Thermostatic expansion valve

Abstract

The application provides a thermal expansion valve, which comprises a valve body, a push rod, a valve core, an adjusting mechanism, a power head, the adjusting mechanism comprises a first spring seat, a first spring, an adjusting nut, a first elastic claw and a support seat, the power head comprises an upper cover and a lower cover fixed together, and a diaphragm fixed between the upper cover and the lower cover can change according to the temperature and pressure of refrigerant from an evaporator; characterized in that the adjusting mechanism is fixed to the inner cavity of the bottom of the valve body, the first spring seat abuts against the valve core, one end of the first spring abuts against the first spring seat and the other end abuts against the support seat, the adjusting nut is U-shaped, the support seat is installed in the inner cavity of the adjusting nut, the support seat is provided with a flow collecting hole in the center, the U-shaped side wall below the support seat has a plurality of flow-through holes, and the U-shaped outer side wall of the adjusting nut is matched with the inner cavity side wall of the bottom of the valve body. Through the flow collecting hole in the center of the support seat, the refrigerant is basically uniformly distributed and flows into the valve port throttling expansion, so that the refrigerant throttling noise is reduced.

Description

Technical Field

[0001] This invention relates to the field of refrigeration and air conditioning, and particularly to a thermostatic expansion valve. Background Technology

[0002] In the refrigeration cycle of an air conditioning unit, there are generally a compressor, condenser, receiver, expansion valve, and evaporator. Thermostatic expansion valve is a throttling component commonly used in air conditioning and refrigeration equipment. It can throttle and reduce the pressure of liquid refrigerant from the condenser, and adjust the flow rate of refrigerant from the condenser to the evaporator according to the temperature at the evaporator outlet to adapt to the constantly changing needs of the cooling load.

[0003] Existing thermostatic expansion valves, such as the one disclosed in Chinese patent application 201711491135.2, open and close the valve orifice by sensing the temperature and pressure of the refrigerant at the evaporator outlet side using a power head, and control the refrigerant flow rate supplied to the evaporator so that the refrigerant discharged from the evaporator has a predetermined superheat. The valve body of the expansion valve has a first channel for introducing refrigerant from the receiver to the evaporator, and a second channel for discharging refrigerant from the evaporator to the compressor. A valve orifice is provided in the middle of the first channel, and a valve core is used to adjust the valve orifice opening. A power head is provided at the top of the valve body to sense the temperature and pressure of the refrigerant flowing through the second channel to adjust the valve orifice opening; the driving force of the power head is transmitted to the valve core by a push rod. However, because the centerline of the valve orifice is longitudinal and the centerline of the inlet channel (first interface) is transverse, when the refrigerant flows through the valve orifice in a throttling manner, a serious problem of inlet and outlet refrigerant flow deviation occurs. This uneven flow leads to different degrees of refrigerant compression, and the throttling flow noise is relatively large when flowing out of the valve orifice. Summary of the Invention

[0004] The purpose of this invention is to provide a thermostatic expansion valve that can reduce throttling noise.

[0005] To solve the above-mentioned technical problems, as one aspect of the present invention, a thermostatic expansion valve is provided. The thermostatic expansion valve includes a valve body, a push rod, a valve core, an adjusting mechanism, and a power head. The adjusting mechanism includes a first spring seat, a first spring, an adjusting nut, and a support seat. The power head includes an upper cover and a lower cover fixed together. A diaphragm that can adapt to changes in refrigerant temperature and pressure from the evaporator is fixed between the upper cover and the lower cover. The adjusting mechanism is fixed in the inner cavity at the bottom of the valve body. The first spring seat abuts against the valve core. One end of the first spring abuts against the first spring seat, and the other end abuts against the support seat. The adjusting nut is U-shaped. The support seat is installed in the inner cavity of the adjusting nut. The support seat has a flow collecting hole in the center. The U-shaped sidewall of the adjusting nut located below the support seat has multiple flow holes. The outer sidewall of the U-shape of the adjusting nut cooperates with the inner cavity sidewall at the bottom of the valve body.

[0006] Furthermore, a first elastic claw is assembled between the first spring seat and the first spring, and the inner cavity of the adjusting nut is provided with a longitudinal groove, and the first elastic claw elastically resists the longitudinal groove in the inner cavity of the adjusting nut.

[0007] Furthermore, the support base is installed in the inner cavity of the adjusting nut via a threaded connection, and the flow collection hole is in the shape of an internal hexagonal nut.

