JP5724707B2 - Brake control device - Google Patents

Description

  The present invention relates to a brake control device including a control hydraulic circuit that regulates hydraulic pressure of hydraulic fluid pressurized by a power hydraulic pressure source by a linear control valve and transmits the pressure to a wheel cylinder.

  Conventionally, the hydraulic pressure of hydraulic fluid pressurized by the pedal pressure of the brake pedal is transmitted to the wheel cylinder, and the hydraulic pressure of hydraulic fluid pressurized by the power hydraulic pressure source is regulated by a linear control valve. The control hydraulic pressure circuit that transmits to the wheel cylinder is provided in parallel, and in normal times, the control hydraulic pressure mode that uses the control hydraulic pressure circuit is selected. A brake control device that switches to a backup mode using a hydraulic circuit is known.

  In the control hydraulic pressure mode, the target hydraulic pressure is calculated based on the required braking force generated by the brake control device, and the opening degree of the linear control valve is controlled so that the target hydraulic pressure is transmitted to the wheel cylinder. Such a brake control system that does not use the depression force of the brake pedal is generally called a brake-by-wire system.

  For example, in the brake control device proposed in Patent Document 1, a pedal force hydraulic circuit is connected to a master channel that transmits hydraulic pressure from a master cylinder to each wheel cylinder of the front wheel, and from the regulator to each wheel cylinder of the rear wheel. It consists of two systems with a regulator channel that transmits pressure. The master channel and the regulator channel are provided with a master cut valve and a regulator cut valve, respectively, and are connected to the main channel. The main channel is provided with a communication valve (described as a separation valve in Patent Document 1) for switching communication / blocking between the master channel and the regulator channel. The power hydraulic pressure source is connected to the main flow path via a linear control valve.

  In the control hydraulic pressure mode, the master cut valve and the regulator cut valve are closed, and the opening degree of the linear control valve is controlled in a state where the communication valve is opened. As a result, a common control hydraulic pressure is transmitted to the front and rear wheel cylinders. On the other hand, in the backup mode, the master cut valve and the regulator cut valve are opened, and the communication valve and the linear control valve are closed. Thereby, the hydraulic pressure of the master cylinder is transmitted to each wheel cylinder of the front wheel, and the hydraulic pressure of the regulator is transmitted to each wheel cylinder of the rear wheel.

  In the brake control device disclosed in Patent Document 1, when the state where the communication valve is clogged with foreign matter is detected, the control hydraulic pressure mode is switched to the backup mode. Then, after confirming that the vehicle is stopped, the working fluid was passed through the communication valve in the direction opposite to the direction in which the foreign material was clogged, and the foreign material clogged in the communication valve was removed by the flow of the working fluid. If is confirmed, cancel the backup mode.

JP 2008-302867 A

  In the above-described brake control device, when a situation where a foreign object is clogged is detected, the mode is always switched to the backup mode. When the communication valve is clogged with foreign matter, there is no problem even if it is immediately switched to the backup mode, but depending on where the foreign matter is clogged, there is a case where it is not desired to switch to the backup mode as much as possible.

  Each wheel cylinder is connected to an ABS pressure reducing valve for lowering the hydraulic pressure of the wheel cylinder, and this case corresponds to a case where foreign matter clogging occurs in the ABS pressure reducing valve. When the control hydraulic pressure mode is switched to the backup mode, each wheel cylinder is disconnected from the power hydraulic pressure source, the front wheel cylinder communicates with the master cylinder, and the rear wheel cylinder communicates with the regulator. Therefore, for example, when a foreign object is clogged in one of the front wheel ABS pressure reducing valves, the front wheel cylinder is supplied with hydraulic fluid from the master cylinder, but the hydraulic fluid leaks from the ABS pressure reducing valve and flows into the reservoir. Since it flows in the road, there is a possibility that sufficient hydraulic pressure cannot be generated in the wheel cylinder of the front wheel.

  On the other hand, since the power hydraulic pressure source is configured to be able to supply hydraulic fluid to the four-wheel wheel cylinder, the flow rate of hydraulic fluid that can be supplied from the linear control valve is large. For this reason, even if a single wheel ABS pressure reducing valve is clogged with foreign matter and the hydraulic fluid leaks into the reservoir, the hydraulic fluid can be supplied from the linear control valve at a flow rate sufficient to compensate for the leakage. Therefore, an appropriate wheel cylinder pressure can be generated for all four wheels.

  For these reasons, it is not desirable to switch to the backup mode as much as possible for an abnormal leakage of the ABS pressure reducing valve.

  The present invention has been made to solve the above-described problem, and aims to reduce the probability of switching to the backup mode as much as possible.

  A feature of the present invention that solves the above-described problem is that a plurality of wheel cylinders (42) that are provided in each of a plurality of wheels and receive a hydraulic pressure of hydraulic fluid to apply braking force to the wheels, and a pedaling force that is input to a brake pedal A pedal force hydraulic circuit (LF, LR) that transmits the hydraulic pressure of the pressurized hydraulic fluid to the plurality of wheel cylinders, and a power hydraulic pressure source (30) that pressurizes the hydraulic fluid regardless of the operation of the brake pedal. A control hydraulic circuit (L1) for adjusting the hydraulic pressure of the hydraulic fluid pressurized by the power hydraulic pressure source by means of a linear control valve (67, 68) and transmitting it to the plurality of wheel cylinders; and the control fluid Mode switching means (50, 100) for switching between a control hydraulic pressure mode for generating a braking force on the wheel using a pressure circuit and a backup mode for generating a braking force on the wheel using the pedal force hydraulic pressure circuit; Ho A pressure reducing valve (63) which is provided corresponding to the cylinder and reduces the wheel cylinder pressure by returning the working fluid of the wheel cylinder to the reservoir flow path, and pressure reducing valve abnormality inspection means (100, 100) for inspecting leakage abnormality of the pressure reducing valve. S11 to S25)) and the control hydraulic pressure to remove foreign matter clogged in the pressure reducing valve without switching to the backup mode when the pressure reducing valve abnormality inspection means detects the leakage abnormality of the pressure reducing valve. A refresh means (100, S30) for performing a refresh process, which is a process of passing hydraulic fluid through the pressure reducing valve using a circuit, and a pressure reducing valve abnormality for rechecking the leakage abnormality of the pressure reducing valve after the refresh process by the refresh means. Re-inspection means (100, S90) and pressure-reducing valve abnormality re-inspection related to refresh processing by the refresh means If the leakage abnormality of the pressure reducing valve is detected by means lies in the fact that a mode shift command means for shifting to said backup mode (100, S96).

  The brake control device of the present invention includes a pedal force hydraulic pressure circuit and a control hydraulic pressure circuit, and a control hydraulic pressure mode in which a braking force is generated on a wheel using the control hydraulic pressure circuit by a mode switching unit, and a pedal pressure hydraulic pressure It is configured to be switched between a backup mode for generating braking force on the wheels using a pressure circuit. The pedal effort hydraulic circuit transmits hydraulic pressure of hydraulic fluid pressurized by the pedal effort input to the brake pedal to the plurality of wheel cylinders. In this case, for example, the pedal force hydraulic circuit is constituted by a front wheel pedal hydraulic circuit and a rear wheel pedal hydraulic circuit that are independent of each other, and the wheel cylinder provided on the front wheel has hydraulic fluid from the front wheel hydraulic circuit. The hydraulic pressure of the hydraulic fluid may be transmitted from the rear wheel pedal pressure hydraulic circuit to the wheel cylinder provided on the rear wheel.

  On the other hand, the control hydraulic circuit regulates the hydraulic pressure of the hydraulic fluid pressurized by the power hydraulic pressure source that pressurizes the hydraulic fluid regardless of the operation of the brake pedal, and transmits the hydraulic pressure to the plurality of wheel cylinders. . Therefore, the hydraulic pressure transmitted to the wheel cylinder can be arbitrarily adjusted by energizing the linear control valve. The linear control valve may be provided in common for each wheel cylinder, or may be provided independently for each wheel cylinder.

  For example, in an electric vehicle or a hybrid vehicle, not only brake braking by hydraulic pressure but also regenerative braking is performed in which a motor is generated by the rotational force of wheels and the generated power is regenerated in a battery. When performing such regenerative braking, an appropriate braking force can be generated in the vehicle by setting the braking force obtained by removing the regenerative braking amount from the necessary total braking force to the brake braking force based on the hydraulic pressure. Therefore, the control hydraulic circuit is suitable for performing so-called brake regeneration cooperative control combined with regenerative braking.

  Each wheel is provided with a pressure reducing valve for reducing the wheel cylinder pressure. This pressure reducing valve is used for ABS control (anti-lock brake control), for example. The pressure reducing valve abnormality inspection means inspects for a leakage abnormality of the pressure reducing valve. For example, when a foreign object is caught in the pressure reducing valve and a valve closing failure occurs, the hydraulic pressure of the wheel cylinder connected to the pressure reducing valve decreases. The pressure reducing valve abnormality inspection means inspects the pressure abnormality of the pressure reducing valve by detecting such a fluid pressure abnormality.

  In the conventional device, if any abnormality occurs in the brake control device, the braking force is applied to the wheel using the pedal force hydraulic circuit from the control hydraulic pressure mode in which the braking force is generated on the wheel using the control hydraulic circuit. It is configured to switch to the backup mode to be generated. This is because in the backup mode, even if the control system breaks down, the braking force can be generated by using the pedal force of depressing the driver's brake pedal.

  However, in the case where a leakage abnormality of the pressure reducing valve occurs, it may not be possible to generate a sufficient hydraulic pressure in the wheel cylinder when switching to the backup mode. In particular, when a pedal force hydraulic circuit is configured to supply hydraulic fluid pressurized by the pedal force input to the brake pedal from a separate hydraulic circuit to the wheel cylinder provided on the front wheel and the wheel cylinder provided on the rear wheel When a leakage abnormality occurs in one pressure reducing valve, it becomes difficult to supply an amount of hydraulic fluid sufficient to compensate for the leakage from one hydraulic circuit.

  On the other hand, regarding the leakage abnormality of the pressure reducing valve, if the cause is due to clogging of foreign matter, the foreign matter can be removed by passing hydraulic fluid through the pressure reducing valve to eliminate the leakage abnormality. Therefore, the present invention includes a refresh means, a pressure reducing valve abnormality re-inspection means, and a mode transition command means.

  When the pressure reducing valve abnormality inspecting means detects a leakage abnormality of the pressure reducing valve, the refresh means performs a process of passing the working fluid through the pressure reducing valve using the control hydraulic circuit without switching to the backup mode, that is, a refresh process. Do. As a result, the foreign matter clogged in the pressure reducing valve flows together with the working fluid. The leakage abnormality of the pressure reducing valve is not limited to the clogging of foreign matter. Therefore, the pressure reducing valve abnormality re-inspection means re-inspects the pressure abnormality of the pressure reducing valve after the refresh process by the refresh means.

  The mode transition command means causes the mode switching means to shift to the backup mode when the pressure reducing valve abnormality re-inspecting means related to the refreshing process of the pressure reducing valve by the refresh means is detected. Give a command. In other words, when the pressure reducing valve refreshes by the refreshing means by the refreshing means and the pressure reducing valve returns to normal, the mode is not shifted to the back mode.

