An electromagnetic driving assembly and a forming process thereof

Abstract

An electromagnetic driving assembly and a forming process thereof, wherein the electromagnetic driving assembly comprises a magnetic conductor, a coil assembly and a push rod, the coil assembly comprises a coil framework, the coil framework has a through hole, the axial two ends of the coil framework are provided with magnetic conductive sleeves, the inner diameter of the magnetic conductive sleeve is larger than the inner diameter of the through hole, a plane perpendicular to the axial direction of the coil assembly is defined as a projection plane, in the assembled state, the orthographic projection of the magnetic conductive sleeve on the projection plane is located outside the orthographic projection of the through hole on the projection plane, and the push rod is installed in the through hole. In the present application, the magnetic conductive sleeve is located radially outside the through hole, the magnetic conductive sleeve does not affect the through hole, the push rod can be directly installed in the through hole, a guide tube is not needed, the number of parts can be reduced, the structure and assembly process can be simplified, the production and assembly efficiency can be improved, the qualified rate of the product can be improved, the number of air gap layers between the coil framework and the push rod can be reduced, the magnetic resistance can be reduced, and the performance of the electromagnetic driving assembly can be improved.

Description

Technical Field

[0001] This invention relates to the field of electromagnetic drive technology, specifically to an electromagnetic drive assembly and its molding process. Background Technology

[0002] Please refer to Figure 1 , Figure 1 This is an exploded view of a conventional electromagnetic drive assembly.

[0003] Smart refrigerators and other smart home appliances generally use electromagnetic drive assemblies to control door opening, such as Figure 1 As shown, a conventional electromagnetic drive assembly includes a magnetic conductor 01, an encapsulation layer 02, an enameled wire 03, a coil frame 04, two magnetic sleeves 05, a guide tube 06, and a push rod 07. The coil frame 04 has a through hole. During assembly, both magnetic sleeves 05 are installed in the through hole of the coil frame 04. At this time, in order to ensure the smooth operation of the push rod 07, a guide tube 06, usually made of brass, is riveted into the through hole of the coil frame 04. Due to dimensional tolerances and other reasons, air gaps exist between the through hole of the coil frame 04 and the magnetic sleeves 05, between the magnetic sleeves 05 and the guide tube 06, and between the guide tube 06 and the push rod 07, which leads to increased magnetic resistance and thus affects the performance of the electromagnetic drive assembly. Summary of the Invention

[0004] The purpose of this invention is to provide an electromagnetic drive assembly and its molding process. The electromagnetic drive assembly has a simple structure and a small number of air gap layers between the coil frame and the push rod, which can reduce magnetic resistance and ensure the performance of the electromagnetic drive assembly.

[0005] To solve the above-mentioned technical problems, the present invention provides an electromagnetic drive assembly, including a magnetic conductor, a coil assembly, and a push rod. The coil assembly includes a coil frame with a through hole. Magnetic sleeves are provided at both axial ends of the coil frame. The inner diameter of the magnetic sleeves is larger than the inner diameter of the through hole. A surface perpendicular to the axial direction of the coil assembly is defined as a projection surface. In the assembled state, the orthographic projection of the magnetic sleeves on the projection surface is located outside the orthographic projection of the through hole on the projection surface. The push rod is installed inside the through hole.

[0006] In this embodiment of the invention, the magnetic sleeve is not installed inside the through hole of the coil frame, but is embedded in the coil frame. This installation method allows the magnetic sleeve to be located on the radially outer side of the through hole. In other words, the magnetic sleeve will not cause any sluggish operation due to being located on the radially inner side of the through hole.

[0007] This invention also provides a molding process for an electromagnetic drive assembly, applicable to the aforementioned electromagnetic drive assembly. The molding process includes the following steps: Step S1, configuring a mold; the mold includes an inner mold and an outer mold, the inner mold includes a first mold body and a second mold body connected axially, the first mold body and the second mold body each including a connected thick neck and a thin neck; Step S2, fitting two magnetic sleeves one-to-one onto the thick necks of the first mold body and the second mold body, such that the magnetic sleeve has a portion located outside the thin neck of the corresponding mold body, and there is a gap between the magnetic sleeve and the thin neck of the corresponding mold body; Step S3, installing the outer mold body onto the assembly of the inner mold and the magnetic sleeve, and performing injection molding to form an integral coil skeleton and the magnetic sleeve; Step S4, providing enameled wire and an encapsulation layer on the coil skeleton to form the coil assembly; Step S5, installing the coil assembly onto the magnetic conductor and installing the push rod.

