; or the first pipe line; and the reservoir is connected to the first pipe line; An actuator for a wheel braking device comprising an intake/discharge switching valve connected to a first conduit or a passage connecting the discharge switching valve and the relief valve.