Injection molding apparatus and method for refrigerator pet transparency

Abstract

The application discloses a refrigerator PET transparent part injection molding equipment and a method thereof, and relates to the technical field of injection molding equipment.The injection molding equipment comprises an injection molding machine body, a mold closing unit and a glue injection unit are arranged on the injection molding machine body, an injection anti-overflow plugging mechanism and an air duct intermittent plugging mechanism are arranged on the mold closing unit and the glue injection unit, the injection anti-overflow plugging mechanism further comprises an injection port anti-overflow assembly and a discharge plugging assembly, the injection port anti-overflow assembly and the discharge plugging assembly can compensate for equipment assembly gaps, realize seamless sealing of an injection channel, avoid melt overflow problems in the injection molding process, improve raw material utilization, the magnetic linkage of the air duct intermittent plugging mechanism can realize segmented control effects of plugging the air duct in the glue injection pressure maintaining stage and opening the air duct in the cooling stage, avoid cold spots, wrinkles and blockage at the end of the glue injection unit caused by the early cooling of the melt, and realize uniform air cooling and shaping of the plastic part.

Description

Technical Field

[0001] This invention relates to the field of injection molding equipment technology, specifically to an injection molding equipment and method for a refrigerator PET transparent part. Background Technology

[0002] In recent years, in order to achieve the goals of environmental protection and sustainable development, some plastics have been recycled and reused. Among them, PET material, with its advantages of good light transmittance, high strength, aging resistance and transparent texture, has been widely used in the processing and production of transparent plastic parts such as refrigerator decorative strips, transparent covers and storage boxes. These transparent refrigerator parts have extremely high requirements for molding flatness, light transmittance uniformity and appearance smoothness. Tiny bubbles, flow marks, cold spots, warping deformation and flash defects can all lead to product scrap.

[0003] The existing Chinese patent publication number is CN224527809U, and the patent name is a high-precision plastic shell molding device. It has the advantage that the demolded product falls through the inclined feeding plate and is discharged from the groove onto the external collection trolley.

[0004] However, in existing injection molding equipment, molten PET easily overflows from the injection port seam during high-pressure injection, causing material waste, increased production costs, and flash that damages the appearance of transparent parts, resulting in uneven thickness. Furthermore, conventional injection molding equipment often leaves molten material at the barrel outlet after injection, which can easily cool and harden, causing blockages. Dripping and stringing residues adhere to the surface of the plastic parts, creating defects and significantly reducing product yield. In addition, in existing injection molds, cold air from outside blows through the mold cavity to the injection unit during injection and holding pressure stages, causing premature cooling and hardening of the molten material at its ends, leading to premature hardening and even blockages at the outlet. Based on these shortcomings of the existing technology, this invention proposes an injection molding equipment and method for refrigerator PET transparent parts to solve these problems. Summary of the Invention

[0005] This invention provides an injection molding equipment and method for PET transparent parts for refrigerators, which can effectively solve the problems mentioned in the background art, such as the easy overflow of molten PET from the injection port joint gap, the easy residue of molten material at the barrel outlet after injection, the easy cooling and hardening of the residual material to form a blockage, and the problem that external cold air can blow through the mold cavity to the injection unit, causing the molten material at its end to cool and harden prematurely.

[0006] To achieve the above objectives, the present invention provides the following technical solution: an injection molding equipment for PET transparent parts of refrigerators, comprising an injection molding machine body, wherein the injection molding machine body is provided with a mold closing unit and an injection unit, wherein the mold closing unit and the injection unit are provided with an injection anti-overflow sealing mechanism and an intermittent air duct sealing mechanism, wherein the injection anti-overflow sealing mechanism further includes an injection port anti-overflow component and a discharge sealing component; The injection port anti-overflow component includes a through port, an inner conical guide block coaxially disposed in the middle of the through port, an inner conical surface disposed on the inner conical guide block, a sliding contact surface disposed on the inner conical guide block, and a tightly elastic element sleeved on the outer surface of the sliding contact surface; The discharge sealing assembly includes a sealing rod, on which a cylinder sealing block is provided, and on the injection unit on one side of the cylinder sealing block, a cylinder sealing inclined surface is provided; The intermittent duct sealing mechanism includes a vertical connecting duct and a horizontal connecting duct, which are interconnected. The horizontal connecting duct is symmetrically provided with a forward duct sealing slope and a reverse duct sealing slope. The intermittent duct sealing mechanism also includes an orifice groove interconnected with the horizontal connecting duct. An orifice connecting frame is provided in the orifice groove. A synchronization column is provided on the orifice connecting frame. A forward duct sealing block and a reverse duct sealing block are provided on the synchronization column.

[0007] In a preferred embodiment, the mold clamping unit includes four Green Columns disposed on the injection molding machine body. A movable template is slidably disposed on the Green Columns. A fixed template is fixedly disposed on one side of the movable template on the injection molding machine body. A toggle connecting rod is symmetrically disposed on one side of the fixed template. An ejector rod is disposed between the toggle connecting rods at the middle of the movable template.

[0008] In a preferred embodiment, the injection unit includes an injection stage mounted on the injection molding machine body. The injection stage is equipped with a heating module, and the heating module contains a receiving cylinder. The receiving cylinder contains a feeding screw, and a hopper is connected to the receiving cylinder.

[0009] In a preferred embodiment, the injection port anti-overflow component of the injection anti-overflow sealing mechanism further includes a feed restricting ring fixedly disposed at the through-hole. The through-hole is opened on the fixed template, and a feed inlet is provided through the middle of the feed restricting ring. A fixed abutment plane is provided on the side of the feed restricting ring near the inner conical guide block.

