JPH10157608A - Brake device for automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely decides on a manipulated variable detecting means trouble by means of a simple structure by comparing a detection result of the manipulated variable detection means for a brake operation member with that of a deceleration detection means of a vehicle when braking force is generated. SOLUTION: A computed brake pedal actuating speed is compared with a predetermined value (stop 201), and it is determined that a stroke sensor is in a normal condition if the actuating speed is more than the predetermined value (step 204). If the actuating speed is the predatermined value of less, on the basis of a relational expression for finding an ideal vehicle deceleration G0 and a brake pedal actuating quantity detected by means of a stroke sensor, and ideal vehicle deceleration G0 corresponding with present actuating quantity is computer (step 202). Subsequently, it is determined whether the vehicle deceleration G is within a lave sera ranging from a value provided by subtracting the predetermined valve A from the ideal vehicle decrelera G0 to a valve provided by adding the predetermined valve B to the ideal vehicle deceleration G0 (step 203). When the vehicle deceleration G is within the area, the stroke sensor is in a normal condition (step 204). When the vehicle deceleration G is out of the area, it is determined that the stroke sensor is in an abnormal condition (step 205).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a braking system for a vehicle, and more particularly to a braking system for a vehicle having an automatic braking process and incorporating a mechanism for monitoring the function of a device for performing the automatic braking process. .

[0002]

2. Description of the Related Art A conventional braking device for a vehicle is disclosed in, for example, Japanese Patent Application Laid-Open No. 07-156789. The vehicle braking device includes a brake operation member, an operation amount detection unit that detects an operation amount accompanying operation of the brake operation member, and a brake light switch that turns on a brake light when the brake operation member is operated. ,
Return operation detection means for detecting a return operation of the brake operation member to the initial position, first determination means for determining whether or not the brake light switch is activated, and whether or not the return operation detection means is activated Second determining means for determining whether or not the operation amount has been detected, first comparing means for comparing the operation amount detected by the operation amount detecting means with a set value, the first determining means, the second determining means, and the first determining means. The apparatus further comprises failure determination means for determining a failure of the operation amount detection means, the brake light switch, and the return operation detection means based on the determination by the comparison means and the comparison result.

When the brake operating member is operated, the brake light switch turns on the brake light in the normal state, and the operation amount detecting means operates in the normal state. An operation amount corresponding to the operation amount is detected, and in the normal state, the return operation detecting means detects the return operation of the brake operation member.

On the other hand, as the brake operating member is operated, the first determining means determines whether or not the brake light switch is operated, and the second determining means activates the return operation detecting means. It is determined whether or not the operation amount and the set value detected by the operation amount detection means by the comparison means, preferably an operation amount of several mm, particularly preferably 5 m
It is determined whether m is greater than m. Based on the first and second determination means, the second determination means, and the comparison means and the determination and comparison result, the failure determination means detects inconsistency in the mutual relationship among the brake light switch, the operation amount detection means, and the return operation detection means. A failure of the brake light switch, the operation amount detection means, or the return operation detection means is determined.

[0005]

However, the conventional automobile brake system detects inconsistency in the interrelationship between the brake light switch, the operation amount detection means and the return operation detection means, and in particular, detects the operation amount detection means. In order to judge the failure, the return operation detecting means is required. That is, in an apparatus having no return operation detecting means, the failure of the operation amount detecting means cannot be determined. Further, since the target set value with which the operation amount is compared by the comparison determination means is an extremely small value of 5 mm, for example, when the actual operation amount of the brake operation member is extremely small, the actual operation amount of the brake operation member When the amount and the value detected by the operation amount detection means match and the actual operation amount of the brake operation member is large, the actual operation amount of the brake operation member and the value detected by the operation amount detection means are different. In a situation where they do not match, a situation may occur in which a failure of the operation amount detecting means cannot be detected.

An object of the present invention is to provide a brake system for a vehicle which has a simple configuration and more reliably determines a failure of an operation amount detecting means.

[0007]

Means for Solving the Problems In order to solve the above technical problem, a brake operating member, a braking force generating means for generating a braking force by operating the brake operating member, An operation amount detection unit configured to detect an operation amount associated with the operation, a deceleration detection unit configured to detect a value related to deceleration of the vehicle when the braking force generation unit generates a braking force; and the operation amount detection unit. A braking device for a vehicle is provided which includes a failure determination unit that compares a detection result with the deceleration detection unit and determines a failure of the operation amount detection unit.

