WO2015143844A1

WO2015143844A1 - Electronic expansion valve

Info

Publication number: WO2015143844A1
Application number: PCT/CN2014/086174
Authority: WO
Inventors: 詹才意; 舒小辉; 张金荣
Original assignee: 浙江三花股份有限公司
Priority date: 2014-03-25
Filing date: 2014-09-10
Publication date: 2015-10-01
Also published as: CN103940159A; CN103940159B

Abstract

An electronic expansion valve, comprising a drive component and a valve body component, the valve body component comprising a valve body (400) having a flow-path inlet (401) and a flow-path outlet (402), a valve core (800) being disposed within an inner cavity (500) of the valve body (400) and a valve core base (700) having a valve opening part (701); by means of inputting a pulse signal into the drive component, driving the axial movement of the valve core (800) relative to the valve opening part (701) to change the flow area of the valve opening part (701), adjusting the refrigerant flow rate into the electronic expansion valve; the valve core (800) comprises a main body section (801) and an adjustment section (802) facing towards the valve core base (700), the main body section (801) and the adjustment section (802) being connected by means of tapered transition section (803), the adjustment section (802) comprising at least one first arc segment (805) to adjust the refrigerant flow rate variation curve; the valve core base (700) comprises a straight section valve opening part (701) and a tapered opening section (702) extending from the valve opening part (701) in the direction of the valve core (800); the diameter of the valve opening part (701) is defined as Φ2, the diameter of the smallest end of the tapered transition section (803) is defined as Φ3, and the diameter of the large end is Φ5, satisfying the relationship Φ3< Φ2< Φ5; the present electronic expansion valve facilitates adjustment of an air conditioning system, reducing the number of adjustments and improving the stability of the system.

Description

Electronic expansion valve

Technical field

The present invention relates to the field of control valves, and more particularly to an electronic expansion valve for regulating the flow of a refrigerant. Background technique

[02] In various refrigeration/heating equipment such as air conditioners, refrigerators, and heat pump water heaters, an electronic expansion valve is usually used to regulate the flow rate of the fluid.

[03] The electronic expansion valve generally includes a motor (drive member) having a motor and a valve body member as an actuator, and the valve body member includes a valve body having a refrigerant flow path inlet and a flow path outlet, a spool placed in the body cavity of the valve body and a spool seat having a valve port portion, by inputting a pulse signal to a motor as a driving member, driving an axial movement of the spool relative to the valve port portion to change the passage valve The flow rate of the refrigerant in the mouth reaches the flow rate of the refrigerant regulating the outlet of the flow path to control the heat exchange balance in the air conditioner or the refrigerator. Therefore, the flow rate change curve in the electronic expansion valve is a key technical feature, which directly determines the working efficiency of the refrigeration system.

An electronic expansion valve designed to improve a refrigerant flow rate change curve is disclosed in Japanese Laid-Open Patent Publication No. 2002-122367, and FIG. 1 is a valve body of the electronic expansion valve 310. And valve plug seat structure diagram. The spool 314 includes a flow regulating section 314f, and a tapered section 314a is disposed between the flow regulating section 314f and the main section (not shown), and a tapered section 314b is further included at a lower end of the flow regulating section 314f. The spool seat 310 includes a tapered valve port 313a and opening portions 313b and 313c connected to the valve port 313a. Fig. 2 is a graph showing a flow rate change of the electronic expansion valve shown in Fig. 1, wherein the abscissa indicates a pulse ratio, and the ordinate indicates a flow ratio. In this technology, the electronic expansion valve has a sudden opening flow rate change curve, for example, the flow rate changes little before the P2' point, and the flow rate changes faster after the P2' point, so that the flow adjustment accuracy before the P2' point is relatively high. . Although the above technology can To some extent, the accuracy of the electronic expansion valve at a small opening is improved, but there is a sudden change in the entire flow rate curve, and the position of the P3 'point fluctuates greatly due to the manufacturing error, generally 40 to 60 The difference in pulse causes the position of the P2 'point to also have a difference of at least 40 pulses, which causes the flow rate before and after the P2 ' point to be unpredictable, resulting in a decrease in the adjustment accuracy of the entire flow rate change curve. At the same time, although the flow change before the P2' point is approximately linear, the flow variation between the P2' point and the Ρ point corresponds to (Q2' - Ql ' ) / (P2, Ρ ) = K, and Κ is approximately a constant value, but It is still difficult to know how to change the flow rate of a pulse. This will increase the number of expansion valve adjustments, affect the stability of the air conditioning system, and also cause a decrease in energy efficiency. The host manufacturer also has too much dependence on the accuracy of the fixed-point flow control, resulting in many unnecessary control waste. Therefore, how to continuously optimize and improve the flow rate curve of the electronic expansion valve according to the specific requirements of the refrigeration system is a problem that the technical field has to solve. Summary of the invention

