JP2018192900A - Brake device for vehicle - Google Patents

Abstract

To provide a brake device for a vehicle which can suppress application of a large load to electric motor power supply when reducing brake force generated at left and right wheels by activating each electric brake mechanism.SOLUTION: Electric brake mechanisms 31L, 31R which are possessed by a brake device are constituted so as to adjust brake force generated at rear wheels RL, RR by controlling pressing force being force for pressing friction materials 23A, 23B to a rotating body 22 which rotates integrally with the rear wheels RL, RR by driving of an electric motor 33. The brake device performs antilock control for starting to drive the electric motor 33 corresponding to the rear wheels in order to reduce the pressing force for the rotating body 22 which rotates integrally with the rear wheels whose slip rate is low out of both the rear wheels RL, RR, and after that, starting to drive the electric motor 33 corresponding to the rear wheels in order to reduce the pressing force for the rotating body 22 which rotates integrally with the rear wheels whose slip rate is high.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a vehicle braking device including an electric braking mechanism corresponding to each of left and right wheels of a vehicle.

  2. Description of the Related Art A vehicular braking device including an electric braking mechanism corresponding to each of left and right wheels of a vehicle is known. Each electric braking mechanism is configured so that the braking force generated by the wheel can be adjusted by controlling the pressing force, which is the force pressing the friction material against the rotating body that rotates integrally with the wheel by driving the electric motor. . In a vehicle provided with such a vehicle braking device, the braking force generated by both the left and right wheels may be increased by operating each electric braking mechanism while the vehicle is running. Then, under a situation where braking force is generated on both the left and right wheels by the operation of each electric braking mechanism, either one of the wheels may decelerate and slip. At this time, in the vehicle braking apparatus described in Patent Document 1, when the vehicle is traveling at a high speed, the vehicle behavior is reduced by reducing the braking force generated by the left and right wheels by the operation of each electric braking mechanism. It is intended to suppress a decrease in stability.

JP 2016-124409 A

  In the vehicle braking device as disclosed in Patent Document 1, each of the electric braking mechanisms is operated to reduce the braking force generated at both wheels because deceleration slip has occurred at one of the left and right wheels. In this case, if the electric motors of the respective electric braking mechanisms are activated at the same time, the time when the inrush current generated at the activation of the electric motors reaches the peak value may overlap. Thus, when the time when the inrush current generated in each electric motor reaches the peak value overlaps, there is a possibility that a great load is applied to the power source for the electric motor.

  The vehicular braking apparatus for solving the above-described problems includes an electric braking mechanism corresponding to each of the left and right wheels of the vehicle. Each of the electric braking mechanisms is configured to adjust a braking force generated by the wheel by controlling a pressing force that is a force pressing a friction material against a rotating body that rotates integrally with the wheel by driving an electric motor. Has been. Further, the vehicle braking device includes a braking control unit that executes a braking process for increasing a braking force generated by the left and right wheels by operating the electric braking mechanisms in response to a braking request, and the braking control unit When the slip rate of one of the left and right wheels is greater than or equal to the slip rate determination value under a situation in which braking force is generated on the left and right wheels by executing a braking process, A first reduction process for driving the electric motor corresponding to the wheel to reduce the pressing force on the rotating body that rotates integrally with the wheel with the lower slip rate, and the wheel with the higher slip rate. An anti-lock control unit that executes anti-lock control including a second reduction process for driving the electric motor corresponding to the wheel to reduce the pressing force on the rotating body that rotates. It is equipped with a. In the antilock control, the antilock control unit starts execution of the first reduction process, and then starts execution of the second reduction process.

  According to the above configuration, the execution of the second reduction process is started after the execution of the first reduction process is started and the reduction of the braking force generated at the wheel having the lower slip ratio is started. Therefore, of the left and right wheels, the time when the inrush current generated at the start of the electric motor corresponding to one wheel reaches the peak value, and the inrush current generated at the start of the electric motor corresponding to the other wheel reaches the peak value. Overlapping with the time to reach can be suppressed. Accordingly, it is possible to suppress a large load from being applied to the power source of the electric motor when each electric braking mechanism is operated along with the execution of the antilock control.

  By the way, when the slip ratio of one wheel becomes equal to or higher than the slip ratio judgment value, that is, when deceleration slip occurs in one wheel, the yaw moment resulting from the difference in braking force generated in the left and right wheels is In addition, the vehicle is easily deflected. In the above configuration, when the anti-lock control is started when the slip ratio of one wheel becomes equal to or higher than the slip ratio determination value, first, the first decrease that decreases the pressing force against the rotating body of the wheel having the lower slip ratio. Execution of the process is started, and thereafter, execution of a second reduction process for reducing the pressing force on the rotating body of the wheel having the higher slip rate is started. The braking force generated at the wheel with the lower slip rate is larger than the braking force generated at the wheel with the higher slip rate. In other words, in the above configuration, after the difference between the braking forces generated on the left and right wheels is reduced, the braking force generated on the wheels having the smaller braking force generated can be started to decrease. . Accordingly, when the braking force generated on the left and right wheels is reduced, it is possible to suppress an increase in the yaw moment due to the difference between the braking forces generated on the left and right wheels.

Therefore, according to the above configuration, it is possible to suppress overlapping of the time when the inrush current reaches the peak value while stabilizing the behavior of the vehicle.
In the vehicle brake device, the anti-lock control unit starts executing the second reduction process after a lapse of a specified time from the start of execution of the first reduction process. The prescribed time is preferably set to a time shorter than the period from the start to the end of the execution of the first reduction process.

  According to the above configuration, the execution of the second reduction process can be started while the braking force generated at the wheel having the lower slip ratio is being reduced by the execution of the first reduction process. Therefore, the time when the inrush current generated when starting the electric motor corresponding to one wheel reaches the peak value overlaps the time when the inrush current generated when starting the electric motor corresponding to the other wheel reaches the peak value. It is possible to suppress the start of execution of the second reduction process from being delayed excessively.

  Furthermore, when the first braking process is executed, the vehicular braking device has a larger current value for driving the electric motor corresponding to the wheel to be subjected to the first reducing process. It can also comprise so that the time setting part which lengthens the said regulation time may be provided.

  The time when the inrush current generated at the time of starting the electric motor reaches the peak value can be estimated based on the magnitude of the drive current that flows through the electric motor. Specifically, the peak value of the inrush current generated when the electric motor is started tends to increase as the drive current of the electric motor increases. As the peak value of the inrush current increases, the period from when the inrush current starts to reach the peak value becomes longer.

  Therefore, in the above configuration, the specified time from the start of the execution of the first reduction process to the start of the execution of the second reduction process is set longer as the current value for driving the electric motor is larger. Yes. Thereby, it is possible to suppress the overlap between the time when the inrush current generated by the execution of the first reduction process reaches the peak value and the time when the inrush current generated by the execution of the second reduction process reaches the peak value. Moreover, according to the said structure, regulation time becomes short, so that the electric current value which drives an electric motor is small. Therefore, when the inrush current generated by the execution of the first reduction process reaches the peak value early, the execution of the second reduction process can be started early.

  An example of the vehicle braking device includes a road surface determination unit that determines whether or not the road surface on which the vehicle is traveling is a split road surface. In the antilock control when the road surface determination unit determines that the road surface is a split road surface by the road surface determination unit, the antilock control unit starts execution of the first reduction process, and then the second decrease. Start executing the process. On the other hand, in the antilock control when the road surface determination unit determines that the road surface is not a split road surface, the execution of the second reduction process is started, and then the execution of the first reduction process is started. To do.

  According to the above configuration, when the road surface is a split road surface, the difference between the slip ratios of the left and right wheels tends to be large. Therefore, in anti-lock control, the braking force generated by the wheel with the lower slip ratio is reduced. It starts before the reduction of the braking force generated at the higher rate wheel. As a result, it is possible to suppress an increase in yaw moment due to a difference in braking force generated between the left and right wheels, and to suppress a decrease in the stability of the vehicle behavior.

  On the other hand, when the road surface is not a split road surface, the difference between the slip ratios of the left and right wheels is difficult to increase. Therefore, even if the difference in braking force generated between the left and right wheels at this time increases to some extent, the stability of the vehicle behavior is unlikely to decrease. Therefore, according to the above configuration, in the anti-lock control, the braking force generated on the wheel with the lower slip ratio starts decreasing after the braking force generated on the wheel with the higher slip ratio. That is, it is possible to delay the start of a decrease in braking force generated at the wheel having the larger braking force. Therefore, when the road surface is not a split road surface, it is possible to suppress a decrease in the deceleration of the vehicle.

  In an example of a vehicle braking device, the antilock control unit starts executing the first reduction process in the antilock control when the road surface determination unit determines that the road surface is a split road surface. After the first delay time has elapsed, execution of the second reduction process is started. On the other hand, in the anti-lock control when the road surface determination unit determines that the road surface is not a split road surface, the first delay time elapses after the execution of the second reduction process is started. Start the decrease process. The first delay time is set to be shorter than the period from the start to the end of the first decrease process, and the second delay time is the period from the start to the end of the second decrease process. Is set shorter.

  According to the above configuration, when it is determined that the road surface is a split road surface, the second braking force is generated while the braking force generated on the wheel with the lower slip ratio is being reduced by the execution of the first reduction process. Can be started. On the other hand, when it is determined that the road surface is not a split road surface, the first reduction process is performed while the braking force generated on the wheel with the higher slip ratio is being reduced by the execution of the second reduction process. Execution can be started. As a result, the time when the inrush current generated when starting the electric motor corresponding to one wheel reaches the peak value and the time when the inrush current generated when starting the electric motor corresponding to the other wheel reaches the peak value overlap. While suppressing this, it is possible to suppress an excessive delay in the start of the reduction process to be executed later among the first reduction process and the second reduction process.

  In an example of a vehicle braking device, the antilock control unit includes the first reduction process and the second reduction in the antilock control when the road surface determination unit determines that the road surface is not a split road surface. After reducing the left and right braking forces by executing the reduction process, the wheels are set to increase the pressing force on the rotating body that rotates integrally with the wheel that is the execution target of the first reduction process among the left and right wheels. The first pressing process for driving the electric motor corresponding to is started, and then the pressing force against the rotating body that rotates integrally with the wheel that is the execution target of the second decreasing process among the left and right wheels The second increase process for driving the electric motor corresponding to the wheel is started. On the other hand, in the antilock control when the road surface determination unit determines that the road surface is a split road surface, the left and right braking forces are decreased by executing the first reduction process and the second reduction process. After that, the execution of the second increase process is started, and then the execution of the first increase process is started.

