JP2007210482A - Brake device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a BBW type brake device improved in pedal feeling when operating an ABS. <P>SOLUTION: When the ABS is operated in the normal state in which braking force generating means 19F and 19R can be operated, a reaction force admitting valve 30 is closed so that a stroke simulator 25 can not be operated. With this structure, increase of pedal stroke in such a state that braking force is reduced by ABS control can be prevented so as to eliminate uncomfortable feeling of a driver. Since the reaction force admitting valve 30 is closed in timing corresponding to the brake operating state by the driver (stroke speed of a brake pedal 11 and deceleration of a car body) detected by brake operating state detecting means Sd-Sg, the brake pedal 11 can be moved in stroke by the predetermined amount in response to the brake operating state without totally hindering the stroke of the brake pedal 11, and pedal feeling can be thereby improved. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention brakes a wheel by an electric braking force generating means in a normal state, and brakes the wheel with a brake hydraulic pressure generated by a master cylinder by a driver's brake operation at an abnormal time when the braking force generating means becomes inoperable. Relates to the device.

  When the power hydraulic pressure source that generates the brake fluid pressure can be operated normally, the master cylinder cut valve provides communication between the master cylinder that generates the brake fluid pressure and the hydraulic brake that brakes the wheels when the driver depresses the brake pedal. When the hydraulic brake is operated with the brake hydraulic pressure generated by the power hydraulic pressure source and the power hydraulic pressure source becomes inoperable, the master cylinder cut valve is opened to generate the master cylinder. The so-called BBW (brake-by-wire) type that enables the brake pedal stroke by operating the hydraulic brake with the brake hydraulic pressure and absorbing the brake hydraulic pressure generated by the master cylinder with the stroke simulator. This brake device is known from Japanese Patent Application Laid-Open No. H10-228707.

  By the way, when the BBW type brake device is equipped with ABS (anti-lock brake system), if the ABS is activated at the normal time when the hydraulic brake is operated with the brake hydraulic pressure generated by the power hydraulic pressure source, the wheel locks. The brake pedal stroke increases according to the driver's pedaling force due to the action of the stroke simulator, although the braking force generated by the hydraulic brake is reduced to suppress the brake pedal. May feel uncomfortable due to the discrepancy between the actual braking force and the actual braking force.

Therefore, according to Japanese Patent Application No. 2005-295118, when the ABS electronic control unit outputs an ABS operation signal in the BBW brake device, the applicant closes the reaction force permission valve provided between the master cylinder and the stroke simulator. By prohibiting the brake pedal stroke and preventing the pedal stroke from increasing even though the braking force decreases due to ABS control, the discrepancy between the brake pedal stroke and the actual braking force is minimized. To solve the driver's discomfort.
JP 2000-127805 A

  However, as proposed in Japanese Patent Application No. 2005-295118, the reaction force permission valve is closed immediately after the ABS electronic control unit outputs an ABS operation signal regardless of the operating state of the brake pedal by the driver, Since the stroke is prohibited, there is room for improvement in the pedal feeling of the brake pedal.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to improve pedal feeling at the time of operation of an ABS in a BBW brake device.

  In order to achieve the above object, according to the first aspect of the present invention, a master cylinder that generates brake fluid pressure by a driver's brake operation, and a fluid passage that connects the master cylinder and the wheel cylinder are provided. Provided closer to the master cylinder than the pedal force shut-off valve in the fluid path, a pedal force shut-off valve that opens in the event of an abnormality, a braking force generating means that electrically generates a braking force for braking the wheel in response to the driver's brake operation The brake device is equipped with a stroke simulator that absorbs brake fluid from the master cylinder when the pedal force shut-off valve is closed, and a reaction force permission valve that closes when there is an abnormality and shuts off the communication between the stroke simulator and the master cylinder. And a braking operation state detecting means for detecting a braking operation state by the driver, and is adapted to the braking operation state when the ABS is operated. Braking apparatus characterized by closing the reaction force permission valve Te is proposed.

