A mobile phone plastic middle frame mold capable of reducing the weight of a front mold glue inlet

Abstract

The application relates to a mobile phone plastic middle frame mold, and particularly discloses a mobile phone plastic middle frame mold capable of reducing the weight of a glue inlet of a front mold, which comprises a front mold bottom plate, a heat flow plate arranged on the front mold bottom plate, a pipeline arranged on the heat flow plate and a front mold core arranged on the pipeline, a heat flow channel is arranged on the pipeline and used for conveying and heating injection materials, a shunt channel and a gate are arranged on the front mold core, one side of the front mold core is outwardly protruded to form a mold core, a mold cavity of a rear mold core is matched with the mold core to form an injection space, the gate is communicated with the shunt channel and the injection space, one end of the heat flow channel is communicated with the shunt channel, and the other end of the heat flow channel is communicated with a nozzle of an injection machine, and the heat flow plate provides heat for the injection materials in the heat flow channel; the aperture size of the end part of the heat flow channel close to the shunt channel continuously and gradually changes, the shunt channel has a plurality of shunt paths, the plurality of shunt paths are distributed around a central axis of the pipeline in a spoke structure from the communication part of the heat flow channel and the shunt channel, and the gate is communicated with the corresponding shunt path.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of mobile phone middle frame mold, and particularly discloses a mobile phone plastic middle frame mold capable of reducing the weight of the front mold glue inlet. BACKGROUND

[0002] In the production process of the mobile phone plastic middle frame, the traditional mold has many problems. For example, the hot runner design is unreasonable, which leads to poor flow of the injection material, excessive local pressure, and great pressure on the front mold glue inlet; the structure of the flow channel is single, which cannot uniformly distribute the injection material, so that the front mold glue inlet bears a heavy burden; the gate structure is not good, which cannot meet the conveying demand of different flow injection materials, and affects the stability of the front mold glue inlet; the hot flow plate lacks precise temperature control, which causes unstable flow parameters of the injection material, and increases the burden of the front mold glue inlet; the stripping insert and the front mold core are not tightly matched, the water inlet hook needle design is unreasonable, which easily causes abnormal material flow and increases the pressure of the front mold glue inlet; the front mold core groove design is unreasonable, and the front mold bottom plate has poor heat dissipation and unstable gate sleeve connection, which all affect the stability and efficiency of the injection molding process, so that the weight of the front mold glue inlet is large, which affects the service life of the mold and the product quality. SUMMARY

[0003] In order to overcome the shortcomings and deficiencies in the prior art, the purpose of the present application is to provide a mobile phone plastic middle frame mold capable of reducing the weight of the front mold glue inlet.

[0004] To achieve the above object, the mobile phone plastic middle frame mold for reducing the weight of the front mold glue inlet comprises a front mold bottom plate, a heat flow plate arranged on the front mold bottom plate, a pipe arranged on the heat flow plate, and a front mold core arranged on the pipe, the pipe is provided with a hot runner for conveying and heating the injection material, the front mold core is provided with a flow dividing channel and a gate, one side of the front mold core protrudes outward to form a mold core which cooperates with a mold cavity of a rear mold core to form an injection space, the gate is in communication with the flow dividing channel and the injection space, one end of the hot runner is in communication with the flow dividing channel, and the other end is in communication with a nozzle of an injection machine, and the heat flow plate provides heat for the injection material in the hot runner; the aperture size of the end portion of the hot runner near the flow dividing channel continuously changes, the flow dividing channel has a plurality of flow dividing paths, the plurality of flow dividing paths are distributed around the central axis of the pipe in a spoke structure from the communication position of the hot runner and the flow dividing channel, the gate is in communication with the corresponding flow dividing path, and the hot runner, the flow dividing channel and the gate jointly form a gating system; the pipe is arranged in a multi-layer pipe structure, the hot runner is arranged in the innermost layer of the multi-layer pipe structure, and a pore structure is arranged between the multi-layer pipe structures for heat preservation and heat insulation of the injection material in the hot runner, the hot runner has a first gentle portion, a first transition portion, a second gentle portion, a second transition portion, a third gentle portion and a third transition portion arranged and distributed in sequence along the length direction of the pipe, the gentle portions and the transition portions are arranged at intervals, the apertures of the flow holes where the first, second and third gentle portions are located are all constant in size, the apertures of the flow holes where the first and second transition portions are located are all uniformly changed from large to small, and the aperture of the flow hole where the third transition portion is located is uniformly changed from small to large, the aperture changes of the first and third transition portions are in a linear type, and the aperture change of the second transition portion is in an arc type.

[0005] The unique hot runner design, which continuously changes the aperture size of the end portion near the flow dividing channel, makes the injection material flow more smoothly in the process, reduces the flow resistance, and thus reduces the pressure requirement on the front mold glue inlet, and reduces the weight of the front mold glue inlet. The flow dividing channel has a plurality of flow dividing paths and is distributed in a spoke structure, which can uniformly distribute the injection material and avoid excessive local pressure, thereby reducing the burden of the front mold glue inlet and achieving the purpose of reducing the weight of the front mold glue inlet. The gating system composed of the hot runner, the flow dividing channel and the gate ensures the injection effect, optimizes the structure, reduces unnecessary material accumulation, and further reduces the weight of the front mold glue inlet.

