Vehicle brake system

• US 7,290,840 B2
• Filed: 03/27/2006
• Issued: 11/06/2007
• Est. Priority Date: 04/24/2003
• Status: Expired due to Fees

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Eguchi, Takaaki, Tsunehara, Hiroshi, Hara, Masanori, Murakami, Hideto
• Primary Examiner(s): TORRES WILLIAMS, MELANIE
• Application Number:
  US11/389,156
• Publication Number:
  US 20060163942A1
• Time in Patent Office: 589 Days
• Field of Search: 303/3, 303/9.61, 303/9.62, 303/10, 303/11, 303/13, 303/15, 303/152, 303/113.5
• US Class Current: 303/11
• CPC Class Codes: B60L 7/26 Controlling the braking effect
• CPC Class Codes: B60T 1/10 by utilising wheel movement for accumulating energy, e.g. driving air compressors
• CPC Class Codes: B60T 13/585 comprising friction brakes and retarders
• CPC Class Codes: B60T 13/66 Electrical control in fluid-pressure brake systems
• CPC Class Codes: B60T 2270/602 ABS features related thereto
• CPC Class Codes: B60T 2270/603 ASR features related thereto
• CPC Class Codes: B60T 2270/608 Electronic brake distribution (EBV/EBD) features related thereto
• CPC Class Codes: B60T 2270/613 ESP features related thereto
• CPC Class Codes: B60T 8/267 for hybrid systems with different kind of brakes on different axles
• CPC Class Codes: B60T 8/348 4 Channel systems B60T8/345 takes precedence
• CPC Class Codes: B60T 8/4072 Systems in which a driver input signal is used as a control signal for the additional fluid circuit which is normally used for braking
• CPC Class Codes: B60T 8/4081 Systems with stroke simulating devices for driver input B60T8/4077 takes precedence
• CPC Class Codes: B60T 8/442 the booster being a fluid return pump, e.g. in combination with a brake pedal force booster

Abstract

A brake system for a vehicle is comprised of a first brake system that mechanically applies a braking force to wheels according to a master cylinder hydraulic pressure outputted from a master cylinder which receives a brake manipulation force of a driver, and a second brake system that apply a braking force to other wheels according to at least a braking state of the first brake system.

Claims

1. The brake system wherein the first brake system comprises a first pressure increasing and decreasing valve through which a first brake hydraulic pressure of the first brake system is controlled, and the second brake system comprises a second pressure increasing and decreasing valve through which a second brake hydraulic pressure of the second brake system is controlled according to at least a detection result of a braking state of the first brake system,

wherein the brake system further comprises a pressure source selector valve which is disposed between a circuit connecting the master cylinder of the first brake system and the first pressure increasing valve and a circuit connecting another pressure source of the second brake system and the second pressure increasing and decreasing valve, the pressure source selector valve being normally closed, the pressure source selector valve being opened so as to employ the another pressure source of the second brake system as a pressure source of the first brake system.

2. The brake system as claimed in claim 1, wherein a master cut valve is disposed at a portion near the master cylinder in the circuit connecting the master cylinder of the first brake system and the first pressure increasing and decreasing valve.

3. The brake system as claimed in claim 1, wherein a fail safe valve, which is closed when the pressure source of the second brake system is put in a disabled state, is disposed between the pressure source of the second brake system and the second pressure increasing and decreasing valve, and the pressure source selector valve is closed when the pressure source of the second brake system is put in the disabled state.

4. The brake system as claimed in claim 1, wherein the second brake system is constructed by two independent circuits which independently comprise pressure sources, respectively.

5. The brake system as claimed in claim 1, further comprising a drain cut valve which is disposed in a drain circuit for a pressure decreasing valve of the pressure increasing and decreasing valves for the first brake system and the second brake system.

6. The brake system as claimed in claim 1, further comprising a discharge block valve which is disposed in a drain circuit for a pressure decreasing valve of the pressure increasing and decreasing valves for the first brake system and the second brake system.

7. The brake system as claimed in claim 6, further comprising an accumulator which is connected to the drain circuit upstream of the discharge block valve, the accumulator storing the brake fluid discharged from the master cylinder when the discharge block valve is closed.

8. The brake system as claimed in claim 6, further comprising a reservoir which is connected to the drain circuit downstream of the discharge block valve, another pressure source which is connected to the drain circuit upstream of the discharge block valve so that the brake fluid is supplied to the another pressure source from the drain circuit, and a check valve which is disposed in the drain circuit so as to be disposed in parallel with the discharge block valve.