A built-in open self-balancing expansion valve

Abstract

The present invention provides a built-in open self-balancing expansion valve, which belongs to the technical field of air-conditioning components. It solves the problem of low stability and service life of existing expansion valves due to the defrosting function. The built-in open self-balancing expansion valve includes a valve body and a valve core. Two throttling bodies are also fixed in the valve body. Both throttling bodies have through holes. The through hole walls are circumferentially provided with throttling rings. The valve core is located between the two throttling bodies, and both ends of the valve core have plug connectors. Reset springs are provided between both ends of the valve core and the two throttling bodies. Under the action of the two reset springs, the two plug connectors are respectively moved away from the relative throttling rings. When the valve core moves to either end and compresses the reset spring, the plug connector at that end can be inserted into the relative throttling ring, and a throttling channel is formed between the two ends to adjust the flow rate by the movement of the valve core. The built-in open self-balancing expansion valve has high stability and service life while realizing the defrosting function.

Description

Technical Field

[0001] The invention belongs to the technical field of air-conditioning components and relates to a built-in open self-balancing expansion valve. Background Art

[0002] The compressor, condenser, expansion valve and evaporator together make up the refrigeration system. The expansion valve is an important component in the refrigeration system and is generally installed between the condenser and the evaporator. The expansion valve can make the gas evaporated by the evaporator be pressurized and liquefied into a high-temperature and high-pressure liquid refrigerant through the compressor, and throttled through its throttle port to become a low-temperature and low-pressure mist liquid refrigerant. The refrigerant then absorbs heat in the evaporator to achieve a cooling effect.

[0003] As disclosed in the patent application (application number: 201711366377.9), the expansion valve includes a valve core 1 and a cylindrical valve core 2. The valve core 1 has a through throttling hole, and the end face of the valve core 2 has a cylindrical plug connector that can be inserted into the throttling hole. The outer diameter of the plug connector is smaller than the outer diameter of the valve core 2. The inner wall of the throttling hole has at least two straight cylindrical surfaces of different diameters from the orifice to the inside, and the outer wall of the plug connector has at least two annular throttling walls of different diameters. When the plug connector is inserted into the throttling hole, the throttling wall can be opposite to the straight cylindrical surface and form a throttling channel. During heating, the refrigerant pushes the valve core 1 to compress the spring 1 to achieve three-stage heating flow control. During cooling, the refrigerant pushes the valve core 2 to compress the spring 2 to achieve three-stage cooling flow control.

[0004] The above structure can achieve a certain degree of flow regulation, but the indoor heating process is actually the outdoor cooling process, especially in the northern areas with lower temperatures. Frost will appear on the outdoor unit before the air conditioner is started. When it is just started, the pressure difference at both ends of the valve body is small, and the refrigerant is difficult to push the valve core to flow back for outdoor heating and defrosting. In the normal indoor heating process, the outdoor unit also needs to be defrosted regularly. When the unit is stopped for defrosting, the pressure difference at both ends of the valve body will also decrease rapidly, and valve core 1 and valve core 2 will be blocked, resulting in insufficient refrigerant and difficulty in defrosting.

[0005] In response to the above-mentioned problem of difficulty in defrosting of the mechanical expansion valve, the patent document (application number: 202111426601.5) discloses an expansion valve, including a main valve body and a defrost valve body. The two end ports of the defrost valve body are connected to the main valve body. A valve core assembly is provided in the main valve body between the two end ports of the defrost valve body. The defrost valve body is provided with two limiting parts, and the two limiting parts have flow holes arranged along the length direction of the defrost valve body. A defrost valve core that can slide and block the flow hole is provided between the two limiting parts, and an auxiliary spring is provided between the defrost valve core and the two limiting parts, and under the action of the auxiliary spring, the defrost valve core can move with the two limiting parts. Phase separation, the starting elastic force of the main spring is greater than the elastic force value of the auxiliary spring when it is compressed to the defrost valve core blocking the flow hole, wherein the valve core assembly in the main valve body is in a normally closed type, which is used for flow regulation when the air conditioner is set to normal cooling or heating, and an auxiliary valve body is independently set outside the main valve body for defrosting. However, this structure requires the auxiliary valve body to be welded to the side of the main valve body. The main valve body and the auxiliary valve body are difficult to be made into an integrated body, resulting in corrosion and leakage at the welding points during long-term use, and low stability and service life. At the same time, the main valve body and the auxiliary valve body are both made of brass, and adding the auxiliary valve body greatly increases the material cost. Summary of the Invention

[0006] The purpose of the present invention is to address the above-mentioned problems in the existing technology and propose a built-in open self-balancing expansion valve to solve the problems of low stability and service life of the existing expansion valve due to the defrosting function.

[0007] The objectives of the present invention can be achieved through the following technical solutions: a built-in open self-balancing expansion valve, comprising a tubular valve body and a valve core slidably arranged in the valve body, characterized in that two throttling bodies are also fixed in the valve body, and both of the throttling bodies have a through hole arranged along the axial direction of the valve body, and a throttling ring is circumferentially provided on the wall of the through hole, and a connected flow channel is provided between the two throttling rings, the valve core is located between the two throttling bodies, and both ends of the valve core have a columnar plug connector protruding toward the relative throttling ring, and reset springs are provided between the two ends of the valve core and the two throttling bodies, and under the action of the two reset springs, the two plug connectors are respectively moved away from the relative throttling rings, and when the valve core moves to any one end and compresses the reset spring, the plug connector at that end can be inserted into the relative throttling ring, and a throttling channel is formed between the two to adjust the flow rate by moving the valve core.

