Road vehicle electrohydraulic brake system

US5722744A · kind A · utility

Assignee

• Mercedes-Benz Group AG · DE

Inventors

• Walter Kupfer · Waiblingen, DE
• Harry Troester · Tamm, DE

Key dates

• Filing date: Jun 26, 1996
• Grant date: Mar 3, 1998
• Expiry date: Jun 26, 2016

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F16K37/00
• WIPO field: Transport
• WIPO sector: Mechanical engineering

Abstract

In a road vehicle electrohydraulic brake system, each wheel brake is assigned a brake-pressure regulating element which can be controlled by an electric motor. At least one electronic retardation desired-value signal transmitter is actuated by the driver. An electronic control unit produces the required actuating signals for the brake-pressure regulating elements from a comparison of the desired-value input signals with actual-value signals characteristic of the vehicle retardation. The brake-pressure regulating elements each comprises a piston pump. The filling and delivery strokes of these elements are performed in a fixed phase relationship with a pump driving element. The output of the pump per pump cycle is regulated opposite the pressure and, in all cases, is small relative to the output, Q.sub.max, required for coupling the maximum value of the brake pressure P.sub.Bmax into the connected wheel brake. With the vehicle stationary and the desired-value transmitter actuated, an electrically drivable valve arrangement shuts off the brakes from the brake-pressure regulating elements and, given a reduction in the desired-value input, allows brake fluid to flow out of the brakes in…