JP2005199748A - Hydraulic brake system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate disadvantages in a hydraulic brake system including a master cylinder and a power hydraulic pressure source.
A pressurizing chamber (34, 36) of a master cylinder (30) is connected to the left front and right front brake cylinders (20, 22), and communicated and shut off by first and second master cut valves (50, 52). The left front, right front, left rear, and right rear brake cylinders 20 to 26 are connected, and the brake cylinder pressure is controlled by the left front, right front, left rear, and right rear valve devices 100 to 106. The first valve control unit 142 controls the first and second master cut valves 50 and 52, the left front and right front valve devices 100 and 102, and the second valve control unit 144 controls the left rear and right rear valve devices 104 and 106. To do. After the ignition switch is turned off, the second relay 166 is turned off, while the first relay 164 is kept on for the set time, the first and second master cuts 50 and 52 are kept closed, and the supply current is reduced. Prevent kickback while saving.
[Selection] Figure 1

Description

  The present invention relates to a hydraulic brake system, and in particular, includes a master cylinder and a power hydraulic pressure source, and the hydraulic pressure of the brake cylinder is directly controlled by the operation of the brake operating member by the driver, or the brake operating member The present invention relates to an improvement of a hydraulic brake system that is electrically controlled based on operation.

This type of hydraulic brake system includes, for example, a master cylinder, a power hydraulic pressure source, a brake cylinder provided on each of the front, rear, left and right wheels, a master cut valve, and four brake cylinders as described in Patent Document 1 Each of which includes a valve device and a valve control device. The master cut valve has a liquid passage that connects one of the two pressurization chambers of the master cylinder to the left front and right front brake cylinders, and a liquid passage that connects the other pressurization chamber to the left rear and right rear brake cylinders. And provided respectively. During normal braking, the two master cut valves are closed, the hydraulic pressure generated in the power hydraulic pressure source is supplied to the four brake cylinders, and the brake cylinder pressures, which are the respective hydraulic pressures, are controlled by the valve device. The
JP 2001-328518 A Japanese Patent Laid-Open No. 11-48945 JP 2003-205838 A JP 2002-212386 A

However, this type of hydraulic brake system has various disadvantages.
For example, in the hydraulic brake system described in Patent Document 1, the valve control device includes two computers, one of which controls one of the left front valve device, the right rear valve device, and the master cut valve, and the other is the right front valve device. The other of the left rear valve device and the master cut valve is controlled, and a current is supplied to each of these two electric braking control systems from a power source through different current supply lines. In this hydraulic brake system, the current is supplied to the components of the electric brake control system as long as the brake pedal is depressed even after the ignition switch is switched from the ON state to the OFF state. Yes. Therefore, for example, as long as the brake pedal is depressed, the two master cut valves are also kept closed, and the occurrence of kickback is avoided. The brake cylinder pressure, which is electrically controlled by the valve device, is often higher than the hydraulic pressure generated in the pressurizing chamber of the master cylinder, and the master is in a state where the brake pedal is depressed and the brake cylinder pressure is generated. If the cut valve is opened, high brake cylinder pressure will act on the pressurizing piston of the master cylinder and the brake pedal will be pushed back to cause kickback. If the valve is opened, it is avoided that the driver feels uncomfortable even when the brake pedal is pushed back. However, in order to keep the two master cut valves closed after the ignition switch is turned off, it is necessary to continue to supply current to both of the two electric braking control systems, and current consumption increases.
In Patent Document 2, one of the two pressure chambers of the master cylinder is connected to the left front and right rear brake cylinders, and the other is connected to the right front and left rear brake cylinders. Two hydraulic pressure control devices that are provided for each and control the brake cylinder pressure, and two hydraulic pressure control devices that are provided for each of the right front and left rear brake cylinders and control the brake cylinder pressure are respectively separate from each other. A hydraulic brake system controlled by a computer is described. In this hydraulic brake system, when one electric braking control system fails and only the other is operated, only the hydraulic pressures of two brake cylinders located on the diagonal of the vehicle are electrically controlled, Since the hydraulic pressures of the two brake cylinders are not electrically controlled, a difference occurs in the braking force between the two systems, a yaw moment is generated in the vehicle, and traveling stability is reduced.
The present invention has been made in view of the above circumstances, and has been made to solve various problems in a hydraulic brake system including a master cylinder and a power hydraulic pressure source.

  In order to solve the above problems, a hydraulic brake system according to the present invention includes: (a) a master that generates the same hydraulic pressure in the first pressurization chamber and the second pressurization chamber that are independent according to the operation of the brake operation member; A cylinder, (b) a power hydraulic pressure source that generates hydraulic pressure by power, (c) a left front brake cylinder, a right front brake cylinder, a left rear brake cylinder, and a right rear brake cylinder provided on each of the front, rear, left and right wheels, (D) provided in a first master cylinder passage and a second master cylinder passage that connect each of at least one of the four brake cylinders and each of the first and second pressure chambers independently of each other. A first master cut valve and a second master cut valve; (e) a power pressure passage connecting the power hydraulic pressure source and each of the four brake cylinders, and provided in them A left front valve device, a right front valve device, a left rear valve device, and a right rear valve device that control the hydraulic pressure of each brake cylinder independently of each other; (f) the left front and right front valve devices and the left rear and right rear valve devices; A first valve control unit that controls the first and second master cut valves, and a second valve that controls the other of the left front and right front valve devices and the left rear and right rear valve devices. And a valve control device including a control unit.

In the present hydraulic brake system, the configuration of piping connecting the first and second pressurizing chambers of the master cylinder and the brake cylinder includes the following. A mode in which the first and second pressure chambers are connected only to the left front brake cylinder and only the right front brake cylinder (referred to as front / front piping), and the first and second pressure chambers are respectively left rear brake cylinders. Only the right rear brake cylinder is connected to the right rear brake cylinder (referred to as rear / rear piping), and the left rear brake cylinder is connected to the right rear brake cylinder, and the right front brake cylinder is connected to the left rear brake cylinder. (Referred to as cross piping), one of the first and second pressure chambers is connected to the left front brake cylinder and the right front brake cylinder, and the other is connected to the left rear brake cylinder and the right rear brake cylinder (front and rear (Referred to as piping).
Examples of the brake operation member include a brake pedal and a brake lever. The brake pedal is usually operated by foot, and the brake lever is usually operated by hand.
The valve device may include, for example, a pressure increasing electromagnetic valve and a pressure reducing electromagnetic valve constituted by a linear solenoid valve, as described in the section of the embodiment, or may include two electromagnetic opening / closing valves. Alternatively, it may be constituted by one electromagnetic direction switching valve. Linear solenoid valves are already known, for example, from Japanese Patent Application Laid-Open No. 2003-205838.
In the control of the valve device performed by each of the first and second valve control units, the four valve devices are divided into two front and rear, and in terms of electric braking control, the front wheel electric braking control system and the rear wheel electric braking control are performed. Two systems before and after the system are controlled. The first and second master cut valves are controlled by one of the first and second valve control units, and are controlled with the left front and right front valve devices, or with the left rear and right rear valve devices.
According to the hydraulic brake system of the present invention, various inconveniences can be avoided as described in the [Aspect of the Invention] section. For example, since two master cut valves are controlled by one valve control unit, for example, when an ignition switch is switched from an ON state to an OFF state as described later, kickback occurs while suppressing current consumption. Can be avoided.
In addition, since the electric braking control is performed in two front and rear systems, even if one of the control systems breaks down and only the other is operated, the brake cylinder pressure is not electrically cross-controlled. It is avoided that the yaw moment is generated and the running stability is lowered.

Aspects of the 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. As with the claims, each aspect is divided into sections, each section is numbered, and is described in a form that cites the numbers of other sections as necessary. This is for the purpose of facilitating the understanding of the claimable invention, and is not intended to limit the combinations of the constituent elements constituting the claimable invention to those described in the following sections. In other words, the claimable invention should be construed in consideration of the description accompanying each section, the description of the embodiments, etc., and as long as the interpretation is followed, another aspect is added to the form of each section. In addition, an aspect in which constituent elements are deleted from the aspect of each item can be an aspect of the claimable invention.

  In each of the following paragraphs, (1) corresponds to claim 1, (2) corresponds to claim 2, and (3) and (7) combine to claim 3. To do.

