System and method for feeding back and finely adjusting weight of injection molding part in real time

Abstract

The invention provides a system and method for feeding back the weight of an injection molding part in real time and conducting fine adjustment. The system comprises a mold module, an injection molding machine module, a weighing module, a PLC module, a mechanical arm module and a man-machine interaction interface module. The mold module is used for molding and processing injection-molded parts; the injection molding machine module is matched with the mold module to complete injection molding; the weighing module is used for measuring weight information of the injection molding part; the PLC module is used for reading weight feedback measured by the weighing module; and the mechanical arm module is used for taking out the injection molding parts from the mold module and placing the injection molding parts on the weighing module, and screening and placing the injection molding parts after receiving a qualified or unqualified judgment signal sent by the PLC module. According to the invention, real-time state refreshing and fine tuning are realized, the problem that the weight of an injection molded part is difficult to frequently and finely tune is solved, the concentration ratio of weight data under a large sample is improved while an out-of-tolerance product is rejected, and the real-time state is displayed on a human-computer interaction interface.

Description

Technical Field

[0001] The present invention relates to the field of injection molding technology, and in particular to a system and method for real-time feedback of injection molded part weight and fine-tuning. Background Art

[0002] There have always been many problems in traditional injection molding technology. First, due to the fluctuation of raw material density and the instability of injection molding process parameters, the weight of injection molded parts is often prone to large deviations. There are often differences in raw materials from different batches, which will cause changes in raw material density. For example, the density of some batches of raw materials may be different from that of other batches due to factors such as composition and production process. The instability of injection molding pressure will also affect the injection volume. Too high pressure may lead to excessive injection volume, while too low pressure may lead to insufficient injection volume. These factors work together to cause deviations in the weight of injection molded parts, which seriously affects the consistency of product quality. Especially for some precision products, such as precious metal product packaging, electronic component housings, and automotive parts injection molded parts, the weight requirements are extremely strict. Excessive weight deviation will cause great obstacles to the subsequent assembly process and affect the overall performance of the product. When producing injection molded parts with large samples, the concentration of weight data is poor under the traditional method, and it is difficult to stably control the product weight near the established target intermediate value, which brings great uncertainty to the generation.

[0003] Secondly, in order to ensure product quality, process parameters often need to be adjusted manually. This method is not only inefficient, but also greatly increases labor costs. Frequent adjustments are complicated and time-consuming.

[0004] At the same time, during the production process, the sensor's feedback on the weight of the injection molded parts is often not timely and accurate. Due to limitations in sensor accuracy and response speed, it is impossible to feed back accurate weight information to the control system in the first place. It is also difficult for the control system to quickly adjust the injection molding process parameters based on the feedback data, which makes it difficult to effectively improve production efficiency and product quality. In an increasingly competitive market environment, this situation obviously cannot meet the needs of modern industrial production.

[0005] Through searching patent documents, it was found that the utility model patent with the publication number CN206493552U discloses an injection molding abnormal handling management system, which includes a PLC module. The PLC module is connected to the abnormal alarm module on the injection molding machine, the injection molding machine mold closing and injection signal sensor, and the injection molding machine mold opening signal sensor. The manipulator is also connected to the PLC module; the PLC module is also connected to the confirmation fault elimination input module, the defective product forced waste input module and the product quality confirmation input module. The injection molding machine and the manipulator are centrally controlled by the PLC module. After the abnormal alarm of the equipment is confirmed to be eliminated, the equipment must be automatically transferred to the manipulator working mode for full-automatic production according to the set waste number under semi-automatic conditions. Ensure that the operation of the manipulator is under certain controlled conditions and that the waste products do not flow into normal products. This patent mainly focuses on the abnormal handling management of injection molding, lacks content on product weight control and related refined production adjustments.

[0006] In summary, in view of the above-mentioned problems of the prior art, researching a system and method for real-time feedback of the weight of injection molded parts and performing fine-tuning has become a key task that needs to be solved urgently. Summary of the invention

[0007] In view of the defects in the prior art, the object of the present invention is to provide a system and method for real-time feedback of the weight of injection molded parts and fine-tuning.

