JPH064408B2 - Wheel brake actuator - Google Patents

Description

The present invention relates to a wheel braking device for a vehicle, and more particularly to an anti-skid control function (a function for preventing wheel lock during braking of the vehicle) and a traction control function (vehicle. The present invention relates to an actuator of a wheel braking device having a function of preventing wheel slip during starting and acceleration.

[Conventional technology]

An actuator of this type has hitherto been disclosed in, for example, JP-A-60-
It is proposed in Japanese Patent No. 38243. Therefore, the actuator proposed in the publication is a hydraulic pump,
It is combined with a hydraulic booster equipped with an accumulator and the like, and moreover, a hydraulic fluid for traction control is introduced from the accumulator of the hydraulic booster via a bypass line.

[Problems to be solved by the invention]

Therefore, in the above-mentioned conventional actuator,
When mounting on a vehicle, it is necessary to connect to the hydraulic booster and the wheel cylinder by piping, and also connect to the hydraulic booster's accumulator (for this purpose, a new piping connection must be provided in the accumulator),
Poor attachment to the vehicle. When the booster is not a hydraulic booster but a vacuum booster, for example, a hydraulic pump or the like needs to be separately provided only to obtain a pressurized liquid for traction control. In addition to the above and, the wheel braking device becomes expensive. There is a problem such as.

[Means for Solving Problems] The present invention has been made to solve the above-mentioned problems, and the above-mentioned actuator is connected to a brake master cylinder in a first conduit and a brake wheel cylinder in a first conduit. 2 conduits, a reservoir that can store the required amount of differential liquid,
A supply switching valve that controls opening and closing of communication between the first pipeline and the second pipeline, a discharge switching valve that controls opening and closing of communication between the second pipeline and the reservoir, and the discharge switching valve and the reservoir are connected. A relief valve interposed in the passage, a hydraulic pump having an intake passage connected to the passage between the reservoir and the relief valve, and a discharge passage of the hydraulic pump connecting the discharge switching valve and the relief valve. It is characterized in that it is configured to include an intake / discharge switching valve that is connected to a passage or the first pipeline and that connects the reservoir to the first pipeline or a passage that connects the discharge switching valve and the relief valve. .

[Operation of the invention]

The actuator according to the present invention is completely attached to the vehicle by connecting the first pipeline to the brake master cylinder and the second pipeline to the brake wheel cylinder, and the wheels are not braked and the wheels are braked (normal brake). Time,
The following operations are obtained during anti-skid control and traction control).

(While the wheel is not braked) At this time, the brake master cylinder is in the non-actuated state, no hydraulic pressure is generated, and the supply switching valve connects the first pipe line and the second pipe line. No hydraulic pressure is applied to the wheel cylinders and the wheels are not braked.

(Wheel braking) ・ Normal braking At this time, the supply switching valve connects the first conduit and the second conduit, the discharge switching valve blocks communication between the second conduit and the reservoir, and the intake / discharge switching valve Connects the first pipe line to the discharge line of the hydraulic pump and the passage connecting the discharge switching valve and the relief valve to the reservoir, so that the hydraulic pressure in the brake master cylinder is applied to the brake wheel cylinder to brake the wheel. It

At the time of anti-skid control At this time, the intake / discharge switching valve connects the first pipe line to the discharge line of the hydraulic pump and the passage connecting the discharge switching valve and the relief valve to the reservoir, so that the wheel during braking of the vehicle can be controlled. (A) the supply switching valve blocks communication between the first pipeline and the second pipeline, and the discharge switching valve communicates the second pipeline with the reservoir according to the lock state of the second pipeline. The pressure liquid inside flows into the reservoir through the discharge switching valve and the intake / discharge switching valve, and the hydraulic pressure inside the second pipe line decreases to reduce the wheel braking force. (B) The supply switching valve works on the first pipe line And the second pipeline, and the discharge switching valve blocks communication between the second pipeline and the reservoir, so that the hydraulic pressure in the first pipeline (the discharge pressure of the hydraulic pump) in the second pipeline. Is supplied to each wheel to increase the braking force of the wheels, and the wheels are optimally prevented from locking. To be done.