[0008] One end of the valve body is the cooling inlet, and the other end is the heating inlet. In the shutdown state, both return springs act on the valve core, so that the valve core is in a central position relative to the two limit bodies, and the plug connectors at both ends of the valve core are away from their respective relative throttling rings. The cooling inlet is connected to the heating inlet through the through holes of the two throttling bodies and the flow channel, that is, it is in a normally open state in the shutdown state. Therefore, when the outdoor unit is defrosted before the air-conditioning equipment is started or the indoor heating is stopped in stages to defrost the outdoor unit, a smaller flow of refrigerant enters from the cooling inlet, and the smaller pressure difference allows the refrigerant to pass through without pushing the valve core and flow out from the heating inlet to perform heating and defrosting of the outdoor unit.

[0009] After the outdoor unit defrosts and the indoor unit begins heating normally, the pressure differential across the valve body is large. Refrigerant flows in from the heating inlet, and the flow channel is insufficient to accommodate the refrigerant's passage. Under this large pressure differential, the refrigerant pushes the valve core toward the cooling inlet, gradually approaching and inserting the plug toward the cooling inlet. As the plug and the throttle ring approach, the passage area between them further decreases, accelerating the plug's insertion into the throttle ring. This creates a throttling channel between the plug's outer circumference and the throttle ring's inner circumference. In different heating modes, such as intermediate heating, rated heating, or maximum heating, the pressure differential across the valve body varies, pushing the valve core to compress the return spring to varying degrees, creating throttling channels of varying flow areas between the plug and the throttle ring to regulate flow. During indoor cooling, refrigerant flows in from the cooling inlet and pushes the valve core toward the heating inlet, similarly forming a throttling channel.

[0010] This application utilizes the large difference between the pressure difference during defrosting and the pressure difference during normal operation, thereby setting the valve core used to regulate the refrigerant flow during normal cooling or heating to a normally open state, allowing the refrigerant with a smaller pressure difference to pass through during defrosting, and the larger pressure difference during normal operation pushes the valve core to form a throttling channel, so that the same valve body and valve core are suitable for both defrosting needs and flow regulation needs during normal operation. There is no need to set up another valve body outside the valve body, thereby reducing costs. The integral valve body can also avoid leakage due to corrosion at the welding points, thereby improving stability and service life.

[0011] In the aforementioned internally open self-balancing expansion valve, the two ends of the flow passage are connected to two through-holes, respectively. The minimum cross-sectional area of ​​the flow passage is smaller than the cross-sectional area of ​​the throttle ring. During normal cooling or heating, the refrigerant first passes through the throttle ring at one end and then through the flow passage. As a result, the minimum cross-sectional area of ​​the flow passage is smaller than the cross-sectional area of ​​the throttle ring, making it difficult for the flow passage to meet flow requirements. The refrigerant can then push the valve core to move, allowing the plug connector to insert into the throttle ring, forming a throttle passage.

[0012] In the aforementioned internally opening self-balancing expansion valve, the section of the through hole near the valve core serves as a guide hole section. The valve core has cylindrical guide portions at both ends. The two guide portions are slidably inserted into the guide hole sections of the two through holes, respectively, with the outer circumferences of the guide portions slidingly engaging with the walls of the guide hole sections. The plug connector is located on the end faces of the guide portions. The plug connector is inserted into the throttle hole, and the gap between the outer circumference of the plug connector and the inner circumference of the throttle ring forms a throttling channel. This gap is small and needs to change under different operating conditions, thus requiring high stability during the movement of the plug connector. To this end, guide portions are provided at both ends of the valve core to slide and guide with the guide hole sections, thereby ensuring high stability of the plug connector.

[0013] In the above-mentioned built-in open self-balancing expansion valve, a spacer is fixed between the two throttling bodies along the axial direction of the valve body, the valve core is slidably arranged in the spacer, the outer diameter of the spacer is smaller than the inner diameter of the valve body, and the flow passage includes a flow gap between the outer peripheral surface of the spacer and the peripheral surface of the valve body, and a flow hole radially extending through the throttling body, one end of the flow hole is connected to the flow gap, and the other end is connected to the guide hole section of the through hole. The inner side of the spacer is used to set the valve core and provide guidance for the movement of the valve core, so that the valve core remains stable. The flow gap on the outer side of the spacer forms a flow passage for the passage of refrigerant, so that the valve core is in a normally open state when the machine is shut down. The refrigerant can enter from the refrigeration inlet, pass through the through hole and flow hole on one throttling body, the flow gap, the flow hole and through hole on the other throttling body, and then flow out from the heating inlet to achieve the defrost function.

[0014] In the aforementioned internally opened self-balancing expansion valve, a balancing hole is provided in the axial center of the spacer. Refrigerant partially enters the spacer cavity, causing pressure imbalance and impaired valve core movement. To address this issue, a balancing hole is provided in the spacer. This hole connects the flow clearance between the spacer and the valve body to the spacer cavity. While the hole is blocked by the valve core, it provides sufficient pressure relief for the spacer cavity, balancing the pressure inside and outside the spacer and ensuring smoother valve core movement.

[0015] In the aforementioned built-in, open-type, self-balancing expansion valve, the valve core is cylindrical, with an outer diameter smaller than the inner diameter of the valve body. A guide ring is circumferentially provided on the outer wall of the valve core. The outer circumferential surface of the guide ring slides in engagement with the inner circumferential surface of the valve body. The flow passage comprises a flow groove axially extending through the outer circumferential surface of the guide ring, a cavity between the outer circumferential surface of the valve core and the inner circumferential surface of the valve body, and a flow hole radially extending through the throttle body. The inner end of the flow hole communicates with the guide hole section of the through-hole. The valve core slides and guides with the valve body via the guide ring to ensure its stability. A flow groove is provided on the guide ring, connecting the inner cavities of the valve body on both sides of the guide ring for passage of refrigerant.

