JP4089042B2 - Brake control device for vehicle - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a braking control device for a vehicle that performs various braking controls by applying an output brake hydraulic pressure of an auxiliary hydraulic pressure source to a wheel cylinder via a modulator, and more particularly, braking of a vehicle capable of performing automatic braking control and anti-skid control. Related to the control device.
[0002]
[Prior art]
Recently, automatic brake control that automatically applies a brake fluid pressure to a wheel cylinder in accordance with a traveling state of a vehicle has been attracting attention. In this method, for example, the distance to the opposite object is measured while the vehicle is running, and control is performed so as to automatically apply an appropriate braking force when approaching within a predetermined distance.
[0003]
Such automatic brake control is generally combined with other braking control such as anti-skid control. However, when the anti-skid control is performed during the automatic brake control, inconvenience may occur. For example, in Japanese Patent Application Laid-Open No. 6-1229, when ABS (anti-skid control) is activated during automatic brake operation, the brake pressure is controlled to coincide with a high target value in automatic brake control. It is described that when the brake pressure is controlled to be reduced, held or increased, the brake pressure by the automatic brake operation is increased and controlled according to the ABS operation. In connection with this, it is described that it is expected that the ABS operation will reduce pressure more than necessary and adversely affect each other.
[0004]
Thus, Japanese Patent Laid-Open No. 6-1229 proposes a control method for suppressing an increase in brake fluid pressure when an ABS (anti-skid control) is activated during automatic braking. That is, in the same publication, when the ABS is operated during the automatic brake operation, it is proposed that the brake pressure by the automatic brake operation is kept constant at that time. It has been proposed to control the holding.
[0005]
[Problems to be solved by the invention]
However, since the automatic brake operation described in the above-mentioned Japanese Patent Application Laid-Open No. 6-1229 is performed by duty control of a pressurizing solenoid valve (indicated by 40 in the same publication), the driver feels uneasy. Although the vehicle can be slowly decelerated so as not to give the pressure, an operation sound is generated in which the pressurization solenoid valve is intermittently engaged during the automatic brake operation. Since this may become a noise that cannot be overlooked, it is necessary to take another noise countermeasure.
[0006]
Accordingly, an object of the present invention is to slowly decelerate a vehicle during automatic brake control and suppress noise during operation to reduce noise during automatic brake control.
[0007]
Further, the present invention provides a vehicle braking control apparatus that suppresses operation noise during automatic brake control so that the anti-skid control can be appropriately performed even when the anti-skid control is performed during the automatic brake control. Is an issue.
[0008]
[Means for Solving the Problems]
  In order to solve the above-described problems, a vehicle braking control device according to the present invention includes a wheel cylinder that is attached to each wheel of the vehicle and applies a braking force and an operation of a brake pedal. A hydraulic pressure generating device for generating a brake hydraulic pressure, a modulator interposed between the hydraulic pressure generating device and each of the wheel cylinders, for adjusting a brake hydraulic pressure of the wheel cylinder, the modulator and the hydraulic pressure generating device A shutoff valve device interposed in a main hydraulic pressure path that communicates with the device and opens and closes the main hydraulic pressure path, and is connected in communication between the shutoff valve device and the modulator, and whether or not the brake pedal is operated Irrespective of the auxiliary hydraulic pressure source for applying the brake hydraulic pressure to the wheel cylinder via the modulator, the brake hydraulic pressure of the wheel cylinder is connected to the auxiliary hydraulic pressure source, and the wheel hydraulic pressure is applied to the wheel cylinder with a first pressure increase gradient. A switching valve device for selectively switching between a first position for increasing pressure and a second position for increasing the brake fluid pressure of the wheel cylinder with a second pressure increasing gradient smaller than the first pressure increasing gradient; Braking control means for performing automatic brake control by the output brake hydraulic pressure of the auxiliary hydraulic pressure source in a state where the device is in the closed position and the switching valve device is switched to the second position.The hydraulic pressure generating device comprises a master cylinder that boosts the brake fluid in the low-pressure reservoir in accordance with the operation of the brake pedal and outputs a master cylinder hydraulic pressure, and the auxiliary hydraulic pressure source is provided via the suction passage. The brake fluid of the master cylinder is sucked, and is constituted by a hydraulic pump that discharges the brake fluid pressurized to the wheel cylinder via the modulator, and the switching valve device is interposed in the suction passage. Further, the braking control means is configured to control the modulator to perform at least anti-skid control. When the anti-skid control is started during the automatic brake control, the brake pump outputs brake fluid. The modulator is controlled so that the pressure increase gradient of the wheel cylinder due to pressure becomes large. As a result, the decrement of the output brake hydraulic pressure of the hydraulic pump when the brake fluid is introduced via the switching valve device at the second position is offset by the increase in the pressure increase gradient in the control by the modulator. Anti-skid control is performed.
