JP5652168B2 - Hydraulic brake system - Google Patents

Description

  The present invention relates to a hydraulic brake system including a hydraulic brake that suppresses rotation of a wheel.

In Patent Document 1, (a) a hydraulic brake that suppresses rotation of a wheel, (b) a master cylinder, (c) an accumulator, and (d) a drive of an electric actuator using the hydraulic pressure of the accumulator A pressure increasing mechanism that is actuated by the hydraulic pressure sensor, and (e) a selection valve that selects a higher one of the hydraulic pressure of the pressure increasing mechanism and the hydraulic pressure of the master cylinder and supplies the selected pressure to the brake cylinder of the hydraulic brake. A pressure brake system is described.
In Patent Document 2, (a) a hydraulic brake that is provided on the front, rear, left, and right wheels of the vehicle and suppresses the rotation of the wheel, (b) a master cylinder, and (c) a hydraulic brake brake for the master cylinder and the front wheels. A hydraulic brake system including a mechanical booster provided between the cylinder and (d) a high-pressure source and an electromagnetic valve that controls the hydraulic pressure of the high-pressure source is described.

Special table 2009-502645 Japanese Patent Laid-Open No. 10-287227

  An object of the present invention is to improve a hydraulic brake system.

Means and effects for solving the problem

In the hydraulic brake system according to the present invention, an input side shut-off valve, which is an electromagnetic on-off valve, is provided between the pressure booster and the manual hydraulic pressure source.
If an input-side shut-off valve is provided, for example, when it is less necessary to operate the pressure booster, it can be closed, and the hydraulic pressure of the manual hydraulic pressure source is not supplied to the pressure booster. Can do.
In principle, the operation of the pressure booster is allowed in the open state of the input side shutoff valve, but the operation of the pressure booster is prohibited or suppressed in the closed state of the input side shutoff valve.

Patentable invention

  In the following, the invention that is claimed to be claimable in the present application (hereinafter referred to as “claimable invention”. The claimable invention is at least the “present invention” to the invention described in the claims. Some aspects of the present invention, including subordinate concept inventions of the present invention, superordinate concepts of the present invention, or inventions of different concepts) will be illustrated and described. Each aspect is divided into a term like a claim, and it describes in the format which attaches a number to each term. The constituent elements constituting the claimable invention may be those described in the following items, or described in two or more sets of each item. In addition, an aspect in which another component is added to the aspect of each term, and an aspect in which the constituent element is deleted from the aspect of each term can also be an aspect of the claimable invention.

(1) a brake operation member provided on the vehicle and operable by a driver;
At least one manual hydraulic pressure source that generates hydraulic pressure by operating the brake operating member;
A pressure increasing device which is operated by at least one hydraulic pressure of the at least one manual hydraulic pressure source and which can output a hydraulic pressure higher than the hydraulic pressure of the one manual hydraulic pressure source;
A hydraulic brake system comprising: an input side shut-off valve that is an electromagnetic on-off valve provided between the pressure increasing device and the one manual hydraulic pressure source.
The manual hydraulic pressure source can be a pressurizing chamber of the master cylinder or a hydraulic booster. When the hydraulic brake system is provided with a master cylinder having one pressurizing chamber and a hydraulic booster, it can be considered that the hydraulic brake system includes two manual hydraulic pressure sources. Similarly, when the master cylinder includes two pressurizing chambers, it can be considered that two manual hydraulic pressure sources are included.
The input-side shut-off valve is an electromagnetic on-off valve that can take at least an open state and a closed state. The electromagnetic on-off valve continuously determines the amount of current supplied to the solenoid (strictly speaking, current is supplied to a coil included in the solenoid, but hereinafter, abbreviated as current supplied to the solenoid). Even if it is a linear control valve that can continuously control the differential pressure (and / or opening) between the front and the back by controlling, it can be in either the open state or the closed state by ON / OFF control of the supply current. It may be a simple on-off valve that can be switched. Hereinafter, in the present specification, unless it is described as “linear control valve” or “simple on / off valve”, “valve” such as an electromagnetic on / off valve, electromagnetic control valve, and hydraulic control valve is a “linear control valve”. Also, it may be a “simple on-off valve”.
One manual hydraulic pressure source connected to the pressure booster can be referred to as a pressure booster connected manual hydraulic pressure source.
None of Patent Documents 1 and 2 describes that an electromagnetic on-off valve is provided between the pressure booster and the manual hydraulic pressure source. In Patent Document 1, a directional switching valve is provided between the pressure increasing device, the master cylinder, and the accumulator, but the directional switching valve and the on-off valve are different.
(2) The hydraulic brake system includes a hydraulic brake that is provided corresponding to each of the plurality of wheels provided in the vehicle, is operated by the hydraulic pressure of the brake cylinder, and suppresses the rotation of the wheels. Including two manual hydraulic pressure sources, and
One of the two manual hydraulic pressure sources is connected to the first brake cylinder, which is at least one of the plurality of brake cylinders, via the first manual passage, bypassing the pressure increasing device,
The other of the two manual hydraulic pressure sources is connected to the second brake cylinder, which is at least one of the plurality of brake cylinders, via the pressure increasing device,
The input-side shutoff valve is a normally open valve provided between the other manual hydraulic pressure source and the pressure booster.
Each of the first brake cylinder and the second brake cylinder may be one or two or more. The first brake cylinder and the second brake cylinder may be the same, different, or partially the same, and one may include the other.
For example, the first brake cylinder can be any one of the left and right front wheels, and the second brake cylinder can be two or more brake cylinders including the left and right front wheels. The second brake cylinder may include a first brake cylinder.
Specifically, the first brake cylinder can be used as the right front wheel brake cylinder, the second brake cylinder can be used as the left and right front wheel brake cylinder, and the left and right front wheels and the left and right rear wheels can be used as the brake cylinder.
(3) The other manual hydraulic pressure source and at least one of the second brake cylinders are connected via a second manual passage, bypassing the pressure increasing device.
The other manual hydraulic pressure source is connected to at least one of the second brake cylinders (hereinafter sometimes referred to as a third brake cylinder) via a pressure increasing device, and a second manual passage is provided. It is connected directly via.
If a manual shut-off valve is provided in the second manual passage, the manual hydraulic pressure can be directly communicated with the third brake cylinder by the control of both the manual shut-off valve and the input-side shut-off valve. It is possible to selectively switch between a source communication state and a pressure booster communication state in which the other manual hydraulic pressure source is connected via a pressure booster.
On the other hand, when the pressure increasing device includes a pressure increasing device internal passage capable of communicating with the other manual hydraulic pressure source and the second brake cylinder, the third manual passage is provided by the liquid passage including the pressure increasing device internal communication passage. Can be considered to be constructed.
The first manual passage and the second manual passage are directly connected manual passages that directly connect the manual hydraulic pressure source and the brake cylinder, bypassing the pressure booster, and the third manual passage is provided with the pressure booster. It is a non-direct connection (bypass) manual passage that connects the manual hydraulic pressure source and the brake cylinder.
(4) The hydraulic brake system includes a first manual shut-off valve that is a normally closed electromagnetic on-off valve provided in the first manual passage and a normally closed electromagnetic on-off valve provided in the second manual passage. And a second manual shut-off valve.
When the electric system is abnormal, the second manual shut-off valve is closed and the input shut-off valve is opened, so that the third brake cylinder is supplied with the servo pressure that is the output hydraulic pressure of the pressure booster. The Therefore, the hydraulic pressure supplied to the third brake cylinder can be increased as compared with the case where the hydraulic pressure of the other manual hydraulic pressure source is directly supplied.
The input side shut-off valve can be considered as a normally open manual shut-off valve provided in the third manual passage.
(5) The hydraulic brake system includes a common passage to which the plurality of brake cylinders are connected, and the pressure increasing device is operable by (a) at least the hydraulic pressure of the other manual hydraulic pressure source. A movable portion provided with a piston, (b) a bypass passage that bypasses the movable portion and connects the other manual hydraulic pressure source and the common passage, and (c) provided in the bypass passage, An input-side check valve that prevents the flow of hydraulic fluid from the common passage to the other manual hydraulic pressure source and allows the hydraulic fluid to flow from the other manual hydraulic source to the common passage. It can be.
If the input side shut-off valve is closed, the forward movement of the piston can be suppressed or prevented. The operation of the movable part can be suppressed, and the operation of the pressure booster can be suppressed.
(6) The hydraulic brake system is connected to the common passage and generates a hydraulic pressure by supplying electric energy, and a plurality of the hydraulic brake systems using the hydraulic pressure of the hydraulic pressure source. And a power hydraulic pressure control device capable of controlling the hydraulic pressure of the brake cylinder.
The power hydraulic pressure source includes, for example, a pump device that generates a hydraulic pressure by supplying electric energy, but may include an accumulator that stores hydraulic fluid discharged from the pump device in a pressurized state. While the hydraulic fluid is stored in the accumulator in a pressurized state, high-pressure hydraulic fluid can be supplied to the pressure increasing device.
The power hydraulic pressure control device includes a hydraulic pressure control valve provided between the power hydraulic pressure source and the common passage, and can control the hydraulic pressure supplied to the common passage by controlling the hydraulic pressure control valve. (Including a hydraulic pressure control valve provided between the common passage and the low pressure source), or control the power hydraulic pressure source (for example, control of a pump motor, etc.) to be supplied to the common passage. The fluid pressure can be controlled.
Further, the hydraulic pressure control valve provided between the power hydraulic pressure source and the common passage also has a function as an output side shut-off valve that shuts off the power hydraulic pressure source from the common passage.
(7) When the hydraulic brake system is in a state in which the power hydraulic pressure control device can control the hydraulic pressures of the plurality of brake cylinders, the second input-side shut-off that closes the input-side shut-off valve Includes a valve controller.
When the hydraulic pressures of a plurality of brake cylinders are controlled by the power hydraulic pressure control device, it is not necessary to operate the pressure increase device. In this case, it is desirable that the input side shut-off valve is closed. If the input side shut-off valve is closed when it is less necessary to operate the pressure booster, vibrations can be suppressed and operating noise can be reduced.
In addition, when the power hydraulic pressure control device is normal and a brake operation is performed, the input shutoff valve can be closed.
(8) The hydraulic brake system
A stroke simulator connected to the other manual hydraulic pressure source;
A first input side shut-off valve that closes the input side shut-off valve when the operation of the stroke simulator is permitted and opens the input side shut-off valve when the operation of the stroke simulator is blocked And a control device.
For example, when the stroke simulator is connected to the other manual hydraulic pressure source and a simulator control valve is provided between the other manual hydraulic pressure source and the stroke simulator, the simulator control valve is opened. The stroke simulator is communicated with the other manual hydraulic pressure source and the operation of the stroke simulator is permitted. In the closed state of the simulator control valve, the stroke simulator is disconnected from the other manual hydraulic pressure source, and the operation of the stroke simulator is prevented. The stroke simulator is permitted when the hydraulic pressure of the brake cylinder is controlled by the power hydraulic pressure control device.
If the input side shut-off valve is not provided, both the stroke simulator and the pressure booster are in communication with the other manual hydraulic pressure source. In both the stroke simulator and the pressure booster, the hydraulic pressure applied to the hydraulic pressure corresponding to the force required for the start of the operation in which the hydraulic pressure applied to it is determined by the set load of the spring, the frictional force of the movable part (sliding resistance, etc.) It does not operate while it is smaller than the operation start pressure), but is activated when it becomes greater than the operation start pressure. In this case, the operation start pressure of the stroke simulator and the operation start pressure of the pressure increasing device are not necessarily the same. When the operation start pressure of the stroke simulator is smaller than the operation start pressure of the pressure booster, the pressure booster will be operated after the stroke simulator is started. As a result, the brake operating member enters.
On the other hand, if the input side shut-off valve is closed when the operation of the stroke simulator is permitted, the brake operation member is prevented from entering when the brake operation force exceeds the operation start pressure of the pressure booster. It is possible to prevent the driver's operation feeling from deteriorating.
(9) A high-pressure shut-off valve can be provided between the pressure booster and the power hydraulic pressure source.
When the high-pressure shut-off valve is opened, the operation of the pressure booster is allowed, and when it is closed, the operation of the pressure booster is blocked in principle. Therefore, it is desirable that the input side shut-off valve is opened when the high-pressure shut-off valve is open, and the pressure booster is closed when the high-pressure shut-off valve is closed.
Also, if the high-pressure shut-off valve is closed and the input-side shut-off valve is closed, the pressure booster can be deactivated without providing an output-side shut-off valve between the pressure booster and the common passage. Can be held.
The high-pressure shut-off valve can be a normally open electromagnetic on-off valve.