  According to the above configuration, after the braking force generated on the left and right wheels is decreased by executing the first decrease process and the second decrease process, the first increase process and the second increase process are performed in order to decelerate the vehicle. By executing the increasing process, the braking force generated at the left and right wheels is increased. Even when the braking force generated on the left and right wheels is increased in this way, one of the first increasing process and the second increasing process is started first, and then the other is started. Therefore, the time when the inrush current generated when starting the electric motor corresponding to one wheel reaches the peak value overlaps the time when the inrush current generated when starting the electric motor corresponding to the other wheel reaches the peak value. Can be suppressed. Thereby, even when the braking force for the left and right wheels is increased by the anti-lock control, it is possible to suppress a large load from being applied to the power source of the electric motor.

  Further, in the above configuration, when it is determined that the road surface is not a split road surface, the slip ratio of the wheel that is the target of the first reduction process, that is, one of the wheels is equal to or higher than the slip ratio determination value. The increase in braking force generated on the wheel with the lower slip rate (hereinafter referred to as “previous non-slip wheel”) is the wheel on which the second reduction process is executed, that is, the slip rate of one wheel slips. This is started before an increase in braking force generated on a wheel having a lower slip ratio (hereinafter referred to as “previous slip wheel”) when the ratio determination value is exceeded. In other words, the braking force generated at the wheel where deceleration slip is difficult to occur even when the braking force is increased is increased first. As a result, it is possible to lengthen the period from the start of the increasing process until the slip rate of one of the left and right wheels again rises above the slip ratio determination value, that is, the decreasing process is executed again. Can be delayed. Therefore, the deceleration of the vehicle during the antilock control can be increased.

  Here, when the road surface on which the vehicle is traveling is a split road surface, when the braking force generated by the previous slip wheel is increased, the slip ratio of the previous slip wheel tends to increase again. Therefore, when the vehicle is traveling on a split road surface, if the increase in the braking force generated in the previous non-slip wheel is started before the increase in the braking force generated in the previous slip wheel, The difference in braking force increases, and the yaw moment resulting from the difference increases. That is, the vehicle may be deflected.

  Therefore, in the above configuration, when it is determined that the road surface is a split road surface, the increase in the braking force generated in the previous slip wheel is started before the increase in the braking force generated in the previous non-slip wheel. . As a result, it is possible to advance the time when the slip ratio of the non-slip wheel is equal to or greater than the slip ratio determination value, and before the difference in braking force generated between the left and right wheels becomes large, the first reduction process and the second Can be started. Therefore, it is possible to suppress a decrease in the stability of the vehicle behavior during the antilock control.

The block diagram which shows the outline of the braking device which is one Embodiment of the braking device for vehicles. The figure which shows the cross-section of the electric braking mechanism with which the braking device is provided, and a braking control apparatus. The flowchart explaining the processing routine which the brake control apparatus performs. The flowchart explaining the processing routine which the brake control apparatus performs. The flowchart explaining the processing routine which the brake control apparatus performs. The flowchart explaining the processing routine which the brake control apparatus performs. The flowchart explaining the processing routine which the brake control apparatus performs. The flowchart explaining the processing routine which the brake control apparatus performs. The flowchart explaining the processing routine which the brake control apparatus performs. The timing chart which shows transition of the electric current value which flows into the electric motor of the electric braking mechanism. The timing chart which shows transition of the electric current value which flows into the electric motor of the electric braking mechanism. The block diagram which shows the function structure of the control apparatus with which the braking device for vehicles of the example of a change is provided. The figure explaining the electric current value which flows into the electric motor of the electric braking mechanism with which the braking device for vehicles of the example of a change is provided.

Hereinafter, an embodiment of a vehicle braking device will be described with reference to FIGS.
FIG. 1 shows a braking device 10 as a vehicle braking device of this embodiment and a service braking device 20. As shown in FIG. 1, the braking device 10 includes a parking braking device 30 and a braking control device 11 that controls the operation of the parking braking device 30. Electric braking mechanisms 31L and 31R constituting the parking brake device 30 are provided for the left and right rear wheels RL and RR, respectively. A braking mechanism is provided for each of the left and right front wheels.

  The electric braking mechanisms 31L, 31R and the braking mechanism for the front wheels include a rotating body 22 that rotates integrally with the wheels, a pair of friction members 23A, 23B disposed on both sides of the rotating body 22 in the vehicle width direction, and a wheel cylinder 25. Each is equipped. Then, by increasing the hydraulic pressure in the wheel cylinder 25, the pressing force that is the force pressing the friction materials 23A and 23B against the rotating body 22, that is, the pressing force on the rotating body 22 increases. As a result, a braking force corresponding to the pressing force is generated between the wheel and the road surface. In the present embodiment, the braking force generated between the wheel and the road surface is referred to as “braking force generated at the wheel”.

  The service braking device 20 includes a hydraulic pressure generating device 21 to which a brake pedal 91 is drivingly connected, and a braking actuator 28 disposed between the hydraulic pressure generating device 21 and each wheel cylinder 25. When the brake pedal 91 is operated by the driver of the vehicle, an amount of brake fluid corresponding to the operation amount of the brake pedal 91 is supplied from the hydraulic pressure generator 21 into each wheel cylinder 25. The brake actuator 28 is operated so as to generate a differential pressure between the master chamber 21 </ b> A provided in the hydraulic pressure generator 21 and the wheel cylinder 25.

  As shown in FIG. 2, the electric braking mechanisms 31L and 31R are provided with calipers 24 that support the friction materials 23A and 23B in a state in which the electric braking mechanisms 31L and 31R are relatively movable in a direction approaching the rotating body 22 and a direction away from the rotating body 22. Yes. Of the friction materials 23A and 23B, the friction material 23A is located on the inner side in the vehicle width direction than the rotating body 22. A wheel cylinder 25 is provided in the caliper 24 on the inner side in the vehicle width direction than the friction material 23A. The wheel cylinder 25 has a bottomed substantially cylindrical shape in which the inner side in the vehicle width direction is closed by the bottom 25A and the outer side in the vehicle width direction opens. The opening of the wheel cylinder 25 is closed by a piston 27, and a cylinder chamber 26 is defined by the wheel cylinder 25 and the piston 27. The piston 27 has a substantially bottomed cylindrical shape whose outer side in the vehicle width direction is closed and whose inner side in the vehicle width direction is open, and can slide in the wheel width direction in the wheel cylinder 25. A friction material 23 </ b> A is disposed at an end of the piston 27 on the outer side in the vehicle width direction.

  Brake fluid is supplied to the cylinder chamber 26 of the wheel cylinder 25 from the service braking device 20. The brake fluid is supplied, the hydraulic pressure in the cylinder chamber 26 increases, and the piston 27 slides so as to transition to the outside in the vehicle width direction on the left side in the drawing. Then, the friction materials 23 </ b> A and 23 </ b> B approach the rotating body 22 and the friction materials 23 </ b> A and 23 </ b> B are pressed against the rotating body 22. On the other hand, when the hydraulic pressure in the cylinder chamber 26 decreases and the piston 27 slides so as to make a transition to the inside in the vehicle width direction, which is the right side in the figure, the pressing of the friction materials 23A and 23B by the piston 27 is eliminated, and the friction material 23A. , 23B are separated from the rotating body 22.

  The electric braking mechanisms 31L and 31R are provided with an electric motor 33 that can rotate the output shaft 34 in both forward and reverse directions. The electric motor 33 is connected to a power source 32 that is a drive source. Examples of the power source 32 include a vehicle battery. The electric braking mechanisms 31L and 31R are disposed so as to mesh with the first gear 35 and the first gear 35 fixed to the output shaft 34 of the electric motor 33 extending in the vehicle width direction. 2 has a gear 36 and a rod member 37 disposed in parallel with the output shaft 34. The gears 35 and 36 are disposed outside the wheel cylinder 25, respectively. The rod member 37 penetrates the bottom portion 25A of the wheel cylinder 25 in the vehicle width direction and is supported by the bottom portion 25A in a rotatable state. And the 2nd gear 36 is being fixed to the part located in the outer side of the wheel cylinder 25 among the rod members 37 so that integral rotation is possible. The first gear 35 and the second gear 36 are each configured to decelerate the rotational speed of the output shaft 34 of the electric motor 33 and output it to the rod member 37.

  A nut 38 is attached to an end portion of the rod member 37 on the inner side in the vehicle width direction, that is, an end portion of the rod member 37 located in the cylinder chamber 26. The nut 38 is disposed in the cylinder chamber 26, more specifically, inside the piston 27. The inner peripheral surface of the nut 38 is internally threaded. Further, the peripheral surface of a portion of the rod member 37 located in the wheel cylinder 25 is subjected to male screw processing, and the nut 38 is screwed to the rod member 37. Therefore, when the rod member 37 is rotated by the drive of the electric motor 33, the nut 38 moves to one side or the other side in the vehicle width direction. That is, the rotary motion of the electric motor 33 is converted into a linear motion by the rod member 37 and the nut 38 and transmitted to the piston 27. Then, by the operation of the electric braking mechanisms 31L and 31R resulting from the driving of the electric motor 33, a pressing force which is a force for pressing the friction material 23A against the rotating body 22 is generated, and between the rear wheels RL and RR and the road surface. A braking force can be generated.

Next, the braking control device 11 will be described with reference to FIGS. 1 and 2.
The brake control device 11 is electrically connected to four wheel speed sensors 101 to 104 corresponding to the respective wheels of the vehicle (the left and right rear wheels RL and RR and the left and right front wheels). The wheel speed sensors 101 and 102 output signals corresponding to the wheel speeds VWL and VWR, which are rotational angular velocities of the corresponding rear wheels RL and RR, to the braking control device 11. The wheel speed sensors 103 and 104 output a signal corresponding to the wheel speed, which is the rotational angular speed of the corresponding left and right front wheels, to the braking control device 11.

