JP4962526B2 - Brake device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve high regeneration efficiency and high fuel consumption in a vehicle brake device by suitably using regenerative brake force in all regions from start of stepping of a brake pedal to release of the stepping. <P>SOLUTION: The vehicle brake device includes a pressure adjustment reservoir 50 as a basic hydraulic brake force generation restricting means for restricting generation of basis hydraulic brake force in stepping of the brake pedal 21 so that it is equal to or lower than a predetermined value until the braking manipulation state becomes a predetermined state from a stepping start state where the stepping is started. In the pressure adjustment reservoir 50, a ball valve 51a as a component of a pressure adjustment valve 51 is positioned so as to be located in a position separated in a valve opening direction (upward) by a predetermined distance S1 from a valve closing position (refer to Fig.7) in which the ball valve 51a abuts on a valve seat 51b having a valve hole 51b1 to close the valve hole 51b1 in the stepping start state and to be located in the valve closing position in the predetermined state. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to a vehicle brake device that achieves a target braking force to be applied to a vehicle according to a brake operation state by a hydraulic braking force by a hydraulic brake device and a regenerative braking force by a regenerative brake device.

  2. Description of the Related Art Conventionally, as a vehicle brake device, a device that achieves a target braking force to be applied to a vehicle according to a brake operation state by using a hydraulic braking force by a hydraulic brake device and a regenerative braking force by a regenerative braking device is known. (See Patent Document 1). When the vehicle braking device and the vehicle braking method described in Patent Literature 1 achieve a target vehicle braking force corresponding to a certain pedal depression force, the minimum braking force of the hydraulic brake corresponding to the pedal depression force is calculated from the target vehicle braking force. The difference obtained by subtracting is the assigned braking force, and the difference obtained by subtracting the actual regenerative braking force from this assigned braking force is the distributed braking force of the hydraulic brake. The sum of the minimum braking force and the distributed braking force is the target hydraulic braking force. As a result, the boost ratio of the hydraulic brake is controlled. That is, when the target vehicle braking force is achieved, the braking force of the hydraulic brake always works.

JP 2001-63540 A (page 4-7, FIG. 1-8)

  In the vehicle braking apparatus and the vehicle braking method described in Patent Document 1, when the brake pedal is depressed, in order to achieve the target vehicle braking force, the time from when the brake pedal is depressed until the depression is released The braking force of the hydraulic brake always acts, so there is no room for the regenerative braking force to act on the target vehicle braking force, and the regenerative braking force cannot be used actively. There is a problem that the ratio of the regenerative braking force to the target vehicle braking force is deteriorated correspondingly, and the fuel consumption of the vehicle is deteriorated.

  The present invention has been made to solve the above-described problems. In the vehicle brake device, the regenerative braking force is positively used in a low pedaling force region from when the brake pedal is depressed to a predetermined state. Therefore, it aims at achieving high regenerative efficiency, that is, high fuel efficiency.

In order to solve the above-mentioned problem, the structural feature of the invention according to claim 1 is that a basic hydraulic pressure corresponding to a brake operation state caused by depression of a brake pedal is generated in the master cylinder, and the generated basic hydraulic pressure is A hydraulic brake device for generating a basic hydraulic braking force corresponding to the basic hydraulic pressure on each wheel by directly applying to the wheel cylinder of each wheel connected by an oil path via the master cylinder and a hydraulic control valve. And a regenerative brake device that generates a regenerative braking force on any of the wheels based on the brake operation state, and the hydraulic brake device and the regenerative brake device are operated in cooperation to perform basic hydraulic braking force and regenerative control. In a vehicle brake device that applies a vehicle braking force corresponding to a brake operation state to a vehicle based on power, the brake operation is performed when the brake pedal is depressed. A basic hydraulic braking force generation limiting means for limiting the generation of the basic hydraulic braking force so that the basic hydraulic braking force is not more than a predetermined value until the predetermined state is reached from the depression start state, which is the state at the start of the depression. The hydraulic braking force generation limiting means is provided on the oil path, and generates the basic hydraulic braking force by introducing the basic hydraulic pressure from the master cylinder until the brake operation state reaches the predetermined state from the start of depression. From the hydraulic pressure introduction section that restricts the introduction of the basic hydraulic pressure from the master cylinder and releases the restriction on the generation of the basic hydraulic pressure braking force when the brake operation state is after the predetermined state. It is configured, when the brake operation state is a predetermined state, the the basic hydraulic pressure braking force generating limiting means cancels the limitation of the generation of the basic hydraulic braking force, the regenerative braking system The hydraulic brake device generates the maximum regenerative braking force. The hydraulic brake device stores the brake fluid from the master cylinder or the wheel cylinder, and the brake fluid from the wheel cylinder or the brake fluid stored in the pressure reservoir. And a pump for sucking in and discharging to the master cylinder, and a control fluid formed by driving the pump and controlling the fluid pressure control valve independently of the basic fluid pressure generated in response to the brake operation state By applying pressure to each wheel cylinder, it is possible to generate a control hydraulic braking force on each wheel corresponding to each wheel cylinder, and the hydraulic pressure introduction part is composed of a pressure regulating reservoir, and a pressure regulating valve of the pressure regulating reservoir When the ball valve constituting the valve starts to be depressed, the ball valve contacts the valve seat having the valve hole and closes the valve hole in the valve opening direction. In a predetermined state, the valve is closed so that the valve is closed by a predetermined distance .

According to a second aspect of the present invention, the hydraulic brake device according to the first aspect is characterized in that the hydraulic brake device includes a pressure adjusting reservoir for storing brake fluid from the master cylinder or the wheel cylinder, and a brake fluid or pressure adjusting from the wheel cylinder. And a pump that sucks in the brake fluid stored in the pressure reservoir and discharges it to the master cylinder. The pump drive and fluid pressure are independent of the basic fluid pressure generated in response to the brake operation state. By applying a control hydraulic pressure formed by control of the control valve to each wheel cylinder, it is possible to generate a control hydraulic braking force on each wheel corresponding to each wheel cylinder. When the generation of the basic hydraulic braking force is restricted and the fluctuation of the actual regenerative braking force is detected, the pump is driven and the hydraulic pressure control valve By providing a braking force compensation means for forming a control hydraulic pressure by controlling and generating a control hydraulic braking force based on the control hydraulic pressure on the wheel to compensate for a lack of regenerative braking force due to detected fluctuations is there.

The structural feature of the invention according to claim 3 is that in claim 1 or claim 2 , the brake operation state is a brake pedal stroke sensor for detecting the stroke of the brake pedal or a master cylinder stroke sensor for detecting the stroke of the master cylinder. Is to detect by.

The structural feature of the invention according to claim 4 is the pedal reaction force formation that forms the pedal reaction force of the brake pedal until the brake operation state becomes a predetermined state in any one of claims 1 to 3. It has a means.

In the vehicle brake device having the first structural feature described above, the basic hydraulic braking force generation limiting means is configured so that, when the brake pedal is depressed, the brake operation state is a predetermined state from a depressing start state, which is a state at the time of depressing start. In the meantime, the generation | occurrence | production is restrict | limited so that a basic hydraulic braking force may become below a predetermined value. As a result, when the driver depresses the brake pedal, the basic hydraulic braking force is forcibly limited to a predetermined value or less during the period from the depression start state to the predetermined state. On the other hand, during this period, the regenerative braking device compensates for the shortage of the basic hydraulic braking force with respect to the vehicle braking force by the regenerative braking force by the cooperative operation with the hydraulic braking device for achieving the vehicle braking force corresponding to the brake operation state. . Therefore, in the low pedaling force region from when the brake pedal is depressed to the predetermined state, the regenerative braking force is actively used, and high regenerative efficiency, that is, high fuel consumption can be achieved.
Further, the base hydraulic pressure braking force generation limiting means is provided on the oil path and introduces the base hydraulic pressure from the master cylinder until the brake operation state reaches the predetermined state from the stepping start state to the basic hydraulic pressure control. Hydraulic pressure that restricts the generation of basal hydraulic braking force by restricting the generation of motive power to a predetermined value or less and restricting the introduction of the basic hydraulic pressure from the master cylinder when the brake operation state is after the predetermined state Since it is comprised from the introducing | transducing part, generation | occurrence | production of a basal hydraulic braking force can be restrict | limited with a simple structure.

Further, in the invention according to claim 1 having the structure described above, when the brake operation state is a predetermined state, the basic hydraulic braking force generating restricting means cancels the restriction of the generation of the basic hydraulic braking force, Since the regenerative braking device generates the maximum regenerative braking force, it is possible to ensure as long as possible a region that limits the generation of the basic hydraulic braking force. Therefore, the generation of the basic hydraulic braking force can be delayed as much as possible, and the regenerative braking force can be utilized to the maximum extent without waste over the entire area where the brake pedal is depressed.

