JP6589442B2 - Brake device - Google Patents

Description

  The present invention relates to a brake device capable of performing automatic pressurization with high response to a control request.

  Conventionally, in Patent Documents 1 and 2, brake devices capable of performing automatic pressurization have been proposed. In these brake devices, automatic pressurization is performed by driving a brake actuator installed between a master cylinder (hereinafter referred to as M / C) and a wheel cylinder (hereinafter referred to as W / C). Specifically, the brake actuator includes a control valve that shuts off the pipe line between the M / C and the W / C, and a brake fluid that is sucked from the M / C, and between the control valve and the W / C. A pump for discharging, a motor for driving the pump, and the like are provided. Then, while blocking between M / C and W / C by the control valve, the pump is driven based on the motor operation to supply the brake fluid from the M / C side to the W / C side. / C is automatically pressurized. When automatic pressurization is performed by pump driving based on such motor operation, automatic pressurization based on highly accurate pressure regulation can be performed.

  Moreover, in the brake device shown in patent document 2, the collision avoidance is performed by applying the automatic brake by automatic pressurization according to the distance between the subject vehicle and the object that can collide. When performing such collision avoidance control, the pressurization response changes according to the temperature of the brake fluid, so that the time at which automatic pressurization is started earlier as the brake fluid temperature is lower, The reference value for determining that the host vehicle can collide with the target is corrected so that collision avoidance can be accurately performed even at low temperatures.

JP 2008-302717 A JP 2013-249047 A

  However, in a system for performing collision avoidance, particularly in a system for performing collision avoidance on a vehicle having a large vehicle weight, higher pressurization response is required, and it is necessary to increase the capacity of a motor for driving a pump. .

  On the other hand, if the automatic pressurization is performed from a region where there is a margin before the collision prediction time when the vehicle is predicted to collide with the object, collision avoidance can be accurately performed without increasing the capacity of the motor. However, since the braking force based on the automatic pressurization is generated from an early stage, an interference with the case where the driver tries to generate the braking force by performing the braking operation himself / herself occurs.

  In this example, collision avoidance control is described as an example, but when performing brake control that requires high response, high response brake control is performed while suppressing interference with the driver's brake operation. If so, the same problem may occur for other brake controls.

  In view of the above points, the present invention eliminates the need to increase the capacity of the motor, suppresses interference with the brake operation by the driver, and provides a high response to the braking force based on automatic pressurization in response to a control request. An object of the present invention is to provide a brake device that can be generated.

  In order to achieve the above object, according to the first aspect of the present invention, the accumulator is connected to the main line connecting the M / C and the W / C, and is accumulated in the accumulator that stores the increased brake fluid pressure. A suction unit for controlling the W / C pressure applied to the W / C based on the pressure, and a suction / discharge operation of brake fluid by a pump provided between the pressure unit and the W / C and driven by a motor. A control unit that controls the W / C pressure based on the control unit, and a control unit that acquires an index value indicating the possibility of collision between the host vehicle and the object. The control unit performs a collision based on the index value. When the possibility of collision is relatively low, the control unit performs a pre-brake operation to move the piston provided in the W / C to the side where the braking force is generated, and when the possibility of collision is relatively high, the pressure unit In It is characterized by generating the W / C pressure, based on the accumulator pressure me.

  In this way, the precharge operation is performed by driving the control unit when the possibility of a collision between the host vehicle and the object is relatively low. And when the possibility of collision between the host vehicle and the object is relatively high, the braking force is generated with high response by driving the pressure unit. Thereby, since the operation based on the drive of the motor in the control unit can be performed only in the pre-brake operation, high pressurization response is not required. Therefore, it is possible to generate a braking force with a high response when the possibility of a collision is relatively high, and to eliminate the need for a large capacity motor. Also. Since it is not necessary to perform automatic pressurization using the pressurization unit from an early stage, it is possible to suppress the occurrence of interference with the case where the driver tries to generate the braking force by performing the braking operation himself.

In the invention according to claim 2, the pressurizing unit is provided in the main pipeline, a control valve for controlling the flow state of the brake fluid in the main pipeline, a hydraulic pump for pumping the brake fluid to the accumulator, An electric motor that drives the hydraulic pump; a piston portion that is provided on the W / C side of the main line with respect to the control valve, and that causes the accumulator pressure to act on the W / C to generate the W / C pressure; and the accumulator And a pressure increasing solenoid valve that controls the flow state of the brake fluid in a pipe line connecting the piston portion and the control portion when the possibility of a collision is relatively high, It is characterized in that the W / C pressure is generated based on the accumulator pressure by bringing the pipe line connecting the piston portion into a communicating state.

  In this way, the W / C pressure is generated by applying the accumulator pressure to the piston portion, and provided in the pipe line connecting the accumulator and the piston portion when the possibility of collision is relatively high. By setting the pressure-increasing electromagnetic valve in the communication state, it becomes possible to generate the W / C pressure with high response based on the high pressure accumulator pressure.

According to a third aspect of the present invention, the pressurizing unit controls the flow state of the brake fluid in a pipe line connecting the accumulator and the piston portion as a pressure increasing solenoid valve, and a plurality of pressure increasing solenoid valves arranged in parallel. The control unit is characterized in that when the possibility of a collision is relatively high, any or all of the plurality of pressure-increasing electromagnetic valves are brought into communication.

  As described above, a plurality of pressure-increasing solenoid valves are provided in parallel in the pipe line connecting the accumulator and the piston portion, and when the possibility of a collision is relatively high, By making all the communication state, it becomes possible to generate the W / C pressure with higher response.

  In addition, the code | symbol in the bracket | parenthesis of each said means shows an example of a corresponding relationship with the specific means as described in embodiment mentioned later.