1 is a diagram showing an entire vehicle equipped with a hydraulic brake system that is a common embodiment of the present invention. It is a circuit diagram showing the hydraulic brake circuit of the hydraulic brake system which concerns on Example 1 of this invention. It is sectional drawing of the pressure increase linear control valve contained in the said hydraulic brake circuit. It is a figure which shows the input side non-return valve contained in the said hydraulic brake circuit. (a) is a sectional view of a cup seat type check valve, (bi) is a sectional view of a ball type check valve, (b-ii) is an AA sectional view of (bi), (c) is a diagram conceptually showing a magnetic check valve. It is a flowchart showing the hydraulic pressure supply state control program memorize | stored in the memory | storage part of brake ECU contained in the said hydraulic brake system. In the said hydraulic brake system, it is a figure which shows a state when a supply state control program is performed (when normal). In the said hydraulic brake system, it is a figure which shows another state when a supply state control program is performed (when a control system is abnormal). In the said hydraulic brake system, it is a figure which shows another state when a supply state control program is performed (when a control system is abnormal). FIG. 3 is a diagram showing a state where an ignition switch is OFF in the hydraulic brake system (when there is a possibility of liquid leakage). It is a hydraulic-brake circuit diagram of the hydraulic-brake system which concerns on Example 2 of this invention. It is a hydraulic-brake circuit diagram of the hydraulic-brake system which concerns on Example 3 of this invention. (a) A hydraulic brake circuit diagram of a hydraulic brake system according to a fourth embodiment of the present invention. (b) A right-hand drive vehicle equipped with the hydraulic brake system. (a) A hydraulic brake circuit diagram of a hydraulic brake system according to a fifth embodiment of the present invention. (b) A right-hand drive vehicle equipped with the hydraulic brake system. (a) A hydraulic brake circuit diagram of a hydraulic brake system according to a sixth embodiment of the present invention. (b) A right-hand drive vehicle equipped with the hydraulic brake system. (a) A hydraulic brake circuit diagram of a hydraulic brake system according to a seventh embodiment of the present invention. (b) A right-hand drive vehicle equipped with the hydraulic brake system. FIG. 10 is a hydraulic brake circuit diagram of a hydraulic brake system according to an eighth embodiment of the present invention. It is a figure which shows a state when the supply state control program is performed in the said hydraulic brake system (when a system is normal). In the said hydraulic brake system, it is a figure which shows another state when a supply state control program is performed (when a control system is abnormal). In the said hydraulic brake system, it is a figure which shows another state when a supply state control program is performed (when a control system is abnormal). In the said hydraulic brake system, it is a figure which shows another state at the time of a supply state control program being performed (when there exists a possibility of a liquid leak). It is a flowchart which shows the check program memorize | stored in the memory | storage part of brake ECU of the said hydraulic brake system. (a) It is a figure which shows the state in case the check program is performed in the said hydraulic brake system (check 1). (b) It is a figure which shows the relationship between the hydraulic pressure of the input side of a pressure booster, and the hydraulic pressure of an output side. It is a figure which shows a state in case the check program is performed in the said hydraulic brake system (check 2-1). It is a figure which shows another state when a check program is performed in the said hydraulic brake system (check 2-2). It is a figure which shows the change of the hydraulic pressure of the small diameter side chamber when the check 2 is performed. (a) It is a figure which shows the change of the hydraulic pressure at the time of controlling so that it may become a target hydraulic pressure. (b) It is a figure which shows the change of the hydraulic pressure when a high pressure cutoff valve is switched from a closed state to an open state. (c) It is a figure which shows the change of the hydraulic pressure of a small diameter side chamber in case a check different from the checks 1 and 2 is performed. It is a flowchart (when check 2 is executed) showing a part of the check program.

Hereinafter, a hydraulic brake system which is a plurality of embodiments of the present invention will be described in detail with reference to the drawings. First, a vehicle equipped with a hydraulic brake system that is a hydraulic brake system according to a plurality of embodiments of the present invention will be described.
As shown in FIG. 1, the vehicle is a hybrid vehicle that includes an electric motor and an engine as a drive device. In the hybrid vehicle, the left and right front wheels 2 and 4 as drive wheels are driven by a drive device 10 including an electric drive device 6 and an internal combustion drive device 8. The driving force of the driving device 10 is transmitted to the left and right front wheels 2 and 4 via the drive shafts 12 and 14. The internal combustion drive 8 includes an engine 16, an engine ECU 18 that controls the operating state of the engine 16, and the like. The electrical drive 6 includes an electric motor 20, a power storage device 22, a motor generator 24, a power conversion device 26, A motor ECU 28, a power split mechanism 30 and the like are included. When the electric motor 20, the motor generator 24, and the engine 16 are connected to the power split mechanism 30, and only the driving torque of the electric motor 20 is transmitted to the output member 32 by these controls, the driving torque of the engine 16 and the electric power When both the driving torque of the motor 20 is transmitted, the output is switched to when the output of the engine 16 is output to the motor generator 24 and the output member 32, or the like. The driving force transmitted to the output member 32 is transmitted to the drive shafts 12 and 14 via a speed reducer and a differential device. The power conversion device 26 includes an inverter and the like, and is controlled by the motor ECU 28. By the current control of the inverter, at least a rotational drive state in which electric energy is supplied to the electric motor 20 from the power storage device 22 and rotated, and charging that charges the power storage device 22 by functioning as a power generator by regenerative braking Switch to state. In the charged state, regenerative braking torque is applied to the left and right front wheels 2 and 4. In that sense, the electric drive device 6 can be considered as a regenerative brake device.

  The hydraulic brake system includes a brake cylinder 42 of the hydraulic brake 40 provided on the left and right front wheels 2, 4, a brake cylinder 52 of the hydraulic brake 50 provided on the left and right rear wheels 46 and 48 (see FIG. 2 and the like), A hydraulic pressure control unit 54 capable of controlling the hydraulic pressure of the brake cylinders 42 and 52 is included. The hydraulic pressure control unit 54 is controlled by a brake ECU 56 mainly including a computer. The vehicle is provided with a hybrid ECU 58, and the hybrid ECU 58, the brake ECU 56, the engine ECU 18, and the motor ECU 28 are connected via a CAN (Car area Network) 59. These can communicate with each other, and necessary information is communicated as appropriate.

  In addition, this hydraulic brake system can also be mounted not only on a hybrid wheel but on a plug-in hybrid vehicle, an electric vehicle, and a fuel cell vehicle. In the electric vehicle, the internal combustion drive device 8 is not necessary. In a fuel cell vehicle, a driving motor is driven by a fuel cell stack or the like. The present hydraulic brake system can also be mounted on an internal combustion drive vehicle. In a vehicle in which the electric drive device 6 is not provided, regenerative braking torque is not applied to the drive wheels 2, 4, so regenerative cooperative control is not performed.

  Hereinafter, the hydraulic brake system will be described, but when it is necessary to distinguish the brake cylinder, the hydraulic brake, and various electromagnetic on-off valves, which will be described later, according to the positions of the front, rear, left and right wheels, It is described with reference numerals (FL, FR, RL, RR) to be represented, and representatively or when it is not necessary to distinguish, it is described without reference numerals.

The hydraulic brake system according to the first embodiment includes a brake circuit shown in FIG. Reference numeral 60 denotes a brake pedal as a brake operation member, and reference numeral 62 denotes a master cylinder that generates hydraulic pressure by operating the brake pedal 60. A power hydraulic pressure source 64 includes a pump device 65 and an accumulator 66. The hydraulic brakes 40 and 50 are actuated by the hydraulic pressure of the brake cylinders 42 and 52 to suppress the rotation of the wheels. In the present embodiment, the hydraulic brakes 40 and 50 are disc brakes. The hydraulic brakes 40 and 50 can be drum brakes. Alternatively, the hydraulic brake 40 for the front wheels 2 and 4 can be a disc brake, and the hydraulic brake 50 for the rear wheels 46 and 48 can be a drum brake.
The master cylinder 62 is of a tandem type having two pressure pistons 68 and 69, and the pressure chambers 70 and 72 are in front of the pressure pistons 68 and 69, respectively. In this embodiment, the pressurizing chambers 70 and 72 correspond to manual hydraulic pressure sources, respectively. The pressurizing chambers 72 and 70 are respectively connected to the brake cylinder 42FL of the hydraulic brake 40FL of the left front wheel 2 and the brake cylinder of the hydraulic brake 40FR of the right front wheel 4 via master passages 74 and 76 as manual passages. 42FR is connected. The pressurizing chambers 70 and 72 are communicated with the reservoir 78 when the pressurizing pistons 68 and 69 reach the retracted end, respectively. The interior of the reservoir 78 is partitioned into a plurality of storage chambers 80, 82, and 84 that store hydraulic fluid. The accommodating chambers 80 and 82 are provided corresponding to the pressurizing chambers 70 and 72, respectively, and the accommodating chamber 84 is provided corresponding to the pump device 65.

  In the motive power hydraulic pressure source 64, the pump device 65 includes a pump 90 and a pump motor 92, and the hydraulic fluid is pumped up from the storage chamber 84 of the reservoir 78 by the pump 90, and is stored in the accumulator 66. The pump motor 92 is controlled so that the pressure of the hydraulic fluid stored in the accumulator 66 is within a predetermined setting range. Further, the relief valve 93 prevents the discharge pressure of the pump 90 from becoming excessive.

  A mechanical pressure booster 96 as a pressure booster is provided between the power hydraulic pressure source 64, the master cylinder 62, and the brake cylinders 42 and 52. The mechanical pressure booster 96 includes a mechanical movable portion 98 as a movable portion, an input side check valve 99, and a high pressure side check valve 100. The mechanical movable portion 98 includes a housing 102 and a stepped piston 104 that is fluid-tight and slidably fitted to the housing 102. A large-diameter side chamber 110 is provided on the large-diameter side of the stepped piston 104. A small-diameter side chamber 112 is provided on the small-diameter side. The pressurizing chamber 72 is connected to the large-diameter side chamber 110. In the present embodiment, the pressurizing chamber 72 corresponds to a pressure-increasing device connection manual hydraulic pressure source (one manual hydraulic pressure source). A high pressure chamber 114 connected to the power hydraulic pressure source 64 is communicated with the small diameter side chamber 112, and a high pressure supply valve 116 is provided between the small diameter side chamber 112 and the high pressure chamber 114. The high-pressure supply valve 116 includes a valve seat 122 formed in the housing 102, a valve element 120 provided so as to be able to approach and separate from the valve seat 122, and a spring 124. This acts in a direction to press the child 120 against the valve seat 122. The high pressure supply valve 116 is a normally closed valve. In the small diameter side chamber 112, a valve opening member 125 is provided so as to face the valve element 120, and a spring 126 is provided between the valve opening member 125 and the stepped piston 104. The biasing force of the spring 126 acts in a direction to separate the valve opening member 125 and the stepped piston 104 from each other. The valve opening member 125 can also be considered as a component of the high pressure supply valve 116.

  A spring 128 (return spring) is provided between the step portion of the stepped piston 104 and the housing 102 to urge the stepped piston 104 in the backward direction. A stopper (not shown) is provided between the stepped piston 104 and the housing 102 to restrict the forward end position of the stepped piston 104. Further, in the stepped piston 104, an in-piston communication passage 129 that connects the large-diameter side chamber 110 and the small-diameter side chamber 112 is formed, and an in-piston check valve 130 is provided in the middle of the in-piston communication passage 129. The piston check valve 130 blocks the flow of hydraulic fluid from the large-diameter side chamber 110 toward the small-diameter side chamber 112 and allows the hydraulic fluid to flow from the small-diameter side chamber 112 toward the large-diameter side chamber 110.

  The high pressure check valve 100 is provided in the middle of the high pressure supply passage 132 that connects the high pressure chamber 114 and the power hydraulic pressure source 64. The high pressure side check valve 100 allows the flow of hydraulic fluid from the power hydraulic pressure source 64 to the high pressure chamber 114 when the hydraulic pressure of the power hydraulic pressure source 64 is higher than the hydraulic pressure of the high pressure chamber 114. When the hydraulic pressure of the motive power hydraulic pressure source 64 is equal to or lower than the hydraulic pressure of the high pressure chamber 114, the power supply pressure source 64 is in a closed state and prevents bidirectional flow. Therefore, even if the hydraulic pressure of the power hydraulic pressure source 64 decreases due to an abnormality in the electrical system, a decrease in the hydraulic pressure in the small-diameter side chamber 112 is prevented.

  The input-side check valve 99 is a bypass passage 136 serving as a movable portion bypass passage that connects the master passage 74 and the output side of the mechanical movable portion 98 (or the small-diameter side chamber 112) by bypassing the mechanical movable portion 98. It is provided in the middle. The bypass passage 136 can also be considered as a passage connecting the master passage 74 and the common passage 94 by bypassing the mechanical movable portion 98. The input-side check valve 99 allows the flow of hydraulic fluid from the master passage 74 to the output side of the mechanical movable unit 98 and blocks the reverse flow, and has a valve opening pressure of a set pressure. is there. The set pressure is a value determined based on a hydraulic pressure difference caused by a difference in height between the master reservoir 78 and the brake cylinder 42 (the master reservoir 78 is above the brake cylinder 42 in the vertical direction). The set pressure can be referred to as a height difference set pressure.

  When the brake pedal 60 is not operated, the pressurizing chamber 72 of the master cylinder 62 is communicated with the master reservoir 78 and is at almost atmospheric pressure. Further, the hydraulic pressure of the brake cylinder 42 is almost atmospheric pressure, but there is a hydraulic pressure difference due to the difference in height between them. On the other hand, if the valve opening pressure of the input-side check valve 99 is determined based on the hydraulic pressure difference due to the height difference, the hydraulic fluid from the master reservoir 78 is prevented from flowing out when the brake pedal 60 is not operated. Therefore, even if there is a leak around the brake cylinder 42, the flow of hydraulic fluid from the master reservoir 78 toward the brake cylinder 42 can be prevented. Further, when the brake pedal 60 is operated (the operation is performed so that the hydraulic brakes 40 and 50 are in an applied state and is usually a stepping operation), and the hydraulic pressure in the pressurizing chamber 72 is increased, the input is performed. The differential pressure before and after the side check valve 99 (the value obtained by subtracting the fluid pressure on the common passage side from the fluid pressure on the master cylinder side) is larger than the set pressure corresponding to the elevation difference, and the input side check valve 99 is switched to the open state. It is done. Thereby, the flow of hydraulic fluid from the master cylinder 62 toward the brake cylinder is allowed.

  The input-side check valve 99 can have, for example, the structure shown in FIG. For example, as shown in FIG. 4 (a), a cup seal type check valve 99x is used, as shown in FIG. 4 (b), a ball type check valve 99y is used, or as shown in FIG. 4 (c). Thus, the magnetic check valve 99z can be used.

  4A, the check valve 99x includes a housing 140 fixedly provided in the bypass passage 136, and an annular seal member 142 supported by the housing 140. The seal member 142 is formed of a material that is easily elastically deformed, such as rubber, and has a shape that is easily bent in the direction of the arrow X and hardly bent in the opposite direction. In the present embodiment, the master passage 74 is connected to the upstream side of the arrow X, and the common passage 94 is connected to the downstream side. The seal member 142 does not bend when the differential pressure before and after (the value obtained by subtracting the hydraulic pressure of the common passage 94 from the hydraulic pressure of the master passage 74) is equal to or lower than the set pressure corresponding to the elevation difference. The check valve 99x is in a closed state, and the outflow of hydraulic fluid from the master reservoir 78 is prevented. When the front-rear differential pressure becomes larger than the height difference setting pressure, the seal member 142 is bent. The check valve 99x is switched to the open state, and the outflow from the master cylinder 62 is allowed. Note that the flow of hydraulic fluid in the reverse direction, that is, from the common passage 94 toward the master passage 74 is blocked.

