JPS63265754A - Anti-skid device for automobile - Google Patents

Abstract

PURPOSE:To provide an anti-skid device equiped with hill hold functions in a simple manner by incorporating informations from a slope sensor, an advancing direction torque sensor, a reverse switch for a change speed gear and the like into a control unit for the anti-skid device. CONSTITUTION:When brake hydraulic pressure is applied to the braking device 4 of each wheel from a master cylinder 2 at the time of braking with a brake pedal 1 stepped in, a control unit 13 produces a control pattern repeating the decrease and increase in braking pressure based on wheel speed signals from a sensor 14 for applying an effective brake without locking wheels. And the control unit 13 incorporates hill holder informations from a slope sensor 16 detecting that a road is an uphill or of somethings, a torque sensor 17 detecting the advancing direction, a reverse switch 18 detecting the reverse position of a change speed gear and the like for comprising an anti-skid device equiped with hill holder functions in a simple manner. This constitution thereby enables added values for the anti-skid device to be enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an anti-skid device for a motor vehicle.

Conventional technology In hydraulic brake systems for automobiles, when braking is performed by depressing the brake pedal and hydraulic pressure is supplied from the master cylinder to the wheel cylinder, the rate and amount of decrease in wheel speed relative to the vehicle body speed is detected, and the rate and amount of decrease in wheel speed are detected. Various anti-skid devices have been developed in the past, which alternately control the pressure reduction and pressure increase of the supplied brake fluid pressure to perform effective braking without locking the wheels and losing directional stability. It has already been published in Japanese Patent Application Laid-Open No. 60-61354.

On the other hand, in order to make it easier to hold the brakes on a hill and start on a hill, as long as the clutch is off when braking and stopping on a hill, the braking will continue even if you release your foot from the -8 brake pedal. A brake fluid pressure holding valve is installed in the brake fluid pressure piping (generally called a hill holder) to maintain the brake fluid pressure as it is and release the brake retention state in conjunction with the clutch on operation at the time of starting. ) have already been developed in various ways, such as Utility Model Application Publication No. 55-33822.
No. 1, Japanese Patent Application Laid-Open No. 56-34550, etc.

Problems to be Solved by the Invention In recent years, automatic vehicles have become equipped with both an anti-skid device and a hill holder in order to improve safety during high-speed driving and to satisfy user demands for easier driving operations. However, providing two independent mechanisms such as the anti-skid device and the hill holder as described above in the brake hydraulic system is not only structurally complicated but also costly. It will be quite expensive.

The main object of the present invention is to solve the above-mentioned problems by providing an anti-skid device having a hill holder function.

Means for Solving the Problems The present invention provides a first control valve for pressurizing and In an automobile anti-skid system that performs braking control by repeating a control pattern in which the second control valve for pressure reduction is operated to reduce the hydraulic pressure in the brake system and then increase the pressure again, each control valve is operated from the master cylinder to the brake system. A signal from the control unit is sent to the main hydraulic pressure system that supplies brake fluid pressure to the wheel brake equipment when a brake is applied on an uphill road and the vehicle has stopped or reached an extremely low speed close to stopping.
A normally open third control valve is provided that switches to a one-way valve that is open from the master cylinder toward the brake system but is closed in the opposite direction, and the third control valve is switched to the one-way valve. However, when a predetermined vehicle start condition occurs, such as when a forward torque of a predetermined value or more is applied to the wheels or when the transmission is shifted to reverse, the control unit is switched to the open state by a signal from the control unit. It is characterized by being configured so that it can be replaced.

Effect As described above, when the vehicle reaches a braking stop or an extremely low speed close to stopping on an uphill road, the third control valve switches from the open state to the - direction valve state, and the brakes will not stop even if you release your foot from the brake pedal after stopping. The hydraulic pressure inside the device is not drained to the master cylinder side, and the brake is maintained. In this state, it is possible to further increase the braking force of the brake device by pressing the brake pedal more strongly.

When the accelerator pedal is pressed to start from this brake holding state and the forward torque acting on the wheels exceeds a predetermined value, the third control valve is switched to the open state by a signal from the control unit, and the hydraulic pressure of the brake system is released. This makes it easy to start on the pitch.

