Stator core hot-pressing tool

Abstract

The utility model discloses a stator iron core hot-pressing tool, which comprises an upper die, a lower die, a limiting structure and a die sleeve, and is characterized in that the upper die and the lower die are matched to form a hot-pressing cavity for accommodating stator iron core scattered sheets, and respectively form an upper wall surface and a lower wall surface of the hot-pressing cavity; the upper wall surface and the lower wall surface are respectively used for pressing the upper surface and the lower surface of the stator iron core scattered sheet in the hot pressing process of the stator iron core scattered sheet; the limiting structure is at least partially arranged in the hot-pressing cavity, and the limiting structure is used for allowing the stator iron core scattered sheets to be inserted and used for pressing the inner side faces of the stator iron core scattered sheets in the hot-pressing process of the stator iron core scattered sheets; the die sleeve is at least partially arranged in the hot pressing cavity, the die sleeve is used for sleeving the outer surfaces of the stator iron core scattered sheets and pressing the outer surfaces of the stator iron core scattered sheets in the hot pressing process of the stator iron core scattered sheets, and the die sleeve is made of tungsten alloy. According to the technical scheme, the stator iron core hot-pressing tool can improve the yield of stator iron core hot-pressing molding.

Description

Technical Field

[0001] This utility model relates to the field of stator core manufacturing technology, and in particular to a stator core hot pressing tooling. Background Technology

[0002] The stator core is an important component of the stator and a major part of the motor's magnetic circuit.

[0003] During the production of stator cores, a hot pressing system is used to stack stator core laminations to obtain a stator core blank. This hot pressing process ensures that the stator core laminations within the blank are tightly bonded together to form a single, integral core. During the hot pressing of the stator core blank, hot pressing fixtures are typically used to fix the stator core laminations in place.

[0004] During the hot pressing process of stator cores, the stator core laminations undergo thermal deformation due to temperature and pressure. However, in current hot pressing processes, the deformation of the stator core laminations is limited by the hot pressing tooling, resulting in an uneven surface on the hot-pressed stator core, which makes it difficult to meet product quality requirements and leads to low product yield. Utility Model Content

[0005] The main purpose of this utility model is to propose a hot pressing fixture for stator cores, which aims to solve the problem of uneven surface and low yield rate during hot pressing of stator cores.

[0006] Problems arise when the coefficient of thermal expansion of the clamping fixture is too large or too small compared to the coefficient of thermal expansion of the stator core flasks.

[0007] To achieve the above objectives, the stator core hot pressing fixture proposed in this utility model includes:

[0008] upper mold;

[0009] The lower mold and the upper mold cooperate to form a hot pressing cavity, which is used to accommodate stator core pieces. The upper mold and the lower mold respectively form the upper wall surface and the lower wall surface of the hot pressing cavity. The upper wall surface and the lower wall surface are used to press the upper surface and the lower surface of the stator core pieces together during the hot pressing process. The lower mold and the upper mold are detachable.

[0010] A limiting structure, at least partially disposed within the hot pressing cavity, is used for inserting stator core laminations and for pressing the inner surfaces of the stator core laminations together during the hot pressing process; and

[0011] A mold sleeve, at least partially disposed within the hot pressing cavity, is used to fit over the outer surface of the stator core laminations and to press the outer surface of the stator core laminations together during the hot pressing process. The mold sleeve is made of tungsten alloy.

[0012] In some embodiments, the tungsten alloy is tungsten steel.

[0013] In some embodiments, the lower mold includes a positioning pad sleeve having a limiting cavity and an opening communicating with the limiting cavity, a portion of the cavity wall of the limiting cavity forming the cavity wall of the hot pressing cavity, the opening being formed on the end face of the lower mold facing the upper mold, and the upper mold being inserted into the limiting cavity through the opening.

[0014] In some embodiments, the cavity wall of the limiting cavity is provided with a slot, the mold sleeve is embedded in the slot, and the inner side of the mold sleeve is flush with the side wall of the limiting cavity.