  According to the second aspect of the present invention, in addition to the configuration of the first aspect, the braking operation state by the driver is the brake pedal state until the ABS is activated and the reaction force permission valve is closed. There is proposed a brake device characterized in that the reaction force permission valve is closed so that the stroke speed of the brake pedal becomes smaller as the depression speed becomes higher.

  According to the invention described in claim 3, in addition to the structure of claim 1, the brake pedal stroke increases as the vehicle body deceleration increases when the ABS operates and the reaction force permission valve is closed. Thus, a brake device characterized by closing the reaction force permission valve is proposed.

  According to a fourth aspect of the present invention, in addition to the configuration of the first aspect, after the ABS is activated and the reaction force permission valve is closed, the braking operation state by the driver is vehicle deceleration. A brake device is proposed in which the reaction force permission valve is closed so that the stroke of the brake pedal increases as the vehicle body deceleration increases.

  The wheel speed sensors Sd and Se, the brake light switch Sf, and the pedal stroke sensor Sg according to the embodiment correspond to the braking operation state detection means of the present invention.

  According to the first aspect of the present invention, when the braking force generating means is operating normally, the braking force generating means brakes the wheel while the pedal force cutoff valve is closed and the communication between the master cylinder and the wheel cylinder is blocked. can do. At this time, the reaction force permission valve is opened to allow communication between the master cylinder and the stroke simulator, so that the brake pedal can be stroked while receiving the reaction force to ensure pedal feeling. When the braking force generating means is inoperable, the brake fluid pressure generated by the master cylinder that is activated by the driver's brake operation is set in the state where the pedal force shut-off valve is opened and the master cylinder and the wheel cylinder communicate with each other. The wheel can be braked by supplying it to the cylinder.

  In addition, when the ABS is operated normally, the reaction force permission valve is closed and the stroke simulator is rendered inoperable. Therefore, it is possible to prevent a situation in which the pedal stroke increases while the braking force is reduced by the ABS control, and the driver feels uncomfortable. Can be eliminated. At this time, the reaction force permitting valve is closed according to the braking operation state detected by the driver detected by the braking operation state detecting means, so that the brake pedal can be adjusted according to the braking operation state without disabling the stroke of the brake pedal at all. Therefore, it is possible to make a stroke by a predetermined amount, and the pedal feeling can be improved.

  According to the second aspect of the present invention, when the reaction force permission valve is closed for the first time after the ABS is operated, the reaction force is permitted so that the stroke of the brake pedal becomes smaller as the brake pedal depressing speed increases. Since the valve is closed, the ABS is activated during sudden braking and the braking force actually generated is much smaller than the braking force expected by the driver. The pedal feeling can be improved without feeling.

  Further, according to the configuration of claim 3, the reaction force permission valve is closed so that the stroke of the brake pedal becomes larger as the vehicle body deceleration when the ABS is operated and the reaction force permission valve is closed is larger. Even when the ABS is operating, the brake pedal stroke is generated according to the deceleration of the vehicle body, so that the driver feels uncomfortable and the pedal feeling can be improved.

  According to the fourth aspect of the present invention, after the ABS is activated and the reaction force permission valve is closed, the reaction force is such that the greater the deceleration of the vehicle body caused by the braking operation by the driver, the greater the stroke of the brake pedal. Since the permission valve is closed, the brake pedal can be stroked more easily as the braking force is effectively generated by the ABS, and the pedal feeling can be improved so that the driver does not feel uncomfortable.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  1 to 8 show an embodiment of the present invention. FIG. 1 is a hydraulic system diagram at the time of normal operation of the vehicle brake device, and FIG. 2 is a hydraulic system diagram at the time of abnormality corresponding to FIG. 3 is a flowchart for explaining the action at the start of the ABS operation, FIG. 4 is a flowchart for explaining the action during the ABS operation, FIG. 5 is a map for searching for a pedal permission stroke at the start of the ABS action, and FIG. FIG. 7 is a graph showing the relationship between the pedal stroke and the pedal reaction force according to the operating state of the reaction force permission valve, and FIG. 8 is a time chart for explaining the action when the ABS is operated.