[0016] In the aforementioned built-in opening self-balancing expansion valve, the outer circumference of the plug connector has several annular throttling surfaces of varying outer diameters along the axial direction. These throttling surfaces are arranged in ascending order of diameter along the plug connector's insertion direction. The inner circumference of the throttling ring is an annular mating surface. When the plug connector is inserted into the throttling ring, a throttling channel is formed between the mating surface and the opposing throttling surface. The two plug connectors are used for flow regulation during cooling and heating, respectively. Each plug connector has three throttling surfaces. The throttling surfaces on one plug connector are arranged, in descending order of outer diameter, as an intermediate cooling throttling surface, a rated cooling throttling surface, and a maximum cooling throttling surface. The throttling surfaces on the other plug connector are arranged, in descending order of outer diameter, as an intermediate heating throttling surface, a rated heating throttling surface, and a maximum heating throttling surface.

[0017] In the above-mentioned built-in open self-balancing expansion valve, the through-hole wall of the throttling body is also circumferentially provided with an annular flow-stabilizing ring, which is located between the valve core and the throttling ring, and the flow-stabilizing ring and the throttling ring are fitted together to form a whole, the aperture of the flow-stabilizing ring is larger than the aperture of the throttling ring, and the outer circumferential surface of the plug joint is also circumferentially provided with a resistance ring, which is located between the throttling surface with the smallest outer diameter and the valve core, and the outer diameter of the resistance ring is smaller than the inner diameter of the flow-stabilizing ring, under the action of the two reset springs, the ends of the two plug joints are respectively plugged into the two flow-stabilizing rings, and a flow-stabilizing gap is formed between the outer circumferential surface of the plug joint and the inner circumferential surface of the flow-stabilizing ring, and when the plug joint is inserted into the throttling ring, the resistance ring can enter the flow-stabilizing ring. The end of the plug connector is pre-inserted into the flow stabilizing ring. The plug connector can guide the refrigerant into the flow stabilizing ring in the initial stage. The inner hole of the flow stabilizing ring plays a role of gathering flow, making the flow of refrigerant more stable. At the same time, the cross-sectional area of ​​the flow passage is quite different from the cross-sectional area of ​​the throttling channel formed when the plug connector is inserted into the throttling ring, resulting in excessive changes in the movement speed of the valve core. For this reason, a flow stabilizing ring with an inner diameter larger than the throttling ring is set to play a transition role, so that the movement speed of the valve core is relatively stable. When the plug connector is inserted into the throttling ring, the gap between the plug connector and the flow stabilizing ring is large. For this reason, a resistance ring is set. After the resistance ring enters the flow stabilizing ring, the gap between the two can be reduced, thereby increasing the thrust on the valve core. In actual production, resistance rings can be set on the plug connectors at both ends of the valve core, or on one of the plug connectors, such as setting a resistance ring on the plug connector facing the heating inlet, so that it can play its role in the refrigeration process.

[0018] In the above-mentioned built-in open self-balancing expansion valve, limit posts are slidably provided at both ends of the valve body. The above-mentioned throttling ring is located between the valve core and the limit posts. A limit spring 1 is also provided between the limit post and the valve body. When the plug connector is inserted into the throttling hole, the end of the plug connector can abut against the end of the limit post, and the plug connector can push the limit post to move and compress the limit spring 1. The valve core moves so that the plug connector is inserted into the throttling ring and forms a throttling channel. The plug connector needs to move to different positions and stay there to adjust the flow rate. The reset spring has difficulty maintaining the position of the valve core. For this purpose, a limit post and a limit spring 1 are provided. The limit post can limit the plug connector so that it remains stable at a certain flow level, thereby realizing three flow level cooling modes and three flow level heating modes. The three flow level cooling modes are specifically as follows:

[0019] Intermediate cooling mode: the valve core moves toward the heating inlet, the plug connector contacts the limit post, and the limit spring is not compressed;

[0020] Rated cooling mode: The plug connector pushes the limit post, and the limit spring is partially compressed;

[0021] Maximum cooling mode: The plug connector pushes the limit post further until the limit post is restrained and cannot move further;

[0022] The heating mode of the three flow levels is the reverse movement of the valve core, and the specific process is similar to the cooling process.

[0023] In the aforementioned built-in opening self-balancing expansion valve, a section of the through hole distal to the valve core serves as a mounting hole section. The limiting post is slidably disposed within the mounting hole section, with the outer circumferential surface of the limiting post slidingly engaged with the inner circumferential surface of the mounting hole section. A flow hole is defined in the limiting post, one end of which extends through the end face of the limiting post distal to the valve core, and the other end communicates with the inner hole of the throttle ring. The limiting post is directly guided by the guide hole section of the throttle body, i.e., both the guide portion of the valve core and the limiting post are guided by the same throttle body. This improves the positional accuracy between the plug connector and the limiting post, thereby enhancing stability.

