JP2000108859A - Brake controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely release an automatic braking state when a brake pedal is operated during automatic braking. SOLUTION: This braking controller is provided with a master cylinder 1, liquid pressure sources 3 and 4, a control valve 10 disposed on a liquid pressure transmission path, a valve control means for controlling the control valve 10, a traveling state detecting means, an automatic braking means for automatically braking a vehicle by transmitting liquid pressures accumulated in the liquid pressure sources 3 and 4 to a wheel cylinder 1 based on the detecting result of the traveling state detecting means, and a brake operation detecting means 6. The valve control means communicates the wheel cylinder 1 of a specified wheel with the master cylinder 1 during automatic braking by the automatic braking means, comminicates the wheel cylinder 1 of a wheel other than the specified one with the liquid pressure sources 3 and 4, and the automatic braking means releases the automatic braking state is released when the operation of a brake pedal 5 is detected by the brake operation detecting means 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a brake control device for automatically braking a vehicle.

[0002]

2. Description of the Related Art As a brake control device for automatically braking a vehicle, one disclosed in Japanese Patent Application Laid-Open No. 9-11870 is known. The control device described in Japanese Patent Application Laid-Open No. 9-11870 detects a preceding vehicle or an obstacle in front of the vehicle, and if a collision is predicted, automatically brakes the vehicle, thereby realizing inter-vehicle distance securing and collision avoidance. Things.

[0003]

In the control device for performing the above-described automatic braking, there is a case where it is desired to perform a process for releasing the automatic braking when the brake pedal is operated during the automatic braking. Therefore, there is a demand for a brake control device that performs automatic braking and that can reliably detect when a brake pedal is operated.

Accordingly, it is an object of the present invention to provide a brake control device capable of reliably releasing an automatic braking state when a brake pedal is operated during automatic braking.

[0005]

According to a first aspect of the present invention, there is provided a master cylinder for generating a hydraulic pressure according to an operation force of a brake pedal, a hydraulic pressure source for generating a predetermined hydraulic pressure and accumulating the hydraulic pressure, A plurality of control valves disposed on a plurality of hydraulic pressure transmission paths for transmitting hydraulic pressure from a master cylinder or a hydraulic pressure source to a wheel cylinder, and valve control means for controlling the control valve;
Traveling state detection means for detecting the traveling state of the vehicle, automatic braking means for transmitting the hydraulic pressure accumulated in the hydraulic pressure source to the wheel cylinder based on the detection result of the traveling state detection means to automatically brake the vehicle, and brakes A brake control device comprising: brake operation detection means for detecting that a pedal has been operated, wherein the valve control means communicates a wheel cylinder of a predetermined wheel with a master cylinder during automatic braking by automatic braking means, A wheel cylinder of a wheel other than the predetermined wheel is communicated with the hydraulic pressure source, and the automatic braking state is released when the automatic brake means detects a brake pedal operation by the brake operation detecting means.

According to the first aspect of the invention, during automatic braking, a wheel cylinder of a predetermined wheel is communicated with the master cylinder, and wheel cylinders of wheels other than the predetermined wheel are communicated with the hydraulic pressure source. . For this reason, when the brake pedal is operated during automatic braking, the hydraulic pressure in the master cylinder is transmitted to the wheel cylinder of the predetermined wheel, and the brake pedal strokes with a sufficient stroke amount. The operation of the brake pedal can be reliably detected by the stroke having the sufficient stroke amount, and the automatic braking state can be reliably and promptly released based on the detection of the operation of the brake pedal.

According to a second aspect of the present invention, in the first aspect, the traveling state detecting means has an object detecting function of detecting an object in front of the vehicle.

According to the second aspect of the present invention, automatic braking can be performed when an object ahead of the vehicle is detected by the traveling state detecting means. At this time, if the braking state under the automatic braking state is different from the braking state intended by the driver due to the relationship with the object ahead of the vehicle, the driver operates the brake pedal and operates the brake pedal. By this natural driving action, the automatic braking state can be reliably and promptly released.

The invention described in claim 3 is the first or second invention.
The brake operation detecting means is a switch for detecting that the stroke amount of the brake pedal has become equal to or greater than a predetermined value.

According to the third aspect of the present invention, the switch for detecting that the stroke amount of the brake pedal has exceeded a predetermined value is used for detecting that the brake pedal has been operated. In detecting the operation, a special mechanism or the like is not required, and the operation of the brake pedal can be reliably and easily detected.

According to a fourth aspect of the present invention, in the first aspect of the present invention, the predetermined wheel is a front wheel.