[05] It is an object of the present invention to provide a new optimized electronic expansion valve flow rate profile and at the same time provide a spool and spool seat structure. An electronic expansion valve disclosed in the present invention includes a driving member and a valve body member, the valve body member including a valve body having a flow path inlet and a flow path outlet, and a valve core disposed in the inner cavity of the valve body And a spool seat having a valve port portion, wherein a pulse signal is input to the driving member to drive axial movement of the valve body relative to the valve port portion to change a flow area of the valve port portion, and the flow into the valve is adjusted a refrigerant flow rate of the electronic expansion valve, the valve core including a main body section and an adjustment section facing the valve core seat, the main body section and the adjustment section being connected by a tapered transition section, the adjustment section including for adjusting a first circular arc segment of the refrigerant flow rate change curve, the valve core seat including the valve port portion in a straight section and a tapered opening segment extending from the valve port portion toward the valve core, The diameter of the mouth portion is defined as Φ 2 , and the small end diameter of the heterocyclic transition section of the valve core is defined as Φ 3 and the large end diameter is defined as Φ 5 , and the relationship Φ 3< Φ 2< Φ 5 is satisfied.

[06] Further, for an electronic expansion valve as described above, in a possible implementation manner, The adjustment section of the spool further includes a second arc segment connected to the first arc segment, the first arc segment being tangent to the second arc segment, the curvature of the first arc segment The radius is greater than the radius of curvature of the second arc segment.

[07] Further, in a possible implementation manner, the adjusting section of the spool further includes a third arc segment connected to the second arc segment, the second arc segment and the The third arc segment is tangent, and the radius of curvature of the second arc segment is greater than the radius of curvature of the third arc segment.

[08] Further, in a possible implementation manner, the radius of curvature of the first circular arc segment is twice or more than the radius of curvature of the third circular arc segment.

[09] Preferably, in a possible implementation manner, when the spool is in a stroke range in which the regulating flow is performed, when the spool is axially opposite to the spool seat from the first position to the valve opening When moving to the second position, the number of pulses required to move the distance of the segment is defined as W, and the flow area of the valve port portion when the spool is in the first position is defined as S1, and the spool is in the In the second position, the flow area of the valve port portion is S2, and the relationship is satisfied: S2/S1 is equal to the power of K, which is a constant value, that is, ^w s2i si ^ K , and κ is a constant.

[10] Preferably, in a possible implementation manner, when the valve core adjusts the flow rate of the input pulse number greater than 100, when the valve core is opened from the first position relative to the valve core seat When the valve direction is axially moved to the second position, the number of pulses required to move the distance of the segment is defined as w, and the flow area of the valve port portion when the spool is in the first position is defined as S1, the valve When the core is in the second position, the flow area of the valve port portion is S2, and the relationship is satisfied: S2/S1 is equal to the power of K, which is approximately a constant value, that is, 3⁄4^«, and K is a constant.

[11] Preferably, in a possible implementation manner, in the range of the stroke in which the spool is adjusted to flow, the spool is moved in the valve opening direction with respect to the spool seat by any two axial directions. The equal distance interval is defined as: the flow area of the valve port portion is S3 at the start position of the first stage, the flow area of the valve port portion is S4 at the end position, and the valve port portion at the start position of the second stage The flow area is S5, and the flow area of the valve port portion at the end position is S6, which satisfies the relationship: S4/S3 is close to S6/S5 Like equal, §卩54 3 « 56 5.

