Temperature control system for plastic thermal forming equipment

Abstract

The invention provides a temperature control system for plastic thermal forming equipment, which is used for controlling the heating temperature of a load heating element in a heating device, and comprises a temperature sensing control module, a temperature control module and a temperature control module, the control module comprises a PLC (Programmable Logic Controller) and at least one analog quantity output controller, the adjusting module comprises a three-phase power supply and a plurality of power supply power adjusters, and the fusing safety module comprises a plurality of fusing protectors and is used for over-current protection and operation of a touch screen and a power supply. According to the invention, the control touch screen is matched with the PLC programmable logic controller to set the temperature required by production and the initial use voltage required by each independent load heating element, so that the problems of overlarge temperature fluctuation range and unstable actual temperature caused by passive temperature control in a traditional on-off blocking output control mode can be effectively solved; and the product yield is effectively improved, and labor waste caused by monitoring and adjusting by equipment operators at any time is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of plastic thermoforming equipment, and in particular to a temperature control system for plastic thermoforming equipment. Background Art

[0002] Blister machines, also known as thermoplastic forming machines, are machines that vacuum-form heated and plasticized thermoplastic coils such as PVC, PE, PP, PET, and HIPS into various shapes of high-end packaging boxes, frames, and other products. Specifically, the blister machine uses the vacuum suction generated by a vacuum pump to blister softened thermoplastic plastic sheets such as PVC and PET through a mold into various shapes of vacuum covers, blister trays, and bubble shells. Unlike injection molding and extrusion, which are one-step processes, it does not heat and mold plastic resins or particles or continuously form them through the same die with the same cross-section. Nor does it use machine tools, cutting tools, or other mechanical processing methods to cut off a portion of the plastic material to obtain the required shape and size. Instead, it heats the plastic sheet (board) and uses a mold, vacuum, or pressure to deform the sheet (board) to achieve the required shape and size. This is supplemented by supporting processes to achieve the application purpose.

[0003] The heating control systems of existing plastic thermoforming equipment mostly use a 220V voltage, while domestic industrial electricity is mostly 380V. When using heating elements of the same power, the wires used need to carry a larger current ampere factor, that is, power conductors with larger wire diameters need to be used. As a result, the power conductors and load neutral wires are easily overloaded, resulting in the wires heating up and becoming less durable, and increasing the risk factors.

[0004] At the same time, most of the existing electric heating control methods use an integrated SSR solid-state relay as a zero-point triggering method, but this method can only set a fixed output voltage. Specifically, due to the limitations of the performance of the SSR solid-state relay, when performing temperature control, the only way to control whether the heating device is powered on is to use the method of turning the power supply on and off to maintain the set required temperature. However, after the power is cut off and the actual temperature is lower than the required set temperature, it is easy for the power to be turned on again and the temperature to rise untimely or overheat, resulting in excessive fluctuations in the actual heating temperature and a large temperature difference range, thereby causing low yield of the finished product. Therefore, the existing technology has limitations. Summary of the Invention

[0005] The present invention is made to solve the above problems, and its purpose is to provide a temperature control system for plastic thermoforming equipment.

[0006] The present invention provides a temperature control system for plastic thermoforming equipment, which is used to control the heating temperature of a load heating element in a heating device. The temperature control module includes a temperature display and a data transmitter electrically connected to the temperature display. The temperature display is connected to a temperature sensing probe provided in the heating device and is used to collect and display the heating temperature of the load heating element. The data transmitter is used to receive and transmit temperature data.

[0007] The control module includes a PLC programmable logic controller and at least one analog output controller. The PLC programmable logic controller has multiple communication ports for communicating with a data transmitter, and the analog output controller has multiple output terminals for outputting 4-20mA current signals or 0-5V / 10V voltage signals under the control of the PLC programmable logic controller.

[0008] The regulation module includes a three-phase power supply and multiple power regulators. Each power regulator has two connection ports at the upper and lower ends. One connection port at the upper end of the power regulator is electrically connected to the three-phase power supply, and the other connection port at the upper end is electrically connected to the load heating element. A connection port at the lower end of each power regulator is electrically connected to an output end of the analog output controller.

