JP2020100318A - Vehicular braking device and control method of vehicular braking device - Google Patents

Abstract

To provide a vehicular braking device and a control method of the same capable of reducing the total number of filters disposed for collecting a foreign matter in brake fluid flowing through a pressure reduction valve.SOLUTION: In a vehicular braking device capable of distributing braking force into hydraulic braking force and regenerative braking force, a control device (90) opens a first pressure reduction valve (54aa) in a condition in which pressure of a side of a first hydraulic brake (38a) for generating hydraulic braking force at a front wheel (RF) is higher than pressure of a side of an accumulator (71a), where the accumulator is supplied with the brake fluid during pressure reduction by the first pressure reduction valve (54aa) for reducing pressure of the hydraulic braking force of the first hydraulic brake (38a) or by a second pressure reduction valve (54ba) for reducing pressure of the hydraulic braking force of a second hydraulic brake (38b) for generating the hydraulic braking force at a rear wheel (LR).SELECTED DRAWING: Figure 2

Description

The present invention relates to a vehicle brake device and a vehicle brake device control method.

Conventionally, a vehicle brake device includes a hydraulic brake that generates a hydraulic braking force by using a hydraulic pressure that is generated according to a brake operation of a driver, and a regenerative brake that generates a regenerative braking force. There is known a vehicle brake device capable of executing control for distributing a braking force to a braking force and a regenerative braking force (hereinafter, also referred to as "regenerative cooperation").

The purpose of the regenerative brake used in the vehicle brake device is to convert the kinetic energy of the wheel at the time of braking into electric energy so as to effectively utilize the energy. The maximum regenerative braking force that can be regenerated by the regenerative brake is limited by the vehicle speed during braking of the vehicle, the state of charge of the battery, and the like. Therefore, even while the hydraulic brake is operating, the ratio of the braking force by the hydraulic brake and the braking force by the regenerative brake can be changed according to the maximum regenerative braking force to increase the ratio of the regenerative brake. It is also preferable from the viewpoint of effective use of energy.

Various methods have been proposed for performing regenerative coordination. For example, in Patent Document 1, it is provided between the hydraulic brakes of the front wheels and the hydraulic brakes of the rear wheels, and the flow rate of the brake fluid from the hydraulic brake side of the front wheels to the hydraulic brake side of the rear wheels is continuously changed. Equipped with an adjustable valve and a pressure reducing valve capable of reducing the pressure of the brake fluid supplied to the hydraulic brakes of the rear wheels, in order to reduce the hydraulic braking force of the hydraulic brakes of the front wheels, A vehicle brake device is disclosed in which the opening of a regulating valve is continuously increased and a pressure reducing valve on the rear wheel side is opened.

International Publication No. 2012/086290

However, when the vehicle brake device disclosed in Patent Document 1 is applied to a front-wheel drive hybrid vehicle and an electric vehicle that drive the front wheels of the vehicle by the driving force output from the internal combustion engine or the drive motor, regenerative cooperation is performed. During the operation, the rear wheels are controlled so that no braking force is generated. Specifically, in the vehicle brake device disclosed in Patent Document 1, in generating a hydraulic braking force together with a regenerative braking force acting on the front wheels, an adjusting valve for supplying brake fluid to the hydraulic brakes for the front wheels and By holding the pressure reducing valve that reduces the hydraulic braking force of the rear wheels in the open state and controlling the opening of the adjustment valve on the rear wheel side, the front wheel can be controlled as much as possible without generating hydraulic braking force on the rear wheels. The hydraulic braking force is adjusted so that the sum of the hydraulic braking force and the regenerative braking force matches the braking force required by the driver.

Therefore, the ratio of the braking force distributed to the front wheels becomes excessively large, and the vehicle may exhibit unstable behavior such as an understeer state. When the vehicle is in an understeer state, in order to stabilize the behavior of the vehicle, it is necessary to reduce the regenerative braking force of the front wheels while increasing the hydraulic braking force of the rear wheels, which may reduce the energy utilization efficiency. There is.

On the other hand, while regenerative coordination is performed, hydraulic braking force is generated on the rear wheels together with the regenerative braking force acting on the front wheels, so that the braking force balance between the front wheels and the rear wheels is improved. It is considered that the stability of the behavior is improved and the reduction of the energy utilization efficiency can be suppressed. However, when the hydraulic braking force is generated by the rear wheels to adjust the hydraulic braking force, the brake fluid may flow in both directions via the pressure reducing valve of the hydraulic brake of the front wheels. In this case, it is necessary to provide two filters in order to collect foreign matter mixed in the brake fluid that flows through the pressure reducing valve on the front wheel side in both directions. While only the regenerative braking force is being generated, the brake fluid flowing from the master cylinder into the hydraulic circuit is taken in and out of the low pressure accumulator via the pressure reducing valve on the rear wheel side, and therefore the brake fluid is applied to the pressure reducing valve on the rear wheel side. Two filters are provided. Therefore, for example, in the case of a four-wheeled vehicle, it is necessary to provide eight filters for four pressure reducing valves.

The present invention has been made in view of the above problems, and provides a vehicle brake device and a control method therefor capable of reducing the total number of filters provided for collecting foreign matter in brake fluid passing through a pressure reducing valve. ..

According to one aspect of the present invention, a first hydraulic brake that generates hydraulic braking force on the front wheels, a second hydraulic brake that generates hydraulic braking force on the rear wheels, and kinetic energy of the front wheels are converted. And a regenerative brake that generates a regenerative braking force, and is capable of distributing the braking force to the hydraulic braking force and the regenerative braking force, the brake fluid being supplied to the first hydraulic brake. Adjusting valve for continuously adjusting the flow rate of the first hydraulic brake, a second adjusting valve for continuously adjusting the flow rate of the brake fluid supplied to the second hydraulic brake, and a hydraulic pressure for the first hydraulic brake. A first pressure reducing valve for reducing the braking force, a second pressure reducing valve for reducing the hydraulic braking force of the second hydraulic brake, and a brake fluid during the pressure reduction by the first pressure reducing valve or the second pressure reducing valve. An accumulator to be supplied and a control device for controlling the first adjusting valve, the first pressure reducing valve, the second adjusting valve and the second pressure reducing valve are provided, and the control device is on the first hydraulic brake side. There is provided a vehicle brake device that opens the first pressure reducing valve in a state where the pressure is higher than the pressure on the accumulator side.

According to another aspect of the present invention, a first hydraulic brake that generates hydraulic braking force on the front wheels, a second hydraulic brake that generates hydraulic braking force on the rear wheels, and a movement of the front wheels. A regenerative brake that converts energy to generate a regenerative braking force, a first adjustment valve that continuously adjusts the flow rate of the brake fluid that is supplied to the first hydraulic brake, and a second hydraulic brake that is supplied A second adjusting valve for continuously adjusting the flow rate of the brake fluid, a first pressure reducing valve for reducing the hydraulic braking force of the first hydraulic brake, and a hydraulic braking force of the second hydraulic brake are provided. A second pressure reducing valve for reducing pressure, an accumulator to which brake fluid is supplied when pressure is reduced by the first pressure reducing valve or the second pressure reducing valve, a first adjusting valve, a first reducing valve, a second adjusting valve, and And a control device for controlling the second pressure reducing valve, wherein the braking device can distribute the braking force to the hydraulic braking force and the regenerative braking force. Provided is a method for controlling a vehicle brake device, which opens the first pressure reducing valve in a state where the pressure on the pressure brake side is higher than the pressure on the accumulator side.

