Planar biaxial local induction heating system and method

Abstract

The invention discloses a planar double-shaft local induction heating system and method, three modes of PID control, a multi-section mode and a user-defined mode are adopted, the user-defined mode allows a user to finely adjust the temperature limit value of each section, the temperature control precision is improved, the system is realized based on the nonlinear heating principle of induction heating and a limit heating method, an induction coil adopts a flat wire, and the temperature control precision is improved. The heating end face forming induction is a plane, and compared with a non-plane heating face, the heating end face has better uniform heating performance, so that the temperature precision can be controlled to be + / -1 DEG C.

Description

Technical Field

[0001] The invention relates to the field of test equipment, and in particular to a planar biaxial local induction heating system and method. Background Art

[0002] At present, with the development of the global aviation industry and the development of my country's aviation industry, many technologies that were previously available can be directly imported from abroad to fill domestic gaps.

[0003] Utility model CN201720758664.3 designs a large-scale biaxial in-situ in-plane transmission fatigue testing machine, which uses a high-temperature furnace to heat the planar biaxial fatigue test piece. However, due to the large installation space required, it cannot be applied to the planar biaxial fatigue test pieces used in the in-situ test.

[0004] Utility model CN201621442812.2 designs a high-temperature biaxial synchronous tensile mechanical property testing instrument, which uses a high-temperature furnace to heat a planar biaxial fatigue test piece. However, due to the requirements of sealing and cooling of the high-temperature furnace, it can only be applied to planar biaxial fatigue test pieces of fixed size and cannot be adjusted.

[0005] The maximum temperature difference of the local induction heating disclosed above is controlled at ±5 degrees, which still cannot meet the temperature control accuracy requirements for tests on some specific materials.

[0006] In summary, a planar biaxial local induction heating system and method is needed to address the deficiencies in the prior art. Summary of the invention

[0007] In view of the deficiencies in the prior art, the present invention provides a planar biaxial local induction heating system and method, aiming to solve the above problems.

[0008] To achieve the above-mentioned object, the present invention provides the following technical solutions: a planar biaxial local induction heating system, comprising at least one induction coil for generating a changing magnetic field;

[0009] A high-frequency AC power source, connected to the induction coil, for supplying power to the induction coil;

[0010] A control unit connected to the high-frequency AC power supply and used to control the frequency and power output by the power supply;

[0011] A temperature detection device is provided on the object to be heated and is used to monitor the temperature of the heating area;

[0012] A cooling device for reducing the operating temperature of the induction coil and the power supply equipment;

[0013] Biaxial stretching machine, used to fix and conduct tensile tests on objects to be heated.

[0014] Optionally, the heating system further comprises a position adjustment mechanism for controlling the position of the object to be heated relative to the induction coil.

[0015] Optionally, the control unit further includes a temperature feedback control module, which is used to automatically adjust the power output power of the power supply according to information fed back by the temperature detection device.

[0016] Optionally, the cooling device adopts a circulating water cooling method, and the heating end surface of the induction coil is a plane.

[0017] A planar biaxial local induction heating method, using a planar biaxial local induction heating system, comprises the following steps:

[0018] Step S1: placing the object to be heated on a biaxial stretching machine;

[0019] Step S2: adjusting the relative position of the induction coil and the position adjustment mechanism so that the heating area of ​​the induction coil covers the heating area of ​​the sample required to be heated;

[0020] Step S3: starting the high-frequency AC power supply and setting a suitable frequency and power through the control unit;

[0021] Step S4: monitoring the temperature change during the heating process through the temperature detection device, judging whether the temperature of the object to be heated reaches the requirement through the control unit, and adjusting the heating frequency and power through the control unit;

[0022] Step S5: When the object to be heated reaches the temperature required by the test, a corresponding test is performed;

[0023] Step S6: After the test is completed, the high-frequency AC power supply is turned off, the object to be heated after the test is removed, and the test of the next object to be heated can be started.