[0011]
  Or,The braking control meansTheClaim2As described above, when the modulator is controlled to perform at least anti-skid control and the anti-skid control is started during the automatic brake control, the switching valve device is switched to the first position. If the modulator is controlled in such a state, a desired brake fluid pressure is not obtained by the switching valve device, and anti-skid control is appropriately performed.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. First, FIG. 1 shows an embodiment of a braking control device of the present invention. A master cylinder MC is boosted via a vacuum booster VB in response to an operation of a brake pedal BP, and brake fluid in a low pressure reservoir LRS is shown. Is increased so that the master cylinder hydraulic pressure is output to the two brake hydraulic pressure systems on the wheels FR and RL and the wheels FL and RR. The master cylinder MC is a tandem master cylinder having two pressure chambers. One pressure chamber is connected to a brake fluid pressure system on the wheels FR and RL side, and the other pressure chamber is a brake fluid on the wheels FL and RR sides. A so-called X pipe is configured in communication with the pressure system. Note that the wheel FL indicates the front left wheel as viewed from the driver's seat, the wheel FR indicates the front right side, the wheel RL indicates the rear left side, and the wheel RR indicates the rear right wheel.
[0013]
Wheel speed sensors (not shown) are disposed on the wheels FR, FL, RR, and RL, and these are connected to the electronic control unit ECU, and the rotation speed of each wheel, that is, the number of pulses proportional to the wheel speed. The pulse signal is configured to be input to the electronic control unit ECU. A vehicle body acceleration sensor G for detecting vehicle body acceleration is provided, and an output signal thereof is input to the electronic control unit ECU. A pressure sensor PS for detecting the output hydraulic pressure (master cylinder hydraulic pressure) is provided on the output side of the master cylinder MC. In addition, sensors for detecting various signals used for vehicle braking control are provided, but are omitted here.
[0014]
In the brake hydraulic system on the wheel FR, RL side of the present embodiment, one pressure chamber is connected to the wheel cylinders Wfr, Wrl via the main hydraulic path MF and its branched hydraulic paths MFr, MFl, respectively. . The main hydraulic pressure path MF is provided with a normally open first on-off valve SC1 (which functions as a shut-off valve device of the present invention, hereinafter simply referred to as on-off valve SC1). One pressure chamber is connected between check valves CV5 and CV6 described later via an auxiliary hydraulic pressure path MFc. A normally closed second on-off valve SI1 (hereinafter simply referred to as on-off valve SI1) is interposed in the auxiliary hydraulic pressure path MFc. Each of these on-off valves is a 2-port 2-position electromagnetic on-off valve. The branch hydraulic pressure paths MFr and MFl are respectively provided with normally open type two-port two-position electromagnetic on-off valves PC1 and PC2 (hereinafter simply referred to as on-off valves PC1 and PC2). Further, check valves CV1 and CV2 are interposed in parallel with these. Further, a switching valve SA1 constituting the switching valve device of the present invention is disposed upstream of the on-off valve SI1 in the auxiliary hydraulic pressure path MFc. The configuration of the switching valve SA1 will be described later.
[0015]
The check valves CV1, CV2 allow the flow of brake fluid in the direction of the master cylinder MC and restrict the flow of brake fluid in the direction of the wheel cylinders Wfr, Wrl. The check valves CV1, CV2 and the first check valves CV1, CV2 The brake fluid in the wheel cylinders Wfr, Wrl is returned to the master cylinder MC and thus to the low-pressure reservoir LRS via the opening / closing valve SC1 in the position (shown). Thus, when the brake pedal BP is released, the hydraulic pressure in the wheel cylinders Wfr, Wrl can quickly follow the decrease in hydraulic pressure on the master cylinder MC side. Also, normally-closed two-port two-position electromagnetic on-off valves PC5 and PC6 (hereinafter simply referred to as on-off valves PC5 and PC6) are connected to the discharge-side branch hydraulic pressure paths RFr and RFl connected to the wheel cylinders Wfr and Wrl, respectively. Is interposed, and the discharge hydraulic pressure channel RF where the branch hydraulic pressure channels RFr and RFl merge is connected to the reservoir RS1.