Preferably, there is provided correlation setting means for presetting a correlation between an operation amount of the operation member and a value related to deceleration of the vehicle, and the failure determination means is set by the correlation setting means. It is desirable to provide a vehicle braking device that compares detection results of the operation amount detection means and the deceleration detection means based on the correlation and detects a failure of the operation amount detection means.

Preferably, in the failure detecting means, a value related to deceleration of the vehicle detected by the deceleration detecting means is set by the correlation detecting means of the operation amount detected by the operation amount detecting means. It is preferable that the vehicle braking device detect a failure of the operation amount detection means when the value related to the deceleration of the corresponding vehicle in the correlation is outside a predetermined range.

[0010] Preferably, an operation time detecting means for detecting a time spent for operating the brake operating member, and the brake operating member based on detection results of the operation amount detecting means and the operation time detecting means. Operating speed calculating means for calculating an operating speed associated with the operation, and operating speed comparing means for comparing the operating speed calculated by the operating speed calculating means with a predetermined value. It is desirable that the braking device be operated when the operation speed calculated by the operation speed calculation means is smaller than the predetermined value by the comparison means.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to embodiments.

As shown in FIG. 1, reference numeral 1 denotes a braking device for an automobile, which includes a brake pedal 15, a negative pressure booster 2 and a master cylinder 3 as a fluid pressure generating device, and an ABS (antilock) as a fluid pressure control device. Brake system) 4, stroke sensor 29 as operation amount detection means, wheel speed sensor 31 constituting deceleration detection means, electronic control unit 3
2 is provided.

The vacuum booster 2 will be described in detail. The housing 10 of the negative pressure booster 2 has a movable wall 11 whose outer peripheral portion is hermetically fixed and movable in the axial direction. The inside of the housing 11 is airtightly separated into a constant pressure chamber 12 and a variable pressure chamber 13 by the movable wall 11. The constant-pressure chamber 12 communicates with an intake manifold of a vehicle engine (not shown), which is a negative pressure source, via an inlet 10a, and constantly generates a negative pressure.

A power piston 14 made of a resin material is inserted into the housing 10 from the rear thereof, and the movable wall 11 is fixed to the power piston 14 in an airtight manner at an inner peripheral end thereof.

Inside the power piston 14, an input rod 16 connected to a brake pedal 15 which is a brake operating member of the vehicle at the right end in FIG. 1 is inserted. The input rod 16 is connected to an input member 17 described later so as to be integrally movable.

The input member 17 has a function of transmitting the brake operation force from the input rod 16 to the reaction disk 18. The output rod 19 in contact with the reaction disc 18 receives a brake operation force via the reaction disc 18 and moves, thereby causing the master cylinder 3 to move.
Activate the piston. A first retainer that receives the return spring 20 is fixed to the input rod 16.
A second retainer that supports the right end of the control valve 21 is fixed to the power piston 14 while receiving elastic force from the input rod 16 via the first retainer and the return spring 20. The control valve 21 is engaged with the second retainer at the inner periphery at the right end in the figure, and has a sealing function with the power piston 14 at the outer periphery. A valve spring 22 is interposed between the first retainer and a retainer that supports the seal portion 21a at the left end of the control valve 21. By adopting the above configuration, the seal portion 21a of the control valve 21 is in a state where the input rod 16 is in a non-operating state.
Air valve valve seat 17a formed at the rear end of input member 17
Is engaged. When the input rod 16 is in the operating state, the seal portion 21a can be engaged with the vacuum valve valve seat 14a provided on the power piston 14.

An auxiliary movable wall 23 is installed in the constant pressure chamber 12 as a partition plate which can be engaged with a flange portion of the output rod 19 at an inner peripheral portion thereof. The auxiliary movable wall 23 has an inner peripheral portion and an outer peripheral portion. The airtight engagement with a diaphragm 24 provided with a sealing bead at each portion thereof forms an auxiliary transformation chamber 25 which is an air introduction chamber therebetween. Auxiliary movable wall 2
Numeral 3 is biased by the return spring 26 from the housing 10. An air passage 2 as an elastic air introduction passage airtightly connected at one end to an auxiliary movable wall 23;
Numeral 7 penetrates the constant pressure chamber 12 and hermetically engages an electromagnetic valve 28 described later at the other end. That is, the air passage 27
Is connected to the solenoid valve device 28.

