Injection molding process capable of realizing on-line automatic mold change

Abstract

The invention discloses an on-line automatic mold changing injection molding process which comprises the following steps: S1, mold pre-storage and recognition: presetting a mold storage station beside an injection molding machine, and performing model recognition and key parameter acquisition on a target new mold through a mold recognition unit, the key parameters at least comprise a mold cavity size, a mold locking force adaptive value and a sprue position parameter; manual carrying, positioning and fixing operation is not needed in the whole process from automatic mold identification in the step S1, automatic old mold disassembly and removal in the step S2 to automatic new mold conveying, positioning and installation in the step S3. According to traditional manual die changing, operators need to manually align the dies and tighten die locking bolts, the die changing time of a single set of dies generally needs 30-60 minutes, and according to the technology, through cooperation of a mechanical carrying unit (such as a multi-axis mechanical arm) and an automatic die locking mechanism and control of a guide rail displacement sensor on the position precision within + / -0.1 mm, the die changing time can be shortened to be within 10 minutes.

Description

Technical Field

[0001] This invention relates to the field of injection molding technology, specifically an online automatic mold changing injection molding process. Background Technology

[0002] Traditional manual mold changing requires 2-3 skilled workers to operate in tandem. First, a crane or forklift is used to move the mold, weighing hundreds of kilograms, then the mold is manually aligned with the injection molding machine template, and finally, the locking bolts are tightened manually. This process is time-consuming, and manual positioning accuracy is poor, easily leading to improper mold closure due to mold misalignment, resulting in quality problems such as flash and dimensional errors in the product. While some semi-automated mold changing systems introduce mechanical handling equipment, manual intervention is still required for mold identification, parameter setting, and maintenance. For example, manual scanning of mold barcodes to input parameters and manual adjustment of key parameters such as injection molding machine barrel temperature and injection pressure are necessary. This not only depends on worker skill but is also prone to process instability due to human error. Therefore, those skilled in the art have proposed an online automatic mold changing injection molding process to solve the problems mentioned in the background. Summary of the Invention

[0003] The purpose of this invention is to provide an online automatic mold changing injection molding process. By changing the mold online automatically, labor costs can be reduced, and by using automated equipment, the uncertainty caused by manual operation can be reduced.

[0004] To achieve the above objectives, the present invention provides the following technical solution:

[0005] An online automatic mold changing injection molding process, characterized by comprising the following steps: S1: Mold Pre-storage and Identification: A mold storage station is preset next to the injection molding machine. The target new mold is identified and key parameters are collected by the mold identification unit. The key parameters include at least the mold cavity size, clamping force adaptation value, and gate position parameters. S2: Automatic disassembly and removal of old mold: After the injection molding machine completes the current batch of injection and opens the mold, the automatic mold locking mechanism unlocks the connection between the old mold and the injection molding machine template. The mechanical handling unit extends into the mold closing area of ​​the injection molding machine, grabs the old mold and transports it along the preset guide rail to the old mold temporary storage area of ​​the mold storage station. S3: Automatic conveying and positioning installation of new mold: The mechanical handling unit picks up the identified target new mold from the mold storage station and conveys it to the mold closing area of ​​the injection molding machine along the guide rail. The new mold is coaxially positioned with the moving and fixed mold plates of the injection molding machine by the mold guiding and positioning components. Then the automatic mold locking mechanism drives the mold locking bolts to tighten, thus fixing the new mold to the mold plates. S4: Automatic matching of process parameters: The injection molding machine control system automatically retrieves the corresponding injection parameters from the preset process parameter library based on the key parameters of the new mold collected in step S1. The injection parameters include at least the temperature of each section of the barrel, injection pressure, injection speed, holding time, and cooling time. The parameter calibration unit fine-tunes the parameters based on the real-time temperature fed back by the mold temperature sensor. S5: Trial production verification and mass production: The injection molding machine performs trial injection according to the matched process parameters. The product inspection unit inspects the dimensional accuracy and appearance defects of the trial injection products. If the inspection is qualified, it enters mass injection production; if the inspection is unqualified, it returns to step S4 to readjust the parameters. S6: Automatic Maintenance of Old Molds: The maintenance unit located in the old mold temporary storage area automatically cleans the old molds, sprays mold release agent on the cavities, and performs wear detection. After completing the maintenance, the old molds are transferred to the waiting area of ​​the mold storage station for use in the next mold change. Furthermore, in step S1, the mold identification unit is an RFID identification module or a visual recognition camera; if it is an RFID identification module, it obtains key parameters by reading the electronic tag embedded on the surface of the target new mold; if it is a visual recognition camera, it completes identification and parameter acquisition by comparing the appearance features of the new mold with a preset mold parameter database. Furthermore, in steps S2 and S3, the mechanical handling unit is a multi-axis robotic arm, and the end of the robotic arm is equipped with an adaptive clamp. The adaptive clamp can automatically adjust the clamping force according to the weight and shape of the mold, and the guide rail is equipped with a displacement sensor to monitor the positional accuracy of the robotic arm in handling the mold in real time.

