A high-efficiency injection molding method for the inner stator and rotor cores of an electric motor

Abstract

This invention relates to the field of injection molding technology, and more particularly to a high-efficiency overmolding injection molding method for the iron cores of motor stators and rotors, comprising the following steps: A. Iron core pre-classification; B. Mold structure preparation; C. Gasket matching and installation; D. Iron core loading; E. Injection molding. This invention, through iron core pre-classification, preparation of adjustable gasket combinations in mold inserts, and precise matching and installation of gaskets, enables the mold cavity dimensions to dynamically, efficiently, and accurately adapt to iron core stacks with different thickness deviations. This reduces the procurement cost of iron core coils. Simultaneously, by adjusting the gasket combination instead of manufacturing inserts of various heights, it effectively reduces the processing cost and management complexity of mold components. It completely eliminates common defects in overmolded products such as burrs, appearance defects, and dimensional inconsistencies, ensuring product quality, improving production efficiency and material utilization, thereby solving the problem of high production costs in traditional processes.

Description

Technical Field

[0001] This invention relates to the field of injection molding technology, and in particular to a high-efficiency injection molding method for overmolding the iron core of an electric motor stator and rotor. Background Technology

[0002] In the injection molding production of stator and rotor cores for electric motors, the total thickness of the core laminations often exhibits unavoidable deviations. This is mainly due to the cumulative effect of individual lamination thickness tolerances and stacking tolerances, resulting in the total height of each batch of stamped core laminations potentially fluctuating between 0.05mm and 0.25mm. Traditional injection molds typically use cavities of fixed dimensions, which exposes significant problems when dealing with core lamination thickness deviations.

[0003] Specifically, when the core laminations are too thin, the gap between the core laminations and the top surface of the mold cavity will increase, leading to defects such as excessive glue or excessive glue thickness in the injection molded product. Conversely, when the core laminations are too thick, the cavity space becomes smaller, which can easily lead to incomplete filling, insufficient glue thickness, or even deformation of the core laminations themselves due to excessive extrusion, resulting in product scrap.

[0004] To address these issues, existing technologies typically employ two costly solutions: one is to strictly tighten the tolerances for individual iron core laminations, which significantly increases the procurement cost of the iron core lamination coils; the other is to manufacture back die inserts of various heights to accommodate iron core laminations of different thicknesses, but this also significantly increases the processing cost and management complexity of the die inserts. Neither of these methods meets the demands of modern industry for low-cost, rapid, efficient, and high-precision production.

[0005] Therefore, there is a need for an injection molding method that can efficiently and accurately adapt to the total thickness deviation of the iron core laminations and effectively solve the product defects and high production costs caused by it. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of existing technologies by providing a highly efficient injection molding method for the stator and rotor cores of motors. Through core pre-classification, preparation of adjustable shim combinations in the mold inserts, and precise matching and installation of the shims, the mold cavity dimensions can dynamically, efficiently, and accurately adapt to core stacks with varying thickness deviations. This reduces the procurement cost of core coils. Simultaneously, by adjusting the shim combinations instead of manufacturing inserts of multiple heights, the processing cost and management complexity of mold components are effectively reduced. This completely eliminates common defects in injection-molded products such as burrs, appearance defects, and dimensional inconsistencies, ensuring product quality, improving production efficiency and material utilization, thereby solving the problem of high production costs in traditional processes.

[0007] To achieve the above objectives, the present invention provides a high-efficiency injection molding method for overmolding the stator and rotor cores of an electric motor, comprising the following steps:

[0008] A. Core pre-classification: Core lamination sets are classified into different thickness deviation levels according to the thickness of the core laminations;

[0009] B. Mold structure preparation: The overmolding injection mold includes an insert structure, which is set in the rear mold or the front mold of the mold. The insert structure is provided with multiple shims of different thicknesses that can adjust the mold cavity size. The multiple shims are stacked to form multiple pre-selected shim combinations. The shim combinations are used to match the core laminations with different thickness deviation levels.

[0010] C. Shim matching and installation: Based on the core lamination set with different thickness deviation levels, select and install the pre-selected shims that match it in the insert structure to adjust the mold cavity size;

[0011] D. Core loading: Positioning the stacked iron core laminations and loading them into the mold cavity;

[0012] E. Injection molding: The mold is closed and the iron core laminations are injection molded.

[0013] Preferably, the insert structure includes a first insert and a second insert.

