Mold and method for manufacturing electronic expansion valve nut

Abstract

A mold, a nut and a manufacturing method of the nut, wherein the axial projection of the second mold body part and the rotation-stopping part of the mold is not circular, so that the axial projection of the nut formed by injection molding in the mold is also not circular, thus the relative rotation of the nut and the mold can be limited, and the nut is pulled out of the mold by the cooperation of the core rod thread part and the nut thread part.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of refrigeration control, and in particular to a mold, a nut, a manufacturing method of the nut, and an electronic expansion valve using the nut. BACKGROUND

[0002] In a refrigeration system, an electronic expansion valve is usually needed, and in the electronic expansion valve, a nut can be formed by injection molding using resin or other materials. The nut needs to be demolded from the mold after injection molding.

[0003] At present, a positioning rod is usually arranged on the mold, the nut is injection molded together with a nut insert, the nut insert is provided with a through hole, and the positioning rod is arranged in the through hole to limit the circumferential rotation of the nut. Meanwhile, the core rod is rotated, the core rod and the threaded pair of the nut are matched, and the nut is demolded from the mold. SUMMARY

[0004] The present application aims to provide a mold which can realize a new demolding mode of the nut from the mold.

[0005] To achieve the above-mentioned purpose, the following technical solutions are adopted:

[0006] A mold comprises a first mold body, a second mold body, a core rod, and a feeding part. The mold comprises a mold cavity, and the feeding part comprises a feeding channel which is communicated with the mold cavity.

[0007] The second mold body comprises a second mold body matching hole part which is located at the opposite lower part of the second mold body. The core rod comprises a first core rod matching part which is gap-matched with the second mold body matching hole part.

[0008] The core rod comprises a core rod threaded part which comprises a core rod threaded large-diameter part and a core rod threaded small-diameter part.

[0009] The second mold body comprises a second mold body body part and a rotation-stopping part. In the axial direction, the outer contour of the projection formed by the second mold body body part and the rotation-stopping part is not circular.

[0010] In addition, a nut for an electronic expansion valve comprises a nut body and a demolding part. In the axial direction, the outer contour of the projection formed by the nut body and the demolding part is not circular.

[0011] The mold provided by the present application has the following advantages: the axial projection outer contour of the second mold body body part and the rotation-stopping part of the mold is not circular, so the axial projection outer contour of the nut injection molded in the mold is also not circular. Therefore, the relative rotation of the nut and the mold can be limited, and the nut is demolded from the mold under the cooperation of the core rod threaded part and the nut threaded part.

[0012] The present invention also provides a nut, a method for manufacturing the nut, and an electronic expansion valve using the nut. Since the above-mentioned mold has the above-mentioned technical effects, the nut manufactured using the mold and the manufacturing method used to manufacture the nut should also have similar technical effects, so they will not be described in detail here. Attached Figure Description

[0013] Figure 1 A cross-sectional schematic diagram of the electronic expansion valve body is provided for the present invention;

[0014] Figure 2 for Figure 1 Schematic diagram of the middle nut assembly;

[0015] Figure 3 A schematic diagram of the structure of the mandrel of the mold provided by the present invention;

[0016] Figure 4 A cross-sectional schematic diagram of the mold provided by the present invention;

[0017] Figure 5 A cross-sectional view of the mold with the connector placed in the present invention before mold closing;

[0018] Figure 6 A cross-sectional schematic diagram of the mold with the connector placed in it, provided by the present invention, after the mold is closed;

[0019] Figure 7 for Figure 6 A cross-sectional schematic diagram of the mold for the injection-molded nut;

[0020] Figure 8 for Figure 7 A cross-sectional view showing the middle mold separated;

[0021] Figure 9 for Figure 7 A cross-sectional view of the nut as it is ejected from the mold;

[0022] Figure 10 for Figure 7 A cross-sectional view of the nut after it has been removed from the mold;

[0023] Figure 11 for Figure 4 A cross-sectional view of the second phantom in another direction;

[0024] Figure 12 A top view of the second mold body and nut in another structure;

[0025] Figure 13 A top view of a second model with a different structure;

[0026] Figures 1-13 The annotations in the accompanying drawings are explained as follows:

[0027] Valve seat screw assembly 1; screw rod 11; screw rod outer fitting part 111; screw rod threaded part 112; screw rod containing part 113; screw rod abutting part 114; screw rod inner fitting part 115; valve needle 12; valve needle main body part 121; valve needle diameter expanding part 122; nut 2; nut screw guide part 21; nut threaded part 22; large diameter part 221; small diameter part 222; nut valve needle guide part 23; nut fitting part 24; nut groove part 25; nut pressure part 26; nut flow-through hole part 27; nut extrusion part 28; nut protrusion part 281; nut recess part 282; valve seat 3; valve seat fitting part 31; flow-through part 32; valve port 34; valve port sealing part 341; connecting body 4; fixed rod 5; spring 6; steel ball 7; magnetic rotor 8; housing 9; fixed frame 10; stop assembly 20; helical guide rail 201; sliding ring 202; stop rod 203; first connecting pipe part 30; second connecting pipe part 40; mold 50; first mold body 501; first mold body fitting hole part 5011; second mold body 502; second mold body fitting hole part 5021; second mold body main body part 5022; rotation stopping part 5023; second mold body step part 5024; core rod 503; first core rod fitting part 5031; core rod threaded part 5032; core rod threaded large diameter part 50321; core rod threaded small diameter part 50322; second core rod fitting part 5033; third core rod fitting part 5034; fourth core rod fitting part 5035; feeding part 504; first cavity A; second cavity B; balance part C; mold cavity 50A. DETAILED DESCRIPTION

[0028] Example 1

[0029] In order to make the technical personnel in the art better understand the technical solutions of the present application, the present application will be further described in detail below in combination with the drawings and specific embodiments.

[0030] The "several" described herein refers to an indefinite number of multiple, usually more than two; and when "several" is used to represent the number of several components, it does not mean that the number of these components is the same.

[0031] The "first", "second", "third" and the like described herein are only for the convenience of describing structures or components that are the same or similar to two or more structures, and do not represent any special limitation on the order.

[0032] Please refer to Figures 1-2 , Figure 1 The present application provides a cross-sectional view of the valve body of the electronic expansion valve, 2 is Figure 1 the structure diagram of the nut assembly.

[0033] In one embodiment, the electronic expansion valve provided by the present application comprises a valve body and a stator coil (not shown in the figure). The valve body comprises a valve needle and screw rod assembly 1, a nut 2, a valve seat 3, a magnetic rotor 8, and a housing 9. The stator coil of the electronic expansion valve is connected to a drive controller. After the drive controller is powered and senses the working conditions of the refrigeration system environment, it sends a pulse drive signal to the stator coil. The stator coil generates a periodically changing magnetic field, thereby driving the magnetic rotor 8 of the electronic expansion valve to rotate forward or backward. The magnetic rotor 8 is fixedly connected to the screw rod 11, and the magnetic rotor 8 rotates synchronously to drive the screw rod 11 to rotate.

[0034] The screw rod 11 of the valve needle and screw rod assembly 1 is provided with a screw rod threaded portion 112, which is an external threaded structure. The nut 2 has a hollow structure and is provided with a nut threaded portion 22, which is an internal threaded structure. The screw rod threaded portion 112 and the nut threaded portion 22 are engaged, and the nut 2 is fixedly installed on the valve seat 3. In this way, while the magnetic rotor 8 rotates, the screw rod 11 moves axially due to the threaded pair structure on the screw rod 11 and the nut 2, thereby driving the valve needle 12 of the valve needle and screw rod assembly 1 to realize the opening and closing action of the valve port 34.

[0035] The first connecting pipe portion 30 and the second connecting pipe portion 40 are fixedly installed on the valve seat 3 and serve as the inflow or outflow channel of the fluid medium of the electronic expansion valve, and are generally used for connection with the system pipeline when the electronic expansion valve is installed in a refrigeration or heating system such as an air conditioner. The valve seat 3 is provided with a valve port 117 at a position substantially at the center of the second connecting pipe portion 40, and the upper side edge of the valve port 117 is provided with a valve port sealing portion 1171.

[0036] In this embodiment, the nut 2 is made of plastic and is injection molded from a resin material, and the nut 2 is fixedly connected with a connecting body 4, which can be embedded in the nut.

[0037] The nut 2 provided by this embodiment is generally hollow and comprises a nut screw rod guide portion 21, a nut threaded portion 22, and a nut valve needle guide portion 23. In the axial direction, the nut screw rod guide portion 21 is higher than the nut threaded portion 22, and the nut valve needle guide portion 23 is lower than the nut threaded portion 22.

[0038] Correspondingly, the valve needle and screw rod assembly 1 provided by this embodiment comprises a valve needle 12 and a screw rod 11, which are limitingly connected, i.e., the valve needle 12 can move within a certain range but cannot move out of the limit of the screw rod 11.

[0039] After the nut 2 and the valve needle and screw rod assembly 1 are engaged by threads, the nut screw rod guide portion 21 is gap-fitted with the screw rod outer fitting portion 111, and the nut valve needle guide portion 23 is gap-fitted with the valve needle main body portion 121.

