JP2966952B2 - Vehicle braking control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle brake control device for controlling vehicle braking when the pressure of a booster in a brake system decreases.

[0002]

2. Description of the Related Art Conventionally, a vehicle brake system is provided with a booster for doubling the depressing force of a brake pedal and transmitting the force to a wheel brake of each wheel, so that a load in a driver's braking operation is reduced. Has become.

For example, Japanese Patent Application Laid-Open No. 61-36049 discloses a hydraulic pump and a hydraulic accumulator combined with a check valve, and the hydraulic pump supplementarily increases the hydraulic pressure in the apparatus. Shown is a brake pressure generator consisting of a hydraulic power brake booster (double booster) that doubles the brake pedal depression force and a single type master cylinder that supplies the increased brake hydraulic pressure to the wheel brakes of each wheel. ing.

[0004]

In the conventional brake system, for example, the hydraulic pump and the motor for driving the hydraulic pump become abnormal, and the hydraulic pressure is not supplied to the booster. When pressure is no longer maintained,
Sufficient brake fluid pressure is not supplied to the wheel brakes of each wheel, making it difficult to brake the vehicle.

[0005] Even if the supply of the hydraulic pressure to the booster is stopped, the pressure in the booster does not immediately decrease, but the hydraulic pressure gradually decreases due to the brake operation. When the brake operation is performed frequently when the abnormality occurs, the pressure in the booster suddenly decreases, and the safety of the vehicle is significantly reduced.

[0006] This problem is not limited to the above-described hydraulic booster, but also applies to a vacuum booster utilizing an engine intake negative pressure or a negative pressure pump.

The present invention has been made in view of the above problems, and when an abnormal pressure is generated in the booster, the braking force of the driving wheels by the braking means is regulated while the braking by the engine brake is correspondingly restricted. An object of the present invention is to provide a vehicle braking control device capable of effectively utilizing power and suppressing a sudden decrease in pressure in a booster to ensure vehicle safety.

[0008]

According to the present invention, a stepping force of a brake pedal is converted into a brake fluid pressure having an increased stepping force.
And a pressure converting means for outputting, in the brake control apparatus for a vehicle for supplying brake fluid pressure increased the stepping force of the brake pedal to the brake unit of a wheel, adequate blurring
Abnormality that the brake fluid pressure cannot be supplied to the brake means
An abnormality detecting means for detecting that the pressure converting means has occurred.
A step, brake detection means for detecting that the brake pedal is depressed, and the pressure
When abnormality of the force conversion means the brake pedal is depressed in a state that is detected, a brake fluid pressure limitation means for regulating the brake fluid pressure supplied to the braking means of the drive wheel side, by the abnormality detecting means Of the pressure conversion means
The brake pedal is depressed when an error is detected
Engine shake to reduce the driving force of the wheels when
It is obtained by a chromatography key means (claim 1).

Further , the present invention provides a method of producing air at the time of intake of an engine.
The first chamber and the second chamber which are maintained in a negative pressure state by the suction force
With the front by ventilation when the brake pedal is depressed
The pressure in the second chamber is increased to bring the second chamber and the second chamber into contact with each other.
A pressure difference is generated, and the brake pedal is
Boosting means for increasing the stepping force of the
Converts the depressed force of the brake pedal into brake fluid pressure
Conversion means for increasing the depression force of the brake pedal.
Supply increased brake fluid pressure to wheel brake means
In the brake control device for a vehicle, a first chamber and a booster of the booster are provided.
Pressure detecting means for detecting the pressure of the second chamber and the second chamber;
Brake detection hand that detects when the key pedal is depressed
And the pressure detected by the pressure detecting means is set in advance.
When the brake pedal is
When the brake pedal is depressed, the brake
Brake fluid pressure regulating means for regulating the supplied brake fluid pressure
And the pressure detected by the pressure detecting means is set in advance.
The brake pedal is in a state where the value is larger than the reference value.
When depressed, the engine reduces the driving force of the wheels.
Gin brake means (claim 2).

[0010] In the vehicle braking control device,
The brake fluid pressure regulating means is provided for the brake fluid supplied to the brake means.
It is preferable to shut off the rake hydraulic pressure (claim 3).