  As shown in FIGS. 4B to 4I, the check valve 99y includes (a) a housing 142, (b) a valve seat 143 formed on the housing 142, and (c) a valve seat 143. It is a seating valve including a valve element 144 that can be approached and separated. In the check valve 99y, the valve element 144 has a spherical shape and no spring is provided. Further, as shown in FIGS. 4B to 4I, a retaining portion 145 is provided on the opposite side of the housing 142 from the side on which the valve seat 143 is provided. In this embodiment, the check valve 99y is disposed in a posture in which the axis L of the check valve 99y is inclined by an angle θ with respect to the horizontal line H, as shown in FIGS. The master passage 74 is connected to the downstream side of the axial component Ga (= mgsin θ) of the gravity G (= mg) acting on the valve element 144, and the common passage 94 is connected to the upstream side.

  In the check valve 99y, when the differential pressure before and after (the value obtained by subtracting the hydraulic pressure of the small-diameter side chamber 112 from the hydraulic pressure of the master reservoir 78) is equal to or smaller than the magnitude corresponding to the component Ga, the valve element 144 is 143 is in a seated state. The check valve 99y is closed, and the flow of hydraulic fluid from the master reservoir 78 to the output side of the pressure increasing device 98 is blocked. When the front-rear differential pressure becomes larger than the magnitude corresponding to the component Ga, the valve element 144 is separated from the valve seat 143, the check valve 99y is opened, and the working fluid from the master passage 74 toward the common passage 94 is opened. Flow is allowed. In this case, since the retaining portion 145 is provided, the valve element 144 is prevented from coming out of the check valve 99y. Further, when a flow of hydraulic fluid from the common passage 94 toward the master passage 74 is generated, a suction force is applied, and the valve element 144 is moved toward the valve seat 143 and is seated. In other words, the check valve 99y is provided in a posture in which the component Ga becomes a force corresponding to the height difference setting pressure (in a posture inclined by the angle θ).

In FIG. 4C, the check valve 99z includes a valve element 146 and a valve seat 147, but does not have a spring. Further, at least one of the valve element 146 and the valve seat 147 is a permanent magnet made of a ferromagnetic material, and is brought close to each other by a magnetic force. The magnetic force (attraction force) acting between the valve element 146 and the valve seat 147 has a magnitude corresponding to the height difference setting pressure. The master passage 74 is connected to the upstream side of the arrow Z so that a differential pressure between the hydraulic pressure of the master passage 74 and the hydraulic pressure of the common passage 94 acts in the direction opposite to the magnetic force, that is, the common passage on the opposite side. 94 is connected. When the front-rear differential pressure is equal to or lower than the set pressure corresponding to the height difference, the check valve 99z is in a closed state, and the outflow of hydraulic fluid from the master reservoir 78 is prevented. When the front-rear differential pressure becomes larger than the height difference setting pressure, the valve element 146 moves away from the valve seat 147 against the magnetic force, and the check valve 99z is switched to the open state. Thereby, the flow of hydraulic fluid from the master passage 74 toward the common passage 96 is allowed. In the check valve 99z, a retaining portion (not shown) can be provided.
In this embodiment, the bypass passage 136 and the piston internal passage 129 constitute the pressure booster internal passage, the input side check valves 99x, 99y, 99z, etc. constitute the first check valve, and the piston internal reverse passage. A stop valve 130 constitutes a second check valve.

  An input side shut-off valve 148 is provided between the master passage 74 and the mechanical pressure booster 96. The input side shut-off valve 148 is a normally open electromagnetic on-off valve that is open when no current is supplied to the solenoid coil (hereinafter abbreviated as current to the solenoid).

  On the other hand, the brake cylinders 42FL and FR of the left and right front wheels 2 and 4 and the brake cylinders 52RL and RR of the left and right rear wheels 46 and 48 have individual passages 150FL, FR, RL, and RR as the brake side passage and the individual brake side passage, respectively. To the common passage 94. The individual passages 150FL, FR, RL, RR are provided with holding valves (SHij: i = F, R, j = L, R) 153FL, FR, RL, RR, and brake cylinders 42FL, FR, 52RL, respectively. , 52RR and the reservoir 78 are provided with pressure reducing valves (SRij: i = F, R, j = L, R) 156FL, FR, RL, RR, respectively. In this embodiment, the holding valves 153FL and FR provided corresponding to the left and right front wheels 2 and 4 are normally open electromagnetic on-off valves that are open when no current is supplied to the solenoid. , 48 are normally closed electromagnetic on-off valves that are closed when no current is supplied to the solenoids. Further, the pressure reducing valves 156FL, FR provided corresponding to the left and right front wheels 2, 4 are normally closed electromagnetic on-off valves that are closed when no current is supplied to the solenoid, and correspond to the left and right rear wheels 46, 48. The pressure reducing valves 156RL and RR provided in this manner are normally open electromagnetic on-off valves that are open when no current is supplied to the solenoid.

  In addition to the brake cylinders 42 and 52, a power hydraulic pressure source 64 and a mechanical pressure booster 96 are connected to the common passage 94. The power hydraulic pressure source 64 is connected to the common passage 94 via the power hydraulic pressure passage 170. The power hydraulic pressure passage 170 is provided with a pressure-increasing linear control valve (SLA) 172. The pressure-increasing linear control valve 172 is a normally closed electromagnetic on-off valve that is closed when no current is supplied to the solenoid, and the hydraulic pressure in the common passage 94 is controlled by continuously controlling the magnitude of the current supplied to the solenoid. Can be continuously controlled.

  As shown in FIG. 3, the pressure-increasing linear control valve 172 includes a seating valve including a valve element 180 and a valve seat 182, a spring 184, and a solenoid (including a coil and a plunger) 186. The urging force F <b> 2 acts in a direction in which the valve element 180 approaches the valve seat 182, and an electromagnetic driving force F <b> 1 acts in a direction in which the valve element 180 is separated from the valve seat 182 when current is supplied to the solenoid 186. Further, in the pressure-increasing linear control valve 172, a differential pressure acting force F3 corresponding to the differential pressure between the power hydraulic pressure source 64 and the common passage 94 acts in a direction to separate the valve element 180 from the valve seat 182 (F1 + F3: F2). By controlling the current supplied to the solenoid 186, the differential pressure acting force F3 is controlled, and the hydraulic pressure in the power hydraulic pressure passage 170 is controlled. The pressure-increasing linear control valve 172 can also be referred to as an output hydraulic pressure control valve that controls the output hydraulic pressure of the power hydraulic pressure source 64. Note that, when the pressure reduction control of the common passage 94 is performed, at least one pressure reduction valve 156 is opened and closed when the holding valve 153 is open. In the present embodiment, the power hydraulic pressure control device is configured by at least one of the pressure-increasing linear control valve 172 and the pressure-reducing valve 156.

  The mechanical pressure booster 96 is connected to the common passage 94 via the servo pressure passage 190. The servo pressure passage 190 is provided with an output side cutoff valve (SREG) 192 as a pressure booster cutoff valve. The output-side shut-off valve 192 is a normally-open electromagnetic on-off valve that is open when no current is supplied to the solenoid.

  On the other hand, the master passages 74 and 76 are connected to the downstream sides of the holding valves 153FL and FR of the individual passages 150FL and FR of the left and right front wheels 2 and 4, respectively. That is, the master passages 74 and 76 bypass the mechanical pressure intensifier 96 and the common passage 94, and directly connect the pressurizing chambers 72 and 70 to the brake cylinders 42 of the left and right front wheels 2 and 4 ( The master passages 74 and 76 can be called direct connection type manual passages). Master cutoff valves (SMCFL, FR) 194FL, FR as manual cutoff valves are provided in the middle of the master passages 74, 76, respectively. The master shut-off valves 194FL and FR are normally closed electromagnetic on-off valves that are closed when no current is supplied to the solenoid. Further, the stroke simulator 200 is connected to the master passage 74 via a simulator control valve 202. The simulator control valve 202 is a normally closed electromagnetic on-off valve.

  As described above, in this embodiment, the hydraulic pressure is increased by the pump device 65, the pressure-increasing linear control valve 172, the master cutoff valve 194, the holding valve 153, the pressure reducing valve 156, the input side cutoff valve 148, the output side cutoff valve 192, and the like. A control unit 54 is configured. The hydraulic pressure control unit 54 is controlled based on a command from the brake ECU 56. As shown in FIG. 1, the brake ECU 56 mainly includes a computer including an execution unit, an input / output unit, a storage unit, and the like. The input / output unit includes a brake switch 218, a stroke sensor 220, a master cylinder pressure sensor. 222, an accumulator pressure sensor 224, a brake cylinder pressure sensor 226, a level warning 228, a wheel speed sensor 230, an ignition switch 234, and the like, and a hydraulic pressure control unit 54 and the like are connected.

The brake switch 218 is a switch that turns from OFF to ON when the brake pedal 60 is operated.
The stroke sensor 220 detects an operation stroke (STK) of the brake pedal 60. In this embodiment, two sensors are provided, and similarly, an operation stroke of the brake pedal 60 is detected. Thus, since two stroke sensors 220 are provided, even if one breaks down, the operation stroke can be detected by the other.
The master cylinder pressure sensor 222 detects the hydraulic pressure (PMCFL) in the pressurizing chamber 72 of the master cylinder 62, and is provided in the master passage 74 in this embodiment.

The accumulator pressure sensor 224 detects the pressure (PACC) of the hydraulic fluid stored in the accumulator 66.
The brake cylinder pressure sensor 226 detects the hydraulic pressure (PWC) of the brake cylinders 42 and 52 and is provided in the common passage 94. When the holding valve 153 is in the open state, the brake cylinders 42 and 52 and the common passage 94 are communicated with each other, so that the hydraulic pressure in the common passage 94 can be made the hydraulic pressure in the brake cylinders 42 and 52.
The level warning 228 is a switch that is turned on when the hydraulic fluid stored in the master reservoir 78 is less than or equal to a predetermined set amount. In the present embodiment, when the amount of the hydraulic fluid stored in any one of the three storage chambers 80, 82, 84 becomes equal to or less than the set amount, it is turned ON.
Wheel speed sensors 230 are provided corresponding to the left and right front wheels 2, 4 and the left and right rear wheels 46, 48, respectively, and detect the rotational speed of the wheels. Further, the traveling speed of the vehicle is acquired based on the rotational speed of the four wheels.
The ignition switch (IGSW) 234 is a main switch of the vehicle.
Various programs, tables, and the like are stored in the storage unit.

<Operation in hydraulic brake system>
In the present embodiment, the supply state of the hydraulic pressure to the brake cylinders 42 and 52 is controlled in each of the case where there is a possibility of leakage, the possibility of leakage, and the case where the control system is abnormal.
The supply state control program represented by the flowchart of FIG. 5 is executed at predetermined time intervals.
In step 1 (hereinafter abbreviated as S1; the same applies to other steps), it is determined whether or not there is a braking request. When the brake switch 218 is ON, or when there is a request for operating the automatic brake, it is determined that there is a braking request, and the determination is YES. The automatic brake may be operated in traction control, vehicle stability control, inter-vehicle distance control, and collision avoidance control. When these control start conditions are satisfied, a braking request may be made.
When there is a braking request, in S2 and S3, a determination result as to whether there is a possibility of liquid leakage or whether the control system is abnormal is read.

The presence or absence of the possibility of liquid leakage does not matter whether the possibility of liquid leakage is high or low and the amount of liquid leakage. Therefore, there is a possibility that the possibility of liquid leakage is very low, or even if the amount of leakage is very small, it cannot be determined unless it is liquid leakage. Therefore, even if it is detected that there is a possibility of liquid leakage, the liquid leakage may not actually occur {the conditions (b) to (e) described later are caused by causes other than liquid leakage. May be met}.
For example, when (a) the level warning switch 228 is ON, (b) when a brake operation is performed, a predetermined relationship is established between the stroke of the brake pedal 60 and the hydraulic pressure of the master cylinder 62. In this case, it is assumed that there is no liquid leakage. However, if the hydraulic pressure in the master cylinder 62 is small relative to the stroke, there is a possibility of liquid leakage. Further, (c) when the detection value of the accumulator pressure sensor 224 does not exceed the liquid leakage determination threshold value even if the pump 92 continues to operate for a predetermined set time or longer, (d) regenerative cooperative control is performed. If the detected value of the brake cylinder pressure sensor 226 is smaller than the detected value of the master cylinder pressure sensor 222, (e) if it is detected that there is a possibility of liquid leakage during the previous brake operation ( In the case where the hydraulic pressure of the master cylinder 62 is supplied to the brake cylinders 42 of the left and right front wheels 2, 4 and the pump pressure is supplied to the brake cylinders 52 of the left and right rear wheels 46, 48), there is a possibility of liquid leakage. It is said.

The abnormality of the control system means a state in which the hydraulic pressure of the brake cylinders 42 and 52 or the hydraulic pressure of the common passage 94 cannot be controlled using the hydraulic pressure of the power type hydraulic pressure source 64.
For example, (i) When an electromagnetic on-off valve or the like cannot be operated as commanded {an electromagnetic on-off valve such as a pressure increasing linear control valve 172 (for example, a holding valve 153, a pressure reducing valve 156, a master cutoff valve 194, an output side cutoff Valve 192 etc.) is disconnected, etc.}, (ii) when a detection value necessary for controlling the hydraulic pressure of the brake cylinders 42 and 52 cannot be obtained (including cases where it cannot be obtained accurately) [
Each sensor (brake switch 218, stroke sensor 220, master cylinder pressure sensor 222, accumulator pressure sensor 224, brake cylinder pressure sensor 226, wheel speed sensor 230, etc.) is disconnected, etc.], (iii) each electromagnetic open / close When power (also referred to as electrical energy or current) cannot be supplied to valves, sensors, etc. (such as when the power supply of the power storage device 22 or the like is broken or the wiring is broken), (iv) This corresponds to a case where high-pressure hydraulic fluid cannot be supplied from the pressure source 64 {for example, an abnormality of the pump motor 92, a case where electric power cannot be supplied to the pump motor 92 (including a case caused by an abnormality of the power source), etc.}.