[0040] By the above arrangement, when the valve needle screw assembly 1 is driven to rotate by the magnetic rotor 8 and moves in the axial direction of the valve needle screw assembly 1, the screw rod 11 is guided and aligned by the screw rod guiding portion 111 of the nut, and the valve needle 12 is guided and aligned by the valve needle screw guiding portion 21, so that the valve needle screw assembly 1 is not easy to be deflected, and the working stability of the electronic expansion valve can be improved.

[0041] In addition, when the valve needle screw assembly 1 is assembled, the screw rod outer matching portion 111 on the outer periphery of the screw rod 11 can also guide before the nut screw thread portion 22 and the screw rod thread portion 112 are engaged, so that the assembly of the valve needle screw assembly 1 is more convenient, and the situation that the electronic expansion valve is invalid or the service life is reduced due to deflection of the valve needle screw assembly 1 and the nut 2 during assembly can be reduced, and the working life and reliability of the electronic expansion valve can be improved.

[0042] In the embodiment, the screw rod 11 includes a screw rod containing portion 113, a screw rod abutting portion 114, and a screw rod inner matching portion 115, the screw rod abutting portion 114 is located between the screw rod containing portion 113 and the screw rod inner matching portion 115, and the inner diameter of the screw rod containing portion 113 is greater than the inner diameter of the screw rod inner matching portion 115, the valve needle 12 is provided in the screw rod 11, and the valve needle 11 includes a valve needle expanding diameter portion 122, which is located at the upper end of the valve needle 11 and can abut against the screw rod abutting portion 114 to prevent the valve needle 12 from being pulled out of the screw rod 11.

[0043] When the axial projection of the screw rod expanding diameter portion 122 is circular, the outer diameter thereof is smaller than the inner diameter of the screw rod containing portion 113, so that the valve needle 12 can be inserted into the internal cavity of the screw rod 11 from the upper end of the screw rod 11, the screw rod containing portion 113 and the valve needle expanding diameter portion 122 are clearance-fitted, and the screw rod containing portion 113 can guide the valve needle 12 when the valve needle 12 moves within the range defined by the screw rod 11, so that the stability of the valve needle 12 relative to the screw rod 11 can be improved.

[0044] Meanwhile, the outer diameter of the valve needle expanding diameter portion 122 is greater than the inner diameter of the screw rod inner matching portion 115, and when the valve needle 12 is to pass through the screw rod 12, the valve needle expanding diameter portion 122 can abut against the screw rod abutting portion 114 to limit the valve needle 12 from being pulled out of the screw rod 11, and in addition, the valve needle main body portion 121 and the screw rod inner matching portion 115 are clearance-fitted, and the screw rod inner matching portion 115 can guide the valve needle 12 when the valve needle 12 is actuated up and down, so that the stability of the valve needle 12 relative to the screw rod 11, the coaxiality of the valve needle 12 relative to the central axis of the valve port 34, and the eccentric wear of the valve needle 12 can be improved.

[0045] The valve needle main body part 121 and the valve needle diameter expansion part 122 are guided by the screw rod 11 at the same time, so that the stability of the valve needle 12 relative to the screw rod 11 during movement can be further improved, and the coaxiality of the valve needle 12 and the central axis of the valve port can be more easily ensured.

[0046] In addition, the electronic expansion valve provided by the embodiment further comprises a fixing rod 5, a spring 6 and a steel ball 7. Specifically, the fixing rod 5 is arranged in the screw rod accommodating part 113 and is fixedly connected with the screw rod 11. The space in the screw rod accommodating part 113 is provided with the spring 6 and the steel ball 7. The steel ball 7 is located above the spring 6, the upper end of the spring 6 abuts against the steel ball 7, the steel ball 7 abuts against the fixing rod 5, the lower end of the spring 6 abuts against the upper surface of the valve needle diameter expansion part 122, and the valve needle 12 is subjected to the elastic load of the spring 6.

[0047] The fixing rod 5 is fixedly connected with a screw guide rail 201. A sliding ring 202 is matched with the screw guide rail 201, that is, the sliding ring 202 slides in the annular guide rail of the screw guide rail 201. A stop rod 203 is fixedly connected with the upper end of the shell 9. The stop rod 203 has a cross section substantially in the shape of an inverted “L”. The stop rod 203, the sliding ring 202 and the screw guide rail 201 are matched to limit the range of the up-and-down movement of the screw rod 11. The stop rod 203, the sliding ring 202 and the screw guide rail 201 constitute a stop assembly of the electronic expansion valve.

[0048] In addition, the electronic expansion valve provided by the embodiment further comprises a first cavity A and a second cavity B. The valve seat 3, the nut 2, the fixing frame 10 and the shell 9 substantially define the first cavity A. The valve seat 3 and the nut 2 substantially define the second cavity B. Of course, it can be understood that the first cavity A and the second cavity B can also be defined by different conditions from the embodiment. For example, the valve seat 3 is directly fixedly connected with the shell 9. At this time, the valve seat 3, the nut 2 and the shell 9 substantially define the first cavity A.