Further, in the invention according to claim 1 having the structure described above, the hydraulic brake device includes a pressure control reservoir to reservoir brake fluid from the master cylinder or the wheel cylinder, brake fluid from the wheel cylinder or pressure regulating And a pump that sucks in the brake fluid stored in the reservoir and discharges it to the master cylinder, and controls and controls the pump independently of the basic fluid pressure generated in response to the brake operation state By applying a control hydraulic pressure formed by the control of the valve to each wheel cylinder, it is possible to generate a control hydraulic braking force on each wheel corresponding to the wheel cylinder. The ball valve that constitutes the pressure regulating valve of the pressure regulating reservoir is in a state where the ball valve is in contact with a valve seat having a valve hole when the stepping is started. Since it is positioned so as to be the valve closed position in a predetermined state so that it is a predetermined distance away from the valve closed position in the valve opening direction, the generation of basic hydraulic braking force is limited with a simple configuration can do.

In the invention according to claim 2 configured as described above, in claim 1 , the hydraulic brake device includes a pressure adjusting reservoir for storing brake fluid from the master cylinder or the wheel cylinder, and brake fluid from the wheel cylinder. Or a pump that sucks the brake fluid stored in the pressure-regulating reservoir and discharges it to the master cylinder, and drives the pump independently of the basic fluid pressure generated in response to the brake operation state. Basic hydraulic braking force generation limiting means configured to generate a control hydraulic braking force to each wheel corresponding to each wheel cylinder by applying a control hydraulic pressure formed by the control of the hydraulic control valve to each wheel cylinder. When the generation of the basic hydraulic braking force is restricted at, and the fluctuation of the actual regenerative braking force is detected, the pump is driven A braking force compensation that forms a control hydraulic pressure by controlling the hydraulic pressure control valve and generates a control hydraulic braking force based on the control hydraulic pressure on the wheel to compensate for the lack of regenerative braking force due to detected fluctuations Since the means is provided, the braking force required by the driver can be stably applied regardless of the change in the regenerative braking force.

In the invention according to claim 3 configured as described above, in claim 1 or claim 2 , the brake operation state is a brake pedal stroke sensor that detects the stroke of the brake pedal, or a master cylinder that detects the stroke of the master cylinder. Since it detects by a stroke sensor, a brake operation state can be reliably and directly detected by these stroke sensors.

In the invention according to claim 4 configured as described above, the pedal reaction that forms the pedal reaction force of the brake pedal until the brake operation state becomes a predetermined state in any one of claims 1 to 3. Since the force forming means is provided, the driver can feel a good pedal feeling until the brake pedal is depressed and the brake operation state becomes a predetermined state.

1 is a schematic diagram showing a first reference form to which a vehicle brake device according to the present invention is applied. FIG. It is a figure which shows the state before brake depression of the basic | foundation hydraulic-pressure braking force generator shown in FIG. It is a figure which shows the state in the time of brake depression of the basic | foundation hydraulic-pressure braking force generator shown in FIG. It is a schematic diagram which shows the outline | summary of the brake actuator of the hydraulic brake apparatus shown in FIG. It is a correlation diagram of the brake operation force and braking force by the 1st reference form to which the brake device for vehicles by the present invention is applied. It is sectional drawing which shows the state before brake depression of the pressure regulation reservoir shown in FIG. FIG. 5 is a cross-sectional view showing a state where the brake of the pressure regulating reservoir shown in FIG. 4 is being depressed. 2 is a flowchart of a control program executed by a brake ECU shown in FIG. It is sectional drawing which shows the state before brake depression of the pressure regulation reservoir in 1st Embodiment to which the brake device for vehicles by this invention is applied. It is a correlation diagram of brake operation force and braking force by a 1st embodiment to which a brake device for vehicles by the present invention is applied. It is sectional drawing which shows the state before brake depression of the operating rod in the 2nd reference form to which the brake device for vehicles by this invention is applied. It is a figure which shows the modification of the pedal reaction force means shown in FIG.

1) The first reference embodiment will be described below first reference embodiment according to the vehicle brake device according to the present invention in a hybrid vehicle with reference to the accompanying drawings. FIG. 1 is a schematic diagram showing a configuration of the hybrid vehicle, and FIG. 2 is a schematic diagram showing a configuration of a basic hydraulic braking force generating device of a vehicle brake device. As shown in FIG. 1, the hybrid vehicle is a vehicle that drives driving wheels, for example, left and right front wheels FR and FL by a hybrid system. The hybrid system is a power train that uses a combination of two types of power sources, the engine 11 and the motor 12. In the case of the first reference embodiment , the parallel hybrid system is a system in which wheels are directly driven by both the engine 11 and the motor 12. In addition to this, there is a serial hybrid system, in which wheels are driven by the motor 12, and the engine 11 acts as a power supply source to the motor 12.

A hybrid vehicle equipped with this parallel hybrid system includes an engine 11 and a motor 12. The driving force of the engine 11 is transmitted to the driving wheels (the left and right front wheels FR and FL in the first reference embodiment ) via the power split mechanism 13 and the power transmission mechanism 14. The force is transmitted to the drive wheels via the power transmission mechanism 14. The power split mechanism 13 appropriately splits the driving force of the engine 11 into a vehicle driving force and a generator driving force. The power transmission mechanism 14 appropriately integrates the driving forces of the engine 11 and the motor 12 according to traveling conditions and transmits them to the driving wheels. The power transmission mechanism 14 adjusts the driving force ratio transmitted between the engine 11 and the motor 12 between 0: 100 and 100: 0. The power transmission mechanism 14 has a speed change function.

  The motor 12 assists the output of the engine 11 and increases the driving force. On the other hand, the motor 12 generates power when the vehicle is braked and charges the battery 17. The generator 15 generates power based on the output of the engine 11 and has a starter function when starting the engine. The motor 12 and the generator 15 are electrically connected to the inverter 16, respectively. The inverter 16 is electrically connected to a battery 17 serving as a DC power source. The inverter 16 converts the AC voltage input from the motor 12 and the generator 15 into a DC voltage and supplies it to the battery 17. A DC voltage is converted into an AC voltage and output to the motor 12 and the generator 15.

In the first reference embodiment , a regenerative brake device A is constituted by the motor 12, the inverter 16 and the battery 17, and the regenerative brake device A is detected by a pedal stroke sensor 21a (or a pressure sensor P). The regenerative braking force based on the brake operation state (described later) is set to any one of the wheels FR, FL, RR, RL (in the first reference embodiment , left and right front wheels FR, FL).

  The engine 11 is controlled by an engine ECU (electronic control unit) 18. The engine ECU 18 outputs an opening degree command to an electronic control throttle according to an engine output request value from a hybrid ECU (electronic control unit) 19 described later. Adjust the rotation speed. The hybrid ECU 19 is connected so that the inverters 16 can communicate with each other. The hybrid ECU 19 derives necessary engine output, electric motor torque, and generator torque from the accelerator opening and shift position (calculated from a shift position signal input from a shift position sensor not shown), and the derived engine output request value Is transmitted to the engine ECU 18 to control the driving force of the engine 11, and the motor 12 and the generator 15 are controlled through the inverter 16 in accordance with the derived electric motor torque request value and generator torque request value. The hybrid ECU 19 is connected to a battery 17 and monitors the charge state, the charge current, and the like of the battery 17. Further, the hybrid ECU 19 is also connected to an accelerator opening sensor (not shown) that is assembled to an accelerator pedal (not shown) and detects the accelerator opening of the vehicle, and inputs an accelerator opening signal from the accelerator opening sensor. ing.

  Further, the hybrid vehicle includes a hydraulic brake device B that applies a hydraulic braking force directly to each wheel FR, FL, RR, RL to brake the vehicle. As shown in FIG. 4, the hydraulic brake device B generates a basic hydraulic pressure corresponding to a brake operation state caused by depression of the brake pedal 21 in the master cylinder 23, and the generated basic hydraulic pressure is transmitted to the master cylinder 23. By directly applying the hydraulic pressure control valves 31, 41 to the wheel cylinders WC1, WC2, WC3, WC4 of the wheels FR, FL, RR, RL connected by the oil paths Lf, Lr respectively interposed, the respective wheels FR. , FL, RR, and RL generate a basic hydraulic braking force corresponding to the basic hydraulic pressure, and drive and hydraulic pressure control of the pumps 37 and 47 independently of the basic hydraulic pressure generated corresponding to the brake operation state The control hydraulic pressure formed by the control of the valves 31, 41 is applied to the wheel cylinders WC1, WC2, WC3, WC4 of each wheel FR, FL, RR, RL. By those generated configured to be able to control hydraulic braking force on each wheel FR, FL, RR, RL.

