Preparation method of stator assembly and preparation mold thereof

Abstract

The invention provides a preparation method and a preparation mold of a stator assembly, and relates to the field of coil injection molding, and the preparation method of the stator assembly comprises the following steps: providing a coil assembly; primary injection molding is carried out, injection molding is carried out with the coil assembly as an insert, a pre-injection-molded part is formed after at least one injection molding step, the pre-injection-molded part comprises a pre-injection-molded part, and at least part of the winding can be fixedly connected with the framework through the pre-injection-molded part; assembling the iron core and the pre-injection molding piece; and secondary injection molding: performing injection molding by taking the assembled pre-injection-molded part and the iron core as inserts, forming an injection-molded part of the stator assembly after at least the secondary injection molding step, and at least wrapping the winding by the injection-molded part. According to the rubber coating preparation method, the fastening step of the coil copper wire and the plastic coating step of the product are combined, and the product preparation efficiency and the quality control qualification rate can be improved while the labor cost can be reduced.

Description

Technical Field

[0001] The present application relates to the field of injection molding technology, and in particular, to a method for preparing a stator assembly and a preparation mold thereof. Background Art

[0002] In the preparation of the stator assembly, the fixation of the two and the insulation of the copper wire are generally achieved by injection molding and glue pouring. In the related art, an upper limit portion and a lower limit portion are respectively provided at both ends of the skeleton body, and the upper limit portion is provided with a plurality of connecting holes, and the connecting holes are located between the inner layer and the outer layer of the skeleton. Colloid is poured into the space between the inner layer and the outer layer of the skeleton through the first connecting hole, so that the copper wire between the inner layer and the outer layer of the skeleton can be fixed.

[0003] However, in the actual overmolding process, the copper wire is still prone to position displacement due to the extrusion of the rubber after injection, causing part of the copper wire to be pushed to the edge and partially exposed. Summary of the invention

[0004] The purpose of the present application is to provide a method for preparing a stator assembly and a preparation mold thereof, which can improve the problem of partial winding exposure.

[0005] In order to solve the above problems, the present application adopts the following technical solution: The present application provides a method for preparing a stator assembly, the stator assembly comprising: a coil assembly, an iron core and an injection molding part, the coil assembly comprising a skeleton and a winding at least partially wound around the skeleton, the preparation method comprising the following steps:

[0006] providing a coil assembly;

[0007] One-time injection molding, using the coil assembly as an insert for injection molding, forming a pre-injection molded part after at least one injection molding step, wherein the pre-injection molded part includes a pre-injection molded part, and at least part of the winding can be fixedly connected to the frame through the pre-injection molded part;

[0008] Assembling the iron core and the pre-injection molded part;

[0009] Secondary injection molding, the assembled pre-injection molded part and the iron core are injection molded as an insert, and after at least the secondary injection molding step, an injection molded part of the stator assembly is formed, and the injection molded part at least covers the winding.

[0010] The present application provides a method for preparing an electromagnetic coil by encapsulation, in which the coil assembly is used as an insert for one-time injection molding, the winding and the frame are positioned by an injection mold, and then the injection molding material is injected to achieve a preliminary positioning of the relative positions of the frame and the winding, thereby avoiding the situation in which the winding is pushed by the injection molding material when the whole is directly injection molded, resulting in part of the winding not being coated.

[0011] The present application also provides a preparation mold used in a method for preparing a stator assembly, the preparation mold comprising a first mold group for primary injection molding and a second mold group for secondary injection molding, wherein the first mold group comprises a first mold body, the first mold body comprises a plurality of fixing parts protruding from an inner side wall of the mold body, the fixing parts are circumferentially spaced apart on the inner side of the mold body, a first gap is provided between adjacent fixing parts, the first mold group comprises a first injection port, the first injection port is connected to the first gap; the second mold group comprises a molding mold shell having an interior in the form of the stator assembly, a second gap is provided between the molding mold shell and a workpiece, the second mold group comprises a second injection port, the second injection port is connected to the second gap.