When both determinations of S2 and S3 are NO and the hydraulic brake system is normal (in this embodiment, the control system is normal and there is no possibility of liquid leakage). In S4, normal control is performed. The output hydraulic pressure of the power hydraulic pressure source 64 is controlled by the pressure-increasing linear control valve 172, and the power control pressure is supplied to the common passage 94 and supplied to the brake cylinders 42 and 52.
If the control system is abnormal, the determination in S3 is YES, and in S5, no current is supplied to the solenoids of all the valves, thereby returning the original position. Further, the pump motor 92 is kept in a stopped state.
If it is detected that there is a possibility of liquid leakage, the determination in S2 is NO, and in S6, the hydraulic pressure of the master cylinder 62 is supplied to the brake cylinders 42 of the left and right front wheels 2, 4, and the left and right rear wheels 46, The output hydraulic pressure of the power type hydraulic pressure source 64 is controlled and supplied to the 48 brake cylinders 52. Since it is rare that both the abnormality of the control system and the possibility of liquid leakage occur, the control system is normal even if there is a possibility of liquid leakage, the control of each valve, the drive of the pump motor 92 Is considered possible.
In the present embodiment, the automatic brake is not operated when the control system is abnormal or when there is a possibility of liquid leakage.

1) When the system is normal As shown in FIG. 6, the hydraulic pressure of the power hydraulic pressure source 64 is controlled in the brake cylinders 42, 52 of the front, rear, left and right four wheels 2, 4, 46, 48 (control). In principle, regenerative cooperative control is performed.
In the regenerative cooperative control, the total braking torque, which is the sum of the regenerative braking torque applied to the driving wheels 2 and 4 and the friction braking torque applied to both the driving wheels 2 and 4 and the driven wheels 46 and 48, is the total required braking torque. The control is performed as follows.
The total required braking torque is acquired based on detection values of the stroke sensor 220 and the master cylinder pressure sensor 222 (braking torque requested by the driver), or acquired based on the running state of the vehicle (traction control). Braking torque necessary for vehicle stability control). Then, the information supplied from the hybrid ECU 58 (the power generation side upper limit value that is the upper limit value of the regenerative braking torque determined based on the rotation speed of the electric motor 20, the power storage that is the upper limit value determined based on the charging capacity of the power storage device 22, etc. Side upper limit value) and the total required braking torque (requested value) described above are determined as the required regenerative braking torque, and information representing the required regenerative braking torque is supplied to the hybrid ECU 58.
Hybrid ECU 58 outputs information representing the required regenerative braking torque to motor ECU 28. The motor ECU 28 outputs a control command to the power converter 26 so that the braking torque applied to the left and right front wheels 2 and 4 by the electric motor 20 becomes the required regenerative braking torque. The electric motor 20 is controlled by the power converter 26.
Information representing the operating state such as the actual rotational speed of the electric motor 20 is supplied from the motor ECU 28 to the hybrid ECU 58. The hybrid ECU 58 obtains the actual regenerative braking torque actually obtained based on the actual operating state of the electric motor 20, and outputs information representing the actual regenerative braking torque value to the brake ECU 56.
The brake ECU 56 determines the required hydraulic braking torque based on a value obtained by subtracting the actual regenerative braking torque from the total required braking torque, so that the brake cylinder hydraulic pressure approaches the target hydraulic pressure corresponding to the required hydraulic braking torque. The pressure increasing linear control valve 172, the pressure reducing valve 156 and the like are controlled.

  In regenerative cooperative control, in principle, the holding valves 153FL, FR, RL, RR of the front, rear, left and right wheels 2, 4, 46, 48 are all opened, and the pressure reducing valves 156FL, FR, RL, RR are all closed. State. Further, the master cutoff valves 194FL and FR are closed, the simulator control valve 202 is opened, the input side cutoff valve 148 is closed, and the output side cutoff valve 192 is closed. With the common passage 94 cut off from the mechanical pressure booster 96 and the brake cylinders 42FL and FR of the left and right front wheels 2 and 4 cut off from the master cylinder 62, the hydraulic pressure is controlled by the pressure boost linear control valve 172. The output hydraulic pressure of the source 64 is controlled, and the power control pressure is supplied to the common passage 94 and supplied to the four-wheel brake cylinders 42 and 52 in common. Note that when the hydraulic pressure in the common passage 94 is decreased, one or more of the pressure reducing valves 156FL, FR, RL, and RR are controlled.

Thus, in this embodiment, the input side shut-off valve 148 is closed during normal operation.
Assume that the input side shut-off valve 148 is in an open state.
Since the output side shut-off valve 192 is in a closed state, the mechanical pressure intensifier 96 is in principle inoperative. However, the stepped piston 104 is allowed to advance within a range in which the sum of the volume of the high-pressure chamber 114, the volume of the small-diameter side chamber 112, and the volume of the large-diameter side chamber 110 is kept substantially constant. On the other hand, since the simulator control valve 202 is in the open state, the stroke simulator 200 is activated when the hydraulic pressure in the master passage 74 becomes larger than the operation start pressure of the stroke simulator 200. In this embodiment, the operation of the stroke simulator 200 is performed. The start pressure is smaller than the operation start pressure of the mechanical movable unit 98.
When the brake pedal 60 is operated and the hydraulic pressure in the master passage 74 becomes larger than the operation start pressure of the stroke simulator 200, the stroke simulator 200 is activated and the brake pedal 60 is allowed to advance. Thereafter, when the pressure exceeds the operation start pressure of the mechanical movable portion 98, the stepped piston 104 is moved forward, whereby the brake pedal 60 enters, and the driver feels uncomfortable.
On the other hand, in this embodiment, the input side shut-off valve 148 is closed. As a result, the brake pedal 60 is allowed to advance with the operation of the stroke simulator 200. Sudden entry is suppressed, and the driver's uncomfortable feeling can be reduced.
Further, by closing the input side shut-off valve 148, it is possible to reduce vibration, reduce operating noise, and the like.
The operation start pressure of the stroke simulator 200 is a value determined by a set load of the spring, a sliding resistance such as friction between the piston and the housing, and when the hydraulic pressure acting on the piston becomes larger than the operation start pressure, Movement is allowed. The operation start pressure is determined by the spring set load, frictional force, and the like.
The operation start pressure of the mechanical movable portion 98 is the same, and is a value determined by a set load of the spring 126, a sliding resistance such as a frictional force acting between the stepped piston 104 and the housing 102, and the like.

In this state, when the slip of the wheels 2, 4, 46, 48 becomes excessive and the antilock control start condition is satisfied, the holding valve 153 and the pressure reducing valve 156 are opened and closed independently, and the brake cylinders 42 are opened and closed. , 52 is controlled. The slip state of the front, rear, left and right wheels 2, 4, 46, 48 is set to an appropriate state.
Further, when the hydraulic brake system is mounted on a vehicle that does not include the electric drive device 8, in a vehicle in which regenerative cooperative control is not performed, when the system is normal, the total required braking torque and the hydraulic braking are performed. The pressure-increasing linear control valve 172 and the like are controlled so that the torque becomes equal.
The first input side shut-off valve control device and the second input side shut-off valve control device are configured by a portion that stores S4 of the hydraulic pressure supply state control program of the brake ECU 56, a portion that executes the program, and the like. Moreover, these can also be called a power control pressure supply part.
Further, the part for storing S4 of the brake ECU 56, the part for executing, the power hydraulic pressure source 64, the pressure-increasing linear control valve 172, the common passage 94, the individual passage 150, the brake cylinders 42, 52, etc. constitute a power hydraulic system. Is done.

2) When the control system is abnormal As shown in FIGS. 7 and 8, each valve is returned to its original position.
The pressure-increasing linear control valve 172 is closed when no current is supplied to the solenoid 186, and the power hydraulic pressure source 64 is shut off from the common passage 94.
In addition, since the master shut-off valve 194 is closed, the brake cylinder 42 is shut off from the master cylinder 62.
Further, since the input side shut-off valve 148 and the output side shut-off valve 192 are opened, the mechanical pressure booster 96 is communicated with the master passage 74 and the common passage 94.
Further, since the holding valves 153RL and RR are in the closed state and the holding valves 153FL and FR are in the open state, the brake cylinders 42FL and FR of the left and right front wheels 2 and 4 are communicated with the common passage 94, and the left and right rear wheels 46, The 48 brake cylinders 52RL and RR are shut off.
As described above, when the control system is abnormal, the brake cylinders 42FL and FR of the left and right front wheels 2 and 4 are actuated, so that the yaw moment can be hardly generated when the center of gravity of the vehicle is substantially at the center in the left and right direction. .

2-1) When the hydraulic pressure in the large-diameter side chamber 110 is equal to or less than the operation start pressure of the mechanical movable unit 98 As shown in FIG. In this case, the hydraulic pressure in the pressurizing chamber 72 (referred to as a master hydraulic pressure as a manual hydraulic pressure) is supplied to the common passage 94 via the master passage 74, the bypass passage 136, and the servo pressure passage 190, and the left and right front wheels 2 are supplied. , 4 are supplied to the brake cylinder 42.
Since the valve opening pressure of the input-side check valve 99 is very small, it becomes possible to quickly supply the hydraulic fluid to the brake cylinder 42 in accordance with the operation of the brake pedal 60, and to reduce the delay in the effect of the hydraulic brake 40. be able to.

2-2) When the hydraulic pressure in the large-diameter side chamber 110 is higher than the operation start pressure of the mechanical movable unit 98 2-2-1) When the hydraulic pressure of the hydraulic fluid stored in the accumulator 66 is higher than the allowable pressure Even when the operation of 65 is stopped, if the hydraulic pressure of the hydraulic fluid stored in the accumulator 66 is higher than the set pressure, the operation of the mechanical movable unit 98 is permitted. The set pressure is such a size that the mechanical type capable portion 98 can be operated, in other words, a size capable of supplying the hydraulic pressure to the high pressure chamber 114 of the mechanical type movable portion 98, and the high pressure chamber 114 (the small diameter side chamber 112). ) Can be considered to be larger than the hydraulic pressure. The set pressure can be referred to as an operation permission pressure.
As indicated by the solid line in FIG. 8, the stepped piston 104 is advanced by the hydraulic pressure in the large-diameter side chamber 110, contacts the valve opening member 125, and the high-pressure supply valve 116 is switched to the open state. The small-diameter side chamber 112 is shut off from the large-diameter side chamber 110, and high-pressure hydraulic fluid is supplied from the accumulator 66 to the high-pressure chamber 114 through the high-pressure side check valve 100 and then supplied to the small-diameter side chamber 112. The hydraulic pressure in the small-diameter side chamber 112 is made higher than the hydraulic pressure in the master cylinder 62, supplied to the common passage 94 through the output-side shut-off valve 192 in the open state, and brakes for the left and right front wheels 2 and 4 through the holding valves 153FL and FR. It is supplied to the cylinders 42FL and 42RR.
The hydraulic pressure Pout of the small-diameter side chamber 112 is assumed to be equal to the hydraulic pressure of the master cylinder 62 (the hydraulic pressure of the large-diameter side chamber 110) Pin and the large-diameter portion side of the stepped piston 104, assuming that the operation start pressure is zero. A value Pout = Pin · (Sin / Sout) obtained by multiplying the ratio (Sin / Sout) of the pressure receiving area Sin and the pressure receiving area Sout on the small diameter portion side
It becomes. This hydraulic pressure Pout is referred to as servo pressure. From this, the small-diameter side chamber 112 can be called a control pressure chamber.
The mechanical pressure increasing device 96 is actuated by the hydraulic pressure in the pressurizing chamber 72, and therefore can be considered as a manual hydraulic pressure source in a broad sense. In the present embodiment, the pressurizing chamber 72 corresponds to a manual pressure source connected to a pressure booster as a first manual hydraulic pressure source, and the mechanical pressure booster 96 corresponds to a second manual hydraulic pressure source. .

2-2-2) When the hydraulic pressure of the hydraulic fluid stored in the accumulator 66 is equal to or lower than the allowable pressure for operation When the hydraulic pressure of the hydraulic fluid stored in the accumulator 66 is equal to or lower than the allowable pressure of operation, FIG. Similarly to the state shown, the master hydraulic pressure in the pressurizing chamber 72 of the master cylinder 62 is supplied to the brake cylinder 42 of the left and right front wheels 2, 4 through the master passage 74, the bypass passage 136, the servo pressure passage 190, and the common passage 94. The
On the other hand, when the hydraulic pressure of the hydraulic fluid stored in the accumulator 66 is lowered by the operation of the mechanical movable unit 98 and becomes lower than the operation permission pressure, the hydraulic fluid is not supplied from the accumulator 66 to the high-pressure chamber 114. Thereby, the mechanical movable part 98 becomes difficult to operate. For example, when a pumping brake operation is performed, the amount of hydraulic fluid consumed by the accumulator 66 increases, and the accumulator pressure becomes lower than the operation permission pressure. The forward movement of the stepped piston 104 is prevented (it is advanced until it abuts against the stopper, and then the forward movement is considered to be blocked), and the hydraulic pressure in the small-diameter side chamber 112 does not increase any further, and the mechanical type The movable part 98 cannot exhibit the boosting function. When the hydraulic pressure in the pressurizing chamber 72 becomes higher than the hydraulic pressure in the small-diameter side chamber 112, the hydraulic pressure in the pressurizing chamber 72 of the master cylinder 62 becomes the bypass passage 136, servo pressure, as shown by the broken line in FIG. It is supplied to the common passage 94 via the passage 190. The hydraulic pressure in the pressurizing chamber 72 of the master cylinder 62 is supplied to the brake cylinders 42FL and 42FR of the left and right front wheels 2 and 4 without being boosted.

Further, since the holding valves 153RL and RR are in the closed state, the hydraulic pressure of the mechanical movable unit 98 is not supplied to the brake cylinders 52RL and 52RR of the left and right rear wheels 46 and 48. As a result, liquid shortage is suppressed, and insufficient pressure increase of the brake cylinders 42FL and FR of the left and right front wheels 2 and 4 can be suppressed.
Furthermore, the volume of the pressurizing chamber 72 in the master cylinder 62 can be increased. If the volume of the pressurizing chamber 72 is increased, it is possible to avoid a shortage of fluid even when hydraulic fluid is supplied to both the brake cylinders 42FL and FR of the left and right front wheels 2 and 4. In this case, the stroke of the driver's brake pedal 60 may be increased.
In the present embodiment, the holding valves 153FL, FR are normally open valves, the input side shut-off valve 148, the output side shut-off valve 192 are normally open valves, a part that stores S5 of the brake ECU 56, and a part that executes it Thus, the servo pressure supply device for abnormal time is configured. In addition, the servo pressure supply unit is configured by a part that stores S5 of the brake ECU 56, a part that executes S5, and the like.

