CN218780781U - Valve needle assembly and electronic expansion valve - Google Patents

Abstract

The utility model relates to a needle subassembly and an electronic expansion valve. The needle subassembly includes: a valve stem provided with a valve stem connector; a valve needle axially movable relative to the valve stem; the elastic element is positioned between the valve rod and the valve needle; and a flexible valve bore seal mounted on the valve needle. The end of the valve stem connector is adapted to be in direct contact with the valve bore seal. The electronic expansion valve includes a valve needle assembly. The valve needle assembly and the electronic expansion valve can form direct contact and soft contact between a valve rod connecting piece and a valve hole sealing piece, the valve rod is flexibly connected with the valve needle, and the movement range of the valve needle relative to the valve rod in the axial direction can be limited, so that reliable performance can be realized in forward application and reverse application while axial flexibility is provided.

Description

Valve needle assembly and electronic expansion valve

Technical Field

The utility model relates to a needle subassembly and an electronic expansion valve. More particularly, the present invention relates to a valve needle assembly and an electronic expansion valve having the same.

Background

The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.

The electronic expansion valve is an important control component in a refrigeration system, and can adjust the opening degree of a valve hole on a valve seat by adjusting the position of a valve needle, so as to adjust the flow of working fluid and adjust the refrigerating capacity. With the development and application of electric buses, heat pumps and the like, the requirement on the bidirectional function of the electronic expansion valve is increasingly strong. In order to ensure reliable and efficient operation of the refrigeration system, the basic performance (e.g., sealing performance) and reliability of the electronic expansion valve in a bi-directional condition is of paramount importance. Therefore, higher requirements are placed on the design of the electronic expansion valve.

As a major component in an electronic expansion valve, the design of the valve needle assembly is critical to the performance of the electronic expansion valve. The valve needle assembly mainly comprises a valve rod and a valve needle. According to the connection mode of the valve needle and the valve rod, the electronic expansion valve is mainly divided into the design of rigid connection of the valve needle and the design of flexible connection of the valve needle. For the rigid connection design of the valve needle, because the valve needle is rigidly connected with the valve rod, the position error generated by processing or assembling parts can not be effectively adjusted, and the clamping phenomenon is easy to occur. In order to ensure the required performance, the rigid connection of the valve needle is designed to have high requirements on the manufacturing precision of each part of the electronic expansion valve, and therefore, the manufacturing cost is high. For the flexible connection design of the valve needle, the valve needle is flexibly connected with the valve rod, and radial flexibility and axial flexibility can be provided to a certain degree, so that the position error can be eliminated, the phenomenon of locking is avoided, and the requirement on the manufacturing precision of each part of the electronic expansion valve can be reduced. In existing valve needle flexible connection designs, axial flexibility of the electronic expansion valve is typically provided by a spring disposed between the valve needle and the valve stem, and is limited only by the stiffness of the spring. The basic performance of the electronic expansion valve in the forward state can be ensured. However, in the reverse state, especially in an application where the flow rate of the working fluid is large, the force applied by the working fluid on the valve needle tends to move the valve needle relative to the valve rod in a state where the electronic expansion valve is not opened, so that a certain opening degree is generated in the valve hole on the valve seat, and thus internal leakage occurs, and therefore, the performance of the electronic expansion valve in the reverse state cannot be ensured.

Therefore, there is a need for an improved design for an electronic expansion valve that ensures reliable performance of the electronic expansion valve in both directions.

SUMMERY OF THE UTILITY MODEL

An object of the present invention is to solve at least one of the above problems.

An aspect of the present invention is to provide a valve needle assembly. The valve needle assembly comprises: the valve rod is provided with a valve rod connecting piece; a valve needle arranged to be axially movable relative to the valve stem; the elastic element is positioned between the valve rod and the valve needle; and a flexible valve bore seal mounted on the valve needle around the valve needle. The end of the valve stem connector is adapted to be in direct contact with the valve bore seal.

The valve needle assembly further comprises a stopping structure, the stopping structure comprises a first stopping portion and a second stopping portion, the first stopping portion is arranged on the valve rod, the second stopping portion is arranged on the valve needle, and the first stopping portion and the second stopping portion are suitable for being mutually abutted to limit the valve needle to move along an axial first direction relative to the valve rod.

The valve needle assembly further includes a valve needle attachment member fixedly mounted on the valve needle and axially positioned between the valve bore seal and the end of the valve stem.

In one embodiment, the first stop is an end of the valve stem and the second stop is a needle attachment.