  An operation amount sensor 92 that detects an operation amount of the brake pedal 91 and an operation unit 93 provided in the passenger compartment are electrically connected to the brake control device 11. The operation unit 93 is turned on when the braking force is generated by the rear wheels RL and RR by the operation of the parking brake device 30, while the braking force is generated by the rear wheels RL and RR by the operation of the parking brake device 30. It is turned off when releasing the state. The operation unit 93 outputs an on operation signal to the braking control device 11 when the on operation is performed, and outputs an off operation signal to the braking control device 11 when the operation unit 93 is operated off.

The brake control device 11 is electrically connected to a yaw rate sensor 105 that detects a yaw rate Yr, which is a changing speed of the rotation angle in the turning direction of the vehicle.
The braking control device 11 includes a braking control unit 12, an antilock control unit 13, a road surface determination unit 14, and a wheel monitoring unit 15 as functional units.

  When an ON operation signal is input from the operation unit 93, the braking control unit 12 performs a parking braking process in which the electric braking mechanisms 31L and 31R are operated to generate a braking force on the rear wheels RL and RR. That is, the input of an ON operation signal from the operation unit 93 corresponds to “braking request”. On the other hand, when an off operation signal is input from the operation unit 93, the braking control unit 12 operates the electric braking mechanisms 31L and 31R to cancel the state in which the braking force is generated in the rear wheels RL and RR. The parking brake release process is executed. The brake control unit 12 determines the amount of operation of the brake pedal 91 when an abnormality has occurred in the service braking device 20 and there is a possibility that brake fluid cannot be supplied into the wheel cylinders 25 for the rear wheels RL and RR. Based on this, the electric braking mechanisms 31L and 31R may be operated to generate a braking force on the rear wheels RL and RR. Thus, when abnormality has occurred in the service braking device 20, operating the brake pedal 91 corresponds to the “braking request”.

  The antilock control unit 13 executes antilock control and spin return control described later. In the anti-lock control and the spin return control, the electric braking mechanisms 31L and 31R are operated to reduce the pressing force to the rotating body 22 that rotates integrally with the rear wheels RL and RR, and increase the pressing force. This is control for repeatedly executing the pressing force increasing process.

  The antilock control unit 13 stores a first delay time PTI, a second delay time PT2, and an increase delay time PTI used for antilock control and spin recovery control described later.

  The wheel monitoring unit 15 calculates the vehicle body speed based on the wheel speed of each wheel detected from the wheel speed sensors 101 to 104. For example, the wheel monitoring unit 15 can set the largest value of the wheel speeds of the wheels as the vehicle body speed. The wheel monitoring unit 15 calculates and stores the slip ratio (= (vehicle speed−wheel speed) / vehicle speed) of each wheel based on the wheel speed and the vehicle speed.

  The road surface determination unit 14 determines whether or not the road surface on which the vehicle is traveling is a split road surface based on the slip ratio SLPL of the left rear wheel RL and the slip ratio SLPR of the right rear wheel RR. The split road surface is a road surface in which the difference between the friction coefficient of the road surface on which the right wheel of the vehicle contacts and the friction coefficient of the road surface on which the left wheel of the vehicle contacts is large. Specifically, the road surface determination unit 14 determines that the slip ratio difference ΔSLP, which is the absolute value of the difference between the slip ratio SLPL and the slip ratio SLPR, is in a state where braking force is generated on the left and right rear wheels RL and RR. When the road surface determination value ΔSLPA is larger, it is determined that the vehicle is traveling on the split road surface. That is, when the slip ratios of the left and right wheels are greatly different, it is determined that the road surface being traveled is a split road surface. The accuracy of the determination of whether or not the road surface is a split road surface is the difference between the pressing force applied to the rotating body 22 rotating integrally with the left rear wheel RL and the pressing force applied to the rotating body 22 rotating integrally with the right rear wheel RR. Smaller is higher.

  Next, with reference to FIG. 3, a processing routine executed by the braking control device 11 for executing the pre-determination process executed prior to the antilock control or the spin return control will be described. This processing routine is executed when a braking force is generated in each rear wheel RL, RR by executing the parking braking process.

  As shown in FIG. 3, when this processing routine is executed, first, in step S11, it is determined whether or not the wheel speed can be detected by each wheel speed sensor 101-104. When an abnormality occurs in the wheel speed sensors 101 to 104 or a signal line connecting the wheel speed sensors 101 to 104 and the braking control device 11 is disconnected, a signal is input to the braking control device 11 from the wheel speed sensors 101 to 104. It will not be done. When the signal is not input in this way, the braking control device 11 cannot calculate the wheel speed and the vehicle body speed, that is, cannot calculate the slip ratios SLPL and SLPR. Therefore, when the wheel speed cannot be detected (S11: NO), the process proceeds to step S12. In step S12, the spin return control execution flag is set to ON. This spin return control execution flag is set to ON when prohibiting execution of antilock control, which will be described later, and permitting execution of spin return control. Thereafter, this processing routine is terminated. On the other hand, when the wheel speed can be detected (S11: YES), the process proceeds to step S13.

  In step S13, the road surface determination unit 14 determines whether or not the road surface on which the vehicle is traveling is a split road surface. If it is determined that the road surface is not a split road surface (S13: NO), the process proceeds to step S14. In step S14, ON is set to the uniform road surface flag. The uniform road surface flag is set to ON when the anti-lock control is permitted to be executed in a situation where the road surface on which the vehicle is traveling is not a split road surface, that is, in a situation where the road surface is a uniform road surface. Thereafter, this processing routine is terminated. The uniform road surface is a road surface in which the difference between the friction coefficient of the road surface on which the right wheel of the vehicle contacts and the friction coefficient of the road surface on which the left wheel of the vehicle contacts is small.

  On the other hand, when it determines with it being a split road surface in step S13 (S13: YES), a process is transfered to step S15. In step S15, the split road surface flag is set to ON. The split road surface flag is set to ON when the anti-lock control is permitted to be executed under a situation where the road surface on which the vehicle travels is a split road surface. Thereafter, this processing routine is terminated.

The spin return control execution flag, the uniform road surface flag, and the split road surface flag are turned off, for example, when the vehicle stops.
Next, a processing routine executed by the braking control device 11 in order to execute antilock control while traveling on a split road surface will be described with reference to FIGS. 4 and 5. These processing routines are executed by the antilock control unit 13.

  First, the processing routine of FIG. 4 will be described. This processing routine is repeatedly executed every predetermined control cycle while an after-mentioned reduction processing execution flag is set to OFF.

  As shown in FIG. 4, when this processing routine is executed, first, in step S101, it is determined whether or not the split road surface flag is set to ON. When the split road surface flag is not set to ON (S101: NO), this processing routine is temporarily ended. On the other hand, when the split road surface flag is set to ON (S101: YES), the process proceeds to step S102. In step S102, it is determined whether or not the slip ratio SLPL of the left rear wheel RL or the slip ratio SLPR of the right rear wheel RR is greater than or equal to the slip determination value KVS. The slip determination value KVS is set as a determination criterion for determining whether or not the wheel has a tendency to lock. For example, the slip determination value KVS may be the same value as a determination value serving as a determination criterion as to whether or not the wheel exhibits a locking tendency when the anti-lock brake control for operating the braking actuator 28 is executed. The value may be smaller than the determination value.

  When both the slip ratio SLPL of the left rear wheel RL and the slip ratio SLPR of the right rear wheel RR are lower than the slip determination value KVS (S102: NO), this processing routine is temporarily ended. On the other hand, if either the slip ratio SLPL of the left rear wheel RL or the slip ratio SLPR of the right rear wheel RR is equal to or greater than the slip determination value KVS (S102: YES), the process proceeds to step S103.

  In step S103, it is determined whether or not the slip ratio SLPR of the right rear wheel RR is greater than or equal to the slip ratio SLPL of the left rear wheel RL. That is, it is determined which of the slip rate SLPR and the slip rate SLPL is higher. When the slip rate SLPR is lower than the slip rate SLPL (S103: NO), the process proceeds to step S104. In step S104, the execution of the pressing force reduction process for the right rear wheel RR that drives the electric motor 33 of the electric braking mechanism 31R to reduce the pressing force on the rotating body 22 that rotates integrally with the right rear wheel RR is started. Goes to step S105. In step S105, it is determined whether or not the first delay time PT1 has elapsed since the execution of the pressing force reduction process for the right rear wheel RR was started. When the first delay time PT1 has not elapsed (S105: NO), the process of step S105 is repeatedly executed. On the other hand, when the first delay time PT1 has elapsed (S105: YES), the process proceeds to step S106. In step S106, execution of the pressing force reduction process for the left rear wheel RL for driving the electric motor 33 of the electric braking mechanism 31L is started to reduce the pressing force on the rotating body 22 that rotates integrally with the left rear wheel RL. Is shifted to step S110.

  On the other hand, if the slip rate SLPR is equal to or greater than the slip rate SLPL in step S103 (S103: YES), the process proceeds to step S107. In step S107, execution of the pressing force reduction process for the left rear wheel RL that drives the electric motor 33 of the electric braking mechanism 31L is started to reduce the pressing force on the rotating body 22 that rotates integrally with the left rear wheel RL. Is transferred to step S108. In step S108, it is determined whether or not the first delay time PT1 has elapsed since the execution of the pressing force reduction process for the left rear wheel RL was started. If the first delay time PT1 has not elapsed (S108: NO), the process of step S108 is repeatedly executed. On the other hand, when the first delay time PT1 has elapsed (S108: YES), the process proceeds to step S109. In step S109, execution of a pressing force reduction process for the right rear wheel RR that drives the electric motor 33 of the electric braking mechanism 31R is started to reduce the pressing force on the rotating body 22 that rotates integrally with the right rear wheel RR. Is shifted to step S110.

  In step S110, it is determined whether or not driving of the electric motor 33 of each of the electric braking mechanisms 31L and 31R is stopped. The execution of the pressing force reduction process, that is, the driving of the electric motor 33 is continued until the termination condition of the pressing force reduction process is satisfied. Therefore, when the end condition has not yet been established at least one of the both electric braking mechanisms 31L and 31R (S110: NO), the process of step S110 is repeatedly executed. On the other hand, when the termination condition is satisfied in both the electric braking mechanisms 31L and 31R (S110: YES), the process proceeds to step S111. In the present embodiment, the termination condition of the pressing force reduction process is that the pressing force is not applied to the rotating body 22, that is, the friction materials 23 </ b> A and 23 </ b> B are separated from the rotating body 22.