[0012] By setting a fixing part on the first mold body, during the first injection molding, the fixing part can abut the winding wound on the frame, and the injection plastic can flow into the gap between two adjacent fixing parts through the first injection port, thereby realizing the pre-fixation of the winding and the frame. During the second injection molding, the injection plastic flows into the gap between the abutting part and the second mold body through the second injection port, thereby realizing the coating of the coil assembly by the injection molding part. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0014] Figure 1 This is a schematic diagram of the product structure of a stator assembly according to an embodiment of the present application;

[0015] Figure 2 This is a schematic diagram of the exploded structure of a stator assembly in an inverted direction according to an embodiment of the present application;

[0016] Figure 3 This is a schematic diagram of the coil assembly and the split structure of the iron core shown in one embodiment of the present application;

[0017] Figure 4 This is a schematic diagram of the structure of a pre-injection molded part according to an embodiment of the present application;

[0018] Figure 5 This is a schematic diagram of the assembly structure of a coil assembly and a pre-injection molded part according to an embodiment of the present application;

[0019] Figure 6 This is a schematic diagram of the steps of the encapsulation preparation method shown in one embodiment of the present application;

[0020] Figure 7A schematic diagram of a mold structure for making a pre-injection molded part is shown for one embodiment of the present application.

[0021] Reference numerals:

[0022] 1-stator assembly, 2-coil assembly, 3-iron core, 4-pre-injection molded parts, 5-mold preparation;

[0023] 21-frame, 22-winding, 221-first rubber-wrapping position, 222-second rubber-wrapping position, 23-limiting portion, 231-upper limit portion, 232-lower limit portion;

[0024] 31-first glue inlet, 32-second glue inlet, 33-locking structure, 34-conductor wiring part, 341-housing, 342-wiring port, 35-through hole;

[0025] 41-pre-injection molding unit, 42-injection molding unit;

[0026] 51- mold body, 52- fixing part. Specific embodiments

[0027] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0028] It should be understood that the words "first", "second" and similar words used in the specification and claims of this application do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, words such as "one" or "one" do not indicate a quantity limitation, but indicate the existence of at least one; "several" means two or more quantities, unless otherwise specified. The directional words such as upper, lower, left, right, front, back, inside, outside, top, bottom, etc. mentioned or may be mentioned in the text are defined relative to the structure shown in the corresponding drawings. They are relative concepts, so they may change accordingly according to their different positions and different usage states. Therefore, these or other directional terms should not be interpreted as restrictive terms. "Include" or "comprise" and similar words mean that the elements or objects appearing before "include" or "comprise" include the elements or objects listed after "include" or "comprise" and their equivalents, and do not exclude other elements or objects.

[0029] The valve device of the exemplary embodiment of the present application is described in detail below in conjunction with the accompanying drawings. In the absence of conflict, the features of the following embodiments and implementations can complement or be combined with each other.

[0030] The following is combined with Figure 1 To Attachment Figure 6 Some embodiments of the header assembly are described in detail.

[0031] like Figures 1 to 6 The stator assembly 1 includes a coil assembly 2 and an iron core 3 correspondingly assembled with the coil assembly 2. The product is obtained by correspondingly sleeved the iron core 3 on the outside of the coil assembly 2 and encapsulating and injecting the product into one piece. The coil assembly 2 includes a frame 21 and a winding 22 tightly wound on the frame 21. After the iron core 3 and the coil assembly 2 are assembled, a winding space for simply accommodating the winding 22 can be formed by enclosing the iron core 3 and the frame 21, and the winding 22 can be wrapped and clamped by the iron core 3 and the inner and outer sides of the frame 21.

[0032] In one embodiment, an injection molding part 42 is further provided on the outside of the winding 22, and the winding 22 is coated and fastened by the injection molding part 42 to prevent the winding 22 from moving and shifting in the winding space and being exposed to the outside through the assembly gap, thereby causing a safety hazard. Specifically, the rubber can be filled into the glue inlet point on the winding space, and the injection molding part 42 is formed after the rubber flows and is evenly formed, so as to surround and cover the wire body of the winding 22 to meet the requirement of isolation from the outside.

[0033] Preferably, the encapsulation preparation method of the stator assembly 1 comprises the following steps:

[0034] Providing a coil assembly 2;

[0035] One-time injection molding, using the coil assembly 2 as an insert for injection molding, forming a pre-injection molded part 4 after at least one injection molding step, wherein the pre-injection molded part 4 includes a pre-injection molded part 41, and at least part of the winding can be fixedly connected to the frame 21 through the pre-injection molded part 41;

[0036] Assembling the iron core 3 and the pre-injection molded part 4;

[0037] Secondary injection molding, the assembled pre-injection molded part 4 and the iron core 3 are injection molded as an insert, and the injection molded part 42 of the stator assembly is formed after at least the secondary injection molding step, and the injection molded part 42 at least covers the winding 22.