As described above, according to the present invention, it is possible to reduce the total number of filters provided for collecting foreign matter in the brake fluid that passes through the pressure reducing valve.

It is a schematic diagram showing an example of composition of a brake equipment for vehicles concerning an embodiment of the invention. It is explanatory drawing of the hydraulic circuit which comprises the hydraulic brake in the vehicle brake device which concerns on the same embodiment. It is explanatory drawing which shows the state of a hydraulic circuit while a braking force is produced only with a regenerative braking force. It is explanatory drawing which shows the state of a hydraulic circuit while a braking force is distributed to the hydraulic braking force and the regenerative braking force. It is explanatory drawing which shows the state of the hydraulic circuit at the time of generating hydraulic braking force from the state which has produced only regenerative braking force. It is explanatory drawing which shows the state of a hydraulic circuit when a brake pedal is rapidly released. It is a flow chart which shows processing by a brake ECU of the brake equipment for vehicles concerning the embodiment. It is a timing chart which shows an example of operation of a brake equipment for vehicles. It is a flowchart which shows the process at the time of generating hydraulic braking force from the state which has produced only regenerative braking force. 7 is a timing chart showing an operation when hydraulic braking force is generated from a state where only regenerative braking force is generated. It is a timing chart which shows a reference example. 6 is a flowchart of a process performed when the brake pedal is suddenly released in a state where the braking force is distributed to the regenerative braking force and the hydraulic braking force.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the present specification and the drawings, constituent elements having substantially the same functional configuration are designated by the same reference numerals, and a duplicate description will be omitted.

<1. Overall configuration of vehicle brake system>
First, the overall configuration of the vehicle brake device according to the present embodiment will be described. FIG. 1 is a schematic diagram showing a configuration example of a vehicle brake device 100. In FIG. 1, for ease of understanding, only one front wheel F and one rear wheel R are shown.

The vehicle brake device 100 according to the present embodiment includes a hydraulic brake and a regenerative brake that utilizes the kinetic energy of the front wheels. In the vehicle brake device 100, the braking force is distributed between the hydraulic braking force and the regenerative braking force with respect to the braking force required by the driver.

The vehicle brake device 100 is equipped with a drive motor 125 as a regenerative brake that functions as a drive source for driving the front wheels during traveling and functions as a generator during braking to generate a regenerative braking force on the front wheels F. The drive of the drive motor 125 is controlled by the motor ECU 110. Specifically, the motor ECU 110 controls the operation of the inverter 123 to supply the electric power of the battery 121 to the drive motor 125 or charge the battery 121 with the regenerated electric power from the drive motor 125.

Further, the vehicle brake device 100 is equipped with hydraulic brakes 38a and 38b that generate hydraulic braking forces corresponding to the hydraulic pressures supplied to the front wheels F and the rear wheels R, respectively. The hydraulic pressure of the brake fluid supplied to each of the hydraulic brake (first hydraulic brake) 38a of the front wheel F and the hydraulic brake (second hydraulic brake) 38b of the rear wheel R is controlled by the brake ECU 90. It Specifically, the brake ECU 90 adjusts the hydraulic pressure supplied to the hydraulic brake 38a for the front wheel F and the hydraulic brake 38b for the rear wheel R by controlling the operation of the hydraulic unit 20.

That is, the vehicle brake device 100 according to the present embodiment can generate the regenerative braking force and the hydraulic braking force on the front wheels F, and can generate the hydraulic braking force on the rear wheels R. ..

The brake ECU 90 and the motor ECU 110 are communicably connected via a network such as CAN (Controller Area Network). The brake ECU 90 controls the regenerative braking force generated on the front wheels F by giving a regenerative braking command value to the motor ECU 110. The motor ECU 110 transmits, to the brake ECU 90, information on the maximum value of the regenerative braking force that can be output at that time.

The brake ECU 90 or the motor ECU 110 may be partially or wholly configured by, for example, a microcomputer, a microprocessor unit, or the like, or may be configured by updatable firmware or the like. Further, a part or all of the brake ECU 90 or the motor ECU 110 may be a program module or the like executed by a command from the CPU or the like.

In addition to the stroke signal supplied from the electric booster 13 and the sensor signal of the master cylinder hydraulic pressure sensor 24 that detects the hydraulic pressure in the master cylinder 14 (master cylinder pressure), the brake ECU 90 receives each wheel RF. , LR, LF, RR, the sensor signals from a wheel speed sensor or the like (not shown) indicating the rotation speeds are input (see FIG. 2).

<2. Hydraulic circuit>
Next, with reference to FIG. 2, an example of the hydraulic circuit 1 constituting the hydraulic brake in the vehicle brake device according to the present embodiment will be briefly described.

The hydraulic circuit 1 shown in FIG. 2 is a hydraulic circuit of a brake system for a four-wheeled vehicle. The hydraulic circuit 1 is provided with two brake systems, and is applied to a so-called X-type piping type hydraulic circuit that brakes one front wheel and each rear wheel diagonally opposite to the front wheel in each system as one set. It The brake fluid pressure circuit 1 can be widely applied to vehicles including not only four-wheeled vehicles but also two-wheeled vehicles.

In the hydraulic circuit 1, the pedaling force applied to the brake pedal 11 is amplified by the booster 13 and transmitted to the master cylinder 14 as a hydraulic pressure generation source. In the master cylinder 14, two pressurizing chambers defined by a primary piston and a secondary piston are formed. Each piston is pressed in response to the driver's depression operation of the brake pedal, and the brake fluid moves into the hydraulic circuit 1 via the hydraulic port communicating with each pressurizing chamber.

The booster 13 is connected to the brake pedal 11 side via the input rod 15, and the amplified pedal force is transmitted to the master cylinder 14 via the push rod connected to the primary piston. In the present embodiment, an electric booster is used as the booster 13. The electric booster is a device capable of adjusting the amplification force when transmitting the pedaling force of the brake pedal 11 by the driver to the piston of the master cylinder 14. Further, the pedaling force of the brake pedal 11 and the amplifying force of the booster 13 by the driver press the output rod of the booster 13 toward the master cylinder 14, while the return spring provided in the booster 13 The return force and the reaction force of the master cylinder 14 press the output rod in opposite directions. That is, the amplifying force assists the driver's depression operation of the brake pedal 11, and the restoring force of the return spring ensures that the booster 13 and the brake pedal 11 return to the initial position after the driver operates the brake. Further, the reaction force of the master cylinder 14 acts against the depression operation of the brake pedal 11 by the driver.

