Three-phase high-low frequency composite rotating magnetic field induction heating device and method

Abstract

The invention discloses a three-phase high-low frequency composite rotating magnetic field induction heating device and method. The device comprises a three-phase high-low frequency rotating magnetic field variable-frequency power supply device, a three-phase high-frequency coupling capacitor, a three-phase low-frequency coupling reactor and a three-phase inductor, the three-phase high-low frequency rotating magnetic field variable-frequency power supply device outputs three-phase high-low frequency composite alternating current with the angle difference of 120 degrees; the three-phase high-frequency frequency conversion series resonance circuit and the three-phase coupling capacitor are combined to form a three-phase high-frequency series resonance working mode; the parallel resonance circuit for the three-phase low-frequency frequency conversion and the three-phase coupling reactor form a three-phase low-frequency parallel resonance working mode; the three-phase inductor participates in high-frequency and low-frequency resonance at the same time to generate a high-low-frequency composite rotating magnetic field. Forward and reverse rotation of the magnetic field can be achieved, any high and low frequency combined rotating magnetic field induction heating is conducted on a heated metal object, and the induction heating quenching effect on the tooth top of a gear with the high frequency and the tooth groove with the low frequency is better than the using effect of a traditional single-frequency non-rotating magnetic field.

Description

Technical Field

[0001] The present invention relates to the technical field of electromagnetic induction heating, and particularly to a three-phase high-low frequency composite rotating magnetic field induction heating device and method. Background Art

[0002] At present, there are a large number of workpieces to be heated with different specifications in the production process of the induction heating field. Due to their different shapes and sizes, different heating depths are required, and different induction power supply frequencies are selected. It is difficult to select a set of power supply frequencies to meet various heating requirements, which has become a problem that must be faced and urgently solved by countries around the world. Traditional induction heating power supplies generally use multiple single-frequency models to heat workpieces of different sizes. However, due to the need for multi-station switching, it is time-consuming, laborious, energy-consuming, costly, and the heating effect with a single frequency is not good. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to overcome the existing defects, and provide a three-phase high-low frequency composite rotating magnetic field induction heating device and method, which can simultaneously perform induction heating on metals of different specifications, sizes, with high efficiency and good heating effect, and has better use effect than single-frequency induction heating in some use scenarios, and can effectively solve the problems in the background art.

[0004] To achieve the above invention purpose, the present invention provides the following technical solutions: A three-phase high-low frequency composite rotating magnetic field induction heating device includes a three-phase high-low frequency composite variable frequency power supply device, three groups of high-frequency coupling capacitors, three groups of low-frequency coupling reactors, and a three-phase inductor. The three groups of high-frequency coupling capacitors are connected in series in the high-frequency three-phase AC circuit; The three groups of low-frequency coupling reactors are connected in series in the low-frequency three-phase AC circuit.

[0005] The three groups of high-frequency coupling capacitors are connected in series between the three-phase high-low frequency rotating magnetic field variable frequency power supply device and the three-phase induction coil to form a three-phase high-frequency series resonance working mode; The three groups of low-frequency coupling reactors are connected in series between the three-phase high-low frequency rotating magnetic field variable frequency power supply device and the three-phase induction coil, and form a three-phase parallel resonance working mode with the internal capacitor; A three-phase high-low frequency composite rotating magnetic field induction heating device, wherein the three-phase high-low frequency rotating magnetic field variable frequency power supply device outputs two groups of three-phase alternating currents, one group is a low-frequency three-phase alternating current with a frequency of 50Hz - 500Hz, and the other group is a high-frequency three-phase alternating current with a frequency of 1000Hz - 20000Hz; A three-phase high-low frequency composite rotating magnetic field induction heating device, wherein the working mode of the three-phase high-low frequency rotating magnetic field variable frequency power supply device is that the low frequency and the high frequency work simultaneously, or the low frequency and the high frequency work separately.

[0006] Preferably, the devices used in the three-phase high-low frequency rotating magnetic field variable frequency power supply device are all-controlled power semiconductor IGBT devices.