In the above-mentioned vehicle braking control device,
The engine brake means includes a fuel injection amount, a fuel injection
By controlling the amount of intake
When the engine output is reduced and the driving force of the wheels is reduced,
Good (claims 4-7). Especially in controlling the intake air volume of the engine.
Is equipped with a sub-throttle valve in the intake passage of the engine,
The sub-slot is increased according to the increase in the amount of depression of the brake pedal.
Engine intake by reducing the opening of the throttle valve
It is good to reduce the output of the engine by reducing the amount
(Claim 8).

Further , the present invention provides a vehicle brake control device.
, A torque converter with a lock-up mechanism,
A multi-speed transmission gear mechanism, and the engine braking means comprises:
After performing lock-up of the torque converter,
Shifting down the multi-speed gear mechanism to apply braking force to the wheels
(Claim 9).

[0013] In the vehicle braking control device,
The engine brake means increases the amount of depression of the brake pedal.
Increase the amount of downshifting of the multi-speed gear mechanism according to the size
(Claim 10).

[0014]

According to the first aspect of the present invention, the abnormality detecting means
If sufficient brake fluid pressure is supplied to the pressure
It is detected that an abnormality that can no longer supply
When the brake pedal is depressed in an abnormal state of the force conversion means, the brake fluid pressure supplied to the brake means on the drive wheel side
To regulate one of the braking force of the brake means is reduced
On the other hand, the driving force of the wheels is reduced by the engine braking means.
It is. In other words, if the boost converter becomes abnormal,
The wheels are braked by engine brakes instead of
Will be

According to the second aspect of the present invention, the pressure
First and second chambers of the booster detected by the detector
When the pressure of the battery exceeds a preset reference value,
If the correct brake fluid pressure cannot be supplied to the brake means,
Breaks in the abnormal state of the booster
When the key pedal is depressed, the brake
By regulating the supplied brake fluid pressure,
While braking force is reduced, engine braking means
The driving force of the wheels is reduced.

According to the third aspect of the present invention, the booster
If the brake pedal is depressed during abnormal
Cuts off the brake fluid pressure supplied to the brake means on the driving wheel side
As a result, while the braking force of the brake means is reduced,
The driving force of the wheels is reduced by the gin brake means.

Further , according to the invention of claims 4 to 7,
The brake pedal is depressed when the booster is abnormal
And the brake fluid pressure supplied to the brake means on the drive wheel side
And the braking force of the brake means is reduced.
Method, fuel injection amount, fuel injection timing or engine
The engine output is reduced by controlling the intake air volume
And the driving force of the wheels is reduced by the engine braking means.
It is.

According to the eighth aspect of the present invention, the blur
As the amount of depression of the brake pedal increases, the engine
Reduce the opening of the sub-throttle valve provided in the air passage
By reducing the intake air volume of the engine
Output is reduced.

According to the ninth aspect of the present invention, the booster
If the brake pedal is depressed during abnormal
Regulates the brake fluid pressure supplied to the brake means on the driving wheel side
As a result, the braking force of the brake
Lock-up of torque converter with backup mechanism
Down, the downshift of the multi-speed
Reduces gin output, which reduces wheel drive
Is done .

According to the tenth aspect of the present invention, the brake
Multi-speed gear mechanism according to increase in pedal depression amount
Shift down amount to increase engine output
Thus, the driving force of the wheels is effectively reduced .

[0021]

FIG. 1 shows a vehicle provided with a braking control device according to the present invention. This vehicle includes left and right front wheels 1L and 1R serving as driven wheels and left and right rear wheels 2L and 2R serving as driving wheels. The driving force of an engine 3 is controlled by an automatic transmission 4, a propeller shaft 5, a differential 6, and left and right. Axle 7
It is configured to be transmitted to the rear wheels 2L, 2R via L, 7R. In addition, before disappeared engine 3, well-known of EGI
(Electronically controlled fuel injection device) 23 controls the fuel injection amount and injection timing.

