JPS6349578A - Braking oil accumulating device - Google Patents

Abstract

PURPOSE:To disperse high pressure gas dissolved in a braking oil into the atmosphere by providing a braking oil opening means which opens a pressurized braking oil fed from an accumulating means to a atmospheric side at a fixed timing other than the time of traction control. CONSTITUTION:A traction controller has a wheel braking device 1 to brake each wheel of a vehicle and a braking oil accumulating device 3 which supplies the braking oil pressurized to a fixed pressure into said device 1 to carry out traction control when the number of revolutions of a front wheel differs from that of a rear wheel in accelerating the vehicle. The accumulating device 3 has an accumulator 31, a pump 33 and a solenoid valve 35 which can be switched so as to supply an accumulating oil to rear wheel brakes 17c, 17d at the time of the traction control. In this case, the accumulating device 3 is provided with a solenoid valve 39 which can be switched so as to return the braking oil in the accumulator 31 to a reservoir 37 at fixed timing other than the time of the traction control.

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention [Field of Industrial Application] The present invention relates to a brake oil pressure accumulating device for accumulating brake oil used for braking to a predetermined high pressure using compressed gas.

[Prior Art] A traction control device or an anti-skid control device that controls the braking force of a wheel based on a wheel slip rate or the like requires a brake oil pressure accumulation device that accumulates brake oil at a high pressure. BACKGROUND ART Conventionally, as such a brake oil pressure accumulation device, one is known that uses compressed sealed gas to maintain brake oil at a high pressure via a rubber membrane or the like.

Figure 3 shows a brake oil pressure accumulator TS that incorporates a brake oil pressure accumulation means (accumulator) AC using sealed gas and a solenoid valve EB that supplies high-pressure brake oil to the rear wheel braking system. This shows the hydraulic system of the traction control device. In such a traction control device, when the brake pedal BP is depressed during normal driving, the front and rear wheels of the vehicle are braked by the wheel braking system BS. If there is a difference in rotation speed between the two, the brake oil pressure accumulator TS
The solenoid valve EB is switched to supply high-pressure brake oil stored in an accumulator AC as a brake oil pressure storage means to the rear wheel braking system, thereby braking the rear wheels.

[Problems to be Solved by the Invention] A brake oil pressure accumulator used in a brake system such as the above-mentioned traction control device supplies brake oil to a wheel braking system that instantaneously brakes wheels using a predetermined compressed high-pressure gas. Although it has the excellent effect of being able to do the following, the following problems were considered.

In a brake fluid pressure accumulating means such as an accumulator, a predetermined compressed high-pressure gas (usually 100 to 20
(0 atm) and the brake oil are separated by a rubber membrane, etc., but because the compressed gas is at a high pressure, or due to aging of the rubber membrane, the shielding effect decreases, and the high pressure gas is separated from the rubber. A phenomenon occurred in which the oil gradually penetrated the membrane and dissolved into the brake fluid. When the high-pressure gas dissolved in this brake fluid flows into the low-pressure wheel braking system BS,
Here the volume expands. As a result, problems such as increased pedal loss stroke when the brake pedal is depressed and problems such as poor pedal feel were considered.

The brake fluid pressure accumulating device of the present invention is intended to solve the above-mentioned problems.

[Means for solving the problem] The brake oil pressure accumulation control device 2 of the present invention includes a brake oil pressure accumulation means for accumulating brake oil used for braking to a predetermined high pressure using compressed gas; Brake oil supply means for supplying brake oil to brake oil pressure accumulation means; The brake fluid releasing means is configured to release the pressurized brake fluid in the brake fluid pressure accumulating means to the atmosphere at a predetermined timing.

Here, the brake oil pressure accumulating means is a means for accumulating brake oil used for braking the wheels of a vehicle to a predetermined high pressure using compressed gas, and is a means for accumulating brake oil used for braking the wheels, etc. of a vehicle to a predetermined high pressure, and is a means for accumulating brake oil to a predetermined high pressure using compressed gas. It may be constructed so that the gas enclosed in oil is compressed and the brake oil is stored at a predetermined high pressure, or alternatively, the gas compressed by a compressor or the like is supplied and sealed to accumulate the brake oil at a predetermined high pressure. It may be configured to do so.

