Seal structure in spool type switching valve and the spool type switching valve

摘要

(Task) A seal structure between the spool and the spool hole in a spool type switching valve capable of realizing a smoother operation of the spool and extending the life of the packing, and a spool type switching valve having such a seal structure. to provide. (Solution means) In the state where the outer diameter Dp of the packing 50 having a pair of seal portions 53 and 54 on both side ends of the outer circumferential surface is attached to the land portion 26 of the spool 20, the cylinder hole The first and second spaces (S1, S2) are formed to be smaller than the diameter (D0) of the sliding surface 75 of (7), and the outer circumference of the land portion is opposed to the sliding surface, and is divided by the land portion. ), when the compressed fluid is supplied from the air supply passage 8 to the first space, the side end of the packing on the first space side extends in the radial direction Y due to elastic deformation due to the fluid pressure, and the first The sealing portion was configured to confine the void δ formed between the sliding surface and the sliding surface or to contact the sliding surface.