[0038] Preferably, the injection molding portion 42 is wrapped around the periphery of the winding 22, and can be divided into a first wrapping position 221 and a second wrapping position 222 according to the wrapping area, which respectively correspond to the injection molding area of ​​the winding 22 during the first injection molding and the injection molding area during the second injection molding.

[0039] In one embodiment, the first glue encapsulation position 221 and the second glue encapsulation position 222 are arranged at intervals along the winding direction of the winding 22, and the first module clamps the coil assembly 2 from the outer part to position it to complete a one-time injection molding. Among them, the fixing part 52 on the first module is arranged one-to-one with the second glue encapsulation position 222. In the one-time injection molding, the skeleton 21 wrapped with the winding 22 is used as an insert and placed in the first module, so that the fixing part 52 and the second glue encapsulation position 222 are directly clamped against each other, and a gap space is left between the first glue encapsulation position 221 and the first module. By filling the outer periphery of the first glue encapsulation position 221 with glue and cooling it to form, the initial coil in which the winding 22 and the skeleton 21 are relatively fastened is obtained.

[0040] Since the first rubber-wrapped position 221 and the second rubber-wrapped position 222 on the winding 22 are arranged at intervals, the fixing part 52 is respectively abutted and clamped with the copper wire on the second rubber-wrapped position 222, so that the entire coil can be wound evenly in the circumferential direction, and the running margin of the copper wire is evenly distributed to each first rubber-wrapped position 221. When the rubber-wrapped injection is performed, the copper wire of the first rubber-wrapped position 221 can be pushed back and evenly placed again by the pressure of the injection. After these two squeezes, it is basically ensured that the copper wire on the winding frame is in a tight state, and the injection molding is completed at this time to achieve the best state that the entire coil assembly structure is integrated and the copper wire position is uniform and fixed after the first rubber-wrapped injection is completed.

[0041] Specifically, the fixing portion 52 on the first module abuts against the winding 22 on the second encapsulation position 222 during the encapsulation process. Before filling the rubber material to start the injection molding process, the winding 22 is first pushed by the fixing portion 52 to arrange it evenly, ensuring that the winding 22 is tightly wound before starting to fill the rubber material for injection molding.

[0042] Furthermore, when filling with rubber for injection molding, the rubber will be compressed after flowing into the first rubber encapsulation position 221 to generate a certain injection molding pressure, and the winding 22 at the first rubber encapsulation position 221 will be pushed twice, so that the winding 22 can be evenly arranged at each location on the circumference of the skeleton 21, ensuring that the relative position of the copper wire is fixed. It is necessary to spend manpower and time costs separately to invest in the process steps of tightening the winding 22 to improve the efficiency of automated production.

[0043] It is easy to imagine that the first module can include a mold body 51 and a fixing portion 52 arranged on the mold body 51. The mold body 51 and the fixing portion 52 can be an integrally formed component, or an assembled component radially penetrated in the mold body 51 and capable of telescopic relative movement.

[0044] Preferably, the fixing part 52 is integrally formed with the mold body 51, and the mold body 51 of the first mold group may also be composed of multiple parts. For example, there are four mold bodies 51, which are respectively located in the front, back, left and right directions of the coil assembly 2. The fixing part 52 is located on the inner side walls opposite to the four mold bodies 51. The first mold group also includes a driving structure, which synchronously drives the mold body 51 to shrink toward the center, and the fixing part 52 is attached to the winding 22 of the second encapsulation position 222 to clamp the entire coil assembly 2. However, it is not limited to this, and it may also be composed of two mold bodies 51 arranged on the left and right sides, or it may also be composed of three mold bodies 51 coaxially arranged around the center.

[0045] In one embodiment, the fixing portion 52 of the first module is protruding relative to the inner wall of the mold body 51. After the insert is clamped and fixed by the fixing portion 52, a first gap is formed between the mold body 51 and the insert. A first injection port is provided between adjacent fixing portions 52. The first gap area between adjacent fixing portions 52 is filled with injection plastic through the first injection port. After the injection plastic is solidified, a pre-injection molded portion 41 is formed. The winding 22 and the frame 21 are fixedly connected through the pre-injection molded portion 41 to form a complete pre-injection molded part 4.