[12] Preferably, in a possible implementation manner, in a range of the spool regulating flow rate of the input pulse number greater than 100, the spool is moved in the valve opening direction with respect to the spool seat. The interval in which the two axial distances are equal is defined as: the flow area of the valve port portion is S3 at the start position of the first stage, and the flow area of the valve port portion is S4 at the end position; The flow area of the valve port is S5, and the flow area of the valve port is S6 at the end position. The relationship is satisfied: S4/S3 is approximately equal to S6/S5, that is, 54 / S3 « 56 / 55.

[13] Meanwhile, the present invention also discloses an electronic expansion valve including a driving member and a valve body member, the valve body member including a valve body having a flow path inlet and a flow path outlet, and a valve body disposed on the valve body a spool in the inner chamber and a spool seat having a valve port portion, wherein a pulse signal is input to the driving member to drive axial movement of the spool relative to the valve port portion to change a flow of the valve port portion An area that regulates a flow of refrigerant into the electronic expansion valve, the spool including a body section and an adjustment section toward the spool seat, the body section being coupled to the adjustment section by a tapered transition section, The adjustment section includes at least one arc segment for adjusting a refrigerant flow rate change curve, the refrigerant flow rate change curve defines an abscissa as an input pulse signal number R value, and an ordinate is a refrigerant flow rate of the valve port portion Value, the flow rate change curve includes a valve port opening section and a flow rate adjustment section that implements an adjustment flow rate, and the flow rate adjustment section is a curve with increasing curvature.

[14] Further, in a possible implementation manner, the flow regulating section of the refrigerant flow rate change curve is a smooth curved line.

[15] Further, for the electronic expansion valve as described above, in a possible implementation manner, two points are arbitrarily set in the flow regulating section, and the coordinates defining the first point in the valve opening direction are (Rl, Wl ), the coordinates of the second point are (R2, W2), then the relationship is satisfied: (W2/W1) Open (R2-R1) The power is approximately constant, ie (" ² -«^7^1 ^, K is constant.

[16] Further, in a possible implementation manner, a curve in which the two sections of the abscissa distance are equal in the flow adjustment section is arbitrarily defined, and the starting point of the ordinate corresponding to the first section of the curve in the valve opening direction is defined as W3, the end point is W4, the ordinate of the second curve corresponds to W5, and the end point is W6, then the relationship is satisfied: W6/W5 is approximately equal to W4/W3, g卩W6/W5 W4/W3.

[17] According to the electronic expansion valve of the present invention, the head of the valve core is composed of a circular arc or a plurality of tangential arcs of different radii, which can ensure a small flow change in a small opening area, and a flow rate in a large opening area. The change is large, and there is no sudden change in the two changes, which is convenient for system adjustment. Through the curve calculation, the refrigerant flow change ratio is nearly equal to a constant, so it is easy to calculate the number of pulses per adjustment by the control algorithm, reduce the number of adjustments, improve the stability of the system, and reduce the energy consumption of the system. DRAWINGS

Figure 1: Relationship between the valve core and the spool seat structure of an electronic expansion valve of the prior art; Fig. 2: Flow rate curve of the electronic expansion valve of Fig. 1;

Figure 3: A typical electronic expansion valve structure diagram of the present invention;

Figure 4: Structural diagram of a preferred spool and spool seat for the electronic expansion valve in Figure 3; Figure 4a: Diagram of the movement of the spool to the HI point in Figure 4;

Figure 4b: Diagram of the movement of the spool in Figure 4 to the H2 point;

Figure 5: Another preferred spool and spool seat structure diagram for the electronic expansion valve in Figure 3; Figure 6: Flow rate curve for the electronic expansion valve in Figure 3.

The symbols in the figure indicate:

100-coil, 200-magnetic rotor, 300-isolator;

400-valve body; 401-flow path inlet;

402-flow path outlet, 500-inner cavity, 600-over pipe;

700/310-valve seat;

701-valve portion, 702-conical opening section;

800/314-valve;

801- body segment, 802-adjustment segment; 803-conical transition section, 804-adjustment reference plane;

805-first arc segment, 806-second arc segment, 807-third arc segment;

900-screw, 901-nut;

L1-valve opening section, L2-flow regulation section. detailed description

[18] In order to make those skilled in the art better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to the drawings and specific embodiments.

[19] Please refer to FIG. 3. FIG. 3 is a structural diagram of a typical electronic expansion valve according to the present invention.