  As described above, according to the present invention, when a leakage abnormality of the pressure reducing valve is detected, instead of immediately switching to the backup mode, a refresh process is performed to try to remove the foreign matter, and the pressure reducing valve still does not return to normal. Switch to backup mode only if. Therefore, the probability of shifting to the backup mode due to abnormality determination can be reduced. This improves the convenience of the driver.

  The pressure reducing valve abnormality inspection means does not need to inspect the leakage abnormality for all the pressure reducing valves, and may inspect the leakage abnormality only for a predetermined specific pressure reducing valve. For example, the configuration may be such that only the front-wheel pressure reducing valve that has a large valve opening area and a large influence of the hydraulic fluid leakage abnormality is examined. Further, the refresh means is not limited to performing the refresh process only for the pressure reducing valve in which the leakage abnormality is detected, but may be a means for performing the refresh process for all the pressure reducing valves.

  Another feature of the present invention resides in that the refresh means executes the refresh process once per trip with a period from system startup to system shutdown as one trip.

  When the refresh process is performed, the sound of the hydraulic fluid flowing through the control hydraulic circuit (particularly the sound when passing through the linear control valve) is generated. Moreover, if the cause of the leakage abnormality of the pressure reducing valve is due to clogging of foreign matter, the clogging of foreign matter can be sufficiently eliminated by a single refresh process. Therefore, in the present invention, the refresh process is executed once per trip with a period from system start to system stop (from start to stop of the brake control device) as one trip. Thereby, generation | occurrence | production of the flow sound of a hydraulic fluid can be suppressed. In addition to the refresh unit, for example, a regular refresh unit may be provided that performs the refresh process once every n trips (n: natural number) regardless of whether there is a leakage abnormality of the pressure reducing valve. In this case, the refresh process can be performed at an appropriate frequency with the occurrence of flowing sound suppressed.

  Another feature of the present invention is that the control hydraulic circuit is connected to the power hydraulic pressure source and has a main flow path (52) provided with the linear control valve, and branches from the main flow path to each wheel cylinder. An individual flow path (51) to be connected; and an open / close valve (61) for opening and closing the individual flow path, wherein the refresh means opens the open / close valve (61) one by one, The refresh process is performed one by one for all the pressure reducing valves.

  The refresh process is performed by flowing hydraulic fluid to the pressure reducing valves using a control hydraulic pressure circuit, but when hydraulic fluid is simultaneously flowed to the pressure reducing valves of all wheels, the total flow rate flowing to each pressure reducing valve is linearly controlled. Will flow to the valve. For this reason, a loud noise is generated when the hydraulic fluid passes through the linear control valve. On the other hand, the foreign substance removal performance depends on the flow rate and flow rate of the working fluid that passes through each pressure reducing valve. Therefore, in the present invention, the refresh means does not perform the refresh process for all the pressure reducing valves at the same time, but performs the refresh process for each wheel. In this case, the refresh process can be performed one wheel at a time by closing the individual flow paths leading to the pressure reducing valves other than the pressure reducing valves to be refreshed by the on-off valves. As a result, a flow rate necessary for removing foreign matter can be allowed to flow through the pressure reducing valve while keeping the flow rate flowing through the linear control valve low. As a result, according to the present invention, it is possible to achieve both the reduction of the hydraulic fluid sound and the improvement of the foreign matter removal performance.

  Another feature of the present invention is that, when the hydraulic pressure output from the power pressurization source is lower than a specified pressure, the refresh means outputs a hydraulic pressure output from the power pressurization source equal to or higher than a predetermined pressure. The liquid pressure securing means (S31) that waits until it rises is provided.

  The foreign matter removal performance of the pressure reducing valve depends on the flow rate and flow rate of the working fluid flowing through the pressure reducing valve. Therefore, when the hydraulic pressure output from the power pressurization source does not reach a sufficient pressure necessary for removing foreign matter, a desired foreign matter removing performance cannot be obtained. Therefore, in the present invention, the refresh means is configured to increase the hydraulic pressure output from the power pressurization source to a predetermined pressure or higher when the hydraulic pressure output from the power pressurization source has decreased below a specified pressure. A hydraulic pressure securing means for waiting is provided.

  For example, when the hydraulic pressure output from the power pressurization source is reduced to a specified pressure or less when the refresh process is started, the liquid pressure securing unit is configured to reduce the hydraulic pressure output from the power pressurization source to a predetermined pressure. It waits until it rises above (= specified pressure or more). When the power pressurization source includes a pump that increases the hydraulic fluid pressure and an accumulator that stores hydraulic pressure energy of the increased hydraulic fluid, and the pump is driven so that the accumulator pressure becomes the target pressure, The liquid pressure securing means may wait until the accumulator pressure reaches a predetermined pressure or higher by the operation of the pump. The refresh means starts the refresh process when the accumulator pressure reaches a predetermined pressure or higher.

  In addition, the liquid pressure securing unit may, for example, perform the refresh process not only at the start of the refresh process but also when the hydraulic pressure output from the power pressurization source is lower than a specified pressure during the execution of the refresh process. May be suspended, and the system may wait until the hydraulic pressure output from the power pressurization source rises above a predetermined pressure. In this case, the predetermined pressure may be set to a value larger than the specified pressure.

  As a result, according to the present invention, the refresh process can be performed appropriately, and a good foreign matter removal performance can be obtained.

  Another feature of the present invention is that the refresh means opens the linear control valve (67) so that the hydraulic fluid output from the power pressurization source flows to the pressure reducing valve at the start of the refresh process. And a valve opening current control means (S43) for controlling the current of the linear control valve so as to gradually increase the current value from a predetermined current value lower than the current value required to open the linear control valve. That is.

  The refresh means opens the linear control valve so that the hydraulic fluid output from the power pressurization source flows to the pressure reducing valve when the refresh process is started, but when the linear control valve is instantaneously opened, A loud noise is generated. The magnitude of this operating noise is proportional to the change in the flow rate of the hydraulic fluid. Therefore, in the present invention, the valve opening current control means gradually increases the current value from a predetermined current value lower than the current value necessary to open the linear control valve at the start of the refresh process. Controls the current of the linear control valve. As a result, the linear control valve can be opened smoothly, and the operating noise at the start of the refresh process can be reduced. The linear control valve includes a pressure-increasing linear control valve that increases the hydraulic pressure of the hydraulic fluid that is transmitted to the wheel cylinder, and a pressure-reduction linear control valve that decreases the hydraulic pressure of the hydraulic fluid that is transmitted to the wheel cylinder. In this case, the pressure-increasing linear control is performed so that the current value is gradually increased from a predetermined current value lower than the current value necessary to open the pressure-increasing linear control valve with the pressure-reducing linear control valve closed. The valve current may be controlled.

  Another feature of the present invention is that the refresh means closes the linear control valve (67) so as to stop the working fluid flowing from the power pressurization source to the pressure reducing valve at the end of the refresh process. A valve closing current control means for controlling the current of the linear control valve so as to gradually decrease the current value from a predetermined current value higher than a current value required to open or close the linear control valve. (S43).

  The refresh means closes the linear control valve so as to stop the hydraulic fluid flowing from the power pressurization source to the pressure reducing valve when the refresh process is finished, but when the linear control valve is instantaneously closed, A loud operating noise is generated at the moment. The magnitude of this operating noise is proportional to the change in the flow rate of the hydraulic fluid. Therefore, in the present invention, the valve closing current control means gradually decreases the current value from a predetermined current value higher than the current value necessary to open or close the linear control valve at the end of the refresh process. To control the current of the linear control valve. As a result, the linear control valve can be closed smoothly, and the operating noise at the end of the refresh process can be reduced. The linear control valve includes a pressure-increasing linear control valve that increases the hydraulic pressure of the hydraulic fluid that is transmitted to the wheel cylinder, and a pressure-reduction linear control valve that decreases the hydraulic pressure of the hydraulic fluid that is transmitted to the wheel cylinder. In this case, with the pressure-reducing linear control valve closed, the current value is gradually increased from a predetermined current value higher than the current value required to open or close the pressure-increasing linear control valve. The current of the pressure linear control valve may be controlled.

  Another feature of the present invention is that the refresh means estimates a refresh flow rate representing a flow rate that has flowed to the pressure reducing valve during the refresh process, and when the estimated refresh flow rate reaches a set flow rate, The flow control means (S431 to S437) for ending the refresh process is provided.

  The foreign matter removal performance of the pressure reducing valve depends on the flow rate of the working fluid that has flowed to the pressure reducing valve. Therefore, in the present invention, the refresh means includes a flow rate control means. The flow rate control means estimates a refresh flow rate that represents a flow rate (total flow rate) that has flowed through the pressure reducing valve during the foreign substance removal process. For example, the refresh flow rate is estimated based on a decrease in the hydraulic pressure of the hydraulic fluid pressurized by the power hydraulic pressure source. Then, when the estimated refresh flow rate reaches the specified flow rate, the refresh process of the pressure reducing valve is terminated. Therefore, the refresh process can be performed appropriately.

  Another feature of the present invention is that the refresh means includes valve closing timing setting means (S43, S44) for closing the pressure-reducing valve after closing the linear control valve when the refresh process is finished. There is.

  The refresh means opens the linear control valve and the pressure reducing valve so that the hydraulic fluid pressurized by the power hydraulic pressure source flows through the pressure reducing valve to perform a refresh process. When the refresh process is finished, Close the pressure reducing valve. When the linear control valve and the pressure reducing valve are closed, if the linear control valve is closed after the pressure reducing valve is closed first, there is no escape space for the hydraulic fluid and an operating noise is generated. Therefore, in the present invention, the valve closing timing setting means closes the pressure reducing valve after closing the linear control valve when finishing the refresh process. Thereby, the operation sound at the end of the refresh process can be reduced.

  Another feature of the present invention resides in that the refresh means divides and executes the refresh process so that a series of changes in the flow rate of the hydraulic fluid passing through the pressure reducing valve occurs multiple times.

  The foreign matter removal performance of the pressure reducing valve depends not only on the flow rate and flow rate of the hydraulic fluid flowing through the pressure reducing valve, but also on the flow rate fluctuation. Therefore, in the present invention, the refresh means divides and executes the refresh process so that a series of changes in the flow rate of the hydraulic fluid passing through the pressure reducing valve occurs multiple times. For example, the linear control valve is energized in a plurality of times. As a result, the refresh process can be performed satisfactorily using a limited time.

  In the above description, in order to help the understanding of the invention, the reference numerals used in the embodiments are attached to the configuration of the invention corresponding to the embodiment in parentheses, but each constituent element of the invention is the reference numeral. It is not limited to the embodiment defined by.

