| 摘要 |
PURPOSE:To provide a means to detect oil leak failure by dividablly joining a housing at the middle a housing containing a pair of pressure receiving pistons and connecting the inside and outside of such joined part with a small hole to allow the flow of working oil from the inside only through said hole. CONSTITUTION:A proportional valve consists of a pressure receiving piston 9, a valve 23 and a pressure adjusting spring 13, its housing 5 being divided to a left part 51 and a right part 52 at its middle, one-way sealing member 29 being attached to a seal housing 34 on such divided surface, and a small hole 28 being connected to the outside. When a seal member 301 attached to the outer circumference of either one of the pressure receiving piston 91 or a seal member 311 attached to the outer circumference of a valve transfer piston 111 is worn or damaged to allow flow of working oil from an input oul pressure chamber 181 to a larger diameter hole 81, such oil flows outside through the one-way seal member 29 and the small hole 28 thereby enabling the detection of failure through the abnormal change of oil level in the oil reservoir of the master cylinder M. |
