Reversing valve and household water purifier including same technical field

1. 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.

2. The reversing valve according to claim 1 , wherein

the valve element is hollow and has a duct disposed therein and connects the first and second end surfaces thereof.

3. The reversing valve according to claim 2 , wherein

each of the first depressed portion and the second depressed portion consists of a group of recesses distributed around an axis of the valve element on the surface of the valve element and spaced apart from one another, and none of the recesses communicates with the duct of the valve element.

4. The reversing valve according to claim 2 , wherein

a portion of the piston extends into the duct of the valve element.

5. The reversing valve according to claim 2 , wherein

the reversing valve further comprises a piston-side cavity located between the piston and the piston seat, the piston-side cavity is formed jointly by the piston diaphragm, the valve element, and the piston seat, and the piston-side cavity communicates with the duct of the valve element, and when the valve element moves toward the diaphragm end cover, a volume of the piston-side cavity increases, and when the valve element moves toward the spring housing, the volume of the piston-side cavity decreases.

6. The reversing valve according to claim 5 , wherein

the reversing valve further comprises a spring-side cavity located between the spring housing and the valve body, the spring-side cavity is formed jointly by the valve body, the valve element, and the spring housing, and the spring-side cavity communicates with the duct of the valve element, and when the valve element moves toward the diaphragm end cover, a volume of the spring-side cavity increases, and when the valve element moves toward the spring housing, the volume of the spring-side cavity decreases.

7. The reversing valve according to claim 6 , wherein

when the valve element moves in a reciprocating manner in the valve body, the increased or decreased volume values of the piston-side cavity and the spring-side cavity are the same.

8. The reversing valve according to claim 6 , wherein

the reversing valve further comprises a ventilation channel located at the piston side and communicates with the exterior of the reversing valve, and the ventilation channel communicates with the piston-side cavity through a gap between the valve element and the piston seat.

9. The reversing valve according to claim 8 , wherein

the ventilation channel is bent.

10. The reversing valve according to claim 1 , wherein

the diaphragm end cover, the piston seat, the valve body, and the spring housing are fixed together by bolt and nut fasteners, threaded connections, or welding.

11. The reversing valve according to claim 1 , wherein

the piston seat, the valve body, and the spring housing are integrally formed, and the diaphragm end cover and the integrally formed portion are fixed together by bolt and nut fasteners, threaded connections, or welding.

12. The reversing valve according to claim 1 , wherein

the valve body and the piston seat are integrally formed, and the diaphragm end cover, the integrally formed portion, and the spring housing are fixed together by bolt and nut fasteners, threaded connections, or welding.

13. The reversing valve according to claim 1 , wherein

the valve body and the spring housing are integrally formed, and the diaphragm end cover, the piston seat, and the integrally formed portion are fixed together by bolt and nut fasteners, threaded connections, or welding.

14. The reversing valve according to claim 1 , wherein

when a pressure acting on the piston diaphragm through the first channel decreases, the valve element, being pushed by the compression spring, moves toward the piston side till it reaches a first predetermined position, and from this point till the valve element moves to a second predetermined position where the piston is stopped by the diaphragm end cover, the second depressed portion spatially overlaps the third seal ring so that the third cavity communicates with the fourth cavity, and the first depressed portion is located between the first seal ring and the second seal ring, and the first depressed portion does not spatially overlap with either of the first or second seal rings.

15. The reversing valve according to claim 1 , wherein

when a pressure acting on the piston diaphragm through the first channel increases so that the valve element moves toward the compression spring side and the amount of movement of the valve element is within a predetermined range, the first depressed portion is located between the first seal ring and the second seal ring, and the first depressed portion does not spatially overlap with either of the first or second seal rings, and the second depressed portion is located between the third seal ring and the fourth seal ring, and the second depressed portion does not spatially overlap with either of the third or fourth seal rings.

16. The reversing valve according to claim 15 , wherein

when the pressure acting on the piston diaphragm through the first channel continues increasing, the valve element continues to move toward the compression spring side till it reaches a third predetermined position, and from this point till the valve element continues to move to a fourth predetermined position where the piston is stopped by the piston seat, the first depressed portion spatially overlaps the second seal ring so that the second cavity communicates with the third cavity, and the second depressed portion is located between the third seal ring and the fourth seal ring, and the second depressed portion does not spatially overlap either of the third or fourth seal rings.

17. The reversing valve according to claim 1 , wherein

the first depressed portion is designed to spatially overlap the second seal ring only, the second depressed portion is designed to spatially overlap the third seal ring only, and the spatial overlap between the first depressed portion and the second seal ring does not coexist with the spatial overlap between the second depressed portion and the third seal ring.

18. A household water purifier, comprising:

a reverse osmosis membrane filter element, comprising a water inlet, a pure water outlet, and a non-pure water outlet, wherein the water inlet is used for receiving water to be treated;

a first one-way valve, having a water inlet communicating with the pure water outlet of the reverse osmosis membrane filter element through a waterway;

a second one-way valve, having a water inlet communicating with a water outlet of the first one-way valve through a waterway and having a water outlet communicating with a water inlet of a tap through a waterway;

a water storage tank, comprising a first cavity and a second cavity isolated and formed by a waterproof film, wherein total capacities of the two cavities are fixed, and the capacity of the first cavity decreases as the capacity of the second cavity increases or the capacity of the first cavity increases as the capacity of the second cavity decreases; the first cavity is used for accommodating pure water from the pure water outlet of the reverse osmosis membrane filter element and communicates with the water outlet of the first one-way valve and the water inlet of the second one-way valve through a waterway, and the second cavity is used for accommodating non-pure water from the non-pure water outlet of the reverse osmosis membrane filter element;

a switching device, used for connecting or disconnecting a waterway to the water inlet of the reverse osmosis membrane filter element according to a pressure change in the first cavity of the water storage tank; and

the reversing valve according to claim 14 , 15 , 16 , or 17 , wherein the first channel of the reversing valve communicates with the water inlet of the tap through a waterway, the fourth channel of the reversing valve communicates with the non-pure water outlet of the reverse osmosis membrane filter element through a waterway, the second channel of the reversing valve communicates with a drainage path through a waterway, the third channel of the reversing valve communicates with the second cavity of the water storage tank through a waterway, the reversing valve is used for connecting the fourth channel to the third channel and meanwhile disconnecting the second channel from the third channel according to a change in water pressure acting on the piston through the first channel, or disconnecting the fourth channel from the third channel and meanwhile connecting the second channel to the third channel according to a change in water pressure acting on the piston through the first channel.

19. The household water purifier according to claim 18 , wherein when the pressure of the first cavity of the water storage tank decreases to a first threshold, the switching device connects the waterway to the water inlet of the reverse osmosis membrane filter element, and when the pressure of the first cavity of the water storage tank increases to a second threshold, the switching device disconnects the waterway to the water inlet of the reverse osmosis membrane filter element, and the first threshold is less than the second threshold.

20. The household water purifier according to claim 18 , wherein when the water pressure acting on the piston through the first channel decreases to a third threshold, the reversing valve connects the fourth channel to the third channel, and meanwhile disconnects the second channel from the third channel, and when the water pressure acting on the piston through the first channel increases to a fourth threshold, the reversing valve disconnects the fourth channel from the third channel and meanwhile connects the second channel to the third channel, and the third threshold is less than the fourth threshold.