It is a schematic system block diagram of the brake control apparatus in this embodiment. It is a hydraulic circuit diagram showing a control hydraulic circuit in the linear control mode. It is a hydraulic circuit diagram showing a pedal effort hydraulic circuit in backup mode. It is a flowchart showing a valve abnormality inspection routine. It is a flowchart showing a refresh control routine. It is a flowchart showing the reexamination routine of a leak abnormality. It is a graph showing transition of the hydraulic pressure of a main channel. It is a hydraulic circuit diagram explaining the flow path through which hydraulic fluid flows during the refresh process. It is a graph showing the target electric current waveform sent through a pressure increase linear control valve. It is a graph showing transition of the control pressure Pcon and the target current value i * when the valve abnormality inspection routine is executed. It is a graph showing the relationship between the accumulator pressure and the supply flow rate of hydraulic fluid. It is a flowchart showing a flow control routine. 10 is a graph showing a target current waveform according to Modification 2.

  Hereinafter, a brake control device according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic system configuration diagram of a brake control device according to the present embodiment.

  The brake control device of the present embodiment includes a brake pedal 10, a master cylinder unit 20, a power hydraulic pressure generating device 30, a hydraulic pressure control valve device 50, and disc brake units 40FR, 40FL, 40RR provided on each wheel, respectively. , 40RL and a brake ECU 100 for controlling the brake. The disc brake units 40FR, 40FL, 40RR, 40RL include brake discs 41FR, 41FL, 41RR, 41RL and wheel cylinders 42FR, 42FL, 42RR, 42RL built in the brake caliper. In addition, about the structure provided for every wheel, although FR is attached to the end of the code | symbol, FR is attached to the left front wheel, RR is attached to the right rear wheel, RL is attached to the left rear wheel, When the wheel position is not specified, the last symbol is omitted.

  The wheel cylinders 42FR, 42FL, 42RR, and 42RL are connected to the hydraulic pressure control valve device 50, and the hydraulic pressure of the hydraulic fluid (brake fluid) supplied from the hydraulic pressure control valve device 50 is transmitted. The brake pads are pressed against the brake discs 41FR, 41FL, 41RR, 41RL that rotate with the brake discs, and braking force is applied to the wheels.

  The master cylinder unit 20 includes a hydraulic booster 21, a master cylinder 22, a regulator 23, and a reservoir 24. The hydraulic booster 21 is connected to the brake pedal 10, amplifies the pedal effort applied to the brake pedal 10, and transmits it to the master cylinder 22. The hydraulic pressure booster 21 amplifies the pedal depression force and transmits it to the master cylinder 22 when hydraulic fluid is supplied from the power hydraulic pressure generator 30 via the regulator 23. The master cylinder 22 generates a master cylinder pressure having a predetermined boost ratio with respect to the pedal effort.

  A reservoir 24 that stores hydraulic fluid is provided above the master cylinder 22 and the regulator 23. The master cylinder 22 communicates with the reservoir 24 when the depression of the brake pedal 10 is released. The regulator 23 communicates with both the reservoir 24 and the accumulator 32 of the power hydraulic pressure generator 30, and generates a hydraulic pressure substantially equal to the master cylinder pressure using the reservoir 24 as a low pressure source and the accumulator 32 as a high pressure source. Hereinafter, the hydraulic pressure of the regulator 23 is referred to as regulator pressure. Note that the master cylinder pressure and the regulator pressure need not be exactly the same. For example, the regulator pressure may be set to be slightly higher than the master cylinder pressure.

  The power hydraulic pressure generator 30 is a power hydraulic pressure source, and includes a pump 31 and an accumulator 32. The pump 31 has a suction port connected to the reservoir 24, a discharge port connected to the accumulator 32, and pressurizes the hydraulic fluid by driving the motor 33. The accumulator 32 converts the pressure energy of the hydraulic fluid pressurized by the pump 31 into the pressure energy of an enclosed gas such as nitrogen and stores it. The accumulator 32 is connected to a relief valve 25 provided in the master cylinder unit 20. The relief valve 25 opens to return the working fluid to the reservoir 24 when the pressure of the working fluid increases abnormally.

  As described above, the brake control device includes the master cylinder 22 that uses the driver's brake depression force (the force to depress the brake pedal 10), the regulator 23, and the driver as a hydraulic pressure source that applies hydraulic pressure to the wheel cylinder 42. And a power hydraulic pressure generator 30 that applies a hydraulic pressure regardless of the brake pedal force. The master cylinder 22, the regulator 23, and the power hydraulic pressure generator 30 are connected to the hydraulic control valve device 50 via the master pipe 11, the regulator pipe 12, and the accumulator pipe 13, respectively. The reservoir 24 is connected to the hydraulic control valve device 50 through the reservoir pipe 14.

  The hydraulic control valve device 50 is a main flow that connects the four individual flow paths 51FR, 51FL, 51RR, 51RL connected to the wheel cylinders 42FR, 42FL, 42RR, 42RL, and the individual flow paths 51FR, 51FL, 51RR, 51RL. A passage 52, a master passage 53 connecting the main passage 52 and the master pipe 11, a regulator passage 54 connecting the main passage 52 and the regulator pipe 12, and an accumulator connecting the main passage 52 and the accumulator pipe 13. And a flow path 55. Master channel 53, regulator channel 54, and accumulator channel 55 are connected in parallel to main channel 52.

  Each individual flow path 51FR, 51FL, 51RR, 51RL is provided with an ABS holding valve 61FR, 61FL, 61RR, 61RL in the middle thereof. The ABS holding valve 61 is a normally-open electromagnetic on-off valve that maintains a valve open state by a biasing force of a spring when the solenoid is not energized and is closed only when the solenoid is energized. In the open state, the ABS holding valve 61 can flow the hydraulic fluid in both directions and has no directionality.

  Further, return check valves 62FR, 62FL, 62RR, 62RL are provided in parallel to the ABS holding valves 61FR, 61FL, 61RR, 61RL in the individual flow paths 51FR, 51FL, 51RR, 51RL. The return check valve 62 is a valve that blocks the flow of hydraulic fluid from the main flow path 52 toward the wheel cylinder 42 and allows the flow of hydraulic fluid from the wheel cylinder 42 toward the main flow path 52. That is, when the hydraulic pressure of the wheel cylinder 42 (referred to as wheel cylinder pressure) is higher than the hydraulic pressure of the main flow path 52, the valve body is mechanically opened and the hydraulic fluid in the wheel cylinder 42 is caused to flow toward the main flow path 52. The valve element is configured to close when the wheel cylinder pressure becomes equal to the hydraulic pressure in the main flow path 52. Therefore, when the ABS holding valve 61 is closed and the wheel cylinder pressure is held, if the control hydraulic pressure in the main flow path 52 decreases and falls below the wheel cylinder pressure, the ABS holding valve 61 is closed. The wheel cylinder pressure can be reduced to the control fluid pressure of the main flow path 52 while maintaining the state.

  In addition, the individual flow paths 56FR, 56FL, 56RR, 56RL for decompression are connected to the individual flow paths 51FR, 51FL, 51RR, 51RL, respectively. Each decompression individual channel 56 is connected to a reservoir channel 57. The reservoir channel 57 is connected to the reservoir 24 via the reservoir pipe 14. ABS pressure reducing valves 63FR, 63FL, 63RR, 63RL are provided in the middle of the individual pressure reducing flow paths 56FR, 56FL, 56RR, 56RL, respectively. Each ABS pressure reducing valve 63 is a normally closed electromagnetic on-off valve that maintains a closed state by a biasing force of a spring when the solenoid is not energized and opens only when the solenoid is energized. Each ABS pressure reducing valve 63 reduces the wheel cylinder pressure by flowing the hydraulic fluid from the wheel cylinder 42 to the reservoir flow path 57 via the pressure reducing individual flow path 56 in the open state.

  The ABS holding valve 61 and the ABS pressure-reducing valve 63 are controlled to open and close when an anti-lock brake control is activated to reduce the wheel cylinder pressure and prevent the wheels from being locked when the wheels are locked and slip.

  The main flow path 52 is provided with a communication valve 64 in the middle thereof. The communication valve 64 is a normally-closed electromagnetic on-off valve that maintains a closed state by a biasing force of a spring when the solenoid is not energized and opens only when the solenoid is energized. The main flow path 52 is divided into a first main flow path 521 connected on one side to the master flow path 53 and a second main flow path 522 connected on the other side to the regulator flow path 54 and the accumulator flow path 55 with the communication valve 64 as a boundary. Is done. When the communication valve 64 is in the closed state, the flow of the hydraulic fluid between the first main flow path 521 and the second main flow path 522 is blocked, and when the communication valve 64 is in the open state, the first main flow path 521 is closed. And the second main flow path 522 are allowed to flow in both directions.

  The master flow path 53 is provided with a master cut valve 65 in the middle thereof. The master cut valve 65 is a normally-open electromagnetic on-off valve that maintains a valve open state by the biasing force of a spring when the solenoid is not energized and is closed only when the solenoid is energized. When the master cut valve 65 is in the closed state, the flow of hydraulic fluid between the master cylinder 22 and the first main flow path 521 is interrupted, and when the master cut valve 65 is in the open state, the master cylinder 22 and the first main flow path 521 are closed. The flow of the hydraulic fluid between the 1 main flow path 521 is allowed in both directions.

  In the master channel 53, a simulator channel 71 is branched and provided on the master cylinder 22 side from the position where the master cut valve 65 is provided. A stroke simulator 70 is connected to the simulator flow path 71 via a simulator cut valve 72. The simulator cut valve 72 is a normally closed electromagnetic on-off valve that maintains a closed state by a biasing force of a spring when the solenoid is not energized and is opened only when the solenoid is energized. When the simulator cut valve 72 is in the closed state, the flow of hydraulic fluid between the master flow path 53 and the stroke simulator 70 is interrupted, and when the simulator cut valve 72 is in the open state, the stroke of the master flow path 53 and The flow of the hydraulic fluid between the simulator 70 is allowed in both directions.

  The stroke simulator 70 includes a plurality of pistons and springs. When the simulator cut valve 72 is in an open state, the stroke simulator 70 is operated by introducing an amount of hydraulic fluid corresponding to the amount of brake operation. And a reaction force according to the pedal operation amount is generated to improve the driver's brake operation feeling.

  The regulator flow path 54 is provided with a regulator cut valve 66 in the middle thereof. The regulator cut valve 66 is a normally open electromagnetic on-off valve that maintains the valve open state by the biasing force of the spring when the solenoid is not energized and is closed only when the solenoid is energized. When the regulator cut valve 66 is in the closed state, the flow of hydraulic fluid between the regulator 23 and the second main flow path 522 is interrupted, and when the regulator cut valve 66 is in the open state, the regulator 23 and the second main flow The flow of hydraulic fluid to and from the path 522 is allowed in both directions.

