An electronic expansion valve and its valve needle device

Abstract

The present invention discloses an electronic expansion valve and its valve needle device, wherein the valve needle device includes: a drive rod assembly; a valve needle, which is slidably connected to the drive rod assembly and can rotate relative to the drive rod assembly around its own axis; a sleeve, which is slidably connected to the valve needle; a first elastic member, which is installed between the drive rod assembly and the valve needle; a second elastic member, which is installed between the sleeve and the valve needle; in the valve-open state, the second elastic member supports the drive rod assembly and the valve needle, so that a gap is set between the drive rod assembly and the sleeve; in the valve-closed state, the drive rod assembly overcomes the elastic force of the first elastic member and contacts the sleeve, and overcomes the elastic force of the second elastic member through the sleeve to press the valve needle. The valve needle of the valve needle device provided by the present invention is not easy to rotate relative to the valve port during the valve opening and closing process, which can reduce the risk of wear and internal leakage, and the valve needle is not easy to shake in the valve-open state, which can reduce noise.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic expansion valves, and in particular to an electronic expansion valve and a valve needle device thereof. Background Art

[0002] In the field of air conditioning, the electronic expansion valve used mainly adjusts the flow of refrigerant by opening and closing the valve needle and the valve port. When the electronic expansion valve needs to be fully closed and reset, the valve needle will move toward the valve port and block the valve port.

[0003] However, in traditional electronic expansion valves, in order to ensure a large reverse valve opening pressure difference, a high-rigidity compression spring is often set at the rear end of the valve needle. Its compression force acts directly on the valve needle, which causes the valve needle to rotate synchronously with the screw rod. When the valve needle contacts or separates from the valve port, the relative rotation between the valve needle and the valve port will cause wear on the two, thereby forming internal leakage and affecting the seal. Summary of the Invention

[0004] The object of the present invention is to provide an electronic expansion valve and a valve needle device thereof, wherein the valve needle of the valve needle device is not easy to rotate relative to the valve port during the valve opening and closing process, which can avoid wear between the valve needle and the valve port and the risk of internal leakage caused by this to a large extent, and is conducive to ensuring reliable sealing between the valve needle and the valve port; moreover, the valve needle is not easy to shake in the valve open state, which is conducive to reducing noise.

[0005] The present invention provides a valve needle device of an electronic expansion valve, comprising: a drive rod assembly; a valve needle, which is slidably connected to the drive rod assembly and can rotate around its own axis relative to the drive rod assembly; a sliding sleeve, which is slidably connected to the valve needle; a first elastic member, which is installed between the drive rod assembly and the valve needle; a second elastic member, which is installed between the sliding sleeve and the valve needle; in an open valve state, the second elastic member supports the drive rod assembly and the valve needle, so that a gap is set between the drive rod assembly and the sliding sleeve; in a closed valve state, the drive rod assembly overcomes the elastic force of the first elastic member and contacts the sliding sleeve, and overcomes the elastic force of the second elastic member through the sliding sleeve to press the valve needle.

[0006] With the above structure, in the valve closing state, the drive rod assembly must first overcome the elastic force of the first elastic member so that the drive rod assembly contacts the sleeve, and then overcome the elastic force of the second elastic member through the sleeve to press the valve needle to the valve port, and then the first elastic member and the second elastic member jointly provide a reverse valve opening pressure difference.

[0007] When the valve needs to be opened, the drive rod assembly starts to rotate and moves relatively away from the valve port. At this time, the first elastic member and the second elastic member jointly press the valve needle, and the valve needle is in a stationary state relative to the valve port at the moment the drive rod assembly moves; and as the drive rod assembly moves away, the elastic forces of the first elastic member and the second elastic member can continue to decrease. When the drive rod assembly is disengaged from the sleeve, the second elastic member is basically in a free state. When the drive rod assembly drives the valve needle to the critical point of disengaging from the valve port, only the tiny elastic force of the first elastic member exists. The rotational torque transmitted by the drive rod assembly to the valve needle through the first elastic member is actually very small, making it difficult for the valve needle to rotate in the process of disengaging from the valve port, thereby effectively avoiding wear between the valve needle and the valve port when opening the valve.