According to the fourth aspect of the present invention, even if the mechanism for transmitting the hydraulic pressure of the hydraulic pressure source breaks down, the brake pedal operating force is transmitted to the front wheels via the master cylinder during automatic braking. The vehicle can be braked by the operation pedaling force. At this time, since it is the front wheel cylinder that is in communication with the master cylinder, effective braking can be performed by performing braking with the front wheels whose contact load increases.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a brake control device according to the present invention will be described with reference to the drawings.

The brake control device according to the present embodiment is capable of detecting a preceding vehicle and automatically braking the vehicle in order to maintain a constant inter-vehicle distance. It is also possible to perform emergency automatic braking for collision avoidance. Further, the brake control device according to the present embodiment has a so-called AB
The vehicle can be braked during S, traction control (TRC), and vehicle stability control (VSC).

As shown in FIG. 1, the brake control device of the present embodiment employs a so-called hydro booster actuator system. The hydraulic pressure required during braking (in the present embodiment, brake oil is used as the brake fluid, and hence also referred to as hydraulic pressure), a master cylinder / brake booster (hereinafter simply referred to as master cylinder) 1 and a hydraulic pressure source Is generated by the pump motor 3 and the accumulator 4.

The hydraulic pressure generated by the master cylinder 1 and the hydraulic pressure accumulated in the accumulator 4 are transmitted to the wheel cylinders 11 of the respective wheels via a brake pipe, which is a hydraulic pressure transmission path, using brake oil as a medium. Brake oil filled in the brake pipe is stored in the reservoir tank 2. A plurality of control valves 10 are arranged on the brake pipe to switch hydraulic pressure transmission paths and control hydraulic pressure transmitted to the wheel cylinders 11.

Hereinafter, each component described above will be described in detail.

The master cylinder 1 is integrally formed with a brake booster for boosting the driver's operation force on the brake pedal 5, and is filled with brake oil via a pipe from the reservoir tank 2. I have.

An operating rod 1a connected to the brake pedal 5, a power piston 1b connected to the operating rod 1a, and an abutment with the power piston 1b are provided inside the master cylinder 1 on the vehicle cabin side. A master cylinder piston 1c is slidably disposed. Operating rod 1a
When the brake pedal 5 is depressed, the power piston 1b and the master cylinder piston 1c integrally slide to the left in FIG.

Further, inside the other end side of the master cylinder 1, a regulator piston 1f connected to the master cylinder piston 1c via a first return spring 1d and a connecting rod 1e, and connected to the regulator piston 1f. A spool valve 1g is slidably disposed. Although the regulator piston 1f and the spool valve 1g slide together,
The second return spring 1h is constantly biased rightward in FIG.

A master cylinder chamber 1i is formed between the master cylinder piston 1c and the regulator piston 1f. Normally, the pressure in the master cylinder chamber 1i is transmitted to the front wheel cylinder 11. A regulator chamber 1j is formed on the side of the regulator piston 1f opposite to the master cylinder chamber 1i. Usually, the pressure in the regulator chamber 1j is equal to the power piston 1b.
Is transmitted to the wheel cylinder 11 of the rear wheel via a booster room 1k formed on the vehicle cabin side of the vehicle. That is, normally, the hydraulic pressure of the accumulator 4 is controlled by the regulator chamber 1j.
After being adjusted by the regulator section from the pressure regulator to the booster chamber 1k, the pressure is transmitted to the wheel cylinder 11 of the rear wheel.

The spool valve 1g switches between communication between the regulator chamber 1j with the reservoir tank 2 and communication with the accumulator 4 depending on the slide position. The spring constant of the first return spring 1d is larger than the spring constant of the second return spring 1h, and when the brake pedal 5 is depressed, the spring is first contracted from the second return spring 1h. A master cylinder pressure sensor 7 for detecting the oil pressure from the regulator chamber 1j to the booster chamber 1k is provided on the brake pipe from the booster chamber 1k.

The brake pedal 5 is connected to a stop lamp switch 6 which is a brake operation detecting means for detecting that the brake pedal 5 is operated. The stop lamp switch 6 is connected to the brake pedal 5
When the stroke amount becomes equal to or more than a predetermined value, it functions as a switch for turning on a stop lamp attached to the rear of the vehicle and sends a predetermined signal to an electronic control unit (ECU) 13 (see FIG. 2) described later. Has a function.

The pump motor 3 constituting the hydraulic pressure source has an ECU
In accordance with a command from the controller 13, the brake oil that is driven by the electric power of the battery and stored in the reservoir tank 2 is sent to the accumulator 4. An accumulator 4, another component of the hydraulic source, stores brake oil delivered by the pump motor 3 therein under high pressure.