(1) a master cylinder that generates the same hydraulic pressure in the first pressurization chamber and the second pressurization chamber independent according to the operation of the brake operation member;
A power hydraulic pressure source that generates hydraulic pressure by power,
A left front brake cylinder, a right front brake cylinder, a left rear brake cylinder and a right rear brake cylinder provided on each of the front, rear, left and right wheels;
A first master provided in each of a first master cylinder passage and a second master cylinder passage that connect each of at least one of the four brake cylinders and each of the first and second pressure chambers independently of each other. A cut valve and a second master cut valve;
A power pressure passage connecting the power hydraulic pressure source and each of the four brake cylinders, and a left front valve device, a right front valve device, and a left rear valve device provided in them for independently controlling the hydraulic pressure of each brake cylinder And a right rear valve device,
A first valve control unit that controls one of the left front and right front valve devices, the left rear and right rear valve devices, the first and second master cut valves, the left front and right front valve devices, and the A hydraulic brake system including a valve control device including a second valve control unit that controls the other of the left rear and right rear valve devices.
(2) The first master cylinder passage and the second master cylinder passage are connected to the left front and right front brake cylinders and the first and second pressure chambers independently of each other. Two front passages, the first valve control unit controls the left front and right front valve devices and the first and second master cut valves, and a second valve control unit controls the left rear and right rear valve devices. The hydraulic brake system according to item (1), wherein the hydraulic brake system is controlled.
In the present hydraulic brake system, the front / front piping and the cross piping are included as the configuration of the piping connecting the two pressurizing chambers of the master cylinder and the brake cylinder. Both of the two pressurizing chambers are connected to the front brake cylinder, and the first and second master cut valves are controlled by the first valve control unit together with the left front and right front valve devices constituting the front wheel electric braking control system.
(3) The hydraulic brake system according to (1) or (2), including a power supply device that supplies current to the valve control device.
The power supply device includes at least one power supply, and includes, for example, a main power supply and a sub power supply as in the hydraulic brake system described in the section (4).
(4) The main power source that supplies current to the first and second valve control units, and the first valve control unit and the second valve control unit when the main power source cannot supply current or is inappropriate. And a sub power source for supplying current to at least one of the hydraulic brake system according to (3).
Inability to supply current means that, for example, even if the main power supply fails and is charged, the voltage once lowered does not rise, and the current necessary for control cannot be supplied. For example, it is not a failure and the voltage is low, but it can be increased by charging and returned to the state where the current necessary for control is supplied, but at present, the amount of charge is insufficient for control. is there.
By providing the sub power supply, when either one of the first and second valve control units is operated, current is supplied to the valve control unit, and when both are operated, current is supplied to both valve control units. Supplied. If only one of the first and second valve control units is activated when current is supplied by the sub power supply, current consumption can be saved. In any case, even if the main power source cannot supply current or is in an inappropriate state for some reason, the valve control unit, the valve device and the like are not disabled, and the brake cylinder pressure is electrically controlled.
(5) A state in which current is supplied from the sub power source to the first valve control unit or the second valve control unit when the main power source cannot supply current or is inappropriate for the valve control device. In the left valve device and the right valve device controlled by the one valve control unit, the one valve control unit is compared with a state in which current is supplied from the main power source to the first and second valve control units. A control changing unit is provided for controlling the left valve device and the right valve device so as to increase the hydraulic pressure of the left and right brake cylinders, each of which is controlled by the hydraulic pressure according to (4). Pressure brake system.
In a state where the first valve control unit controls the left front and right front valve devices and current is supplied to the first valve control unit, each hydraulic pressure of the left front and right front brake cylinders is electrically controlled, and each brake of the left and right front wheels is controlled. Is activated. When braking, the load on the front of the vehicle is greater than that on the rear due to load movement, so if current is supplied to the first valve control unit and the hydraulic pressure of the left front and right front brake cylinders is electrically controlled, The vehicle can be braked effectively.
The second valve control unit controls the left rear and right rear valve devices and supplies current to the second valve control unit so that each hydraulic pressure of the left rear and right rear brake cylinders is electrically controlled. May be effective. For example, in a vehicle in which an electric motor for driving is provided on the left and right front wheels, and regenerative braking is performed, the hydraulic pressure of the left rear and right rear brake cylinders is electrically controlled to improve the braking effect as a whole vehicle. Can be obtained. The same applies to the case where the first valve control unit controls the left rear and right rear valve devices and current is supplied to the first valve control unit.
In a state in which a current is supplied to one of the first and second valve control units and the hydraulic pressures of two of the four brake cylinders are electrically controlled, the hydraulic pressure is increased so that the sub power supply Insufficient braking current is suppressed while suppressing current consumption of the vehicle. For example, when the hydraulic pressure is not supplied from the pressurizing chamber of the master cylinder to two brake cylinders whose hydraulic pressure is controlled by the valve control unit to which no current is supplied among the first and second valve control units, Although the hydraulic pressure is supplied from the pressurizing chamber, the shortage of the braking force is suppressed when the hydraulic pressure is lower than when the brake cylinder pressure is electrically controlled.
(6) In a state where the operation amount of the brake operation member is equal to or less than a set value, one of the first valve control unit and the second valve control unit operates, but the other does not operate (1) to The hydraulic brake system according to any one of (5).
In the state where the operation amount of the brake operation member is below the set value, the braking force required by the driver is the size of the area normally used, not so large, and the hydraulic pressures of the two brake cylinders are electrically It is often sufficient to control automatically, and current consumption can be saved.
Of the first and second valve control units, the valve control unit that controls the hydraulic pressure of the left front and right front brake cylinders may be operated, and the valve control unit that controls the hydraulic pressure of the left rear and right rear brake cylinders is operated You may let them. In the latter case, for example, as described above, a better braking effect can be obtained in a vehicle in which regenerative braking is performed on the left and right front wheels.
In the hydraulic brake system of this section, one valve control unit that operates is compared with a case where both the first and second valve control units operate, and a left valve device that is controlled by the one valve control unit and There may be provided a one-system operating control change unit for controlling the left valve device and the right valve device so as to increase the hydraulic pressures of the left and right brake cylinders whose hydraulic pressures are controlled by the right valve device, respectively.
(7) an ignition switch provided between the power supply device and the valve control device;
A closed state maintaining unit that maintains the first and second master cut valves in a closed state as long as the brake operation member is operated for a set time after the ignition switch is switched from the ON state to the OFF state; The hydraulic brake system according to any one of (3) to (6).
For example, after the ignition switch is switched from the ON state to the OFF state, the set time is usually set to a time slightly longer than the time until the driver finishes the operation of the brake operation member. Therefore, for example, if the brake operation member is a brake pedal, the first and second master cut valves can be operated in a state where the brake pedal is depressed if the driver releases the brake pedal before the set time elapses. It will not be opened and kickback will be avoided. Since the first and second master cut valves are controlled by the same valve control unit, in order to maintain the first and second master cut valves in the closed state after the ignition switch is switched from the ON state to the OFF state. Of the first and second valve control units, it is only necessary to supply current to the valve control unit that controls the opening and closing of the first and second master cut valves, while saving current consumption. It is possible to keep the cut valve closed and avoid the occurrence of kickback.