The output rod 19 has a first output rod 191 on the power piston 14 side and a second output rod 191 on the master cylinder 3 side.
And an output rod 192.

FIG. 2 is an enlarged view of the solenoid valve device 28 of FIG. As shown in FIG. 2, an electromagnetic valve device 28 as a switching means for selectively connecting the auxiliary variable pressure chamber 25 of the negative pressure type booster 2 to the constant pressure chamber 12 or the atmosphere is air-tightly disposed on the front surface of the housing 10. Has been established.

The valve housing 28a of the solenoid valve device 28
Is provided therein with a constant-pressure port 28 communicating with the constant-pressure chamber 12.
b, Atmospheric port 28 communicating with air cleaner for air introduction
c, a transformation port 28d connected to the atmosphere passage 27, a constant pressure valve seat 28e communicating the constant pressure chamber 12 with the auxiliary transformation chamber 25, an atmosphere valve seat 28f communicating the atmosphere with the auxiliary transformation chamber 25, and a valve body at the tip. A valve body 28h provided with a certain valve 28g, a movable core 28i, and a movable core 28i at one end (left end) side thereof.
Rod portion 28j that can be brought into contact with
k.

The solenoid 28k is connected to a power supply of a vehicle (not shown) by a terminal 28l, and is operated by being supplied with power from the power supply by a controller of the vehicle (not shown).

In the non-operating state shown in FIG.
8g is disengaged from the constant pressure valve seat 28e,
The auxiliary variable pressure chamber 25 communicates with the constant pressure chamber 12 via the inside of the atmosphere introduction passage 27, the variable pressure port 28d, the gap between the valve 28g and the constant pressure valve seat 28e, and the constant pressure port 28b.

On the other hand, when power is supplied from a power source to the solenoid 28k by the vehicle controller (not shown) as described above, the solenoid 28k suctions the movable core 28i, and the movable core 28i slides rightward in FIG. Therefore, the movable core 28i presses the rod 28j, and the movable core 28i and the rod 28j move integrally to the right in FIG.

The right end of the rod 28j urged by the movable core 28i abuts the left end of the valve 28h, and the rod 28j presses the valve 28h rightward in FIG. The valve 28g contacts the constant pressure valve seat 28e,
In addition, the valve 28g and the atmosphere valve seat 28f are disengaged.

Therefore, the auxiliary transformer chamber 25 is connected to the inside of the atmosphere introduction passage 27, the transformation port 28h, the gap between the valve 28g and the atmosphere valve seat 28f, the communication hole, the atmosphere port 28c, and the atmosphere introduction air cleaner. Atmosphere is introduced from a vehicle interior space (not shown).

The ABS (anti-lock brake system) 4 shown in FIG. 1 has a hydraulic line through which the brake fluid flows, an electromagnetic valve device for blocking the flow of the brake fluid in the hydraulic line, and a brake fluid reservoir. And a pump unit for sucking and discharging the brake fluid.

Normally, the master cylinder 3 and the ABS (anti-lock brake system) 4 act on the brakes via hydraulic pressure in accordance with the output from the output rod 19, so that the speed difference between the vehicle speed and the wheels is large. ABS (anti-lock brake system) is a system that temporarily reduces braking force to prevent wheel slip
Is electrically connected to the electronic control unit 32.

Wheel speed sensors 31a, 31b, 31c for detecting wheel speeds are provided on the wheels FR, FL, RR, RL.
31d are provided respectively. Wheel speed sensor 31
Is also electrically connected to the electronic control unit 32.

The brake pedal 15 is provided with a stroke sensor 29 for detecting the stroke amount of the brake pedal 15, and further provided with a brake switch 30 for turning on a brake light in accordance with the operation of the brake pedal 15. ing. The stroke sensor 29 and the brake switch 30 are each electrically connected to the electronic control unit 32.

The electronic control unit 32, as shown in FIG.
CPU 33, ROM 3 mutually connected via a bus
4, a microcomputer 39 comprising a RAM 35, a timer 36, an input port 37, and an output port 38. The stroke sensor 29, the brake switch 3
0 and the output signals of the wheel speed sensors 31a to 31d are supplied to the input ports 3 via the amplifier circuits 40a to 40f, respectively.
7 to the CPU 33.
Further, the solenoid 28k is output from the output port 38 via a solenoid drive circuit 41 as an automatic braking process control means.
And a braking force control circuit 42
A control signal is output to an ABS (anti-lock brake system) 4 via the control unit. 5 and 6 in the microcomputer 39.
And AB corresponding to each flow chart shown in
A program for controlling S is stored, the CPU 33 executes the program while an ignition switch (not shown) is closed, and the RAM 35 temporarily stores variable data necessary for executing the program.