[0008] Furthermore, the side of the valve body is provided with a first interface for high-temperature and high-pressure liquid refrigerant introduced from the liquid reservoir side, and a second interface for low-temperature and low-pressure refrigerant discharged to the evaporator after being throttled and depressurized by the expansion valve; the refrigerant enters the annular channel formed by the inner wall of the valve body and the outer wall of the U-shaped adjusting nut through the first interface, then enters the lower cavity of the adjusting nut through the flow hole, and then enters the upper cavity through the collection hole in the center of the support seat.

[0009] Furthermore, the flow area of ​​the manifold orifice is at least three times the maximum flow area of ​​the valve port.

[0010] Furthermore, the flow area of ​​the manifold is at most 6 times the maximum flow area of ​​the valve port.

[0011] Furthermore, the thermal expansion valve also includes a spring adjustment assembly, which includes a second spring, a second spring seat, a push rod, and a second elastic claw. The spring adjustment assembly is installed in the lower cavity of the adjusting nut, the push rod passes through the collection hole and is fixedly connected to the second spring seat, and the second elastic claw is assembled between the second spring seat and the second spring.

[0012] Furthermore, the support seat has a protrusion in the center, the protrusion has a lateral flow hole, the lateral flow hole is connected to the collection hole, and the second spring seat abuts against the protrusion of the support seat.

[0013] Furthermore, the push rod and the first spring seat maintain a predetermined distance in the installed state.

[0014] Furthermore, the stiffness of the second spring is at least 1.5 times that of the first spring.

[0015] This invention provides a thermostatic expansion valve, comprising a valve body, a push rod, a valve core, an adjusting mechanism, and a power head. The adjusting mechanism includes a first spring seat, a first spring, an adjusting nut, a first elastic claw, and a support seat. The power head includes an upper cover and a lower cover fixed together, with a diaphragm fixed between the upper and lower covers, which can adapt to changes in refrigerant temperature and pressure from the evaporator. The adjusting mechanism is fixed to the inner cavity at the bottom of the valve body. The first spring seat abuts against the valve core, one end of the first spring abuts against the first spring seat, and the other end abuts against the support seat. The adjusting nut is U-shaped, and the support seat is installed in the inner cavity of the adjusting nut. The support seat has a central collecting hole, and the U-shaped sidewall of the adjusting nut below the support seat has multiple flow holes. The outer U-shaped sidewall of the adjusting nut mates with the inner cavity sidewall at the bottom of the valve body. Through the central collecting hole of the support seat, the refrigerant flows into the valve port for throttling expansion in a basically uniform manner, reducing refrigerant throttling noise. Attached Figure Description

[0016] Figure 1 A cross-sectional view of the thermal expansion valve according to the first embodiment of the present invention is shown;

[0017] Figure 2 A cross-sectional view of the thermal expansion valve according to a second embodiment of the present invention is shown.

[0018] The attached figures are labeled as follows: Valve body 1, First interface 11, Second interface 12, Third interface 13, Fourth interface 14, Push rod 2, Valve core 3, Adjusting mechanism 4, First spring seat 41, First spring 42, Adjusting nut 43, Groove 431, Flow hole 432, First elastic claw 44, Support seat 45, Flow collecting hole 451, Protrusion 452, Lateral flow hole 453, Power head 5, Upper cover 51, Lower cover 52, Diaphragm 53, Push block 54, End cap 55, Spring adjusting assembly 6, Second spring 61, Second spring seat 62, Push rod 63, Second elastic claw 64. Detailed Implementation

[0019] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. It should be understood that the terms "upper," "lower," "left," "right," "longitudinal," "lateral," "inner," "outer," "vertical," "horizontal," "top," and "bottom," etc., which indicate orientation or positional relationships, are based solely on the orientation or positional relationships shown in the accompanying drawings and are used only for the convenience of describing the present invention and simplifying the description. They do not indicate or imply that the device / component referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the present invention.

[0020] According to a first embodiment of the present invention, Figure 1A cross-sectional schematic diagram of the thermostatic expansion valve according to the first embodiment is shown. The thermostatic expansion valve includes a valve body 1, a push rod 2, a valve core 3, an adjusting mechanism 4, and a power head 5. The adjusting mechanism includes a first spring seat 41, a first spring 42, an adjusting nut 43, a first elastic claw 44, and a support seat 45.

[0021] For ease of description, the upper end of valve body 1 in the diagram is called the top, and the lower end is called the bottom; the length direction of valve body 1 is called the longitudinal direction, and the direction parallel to the paper and perpendicular to the length direction of valve body 1 is called the transverse direction.

