METHOD FOR REDUCING THE CLAMPING FORCE APPLIED BY A PARKING BRAKE

• US 20120245816A1
• Filed: 03/15/2012
• Published: 09/27/2012
• Est. Priority Date: 03/21/2011
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Hauber, Simon, BLATTERT, Dieter
• Granted Patent: US 8,483,923 B2
• Time in Patent Office: Days
• US Class Current: 701/70
• CPC Class Codes: B60T 13/588 both fluid and mechanical assistance or drive
• CPC Class Codes: B60T 13/662 characterised by specified functions of the control system components
• CPC Class Codes: B60T 13/741 acting on an ultimate actuator
• CPC Class Codes: F16D 2121/24 using motors
• CPC Class Codes: F16D 2125/40 Screw-and-nut
• CPC Class Codes: F16D 65/12 Discs; Drums for disc brakes

Abstract

In a method for reducing the clamping force applied by a parking brake, which may be generated at least partially by an electromechanical brake device having an electric brake motor and supplemented if necessary by a hydraulic brake device, a signal is generated for actuating the hydraulic brake device for the case that it is not possible for the brake motor to be released for reducing the clamping force.

Claims

1. A method for reducing a clamping force applied by a parking brake, which is generatable at least partially by an electromechanical brake device having an electric brake motor and supplemented if necessary by a hydraulic brake device, the brake motor displacing a brake piston to which a hydraulic pressure of the hydraulic brake device may be applied, the method comprising:

generating a signal for actuating the hydraulic brake device for the case that it is not possible for the brake motor to be released for reducing the clamping force.

2. The method as recited in claim 1, further comprising:

activating the hydraulic brake device via the signal.

3. The method as recited in claim 1, further comprising:

making, via the signal, a request for actuating the hydraulic brake device.

4. The method as recited in claim 1, wherein the case that it is not possible for the brake motor to be released for reducing the clamping force is preventively established using one of a state of the parking brake or an operating variable of the parking brake.

5. The method as recited in claim 4, wherein the case that it is not possible for the brake motor to be released for reducing the clamping force is present if the hydraulic brake device was actuated with a hydraulic pressure exceeding a limiting value in a preceding engagement of the parking brake.

6. The method as recited in claim 4, wherein the case that it is not possible for the brake motor to be released for reducing the clamping force is present if the parking brake was actuated with maximum brake force in a preceding engagement.

7. The method as recited in claim 4, wherein the case that it is not possible for the brake motor to be released for reducing the clamping force is present if a temperature in the parking brake exceeds a limiting value.

8. The method as recited in claim 4, wherein the case that it is not possible for the brake motor to be released for reducing the clamping force is present if a reengagement was carried out following engagement of the parking brake.

9. The method as recited in claim 4, wherein the case that it is not possible for the brake motor to be released for reducing the clamping force is present if an electrical voltage falls below a limiting value in a vehicle electrical system.

10. The method as recited in claim 1, wherein the case that it is not possible for the brake motor to be released for reducing the clamping force is present if the brake motor blocks after an actuation for reducing the clamping force.

11. The method as recited in claim 10, wherein blocking is recognized if a motor current exceeds a limiting value.

12. The method as recited in claim 10, wherein blocking is recognized if the motor speed falls below a limiting value.

13. The method as recited in claim 1, wherein for the case that it is not possible for the brake motor to be released for reducing the clamping force, one of a drive engine of a vehicle is started, or a request for starting the drive engine is made.

14. A regulating and control unit for reducing a clamping force applied to a parking brake which is generatable at least partially by an electromechanical brake device having an electric brake motor and supplemented if necessary by a hydraulic brake device, the regulating and control device configured to generate a signal for actuating the hydraulic brake device for the case that it is not possible for the brake motor to be released for reducing the clamping force.

15. A parking brake in a vehicle having a regulating and control unit, the regulating and control device for reducing a clamping force applied to a parking brake which is generatable at least partially by an electromechanical brake device having an electric brake motor and supplemented if necessary by a hydraulic brake device, the regulating and control device configured to generate a signal for actuating the hydraulic brake device for the case that it is not possible for the brake motor to be released for reducing the clamping force.