  As shown in FIG. 1, the tandem master cylinder 10 includes first and second output ports 12 a and 12 b that output brake fluid pressure in accordance with a pedaling force that a driver steps on the brake pedal 11. The output port 12a is connected to the disc brake devices 13 and 14 for the left front wheel and the right rear wheel, for example, and the second output port 12b is connected to the disc brake device for the right front wheel and the left rear wheel, for example. In FIG. 1, only one brake system connected to the first output port 12a is shown, and the other brake system connected to the second output port 12b is not shown, but the structure of one and the other brake system is Substantially the same. Hereinafter, one brake system connected to the first output port 12a will be described.

  The first output port 12a of the master cylinder 10 and the wheel cylinder 15 of the disc brake device 13 of the front wheel are connected by liquid passages 17a to 17f, and the liquid passages 17g to 17j branched from the liquid passages 17c and 17d are rear wheels. Are connected to the wheel cylinder 16 of the disc brake device 14.

  A pedal force shut-off valve 18 which is a normally open electromagnetic valve is disposed between the liquid passages 17b and 17c, and a front wheel braking force generating means 19F is disposed between the liquid passages 17d and 17e. The braking force generation means 19F includes a cylinder 20 disposed between the liquid passages 17d and 17e, and a piston 21 slidably fitted into the cylinder 20 is driven by an electric motor 22 via a speed reduction mechanism 23. Thus, the brake fluid pressure can be generated in the fluid chamber 24 formed on the front surface of the piston 21.

  Similarly, a rear wheel braking force generating means 19R is disposed between the liquid passages 17h and 17i. The braking force generating means 19R includes a cylinder 20 disposed between the liquid passages 17h and 17i, and a piston 21 slidably fitted into the cylinder 20 is driven by an electric motor 22 via a speed reduction mechanism 23. Thus, the brake fluid pressure can be generated in the fluid chamber 24 formed on the front surface of the piston 21.

  A stroke simulator 25 connected to the downstream end of the liquid passages 17k to 17n branched from the liquid passages 17a and 17b is a cylinder 26 slidably fitted with a piston 28 biased by a spring 27. A liquid chamber 29 formed on the side opposite to the spring 27 of the piston 28 communicates with the liquid path 17n. A reaction force permission valve 30 that is a normally closed electromagnetic valve is disposed between the liquid passages 17m and 17n. Further, liquid passages 17o and 17p branched from between the liquid passages 17g and 17h communicate with the reservoir 31 of the master cylinder 10, and an atmospheric valve 32 which is a normally closed electromagnetic valve is disposed between the liquid passages 17o and 17p. .

  The BBW electronic control unit (not shown) that controls the operation of the electric motors 22 and 22 of the pedal force cutoff valve 18, the reaction force permission valve 30, the atmospheric valve 32, and the braking force generation means 19F and 19R includes a brake generated by the master cylinder 10. A hydraulic pressure sensor Sa for detecting hydraulic pressure, a hydraulic pressure sensor Sb for detecting brake hydraulic pressure transmitted to the disc brake device 13 for the front wheel, and a brake hydraulic pressure transmitted to the disc brake device 14 for the rear wheel are detected. A hydraulic pressure sensor Sc is connected.

  The ABS electronic control unit U to which the wheel speed of the front wheel detected by the wheel speed sensor Sd and the wheel speed of the rear wheel detected by the wheel speed sensor Se are input is a braking force generating means when the wheel tends to be locked. By controlling the operation of 19F and 19R, the well-known antilock brake control is performed in which the braking force generated by the disc brake devices 13 and 14 for the front wheels and the rear wheels is reduced to suppress the lock of the wheels.

  The signal generating means 33 to which an ABS operation signal from the ABS electronic control unit U and a reaction force permission signal from the BBW electronic control unit (not shown) are inputted is operated to depress the brake pedal 11 to turn on the brake light. A brake light switch Sf for detecting the brake pedal and a pedal stroke sensor Sg for detecting the stroke of the brake pedal 11 are connected to each other, and the signal generating means 33 receives an ABS operation signal, a reaction force permission signal, a signal from the brake light switch Sf, and Based on the signal from the pedal stroke sensor Sg, a signal for opening and closing the reaction force permission valve 30 is output.

  Next, the operation of the embodiment of the present invention having the above configuration will be described.