[0006] The hot runner is arranged in the innermost layer of the multi-layer pipe structure, and the intermediate pore structure can effectively block the heat transfer to the outside. In the injection molding process, the hot runner needs to keep the injection material at a suitable melting temperature. Through this structural design, the heat loss is greatly reduced. The heat insulation effect of the pore structure helps to maintain the stability of the hot runner temperature. Because it can buffer the influence of external temperature changes on the hot runner, the temperature fluctuation of the injection material in the hot runner is reduced. Stable temperature is crucial for the quality of injection products, which can ensure the uniformity of the flowability of the injection material throughout the injection process, avoiding product defects caused by temperature fluctuations, such as surface flaws, internal bubbles or size deviation. The unique segmented structure of the hot runner includes a first gentle part, a first transition part, a second gentle part, a second transition part, a third gentle part, and a third transition part arranged in sequence. This design makes the flow of injection material in the hot runner more orderly and stable. The first transition part and the third transition part change in a straight line type aperture, and the second transition part changes in a circular arc type aperture. This diversified transition method can better control the flow rate and pressure of the injection material, reduce the impact on the front mold glue inlet, and thus reduce the weight of the front mold glue inlet. The gentle part and the transition part are arranged alternately, and the aperture size of the gentle part is constant, which ensures the stability during the injection process. The aperture change design of the transition part can adjust the flow state of the material according to the injection requirements at different stages, avoid excessive local pressure, and thus effectively reduce the weight of the front mold glue inlet.

[0007] Further, the shunt path has a first branch, a second branch and a third branch arranged in sequence and communicated on the front mold core, the first branch corresponds to the shunt path one by one, a plurality of first branches are coplanarly arranged, the second branch corresponds to the first branch one by one, the length direction of any second branch is perpendicular to the length direction of the corresponding first branch, the third branch is arranged around the central axis of the second branch, and the third branch is communicated with the gate; the communication place of any first branch and second branch and / or the communication place of any second branch and third branch are provided with a semicircular protruding part for slowing down the impact of the molten injection material on the flow channel.

[0008] The unique design of the runner system, comprising sequentially connected first, second, and third branches, allows the injection material to flow orderly towards the gate. The coplanar arrangement of multiple first branches and the perpendicular placement of the second branch to the first ensures the rationality and stability of material flow. The third branch, arranged around the gate and connected to it, further optimizes the injection path. This runner system design reduces material turbulence and pressure concentration during flow, thereby reducing pressure on the front mold gate and thus reducing its weight. Semi-circular protrusions at the junctions of the first and second branches and / or the second and third branches effectively mitigate the impact of molten injection material on the runner. This design reduces the impact force of material flow, minimizing the influence on the front mold gate and further reducing its weight.

[0009] Furthermore, the gate has a first inlet with an arc-shaped fan structure set on the mold core and a second inlet with a pin-point structure. The second inlet is formed by the end of part of the second branch. The first inlet is connected to the third branch and the two correspond one-to-one. The first inlet is used to convey a large flow of injection molding material, and the second inlet is used to convey a small flow of injection molding material.

[0010] The unique gate design includes a curved, fan-shaped first inlet and a pin-point type second inlet, enabling the delivery of different flow rates of injection molding material according to varying injection molding requirements. The first inlet is used to deliver large flow rates of material, ensuring injection efficiency; the second inlet is used to deliver small flow rates of material, improving injection precision. This rational gate design makes the injection process more stable, reduces pressure fluctuations on the front mold gate, and thus reduces the weight of the front mold gate. The second inlet is formed from the end of a portion of the second branch, working in conjunction with the branch flow structure to ensure smoother material flow. Simultaneously, this design avoids material accumulation and blockage at the gate, reducing the burden on the front mold gate and achieving the goal of reducing its weight.

[0011] Furthermore, the hot runner plate is equipped with a heavy-duty connector that connects to an external temperature control box. The temperature control box controls the heating parameters of the hot runner plate and adjusts the flow parameters of the injection molding material in the hot runner to ensure that the injection molding material flows smoothly in the hot runner.

[0012] A heavy-duty connector is installed on the hot runner plate to connect to an external temperature control chamber. The chamber precisely controls the heating parameters of the hot runner plate, thereby regulating the flow parameters of the injection molding material within the hot runner. This ensures smooth flow of the injection molding material within the hot runner, preventing excessive pressure on the front mold gate caused by unstable material flow, thus reducing the weight of the front mold gate. Precise temperature control and flow parameter adjustment improve injection molding quality and efficiency, while also reducing the risk of damage to the front mold gate due to abnormal material flow, extending the mold's lifespan.

[0013] Furthermore, the pipe is provided with a stripping insert, which is assembled and fitted with the front mold core. One side of the stripping insert protrudes outward to form a positioning boss that fits with the front mold core. A clearance step is formed between the positioning boss and the stripping insert. The boss surface of the positioning boss has a through hole along the thickness direction of the stripping insert to fit with the flow distribution path. The flow distribution path is L-shaped, and the through hole contains a sprue hook. One end of the sprue hook protrudes into the flow distribution path through the intersection of the L-shaped flow channel to form a hook shape, and the other end is detachably connected to the stripping insert.

[0014] A stripper insert is installed on the manifold, assembling with the front mold core to ensure the stability of the mold structure. A locating boss on one side of the stripper insert fits tightly with the front mold core, and the through-hole on the boss surface matches the runner, making the injection process more precise. The runner has an L-shaped design, which, together with the sprue hook, effectively controls the flow and demolding of the injection material. A clearance step is formed between the locating boss and the stripper insert, providing operating space when installing and removing the stripper insert. This makes the installation process more convenient, allowing for accurate assembly of the stripper insert with the front mold core. The clearance step prevents interference between the locating boss and other components during mold operation. This precise structural design reduces the uncertainty of material flow, lowers the pressure on the front mold sprue, and thus reduces the weight of the front mold sprue. One end of the sprue hook protrudes into the runner in a hook shape, while the other end is detachably connected to the stripper insert, facilitating mold maintenance and cleaning. At the same time, this design also helps to improve the efficiency and quality of injection molding, reduce the adverse effects of gate problems on the front mold gate, and achieve the goal of reducing the weight of the front mold gate.

[0015] Furthermore, cooling channels are provided on the stripping insert and the front mold core. The cooling channels are arranged in a grid pattern around the central axis of the pipes, and the layout of the cooling channels is matched with the size of the mold core.

[0016] The stripper insert and the front mold core feature a grid-like cooling channel layout that surrounds the central axis of the channels, effectively cooling the mold and improving injection efficiency. This layout, matched to the mold core dimensions, ensures more uniform cooling, preventing localized overheating or undercooling. Uniform cooling reduces internal stress caused by uneven temperature, thus minimizing the impact on the front mold gate and reducing its weight. A well-designed cooling channel layout also extends mold lifespan, reduces mold deformation caused by uneven thermal expansion and contraction, further ensuring the stability of the injection molding process and providing strong support for reducing the weight of the front mold gate.

[0017] Furthermore, a heating plate is provided on the hot runner plate, and a heater is embedded in the heating plate for heating the hot runner. The heater is electrically connected to the temperature control box for controlling the heating parameters of the heater. The side of the hot runner plate away from the hot runner is recessed inward to form a receiving groove for accommodating the heating plate. The receiving groove extends along the length and / or width of the hot runner plate to communicate with the outside to form a heat dissipation groove. The two sides of the side of the hot runner plate away from the hot runner are recessed inward along the length direction to form a stepped structure.

[0018] A heating plate and embedded heaters are installed on the hot runner plate to provide a stable heat source for the hot runner. The heaters are electrically connected to a temperature control box, allowing for precise control of heating parameters to ensure the injection molding material maintains suitable flowability within the hot runner. This precise temperature control reduces material flow instability and lowers the pressure on the front mold sprue, thereby reducing its weight. Recessed grooves on the hot runner plate accommodate the heating plate and extend along its length and / or width to form heat dissipation channels, effectively dissipating the heat generated by the heaters and preventing localized overheating. This excellent heat dissipation ensures uniform temperature in the hot runner, preventing uneven temperature from affecting material flow and further reducing the burden on the front mold sprue, thus achieving the goal of reducing its weight. Stepped structures are formed on both sides of the hot runner plate along its length away from the hot runner, increasing the structural stability of the hot runner plate and also contributing to uniform heat distribution and dissipation, further improving the mold's operational stability and providing a reliable guarantee for reducing the weight of the front mold sprue.

[0019] Furthermore, one side of the front mold core is recessed inward to form a first groove, and the side of the front mold core away from the first groove is recessed inward to form a second groove for cooperating with the rear mold core. The number of second grooves is set to be multiple, and the multiple second grooves are distributed around the mold core.

[0020] The front mold core has an inwardly recessed first groove on one side and multiple second grooves on the other side for mating with the rear mold core. This design optimizes the mold structure. Multiple second grooves are distributed around the mold core, making the fit between the front and rear mold cores tighter and more stable. This stable fit reduces pressure fluctuations during injection molding, thereby mitigating the impact on the front mold gate and reducing its weight. The well-designed grooves can also optimize the flow path of the injection molding material, preventing material accumulation and blockage within the mold, further reducing the burden on the front mold gate and contributing to its weight reduction.

[0021] Furthermore, a heat dissipation pad is installed on the side of the front mold base plate away from the hot runner plate, and a sprue sleeve is screwed on for communication with the nozzle of the injection molding machine. A positioning ring is installed on the heat dissipation pad for positioning connection with the nozzle of the injection molding machine, and the sprue sleeve is connected to the hot runner.

[0022] A heat dissipation pad is installed on the side of the front mold base plate opposite to the hot runner plate, which effectively dissipates the heat generated during injection molding, reduces the mold temperature, and extends the mold's service life. The screw-in sprue bushing connects to the injection molding machine nozzle, ensuring smooth material delivery. A locating ring is installed on the heat dissipation pad for positioning the nozzle, ensuring injection accuracy and stability. This rational structural design reduces the adverse effects of excessive temperature or unstable connection on the front mold sprue, thereby reducing its weight. The sprue bushing connects to the hot runner, allowing the injection material to flow quickly and evenly into the mold. Good connectivity reduces material resistance and pressure loss during flow, lowering the pressure requirements on the front mold sprue, thus achieving the goal of reducing its weight.

[0023] The beneficial effects of this invention are as follows: Through the unique aperture variation design of the hot runner, the spoke-shaped structure of the branch runner and the design of multiple branch paths, the special structure of the gate, the connection between the hot runner plate and the temperature control box to achieve precise temperature control, the fit between the stripper insert and the front mold core, the design of the gate hook, the groove design of the front mold core, the heat dissipation pad of the front mold base plate and the gate sleeve, etc., the injection material flows more smoothly and stably in the mold, reducing flow resistance, impact force and pressure fluctuation, avoiding material accumulation and blockage, while optimizing temperature control and mold structure stability, thereby effectively reducing the weight of the front mold gate, improving injection efficiency and quality, and extending the service life of the mold. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the first integral structure of a mobile phone plastic mid-frame mold for reducing the weight of the front mold glue inlet according to the present invention.

[0025] Figure 2 This is a schematic diagram of the second overall structure of the present invention;

[0026] Figure 3 This is a partial structural diagram of the present invention;

[0027] Figure 4 This is a partial exploded view of the structure of the present invention;

[0028] Figure 5 The diagram shows the structure of the pipe of this invention, along with its exploded view.

[0029] Figure 6 This is a cross-sectional view of the pipe structure of the present invention;

[0030] Figure 7 This is a cross-sectional view of the structure of the thermal nozzle of the present invention;

[0031] Figure 8 This is a partial structural diagram of the front mold core of the present invention;

[0032] Figure 9 This is a schematic diagram of the runner and gate structure of the present invention;

[0033] Figure 10 This is a schematic diagram of the structure of the heat flow plate of the present invention;

[0034] Figure 11 This is a partial structural schematic diagram of the heat flow plate of the present invention;

[0035] Figure 12 This is a schematic diagram of the structure of the stripping insert of the present invention.

[0036] The reference numerals in the attached drawings include: 1. Front mold base plate; 11. Sprue bushing; 2. Hot runner plate; 21. Heavy-duty connector; 22. Heating plate; 23. Heater; 24. Receiving groove; 25. Heat dissipation groove; 3. Pipe; 31. Hot runner; 311. First smooth section; 312. First transition section; 313. Second smooth section; 314. Second transition section; 315. Third smooth section; 316. Third transition section; 32. Outer tube; 33. First inner tube; 34. Second inner tube; 35. Hot nozzle; 36. Hot nozzle insert; 37. Insulating air gap layer; 4. Front mold core; 41. Runner; 411. Runner path; 4111. First branch path; 4112. Second branch path; 4113. Third branch path; 4114. Protrusion; 42. Gate; 421. First feed port; 422. Second feed port; 43. Mold core; 44. First groove; 45. Second groove; 5. Stripping insert; 51. Positioning boss; 52. Through hole; 53. Sprue hook; 54. Clearance step; 6. Cooling channel; 7. Heat dissipation pad; 71. Positioning ring. Detailed Implementation

[0037] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to embodiments and accompanying drawings. The content mentioned in the embodiments is not intended to limit the present invention.

[0038] Please see Figures 1 to 12 As shown, this invention provides a mobile phone plastic frame mold for reducing the weight of the front mold sprue. It includes a front mold base plate 1, a hot runner plate 2 mounted on the front mold base plate 1, a pipe 3 mounted on the hot runner plate 2, and a front mold core 4 mounted on the pipe 3. The pipe 3 has a hot runner 31 for conveying and heating the injection molding material. The front mold core 4 has a runner 41 and a gate 42. One side of the front mold core 4 protrudes outward to form a mold core 43, which cooperates with the mold cavity of the rear mold core to form an injection space. The gate 42 communicates with the runner 41 and the injection space. One end of the hot runner 31 is connected to the runner 41, and the other end is connected to the nozzle of the injection molding machine. The hot runner 2 provides heat to the injection material in the hot runner 31. The diameter of the orifice near the end of the hot runner 31 changes continuously. The runner 41 has multiple flow paths 411. The multiple flow paths 411 are distributed in a spoke-like structure around the central axis of the pipe 3 from the connection point of the hot runner 31 and the runner 41. The gate 42 is connected to the corresponding flow path 411. The hot runner 31, the runner 41 and the gate 42 together form the gating system. The pipe 3 is configured as a multi-layer pipe structure, and the hot runner 31 is located in the innermost layer of the multi-layer pipe structure. The multi-layer pipe structure is provided with a porous structure for heat insulation of the injection molding material in the hot runner 31. The hot runner 31 has a first smooth section 311, a first transition section 312, a second smooth section 313, a second transition section 314, a third smooth section 315, and a third transition section 316 arranged sequentially along the length of the pipe 3. The smooth sections and transition sections are arranged alternately. The orifice size of the first, second, and third smooth sections 315 remains unchanged. The orifice size of the first transition section 312 and the second transition section 314 decreases uniformly from large to small. The orifice size of the third transition section 316 increases uniformly from small to large. The orifice size changes of the first transition section 312 and the third transition section 316 are linear, while the orifice size change of the second transition section 314 is arc-shaped.

[0039] In practical use, the front mold base plate 1 can be made of high-strength steel to provide stable support. The hot runner plate 2 is fixed to the front mold base plate 1 with bolts to ensure a firm connection. The pipe 3 can be made of metal with good thermal conductivity. The front mold core 4 is precisely installed on the pipe 3 to ensure accurate positioning. The hot runner 31 is used for conveying and heating the injection molding material. Its internal structure is rationally designed to efficiently convey the injection molding material to the runner 41 and the gate 42. The design of the runner 41 and the gate 42 allows the injection molding material to flow evenly into the injection space, ensuring the quality of the mobile phone plastic frame. The hot runner plate 2 provides heat to the injection molding material in the hot runner 31, ensuring that the injection molding material flows at a suitable temperature.