[0022] The valve body 1 is made of a metal profile, such as an aluminum profile, and is roughly rectangular in shape. On the side of the valve body 1, there is a first inlet 11 for high-temperature, high-pressure liquid refrigerant introduced from the receiver side, and a second inlet 12 for low-temperature, low-pressure refrigerant discharged to the evaporator after being throttled and depressurized by the expansion valve. Additionally, on the side of the valve body 1, there is a third inlet 13 for refrigerant to be introduced after evaporation in the evaporator, and a fourth inlet 14 for refrigerant to be discharged to the compressor side. The first inlet 11 and the second inlet 12 are both roughly cylindrical, laterally extending through-holes, respectively located on opposite sides of the lower part of the valve body 1. In the valve body 1, the first inlet 11, the second inlet 12, and the refrigerant passage connecting them constitute a first channel, in which a valve core 3 is located. This allows the refrigerant introduced from the first inlet 11 to expand into a mist at the valve port and flow to the evaporator via the second inlet 12. In addition, a second channel (equivalent to a return channel) is formed by the third interface 13, the fourth interface 14 and the refrigerant channel connecting them. The second channel is a roughly cylindrical through hole that runs laterally through the upper part of the valve body 1. The refrigerant introduced from the third interface 13 is discharged to the compressor through the fourth interface 14.

[0023] The adjusting mechanism 4 is fixed to the inner cavity at the bottom of the valve body 1. The first spring seat 41 abuts against the valve core 3. One end of the first spring 42 abuts against the first spring seat, and the other end abuts against the support seat 45. The adjusting nut 43 is U-shaped. The support seat 45 is installed in the inner cavity of the adjusting nut 43. The support seat 45 has a flow collection hole 451 in the center. The U-shaped sidewall of the adjusting nut 43 located below the support seat 45 has multiple flow holes 432. The outer sidewall of the U-shaped adjusting nut cooperates with the inner cavity sidewall at the bottom of the valve body 1. In this embodiment, a first elastic claw 44 is also assembled between the first spring seat 41 and the first spring 42. The inner cavity of the adjusting nut 43 has a longitudinal groove 431. The first elastic claw 44 elastically abuts against the longitudinal groove 431 in the inner cavity of the adjusting nut 43. The adjusting nut 43 is fixed to the bottom of the valve body 1. The push rod 2 is located inside the valve body 1. One end of the push rod 2 is connected to the power head 5, and the other end abuts against the valve core 3. The valve core 3 also abuts against the first spring seat.

[0024] In this embodiment, the support base 45 is threadedly installed into the inner cavity of the adjusting nut 43, dividing the inner cavity of the adjusting nut 43 into an upper cavity and a lower cavity. The flow collection hole 451 is in the shape of an internal hexagonal nut, making it convenient to screw a wrench into the inner cavity through the U-shaped opening of the adjusting nut. In the valve body 1, the refrigerant enters the annular channel 15 formed by the inner wall of the valve body and the outer wall of the U-shaped adjusting nut through the first interface 11, then enters the lower cavity of the adjusting nut 43 through the flow hole 432 for mixing, and then enters the upper cavity through the flow collection hole 451 in the center of the support base 45. The refrigerant in the upper cavity flows into the valve port with a basically uniform distribution, undergoes throttling and expansion, and flows to the evaporator through the second interface 12. Among them, the flow area of ​​the flow collection hole 451 is at least 3 times the maximum flow area of ​​the valve port. Reducing the flow collection hole 451 throttling will cause a large amount of gas-liquid mixture to enter the valve port, resulting in a large number of bubbles bursting and noise. In addition, the flow area of ​​the flow collection hole 451 is at most 6 times the maximum flow area of ​​the valve port. Experiments show that it can achieve a better flow collection effect, so that the refrigerant in the upper cavity is basically evenly distributed and flows into the valve port for throttling and expansion.

[0025] The power head 5 is fixed to the top of the valve body 1. The power head 5 includes an upper cover 51, a lower cover 52, a diaphragm 53, a push block 54, and a sealing head 55. The diaphragm 53 is located between the upper cover 51 and the lower cover 52, and the upper cover 51 and the lower cover 52 are welded together. The interior of the power head 5 is divided into an upper pressure chamber and a lower pressure chamber by the diaphragm 53. The upper pressure chamber 56 is filled with a sensing medium and is sealed by the top sealing head 55. The push block 54 is located below the diaphragm 53. The driving force generated by the displacement of the diaphragm 53 is transmitted to the valve core 3 through the push block 54 and the push rod 2 to control the opening and closing of the valve. The top of the valve body 1 also has a hollow cylindrical mounting hole. The lower cover 52 includes a straight part and a bent part. The straight part is sealed to the valve body 1, and the bent part is threaded to the valve body.

[0026] According to a second embodiment of the present invention, Figure 2 A cross-sectional schematic diagram of the thermal expansion valve according to the second embodiment is shown. The main difference between the second embodiment and the first embodiment is the addition of a spring adjusting assembly 6; other similarities with the first embodiment are indicated by the same markings.