[0024] In the above-mentioned built-in open self-balancing expansion valve, both ends of the valve body are provided with a cylindrical spring seat and a limit seat, the limit seat is fixed in the valve body, the spring seat is slidingly arranged between the throttling body and the limit seat, the limit spring 1 is arranged between the limit column and the spring seat, and a limit spring 2 is also provided between the spring seat and the limit seat, the spring coefficient of the limit spring 1 is smaller than the spring coefficient of the limit spring 2, and the starting elastic force value of the limit spring 2 is greater than the elastic force value when the limit spring 1 is compressed to the limit column and the spring seat. This structure is suitable for forming five flow levels of cooling mode and five flow levels of heating mode. Accordingly, there are five throttling surfaces on the outer peripheral surface of the plug connector. The throttling surfaces of one plug connector are, in descending order of outer diameter, a 1 / 4 cooling throttling surface, an intermediate cooling throttling surface, a rated cooling throttling surface, a maximum cooling throttling surface, and an extra-large cooling throttling surface. The throttling surfaces of the other plug connector are, in descending order of outer diameter, a 1 / 4 heating throttling surface, an intermediate heating throttling surface, a rated heating throttling surface, a maximum heating throttling surface, and an extra-large heating throttling surface. Through the cooperation of the first limit spring and the second limit spring, the five flow levels of cooling mode and the five flow levels of heating mode are realized. The five flow levels of cooling mode are specifically as follows:

[0025] 1 / 4 cooling mode: the valve core moves toward the heating inlet, the plug connector contacts the limit post, and the limit spring is not compressed or partially compressed;

[0026] Intermediate cooling mode: The valve core continues to move so that the plug connector pushes the limit post. The limit spring 1 is compressed until the limit post and the spring seat abut against each other, and the limit spring 2 is not compressed.

[0027] Rated cooling mode: The valve core continues to move so that the plug connector pushes the limit post, and the spring seat compresses the second part of the limit spring;

[0028] Maximum cooling mode: The valve core continues to move, causing the plug connector to push the limit post and spring seat, and the spring seat further compresses the limit spring 2;

[0029] Super cooling mode: The valve core continues to move, causing the plug connector to push the limit post and spring seat, and the spring seat further compresses the limit spring 2;

[0030] The heating mode with five flow levels is the reverse movement of the valve core, and the specific process is similar to the cooling process.

[0031] Compared with the existing technology, this built-in open self-balancing expansion valve has the following advantages:

[0032] 1. In the shutdown state, both return springs act on the valve core, so that the plug connectors at both ends of the valve core are away from their respective throttle rings, that is, the valve core is in the normally open state in the shutdown state. Therefore, when the outdoor unit is defrosted before the air-conditioning equipment is started or when the indoor unit is shut down for defrosting during the heating process, a smaller flow of refrigerant enters from the cooling inlet. The smaller pressure difference allows the refrigerant to pass through without pushing the valve core and flow out from the heating inlet for heating and defrosting of the outdoor unit.

[0033] 2. After the outdoor unit has defrosted and the indoor unit is heating normally, the refrigerant will push the valve core to slide toward the cooling inlet under the action of a large pressure difference, causing the plug to be inserted into the throttle ring at an accelerated speed, thereby forming a throttling channel between the outer surface of the plug and the inner surface of the throttle ring to adjust the flow, allowing the air-conditioning equipment to achieve working modes with different flow levels.

[0034] 3. Since the valve core used for regulating the refrigerant flow during normal cooling or heating is set to a normally open state, the refrigerant with a smaller pressure difference passes through during defrosting, and the larger pressure difference pushes the valve core to form a throttling channel during normal operation, so that the same valve body and valve core are suitable for both defrosting needs and flow regulation needs during normal operation. There is no need to set up another valve body outside the valve body, which reduces costs. The integral valve body can also avoid leakage due to corrosion of welding points, thereby improving stability and service life.

[0035] 4. Due to the setting of the limit post and the limit spring, the limit post can limit the plug connector so that it remains stable when it is at a certain flow level. Therefore, five flow levels of cooling mode and five flow levels of heating mode can be achieved, and the flow regulation accuracy is higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a structural cross-sectional view of a built-in open self-balancing expansion valve.

[0037] Figure 2 It is a partial structural cross-sectional view when the plug connector is inserted into the throttle hole.

[0038] Figure 3 yes Figure 1 A magnified view of the structure at point A.

[0039] Figure 4 It is a structural cross-sectional view of the built-in open self-balancing expansion valve in Example 2.

[0040] Figure 5 It is a partial structural cross-sectional view of the plug connector when inserted into the throttle hole in the second embodiment.

[0041] Figure 6 It is a structural cross-sectional view of the built-in open self-balancing expansion valve in Example 3.

[0042] Figure 7 yes Figure 6 A magnified view of the structure at point B.

[0043] Figure 8 It is a partial structural sectional view of the valve core in the third embodiment.

[0044] Figure 9 It is a structural cross-sectional view of the built-in open self-balancing expansion valve in the fourth embodiment.

[0045] Figure 10 It is a partial structural cross-sectional view of the plug connector when inserted into the throttle hole in the fourth embodiment.

[0046] Figure 11 It is a structural cross-sectional view of the built-in open self-balancing expansion valve in Example 5.

[0047] Figure 12 It is a structural cross-sectional view of the built-in open self-balancing expansion valve in Example 7.

[0048] In the figure, 1. valve body; 11. cooling inlet; 12. heating inlet; 13. flow channel; 14. limit seat; 15. filter; 2. valve core; 21. guide part; 22. guide ring; 221. flow groove; 23. plug connector; 231. 1 / 4 cooling throttling surface; 232. intermediate cooling throttling surface; 233. rated cooling throttling surface; 234. maximum cooling throttling surface; 235. super large cooling throttling surface; 236. 1 / 4 heating throttling surface; 237. intermediate heating throttling surface; 238. rated heating throttling surface; 239. maximum heating Throttle surface; 230, super-large heating throttle surface; 24, resistance ring; 3, throttle body; 31, through hole; 311, guide hole section; 312, mounting hole section; 313, limit step surface; 32, throttle ring; 321, matching surface; 322, throttle channel; 33, steady flow ring; 331, steady flow gap; 34, flow hole; 4, reset spring; 5, spacer; 51, flow gap; 52, balance hole; 6, limit column; 61, flow hole; 62, limit part; 7, spring seat; 71, abutment part; 8, limit spring 1; 9, limit spring 2. DETAILED DESCRIPTION

[0049] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solutions of the present invention, but the present invention is not limited to these embodiments.

