CN111853252A

CN111853252A - Electronic expansion valve

Info

Publication number: CN111853252A
Application number: CN201910363015.7A
Authority: CN
Inventors: 不公告发明人
Original assignee: Zhejiang Sanhua Intelligent Controls Co Ltd
Current assignee: Zhejiang Sanhua Intelligent Controls Co Ltd
Priority date: 2019-04-30
Filing date: 2019-04-30
Publication date: 2020-10-30

Abstract

The invention provides an electronic expansion valve which comprises a valve seat assembly, wherein the nut assembly comprises a plastic nut which is matched and fixed with the valve seat assembly, the plastic nut is provided with a matching section, the matching section is provided with an axially extending connecting hole, the outer wall part of the matching section is provided with at least two contact parts which are circumferentially arranged at intervals, a sunken part is formed between the adjacent contact parts, the contact parts are used for being in press fit with the valve seat assembly, and a radial gap is formed between the sunken part and the valve seat assembly. The radial clearance can absorb the extrusion deformation of the contact part, thereby improving the deformation problem possibly generated during the press fitting of the nut.

Description

Electronic expansion valve

Technical Field

The invention relates to the technical field of refrigeration, in particular to an electronic expansion valve.

Background

The electronic expansion valve is generally provided with a transmission mechanism for converting rotation into linear motion, the transmission mechanism generally comprises a screw rod with external threads and a nut with internal threads, the nut can be made of metal materials or plastic injection molding, the nut is used as a fixing part and can be fixed with a valve seat through press mounting or welding, the screw rod is provided with external threads, the nut is provided with internal threads, the screw rod rotates and simultaneously performs lifting motion through the action of a thread pair, and the screw rod is connected with a valve needle, so that the screw rod can drive the valve needle to be close to or far away from a valve port during the lifting motion so as to realize the adjustment of the flow of the electronic refrigerant expansion valve.

Referring to fig. 1 and 2, fig. 1 is a schematic cross-sectional view of a typical nut in the background art; fig. 2 is a structural view of the nut and the valve seat in a plan view. Wherein a cylindrical nut 21 'with an internal thread is fixed on the valve seat 11', and a screw 22 'with an external thread is screwed with the nut 21'. It can be seen that the cylindrical nut 21 'is press-fitted into the cylindrical bore of the valve seat 11'.

When the nut is made of plastic through injection molding and is fixedly pressed with the valve seat, the structure of the nut can be improved, so that the problem of deformation possibly generated in the pressing process of the plastic nut is solved.

Disclosure of Invention

The invention aims to provide an electronic expansion valve, which can relatively reduce the risk of thread transmission clamping failure caused by the possible deformation of a nut when the plastic nut is pressed on a valve seat.

In order to achieve the above purpose, the present invention provides an electronic expansion valve, which includes a valve seat assembly, wherein the nut assembly includes a plastic nut that is fixed in a matching manner with the valve seat assembly, the plastic nut is provided with a matching section, the matching section is provided with a connecting hole that extends in an axial direction, the outer wall portion of the matching section is provided with at least two contact portions that are circumferentially arranged at intervals, a recessed portion is formed between adjacent contact portions, the contact portions are used for being in press fit with the valve seat assembly, and a radial gap is formed between the recessed portion and the valve seat assembly. The radial clearance can absorb the extrusion deformation of the contact part, thereby improving the deformation problem possibly generated during the press fitting of the nut.

Drawings

FIG. 1 is a cross-sectional view of a typical nut of the prior art;

FIG. 2 is a view of the nut and valve seat in plan view;

FIG. 3 is a schematic diagram of an electronic expansion valve according to an embodiment of the present invention;

fig. 4 is a cross-sectional view of the electronic expansion valve shown in fig. 3;

FIG. 5 is a cross-sectional top view of a drive mechanism in the electronic expansion valve of FIG. 3;

fig. 6 is a longitudinal cut-away view of the drive mechanism in the electronic expansion valve shown in fig. 3;

FIG. 7 is a cross-sectional view of a nut assembly provided by the present invention in example 1;

FIG. 8 is a top view of a web of nut assemblies provided in the present invention in example 1;

FIG. 9 is a top view of the nut assembly provided by the present invention in example 1;

FIG. 10 is a bottom view of the nut assembly of the present invention in example 1;

FIG. 11 is a bottom view of the nut assembly of the present invention in example 2;

fig. 12 is a bottom view of the nut assembly provided by the present invention in example 3.

