An injection mold

Abstract

The application discloses an injection mold for injecting a high-voltage insulation layer on the periphery of a high-voltage winding preform to prepare a high-voltage winding, the injection mold comprising an upper mold and a lower mold, the upper mold and the lower mold being butted to form a cavity and a runner assembly, the cavity being shaped to match the outer surface of the high-voltage winding and used for placing the high-voltage winding preform for injection, and the inner wall of the cavity being provided with a glue inlet; the runner assembly is connected to the cavity through the glue inlet and used for conveying a molding material to the cavity, the runner assembly comprising at least one main runner, at least two branch runners and a mixing runner, the main runner, the branch runners and the mixing runner being connected in sequence along an injection advancing direction, and the cross-sectional area of the mixing runner gradually decreasing along the injection advancing direction. The injection mold can guarantee the uniform stability of the high-voltage insulation layer molding, effectively reduce the impact intensity of the molding material on the inner wall of the mold and the high-voltage winding preform when the molding material enters the cavity, guarantee the quality of the high-voltage winding and prolong the service life of the injection mold.

Description

Technical Field

[0001] This application relates to the field of high voltage winding injection molding, and in particular to an injection mold. Background Technology

[0002] Traditional high-voltage windings typically use resin casting to form the high-voltage insulation layer. During the casting process, air bubbles are easily generated, and it is difficult to remove all of them. After the resin cures, voids are formed inside the high-voltage winding, affecting the product's mechanical strength and insulation performance. Furthermore, it is difficult to maintain a completely uniform curing speed of the resin in different areas during the casting process, resulting in local hardness differences in the high-voltage winding, which in turn affects the consistency and stability of the overall product structure. In addition, it is difficult to accurately control the amount of resin used in casting, which can easily lead to material waste.

[0003] Although some high-voltage windings already use injection-molded high-voltage insulation layers, existing injection molds suffer from uneven distribution of injection raw materials due to improper flow channel design, which affects product quality. Furthermore, excessive injection pressure causes the injection raw materials to directly impact the inner wall of the mold and the internal coil structure, affecting mold life and the quality of the high-voltage winding. Utility Model Content

[0004] In view of the shortcomings of the prior art, the main purpose of this application is to provide an injection mold that, through the uniform distribution and buffer design of the flow channel, enables the molding material to enter the cavity evenly, ensuring the uniformity and stability of the high-voltage insulation layer molding, and effectively reducing the impact force of the molding material on the inner wall of the mold and the high-voltage winding preform when entering the cavity, ensuring the quality of the high-voltage winding and extending the life of the injection mold.

[0005] To solve the above-mentioned technical problems, the technical solution adopted in this application is: an injection mold for injecting a high-voltage insulation layer into the outer periphery of a high-voltage winding preform to prepare a high-voltage winding. The injection mold includes an upper mold and a lower mold, which are joined together to form a cavity and a runner assembly. The shape of the cavity matches the outer surface of the high-voltage winding and is used to place the high-voltage winding preform for injection. The inner wall of the cavity is provided with a sprue. The runner assembly is connected to the cavity through the sprue and is used to transport molding material to the cavity. The runner assembly includes at least one main runner, at least two branch runners, and a mixing runner. The main runner, branch runners, and mixing runner are connected sequentially along the injection direction, and the cross-sectional area of ​​the mixing runner gradually decreases along the injection direction.

[0006] The mixing channel includes a first mixing zone, a second mixing zone, and a third mixing zone connected sequentially along the injection direction. The cross-sectional area of ​​the first mixing zone gradually decreases along the injection direction, while the cross-sectional areas of the second and third mixing zones remain unchanged along the injection direction. The cross-sectional area of ​​the second mixing zone is equal to the end cross-sectional area of ​​the first mixing zone and greater than the cross-sectional area of ​​the third mixing zone.

[0007] The cavity is horizontally positioned along its axial direction.

[0008] The inlet includes a first inlet and a second inlet, which are respectively located on the inner walls of the horizontal axis of the cavity; the flow channel assembly includes a first flow channel assembly and a second flow channel assembly, the first flow channel assembly is connected to the cavity through the first inlet, and the second flow channel assembly is connected to the cavity through the second inlet.

[0009] The first flow channel assembly includes two first main flow channels, four first branch flow channels, eight third branch flow channels, and a first mixing flow channel. The outlet of each first main flow channel is simultaneously connected to the inlet of two first branch flow channels, the outlet of each first branch flow channel is simultaneously connected to the inlet of two third branch flow channels, and the outlets of the eight third branch flow channels are simultaneously connected to the eight inlets of the first mixing flow channel.

[0010] The cross-sectional areas of the first main channel, the first branch channel, and the third branch channel decrease sequentially.

[0011] The discharge ports of the eight third diversion channels are evenly spaced.

[0012] The second flow channel assembly consists of two components. Each second flow channel assembly includes a second main flow channel, two second branch flow channels, and a second mixing flow channel. The outlet of the second main flow channel is simultaneously connected to the inlet of the two second branch flow channels, and the outlet of the two second branch flow channels is simultaneously connected to the inlet of the second mixing flow channel.

[0013] The cross-sectional area of ​​the second main channel is larger than that of the second branch channel.

[0014] The inner wall of the cavity is also provided with at least one overflow port, which is used to detect whether the molding material in the cavity meets the injection requirements.