  In the normal state shown in FIG. 1, the pedal force shut-off valve 18, the reaction force permission valve 30 and the atmospheric valve 32 are energized by a command from a BBW electronic control unit (not shown), the pedal force shut-off valve 18 is closed and the master cylinder 10 is closed. Then, the communication between the disc brake devices 13 and 14 is cut off, the reaction force permission valve 30 is opened, the master cylinder 10 and the stroke simulator 25 are communicated, and the atmospheric valve 32 is opened. In this state, when the driver depresses the brake pedal 11 and the master cylinder 10 generates brake fluid pressure, the fluid pressure sensor Sa detects the brake fluid pressure in the fluid passage 17k closed by the pedal force shut-off valve 18. The BBW electronic control unit operates the braking force generation means 19F and 19R for the front wheels and the rear wheels so as to generate the same hydraulic pressure as the brake hydraulic pressure detected by the hydraulic pressure sensor Sa in the hydraulic passages 17f and 17j.

  As a result, the driving force of the electric motor 22 of the braking force generating means 19F for the front wheels is transmitted to the piston 21 via the speed reduction mechanism 23, and the brake fluid pressure generated in the fluid chamber 24 of the cylinder 20 is transmitted via the fluid passages 17e and 17f. Thus, the front wheel is braked by being transmitted to the wheel cylinder 15 of the disc brake device 13. At this time, the brake fluid pressure in the fluid passage 17f is detected by the fluid pressure sensor Sb, and the operation of the electric motor 22 is fed back so that the brake fluid pressure matches the brake fluid pressure detected by the fluid pressure sensor Sa in the fluid passage 17k. Be controlled.

  Similarly, the driving force of the electric motor 22 of the braking force generating means 19R for the rear wheels is transmitted to the piston 21 via the speed reduction mechanism 23, and the brake fluid pressure generated in the fluid chamber 24 of the cylinder 20 passes through the fluid passages 17i and 17j. To the wheel cylinder 16 of the disc brake device 14 to brake the rear wheel. At this time, the brake fluid pressure in the fluid passage 17j is detected by the fluid pressure sensor Sc, and the operation of the electric motor 22 is fed back so that the brake fluid pressure matches the brake fluid pressure detected by the fluid pressure sensor Sa in the fluid passage 17k. Be controlled.

  When the piston 21 in the cylinder 20 is slightly advanced by the electric motor 22, the communication between the liquid chamber 24 and the liquid path 17d (or the liquid path 17h) is cut off, so that the brake hydraulic pressure generated by the cylinder 20 is reduced. There is no risk of escape to the reservoir 31 via the atmospheric valve 32 provided between 17o and 17p.

  By the way, in the normal state described above, the pedal force shut-off valve 18 is kept closed unless an abnormal state such as a power failure occurs. Conventionally, the brake pads of the disc brake devices 13 and 14 are worn and the cylinders are worn. Even if the volume of the fluid passages 17e and 17f or the fluid passages 17i and 17j between the discs 20 and 20 and the disc brake devices 13 and 14 is increased, the corresponding brake fluid cannot be replenished from the reservoir 31, and the wheel cylinder There is a possibility that a problem that the drag of 15, 16 cannot be reduced occurs.

  However, when the pistons 21 and 21 are retracted in the cylinders 20 and 20, the fluid chambers 24 and 24 communicate with the reservoir 31 through the open air valve 32, and therefore, due to wear of the brake pads of the disc brake devices 13 and 14. Insufficient brake fluid is replenished from the reservoir 31, and dragging of the wheel cylinders 15 and 16 when the braking force is released can be reduced.

  Further, when the driver depresses the brake pedal 11 and the master cylinder 10 generates the brake fluid pressure at the normal time, the brake fluid pressure is transmitted to the fluid chamber 29 of the stroke simulator 25 and the piston 28 resists the elastic force of the spring 27. Thus, a reaction force against the depression of the brake pedal 11 can be generated. As a result, although the disc brake devices 13 and 14 are actually operated by the driving force of the electric motors 22 and 22, the disc brake devices 13 and 14 are operated by the driver's stepping force. The operation feeling can be obtained.

