Patent ID: 6810911
Filing Date: 2004-11-02
Classification: F16K,F25B,Y10T

Abstract:
A four-way switching valve for switching between a first state in which a fluid introduced into a first port is guided to a second port to allow the same to flow out therefrom and the fluid introduced into a third port is guided to a fourth port to allow the same to flow out therefrom, and a second state in which the fluid introduced into the first port is guided to the third port to allow the same to flow out therefrom and the fluid introduced into the second port is guided to the fourth port to allow the same to flow out therefrom,the four-way switching valve comprising: a first three-way switching valve for carrying out a switching operation to cause the second port to communicate with the first port or the fourth port; a second three-way switching valve for carrying out a switching operation in unison with the first three-way switching valve to cause the third port to communicate with the fourth port or the first port; and a piston for simultaneously actuating a valve element of the first three-way switching valve and a valve element of the second three-way switching valve, the first three-way switching valve, the second three-way switching valve, and the piston being coaxially arranged within a hollow cylindrical body, wherein the first three-way switching valve and the second three-way switching valve each comprises the valve element axially slidably arranged on a driving rod axially arranged, for opening and closing valve holes formed at openings of passages which are arranged on axially both sides of the valve element and communicated with the first port and the fourth port, guides each fixed to the driving rod and axially protruding outward from axially opposite seating surfaces of the valve element via which the valve element is seated, for being inserted into the valve hole to close the valve hole before the valve element is seated, and at the same time for limiting an axially slidable range of the valve element, and a spring for urging the valve elements in such a direction that the valve element is brought into abutment with an axially outwardly arranged one of the guides.