From the hydraulic pressure ports communicating with the two pressurizing chambers of the master cylinder 14, the first hydraulic circuit 28 and the second hydraulic circuit 28 are respectively directed toward the hydraulic brakes 38a to 38d of the wheels RF, LR, LF, RR, respectively. The pressure circuit 30 extends. The hydraulic circuit 1 of the vehicle brake device according to the present embodiment is of an X-type piping system, and the wheel cylinder of the hydraulic brake 38a for the right front wheel RF and the wheel cylinder of the hydraulic brake 38b for the left rear wheel LR are Brake fluid is supplied through the hydraulic circuit 28 of No. 1. Further, brake fluid is supplied to the wheel cylinder of the hydraulic brake 38c for the left front wheel LF and the wheel cylinder of the hydraulic brake 38d for the right rear wheel RR via the second hydraulic circuit 30. As a result, each of the hydraulic brakes 38a to 38d can generate a braking force on each wheel RF, LR, LF, RR by the hydraulic pressure.

The hydraulic circuit 1 includes a first hydraulic circuit 28 and a second hydraulic circuit 30 having the same configuration. Brake fluid is supplied from the master cylinder 14 to the first hydraulic circuit 28 and the second hydraulic circuit 30. Hereinafter, the first hydraulic circuit 28 will be briefly described, and the description of the second hydraulic circuit 30 will be omitted.

The first hydraulic circuit 28 includes, as electromagnetic valves, a normally open type linear controllable circuit control valve 36a, a normally closed type on-off controlled intake valve 34a, and a normally open type linearly controllable pressure increasing valve. (Adjusting valves) 58aa and 58ba, and pressure reducing valves 54aa and 54ba that are normally closed and are on/off controlled. The first hydraulic circuit 28 also includes a pump 44a driven by a pump motor 96, a low pressure accumulator 71a, and a damper 73a. The number of pumps 44a is not limited to one.

The first pressure increasing valve 58aa and the first pressure reducing valve 54aa provided adjacent to the hydraulic brake 38a of the right front wheel RF are used for ABS (Antilock Brake System) control or ESC (Electronic Stability Control) control of the right front wheel RF. Used. The second pressure increasing valve 58ba and the second pressure reducing valve 54ba provided adjacent to the hydraulic brake 38b of the left rear wheel LR are used for ABS control or ESP control of the left rear wheel LR.

The first pressure increasing valve 58aa for the right front wheel RF is provided between the circuit control valve 36a and the hydraulic brake 38a for the right front wheel RF. The linearly controllable first pressure increasing valve 58aa continuously adjusts the flow rate of the brake fluid from the circuit control valve 36a side to the wheel cylinder side of the hydraulic brake 38a for the right front wheel RF. The first pressure increasing valve 58aa is provided with a check valve that allows the brake fluid to flow from the hydraulic brake 38a side to the circuit control valve 36a side while limiting the flow in the opposite direction when the first pressure increasing valve 58aa is closed. With a bypass flow path.

The first pressure reducing valve 54aa of the right front wheel RF is a solenoid valve that can switch the valve only to a fully open or fully closed state, and is provided between the wheel cylinder of the hydraulic brake 38a of the right front wheel RF and the low pressure accumulator 71a. Has been. The first pressure reducing valve 54aa reduces the brake fluid supplied to the wheel cylinder of the hydraulic brake 38a for the right front wheel RF in the open state. The first pressure reducing valve 54aa can adjust the flow rate of the brake fluid flowing from the wheel cylinder of the hydraulic brake 38a for the right front wheel RF to the low pressure accumulator 71a by intermittently repeating the opening and closing of the valve.

The second pressure increasing valve 58ba of the left rear wheel LR is provided between the circuit control valve 36a and the hydraulic brake 38b of the left rear wheel LR. The linearly controllable second pressure increasing valve 58ba continuously adjusts the flow rate of the brake fluid from the circuit control valve 36a side to the wheel cylinder side of the hydraulic brake 38b of the left rear wheel LR. The second pressure increasing valve 58ba is provided with a check valve that allows the brake fluid to flow from the hydraulic brake 38b side to the circuit control valve 36a side while restricting the flow in the opposite direction when the second pressure increasing valve 58ba is closed. With a bypass flow path.

The second pressure reducing valve 54ba of the left rear wheel LR is a solenoid valve capable of switching the valve only to a fully open or fully closed state, and is provided between the wheel cylinder of the hydraulic brake 38b of the left rear wheel LR and the low pressure accumulator 71a. It is provided in. The second pressure reducing valve 54ba reduces the brake fluid supplied to the wheel cylinder of the hydraulic brake 38b for the left rear wheel LR in the open state. The second pressure reducing valve 54ba can adjust the flow rate of the brake fluid flowing from the wheel cylinder of the hydraulic brake 38b of the left rear wheel LR to the low pressure accumulator 71a by intermittently repeating the opening and closing of the valve.

The circuit control valve 36a is provided so as to connect or disconnect between the pressure increasing valves 58aa, 58ba and the master cylinder 14. The suction valve 34a is provided so as to communicate or block between the master cylinder 14 and the suction side of the pump 44a. A master cylinder hydraulic pressure sensor 24 is provided in the conduit between the circuit control valve 36a and the intake valve 34a and the master cylinder 14. Since these are the same as the components for the conventional ESC control, detailed description will be omitted.

The second hydraulic circuit 30 controls the hydraulic brake 38c for the left front wheel LF and the hydraulic brake 38d for the right rear wheel RR. The second hydraulic circuit 30 replaces the wheel cylinder of the hydraulic brake 38a of the right front wheel RF in the description of the first hydraulic circuit 28 with the wheel cylinder of the hydraulic brake 38c of the left front wheel LF, and replaces the wheel cylinder of the left rear wheel LR. The configuration is similar to that of the first hydraulic circuit 28 except that the wheel cylinder of the hydraulic brake 38b is replaced with the wheel cylinder of the hydraulic brake 38d of the right rear wheel RR.

<3. Operation>
Next, an operation example of the vehicle brake device 100 according to the present embodiment during regenerative cooperation will be described. In the following description, the operation of the vehicle brake device 100 will be described while showing only the first hydraulic circuit 28, but the second hydraulic circuit 30 also operates similarly.

FIG. 3 shows a state of the first hydraulic circuit 28 while the braking force is generated only by the regenerative braking force, and FIG. 4 shows a state in which the braking force is distributed to the hydraulic braking force and the regenerative braking force. The state of the first hydraulic circuit 28 is shown.

As shown in FIG. 3, while the braking force is generated only by the regenerative braking force, the circuit control valve 36a, the second pressure increasing valve 58ba, and the second pressure reducing valve 54ba are maintained in the open state, and the suction valve 34a, The first pressure increasing valve 58aa and the second pressure reducing valve 54aa are maintained in the closed state. The brake fluid supplied from the master cylinder 14 to the first hydraulic circuit 28 is not supplied to the hydraulic brake 38a side of the right front wheel RF, but is supplied to the hydraulic brake 38b side of the left rear wheel LR.

However, since the second pressure reducing valve 54ba is maintained in the open state, the brake fluid supplied to the hydraulic brake 38b side of the left rear wheel LR is supplied to the low pressure accumulator 71a via the second pressure reducing valve 54ba. Supplied. Therefore, no hydraulic braking force is generated in the hydraulic brake 38b of the left rear wheel LR, and the braking force is exerted only by the regenerative braking force generated in the right front wheel RF. At this time, the first pressure increasing valve 58aa and the first pressure reducing valve 54aa are closed so that the drag torque is not generated by the residual pressure due to the spring force of the low pressure accumulator 71a and the hydraulic braking force does not act on the right front wheel RF. Has been.

