Brake control apparatus

A brake control apparatus comprising:

• a first pressure-applying section connected through a first oil passage to a wheel cylinder, and configured to apply hydraulic pressure to the wheel cylinder;
• a pump provided separately from the first pressure-applying section, and configured to apply hydraulic pressure to the wheel cylinder;
• a communication valve provided on a second oil passage which connects the first oil passage with the pump;
• a backflow passage connecting a suction side of the pump with a portion between the pump and the communication valve in the second oil passage, the backflow passage being connected with a pressure-reducing oil passage;
• a pressure-regulating valve provided on the backflow passage;
• and
• a control unit configured to control the pump, the communication valve and the pressure-regulating valve,
• wherein the control unit is configured
• to attain a first state that causes the first pressure-applying section to apply hydraulic pressure to the wheel cylinder, and a second state that causes the pump to apply hydraulic pressure to the wheel cylinder by driving the pump and at least one of the communication valve and the pressure-regulating valve in an opening direction,
• to actuate the at least one of the communication valve and the pressure-regulating valve with a delay relative to an actuation of the pump, when switching from the first state to the second state, and
• wherein the pump and the pressure-regulating valve are configured to be driven by drive signals outputted from the control unit, and the control unit is configured to output the drive signal for driving the pressure-regulating valve with a delay relative to an output of the drive signal for driving the pump, when switching from the first state to the second state.

A brake control apparatus comprising:

• a first pressure-applying section connected through a first oil passage to a wheel cylinder, and configured to apply hydraulic pressure to the wheel cylinder;
• a pump provided separately from the first pressure-applying section, and configured to apply hydraulic pressure to the wheel cylinder;
• a communication valve provided on a second oil passage which connects the first oil passage with the pump;
• a backflow passage connecting a suction side of the pump with a portion between the pump and the communication valve in the second oil passage, the backflow passage being connected with a pressure-reducing oil passage;
• a pressure-regulating valve provided on the backflow passage;
• and
• a control unit configured to control the pump, the communication valve and the pressure-regulating valve,
• wherein the control unit is configured
• to attain a first state that causes the first pressure-applying section to apply hydraulic pressure to the wheel cylinder, and a second state that causes the pump to apply hydraulic pressure to the wheel cylinder by driving the pump and at least one of the communication valve and the pressure-regulating valve in an opening direction,
• to actuate the at least one of the communication valve and the pressure-regulating valve with a delay relative to an actuation of the pump, when switching from the first state to the second state, and
• wherein, when the second state ends, the control unit actuates the pressure-regulating valve in a closing direction after actuating the communication valve in a closing direction and also after the pump has stopped.

A brake control apparatus comprising:

• a first pressure-applying section connected through a first oil passage to a wheel cylinder, and configured to apply hydraulic pressure to the wheel cylinder;
• a pump provided separately from the first pressure-applying section, and configured to apply hydraulic pressure to the wheel cylinder;
• a communication valve provided on a second oil passage which connects the first oil passage with the pump;
• a backflow passage connecting a suction side of the pump with a portion between the pump and the communication valve in the second oil passage, the backflow passage being connected with a pressure-reducing oil passage;
• and
• a pressure-regulating valve provided on the backflow passage,
• wherein a first state in which the first pressure-applying section applies hydraulic pressure to the wheel cylinder is set against a second state in which the pump applies hydraulic pressure to the wheel cylinder by actuations of the pump and at least one of the communication valve and the pressure-regulating valve,
• the first state is shifted into the second state by actuating the pump in advance of actuating the at least one of the communication valve and the pressure-regulating valve in an opening direction, and
• wherein the pressure-regulating valve is actuated after the pump has become in a predetermined rotational state, when the first state is shifted into the second state.

A brake control apparatus comprising:

• a first pressure-applying section connected through a first oil passage to a wheel cylinder, and configured to apply hydraulic pressure to the wheel cylinder;
• a pump provided separately from the first pressure-applying section, and configured to apply hydraulic pressure to the wheel cylinder;
• a communication valve provided on a second oil passage which connects the first oil passage with the pump;
• a backflow passage connecting a suction side of the pump with a portion between the pump and the communication valve in the second oil passage, the backflow passage being connected with a pressure-reducing oil passage;
• and
• a pressure-regulating valve provided on the backflow passage,
• wherein a first state in which the first pressure-applying section applies hydraulic pressure to the wheel cylinder is set against a second state in which the pump applies hydraulic pressure to the wheel cylinder by actuations of the pump and at least one of the communication valve and the pressure-regulating valve,
• the first state is shifted into the second state by actuating the pump in advance of actuating the at least one of the communication valve and the pressure-regulating valve in an opening direction, and
• the communication valve is actuated in advance of the actuation of the pressure-regulating valve, when the first state is shifted into the second state.

A brake control apparatus comprising:

• a primary-line oil passage including a plurality of wheel cylinders to which hydraulic pressure of a first chamber of a master cylinder is able to be applied by a pedal manipulation of a driver;
• a secondary-line oil passage including a plurality of wheel cylinders to which hydraulic pressure of a second chamber of the master cylinder is able to be applied by the pedal manipulation;
• a shutoff valve provided on each of the primary-line oil passage and the secondary-line oil passage;
• a communication passage connecting the primary-line oil passage with the secondary-line oil passage;
• a pump configured to discharge brake fluid into the communication passage;
• a first communication valve provided on the communication passage and configured to restrict a brake-fluid flow from the communication passage toward the primary-line oil passage;
• a second communication valve provided on the communication passage and configured to restrict a brake-fluid flow from the communication passage toward the secondary-line oil passage;
• a backflow passage connecting a suction side of the pump with a portion between the pump and one of the first and second communication valves in the communication passage, the backflow passage being connected with a pressure-reducing oil passage having a low pressure;
• and
• a pressure-regulating valve provided on the backflow passage,
• wherein a first state in which the master cylinder applies hydraulic pressure to the wheel cylinders by actuating the shutoff valve in an opening direction is set against a second state in which the pump applies hydraulic pressure to the wheel cylinders by selectively driving the shutoff valve, the first and second communication valves, the pressure-regulating valve and the pump,
• wherein a way to shift the first state into the second state has a first mode and a second mode,
• in the first mode, the pressure-regulating valve is opened after actuating the shutoff valve in a closing direction and actuating the pump, and
• in the second mode, the shutoff valve is actuated in the closing direction, after actuating the pressure-regulating valve in the opening direction, actuating at least one of the first and second communication valves in the closing direction, and actuating the pump.