Brake system for motor vehicles

Patent metadata

Field	Value
Publication number	US-9802590-B2
Application number	US-201113988211-A
Country	US
Kind code	B2
Filing date	Nov 17, 2011
Priority date	Nov 26, 2010
Publication date	Oct 31, 2017
Grant date	Oct 31, 2017

Abstract

The invention relates to a brake system for motor vehicle. A piston-cylinder arrangement can be actuated by means of a brake pedal, a controllable pressure source and brake pressure modulation valves. In order to provide a piston-cylinder arrangement which is easy to implement and axially short, the invention proposes that the piston of the piston-cylinder arrangement is directly guided in a housing that accommodates further components of the brake system according to the invention.

First claim

The invention claimed is:

1. A brake system for a motor vehicle which, in a brake-by-wire operating mode, can be activated both by the vehicle driver and also independently of the vehicle driver, and is normally operated in the brake-by-wire operating mode and can be operated in at least one fall-back operating mode in which only operation by the vehicle driver is possible, comprising:
a brake pedal for actuating a hydraulic piston-cylinder arrangement having a hydraulic piston on which an actuating force is exerted when the brake system is actuated by the vehicle driver and which is guided directly and displaceably in a housing along an actuation axis,
a hydraulically actuable pedal travel simulator which is releasable and blockable by means of a simulator release valve,
a travel detection device which detects the actuation travel of the hydraulic piston,
a pressure medium reservoir,
an electrically controllable pressure source which delivers a brake system pressure,
a pressure modulation unit having electrically controllable pressure regulating valves for adjusting wheel-individual brake pressures which are derived from the brake system pressure of the electrically controllable pressure source, the brake system pressure of the electrically controllable pressure source being supplied via a brake system pressure line to inlet connections of the pressure regulating valves which deliver or transmit the brake system pressure of the electrically controllable pressure source through the pressure regulating valves when the pressure regulating valves are in an unenergized state, wherein the pressure regulating valves are open in the unenergized state to allow fluid to flow from the brake system pressure line toward the corresponding wheel brake and closed in an energized state to prevent fluid from flowing from the brake system pressure line toward the corresponding wheel brake;
dividing piston devices which are associated with each of the motor vehicle wheel brakes of the vehicle and are subjected on a first dividing piston surface to the wheel-individual brake pressure set or transmitted by the pressure regulating valves and which transmit the wheel-individual brake pressure exerted by a second dividing piston surface to the motor vehicle wheel brakes,
activating elements for exerting the actuating force or for mechanically activating the dividing piston devices, which activating elements can be brought into force-transmitting connection with the piston, and
an electronic control and regulation unit.

2. The brake system as claimed in claim 1 , further comprising in that the piston is guided in the housing by means of a radial collar formed on the piston which serves to transmit force to the activating elements associated with the dividing piston devices.

3. The brake system as claimed in claim 2 , further comprising in that an axial free clearance which corresponds to the possible actuation travel of the brake pedal in the brake-by-wire operating mode is provided between the collar and the activating elements.

4. The brake system as claimed in claim 1 further comprising in that a hydraulic connection which is blockable by electromagnetically actuable shut-off valves is provided between the piston-cylinder arrangement and the brake system pressure line.

5. The brake system as claimed in claim 4 , further comprising in that the hydraulic connection is blocked in the brake-by-wire operating mode and is open in the fall-back operating mode.

6. The brake system as claimed in claim 4 further comprising in that the hydraulic connection has a section of dual-circuit configuration, one of the dual circuits being blockable separately with one of the shut-off valves and the other of the dual circuits being blockable with another of the shut-off valves.

7. The brake system as claimed in claim 1 , further comprising in that a first pressure sensor is provided for detecting pressure of the piston-cylinder arrangement and a second pressure sensor is provided for detecting the brake system pressure.

8. The brake system as claimed in claim 1 , further comprising in that a sensor, providing a signal of which represents the discharge volume of the electrically controllable pressure source.

9. The brake system as claimed in claim 8 , further comprising in that the sensor is in the form of a travel or an angle sensor which detects a travel distance or a rotational angle of an actuator of the electrically controllable pressure source.

10. The brake system as claimed in claim 1 , further comprising in that the electrically controllable pressure source is hydraulically connected to the brake system pressure line via an electromagnetically actuable valve which can be shut off in the flow direction to the pressure source.

11. A brake system for a motor vehicle which, in a brake-by-wire operating mode, can be activated both by the vehicle driver and also independently of the vehicle driver, and is normally operated in the brake-by-wire operating mode and can be operated in at least one fall-back operating mode in which only operation by the vehicle driver is possible, comprising:
a brake pedal for actuating a hydraulic piston-cylinder arrangement having a hydraulic piston on which an actuating force is exerted when the brake system is actuated by the vehicle driver and which is guided directly and displaceably in a housing along an actuation axis,
a hydraulically actuable pedal travel simulator which is releasable and blockable by means of a simulator release valve,
a travel detection device which detects the actuation travel of the hydraulic piston,
a pressure medium reservoir,
an electrically controllable pressure source which delivers a brake system pressure,
a pressure modulation unit having electrically controllable pressure regulating valves for adjusting wheel-individual brake pressures which are derived from the brake system pressure, the brake system pressure being supplied via a brake system pressure line to inlet connections of the pressure regulating valves which deliver or transmit the brake system pressure in an unactivated state,
dividing piston devices which are associated with each of the motor vehicle wheel brakes of the vehicle and are subjected on a first dividing piston surface to the wheel-individual brake pressure set or transmitted by the pressure regulating valves and which transmit the wheel-individual brake pressure exerted by a second dividing piston surface to the motor vehicle wheel brakes,
activating elements for exerting the actuating force or for mechanically activating the dividing piston devices, which activating elements can be brought into force-transmitting connection with the piston, and
an electronic control and regulation unit,
wherein the pedal travel simulator is connected, via a simulator release valve which blocks the flow direction to the pedal travel simulator when unenergized, to a hydraulic line section which is hydraulically connected, via a first shut-off valve which is open when unenergized, to a hydraulic connection that extends from the piston-cylinder arrangement, and via a second shut-off valve which is open when unenergized, to the brake system pressure line.

12. The brake system as claimed in claim 11 , further comprising in that the shutting-off of the simulator release valve when unenergized can be tested by being subjected to a test pressure while neither the hydraulic piston-cylinder arrangement, nor the dividing piston devices together with the connected wheel brakes, are subjected to the test pressure.

13. The brake system as claimed in claim 12 , wherein, in order to test fluid-tightness of the unenergized simulato

Assignees

• Drumm Stefan A
• Continental Teves Ag & Co Ohg

Inventors

• Drumm Stefan A

Classifications

• B60T8/4077

  Systems in which the booster is used as an auxiliary pressure source · CPC title

• B60T13/686

  in hydraulic systems or parts thereof · CPC title

• B60T11/20

  Tandem, side-by-side, or other multiple master cylinder units · CPC title

• B60T7/042 Primary

  by electrical means, e.g. using travel or force sensors · CPC title

• B60T13/14 Primary

  using accumulators or reservoirs {fed by pumps} · CPC title