Injection molding equipment for producing PCB (Printed Circuit Board) fixed shell

Abstract

The invention discloses injection molding equipment for producing a PCB (printed circuit board) fixed shell, and relates to the technical field of injection molding, the injection molding equipment comprises a base station, and a molding mold, a control system and an injection system which are mounted on the base station, and the injection system comprises a heating charging barrel, an injection device and a charging module which are communicated with the molding mold; and the charging module comprises a hopper arranged above the charging section of the heating charging barrel. According to the invention, the modularized charging module design realizes the full-process automatic connection of crushing, screening, dehumidification and waste discharge, the raw material treatment rhythm is accurately matched with the injection molding period, and the standby time is shortened; after the screened and dried raw materials enter the heating charging barrel, the plasticizing uniformity is remarkably improved, the forming precision of the PCB fixing shell is guaranteed, especially in the production of thin-wall parts and complex structural parts, the problems of uneven wall thickness, uneven surface and the like can be effectively solved, the consistency and reliability of products meet the high requirements of electronic component packaging, and the production cost is reduced. And a solid guarantee is provided for large-scale production.

Description

Technical Field

[0001] The present invention relates to the technical field of injection molding, in particular to an injection molding device for producing a PCB fixed housing. Background Art

[0002] In the field of PCB fixed shell injection molding, the feeding modules of traditional injection molding equipment generally suffer from inefficient raw material handling. Specifically, during storage and transportation, raw materials are susceptible to moisture, agglomeration, or particle size variations, leading to problems such as heating barrel blockage and screw jamming. Uneven plasticization can also cause quality defects such as bubbles and stress concentration in the shell. Traditional screening mechanisms often use a single screening mode (e.g., patent publication number CN119369573B), which cannot balance raw material dehumidification and dynamic cleaning, resulting in high moisture retention and easy clogging of the screen holes. Regarding the drive structure, traditional equipment struggles to achieve coordinated motion control of the screening plate and the rotating drum, resulting in an inconsistent raw material handling process and a low degree of equipment automation. Furthermore, existing technologies lack dynamic optimization of the raw material conveying path, which can easily lead to residual and accumulated raw material on the inner wall of the rotating drum, further impacting production efficiency and product yield. Summary of the Invention

[0003] The object of the present invention is to provide an injection molding device for producing a PCB fixed housing to solve the problems raised in the above background technology.

[0004] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical solutions:

[0005] The present invention provides an injection molding device for producing a PCB fixed housing, comprising a base, a molding die mounted on the base, a control system, and an injection system. The injection system comprises a heating barrel connected to the molding die, an injection device, and a feeding module. The feeding module comprises a hopper disposed above the feeding section of the heating barrel, and a crushing mechanism and a screening mechanism disposed within the hopper.

[0006] The hopper is divided into a storage chamber, a screening chamber and a storage chamber from top to bottom by a separator. The screening chamber is a cylindrical cavity with a horizontal axis. A feed chute is reserved in the middle between the screening chamber and the cylindrical cavity. A discharge chute is reserved in the middle between the screening chamber and the storage chamber.

[0007] The screening mechanism includes a rotating drum that is rotatably adapted to the screening chamber, and a screening plate that is rotatably adapted to the rotating drum through a rotating shaft coaxially arranged with the screening chamber. Three connecting grooves are evenly arranged on the outer circumference of the rotating drum, a waste discharge channel is provided through the lower oblique side of the cylindrical cavity, and sieve holes are provided on the screening plate. The rotating shaft is connected to a first driving component to drive the screening plate to swing forward and backward in a horizontal state. The rotating drum is connected to a second driving component to drive it to rotate. The rotating shaft is connected to the second driving component to drive the screening plate to swing forward and backward in a horizontal state.

[0008] Furthermore, the crushing device is a component that can perform at least one crushing operation of shearing, extruding or grinding on the molding material.

[0009] Furthermore, a conical structure is provided at the bottom of the storage cavity, and the transverse surface thereof decreases continuously from top to bottom, so that the molding material flows centrally toward the feed trough.