[0010] In a preferred embodiment, the sliding contact surface of the inner conical guide block slides on the inner wall of the feed limiting ring. The inner conical guide block is provided with a horizontal extrusion surface. A spring movable cavity is provided between the horizontal extrusion surface and the feed limiting ring. A tight elastic element on one side of the horizontal extrusion surface is located in the spring movable cavity. The inner conical guide block is provided with a movable abutment plane. The movable abutment plane and the fixed abutment plane are in contact with each other when the injection unit extrudes.

[0011] In a preferred embodiment, the discharge sealing component of the injection anti-overflow sealing mechanism further includes a cylinder expansion cavity disposed on the receiving cylinder. The cavity wall of the cylinder expansion cavity is connected to the cylinder sealing inclined surface. The end of the feeding screw in the receiving cylinder is fixedly connected to the sealing rod. A tapered discharge port is provided on the side of the receiving cylinder near the inner conical guide block. The tapered discharge port has the same slope as the inner conical surface of the inner conical guide block.

[0012] In a preferred embodiment, the intermittent duct sealing mechanism further includes a coaxial movable cavity coaxially arranged with the through-hole. A magnetic ring is provided on the inner wall of the coaxial movable cavity, and a telescopic spring is provided on the side wall of the magnetic ring within the coaxial movable cavity. A magnetic column is provided on one side of the magnetic ring on the material cylinder sealing block. The magnetic ring and the magnetic column are initially arranged in a spaced-out repulsive manner.

[0013] In a preferred embodiment, the intermittent duct sealing mechanism further includes vertical grooves symmetrically and interconnectedly arranged in the middle of the orifice groove. Both the orifice groove and the vertical groove are arranged on a fixed template. A connecting strip is provided on the groove wall of the vertical groove. One end of the connecting strip is connected to a magnetic ring, and the other end is connected to an orifice connecting frame. The orifice connecting frame and the connecting strip slide together on the groove walls of the orifice groove and the vertical groove.

[0014] In a preferred embodiment, the synchronizing column on the mouth-shaped connecting frame is located inside the horizontal connecting ventilation duct. Both the horizontal and vertical connecting ventilation ducts are located on the fixed template. The forward air duct blocking block on the synchronizing column is used to block the forward air duct blocking slope, and the reverse air duct blocking block on the synchronizing column is used to block the reverse air duct blocking slope.

[0015] A method for using an injection molding equipment for a refrigerator PET transparent part, applied to the aforementioned injection molding equipment for a refrigerator PET transparent part, includes the following steps: S1: First, the injection unit is filled with and melted PET raw material. The injection unit is driven to move and align and fit with the mold closing unit. The mold closing unit begins to close the mold. After the mold closing is completed, the injection unit injects molten PET material into the mold closing unit. S2: During the process of the injection unit fitting to the mold closing unit, the inner conical guide block in the injection port anti-overflow component fits tightly against the material outlet of the injection unit under the action of the tight elastic element, preventing PET melt from overflowing from the gap during injection. S3: When the injection unit is injecting, the barrel sealing block on the sealing rod of the discharge sealing component, together with the barrel sealing ramp, releases the seal of the injection unit from the molten material, allowing the molten material to smoothly enter the mold closing unit. After the injection unit completes one injection, the barrel sealing block on the sealing rod, together with the barrel sealing ramp, seals the injection unit and pulls back part of the molten material to avoid material leakage. S4: When the discharge sealing component is running, the intermittent air duct sealing mechanism will block the horizontal connecting air duct to prevent the material from cooling prematurely during the injection process and to prevent the material from entering the air duct and forming burrs. When the discharge sealing component retracts in the injection unit, it opens the horizontal connecting air duct to connect with the vertical connecting air duct to quickly cool the transparent part. S5: After the PET transparent part has completely cooled and solidified, release the mold locking state, take out the molded refrigerator PET transparent part, and complete the single molding operation. After cleaning the mold cavity debris, repeat the above steps S3 to S5 to carry out continuous batch injection molding production.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention, by setting up an injection anti-overflow sealing mechanism, combined with an adaptive sealing and guiding structure consisting of an inner conical guide block, a tightly elastic component, and a feed restriction ring, addresses the gap sealing and melt flow stabilization design throughout the injection molding process. This achieves the effect of sealing injection gaps and preventing PET melt overflow and leakage, while effectively suppressing melt turbulence and flow disturbances, preventing bubbles and flow marks inside transparent parts, significantly improving the smoothness and light transmittance of molded parts, reducing overflow waste, increasing raw material utilization, and lowering production costs. This invention achieves the effect of automatically releasing the outlet blockage during injection molding and quickly sealing the barrel outlet channel after holding pressure by setting a synchronous linkage structure between the feeding screw and the sealing rod in the outlet sealing component of the injection unit. Starting from the integrated mechanical linkage design of injection molding propulsion and pressure holding reset, it also recovers the trace residual material at the outlet by the small retraction action of the feeding screw, solving the problems of residual material dripping, stringing, and accumulation at the outlet, avoiding appearance defects caused by residual material adhering to the plastic part, and effectively avoiding the blockage caused by the cooling and hardening of residual material at the barrel outlet, thus ensuring the continuous and stable operation of the injection molding process. This invention, by setting up an intermittent air duct sealing mechanism, utilizes a non-powered linkage structure with magnetic repulsion and telescopic spring reset. Starting from the intermittent air duct control design of sealing the air duct during the injection stage and opening the air duct during the cooling stage, it achieves the effect of blocking cold air from entering the mold cavity throughout the injection and holding pressure process, keeping the cavity in a sealed and constant temperature state, avoiding premature cooling of the PET melt, and completely avoiding molding defects such as cold spots, burrs, and uneven thickness of the plastic parts. During the cooling stage, the air cooling channel is automatically opened to achieve all-round uniform air cooling and shaping of the plastic parts, effectively eliminating internal stress of the plastic parts, preventing warping and deformation, and significantly improving the finished product qualification rate. This invention utilizes an integrated linkage structure between the intermittent duct blocking mechanism and the discharge blocking component. Starting from a design without independent power drive based on magnetic transmission and mechanical linkage, it achieves the effect of synchronous start and stop of duct blocking and discharge blocking without additional drive components. This simplifies the equipment structure, reduces equipment energy consumption and failure probability, and ensures precise synchronization of blocking, ventilation, and discharge processes, significantly improving the stability and linkage accuracy of equipment operation. Attached Figure Description

