Vehicle brake system for a motor vehicle and method for actuating the vehicle brake system during release of the parking brake function

Patent metadata

Field	Value
Publication number	US-9340192-B2
Application number	US-201113813304-A
Country	US
Kind code	B2
Filing date	Jul 7, 2011
Priority date	Aug 3, 2010
Publication date	May 17, 2016
Grant date	May 17, 2016

Abstract

A vehicle brake system having a hydraulically actuable disc brake device which has an electromechanical actuating device for activating a parking brake function, wherein the vehicle brake system has a hydraulic circuit with a hydraulic pressure source and actuable hydraulic functional elements, in order to hydraulically actuate the disc brake device in accordance with a service brake action of a driver or an automatic activation of a driving assistance system, wherein, furthermore, the vehicle brake system has a control device, in order to actuate the electromechanical actuating device in accordance with a parking brake action of the driver or an automatic activation of the parking brake function. In order to avoid abrupt release of the parking brake function, it is provided here that the control device is configured for actuating at least one of the hydraulic functional elements in such a way that, in order to release the parking brake function, a hydraulic fluid volume is isolated in the disc brake device by actuation of the electromechanical actuating device and the hydraulic fluid volume can be used to generate a predefined hydraulic pressure hydraulically during the release of the parking brake function by the electromechanical actuating device.

First claim

The invention claimed is:

1. A vehicle brake system with a hydraulically controllable disc brake device, which has an electromechanical actuating device for activating a parking brake function, the vehicle brake system having a hydraulic circuit with a hydraulic pressure source, as well as controllable hydraulic function elements, in order to hydraulically control the disc brake device in accordance with a service brake action of a driver or an automatic activation, the vehicle brake system further having a control device, in order to control the electromechanical actuating device in accordance with a parking brake action of the driver or an automatic activation of the parking brake function,
wherein the control device is adapted to control at least one of the hydraulic function elements in such a way that, in order to release the parking brake function by controlling the electromechanical actuating device, a hydraulic fluid volume present in the disc brake device can be hydraulically isolated to generate a predetermined hydraulic pressure during the release of the parking brake function by means of the electromechanical actuating device and wherein the freeing of the hydraulic fluid is carried out in accordance with a gradient, wherein the gradient is adjusted in accordance with certain parameters based on the parameters representing a starting process.

2. The vehicle brake system according to claim 1 ,
wherein the hydraulic circuit has a plurality of controllable valves, in order to selectively charge individual disc brake devices of the vehicle brake system with hydraulic pressure or to hydraulically isolate the disc brake devices.

3. The vehicle brake system according to claim 2 ,
wherein the valves are controllable via the control device in such a way that only those disc brake devices of the vehicle brake system which are designed with the electromechanical actuating device can be hydraulically isolated.

4. The vehicle brake system according to claim 2 ,
wherein the hydraulic fluid volume can be isolated by means of at least one valve assigned to the slip control function.

5. The vehicle brake system according to claim 1 ,
wherein the control device is formed with a slip control function.

6. The vehicle brake system according to claim 1 ,
wherein the hydraulic circuit has a plurality of controllable valves, in order to selectively charge individual disc brake devices of the vehicle brake system with hydraulic pressure or hydraulically isolate the disc brake devices, and wherein the control device is formed with a slip control function.

7. A method for controlling a vehicle brake system with a hydraulically controllable disc brake device, which has an electromechanical actuating device for activating a parking brake function, the vehicle brake system having a hydraulic circuit with a hydraulic pressure source, as well as controllable hydraulic function elements, in order to hydraulically control the disc brake device in accordance with a service brake action of a driver or an automatic activation, the vehicle brake system further having a control device, in order to control the electromechanical actuating device in accordance with a parking brake action of the driver or an automatic activation of the parking brake function,
wherein the control device is adapted to control at least one of the hydraulic function elements in such a way that, in order to release the parking brake function by controlling the electromechanical actuating device, a hydraulic fluid volume present in the disc brake device can be hydraulically isolated to generate a predetermined hydraulic pressure during the release of the parking brake function by means of the electromechanical actuating device to release a parking brake function comprising the following steps:
detecting a command to release an activated parking brake function,
isolating a hydraulic fluid volume present in the disc brake device by controlling the hydraulic circuit in order to exert a hydraulic pressure in the disc brake device on the release of the parking brake function,
activating the electromechanical actuating device to release the parking brake function,
freeing the hydraulic fluid volume, wherein the freeing of the hydraulic fluid is carried out in accordance with a gradient, and
adjusting the gradient in accordance with certain parameters based on the parameters representing a starting process.

8. The method according to claim 7 ,
wherein the parameters comprise current values or a time profile of an actuation of an accelerator pedal or of an actuation of a clutch or of a rotational speed of a drive motor or of a torque of the drive motor or of an inclination of the road.

9. The method according to claim 7 ,
wherein the parameters comprise current values and a time profile of an actuation of an accelerator pedal and of an actuation of a clutch and of a rotational speed of a drive motor and of a torque of the drive motor and of an inclination of the road.

Assignees

• Schwarz Michael
• Schmidt Holger
• Lucas Automotive Gmbh

Inventors

• Schwarz Michael
• Schmidt Holger

Classifications

• F16D65/18

  adapted for drawing members together {, e.g. for disc brakes} · CPC title

• F16D55/226

  in which the common actuating member is moved axially {, e.g. floating caliper disc brakes} · CPC title

• F16D2121/24

  using motors · CPC title

• B60T13/741

  acting on an ultimate actuator · CPC title

• B60T13/746

  and mechanical transmission of the braking action · CPC title