[20] The electronic expansion valve generally includes a coil 100 disposed on the outer circumference of the metal spacer 300 and a magnetic rotor 200 disposed on the inner circumference of the metal spacer 300. The coil 100 and the magnetic rotor 200 cooperate with each other to form an electronic expansion valve. Drive parts.

[21] The valve body 400 having the flow path inlet 401 and the flow path outlet 402 is hermetically welded to the spacer 300 to form the inner cavity 500. The two nozzles 600 are welded to the valve body 400 and communicate with the flow path inlet 401 and the flow path outlet 402, respectively. A spool seat 700 having a valve port portion 701 is welded and fixed to the valve body 400. The drive screw 900 is fixedly coupled to the magnetic rotor 200 to transmit the rotation of the magnetic rotor 200, and a needle-shaped spool 800 is disposed at the front end of the screw 900. The valve body 400, the nozzle 600, the spool seat 700, and the valve body 800 constitute a valve body member.

[22] The working principle of the above electronic expansion valve is that when the flow rate of the electronic expansion valve needs to be adjusted, an appropriate pulse signal is applied to the coil 100, and the magnetic rotor 200 rotates under the driving of the coil 100, and drives the screw 900 to rotate simultaneously. The screw rod 900 is in a threaded engagement with the nut 901 fixed on the valve body 400. Since the nut 901 is fixed on the valve body 400, the screw rod 900 is also moved up and down in the axial direction while rotating, thereby driving the valve body 800. The up and down movement causes the spool 800 to move axially relative to the valve port portion 701 of the spool seat 700 to change the flow rate of the refrigerant passing through the valve port portion 701 to achieve flow control of the refrigeration system.

[23] Figure 4 is a structural diagram of a preferred spool and spool seat of the electronic expansion valve of Figure 3; Figure 4a is Diagram of the position of the spool moving to the HI point; Figure 4b is the relationship of the spool moving to the H2 position.

[24] As shown in Figure 4, Figure 4a and Figure 4b. In the present embodiment, the spool 800 includes a body section 801 coupled to the aforementioned threaded rod 900 and an adjustment section 802 that faces the spool seat 700. The body section 801 is coupled to the adjustment section 802 by a tapered transition section 803. In the present embodiment, adjustment segment 802 includes a first arc segment 805. The design of the positional relationship of the first circular arc segment 805 is defined in the following description. The valve port portion 701 of the spool seat 700 is a straight segment having a diameter of Φ2, and the spool seat 700 is directed upward from the valve port portion 701 toward the spool 800. Extending into a tapered opening section 702. The point of the first arc segment 805 of the spool 800 is designed to define a refrigerant flow rate change curve by forming a specific parameter by the positional relationship with the valve port portion 701 of the spool seat 700.

[25] The tapered transition section 803 of the spool 800 can define a small end diameter of Φ3 and a large end diameter of Φ5, and the diameter Φ2 of the straight valve port portion 701 of the spool seat 700 satisfies the relationship: Φ3<Φ2< Φ5. Further, since Φ3 < Φ2 < Φ5, it can be determined that on the tapered transition section 803 of the spool 800, a transverse section can be found, the diameter of which is equal to the diameter Φ2 of the valve port portion 701 of the straight section of the spool seat 700, The section is defined as an adjustment reference plane 804.

[26] Since Φ3 < Φ2 < Φ5, when the electronic expansion valve is in the closed position, the tapered transition portion 803 of the spool 800 abuts against the straight port portion 701 of the spool seat 700, so when the valve is just opened, The tapered transition section 803 of the spool 800 functions. Generally, the pulse is applied in this area, the valve port is in the just-open position, the flow control is unstable, and it is not called the normal adjustment area, and is called the "valve opening section". As the number of pulses increases, after the pulse is greater than 100, the adjustment section 802 (the first arc segment 805) of the spool 800 and the valve port portion 701 of the straight section of the valve cartridge seat 700 form an adjustment of the control flow area. The normal flow adjustment range is called the “flow adjustment section”.