[0010] Furthermore, a sealing plate is welded to one end of the rotating drum, and a through hole is reserved in the center of the sealing plate for the rotating shaft to pass through. A rotating tube is coaxially fixed to the through hole on the side of the sealing plate away from the rotating drum, and the rotating tube passes through the hopper, and the rotating shaft passes through the screening plate transversely and is circumferentially locked with the screening plate by a keyway. The rotating shafts on both sides of the screening plate are respectively a driving end and a transmission end. The driving end passes through the hopper and is transmission-connected to the first driving component. The first driving component is a motor, and the transmission end passes through the rotating tube and is rotationally connected thereto. The second driving component includes a gear transmission mechanism arranged between the rotating tube and the transmission end, and the gear transmission mechanism is configured to drive the rotating tube to rotate when the driving end rotates in the positive direction.

[0011] Furthermore, the gear transmission mechanism includes a first gear fixedly mounted on the transmission end, a second gear fixedly mounted on the rotating tube, and a transmission gear set for connecting the first gear and the second gear. The outer wall of the hopper is fixed with a transmission bin covering the gear transmission mechanism. The transmission gear set includes a rotating shaft rotatably arranged in the transmission bin, a third gear mounted on the rotating shaft through a one-way bearing and meshing with the first gear, and a fourth gear fixedly mounted on the rotating shaft and meshing with the second gear.

[0012] Furthermore, the screening plate divides the inside of the drum into symmetrical upper and lower cavities, and the feeding module also includes a dehumidification component arranged in the screening cavity, the dehumidification component includes an outlet pipe extending into the upper cavity, and an inlet pipe extending into the lower cavity, the inlet pipe is connected to an external hot air source to guide the hot air into the lower cavity, and the outlet pipe is connected to an external exhaust fan to discharge moisture.

[0013] Furthermore, the air outlet pipe and the air inlet pipe are both parallel to the rotating axis, wherein the air outlet pipe is arranged directly below the feed trough, and a conical air suction hopper is installed on the lower half of the air outlet pipe, and the air inlet pipe has two pipes and is symmetrically arranged on both sides of the upper cavity, and the outer periphery of the air inlet pipe is evenly provided with air injection holes.

[0014] Furthermore, the screening plate elastically collides with the two air inlet pipes respectively during the positive and negative swinging in the horizontal state.

[0015] Furthermore, the width of the discharge trough is smaller than the distance between the two connecting grooves.

[0016] Furthermore, a scraper plate is vertically arranged at the center position of the bottom of the screening plate, the bottom of the scraper plate is in contact with the inner wall of the drum, and the scraper plate and the rotating shaft are in the same plane, and inclined guide grooves are evenly opened on the scraper plate.

[0017] Compared with the existing technology, one or more of the above technical solutions have the following beneficial effects:

[0018] 1. The coordinated design of the crushing mechanism and screening mechanism of the present invention solves the problems of raw material agglomeration and uneven particle size from the source. Specifically, the crushing shaft is equipped with radial blades to shear large pieces of raw material into uniform particles. Combined with the positive and negative oscillating motion of the screening plate, the raw material forms a high-frequency rolling trajectory on the screen surface, ensuring the particle size screening accuracy; the conical storage chamber uses gravity to guide the raw material to flow centrally to the feed trough, significantly improving the smoothness of raw material transportation, providing uniform and stable material input for the subsequent plasticizing process, and fundamentally reducing the risk of blockage in the heating barrel flow channel.

[0019] 2. The elastic collision structure between the screening plate and the intake pipe in this invention combines self-cleaning and enhanced dehumidification. Specifically, the periodic collision between the screening plate and the intake pipe during deflection generates high-frequency vibrations, effectively removing fine powder and lumps adhering to the sieve holes, maintaining screening efficiency. Simultaneously, this collision causes the raw material to churn violently, increasing the interparticle spacing and allowing the hot air ejected from the intake pipe to penetrate the raw material layer in all directions, creating a 360-degree drying cycle with no blind spots. The matching dimensions of the rotating drum and the discharge chute create a closed space during the dehumidification phase, extending the contact time between the hot air and the raw material, ensuring sufficient moisture removal, and fundamentally preventing defects such as bubbles and deformation in injection molded products caused by damp raw materials.

[0020] 3. The unidirectional transmission characteristics of the present invention's gear transmission mechanism enable precise coordinated control of the screening plate and drum. Specifically, during forward rotation, material screening and drum waste discharge are synchronized, while during reverse rotation, only the screening plate deflects. This time-sharing control mode improves screening efficiency and reduces inefficient energy consumption. The scraper plate's design, which fits snugly against the inner wall of the drum, dynamically removes residual material from the wall, while the inclined guide chute guides material toward the discharge chute, preventing accumulation and significantly reducing equipment maintenance frequency.