3) When it is detected that there is a possibility of liquid leakage As shown in FIG. 9, the holding valves 153FL, FR of the left and right front wheels 2, 4 are closed, and the holding valves 153RL, RR of the left and right rear wheels 46, 48 are closed. Is opened. Further, the master cutoff valves 194FL and FR are opened, and the input side cutoff valve 148, the output side cutoff valve 192, and the simulator control valve 202 are closed. Further, all the pressure reducing valves 156 are closed.
The hydraulic pressures in the pressurizing chambers 72 and 70 of the master cylinder 62 are respectively supplied to the brake cylinders 42FL and FR of the left and right front wheels 2 and 4, and the pump devices are supplied to the brake cylinders 52RL and RR of the left and right rear wheels 46 and 48, respectively. A hydraulic pressure of 65 is controlled and supplied.
In this way, the holding valves 153FL, FR of the left and right front wheels 2, 4 are shut off, so that the brake cylinders 42FL, FR of the left and right front wheels 2, 4 are independent from each other. Further, the brake cylinders 42FL, FR of the left and right front wheels 2, 4 and the brake cylinders 52RL, RR of the left and right rear wheels 46, 48 are blocked. The brake cylinders of the front wheels 2 and 4 and the rear wheels 46 and 48 are blocked from each other, and the brake cylinders of the left front wheel 2 and the right front wheel 4 are blocked from each other on the front wheel side. That is, (brake system 250FL including the brake cylinder 42FL of the left front wheel 2), (brake system 250FR including the brake cylinder 42FR of the right front wheel 4), (brake system 250R including the brake cylinders 52FL and RR of the left and right rear wheels 46 and 48) ) Are disconnected from each other. As a result, even if liquid leakage occurs in one of these three brake systems, the other brake systems can be prevented from being affected.
In this sense, the holding valves 153FL and FR have a function as a separation valve that separates the brake systems 250FR, FL, and R.

In this embodiment, the brake system 250FR includes a brake cylinder 42FR, a master passage 76, a pressurizing chamber 70, a storage chamber 80, etc., and the brake system 250FL includes the brake cylinder 42FL, the master passage 74, and the pressurizing chamber 72. The brake system 250R includes the brake cylinders 52RL and RR, the individual passages 150RL and RR, the power hydraulic pressure source 64, the storage chamber 84, and the like. Therefore, the fact that the brake systems 250FR, FL, R are made independent from each other means that the storage chambers 80, 82, 84 of the reservoir 78 are also made independent from each other.
In the present embodiment, a manual hydraulic pressure / power control pressure supply unit is configured by a part that stores S6 of the brake ECU 56, a part that executes S6, and the like.

  Further, even when there is no possibility of liquid leakage, the state shown in FIG. 9 can be obtained when the hydraulic pressure of the hydraulic fluid stored in the accumulator 66 is lower than the operation permission pressure. It is considered that the hydraulic pressure of the hydraulic fluid stored in the accumulator 66 is lower than the operation permission pressure due to an abnormality of the pump device 65 (control of the electromagnetic on-off valve is possible). It is assumed that there is an abnormality in the control system, and the state shown in FIGS. However, even when the state shown in FIGS. 7 and 8 is established, the mechanical movable portion 98 becomes inoperable, and as shown by the broken line in FIG. 8, the pressurizing chamber 72 of the master cylinder 62 is provided in the brake cylinders 42FL and FR. Is supplied. On the other hand, if the state is switched to the state shown in FIG. 9, the pressurizing chambers 72 and 70 are communicated with the brake cylinders 42FL and FR, respectively, so that insufficient hydraulic pressure can be suppressed. If the hydraulic pressure in the brake cylinders 52RL and RR of the left and right rear wheels 46 and 48 cannot be effectively controlled due to the low hydraulic pressure of the hydraulic fluid stored in the accumulator 66, the pressure-increasing linear control is performed. It is desirable that the valve 172 be closed and the holding valves 153RL and RR be closed.

4) When the hydraulic brake is released When the brake operation is released, the current is not supplied to the solenoids of all the valves, thereby returning the original position of FIG. In the mechanical pressure increasing device 96, the stepped piston 104 is at the retracted end (or returned to the retracted end). The stepped piston 104 is separated from the valve opening member 125, and the intra-piston communication path 129 is opened. The hydraulic pressures in the brake cylinders 42FL and FR of the left and right front wheels 2 and 4 are returned to the master cylinder 62 (master reservoir 78) through the in-piston communication passage 129 and the in-piston check valve 130. The hydraulic pressures in the brake cylinders 52RL and RR of the left and right rear wheels 46 and 48 are returned to the reservoir 78 via the pressure reducing valve 156.

5) Ignition switch 234 in OFF state By supplying current to the solenoids of all the valves, the original position in FIG. 2 is obtained.
a) As shown in FIG. 2, since the pressure-increasing linear control valve 172 is in the closed state, the power hydraulic pressure source 64 is cut off from the common passage 94. Therefore, even if there is a liquid leak on the downstream side (brake cylinders 42FL, FR) from the common passage 94, the hydraulic fluid is prevented from flowing out from the storage chamber 84 of the reservoir 78 through the power hydraulic pressure passage 170. The
b) Since the master shut-off valve 194 is in the closed state, even if liquid leaks around the brake cylinders 42FL and FR of the left and right front wheels 2 and 4, the reservoir passages 80 and 82 pass through the master passages 74 and 76. The hydraulic fluid is prevented from flowing out.
c) Since the input side check valve 99 and the in-piston check valve 130 are provided, even if there is a liquid leak downstream of the common passage 94, the mechanical pressure booster from the storage chamber 82 of the master reservoir 78 The outflow of hydraulic fluid through 96 can be prevented. Even if there is a liquid leak on the downstream side of the common passage 94, the hydraulic fluid is prevented from flowing out from the storage chamber 82 of the master reservoir 78 through the in-piston communication passage 129, and the input side check valve 99, The in-piston check valve 130 and the like constitute an outflow prevention device 260.

As described above, in this embodiment, when the ignition switch 234 is in the OFF state, even if there is a liquid leak on the downstream side of the common passage 94, the working fluid from the storage chambers 80, 82, 84 of the master reservoir 78 Can be prevented well. Thereby, the hydraulic brakes 40 and 50 can be operated satisfactorily.
In the present embodiment, the outflow prevention device 260 is configured by the input side check valve 99, the piston check valve 130, etc., but in addition, the master cutoff valve 194, the pressure-increasing linear control valve 172, the holding valves 153RL, RR. For example, outflow from the master reservoir 78 is prevented.

  As shown in FIG. 10, the outflow prevention device 270 is provided at an arbitrary position between the connection portion of the servo pressure passage 190 of the common passage 94 and the portion of the individual passage 150FR where the holding valve 153FR is provided. Other portions are the same as those in the first embodiment. Outflow prevention device 270 includes a first check valve 272 and a second check valve 274 provided in parallel with each other. The first check valve 272 is similar to the input-side check valve 99 of the first embodiment in that the valve opening pressure is set to a height difference setting pressure, and the second check valve 274 is the same as that of the first embodiment. Similar to the in-piston check valve 130, the flow of hydraulic fluid from the brake cylinder 42FR to the master reservoir 78 is allowed and the reverse flow is prevented. According to the outflow prevention device 270, when the operation operation of the brake pedal 60 is not performed, the outflow of hydraulic fluid toward the brake cylinder 42FR from the reservoir accommodation chamber 82 through the mechanical pressure intensifying device 96 can be prevented. it can. In particular, it is possible to prevent the hydraulic fluid from flowing out of the reservoir housing chamber 82 when liquid leaks around the brake cylinder 42FR of the right front wheel 4, and control when the hydraulic brakes 40, 50 are operated. Power shortage can be suppressed. In the mechanical pressure increasing device 96, an in-piston check valve is not required. Moreover, the magnitude | size of the valve opening pressure of the input side check valve 276 is not ask | required. The valve opening pressure of the input side check valve 276 can be set to a magnitude that is not related to the hydraulic pressure difference due to the height difference.

  As shown in FIG. 11, the outflow prevention device 280 can be provided between the small-diameter side chamber 112 of the servo pressure passage 190 and the connection portion of the bypass passage 136 inside the mechanical pressure booster 96. The outflow prevention device 280 includes a first check valve 282 and a second check valve 284 provided in parallel with each other as in the second embodiment. Other portions are the same as those in the first embodiment. According to the outflow prevention device 280, when the brake pedal 60 is not operated, the outflow of hydraulic fluid from the accommodation chamber 82 of the master reservoir 78 through the in-piston communication path 129 can be prevented. The outflow prevention device 280 may be provided in any of the servo pressure passages 190, may be provided on the downstream side of the bypass passage 136, and may further be provided on the downstream side (common passage side) of the output side shut-off valve 192.

Other examples

In addition, the structure of a brake circuit is not ask | required.
For example, a mechanical pressure booster 96 can be directly connected to the master passage 74. In other words, the input side shut-off valve 148 is not indispensable. In addition, it is not essential to provide an outflow prevention device. Furthermore, it is not essential that both the master shut-off valves 194FL and FR are normally closed valves, and at least one of them can be a normally open valve.
Further, at least one of the holding valves 153RL, RR of the left and right rear wheels 46, 48 can be a normally open electromagnetic on / off valve, and at least one of the corresponding pressure reducing valves 156RL, RR can be a normally closed electromagnetic on / off valve. In this embodiment, when the control system is abnormal, the output hydraulic pressure of the mechanical pressure booster 96 can be supplied to the three-wheel or four-wheel brake cylinders 42 and 52. The brake cylinder communicated with the mechanical pressure intensifier 96 when the control system is abnormal can be determined within a range where the hydraulic fluid can be supplied based on the volume of the pressurizing chamber 72 of the master cylinder 62 and the like. Further, when the volume of the master cylinder 62 is increased, the operation stroke of the driver's brake pedal 60 may increase or the reaction force may increase (a large operating force may be required). The volume of the master cylinder 62 can be appropriately designed in consideration of the operation feeling of the driver, the number of hydraulic brakes that are actuated when the control system is abnormal, and the like.

As shown in FIG. 12A, the holding valve 153RR1 corresponding to the brake cylinder 52RR of the right rear wheel 48, which is one of the left and right rear wheels 46, 48, is a normally open electromagnetic on-off valve, and the pressure reducing valve 156RR1. Can be a normally closed electromagnetic on-off valve. In this embodiment, when the control system is abnormal, the output hydraulic pressure of the mechanical pressure booster 96 is supplied to the brake cylinders 42FL, FR, 52RR of the left and right front wheels 2, 4, and the right rear wheel 48. As shown in FIG. 12 (b), in a vehicle in which the driver's seat is on the right side in the forward direction (the steering member 300 is on the right side in the forward direction), a so-called right-hand drive vehicle, In some cases, the center of gravity G1 of the entire vehicle including the driver or the like is located on the right side of the center in the left-right direction. Other portions are the same as those in the first embodiment. In this vehicle, the length rL of the arm from the center of gravity G1 to the contact point with the road surface of the left wheels 2, 46 is longer than the length rR of the arm to the contact point with the road surface of the right wheels 4, 48 (rL > RR). In this case, when the hydraulic pressure of the mechanical pressure booster 96 is supplied to the brake cylinders 42FL and FR of the left and right front wheels 2 and 4 when the control system is abnormal, the yaw moment γ in the left turn direction is increased. Works.
γ = rR · (F _FR ) −rL · (F _FL ) <0

In contrast, in this embodiment, when the control system is abnormal, the servo pressure, which is the hydraulic pressure of the mechanical pressure booster 96, is applied to the brake cylinders 42FL and FR of the left and right front wheels 2 and 4, and the brake cylinder of the right rear wheel 48. The hydraulic pressures of these three brake cylinders 42FL, FR, RR are substantially the same (P _FL = P _FR = P _RR ). Therefore, the sum of the braking force (force acting between the road surface and the tire) caused by the hydraulic pressure supplied to the brake cylinders 42FL and 52RL of the left wheels 2 and 46 (the brake cylinder 52RL of the left rear wheel 46 has no liquid) Pressure is not supplied) is smaller than the sum of the braking forces resulting from the hydraulic pressure supplied to the brake cylinders 42FR, RR of the right wheels 4, 48 (F _FL <F _FR + F _RR ).
And the absolute value of the yaw moment γ acting on this vehicle is
| Γ | = | rR · (F _FR + F _RR ) −rL · (F _FL ) |
However, since the arm rL is longer than the arm rR as described above, the absolute value of the acting yaw moment γ can be reduced.

  Thus, in this embodiment, when the control system is abnormal, the servo pressure of the mechanical pressure booster 96 is supplied to the three brake cylinders of the front, rear, left and right four wheels. The sum of the braking forces acting on 46 and the sum of the braking forces acting on the right wheels 4, 48 are not equal. However, when the servo pressure of the mechanical pressure booster 96 is at a position where the center of gravity G deviates from the center in the left-right direction of the vehicle, the sum of the braking forces on the short side of the arm from the center of gravity G is It is distributed so as to be larger than the sum of braking forces. Therefore, yaw moment can be made difficult to occur when the control system is abnormal. In this embodiment, manual operation is performed by the master cylinder 62, the mechanical pressure intensifier 96, the common passage 94, the individual passages 150FL, FR, RR, the normally open holding valves 153FL, FR, RR1, the brake cylinders 42FL, FR, 52RR, and the like. A hydraulic system is constructed. The manual hydraulic system includes a single hydraulic distribution unit. As described above, the output hydraulic pressure of the mechanical pressure booster 96 is a servo pressure, but it can be considered that the servo pressure is a manual hydraulic pressure in a broad sense.

  In the present embodiment, the in-piston check valve 130 and the input side shut-off valve 148 are not essential.

Further, in the hydraulic brake circuit shown in FIG. 13A, the holding valve 153RL2 corresponding to the brake cylinder 52RL of the left rear wheel 46 of the left and right rear wheels 46, 48 is normally opened, and the pressure reducing valve 156RL2 is It is a normally closed valve. In this embodiment, when the control system is abnormal, the servo pressure of the mechanical pressure booster 96 is supplied to the brake cylinders 42FL, FR, 52RL of the left and right front wheels 2, 4 and the left rear wheel 46. As shown in FIG. 13 (b), the driver's seat is on the left side in the forward direction (the steering member 302 is on the left side in the forward direction). The center of gravity G2 is located on the left side of the center in the left-right direction. Other portions are the same as those in the first embodiment.
In this embodiment, when the control system is abnormal, the absolute value of the yaw moment γ acting on the vehicle is
| Γ | = | rR (F _FR ) −rL (F _FL + F _RL ) |
It becomes. In this case, the sum of the braking forces acting on the right wheels 4, 48 is smaller than the sum of the braking forces acting on the left wheels 2, 46 {(F _FR ) <(F _FL + F _RL )}, and the right wheel from the center of gravity G2 Since the arm rR to the contact point with respect to the road surface 4, 48 is longer than the arm rL to the contact point of the left wheel 2, 46 (rR> rL), the absolute value of the acting yaw moment γ can be reduced. In this embodiment, manual operation is performed by a master cylinder 62, a mechanical pressure intensifier 96, a common passage 94, individual passages 150FL, FR, RL, normally open holding valves 153FL, FR, RL2, brake cylinders 42FL, FR, 52RR, and the like. A hydraulic system is constructed. The manual hydraulic system includes a single hydraulic distribution unit.

