Aisin Seiki Kabushiki Kaisha

Toshihiro Nakano

Akimoto Okada

Hideaki Iijima

Shinji Sakata

Kaoru Tsubouchi

Hitoshi Ichioka

Haruo Arakawa

Hiromu Kuromitsu

Hitoshi Tauchi

Naoyasu Enomoto

Yasuyuki Hanai

Atsushi Yasuda

Kiyohiko Minagawa

A master cylinder includes a cylinder housing having a rearwardly opening inner bore, a piston having a forwardly opening bore positioned in the inner bore of the cylinder housing, a spring disposed in the inner bore of the piston, a stopper supporting a front end of the spring, a retainer disposed in the inner bore of the piston and supporting a rear end of the spring, and a rod connecting the retainer and the stopper while allowing the spring to compress in the axial direction. A plurality of projection portions are formed on the outer circumferential portion of the retainer and the retainer is pressed into the inner bore of the piston via the projection portions.

Master cylinder

A brake master cylinder which prevents a contact between a projection of a spring retainer and a stopper of a sleeve when a piston is suddenly retracted by an operation of a pressure applying device of a brake system or by an air relieving operation to offer a high reliability without deformation and damages of the spring retainer and the sleeve. A groove extended in axial direction is provided on the sleeve. A distance between a rear end surface of the groove and a radial projection of a first spring retainer when the brake is not applied corresponds to the total of a distance of a retracting distance of a second piston from the position defined by the non-braking operation to a position where a piston port and an opening of a reservoir communication conduit are overlapped and a predetermined additional distance.

Brake master cylinder

The object of the present invention is to provide a brake fluid pressure generating apparatus which has a master cylinder with supplemental pressure room which operates the master cylinder independently of a depression of a brake pedal without structure complication. To perform this object, a master cylinder piston slides over seal cups which are arranged on a master cylinder side.

Brake fluid pressure generating apparatus

A brake master cylinder for a vehicle brake system in which the assembling precision of a guide and a cup seal, the structure of a communication conduit, and the structure of a cylinder cap and the guide are improved to thereby improve the performance of the brake master cylinder while also reducing the cost and improving the sealing structure between a body and the cylinder cap to thus reduce the size of the cylinder cap. The brake master cylinder includes the cylinder cap positioned in an internal bore opening portion of the body, a first piston inserted into a cylinder housing through the cylinder cap and slidably supported by the guide in the axial direction, a second piston positioned coaxially with the first piston at the front of the first piston and slidable in the axial direction in the cylinder housing, and a cup seal at the front of the guide for liquid-tightly sealing a first pressure chamber formed between the first piston and the second piston. The guide and the cup seal coaxially engage the inner bore of the cylinder cap.

A brake master cylinder includes a cylinder housing formed by a cylinder body and a cap, a first guide member, a second guide member, a sleeve, a first piston and a second piston. To achieve accurate concentricity between a bore of the first guide member and a bore of the sleeve, and between a bore of the second guide member and the bore of the sleeve, the first guide member is coaxially provided in a bore of the cap, the second guide member is coaxially provided in the cylinder bore and has a first bore at its front side and a second bore at its rear side, and the sleeve is coaxially fitted into the bore of the cap at its rear end and is coaxially fitted into the second bore of the second guide member at its front end. The first piston is fitted into the cylinder housing and is slidably supported in the axial direction by the bore of the first guide member and the bore of the sleeve, the second piston is provided in front of the first piston coaxially and is slidably supported in the axial direction by the first bore of the second guide member and the bore of the sleeve.

A master cylinder having variable input/output characteristics includes a cylinder body in which is formed a cylinder bore and a piston fitted in the cylinder bore and movable upon brake operation. The piston is divided into a front portion and a rear portion, with a pressure chamber being defined at the front side of the front portion and an auxiliary chamber being defined at the rear side of the front portion. The auxiliary pressure chamber is located at the same position as the rear portion of the piston. A first changeover valve is provided between the auxiliary pressure chamber and the pressure chamber to establish and interrupt fluid communication between the auxiliary pressure chamber and the pressure chamber.

Master cylinder for automotive vehicle

In a master cylinder for drawing brake fluid from a reservoir through a pressure generating chamber in the master cylinder during fluid pressure control to supply brake pressure to a wheel cylinder, a check valve is provided for securing sufficient suction from the master cylinder. The check valve is operational to communicate the supply chamber and the pressure generating chamber with each other only when the pressure generating chamber is under a negative pressure while the piston is in a non-operating position. The check valve is arranged within the inner portion of the piston and along the axis of the piston.