In one embodiment, an inner step is formed in the valve stem, an end portion of the valve needle is received within the valve stem and faces the inner step, the first stop is the inner step, and the second stop is the end portion of the valve needle.

The valve stem connector is formed with a flange portion. The valve needle connecting member includes a first annular portion adapted to abut the flange portion to limit movement of the valve needle relative to the valve stem in a second direction opposite the first direction and a second annular portion.

In one embodiment, the valve stem connector further comprises a peripheral portion extending from the flange portion in the second direction, the peripheral portion adapted to directly contact the valve bore seal.

A valve rod channel is arranged in the valve rod and penetrates through the valve rod in the axial direction. A valve needle passage is disposed within the valve needle and axially extends through the valve needle and is in fluid communication with the valve stem passage.

In one embodiment, the valve stem includes a neck portion and a body portion, the neck portion having a diameter less than a diameter of the body portion. The neck is adapted to mount a chamber seal and to engage a retainer ring to define an axial position of the chamber seal.

The axial interval between the valve rod connecting piece and the valve hole sealing piece is smaller than the axial interval between the first stopping part and the second stopping part.

Another aspect of the present invention is to provide an electronic expansion valve. The electronic expansion valve includes actuating mechanism and valve seat, the valve seat includes: a first port and a second port, one of the first port and the second port serving as a fluid inlet and the other of the first port and the second port serving as a fluid outlet; a valve bore; an inner chamber in fluid communication with the first port and in fluid communication with the second port via the valve bore. This electronic expansion valve still includes according to the utility model discloses a needle subassembly, needle subassembly mounting are in the disk seat for the needle of needle subassembly aligns with the valve opening. The driving mechanism drives the valve needle assembly to reciprocate along the axial direction, so that the valve needle selectively opens or closes the valve hole. In a closed state of the electronic expansion valve, the valve needle closes the valve hole, and the valve hole sealing member forms a seal between the valve hole and the valve needle.

In a closed state of the electronic expansion valve, the stop structure of the valve needle assembly limits movement of the valve needle relative to the valve stem in a first axial direction to open the valve orifice.

The electronic expansion valve further comprises a support member mounted to the valve seat. At least a portion of the valve stem is received within an internal cavity of the bearing, the valve stem is arranged to be axially movable relative to the bearing, and a chamber seal is mounted between the valve stem and the bearing. The chamber seal is mounted in a mounting groove formed in an inner wall of the bearing or the chamber seal is mounted on a neck of the valve stem.

In one embodiment, the valve seat is provided with a protrusion surrounding the valve bore, the protrusion pressing against the valve bore seal in the closed state of the electronic expansion valve. Preferably, the portion of the valve stem connector that is capable of contacting the valve bore seal is substantially axially aligned with the projection. Preferably, the area of the portion of the valve stem connector that can contact the valve bore seal is substantially the same as the area of the portion of the projection that presses against the valve bore seal.

A cavity is formed between the drive mechanism and the valve needle assembly, a spindle of the drive mechanism is threadedly connected to the valve stem, and a spindle passage is formed in the spindle and is in fluid communication with the cavity and with a valve stem passage in the valve stem and a valve needle passage in the valve needle.

The utility model provides a modified needle subassembly and electronic expansion valve. According to the utility model discloses a needle subassembly and electronic expansion valve construct to make valve rod connecting piece can with valve opening sealing member direct contact to form soft contact between the two, valve rod and needle flexonics, and can also restrict the motion range of needle when axial direction for the valve rod, make when providing axial flexibility, all can prevent reliably in forward application and reverse application interior hourglass, realize reliable performance.

Drawings

Embodiments of the invention will be described below, by way of example only, with reference to the accompanying drawings. In the drawings, like features or components are designated with like reference numerals, and the drawings are not necessarily drawn to scale, and wherein:

figure 1 shows a perspective view of a valve needle assembly according to a first embodiment of the present invention;

figure 2 shows an exploded view of the valve needle assembly shown in figure 1;

figure 3 shows a longitudinal section of the valve needle assembly shown in figure 1;

FIG. 4 is an enlarged view of a portion of FIG. 3;

fig. 5 shows a longitudinal cross-sectional view of an electronic expansion valve having the valve needle assembly shown in fig. 1;

figure 6 shows a perspective view of a valve needle assembly according to a second embodiment of the present invention;

figure 7 shows an exploded view of the valve needle assembly shown in figure 6;

figure 8 shows a longitudinal section of the valve needle assembly shown in figure 6; and

fig. 9 shows a longitudinal sectional view of the electronic expansion valve having the valve needle assembly shown in fig. 6.