[0007] Preferably, the three-phase high-low frequency rotating magnetic field variable frequency power supply device outputs three-phase high-low frequency composite alternating current with a phase difference of 120° between each phase.

[0008] Preferably, the phase editing of the three-phase currents of the three-phase high-low frequency rotating magnetic field variable frequency power supply device is carried out to realize the forward and reverse rotation of the magnetic field.

[0009] A preparation method of a three-phase high-low frequency composite rotating magnetic field induction heating device includes: a high-frequency induction quenching device, a low-frequency induction quenching device, and a high-low frequency composite induction quenching device; 1) The high-frequency output end of the three-phase high-low frequency rotating magnetic field variable frequency power supply cabinet is connected to a coupling capacitor and a three-phase inductor to form a high-frequency induction quenching device. The specific implementation steps are as follows: (1) A three-phase inductor composed of three groups of inductors; (2) The three-phase high-frequency output ends of the three-phase high-low frequency rotating magnetic field variable frequency power supply cabinet are connected to a coupling capacitor, and the coupling capacitor is connected to the inductor; (3) The three-phase high-frequency output of the three-phase high-low frequency rotating magnetic field variable frequency power supply cabinet sets the frequency to 20000 Hz (4) The three-phase low-frequency output of the three-phase high-low frequency rotating magnetic field variable frequency power supply cabinet is turned off; Power frequency Hz: 20000; Heating depth mm: 1.8 ± 0.2; Hardened layer depth mm: 1 ± 0.3; Transition layer thickness mm: 0.8; 2) The low-frequency output end of the three-phase high-low frequency rotating magnetic field variable frequency power supply cabinet is connected to a coupling reactor and a three-phase inductor to form a low-frequency induction quenching device. The specific implementation steps are as follows: (1) A three-phase inductor composed of three groups of inductors; (2) The three-phase low-frequency output ends of the three-phase high-low frequency rotating magnetic field variable frequency power supply cabinet are connected to a coupling reactor, and the coupling reactor is connected to the inductor; (3) The three-phase low-frequency output of the three-phase high-low frequency rotating magnetic field variable frequency power supply cabinet sets the frequency to 50 Hz; (4) The three-phase high-frequency output of the three-phase high-low frequency rotating magnetic field variable frequency power supply cabinet is turned off; Technical performance: Power frequency Hz: 50; Heating depth mm: 71 ± 1; Hardened layer depth mm: 35 ± 0.5; Transition layer thickness mm: 30; 3) The three-phase high-low frequency rotating magnetic field variable frequency power supply cabinet is connected to a three-phase inductor to form a high-low frequency composite induction quenching device. The specific implementation steps are as follows: (1) A three-phase inductor composed of three groups of inductors; (2) The three-phase high-frequency output terminal of the three-phase high-low frequency rotating magnetic field variable frequency power supply cabinet is connected to the coupling capacitor, and the coupling capacitor is connected to the inductor; (3) The three-phase low-frequency output terminal of the three-phase high-low frequency rotating magnetic field variable frequency power supply cabinet is connected to the coupling reactor, and the coupling reactor is connected to the inductor (4) The set frequency of the three-phase low-frequency output of the three-phase high-low frequency rotating magnetic field variable frequency power supply cabinet is 500 Hz (5) The set frequency of the three-phase high-frequency output of the three-phase high-low frequency rotating magnetic field variable frequency power supply cabinet is 20,000 Hz Technical performance: Power supply frequency Hz: 500 + 20000; Heating depth mm: 10 ± 0.5; Hardened layer depth mm: 3.5 ± 0.5; Transition layer thickness mm: 6.