[0050] Example 1:

[0051] like Figure 1As shown, a built-in open self-balancing expansion valve includes a tubular valve body 1, one end of which is a cooling inlet 11 and the other end is a heating inlet 12. A filter screen 15 is fixed to the cooling inlet 11. Two throttling bodies 3 are fixed within the valve body 1. The outer circumference of the throttling body 3 is engaged with the inner circumference of the valve body 1 to form a seal. A through hole 31 is formed in the center of the throttling body 3 along the axial direction of the valve body 1. A throttling ring 32 is circumferentially provided on the wall of the through hole 31. The inner hole of the throttling ring 32 is coaxially arranged with the through hole 31 and the inner hole of the valve body 1. A spacer 5 is also provided within the valve body 1. The ends of the spacer 5 are fixedly mounted on the opposite ends of the two throttling bodies 3. The spacer 5 is coaxial with the valve body 1, and the outer diameter of the spacer 5 is smaller than the inner diameter of the valve body 1. A flow gap 51 is formed between the outer circumference of the spacer 5 and the inner circumference of the valve body 1 to connect the two through holes 31. A cylindrical valve core 2 is slidingly arranged in the spacer sleeve 5. The valve core 2 is axially arranged along the valve core 2, and a guide ring 22 is provided on the circumferential direction of the middle outer peripheral surface of the valve core 2. The outer peripheral surface of the guide ring 22 is slidably guided with the inner peripheral surface of the spacer sleeve 5. The valve core 2 is located between the two throttling bodies 3, and both ends of the valve core 2 have a plug joint 23 that is cylindrical and protrudes toward the opposite throttling ring 32. A return spring 4 is provided between both ends of the valve core 2 and the two throttling bodies 3. One end of the return spring 4 rests on the end face of the throttling body 3, and the other end is sleeved on the valve core 2 and rests on the end face of the guide ring 22. The valve core 2 is an integral type. Of course, in the actual processing process, the valve core 2 can adopt a two-section split type, that is, the valve core 2 is cut off at the middle part of the guide ring 22, but under the action of the two return springs 4, the two valve cores 2 are always resting together. Under the action of the two return springs 4, when the valve core 2 is not subjected to a large pressure difference of the refrigerant, the two plug connectors 23 are respectively away from the relative throttle rings 32. Therefore, when defrosting, a small flow of refrigerant enters from the cooling inlet 11. The small pressure difference does not need to push the valve core 2, so the refrigerant can pass through and flow out from the heating inlet 12 to perform heating and defrosting of the outdoor unit. Figure 2 As shown, when the refrigerant pressure difference is large during normal cooling or heating, the valve core 2 moves to one end and compresses the return spring 4, so that the plug connector 23 at that end can be inserted into the relative throttling ring 32, and a throttling channel 322 is formed between the outer peripheral surface of the plug connector 23 and the inner peripheral surface of the throttling ring 32 to adjust the flow rate by moving the valve core 2.

[0052] Specifically, combined Figure 3As shown, a section of the through hole 31 near the valve core 2 is a guide hole section 311. The mounting hole section 312 is located between the valve core 2 and the throttle ring 32, and the aperture of the throttle ring 32 is smaller than the aperture of the mounting hole section 312. The valve core 2 has columnar guide portions 21 at both ends. The two guide portions 21 are slidably inserted into the guide hole sections 311 of the two through holes 31, respectively. The outer circumference of the guide portion 21 slides with the wall of the guide hole section 311. The plug joint 23 is located on the end surface of the guide portion 21. A flow hole 34 is also radially penetrated through the throttle body 3. The aperture of this flow hole 34 is smaller than that of the throttle ring 32. The inner end of the flow hole 34 is connected to the guide hole section 311, and the outer end is connected to the flow gap 51. That is, the flow gap 51 and the two flow holes 34 form the flow channel 13. The outer circumference of the plug connector 23 has a plurality of annular throttling surfaces with different outer diameters along the axial direction. The throttling surfaces are arranged in order from small to large in diameter along the insertion direction of the plug connector 23. The inner circumference of the throttling ring 32 is an annular mating surface 321. When the plug connector 23 is inserted into the throttling ring 32, a throttling channel 322 is formed between the mating surface 321 and the opposite throttling surface. The two plug connectors 23 are used for flow regulation during cooling and heating respectively. There are three throttling surfaces on each plug connector 23. The throttling surfaces on one of the plug connectors 23 are arranged in order from large to large in diameter. The smaller ones are the intermediate cooling throttling surface 232, the rated cooling throttling surface 233 and the maximum cooling throttling surface 234, which are opposite to the matching surface 321 in sequence to form the intermediate cooling mode, the rated cooling mode and the maximum cooling mode. The throttling surfaces on the other plug connector 23 are, from large to small in outer diameter, the intermediate heating throttling surface 237, the rated heating throttling surface 238 and the maximum heating throttling surface 239, which are opposite to the matching surface 321 of the other throttling ring 32 in sequence to form the intermediate heating mode, the rated heating mode and the maximum heating mode.

