| 摘要 |
PURPOSE:To eliminate leakage of liquid and contrive long life of the valve by a method wherein the sliding surface of the fixed valve seat of the valve is arranged concentrically with a flow path switching hole, a wedge-shaped groove for supplying lubricating oil and a groove for retrieving waste liquid which has finished lubrication. CONSTITUTION:A surface 31, contacting with the valve 22, is arranged with a plurality of wedge-shaped grooves 32 at the innermost side thereof and three sets of holes 36, 37, 38, switching the flow path of the liquid of specimen, are provided at the outside of these grooves 32 while these holes are communicated with the holes 39, 40, 41 bored on the outer peripheral surface 34. The effect of the lubrication of ground surfaces becomes several times by providing the valve 22 with the annular grooves 49, 50 coinciding with the wedge-shaped grooves 32 of the valve seat 17. The liquid, forced out of the ground part by the lubricating motions of the valve 22 effected in every pivots, flows down into a whole circumferential groove 42 and is discharged through a tube 10. |