A pressure switch 8 and a relief valve 9 are provided on a brake pipe from the accumulator 4. The pressure switch 8 is constituted by a pair of two. One pressure switch PH outputs a PH low pressure signal to the ECU 13 when the oil pressure on the brake pipe becomes equal to or lower than a predetermined lower limit pressure (here, about 15 MPa). When a predetermined upper limit pressure (here, about 16.1 MPa) is reached, a PH high pressure signal is sent to the ECU 13. The ECU 13 drives the pump motor 3 to increase the oil pressure in the accumulator 4 when receiving the PH low pressure signal, and stops the pump motor 3 when receiving the PH high pressure signal, and constantly controls the pressure in the accumulator 4. It is maintained within a predetermined range.

The other pressure switch PL sends a PL low pressure signal to the ECU 13 when the oil pressure on the brake pipe becomes equal to or lower than a predetermined lower limit pressure (here, about 10.8 MPa), and outputs a predetermined upper limit pressure (here, About 11.9MPa)
An L high voltage signal is sent to the ECU 13. When receiving the PL low pressure signal, the ECU 13 turns on the brake warning lamp and sounds the buzzer to alert the driver, assuming that the hydraulic pressure source is not operating normally.

When the hydraulic pressure of the hydraulic pressure source becomes extremely high (here, about 24 MPa) due to a failure of the pressure switch 8 or the like, the relief valve 9 is opened by the hydraulic pressure. As a result, the brake oil on the accumulator 4 side is returned to the reservoir tank 2 side, and an excessive pressure increase in the brake pipe is prevented.

The brake pipe serving as the hydraulic pressure transmission path is shown in FIG.
The transmission path is switched and the wheel cylinder 1 is arranged on the brake pipe.
A plurality of control valves 10 for adjusting the hydraulic pressure transmitted to
Are arranged. The state shown in FIG. 1 is a state where all the control valves 10 are turned off. In the present embodiment, the control valve 10 is constituted by a solenoid valve. However, any mechanism may be used as long as it can switch the transmission path of the brake oil and adjust the hydraulic pressure to be transmitted. In the following description, each control valve 10 is distinguished by a symbol attached to each control valve 10 in FIG.

The brake pipe from the master cylinder chamber 1i is branched into two, and control valves SA1 and SA2 are respectively disposed on the brake pipe. Brake pipes from control valves SA1 and SA2 to each front wheel are provided.
Are connected to the wheel cylinders 11 of the respective front wheels via control valves SFRH and SFLH, respectively. Control valves SA1 and SA2 are
The hydraulic pressure transmitted to the front wheel cylinder 11 is switched between the hydraulic pressure from the master cylinder chamber 1i, the hydraulic pressure from the accumulator 4, and the hydraulic pressure from the regulator unit. Here, accumulator 4
When the hydraulic pressure from the controller and the hydraulic pressure from the regulator unit are transmitted, in addition to the switching of the control valves SA1 and SA2, the switching of the control valve STR and the control valve SA3 is also performed.

Control valves SFRH, SFLH and wheel cylinder 11
The brake pipes are further branched from between and the control valves SFRR and SFLR are provided respectively. Control valves SFRR and SFLR are
It communicates with the reservoir tank 2. These control valves SFR
H, SFLH, SFRR, SFLR, pressure increase mode for increasing the oil pressure in the wheel cylinder 11, holding mode for holding the oil pressure in the wheel cylinder 11, wheel cylinder 11
Switch the pressure reduction mode to reduce the oil pressure in the inside.

Each of the above-described modes will be described using the right front wheel as an example. The pressure increasing mode is a state in which the hydraulic pressure is transmitted to each wheel cylinder 11 to increase the hydraulic pressure in the wheel cylinder 11 when both the control valves SFRH and SFRR are off. The holding mode is a state where the brake valve to the wheel cylinder 11 is completely shut off and the oil pressure in the wheel cylinder 11 is held while the control valve SFRH is on. The pressure reduction mode is a state where the wheel cylinder 11 is communicated with the reservoir tank 2 to reduce the oil pressure in the wheel cylinder 11 when both the control valves SFRH and SFRR are on.
The same applies to the left front wheel.

On the other hand, the regulator section (regulator chamber 1)
A control valve SA3 is disposed on the brake pipe from the pressure regulating mechanism section from j to the booster chamber 1k). Control valve SA3
The brake pipe from the control valve STR intersects with the brake pipe from the control valve STR to the control valves SA1 and SA2, and is branched into two, and control valves SRRH and SRLH are disposed on the brake pipe, respectively. The control valves SRRH and SRLH are each connected to the wheel cylinder 11 of each rear wheel. Control valve SA3 is controlled by control valve S
Controlled together with TR, the hydraulic pressure transmitted to the rear wheel cylinder 11 is switched between the hydraulic pressure from the regulator unit and the hydraulic pressure from the accumulator 4.