[0021] 4. The modular feeding module design of the present invention realizes the automated connection of the entire process of crushing, screening, dehumidification and waste discharge, and the raw material processing rhythm is precisely matched with the injection molding cycle, reducing standby time. After the screened and dried raw materials enter the heating barrel, the plasticization uniformity is significantly improved, and the molding accuracy of the PCB fixed shell is guaranteed. Especially in the production of thin-walled parts and complex structural parts, it can effectively avoid problems such as uneven wall thickness and uneven surface. The product consistency and reliability meet the high requirements of electronic component packaging, providing a solid guarantee for large-scale production.

[0022] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0024] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0025] Figure 2 This is a schematic structural diagram of the feeding module from the first perspective of the present invention;

[0026] Figure 3 This is a schematic structural diagram of the feeding module from a second perspective of the present invention;

[0027] Figure 4 2. It is a schematic diagram of the top view of the feeding module of the present invention;

[0028] Figure 5 yes Figure 4 AA structural diagram;

[0029] Figure 6 This is a schematic structural diagram of the screening mechanism of the present invention from a first perspective;

[0030] Figure 7 yes Figure 6 Schematic diagram of the local structure at A;

[0031] Figure 8 2. It is a schematic diagram of the screening mechanism of the present invention from a second viewing angle.

[0032] In the picture:

[0033] 1-base; 2-molding mold; 3-control system; 4-injection system; 41-heating barrel; 42-injection device; 43-feeding module; 5-hopper; 51-storage chamber; 511-conical structure; 52-screening chamber; 53-storage chamber; 54-feed trough; 55-discharge trough; 56-waste discharge channel; 6-crushing mechanism; 7-screening mechanism; 71-rotating drum; 711-connecting trough; 712-sealing plate; 713-rotating tube; 714-upper chamber; 715-lower chamber; 72-rotating shaft; 721 -driving end; 722-transmission end; 73-screening plate; 731-sieve hole; 74-first driving component; 75-second driving component; 751-gear transmission mechanism; 7511-first gear; 7512-second gear; 7513-rotating shaft; 7514-one-way bearing; 7515-third gear; 7516-fourth gear; 7517-transmission chamber; 8-dehumidification component; 81-exhaust pipe; 82-conical suction hopper; 82-inlet pipe; 821-jet hole; 83-scraper plate; 84-material guide trough. DETAILED DESCRIPTION

[0034] In order to enable those skilled in the art to better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of this application.

[0035] See also Figures 1-8 The present invention provides an injection molding device for producing a PCB fixed shell, comprising a base 1, a molding die 2, a control system 3, and an injection system 4 installed on the base 1, wherein the base 1 provides stable support for the equipment, and the molding die 2 consists of a fixed mold and a movable mold that cooperate with each other, and the two realize opening and closing actions under the drive of the clamping system, and the internal cavity is designed according to the shape and size of the PCB fixed shell to provide space for plastic molding; the control system 3 is based on PLC and is equipped with a touch screen human-machine interface. It uses various sensors to collect parameters such as temperature, pressure, position, etc. during the operation of the equipment in real time, and accurately controls the operation of the clamping system and the injection system 4 according to a preset program.

[0036] The injection system 4 comprises a heating barrel 41, an injection device 42, and a feeding mechanism, all connected to the forming mold 2. The heating barrel 41 is a cylindrical structure with a segmented heating design. It is axially divided into a feeding section, a compression section, and a homogenizing section. A screw is mounted within the heating barrel 41 via a bearing and driven by a servo motor via a synchronous belt drive. The screw thread depth gradually decreases from the feeding section to the homogenizing section, thereby achieving the functions of conveying, compacting, plasticizing, and homogenizing the plastic raw material.

[0037] The injection device 42 consists of an injection cylinder and a nozzle. The injection cylinder is horizontally installed on the base 1. Its piston rod is fixedly connected to the end of the screw. The screw is pushed to reciprocate along the axial direction through the pressure change of the hydraulic oil in the cylinder, thereby realizing the function of injecting the molten plastic into the cavity of the molding mold 2 at high speed and high pressure through the nozzle; the feeding module 43 is arranged above the feeding section of the heating barrel 41, and is used to transport molding material to the feeding section.

[0038] In the injection molding production of PCB fixed shells, the traditional feeding module 43 has significant disadvantages. The raw materials are very likely to clump during storage and transportation, and the particle sizes of the raw materials are uneven. This will not only cause blockage of the internal flow channel of the heating barrel 41 and affect the injection molding efficiency, but also cause quality defects such as bubbles and uneven surface in the PCB fixed shell due to uneven plasticization of the raw materials. In severe cases, it may even damage the four components of the injection system, increasing equipment maintenance costs.

[0039] In order to solve the above problems, this equipment has carried out targeted optimization design on the feeding module 43. Specifically, the feeding module 43 includes a hopper 5 arranged above the feeding section of the heating barrel 41, and a crushing mechanism 6 and a screening mechanism 7 arranged in the hopper 5. The hopper 5 is the core carrier of the feeding module 43 and is cleverly divided into three functional areas, namely a storage chamber 51, a screening chamber 52 and a storage chamber 53, by a partition. Among them, the storage chamber 51 is used to temporarily store the molding materials crushed by the crushing mechanism 6, providing a buffer space for subsequent processing; the screening chamber 52 is a cylindrical cavity with a horizontal axis. The feed trough 54 is reserved at the center position between it and the storage chamber 51 to achieve the orderly introduction of raw materials. The discharge trough 55 is reserved at the center position between the screening chamber 52 and the storage chamber 53 to ensure the smooth transportation of qualified raw materials; the storage chamber 53 is used to store high-quality raw materials after screening, waiting to be injected into the heating barrel 41.

[0040] The screening mechanism 7 is the key to the entire feeding module 43. Specifically, it comprises a rotating drum 71 and a screening plate 73. The drum 71 rotates within the screening chamber 52. Three evenly distributed communication slots 711 on its outer circumference cooperate with the waste discharge channel 56 extending diagonally below and extending along its side, forming a discharge path for unqualified raw materials. The screening plate 73 rotates within the drum 71 via a rotating shaft 72 coaxial with the screening chamber 52. The densely distributed sieve holes 731 on the screening plate 73 are precisely designed based on the raw material particle size required for injection molding.

[0041] The first driving component 74 is connected to the rotating shaft 72, and can drive the screening plate 73 to perform forward and reverse swinging motion in a horizontal state. This movement mode can make the raw material move in a continuous rolling trajectory on the surface of the screening plate 73, effectively avoiding the blockage of the screen hole 731 and improving the screening efficiency.

[0042] The second driving component 75 is connected to the drum 71, driving the drum 71 to rotate, so that the crushed molding materials can be introduced into the upper part of the screening plate 73 from the feed trough 54 in batches and in an orderly manner. This intermittent design, on the one hand, prevents a large amount of raw materials from instantly rushing into the screening chamber 52 and causing accumulation, and ensures that the screening plate 73 has sufficient working space to fully screen each batch of raw materials; on the other hand, during the rotation of the drum 71, the connecting groove 711 on its outer peripheral surface can be intermittently connected to the waste discharge channel 56. When the connecting groove 711 rotates to align with the waste discharge channel 56, unqualified raw materials generated during the screening process, such as agglomerated materials, oversized particles or impurities, are quickly discharged through the connecting groove 711 into the waste discharge channel 56 under the action of gravity and centrifugal force, thereby preventing unqualified raw materials from being retained in the screening chamber 52 and ensuring that the interior of the screening chamber 52 is always in a clean and efficient working state. In this way, not only is the stable and efficient operation rhythm of the screening mechanism 7 maintained, but the frequency of equipment failures caused by raw material accumulation and blockage is also reduced, the service life of the equipment is extended, and at the same time, it is ensured that only high-quality raw materials that meet the particle size requirements enter the storage chamber 53, laying a solid foundation for the subsequent uniform plasticization of the heating barrel 41 and the high-precision injection molding of the PCB fixed shell, effectively improving the overall production quality and efficiency.

[0043] In this embodiment, the crushing device is a component capable of performing at least one of shearing, extruding, or grinding operations on the molding material. Specifically, the crushing mechanism 6 includes crushing shafts symmetrically mounted on the top of the storage chamber 51. The pair of crushing shafts are driven by a drive motor fixed to the hopper 5. Multiple sets of crushing blades are spaced axially on the crushing shafts. Each set of crushing blades includes multiple blades arranged radially. The drive motor drives the crushing shafts to rotate at high speed, and the crushing blades cut and crush the molding material entering the storage chamber 51, reducing large pieces of material to smaller particles.

[0044] In the injection molding raw material conveying link, if the raw material in the storage cavity 51 does not flow smoothly, it is easy to cause accumulation and blockage, affecting the subsequent screening efficiency and feeding stability. To this end, in this embodiment, a conical structure 511 is provided at the bottom of the storage cavity 51, and its cross-section decreases continuously from top to bottom, so that the molding material flows toward the feed trough 54. The conical structure 511 uses the principle of gravity to change the movement trajectory of the raw material in the storage cavity 51, so that the molding material naturally slides down and converges along the conical wall under the action of its own gravity, and finally flows toward the feed trough 54, ensuring that the raw material can continuously and stably enter the screening cavity 52, providing a coherent material supply for the subsequent screening process, and ensuring the efficient and orderly operation of the entire injection molding process.

[0045] During the actual operation of the injection molding equipment, if the screening mechanism 7 lacks a stable and coordinated driving structure, it is easy for the rotating drum 71 and the screening plate 73 to move out of sync, resulting in poor raw material screening effect and low efficiency. Based on this, this embodiment optimizes the design of the driving connection structure of the screening mechanism 7. A sealing plate 712 is welded to one end of the rotating drum 71. The through hole reserved in the center of the sealing plate 712 not only provides a through channel for the rotating shaft 72, but also penetrates the hopper 5 through the coaxially fixed rotating tube 713, forming a stable support and transmission foundation. The rotating shaft 72 passes through the screening plate 73 horizontally and is circumferentially locked with the screening plate 73 through a keyway, so that the two can rotate synchronously, ensuring that the swaying action of the screening plate 73 is accurate and effective.

[0046] Among them, the rotating shaft 72 on both sides of the screening plate 73 is clearly divided into a driving end 721 and a transmission end 722. The driving end 721 directly passes through the hopper 5 and is connected to the forward and reverse motor. The forward and reverse motor serves as the first driving component 74, which can flexibly output forward and reverse instructions, provide high-frequency forward and reverse swinging force for the screening plate 73, so that the raw material forms a complex and efficient motion trajectory on the screening plate 73, greatly improving the screening effect, and the transmission end 722 passes through the rotating tube 713 on the sealing plate 712 of the rotating drum 71 and is rotatably connected to it.

[0047] The second drive component 75 includes a gear transmission mechanism 751 disposed between the rotating tube 713 and the transmission end 722. Its unique one-way transmission characteristics are key to achieving precise control. When the forward and reverse motors drive the rotating shaft 72 in forward rotation, the shaft 72 causes the screening plate 73 to yaw. Simultaneously, the transmission end 722 transmits power to the rotating tube 713 via the gear transmission mechanism 751, which in turn drives the drum 71 to rotate synchronously by a certain angle. When the forward and reverse motors drive the rotating shaft 72 to rotate in the opposite direction, due to the one-way transmission design of the gear transmission mechanism 751, the transmission end 722 of the rotating shaft 72 cannot transmit power to the rotating tube 713, and the rotating drum 71 is immediately in a stationary state, and only the screening plate 73 performs reverse deflection. In this mode, the screening plate 73 drives the rotating drum 71 to rotate continuously through continuous periodic swing, so that the rotating drum 71 cooperates with the screening plate 73 to intermittently introduce the crushed molding material on the one hand, and on the other hand, it is connected with the waste discharge channel 56 through the peripheral connecting groove 711 to discharge unqualified raw materials, thereby realizing an efficient screening cycle. This structure not only ensures the screening efficiency, but also realizes the refined control of the screening process, significantly improving the intelligence and automation level of the equipment.

[0048] Specifically, the gear transmission mechanism 751 includes a first gear 7511 fixedly assembled on the transmission end 722, a second gear 7512 fixedly assembled on the rotating tube 713, and a transmission gear group for connecting the first gear 7511 and the second gear 7512. The outer wall of the hopper 5 is fixed with a transmission bin 7517 covering the gear transmission mechanism 751. The transmission gear group includes a rotating shaft 7513 rotatably set in the transmission bin 7517, a third gear 7515 assembled on the rotating shaft 7513 through a one-way bearing 7514 and meshed with the first gear 7511, and a fourth gear 7516 fixedly assembled on the rotating shaft 7513 and meshed with the second gear 7512.

[0049] When the forward and reverse motors drive the rotating shaft 72 in the forward direction, the first gear 7511 of the transmission end 722 rotates clockwise, driving the meshed third gear 7515 to rotate counterclockwise. Due to the wedging action of the one-way bearing 7514, the torque of the third gear 7515 is transmitted to the rotating shaft 7513, causing it to rotate synchronously. The fourth gear 7516, fixed to the rotating shaft 7513, rotates accordingly, driving the meshed second gear 7512, which in turn rotates the rotating tube 713 clockwise, thereby causing the rotating drum 71 to rotate synchronously. When the motor drives the rotating shaft 72 in the reverse direction, the first gear 7511 rotates counterclockwise, driving the third gear 7515 to rotate clockwise. At this point, the rollers of the one-way bearing 7514 disengage due to centrifugal force, causing the third gear 7515 to idle. The rotating shaft 7513 receives no power, and the rotating drum 71 remains stationary.

[0050] During the injection molding process of the PCB mounting housing, moisture in the raw material not only degrades the plasticization process, affecting the housing's molding precision and strength, but can also create defects such as bubbles during injection molding, reducing product yields. To address this issue, this embodiment incorporates a dehumidification assembly 8 within the screening chamber 52 of the feeding module 43 to specifically address the moisture issue. A screening plate 73 divides the interior of the rotating drum 71 into symmetrical upper and lower chambers 714 and 715, creating a suitable space for the circulation of the dehumidified airflow.

[0051] Dehumidification assembly 8 includes an outlet pipe 81 extending into upper chamber 714 and an inlet pipe 82 extending into lower chamber 715. Inlet pipe 82 connects to an external hot air source and precisely directs the hot air into lower chamber 715. The hot air diffuses within lower chamber 715, fully interacting with the moist raw materials and rapidly removing moisture from them. As the hot air absorbs moisture, it transforms into humidity, which is then extracted and discharged through outlet pipe 81 by an external exhaust fan. This creates a directional airflow cycle within drum 71, with air entering from lower chamber 715 and exiting from upper chamber 714. During this process, the rotation of drum 71 and the oscillation of screening plate 73 work in tandem to continuously tumble and move the raw materials, ensuring that every portion of the raw materials is fully exposed to the hot air, significantly improving dehumidification efficiency. Whether the raw materials are in the screening process or temporarily stored in the rotating drum 71 waiting for screening, the dehumidification component 8 can continue to work to ensure that the dryness of the raw materials entering the heating barrel 41 meets the standards, effectively avoiding injection molding quality problems caused by moisture in the raw materials, providing strong guarantees for the molding of high-quality PCB fixed shells, and at the same time reducing production losses and defective rates caused by raw material humidity problems.

[0052] In the processing of raw materials for injection molding of PCB fixed shells, if the dehumidification airflow is unevenly distributed, it is easy to cause insufficient dehumidification of the raw materials, affecting the quality of subsequent injection molding. This embodiment optimizes the design of the air outlet pipe 81 and the air inlet pipe 82 of the dehumidification component 8, significantly improving the dehumidification effect. The air outlet pipe 81 and the air inlet pipe 82 are both arranged parallel to the rotating shaft 72, so that the air flow direction is adapted to the movement trajectory of the raw materials in the rotating drum 71. The air outlet pipe 81 is arranged directly below the feed trough 54, and the conical air suction hopper 82 installed on its lower half expands the suction area, generates a stronger negative pressure suction force, and quickly gathers and discharges the moisture released by the raw materials. Two air inlet pipes 82 are symmetrically located on either side of the upper cavity 714. Air jets 821 uniformly distributed around their periphery diffuse the hot air evenly, avoiding local temperature differences and dead zones. As the drum 71 rotates and the screening plate 73 deflects, the raw materials continuously move within the drum 71. Hot air ejected from the air inlet pipes 82 penetrates the raw materials in all directions, achieving 360-degree dehumidification without dead zones. The conical air scoop 82 of the air outlet pipe 81 simultaneously and efficiently extracts moisture, creating a stable airflow cycle. This design ensures that every piece of raw material is thoroughly dried, significantly reducing the risk of defects such as bubbles and deformation in the PCB mounting housing caused by moisture in the raw material, significantly improving product qualification rates and production stability.