・ At traction control At this time, the intake / 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. In response to the wheel slip, the supply switching valve blocks the communication between the first pipeline and the second pipeline, and the discharge switching valve communicates the passage connecting the second pipeline, the discharge switching valve and the relief valve, The wheels are braked so that the hydraulic fluid discharged from the hydraulic pump (preliminarily boosted by the relief valve) is supplied to the second pipeline through the intake / discharge switching valve and the discharge switching valve so that the vehicle starts. -While accelerating, wheel slippage is optimally prevented.

〔The invention's effect〕

The actuator according to the present invention is installed in a vehicle by connecting the first pipe line to the brake master cylinder and the second pipe line to the brake wheel cylinder. It does not need to be changed at all, and it is extremely easy to mount on a vehicle. Since the hydraulic pump functions as a hydraulic pressure source at the time of anti-skid control and at the same time as a hydraulic pressure source at the time of traction control, the structure of the actuator can be made compact, and the size and weight can be reduced. In addition to the above effects, the wheel braking device including the actuator becomes inexpensive. The effect such as can be expected.

〔Example〕

 Embodiments of the present invention will be described below with reference to the drawings.

1 to 3 show a first embodiment of the present invention, and in the vehicle hydraulic wheel braking system shown in FIG. 1, a brake master cylinder operated by a brake pedal 10 (hereinafter, simply referred to as "brake master cylinder"). 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 are omitted).

The actuator A includes a first conduit 21 connected to the master cylinder 11, a second conduit 22 connected to the wheel cylinder 12, and a reservoir 2 capable of accommodating a required amount of hydraulic fluid.
3, the supply switching valve 24, the discharge switching valve 2
5, a relief valve 26, a hydraulic pump 27, a suction / discharge switching valve 28, and a control valve 30.

The supply switching valve 24 is a 2-port 2-position electromagnetic on-off valve,
At the time of demagnetization, the conduit 21 connected to the master cylinder 11 and the conduit 22 connected to the wheel cylinder 12 are made to communicate with each other, and at the time of excitation, the communication between the conduit 21 and the conduit 22 is cut off. Further, the discharge switching valve 25 is a 2-port 2-position electromagnetic on-off valve, and when demagnetized, the conduit 22 and the passage 29 (relief valve 2
6 or connected to the reservoir 23 via the suction / discharge switching valve 28), and disconnects the conduit 22 during excitation.
And the passage 29 are communicated. Then, both switching valves 24, 2
The switching operation (demagnetization, excitation) of No. 5 is controlled by an electric control device (not shown), and when it is not necessary to brake the wheels (driving wheels) 13, both are demagnetized as shown and the During skid control, demagnetization and excitation are repeated (switching operation) according to the locked state of the wheels 13, and during traction control, both switching valves 24 and 25 are excited according to the slip state of the wheels 13. It has become so.

The reservoir 23 includes a piston 23a and a spring 23b, and can store the recirculated working fluid therein and can supply the working fluid contained therein to the suction passage 27a of the hydraulic pump 27. The relief valve 26 is interposed in a passage that connects the discharge switching valve 25 and the reservoir 23, and a passage 29 between the relief valve 26 and the discharge switching valve 25 has a discharge passage 27 b of the hydraulic pump 27 as shown in the figure. When the hydraulic pump 27 is driven by being connected to, the pump discharge pressure is set to the set pressure. The hydraulic pump 27 is constantly driven by an electric motor (not shown) when the vehicle is operating, and is configured to suck the working fluid in the suction passage 27a and discharge it to the discharge passage 27b.

