JP6778752B2 - Two-stage electronic expansion valve - Google Patents

Description

Cross-reference of related applications This application is prioritized for a Chinese patent application filed with the China Patent Office on December 9, 2015, with an application number of 2015109081844.1 and an invention named "two-stage electronic expansion valve". Claim the right and incorporate all its contents into the present application by reference.

Technical Field The present invention relates to the technical field of refrigeration equipment, and more particularly to electronic expansion valves used in inverter air conditioners.

The electronic expansion valve is mainly used in an inverter air-conditioning system, and a high pulse frequency current drives the motor to rotate, directly moves the speed reducer, and raises and lowers the valve needle by transmitting a screw joint and a valve rod. By changing the opening of the valve port, the flow rate of the refrigerant is automatically adjusted to keep the refrigerant circuit system in the best condition from beginning to end.

With reference to FIG. 1, FIG. 1 is a schematic structural diagram of an electronic expansion valve in the prior art.

As shown in FIG. 1, the electronic expansion valve mainly includes a valve body portion for adjusting the flow rate and a coil portion for driving. The coil portion includes a screw joint structure 5'that converts the rotational movement of the motor 1', the speed reducer 2', and the motor 1'to the vertical movement of the screw 3', a nut 4', and a gear box 9'outside the speed reducer 2'. Includes motor housing 6'caulked to the outside of. The valve body portion includes main members such as a valve seat 14', a valve rod 15', and a bellows 11'that controls the elevation of the valve needle 12'. The principle of operation is that the rotor of the motor 1'rotates and the speed reducer 2'rotates, and the screw 3'moves downward by the transmission of the screw joint 5', and the bush 16 which is a force transmission member. By holding the'and the valve stem 15', the valve needle 12'moves downward, in which case the bellows 11'is in an elongated state. When a reverse pulse is applied, the screw 3'moves upwards and the valve needle 12' continuously moves upwards due to the recovery elasticity of the bellows 11'and the pressure action of the system, thereby causing the valve opening 13'. The opening of the'is changed to change the flow path area, where the purpose of controlling the flow rate and adjusting the heating of the system is achieved.

In such an electronic expansion valve structure, the valve is valved from the fully closed state to the initial stage of small flow rate adjustment, that is, while the valve needle 12'contacts the valve port 13'and gradually separates from the valve port 13'. Since the opening of the mouth 13'is small and is remarkably throttled, the fluid flowing through the valve mouth portion is significantly accelerated, abnormal noise due to a vortex of a specific frequency is generated, and the comfort level of the user is impaired. Further, since the electronic expansion valve having this structure has a large valve opening 13', the adjustment range at the time of a small flow rate is narrow, which is disadvantageous for adjustment with higher accuracy.

Therefore, those skilled in the art will determine how to configure an electronic expansion valve that can reduce abnormal noise within the small flow rate adjustment range in the initial stage and improve the width and accuracy of the small flow rate adjustment. This is an urgent issue to be resolved.

The problem to be solved by the present invention is to provide an electronic expansion valve used in an inverter air conditioner, which can reduce abnormal noise within the small flow rate adjustment range and improve the adjustment accuracy at the time of small flow rate adjustment. Is to provide. Therefore, the present invention has the following configuration.

A two-stage electronic expansion valve that includes a motor and a speed reducer connected to the output side of the motor, has a bellows externally attached to the valve stem, and expands and contracts with the reciprocating motion of the valve stem. A valve body that is moved to open and close the first valve port is further included, a small flow rate adjusting mechanism is further provided inside the valve body, and the small flow rate adjusting mechanism is provided at the lower end of the valve stem and inside the valve body. It consists of a second valve port.

The valve body has a tubular shape, and a first cavity and a second cavity are provided at both ends thereof, and a second valve port is opened between the first cavity and the second cavity, respectively. ..

A blocking portion is further provided in the first cavity, the end of the valve stem extends through the blocking portion into the first cavity, and the valve rod and the blocking portion are movably connected to each other. It is realized by a stopper member.

The detent member is a gasket, the valve stem is provided with an annular groove, and the gasket is sandwiched on the annular groove.

The cutoff portion and the valve body are fixed by welding or crimping.