[0015] The beneficial effects of this application are: the injection mold of this application can make the molding material enter the cavity evenly through the uniform distribution and buffer design of the flow channel, ensuring the uniformity and stability of the high voltage insulation layer molding, and can effectively reduce the impact force of the molding material on the inner wall of the mold and the high voltage winding preform when entering the cavity, ensuring the quality of the high voltage winding and extending the life of the injection mold.

[0016] Meanwhile, the first and second injection ports of the injection mold in this application are respectively located on the inner walls of the cavity on both sides of the horizontal axis. By injecting glue from both sides at the same time, the balance of the injection filling of the molding material can be ensured, further ensuring the molding quality of the high voltage insulation layer, while reducing the injection filling time and improving production efficiency.

[0017] Furthermore, the cavity of the injection mold in this application is set horizontally along the axis, which allows for the horizontal installation of the core mold. This facilitates maintaining the same core mold installation direction as the injection process, the earlier winding process, and the later demolding process during the production of high-voltage windings, thus enabling mass production. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0019] Figure 1 This is a front view of a dry-type transformer 10 according to one embodiment of this application;

[0020] Figure 2 This is a top view of a dry-type transformer 10 according to one embodiment of this application;

[0021] Figure 3 yes Figure 2 Enlarged view of point G in the middle;

[0022] Figure 4 This is a three-dimensional schematic diagram of the winding body 1310 according to an embodiment of this application;

[0023] Figure 5 This is a perspective view of the winding body 1310 according to another embodiment of this application.

[0024] Figure 6 This is a perspective view of the high-voltage winding 130 according to one embodiment of this application;

[0025] Figure 7 This is a partial structural schematic diagram of the injection mold 200 in one embodiment of this application;

[0026] Figure 8 This is a partial structural schematic diagram of the injection mold 200 from another angle in one embodiment of this application;

[0027] Figure 9 This is a top view of the first flow channel assembly 310 in one embodiment of this application;

[0028] Figure 10 This is a side view of the first flow channel assembly 310 in one embodiment of this application;

[0029] Figure 11 yes Figure 10 Enlarged view of point H in the middle;

[0030] Figure 12 This is a top view of the second flow channel assembly 320 in one embodiment of this application. Detailed Implementation

[0031] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0032] like Figures 1 to 3 As shown, the dry-type transformer 10 is a three-phase transformer, with phases A, B and C respectively. That is, the dry-type transformer 10 includes three single-phase transformers, which are arranged in a straight line structure. The dry-type transformer 10 includes an iron core 110, a low-voltage winding 120 and a high-voltage winding 130.

[0033] The iron core 110 includes three columnar iron core bodies, an upper yoke located at the upper end of the three columnar iron core bodies, and a lower yoke located at the lower end of the three columnar iron core bodies. The low-voltage winding 120 includes copper foil 121, a low-voltage insulation layer 122, and a support bar 123, with the copper foil 121 and the low-voltage insulation layer 122 alternately arranged. The copper foil 121 is formed by winding a whole sheet of copper foil paper, and the low-voltage insulation layer 122 is overlapped with the copper foil 121 and wound together, thus achieving the alternating arrangement of the copper foil 121 and the low-voltage insulation layer 122.

[0034] Combination Figures 4-6 As shown, the high-voltage winding 130 includes a winding body 1310, a high-voltage coil, and a high-voltage insulation layer 1330. The conductor is wound on the winding body 1310 to form the high-voltage coil. The high-voltage coil includes several coil segments, which are spaced apart along the axial direction of the winding body 1310.

[0035] In one embodiment, see Figure 4 The winding body 1310 adopts a fixed winding structure. Specifically, the winding body 1310 includes several winding plates 1313 and several auxiliary components 1311. The winding plates 1313 are arranged along the axial direction of the winding body 1310 and are evenly distributed around the circumference of the winding body 1310. The auxiliary components 1311 are annular and spaced apart along the axial direction of the winding body 1310. The auxiliary components 1311 are snap-fitted to the winding plates 1313. The winding plates 1313 are fixed comb plates, that is, several winding grooves 1314 are provided on the winding plates 1313 so that several comb teeth are formed on one side of the winding plates 1313 for winding wires. At least one section of coil is provided between two adjacent comb teeth on the winding plates 1313, so that each winding groove 1314 is wound with wires. The high-voltage coils are reasonably distributed and the sections of coils are spaced apart, resulting in balanced force and good mechanical strength.

[0036] In another embodiment, see Figure 5 The winding body 1310 adopts a movable winding structure. The winding body 1310 includes several winding plates 1313, several winding elements 2314, and several auxiliary elements 1311. The structure of the auxiliary elements 1311 and their connection with the winding plates 1313 are as described above and will not be repeated here. Several winding elements 2314 are provided on the winding plates 1313, movable along the winding plate 1313. A winding groove 1314 is formed between two adjacent winding elements 2314 on the winding plate 1313 for winding the conductor. At least one section of coil is provided between two adjacent winding elements 2314 on the winding plate 1313, ensuring that each winding groove 1314 is wound with a conductor, and that the high-voltage coils are reasonably distributed and spaced apart.