[0008] In the valve-open state, there is only a tiny elastic force of the first elastic member between the valve needle and the drive rod assembly, and the valve needle basically does not rotate along with the drive rod assembly.

[0009] When the valve needs to be closed, the valve needle and the drive rod assembly move toward the valve port together. When the valve needle just contacts the valve port, the valve needle is still the same as in the valve open state, and it does not rotate synchronously with the drive rod assembly. The valve needle is in a stationary state relative to the valve port. In this way, wear between the valve needle and the valve port when closing the valve can be effectively avoided.

[0010] That is to say, the valve needle device provided by the present invention has a low possibility of its valve needle rotating relative to the valve port during the process of opening and closing the valve, which can avoid wear between the valve needle and the valve port and the risk of internal leakage caused by it to a large extent, and is conducive to ensuring reliable sealing between the valve needle and the valve port in the closed valve state.

[0011] Moreover, in the valve open state, although there is a gap between the drive rod assembly and the sleeve, there is still a first elastic member between the two for support, and the valve needle is still under pressure in the axial direction, which can largely prevent the valve needle from shaking under the impact of the refrigerant and the noise generated thereby.

[0012] The present invention also provides an electronic expansion valve, comprising a valve body device and a valve needle device, wherein the valve body device is provided with a valve port, and the valve body device is used to adjust the opening of the valve port. The valve body device is the valve needle device of the above-mentioned electronic expansion valve.

[0013] Since the valve body device of the above-mentioned electronic expansion valve has already achieved the above-mentioned technical effects, the electronic expansion valve having the valve body device should also have similar technical effects, and therefore will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a structural schematic diagram of a specific embodiment of the valve needle device of the electronic expansion valve provided by the present invention in the valve open state;

[0015] Figure 2 for Figure 1 Schematic diagram of the structure in the closed valve state.

[0016] Figure 1-2 The reference numerals in the figures are described as follows:

[0017] 1 driving rod assembly, 11 driving rod, 12 driving sleeve, 121 sealing plate, 121a sliding hole;

[0018] 2 valve needle, 21 valve needle head, 211 wing plate, 22 valve needle rod, 221 thick neck, 222 thin neck, 23 limit component;

[0019] 3 sliding sleeve, 31 flange;

[0020] 4 first elastic member;

[0021] 5. Second elastic member;

[0022] 6 transition sets. DETAILED DESCRIPTION

[0023] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0024] The terms "first" and "second" mentioned herein are only used to facilitate description of two or more structures or components with the same or similar structures, and do not imply any special limitation on the order.

[0025] Please refer to Figure 1-2 , Figure 1 This is a structural diagram of a specific embodiment of the valve needle device of the electronic expansion valve provided by the present invention in the valve open state. Figure 2 for Figure 1 Schematic diagram of the structure in the closed valve state.

[0026] like Figure 1 、 Figure 2 As shown, the present invention provides a valve needle device of an electronic expansion valve, comprising: a drive rod assembly 1; a valve needle 2, which is slidably connected to the drive rod assembly 1 and can rotate around its own axis relative to the drive rod assembly 1; a sleeve 3, which is slidably connected to the valve needle 2; a first elastic member 4, which is installed between the drive rod assembly 1 and the valve needle 2; a second elastic member 5, which is installed between the sleeve 3 and the valve needle 2; in the valve open state, the second elastic member 5 supports the drive rod assembly 1 and the valve needle 2, so that a gap is set between the drive rod assembly 1 and the sleeve 3; in the valve closed state, the drive rod assembly 1 overcomes the elastic force of the first elastic member 4 and contacts the sleeve 3, and overcomes the elastic force of the second elastic member 5 through the sleeve 3 to press the valve needle 2 against the valve port of the electronic expansion valve.