(8) a master cylinder that generates the same hydraulic pressure in the first pressurization chamber and the second pressurization chamber independent according to the operation of the brake operation member;
A power hydraulic pressure source that generates hydraulic pressure by power,
A left front brake cylinder, a right front brake cylinder, a left rear brake cylinder and a right rear brake cylinder provided on each of the front, rear, left and right wheels;
A first master provided in each of a first master cylinder passage and a second master cylinder passage that connect each of at least one of the four brake cylinders and each of the first and second pressure chambers independently of each other. A cut valve and a second master cut valve;
A power pressure passage connecting the power hydraulic pressure source and each of the four brake cylinders, and a left front valve device, a right front valve device, and a left rear valve device provided in them for independently controlling the hydraulic pressure of each brake cylinder And a right rear valve device,
A first valve control unit for controlling at least one of the left front valve device and the right front valve device, at least one of the first master cut valve and the second master cut valve, the left rear valve device and the right rear A hydraulic brake system comprising: a valve control device including at least one of a valve device and a second valve control unit that controls the other of the first master cut valve and the second master cut.
In this hydraulic brake system, the configuration of the piping connecting the first and second pressurizing chambers of the master cylinder and the brake cylinder is configured in the same manner as the hydraulic brake system described in (1), for example.
In this hydraulic brake system, the valve control device includes a front-rear electric braking control in which the first valve control unit controls the left front valve device and the right front valve device, and the second valve control unit controls the left rear valve device and the right rear valve device. Alternatively, one of the first valve control unit and the second valve control unit controls the left front valve device and the right rear valve device, and the other performs cross electric braking control for controlling the right front valve device and the left rear valve device.
Both the first and second master cut valves may be controlled by the first valve control unit or the second valve control unit, one is controlled by the first valve control unit, and the other is controlled by the second valve control unit. It may be controlled.
The first valve control unit controls any two of the left front, right front, left rear and right rear valve devices, and at least one of the first master cut valve and the second master cut valve, and the second valve control unit Can be considered to control another two of the left front, right front, left rear and right rear valve devices and the other of the first master cut valve and the second master cut valve. The hydraulic brake system described in each of the items is included in the hydraulic brake system described in this item.
The characteristics described in the items (3) to (7) can be adopted for the hydraulic brake system of this item regardless of the characteristics of the items (1) and (2). For example, the feature described in the item (5) can be adopted in a hydraulic brake system in which the valve control device performs cross electric braking control. For example, in a hydraulic brake system in which both piping and electric braking control are crossed, current is supplied to one of the first and second valve control units to be operated, and current is not supplied to the other and cannot be operated. The hydraulic pressures of the left and right brake cylinders belonging to the system to which current is supplied are made higher than when current is supplied to both the first and second valve control units. When cross electric braking control is performed, for example, in a state in which only one system is operated for various reasons, such as a state in which current is supplied from the sub power supply, or one of the two systems is abnormal. The left and right valve devices are controlled so that the braking force obtained by the operation of the front or rear left brake belonging to the operating system is the same as the braking force obtained by the operation of the rear or front right brake. Is done. It can be considered that a front-rear braking force identical control unit is provided. Even when the control change unit is provided, the control is changed on the premise of this, and the hydraulic pressures of the left and right brake cylinders are increased. In this case, it can be considered that the front and rear braking force identical control unit includes a control increase unit as a control change unit. The front / rear braking force identical control unit may increase the braking force, decrease it, or leave it as it is.
In the hydraulic brake system in which both the first and second master cut valves are controlled by the first valve control unit or the second valve control unit, for example, a hydraulic brake system in which the valve control device performs cross electric braking control. It is possible to adopt the features described in (7). After the ignition switch is turned OFF, the set time current is continuously supplied to the valve control unit that controls the first and second master cut valves. When the ignition switch is switched from the ON state to the OFF state, the vehicle is normally stopped, and when the brake operation member is in the operation state, the magnitudes of the braking forces of the plurality of brake cylinders are different. It seems that there is no hindrance. For this reason, it is not indispensable to provide the same control unit for the front and rear braking force so that the braking force of the two brakes belonging to the system maintained in the current supply state after the ignition switch is switched to the OFF state is the same. While generating a braking force based on the operation of the operating member, current consumption can be saved and the occurrence of kickback can be avoided.
(9) The valve control device includes at least the power hydraulic pressure source, the first and second master cut valves, the left front, right front, left rear, right rear valve device, and an electric braking control system including the valve control device. One system in which one of the first valve control unit and the second valve control unit is operated but the other is not operated in a normal state and the operation amount of the brake operation member is equal to or less than a set value The hydraulic brake system according to item (8), including an operation control unit.
In the hydraulic brake system of this section, even if the electric brake control system is normal and all the hydraulic pressures of the four brake cylinders can be electrically controlled, the operation amount of the brake operation member is In a state below the set value, only one of the two electric control systems is operated, for example, so that current consumption can be suppressed.
When either one of the first and second valve control units is operated, the one-system operation control unit may be a one-operation type one-system operation control unit, and only one set in advance may be operated. Both may be used as the system operation control unit. When both are used, the first and second valve control units are selectively operated by using the both-selection-use single system operation control unit. For example, the first valve control unit and the second valve control unit may be operated alternately, or may be operated alternately by a preset period. The same applies to the hydraulic brake system described in item (6).
When the valve control device performs front-rear electric braking control, if the first valve control unit and the second valve control unit are selectively operated, the braking effect obtained by the operation of the first valve control unit, and the second It is desirable to perform control so that the braking effect obtained by the operation of the valve control unit is the same. By doing so, for example, it is avoided that the occupant feels uncomfortable regardless of which valve control unit performs the control. The same applies to the hydraulic brake system described in item (6).
In addition, when the valve control device performs cross electric braking control, it belongs to the same system regardless of whether one of the first and second valve control units is operated or when two valve control units are selectively used. Control is performed so that the braking force obtained by operating the front wheel brake is the same as the braking force obtained by operating the rear wheel brake. At this time, if the first valve control unit and the second valve control unit are selectively operated, the braking effect obtained by the operation of the first valve control unit and the braking effect obtained by the operation of the second valve control unit. It is desirable to perform control so that the effect is the same.
(10) Compared with the case where both the first and second valve control units are operated, the one valve control unit is added to the valve control unit. There is provided a one-system operating control change unit for controlling the left and right valve devices so as to increase the hydraulic pressures of the left and right brake cylinders whose hydraulic pressures are controlled by the valve devices, respectively (9). Hydraulic brake system as described in
According to the hydraulic brake system of this section, during one system operation, the hydraulic pressures of the left and right brake cylinders, where the hydraulic pressure is increased by the left valve device and the right valve device controlled by one valve control unit, respectively, are controlled. It can be increased, and the shortage of braking force is suppressed while reducing current consumption.

  Several embodiments of the claimable invention will be described in detail below with reference to the drawings.

<First Example>
FIG. 1 conceptually shows a hydraulic brake system which is an embodiment of the claimable invention. In FIG. 1, reference numeral 10 denotes a left front wheel, 12 denotes a right front wheel, 14 denotes a left rear wheel, and 16 denotes a right rear wheel, and each includes a left front brake cylinder 20, a right front brake cylinder 22, a left rear brake cylinder 24, and a right rear brake cylinder. 26 is provided. In the present hydraulic brake system, the hydraulic pressure generated by the master cylinder 30 and the hydraulic pressure generated by the power hydraulic pressure source 32 are selectively applied to the left front brake cylinder 20 and the right front brake cylinder 22, respectively. The left front brake and the right front brake are actuated, and only the hydraulic pressure generated by the power hydraulic pressure source 32 is supplied to the left rear brake cylinder 24 and the right rear brake cylinder 26, respectively. The brake and the right rear brake are actuated.

  The master cylinder 30 includes a first pressurizing chamber 34 and a second pressurizing chamber 36 that are independent from each other, and the first and second pressurizing chambers 34, The same hydraulic pressure is generated at 36. This hydraulic pressure is called master cylinder pressure. The first pressurizing chamber 34 is connected to the left front brake cylinder 20 by a first front passage 40 as a first master cylinder passage, and the second pressurization chamber 36 is connected by the second front passage 42 as a second master cylinder passage. It is connected to the right front brake cylinder 22. The first and second front passages 40 and 42 independently connect the left front and right front brake cylinders 20 and 22 and the first and second pressurization chambers 34 and 36, respectively. One master cut valve 50 and a second master cut valve 52 are provided. In the present embodiment, the first and second master cut valves 50 and 52 are constituted by normally open electromagnetic on-off valves, which are opened in a state where no current is supplied to the solenoid, and the first and second pressurizing chambers 34. 36 and the left front and right front brake cylinders 20 and 22 are connected to each other and closed by supplying current to the solenoid, and the first and second pressure chambers 34 and 36 are connected to the left front brake cylinder 20 and the right front brake cylinder 22. Block communication. The piping configuration of the hydraulic brake system of the present embodiment is the front / front piping.

  The power hydraulic pressure source 32 includes a pump 60 and an accumulator 62 in this embodiment. The pump 60 is driven by a pump motor 64 which is an electric motor which is a kind of drive source, pumps brake fluid from a reservoir 66 through a reservoir passage 68, and the brake fluid discharged from the pump 60 is stored in an accumulator 62 under pressure. The power hydraulic pressure source 32 is a hydraulic pressure source that generates a hydraulic pressure by power by the operation of the pump motor 64. The pump 60 is actuated when the accumulator pressure, which is the fluid pressure of the accumulator 62 detected by the accumulator pressure sensor 70, falls below a set value, pumps up brake fluid from the reservoir 66, and stores it in the accumulator 62. It may be considered that the reservoir 66 also constitutes the power hydraulic pressure source 32. In addition, a relief valve 74 is provided for the accumulator 62. If the hydraulic pressure in the accumulator 62 exceeds the relief pressure, the relief valve 74 opens and the brake fluid is discharged from the accumulator 62 toward the reservoir 66, so that the accumulator pressure is appropriate. Maintained at height.

  The power hydraulic pressure source 32 and each of the four brake cylinders 20, 22, 24, and 26 are connected by power pressure passages 80, 82, 84, and 86, and the pump 60 and the accumulator 62 are connected to the brake cylinders 20 to 26. ing. The power pressure passages 80 and 82 are connected to portions of the first and second front passages 40 and 42 between the first and second master cut valves 50 and 52 and the brake cylinders 20 and 22. It can also be considered that a part of the first and second front passages 40, 42 constitutes a part of the power pressure passage. In this embodiment, each of these power pressure passages 80 to 86 is branched in the middle to be provided with pressure reduction passages or return passages 90, 92, 94, 96, and connected to a reservoir passage 68, and brake cylinders 20 to 26 are provided. Each brake fluid is returned to the reservoir 66. A left front valve device 100, a right front valve device 102, a left rear valve device 104, and a right rear valve device 106 are provided in each of the power pressure passages 80, 82, 84, and 86. In the present embodiment, these valve devices 100 to 106 include a pressure increasing electromagnetic valve 108 and a pressure reducing electromagnetic valve 110, respectively, and control the brake cylinder pressure, which is the hydraulic pressure of the brake cylinders 20 to 26, independently of each other.

  In the present embodiment, both the pressure increasing solenoid valve 108 and the pressure reducing solenoid valve 110 are linear solenoid valves. The pressure-increasing electromagnetic valves 108 of the valve devices 100 to 106 are respectively provided in portions of the power pressure passages 80 to 86 between the power hydraulic pressure source 32 and the brake cylinders 20 to 26, and accumulator pressure is controlled by controlling the supply current. Is controlled to an appropriate height and supplied to the brake cylinders 20-26. The pressure reducing solenoid valves 110 of the valve devices 100 to 106 are provided in the return passages 90 to 96, respectively, and allow the brake fluid to flow from the brake cylinders 20 to 26 to the reservoir 66, thereby reducing the brake cylinder pressure. Let By controlling the supply current to the pressure reducing solenoid valve 110, the brake cylinder pressure is reduced to an appropriate height. In the present embodiment, all of the four pressure increasing solenoid valves 108 are normally closed valves. Of the four pressure reducing electromagnetic valves 110, the pressure reducing electromagnetic valves 110 of the left front valve device 100 and the right front valve device 102 are normally closed valves, and the pressure reducing valves of the left rear valve device 104 and the right rear valve device 106 are respectively closed. The solenoid valve 110 is a normally open valve. Further, in this embodiment, the components shown in the frame indicated by the two-dot chain line such as the power hydraulic pressure source 32, the first and second master cut valves 50 and 52, and the valve devices 100 to 106 are integrated with each other. As a result, the brake actuator 120 is constructed.

