Kabushiki Kaisha Riken

Honda Giken Kogyo Kabushiki Kaisha

Hiroshi Miida

Sumio Ono

Yoshiaki Wada

Ko Chiba

Yoshihito Ohya

Hisanori Okamoto

Motoaki Hayashi

Masashige Uematsu

A manufacturing method of a piston ring is developed, wherein the method provides a countermeasure for wear of butt ends of the ion plating film coated piston ring and a countermeasure for breakage of the piston ring and the piston ring manufactured at a low cost. A thickness of the film () in the vicinity of butt ends () of a piston ring () is made greater than the thickness of the film () at other outer peripheral surface. Piston ring blanks () are rotated around their own axes toward an evaporation source () and a speed is lowered when the butt ends () face the evaporation source ().

Piston ring and method of manufacturing the same

The invention particularly relates to a solenoid valve used in a control fluid, and one end of a center pole on the side opposite from a plunger is covered with theend face of a housing, and a communication passage is formed in the housing to communicate a through hole of the center pole with an opening formed on the housing on the side of the plunger. The communication passage has an end face groove and at least one side face groove on the end face and the side face of the housing. A volume of the side face groove is larger than a variation in volume of a space between the plunger and the center pole due to the movement of the plunger, and it is 2.5 times or more of the variation in volume of the space between the plunger and the center pole due to the movement of the plunger. Thus, the control fluid of the plunger on the opposite side from the center pole is reduced to enter along the outer periphery of the plunger into the space between the plunger and the center pole, and impurities can be easily and reliably prevented from being accumulated between the center pole and the plunger.

Solenoid valve

The annular expander of a piston ring assembly with vertically extending notches each of which is formed on either side of a plurality of circumferentially spaced upstanding tabs projecting from the top and bottom edges of the expander. The tabs, which form the abutments for the inner peripheral edges of upper and lower annular side rails, the outer peripheral edges of which are in sliding contact with a cylinder wall, undergo elastic deformation made possible by the notches when the corresponding side rails are subjected to a strong force received from the cylinder wall owing to piston wobble during reciprocation. The elastic deformation of the tabs assures that the side rails will remain in contact with the cylinder wall at all times during the reciprocation of the piston.

Corrugated expander for piston ring assembly

Growing community of inventors

Niigata-ken, Japan

Hiroshi Miida