Automobile air conditioner electronic expansion valve, control system and control method

Abstract

The invention relates to an automobile air conditioner electronic expansion valve, a control system and a control method. The valve comprises a valve body and an execution module, the valve body is provided with a valve seat, a refrigerant input port and a refrigerant output port, a valve rod is arranged in the execution module, the execution module is composed of a shell, an actuator and the valve rod, and the actuator is formed by connecting a plurality of electromagnetic telescopic units end to end. Each electromagnetic telescopic unit can be independently controlled to extend and retract in the vertical axial direction, and therefore the valve rod can be driven to be maintained at different heights. The electromagnetic type electronic expansion valve has multiple flow gears, compared with an existing electric type electronic expansion valve, the actuator is low in manufacturing cost and control difficulty, and compared with an existing electromagnetic type electronic expansion valve, the electromagnetic type electronic expansion valve has multiple gears, the flow adjusting range is obviously widened, and therefore the electromagnetic type electronic expansion valve can be applied to vehicle-mounted refrigeration.

Description

Technical Field

[0001] This invention relates to an expansion valve, and more particularly to an electronic expansion valve for automotive air conditioning, a control system, and a control method. Background Technology

[0002] The expansion valve is a key component in a refrigeration system, primarily used to throttle and reduce the pressure of the refrigerant, control its flow rate, and ensure sufficient evaporation and heat absorption of the refrigerant in the evaporator. The expansion valve senses the evaporator outlet temperature through a temperature-sensing bulb, which is filled with a low-boiling-point liquid (such as ethers or fluorinated substances). When the temperature rises, the liquid vaporizes, pushing the diaphragm downwards, increasing the valve opening and thus increasing the refrigerant flow rate; conversely, when the temperature decreases, the opposite occurs, maintaining the evaporator superheat between 5-8°C through dynamic equilibrium. This mechanism prevents liquid refrigerant from entering the compressor, protecting the system.

[0003] The main types of common expansion valves are thermal expansion valves and electronic expansion valves. Electronic expansion valves control refrigerant flow through the on / off switching of a solenoid valve, offering faster response and higher precision. Electronic expansion valves are further divided into electric electronic expansion valves and electromagnetic electronic expansion valves. Electric electronic expansion valves are driven by stepper motors or DC motors, offering high adjustment precision and a wide adjustment range, suitable for applications such as air conditioning and cold storage. Their advantages include good steady-state control performance, long lifespan, and superior overall performance, but their higher overall production cost leads to a higher purchase price. Electromagnetic electronic expansion valves drive the valve core through electromagnetic force, offering fast response and relatively lower cost, but their adjustment range is smaller, only allowing for fully open / fully closed states.

[0004] Therefore, developing an electronic expansion valve that has multiple adjustment ranges and a relatively low cost is of great significance to the refrigeration industry. Summary of the Invention

[0005] This invention provides an electronic expansion valve for automotive air conditioning, a control system, and a control method; solving the problem in the prior art that the expansion valve cannot simultaneously meet the requirements of a large adjustment range and a low cost.

[0006] The above-mentioned technical problems of the present invention are mainly solved by the following technical solution: an electronic expansion valve for automotive air conditioning, comprising a valve body and an actuator module, wherein the valve body is provided with a valve seat, a refrigerant inlet and a refrigerant outlet, a high-pressure chamber and a low-pressure chamber are respectively formed on the upper and lower sides of the valve seat, and a valve hole connecting the upper and lower sides is formed on the valve seat, the refrigerant inlet is connected to the high-pressure chamber, and the refrigerant outlet is connected to the low-pressure chamber, wherein the actuator module is provided with a valve stem extending into the high-pressure chamber and facing the valve seat, the actuator module is composed of a housing, an actuator and the valve stem, the housing is fixed to the upper side of the valve body, and a vertical guide hole is provided inside the housing, the valve stem is slidably and sealingly assembled in the guide hole, the actuator is composed of a plurality of electromagnetic telescopic units connected end to end, one end of the actuator is fixed relative to the housing, and the other end is fixed relative to the valve stem, each electromagnetic telescopic unit can be independently controlled to extend and retract along the vertical axis, thereby driving the valve stem to maintain at different heights.