[0015] In some embodiments, the positioning pad includes an upper pad, a middle pad, and a lower pad connected sequentially along the direction in which the upper mold is inserted into the lower mold. The upper pad forms the upper groove wall of the slot and fits against the upper end face of the mold sleeve. The middle pad forms the side groove wall of the slot and fits against the outer side face of the mold sleeve. The lower pad forms the lower groove wall of the slot and fits against the lower end face of the mold sleeve. The upper pad, the middle pad, and the lower pad are detachably connected.

[0016] In some embodiments, the limiting structure includes a first limiting post and a plurality of second limiting posts. One end of the first limiting post is disposed on the upper mold, and the other end extends toward the lower mold and into the hot pressing cavity. The limiting post is used to be inserted into the center hole of the stator core lamination and to press the end face of the winding post during the hot pressing process of the stator core lamination.

[0017] Multiple second limiting posts are arranged around the periphery of the first limiting post. One end of the second limiting post is located in the upper mold, and the other end extends toward the lower mold and into the hot pressing cavity. The second limiting post is used to be inserted into the tooth groove of the stator core lamination and to press the side of the winding post during the hot pressing of the stator core lamination.

[0018] In some embodiments, the lower mold further includes a pad sleeve, which is disposed at the bottom of the limiting cavity and forms the lower wall of the hot pressing cavity. The pad sleeve is provided with a first slot and a plurality of second slots. The other end of the first limiting post is inserted into the first slot, and the other ends of the plurality of second limiting posts are inserted into the plurality of second slots one by one.

[0019] In some embodiments, the upper mold includes a pressure cap and a material ejector sleeve stacked sequentially along the direction in which the upper mold is inserted into the lower mold. The first limiting post and the second limiting post are fixed to the pressure cap. The material ejector sleeve is provided with through holes for the first limiting post and the second limiting post to be inserted. The material ejector sleeve can move along the length direction of the first limiting post and the second limiting post. The material ejector sleeve forms the upper wall surface of the hot pressing cavity.

[0020] In some embodiments, the upper mold portion is located outside the lower mold, and the portion of the upper mold located outside the lower mold is provided with a force-applying structure.

[0021] In some embodiments, the force-applying structure is provided on both the pressure cap and the material ejection pad.

[0022] The stator core hot pressing fixture of this utility model limits the upper and lower surfaces of the stator core laminations through the upper and lower walls of the hot pressing chamber. The limiting structure also limits the inner side of the stator core laminations, ensuring that only the outer side deforms. A tungsten alloy mold is then fitted onto the outer surface of the stator core laminations. Since the thermal expansion coefficients of the stator core laminations and the tungsten alloy are close, the deformations of the stator core laminations and the mold are consistent under temperature and pressure conditions. This ensures that the inner side of the mold remains in close contact with the outer side of the stator core laminations without compressing the outer surface. Therefore, compared to existing clamping fixtures, the stator core hot pressing fixture of this application produces a smooth upper, lower, inner, and outer surface, improving the yield rate of stator core hot pressing. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the structure of an embodiment of the stator core hot pressing fixture of this utility model;

[0025] Figure 2 for Figure 1 Cross-sectional view of the hot pressing fixture for the middle stator core;

[0026] Figure 3 for Figure 1 A cross-sectional view of the stator core assemblies hidden in the middle;

[0027] Figure 4 for Figure 1 Exploded view of the hot pressing fixture for the middle stator core;

[0028] Figure 5 for Figure 4 Schematic diagram of the middle and lower mold structure;

[0029] Figure 6 for Figure 5 Sectional view of the middle and lower mold;

[0030] Figure 7 for Figure 5 A schematic diagram of the upper and middle molds and the limiting structure assembled into one unit;

[0031] Figure 8 for Figure 5 Side view of the upper and middle molds assembled with the limiting structure as a single unit.

[0032] Explanation of icon numbers:

[0033] 10. Upper mold; 10a. Force-applying structure; 11. Pressure cap; 12. Unloading pad; 20. Lower mold; 21. Positioning pad; 21. Positioning pad; 211. Upper pad; 212. Middle pad; 213. Lower pad; 214. Limiting cavity; 214a. Hot pressing cavity; 214b. Slot; 215. Opening; 216. Pad; 216a. First slot; 216b. Second slot; 30. Limiting structure; 31. First limiting post; 32. Second limiting post; 40. Mold sleeve; 50. Stator core sheet

[0034] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0035] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0036] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0037] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the meaning of "and / or" throughout the text is to include three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution that simultaneously satisfies A and B. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0038] This utility model proposes a hot pressing fixture for stator cores.

[0039] In the embodiments of this utility model, such as Figures 1 to 8 As shown, the stator core hot pressing fixture includes an upper mold 10, a lower mold 20, a limiting structure 30, and a mold sleeve 40.

[0040] Specifically, the upper mold 10 and the lower mold 20 are detachable. When the upper mold 10 and the lower mold 20 are assembled as a single unit, they cooperate to form a hot pressing cavity 214a. The upper mold 10 and the lower mold 20 respectively form the upper wall and lower wall of the hot pressing cavity 214a. Several stator core pieces 50 are placed in the hot pressing cavity 214a for pressurization and heating to solidify. The upper wall of the hot pressing cavity 214a is in contact with the upper surface of the stator core pieces 50, and the lower wall of the hot pressing cavity 214a is in contact with the lower surface of the stator core pieces 50. During the hot pressing process of the stator core pieces 50, the upper wall presses against the upper surface of the stator core pieces 50, and the lower wall presses against the lower surface of the stator core pieces 50. In this way, the upper and lower walls can limit the formation of the upper and lower surfaces of the stator core pieces 50.

[0041] It is worth noting that the upper surface of the stator core pieces pressed on the upper wall of the hot pressing cavity 214a refers to the uppermost stator core piece 50 among the several stator core pieces 50 pressed on the upper wall of the hot pressing cavity 214a, while the lower surface of the stator core pieces 50 pressed on the lower wall of the hot pressing cavity 214a refers to the lower surface of the lowermost stator core piece 50 among the several stator core pieces 50 pressed on the lower wall of the hot pressing cavity 214a.

[0042] A limiting structure 30 is disposed within the hot pressing chamber 214a, and stator core pieces 50 are inserted into the limiting structure 30 so that the outer surface of the limiting structure 30 fits against the inner surface of the stator core pieces 50. During the hot pressing process of the stator core pieces 50, the outer surface of the limiting structure 30 is pressed against the inner surface of the stator core pieces 50, thus preventing deformation of the inner surface of the stator core pieces 50 by limiting the movement of the limiting structure 30.

[0043] The limiting structure 30 can be selectively configured. In some embodiments, the limiting structure 30 is at least partially located within the hot pressing cavity 214a for inserting the stator core laminations 50. In another embodiment, the limiting structure 30 is entirely located within the hot pressing cavity 214a for inserting the stator core laminations 50. In short, as long as it allows for the insertion of the stator core laminations 50, it is acceptable. The specific configuration can be adjusted according to actual conditions, and this application does not impose any specific limitations on this.

[0044] The mold sleeve 40 is disposed within the hot pressing cavity 214a and is fitted onto the outer surface of the stator core laminations 50, with the inner side of the mold sleeve 40 fitting against the outer side of the stator core. During the hot pressing process of the stator core laminations 50, the inner side of the mold sleeve 40 is pressed against the outer side of the stator core. That is, through the upper wall surface, lower wall surface, limiting structure 30, and mold sleeve 40, the stator core laminations 50 can be limited in the vertical and horizontal directions and in the internal and external directions, achieving omnidirectional limiting of the stator core laminations 50. This prevents the stator core laminations 50 from deforming to one side during hot pressing, thereby improving the yield rate of hot-pressed stator cores.

[0045] Furthermore, the mold sleeve 40 is made of tungsten alloy. We know that tungsten alloy is a high-temperature material with good heat resistance. Specifically, the coefficient of thermal expansion of tungsten alloy is similar to that of the stator core fins, meaning that under the same temperature and pressure conditions, the deformation of the stator core fins 50 and the mold sleeve 40 is the same.

[0046] Specifically, currently, when it is necessary to hot press the stator core sheet 50, a hot pressing fixture is usually used to clamp the stator core sheet 50 to limit its position.

[0047] However, some existing hot pressing fixtures have some problems when clamping stator core laminations 50 for hot pressing.

[0048] For example, when the expansion coefficient of the hot pressing fixture is smaller than the thermal expansion coefficient of the stator core sheet, the hot pressing fixture will compress the outer surface of the stator core sheet 50, causing the stator core sheet 50 to deform in the vertical direction, resulting in uneven upper and lower surfaces of the formed stator core.

[0049] When the expansion coefficient of the clamping fixture is greater than that of the stator core flasks, the gap between the hot pressing fixture and the outer circumferential surface of the stator core flasks 50 is too large, resulting in an uneven outer surface of the formed stator core, which means that the yield of the produced stator core is low.

[0050] Based on the above reasons, the stator core hot-pressing fixture of this application, through the upper and lower walls and the limiting structure 30, limits the stator core segments 50 in the vertical and inner directions, ensuring that the stator core segments 50 can only deform on the outer side. Since the thermal expansion coefficient of the tungsten alloy is similar to that of the stator core segments, the deformation of the stator core segments 50 and the mold sleeve 40 is consistent under temperature and pressure conditions. This ensures that the inner side of the mold sleeve 40 and the outer side of the stator core segments 50 remain in close contact, without causing compression to the outer surface of the stator core segments 50. Optionally, the tungsten alloy can be tungsten steel.

[0051] The mold sleeve 40 can be selectively configured. In some embodiments, the mold sleeve 40 is at least partially located within the hot pressing cavity 214a, and the portion of the mold sleeve 40 located within the hot pressing cavity 214a is fitted onto the outer surface of the stator core laminations 50. In another embodiment, the mold sleeve 40 is entirely located within the hot pressing cavity 214a, and the entire mold sleeve 40 is fitted onto the outer surface of the stator core laminations 50. In summary, as long as the mold sleeve 40 can be completely fitted onto the outer surface of the stator core laminations 50, it is acceptable. The specific configuration can be adjusted according to actual conditions, and this application does not impose any specific limitations on this.

[0052] Specifically, the hot pressing forming of 50 stator core laminations includes the following stages:

[0053] (1) First stage of pressure heating and curing: Pressurize and heat 50 stator core pieces; wherein, the pressure is 0.1-0.3 N / mm2, the heating temperature is 100℃, and the time is 30s-3min;

[0054] (2) Second stage of pressure heating and curing: The stator core sheet 50 is further pressure heated; the pressure is 1-2 N / mm2, the heating temperature is 180-200℃, and the time is 3-5 min.

[0055] (3) Third stage of pressure heating and curing: The stator core 50 is further pressure heated; the pressure is 3-4 N / mm2, the heating temperature is 180-200℃, and the time is 3-5 min.

[0056] (4) Fourth stage pressurization: The stator core 50 is further pressurized without heating and cooled naturally; the pressurization pressure is 1-2 N / mm2.

[0057] During the hot pressing stage of the stator core sheet 50, the inner side of the mold sleeve 40 and the outer side of the stator core sheet 50 are always kept in close contact, and the outer surface of the stator core sheet 50 is not squeezed. This makes the upper surface, lower surface, inner side and outer side of the hot-pressed stator core flat, and improves the yield of hot pressing of the stator core.

[0058] In summary, the stator core hot-pressing fixture of this utility model limits the upper and lower surfaces of the stator core sheet 50 through the upper and lower walls of the hot-pressing cavity 214a, and the limiting structure 30 limits the inner side of the stator core sheet 50, so that the stator core sheet 50 can only deform on the outer side, and the tungsten alloy mold 40 is fitted onto the outer surface of the stator core sheet 50. Since the thermal expansion coefficient of the stator core sheet 50 is close to that of the tungsten alloy, the deformation of the stator core sheet 50 and the mold 40 under temperature and pressure conditions is consistent. This ensures that the inner side of the mold 40 and the outer side of the stator core sheet 50 are always in contact, and does not cause compression to the outer surface of the stator core sheet 50. It is evident that, compared to current clamping fixtures, the stator core hot-pressed using the stator core hot-pressing fixture of this application has a smoother upper surface, lower surface, inner surface, and outer surface, thus improving the yield rate of stator core hot-pressing.

[0059] Furthermore, the lower mold 20 includes a positioning pad 21, which has a limiting cavity 214 and an opening 215 communicating with the limiting cavity 214. Part of the cavity wall of the limiting cavity 214 forms the cavity wall of the hot pressing cavity 214a. The opening 215 is formed on the end face of the lower mold 20 facing the upper mold 10. The upper mold 10 is inserted into the limiting cavity 214 through the opening 215.

[0060] Specifically, such as Figure 3 and Figure 6 As shown, when the upper mold 10 is inserted into the positioning pad 21 through the opening 215, the upper mold 10 and the positioning pad 21 form a hot pressing cavity 214a. That is, when the upper mold 10 is inserted into the positioning pad 21 through the opening 215, a hot pressing cavity 214a is formed between the bottom surface of the upper mold 10 and the bottom wall of the limiting cavity 214. When the upper mold 10 is removed from the positioning pad 21, the positioning pad 21 becomes hollow, forming the limiting cavity 214. This design allows the positioning pad 21 to directly form the limiting cavity 214, resulting in better sealing of the limiting cavity 214 and a closer fit between the mold sleeve 40 and the outer surface of the stator core fins 50, which is beneficial for improving the yield of hot pressing of the stator core.

[0061] Of course, in other embodiments, the upper mold 10 has a limiting cavity 214 and an opening 215 communicating with the limiting cavity 214. The opening 215 forms the end face of the upper mold 10 facing the lower mold 20. Part of the cavity wall of the limiting cavity 214 forms the cavity wall of the hot pressing cavity 214a. The lower mold 20 is inserted into the limiting cavity 214 through the opening 215.

[0062] In some embodiments, the cavity wall of the limiting cavity 214 is provided with a slot 214b, the mold sleeve 40 is embedded in the slot 214b, and the inner side of the mold sleeve 40 is flush with the side wall of the limiting cavity 214.

[0063] Specifically, the slot 214b is annular, extending circumferentially along the limiting cavity 214. The mold sleeve 40 is embedded in the slot 214b, and the inner side of the mold sleeve 40 is flush with the cavity wall of the limiting cavity 214. That is, the outer surface of the stator core sheet 50 is flush with the outer side of the upper mold 10. This prevents the upper mold 10 from wobbling during the hot pressing process if the mold sleeve 40 protrudes from the cavity wall of the limiting cavity 214 and the side wall of the upper mold 10 is not limited. Conversely, if the inner side of the mold sleeve 40 is lower than the cavity wall of the limiting cavity 214, it will be inconvenient to remove or place the stator core sheet 50. In this embodiment, when the mold sleeve 40 is embedded in the slot 214b, the inner side of the mold sleeve 40 is flush with the cavity wall of the limiting cavity 214, so that the side wall of the upper mold 10 can be limited, and it is also convenient to place the stator core pieces 50 to be hot-pressed and the stator core after hot pressing.

[0064] Furthermore, the positioning pad 21 includes an upper pad 211 and a middle pad 212 connected sequentially along the direction in which the upper mold 10 is inserted into the lower mold 20. The upper pad 211 forms the upper groove wall of the slot 214b and fits against the upper end face of the mold sleeve 40. The middle pad 212 forms the side groove wall of the slot 214b and fits against the outer side face of the mold sleeve 40. The upper pad 211 and the middle pad 212 are detachably connected.

[0065] Specifically, when installing and removing the mold sleeve 40, the upper pad 211 and the middle pad 212 can be separated to create a notch at the upper end of the slot 214b. The user can then remove the mold sleeve 40 from or insert it into the slot 214b through this notch, reducing the difficulty of installing and removing the mold sleeve 40. The upper pad 211 and the middle pad 212 can be connected by snap-fit, threaded fasteners, or other methods.