  The accumulator channel 55 is provided with a pressure increasing linear control valve 67 in the middle thereof. The second main flow path 522 to which the accumulator flow path 55 is connected is connected to the reservoir flow path 57 via the pressure-reducing linear control valve 68. The pressure-increasing linear control valve 67 and the pressure-decreasing linear control valve 68 are normally maintained in a closed state by the biasing force of the spring when the solenoid is not energized, and the opening degree is increased as the energization amount (current value) to the solenoid increases. It is a closed electromagnetic linear control valve. The pressure-increasing linear control valve 67 and the pressure-decreasing linear control valve 68 are controlled by the force by which the spring urges the valve body in the valve closing direction and the differential pressure between the primary side (inlet side) and the secondary side (outlet side). When the valve closing force, which is the difference from the force urged in the valve opening direction, is maintained, and the force that opens the valve element generated by energizing the solenoid exceeds this valve closing force. The valve is opened at an opening corresponding to the balance of the force acting on the valve body. Therefore, the opening degree can be adjusted by controlling the energization amount (current value) to the solenoid. The pressure increasing linear control valve 67 and the pressure reducing linear control valve 68 correspond to the linear control valve in the present invention.

  The power hydraulic pressure generating device 30 and the hydraulic pressure control valve device 50 are driven and controlled by the brake ECU 100. The brake ECU 100 includes a microcomputer as a main part, and also includes a pump drive circuit, an electromagnetic valve drive circuit, an input interface for inputting various sensor signals, a communication interface, and the like. The electromagnetic open / close valve and the electromagnetic linear control valve provided in the hydraulic pressure control valve device 50 are all connected to the brake ECU 100, and the open / close state and opening degree (in the case of an electromagnetic linear control valve) by a solenoid drive signal output from the brake ECU 100. Is controlled. Further, the motor 33 provided in the power hydraulic pressure generator 30 is also connected to the brake ECU 100 and driven and controlled by a motor drive signal output from the brake ECU 100.

  The hydraulic pressure control valve device 50 is provided with an accumulator pressure sensor 101, a regulator pressure sensor 102, and a control pressure sensor 103. The accumulator pressure sensor 101 detects an accumulator pressure Pacc that is the pressure of the working fluid in the accumulator flow channel 55 on the power hydraulic pressure generator 30 side (upstream side) from the pressure-increasing linear control valve 67. The accumulator pressure sensor 101 outputs a signal representing the detected accumulator pressure Pacc to the brake ECU 100. The regulator pressure sensor 102 detects the regulator pressure Preg that is the pressure of the hydraulic fluid in the regulator flow path 54 on the regulator 23 side (upstream side) than the regulator cut valve 66. The regulator pressure sensor 102 outputs a signal representing the detected regulator pressure Preg to the brake ECU 100. The control pressure sensor 103 outputs a signal representing the control pressure Pcon that is the pressure of the hydraulic fluid in the first main flow path 521 to the brake ECU 100.

  The brake ECU 100 is connected to a stroke sensor 104 provided on the brake pedal 10. The stroke sensor 104 detects a pedal stroke that is a depression amount (operation amount) of the brake pedal 10 and outputs a signal representing the detected pedal stroke Sp to the brake ECU 100.

  Next, brake control executed by the brake ECU 100 will be described. In the present embodiment, at least two braking modes, a linear control mode and a backup mode, are set, and the brake ECU 100 switches between the braking modes. The linear braking mode corresponds to the control hydraulic pressure mode in the present invention.

  The vehicle provided with the brake control device of the present embodiment is a hybrid vehicle including a motor driven by a battery power source and an internal combustion engine driven by gasoline fuel. In a hybrid vehicle, regenerative braking is performed in which a motor is generated by the rotational force of a wheel and braking power is obtained by regenerating the generated power in a battery. When performing such regenerative braking, regenerative braking and hydraulic braking are used in combination by generating a braking force, which is the total braking force required to brake the vehicle, excluding the regenerative braking force by the brake control device. Brake regeneration cooperative control can be performed.

  The brake regeneration cooperative control is executed in the linear control mode. In the linear control mode, the depressing force when the driver depresses the brake pedal 10 is used only for detecting the brake operation amount and is not transmitted to the wheel cylinder 42, but instead output from the power hydraulic pressure generator 30. The hydraulic pressure is regulated by the linear control valves 67 and 68 and transmitted to the wheel cylinder 42. On the other hand, the backup mode is a braking mode that is executed when some abnormality occurs in the brake control device, and the hydraulic pressure pressurized by the brake pedal depression force is transmitted to the wheel cylinder 42. The brake ECU 100 switches between the linear control mode and the backup mode by switching the flow path through which the hydraulic fluid flows with the hydraulic pressure control valve device 50. The linear control mode is a braking mode that is normally performed (when no abnormality is detected), and it is not always necessary to execute the brake regeneration cooperative control.

  In the linear control mode, the master cut valve 65 and the regulator cut valve 66 are kept closed by energizing the solenoid, and the communication valve 64 is kept open by energizing the solenoid. Further, the simulator cut valve 72 is maintained in an open state by energizing the solenoid. Further, the pressure-increasing linear control valve 67 and the pressure-decreasing linear control valve 68 are controlled to the opening degree corresponding to the energization amount when the solenoid is in the energization control state. The ABS holding valve 61 and the ABS pressure reducing valve 63 are opened and closed as necessary, such as anti-lock brake control. Normally, the ABS holding valve 61 is maintained in an open state, and the ABS pressure reducing valve 63 is in a closed state. Maintained.

  In the linear control mode, the master cut valve 65 and the regulator cut valve 66 are closed, so that the hydraulic pressure output from the master cylinder unit 20 is not transmitted to the wheel cylinder 42. Further, the communication valve 64 is maintained in the open state, and the pressure-increasing linear control valve 67 and the pressure-decreasing linear control valve 68 are put in the energization control state. Therefore, in the linear control mode, as shown in FIG. 2, a hydraulic circuit L1 (control hydraulic circuit in the present invention) that connects the power hydraulic pressure generator 30 and the four-wheel wheel cylinder 42 is formed. Therefore, the hydraulic pressure (accumulator pressure) output from the power hydraulic pressure generator 30 is adjusted by the pressure-increasing linear control valve 67 and the pressure-decreasing linear control valve 68 and transmitted to the four-wheel wheel cylinder 42. In this case, since each wheel cylinder 42 is communicated by the main flow path 52, the wheel cylinder pressure is the same for all four wheels. This wheel cylinder pressure can be detected by the control pressure sensor 103.

  The brake ECU 100 starts the brake regeneration cooperative control in response to the braking request. The braking request is generated when a braking force is to be applied to the vehicle, for example, when the driver depresses the brake pedal 10. When receiving the braking request, the brake ECU 100 calculates the required braking force based on the pedal stroke Sp detected by the stroke sensor 104 and the regulator pressure Preg detected by the regulator pressure sensor 102. The required braking force is set to a larger value as the pedal stroke Sp is larger and the regulator pressure Preg is larger. In this case, for example, the pedal stroke Sp and the regulator pressure Preg are multiplied by the weighting coefficients Ks and Kr, respectively, and in the range where the pedal stroke Sp is small, the weighting coefficient Ks of the pedal stroke Sp is set large. In a range where Sp is large, the required braking force may be calculated by setting the weighting coefficient Kr of the regulator pressure Preg large.

  The brake ECU 100 transmits information representing the calculated required braking force to the hybrid ECU. The hybrid ECU calculates a braking force generated by power regeneration from the required braking force, and transmits information representing the regenerative braking force, which is the calculation result, to the brake ECU 100. Accordingly, the brake ECU 100 calculates a required hydraulic braking force that is a braking force that should be generated by the brake control device by subtracting the regenerative braking force from the required braking force. The regenerative braking force generated by the power regeneration performed by the hybrid ECU not only changes depending on the rotation speed of the motor, but also changes due to the regenerative current control depending on the state of charge (SOC) of the battery. Accordingly, an appropriate required hydraulic braking force can be calculated by subtracting the regenerative braking force from the required braking force.

  The brake ECU 100 calculates the target hydraulic pressure of each wheel cylinder 42 based on the calculated required hydraulic braking force, and reduces the pressure increase linear control valve 67 and the pressure reduction by feedback control so that the wheel cylinder pressure becomes equal to the target hydraulic pressure. The drive current of the linear control valve 68 is controlled. That is, the current flowing through each solenoid of the pressure-increasing linear control valve 67 and the pressure-decreasing linear control valve 68 is controlled so that the control pressure Pcon (= wheel cylinder pressure) detected by the control pressure sensor 103 follows the target hydraulic pressure. .

  As a result, the hydraulic fluid is supplied from the power hydraulic pressure generator 30 to each wheel cylinder 42 via the pressure-increasing linear control valve 67, and braking force is generated on the wheels. Further, as necessary, the hydraulic fluid is discharged from the wheel cylinder 42 via the pressure-reducing linear control valve 68, and the braking force generated on the wheel is adjusted.

  Further, the brake ECU 100 reads the accumulator pressure Pacc detected by the accumulator pressure sensor 101 at a predetermined cycle. When the accumulator pressure Pacc falls below the preset minimum set pressure, the brake ECU 100 drives the motor 33 to drive the hydraulic fluid. Is controlled so that the accumulator pressure Pacc is always maintained within the set pressure range. The motor 33 is controlled not only in the linear control mode but also in the backup mode.

  In the linear control mode, the brake ECU 100 maintains the simulator cut valve 72 in the open state. For this reason, the hydraulic fluid sent from the master cylinder 22 is supplied to the stroke simulator 70 as the driver depresses the brake pedal 10. As a result, a reaction force corresponding to the pedaling force of the driver can be applied to the brake pedal 10, and a good pedal operation feeling can be given to the driver.

  Note that the brake ECU 100 switches from the linear control mode to the non-braking mode when no braking request is received. In the non-braking mode, the master cut valve 65, the regulator cut valve 66, and the communication valve 64 are each maintained in an open state, and the simulator cut valve 72, the pressure increasing linear control valve 67, and the pressure reducing linear control valve 68 are closed. Maintained in a state.

  Next, the backup mode will be described. In the backup mode, energization to the electromagnetic on-off valve and the electromagnetic linear control valve in the hydraulic control valve device 50 is stopped. Therefore, the master cut valve 65 and the regulator cut valve 66 which are normally open solenoid valves are maintained in the open state. Further, the communication valve 64, which is a normally closed solenoid valve, the simulator cut valve 72, and the pressure increasing linear control valve 67 and the pressure reducing linear control valve 68, which are normally closed solenoid linear valves, are maintained in a closed state. Further, the ABS holding valve 61 is maintained in an open state, and the ABS pressure reducing valve 63 is maintained in a closed state.

  Therefore, in the backup mode, the communication between the power hydraulic pressure generating device 30 and each wheel cylinder 42 is cut off, and instead, as shown in FIG. 3, the master cylinder 22 and the front wheel wheel cylinders 42FR and 42FL communicate with each other. The front wheel pedal force hydraulic circuit LF and the rear wheel pedal force hydraulic circuit LR that communicates the regulator 23 with the wheel cylinders 42RR and 42RL of the rear wheels are formed. The front wheel pressing force hydraulic circuit LF and the rear wheel pressing force hydraulic circuit LR are provided independently of each other because the communication valve 64 is maintained in the closed state. Accordingly, the master cylinder pressure is transmitted to the front wheel wheel cylinders 42FR and 42FL, and the regulator pressure is transmitted to the rear wheel wheel cylinders 42RR and 42RL.

  The backup mode is a braking mode that is executed when any abnormality is detected in the brake control device. Therefore, during normal braking (when no abnormality is detected), the linear control mode is selected.