[0024] Optionally, the temperature control mode of the control unit includes:

[0025] Adopt closed-loop temperature control, use temperature sensors and equipment to form a closed-loop control system,

[0026] Normal mode: PID control is adopted;

[0027] Multi-stage mode: Based on the normal mode, variable temperature control is added to set and control multiple target temperatures;

[0028] Custom mode: Based on the multi-stage mode, the temperature fine-tuning function for each stage is added.

[0029] Optionally, the control unit adopts open-loop temperature control, nonlinear heating and extreme heating methods using induction heating;

[0030] Optionally, the sampling method of the temperature detection device in step S4 is:

[0031] The average value is used for sampling and compared with the historical temperature average value for judgment.

[0032] Optionally, the temperature control unit includes multiple temperature control channels for setting the maximum value, minimum value and average value of the temperature.

[0033] Beneficial effects of the present invention:

[0034] 1. In the present invention, PID control, multi-stage mode and custom mode are adopted. The custom mode allows the user to fine-tune the temperature limit value of each stage to improve the temperature control accuracy. It is based on the nonlinear heating principle and limit heating method of induction heating. The induction coil adopts a flat wire to form a flat heating end surface. Compared with a non-planar heating surface, it has better uniform heating performance, so that the temperature can be within ±1 degree.

[0035] 2. In the present invention, average value sampling is adopted. The specific sampling data volume N needs to be determined through a large number of experiments to balance the response speed and filtering effect. The system supports five temperature control channels, including infrared temperature measurement and thermocouple temperature measurement. The maximum value, minimum value and average value of each channel can be set;

[0036] 3. In the present invention, the heating position can be controlled very accurately through the dual-axis mobile platform. Compared with the traditional heating method, the induction heating directly acts on the target area, reducing energy loss. It has a complete fault detection and protection mechanism, such as insufficient water, overheating, overcurrent, overvoltage and other fault alarms and protection measures, supports multiple temperature control modes, and can meet different heating needs, especially for occasions that require precise temperature control. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a schematic diagram of a three-dimensional structure of the present invention.

[0038] Figure 2 The figure is a schematic diagram of a system structure of the present invention.

[0039] Figure 3 The present invention is a schematic flow chart of a method.

[0040] In the figure: 1. induction coil; 2. high-frequency AC power supply; 3. control unit; 4. temperature detection device; 5. cooling device; 6. position adjustment mechanism; 7. biaxial stretching machine. DETAILED DESCRIPTION

[0041] In order to more clearly illustrate the embodiments of the invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0042] like Figure 1 and Figure 2 As shown, a planar biaxial local induction heating system comprises at least one induction coil 1 for generating a changing magnetic field;

[0043] A high frequency AC power source 2, connected to the induction coil, for supplying power to the induction coil;

[0044] A control unit 3, connected to the high-frequency AC power supply, and used to control the frequency and power output by the power supply;

[0045] The temperature detection device 4 is arranged on one side of the object to be heated and is used to monitor the temperature of the heating area;

[0046] A cooling device 5, used to reduce the operating temperature of the induction coil and the power supply equipment;

[0047] The biaxial stretching machine 7 is used to fix and perform a stretching test on the object to be heated.

[0048] The heating system further comprises a position adjustment mechanism 6 for controlling the position of the object to be heated relative to the induction coil.

[0049] The control unit also includes a temperature feedback control module, which is used to automatically adjust the power output of the power supply according to the information fed back by the temperature detection device.

[0050] The cooling device adopts a circulating water cooling method, and the heating end surface of the induction coil is a plane.

[0051] like Figure 3 As shown, a planar biaxial local induction heating method, using a planar biaxial local induction heating system, includes the following steps:

[0052] Step S1: placing the heated object on the biaxial stretching machine 7;

[0053] Step S2: adjusting the relative position of the induction coil and the position adjustment mechanism so that the induction coil covers the heating area of ​​the wood strip;

[0054] Step S3: starting the high-frequency AC power supply and setting a suitable frequency and power through the control unit;

[0055] Step S4: monitoring the temperature change during the heating process through the temperature detection device, judging whether the temperature of the object to be heated reaches the requirement through the control unit, and adjusting the heating frequency and power through the control unit;

[0056] Step S5: When the object to be heated reaches the temperature required by the test, a corresponding test is performed;

[0057] Step S6: After the test is completed, the high-frequency AC power supply is turned off, the object to be heated after the test is removed, and the test of the next object to be heated can be started.