In the state shown in FIG. 3, the amount of brake fluid supplied from the master cylinder 14 to the first hydraulic circuit 28 increases or decreases in accordance with the stroke signal supplied from the electric booster 13, so that the left rear wheel The brake fluid supplied to the hydraulic brake 38b side of the LR can flow bidirectionally through the second pressure reducing valve 54ba. For this reason, the second pressure reducing valve 54ba has a filter for collecting foreign matter flowing from the hydraulic brake 38b side of the left rear wheel LR to the low pressure accumulator 71a side, and the liquid of the left rear wheel LR from the low pressure accumulator 71a side. A filter for collecting foreign matter flowing toward the pressure brake 38b is provided.

Further, as shown in FIG. 4, while the braking force is distributed to the regenerative braking force and the hydraulic braking force, the circuit control valve 36a, the first pressure reducing valve 54aa and the second pressure increasing valve 58ba are in the open state. The suction valve 34a and the second pressure reducing valve 54ba are maintained in the closed state. Then, the flow rate of the brake fluid supplied to the hydraulic brake 38a side of the right front wheel RF is adjusted by adjusting the opening degree of the first pressure increasing valve 58aa, and is supplied to the hydraulic brake 38b of the left rear wheel LR. Adjust the fluid pressure.

At this time, since the first pressure reducing valve 54aa is maintained in the open state, the brake fluid supplied to the hydraulic brake 38a side of the right front wheel RF is supplied to the low pressure accumulator 71a via the first pressure reducing valve 54aa. Supplied. Therefore, a relatively small hydraulic braking force is generated in the hydraulic brake 38a for the front right wheel RF in accordance with the spring force of the low pressure accumulator 71a. Therefore, the regenerative braking force and the hydraulic braking force generated on the right front wheel RF and the hydraulic braking force generated on the left rear wheel LR exert a balanced braking force on the front and rear wheels. The maximum regenerative braking force that can be regenerated by the regenerative brake is limited by the vehicle speed during braking of the vehicle and the state of charge of the battery.Therefore, the remaining braking force obtained by subtracting the regenerative braking force from the driver's requested braking force is hydraulically adjusted. The opening degree of the first pressure increasing valve 58aa is adjusted as the target value of the braking force.

Similarly, in the other second hydraulic circuit 30, the regenerative braking force and the hydraulic braking force generated on the left front wheel LF and the hydraulic braking force generated on the right rear wheel RR exert a balanced braking force on the front and rear wheels. .. As a result, the braking force is distributed to the front wheels and the rear wheels, and an unstable behavior of the vehicle such as an understeer state due to an increase in the ratio of the braking force generated on the front wheels can be suppressed. Further, since it is not necessary to reduce the regenerative braking force in order to eliminate the unstable behavior of the vehicle, it is possible to suppress the reduction in energy utilization efficiency.

Here, when it becomes impossible to cover the braking force required by the driver with only the regenerative braking force, and when the state shown in FIG. 3 shifts to the state shown in FIG. 4, as shown in FIG. The valve 54ba is closed and the first pressure reducing valve 54aa is opened, and the hydraulic pressure of the hydraulic brake of the left rear wheel LR is increased. At this time, if the first pressure reducing valve 54aa is opened while the pressure on the low pressure accumulator 71a side is higher than the pressure on the hydraulic brake 38a side of the right front wheel RF, the hydraulic brake 38a of the right front wheel RF from the low pressure accumulator 71a side is opened. Brake fluid moves to the side.

When controlling the first pressure reducing valve 54aa in this manner, not only the second pressure reducing valve 54ba of the hydraulic brake 38b of the left rear wheel LR but also the first pressure reducing valve 54aa of the hydraulic brake 38a of the right front wheel RF is controlled. Also, the brake fluid may flow from the hydraulic brakes 38a and 38b side to the low pressure accumulator 71a side and from the low pressure accumulator 71a side to the hydraulic brakes 38a and 38b side. Therefore, in each of the first pressure reducing valve 54aa and the second pressure reducing valve 54ba, a filter for preventing foreign matters from flowing from the hydraulic brake 38a side to the low pressure accumulator 71a side, and a hydraulic brake from the low pressure accumulator 71a side. A filter is required to prevent foreign matter from flowing into the 38a side.

On the other hand, in the vehicle brake device 100 according to the present embodiment, when the state shown in FIG. 3 is changed to the state shown in FIG. 4, the pressure on the hydraulic brake 38a side of the right front wheel RF is on the low pressure accumulator 71a side. The first pressure reducing valve 54aa is opened after the pressure becomes higher than the pressure. Therefore, the brake fluid does not flow from the low pressure accumulator 71a side to the hydraulic brake 38a side of the right front wheel RF in the first pressure reducing valve 54aa. Therefore, it is possible to omit the filter for preventing foreign matter from flowing from the first pressure reducing valve 54aa to the hydraulic brake 38a side from the low pressure accumulator 71a side.

Further, in the state shown in FIG. 4, when the driver quickly releases the brake pedal 11, the master cylinder pressure becomes zero and the brake fluid in the first hydraulic circuit 28 flows into the master cylinder 14. Along with this, as shown in FIG. 6, the brake fluid moves from the hydraulic brake 38a side of the right front wheel RF to the circuit control valve 36a side via the check valve provided in the first pressure increasing valve 58aa. As a result, the pressure on the hydraulic brake 38a side of the right front wheel RF may be lower than the pressure on the low pressure accumulator 71a side.

At this time, if the first pressure reducing valve 54aa is maintained in the open state, the brake fluid moves from the low pressure accumulator 71a side to the hydraulic brake 38a side of the right front wheel RF. Also in this case, a filter for preventing foreign matter from flowing from the hydraulic brake 38a side to the low pressure accumulator 71a side and a low pressure accumulator 71a side into each of the first pressure reducing valve 54aa and the second pressure reducing valve 54ba. A filter is required to prevent foreign matter from flowing into the hydraulic brake 38a.

On the other hand, in the vehicle brake device 100 according to the present embodiment, in the state shown in FIG. 4, when the driver quickly releases the brake pedal 11, the pressure on the hydraulic brake 38a side of the right front wheel RF is low. The first pressure reducing valve 54aa is temporarily closed until the pressure becomes higher than the pressure on the accumulator 71a side. After that, when the driver operates the brake pedal 11 and the required braking force cannot be covered only by the regenerative braking force, the pressure on the hydraulic brake 38a side of the right front wheel RF is higher than the pressure on the low pressure accumulator 71a side. After the state is reached, the first pressure increasing valve 58aa is closed and the first pressure reducing valve 54aa is opened.

Therefore, the brake fluid does not flow from the low pressure accumulator 71a side to the hydraulic brake 38a side of the right front wheel RF via the first pressure reducing valve 54aa. Therefore, it is possible to omit the filter for preventing foreign matter from flowing from the first pressure reducing valve 54aa to the hydraulic brake 38a side from the low pressure accumulator 71a side.