[0046] It can also be understood that the first rubber encapsulation position 221 and the second rubber encapsulation position 222 can be evenly distributed in the circumferential direction of the winding, and the number of rubber encapsulation positions and the single width can be reasonably allocated according to the size of different workpieces. Preferably, the single rubber encapsulation width of the first rubber encapsulation position 221 in the circumferential direction is about 39 mm, and there are 7 intervals between the first rubber encapsulation position 221 and the second rubber encapsulation position 222, which together surround the circumference of the entire coil assembly 2.

[0047] In addition, the frame 21 further includes a limiting portion 23 disposed on the side of the winding area. The limiting portion 23 protrudes relatively from the winding area in a circumferential direction to form a step that blocks the winding 22 .

[0048] A plurality of first connection parts are evenly arranged circumferentially on the limiting part 23, and a second connection part assembled corresponding to the first connection part is provided on the iron core 3. It can be understood that the first connection part may include but is not limited to a through hole, a screw hole, a groove, and an opening, and the second connection part may include but is not limited to a connecting column and a screw.

[0049] In one embodiment, the step of assembling the iron core 3 and the pre-injection molded part 4 includes connecting the iron core 3 and the pre-injection molded part 4 through a first connecting part and a second connecting part. The two can be installed in the axial direction during assembly, and circumferentially limited by the first connecting part and the second connecting part, and then processed into an integral shape through a secondary injection molding step.

[0050] Furthermore, the bottom of the winding area of ​​the frame 21 is also provided with wire grooves evenly arranged along the winding direction, so as to facilitate the correction of the direction of the winding 22 during winding.

[0051] In one embodiment, the limit portion 23 includes an upper limit portion 231 and a lower limit portion 232 located on both sides of the winding area. The upper limit portion 231 and the lower limit portion 232 both protrude from the winding plane and form a circular runway therebetween so that the winding 22 can be wound in the runway to avoid displacement or falling off.

[0052] It can be understood that the limiting portion 23 is also provided with a first glue inlet 31 that is connected through and through. When the skeleton 21 after the winding 22 is placed into the first module as an insert, the first glue inlet 31 is arranged one-to-one with the first glue encapsulation position 221, and the glue is filled into the injection molding through an externally connected injection pipeline.

[0053] During an operation, the first glue inlet 31 is arranged on the lower limit portion 232. When an injection molding process is performed, the coil assembly 2 can be inverted in the first module, and the glue can be filled from the first glue inlet 31 on the lower limit portion 232 from top to bottom. The gravity of the glue itself and the pressure of the punching material are used to accelerate the penetration of the glue, thereby improving the penetration efficiency and uniformity of the first encapsulation process.

[0054] Furthermore, before the secondary injection molding process, the coil assembly 2 and the iron core 3 after the initial overmolding need to be assembled, and the assembled whole is placed in the second module as a new insert for secondary overmolding.

[0055] In one embodiment, a locking structure 33 is further provided between the frame 21 and the iron core 3, and the locking structure 33 includes a mounting hole provided on the position limiting portion 23 and a locking pin penetrating the iron core 3, and the locking pin penetrates the mounting hole to fasten the two. In addition, the locking structure 33 can also be other fastening assembly connection methods, such as: rotating screws, pins, welding, etc.

[0056] Preferably, the assembly component of the locking structure 33 is arranged on the upper limit portion 231 of the limit portion 23, and the iron core 3 is sleeved and aligned above the initial coil assembly 2 so that the locking pin and the mounting hole are centrally locked and assembled.

[0057] It is understandable that the locking structure 33 can be directly fixed and assembled by the first connection part on the limit part 23 and the second connection part on the iron core 3, or can be fixedly connected by other separate locking structures. After the iron core 3 and the pre-injection molded part 4 are fixedly connected by the locking structure 33, they are processed into one piece through a secondary injection molding step.

[0058] The limiting portion 23 is arranged on the side of the winding direction, which can further block the copper wire wound on the winding frame 21 to prevent the copper wire from detaching from the winding frame 21 before the completion of the first injection molding positioning. At the same time, the first connecting portion on the limiting portion 23 can also be used as a guiding structure when assembling the iron core 3 and the coil assembly 2. The limiting portion 23 guides the two to be assembled, and then the locking structure 33 is used to lock them together to ensure the relative position relationship between the two, so that the rubber material in the second overmolding process can be evenly formed.

[0059] In addition, the second module group is a product shaping mold, including a molding mold shell, through which the insert can be placed into the mold and directly injection molded into a fixed product shape.