  This hydraulic brake device B is a booster 22 that is a booster that boosts (increases) the brake operating force generated by the depression of the brake pedal 21 by applying the intake negative pressure of the engine 11 to the diaphragm. And the brake fluid (oil) of the hydraulic pressure (hydraulic pressure) that is the basic hydraulic pressure corresponding to the brake operating force (that is, the operating state of the brake pedal 21) boosted by the negative pressure booster 22 is generated to generate wheel cylinders WC1 to WC1. A master cylinder 23 to be supplied to the WC 4, a reservoir tank 24 for storing brake fluid and replenishing the brake fluid to the master cylinder 23, and provided between the master cylinder 23 and the wheel cylinders WC 1 to WC 4 to control hydraulic pressure. A brake actuator (control hydraulic pressure braking force generator) 25 to be formed is provided. A basic hydraulic braking force generator is constituted by the brake pedal 21, the negative pressure booster 22, the master cylinder 23, and the reservoir tank 24.

  As shown in FIGS. 2 and 3, the brake pedal 21 is connected to a negative pressure booster 22 via an operating rod 26, and the negative pressure booster 22 is connected to a master cylinder 23 via a push rod 27. The brake operating force applied to 21 is input to the negative pressure booster 22 via the operating rod 26, boosted, and input to the master cylinder 23 via the push rod 27.

  The brake pedal 21 is provided with a pedal stroke sensor 21 a that detects a brake pedal stroke that is a brake operation state by depression of the brake pedal 21. The pedal stroke sensor 21a is connected to the brake ECU 60, and a detection signal is transmitted to the brake ECU 60. Further, the brake pedal 21 is provided with a reaction force spring 21b which is a pedal reaction force forming means for forming a pedal reaction force of the brake pedal 21 until the brake operation state becomes a predetermined state (described later). The reaction force spring 21b is connected at one end to a bracket 10a fixed to the vehicle body of the vehicle, and is in a depressing release direction that is opposite to the depressing direction of the brake pedal 21 (before the brake pedal 21 is depressed). The direction is returned to the original position). The urging force of the reaction force spring 21b is preferably set in consideration of the inner diameter of the housing 23a of the master cylinder 23, the boost ratio, and the like.

  The negative pressure booster 22 is generally well known, and a negative pressure intake port 22a communicates with an intake manifold of the engine 11 and uses the negative pressure of the intake manifold as a boost source.

  As shown in FIGS. 2 and 3, the master cylinder 23 that is a basic hydraulic braking force generating means is a tandem master cylinder, and has a housing 23a formed in a bottomed cylindrical shape, First and second pistons 23b, 23c accommodated side by side in a slidable manner, and a first spring disposed in a first hydraulic pressure chamber 23d formed between the first piston 23b and the second piston 23c 23e, and a second spring 23g disposed in a second hydraulic chamber 23f formed between the second piston 23c and the closed end of the housing 23a. As a result, the second piston 23c is urged toward the opening end side (first piston 23b side) by the second spring 23g, and the first piston 23b is urged toward the opening end side by the first spring 23e. One end (open end side end) of 23 b is pressed against and abutted against the tip of the push rod 27.

  The housing 23a of the master cylinder 23 includes a first port 23h for communicating the first hydraulic chamber 23d and the reservoir tank 24, and a second port 23i for communicating the second hydraulic chamber 23f and the reservoir tank 24. And are provided. The first port 23h is a first piston 23b in a first position (return position: illustrated state in FIG. 2) in which the driver's foot is separated from the brake pedal 21, that is, the brake pedal 21 is not depressed. Is disposed at a second position corresponding to a predetermined state separated by a predetermined distance s in the pressure increasing direction of the first piston 23b (the direction toward the closed end: leftward in FIG. 2) from the closed end that closes the same port 23h. ing. Similarly to the first piston 23b, the second port 23i has a closed end that closes the second port 23i of the second piston 23c in the first position (return position: shown in FIG. 2). (That is, a position immediately before the closed end of the second piston 23c begins to close the opening of the second port 23i).

  The predetermined state is a brake operation state in which the generation restriction of the base hydraulic pressure braking force is released and the base hydraulic pressure braking force starts increasing the pressure corresponding to the brake operation state. Further, the predetermined distance s is desirably set so that the regenerative braking device A generates the maximum regenerative braking force when the brake operation state is the predetermined state. Thereby, when the brake operation state becomes a predetermined state, the master cylinder 23 releases the restriction on the generation of the basic hydraulic braking force, and the regenerative braking device A generates the maximum regenerative braking force.

  Further, the housing 23a of the master cylinder 23 constitutes a third port 23j for communicating the first hydraulic pressure chamber 23d and the oil path Lr constituting the rear wheel system, and a second hydraulic pressure chamber 23f and the front wheel system. A fourth port 23k for communicating with the oil path Lf is provided. As shown in FIG. 4, the oil path Lr communicates the first hydraulic chamber 23d with the wheel cylinders WC3, WC4 of the left and right rear wheels RR, RL, and the oil path Lf is the second hydraulic chamber. 23f communicates with the wheel cylinders WC1 and WC2 of the left and right front wheels FR and FL, respectively.

  Each wheel cylinder WC1, WC2, WC3, WC4 is supplied with hydraulic pressure (basic hydraulic pressure, control hydraulic pressure) from the master cylinder 23 via oil paths Lf, Lr. Each brake means BK1, BK2, BK3, BK4 provided corresponding to WC4 is operated to apply a hydraulic braking force (basic hydraulic braking force, braking hydraulic braking force) to each wheel FR, FL, RR, RL. . Each of the brake means BK1, BK2, BK3, BK4 includes a disc brake, a drum brake, and the like, and friction members such as a brake pad and a brake shoe regulate the rotation of the disc rotor, the brake drum, etc. integrated with the wheel. ing.

  The operation of the master cylinder 23 will be described with reference to FIGS. As shown in FIG. 2, in the state where the brake pedal 21 is not depressed, the operating rod 26 and the push rod 27 are not pushed and thus are not moved, and therefore the first piston 23b and the second piston 23c are not pushed. No basic hydraulic pressure is generated in the first and second hydraulic chambers 23d and 23f.

  However, when the brake pedal 21 (see FIG. 2), which is not depressed, is depressed by the driver, the operating rod 26 and the push rod 27 are pushed, thereby pushing the first piston 23b. At this time, the first port 23h is not closed by the closed end of the first piston 23b until the first piston 23b is pushed by the push rod 27 and moved in the left direction (pressure increasing direction) by a predetermined distance s or more. Since the brake fluid in the first hydraulic pressure chamber 23d flows out to the reservoir tank 24 through the first port 23h, no basic hydraulic pressure is generated in the first hydraulic pressure chamber 23d. In addition, the first spring 23e is pushed and compressed by the movement of the first piston 23b, but no basic hydraulic pressure is generated in the first hydraulic pressure chamber 23d. The second port 23i does not start to be closed by the closed end of the second piston 23c, so that no basic hydraulic pressure is generated in the second hydraulic pressure chamber 23f. .

  When the first piston 23b moves in the left direction of the drawing by a value obtained by adding the diameter of the first port 23h to the predetermined distance s, the first port 23h is closed by the closed end of the first piston 23b, and the first hydraulic pressure chamber 23d is closed. Since the brake fluid cannot flow out to the reservoir tank 24 through the first port 23h and the first hydraulic pressure chamber 23d is in a sealed state, formation of the basic hydraulic pressure is started in the first hydraulic pressure chamber 23d. Further, the second piston 23c is pushed leftward in the drawing by the basic hydraulic pressure generated in the first hydraulic pressure chamber 23d and instantaneously closes the second port 23i by the closed end, so that the second hydraulic pressure chamber 23f The brake fluid cannot flow out to the reservoir tank 24 through the second port 23i, and the second hydraulic chamber 23f is hermetically sealed, so that the formation of the basic hydraulic pressure is also started in the second hydraulic chamber 23f. .

  When the brake pedal 21 is further depressed from the state in which the formation of the basic hydraulic pressure is started in the first and second hydraulic pressure chambers 23d and 23f in this way, the depression state shown in FIG. 3 to the depressed state shown in FIG. 3 (after the basic hydraulic pressure formation start state), basic hydraulic pressure corresponding to the brake operation state is generated in the first and second hydraulic pressure chambers 23d and 23f. ing. The basic hydraulic pressures generated in the first and second hydraulic pressure chambers 23d and 23f are the same. When the foot is released from the brake pedal 21 in the depressed state shown in FIG. 3, the first and second pistons 23b, 23c are respectively biased by the first and second springs 23e, 23g and the oil paths Lr, Lf. The pressure returns to the original position (first position).