Control valves SRRH, SRLH and wheel cylinder 11
From there, the brake pipe is further branched, and control valves SRRR and SRLR are provided respectively. The control valves SRRR and SRLR are
It communicates with the reservoir tank 2. These control valves SRR
Using H, SRLH, SRRR, SRLR, boost mode, hold mode,
Switching the pressure reduction mode is the same as that of the front wheel side.

The above-described control valve 10 performs braking control during normal braking and during ABS, TRC, and VSC. The driving states of the control valve 10 and the like during each control will be described later. In the present embodiment, a brake pipe for automatically braking the vehicle is formed on the left side in FIG. 1 in addition to the above-described braking control at the time of normal braking, ABS, TRC, and VSC.

In the vehicle of the present embodiment, the brake pipe used for automatic braking is used for the above-described normal braking or AB braking.
It is formed independently of the brake piping used for S, TRC, and VSC, and can be retrofitted. For this reason, it is possible to flexibly cope with, for example, setting a mechanism for detecting a preceding vehicle and performing automatic braking as an option, and assembling the vehicle only when necessary.

The mechanism for automatic braking includes a pair of control valves SACCH1 and SACCH2 serving as pressure increasing valves, one control valve SACCR serving as a pressure reducing valve, and a brake pipe connecting these. A brake pipe from the accumulator 4 to the control valve STR is branched on the way, and is connected to the brake pipe from the control valve STR to the control valves SA1 and SA2 via the control valves SACCH1 and SACCH2. Control valve SACCH1 and control valve SACCH2 are arranged in series on the brake pipe. Also, the control valve SACC
The brake pipe branches from between H1 and the control valve SACCH2,
Via a control valve SACCR, it is connected on a brake pipe from the regulator to the control valve STR.

The control valves SACCH1 and SACCH2 can be opened and closed at a predetermined duty ratio. The control valve SACCH1 shuts off the brake pipe when not controlled, and the control valve SACCH2 opens the brake pipe when not controlled. . Also, the control valve SACCR
Shuts off the brake pipe when not controlled. As described above, in the vehicle according to the present embodiment, since a mechanism for automatic braking can be retrofitted, the filter 12 for removing foreign matter in the brake piping mixed at the time of mounting is mounted on the brake piping. is set up.

The pump motor 3, the stop lamp switch 6, the master cylinder pressure sensor 7, the pressure switch 8, and all the control valves 10, as shown in FIG.
It is connected to the ECU 13. The ECU 13 is connected to various sensors for detecting the running state of the vehicle, in addition to the above-described ones. Various sensors connected to the ECU 13 will be described below.

The laser radar sensor 14, which is an object detecting means for detecting an object in front of the vehicle, is attached to the front of the vehicle, irradiates a laser beam forward, and uses the reflected light to determine whether or not there is an object such as a preceding vehicle. It detects the distance to the object and the relative speed to the object. It goes without saying that other detection means such as a millimeter wave radar using millimeter waves instead of laser light may be used as the object detection means.

The wheel speed sensor 15 is attached to each wheel, and detects the rotation speed of each wheel. The ECU 13 calculates the vehicle speed of the vehicle based on the detection result of the wheel speed sensor 15. The yaw rate sensor 16 detects a yaw rate of the vehicle. The linear G sensor 17 detects acceleration in the front-rear direction and left-right direction of the vehicle. The steering angle sensor 18 detects the steering angle of the steering wheel.
The ECU 13 determines the running state and driving state of the vehicle from the detection results of the various sensors described above.

ECU 1 to which the various sensors described above are connected
Reference numeral 3 denotes a microcomputer, which controls the braking control of the vehicle and other controls, and functions as a running state detecting means together with the various sensors described above. Also,
The ECU 13 functions as a valve control unit and an automatic braking unit together with the components shown in FIG. 1 described above.

A case where automatic braking is performed by the brake control device having the above-described configuration will be described.

The detection results of the various sensors described above are stored in the ECU 13
It is determined at regular intervals (for example, every few milliseconds) by a program stored in the ECU 13 whether or not it is necessary to perform automatic braking based on the traveling state calculated by the ECU 13. ing. For example, if the laser radar sensor 14 detects a preceding vehicle traveling at a lower speed than the own vehicle speed during the execution of an auto cruise system that travels at a set speed at a constant speed, automatic braking is necessary. Is determined. It should be noted that the determination of necessity of the automatic braking may be performed only when the vehicle state satisfies a certain condition, or the necessity of the automatic braking may be determined only when a switch operable by the driver is turned on. The determination may be made.