[0053] In this embodiment, the screening plate 73 collides with the two air inlet pipes 82 during its horizontal forward and reverse swing. When the screening plate 73 swings and collides with the air inlet pipes 82, the high-frequency vibration generated at the moment of collision effectively removes blockages such as fine powder and moisture-induced agglomerates adhering to the sieve holes 731. This solves the problem of traditional vibration inability to thoroughly clean the sieve holes 731, ensuring the continuous and efficient operation of the screening process. Furthermore, the collision causes the raw materials to churn violently, increasing the spaces between particles and allowing the hot air ejected from the air inlet pipes 82 to more fully penetrate the raw material layer, significantly improving heat exchange efficiency.

[0054] Specifically, two groups of elastic collision components (not shown) are symmetrically arranged on the edge of the screening plate 73. Each group of elastic collision components is composed of a polyurethane buffer block, a spring steel sheet and an adjusting bolt, and each group of elastic collision components is arranged corresponding to the corresponding intake pipe 82.

[0055] Furthermore, the width of the discharge trough 55 is smaller than the distance between the two connecting grooves 711. Based on the above arrangement, when the drum 71 rotates to the point where the connecting groove 711 corresponds to the feed port, the discharge trough 55 is completely blocked by the solid part of the drum 71, forming a closed dehumidification space. The external hot air source delivers hot air into the lower cavity 715 through the air inlet pipe 82. Since the discharge trough 55 is blocked, the hot air can only circulate in the screening cavity 52, fully contacting the raw materials and taking away the moisture therein; while the moisture is discharged through the air outlet pipe 81 under the action of the external exhaust fan. This design ensures that the hot air continuously acts on the raw materials in the closed space, prolongs the contact time between the hot air and a single batch of raw materials, significantly improves the dehumidification efficiency and effect, and ensures that the dryness of the raw materials entering the heating barrel 41 meets the requirements of injection molding.

[0056] In this embodiment, a scraper plate 83 is vertically arranged at the center position of the bottom of the screening plate 73. The bottom of the scraper plate 83 is in contact with the inner wall of the rotating drum 71, and the scraper plate 83 and the rotating shaft 72 are on the same plane. Inclined material guide grooves 84 are evenly opened on the scraper plate 83. Based on the above-mentioned setting, when the screening plate 73 is driven by the forward and reverse motors to perform horizontal forward and reverse deflection, and the drum 71 is driven by the second driving component 75 to rotate, the scraper plate 83 moves synchronously therewith, and its bottom continuously scrapes the inner wall of the drum 71 to scrape off the raw materials attached to the wall, and at the same time turns over the raw materials accumulated at the bottom of the drum 71 to break the static accumulation state of the raw materials. The inclined guide trough 84 on the scraper plate 83 will exert an oblique force on the passing raw materials during the movement. The inclination angle of the guide trough 84 is used to make the raw materials continuously roll and move during the pushing process, forming a complex motion trajectory. This movement mode causes the raw material particles to rub and collide with each other, which can not only further break up the possible small agglomerated raw materials, but also increase the contact area between the raw materials and the hot air, promote the discharge of moisture, and enhance the dehumidification effect.

[0057] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. An injection molding device for producing a PCB fixed shell, comprising a base (1), a molding die (2) mounted on the base (1), a control system (3) and an injection system (4), wherein the injection system (4) comprises a heating barrel (41) connected to the molding die (2), an injection device (42) and a feeding module (43), and is characterized in that: The feeding module (43) includes a hopper (5) arranged above the feeding section of the heating barrel (41), and a crushing mechanism (6) and a screening mechanism (7) arranged in the hopper (5); The hopper (5) is divided into a storage chamber (51), a screening chamber (52) and a storage chamber (53) in sequence from top to bottom by a partition, the screening chamber (52) being a cylindrical chamber with its axis arranged horizontally, a feed trough (54) being reserved in the middle between the screening chamber (52) and the cylindrical chamber, and a discharge trough (55) being reserved in the middle between the screening chamber (52) and the storage chamber (53); The screening mechanism (7) includes a rotating drum (71) adapted to rotate in the screening chamber (52), and a screening plate (73) adapted to rotate in the rotating drum (71) via a rotating shaft (72) coaxially arranged with the screening chamber (52), three connecting grooves (711) are evenly arranged on the outer peripheral surface of the rotating drum (71), a waste discharge channel (56) is provided through the lower oblique side of the cylindrical cavity, and a sieve hole (731) is provided on the screening plate (73), the rotating shaft (72) is connected to a first driving component (74) to drive the screening plate (73) to swing forward and backward in a horizontal state, the rotating drum (71) is connected to a second driving component (75) to drive it to rotate, and the rotating shaft (72) is connected to the second driving component (75) to drive the screening plate (73) to swing forward and backward in a horizontal state.

