JPH0567464B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a wheel braking device for a vehicle,
In particular, the present invention relates to an actuator for a wheel braking device having an anti-skid control function (a function that prevents the wheels from locking when the vehicle is braked) and a traction control function (a function that prevents the wheels from slipping when the vehicle starts or accelerates).

[Conventional technology]

This type of actuator has been proposed in the prior art, for example, in Japanese Patent Laid-Open No. 60-38243. However, the actuator proposed in the publication is combined with a hydraulic booster equipped with a hydraulic pump, an accumulator, etc., and the hydraulic fluid for traction control is supplied to the accumulator of the hydraulic booster. It is designed to be introduced through a bypass conduit.

[Problem that the invention seeks to solve]

For this reason, when the above-mentioned conventional actuator is installed on a vehicle, it is connected to the hydraulic booster and wheel cylinder via piping, and
It is necessary to connect piping to the accumulator of the hydraulic pressure booster (for this reason, a new piping connection part must be installed on the accumulator), making it difficult to install on the vehicle. If the booster is not a hydraulic booster but a vacuum booster, for example, it is necessary to separately provide a hydraulic pump or the like just to obtain pressure fluid for traction control. Concomitantly with the above, the wheel braking device becomes 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 conduit connected to a brake master cylinder, a second conduit connected to a brake wheel cylinder, and a required amount of hydraulic fluid. a reservoir that can be accommodated; 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; A hydraulic pump having a suction passage connected via a valve, suction switching means for controlling opening/closing of communication between the suction passage of the hydraulic pump and the first pipe line, and a discharge passage of the hydraulic pump. and a second discharge switching means for controlling opening and closing of communication between the hydraulic pump and the first pipe line, and a second discharge switching means for controlling the formation of communication between the discharge line of the hydraulic pump and the second pipe line. There are certain characteristics.

[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. The following operations can be obtained during anti-skid control and traction control).

(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 line and the second pipe line, the discharge switching valve blocks communication between the second pipe line and the reservoir, and the suction switching means connects the first pipe line to the second pipe line. the first pipe line and the suction line of the hydraulic pump are disconnected from each other, and the first discharge switching means communicates the discharge line of the hydraulic pump with the first line,
Since the second discharge switching means cuts off communication between the discharge path of the hydraulic pump and the second pipe line, the hydraulic pressure in the brake master cylinder is applied to the brake wheel cylinder to brake the wheels.

- At the time of anti-skid control At this time, the suction switching means cuts off communication between the first pipe line and the suction line of the hydraulic pump, and the first discharge switching means connects the discharge line of the hydraulic pump and the first pipe line. ,
The second discharge switching means cuts off communication between the discharge path of the hydraulic pump and the second pipe line, and (a) the supply switching valve switches between the first pipe line and the second pipe line depending on the locked state of the wheels during vehicle braking. By cutting off the communication between the two pipes and allowing the discharge switching valve to communicate the second pipe with the reservoir, the hydraulic pressure in the second pipe decreases and the wheel braking force decreases.(b) Supply The switching valve cuts off communication between the first pipe line and the second pipe line, and the discharge switching valve cuts off communication between the second pipe line and the reservoir, so that the hydraulic pressure in the second pipe line is maintained and the wheel (c) The supply switching valve connects the first pipe line and the second pipe line, and the discharge switching valve cuts off communication between the second pipe line and the reservoir, so that the second pipe line The hydraulic pressure in the first conduit (discharge pressure of the hydraulic pump) is supplied into the conduit, thereby increasing the wheel braking force, thereby optimally preventing the wheels from locking.

- During traction control At this time, the supply switching valve cuts off communication between the first pipe and the second pipe, and the discharge switching valve cuts off communication between the second pipe and the reservoir, depending on the slippage of the wheels when the vehicle starts or accelerates. The suction switching means connects the first pipe line with the suction line of the hydraulic pump, the first discharge switching means cuts off communication between the discharge line of the hydraulic pump and the first pipe line, and the suction switching means connects the first pipe line with the suction line of the hydraulic pump. The discharge switching means communicates the discharge path of the hydraulic pump with the second pipe line so that the pressure liquid discharged from the hydraulic pump is supplied to the second pipe line.
The wheels are braked to optimally prevent wheel slippage when starting or accelerating the vehicle.

