CN106863731A - A kind of injection-molded item defect self-cure regulation and control device and method - Google Patents

Abstract

The invention discloses a defect self-healing control device and method for injection molding products. The device mainly includes a PT monitoring device, a product forming defect evaluation and judgment module, and a mold auxiliary pressure regulation module. The PT monitoring device is installed in the mold clamping system of an injection molding machine. The monitoring device is composed of a pressure sensor, a temperature sensor and a data acquisition module, which can monitor the pressure P and temperature T in the mold cavity of each product during the molding process. The data acquisition module is connected to the interface of the product molding defect evaluation and judgment module, and the collected The data is input into the product molding defect evaluation and judgment module; the product molding defect evaluation and judgment module compares the molding process path of each product with the standard molding process path, and then inputs the comparison result into the mold auxiliary pressure regulation module; the mold auxiliary The mold-assisted pressure-regulating controller of the pressure-regulating module regulates the pressure in the mold cavity in real time according to the comparison results, and the separate structure of plasticization and injection can ensure higher precision control of the pressure in the mold cavity.

Description

A self-healing control device and method for injection molded product defects

technical field

The invention relates to the field of polymer material processing, in particular to a device and method for self-healing control of defects in large-scale injection molding products based on polymer PVT characteristic curves.

technical background

Injection molding refers to the molding method of injecting molten material into the mold cavity, and then cooling and solidifying to obtain products. It is especially suitable for processing products with complex shapes, precise dimensions and inserts. Injection molding is an excellent processing method for low-cost, high-volume production of plastic products, and it is also an indispensable processing method for the development of high-tech products. my country has become the world's largest producer of injection molding machines, but it is still far behind the world's advanced level in terms of high-end products. With the rapid development of industries such as aerospace, automobile industry, consumer electronics and home appliances, injection molding processing is facing urgent requirements for intelligent manufacturing and further improvement of equipment efficiency, precision and energy saving effect. In order to achieve high-precision, high-efficiency continuous production of injection molding products, it is necessary to proceed from the characteristics of polymer molding processing, so that the injection molding equipment has the functions of automatic process monitoring, online diagnosis of molding defects, and self-healing regulation. The research and development has independent High-end intelligent precision injection molding equipment with intellectual property rights will further enhance the international competitiveness of domestic injection molding equipment.

Injection molding process is a highly nonlinear, time-varying multi-parameter process. Since this process has the characteristics of multiple parameters interacting and changing with time, each parameter has a different degree of influence on the quality of the final part. Studies have shown that the specific volume V of the polymer and the pressure P and temperature T of the melt during processing always follow a specific relationship, that is, V=f(P,T), which is the basic property of the material and also the molded product. The scientific basis for precision control. Since changes in the specific volume V will cause changes in the quality and shape of the molded product, the PVT characteristic relationship and its evolution during the molding process are the key to the dimensional accuracy and quality control of injection molded products. The essence of injection molding precision control is to accurately grasp the PVT relationship characteristics of the polymer, and to achieve precise control of the specific volume V that determines the dimensional accuracy and physical and mechanical properties of the final molded product.

At present, in actual production, the feedback of product defects is through statistical quality control, that is, workers periodically check product quality and report to operators to consider the current machine performance, and defect control is through operators who rely on experience to stop and readjust process parameters. Therefore, in order to improve the production performance of injection molding and produce higher quality products, better monitoring and control of the molding process is required. The invention can monitor the pressure P and temperature T in the mold cavity during the molding process of each product, draw the molding process path of each product according to the PVT characteristic curve of the material, and compare it with the standard molding process path to determine the product Whether there is a defect, the mold auxiliary pressure regulation module can adjust the pressure in the mold cavity in real time according to the comparison result, and realize the online monitoring and self-healing regulation of the defect of the injection molded product. The invention enables the existing injection molding equipment to have an online self-healing function for molding defects, and can perform online self-repair for injection molding defects without human intervention, thereby realizing intelligent, efficient and continuous production and processing.