1 is a hydraulic circuit diagram showing a basic configuration of a brake device according to a first embodiment of the present invention. It is the hydraulic circuit diagram which showed the detail of the control unit. It is the hydraulic-pressure circuit diagram which showed the detail of the pressurization unit. It is the block diagram which showed the structural example of various sensors with which a vehicle including brake ECU is equipped, and ECU. It is a time chart showing operation of a brake equipment based on collision avoidance control. It is a time chart when the brake operation by a driver is not performed before control. It is a time chart when ABS control is not performed at the time of collision avoidance control. It is a time chart when rear-wheel ABS control is performed at the time of collision avoidance control. It is the hydraulic circuit diagram which showed the detail of the pressurization unit with which the brake device demonstrated in other embodiment is equipped. It is the hydraulic circuit diagram which showed the detail of the pressurization unit with which the brake device demonstrated in other embodiment is equipped.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, parts that are the same or equivalent to each other will be described with the same reference numerals.

(First embodiment)
Hereinafter, the brake device for vehicles concerning a 1st embodiment of the present invention is explained. FIG. 1 is a hydraulic circuit diagram showing a basic configuration of a brake device 1 according to the present embodiment. Here, although the example which applied the brake device 1 concerning this invention to the vehicle which comprises the hydraulic pressure circuit of front and rear piping is demonstrated, it is applicable also to vehicles, such as X piping.

  As shown in FIG. 1, the brake device 1 includes a brake pedal 11, a booster device 12, M / C 13, W / C 14, 15, 34, 35, a control unit 50, a pressurizing unit 60, a brake ECU 70, and a booster. A pressure ECU 80 and the like are provided. 2 and 3 are diagrams showing details of the control unit 50 and the pressurizing unit 60, respectively.

  The brake pedal 11 that is depressed by the driver when applying braking force to the vehicle is connected to the booster 12 and the M / C 13. When the driver depresses the brake pedal 11, the booster 12 boosts the pedaling force. Then, the master pistons 13a and 13b disposed in the M / C 13 are pressed. Thereby, the same M / C pressure is generated in the primary chamber 13c and the secondary chamber 13d defined by the master pistons 13a and 13b. The M / C 13 is provided with a master reservoir 13e having passages communicating with the primary chamber 13c and the secondary chamber 13d, respectively, and supply of brake fluid to the M / C 13 and excess brake fluid from the M / C 13 It can be discharged.

  The M / C pressure generated in the M / C 13 is transmitted to each W / C 14, 15, 34, 35 through the pressurizing unit 60 and the control unit 50. As the control unit 50, an existing one can be used. The existing control unit 50 is arranged between the M / C 13 and the W / C 14, 15, 34, 35, and the M / C 13 and the control unit 50 The brake device 1 can be configured by additionally disposing the pressure unit 60 between the two.

  The control unit 50 is configured to include a first piping system 50a and a second piping system 50b. The first piping system 50a controls the brake fluid pressure of the front W / Cs 14, 15 provided on the left and right front wheels FL, FR, and the second piping system 50b is provided on the left and right rear wheels RL, RR. The brake fluid pressure of the rear W / C 34, 35 is controlled.

  Hereinafter, the first and second piping systems 50a and 50b will be described. However, since the first piping system 50a and the second piping system 50b have substantially the same configuration, the first piping system 50a will be described here. For the second piping system 50b, refer to the first piping system 50a.

  The first piping system 50a serves as a main pipeline that transmits the above-described M / C pressure to the W / C 14 provided on the left front wheel FL and the W / C 15 provided on the right front wheel FR to generate the W / C pressure. Pipe line A is provided.

  By controlling the pipeline A to the communication state and the differential pressure state, the pipeline A is connected between the upstream side of the pipeline A with the M / C 13 side on the upstream side and the W / C 14 and 15 side on the downstream side. A first differential pressure control valve 16 that controls the differential pressure is provided. The first differential pressure control valve 16 is used during normal braking when the driver operates the brake pedal 11 (when vehicle motion control such as collision avoidance control or antilock brake (hereinafter referred to as ABS) control is not executed). The valve position is adjusted so as to be in the communication state, and when a current is passed through the solenoid coil provided in the first differential pressure control valve 16, the valve position is set so that the larger the current value, the larger the differential pressure state. Adjusted.

  When the first differential pressure control valve 16 is in the differential pressure state, only when the brake fluid pressure on the W / C 14, 15 side is higher than the M / C pressure by a predetermined level or more, the M / C 13 from the W / C 14, 15 side is used. Brake fluid flow to the side is allowed. For this reason, the W / C 14, 15 side is always maintained so as not to be higher than the predetermined pressure by the M / C 13 side. Further, a check valve 16 a is provided in parallel with the first differential pressure control valve 16.

  The pipe A branches into two pipes A1 and A2 on the W / C 14 and 15 side downstream of the first differential pressure control valve 16. The pipeline A1 is provided with a first pressure increase control valve 17 that controls the increase of the brake fluid pressure to the W / C 14, and the pipeline A2 is a first pressure that controls the increase of the brake fluid pressure to the W / C 15. A two pressure increase control valve 18 is provided.

  The first and second pressure increase control valves 17 and 18 are constituted by two-position solenoid valves that can control the communication / blocking state. Specifically, the first and second pressure increase control valves 17 and 18 are set when the control current to the solenoid coils provided in the first and second pressure increase control valves 17 and 18 is zero (during non-energization). ) Is in a communication state, and is a normally open type that is controlled to be cut off when a control current is passed through the solenoid coil (when energized). That is, the first and second pressure increase control valves 17 and 18 are turned on when energized to block the flow of brake fluid, and are turned off when deenergized to allow the flow of brake fluid.