Detailed Description

The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, like reference numerals indicate like or similar parts and features. The drawings are only schematic representations, not necessarily indicative of the specific dimensions and proportions of various embodiments of the invention, illustrating the principles and concepts of the embodiments of the invention. Certain features that are in certain figures may be shown exaggerated in detail in order to illustrate relevant details or structures of embodiments of the invention.

In the description of the embodiments of the present invention, the directional terms used in connection with "upper", "lower", "left" and "right" are used in the description of the upper, lower, left and right positions of the views shown in the drawings. In practical applications, the positional relationships of "up", "down", "left" and "right" used herein may be defined according to practical situations, and these relationships may be reversed.

Fig. 1 to 4 show a valve needle assembly 1 according to a first embodiment of the present invention, wherein fig. 1 shows a perspective view of the valve needle assembly 1, fig. 2 shows an exploded view of the valve needle assembly 1, fig. 3 shows a longitudinal sectional view of the valve needle assembly 1, and fig. 4 is a partial enlarged view of fig. 3 showing a portion within an ellipse a in fig. 3.

The valve needle assembly 1 includes a valve needle 10, a valve needle 20, an elastic member 30, a valve-rod connector 40, a valve-needle connector 50, a valve-hole sealing member 60, and a rotation preventing member 70.

The valve rod 10 is a hollow cylinder, a valve rod channel is arranged in the valve rod 10, and the valve rod channel penetrates through the valve rod 10 along the axial direction. The stem channel comprises a first bore 11, a second bore 12, a third bore 13 and a fourth bore 14 connected in series. In the example shown in the figures, the first hole 11 is a threaded hole and the second hole 12, the third hole 13 and the fourth hole 14 are all unthreaded holes. The third bore 13 has a diameter greater than the diameter of the second bore 12 to form a mounting seat 15 within the stem passageway. The fourth bore 13 has an internal diameter greater than the internal diameter of the third bore 13 so as to form an internal step 16 in the stem passageway. The outer peripheral surface of the valve stem 10 is also provided with a flat mating surface 17 to mate with the anti-rotation member 70.

The valve stem 10 is provided with a valve stem attachment 40. In the example shown in the drawings, the stem link 40 is fixedly attached to an end portion (lower end portion in fig. 3) of the valve stem 10, and moves integrally with the valve stem 10. The stem adapter 40 has a cylindrical shape, and a radially extending flange portion 41 is formed in the stem adapter 40. In the example shown in the drawings, the valve-stem connector 40 includes a cylindrical portion 42 and a peripheral portion 43 on axially opposite sides of the flange portion 41, respectively. The cylindrical portion 42 extends from the flange portion 41 in a first axial direction (an axially upward direction in the drawing), the peripheral portion 43 extends from the flange portion 41 in a second opposite direction (an axially downward direction in the drawing), and the outer diameter of the cylindrical portion 42 is larger than the outer diameter of the peripheral portion 43. The upper end portion of the cylindrical portion 42 is fixedly mounted to the lower end portion of the valve stem 10, for example, may be fixedly mounted to the lower end portion of the valve stem 10 by way of an interference fit.

The needle 20 includes a main body portion 21 and a mating portion 22. The fitting portion 22 has a truncated cone shape, a diameter of which is gradually reduced from an end portion connected with the main body portion 21 toward the other end portion, and a maximum diameter of the fitting portion 22 is larger than that of the main body portion 21, thereby forming a stepped portion 23 at a connection between the main body portion 21 and the fitting portion 22. The valve bore seal 60 is mounted on the stepped portion 23 around the valve needle 20. The valve bore seal 60 is flexible and resilient and has good strength to provide a good seal around the valve bore of the valve seat. The valve bore seal 60 may be made of rubber, synthetic resin, or other suitable flexible material. In one example, the valve bore seal 60 is made of teflon. The outer diameter of the valve hole seal 60 is larger than the outer diameter of the stepped portion 23 of the needle 20. A valve needle passage 24 is formed in the valve needle 20, the valve needle passage 24 axially penetrating the valve needle 20.

The valve needle 20 is provided with a valve needle attachment 50. In the example shown in the figures, the needle attachment member 50 is fixedly mounted (e.g., interference fit) on the body portion 21 of the valve needle 20, moving integrally with the valve needle 20. The needle attachment member 50 includes a first annular portion 51 of larger outer diameter and a second annular portion 52 of smaller diameter.