〔Effect of the invention〕

The actuator according to the invention connects the first conduit to the brake master cylinder and the second conduit.
Installation to the vehicle is completed by connecting the conduit to the brake wheel cylinder, so
There is no need to change the configuration of the existing brake system, and it is extremely easy to install on vehicles. Since the hydraulic pump functions as a hydraulic pressure source during anti-skid control and also functions as a hydraulic pressure source during traction control, the actuator has a compact configuration and can be made smaller and lighter. In conjunction with the above-mentioned effects, the wheel braking device including the actuator becomes inexpensive. Effects such as these can be expected.

〔Example〕

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

1 and 2 show a first embodiment of the present invention. In the vehicle hydraulic wheel braking device shown in FIG. , simply referred to as a master 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 have been omitted).

The actuator A has a first pipe line 21 connected to the master cylinder 11 and a wheel cylinder 12.
It is equipped with a second pipe line 22 connected to a reservoir 23 capable of accommodating a required amount of working fluid, and a supply switching valve 24, a discharge switching valve 25, a suction switching valve 26,
A discharge switching valve 27 is provided, as well as a check valve 28 and a hydraulic pump 29.

The supply switching valve 24 is a 2-port 2-position electromagnetic on-off valve, which communicates the pipe line 21 connected to the master cylinder 11 with the pipe line 22 connected to the wheel cylinder 12 during demagnetization, and communicates the pipe line 21 with the pipe line 22 connected to the wheel cylinder 12 during magnetization.
The communication between the pipe line 22 and the pipe line 22 is cut off. In addition, the discharge switching valve 2
5 is a 2-port 2-position electromagnetic on-off valve, which cuts off communication between the pipe line 22 and the reservoir 23 during demagnetization;
Further, during excitation, the conduit 22 and the reservoir 23 are communicated. Therefore, the switching operation (demagnetization, excitation) of both the switching valves 24 and 25 is controlled by an electric control device (not shown), and when there is no need to brake the wheels (driving wheels) 13, As shown in the figure, both are demagnetized, and during anti-skid control, demagnetization and excitation are repeated (switched) depending on the locked state of the wheels 13, and furthermore, during traction control, depending on the slip state of the wheels 13. Accordingly, only the supply switching valve 24 is energized.

The reservoir 23 is equipped with a piston 23a and a spring 23b, and is capable of accommodating the hydraulic fluid that is returned through the discharge switching valve 25. It is said that it can be supplied. The hydraulic pump 29 is designed to be constantly driven by an electric motor (not shown) when the vehicle is operating.
The hydraulic fluid in the suction passage 29a is sucked into the discharge passage 29.
b.

The suction switching valve 26 is an on-off valve that operates using the hydraulic pressure in the pipe line 21 as pilot pressure, and as shown in FIG.
It is equipped with b. This suction switching valve 26
If the hydraulic pressure in 1 is low, the pipe line 21 and hydraulic pump 2
The suction passages 29a of 9 are communicated with each other, and when the hydraulic pressure in the pipe line 21 is high, the communication between the pipe line 21 and the suction passage 29a is cut off.

The discharge switching valve 27 is a 3-port 2-position electromagnetic switching valve, and when demagnetized, the discharge passage 29 of the hydraulic pump 29 is
At the same time, the communication between the pipe line 22 and the discharge passage 29b is cut off, and the discharge passage 29b of the hydraulic pump 29 is made to communicate with the pipe line 22, and at the same time, the communication between the pipe line 22 and the discharge passage 29b is interrupted. The communication between 29b and 29b is cut off. The switching operation (demagnetization, excitation) of the discharge switching valve 27 is controlled by an electric control device (not shown), and is energized only during traction control.

The actuator A of this embodiment configured as described above can be installed on a vehicle by connecting the first conduit 21 to the master cylinder 11 and the second conduit 22 to the wheel cylinder 12. The following operations are obtained when the vehicle is not braking and when the wheels are braking (normal braking, anti-skid control, and traction control).

(When wheels are not braked) At this time, the master cylinder 11 is in a non-operating state and no hydraulic pressure is generated, and the supply switching valve 24 connects 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.