[0017] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof.

[0018] In the attached diagram: Figure 1 This is a three-dimensional structural schematic diagram of the present invention; Figure 2 This is a three-dimensional structural diagram from another perspective of the present invention; Figure 3 This is a schematic diagram of the structure of the discharge sealing component and the injection port anti-overflow component of the present invention in a separated state; Figure 4 This is a partial cross-sectional view of the injection anti-overflow sealing mechanism of the present invention; Figure 5 This is the present invention. Figure 4 Enlarged structural diagram at point A; Figure 6 This is a cross-sectional schematic diagram of the intermittent duct sealing mechanism of the present invention; Figure 7 This is the invention Figure 6 Enlarged structural diagram at point B; Figure 8 This is a partial structural schematic diagram of the intermittent duct sealing mechanism of the present invention; Figure 9 This is a schematic diagram of the mouth-shaped connecting frame structure of the present invention; Numbering on the map: 1. Injection molding machine body; 101. Mold clamping unit; 1011. Green column; 1012. Moving platen; 1013. Fixed platen; 1014. Crank connecting rod; 1015. Ejector rod; 102. Injection unit; 1021. Injection table; 1022. Heating module; 1023. Material receiving barrel; 1024. Feed screw; 1025. Hopper; 2. Injection anti-overflow sealing mechanism; 21. Injection port anti-overflow component; 211. Through port; 212. Feed limiting ring; 213. Feed port; 214. Fixed abutment plane; 215. Inner conical guide block; 216. Fitting inner conical surface; 217. Movable abutment plane; 218. Horizontal extrusion surface; 219. Spring movable cavity; 2110. Sliding fitting surface; 2111. Tight elastic element; 22. Discharge sealing component; 221. Barrel expansion cavity; 222. Sealing rod; 223. Barrel sealing block; 224. Barrel sealing inclined surface; 225. Converging discharge port; 3. Intermittent duct sealing mechanism; 301. Coaxial movable cavity; 302. Magnetic ring; 303. Magnetic column; 304. Vertical connecting ventilation duct; 305. Horizontal connecting ventilation duct; 306. Telescopic spring; 307. Orifice groove; 308. Vertical groove; 309. Connecting strip; 310. Orifice connecting frame; 311. Forward duct sealing slope; 312. Reverse duct sealing slope; 313. Synchronization column; 314. Forward duct sealing block; 315. Reverse duct sealing block. Detailed Implementation

[0019] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0020] Example: Figures 1 to 9 As shown, the present invention provides an injection molding equipment and method for a refrigerator PET transparent part, including an injection molding machine body 1, a mold clamping unit 101 and an injection unit 102 provided on the injection molding machine body 1, an injection anti-overflow sealing mechanism 2 and an intermittent air duct sealing mechanism 3 provided on the mold clamping unit 101 and the injection unit 102, and the injection anti-overflow sealing mechanism 2 further includes an injection port anti-overflow component 21 and a discharge sealing component 22. In the above embodiments, the injection anti-overflow sealing mechanism 2 is set to specifically solve the problems of easy overflow, material residue and slag ingress in the air duct during the injection molding of refrigerator PET transparent parts, which greatly improves the molding flatness and light transmittance of PET transparent parts. It is suitable for the mass production of high-transparency plastic parts such as refrigerator decorative strips, transparent covers and storage boxes. During the production process, the molten material is not easy to overflow, ensuring the utilization rate of materials. During the cooling and molding process of transparent parts, the molten material of injection unit 102 is not synchronously cooled and hardened by the intermittent sealing mechanism 3 in the air duct, thereby avoiding the material blockage problem caused by the hardening of material at the end of injection unit 102.