  The basic hydraulic braking force by the basic hydraulic pressure formed by the master cylinder 23 described above is shown by a solid line in FIG. That is, when the brake pedal stroke is located between the depression start position and the position where the first port 23h is closed, the basic hydraulic pressure generated in the first and second hydraulic chambers 23d and 23f of the master cylinder 23 is 0. Therefore, the generation of the basic hydraulic braking force is also limited to zero. When the brake pedal stroke is located at a position beyond the position where the first port 23h is closed, the above-described restriction on the basic hydraulic pressure is released, and the brake pedal stroke is generated in the first and second hydraulic pressure chambers 23d and 23f. Since the basic hydraulic pressure corresponds to the brake pedal stroke, the basic hydraulic pressure braking force also corresponds to the brake pedal stroke. The state where the brake pedal stroke is located at the position where the first port 23h is closed is the predetermined state, and the brake operation state in which the basic hydraulic braking force starts to increase corresponding to the brake pedal stroke. Therefore, as shown by the solid line in FIG. 5, by applying the basic hydraulic pressure directly to the wheel cylinders WC1, WC2, WC3, WC4, the foundation corresponding to the basic hydraulic pressure is applied to the wheels FR, FL, RR, RL. A hydraulic braking force can be generated.

  Next, the brake actuator 25 will be described in detail with reference to FIG. The brake actuator 25 is generally well known, and includes hydraulic pressure control valves 31, 41, pressure increase control valves 32, 33, 42, 43 and pressure reduction control valves 35, 36 constituting an ABS control valve. , 45, 46, pressure regulating reservoirs 34, 44, pumps 37, 47, motor M and the like are packaged in one case.

  First, the configuration of the front wheel system of the brake actuator 25 will be described. The oil path Lf is provided with a hydraulic pressure control valve 31 composed of a differential pressure control valve. The hydraulic pressure control valve 31 is controlled to be switched between a communication state and a differential pressure state by the brake ECU 60. Although the hydraulic pressure control valve 31 is normally in a communication state, by setting the differential pressure state, the oil path Lf2 on the wheel cylinders WC1 and WC2 side is higher than the oil path Lf1 on the master cylinder 23 side by a predetermined differential pressure. Can be held in. This differential pressure is regulated by the brake ECU 60 according to the control current.

  The oil path Lf2 is branched into two, one of which is provided with a pressure increase control valve 32 that controls the increase of the brake fluid pressure to the wheel cylinder WC1 in the ABS control pressure increase mode, and the other is the ABS. A pressure increase control valve 33 is provided for controlling an increase in brake fluid pressure to the wheel cylinder WC2 in the control pressure increase mode. These pressure increase control valves 32 and 33 are configured as two-position valves that can control the communication / blocking state by the brake ECU 60. When these pressure increase control valves 32 and 33 are controlled to communicate, the basic hydraulic pressure of the master cylinder 23 or / and the control hydraulic pressure formed by driving the pump 37 and controlling the hydraulic control valve 31 are controlled. It can be added to each wheel cylinder WC1, WC2. The pressure increase control valves 32 and 33 can execute ABS control together with the pressure reduction control valves 35 and 36 and the pump 37.

  Note that, during normal braking in which ABS control is not being executed, these pressure increase control valves 32 and 33 are always controlled to communicate. Further, the pressure increase control valves 32 and 33 are respectively provided with safety valves 32a and 33a in parallel. When the brake pedal 21 is released during the ABS control, the brake fluid from the wheel cylinders WC1 and WC2 is accompanied accordingly. Is returned to the reservoir tank 24.

  The oil path Lf2 between the pressure increase control valves 32 and 33 and the wheel cylinders WC1 and WC2 is communicated with the reservoir hole 50c of the pressure regulating reservoir 34 through the oil path Lf3. The oil path Lf3 is provided with pressure reduction control valves 35 and 36 that can control the communication / blocking state by the brake ECU 60, respectively. These pressure reduction control valves 35 and 36 are always cut off in the normal brake state (when the ABS is not in operation), and are appropriately connected to release brake fluid to the pressure regulating reservoir 34 through the oil path Lf3, whereby the wheel cylinder WC1. , WC2 is configured to control the brake fluid pressure and prevent the wheels from becoming locked.

  Further, a pump 37 is disposed together with a safety valve 37a in an oil path Lf4 connecting the oil path Lf2 between the hydraulic pressure control valve 31 and the pressure increase control valves 32 and 33 and the reservoir hole 50c of the pressure regulating reservoir 34. . An oil path Lf5 is provided so as to connect the reservoir hole 50b of the pressure regulating reservoir 34 to the master cylinder 23 via the oil path Lf1. The pump 37 is driven by the motor M according to a command from the brake ECU 60. In the ABS control pressure-reduction mode, the pump 37 sucks brake fluid stored in the wheel cylinders WC1 and WC2 or the brake fluid stored in the pressure-regulating reservoir 34 through the fluid pressure control valve 31 that is in communication with the master. It is returned to the cylinder 23. In addition, the pump 37 applies a hydraulic control valve 31 that is switched to a differential pressure state when forming a control hydraulic pressure for stably controlling the posture of the vehicle such as VSC control, traction control, and brake assist. In order to generate the differential pressure, the brake fluid in the master cylinder 23 is sucked through the oil passages Lf1 and Lf5 and the pressure regulating reservoir 34, and then through the oil passages Lf4 and Lf2 and the pressure increase control valves 32 and 33 in communication. Control hydraulic pressure is applied by discharging to each wheel cylinder WC1, WC2. An accumulator 38 is disposed on the upstream side of the pump 37 in the oil path Lf4 in order to reduce the pulsation of the brake fluid discharged from the pump 37.

  The oil path Lf1 is provided with a pressure sensor P that detects a master cylinder pressure that is a brake fluid pressure in the master cylinder 23, and this detection signal is transmitted to the brake ECU 60. The pressure sensor P may be provided in the oil path Lr1.

  Further, the rear wheel system of the brake actuator 25 has the same configuration as that of the front wheel system described above, and the oil path Lr configuring the rear wheel system is configured by oil paths Lr1 to Lr5 in the same manner as the oil path Lf. The oil path Lr includes a fluid pressure control valve 41 similar to the fluid pressure control valve 31 and a pressure regulating reservoir 44 similar to the pressure regulating reservoir 34. The branched oil paths Lr2 and Lr2 communicating with the wheel cylinders WC3 and WC4 are provided with pressure increase control valves 42 and 43 similar to the pressure increase control valves 32 and 33, and the pressure reduction control valves 35 and 36 are provided in the oil path Lr3. Similar pressure reduction control valves 45 and 46 are provided. The oil path Lr4 includes a pump 47, a safety valve 47a, and an accumulator 48 similar to the pump 37, the safety valve 37a, and the accumulator 38. The pressure increase control valves 42 and 43 are provided with safety valves 42a and 43a in parallel with the safety valves 32a and 33a, respectively.

  Thereby, the control hydraulic pressure formed by the drive of the pumps 37 and 47 and the control of the hydraulic pressure control valves 31 and 41 is applied to the wheel cylinders WC1, WC2, WC3 and WC4 of the respective wheels FR, FL, RR and RL. Thus, the control hydraulic braking force can be generated in each of the wheels FR, FL, RR, RL.

  Further, the pressure regulating reservoirs 34 and 44 will be described with reference to FIGS. 6 and 7. The pressure adjusting reservoir 50 constituting the pressure regulating reservoirs 34 and 44 is built in a housing 25a constituting the brake actuator 25, as shown in FIG. A stepped hole 50a including a small diameter hole 50a1 and a large diameter hole 50a2 is formed in the housing 25a. One end (upper end) of the small-diameter hole 50a1 is formed with a reservoir hole 50b that communicates with one end of an oil passage Lf5 (or Lr5) that communicates with the master cylinder 23, and the other end (lower end) of the small-diameter hole 50a1 includes A pressure regulating valve 51 is provided. The pressure regulating valve 51 includes a ball valve 51a as a valve body and a valve seat 51b having a valve hole 51b1. The ball valve 51a is pressed against the valve seat 51b by the urging force of the spring 52 to close the valve hole 51b1 (see FIG. 7).

  One end (upper end) of the large-diameter hole 50a2 is formed with a reservoir hole 50c that communicates with one end of the oil path Lf3 (or Lr3) that communicates with the suction port of the pump 37 (or pump 47). A closing member 53 for closing the opening is fixed to the other end of the cover. The piston 54 is accommodated in the large-diameter hole 50a2 so as to be liquid-tight and slidable. A pin 55 is integrally attached to one end surface (upper end surface) of the piston 54 so as to reciprocate in the valve hole 51b1 of the valve seat 51b and to move the protruding tip abutting on the ball valve 51a and moving up and down. The piston 54 is pushed to one end side (upward) by an urging force of a spring 56 (set to be larger than the urging force of the spring 52) disposed between the piston 54 and the closing member 53, and has a large diameter. It abuts on the upper end surface of the hole 50a2 (see FIG. 6). At this time, since the tip of the pin 55 is set so as to protrude from the valve seat 51b by a predetermined amount S0, the ball valve 51a can be stroked by a predetermined amount S0 with respect to the seating surface of the valve seat 51b. . A reservoir chamber 50d for storing brake fluid is formed between the pressure regulating valve 51 and the piston 54 in the stepped hole 50a.