[0037] Continue reading Figures 4-6 A high-voltage coil is formed by circumferentially winding conductors around the outer circumferential surface of the winding body 1310. Specifically, the winding body 1310 is pre-mounted on a horizontally placed mandrel, the outline of which matches the inner surface shape of the high-voltage winding 130, so that the winding body 1310 is placed horizontally along its axial direction. The conductors are wound from one end of the winding body 1310 to the other end to form a high-voltage coil, ensuring the consistency of the conductor direction and the winding accuracy, thereby improving winding efficiency and the quality of the high-voltage winding 130. By winding from the winding groove 1314 at one end of the winding body 1310 to the winding groove 1314 at the other end, the high-voltage coils are spaced apart along the axial direction of the winding body 1310. After winding, the conductors form two external connections at their beginning and end, namely the first external connection D and the second external connection X. The first external connection D is used to connect cables, and the second external connection X is used to connect other external connections, such as in a three-phase transformer, for interconnection with other phase transformers. Six taps extend from the center of the winding body 1310 along its axial direction: tap 2, tap 3, tap 4, tap 5, tap 6, and tap 7. These six taps form a tap changer. For ease of description, taps 2, 4, and 6 are defined as the first tap changer, and taps 3, 5, and 7 are defined as the second tap changer. The first and second tap changers are arranged parallel to each other. The six taps form the tapping device for the high-voltage coil, used by the dry-type transformer 10 to adjust the voltage according to different operating conditions.

[0038] When the wire is wound, it is wound in a winding groove 1314 corresponding to all the winding plates 1313, so that each coil formed by the wire is perpendicular to the axis of the winding body 1310. The winding is convenient and the wire is neatly arranged. The winding plate 1313 is subjected to uniform force and has good mechanical strength.

[0039] The high-voltage insulation layer 1330, which is made of high-temperature vulcanized silicone rubber, forms the high-voltage winding 130 after wrapping the high-voltage coil and the winding body 1310. Specifically, the winding body 1310 with the high-voltage coil is used as a preform of the high-voltage winding. The preform, along with the mandrel, is placed into the injection mold 200 of the injection molding machine to begin the injection process. The injection molding machine injects molding material (silicone rubber raw material) into the cavity of the injection mold 200. Specifically, the molding material is injected into the cavity of the injection mold 200 through the injection tube of the injection molding machine and the flow channel assembly 300. The high-voltage insulation layer 1330 is formed on the outer periphery of the high-voltage winding preform, resulting in the high-voltage winding 130. The high-voltage insulation layer 1330 uses high-temperature vulcanized silicone rubber, which improves the overall insulation and mechanical properties of the high-voltage winding 130.

[0040] Combination Figures 7 to 8 This application also provides an injection mold 200 for injecting a high-voltage insulation layer 1330 onto the outer periphery of a high-voltage winding preform to prepare a high-voltage winding 130. The injection mold 200 includes an upper mold and a lower mold, which are joined to form a cavity and a runner assembly 300. The shape of the cavity matches the outer surface of the high-voltage winding 130 and is used to place the high-voltage winding preform for injection. The inner wall of the cavity is provided with a sprue. The runner assembly 300 is connected to the cavity through the sprue and is used to transport the molding material to the cavity. The runner assembly 300 includes at least one main runner, at least two branch runners, and a mixing runner. The main runner, branch runners, and mixing runner are connected sequentially along the injection advance direction, and the cross-sectional area of ​​the mixing runner gradually decreases along the injection advance direction. For ease of description, the flow direction of the molding material in the injection mold 200 during injection is defined as the injection advance direction, the horizontal dimension of each runner cross-section is defined as its width, and the vertical dimension of each runner cross-section is defined as its depth. The injection mold 200 of this application, through the uniform distribution and buffer design of the flow channel, enables the molding material to enter the cavity evenly, ensuring the uniformity and stability of the high voltage insulation layer 1330 molding, and effectively reducing the impact force of the molding material on the inner wall of the mold and the high voltage winding preform when entering the cavity, ensuring the quality of the high voltage winding 130 and extending the service life of the injection mold 200.

[0041] The injection mold 200 is placed horizontally along its axis, meaning the cavity is set horizontally along its axis. After the high-voltage coil is wound, the horizontally placed core mold along with the high-voltage winding preform can be directly transferred into the horizontally set cavity for injection without adjusting the direction. After injection, the core mold in the cavity along with the high-voltage winding 130 can be directly installed into the horizontally placed demolding machine for demolding without adjusting the direction. This ensures that the winding, injection, and demolding processes are all carried out in the same direction, making operation convenient and reducing the product transfer time between different workstations, thereby improving production efficiency and product quality. When the high-voltage winding preform is placed horizontally along its axial direction in the injection mold 200, the first external connector D, the second external connector X, and the six taps are all located on the same vertical plane, and the first external connector D and the second external connector X are located on the same horizontal line. The first external connector D and the second external connector X are respectively connected to the output terminals. The output terminals can be further connected to the injection mold 200 through a locking device, thereby connecting the first external connector D and the second external connector X to the injection mold 200. At the same time, the six taps are connected to the injection mold 200 through the tooling connector. On the one hand, this keeps the position of the high-voltage winding preform in the cavity fixed, ensuring the injection molding quality. On the other hand, it prevents the two external connectors and the six taps from being covered by the molding material during the injection process and thus unable to be used for wiring. The locking device, output terminals, and tooling connector can be structures from the prior art, as long as they can accurately position the high-voltage winding preform in the cavity of the injection mold 200. No specific restrictions are imposed here.

[0042] The inlet ports include a first inlet port 301 and a second inlet port 302, which are respectively disposed on the inner walls of the horizontal axial sides of the cavity. The flow channel assembly 300 includes a first flow channel assembly 310 and a second flow channel assembly 320. The first flow channel assembly 310 is connected to the cavity through the first inlet port 301, and the second flow channel assembly 320 is connected to the cavity through the second inlet port 302. The second inlet port 302 is located on the same side of the cavity as the first external connector D, the second external connector X, and the six taps. To avoid interference between the second flow channel assembly 320 and the locking device and the tooling connector, there are two second inlets 302, which correspond to the areas between the two locking devices and the tooling connectors fixed on the high-voltage winding preform. That is, on one side of the high-voltage winding preform, the locking device for fixing the first external connector D, one of the second inlets 302, the tooling connector for fixing the six taps, the other second inlet port 302, and the locking device for fixing the second external connector X are arranged in sequence at intervals. The first inlet 301 is located on the other side of the cavity. Since there are no external connectors or taps on this side, and there is no need to consider assembly interference with the locking device, tooling connectors, or other connection structures, the first inlet 301 is set to be one, which simplifies the inlet structure on this side and reduces manufacturing costs.

[0043] Both the first inlet 301 and the second inlet 302 have flat rectangular cross-sections. The lengths of both inlets 301 and 302 are horizontal, ensuring that the molding material can be uniformly injected into the cavity on the same horizontal plane. The length of the first inlet 301 is equal to the axial length of the cavity, ensuring that the molding material can be uniformly injected into the cavity along its entire axial length, avoiding uneven filling in certain areas. Simultaneously, it allows the molding material to quickly enter and disperse within the cavity, shortening the filling time and improving injection efficiency. The length of the second inlet 302 is slightly less than the distance between the locking device and the tooling connector. While ensuring that the second flow channel assembly 320 does not interfere with the locking device and tooling connector, the length of the second inlet 302 is maximized to improve injection efficiency. The simultaneous injection of glue through the first injection port 301 and the second injection port 302 can, on the one hand, balance the injection pressure distribution and prevent local force shift of the high-voltage winding preform during injection, which could lead to deformation of the internal structure of the high-voltage winding 130; on the other hand, it can ensure that the molding material is quickly and evenly distributed to fill the cavity, avoiding problems such as uneven distribution of molding material.

[0044] Furthermore, the injection mold 200 is connected to a temperature control device to control the temperature of the molding material, ensuring it always meets the process conditions required for injection molding. The temperature control device includes a heating system and multiple temperature sensors. When operating, the temperature control device measures the actual temperature at various points on the injection mold 200 using the temperature sensors and determines whether the injection mold 200 needs to be heated or cooled, feeding this information back to the heating system for appropriate action. If the actual temperature is lower than the set temperature, the injection mold 200 needs to be heated, and the heating system heats the injection mold 200 until the actual temperature reaches the set temperature. If the actual temperature is higher than the set temperature, the injection mold 200 needs to be cooled, and the heating system stops heating until the actual temperature reaches the set temperature. Through this temperature control device, real-time monitoring and precise control of the molding material temperature within the cavity can be achieved, avoiding problems such as uneven curing caused by localized overheating and ensuring the quality of the high-voltage winding 130 after molding.

[0045] The inner wall of the cavity is also provided with at least one overflow port for detecting whether the molding material in the cavity meets the injection requirements, that is, whether the molding material filling the cavity is sufficient. In this embodiment, there are three overflow ports, evenly distributed on the inner wall at the top of the cavity. When the molding material fills the cavity and reaches the overflow port, the excess molding material will be discharged through the overflow port. When molding material overflows from each overflow port, it indicates that the molding material filling the cavity is sufficient. In other embodiments, there may be one, two, four or more overflow ports, as long as they can detect whether the molding material in the cavity meets the injection requirements, and there is no limitation here.

[0046] Combination Figures 9 to 11The first runner assembly 310 includes two first main runners 311, four first branch runners 312, eight third branch runners 313, and a first mixing runner 314. The inlets into the first main runners 311, first branch runners 312, third branch runners 313, and first mixing runners 314 along the injection advance direction are defined as their feed ports, and the outlets are defined as their discharge ports. Each feed port of the first main runner 311 is connected to the injection molding machine's injection tube. Each discharge port of the first main runner 311 is simultaneously connected to the feed ports of two first branch runners 312. Each discharge port of the first branch runner 312 is simultaneously connected to the feed ports of two third branch runners 313. The discharge ports of the eight third branch runners 313 are simultaneously connected to the eight feed ports of the first mixing runners 314. This ensures that the first main runners 311, first branch runners 312, third branch runners 313, first mixing runners 314, and the mold cavity are sequentially connected. During injection, the injection molding machine injects the molding material into the flow channel assembly 300 through the injection tube. The molding material first enters two first main flow channels 311 and then undergoes a first split through four first branch channels 312, resulting in four streams of molding material. Then, it undergoes a second split through eight third branch channels 313, resulting in eight streams of molding material. Finally, the eight streams of molding material converge into the first mixing channel 314 for mixing and flow into the mold cavity. By performing two splits on the molding material, it is evenly divided into multiple small streams, reducing flow resistance and injection pressure loss. This eliminates the need for the injection molding machine to apply excessive pressure to propel the molding material, thus reducing energy consumption. Furthermore, the mixing of the split molding material further homogenizes it, ensuring uniform distribution of all components and preventing uneven curing caused by localized component inconsistencies, which could ultimately lead to product defects in the high-voltage winding 130. In other embodiments, the first main channel can be set to one, three or more, the number of the first branch channels can be set to three or more times the number of the first main channel, the number of the third branch channels can be set to three or more times the number of the first branch channels, or the molding material can be branched three or more times, as long as the conveying requirements of the molding material can be met, and there is no limitation here.

[0047] The cross-sectional areas of the first main channel 311, the first branch channel 312, and the third branch channel 313 decrease sequentially. The first main channel 311 has a larger cross-sectional area, ensuring sufficient flow capacity to guide the molding material in the injection tube into the first channel assembly 310 at an appropriate flow rate, avoiding turbulence caused by excessively high flow rates due to a small cross-sectional area. The cross-sectional area of ​​the first branch channel 312 is smaller than that of the first main channel 311, and the cross-sectional area of ​​the third branch channel 313 is further reduced. This ensures that the cross-sectional area of ​​each channel matches the capacity of the molding material flowing within it, ensuring that the flow rates of the molding material in the first main channel 311, the first branch channel 312, and the third branch channel 313 are relatively consistent. This guarantees the flow stability of the molding material in the first channel assembly 310, avoiding localized underfill or overfilling problems caused by flow rate differences, and also helps to balance the injection pressure of each part, reducing unnecessary pressure loss.

[0048] In this embodiment, the first main channel 311, the first branch channel 312, and the third branch channel 313 have the same depth, and their widths decrease sequentially, so that the cross-sectional areas of the first main channel 311, the first branch channel 312, and the third branch channel 313 decrease sequentially. In other embodiments, the first main channel, the first branch channel, and the third branch channel can be set to have the same width and decreasing depth, or the width and depth of the first main channel, the first branch channel, and the third branch channel can all decrease, as long as the conveying requirements of the molding material can be met, and no specific limitation is made here.

[0049] To ensure that the molding material can achieve smooth diversion and uniform convergence in the first flow channel assembly 310, the first main flow channel 311, the first branch flow channel 312, and the third branch flow channel 313 are all non-linear flow channels, and the discharge ports of the eight third branch flow channels 313 are evenly spaced.

[0050] The first branch channel 312 includes a smoothly connected first straight section 3121 and a first curved section 3122. The first straight section 3121 connects to the first main channel 311, and the first curved section 3122 connects to the third branch channel 313. The first curved section 3122 and the first straight section 3121 are connected by a rounded corner, ensuring the smooth flow of the molding material in the channel. The angle between the first curved section 3122 and the first straight section 3121 is defined as the first curvature angle, which is 110°. The third branch channel 313 has a structure that is basically similar to that of the first branch channel 312, and will not be described in detail here. Both the third branch channel 313 and the first branch channel 312 play a role in smoothly branching and turning the molding material, ultimately causing the eight streams of molding material to converge evenly into the first mixing channel 314.

[0051] Two first main channels 311 are spaced apart, and the inlet of the first main channel 311 corresponds to the position of the dispensing tube. Each first main channel 311 includes at least one smoothly connected second straight segment 3111 and at least two second curved segments 3112. In this embodiment, the first main channel 311 includes the second straight segment 3111 and the two second curved segments 3112 connected in sequence, making the first main channel 311 approximately S-shaped. The angle between the second straight segment 3111 and the connected second curved segment 3112 is defined as the second curvature angle, which is 110°. The angle between the two second curved segments 3112 is defined as the third curvature angle, which is also 110°. The inlet and outlet of the first main channel 311 are parallel in direction. The connection between the second straight segment 3111 and the second curved segment 3112 also uses a rounded transition connection to ensure the smoothness of the molding material's flow direction in the channel.

[0052] In this embodiment, the cross-sections of the first main channel 311, the first branch channel 312, and the third branch channel 313 are all capsule-shaped. In other embodiments, the cross-sections of the first main channel, the first branch channel, and the third branch channel can all be circular, trapezoidal, or rectangular, or they can be different, as long as they can meet the requirements for conveying the molding material. In addition, the bending angle of each channel can be adjusted according to the injection requirements, which is not limited here.

[0053] One end of the first mixing channel 314 has eight inlets, which are respectively connected to eight third branch channels 313. The other end is connected to the mold cavity through the first glue inlet 301. The first mixing channel 314 allows the molding material to be mixed again after being diverted through the first main channel 311, the first branch channel 312 and the third branch channel 313. This achieves further homogenization of the molding material, ensures the uniform distribution of each component in the molding material, and avoids uneven curing caused by uneven local components, which could ultimately lead to product defects in the high-voltage winding 130.

[0054] In this embodiment, the cross-sectional area of ​​the first mixing channel 314 gradually decreases along the injection advance direction. The first mixing channel 314 includes a first mixing region 3141, a second mixing region 3142, and a third mixing region 3143 connected sequentially along the injection advance direction. The cross-sectional area of ​​the first mixing region 3141 gradually decreases along the injection advance direction, while the cross-sectional areas of the second mixing region 3142 and the third mixing region 3143 remain unchanged along the injection advance direction. The minimum cross-sectional area at the end of the first mixing region 3141 along the injection advance direction is defined as the end cross-sectional area of ​​the first mixing region 3141. The cross-sectional area of ​​the second mixing region 3142 is equal to the end cross-sectional area of ​​the first mixing region 3141 and greater than the cross-sectional area of ​​the third mixing region 3143, thereby causing the cross-sectional area of ​​the first mixing channel 314 to gradually decrease. The maximum depth of the first mixing zone 3141 at its beginning along the injection direction is defined as the beginning depth of the first mixing zone 3141. The beginning depth of the first mixing zone 3141 is equal to the depth of the third branch channel 313, so that the molding material can smoothly enter the first mixing channel 314, reduce the retention phenomenon, and optimize the flow of the molding material.

