Electrically controlled brake actuator
AssigneeBendix France
InventorEric Fargier
Life of this patent
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Abstract
The actuator (10) of a brake, such as a disc brake, is controlled by an electric motor (34) which drives a pump (38, 50, 62) ensuring that the pressure of the brake fluid in a control chamber (44) rises. A crankshaft (38) driven by the electric motor (34) imparts a to-and-fro movement to a plunger piston (50) in a pumping chamber (62). This chamber (62) communicates with a brake-fluid reservoir via an intake duct (74) controlled by way of a valve (76, 78) and with the chamber (44) via a delivery duct controlled by way of a valve (58, 60). Furthermore, the control chamber (44) communicates with the reservoir via a recycling duct (80) controlled by way of a solenoid valve (82). The entire hydraulic circuit so formed is accommodated in the body (12) of the actuator.
Claims3
An electrically controlled hydraulic disc brake actuator controlled by a brake pedal, said actuator comprising:
- a body having a longitudinal axis parallel to a rotational axis of the disc;
- a brake piston designed to slide parallel to said axis of said body and delimiting a main control chamber together with the body, a cylindrical recess disposed in the brake piston and into which a cylindrical part of said body projects;
- an electric motor connected with said body and having an output shaft with a rotational axis perpendicular to said axis of said body;
- a brake fluid reservoir formed in said body;
- a pressure gauge located in said control chamber for providing signals corresponding to the pressure within said control chamber, said signals being transmitted to an external circuit for comparing a measured pressure value with a theoretical value set according to the position of the brake pedal;
- a pump located within said body and driven by said output shaft of said electric motor, having:
- one plunger piston, a longitudinal axis of which is parallel to said axis of said body,
- an intake duct accommodating an intake valve and communicating with said reservoir,
- a delivery duct accommodating a delivery valve and communicating with said main control chamber, and
- a variable volume pumping chamber partially delimited by one end of said plunger piston the other end of which is connected with said output shaft by means of a crankshaft carried by said output shaft and converting a rotation of said output shaft into reciprocating movement of said plunger piston parallel to said axis of said body, and
- a recycling duct in the body controlled by means of a solenoid valve accommodated in said body and operating to selectively connect said control chamber and reservoir.
An electrically controlled hydraulic disc brake actuator controlled by a brake pedal, said actuator comprising:
- a body having a longitudinal axis parallel to a rotational axis of the disc;
- a brake piston designed to slide parallel to said axis of said body and delimiting a main control chamber together with the body, a cylindrical recess disposed in the brake piston and into which a cylindrical part of said body projects;
- an electric motor connected with said body and having an output shaft with a rotational axis perpendicular to said axis of said body;
- a brake fluid reservoir formed in said body;
- a pressure gauge located in said control chamber for providing signals corresponding to the pressure within said control chamber, said signals being transmitted to an external circuit for comparing a measured pressure value with a theoretical value set according to the position of the brake pedal;
- a pump located within said body and driven by said output shaft of said electric motor, having:
- one plunger piston, a longitudinal axis of which is parallel to said axis of said body,
- an intake duct accommodating an intake valve and communicating with said reservoir,
- a delivery duct accommodating a delivery valve and communicating with said main control chamber, and
- a variable volume pumping chamber partially delimited by one end of said plunger piston the other end of which is connected with said output shaft by means of a crankshaft carried by said output shaft and converting a rotation of said output shaft into reciprocating movement of said plunger piston parallel to said axis of said body,
- a recycling duct in the body controlled by means of a solenoid valve accommodated in said body and operating to selectively connect said control chamber and reservoir, and
- a second control chamber separated from said main control chamber by sealing means formed between a tubular part of said brake piston surrounding said recess and a cylinder which belongs to the body and in which said tubular part of said brake piston slides.
Dependencies are inferred from the claim text.