[27] In the normal flow adjustment range, the spool 800 and the spool seat 700 may be defined as follows when they are at a relative position (such as point X, not shown): 1 adjust the reference surface 804 to the valve port 701 The axial distance of the upper tip is defined as Ηχ; the vertical shortest distance from the upper end of the valve port portion 701 to the first arc segment 805 of the valve body 800 is defined as Αχ, the upper end of the valve port portion 701 to the valve body 800 The longitudinal direction of a circular arc segment 805 The distance to the Bx is 3; the flow area of the valve port is defined as Sx. According to the above definition, the valve port flow area Sx at the X point can be calculated as follows: Sx = 3.14XAxX(03-Bx) + 3.14X (Φ2 ² - Φ3 ² ) /4.

[28] According to the above definition, when the spool 800 moves away from the valve port portion 701 through any two points

(First point and second point), you can get the values of two points (Hl, Al, Bl, SI) and (H2, A2, B2, S2). If the thread pitch of the screw 900 is P, and the number of pulses required for one rotation of the screw 900 is Q, the number of pulses required for the valve 800 to rise from the first position to the second position is W=(H2- H1) / PXQ. Then, by designing Ax and Bx, the arc surface of the first arc segment 805 is designed to satisfy the relationship: S2/S1 is open to the power of W is approximately constant value, that is, 3⁄4^1 ^, K is a constant.

[29] According to the above definition, after the spool 800 performs the stroke range for adjusting the flow rate, or after the number of pulses is greater than 100, when the spool 800 moves away from the valve port portion 701, the spool 800 is arbitrarily moved by two axial distances. The equal interval can be defined as: the flow area of the valve port portion 701 at the start position of the first stage is S3, the flow area of the valve port portion 701 at the end position is S4, and the flow area of the valve port portion 701 at the start position of the second stage is S5, the flow area of the valve port portion 701 at the end position is S6, then the relationship is satisfied: S4/S3 is approximately equal to S6/S5, gpS4/S3«S6/S5.

[30] Figure 6 is a graph showing the flow rate corresponding to the electronic expansion valve of Figure 3. As shown in Figure 6. The flow curve can define the abscissa as the input pulse signal R value, and the ordinate as the refrigerant flow W value. The flow curve includes the valve port opening section L1 and the flow regulating section L2 connecting the valve port opening section L1. Valve opening section L1, belonging to the small pulse section, the valve port is in the just open position, the flow control is unstable, this stage is mainly to open the valve port; in the flow adjustment section L2, as the pulse number is greater than 100, the electronic expansion valve enters Normal flow adjustment range. In the flow adjustment section L2, the curvature of the curve is set to increase gradually, that is, as the number of pulses increases, the flow curve changes more steeply, and in the entire flow adjustment section L2, there is no sudden breakpoint, and the curve is smooth. Shape line.

[31] Two points (such as VI and V2) can be set arbitrarily in the valve opening direction on the flow adjustment section L2. The definition of the VI coordinate is (Rl, Wl) and the V2 coordinate is (R2, W2), then the relationship is satisfied: W2/W1) open (R2-R1) The power of the power is approximately constant, βΡ

κ, K is a constant.

[32] In the flow adjustment section L2, arbitrarily set the two sections with the same abscissa distance as the (V3-V4) and (V5-V6) sections, and define the ordinate corresponding to the (V3-V4) section curve. The starting point is W3 and the ending point is W4. The starting point of the abscissa corresponding to the curve of (V3-V4) is R3 and the ending point is R4. The starting point of the ordinate of the curve defined by (V5-V6) is W5 and the ending point is W6, (V5- The starting point of the abscissa corresponding to the V6) segment curve is R5 and the ending point is R6. Under the condition of R6 - R5 = R4 - R3, the relationship is satisfied: W6/W5 is approximately equal to W4/W3, gp W6 / W5 « W4 / W3.

Figure 5 is a block diagram of another preferred spool of the electronic expansion valve of Figure 3. As shown in Fig. 5, the present embodiment differs from the foregoing in that the adjustment section 802 of the spool 800 includes three arcs: a first circular arc segment 805, a second arc segment 806, and a third arc segment 807. The radius of curvature of the first arc segment 805 is greater than the second arc segment 806, the radius of curvature of the second arc segment 806 is greater than the third arc segment 807, and the first arc segment 805 is tangent to the second arc segment 806. The second arc segment 806 is tangent to the third arc segment 807. The three-section tangential arc forms the adjustment section 802 of the valve core 800 for the purpose of optimizing the design. This is because, in some complicated systems, it is difficult to set a circular arc on the valve core to meet the parameter requirements of the refrigerant flow area, and setting a plurality of tangential arcs can simplify the design of the flow rate curve.