  As one of the abnormalities of the brake control device, there is an abnormality in which foreign matter bites into the ABS pressure reducing valve 63 and hydraulic fluid leaks. When an abnormality is detected, the brake control device switches the braking mode from the linear control mode to the backup mode. However, regarding the leakage abnormality of the ABS pressure reducing valve 63, the brake control device does not want to switch to the backup mode as much as possible. For example, when a leakage abnormality is detected in the ABS pressure reducing valve 63FR for the right front wheel, when switching to the backup mode, the wheel cylinders 42FR, 42FL for the front wheels are disconnected from the power hydraulic pressure generator 30 and communicate with the master cylinder 22. become. Accordingly, during brake braking, the working fluid is supplied from the master cylinder 22 to the wheel cylinders 42FR and 42FL. However, the working fluid leaks from the ABS pressure reducing valve 63FR and flows into the reservoir flow path 57. It may not be possible to generate an appropriate wheel cylinder pressure. In particular, the front wheel ABS pressure reducing valve 63FR (63FL) has a larger valve opening area than the rear wheel ABS pressure reducing valve 63RR (63RL). Therefore, when the front wheel ABS pressure reducing valve 63FR (63FL) has a leakage abnormality. Tends to run out of wheel cylinder pressure.

  In this case, if the mode is not switched to the backup mode, the four wheel cylinders 42FR, 42FL, 42RR, 42RL are connected to the power hydraulic pressure generating device 30, so that the hydraulic fluid is supplied from the ABS pressure reducing valve 63FR to the reservoir channel 57. Even if it leaks, the hydraulic fluid having a flow rate sufficient to compensate for the leak amount can be supplied from the power hydraulic pressure generator 30. That is, the power hydraulic pressure generator 30 is configured to transmit hydraulic pressure to the four wheel cylinders 42FR, 42FL, 42RR, 42RL using the pump 31 and the accumulator 32. The flow rate at which the hydraulic fluid can be supplied is large, and the flow rate leaked from one ABS pressure reducing valve 63FR can be supplemented by the supply amount of the hydraulic fluid.

  However, if the linear control mode is continued as it is, the load of the motor 33 of the pump 31 for pressurizing the hydraulic fluid becomes excessive, and this time, it becomes easy to cause a pump abnormality. If the operation of the power hydraulic pressure generator 30 is stopped due to a motor abnormality, the hydraulic fluid cannot be pressurized by the regulator 23, and liquid is applied to the rear wheel wheel cylinders 42RR and 42RL even in the backup mode. The pressure cannot be applied.

  On the other hand, a leakage abnormality due to foreign matter clogging of the ABS pressure reducing valve 63 can be restored to normal by appropriately passing the hydraulic fluid. In particular, since the opening area of the ABS pressure reducing valve 63 is larger than that of the ABS holding valve 61, any foreign matter that has passed through the ABS holding valve 61 can be removed.

  Therefore, in the present embodiment, when the leakage abnormality of the ABS pressure reducing valve 63 is inspected and when the leakage abnormality of the ABS pressure reducing valve 63 is detected, the foreign matter removal is first tried instead of immediately entering the backup mode. Switch from the linear control mode to the backup mode only when the leakage abnormality cannot be resolved.

  FIG. 4 is a flowchart showing a valve abnormality inspection routine executed by the brake ECU 100. This valve abnormality inspection routine includes inspection processing for leakage abnormality of the front wheel ABS pressure reducing valves 63FR and 63FL and leakage abnormality of the communication valve 64, and refresh control when a leakage abnormality of the front wheel ABS pressure reducing valves 63FR and 63FL is detected. And a re-inspection process after the refresh control process. In the following description, it is assumed that no abnormality is detected in the brake control device at the time of starting the valve abnormality inspection routine.

  When the valve abnormality inspection routine is activated, the brake ECU 100 determines in step S11 whether or not the ignition switch has been switched from the on state to the off state. The brake ECU 100 waits until the ignition switch is turned off. When the brake ECU 100 detects that the ignition switch is turned off, the brake ECU 100 waits until a predetermined time Tig elapses after the ignition switch is turned off. Note that the brake ECU 100 does not immediately stop the system when the ignition switch is turned off, but stops the system after the end of the valve abnormality inspection routine. Subsequently, the brake ECU 100 closes the master cut valve 65 and the regulator cut valve 66 in step S13. In addition, what is necessary is just to maintain the state, when each valve 65 and 66 is a valve closing state. At this time, the communication valve 64 is open. Further, all the ABS holding valves 61 are in an open state (non-energized state), and all the ABS pressure reducing valves 63 are in a closed state (non-energized state).

  Subsequently, in step S14, the brake ECU 100 opens the pressure-increasing linear control valve 67 until the control pressure Pcon detected by the control pressure sensor 103 reaches a preset set pressure P1 (referred to as initial pressure P1). . In this case, since the communication valve 64 is in an open state, the same hydraulic pressure acts on the four-wheel individual flow paths 51. When the control pressure Pcon reaches the initial pressure P1, the brake ECU 100 closes the pressure-increasing linear control valve 67 and stops pressurization.

  Subsequently, the brake ECU 100 closes the communication valve 64 in step S15, and opens the pressure-increasing linear control valve 67 again in step S16. In this case, the brake ECU 100 supplies a set current to the pressure-increasing linear control valve 67 for a preset repressurization time. As a result, the hydraulic fluid in the second main flow path 522 that becomes the flow path on the rear wheel side is further pressurized. Further, in the first main flow path 521, the communication valve 64 is closed, so that the hydraulic fluid is not pressurized if the communication valve 64 is normal. When the repressurization time has elapsed, the brake ECU 100 stops energization of the pressure-increasing linear control valve 67.

  When the repressurization by the pressure-increasing linear control valve 67 is completed, the brake ECU 100 stands by until a preset time T1 has elapsed in step S17. Subsequently, in step S18, the brake ECU 100 stores the control pressure Pcon detected by the control pressure sensor 103 as the detected pressure P2.

  Subsequently, in step S19, the brake ECU 100 determines whether or not the difference | P2-P1 | between the detected pressure P2 and the initial pressure P1 is larger than a preset leakage determination threshold value ΔP.

  When the hydraulic fluid is repressurized in step S16 described above, the communication valve 64 and the ABS pressure reducing valve 63 are maintained in the closed state. Therefore, if there is no leakage abnormality in the communication valve 64 and the ABS pressure reducing valve 63, FIG. As shown in FIG. 7, the hydraulic pressure in the first main flow path 521 should be kept constant regardless of repressurization of the hydraulic fluid by opening the pressure-increasing linear control valve 67. On the other hand, when a leakage abnormality has occurred in the communication valve 64, the hydraulic fluid flows from the communication valve 64 to the first main flow path 521, so the hydraulic pressure in the first main flow path 521 increases. In addition, when any one of the ABS pressure reducing valves 63FR and 63FL on the front wheels has a leakage abnormality, the hydraulic fluid flows out from the ABS pressure reducing valve 63FR (63FL) to the reservoir flow path 57, so that the first main flow path 521 The hydraulic pressure drops. The brake ECU 100 determines the leakage abnormality of the communication valve 54 and the ABS pressure reducing valves 63FR and 63FL by detecting such a change in the hydraulic pressure in the first main flow path 521 by a change in the detection value of the control pressure sensor 103.

  If the brake ECU 100 determines in step S19 that the pressure fluctuation amount | P2-P1 | of the first main flow path 521 is equal to or less than the leakage determination threshold value ΔP, in step S20, the brake valve 64 and the ABS pressure reducing valve 63FR, It is determined that 63FL is normal. Subsequently, in step S21, the linear control mode is set as the braking mode, and the valve abnormality inspection routine is ended. The brake ECU 100 stops the system when the valve abnormality inspection routine ends. Thus, the brake control in the linear control mode is executed from the next system activation (for example, from the ON operation of the ignition switch).

  If the brake ECU 100 determines in step S19 that the pressure fluctuation amount | P2-P1 | of the first main flow path 521 is larger than the leakage determination threshold value ΔP, the pressure fluctuation of the first main flow path 521 increases in step S22. Judge whether it is a decrease or a decrease. In this case, it may be determined whether (P2−P1) is a positive value or a negative value. If the brake ECU 100 determines that (P2-P1) is a positive value in step S22, the brake ECU 100 determines in step S23 that a leakage abnormality has occurred in the communication valve 54. Subsequently, in step S24, the backup mode is set as the braking mode, and the valve abnormality inspection routine is ended. Thereby, the brake control in the backup mode is executed from the next system activation.

  If the brake ECU 100 determines in step S22 that (P2-P1) is a negative value, in step S25, at least one of the ABS pressure reducing valves 63FR and 63FL on the front wheels has a leakage abnormality. Is determined. Subsequently, in step S30, a refresh control process is executed, and in a subsequent step S90, a re-inspection process of the front wheel ABS pressure reducing valves 63FR, 63FL is executed, and the valve abnormality inspection routine is ended.

  The refresh control process will be described with reference to FIG. FIG. 5 is a flowchart showing a refresh control routine representing the process of step S30. In this refresh control routine, a liquid passing process for flowing the working fluid one by one in order is performed for all the ABS pressure reducing valves 63FR, 63FL, 63RR, 63RL, and all the ABS pressure reducing valves 63FR, 63FL, 63RR, After the 63RL liquid passing process is completed, the pressure reducing linear control valve 68 is further subjected to a liquid passing process. Hereinafter, the liquid passing process in which the working fluid is allowed to flow through the valve opening flow path in order to remove foreign substances is referred to as a refresh process.

  When the refresh control routine is started, the brake ECU 100 determines in step S31 whether or not the accumulator pressure Pacc detected by the accumulator pressure sensor 101 exceeds a predetermined specified pressure Pacc0, and the accumulator pressure Pacc is determined to be the specified pressure Pacc0. In the following cases, the process waits until the specified pressure Pacc0 is exceeded. The motor 33 of the pump 31 is automatically energized when the accumulator pressure Pacc falls below a preset minimum set pressure, and is controlled so that the accumulator pressure Pacc is always maintained within the set pressure range. Therefore, the specified pressure Pacc0 is set so as to fall within a range where the motor 33 is driven to be energized.

  The process of step S31 is intended to ensure an appropriate accumulator pressure when starting the refresh process. When the accumulator pressure Pacc exceeds the specified pressure Pacc0 or waits until the brake ECU 100 exceeds the specified pressure Pacc0, the brake ECU 100 opens the communication valve 64 in the subsequent step S32.

  Subsequently, the brake ECU 100 executes a refresh process for the ABS pressure reducing valve 63FR for the right front wheel in steps S41 to S44. First, in step S41, the brake ECU 100 closes the ABS holding valves 61FL, 61RR, 61RL other than the ABS holding valve 61FR for the right front wheel. Subsequently, in step S42, the right front wheel ABS pressure reducing valve 63FR is opened. Subsequently, in step S43, the pressure increasing linear control valve 67 is gently opened by current control of the pressure increasing linear control valve 67, and then gently closed.