Contents of the invention

The purpose of the present invention is to design a defect self-healing control system for injection molding products in view of the shortcomings of the existing technology, real-time monitoring of injection molding process parameters, and intelligent control, and finally achieve product appearance, dimensional accuracy and weight repeatability accuracy Precision control.

The technical solution of the present invention is: a defect self-healing control device for injection molding products, which mainly includes a PT monitoring device, a product forming defect evaluation and judgment module, and a mold auxiliary pressure regulation module. The PT monitoring device is installed in the mold clamping system of the injection molding machine Among them, the monitoring device is composed of a pressure sensor, a temperature sensor and a data acquisition module, which can monitor the pressure P and temperature T in the mold cavity of each product during the molding process. The data acquisition module is connected to the interface of the product molding defect evaluation and judgment module. The collected data is input into the product molding defect evaluation and judgment module; the product molding defect evaluation and judgment module compares the molding process path of each product with the standard molding process path, and then inputs the comparison result into the mold auxiliary pressure regulation module The mold auxiliary pressure regulating module includes a mold auxiliary pressure regulating controller, a mold auxiliary pressure regulating plasticizing system and a mold auxiliary pressure regulating injection system. , Screw 1, barrel heating ring 1 and plasticizing servo motor. The mold auxiliary pressure regulating injection system can be a plunger type injection system, which consists of a melt barrel, a plunger, an injection cylinder, and a mold auxiliary pressure regulating module. The pressure regulating controller adjusts the pressure in the mold cavity in real time according to the comparison result to ensure the accuracy of the product. The separate structure of plasticization and injection can ensure higher precision control of the pressure in the mold cavity.

The invention relates to a defect self-healing control device for injection molding products, which is applied to the self-healing control of injection molding product defects. Its application method mainly includes the following steps: use the polymer PVT tester to obtain the PVT characteristic curve of the polymer; the molding process of each product can be divided into four stages: plasticization, injection, pressure holding, and cooling. Based on the polymer PVT characteristic curve and the relative change relationship between P and T, a curve can be drawn as the molding process path of the product, and the molding process path of the standard product that meets the requirements can be recorded as the standard molding process path of this type of product. At the same time, during the molding process of each product, after the main injection system completes plasticization and injection, the PT monitoring device monitors the pressure P and temperature T changes in the mold cavity during the pressure holding and cooling process, and collects The data of the product is input into the product molding defect evaluation and judgment module; the product molding defect evaluation and judgment module compares the P corresponding to a certain stage T of each product in the molding process with the pressure value on the corresponding standard molding process path, and then Input the comparison result into the mold auxiliary pressure regulation module; the mold auxiliary pressure regulation controller in the mold auxiliary pressure regulation module controls the work of the mold auxiliary pressure regulation plasticizing system and the mold auxiliary pressure regulation injection system according to the comparison result, so that a The P corresponding to the first stage T is always consistent with the pressure value on the corresponding standard molding process path, so that the molding process path of each product in the injection process can be repeated with the standard molding process path with high precision, realizing the appearance of the product, Improved dimensional accuracy and weight repeatability.

In the process of injection molding, the process variables P and T will show obvious nonlinear time-varying characteristics, and then there will be a phenomenon that deviates from the standard molding process path. The molding process path of each product is compared with the standard molding process path, so that The monitoring of molding defects of injection molded products is realized.

Compare the P corresponding to a certain stage T of each product in the molding process with P ₀ on the corresponding standard molding process path.

The mold auxiliary pressure regulation controller in the mold auxiliary pressure regulation module can control the work of the mold auxiliary pressure regulation plasticizing system and the mold auxiliary pressure regulation injection system according to the comparison results, so that the P corresponding to a certain stage T and the corresponding standard P ₀ is always consistent on the molding process path.

The advantages of the present invention are:

1. A self-healing control device and method for injection molded product defects of the present invention can perform online self-repair of injection molding defects without human intervention, realize intelligent, efficient and continuous production and processing, and avoid waste of manpower, material resources, and financial resources .

2. An injection molding product defect self-healing control device and method of the present invention, by comparing the molding process path of each product with the standard molding process path, realizes the autonomous repair of product molding defects, and is not affected by the subjective factors of the operator , The product appearance, dimensional accuracy and weight repeatability are high.

3. A device and method for self-healing control of injection molded product defects in the present invention can avoid the interference of external factors and the influence of the performance change of the equipment actuator itself, adjust the pressure in the mold cavity in real time, and realize the closed-loop control of the molding quality of injection molded products.

Description of drawings

Fig. 1 is an overall schematic diagram of a defect self-healing control device for injection molded products according to the present invention.

Figure 2 is the polymer PVT characteristic curve and product molding process path.

In the figure: 1. Plasticizing servo motor, 2. Screw 1, 3. Barrel 1, 4. Barrel heating ring 1, 5. Hopper 1, 6. Injection hydraulic cylinder, 7. Plunger, 8. Melt material Cylinder, 9. Barrel 2, 10. Screw 2, 11. Hopper 2, 12. Injection servo motor, 13. Pre-plastic servo motor, 14. Data acquisition module, 15. Product molding defect evaluation and judgment module, 16. Mold auxiliary Pressure regulating controller, 17. temperature sensor, 18. mold cavity, 19. pressure sensor, 20. mould.

detailed description

Now in conjunction with the accompanying drawings, the patent of the present invention is described in detail as follows, so as to understand the technical idea to be protected in the present invention more clearly:

The present invention is a defect self-healing control device and method for injection molded products. The device includes a PT monitoring device, a product molding defect evaluation and judgment module 15, and a mold auxiliary pressure regulation module. The PT monitoring device is installed in the mold clamping system of the injection molding machine , the monitoring device is composed of a pressure sensor 19, a temperature sensor 17 and a data acquisition module 14, which can monitor the pressure P and temperature T in the mold cavity of each product during the molding process. The data acquisition module 14 and the product forming defect evaluation and judgment module 15 The interface is connected, and the collected data is input into the product forming defect evaluation and judgment module 15; the product forming defect evaluation and judgment module 15 compares the forming process path of each product with the standard forming process path, and then inputs the comparison result into In the mold auxiliary pressure regulation module; the mold auxiliary pressure regulation module includes the mold auxiliary pressure regulation controller 16, the mold auxiliary pressure regulation plasticization system and the mold auxiliary pressure regulation injection system, and the mold auxiliary pressure regulation plasticization system passes the material through the screw plasticization system The plasticization is uniform. Since the amount of melt required for pressure regulation in the cavity already filled with melt is very small, the plunger system is used to replenish the material in the cavity 18 to adjust the pressure in the cavity; when the pressure in the cavity 18 is high Part of the material may enter the melt barrel 8 . The mold-assisted pressure regulating plasticizing system shown in Fig. 1 is a plasticizing system composed of a material 5, a barrel 3, a screw 2, a barrel heating ring 4, and a plasticizing servo motor 1. The barrel 8, the plunger 7 and the injection cylinder 6 form an auxiliary melt injection system, and the mold auxiliary pressure regulation module regulates the pressure in the mold cavity 18 in real time according to the comparison result to ensure the accuracy of the product. There is a heating ring on the outside of the melt barrel 8 to control the temperature; the barrel heating ring-4 is used to control the temperature of the barrel-3. The screw 2 10 on the right side in Fig. 1, the barrel heating ring 3 9, the hopper 2 11, the injection servo motor 12 and the pre-molding servo motor 13 form the main injection system, and the injection servo motor 12 and the pre-molding servo motor 13 drive the screw 2 10 realizes the plasticization and injection of the material, the material in the mold cavity 18 is mainly injected by the main injection system, and the plasticization and plunger injection system on the left is a part of the auxiliary pressure regulating module of the mold.