In step S111, ON is set to the reduction process executed flag. Thereafter, this processing routine is once terminated.
In this processing routine, when the slip ratio SLPL is higher than the slip ratio SLPR, the left rear wheel RL corresponds to a rear wheel having a high slip ratio, and the right rear wheel RR corresponds to a rear wheel having a low slip ratio. Therefore, when the slip rate SLPL is higher than the slip rate SLPR, the pressing force reduction process for the right rear wheel RR, which is started in step S104, corresponds to the “first reduction process”, and is executed in step S106. The pressing force reduction process for the left rear wheel RL that is started corresponds to the “second reduction process”. On the other hand, when the slip ratio SLPR is higher than the slip ratio SLPL, the pressing force reduction process for the left rear wheel RL that is started in step S107 corresponds to the “first reduction process”, and is executed in step S109. The pressing force reduction process for the right rear wheel RR that is started corresponds to the “second reduction process”. That is, in the anti-lock control executed while traveling on the split road surface, when the braking force generated at each of the rear wheels RL and RR is reduced, the execution of the first reduction process is started, and then the second reduction process. The execution of is started.

  The first delay time PT1 is set to delay the activation of the electric motor 33 of the other electric braking mechanism relative to the activation of the electric motor 33 of one of the electric braking mechanisms 31L and 31R. Value. That is, the first delay time PT1 corresponds to a “specified time”. In the present embodiment, when the electric motor 33 is driven to reduce the pressing force on the rotating body 22, the generation period of the inrush current generated when the electric motor 33 is started is obtained in advance by experiments. The time length of the generation period is stored in the antilock control unit 13 as the first delay time PT1. The first delay time PT1 is shorter than the time from the start of execution of the “first decrease process” to the end of execution.

Next, the processing routine of FIG. 5 will be described. This processing routine is repeatedly executed every predetermined control cycle while the processing routine of FIG. 4 is not executed.
As shown in FIG. 5, when this processing routine is executed, it is first determined in step S121 whether or not the split road surface flag is set to ON. When the split road surface flag is not set to ON (S121: NO), this processing routine is temporarily ended. On the other hand, when the split road surface flag is set to ON (S121: YES), the process proceeds to step S122. In step S122, it is determined whether or not the reduction process execution completion flag is set to ON. When the decrease process execution flag is not set to ON (S122: NO), this process routine is temporarily ended. On the other hand, when ON is set to the reduction process execution completion flag (S122: YES), the process proceeds to step S123.

  Here, in the previous execution of the processing routine shown in FIG. 4 executed to reduce the braking force generated on the left and right rear wheels RL, RR, the slip of the left rear wheel RL used in the determination in step S103. The rate SLPL is referred to as “previous slip rate SLPL of the left rear wheel RL”, and the slip rate SLPR of the right rear wheel RR used in the determination in step S103 is referred to as “previous slip rate SLPR of the right rear wheel RR”. To do.

  In step S123, it is determined whether or not the previous slip rate SLPR of the right rear wheel RR is greater than or equal to the previous slip rate SLPL of the left rear wheel RL. That is, it is determined which of the previous slip rate SLPR and the previous slip rate SLPL is higher. If the previous slip rate SLPR is lower than the previous slip rate SLPL (S123: NO), the process proceeds to step S124. In step S124, execution of the pressing force increasing process for the left rear wheel RL for driving the electric motor 33 of the electric braking mechanism 31L is started to increase the pressing force on the rotating body 22 that rotates integrally with the left rear wheel RL. Is shifted to step S125. In step S125, it is determined whether or not an increase delay time PTI has elapsed since the execution of the pressing force increasing process for the left rear wheel RL was started. When the increase delay time PTI has not elapsed (S125: NO), the process of step S125 is repeatedly executed. On the other hand, when the increase delay time PTI has elapsed (S125: YES), the process proceeds to step S126. In step S126, execution of the pressing force increasing process for the right rear wheel RR for driving the electric motor 33 of the electric braking mechanism 31R is started to increase the pressing force on the rotating body 22 that rotates integrally with the right rear wheel RR. Is shifted to step S130.

  On the other hand, in step S123, when the previous slip rate SLPR is equal to or higher than the previous slip rate SLPL (S123: YES), the process proceeds to step S127. In step S127, execution of the pressing force increasing process for the right rear wheel RR for driving the electric motor 33 of the electric braking mechanism 31R is started to increase the pressing force on the rotating body 22 that rotates integrally with the right rear wheel RR. Goes to step S128. In step S128, it is determined whether or not an increase delay time PTI has elapsed since the execution of the pressing force increasing process for the right rear wheel RR was started. When the increase delay time PTI has not elapsed (S128: NO), the process of step S128 is repeatedly executed. On the other hand, when the increase delay time PTI has elapsed (S128: YES), the process proceeds to step S129. In step S129, execution of the pressing force increasing process for the left rear wheel RL for driving the electric motor 33 of the electric braking mechanism 31L is started to increase the pressing force on the rotating body 22 that rotates integrally with the left rear wheel RL. Is shifted to step S130.

In step S130, OFF is set to the reduction process execution completion flag. Thereafter, this processing routine is once terminated.
In this processing routine, when the previous slip rate SLPL is higher than the previous slip rate SLPR, the left rear wheel RL corresponds to the rear wheel to be subjected to the second reduction process, and the right rear wheel RR is the first rear wheel RR. This corresponds to the rear wheel that is the execution target of the reduction process 1. Therefore, when the previous slip ratio SLPL is higher than the previous slip ratio SLPR, the pressing force increasing process for the left rear wheel RL that is started in step S124 corresponds to the “second increasing process”. The pressing force increasing process for the right rear wheel RR that is started in S126 corresponds to the “first increasing process”. On the other hand, when the previous slip ratio SLPR is higher than the previous slip ratio SLPL, the left rear wheel RL corresponds to the rear wheel on which the first reduction process is executed, and the right rear wheel RR is the second reduction process. It corresponds to the rear wheel that is the execution target of. Therefore, when the previous slip ratio SLPR is higher than the previous slip ratio SLPL, the pressing force increasing process for the right rear wheel RR that is started in step S127 corresponds to the “second increasing process”. The pressing force increasing process for the left rear wheel RL, which is started in S129, corresponds to the “first increasing process”. That is, in the anti-lock control executed while traveling on the split road surface, when the braking force generated at each rear wheel RL, RR is increased, the execution of the second increasing process is started, and then the first increasing process is performed. The execution of is started.

  The increase delay time PTI is set in order to delay the start of the electric motor 33 of the other electric brake mechanism with respect to the start of the electric motor 33 of one of the electric brake mechanisms 31L and 31R. Value. In the present embodiment, when the electric motor 33 is driven to increase the pressing force on the rotating body 22, the generation period of the inrush current generated when the electric motor 33 is started is obtained in advance by experiments. The time length of the generation period is stored in the antilock control unit 13 as an increase delay time PTI. The increase delay time PTI is shorter than the time from the start of execution of the “second increase process” to the end of execution.

  Next, referring to FIG. 6 and FIG. 7, when the vehicle is traveling on a uniform road surface, that is, in order to perform antilock control while traveling on a road surface that is not a split road surface, processing executed by the braking control device 11 The routine will be described. These processing routines are executed by the antilock control unit 13.

  First, the processing routine of FIG. 6 will be described. This processing routine is repeatedly executed every predetermined control cycle while an after-mentioned reduction processing execution flag is set to OFF.

  As shown in FIG. 6, when this processing routine is executed, first, in step S201, it is determined whether or not the uniform road surface flag is set to ON. When the uniform road surface flag is not set to ON (S201: NO), this processing routine is temporarily ended. On the other hand, if the uniform road surface flag is set to ON (S201: YES), the process proceeds to step S202. In step S202, it is determined whether or not the slip ratio SLPL of the left rear wheel RL or the slip ratio SLPR of the right rear wheel RR is greater than or equal to the slip determination value KVS.

  When both the slip ratio SLPL of the left rear wheel RL and the slip ratio SLPR of the right rear wheel RR are lower than the slip determination value KVS (S202: NO), this processing routine is temporarily ended. On the other hand, if either the slip ratio SLPL of the left rear wheel RL or the slip ratio SLPR of the right rear wheel RR is equal to or greater than the slip determination value KVS (S202: YES), the process proceeds to step S203.

  In step S203, it is determined whether or not the slip ratio SLPR of the right rear wheel RR is greater than or equal to the slip ratio SLPL of the left rear wheel RL. That is, it is determined which of the slip rate SLPR and the slip rate SLPL is higher. If the slip rate SLPR is lower than the slip rate SLPL (S203: NO), the process proceeds to step S204. In step S204, execution of the pressing force reduction process for the left rear wheel RL that drives the electric motor 33 of the electric braking mechanism 31L is started to reduce the pressing force on the rotating body 22 that rotates integrally with the left rear wheel RL. Is transferred to step S205. In step S205, it is determined whether or not the second delay time PT2 has elapsed since the execution of the pressing force reduction process for the left rear wheel RL was started. When the second delay time PT2 has not elapsed (S205: NO), the process of step S205 is repeatedly executed. On the other hand, when the second delay time PT2 has elapsed (S205: YES), the process proceeds to step S206. In step S206, execution of a pressing force reduction process for the right rear wheel RR for driving the electric motor 33 of the electric braking mechanism 31R is started in order to reduce the pressing force on the rotating body 22 that rotates integrally with the right rear wheel RR. Goes to step S210.

  On the other hand, in step S203, when the slip ratio SLPR is equal to or greater than the slip ratio SLPL (S203: YES), the process proceeds to step S207. In step S207, execution of a pressing force reduction process for the right rear wheel RR for driving the electric motor 33 of the electric braking mechanism 31R is started to reduce the pressing force on the rotating body 22 that rotates integrally with the right rear wheel RR. Goes to step S208. In step S208, it is determined whether or not the second delay time PT2 has elapsed since the execution of the pressing force reduction process for the right rear wheel RR was started. When the second delay time PT2 has not elapsed (S208: NO), the process of step S208 is repeatedly executed. On the other hand, when the second delay time PT2 has elapsed (S208: YES), the process proceeds to step S209. In step S209, execution of the pressing force reduction process for the left rear wheel RL for driving the electric motor 33 of the electric braking mechanism 31L is started to reduce the pressing force on the rotating body 22 that rotates integrally with the left rear wheel RL. Goes to step S210.

