ELECTRONIC EXPANSION VALVE

Abstract

The present application provides an electronic expansion valve, comprising: a valve body, the valve body having an accommodating cavity and a valve port, and the valve port being in communication with the accommodating cavity; a guide sleeve, which is disposed in the accommodating cavity; and a valve head, which is movably disposed in the guide sleeve, the valve head being used for blocking or opening the valve port, and the valve being being internally provided with a balance channel so as to, by means of the balance channel, enable the two ends of the valve head to communicate with one another. The valve head is provided with a first end and a second end that are disposed opposite one another, the first end is used for blocking the valve port, a cold medium and the first end have a first stress area S1, and the cold medium and the second end have a second stress area S2, where -1.3mm2=S1-S2=1.3mm2. By means of the technical solution provided by the present application, the problem in the existing technology of poor reliability of the operation of an electronic expansion valve can be solved.

Specification

What is claimed is
1. An electronic expansion valve, comprising:
a valve body (10), wherein the valve body (10) has an accommodating cavity (101) and a valve
port (102), and the valve port (102) communicates with the accommodating cavity (101);
a guide sleeve (20), which is disposed in the accommodating cavity (101);
a valve head (30), which is movably disposed in the guide sleeve (20), the valve head (30) is
configured for blocking or opening the valve port (102), and a balance channel is disposed in
the valve head (30) so as to enable two ends of the valve head (30) to be communicated;
wherein the valve head (30) has a first end (301) and a second end (302) which are oppositely
disposed, the first end (301) is configured for blocking the valve port (102), a refrigerant
medium and the first end (301) have a first stress area S1, the refrigerant medium and the
second end (302) have a second stress area S2, and -1.3 mm2≤S1-S2≤1.3 mm2
.
2. The electronic expansion valve as claimed in claim 1, wherein the valve head (30) has a first
communicating hole (31), a second communicating hole (32) and a third communicating hole (33)
sequentially communicated along a direction from the first end (301) to the second end (302), an
aperture of the first communicating hole (31) and an aperture of the third communicating hole (33)
are greater than an aperture of the second communicating hole (32), the electronic expansion valve
further comprises:
a screw (40), the screw (40) is movably disposed in the accommodating cavity (101), and an
end of the screw (40) sequentially passes through the third communicating hole (33) and the
second communicating hole (32) and extends into the first communicating hole (31);
a valve sleeve (50), which is located in the first communicating hole (31), and is fixedly
connected with an end part of the screw (40), a step face formed by the first communicating
hole (31) and the second communicating hole (32) carries out an axial limit on the valve sleeve
(50), a first gap is formed between the screw (40) and the second communicating hole (32), a
second gap is formed between the screw (40) and the valve sleeve (50), the first gap and the
second gap are communicated to form the balance channel, and the first communicating hole
(31) and the third communicating hole (33) are communicated through the balance channel;
wherein an end face area of the first end (301) is S11, an area of the step face formed by the
first communicating hole (31) and the second communicating hole (32) is S12, and S1 is a sum
of S11 and S12; an end face area of the second end (302) is S21, an area of a step face formed
by the third communicating hole (33) and the second communicating hole (32) is S22, and S2 is
a sum of S21 and S22.
3. The electronic expansion valve as claimed in claim 2, wherein an outer diameter of a part,
corresponding to the first communicating hole (31), of the valve head (30) is D1, an outer diameter
of the part, corresponding to the third communicating hole (33), of the valve head (30) is D2, and
D1=D2; and the aperture of the first communicating hole (31) is d1, the aperture of the third
communicating hole (33) is d2, and -1 mm≤d1-d2≤1 mm.
4. The electronic expansion valve as claimed in claim 3, wherein a chamfer R1 is disposed on a
peripheral surface of an end part of the first end (301), and R0.04 mm≤R1≤R0.8 mm.
5. The electronic expansion valve as claimed in claim 2, wherein an outer diameter of the first end
(301) is greater than an outer diameter of the second end (302), a difference value between the
outer diameter of the first end (301) and the outer diameter of the second end (302) is smaller than
or equal to 4 mm, and a difference value between the aperture of the first communicating hole (31)
and the aperture of the third communicating hole (33) is -1 mm to 1 mm.
6. The electronic expansion valve as claimed in claim 5, wherein a chamfer R2 is disposed on a
peripheral surface of an end part of the first end (301), and R0.04 mm≤R2≤R3 mm.
7. The electronic expansion valve as claimed in claim 5, wherein a part, corresponding to the first
communicating hole (31), of the valve head (30) has a first section (311), a transition section (312)
and a second section (313) sequentially connected along the direction from the first end (301) to the
second end (302), an outer diameter of the second section (313) is smaller than an outer diameter
of the first section (311), and an outer diameter of the transition section (312) gradually decreases
along a direction from the first section (311) to the second section (313).
8. The electronic expansion valve as claimed in claim 2, wherein the first communicating hole (31)
comprises a first through hole (3101) and a second through hole (3102) disposed in a step, an
aperture of the first through hole (3101) is greater than an aperture of the second through hole
(3102), the first through hole (3101) is disposed close to the valve port (102), a stepped face is
disposed between the first through hole (3101) and the second through hole (3102), an area of the
stepped face is S10, and S1 is a sum of S10, S11 and S12; and/or,
the third communicating hole (33) comprises a third through hole (331) and a fourth through
hole (332) sequentially communicated, the fourth through hole (332) is a conical hole, an
aperture of the fourth through hole (332) gradually increases towards a direction away from the
valve port (102), a stress area of the fourth through hole (332) is S20, and S2 is a sum of S20,
S21 and S22.
9. The electronic expansion valve as claimed in claim 1, wherein a chamfer R3 is disposed on a
peripheral surface of an end part of the second end (302).
10. The electronic expansion valve as claimed in claim 1, wherein the valve head (30) has a first
communicating hole (31), a second communicating hole (32) and a third communicating hole (33)
sequentially communicated along a direction from the first end (301) to the second end (302), an
aperture of the first communicating hole (31) and an aperture of the third communicating hole (33)
are greater than an aperture of the second communicating hole (32); the electronic expansion valve
further comprises:
a screw (40), the screw (40) is disposed in the valve head (30) in a penetrating manner, the
screw (40) has a first rod section (41) and a second rod section (42) sequentially disposed
along an axial direction, a section structure (44) is disposed on a side wall of the screw (40), the
section structure (44) extends to a tail end of the second rod section (42) from a middle of the
first rod section (41), the balance channel is disposed between the section structure (44) and
the valve head (30);
a valve sleeve (50), which is located in the first communicating hole (31), the valve sleeve (50)
has a first connecting hole (51), the second rod section (42) is connected with the first
connecting hole (51), and a first gap is disposed between the section structure (44) and the first
connecting hole (51);
wherein a diameter of the first connecting hole (51) is D3, a maximum value of the first gap is
L1, and 0.5*D3>L1>0.1*D3.

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