In fig. 1-2:

valve seat 11 ', cylindrical nut 21 ', screw 22 ';

in fig. 3-12:

the valve seat component comprises a valve seat component 1, a plastic nut 2, a matching section 3, a connecting hole 4, a contact part 5, a concave part 6, a connecting plate 7, a pressure equalizing hole 8, a radial concave-convex part 9, a guide section 11, a guide hole 12, a transmission rod 13, a valve body 100, a coil 200, a valve seat part 10, a transmission mechanism 20, a speed reducing mechanism 30, a housing part 40 and a rotor 50.

Detailed Description

The following description of the present invention will be provided in order to enable those skilled in the art to more accurately understand the technical solutions of the present invention.

The axial direction, the circumferential direction and the radial direction are all referred to by the electronic expansion valve, the extending direction of a central axis of the electronic expansion valve is taken as the axial direction, the rotating direction of a rotor of the electronic expansion valve is taken as the circumferential direction in a horizontal plane perpendicular to the axial direction, and the diameter extending direction of the rotor is taken as the radial direction; when the described body relates to a nut assembly only, the extending direction of the central axis of the nut assembly is taken as the axial direction, the surrounding direction of the cylindrical surface of the nut is taken as the circumferential direction, and the diameter direction of the nut is taken as the radial direction.

The inside and outside of the electronic expansion valve takes the central axis of the electronic expansion valve as a reference, the direction close to the central axis is the inside, and the direction far away from the central axis is the outside. Further, the inside and outside described herein refer to a positional relationship in the radial direction of the electronic expansion valve, and the positional relationship is described above and below in the axial direction of the electronic expansion valve. However, the above and below are only referred to the orientation in the drawings, and are only for the purpose of illustration, and should not be construed as limiting the usage environment, structure, etc. of the electronic expansion valve or the nut assembly.

The terms first, second, etc. described herein are used only for distinguishing two or more components having the same or similar structures or two or more structures having the same or similar structures, and do not denote any particular order or importance.

As shown in fig. 3 and 4, the present invention provides an electronic expansion valve, taking an electronic expansion valve as an example, the electronic expansion valve includes a valve body 100 and a coil 200; wherein, valve body 100 includes: the valve seat member 10, the transmission mechanism 20, the reduction mechanism 30, the cover member 40, and the rotor 50 of the drive mechanism (including the coil 200). The action principle is as follows: after the coil 200 is energized, electromagnetic force is generated to drive the rotor 50 to rotate, and after the rotation of the rotor 50 is decelerated by the decelerator 30, the rotation is converted into linear motion by the transmission mechanism 20 and transmitted to the valve needle of the valve seat member 10, so that the valve needle makes linear motion along the direction of opening and closing the valve port, thereby controlling the opening degree of the electronic expansion valve.

As shown in fig. 5 and 6, the transmission mechanism includes a nut assembly and a transmission rod 13, the nut assembly can be mounted on the valve seat assembly 1 by press fitting, and can be assisted by welding to improve the connection reliability; the transmission rod 13 is matched with the nut component and converts the rotary motion of the rotor into axial linear motion so as to drive the valve needle to move in the direction of opening and closing the valve port.

As described in the background, since the nut needs to be press-fitted with interference with the seat assembly 1, the seat assembly 1 may apply a radial pressing force to the nut, possibly causing deformation of the nut. Simultaneously, the nut is equipped with axially extending's connecting hole 4, and this connecting hole 4 has the internal thread for realize being connected with the screw drive of transfer line 13, the deformation of nut can arouse the deformation of connecting hole 4, and then influences the cooperation of connecting hole 4 and transfer line 13, leads to transfer line 13 to be blocked in transmission process or even the card is dead to lose efficacy.

The nut component is suitable for the electronic expansion valve, and the problem that the transmission is locked and fails due to the deformation of the connecting hole 4 of the nut component is solved.

The nut assembly of the present invention is described in detail below with reference to fig. 7-12.