[0009] The control touch screen is electrically connected to the PLC programmable logic controller to control the operation of the PLC programmable logic controller.

[0010] The power supply is electrically connected to the temperature sensing control module, PLC programmable logic controller, analog output controller, and control touch screen to provide a unified control voltage for the temperature sensing control module, PLC programmable logic controller, analog output controller, and control touch screen.

[0011] Another connection port at the lower end of the power regulator is electrically connected to the power supply.

[0012] In the temperature control system for plastic thermoforming equipment provided by the present invention, it can also have the following features, including: the fuse insurance module includes multiple fuse protectors, each fuse protector is connected in series between a power supply power regulator and a load heating element electrically connected to it, that is, the fuse protector is arranged at the power input end of each load heating element for overcurrent protection.

[0013] Furthermore, the upper end of each fuse protector has an outlet port electrically connected to the load heating element, and the lower end has an access port electrically connected to the power regulator and the three-phase power supply.

[0014] The temperature control system for plastic thermoforming equipment provided by the present invention can also have the following characteristics: each load heating element is equipped with an analog output controller and a power regulator.

[0015] In the temperature control system for plastic thermoforming equipment provided by the present invention, it can also have the following characteristics: the power regulator is a voltage regulating type or a power regulating type, and the output power is adjusted proportionally by the signal input by the analog output controller, thereby reducing harmonic interference.

[0016] The temperature control system for plastic thermoforming equipment provided by the present invention can also have the following feature: the output voltage of the power supply is 24V DC or 220V AC.

[0017] Functions and effects of the invention

[0018] 1. According to the temperature control system for plastic thermoforming equipment involved in the present invention, the production required temperature and the initial operating voltage required by each independent load heating element can be set by controlling the touch screen in conjunction with the PLC programmable logic controller. Therefore, when the present invention is first used, the global full-voltage output method can be used to quickly heat the system to the set production required temperature, effectively shortening the startup waiting time and reducing energy loss. Afterwards, digital control calculations are performed based on the actual monitored current temperature, and the power is proportionally increased or the voltage is reduced to control the output to achieve the purpose of precise heating control. This effectively solves the problem of excessive temperature fluctuation range and unstable actual temperature caused by traditional passive temperature control using on-off resistor output control method, effectively improving product yield and reducing the labor waste of equipment operators who need to monitor and adjust at any time.

[0019] 2. According to the present invention, a temperature control system for plastic thermoforming equipment utilizes a power regulator to drive the load heating element. Whether voltage-regulated or power-regulated, the impact on the power grid is relatively minimal. The entire heating control system offers numerous advantages, including high efficiency, no mechanical noise or wear, fast response, compact size, light weight, and low hardware cost. Furthermore, precise control of voltage, current, and power enables precise temperature control, thereby optimizing energy efficiency and effectively contributing to energy conservation and emission reduction. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a circuit diagram of a temperature control system for plastic thermoforming equipment according to the present invention;

[0021] Figure 2 This is a circuit diagram of an analog output control module in a temperature control system for plastic thermoforming equipment according to the present invention;

[0022] Figure 3The present invention is a circuit diagram of a temperature sensing control module in a temperature control system for plastic thermoforming equipment.

[0023] Description of reference numerals:

[0024] 10. Temperature sensing and control module; 11. Temperature display; 12. Data transmitter; 20. Control module; 21. PLC programmable logic controller; 22. Analog output controller; 30. Regulation module; 31. Three-phase power supply; 32. Power regulator; 40. Control touch screen; 50. Power supply; 60. Fuse module; 61. Fuse protector; A. Load heating element; B. Temperature sensor. DETAILED DESCRIPTION

[0025] In order to make the technical means, creative features, objectives and effects of the present invention easier to understand, the present invention is described in detail in the following embodiments with reference to the accompanying drawings.

[0026] Example

[0027] Figure 1 is a circuit diagram of the present invention, Figure 2 is a circuit diagram of the analog output control module in the present invention, Figure 3 This is a circuit diagram of the temperature sensing control module in the present invention.

[0028] like Figures 1 to 3 As shown, this embodiment provides a temperature control system for plastic thermoforming equipment, which is used to control the heating temperature of the load heating element in the heating device, including: a temperature sensing control module 10, a control module 20, an adjustment module 30, a control touch screen 40, a power supply 50, and a fuse module 60.

[0029] like Figure 1 and Figure 3 As shown, the temperature sensing control module 10 includes a temperature display 11 and a data transmitter 12 electrically connected to the temperature display 11. The temperature display 11 is connected to a temperature sensing probe provided in the heating device for collecting and displaying the heating temperature of the load heating element. The data transmitter 12 is used to receive and transmit temperature data.

[0030] In this embodiment, the temperature display 11 is provided with an operation switch and a temperature display scale, so that the temperature inside the heating device can be obtained in real time by cooperating with the temperature sensing probe.

[0031] In this embodiment, the data transmitter 12 is connected to the PLC programmable logic controller 21 in the control module 20 via an RS485 communication port.

[0032] like Figure 1 and Figure 2As shown, the control module 20 includes a PLC programmable logic controller 21 and at least one analog output controller 22. The PLC programmable logic controller 21 has multiple communication ports for communicating with the data transmitter 12, and the analog output controller 22 has multiple output terminals for outputting 4-20mA current signals or 0-5V / 10V voltage signals under the control of the PLC programmable logic controller 21.

[0033] like Figure 1 As shown, the regulation module 30 includes a three-phase power supply 31 and multiple power regulators 32. Each power regulator 32 is provided with two connection ports at the upper and lower ends. One connection port at the upper end of the power regulator 32 is electrically connected to the three-phase power supply 31, and the other connection port at the upper end is electrically connected to the load heating element. A connection port at the lower end of each power regulator 32 is electrically connected to an output end of the analog output controller 22.

[0034] In this embodiment, the power regulator 32 is a voltage regulating type or a power regulating type, and adjusts the output power proportionally through the signal input by the analog output controller 22, thereby reducing harmonic interference.

[0035] In this embodiment, the model of the SCR power regulator 32 is YT-3840.

[0036] like Figure 1 As shown, the control touch screen 40 is electrically connected to the PLC programmable logic controller 21 and is used to control the operation of the PLC programmable logic controller 21.

[0037] like Figure 1 As shown, the power supply 50 is electrically connected to the temperature sensing module 10, the PLC programmable logic controller 21, the analog output controller 22, and the control touch screen 40, and is used to provide a unified control voltage for the temperature sensing module 10, the PLC programmable logic controller 21, the analog output controller 22, and the control touch screen 40. Another connection port at the lower end of the power regulator 32 is electrically connected to the power supply 50.

[0038] In this embodiment, the output voltage of the power supply 50 is 24V DC or 220V AC.

[0039] like Figure 1 As shown, the fuse protection module 60 includes multiple fuse protectors 61, each fuse protector 61 is connected in series between a power supply regulator 32 and a load heating element electrically connected thereto, that is, the fuse protector 61 is arranged at the power input end of each load heating element for overcurrent protection.

[0040] In this embodiment, the upper end of each fuse protector 61 has an outlet port electrically connected to the load heating element, and the lower end has an access port electrically connected to the power regulator 32 .

[0041] In this embodiment, the model of the fuse protector 61 is RT18-32.

[0042] like Figure 1 As shown, each load heating element is equipped with an analog output controller 22 and a power regulator 32.

[0043] When using the present invention to control the heating temperature of load heating elements, the equipment operator first sets the required heating temperature and the required power usage of each load heating element via the touch screen 40. The temperature display 11 in the temperature sensing module 10 then continuously monitors the current real-time temperature within the heating device via a temperature probe and transmits this information to the programmable logic controller 21 via an information transmitter for calculation. The programmable logic controller 21 then controls the analog output controller 22 via its internally designed and programmed logic program, causing it to output a 4-20 mA or 0-5 V / 10 V signal to the SCR power regulator 32 for each group of points. Finally, the SCR power regulator 32 adjusts the actual output power of each SCR power regulator 32 via its internal trigger board according to the ratio of the input signal source, thereby causing the load heating elements in each independent circuit to heat according to the actual output power received.

