Temperature control forming process of photovoltaic nylon connector die and composite runner

Abstract

The invention relates to the technical field of photovoltaic connector manufacturing, in particular to a temperature control forming process of a photovoltaic nylon connector mold and a composite runner, the mold is divided into a fixed mold area, a movable mold area, a mold cavity area, a mold core area and a pouring gate area, and each area is provided with an independent temperature control loop. According to different requirements of the mold filling state and the cooling stage of nylon materials, the temperature of each area of the mold is dynamically adjusted, the mold temperature is properly increased in the initial mold filling stage, a cavity is rapidly filled with melt, and along with mold filling, the mold temperature is gradually reduced, and melt cooling and crystallization are accelerated. According to the temperature control forming process of the photovoltaic nylon connector mold and the composite runner, the phase change energy storage material is embedded in the fixed mold area of the mold, and the heat absorption and release characteristics of the phase change energy storage material during phase change are used for assisting temperature control, so that the problem of embrittlement or insufficient strength caused by non-uniform crystallization of a product in a traditional process is solved; and the photovoltaic connector is ensured to have good mechanical property and weather resistance in long-term use.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic connector manufacturing, and in particular to a temperature-controlled molding process and a composite flow channel of a photovoltaic nylon connector mold. Background Art

[0002] In the photovoltaic industry, photovoltaic connectors are key components for achieving electrical connections between photovoltaic modules. Their quality and performance directly impact the stability and reliability of the entire photovoltaic system. Nylon, due to its excellent mechanical properties, insulation properties, and weather resistance, is an ideal material for manufacturing photovoltaic connectors. However, existing molds for photovoltaic nylon connectors present numerous challenges during the molding process.

[0003] On the one hand, traditional mold temperature control systems are unable to accurately control the mold temperature, resulting in inconsistent crystallinity of the nylon material during the molding process, which in turn affects the mechanical properties and dimensional accuracy of the connector. For example, if the temperature is too high, the nylon material will over-crystallize and the product will become brittle; if the temperature is too low, the crystallization will be incomplete and the product will lack strength. On the other hand, traditional injection molding runners have simple structures, mostly single cold runners or hot runners. During the injection molding process, problems such as uneven plastic melt flow rate and large pressure loss are prone to occur. This not only leads to poor product molding quality, such as defects such as weld marks and bubbles, but also causes material waste and low production efficiency. In addition, existing molds lack effective process and runner designs for the molding of complex structures of photovoltaic nylon connectors, making it difficult to meet the growing production demand for high-precision, high-performance photovoltaic connectors. Summary of the Invention

[0004] The purpose of the present invention is to provide a temperature-controlled molding process and a composite flow channel for a photovoltaic nylon connector mold to solve the problems raised in the above background technology.

[0005] To achieve the above-mentioned object, the present invention provides the following technical solution: a temperature-controlled molding process for a photovoltaic nylon connector mold, comprising the following steps:

[0006] S1: The mold is divided into fixed mold, movable mold, cavity, core, and runner areas. Each area is equipped with an independent temperature control circuit. By embedding heating rods and cooling water pipes inside the mold, temperature sensors are used to monitor the temperature in real time. The intelligent temperature controller accurately adjusts the heating power and cooling water flow according to the preset temperature curve to keep the temperature of each area within the optimal molding temperature range of nylon material.

[0007] S2: During the injection molding process, the temperature of each area of ​​the mold is dynamically adjusted according to the different requirements of the filling state and cooling stage of the nylon material. The mold temperature is appropriately increased at the beginning of the filling process to promote the rapid filling of the melt into the cavity. As the filling process progresses, the mold temperature is gradually reduced to accelerate the cooling and crystallization of the melt.

[0008] S3: Introducing artificial intelligence algorithms to build a temperature prediction model based on historical production data and real-time monitoring data. This model predicts the optimal temperature required for each area of ​​the mold in real time based on multiple factors such as the type of nylon material, injection molding machine parameters, ambient temperature, and raw material batch changes. It automatically adjusts the control parameters of the intelligent temperature controller and continuously optimizes by continuously learning new production data.

[0009] S4: Embed phase change energy storage material in the fixed mold area of ​​the mold and use its heat absorption and release characteristics during phase change to assist in temperature control.

[0010] Preferably, the optimal molding temperature range of the cavity area is 80°C-120°C, the cavity temperature is set to 110°C-120°C in the initial filling stage, and the cavity temperature drops to 80°C-90°C during the cooling stage.

[0011] Preferably, positioning sleeves are fixedly connected to the four corners of the lower surface of the movable mold, and positioning columns extending into the interior of the positioning sleeves are fixedly connected to the four corners of the top of the movable mold.

[0012] Preferably, the diameter of the cooling water pipe is 8-12 mm, the spacing between adjacent cooling water pipes is 25-35 mm, and the distance between the cooling water pipe and the mold cavity surface is 15-20 mm.

[0013] Preferably, the phase change energy storage material is a paraffin-based phase change material, the phase change temperature of which is 85°C-115°C and the phase change latent heat of which is 180-220 kJ / kg.

[0014] A composite runner for a photovoltaic nylon connector mold, the runner comprising a main gate, a secondary gate, a main runner and a secondary runner, the main gate and the secondary gate both being opened on the upper surface of the runner, the main runner being fixedly connected to the bottom of the main gate, and the secondary runner being fixedly connected to the bottom of the secondary gate.

[0015] Preferably, the main gate structure is a latent gate, and the auxiliary gate structure is a hot runner needle valve gate, so as to achieve a smooth connection between the runner and the mold cavity.

[0016] Preferably, the diameter of the main runner is 10-15 mm, the diameter of the secondary runner is 6-10 mm, the diameter of the main gate is 4-6 mm, the diameter of the secondary gate is 2-3 mm, and two secondary runners are provided, which are interconnected.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1. The photovoltaic nylon connector mold utilizes a temperature-controlled molding process and composite flow channels. The cavity area utilizes an optimal molding temperature range of 80°C-120°C, with a dynamic adjustment method that sets the temperature at 110°C-120°C during the initial filling phase and drops it to 80°C-90°C during the cooling phase. This offers significant advantages over traditional fixed temperature control. The high temperature during the initial filling phase effectively reduces the viscosity of the nylon melt, enabling it to quickly and evenly fill the complex cavity structure, reducing defects caused by insufficient filling. The gradient cooling during the cooling phase provides ample time for the nylon material to crystallize, avoiding incomplete crystallization caused by rapid cooling. This addresses the embrittlement or insufficient strength issues often associated with uneven crystallization in traditional processes, ensuring the photovoltaic connector maintains excellent mechanical properties and weather resistance over long-term use.

[0019] 2. The photovoltaic nylon connector mold's temperature-controlled molding process and composite runners embed a paraffin-based phase change energy storage material with a phase change temperature of 85°C-115°C and a phase change latent heat of 180-220 kJ / kg in the mold's fixed mold area, effectively improving the mold's temperature stability. When the melt releases a large amount of heat during the filling process, causing a sudden rise in local temperature, the phase change material absorbs the heat and undergoes a phase change, preventing the cavity temperature from exceeding the optimal range. When the temperature drops too quickly during the cooling stage, the phase change material releases the stored heat, slowing the cooling rate and ensuring uniform crystallization of the nylon material. This further reduces internal stress in the product, reduces the deformation and scrap rate caused by temperature fluctuations, and improves the product's qualified rate.

[0020] 3. The photovoltaic nylon connector mold utilizes a temperature-controlled molding process and composite runners. The runner design utilizes a combination of a main gate (latent, 4-6mm diameter) and a secondary gate (hot runner needle valve, 2-3mm diameter), significantly improving melt filling and product quality. The latent main gate ensures a smooth transition between the melt and the cavity, avoiding melt turbulence at traditional gates and reducing weld marks. The hot runner needle valve secondary gate precisely controls the timing and flow of melt injection, closing promptly after mold filling is complete, effectively preventing melt backflow and overfilling, and minimizing flash defects at the gate. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0022] Figure 1 This is a schematic diagram of the front structure of the photovoltaic nylon connector mold of the present invention;

[0023] Figure 2This is a schematic diagram of the back structure of the photovoltaic nylon connector mold of the present invention;

[0024] Figure 3 Schematic diagram of the internal structure of the core of the present invention;

[0025] Figure 4 This is a schematic diagram of the top structure of the runner of the present invention;

[0026] Figure 5 It is a schematic diagram of the connection structure of the main flow channel and the secondary flow channel of the present invention.

[0027] In the figure: 1. Fixed mold; 2. Moving mold; 3. Core; 4. Runner; 401. Main gate; 402. Auxiliary gate; 403. Main runner; 404. Auxiliary runner; 5. Cavity; 6. Positioning column; 7. Heating rod; 8. Positioning sleeve; 9. Temperature sensor; 10. Cooling pipe; 11. Phase change energy storage material. DETAILED DESCRIPTION

[0028] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0029] In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connect," "fixed," etc. should be understood broadly. For example, they may refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0030] See also Figure 1-Figure 5 The present invention provides a technical solution: a temperature-controlled molding process for a photovoltaic nylon connector mold, comprising the following steps:

[0031] S1: The mold is divided into fixed mold 1, movable mold 2, cavity 5, core 3, and runner 4 areas. Each area is equipped with an independent temperature control circuit. By embedding heating rods 8 and cooling water pipes 9 inside the mold, the temperature is monitored in real time by temperature sensors 10. The intelligent temperature controller accurately adjusts the heating power and cooling water flow according to the preset temperature curve to keep the temperature of each area within the optimal molding temperature range of nylon material.

[0032] S2: During the injection molding process, the temperature of each area of ​​the mold is dynamically adjusted according to the different requirements of the filling state and cooling stage of the nylon material. The mold temperature is appropriately increased at the beginning of the filling process to promote the rapid filling of the melt into the cavity. As the filling process progresses, the mold temperature is gradually reduced to accelerate the cooling and crystallization of the melt.

[0033] S3: Introducing artificial intelligence algorithms to build a temperature prediction model based on historical production data and real-time monitoring data. This model predicts the optimal temperature required for each area of ​​the mold in real time based on multiple factors such as the type of nylon material, injection molding machine parameters, ambient temperature, and raw material batch changes. It automatically adjusts the control parameters of the intelligent temperature controller and continuously optimizes by continuously learning new production data.

[0034] S4: embedding a phase change energy storage material 11 in the fixed mold 1 area of ​​the mold, and utilizing its heat absorption and release characteristics during phase change to assist in temperature control.

[0035] The optimal molding temperature range of the cavity area is 80℃-120℃. The cavity temperature is set at 110℃-120℃ in the initial filling stage, and the cavity temperature drops to 80℃-90℃ during the cooling stage.

[0036] Positioning sleeves 7 are fixedly attached to the four corners of the lower surface of the movable mold 2. Positioning posts 6, extending into the interior of these sleeves, are fixedly attached to the four corners of the top of the movable mold 2. These posts ensure precise closing of the movable mold 2 with the positioning sleeves 7 of the fixed mold 1, with a clearance of ≤0.02mm. The ejection mechanism is activated with a delay of 2 seconds after the pressure hold period ends, and the ejection speed is set to 15mm / s to prevent product deformation due to internal stress.

[0037] The diameter of the cooling water pipe 9 is 8-12 mm, the spacing between adjacent cooling water pipes is 25-35 mm, and the distance between the cooling water pipe 9 and the surface of the mold cavity 5 is 15-20 mm.

[0038] The phase change energy storage material 11 is a paraffin-based phase change material with a phase change temperature of 85° C.-115° C. and a phase change latent heat of 180-220 kJ / kg.

[0039] The cooling water pipes 9 are spiral structures with a diameter of 10 mm, with 30 mm spacing between adjacent pipes and 18 mm from the surface of the cavity 5. The heating rods 8 are set to 500 W and evenly distributed over the core 3 and runner 4 areas. Temperature sensors 10 achieve temperature control with an accuracy of ±1°C.

[0040] The optimal molding temperature of cavity 5 is set at 100°C, which is raised to 115°C at the initial filling stage and dropped to 85°C during the cooling stage. The temperature of core 3 is maintained at 90°C ± 2°C. The temperature of runner 4 is maintained at 120°C to ensure melt fluidity.

[0041] Historical production data was imported, including 5,000 molding records of nylon 66 material. The model input parameters included melt temperature (250-270°C), injection speed (30-50mm / s), and ambient temperature (20-30°C). The output target was the temperature adjustment coefficient of each area. After three rounds of iteration, the model prediction error was controlled within ±2°C.

[0042] A composite runner for a photovoltaic nylon connector mold, wherein the runner 4 includes a main gate 401, an auxiliary gate 402, a main runner 403 and an auxiliary runner 404. The main gate 401 and the auxiliary gate 402 are both opened on the upper surface of the runner 4, the main runner 403 is fixedly connected to the bottom of the main gate 401, and the auxiliary runner 404 is fixedly connected to the bottom of the auxiliary gate 402. The main gate 401 is a latent gate, and the auxiliary gate 402 is a hot runner needle valve gate, so as to achieve a smooth connection between the runner 4 and the mold cavity 5.

[0043] The diameter of the main runner 403 is 10-15 mm, the diameter of the secondary runner 404 is 6-10 mm, the diameter of the main gate 401 is 4-6 mm, the diameter of the secondary gate 402 is 2-3 mm, and there are two secondary runners 404, which are interconnected.

[0044] After drying at 80°C for 4 hours, the nylon raw material is injected through the injection molding machine at a melt temperature of 260°C, an initial injection speed of 40 mm / s, and a holding pressure of 80 MPa. During the filling phase, the AI ​​system automatically fine-tunes the runner temperature from 120°C to 118°C based on the real-time monitored cavity pressure (120-150 bar) to prevent excessive melt shearing. During the cooling phase, the phase change material releases heat, and the cooling water pipes control the cavity cooling rate to 5°C / s to ensure uniform crystallization.

[0045] Working principle: The movable mold 2 is precisely matched with the positioning sleeve 7 on the lower surface of the fixed mold 1 through the positioning columns 6 at the four corners of the top, and the positioning gap is ≤0.02mm, ensuring that the cavity 5 and the core 3 are completely aligned. The mold clamping mechanism drives the movable mold 2 to move toward the fixed mold 1 until the mold is closed. The clamping force is set to 1500-2000kN to prevent the melt pressure from causing the mold parting surface to expand during the injection process. After the mold is closed, the independent temperature control circuit of each area is started, and the cavity 5 area is preheated to 80-120℃ (initial setting 100℃) by the heating rod 8; the runner 4 area is heated to 120℃ to ensure that the residual melt in the runner remains in a molten state; the paraffin-based phase change energy storage material 11 in the fixed mold 1 gradually accumulates heat as the temperature rises, providing a buffer for subsequent temperature stabilization.

[0046] The dried nylon raw material (water content ≤ 0.05%) is heated to 250-270°C in the barrel of the injection molding machine and melted. It is injected into the runner at a speed of 30-50 mm / s through the main gate 401. The main runner 403 (diameter 10-15 mm) adopts a hot runner design and maintains the melt temperature through external heating to reduce pressure loss. The melt is diverted to two secondary runners 404 (diameter 6-10 mm) through the main runner 403. The section of the secondary runner close to the secondary gate 402 is a cold runner. The melt temperature is reduced to 230-240°C to avoid spraying at the gate. The main gate 401 and the secondary gate 402 realize a smooth transition between the melt and the cavity (5). The angle between the two secondary runners is 45°, ensuring that the melt evenly fills the two symmetrical cavities.

[0047] The temperature sensor 10 collects temperature data of the cavity 5, core 3, and runner in real time and transmits it to the AI ​​temperature prediction model. In the early stage of mold filling, the model automatically increases the cavity temperature to 110-120°C according to the melt filling speed, reducing the melt viscosity to accelerate filling.

[0048] When the cavity pressure reaches 120-150 bar, the model starts the cooling program and controls the cooling water pipe 9 to flow 20°C cooling water, so that the cavity temperature drops to 80-90°C at a rate of 5°C / s; if differences in raw material batches are detected, such as melt index fluctuations of ±0.2g / 10min, the model adjusts the heating power within 1s to ensure that the crystallinity remains stable at 45-50%.

[0049] After mold filling is completed, the injection molding machine maintains a holding pressure of 80-100 MPa for 10-15 seconds, and the needle valve of the auxiliary gate 402 remains open to offset the volume shrinkage in the cavity 5 through melt shrinkage compensation; the AI ​​system dynamically adjusts the holding pressure according to the cavity pressure decay rate (≤5 bar / s) to avoid surface depression of the product.

[0050] The cooling water pipe 9 is 15-20mm away from the cavity surface. Uniform heat dissipation is achieved through a spiral layout. The cooling water flow rate is automatically adjusted with temperature changes (5-10L / min). The phase change energy storage material 11 releases the stored heat when the cavity temperature drops rapidly. The phase change latent heat is 180-220kJ / kg, which slows down the cooling rate and makes the nylon crystal grow more uniformly. When cooled to below 80°C, the temperature of the core 3 is maintained at 90°C±2°C to avoid internal stress cracking of the product due to temperature difference.

[0051] After cooling is completed, the total cooling time is 20-25s, the clamping mechanism is unlocked, the movable mold 2 retreats at a speed of 20mm / s, the positioning column 6 is separated from the positioning sleeve 7, the needle valve of the auxiliary gate 402 is closed, and the connection between the runner and the product is cut off. The latent main gate 401 is automatically separated from the product during the mold opening process to avoid manual trimming of the gate marks.

[0052] The ejection mechanism pushes the core 3 to eject the product from the cavity 5 at a speed of 5 mm / s to ensure that the product is not deformed. After the product is removed, the movable mold 2 is reset, the positioning pin 6 is reinserted into the positioning sleeve 7, and the mold enters the next cycle. The entire molding cycle is controlled within 45-50 seconds.

[0053] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a..." does not exclude the presence of additional identical elements in the process, method, article, or device comprising the element.

[0054] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A temperature-controlled molding process for a photovoltaic nylon connector mold, characterized in that: The following steps are involved: S1: The mold is divided into a fixed mold (1), a movable mold (2), a cavity (5), a core (3) and a runner (4). Each area is provided with an independent temperature control circuit. A heating rod (8) and a cooling water pipe (9) are embedded in the mold, and a temperature sensor (10) is used to monitor the temperature in real time. The intelligent temperature controller accurately adjusts the heating power and the cooling water flow according to the preset temperature curve to keep the temperature of each area within the optimal molding temperature range of the nylon material. S2: During the injection molding process, the temperature of each area of ​​the mold is dynamically adjusted according to the different requirements of the filling state and cooling stage of the nylon material. The mold temperature is appropriately increased at the beginning of the filling process to promote the rapid filling of the melt into the cavity. As the filling process progresses, the mold temperature is gradually reduced to accelerate the cooling and crystallization of the melt. S3: Introducing artificial intelligence algorithms to build a temperature prediction model based on historical production data and real-time monitoring data. This model predicts the optimal temperature required for each area of ​​the mold in real time based on multiple factors such as the type of nylon material, injection molding machine parameters, ambient temperature, and raw material batch changes. It automatically adjusts the control parameters of the intelligent temperature controller and continuously optimizes by continuously learning new production data. S4: embedding a phase change energy storage material (11) in the fixed mold (1) area of ​​the mold, and utilizing its heat absorption and release characteristics during phase change to assist in temperature control.

2. The temperature-controlled molding process for a photovoltaic nylon connector mold according to claim 1, characterized in that: The optimal molding temperature range of the cavity area is 80°C-120°C, the cavity temperature is set to 110°C-120°C in the initial filling stage, and the cavity temperature drops to 80°C-90°C during the cooling stage.

3. The temperature-controlled molding process for a photovoltaic nylon connector mold according to claim 1, characterized in that: Positioning sleeves (7) are fixedly connected at the four corners of the lower surface of the movable mold (2), and positioning columns (6) extending into the interior of the positioning sleeves (7) are fixedly connected at the four corners of the top of the movable mold (2).

4. The temperature-controlled molding process for a photovoltaic nylon connector mold according to claim 1, characterized in that: The diameter of the cooling water pipe (9) is 8-12 mm, the spacing between adjacent cooling water pipes is 25-35 mm, and the distance between the cooling water pipe (9) and the surface of the mold cavity (5) is 15-20 mm.

5. The temperature-controlled molding process for a photovoltaic nylon connector mold according to claim 1, characterized in that: The phase change energy storage material (11) is a paraffin-based phase change material with a phase change temperature of 85°C-115°C and a phase change latent heat of 180-220 kJ / kg.

6. The composite flow channel of a photovoltaic nylon connector mold according to any one of claims 1 to 5, characterized in that: The runner (4) comprises a main gate (401), an auxiliary gate (402), a main runner (403) and an auxiliary runner (404); the main gate (401) and the auxiliary gate (402) are both opened on the upper surface of the runner (4); the main runner (403) is fixedly connected to the bottom of the main gate (401); and the auxiliary runner (404) is fixedly connected to the bottom of the auxiliary gate (402).

7. The composite flow channel of a photovoltaic nylon connector mold according to claim 6, characterized in that: The main gate (401) is a latent gate, and the auxiliary gate (402) is a hot runner needle valve gate, so as to achieve a smooth connection between the runner (4) and the mold cavity (5).

8. The composite flow channel of a photovoltaic nylon connector mold according to claim 6, characterized in that: The diameter of the main runner (403) is 10-15 mm, the diameter of the secondary runner (404) is 6-10 mm, the diameter of the main gate (401) is 4-6 mm, the diameter of the secondary gate (402) is 2-3 mm, and two secondary runners (404) are provided, and the two secondary runners (404) are connected to each other.

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