  As described above, the pressure adjusting reservoir 50 has the tip of the pin 55 connected to the ball valve when the brake fluid stored in the reservoir chamber 50d is less than a predetermined amount (an amount corresponding to a stroke of the predetermined amount S0). When the valve hole 51b1 is opened by pushing 51a and the reservoir chamber 50d is filled with a predetermined amount of brake fluid, the valve hole 51b1 is closed by the ball valve 51a (see FIG. 7). The operation of the pressure regulating reservoir 50 will be described in detail.

  First, when the brake pedal 21 is not depressed and the master cylinder pressure (basic hydraulic pressure) is not formed, and the brake actuator 25 is not operated and the braking hydraulic pressure is not formed, the pressure regulating reservoir 50 The piston 54 has its upper end surface in contact with the upper end surface of the large-diameter hole 50a2 by the biasing force of the spring 56, and the ball valve 51a is positioned above the seat surface of the valve seat 51b by a predetermined amount S0. (See FIG. 6).

  During normal braking without driving the pumps 37 and 47, the differential pressure control valves 31, 41 and the pressure increase control valves 32, 33, 42, 43 are in communication, and the pressure reduction control valves 35, 36, 45, 46 are It is in a cut-off state. For this reason, the master cylinder pressure generated by the depression of the brake pedal 21 is directly applied to the wheel cylinders WC1, WC2, WC3, and WC4. At this time, the brake fluid from the master cylinder flows into the reservoir chamber 50d through the oil passages Lf5, Lr5 and the respective reservoir holes 50b, through the valve hole 51b1. However, when the piston 54 is pushed down by a predetermined amount S0 against the urging force of the spring 56 as the inflow amount increases, the ball valve 51a supported by the pin 55 is also moved and pressed against the valve seat 51b. The hole 51b1 is closed (see FIG. 7). As a result, the master cylinder pressure is not applied to the suction ports of the pumps 37 and 47. Note that the master cylinder pressure (basic hydraulic pressure) corresponding to the brake operation state is directly applied to the wheel cylinders WC1, WC2, WC3, and WC4 only after the pressure regulating valve 51 is closed. Since the brake fluid from the master cylinder 23 flows into the reservoir chamber 50d through the pressure regulating valve 51, the basic fluid pressure corresponding to the brake operation state is not applied to each wheel cylinder WC1, WC2, WC3, WC4. However, the predetermined amount S0 is extremely small and does not give a big problem to the generation of the basic hydraulic pressure.

  For example, when the brake fluid pressure (control fluid pressure) is generated so as to assist the depression of the brake pedal 21, the differential pressure control valves 31, 41 are brought into a differential pressure state. As a result, the brake fluid from the oil paths Lf1 and Lr1 flows into the reservoir chamber 50d through the oil paths Lf5 and Lr5 and the respective reservoir holes 50b. Then, the brake fluid in the reservoir chamber 50d is sucked and discharged by the pumps 37 and 47, the brake fluid is supplied to the oil paths Lf2 and Lr2, and the wheel cylinder pressure is controlled by the differential pressure control valves 31 and 41 which are brought into the differential pressure state. Is maintained higher than the master cylinder pressure. When a predetermined amount of brake fluid is stored in the reservoir chamber 50d without keeping up with the amount of brake fluid flowing into the reservoir chamber 50d (including reduction of wheel cylinder pressure by ABS control). The ball valve 51a is seated on the valve seat 51b and shuts off the oil paths Lf1 and Lr1 (master cylinder 23) and the suction sides of the pumps 37 and 47. When the brake fluid in the reservoir chamber 50d is sucked by the pumps 37 and 47, the amount of brake fluid in the reservoir chamber 50d decreases, and the pin 55 pushes up the ball valve 51a to move from the master cylinder side to the reservoir chamber 50d. Brake fluid is supplied.

  The vehicle brake device includes a pedal stroke sensor 21a, wheel speed sensors Sfl, Sfr, Srl, Srr that detect wheel speeds of the wheels FL, FR, RL, and RR, pressure sensors P, control valves 31, 32, 33, 35, 36, 41, 42, 43, 45, 46, and a brake ECU (electronic control unit) 60 connected to the motor M are provided. The brake ECU 60 switches and controls the states of the control valves 31, 32, 33, 35, 36, 41, 42, 43, 45, 46 of the hydraulic brake device B based on the detection by these sensors and the state of the shift switch. Alternatively, the control hydraulic pressure applied to the wheel cylinders WC1 to WC4, that is, the control hydraulic braking force applied to each wheel FL, FR, RL, RR is controlled by controlling the energization current.

  Furthermore, the brake ECU 60 is connected to the hybrid ECU 19 so as to be communicable with each other, and performs cooperative control of the regenerative brake and the hydraulic brake performed by the motor 12 so that the total braking force of the vehicle is equivalent to that of the vehicle having only the hydraulic brake. . Specifically, in response to the driver's braking request, that is, the braking operation state, the brake ECU 60 provides the hybrid ECU 19 with a regeneration request value that is a share of the regenerative braking device out of the total braking force. Output as braking force. The hybrid ECU 19 derives an actual regeneration execution value that is actually acted as a regeneration brake in consideration of the vehicle speed, the battery charging state, and the like based on the input regeneration request value (target regeneration braking force), and the regeneration corresponding to the actual regeneration execution value. The motor 12 is controlled via the inverter 16 so as to generate the braking force, and the derived actual regeneration execution value is output to the brake ECU 60.

  Further, the brake ECU 60 applies a basic hydraulic braking force applied to the wheels FL, FR, RL, RR by the brake means BK1, BK2, BK3, BK4 when the basic hydraulic pressure is supplied to the wheel cylinders WC1, WC2, WC3, WC4. Is stored in advance in a memory as a map, table or arithmetic expression. In addition, the brake ECU 60 stores the target regenerative braking force applied to the wheels FL, FR, RL, RR according to the brake operation state, which is the stroke (or master cylinder pressure) of the brake pedal, in the memory as a map, table, or arithmetic expression. Pre-stored. Further, the brake ECU 60 stores a cooperative control program (vehicle brake control program) shown in FIG.

  Next, the operation of the vehicle brake device configured as described above will be described with reference to the flowchart of FIG. For example, when the ignition switch (not shown) of the vehicle is in an on state, the brake ECU 60 executes a program corresponding to the above flowchart every predetermined short time. The brake ECU 60 inputs a pedal stroke which is an operation state of the brake pedal 21 from the pedal stroke sensor 21a (step 102), and calculates a target regenerative braking force corresponding to the input pedal stroke (step 104). At this time, the brake ECU 60 uses a map, a table, or an arithmetic expression indicating the relationship between the pedal stroke stored in advance, that is, the brake operation state and the target regenerative braking force applied to the wheels FL, FR, RL, RR.

  If the target regenerative braking force is greater than 0, the target regenerative braking force calculated in step 104 is output to the hybrid ECU 19 and the brake actuator 25 is not controlled (steps 106 and 108). Accordingly, when the brake pedal 21 is depressed, the hydraulic brake device B applies only the basic hydraulic braking force (static pressure brake) to the wheels FL, FR, RL, RRf, and 23r as in the case described above. Further, the hybrid ECU 19 inputs a regenerative request value indicating the target regenerative braking force, and controls the motor 12 via the inverter 16 so as to generate the regenerative braking force in consideration of the vehicle speed, the battery charge state, etc. based on the value. While controlling, the actual regeneration execution value is output to brake ECU60. Therefore, when the brake operation is performed and the target regenerative braking force is greater than 0, the wheel FL, FR, RL, RR is applied with the regenerative braking force added to the basic hydraulic braking force. Thus, the regenerative cooperative control is executed. At this time, the basic hydraulic braking force and the regenerative braking force depend on the brake operation force, and an example thereof is shown in FIG. FIG. 5 shows the correlation between the brake operation force during regenerative cooperative control and the braking force indicating the sum of the basic hydraulic braking force and the regenerative braking force.

