Vehicle brake system

Patent metadata

Field	Value
Publication number	US-9358891-B2
Application number	US-201214399727-A
Country	US
Kind code	B2
Filing date	May 21, 2012
Priority date	May 21, 2012
Publication date	Jun 7, 2016
Grant date	Jun 7, 2016

Abstract

A vehicle brake system for braking a vehicle including a braking-mode switching mechanism configured to selectively effectuate, depending upon situations of the vehicle brake system, one of (A) a regulated-pressure-dependent braking mode in which is generated a regulated-pressure-dependent braking force having a magnitude that depends on a regulated pressure of a working fluid and (B) a braking mode depending on an operation force and the regulated pressure in which are generated both of an operation-force-dependent braking force having a magnitude that depends on the operation force by a driver and the regulated-pressure-dependent braking force.

First claim

The invention claimed is:

1. A vehicle brake system for braking a vehicle, comprising a hydraulic brake system configured to generate a braking force in dependence on a pressure of a working fluid, a regenerative brake system configured to generate a braking force while regenerating running energy of the vehicle into electric energy, and a brake controller configured to control the vehicle brake system,
wherein the hydraulic brake system includes:
a brake device provided for a wheel of the vehicle and configured to generate a braking force having a magnitude that depends on the pressure of the working fluid supplied thereto;
a master cylinder device configured to pressurize the working fluid and to supply the pressurized working fluid to the brake device;
a brake operation member which is connected to the master cylinder device and on which a brake operation by a driver is performed;
a high-pressure-source device configured to highly pressurize a working fluid;
a pressure regulator device configured to regulate the working fluid highly pressurized by the high-pressure-source device and to supply the working fluid whose pressure is regulated; and
a braking-mode switching mechanism configured to selectively effectuate, as a braking mode of the hydraulic brake system, one of (A) a regulated-pressure-dependent braking mode in which the hydraulic brake system generates a regulated-pressure-dependent braking force having a magnitude that depends on a regulated pressure that is a pressure of the working fluid supplied from the pressure regulator device, without substantially depending on an operation force applied by the driver to the brake operation member and (B) a braking mode depending on the operation force and the regulated pressure in which the hydraulic brake system generates both of an operation-force-dependent braking force having a magnitude that depends on the operation force and the regulated-pressure-dependent braking force, and

wherein the vehicle brake system is configured (a) to brake the vehicle by the operation-force-dependent braking force and the regulated-pressure-dependent braking force, such that the braking-mode switching mechanism effectuates the braking mode depending on the operation force and the regulated pressure and such that the regenerative brake system does not generate a regenerative braking force that is the braking force generated by the regenerative brake system, at least after the brake device becomes capable of generating the braking force in a period from a time point of initiation of the brake operation to a time point when an operation amount of the brake operation member becomes constant and (b) to brake the vehicle by the regulated-pressure-dependent braking force and the regenerative braking force such that the braking-mode switching mechanism effectuates the regulated-pressure-dependent braking mode and such that the regenerative brake system generates the regenerative braking force, when the operation amount becomes constant.

2. The vehicle brake system according to claim 1 ,
wherein the pressure regulator device includes a pressure regulator configured to regulate a working fluid having a high pressure and supplied from a high-pressure-source device, to a pressure in accordance with a pilot pressure introduced thereinto and configured to supply the working fluid whose pressure is regulated, and:
wherein the pressure regulator includes:
a housing;
a high-pressure passage which is formed in the housing and through which the working fluid supplied from the high-pressure-source device is introduced into the housing;
a low-pressure passage which is formed in the housing and through which the working fluid is discharged from the housing to a low-pressure source;
a regulated-pressure chamber from which the working fluid whose pressure is regulated is supplied;
a pilot chamber that receives the working fluid whose pressure is equal to the pilot pressure;
a movable member provided in and supported by the housing so as to be movable in an axial direction of the housing;
a first plunger disposed on a first-end side of the movable member so as to be movable in the axial direction of the housing, the first-end side being defined as one of opposite sides of the housing in the axial direction;
a second plunger disposed on the first-end side or a second-end side of the movable member so as to be movable in the axial direction of the housing, the second-end side being defined as the other of the opposite sides of the housing in the axial direction;
a first biasing mechanism configured to bias the movable member toward the first-end side;
a second biasing mechanism configured to bias the movable member toward the second-end side via the first plunger by a pressure of the pilot chamber;
a third biasing mechanism configured such that, when a pressure of the regulated-pressure chamber exceeds a set pressure, the third biasing mechanism biases one of the movable member and the first plunger toward the first-end side via the second plunger by the pressure of the regulated-pressure chamber, with the second plunger held in contact with the one of the movable member and the first plunger; and
a valve mechanism configured to selectively effectuate one of: (A) a state in which communication between the high-pressure passage and the regulated-pressure chamber is shut off while communication between the low-pressure passage and the regulated-pressure chamber is established; and (B) a state in which the communication between the high-pressure passage and the regulated-pressure chamber is established while the communication between the low-pressure passage and the regulated-pressure chamber is shut off, by an action of the movable member owing to biasing forces of the first biasing mechanism, the second biasing mechanism, and the third biasing mechanism, respectively.

3. The vehicle brake system according to claim 2 ,
wherein the second plunger is disposed on the second-end side of the movable member so as to be movable in the axial direction of the housing, and
wherein the valve mechanism is configured to effectuate: (a) the state in which the communication between the high-pressure passage and the regulated-pressure chamber is shut off while the communication between the low-pressure passage and the regulated-pressure chamber is established, when the movable member is located at a moving end position; and (b) the state in which the communication between the high-pressure passage and the regulated-pressure chamber is established while the communication between the low-pressure passage and the regulated-pressure chamber is shut off, when the movable member moves from the moving end position toward the second-end side.

4. The vehicle brake system according to claim 3 , wherein the third biasing mechanism is configured such that a ratio of an increase in the biasing force for biasing the movable member with respect to an increase in the pressure of the regulated-pressure chamber increases when the pressure of the regulated-pressure chamber exceeds a second set pressure that is higher than the set pressure.

5. The vehicle brake system according to claim 2 ,
wherein the regulated-pressure chamber is formed around an outer circumference of the movable member,
wherein the first biasing mechanism is configured to also bias the first plunger toward the first-end side,
wherein the valve mechanism has:
a regulated-pressure passage formed in the movable member, the regulated-pressure passage communicating, at one end thereof, with the regulated-pressure chamber and having, at the other end thereof, an opening that is open to an end face of the movable member on the first-end side; and
a structure in which an end portion of the first plunger on the second-end side is abuttable on the movable m

Assignees

• Isono Hiroshi
• Mizutani Yasuji
• Toyota Motor Co Ltd

Inventors

• Isono Hiroshi
• Mizutani Yasuji

Classifications

• B60T13/686

  in hydraulic systems or parts thereof · CPC title

• B60T2270/604

  Merging friction therewith; Adjusting their repartition · CPC title

• B60T11/16

  Master control, e.g. master cylinders (master cylinders associated with vacuum boosters B60T13/565) · CPC title

• B60T8/17

  Using electrical or electronic regulation means to control braking {(detecting or indicating faulty operation B60T8/885)} · CPC title

• B60T8/34

  having a fluid pressure regulator responsive to a speed condition · CPC title