Next, the operation of the vehicle brake fluid pressure control device 1 according to the present embodiment will be described with reference to FIGS.
FIG. 4 is a characteristic diagram of the negative pressure booster 2 in the present embodiment, in which the vertical axis represents the brake output, and the horizontal axis represents the operating force applied to the brake pedal 15, and FIG. FIG. 6 is a flowchart of an automatic braking process according to an embodiment, and FIG. 6 is a flowchart of stroke sensor failure determination;
FIG. 7 is a correlation diagram between the stroke amount of the brake pedal 15 and the deceleration according to the present embodiment. When the driver operates the brake pedal 15 which is a brake operation member of the vehicle, the input rod 16 connected thereto moves to the left in FIG. 1 by receiving the brake operation force. Therefore, the input member 17 fixed to the input rod 16 also moves to the left in FIG.

When the brake pedal 15 is operated, the brake switch 30 sends an ON signal to the electronic control unit 3.
2 to turn on the brake lights.

By the movement of the input member 17, the control valve 21 and thus the seal portion 21a also move to the left in FIG. 1 together with the input member 17 by the urging force of the valve spring 22, and eventually the seal portion 21a is moved to the vacuum valve valve of the power piston 14. The variable pressure chamber 13 is cut off from the constant pressure chamber 12 by contacting the seat 14a, so that the communication with the negative pressure source of the vehicle is also cut off.

Further, when the input member 17 moves to the left in FIG. 1, the engagement between the seal portion 21a and the air valve valve seat 17a of the input member 17 is released, and the variable pressure chamber 13 communicates with the atmosphere. Accordingly, the atmospheric pressure flows into the variable pressure chamber 13 to generate a pressure difference between the constant pressure chamber 12 and the variable pressure chamber 13, so that the movable wall 11 loaded with the pressure difference and the power piston 14 connected thereto are loaded. Pushes the output rod 19 to the left via the reaction disk 18.

When the output rod 19 is pushed to the left, the power piston 14 outputs the amplified braking force to the output rod 19.

The braking force is output to the output rod 19,
When the output rod 19 is moved to the left in FIG. 1, the piston of the master cylinder 3 is pressed, and the brake fluid
(Anti-lock brake system) Flows out to the wheel cylinder via the wheel 4 and the wheels FR, FL, RR, R of the vehicle
L is given a braking force. That is, in the present embodiment, the negative pressure booster 2, the master cylinder 3, and the ABS
4 constitute a braking force generating means.

In this normal operating state, the solenoid 28k is in the non-operating state, so that the auxiliary variable pressure chamber 25 is in communication with the constant pressure chamber 12, and there is no pressure difference between the front and rear of the auxiliary movable wall 23. Is inactive. The relationship between the brake operating force applied to the brake pedal 15 and the brake output applied to the output rod 19 at this time is shown in FIG.
Is shown in diagram A.

On the other hand, the wheel F is detected by the wheel speed sensor 31.
The wheel speeds of R, FL, RR, and RL are detected, and an ABS (antilock brake system) 4 is driven in accordance with the detection output of the wheel speed sensor 31 to control the brake fluid pressure supplied to the wheel cylinder. Wheels FR, F
The braking force for L, RR, RL is appropriately controlled.

When the depression of the brake pedal 15 is released, the input rod 16 moves toward the outside of the power piston 14, and with the movement of the input rod 16, the valve plunger 17 slides inside the power piston 14, and the air valve valve The seat 17a comes into contact with the seal portion 20a to cut off the communication between the transformation chamber 13 and the atmosphere, and the further movement of the valve plunger 17 causes the seal portion 20a to be pressed and urged by the valve plunger 17, so that the seal portion 20a becomes a vacuum valve It separates from the valve seat 14a, makes the constant pressure chamber 12 and the variable pressure chamber 13 communicate with each other, the atmosphere in the variable pressure chamber 13 flows into the constant pressure chamber 12, and the pressure difference between the constant pressure chamber 12 and the variable pressure chamber 13 disappears, The movable wall 11 and the power piston 14 return to the initial positions. With the return of the power piston 14 to the initial position, the output rod 19 also returns to the initial position, so that the master cylinder 3 lowers the hydraulic pressure and releases the brakes on the wheels FR, FL, RR, RL of the vehicle. In addition, with the return of the brake pedal 15 to the initial position, the brake switch 30
The FF signal is transmitted to the electronic control unit 32 to stop the lighting of the brake light.