[0014] The first insert has a cavity inside for accommodating the iron core laminations to be coated and injection molded;

[0015] The first insert is embedded inside the second insert;

[0016] A fixing member is provided inside the cavity. The upper end of the fixing member abuts against the front mold, and the lower end of the fixing member abuts against the rear mold. The iron core laminations are fixed between the fixing member and the first insert.

[0017] Preferably, the front mold is provided with a front inner mold, and the front inner mold is disposed inside the front mold;

[0018] The rear mold is provided with a rear inner mold and a push plate. The rear inner mold is disposed inside the rear mold, and the push plate is disposed at one end of the rear inner mold near the front inner mold.

[0019] A sliding block is provided between the front mold and the rear mold. The upper part of the sliding block abuts against the front inner mold, and the lower part of the sliding block abuts against the push plate.

[0020] The front mold, front inner mold, rear mold, rear inner mold, push plate, and sliding block are combined to form the mold cavity.

[0021] Preferably, one end face of the sliding block abuts against the outer surface of the first insert;

[0022] The inner side of the rear inner mold and the inner side of the push plate both abut against the outer side of the second insert.

[0023] Preferably, the fastener includes a first fixing block and a second fixing block, and the first fixing block and the second fixing block are fixed by bolts;

[0024] The upper end of the first fixing block abuts against the front mold, and the lower end of the second fixing block abuts against the rear mold.

[0025] Preferably, the multiple gaskets of different thicknesses include a first gasket, a second gasket, a third gasket, and a slider gasket;

[0026] The first gasket, the third gasket, and the slider gasket are all provided with thin sheet type and thick sheet type, the thickness of the thick sheet type is greater than the thickness of the thin sheet type, and the thickness of the second gasket is fixed.

[0027] The first gasket of different thicknesses, the third gasket, and the slider gasket are combined with the second gasket to form a plurality of pre-selected gasket combinations.

[0028] Preferably, the specific method for installing the gasket is as follows:

[0029] The first gasket and the second gasket are disposed at the bottom of the second insert;

[0030] The third gasket is disposed at the bottom of the first insert and abuts against the bottom of the second gasket and the bottom of the iron core lamination, respectively;

[0031] The slider pad is disposed on the side of the slider block near the front inner mold.

[0032] Preferably, the specific method for gasket matching is as follows:

[0033] a. Based on the actual total thickness T of the iron core laminations 实际 The ideal total core thickness T set by the mold 理想 Thickness deviation ΔT=T 实际 -T 理想 Determine the amount of movement ΔZ required to adjust the top surface of the first insert. 镶件 , where ΔZ 镶件 =T 理想 -T 实际 ;

[0034] b. When the thickness deviation of the core laminations ΔT < 0, T 实际 <T 理想 This leads to ΔZ 镶件 If the value is greater than 0, the first insert needs to be moved downwards. From the pre-selected shim combinations, a thick first shim, a thin third shim, and a thin slider shim are chosen, ensuring that the total thickness change of the pre-selected shim combination is equal to the required adjustment amount ΔZ of the top surface of the first insert. 镶件 This matches, thereby achieving a corresponding reduction in the top surface of the first insert;

[0035] c. When the thickness deviation of the core laminations ΔT > 0, T 实际 >T 理想 This leads to ΔZ 镶件 If the thickness is less than 0, the first insert needs to be moved upwards. From the pre-selected shim combinations, select a thin first shim, a thick third shim, and a thick slider shim, such that the total thickness change of the pre-selected shim combinations is equal to the required adjustment amount ΔZ of the top surface of the first insert. 镶件 This matches, thus achieving a corresponding increase in the top surface of the first insert.

[0036] Preferably, the core pre-classification step includes: sorting the core laminations of different thickness deviation levels from the largest to the smallest quantity, and selecting them in sequence as priority batches for overmolding injection molding for processing.

[0037] Preferably, the thickness of the iron core laminations is measured after compaction, and the compaction pressure of the iron core laminations is equal to the holding pressure of the overmolding injection mold.

[0038] The beneficial effects of this invention are as follows: By pre-classifying the iron core, preparing adjustable shim combinations in the mold inserts, and precisely matching and installing the shims, the mold cavity dimensions can dynamically, efficiently, and accurately adapt to iron core stacks with different thickness deviations. This reduces the procurement cost of iron core coils. Simultaneously, by adjusting the shim combinations instead of manufacturing inserts of various heights, the processing cost and management complexity of mold components are effectively reduced. It completely eliminates common defects in overmolded injection molded products, such as burrs, appearance defects, and dimensional inconsistencies, ensuring product quality, improving production efficiency and material utilization, thereby solving the problem of high production costs in traditional processes. Attached Figure Description

[0039] Figure 1 This is a flowchart illustrating the steps of the overmolding injection molding method of the present invention.