The brake oil release means is a means for releasing the brake oil contained in the brake oil pressure accumulation means to the atmosphere at a predetermined timing, and at least at a timing other than when the brake oil in the brake oil pressure accumulation means is used to brake the wheels. It may be configured to release the oil to the atmosphere.

[Function] The brake oil pressure accumulating device of the present invention having the above-mentioned structure functions as follows.

The brake oil pressure accumulation device of the present invention accumulates the brake oil supplied by the brake oil supply means to a predetermined high pressure by the brake oil pressure accumulation means using compressed gas, and
The pressurized brake oil in the brake oil pressure accumulation means is released to the atmosphere by the brake oil release means at a predetermined timing other than when the brake oil pressurized in the brake oil pressure accumulation means is used to perform the above-mentioned braking. work.

[Example] Next, a preferred example will be described with reference to the drawings in order to further clarify the configuration of the brake oil pressure accumulating device of the present invention.

FIG. 1 is a schematic configuration diagram showing the configuration of a traction control device incorporating a brake oil pressure accumulating device according to an embodiment of the present invention.

As shown in the figure, this traction control device mainly consists of a wheel braking device 1 that brakes each wheel of a vehicle, and a wheel braking device 1 that applies brake oil at a predetermined pressure to the wheels when a rotational speed difference occurs between the front wheels and the rear wheels during acceleration. A brake oil pressure accumulating device 3 that operates to supply the brake fluid to the braking device 1 to perform so-called traction control.
, etc.

As is well known, the wheel braking device 1 includes a booster 13 that increases the driver's depression force on the brake pedal 11, a mask cylinder 15 that converts the increased depression force by the booster 13 into hydraulic pressure, and a brake cylinder 15 that applies pressure to the left and right front wheels of the vehicle. The brake oil pumped from the mask cylinder 15 is supplied to the wheel cylinders 17a, 17b that perform braking of the left and right rear wheels, and the wheel cylinders 17c, 17d that brake the left and right rear wheels, and to each of these wheel cylinders 17a, 17b, 17c, and 17d. It is composed of solenoid valves 19a, 19b, 19c, 19d, etc. The constant pressure reservoirs 21a and 21b are for storing brake oil at a predetermined pressure by the restoring force of a spring, and the pumps 23a and 23b are for returning the brake oil to the mask cylinder 15. In addition, check valves 25a, 25b, 25c are provided in flow paths that bypass the solenoid valves 19a, 19b, 19c, and 19d, respectively.
, 25d are provided. Here, the operation of the wheel braking device 1 when the brake pedal 11 is depressed has been described, but the solenoid valve 19a is controlled by the traction controller (not shown).

19b, 19c, and 19d are activated, and it goes without saying that the present traction control device operates to perform 1 to traction control.

The brake oil pressure accumulator 3 includes an accumulator 31 filled with nitrogen (NZ) gas, and a pump that supplies brake oil to the accumulator 31 until the brake oil in the accumulator 31 reaches a predetermined pressure (about 150 atmospheres in this embodiment). 3
3 and 1 to a solenoid valve 35 that operates to supply brake oil in the accumulator 31 to the wheel cylinder 17C217d on the rear wheel side when it is determined by the traction controller to perform traction control, and a predetermined timing other than during traction control. It is comprised of three solenoid valves that function to return the brake fluid in the accumulator 31 to the reservoir 37 on the atmospheric pressure side, and an electronic control unit (ECU>41 etc.) that opens and closes the solenoid valve 39.

The electronic control device 41 is configured as a logic operation circuit using a so-called microcomputer, etc., and receives external inputs such as a brake switch sensor 43 that turns on when the brake pedal 11 is depressed, and a vehicle speed sensor 45 that detects the vehicle speed. It is configured to open and close three solenoid valves based on the base.

Next, the operation of the brake fluid pressure accumulator of this embodiment will be described with a focus on the operation of the solenoid valve 39.

The solenoid valve 39 is controlled by the electronic control unit 41 according to the flowchart shown in FIG. 2, but the process shown in FIG. 2 is executed only once after the ignition switch of the vehicle is turned on.