[0053] Example 2:

[0054] The structure of the built-in open self-balancing expansion valve is basically the same as that of the first embodiment. Figure 4 、 Figure 5As shown, the through hole 31 of the throttle body 3 also has an annular flow stabilizing ring 33 on its circumferential wall. The flow stabilizing ring 33 is located between the valve core 2 and the throttle ring 32, and the flow stabilizing ring 33 and the throttle ring 32 are fitted together to form a whole. The aperture of the flow stabilizing ring 33 is larger than the aperture of the throttle ring 32. Under the action of the two return springs 4, the ends of the two plug joints 23 are respectively inserted into the two flow stabilizing rings 33, and a flow stabilizing gap 331 is formed between the outer circumference of the plug joint 23 and the inner circumference of the flow stabilizing ring 33. The section of the through hole 31 away from the valve core 2 is the mounting hole section 312, that is, the throttle ring 32 is located between the guide hole section 311 and the mounting hole section 312. The mounting hole section 312 is a stepped hole, so that the aperture of the end of the mounting hole section 312 close to the throttle ring 32 is smaller, and has a limiting step surface 313. The limiting column 6 is slidably inserted in the mounting hole section 312, and the outer circumference of the limiting column 6 is slidably matched with the inner circumference of the mounting hole section 312. An annular limiting portion 62 is provided on the outer circumference of the limiting column 6. A cylindrical spring seat 7 is also fixed at both ends of the valve body 1. The inner wall of the spring seat 7 has an abutment portion 71 circumferentially. A limit spring 1-8 is provided between the limit post 6 and the spring seat 7. One end of the limit spring 1-8 abuts against the end face of the limit post 6, while the other end is inserted into the spring seat 7 and abuts against the abutment portion 71. Under the action of the limit spring 1-8, the limit portion 62 of the limit post 6 abuts against the limit step surface 313 of the mounting hole section 312. At this time, the end of the limit post 6 facing the valve core 2 is opposite the throttle hole. A flow hole 61 is formed in the limit post 6. One end of the flow hole 61 extends to the end face of the limit post 6 away from the valve core 2, and the other end is connected to the inner hole of the throttle ring 32. When the plug connector 23 is inserted into the throttle hole, the end of the plug connector 23 can abut against the end of the limit column 6, and the plug connector 23 can push the limit column 6 to move and compress the limit spring 1 8, so as to realize three flow levels of cooling mode and three flow levels of heating mode, wherein the three flow levels of cooling mode are specifically:

[0055] Intermediate cooling mode: the valve core 2 moves toward the heating inlet 12, the plug connector 23 contacts the limit post 6, and the limit spring 8 is not compressed;

[0056] Rated cooling mode: the plug connector 23 pushes the limit post 6, and the limit spring 8 is partially compressed;

[0057] Maximum cooling mode: the plug connector 23 further pushes the limit post 6 until the limit post 6 abuts against the spring seat 7 and is unable to move further;

[0058] The heating modes of the three flow levels are as follows:

[0059] Intermediate heating mode: the valve core 2 moves toward the cooling inlet 11, the plug connector 23 contacts the limit post 6, and the limit spring 8 is not compressed;

[0060] Rated heating mode: the plug connector 23 pushes the limit post 6, and the limit spring 8 is partially compressed;

[0061] Maximum heating mode: the plug connector 23 further pushes the limiting post 6 until the limiting post 6 and the spring seat 7 are in contact with each other and are difficult to move further.

[0062] Example 3:

[0063] The structure of the built-in open self-balancing expansion valve is basically the same as that of the second embodiment. Figure 6 、 Figure 7 、 Figure 8 As shown, the two spring seats 7 are slidably arranged in the valve body 1, and cylindrical limit seats 14 are fixed at both ends of the valve body 1. The spring seat 7 is located between the limit column 6 and the limit seat 14. A limit spring 2 9 is also provided between the spring seat 7 and the limit seat 14. One end of the limit spring 2 9 abuts on the spring seat 7, and the other end abuts on the limit seat 14. The spring coefficient of the limit spring 1 8 is smaller than the spring coefficient of the limit spring 2 9, and the starting elastic force value of the limit spring 2 9 is greater than the elastic force value when the limit spring 1 8 is compressed to the limit column 6 and the spring seat 7. This structure is suitable for forming a cooling mode with five flow levels and a heating mode with five flow levels. Accordingly, there are five throttling surfaces on the outer peripheral surface of the plug connector 23. The throttling surfaces of one plug connector 23 are, in descending order of outer diameter, a 1 / 4 cooling throttling surface 231, an intermediate cooling throttling surface 232, a rated cooling throttling surface 233, a maximum cooling throttling surface 234 and an extra-large cooling throttling surface 235. The throttling surfaces of the other plug connector 23 are, in descending order of outer diameter, a 1 / 4 heating throttling surface 236, an intermediate heating throttling surface 237, a rated heating throttling surface 238, a maximum The heating throttle surface 239 and the extra-large heating throttle surface 230, and the two plug connectors 23 have a resistance ring 24 circumferentially at the throttle surface with the smallest outer diameter. The resistance ring 24 is located between the throttle surface with the smallest outer diameter and the valve core 2, and the outer diameter of the resistance ring 24 is smaller than the inner diameter of the flow stabilizing ring 33. When the plug connector 23 is inserted into the throttle ring 32 and the maximum cooling throttle surface 234 or the maximum heating throttle surface 239 is opposite to the mating surface 321, the resistance ring 24 can enter the flow stabilizing ring 33. After the resistance ring 24 enters the flow stabilizing ring 33, it can reduce the gap between the two, thereby increasing the thrust on the valve core 2. Through the cooperation of the limit spring 1 8 and the limit spring 2 9, five flow levels of cooling mode and five flow levels of heating mode can be achieved, wherein the five flow levels of cooling mode are specifically as follows:

[0064] 1 / 4 cooling mode: the valve core 2 moves toward the heating inlet 12, the plug connector 23 contacts the limit column 6, and the limit spring 8 is not compressed or partially compressed;