[0021] The mold clamping unit 101 includes four Green Columns 1011 disposed on the injection molding machine body 1. A movable template 1012 is slidably disposed on the Green Columns 1011. A fixed template 1013 is fixedly disposed on one side of the movable template 1012 on the injection molding machine body 1. A toggle connecting rod 1014 is symmetrically disposed on one side of the fixed template 1013. An ejector rod 1015 is disposed between the toggle connecting rods 1014 in the middle of the movable template 1012. The injection unit 102 includes an injection stage 1021 mounted on the injection molding machine body 1. A heating module 1022 is mounted on the injection stage 1021. A receiving cylinder 1023 is mounted inside the heating module 1022. A feeding screw 1024 is mounted inside the receiving cylinder 1023. A hopper 1025 is connected to the receiving cylinder 1023. In the above embodiments, the basic process of injection molding is achieved through the mold closing unit 101 and the injection unit 102. The four Green Pillars 1011 provide precise guidance and stable support for the opening and closing movement of the moving mold plate 1012, effectively avoiding the sliding deviation of the moving mold plate 1012 and the problem of mold closing misalignment, ensuring the mold closing accuracy, and avoiding defects such as flash and uneven thickness caused by mold closing gaps. The toggle connecting rod 1014, as a mold closing drive transmission structure, can amplify the mold closing and clamping force, ensuring the locking stability of the mold during high-pressure injection. In conjunction with the ejector rod 1015 set in the middle, the moving mold plate 1012 is pushed to the fixed mold plate 101. 3. A rapid mold closing operation is performed on one side. The hopper 1025 is used to continuously and quantitatively feed PET granule raw materials. The heating module 1022 can accurately control the temperature inside the container cylinder 1023 to match the melting temperature range of the PET raw materials, ensuring that the raw materials are fully and uniformly melted. The injection stage 1021 can drive the entire injection unit 102 to move horizontally, realizing the precise docking of the injection nozzle and the injection port of the fixed template 1013, providing a basic guarantee for high-precision injection molding. Subsequently, the feeding screw 1024 pushes the molten PET melt by rotation, realizing stable, uniform, and quantitative feeding, effectively improving the molding consistency of PET transparent parts.

[0022] like Figures 1 to 5 as well as Figure 9As shown, the injection port anti-overflow component 21 includes a through-hole 211 disposed on the fixed template 1013, an inner conical guide block 215 coaxially disposed in the middle of the through-hole 211, an inner conical surface 216 disposed on the inner conical guide block 215, a sliding contact surface 2110 disposed on the inner conical guide block 215, and a tight elastic member 2111 sleeved on the outer surface of the sliding contact surface 2110; In the above embodiment, the through-hole 211 serves as the mold cavity channel for the PET melt to enter the moving template 1012 and the fixed template 1013. The inner conical guide block 215 can guide the melt while adhering to the injection unit 102, reducing turbulence and flow during melt injection, and avoiding defects such as bubbles and flow marks inside the transparent part. The sliding bonding surface 2110 provides a basis for the reciprocating motion of the inner conical guide block 215. With the tight elastic element 2111, the inner conical guide block 215 can achieve adaptive bonding, maintaining the sealed state of the structure during injection docking and injection molding, thereby preventing melt overflow, reducing the generation of waste material, and ensuring stable injection pressure.

[0023] Furthermore, the injection port anti-overflow component 21 in the injection anti-overflow sealing mechanism 2 also includes a feed restriction ring 212 fixedly installed at the through port 211. The through port 211 is opened on the fixed template 1013. The feed port 213 is provided through the middle of the feed restriction ring 212. A fixed abutment plane 214 is provided on the side of the feed restriction ring 212 near the inner conical guide block 215. The sliding contact surface 2110 of the inner conical guide block 215 slides on the inner wall of the feed limiting ring 212. The inner conical guide block 215 is provided with a horizontal extrusion surface 218. A spring movable cavity 219 is provided between the horizontal extrusion surface 218 and the feed limiting ring 212. The tight elastic element 2111 on one side of the horizontal extrusion surface 218 is located in the spring movable cavity 219. The inner conical guide block 215 is provided with a movable abutment surface 217. The movable abutment surface 217 and the fixed abutment surface 214 are in contact with each other when the injection unit 102 extrudes. In the above embodiment, by fixing the feed limiting ring 212 inside the through-hole 211, the diameter of the melt feed port 213 can be limited, and the melt injection flow rate can be controlled. The inner conical guide block 215 slides with the inner wall of the feed limiting ring 212 through the sliding contact surface 2110. When the injection unit 102 is injection molding, the spring movable cavity 219 provides space for the expansion and contraction of the tight elastic element 2111. The tight elastic element 2111 is compressed by the extrusion force at the end of the injection unit 102, so that the inner conical guide block 215 is tightly attached to the injection unit 102, thereby preventing the melt from overflowing from the injection port gap.

[0024] like Figures 1 to 5As shown, the discharge sealing assembly 22 includes a sealing rod 222, a cylinder sealing block 223 is provided on the sealing rod 222, and a cylinder sealing inclined surface 224 is provided on the injection unit 102 on one side of the cylinder sealing block 223. The discharge sealing component 22 of the injection anti-overflow sealing mechanism 2 also includes a cylinder expansion cavity 221 provided on the receiving cylinder 1023. The cavity wall of the cylinder expansion cavity 221 is connected to the cylinder sealing inclined surface 224. The end of the feeding screw 1024 in the receiving cylinder 1023 is fixedly connected to the sealing rod 222. A converging discharge port 225 is provided on the side of the receiving cylinder 1023 near the inner conical guide block 215. The converging discharge port 225 has the same slope as the inner conical surface 216 of the inner conical guide block 215. In the above embodiment, the rotation of the feeding screw 1024 pushes the melt, which can simultaneously drive the sealing rod 222 to move in linkage, realizing the synchronization of feeding and sealing. The expansion cavity 221 of the barrel and the sealing slope 224 of the barrel form a gradually changing discharge channel, which can buffer the injection pressure of the melt. The converging discharge port 225 and the slope of the inner conical surface 216 are matched to achieve seamless connection of the discharge channel, ensuring smooth flow of the melt. After injection, the sealing rod 222 drives the barrel sealing block 223 to reset, and the sealing slope 224 of the barrel is aligned to complete the sealing of the discharge port. At the same time, the melt is slightly retracted to avoid the material remaining at the barrel discharge port being over-cooled by the cooling system of the mold closing module.