The invention relates to a defect self-healing control system of injection molding products, which is applied to the self-healing control of defects of injection molding products. Its application mainly includes the following steps: use the polymer PVT tester to obtain the PVT characteristic curve of the polymer; the molding process of each product can be divided into four stages: plasticization, injection, pressure holding, and cooling. The polymer PVT characteristic curve and the relative change relationship between P and T can draw a curve as the molding process path of the product, and record the molding process path of the standard product that meets the requirements as the standard molding process path of this type of product. As shown in Figure 2, the control route is the dotted line A-B-C-D-E-F in the figure. Simultaneously in each product forming process, monitor the variation of pressure P and temperature T in cavity 18 by PT monitoring device, input the data collected in the product forming defect evaluation and judgment module 15; product forming defect evaluation and judgment module 15 will The P corresponding to a certain stage T of each product in the molding process is compared with the pressure value on the corresponding standard molding process path, and then the comparison result is input into the mold auxiliary pressure regulation module; the mold auxiliary pressure regulation module The mold auxiliary pressure regulating controller 16 controls the work of the mold auxiliary pressure regulating plasticizing system and the mold auxiliary pressure regulating injection system according to the comparison results, so that P corresponding to a certain stage T is on the standard molding process path corresponding to Figure 2 The pressure value is always consistent, so that the molding process path of each product in the injection process can be repeated with the standard molding process path with high precision, and the product appearance, dimensional accuracy and weight repeatability are improved.

For those skilled in the art, various other corresponding changes and modifications can be made according to the technical solutions and concepts described above, and all these changes and modifications should fall within the protection scope of the present invention.

Claims (3)

1. A defect self-healing control device for injection molding products, characterized in that it mainly includes a PT monitoring device, a product forming defect evaluation and judgment module, and a mold auxiliary pressure regulation module, and the PT monitoring device is installed in the mold clamping system of the injection molding machine , the monitoring device is composed of a pressure sensor, a temperature sensor and a data acquisition module, which can monitor the pressure P and temperature T in the mold cavity of each product during the molding process. The data acquisition module is connected to the interface of the product molding defect evaluation and judgment module. The received data is input into the product molding defect evaluation and judgment module; the product molding defect evaluation and judgment module compares the molding process path of each product with the standard molding process path, and then inputs the comparison result into the mold auxiliary pressure regulation module; The mold auxiliary pressure regulation module includes the mold auxiliary pressure regulation controller, the mold auxiliary pressure regulation plasticizing system and the mold auxiliary pressure regulation injection system. pressure. 2. A defect self-healing control device for injection molded products according to claim 1, characterized in that: the mold auxiliary pressure regulating plasticizing system is a screw plasticizing system, which is heated by hopper 1, barrel 1, screw 1, and barrel Composed of ring one and plasticizing servo motor; the mold auxiliary pressure regulating injection system is a plunger injection system, which is composed of a melt barrel, a plunger and an injection cylinder. 3. The method for adopting a kind of injection molding product defect self-healing regulating device according to claim 1 is characterized in that mainly comprising the following steps: utilizing a polymer PVT tester to obtain the PVT characteristic curve of the polymer; the molding process of each product is divided into There are four stages of plasticization, injection, pressure holding, and cooling. In this process, based on the polymer PVT characteristic curve and the relative change relationship between P and T, a curve can be drawn as the molding process path of the product, and standard products that meet the requirements can be recorded. The molding process path of this type of product is used as the standard molding process path of this type of product, as the quality ID of this type of product; at the same time, during the molding process of each product, after the main injection system completes plasticization and injection, the PT monitoring device monitors the pressure holding , the change of pressure P and temperature T in the mold cavity during the cooling process, and input the collected data into the evaluation and judgment module of product molding defects; The corresponding P is compared with the pressure value on the corresponding standard molding process path, and then the comparison result is input into the mold auxiliary pressure regulation module; the mold auxiliary pressure regulation controller in the mold auxiliary pressure regulation module controls according to the comparison result The mold-assisted pressure-regulating plasticizing system and the mold-assisted pressure-regulating injection system work so that the P corresponding to a certain stage T is always consistent with the pressure value on the corresponding standard molding process path, so that the pressure of each product during the injection process The molding process path can be repeated with high precision with the standard molding process path, which improves the appearance, dimensional accuracy and weight repeatability of the product.