Electric brake booster

Patent metadata

Field	Value
Publication number	US-9428169-B2
Application number	US-201214362548-A
Country	US
Kind code	B2
Filing date	Dec 5, 2012
Priority date	Dec 5, 2011
Publication date	Aug 30, 2016
Grant date	Aug 30, 2016

Abstract

An electric brake booster for a vehicle brake system includes a push bar configured to be driven by a brake pedal to move forwards in an axial direction; a brake force outputting element configured to be pushed forwards by the push bar to output a brake force from the brake pedal; a booster force outputting element for outputting a booster force; a motor for driving the booster force outputting element to create the booster force; a poppet configured to be pushed forwards in the axial direction by the push bar with a spring force, wherein the poppet forms a boost switch, through which an electrical current can pass, with the brake force outputting element and forms a release switch, through which another electrical current can pass, with the booster force outputting element; and an electronic control unit for controlling the operation of the motor in responsive to the on-off states of the boost switch and the release switch. The electric brake booster is independent of the vacuum degree of the inlet pipe of the vehicle engine and can provide active and precise control to the actions of the booster.

First claim

The invention claimed is:

1. An electric brake booster for a vehicle brake system, comprising:
a push bar configured to be driven by a brake pedal to move forwards in an axial direction;
a brake force outputting element configured to be pushed forwards by the push bar to output a brake force from the brake pedal;
a booster force outputting element configured to output a booster force;
a motor configured to drive the booster force outputting element to create the booster force;
a poppet configured to be pushed forwards in the axial direction by the push bar with a spring force, wherein the poppet forms a boost switch, through which an electrical current is configured to pass, with the brake force outputting element and forms a release switch, through which another electrical current is configured to pass, with the booster force outputting element; and
an electronic control unit configured to control the operation of the motor in response to the on-off states of the boost switch and the release switch.

2. The electric brake booster of claim 1 , wherein the booster force outputting element has an internal space extending in the axial direction, and the brake force outputting element is disposed in the internal space and configured to be moved relative to the booster force outputting element in the axial direction.

3. The electric brake booster of claim 2 , wherein the booster force outputting element and the brake force outputting element each have a back end facing towards the poppet in the axial direction, the release switch and the boost switch being formed between the back ends of the booster force outputting element and the brake force outputting element and the poppet respectively, and wherein conductive contact is established between each of the back ends of the booster force outputting element and the brake force outputting element and the poppet when the electric brake booster is in a rest position.

4. The electric brake booster of claim 3 , wherein conductive contact is established between each of the back ends of the booster force outputting element and the brake force outputting element and the poppet when the electric brake booster is in a braking position.

5. The electric brake booster of claim 4 , wherein one of the back ends of the booster force outputting element and the brake force outputting element is out of contact with the poppet when the electric brake booster is in an intermediate position between the rest position and the braking position.

6. The electric brake booster of claim 3 , wherein:
the back ends of the booster force outputting element and the brake force outputting element are each configured with a conductive bump protruded towards the poppet; or
the poppet is configured with conductive bumps protruded towards the back ends of the booster force outputting element and the brake force outputting element respectively.

7. The electric brake booster of claim 1 , further comprising a reaction disk disposed between the front ends of the booster force outputting element and the brake force outputting element and a main piston of a primary brake cylinder of the vehicle brake system, wherein the boost force outputted from the booster force outputting element and the brake force outputted from the brake force outputting element are transmitted to the main piston through the reaction disk.

8. The electric brake booster of claim 1 , further comprising a returning spring configured to apply a returning force to the booster force outputting element, the returning force having a tendency of moving the booster force outputting element backwards in the axial direction.

9. The electric brake booster of claim 1 , wherein the motor is coupled to the booster force outputting element via a speed reducing device.

10. The electric brake booster of claim 9 , wherein the motor is a rotary DC motor or a linear DC motor.

Assignees

• Bosch Automotive Products (Suzhou) Co Ltd
• Bosch Gmbh Robert

Inventors

• Zhang Qiusheng

Classifications

• B60T13/745 Primary

  acting on a hydraulic system, e.g. a master cylinder · CPC title