  In the pipeline A, the first and second pressure-increasing control valves 17 and 18 and the pipeline B serving as a pressure-reducing pipeline connecting between the W / Cs 14 and 15 and the pressure regulating reservoir 20 are controlled in the communication / blocking state. The 1st pressure reduction control valve 21 and the 2nd pressure reduction control valve 22 which are comprised by the 2 position solenoid valve which can be each arrange | positioned. The first and second pressure reduction control valves 21 and 22 are cut off when the control current to the solenoid coils provided in the first and second pressure reduction control valves 21 and 22 is zero (when no power is supplied). When the control current is supplied to the solenoid coil (when energized), it is a normally closed type that is controlled to be in a communication state. That is, the first and second pressure reduction control valves 21 and 22 are turned on when energized to allow the flow of brake fluid, and are turned off when not energized to block the flow of brake fluid.

  A conduit C serving as a reflux conduit is disposed between the pressure regulating reservoir 20 and a conduit A serving as a main conduit. A self-priming pump 19 driven by a motor 51 that sucks and discharges brake fluid from the pressure regulating reservoir 20 toward the M / C 13 side or the W / C 14, 15 side is provided in the pipe line C. The motor 51 is driven by controlling energization to a motor relay (not shown).

  A conduit D serving as an auxiliary conduit is provided between the pressure regulating reservoir 20 and the M / C 13. The brake fluid is sucked from the M / C 13 by the pump 19 through this pipeline D and discharged to the pipeline A, so that the brake fluid is supplied to the W / C 14, 15 side during vehicle motion control. It is possible to pressurize the W / C pressure of the wheel.

  In addition, although the 1st piping system 50a was demonstrated here, the 2nd piping system 50b is also the same structure, The 2nd piping system 50b is also provided with the structure similar to each structure with which the 1st piping system 50a was equipped. Yes. Specifically, the second differential pressure control valve 36 and the check valve 36a corresponding to the first differential pressure control valve 16 and the check valve 16a, the third corresponding to the first and second pressure increase control valves 17 and 18, respectively. , Fourth pressure increase control valves 37 and 38, first and second pressure reduction control valves 21 and 22, third and fourth pressure reduction control valves 41 and 42, pump 19 and pump 39, pressure regulating reservoir 20 There is a corresponding pressure regulating reservoir 40, lines A to D and corresponding lines E to H. However, for the W / Cs 14, 15, 34, and 35 in which each system 50a, 50b supplies brake fluid, the capacity of the first piping system 50a serving as the front system is larger than that of the first piping system 50b serving as the rear system. It has been enlarged. Thereby, a larger braking force can be generated on the front side.

  The pressurizing unit 60 is disposed between the M / C 13 and the control unit 50. For example, the pressurizing unit 60 can be connected to the pipelines A and E, and the existing configuration in which the control unit 50 is provided between the M / C 13 and the W / C 14, 15, 34, 35. Thus, the brake device 1 can be configured by additionally arranging the pressure unit 60.

  The pressurizing unit 60 includes an auxiliary pressure source 61, various electromagnetic valves 62a, 62b, 63a to 63c, 64, first and second piston portions 65a, 65b, and pressure sensors 66a, 66b. These are configured by being provided in various pipes I to L. And each part with which the pressurization unit 60 is equipped is controlled by pressurization ECU80, The W / C pressure increase / decrease by the pressurization unit 60 can be performed now.

  The auxiliary pressure source 61 includes a hydraulic pump 61a, an accumulator 61b, an electric motor 61c, a reservoir 61d, and a relief valve 61e.

  The hydraulic pump 61a is disposed in the pipeline I that connects the reservoir 61d and the accumulator 61b. The hydraulic pump 61a is driven by the electric motor 61c to suck the brake fluid in the reservoir 61d and pump it to the accumulator 61b side. The brake fluid discharged from the hydraulic pump 61a is supplied to the accumulator 61b and accumulated. The brake fluid pressure accumulated in the accumulator 61b corresponds to the accumulator pressure. Here, the reservoir 61d is independently provided as a brake fluid reservoir for supplying brake fluid to the hydraulic pump 61a. However, the master reservoir 13e can also be used as the reservoir 61d. Further, although the accumulator 61b and the reservoir 61d are provided in the pressurizing unit 60, these can be configured separately.

  The electric motor 61c is driven in response to the accumulator pressure falling below a predetermined lower limit value, thereby increasing the accumulator pressure, and being stopped in response to the accumulator pressure exceeding a predetermined upper limit value. Regarding the accumulator pressure, the detection signal of the pressure sensor 66a is transmitted to the pressurizing ECU 80, and the pressurization ECU 80 drives the electric motor 61c so that the accumulator pressure is adjusted between a predetermined lower limit value and an upper limit value. I have control.

  The relief valve 61e is provided in a pipeline J provided as a bypass passage of the pipeline I so as to connect the accumulator 61b and the reservoir 61d. The relief valve 61e allows the brake fluid to escape from the accumulator 61b side to the reservoir 61d side at a predetermined pressure so that the accumulator pressure does not become excessively high. The relief pressure of the relief valve 61e is set to a value higher than the upper limit value of the accumulator pressure. As described above, the accumulator pressure is basically controlled to be within the range from the predetermined lower limit value to the upper limit value. However, if the accumulator pressure exceeds the upper limit value, the reservoir 61d is passed through the relief valve 61e. Brake fluid escapes to the side.

  The first and second control valves 62a and 62b and the first and second piston portions 65a and 65b are disposed between the M / C 13 and the control unit 50 in the first and second piping systems 50a and 50b. Specifically, the first control valve 62 a and the first piston portion 65 a are connected to the pipe line A and are disposed between the M / C 13 and the first differential pressure control valve 16. The first control valve 62a is disposed on the M / C 13 side with respect to the first piston portion 65a. Further, the second control valve 62b and the second piston portion 65b are connected to the pipe E, and are disposed between the M / C 13 and the second differential pressure control valve 36. The second control valve 62b is disposed on the M / C 13 side with respect to the second piston portion 65b.