[34] According to the control requirements and parameter design comparison of the general electronic expansion valve, preferably, if a three-section tangent arc is used, the curvature of the first segment arc 805 is twice the curvature of the third segment arc 807 or More than twice.

[35] Of course, only two tangential arcs can form the valve core, which can also achieve the required purpose, and will not be described here.

[36] It should be understood that the above relationship may also be satisfied in the scheme in which the adjusting section 802 of the valve body 800 is provided with a plurality of arcs, and the description thereof is the same as the foregoing, and will not be described herein.

[37] The electronic expansion valve disclosed in the present invention, the head of the valve core is composed of a circular arc or a plurality of tangential arcs of different radii, which can ensure a small flow change in a small opening degree, and a flow change in a large opening area. Larger, and there is no sudden change in the two, which is convenient for air conditioning system adjustment. Another aspect of the invention disclosed Electronic expansion valve, the flow rate change ratio is close to a constant, it is easy to calculate the number of pulses per adjustment by the control algorithm, reduce the number of adjustments, improve the stability of the system, and reduce the energy consumption of the system.

[38] It should be noted that the above, the first, the lower, the left, the right, the front, the back, the inner and the outer and the like are all mentioned in order to facilitate the description of the technical solution of the present invention. The subject matter is not to be construed as limiting the invention.

[39] Due to the finiteness of the textual expression, there are infinitely specific structures in the objective, and those skilled in the art can make some improvements and refinements without departing from the principle of the present invention. These improvements and finishes should also be considered as protection of the present invention.

Claims

claims

1. An electronic expansion valve, including a driving component and a valve body component. The valve body component includes a valve body (400) with a flow path inlet and a flow path outlet, and an inner cavity placed in the valve body (400). The valve core (800) in (500) and the valve core seat (700) with the valve port portion (701) drive the valve core (800) relative to the valve by inputting a pulse signal to the driving component. The axial movement of the mouth (701) changes the flow area of the valve mouth (701) and adjusts the refrigerant flow rate flowing into the electronic expansion valve, which is characterized in that:

The valve core (800) includes a main body section (801) and an adjustment section (802) facing the valve core seat (700). The main body section (801) and the adjustment section (802) pass through a tapered transition section. (803) connection, the adjustment section (802) includes a first arc section (805) used to adjust the refrigerant flow change curve,

The valve core seat (700) includes a straight section of the valve mouth portion (701) and a tapered opening section (702) extending from the valve mouth portion (701) toward the valve core (800). , the diameter of the valve port portion (701) is defined as Φ2, the small end diameter of the tapered transition section (803) of the valve core (800) is defined as Φ3 and the large end diameter is defined as Φ5, then the relationship Φ3< Φ2<Φ5.

2. The electronic expansion valve according to claim 1, characterized in that the adjustment section (802) of the valve core (800) further includes a second arc section connected to the first arc section (805). (806), the first arc segment (805) is tangent to the second arc segment (806), and the radius of curvature of the first arc segment (805) is greater than the second arc segment (806). 806) radius of curvature.

3. The electronic expansion valve according to claim 2, wherein the adjustment section (802) of the valve core (800) further includes a third arc section connected to the second arc section (806). (807), the second arc segment (806) is tangent to the third arc segment (807), and the radius of curvature of the second arc segment (806) is greater than the third arc segment (807). 807) radius of curvature.

4. The electronic expansion valve according to claim 3, wherein the curvature radius of the first arc segment (805) is twice or twice the curvature radius of the third arc segment (807). above.

5. The electronic expansion valve according to any one of claims 1 to 4, characterized in that, in the valve Within the stroke range in which the core (800) adjusts the flow rate, when the valve core (800) moves axially from the first position to the valve opening direction relative to the valve core seat (700) to the second position, it is defined that the movement The number of pulses required for this distance is W. The flow area of the valve port (701) when the valve core (800) is in the first position is defined as S1. The valve core (800) is in the first position. The flow area of the valve port (701) in the second position is S2, which satisfies the relationship: S2/S1 opened to the power W is approximately a constant value, that is, ^w sirsi ^ K, where κ is a constant.