[0049] The electronic expansion valve provided by the embodiment comprises a nut matching part 24 of the nut 2, which is located below the connecting body 4. The valve seat 3 comprises a valve seat matching part 31. The nut matching part 24 is arranged in the valve seat matching part 31. At this time, the projection of the nut matching part 24 and the valve seat matching part 31 in the axial direction along the central axis of the electronic expansion valve has an intersection.

[0050] In addition, the valve seat 3 is provided with a flow-through part 32, which can be a through hole or an indentation penetrating through the valve seat 3. A balance part C is arranged between the nut matching part 24 and the valve seat matching part 31. The balance part C is in communication with the flow-through part 32. The first cavity A and the second cavity B can be in communication through the balance part C and the flow-through part 32.

[0051] Thus, the electronic expansion valve can balance the pressure in the first cavity A and the second cavity B through the balance part C and the flow part 32 when the refrigerant flows, thereby improving the working stability of the electronic expansion valve.

[0052] Specifically, the balance part C can be implemented in various ways. For example, the nut 2 is provided with a nut groove part 25, which is a groove structure formed by the surface of the nut 2 being radially recessed. The nut groove part 25 is in communication with the flow part 32, and the refrigerant in the first cavity A and the second cavity B can balance through the nut groove part 25. For another example, the valve seat 3 is provided with a valve seat groove part 22, which is a groove structure formed by the surface of the valve seat 3 being radially recessed. The valve seat groove part 33 can be in communication with the flow part 32, and the pressure in the first cavity A and the second cavity B can balance through the valve seat groove part 33. For another example, the nut matching part 24 and the valve seat matching part 31 are gap matched, the gap can be in communication with the flow part 32, and the pressure in the first cavity A and the second cavity B can balance through the gap between the nut matching part 24 and the valve seat matching part 31.

[0053] It is worth noting that the three conditions of the nut groove part 25 and the valve seat groove part 33, and the gap matching between the nut groove part 25 and the valve seat matching part 31 are not in conflict. For example, when the valve seat 3 is provided with the valve seat groove part 33, the nut 2 is provided with the nut groove part 25, and the gap matching between the valve seat matching part 31 and the nut matching part 24 is provided at the same time, the pressure in the first cavity A and the second cavity B can still balance. The first cavity A and the second cavity B balance, and only one or more of the valve seat groove part 33, the nut groove part 25, and the gap matching between the valve seat matching part 31 and the nut matching part 24 need to be provided.

[0054] In addition, the electronic expansion valve provided by the embodiment further comprises a nut pressure part 26 and a nut flow hole part 27. Specifically, the nut pressure part 26 is located above the nut valve needle guide part 23 in the axial position, below the nut threaded part 22. The inner diameter of the nut pressure part 26 is greater than the outer diameter of the valve needle body part 121. At this time, a certain space is formed between the nut pressure part 26 and the valve needle body part 122. In addition, the nut flow hole part 27 comprises a through hole penetrating the inner and outer surfaces of the nut 2, and the nut flow hole part 27 communicates the nut pressure part 26 and the above-mentioned balance part C.

[0055] Through the above arrangement, the pressure inside the nut 2 can balance with the pressure outside the nut 2 through the nut flow hole part 27, so as to improve the working stability of the electronic expansion valve.

[0056] The working principle of the electronic expansion valve provided by the embodiment is as follows:

[0057] When the flow rate of the electronic expansion valve is gradually reduced from the maximum opening, the magnetic rotor 8 begins to rotate under the influence of the magnetic field of the stator housing, and the valve needle screw assembly 1 fixedly connected with the magnetic rotor 8 also rotates synchronously. Since the nut 2 is fixedly connected with the valve seat 3 through the connecting body 4, and the screw thread part 112 is engaged with the nut thread part 22, at this time the screw rod 11 begins to move axially downward.

[0058] At this time, the valve needle 12 is movably limited with the screw rod 11, that is, the valve needle 12 is affected by the spring force, and the valve needle expansion diameter part 122 abuts against the screw rod abutting part 114. When the screw rod 11 moves downward, the valve needle 12 also moves downward synchronously.

[0059] With the gradually increasing stroke of the downward movement of the valve needle screw assembly 1, the valve needle 12 begins to abut against the valve port sealing part 341 of the valve port 34, and the flow rate is closed.