[0016]
In the brake hydraulic system on the wheel FR, RL side, the on-off valves PC1, PC2, PC5, PC6 constitute a modulator according to the present invention. A hydraulic pump HP1 is connected between the on-off valves PC1 and PC2 and the first on-off valve SC1 via a pump hydraulic pressure path MFp communicating with the branch hydraulic pressure paths MFr and MFl. A reservoir RS1 is connected via check valves CV5 and CV6. Thus, the discharge side of the hydraulic pump HP1 is connected to the on-off valves PC1 and PC2 via the check valve CV7 and the damper DP1. The hydraulic pump HP1 is driven by one electric motor M together with the hydraulic pump HP2, and is configured to introduce brake fluid from the suction side, increase the pressure to a predetermined pressure, and output from the discharge side. The reservoir RS1 is provided independently of the low pressure reservoir LRS of the master cylinder MC, and can also be referred to as an accumulator. The reservoir RS1 includes a piston and a spring so as to store brake fluid having a capacity necessary for various controls described later. It is configured.
[0017]
In the present embodiment, the switching valve SA1 disposed in the auxiliary hydraulic pressure path MFc, which is the suction path of the hydraulic pump HP1, has a flow area smaller than the first position and the flow area of the first position. It is composed of a 2-port 2-position electromagnetic switching valve that selectively switches the second position to be in a communication state via a throttle (orifice). Here, the “throttle” at the second position is different from the orifice formed in a general solenoid valve, and the characteristics of the wheel cylinder hydraulic pressure through this “throttle” are shown in FIG. Is set so that the wheel cylinder hydraulic pressure is increased with a second pressure increase gradient smaller than the first pressure increase gradient at the first position indicated by the broken line. For example, as shown in FIG. 5, it is set to a gentle pressure increase gradient of change of 2.0 MPa (megapascal) per second.
[0018]
The master cylinder MC is connected in communication between a check valve CV5 and a check valve CV6 on the suction side of the hydraulic pump HP1 via a hydraulic path MFc. The check valve CV5 blocks the flow of brake fluid to the reservoir RS1 and allows a reverse flow. The check valves CV6 and CV7 regulate the flow of brake fluid discharged via the hydraulic pump HP1 in a certain direction, and are normally configured integrally with the hydraulic pump HP1. Thus, the on-off valve SI1 is disconnected from the master cylinder MC and the suction side of the hydraulic pump HP1 at the normal closed position shown in FIG. 1, and the master cylinder MC and the suction side of the hydraulic pump HP1 at the open position. It is switched to communicate.
[0019]
Further, in parallel with the on-off valve SC1, the flow of brake fluid from the master cylinder MC toward the on-off valves PC1 and PC2 is restricted, and the brake fluid pressure on the on-off valves PC1 and PC2 side is less than the brake fluid pressure on the master cylinder MC side. Relief valve RV1 that allows the flow of brake fluid in the direction of the master cylinder MC when the pressure difference exceeds a predetermined pressure difference, and the flow of brake fluid in the directions of the wheel cylinders Wfr and Wrl are allowed and the flow in the reverse direction is prohibited A check valve AV1 is interposed. The relief valve RV1 allows the brake fluid to be supplied to the low pressure reservoir LRS via the master cylinder MC when the pressurized brake fluid discharged from the hydraulic pump HP1 becomes greater than a predetermined differential pressure from the output hydraulic pressure of the master cylinder MC. Thus, the discharge brake fluid of the hydraulic pump HP1 is regulated to a predetermined pressure. Further, a damper DP1 is disposed on the discharge side of the hydraulic pump HP1, and a proportioning valve PV1 is interposed in a hydraulic pressure path leading to the wheel cylinder Wrl on the rear wheel side.
[0020]
Similarly, in the brake hydraulic system on the side of the wheels FL and RR, the reservoir RS2, the damper DP2, the proportioning valve PV2, the two-port two-position electromagnetic switching valve SA2 having the same structure as the switching valve SA1, and the normally-open two-port 2-position electromagnetic on-off valve SC2 (first on-off valve), normally-closed 2-port 2-position electromagnetic on-off valve SI2 (second on-off valve), PC7, PC8, normally-open 2-port 2-position electromagnetic on-off valve PC3 , PC4, check valves CV3, CV4, CV8 to CV10, a relief valve RV2, and a check valve AV2. The hydraulic pump HP2 is driven by the electric motor M together with the hydraulic pump HP1, and after the electric motor M is started, both the hydraulic pumps HP1 and HP2 are continuously driven.