The valve body includes a large-diameter portion and a small-diameter portion, and a distribution portion is provided on the outer peripheral wall of the large-diameter portion.

The valve body is provided with a flow hole for communicating the first cavity and the external space of the valve body.

A first muffling member is provided in the first cavity, and the fluid flowing in from the flow hole is muffled by the first muffling member and then flows out from the second valve port.

A second muffling member is provided in the second cavity.

By crimping and deforming the bottom of the valve body, the second sound deadening member is fixed in the second cavity.

The bottom of the valve body is provided with a pressure contact member that is tightly fitted to the valve body and fixes the second sound deadening member in the second cavity.

The second muffling member includes an upper muffling member and a lower muffling member.

A constant flow device is further provided between the first cavity and the second cavity, and a constant flow rate is constantly maintained between the first cavity and the second cavity.

The gasket has an opening and a contact portion, and the contact portion contacts the peripheral wall of the annular groove.

According to the two-stage electronic expansion valve provided in the present invention, the lower end of the valve body and the first valve port are in constant contact with each other in the small flow rate adjusting stage, and the fluid is brought into contact with each other by a mesh-like sound deadening member. Since the internal vortices and bubbles are largely removed and dispersed, the conventional electronic expansion valve solves the problem of abnormal noise generated when adjusting the small flow rate in the initial stage. At the same time, since the small flow rate adjustment is mainly performed by the second valve port provided inside the valve body, the flow rate adjustment range is wider and the accuracy is higher under the condition of the same number of pulses.

It is a structural schematic diagram of the electronic expansion valve in the prior art. It is a structural schematic diagram of the 1st specific embodiment of the two-stage electronic expansion valve provided in this invention. It is a local structure sectional view of 1st Embodiment of this invention. It is a structural schematic diagram of the gasket of the 1st Embodiment of this invention. FIG. 5 is a local structural sectional view of a second specific embodiment of the two-stage electronic expansion valve provided in the present invention. FIG. 5 is a local structural sectional view of a third specific embodiment of the two-stage electronic expansion valve provided in the present invention. FIG. 5 is a local structural sectional view of a fourth specific embodiment of the two-stage electronic expansion valve provided in the present invention.

In order for those skilled in the art to better understand the technical configuration of the present invention, the present invention will be described in more detail below by combining drawings and specific examples.

(First Embodiment)
With reference to FIGS. 2 and 3, FIG. 2 is a schematic structural diagram of a first specific embodiment of the two-stage electronic expansion valve provided in the present invention. FIG. 3 is a schematic structural diagram of a valve body according to the first embodiment of the present invention.

As shown in FIG. 2, the two-stage electronic expansion valve provided in the present invention mainly includes a valve body portion for adjusting the flow rate and a coil portion for driving. The coil portion is connected to the motor 1 and the output side of the motor 1, and the speed reducer 2 to which the screw 3 is connected to the lower end via the screw joint structure 5. The rotational movement of the motor 1 is changed to the reciprocating movement of the screw 3. A nut 4 is connected between the screw 3 and the gear box 9, including the screw joint structure 5 to be converted, the gear box 9 is externally inserted into the speed reducer 2, and the motor housing 6 of the motor 1 is outside the gear box 9. Be crimped.

The valve body includes the valve seat 14 and the valve rod 15, and the bellows 11 is externally inserted into the valve rod 15, the bellows 11 expands and contracts with the reciprocating motion of the valve rod 15, and the valve body 12 and the valve rod 15 move with each other. Since the valve body 12 is raised and lowered by raising and lowering the valve stem, the first valve port 13 provided in the valve seat 14 is opened and closed.

The term "movably connected to each other" as used in the present invention means that both the valve body and the valve stem can move relative to each other during operation, but cannot escape from each other.

The appearance of the valve body 12 has a substantially tubular shape, has a large diameter portion 121 and a small diameter portion 122, and a first cavity 123 is opened at one end near the large diameter portion 121, and one end near the small diameter portion 122. A second cavity 124 is opened in, and a second valve port 125 is opened between the first cavity 123 and the second cavity 124.