[0027] With the above structure, in the valve closing state, the drive rod assembly 1 must first overcome the elastic force of the first elastic member 4 so that the drive rod assembly 1 contacts the sleeve 3, and then overcome the elastic force of the second elastic member 5 through the sleeve 3 to press the valve needle 2 to the valve port, and then the first elastic member 4 and the second elastic member 5 jointly provide the reverse valve opening pressure difference.

[0028] When the valve needs to be opened, the drive rod assembly 1 starts to rotate and moves relatively away from the valve port. At this time, the first elastic member 4 and the second elastic member 5 jointly press the valve needle 2, and the valve needle 2 is in a stationary state relative to the valve port at the moment the drive rod assembly 1 moves; and as the drive rod assembly 1 moves away, the elastic forces of the first elastic member 4 and the second elastic member 5 can continue to decrease. When the drive rod assembly 1 is separated from the sleeve 3, the second elastic member 5 is basically in a free state; when the drive rod assembly 1 drives the valve needle 2 to the critical point of separating from the valve port, only the tiny elastic force of the first elastic member 4 exists, and the rotational torque transmitted by the drive rod assembly 1 to the valve needle 2 through the first elastic member 4 is actually very small, so that the valve needle 2 is not easy to rotate in the process of separating from the valve port, thereby effectively avoiding wear between the valve needle 2 and the valve port when the valve is opened.

[0029] In the valve-open state, there is only a small elastic force of the first elastic member 4 between the valve needle 2 and the driving rod assembly 1 , and the valve needle 2 basically does not rotate with the driving rod assembly 1 .

[0030] When the valve needs to be closed, the valve needle 2 moves toward the valve port together with the drive rod assembly 1. When the valve needle 2 just contacts the valve port, the valve needle 2 is still the same as in the valve open state, and it does not rotate synchronously with the drive rod assembly 1. The valve needle 2 is in a stationary state relative to the valve port. In this way, the wear between the valve needle 2 and the valve port when the valve is closed can be effectively avoided.

[0031] That is to say, the valve needle device provided by the present invention has a valve needle 2 that is less likely to rotate relative to the valve port during the process of opening and closing the valve, which can largely avoid wear between the valve needle 2 and the valve port, and the risk of internal leakage caused by this, and is conducive to ensuring reliable sealing between the valve needle 2 and the valve port in the closed state.

[0032] Moreover, in the valve-open state, although there is a gap between the drive rod assembly 1 and the sleeve 3, there is still a first elastic member 4 between the two for support, and the valve needle 2 is still under pressure in the axial direction, which can largely prevent the valve needle 2 from shaking under the impact of the refrigerant and the noise generated thereby.

[0033] In a specific solution, the drive rod assembly 1 may include a drive rod 11 and a drive sleeve 12. The drive rod 11 may specifically be a screw rod with an external thread on at least a partial section, which can be connected to the electric drive component (usually a motor) in the electronic expansion valve. The structure of this part can refer to the existing technology and will not be described in detail here. Under the action of the electric drive component, the drive rod 11 can rotate and simultaneously perform axial displacement.

[0034] The drive sleeve 12 can be installed at one end of the drive rod 11, and the valve needle 2 can include a valve needle head 21 and a valve needle rod 22. The valve needle rod 22 can be slidably connected to the drive sleeve 12, and a limiting component 23 can be provided between the valve needle rod 22 and the drive sleeve 12. The limiting component 23 can prevent the valve needle 2 from slipping off the drive rod 11.

[0035] In detail, the drive sleeve 12 can be cylindrical, one end of which can be connected to the drive rod 11, specifically by welding, and the other end can be provided with a sealing plate 121, and the sealing plate 121 can be provided with a sliding hole 121a, and the valve needle rod 22 can be slidably inserted into the sliding hole 121a; the limiting component 23 can specifically be a ring-shaped or block-shaped limiting structure, which can be installed on the outer wall of the valve needle rod 22 by interference fitting, welding, etc.

[0036] The needle rod 22 can have an oversized portion. The second elastic member 5 can be a spring, which can be mounted over the needle rod 22. Its ends abut the oversized portion and the sliding sleeve 3, respectively, to accumulate or release elastic force when the sliding sleeve 3 moves relative to the needle 2. In this case, the needle rod 22 can also function as a spring column, limiting and guiding the expansion and contraction of the second elastic member 5, thereby largely preventing radial movement of the second elastic member 5 during expansion and contraction.