6. The electronic expansion valve according to any one of claims 1 to 4, characterized in that, within the flow range of the valve core (800) with an input pulse number greater than 100, when the valve core (800) ) relative to the valve core seat (700) when axially moving from the first position to the valve opening direction to the second position, define the number of pulses required to move this distance as W, define the valve core (800) in When the valve core (800) is in the second position, the flow area of the valve port portion (701) is S1, and when the valve core (800) is in the second position, the flow area of the valve port portion (701) is S2, then it satisfies Relational formula: S2/S1 opened to the W power is approximately a constant value, that is, ¾^1«, where K is a constant.

7. The electronic expansion valve according to any one of claims 1 to 4, characterized in that, within the stroke range in which the valve core (800) adjusts the flow rate, the valve core (800) is relative to the flow rate. The valve core seat (700) moves in any two sections with equal axial distance in the valve opening direction. Definition: The flow area of the valve port (701) at the starting position of the first section is S3, and the flow area of the valve port (701) at the end position is S3. The flow area of the mouth (701) is S4; the flow area of the valve mouth (701) at the starting position of the second stage is S5, and the flow area of the valve mouth (701) at the end position is S6, then it is satisfied Relationship: S4/S3 and S6/S5 are approximately equal, §=54 / S3 6 / 55.

8. The electronic expansion valve according to any one of claims 1 to 4, characterized in that, within the flow range of the valve core (800) with an input pulse number greater than 100, the valve core (800) ) moves any two sections with equal axial distance relative to the valve core seat (700) in the valve opening direction. Definition: The flow area of the valve port (701) at the starting position of the first section is S3, and the end position When the flow area of the valve port (701) is S4; when the starting point of the second section is The flow area is S5, and the flow area of the valve port (701) at the end position is S6, then the relationship is satisfied: S4/S3 and S6/S5 are approximately equal, S ^4/^3* ^6/^5 ₀

9. An electronic expansion valve, including a driving component and a valve body component. The valve body component includes a valve body (400) with a flow path inlet and a flow path outlet, and an inner cavity placed in the valve body (400). The valve core (800) in (500) and the valve core seat (700) with the valve port portion (701) drive the valve core (800) relative to the valve by inputting a pulse signal to the driving component. The axial movement of the mouth (701) changes the flow area of the valve mouth (701) and adjusts the refrigerant flow rate flowing into the electronic expansion valve, which is characterized in that:

The valve core (800) includes a main body section (801) and an adjustment section (802) facing the valve core seat (700). The main body section (801) and the adjustment section (802) pass through a tapered transition section. (803) connection, the adjustment section (802) includes at least one arc section (805, 806, 807) used to adjust the refrigerant flow change curve,

The refrigerant flow change curve defines the abscissa as the input pulse signal number R value, the ordinate as the refrigerant flow W value of the valve port portion (701), and the refrigerant flow change curve includes a valve opening section ( L1) and a flow adjustment section (L2) for adjusting the flow rate. The flow adjustment section (L2) is a curve with increasing curvature.

10. The electronic expansion valve according to claim 9, characterized in that the flow adjustment section (L2) of the refrigerant flow change curve is a smooth arc-shaped line.

11. The electronic expansion valve according to claim 9 or 10, characterized in that two points are arbitrarily set in the flow adjustment section (L2), and the coordinates of the first point in the valve opening direction are defined as (R1, Wl), the coordinates of the second point are (R2, W2), then the relationship is satisfied: (W2/W1) raised to the power of (R2-R1) is an approximate constant, gP ⁽ K2-w^7 K, where K is a constant .

12. The electronic expansion valve according to claim 9 or 10, characterized in that, in the flow adjustment section (L2), two curves with equal abscissa distances are arbitrarily set to define the first section in the valve opening direction. The starting point of the ordinate corresponding to the curve is W3 and the end point is W4. The starting point of the ordinate corresponding to the second segment of the curve is W3. The point is W5 and the end point is W6, then the relationship is satisfied: W6/W5 is approximately equal to W4/W3, that is, W6/W5«W4/W3.