Hitachi, Ltd.

Hitachi Automotive Systems, Ltd.

Takuya Obata

Takayuki Ohno

Yukio Ohtani

Daisuke Yasukawa

Hirofumi Watanabe

Toshiyuki Innami

Kimio Nishino

Hirotaka Oikawa

Norikazu Matsuzaki

Masayuki Kikawa

Hideaki Ishii

Toshio Takayama

Kenji Kikuchi

Shoichi Tsuchiya

Hirohumi Watanabe

Naoki Shirakawa

Yasuo Karasudani

Provided is a brake controller which can be made smaller. The brake controller () has a hydraulic control mechanism (), which comprises a master cylinder () which generates a hydraulic fluid pressure on the basis of an input piston () and a control piston () that move when a braking operation is performed, motors (), and a moving mechanism () which moves the aforementioned control piston as the aforementioned motors turn, and a motor control unit () for regulating the turning of the aforementioned motors. The brake controller is characterized in that the aforementioned motor control unit () has a metal case () with a built-in control circuit, the aforementioned metal case () is affixed to the housing () of the aforementioned moving mechanism (), one end of the aforementioned case () is placed at approximately the same position as an end of the aforementioned moving mechanism () in the axial direction of the aforementioned input piston (), and the other end of the aforementioned case () is placed at approximately the same position as an end of the aforementioned master cylinder ().

Brake controller

An object of the present invention is to provide an electric booster enabling an easy connection of an ECU and a stator. An ECU casing containing boards and (ECU) is attached to the outer surface of the casing body so as to be located near a stator of an electric motor. The opening of the casing body is closed by a rear cover. A flat-portion through-hole (through-hole) is formed through the casing body. Bus bars connecting the stator and the ECU are disposed through the flat-portion through-hole. The bus bars are disposed such that one ends thereof are coupled with the stator while the other ends thereof protrude from the flat-portion through-hole. When the electric booster is assembled, since the stator and the bus bars are disposed at the casing body having the flat-portion through-hole, it is possible to easily assemble the casing body and the rear cover with the bus bars inserted through the flat-portion through-hole.

Electric booster

An electric booster in which a rotation of an electric motor is converted into linear motion and transmitted to an output member by a rotation-linear motion mechanism. The output member pushes a piston of a master cylinder to generate brake fluid pressure in a pressure chamber in the master cylinder. An ECU casing containing boards is coupled to the top of a motor casing constituting the electric motor. The ECU casing is offset in one direction in a plane perpendicular to a plane containing an axis of the master cylinder. A male connector is provided at a side surface of the ECU casing on the opposite side from the offset direction side, and a space between the male connector and an interference area of the ECU casing is utilized as a space for attachment/detachment of the male connector.

A brake control system that enables accurate brake control is provided that precisely detects a master-cylinder pressure and includes a back-up function. The brake control system includes a master-cylinder operated by a brake operation of a driver; a first mechanism that regulates a pressure inside the master-cylinder according to the brake operation amount; a first control apparatus that controls operation of the first mechanism; a second mechanism that regulates communication of the pressure inside the master-cylinder to a wheel-cylinder; and a second control apparatus that controls operation of the second mechanism and operation of a pump apparatus that increases a pressure communicated to the wheel-cylinder. The first and second control apparatuses each have a power supply circuit and CPU. The brake control system further includes a first hydraulic pressure sensor that measures a pressure inside the master-cylinder and is electrically connected to the first control apparatus, and a second hydraulic pressure sensor that measures a pressure inside the master-cylinder and is electrically connected to the second control apparatus.

Brake control system

A disc brake apparatus including a disc brake having a parking brake mechanism operated by an electric motor as a drive source to mechanically hold a piston in a braking position even after the hydraulic pressure is released; and a controller for supplying a predetermined amount of hydraulic pressure from a hydraulic control unit to caliper caliper, based on a parking-brake indicating signal from a parking brake switch and for operating the parking brake mechanism. In a case in which a brake pedal is being operated when a parking-brake indicating signal is input, the parking brake mechanism is operated in a state in which a hydraulic pressure in the caliper is at a predetermined pressure, after the operation of the brake pedal is finished, so as to reduce a hydraulic pressure required for a release of a brake pedal.

Disc brake apparatus

The present invention relates to an electric booster in which a rotation of an electric motor is converted into a linear motion and transmitted to an output member by a rotation-linear motion mechanism, and the output member pushes a piston of a master cylinder to generate a brake fluid pressure in a pressure chamber in the master cylinder. The present invention is characterized in that an ECU casing containing boards and the like such as a board for controlling the electric motor is coupled to the top of a motor casing constituting the electric motor. The ECU casing is offset in one direction in a plane perpendicular to a plane containing an axis of the master cylinder. A male connector is provided at a side surface of the ECU casing on the opposite side from the offset direction F side, and a space between the male connector and an interference area of the ECU casing with the other components and devices is utilized as a space for attachment/detachment of the male connector to/from the female connector.

An electric booster which drives an electric motor () in response to a movement of an input member () moving together with a brake pedal (B), and generates a brake hydraulic pressure in a master cylinder () through a ball screw mechanism (). The electric motor () includes a stator () having a coil therein, a rotor () which rotates by applying current to the stator (), and an annular motor casing () containing the stator () and the rotor (). The ball screw mechanism () is fittedly disposed in the rotor (). An opening () on one axial end side of the motor casing () has a larger diameter than an outer diameter of the ball screw mechanism (). In manufacturing, after the electric motor () alone is tested, the ball screw mechanism () is inserted through the opening () and installed without the need of disassembling the motor casing ().

Electric booster and method for manufacturing the same

The present invention relates to an electrically driven brake booster in which boost control is performed as follows; when an input piston is displaced forward by an input rod upon an operation of a brake pedal, an electric motor is operated according to the input, and a primary piston is displaced forward by a ball-screw mechanism, and then a primary and secondary pressure chamber in a master cylinder main body are pressurized. A first seal and a second seal are disposed at a seal portion between the primary piston and the input piston. A portion between the first seal and the second seal is in communication with an outside through a discharge passage. Brake fluid which leaks from the first seal is sealed off by the second seal, and is discharged to the outside through the discharge passage, whereby it becomes possible to prevent that the electric motor and the ball-screw mechanism otherwise might be corroded by the leaking brake fluid.

Electrically driven brake booster

A disk brake with a parking brake mechanism capable of exerting a large piston thrust required for operating a parking brake, without adversely affecting operation of a service brake. A parking brake mechanism, which is driven by an electric motor provided outside a housing, is incorporated in a caliperin which a pistonis slidably disposed in a cylinder. The parking brake mechanismis slidably fitted via a seal memberinto the pistonand provided with a nut memberthat is prevented from rotating relative to the pistonby engagement of a pinand a pin hole; and a shaftthat is screwed into the nut member. During a service brake operation, the pistonalone is moved by a hydraulic pressure under a small piston thrust. During a parking brake operation, the pistonand the nut memberare moved together by applying a hydraulic pressure and operating the electric motor at the same time, to exert a large piston thrust, by using a large pressure receiving area of the pistonand the nut membercombined.

Growing community of inventors

Minami-Alps, Japan

Takuya Obata