When the ECU 13 determines that automatic braking is necessary, the control valve 10 is set to the state shown in FIG. 3 to perform automatic braking. That is, the control valve SA3 is turned on from the non-control state shown in FIG.
The SACCH 2 is opened and closed at a predetermined duty ratio, and the hydraulic pressure stored in the accumulator 4 is supplied to the wheel cylinder 11 of the rear wheel. At this time, the control valves SACCH1 and SACCH2
FIG. 4 shows the open / closed state of.

As shown in FIG. 4, the control valves SACCH1, SAC
CH2 is opened and closed at a predetermined duty ratio so as to be simultaneously opened and closed. Here, the control valves SACCH1, SAC
Since CH2 is opened and closed at a predetermined duty ratio without being opened at a stretch, the hydraulic pressure in the accumulator 4 can be gradually transmitted to the wheel cylinder 11 of the rear wheel. As a result, it is possible to make the rise of the braking force generated by the rear wheels moderate to some extent without being abrupt.

On the other hand, when it is necessary to reduce the braking force during automatic braking, that is, when reducing the oil pressure of the wheel cylinder 11 for the rear wheels, the control valve SACCR is turned on at a predetermined duty while the control valve SA3 is kept on. Open and close by ratio. Thereby, the hydraulic pressure of the rear wheel cylinder 11 can be gradually returned to the regulator. As a result, the braking force generated by the rear wheels can be moderately released.

The braking force required during the automatic braking is
It is calculated by the ECU 13 based on the running state of the vehicle detected by various sensors. The control valves SACCH1 and SACCH2 or the control valve S are controlled so that the required braking force is obtained.
A duty ratio for opening and closing the ACCR is calculated by the ECU 13. The ECU 13 sends a control signal to the control valve SACCH1, SACCH2 or the control valve SACCR to open and close the control valve SACCH1, SACCH2 or the control valve SACCR at the determined duty ratio.

During this automatic braking, control valves SACCH1 and S
The hydraulic pressure of accumulator 4 via ACCH2 is not transmitted,
The front wheel cylinder 11 is provided in the master cylinder chamber 1i.
Has been communicated with. Therefore, when the driver operates the brake pedal 5 during automatic braking, the master cylinder piston 1c is slid to the left in FIG. 1 to increase the hydraulic pressure inside the master cylinder chamber 1i, and this hydraulic pressure is applied to the front wheels. The power is transmitted to the wheel cylinder 11.

At this time, since the brake pedal 5 reliably strokes, it is possible to reliably detect that the brake pedal has been operated by the stop lamp switch 6 attached to the brake pedal. When it is detected that the brake pedal 5 has been operated during the automatic braking, it is considered that the driver wants to perform braking by his / her own will (for example, to obtain further braking force in addition to the automatic braking). Therefore, the ECU 13 controls the control valve 10 to release the automatic braking state.

When the automatic braking is released, the control valves SACCH1 and S
The states of ACCH2, SACCR, and SA3 may be set to the states shown in FIG. At this time, the hydraulic pressure applied to the rear wheel cylinder 11 during the automatic braking is returned to the regulator through the control valve SA3. Therefore, when the brake pedal 5 is operated during automatic braking, the hydraulic pressure of the master cylinder chamber 1i is transmitted to the front wheel cylinder 11 according to the operation amount of the brake pedal 5, and the rear wheel cylinder 11 The hydraulic pressure of the regulator unit adjusted together with the hydraulic pressure returned from the wheel cylinder 11 of the rear wheel when automatic braking is released is transmitted to the normal braking state.

According to the brake control device of the present embodiment,
When the brake pedal 5 is operated during automatic braking, the operation can be reliably detected, and the automatic braking state can be quickly released by this detection. In particular, when the automatic braking is performed when an object ahead of the vehicle is detected, the driver operates the brake pedal 5 when the braking state under the automatic braking state is different from the braking state intended by the driver. Then, by the natural driving action of operating the brake pedal 5, the automatic braking state can be reliably and promptly released.

In order to detect that the brake pedal 5 has been operated, a stop lamp switch 6 for detecting that the stroke amount of the brake pedal 5 has exceeded a predetermined value is used. Therefore, no special mechanism is required to detect the operation of the brake pedal 5,
The operation of the brake pedal 5 can be detected reliably and easily.