In addition, when the transmission is shifted to the reverse position in order to go backwards in the brake holding state as described above, the third control valve is switched to the open state by a signal from the control unit, and the hydraulic pressure of the brake device is released, making it possible to go backwards. becomes.

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

In the figure, 1 is the brake pedal, 2 is the master cylinder, and when the brake pedal 1 is depressed, the master cylinder 2
is activated, and the brake fluid pressure is supplied to the brake device 4 of each wheel (only the brake device of one wheel is shown in the diagram) through the main hydraulic line 3 consisting of pipes 31, 32 and 33. It looks like this.

The main hydraulic line 3 includes a normally open third control valve 5 that switches to a one-way valve when a hill hold signal S5 is issued from the control unit 13 (described later), and a hold valve from the control unit 13 (described later). A normally open first control valve 6 that is closed by a signal S2 is provided.

Reference numeral 7 denotes a sub-hydraulic pressure line that bypasses the downstream and upstream sides of the first control valve 6 of the main hydraulic line 3, and the sub-hydraulic line 7 is connected to a normally closed second control valve. 8 is opened, the pressure fluid in the brake device 4 is released to the reservoir 9 to reduce the pressure in the brake device 4, and the pressure fluid released to the reservoir 9 is pumped out by the operation of the electromagnetic pump 10 to the accumulator 11. It is composed of pipes 72 and 73 for storage, and a pipe 74 for sending the pressure liquid stored in the accumulator 11 to the upstream side of the first control valve 6 via the relief valve 12.

In the above, when the brake pedal 1 is depressed, hydraulic pressure is supplied from the master cylinder 2 to the brake device 4 through the main hydraulic pressure line 3, and the brake device 4 is activated. At the same time, the brake pedal switch 15 is activated and a braking signal S1 is input to the control unit 13, and the control unit 13 starts anti-skid operation when the wheels are likely to lock based on the wheel speed signal Sw from the wheel speed sensor 14. .

That is, for example, when the degree of decrease in wheel speed (deceleration) exceeds a set value, the control unit 13 issues a hold signal S2, closes the first control valve 6, and reduces the hydraulic pressure supplied from the master cylinder 2 to the brake device 4. The hydraulic pressure of the brake device 4 is maintained by shutting off, and when the wheel speed decreases to a certain set value with respect to the vehicle body speed, the control unit 13 issues a pressure reduction signal S3 and the pressure is passed through the second control valve 8 to the brake device 4. The pressure fluid in the reservoir 9 flows into the reservoir 9 through the pipe 33.71 to reduce the pressure in the brake device 4, and the pressure fluid flowing into the reservoir 9 is pumped out through the pipe 72 by the operation of the electromagnetic pump IO, and the pressure fluid flows into the reservoir 9 through the pipe 73. The hydraulic pressure in the accumulator 11 is applied via the relief valve 12 to the upstream side of the first control valve 6 which is in the closed state.

When the pressure in the brake device 4 is reduced as described above, the wheel speed increases due to road reaction force, and when the wheel speed recovers to a certain value, the control unit 13 stops the pressure reduction signal S3 and closes the second control valve 8. control unit 1 when the wheel rotation speed has recovered to near the vehicle body speed.
3 is the pressurization signal S4 (in this case, the hold signal S
2 is a pressurization signal), the first control valve 6 is switched to the open state, and the pressurized fluid stored in the accumulator 11 is supplied to the brake device 4, and the brake device 4 is pressurized. The wheel speed decreases due to pressure.

From then on, the control unit 13 outputs the hold signal S2r.
The depressurization signal S3 and the pressurization signal S4 are sequentially issued to alternately repeat depressurization and pressurization of the brake device 4, and in this way, effective braking is performed without locking the wheels.

During the anti-skid operation in which the brake device 4 is alternately depressurized and pressurized as described above, when the brake pedal l is released, the signal S1 from the brake pedal switch 15 disappears and the anti-skid function of the control unit 13 is activated. The skid control operation is stopped, the first control valve 6 is closed yE, and the second control valve 8 is closed! held in the system,
The hydraulic pressure of the brake device 4 is drained from the main hydraulic pressure line 3 to the master cylinder 2 side, and the braking is released.