[0021]
Although not shown, the electronic control unit ECU of the present embodiment includes a microcomputer including a processing unit, a memory (ROM, RAM), an input port, and an output that are connected to each other via a bus. Output signals from the vehicle body acceleration sensor G and the wheel speed sensor (not shown) are input to the processing unit via the input ports, respectively. A memory (ROM) stores programs used for various processes including the flowcharts shown in FIGS. 2 to 4, and the processing unit executes the programs while an ignition switch (not shown) is closed. (RAM) temporarily stores variable data necessary for execution of the program.
[0022]
The operation of the embodiment having the above-described configuration will be described. During normal brake operation, each electromagnetic valve is in the normal position shown in FIG. 1, and the electric motor M is stopped. In this state, when the brake pedal BP is depressed, the master cylinder MC is boosted by the vacuum booster VB, and the master cylinder hydraulic pressure is supplied from the two pressure chambers of the master cylinder MC to the wheels FR and RL and the wheels FL and RR, respectively. Is supplied to the wheel cylinders Wfr, Wrl, Wfl, Wrr via the on-off valves SC1, SC2 and the on-off valves PC1 to PC8.
[0023]
For example, when the control is shifted to the anti-skid control during the brake operation, and it is determined that the wheel FR side tends to be locked, for example, the on-off valve SC1 remains in the open position, and the on-off valve PC1 is closed. PC5 is set to the open position. Thus, the wheel cylinder Wfr communicates with the reservoir RS1 via the on-off valve PC5, and the brake fluid in the wheel cylinder Wfr flows into the reservoir RS1 and is depressurized.
[0024]
When the wheel cylinder Wfr is in the pulse pressure increasing mode, the on-off valve PC5 is closed and the on-off valve PC1 is opened, and the master cylinder hydraulic pressure from the master cylinder MC passes through the on-off valve PC1 in the open position. Supplied to Wfr. Then, the on-off valve PC1 is intermittently controlled, and the brake fluid in the wheel cylinder Wfr is repeatedly increased and held to increase in a pulsed manner and gradually increase in pressure. When the rapid pressure increasing mode is set for the wheel cylinder Wfr, the on-off valves PC2 and PC5 are closed, and then the on-off valve PC1 is opened, and the master cylinder hydraulic pressure is supplied from the master cylinder MC. When the brake pedal BP is released and the master cylinder hydraulic pressure becomes smaller than the hydraulic pressure in the wheel cylinder Wfr, the brake fluid in the wheel cylinder Wfr passes through the check valve CV1 and the open / close valve SC1 in the open position. Return to MC, and thus to low pressure reservoir LRS. In this way, independent braking force control is performed for each wheel.
[0025]
Next, for example, when the distance between the vehicle and the opposing object is shortened and automatic brake control is performed, the on-off valves SC1 and SC2 are switched to the closed position, and the on-off valves SI1 and SI2 are switched to the open position. The switching valves SA1 and SA2 are switched to the second position. Thus, even when the brake pedal BP is not operated, during the automatic brake control, the hydraulic pumps HP1 and HP2 are driven, but the fluid is passed through the switching valves SA1 and SA2 (throttles) at the second position. Since brake fluid is introduced into the pressure pumps HP1 and HP2, the output brake fluid pressure of the hydraulic pumps HP1 and HP2 gradually increases, and the brake fluid pressure of each wheel cylinder gradually increases. In this case, the switching valves SA1 and SA2 are not frequently intermittently operated by duty control unlike the pulse pressure increasing mode, so that a large operating noise is not generated. The hydraulic pressure control when the anti-skid control is performed in this state is different from the above-described hydraulic pressure control, which will be described later with reference to FIGS.
[0026]
According to the braking control device of the present embodiment, in addition to the above control, the traction control during acceleration slip of the driving wheel and the braking force distribution between the front and rear wheels are controlled so that the course trace performance of the vehicle can be maintained. Various controls such as brake steering control can be performed, but the description thereof will be omitted.