The resilient element 30 is received in the stem passageway of the valve stem 10. In the example illustrated in the figures, the elastic element 30 is a helical spring. One end of the elastic element 30 abuts against the mounting seat portion 15 in the valve stem 10, and the other end of the elastic element 30 extends to the fourth bore 14 of the valve stem 10 to abut against the end portion of the valve needle 20, applying force to the valve needle 20. In the example shown in the drawings, the inner diameter of the third hole 13 in the valve stem 10 is set to substantially correspond to the diameter of the elastic member 30, and while accommodating the elastic member 30, it is possible to provide guidance and positioning for the elastic member 30 so that the elastic member 30 can be stably extended and contracted. However, the present invention is not limited thereto, and in other examples according to the present invention, the inner diameter of the third hole 13 in the valve stem 10 may be significantly larger than the diameter of the elastic element 30. For example, in one example, the inner diameter of the third bore 13 of the valve stem 10 may be the same as the inner diameter of the fourth bore 14, such that the inner step 16 described above is not provided in the stem passage of the valve stem 10.

As shown in fig. 3, when mounted in place, the main body portion 21 of the valve needle 20 is at least partially accommodated in the fourth through hole 14 of the valve stem 10, one end of the resilient element 30 abuts against the mounting seat portion 15 in the valve stem 10, and the other end of the resilient element 30 abuts against an end portion (upper end portion in the drawing) of the main body portion 21 of the valve needle 20. The valve bore seal 60 is axially sandwiched around the valve needle 20 between the step portion 23 of the valve needle 20 and the second annular portion 52 of the valve needle connector 50. The first annular portion 51 of the needle attachment 50 is adapted to rest on the flange portion 41 of the valve stem attachment 40 and forms a first axial spacing d1 between the lower end portion (i.e., the peripheral portion 43) of the valve stem attachment 40 and the upper surface of the valve bore seal 60, a second axial spacing d2 between the first annular portion 51 of the needle attachment 50 and the lower end portion of the valve stem 10, and a third axial gap d3 between the end of the main body portion 21 of the needle 20 and the inner step portion 16 of the valve stem 10, as shown in fig. 4. In a state where the first annular portion 51 of the needle attachment 50 rests on the flange portion 41 of the valve stem attachment 40, for example, during the axial upward movement of the needle 20 with the valve stem 20 or in an open state of the electronic expansion valve, the first axial interval d1, the second axial interval d2, and the third axial interval d3 each have a maximum value.

The valve needle 20 is axially movable relative to the valve stem 10, and as the valve needle 20 moves axially relative to the valve stem 10, the first axial spacing d1, the second axial spacing d2 and/or the third axial spacing d3 may be eliminated such that relative axial movement of the valve needle 20 relative to the valve stem 10 is limited. In the example shown in the figures, the first axial spacing d1 is smaller than the second and third axial spacings d2, d3.

When the first axial interval d1 is eliminated, the valve stem connecting member 40 is in direct contact with the valve bore seal 60, and an end portion (a lower end portion in the drawing, i.e., the peripheral edge portion 43) of the valve stem connecting member 40 abuts against the valve bore seal 60. In one aspect, the valve stem connector 40 may apply a force directly to the valve bore seal 60 such that a better seal is achieved between the valve bore seal 60 and the valve seat. Good sealing between the valve bore seal 60 and the valve seat can be ensured even when the valve needle 20 continues to move axially relative to the valve stem 10 after the first axial spacing d1 is eliminated to reduce the second axial spacing d2 and the third axial spacing d3. On the other hand, the valve stem connector 40 is in direct contact with the valve hole seal 60, and since the valve hole seal 60 itself has flexibility and elasticity, soft contact is formed between the valve stem connector 40 and the valve hole seal 60, noise can be reduced and abrasion can be reduced compared to a scheme in which the valve stem connector 40 is in contact with a rigid member.

In addition, the valve needle assembly 1 is formed with a stop structure arranged to limit further movement of the valve needle 20 in the axial first direction relative to the valve stem 10 after the first axial spacing d1 is eliminated. Otherwise, further movement of the valve needle 20 relative to the valve stem 10 in the first direction will open the valve bore of the electronic expansion valve. The stop structure includes a first stop portion disposed on the valve stem 10 and a second stop portion disposed on the valve needle 20, the first and second stop portions being adapted to abut against each other to limit the valve needle 20 from moving further in the first direction relative to the valve stem 10. After the first axial separation d1 is eliminated, as the valve needle 20 continues to move in the first direction relative to the valve stem 10, the smaller of the second axial separation d2 and the third axial separation d3 will be eliminated, thereby forming a rigid connection between the valve stem 10 and the valve needle 20 and restricting further relative movement of the valve needle 20.

