Aisin Seiki Kabushiki Kaisha

Toyota Jidosha Kogyo Kabushiki Kaisha

Kabushiki Kaisha Toyota Chuo Kenkyusho

Toyota Jidosha Kabushiki Kaisha

Kaoru Nakamura

Kaoru Tsubouchi

Junzo Hasegawa

Masatoshi Yamada

Eiichi Yasuda

Chiaki Ochiai

Kenji Shirai

Haruo Arakawa

Hiroyuki Kondo

Genji Mizuno

Shigeru Sakamoto

Shinji Sakata

Yoichi Furuta

Toshiya Shibata

Takehiro Inoue

Akira Funabashi

A hydraulic braking pressure control apparatus for an automotive vehicle includes a master cylinder mounted on a brake booster for applying a braking force, a master cylinder reservoir provided on the master cylinder for supplying hydraulic fluid to the master cylinder, and a solenoid valve body mounted on the master cylinder. The solenoid valve body includes a plurality of solenoid valves and a fluid circuit operatively connected to the master cylinder for generating a braking pressure to be supplied to wheel brake cylinders. A pump body is mounted on the master cylinder and includes a pump device for returning hydraulic fluid to the master cylinder and the solenoid valve body. A pump motor drives the pump device, with the pump motor being mounted on the master cylinder and being symmetrically disposed with respect to the solenoid valve body.

Hydraulic braking pressure control apparatus for an automotive vehicle

A master cylinder includes a second piston that is provided with a hollow portion. The hollow portion includes a yoke portion for receiving an end of the second return spring, a cylindrical portion having a diameter that is larger than the diameter of the second return spring, and a tapered portion located at the open end of the hollow portion. The second return spring is disposed within the yoke portion so that the second return spring is coaxially arranged with respect to the second piston. Thus, although the second return spring is capable of moving rapidly to and fro within the hollow portion, the construction of the second piston and the arrangement of the second return spring within the hollow portion of the second piston helps avoid interference between the second piston and the second return spring. Thus, unpleasant noise can be reduced or eliminated. Moreover, small particles that would normally result when the second return spring scratches the second piston are not as likely to arise.

Master cylinder

A master cylinder for use in automotive hydraulic brake device has a pressure liquid chamber formed at one side of the larger diameter portion of the piston and a supply liquid chamber formed between the other side of the large diameter portion of the piston and a ring-shaped cup seal. The inner lip of the ring-shaped cup seal is integrally formed at its distal end with an annular projection coming into contact with a cup seal locking member, which is inserted in the large diameter portion of the cylinder and serves to prevent a movement of the ring-shaped cup seal towards the supply liquid chamber, so that the deformation of the inner lip is restrained.

Static cup seal assembly for master cylinder end

A relief valve used for hydraulic devices such as the master cylinder for motor vehicles, comprising a housing for passing hydraulic fluid therethrough to adjust the hydraulic pressure, a ball valve disposed in the housing, a coil spring for pushing the ball valve in the housing and plural finger-like portions formed in the inside of the housing to resiliently nip the ball valve so as to prevent the vibration of ball valve in the direction of diameter of the housing at the time of releasing hydraulic fluid through the inside of the housing, thereby making it possible to avoid the generation of strange noise by the vibration of ball valve. It is desirable to form the surface of valve body or the valve body side surface of the finger-like portions so that it has a surface roughness within a specific range in order to make the noise prevention effect more perfect.

Relief valve of hydraulic devices

A piston defines in a cylinder housing a pressure chamber connected to a brake pipe and a fluid supply chamber connected to an oil reservoir. The piston has a recess facing the pressure chamber at one end thereof. A valve member is provided in the recess for making or breaking fluid communication between the pressure chamber and the oil reservoir through the supply chamber. A compression spring is disposed in the recess for urging the valve member into its closed position. A spring retainer is fitted about the end of the piston for holding the spring in the recess. A supporting member is provided in the housing on the opposite side of the pressure chamber from the piston. The valve member is supported by a connecting rod extending axially movably through the spring retainer and the supporting member. A compression spring is connected between the spring retainer and the supporting member for urging the connecting rod in the direction which causes the valve member to open. The spring retainer is movable axially of the piston, while the supporting member is fixed to the housing.

A hydraulic pressure cylinder with an integrated reservoir which includes a cylinder body of strengthened resin, a reservoir tank of strengthened resin molded with the cylinder body as one body and having a wall portion and an opening formed in the wall portion of the reservoir tank and having a frame portion defined by the opening, and a window plate formed of resin material soluble in said strengthened resin and having a high transparency characteristic, the window plate including a flange which is welded to an inner surface of a wall portion of a reservoir tank and a projecting part which projects from the flange toward an outer surface of the wall portion of the reservoir tank along the frame portion.

Hydraulic pressure cylinder with integrated reservoir

A piston for a cylinder device which is formed of fiber glass strengthened resinous material and includes a concave portion, where a plug may remain, formed on an end thereof. The piston is engageable with a push rod and in particular an end surface of the push rod. The concave portion may be formed on approximately the center portion of the end concave surface of the piston and may be of circular configuration. Correspondingly, the concave portion may be formed on a flat surface of the end surface of the piston.

Piston for cylinder device

A master cylinder of resin material includes a cylinder having a receiving portion within which a piston is sealingly slidable, a cylindrical portion having a diameter which is larger than that of an outer periphery of the cylinder and coaxially rearwardly extending from the fore part of the receiving portion, and mounting flanges radially extending from a rearward end of the cylindrical portion. Each of the cylinder, the cylindrical portion and the mounting flanges are integrally formed.

A master cylinder reservoir includes a reservoir cap fixed in an open portion of the reservoir. The master cylinder reservoir comprises a cam portion formed on the periphery of the reservoir in the direction meeting at right angles with the axial center of the reservoir, a nail means formed on the reservoir cap and having tip end bended inside, a guide means formed on the upper end of the cam portion, and a gloove-hole formed between the cam means, and the stop means to thereby receive the tip end of the nail means therein, whereby the movement of the reservoir cap in the circumferential direction and the upper and lower directions will be prevented.

Master cylinder reservoir and cover fastening means

In a sealing or piston cup for maintaining lubricating oil on a sealing surface, the sealing surface thereof is formed with a circumferentially extending angular recess or groove which functions to retain lubricating oil. The sealing cup with the recess can ensure a smooth and stable operation of the device.

Sealing cup for hydraulic piston-cylinder device

A sealing cup to be used for a hydraulic piston-cylinder device the cup having an outer lip with a leading edge adapted to slide along a wall when fitted in the device. The angle .alpha. of the leading edge with respect to the cylinder axis is made smaller than the angle of a portion other than the leading edge with respect thereto, and is made as 1.degree..ltoreq..alpha..ltoreq.15.degree. in the free condition of the cup. When the sealing cup is installed to be slid in the cylinder, a wedge-shaped clearance is formed between the leading edge and the cylinder wall due to provision of the angle .alpha., thereby admitting the fluid therein to decrease the slide resistance of the sealing cup.

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Anjo, Japan

Kaoru Nakamura