[0027]
The switching valves SA1, SA2, on-off valves SC1, SC2, SI1, SI2 and on-off valves PC1 to PC8 are driven and controlled by an electronic control unit ECU, and a series of processes such as automatic brake control and anti-skid control are performed. When (not shown) is closed, execution of a program corresponding to the flowcharts of FIGS. 2 to 4 and the like starts. FIG. 2 shows a main routine for performing the automatic brake control and the anti-skid control. First, at step 101, initialization is performed and various calculation values are cleared. Next, after waiting for a predetermined time (for example, 6 ms) in step 102 to stabilize, a detection signal of a wheel speed sensor (not shown) is read in step 103 and a detection signal of the vehicle body acceleration sensor G is actually detected. It is read as vehicle acceleration Ga.
[0028]
Next, the routine proceeds to step 104, where the wheel speed Vw ** (** represents each wheel FR, etc.) of each wheel is calculated. In step 105, the maximum value of the wheel speed Vw ** of each wheel is the vehicle center of gravity position. Is calculated as an estimated vehicle speed Vso (Vso = MAX (Vw **)). Further, if necessary, an estimated vehicle speed Vso ** is obtained for each wheel based on the wheel speed Vw ** of each wheel. Subsequently, in step 106, a target vehicle body acceleration Gt used for automatic brake control is calculated based on, for example, the proximity ratio with the opposite object.
[0029]
Then, the process proceeds to step 107, where automatic brake control is performed based on the comparison result between the target vehicle acceleration Gt obtained in step 106 and the actual vehicle acceleration Ga detected by the vehicle acceleration sensor G. That is, until the actual vehicle body acceleration Ga becomes equal to the target vehicle body acceleration Gt, the brake fluid is introduced into the hydraulic pumps HP1 and HP2 via the switching valves SA1 and SA2 (throttles) at the second position, and the hydraulic pump HP1. , HP2 gradually increases the brake fluid pressure supplied to each wheel cylinder. Further, if necessary, anti-skid control is performed in step 108. This anti-skid control will be described later.
[0030]
FIG. 3 shows the specific processing contents of the anti-skid control in step 108 of FIG. 2. First, in step 201, it is determined whether or not the anti-skid control (shown as “ABS control” in the figure) is before. If it is before anti-skid control, it is determined in step 202 that anti-skid control is started. If the anti-skid control is already being performed, the process proceeds from step 201 to step 203, where the end of anti-skid control is determined.
[0031]
In step 204, it is determined whether or not anti-skid control is being performed. If anti-skid control is being performed, in step 205, for example, the slip ratio of the wheel (calculated based on the calculation results of steps 104 and 105) is set. Accordingly, the pressure reduction mode, the pulse pressure reduction mode, or the pulse pressure increase mode is set. Thus, it is determined in step 206 whether or not the decompression mode (including the pulse decompression mode) is selected. If so, a decompression signal or a pulse decompression signal is output in step 207.
[0032]
If it is determined in step 206 that the pressure reduction mode is not selected, the process proceeds to step 208 to determine whether or not the pulse pressure increase mode is selected. If so, automatic brake control (indicated by “ACC control” in the figure) is performed in step 209. ) Is being executed. When the automatic brake control is being performed, the process proceeds to step 210 and a specific pulse pressure increasing signal is output. The specific pulse pressure increase signal is set to have a pressure increase gradient larger than a normal (not during automatic brake control) pulse pressure increase signal indicated by a solid line as indicated by a broken line in the upper part of FIG. 6 (for example, , Duty ratio is 10 times). In FIG. 6, the “open / close valve” is any of the open / close valves PC1 to PC4 of FIG. 1 connected to the wheel cylinder to be controlled, the broken line represents the specific pulse boost signal, and the solid line represents the normal pulse boost signal. Represents. Thus, the decrement of the output brake hydraulic pressure of the hydraulic pumps HP1 and HP2 when supplied through the restriction of the switching valves SA1 and SA2 is offset by the pressure increase gradient of the specific pulse pressure increase signal. Anti-skid control can be performed appropriately.
[0033]
If it is determined in step 209 that the automatic brake control is not being performed, the routine proceeds to step 211, where a normal pulse pressure increasing signal is output, and the routine returns to the routine of FIG. Further, if it is determined in step 204 that the anti-skid control is not being performed, or if it is determined in step 208 that it is not in the pulse pressure increasing mode, the routine proceeds to step 212 and a rapid pressure increasing signal is output and the routine of FIG. Return to.