  In step S210, it is determined whether or not driving of the electric motor 33 of each of the electric braking mechanisms 31L and 31R is stopped. Execution of the pressing force reduction process, that is, driving of the electric motor 33 is continued until the termination condition of the pressing force reduction process is satisfied. Therefore, when the termination condition has not yet been established in at least one of the both electric braking mechanisms 31L and 31R (S210: NO), the process of step S210 is repeatedly executed. On the other hand, when the termination condition is satisfied in both the electric braking mechanisms 31L and 31R (S210: YES), the process proceeds to step S211.

In step S211, ON is set to the reduction process executed flag. Thereafter, this processing routine is once terminated.
In this processing routine, when the slip ratio SLPL is higher than the slip ratio SLPR, the left rear wheel RL corresponds to a rear wheel having a high slip ratio, and the right rear wheel RR corresponds to a rear wheel having a low slip ratio. Therefore, when the slip rate SLPL is higher than the slip rate SLPR, the pressing force reduction process for the left rear wheel RL, which is started in step S204, corresponds to the “second reduction process”, and is executed in step S206. The pressing force reduction process for the right rear wheel RR that is started corresponds to the “first reduction process”. On the other hand, when the slip ratio SLPR is higher than the slip ratio SLPL, the pressing force reduction process for the right rear wheel RR, which is started in step S207, corresponds to the “second reduction process” and is executed in step S209. The pressing force reduction process for the left rear wheel RL that is started corresponds to the “first reduction process”. That is, in the anti-lock control executed while traveling on the uniform road surface, when the braking force generated at each rear wheel RL, RR is reduced, the execution of the second reduction process is started, and then the first reduction process is performed. The execution of is started.

  The second delay time PT2 is set to delay the activation of the electric motor 33 of the other electric braking mechanism relative to the activation of the electric motor 33 of one of the electric braking mechanisms 31L and 31R. Value. In the present embodiment, when the electric motor 33 is driven to reduce the pressing force on the rotating body 22, the generation period of the inrush current generated when the electric motor 33 is started is obtained in advance by experiments. The time length of the generation period is stored in the antilock control unit 13 as the second delay time PT2. The second delay time PT2 is shorter than the time from the start to the end of execution of the “second decrease process”.

Next, the processing routine of FIG. 7 will be described. This processing routine is repeatedly executed every predetermined control cycle while the processing routine of FIG. 6 is not executed.
As shown in FIG. 7, when this processing routine is executed, it is first determined in step S221 whether or not the uniform road surface flag is set to ON. If the uniform road surface flag is not set to ON (S221: NO), this processing routine is temporarily ended. On the other hand, if the uniform road surface flag is set to ON (S221: YES), the process proceeds to step S222. In step S222, it is determined whether or not the reduction process execution completion flag is set to ON. When ON is not set to the reduction process execution completion flag (S222: NO), this process routine is once ended. On the other hand, when the reduction process execution flag is set to ON (S222: YES), the process proceeds to step S223.

  Here, the slip of the left rear wheel RL used in the determination of step S203 in the previous execution of the processing routine shown in FIG. 6 executed to reduce the braking force generated on the left and right rear wheels RL, RR. The rate SLPL is referred to as “previous slip rate SLPL of the left rear wheel RL”, and the slip rate SLPR of the right rear wheel RR used in the determination in step S203 is referred to as “previous slip rate SLPR of the right rear wheel RR”. To do.

  In step S223, it is determined whether or not the previous slip rate SLPR of the right rear wheel RR is greater than or equal to the previous slip rate SLPL of the left rear wheel RL. That is, it is determined which of the previous slip rate SLPR and the previous slip rate SLPL is higher. If the previous slip rate SLPR is lower than the previous slip rate SLPL (S223: NO), the process proceeds to step S224. In step S224, execution of the pressing force increasing process for the right rear wheel RR for driving the electric motor 33 of the electric braking mechanism 31R is started to increase the pressing force on the rotating body 22 that rotates integrally with the right rear wheel RR. Is shifted to step S225. In step S225, it is determined whether or not an increase delay time PTI has elapsed since the execution of the pressing force increasing process for the right rear wheel RR was started. When the increase delay time PTI has not elapsed (S225: NO), the process of step S225 is repeatedly executed. On the other hand, when the increase delay time PTI has elapsed (S225: YES), the process proceeds to step S226. In step S226, execution of the pressing force increasing process for the left rear wheel RL for driving the electric motor 33 of the electric braking mechanism 31L is started to increase the pressing force on the rotating body 22 that rotates integrally with the left rear wheel RL. Goes to step S230.

  On the other hand, if the previous slip rate SLPR is equal to or greater than the previous slip rate SLPL in step S223 (S223: YES), the process proceeds to step S227. In step S227, execution of the pressing force increasing process for the left rear wheel RL for driving the electric motor 33 of the electric braking mechanism 31L is started to increase the pressing force on the rotating body 22 that rotates integrally with the left rear wheel RL. Goes to step S228. In step S228, it is determined whether or not an increase delay time PTI has elapsed since the execution of the pressing force increasing process for the left rear wheel RL was started. When the increase delay time PTI has not elapsed (S228: NO), the process of step S228 is repeatedly executed. On the other hand, when the increase delay time PTI has elapsed (S228: YES), the process proceeds to step S229. In step S229, execution of the pressing force increasing process for the right rear wheel RR for driving the electric motor 33 of the electric braking mechanism 31R is started to increase the pressing force on the rotating body 22 that rotates integrally with the right rear wheel RR. Goes to step S230.

In step S230, the reduction process execution completion flag is set to OFF. Thereafter, this processing routine is once terminated.
In this processing routine, when the previous slip rate SLPL is higher than the previous slip rate SLPR, the left rear wheel RL corresponds to the rear wheel to be subjected to the second reduction process, and the right rear wheel RR is the first rear wheel RR. This corresponds to the rear wheel that is the execution target of the reduction process 1. Therefore, when the previous slip ratio SLPL is higher than the previous slip ratio SLPR, the pressing force increasing process for the right rear wheel RR that is started in step S224 corresponds to the “first increasing process”. The pressing force increasing process for the left rear wheel RL that is started in S226 corresponds to the “second increasing process”. On the other hand, when the previous slip ratio SLPR is higher than the previous slip ratio SLPL, the left rear wheel RL corresponds to the rear wheel on which the first reduction process is executed, and the right rear wheel RR is the second reduction process. It corresponds to the rear wheel that is the execution target of. Therefore, when the previous slip ratio SLPR is higher than the previous slip ratio SLPL, the pressing force increasing process for the left rear wheel RL that is started in step S227 corresponds to the “first increasing process”. The pressing force increasing process for the right rear wheel RR, which is started in S229, corresponds to a “second increasing process”. That is, in the anti-lock control executed while traveling on a uniform road surface, when the braking force generated at each rear wheel RL, RR is increased, the execution of the first increasing process is started, and then the second increasing process is performed. The execution of is started.

  The increase delay time PTI is set in order to delay the start of the electric motor 33 of the other electric brake mechanism with respect to the start of the electric motor 33 of one of the electric brake mechanisms 31L and 31R. Value. In the present embodiment, when the electric motor 33 is driven to increase the pressing force on the rotating body 22, the generation period of the inrush current generated when the electric motor 33 is started is obtained in advance by experiments. The time length of the generation period is stored in the antilock control unit 13 as an increase delay time PTI. The increase delay time PTI is shorter than the time from the start of execution of the “first increase process” to the end of execution.

  Next, with reference to FIG. 8 and FIG. 9, a processing routine executed by the braking control device 11 in order to execute the spin return control will be described. These processing routines are executed by the antilock control unit 13.

First, the processing routine of FIG. 8 will be described. This processing routine is repeatedly executed every predetermined control cycle.
As shown in FIG. 8, when this processing routine is executed, it is first determined in step S301 whether or not the spin return control execution flag is set to ON. If the spin return control execution flag is not set to ON (S301: NO), this processing routine is temporarily ended. On the other hand, if the spin return control execution flag is set to ON (S301: YES), the process proceeds to step S302. In step S302, it is determined whether or not the vehicle spin is detected based on the yaw rate Yr detected by the yaw rate sensor 105. When the yaw rate Yr is larger than the specified value, it is determined that the vehicle is spinning, and spin is detected. When the spin is not detected (S302: NO), this processing routine is once ended. On the other hand, if spin is detected (S302: YES), the process proceeds to step S303. If spin is detected, it is stored in the antilock control unit 13 as a spin history.

  In step S303, it is determined whether or not the direction of deflection of the spinning vehicle is right deflection. If it is not right deflection (S303: NO), the process proceeds to step S304. In step S304, execution of the pressing force reduction process for the left rear wheel RL for driving the electric motor 33 of the electric braking mechanism 31L is started to reduce the pressing force on the rotating body 22 that rotates integrally with the left rear wheel RL. Is shifted to step S305. In step S305, it is determined whether or not a standby end condition is satisfied. The standby end condition is that the deflection waiting time has elapsed after the execution of the pressing force reduction process for the left rear wheel RL is started, and the yaw rate after the execution of the pressing force reduction process for the left rear wheel RL is started. This includes both that the amount of change in Yr is greater than or equal to a predetermined amount of change. When the standby end condition is not satisfied (S305: NO), the process of step S305 is repeatedly executed. On the other hand, when the standby end condition is satisfied (S305: YES), the process proceeds to step S306. In step S306, execution of a pressing force reduction process for the right rear wheel RR that drives the electric motor 33 of the electric braking mechanism 31R is started to reduce the pressing force applied to the rotating body 22 that rotates integrally with the right rear wheel RR. Thereafter, this processing routine is once terminated.