A sub-throttle opening adjustment mechanism 34 is provided in the intake passage 33 of the engine 3, and the output of the engine 3 can be controlled by the sub-throttle opening adjustment mechanism 34. That is, the sub-throttle opening adjustment mechanism 34 includes a sub-throttle valve 37 disposed upstream of a throttle valve 36 that is opened and closed by an accelerator pedal 35, and an actuator 38 that drives the sub-throttle valve 37. The output of the engine 3 is controlled by opening and closing the sub-throttle valve 37 by an actuator 38 in accordance with a control signal output from a control unit UTR described later.

The automatic transmission 4 includes a known torque converter 8 and a multi-stage transmission gear mechanism 9. A combination of excitation and demagnetization of a plurality of solenoids 10 incorporated in a hydraulic circuit of the multi-stage transmission gear mechanism 9. Is changed to change the speed. In addition, the torque converter 8
Has a hydraulically actuated lock-up clutch 11 and switches between excitation and demagnetization of a solenoid 12 incorporated in the hydraulic circuit, whereby engagement and disengagement are performed.

The solenoids 10, 12 are controlled in accordance with a control signal output from a shift control unit 24 (see FIG. 2). The control unit 24 performs predetermined shift control and lockup control based on shift characteristics and lockup characteristics that are set in a known manner, and detection signals output from the throttle opening degree sensor 40 and the vehicle speed sensor 41. A control signal for execution is output to the solenoids 10 and 12.

The front wheels 1L, 1R and the rear wheels 2L,
The 2R is provided with brakes 15a to 15d, respectively, and the calipers 16a to 16d of the brakes 15a to 15d are provided.
Pipes 17a to 17d for supplying brake pressure are connected to d. The pipes 17a and 17b are connected to the booster 19
Discharge port 2 of master cylinder 20 integrally formed with
1a is a branch pipe branched from a pipe 17A at a branch portion G2, and pipes 17c and 17d are pipes 1 connected to a second discharge port 21b of the master cylinder 20.
It is a branch pipe branched from 7B at a branch part G1.

The branch pipes 17c and 17d are provided with electromagnetic on-off valves 29A and 30A, respectively.
A relief passage 31L having an electromagnetic on-off valve 29B and a relief passage 31R having an electromagnetic on-off valve 30B are provided downstream of the installation portion of the on-off valve 30A. In addition, these relief passages 31L, 31R
Is led to the reserve tank 25 of the master cylinder 20, and the brake fluid due to the excess hydraulic pressure is supplied to the reserve tank 2.
5 is returned. And the above-mentioned on-off valve 2
9A, 29B, 30A, 30B constitute braking force control means 32 for the rear wheels 2L, 2R, and include a control unit UT described later.
It is controlled by R.

The pipes 17a and 17b are also provided with relief passages each having an on-off valve having the same structure as described above.

The booster 19 is a well-known vacuum pressure booster. An intake pipe 22 connected to an intake passage 33 of the engine 3 is connected to a front shell of the booster 19, and a negative force is provided in the front shell of the booster 19 by utilizing the suction force of air at the time of intake of the engine 3. Pressure. The depressing force of the brake pedal 18 is increased by the negative pressure in the front shell and transmitted to the master cylinder 20. Further, the pipe 17A, the branch pipe 17a, and the branch pipe 17b pass through the first discharge port 21a of the master cylinder 20. After that, the brake fluid pressure is supplied to the caliper 16a of the left front wheel 1L and the caliper 16b of the right front wheel 1R. Further, the pipe 17B, the branch pipe 17c, and the branch pipe 17d extend from the second discharge port 21b of the master cylinder 20.
, The brake fluid pressure is supplied to the caliper 16c of the left rear wheel 2L and the caliper 16d of the right rear wheel 2R.

The control unit UTR is a control device for controlling the braking force control means 32 to perform slip control and for controlling the braking force of the vehicle when the pressure in the booster 19 becomes abnormal. .