[0055] In this process, the cross-sectional area of ​​the first mixing zone 3141 gradually decreases along the injection direction. For example, the width of the first mixing zone 3141 remains constant along the injection direction, while the depth gradually decreases along the injection direction, thus forming a sloping first stop end 3144. When the molding material flows out of the third branch channel 313, the injection pressure is relatively high. After impacting the first stop end 3144, the flow direction can be changed, the flow rate can be slowed down, and the molding material can be fully mixed in the first mixing channel 314, thereby improving the uniformity of each component in the molding material and ensuring product quality. The cross-sectional areas of the second mixing zone 3142 and the third mixing zone 3143 remain constant along the injection direction, but the cross-sectional area of ​​the second mixing zone 3142 is larger than that of the third mixing zone 3143. For example, their widths remain constant along the injection direction, but the depth of the second mixing zone 3142 is greater than that of the third mixing zone 3143. This forms a second stop end 3145 at the end of the second mixing zone 3142. After the molding material impacts the second stop end 3145, its flow direction changes again, slowing down the flow rate and ensuring thorough mixing, further improving the uniformity of the components in the molding material. Furthermore, the first mixing channel 314 also includes a buffer zone 3146, which is located between the inlet of the first mixing channel 314 and the first mixing zone 3141. That is, the buffer zone 3146, the first mixing zone 3141, the second mixing zone 3142, and the third mixing zone 3143 are arranged sequentially along the injection direction. The cross-sectional area of ​​the buffer zone 3146 is larger than the total cross-sectional area of ​​each of the third branch channels 313. The depth of the buffer zone 3146 remains constant and is equal to the depth of the third branch channels 313 and the depth of the first mixing zone 3141. However, the width of the buffer zone 3146 is much larger than the width of the third branch channels 313, so that the molding material can smoothly transition through the buffer zone 3146 before entering the first mixing zone 3141, reducing the impact of the molding material on the first stop end 3144. In addition, the buffer zone 3146 provides sufficient space to adjust the injection pressure of the molding material, so that the fluid pressure entering the subsequent area is not too high, avoiding the generation of local high pressure areas.

[0056] In this embodiment, the width of the first mixing channel 314 remains unchanged, that is, the widths of the second mixing zone 3142 and the third mixing zone 3143 are the same, and the width of the first mixing channel 314 is equal to the length of the cavity along the axial direction. This makes the width of the first mixing channel 314 much larger than the sum of the widths of the eight first sub-channels 313, and the capacity of the first mixing channel 314 much larger than the sum of the capacities of the eight third sub-channels 313. This can effectively reduce the injection pressure when the molding material enters the cavity, prevent the molding material from impacting the high-voltage winding preform and causing it to shift, thus affecting product quality. It can also reduce the wear of the mold caused by the injection pressure and extend the mold life.

[0057] In other embodiments, the first mixing channel may include only a first mixing region, the cross-sectional area of ​​which gradually decreases; the first mixing channel may also include two, three or more mixing regions, the cross-sectional area of ​​each mixing region remains unchanged along the injection advance direction, but the cross-sectional areas of multiple mixing regions gradually decrease along the injection advance direction, the degree of decrease may be equal or unequal, as long as the depth of the first mixing channel gradually decreases along the injection advance direction to meet the injection requirements, there is no limitation here.

[0058] The first runner assembly 310 adopts a symmetrical layout design to ensure that the molding material is evenly distributed to both sides when entering the first runner assembly 310, avoiding flow velocity differences caused by asymmetry of the runners. Specifically, the two first main runners 311, four first branch runners 312, and eight third branch runners 313 are arranged in a mirror-symmetrical manner to ensure that the flow direction and pressure distribution of the molding material in each runner are spatially symmetrical. At the same time, the four first branch runners 312 and the eight third branch runners 313 adopt a balanced arrangement strategy, that is, the outlet spacing of the four first branch runners 312 is approximately the same, and the outlet spacing of the eight third branch runners 313 is approximately the same, so that the first runner assembly 310 forms a symmetrical tree structure, which makes the flow resistance of each runner reach a dynamic balance, effectively suppressing eddies and pressure fluctuations, and ensuring injection molding quality.

[0059] Combination Figure 12Two second flow channel components 320 are provided, each connected to a second inlet 302. Each second flow channel component 320 includes a second main flow channel 321, two second branch flow channels 322, and a second mixing flow channel 323. The inlet end from which the molding material flows into the second main flow channel 321, the second branch flow channel 322, and the second mixing flow channel 323 along the injection advance direction is defined as its feed port, and the outlet is defined as its discharge port. The feed port of the second main flow channel 321 is connected to the injection tube of the injection machine. The discharge port of the second main flow channel 321 is simultaneously connected to the feed ports of the two second branch flow channels 322, and the discharge ports of the two second branch flow channels 322 are simultaneously connected to the two feed ports of the second mixing flow channel 323. In this way, the second main flow channel 321, the second branch flow channels 322, the second mixing flow channel 323, and the cavity are connected in sequence. During injection, the injection molding machine injects the molding material into the flow channel assembly 300 through the injection tube. The molding material first enters two second main flow channels 321 and is then divided into four streams by four second branch flow channels 322. Finally, the four streams of molding material converge into two second mixing flow channels 323 for mixing and flow into the mold cavity. By dividing the molding material, it is evenly divided into multiple small streams, reducing flow resistance and injection pressure loss. Furthermore, by mixing the divided molding material, it achieves further homogenization, ensuring uniform distribution of all components and preventing uneven curing caused by localized component inconsistencies, which could ultimately lead to product defects in the high-voltage winding 130. In other embodiments, the second flow channel assembly can be configured as one, three, or more, and correspondingly, the second main flow channel can be configured as one, three, or more. The number of second branch flow channels can be three times or more than the number of second main flow channels, as long as the molding material can be transported; no limitation is imposed here.