[0025] like Figures 1 to 9 As shown, the intermittent duct blocking mechanism 3 includes a vertical connecting duct 304 and a horizontal connecting duct 305. The vertical connecting duct 304 and the horizontal connecting duct 305 are interconnected. A forward duct blocking slope 311 and a reverse duct blocking slope 312 are symmetrically arranged on the horizontal connecting duct 305. The intermittent duct blocking mechanism 3 also includes an orifice groove 307 that is interconnected with the horizontal connecting duct 305. An orifice connecting frame 310 is arranged in the orifice groove 307. A synchronization column 313 is arranged on the orifice connecting frame 310. A forward duct blocking block 314 and a reverse duct blocking block 315 are arranged on the synchronization column 313. In the above embodiments, the vertical connecting ventilation channel 304 and the horizontal connecting ventilation channel 305 form a wind-cooling heat dissipation channel for the mold cavity, which is used for rapid and uniform cooling of the PET transparent parts after injection molding, avoiding problems such as internal stress and warping deformation caused by excessive local temperature differences in the transparent parts. The forward air channel blocking slope 311 and the reverse air channel blocking slope 312, together with the corresponding forward air channel blocking block 314 and the reverse air channel blocking block 315, achieve intermittent sealing of the air channels. When the forward air channel blocking slope... When 311 and the forward air duct blocking block 314 are in contact and sealed, it is the injection stage of the injection unit 102. At this time, the end of the synchronous column 313 and the inner cavity surface of the fixed module are on the same horizontal line. When the reverse air duct blocking slope 312 and the reverse air duct blocking block 315 are in contact, the seal between the vertical connecting ventilation duct 304 and the horizontal connecting ventilation duct 305 is released. At this time, the air cooling system can deliver cooling air from the vertical connecting ventilation duct 304 to the horizontal connecting ventilation duct 305 to cool and shape the transparent part.

[0026] Furthermore, the intermittent sealing mechanism 3 of the air duct also includes a coaxial movable cavity 301 coaxially arranged with the through port 211. A magnetic ring 302 is provided on the inner wall of the coaxial movable cavity 301. A telescopic spring 306 is provided on the side wall of the magnetic ring 302 inside the coaxial movable cavity 301. A magnetic column 303 is provided on one side of the magnetic ring 302 on the material cylinder sealing block 223. The magnetic ring 302 and the magnetic column 303 are initially arranged in a spaced-out repulsive manner. The intermittent sealing mechanism 3 of the air duct also includes a vertical groove 308 symmetrically and connectedly arranged in the middle of the orifice groove 307. Both the orifice groove 307 and the vertical groove 308 are arranged on the fixed template 1013. A connecting strip 309 is provided on the groove wall of the vertical groove 308. One end of the connecting strip 309 is connected to the magnetic ring 302, and the other end is connected to the orifice connecting frame 310. The orifice connecting frame 310 and the connecting strip 309 slide together on the groove walls of the orifice groove 307 and the vertical groove 308. The synchronous column 313 set on the mouth-shaped connecting frame 310 is located in the horizontal connecting ventilation duct 305. The horizontal connecting ventilation duct 305 and the vertical connecting ventilation duct 304 are both located on the fixed template 1013. The forward air duct blocking block 314 on the synchronous column 313 is used to block the forward air duct blocking slope 311, and the reverse air duct blocking block 315 on the synchronous column 313 is used to block the reverse air duct blocking slope 312. In the above embodiment, the repulsive magnetic force between the magnetic ring 302 and the magnetic column 303 enables the air duct blocking mechanism and the discharge blocking component 22 to operate synchronously and in conjunction, without the need for independent power drive, thus achieving integrated linkage of the mechanism. During the injection molding feeding process, the barrel blocking block 223 moves forward, the magnetic column 303 approaches the magnetic ring 302, and the repulsive magnetic force pushes the magnetic ring 302 to move, the telescopic spring 306 is compressed, and the connecting strip 309 drives the mouth-shaped connecting frame 310 to slide, so that the forward air duct blocking block 314 and the reverse air duct blocking block 315 can move together. The corresponding sealing slope is aligned to completely block the horizontal ventilation channel 305, preventing cold air from entering the cavity during injection molding, preventing the PET melt from cooling and solidifying prematurely, and avoiding cold spots, wrinkles, and burrs on the surface of the plastic part. After injection molding, the barrel sealing block 223 retracts, the magnetic column 303 moves away from the magnetic ring 302, and the thrust generated by the magnetic force is released. Under the action of the telescopic spring 306, the mouth connecting frame 310 drives the forward air channel sealing block 314 to reset, and the air channel automatically opens, realizing rapid and uniform air cooling of the cavity, improving molding efficiency and plastic part quality.