  When the pressure-increasing linear control valve 67 is opened, as shown in FIG. 8, the hydraulic fluid flows from the power hydraulic pressure generator 30 through the pressure-increasing linear control valve 67 to the main flow path 22, and the communication valve 64 and the ABS are held. It returns to the reservoir channel 57 through the valve 61FR and the ABS pressure reducing valve 63FR. When the ABS pressure reducing valve 63FR is clogged with foreign matter, the foreign matter can be removed by the flow of the working fluid. The foreign matter removal performance is proportional to the flow rate and flow rate of the hydraulic fluid passing through the ABS pressure reducing valve 66FR. On the other hand, when the hydraulic fluid is flowed in this way, an operating sound (oil hammering sound) having a magnitude proportional to a change in the flow rate of the hydraulic fluid is generated. Therefore, in the present embodiment, by controlling the current flowing through the pressure-increasing linear control valve 67, the flow rate change during the valve opening operation and the valve closing operation is reduced, and the operating noise is reduced.

FIG. 9 shows a current waveform for energizing the pressure-increasing linear control valve 67 when the refresh process is performed. The target current value i * in the valve opening operation of the pressure-increasing linear control valve 67 is set by the following equation.
i * = (iopen−Δi1) + K · t
Here, iopen is a valve opening current value indicating a current (minimum current required for valve opening) required for the pressure increasing linear control valve 67 to perform the valve opening operation, and Δi1 is a current value at the start of the valve opening operation. A current value set in advance so as to be smaller than the valve opening current value, K is a current gradient in which the degree of increasing the current value is set in advance, and t represents an elapsed time.

  The pressure-increasing linear control valve 67 has a larger opening degree as the current supplied to the solenoid is larger, and in order to obtain the same opening degree as the differential pressure between the primary side (inlet side) and the secondary side (outlet side) is larger. The required current is small. The brake ECU 100 stores a map representing the relationship between the differential pressure between the primary pressure and the secondary pressure of the pressure-increasing linear control valve 67 and the valve opening current value iopen. With reference to this map, the valve opening current value is stored. iopen is calculated. In this case, a valve opening current value iopen corresponding to the differential pressure between the accumulator pressure Pacc detected by the accumulator pressure sensor 101 and the control pressure Pcon detected by the control pressure sensor 103 may be calculated.

The target current value i * is set so that the current value ((iopen−Δi1) + K · t1) is maintained for the set time t2 when the set time t1 elapses from the start of energization, and when the set time t2 elapses, A value for closing the pressure-increasing linear control valve 67 is set. The target current value i * in the valve closing operation of the pressure-increasing linear control valve 67 is set by the following equation.
i * = (iopen + Δi2) + α ⁿ
Here, Δi2 is a current value for setting the current value at the start of the valve closing operation to a value larger by a predetermined amount than the valve opening current value, and α is an attenuation set to a value larger than 0 and smaller than 1. The coefficient n represents a variable whose value is incremented by 1 every predetermined time (for example, several milliseconds) with an initial value of 1. Further, the target current value i * is set to zero when the set time t3 has elapsed since the start of the valve closing operation. In this embodiment, iopen used for calculating the target current value i * in the valve closing operation is the current value required for the pressure-increasing linear control valve 67 to switch from the valve closing state to the valve opening state. However, iopen is a current value (current value when switching to the closed state by lowering the current value) required for the pressure-increasing linear control valve 67 to switch from the open state to the closed state. Also good.

  As described above, the target current value i * to be supplied to the pressure-increasing linear control valve 67 is set so as to increase linearly during the valve opening operation and decrease exponentially during the valve closing operation. Has been. During the opening operation of the pressure-increasing linear control valve 67, the supply of hydraulic fluid is started from the high-pressure source, so that the flow rate change tends to be large. Accordingly, the target current value i * is increased in a linear function to open the pressure-increasing linear control valve 67 smoothly. Further, the valve closing operation of the pressure-increasing linear control valve 67 is started from a state in which the hydraulic pressure is reduced by supplying the hydraulic fluid, so that the flow rate change does not increase as in the valve opening operation. Therefore, the target current value i * is decreased exponentially so as to close the valve faster than the valve opening operation.

  In step S43, the brake ECU 100 causes the current having the target current value i * to flow through the pressure-increasing linear control valve 67. As a result, when the hydraulic fluid having a flow rate adjusted by the pressure-increasing linear control valve 67 passes through the ABS pressure reducing valve 63FR of the right front wheel and the foreign matter is clogged, the foreign matter is removed by the flow of the hydraulic fluid. In this case, since the opening degree of the pressure-increasing linear control valve 67 is controlled by the target current value i * as described above, generation of an oil hammer sound during the valve-opening operation and the valve-closing operation of the pressure-increasing linear control valve 67 Is reduced.

  Subsequently, in step S44, the brake ECU 100 closes the ABS pressure reducing valve 63FR for the right front wheel. In this case, the ABS pressure reducing valve 63FR for the right front wheel is closed after the pressure increasing linear control valve 67 is closed. Thus, the refresh process for the ABS pressure reducing valve 63FR for one wheel is completed. Subsequently, in step S50, the brake ECU 100 performs a refresh process for the ABS pressure reducing valve 63FL for the left front wheel, performs a refresh process for the ABS pressure reducing valve 63RR for the right rear wheel, and in step S70, performs a refresh process for the left rear wheel. The ABS pressure reducing valve 63RL is refreshed. The process of each step S50-S70 is the same as the process of step S41-S44, Comprising: What is necessary is just to make the ABS holding valve 61 and the ABS pressure-reduction valve 63 used as valve opening object of the said object wheel. Further, in the other three wheels, the current control of the pressure-increasing linear control valve 67 is the same as the processing in step S43.

  When the brake ECU 100 performs the refresh process for the ABS pressure reducing valve 63RL for the left rear wheel, the brake holding valve 61RL for the left rear wheel is closed in step S81. As a result, the ABS holding valves 61FR, 61FL, 61RR, 61RL of all four wheels are closed.

  Subsequently, the brake ECU 100 starts a refresh process for the pressure-reducing linear control valve 68. First, in step S82, the pressure-reducing linear control valve 68 is opened. Subsequently, in step S83, the pressure increasing linear control valve 67 is gently opened by current control of the pressure increasing linear control valve 67, and then gradually closed. This process is the same as the process of step S43. Thereby, when the hydraulic fluid passes through the pressure-reducing linear control valve 68 at a flow rate adjusted by the pressure-increasing linear control valve 67 and the foreign matter is clogged, the foreign matter is removed by the flow of the hydraulic fluid.

  Subsequently, the brake ECU 100 opens the ABS holding valves 61FR, 61FL, 61RR, 61RL of all the four wheels in step S84, and closes the pressure-reducing linear control valve 68 in the subsequent step S85. Thereby, when a series of refresh processing is completed, the brake ECU 100 performs a leakage abnormality reinspection of the ABS pressure reducing valves 63FR and 63FL in step S90.

  This re-inspection processing is executed in accordance with a leakage abnormality re-inspection routine shown in FIG. When the leakage abnormality reinspection routine is started, the brake ECU 100 executes a pressure change detection process in step S91. This pressure change detection process is the same as the process from step S14 to step S18 described above. Subsequently, in step S92, the brake ECU 100 determines whether or not the pressure fluctuation amount | P2-P1 | of the first main flow path 521 is larger than the leakage determination threshold value ΔP. If the pressure fluctuation amount | P2-P1 | is equal to or less than the leakage determination threshold value ΔP, it is determined in step S93 that the ABS pressure reducing valves 63FR and 63FL are normal. That is, it is determined that the foreign matter of the ABS pressure reducing valve 63FR (63FL) has been removed and the normal state has been restored by executing the refresh control routine described above. In step S94, the brake ECU 100 sets the linear control mode as the braking mode, and ends the reinspection routine.

  On the other hand, if the pressure fluctuation amount | P2-P1 | is larger than the leakage determination threshold value ΔP, it is determined in step S95 that the leakage abnormality of the front wheel ABS pressure reducing valve 63FR (63FL) has not been eliminated. In this case, the brake ECU 100 sets the backup mode as the braking mode in step S96 and ends the re-inspection routine.

  The brake ECU 100 opens the communication valve 64 and opens the pressure-reducing linear control valve 68 to reduce the pressure in the flow path when the valve abnormality inspection routine ends.

  FIG. 10 shows transitions of the control pressure Pcon (one-dot chain line) and the target current value i * (solid line) when the valve abnormality inspection routine is executed. In this example, a leakage abnormality of the front wheel ABS pressure reducing valve 63FR (63FL) is detected during the first inspection, and the leakage abnormality is eliminated by refresh control.

  According to the brake control device of the present embodiment described above, the leakage abnormality between the communication valve 64 and the front wheel ABS pressure reducing valves 63FR and 63FL is inspected after a predetermined time after the ignition switch is turned off. When a leakage abnormality of the communication valve 64 is detected, the braking mode is set to the backup mode, and is started in the backup mode from the next startup. When a leakage abnormality of the communication valve 64 occurs, a sufficient braking force can be ensured even in the brake control in the backup mode. On the other hand, if a leakage abnormality occurs in the ABS pressure reducing valves 63FR and 63FL for the front wheels, the braking force may be insufficient if the backup mode is set. Further, even if a leakage abnormality occurs in the ABS pressure reducing valves 63FR and 63FL on the front wheels, if the cause is due to foreign matter clogging, the foreign matter can be obtained by appropriately passing the hydraulic fluid through the ABS pressure reducing valves 63FR and 63FL. Can be removed. In particular, the ABS pressure reducing valve 63 has a larger valve opening passage area than the ABS holding valve 61 on the upstream side thereof, so that any foreign matter that has passed through the ABS holding valve 61 can pass through the ABS pressure reducing valve 63. .

  Therefore, in the present embodiment, when a leakage abnormality of the ABS pressure reducing valves 63FR and 63FL for the front wheels is detected, the refresh control routine (S30) is executed instead of immediately setting the backup mode. As a result, when the leakage abnormality of the ABS pressure reducing valves 63FR and 63FL is resolved, the linear control mode is set without setting the backup mode. Therefore, it can be started in the linear control mode from the next startup. Further, the backup mode is set only when the leakage abnormality of the ABS pressure reducing valves 63FR and 63FL is not solved. Thereby, the situation where the motor 33 of the pump 31 is overloaded can be prevented.

  Since the foreign matter removal performance depends on the flow rate and flow rate of the hydraulic fluid passing through the ABS pressure reducing valve 63, it is desirable to increase the flow rate and flow rate as much as possible. On the other hand, a flow noise is generated as the flow rate and flow rate of the hydraulic fluid are increased. This flow noise is generated particularly by the pressure-increasing linear control valve 67. This is because the pressure-increasing linear control valve 67 has the largest differential pressure in the flow path and becomes a part where the total flow rate is concentrated. Therefore, in the refresh control routine of the present embodiment, the hydraulic fluid is not allowed to pass through the four-wheel ABS pressure reducing valves 63FR, 63FL, 63RR, 63RL at the same time, but the hydraulic fluid is sequentially passed through one wheel at a time. To implement. As a result, the flow rate required for foreign matter removal can be passed through the ABS pressure reducing valve 63 while the flow rate of the hydraulic fluid flowing through the pressure increasing linear control valve 67 is kept low. As a result, it is possible to achieve both a reduction in the flow noise of the hydraulic fluid and an improvement in the foreign matter removal performance.