Example 1

As shown in fig. 7 to 10, in the embodiment 1, the nut assembly includes the plastic nut 2, the plastic nut 2 is provided with the fitting section 3 for fitting with the valve seat assembly 1, and the fitting section 3 is provided with the axially extending coupling hole 4 for coupling with the above-mentioned transmission rod 13; wherein, the outer wall of cooperation section 3 is equipped with the contact site 5 that two at least circumference intervals set up to, form depressed part 6 between the adjacent contact site 5, when plastics nut 2 and valve seat subassembly 1 assemble, carry out press fit with valve seat subassembly 1 with the contact site 5 of cooperation section 3, at this moment, depressed part 6 and valve seat subassembly 1 contactless form radial clearance between depressed part 6 and valve seat subassembly 1, as shown in fig. 5. Therefore, when the plastic nut 2 is pressed on the valve seat assembly 1, the contact part 5 can generate extrusion deformation, the extrusion deformation can extend towards the concave parts 6 on the two sides of the contact part 5 in the circumferential direction along the circumferential direction, the extrusion deformation is absorbed by the concave parts 6, the extrusion force is prevented from being further transmitted to the connecting hole 4 in the radial inner part in the radial direction, and the connecting hole 4 keeps the original shape and is prevented from being influenced by deformation; when the connecting hole 4 keeps the original shape, the connecting hole can be reliably matched with the transmission rod 13, the transmission reliability is ensured, and the clamping failure is avoided.

The engagement section 3 may be formed in a cylindrical shape as a whole, and has a connection hole 4 formed at a middle portion thereof to extend therethrough in an axial direction, and an outer wall portion thereof may have a portion lacking to form a recess 6, and a portion other than the recess 6 may form a contact portion 5. The recess 6 may be formed at a time of injection molding of the nut, or may be formed by cutting after the nut is molded.

The skilled person in the art can configure the number of the deficient portions as required, and may be provided with at least three deficient portions, extension lines of contour lines of the deficient portions sequentially intersect to form a regular polygon, and in the pitching state, the center of the regular polygon coincides with the center of a projection circle of the matching section 3 in the pitching state, that is, the center of the regular polygon is located on the central axis of the matching section 3. In this embodiment, for example, six cutout portions are provided, and as shown in fig. 5, 9, and 10, the fitting section 3 is provided with hexagonal cutout portions; at this time, the contact portion 5 may be formed by chamfering the vertices of the regular hexagon.

As shown in fig. 7 and 8, the nut assembly of the present invention further includes a connecting plate 7 fixedly connected to the plastic nut 2, the connecting plate 7 is disposed by the fitting section 3 in a protruding manner in a radial direction, and is used for connecting an end of the valve seat assembly 1 disposed opposite to the valve port, thereby dividing the valve cavity into two parts, the inner cavity of the valve seat assembly 1 constitutes one of the two parts, the contact portion 5 is press-fitted into the inner cavity of the valve seat assembly 1, and the connecting plate 7 is provided with a pressure equalizing hole 8 for communicating the two parts of the valve cavity.

As can be seen from fig. 5 and 6, the plastic nut 2 is fixedly connected with a connecting plate 7 on its outer circumference, and according to the orientation in the drawing, the plastic nut 2 forms a mating segment 3 with its portion at the lower end of the connecting plate 7, and the connecting plate 7 is arranged to protrude radially outward relative to the mating segment 3; during installation, the matching section 3 is pressed with the valve seat assembly 1 for interference fit to ensure coaxiality, at the moment, the contact part 5 is contacted with the valve seat assembly 1 and deforms under the influence of interference extrusion force, and the deformation stretches towards the concave part 6 to avoid the influence of extrusion deformation on the connecting hole 4; meanwhile, the connecting plate 7 can be lapped on the end face of one end of the valve seat assembly 1 (the end face is an end face arranged opposite to the valve port and corresponds to the upper end face of the valve seat assembly 1 in the figure, and the lower end face of the valve seat assembly 1 corresponds to the valve port) and is fixedly connected with the valve seat assembly 1 in a welding mode and the like, namely, the nut assembly is fixedly connected with the valve seat assembly 1 in an interference press-fitting mode and a welding mode, so that the connection reliability is improved.

Because the inner cavity of the valve seat component 1 is used for realizing the press mounting of the plastic nut 2, the connecting plate 7 is also provided with a pressure equalizing hole 8 which is used for communicating the inner cavity of the valve seat component 1 with the cavity at the upper part of the connecting plate 7. In fact, the connecting plate 7 is equivalent to a partition plate and divides the inner cavity (i.e. the valve cavity) of the whole valve body into two parts, which correspond to the upper part and the lower part in the figure, the part below the connecting plate 7 is the inner cavity of the valve seat assembly 1, the part above the connecting plate 7 is a cavity outside the valve seat assembly 1, and the pressure equalizing hole 8 is used for communicating the two parts, so that the pressure equalizing of the valve cavity is realized up and down. In addition, the inner cavity of the valve seat component 1 is used for press-fitting the matching section 3 of the plastic nut 2, the concave part 6 of the matching section 3 is used for forming a radial gap with the valve seat component 1, and the pressure equalizing hole 8 is actually communicated with the concave part 6 and the radial gap of the valve seat component 1, so that the upper pressure equalizing and the lower pressure equalizing of the valve cavity are realized.