[0008] Since the electromagnetic drive assembly described above already possesses the aforementioned technical effects, the molding process applicable to this electromagnetic drive assembly should also possess similar technical effects, and therefore will not be elaborated upon here. Attached Figure Description

[0009] Figure 1 An exploded view of a conventional electromagnetic drive assembly;

[0010] Figure 2 A schematic diagram of a specific embodiment of the electromagnetic drive assembly provided by the present invention;

[0011] Figure 3 for Figure 2 Exploded view;

[0012] Figure 4 A schematic diagram of a specific embodiment of the magnetic sleeve;

[0013] Figure 5 This is a diagram showing the installation structure of the magnetic sleeve and the inner mold.

[0014] Figure 6 This is a diagram showing the installation structure of the integrated magnetic sleeve and coil frame with the inner mold after injection molding.

[0015] Figure 7 This is a schematic diagram of the integrated magnetic sleeve and coil frame.

[0016] Figure 1 The annotations in the accompanying drawings are explained as follows:

[0017] 01 Magnetic conductor, 02 Encapsulation layer, 03 Enameled wire, 04 Skeleton, 05 Magnetic sleeve, 06 Guide tube, 07 Push rod.

[0018] Figure 2-7The annotations in the accompanying drawings are explained as follows:

[0019] 1. Magnetic conductor, 11. First magnetic part, 111. Through hole, 12. Second magnetic part;

[0020] 2. Coil assembly, 21. Coil frame, 211. Through hole, 22. Magnetic sleeve, 221. Material feeding structure, 222. Protrusion, 23. Enamelled wire, 24. Encapsulation layer;

[0021] 3. Putting rod;

[0022] 4 Inner mold, 41 First mold body, 42 Second mold body. Detailed Implementation

[0023] To enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0024] The terms "first" and "second" used in this article are used only for the convenience of describing two or more structures or components that are identical or similar in structure and / or function, and do not indicate any special limitation on order and / or importance.

[0025] Please refer to Figure 2-7 , Figure 2 This is a schematic diagram of a specific embodiment of the electromagnetic drive assembly provided by the present invention. Figure 3 for Figure 2 Exploded view, Figure 4 This is a structural diagram illustrating one specific embodiment of the magnetic sleeve. Figure 5 This is a diagram showing the installation structure of the magnetic sleeve and the inner mold. Figure 6 This is a diagram showing the integrated installation structure of the magnetic sleeve and coil frame with the inner mold after injection molding. Figure 7 This is a schematic diagram of the integrated magnetic sleeve and coil frame.

[0026] Example 1

[0027] like Figure 2 , Figure 3 As shown, the present invention provides an electromagnetic drive assembly, including a magnetic conductor 1, a coil assembly 2, and a push rod 3. The coil assembly 2 includes a coil component, which includes a coil frame 21 and an enameled wire 23 wound around the coil frame 21. The outer periphery of the coil component is also formed with an encapsulation layer 24 by injection molding. The coil frame 21 has a through hole 211, and magnetic sleeves 22 are provided at both axial ends of the coil frame 21. The inner diameter of the magnetic sleeves 22 is larger than the inner diameter of the through hole 211. The surface perpendicular to the axial direction of the coil assembly 2 is defined as the projection surface. In the assembled state, the orthographic projection of the magnetic sleeves 22 on the projection surface is located outside the orthographic projection of the through hole 211 on the projection surface. The push rod 3 is installed in the through hole 211.

[0028] In this embodiment of the invention, the magnetic sleeve 22 is not installed inside the through hole 211 of the coil frame 21, but is embedded in the coil frame 21. This installation method allows the magnetic sleeve 22 to be located on the radial outside of the through hole 211. In other words, the magnetic sleeve 22 will not affect the through hole 211.

[0029] In this way, the push rod 3 can be directly installed in the through hole 211 without the need for the guide tube in the prior art. On the one hand, it can reduce the number of parts, simplify the structure and assembly process, thereby improving production and assembly efficiency and improving the product qualification rate. On the other hand, it can also reduce the number of air gap layers between the coil frame 21 and the push rod 3, thereby reducing magnetic resistance and improving the performance of the electromagnetic drive assembly.

[0030] In a specific design, the magnetic sleeve 22 and the coil frame 21 can be an integral structure. Here, an integral structure means that they are formed as one piece during production. This can also eliminate the air gap layer between the magnetic sleeve 22 and the coil frame 21, so that the air gap layer between the coil frame 21 and the push rod 3 exists only between the hole wall of the through hole 211 and the outer wall of the push rod 3. This can further reduce magnetic resistance and improve the performance of the electromagnetic drive assembly.

[0031] The aforementioned integrated structure can be formed by injection molding process with a pre-embedded magnetic sleeve 22.

