US 12,459,481 B2
Detecting air in a brake master cylinder and bleeding the brake master cylinder of a hydraulic power brake system
Erwin Reinke, Neuenstadt Am Kocher (DE); Otmar Bussmann, Abstatt (DE); Carsten Thierer, Abstatt (DE); Kevin Wodrich, Erlenbach (DE); Ralf Kinder, Auenstein (DE); and Tim-Philipp Jesse, Sachsenheim (DE)
Assigned to ROBERT BOSCH GMBH, Stuttgart (DE)
Filed by Robert Bosch GmbH, Stuttgart (DE)
Filed on Jun. 14, 2022, as Appl. No. 17/839,960.
Prior Publication US 2023/0029398 A1, Jan. 26, 2023
Int. Cl. B60T 17/22 (2006.01); B60T 8/40 (2006.01); B60T 13/68 (2006.01)
CPC B60T 17/22 (2013.01) [B60T 17/222 (2013.01); B60T 8/4081 (2013.01); B60T 13/686 (2013.01); B60T 2270/10 (2013.01); B60T 2270/88 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A method for a hydraulic power brake system, the hydraulic power brake system including a brake master cylinder, a brake fluid reservoir with which the brake master cylinder communicates in a non-actuated state and does not communicate in an actuated state, a pressure sensor, a power brake pressure generator, an isolation valve via which the brake master cylinder is connected to a brake circuit of the power brake system, and a power valve via which the power brake pressure generator is connected to the brake circuit of the power brake system, the method comprising:
measuring, on actuation of the brake master cylinder and using the pressure sensor, a brake master cylinder pressure;
comparing the measured brake master cylinder pressure with a comparison value for brake master cylinder pressure which prevails in the actuated brake master cylinder when it is air-free; and
in response to a deviation of the measured master cylinder pressure from the comparison value, bleeding the brake master cylinder in a state of the hydraulic power brake system in which the brake master cylinder is non-actuated, the isolation valve is open, and the power valve is open, the bleeding being performed by the power brake pressure generator conveying brake fluid through the brake master cylinder into the brake fluid reservoir.