Patent ID: 7146998
Filing Date: 2006-12-12
Classification: F15B,G05D,Y10T

Abstract:
1. A hydraulic valve comprising: a valve body which has an internally cylindrical spool-receiving room and an oil groove provided orthogonally to an axis of said spool-receiving room, and a spool, which is inserted in said spool-receiving room; wherein: said spool is shifted axially in correspondence to an actuation pressure being supplied into said oil groove; said oil groove has a draft which facilitates the removal of the die assembly; a stepped down groove is provided around a peripheral surface of said spool that faces said oil groove, so that a hydraulic pressure supplied into said oil groove is made to act on said spool at said stepped down groove so as to eliminate possibility of an unbalanced load acting on said spool in a direction perpendicular to an axis of said spool; and both axial ends of said stepped down groove are located axially outside of both axial ends of said oil groove at least while said hydraulic valve is in pressure-adjusting condition.