[0060] When the screw rod 11 further moves downward, at this time the valve needle 12 abuts against the valve port 34, and the valve needle 12 cannot further move downward with the screw rod 11. At this time, the valve needle expansion diameter part 121 and the screw rod abutting part 114 change from the abutting state to the separated state, and the spring 6 is further compressed. With the increasing compression amount of the spring 6, the pressure of the valve needle 12 on the valve port 34 also gradually increases, so as to ensure sufficient valve closing force of the valve needle 12.

[0061] During the axial movement of the screw rod 11, the screw guide rail 201 and the sliding ring 202 also move relatively, that is, the sliding ring 202 moves circumferentially along the guide rail of the screw guide rail 201 around the fixed rod due to the contact of one end of the sliding ring 202 with the stop rod 203. When the sliding ring 202 rotates to the limiting part at the upper end of the screw guide rail 201, the sliding ring 202 is limited from further rotating, so that the valve needle screw assembly 1 is also limited from further moving downward, and the spring 6 is compressed to the maximum position. At this time, the pressure of the valve needle 12 on the valve port 34 is the maximum.

[0062] Embodiment 2

[0063] Therefore, the application also provides a mold 50 for injection molding the above nut 2.

[0064] Please refer to Figures 3-13 , Figure 3 the structure diagram of the core rod of the mold provided by the application, Figure 4 the cross-sectional diagram of the mold provided by the application, Figure 5 the cross-sectional diagram of the mold provided by the application before the mold is closed, Figure 6 the cross-sectional diagram of the mold provided by the application after the mold is closed, Figure 7 is Figure 6 the cross-sectional diagram of the mold in which the nut is injection molded,Figure 8 Fig. 1 is a perspective view of a nut according to the present application; Figure 7 Fig. 2 is a cross-sectional view of the nut according to the present application; Figure 9 Fig. 3 is a cross-sectional view of the nut according to the present application; Figure 7 Fig. 4 is a cross-sectional view of the nut according to the present application; Figure 10 Fig. 5 is a cross-sectional view of the nut according to the present application; Figure 7 Fig. 6 is a cross-sectional view of the nut according to the present application; Figure 11 Fig. 7 is a cross-sectional view of the nut according to the present application; Figure 4 Fig. 8 is a cross-sectional view of the nut according to the present application; Figure 12 Fig. 9 is a top view of the nut according to the present application; Figure 13 Fig. 10 is a top view of the nut according to the present application;

[0065] Specifically, the mold 50 according to the present application comprises a first mold body 501, a second mold body 502, a core rod 503 and a feeding part 504, the mold 50 comprises a mold cavity 50A, the feeding part 504 comprises a feeding channel, the mold cavity 50A is communicated with the feeding channel, and the injection material can enter the mold cavity 50A through the feeding part 504 to complete the injection. In the present embodiment, the feeding part 504 is located at the upper end of the second mold body 502 and is in the form of a groove. It can be understood that the feeding part 504 can also be located at the first mold body 501 and can also be in the form of a channel, as long as the feeding channel of the feeding part 504 can be communicated with the mold cavity 50A to enable the injection material to enter the mold cavity 50A smoothly.

[0066] The second mold body 502 comprises a second mold body fitting hole part 5021, the second mold body fitting hole part 5021 is located at the relatively lower part of the second mold body 502, and the core rod 503 is arranged in the second mold body fitting hole part 5021. The core rod 503 further comprises a first core rod fitting part 5031, the first core rod fitting part 5031 is gap-fitted with the second mold body fitting hole part 5021, and the core rod 503 can rotate relatively freely during the demolding of the nut 2, so as to facilitate the subsequent demolding of the nut 2 from the second mold body 502. At the same time, in order to reduce the risk of leakage of the injection material from the gap between the first core rod fitting part 5031 and the second mold body fitting hole part 5021, the gap between the first core rod fitting part 5031 and the second mold body 502 is preferably within the range of 0.04 mm. In addition, the core rod 503 comprises a core rod threaded part 5032.

[0067] In addition, the second mold body 502 comprises a second mold body body part 5022 and a rotation-stopping part 5023, and the projection of the combination of the second mold body body part 5022 and the rotation-stopping part 5023 in the axial direction is not circular in the outer contour. The rotation-stopping part 5023 extends through the upper end surface of the second mold body 502, so that the nut 2 is not blocked by the second mold body 502 during the demolding process. It is worth noting that the upper end surface of the second mold body 502 is not necessarily a horizontal surface.

[0068] By the above setting, the axial projection of the nut 2 is not circular, and the nut 2 is injection molded to form a protruding portion 28 at the rotation-stopping portion 5023, and the projection of the nut body and the protruding portion 28 is not circular. The nut 2 is formed with a nut threaded portion 22, and the threads on the nut threaded portion 22 are engaged with the threads on the core rod threaded portion 5032. When the nut 2 needs to be demolded, the core rod 503 is rotated, the protruding portion 28 of the nut 2 cooperates with the rotation-stopping portion 5023, so that the nut 2 cannot rotate relative to the valve seat 3, and the nut 2 is axially moved by the action of the threaded pair when the core rod 503 is rotated, so that the nut 2 is demolded from the mold 50.