A distribution section 1211 is provided on the outer peripheral wall of the large diameter portion 121, and in the present embodiment, as shown in FIG. 3, the distribution section 1211 is processed into the outer peripheral wall of the large diameter portion 121 for fluid to flow. It is just a little flat. Of course, those skilled in the art can form the shape of the distribution unit 1211 by various designs such as grooving and drilling based on the idea of the present invention, and a fluid can be formed between the upper and lower ends of the large diameter portion 121. Should be allowed to pass.

The lower end portion 152 of the valve stem 15 extends into the first cavity 123 and fits into the second valve port 125, and the second valve port 125 is opened and closed by contact or separation, whereby the flow rate is adjusted. In order to connect the valve rod 15 and the valve body 12, a blocking portion 126 is further provided in the first cavity 123, and the blocking portion 126 is fixedly connected to the inner wall of the large diameter portion 121, and both are welded and crimped. Alternatively, it may be fixed by another method.

An annular groove 151 is provided at a position near the end of the valve stem 15, a detent member is provided in the annular groove 151, and the detent member connects the valve rod 15 and the blocking portion 126 so as to be relatively movable. It becomes possible to keep the state of being. In the present embodiment, the detent member is specifically a gasket 127, and specifically, the gasket 127 is sandwiched in the annular groove 151 so that the valve stem 15 is not released from the regulation by the blocking portion 126. There is. At the time of specific assembly, the valve rod 15 can be attached to the cutoff portion 126, the gasket 127 can be inserted into the annular groove 151, and the cutoff portion 126 can be fixed to the large diameter portion 121 of the valve body, so that the cutoff portion 126 can be fixed. And the gasket 127 both limit the extreme position where the valve stem 15 moves upwards.

FIG. 4 is a schematic structural diagram of the gasket according to the first embodiment of the present invention. The gasket 127 has a substantially "C" shape, has an opening 1272, and is inserted into the annular groove 151 of the valve stem. Three contact portions 1271 are provided inside the gasket 127, and after assembly, they are in close contact with the peripheral wall of the annular groove 151, and a notch portion is further provided between the adjacent contact portions 1271. Of course, FIG. 4 shows, as a specific embodiment, a person skilled in the art can make slight variations based on the technical suggestion. For example, the notch portion is omitted and the contact portion 1271 is integrated. It is possible to realize the object of the invention in the same manner. Further, the sandwiching or fixing to the annular groove 151 is not limited to using a gasket, and for example, by providing a through hole in the annular groove 151 and using a positioning pin, the valve rod 15 and the blocking portion 126 can be similarly used. Can be restricted and concatenated. Such a positioning method should also be clearly included within the protection scope of the present invention.

A flow hole 1221 is opened in the outer peripheral wall of the small diameter portion 122 of the valve body 12, and the number of the flow holes 1221 can be one or more. The flow hole 1221 is the first cavity 123 and the valve body 12. By communicating with the external space, the fluid can flow into the first cavity 123 from the flow hole 1221. A first muffling member 128 is further provided in the first cavity 123 between the flow hole 1221 and the valve port 125, and the fluid flowing in from the flow hole 1221 is muffled by the first muffling member 128 and then. It flows out from the second valve port 125. The first muffling member 128 can be an annular body and fills the first cavity 123 as shown in FIG.

A second cavity 124 is provided at the lower end of the small diameter portion 122, a second muffling member 129 is provided in the second cavity 124, and the lower end of the small diameter portion 122 is deformed by a crimping method at the time of assembly. The second muffling member 129 can be fixed in the second cavity 124.

The first sound deadening member 128 and the second sound deadening member 129 can be made by a method such as a porous sieve net, a wound metal wire, or powder sintering. In the present invention, the material of the sound deadening member or The shape is not limited at all.

Normally, the valve body 12 needs to have a constant flow rate even when the first valve port 13 is closed so that the two-stage electronic expansion valve has a dehumidifying function. In order to realize this object, in the present embodiment, a constant flow device is further provided between the first cavity 123 and the second cavity 124, and in the present embodiment, the constant flow device is a constant flow hole 130. As described above, a part of the flow rate is constantly flowing between the two connecting pipes of the two-stage electronic expansion valve. Of course, the method is not limited to opening the constant flow hole 130 so that there is a constant flow rate even when the first valve port 13 is closed, and based on this, it is replaced with various technical means. Also, for example, an oblique hole is formed in the small diameter portion 122 so that the second cavity 124 is directly communicated with the outside of the valve body 12, or a groove is formed in the inner peripheral wall of the first valve port 13. Similarly, by processing a small amount of the flow groove, it is possible to realize that the valve body has a constant flow rate even when the valve body is closed. Those skilled in the art should understand that the use of some replacement means based on the idea of the present invention is also within the scope of protection of the present invention.