[0058] The temperature control modes of the control unit include:

[0059] Adopt closed-loop temperature control, use temperature sensors and equipment to form a closed-loop control system,

[0060] Normal mode: PID control is adopted;

[0061] Multi-stage mode: Based on the normal mode, variable temperature control is added to set and control multiple target temperatures;

[0062] Custom mode: Based on the multi-stage mode, the temperature limit value of each stage can be fine-tuned.

[0063] The control unit adopts nonlinear heating and extreme heating methods of induction heating;

[0064] The sampling method of the temperature detection device in step S4 is:

[0065] The average value is used for sampling and compared with the historical temperature average value for judgment.

[0066] The temperature control unit includes a plurality of temperature control channels for setting the maximum value, the minimum value and the average value of the temperature.

[0067] The temperature control range of the present invention is: 100℃-3000℃, the temperature control accuracy is: ±1℃, and the minimum area of ​​the heating area is: S=πr 2 >=π16mm, uniform temperature zone: temperature difference ≤2℃.

[0068] The present invention adopts closed-loop temperature control, using temperature control sensors and equipment to form a closed-loop temperature control system; and open-loop temperature control, using the nonlinear heating principle of induction heating and the limit heating method to achieve.

[0069] Control Mode:

[0070] General mode: PID control is adopted.

[0071] Multi-stage mode: inherits the functions of the general mode, adds variable temperature control, and realizes the setting and control of multiple target temperatures.

[0072] Custom mode: inherits the multi-stage mode function, and adds the ability to fine-tune the temperature limit of each stage, making temperature control more precise.

[0073] The working principle of the present invention: PID closed-loop temperature control method and open-loop temperature control method, using the nonlinear heating principle and limit heating method of induction heating. Inductor inner diameter: ≧8mm, heating end surface: flat design to ensure uniform heating. Similar products abroad are usually made of round copper tubes, resulting in a non-planar heating surface, resulting in uneven heating and large temperature difference in the uniform temperature zone.

[0074] Multi-segment mode:

[0075] Temperature display: Displays the temperature at each stage.

[0076] Each section setting: You can set different temperatures and constant temperature time, and run it section by section during operation

[0077] Custom Mode:

[0078] Multi-segment cycle PID customization: Each cycle has eight segments, N cycles can be set, and the power percentage of each segment can be freely set to improve temperature control accuracy.

[0079] Custom percentage mode: Complete open-loop control, setting power and heating time, not setting temperature, suitable for specific application scenarios.

[0080] Number of channels: Five channels in total, channel 1 is infrared temperature control, channels 2, 3, and 4 are thermocouple temperature control.

[0081] Channel settings: You can set the maximum value, minimum value and average value. Channel 1 does not participate in these settings.

[0082] Real-time curve can display the temperature curve of each channel, and can also hide the channel curve you don’t want to see.

[0083] Display content of historical curve: historical temperature curve, similar to the real-time curve.

[0084] Function of the historical data window: View previous sample heating data and search by product code.

[0085] The present invention can control the heating position very accurately and heat quickly through a dual-axis mobile platform: induction heating is fast, can quickly reach the required temperature, is energy-saving and efficient, and compared with traditional heating methods, induction heating directly acts on the target area, reducing energy loss.

[0086] Fast heating speed: Since heat is generated directly inside the material, the heating speed is very fast. High thermal efficiency: Almost all the energy is converted into heat energy, with almost no waste. High control accuracy: Highly precise control of the heating position and temperature can be achieved. High flexibility: By adjusting the coil design and power supply parameters, it can adapt to a variety of different heating needs.