  On the other hand, if the direction of deflection of the spinning vehicle is right deflection in step S303 (S303: YES), the process proceeds to step S307. In step S307, execution of a pressing force reduction process for the right rear wheel RR that drives the electric motor 33 of the electric braking mechanism 31R is started to reduce the pressing force on the rotating body 22 that rotates integrally with the right rear wheel RR. Is shifted to step S308. In step S308, it is determined whether a standby end condition is satisfied. The standby end condition is that the deflection waiting time elapses after the execution of the pressing force reduction process for the right rear wheel RR and the yaw rate after the execution of the pressing force reduction process for the right rear wheel RR is started. This includes both that the amount of change in Yr is greater than or equal to a predetermined amount of change. When the standby end condition is not satisfied (S308: NO), the process of step S308 is repeatedly executed. On the other hand, when the standby end condition is satisfied (S308: YES), the process proceeds to step S309. In step S309, execution of a pressing force reduction process for the left rear wheel RL that drives the electric motor 33 of the electric braking mechanism 31L is started to reduce the pressing force applied to the rotating body 22 that rotates integrally with the left rear wheel RL. Thereafter, this processing routine is once terminated.

Next, the processing routine of FIG. 9 will be described. This processing routine is repeatedly executed every predetermined control cycle while the processing routine shown in FIG. 8 is not executed.
As shown in FIG. 9, when this processing routine is executed, it is first determined in step S311 whether or not the spin return control execution flag is set to ON. When the spin return control execution flag is not set to ON (S311: NO), this processing routine is temporarily ended. On the other hand, when the spin return control execution flag is set to ON (S311: YES), the process proceeds to step S312. In step S312, it is determined whether or not the vehicle spin is detected based on the yaw rate Yr detected by the yaw rate sensor 105. When spin is detected (S312: NO), this processing routine is temporarily terminated. On the other hand, if spin is not detected (S312: YES), the process proceeds to step S313.

  In step S313, it is determined whether or not there is a history of spinning of the vehicle after the spin return control execution flag is set to ON by the processing of step S12 of the processing routine shown in FIG. If there is no spin history (S313: NO), this processing routine is temporarily terminated. On the other hand, if there is a spin history (S313: YES), the process proceeds to step S314.

  Here, in the previous execution of the processing routine shown in FIG. 8 executed to reduce the braking force generated on the left and right rear wheels RL, RR, the vehicle deflection direction determined in the processing of step S303 is “ This is referred to as “previous deflection direction”.

  In step S314, it is determined whether or not the previous deflection direction is right deflection. If the previous deflection direction is not right deflection (S314: NO), the process proceeds to step S315. In step S315, execution of the pressing force increasing process for the right rear wheel RR for driving the electric motor 33 of the electric braking mechanism 31R is started to increase the pressing force on the rotating body 22 that rotates integrally with the right rear wheel RR. Goes to step S316. In step S316, it is determined whether or not the deflection waiting time has elapsed since the execution of the pressing force increasing process for the right rear wheel RR was started. When the deflection standby time has not elapsed (S316: NO), the process of step S316 is repeatedly executed. On the other hand, when the deflection standby time has elapsed (S316: YES), the process proceeds to step S317. In step S317, execution of the pressing force increasing process for the left rear wheel RL for driving the electric motor 33 of the electric braking mechanism 31L is started to increase the pressing force on the rotating body 22 that rotates integrally with the left rear wheel RL. Thereafter, this processing routine is once terminated.

  On the other hand, in step S314, when the previous deflection direction is right deflection (S314: YES), the process proceeds to step S318. In step S318, execution of the pressing force increasing process for the left rear wheel RL for driving the electric motor 33 of the electric braking mechanism 31L is started to increase the pressing force on the rotating body 22 that rotates integrally with the left rear wheel RL. Goes to step S319. In step S319, it is determined whether or not the deflection waiting time has elapsed since the execution of the pressing force increasing process for the left rear wheel RL was started. When the deflection standby time has not elapsed (S319: NO), the process of step S319 is repeatedly executed. On the other hand, when the deflection standby time has elapsed (S319: YES), the process proceeds to step S320. In step S320, execution of the pressing force increasing process for the right rear wheel RR that drives the electric motor 33 of the electric braking mechanism 31R is started to increase the pressing force on the rotating body 22 that rotates integrally with the right rear wheel RR. Thereafter, this processing routine is once terminated.

Next, the effect of the braking device 10 according to the present embodiment will be described.
FIG. 10 shows the antilock control when the braking device 10 performs the processing routine shown in FIG. 4 to perform the antilock control pressing force reduction process, that is, when the vehicle is traveling on the split road surface. The current value Imt of each electric motor 33 in the electric braking mechanisms 31L and 31R when the pressing force reduction process is performed is shown. In the antilock control, first, the execution of the first reduction process is started, and the execution of the second reduction process is started after the first delay time PT1 has elapsed. In the first delay time PT1, a period equal to the time from the timing t1 to the timing t3 in FIG. 10 is set.

  FIG. 10A shows the current value of the electric motor 33 included in one of the electric braking mechanisms 31L and 31R that is activated by executing the first reduction process. At timing t1, the one electric motor 33 is activated. An inrush current is generated with this activation. The inrush current generated from timing t1 reaches the peak value PImt1 at timing t2. Thereafter, the inrush current drops, and at the timing t3, the inrush current generation period TM1 ends. After timing t3, since the pressing force against the rotating body 22 decreases, the current value Imt gradually decreases. At time t6, the pressing force becomes equal to “0”, so that the current value Imt reaches the specified current value TImt1. Then, after timing t6, since the friction materials 23A and 23B are separated from the rotating body 22, the current value Imt is maintained at the specified current value TImt1. Since the execution of the pressing force reduction process is terminated at the subsequent timing t8, the driving of the electric motor 33 is stopped.

  FIG. 10B shows the current value of the electric motor 33 included in the other electric braking mechanism 31 that is activated by executing the second reduction process among the electric braking mechanisms 31L and 31R. The other electric motor 33 is started from timing t3. An inrush current is generated with this activation. The inrush current generated from timing t3 reaches the peak value PImt2 at timing t4. Thereafter, the inrush current decreases, and the generation period of the inrush current ends at timing t5. After timing t5, since the pressing force against the rotating body 22 decreases, the current value Imt gradually decreases. At time t7, the pressing force becomes equal to “0”, so that the current value Imt reaches the specified current value TImt2. Then, after timing t7, since the friction materials 23A and 23B are separated from the rotating body 22, the current value Imt is maintained at the specified current value TImt2. Since the execution of the pressing force reduction process is finished at the subsequent timing t9, the drive of the electric motor 33 is stopped.

  As shown in FIG. 10A, the inrush current generation period TM1 generated when the execution of the first reduction process is started is a period from timing t1 to timing t3. Then, the execution of the second reduction process is started after the first delay time PT1 has elapsed since the execution of the first reduction process was started. For this reason, the time (timing t2) when the inrush current generated when the execution of the first reduction process starts reaches the peak value PImt1, and the inrush current generated when the execution of the second reduction process starts reaches the peak value PImt2. It is possible to suppress the overlap with the timing of reaching (timing t4).

  FIG. 11 shows the anti-lock control when the braking device 10 executes the processing routine shown in FIG. 5 to perform the anti-lock control pressing force increasing process, that is, when the vehicle is traveling on the split road surface. The current value Imt of each electric motor 33 in the electric braking mechanisms 31L and 31R when the pressing force increasing process is performed is shown. In the anti-lock control, first, the execution of the second increase process is started, and the execution of the first increase process is started after the increase delay time PTI has elapsed. In the increase delay time PTI, a period equal to the time from the timing t11 to the timing t13 in FIG. 11 is set.

  FIG. 11A shows the current value of the electric motor 33 provided in one of the electric braking mechanisms 31L and 31R that is activated by the execution of the first increasing process. At timing t13, the one electric motor 33 is activated. An inrush current is generated with this activation. The inrush current generated from timing t13 reaches the peak value PImt3 at timing t14. Thereafter, the inrush current drops, and the generation period of the inrush current ends at timing t15. After the timing t15, the current value Imt is maintained at a constant value during a period in which the friction members 23A and 23B are not yet in contact with the rotating body 22. When the friction members 23A and 23B come into contact with the rotating body 22 at the timing t17, the pressing force against the rotating body 22 gradually increases after the timing t17, so that the current value Imt gradually increases. Thereafter, when the current value Imt reaches the specified current value TImt3 at the timing t19, the execution of the pressing force increasing process is terminated, and the drive of the electric motor 33 is stopped.

  FIG. 11B shows the current value of the electric motor 33 provided in the other electric braking mechanism 31 that is activated by the execution of the second increasing process among the electric braking mechanisms 31L and 31R. The other electric motor 33 is started from timing t11. An inrush current is generated with this activation. The inrush current generated from timing t11 reaches the peak value PImt4 at timing t12. Thereafter, the inrush current drops, and at the timing t13, the inrush current generation period TM4 ends. The current value Imt is maintained at a constant value during a period in which the friction members 23A and 23B are not yet in contact with the rotating body 22 after the timing t13. When the friction members 23A and 23B come into contact with the rotating body 22 at the timing t16, the pressing force against the rotating body 22 gradually increases after the timing t16, so that the current value Imt gradually increases. After that, when the current value Imt reaches the specified current value TImt4 at timing t18, the execution of the pressing force increasing process is terminated, so that the driving of the electric motor 33 is stopped.

  As shown in FIG. 11B, the inrush current generation period TM4 generated when the execution of the second increasing process is started is a period from timing t11 to timing t13. Then, the execution of the first increase process is started after the increase delay time PTI has elapsed since the start of the execution of the second increase process. For this reason, the time (timing t12) when the inrush current generated when the execution of the second increase process starts reaches the peak value PImt4, and the inrush current generated when the execution of the first increase process starts reaches the peak value PImt3. It is possible to suppress the overlap with the timing of reaching (timing t14).

  As described above with reference to FIGS. 10 and 11, when the pressing force reduction process and the pressing force increase process are performed by executing the antilock control by the braking device 10, the left and right rear wheels RL. Among the RRs, a time when the inrush current generated when starting the electric motor 33 corresponding to one wheel reaches a peak value, and a time when the inrush current generated when starting the electric motor 33 corresponding to the other wheel reaches a peak value. , Can be prevented from overlapping. Accordingly, it is possible to suppress a large load from being applied to the power supply 32 of the electric motor 33 when each of the electric braking mechanisms 31L and 31R is operated in accordance with the execution of the antilock control.