  The first and second control valves 62a and 62b control the disconnection of the conduits A and E, respectively, and the control current to the solenoid coils provided in the first and second control valves 62a and 62b is zero. When it is set (when not energized), it is in a communication state, and when a control current is passed through the solenoid coil (when energized), it is a normally open type that is controlled to be in a cut-off state.

  The first and second piston portions 65a and 65b are connected to a pipe line K connected to the accumulator 61b. The pipe K is branched into three from the accumulator 61b, is connected to the first to third pressure-increasing electromagnetic valves 63a to 63c, and further passes through the first to third pressure-increasing electromagnetic valves 63a to 63c, and then the two pipe lines K1 and K2, and the pipelines K1 and K2 and the pipelines A and E are connected via the first and second piston portions 65a and 65b. The first and second piston portions 65a and 65b allow the hydraulic fluid on the pressure unit 60 side and the first and second piping systems 50a and 50b while allowing the brake fluid to flow in the pipes A and E, respectively. And the brake hydraulic pressure on the pressurizing unit 60 side is transmitted to the pipelines A and E.

  Specifically, the first and second piston portions 65a and 65b are arranged on the first chambers 65ab and 65bb and the second chambers 65ac and 65bc, which are defined by the pistons 65aa and 65ba, and the first chambers 65ab and 65bb. Return springs 65ad and 65bd are provided.

  The pistons 65aa and 65ba are urged to return the second chambers 65ac and 65bc by the return springs 65ad and 65bd. Then, when the brake fluid pressure based on the accumulator pressure is transmitted, the pistons 65aa and 65ba are moved to the side where the first chambers 65ab and 65bb are contracted against the urging force of the return springs 65ad and 65bd.

  The first chambers 65ab and 65bb are connected to the pipelines A and E, respectively. The flow of the brake fluid in the pipes A and E is allowed through the first chambers 65ab and 65bb. On the other hand, the second chambers 65ac and 65bc are connected to the conduits K1 and K2, respectively. The brake fluid pressure based on the accumulator pressure can be introduced into the second chambers 65ac and 65bc via the pipelines K1 and K2.

  Further, the pipe K is provided with first to third pressure-increasing electromagnetic valves 63a to 63c constituted by two-position electromagnetic valves capable of controlling the communication / blocking state. The first to third pressure-increasing electromagnetic valves 63a to 63c are cut off when the control current to the solenoid coil provided in the first to third pressure-increasing electromagnetic valves 63a to 63c is zero (when no power is supplied). Thus, when the control current is supplied to the solenoid coil (when energized), the normally closed type is controlled so as to be in a communication state. That is, the first to third pressure increasing solenoid valves 63a to 63c are turned on when energized so that the brake fluid pressure based on the accumulator pressure is applied to the first and second piston portions 65a and 65b, and turned off when deenergized. Thus, application of the brake fluid pressure based on the accumulator pressure to the first to third pressure increasing electromagnetic valves 63a to 63c is limited.

  The first to third pressure-increasing electromagnetic valves 63a to 63c are arranged in parallel and can be controlled independently. The brake fluid from the accumulator 61b is caused to flow to the first and second piston portions 65a and 65b through the one of the first to third pressure increasing solenoid valves 63a to 63c that is turned on. In the case of the present embodiment, the first to third pressure-increasing electromagnetic valves 63a to 63c are the same, that is, the same size of the orifice constituted by the valve body and the valve seat, for example, the same orifice diameter. However, different configurations may be used. When the dimensions of the orifices of the first to third pressure increasing solenoid valves 63a to 63c are made different, the amount of brake fluid flowing from the accumulator 61b side to the first and second piston parts 65a and 65b side can be made different. Any one of the first to third pressure-increasing electromagnetic valves 63a to 63c can be selectively turned on according to the required responsiveness.

  Moreover, the pipe line L connected to the reservoir 61d is connected to the first and second piston parts 65a and 65b side of the pipe lines K1 and K2 from the first to third pressure increasing electromagnetic valves 63a to 63c. A pressure regulating electromagnetic valve 64 capable of controlling the communication / pressure regulating state is disposed in the pipe line L. The pressure regulating solenoid valve 64 is in a communication state when the control current to the solenoid coil provided in the pressure regulating solenoid valve 64 is zero (when not energized), and when the control current flows through the solenoid coil (when energized). ) Is a normally open type controlled to a shut-off state. In other words, the pressure regulating solenoid valve 64 is turned off when not energized so that the brake fluid pressure is not applied to the first and second piston portions 65a and 65b. The brake fluid pressure applied to the parts 65a and 65b is regulated.

  Note that the pressure regulation by the pressure regulating solenoid valve 64 can be performed, for example, by duty-controlling on / off of the pressure regulating solenoid valve 64. Further, when the pressure regulating solenoid valve 64 is configured with a differential pressure control valve that can generate a larger differential pressure as the current value of the current flowing through the solenoid coil is larger, the current value of the current flowing through the solenoid is also controlled. Pressure regulation by the pressure electromagnetic valve 64 can be performed. In the following description, a case where pressure regulation is performed by duty control will be described as an example, but pressure regulation by controlling the magnitude of the current value may be performed.

  In this way, the control unit 50 and the pressure unit 60 are configured. Among these, the control unit 50 is controlled by the brake ECU 70, and the pressurizing unit 60 is controlled by the pressurizing ECU 80. The brake ECU 70 and the pressurization ECU 80 can exchange signals. Here, the pressurization ECU 80 controls the pressurization unit 60 by transmitting a control signal from the brake ECU 70 to the pressurization ECU 80. It has become.

  The brake ECU 70 is configured by a well-known microcomputer having a CPU, ROM, RAM, I / O, and the like, and executes processing such as various calculations in accordance with a program stored in the ROM and the like to respond to a control request from collision avoidance control. The brake control or ABS control corresponding to the response is executed. The pressurizing ECU 80 is also configured by a well-known microcomputer having a CPU, ROM, RAM, I / O, and the like, and executes processing such as various calculations according to a program stored in the ROM, for example, from the brake ECU 70. Various controls are executed based on the control signal.

