Thermostatic expansion valve and method for testing the same

Abstract

The application provides a thermal expansion valve and a testing method thereof. The thermal expansion valve comprises a valve body, a push rod, a valve core, an electromagnetic control mechanism, a coil and a power head mounted on the top of the valve body. The electromagnetic control mechanism is mounted on a control channel through a sleeve seat. The sleeve seat controls the opening and closing of a control valve port. The sleeve seat is in a cylindrical shape. The outer diameter of the sleeve seat is larger than that of the sleeve. The sleeve seat is matched with the control channel. The coil is fixed on the valve body through a screw and is pressed against the sleeve seat. The assembly of the electromagnetic control mechanism, the coil and the valve body can be completed through only one assembly process, thereby reducing the production cost.

Description

Technical Field

[0001] This invention relates to the field of refrigeration and air conditioning, and in particular to a thermostatic expansion valve and its testing method. 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] Thermostatic expansion valves only regulate refrigerant pressure and flow. When the system suddenly stops or loses power, the refrigerant in the system continues to flow into the evaporator through the expansion valve due to the pressure difference, causing the liquid level to be too high. Upon restarting, this can cause liquid slugging in the compressor and damage the system. Electromagnetic thermostatic expansion valves can automatically cut off refrigerant flow during shutdown or power failure, providing protection for the refrigeration system. Existing thermostatic expansion valves, such as those disclosed in Chinese patent applications 201720992385.3 and 201720992449.X, each disclose an electromagnetic expansion valve, including a valve body with a solenoid valve fixed to it. The electromagnetic control mechanism of the solenoid valve is connected to the valve body via a threaded connection, and the coil is fixed to the electromagnetic control mechanism of the solenoid valve by a flexible clip.

[0004] However, during assembly, the electromagnetic control mechanism and the valve body are first connected by threads, and then the coil is fixed to the electromagnetic control mechanism of the solenoid valve by elastic clips. The solenoid valve undergoes two assembly processes, resulting in relatively high production costs. Summary of the Invention

[0005] The purpose of this invention is to provide a thermostatic expansion valve that can reduce production costs.

[0006] To address the aforementioned technical problems, as one aspect of the present invention, a thermostatic expansion valve is provided, comprising a valve body, a push rod, a valve core, an electromagnetic control mechanism, a coil, and a power head mounted on the top of the valve body. The power head includes an upper cover and a lower cover fixed together, with a diaphragm fixed between the upper and lower covers, which is adaptable to changes in refrigerant temperature and pressure from the evaporator. The side of the valve body has a first interface for high-temperature, high-pressure liquid refrigerant introduced from the receiver side, and a second interface for low-temperature, low-pressure refrigerant discharged to the evaporator after being throttled and depressurized by the expansion valve. The refrigerant passage connecting the first and second interfaces is defined as a first channel, with a valve core disposed in the middle therein, allowing refrigerant to be introduced from the first interface... The refrigerant expands into a mist at the valve section and flows to the evaporator through the second interface; a circular control channel with its centerline perpendicular to the valve body end face is also provided between the second interface and the first channel; the electromagnetic control mechanism includes a sleeve seat, which is installed in the control channel through the sleeve seat to control the opening and closing of the control valve port therein. The centerline of the control valve port is perpendicular to the valve body end face, and the control valve port is connected to the second interface. The oblique channel is connected to the first channel and the control channel. The sleeve seat is cylindrical in shape, and its outer diameter is larger than that of the sleeve. The sleeve seat cooperates with the control channel, and the coil is fixed to the valve body by screws and presses the sleeve seat.

[0007] Furthermore, a first annular groove is provided on the outer side of the sleeve seat, and a sealing ring is installed in the first annular groove.

[0008] Furthermore, a second annular groove is provided on the inner sidewall of the control channel, and a sealing ring is installed in the second annular groove.

[0009] Furthermore, the upper end face of the sleeve seat is higher than the end face of the valve body.

[0010] Furthermore, the lower end face of the sleeve seat abuts against the bottom surface of the control channel.

[0011] Furthermore, a third annular groove is formed between the outer side of the lower end of the sleeve seat and the bottom surface of the control channel, and a sealing ring is installed in the third annular groove.