The invention is directed to a wheel braking system having a master cylinder and a wheel brake cylinder which is communicated with the master cylinder through a brake fluid supply passage, and which is operatively mounted on a wheel for applying a braking force to the wheel. A suction device, such as a fluid pump, is provided for producing a negative pressure in the wheel brake cylinder. An initial pressure supply device, such as an accumulator, is also provided for supplying a predetermined amount of the brake fluid into the wheel brake cylinder when the braking operation is initiated. Accordingly, brake pads for braking the wheel may be separated from a brake rotor or brake drum respectively with a predetermined clearance, and the amount of the brake fluid which is consumed by the master cylinder when the braking operation is initiated, is not increased.

Wheel braking system with a retracting apparatus

A master cylinder includes a cylinder body including a cylinder portion, a piston fit into the cylinder portion so as to fluid-tightly divide the cylinder portion into a pressure chamber and a supply chamber, a connecting passage which is disposed in the piston and which connects the pressure chamber with the supply chamber, a valve mechanism which is mounted on the piston and which disconnects the connecting passage when the piston is moved for a predetermined distance and a restriction member installed in the connecting passage for restricting a flow of a fluid from the pressure chamber into the supply chamber when the piston is operated and allowing the flow of the fluid from the supply chamber into the pressure chamber when the piston is returned.

Master cylinder having restriction means with piston

The present invention is directed to a cap assembly for screwing into an opening of a reservoir for storing a fluid therein. Around the cap, formed is a sealing groove in which a sealing member is disposed. The sealing member has a sealing portion which extends toward the inner periphery of the opening, and a pair of contacting portions which extend axially toward each inner side of the sealing groove in spaced relationship with each inner side of the sealing groove by a predetermined clearance respectively. The sealing member is formed around the periphery thereof with grooves for allowing the sealing portion and contacting portions to be deflected in response to a sliding motion of the sealing member when the cap assembly is screwed into the opening.

Reservoir cap having a sealing member

A reservoir tank includes a tank body storing an amount of operating fluid and having an inlet, a cap detachably mounted on the inlet of the tank body, a deflector secured to the cap so as to be located in the inlet and having a first passage which is in fluid communication with the atmosphere and a second passage which is in fluid communication with an inner space of the tank body, a diaphragm located between the cap and the deflector and having a slit valve which is set to be opened by a pressure difference thereacross, and an interruption body located between the deflector and the diaphragm so as to oppose to the second passage of the deflector and having a passage which enabling the fluid communication between the second passage of the deflector and the slit.

Reservoir tank

A reservoir tank according to the present invention is comprised of a tank body storing an amount of operating fluid, connected to a specific device for supplying thereinto the operating fluid and having a bottom with a hole isolated from the operating fluid; a float movable in the vertical direction according to the variation of the liquid level of the operating fluid; a magnet secured to a lower end of the float; and a reed switch unit assembly having a reed switch with a pair of terminals, a pair of conducting elements connected to the pair of terminals of the reed switch, a connector casing, and a pair of connectors each of which is secured to one end of the connector casing in such a manner that each connector is electrically connected to the respective conducting element.

Reservoir tank including float with reed switch unit

A reservoir cap includes a cylinder portion of molded resin and surrounding an outer circumferential surface of an opening portion of a reservoir body, and a flat portion unitarily formed on the cylinder portion and closing the opening portion of the reservoir body. A transparent film is insert-molded to the outer surface of the flat portion. Descriptive characters are formed at an inner surface of the film. The film is made from the same material as the flat portion. It is therefore possible to obtain a high adhesion between the film and the flat portion of the reservoir cap because they have the same melting point. Therefore, it is possible to provide an improved reservoir cap having descriptive characters which are easily seen from the outside thereof at the flat portion, while ensuring a high chemical resistance and a high durability against the operational fluid. Furthermore, it is possible to improve the appearance of the reservoir cap while ensuring the high chemical resistance and the high durability against the operational fluid.

Reservoir cap

A master cylinder is provided with an arrangement which prevents a valve from being held in a closed and inoperative position by residual pressure in the system. By preventing the valve from being held in the closed position, residual pressure can be released from the cylinder and prevent brake fluid pressure from disabling the brake system.

A master cylinder includes a valve that is slidably mounted in a movable piston means for limited axial movement therein between a closed position wherein the valve is sealingly engaged with the piston and an open position wherein a gap is maintained between the valve and the piston. The valve includes a passage for providing fluid communication between the supply chamber and the pressure chamber when the valve is in the open position. An orifice in the piston limits the flow of fluid from the pressure chamber to the supply chamber at least during the limited movement of the valve from the open position to closed position. An overflow arrangement on the piston is responsive to movement of the piston against the bias of a biasing device for establishing fluid communication between the passage and the supply chamber only when the valve is in the closed position.

Growing community of inventors

Chiryu, Japan

Toshihiro Nakano