<4. Processing example>
Next, the regenerative cooperation processing by the brake ECU 90 of the vehicle brake device 100 according to the present embodiment will be described. FIG. 7 is a flowchart showing an example of basic processing by the brake ECU 90. In the vehicle brake device 100, the hydraulic braking force of the hydraulic brake 38b of the left rear wheel LR and the hydraulic brake 38d of the right rear wheel RR are appropriately adjusted according to the fluctuation of the maximum regenerative braking force that can be regenerated by the regenerative brake. Controlled. Hereinafter, only the hydraulic brake 38a for the right front wheel RF and the hydraulic brake 38b for the left rear wheel LR on the first hydraulic circuit 28 side will be described, but the hydraulic pressure on the left front wheel LF on the second hydraulic circuit 30 side will be described. The brake 38c and the hydraulic brake 38d for the right rear wheel RR are also controlled in the same manner.

First, the brake ECU 90 determines whether or not the driver has requested the braking force (step S11). Specifically, the brake ECU 90 calculates the braking force required by the driver based on the stroke signal supplied from the electric booster 13. For example, the brake ECU 90 stores a map in which the correspondence relationship between the stroke amount and the required braking force is preset, and the brake ECU 90 calculates the required braking force based on the map and the stroke amount. When the calculated required braking force is a positive value, the brake ECU 90 determines that the driver has requested the braking force.

If the driver does not request the braking force (S11/No), the brake ECU 90 ends this routine and returns to step S11. On the other hand, when the driver requests the braking force (S11/Yes), the brake ECU 90 determines whether or not the hydraulic braking force distributed to the required braking force is necessary (step S13). For example, the brake ECU 90 calculates the hydraulic braking force command value as follows and determines whether or not the hydraulic braking force is necessary.

The brake ECU 90 stores a map in which the correspondence between the stroke amount of the booster 13 and the braking force required by the driver is preset, and the brake ECU 90 stores the braking force required by the driver based on the map and the stroke amount. To calculate. Further, the brake ECU 90 acquires information on the maximum regenerative braking force, which is the maximum value of the regenerative braking force that can be output at this time, from the motor ECU 110, and regenerates the smaller value of the maximum regenerative braking force and the required braking force. It is output to the motor ECU 110 as a braking force command value.

When the brake ECU 90 outputs the regenerative braking force command value to the motor ECU 110, this time, the brake ECU 90 acquires information on the actual regenerative braking force corresponding to the current actual regenerative braking force from the motor ECU 110. Then, the brake ECU 90 sets the value obtained by subtracting the regenerative braking force command value from the required braking force to the hydraulic pressure braking force command value, and the hydraulic pressure brake 38b of the left rear wheel LR is set so as to obtain the hydraulic pressure braking force command value. The target value of the pressure in the wheel cylinder of is calculated. When the calculated target value of the wheel cylinder pressure is a positive value, the brake ECU 90 determines that the hydraulic braking force is necessary.

When the hydraulic braking force is required (S13/Yes), the brake ECU 90 controls the hydraulic braking force generated in the hydraulic brake 38b of the left rear wheel LR (step S15). Specifically, the brake ECU 90 stores a map in which the correspondence between the wheel cylinder pressure and the caliper volume is preset, and the brake ECU 90 stores the map and the master cylinder pressure detected by the master cylinder hydraulic pressure sensor 24. , The caliper volume at present (actual caliper volume) and the target value of caliper volume (target caliper volume) are calculated based on the target value of the wheel cylinder pressure.

When the difference obtained by subtracting the actual caliper volume from the target caliper volume is a positive value, the brake ECU 90 opens the circuit control valve 36a, the first pressure reducing valve 54aa, and the second pressure increasing valve 58ba, while the intake The valve 34a, the first pressure increasing valve 58aa, and the second pressure reducing valve 54ba are closed, and the rotation speed of the pump motor 96 is controlled. The rotation speed of the pump motor 96 at this time is determined based on the difference value obtained by subtracting the actual caliper volume from the target caliper volume.

On the other hand, when the difference obtained by subtracting the actual caliper volume from the target caliper volume is a negative value, the brake ECU 90 maintains the circuit control valve 36a, the first pressure reducing valve 54aa, and the second pressure increasing valve 58ba in the open state. On the other hand, the suction valve 34a and the second pressure reducing valve 54ba are maintained in the closed state. In this state, the brake ECU 90 gradually increases the opening degree of the first pressure increasing valve 58aa and stops the pump motor 96. As a result, the first pressure reducing valve 54aa is maintained in the open state and the second pressure reducing valve 54ba is maintained in the closed state, so that the pressure reduction of the hydraulic brake 38b of the left rear wheel LR is performed by the first pressure increasing valve. Adjusted by 58aa. In this way, when the regenerative braking force is increased while the hydraulic braking force is being applied to the hydraulic brake 38b of the left rear wheel LR, the brake fluid supplied to the hydraulic brake 38b of the left rear wheel LR is increased. The liquid pressure can be reduced.

When the difference obtained by subtracting the actual caliper volume from the target caliper volume is a positive value, that is, when the actual caliper volume and the target caliper volume match, the brake ECU 90 closes the first pressure increasing valve 58aa, The first pressure reducing valve 54aa is opened. As a result, the hydraulic braking force of the hydraulic brake 38b for the left rear wheel LR can be retained.

On the other hand, when the hydraulic braking force is not necessary (S13/No), the brake ECU 90 controls only the regenerative braking force without generating the hydraulic braking force (step S17). Specifically, the brake ECU 90 maintains the circuit control valve 36a, the second pressure increasing valve 58ba, and the second pressure reducing valve 54ba in the open state, while the intake valve 34a, the first pressure increasing valve 58aa, and the first pressure reducing valve. The valve 54aa is kept closed. Further, the pump motor 96 is deactivated.

As a result, although the brake fluid flowing from the master cylinder 14 into the first hydraulic circuit 28 is supplied to the hydraulic brake 38b side of the left rear wheel LR, the brake fluid is low in pressure via the second pressure reducing valve 54ba. It is supplied to the accumulator 71a. Therefore, a hydraulic pressure corresponding to the reaction force of the low pressure accumulator 71a is generated in the hydraulic brake 38b of the left rear wheel LR, but the hydraulic braking force is not generated by the hydraulic pressure, or is set to an extremely small value. You can When the process of step S17 is once performed via step S15, an extremely small value of hydraulic pressure is also generated in the hydraulic brake 38a of the front right wheel RF.

After controlling the hydraulic braking force and the regenerative braking force in step S15 or controlling only the regenerative braking force in step S17, the brake ECU 90 determines whether or not to terminate the regenerative cooperation control (step S19). For example, the brake ECU 90 ends the regenerative cooperative control when it is determined that the maximum regenerative braking force has become zero or has a value close to zero based on the information obtained from the motor ECU 110. To determine. However, the method of determining whether or not to terminate the regenerative cooperation is not limited to this example.

If the brake ECU 90 does not determine to end the regenerative cooperative control (S19/No), the brake ECU 90 returns to step S11 and continues the process. On the other hand, when the brake ECU 90 determines to end the regenerative cooperative control (S19/Yes), the brake ECU 90 decreases the regenerative braking force while increasing the hydraulic braking force of the hydraulic brake 38a for the right front wheel RF (step S21). .. At this time, not only the hydraulic braking force of the hydraulic brake 38b of the left rear wheel LR is increased, but also the hydraulic braking force of the hydraulic brake 38a of the right front wheel RF is increased, so that the regenerative coordinated control is performed. Even after the end, the braking force is distributed to the four wheels, and the behavior of the vehicle can be stabilized.