  The power hydraulic pressure source 32, the first and second master cut valves 50 and 52, the valve devices 100 to 106, and the like are controlled by a valve control device 140. The valve control device 140 includes a first valve control unit 142 and a second valve control unit 144. As shown in FIG. 2, the first and second valve control units 142 and 144 are configured mainly with first and second computers 150 and 152, respectively. The first computer 150 includes a CPU 154, a ROM 156, a RAM 158, an input / output interface 160, and a bus connecting them. The input / output interface 160 is connected to the first and second master cut valves 50 and 52 via the drive circuit 162, the pressure increasing solenoid valves 108, the pressure reducing solenoid valves 110, and the pumps of the left front and right front valve devices 100 and 102. A motor 64 and a first relay 164 are connected. The first computer 150 and the drive circuit 162 jointly constitute the first valve control unit 142 to control the left front valve device 100, the right front valve device 102, the first and second master cuts 50, 52, and the like. A front wheel electric braking control system is configured together with the device 100 and the like. The first relay 164 will be described later.

  Further, the input / output interface 160 of the first computer 150 includes a step detection device as a brake operation detection device that detects depression of the brake pedal 38 and a kind of operation amount detection device that detects a depression stroke as an operation amount of a brake operation member. Master pressure sensors 182, 184, and four brake cylinders 20 to 26 that detect the master cylinder pressure generated in each of the stroke sensor 170, the first and second pressurizing chambers 34, 36 as a depression amount detecting device. Various sensors such as the brake cylinder pressure sensors 186, 188, 190, 192, the accumulator pressure sensor 70, etc. for detecting the brake cylinder pressure, which are each hydraulic pressure, are connected. In addition, although not shown, various detectors for performing normal braking control, antilock control, traction control, vehicle stability control, etc., such as a wheel speed sensor, an acceleration sensor, and a yaw rate sensor are connected. Input to the computer 150. Further, the detected values of the first voltmeter 194 and the second voltmeter 196 are input to the first computer 150. The first and second voltmeters 194 and 196 will be described later. Further, the first computer 150 and the second computer 152 are connected to each other and exchange information and the like by communication. The ROM 156 of the first computer 150 stores a main routine (not shown), a relay control routine, a front wheel braking force control routine, and the like shown in flowcharts in FIGS.

  As shown in FIG. 2, the second computer 152 includes a CPU 200, a ROM 202, a RAM 204, an input / output interface 206, and a bus for connecting them. The input / output interface 206 is connected to the pressure increasing solenoid valve 108, the pressure reducing solenoid valve 110, the pump motor 64, and the second relay 166 of the left rear and right rear valve devices 104 and 106 via the drive circuit 208. . The second computer 152 and the drive circuit 208 together constitute the second valve control unit 144, and control the left rear valve device 104, the right rear valve device 106, and the like. This control system is referred to as a rear wheel electric braking control system. In the present hydraulic brake system, the hydraulic pressures of the four brake cylinders 20 to 26 are controlled separately in two front and rear systems in terms of electric braking control. The ROM 202 of the second computer 152 stores a main routine (not shown), a relay control routine, a rear wheel braking force control routine, and the like shown in flowcharts in FIGS. 3 and 5, respectively. The second relay 166 will be described later.

  Further, the input / output interface 206 of the second computer 152 is similar to the first computer 150, such as a stroke sensor 170, a wheel speed sensor, an acceleration sensor, a yaw rate sensor, etc., normal braking control, antilock control, traction control, Various detectors for vehicle stability control and the like are connected.

  As shown in FIG. 1, the hydraulic brake system further includes a power supply device 228 including a main power supply 220 and a sub power supply 222. The main power supply 220 supplies current to the first and second valve control units 142 and 144, and the sub power supply 222 supplies current to the main power supply 220 that supplies current to the first and second valve control units 142 and 144, respectively. Connected to each of the supply lines, diodes 230 and 232 are provided between each of the connecting portions and the main power supply 220, respectively. Therefore, in a state where the charge amount of the main power supply 220 is sufficient and the voltage is high, current is supplied from the main power supply 220 to the first and second valve control units 142 and 144 and current is also supplied to the sub power supply 222. When the main power supply 220 cannot supply current or is inappropriate, the sub power supply 222 supplies current to at least one of the first valve control unit 142 and the second valve control unit 144.

  The first and second valve control units 142 and 144 operate when current is supplied from the main power supply 220, but current required for control may not be supplied from the main power supply 220. For example, if the main power supply 220 breaks down or the line is disconnected, the current supply becomes impossible, or even if there is no failure, for example, the current consumption in the vehicle equipped with the hydraulic brake system is large. A large amount of current may be consumed at one time, and the supply current may be insufficient, resulting in an unsuitable state for current supply. In any case, since the current is insufficient for the first and second control units 142 and 144 to operate normally, the current is supplied from the sub power source 222.

  As shown in FIG. 1, the main power supply 220 and the sub power supply 222 both supply current to the first valve control unit 142 via the first relay 164 and to the second valve control unit 144 via the second relay 166. Supply current. The first and second relays 164 and 166 which are electrical circuit switching devices are always opened in a return state (OFF state) which is a non-energized state of the coil and closed in an operating state (ON state) where the coil is energized. It is an open circuit type. The voltage of the main power supply 220 is detected by the first voltmeter 194, and by comparing the detected voltage with a set value, it can be determined whether the voltage of the main power supply 220 is incapable of supplying current or in an inappropriate state.

  The main power supply 220 is also configured to supply current to the first and second valve control units 142 and 144 without passing through the first and second relays 164 and 166, and the ignition switch 224 is connected to the current supply line. Is provided. The second voltmeter 196 detects the voltages on the first and second valve control units 142 and 144 side from the ignition switch 224, and based on the detected voltage, the ignition switch 224 is switched to the ON state or OFF. You can see if it is switched to the state. In this embodiment, the current supplied from the main power supply 220 when the ignition switch 224 is switched to the ON state is supplied to the computers 150 and 152 of the first and second valve control units 142 and 144, and the computers 150 and 152 are actuated, and various actuating devices such as solenoid valves that are driven and controlled by the drive circuits 162 and 208 are supplied by switching the first and second relays 164 and 166 to the ON state. Operates with current. The computers 150 and 152 are also activated by the current supplied when the first and second relays 164 and 166 are switched to the ON state.

Next, the operation will be described.
In the present hydraulic brake system, normally, the brakes of the four wheels are operated based on the hydraulic pressure generated in the power hydraulic pressure source 32 to suppress the rotation of the wheels. In the left front and right front brake cylinders 20, 22, the first and second master cut valves 50, 52 are not closed at the beginning of the depression of the brake pedal 38, and the first and second pressure chambers 34, 36 of the master cylinder 30 are not closed. The brake fluid is supplied from and the first fill is performed. The first fill is performed until the set condition is satisfied, for example, until the hydraulic pressures of the left front and right front brake cylinders 20 and 22 become equal to or higher than the set pressure. After the first fill is finished, the first and second master cut valves 50 and 52 are closed, and the left front and right front brake cylinders 20 and 22 are disconnected from the first and second pressurizing chambers 34 and 36, and the power The hydraulic pressure is supplied from the hydraulic pressure source 32.

  The first valve control unit 142 is requested by the driver based on the depression stroke detected by the stroke sensor 170 and the hydraulic pressures of the left front and right front brake cylinders 20, 22 detected by the brake cylinder pressure sensors 186, 188. The left front and right front valve devices 100 and 102 are controlled so that the braking force to be obtained is obtained, and the hydraulic pressures of the left front and right front brake cylinders 20 and 22 are controlled. If the control by the first valve control unit 142 is schematically described, if the main power supply 220 is neither incapable of supplying current nor inadequate in supplying current, if both the front wheel and rear wheel electric braking control systems are normal, Normal control is performed. In the normal control, it is assumed that the front wheel electric brake control system and the rear wheel electric brake control system are both normal, and the four brake cylinders are provided so that the braking force required by the driver is obtained based on the depression stroke of the brake pedal 38. The target hydraulic pressure is set for each of 20 to 26, and the left front and right front valve devices 100 and 102 are operated so that the target hydraulic pressure is obtained for the left front and right front brake cylinders 20 and 22, respectively. At this time, the first and second master cut valves 50 and 52 are closed, but these are closed after the first fill is completed. The pump motor 64 is operated as necessary.