As shown in the flowchart of FIG. 2, the brake fluid pressure accumulating neck 3 of this embodiment operates when the driver depresses the brake pedal and the brakes are in operation, and the vehicle speed is above a predetermined speed (steps 100 to 130). ), for a predetermined time (several 10 m5 in this embodiment), the solenoid valve 39 is opened (steps 110 to 160), and the high pressure brake oil in the accumulator 31 is released to the atmospheric pressure side of the reservoir 37. As a result, the accumulator The high-pressure N2 gas that passes through the rubber membrane 31a in the reservoir 31 and slowly dissolves into the brake oil expands on the atmospheric pressure side of the reservoir 37 and is released to the atmosphere.
At 20, a state in which traction control is not performed is detected. That is, it is detected that the brake pedal 11 is depressed when the vehicle speed is higher than a predetermined speed (70 to BO km/h in this embodiment).

On the other hand, when there is a possibility that traction control will be performed (steps 110 to 120), or after the process of opening the solenoid valve 39 (steps 140 to 160) is performed, the solenoid valve 39
is in a closed state (step 170). Thereby, the traction controller that performs 1-traction control can perform traction control at any time using the brake oil that is brought to a predetermined high pressure by the pump 33 and stored in the accumulator 31 at a predetermined high pressure. That is, when performing traction control, high-pressure brake oil in the accumulator 31 is supplied to the wheel cylinders 17c, 17 on the contact wheel side via the solenoid valve 35.
d.

According to the brake oil pressure accumulating device of this embodiment described in detail above, the high pressure brake oil in the accumulator 31 can be returned to the reservoir 37 by opening the three solenoid valves when there is no possibility of traction control being performed. Can be done. As a result, the high-pressure N2 gas that has penetrated the rubber membrane in the accumulator 31 and is dissolved in the brake oil can be released to the atmosphere, and the brake oil that does not have high-pressure N2 gas dissolved in it can be used for traction control. It has the excellent effect of being able to As a result, high-pressure N2 gas expands in the brake system of the wheel braking device 1, resulting in problems such as increased pedal loss stroke of the brake pedal 11, poor pedal feel, or even an unexpected accident. This has the effect of being able to sufficiently solve the problem.

Although one embodiment of the present invention has been described in detail above, it goes without saying that the brake fluid pressure accumulating device of the present invention can be implemented in various forms without departing from the gist of the present invention. For example, in this embodiment, the process shown in the flowchart of FIG. It may be configured integrally with or,
In this embodiment, the brake oil pressure accumulating device of the present invention is incorporated into a brake system that performs traction control, but it is also possible to apply the present invention to hydraulic control of machine tools and the like.

Effects of the Invention According to the hazy brake oil pressure accumulation device of the present invention, pressurized brake oil in the brake oil pressure accumulation means can be released to the atmosphere by the brake oil release means at a predetermined timing. This allows the high-pressure gas dissolved in the brake fluid in the brake fluid pressure accumulating means to be released to the atmosphere, and has the excellent effect of allowing brake fluid that does not contain dissolved high-pressure gas to be used for braking. . As a result, the high-pressure gas does not expand in the brake system that brakes the wheels, resulting in problems such as increased pedal loss stroke and poor pedal feel.
Alternatively, this has the effect of sufficiently solving the problem of causing an unexpected accident.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing the configuration of a traction control device incorporated in a brake fluid pressure accumulating device 3 according to an embodiment of the present invention, and FIG. 2 is a flowchart showing the processing performed by an electronic control device 41 that opens and closes the solenoid valve. ,
FIG. 3 is a schematic configuration diagram showing a brake system equipped with a conventionally used traction control device. 1... Wheel braking device 3... Brake oil pressure accumulating device 31... Accumulator 33... Pump 39... Solenoid valve AC... Accumulator BS... Wheel braking system EB... Solenoid valve TS ...Brake oil pressure accumulator

Claims (1)

[Scope of Claims] A brake oil pressure accumulation means for accumulating brake oil used for braking to a predetermined high pressure using compressed gas, and a brake oil supply means for supplying brake oil to the brake oil pressure accumulation means. In the brake fluid pressure accumulating device, the pressurized brake fluid in the brake fluid pressure accumulating means is transferred to the atmosphere at a predetermined timing other than when performing the braking using the pressurized brake fluid in the brake fluid pressure accumulating means. A brake oil pressure accumulating device comprising a brake oil release means for releasing the brake oil.