Next, the operation of the vehicle brake system 1 in which the failure determination of the stroke sensor 29 and the automatic braking process are performed will be described. When an ignition switch (not shown) is closed, execution of a program corresponding to the flowcharts of FIGS. 5 and 6 is started. When the execution of the program is started, the electronic control unit 32 performs an initial setting and an initial check in steps 101 and 102 and the ABS control program. Thereafter, in step 103, a fixed period (6 ms) checked by the timer 36
Then, the main routine of steps 104 to 111 or 112 is executed. In step 104, the electronic control unit 32 determines whether the stroke sensor 29, the brake switch 3
0, various input data from the wheel speed sensor 31, the timer 41 and the like are taken.

In step 105, the depression amount ST0 of the brake pedal 15 from the stroke sensor 29
(Mm) and one cycle before (6m
s) The depression amount ST of the brake pedal 15 detected in
1 (mm) and the time required for one cycle of the main routine (6 ms), the brake pedal depressing speed V
p0 (mm / sec) is calculated. That is, the brake pedal 1
5 is the depression amount S of the brake pedal 15 from the stroke sensor 29 detected by the depression operation of the pedal 5
One cycle before (6 ms) in the main routine from T0
, The depression amount ST1 of the brake pedal 15 detected at the time is reduced, and the difference between ST0 and ST1 is divided by the time required for one cycle of the main routine, that is, 6 ms.
The brake pedal depression speed Vp0 is calculated.

In step 106, the estimated vehicle speed is calculated based on the wheel speed detected by the wheel speed sensor 31, and subsequently, the change rate Dvso of the estimated vehicle acceleration, that is, the vehicle deceleration G is calculated.

Next, at step 107, a failure judgment of the stroke sensor 29 described later is performed.

In step 108, it is determined whether or not the automatic braking process has been started. If the automatic braking process has been started, the process proceeds to step 109, and if not, the process proceeds to step 110.

In step 110, it is determined whether a condition for starting the automatic braking process is satisfied. In the present embodiment, the brake pedal depressing speed Vp0 calculated in step 105 is compared with a preset threshold value Vpt of the brake pedal depressing speed. If so, the operation of the brake pedal 15 is determined to be a sudden brake operation, and the routine proceeds to step 112; otherwise, the depression of the brake pedal 17 is determined to be a normal brake operation, and No braking process takes place, step 1
Return to 03.

In step 112, a signal is sent to the solenoid drive circuit 41 to drive the solenoid 28k to perform the automatic braking process, so that the solenoid 28
k is driven.

When the solenoid 28k is driven, the movable core 28k resists the urging force of the spring.
Is moved to the right.

As described above, since the atmosphere is introduced into the auxiliary transformation chamber 25 by the movement of the movable core 28k, a pressure difference occurs before and after the auxiliary movable wall 23, and the auxiliary movable wall 2
3 is moved to the left in FIG.

As the auxiliary movable wall 23 moves,
The second output rod 192 is provided on the inner peripheral portion of the auxiliary movable wall 23.
Of the second output rod 19
1 is moved by applying a load leftward in FIG.

Since the load applied to the second output rod 192 does not act on the reaction disk 18, it does not become a reaction force to the input member 17, but is purely increased as a brake output.

The movement of the second output rod 192 increases the hydraulic pressure of the master cylinder 3, and causes the wheels FR, FR of the vehicle to pass through an ABS (anti-antilock brake system) 4.
Apply brakes to FL, RR and RL. A if necessary
The operation of the BS (anti-antilock brake system) 4 is performed.

By introducing the atmosphere into the auxiliary transformer chamber 25, the brake output acting on the output rod 19 is increased by a certain amount for the same brake operating force acting on the brake pedal 15 as compared to when the pressure in the auxiliary transformer chamber 25 is negative. . The relationship between the brake operation force applied to the brake pedal 15 and the brake output applied to the output rod 19 at this time is shown by a diagram B in FIG. That is, an automatic braking process is performed that automatically establishes a higher braking pressure resulting from the brake pedal position.

When the automatic braking process is performed, step 11
2 to step 103, and steps 104, 10
Proceed to step 108 via 5, 106, 107,
In step 108, since the automatic braking process is being performed, the process proceeds to step 109.