  Further, the foreign matter clogged in the ABS pressure reducing valve 63 can be sufficiently removed by executing the refresh control routine once. Therefore, if the abnormality is not resolved in the reexamination (S90) after the execution of the refresh control routine, the refresh control routine is not executed again. In other words, the period from the system start to the system stop of the brake control device (the period from the start to the end of the brake control) is one trip, and the refresh process is performed only once per trip regardless of the re-inspection result To do. The refresh process is performed only when a leakage abnormality of the ABS pressure reducing valve 63 is detected. Thereby, the frequency | count of generation | occurrence | production of the flowing sound of a hydraulic fluid can be reduced.

  In addition, when the refresh control routine is executed, the valve opening and closing operations of the pressure-increasing linear control valve 67 are gently performed by the energization current control of the pressure-increasing linear control valve 67. The change in the flow rate of the hydraulic fluid during the valve operation is suppressed. Thereby, an operation sound (oil hammering sound) can be reduced.

  Further, when the refresh control routine is executed, when the refresh process of each ABS pressure reducing valve 63 is finished, the pressure increasing linear control valve 67 is surely closed and then the ABS pressure reducing valve 63 is closed. (S43 → S44). Thereby, generation | occurrence | production of an operating sound (oil hammering sound) can be prevented. If the valve closing order is reversed and the ABS pressure reducing valve 63 is closed and then the pressure-increasing linear control valve 67 is closed, there is no escape space for the introduced hydraulic fluid, so that the operating sound (oil hammering sound) ) Will occur.

  Next, a modification of the above-described embodiment will be described.

<Modification 1>
In the present embodiment, the refresh processing period of each ABS pressure reducing valve 63 is controlled by the energization time of the pressure increasing linear control valve 67 (S43). That is, the valve closing operation is started after a predetermined time (t1 + t2) has elapsed from the start of the valve opening operation. On the other hand, in the first modification, the flow rate of the hydraulic fluid that has passed through the pressure-increasing linear control valve 67 (the total flow rate of the hydraulic fluid that has passed through the ABS pressure reducing valve 63) is estimated, and the estimated flow rate is preset. When the set flow rate is reached, the valve closing operation is started.

  In the first modification, the brake ECU 100 calculates the estimated flow rate Qx based on the fluctuation amount ΔPacc of the accumulator pressure Pacc detected by the accumulator pressure sensor 101 and the supply flow rate Qpon of the pump 31. The relationship between the accumulator pressure Pacc and the supply flow rate Q of the hydraulic fluid has characteristics as shown in FIG. Therefore, when the accumulator pressure Pacc has decreased by ΔPacc from the start of the valve-opening operation of the pressure-increasing linear control valve 67, the hydraulic fluid having the flow rate ΔQ corresponding to ΔPacc has passed through the pressure-increasing linear control valve 67. Become. This characteristic is a characteristic when the pump 31 is not operating. Therefore, when the pump 31 is operating, it is necessary to add the pump supply flow rate Qpon. The pump supply flow rate Qpon can be calculated by multiplying the supply flow rate (known) per unit time of the pump 31 by the operation time of the pump 31.

Therefore, the estimated flow rate Qx can be calculated by the following equation.
Qx = f (ΔPacc) + Qpon
f is a function representing the relationship between the accumulator pressure Pacc and the hydraulic fluid supply flow rate Q.

  The brake ECU executes a flow rate control routine shown in FIG. 12 instead of step S43 of the refresh control routine. First, in step S431, the accumulator pressure Pacc detected by the accumulator pressure sensor 101 is read, and the value is stored in the memory as the initial pressure Pacc1. Subsequently, in step S432, current control of the pressure-increasing linear control valve 67 is started. In this case, current control is performed with the target current value i * shown in FIG. However, after the set time t1 has elapsed since the start of energization, the target current value i * at that time is maintained.

  Subsequently, in step S433, the brake ECU 100 reads the accumulator pressure Pacc detected by the accumulator pressure sensor 101, and calculates an accumulator pressure fluctuation amount ΔPacc that is a decrease from the initial pressure Pacc1. Subsequently, in step S434, when the pump 31 is operating, the pump supply flow rate Qpon from the start of this flow control routine (start of step S431) is calculated. Subsequently, in step S435, the brake ECU 100 calculates the estimated flow rate Qx that has passed through the pressure-increasing linear control valve 67 using the above formula.

  Subsequently, in step S436, the brake ECU 100 determines whether or not the estimated flow rate Qx is equal to or higher than the preset refresh setting flow rate Q0, and the process proceeds from step S432 to step S436 until the estimated flow rate Qx becomes equal to or higher than the refresh setting flow rate Q0. Repeat the process. Thus, when the estimated flow rate Qx reaches the refresh set flow rate Q0, the brake ECU 100 switches the target current value i * of the pressure-increasing linear control valve 67 to that for valve closing operation in step S437. That is, the target current value i * in the period t3 in FIG. 9 is set. Thus, when the target current value i * is gradually decreased to 0, the brake ECU 100 exits the flow control routine and advances the process to step S44 of the main routine.

  According to the first modification, the flow rate of the hydraulic fluid that passes through the ABS pressure reducing valve 63 can be controlled to a desired flow rate that is not excessive or insufficient. Therefore, the refresh process can be performed more appropriately.

<Modification 2>
In the present embodiment, in the refresh control routine, the ABS pressure reducing valves 63FR, 63FL, 63RR, 63RL are opened once in order to perform the refresh process. In the second modification, as shown in FIG. In addition, it is divided into several times. The foreign matter removal performance depends not only on the flow rate for passing the hydraulic fluid but also on the flow rate fluctuation. Therefore, the foreign matter removal performance is better when the hydraulic fluid is flowed in multiple times in a short time than when the hydraulic fluid is flowed once for a long time. Thereby, the foreign matter clogged in the ABS pressure reducing valve 63 can be satisfactorily removed within a limited time. In the example of FIG. 11, the valve for refreshing is opened twice continuously for each of the ABS pressure reducing valves 63FR, 63FL, 63RR, 63RL, but the ABS pressure reducing valves 63FR, 63FL, 63RR, 63RL are After the opening for refreshing is performed once in order, the same opening for refreshing may be repeated again. The number of divisions for the refresh process can be arbitrarily set.

<Modification 3>
In the present embodiment, the refresh control routine is executed once only when a leakage abnormality of the ABS pressure reducing valve 63 is detected. However, in the third modification example, once every n trips ( (n: natural number) The refresh control routine is periodically executed. For example, the brake ECU 100 counts the number of times the system is started, and only when the count value is a multiple of n, the refresh control is performed after the valve abnormality inspection routine ends even if no abnormality is detected in the valve abnormality inspection routine. A routine (the same processing as S30) is executed. In this case, n = 1, that is, the refresh control routine may be executed at the end of each trip.

<Modification 4>
In the present embodiment, the valve abnormality inspection routine is executed every time the ignition switch is turned off. However, in the fourth modification, for example, the valve is operated only once every n trips (n is an integer of 2 or more). Set to perform an abnormal inspection routine. For example, the brake ECU 100 counts the number of system activations, and executes the valve abnormality inspection routine only when the count value is a multiple of n when the ignition switch is turned off.

<Modification 5>
In this embodiment, when the refresh control routine is started, if the accumulator pressure Pacc, which is the hydraulic pressure output from the power hydraulic pressure generator 30, has not reached the specified pressure Pacc0, the process waits until the specified pressure Pacc0 is exceeded. However, in the fifth modification, the brake ECU 100 detects the accumulator pressure Pacc at a predetermined cycle even during the execution of the refresh control routine, and once the accumulator pressure Pacc is equal to or lower than the specified pressure Pacc1, the refresh process is performed. Is waited until the accumulator pressure Pacc becomes equal to or higher than the predetermined pressure Pacc2. In this case, the determination threshold value (predetermined pressure Pacc2) for resuming the refresh process may be set to a value higher than the determination threshold value (specified pressure Pacc1) for interrupting the refresh process by a differential amount.

  The brake control device according to this embodiment and the modification has been described above, but the present invention is not limited to the above-described embodiment and modification, and various modifications can be made without departing from the object of the present invention. .

  For example, the brake control device of the present embodiment is applied to a hybrid vehicle, but may be applied to an electric vehicle (EV). Even in this case, the brake regeneration cooperative control can be executed.

  In the present embodiment, the valve abnormality inspection routine is executed after the ignition switch is turned off. However, the valve abnormality inspection routine is executed when the vehicle is stopped while the ignition switch is on. May be.

  In this embodiment, when a leakage abnormality of the front wheel ABS pressure reducing valve 63FR (63FL) is detected, the refreshing process of the pressure reducing linear control valve 68 is also executed, but the pressure reducing linear control valve 68 is refreshed. A configuration in which processing is not executed may be used.

  In the present embodiment, during the refresh process, the current of the pressure-increasing linear control valve 67 is gradually increased during the valve opening operation and gradually decreased during the valve closing operation, so that the valve opening operation and the valve closing operation are gradually performed. However, for example, such current control may be performed only during the valve opening operation or only during the valve closing operation. Further, in both the valve opening operation and the valve closing operation, the current may be switched instantaneously.

  In this embodiment, the linear control valve including the pressure-increasing linear control valve 67 and the pressure-decreasing linear control valve 68 is applied to a brake control device that controls the wheel cylinder pressure of the four wheels in common. A brake control device that has a separate linear control valve for each of the four wheels in the hydraulic circuit, and adjusts the hydraulic pressure of the hydraulic fluid pressurized by the power hydraulic pressure source for each wheel using the linear control valve and transmits it to the wheel cylinder You may apply to.

  DESCRIPTION OF SYMBOLS 10 ... Brake pedal, 11 ... Master piping, 12 ... Regulator piping, 13 ... Accumulator piping, 14 ... Reservoir piping, 20 ... Master cylinder unit, 21 ... Hydraulic booster, 22 ... Master cylinder, 23 ... Regulator, 24 ... Reservoir, DESCRIPTION OF SYMBOLS 25 ... Relief valve, 30 ... Power hydraulic pressure generator, 31 ... Pump, 32 ... Accumulator, 33 ... Motor, 42FR, 42FL, 42RR, 42RL ... Wheel cylinder, 50 ... Hydraulic control valve device, 51FR, 51FL, 51RR, 51RL: Individual channel, 52 ... Main channel, 521 ... First main channel, 522 ... Second main channel, 53 ... Master channel, 54 ... Regulator channel, 55 ... Accumulator channel, 56FR, 56FL, 56RR, 56RL ... Individual flow path for pressure reduction, 57 ... Reservoir flow path, 61FR, 61FL, 61 R, 61RL: ABS holding valve, 63FR, 63FL, 63RR, 63RL ... ABS pressure reducing valve, 64 ... communication valve, 65 ... master cut valve, 66 ... regulator cut valve, 67 ... pressure increasing linear control valve, 68 ... pressure reducing linear control Valve: 70 ... Stroke simulator, 100 ... Brake ECU, 101 ... Accumulator pressure sensor, 102 ... Regulator pressure sensor, 103 ... Control pressure sensor, 104 ... Stroke sensor.