(During wheel braking) - During normal braking At this time, the supply switching valve 24 is switched to the first conduit 21.
and the second pipe line 22, the discharge switching valve 25 blocks the communication between the second pipe line 22 and the reservoir 23, and the suction switching valve 26 allows the first pipe line 21 and the suction line 29a of the hydraulic pump 29 to communicate with each other. Since the discharge switching valve 27 connects the discharge passage 29b of the hydraulic pump 29 to the first pipe line 21, the hydraulic pressure in the master cylinder 11 is applied to the wheel cylinder 12 and the wheels 13 are braked.

- During anti-skid control At this time, the suction switching valve 26 is switched to the first pipe line 21.
The communication between the suction passage 29a of the hydraulic pump 29 and the discharge passage 29a of the hydraulic pump 29 is cut off.
9a and the first conduit 21, and depending on the locked state of the wheels 13 during vehicle braking, (a) the supply switching valve 24 cuts off communication between the first conduit 21 and the second conduit 22. , and the discharge switching valve 25 is connected to the second pipe line 22
(b) By communicating the fluid pressure in the second pipe line 22 with the reservoir 23, the wheel braking force is reduced. By blocking the communication and the discharge switching valve 25 blocking the communication between the second pipe line 22 and the reservoir 23, the hydraulic pressure in the second pipe line 22 is maintained and the wheel braking force is maintained. c) 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 reservoir 23, so that the inside of the second pipe line 22 is The hydraulic pressure in the first conduit 21 (discharge pressure of the hydraulic pump 29) is supplied to the pump 21, thereby increasing the wheel braking force, thereby optimally preventing the wheels 13 from locking.

- At the time of traction control At this time, the supply switching valve 24 is set to the first
The communication between the pipe line 21 and the second pipe line 22 is cut off, the discharge switching valve 25 cuts off the communication between the second pipe line 22 and the reservoir 23, and the suction switching valve 26 cuts off the communication between the first pipe line 21 and the hydraulic pump 29. The suction passage 29a is connected to the second pipe line 22, and the discharge switching valve 27 connects the discharge passage 29b of the hydraulic pump 29 to the second pipe line 22.
In order to supply the pressurized fluid discharged from the vehicle, the wheels 13 are braked, thereby optimally preventing the wheels 13 from slipping when the vehicle starts or accelerates.

As is clear from the above description, when the actuator A of this embodiment is installed on a vehicle, the first conduit 21 is connected to the master cylinder 11 and the second conduit 22 is connected to the wheel cylinder 12. Since installation to the vehicle is completed, there is no need to change the configuration of the existing brake system at all, and installation to the vehicle is extremely easy. Since the hydraulic pump 29 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 becomes compact and can be made smaller and lighter. In addition to the above-mentioned effects, the wheel braking device including the actuator A becomes inexpensive. Effects such as these can be expected.

FIG. 3 shows a second embodiment of the invention,
In this embodiment, a suction switching valve 26A is used in place of the suction switching valve 26 of the first embodiment. The suction switching valve 26A uses the hydraulic pressure in the first pipe line 21 and the second pipe line 22 as a pilot pressure,
The second pipe 2 is controlled by the anti-skid control.
It operates only when the hydraulic pressure in the first pipe line 21 becomes lower than the liquid pressure in the first pipe line 21 by a predetermined value or more, and the communication between the first pipe line 21 and the suction passage 29a of the hydraulic pump 29 is cut off. The number of switching operations is reduced compared to the first embodiment.

FIG. 4 shows a third embodiment of the invention,
In this embodiment, a suction switching valve 26B is used in place of the suction switching valve 26 of the first embodiment. The suction switching valve 26B is a 2-port 2-position electromagnetic on-off valve, which blocks communication between the pipe line 21 and the suction passage 29a of the hydraulic pump 29 when demagnetized, and closes the communication between the pipe line 21 and the suction passage 29a of the hydraulic pump 29 when energized. Road 29a
communicate. The switching operation (demagnetization, excitation) of the suction switching valve 26B is controlled by an electric control device (not shown), and is energized only during traction control. Further, in this embodiment, the hydraulic pump 29 is driven during anti-skid control and traction control.