[0007] The main difference between this invention and existing electronic expansion valves lies in the actuator within the execution module. This actuator consists of multiple electromagnetic telescopic units connected in series. Each electromagnetic telescopic unit is electrically connected to a controller. The controller controls the on / off state of the corresponding electromagnetic telescopic unit, enabling the unit to extend and retract vertically. This allows for free control of the overall height of the actuator in the vertical direction. Changes in the actuator's height are reflected in changes in the valve stem's height, resulting in changes in the gap between the valve stem and the valve seat. A larger gap corresponds to a larger refrigerant flow, and a smaller gap corresponds to a smaller refrigerant flow. Therefore, the number of height modes of the actuator is equivalent to the number of gears in this invention, specifically N (number of electromagnetic telescopic units) + 1.

[0008] Furthermore, the lower end of the valve stem is provided with a multi-stage valve needle. The multi-stage valve needle has several segments with progressively smaller outer diameters from top to bottom. The number of segments is the same as the number of electromagnetic telescopic units. The length of each segment is the telescopic stroke of the electromagnetic telescopic unit, and the outer diameter of any segment is smaller than the diameter of the valve orifice. When the valve stem is in the highest position, the multi-stage valve needle is completely separated from the valve orifice, and the valve orifice is fully open, corresponding to the full flow rate setting. As the valve stem descends a certain distance, a corresponding segment is inserted into the valve orifice. With each decrease in valve stem height, the outer diameter of the segment gradually increases, thus the corresponding flow rate gradually decreases.

[0009] Furthermore, the electromagnetic telescopic unit comprises a first annular seat, a second annular seat, a coil, and a first return spring. An annular iron disc is coaxially fixed to the first annular seat, and an annular iron core, directly opposite the annular iron disc, is fixed to the second annular seat. The coil is wound around the annular iron core. When the coil is energized, the annular iron core generates magnetism, thereby attracting the annular iron disc. At this time, the distance between the first and second annular seats is minimal, and the first return spring is in an energy-storing state. Conversely, when the coil is de-energized, the magnetism of the annular iron core disappears instantly, and under the action of the first return spring, the distance between the first and second annular seats returns to its original state.

[0010] This invention also provides a control system for an expansion valve, including a controller, an actuator, and a sensor, characterized in that: the actuator is the aforementioned automotive air conditioning electronic expansion valve. Since the aforementioned automotive air conditioning electronic expansion valve has the above-mentioned technical effects, the control system having this electronic expansion valve also has the same technical effects.

[0011] This invention also provides a control method for an expansion valve, characterized in that: the controller collects the pressure and temperature at the evaporator outlet in real time through a sensor; based on the collected data, the controller uses a fixed formula to convert and calculate the superheat at the evaporator outlet, and then performs electrical control on the actuator on the actuator according to a preset program; by controlling the state of different actuators, the height of the valve stem can be adjusted, thereby accurately controlling the real-time flow rate of the refrigerant liquid.

[0012] Therefore, compared with the prior art, the present invention has the following characteristics: 1. The actuator is composed of multiple electromagnetic telescopic units connected in series. Each electromagnetic telescopic unit is electrically connected to the controller. The controller can realize the extension and retraction of the electromagnetic telescopic unit in the vertical axis by controlling the circuit of the corresponding electromagnetic telescopic unit. Thus, the overall height of the actuator in the vertical axis can be freely controlled, with multiple height levels. The change in the height of the actuator is reflected as the change in the height of the valve stem, thereby realizing the change in the gap between the valve stem and the valve seat, and finally realizing multiple flow levels. Therefore, the present invention belongs to an electromagnetic electronic expansion valve. Compared with the existing electric electronic expansion valve, the actuator is relatively inexpensive and easier to control. Compared with the existing electromagnetic electronic expansion valve, the present invention has multiple levels and the flow adjustment range is significantly improved. Therefore, it can be applied to vehicle refrigeration. Attached Figure Description

[0013] Appendix Figure 1 This is a schematic diagram of the structure of the electronic expansion valve of an automotive air conditioner when it is at its minimum flow rate;

[0014] Appendix Figure 2 This is a schematic diagram of the structure of the electronic expansion valve of an automotive air conditioner when it is at full flow.

[0015] Appendix Figure 3 This is a schematic diagram of the actuator.

[0016] Appendix Figure 4 This is a schematic diagram of the electromagnetic telescopic unit when it is in a contracted state;

[0017] Appendix Figure 5 This is a schematic diagram of the electromagnetic telescopic unit when it is in the extended state. Detailed Implementation

[0018] The technical solution of the present invention will be further described in detail below through embodiments and in conjunction with the accompanying drawings.