Next, the brake ECU 90 determines whether or not the actual regenerative braking force has become zero based on the calculated regenerative braking force command value (step S23). When the actual regenerative braking force is not zero (S23/No), the brake ECU 90 returns to step S11 and continues the process. On the other hand, when the actual regenerative braking force becomes zero (S23/Yes), the brake ECU 90 ends the regenerative cooperative control (step S25).

The vehicle brake device 100 according to the present embodiment uses the hydraulic braking force of the hydraulic brake of the rear wheel, not the front wheel on which the regenerative braking force is exerted, when generating the hydraulic braking force during the regenerative cooperative control. adjust. Therefore, it is possible to suppress an unstable behavior of the vehicle such as understeer caused by an increase in the braking force ratio on the front wheel side. Further, since the unstable behavior of the vehicle can be suppressed, the regenerative braking force is not reduced in order to stabilize the behavior of the vehicle, and it is possible to suppress the decrease in energy utilization efficiency.

FIG. 8 is a timing chart showing an example of the operation of the vehicle brake device 100. In the graph of the braking force Tq and the time Time in FIG. 8, the regenerative braking force (corresponding to the regenerative braking command value) is shown by the solid line as the regenerative torque Tq_E, and the braking force required by the driver is shown by the broken line as the required torque Tq_D. Has been done. On the other hand, in the graph of the hydraulic pressure P of the hydraulic brake and the time Time, the hydraulic pressure Pw_R on the rear wheel side is shown by a solid line, and the hydraulic pressure Pw_F on the front wheel side is shown by a broken line.

As shown in the first region D in FIG. 8, while the required braking force Tq_D by the driver can be covered only by the regenerative braking force Tq_E, the first wheel-side first pressure increasing valve (EV_f) 58aa and the first pressure reducing valve (AV_f). 54aa is closed. Further, the second pressure increasing valve (EV_r) 58ba and the second pressure reducing valve (AV_r) 54ba on the rear wheel side are opened. Specifically, in the region D, the required braking force Tq_D due to the depression of the pedal increases, and the required regenerative braking force also increases accordingly. At this time, an extremely small hydraulic pressure corresponding to the reaction force of the low pressure accumulator 71a is generated in the hydraulic brake 38b of the left rear wheel LR, and the hydraulic braking force is not generated or is extremely small. The second pressure reducing valve 54ba on the rear wheel side is opened until the required regenerative braking force becomes larger than the maximum regenerative braking force and the target value of the pressure in the wheel cylinder of the hydraulic brake for the rear wheel becomes a positive value. The valve state is maintained. As a result, the brake fluid corresponding to the pedal operation amount is discharged to the low pressure accumulator 71a.

When the required regenerative braking force becomes larger than the maximum regenerative braking force and the driver's required braking force Tq_D cannot be covered only by the regenerative braking force Tq_E, the second pressure reducing valve 54ba on the rear wheel side is closed. A hydraulic braking force corresponding to the pedal operation amount is generated (region B). At this time, when the required regenerative braking force decreases to the maximum regenerative braking force again, the first pressure reducing valve 54aa on the front wheel side is closed and the second pressure reducing valve 54ba on the rear wheel side is opened. .. As a result, the brake fluid corresponding to the pedal operation amount is discharged to the low pressure accumulator 71a (area D).

When the maximum regenerative braking force starts to increase, the difference between the target caliper volume and the actual caliper volume becomes negative, so that the opening degree of the first pressure increasing valve (EV_f) 58aa on the front wheel side is continuously increased little by little. , The first pressure reducing valve 54aa on the front wheel side is opened (region C). When the maximum regenerative braking force stops increasing, the front wheel-side first pressure increasing valve 58aa is maintained in the closed state, and the front wheel-side first pressure reducing valve 54aa is maintained in the open state (region B).

After that, when the maximum regenerative braking force begins to decrease, the front wheel side first pressure reducing valve 54aa is kept closed and the front wheel side first pressure increasing valve 58aa is adjusted while the front wheel side opening degree is adjusted. The hydraulic braking force of the hydraulic brake 38a is increased (area E). At this time, the second pressure reducing valve (AV_r) 54ba on the rear wheel side is maintained in the closed state, and the second pressure increasing valve (EV_r) 58ba on the rear wheel side is maintained in the open state. The hydraulic brake 38a and the hydraulic brake 38b on the rear wheel side have the same pressure. After that, the first pressure increasing valve 58aa on the front wheel side is fully opened, and the hydraulic pressure is controlled only by the pump 44a. When the hydraulic braking force of the front wheel side hydraulic brake 38a and the rear wheel side hydraulic brake 38b are both zero (area D), when transitioning to the area E, the front wheel side first The pressure increasing valve 58aa is quickly fully opened and the hydraulic pressure is controlled only by the pump 44a.

Then, when the hydraulic pressure of the hydraulic brake 38a on the front wheel side and the hydraulic pressure of the hydraulic brake 38b on the rear wheel become the hydraulic pressure corresponding to the braking force Tq_D requested by the driver, the operation of the pump 44a is stopped. (Region A). During this period, the opening degree of the first pressure increasing valve 58aa on the front wheel side is controlled based on the volume states of the front wheel hydraulic brake 38a and the rear wheel hydraulic brake 38b, and the respective hydraulic brakes 38a, 38b are controlled. Fluid pressure is adjusted.

So far, the basic operation of the processing by the brake ECU 90 of the vehicle brake device 100 according to the present embodiment has been described. Hereinafter, a process for suppressing the flow of the brake fluid from the low pressure accumulator 71a side to the hydraulic brake 38a side via the first pressure reducing valve 54aa of the hydraulic brake 38a for the right front wheel RF will be described.

FIG. 9 shows a flowchart of a process performed when the process shifts to the process of step S15 after it is determined that the hydraulic braking force is necessary in step S13 of the flowchart shown in FIG. Further, FIG. 10 shows a timing chart when the processing is executed. 9 and 10, a period in which the driver's required braking force can be covered only by the regenerative braking force is expressed as "OS1", and the driver's required braking force is generated by being distributed to the regenerative braking force and the hydraulic braking force. The period is described as "OS2".

The first pressure increasing valve (EV_f) 58aa and the first pressure reducing valve (AV_f) 54aa are maintained in the closed state during a period in which the driver's required braking force can be covered only by the regenerative braking force (period until time ti1). The second pressure increasing valve (EV_r) 58ba and the second pressure reducing valve (AV_r) 54ba are maintained in the open state. During this period, the pump 44a is stopped. When the braking force required by the driver cannot be covered by only the regenerative braking force (time ti1), the brake ECU 90 closes the second pressure reducing valve 54ba. As a result, the hydraulic pressure Pw_R of the hydraulic brake 38b of the left rear wheel LR starts to rise. Further, at time ti1, the brake ECU 90 opens the first pressure increasing valve 58aa. As a result, the hydraulic pressure Pw_F of the hydraulic brake 38a for the right front wheel RF also starts to rise. At time ti1, the pump 44a is driven as needed.