5 and 6 show a fourth embodiment of the present invention. In this embodiment, a discharge switching valve 31 is used in place of the suction switching valve 26 and the discharge switching valve 27 of the first embodiment. A suction/discharge switching valve 32 is employed. The discharge switching valve 31 is a 2-port 2-position electromagnetic on-off valve, which blocks communication between the pipe line 22 and the discharge passage 29b of the hydraulic pump 29 when demagnetized, and closes communication between the pipe line 22 and the discharge passage 29b of the hydraulic pump 29 when energized. road 29b
communicate. The switching operation (demagnetization, excitation) of the discharge switching valve 31 is controlled by an electric control device (not shown), and is energized only during traction control. On the other hand, the suction/discharge switching valve 32 has a spool 32a and a spring 3 as shown in FIG.
It is a 4-port 2-position switching valve equipped with 2b, which uses the hydraulic pressure in the pipe line 21 as the pilot pressure, and the hydraulic pressure in the pipe line 21.
When the hydraulic pressure in 1 is low, in the non-operating state shown in the figure, the pipe line 21 and the suction passage 29a of the hydraulic pump 29 are communicated, and at the same time, the communication between the pipe line 21 and the discharge passage 29b of the hydraulic pump 29 is cut off. , and when the hydraulic pressure in the pipe line 21 exceeds a set value, the hydraulic pump 2 is activated.
The discharge passage 29b of the hydraulic pump 29 and the pipe line 21 are made to communicate with each other, and at the same time, the communication between the pipe line 21 and the suction passage 29b of the hydraulic pump 29 is cut off. In addition, in this example,
A relief valve 33 is interposed between the suction passage 29a and the discharge passage 29b of the hydraulic pump 29.

FIG. 7 shows a fifth embodiment of the present invention,
In this embodiment, the injection and
Suction/discharge switching valve 32A instead of discharge switching valve 32
has been adopted. The suction/discharge switching valve 32A is
It is a 4-port 2-position switching valve, and the hydraulic pressure in the pipe line 21 and the liquid pressure in the pipe line 22 are used as pilot pressure, and the liquid pressure in the second pipe line 22 is changed to the first pipe by anti-skid control. The hydraulic pump 2 operates only when the hydraulic pressure in the passage 21 is lower than a predetermined value.
9, the discharge passage 29b of the hydraulic pump 29 and the pipe line 21 are made to communicate with each other, and at the same time the communication between the pipe line 21 and the suction passage 29b of the hydraulic pump 29 is cut off. It is designed to reduce the number of

[Brief explanation of the drawing]

Fig. 1 is a schematic configuration diagram showing a first embodiment of the present invention, Fig. 2 is an enlarged sectional view of the intake switching valve portion shown in Fig. 1, and Fig. 3 is a schematic diagram showing a second embodiment of the invention. 4 is a schematic diagram showing a third embodiment of the present invention, FIG. 5 is a schematic diagram showing a fourth embodiment of the present invention, and FIG. 6 is a diagram showing the inhalation/exhalation shown in FIG. 4. FIG. 7 is an enlarged sectional view of the switching valve portion, and is a schematic configuration diagram showing a fifth embodiment of the present invention. Explanation of symbols, 11... Master cylinder, 12...
...Wheel cylinder, 13...Wheel, 21...First conduit, 22...Second conduit, 23...Reservoir,
24... Supply switching valve, 25... Discharge switching valve, 2
6, 26A, 26B...Suction switching valve, 27...Discharge switching valve, 28...Check valve, 29...Hydraulic pressure pump, 29a...Suction path, 29b...Discharge path, 3
1... Discharge switching valve, 32, 32A... Suction/discharge switching valve, A... Actuator.

Claims (1)

[Claims] 1. A first pipe connected to the brake master cylinder, a second pipe connected to the brake wheel cylinder.
a pipe line, a reservoir capable of accommodating a required amount of working fluid, a supply switching valve that controls opening and closing of communication between the first pipe line and the second pipe line, and an opening and closing control of communication between the second pipe line and the reservoir. a hydraulic pump having a suction passage connected to the reservoir via a check valve, and a suction switch for controlling opening/closing of communication between the suction passage of the hydraulic pump and the first pipe line; means, a first discharge switching means for controlling opening and closing of communication between the discharge passage of the hydraulic pump and the first pipe line, and a first discharge switching means for controlling opening and closing of communication between the discharge passage of the hydraulic pump and the second pipe line. An actuator for a wheel braking device comprising two discharge switching means. 2. The actuator for a wheel braking device according to claim 1, wherein the first discharge switching means and the second discharge switching means are constituted by one switching valve. 3. The actuator for a wheel braking device according to claim 1, wherein the first discharge switching means and the suction switching means are constituted by one switching valve.