As described above, a small flow rate adjusting mechanism is formed between the lower end portion 152 of the valve stem 15 and the second valve port 125 in the valve body 12.

When the valve stem 15 is displaced from top to bottom, the bellows 11 is in an extended state, the valve body 12 is subjected to a pressure difference action, and the lower end surface of the blocking portion 126 is stuck to the upper end surface of the gasket 127 from beginning to end. After the valve body 12 moves downward to the extreme position and comes into contact with the first valve port 13, the valve stem 15 continues to move downward, in which case the gasket 127 moves downward with the valve stem 15 and the valve stem. Until the lower end portion 152 of 15 comes into contact with the second valve port 125 to form a seal, it is released from the bonding to the blocking portion 126, in which case the two-stage electronic expansion valve is in the closed state.

When the valve is opened, the motor 1 is energized, the bellows 11 contracts, the valve rod 15 is moved so as to be displaced from the bottom to the top, and the valve body 12 is subjected to a pressure difference action, so that the lower end surface of the valve body 12 is affected. Still in contact with the first valve port 13, the valve stem 15 continues to move upwards until the upper end surface of the gasket 127 contacts the lower end surface of the blocking portion 126. As the valve stem 15 continues to move upwards, it moves upwards with the blocking portion 126, in which case the entire valve body begins to move upwards. When the motor 1 is opened so as to have a fully open pulse, the entire two-stage electronic expansion valve is fully opened.

In the above process, the flow rate is mainly between the lower end portion 152 of the valve stem 15 and the second valve port 125 on the valve body in the adjustment distance until the upper end surface of the gasket 127 and the lower end surface of the blocking portion 126 come into contact with each other. The flow rate adjustment range is wider under the same pulse number condition because it is controlled by the opening degree of, that is, in the small flow rate adjustment stage and the valve port becomes smaller. On the other hand, the valve rod 15 moves upward as a whole with the valve body 12, and in this case, the flow rate is mainly controlled by the opening degree between the valve body 12 and the first valve port 13, that is, a large flow rate. It is an adjustment stage.

As described above, in the small flow rate adjusting stage, the lower end of the valve body 12 and the first valve port 13 are in contact with each other from beginning to end, and in this case, the fluid flows in from the flow hole 1221 and the first sound deadening member. After being muted by 128, it flows through the second valve port 125 and is re-silented by the second muffling member 129, and when the fluid flows through the muffling member, it is sufficiently dispersed by the action of a multi-layered mesh. , Eliminate howling-like vortices and reduce noise.

That is, according to the two-stage electronic expansion valve provided in the present invention, the fluid is dispersed by largely removing the vortices and bubbles inside the fluid by the mesh-like sound deadening member. Solves the problem of abnormal noise generated when adjusting the small flow rate in the initial stage. At the same time, since the small flow rate adjustment is mainly performed by the second valve port 125 provided inside the valve body 12, the flow rate adjustment range is wider and the accuracy is higher under the condition of the same number of pulses.

(Second Embodiment)
Hereinafter, the second embodiment of the present invention will be described with reference to FIG. FIG. 5 is a schematic structural diagram of a second specific embodiment of the two-stage electronic expansion valve provided in the present invention. To illustrate the differences between this embodiment and the first embodiment, members having the same structure and function are designated by the same reference numerals.

The two-stage electronic expansion valve has a motor 1, a speed reducer 2 connected to the output side of the motor 1 and a screw 3 connected to the lower end via a screw joint structure 5, and a screw 3 for the rotational movement of the motor 1. A nut 4 is connected between the screw 3 and the gear box 9, the gear box 9 is externally inserted into the speed reducer 2, and the motor housing 6 of the motor 1 is the gear box. It is crimped to the outside of 9.