  If the front wheel electric braking control system is abnormal, a control end process of the front wheel electric braking control system is performed. In the control end process, for example, the process of returning the current to the various electromagnetic valves belonging to the front wheel electric braking control system to return to the normal state is performed. Therefore, the first and second master cut valves 50 and 52 are opened. If the pump motor 64 is operated, it is stopped. The pump motor 64 may be operated until the accumulator pressure becomes a set value or more. If the rear wheel electric braking control system is operated, the pump motor 64 is operated by the second valve control unit 144. If the front wheel electric braking control system is normal but the rear wheel electric braking control system is abnormal, front wheel braking force increase control for increasing the front wheel braking force is performed, and the left and right rear wheel brakes do not operate, resulting in insufficient control. Power is supplemented by left and right front wheel brakes. In this embodiment, the front wheel braking force is increased so as to generate all of the rear wheel braking force that is generated if the left and right rear wheel brakes are operated if the stepping stroke is equal to or less than the set value. When it is larger than the set value, the braking force is increased as much as possible in the front wheel electric braking control system according to the depression stroke. When the front wheel braking force increase control is performed, the first and second master cut valves 50 and 52 are normally closed, but if they are still open, they are closed.

  When the main power supply 220 cannot supply current or is inadequate to supply current, current is supplied from the sub-power supply 222, whereby both the front wheel and rear wheel electric braking control systems can operate, and the main power supply 220 is activated. It can be considered that the power supply device 228 is normal regardless of whether the current is supplied from the sub power source 222 or the current is supplied from the sub power source 222. In a state where current is supplied from the auxiliary power source 222, in order to save current consumption, in principle, only one of the two electric braking control systems, in this embodiment, current is supplied and operated. Be made. In this hydraulic brake system, regardless of whether the electric braking control system for the front and rear wheels is normal or abnormal, the depression stroke is less than the set value and the braking force requested by the driver is not large. In this case, the second relay 166 is turned off, the first relay 164 is kept on, current is supplied to the first valve control unit 142, and only the front wheel electric braking control system is operated. The Therefore, when the electric control system including the power supply device 228, the front wheel and the rear wheel electric braking control system is normal and the stepping stroke is equal to or less than the set value, the first valve control unit 142 is operated. The valve control unit 144 is not operated.

  When only the front wheel electric braking control system is operated in this way, the front wheel braking force increase control is performed so that the front wheel braking force is increased by the amount that the rear wheel electric braking control system is not operated. In this case, if the stepping stroke is less than the set value, the front wheel braking force increase control increases the front wheel braking force so as to generate all of the rear wheel braking force that is generated if the left and right rear wheel brakes are operated. The hydraulic pressures of the left front and right front brake cylinders 20 and 22 are increased as compared with a state in which current is supplied from the main power supply 220 to the first and second valve control units 142 and 144. Further, when the stepping stroke is larger than the set value and the driver's required braking force is large, normal control is performed. In this case, a current is also supplied to the rear wheel electric braking control system so that the hydraulic pressure is also supplied to the left rear and right rear brake cylinders 24 and 26. However, if the rear wheel electric braking control system is abnormal, front wheel braking force increase control is performed. Also in these cases, if the front wheel electric braking control system is abnormal, the control end processing is performed, and the left and right front wheel brakes are the first and second brakes of the master cylinder 30 regardless of whether the stepping stroke is larger or smaller than the set value. It is actuated by the hydraulic pressure generated in the pressurizing chambers 34 and 36 and functions as a manual brake.

  The hydraulic control of the left front and right front brake cylinders 20 and 22 has been described above. Next, in the normal control in which each brake of the four wheels is operated based on the hydraulic pressure generated in the power hydraulic pressure source 32. The control of the left rear and right rear brake cylinders 24 and 26 will be described. In this case, when the brake pedal 38 is depressed, the hydraulic pressure is immediately supplied from the power hydraulic pressure source 32 to the left rear and right rear brake cylinders 24 and 26, respectively. The second valve control unit 144 controls the left rear valve device 104, the right rear valve device 106, and the like, and controls each hydraulic pressure of the left rear and right rear brake cylinders 24 and 26.

  In the second valve control unit 144, in a state where the main power supply 220 is neither incapable of supplying current nor inadequate in supplying current, normal control is performed if the rear wheel electric braking control system is normal, and the rear wheel electric braking control system is If it is abnormal, rear wheel control end processing is performed. Further, when the main power supply 220 cannot supply current or is inappropriate, the stepping stroke is larger than the set value, and the normal control is performed when the rear wheel electric braking control system is normal. In the following cases, rear wheel control end processing is performed. This is because, in the state where current is supplied from the sub power source 222 as described above, only the left and right front wheel brakes are operated in a state where the stepping stroke is equal to or less than the set value in order to save current consumption. If the front wheel electric braking control system is abnormal when the stepping stroke is less than or equal to the set value, the front wheel electric braking control is terminated and the second relay 166 is turned off. The braking control system is also not activated. Although the left and right rear wheel brakes do not operate and the left and right front wheel brakes function as manual brakes, there is no problem because the required braking force is not so large. In the relay control routine, when the stepping stroke is equal to or less than the set value, it is determined whether the front wheel electric braking control system and the rear wheel electric braking control system are normal or abnormal, and the front wheel electric braking control system is abnormal. However, when the rear wheel electric braking control system is normal, the second relay 166 may be turned on so that the left and right rear wheel brakes are actuated. In this case, the hydraulic pressures of the left rear and right rear brake cylinders are normally controlled. The rear wheel braking force may be increased.

  In the normal control, it is assumed that the front wheel electric brake control system and the rear wheel electric brake control system are both normal, and the four brake cylinders are used so that the braking force required by the driver is obtained based on the depression stroke of the brake pedal 38. The target hydraulic pressure is set for each of 20 to 26, and the left rear and right rear valve devices 104 and 106 are operated so as to obtain the target hydraulic pressure for the left rear and right rear brake cylinders 24 and 26. The pump motor 64 is also operated as necessary. In the control end process, the current supply to the electromagnetic valves 108 and 110 of the left rear and right rear valve devices 104 and 106 is shut off, and the pump motor 64 is stopped. The pump motor 64 may be operated until the accumulator pressure becomes a set value or more. The pump motor 64 is driven by the first valve control unit 142 as necessary.

  Switching of the ON and OFF states of the first and second relays 164 and 166 is controlled by the first and second valve control units 142 and 144, respectively, and current is supplied from the main power supply 220 or from the sub power supply 222. Or in connection with the magnitude of the stepping stroke and the switching of the ignition switch 224. If this control is roughly explained, if the main power supply 220 cannot supply current or is not suitable, the second relay 166 is turned on, and the ignition switch 224 that is switched from the OFF state to the ON state is turned off. Waiting to be switched to the state. When the main power supply 220 is in a state where current supply cannot be performed or is inappropriate and the stepping stroke is equal to or less than the set value, only the front wheel electric braking control system is operated, so the second relay 166 is switched to the OFF state, and the stepping stroke Is larger than the set value, the second relay 166 is switched to the ON state and normal control is performed, and both the front wheel electric braking control system and the rear wheel electric braking control system are operated.

  If the ignition switch 224 is switched from the ON state to the OFF state, the second relay 166 is immediately turned OFF, but the first relay 164 is kept ON for the set time. The first valve control unit 142 maintains a state in which current is supplied to itself including the first computer 150 for the set time, the front wheel electric braking control system is operable, and the brake pedal 38 is depressed. Then, the first valve control unit 142 can keep the first and second master cut valves 50 and 52 closed, and can prevent the kickback from occurring. The first and second master cut valves 50 and 52 allow or block the communication between the first and second pressurizing chambers 34 and 36 and the left front and right front brake cylinders 20 and 22, and the left front and right front brake cylinders. 20 and 22 is controlled by the first valve control unit 142 that controls each hydraulic pressure, belongs to the front wheel electric braking control system, is collectively controlled by the first valve control unit 142, and the ignition switch 224 is switched to the OFF state. After that, only the first valve control unit 142 that controls the first and second master cut valves 50 and 52 is maintained in a state where current is supplied, thereby saving current consumption and preventing kickback. Is done. The first computer 150 may be operated by, for example, battery power backup until the first relay 164 is turned off after the ignition switch 224 is turned off.

Control by the first and second valve control units 142 and 144 will be described based on a flowchart.
First, the relay control routine will be described based on the flowchart shown in FIG. The relay control routine is stored in the ROMs 156 and 202 of the first and second computers 150 and 152, and is executed by the computers 150 and 152, respectively. However, since the first relay 164 is controlled by the first computer 150 and the second relay 166 is controlled by the second computer 152, one of the plurality of steps constituting the relay control routine and the contents of the steps in one computer. Is executed effectively, but there are steps and contents of steps that are invalid when executed on the other computer. It can be considered that the first and second computers 150 and 152 execute the relay control routine jointly. In the first computer 150, a relay control routine and another routine executed by the first computer 150, such as a front wheel braking force control routine (see FIG. 4), are executed for each unit time by time division control. The routine starts from the continuation of the process that was being executed at the end of the previous execution. The same applies to the second computer 152.

  The relay control routine is started when the ignition switch 224 is switched from the OFF state to the ON state. In step 1 of the relay control routine (hereinafter abbreviated as S1. The same applies to other steps), current supply commands to the coils of the first and second relays 164 and 166 are output. The two relays 164 and 166 are turned on and closed. Since the first relay 164 is controlled by the first computer 150 and the second relay 166 is controlled by the second computer 152, the first and second computers 150 and 152 are respectively the first and second relays 164 in S1. , 166 outputs a current supply command to each coil, but for the first computer 150, the current supply command to the coil of the second relay 166 is invalid, and for the second computer 152, the coil of the first relay 164 The current supply command to is invalid.