[0069] Specifically, a motor can be arranged below the mold 50, and the motor cooperates with the core rod 503. When the nut needs to be demolded, the motor is energized, and the motor rotates to drive the core rod 503 to rotate synchronously. When the core rod 503 rotates, the nut 2 is axially moved, so that the nut 2 is demolded from the mold 50. Of course, other ways can be used to rotate the core rod 503, such as manual operation and other conventional means.

[0070] The number of rotation-stopping portions 5023 is preferably two or more and symmetrically arranged, and the number of protruding portions 28 is two or more and symmetrically arranged.

[0071] Specifically, the second mold body 502 includes a second mold body groove portion 50231, which is radially recessed relative to the inner wall of the second mold body body portion (5022) in a direction away from the central axis of the mold, and the second mold body groove portion 50231 extends through the upper end face of the second mold body 502 so that the nut 2 can be smoothly demolded from the mold 50. At this time, it can be understood that the nut 2 will form a nut protruding portion 281, which extends radially away from the central axis of the nut body toward the outer wall of the nut body. The nut protruding portion 281 cooperates with the second mold body groove portion 50231 to limit the relative rotation of the nut 2 and the second mold body 502. At this time, the rotation-stopping portion 5023 includes the second mold body groove portion 50231.

[0072] Of course, the rotation-stopping portion 5023 can be in other forms, for example, please refer to Figure 12, the second mold body 502 includes a second mold body protruding portion 50232 which protrudes radially toward the direction close to the central axis of the mold relative to the inner wall of the second mold body portion 5022, at this time, it can be understood that the nut 2 will form a nut recessed portion 282 which recesses radially toward the central axis of the nut 2 toward the outer wall of the nut body. The nut recessed portion 282 cooperates with the second mold body protruding portion 50232 to limit the relative rotation of the nut 2 and the second mold 50, at this time, the rotation stopping portion 5023 includes the second mold body protruding portion 50232; for example Figure 13 The second mold 502 of the present application, the inner cavity of the second mold 502 is substantially a regular octagonal structure, at this time, the second mold body portion 5022 is substantially an inscribed circle structure of the regular octagonal structure (as shown by the dashed line in the figure), and the rotation stopping portion 5023 is substantially a part of the regular octagonal structure which extends radially along the inscribed circle toward the direction away from the central axis of the second mold 502, at this time, the projection of the rotation stopping portion 5023 and the second mold body portion 5022 in the axial direction is not circular, which can limit the relative rotation of the nut 2 and the second mold 50.

[0073] It is worth mentioning that the present application does not limit the form and number of the rotation stopping portion 5023, for example, the second mold body groove portion 50231 and the second mold body protruding portion 50232 can be provided on one mold at the same time, at this time, the second mold body groove portion 50231 is part of the rotation stopping portion 5023 but not all, and the second mold body groove portion 50231 and the second mold body protruding portion 50232 do not conflict.

[0074] In addition, the core rod 503 provided by the embodiment includes a second core rod cooperating portion 5033 which is located below the core rod threaded portion 5032 in the axial direction, the core rod threaded portion 5032 includes a core rod threaded large diameter portion 50321 and a core rod threaded small diameter portion 50322, the core rod threaded large diameter portion 50321 is substantially the largest outer diameter of the core rod threaded portion 5032, and the core rod threaded small diameter portion 50322 is substantially the smallest outer diameter of the core rod threaded portion 5032, at this time, the outer diameter of the second core rod cooperating portion 5033 is greater than or equal to the outer diameter of the core rod threaded large diameter portion 50321.

[0075] The second core rod cooperating portion 5033 and the second mold 502 substantially form a nut screw rod guide portion 21 of the nut 2, when the screw rod 11 moves in the axial direction, it can be guided and aligned by the nut screw rod guide portion 21, so that the valve needle screw rod assembly 1 is not easy to be deflected.

[0076] Since the nut 2 is pulled out from the core rod 503 from bottom to top when demolding, and the second core rod fitting part 5033 is located below the core rod threaded part 5032 in the axial direction, if the diameter of the second core rod fitting part 5033 is set to be smaller than the diameter of the core rod threaded large diameter part 50321, the nut screw rod guide part 21 will abut against the core rod threaded part 5032, and the nut 2 cannot be smoothly pulled out from the core rod 503.

[0077] In addition, the core rod 503 provided by the embodiment comprises a third core rod fitting part 5034, which is located above the core rod threaded part 5032 in the axial direction, and the diameter of the third core rod fitting part 5034 is smaller than or equal to the diameter of the core rod threaded small diameter part 50322.