Even if the accumulator 4 and the mechanism for transmitting the hydraulic pressure of the accumulator 4 are out of order, the operation pedal force of the brake pedal 5 during the automatic braking can be transmitted to the front wheels. For this reason, even when such a failure occurs, the pedaling force cannot be boosted, but the vehicle can be braked. At this time, since the front cylinder wheel cylinder 11 is in communication with the master cylinder chamber 1i, braking is performed on the front wheels whose contact load increases, and effective braking can be performed.

On the other hand, for example, consider a case where each control valve 10 during automatic braking is controlled as shown in FIG. In the case shown in FIG. 5, the hydraulic pressure of the accumulator 4 from the control valves SACCH1 and SACCH2 is transmitted to all of the front and rear wheels to perform automatic braking. The state shown in FIG. 5 can be said to be a state in which the control valves SA1 and SA2 are further turned on from the state shown in FIG.

In the case shown in FIG. 5, since the hydraulic pressure from the accumulator 4 is transmitted to all the front and rear wheels, even if the brake pedal 5 is operated,
The brake oil in the master cylinder chamber 1i and the regulator has no place to go, and the brake pedal 5 hardly strokes. For this reason, it is very difficult to reliably detect that the brake pedal 5 has been operated.

Incidentally, even if there is no place for the master cylinder chamber 1i and the brake oil to go to the regulator section, the amount that can be slid until the regulator piston 1f bottoms out is as follows.
The operating rod 1a slides for the backlash between the components from the brake pedal 5 to the master cylinder 1. However, at this time, the sliding amount of the operating rod 1a is several millimeters, and the brake pedal 5 hardly makes a stroke, so that it is very difficult to reliably detect the operation.

In particular, the brake pedal 5 is usually mounted on a production line that is flowing, and it is inevitable that a certain level of mounting error occurs. For this reason, it is very difficult to detect the operation of the brake pedal 5 with the above-described slight slide amount smaller than the assembly error. Some vehicles may be able to detect the operation of the brake pedal 5, but it is very difficult to detect the operation of the brake pedal 5 in all vehicles produced. If you try to work on the production line to reduce the assembly error so that even a stroke amount of several millimeters can be reliably detected, the assembly time must be extremely long, which makes production efficiency unrealistic. It becomes a target.

On the other hand, since the vehicle of this embodiment has the above-described brake control device, a sufficient stroke amount can be obtained even if the brake pedal 5 is operated during automatic braking, and the brake pedal 5 Operation can be detected.

Here, consider using the master cylinder pressure sensor 7 to detect that the brake pedal 5 has been operated. In the case of this embodiment, the stop lamp switch 6 and the master cylinder pressure sensor 7 are used in combination,
If the operation of the brake pedal 5 is detected based on the detection results of both, reliability is further improved. Further, if the stop lamp switch 6 and the master cylinder pressure sensor 7 are used in combination, even if the master cylinder pressure sensor 7 fails, the operation of the brake pedal 5 can be reliably detected only by the stop lamp switch 6. be able to.

On the other hand, in the case shown in FIG. 5, the operation of the brake pedal 5 can be detected by the master cylinder pressure sensor 7, but if the master cylinder pressure sensor 7 fails, the brake pedal 5 Is very difficult to detect as described above.

In the case shown in FIG. 5, when the operation of the brake pedal 5 is detected by the master cylinder pressure sensor 7 during the automatic braking and the automatic braking state is released, the oil pressure of the wheel cylinder 11 is controlled by the control valve SA3. Not only returns to the regulator section via the control valve SA1, but also returns to the master cylinder chamber 1i via the control valves SA1 and SA2. For this reason, the pedal shock when the brake pedal 5 is operated during the automatic braking increases. In the case of the present embodiment shown in FIG.
When the automatic braking is released, the hydraulic pressure of the wheel cylinder 11 returns only to the regulator section, so that a very natural pedal feel can be obtained even if the brake pedal 5 is operated during the automatic braking.

As described above, the brake control apparatus according to the present embodiment can be used for ABS, TRC, V
The braking control can be performed also in the SC mode. The brake control at these times will also be briefly described below.

FIG. 6 shows the state of the master cylinder 1 and each control valve 10 during normal braking.

During normal braking, the driver's brake pedal 5
Based on the operation, the hydraulic pressure is adjusted for each wheel cylinder 11
Is transmitted to According to the stroke of the brake pedal 5, the master cylinder piston 1c and the regulator piston 1f slide. Regulator piston 1f
The 1g of the spool valve also slides with the slide of,
Accumulator 4 for regulator chamber 1j gradually
Is transmitted. The hydraulic pressure in the regulator chamber 1j is transmitted to the rear wheel cylinder 11 after passing through the booster chamber 1k.