[0060] Preferably, after the second module is assembled with the new insert, a second gap exists between the molding mold shell and the insert, and the second gap includes a gap between the outer wall of the core 3 and the second mold body in the circumferential direction, and a certain gap between the inner wall of the core 3 and the pre-injection molded part 4 at the abutment position of the original fixing portion 52. A second glue inlet 32 ​​is correspondingly provided on the stator assembly, which is opposite to the gap on the side wall of the core 3. The glue flowing in through the second glue inlet 32 ​​can wrap the outside of the core 3, and penetrate from the outside to the inside to the periphery of the winding 22 for a second plastic coating, and the stator assembly 1 is obtained after uniform molding.

[0061] It can be understood that the gap between the inner wall and the outer wall of the iron core 3 can be interconnected, and the iron core 3 and the pre-injection molded part 4 are assembled and limited on one side through the limiting portion 23, and the corresponding gap on the opposite side of the limiting portion 23 is matched with the second mold, and then the inner and outer sides of the iron core 3 are connected through the gap, so that the overall internal and external structure of the stator assembly 1 can be molded as a whole after the secondary injection molding is completed.

[0062] In another embodiment, a plurality of transverse through holes 35 are provided on the side of the core 3. It can be understood that the through holes 35 are respectively arranged opposite to the second encapsulation position 222. During the second encapsulation process, the rubber in the second module can continue to penetrate inward to the second encapsulation position 222 when flowing through the through holes 35, thereby achieving encapsulation protection for the remaining area of ​​the initial coil assembly 2, ensuring that the winding 22 can be isolated from the outside in the entire circumferential direction, and ensuring the reliability of the internal and external insulation of the product.

[0063] At the same time, since the hot rubber at the second encapsulation position 222 can further contact the rubber that has been injection-molded at the first encapsulation position 221, they can further blend with each other, and the process rubber for the first encapsulation can be injected again, so that the rubber of the entire winding 22 in the circumferential direction can blend with each other, thereby improving the consistency of the overall encapsulation process of the stator assembly 1.

[0064] Based on the first overmolding injection molding process, the internal winding 22 has been compressed and injection molded, and the relative position of the winding 22 is in a uniformly tightened state. Therefore, during the product molding process of the second overmolding process, the interference of the injection process on the position of the winding 22 can be avoided to a large extent, which can greatly improve the qualified rate of the finished product.

[0065] In addition, secondary injection molding can also cover the assembly position of the locking structure 33 with rubber, further strengthening the assembly strength between the coil assembly 2 and the iron core 3. At the same time, the assembly position can also be covered to improve the overall appearance and comfort of the product, avoiding problems such as dust accumulation, oxidation and rust due to long-term exposure of the installation hole.

[0066] Furthermore, the coil assembly 2 is further provided with a conductor connection portion 34 at the winding end of the winding 22, and the iron core 3 is further provided with a shell 341 covering the outside of the conductor connection portion 34. Specifically, the shell 341 is further provided with a connection port 342 which is sleeved on the conductor connection portion 34.

[0067] In another embodiment, during the secondary injection molding process, the encapsulation process on the second module can use a sequential valve needle hot runner to cold runner latent multi-point feeding, and the hot runner valve is adjusted to control each second injection port to feed in sequence to complete the injection molding. For example, there are 5 second injection ports distributed in the circumference of the second module, which are respectively set at position 1, position 2, position 3, position 4, and position 5 in the same direction. During the injection process, the second injection ports at positions 1-5 are controlled in sequence to control the injection in order, so as to form a product workpiece that meets the requirements of consistent penetration direction and uniform surface texture.

[0068] In the second overmolding process, sequential valve needle multi-feeding point feeding is adopted. On the one hand, it can share the injection pressure on the circumference of the electromagnetic coil, and on the other hand, it can also avoid air entrapment caused by opposite feeding between adjacent feeding points, which affects the overall injection efficiency of the product and the uniformity of the density of the molding rubber.

[0069] Preferably, the multiple second injection ports on the second module are distributed on the circumference of the core 3 starting from the conductor connection portion 34, and only one second injection port is provided on the corresponding area of ​​the shell. Since the outer shape of the shell 341 corresponding to the conductor connection portion 34 is different from other circumferential positions, there is uneven pressure on the flow of the rubber at this position, and by providing only one second injection port on the shell, when the injection begins, the rubber can start to seep from the injection point to both sides, and flow in two directions under the action of the injection pressure to completely cover the shell. If multiple injection points are provided at this position, there will inevitably be a problem of opposite seepage between two adjacent injection points, and due to the problem of uneven pressure, there will often be a phenomenon of trapped air at the meeting point, which greatly affects the integrity of the rubber package, and is prone to problems such as bubbles that affect the injection quality.