  Specifically, the brake ECU 70 calculates various physical quantities based on detection signals from sensors (not shown), receives control requests from other ECUs, and performs various processes based on the calculation results and control requests. Yes. For example, it is determined whether or not to execute brake control and ABS control according to a control request from collision avoidance control, and various calculations are performed. When the brake ECU 70 performs the brake control according to the control request from the collision avoidance control, the brake ECU 70 transmits a control signal to that effect to the pressurizing ECU 80. Further, when executing the ABS control during the collision avoidance control, the brake ECU 70 sends a control signal to the pressurizing ECU 80 so that the collision avoidance control and the ABS control can be coordinated while executing the ABS control. I tell you.

  FIG. 4 is a block diagram showing an example of the structure of various sensors and ECUs provided in the vehicle including the brake ECU 70. As shown in the figure, a CAN (Controller Area Network) in which detection signals of a physical quantity sensor 100 such as a collision target recognition sensor 90 such as an obstacle sensor and a front camera for detecting a vehicle surrounding situation and a yaw rate and acceleration sensor are an in-vehicle network. It is input to the collision avoidance ECU 120 through the in-vehicle LAN 110 such as communication. The collision avoidance ECU 120 performs collision avoidance control and issues a control request based on the collision avoidance control. This control request is transmitted to the engine ECU 130 and the brake ECU 70 through the in-vehicle LAN 110. The engine ECU 130 and the brake ECU 70 execute engine control and brake control in response to a control request based on collision avoidance control.

  Specifically, the collision avoidance ECU 120 calculates a relative distance and a relative speed difference between the own vehicle and a target object such as a preceding vehicle, and based on the relative distance and the relative speed difference, the host vehicle detects the target object. The collision prediction time that is predicted to collide with is calculated. Since the calculation method of the relative distance and the relative speed difference and the calculation method of the collision prediction time may be a conventionally known method, the description thereof is omitted here. Then, the collision avoidance ECU 120 compares the predicted collision time with a predetermined first threshold value or a second threshold value shorter than the first threshold value, and when the predicted collision time becomes equal to or less than the first threshold value and below the second threshold value. When this happens, a control signal indicating that is output.

  Further, when executing the collision avoidance control, the collision avoidance ECU 120 calculates, for example, a braking torque to be generated during the collision avoidance control as a control amount. This braking torque is transmitted to the brake ECU 70 as a control request based on the collision avoidance control, and a target W / C pressure necessary to generate the braking torque is calculated.

  Based on this, the brake ECU 70 automatically performs an emergency brake, and the engine ECU 130 executes collision avoidance control such as reducing the engine output.

  Further, the ABS control is executed by the brake ECU 70. The brake ECU 70 determines whether or not to execute ABS control based on the slip ratio of each wheel, and calculates a control amount based on the slip ratio of each wheel. The ABS control is performed regardless of whether or not the collision avoidance control is performed. However, when the ABS control is performed during the collision avoidance control, it is necessary to perform them in cooperation. Therefore, when performing the ABS control during the collision avoidance control, the brake ECU 70 also transmits the control amount of the ABS control to the pressurizing ECU 80.

  The brake device according to the present embodiment is configured as described above. Next, the operation of the brake device of this embodiment will be described.

  First, the operation of the brake device based on the collision avoidance control will be described with reference to the time chart shown in FIG.

  When the collision avoidance ECU 120 determines that the predicted collision time is equal to or less than the first threshold (time point ta in FIG. 5), a control signal to that effect is transmitted to the brake ECU 70 via the in-vehicle LAN 110. In this case, since there is a possibility of applying an emergency brake based on the collision avoidance control, the brake ECU 70 operates the control unit 50 in order to cope with the emergency brake based on the collision avoidance control, that is, a pre-brake operation. I do.

  Specifically, the control unit 50 drives the pumps 19 and 39 by operating the motor 51 to supply the brake fluid to the W / Cs 14, 15, 34, and 35. As a result, the piston in the W / C can be moved, and it is possible to shorten or eliminate a margin time required from the start of the brake operation to the generation of the braking force in the brake device. For example, in the case of a disc brake, a clearance is provided between a brake pad and a brake disc. In this case, the time required to move the brake pad by the clearance is an extra time, that is, a dead zone where the brake is not applied even if the control unit 50 or the pressure unit 60 is driven to apply the brake. For this reason, the brake pad is moved so that the clearance can be reduced or eliminated.

  Even if only the pumps 19 and 39 are driven in the control unit 50, W is based on the resistance of the orifice between the valve body and the valve seat of the first and second differential pressure control valves 16 and 36. Brake fluid can be supplied into / C. For this reason, it is possible to perform the precharge operation without setting the first and second differential pressure control valves 16 and 36 to the differential pressure state. Of course, the first and second differential pressure control valves 16 and 36 may be in a differential pressure state to generate a desired W / C pressure and a deceleration. Since the differential pressure generated by the first and second differential pressure control valves 16 and 36 is equivalent to the W / C pressure, the current value flowing through the solenoids of the first and second differential pressure control valves 16 and 36 is adjusted. Thus, the generated W / C pressure can be adjusted.

  Thereafter, when the collision avoidance ECU 120 determines that the predicted collision time is equal to or less than the second threshold (time tb in FIG. 5), a control signal to that effect is transmitted to the brake ECU 70 via the in-vehicle LAN 110. In this case, in order to apply an emergency brake based on the collision avoidance control, the brake ECU 70 operates the pressurizing unit 60 to generate a W / C pressure based on the accumulator pressure. Specifically, the first and second control valves 62a and 62b are shut off, and the first to third pressure-increasing electromagnetic valves 63a to 63c are appropriately connected. As a result, a W / C pressure based on a high accumulator pressure is generated. Therefore, the W / C pressure can be generated with high response, and the emergency brake according to the collision avoidance control can be applied. The operation at the time of the collision avoidance control differs depending on whether or not the cooperation with the ABS control is performed as will be described later, and the details will be described later.