The control unit UTR includes each wheel 1
Wheel speed sensors 39a-39d for detecting the rotational speeds of L, 1R, 2L, 2R, a throttle valve sensor 40 for detecting the opening of the throttle valve 36, and a vehicle speed sensor 4 for detecting the vehicle speed
1. A sub-throttle valve sensor 42 for detecting the opening of the sub-throttle valve 37, a steering angle sensor 43 for detecting the steering angle of the steering wheel, a switch 44 used for manually setting the driving mode and the like, and a depression force of the brake pedal 18. And output signals from a pressure sensor 46 for detecting the pressure in the booster 19.

Next, the control operation of the vehicle brake control device according to the present invention will be described in detail with reference to the block diagram shown in FIG.

The braking control apparatus for a vehicle according to the present invention is designed to operate when the pressure in the booster 19 is not maintained at a normal value due to an abnormality in the intake pipe 22 or the like, and the pressure gradually decreases due to the brake operation. In addition, the safety of traveling of the vehicle is ensured by effectively utilizing the hydraulic brake and the engine brake.

The pressure in the booster 19 is controlled by the control unit UT.
The control unit UTR monitors whether the pressure in the booster 19 is normal by comparing the detected pressure (negative pressure) V from the pressure sensor 46 with a preset reference value Vr. Is determined.

When the detected pressure V becomes larger than the reference value Vr and it is determined that the pressure in the booster 19 is abnormal (pressure drop), the control unit UTR firstly sets
A control signal is sent to the braking force control means 32 to cut the brake fluid pressure supplied to the brakes 15c and 15d of the drive wheels (rear wheels) 2L and 2R, and the pressure in the booster 19 due to the brake operation is sharply increased. Prevent drop. In other words, the braking force control means 32 controls the on-off valves 29A, 3 based on the control signal.
While closing 0A, the on-off valves 29B and 30B are opened to reduce the brake fluid pressure supplied to the brakes 15c and 15d on the drive wheel side (the fluid pressure is reduced to zero).

The closing amounts of the on-off valves 29A and 30A can be changed, and the closing amounts of these on-off valves 29A and 30A are controlled to reduce the amount of brake fluid pressure supplied to the brakes 15c and 15d on the driving wheel side. To control the driving wheels 2L, 2
The braking force of R may be adjusted.

The control unit UTR includes the engine 3
Of the drive wheels 2L,
Perform 2R braking. This is to compensate for the reduction or elimination of the braking force of the drive wheels 2L, 2R by the brakes 15c, 15d with the engine brake. The control of the output of the engine 3 is performed by, for example, controlling the fuel injection amount and the injection timing of the engine 3 and controlling the ventilation amount of the intake passage 33 of the engine 3.

In controlling the fuel injection of the engine 3, a control signal is sent from the control unit UTR to the EGI 23. The EGI 23 receives this control signal and changes the fuel injection amount or injection timing to a preset injection amount or injection timing. As a result, the output of the engine 3 decreases, and a braking force is generated on the drive wheels 2L and 2R.

For controlling the amount of air flow through the engine 3, a drive signal is sent from the control unit UTR to the actuator 38. The actuator 38 reduces the opening of the sub-throttle valve 37 to a preset opening based on the drive signal. As a result, the output of the engine 3 is reduced in the same manner as described above, and a braking force is generated on the drive wheels 2L and 2R.

The output of the engine 3 may be controlled in accordance with the depression force of the brake pedal 18.
In this case, the control unit UTR includes the brake sensor 4
The control data set in advance from the stepping force P of the brake pedal 18 detected by the control unit 5 (control data such as fuel injection amount and injection timing in the former control, and opening of the sub-throttle valve 37 in the latter control) Degree control data)
And sends the calculation result to the EGI 23 or the actuator 38. This calculation may be calculated from a map stored in advance, or may be calculated by a calculation formula.

In the case of the former control, EGI2
3 controls the fuel injection amount or the injection timing based on the input control data to reduce the output of the engine 3 in accordance with the depression force P of the brake pedal 18, and controls the driving wheels 2L,
A predetermined braking force is generated in 2R. In the case of the latter control, the actuator 38 reduces the output of the engine 3 according to the depression force P of the brake pedal 18 by reducing the opening of the sub-throttle valve 37 based on the input control data, and A predetermined braking force is generated on the wheels 2L and 2R.