[0070] It should be noted that the first glue inlet 31 and the second glue inlet 32 ​​are glue guiding channels arranged on the frame 21 and the iron core 3 respectively, and the first glue injection port and the second glue injection port are the discharge connection ports for leading out the injection plastic on the first module and the second module respectively.

[0071] In the one-shot injection molding process, the molding step of the injection molding portion 42 further includes: the minimum distance between the conductor connection portion 34 and the edge of the injection molding portion 42 is d, wherein 3 mm≤d≤5 mm.

[0072] The winding frame 21 is provided with a conductor connection part 34 at the end of the copper wire winding, and the conductor connection part 34 is arranged close to the pre-injection part 41 of the coil assembly 2 to ensure that the starting end of the copper wire is securely fastened. It can be understood that if d is too small, the rubber material in the first overmolding process will interfere with the conductor connection part 41, and there is a risk of extrusion and deformation thereof; and if d is too large, the copper wire end will be positioned loosely, affecting the fastening state of the entire copper wire.

[0073] In an operation process, the starting section of the winding 22 is first connected to the conductor connection part 34, and then the winding 22 is tightened and wound on the frame 21, and the frame 21 with the winding 22 is placed in the first mold. At this time, the first glue inlet 31 is arranged opposite to the winding 22 on the first glue encapsulation position 221, and the injection mechanism is controlled to inject glue into the first glue encapsulation position 221 along the first glue inlet 31, and the injection molding part 42 is formed after cooling and molding. Specifically, the minimum transverse width of the edge side of the injection molding part 42 from the conductor connection part 34 is d, where the width of d is 4mm, so as to simultaneously meet the requirements of tightening the starting section of the winding 22 and reserving enough space for the glue encapsulation area of ​​the first glue encapsulation position 221, so as to avoid external force extrusion and deformation of the conductor connection part 34.

[0074] Preferably, the first encapsulation position 221 and the second encapsulation position 222 may be spaced apart by a dividing line which may be vertically separated along the cross section of the winding area of ​​the winding 22 to form a square arc-shaped injection molding portion 42; or may be an arc-shaped injection molding portion 42 formed by oblique separation to form a parallelogram, or may be an arc-shaped injection molding portion 42 with wavy edges on both sides formed by separation along a wavy line.

[0075] It can be understood that the second encapsulation position 222 refers to the part that has not been encapsulated in the one-time injection molding process, but it is not limited to this. The second encapsulation position 222 can be composed of multiple parts, or it can be a third encapsulation position that has not been encapsulated in the one-time injection molding process in addition to the second encapsulation position 222. For example, the encapsulation preparation method of the present application also includes a third encapsulation injection molding process, which is used to encapsulate the remaining parts except the first encapsulation position 221 and the second encapsulation position 222.

[0076] By tightening the winding 22 through the initial encapsulation during the one-shot molding process, the problem of the winding 22 running out of position under the existing encapsulation process is solved, and a new fully automated stator assembly 1 encapsulation assembly process is realized, which not only saves a lot of labor costs, but also significantly improves the processing efficiency of the encapsulation insulation treatment of the winding 22 product. Furthermore, on this basis, the secondary injection molding process integrates the process of the primary injection molding process, which can take into account the effect of the primary injection molding process. Therefore, for the secondary injection molding process itself, since there is no need to consider the problem of the winding 22 running out of position, the process requirements during encapsulation can be reduced to a certain extent; and for the product itself, the overall insulation exposure problem of the winding 22 is also better solved, which can not only improve the product's qualification rate advantage and reduce the energy required for manual screening, but also significantly improve the reliability of future products in future use.

[0077] In addition, the stator assembly preparation mold provided in the present application includes but is not limited to the first module and the second module, and can be adjusted according to the structural adaptability of the stator assembly, and a third module can be added to separately injection mold some structural features.

