Brake device for vehicle

Patent metadata

Field	Value
Publication number	US-9919690-B2
Application number	US-201214419078-A
Country	US
Kind code	B2
Filing date	Aug 8, 2012
Priority date	Aug 8, 2012
Publication date	Mar 20, 2018
Grant date	Mar 20, 2018

Abstract

A master cylinder generates master cylinder pressures in response to a brake operation by a driver on a brake pedal. A power hydraulic pressure generation device includes a pressure pump and an accumulator, and the accumulator accumulates an accumulator pressure increased by the pressure pump. A hydraulic pressure control valve device includes holding valves, pressure decreasing valves, and master cut valves for carrying out transmission of the master cylinder pressures from the master cylinder or the accumulator pressure from the accumulator. A stroke simulator is connected to a master pressure pipe via a simulator cut valve. The normally-open master cut valves and the normally-closed simulator cut valve for carrying out transmission of the master cylinder pressures mechanically generated by the master cylinder are backed up with backup electric power so that the operations continue even in the event of a change in state of electric power supply.

First claim

The invention claimed is:

1. A brake device for a vehicle, comprising:
a master cylinder for generating a hydraulic pressure in response to an operation by a driver on a brake pedal;
a power hydraulic pressure source for generating a hydraulic pressure through drive of a pressure pump;
a valve mechanism comprising a plurality of electromagnetic valves to be controlled by electric signals, for carrying out transmission of the hydraulic pressure output from the master cylinder or the power hydraulic pressure source, the plurality of electromagnetic valves powered by an electric power storage device;
a wheel cylinder for applying a braking force to a wheel through the transmission of the hydraulic pressure output from the master cylinder or the power hydraulic pressure source via the valve mechanism; and
an electric power supply part for supplying electric power from the electric power storage device installed on the vehicle to the plurality of electromagnetic valves,
the electric power supply part being configured to provide backup electric power, independently of the electric power to be supplied from the electric power storage device, to only a specific electromagnetic valve that is one of the plurality of electromagnetic valves that carry out the transmission of the hydraulic pressure mechanically generated by the master cylinder in response to the operation on the brake pedal.

2. A brake device for a vehicle according to claim 1 , wherein the specific electromagnetic valve is an electromagnetic valve for fluctuating, when the electric power supplied by the electric power supply part from the electric power storage device is shut off, a hydraulic pressure mechanically generated by the master cylinder in response to an operation caused by the shutoff of the supply of the electric power.

3. A brake device for a vehicle according to claim 2 , wherein the fluctuation in the hydraulic pressure mechanically generated by the master cylinder comprises changing of a magnitude of a reaction force input to the brake pedal in response to the operation by the driver, or a magnitude of a stroke of the brake pedal operated by the driver.

4. A brake device for a vehicle according to claim 1 , wherein the specific electromagnetic valve is a normally-open electromagnetic on-off valve, which is supplied with the electric power by the electric power supply part so as to be maintained in a closed state at least when the brake pedal is being operated by the driver.

5. A brake device for a vehicle according to claim 4 , wherein the normally-open electromagnetic on-off valve comprises a master cut valve, which is provided on a hydraulic pressure path through which the hydraulic pressure mechanically generated by the master cylinder is transmitted in response to the operation on the brake pedal, and is supplied with the electric power by the electric power supply part so as to be maintained in the closed state when the hydraulic pressure from the power hydraulic pressure source is being transmitted to the wheel cylinder, to thereby inhibit the hydraulic pressure mechanically generated by the master cylinder from being transmitted to the wheel cylinder.

6. A brake device for a vehicle according to claim 1 , wherein the specific electromagnetic valve is a normally-closed electromagnetic on-off valve, which is supplied with the electric power by the electric power supply part so as to be maintained in an open state at least when the brake pedal is being operated by the driver.

7. A brake device for a vehicle according to claim 6 , wherein the normally-closed electromagnetic on-off valve comprises a simulator cut valve, which is provided on a hydraulic pressure path through which the hydraulic pressure mechanically generated by the master cylinder is transmitted in response to the operation on the brake pedal, and is supplied with the electric power by the electric power supply part so as to be maintained in the open state at least when the hydraulic pressure from the power hydraulic pressure source is being transmitted to the wheel cylinder, to thereby permit communication between the master cylinder and a stroke simulator for adjusting the magnitude of the reaction force applied to the brake pedal operated by the driver and the magnitude of the stroke of the brake pedal.

8. A brake device for a vehicle according to claim 1 , wherein an electrical capacity of the secured backup electric power comprises an electrical capacity for maintaining, in the event of momentary interruption in which the supply of the electric power from the electric power storage device is momentarily interrupted, the operation of the specific electromagnetic valve at least during the momentary interruption.

9. A brake device for a vehicle, comprising:
a master cylinder for generating a hydraulic pressure in response to an operation by a driver on a brake pedal;
a power hydraulic pressure source for generating a hydraulic pressure through drive of a pressure pump;
a valve mechanism comprising a plurality of electromagnetic valves to be controlled by electric signals, for carrying out transmission of the hydraulic pressure output from the master cylinder or the power hydraulic pressure source;
a wheel cylinder for applying a braking force to a wheel through the transmission of the hydraulic pressure output from the master cylinder or the power hydraulic pressure source via the valve mechanism; and
an electric power supply control part for controlling supply of electric power from an electric power storage device installed on the vehicle to the plurality of electromagnetic valves constructing the valve mechanism and to the power hydraulic pressure source,
the electric power supply control part being configured to:
limit, under a state in which the electric power stored in the electric power storage device is low, the plurality of electromagnetic valves constructing the valve mechanism to a specific electromagnetic valve that carries out the transmission of the hydraulic pressure from the power hydraulic pressure source, to thereby supply the electric power from the electric power storage device to the limited specific electromagnetic valve by priority, and
inhibit, under the state in which the electric power stored in the electric power storage device is low, the supply of the electric power from the electric power storage device to an electric motor constricting the pressure pump when the brake pedal is being operated by the driver.

10. A brake device for a vehicle according to claim 9 , wherein:
the power hydraulic pressure source comprises an accumulator for accumulating the hydraulic pressure generated through the drive of the pressure pump; and
the specific electromagnetic valve comprises at least an electromagnetic valve provided on a hydraulic pressure path for communicating the accumulator of the power hydraulic pressure source and the master cylinder to each other.

11. A brake device for a vehicle according to claim 10 , wherein the hydraulic pressure path for communicating the accumulator of the power hydraulic pressure source and the master cylinder to each other further communicates to the wheel cylinder for applying the braking force to a wheel on a front wheel side of the vehicle.

12. A brake device for a vehicle according to claim 11 , wherein the specific electromagnetic valve comprises a normally-closed electromagnetic on-off valve for permitting or inhibiting the communication between the power hydraulic pressure source and the wheel cylinder for applying the braking force to the wheel on the front wheel side.

13. A brake device for a vehicle according to claim 10 , wherein, under the state

Assignees

• Miyazaki Tetsuya
• Toyota Motor Co Ltd

Inventors

• Miyazaki Tetsuya

Classifications

• B60T13/686 Primary

  in hydraulic systems or parts thereof · CPC title

• B60T8/4081

  Systems with stroke simulating devices for driver input (B60T8/4077 takes precedence) · CPC title

• B60T13/662

  characterised by specified functions of the control system components · CPC title

• B60T8/321

  deceleration (B60T8/34, B60T8/52, B60T8/54, B60T8/56, B60T8/58, B60T8/72, B60T8/86, B60T8/88 take precedence) · CPC title

• B60T8/885

  using electrical circuitry · CPC title