The valve body portion includes the valve seat 14 and the valve rod 15, and the bellows 11 is externally inserted into the valve rod 15, the bellows 11 expands and contracts with the reciprocating motion of the valve rod 15, and the valve body 12A and the valve rod 15 mutually. Since they are movably connected, the valve body 12A is moved up and down by raising and lowering the valve stem to open and close the first valve port 13 provided in the valve seat 14.

Among the above members, the members other than the structure of the valve body 12 are the same as those in the first embodiment and can be understood with reference to FIG. 2, and the description thereof will be omitted here.

In the present embodiment, the appearance of the entire valve body 12A also has a substantially two-stage tubular structure, has a large diameter portion 121A and a small diameter portion 122A, and has first cavities at the upper and lower ends of the valve body 12A, respectively. The 123A and the second cavity 124A are opened, and the second valve port 125A is opened between the first cavity 123A and the second cavity 124A.

A distribution section 1211A is provided on the outer peripheral wall of the large diameter portion 121A, and in the present embodiment, the distribution section 1211A is a slightly flat surface processed on the outer peripheral wall of the large diameter portion 121A for the flow of fluid. Of course, those skilled in the art can form the shape of the distribution unit 1211A by various designs, for example, grooving, drilling, etc., based on the idea of the present invention, and a fluid can be formed between the upper and lower ends of the large diameter portion 121A. Should be allowed to pass.

The lower end portion 152A of the valve stem 15 extends into the first cavity 123A to form a flow rate adjusting mechanism between the lower end portion 152A and the second valve opening 125A, and the contact or separation between the lower end portion 152A and the second valve opening 125A causes the lower end portion 152A to extend into the first cavity 123A. The second valve port 125A is opened and closed, thereby adjusting the flow rate. In order to connect the valve rod 15 and the valve body 12A, a blocking portion 126A is further provided in the first cavity 123A, the blocking portion 126A is fixedly connected to the inner wall of the large diameter portion 121A, and both are welded and crimped. Alternatively, it may be fixed by another method.

An annular groove 151A is provided at a position near the lower end of the valve stem 15, a detent member is provided in the annular groove 151A, and the detent member connects the valve rod 15 and the blocking portion 126A so as to be relatively movable. It becomes possible to keep the state of being. Similar to the first embodiment, the detent member of the present embodiment can also be the gasket 127A, the structure of which is similar to the gasket 127 of the first embodiment, which is understood with reference to FIG. This can be done, and the description thereof will be omitted here. Both the blocking portion 126A and the gasket 127A limit the extreme position in which the valve stem 15 moves upward.

Of course, as in the first embodiment, those skilled in the art can make slight variations with respect to the detent member based on the technical suggestion, and a gasket is also used for sandwiching or fixing to the annular groove 151. For example, by providing a through hole in the annular groove 151 and using a positioning pin, the valve rod 15 and the blocking portion 126 can be similarly restricted and connected. Such a positioning method should also be clearly included within the protection scope of the present invention.

A flow hole 1212A is opened in the outer peripheral wall of the large diameter portion 121A of the valve body 12A, and the number of the flow holes 1212A can be one or more. The flow holes 1212A are the first cavity 123A and the valve body 12A. By communicating with the external space of the valve body 12A, the fluid can flow into the first cavity 123A from the outside of the valve body 12A through the flow hole 1212A.

A second cavity 124A is provided at the lower end of the small diameter portion 122A, a second muffling member 128A is provided in the second cavity 124A, and the second muffling member 128A is fixed in the second cavity 124A. A pressure welding member 129A is further provided, and the pressure welding member 129A is tightly fitted to the inner wall of the lower end of the small diameter portion 122A, whereby the second sound deadening member 128A is fixed in the second cavity 124A.

The second sound deadening member 128A can be made by a method such as a porous sieve net, a wound metal wire, or powder sintering, and the present invention does not limit the material or shape of the sound deadening member at all.