[0012] Furthermore, a baffle is provided at the lower end of the sleeve seat.

[0013] Furthermore, the control valve port protrudes from the bottom surface of the control channel, and the baffle cooperates with the outer wall of the control valve port.

[0014] Furthermore, the baffle covers at least 1 / 4 of the circumference of the annular channel outside the control valve port.

[0015] On the other hand, the present invention provides a test method for a thermal expansion valve, which uses a linear motor to press the electromagnetic control mechanism, eliminating the need for screw tightening. After the test is passed, the coil is assembled and fixed to the valve body with screws to press the sleeve seat, thus reducing assembly steps.

[0016] This invention provides a thermostatic expansion valve and its testing method, comprising a valve body, a push rod, a valve core, an electromagnetic control mechanism, a coil, and a power head mounted on the top of the valve body. The electromagnetic control mechanism is mounted on a control channel via a sleeve seat, controlling the opening and closing of the control valve port therein. The sleeve seat is cylindrical in shape, with an outer diameter larger than that of the sleeve. The sleeve seat mates with the control channel. The coil is fixed to the valve body with screws, pressing it against the sleeve seat. Assembly of the electromagnetic control mechanism, coil, and valve body requires only one assembly step, reducing production costs. Attached Figure Description

[0017] Figure 1 A three-dimensional structural schematic diagram of the thermal expansion valve according to an embodiment of the present invention is shown;

[0018] Figure 2 A cross-sectional view of the thermal expansion valve according to an embodiment of the present invention is shown;

[0019] Figure 3 A partial cross-sectional view of the thermal expansion valve according to an embodiment of the present invention is shown.

[0020] Figure 4 A schematic diagram of the valve body structure according to an embodiment of the present invention is shown;

[0021] Figure 5 A schematic diagram of the second annular groove structure of the thermostatic expansion valve according to an embodiment of the present invention is shown;

[0022] Figure 6 A schematic diagram of the third annular groove structure of the thermostatic expansion valve according to an embodiment of the present invention is shown.

[0023] The attached figures are labeled as follows: Valve body 1, Control channel 101, Control valve port 102, Inclined channel 103, First channel 104, Valve body end face 105, Second annular groove 106, Third annular groove 107, Annular channel 108, Closed refrigerant channel 1081, First interface 11, Second interface 12, Third interface 13, Fourth interface 14, Push rod 2, Valve core 3, Screw 4, Power head 5, Upper cover 51, Lower cover 52, Diaphragm 53, Push block 54, End cap 55, Electromagnetic control mechanism 6, Sleeve 61, Armature 62, Sleeve seat 63, First annular groove 631, Stationary iron core 64, Valve core seat assembly 65, Baffle 66, Return spring 67, Valve needle spring 671, Compression spring 672, Stop block 68, Pin 69, Coil 7, Adjustment mechanism 8, Spring seat 81, Spring 82, Adjusting nut 83. Detailed Implementation

[0024] 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.

[0025] According to a first embodiment of the present invention, reference is made to Figure 1 , 2 3, 4. The thermal expansion valve includes a valve body 1, a push rod 2, a valve core 3, a power head 5, an electromagnetic control mechanism 6, a coil 7, and an adjustment mechanism 8. The adjustment mechanism includes a spring seat 81, a spring 82, and an adjusting nut 83.

[0026] 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.

[0027] The power head 5 is fixed to the top of the valve body 1. The spring seat abuts against the valve core. One end of the spring abuts against the spring seat, and the other end abuts against the adjusting nut. The adjusting nut 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 spring seat. 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 and fixed. 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 valve body 1 also has a hollow cylindrical mounting hole at the top. 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.