In the hydraulic brake circuit of FIG. 14A, the master cutoff valve 194FR3 corresponding to the brake cylinder 42FR of the right front wheel 4 is a normally open valve, and the holding valve 153FR3 is a normally closed valve. Further, the holding valve 153RR3 corresponding to the brake cylinder 52RR of the right rear wheel 48 is a normally open valve, and the pressure reducing valve 153RR3 is a normally closed valve. When the control system is abnormal, the master pressure is supplied to the brake cylinder 42FR of the right front wheel 4, and the servo of the mechanical pressure booster 96 is applied to the brake cylinders 42FL and 52RR of the diagonal wheels (left front wheel 2, right rear wheel 48). Pressure is supplied.
The yaw moment γ in the right turn direction acting on the vehicle with the driver's seat on the left side in the forward direction (the vehicle with the steering wheel 302 on the left side) is
γ = rR (F _FR + F _RR ) −rL (F _FL )
It becomes. In the above formula, the hydraulic pressure Pm of the master cylinder 62 is smaller than the servo pressure Pb of the mechanical pressure booster 96 (Pm <Pb). When the brake cylinder hydraulic pressure is the same, the braking force acting on the rear wheel is smaller than the braking force acting on the front wheel. Therefore, the sum of braking forces acting on the left wheels 2 and 46 and the sum of braking forces acting on the right wheels 4 and 8 are substantially the same.
(F _FL ) ≒ (F _FR + F _RR )

  On the other hand, since the length of the arm rR is longer than the length of the arm rL (rR> rL), in this embodiment, the yaw moment γ is a positive value (γ> 0). Therefore, as shown in FIG. 14 (b), when the control system is abnormal, the yaw moment in the right turning direction acts on the left-hand drive vehicle. The yaw moment that acts when the control system is abnormal is in the direction in which the vehicle deviates from the oncoming lane in an area where the left-hand drive vehicle travels on the right side according to regulations. As a result, for example, when the driver performs a correction operation, the safety of the vehicle can be improved as compared with the case where the yaw moment in the direction approaching the oncoming lane acts. In the present embodiment, the power hydraulic pressure source 64, the pressure-increasing linear control valve 172, the common passage 94. The individual passage 150, the holding valve 153, the brake cylinders 42, 52, etc. constitute a power hydraulic system, and the master cylinder 62, the mechanical pressure booster 96, the common passage 94, the individual passages 150FL, RR, the normally open holding valve 153FL3. , RR3, master passage 76, normally open master shut-off valve 194FL3, brake cylinders 42FL, FR, 52RR, etc. constitute a manual hydraulic system. The manual hydraulic system includes a mixed hydraulic distribution unit.

  This also has the same effect when the left-hand drive vehicle has the brake circuit shown in FIG.

In the hydraulic brake circuit shown in FIG. 15A, the master cutoff valve 194FL4 corresponding to the brake cylinder 42FL of the left front wheel 2 is a normally open valve, and the holding valve 153FL4 is a normally closed valve. Further, the holding valve 153RL4 corresponding to the left rear wheel 46 is a normally open valve, and the pressure reducing valve 153RL4 is a normally closed valve. When the control system is abnormal, the master pressure is supplied to the brake cylinder 42FL of the left front wheel 2, and the servo pressure of the mechanical pressure booster 96 is applied to the brake cylinders 42FR and 52RL of the diagonal wheels (the right front wheel 4 and the left rear wheel 46). Is supplied.
The yaw moment γ in the right turn direction acting on the vehicle whose driver's seat is on the right side in the forward direction (the vehicle on which the steering wheel 300 is on the right side) is
γ = rR (F _FR ) −rL (F _FL + F _RL )
It becomes. In the above equation, the sum of braking forces acting on the left wheels 2 and 46 and the sum of braking forces acting on the right wheels 4 and 8 are substantially the same.
(F _FR ) ≒ (F _FL + F _RL )

On the other hand, since the arm rL is longer than the arm rR (rL> rR), the yaw moment γ becomes a negative value (γ <0) as shown in FIG.
This yaw moment is in a direction in which the vehicle deviates from the oncoming lane in an area where the right-hand drive vehicle travels in the left lane by law. As a result, traveling safety when the control system is abnormal can be improved.
In this embodiment, the master cylinder 62, the mechanical pressure increasing device 96, the common passage 94, the individual passages 150FR and RL, the normally open holding valves 153FR4 and RL4, the master passage 76, the normally open master shut-off valve 194FR4 and the brake cylinder. 42FL, FR, 52RL, etc. constitute a manual hydraulic system. The manual hydraulic system includes a single hydraulic distribution unit.

  Further, when the control system is abnormal, the servo pressure can be supplied to the brake cylinders of the wheels that are diagonal to each other. For example, in the brake circuit shown in FIG. 14A, the master shut-off valve 194FR3 can be a normally closed valve. In the present embodiment, the servo pressure is supplied to the brake cylinders 42FL and 52RR of the left front wheel 2 and the right rear wheel 48. As shown in FIG. 14B, in a vehicle with the steering wheel 302 provided on the left side, the braking force applied to the right wheel (the one with the longer arm) is greater than the braking force applied to the left wheel (the one with the shorter arm). Therefore, the yaw moment can hardly be generated. Similarly, in the brake circuit shown in FIG. 15 (a), the master shut-off valve 194FL4 can be a normally closed valve. In the present embodiment, servo pressure is supplied to the brake cylinders 42FR and 52RL of the right front wheel 4 and the left rear wheel 46. As shown in FIG. 15B, in a vehicle with the steering wheel 300 provided on the right side, the braking force applied to the left wheel (the one with the longer arm) is greater than the braking force applied to the right wheel (the one with the shorter arm). Therefore, the yaw moment can hardly be generated.

  The hydraulic brake system may include a brake circuit shown in FIG. Other portions are the same as those in the first embodiment. In the hydraulic brake circuit shown in FIG. 16, the pressurizing chamber 72 of the master cylinder 62 is connected to a mechanical pressure booster 96 via a mechanical valve input passage 310. Further, since the mechanical pressure intensifier 96 is provided with a bypass passage 136, the pressurizing chamber 72 has a mechanical valve input passage 310, a bypass passage 136, a servo pressure passage 190, a common passage 94, and individual passages 150FL and 150FR. To the brake cylinders 42FL and FR. Therefore, the mechanical valve input passage 310, the bypass passage 136, the servo pressure passage 190, the common passage 94, the individual passage 150FL, FR, etc. are used as master passages (passages that do not bypass the mechanical pressure booster 96 and are not directly connected manual passages). 311) can be considered.

  Further, a high-pressure shut-off valve 312 is provided in series with the high-pressure check valve 100 in the high-pressure passage 132 between the mechanical pressure booster 96 and the power-type hydraulic pressure source 64. In this embodiment, the high-pressure shut-off valve 312 is provided on the power hydraulic pressure source 64 side from the high-pressure check valve 100, but the arrangement is not limited. In the open state of the high pressure shut-off valve 312, the function of the high pressure check valve 100 is exhibited. When the flow of hydraulic fluid from the mechanical pressure booster 96 to the power hydraulic pressure source 64 is blocked and the hydraulic pressure of the power hydraulic pressure source 64 is larger than the hydraulic pressure of the mechanical pressure booster 96, the power hydraulic fluid The flow of hydraulic fluid from the pressure source 64 to the mechanical pressure booster 96 is allowed. However, in the closed state of the high pressure shut-off valve 312, the function of the high pressure side check valve 100 is not exhibited. The inflow / outflow of the hydraulic fluid in the high pressure chamber 114 is blocked, and the operation of the mechanical pressure intensifier 96 is blocked.

  Further, an input side shut-off valve 148 is provided in the middle of the mechanical valve input passage 310 as in the first embodiment. The input side shut-off valve 148 is closed when the master cylinder 62 is connected to the brake cylinder. In order to prevent the inflow of hydraulic fluid, it can be considered to correspond to a master cutoff valve. The input side shut-off valve 148 is provided in the non-directly connected manual passage and is a normally open valve. In this embodiment, the pressure-reducing linear control valve 316 is provided between the common passage 94 and the reservoir 78. The pressure-reducing linear control valve 316 has substantially the same structure as the pressure-increasing linear control valve 172 shown in FIG. 3, and a differential pressure acting force corresponding to the pressure difference between the fluid pressure in the common passage 94 and the fluid pressure in the reservoir 78 is the valve. This acts in the direction of separating the child 180 from the valve seat 182. The magnitude of the hydraulic pressure in the common passage 94 is controlled by continuous control of the current supplied to the solenoid 186. Note that the pressure-reducing linear control valve 316 is not indispensable, and the hydraulic pressure in the common passage 94 can be controlled to be reduced by using the pressure-reducing valve 156 when the holding valve 153 is open as in the first embodiment.

  Further, a separation valve 320 is provided between the common passage 94 and the connection portion of the servo pressure passage 190 and the connection portion of the individual passage 150RR. The separation valve 320 is a normally closed electromagnetic on-off valve. In other words, the mechanical pressure booster 96 is connected to a portion of the common passage 94 on the side where the brake cylinders 42FL and FR of the front wheels 2 and 4 are connected to a portion where the separation valve 320 is provided. The holding valves 153RLa and RRa provided corresponding to the brake cylinders 52RL and RR of the left and right rear wheels 46 and 48 are normally opened.

  Note that the separation valve 320 is not essential. Further, the holding valves 153RLa and RRa can be normally closed valves.

  On the other hand, in this embodiment, the output side shut-off valve 192 is not provided. When the high-pressure shut-off valve 312 is in the closed state, the mechanical movable portion 98 is hardly operated. Further, the hydraulic pressure of the master cylinder 62 is not supplied to the large-diameter side chamber 110 when the input-side shut-off valve 148 is closed, and the stepped piston 104 is not moved forward by the hydraulic pressure of the master cylinder 62. . Therefore, when the high-pressure shut-off valve 312 is closed and the input-side shut-off valve 148 is closed, substantially the same effect as when the output-side shut-off valve is closed is obtained. Therefore, it is not necessary to provide the output side shut-off valve on the output side of the mechanical pressure booster 96. Further, the master passage 74 (directly connected master passage) is not connected to the pressurizing chamber 72. Since the master passage 311 (non-directly connected master passage) is provided, the necessity of providing the master passage 74 in parallel is low. Further, a master cylinder pressure sensor 222FR is provided in the master passage 76. By providing two master cylinder pressure sensors, the master cylinder pressure can be detected by the other even if one becomes abnormal.

<Operation in hydraulic brake device>
1) When the system is normal As shown in FIG. 17, the input side shutoff valve 148 is closed, the simulator control valve 202 is opened, and the high pressure shutoff valve 312 is closed. Further, the pressure reducing valves 156RL, RR of the left and right rear wheels 46, 48 are closed, and the separation valve 320 is opened. In the state where the brake cylinder 42FR is disconnected from the master cylinder 62 and the operation of the mechanical pressure increasing device 96 is prohibited, the hydraulic pressure in the common passage 94 is increased by using the output hydraulic pressure of the power hydraulic pressure source 64. It is controlled by the pressure linear control valve 172 and the pressure reduction linear control valve 316 and supplied to the brake cylinders 42 and 52. Although the common passage 94 and the small-diameter side chamber 112 of the mechanical pressure increasing device 96 are in communication with each other, the hydraulic pressure in the small-diameter side chamber 112 is returned to the master input passage 310 because the input-side shut-off valve 148 is closed. Absent. Further, since the high pressure shut-off valve 312 is in the closed state, the hydraulic pressure of the accumulator 66 is not supplied to the high pressure chamber 114, and the hydraulic pressure of the small diameter side chamber 112 is maintained. As will be described later, when the hydraulic pressure in the small-diameter side chamber 112 is supplied to the large-diameter side chamber 110 via the in-piston check valve 130, the stepped piston 104 is advanced and comes into contact with the valve-opening member 125. The inner communication path 129 is blocked. Further, since the input side shut-off valve 148 is in the closed state, the stepped piston 104 is prevented from retreating in principle. For this reason, it is considered that this hardly affects the control of the hydraulic pressure in the common passage 94.
In the present embodiment, since the holding valves 153RLa and RRa are normally opened, it is not necessary to supply current to the solenoid during normal braking operation, and power consumption can be reduced accordingly.

2) When the control system is abnormal As shown in FIGS. 18 and 19, the current is not supplied to all the solenoids, so that the control system is returned to the original position.
2-1) When the hydraulic pressure in the large-diameter side chamber 110 is equal to or lower than the operation start pressure of the mechanical movable unit 98 As shown in FIG. In this case, the hydraulic pressure in the pressurizing chamber 72 is supplied to the common passage 94 through the mechanical valve input passage 310, the bypass passage 136, and the servo pressure passage 190, and is supplied to the brake cylinders 42 of the left and right front wheels 2 and 4. Since the valve opening pressure of the input-side check valve 99 is very small, it becomes possible to quickly supply the hydraulic fluid to the brake cylinder 42 in accordance with the operation of the brake pedal 60, and to reduce the delay in the effect of the hydraulic brake 40. be able to. As described above, when the control system is abnormal, the brake cylinders 42FL and FR of the left and right front wheels 2 and 4 are actuated, so that the yaw moment can be hardly generated when the center of gravity of the vehicle is substantially at the center in the left and right direction. .