[0032] In detail, during production, a mold can be configured first. The mold may include an inner mold 4 and an outer mold (not shown in the figure). The inner mold 4 may include a first mold body 41 and a second mold body 42 that can be axially connected to facilitate the installation of the magnetic sleeve 22 and the adjustment of the axial dimensions of the coil frame 21 to be produced. The connection method of the first mold body 41 and the second mold body 42 can be a plug-in connection or a threaded connection, etc., which is not limited here; Figure 5 As shown, both the first mold body 41 and the second mold body 42 can include connected thick necks and thin necks. Two magnetic sleeves 22 can be fitted onto the thick necks of the first mold body 41 and the second mold body 42 in a corresponding manner, such that the magnetic sleeve 22 has a portion located outside the thin neck of the corresponding mold body; that is, a part of the magnetic sleeve 22 can be fitted onto the thick neck, and another part can be fitted onto the thin neck, creating a gap between the magnetic sleeve 22 and the thin neck. Then, an outer mold can be set outside the assembly formed by the inner mold 4 and the magnetic sleeves 22, and injection molding can be performed. Finally, an assembly can be formed as shown... Figure 6 , Figure 7 The integrated coil frame 21 and magnetic sleeve 22 shown have a gap between the part of the magnetic sleeve 22 located outside the neck and the neck, so that the injection molding liquid can be distributed on the inner and outer sides of the magnetic sleeve 22 to ensure a reliable connection between the magnetic sleeve 22 and the coil frame 21.

[0033] Furthermore, the sleeve wall of the magnetic sleeve 22 may be provided with a groove-shaped or hole-shaped material passage structure 221. Here, the hole-shaped refers to a material passage structure 221 that penetrates the corresponding sleeve wall and is circumferentially closed (e.g., Figure 4 As shown in the figure, the groove type here refers to the material passage structure 221 that does not penetrate the corresponding sleeve wall and / or is not circumferentially closed. During the injection molding operation, the injection liquid can be immersed in the material passage structure 221 to improve the connection reliability of the magnetic sleeve 22 and the coil frame 21.

[0034] Please continue to refer to this. Figure 4 The magnetic sleeve 22 may also be provided with an axially extending slit 223, which is mainly used to eliminate eddy currents under AC operating conditions.

[0035] In fact, besides the integrated design described above, the coil frame 21 and the magnetic sleeve 22 can also be manufactured separately and then assembled. For example, annular grooves can be provided at both axial ends of the coil frame 21, and then the magnetic sleeve 22 can be installed in the annular grooves. In the radial direction, the annular grooves can be isolated from the through hole 211.

[0036] In the assembled state, both magnetic sleeves 22 can have protrusions 222 that protrude from both ends of the coil frame 21 along the axial direction. The magnetic body 1 can include two magnetic walls that are arranged opposite to each other. Both magnetic walls can be provided with through holes 111. The two protrusions 222 can be fixed to the two through holes 111 one by one, thereby connecting the magnetic sleeves 22 and the magnetic body 1 together. This can further reduce magnetic leakage and improve the performance of the electromagnetic drive assembly.

[0037] The connection between the protrusion 222 and the through hole 111 can be varied and can be determined based on the actual situation. In one exemplary embodiment, the outer wall of the protrusion 222 can be joined with the wall of the through hole 111, and then fixed by welding, such as laser welding.

[0038] The magnetic conductor 1 may include a U-shaped first magnetic conductor 11 and a plate-shaped second magnetic conductor 12, which can be connected to each other to form a frame-shaped magnetic conductor 1. The bottom wall of the first magnetic conductor 11 and the second magnetic conductor 12 may both be provided with through holes 111. These two through holes 111 are used not only to connect with the protrusion 222, but also to pass through the push rod 3.

[0039] It is understandable that the split structure design of the magnetic conductor 1 is mainly to take into account the connection and cooperation between the two protrusions 222 and the two through holes 111. If the two protrusions 222 do not need to be inserted into the through holes 111 for welding, or if there are no protrusions 222, the magnetic conductor 1 can also be designed as an integral structure. Both of these are options that can be chosen in practical applications.

[0040] Example 2

[0041] The present invention also provides a molding process for an electromagnetic drive assembly, applicable to the electromagnetic drive assemblies described in various embodiments of Example 1. The molding process includes the following steps:

[0042] Step S1, configure the mold;

[0043] Step S2: Fit the two magnetic sleeves 22 one by one onto the thick neck of the first mold 41 and the second mold 42, so that the magnetic sleeves 22 have a portion located outside the thin neck of the corresponding mold.

[0044] Step S3: Install the outer mold jacket onto the assembly of the inner mold 4 and the magnetic sleeve 22, and perform injection molding to form an integral coil skeleton 21 and magnetic sleeve 22;

[0045] Step S4: Enamelled wire 23 and encapsulation layer 24 are provided on coil bobbin 21 to form coil assembly 2;

[0046] Step S5: Install the coil assembly 2 onto the magnetic conductor 1 and install the push rod 3.