  On the other hand, when the power supply is lost due to battery disconnection or the like, the pedal force shut-off valve 18 is opened as shown in FIG. 2 so that the master cylinder 10 and the disc brake devices 13 and 14 communicate with each other. The valve 30 is closed and communication between the master cylinder 10 and the stroke simulator 25 is cut off. The air valve 32 is closed and communication between the master cylinder 10 and the reservoir 31 is cut off. As a result, the brake fluid pressure generated by the master cylinder 10 when the driver depresses the brake pedal 11 is applied to the wheel cylinder 15 of the disc brake device 13 of the front wheel via the opened pedal force cutoff valve 18 and the braking force generating means 19F. It is transmitted to the wheel cylinder 16 of the disc brake device 14 for the rear wheel via the pedaling force cutoff valve 18 and the braking force generating means 19R that are opened, and the front wheel and the rear wheel are braked.

  At the same time, since the communication between the stroke simulator 25 and the master cylinder 10 is blocked by closing the reaction force permission valve 30, the stroke simulator 25 stops its function. As a result, it is possible to prevent the stroke of the brake pedal 11 from increasing unnecessarily and giving the driver an uncomfortable feeling, and the brake hydraulic pressure generated by the master cylinder 10 is not absorbed by the stroke simulator 25 and the wheel. It is transmitted to the cylinders 15 and 16, and the braking force can be generated with high responsiveness.

  Thus, even if the power supply fails and the pedal force shut-off valve 18, the reaction force permission valve 30, the atmospheric valve 32, and the braking force generating means 19F and 19R become inoperable, the driver steps on the brake pedal 11 to operate the master cylinder. The front and rear wheel cylinders 15 and 16 can be operated without any trouble by the brake fluid pressure generated by the vehicle 10, and thereby the vehicle can be stopped more safely by braking the front and rear wheels in the event of an abnormality.

  By the way, when the wheels tend to lock during normal operation as shown in FIG. 1, the front and rear discs are controlled by controlling the operation of the braking force generators 19F and 19R for the front wheels and the rear wheels according to a command from the ABS electronic control unit U. The well-known antilock brake control for reducing the braking force generated by the brake devices 13 and 14 is executed.

  At this time, assuming that the reaction force permission valve 30 remains open and the stroke simulator 25 is functioning as in the conventional case, the stroke simulator 25 is braked in response to an increase in the pedaling force applied to the brake pedal 11 by the driver. Even if the stroke of the pedal 11 is increased, the deceleration of the vehicle is actually limited to a value corresponding to the road surface friction coefficient by the ABS control, and the driver does not agree with the stroke of the brake pedal 11 and the deceleration of the vehicle. May give a sense of incongruity.

  However, according to the present embodiment, the ABS operation signal output from the ABS electronic control unit U, the vehicle speed signal output from the ABS electronic control unit U, the depression signal of the brake pedal 11 output from the brake light switch Sf, Based on the stroke signal of the brake pedal 11 output from the pedal stroke sensor Sg, the reaction force permission valve 30 is closed at a predetermined timing (see arrow A in FIG. 1), and the stroke simulator 25 stops its function. At this time, since the pedal effort shut-off valve 18 is in a closed state, the brake pedal 11 is restricted in its stroke, a pedal feeling close to that of a recirculating ABS is obtained, and the driver feels uncomfortable. Since the kickback of the brake pedal 11 peculiar to the circulation type ABS does not occur, a sense of security can be given to the pedal feeling during the ABS control.

  This operation will be further described based on the flowcharts of FIGS.

  The flowchart of FIG. 3 shows the operation when the ABS operation is started. First, the driver depresses the brake pedal 11 in step S1, the brake light switch Sf is turned on, and the wheel is locked in step S2. When the ABS is activated, the map shown in FIG. 5 is retrieved in step S3. The map of FIG. 5 searches for the pedal permitted stroke L of the brake pedal 11 using the depression speed of the brake pedal 11 obtained by time differentiation of the stroke of the brake pedal 11 detected by the pedal stroke sensor Sg as a parameter. The pedal permission stroke L of the brake pedal 11 is set so as to decrease as the depression speed increases. When the stroke of the brake pedal 11 detected by the pedal stroke sensor Sg in step S4 becomes equal to or greater than the pedal permission stroke L, the reaction force permission valve 30 is closed in step S5 to disable the stroke simulator 25, thereby The pedal 11 is prevented from being depressed before the pedal permitted stroke L.