After time ti1, the brake ECU 90 determines whether or not the hydraulic pressure Pw_F of the hydraulic brake 38a for the right front wheel RF is equal to or higher than the pressure P_a on the low pressure accumulator 71a side (step S31). The hydraulic pressure Pw_F of the hydraulic brake 38a for the right front wheel RF can be calculated, for example, based on the flow rate of the brake fluid supplied to the hydraulic brake 38a for the right front wheel RF. As the pressure P_a on the low pressure accumulator 71a side, a value preset according to the spring constant of the spring of the low pressure accumulator 71a is used.

The pressure P_a on the low-pressure accumulator 71a side may be an actual measurement value or a model value, but the maximum value preset according to the spring constant of the spring of the low-pressure accumulator 71a is used to reduce the pressure on the low-pressure accumulator 71a side. It is possible to reduce the risk that the first pressure reducing valve 54aa is opened in a state where the pressure is higher than the hydraulic pressure Pw_F of the hydraulic brake 38a for the front right wheel RF.

During the period from time ti1 to time ti2, since the hydraulic pressure Pw_F of the hydraulic brake 38a for the right front wheel RF is less than the pressure P_a on the low pressure accumulator 71a side (S31/No), the brake ECU 90 closes the first pressure reducing valve 54aa. The valve state is maintained (step S35). The brake ECU 90 repeats the processing of steps S31 to S35 until the hydraulic pressure Pw_F of the hydraulic brake 38a for the right front wheel RF becomes equal to or higher than the pressure P_a on the low pressure accumulator 71a side.

At time ti2, when the hydraulic pressure Pw_F of the hydraulic brake 38a for the right front wheel RF becomes equal to or higher than the pressure P_a on the low-pressure accumulator 71a side (S31/Yes), the brake ECU 90 opens the first pressure reducing valve 54aa and opens the first pressure reducing valve 54aa. The pressure boosting valve 58aa is closed. After time ti2, the brake ECU 90 drives the pump 44a as needed. As a result, the brake fluid does not flow through the first pressure reducing valve 54aa from the low pressure accumulator 71a side to the hydraulic brake 38a side of the right front wheel RF, but from the hydraulic brake 38a side of the right front wheel RF to the low pressure accumulator 71a side. Flows.

After that, the opening degree of the first pressure increasing valve 58aa is adjusted according to the target value of the pressure in the wheel cylinder of the hydraulic brake 38b for the left rear wheel LR, and the hydraulic brake generated in the hydraulic brake 38b for the left rear wheel LR is adjusted. The force is adjusted (step S15 in the flowchart shown in FIG. 7). In this state, the brake fluid supplied to the hydraulic brake 38a for the front right wheel RF is supplied to the low pressure accumulator 71a via the first pressure reducing valve 54aa, so that the hydraulic brake 38a for the front right wheel RF has a low pressure. A relatively small hydraulic braking force is generated according to the spring force of the accumulator 71a.

FIG. 11 is a timing chart of a reference example in which the first pressure reducing valve 54aa is immediately opened when the driver's required braking force cannot be covered by only the regenerative braking force. At time ti1 when the braking force required by the driver cannot be covered by only the regenerative braking force, the second pressure reducing valve 54ba is closed and the first pressure reducing valve 54ba is closed in order to increase the hydraulic pressure Pw_R of the hydraulic brake 38b of the left rear wheel LR. The pressure reducing valve 54aa is opened. In this case, since the hydraulic pressure Pw_F of the hydraulic brake 38a for the right front wheel RF is lower than the pressure P_a on the low pressure accumulator 71a side, the brake fluid is applied to the first pressure reducing valve 54aa from the low pressure accumulator 71a side to the right front wheel RF side. It will flow to the hydraulic brake 38a side.

As described above, in the vehicle brake device 100 according to the present embodiment, when the state in which only the regenerative braking force is generated is changed to the state in which the hydraulic braking force is generated together with the regenerative braking force, the right front wheel is When the hydraulic pressure of the RF hydraulic brake 38a becomes equal to or higher than the pressure on the low pressure accumulator 71a side, the first pressure reducing valve 54aa is opened. Therefore, the brake fluid does not flow from the low-pressure accumulator 71a side to the hydraulic brake 38a side of the right front wheel RF via the first pressure reducing valve 54aa, and the filter corresponding to the flow is removed from the first pressure reducing valve 54aa. It can be omitted.

FIG. 12 is a flowchart of a process performed when the brake pedal is suddenly released in the state where the braking force is distributed to the regenerative braking force and the hydraulic braking force in step S15 of the flowchart shown in FIG. 7. Show.

The brake ECU 90 determines whether or not the brake pedal 11 is suddenly released while the hydraulic braking force is being generated (step S41). For example, based on the stroke signal supplied from the electric booster 13, the brake ECU 90 determines whether the increase rate of the stroke amount is negative and the master cylinder pressure is lower than the pressure in the low pressure accumulator 71a. To determine. The master cylinder pressure is detected based on the sensor value of the master cylinder hydraulic pressure sensor 24. As the pressure P_a on the low-pressure accumulator 71a side, a value preset according to the spring constant of the spring of the low-pressure accumulator 71a is used. As described above, the pressure P_a on the low pressure accumulator 71a side may be a measured value or a model value.

When the brake ECU 90 determines that the brake pedal 11 is suddenly released (S41/Yes), the first pressure reducing valve 54aa is closed (step S43). On the other hand, when the brake ECU 90 does not determine that the brake pedal 11 is suddenly released (S41/No), the first pressure reducing valve 54aa is opened or maintained in the open state (step S45). The brake ECU 90 repeatedly executes the processing of these steps S41 to S45. In addition, after closing the first pressure reducing valve 54aa in step S43, the first pressure reducing valve 54aa may be opened after a lapse of a time previously obtained by simulation and set to an appropriate time.

As described above, in the vehicle brake device 100 according to the present embodiment, when the brake pedal 11 is suddenly released in the state where the regenerative braking force and the hydraulic braking force are generated, the first pressure reducing valve 54aa. Is closed. After that, when the hydraulic pressure of the hydraulic brake 38a for the right front wheel RF becomes higher than the pressure on the low pressure accumulator 71a side, the first pressure reducing valve 54aa is opened again. Therefore, the brake fluid does not flow from the low-pressure accumulator 71a side to the hydraulic brake 38a side of the right front wheel RF via the first pressure reducing valve 54aa, and the filter corresponding to the flow is removed from the first pressure reducing valve 54aa. It can be omitted.

As described above, according to the vehicle brake device 100 of the present embodiment, it is possible to reduce the number of filters provided in the pressure reducing valve of the hydraulic brake on the front wheel side. Therefore, the manufacturing cost can be reduced. Moreover, since the number of parts is reduced, it is possible to prevent an increase in variations of the pressure reducing valve due to differences in vehicles and brake systems.

Further, if a filter for collecting foreign matters moving from the low pressure accumulator 71a side to the front wheel side hydraulic brake 38a side becomes unnecessary, the hydraulic pressure of the front wheel can be reduced as much as possible without generating hydraulic braking force on the rear wheel. Adjusting the braking force to match the sum of the hydraulic braking force and the regenerative braking force with the braking force required by the driver Without changing the configuration of the braking system, the control to adjust the hydraulic braking force of the rear wheels is executed. can do.