  Next, S2 is executed and it is determined whether or not the voltage of the main power supply 220 is equal to or lower than a set value. It is determined whether or not the main power supply 220 is in a state where current supply is not possible or current supply is inappropriate. This determination is made based on the detection voltage of the first voltmeter 194, and if it is larger than the set value, the main power supply 220 is not in a state where current cannot be supplied or is not suitable for current supply, and the determination result in S2 is NO. S3 is executed and the second relay 166 is turned on, and then S4 is executed to determine whether or not the ignition switch 224 is OFF. If the ignition switch 224 is in the ON state, the determination result in S4 is NO and S2 is executed. While the voltage of the main power source 220 is larger than the set value and the ignition switch 224 is switched to the ON state, S2 to S4 are repeatedly executed.

  If the voltage of main power supply 220 is equal to or lower than the set value, the determination result in S2 is YES, S5 is executed, and it is determined whether the stepping stroke is equal to or lower than the set value. It is determined whether or not the braking force requested by the driver is large. If the stepping stroke is equal to or less than the set value, the determination result in S5 is YES, S6 is executed, and the second relay 166 is A current supply cutoff command to the coil is output, and the second relay 166 is turned off and opened. As a result, no current is supplied to the second valve control unit 142, and the left and right rear wheel brakes do not operate. When the determination of S5 is executed, the voltage of the main power source 220 is equal to or lower than the set value, the sub power source 222 is in a state of supplying current, the stepping stroke is equal to or lower than the set value, and the driver intends When the braking force is not large, it is sufficient to operate only the left and right front wheel brakes, and the current consumption of the auxiliary power source 222 is saved by not operating the left and right rear wheel brakes.

  On the other hand, if the depression stroke is larger than the set value, the determination result of S5 is NO, S7 is executed, and the second relay 166 is turned on. Therefore, for example, if the stepping stroke is less than the set value and the second relay 166 is in the OFF state, it is switched to the ON state, and the left and right front wheel brakes are operated together with the left and right front wheel brakes. The intended large braking force can be obtained. Even when the voltage of the main power supply 220 is low and current is supplied from the sub power supply 222, S4 is executed after the execution of S6 or S7. And while the voltage of the main power supply 220 is low, S2, S5, S6, S4 or S2, S5, S7, S4 are repeatedly executed. Even if the second relay 166 is turned off in S6, if the voltage of the main power supply 220 becomes higher than the set value after charging, S3 is executed and the second relay 166 is turned on.

  Since the first and second voltmeters 194, 196 and the stroke sensor 170 are connected to both the first and second computers 150, 152, S2, S4 and S5 are effectively executed in both computers 150, 152. . On the other hand, the current supply command and the current cutoff command to the coil of the second relay 166 in S3, S6, and S7 are valid commands in the second computer 152 and invalid commands in the first computer 150.

  If the ignition switch 224 is switched from the ON state to the OFF state, the determination result in S4 is YES, S8 is executed, the second relay 166 is switched to the OFF state, and the self-holding timer is started. The command for switching the second relay 166 to the OFF state is a valid command in the second computer 152 and an invalid command in the first computer 150. When the second relay 166 is turned off, no current is supplied to the second valve control unit 144, the second valve control unit 144 and the rear wheel electric braking control system do not operate, and the electromagnetic valve is in a normal state. Return to. The start of the self-holding timer is effectively executed in the first computer 150. In the second computer 152, even if the self-holding timer is started before the second relay 166 is turned off, if the second relay 166 is switched to the off state, the timing stops, and as a result It becomes invalid. If the second relay 166 is turned off first in the second computer 152, the self-holding timer is not started. The second computer 152 may not be provided with a self-holding timer, and in the second computer 152, the self-holding timer start command may be an invalid command.

  The self-holding timer keeps the first relay 164 in the ON state after the ignition switch is turned off, and measures the time during which the first valve control unit 142 keeps itself in an operable state. If the first relay 164 is maintained in the ON state even after the ignition switch is turned off, if the current is supplied to the first valve control unit 142 and the brake pedal 38 is depressed, the first and second master cuts are performed. Valves 50 and 52 are kept closed. The pressure increasing solenoid valve 108 and the pressure reducing solenoid valve 110 of the front wheel electric braking control system are kept closed in a state where a brake cylinder pressure corresponding to the depression stroke of the brake pedal 38 is obtained.

  Next, S9 is executed, and it is determined whether or not the time counted by the self-holding timer has exceeded a set time, for example, 120 seconds. It is determined whether or not a set time has elapsed after the ignition switch is turned off. S9 is repeatedly executed until the set time elapses. When the set time elapses, the determination result in S9 is YES, S10 is executed, and the first relay 164 is turned off. As a result, the current supply to the first valve control unit 142 is interrupted.

  The set time is normally set longer than the time until the driver releases the brake pedal 38 after the ignition switch 224 is switched to the OFF state. Therefore, when the ignition switch 224 is switched from the ON state to the OFF state, it is normal that the brake pedal 38 is depressed, the brake is operated, and the brake cylinder pressure is generated. The first and second master cut valves 50 and 52 are maintained in the closed state until the person steps down from the brake pedal 38, and the first and second masters are in a state where the driver is stepping on the brake pedal 38. It is avoided that the cut valves 50 and 52 are opened and the brake cylinder pressure acts on the pressurizing piston of the master cylinder 30 to push back the brake pedal 38 and cause kickback. The first and second master cut valves 50 and 52 are both included in the front wheel electric braking control system, and in order to keep both of them closed, a current is supplied only to the first relay 164 to control the first valve. It is sufficient that only the part 142 is activated, and the occurrence of kickback can be prevented while saving current consumption. The braking control is terminated when the brake pedal 38 is released or the current supply is interrupted by turning off the relay. When the ignition switch 224 is switched from the ON state to the OFF state, the depression of the brake pedal 38 may be released and the braking control may be terminated. In this case, S8 to S10 are similarly executed. . In the second computer 152, since the second relay 166 is turned off in S8, the second computer 152 does not operate and S9 and S10 are not executed.

  Front wheel braking force control will be described based on the flowchart shown in FIG. In this routine, it is first determined in S21 whether or not the brake pedal 38 is depressed. This determination is made based on the detection value of the stroke sensor 170. If the detected value of the stroke sensor 170 is not a value representing the depression of the brake pedal 38 and the brake pedal 38 is not depressed, the determination result in S21 is NO and S26 is executed, and the front wheel electric braking control end process is completed. Done.

  If the detected value of the stroke sensor 170 is a value representing the depression of the brake pedal 38, and the brake pedal 38 is depressed, the determination result of S21 is YES, S22 is executed, and the voltage of the main power supply 220 is set to the set value. It is determined whether or not: If the voltage of main power supply 220 is greater than the set value, the determination result in S22 is NO and S23 is executed to determine whether or not the rear wheel electric braking control system is abnormal. In each of the first and second computers 150 and 152, an abnormality detection program (not shown) is executed, and whether or not there is any abnormality in all the constituent elements including itself and used for execution of electric braking control. Are detected, and the detection results are communicated with each other by communication. The determination in S23 is made based on the abnormality detection result transmitted from the second computer 152. If there is no abnormality in the rear wheel electric braking control system and it is normal, the determination result in S23 is NO and S24 is It is executed and it is determined whether or not the front wheel electric braking control system is abnormal. This abnormality is detected by the first computer 150, and if it is not abnormal, the determination result in S24 is NO, S31 is executed, and normal control is performed.

  If the rear wheel electric braking control system is normal but the front wheel electric braking control system is abnormal, the determination result in S23 is NO, the determination result in S24 is YES, and S26 is executed. In this case, the driver has depressed the brake pedal 38, and the first and second master cut valves 50, 52 are opened by the end processing of the front wheel electric braking control in S26, and the left front and right front brake cylinders 20, The hydraulic pressure generated in the first and second pressurizing chambers 34 and 36 of the master cylinder 30 is supplied to 22, and the left and right front wheel brakes function as manual brakes.

  If the rear wheel electric braking control system is abnormal, the determination result in S23 is YES and S25 is executed to determine whether the front wheel electric braking control system is abnormal. If the front wheel electric braking control system is normal, the determination result in S25 is NO and S32 is executed, and front wheel braking force increase control is performed when the rear wheel electric braking control system is abnormal. In this case, the rear wheel electric braking control system is abnormal, the left and right rear wheel brakes are not actuated, and braking is performed only by the left and right front wheel brakes, so that the braking force is increased accordingly. In this case, the increased braking force to be increased in the front wheel electric braking control system is increased as much as possible by the left and right front wheel brakes according to the depression stroke. In this hydraulic brake system, there are two front and rear electric braking control systems. When the rear wheel electric braking control system is abnormal and cannot be operated, only the front wheel braking control system is operated. , 12 are operated, so that no yaw moment is generated in the vehicle, and braking is performed while maintaining running stability. If both the rear wheel electric brake control system and the front wheel electric brake control system are abnormal, the determination results in S23 and S25 are both YES, S26 is executed, and the front wheel electric brake control is terminated.

