| 摘要 |
<p>PROBLEM TO BE SOLVED: To secure specified lowest pressure in a pressure chamber regardless of external influence by providing a pipe joint with a pressure relief valve, whereby the pipe joint is open at pressure above the lowest pressure applied from the inside or outside of the pressure chamber and closed at the pressure below that. SOLUTION: A tubular elastomer 4 is placed through a vertical hole 8, 9 on a cylindrical body 3 with pre-load to inhibit flow connection of vertical holes 8, 9 until specified lowest pressure is generated. When pressure from the vertical hole 8, 9 is increased to a specified lowest pressure or more, the tubular elastomer 4 is separated in the radial direction from the cylindrical body 3 to make flow connection between the vertical holes 8, 9 through a connecting space 10. When the air with a specified lowest pressure or more to be secured in the pressure chamber is introduced into the vertical hole 9 from the outside, a passage to the inside of the pressure chamber is opened through the holes 6, 8. When pressure at the lowest pressure or more exists in the pressure chamber, the air flows out from the pressure chamber through the pipe joint 2. Accordingly, the pressure chamber is kept at specified pressure.</p> |