[0040] In practical use, the hot runner 31 is located in the innermost layer of the multi-layer tube structure, and the porous structure in the middle effectively blocks heat transfer to the outside. During injection molding, the hot runner 31 needs to maintain the injection material at a suitable melting temperature. This structural design greatly reduces heat loss. The insulating effect of the porous structure helps maintain the temperature stability of the hot runner 31. Because it buffers the impact of external temperature changes on the hot runner 31, it reduces temperature fluctuations of the injection material within the hot runner 31. Stable temperature is crucial for the quality of injection molded products. It ensures uniform flow of the injection material throughout the injection molding process and avoids product defects caused by temperature fluctuations, such as surface blemishes, internal bubbles, or dimensional deviations.

[0041] In actual use, firstly, the nozzle of the injection molding machine is connected to the hot runner 31, and molten plastic material is injected into the hot runner 31. After entering the first smooth section 311, the material can quickly flow into the hot runner 31 due to the large orifice diameter. As the material passes through the first transition section 312, the orifice diameter gradually decreases, and the material flow rate gradually decreases, avoiding jetting and turbulence that may be caused by excessively fast flow rates. Next, the material enters the second smooth section 313, where the flow rate remains relatively stable. In the second transition section 314, the arc-shaped orifice diameter change further smooths and adjusts the material flow rate, ensuring a more stable material flow. Then, the material enters the third smooth section 315, providing a stable foundation for subsequent flow. Finally, through the third transition section 316, the orifice diameter uniformly increases from small to large, smoothly pushing the material into the branch channel 41.

[0042] In this embodiment, the pipe 3 has an outer pipe 32, a first inner pipe 33, a second inner pipe 34, a hot nozzle 35, and a hot nozzle insert 36. The hot runner 31 is disposed inside the first inner pipe 33 and is connected to the hot runner plate 2 and the hot nozzle 35 respectively. The second inner pipe 34 is assembled outside the first inner pipe 33, and the outer pipe 32 is assembled outside the second inner pipe 34. The hot nozzle 35 is assembled between the first inner pipe 33 and the second inner pipe 34 and is connected to the flow channel 41. A heat insulation air gap layer 37 is provided between the first inner pipe 33 and the second inner pipe 34 and between the second inner pipe 34 and the outer pipe 32 for heat insulation of the injection molding material. The hot nozzle insert 36 is sleeved on the end of the second inner pipe 34 near the flow channel 41. The outer pipe 32, the stripper insert 5, and the front mold core 4 jointly abut against the hot nozzle insert 36 to restrict the freedom of the hot nozzle insert 36 in any direction.

[0043] In actual use, air gaps are provided between the first inner tube 33 and the second inner tube 34, and between the second inner tube 34 and the outer tube 32, for heat insulation. These air gaps utilize the low thermal conductivity of air to effectively reduce heat transfer, ensuring the temperature stability of the material within the hot runner 31 and reducing the thermal impact on other parts of the mold, thus improving the overall performance and service life of the mold. The hot nozzle insert 36 is fitted onto the end of the second inner tube 34 near the runner 41, and its freedom of movement is restricted by the combined contact of the outer tube 32, the stripper insert 5, and the front mold core 4. The hot nozzle insert 36 not only provides better positioning and protection for the hot nozzle 35, but also ensures the stability of the hot nozzle insert 36 during the injection molding process through the coordinated contact of multiple components, thereby guaranteeing the precision and quality of injection molding. This design solves the problem of hot nozzle displacement and instability in the mold. The multi-layer pipe structure 3 and the air gap design help to precisely control the temperature and flow state of the injection molding material. Stable temperature ensures material flowability and performance consistency, reducing product defects such as bubbles and warping caused by temperature variations. Simultaneously, precise control of material flow allows for more uniform filling, improving dimensional accuracy and appearance quality. The multi-layered structure of pipe 3 and the rational assembly of components facilitate mold maintenance and repair. For example, if a problem occurs with hot runner 31 or hot nozzle 35, this design allows for easier disassembly and replacement of the relevant components, reducing maintenance time and costs.

[0044] Specifically, the flow distribution path 411 has a first branch 4111, a second branch 4112, and a third branch 4113 that are sequentially connected on the front mold core 4. The first branch 4111 corresponds to the flow distribution path 411 one by one, and multiple first branches 4111 are arranged in the same plane. The second branch 4112 corresponds to the first branch 4111 one by one, and the length direction of any second branch 4112 is perpendicular to the length direction of the corresponding first branch 4111. The third branch 4113 is distributed around the central axis of the second branch 4112 and is connected to the gate 42. The connection between any first branch 4111 and the second branch 4112 and / or the connection between any second branch 4112 and the third branch 4113 is provided with a semi-circular protrusion 4114 for slowing down the impact of molten injection material on the flow channel.

[0045] In actual use, when the injection molding machine injects molten injection material into the hot runner 31 through the nozzle, the material first enters the first smooth section 311 of the hot runner 31. As the material flows, it passes through the first transition section 312, where the orifice diameter gradually decreases and the material flow rate increases. Then it enters the second smooth section 313, where the flow rate remains stable. Next, it passes through the second transition section 314, where the arc-shaped orifice diameter change adjusts the material flow rate again. Then it enters the third smooth section 315 and the third transition section 316, where the orifice diameter uniformly increases from small to large, smoothly conveying the material to the branch runner 41. In the branch runner 41, the material enters the first branch 4111 from the hot runner 31. Since multiple first branches 4111 are coplanar, the material can be quickly and initially distributed in the same plane. Then the material flows into the second branch 4112. Since the second branch 4112 is perpendicular to the first branch 4111, the flow direction of the material changes. During this process, the semi-circular protrusion 4114 acts to mitigate impact and reduce material damage to the flow channel. Finally, the material enters the third branch 4113, which, through its surrounding arrangement, evenly delivers the material to the gate 42, into the injection molding space, completing the injection molding of the mobile phone's plastic frame.

[0046] Specifically, the gate 42 has a first inlet 421 with an arc-shaped fan structure disposed on the mold core 43 and a second inlet 422 with a pin-point structure. The second inlet 422 is formed by the end of part of the second branch 4112. The first inlet 421 is connected to the third branch 4113 and the two correspond one to one. The first inlet 421 is used to convey a large flow of injection molding material, and the second inlet 422 is used to convey a small flow of injection molding material.

[0047] In actual use, when the injection molding machine starts working, the molten injection material first enters the hot runner 31. After being adjusted by the various smooth sections and transition sections of the hot runner 31, it flows into the branch runner 41. In the branch runner 41, the material is conveyed through the first branch 4111, the second branch 4112, and the third branch 4113, reaching the gate 42. At this time, a large flow of injection material quickly enters the main part of the injection space through the arc-shaped fan-shaped inlet 421, rapidly filling the main body of the mobile phone plastic frame. At the same time, a small flow of injection material flows precisely to some detailed parts or areas that are difficult to fill, such as corners and small holes, through the needle-point structure of the second inlet 422. With this gate 42 design, the produced mobile phone plastic frame has a smooth surface, high dimensional accuracy, uniform filling in all parts, and no obvious defects.

[0048] Specifically, the hot runner plate 2 is equipped with a heavy-duty connector 21 that connects to an external temperature control box. The temperature control box controls the heating parameters of the hot runner plate 2 and adjusts the flow parameters of the injection molding material in the hot runner channel 31 so that the injection molding material flows smoothly in the hot runner channel 31.

[0049] In practical use, for a specific plastic material, the temperature control chamber maintains the temperature of the hot runner 2 within a specific range. At this temperature, the injection molding material maintains good fluidity within the hot runner 31. When the injection molding material enters the hot runner 31 from the injection molding machine nozzle, the heating effect of the hot runner 2 keeps the material at a suitable temperature, preventing solidification or decreased fluidity due to temperature drop during flow. Simultaneously, the temperature control chamber can adjust the heating parameters in real time according to the actual production process. If the material flow rate is found to be too fast or too slow, the fluidity of the material can be altered by adjusting the temperature of the hot runner 2, thus making the injection molding process smoother. In actual production, this precise temperature control results in mobile phone plastic frames with stable quality, high dimensional accuracy, and a smooth, defect-free surface.

[0050] Specifically, the pipe 3 is provided with a stripping insert 5, which is assembled and fitted with the front mold core 4. One side of the stripping insert 5 protrudes outward to form a positioning boss 51 that fits with the front mold core 4. A clearance step 54 is formed between the positioning boss 51 and the stripping insert 5. The boss surface of the positioning boss 51 is provided with a through hole 52 along the thickness direction of the stripping insert 5, which fits with the flow distribution channel 411. The flow distribution channel 411 is L-shaped. The through hole 52 contains a sprue hook 53. One end of the sprue hook 53 protrudes into the flow distribution channel 41 through the intersection of the L-shaped flow channel to form a hook shape, and the other end is detachably connected to the stripping insert 5.

[0051] In actual use, during the production of mobile phone plastic frames, after the injection molding machine injects molten injection material into the hot runner 31 of the mold, the material enters the L-shaped flow path 411 through the runner 41. The stripper insert 5 fits tightly with the front mold core 4, ensuring that the material can accurately fill the injection space. After injection molding is completed, the mold opens, and the stripper insert 5 begins to function. The hook-shaped end of the sprue hook 53 pulls the waste material in the runner, and as the mold opens, the waste material is separated from the product. Since the sprue hook 53 and the stripper insert 5 are detachably connected, the sprue hook 53 can be easily replaced when it is worn or damaged. Through this design of the stripper insert 5 and the sprue hook 53, automatic separation of waste material is successfully achieved, greatly improving production efficiency. At the same time, the surface quality and dimensional accuracy of the product are also effectively guaranteed, reducing the scrap rate and lowering production costs.

[0052] Specifically, cooling channels 6 are provided on the stripping insert 5 and the front mold core 4. The cooling channels 6 are arranged in a grid pattern around the central axis of the pipe 3. The layout of the cooling channels 6 is matched with the size of the mold core 43.

[0053] In actual use, the stripper insert 5 and the front mold core 4 are equipped with cooling channels 6 arranged in a grid pattern, which can provide all-around cooling of the injection-molded product around the central axis of the pipes 3. This layout increases the contact area between the cooling channels 6 and the mold, improves cooling efficiency, and allows the injection-molded product to cool and solidify quickly, shortening the production cycle. The grid pattern ensures uniform cooling. During the cooling process, all parts of the product can receive relatively consistent cooling simultaneously, avoiding problems such as product deformation and dimensional deviations caused by uneven cooling. This helps to improve product quality and dimensional accuracy.