[0010] Compared with the prior art, the beneficial effects of the present invention are: A three-phase high-low frequency composite rotating magnetic field induction heating device and method, the three-phase high-low frequency rotating magnetic field variable frequency power supply device adopted outputs two groups of three-phase alternating currents, one group is low-frequency three-phase alternating current with a frequency of 50 Hz to 500 Hz, and the other group is high-frequency three-phase alternating current with a frequency of 1000 Hz to 20,000 Hz. The high frequency has a large surface induction intensity and high efficiency, while the low frequency has a strong heating force for depth, and at the same time has the advantages of good induction heating effect for large and small shapes. In some use scenarios, it has a better use effect than the single-frequency magnetic field non-rotating induction heating. Description of the drawings

[0011] Figure 1 It is a structural schematic diagram of the present invention.

[0012] Figure 2 It is a schematic diagram of three-phase high-low frequency rotating magnetic field induction heating of the present invention.

[0013] In the figure: 1. Three-phase high-low frequency rotating magnetic field variable frequency power supply device, 2. Three-phase high-frequency coupling capacitor, 3. Three-phase coupling reactor, 4. Three-phase inductor composed of three groups of coils. Specific implementation manners

[0014] The present invention can be explained in detail through the following embodiments. The purpose of publicly disclosing the invention is to protect all technologies within the scope of the present invention. In the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "front", "rear", "left", "right", etc. indicating the orientation or positional relationship, they are only corresponding to the drawings of the present application for the convenience of describing the present invention, rather than indicating or implying that the device or element referred to must have a specific orientation.

[0015] Please refer to Figure 1 and Figure 2As shown in the figure, the present invention provides a technical solution: a three-phase high-low frequency composite rotating magnetic field induction heating device, including a three-phase high-low frequency rotating magnetic field variable frequency power supply device 1, three groups of high-frequency coupling capacitors 2, three groups of low-frequency coupling reactors 3, and a three-phase inductor 4; The three-phase high-low frequency rotating magnetic field variable frequency power supply device 1 outputs two groups of three-phase alternating currents, one group is a low-frequency three-phase alternating current with a frequency of 50Hz to 500Hz, and the other group is a high-frequency three-phase alternating current with a frequency of 1000Hz to 20000Hz; the high frequency has a large surface induction intensity and high efficiency, while the low frequency has a strong heating force for depth, and at the same time has the advantage of good induction heating effect for large and small shapes. In some usage scenarios, it has a better usage effect than the single-frequency magnetic field non-rotating induction heating.

[0016] The three groups of high-frequency coupling capacitors 2 are respectively connected in series between each phase of the high-low frequency composite variable frequency power supply device 1 and the three-phase inductor 4 to form a three-phase high-frequency series resonance working mode; The three groups of low-frequency coupling reactors 3 are respectively connected in series between the three-phase high-low frequency composite variable frequency power supply device 1 and the three-phase inductor 4, and form a three-phase low-frequency parallel resonance working mode with the internal capacitance; Furthermore, the three-phase high-low frequency rotating magnetic field variable frequency power supply device works with low frequency and high frequency simultaneously, or works with low frequency and high frequency separately.

[0017] Furthermore, the three-phase high-low frequency rotating magnetic field variable frequency power supply device outputs a three-phase high-low frequency composite alternating current with a phase difference of 120° between phases; Furthermore, the three-phase current phases of the three-phase high-low frequency rotating magnetic field variable frequency power supply device are phase-edited to realize the forward and reverse rotation of the magnetic field; The following embodiments are intended to further illustrate the present invention, but should not be construed as limiting the protection scope of the present invention. Some non-essential improvements and adjustments made by those skilled in the art to the present invention based on the above content of the present invention still fall within the protection scope of the present invention. Embodiment 1:

[0018] A three-phase high-low frequency composite rotating magnetic field induction heating device, the high-frequency output end of the three-phase high-low frequency rotating magnetic field variable frequency power supply cabinet is connected to the coupling capacitor and the three-phase inductor to form a high-frequency induction hardening device; The preparation method is as follows: (1) The three-phase inductor 4 composed of three groups of inductors; (2) The three-phase high-frequency output ends of the three-phase high-low frequency rotating magnetic field variable frequency power supply 1 are connected to the high-frequency coupling capacitor 2, and the high-frequency coupling capacitor 4 is connected to the three inductors 4; (3) The set frequency of the three-phase high-frequency output of the three-phase high-low frequency rotating magnetic field variable frequency power supply cabinet is 20000Hz; (4) The three-phase low-frequency output of the three-phase high-low frequency rotating magnetic field variable frequency power supply cabinet is turned off. Example 2:

[0019] A three-phase high-low frequency composite rotating magnetic field induction heating device, where the low-frequency output terminal of the three-phase high-low frequency rotating magnetic field variable frequency power supply cabinet is connected to a coupling reactor and a three-phase inductor to form a low-frequency induction hardening device; The preparation method is as follows: (1) A three-phase inductor 4 composed of three groups of inductors; (2) The three-phase low-frequency output terminals of the three-phase high-low frequency rotating magnetic field variable frequency power supply cabinet are connected to a low-frequency coupling reactor, and the low-frequency coupling reactor is connected to the three-phase inductor 4; (3) The set frequency of the three-phase low-frequency output of the three-phase high-low frequency rotating magnetic field variable frequency power supply cabinet is 50 Hz; (4) The three-phase high-frequency output of the three-phase high-low frequency rotating magnetic field variable frequency power supply cabinet is turned off. Example 3:

[0020] A three-phase high-low frequency composite rotating magnetic field induction heating device, where the three-phase high-low frequency rotating magnetic field variable frequency power supply cabinet is connected to a three-phase inductor to form a high-low frequency composite induction hardening device.

[0021] The preparation method is as follows: (1) A three-phase inductor 4 composed of three groups of inductors; (2) The three-phase high-frequency output terminals of the three-phase high-low frequency rotating magnetic field variable frequency power supply cabinet are connected to a high-frequency coupling capacitor 2, and the high-frequency coupling capacitor is connected to the three-phase inductor 4; (3) The three-phase low-frequency output terminals of the three-phase high-low frequency rotating magnetic field variable frequency power supply cabinet are connected to a low-frequency coupling reactor 3, and the low-frequency coupling reactor 3 is connected to the three-phase inductor 4; (4) The set frequency of the three-phase low-frequency output of the three-phase high-low frequency rotating magnetic field variable frequency power supply cabinet is 500 Hz; (5) The set frequency of the three-phase high-frequency output of the three-phase high-low frequency rotating magnetic field variable frequency power supply cabinet is 20000 Hz.

[0022] Comparing the present invention with the existing single-frequency induction hardening furnace with a frequency of 20 KHz, see Table 1: Table 1 Performance comparison table of a three-phase high-low frequency composite rotating magnetic field induction heating device and its preparation method

[0023] From Table 1, it can be seen by comparing the test performances of Examples 1 to 3 with the prior art that, compared with Table 1, Examples 1 to 3 not only have better performance, but also have an obvious transition layer effect that exceeds the traditional process.

[0024] The present invention includes a three-phase high-low frequency rotating magnetic field variable frequency power supply device, three-phase high-frequency coupling capacitors, three-phase low-frequency coupling reactors, and three-phase inductors; the three-phase high-low frequency rotating magnetic field variable frequency power supply device outputs three-phase high-low frequency composite alternating current with a 120° phase difference; the three-phase high-frequency variable frequency adopts a series resonance circuit, and the three-phase coupling capacitors are respectively connected in series between the high-frequency output terminals of the three-phase high-low frequency rotating magnetic field variable frequency power supply cabinet and the three-phase induction coils to form a three-phase high-frequency series resonance working mode; the three-phase coupling reactors are respectively connected in series at the low-frequency output terminals of the three-phase high-low frequency rotating magnetic field variable frequency power supply cabinet to form a three-phase low-frequency parallel resonance working mode. The three-phase induction coils participate in the resonance of high and low frequencies simultaneously to generate a high-low frequency composite rotating magnetic field. The present invention can simultaneously perform phase editing on three-phase high-low frequency currents to realize the forward and reverse rotation of the magnetic field, and perform induction heating on the metal object to be heated with any high-low frequency combination rotating magnetic field. In particular, it has the advantage of good induction heating quenching effect for the tooth tips of gears that require high frequency and tooth grooves that require low frequency. It has a better use effect than traditional single-frequency non-rotating magnetic fields in some scenarios of induction melting, quenching, and electromagnetic stirring.

