Brake system

Patent metadata

Field	Value
Publication number	US-2018354484-A1
Application number	US-201815990869-A
Country	US
Kind code	A1
Filing date	May 29, 2018
Priority date	Jun 7, 2017
Publication date	Dec 13, 2018
Grant date	—

Abstract

A brake system includes: brake cylinders; electromagnetic valve devices respectively corresponding to the brake cylinders and capable of individually controlling hydraulic pressures in the respective brake cylinders; pumps respectively connected to the brake cylinders; one pump motor driven in common with the pumps; and a brake-hydraulic-pressure controller that controls the electromagnetic valve devices and the one pump motor to control the hydraulic pressures in the respective brake cylinders. The brake-hydraulic-pressure controller includes: a first pressure-increase controller that controls the one pump motor to bring the hydraulic pressures in the respective brake cylinders closer to respective target hydraulic pressures; and a second pressure-increase controller that controls the one pump motor based on a greatest one of the target hydraulic pressures for the respective brake cylinders and control the electromagnetic valve devices to bring the hydraulic pressures in the respective brake cylinders closer to the respective target hydraulic pressures.

First claim

What is claimed is:

1 . A brake system, comprising:
a plurality of brake cylinders; a plurality of electromagnetic valve devices provided respectively corresponding to the brake cylinders and capable of individually controlling hydraulic pressures in the respective brake cylinders; a plurality of pumps respectively connected to the brake cylinders; one pump motor driven in common with the pumps; and a brake-hydraulic-pressure controller configured to control the electromagnetic valve devices and the one pump motor to control a brake hydraulic pressure that is each of the hydraulic pressures in the respective brake cylinders, wherein the brake-hydraulic-pressure controller comprises:
a first pressure-increase controller configured to control the one pump motor to bring the hydraulic pressures in the respective brake cylinders closer to respective target hydraulic pressures; and
a second pressure-increase controller configured to control the one pump motor based on a greatest one of the target hydraulic pressures for the respective brake cylinders and control the electromagnetic valve devices to bring the hydraulic pressures in the respective brake cylinders closer to the respective target hydraulic pressures.

2 . The brake system according to claim 1 , wherein the brake-hydraulic-pressure controller comprises a controller selector configured to select one of the first pressure-increase controller and the second pressure-increase controller based on a state of the brake system.

3 . The brake system according to claim 2 , wherein the controller selector is configured to:
select the first pressure-increase controller when the target hydraulic pressures for the respective brake cylinders are equal to each other; and select the second pressure-increase controller when the target hydraulic pressures for the respective brake cylinders are different from each other.

4 . The brake system according to claim 2 , wherein the controller selector is configured to:
select the first pressure-increase controller when the target hydraulic pressures for the respective brake cylinders are equal to each other, and each of the target hydraulic pressures for the respective brake cylinders is greater than a set hydraulic pressure; and select the second pressure-increase controller when at least one of the target hydraulic pressures for the respective brake cylinders is less than or equal to the set hydraulic pressure.

5 . The brake system according to claim 4 , wherein the controller selector comprises a set-hydraulic-pressure determiner configured to determine the set hydraulic pressure based on at least one of a temperature of working liquid in the brake system and a voltage of a power source configured to supply electric power to at least the one pump motor.

6 . The brake system according to claim 5 , wherein the set-hydraulic-pressure determiner is configured to determine the set hydraulic pressure to a value that is greater when the temperature of the working liquid is low than when the temperature of the working liquid is high.

7 . The brake system according to claim 5 ,
wherein the power source comprises a battery, and wherein the set-hydraulic-pressure determiner is configured to determine the set hydraulic pressure to a value that is less when the voltage of the power source is low than when the voltage of the power source is high.

8 . The brake system according to claim 2 , wherein the controller selector is configured to select the second pressure-increase controller in a case of a malfunction in at least one sensor that is used in control for the one pump motor.

9 . The brake system according to claim 8 , wherein the second pressure-increase controller comprises a target-hydraulic-pressure determiner configured to determine each of the target hydraulic pressures for the respective brake cylinders to a value that is greater in a case of a malfunction in the at least one sensor than in a case of no malfunction in the at least one sensor.

10 . The brake system according to claim 1 , wherein the second pressure-increase controller is configured to control the one pump motor to keep a rotation speed of each of the pumps constant.

11 . The brake system according to claim 1 ,
wherein each of the electromagnetic valve devices comprises at least one electromagnetic valve each provided between a reservoir and a corresponding one of the brake cylinders, and wherein the second pressure-increase controller comprises an electromagnetic-valve controller configured to bring the hydraulic pressures in the respective brake cylinders closer to the respective target hydraulic pressures by controlling a current to be supplied to at least one solenoid of the at least one electromagnetic valve of each of the electromagnetic valve devices.

12 . The brake system according to claim 1 ,
wherein each of the electromagnetic valve devices comprises at least one electromagnetic valve each provided between a reservoir and a corresponding one of the brake cylinders, and wherein the first pressure-increase controller is configured to control the one pump motor in a state in which at least one of the at least one electromagnetic valve is closed in each of the electromagnetic valve devices.

Assignees

• Toyota Motor Co Ltd

Inventors

• Yamamoto Naoki

Classifications

• B60T13/16

  using pumps directly, i.e. without interposition of accumulators or reservoirs · CPC title

• B60T8/4836

  wherein a booster output pressure is used for normal or anti lock braking (B60T8/4845, B60T8/4863, B60T8/489 take precedence) · CPC title

• B60T13/12

  the fluid being liquid · CPC title

• B60T13/662 Primary

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

• B60T13/74 Primary

  with electrical assistance or drive · CPC title