  When the brake light switch Sf is turned off without the brake pedal 11 being depressed in step S1, the ABS is not operating in step S2, and the brake pedal 11 detected by the pedal stroke sensor Sg in step S4. When the stroke is less than the pedal permission stroke L, the reaction force permission valve 30 is maintained in the open state in step S6, and the stroke simulator 25 is made operable so that the brake pedal 11 can be depressed.

  As shown by the solid line in FIG. 7, when the ABS is not operating, the pedal reaction force gradually increases as the pedal stroke increases, and when the pedal stroke reaches a predetermined threshold, the pedal reaction force suddenly increases. Yes. On the other hand, when the ABS is activated, when the pedal stroke reaches a relatively small pedal permission stroke L, the reaction force permission valve 30 is closed and the stroke simulator 25 becomes inoperable, thereby rapidly increasing the pedal reaction force. Further, the brake pedal 11 is restrained from being depressed.

  At this time, the pedal permission stroke L searched from the map of FIG. 5 is set so as to decrease as the depression speed of the brake pedal 11 increases. However, the driver feels uncomfortable and the pedal feeling is improved.

  This is because the ABS tends to work harder as the wheels tend to lock more suddenly, so the difference between the braking force that the driver expects and the braking force that is actually generated increases, making it easier for the driver to feel uncomfortable. . At this time, if the brake pedal 11 makes a large stroke, the driver expects a braking force corresponding to the stroke, and the discomfort is further increased. However, in the present embodiment, the pedal permission stroke L of the brake pedal 11 is regulated to be smaller as the brake is suddenly applied. Therefore, the driver feels uncomfortable and the pedal feeling can be enhanced.

  The flowchart of FIG. 4 shows the action during the operation of the ABS. First, the map shown in FIG. 6 is searched in step S11. The map of FIG. 6 searches for the pedal permitted stroke L of the brake pedal 11 using the vehicle body deceleration obtained by time differentiation of the vehicle body speed from the ABS electronic control unit U as a parameter. The pedal permission stroke L of the brake pedal 11 is set so as to increase as the vehicle body deceleration increases. If the stroke of the brake pedal 11 detected by the pedal stroke sensor Sg in step S12 is less than the pedal permission stroke L, the reaction force permission valve 30 is opened in step S13 to enable the stroke simulator 25. The brake pedal 11 moves forward to the pedal permission stroke L. When the stroke becomes equal to or greater than the pedal permission stroke L in step S12, the reaction force permission valve 30 is closed in step S14 to disable the stroke simulator 25, thereby stopping the brake pedal 11 in the pedal permission stroke L. .

  If the pedal permission stroke L searched in step S11 is not greater than or equal to the pedal permission stroke L searched in step S3 of the flowchart of FIG. 3, the reaction force permission valve 30 is maintained in the closed state without opening. The brake pedal 11 remains stopped at the initial pedal permission stroke L when the ABS is operated (that is, the pedal permission stroke L searched in step S3).

  Thus, when a sufficient braking effect is obtained during the operation of the ABS and the vehicle body deceleration increases, the pedal permission stroke L increases as the vehicle body deceleration increases. Therefore, the pedal stroke corresponding to the vehicle body deceleration is increased. Can be obtained. Thereby, the uncomfortable feeling due to the brake pedal 11 being locked so as not to move during the operation of the ABS can be eliminated, and the pedal feeling can be enhanced.

  The time chart of FIG. 8 shows an example of the above-described operation. When the ignition switch is turned on at time t1, the reaction force permission signal is turned from OFF to ON, the reaction force permission valve 30 is opened, and the stroke simulator 25 can be operated. It becomes a state. The driver depresses the brake pedal 11 at time t2, the brake light switch Sf is turned on at time t3, and the ABS is activated at time t4. When the ABS is activated at time t4, the pedal stroke has not yet reached the pedal permission stroke L, so the reaction force permission valve 30 is maintained in the open state.