  Next, a state before the collision avoidance control and the ABS control are executed, and a specific operation of the brake device when these are executed will be described. FIGS. 6 to 8 show accumulator pressure (Acc pressure), front wheel FL, FR side W / C pressure, rear wheel RL, RR side W / C pressure, and operating time of each solenoid valve according to the operating state. It is a chart.

  First, when vehicle motion control such as collision avoidance control or ABS control is not executed and the brake pedal 11 is not depressed by the driver, the accumulator pressure is maintained within a predetermined range as shown in the time chart of FIG. The W / C pressures of the front wheels FL and FR and the rear wheels RL and RR are not generated.

  If the driver depresses the brake pedal 11 in this state, the collision avoidance control is not executed, and if the ABS control is not executed, the operation is performed during normal braking. That is, during normal braking, the control unit 50 and the pressurizing unit 60 are not operated, and the various valves are also in the illustrated positions. For this reason, when the M / C 13 M / C pressure is generated based on the depression of the brake pedal 11, the M / C pressure is transmitted to the W / Cs 14, 15, 34, 35 through the pipes A, E. Based on this, a desired braking force according to the depression of the brake pedal 11 by the driver is generated.

  In this case, when the wheel slip rate increases and the ABS control is started, the operation based on the ABS control similar to the conventional one is performed. For example, a pressure reduction mode, a holding mode, and a pressure increase mode are set for the wheels to be controlled by ABS control according to the slip rate. In the decompression mode, the pressure increase control valves 17, 18, 37, 38 corresponding to the wheels to be controlled are shut off, and the pressure reduction control valves 21, 22, 41, 42 are appropriately brought into communication so that the W / C The pressure is reduced. In the holding mode, the pressure increase control valves 17, 18, 37, and 38 and the pressure reduction control valves 21, 22, 41, and 42 corresponding to the wheel to be controlled are shut off and the W / C pressure is held. Further, in the pressure increasing mode, the pressure reducing control valves 21, 22, 41, and 42 corresponding to the wheel to be controlled are shut off and the pressure increasing control valves 17, 18, 37, 38 are appropriately connected. Thus, the W / C pressure is increased. In this way, the slip of each wheel is controlled and the wheel is prevented from being locked.

  On the other hand, regardless of whether or not the brake pedal 11 is depressed by the driver, if the condition for collision avoidance control is satisfied, control for automatically applying an emergency brake is performed. Specifically, the first and second control valves 62a and 62b are shut off, and the first and second pressure increasing solenoid valves 63a to 63c are appropriately connected.

  Accordingly, the pistons 65aa and 65ba of the first and second piston portions 65a and 65b are moved to the side of contracting the first chambers 65ab and 65bb against the return springs 65ad and 65bd based on the high accumulator pressure. The accumulator pressure is regulated by selecting and turning on any or all of the first to third pressure increasing electromagnetic valves 63a to 63c, and the target W / C pressure is equivalent to the first and second piston portions 65a. , 65b and further to pipes A and E.

  Therefore, as shown in FIG. 7, it is possible to generate a W / C pressure corresponding to the target W / C pressure in the W / C 14, 15, 34, 35 of the front and rear wheels FL to RR. Since the W / C pressure is generated based on the high accumulator pressure, it is possible to increase the W / C pressure with high step-up response as shown at time points t1 to t2 in the figure. Therefore, emergency braking can be automatically applied, and collision with an obstacle can be avoided or damage caused by collision can be reduced.

  Further, since the deceleration obtained by the automatic pressurization by the collision avoidance control can be monitored based on the detection signal of the acceleration sensor included in the physical quantity sensor 100, for example, the difference between the deceleration indicated by the control request and the actual deceleration is shown. Based on this, it is possible to estimate whether automatic pressurization is performed as required by the control. If only a deceleration that does not satisfy the control request is obtained, for example, by increasing the number of the first to third pressure-increasing electromagnetic valves 63a to 63c that are turned on, the automatic pressurization according to the control request is performed. It is preferable to perform feedback control as shown.

  At this time, the responsiveness of the brake fluid pressure, that is, the rising gradient can be changed according to the number of the first to third pressure increasing solenoid valves 63a to 63c that are turned on. You can change the number to turn on. For example, among the first to third pressure-increasing electromagnetic valves 63a to 63c, for example, the faster the change gradient of the collision prediction time, the more the number of ones to be turned on among the first to third pressure-increasing electromagnetic valves 63a to 63c. The number of items to be turned on can be adjusted as appropriate.

  Further, if the number of the first to third pressure increasing solenoid valves 63a to 63c to be turned on is increased, the accumulator pressure can be applied to the first and second piston portions 65a and 65b as they are. However, the vehicle can be controlled to stop at an appropriate position by appropriately adjusting the number of the first to third pressure increasing electromagnetic valves 63a to 63c that are turned on. For this reason, it becomes possible to suppress the influence on a back vehicle rather than the case where a sudden brake is applied.

  Thereafter, the W / C pressure is maintained by shutting off the first to third pressure increasing solenoid valves 63a to 63c. For example, when the brake ECU 70 informs the pressurizing ECU 80 that the target W / C pressure has decreased, at time t3, the pressure regulating solenoid valve 64 is appropriately controlled to be in a communication state, whereby each wheel FL˜ The RR W / C pressure is lowered and adjusted to the target W / C pressure. Further, when releasing the automatic pressurization based on the accumulator pressure, the piston positions of the first and second piston portions 65a and 65b are restored by returning each electromagnetic valve to the position shown in FIG. 3 and returning the brake fluid to the reservoir 61d. Also returns to the position shown. Thereby, the automatic pressurization of W / C based on the accumulator pressure is released.