[0040] Figure 2 This is a cross-sectional view of the overmolding injection mold of the present invention.

[0041] Figure 3 This is a cross-sectional view of the insert structure of the present invention.

[0042] Figure 4 This is a schematic diagram of the insert structure and the rear mold cross-section of the present invention.

[0043] The reference numerals in the figures include:

[0044] 1. Iron core laminations; 2. Insert structure; 21. First insert; 22. Second insert; 221. Limiting edge; 222. Inclined surface; 23. Fixing component; 231. First fixing block; 232. Second fixing block; 233. Limiting slot; 3. Rear mold; 31. Rear inner mold; 311. Limiting groove; 32. Push plate; 321. Inclined surface; 4. Front mold; 41. Front inner mold; 5. Sliding block; 6. First gasket; 7. Second gasket; 8. Third gasket; 9. Sliding block gasket. Detailed Implementation

[0045] The present invention will now be described in detail with reference to the accompanying drawings.

[0046] like Figures 1 to 4 As shown, the present invention provides a high-efficiency injection molding method for overmolding the iron cores of the stator and rotor of an electric motor, comprising the following steps:

[0047] A. Core pre-classification: Classify core laminations into sets with different thickness deviation levels according to the thickness of core lamination 1; realize the classification of core laminations 1 in production according to thickness deviation.

[0048] B. Mold Structure Preparation: The overmolding injection mold includes an insert structure 2, which is located in the rear mold 3 or the front mold 4. The insert structure 2 is equipped with multiple shims of different thicknesses to adjust the mold cavity size. These shims are stacked to form multiple pre-selected shim combinations, which are used to match the iron core stacks with different thickness deviation levels. This achieves the goal of setting an adjustable structure in the mold insert, formed by stacking multiple shims of different thicknesses. By adjusting the mold cavity size through the shim combinations, the mold can adapt to iron core stacks 1 of different thicknesses. This eliminates the need to strictly tighten the tolerance of individual iron cores, reducing the procurement cost of iron core coils.

[0049] C. Shim Matching and Installation: Based on the core lamination sets with different thickness deviation levels, select and install pre-selected shim combinations that match them in the insert structure 2 to adjust the mold cavity dimensions. This allows for the selection and installation of corresponding shim combinations based on the thickness deviation of the core lamination 1 to precisely adjust the height or depth of the mold cavity. Only the shim combinations need to be adjusted to accommodate the thickness deviation of the core lamination 1, eliminating the need to manufacture inserts of various heights to fit different thicknesses of the core lamination 1, thus reducing the processing cost and management complexity of mold components. Simultaneously, it enables the mold to efficiently and accurately adapt to the total thickness deviation of the core lamination 1.

[0050] D. Core loading: Position the core stack 1 and load it into the mold cavity; ensure that the core stack 1 is accurately positioned and supported in the mold, thereby avoiding defects caused by uneven core thickness during injection molding.

[0051] E. Injection Molding: The mold is closed and the iron core stack 1 is injection molded. This produces a rubber-coated injection molded iron core without burrs (explosive material or rough edges appearing on the product edges or parting lines), and with acceptable appearance and dimensions. This solves the product defects and high production costs caused by uneven iron core thickness in traditional processes, achieving efficient production and high-quality output.

[0052] During the process, firstly, before the injection molding operation, the core laminations 1 are pre-classified. Based on the thickness deviation of the core laminations 1, they are divided into core lamination sets of different thickness deviation levels, laying the foundation for subsequent precise processing.

[0053] Secondly, the overmolding injection mold features a pre-designed adjustable mold cavity. The key to this mold lies in its insert structure 2, which cleverly incorporates multiple shims of varying thicknesses to adjust the mold cavity size. These shims can be stacked and combined to form several pre-selected shim combinations, each designed to precisely match a specific thickness tolerance level of the core stack. This gives the overmolding injection mold the ability to flexibly adjust to actual conditions during production.

[0054] Next, the shims are matched and installed. Based on the thickness deviation of the current core lamination set, pre-selected shim combinations that match it are selected and installed in the insert structure 2. The core of this step is to adjust the mold cavity size to ensure that the mold cavity matches the actual thickness of the current core lamination 1, eliminating gaps or compression problems caused by uneven thickness.

