Hydraulic brake system and method as well as control device for its operation

Patent metadata

Field	Value
Publication number	US-9409558-B2
Application number	US-201113580517-A
Country	US
Kind code	B2
Filing date	Jan 25, 2011
Priority date	Feb 26, 2010
Publication date	Aug 9, 2016
Grant date	Aug 9, 2016

Abstract

A hydraulic brake system has: a force-pressure conversion element, which is in hydraulic connection with at least one wheel brake cylinder of at least one wheel; a volume-adaptation element in hydraulic connection with the at least one wheel brake and the force-pressure conversion element; and as an actuating unit for actuating the force-pressure conversion element, which actuating unit has an input element. The pressure in the at least one wheel brake cylinder is adjusted by operating the volume-adaptation unit and/or the actuating unit. For this purpose an actuating state of the input element is maintained by operating the actuating unit when the volume-adaptation unit is being operated.

First claim

What is claimed is:

1. A hydraulic brake system for a vehicle having multiple wheel brake cylinders corresponding to multiple wheels, comprising:
a brake master cylinder in hydraulic connection with at least one wheel brake cylinder of the multiple wheel brake cylinders of at least one wheel of the multiple wheels;
a plunger in hydraulic connection with the at least one wheel brake cylinder and the brake master cylinder; and
a brake force booster for actuating the brake master cylinder, wherein the brake force booster has an input element, wherein, during a pressure adjustment in the at least one wheel brake cylinder by an operation of the plunger, an actuating position of the input element is maintained by an operation of the brake force booster and a non-varying force applied by a driver and capable of causing a displacement of the input element, wherein the hydraulic connection among the at least one wheel brake cylinder, the plunger and the brake master cylinder is continuously maintained during the pressure adjustment at the at least one wheel brake cylinder;
wherein the pressure adjustment in the at least one wheel brake cylinder takes place by operating the plunger and the brake force booster when at least one hydraulic connection has been established among the at least one wheel brake cylinder, the plunger and the brake master cylinder, and wherein during the pressure adjustment in the at least one wheel brake cylinder, the hydraulic connection between the remaining wheel brake cylinders of the multiple wheel brake cylinders located between the at least one wheel brake cylinder, the plunger and the brake master cylinder is interrupted.

2. The hydraulic brake system as recited in claim 1 , wherein the retention of the actuating state of the input element corresponding to a retention of the force to be applied in order to keep the input element at a particular position, and wherein the brake force booster is controlled in such a way that (i) the non-varying force to be applied by the driver in order to keep the input element at a particular position is independent of the pressure prevailing in the brake system, and (ii) an actuating position of the brake force booster is maintained.

3. The hydraulic brake system as recited in claim 1 , wherein the establishment of the at least one hydraulic connection among the at least one wheel brake cylinder, the plunger and the brake master cylinder takes place by at least one interruption element of a first type and at least one interruption element of a second type.

4. The hydraulic brake system as recited in claim 3 , wherein the at least one wheel brake cylinder is hydraulically connected to the brake master cylinder via precisely one interruption element of the second type.

5. The hydraulic brake system as recited in claim 3 , wherein the interruption element of the first type is one of (i) a switching valve which is closed in the deenergized state, or (ii) a control valve which is closed in the deenergized state.

6. The hydraulic brake system as recited in claim 3 , wherein the interruption element of the second type is one of (i) a switching valve which is open in the deenergized state, or (ii) a control valve which is open in the deenergized state.

7. The hydraulic brake system as recited in claim 1 , wherein the pressure adjustment in the at least one wheel brake cylinder takes place by operating the plunger via at least one of (i) a direct hydraulic connection of the plunger to the at least one wheel brake cylinder and (ii) an indirect hydraulic connection via the brake master cylinder.

8. The hydraulic brake system as recited in claim 1 , wherein the non-varying force is applied by the driver to a pedal, wherein the pedal and the input element are distinct.