  Further, when the ABS control is executed during the collision avoidance control, the pressurizing unit 60 is controlled corresponding to the ABS control. A control method of the pressure unit 60 at this time will be described.

  First, at time points t1 to t2 shown in FIG. 8, collision avoidance control is executed, and W / C pressure is generated for the wheels FL to RR by the same method as at time points t1 to t2 in FIG. When the ABS control is started for the front and rear wheels FL to RR at time t2, the W / C pressures of the front and rear wheels FL to RR are increased or decreased based on the ABS control. Then, at least one of the first to third pressure-increasing electromagnetic valves 63a to 63c is brought into a communication state so that both the first and second piping systems 50a and 50b are connected to the accumulator 61b. If the ABS control is not being performed, the first to third pressure increasing solenoid valves 63a to 63c may be shut off to maintain the target W / C pressure. However, when the ABS control is executed, the brake fluid is consumed during the pressure increasing mode in the ABS control, and the first and second piston portions 65a and 65b are more than the first to third pressure increasing electromagnetic valves 63a to 63c. The high pressure held on the side is immediately eliminated, and the W / C pressure cannot be increased thereafter. For this reason, at least one of the first to third pressure-increasing electromagnetic valves 63a to 63c is kept in a communicating state so that the W / C pressure can be quickly increased in the pressure-increasing mode of the ABS control. .

  In addition, when the W / C pressures of the front and rear wheels FL to RR are increased or decreased by the ABS control, the pistons 65aa and 65ba of the first and second piston portions 65a and 65b are moved in accordance with the pressure fluctuation, so that the pressure The changed amount of brake fluid is returned to the accumulator 61b. As described above, since the brake fluid can be transferred to and from the accumulator 61b, the ABS control can be performed by adjusting the pressure in the first and second piston portions 65a and 65b even when the control unit 50 executes the ABS control at the same time. It is possible to absorb the pressure fluctuation due to the.

  In this way, the brake device according to the present embodiment is operated. In addition, although other vehicle motion control, such as skid prevention control, can also be implemented by this brake device, description is abbreviate | omitted here.

  As described above, in the brake device of the present embodiment, the precharge operation is performed by driving the control unit 50 when the predicted collision time of the vehicle is equal to or shorter than the first threshold value, that is, when the possibility of a collision is relatively low. ing. When the predicted collision time of the vehicle is equal to or shorter than the second threshold, that is, when the possibility of a collision is relatively high, the braking force can be generated with high response by driving the pressure unit 60.

  Thereby, since the operation based on driving of the motor 51 in the control unit 50 can be performed only in the precharge operation, high pressurization responsiveness is not required. Accordingly, the braking force can be generated with a high response when the possibility of a collision is relatively high, and the motor 51 does not have to be increased in capacity. In addition, since it is not necessary to perform automatic pressurization using the pressurization unit 60 from a region where there is a margin until the collision prediction time, that is, from an early stage, the first and second control valves 62a and 62b are in a communication state, and the driver When a driver tries to generate a braking force by himself, the driver's intention can be reflected without a feeling of board (feeling of stepping on a hard board).

  Further, since the precharge operation is performed based on the driving of the motor 51 in the control unit 50, it is possible to control the W / C pressure with higher accuracy than in the case of using a high accumulator pressure. In addition, since the accumulator pressure is not used in the precharge operation, it is possible to reduce the frequency of use of the accumulator 61b and to improve durability.

  Further, in the brake device 1 of the present embodiment, the precharge operation is executed by the control unit 50, and the operation for increasing the W / C pressure with high pressure increase response based on the collision avoidance control is executed by the pressurizing unit 60. Yes. And since such a brake device 1 can be comprised only by providing the pressurization unit 60 between M / C13 and the existing control unit 50 which performs ABS control etc., it is set as the brake device 1 with high versatility. Can do.

  Further, even when pressure fluctuation occurs on the control unit 50 side, such as ABS control, the brake fluid corresponding to the pressure fluctuation can be returned to the accumulator 61b by the movement of the first and second piston portions 65a and 65b. That is, the brake fluid pressure in the control unit 50 is absorbed by the accumulator 61b. For this reason, the control of the control unit 50 and the collision avoidance control can be performed in a coordinated manner.

  Further, the first piping system, the second piping system, and the pressurizing unit 60 are connected via first and second piston portions 65a and 65b, and pressure is transmitted via the first and second piston portions 65a and 65b. Is done. At this time, even if a defect occurs in the pressure unit 60, the pistons 65aa and 65ba are separated from the first chamber 65ab while the first and second piping systems and the pressure unit 60 are partitioned by the pistons 65aa and 65ba. , 65bb can be prevented from being sealed. Therefore, even if a defect occurs in the pressurizing unit 60, it is possible to guarantee the use of a path for transmitting the brake hydraulic pressure from the M / C 13 to the W / C 14, 15, 34, 35 via the control unit 50. It becomes. Therefore, it can be set as a brake device with higher fail-safe property.

(Other embodiments)
The present invention is not limited to the embodiment described above, and can be appropriately changed within the scope described in the claims.

  For example, the collision prediction time has been described as an example of the index value indicating the possibility that the host vehicle collides with the target object in the collision avoidance control. However, instead of the collision prediction time, the relative distance between the host vehicle and the target object, etc. Other index values can also be used. In the above-described embodiment, the collision avoidance ECU 120 constitutes a part of the control unit that acquires an index value indicating the possibility of collision between the host vehicle and the object, and the brake ECU 70 performs a pre-brake operation. , W / C pressure is generated. However, this is merely an example. For example, the control unit may be configured by one ECU in which the collision avoidance ECU 120 and the brake ECU 70 are integrated, or other ECUs other than the collision avoidance ECU 120 and the brake ECU 70. The control unit may be configured by.