The braking of the drive wheels 2L and 2R by the engine brake may be performed by controlling the gear ratio of the automatic transmission 4 instead of controlling the output of the engine 3. In this case, a control signal is sent from the control unit UTR to the control unit 24 of the automatic transmission 4. Upon receiving this control signal, the control unit 24 first locks up the torque converter 11, then shifts down the multi-stage transmission gear mechanism 9 to a preset shift to reduce the number of revolutions of the propeller shaft 5, and A braking force is generated on the wheels 2L and 2R. Also in this case, the amount of downshifting can be increased according to the depression force P of the brake pedal 18, and the braking force of the drive wheels 2L and 2R can be varied.

In the case of a rear-wheel drive vehicle, when the driving wheels (rear wheels) 2L and 2R receive a large braking force and the rotation speed thereof is significantly lower than the rotation speeds of the driven wheels (front wheels) 1L and 1R, the vehicle is driven. Running becomes unstable due to skidding at the rear. To avoid this, for example, the front wheel speed sensor 3
The rotation speeds of the front wheels 1L, 1R detected by the wheels 9a, 39b and the rear wheels 2 detected by the wheel speed sensors 39c, 39d.
The running state of the vehicle is determined from the rotation speeds and the difference between L and 2R, and when a state in which running is likely to be unstable (hereinafter referred to as an unstable running area) is confirmed, the braking force by the engine brake is reduced. It is preferable to limit.

In particular, when the braking force by the engine brake is set according to the depression force P of the brake pedal 18,
In consideration of the depression force P of the brake pedal 18, the vehicle speed Vk, and the steering angle θ, the running unstable region is determined. When the running state of the vehicle is in the unstable region, the upper limit value of the braking force by the engine brake is set. Limit to ensure vehicle stability.

In the above embodiment, a so-called master-back type booster has been described. However, the present invention is not limited to this, and can be applied to a hydraulic or pneumatic booster. Further, the present invention can be applied not only to a rear wheel drive vehicle but also to a front wheel drive vehicle and a four wheel drive vehicle.

[0045]

As described above, according to the present invention,
The depression force of the brake pedal is calculated by the pressure conversion means.
The brake fluid pressure is converted to the increased
In the vehicle braking control device that supplies the wheel braking means
And sufficient brake fluid pressure in the pressure conversion means
Brake pedal
When the brake pedal is depressed, the brake fluid pressure
Regulation to reduce braking by the brake means,
Wheel braking by engine brake means
Therefore, even if an abnormality occurs in the brake means, the braking force of the wheels does not suddenly decrease, and the safety of the vehicle is improved.

In particular, the vacuum utilizing the negative pressure of the intake air of the engine
In a braking control system using a pressure booster,
The pressure in the means is greater than a preset reference value
And the brake fluid pressure to the brake means
Pressure in the booster
A sudden decrease in the braking force of the brake means due to the change is prevented.

The fuel injection amount, fuel injection timing
Engine or by controlling the intake volume of the engine
Since the braking force by the brake is controlled,
Even when the brake means is abnormal, the
Brake control of the vehicle wheels, further improving vehicle safety.
You.

Also, in an AT car, after the torque converter is locked up, the multi-speed transmission mechanism is shifted down, and the braking force of the drive wheels is controlled by controlling the number of revolutions to the drive wheels. Thus, the driving wheels can be braked without performing complicated engine output control.

[Brief description of the drawings]

FIG. 1 is an overall system diagram showing an embodiment of a vehicle including a braking control device according to the present invention.

FIG. 2 is a block diagram of a vehicle braking control device according to the present invention.