[0066] Furthermore, the positioning pad 21 also includes a lower pad 213. The upper pad 211, middle pad 212, and lower pad 213 are sequentially connected along the direction in which the upper mold 10 is inserted into the lower mold 20. The lower pad 213 forms the lower groove wall of the slot 214b and fits against the lower end face of the mold sleeve 40. The lower pad 213 and the middle pad 212 are detachably connected. That is, the upper pad 211, middle pad 212, and lower pad 213 are sequentially connected and fitted along the direction in which the upper mold 10 is inserted into the lower mold 20 to form the slot 214b. When it is necessary to install and remove the mold sleeve 40, the lower pad 213 or the upper pad 211 can be removed to form a notch at one end of the slot 214b. The user can remove the mold sleeve 40 from the slot 214b or put the mold sleeve 40 into the slot 214b through the notch. This reduces the difficulty of installing and removing the mold sleeve 40. The lower pad 213 and the middle pad 212 can be connected by snap-fit, threaded fasteners, or other means. Of course, in other embodiments, one of the lower pad 213 and the upper pad 211 is fixedly connected to the middle pad 212, while the other is detachably connected to the middle pad 212.

[0067] In some embodiments, the limiting structure 30 includes a first limiting post 31 and a plurality of second limiting posts 32. One end of the first limiting post 31 and the plurality of second limiting posts 32 are disposed on the upper mold 10, and the other end extends to the lower mold 20 and into the hot pressing cavity 214a. The first limiting post 31 is used to be inserted into the center hole of the stator core sheet 50 and to press the end face of the winding column during the hot pressing of the stator core sheet 50. The plurality of second limiting posts 32 are arranged around the periphery of the first limiting post 31. The second limiting posts 32 are used to be inserted into the tooth groove of the stator core sheet 50 and to press the side surface of the winding column during the hot pressing of the stator core sheet 50.

[0068] Specifically, the stator core laminations 50 are inserted into the first limiting post 31 through the center hole. The outer surface of the first limiting post 31 is in contact with the end face of the winding post. During the hot pressing process of the stator core laminations 50, the outer surface of the first limiting post 31 is pressed against the end face of the winding post. In this way, the end face of the winding post of the stator core laminations 50 can be prevented from deforming by the limiting effect of the first limiting post 31.

[0069] On the stator core laminations 50, adjacent winding columns form a toothed groove. The number of second limiting posts 32 is the same as the number of toothed grooves. The stator core laminations 50 are inserted into the second limiting posts 32 through the toothed grooves. The outer surface of the second limiting post 32 is in contact with the side surface of the winding column. During the hot pressing process of the stator core laminations 50, the outer surface of the second limiting post 32 is pressed against the side surface of the winding column. In this way, the end face and side surface of the winding column are prevented from deforming by the limiting of the first limiting post 31 and multiple second limiting posts 32. That is, the end face and side surface of the hot-pressed stator core winding column are relatively flat, which is beneficial to improving the yield of hot-pressed stator cores.

[0070] In some embodiments, the lower mold 20 further includes a pad 216, which is disposed at the bottom of the limiting cavity 214 and forms the lower wall of the hot pressing cavity 214a. The pad 216 is provided with a first slot 216a and a plurality of second slots 216b. The other end of the first limiting post 31 is inserted into the first slot 216a, and the other ends of the plurality of second limiting posts 32 are inserted into the plurality of second slots 216b respectively.

[0071] Specifically, both the first slot 216a and the second slot 216b extend along the direction in which the upper mold 10 is inserted into the lower mold 20. The first limiting post 31 is inserted into the first slot 216a and moves within it. The second limiting post 32 is inserted into the second slot 216b and moves within it. During the hot pressing process, the first limiting post 31 and the second limiting post 32 are continuously inserted into the first slot 216a and the second slot 216b to avoid interference between the first limiting post 31 and the second limiting post 32 and the pad 216, which would affect the hot pressing effect. Of course, in other embodiments, the bottom wall of the limiting cavity 214 forms a first slot 216a and multiple second slots 216b. The other end of the first limiting post 31 is inserted into the first slot 216a, and the other ends of the multiple second limiting posts 32 are correspondingly inserted into the multiple second slots 216b.

