Method and device for operating a brake system of a vehicle, brake system

Patent metadata

Field	Value
Publication number	US-10023165-B2
Application number	US-201615085827-A
Country	US
Kind code	B2
Filing date	Mar 30, 2016
Priority date	Apr 2, 2015
Publication date	Jul 17, 2018
Grant date	Jul 17, 2018

Abstract

A method for operating a brake system of a vehicle, in particular a motor vehicle, including at least one wheel brake having a displaceable brake piston and an electric motor first actuator of a parking brake and a hydraulic second actuator of an operating brake for displacing the brake piston in each case. For operating the parking brake, the electric motor first actuator is activated in order to set a specifiable target clamping force of the wheel brake. If the maximum clamping force that is achievable by the electric motor first actuator is lower than the target clamping force, then the hydraulic second actuator is activated to provide an additional clamping force.

First claim

What is claimed is:

1. A method for operating a brake system of a vehicle including at least one wheel brake having a displaceable brake piston, an electric motor first actuator of a parking brake for displacing the brake piston, and a hydraulic second actuator of an operating brake for displacing the brake piston, the method comprising:
activating the electric motor first actuator to operate the parking brake in order to set a specifiable target clamping force of the wheel brake; and
activating the hydraulic second actuator if the maximum clamping force that is achievable by the electric motor first actuator is lower than the target clamping force in order to provide an additional clamping force,
wherein activating the hydraulic second actuator includes deactivating the electric motor first actuator, which is configured to be self-locking, before the hydraulic second actuator is activated, and
wherein activating the hydraulic second actuator further includes re-activating the electric motor first actuator before the activation of the hydraulic second actuator is ended.

2. The method according to claim 1 , further comprising:
determining the maximum achievable clamping force as a function of at least one of a motor revolution rate, a motor current, and a motor current gradient of the electric motor first actuator.

3. The method according to claim 1 , further comprising:
activating the hydraulic second actuator in order to set a predetermined additional clamping force.

4. The method according to claim 3 , wherein the additional clamping force is predetermined depending on tolerances and/or free travel in the mechanical and/or hydraulic chain of action of the first or of the second actuator, an operating temperature, ageing and/or the efficiency of at least one of the actuators.

5. The method according to claim 1 , further comprising:
ending the activation of the hydraulic second actuator if the target clamping force is reached or exceeded by the clamping force and/or the additional clamping force and/or if a predefinable target displacement distance of the brake piston has been reached.

6. A device for operating a brake system of a vehicle including at least one wheel brake having a displaceable brake piston, an electric motor first actuator of a parking brake for displacing the brake piston, and a hydraulic second actuator of an operating brake for displacing the brake piston, the device comprising:
a controller configured to activate the electric motor first actuator in order to set a specifiable target clamping force of the wheel brake to operate the parking brake, and to activate the hydraulic second actuator if the maximum clamping force that is achievable by the electric motor first actuator is lower than the target clamping force in order to provide an additional clamping force, wherein activating the hydraulic second actuator includes: a) deactivating the electric motor first actuator, which is configured to be self-locking, before the hydraulic second actuator is activated; and b) re-activating the electric motor first actuator before the activation of the hydraulic second actuator is ended.

7. A brake system of a vehicle, comprising:
at least one wheel brake including a displaceable brake piston, an electric motor first actuator of a parking brake for displacing the brake piston, and a hydraulic second actuator of an operating brake for displacing the brake piston; and
a controller configured to activate the electric motor first actuator in order to set a specifiable target clamping force of the wheel brake to operate the parking brake, and to activate the hydraulic second actuator if the maximum clamping force that is achievable by the electric motor first actuator is lower than the target clamping force in order to provide an additional clamping force, wherein activating the hydraulic second actuator includes: a) deactivating the electric motor first actuator, which is configured to be self-locking, before the hydraulic second actuator is activated; and b) re-activating the electric motor first actuator before the activation of the hydraulic second actuator is ended.

Assignees

• Bosch Gmbh Robert

Inventors

• Baehrle-Miller Frank
• Roters Lars
• Schaefer Ulrike

Classifications

• B60T8/17

  Using electrical or electronic regulation means to control braking {(detecting or indicating faulty operation B60T8/885)} · CPC title

• B60T13/588 Primary

  both fluid and mechanical assistance or drive · CPC title

• F16D2125/40

  Screw-and-nut · CPC title

• F16D2121/04

  acting on a piston-type actuator, e.g. for liquid pressure · CPC title

• F16D65/183

  with force-transmitting members arranged side by side acting on a spot type force-applying member · CPC title