The intake / discharge switching valve 28 is a switching valve that operates using the hydraulic pressure in the conduit 21 as a pilot pressure, and includes a spool 28a and a spring 28b, as shown in FIG. The suction / discharge switching valve 28 controls the pipeline 21 as shown in the figure when the hydraulic pressure in the pipeline 21 is substantially zero.
The discharge passage 27b of the hydraulic pump 27 is connected to the reservoir 23 via the relief valve 26 and the discharge switching valve 25.
When the hydraulic pressure in the pipe 21 is equal to or higher than a set value, the discharge passage 27b of the hydraulic pump 27 is connected to the control valve 3.
The reservoir 23 is connected to the passage 29 while being connected to the first conduit 21 via 0.

The control valve 30 is, as shown in FIG.
1 and a check valve 32, the differential pressure generating valve 31 does not open until the hydraulic pressure in the conduit 21 reaches a set value, and the intake / discharge switching valve 28 operates during braking to operate the conduit 2
1 has a function of connecting to the discharge passage 27b of the hydraulic pump 27 (a function of preventing hydraulic fluid from flowing from the pipeline 21 to the reservoir 23 during braking), and the check valve 32 is a pipeline. It has a function of allowing the flow to 21.

The actuator A of the present embodiment configured as described above is
The first pipe line 21 is connected to the master cylinder 11 and the second pipe line 22 is connected to the wheel cylinder 12 to complete the attachment to the vehicle. When the wheels are not braked and the wheels are braked (normal brake, anti-skid). During control,
The following operations can be obtained during traction control).

(While Wheels are Not Braked) At this time, the master cylinder 11 is in the non-actuated state, no hydraulic pressure is generated, and the supply switching valve 24 connects the first conduit 21 and the second conduit 22. Therefore, the hydraulic pressure is not applied to the wheel cylinder 12 and the wheel 13 is not braked. At this time, the hydraulic fluid discharged from the hydraulic pump 27 causes the suction / discharge switching valve 28 and the relief valve 26 to operate.
Circulates through.

(While braking wheel) -Normal braking At this time, the supply switching valve 24 connects the first conduit 21 and the second conduit 22 and the discharge switching valve 25 blocks the communication between the second conduit 22 and the passage 29. Since the intake / exhaust switching valve 28 is activated 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, the hydraulic pressure in the master cylinder 11 is applied to the wheel cylinder 12. Then, the wheels 13 are braked.

At the time of anti-skid control At this time, the intake / discharge switching valve 28 connects the first pipe 21 to the discharge passage 27b of the hydraulic pump 27 and the passage 29 to the reservoir 23, and locks the wheels 13 during vehicle braking. Depending on the state, (a) the supply switching valve 24 is connected to the first conduit 2
The communication between the first and second pipe lines 22 is cut off, and the discharge switching valve 25
Makes the second conduit 22 and the reservoir 23 communicate with each other, so that the pressure liquid in the second conduit 22 is discharged to the discharge switching valve 25 and
The action of flowing to the reservoir 23 through the discharge switching valve 28, decreasing the hydraulic pressure in the second pipe line 22 and decreasing the wheel braking force,
(b) The supply switching valve 24 blocks the communication between the first conduit 21 and the second conduit 22, and the discharge switching valve 25 blocks the communication between the second conduit 22 and the reservoir 23, so that the second pipe The action of retaining the hydraulic pressure in the passage 22 to retain the wheel braking force, (c)
The supply switching valve 24 connects the first conduit 21 and the second conduit 22 and the discharge switching valve 25 connects the second conduit 22 and the reservoir 23.
By shutting off the communication between the wheels, the hydraulic pressure in the first pipeline 21 (the discharge pressure of the hydraulic pump 27) is supplied to the second pipeline 22, and the wheel braking force is increased. 1
Locking of 3 is optimally prevented.

At the time of traction control At this time, as shown in the drawing, the intake / 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, so that the vehicle starts and accelerates. In response to the slip of the wheel 13 at the supply switching valve 24
Disconnects the communication between the first conduit 21 and the second conduit 22, and the discharge switching valve 25 allows the second conduit 22 and the passage 29 to communicate with each other.
The wheel 13 is braked so that the hydraulic fluid discharged from the hydraulic pump 27 (preliminarily boosted by the relief valve 26) is supplied to the pipeline 22 through the suction / discharge switching valve 28 and the discharge switching valve 25. Therefore, the slip of the wheels 13 is optimally prevented when the vehicle starts and accelerates.