[0060] The cross-sectional area of ​​the second main channel 321 is larger than that of the second branch channel 322. The larger cross-sectional area of ​​the second main channel 321 ensures sufficient flow capacity, facilitating the guidance of the molding material in the injection tube to enter the second channel assembly 320 at an appropriate flow rate. This avoids turbulence caused by excessively high flow rates of the molding material due to a small cross-sectional area. The smaller cross-sectional area of ​​the second branch channel 322 ensures that the cross-sectional area of ​​each channel matches the capacity of the molding material flowing within it. This ensures that the flow rates of the molding material in the second main channel 321 and the second branch channel 322 are comparable, thereby guaranteeing the flow stability of the molding material in the second channel assembly 320. This avoids localized underfilling or overfilling problems caused by flow rate differences and helps balance the pressure distribution in different parts, reducing unnecessary pressure loss.

[0061] In this embodiment, the second main channel 321 and the second branch channel 322 have the same depth, but the width of the second main channel 321 is greater than the width of the second branch channel 322, so that the cross-sectional area of ​​the second main channel 321 is greater than the cross-sectional area of ​​the second branch channel 322. In other embodiments, the widths of the second main channel and the second branch channel can be the same, but the former has a greater depth than the latter; or, both the width and depth of the second main channel can be greater than the second branch channel, as long as the material conveying requirements are met, no specific limitations are imposed here.

[0062] To ensure that the molding material can smoothly turn and divert and uniformly converge in the second flow channel assembly 320, the second main flow channel 321 and the second diversion flow channel 322 are both non-linear flow channels, and the discharge ports of the four second diversion flow channels 322 are evenly spaced.

[0063] The second flow channel 322 includes a smoothly connected third straight section 3221 and a third curved section 3222. The third straight section 3221 connects to the second main flow channel 321, and the third curved section 3222 connects to the second mixing flow channel 323. The third curved section 3222 and the third straight section 3221 have a rounded transition, ensuring the smooth flow of the molding material in the flow channel. The angle between the third curved section 3222 and the third straight section 3221 is defined as the fourth curvature angle, which is 110°. The second flow channel 322 plays a role in smoothly diverting and turning the molding material, ultimately causing the four streams of molding material to converge evenly into the two second mixing flow channels 323.

[0064] Two secondary main channels 321 are spaced apart, and the inlet of the secondary main channel 321 corresponds to the position of the dispensing tube. The structure of the secondary main channel 321 is roughly the same as that of the primary main channel 311, and will not be described in detail here.

[0065] In this embodiment, the cross-sections of the second main channel 321 and the second branch channel 322 are both capsule-shaped. In other embodiments, the cross-sections of the second main channel and the second branch channel can be circular, trapezoidal, or rectangular, or they can be different, as long as they can meet the requirements for conveying the molding material. The bending angle of each channel can be adjusted according to the injection requirements and is not limited here.

[0066] Each second mixing channel 323 has two inlets at one end, and a total of four inlets in the two second mixing channels 323, which are respectively connected to the four second branch channels 322. The other end is connected to the mold cavity through the second glue inlet 302. The setting of the second mixing channels 323 allows the molding material to be mixed again after being diverted through the second main channel 321 and the second branch channels 322, which further homogenizes the molding material and ensures the uniform distribution of each component of the molding material. This avoids the problem of inconsistent local curing, which could lead to product defects in the high-voltage winding 130.

[0067] In this embodiment, the cross-sectional area of ​​the second mixing channel 323 gradually decreases along the injection advance direction, and its cross-sectional structure is basically the same as that of the first mixing channel 314. The second mixing channel 323 may only include the first mixing zone, and the cross-sectional area of ​​the first mixing zone gradually decreases; or it may include two, three or more mixing zones, with the cross-sectional area of ​​each mixing zone remaining unchanged along the injection advance direction, but the cross-sectional area of ​​multiple mixing zones gradually decreasing along the injection advance direction is sufficient to meet the injection requirements, which will not be elaborated here. The difference is that the width of the second mixing channel 323 is equal to the length of the second inlet 302, and the width of the second mixing channel 323 is much larger than the sum of the widths of the two second branch channels 322, and the capacity of the second mixing channel 323 is much larger than the sum of the capacities of the two second branch channels 322. This can effectively reduce the injection pressure when the molding material enters the cavity, prevent the molding material from impacting the high-voltage winding preform and causing it to shift, thus affecting product quality. At the same time, it can reduce the wear of the mold by the injection pressure and extend the mold life.

[0068] The two second runner components 320 adopt a symmetrical layout design to ensure that the molding material is evenly distributed to both sides when entering the second runner component 320, avoiding flow velocity differences caused by asymmetry of the runners. Specifically, the two second main runners 321 and the four second branch runners 322 are arranged in a mirror symmetrical manner to ensure that the flow direction and pressure distribution of the molding material in each runner are spatially symmetrical. At the same time, the four second branch runners 322 adopt a balanced arrangement strategy, that is, the outlet spacing of the four second branch runners 322 is approximately the same, so that the flow resistance of each branch runner reaches a dynamic balance, effectively suppressing eddies and pressure fluctuations, and ensuring injection molding quality.