[0055] After adjusting the mold cavity dimensions, the iron core lamination 1 was precisely positioned and installed into the mold cavity. Subsequently, the overmolding injection mold was closed and injection molding was performed. Because the mold cavity dimensions had been optimized for the thickness of the iron core lamination 1, the injection molding process proceeded smoothly and efficiently.

[0056] Ultimately, this method ensured that the produced injection-molded iron cores were free of burrs and met the requirements for appearance and dimensions. This not only solved common quality problems in traditional processes but also significantly improved production efficiency and material utilization.

[0057] like Figures 2 to 3 As shown, the insert structure 2 in this embodiment includes a first insert 21 and a second insert 22.

[0058] The first insert 21 has a cavity inside that accommodates the iron core lamination 1 to be coated and injected;

[0059] The first insert 21 is embedded inside the second insert 22. This precisely fitted insert structure 2 provides structural assurance for the stability and adjustability of the mold cavity, and is the basis for achieving subsequent precise injection molding.

[0060] A fixing member 23 is provided inside the cavity. The upper end of the fixing member 23 abuts against the front mold 4, and the lower end of the fixing member 23 abuts against the rear mold 3. The iron core stack 1 is fixed between the fixing member 23 and the first insert 21. This ensures that the iron core stack 1 can be firmly fixed between the fixing member 23 and the first insert 21. This ensures the precise and stable position of the iron core stack 1 during the injection molding process, avoiding defects such as incomplete injection and burrs caused by iron core displacement or shaking in traditional processes, thereby improving the finished product quality of the overmolded iron core.

[0061] like Figure 2 As shown, in this embodiment, the front mold 4 is provided with a front inner mold 41, which is located inside the front mold 4.

[0062] The rear mold 3 is provided with a rear inner mold 31 and a push plate 32. The rear inner mold 31 is located at the rear inner mold 31, and the push plate 32 is located at the end of the rear inner mold 31 near the front inner mold 41.

[0063] A sliding block 5 is provided between the front mold 4 and the rear mold 3. The upper part of the sliding block 5 abuts against the front inner mold 41, and the lower part of the sliding block 5 abuts against the push plate 32. The ingenious design of the sliding block 5 and the push plate 32 enhances the overall rigidity and sealing of the mold cavity, effectively preventing problems such as overflow (burrs) or dimensional instability during the injection molding process, thereby ensuring that the overmolded injection molded iron core is free of burrs and has qualified appearance and dimensions.

[0064] The front mold 4, front inner mold 41, rear mold 3, rear inner mold 31, ejector plate 32, and sliding block 5 enclose and form the mold cavity. This means the mold cavity is not simply formed by two mold pieces directly joined together, but rather by multiple components working together. This ensures high stability and precision of the mold cavity during the injection molding process. It provides a solid and seamless mold cavity for the precise overmolding of the iron core laminations 1, forming the foundation for high-quality injection molding.

[0065] like Figure 2 As shown, one side of the sliding block 5 in this embodiment abuts against the outer side of the first insert 21; this ensures the lateral positional stability of the first insert 21 in the mold cavity, avoids possible lateral displacement or shaking of the first insert 21 during injection molding, thereby ensuring the lateral dimensional accuracy of the mold cavity and effectively preventing the problem of burrs or inaccurate dimensions on the side of the product.

[0066] The inner sides of the rear inner mold 31 and the push plate 32 both abut against the outer side of the second insert 22. This provides the second insert 22 with dual support and enclosure from the rear inner mold 31 and the push plate 32 within the mold. This multi-point abutment structure enhances the overall rigidity and stability of the second insert 22 within the mold. It ensures the overall structural integrity and dimensional accuracy of the mold cavity, and especially under injection pressure, it effectively resists deformation, further guaranteeing that the overmolded injection core is free of burrs and meets appearance and dimensional standards.

[0067] like Figure 4 As shown, in actual use, the second insert 22 has a limiting edge 221 at its bottom, and a limiting groove 311 is provided on the inner side of the rear inner mold 31. The limiting edge 221 is embedded in the limiting groove 311, so that the inner side of the rear inner mold 31 abuts against the outer side of the second insert 22. The upper outer side of the second insert 22 has an inclined surface 222, and the inner side of the push plate 32 has an inclined contact surface 321. The inclined contact surface 321 fits against the inclined surface 222, so that the inner side of the push plate 32 abuts against the outer side of the second insert 22. This achieves double support and enclosure of the second insert 22 within the mold from the rear inner mold 31 and the push plate 32, thus restricting the second insert 22 within the rear mold 3.