[0034]
FIG. 4 shows another embodiment of the anti-skid control in step 108 of FIG. 2. In step 301, it is determined whether or not the anti-skid control is performed. If it is before anti-skid control, the anti-skid control start determination is performed in step 302, and if anti-skid control is being performed, the anti-skid control end determination is performed in step 303.
[0035]
Subsequently, the process proceeds to step 304 to determine whether or not the anti-skid control is being performed. If the anti-skid control is being performed, in step 305, one of the hydraulic pressure modes is set according to the slip ratio of the wheel. Thus, it is determined in step 306 whether or not the decompression mode is selected. If so, a decompression signal or a pulse decompression signal is output in step 307. If it is determined in step 306 that the pressure reduction mode is not selected, the process proceeds to step 308 to determine whether or not the pulse pressure increase mode is selected. If so, a pulse pressure increase signal is output in step 309. If it is determined in step 304 that the anti-skid control is not being performed, or if it is determined in step 308 that it is not in the pulse pressure increasing mode, the process proceeds to step 310 and a rapid pressure increasing signal is output.
[0036]
In step 311, it is determined whether automatic brake control is being performed. If automatic brake control is not in progress, the routine proceeds to step 312, where the switching valves SA1 and SA2 are kept off, and the routine returns to the routine of FIG. If it is determined in step 311 that automatic brake control is being performed, it is determined in step 313 whether or not anti-skid control is in progress. If it is before anti-skid control, the switching valves SA1 and SA2 are turned on in step 314, and automatic brake control is performed. Then, the process proceeds to step 315, and a pressure-increasing signal is output to the wheel cylinders of the ABS non-control wheels that are not controlled by the anti-skid this time, and the on-off valves PC1 to PC4 related to the non-control wheels are output. It is turned off (open position). Thus, the brake fluid pressure for the wheel cylinder of the non-control wheel is not made insufficient due to the decrease in the pressure increase gradient accompanying the automatic brake control, and an appropriate brake fluid pressure is applied.
[0037]
If it is determined in step 313 that the anti-skid control is being performed, the process proceeds to step 316, where the actual vehicle acceleration (Ga) is compared with the target vehicle acceleration (Gt). Here, if it is determined that the actual vehicle body acceleration (Ga) is less than the target vehicle body acceleration (Gt), it means that a sufficient deceleration has been obtained, so that the routine proceeds to step 314 and the switching valves SA1 and SA2 are turned on ( 2nd position), and automatic brake control is performed. Also in this case, a pressure increase signal is output at step 315 to the wheel cylinder of the non-control wheel, and the necessary braking force is ensured.
[0038]
On the other hand, if it is determined in step 316 that the actual vehicle acceleration (Ga) is greater than or equal to the target vehicle acceleration (Gt), the anti-skid control is prioritized because the deceleration is insufficient, and step 317 is performed. Thus, the switching valves SA1 and SA2 are turned off. Accordingly, the brake hydraulic pressure supplied from the hydraulic pumps HP1 and HP2 to the wheel cylinder of the anti-skid control target wheel is not limited by the restriction of the switching valves SA1 and SA2. At this time, a hold or pulse pressure increase signal is output to the non-control wheels so as not to increase pressure more than necessary. In this case, since it is necessary to maintain the on-off valve SI1 in the on position so that the pressure on the wheel cylinder to be controlled can be increased, when the wheel cylinder of the non-control wheel is held, the on-off valve SC1 is The on-off valve PC1 is in the closed position with the on-state (closed position) and the on-off valve SI1 on (open position).
[0039]
FIG. 7 shows another embodiment of the braking control device of the present invention. The hydraulic pressure generating device comprises a master cylinder MC and a regulator RG, and the auxiliary hydraulic pressure source is a hydraulic pump HP3 driven by an electric motor M. A check valve CV11 and an accumulator AC connected to the discharge side of the accumulator AC are connected to a regulator RG, and a relief valve RV3 is interposed therebetween. The hydraulic pump HP3 is driven when the low pressure detection switch PL is turned on, and is stopped when the high pressure detection switch PH is turned on. In this embodiment, the master cylinder MC is connected in communication with the brake hydraulic system of the wheels FR and FL in front of the vehicle, and the regulator RG is connected in communication with the brake hydraulic system of the wheels RR and RL in the rear of the vehicle. Is configured. The modulator is configured in the same manner as the embodiment of FIG. 1 and includes on-off valves PC1 to PC8.