When the brake pedal 1 is depressed to stop the brake pedal on an uphill road, the signal SO from the gradient sensor 16, which emits the signal SO when the road surface is uphill, is input to the control unit 13, and the brake signal S1 from the brake pedal switch 15 is input to the control unit 13. and the wheel speed signal Sw from the wheel speed sensor 14.
(zero signal) and the slope signal Sθ of the slope sensor 16, the control unit 13 determines that the brake is stopped on the uphill road, and sends the hill hold signal S5 to the third control valve 5.
The third control valve 5 is opened from the circular valve 7A1 in one direction, that is, from the master cylinder 2 side to the brake device 4 side, and is closed in the opposite direction.

In this state, even if the brake pedal 1 is released, the hydraulic pressure of the brake device 4 is not drained to the master cylinder 2 side, and the brake is maintained. In this case, if the braking force of the brake device 4 is insufficient, release your foot from the brake pedal 1 + iii. Depress the brake pedal 1 even more strongly to increase the hydraulic pressure of the brake device 4, and then press the brake pedal 1.
Move your foot further away to maintain braking.

In the above embodiment, when the road surface is uphill and the brake is stopped, the control unit 13 issues the hill hold signal S5 to the third control valve 5 to maintain the braking state, but when the road surface is uphill and the braking operation is performed. The control unit 13 may be configured to issue a hill hold signal S5 to the third control button t5 to maintain the brake when the vehicle speed reaches an extremely low speed (for example, 3 K!w/h or less) on the verge of stopping. .

When starting from this brake holding state, the forward torque acting on the wheels increases in response to the depression of the accelerator pedal, and a torque signal St is input to the control unit 13 from the torque sensor 17 that detects this torque. . Then, the control unit 13 stops transmitting the hill hold signal S5 in response to the torque signal St, and the third control valve 5 returns to its original state, and the hydraulic pressure of the brake device 4 is drained to the master cylinder 2 side to perform braking. is released, making it easy to start on the boarding road.

When the transmission is put into reverse gear in order to go backwards after braking to a stop on the uphill road, the reverse switch 18 is activated and sends a reverse signal Sr to the control unit 13, which causes the control unit 13 to activate the hill hold signal S5. Stops transmission and releases brake hold.

In this case, it is preferable that the transmission of the hill hold signal S5 is stopped with a certain time delay after the generation of the reverse signal Sr, and when the reverse signal Sr and the throttle valve opening exceed a predetermined value, the throttle The transmission of the hill hold signal S5 may be stopped by ANDing the throttle opening signal of a throttle opening sensor (not shown) which generates the opening signal, thereby releasing the brake hold.

If the driver opens the door and attempts to leave the vehicle while the brake is still being held, the door open signal Sd is input to the control unit 13 from the door switch 19, which is activated by opening the door, and the control unit 13 is activated. 13
The signal Sd activates an alarm device 20 such as a buzzer to issue a warning to the driver. In this case, when the parking lever is operated to apply the parking brake, the parking switch 21 issues a signal Sp to the control 0-1 unit 13, and the control 2-2) 13 sends a hill hold signal S.
5 is stopped, brake holding is released, and if the alarm 20 is operating, the operation of the alarm 20 is stopped.

Reference numeral 22 denotes an indicator light, which lights up in response to an output signal from the control unit 13 when the two-legged third control valve 5 is in the brake holding state to indicate that the brake is being held.

Furthermore, even if the key switch of the engine is turned off without applying the parking brake in the brake holding state, the control unit 13 activates the alarm 20 such as a buzzer to warn the driver to apply the parking brake.

The braking hydraulic pressure may be maintained by the third control valve 5 for all wheels or only for a limited number of wheels, for example, one system or one wheel.

By incorporating the information of each sensor switch necessary for the hill holder into the control unit 13 for anti-skid control as described above, the hill holder function can be easily realized using a conventional anti-skid system. .