That is, according to the master cylinder 23 (basic hydraulic braking force generation limiting means) according to the first reference embodiment , when the brake pedal 21 is depressed, the brake operation state is a predetermined state from the depression start state which is the state at the depression start point. Until the basic hydraulic braking force is reduced to a predetermined value or less. As a result, when the driver depresses the brake pedal 21, the basic hydraulic braking force is forcibly limited to a predetermined value or less during the period from the depression start state to the predetermined state, as shown in FIG. Only power is applied according to the brake operation state. Further, when the brake operation state becomes a predetermined state, the restriction on the generation of the basic hydraulic braking force is released, and the regenerative braking device A generates the maximum regenerative braking force, so that only the maximum regenerative braking force is applied. The Further, when the brake operation state is depressed from the predetermined state, the release of the restriction on the generation of the basic hydraulic braking force is maintained, and the hydraulic brake device B and the regenerative brake device A are operated cooperatively. A vehicle braking force corresponding to the brake operation state is applied based on the hydraulic braking force and the regenerative braking force (basically, the maximum regenerative braking force).

  The brake ECU 60 detects fluctuations in the regenerative braking force actually generated by the regenerative braking device A (steps 110 to 114). Specifically, the brake ECU 60 performs actual regenerative execution indicating the actual regenerative braking force that the regenerative braking device A actually applied to the wheels FL, FR, RL, and RR with respect to the target regenerative braking force calculated in step 104. A value is input (step 110), the difference between the target regenerative braking force calculated in step 104 and the actual regenerative braking force input in step 110 is calculated (step 112), and the calculated difference is a predetermined value. If it is greater than a, it is detected that the regenerative braking force has fluctuated (step 114).

  When the brake ECU 60 detects a change in the regenerative braking force, the brake ECU 60 determines YES in step 114, drives the pumps 37 and 47 of the hydraulic brake device B, and controls the hydraulic control valves 31 and 41. Compensating for insufficient braking force due to fluctuations in the regenerative braking force detected as described above by forming a control hydraulic pressure and applying a control hydraulic braking force based on the control hydraulic pressure to the wheels FL, FR, RL, and RR (Step 116). Specifically, the brake ECU 60 determines the hydraulic pressure corresponding to the difference between the target power calculated in step 104 and the actual regenerative braking force input in step 110, that is, the difference calculated in step 112. The control hydraulic pressure is controlled so that The brake ECU 60 activates the motor M to drive the pumps 37 and 47, so that the hydraulic pressure of the brake fluid supplied from the pumps 37 and 47 to the wheel cylinders WC1, WC2, WC3 and WC4 becomes the control hydraulic pressure. An electric current is applied to the linear solenoids of the pressure control valves 31 and 41. At this time, the linear solenoid 33 is more preferably feedback controlled so that the hydraulic pressures of the wheel cylinders WC1, WC2, WC3, and WC4 detected by the hydraulic pressure sensor 40 become the control hydraulic pressure. On the other hand, if the brake ECU 60 does not detect a change in the regenerative braking force, the brake ECU 60 determines NO in step 114 and stops the control of the brake actuator 25 (step 118).

As is clear from the above description, according to the first reference embodiment, when the master cylinder 23 as the basic hydraulic braking force generation limiting means is depressed, the brake operation state (pedal stroke) is depressed. The generation is limited so that the basic hydraulic braking force is less than or equal to a predetermined value (0) from the start step state (first position) to the predetermined state (second position). Thus, when the driver depresses the brake pedal 21, the basic hydraulic braking force is forcibly limited to a predetermined value or less during the period from the depression start state to the predetermined state. On the other hand, during this period, the regenerative braking device A uses the regenerative braking force to compensate for the shortage of the basic hydraulic braking force with respect to the vehicle braking force by the cooperative operation with the hydraulic braking device B for achieving the vehicle braking force corresponding to the brake operation state. Make up with. Therefore, in the low pedaling force region from when the brake pedal 21 starts to be depressed to a predetermined state, the regenerative braking force is actively used, and high regenerative efficiency, that is, high fuel consumption can be achieved.

  Further, when the brake operation state (pedal stroke of the brake pedal 21) becomes a predetermined state (a state where the first port 23h of the master cylinder 23 is closed), the master cylinder 23 (basic hydraulic braking force generation limiting means) is While releasing the restriction | limiting of generation | occurrence | production of a basal hydraulic braking force, since the regenerative braking device A generate | occur | produces the maximum regenerative braking force, it can ensure the area | region which restrict | limits generation | occurrence | production of a basal hydraulic braking force as long as possible. Accordingly, the generation of the basic hydraulic braking force can be delayed as much as possible, and the regenerative braking force can be utilized to the maximum extent without waste over the entire region where the brake pedal 21 is depressed.

  The basic hydraulic braking force generation limiting means is constituted by a master cylinder 23. The master cylinder 23 has a first port 23h provided in the first hydraulic chamber 23d of the master cylinder 23 and communicating with the reservoir tank 24. Provided at a second position corresponding to a predetermined state separated by a predetermined distance S in the pressure increasing direction of the first piston 23b from the first position corresponding to the depression start state of the closed end of the first piston 23b closing the port 23h. Therefore, the generation of the basic hydraulic braking force can be limited with a simple configuration.

  Further, the hydraulic brake device B applies the control hydraulic pressure formed by the driving of the pumps 37 and 47 and the control of the hydraulic pressure control valves 31 and 41 to the wheel cylinders WC1, WC, 2 of the wheels FR, FL, RR, RL. , WC3, WC4 so that the control hydraulic pressure braking force can be generated in each of the wheels FR, FL, RR, RL, and the basic hydraulic pressure control is performed by the basic hydraulic pressure braking force generation limiting means (master cylinder 23). When the generation of motive power is restricted and the fluctuation of the actual regenerative braking force is detected, the control fluid pressure is formed by driving the pumps 37 and 47 and controlling the fluid pressure control valves 31 and 41. , Braking force compensation means for generating a control hydraulic braking force based on the control hydraulic pressure on the wheels FR, FL, RR, and RL to compensate for a lack of regenerative braking force due to the detected fluctuation (steps 112 to 112 in FIG. 8). Because with a 16), regardless of the change in the regenerative braking force, the braking force demanded by the driver can be imparted stably.

Further, since the brake operation state is detected by a pedal stroke sensor (brake pedal stroke sensor) 21a that detects the stroke of the brake pedal 21, the brake operation state can be reliably and directly detected by the pedal stroke sensor 21a. The basic hydraulic pressure control force can be surely limited according to the brake operation state. In the first reference embodiment described above, the brake operation state may be detected by a master cylinder stroke sensor 23z that detects the stroke of the master cylinder 23. The master cylinder stroke sensor 23z transmits a detection signal to the brake ECU 60. Also in this case, the brake operation state can be reliably and directly detected by the master cylinder stroke sensor 232z, and the basic hydraulic pressure control force can be reliably limited according to the brake operation state.

  Further, since the reaction force spring 21b, which is a pedal reaction force forming means for forming the pedal reaction force of the brake pedal 21 until the brake operation state becomes the predetermined state, is provided, the brake pedal 21 is depressed and the brake operation state is changed. Until a predetermined state is reached, the driver can feel a good pedal feeling.

2) First Embodiment In the first reference embodiment described above, the basic hydraulic braking force generation limiting means is constituted by the master cylinder 23, which is provided in the first hydraulic pressure chamber 23d of the master cylinder 23 to provide a reservoir. The first port 23h communicating with the tank 24 is separated by a predetermined distance S in the pressure increasing direction of the first piston 23b from the first position corresponding to the depression start state of the closed end of the first piston 23b closing the port 23h. Instead of this, the basic hydraulic braking force generation limiting means replaces the suction ports of the pumps 37 and 47 constituting the hydraulic brake device B and the master cylinder 23 instead of the second position corresponding to the predetermined state. The oil paths Lf4 and Lf5 and the pressure regulation reservoirs 34 and 44 (pressure regulation reservoir 50) provided in the oil paths Lf4 and Lr5, respectively, are provided. It may be. The pressure adjusting reservoir 50 is a hydraulic pressure introducing portion, and the hydraulic pressure introducing portion is provided on the oil paths Lf and Lr, and the master cylinder 23 is in a period from when the brake operation state is changed to the predetermined state. The basic hydraulic pressure from the master cylinder 23 is restricted by introducing the basic hydraulic pressure from the master cylinder 23 to restrict the generation of the basic hydraulic braking force to a predetermined value or less. The restriction on the generation of the basic hydraulic braking force is released.