In step 109, it is determined whether an automatic braking process end condition has been satisfied. In the present embodiment, it is determined whether or not the brake switch 30 is transmitting an OFF signal to the electronic control unit 32. If the brake switch 30 is transmitting the OFF signal, step 1 is performed.
Proceed to step 11; otherwise, return to step 103.

That is, when the depression of the brake pedal 15 is released, the input rod 16 moves toward the outside of the power piston 14, and the input member 17 moves rightward integrally with the input rod 16 by retreating the input rod 16. Go to
The seal member 21a of the control valve 21 is the input member 1
7 and the sealing portion 21a is separated from the valve seat 14a of the power piston 14, so that the variable pressure chamber 13 is cut off from the atmosphere, communicates with the constant pressure chamber 12, and the degree of negative pressure in the variable pressure chamber 13 increases again. The assisting force to the power piston 14 also decreases, and the power piston 14 and the input rod 16 are moved rightward in FIG. 1 by the reaction force from the master cylinder 3 and the return spring 26 in the booster. Complete the process. On the other hand, with the return of the brake pedal 15 to the initial position, the brake switch 29
The FF signal is transmitted to the electronic control unit 32.

In step 109, the electronic control unit 3
2 receives the OFF signal of the brake switch 30,
The drive of the solenoid 28k is released, and the automatic braking process ends. That is, since the driving of the solenoid 28k is released, the solenoid 28k no longer generates an electromagnetic force to the movable core 28i, and the movable core 28i is moved leftward in FIG. 2 by the urging force of the spring via the rod 28j. Is returned to. In addition, the valve body 28h is urged leftward in FIG. 2 by the urging force of the spring, so that the valve 28g is separated from the constant-pressure valve seat 28e and comes into contact with the atmospheric valve seat 28f.

By moving the movable core 28i and the valve body 28h to the left in FIG. 2, the auxiliary variable pressure chamber 25 is isolated from the atmosphere and communicates again with the constant pressure chamber 12, and the auxiliary movable wall 23 is initialized by the return spring 26. Pushed back toward the position, the engagement between the inner peripheral portion of the auxiliary movable wall 23 and the flange portion of the second output rod 192 is released, and the initial state is completely restored. By returning the second output rod 192 to the initial position,
The master cylinder 3 lowers the hydraulic pressure, and the wheels FR, F of the vehicle
Release the brakes of L, RR and RL. That is, the automatic braking process ends.

The failure determination of the stroke sensor 29 in step 107 is performed by executing the flowchart shown in FIG.

First, in step 201, the brake pedal depressing speed Vp0 calculated in step 105 is compared with a predetermined value, for example, 50 mm / sec. If the stepping speed Vp0 is 50 mm / sec or less, the process proceeds to step 202;
Proceeding to 04, it is determined that the stroke sensor 29 is normal.

Next, at step 202, a relational expression for obtaining an ideal vehicle deceleration G0 with respect to a preset depression stroke of the brake pedal 15 shown as a correlation characteristic line a in FIG. 7 is called. Based on this relational expression and the depression amount ST0 of the brake pedal 15 detected by the stroke sensor 29, an ideal vehicle deceleration G0 corresponding to the current depression amount ST0 is calculated.

In step 203, step 106
Is the value obtained by subtracting the predetermined value A from the ideal vehicle deceleration G0 calculated in step 202 and the value obtained by adding the predetermined value B to the ideal vehicle deceleration G0 calculated in step 202. It is determined whether or not it is within the range. In step 203, if the vehicle deceleration G is within this range, in step 204, it is determined that the stroke sensor 29 is normal.

In step 203, if the vehicle deceleration G is not within this range, in step 205, the stroke sensor 29 cannot detect a correct stroke amount, that is, it is determined that the stroke sensor 29 is abnormal. The operation of the automatic braking process is prohibited, and the driver is notified of the failure of the stroke sensor 29 by a warning display and a warning sound. As described above, according to the vehicle braking device 1 of the present embodiment, a substantially one-to-one relationship is established between the stroke amount of the brake pedal 15 and the pressure of the master cylinder 3 generated when the brake pedal 15 is depressed. In addition, since the pressure of the master cylinder 3 and the deceleration G of the vehicle also have an integral relationship,
Focusing on the fact that an integral relationship is established between the stroke amount of the brake pedal 15 and the deceleration G of the vehicle, the stroke amount of the brake pedal 15 and the vehicle deceleration G
By comparing with the above, a failure of the stroke sensor 30 can be detected.