[0047] The specific structure and docking method of the mold, as well as the specific methods in steps S2-S5, can be found in Example 1, and will not be described again here.

[0048] Since the electromagnetic drive assembly involved in the aforementioned embodiment 1 already possesses the above-mentioned technical effects, the molding process applicable to the electromagnetic drive assembly should also possess similar technical effects, so it will not be described in detail here.

[0049] The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An electromagnetic drive assembly, comprising a magnetic conductor (1), a coil assembly (2), and a push rod (3), characterized in that, The coil assembly (2) includes a coil frame (21), the coil frame (21) has a through hole (211), and magnetic sleeves (22) are provided at both ends of the coil frame (21) along the axial direction. The inner diameter of the magnetic sleeve (22) is larger than the inner diameter of the through hole (211). The surface perpendicular to the axial direction of the coil assembly (2) is defined as the projection surface. In the assembled state, the orthographic projection of the magnetic sleeve (22) on the projection surface is located outside the orthographic projection of the through hole (211) on the projection surface. The push rod (3) is installed in the through hole (211). The coil frame (21) includes a cylindrical main body and two end plates, with the two end plates located at the two ends of the cylindrical main body respectively. The through hole (211) is the inner hole of the cylindrical main body. The cylindrical main body also has an outer peripheral wall. In the assembled state, the magnetic sleeve (22) is located inside the projection of the outer peripheral wall on the projection of the projection plane.

2. The electromagnetic drive assembly according to claim 1, characterized in that, The magnetic sleeve (22) and the coil frame (21) are an integral structure.

3. The electromagnetic drive assembly according to claim 2, characterized in that, The integrated structure is formed by injection molding the coil frame (21) by pre-embedding the magnetic sleeve (22).

4. The electromagnetic drive assembly according to claim 3, characterized in that, The sleeve wall of the magnetic sleeve (22) is provided with a groove-shaped or hole-shaped material passage structure (221).

5. The electromagnetic drive assembly according to claim 1, characterized in that, Both ends of the coil frame (21) are provided with annular grooves, and both annular grooves are radially isolated from the through hole (211). The two magnetic sleeves (22) are installed in the two annular grooves in a corresponding manner.

6. The electromagnetic drive assembly according to any one of claims 1-5, characterized in that, In the assembled state, both magnetic sleeves (22) have protrusions (222) that protrude from the two axial end faces of the coil frame (21). The magnetic conductor (1) includes two magnetic walls arranged opposite to each other. Both magnetic walls are provided with through holes (111). The two protrusions (222) are fixedly connected to the two through holes (111) in a one-to-one correspondence.

7. The electromagnetic drive assembly according to claim 6, characterized in that, The outer wall of the protrusion (222) engages with the wall of the through hole (111) and is fixed by welding; and / or, The magnetic conductor (1) includes a U-shaped first magnetic conductor (11) and a plate-shaped second magnetic conductor (12), and the bottom wall of the first magnetic conductor (11) and the second magnetic conductor (12) are both provided with the through hole (111).

8. A molding process for an electromagnetic drive assembly, characterized in that, The molding process, applicable to the electromagnetic drive assembly according to any one of claims 1-7, comprises the following steps: Step S1, configure the mold; The mold includes an inner mold (4) and an outer mold. The inner mold (4) includes a first mold body (41) and a second mold body (42) joined together along the axial direction. Both the first mold body (41) and the second mold body (42) include a thick neck and a thin neck connected together. Step S2: The two magnetic sleeves (22) are fitted onto the thick necks of the first mold (41) and the second mold (42) in a corresponding manner, and the magnetic sleeves (22) have a portion located outside the thin neck of the corresponding mold, and there is a gap between the magnetic sleeves (22) and the thin neck of the corresponding mold. Step S3: Install the outer mold jacket onto the combination of the inner mold (4) and the magnetic sleeve (22) and perform injection molding to form an integral coil skeleton (21) and magnetic sleeve (22). Step S4, an enameled wire (23) and an encapsulation layer (24) are provided on the coil frame (21) to form the coil assembly (2). Step S5: Install the coil assembly (2) onto the magnetic conductor (1) and install the push rod (3).

9. The molding process of the electromagnetic drive assembly according to claim 8, characterized in that, In step S3, both magnetic sleeves (22) have protrusions (222) that protrude from both ends of the coil frame (21) along the axial direction. In step S5, the magnetic conductor (1) includes two opposing magnetic walls, each of which has a through hole (111), and the two protrusions (222) are fixedly connected to the two through holes (111) in a one-to-one correspondence.

10. The molding process of the electromagnetic drive assembly according to claim 9, characterized in that, In step S5, the connection between the protrusion (222) and the through hole (111) is specifically as follows: the outer wall of the protrusion (222) is joined to the hole wall of the through hole (111) and fixed by welding.

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