Claims (8)

A plurality of wheel cylinders that are provided on each of the plurality of wheels and receive the hydraulic pressure of the hydraulic fluid to give the wheels braking force;
A pedal force hydraulic circuit for transmitting hydraulic pressure of hydraulic fluid pressurized by the pedal force input to the brake pedal to the plurality of wheel cylinders;
A power hydraulic pressure source that pressurizes the hydraulic fluid regardless of the operation of the brake pedal;
A control hydraulic circuit that regulates the hydraulic pressure of the hydraulic fluid pressurized by the power hydraulic pressure source by a linear control valve and transmits the pressure to the plurality of wheel cylinders;
Mode switching means for switching between a control hydraulic pressure mode for generating braking force on the wheels using the control hydraulic pressure circuit and a backup mode for generating braking force on the wheels using the pedal effort hydraulic pressure circuit;
A pressure reducing valve that is provided corresponding to each wheel cylinder, and reduces the wheel cylinder pressure by returning the hydraulic fluid of the wheel cylinder to the reservoir flow path;
Pressure reducing valve abnormality inspection means for inspecting leakage abnormality of the pressure reducing valve;
When the abnormality of the pressure reducing valve is detected by the pressure reducing valve abnormality inspecting means, the pressure reducing valve is used by using the control hydraulic circuit to remove the foreign matter clogged in the pressure reducing valve without switching to the backup mode. Refreshing means for performing a refreshing process, which is a process of allowing the working fluid to pass through,
After the refresh process by the refresh means, the pressure reducing valve abnormality reinspecting means for reinspecting the leakage abnormality of the pressure reducing valve,
If the leakage abnormality of the pressure reducing valve is detected by the pressure reducing valve abnormality reinspection means be despite refresh processing by said refresh means, Bei example a mode transition command means for shifting to said backup mode,
The refresh unit is configured to execute the refresh process by limiting the period from system start to system stop as one trip, and once per trip . A plurality of wheel cylinders that are provided on each of the plurality of wheels and receive the hydraulic pressure of the hydraulic fluid to give the wheels braking force;
A pedal force hydraulic circuit for transmitting hydraulic pressure of hydraulic fluid pressurized by the pedal force input to the brake pedal to the plurality of wheel cylinders;
A power hydraulic pressure source that pressurizes the hydraulic fluid regardless of the operation of the brake pedal;
A control hydraulic circuit that regulates the hydraulic pressure of the hydraulic fluid pressurized by the power hydraulic pressure source by a linear control valve and transmits the pressure to the plurality of wheel cylinders;
Mode switching means for switching between a control hydraulic pressure mode for generating braking force on the wheels using the control hydraulic pressure circuit and a backup mode for generating braking force on the wheels using the pedal effort hydraulic pressure circuit;
A pressure reducing valve that is provided corresponding to each wheel cylinder, and reduces the wheel cylinder pressure by returning the hydraulic fluid of the wheel cylinder to the reservoir flow path;
Pressure reducing valve abnormality inspection means for inspecting leakage abnormality of the pressure reducing valve;
When the abnormality of the pressure reducing valve is detected by the pressure reducing valve abnormality inspecting means, the pressure reducing valve is used by using the control hydraulic circuit to remove the foreign matter clogged in the pressure reducing valve without switching to the backup mode. Refreshing means for performing a refreshing process, which is a process of allowing the working fluid to pass through,
After the refresh process by the refresh means, the pressure reducing valve abnormality reinspecting means for reinspecting the leakage abnormality of the pressure reducing valve,
If the leakage abnormality of the pressure reducing valve is detected by the pressure reducing valve abnormality reinspection means be despite refresh processing by said refresh means, Bei example a mode transition command means for shifting to said backup mode,
The refresh means opens the linear control valve when opening the linear control valve so that the hydraulic fluid output from the power pressurization source flows to the pressure reducing valve at the start of the refresh process. A brake control device comprising valve opening current control means for controlling a current of the linear control valve so as to gradually increase a current value from a predetermined current value lower than a necessary current value . A plurality of wheel cylinders that are provided on each of the plurality of wheels and receive the hydraulic pressure of the hydraulic fluid to give the wheels braking force;
A pedal force hydraulic circuit for transmitting hydraulic pressure of hydraulic fluid pressurized by the pedal force input to the brake pedal to the plurality of wheel cylinders;
A power hydraulic pressure source that pressurizes the hydraulic fluid regardless of the operation of the brake pedal;
A control hydraulic circuit that regulates the hydraulic pressure of the hydraulic fluid pressurized by the power hydraulic pressure source by a linear control valve and transmits the pressure to the plurality of wheel cylinders;
Mode switching means for switching between a control hydraulic pressure mode for generating braking force on the wheels using the control hydraulic pressure circuit and a backup mode for generating braking force on the wheels using the pedal effort hydraulic pressure circuit;
A pressure reducing valve that is provided corresponding to each wheel cylinder, and reduces the wheel cylinder pressure by returning the hydraulic fluid of the wheel cylinder to the reservoir flow path;
Pressure reducing valve abnormality inspection means for inspecting leakage abnormality of the pressure reducing valve;
When the abnormality of the pressure reducing valve is detected by the pressure reducing valve abnormality inspecting means, the pressure reducing valve is used by using the control hydraulic circuit to remove the foreign matter clogged in the pressure reducing valve without switching to the backup mode. Refreshing means for performing a refreshing process, which is a process of allowing the working fluid to pass through,
After the refresh process by the refresh means, the pressure reducing valve abnormality reinspecting means for reinspecting the leakage abnormality of the pressure reducing valve,
If the leakage abnormality of the pressure reducing valve is detected by the pressure reducing valve abnormality reinspection means be despite refresh processing by said refresh means, Bei example a mode transition command means for shifting to said backup mode,
The refresh means opens the linear control valve when closing the linear control valve so as to stop the working fluid flowing from the power pressurization source to the pressure reducing valve at the end of the refresh process. A brake control device comprising valve closing current control means for controlling the current of the linear control valve so as to gradually decrease the current value from a predetermined current value higher than the current value necessary for closing the valve. . A plurality of wheel cylinders that are provided on each of the plurality of wheels and receive the hydraulic pressure of the hydraulic fluid to give the wheels braking force;
A pedal force hydraulic circuit for transmitting hydraulic pressure of hydraulic fluid pressurized by the pedal force input to the brake pedal to the plurality of wheel cylinders;
A power hydraulic pressure source that pressurizes the hydraulic fluid regardless of the operation of the brake pedal;
A control hydraulic circuit that regulates the hydraulic pressure of the hydraulic fluid pressurized by the power hydraulic pressure source by a linear control valve and transmits the pressure to the plurality of wheel cylinders;
Mode switching means for switching between a control hydraulic pressure mode for generating braking force on the wheels using the control hydraulic pressure circuit and a backup mode for generating braking force on the wheels using the pedal effort hydraulic pressure circuit;
A pressure reducing valve that is provided corresponding to each wheel cylinder, and reduces the wheel cylinder pressure by returning the hydraulic fluid of the wheel cylinder to the reservoir flow path;
Pressure reducing valve abnormality inspection means for inspecting leakage abnormality of the pressure reducing valve;
When the abnormality of the pressure reducing valve is detected by the pressure reducing valve abnormality inspecting means, the pressure reducing valve is used by using the control hydraulic circuit to remove the foreign matter clogged in the pressure reducing valve without switching to the backup mode. Refreshing means for performing a refreshing process, which is a process of allowing the working fluid to pass through,
After the refresh process by the refresh means, the pressure reducing valve abnormality reinspecting means for reinspecting the leakage abnormality of the pressure reducing valve,
If the leakage abnormality of the pressure reducing valve is detected by the pressure reducing valve abnormality reinspection means be despite refresh processing by said refresh means, Bei example a mode transition command means for shifting to said backup mode,
The brake control device according to claim 1, wherein the refresh means includes valve closing timing setting means for closing the pressure reducing valve after closing the linear control valve when the refresh process is finished. A plurality of wheel cylinders that are provided on each of the plurality of wheels and receive the hydraulic pressure of the hydraulic fluid to give the wheels braking force;
A pedal force hydraulic circuit for transmitting hydraulic pressure of hydraulic fluid pressurized by the pedal force input to the brake pedal to the plurality of wheel cylinders;
A power hydraulic pressure source that pressurizes the hydraulic fluid regardless of the operation of the brake pedal;
A control hydraulic circuit that regulates the hydraulic pressure of the hydraulic fluid pressurized by the power hydraulic pressure source by a linear control valve and transmits the pressure to the plurality of wheel cylinders;
Mode switching means for switching between a control hydraulic pressure mode for generating braking force on the wheels using the control hydraulic pressure circuit and a backup mode for generating braking force on the wheels using the pedal effort hydraulic pressure circuit;
A pressure reducing valve that is provided corresponding to each wheel cylinder, and reduces the wheel cylinder pressure by returning the hydraulic fluid of the wheel cylinder to the reservoir flow path;
Pressure reducing valve abnormality inspection means for inspecting leakage abnormality of the pressure reducing valve;
When the abnormality of the pressure reducing valve is detected by the pressure reducing valve abnormality inspecting means, the pressure reducing valve is used by using the control hydraulic circuit to remove the foreign matter clogged in the pressure reducing valve without switching to the backup mode. Refreshing means for performing a refreshing process, which is a process of allowing the working fluid to pass through,
After the refresh process by the refresh means, the pressure reducing valve abnormality reinspecting means for reinspecting the leakage abnormality of the pressure reducing valve,
If the leakage abnormality of the pressure reducing valve is detected by the pressure reducing valve abnormality reinspection means be despite refresh processing by said refresh means, Bei example a mode transition command means for shifting to said backup mode,
The brake control device according to claim 1, wherein the refresh unit divides and executes the refresh process so that a series of changes in the flow rate of the hydraulic fluid passing through the pressure reducing valve is generated a plurality of times . The control hydraulic circuit includes a main flow path connected to the power hydraulic pressure source and provided with the linear control valve, an individual flow path branched from the main flow path and connected to each wheel cylinder, and the individual flow And an open / close valve that opens and closes the road,
6. The refresh unit according to claim 1, wherein the refresh unit performs the refresh process one by one for all the pressure reducing valves by opening the on-off valves one by one. brake control device as claimed. The refresh means waits until the hydraulic pressure output from the power pressurization source rises above a predetermined pressure when the hydraulic pressure output from the power pressurization source drops below a specified pressure. The brake control device according to any one of claims 1 to 6, further comprising securing means . The refresh means estimates a refresh flow rate representing a flow rate that has flowed to the pressure reducing valve during the refresh process, and terminates the refresh process of the pressure reducing valve when the estimated refresh flow rate reaches a set flow rate. The brake control device according to any one of claims 1 to 7, further comprising:

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