[0068] like Figures 2 to 3 As shown, the fastener 23 in this embodiment includes a first fixing block 231 and a second fixing block 232, which are fixed together by bolts. This means the fastener 23 is not a single-piece structure, but rather composed of the first fixing block 231 and the second fixing block 232, and fixed together by bolts. This modular design allows for flexible assembly and disassembly of the fastener 23. This makes maintenance, cleaning, or replacement of worn parts of the mold more convenient, improving the maintainability and service life of the mold.

[0069] The upper end of the first fixing block 231 abuts against the front mold 4, and the lower end of the second fixing block 232 abuts against the rear mold 3. When the mold is closed, the fixing component 23 provides dual, stable support and positioning in the vertical direction from both the front mold 4 and the rear mold 3. This bidirectional abutment mechanism ensures the high stability of the iron core stack 1 within the mold cavity. It effectively prevents the iron core stack 1 from axial displacement or tilting due to force during injection molding, thereby ensuring the accuracy of the overmolded iron core and avoiding defects such as incomplete injection or uneven glue distribution caused by inaccurate positioning of the iron core stack 1.

[0070] Preferably, the lower end of the second fixing block 232 is provided with a limiting groove 233, and the lower end protrusion of the iron core lamination abuts against the limiting groove 233. The limiting groove 233 restricts the displacement of the iron core lamination along the height direction of the second fixing block 232, thereby fixing the iron core lamination between the fixing member 23 and the first insert 21.

[0071] like Figures 2 to 3 As shown, the multi-piece pads of different thicknesses in this embodiment include a first pad 6, a second pad 7, a third pad 8, and a slider pad 9.

[0072] The first gasket 6, the third gasket 8, and the slider gasket 9 are all provided with thin sheet type and thick sheet type. The thickness of the thick sheet type is greater than that of the thin sheet type. The thickness of the second gasket 7 is fixed.

[0073] The first shim 6, the third shim 8, and the slider shim 9, with varying thicknesses, are combined with the second shim 7 to form multiple pre-selected shim combinations. This modular and pre-configured design allows the mold to achieve rapid and precise cavity size adjustments for different thickness deviations of the iron core lamination 1. This significantly simplifies the complexity of mold adaptability modifications and avoids the high cost and long lead time associated with customizing different mold inserts for each thickness deviation.

[0074] During the injection molding process, by selecting and installing the shim combination that best matches the thickness of the current iron core lamination 1, it can be ensured that the height or depth of the mold cavity precisely adapts to the actual total thickness of the iron core lamination 1. This precise adjustment capability fundamentally eliminates injection molding defects such as excessive glue, excessive glue thickness, incomplete filling, or insufficient filling caused by mismatched iron core lamination 1 thickness. The final product, an overmolded iron core, is free of burrs and meets the requirements for appearance and dimensions. This not only significantly improves product quality and yield but also effectively reduces material waste and subsequent processing costs caused by scrap.

[0075] like Figures 2 to 3 As shown, the specific method for installing the gasket in this embodiment is as follows:

[0076] The first washer 6 and the second washer 7 are disposed at the bottom of the second insert 22;

[0077] The third shim 8 is positioned at the bottom of the first insert 21 and abuts against the bottom of the second shim 7 and the bottom of the core stack 1, respectively. This shim installation method ensures precise support and positioning of the first insert 21 and the core stack 1 in the vertical direction within the mold cavity. It effectively absorbs and transmits the pressure from injection molding, preventing displacement or tilting of the core stack 1 in the vertical direction, thereby ensuring the dimensional accuracy of the overmolded core.

[0078] The slider washer 9 is positioned on the side of the sliding block 5 closest to the front inner mold 41. This allows the slider washer 9 to fit tightly with the front inner mold 41 when the mold is closed, working in conjunction with the sliding block 5 to provide lateral support and precise enclosure for the mold cavity. This is crucial for preventing horizontal deformation or flash (burrs) of the cavity during injection molding, further ensuring the appearance quality and dimensional accuracy of the overmolded injection core.

