| 摘要 |
PURPOSE:To move a switching valve piece upon the initial stage of operation thereof so that is enters into a downward stroke even if it is located at any position and smooth the operation thereof by a method wherein the switching valve piece is made so as to have a configuration having an area difference between the upper and lower surfaces thereof. CONSTITUTION:Primary fluid, entered from a primary fluid supplying port 2, passes through a path 15 and arrives at the path 16 when the valve piece is located at the initial position thereof which is shown in the diagram. Then the switching valve piece 8 obtains a downward force by the pressure of the primary fluid communicating with a stepped part 8' formed by the phiC and phiB parts of the valve piece 8 and begins to move downwardly. In another diagram showing the intermediate position of the valve piece, the pressure of the primary fluid is acting on the (phiC-phiA) part and the (phiC-phiD) part of the switching valve piece 8 which began to move, however, the upper surface or the (phiC-phiA) part 81 has the area larger than the same of the lower surface or the (phiC-phiD) part 82, therefore, the switching valve piece 8 moves downward further. Thus, the operation of the valve piece may be made smooth by a method wherein the switching valve piece 8 is moved downwardly at the beginning of the operation thereof. |