2. The injection molding equipment for producing a PCB fixed housing according to claim 1, characterized in that: The crushing device is a component that can perform at least one crushing operation of shearing, extruding or grinding on the molding material.

3. The injection molding equipment for producing a PCB fixed housing according to claim 1, characterized in that: The bottom of the storage cavity (51) is provided with a conical structure (511), the transverse surface of which decreases continuously from top to bottom, so that the molding material flows concentratedly toward the feed trough (54).

4. The injection molding equipment for producing a PCB fixed housing according to claim 3, characterized in that: A sealing plate (712) is welded to one end of the rotating drum (71), and a through hole is reserved in the center of the sealing plate (712) for the rotating shaft (72) to pass through. A rotating tube (713) is coaxially fixed to the through hole on the side of the sealing plate (712) away from the rotating drum (71), and the rotating tube (713) passes through the hopper (5). The rotating shaft (72) passes through the screening plate (73) transversely and is circumferentially locked with the screening plate (73) through a keyway. The rotating shafts (72) on both sides of the screening plate (73) are respectively the driving end (721) and the The transmission end (722) is connected to the first driving component (74) by transmission. The first driving component (74) is a motor. The transmission end (722) is connected to the rotating tube (713) by rotation. The second driving component (75) includes a gear transmission mechanism (751) provided between the rotating tube (713) and the transmission end (722). The gear transmission mechanism (751) is configured to rotate the rotating tube (713) when the driving end (721) rotates in the forward direction.

5. The injection molding equipment for producing a PCB fixed housing according to claim 4, characterized in that: The gear transmission mechanism (751) comprises a first gear (7511) fixedly mounted on the transmission end (722), a second gear (7512) fixedly mounted on the rotating tube (713), and a transmission gear set for connecting the first gear (7511) and the second gear (7512). A transmission chamber (7517) covering the gear transmission mechanism (751) is fixedly mounted on the outer wall of the hopper (5). The transmission gear set comprises a rotating shaft (7513) rotatably disposed in the transmission chamber (7517), a third gear (7515) mounted on the rotating shaft (7513) via a one-way bearing (7514) and meshing with the first gear (7511), and a fourth gear (7516) fixedly mounted on the rotating shaft (7513) and meshing with the second gear (7512).

6. The injection molding equipment for producing a PCB fixed housing according to claim 1, characterized in that: The screening plate (73) divides the interior of the drum (71) into a symmetrical upper cavity (714) and a lower cavity (715). The feeding module (43) further includes a dehumidification assembly (8) arranged in the screening cavity (52). The dehumidification assembly (8) includes an air outlet pipe (81) extending into the upper cavity (714) and an air inlet pipe (82) extending into the lower cavity (715). The air inlet pipe (82) is connected to an external hot air source to guide the hot air into the interior of the lower cavity (715). The air outlet pipe (81) is connected to an external exhaust fan to discharge moisture.

7. The injection molding equipment for producing a PCB fixed housing according to claim 6, characterized in that: The air outlet pipe (81) and the air inlet pipe (82) are both parallel to the rotating shaft (72), wherein the air outlet pipe (81) is arranged directly below the feed trough (54), and a conical air suction hopper (82) is installed on the lower half of the air outlet pipe (81), and the air inlet pipe (82) has two pipes and is symmetrically arranged on both sides of the upper cavity (714), and the outer periphery of the air inlet pipe (82) is evenly provided with air injection holes (821).

8. The injection molding equipment for producing a PCB fixed housing according to claim 7, characterized in that: The screening plate (73) elastically collides with the two air inlet pipes (82) during the positive and negative swinging in the horizontal state.

9. The injection molding equipment for producing a PCB fixed housing according to claim 6, characterized in that: The width of the discharge trough (55) is smaller than the distance between the two connecting grooves (711).

10. The injection molding equipment for producing a PCB fixed housing according to claim 9, characterized in that: A scraper plate (83) is vertically arranged at the center of the bottom of the screening plate (73). The bottom of the scraper plate (83) is in contact with the inner wall of the rotating drum (71), and the scraper plate (83) and the rotating shaft (72) are in the same plane. Inclined guide grooves (84) are evenly opened on the scraper plate (83).

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