[0087] The present invention supports multiple temperature control modes and can meet different heating needs. In particular, for occasions requiring precise temperature control, it uses the principle of electromagnetic induction eddy current heating to achieve rapid heating. It is suitable for application scenarios that require efficient heating. Users can choose different temperature control modes according to actual needs, including normal mode, multi-segment mode, custom mode, etc. The system supports five temperature control channels, including infrared temperature measurement and thermocouple temperature measurement. The maximum, minimum and average values ​​of each channel can be set, and it has a complete fault detection and protection mechanism, such as fault alarms and protection measures such as lack of water, overheating, overcurrent, and overvoltage.

[0088] Directions:

[0089] Power on: Turn on the power and enter the system interface.

[0090] Mode selection: Select normal mode, multi-stage mode or custom mode according to heating needs.

[0091] Parameter setting: In the selected mode, set the target temperature, constant temperature time, upper and lower temperature limits and other parameters.

[0092] Start heating: Click the system start button to start the heating process.

[0093] Monitoring: Monitor temperature changes during heating through the real-time curve window and make adjustments when necessary.

[0094] Stop heating: After heating is completed, click the stop button to turn off heating.

[0095] Shutdown: First turn off the power switch on the front panel of the device, then turn off the external main power switch, and finally turn off the cooling water. It is recommended to continue to flow water for 5-10 minutes after the device stops working to ensure that the device is fully cooled.

[0096] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modification, equivalent substitution or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A planar biaxial local induction heating system, characterized in that: include: at least one induction coil for generating a changing magnetic field; A high-frequency AC power source, connected to the induction coil, for supplying power to the induction coil; A control unit connected to the high-frequency AC power supply and used to control the frequency and power output by the power supply; A temperature detection device is provided on the object to be heated and is used to monitor the temperature of the heating area; A cooling device for reducing the operating temperature of the induction coil and the power supply equipment; Biaxial stretching machine, used to fix and conduct tensile tests on objects to be heated.

2. The planar biaxial local induction heating system according to claim 1, characterized in that: The heating system further comprises a position adjustment mechanism for controlling the position of the object to be heated relative to the induction coil.

3. The planar biaxial local induction heating system according to claim 1, characterized in that: The control unit also includes a temperature feedback control module, which is used to automatically adjust the power output of the power supply according to the information fed back by the temperature detection device.

4. The planar biaxial local induction heating system according to claim 1, characterized in that: The cooling device adopts a circulating water cooling method, and the heating end surface of the induction coil is a plane.

5. A planar biaxial local induction heating method, using the planar biaxial local induction heating system as claimed in claim 1, characterized in that: The following steps are involved: Step S1: placing the object to be heated on a biaxial stretching machine; Step S2: adjusting the relative position of the induction coil and the position adjustment mechanism so that the heating area of ​​the induction coil covers the heating area of ​​the sample required to be heated; Step S3: starting the high-frequency AC power supply and setting a suitable frequency and power through the control unit; Step S4: monitoring the temperature change during the heating process through the temperature detection device, judging whether the temperature of the object to be heated reaches the requirement through the control unit, and adjusting the heating frequency and power through the control unit; Step S5: When the object to be heated reaches the temperature required by the test, a corresponding test is performed; Step S6: After the test is completed, the high-frequency AC power supply is turned off, the object to be heated after the test is removed, and the test of the next object to be heated can be started.

6. The planar biaxial local induction heating method according to claim 5, characterized in that: The temperature control modes of the control unit include: Adopt closed-loop temperature control, use temperature sensors and equipment to form a closed-loop control system, Normal mode: PID control is adopted; Multi-stage mode: Based on the normal mode, variable temperature control is added to set and control multiple target temperatures; Custom mode: Based on the multi-stage mode, the temperature fine-tuning function for each stage is added.

7. The planar biaxial local induction heating method according to claim 5, characterized in that: The control unit adopts open-loop temperature control, and the control unit adopts nonlinear heating and extreme heating methods of induction heating.

8. The planar biaxial local induction heating method according to claim 5, characterized in that: The sampling method of the temperature detection device in step S4 is: The average value is used for sampling and compared with the historical temperature average value for judgment.

9. The planar biaxial local induction heating method according to claim 5, characterized in that: The temperature control unit includes a plurality of temperature control channels for setting the maximum value, the minimum value and the average value of the temperature.

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