In the example shown in the drawings, the second axial interval d2 is equal to or less than the third axial interval d3, the end of the valve stem 10 (the lower end in the drawings, i.e., the end of the valve stem 10 facing the needle attachment 50) is the first stopper, and the needle attachment 50 is the second stopper. After the first axial interval d1 is eliminated, when the valve needle 20 continues to move in the first direction relative to the valve stem 10, the second axial interval d2 is eliminated, the valve needle connecting piece 50 abuts against the end of the valve stem 10, and a rigid connection is formed between the valve stem 10 and the valve needle 20 via the valve needle connecting piece 50, so that the valve needle 20 is limited from continuing to move in the first direction relative to the valve stem 10. In the process, the third axial spacing d3 may be reduced or eliminated accordingly. That is, when the needle attachment 50 abuts the end of the valve stem 10, the upper end of the needle 20 may abut or be spaced apart from the inner step 16.

However, the present invention is not limited thereto, in other examples according to the present invention, the second axial interval d2 may be greater than the third axial interval d3, so that after the first axial interval d1 is eliminated, when the valve needle 20 continues to move in the first direction relative to the valve stem 10, the third axial interval d3 is eliminated first, the upper end of the valve needle 20 abuts against the inner step portion 16 of the valve stem 10, the inner step portion 16 of the valve stem 10 is formed as a first stopper, and the upper end of the valve needle 20 is formed as a second stopper, which can also limit the relative movement of the valve needle 20 in the first direction relative to the valve stem 10.

Fig. 5 shows a longitudinal section of an electronic expansion valve 100 according to a first embodiment of the present invention. As shown in fig. 5, the electronic expansion valve 100 comprises a valve seat 110, a support 120, a valve needle assembly 1 and a drive mechanism 130.

The valve seat 110 is provided with a first port 111, a second port 112 and an inner cavity 113. The first port 111 is connected to the first pipe L1, and the second port 112 is connected to the second pipe L2. One of the first port 111 and the second port 112 may serve as a fluid inlet, and the other of the first port 111 and the second port 112 may serve as a fluid outlet. The internal cavity 113 communicates with the first port 111, and the internal cavity 113 communicates with the second port 112 via the valve hole 114. A valve hole 114 is formed at a lateral portion of the valve seat 110 and cooperates with the valve seat assembly 1 to adjust an opening degree of the valve hole 114, thereby adjusting a flow rate of a fluid passing through the electronic expansion valve 100. Preferably, the valve seat 110 is provided with a protrusion 115 surrounding the valve hole 114.

Valve needle assembly 1 is mounted within valve seat 110 with valve needle 20 of valve seat assembly 1 aligned with valve bore 114 and mating portion 22 of valve needle 20 capable of being at least partially received within valve bore 114. Valve needle assembly 1 is axially movable relative to valve seat 110 to selectively open or close valve bore 114, allowing inner cavity 113 of valve seat 110 to selectively communicate with second port 112 and second conduit L2.

The support 120 is mounted to an upper end of the valve seat 110, and is sealingly coupled with the valve seat 110 via a first seal S1. At least a portion of the valve stem 10 of the valve needle assembly 1 is accommodated within the inner cavity 121 of the support 120, and the valve stem 10 is sealingly connected with the inner cavity 121 of the support 120 via a cavity seal S2. The chamber sealing member S2 is installed in an installation groove formed in the inner wall of the inner cavity 121 of the support member 120.

The driving mechanism 130 is installed above the support 120, may be a stepping motor, and is connected with a spindle 131. The end of the spindle 131 extends into the inner cavity 121 of the support 120 and is in threaded engagement with the valve stem 10 of the valve needle assembly 1. A chamber 140 is formed between the drive mechanism 130 and the valve needle assembly 1, the chamber 140 being in fluid communication with the inner cavity 121 of the support 120 via gaps between components within the electronic expansion valve 100. A spindle passage 132 is formed in the spindle 131, the spindle passage 132 being in fluid communication with the chamber 140 or the inner cavity 121, and the spindle passage 132 being in fluid communication with the stem passage in the valve stem 10 and the valve needle passage 24 in the valve needle 20.