[0008] A system for real-time feedback of the weight of an injection molded part and fine-tuning the weight of the injection molded part provided by the present invention comprises: a mold module, an injection molding machine module, a weighing module, a PLC module, a robotic arm module and a human-computer interaction interface module;

[0009] The mold module is used for molding and processing injection molded parts and is connected to the PLC module;

[0010] The injection molding machine module cooperates with the mold module to complete injection molding and is connected to the PLC module;

[0011] Weighing module, used to measure the weight information of injection molded parts, connected with PLC module;

[0012] The PLC module is used to read the weight feedback measured by the weighing module, make logical judgments, select strategies and fine-tune the hardware process parameters of the injection molding machine module and the mold module with the human-machine interface module, and control the actions of the robotic arm module;

[0013] The robot module is used to take the injection molded parts out of the mold module, place them on the weighing module, transmit the weighing completion signal to the PLC module, and screen and place the injection molded parts after receiving the qualified or unqualified judgment signal from the PLC module;

[0014] Human-machine interaction interface module, used to interact with the PLC module.

[0015] Preferably, the mold module comprises a mold unit and a solenoid valve connected to each other, the solenoid valve is used to control the feeding of the mold unit, and the PLC module controls the switch of the solenoid valve.

[0016] Preferably, the mold unit adopts a needle valve injection port structure, and the solenoid valve is used to control the opening and closing of the needle valve.

[0017] Preferably, the weighing module includes a sensor, a weighing station and an instrument, the weighing station is used to place the injection molded parts, the sensor is used to measure the weight of the injection molded parts, the PLC module reads the weight feedback measured by the sensor, and the instrument displays the weight feedback measured by the sensor.

[0018] Preferably, the human-computer interaction interface module includes an automatic mode and a manual mode. In the automatic mode, the injection time T1 of the system parameter is automatically adjusted according to the setting; in the manual mode, the injection time T1 and the adjustment value ΔT of the system parameter are manually set, and the human-computer interaction interface module counts and compiles the products falling into different weight intervals.

[0019] The present invention also provides a method for real-time feedback of the weight of an injection molded part and fine-tuning the weight of the injection molded part. The method uses the system for real-time feedback of the weight of an injection molded part and fine-tuning the weight of the injection molded part, and comprises the following steps:

[0020] Injection molding production steps: set the initial value of injection time T1 and the adjustment value ΔT of T1 each time through the human-machine interaction interface module, and set the injection time T2 of the injection molding machine module to be slightly greater than T1; when the injection molding machine module starts to close the mold, and after the mold unit is closed, the injection signal of the main board of the injection molding machine module is sent to the PLC module, and at the same time, the injection molding machine module starts injection molding and applies injection pressure, and the PLC module starts timing T1 and controls the solenoid valve to open;

[0021] In-mold cooling step: After T1 timing ends, the PLC module controls the solenoid valve to cut off power and close the injection port of the mold unit. The remaining time of T2 is automatically transferred to the in-mold cooling time;

[0022] Taking out and weighing steps: When the cooling time in the mold is over, the mold unit opens, the robot module takes the injection molded part out of the mold unit, and places it on the weighing module for weighing. The robot module rises to a high position and waits for the weighing to stabilize, and then transmits the weighing completion signal to the PLC module;

[0023] Classification and fine-tuning steps: When the PLC module receives the weighing completion signal, it reads the weight feedback of the weighing module. The PLC module makes logical judgments, selects strategies and fine-tunes the hardware process parameters of the injection molding machine module and the mold module based on the weight feedback, and obtains the adjusted injection time T1″. The adjusted injection time T1″ is used in the production of the injection molded parts of the next mold. The human-computer interaction interface module displays the adjusted injection time T1″, and assigns T1″ to T1, which is used for the time control of the next mold, and counts the number of products in different weight states;

[0024] Product sorting steps: After the robot module receives the judgment signal sent by the PLC module, if the judgment signal is qualified, the injection molded parts will be placed in the qualified product area; if the judgment signal is unqualified, the injection molded parts will be placed in the unqualified product area, and the robot module will return to the mold module to wait for the next mold injection molded part to be picked up.

[0025] Preferably, in the injection molding production step, the injection time T2 of the injection molding machine module is set to be slightly greater than the injection time T1, and the time difference is 1-2 seconds.

[0026] Preferably, in the classification and fine-tuning steps, the weight feedback of the weighing module is received in one of active switching quantity, passive switching quantity, MODBUS RTU or Ethernet.

[0027] Preferably, the process of logical judgment, strategy selection and fine-tuning of the hardware process parameters of the injection molding machine module and the mold module includes the following sub-steps:

[0028] Logical judgment step: The PLC module judges the weight status of the current product based on the weight feedback;

[0029] Strategy selection step: if the weight state is one of state 2, state 3 or state 4, the product is qualified, and the PLC module sends a qualified judgment signal to the manipulator module; if the weight state is one of state 1 or state 5, the product is unqualified, and the PLC module sends an unqualified judgment signal to the manipulator module;

[0030] Fine-tuning steps: If the weight state is one of state one or state two, adjust the injection time T1″=(T1-ΔT); if the weight state is one of state four or state five, adjust the injection time T1″=(T1+ΔT); if the weight state is state three, adjust the injection time T1″=T1.