[0040]
In the embodiment of FIG. 7, a normally-open 2-port 2-position electromagnetic on-off valve SC3 (hereinafter simply referred to as on-off valve SC3) that constitutes a shut-off valve device between the rear-wheel side on-off valves PC2, PC4 and the regulator RG. ) Is interposed, but between the front wheel side opening / closing valves PC1 and PC3 and the master cylinder MC, three-port two-position electromagnetic switching valves ST1 and ST2 (hereinafter simply referred to as switching valves ST1 and ST2) are interposed, respectively. It is disguised. These switching valves ST1 and ST2 also constitute the shutoff valve device of the present invention, and the first position where the on-off valves PC1 and PC3 communicate with the master cylinder MC and the communication between the master cylinder MC and the on-off valves PC1 and PC3 are shut off. Is switched to a second position where the accumulator AC is connected to the accumulator AC, and is normally set to the first position as shown in FIG.
[0041]
Further, the switching valve STR and the switching valve STS constituting the switching valve device of the present invention are arranged in parallel between the switching valves ST1, ST2 and the switching valve SC3 and the modulator, and between the accumulator AC. These are normally closed two-port two-position electromagnetic on-off valves, but the open position side of the on-off valve STS is configured in the same manner as the second position side of the switching valve SA1 in FIG. That is, the open position side of the on-off valve STS is configured to communicate with a throttle (orifice) having a flow area smaller than that of a normal internal communication path. In addition, about the structure of other components, the code | symbol similar to FIG. 1 is attached | subjected and description is abbreviate | omitted.
[0042]
Thus, at the time of automatic brake control, the on-off valve SC3, which is a shut-off valve device, is closed, the switching valves ST1, ST2 are switched to the second position, and the on-off valve STR, which is a switching valve device, is closed. At the same time, the brake fluid pressure from the accumulator AC is supplied to each wheel cylinder via the throttle of the on-off valve STS (further via the modulator) in a state where the on-off valve STS is in the open position. When anti-skid control is performed during automatic brake control, the same processing as step 210 in FIG. 3 is performed under the control of the modulator. When traction control, braking steering control, or the like is performed, the on-off valve STR is in the open position, the on-off valve STS is in the closed position, and the brake hydraulic pressure from the accumulator AC is not passed through the throttle of the on-off valve STS. Is supplied to each wheel cylinder via the on-off valve STR (further via a modulator).
[0043]
【The invention's effect】
  Since this invention is comprised as mentioned above, there exist the following effects. That is, in the vehicle braking control apparatus of the present invention, a shut-off valve device is provided in the main hydraulic pressure path that connects the modulator and the hydraulic pressure generator, and an auxiliary hydraulic pressure source is provided between the shut-off valve device and the modulator. Are connected, and a first position for increasing the brake fluid pressure of the wheel cylinder with a first pressure increase gradient and a second position for increasing the brake fluid pressure of the wheel cylinder with a second pressure increase gradient smaller than this are provided. A switching valve device for selectively switching is connected to an auxiliary hydraulic pressure source, and an automatic brake control is performed by an output brake hydraulic pressure of the hydraulic pressure generating device in a state where the shut-off valve device is closed and the switching valve device is switched to the second position. Configured to doThe hydraulic pressure generating device is constituted by a master cylinder, the auxiliary hydraulic pressure source is constituted by a hydraulic pressure pump for sucking brake fluid of the master cylinder through an intake passage, and the switching valve device is provided in the intake passage. To beTherefore, the vehicle can be slowly decelerated during the automatic brake control, and the noise during the automatic brake control can be reduced while suppressing the operation noise.When anti-skid control is started during automatic brake control, the modulator is controlled so that the pressure increase gradient of the wheel cylinder due to the output brake hydraulic pressure of the hydraulic pump becomes large. The anti-skid control can be appropriately performed even when the anti-skid control is performed during the brake control.
[0046]
  Or claims2If the anti-skid control is started during the automatic brake control, the modulator is controlled with the switching valve device switched to the first position, so that the anti-skid control can be performed during the automatic brake control. Antiskid control can be appropriately performed even when the control is performed.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing an embodiment of a braking control device for a vehicle according to the present invention.
FIG. 2 is a flowchart showing the entire braking control of the vehicle in one embodiment of the present invention.
FIG. 3 is a flowchart showing a main routine of automatic brake control and anti-skid control in one embodiment of the present invention.
FIG. 4 is a flowchart showing another example of the anti-skid control in the embodiment of the present invention.
FIG. 5 is a graph showing a hydraulic pressure characteristic of a switching valve in one embodiment of the present invention.