[0037] In the first embodiment, the valve needle rod 22 can be a stepped rod. Moving away from the valve needle head 21, the valve needle rod 22 can include a thick neck portion 221 and a thin neck portion 222. The thick neck portion 221 can be the oversized portion described above. As shown in the figure, during installation, the second elastic member 5 can be mounted over the thin neck portion 222 and abut against the thick neck portion 221.

[0038] In the second solution, the valve needle rod 22 can be a variable diameter rod, and the cross-sectional area of ​​the valve needle rod 22 can become smaller and smaller in the direction away from the valve needle head 21. In this way, the valve needle rod 22 can naturally form the aforementioned large-size portion at the end close to the valve needle head 21.

[0039] In comparison, both of the above-mentioned solutions can achieve the installation of the second elastic member 5. During specific implementation, those skilled in the art can choose the solution based on actual needs. Preferably, the valve needle device provided by the present invention can adopt the first solution, i.e., the solution shown in the accompanying drawings. With this solution, the stepped surface between the thick neck portion 221 and the thin neck portion 222 can be a flat surface, which is less likely to generate radial expansion force on the second elastic member 5, thus ensuring the performance of the second elastic member 5 under long-term use.

[0040] Similar to the structure of the drive sleeve 12, the sliding sleeve 3 can also be cylindrical, which can be installed on the valve needle rod 22 and be slidably connected to the valve needle rod 22. One end of the sliding sleeve 3 can be provided with a flange 31, which can be enclosed to form a through hole for the valve needle rod 22 to pass through, and the flange 31 can also serve as a support point for the second elastic member 5. The two ends of the second elastic member 5 can respectively resist the flange 31 and the large-size part.

[0041] Furthermore, a transition sleeve 6 may be included, through which the first elastic member 4 can abut against the valve needle 2, and the transition sleeve 6 can rotate relative to the valve needle 2 about its own axis. In this way, the rotational torque generated by the drive rod assembly 1 through the first elastic member 4 can be partially absorbed by the transition sleeve 6, thereby greatly preventing the valve needle 2 and the drive rod assembly 1 from rotating synchronously.

[0042] Specifically, the transition sleeve 6 can be a bearing or bushing that fits over the sliding sleeve 3. The connecting end of the valve needle head 21 and the valve needle rod 22 can be provided with a radially outwardly extending wing plate 211, and the drive sleeve 12 can contact the wing plate 211. The first elastic member 4 can be a spring that fits over the sliding sleeve 3, with its ends respectively abutting against the transition sleeve 6 and the drive sleeve 12. In this case, the sliding sleeve 3 can also function as a spring column to limit and guide the expansion and contraction of the first elastic member 4, thereby largely preventing radial movement of the first elastic member 4 during expansion and contraction.

[0043] As previously described, in the closed state, the reverse valve opening pressure differential is provided by both the first elastic member 4 and the second elastic member 5. In the open state, the drive rod assembly 1 and the valve needle 2 are supported by the first elastic member 4. To minimize the elastic force of the first elastic member 4 in the open state, the elastic coefficient of the first elastic member 4 can be set to a relatively low value. Thus, in the closed state, the reverse valve opening pressure differential is primarily provided by the second elastic member 5. In one exemplary embodiment, the elastic force of the first elastic member 4 in the closed state can be 7.5%-12.5% ​​of the reverse valve opening pressure differential.

[0044] The present invention also provides an electronic expansion valve, comprising a valve body device and a valve needle device, wherein the valve body device is provided with a valve port, and the valve body device is used to adjust the opening of the valve port, wherein the valve body device is the valve needle device of the electronic expansion valve involved in the above-mentioned embodiments.

[0045] Since the valve needle device of the above-mentioned electronic expansion valve has already achieved the above-mentioned technical effects, the electronic expansion valve having the valve needle device should also have similar technical effects, which will not be elaborated here.

