Jtekt Corporation

Toyoda Koki Kabushiki Kaisha

Masaya Segi

Masaru Suzuki

Mikio Suzuki

Kaori Fujita

Koichi Takanishi

Yoshinori Kaneda

Yutaka Mori

Tomonari Yamakawa

Kenji Takahashi

Satoshi Suto

Nobuaki Nonoyama

In a solenoid valve, multiple flow-blocking portions are formed in a passage between a supply port () and an output port () and a passage between the output port () and a drain port (). The flow-blocking portions, having an overlap length that corresponds to the movement amount of a spool (), are formed by the outer peripheral faces of lands () and the inner peripheral face of a spool case ().

Solenoid valve

A solenoid valve comprises a solenoid portionand a valve portion. The solenoid portionis constructed by a stator core, an electromagnetic coiland a plunger. The valve portionis constructed by a valve sleeveand a spoolaxially forming plural lands-in series. The plungeris axially moved by electromagnetic attraction and drives the spool. There are formed the same pressurized areas at the plungerand the land of the spoolclosest to the plunger. Therefore, the volume in an intermediate space B between the plungerand the spoolis constant and contaminants in the oil are not sucked into the intermediate space B.

In a solenoid valve, an annular oil grooveis formed at a portion corresponding to a spring chamberon the external surface of a sleeve, a drain passageis formed to make an upper part of the annular oil groovecommunicate with the outside of an insertion bore, and a throttle holeis provided at a lower part of the annular oil groovefor making the annular oil groovecommunicate with the spring chamber. Since the annular oil groovecommunicates with the outside of the insertion boreat its upper part through the drain passage, it can be realized to store the operating oil to the height of the upper part of the annular oil groove, so that the operating oil can be reserved in the spring chamberwhich communicates with the annular oil groove through the throttle hole. Further, the operating oil is supplied from a feedback portnext to the spring chamberthrough a clearance between the spool valveand a valve hole. Thus, the solenoid valveis able to secure the damping effect of the working oil on the spool valveand a plungerand to suppress the self oscillation even while being operated in the atmosphere for a long time.

Disclosed is a solenoid-operated valve which hardly brings a plunger into a lock and is capable of improving its responsivety. In the solenoid-operated valve, the plunger slidably guided in an inner bore formed in a yoke and a core aligned axially is moved by energizing an electromagnetic coil, and a spool in a valve section is moved through a rod portion which protrudes from an end of the plunger to pass through a center hole of the core. An electromagnetic section fluid chamber defined by a forward end surface of the plunger and the inner bore of the core communicates with an intermediate fluid chamber defined between the core and a valve sleeve, through a clearance between the center hole and rod portion. The spool is provided at one end thereof with a land portion whose end surface defines a part of the intermediate fluid chamber. The diameter of the land portion is chosen to be the same as the diameter of the plunger, so that the sum in volume of the electromagnetic section fluid chamber and the intermediate fluid chamber can be kept invariable regardless of movement of the plunger. A supply/drain passage is further provided to permit the oil around the solenoid-operated valve to be charged into the rear end fluid chamber or discharged therefrom upon movement of the plunger.

Solenoid-operated valve

An electromagnetic drive device for lineally reciprocatilvely moving an operating member like a spool of a spool valve is reduced in the manufacturing cost without being degraded in its operational performance. In the electromagnetic drive device, a stator body is excited by an electromagnetic coil to axially move a plunger guided in an inner bore of the stator body, against the resilient force of a spring. The stator body is constituted by arranging a plurality of core portion annular plate elements made of a magnetic material, a plurality of yoke portion annular plate elements made of a magnetic material and a plurality of non-magnetic portion annular plate elements made of a non-magnetic material and placed between the core portion annular plate elements and the yoke portion annular plate elements and by piling up and bodily joining these annular plate elements in axial alignment with one another. Each of the annular plate elements is provided with plural embossed portions each of which is half-blanked to be prominent at one surface side and hollow at the other surface side. The embossed portions formed on each annular plate element are fit at the prominent surface sides thereof respectively in the hollow surface sides of the embossed portions formed on another annular plate element, so that all the annular plate elements can be bodily joined in axial alignment with one another.

Electromagnetic drive device

A pressure switch includes a switch housing which has an accommodation bore extending inward from one end of the switch housing, and a slide bore extending between the accommodation bore and the other end of the switch housing. A piston is slidably disposed within the slide bore and is adapted to receive a pressure. A terminal serving as one electric contact is fixed to the accommodation bore via a holding ring made of an insulating material. A disk spring serving as the other electric contact is disposed between the piston and the terminal. The disk spring deforms due to a pressing force of the piston and comes in contact with the terminal. The pressure switch further comprises an annular elastic ring placed on the outer end of the holding ring. An end portion of the switch housing is deformed inward so as to elastically deform the elastic ring, thereby sealing the opening portion of the accommodation bore. The switch housing has a cylindrical portion which has a cylindrical outer shape and into which the holding ring is press-fit, a threaded portion for attachment of the switch housing, and a polygonal tightening portion which is formed between the cylindrical portion and the threaded portion and is used to tighten the switch housing.

Growing community of inventors

Okazaki, Japan

Masaya Segi