The preferred embodiments of the present invention have been described above in detail with reference to the accompanying drawings, but the present invention is not limited to these examples. It is obvious that a person having ordinary knowledge in the technical field to which the present invention pertains can come up with various changes or modifications within the scope of the technical idea described in the claims. Of course, it is understood that these also belong to the technical scope of the present invention.

For example, in the hydraulic circuit 1 described in the above embodiment, the first hydraulic circuit 28 and the second hydraulic circuit 30 are provided with the dampers 73a and 73b, respectively, but the dampers 73a and 73b are omitted. It may have been done.

Further, in the above embodiment, the master cylinder pressure detected by the master cylinder hydraulic pressure sensor 24 is used in calculating the actual caliper volume, but the present invention is not limited to this example. If the actual caliper volume can be calculated, a wheel cylinder hydraulic pressure sensor is provided between the wheel cylinder of the hydraulic brake 38a on the front wheel side and the first pressure increasing valve 58aa, and the wheel cylinder pressure is used instead of the master cylinder pressure. May be.

Further, in the above embodiment, the hydraulic pressure of the hydraulic brake 38a on the front wheel side is calculated based on the flow rate of the brake fluid supplied to the hydraulic brake 38a, but the present invention is not limited to this example. A wheel cylinder hydraulic pressure sensor may be provided between the wheel cylinder of the hydraulic brake 38a on the front wheel side and the first pressure increasing valve 58aa to detect the hydraulic pressure of the hydraulic brake 38a on the front wheel side.

Further, in the above-described embodiment, when reducing the hydraulic pressure of the hydraulic brake 38a on the front wheel side, the brake ECU 90 continuously and gradually increases the opening degree of the first pressure increasing valve 58aa on the front wheel side and then the front wheel side. Although the first pressure reducing valve 54aa is opened, the present invention is not limited to this example. If the hydraulic pressure of the hydraulic brake 38a on the front wheel side can be continuously and gradually reduced, after opening the first pressure reducing valve 54aa on the front wheel side, the opening degree of the first pressure increasing valve 58aa on the front wheel side can be increased. May be.

28... 1st hydraulic circuit, 30... 2nd hydraulic circuit, 34a... Intake valve, 36a... Circuit control valve, 38a... 1st hydraulic brake, 38b... 2nd hydraulic brake, 44a... Pump , 54aa... First pressure reducing valve, 54ba... Second pressure reducing valve, 58aa... First pressure increasing valve (regulating valve), 58ba... Second pressure increasing valve (regulating valve), 71a... Low pressure accumulator, 96... Pump motor , 100... Vehicle braking device, 121... Battery, 123... Inverter, 125... Driving motor

Claims (6)

A first hydraulic brake (38a) that generates hydraulic braking force on the front wheels (RF), a second hydraulic brake (38b) that generates hydraulic braking force on the rear wheels (LR), and a front wheel (RF). A regenerative brake (125) for converting the kinetic energy of) to generate a regenerative braking force, and capable of distributing the braking force to the hydraulic braking force and the regenerative braking force.
A first regulating valve (58aa) for continuously regulating the flow rate of the brake fluid supplied to the first hydraulic brake (38a);
A second adjusting valve (58ba) for continuously adjusting the flow rate of the brake fluid supplied to the second hydraulic brake (38b);
A first pressure reducing valve (54aa) for reducing the hydraulic braking force of the first hydraulic brake (38a);
A second pressure reducing valve (54ba) for reducing the hydraulic braking force of the second hydraulic brake (38b);
An accumulator (71a) to which brake fluid is supplied when the pressure is reduced by the first pressure reducing valve (54aa) or the second pressure reducing valve (54ba);
A controller (90) for controlling the first regulating valve (58aa), the first pressure reducing valve (54aa), the second regulating valve (58ba) and the second pressure reducing valve (54ba). Prepare,
The control device (90) is
The vehicle brake device, wherein the first pressure reducing valve (54aa) is opened in a state where the pressure on the first hydraulic brake (38a) side is higher than the pressure on the accumulator (71a) side. .. The control device (90) is
While only generating the regenerative braking force, the first regulating valve (58aa) and the first pressure reducing valve (54aa) are closed, while the second regulating valve (58ba) and the second regulating valve (58ba) are closed. The pressure reducing valve (54ba) is opened, and the brake fluid is supplied to the accumulator (71a) via the second adjusting valve (58ba) and the second pressure reducing valve (54ba),
While the hydraulic braking force is generated in combination with the regenerative braking force, the second pressure reducing valve (54ba) is closed, while the first pressure reducing valve (54aa) and the second regulating valve (58ba). ) Is opened and the brake fluid is supplied to the second hydraulic brake (38b) while the first regulator valve (58aa) is operated by the first regulator valve (58aa) and the first regulator valve (58aa). The hydraulic braking force of the rear wheels (LR) is adjusted by adjusting the flow rate of the brake fluid supplied to the accumulator (71a) via the pressure reducing valve (54aa). Brake system for vehicles. When switching from the state of generating only regenerative braking force to the state of generating regenerative braking force and hydraulic braking force,
The control device (90) is
The first pressure reducing valve (54aa) is opened when the pressure on the side of the first hydraulic brake (38a) becomes larger than the pressure on the side of the accumulator (71a). The vehicle brake device according to claim 2. When the brake pedal (11) is released from the state where the regenerative braking force and the hydraulic braking force are generated,
The control device (90) is
The first pressure reducing valve (54aa) is opened when the pressure on the side of the first hydraulic brake (38a) becomes larger than the pressure on the side of the accumulator (71a). The vehicle brake device according to claim 2. The control device (90) is
A master cylinder that stores the brake fluid and the return speed of the brake pedal (11) depending on whether the pressure on the first hydraulic brake (38a) side is higher than the pressure on the accumulator (71a) side. The vehicle brake device according to claim 4, wherein the determination is made based on the pressure in (14). A first hydraulic brake (38a) that generates hydraulic braking force on the front wheels (RF), a second hydraulic brake (38b) that generates hydraulic braking force on the rear wheels (LR), and a front wheel (RF). ), a regenerative brake (125) for generating a regenerative braking force, and a first regulating valve () for continuously regulating the flow rate of the brake fluid supplied to the first hydraulic brake (38a). 58aa), a second adjusting valve (58ba) for continuously adjusting the flow rate of the brake fluid supplied to the second hydraulic brake (38b), and the hydraulic pressure of the first hydraulic brake (38a). A first pressure reducing valve (54aa) for reducing the braking force, a second pressure reducing valve (54ba) for reducing the hydraulic braking force of the second hydraulic brake (38b), and the first pressure reducing valve ( 54aa) or an accumulator (71a) to which brake fluid is supplied when the pressure is reduced by the second pressure reducing valve (54ba), the first adjusting valve (58aa), the first pressure reducing valve (54aa), the second pressure reducing valve (54aa). A control device (90) for controlling the adjusting valve (58ba) and the second pressure reducing valve (54ba), and capable of distributing the braking force to the hydraulic braking force and the regenerative braking force ( In the control method of 100),
The control device (90) is
The vehicle brake device, wherein the first pressure reducing valve (54aa) is opened in a state where the pressure on the first hydraulic brake (38a) side is higher than the pressure on the accumulator (71a) side. Control method.

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