2-2) When the hydraulic pressure in the pressurizing chamber 72 is higher than the operation start pressure of the mechanical movable unit 98 2-2-1) When the hydraulic pressure of the hydraulic fluid stored in the accumulator 66 is higher than the operation permission pressure Even if the operation of 65 is stopped, if the hydraulic pressure of the hydraulic fluid stored in the accumulator 66 is higher than the operation permission pressure, the operation of the mechanical movable unit 98 is permitted. As indicated by the solid line in FIG. 19, the stepped piston 104 is advanced by the hydraulic pressure in the large-diameter side chamber 110, contacts the valve opening member 125, and the high-pressure supply valve 116 is switched to the open state. The small-diameter side chamber 112 is shut off from the large-diameter side chamber 110, and high-pressure hydraulic fluid is supplied from the accumulator 66 through the high-pressure side check valve 100 to the high-pressure chamber 114. The hydraulic pressure (servo pressure) in the small-diameter side chamber 112 is made higher than the hydraulic pressure in the master cylinder 62, supplied to the common passage 94, and supplied to the brake cylinders 42 FL and 42 RR of the left and right front wheels 2 and 4. The hydraulic pressure in the small diameter side chamber 112 is determined by the hydraulic pressure in the large diameter side chamber 110 and the ratio of the pressure receiving area between the large diameter portion and the small diameter portion of the stepped piston 104.

2-2-2) When the hydraulic pressure of the hydraulic fluid stored in the accumulator 66 is equal to or lower than the operation permission pressure When the hydraulic pressure of the hydraulic fluid stored in the accumulator 66 is equal to or lower than the set pressure, it is shown in FIG. Similarly to the case, the hydraulic pressure in the pressurizing chamber 72 of the master cylinder 62 is supplied to the brake cylinders 42 of the left and right front wheels 2, 4 through the mechanical valve input passage 310, the bypass passage 136, the servo pressure passage 190, and the common passage 94. The On the other hand, at the beginning of the operation of the hydraulic brake 40, the hydraulic pressure of the hydraulic fluid stored in the accumulator 66 was higher than the operation permission pressure. However, the hydraulic fluid stored in the accumulator 66 by the operation of the mechanical movable unit 98. When the hydraulic pressure of the accumulator 66 decreases and becomes lower than the operation permission pressure, the hydraulic fluid is not supplied from the accumulator 66 to the high pressure chamber 114. Thereby, the operation of the mechanical movable unit 98 becomes impossible. For example, when a pumping brake operation is performed, the amount of hydraulic fluid consumed by the accumulator 66 increases and the accumulator pressure may decrease. The forward movement of the stepped piston 104 is prevented (it is considered to abut against the stopper), and the hydraulic pressure in the small-diameter side chamber 112 does not increase any more, and the mechanical movable unit 98 cannot exhibit the boosting function. The hydraulic pressure in the pressurizing chamber 72 is higher than the hydraulic pressure in the small-diameter side chamber 112, and as shown by the broken line in FIG. 19, the hydraulic pressure in the pressurizing chamber 72 of the master cylinder 62 is changed to the bypass passage 136 and the servo pressure passage 190. And supplied to the common passage 94. The hydraulic pressure in the pressurizing chamber 72 of the master cylinder 62 is supplied to the brake cylinders 42FL and 42FR of the left and right front wheels 2 and 4 without being boosted.

  Further, since the separation valve 320 is in the closed state, the hydraulic pressure of the mechanical movable portion 98 is prevented from being supplied to the brake cylinders 52RL and 52RR of the left and right rear wheels 46 and 48. As a result, liquid shortage is suppressed, and insufficient pressure increase of the brake cylinders 42FL and FR of the left and right front wheels 2 and 4 can be suppressed. Furthermore, the volume of the pressurizing chamber 72 in the master cylinder 62 can be increased. If the volume of the pressurizing chamber 72 is increased, it is possible to avoid a shortage of fluid even when hydraulic fluid is supplied to both the brake cylinders 42FL and FR of the left and right front wheels 2 and 4. In this case, the stroke of the driver's brake pedal 60 may be increased.

3) When there is a possibility of leakage As shown in FIG. 20, the input side shutoff valve 148 is opened, the high pressure shutoff valve 312 is closed, and the master shutoff valve 194FR is opened. Further, the pressure reducing valves 156RL, RR are closed for the left and right rear wheels 46, 48. Further, the separation valve 320 is closed, and the holding valve 153FR of the right front wheel 4 is closed.
(a) While the brake cylinders 52 of the left and right rear wheels 46 and 48 are disconnected from the brake cylinders 42 of the left and right front wheels 2 and 4, the hydraulic pressure of the power hydraulic pressure source 64 is increased by the linear pressure increasing control valve 172 Controlled by a control valve 316 and supplied.
(b) The hydraulic pressure in the pressurizing chamber 70 of the master cylinder 62 is supplied to the brake cylinder 42FR of the right front wheel 4 while being disconnected from the three brake cylinders 42FL, 52RL, RR.
(c) The hydraulic pressure in the pressurizing chamber 72 is mechanically applied to the brake cylinder 42FL of the left front wheel 2 while being disconnected from the brake cylinders 52RL and RR of the left and right rear wheels 46 and 48 and the brake cylinder 42FR of the right front wheel 4. Supplied through a pressure booster 96 (bypass passage 136).
In this case, since the high-pressure shut-off valve 312 is in the closed state, the operation of the mechanical movable unit 98 is prevented even when the input-side shut-off valve 148 is in the open state. Therefore, equal hydraulic pressure is supplied to the brake cylinders 42FL, FR of the left and right front wheels 2, 4.

  Further, by closing the high-pressure shut-off valve 312, the hydraulic pressure of the power hydraulic pressure source 64 is prevented from being supplied to the mechanical pressure booster 96, and the three brake systems 330 FL, FR, and R are connected. Can be independent of each other. If the high-pressure shut-off valve 312 is in an open state (when the high-pressure shut-off valve 312 is not provided), the hydraulic pressure of the power-type hydraulic pressure source 64 includes the brake cylinders 52 of the left and right rear wheels 46 and 48. The brake system 330R is also supplied to the brake system 330FL including the brake cylinder 42FL of the left front wheel 2, and the brake systems 330R and 330FL cannot be made independent. For this reason, if a fluid leak occurs in the brake system 330FL, the hydraulic pressure of the power hydraulic pressure source 64 is consumed in the brake system 330FL, which may affect the brake system 330R. On the other hand, if the high-pressure shut-off valve 312 is closed, even if a liquid leak occurs in the brake system 330FL, the high-pressure shut-off valve 312 is caused to flow out from the power hydraulic pressure source 64 via the mechanical pressure booster 96. Can be prevented.

  That is, when the high-pressure cutoff valve 312 is closed and the separation valve 320 is closed, the three brake systems 330FL, FR, and R can be made independent of each other. Therefore, even if liquid leakage occurs in one of these three brake systems, it is possible to prevent the influence from affecting other brake systems. The brake system 330FR includes a brake cylinder 42FR, a master passage 76, a pressurizing chamber 70, a storage chamber 80, and the like. The brake system 330FL includes a brake cylinder 42FL, an individual passage 150FL, a common passage 94, a servo pressure passage 190, A mechanical pressure intensifying device 96, a master input passage 310, a pressurizing chamber 72, a storage chamber 82, and the like are included. A brake system 330R includes brake cylinders 52RL and RR, individual passages 150RL and RR, and a power hydraulic pressure source 64. , Including the storage chamber 84 and the like. Therefore, the fact that the brake systems 330FR, FL, R are made independent from each other means that the storage chambers 80, 82, 84 of the master reservoir 78 are also made independent from each other.

  Further, when the control system is abnormal (for example, the pump device 65 cannot be operated but the electromagnetic on-off valve can be controlled) and the hydraulic pressure stored in the accumulator 66 is lower than the operation permission pressure. In some cases, switching to the state of FIG. 20 is more effective than switching to the state of FIG. In the state where the operation of the mechanical movable portion 98 is prohibited, in the state of FIG. 18, the hydraulic pressure in the pressurizing chamber 72 is supplied to the brake cylinders 42FL and FR of the left and right front wheels, whereas in FIG. In the state, the pressurizing chambers 72 and 70 are communicated with the brake cylinders 42FL and FR of the left and right front wheels 2 and 4, respectively. As a result, the hydraulic fluid shortage in each of the brake cylinders 42FL and FR can be made difficult to occur.

4) When the hydraulic brake is released When the brake operation is released, the current is not supplied to the solenoids of all the valves, thereby returning the original position of FIG. Further, in the mechanical pressure increasing device 96, the stepped piston 104 is separated from the valve opening member 125. The hydraulic pressures in the brake cylinders 42FL and FR of the left and right front wheels 2 and 4 are returned to the master cylinder 62 (master reservoir 78) through the in-piston communication passage 129 and the in-piston check valve 130. The hydraulic pressures in the brake cylinders 52RL and RR of the left and right rear wheels 46 and 48 are returned to the reservoir 78 via the pressure reducing valve 156.

5) Ignition switch 234 OFF state When no current is supplied to the solenoids of all the solenoid on / off valves, the ignition switch 234 is returned to the original position shown in FIG. As in the case of the first embodiment, since the three brake systems 330FR, FL, and R are made independent, even if liquid leakage occurs in one system, it is well avoided that the influence is exerted on other systems. Is done. Further, since the mechanical pressure booster 96 is provided with an outflow prevention device, it is possible to prevent the hydraulic fluid from flowing out of the master reservoir 78 that passes through the mechanical pressure booster 96.

6) Check of mechanical pressure booster 96 In this embodiment, when a predetermined check condition is satisfied, it is checked whether or not the operation of the mechanical pressure booster 96 is normal.
The check program represented by the flowchart of FIG. 21 is executed at predetermined time intervals. In S11, it is determined whether or not a check condition is satisfied. If the check condition is not satisfied, no check is performed, but if the check condition is satisfied, an operation check of the mechanical pressure booster 96 is performed in S12. In this embodiment, (i) when the brake pedal 60 is operated for the first time after the ignition switch 234 is switched from OFF to ON, (ii) when the vehicle is stopped. . It can be considered that the vehicle is in a stopped state when the traveling speed of the vehicle acquired based on the detection value of the wheel speed sensor 230 is equal to or lower than a set speed that can be considered to be in the stopped state.

  As described above, the check is performed in the operation operation state of the brake pedal 60. Further, it is desirable that the check be performed while the vehicle is stopped, but it is not essential to perform the check while the vehicle is stopped. Furthermore, there are two methods of check, check 1 and check 2. Checks 1 and 2 may be performed selectively as appropriate, or when the check condition is satisfied, both checks 1 and 2 may be performed, or the master cylinder hydraulic pressure is greater than or equal to the set pressure Check 1 can be performed, and when the pressure is lower than the set pressure, Check 2 can be performed. As will be described later, the set pressure of the master cylinder hydraulic pressure can be set to such a level that the check 1 can accurately determine whether or not the operation of the mechanical pressure booster 96 is normal. The set pressure can be referred to as a checkable pressure.

6-1) Check 1
In Check 1, the operation of the mechanical pressure intensifier 96 is normal by comparing the input hydraulic pressure Pin (Pm) of the mechanical valve movable portion 98 with the output hydraulic pressure Pout (Pwc) of the mechanical valve movable portion 98. Is detected. As shown in FIG. 22 (a), the pressure-increasing linear control valve 172 and the pressure-decreasing linear control valve 316 are closed, the input side shut-off valve 148 is opened, and the high-pressure shut-off valve 314 is opened. 96 operations are allowed. Then, the detection value Pm of the master cylinder pressure sensor 222FL (the input hydraulic pressure Pin of the mechanical valve movable unit 98) and the detection value Pw of the brake cylinder pressure sensor 226 (the output hydraulic pressure Pout of the mechanical valve movable unit 98) are compared. . When these belong to the normal region R shown in FIG. 22B, it can be determined that the operation of the mechanical pressure intensifying device 96 is normal. On the other hand, when not in the normal region R, it is determined that the operation of the mechanical pressure booster 96 is abnormal. The solid line in FIG. 22 (b) shows the relationship between Pin and Pout when the mechanical pressure booster 96 is operating normally.

  The operation of the mechanical pressure increasing device 96 is abnormal because (a) the power hydraulic pressure source 64 is abnormal (if the output hydraulic pressure of the power hydraulic pressure source 64 is low, the power hydraulic pressure source 64 This is a case where the hydraulic pressure is not supplied. For example, there may be causes such as liquid leakage of the accumulator 66, failure of the pump motor 92, liquid leakage of the high-pressure passage 132, etc.), (b) abnormal closure of the high-pressure cutoff valve 312; c) Abnormality of the mechanical pressure booster 96 (this is a case where the mechanical movable part 98 does not operate. For example, there are causes such as an inoperable abnormality such as a biting of the stepped piston 104, an abnormal close fixation of the high pressure supply valve 116, etc. (D) It is considered that this is caused by at least one of (d) an abnormally open sticking abnormality of the input side shut-off valve 148 and the like. Also, abnormalities in the master cylinder pressure sensor 222FL and the brake cylinder pressure sensor 226, abnormal closure of the separation valve 320, liquid leakage, etc. can be considered. On the other hand, when the operation of the mechanical pressure intensifying device 96 is normal, the operation of the mechanical movable unit 98 is normal, and the high-pressure hydraulic fluid is supplied from the power hydraulic pressure source 64, and the high pressure It is considered that the shut-off valve 312 and the input-side shut-off valve 148 are switched to the open state as instructed. In other words, when the operation of the mechanical pressure increase device 96 is normal, not only when the mechanical pressure increase device 96 is normal, but also members, devices, etc. related to the operation of the mechanical pressure increase device 96 Can also be determined to be normal.

Although the detection value of the master cylinder pressure sensor 222FL is used as the input hydraulic pressure Pin, the detection value of the master cylinder pressure sensor 222FR is used, or the value estimated based on the detection value of the stroke sensor 218 is used. You can also do it.
In addition, at least one of the above-described (a) power hydraulic pressure source 64, (b) high pressure cutoff valve 312, (c) mechanical pressure booster 96, and (d) input side cutoff valve 148 is normal. Is known in advance, or more specifically, when these components are known to be normal, if it is determined that the operation of the mechanical pressure booster 96 is abnormal, In some cases, the cause of the abnormality can be acquired.