9. A method for operating a hydraulic brake system for a vehicle having multiple wheel brake cylinders corresponding to multiple wheels, comprising:
providing a brake master cylinder in hydraulic connection with at least one wheel brake cylinder of the multiple wheel brake cylinders of at least one wheel of the multiple wheels;
providing a plunger in hydraulic connection with the at least one wheel brake and the brake master cylinder; and
actuating the brake master cylinder using a brake force booster having an input element, wherein in a first operating mode, during a pressure adjustment in the at least one wheel brake cylinder by an operation of the plunger, an actuating position of the input element is maintained by an operation of the brake force booster and a non-varying force applied by a driver and capable of causing a displacement of the input element, wherein the hydraulic connection among the at least one wheel brake cylinder, the plunger and the brake master cylinder is continuously maintained during the pressure adjustment at the at least one wheel brake cylinder;
wherein the pressure adjustment in the at least one wheel brake cylinder takes place by operating the plunger and the brake force booster when at least one hydraulic connection has been established among the at least one wheel brake cylinder, the plunger and the brake master cylinder, and wherein during the pressure adjustment in the at least one wheel brake cylinder, the hydraulic connection between the remaining wheel brake cylinders of the multiple wheel brake cylinders located between the at least one wheel brake cylinder, the plunger and the brake master cylinder is interrupted.

10. The method as recited in claim 9 , wherein the pressure in the at least one wheel brake cylinder is adjusted in temporal sequence with at least one of the other wheel brake cylinders.

11. The method as recited in claim 9 , wherein in a second operating mode, the pressure is adjusted solely by actuating the brake force booster.

12. The method as recited in claim 9 , wherein the pressure adjustment at the at least one wheel brake cylinder takes place during an active pressure buildup and is independent of the driver.

13. The method as recited in claim 12 , wherein in an active pressure buildup, the brake force booster is operated in such a way that an exchange of brake medium between the brake master cylinder and a brake medium reservoir assigned to the brake master cylinder is prevented.

14. The method as recited in claim 9 , wherein the pressure adjustment at the at least one wheel brake cylinder takes place during a pressure modulation in order to prevent locking of the at least one wheel assigned to the at least one wheel brake cylinder.

15. The method as recited in claim 9 , wherein the hydraulic brake system is part of an overall brake system having an additional regenerative brake system in addition to the hydraulic brake system, and wherein the pressure adjustment at the at least one wheel brake cylinder takes place within the framework of an adaptation of a hydraulic braking effect to a braking effect of the regenerative brake torque.

16. The method as recited in claim 15 , wherein an overall braking effect, which includes the hydraulic braking effect and the regenerative braking effect, is kept constant by adapting the hydraulic braking effect.

17. The method as recited in claim 9 , wherein the non-varying force is applied by the driver to a pedal, wherein the pedal and the input element are distinct.

18. A control device for controlling operation of a hydraulic brake system for a vehicle having multiple wheel brake cylinders corresponding to multiple wheels, wherein the control device is configured to:
provide a brake master cylinder in hydraulic connection with at least one wheel brake cylinder o

Assignees

• Pfeiffer Wolfgang
• Nagel Willi
• Harter Werner
• Bolz Martin-Peter
• Bauer Urs
• Bosch Gmbh Robert

Inventors

• Pfeiffer Wolfgang
• Nagel Willi
• Harter Werner
• Bolz Martin-Peter
• Bauer Urs

Classifications

• B60T8/4018 Primary

  Pump units characterised by their drive mechanisms (B60T8/4095 takes precedence) · CPC title

• B60T13/12 Primary

  the fluid being liquid · CPC title

• B60T13/745

  acting on a hydraulic system, e.g. a master cylinder · CPC title

• B60T8/4077

  Systems in which the booster is used as an auxiliary pressure source · CPC title

• B60T13/74

  with electrical assistance or drive · CPC title