[0031] Preferably, in the state judgment step, the weight state is divided into five types, namely: state one, overweight; state two, heavy but within tolerance; state three, normal; state four, light but within tolerance; state five, underweight.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] 1. The present invention uses weighing modules, sensors and instrumentation equipment to feedback real-time status, uses PLC and human-computer interactive touch screen for logical judgment, strategy selection and parameter modification, and fine-tunes the key process parameters of injection molding machines and mold hardware equipment. The essence of the traditional method is to remove the out-of-tolerance parts at both ends after the sample is normally distributed, and the offset of the sample center value cannot be solved. The present invention allows the weight of the product to always float around the middle value of the established target, and solves the problem of frequent manual adjustment when the tolerance is small in the traditional method.

[0034] 2. The present invention realizes real-time status refresh and fine-tuning through the linkage of injection molding machine, mold, manipulator, weighing module, instrument and PLC equipment, solves the problem of frequent fine-tuning of weight of injection molded parts, and improves the concentration of weight data under large samples and the drift of the center value of large samples while eliminating out-of-tolerance products, and displays the real-time status on the human-computer interaction interface. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0036] Figure 1 Schematic diagram of a system for real-time feedback of injection molded part weight and fine-tuning in an embodiment of the present invention. DETAILED DESCRIPTION

[0037] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several changes and improvements can also be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0038] Embodiment 1:

[0039] Figure 1 Schematic diagram of a system for real-time feedback of injection molded part weight and fine-tuning in an embodiment of the present invention.

[0040] like Figure 1 As shown, an embodiment of the present invention provides a system 100 for real-time feedback of injection molded part weight and fine-tuning, including a mold module 10, an injection molding machine module 20, a weighing module 30, a PLC module 40, a robotic arm module 50 and a human-computer interaction interface module 60.

[0041] The mold module 10 is used for molding injection molded parts and is connected to the PLC module 40 .

[0042] In this embodiment, the mold module 10 includes a mold unit 11 and a solenoid valve 12 which are connected to each other. The solenoid valve 12 is used to control the feeding of the mold unit 11 , and the PLC module 40 controls the switch of the solenoid valve 12 .

[0043] In this embodiment, the mold unit 11 adopts a needle valve injection port structure, and the solenoid valve 12 is used to control the opening and closing of the needle valve.

[0044] The injection molding machine module 20 cooperates with the mold module 10 to complete injection molding, and the injection molding machine module 20 is connected to the PLC module 40 .

[0045] The weighing module 30 is used to measure the weight information of the injection molded part and is connected to the PLC module 40 .

[0046] The weighing module 30 includes a sensor, a weighing station and an instrument. The weighing station is used to place the injection molded parts, the sensor is used to measure the weight of the injection molded parts, the PLC module 40 reads the weight feedback measured by the sensor, and the instrument displays the weight feedback measured by the sensor.

[0047] The PLC module 40 is used to read the weight feedback measured by the weighing module 30, perform logic judgment, strategy selection and fine-tune the hardware process parameters of the injection molding machine module 20 and the mold module 10 with the human-machine interaction interface module 60, and control the action of the robot arm module 50.

[0048] The robot arm module is used to take the injection molded parts out of the mold module, place them on the weighing module, transmit the weighing completion signal to the PLC module, and screen and place the injection molded parts after receiving the qualified or unqualified judgment signal from the PLC module.

[0049] The human-machine interaction interface module 60 is used to interact with the PLC module 40 .

[0050] The human-machine interaction interface module 60 includes an automatic mode and a manual mode. In the automatic mode, the injection time T1 of the system parameter is automatically adjusted according to the setting; in the manual mode, the injection time T1 and the adjustment value ΔT of the system parameter are manually set, and the human-machine interaction interface module 60 counts and statistics the products falling into different weight intervals.

[0051] Embodiment 2:

[0052] This embodiment provides a method for real-time feedback of the weight of an injection molded part and fine-tuning the weight of the injection molded part, and the system for real-time feedback of the weight of the injection molded part and fine-tuning the weight of the injection molded part in the above embodiment 1 is applied, and the method includes the following steps:

[0053] Injection molding production steps: set the initial value of injection time T1 and the adjustment value ΔT of T1 each time through the human-computer interaction interface module, and set the injection time T2 of the injection molding machine module to be slightly larger than T1; when the injection molding machine module starts to close the mold and the mold unit is closed, the injection signal of the main board of the injection molding machine module is sent to the PLC module, and at the same time the injection molding machine module starts injection molding and applies injection pressure, the PLC module starts timing T1 and controls the solenoid valve to open.

[0054] In this embodiment, the injection time T2 of the injection molding machine module is set to be slightly greater than the injection time T1, and the time difference is 1-2 seconds.

[0055] In-mold cooling step: After T1 timing ends, the PLC module controls the solenoid valve to cut off the power and close the injection port of the mold unit. The remaining time of T2 is automatically transferred to the in-mold cooling time.

[0056] Removal and weighing steps: When the cooling time in the mold is over, the mold unit opens, the robot module takes the injection molded part out of the mold unit, and places it on the weighing module for weighing. The robot module rises to a high position and waits for the weighing to stabilize, and then transmits the weighing completion signal to the PLC module.

[0057] Classification and fine-tuning steps: When the PLC module receives the weighing completion signal, it reads the weight feedback of the weighing module. The PLC module performs logical judgment, strategy selection and fine-tunes the hardware process parameters of the injection molding machine module and the mold module based on the weight feedback, and obtains the adjusted injection time T1". The adjusted injection time T1" is used in the production of injection molded parts for the next mold. The human-computer interaction interface module displays the adjusted injection time T1", and at the same time assigns T1" to T1, which is used for the time control of the next mold, and counts the number of products in different weight states.

[0058] In this embodiment, the weight feedback of the weighing module is received in one of active switch quantity, passive switch quantity, MODBUS RTU or Ethernet.

[0059] Specifically, the process of logical judgment, strategy selection and fine-tuning of the hardware process parameters of the injection molding machine module and the mold module includes the following sub-steps:

[0060] Logical judgment steps: The PLC module judges the current weight status of the product based on the weight feedback.

[0061] In this embodiment, the weight status is divided into five types, namely: status one, overweight; status two, slightly heavy but within tolerance; status three, normal; status four, slightly light but within tolerance; status five, underweight.

[0062] Strategy selection step: if the weight state is one of state 2, state 3 or state 4, the product is qualified, and the PLC module sends a qualified judgment signal to the manipulator module; if the weight state is one of state 1 or state 5, the product is unqualified, and the PLC module sends an unqualified judgment signal to the manipulator module;

[0063] Fine-tuning steps: If the weight state is one of state one or state two, adjust the injection time T1″=(T1-ΔT); if the weight state is one of state four or state five, adjust the injection time T1″=(T1+ΔT); if the weight state is state three, adjust the injection time T1″=T1.

[0064] Product sorting steps: After the robot module receives the judgment signal sent by the PLC module, if the judgment signal is qualified, the injection molded parts will be placed in the qualified product area; if the judgment signal is unqualified, the injection molded parts will be placed in the unqualified product area, and the robot module will return to the mold module to wait for the next mold injection molded part to be picked up.

[0065] Those skilled in the art know that, in addition to realizing the system and its various devices, modules, and units provided by the present invention in a purely computer-readable program code, the system and its various devices, modules, and units provided by the present invention can be completely realized in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, and embedded microcontrollers by logically programming the method steps to realize the same functions. Therefore, the system and its various devices, modules, and units provided by the present invention can be considered as a hardware component, and the devices, modules, and units included therein for realizing various functions can also be regarded as structures within the hardware component; the devices, modules, and units for realizing various functions can also be regarded as both software modules for realizing the method and structures within the hardware component.

[0066] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. In the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. A system for real-time feedback of injection molded part weight and fine-tuning, characterized in that: include: Mold module, injection molding machine module, weighing module, PLC module, robotic arm module and human-computer interaction interface module; The mold module is used for molding injection molded parts and is connected to the PLC module; The injection molding machine module cooperates with the mold module to complete injection molding and is connected to the PLC module; The weighing module is used to measure the weight information of the injection molded part and is connected to the PLC module; The PLC module is used to read the weight feedback measured by the weighing module, perform logic judgment, strategy selection and fine-tune the hardware process parameters of the injection molding machine module and the mold module with the human-computer interaction interface module, and control the action of the robotic arm module; The robot module is used to take the injection molded parts out of the mold module, place them on the weighing module, transmit the weighing completion signal to the PLC module, and screen and place the injection molded parts after receiving the qualified or unqualified judgment signal from the PLC module; The human-machine interaction interface module is used to interact with the PLC module.

2. The system for real-time feedback of injection molded part weight and fine-tuning according to claim 1, characterized in that: The mold module includes a mold unit and a solenoid valve connected to each other. The solenoid valve is used to control the feeding of the mold unit, and the PLC module controls the switch of the solenoid valve.