  Further, in the present embodiment, the first delay time PT1 from the start of the execution of the first reduction process to the start of the execution of the second reduction process is a rush that occurs due to the execution of the first reduction process. It is set equal to the time length of the current generation period TM1. Further, the first delay time PT1 is set shorter than the time from the start of execution of the first reduction process to the end of execution. Therefore, the execution of the second reduction process can be started while the braking force generated at the wheel having the lower slip ratio is being reduced by the execution of the first reduction process. Accordingly, it is possible to suppress an excessive delay in the start of the reduction of the braking force generated on the wheel having the higher slip rate while suppressing the occurrence time of the inrush currents from overlapping.

  The increase delay time PTI from the start of the execution of the second increase process to the start of the execution of the first increase process is the generation period TM4 of the inrush current generated by the execution of the second increase process. Is set equal to the time length. Furthermore, the increase delay time PTI is set to be shorter than the time from the start of execution of the second increase process to the end of execution. Therefore, the execution of the first increase process can be started while the braking force generated on the wheel having the higher slip rate is being increased by the execution of the second increase process. Accordingly, it is possible to suppress the start of an increase in braking force generated at the wheel having the lower slip ratio from being excessively delayed while suppressing the occurrence time of the inrush currents from overlapping.

  Further, in the antilock control that is performed by running the processing routine shown in FIGS. 6 and 7 by the braking device 10 and traveling on the road surface that is not the split road surface, the execution of the second reduction process is started. After the elapse of the second delay time PT2, the execution of the first reduction process is started. As a result, it is possible to prevent the occurrence times of the inrush currents from overlapping as in the case of traveling on the split road surface. That is, even when the vehicle is traveling on a road surface that is not a split road surface, a large load is applied to the power supply 32 of the electric motor 33 when each of the electric braking mechanisms 31L and 31R is operated in accordance with the execution of the antilock control. Can be suppressed.

  Further, in the present embodiment, the second delay time PT2 from the start of the execution of the second reduction process to the start of the execution of the first reduction process is a rush that occurs due to the execution of the second reduction process. It is set equal to the time length of the current generation period. Therefore, the execution of the first reduction process can be started while the braking force generated on the wheel having the higher slip rate is being reduced by the execution of the second reduction process. Accordingly, it is possible to suppress an excessive delay in the start of a decrease in the braking force generated at the wheel having the lower slip rate while suppressing the occurrence time of the inrush current from overlapping.

  Here, when the road surface on which the vehicle is traveling is a split road surface, the difference between the slip ratios of the left and right rear wheels RL and RR tends to increase. In this regard, according to the present embodiment, in the anti-lock control executed when it is determined that the vehicle is traveling on the split road surface, the wheel with the lower slip ratio among the rear wheels RL and RR is targeted. The first reduction process is started prior to the second reduction process for the wheel with the higher slip rate. As a result, it is possible to suppress an increase in yaw moment due to a difference in braking force generated between the left and right rear wheels RL and RR, and it is possible to suppress a decrease in vehicle behavior stability.

  On the other hand, when the road surface on which the vehicle is traveling is not a split road surface, the difference between the slip ratios of the left and right rear wheels RL and RR is unlikely to increase. Therefore, even when the difference in braking force generated between the left and right rear wheels RL and RR becomes large to some extent at this time, the stability of the vehicle behavior is unlikely to decrease. Therefore, in the present embodiment, in the antilock control executed when it is determined that the vehicle is traveling on a road surface that is not a split road surface, the wheel with the lower slip ratio of both rear wheels RL and RR is targeted. The first reduction process is started after the second reduction process for the wheel with the higher slip rate. That is, it is possible to delay the start of a decrease in braking force generated at the wheel having the larger braking force. Therefore, when the road surface is not a split road surface, it is possible to suppress a decrease in the deceleration of the vehicle.

  Furthermore, when it is determined that the road surface is not a split road surface, the first increase process for the wheel that was the execution target of the first decrease process is the execution target of the second decrease process. This is started before the second increase process for the target wheel. In other words, the braking force generated at the wheel where deceleration slip is difficult to occur even when the braking force is increased is increased first. Accordingly, it is possible to lengthen the period from the start of the pressing force increasing process until the slip ratio of one of the rear wheels RL and RR rises again to the slip ratio determination value KVS or more. That is, it is possible to delay the time when the pressing force reduction process is executed again. Therefore, the deceleration of the vehicle during the antilock control can be increased.

  In the following, the wheel that was the object of execution of the first reduction process, that is, the wheel with the lower slip rate when the slip rate of one wheel is equal to or higher than the slip rate KVS determination value is referred to as “previous non-slip wheel”. Shall. And the wheel which was the execution target of the second reduction process, that is, the wheel with the higher slip rate when the slip rate of one wheel is equal to or higher than the slip rate determination value KVS is referred to as “previous slip wheel”. To do.

  Here, when the road surface on which the vehicle is traveling is a split road surface, when the braking force generated by the previous slip wheel is increased, the slip ratio of the previous slip wheel tends to increase again. Therefore, when the vehicle is traveling on a split road surface, if the first increase process for the previous non-slip wheel is started before the second increase process for the previous slip wheel, The difference in braking force between the left and right rear wheels RL, RR increases, and the yaw moment resulting from the difference increases. That is, the vehicle may be deflected.

  In this regard, in this embodiment, when it is determined that the road surface is a split road surface, the second increase process for the previous slip wheel is the first increase process for the previous non-slip wheel. It starts before. As a result, it is possible to advance the time when the slip ratio of the non-slip wheel is equal to or higher than the slip ratio determination value KVS, and the first time before the difference in braking force generated between the left and right rear wheels RL and RR increases. The execution of the decrease process and the second decrease process can be started. Therefore, it is possible to suppress a decrease in the stability of the vehicle behavior during the antilock control.

  In the spin return control, the left and right rear wheels RL. The determination as to which wheel of the RRs is subjected to the pressing force reduction process first is made based on the deflection direction of the vehicle based on the yaw rate Yr. Also, the left and right rear wheels RL. The determination as to which wheel of the RRs is subjected to the pressing force increasing process first is performed based on the deflection direction of the vehicle when the pressing force decreasing process was previously performed. As a result, even when signals from the wheel speed sensors 101 to 104 are not input to the braking control device 11, it is possible to suppress a decrease in the stability of the behavior of the vehicle.

  Further, in the case of increasing the braking force generated by the left and right rear wheels RL and RR in the spin return control, the pressing force increasing process for the wheel that has decreased the braking force later decreased the braking force first. The process is started before the pressing force increasing process for the other wheel. Therefore, it is possible to suppress the yaw moment from increasing again by increasing the braking force generated by both rear wheels RL and RR. That is, it is possible to suppress a decrease in the stability of the behavior of the vehicle due to an increase in the braking force generated at both rear wheels RL and RR.

  Further, when the spin return control is executed, the left and right rear wheels RL. After the execution of the pressing force reduction process for one wheel of RR is started, the execution of the pressing force reduction process for the other wheel is started after the standby end condition is satisfied. In addition, both rear wheels RL. After the execution of the pressing force increasing process for one wheel in the RR is started, the pressing force increasing process for the other wheel is started after the waiting time for deflection. Thereby, it is possible to suppress the occurrence of inrush currents from overlapping. That is, it is possible to suppress a large load from being applied to the power source 32 of the electric motor 33 when the electric braking mechanisms 31L and 31R are operated in accordance with the execution of the spin return control.

In addition, the said embodiment can also be implemented with the following forms which changed this suitably.
In the above embodiment, the road determination flag or the spin return control execution flag is set by the pre-determination process shown in FIG. 3, and the processing routine to be executed subsequently differs depending on which flag is set to ON. Configured. For example, when the split road surface flag is set to ON, the processing routine shown in FIG. 4 and the processing routine shown in FIG. 5 which are processing routines for the split road surface are executed, while the processing routine shown in FIG. The processing routine shown in FIG. 8, the processing routine shown in FIG. 8, and the processing routine shown in FIG. 9 are not executed. On the other hand, when the antilock control is executed, it may be sequentially determined whether or not the road surface is a split road surface even during the execution of the antilock control. In this case, when the processing routine shown in FIG. 4 and the processing routine shown in FIG. 5 are executed because the split road surface flag is set to ON prior to the execution of the antilock control, the road surface on which the vehicle travels is the split road surface. Otherwise, the uniform road surface flag may be set to ON, and the split road surface flag may be set to OFF. After the uniform road surface flag is set to ON, the processing routine shown in FIG. 6 and the processing routine shown in FIG. 7 are executed instead of the processing routine shown in FIG. 4 and the processing routine shown in FIG. Also good.

  The electric braking mechanism may be an electric brake that can control the pressing force against the rotating body without using brake fluid. In this electric brake, the rotation amount of the electric motor is controlled according to the brake operation amount. Even in such a vehicle braking device having an electric brake, the slip ratio of one of the rear wheels is determined as a slip determination under a situation where the braking force is generated in each rear wheel RL and RR by the operation of each electric brake. When the value becomes equal to or greater than the value KVS, the anti-lock control for starting the execution of the second reduction process may be executed after the execution of the first reduction process is started.

  In the above embodiment, values stored in advance in the antilock control unit 13 are used as the delay times of the first delay time PT1, the second delay time PT2, and the increase delay time PTI. As described above, it is also possible to employ a configuration in which the time setting unit 16 is further provided as a functional unit included in the braking control unit 12 so that the delay time is calculated by the time setting unit 16. That is, each delay time can be varied according to the vehicle situation when the antilock control or the spin return control is being executed.

  The peak value of the inrush current generated when the electric motor is started and the generation period of the inrush current may vary depending on the magnitude of the target current value for the electric motor. In FIG. 13, the transition of the current flowing through the electric motor when the target current value is the target current value TImt11 is shown by a solid line, and the transition of the current flowing through the electric motor when the target current value is the target current value TImt12 is a broken line. It is shown in The target current value TImt12 is smaller than the target current value TImt11.

