| 摘要 |
<p>PROBLEM TO BE SOLVED: To improve the rigidity of a sleeve, to ensure the operation of high quality while reducing an amount of oil leakage by minimizing a clearance between the sleeve and a rotary spools, and to improve the characteristics of a valve by positioning upper ends of vertical grooves adjacent to each other in zigzag. SOLUTION: Upper end positions of adjacent vertical grooves are arranged in zigzag in such manner that a vertical groove 31A is located on an upper position, and lower end positions thereof are arranged in zigzag in such manner that a vertical groove 32A is located on a lower position. By arranging the upper ends of the vertical grooves 31A, 32A formed on an inner surface of a sleeve 24 in zigzag, and arranging the lower end positions in zigzag, the rigidity of the sleeve 24 is increased, and a pressure receiving area of the sleeve 24 can be reduced. Accordingly the generation of distortion of the sleeve 24 caused by the hydraulic oil acting on the inner surface of the sleeve 24 can be inhibited, and the sleeve 24 and a rotary spool 23 can be properly operated by reducing an amount of oil leakage by minimizing the clearance between the sleeve 24 and the rotary spool 23.</p> |