[0027] A method for using an injection molding equipment for a refrigerator PET transparent part, applicable to an injection molding equipment for a refrigerator PET transparent part, includes the following steps: S1: First, PET granules are filled into the receiving cylinder 1023 of the injection unit 102 through the hopper 1025. The heating module 1022 is started, and the temperature is precisely controlled according to the melting parameters of the PET raw material to stabilize the internal temperature of the cylinder within a fixed threshold, so that the PET raw material is fully and uniformly melted and plasticized to form a PET melt with stable flow. Then, the injection stage 1021 is driven to move the injection unit 102 as a whole, so that the converging discharge port 225 of the cylinder is precisely aligned with the through port 211 of the fixed template 1013, completing the precise fitting and docking of the injection unit 102 and the mold closing unit 101. Simultaneously, the mold closing unit 101 is started, and the toggle connecting rod 1014 drives the moving template 1012 to slide smoothly along the green column 1011, precisely closing and locking the mold cavity with the fixed template 1013, ensuring sufficient mold clamping force and avoiding mold expansion gaps during high-pressure injection. S2: During the entire process of the injection unit 102 and the mold clamping unit 101 fitting and docking, the tight elastic element 2111 of the injection port anti-overflow component 21 continuously outputs elastic force, pushing the inner conical guide block 215 to slide along the inner wall of the feed restriction ring 212, so that the inner conical surface 216 fits tightly against the end face of the constricted discharge port 225 of the injection unit 102, realizing a seamless sealing docking between the discharge port and the injection through port 211. Through the elastic adaptive fitting structure, the small assembly gap of the equipment docking is compensated, and the melt overflow from the docking gap in the early stage of injection molding is completely avoided. At the same time, the inner conical guide block 215 guides the melt to ensure that the melt feed is stable and there is no risk of turbulent overflow. S3: Start the feeding screw 1024 to rotate and advance, driving the sealing rod 222 to move forward synchronously, so that the barrel sealing block 223 is separated from the barrel sealing slope 224, releasing the discharge sealing state. The PET melt inside the barrel is smoothly injected into the mold cavity along the converging discharge port 225 and the inlet port 213, completing precise injection molding. After the injection molding and holding pressure process is completed, the feeding screw 1024 retracts slightly, driving the sealing rod 222 and the barrel sealing block 223 to reset, so that the barrel sealing block 223 is tightly attached to the barrel sealing slope 224, quickly sealing the barrel discharge channel and blocking the melt discharge. At the same time, the slight retraction action pulls the trace melt remaining at the discharge port back into the barrel expansion cavity 221, completely avoiding the dripping, stringing, and leakage of residual material at the discharge port, and preventing residual material from adhering to the surface of the transparent part and forming defects. S4: During the entire injection and holding pressure process in S3, the barrel sealing block 223 moves forward, causing the magnetic column 303 to approach the magnetic ring 302 inside the coaxial movable cavity 301. Utilizing magnetic repulsion, the magnetic ring 302 is displaced, causing the orifice connecting frame 310 to slide within the orifice groove 307 and vertical groove 308 via the connecting strip 309. This drives the forward air duct sealing block 314 on the synchronous column 313 to synchronously adhere to the forward air duct sealing slope 311, completely sealing the horizontal connecting ventilation duct 305 and blocking the air cooling channel. In this state, the mold cavity is in a sealed, constant-temperature environment, preventing cold air intrusion that could cause premature cooling of the melt, effectively... To prevent cold spots, burrs, and uneven thickness in transparent parts, after injection molding and pressure holding are completed and the discharge sealing component 22 is retracted and reset, the distance between the magnetic column 303 and the magnetic ring 302 increases and the magnetic force dissipates. The reverse air channel sealing block 315 blocks the reverse air channel sealing slope 312, and the horizontal connecting ventilation channel 305 and the vertical connecting ventilation channel 304 are fully connected. After the cold air system is turned on, the cold air is quickly introduced into the mold cavity to perform all-round uniform air cooling and shaping of the PET transparent parts inside the cavity, which greatly improves the cooling efficiency. At the same time, it ensures that the transparent parts are cooled evenly and without internal stress deformation. The plastic parts have better light transmittance and flatness after molding. S5: After the PET transparent part has completely cooled and solidified, release the mold locking state, and drive the moving platen 1012 to retract and open the mold using the toggle connecting rod 1014. Then, take out the molded refrigerator PET transparent part from the moving platen 1012 to complete the single molding operation. After cleaning the mold cavity debris, repeat the above steps S3 to S5 to carry out continuous batch injection molding production.

[0028] Through all the above embodiments, the working principle and usage process of the present invention are as follows:

[0029] This equipment quantitatively fills PET granules into the receiving cylinder 1023 of the injection unit 102 via the hopper 1025. The heating module 1022 is activated to precisely control the temperature and stabilize the temperature inside the cylinder within the suitable melting range for the PET granules, allowing the PET granules to fully and uniformly melt and plasticize, forming a stable PET melt. Subsequently, the injection stage 1021 drives the entire injection unit 102 to move horizontally, so that the converging discharge port 225 of the cylinder is precisely aligned with the through-hole 211 of the fixed mold plate 1013, completing the sealing connection between the injection unit 102 and the mold closing unit 101. At the same time, the mold closing unit 101 is activated, and the toggle connecting rod 1014 amplifies the mold locking power, driving the moving mold plate 1012 to slide smoothly along the four Green Pillars 1011. Through the precise guiding effect of the Green Pillars 1011, the moving and fixed mold plates 1013 are precisely closed and locked, avoiding mold gaps and preventing misalignment during high-pressure injection molding. Throughout the entire process of injection unit 102 joining the mold, the tight elastic element 2111 of injection port anti-overflow component 21 continuously outputs elastic force, pushing the inner conical guide block 215 to slide adaptively along the inner wall of the feed restriction ring 212, so that the inner conical surface 216 of the inner conical guide block 215 fits tightly with the barrel outlet, making up for the small gaps in the equipment assembly, achieving seamless sealing of the injection channel, and completely blocking the melt overflow channel. At the same time, the inner conical guide block 215 smoothly guides the PET melt, suppressing melt turbulence and flow phenomena, and avoiding the generation of bubbles and flow marks inside the plastic part. Subsequently, the feed screw 1024 rotates and advances, driving the sealing rod 222 to move forward synchronously, so that the barrel sealing block 223 disengages from the barrel sealing slope 224, releasing the discharge sealing state. The PET melt is smoothly injected into the mold cavity through the barrel expansion cavity 221, the converging discharge port 225, and the feed port 213, completing the high-pressure injection and holding pressure operation. After the injection molding and holding pressure process is completed, the feeding screw 1024 retracts slightly to reset, simultaneously driving the sealing rod 222 and the barrel sealing block 223 to move in the opposite direction, so that the barrel sealing block 223 fits tightly against the barrel sealing slope 224, quickly sealing the barrel outlet channel and immediately blocking the melt discharge. At the same time, the slight retraction of the screw can pull the trace amount of melt remaining at the outlet back into the barrel expansion cavity 221, preventing residual material from dripping, stringing, or adhering to the mold cavity or plastic part surface, and avoiding appearance defects and outlet blockage caused by residual material. During the injection and holding pressure processes, the barrel sealing block 223 moves forward, causing the magnetic column 303 to approach the magnetic ring 302 inside the coaxial movable cavity 301. The repulsive magnetic force between the magnetic ring 302 and the magnetic column 303 pushes the magnetic ring 302 to move. This displacement is achieved by the connecting strip 309 pulling the orifice connecting frame 310 to slide within the orifice groove 307 and vertical groove 308. This drives the synchronous column 313 to move the forward air duct sealing block 314 to conform to the forward air duct sealing slope 311, completely sealing the horizontal connecting air duct 305 and blocking the air cooling channel. This keeps the mold cavity in a sealed, constant-temperature state, preventing cold air intrusion that could cause premature cooling of the melt and avoiding defects such as cold spots, burrs, and uneven thickness. After the injection molding pressure is completed and the discharge sealing structure is reset, the distance between the magnetic column 303 and the magnetic ring 302 increases, the repulsive magnetic force dissipates, and the intermittent air duct sealing mechanism 3 is reset under the action of the extension spring 306. The horizontal connecting ventilation duct 305 and the vertical connecting ventilation duct 304 are fully connected. After the cold air system is started, cooling air is evenly delivered to the cavity to perform all-round uniform air cooling and shaping of the PET transparent part, avoiding internal stress in the plastic part and avoiding warping deformation. At this time, the reverse air duct sealing block 315 seals the reverse sealing slope to prevent the cooling air from entering the end of the injection unit 102, thereby avoiding the material blockage problem caused by the cooling and hardening of the melt at the end of the injection unit 102. After the PET transparent part has completely cooled and solidified, the mold locking state is released, and the toggle connecting rod 1014 drives the moving template 1012 to smoothly retreat to complete the mold opening. The workers take out the finished transparent part, clean the debris and foreign matter inside the mold cavity, and repeat the injection, sealing, cooling, and mold opening process to realize the continuous batch injection molding production of refrigerator PET transparent parts.

[0030] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An injection molding apparatus for a PET transparent part for a refrigerator, comprising an injection molding machine body (1), wherein the injection molding machine body (1) is provided with a mold clamping unit (101) and a glue injection unit (102), characterized in that: The mold closing unit (101) and the injection unit (102) are provided with an injection anti-overflow sealing mechanism (2) and an intermittent air duct sealing mechanism (3). The injection anti-overflow sealing mechanism (2) also includes an injection port anti-overflow component (21) and a discharge sealing component (22). The injection port anti-overflow component (21) includes a through port (211), an inner conical guide block (215) is coaxially arranged in the middle of the through port (211), an inner conical surface (216) is provided on the inner conical guide block (215), a sliding contact surface (2110) is provided on the inner conical guide block (215), and a tight elastic element (2111) is sleeved on the outer surface of the sliding contact surface (2110). The discharge sealing assembly (22) includes a sealing rod (222), a cylinder sealing block (223) is provided on the sealing rod (222), and a cylinder sealing inclined surface (224) is provided on the injection unit (102) on one side of the cylinder sealing block (223). The intermittent duct blocking mechanism (3) includes a vertical connecting duct (304) and a horizontal connecting duct (305). The vertical connecting duct (304) and the horizontal connecting duct (305) are interconnected. The horizontal connecting duct (305) is symmetrically provided with a forward duct blocking slope (311) and a reverse duct blocking slope (312). The intermittent duct blocking mechanism (3) also includes an orifice groove (307) interconnected with the horizontal connecting duct (305). An orifice connecting frame (310) is provided in the orifice groove (307). A synchronization column (313) is provided on the orifice connecting frame (310). A forward duct blocking block (314) and a reverse duct blocking block (315) are provided on the synchronization column (313).

2. The injection molding equipment for a refrigerator PET transparent part according to claim 1, characterized in that, The mold clamping unit (101) includes four Green Pillars (1011) arranged on the injection molding machine body (1). A movable template (1012) is slidably arranged on the Green Pillars (1011). A fixed template (1013) is fixedly arranged on one side of the movable template (1012) on the injection molding machine body (1). A toggle link (1014) is symmetrically arranged on one side of the fixed template (1013). An ejector rod (1015) is arranged between the toggle links (1014) in the middle of the movable template (1012).

3. The injection molding equipment for a refrigerator PET transparent part according to claim 1, characterized in that, The injection unit (102) includes an injection stage (1021) mounted on the injection machine body (1). A heating module (1022) is mounted on the injection stage (1021). A material receiving cylinder (1023) is mounted inside the heating module (1022). A feeding screw (1024) is mounted inside the material receiving cylinder (1023). A hopper (1025) is connected to the material receiving cylinder (1023).