In this embodiment, the connecting plate 7 and the plastic nut 2 may be molded integrally, and specifically, the plastic nut 2 may be molded on the basis of the connecting plate 7 to form a nut assembly integrated with injection molding. The connection hole 4 of the plastic nut 2 may be directly formed at the time of injection molding, and an internal thread structure may also be directly formed as a connection structure of the connection hole 4. At this time, the pressure equalizing hole 8 provided in the connecting plate 7 may also be used as a positioning hole for injection molding of the plastic nut 2.

As shown in fig. 8, the pressure equalizing hole 8 may be a semi-arc notch formed in the outer ring of the connecting plate 7, and two pressure equalizing holes 8 disposed opposite to each other in the radial direction may be formed in the connecting plate to achieve reliable positioning during pressure equalizing and injection molding.

And, the inner ring of the connection plate 7 with the plastic nut 2 may be provided with a radial concave-convex portion 9 for increasing the coupling force between the connection plate 7 and the plastic nut 2. As shown in fig. 8, the radial concave-convex portion 9 may be specifically a radial groove, or may be a radial protrusion, when the radial concave-convex portion 9 is a radial groove, the connecting plate 7 may be configured as an annular plate, and a tooth-shaped gap may be provided in an inner ring of the connecting plate 7 as a radial groove, and when the injection molding material is filled in the inner ring of the connecting plate 7, the radial groove is filled, so that the plastic nut 2 is combined with the connecting plate 7 at the radial groove; since the radial concave-convex portion 9 has a certain extension area in the circumferential direction and the axial direction, the radial bonding force is improved, and the bonding reliability in the circumferential direction and the axial direction is also improved. The skilled person can also set two or more than three radial concave-convex parts 9 arranged at intervals in the circumferential direction as required, and specifically, the form of uniform distribution in the circumferential direction can be adopted.

Referring to fig. 7 to 10 again, the plastic nut 2 may further have a guiding section 11, the guiding section 11 has a guiding hole 12 communicated with the connecting hole 4, the driving rod 13 may further have a guiding portion matched with the guiding hole 12, the guiding portion may be axially slidably matched with the guiding hole 12, when the driving rod 13 is installed, the guiding portion may extend into the guiding hole 12 to achieve axial guiding matching, and then the driving portion at the lower end of the guiding portion is in threaded connection with the connecting hole 4 to achieve driving matching. As can be seen from fig. 7, the guide section 11 is located at the other end of the connecting piece opposite to the mating section 3, i.e. the lower part of the connecting plate 7 forms the mating section 3 mating with the valve seat assembly 1, and the upper part forms the guide section 11 for guiding the transmission rod 13 to extend into the connecting hole 4.

Because the guide section 11 only plays a role in guiding, no special requirement is required for the appearance of the nut, and the nut can be designed into a cylindrical structure with a smaller outer diameter, so that the outer diameter of the guide section 11 is smaller than that of the matching section 3, and the material is saved.

It should be noted that, the guide section 11 and the mating section 3 are relative, and since the outer diameter of the guide section 11 is smaller than that of the mating section 3, a step surface is formed at the connection position of the guide section 11 and the mating section 3, and if the connecting plate 7 is installed at the position of the step surface, the strength of the connecting plate 7 may be affected. Therefore, in the present embodiment, the connecting plate 7 can be installed at a position corresponding to the fitting section 3, and the connecting plate 7 is similarly inserted into the middle upper portion of the fitting section 3 in appearance. That is, the mounting position of the connection plate 7 can be flexibly set.

Example 2

In the second embodiment, as shown in fig. 11, four sides may be cut on the outer circumference of the plastic nut 2 to form four recesses 6, and the contact portions 5 may be formed between the adjacent recesses 6. A person skilled in the art may also cut three or more sides as needed, and may specifically refer to this embodiment and embodiment 1 to perform the setting. The structure of the other portions, such as the connecting plate 7, can be provided with reference to embodiment 1, and the present embodiment may be different from embodiment 1 only in the number of the recesses 6.