[0006] Furthermore, in step S3, the mold guiding and positioning assembly includes a positioning pin set on the injection molding machine template and a positioning hole on the new mold. After positioning is completed, the pressure sensor detects the bonding pressure between the new mold and the template to ensure that the bonding pressure is uniform and reaches the preset pressure value. Furthermore, in step S4, the parameter calibration unit includes a mold cavity temperature sensor. When the real-time temperature of the mold cavity deviates from the preset temperature by more than ±2℃, the control system automatically adjusts the power of the mold heating tube. Furthermore, in step S5, the product inspection unit includes a laser size measuring instrument and a visual defect detector. The laser size measuring instrument has an inspection accuracy of ≤0.005mm for key dimensions of the product, and the visual defect detector can identify defects such as surface scratches and missing materials of ≥0.1mm. The inspection results are automatically generated as qualified / unqualified signals by the control system. Furthermore, in step S6, the maintenance unit includes a high-pressure air blowing assembly, a mold release agent spraying assembly, and an ultrasonic flaw detector; the high-pressure air blowing assembly cleans the mold cavity and guide pillars with compressed air; the mold release agent spraying assembly evenly sprays the mold release agent according to a preset spraying path; and the ultrasonic flaw detector performs wear detection on the surface of the mold cavity, issuing a maintenance warning signal when the wear depth exceeds 0.02mm.

[0007] By adopting the above technical solution Compared with the prior art, the beneficial effects of the present invention are: 1. From the automatic mold identification in step S1, the automatic disassembly and removal of the old mold in step S2, to the automatic delivery, positioning, and installation of the new mold in step S3, the entire process requires no manual handling, positioning, or fixing. Traditional manual mold changing requires operators to manually align the mold and tighten the locking bolts, and the mold changing time for a single set of molds usually takes 30-60 minutes. However, this process, through the collaboration of mechanical handling units (such as multi-axis robotic arms) and automatic mold locking mechanisms, combined with the control of positional accuracy within ±0.1mm by guide rail displacement sensors, can shorten the mold changing time to less than 10 minutes, reduce downtime by more than 60%, and effectively improve the utilization rate of injection molding machine equipment. 2. While the new mold is undergoing S4 process parameter matching and S5 trial production verification, the old mold can be cleaned, coated with release agent and tested for wear through the S6 automatic maintenance unit. There is no need to wait for the new mold to stabilize before processing the old mold, which enables parallel operation of mold replacement and mold maintenance, further reducing production gaps and improving the overall production cycle time. 3. Step S1: Accurately collect key parameters of the new mold (cavity dimensions, clamping force adaptation value, etc.) through RFID identification module or visual recognition camera. In S4, the injection molding machine control system automatically retrieves data from the process parameter library based on these parameters, avoiding deviations caused by manual parameter setting based on experience. At the same time, the parameter calibration unit monitors the temperature in real time through the mold cavity temperature sensor. When the deviation exceeds ±2℃, it automatically adjusts the heating tube power to ensure that core parameters such as barrel temperature and injection pressure are always in the optimal range, reducing the product defect rate caused by parameter fluctuations. 4. Traditional mold changing requires 2-3 skilled workers to operate together, and the skill level of the workers is required to be high; this process is fully automated and only requires 1 operator to monitor the system, which can reduce the manual input by more than 50% and reduce the dependence on the operator's skills. Attached Figure Description

[0008] Figure 1 This is a schematic diagram of an online automatic mold changing injection molding process; Detailed Implementation To make the technical means, creative features, objectives, and effects of this invention easier to understand, the invention is further described below in conjunction with specific embodiments. In the description of this invention, it should be noted that the terms "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "one end," and "the other end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention and simplifying the description. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0009] Please see Figure 1 This invention provides an embodiment of an online automatic mold changing injection molding process, comprising the following steps: Step 1: Mold Pre-storage and Identification Place the target new mold (model: YM-2024-01) on the mold rack in the new mold storage area on the left. Embed an RFID electronic tag on the surface of the new mold (storing key parameters such as mold model, cavity size, clamping force adaptation value, etc.). Activate the RFID identification module, which reads the electronic tag information via wireless radio frequency signal. The reading time is ≤1 second. After reading, the identification data is automatically transmitted to the injection molding machine control system. The control system displays "New mold identification completed, parameters matched" on the screen. If the RFID identification module malfunctions, it automatically switches to the vision recognition camera. The camera captures the appearance of the new mold (focusing on the mold model identification and cavity outline). The image is compared with the preset mold parameter database using an image algorithm. Identification and parameter acquisition are completed within 5 seconds, ensuring error-free acquisition of key parameters of the new mold and laying the foundation for automatic matching of subsequent process parameters. Step 2: Automatic disassembly and removal of the old mold After the injection molding machine completes the production of the previous batch of automotive door panel parts, the injection molding machine automatically opens the mold. The control system sends an "unlock command" to the automatic mold locking mechanism. The electric mold locking bolts rotate in reverse order (from top and bottom to left and right) according to a preset sequence. After unlocking, the mechanism sends a "old mold unlocked successfully" signal. The multi-axis robotic arm receives the "transfer old mold" command and moves along the guide rail to the mold closing area of ​​the injection molding machine. The adaptive clamp at the end of the robotic arm extends into the lifting eye holes on both sides of the old mold. After clamping, the displacement sensor monitors the position of the robotic arm in real time to ensure that the coaxiality deviation between the clamp and the lifting eye holes of the old mold is ≤0.05mm. Then, the robotic arm slowly moves the old mold out of the mold closing area along the guide rail and finally transports the old mold to the old mold temporary storage area on the right. The entire old mold disassembly and removal process takes 2 minutes, which is significantly more efficient than traditional manual disassembly (which requires 2 workers and takes 15 minutes). Step 3: Automatic conveying and positioning installation of the new mold After the robotic arm completes the transport of the old mold, it does not need to return to the initial position. It moves directly along the guide rail to the new mold storage area on the left, grabs the target new mold with the adaptive gripper, and transports it along the guide rail to the mold closing area of ​​the injection molding machine. The displacement sensor corrects the position in real time to ensure the coaxiality of the new mold and the mold closing area. When the new mold is delivered to the mold closing area, the moving mold platen of the injection molding machine moves slowly, achieving coaxial positioning between the new mold and the mold platen through the mold guiding and positioning components. After positioning, the moving mold platen continues to apply pressure, and the pressure sensor on the mold platen (model: HBM U9C) detects the contact pressure between the new mold and the mold platen. When the pressure reaches 500N and the pressure deviation at each point is ≤50N, a "contact qualified" signal is fed back. The control system then sends a "mold locking command" to the automatic mold locking mechanism, and the 8 sets of electric mold locking bolts rotate clockwise, with the torque gradually increasing to 180N. The mold clamping time is 20 seconds, and the new mold and template are fixed. The entire process of conveying and positioning the new mold takes 2.5 minutes. The total time for changing a single mold (removing the old mold + installing the new mold) is only 4.5 minutes, which is much lower than the 30-60 minutes of traditional manual mold changing. Downtime is reduced by 85%, and the utilization rate of injection molding machine equipment is significantly improved (from the traditional 60% to more than 85%). Step 4: Automatic matching of process parameters After the new mold is installed, the control system automatically retrieves the corresponding injection parameters from the process parameter library based on the key parameters of the new mold (cavity size, clamping force adaptation value, etc.) collected in step 1. The retrieval time is ≤2s, and the parameters are displayed on the control system screen, eliminating the need for manual input by the operator. Subsequently, the parameter calibration unit is activated, and the mold cavity temperature sensor (model: thermocouple K type, accuracy ±0.5℃) collects the cavity temperature in real time. The initial temperature is 65℃, which is lower than the preset value of 80℃. The control system automatically adjusts the power of the mold heating tube from 0kW to 3kW. After heating for 10 minutes, the cavity temperature reaches 80℃, and the temperature sensor feeds back a "temperature qualified" signal. If the ambient temperature fluctuates during production, causing the cavity temperature to rise to 83℃ (exceeding the ±2℃ threshold), the control system immediately reduces the heating tube power to 2kW, and the temperature drops back to 80℃ within 5 minutes, ensuring that core parameters such as barrel temperature and injection pressure are always within the optimal range, avoiding deviations caused by manual adjustment of parameters based on experience. Step 5: Trial production verification and mass production The injection molding machine performs trial injections according to the matched process parameters, with 5 pieces made. After the trial injections are completed, the robotic arm transports the test pieces to the product inspection unit. A laser dimension measuring instrument (model: Renishaw XL-80) inspects the key dimensions of the test pieces, and the inspection results show that the dimensional deviations are all within ±0.1mm. A visual defect detector (model: Keyence IV2 series) scans the surface of the test pieces and can identify tiny scratches as small as 0.08mm. All 5 test pieces are free of defects such as scratches and missing material. The inspection unit automatically generates a "qualified" signal, and the injection molding machine then enters mass production. Step 6: Automatic Maintenance of Old Mold While the new mold is undergoing step 4 (parameter matching) and step 5 (trial production verification), the maintenance unit in the old mold storage area is activated: First, the high-pressure air blowing assembly (pressure 1.0MPa, flow rate 0.8m³ / min) cleans the old mold cavity and guide pillars through the nozzle for 3 minutes, removing residual plastic residue and oil from the cavity; then, the mold release agent spray assembly (model: SMC AVM200) sprays the mold release agent (model: Kentian KL-200) along the preset spraying path (from the inside to the outside of the cavity contour) for 2 minutes; finally, the ultrasonic flaw detector (model: Olympus EPOCH 650) performs wear detection on the surface of the old mold cavity. When the local wear depth of the cavity is detected to be 0.015mm (less than the 0.02mm warning threshold), it is determined that "maintenance is qualified". The robotic arm transfers the maintained old mold to the waiting area of ​​the new mold storage area, and the parameter matching and trial production verification of the new mold are carried out in parallel, without waiting for the new mold to be mass-produced and stabilized before processing the old mold.

[0010] From the automatic mold identification in step S1, the automatic disassembly and removal of the old mold in step S2, to the automatic delivery, positioning and installation of the new mold in step S3, the entire process requires no manual handling, positioning and fixing operations. Traditional manual mold changing requires operators to manually align the mold and tighten the locking bolts, with a single mold change typically taking 30-60 minutes. This new process, through the collaboration of mechanical handling units (such as multi-axis robotic arms) and automatic mold-locking mechanisms, combined with guide rail displacement sensors for positional accuracy within ±0.1mm, can reduce mold change time to less than 10 minutes, reducing downtime by over 60% and effectively improving injection molding machine utilization. While the new mold undergoes S4 process parameter matching and S5 trial production verification, the old mold can be cleaned, coated with release agent, and worn using the S6 automatic maintenance unit. This eliminates the need to wait for the new mold to stabilize before processing the old mold, enabling parallel mold changing and maintenance operations, further reducing production gaps and improving overall production cycle time. Step S1 uses an RFID identification module or visual recognition camera to accurately collect key parameters of the new mold (cavity dimensions, clamping force adaptation value, etc.), S4... The injection molding machine control system automatically retrieves process parameter data based on this parameter, avoiding deviations caused by manual parameter setting based on experience. At the same time, the parameter calibration unit monitors the temperature in real time through the mold cavity temperature sensor. When the deviation exceeds ±2℃, it automatically adjusts the heating tube power to ensure that core parameters such as barrel temperature and injection pressure are always within the optimal range, reducing the product defect rate caused by parameter fluctuations. Traditional mold changing requires 2-3 skilled workers to operate together, and the skill level of the workers is highly required. This process is fully automated, requiring only 1 operator to monitor the system, which can reduce manual input by more than 50% and reduce reliance on the operator's skills.

[0011] This specification describes embodiments, but not every embodiment contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An online automatic mold changing injection molding process, characterized in that, Includes the following steps: S1: Mold Pre-storage and Identification: A mold storage station is preset next to the injection molding machine. The target new mold is identified and key parameters are collected by the mold identification unit. The key parameters include at least the mold cavity size, clamping force adaptation value, and gate position parameters. S2: Automatic disassembly and removal of old mold: After the injection molding machine completes the current batch of injection and opens the mold, the automatic mold locking mechanism unlocks the connection between the old mold and the injection molding machine template. The mechanical handling unit extends into the mold closing area of ​​the injection molding machine, grabs the old mold and transports it along the preset guide rail to the old mold temporary storage area of ​​the mold storage station. S3: Automatic conveying and positioning installation of new mold: The mechanical handling unit picks up the identified target new mold from the mold storage station and conveys it to the mold closing area of ​​the injection molding machine along the guide rail. The new mold is coaxially positioned with the moving and fixed mold plates of the injection molding machine by the mold guiding and positioning components. Then the automatic mold locking mechanism drives the mold locking bolts to tighten, thus fixing the new mold to the mold plates. S4: Automatic matching of process parameters: The injection molding machine control system automatically retrieves the corresponding injection parameters from the preset process parameter library based on the key parameters of the new mold collected in step S1. The injection parameters include at least the temperature of each section of the barrel, injection pressure, injection speed, holding time, and cooling time. The parameter calibration unit fine-tunes the parameters based on the real-time temperature fed back by the mold temperature sensor. S5: Trial production verification and mass production: The injection molding machine performs trial injection according to the matched process parameters. The product inspection unit inspects the dimensional accuracy and appearance defects of the trial injection products. If the inspection is qualified, it enters mass injection production; if the inspection is unqualified, it returns to step S4 to readjust the parameters. S6: Automatic Maintenance of Old Molds: The maintenance unit located in the old mold temporary storage area automatically cleans the old molds, sprays mold release agent on the cavities, and performs wear detection. After completing the maintenance, the old molds are transferred to the waiting area of ​​the mold storage station for use in the next mold change.

2. The online automatic mold changing injection molding process according to claim 1, characterized in that, In step S1, the mold identification unit is either an RFID identification module or a visual recognition camera. If it is an RFID identification module, it obtains key parameters by reading the electronic tag embedded on the surface of the target new mold. If it is a visual recognition camera, it completes identification and parameter acquisition by comparing the appearance features of the new mold with a preset mold parameter database.

3. The online automatic mold changing injection molding process according to claim 1, characterized in that, In steps S2 and S3, the mechanical handling unit is a multi-axis robotic arm. The end of the robotic arm is equipped with an adaptive clamp. The adaptive clamp can automatically adjust the clamping force according to the weight and shape of the mold. The guide rail is equipped with a displacement sensor to monitor the positional accuracy of the robotic arm in handling the mold in real time.

4. The online automatic mold changing injection molding process according to claim 1, characterized in that, In step S3, the mold guiding and positioning component includes a positioning pin on the injection molding machine template and a positioning hole on the new mold. After positioning is completed, the pressure sensor detects the bonding pressure between the new mold and the template to ensure that the bonding pressure is uniform and reaches the preset pressure value.

5. The online automatic mold changing injection molding process according to claim 1, characterized in that, In step S4, the parameter calibration unit includes a mold cavity temperature sensor. When the real-time temperature of the mold cavity deviates from the preset temperature by more than ±2℃, the control system automatically adjusts the power of the mold heating tube.

6. The online automatic mold changing injection molding process according to claim 1, characterized in that, In step S5, the product inspection unit includes a laser size measuring instrument and a visual defect detector. The laser size measuring instrument has an inspection accuracy of ≤0.005mm for key dimensions of the product, and the visual defect detector can identify defects such as surface scratches and missing materials of ≥0.1mm. The inspection results are automatically generated as qualified / unqualified signals by the control system.

7. The online automatic mold changing injection molding process according to claim 1, characterized in that, In step S6, the maintenance unit includes a high-pressure air blowing assembly, a mold release agent spraying assembly, and an ultrasonic flaw detector; the high-pressure air blowing assembly cleans the mold cavity and guide pillars with compressed air; the mold release agent spraying assembly evenly sprays the mold release agent according to a preset spraying path; the ultrasonic flaw detector performs wear detection on the surface of the mold cavity, and issues a maintenance warning signal when the wear depth exceeds 0.02mm.

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