When the drive mechanism 130 is activated, the spindle 131 rotates. Due to the mounting of the anti-swivel 70, the valve stem 10 is not rotated but only moved in the axial direction, so that the rotational movement of the spindle 131 is converted into an axial movement of the valve stem 10. When the driving mechanism 130 is activated, the valve stem 10 moves in a first direction (axially upward direction), and thereby the valve needle 20 moves in the first direction, thereby opening the valve hole 114 of the valve seat 110. When the drive mechanism 130 is closed, the spindle 131 rotates in reverse until stopped, and the valve stem 10 is thus moved in a second, opposite direction (axially downward direction) so that the mating portion 22 of the valve needle 20 closes the valve bore 114 and the projection 115 surrounding the valve bore 114 abuts the valve bore seal 60 to form a reliable seal. Because the valve rod 10 and the valve needle 20 are flexibly connected through the elastic element 30, the position error caused by processing or assembling parts can be adjusted, the phenomenon of blocking is avoided, and the requirements of the electronic expansion valve 100 on the manufacturing precision and the assembling precision of each part can be reduced.

In the example shown in the figures, the valve needle 20 is at least partially accommodated within a stem channel of the valve stem 10 and is arranged to be axially movable relative to the valve stem 10. However, the present invention is not limited to this. In other examples according to the present disclosure, the valve stem and the valve needle may be coupled such that an end portion of the valve stem is received within an interior of the valve needle to move the valve needle relative to the valve stem along an outer peripheral surface of the valve stem.

In a forward application, the first port 111 serves as a fluid inlet and the second port serves as a fluid outlet. Fluid flows from the first conduit L1 into the interior cavity 113 of the valve seat 110 and out of the second conduit L2. In the closed state of the electronic expansion valve 100, the driving mechanism 130 applies a downward force to the valve needle 20 and the valve hole seal 60 via the valve stem 10, the fluid in the inner cavity 113 also applies a downward force to the valve needle 20 and the valve hole seal 60, and the elastic element 30 applies a downward force to the valve needle 20. These forces cause the fitting portion 22 of the valve needle 20 to fit in the valve hole 114 of the valve seat 110, close the valve hole 114, interrupt fluid communication of the inner cavity 113 of the valve seat 110 with the second pipe 112, and the valve hole seal 60 abuts against the projection 115, forming a good seal around the valve hole 114 of the valve seat 110.

In the reverse application, the second pipe L2 serves as a fluid inlet pipe, and when the valve hole 114 is opened, fluid flows from the second pipe L2 into the inner cavity 113 of the valve seat and flows out from the first pipe L1. In the closed state of the electronic expansion valve 100, the valve hole seal 60 abuts against the projection 115 to form a seal between the valve hole 114 and the valve needle 20, the driving mechanism 130 applies a downward force to the valve needle 20 and the valve hole seal 60 via the valve stem 10, the elastic element 30 applies a downward force to the valve needle 20, and the fluid in the second pipe 112 applies an upward force to the valve needle 20. When the force applied to the valve needle 20 by the fluid can overcome the force of the elastic element 30 on the valve needle 20, the valve needle 20 will move in the first direction (axially upward direction) with respect to the valve seat 110 and the valve stem 10, and the valve needle mount 50 fixedly mounted to the valve needle 20 also moves integrally with the valve needle 20 in the first direction.

When the valve needle 20 moves upward relative to the valve stem 10 such that the first axial interval d1 is eliminated, the lower end portion (i.e., the peripheral edge portion 43) of the valve stem connecting member 40 directly contacts the valve bore seal 60, so that the force of the driving mechanism 130 against the valve stem 10 acts on the valve bore seal 60, so that a good seal is formed around the valve bore 114, and thus no internal leakage occurs. And, when the valve needle 20 continues to move upward relative to the valve stem 10 with the smaller one of the second axial spacing d2 and the third axial spacing d3 eliminated, the connection between the valve stem 10 and the valve needle 20 becomes a rigid connection, so that the distance of axial movement of the valve needle 20 can be limited. At this time, the valve needle 20 cannot continue to move in the first direction (axially upward) due to the downward closing force applied to the valve stem 10 by the driving mechanism 130, and the valve stem coupling member 40 of the valve stem 10 directly applies a downward force to the valve bore seal 60, and the valve bore seal 60 forms a good seal around the valve bore 114 without internal leakage.

Preferably, when installed in place, the portion of the valve stem connector 40 that is capable of contacting the valve bore seal 60 (e.g., the peripheral edge 43) is substantially axially aligned with the projection 115. Preferably, the area of the portion of the valve stem connector 40 that can contact the valve bore seal (e.g., the cross-sectional area of the peripheral edge 43) is substantially the same as the area of the portion of the protrusion 115 that presses against the valve bore seal 60. This enables substantially the same sealing effect to be achieved in both forward and reverse applications.

