Pinch valve

A pinch valve comprising a body containing an elastic tube body which constitutes a flow passage for fluid;

• a cylinder body joined to the upper portion of the body at the lower end thereof and having a first cylinder portion in the upper portion of the interior thereof and a second cylinder portion with a diameter larger than that of the first cylinder portion in the lower portion of the interior thereof;
• a first piston sliding up and down on the inner peripheral surface of the first cylinder portion;
• and a second piston sliding up and down on the inner peripheral surface of the second cylinder portion;
• wherein the first piston is installed with a first interlocking rod suspending from the center of the lower surface thereof, penetrating the second piston and having a first pressing piece at the lower end of the first interlocking rod, the second piston is installed with second interlocking rods suspending from both ends of the lower surface thereof, penetrating the first pressing piece and having a second pressing piece at the lower ends of the second interlocking rods, the first and second pressing pieces are arranged to press the elastic tube body from the upper and lower sides, a spring elastic body urging the first pressing piece is disposed between the second piston and the first pressing piece, and an opening portion communicating with a space portion enclosed by the lower end surface of the first piston, the upper end surface of the second piston and the inner peripheral surface of the cylinder body is provided on the cylinder body.