On the other hand, the volume inside the master cylinder chamber 1i is reduced by the operation of the brake pedal 5, the hydraulic pressure in the master cylinder chamber 1i is increased, and the wheel cylinder 1
1 is transmitted. At this time, the pressure accumulated in the accumulator 4 is introduced into the booster chamber 1k, so that the driver's operation depressing force of the brake pedal 5 is boosted.

At this time, the hydraulic pressure adjusted by the regulator from the regulator chamber 1j to the booster chamber 1k is transmitted to the rear wheel cylinder 11 without being adjusted by the control valves SR * H and SR * R. . Also,
The hydraulic pressure of the master cylinder chamber 1i is also not adjusted by the control valves SF * H and SF * R, and the rear wheel cylinder 11
Is transmitted to . Here, the control valve SR * H indicates the control valves SRRH and SRLH, and the control valve SR * R is the control valve SRR
R, SRLR. The same applies to the control valves SF * H and SF * R.

FIG. 7 shows the state of the master cylinder 1 and each control valve 10 during the ABS operation.

Also during the ABS operation, the hydraulic pressure is applied to the wheel cylinders 1 of each wheel based on the operation of the brake pedal 5 by the driver.
The hydraulic pressure adjusted by the regulator is transmitted to both the front and rear wheels, and the hydraulic pressure is adjusted by the control valves S ** H and S ** R. Here, the control valve S **
H indicates the control valves SFRH, SFLH, SRRH, SRLH. The same applies to the control valve S ** R.

Based on the detection results of various sensors, the ECU 1
When the ECU 13 determines that it is necessary to operate the ABS as a result of examining the running state (braking state) of the vehicle according to 3, the control valves SA1 and SA2 are turned on, and the hydraulic pressure adjusted by the regulator unit is The transmission is performed not only to the rear wheel cylinder 11 but also to the front wheel cylinder. At this time, the hydraulic pressure transmitted to the wheel cylinder 11 of each wheel is adjusted by the control valves S ** H and S ** R. That is, the rotation state of each wheel is determined by the ECU 13 based on the detection result of the wheel speed sensor 15,
The control valves S ** H and S ** R are switched by the ECU 13 to any one of the pressure increasing mode, the holding mode, and the pressure reducing mode so that each wheel does not keep the locked state.

FIG. 8 shows the state of each control valve 10 when the TRC is activated and when the VSC understeer is suppressed.

When the TRC is activated and the VSC understeer is suppressed, the hydraulic pressure accumulated in the accumulator 4 is transmitted to the rear wheel cylinder 11 based on the detection results of various sensors for detecting the running state of the vehicle. . Although only the hydraulic braking is shown here, other controls such as engine output control other than hydraulic braking are performed in parallel during TRC or VSC operation. A description of these other controls is omitted here.

The ECU 1 based on the detection results of various sensors
When the ECU 13 determines that it is necessary to operate the TRC or to suppress the understeer in the VSC as a result of examining the running state of the vehicle by the ECU 3, the control valves STR and SA3 are turned on, and the The hydraulic pressure stored in the emulator 4 is transmitted to the wheel cylinder 11 of the rear wheel.

When the TRC is operating, the hydraulic pressure transmitted to the wheel cylinder 11 of the rear wheel (drive wheel) is controlled by the control valves S ** H, S so that the rear wheel (drive wheel) does not continue to slip. **
Controlled by R. When the VSC understeer is suppressed, the braking of the rear wheels generates a moment for canceling the understeer in the vehicle, thereby suppressing the understeer. Even when the VSC understeer is suppressed, the hydraulic pressure transmitted to the wheel cylinder 11 of the rear wheel is controlled by the control valves S ** H and S ** R.

Each control valve 1 when suppressing VSC oversteer
The state of 0 is shown in FIG.

At the time of VSC oversteer suppression, based on the detection results of various sensors for detecting the running state of the vehicle,
The hydraulic pressure stored in the accumulator 4 is transmitted to the wheel cylinder of the outer front wheel. At this time,
The hydraulic pressure stored in the accumulator 4 is transmitted to the rear wheels as needed. As described above, at the time of VSC operation, other controls such as engine output control are also performed in parallel in addition to braking by hydraulic pressure. A description of these other controls is also omitted here.

The ECU 1 based on the detection results of various sensors
As a result of the examination of the running state of the vehicle by the ECU 3, if the ECU 13 determines that it is necessary to suppress the oversteer in the VSC, the control valves STR and SA3 are turned on, and the control valve 10 corresponding to the turning outer front wheel is turned on. Turn on. FIG. 9 shows a state in which oversteer is suppressed during a left turn, and the control valve SA1 corresponding to the right front wheel is turned on. Thereby, the hydraulic pressure accumulated in the accumulator 4 is transmitted to the wheel cylinders 11 of the turning outer front wheel and the rear wheel.