[0078] It should be noted that the above embodiments are only used to illustrate the present invention and are not intended to limit the technical solutions described in the present invention. Although the present invention has been described in detail in this specification with reference to the above embodiments, it should be understood by those skilled in the art that the present invention can still be modified or replaced by equivalents, and all technical solutions and improvements thereof that do not depart from the spirit and scope of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A method for preparing a stator assembly, characterized in that: The stator assembly comprises: a coil assembly, an iron core and an injection molding part, the coil assembly comprises a frame and a winding at least partially wound around the frame, and the preparation method comprises the following steps: providing a coil assembly; One-time injection molding, using the coil assembly as an insert for injection molding, forming a pre-injection molded part after at least one injection molding step, wherein the pre-injection molded part includes a pre-injection molded part, and at least part of the winding can be fixedly connected to the frame through the pre-injection molded part; Assembling the iron core and the pre-injection molded part; Secondary injection molding, the assembled pre-injection molded part and the iron core are injection molded as an insert, and after at least the secondary injection molding step, an injection molded part of the stator assembly is formed, and the injection molded part at least covers the winding.

2. The preparation method according to claim 1, characterized in that: The winding includes a first encapsulation position and a second encapsulation position which are circumferentially spaced apart. The one-time injection molding step includes fixing the winding at least through the second encapsulation position, the injection molding material at least covers the first encapsulation position, and the winding and the frame are fixedly connected after the injection molding material is solidified.

3. The preparation method according to claim 1 or 2, characterized in that: The secondary injection molding step includes at least clamping the assembled iron core and the pre-injection molded part through the inner side wall of the frame, the injection molding material at least covers the winding, and the injection molding part of the stator assembly is formed after the injection molding material is solidified.

4. The preparation method according to any one of claims 1 to 3, characterized in that: The skeleton includes a limiting portion arranged in the circumferential direction and a first connecting portion located on the limiting portion, and the iron core is provided with a second connecting portion corresponding to the first connecting portion. The step of assembling the iron core and the pre-injection molded part includes connecting the iron core and the pre-injection molded part through the first connecting portion and the second connecting portion.

5. The preparation method according to claim 4, characterized in that: The first connecting portion and the second connecting portion are assembled in position to form a locking structure, and the secondary injection molding step includes the injection molding covering at least the end surface of the locking structure, and the iron core is fixedly connected to the pre-injection molded part after the injection molding is solidified.

6. The preparation method according to claim 2, characterized in that: The coil assembly also includes a plurality of first glue inlets arranged on the frame, wherein the positions of the first glue inlets are arranged relative to the first glue encapsulation position, and the one-time injection molding step includes injecting plastic into at least through the first glue inlet to fill the space at the first glue encapsulation position, and after the injection plastic is solidified, the winding and the frame are fixedly connected.

7. The preparation method according to claim 2, characterized in that: The iron core is also provided with a plurality of through holes in the circumferential direction, and the positions of the through holes are arranged relative to the second encapsulation position. The secondary injection molding step includes the injection plastic entering at least through the through holes to fill the space at the second encapsulation position, and the pre-injection molded part and the iron core are fixedly connected after the injection plastic is solidified.

8. The preparation method according to claim 2, characterized in that: The skeleton also includes a conductor connection portion connected to the winding end of the winding, and the minimum distance between the conductor connection portion and the adjacent first encapsulation position is d, wherein 3mm≤d≤5mm; the one-time injection molding step includes setting the first encapsulation position as a starting point from a position at a distance d from the conductor connection portion.

9. The preparation method according to claim 1, characterized in that: The stator assembly includes a shell that at least partially covers the outside of the iron core, and the shell is provided with a connected wiring port corresponding to the end position of the winding. The secondary injection molding step includes injecting injection plastic from the position of the wiring port from near to far, and the shell is formed after the injection plastic is solidified.

10. A mold for preparing a stator assembly, characterized in that: The preparation mold includes a first mold set for primary injection molding and a second mold set for secondary injection molding, wherein: The first mold group includes a first mold body, the first mold body includes a plurality of fixing parts protruding from the inner side wall of the mold body, the fixing parts are circumferentially arranged inside the mold body, and there is a first gap between adjacent fixing parts, the first mold group includes a first glue injection port, and the first glue injection port is connected to the first gap; The second die set includes a molding die shell with the stator assembly in the form of the interior, a second gap is defined between the molding die shell and the workpiece, and the second die set includes a second glue injection port, and the second glue injection port is connected to the second gap.

11. The preparation mold according to claim 10, characterized in that: A plurality of the second glue injection ports are arranged along the circumference of the second module. The second module further comprises a sequence valve. The valve cavity of the sequence valve can be connected to the second glue injection port.

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