[0044] In addition, a fuse protector 61 is provided in the power circuit of each load heating element in the present invention, thereby preventing the load heating element from short-circuiting or abnormal conditions that could damage the system. Furthermore, the control voltages used by the aforementioned electrical components in the present invention are derived from the same power supply 50, thereby ensuring the stability of equal voltage drive control within the circuit.

[0045] Functions and Effects of the Embodiments

[0046] According to the temperature control system for plastic thermoforming equipment involved in the present invention, the production required temperature and the initial operating voltage required by each independent load heating element can be set by controlling the touch screen in conjunction with the PLC programmable logic controller. Therefore, when the present invention is first used, the global full-voltage output method can be used to quickly heat the system to the set production required temperature, effectively shortening the startup waiting time and reducing energy loss. Afterwards, digital control calculations are performed based on the actual monitored current temperature, and the power is proportionally increased or the voltage is reduced to control the output to achieve the purpose of precise heating control. This effectively solves the problem of excessive temperature fluctuation range and unstable actual temperature caused by traditional passive temperature control using on-off resistor output control method, effectively improving product yield and reducing the labor waste of equipment operators who need to monitor and adjust at any time.

[0047] The temperature control system for plastic thermoforming equipment according to the present invention utilizes a power regulator to drive the load heating element. Whether voltage-regulated or power-regulated, the impact on the power grid is relatively minimal. The entire heating control system offers numerous advantages, including high efficiency, no mechanical noise or wear, fast response, compact size, light weight, and low hardware cost. Furthermore, precise control of voltage, current, and power enables precise temperature control, thereby optimizing energy efficiency and effectively contributing to energy conservation and emission reduction.

[0048] The above embodiments are preferred examples of the present invention and are not intended to limit the scope of protection of the present invention.

Claims

1. A temperature control system for plastic thermoforming equipment, used to control the heating temperature of a load heating element in a heating device, characterized in that: include: The temperature sensing control module includes a temperature display and a data transmitter electrically connected to the temperature display. The temperature display is connected to a temperature sensing probe provided in the heating device and is used to collect and display the heating temperature of the load heating element. The data transmitter is used to receive and transmit temperature data. The control module includes a PLC programmable logic controller and at least one analog output controller. The PLC programmable logic controller has multiple communication ports for communicating with the data transmitter, and the analog output controller has multiple output terminals for outputting 4-20mA current signals or 0-5V / 10V voltage signals under the control of the PLC programmable logic controller. The regulation module includes a three-phase power supply and multiple power regulators, each of which is provided with two connection ports at the upper and lower ends. One of the connection ports at the upper end of the power regulator is electrically connected to the three-phase power supply, and the other connection port at the upper end is electrically connected to the load heating element. One of the connection ports at the lower end of each power regulator is electrically connected to an output end of the analog output controller. A control touch screen is electrically connected to the PLC programmable logic controller and is used to control the operation of the PLC programmable logic controller. A power supply is electrically connected to the temperature sensing control module, the PLC programmable logic controller, the analog output controller, and the control touch screen, and is used to provide a unified control voltage for the temperature sensing control module, the PLC programmable logic controller, the analog output controller, and the control touch screen. Wherein, the other connection port at the lower end of the power regulator is electrically connected to the power supply.

2. The temperature control system for plastic thermoforming equipment according to claim 1, characterized in that: Also includes: The fuse protection module includes multiple fuse protectors, each of which is connected in series between a power supply regulator and a load heating element electrically connected thereto, that is, the fuse protector is arranged at the power input end of each load heating element for overcurrent protection.

3. The temperature control system for plastic thermoforming equipment according to claim 2, characterized in that: in, The upper end of each fuse protector has an outlet port electrically connected to the load heating element, and the lower end has an access port electrically connected to the power regulator.

4. The temperature control system for plastic thermoforming equipment according to claim 1, characterized in that: in, Each of the load heating elements is matched with an analog output controller and a power regulator.

5. The temperature control system for plastic thermoforming equipment according to claim 1, characterized in that: in, The power regulator is of a voltage regulating type or a power regulating type, and adjusts the output power in proportion to the signal input by the analog output controller, thereby reducing harmonic interference.

6. The temperature control system for plastic thermoforming equipment according to claim 1, characterized in that: in, The output voltage of the power supply is 24V DC or 220V AC.

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