  When the pedal stroke becomes equal to or greater than the pedal permission stroke L (L1) at time t5, the reaction force permission valve 30 is closed to suppress an increase in the pedal stroke. Even if the ABS stops operating at time t6, the reaction force permission valve 30 is maintained in the closed state, and the pedal permission stroke L (L2) in which the actual pedal stroke is determined according to the increase in vehicle deceleration at time t7. When it becomes less than this, the reaction force permission valve 30 opens. When the ignition switch is turned off at time t8, the reaction force permission signal is also turned off and the reaction force permission valve 30 is closed.

  The embodiments of the present invention have been described above, but various design changes can be made without departing from the scope of the present invention.

  For example, the braking force generators 19F and 19R according to the embodiment generate brake fluid pressure to operate the wheel cylinders 15 and 16, but the wheel cylinders 15 and 16 are operated directly by the driving force of the electric motor 22 without using fluid pressure. 15 and 16 may be operated.

  Further, the vehicle body deceleration when the ABS is activated is detected, and the reaction force permission valve 30 can be closed so that the 11 strokes of the brake pedal become larger as the vehicle body deceleration becomes larger. In this way, it is possible to improve the pedal feeling by generating a pedal stroke corresponding to the vehicle body deceleration even when the ABS is in operation so that the driver does not feel uncomfortable.

Hydraulic system diagram when the brake system for vehicles is normal Hydraulic system diagram at the time of abnormality corresponding to FIG. Flow chart for explaining the action at the start of ABS operation Flow chart explaining the action during ABS operation Map to search for the pedal permitted stroke at the start of ABS operation Map to search for pedal permitted strokes during ABS operation Graph showing the relationship between pedal stroke and pedal reaction force according to the operating state of the reaction force permission valve Time chart explaining the action at the time of ABS operation

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Master cylinder 15 Wheel cylinder 16 Wheel cylinder 17a-17j Fluid path 18 Treading force cutoff valve 19F Braking force generation means 19R Braking force generation means 25 Stroke simulator 30 Reaction force permission valve Sd Wheel speed sensor (braking operation state detection means)
Se wheel speed sensor (braking operation state detection means)
Sf Brake light switch (braking operation state detection means)
Sg Pedal stroke sensor (braking operation state detection means)

Claims (4)

A master cylinder (10) that generates brake fluid pressure by a driver's brake operation;
A pedal force shut-off valve (18) provided in a liquid passage (17a to 17j) connecting the master cylinder (10) and the wheel cylinders (15, 16) and opened in the event of an abnormality;
Braking force generating means (19F, 19R) for electrically generating a braking force for braking the wheel according to the driver's braking operation;
A stroke that is provided closer to the master cylinder (10) than the pedal effort shut-off valve (18) in the fluid passages (17a to 17j) and absorbs brake fluid from the master cylinder (10) when the pedal effort shut-off valve (18) is closed. A simulator (25);
A reaction force permission valve (30) that closes in the event of an abnormality and blocks communication between the stroke simulator (25) and the master cylinder (10);
A brake device comprising:
A braking operation state detection means (Sd, Se, Sf, Sg) for detecting a braking operation state by the driver is provided, and the reaction force permission valve (30) is closed according to the braking operation state when the ABS is operated. Brake device characterized.   Until the ABS is activated and the reaction force permission valve (30) is closed, the braking operation state by the driver is the depression speed of the brake pedal (11), and the brake pedal (11) increases as the depression speed increases. The brake device according to claim 1, characterized in that the reaction force permission valve (30) is closed so that the stroke becomes smaller.   The reaction force permission valve (30) is closed so that the stroke of the brake pedal (11) increases as the deceleration of the vehicle body increases when the reaction force permission valve (30) is closed by the operation of the ABS. The brake device according to claim 1. After the ABS is activated and the reaction force permission valve (30) is closed, the braking operation state by the driver is the vehicle body deceleration, and the greater the vehicle body deceleration, the greater the stroke of the brake pedal (11). The brake device according to claim 1, wherein the reaction force permission valve is closed.

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