Kabushiki Kaisha Fujikoshi

Ikuo Tochizawa

Kazuo Araki

An AC or DC solenoid for operating a hydraulic or air valve, or another machine comprises a means provided at one end of an armature for reducing the effective cross-sectional area of a magnetic path extending through the armature and a yoke when the armature and a stationary core have a distance therebetween which is smaller than a predetermined fraction of the full stroke of movement of the armature. The solenoid is further provided between the armature and the stationary core with a means permitting them to be brought into axially overlapping relation to form a section of leakage flux therebetween. According to another aspect of the invention, there is provided novel means for securing a solenoid of the armature in tube type to a valve body. The improved solenoid has a small size, a long life, and superior performance without causing any excessive attraction over a given small stroke and generating any large noise.

Solenoid

An AC solenoid apparatus of the armature-in-tube type for operating valves such as hydraulic/air valves, or other machines. The apparatus comprises a solenoid having a sealingly closed part including a pressure proof tube preferably made from a thin nonmagnetic material, and an exciting assembly having a coil encompassing the closed part and a yoke having a generally rectangular cross section. A slotted annular magnetic ring made from a magnetic material is inserted between the pressure proof tube and at least one part of the yoke. The solenoid of this invention is small in size and of low cost, and yet is endowed with a high force and a capability of restraining heat by being generated from the solenoid.

Growing community of inventors

Takaoka, Japan

Ikuo Tochizawa