[0028] 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 port 11 for introducing high-temperature and high-pressure liquid refrigerant from the liquid receiver side, and a second port 12 for discharging low-temperature and low-pressure refrigerant to the evaporator after being throttled and depressurized by the expansion valve. In addition, on the side of the valve body 1, there is a third port 13 for introducing refrigerant after evaporation in the evaporator, and a fourth port 14 for discharging refrigerant to the compressor side. The first interface 11 and the second interface 12 are both horizontally extending through holes that are roughly cylindrical, respectively located on opposite sides of the lower part of the valve body 1. The refrigerant passage connecting the first interface 11 and the second interface 12 is defined as the first channel 104, in which a valve core is provided, so that the refrigerant introduced from the first interface 11 is throttled and expanded into a mist at the valve section, and flows to the evaporator through the second interface 12. A circular control channel 101 with its center line perpendicular to the end face of the valve body is also provided between the second interface and the first channel. The electromagnetic control mechanism 6 includes a sleeve seat 63, which is installed in the control channel through the sleeve seat to control the opening and closing of the control valve port 102 therein. The center line of the control valve port 102 is perpendicular to the end face of the valve body. The control valve port 102 is connected to the second interface 12. The oblique channel 103 connects the first channel 104 and the control channel 101. The sleeve seat is cylindrical in shape, and the outer diameter of the sleeve seat is larger than that of the sleeve 61. The sleeve seat 63 is fitted with the control channel. The coil 7 is fixed to the valve body by screws 4 and presses the sleeve seat 63. In addition, a second channel, consisting of the third interface 13, the fourth interface 14, and the refrigerant passage connecting them, 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. The adjusting mechanism 8 is fixed to the inner cavity at the bottom of the valve body 1. The spring seat 81 abuts against the valve core 3, and one end of the spring 82 abuts against the spring seat 81, while the other end abuts against the adjusting nut 83.

[0029] In this embodiment, the electromagnetic control mechanism 6 includes a sleeve 61 and an armature 62 that moves up and down at the top of the sleeve. A sleeve seat 63 is fixed to the outer bottom of the sleeve 61, and a stationary iron core 64 is fixed to the inner bottom of the sleeve 61. A valve core seat assembly 65 is inserted into the sleeve seat 63, and a baffle 66 is fixed to the bottom of the sleeve seat 63. A return spring 67 is installed between the valve core seat assembly 65 and the baffle 66. A guide hole and a balance hole are opened on the valve core seat assembly. A stepped hole is opened in the armature 62, and a stop block 68 is fixed to the outer end of the hole. A pin 69 is inserted into the hole. The pin is used to block the guide hole. A valve needle spring 671 is installed between the top of the pin and the stop block 68. A compression spring 672 is installed between the stationary iron core 64 and the armature 62. The sleeve seat 63 is fixed on the valve body 1 and the valve core seat assembly is used to open and close the valve port.

[0030] In this embodiment, the coil 7 is fitted onto the sleeve 61, and the coil 7 is fixed to the valve body 1 by the screw 4 and presses against the sleeve seat 63. The lower end face of the sleeve seat abuts against the bottom surface of the control channel, and the upper end face of the sleeve seat is higher than the end face of the valve body 105. The coil 7 is fixed to the valve body by the screw, and the coil 7 is positioned by the upper end face of the sleeve seat, thereby pressing against the sleeve seat.

[0031] In the background technology, thermal expansion valves have a blind hole for inserting a tooling insert when tightening the electromagnetic control mechanism on the end face of the sleeve seat. The sleeve seat also has a stepped portion with a radial diameter larger than its thread diameter, and the stepped portion presses against the sealing ring, resulting in relatively high processing costs. In this invention, the sleeve seat cooperates with the control channel, and the coil is fixed to the valve body with screws and presses against the sleeve seat. During assembly, the electromagnetic control mechanism, coil, and valve body only require one assembly step, reducing production costs.

[0032] In this embodiment, a first annular groove 631 is provided on the outer side of the sleeve seat 63, and a sealing ring is installed in the first annular groove. Correspondingly, a second annular groove 106 can also be provided on the inner sidewall of the control channel, and a sealing ring can be installed in the second annular groove. This can reduce the diameter of the sleeve seat and save materials. See [reference needed]. Figure 5 Alternatively, a third annular groove 107 can be formed between the outer side of the lower end of the sleeve seat and the bottom surface of the control channel. A sealing ring can be installed in the third annular groove, which can reduce the difficulty of machining the annular groove. See [link to documentation]. Figure 6 .

[0033] The thermal expansion valve in this embodiment is in the open state when not powered and in the closed state when powered. Of course, it can also be used in the closed state when not powered and the open state when powered.