By the braking of the front wheels on the outside of the turn and the braking of the rear wheels performed when necessary, a moment for canceling oversteer is generated in the vehicle, thereby suppressing oversteer. Even during the VSC oversteer suppression, the hydraulic pressure transmitted to the wheel cylinder 11 is controlled by the control valves S ** H and S ** R.

The brake control device according to the present invention is not limited to the above-described embodiment. For example, in the above-described embodiment, the brake pipe used at the time of the automatic braking can be retrofitted to the normal braking, ABS, TRC,
It was formed independently of the brake pipe used during VSC. However, at the time of automatic braking, if the wheel cylinder 11 of a predetermined wheel can be communicated with the master cylinder 1 and the wheel cylinders 11 of wheels other than the predetermined wheel can be communicated with the accumulator 4, a brake pipe used for automatic braking can be provided. During normal braking, ABS, TRC, VS
It may be integrated with the brake pipe used at the time of C.

[0079]

According to the brake control device of the present invention, the wheel cylinder of a predetermined wheel is communicated with the master cylinder during automatic braking by the automatic braking means, and the wheel cylinders of wheels other than the predetermined wheel are used as a hydraulic pressure source. Since the communication is established, the brake pedal can be reliably stroked. As a result, the operation of the brake pedal under the automatic braking state can be reliably detected, and the automatic braking state can be reliably released at the time of detection.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram of a brake control device according to an embodiment of the present invention when braking is not performed.

FIG. 2 is a configuration block diagram illustrating an embodiment of a brake control device according to the present invention.

FIG. 3 is a system configuration diagram at the time of automatic braking in the device shown in FIG. 1;

FIG. 4 shows a control valve SA at the time of automatic braking in the device shown in FIG.
6 is a timing chart showing operation states of CCH1 and SACCH2.

FIG. 5 is a system configuration diagram when a brake pedal operation cannot be detected during automatic braking.

FIG. 6 is a system configuration diagram during normal braking in the device shown in FIG. 1;

FIG. 7 is a system configuration diagram when the ABS shown in FIG. 1 is operated.

FIG. 8 shows the state of the apparatus shown in FIG.
It is a system configuration diagram at the time of C understeer suppression.

FIG. 9 is a system configuration diagram at the time of suppressing VSC oversteer in the apparatus shown in FIG. 1;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Master cylinder, 2 ... Reservoir tank, 3 ... Pump motor, 4 ... Accumulator, 5 ... Brake pedal, 6 ... Stop lamp switch, 7 ... Master cylinder pressure sensor, 8 ... Pressure switch, 9 ... Relief valve,
10: control valve, 11: wheel cylinder.

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shoji Kanakawa 2-1-1 Asahi-cho, Kariya-shi, Aichi F-term (reference) in Aisin Seiki Co., Ltd. 3D046 BB18 CC02 EE01 HH02 JJ00 LL05 LL23 LL36 LL43

Claims (4)

[Claims] 1. A master cylinder for generating a hydraulic pressure corresponding to an operation force of a brake pedal, a hydraulic pressure source for generating a predetermined hydraulic pressure and accumulating a pressure, and a hydraulic pressure from the master cylinder or the hydraulic pressure source to a wheel cylinder. A plurality of control valves disposed on a plurality of hydraulic pressure transmission paths for transmitting pressure, valve control means for controlling the control valves, running state detecting means for detecting a running state of the vehicle, and the running state detection Automatic braking means for transmitting the hydraulic pressure accumulated in the hydraulic pressure source to the wheel cylinder based on the detection result of the means to automatically brake the vehicle, and brake operation detection for detecting that the brake pedal is operated The valve control means communicates the wheel cylinder of a predetermined wheel with the master cylinder at the time of automatic braking by the automatic braking means, and the valve control means other than the predetermined wheel. A brake control device that causes the wheel cylinder of a wheel to communicate with the hydraulic pressure source and releases the automatic braking state when the automatic braking unit detects the brake pedal operation by the brake operation detection unit. . 2. The brake control device according to claim 1, wherein said traveling state detection means has an object detection function of detecting an object in front of the vehicle. 3. The brake control device according to claim 1, wherein said brake operation detection means is a switch for detecting that a stroke amount of a brake pedal has exceeded a predetermined value. 4. The vehicle according to claim 1, wherein the predetermined wheel is a front wheel.
The brake control device according to any one of the above.