[0079] The specific method for matching gaskets in this embodiment is as follows:

[0080] a. Based on the actual total thickness T of the iron core lamination 1 实际 The ideal total core thickness T set by the mold 理想 Thickness deviation ΔT=T 实际 -T 理想 Determine the amount of movement ΔZ that the top surface of the first insert 21 needs to be adjusted. 镶件 , where ΔZ 镶件 =T理想 -T 实际 This approach transforms the abstract problem of uneven thickness into quantifiable mold adjustment targets. This quantitative analysis ensures the scientific rigor and precision of subsequent mold adjustments, providing clear guidance for eliminating product defects.

[0081] b. When the thickness deviation ΔT of core lamination 1 is less than 0, T 实际 <T 理想 This leads to ΔZ 镶件 If the value is greater than 0, the first insert 21 needs to be moved downwards. From the pre-selected shim combinations, the thick first shim 6, the thin third shim 8, and the thin slider shim 9 are selected, so that the total thickness change of the pre-selected shim combination is equal to the required adjustment amount ΔZ of the top surface of the first insert 21. 镶件 This matches, thereby achieving a corresponding reduction in the top surface of the first insert 21;

[0082] c. When the thickness deviation ΔT of the core lamination 1 is greater than 0, T 实际 >T 理想 This leads to ΔZ 镶件 If the thickness of the first insert 21 is less than 0, the first insert 21 needs to be moved upwards. From the pre-selected shim combinations, select the thin first shim 6, the thick third shim 8, and the thick slider shim 9, so that the total thickness change of the pre-selected shim combinations is equal to the required adjustment amount ΔZ of the top surface of the first insert 21. 镶件 This matches, thereby achieving a corresponding rise in the top surface of the first insert 21.

[0083] The total thickness change of the gasket assembly and the required adjustment ΔZ of the top surface of the first insert 21 are achieved. 镶件 Precise matching. Through this pre-set and reverse-cooperative method of selecting and combining shims, the height of the top surface of the first insert 21 is precisely raised or lowered, thereby changing the dimensions of the mold cavity. This allows the dimensions of the mold cavity to adapt to the actual thickness of the current iron core stack 1, thus completely eliminating injection molding defects such as excessive glue, excessive glue thickness, incomplete filling, or thinness. The final product is a glue-coated injection molded iron core without burrs, and its appearance and dimensions are all qualified. This method significantly improves the product qualification rate and reduces subsequent rework and material waste.

[0084] Example of gasket matching method:

[0085] Assuming the ideal total thickness T of the core lamination 1 理想 The thickness is 30.00 mm. To accommodate iron cores with different thickness deviations, the mold insert structure 2 is designed with replaceable shim combinations.

[0086] Gasket settings:

[0087] First gasket 6:

[0088] Thin sheet type: 0.5mm thick;

[0089] Thick sheet type: 1.0mm thick.

[0090] Third gasket 8:

[0091] Thin sheet type: 0.5mm thick;

[0092] Thick sheet type: 1.0mm thick.

[0093] Slider pad 9:

[0094] Thin sheet type: 0.5mm thick;

[0095] Thick sheet type: 1.0mm thick.

[0096] Scenario 1: The iron core lamination 1 is too thin.

[0097] Iron core pre-classification and inspection: Inspect a batch of iron core laminations 1 and measure their actual total thickness T. 实际 It is 29.80mm.

[0098] Calculate thickness deviation and adjustment amount: Calculate the thickness deviation ΔT and the required adjustment amount ΔZ for the top surface of the first insert 21. 镶件 .

[0099] Thickness deviation ΔT=T 实际 -T 理想 =29.80-30.00=-0.20mm.

[0100] ΔZ 镶件 =T 理想 -T 实际 =30.00-29.80=0.20mm.

[0101] Since ΔT < 0, the first insert 21 needs to be moved down by 0.20 mm.

[0102] Gasket matching and installation: due to the movement ΔZ 镶件 >0, select a combination of gaskets that can achieve the downward movement of insert structure 2.

[0103] Select the thick-plate type first gasket 6.

[0104] Select the thin-film type third gasket 8.

[0105] Select thin-plate slider pad 9.

[0106] This shim combination allows the top surface of the first insert 21 to be lowered by 0.20 mm, thereby matching the mold cavity size with the 29.80 mm thick iron core.

[0107] Scenario 2: The core lamination 1 is too thick.

[0108] Iron core pre-classification and inspection: Another batch of iron core laminations 1 was inspected, and its actual total thickness T was measured. 实际 It is 30.15mm.

[0109] Calculate thickness deviation and adjustment amount: Calculate the thickness deviation ΔT and the required adjustment amount ΔZ for the top surface of the first insert 21. 镶件 .