[0069] During injection, firstly, after the high-voltage coil 1320 is wound, the high-voltage winding preform and core mold are placed into the cavity and fixedly connected to the injection mold 200 through locking devices and tooling connectors. Secondly, the molding material enters the runner assembly 300 and the injection mold 200 sequentially through the injection tube of the injection machine, that is, the molding material is injected into the cavity of the injection mold 200 through the first runner assembly 310 and the second runner assembly 320 until the molding material in the cavity meets the injection requirements. Specifically, the molding material first enters two first main runners 311 and is firstly split through four first branch runners 312, that is, the molding material is split from two streams into four streams; then it is split through eight third branch runners 313, that is, the molding material is split from four streams into eight streams; finally, the eight streams of molding material converge into the first mixing runner 314 to mix and flow into the cavity. Simultaneously, the molding material enters the second main flow channel 321 and is diverted through four second branch channels 322, meaning the molding material is divided from two streams into four. Finally, the four streams of molding material converge into two second mixing channels 323 to mix and flow into the mold cavity. During the injection process, the overflow port is manually monitored for any overflow of molding material. If overflow occurs, it indicates that the molding material in the mold cavity has reached a sufficient filling level, meeting the injection requirements, and injection can be stopped. Finally, the injection mold 200 is heated by a temperature control device. During heating, the actual temperature of the molding material is monitored and controlled in real time. If the actual temperature is lower than the set temperature, heating is performed; otherwise, heating is stopped, ensuring that the actual temperature of the molding material always meets the injection requirements. Ultimately, the molding material solidifies on the outer periphery of the high-voltage winding preform to form a high-voltage insulation layer 1330, thus forming the high-voltage winding 130.

[0070] The beneficial effects of this application are: the injection mold of this application can make the molding material enter the cavity evenly through the uniform distribution and buffer design of the flow channel, ensuring the uniformity and stability of the high voltage insulation layer molding, and can effectively reduce the impact force of the molding material on the inner wall of the mold and the high voltage winding preform when entering the cavity, ensuring the quality of the high voltage winding and extending the life of the injection mold.

[0071] Meanwhile, the first and second injection ports of the injection mold in this application are respectively located on the inner walls of the cavity on both sides of the horizontal axis. By injecting glue from both sides at the same time, the balance of the injection filling of the molding material can be ensured, further ensuring the molding quality of the high voltage insulation layer, while reducing the injection filling time and improving production efficiency.

[0072] Furthermore, the cavity of the injection mold in this application is set horizontally along the axis, which allows for the horizontal installation of the core mold. This facilitates maintaining the same core mold installation direction as the injection process, the earlier winding process, and the later demolding process during the production of high-voltage windings, thus enabling mass production.

[0073] The above description is merely an embodiment of this application and does not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. An injection mold for injecting a high voltage insulation layer around a high voltage winding preform to produce a high voltage winding, characterized in that, The injection mold includes an upper mold and a lower mold. The upper mold and the lower mold are joined to form a cavity and a runner assembly. The shape of the cavity matches the outer surface of the high-voltage winding and is used to place the high-voltage winding preform for injection. The inner wall of the cavity is provided with a sprue. The runner assembly is connected to the cavity through the sprue and is used to deliver molding material to the cavity. The runner assembly includes at least one main runner, at least two branch runners, and a mixing runner. The main runner, the branch runners, and the mixing runner are connected sequentially along the injection advance direction. The cross-sectional area of ​​the mixing runner gradually decreases along the injection advance direction.

2. The injection mold of claim 1, wherein, The mixing channel includes a first mixing zone, a second mixing zone, and a third mixing zone connected in sequence along the injection direction. The cross-sectional area of ​​the first mixing zone gradually decreases along the injection direction, while the cross-sectional areas of the second and third mixing zones remain unchanged along the injection direction. The cross-sectional area of ​​the second mixing zone is equal to the end cross-sectional area of ​​the first mixing zone and greater than the cross-sectional area of ​​the third mixing zone.

3. The injection mold of claim 1, wherein, The cavity is arranged horizontally along its axial direction.

4. The injection mold of claim 1, wherein, The inlet includes a first inlet and a second inlet, which are respectively disposed on the inner walls of the horizontal axis of the cavity; the flow channel assembly includes a first flow channel assembly and a second flow channel assembly, the first flow channel assembly is connected to the cavity through the first inlet, and the second flow channel assembly is connected to the cavity through the second inlet.

5. The injection mold of claim 4, wherein, The first flow channel assembly includes two first main flow channels, four first branch flow channels, eight third branch flow channels, and a first mixing flow channel. The outlet of each first main flow channel is simultaneously connected to the inlet of two first branch flow channels, the outlet of each first branch flow channel is simultaneously connected to the inlet of two third branch flow channels, and the outlets of the eight third branch flow channels are simultaneously connected to the eight inlets of the first mixing flow channel.

6. The injection mold of claim 5, wherein, The cross-sectional areas of the first main channel, the first branch channel, and the third branch channel decrease sequentially.

7. The injection mold of claim 5, wherein, The discharge ports of the eight third diversion channels are evenly spaced.

8. The injection mold of claim 4, wherein, The second flow channel assembly is provided in two parts. Each second flow channel assembly includes a second main flow channel, two second branch flow channels, and a second mixing flow channel. The outlet of the second main flow channel is simultaneously connected to the inlet of the two second branch flow channels, and the outlet of the two second branch flow channels is simultaneously connected to the inlet of the second mixing flow channel.

9. The injection mold of claim 8, wherein, The cross-sectional area of ​​the second main channel is larger than the cross-sectional area of ​​the second branch channel.

10. The injection mold of claim 1, wherein, The inner wall of the cavity is also provided with at least one overflow port, which is used to detect whether the molding material in the cavity meets the injection requirements.

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