Accordingly, the electronic expansion valve 100 can have reliable performance in both forward and reverse applications. Additionally, during operation of the drive mechanism 130, fluid may enter the chamber 140 and enter the interior 121 through gaps between components of the electronic expansion valve 100. When the volume of the inner cavity 121 is reduced by the movement of the valve needle assembly 1 in the first direction relative to the support member 120, the fluid in the inner cavity 121 enters the cavity 140 and flows into the second conduit L2 through the spindle passage 132, the stem passage and the valve needle passage 24, and the force of the fluid acting on the valve needle assembly 1 opposite to the movement direction can be reduced. When the valve needle assembly 1 moves relative to the support member 120 in the second direction to increase the volume of the inner cavity 121, the fluid in the second passage L2 can flow into the cavity 140 and the inner cavity 121 through the valve needle passage 24, the stem passage and the spindle passage 132, and the force of the fluid acting on the valve needle assembly 1 in the same direction as the movement direction can be increased. Thus, the above-described arrangement of the spindle passage 132, the stem passage, and the needle passage 24 can reduce the actuation force of the drive mechanism 130.

The valve needle assembly 1 according to the first embodiment of the present invention and the electronic expansion valve 100 having the same have been described above. In the valve needle assembly 1 and the electronic expansion valve 100 according to the present invention, the valve rod connector 40 can be in direct contact with the valve hole sealing member 60, and the valve rod connector 40 can directly apply force to the valve hole sealing member 60 to achieve good sealing, and form soft contact between the valve rod connector 40 and the valve hole sealing member 50, which can reduce noise and reduce wear.

Fig. 6 to 9 show a valve needle assembly 1A according to a second embodiment of the present invention and an electronic expansion valve 100A having the valve needle assembly 1A. Fig. 6 shows a perspective view of a valve needle assembly 1A according to a second embodiment of the present invention, fig. 7 shows an exploded view of the valve needle assembly 1A, and fig. 8 shows a longitudinal sectional view of the valve needle assembly 1A. Fig. 9 shows an electronic expansion valve 100A with a valve needle assembly 1A. The construction of the valve needle assembly 1A according to the second embodiment of the present invention is substantially the same as that of the valve needle assembly 1 according to the first embodiment of the present invention, differing only in the construction of the valve rod, and accordingly the electronic expansion valve 100A differs from the electronic expansion valve 100 only in the construction of the valve rod and the corresponding construction of the bearing fitted with the valve rod. In the drawings, the same portions as those of the needle assembly 1 and the electronic expansion valve 100 are denoted by the same reference numerals, and the description thereof will not be repeated. Hereinafter, only the difference between the valve needle assembly 1A and the valve needle assembly 1, and the difference between the electronic expansion valve 100A and the electronic expansion valve 100 are explained.

The valve stem 10A includes a neck portion 18 and a body portion 19, the neck portion 18 being located at an upper portion of the valve stem 10A. The neck portion 18 has a diameter smaller than that of the body portion 19, so that a flange 181 is formed at an upper portion of the valve stem 10A. Neck 18 is adapted to mount chamber seal S3 and to engage retaining ring 80 to define the axial position of chamber seal S3 with chamber seal S3 between flange 181 and retaining ring 80. Since the chamber seal S3 can be mounted on the neck portion 18, the inner wall of the inner cavity 121A of the support member 120A does not need to be provided with a mounting groove.

According to the utility model discloses a needle subassembly 1A and electronic expansion valve 100A of second embodiment can realize with according to the utility model discloses a needle subassembly 1 and the similar above-mentioned beneficial technological effect of electronic expansion valve 100 of first embodiment.

In addition, in comparison with the electronic expansion valve 100, in the electronic expansion valve 100A according to the second embodiment of the present invention, the chamber seal is installed by providing the neck portion 18 on the valve stem 10A without machining the installation groove inside the support member 120A, so machining is easier, and in the course of relative movement of the valve stem 10A with respect to the support member 120A in the axial direction, the chamber seal S3 is easily held between the support member 120A and the valve stem 10A without being easily detached, and reliable sealing can be achieved.

The above shows a valve needle assembly and an electronic expansion valve having the same according to a preferred embodiment of the present invention.

Here, the exemplary embodiments of the valve needle assembly and the electronic expansion valve having the same of the present invention have been described in detail, but it should be understood that the present invention is not limited to the specific embodiments described and illustrated in detail above. Numerous modifications and variations can be made by those skilled in the art without departing from the spirit and scope of the invention. All such variations and modifications are intended to fall within the scope of the present invention. Moreover, all the components described herein can be replaced by other technically equivalent components.