[0110] Thickness deviation ΔT=T 实际 -T 理想 =30.15-30.00=0.15mm.

[0111] ΔZ 镶件 =T 理想 -T 实际 =30.00-30.15=-0.15mm.

[0112] Since ΔT>0, the first insert 21 needs to be moved upward by 0.15mm.

[0113] Gasket matching and installation: due to the movement ΔZ 镶件 <0, select a combination of shims that can move the insert structure 2 upward.

[0114] Select the thin-film type first gasket 6.

[0115] Select the thick-plate type third gasket 8.

[0116] Select the thick-plate slider pad 9.

[0117] This shim combination allows the top surface of the first insert 21 to be raised by 0.15mm, thereby matching the mold cavity size with the 30.15mm thick iron core.

[0118] The core pre-classification step in this embodiment includes: sorting core lamination sets with different thickness deviation levels from largest to smallest quantity, and then selecting them sequentially as priority batches for overmolding injection molding. This quantity-based sorting and processing strategy maximizes the centralized processing of similar core laminations 1. This simplifies the frequency of mold shim combination replacement, as a larger batch of core laminations 1 can be processed after each replacement, thus significantly improving overall production efficiency. Simultaneously, by processing different batches in an orderly manner, all qualified batches of core laminations 1 can be effectively utilized, reducing waste and scrap rates of core laminations 1 due to thickness discrepancies, further lowering production costs.

[0119] In this embodiment, the thickness of the iron core lamination 1 is measured after compaction. The compaction pressure of the iron core lamination 1 is equal to the holding pressure of the overmolding injection mold. During thickness measurement, the iron core lamination 1 is placed under conditions similar to the pressure it experiences during actual injection molding. This pre-compaction test, which matches the actual injection molding conditions, yields more realistic and accurate final molding thickness data for the iron core lamination 1. This directly solves the problem of thickness measurement deviation caused by not considering the injection compaction effect in traditional methods. Accurate thickness data is the basis for precise matching of subsequent mold cavity dimensions, thereby eliminating defects such as incomplete injection and excess glue (burrs) caused by inaccurate dimensions of the iron core lamination 1, ultimately ensuring that the overmolded iron core is free of burrs and meets the requirements for appearance and dimensions.

[0120] Specifically, the compaction pressure of the iron core lamination 1 is 50-100 MPa. In actual use, the compaction pressure is such as 50 MPa, 60 MPa, 70 MPa, 80 MPa, 90 MPa, or 100 MPa. By setting a specific pressure range and making it consistent with the actual holding pressure, the high degree of fidelity and consistency of the iron core lamination 1 during measurement is ensured. This standardized measurement method, which simulates actual working conditions, effectively eliminates measurement errors caused by factors such as lamination gaps and elastic deformation, thereby obtaining iron core thickness data that is closest to the actual injection molding state. This fundamentally ensures the accuracy of subsequent mold cavity adjustments, directly eliminates injection molding defects such as excessive glue, incomplete glue filling, or burrs caused by inaccurate iron core dimensions, and ultimately ensures that the overmolded iron core is free of burrs and has qualified appearance and dimensions.

[0121] The above description is only a preferred embodiment of the present invention. For those skilled in the art, there will be changes in the specific implementation and application scope based on the ideas of the present invention. The content of this specification should not be construed as a limitation of the present invention.

