Hydraulic brake system

Patent metadata

Field	Value
Publication number	US-9533663-B2
Application number	US-201013508818-A
Country	US
Kind code	B2
Filing date	Mar 3, 2010
Priority date	Mar 3, 2010
Publication date	Jan 3, 2017
Grant date	Jan 3, 2017

Abstract

A hydraulic brake system including: (a) a first hydraulic-pressure generating device including a manual hydraulic pressure source; (b) a second hydraulic-pressure generating device including a power hydraulic pressure source; (c) a manual-operation-associated brake line including a communicating device that is to be brought into communication with the manual hydraulic pressure source and brake cylinder or cylinders of the plurality of hydraulic brakes; (d) an output hydraulic-pressure control device and a flow restraining device disposed in parallel with each other between the manual-operation-associated brake line and the second hydraulic-pressure generating device; and (e) a power hydraulic pressure source control device for activating the power hydraulic pressure source such that the hydraulic pressure is supplied to the manual-operation-associated brake line via the flow restraining device, when the output hydraulic-pressure control device cannot control the hydraulic pressure outputted by the second hydraulic-pressure generating device.

First claim

The invention claimed is:

1. A hydraulic brake system, comprising:
a first hydraulic-pressure generating device including a manual hydraulic pressure source which is configured to generate hydraulic pressure by operation of a brake operating member by an operator;
a second hydraulic-pressure generating device including a power hydraulic pressure source which is activatable by supply of electric energy thereto and which is configured to generate hydraulic pressure by activation thereof;
a plurality of hydraulic brakes provided for a plurality of wheels of a vehicle, and activatable by hydraulic pressures in respective brake cylinders thereof so as to restrain rotations of the respective wheels;
a manual-operation-associated brake line including (i) a communicating device which is communicable with said manual hydraulic pressure source and which is communicable at least one of said brake cylinders of said plurality of hydraulic brakes, (ii) said first hydraulic-pressure generating device, and (iii) said at least one of said brake cylinders;
an output hydraulic-pressure control device and a flow restraining device disposed in parallel with each other between said manual-operation-associated brake line and said second hydraulic-pressure generating device, said output hydraulic-pressure control device being configured to control the hydraulic pressure outputted from said second hydraulic-pressure generating device, said flow restraining device being configured to restrain flow of a working fluid away from said second hydraulic-pressure generating device toward said manual-operation-associated brake line;
a power hydraulic pressure source control device configured to activate said power hydraulic pressure source such that the hydraulic pressure is supplied from said power hydraulic pressure source to said manual-operation-associated brake line via said flow restraining device, when said hydraulic brake system is in a failure state disabling said output hydraulic-pressure control device from controlling the hydraulic pressure outputted by said second hydraulic-pressure generating device;
a front-wheel common passage to which said brake cylinders of said hydraulic brakes provided for respective front right and left wheels as ones of the plurality of wheels are connected via respective two front-wheel individual passages,
wherein said manual hydraulic pressure source is constituted by each of two pressurizing chambers of a tandem master cylinder which includes two pressurizing pistons and which is configured to generate the hydraulic pressures in said two pressurizing chambers by operation of said brake operating member, said two pressurizing chambers being connected to said respective two front-wheel individual passages via respective two front-wheel individual connection passages,
and wherein said communicating device includes (i) said front-wheel common passage, (ii) one of said two front-wheel individual passages, and (iii) one of said two front-wheel individual connection passages which is connected to said one of said two front-wheel individual passages;
a front-wheel individual control valve provided in said one of said two front-wheel individual passages, and constituted by a normally-open electromagnetic valve which is switchable between an open state and a closed state by control of supply of an electric current to a solenoid thereof and which is to be placed in the open state when the electric current is not being supplied to the solenoid thereof; and
another from-wheel individual control valve provided in another one of said two front-wheel individual passages, and constituted by a normally-closed electromagnetic valve which is switchable between an open state and a closed state by control of supply of an electric current to a solenoid thereof and which is to be placed in the closed state when the electric current is not being supplied to the solenoid thereof,
wherein said one of said two front-wheel individual connection passages is connected to a portion of said one of said two front-wheel individual passages which is located on a downstream side of said front-wheel individual control valve constituted by said normally-open electromagnetic valve, while another one of said two front-wheel individual connection passages is connected to a portion of said another one of said two front-wheel individual passages which is located on a downstream side of said another front-wheel individual control valve constituted by said normally-closed electromagnetic valve.

2. The hydraulic brake system according to claim 1 , comprising manual-passage cut-off valves each of which is provided in a corresponding one of said two front-wheel individual connection passages and each of which is a normally-open electromagnetic valve that is to be placed in an open state when the electric current is not being supplied to a solenoid thereof.

3. The hydraulic brake system according to claim 1 , further comprising:
a controlling portion configured to control said electromagnetic valve based on an operational state of said brake operating member such that the hydraulic pressures in said brake cylinders are controlled to required hydraulic pressures that are determined based on an operational state of said brake operating member,
wherein said power hydraulic pressure source control device is configured to activate said power hydraulic pressure source such that the hydraulic pressure is supplied from said power hydraulic pressure source to said manual-operation-associated brake line via said flow restraining device, when the hydraulic pressure outputted from said second hydraulic-pressure generating device is uncontrollable due to failure of at least one of said electromagnetic valve and said controlling portion.

4. The hydraulic brake system according to claim 3 ,
wherein said power hydraulic pressure source includes an electric motor as a drive source and a pump that is to be activated by said electric motor,
and wherein said power hydraulic pressure source control device is configured to activate said electric motor when the hydraulic pressure outputted from said second hydraulic-pressure generating device is uncontrollable due to the failure of said at least one of said electromagnetic valve and said controlling portion.

5. The hydraulic brake system according to claim 3 ,
wherein said power hydraulic pressure source control device is configured to activate said power hydraulic pressure source such that the hydraulic pressure is supplied from said power hydraulic pressure source to said manual-operation-associated brake line via said flow restraining device, when said hydraulic brake system is in a failure state disabling said output hydraulic-pressure control device from controlling the hydraulic pressure outputted by said second hydraulic-pressure generating device while said brake operating member is being operated and said electromagnetic valve is in a closed state.

6. The hydraulic brake system according to claim 3 ,
wherein said communicating device includes a manual passage connecting one of said two pressurizing chambers and one of said brake cylinders of said hydraulic brakes provided for respective front right and left wheels,
wherein said manual passage is constituted by said one of said two front-wheel individual connection passages and a portion of said one of said two front-wheel individual passages which portion is closer to said one of said brake cylinders of said hydraulic brakes provided for respective front right and left wheels than said portion of said one of said two front-wheel individual passages which is connected to said one of said two front-wheel individual connection passages,
and wherein said flow restraining device is disposed between said second hydraulic-pressure generating device a

Assignees

• Miyazaki Tetsuya
• Yamamoto Takayuki
• Tanaka Yoshito
• Toyota Motor Co Ltd

Inventors

• Miyazaki Tetsuya
• Yamamoto Takayuki
• Tanaka Yoshito

Classifications

• B60T2270/402

  Back-up · CPC title

• B60T8/94

  on a fluid pressure regulator · CPC title

• B60T8/4081 Primary

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

• B60T8/885

  using electrical circuitry · CPC title