FIG. 6 is a graph showing wheel cylinder hydraulic pressure characteristics in a pulse pressure increasing mode according to an embodiment of the present invention.
FIG. 7 is a block diagram showing another embodiment of the vehicle braking control apparatus of the present invention.
[Explanation of symbols]
BP brake pedal,
MC master cylinder, RG regulator,
M electric motor, HP1, HP2, HP3 hydraulic pump,
RS1, RS2 reservoir,
SA1, SA2, ST1, ST2 switching valve,
SC1, SC2, SC3, STR, STS on-off valve,
SI1, SI2 on-off valve, PC1-PC8 on-off valve,
ECU electronic control unit,
Wfr, Wfl, Wrr, Wrl Wheel cylinder,
FR, FL, RR, RL wheels

Claims (2)

A wheel cylinder that is attached to each wheel of the vehicle and applies a braking force, a hydraulic pressure generator that generates a brake hydraulic pressure in response to an operation of a brake pedal, and between the hydraulic pressure generator and the wheel cylinder A modulator that adjusts the brake hydraulic pressure of the wheel cylinder, and a shutoff valve device that opens and closes the main hydraulic pressure path interposed in a main hydraulic pressure path that connects the modulator and the hydraulic pressure generating device. An auxiliary hydraulic pressure source that is connected in communication between the shut-off valve device and the modulator and applies brake hydraulic pressure to the wheel cylinder via the modulator regardless of whether or not the brake pedal is operated; A first position for connecting to a hydraulic pressure source and increasing the brake hydraulic pressure of the wheel cylinder with a first pressure increasing gradient; and a second pressure increasing gradient smaller than the first pressure increasing gradient. A switching valve device that selectively switches the second position for increasing the brake fluid pressure of Linda, and the auxiliary hydraulic pressure source in a state where the shut-off valve device is closed and the switching valve device is switched to the second position. Braking control means for performing automatic brake control by output brake fluid pressure, and the fluid pressure generating device is a master cylinder that boosts the brake fluid in the low-pressure reservoir according to the operation of the brake pedal and outputs a master cylinder fluid pressure. The auxiliary hydraulic pressure source is configured by a hydraulic pump that sucks brake fluid of the master cylinder through a suction passage and discharges brake fluid that has been boosted to the wheel cylinder through the modulator. The switching valve device is interposed in the suction passage, and the braking control means is configured to control the modulator and perform at least anti-skid control. While, when starting the anti-skid control in the automatic brake control, said fluid pressure pump output brake fluid pressure according to the pressure increase gradient of the wheel cylinder to control the modulator such that the large A vehicle braking control device. A wheel cylinder that is attached to each wheel of the vehicle and applies a braking force, a hydraulic pressure generator that generates a brake hydraulic pressure in response to an operation of a brake pedal, and between the hydraulic pressure generator and the wheel cylinder A modulator that adjusts the brake hydraulic pressure of the wheel cylinder, and a shutoff valve device that opens and closes the main hydraulic pressure path interposed in a main hydraulic pressure path that connects the modulator and the hydraulic pressure generating device. An auxiliary hydraulic pressure source that is connected in communication between the shut-off valve device and the modulator and applies brake hydraulic pressure to the wheel cylinder via the modulator regardless of whether or not the brake pedal is operated; A first position for connecting to a hydraulic pressure source and increasing the brake hydraulic pressure of the wheel cylinder with a first pressure increasing gradient; and a second pressure increasing gradient smaller than the first pressure increasing gradient. A switching valve device that selectively switches the second position for increasing the brake fluid pressure of Linda, and the auxiliary hydraulic pressure source in a state where the shut-off valve device is closed and the switching valve device is switched to the second position. Braking control means for performing automatic brake control by output brake fluid pressure, and the fluid pressure generating device is a master cylinder that boosts the brake fluid in the low-pressure reservoir according to the operation of the brake pedal and outputs a master cylinder fluid pressure. The auxiliary hydraulic pressure source is configured by a hydraulic pump that sucks brake fluid of the master cylinder through a suction passage and discharges brake fluid that has been boosted to the wheel cylinder through the modulator. the switching valve device interposed to said suction passage, said braking control means is configured to perform the control at least the anti-skid control said modulator To together, when starting the anti-skid control in the automatic brake control, the brake control device for a vehicle shall be the controls said modulator in a state in which switches the switching valve device in the first position.

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