Similar to the first embodiment, the valve body 12A needs to have a constant flow rate even when the first valve port 13 is closed so that the two-stage electronic expansion valve has a dehumidifying function. is there. In order to achieve this purpose, a constant flow hole (not shown) may be provided between the first cavity 123 and the second cavity 124, and thus the two-stage electronic expansion valve 2 A part of the flow rate is always in circulation between the connecting pipes of the books. Of course, the method is not limited to the constant flow hole so that there is a constant flow rate even when the first valve port 13 is closed, and based on this, it may be replaced with various technical means. Often, for example, by forming an oblique hole in the small diameter portion 122A and allowing the second cavity 124A to communicate directly with the outside of the valve body 12A, or by opening a groove, the inner peripheral wall of the first valve port 13 is slightly formed. Similarly, by processing the flow groove of the above, it is possible to realize that the valve body has a constant flow rate even when the valve body is closed. Those skilled in the art should understand that the use of some replacement means based on the idea of the present invention is also within the scope of protection of the present invention.

As described above, a small flow rate adjusting mechanism is formed between the lower end portion 152A of the valve stem 15 and the second valve port 125A in the valve body 12A.

When the valve stem 15 is displaced from top to bottom, the bellows 11 is in an extended state, the valve body 12 is subjected to a pressure difference action, and the lower end surface of the blocking portion 126 is stuck to the upper end of the detent member (gasket 127A) from beginning to end. After being aligned and the valve body 12A moves downward to the extreme position and contacts the first valve port 13, the valve stem 15 continues to move downward, in which case the gasket 127A moves downward with the valve stem 15. , The lower end portion 152A of the valve stem 15 is released from the bonding to the blocking portion 126A until it contacts the second valve port 125A to form a seal, in which case the two-stage electronic expansion valve is in the closed state.

When the valve is opened, the motor 1 is energized, the bellows 11 contracts, the valve stem 15 is displaced from top to bottom, and the valve body 12A is subjected to a pressure difference action, so that the lower end surface of the valve body 12A is still the first. Keeping contact with the valve port 13, the valve stem 15 continues to move upward until the upper end of the gasket detent member (127A) comes into contact with the lower end surface of the blocking portion 126A. When the valve stem 15 continues to move upward, the shutoff portion 126A is moved upward, and in this case, the entire valve body starts to move upward. When the motor 1 is opened so as to have a fully open pulse, the entire two-stage electronic expansion valve is fully opened.

In the above process, the flow rate is mainly the lower end portion 152A of the valve stem 15 and the second valve on the valve body in the adjustment distance until the upper end surface of the detent member (gasket 127) and the lower end surface of the blocking portion 126A come into contact with each other. It is controlled by the opening degree between the port 125A, that is, it is a small flow rate adjustment stage, and the valve port becomes smaller, so that the flow rate adjustment range is wider under the condition of the same number of pulses. On the other hand, the valve rod 15 moves upward as a whole with the valve body 12, and in this case, the flow rate is mainly controlled by the opening degree between the valve body 12A and the first valve port 13, that is, a large flow rate. It is an adjustment stage.

As described above, in the small flow rate adjusting stage, the lower end of the valve body 12 and the first valve port 13 are in contact with each other from beginning to end, and in this case, the fluid flows from the flow hole 1212A into the first cavity 123A. After being squeezed, it flows through the second valve port 125A and is muted by the muffling member 128A, and when the fluid flows through the muffling member, it is sufficiently dispersed by the action of a multi-layered mesh, thereby a howling-like vortex. And reduce noise.

That is, according to the two-stage electronic expansion valve provided in the present invention, the fluid is dispersed by largely removing the vortices and bubbles inside the fluid by the mesh-like sound deadening member. Solves the problem of abnormal noise generated when adjusting the small flow rate in the initial stage. At the same time, since the small flow rate adjustment is mainly performed by the second valve port 125A provided inside the valve body 12A, the flow rate adjustment range is wider and the accuracy is higher under the same pulse number condition.

(Third Embodiment)
In the third embodiment, the second sound deadening member 128A is fixed in the second cavity 124A by a crimping method, that is, as shown in FIG. 6, the lower end portion 1222A of the small diameter portion 122A is fixed. It differs from the second embodiment in that the second sound deadening member 128A is fixed by crimping and deforming, that is, a method similar to the fixing method of the second sound deadening member in the first embodiment is used. To do. The other parts of the present embodiment are the same as those of the second embodiment, and the description thereof will be omitted here.