[0054] Specifically, the heat flow plate 2 is provided with a heating plate 22, and a heater 23 is embedded in the heating plate 22 for heating the heat flow channel 31. The heater 23 is electrically connected to the temperature control box for controlling the heating parameters of the heater 23. The side of the heat flow plate 2 away from the heat flow channel 31 is recessed inward to form a receiving groove 24 for receiving the heating plate 22. The receiving groove 24 extends along the length and / or width of the heat flow plate 2 to communicate with the outside to form a heat dissipation groove 25. The two sides of the side of the heat flow plate 2 away from the heat flow channel 31 are recessed inward to form a stepped structure.

[0055] In practical use, during the production of mobile phone plastic mid-frames, heater 23 heats the hot runner 31 under the control of a temperature control box. When heater 23 is working, the heat generated is transferred to the injection molding material in the hot runner 31 through heating plate 22. Simultaneously, the design of the receiving groove 24 and heat dissipation groove 25 allows excess heat generated by heater 23 to dissipate in a timely manner. For example, during continuous production, heater 23 operates continuously, and heat dissipation groove 25 effectively dissipates heat into the surrounding environment, maintaining a stable temperature for the hot runner 2. The stepped structure provides better support for the hot runner 2, ensuring that it does not deform or shift during injection molding. This design of the hot runner 2 results in mobile phone plastic mid-frames with stable quality and high dimensional accuracy. At the same time, the service life of the mold is effectively extended, reducing production costs and maintenance frequency.

[0056] Specifically, one side of the front mold core 4 is recessed inward to form a first groove 44, and the side of the front mold core 4 away from the first groove 44 is recessed inward to form a second groove 45 for cooperating with the rear mold core. The number of second grooves 45 is set to be multiple, and the multiple second grooves 45 are distributed around the mold core 43.

[0057] In practical use, when producing plastic mid-frames for mobile phones, the first groove 44 of the front mold core 4 can be used to install auxiliary components, such as locating pins or sensors, as needed. Multiple second grooves 45 precisely match the corresponding structures of the rear mold core, ensuring the stability of the mold in the closed state. For example, for a specific model of mobile phone plastic mid-frame, four second grooves 45 are designed, evenly distributed around the mold core 43. During injection molding, the cooperation of these grooves with the rear mold core allows the injection material to accurately fill the injection space, resulting in mid-frames with higher dimensional accuracy and a smooth, burr-free surface. Simultaneously, due to the high precision of the mold fit, the scrap rate during production is reduced, improving production efficiency and economic benefits.

[0058] Specifically, a heat dissipation pad 7 is installed on the side of the front mold base plate 1 away from the hot runner plate 2, and a sprue sleeve 11 is screwed on for communication with the nozzle of the injection molding machine. A positioning ring 71 is installed on the heat dissipation pad 7 for positioning connection with the nozzle of the injection molding machine. The sprue sleeve 11 is connected to the hot runner 31.

[0059] In actual use, when the injection molding machine starts working, the nozzle of the injection molding machine accurately aligns with the sprue bushing 11 on the front mold base plate 1 via the positioning ring 71. The heat dissipation pad 7 effectively dissipates the heat generated by the mold, ensuring that the mold temperature is within a reasonable range. During continuous production, the heat dissipation pad 7 can continuously dissipate heat to prevent the mold from overheating. The positioning ring 71 ensures precise connection between the nozzle and the sprue bushing 11 with each injection, allowing the injection material to flow stably into the hot runner 31. If the sprue bushing 11 becomes worn, it can be quickly removed and replaced without affecting the production schedule. Through this design, the production process of the mobile phone plastic frame is more stable and efficient, and mold maintenance is also more convenient and quick.

[0060] The above description is only a preferred embodiment of the present invention. For those skilled in the art, there will be changes in the specific implementation and application scope based on the ideas of the present invention. The content of this specification should not be construed as a limitation of the present invention.

Claims

1. A mobile phone plastic mid-frame mold that reduces the weight of the front mold sprue, characterized in that: The mold includes a front mold base plate (1), a hot runner plate (2) mounted on the front mold base plate (1), a pipe (3) mounted on the hot runner plate (2), and a front mold core (4) mounted on the pipe (3). The pipe (3) is provided with a hot runner (31) for conveying and heating the injection molding material. The front mold core (4) is provided with a runner (41) and a gate (42). One side of the front mold core (4) protrudes outward to form a mold core (43) which cooperates with the mold cavity of the rear mold core to form an injection space. The gate (42) is connected to the runner (41) and the injection space. One end of the hot runner (31) is connected to the runner (41). The other end is connected to the nozzle of the injection molding machine. The hot runner (2) provides heat to the injection material in the hot runner (31). The diameter of the hole in the hot runner (31) near the end of the branch channel (41) changes continuously. The branch channel (41) has multiple branch paths (411). The multiple branch paths (411) are distributed around the central axis of the pipe (3) in a spoke-like structure from the connection of the hot runner (31) and the branch channel (41). The gate (42) is connected to the corresponding branch path (411). The hot runner (31), the branch channel (41) and the gate (42) together form the gating system. The pipe (3) is configured as a multi-layer pipe structure, and the hot runner (31) is located in the innermost layer of the multi-layer pipe structure. The multi-layer pipe structure is provided with a porous structure for heat insulation of the injection molding material in the hot runner (31). The hot runner (31) has a first smooth section (311), a first transition section (312), a second smooth section (313), a second transition section (314), a third smooth section (315), and a third transition section (316) arranged sequentially along the length of the pipe (3). The smooth sections and transition sections are arranged alternately. The orifice size of the first, second, and third smooth sections (315) remains unchanged. The orifice size of the first transition section (312) and the second transition section (314) decreases uniformly from large to small. The orifice size of the third transition section (316) increases uniformly from small to large. The orifice size changes of the first transition section (312) and the third transition section (316) are linear. The orifice size change of the second transition section (314) is arc-shaped.