  Moreover, in the said embodiment, although the collision prediction time of collision avoidance control is compared with two of the 1st threshold value and the 2nd threshold value, it is high when the possibility of the collision with the own vehicle and a target object is relatively low. It is only necessary to be able to determine the case, and it may be compared with more than two determination thresholds. For example, in addition to the first and second threshold values, the alarm threshold value can be compared. In this case, for example, a warning is given to the driver when the predicted collision time is less than or equal to the alarm threshold greater than the first threshold, and the precharge operation by the control unit 50 is performed when the collision is less than or equal to the first threshold. A highly responsive automatic pressurizing operation by the unit 60 may be performed. Of course, the alarm threshold value need not be larger than the first threshold value, and may be, for example, less than the first threshold value or more than the second threshold value.

  Moreover, in the said embodiment, although the highly responsive automatic pressurization operation | movement by the pressurization unit 60 is performed after the precharge operation | movement by the control unit 50, the form which does not perform a precharge operation | movement as needed is added. You may do it. For example, when the change gradient of the collision prediction time is steep, or when the collision prediction time suddenly falls below the first threshold due to jumping out or the like, a highly responsive automatic pressurizing operation is immediately performed by the pressurizing unit 60. You may be made to be.

  In the above embodiment, when the predicted collision time becomes the second threshold value or less, the motor 51 of the control unit 50 is stopped and the operations of the pumps 19 and 39 are stopped. Since this may occur, it is preferable to stop the driving of the control unit 50 after the automatic pressurizing operation of the pressurizing unit 60 starts.

  Further, as shown in FIG. 9, the first and second piston portions 65a and 65b used in the first embodiment may be constituted by a piston portion 65 constituted by a tandem piston. The piston portion 65 includes a first piston 651, a second piston 652, and first and second return springs 653 and 654. The first chamber 655 defined by the first piston 651 is connected to the pipeline A, and the second chamber 656 defined by the first piston 651 and the second piston 652 is connected to the pipeline E. The And the connection between the accumulator 61b and the piston part 65 is made only by the pipe line K, and one pressure increasing electromagnetic valve 63 is provided in the pipe line K. Further, the pipe K is connected between the piston portion 65 and the pressure increasing electromagnetic valve 63 and the reservoir 61d by the pipe L, and the pressure regulating electromagnetic valve 64 is provided in the pipe L.

  Thus, also when setting it as the piston part 65 comprised by a tandem piston, the effect similar to the said embodiment can be acquired.

  However, when a tandem piston is used, if one system fails, brake fluid pressure cannot be applied to the other system until one piston in the piston portion 65 reaches the limit movement amount. Regarding the fail-safe property, the configuration of the first embodiment is more advantageous.

  Further, the piston shape in the case of using the piston portion 65 which is a tandem piston can be changed to another form. As shown in FIG. 10, the pipe line K is provided between the first and second pistons 651 and 652. It may be connected and the first and second pistons 651 and 652 may move in opposite directions to transmit the brake fluid pressure to the pipelines A and E.

  DESCRIPTION OF SYMBOLS 1 ... Brake device, 11 ... Brake pedal, 50 ... Control unit, 50a, 50b ... 1st, 2nd piping system, 60 ... Pressurization unit, 61 ... Auxiliary pressure source, 61a ... Hydraulic pump, 61b ... Accumulator, 61c ... Electric motor, 61d ... Reservoir, 61e ... Relief valve, 62a, 62b ... First and second control valves, 63a-63c ... First to third pressure increasing solenoid valves, 64 ... Pressure adjusting solenoid valve, 65 ... Piston part , 65a, 65b ... 1st, 2nd piston part, 66a, 66b ... Pressure sensor, 70 ... Brake ECU, 80 ... ECU for pressurization

Claims (3)

Pressurization that controls the wheel cylinder pressure applied to the wheel cylinder based on the accumulator pressure accumulated in the accumulator that stores the boosted brake fluid pressure, and is connected to a main pipeline that connects the master cylinder and the wheel cylinder. Unit,
A control unit that is provided between the pressurizing unit and the wheel cylinder and controls the wheel cylinder pressure based on a suction and discharge operation of brake fluid by a pump driven by a motor;
A control unit that acquires an index value indicating the possibility of collision between the host vehicle and the object,
Based on the index value, the control unit performs a pre-brake operation for moving a piston provided in the wheel cylinder to a side where a braking force is generated by the control unit when the possibility of the collision is relatively low. And the wheel cylinder pressure is generated by the pressure unit based on the accumulator pressure when the possibility of the collision is relatively high. The pressure unit is
A control valve provided in the main pipe for controlling the flow state of brake fluid in the main pipe;
A hydraulic pump for pumping brake fluid to the accumulator;
An electric motor for driving the hydraulic pump;
A piston portion that is provided closer to the wheel cylinder than the control valve in the main pipeline, and generates the wheel cylinder pressure by applying the accumulator pressure to the wheel cylinder;
A pressure increasing solenoid valve for controlling a flow state of brake fluid in a pipe line connecting the accumulator and the piston portion;
When the possibility of the collision is relatively high, the control unit communicates a pipe line connecting the accumulator and the piston unit with the pressure-increasing electromagnetic valve, and thereby based on the accumulator pressure. The brake device according to claim 1, wherein a wheel cylinder pressure is generated. The pressurizing unit, as the pressure-increasing electromagnetic valve includes a plurality of pressure increasing electromagnetic valves which control the flow state of the brake fluid, arranged in parallel in the tube passage for connecting the accumulator and the piston part,
3. The brake device according to claim 2, wherein when the possibility of a collision is relatively high, the control unit causes any or all of the plurality of pressure-increasing electromagnetic valves to be in communication with each other.

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