(Fourth Embodiment)
In the fourth embodiment, the second muffling member is specifically divided into two layers, an upper muffling member 1281A and a lower muffling member 1282A, in order to fix the muffling member in the second cavity 124A. A pressure welding member 129A is further provided so that the pressure welding member 129A is tightly fitted to the inner wall of the lower end of the small diameter portion 122A, thereby fixing the upper sound deadening member 1281A and the lower sound deadening member 1282A in the second cavity 124A. , Different from the second embodiment. Of course, the sound deadening member is not limited to two layers, and may be two or more layers, and those skilled in the art can understand that the object of the present invention can be realized by this as well. In the present embodiment, the corresponding description of the second embodiment can be referred to for other parts, and the description thereof will be omitted here.

The terms such as "top", "bottom", "left", and "right" appearing in the present invention are based on the structure shown in the drawings of the specification, and limit the scope of protection of the present invention. You should not understand that you are.

The electronic expansion valve used in the inverter air conditioner provided in the present invention has been introduced in detail above. In this text, the principle and embodiments of the present invention have been described using specific examples, but the above description of the examples is merely for understanding the method and gist of the present invention. It should be pointed out that a person skilled in the art can make some improvements and modifications to the present invention on the premise that the principle of the present invention is not deviated. These improvements and modifications are also included within the scope of the present invention.

Claims (12)

A two-stage electronic expansion valve that includes a motor and a speed reducer connected to the output side of the motor, has a bellows externally attached to the valve stem, and expands and contracts with the reciprocating motion of the valve stem. A valve body that is moved by the valve stem to open and close the first valve opening is further included, and a small flow rate adjusting mechanism is further provided inside the valve body. The small flow rate adjusting mechanism includes a lower end portion of the valve stem and the valve body. Ri Do and a second valve port which is provided in the interior of the valve body,
The valve body has a tubular shape, and a first cavity and a second cavity are provided at both ends thereof, and the second valve port is opened between the first cavity and the second cavity, respectively. Has been
The valve body includes a large diameter portion and a small diameter portion, and said and circulation unit is provided on the outer peripheral wall of the large diameter portion, characterized Rukoto flow holes in the outer peripheral wall of the small diameter portion is opened 2 Staged electronic expansion valve. A blocking portion is further provided in the first cavity, the lower end portion of the valve stem extends into the first cavity through the blocking portion, and the valve rod and the blocking portion are movably connected to each other. The two-stage electronic expansion valve according to claim 1 , wherein this is realized by a detent member. The two-stage electronic expansion valve according to claim 2 , wherein the detent member is a gasket, the valve stem is provided with an annular groove, and the gasket is sandwiched on the annular groove. The two-stage electronic expansion valve according to claim 2 , wherein the blocking portion and the valve body are fixed by welding or crimping. The two-stage electronic expansion valve according to claim 1 , wherein the valve body is provided with a flow hole for communicating the first cavity and the external space of the valve body. A claim, wherein a first sound deadening member is provided in the first cavity, and a fluid flowing in from the flow hole is sound deadened by the first sound deadening member and then flows out from a second valve port. two-stage electronic expansion valve according to 5. The two-stage electronic expansion valve according to claim 5 , wherein a second sound deadening member is provided in the second cavity. The two-stage electronic expansion valve according to claim 7, wherein the second sound deadening member is fixed in the second cavity by crimping and deforming the bottom portion of the valve body. 7. The seventh aspect of the invention is characterized in that the bottom of the valve body is provided with a pressure welding member that is tightly fitted to the valve body and fixes the second sound deadening member in the second cavity. The two-stage electronic expansion valve described. The two-stage electronic expansion valve according to claim 8 or 9 , wherein the second muffling member includes an upper muffling member and a lower muffling member. A constant flow device is further provided between the first cavity and the second cavity, and a constant flow rate is constantly maintained between the first cavity and the second cavity. The two-stage electronic expansion valve according to claim 1. The two-stage electronic expansion valve according to claim 3 , wherein the gasket has an opening and a contact portion, and the contact portion contacts the peripheral wall of the annular groove.