  If the voltage of main power supply 220 is equal to or lower than the set value, the determination result in S22 is YES and S27 is executed to determine whether or not the front wheel electric braking control system is abnormal. If the front wheel electric braking control system is abnormal, the determination result in S27 is YES, S26 is executed, and the control of the front wheel electric braking control system is terminated. If the front wheel electric braking control system is normal, the determination result in S27 is NO and S28 is executed, and it is determined whether or not the depression stroke of the brake pedal 38 is equal to or less than the set value. If the depression stroke is less than or equal to the set value, the determination result in S28 is YES, S29 is executed, and front wheel braking force increase control is performed. If the voltage of the main power supply 220 is equal to or lower than the set value, current is supplied from the sub power supply 222. However, as described in the relay control routine, the voltage of the main power supply 220 is equal to or lower than the set value and the stepping stroke Is equal to or less than the set value, one of the two relays is turned off to save current consumption, and only one electric control system is operated. In this hydraulic brake system, the second relay 166 is turned off, the first relay 164 is kept on, only the front wheel electric braking control system is operated, and the left and right rear wheel brakes are not operated. The front wheel braking force is increased accordingly. In a state where current is supplied from the sub power source 222 to the first valve control unit 142, the first valve control unit 142 is in a state where current is supplied from the main power source 220 to the first and second valve control units 142 and 144. In comparison with the left front and right front valves, the hydraulic pressures of the left front and right front brake cylinders 20 and 22 are controlled to be higher by the left front and right front valve devices 100 and 102 controlled by the first valve control unit 142, respectively. The apparatus 100 and 102 are controlled. Since the front wheel electric braking control system is activated, the first and second master cuts 50 and 52 remain closed, and current consumption can be saved without causing kickback.

  On the other hand, if the stepping stroke is larger than the set value, the determination result in S28 is NO and S30 is executed to determine whether or not the rear wheel electric braking control system is abnormal. If the rear wheel electric braking control system is normal, the determination result in S30 is NO, S31 is executed, and normal control is performed. In this case, even when the braking force requested by the driver is large and current is supplied from the sub power source 222, the second relay 166 is turned on in the relay control routine, and rear wheel braking force control described below is performed. In the routine, the rear wheel electric braking control system is activated. The hydraulic pressures of the front, rear, left and right brake cylinders 20 to 26 are controlled by the valve devices 100 to 106, and the control is performed as usual, that is, in the same manner as when the voltage of the main power supply 220 is larger than the set value. If the rear wheel electric braking control system is abnormal, the determination result in S30 is YES and S32 is executed, and the front wheel braking force increase control is performed when the rear wheel electric braking control system is abnormal. In this case, the rear wheel electric braking control system is abnormal, the left and right rear wheel brakes are not operated, and only the left and right front wheel brakes are operated, so that the resulting braking force is increased.

The rear wheel braking force control routine will be described based on the flowchart shown in FIG.
This routine is executed by the second computer 152, and in S41, it is determined whether or not the brake pedal 38 is depressed. If the brake pedal 38 is not depressed, the determination result in S41 is NO, S47 is executed, and the rear wheel electric braking control end process is performed.

  If the brake pedal 38 is depressed, the determination result in S41 is YES, S42 is executed, and it is determined whether or not the voltage of the main power supply 220 is equal to or lower than a set value. If the voltage of main power supply 220 is greater than the set value, the determination result in S42 is NO and S43 is executed to determine whether or not the rear wheel electric braking control system is abnormal. If the rear wheel electric braking control system is normal, the determination result in S43 is NO, S44 is executed, and normal control is performed. Even if the front wheel electric braking control system is abnormal, the left and right front wheel brakes are operated and operated as manual brakes, and a front wheel braking force is obtained. Even if the front wheel electric braking control system is normal or abnormal, the front wheel braking force can be obtained.In this embodiment, when the main power supply voltage is larger than the set value and when the stepping stroke is larger than the set value, Regardless of whether the front wheel electric brake control system is normal or abnormal, the rear wheel electric brake control system is normally controlled if it is normal. When the rear wheel electric braking control system is normal, it is asked whether the front wheel electric braking control system is abnormal. If it is abnormal, the rear wheel braking force is increased as compared with the case where the front wheel electric braking control system is normal. Control may be performed. If the rear wheel electric braking control system is abnormal, the determination result in S43 is YES, S47 is executed, and the rear wheel electric braking control system is terminated.

  If the voltage of the main power supply 220 is equal to or lower than the set value, the determination result in S42 is YES, S45 is executed, and it is determined whether or not the depression stroke of the brake pedal 38 is equal to or lower than the set value. If the stepping stroke is less than or equal to the set value, the determination result in S45 is YES, S47 is executed, and the rear wheel electrical control is terminated. In this case, as described above in the relay control routine, the second relay 166 is switched to the OFF state, the second valve control unit 144 is not operated, and the rear wheel electric braking control system is not operated. Because. On the other hand, if the stepping stroke is larger than the set value, the determination result in S45 is NO and S46 is executed to determine whether or not the rear wheel electric braking control system is abnormal. If the rear wheel electric braking control system is normal, the determination result in S46 is NO, S44 is executed, and normal control is performed. In this case, since the stepping stroke is large and the braking force required by the driver is large, the left and right rear wheel brakes are also actuated to obtain the required braking force. Even if the depression stroke is larger than the set value, if the rear wheel electric braking control system is abnormal, the determination result in S46 is YES, S47 is executed, and the termination process is performed.

  As is apparent from the above description, in the present embodiment, the part that executes S5, S6 and S45, S47 of the second valve control unit 144 constitutes a one-system operation control unit, and the first valve control unit 142 The part that executes S8 to S10 constitutes a closed state maintaining part, the part that executes S29 constitutes a control change part, and the part that executes S29 and S32 constitutes a control change part during one-system operation. In addition, the first voltmeter 194 constitutes a main power supply current supply capability detection device, and the main power supply current is supplied together with the portions that execute S2 and S22 of the first valve control unit 142 and S2 and S42 of the second valve control unit 144. An impossible / unsuitable state determination unit is configured. Further, the second voltmeter 196 constitutes an ignition switch switching state detection device, and constitutes an ignition switch switching state determination unit together with the portion of the first valve control unit 142 that executes S4.

<Second Example>
Another embodiment of the claimable invention will be described with reference to FIGS.
In the hydraulic brake system of the present embodiment, the left front brake cylinder 20 and the right rear brake cylinder 26 are connected by a fluid passage 300, and the right front brake cylinder 22 and the left rear brake cylinder 24 are connected by a fluid passage 302. Thus, the master cylinder pressure is also supplied to the left rear and right rear brake cylinders 24 and 26. These liquid passages 300 and 302 are provided with electromagnetic on-off valves 304 and 306, respectively. These electromagnetic on-off valves 304 and 306 are both normally open valves. Further, the pressure increasing electromagnetic valve 312 and the pressure reducing electromagnetic valve 314 constituting the left rear valve device 308 and the right rear valve device 310 are both linear solenoid valves, and are normally closed valves. The electric brake control is performed in two systems, a front wheel electric brake control system and a rear wheel electric brake control system, as in the above embodiment, and the control of the front wheel electric brake control system is performed by the first valve control unit 316. Control of the rear wheel electric braking control system is performed by the second valve control unit 318. These first and second valve control units 316 and 318 constitute a valve control device 320. The electromagnetic on-off valves 304 and 306 are controlled by the second valve control unit 318 in the present hydraulic brake system. This hydraulic brake system has two front and rear systems in terms of electric braking control, but the pipe is a cross pipe.

  The braking force control in this hydraulic brake system is performed in substantially the same manner as in the hydraulic brake system of the above embodiment, and when both the front wheel electric brake control system and the rear wheel electric brake control system are normal, the electromagnetic on-off valve 304, 306 is closed and each hydraulic pressure of the brake cylinders 20 to 26 is controlled independently. The first fill is also performed for the left rear and right rear brake cylinders 24 and 26. The first fill may not be performed for the left rear and right rear brake cylinders 24 and 26. When the front wheel electric braking control system is normal but the rear wheel electric braking control system is abnormal, the current supply to the solenoids of the electromagnetic on-off valves 304 and 306 is cut off and opened. Therefore, the hydraulic pressures of the left rear and right rear brake cylinders are controlled in the same manner as the hydraulic pressures of the right front and left front brake cylinders, respectively. If the front wheel electric brake control system is abnormal but the rear wheel electric brake control system is normal, the control of the front wheel electric brake control system is terminated, and the master cylinder pressure is applied to the left front and right front brake cylinders 20 and 22. In the rear wheel electric braking control system, the electromagnetic on-off valves 304 and 306 are kept closed, and the hydraulic pressures of the left rear and right rear brake cylinders 24 and 26 are electrically controlled. When both the front wheel electric brake control system and the rear wheel electric brake control system are abnormal, the master cylinder pressure is supplied to any of the brake cylinders 20 to 26.