Example 3

As shown in fig. 12, in the third embodiment, the contact portion 5 and the recessed portion 6 may be formed in another way, that is, a rib protruding in the radial direction and extending in the axial direction is provided on the outer peripheral wall of the mating segment 3, in this case, the rib protrudes from the surface of the mating segment 3, a recessed structure is formed on the portion where the rib is not provided with respect to the rib, the rib forms the contact portion 5, and the portion between two circumferentially adjacent ribs forms the recessed portion 6.

The present embodiment may be different from embodiment 1 only in the formation of the contact portion 5 and the recess portion 6, and other portions may be provided with reference to embodiment 1.

According to the nut component provided by the embodiment of the invention, the plastic nut and the valve seat component are in press fit, and the press fit belongs to interference fit, so that the plastic nut may deform during press fit. According to the scheme, the matching section of the plastic nut is divided into the contact part and the concave part, and the contact part is only in press fit with the valve seat assembly so as to ensure coaxiality; meanwhile, a radial gap between the contact part and the valve seat assembly is formed through the concave part, when the contact part is extruded by the valve seat assembly, the contact part can naturally extend towards the concave part adjacent to the contact part along the circumferential direction, the extrusion force can not be further transmitted to the inner connecting hole along the radial direction, so that the extrusion deformation of the contact part is absorbed through the concave part, the deformation of the connecting hole caused by extrusion is avoided, the connecting hole can better keep the original shape, the reliable transmission fit with a transmission mechanism such as a valve rod is formed, and the possibility of the occurrence of the blocking failure is relatively reduced.

It is to be understood that although a specific electronic expansion valve structure is described herein, the core of the present invention lies in the matching structure of the nut assembly and the valve seat assembly, and other parts or assemblies of the electronic expansion valve, such as the coil, the transmission mechanism, the reduction mechanism, the rotor, etc., are introduced only for facilitating the understanding of the working principle of the electronic expansion valve by those skilled in the art, and are not limited to the above-mentioned other parts or assemblies. Any valve component which needs to be matched with the valve seat component 1 by adopting the nut component described in the above embodiment can belong to a generalized electronic expansion valve.

The electronic expansion valve provided by the invention is described in detail above. The principles and embodiments of the present invention are explained herein using specific examples, which are presented only to assist in understanding the core concepts of the present invention. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention.

Claims

1. The utility model provides an electronic expansion valve, includes nut component and valve seat subassembly (1), the nut component include with valve seat subassembly (1) cooperation fixed plastics nut (2), plastics nut (2) are equipped with cooperation section (3), cooperation section (3) are equipped with axially extended connecting hole (4), its characterized in that, the outer wall portion of cooperation section (3) is equipped with contact site (5) that two at least circumference intervals set up, and is adjacent form depressed part (6) between contact site (5), contact site (5) be used for with valve seat subassembly (1) press-fit, depressed part (6) with radial clearance has between valve seat subassembly (1).

2. An electronic expansion valve according to claim 1, wherein the peripheral wall of the engagement section (3) is provided with axially extending recesses forming the recesses (6), and the portions between two circumferentially adjacent recesses form the contact portions (5).

3. An electronic expansion valve according to claim 2, wherein the engagement section (3) is provided with at least three indentations, and in a cross-section of the engagement section (3) the extensions of the contour lines of the indentations intersect one another in sequence to form a regular polygon centered on the central axis of the engagement section (3) and enclosing the contour line of the engagement section (3).

4. An electronic expansion valve according to claim 1, wherein the peripheral wall of the engagement section (3) is provided with radially projecting and axially extending ribs which form the contact portions (5), and portions between two circumferentially adjacent ribs form the recesses (6).

5. An electronic expansion valve according to any of claims 1-4, further comprising a connecting plate (7) fixedly connected to said plastic nut (2), said connecting plate (7) being integrally injection-molded with said plastic nut (2), said connecting plate (7) being fixedly connected to an end of said valve seat assembly (1) disposed opposite to a valve port, said contact portion (5) being press-fitted into an inner cavity of said valve seat assembly (1), said connecting plate (7) being provided with a pressure equalizing hole.

6. An electronic expansion valve according to claim 5, wherein the inner ring of the connection of the web (7) to the plastic nut (2) is provided with radial reliefs (9).

7. An electronic expansion valve according to claim 5, wherein the plastic nut (2) further has a guide section (11), the guide section (11) having a guide hole (12) communicating with the connection hole (4), the guide section (11) being at the other end of the connection piece opposite to the fitting section (3).

8. An electronic expansion valve according to claim 7, wherein the guide section (11) has an outer diameter smaller than the outer diameter of the mating section (3).