[0034] In this embodiment, the thermal expansion valve is open when not energized and closed when energized. However, the oblique channel 103 connects the first channel 104 and the control channel 101. If the oblique channel is directly opposite the valve core seat assembly, when the valve core seat assembly 65 is closed when energized, the refrigerant will directly impact the valve core seat assembly, causing vibration and noise. To prevent the refrigerant from directly impacting the valve core seat assembly, a baffle 66 is provided at the lower end of the sleeve seat to block the refrigerant from directly impacting the valve core seat assembly. In this embodiment, the control valve port 102 protrudes from the bottom surface of the control channel. The baffle 66 cooperates with the outer wall of the control valve port 102 to form a top-closed refrigerant channel 1081. The baffle 66 covers at least 1 / 4 of the circumference of the outer annular channel 108 of the control valve port. The refrigerant passes through the blocked channel before reaching the valve core seat assembly, reducing the direct impact force and preventing vibration and noise. To accurately block the oblique channel, the electromagnetic control mechanism should mark the middle position of the baffle so that the middle position of the baffle is aligned with the oblique channel.

[0035] When performing vacuum helium testing on a thermostatic expansion valve, a coil is generally not installed to facilitate the replacement of defective electromagnetic control mechanisms and prevent coil interference with the helium testing equipment. However, in this design, without a coil, the electromagnetic control mechanism must be fixed with screws. After passing the test, the screws must be removed and the coil installed, which is not conducive to rapid assembly. Therefore, to prevent coil interference with test results, a linear motor is used to press the electromagnetic control mechanism, eliminating the need for screw tightening. After passing the test, the coil is installed and fixed to the valve body with screws, and the sleeve seat is tightened, reducing assembly steps.

[0036] 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 electromagnetic control mechanism, a coil, and a power head mounted on the top of the valve body. The power head includes an upper cover and a lower cover fixed together, with a diaphragm fixed between the upper and lower covers that can adapt to changes in refrigerant temperature and pressure from the evaporator. The valve body has a first interface on its side for high-temperature, high-pressure liquid refrigerant introduced from the receiver side, and a second interface for low-temperature, low-pressure refrigerant discharged to the evaporator after being throttled and depressurized by the expansion valve. A refrigerant channel connecting the first and second interfaces is defined as a first channel, in which a valve core is provided, causing the refrigerant introduced from the first interface to expand into a mist at the valve section and flow to the evaporator via the second interface. A circular control channel with its centerline perpendicular to the valve body end face is also provided between the second interface and the first channel. The electromagnetic control mechanism includes a sleeve seat, and the electromagnetic control mechanism is mounted on the control channel through the sleeve seat to control the opening and closing of a control valve port therein. The centerline of the control valve port is perpendicular to the valve body end face, and the control valve port connects to the second interface. An oblique channel connects the first channel and the control channel. The valve body is characterized by: The sleeve seat is cylindrical in shape, with an outer diameter larger than that of the sleeve. The sleeve seat mates with the control channel. The coil is fixed to the valve body by screws and presses against the sleeve seat. A baffle is provided at the lower end of the sleeve seat. The control valve port protrudes from the bottom surface of the control channel. The baffle mates with the outer wall of the control valve port. The baffle covers at least 1 / 4 of the circumference of the annular channel on the outer side of the control valve port.

2. The thermostatic expansion valve according to claim 1, characterized in that: A first annular groove is provided on the outer side of the sleeve seat, and a sealing ring is installed in the first annular groove.

3. The thermostatic expansion valve according to claim 1, characterized in that: The inner wall of the control channel is provided with a second annular groove, and a sealing ring is installed in the second annular groove.

4. The thermostatic expansion valve according to claim 1, characterized in that: The upper end face of the sleeve seat is higher than the end face of the valve body.

5. The thermostatic expansion valve according to claim 1, characterized in that: The lower end face of the sleeve seat abuts against the bottom surface of the control channel.

6. The thermostatic expansion valve according to claim 5, characterized in that: The lower outer side of the sleeve seat forms a third annular groove with the bottom surface of the control channel, and a sealing ring is installed in the third annular groove.

7. The test method for the thermostatic expansion valve according to any one of claims 1 to 6, characterized in that: The electromagnetic control mechanism is pressed by a linear motor. After passing the test, the coil is assembled and fixed to the valve body with screws to press the sleeve seat.

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