[0027] In this embodiment, the spring adjusting assembly 6 includes a second spring 61, a second spring seat 62, a push rod 63, and a second elastic claw 64. The spring adjusting assembly 6 is installed in the lower cavity of the adjusting nut 43. The push rod 63 passes through the collection hole 451 and is fixedly connected to the second spring seat 62. The second elastic claw 64 is assembled between the second spring seat 61 and the second spring 62. In the installed state, the support base 45 has a protrusion 452 in the center, and the protrusion has a lateral flow hole 453 that connects to the collection hole 451. The second spring seat 62 abuts against the protrusion 452 of the support base 45 but does not block the collection hole 451. The push rod 63 maintains a predetermined distance from the first spring seat 41. The spring adjusting assembly 6 begins to work when the first spring seat 41 abuts against the push rod 63, and the predetermined distance is generally 60% of the total stroke. During operation, when the valve core opening is greater than 60% of the total stroke, resonance is easily generated due to refrigerant fluctuations. Therefore, the stiffness of the second spring 61 is set to be at least 1.5 times that of the first spring 42, but not more than 2 times, in order to instantly increase the resonance frequency, reduce the possibility of resonance, and not significantly change the expansion valve adjustment curve.

[0028] The above are merely preferred embodiments of the present invention and do not limit the invention. Various variations of the present invention will be apparent to those skilled in the art. Any modifications, equivalent substitutions, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A thermostatic expansion valve, comprising a valve body, a push rod, a valve core, an adjusting mechanism, and a power head; the adjusting mechanism comprising a first spring seat, a first spring, an adjusting nut, and a support seat; the power head comprising an upper cover and a lower cover fixed together, wherein a diaphragm is fixed between the upper cover and the lower cover and is adaptable to changes in refrigerant temperature and pressure from the evaporator; characterized in that: The adjusting mechanism is fixed to the inner cavity at the bottom of the valve body. The first spring seat abuts against the valve core. One end of the first spring abuts against the first spring seat, and the other end abuts against the support seat. The adjusting nut is U-shaped. The support seat is installed in the inner cavity of the adjusting nut. The support seat has a flow collection hole in the center. The U-shaped side wall of the adjusting nut located below the support seat has multiple flow holes. The outer side wall of the U-shape of the adjusting nut cooperates with the inner cavity side wall at the bottom of the valve body.

2. The thermal expansion valve according to claim 1, characterized in that: A first elastic claw is assembled between the first spring seat and the first spring. The inner cavity of the adjusting nut is provided with a longitudinal groove, and the first elastic claw elastically resists the longitudinal groove in the inner cavity of the adjusting nut.

3. The thermal expansion valve according to claim 1, characterized in that: The support base is installed in the inner cavity of the adjusting nut via a threaded connection, and the flow collection hole is shaped like an internal hexagonal nut.

4. The thermal expansion valve according to claim 1, characterized in that: The valve body has a first port on its side for high-temperature and high-pressure liquid refrigerant introduced from the liquid reservoir side, and a second port for low-temperature and low-pressure refrigerant discharged to the evaporator after being throttled and depressurized by the expansion valve. The refrigerant enters the annular channel formed by the inner wall of the valve body and the outer wall of the U-shaped adjusting nut through the first port, then enters the lower cavity of the adjusting nut through the flow hole, and then enters the upper cavity through the collection hole in the center of the support seat.

5. The thermal expansion valve according to claim 1, characterized in that: The flow area of ​​the manifold orifice should be at least three times the maximum flow area of ​​the valve port.

6. The thermal expansion valve according to claim 5, characterized in that: The flow area of ​​the manifold is at most 6 times the maximum flow area of ​​the valve port.

7. The thermal expansion valve according to claim 1, characterized in that: The thermal expansion valve also includes a spring adjustment assembly, which includes a second spring, a second spring seat, a push rod, and a second elastic claw. The spring adjustment assembly is installed in the lower cavity of the adjusting nut. The push rod passes through the collection hole and is fixedly connected to the second spring seat. A second elastic claw is assembled between the second spring seat and the second spring.

8. The thermal expansion valve according to claim 7, characterized in that: The support base has a protrusion in the center, and the protrusion has a lateral flow hole that connects to the collection hole. The second spring seat abuts against the protrusion of the support base.

9. The thermal expansion valve according to claim 7, characterized in that: The push rod and the first spring seat maintain a predetermined distance in the installed state.

10. The thermostatic expansion valve according to claim 7, characterized in that: The stiffness of the second spring is at least 1.5 times that of the first spring.

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