[0019] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0020] Example 1: See Figure 1 and Figure 2 An electronic expansion valve for automotive air conditioning includes a valve body 100 and an actuator module 200. The valve body has a valve seat 10, a refrigerant inlet 20, and a refrigerant outlet 30. A high-pressure chamber 11 and a low-pressure chamber 12 are formed on the upper and lower sides of the valve seat, respectively. A valve hole 13 connecting the upper and lower sides is formed on the valve seat. The refrigerant inlet communicates with the high-pressure chamber, and the refrigerant outlet communicates with the low-pressure chamber. The actuator module has a valve stem 40 extending into the high-pressure chamber and facing the valve seat. The actuator module consists of a housing 50, an actuator 60, and the valve stem. The housing is fixed to the upper side of the valve body and has a vertical guide hole 51 inside. The valve stem is slidably and sealed within the guide hole. The actuator consists of three electromagnetic telescopic units connected end-to-end: a first electromagnetic telescopic unit 701, a second electromagnetic telescopic unit 702, and a third electromagnetic telescopic unit 703. The three are vertically connected end-to-end (see [reference]). Figure 3 ).

[0021] See Figure 4 and Figure 5The electromagnetic telescopic unit consists of a first annular seat 71, a second annular seat 72, a coil 73, and a first return spring 74. An annular iron disc 75 is coaxially fixed to the first annular seat, and an annular iron core 76, directly opposite the annular iron disc, is fixed to the second annular seat. The coil is wound around the annular iron core. When the coil is energized, the annular iron core generates magnetism, attracting the annular iron disc. At this time, the distance between the first and second annular seats is minimal, and the first return spring is in an energy-storing state. Conversely, when the coil is de-energized, the magnetism of the annular iron core disappears instantly, and under the action of the first return spring, the distance between the first and second annular seats returns to its original state. The length change of the electromagnetic telescopic unit is 3mm.

[0022] See Figure 1 The first annular seat on the first electromagnetic telescopic unit is fixed to the housing, and the second annular seat on the third electromagnetic telescopic unit engages with and limits the upper end of the valve stem; a second return spring 80 is connected between the valve stem and the bottom of the housing. Under the constraint of the second return spring, the valve stem always tends to move upward, but the magnetic force generated by the annular iron core inside the electromagnetic telescopic unit can simultaneously resist the work done by the two return springs.

[0023] See Figure 1 and Figure 2 The lower end of the valve stem is equipped with a multi-stage valve needle 90, which has three segments 91 with progressively smaller outer diameters from top to bottom. Each segment is 3mm long, and the outer diameter of any segment is smaller than the diameter of the valve orifice. When the valve stem is in the highest position, the multi-stage valve needle is completely separated from the valve orifice, and the valve orifice is fully open, corresponding to the full flow rate. As the valve stem descends a certain distance, a corresponding segment is inserted into the valve orifice. As the valve stem descends, the outer diameter of the segment gradually increases, thus the corresponding flow rate gradually decreases.

[0024] See Figure 1 To prevent refrigerant from seeping into the actuator through the guide hole, at least two sealing rings 52 are provided inside the guide hole, and this part is filled with sealing grease to assist in sealing and lubrication.

[0025] See Figure 1 The upper side of the valve body is provided with a rotating sleeve 14 that communicates with the high-pressure chamber, and the bottom of the housing is provided with a rotating seat 53 that forms a sealed connection with the rotating sleeve.

[0026] The main difference between this embodiment and existing electronic expansion valves lies in the actuator within the execution module. This actuator consists of three electromagnetic telescopic units connected in series. Each electromagnetic telescopic unit is electrically connected to the controller. By controlling the on / off state of the circuit of the corresponding electromagnetic telescopic unit, the controller can extend and retract the electromagnetic telescopic unit in the vertical axis, thereby freely controlling the overall height of the actuator in the vertical axis. The change in the height of the actuator is reflected in the change in the height of the valve stem, which in turn causes a change in the gap between the valve stem and the valve seat. When the gap increases, the refrigerant flow rate increases accordingly; when the gap decreases, the refrigerant flow rate decreases accordingly. In the first position of this embodiment, all electromagnetic telescopic units are in the retracted state, the valve stem is at its lowest position, and the thickest segment of the multi-stage valve needle is inserted into the valve hole, resulting in the minimum flow rate. In the second position of this embodiment, only one electromagnetic telescopic unit is in the extended state, resulting in a higher flow rate than the first position. In the third position of this embodiment, only two electromagnetic telescopic units are in the extended state, resulting in a higher flow rate than the second position. In the fourth position of this embodiment, all three electromagnetic telescopic units are in the extended state, the valve stem is at its highest position, the multi-stage valve needle is separated from the valve hole, resulting in the maximum flow rate.