Claims

1. A high-efficiency encapsulation injection molding method for the core of a stator or rotor in an electric machine, characterized in that, The method comprises the following steps: A. Core pre-classification: classify core laminations (1) into core lamination sets of different thickness deviation levels according to thickness; B. Mould structure preparation: the encapsulation injection mould comprises an insert structure (2) arranged in the back mould (3) or front mould (4) of the mould, the insert structure (2) is provided with multiple pieces of shims of different thicknesses for adjusting the size of the mould cavity, the multiple pieces of shims are stacked to form multiple pre-selected shim combinations, and the shim combinations are used for matching the core lamination sets of different thickness deviation levels; C. Shim matching and installation: according to the core lamination sets of different thickness deviation levels, select and install the pre-selected shim combinations matched therewith in the insert structure (2) to adjust the size of the mould cavity; D. Core loading: position and load the core laminations (1) into the mould cavity; E. Injection molding: close the mould and perform injection molding on the core laminations (1); The insert structure (2) comprises a first insert (21) and a second insert (22), The first insert (21) is internally provided with a cavity for accommodating the core laminations (1) to be encapsulated and injected; The first insert (21) is embedded in the inner side of the second insert (22); The cavity is provided with a fixing member (23), the upper end of the fixing member (23) abuts against the front mould (4), the lower end of the fixing member (23) abuts against the back mould (3), and the core laminations (1) are fixed between the fixing member (23) and the first insert (21); The multiple pieces of shims of different thicknesses comprise first shims (6), second shims (7), third shims (8) and slider shims (9); The first shims (6), the third shims (8) and the slider shims (9) are all provided with thin-shape and thick-shape, the thickness of the thick-shape is greater than that of the thin-shape, and the thickness of the second shims (7) is fixed; The first shims (6), the third shims (8) and the slider shims (9) of different thicknesses are combined with the second shims (7) to form multiple pre-selected shim combinations; The specific method for shim matching is: a. According to the actual total thickness T of the core lamination (1) 实际 to the ideal total thickness T of the core set by the mold 理想 The thickness deviation ΔT = T 实际 T 理想 , determine the movement amount ΔZ required for adjustment of the top surface of the first insert (21) 镶件 Where ΔZ 镶件 = T 理想 T 实际 ; b. When the iron core lamination (1) thickness deviation ΔT < 0, T 实际 <T 理想 , resulting in ΔZ 镶件 > 0, the first insert (21) needs to move down, in the pre-selected gasket combination, select the thick first gasket (6), the thin third gasket (8) and the thin sliding block gasket (9), so that the total thickness variation of the pre-selected gasket combination matches the movement amount ΔZ 镶件 of the first insert (21) top surface needs to be adjusted, so as to realize the corresponding reduction of the first insert (21) top surface; c. When the iron core lamination (1) thickness deviation ΔT > 0, T 实际 > T 理想 , resulting in ΔZ 镶件 < 0, the first insert (21) needs to move up, from the pre-selected gasket combination, select the thin first gasket (6), thick third gasket (8) and thick slider gasket (9), so that the total thickness variation of the pre-selected gasket combination matches the movement amount ΔZ 镶件 required for the adjustment of the top surface of the first insert (21), thereby achieving the corresponding elevation of the top surface of the first insert (21). The specific method for shim installation is: The first shims (6) and the second shims (7) are arranged at the bottom of the second insert (22); The third shims (8) are arranged at the bottom of the first insert (21) and abut against the bottom of the second shims (7) and the bottom of the core laminations (1) respectively; The slider shims (9) are arranged at the side of the sliding block (5) close to the front inner mould (41).

2. The efficient encapsulation injection molding method for the core of the rotor or stator in the motor according to claim 1, characterized in that, The front mould (4) is provided with a front inner mould (41) arranged at the inner side of the front mould (4); The back mould (3) is provided with a back inner mould (31) arranged at the inner side of the back mould (3) and a push plate (32) arranged at the end of the back inner mould (31) close to the front inner mould (41); The sliding block (5) is arranged between the front mould (4) and the back mould (3), the upper part of the sliding block (5) abuts against the front inner mould (41), and the lower part of the sliding block (5) abuts against the push plate (32). The front mold (4), the front inner mold (41), the rear mold (3), the rear inner mold (31), the push plate (32) and the sliding block (5) enclose to form a mold cavity.

3. The efficient rubber coating injection molding method for the rotor core of the motor rotor and stator according to claim 2, wherein one side end surface of the sliding block (5) is in contact with the outer side surface of the first insert (21). The inner side of the rear inner mold (31) and the inner side of the push plate (32) are in contact with the outer side surface of the second insert (22).

4. The efficient rubber coating injection molding method for the rotor core of the motor rotor and stator according to claim 1, wherein the fixing member (23) comprises a first fixing block (231) and a second fixing block (232), and the first fixing block (231) and the second fixing block (232) are fixed by bolts. The upper end of the first fixing block (231) is in contact with the front mold (4), and the lower end of the second fixing block (232) is in contact with the rear mold (3).

5. The efficient encapsulation injection molding method for the core of the rotor or stator in the motor according to claim 1, characterized in that, The core pre-classification step comprises: sorting the core lamination sets of different thickness deviation levels according to the number from more to less, and selecting them in turn as the priority rubber coating injection molding batch for processing.

6. The efficient encapsulation injection molding method for the core of the rotor or stator in the motor according to claim 1, characterized in that, The thickness of the core lamination (1) is detected after compaction, and the compaction pressure of the core lamination (1) is equal to the holding pressure of the rubber coating injection molding mold.

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