  Thus, even if the rear wheel electric braking control system is abnormal, the hydraulic pressure is supplied to the brake cylinders 24 and 26. Therefore, the rear wheel electric braking control system is abnormal and the front wheel electric braking control system is normal. In this case, the braking force increase control of the left and right front wheel brakes is not performed, and the hydraulic pressures of the left front and right front brake cylinders 20 and 22 are controlled as in the normal control so that the front wheel braking force corresponding to the depression stroke is obtained. For this reason, the left rear brake cylinder 24 and the right rear brake cylinder 26 are supplied with the same hydraulic pressure as the right front brake cylinder 22 and the left front brake cylinder 20, respectively. Since the rear wheel braking force is smaller than that of the cylinder, the rear wheel braking force is smaller than the front wheel braking force, and braking is performed without any problem.

  Therefore, as shown in FIG. 7, in the front wheel braking force control routine executed by the first valve control unit 316, the voltage of the main power supply 220 is larger than the set value, and the rear wheel electric braking control system is abnormal. However, if the front wheel electric braking control system is normal, the determination result in S63 is YES, the determination result in S65 is NO, S68 is executed, and normal control is performed. Even when both the rear wheel electric braking control system and the front wheel electric braking control system are normal, S68 is executed. Even when the voltage of the main power supply 220 is equal to or lower than the set value and the current is supplied from the sub power supply 222, normal control is also performed when the front wheel electric braking control system is normal.

  Although illustration and description are omitted, the relay control routine is a routine in which S6 is executed when S5 and S7 are not performed and the determination result of S2 is YES in the relay control routine shown in FIG. The rear wheel braking force control routine is a routine in which, in the rear wheel braking force control routine shown in FIG. 5, S45 and S46 are not executed, and if the determination result in S42 is YES, S47 is executed. In the relay control routine, when the main power supply voltage is lower than the set value, it is determined whether the front wheel electric braking control system and the rear wheel electric braking control system are normal or abnormal, and the front wheel electric braking control system is abnormal. However, when the rear wheel electric braking control system is normal, the second relay 166 may be turned on so that the rear wheel electric braking control system is operated. In this case, the hydraulic pressure of the left rear and right rear brake cylinders is normally controlled, but rear wheel braking force increase control may be performed.

  A stroke simulator device may be provided in the hydraulic brake system of each of the above embodiments. The stroke simulator device includes, for example, a stroke simulator and a normally closed electromagnetic on-off valve. This electromagnetic on-off valve is kept closed when the brake is actuated by the master cylinder pressure, and is opened when the master cut valve is closed and the brake cylinder pressure is controlled by the valve device. The simulator communicates with the pressurizing chamber of the master cylinder, giving the driver a feeling of operation.

  Further, when the operation amount of the brake operation member is not more than the set value when the main power source is not in a state where current supply is not possible or inadequate, either the front wheel or the rear wheel electric braking control system is operated, May not be operated. Regardless of whether or not the main power supply is in a state where current supply is not possible or inadequate, if the operation amount of the brake operating member is less than the set value, one of the first and second valve control units is It is also possible not to operate. In this case, for example, the configuration and piping of the electric braking control system of the hydraulic brake system are the same as those of the hydraulic brake system of the embodiment shown in FIGS. In this case, if the first valve control unit is operated, the relay control routine is, for example, a routine including S1, S4 to S10 in the relay control routine shown in FIG. 3, and S5 is executed after S1 is executed. To be done. Further, the front wheel braking force control routine is, for example, a routine including S21, S23 to S29, S31 and S32 in the front wheel braking force control routine shown in FIG. 4, and when the determination result in S21 is YES, S28 is executed. If the determination result in S28 is NO, S23 to S26, S31, and S32 are executed. If the determination result in S28 is YES, S27 and S29 are executed. Further, the rear wheel braking force control routine is, for example, a routine including S41, S43 to S45 and S47 in the rear wheel braking force control routine shown in FIG. 5, and if the determination result in S41 is YES, S45 is executed. If the determination result is YES, S47 is executed, and if NO, S43, S44 or S43, S47 is executed.

  Furthermore, when the main power supply is in a state where current supply is not possible or is inadequate, only one of the first and second valve control units is operated regardless of the amount of operation of the brake operation member. May be. In this case, for example, the relay control routine is a routine having steps excluding S5 and S7 in the relay control routine shown in FIG. 3, and when the determination result of S2 is YES, S7 is executed. .

  Further, it is not essential to perform the first fill for the brake cylinder of the front wheel at the start of operation of the brake operation member, and the brake fluid may be supplied immediately from the power hydraulic pressure source.

  Further, a brake switch may be provided to detect depression of the brake pedal, and a depression force sensor may be provided to detect the depression force that is the operation amount of the brake operation member.

  Further, the control unit that controls the electric braking control system including the master cut valve may control both the first and second relays, and the relay control routine may be executed only by the control unit.

  Further, instead of the diodes 230 and 232, a device that is electrically controlled to allow or cut off the connection between the sub power source and the main power source, and that is electrically controlled and includes the sub power source and the first and second valve control units. A device that allows and cuts off the connection and a control device that controls them are provided to cut off the connection between the main power supply and the valve control device and the sub power supply when the sub power supply is fully charged. When the value falls below the set value, the connection between the sub power supply and the main power supply may be cut off, and the sub power supply and the valve control device may be connected. The charging of the sub power supply is not limited to the current supply from the main power supply, and may be charged independently of the main power supply.

  Further, when the control change unit is provided, the hydraulic pressure of the left and right brake cylinders may be increased according to the operation amount of the brake operation member, and it is planned to be generated by the left and right brakes that cannot be operated. Of the braking force, the control can be changed in various manners, such as increasing the braking force at a preset rate so as to further generate the braking force.

  The claimable invention can also be applied to a hydraulic brake system having a piping configuration other than the above embodiments. For example, the claimable invention can be applied to a hydraulic brake system with two front and rear pipes. In this case, for example, one of the two valve control units controls the left front and right front valve devices and the two master cut valves. Let the other control the left rear and right rear valve devices, or let one of the two valve control units control the left front and right front valve devices, and let the other control the left rear and right rear valve devices and the two master cut valves .

  Although several embodiments of the claimable invention have been described in detail above, these are merely examples, and the claimable invention includes the aspects described in the above [Aspect of the Invention]. The present invention can be implemented in various forms based on the knowledge of the trader.

It is a circuit diagram showing roughly a hydraulic brake system which is one example of the claimable invention. It is a block diagram which shows roughly the structure of the valve control apparatus of the said hydraulic brake system. It is a flowchart which shows the relay control routine performed by the 1st, 2nd valve control part of the said valve control apparatus. It is a flowchart which shows the front-wheel braking force control routine performed by the said 1st valve control part. It is a flowchart which shows the rear-wheel braking force control routine performed by the said 2nd valve control part. It is a circuit diagram showing roughly a hydraulic brake system which is another example of the claimable invention. It is a flowchart which shows the front-wheel braking force control routine performed by the 1st valve control part of the hydraulic brake system shown in FIG.

Explanation of symbols

  10: Left front wheel 12: Right front wheel 14: Left rear wheel 16: Right rear wheel 20: Left front brake cylinder 22: Right front brake cylinder 24: Left rear brake cylinder 26: Right rear brake cylinder 30: Master cylinder 32: Power hydraulic pressure source 34: first pressurizing chamber 36: second pressurizing chamber 38: brake pedal 40: first front passage 42: second front passage 50: first master cut 52: second master cut valves 80, 82, 84, 86 : Power pressure passage 100: Left front valve device 102: Right front valve device 104: Left rear valve device 106: Right rear valve device 140: Valve control device 142: First valve control unit 144: Second valve control unit 220: Main power supply 222 : Sub power supply 224: Ignition switch 308: Left rear valve device 310: Right rear valve device 316: No. Valve control unit 318: second valve control unit 320: a valve control device

Claims (3)

A master cylinder that generates the same hydraulic pressure in the first pressurization chamber and the second pressurization chamber independent according to the operation of the brake operation member;
A power hydraulic pressure source that generates hydraulic pressure by power,
A left front brake cylinder, a right front brake cylinder, a left rear brake cylinder and a right rear brake cylinder provided on each of the front, rear, left and right wheels;
A first master provided in each of a first master cylinder passage and a second master cylinder passage that connect each of at least one of the four brake cylinders and each of the first and second pressure chambers independently of each other. A cut valve and a second master cut valve;
A power pressure passage connecting the power hydraulic pressure source and each of the four brake cylinders, and a left front valve device, a right front valve device, and a left rear valve device provided in them for independently controlling the hydraulic pressure of each brake cylinder And a right rear valve device,
A first valve control unit that controls one of the left front and right front valve devices, the left rear and right rear valve devices, the first and second master cut valves, the left front and right front valve devices, and the A hydraulic brake system comprising: a valve control device including a second valve control unit that controls the other of the left rear and right rear valve devices.   A first front passage and a second front passage, wherein the first master cylinder passage and the second master cylinder passage connect the left front and right front brake cylinders and the first and second pressure chambers independently of each other. The first valve control unit controls the left front and right front valve devices and the first and second master cut valves, and the second valve control unit controls the left rear and right rear valve devices. The hydraulic brake system according to claim 1, wherein the hydraulic brake system is provided. A power supply for supplying current to the valve control device;
An ignition switch provided between the power supply device and the valve control device;
A closed state maintaining unit that maintains the first and second master cut valves in a closed state as long as the brake operation member is operated for a set time after the ignition switch is switched from the ON state to the OFF state; The hydraulic brake system according to claim 1, wherein the hydraulic brake system is included.

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