Further, A generally having a wheel speed sensor
By combining the present invention with an automobile braking device having a BS (anti-skid control system), a simpler configuration can be achieved. Also, with this combination, regarding the failure determination of the wheel speed sensor,
Since it can be performed by the ABS control program,
A simpler configuration can be achieved.

Further, the failure of the stroke sensor 30 can be determined without the need for the return operation detecting means required in the conventional automobile braking device.

Further, the failure of the stroke sensor 30 can be determined in any range of the stroke amount, so that the abnormality of the stroke sensor 30 can be reliably detected.

Further, by setting in advance a regression equation for obtaining an ideal vehicle deceleration G according to the stroke amount of the brake pedal 15, the stroke amount detected by the stroke sensor 30 based on this regression equation is calculated. By finding the ideal vehicle deceleration G0 and comparing the ideal vehicle deceleration G0 with the detected vehicle deceleration G, it is possible to determine the failure of the stroke sensor 30 more easily and reliably.

Further, the ideal vehicle deceleration G0 is corrected by the predetermined values A and B, and the calculated vehicle deceleration G is obtained by calculating the ideal vehicle deceleration G0−the predetermined value A and the ideal vehicle deceleration G0 + the predetermined value B. Since the failure of the stroke sensor 29 is determined based on whether or not the stroke sensor 29 exists within the range, the calculation error of the vehicle deceleration G can be allowed.

Further, when the stepping speed Vp0 of the brake pedal 15 is high, the pressure increase of the master cylinder 3 cannot follow the stepping of the brake pedal 15, and there is a possibility that the stepping amount Sp0 and the vehicle deceleration G are shifted. . However, when the brake pedal 15 is depressed and the depression speed Vp0 is equal to or less than the predetermined value 50 mm / sec, that is, when the operation of the brake pedal 15 becomes slow, the depression amount Sp0 is compared with the vehicle deceleration G. Therefore, there is no deviation between the depression amount Sp0 and the vehicle deceleration G, and it is possible to reliably determine the failure of the stroke sensor 30.

Therefore, it is possible to provide a vehicle braking device which has a simple configuration and more reliably determines the failure of the operation amount detecting means.

In this embodiment, the sensor 3 for detecting the amount of depression of the brake pedal 15 directly from the brake pedal 15 is used for detecting the amount of depression of the brake pedal 15.
Although 0 is used, it goes without saying that the present invention is not particularly limited to this configuration. In the present embodiment, the automatic braking process is performed by supplying a power to the solenoid 28k in the negative pressure type booster 2 to drive the solenoid 28k to activate the boosting action. The pressure is automatically established. For example, an ABS (anti-hydraulic control device) including a pump unit capable of independently applying hydraulic pressure to each wheel cylinder of the wheels FR, FL, RR, and RL is used. The present invention relates to a vehicle braking system according to the present invention in which a braking force is applied to wheels by operating this pump unit using a lock brake system, thereby automatically establishing a larger braking pressure resulting from a brake pedal position. Similar effects can be obtained in the device. In the present embodiment, the braking force generating means includes the negative pressure type booster 2, the master cylinder 3, and the ABS (anti-skid control system) 4, but is particularly limited to this configuration. Needless to say, the configuration of the negative pressure booster 2 is not limited to the above configuration.

In the present embodiment, step 1
Although the processing of 04 or less is performed every 6 ms, it is needless to say that the present invention is not particularly limited to this configuration.

Further, in this embodiment, the vehicle deceleration G is used as a value relating to the deceleration of the vehicle, and the vehicle deceleration G is compared with the brake pedal depression amount ST0. However, the present invention is not particularly limited to this. Instead, for example, as described above, the same operation and effect can be obtained in the automotive braking system of the present invention in which the master cylinder pressure is used as a value related to the deceleration of the vehicle and the master cylinder pressure is compared with the brake pedal depression amount ST0. .

Further, in this embodiment, when the stepping speed Vp0 is equal to or less than a predetermined value of 50 mm / sec, the stepping amount Sp0 is compared with the vehicle deceleration G. However, the present invention is particularly limited to this structure. It goes without saying that it is not.