[0078] The third core rod fitting part 5034 and the second mold body 502 substantially form the nut valve needle guide part 23 of the nut 2, and the valve needle 12 can be guided and aligned by the nut valve needle guide part 23 when moving in the axial direction, so that the valve needle 12 is not easy to be deflected relative to the central axis of the valve body, and the valve needle 12 is more likely to be aligned with the valve port 34.

[0079] The second mold body 502 provided by the embodiment further comprises a second mold body step part 5023, which is axially recessed relative to the upper wall of the second mold body 502 towards the direction close to the bottom of the mold 50, and the step part 5023 is in communication with the mold cavity 50A.

[0080] Specifically, before the first mold body 501 and the second mold body 502 are combined, a connecting body 4 substantially in the shape of a ring can be placed in the second mold body step part 5023, and after the first mold body 501 and the second mold body 502 are combined, the connecting body 4 is fixed to the second mold body step part 5023 and located between the first mold body 501 and the second mold body 502, and at least part of the connecting body 4 is located in the mold cavity 50A, at this time, the nut 2 formed by injection molding is fixedly connected with the connecting body 4 due to inlaying. The connecting body 4 can be conveniently fixed and installed on the valve seat 3 subsequently.

[0081] In addition, the first mold body 501 further comprises a first mold body fitting hole part 5011, which can be a through hole or a blind hole, and the core rod 503 is arranged in the first mold body fitting hole part 5011, and the core rod 503 comprises a fourth core rod fitting part 5035.

[0082] Since the nut 2 is pulled out from the core rod 503 from bottom to top when demolding, and the fourth core rod fitting part 5035 is located above the core rod threaded part 5032 in the axial direction, if the diameter of the fourth core rod fitting part 5035 is set to be greater than the diameter of the core rod threaded small diameter part 50322, the nut threaded part 22 will abut against the fourth core rod fitting part 5035, and the nut 2 cannot be smoothly pulled out from the core rod 503.

[0083] The fourth core rod matching part 5035 can reduce the offset of the core rod 503 during injection molding, improve the reliability of the nut 2 injection molding, and further transitionally match or clearance match the fourth core rod matching part 5035 and the first mold body matching hole part 5011. When the nut 2 is injection molded, the air in the mold cavity 50A can leave the mold cavity 50A from the gap between the fourth core rod matching part 5035 and the first mold body matching hole part 5011, so as to achieve better injection molding effect.

[0084] The diameter of the third core rod matching part 5033 can be equal to the diameter of the fourth core rod matching part 5034.

[0085] Embodiment 3

[0086] In order to make the electromagnetic coil have the above structure, the application provides a manufacturing method of an electromagnetic coil, comprising the following steps:

[0087] Step S1: configuring a mold 50, the mold 50 comprising a first mold body 501 and a second mold body 502, a core rod 503 and a feeding part 504, the mold 50 comprising a mold cavity 50A, the feeding part 504 comprising a feeding channel, the feeding channel being communicated with the mold cavity 50A;

[0088] The second mold body 502 comprises a second mold body matching hole part 5021, the core rod 503 is arranged in the second mold body matching hole part 5021, and the first core rod matching part 5031 clearance matches the second mold body matching hole part 5021.

[0089] The core rod 503 comprises a core rod threaded part 5032, the core rod threaded part 5032 comprising a core rod threaded large diameter part 50321 and a core rod threaded small diameter part 50322.

[0090] The second mold body 502 comprises a second mold body body part 5022 and a rotation stopping part 5023, and the projection outer contour composed of the second mold body body part 5022 and the rotation stopping part 5023 in the axial direction is not circular.

[0091] Step S2: clamping, making the injection molding material enter the feeding part 504, the injection molding material entering the mold cavity 50A through the feeding channel, implementing injection molding, and forming the nut 2 after the injection molding material is cooled.

[0092] Step S3: separating the first mold body 501 and the second mold body 502, rotating the core rod 503, and making the nut 2 be taken out.

[0093] 10. The method for manufacturing the nut of the electronic expansion valve according to claim 8, characterized in that, before the step S2, it further comprises a step S1-1: the second mold body 502 is provided with a second mold body step portion 5024, the second mold body step portion 5024 is axially recessed towards the direction close to the bottom of the second mold 502 relative to the upper wall of the second mold 502, and the second mold body step portion 5024 is communicated with the mold cavity 50A.

[0094] The connecting body 4 is arranged on the second mold body step portion 5024, and the connecting body 4 is at least partially located in the mold cavity 50A.