As is clear from the above description, the actuator A of the present embodiment connects the first pipe line 21 to the master cylinder 11 and the second pipe line 22 to the wheel cylinder 12 when it is mounted on the vehicle. Since the installation on the vehicle is completed, there is no need to change the configuration of the existing brake system at all, and the installation on the vehicle is extremely good. Since the hydraulic pump 27 functions as a hydraulic pressure source at the time of anti-skid control and at the same time as a hydraulic pressure source at the time of traction control, the structure of the actuator A becomes compact and the size and weight can be reduced. In addition to the above effects, the wheel braking device including the actuator A becomes inexpensive. The effect such as can be expected.

FIG. 4 shows a second embodiment of the present invention. In this embodiment, a supply / discharge switching valve 24A is adopted in place of the supply switching valve 24 and the discharge switching valve 25 of the first embodiment. ing. The supply / discharge switching valve 24A is a 3-port 2-position electromagnetic switching valve, which connects the conduit 21 and the conduit 22 to each other during demagnetization and cuts off the communication between the conduit 22 and the passage 29. 29 is communicated, and the communication between the pipeline 21 and the pipeline 22 is blocked. The switching operation (demagnetization, excitation) of the supply / discharge switching valve 24A is controlled by an electric control device (not shown).
Switching is performed during anti-skid control and traction control.

Incidentally, in the first and second embodiments, the control valve 30
However, if the spring force of the intake / discharge switching valve 28 is reduced to improve the operation response of the intake / discharge switching valve 28, the present invention can be implemented without using the control valve 30. You can

FIG. 5 shows a third embodiment of the present invention. In this embodiment, the intake / discharge switching valve 28 of the second embodiment is shown.
An intake / discharge switching valve 28A is used instead of the control valve 30. The intake / discharge switching valve 28A is a 4-port 2-position electromagnetic switching valve, and is energized during normal braking and anti-skid control.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a first embodiment of the present invention, and FIG. 2 is an enlarged cross-sectional view of the intake / discharge switching valve portion shown in FIG.
FIG. 3 is an enlarged sectional view of the control valve portion shown in FIG.
FIG. 5 is a schematic configuration diagram showing a second embodiment of the present invention, and FIG. 5 is a schematic configuration diagram showing a third embodiment of the present invention. Explanation of reference numerals 11 ... Master cylinder, 12 ... Wheel cylinder, 13 ... Wheels, 21 ... First pipe line, 22 ...
Second pipe line, 23 ... Reservoir, 24 ... Supply switching valve, 25 ... Discharge switching valve, 24A ... Supply / discharge switching valve, 26 ... Relief valve, 27 ... Hydraulic pressure pump,
27a ... Intake passage, 27b ... Discharge passage, 28, 28
A ... Intake / discharge switching valve, 29 ... Passage connecting discharge switching valve and relief valve, A ... Actuator.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Noboru Noguchi 1 Toyota-cho, Toyota-shi, Aichi Prefecture Toyota Motor Co., Ltd. (72) Inventor Shin Nishi Nakanishi 1-cho, Toyota-shi, Aichi Toyota Motor Co., Ltd.

Claims (1)

[Claims] 1. A first connected to a brake master cylinder
A pipe line, a second pipe line connected to the brake wheel cylinder, a reservoir capable of containing a required amount of hydraulic fluid, 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 pipeline and the reservoir, a relief valve interposed in a passage that connects the discharge switching valve and the reservoir, and a passage that is connected between the reservoir and the relief valve. Hydraulic pump having a suction passage,
The discharge passage of this hydraulic pump is connected to the passage connecting the discharge switching valve and the relief valve or the first pipeline, and the reservoir is connected to the first pipeline or the discharge switching valve and the relief valve. An actuator for a wheel braking device including an intake / discharge switching valve connected to a passage.