Specifically, as shown in FIG. 9, the pressure regulating reservoir 50 is a valve seat in which the ball valve 51a constituting the pressure regulating valve 51 of the pressure regulating reservoir 50 has a valve hole 51b1. The valve is closed in a predetermined state so that the valve is closed by a predetermined distance S1 in the valve opening direction (upward) from the valve closing position (see FIG. 7) that contacts the valve 51b and closes the valve hole 51b1. So as to be positioned. That is, the pin 55 is set so as to be longer by S1-S0 than the above-described first reference form . Further, the first port 23h of the master cylinder 23 is in a first position where the driver's foot is separated from the brake pedal 21, that is, the brake pedal 21 is not depressed, in the same manner as the second port 23i described above. A position where the closed end closing the port 23h of the first piston 23b in the return position (shown in FIG. 2) coincides with the open end of the first port 23h (that is, the closed end of the first piston 23b is the first port). 23h) just before the opening of 23h is started.

  The operation of the hydraulic brake device B configured as described above will be described with reference to FIGS. First, when the brake pedal 21 is not depressed and the master cylinder pressure (basic hydraulic pressure) is not formed, and the brake actuator 25 is not operated and the braking hydraulic pressure is not formed, the pressure regulating reservoir 50 The piston 54 has its upper end surface in contact with the upper end surface of the large-diameter hole 50a2 by the biasing force of the spring 56, and the ball valve 51a is positioned above the seat surface of the valve seat 51b by a predetermined amount S1. (See FIG. 9).

  During normal braking without driving the pumps 37 and 47, the differential pressure control valves 31, 41 and the pressure increase control valves 32, 33, 42, 43 are in communication, and the pressure reduction control valves 35, 36, 45, 46 are It is in a cut-off state. For this reason, the master cylinder pressure generated by the depression of the brake pedal 21 is directly applied to the wheel cylinders WC1, WC2, WC3, and WC4. At this time, the brake fluid from the master cylinder flows into the reservoir chamber 50d through the oil passages Lf5, Lr5 and the respective reservoir holes 50b, through the valve hole 51b1. However, when the piston 54 is pushed down by a predetermined amount S1 against the urging force of the spring 56 as the inflow amount increases, the ball valve 51a supported by the pin 55 is also moved and pressed against the valve seat 51b. The hole 51b1 is closed (see FIG. 7). As a result, the master cylinder pressure is not applied to the suction ports of the pumps 37 and 47.

  Note that the master cylinder pressure (basic hydraulic pressure) corresponding to the brake operation state is directly applied to the wheel cylinders WC1, WC2, WC3, WC4 only after the pressure regulating valve 51 is closed (becomes in a predetermined state). However, since the brake fluid from the master cylinder 23 flows into the reservoir chamber 50d through the pressure regulating valve 51 until it is closed (until a predetermined state), the basic fluid pressure corresponding to the brake operation state is applied to each wheel. Not given to cylinders WC1, WC2, WC3, WC4. At this time, since the brake fluid enters the pressure adjusting reservoir 50, a fluid pressure is generated although not as large as the basic fluid pressure corresponding to the brake operation state. Therefore, the fluid pressure is applied to each wheel cylinder WC1, WC2, WC3, WC4. Is done.

The basic hydraulic braking force by the basic hydraulic pressure formed by the hydraulic brake device A is as shown by the solid line in FIG. That is, when the brake pedal stroke is located between the depression start position and the position where the pressure regulating valve 51 is closed (closed), the stroke occurs in the first and second hydraulic chambers 23d and 23f of the master cylinder 23. Although the basic hydraulic pressure corresponds to the brake operation state, the basic hydraulic pressure generated because the pressure regulating valve 51 is open is absorbed by the pressure regulating reservoir 50 through the pressure regulating valve 51, and each wheel cylinder WC1, WC2, WC3. , Not given to WC4. Accordingly, generation of the basic hydraulic braking force is limited. When the brake pedal stroke is located at a position exceeding the position where the pressure regulating valve 51 is closed, the above-described generation restriction of the basic hydraulic pressure braking force is released, and the brake pedal stroke is generated in the first and second hydraulic pressure chambers 23d and 23f. Since the basic hydraulic pressure is applied to the wheel cylinders WC1, WC2, WC3, WC4, the basic hydraulic braking force also corresponds to the brake pedal stroke. The state where the pressure regulating valve 51 is located at the closed position starting position, that is, the state where the ball valve 51a of the pressure regulating valve 51 is in contact with the valve seat 51b is a predetermined state, and the basic hydraulic braking force corresponds to the brake pedal stroke. This is a brake operation state in which the increased pressure is started. Therefore, as shown by the solid line in FIG. 10, by applying the basic hydraulic pressure directly to the wheel cylinders WC1, WC2, WC3, WC4, the foundation corresponding to the basic hydraulic pressure is applied to the wheels FR, FL, RR, RL. A hydraulic braking force can be generated. Also according to the first embodiment, the generation of basic hydraulic braking force is limited with a simple configuration by using the existing brake actuator (automatic pressurizing device) 25 without adding a new device. can do.

In the first embodiment described above, the pressure regulating reservoir 50 is employed as the hydraulic pressure introducing portion. However, the pressure regulating reservoir 50 is provided on the oil paths Lf and Lr, and the brake operation state changes from the stepping start state to the predetermined state. In the meantime, the basic hydraulic pressure from the master cylinder 23 is introduced to limit the generation of the basic hydraulic braking force to a predetermined value or less, and when the brake operation state is after the predetermined state, the basic hydraulic pressure from the master cylinder 23 is reduced. Other constituent members may be employed as long as the introduction of the hydraulic pressure is restricted and the restriction on the generation of the basic hydraulic braking force is released.

3) Second Reference Form In the first reference form described above, the basic hydraulic braking force generation limiting means is constituted by the master cylinder 23, and is provided in the first hydraulic pressure chamber 23d of the master cylinder 23 to provide a reservoir. The first port 23h communicating with the tank 24 is separated by a predetermined distance S in the pressure increasing direction of the first piston 23b from the first position corresponding to the depression start state of the closed end of the first piston 23b closing the port 23h. Instead of this, the basic hydraulic braking force generation restricting means is provided with both members 21 and 23b between the brake pedal 21 and the first piston 23b of the master cylinder 23. You may make it comprise the connection member (for example, operating rod 26, push rod 27, etc.) provided in order to connect. A case where the operating rod 26 is employed as the connecting member will be described.

Specifically, as shown in FIG. 11, the operating rod 26 applies the operating force applied to the brake pedal 21 to the first piston 23 b of the master cylinder 23 during the period from when the brake operation state starts to the predetermined state. An operation force transmission mechanism 70 configured to transmit the operation force applied to the brake pedal 21 to the first piston 23b of the master cylinder 23 after a predetermined state is provided. The operating force transmission mechanism 70 is provided at a joint portion between the first operating rod 26a and the second operating rod 26b constituting the operating rod 26. A cylindrical portion 71 is formed at the other end of the first operating rod 26a to which the brake pedal 21 is attached at one end, and reciprocatingly moves in the cylindrical portion 71 at one end of the second operating rod 26b. A cylindrical engagement portion 72 that is housed in this manner is formed. The cylindrical engaging portion 72 is prevented from coming off from the cylindrical portion 71. Further, a spring 73 that biases both members in the reciprocating direction is accommodated between the cylindrical portion 71 and the cylindrical engaging portion 72. The master cylinder 23 is configured in the same manner as in the first embodiment, and the pressure regulating reservoir 50 is configured in the same manner as in the first reference embodiment .

  The operation of the hydraulic brake device B having the connecting member configured as described above will be described. First, when the brake pedal 21 is not depressed and the master cylinder pressure (basic hydraulic pressure) is not formed, and the brake actuator 25 is not operated and the braking hydraulic pressure is not formed, the operating force transmission mechanism Reference numeral 70 denotes the state shown in FIG. 11, and the operating rod 26 has the maximum length due to the urging force of the spring 73.

  When the brake pedal 21 is stepped on, the first operating rod 26a is moved toward the second operating rod 26b against the urging force of the spring 73 by the operating force. At this time, the biasing force of the spring 73 is set to be smaller than the biasing forces of the return spring of the negative pressure booster 22 that returns the second operating rod 26b and the springs 23e and 23g of the master cylinder 23. The spring 73 is compressed, but the second operating rod 26b is not moved. That is, since the master cylinder pressure is limited to be formed in the master cylinder 23, the master cylinder pressure is not applied to the wheel cylinders WC1, WC2, WC3, and WC4.

  Further, when the brake pedal 21 is stepped on and the cylindrical engaging portion 72 comes into contact with one end face of the cylindrical portion 71, the second operating rod 26b is moved together with the first operating rod 26a by the operating force thereafter. That is, the master cylinder pressure starts to be formed in the master cylinder 23, and the master cylinder pressure generated by the depression of the brake pedal 21 is applied to the wheel cylinders WC1, WC2, WC3, and WC4. When the depression of the brake pedal 21 is released, the operating force transmission mechanism 70 is returned to the state shown in FIG.