[Explanation of symbols]

 1L, 1R Driven wheels (front wheels) 2L, 2R Drive wheels (rear wheels) 3 Engine 8 Torque converter 4 Automatic transmission mechanism 9 Multi-speed transmission gear mechanism 11 Lock-up clutches 15a to 15d Brake 18 Brake pedal 19 Booster device 20 Master cylinder 22 Intake pipe 23 EGI (Electronically Controlled Fuel Injection Device) 24, UTR control unit 32 braking force control means 33 intake passage 34 sub-throttle opening adjustment mechanism 37 sub-throttle valve 38 actuator 39a-39d wheel speed sensor 41 vehicle speed sensor 42 sub-throttle valve Sensor 43 Steering angle sensor 45 Brake sensor 46 Pressure sensor

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B60T 17/18 B60T 8/00

Claims (10)

(57) [Claims] (1) The stepping force of a brake pedal is
Pressure conversion means for converting to increased brake fluid pressure and outputting it
The a, the brake control apparatus for a vehicle for supplying brake fluid pressure increased the stepping force of the brake pedal to the brake unit of the wheel, can not be supplied enough brake fluid pressure said brake means
Detecting that an abnormal condition has occurred in the pressure converting means.
Abnormality detection means, brake detection means for detecting that the brake pedal is depressed, and abnormality of the pressure conversion means detected by the abnormality detection means
When depressed the brake pedal and which state is a brake fluid pressure limitation means for regulating the brake fluid pressure supplied to the braking means of the drive wheel side, the abnormality of the pressure conversion means by the abnormality detecting means detection
When the brake pedal is depressed while
Engine braking means for reducing the driving force of the wheel
When braking control apparatus for a vehicle characterized by comprising a. 2. A negative pressure due to an air suction force at the time of intake of the engine.
A first chamber and a second chamber that are maintained in a pressure state;
The air pressure in the second chamber is increased by ventilation when the pedal is depressed.
To generate a pressure difference between the second chamber and the second chamber.
This pressure difference is used to increase the depressing force of the brake pedal.
Greater booster and brake increased by said booster
Conversion means for converting the pedal depression force into brake fluid pressure;
A brake fluid pressure increased the stepping force of the brake pedal
To the vehicle brake control device that supplies the
Oite, pressure detecting the pressure of the first chamber and the second chamber of said booster means
Detecting means for detecting a depression of the brake pedal;
And the pressure detected by the pressure detection means is set in advance.
The brake pedal is depressed when the brake pedal is
When it is inserted, it is supplied to the brake means on the drive wheel side.
Brake fluid pressure regulating means for regulating the brake fluid pressure, and the pressure detected by the pressure detecting means are preset.
The brake pedal is depressed when the brake pedal is
An engine that reduces the driving force of the wheels when plugged in
Brake control apparatus for a vehicle characterized by comprising a braking means. 3. A braking control device for a vehicle according to claim 1 or 2.
Oite the location, the brake fluid pressure limitation means, blanking supplied to the braking means
A brake control device for a vehicle, which cuts off a rake hydraulic pressure . 4. The vehicle braking control device according to claim 1, wherein the engine braking means reduces an output of the engine.
A vehicle braking control device for reducing driving force of wheels . 5. There you <br/> the brake control equipment for a vehicle according to claim 4, wherein the engine braking means controls the injection quantity of the fuel
A braking control device for a vehicle, characterized in that the output of the engine is reduced by the following . 6. The vehicle braking control device according to claim 4,
And Engine brake controls fuel injection timing
To reduce the output of the engine
A braking control device for a vehicle, comprising: 7. The vehicle braking control device according to claim 4, wherein
And The engine braking means controls the intake air amount of the engine
To reduce the output of the engine.
A braking control device for a vehicle, comprising: 8. The vehicle braking control device according to claim 7, wherein
And A sub-throttle valve is provided in the intake passage of the engine, The engine brake means increases the amount of depression of the brake pedal.
It is necessary to reduce the opening of the sub-throttle valve
Reduces the intake air volume of the engine
Braking of vehicles characterized by a reduction in power
Control device. 9. A braking control device for a vehicle according to claim 1,
In place Torque converter with lock-up mechanism and multi-speed gear teeth
Equipped with a car mechanism, The engine brake means is provided for locking the torque converter.
After performing the backup, the shift gear of the
That generate braking force on the wheels
A braking control device for a vehicle, comprising: 10. The braking control device for a vehicle according to claim 9,
And The engine brake means increases the amount of depression of the brake pedal.
Increase the amount of downshifting of the multi-speed gear mechanism according to the size
A braking control device for a vehicle, comprising: