Hybrid electro-mechanical brake and system having the same

Patent metadata

Field	Value
Publication number	US-2016137181-A1
Application number	US-201514871538-A
Country	US
Kind code	A1
Filing date	Sep 30, 2015
Priority date	Nov 18, 2014
Publication date	May 19, 2016
Grant date	—

Abstract

A hybrid electro-mechanical brake (EMB) includes an actuator mounted at one side of a housing and generating a motor clamping force. A primary piston is connected to a spindle, which rotates by a motor clamping force of the actuator, to linearly move when the spindle rotates. A secondary piston linearly moves and is mounted between the housing and the primary piston to form a hydraulic chamber between the second piston and the primary piston. The hybrid EMB system generates a brake force by using the motor clamping force of the actuator and a hydraulic pressure in a hydraulic chamber. The actuator actuates to move the primary piston toward a front end of the secondary piston to increase a pressure in the hydraulic chamber, which is sealed, so that the brake force transferred to the secondary piston increases.

First claim

What is claimed is:

1 . A hybrid electro-mechanical brake (EMB), comprising:
an actuator mounted at one side of a housing and generating a motor clamping force; a primary piston connected to a spindle, which rotates by a motor clamping force of the actuator, to linearly move when the spindle rotates; and a secondary piston linearly moving and mounted between the housing and the primary piston to form a hydraulic chamber between the second piston and the primary piston, wherein the motor clamping force of the actuator and a hydraulic pressure in a hydraulic chamber generate a brake force, and wherein the actuator actuates to move the primary piston toward a front end of the secondary piston to increase a pressure in the hydraulic chamber which is sealed, so that the brake force transferred to the secondary piston increases.

2 . The hybrid EMB of claim 1 , wherein the brake force transferred to the secondary piston is proportional to an area ratio of the primary piston and the secondary piston and is calculated by the following equation:
motor clamping force of actuator×(area of front end of secondary piston/area of front end of primary piston).

3 . The hybrid EMB of claim 1 , further comprising: a reaction damper disposed inside the secondary piston at the front end thereof between the primary piston and the secondary piston and transferring the motor clamping force and the pressure in the hydraulic chamber.

4 . The hybrid EMB of claim 3 , wherein the reaction damper includes:
an external outer member made of rubber so that when the primary piston moves toward the secondary piston, the motor clamping force is converted into the pressure in the hydraulic chamber by elasticity; and an internal inner member made of steel to prevent excessive deformation of the reaction damper.

5 . The hybrid EMB of claim 3 , wherein the reaction damper includes:
an external outer member made of rubber, so that the motor clamping force is switched into the pressure in the hydraulic chamber when the primary piston moves toward the secondary piston; the internal inner member made of steel to prevent deformation of the reaction damper; and a joining protrusion inserted and fixed into an inner wall surface of the front end of the secondary piston, the joining protrusion protruding on an outer peripheral surface of the outer member to increase mountability in the secondary piston.

6 . The hybrid EMB of claim 1 , further comprising:
a guide mounted at one side of the actuator and disposed between the primary piston and the secondary piston to convert the rotating motion of the spindle into a linear motion of the primary piston, the guide guiding the linear motion of the secondary piston.

7 . A hybrid EMB system, comprising:
a hybrid EMB generating a brake force together with a hydraulic apparatus; a wheel control unit (WCU) configured to control the hybrid EMB; and a solenoid valve opening and closing a hydraulic line between the hydraulic apparatus and the hybrid, wherein the hybrid EMB includes:
an actuator mounted at one side of a housing and generating a motor clamping force;
a primary piston connected to a spindle, which rotates by a motor clamping force of the actuator, to linearly move when the spindle rotates; and
a secondary piston linearly moving and mounted between the housing and the primary piston to form a hydraulic chamber between the second piston and the primary piston.

Assignees

• Hyundai Motor Co Ltd

Inventors

• Shim Jae Hun
• Shim Sang Hyun
• Lee Joung Hee
• Jeon Gab Bae

Classifications

• B60T7/042 Primary

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

• B60T13/745 Primary

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

• B60T13/686

  in hydraulic systems or parts thereof · CPC title

• B60T13/741

  acting on an ultimate actuator · CPC title

• B60T13/74 Primary

  with electrical assistance or drive · CPC title