| 摘要 |
PURPOSE:To make a deformation quantity of a valve spindle at the time of firing small, by a method wherein valve molded body is fired by constituting the title method so that an axial line of the valve spindle becomes almost a vertical directing and a valve spindle whose sectional area is larger becomes the lower part. CONSTITUTION:A valve molded body 3 is formed of a ceramic material, the top of a valve spindle 2 has the smallest diameter D1, the lower end of the valve spindle 2 of a connecting part with a valve head part 1 has the maximum diameter D2 of the valve spindle 2 and the diameter becomes gradually and continuously small extending from the D2 to the D1. Moreover, since the valve head part 1 possesses the bottom 1a meeting perpendicularly with the axial line of the valve spindle 2, when the valve molded body 3 is put on a floor surface 4 by coming into contact with the upper part of the floor surface 4, holding can be performed easily so that the same becomes a posture for firing. When the firing is completed, the valve molded body 3 becomes a ceramic valve body. Then an outer circumferential surface of the valve spindle 2 is cut so that the valve spindle 2 of a valve body becomes columnar having a target diameter D4 as shown by a chain line with two dots and also the rear of the valve head part is cut in accordance with this. With this construction, a quantity of material and a time of cutting process of the ceramic material can be reduced. |