2. A mobile phone plastic frame mold for reducing the weight of the front mold sprue as described in claim 1, characterized in that: The branch path (411) has a first branch (4111), a second branch (4112), and a third branch (4113) connected sequentially on the front mold core (4). The first branch (4111) corresponds one-to-one with the branch path (4111), and multiple first branches (4111) are arranged coplanarly. The second branch (4112) corresponds one-to-one with the first branch (4111), and the length direction of any second branch (4112) is parallel to the corresponding first branch (4111). The length direction of 111) is perpendicular to that of the second branch (4112). The third branch (4113) is distributed around the central axis of the second branch (4112). The third branch (4113) is connected to the gate (42). A semi-circular protrusion (4114) is provided at the connection between any first branch (4111) and the second branch (4112) and / or at the connection between any second branch (4112) and the third branch (4113) to slow down the impact of molten injection material on the flow channel.

3. A mobile phone plastic frame mold for reducing the weight of the front mold sprue as described in claim 2, characterized in that: The gate (42) has a first inlet (421) with an arc-shaped fan structure on the mold core (43) and a second inlet (422) with a pin-point structure. The second inlet (422) is formed by the end of part of the second branch (4112). The first inlet (421) is connected to the third branch (4113) and the two correspond one to one. The first inlet (421) is used to convey a large flow of injection molding material, and the second inlet (422) is used to convey a small flow of injection molding material.

4. A mobile phone plastic frame mold for reducing the weight of the front mold sprue as described in claim 1, characterized in that: The hot runner (2) is equipped with a heavy-duty connector (21) that connects to an external temperature control box. The temperature control box controls the heating parameters of the hot runner (2) and adjusts the flow parameters of the injection material in the hot runner (31) so that the injection material flows smoothly in the hot runner (31).

5. A mobile phone plastic frame mold for reducing the weight of the front mold sprue as described in claim 1, characterized in that: The pipe (3) is provided with a stripping insert (5), which is assembled with the front mold core (4). One side of the stripping insert (5) protrudes outward to form a positioning boss (51) that cooperates with the front mold core (4). A clearance step (54) is formed between the positioning boss (51) and the stripping insert (5). The boss surface of the positioning boss (51) is provided with a through hole (52) along the thickness direction of the stripping insert (5) to cooperate with the flow distribution path (411). The flow distribution path (411) is L-shaped. The through hole (52) contains a sprue hook (53). One end of the sprue hook (53) protrudes through the intersection of the L-shaped flow channel into the flow distribution channel (41) to form a hook shape. The other end is detachably connected to the stripping insert (5).

6. A mobile phone plastic frame mold for reducing the weight of the front mold sprue as described in claim 5, characterized in that: Cooling channels (6) are provided on the stripping insert (5) and the front mold core (4). The cooling channels (6) are arranged in a grid pattern around the central axis of the pipe (3). The layout of the cooling channels (6) matches the size of the mold core (43).

7. A mobile phone plastic frame mold for reducing the weight of the front mold sprue as described in claim 1, characterized in that: A heating plate (22) is provided on the heat flow plate (2), and a heater (23) is embedded on the heating plate (22) for heating the heat flow channel (31). The heater (23) is electrically connected to the temperature control box for controlling the heating parameters of the heater (23). The side of the heat flow plate (2) away from the heat flow channel (31) is recessed inward to form a receiving groove (24) for receiving the heating plate (22). The receiving groove (24) extends along the length and / or width of the heat flow plate (2) to communicate with the outside to form a heat dissipation groove (25). The two sides of the side of the heat flow plate (2) away from the heat flow channel (31) are recessed inward to form a stepped structure.

8. A mobile phone plastic frame mold for reducing the weight of the front mold sprue as described in claim 1, characterized in that: The front mold core (4) is recessed inward on one side to form a first groove (44), and the front mold core (4) is recessed inward on the side away from the first groove (44) to form a second groove (45) for cooperating with the rear mold core. The number of second grooves (45) is set to multiple, and multiple second grooves (45) are distributed around the mold core (43).

9. A mobile phone plastic frame mold for reducing the weight of the front mold sprue as described in claim 1, characterized in that: A heat dissipation pad (7) is installed on the side of the front mold base plate (1) away from the hot runner plate (2), and a sprue sleeve (11) is screwed on to connect with the nozzle of the injection molding machine. A positioning ring (71) is installed on the heat dissipation pad (7) to connect with the nozzle of the injection molding machine. The sprue sleeve (11) is connected with the hot runner (31).

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