[0072] In some embodiments, the upper mold 10 includes a pressure cap 11 and a material ejector sleeve 12 stacked sequentially along the direction in which the upper mold 10 is inserted into the lower mold 20. The first limiting post 31 and the second limiting post 32 are fixed to the pressure cap 11. The material ejector sleeve 12 is provided with a through hole for the first limiting post 31 and the second limiting post 32 to be inserted. The material ejector sleeve 12 can move along the length direction of the first limiting post 31. The material ejector sleeve 12 forms the upper wall surface of the hot pressing cavity 214a.

[0073] We know that the stator core after hot pressing is at a high temperature. By movably setting the ejector sleeve 12, when it is necessary to remove the hot-pressed stator core from the first limiting post 31 and the second limiting post 32, the ejector sleeve 12 can be moved, pushing the stator core to remove it from the first limiting post 31 and the second limiting post 32. This prevents the user's hand from coming into contact with the stator core, thus preventing burns. Of course, in other embodiments, the upper mold 10 only has a pressure cap 11.

[0074] In some embodiments, the upper mold 10 is located outside the lower mold 20, and the portion of the upper mold 10 located outside the lower mold 20 is provided with a force-applying structure 10a. The force-applying structure 10a is used to apply external force when separating the upper mold 10 and the lower mold 20. Specifically, the force-applying structure 10a can be configured as a protrusion on the upper mold 10, which can be held by a user's hand or used to abut against a tool. That is, when separating the upper mold 10 and the lower mold 20, the user can grasp the protrusion to separate the upper mold 10 and the lower mold 20, or push the protrusion with a tool to drive the upper mold 10 and the lower mold 20 to separate. This avoids the situation where the upper mold 10 is too smooth to pull apart when the user applies pulling force, thus preventing the upper mold 10 and the lower mold 20 from separating.

[0075] Of course, the force-applying structure 10a can also be configured as a groove recessed on the outer side of the upper mold 10, that is, when separating the upper mold 10 and the lower mold 20, the user can insert a tool into the groove and apply a pulling force to separate the upper mold 10 and the lower mold 20.

[0076] In this embodiment, the force-applying structure 10a is configured as a groove. After the stator core laminations 50 are clamped and hot-pressed, the upper mold 10 also has a certain temperature due to the heating. By configuring the force-applying structure 10a as a groove, the user can use a tool to separate the upper mold 10 and the lower mold 20 without having to use their hands, thus avoiding burns.

[0077] Furthermore, during the hot pressing process, the upper mold 10 continuously extends into the lower mold 20. By setting the force-applying structure 10a as a groove, interference between the force-applying structure 10a and the lower mold 20 can be avoided as the upper mold 10 extends into the lower mold 20. Of course, in other embodiments, the upper mold 10 may not have the force-applying structure 10a.

[0078] In some embodiments, both the pressure cap 11 and the ejector sleeve 12 have a force-applying structure 10a on their outer surfaces. That is, both the pressure cap 11 and the ejector sleeve 12 are exposed outside the lower mold 20. Users can separate the upper mold 10 and the lower mold 20 using the force-applying structure 10a on the pressure cap 11, or the ejector sleeve 12. The pressure cap 11 and the ejector sleeve 12 are stacked sequentially in the direction in which the upper mold 10 inserts into the lower mold 20, meaning the ejector sleeve 12 is located below the pressure cap 11. During the hot pressing process, the upper mold 10 continuously inserts into the lower mold 20. With the force-applying structure 10a on both the pressure cap 11 and the ejector sleeve 12, when the ejector sleeve 12 extends into the lower mold 20, the user can use a tool to engage the force-applying structure 10a on the pressure cap 11 to separate the upper mold 10 and the lower mold 20, improving the user experience. Of course, in other embodiments, the force-applying structure 10a is provided only on the pressure cap 11.

[0079] The above are merely preferred embodiments of this utility model and do not limit the patent scope of this utility model. Any equivalent structural transformations made based on the inventive concept of this utility model and the contents of the specification and drawings of this utility model, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this utility model.