6-2) Check 2
In Check 2, in the closed state of the mechanical input side shut-off valve 148 and the closed state of the high-pressure shut-off valve 312, the stepped piston 104 moves forward and the high-pressure supply valve 114 is switched to the open state. Increase fluid pressure. Thereafter, based on the change in the hydraulic pressure in the small-diameter side chamber 112 after controlling the high-pressure shut-off valve 312 to be switched to the open state, it is determined whether the operation of the mechanical pressure booster 96 is normal. .
6-2-1) Pre-check control As shown in FIG. 23, when the mechanical input side shut-off valve 148 and the high-pressure shut-off valve 312 are closed, the pressure-increasing linear control valve 172 and the pressure-decreasing linear control valve 316 are commonly controlled. The fluid pressure in the passage 94 is set to the target fluid pressure Pref1. The target hydraulic pressure Pref1 is a value larger than the operation start pressure of the stepped piston 104, and is a value that the high pressure supply valve 116 should have been switched to the open state. When the stepped piston 104 is in the retracted end position, the small-diameter side chamber 112 and the large-diameter side chamber 110 are in communication with each other through the in-piston communication passage 129. By supplying the hydraulic pressure to the small-diameter side chamber 112, the hydraulic pressure is supplied to the large-diameter side chamber 110 through the in-piston communication path 129 and the in-piston check valve 130. When the hydraulic pressure in the large-diameter side chamber 110 is smaller than the operation start pressure, the in-piston communication path 129 is kept open, and along with the increase in the hydraulic pressure in the small-diameter side chamber 112 along the solid line in FIG. Thus, the hydraulic pressure in the large-diameter side chamber 110 is increased. These hydraulic pressures have the same magnitude (Pin = Pout).

  Thereafter, when the hydraulic pressure in the large-diameter side chamber 110 reaches the operation start pressure, the stepped piston 104 is advanced. When the stepped piston 104 comes into contact with the valve opening member 125, the intra-piston communication passage 129 is blocked, the valve opening member 125 is advanced, and the high pressure supply valve 116 should be switched to the open state. The hydraulic pressure in the small-diameter side chamber 112 is larger than the hydraulic pressure in the large-diameter side chamber 110, and becomes a servo pressure. As indicated by the alternate long and short dash line in FIG. 25A, the hydraulic pressure in the large-diameter side chamber 110 increases as the hydraulic pressure in the small-diameter side chamber 112 increases. Then, the hydraulic pressure in the small-diameter side chamber 112 (detected value of the brake cylinder pressure sensor 226) is brought close to the target hydraulic pressure Pref1 by the control of the pressure-increasing linear control valve 172. After reaching the target hydraulic pressure Pref1, the hydraulic pressure in the small-diameter side chamber 112 is reduced mainly by the control of the pressure-reducing linear control valve 316, and is brought close to the target hydraulic pressure Pref2. As shown in FIG. 25A, the hydraulic pressure in the small-diameter side chamber 112 and the hydraulic pressure in the large-diameter side chamber 110 are substantially equal due to the hysteresis of the mechanical movable portion 98. In this embodiment, the hydraulic pressure in the small-diameter side chamber 112 is decreased after the stepped piston 104 is moved forward due to the increase in the hydraulic pressure in the small-diameter side chamber 112. The direction is reversed (the hysteresis is reversed).

  Since the check is performed in a state in which the brake pedal 60 is operated, the holding valve 153 is in the open state and the pressure reducing valve 156 is in the closed state. The hydraulic pressures of all the brake cylinders 42 and 52 are the target hydraulic pressures. Pref1. In this sense, the target hydraulic pressure Pref1 can be set to a magnitude determined by the driver's required braking force. In most cases, the requirement of greater than the starting pressure is met.

6-2-2) Switching of the high-pressure shut-off valve 312 Next, as shown in FIG. 24, the pressure-increasing linear control valve 172 and the pressure-decreasing linear control valve 316 are closed to form a closed space around the small-diameter side chamber 112. . The space including the small-diameter side chamber 112 and the brake cylinder hydraulic pressure sensor 226 is blocked from the reservoir 78 and the power hydraulic pressure source 64 and also from the master cylinder 62 (the master cutoff valve 194FR is closed). In this state, the supply current to the solenoid is controlled so that the high-pressure shut-off valve 312 switches from the closed state to the open state (the supply current is set to 0). If high-pressure hydraulic fluid is supplied from the power hydraulic pressure source 64 to the small-diameter side chamber 112, the hydraulic pressure in the small-diameter side chamber 112 is immediately increased. In this embodiment, as shown in FIG. 25 (b), the detection value Pwc of the brake cylinder pressure sensor 226 should be increased to Pref1, and then increased along the alternate long and short dash line. Therefore, if the detected value of the brake cylinder pressure sensor 226 is lower than the hydraulic pressure Pref1 after controlling the current supplied to the solenoid so that the high-pressure shut-off valve 312 switches from the closed state to the open state, in other words, the detected value When the increase amount ΔPwc of Pwc is smaller than the determination threshold value ΔPth (= Pref1−Pref2), it is determined that the operation of the mechanical pressure booster 96 is not normal.

FIG. 26 shows a routine when the check 2 is performed in S12.
In S21, the input side shut-off valve 148 is controlled to be closed, and the high-pressure shut-off valve 312 is controlled to be closed. In S22, the hydraulic pressure in the small-diameter side chamber 112 (common passage 94, brake cylinders 42, 52) is controlled to be increased by controlling the current supplied to the pressure-increasing linear control valve 172. In S23, it is determined whether or not the detection value Pwc of the brake cylinder hydraulic pressure sensor 226 has approached the target hydraulic pressure Pref1. S22 and S23 are repeatedly executed until the target hydraulic pressure Pref1 is approached. When the target hydraulic pressure Pref1 is approached, the hydraulic pressure in the small-diameter side chamber 112 is controlled to be reduced mainly by the control of the pressure-reducing linear control valve 316 in S24. In S25, it is determined whether or not the hydraulic pressure in the small-diameter side chamber 112 has approached the target hydraulic pressure Pref2. Control of the pressure-reducing linear control valve 316 is continued until it approaches the target hydraulic pressure Pref2. Thereafter, in S26, the pressure-increasing linear control valve 172 and the pressure-decreasing linear control valve 312 are closed, and the high-pressure cutoff valve 312 is opened, so that a closed space is formed. In S27, it is determined whether or not the detection value Pwc of the brake cylinder hydraulic pressure sensor 226 is equal to or higher than Pref1. If the brake cylinder hydraulic pressure has increased, it is determined in S28 that the operation of the mechanical pressure booster 96 is normal. If not, the operation of the mechanical pressure booster 96 is not normal in S29. It is determined.

Thus, in this embodiment, the check can be performed in a state where the brake pedal 60 is operated, that is, during normal braking. Therefore, the chances of checking can be increased, and the reliability of the hydraulic brake system can be improved.
Further, since the input side shut-off valve 148 is in the closed state, the reaction force applied to the brake pedal 60 does not change due to the check, and the driver's operation feeling can be prevented from being lowered.
Furthermore, since the input side shut-off valve 148 is in the closed state, the target hydraulic pressure Pref can be set to a magnitude that is not related to the driver's brake operation state. In Check 1, when the input hydraulic pressure Pm is lower than the checkable pressure, it is not possible to accurately determine whether or not the operation of the mechanical pressure booster 96 is normal. On the other hand, in the check 2, since the target hydraulic pressures Pref1, 2 can be set to an arbitrary magnitude (in a range larger than the operation start pressure), is the operation of the mechanical pressure booster 96 normal? It is possible to accurately determine whether or not, and it is possible to improve the reliability of the hydraulic brake system.

Note that it is possible to wait until a predetermined set time elapses before S27 is executed. In this embodiment, it is possible to accurately detect the presence or absence of a change in hydraulic pressure on the small-diameter chamber side 112.
In addition, it is not indispensable that the target hydraulic pressure Pref1 has a magnitude corresponding to the driver's required braking torque. There is no limitation on the target hydraulic pressure as long as the high pressure supply valve 116 can be switched to an open state.
Furthermore, the check 2 can be executed when the brake pedal 60 is not operated, in other words, when a parking brake (not shown) is in an operating state (the shift position may be in the parking position). In this case, all the holding valves 153 can be closed, or the holding valves 153RL and RR corresponding to the left and right rear wheel brake cylinders 52 can be closed. In the present embodiment, the closed space including the small-diameter side chamber 112 and the brake cylinder pressure sensor 226 can be narrowed, and a change in hydraulic pressure in the small-diameter side chamber 112 can be accurately detected. Further, it is less necessary to set the target hydraulic pressure Pref1 to a magnitude according to the driver's required braking torque.

  In the check 2, the steps S24 and S25 are not indispensable. After the hydraulic pressure in the small-diameter side chamber 112 reaches the target hydraulic pressure Pref1 (when the determination in S23 is YES), it is possible to perform control to switch the high-pressure side shut-off valve 312 from the closed state to the open state. In that case, the hydraulic pressure in the small-diameter side chamber 112, that is, the brake cylinder hydraulic pressure should increase along the alternate long and short dash line, as shown in FIG. Therefore, the brake cylinder hydraulic pressure after the elapse of a predetermined set time after the control for switching the high-pressure side shut-off valve 312 from the closed state to the open state is performed is higher than the hydraulic pressure Pref1 by the abnormality determination threshold value ΔPth. When it increases above, it is considered that the operation of the mechanical movable part 98 is normal.

Further, when the target hydraulic pressure Pref1 does not reach the set time in S23, or when the target hydraulic pressure Pref2 does not reach the set time in S25, the mechanical pressure increasing device 96 is not operated normally. Can be determined.
Further, if the brake cylinder hydraulic pressure Pwc increases transiently after controlling the high pressure shut-off valve 312 to switch from the closed state to the open state, it is determined that the operation of the mechanical pressure booster is normal. It is also possible.
Further, the check can be executed after the ignition switch 234 is switched from ON to OFF. In this case, the target hydraulic pressure in the small-diameter side chamber 112 can be set to an arbitrary size.
In addition, even when the check is performed by the first check unit, the hydraulic pressure in the small-diameter side chamber 112 can be controlled.
Further, the present embodiment is not limited to the hydraulic brake system and can be widely applied to a hydraulic operation system.

  In the present embodiment, a pressure booster check device is configured by a portion that stores a check program of the brake ECU 56 and a portion that executes the check program. Of these, the first check unit and the second check unit are configured by the part that stores S12 and the part that executes S12. The first check unit and the second check unit are also an input blocking state check execution unit and an in-operation check unit. In the first check unit, the first normality determination unit is configured by a portion that determines that the operation of the mechanical pressure intensifier 96 is normal by executing the first check, and in the second check unit, S27 and 28 are performed. The second normality determination unit and the servo state transition normality determination unit (the servo state pressure increase normality determination unit when S24 and 25 are not executed) are configured by the storage part, the execution part, etc. The high pressure shut-off valve control unit is configured by the storing part, the executing part, etc., and the pre-checking output side hydraulic pressure control unit is configured by the storing part, the executing part, etc., of which S22, S23 The pressure increase control unit is configured by the part that stores the data, the part that executes the process, and the like, and the part that stores S24 and 25, the part that executes the process, and the like. In addition, the closed space forming unit is configured by a part that stores S26, a part that executes S26, and the like.

Although a plurality of embodiments have been described above, two or more of the plurality of embodiments may be combined with each other.
In addition, the present invention can be implemented in a mode in which a plurality of examples are combined, and in addition to the mode described above, the present invention is implemented in a mode in which various modifications and improvements are made based on the knowledge of those skilled in the art. Can do.

  40, 50: Hydraulic brake 42, 52: Brake cylinder 54: Hydraulic pressure control unit 56: Brake ECU 60: Brake pedal 62: Master cylinder 64: Powered hydraulic pressure source 66: Accumulator 70, 72: Pressurizing chamber 74, 76: Master passage 94: Common passage 96: Mechanical pressure booster 98: Mechanical movable portion 99: Input side check valve 100: High pressure side check valve 104: Stepped piston 110: Large diameter side chamber 112: Small diameter side chamber 116 : High pressure supply valve 132: High pressure side check valve 136: Bypass passage 148: Input side shutoff valve 150: Individual passage 153: Holding valve 156; Pressure reducing valve 170: Power hydraulic pressure passage 172: Boosting linear control valve 190: Servo pressure Passage 192: Output side shut-off valve 218: Brake switch 220: Stroke sensor 222: Master cylinder Pressure sensor 226: Brake cylinder pressure sensor 228: Level warning 250FL, FR, R: Brake hydraulic system 260, 270, 280: Flow control device 272, 282: First check valve 274.284: Second check valve 300 , 302: Steering wheel 330FL, FR, R: Brake hydraulic system

Claims (5)

A hydraulic brake that is provided corresponding to each of a plurality of wheels provided in the vehicle, is operated by a hydraulic pressure of a brake cylinder, and suppresses rotation of the wheel;
A brake operating member provided in the vehicle and operable by a driver;
At least one manual hydraulic pressure source that generates hydraulic pressure by operating the brake operating member;
At least one of the plurality of brake cylinders is operated by at least one hydraulic pressure of the at least one manual hydraulic pressure source and has a hydraulic pressure higher than the hydraulic pressure of the one manual hydraulic pressure source. and a pressure booster that can be output to,
A stroke simulator connected to the one manual hydraulic pressure source;
A hydraulic brake system comprising: an input side shut-off valve that is a normally open electromagnetic on-off valve provided between the pressure booster and the one manual hydraulic pressure source. 2. The hydraulic brake system according to claim 1, wherein the pressure increasing device includes a stepped piston, the one manual hydraulic pressure source is connected to a large-diameter side chamber, and the at least one brake cylinder is connected to a small-diameter side chamber. . A manual hydraulic pressure source is connected to at least one of the at least one brake cylinder by a manual passage, bypassing the pressure increasing device, and is a normally closed electromagnetic on-off valve in the manual passage. The hydraulic brake system according to claim 1 or 2, wherein a shut-off valve is provided. The hydraulic brake system closes the input-side shut-off valve when the operation of the stroke simulator is permitted, and opens the input-side shut-off valve when the operation of the stroke simulator is blocked. The hydraulic brake system according to any one of claims 1 to 3 , comprising a one-input-side shut-off valve control device. The hydraulic brake system
A powered hydraulic pressure source that generates hydraulic pressure by supplying electrical energy;
A power hydraulic pressure control device capable of electrically controlling the hydraulic pressures of the plurality of brake cylinders using the hydraulic pressure of the power type hydraulic pressure source;
If the power hydraulic pressure control device is hydraulically controllable to a state of said plurality of brake cylinders, the input-side shutoff valve claims 1 and a second input-side shutoff valve control device for the closed state 5. The hydraulic brake system according to any one of 4 .

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