Patent ID: 7987871
Filing Date: 2011-08-02
Classification: F16K,F25B,Y10T

Abstract:
1. A switching valve for switching a valve chamber which communicates with an introduction fluid passage and a discharge fluid passage, said switching valve comprising: a) a valve chamber disposing a first valve seat and a second valve seat opposing said first valve seat; b) a first fluid passage communicating with a first valve orifice defined on the periphery of said first valve seat of said valve chamber for introducing an operating fluid; c) a second fluid passage communicating with said valve chamber for discharging or introducing said operating fluid; d) a third fluid passage communicating with a second valve orifice defined on the periphery of said second valve seat of said valve chamber for discharging said operating fluid from said valve chamber; e) a valve body being disposed in said valve chamber and interchangeably lifting from and resting on said first valve seat and said second valve seat; f) a rod portion being connected with said valve body; g) a bearing portion with a guide bore guiding displacement of said rod portion; h) a recessed retainer recessed in the circumference of said guide bore on the upper surface of the bearing portion, wherein the recessed retainer has a cavity circumferential wall and a cavity bottom surface; i) a seal means disposed in the recessed retainer, wherein a side surface of the seal means contacts said cavity bottom surface of the recessed retainer and an inner circumferential surface of the seal means forms a light contact with an outer circumferential surface of the rod portion such that the seal means forms a seal between said valve chamber and said retainer, and wherein a separation is formed between an outer surface of the seal means and the cavity circumferential wall; j) an auxiliary passage communicating with said retainer and said first fluid passage; and k) a solenoid portion actuating a solenoid rod which is connected with said rod portion, wherein a first pressure-receiving area, which is defined by a surface inside the periphery of contact of said first valve seat and said valve body and receives pressure of the operating fluid from the first fluid passage, is approximately the same as a third pressure-receiving area of said rod portion which receives pressure of the operating fluid from said first fluid passage within said retainer.