| 摘要 |
PURPOSE:To securely obtain a pilot pressure required for the changeover of an air changeover valve. CONSTITUTION:A fitting portion 22 of a fixed length and contacted diameter is formed at a connection shaft 21 connecting both diaphragms, and thereon, an annular spool 23 whose width is narrower than the length of the fitting portion 22, is put airtightly and slidably. When the connection shaft 21 advances, for example, to the left and reaches the terminal of a stroke, the right end of the spool 23 faces a pilot air introduction opening 17 which opens a little, and pilot air flows into a pilot chamber 19 side and the right side of the spool 23 is made to rise up in pressure. When the pressure becomes more than fixed, the spool 23 is slided to the left by means of this pressure, and the pilot air introduction opening 17 is opened large instantly, and a lot of pilot air flows into the right side pilot chamber 19 side, and high pressure pilot pressure acts on a pilot pressure supply opening to which an air changeover valve is opposite. |