[0095] It should be noted that the terms of up, down, left, right and the like mentioned in the specification are all based on the drawings as the reference, which are introduced for the convenience of description; and the ordinal numbers in the component names, such as "first" and "second", are also introduced for the convenience of description, and do not mean any limitation on the order of the components. The communication mentioned in the specification includes direct communication and indirect communication, and the abutment mentioned in the specification includes direct abutment and indirect abutment.

[0096] The above is only the preferred embodiment of the present application, and it should be noted that, for those skilled in the art, some improvements and refinements can be made without departing from the principles of the present application, and these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. A mold (50), characterized in that, The mold (50) includes a first mold body (501), a second mold body (502), a mandrel (503), and a feeding part (504). The mold (50) includes a mold cavity (50A), and the feeding part (504) includes a feeding channel, which is connected to the mold cavity (50A). The second mold (502) includes a second mold mating hole (5021), which is located at the lower part of the second mold (502). The mandrel (503) includes a first mandrel mating part (5031), which is in clearance fit with the second mold mating hole (5021). The mandrel (503) includes a mandrel threaded portion (5032), which includes a mandrel threaded large diameter portion (50321) and a mandrel threaded small diameter portion (50322). The second mold (502) includes a second mold body part (5022) and an anti-rotation part (5023). In the axial direction, the outer contour of the projection formed by the second mold body part (5022) and the anti-rotation part (5023) is not circular.

2. The mold according to claim 1, characterized in that, The anti-rotation part (5023) includes a second mold groove (50231), which is radially recessed relative to the inner wall of the second mold body part (5022) in a direction away from the central axis of the mold (50), and the second mold groove (50231) extends and penetrates the upper end face of the second mold (502).

3. The mold according to claim 1, characterized in that, The anti-rotation part (5023) includes a second mold body protrusion (50232), which protrudes radially relative to the inner wall of the second mold body part (5022) toward the central axis of the mold.

4. The mold according to any one of claims 1-3, characterized in that, The mandrel (503) includes a second mandrel mating portion (5033), the diameter of which is greater than or equal to the diameter of the major diameter portion (50321) of the mandrel thread.

5. The mold according to any one of claims 1-3, characterized in that, The mandrel (503) includes a third mandrel mating part (5034), the diameter of which is less than or equal to the diameter of the minor diameter of the mandrel thread (50322).

6. The mold according to any one of claims 1-3, characterized in that, The second mold body includes a second mold body step portion (5024), which is axially recessed relative to the upper wall of the second mold body (502) toward the bottom of the mold, and the second mold body step portion (5024) communicates with the mold cavity (50A).

7. The mold according to any one of claims 1-3, characterized in that, The first mold body (501) includes a first mold body mating hole (5011), which is a blind hole or a through hole. The mandrel (503) includes a fourth mandrel mating part (5035), the diameter of which is less than or equal to the diameter of the minor diameter of the mandrel thread (50322). The fourth mandrel mating part (5035) is clearance-fitted or transition-fitted with the first mold body mating hole (5011).

8. A method for manufacturing a nut for an electronic expansion valve, using the mold described in any one of claims 1-7, characterized in that, Includes the following steps: Step S1: Configure the mold (50), the mold (50) includes a first mold body (501) and a second mold body (502), a mandrel (503) and a feeding part (504), the mold (50) includes a mold cavity (50A), the feeding part (504) includes a feeding channel, and the feeding channel is connected to the mold cavity (50A); The second mold body (502) includes a second mold body mating hole (5021), and the mandrel (503) passes through the second mold body mating hole (5021). The first mandrel mating part (5031) and the second mold body mating hole (5021) are in clearance fit. The mandrel (503) includes a mandrel threaded portion (5032), which includes a mandrel threaded large diameter portion (50321) and a mandrel threaded small diameter portion (50322). The second mold (502) includes a second mold body part (5022) and an anti-rotation part (5023). In the axial direction, the outer contour of the projection of the second mold body part (5022) and the anti-rotation part (5023) is not circular. Step S2: Close the mold, allowing the injection material to enter the feed section (504). The injection material enters the mold cavity 50A through the feed channel and performs injection molding. After the injection material cools down, it forms a nut (2). Step S3: Separate the first mold (501) and the second mold (502), and rotate the mandrel (503) to dislodge the nut (2).

9. The method for manufacturing the nut of the electronic expansion valve according to claim 8, characterized in that, Before step S2, step S1-1 is also included: the second mold body (502) is provided with a second mold body step portion (5024), the second mold body step portion (5024) is axially recessed relative to the upper wall of the second mold body (502) toward the bottom of the second mold body (502), and the second mold body step portion (5024) is in communication with the mold cavity (50A). A connector (4) is configured, the connector (4) being placed on the step portion (5024) of the second mold body, and the connector (4) being at least partially located in the mold cavity (50A).

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