[0065] Intermediate cooling mode: the valve core 2 continues to move so that the plug connector 23 pushes the limit post 6, and the limit spring 1 8 is compressed until the limit post 6 abuts against the spring seat 7, and the limit spring 2 9 is not compressed;

[0066] Rated cooling mode: the valve core 2 continues to move so that the plug connector 23 pushes the limit post 6, and the spring seat 7 compresses a part of the limit spring 2 9;

[0067] Maximum cooling mode: the valve core 2 continues to move so that the plug connector 23 pushes the limit post 6 and the spring seat 7, and the spring seat 7 further compresses the limit spring 2 9;

[0068] Super cooling mode: the valve core 2 continues to move so that the plug connector 23 pushes the limit post 6 and the spring seat 7, and the spring seat 7 further compresses the limit spring 2 9;

[0069] The five flow levels of heating modes are as follows:

[0070] 1 / 4 heating mode: the valve core 2 moves toward the cooling inlet 11, the plug connector 23 contacts the limit post 6, and the limit spring 1 8 is not compressed or partially compressed;

[0071] Intermediate heating mode: the valve core 2 continues to move so that the plug connector 23 pushes the limit post 6, and the limit spring 1 8 is compressed until the limit post 6 and the spring seat 7 abut against each other, and the limit spring 2 9 is not compressed;

[0072] Rated heating mode: the valve core 2 continues to move so that the plug connector 23 pushes the limit post 6, and the spring seat 7 compresses a part of the limit spring 9;

[0073] Maximum heating mode: the valve core 2 continues to move so that the plug connector 23 pushes the limit post 6 and the spring seat 7, and the spring seat 7 further compresses the limit spring 2 9;

[0074] Super large heating mode: the valve core 2 continues to move so that the plug connector 23 pushes the limit column 6 and the spring seat 7, and the spring seat 7 further compresses the limit spring 2 9.

[0075] Example 4:

[0076] The structure of the built-in open self-balancing expansion valve is basically the same as that of the second embodiment. Figure 9 、 Figure 10 As shown, no spacer 5 is provided in the valve body 1, and the outer peripheral surface of the guide ring 22 of the valve core 2 is directly slidably matched with the inner peripheral surface of the valve body 1. The flow channel 13 includes a flow groove 221 axially extending through the outer peripheral surface of the guide ring 22, a cavity between the outer peripheral surface of the valve core 2 and the inner peripheral surface of the valve body 1, and a flow hole 34 radially extending through the throttling body 3. The inner end of the flow hole 34 is connected to the guide hole section 311 of the through hole 31.

[0077] Embodiment 5:

[0078] The structure of the built-in open self-balancing expansion valve is basically the same as that of the fourth embodiment. Figure 11 As shown, the guide ring 22 does not have a flow groove 221, but a gap is set between the outer peripheral surface of the guide ring 22 and the inner peripheral surface of the valve body 1 for the passage of refrigerant, that is, the flow channel 13 includes the gap between the outer peripheral surface of the guide ring 22 and the inner peripheral surface of the valve body 1, the cavity between the outer peripheral surface of the valve core 2 and the inner peripheral surface of the valve body 1, and the flow hole 34 radially penetrating through the throttling body 3, and the inner end of the flow hole 34 is connected to the guide hole section 311 of the through hole 31.

[0079] Example 6:

[0080] The structure of the built-in open self-balancing expansion valve is basically the same as that of the second embodiment, except that throttling surfaces of different diameters are arranged on the inner circumference of the throttling ring 32, and the mating surface 321 is arranged on the outer circumference of the plug connector 23, that is, at least three throttling surfaces are arranged on the inner circumference of the throttling ring 32, and the three throttling surfaces are arranged in order from small to large in diameter along the insertion direction of the plug connector 23, thereby realizing three flow levels of cooling mode and three flow levels of heating mode. Of course, if the number of throttling surfaces is five, five flow levels of cooling mode and five flow levels of heating mode can also be realized.

[0081] Embodiment seven:

[0082] The structure of the built-in open self-balancing expansion valve is basically the same as that of the second embodiment. Figure 12 As shown, a balancing hole 52 is opened in the axial middle part of the spacer 5, and the balancing hole 52 passes through the inner and outer side surfaces of the spacer 5, so that the flow gap 51 is connected with the inner cavity of the spacer 5. The aperture of the balancing hole 52 is smaller than the axial width of the guide ring 22, so that the outer peripheral surface of the guide ring 22 can block the balancing hole 52, but it is sufficient to relieve the pressure in the inner cavity of the spacer 5, so that the pressure inside and outside the spacer 5 is balanced, and the valve core 2 moves more smoothly.

[0083] The specific embodiments described herein are merely illustrative of the spirit of the present invention. Persons skilled in the art may make various modifications, additions, or substitutions to the described specific embodiments without departing from the spirit of the present invention or exceeding the scope of the appended claims.

[0084] Although this document frequently uses terms such as main valve body 1, cooling inlet 11, and heating inlet 12, the use of other terms is not excluded. These terms are used solely to more conveniently describe and explain the essence of the present invention; interpreting them as any additional limitations is contrary to the spirit of the present invention.

Claims

1. A built-in open self-balancing expansion valve, comprising a tubular valve body (1) and a valve core (2) slidably arranged in the valve body (1), characterized in that: Two throttling bodies (3) are also fixed in the valve body (1). Both of the throttling bodies (3) have a through hole (31) extending axially through the valve body (1). A throttling ring (32) is provided on the wall of the through hole (31). A flow passage (13) is provided between the two throttling rings (32). The valve core (2) is located between the two throttling bodies (3). Both ends of the valve core (2) have plug connectors (23) that are columnar and protrude toward the opposite throttling rings (32). Reset springs (4) are provided between the two ends of the valve core (2) and the two throttling bodies (3). Under the action of the two reset springs (4), the two plug connectors (23) are separated. The valve core (2) is provided with a plurality of through holes (31) and a plurality of through holes (31) and a plurality of through holes (31) at the ends of the valve core (2) and the plurality of through holes (31) are provided with a plurality of through holes (31) and a plurality of through holes (31) at the ends of the valve core (2) and the ...