The basic hydraulic braking force by the basic hydraulic pressure formed by the hydraulic brake device A is as shown by the solid line in FIG. That is, when the brake pedal stroke is located between the depression start position and the position where the first operating rod 26a contacts the second operating rod 26b, the first and second hydraulic chambers 23d, 23f of the master cylinder 23 Since the generated basic hydraulic pressure is limited to zero, the generation of the basic hydraulic braking force is also limited to zero. When the brake pedal stroke is located at a position beyond the position where the first operating rod 26a contacts the second operating rod 26b, the above-described basic fluid pressure generation restriction is released, and the first and second fluids are released. Since the basic hydraulic pressure generated in the pressure chambers 23d and 23f corresponds to the brake pedal stroke, the basic hydraulic pressure braking force also corresponds to the brake pedal stroke. Note that the state where the first operating rod 26a is located at a position where it abuts against the second operating rod 26b is a predetermined state, and the basic hydraulic braking force is a brake operation state in which pressure increase corresponding to the brake pedal stroke is started. Therefore, as shown by the solid line in FIG. 5, by applying the basic hydraulic pressure directly to the wheel cylinders WC1, WC2, WC3, WC4, the foundation corresponding to the basic hydraulic pressure is applied to the wheels FR, FL, RR, RL. A hydraulic braking force can be generated. Also according to the second reference embodiment , the generation of the basic hydraulic braking force can be limited with a simple configuration.

In each reference embodiment and embodiment described above, a reaction force actuator 80 may be employed as the pedal reaction force means as shown in FIG. The reaction force actuator 80 includes a spring 80 a that applies a force (that is, a pedal reaction force) to the brake pedal 21 in a direction opposite to the stepping direction, and a motor 80 b that is driven by the brake ECU 43. With these configurations, the pedal reaction force by the spring 80a can be adjusted by the motor 80b so that the pedal reaction force can be varied. The reaction force actuator 80 applies a pedal reaction force to the brake pedal 21 according to the calculation result of the brake ECU 60.

Moreover, in each reference form and embodiment described above, the brake piping system is configured by the front and rear division system, but may be configured by the X piping system.

In each reference embodiment and embodiment described above, when the brake operation state is a predetermined state or later, the larger one of the pedal stroke and the master cylinder pressure may be selected and used for control as the brake operation state. .

In each reference embodiment and embodiment described above, a negative pressure type booster is used as the booster. However, the hydraulic pressure generated by the pump is accumulated in an accumulator, and this hydraulic pressure is applied to the piston to cause the brake pedal. The pedal depression force acting on 21 may be boosted.

  Further, the present invention can be applied not only to a hybrid vehicle, but also to a vehicle on which only a motor is mounted as a drive source and a vehicle brake device having a master cylinder with a negative pressure booster. In this case, a negative pressure source is required.

  DESCRIPTION OF SYMBOLS 11 ... Engine, 12 ... Motor, 13 ... Power split mechanism, 14 ... Power transmission mechanism, 15 ... Generator, 16 ... Inverter, 17 ... Battery, 18 ... Engine ECU, 19 ... Hybrid ECU, 21 ... Brake pedal, 21a ... Pedal stroke sensor, 21b ... reaction force spring, 22 ... negative pressure booster, 23 ... master cylinder, 23a ... housing, 23b, 23c ... first and second pistons, 23d ... first hydraulic chamber, 23e ... first spring , 23f ... second hydraulic chamber, 23g ... second spring, 23h ... first port, 23i ... second port, 23j ... third port, 23k ... fourth port, 24 ... reservoir tank, 25 ... brake actuator, 26 ... operating rod, 27 ... push rod, 31, 41 ... hydraulic pressure control valve, 32, 33, 42, 4 ... Pressure increase control valve, 35, 36, 45, 46 ... Pressure reduction control valve, 34, 44, 50 ... Pressure regulating reservoir, 37, 47 ... Pump, 50a ... Stepped hole, 50a1 ... Small diameter hole, 50a2 ... Large diameter hole 50b, 50c ... reservoir hole, 50d ... reservoir chamber, 51 ... pressure regulating valve, 51a ... ball valve, 51b ... valve seat, 51b1 ... valve hole, 52 ... spring, 53 ... closing member, 54 ... piston, 55 ... pin, 56 ... Spring, 60 ... Brake ECU, 70 ... Operating force transmission mechanism, 26a ... First operating rod, 26b ... Second operating rod, 71 ... Cylindrical portion, 72 ... Cylindrical engaging portion, 73 ... Spring, 80 ... Anti Force actuator, 80a ... spring, 80b ... motor, A ... regenerative brake device, B ... hydraulic brake device, BK1, BK2, BK3, BK4 ... brake means, FR FL, RR, RL ... wheels, Lf, Lr ... oil path, M ... motor, P ... pressure sensor, Sfl, Sfr, Srl, Srr ... wheel speed sensors, WC1, WC2, WC3, WC4 ... wheel cylinder.

Claims (4)

The base hydraulic pressure corresponding to the brake operation state caused by depressing the brake pedal is generated in the master cylinder, and the generated basic hydraulic pressure is connected to the wheel of each wheel via an oil path through the master cylinder and the hydraulic control valve. A hydraulic brake device that generates a basic hydraulic braking force corresponding to the basic hydraulic pressure on each wheel by directly applying to the cylinder;
A regenerative braking device that generates a regenerative braking force based on the brake operation state on any of the wheels, and
In the vehicle brake device that applies a vehicle braking force corresponding to the brake operation state to the vehicle based on the basic hydraulic braking force and the regenerative braking force by cooperatively operating the hydraulic brake device and the regenerative braking device,
When the brake pedal is depressed, the basic hydraulic braking force is limited so that the basic hydraulic braking force is less than or equal to a predetermined value until the brake operation state reaches the predetermined state from the depression start state, which is the state at the start of depression. Further comprising hydraulic braking force generation limiting means,
The basic hydraulic braking force generation limiting means is provided on the oil path and introduces basic hydraulic pressure from the master cylinder until the brake operation state is changed from the stepping start state to the predetermined state. Generation of the basic hydraulic braking force is limited to the predetermined value or less, and when the brake operation state is after the predetermined state, the introduction of the basic hydraulic pressure from the master cylinder is restricted to control the basic hydraulic pressure control. It consists of a hydraulic pressure introduction part that releases the restriction of power generation,
When the brake operation state becomes the predetermined state, the basic hydraulic pressure braking force generation limiting means releases the restriction on the generation of the basic hydraulic pressure braking force, and the regenerative brake device generates the maximum regenerative braking force,
The hydraulic brake device sucks in brake fluid from the master cylinder or the wheel cylinder, and brake fluid stored in the brake fluid from the wheel cylinder or in the pressure reservoir. A pump for discharging to the master cylinder, and a control formed by driving the pump and controlling the hydraulic pressure control valve independently of the basic hydraulic pressure generated corresponding to the brake operation state By applying hydraulic pressure to each wheel cylinder, it is configured to be able to generate a control hydraulic braking force on each wheel corresponding to each wheel cylinder,
The fluid pressure introducing part is configured from the pressure regulating reservoir,
The ball valve constituting the pressure regulating valve of the pressure regulating reservoir is a predetermined distance in the valve opening direction from the valve closing position where the ball valve contacts the valve seat having the valve hole and closes the valve hole in the stepping start state. The vehicular brake device is positioned so as to be in the valve closed position in the predetermined state so as to be in a position apart from each other . Oite to claim 1, wherein the hydraulic brake device is reservoir of brake fluid from the master cylinder or the wheel cylinder and the pressure control reservoir to reservoir, the brake fluid or the pressure regulating reservoir from said wheel cylinder A pump that sucks in the brake fluid and discharges it to the master cylinder, and drives the pump and the fluid pressure control valve independently of the basic fluid pressure generated in response to the brake operation state. By applying a control hydraulic pressure formed by the control of each wheel cylinder to each wheel cylinder, a control hydraulic braking force can be generated on each wheel corresponding to the wheel cylinder,
When the generation of the basic hydraulic braking force is limited by the basic hydraulic braking force generation limiting means, when the fluctuation of the actual regenerative braking force is detected, the pump is driven and the hydraulic pressure control valve is controlled. A braking force compensation means for forming the control hydraulic pressure by generating the control hydraulic pressure braking force based on the control hydraulic pressure and compensating for the lack of regenerative braking force due to the detected fluctuation. A brake device for a vehicle. According to claim 1 or claim 2, wherein the brake operation state, vehicle and detecting by the master cylinder stroke sensor for detecting a stroke of the brake pedal stroke sensor or the master cylinder for detecting the stroke of the brake pedal Brake device. The vehicle according to any one of claims 1 to 3 , further comprising pedal reaction force forming means for forming a pedal reaction force of the brake pedal until the brake operation state reaches the predetermined state. Brake device.

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