Brake system having a blending capability

Patent metadata

Field	Value
Publication number	US-10112589-B2
Application number	US-201515328750-A
Country	US
Kind code	B2
Filing date	Jul 23, 2015
Priority date	Aug 1, 2014
Publication date	Oct 30, 2018
Grant date	Oct 30, 2018

Abstract

A brake system for a motor vehicle includes separate first and second brake circuits associated to first and second vehicle axles, respectively, and rigidly connected to each other. Hydraulic brake pressure is supplied by a first brake piston of a master cylinder to the first brake circuit and by a second brake piston to the second brake circuit. Operably connected to the first vehicle axle is an electric motor and operates as a recuperator, with a blending device withdrawing hydraulic fluid from the first brake circuit during a recuperation phase of the electric motor. A partition wall between the first and second brake pistons subdivides the master cylinder into a first pressure chamber associated to the first brake piston, and a separate second pressure associated to the second brake piston. A connectable and disconnectable floating piston enables a hydraulic communication between the first and second brake circuits with one another.

First claim

What is claimed is:

1. A brake system for a motor vehicle, said brake system comprising:
a first brake circuit associated to a first vehicle axle;
a second brake circuit associated to a second vehicle axle and separate from the first brake circuit;
a hydraulic brake including a master cylinder, said master cylinder comprising a first brake piston supplying the first brake circuit with hydraulic brake pressure, and a second brake piston supplying the second brake circuit with hydraulic brake pressure, said first and second brake pistons being rigidly connected to each other;
an electric motor operably connected to the first vehicle axle and configured to operate as a recuperator;
a blending device configured to withdraw hydraulic fluid from the first brake circuit during a recuperation phase of the electric motor;
a partition wall formed in the master cylinder between the first and second brake pistons to subdivide the master cylinder into a first pressure chamber which is associated to the first brake piston, and a second pressure chamber which is separate from the first pressure chamber and associated to the second brake piston; and
a floating piston operably connected to the first and second brake circuits by way of a valve to disable or enable a hydraulic communication between the first and second brake circuits with one another depending on whether a pressure difference exists between the first pressure chamber and the second pressure chamber.

2. The brake system of claim 1 , wherein the blending device is configured as an actuator, and further comprising an electric control unit configured to electrically activate the actuator.

3. The brake system of claim 2 , further comprising a detection device configured to communicate with the control unit and to determine a recuperation torque provided by the recuperator, when a driver initiates a braking operation, said control unit activating the actuator such as to withdraw hydraulic fluid from the first brake circuit sufficient to reduce the brake pressure in the first brake circuit by a braking partial pressure corresponding to the recuperation torque.

4. The brake system of claim 2 , wherein the actuator is a mechanically-operated actuator.

5. The brake system of claim 1 , further comprising a brake booster configured to actively influence a brake pedal force.

Assignees

• Audi Ag

Inventors

• Klinger Thomas
• Schmid Wolfgang

Classifications

• B60T13/746

  and mechanical transmission of the braking action · CPC title

• B60T17/226

  using devices being responsive to the difference between the fluid pressions in conduits of multiple braking systems · CPC title

• B60T2270/604

  Merging friction therewith; Adjusting their repartition · CPC title

• B60T8/267 Primary

  for hybrid systems with different kind of brakes on different axles · CPC title

• B60T1/10

  by utilising wheel movement for accumulating energy, e.g. driving air compressors · CPC title