4. The injection molding equipment for a refrigerator PET transparent part according to claim 1, characterized in that, The injection port anti-overflow component (21) in the injection anti-overflow sealing mechanism (2) also includes a feed restriction ring (212) fixedly installed at the through port (211). The through port (211) is opened on the fixed template (1013). The feed restriction ring (212) has a feed port (213) through the middle. The feed restriction ring (212) has a fixed abutment plane (214) on the side near the inner conical guide block (215).

5. The injection molding equipment for a refrigerator PET transparent part according to claim 4, characterized in that, The sliding contact surface (2110) of the inner conical guide block (215) slides on the inner wall of the feed limiting ring (212). A horizontal extrusion surface (218) is provided on the inner conical guide block (215). A spring movable cavity (219) is provided between the horizontal extrusion surface (218) and the feed limiting ring (212). A tight elastic element (2111) on one side of the horizontal extrusion surface (218) is located in the spring movable cavity (219). A movable abutting plane (217) is provided on the inner conical guide block (215). The movable abutting plane (217) and the fixed abutting plane (214) are in contact with each other when the injection unit (102) extrudes.

6. The injection molding equipment for a refrigerator PET transparent part according to claim 4, characterized in that, The discharge sealing assembly (22) of the injection anti-overflow sealing mechanism (2) further includes a cylinder expansion cavity (221) provided on the receiving cylinder (1023). The cavity wall of the cylinder expansion cavity (221) is connected to the cylinder sealing inclined surface (224). The end of the feeding screw (1024) in the receiving cylinder (1023) is fixedly connected to the sealing rod (222). A converging discharge port (225) is provided on the side of the receiving cylinder (1023) near the inner conical guide block (215). The slope of the converging discharge port (225) is consistent with the slope of the inner conical surface (216) of the inner conical guide block (215).

7. The injection molding equipment for a refrigerator PET transparent part according to claim 1, characterized in that, The intermittent sealing mechanism (3) of the air duct also includes a coaxial movable cavity (301) coaxially arranged with the through port (211). A magnetic ring (302) is provided on the inner wall of the coaxial movable cavity (301). A telescopic spring (306) is provided on the side wall of the magnetic ring (302) inside the coaxial movable cavity (301). A magnetic column (303) is provided on one side of the magnetic ring (302) on the material cylinder sealing block (223). The magnetic ring (302) and the magnetic column (303) are initially arranged in a spaced-out repulsive manner.

8. The injection molding equipment for a refrigerator PET transparent part according to claim 7, characterized in that, The intermittent sealing mechanism (3) of the air duct also includes a vertical groove (308) symmetrically and connectedly arranged in the middle of the mouth-shaped groove (307). The mouth-shaped groove (307) and the vertical groove (308) are both arranged on the fixed template (1013). A connecting strip (309) is provided on the groove wall of the vertical groove (308). One end of the connecting strip (309) is connected to the magnetic ring (302), and the other end is connected to the mouth-shaped connecting frame (310). The mouth-shaped connecting frame (310) and the connecting strip (309) slide together on the groove wall of the mouth-shaped groove (307) and the vertical groove (308).

9. The injection molding equipment for a refrigerator PET transparent part according to claim 8, characterized in that, The synchronizing column (313) set on the mouth-shaped connecting frame (310) is located in the horizontal connecting ventilation duct (305). The horizontal connecting ventilation duct (305) and the vertical connecting ventilation duct (304) are both located on the fixed template (1013). The forward air duct blocking block (314) on the synchronizing column (313) is used to block the forward air duct blocking slope (311). The reverse air duct blocking block (315) on the synchronizing column (313) is used to block the reverse air duct blocking slope (312).

10. A method of using an injection molding equipment for a refrigerator PET transparent part, applied to the injection molding equipment for a refrigerator PET transparent part according to claims 1 to 9, characterized in that, Includes the following steps: S1: First, the injection unit (102) is filled with PET raw material and melted. The injection unit (102) is driven to move and align and adhere to the mold closing unit (101). The mold closing unit (101) starts to close the mold. After the mold closing is completed, the injection unit (102) injects PET melt into the mold closing unit (101). S2: During the process of the injection unit (102) being attached to the mold closing unit (101), the inner conical guide block (215) in the injection port anti-overflow component (21) is tightly attached to the outlet of the injection unit (102) under the force of the tight elastic element (2111), so as to prevent PET melt from overflowing from the gap during injection. S3: When the injection unit (102) is injecting, the barrel sealing block (223) on the sealing rod (222) of the discharge sealing assembly (22) cooperates with the barrel sealing ramp (224) to release the sealing of the injection unit (102) of the molten material, so that the molten material can smoothly enter the mold closing unit (101). After the injection unit (102) completes one injection, the barrel sealing block (223) on the sealing rod (222) cooperates with the barrel sealing ramp (224) to seal the injection unit (102) and pull back part of the molten material to avoid material leakage. S4: When the discharge sealing assembly (22) is running, the intermittent air duct sealing mechanism (3) blocks the horizontal connecting air duct (305) to prevent the material from cooling prematurely during the injection process and to prevent the material from entering the air duct and forming burrs. When the discharge sealing assembly (22) retracts in the injection unit (102), it opens the horizontal connecting air duct (305) to connect with the vertical connecting air duct (304) to quickly cool the transparent part. S5: After the PET transparent part has completely cooled and solidified, release the mold locking state, take out the molded refrigerator PET transparent part, and complete the single molding operation. After cleaning the mold cavity debris, repeat the above steps S3 to S5 to carry out continuous batch injection molding production.

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