In addition, in terms of the anti-skid operation, the first control valve 6
is closed, the electromagnetic pump 10 is activated, and pressure fluid is supplied via the relief valve 12 to the main hydraulic line 3 on the t side above the 11th υ) control valve 6. For example, when the electromagnetic pump 10
Based on the activation signal of the control unit) 13, the third
Hill hold signal S5 that switches the control valve 5 to the one-way valve side
It is preferable to configure the structure so as to emit a brake pedal.By doing so, the pulsation of hydraulic pressure caused by the operation of the electromagnetic pump 10 will not act on the master cylinder 2 side, thereby preventing the problem of brake pedal kickback. It can be prevented.

Effects of the Invention As described above, according to the present invention, when braking is performed when the brake pedal is depressed and braking fluid pressure is supplied from the master cylinder to the brake device of each wheel, the system detects the wheel speed based on the wheel speed signal of the wheel speed sensor that detects the wheel speed. The control unit issues a signal to repeat the control pattern of reducing and repressurizing the brake fluid pressure in the brake system of each wheel, thereby ensuring effective braking without locking the wheels. In a skid device, a slope sensor detects whether the road surface is uphill, a torque sensor detects the forward torque acting on the wheels, a reverse switch detects that the transmission has been shifted to the reverse position, etc. Hill holder By equipping the necessary sensor switches and incorporating the information of each sensor switch into the control unit of the anti-skid device, an anti-skid device with a hill holder function can be easily obtained. Various sensors for skid control, braking hydraulic pressure piping, various control valves, etc. can be shared with the hill holder, which can save space and reduce costs, as well as increase the added value of the anti-skid device. This can bring about great practical effects.

[Brief explanation of the drawing]

The attached drawings are explanatory diagrams showing embodiments of the present invention. 1... Brake pedal, 2... Master cylinder, 3
... Main hydraulic pressure system line, 4... Brake device, 5... Third ITjj control valve, 6... First control valve, 7... Sub-hydraulic pressure system line, 8... Second Control valve, 9...Reservoir, 10.
...Electromagnetic pump, 11...Accumulator, 12...
・Relief valve, 13...Control unit, 14
...Wheel speed sensor, 15...Brake pedal switch, 16...Gradient sensor, 17...I/Lux sensor, 18...Reverse switch. that's all

Claims (2)

[Claims] (1) A normally open first control valve that is closed by a hold signal from the control unit is provided in the main hydraulic line that supplies braking hydraulic pressure from the master cylinder to the brake equipment of each wheel, and the main hydraulic line A normally closed second hydraulic pressure line which bypasses the upstream and downstream sides of the first control valve is opened in response to a pressure reduction signal from the control unit and causes the pressure fluid in the brake device to flow into the reservoir.
A control valve and a pump that pumps up the pressure fluid that has flowed into the reservoir and supplies it to the upstream side of the first control valve in the main hydraulic line through the relief valve are provided to control the vehicle body speed when the brake pedal is depressed. The control unit issues a signal in response to a change in wheel speed, operates the first control valve and the second control valve, and repeats a control pattern of reducing and then increasing the hydraulic pressure in the brake device to perform braking. In an automobile anti-skid device configured to perform control, a one-way valve that is open from the master cylinder to the brake system but closed in the opposite direction is connected to the main hydraulic line by a signal from the control unit. A normally open third control valve that switches is provided, and when the road surface is uphill and a braking operation is performed and the vehicle speed reaches a stop or an extremely low speed close to stopping, the control unit switches the third control valve to a one-way valve. The control unit is configured to issue a signal to enter a brake holding state in which the brake fluid pressure of the brake system is maintained even if the foot is released from the brake pedal, and when a predetermined vehicle starting condition occurs in this brake holding state, the control unit An anti-skid device for an automobile, characterized in that the third control valve is configured to open the third control valve and issue a signal to release the brake hold. (2) The third control valve is provided in the main hydraulic line between the master cylinder and the confluence with the sub-hydraulic line on the upstream side of the first control valve, and is provided in the sub-hydraulic line. Claim 1, characterized in that the pump is switched to a one-way valve by a signal from a control unit while the pump is in operation.
Anti-skid device for automobiles as described in Section.