[0027] This embodiment also discloses a control system for an expansion valve, including a controller, an actuator, and a sensor, wherein the actuator is the aforementioned automotive air conditioning electronic expansion valve. Since the aforementioned automotive air conditioning electronic expansion valve has the above-described technical effects, the control system with this electronic expansion valve also has the same technical effects. The installation positions of the controller and actuator in this embodiment are the same as those of existing expansion valve control systems, and will not be described again here.

[0028] This embodiment also discloses a control method for an expansion valve. The controller collects the pressure and temperature at the evaporator outlet in real time through a sensor. Based on the collected data, the controller uses a fixed formula to convert and calculate the superheat at the evaporator outlet. Then, it performs electrical control on the actuator on the actuator according to a preset program. By controlling the state of different actuators, the height of the valve stem can be adjusted, thereby accurately controlling the real-time flow rate of the refrigerant liquid.

[0029] It will be apparent to those skilled in the art that the present invention can be modified in various ways, and such modifications are not considered to depart from the scope of the invention. All such modifications that are obvious to those skilled in the art are included within the scope of the claims.

Claims

1. An electronic expansion valve for automotive air conditioning, comprising a valve body and an actuator module, wherein the valve body is provided with a valve seat, a refrigerant inlet, and a refrigerant outlet; a high-pressure chamber and a low-pressure chamber are respectively formed on the upper and lower sides of the valve seat; a valve hole communicating with the upper and lower sides is formed on the valve seat; the refrigerant inlet communicates with the high-pressure chamber; the refrigerant outlet communicates with the low-pressure chamber; and the actuator module is provided with a valve stem extending into the high-pressure chamber and facing the valve seat, characterized in that: The execution module consists of a housing, an actuator, and a valve stem. The housing is fixed to the upper side of the valve body and has a vertical guide hole inside. The valve stem is slidably and sealingly assembled in the guide hole. The actuator is composed of several electromagnetic telescopic units connected end to end. One end of the actuator is fixed relative to the housing, and the other end is fixed relative to the valve stem. Each electromagnetic telescopic unit can be independently controlled to extend and retract along the vertical axis, thereby driving the valve stem to maintain at different heights.

2. The automotive air conditioning electronic expansion valve according to claim 1, characterized in that: The lower end of the valve stem is provided with a multi-stage valve needle. The multi-stage valve needle has several segments with progressively smaller outer diameters from top to bottom. The number of segments is the same as the number of electromagnetic telescopic units. The length of each segment is the telescopic stroke of the electromagnetic telescopic unit. The outer diameter of any segment is smaller than the diameter of the valve hole.

3. The automotive air conditioning electronic expansion valve according to claim 1 or 2, characterized in that: The electromagnetic telescopic unit consists of a first annular seat, a second annular seat, a coil, and a first return spring. An annular iron disc is coaxially fixed on the first annular seat, and an annular iron core opposite to the annular iron disc is fixed on the second annular seat. The coil is wound around the annular iron core.

4. The automotive air conditioning electronic expansion valve according to claim 3, characterized in that: The electromagnetic telescopic unit consists of three parts: a first electromagnetic telescopic unit, a second electromagnetic telescopic unit, and a third electromagnetic telescopic unit. The three parts are connected end to end in the vertical direction. The first annular seat on the first electromagnetic telescopic unit is fixed to the housing. The second annular seat on the third electromagnetic telescopic unit engages with and limits the upper end of the valve stem. A second return spring is connected between the valve stem and the bottom of the housing.

5. The automotive air conditioning electronic expansion valve according to claim 1, characterized in that: The guide hole is provided with several sealing rings.

6. The automotive air conditioning electronic expansion valve according to claim 1, characterized in that: The upper side of the valve body is provided with a rotating sleeve that communicates with the high-pressure chamber, and the bottom of the housing is provided with a rotating seat that forms a sealed connection with the rotating sleeve.

7. A control system for an expansion valve, comprising a controller, an actuator, and a sensor, characterized in that: The actuator is the automotive air conditioning electronic expansion valve as described in any one of claims 1 to 6.

8. A control method for an expansion valve, characterized in that: The controller collects the pressure and temperature at the evaporator outlet in real time through sensors. Based on the collected data, the controller uses a fixed formula to convert and calculate the superheat at the evaporator outlet. Then, it performs electrical control on the actuators on the actuator according to the preset program. By controlling the state of different actuators, the height of the valve stem can be adjusted, thereby accurately controlling the real-time flow of refrigerant liquid.

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