Claims (15)

1. A valve pin assembly, the valve pin assembly comprising:

a valve stem provided with a valve stem connector;

a valve needle arranged for axial movement relative to the valve stem;

a resilient element located between the valve stem and the valve needle; and

a flexible valve bore seal mounted on the valve needle around the valve needle,

wherein an end of the valve stem connector is adapted to be in direct contact with the valve bore seal.

2. The valve needle assembly of claim 1 further comprising a stop structure comprising a first stop disposed on the valve stem and a second stop disposed on the valve needle, the first and second stops adapted to abut against each other to limit movement of the valve needle in an axial first direction relative to the valve stem.

3. The valve needle assembly of claim 2 further comprising a valve needle connector fixedly mounted on the valve needle and axially between the valve bore seal and the end of the valve stem.

4. The valve needle assembly of claim 3 wherein the first stop is an end of the valve stem and the second stop is the valve needle attachment feature.

5. The valve needle assembly of claim 2 wherein an inner step is formed in the valve stem, an end of the valve needle is received within the valve stem and faces the inner step, the first stop is the inner step and the second stop is the end of the valve needle.

6. The valve needle assembly of claim 3,

the valve rod connecting piece is provided with a flange part;

the valve needle connecting member includes a first annular portion adapted to abut the flange portion to limit movement of the valve needle relative to the valve stem in a second direction opposite the first direction and a second annular portion.

7. The valve needle assembly of claim 6 wherein the valve stem connector further comprises a rim portion extending from the flange portion in the second direction, the rim portion adapted to directly contact the valve bore seal.

8. Valve needle assembly according to any of claims 1-7,

a valve rod channel is arranged in the valve rod and penetrates through the valve rod in the axial direction; and is

A valve needle passage is disposed within the valve needle that passes axially through the valve needle and is in fluid communication with the valve stem passage.

9. The valve needle assembly of any one of claims 1 to 7, wherein the valve stem comprises a neck portion and a body portion, the neck portion having a diameter smaller than a diameter of the body portion;

the neck is adapted to mount a chamber seal and to engage a retainer ring to define an axial position of the chamber seal.

10. A valve needle assembly as claimed in any one of claims 2 to 7 wherein the axial spacing between the valve stem connector and the valve bore seal is less than the axial spacing between the first and second stops.

11. An electronic expansion valve comprising a drive mechanism and a valve seat, the valve seat comprising:

a first port and a second port, one of the first port and the second port serving as a fluid inlet and the other of the first port and the second port serving as a fluid outlet;

a valve bore;

an inner chamber in fluid communication with the first port and in fluid communication with the second port via the valve bore,

wherein the electronic expansion valve further comprises a valve needle assembly according to any of claims 1-10 mounted in the valve seat such that a valve needle of the valve needle assembly is aligned with the valve bore;

the driving mechanism drives the valve needle assembly to reciprocate along the axial direction, so that the valve needle selectively opens or closes the valve hole, the valve needle closes the valve hole in the closing state of the electronic expansion valve, and the valve hole sealing member forms a seal between the valve hole and the valve needle.

12. The electronic expansion valve of claim 11, wherein in a closed state of the electronic expansion valve, a stop structure of the valve needle assembly limits movement of the valve needle in an axial first direction relative to the valve stem to open the valve bore.

13. The electronic expansion valve of claim 11, further comprising a support member mounted to the valve seat; and

at least a portion of the valve stem being received within an internal cavity of the support member, the valve stem being arranged to be axially movable relative to the support member and a chamber seal being mounted between the valve stem and the support member,

wherein the chamber seal is mounted in a mounting groove formed in an inner wall of the bearing or the chamber seal is mounted on a neck of the valve stem.

14. An electronic expansion valve according to any of claims 11-13, wherein the valve seat is provided with a protrusion surrounding the valve bore, which protrusion presses against the valve bore seal in a closed state of the electronic expansion valve; and is provided with

The portion of the valve stem connector that can contact the valve bore seal is substantially axially aligned with the projection, and/or the area of the portion of the valve stem connector that can contact the valve bore seal is substantially the same as the area of the portion of the projection that presses against the valve bore seal.

15. The electronic expansion valve according to any of claims 11-13, wherein a chamber is formed between the drive mechanism and the valve needle assembly, a spindle of the drive mechanism is in threaded connection with the valve stem, and a spindle passage is formed in the spindle, the spindle passage being in fluid communication with the chamber and with the stem passage in the valve stem and the valve needle passage in the valve needle.

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