2. The built-in open self-balancing expansion valve according to claim 1, characterized in that: The minimum cross-sectional area of ​​the flow passage (13) is smaller than the cross-sectional area of ​​the throttling ring (32).

3. The built-in open self-balancing expansion valve according to claim 2, characterized in that: The valve core (2) has columnar guide parts (21) at both ends. The two guide parts (21) are respectively slidably inserted into the guide hole sections (311) of the two through holes (31), and the outer peripheral surface of the guide part (21) is slidably matched with the hole wall of the guide hole section (311). The plug connector (23) is located on the end surface of the guide part (21).

4. The built-in open self-balancing expansion valve according to claim 3, characterized in that: A spacer sleeve (5) is fixed between the two throttling bodies (3) along the axial direction of the valve body (1); the valve core (2) is slidably arranged in the spacer sleeve (5); the outer diameter of the spacer sleeve (5) is smaller than the inner diameter of the valve body (1); the flow passage (13) includes a flow gap (51) between the outer peripheral surface of the spacer sleeve (5) and the inner peripheral surface of the valve body (1); and one end of the flow hole (34) is connected to the flow gap (51).

5. The built-in open self-balancing expansion valve according to claim 3, characterized in that: The valve core (2) is cylindrical, and the outer diameter of the valve core (2) is smaller than the inner diameter of the valve body (1). A guide ring (22) is provided on the outer wall of the valve core (2) in the circumferential direction. The outer peripheral surface of the guide ring (22) is slidably matched with the inner peripheral surface of the valve body (1). The flow passage (13) includes a flow groove (221) axially extending through the outer peripheral surface of the guide ring (22) and a cavity between the outer peripheral surface of the valve core (2) and the inner peripheral surface of the valve body (1).

6. The built-in open self-balancing expansion valve according to claim 3 or 4, characterized in that: The outer peripheral surface of the plug connector (23) is provided with a plurality of annular throttling surfaces with different outer diameters in the axial direction, and the throttling surfaces are arranged in order from small to large according to diameter along the insertion direction of the plug connector (23). The inner peripheral surface of the throttling ring (32) is an annular mating surface (321). When the plug connector (23) is inserted into the throttling ring (32), a throttling channel (322) is formed between the mating surface (321) and the opposite throttling surface.

7. The built-in open self-balancing expansion valve according to claim 6, characterized in that: The through hole (31) of the throttle body (3) is also provided with an annular flow stabilizing ring (33) on the circumferential wall. The flow stabilizing ring (33) is located between the valve core (2) and the throttle ring (32). The flow stabilizing ring (33) and the throttle ring (32) are fitted together to form a whole. The aperture of the flow stabilizing ring (33) is larger than the aperture of the throttle ring (32). The outer peripheral surface of the plug connector (23) is also provided with a resistance ring (24) on the circumferential surface. The resistance ring (24) is located at the position with the smallest outer diameter. The throttling surface and the valve core (2) are interposed between the resistance ring (24), and the outer diameter of the resistance ring (24) is smaller than the inner diameter of the flow stabilizing ring (33). Under the action of the two return springs (4), the ends of the two plug connectors (23) are respectively plugged into the two flow stabilizing rings (33), and a flow stabilizing gap (331) is formed between the outer circumference of the plug connector (23) and the inner circumference of the flow stabilizing ring (33). When the plug connector (23) is inserted into the throttling ring (32), the resistance ring (24) can enter the flow stabilizing ring (33).

8. The built-in open self-balancing expansion valve according to any one of claims 1 to 4, characterized in that: Limiting posts (6) are slidably provided at both ends of the valve body (1), the throttling ring (32) is located between the valve core (2) and the limiting post (6), and a limiting spring (8) is also provided between the limiting post (6) and the valve body (1). When the plug connector (23) is inserted into the throttling hole, the end of the plug connector (23) can abut against the end of the limiting post (6), and the plug connector (23) can push the limiting post (6) to move and compress the limiting spring (8).

9. The built-in open self-balancing expansion valve according to claim 8, characterized in that: A section of the through hole (31) away from the valve core (2) is a mounting hole section (312), the limiting column (6) is slidably arranged in the mounting hole section (312), and the outer peripheral surface of the limiting column (6) is slidably matched with the inner peripheral surface of the mounting hole section (312), and a flow hole (61) is opened on the limiting column (6), one end of the flow hole (61) passes through the end surface of the limiting column (6) away from the valve core (2), and the other end is communicated with the inner hole of the throttling ring (32).

10. The built-in open self-balancing expansion valve according to claim 8, characterized in that: Both ends of the valve body (1) are provided with a cylindrical spring seat (7) and a limit seat (14), the limit seat (14) is fixed in the valve body (1), the spring seat (7) is slidably arranged between the throttle body (3) and the limit seat (14), the limit spring 1 (8) is arranged between the limit column (6) and the spring seat (7), and a limit spring 2 (9) is also arranged between the spring seat (7) and the limit seat (14), the spring coefficient of the limit spring 1 (8) is smaller than the spring coefficient of the limit spring 2 (9), and the starting elastic force value of the limit spring 2 (9) is greater than the elastic force value when the limit spring 1 (8) is compressed to the limit column (6) and the spring seat (7) abutting against each other.

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