Reversing valve and household water purifier including same technical field

A reversing valve, comprising:

• a valve body, having a cylindrical or approximately cylindrical valve element disposed therein, wherein the valve element has a first end surface and a second end surface opposite to the first end surface;
• a piston seat, disposed on the first end surface side of the valve element and having at least a portion in contact with the valve body, wherein an axially movable piston is disposed in the piston seat;
• a diaphragm end cover, disposed on one side of the piston seat opposite to the valve body;
• a piston diaphragm, fixed to the diaphragm end cover and disposed between the diaphragm end cover and the piston seat, and at least a portion of the piston diaphragm is also disposed between the piston and the piston seat, the piston and the piston seat being spaced apart by the diaphragm during axial movement of the piston so that the piston has no direct radial contact with the piston seat;
• and
• a spring housing, disposed on the second end surface side of the valve element and having at least a portion in contact with the valve body, wherein a compression spring is disposed in the spring housing and the compression spring is disposed to be in contact with the second end surface of the valve element,
• wherein the piston diaphragm, the piston, the valve element, and the compression spring are disposed to be coaxial and movable axially;
• and wherein
• the piston diaphragm and the diaphragm end cover jointly form a first cavity in the diaphragm end cover, and the first cavity communicates with the exterior of the reversing valve through a first channel;
• a first seal ring, a second seal ring, a third seal ring, and a fourth seal ring are sequentially disposed at different predetermined positions within the valve body in a direction from the first end surface to the second end surface;
• the valve body makes contact with the valve element by the first to fourth seal rings, and the valve body, the valve element, the first seal ring, and the second seal ring jointly form a second cavity in the valve body;
• the second cavity communicates with the exterior of the reversing valve through a second channel;
• the valve body, the valve element, the second seal ring, and the third seal ring jointly form a third cavity in the valve body;
• the third cavity communicates with the exterior of the reversing valve through a third channel;
• the valve body, the valve element, the third seal ring, and the fourth seal ring jointly form a fourth cavity in the valve body, and the fourth cavity communicates with the exterior of the reversing valve through a fourth channel;
• a first depressed portion and a second depressed portion are sequentially disposed on a cylindrical surface of the valve element in the direction from the first end surface to the second end surface, wherein the second depressed portion is spaced apart from the first depressed portion by a predetermined distance in an axial direction of the cylindrical surface of the valve element when the valve element moves to a position where the first depressed portion spatially overlapping with the second seal ring, the second cavity communicates with the third cavity;
• and when the valve element moves to a position where the second depressed portion spatially overlapping with the third seal ring, the third cavity communicates with the fourth cavity.