Keihin Corporation

Hidetoshi Watanabe

Shigeto Ryuen

Satoshi Noda

Hideki Furuta

Tohru Ino

Masamichi Kagawa

Masahiro Watanabe

A linear solenoid valve includes a solenoid having a coil wound around a coil bobbin, a fixed core, and a movable core for being attracted to the fixed core when the coil is energized, and a valve mechanism having a valve element for selectively bringing an inlet port and an outlet port into and out of fluid communication with each other responsive to a displacement of the movable core. The movable core has a nonmagnetic layer formed on an outer surface thereof and having a predetermined thickness.

Linear solenoid valve

A bottom of a housing has a protruding support extending a predetermined distance toward a movable core, and the movable core has an annular boss extending a predetermined distance toward the housing. The annular boss is disposed in an annular space defined between the bottom of the housing and the protruding support of the housing.

A normally open hydraulic control valve includes: a linear solenoid unit; a spool driven by an output force of the linear solenoid unit to move forward; a valve body in which the spool is fitted; and a return spring for biasing the spool in a retreating direction. The valve body includes: a reaction force oil chamber for introducing hydraulic pressure, which presses the spool in a direction against a biasing force of the return spring, from the output port; and a damper oil chamber which suppresses vibration of the spool. The damper oil chamber is adjacent to the reaction force oil chamber with the third land portion of the spool therebetween. A slide gap which leaks and supplies oil from the reaction force oil chamber to the damper oil chamber is provided between the third land portion and the valve body. Thus, it is possible to quickly supply the oil to the damper oil chamber at the early stage of the operation without restriction on the arrangement, and to prevent delay in operation of the damper oil chamber.

Normally open hydraulic control valve

A damper device for a hydraulic control valve includes: a valve body; a damper oil chamber to which one end surface of a spool is faced; an oil reservoir chamber which is adjacent to the damper oil chamber with a partition wall therebetween; and an orifice provided in the partition wall to allow an upper portion of the damper oil chamber to communicate with the oil reservoir chamber. The damper oil chamber and the oil reservoir chamber are disposed in the valve body. The oil reservoir chamber is constructed by closing an opening of a recessed portion formed on an undersurface of the valve body with a top surface of the support member for supporting the valve body. In order to work the orifice in the partition wall by drilling from the opening of the recessed portion, an axis of the orifice is disposed to pass through the opening of the recessed portion. Thus, it is possible to eliminate need for post-treatment after working the orifice, thereby reducing the cost.

Damper device for hydraulic control valve

In a liquid pressure control system including a spool-type control valve mounted between a liquid pressure source and an actuator in such a manner that an output liquid pressure from the liquid pressure source is controlled in accordance with a thrust exhibited by a linear solenoid, a manually operated valve is disposed in a valve housing of the control valve to have an operational axis parallel to an axis of the linear solenoid. The manually operated valve is capable of blocking the communication between the actuator and the control valve and bringing the liquid pressure source into communication with the actuator to bypass the control valve. Thus, the supply of a liquid pressure to the actuator can be secured in any abnormality of the control valve, while enabling a reduction in size of the system in an axial direction of the control valve.

Growing community of inventors

Shibata-gun, Japan

Hidetoshi Watanabe