Claims

1. A stator core hot pressing fixture, characterized in that, include: upper mold; The lower mold and the upper mold cooperate to form a hot pressing cavity, which is used to accommodate stator core pieces. The upper mold and the lower mold respectively form the upper wall surface and the lower wall surface of the hot pressing cavity. The upper wall surface and the lower wall surface are used to press the upper surface and the lower surface of the stator core pieces together during the hot pressing process. The lower mold and the upper mold are detachable. A limiting structure, at least partially disposed within the hot pressing cavity, is used for inserting stator core laminations and for pressing the inner surfaces of the stator core laminations together during the hot pressing process; and A mold sleeve, at least partially disposed within the hot pressing cavity, is used to fit over the outer surface of the stator core laminations and to press the outer surface of the stator core laminations together during the hot pressing process. The mold sleeve is made of tungsten alloy.

2. The stator core hot pressing fixture as described in claim 1, characterized in that, The tungsten alloy is tungsten steel.

3. The stator core hot pressing fixture as described in claim 1, characterized in that, The lower mold includes a positioning pad sleeve, the positioning pad sleeve having a limiting cavity and an opening communicating with the limiting cavity, a portion of the cavity wall of the limiting cavity forming the cavity wall of the hot pressing cavity, the opening being formed on the end face of the lower mold facing the upper mold, and the upper mold being inserted into the limiting cavity through the opening.

4. The stator core hot pressing fixture as described in claim 3, characterized in that, The cavity wall of the limiting cavity is provided with a slot, the mold sleeve is embedded in the slot, and the inner side of the mold sleeve is flush with the side wall of the limiting cavity.

5. The stator core hot pressing fixture as described in claim 4, characterized in that, The positioning pad sleeve includes an upper pad sleeve, a middle pad sleeve, and a lower pad sleeve connected sequentially along the direction in which the upper mold is inserted into the lower mold. The upper pad sleeve forms the upper groove wall of the slot and fits against the upper end face of the mold sleeve. The middle pad sleeve forms the side groove wall of the slot and fits against the outer side face of the mold sleeve. The lower pad sleeve forms the lower groove wall of the slot and fits against the lower end face of the mold sleeve. The upper pad sleeve, the middle pad sleeve, and the lower pad sleeve are detachably connected.

6. The stator core hot pressing fixture as described in claim 3, characterized in that, The limiting structure includes a first limiting post and multiple second limiting posts. One end of the first limiting post is located in the upper mold, and the other end extends toward the lower mold and into the hot pressing cavity. The limiting post is used to be inserted into the center hole of the stator core laminations and to press the end face of the winding post during the hot pressing process of the stator core laminations. Multiple second limiting posts are arranged around the periphery of the first limiting post. One end of the second limiting post is located in the upper mold, and the other end extends toward the lower mold and into the hot pressing cavity. The second limiting post is used to be inserted into the tooth groove of the stator core lamination and to press the side of the winding post during the hot pressing of the stator core lamination.

7. The stator core hot pressing fixture as described in claim 6, characterized in that, The lower mold also includes a pad sleeve, which is disposed at the bottom of the limiting cavity and forms the lower wall of the hot pressing cavity. The pad sleeve is provided with a first slot and a plurality of second slots. The other end of the first limiting post is inserted into the first slot, and the other ends of the plurality of second limiting posts are inserted into the plurality of second slots one by one.

8. The stator core hot pressing fixture as described in claim 6, characterized in that, The upper mold includes a pressure cover and a material ejector sleeve stacked sequentially along the direction in which the upper mold is inserted into the lower mold. The first limiting post and the second limiting post are fixed to the pressure cover. The material ejector sleeve is provided with through holes for the first limiting post and the second limiting post to be inserted. The material ejector sleeve can move along the length direction of the first limiting post and the second limiting post. The material ejector sleeve forms the upper wall surface of the hot pressing cavity.

9. The stator core hot pressing fixture as described in claim 8, characterized in that, The upper mold portion is located outside the lower mold, and the portion of the upper mold located outside the lower mold is provided with a force-applying structure.

10. The stator core hot pressing fixture as described in claim 9, characterized in that, The pressure cap and the material ejector sleeve are both provided with the force-applying structure.

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