  As shown in FIG. 13, the inrush current peak value PImt11 when the target current value is the target current value TImt11 is larger than the inrush current peak value PImt12 when the target current value is the target current value TImt12. The inrush current generation period TM11 in the case where the target current value is the target current value TImt11 is a period from the start timing t21 of the electric motor start to the timing t23 when the current drops to the target current value TImt11. On the other hand, the inrush current generation period TM12 when the target current value is the target current value TImt12 is a period from the start timing t21 of the electric motor start to the timing t22 when the current drops to the target current value TImt12. As apparent from FIG. 13, the generation period TM11 is longer than the generation period TM12.

  Therefore, the time setting unit 16 may increase each delay time as the target current value set when starting the electric motor is larger. Thereby, it is possible to suppress the overlap between the time when the inrush current generated by the execution of the first reduction process reaches the peak value and the time when the inrush current generated by the execution of the second reduction process reaches the peak value. According to this configuration, the delay time is shortened as the current value for driving the electric motor is smaller. Therefore, when the rush current generated by the execution of one of the first reduction processes and the second reduction process that has started first reaches the peak value early, the other reduction process is executed early. Can start.

  In the antilock control, the order of executing the first increase process and the second increase process can be switched. For example, when the anti-lock control is executed under the condition that the split road surface flag is set to ON, the execution of the first increasing process is started when the braking force generated in each of the rear wheels RL and RR is increased. Then, after that, the execution of the second increase process may be started. In addition, when the anti-lock control is executed under the condition that the uniform road surface flag is set to ON, the execution of the second increase process is started when the braking force generated in each of the rear wheels RL and RR is increased. Thereafter, the execution of the first increase process may be started.

  In the above embodiment, different values are set for the first delay time PT1 corresponding to the first reduction process and the second delay time PT2 corresponding to the second reduction process. The same value can be set as the first delay time PT1 and the second delay time PT2.

  In the above embodiment, the delay times of the first delay time PT1, the second delay time PT2, and the increase delay time PTI are set to be equal to the time length of the inrush current generation period. However, if the time when the inrush current generated at the start of one electric motor 33 reaches the peak value and the time when the inrush current generated at the start of the other electric motor 33 reaches the peak value can be shifted, Each delay time may be set arbitrarily. For example, each delay time may be longer than the time length of the inrush current generation period, or may be shorter than the time length of the inrush current generation period.

  The first delay time PT1 can be longer than the time from the start of execution of the first reduction process to the end of execution. In addition, the second delay time PT2 can be longer than the time from the start of execution of the second reduction process to the end of execution.

  In the above embodiment, when the split road surface flag is set to ON, the antilock control is executed by the processing routine shown in FIGS. On the other hand, when the uniform road surface flag is set to ON, the anti-lock control is executed by the processing routine shown in FIGS. Even when the split road surface flag is not set to ON, the anti-lock control is executed by the processing routines shown in FIGS. 4 and 5 instead of the processing routines shown in FIGS. You can also.

  The road surface determination unit 14 may determine whether the road surface is a split road surface using parameters other than the slip ratio difference ΔSLP. In a situation where braking force is generated in each rear wheel RL, RR by executing the braking process, if the road surface is a split road surface, the vehicle may show a deflection tendency, that is, the yaw rate Yr may increase. is there. On the other hand, when the road surface is a split road surface, the vehicle is less likely to show a deflection tendency, that is, the yaw rate Yr is difficult to increase. Therefore, when the yaw rate Yr in the situation where the braking force is generated in each rear wheel RL and RR by execution of the braking process is greater than or equal to the determination value, the road surface is determined to be the split road surface, while the yaw rate Yr is the determination value. If it is less, the road surface may be determined not to be a split road surface.

  In the anti-lock control in the above-described embodiment, after the pressing force on the rotating body 22 that rotates integrally with the rear wheels RL and RR becomes “0” due to the execution of the pressing force reduction process, the rear wheels RL and RR Each pressing force decreasing process is executed to increase the pressing force on the rotating body 22 that rotates integrally. However, the deceleration slip of the rear wheels RL and RR may be eliminated before the pressing force against the rotating body 22 becomes “0”. Therefore, the slip rates SLPL and SLPR of the rear wheels RL and RR are monitored during the execution of each pressing force reduction process, and when the slip rates SLPL and SLPR are both less than the slip cancellation determination value. The execution of each pressing force reduction process may be terminated.

The electric braking mechanism may be a drum mechanism instead of the disk mechanism as in the above embodiment.
The vehicle braking device may be applied to a vehicle in which braking force is generated at the front wheels by the operation of the electric braking mechanism.

Next, the technical idea that can be grasped from the above embodiment and another embodiment will be added below.
(A) An electric braking mechanism corresponding to each of the left and right wheels of the vehicle is provided, and each of the electric braking mechanisms applies a pressing force that is a force for pressing the friction material against a rotating body that rotates integrally with the wheel by driving of the electric motor. Vehicle braking devices each configured to adjust the braking force generated by the wheels by controlling,
A braking control unit that executes a braking process to increase the braking force generated by the left and right wheels by operating each electric braking mechanism in response to a braking request;
When the slip rate of one of the left and right wheels is equal to or greater than a slip rate determination value under a situation in which braking force is generated on the left and right wheels by execution of the braking process by the braking control unit, Of the left and right wheels, a first reduction process for driving the electric motor corresponding to the wheels to reduce the pressing force on the rotating body that rotates integrally with the wheel with the lower slip rate, and the slip rate is An antilock control unit that executes antilock control including a second reduction process for driving the electric motor corresponding to the wheel to reduce the pressing force on the rotating body that rotates integrally with the higher wheel; and
A road surface determination unit that determines whether or not the road surface on which the vehicle is traveling is a split road surface,
In the anti-lock control, the anti-lock control unit starts execution of one of the first reduction process and the second reduction process first, and executes the other reduction process later. To start,
In the anti-lock control, the anti-lock control unit determines a reduction process to be executed first out of the first reduction process and the second reduction process based on the determination result by the road surface determination unit. Brake device for vehicles.

  According to the above configuration, it is possible to execute antilock control according to the road surface condition of the vehicle.

  DESCRIPTION OF SYMBOLS 10 ... Brake device, 11 ... Brake control device, 12 ... Brake control part, 13 ... Anti-lock control part, 14 ... Road surface determination part, 15 ... Wheel monitoring part, 16 ... Time setting part, 20 ... Regular brake device, 21 ... Hydraulic pressure generating device, 21A ... master chamber, 22 ... rotating body, 23A ... friction material, 23B ... friction material, 24 ... caliper, 25 ... wheel cylinder, 25A ... bottom, 26 ... cylinder chamber, 27 ... piston, 28 ... braking Actuator, 30 ... Parking brake device, 31L, 31R ... Electric brake mechanism, 32 ... Power source, 33 ... Electric motor, 34 ... Output shaft, 35 ... First gear, 36 ... Second gear, 37 ... Rod member, 38 ... Nut 91 ... Brake pedal, 92 ... Operation amount sensor, 93 ... Operation unit, 101, 102, 103, 104 ... Wheel speed sensor, 105 ... Yaw rate sensor.

Claims (6)

An electric braking mechanism corresponding to each of the left and right wheels of the vehicle is provided, and each of the electric braking mechanisms controls a pressing force that is a force pressing the friction material against a rotating body that rotates integrally with the wheel by driving of the electric motor. And each of the vehicle braking devices configured to adjust a braking force generated by the wheel,
A braking control unit that executes a braking process to increase the braking force generated by the left and right wheels by operating each electric braking mechanism in response to a braking request;
When the slip rate of one of the left and right wheels is equal to or greater than a slip rate determination value under a situation in which braking force is generated on the left and right wheels by execution of the braking process by the braking control unit, Of the left and right wheels, a first reduction process for driving the electric motor corresponding to the wheels to reduce the pressing force on the rotating body that rotates integrally with the wheel with the lower slip rate, and the slip rate is An anti-lock control unit that executes anti-lock control including a second reduction process for driving the electric motor corresponding to the wheel to reduce the pressing force on the rotating body that rotates integrally with the higher wheel. ,
In the anti-lock control, the anti-lock control unit starts executing the first reduction process, and then starts executing the second reduction process. The antilock control unit is configured to start executing the second reduction process after a lapse of a specified time from the start of execution of the first reduction process.
The vehicle braking device according to claim 1, wherein the specified time is set to a time shorter than a period from the start to the end of execution of the first reduction process. The antilock control unit is configured to start executing the second reduction process after a lapse of a specified time from the start of execution of the first reduction process.
When the first reduction process is executed, a time setting unit that lengthens the specified time as the current value for driving the electric motor corresponding to the wheel to be subjected to the first reduction process increases. The vehicular braking apparatus according to claim 1 or 2. A road surface determination unit for determining whether the road surface on which the vehicle is traveling is a split road surface;
The antilock control unit
In the anti-lock control when the road surface determination unit determines that the road surface is a split road surface, the execution of the first reduction process is started, and then the execution of the second reduction process is started. In the antilock control when the road surface determination unit determines that the road surface is not a split road surface, the execution of the second reduction process is started, and then the execution of the first reduction process is started. The vehicle braking device according to claim 1. The antilock control unit
In the antilock control when the road surface determination unit determines that the road surface is a split road surface, the second reduction process is performed after the first delay time has elapsed since the execution of the first reduction process was started. On the other hand, in the antilock control when the road surface determination unit determines that the road surface is not a split road surface, the second delay time has elapsed since the execution of the second reduction process was started. The execution of the first reduction process is started later,
The first delay time is set shorter than a period from the start to the end of execution of the first reduction process,
The vehicle braking device according to claim 4, wherein the second delay time is set shorter than a period from the start to the end of the execution of the second reduction process. The antilock control unit
In the anti-lock control when the road surface determination unit determines that the road surface is not a split road surface, after the left and right braking forces are reduced by executing the first reduction process and the second reduction process The first increasing process of driving the electric motor corresponding to the wheel to increase the pressing force to the rotating body that rotates integrally with the wheel that is the execution target of the first decreasing process among the left and right wheels. The electric motor corresponding to the wheel is driven to increase the pressing force on the rotating body that rotates integrally with the wheel that is the execution target of the second reduction process among the left and right wheels. On the other hand, in the antilock control when the road surface determination unit determines that the road surface is a split road surface, the first increase process starts. After the left and right braking forces are reduced by executing the decrease process and the second decrease process, the second increase process is started, and then the first increase process is started. Item 6. The vehicle braking device according to Item 4 or 5.