In the present embodiment, the depression amount ST of the brake pedal 15 from the stroke sensor 29 is set.
0 (mm) and one cycle before (6m
s) The depression amount ST of the brake pedal 15 detected in
1 (mm) and the time required for one cycle of the main routine (6 ms), the brake pedal depressing speed V
Although p0 (mm / sec) is calculated, it is needless to say that the configuration is not limited to a specific configuration.

Although the present invention has been described with reference to the above embodiment, the present invention is not limited to the above embodiment but includes various embodiments according to the principle of the present invention.

[0076]

As described above, according to the first aspect of the present invention, the failure of the operation amount detecting means is detected by comparing the operation amount of the brake operating member with a value related to the deceleration of the vehicle. It is possible. Further, it is possible to determine the failure of the operation amount detecting means without the need for the return operation detecting means required in the conventional automobile braking device.

Further, it is possible to perform a failure judgment of the operation amount detecting means in any operation amount region.
It is possible to reliably detect a failure of the operation amount detection means.

Therefore, it is possible to provide a vehicle braking device which has a simple configuration and more reliably determines the failure of the operation amount detecting means.

According to the second aspect of the invention, in addition to the effect of the first aspect, the correlation between the operation amount of the brake operation member and the value related to the deceleration of the vehicle is set in advance, This makes it possible to more easily and reliably determine the failure of the operation amount detection unit.

According to the third aspect of the invention, in addition to the effect of the second aspect of the invention, an error in the value relating to the deceleration of the vehicle can be allowed, and the failure of the operation amount detecting means can be more reliably determined. Is possible.

According to the fourth aspect of the present invention, in addition to the effects of any one of the first to third aspects of the present invention, when the stepping speed of the brake operating member is high, it is related to the stepping amount and the deceleration of the vehicle. There is a risk of deviation from the value. However, when the depressing speed of the brake operating member is equal to or less than the predetermined value, since the depressed amount is compared with the value related to the deceleration of the vehicle, there is no deviation between the depressed amount and the value related to the deceleration of the vehicle. This makes it possible to reliably determine the failure of the operation amount detecting means.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a vehicle braking device 1 according to the present embodiment.

FIG. 2 is a partially enlarged sectional view of the negative pressure type booster 2 of FIG.

FIG. 3 is a block diagram showing a configuration of an electronic control device 32 of FIG. 1;

FIG. 4 is a characteristic diagram of the vacuum booster 2 of the present embodiment.

FIG. 5 is a flowchart of an automatic braking process according to the embodiment.

FIG. 6 is a flowchart of stroke sensor failure determination according to the embodiment.

FIG. 7 is a regression diagram relating to the amount of depression of the brake pedal and the deceleration of the vehicle according to the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Brake apparatus for vehicles 2 Negative pressure booster 3 Master cylinder 4 ABS 15 Brake pedal 30 Stroke sensor 31 Wheel speed sensor 32 Electronic control unit

Claims (4)

[Claims] A brake operation member, a braking force generating means for generating a braking force when the brake operation member is operated, an operation amount detection means for detecting an operation amount accompanying operation of the brake operation member, When the braking force generating means generates a braking force, deceleration detecting means for detecting a value related to deceleration of the vehicle, and comparing detection results of the operation amount detecting means and the deceleration detecting means, A braking device for a vehicle, comprising: a failure determination unit that determines a failure of the operation amount detection unit. 2. The apparatus according to claim 1, further comprising: a correlation setting unit configured to preset a correlation between an operation amount of the operation member and a value related to deceleration of the vehicle, wherein the failure determination unit is set by the correlation setting unit. 2. The vehicle braking device according to claim 1, wherein a detection result of the operation amount detection unit and a detection result of the deceleration detection unit are compared based on the correlation to detect a failure of the operation amount detection unit. 3. The failure detection means, wherein a value related to deceleration of the vehicle detected by the deceleration detection means is set by the correlation detection means of an operation amount detected by the operation amount detection means. When a value related to deceleration of the corresponding vehicle in the correlation is outside a predetermined range,
3. The automobile braking device according to claim 2, wherein a failure of said operation amount detection means is detected. 4. An operation time detecting means for detecting a time spent for operating the brake operating member, and the brake operation member is controlled based on detection results of the operation amount detecting means and the operation time detecting means. Operating speed calculating means for calculating an operating speed associated with the operation; operating speed comparing means for comparing the operating speed calculated by the operating speed calculating means with a predetermined value; And actuated when the operation speed calculated by said operation speed calculation means is equal to or less than said predetermined value.
The vehicle braking device according to any one of claims 1 to 3.