3. The system for real-time feedback of injection molded part weight and fine-tuning according to claim 2, characterized in that: The mold unit adopts a needle valve injection port structure, and the solenoid valve is used to control the opening and closing of the needle valve.

4. The system for real-time feedback of injection molded part weight and fine-tuning according to claim 1, characterized in that: The weighing module includes a sensor, a weighing station and an instrument. The weighing station is used to place the injection molded parts, the sensor is used to measure the weight of the injection molded parts, the PLC module reads the weight feedback measured by the sensor, and the instrument displays the weight feedback measured by the sensor.

5. The system for real-time feedback of injection molded part weight and fine-tuning according to claim 1, characterized in that: The human-machine interaction interface module includes an automatic mode and a manual mode. In the automatic mode, the injection time T1 of the system parameter is automatically adjusted according to the setting; in the manual mode, the injection time T1 and the adjustment value ΔT of the system parameter are manually and forcibly set. The human-machine interaction interface module counts and compiles the products falling into different weight intervals.

6. A method for real-time feedback of injection molded part weight and fine-tuning, using the system for real-time feedback of injection molded part weight and fine-tuning according to claim 5, characterized in that: The steps include: Injection molding production steps: setting the initial value of injection molding time T1 and the adjustment value ΔT of T1 each time through the human-machine interaction interface module, and setting the injection time T2 of the injection molding machine module to be slightly greater than T1; when the injection molding machine module starts to close the mold, and after the mold unit is closed, the injection signal of the main board of the injection molding machine module is sent to the PLC module, and at the same time, the injection molding machine module starts injection molding and applies injection pressure, and the PLC module starts timing T1 and controls the solenoid valve to open; In-mold cooling step: after the T1 timing ends, the PLC module controls the solenoid valve to cut off the power, closes the injection port of the mold unit, and the remaining time of T2 is automatically transferred to the in-mold cooling time; Taking out and weighing step: when the cooling time in the mold is over, the mold unit is opened, the manipulator module takes the injection molded part out of the mold unit, and places it on the weighing module for weighing. After the manipulator module rises to a high position and waits for the weighing to stabilize, it transmits the weighing completion signal to the PLC module; Classification and fine-tuning steps: when the PLC module receives the weighing completion signal, it reads the weight feedback of the weighing module, and the PLC module performs logical judgment, strategy selection and fine-tunes the hardware process parameters of the injection molding machine module and the mold module according to the weight feedback, and obtains the adjusted injection time T1″, and the adjusted injection time T1″ is used in the production of injection molded parts of the next mold, and the human-computer interaction interface module displays the adjusted injection time T1″, and at the same time assigns T1″ to T1, and is used for the time control of the next mold, and the number of products in different weight states is counted; Product sorting step: after the robot module receives the judgment signal sent by the PLC module, if the judgment signal is qualified, the injection molded parts are placed in the qualified product area; if the judgment signal is unqualified, the injection molded parts are placed in the unqualified product area, and the robot module returns to the mold module to wait for the next mold injection molded part to be picked up.

7. The method for real-time feedback of injection molded part weight and fine-tuning according to claim 6, characterized in that: In the injection molding production step, the injection time T2 of the injection molding machine module is set to be slightly longer than the injection time T1, and the time difference is 1-2 seconds.

8. The method for real-time feedback of injection molded part weight and fine-tuning according to claim 6, characterized in that: In the classification and fine-tuning steps, the weight feedback of the weighing module is received in one of active switching quantity, passive switching quantity, MODBUS RTU or Ethernet.

9. The method for real-time feedback of injection molded part weight and fine-tuning according to claim 6, characterized in that: The process of logic judgment, strategy selection and fine-tuning the hardware process parameters of the injection molding machine module and the mold module includes the following sub-steps: Logical judgment step: the PLC module judges the weight status of the current product according to the weight feedback; Strategy selection step: if the weight state is one of state 2, state 3 or state 4, the product is a qualified product, and the PLC module sends a qualified determination signal to the manipulator module; if the weight state is one of state 1 or state 5, the product is a failed product, and the PLC module sends a failed determination signal to the manipulator module; Fine-tuning steps: if the weight state is one of state one or state two, adjust the injection time T1″=(T1-ΔT); if the weight state is one of state four or state five, adjust the injection time T1″=(T1+ΔT); if the weight state is state three, adjust the injection time T1″=T1.

10. The method for real-time feedback of injection molded part weight and fine-tuning according to claim 9, characterized in that: In the state judgment step, the weight state is divided into five types, namely: state one, overweight; state two, heavy but within tolerance; state three, normal; state four, light but within tolerance; state five, underweight.

Images