[0046] The above are only preferred embodiments of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A valve needle device for an electronic expansion valve, characterized in that: include: A drive rod assembly (1); A valve needle (2) is slidably connected to the drive rod assembly (1) and is capable of rotating around its own axis relative to the drive rod assembly (1); A sliding sleeve (3) is slidably connected to the valve needle (2); A first elastic member (4) is installed between the drive rod assembly (1) and the valve needle (2); A second elastic member (5) is installed between the sliding sleeve (3) and the valve needle (2); In the valve-open state, the second elastic member (5) supports the sleeve (3) and the valve needle (2), and a gap is set between the drive rod assembly (1) and the sleeve (3); in the valve-closed state, the drive rod assembly (1) overcomes the elastic force of the first elastic member (4) and contacts the sleeve (3), and overcomes the elastic force of the second elastic member (5) through the sleeve (3) to press the valve needle (2).

2. The valve needle device of the electronic expansion valve according to claim 1, characterized in that: The drive rod assembly (1) includes a drive rod (11) and a drive sleeve (12), wherein the drive sleeve (12) is mounted on one end of the drive rod (11), and the valve needle (2) includes a valve needle head (21) and a valve needle rod (22), wherein the valve needle rod (22) is slidably connected to the drive sleeve (12), and a limiting component (23) is further provided between the valve needle rod (22) and the drive sleeve (12).

3. The valve needle device of the electronic expansion valve according to claim 2, characterized in that: The drive sleeve (12) is cylindrical, one end of which is connected to the drive rod (11), and the other end is provided with a sealing plate (121), the sealing plate (121) is provided with a sliding hole (121a), the valve needle rod (22) can be slidably inserted into the sliding hole (121a), and the limiting component (23) is installed on the outer wall of the valve needle rod (22).

4. The valve needle device of the electronic expansion valve according to claim 2, characterized in that: The valve needle rod (22) is provided with a large-sized portion, and the second elastic member (5) is a spring, the outer sleeve of which is mounted on the valve needle rod (22) and has two ends respectively abutting against the large-sized portion and the sliding sleeve (3).

5. The valve needle device of the electronic expansion valve according to claim 4, characterized in that: The valve needle rod (22) is a stepped rod. In a direction away from the valve needle head (21), the valve needle rod (22) comprises a thick neck (221) and a thin neck (222), and the thick neck (221) is the large-size portion.

6. The valve needle device of the electronic expansion valve according to claim 4, characterized in that: The sliding sleeve (3) is also cylindrical, and is placed outside the valve needle rod (22) and is slidably connected to the valve needle rod (22). One end of the sliding sleeve (3) is provided with a flange (31), and the two ends of the second elastic member (5) are respectively against the flange (31) and the large-size portion.

7. The valve needle device of the electronic expansion valve according to any one of claims 1 to 6, characterized in that: It also includes a transition sleeve (6), the first elastic member (4) abuts against the valve needle (2) through the transition sleeve (6), and the transition sleeve (6) can rotate relative to the valve needle (2) around its own axis.

8. The valve needle device of the electronic expansion valve according to claim 7, characterized in that: The valve needle (2) is provided with a wing plate (211) extending radially outward, the transition sleeve (6) is a bearing or a bushing, the transition sleeve (6) is externally mounted on the sliding sleeve (3) and abuts against the wing plate (211); The first elastic member (4) is a spring, which is externally mounted on the sliding sleeve (3), and whose two ends respectively abut against the driving rod assembly (1) and the transition sleeve (6).

9. The valve needle device of the electronic expansion valve according to any one of claims 1 to 6, characterized in that: In the valve closing state, the elastic force of the first elastic member (4) is 7.5%-12.5% ​​of the reverse valve opening pressure difference.

10. An electronic expansion valve, comprising a valve body device and a valve needle device, wherein the valve body device is provided with a valve port, and the valve body device is used to adjust the opening of the valve port, characterized in that: The valve body device is the valve needle device of the electronic expansion valve according to any one of claims 1 to 9.

Images