[0025] The parts not detailed in the present invention are prior art. For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention; therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention.

Claims

1. A three-phase high-low frequency composite rotating magnetic field induction heating device, characterized in that: It includes a three-phase high-low frequency rotating magnetic field variable frequency power supply (1), three groups of high-frequency coupling capacitors (2), three groups of low-frequency coupling reactors (3), and a three-phase inductor (4). The three groups of high-frequency coupling capacitors (2) are connected in series in the high-frequency end of the three-phase high-low frequency rotating magnetic field variable frequency power supply device (1) and the circuit of the three-phase inductor (4) to form a three-phase high-frequency series resonance working mode; the three groups of low-frequency coupling reactors (3) are connected in series in the low-frequency end of the three-phase high-low frequency rotating magnetic field variable frequency power supply (1) and the circuit of the three-phase inductor (4); and together with the internal parallel resonance capacitor, they form a three-phase parallel resonance working mode.

2. The three-phase high-low frequency composite rotating magnetic field induction heating device according to claim 1, characterized in that: The three-phase high-low frequency rotating magnetic field variable frequency power supply (1) is an output three-phase dual-frequency composite AC circuit, one group is a low-frequency three-phase AC circuit with a frequency of 50Hz - 500Hz, and the other group is a high-frequency three-phase AC circuit with a frequency of 1000Hz - 20000Hz.

3. A three-phase high-low frequency composite rotating magnetic field induction heating device according to claim 1, characterized in that: The three-phase high-low frequency rotating magnetic field variable frequency power supply (1) is an output three-phase high-low frequency composite AC current circuit with a phase difference of 120° between phases; the three-phase current phases of the three-phase high-low frequency rotating magnetic field variable frequency power supply (1) are used for phase editing to realize the forward and reverse rotation of the magnetic field.

4. A three-phase high-low frequency composite rotating magnetic field induction heating device according to claim 1, characterized in that: The three-phase high-low frequency rotating magnetic field variable frequency power supply (1) adopts a three-phase high-frequency series resonance circuit with fully controlled IGBT power semiconductor devices.

5. A three-phase high-low frequency composite rotating magnetic field induction heating device according to claim 1, characterized in that: The three-phase high-low frequency rotating magnetic field variable frequency power supply (1) adopts a three-phase low-frequency parallel resonance circuit with fully controlled IGBT power semiconductor devices.

6. A three-phase high-low frequency composite rotating magnetic field induction heating device according to claim 1, characterized in that: The three-phase high-low frequency rotating magnetic field variable frequency power supply (1) operates with three-phase low frequency and three-phase high frequency working simultaneously, or three-phase low frequency and three-phase high frequency working independently.

7. A preparation method of a three-phase high-low frequency composite rotating magnetic field induction heating device according to claim 1, characterized in that: It includes: A high-frequency induction hardening device, a low-frequency induction hardening device, and a high-low frequency composite induction hardening device; 1) The high-frequency output end of the three-phase high-low frequency rotating magnetic field variable frequency power supply cabinet is connected to the high-frequency coupling capacitor and the three-phase inductor to form a high-frequency induction hardening device. The specific implementation steps are as follows: (1) The three-phase inductor composed of three groups of inductors; (2) The three-phase high-frequency output end of the three-phase high-low frequency rotating magnetic field variable frequency power supply cabinet is connected to the high-frequency coupling capacitor, and the high-frequency coupling capacitor is connected to the three-phase inductor; (3) The three-phase high-frequency output of the three-phase high-low frequency composite rotating magnetic field induction heating power supply cabinet is set to a frequency of 20000Hz (4) The three-phase low-frequency output of the three-phase high-low frequency rotating magnetic field variable frequency power supply cabinet is turned off; Power frequency Hz: 20000; Heating depth mm: 1.8 ± 0.2; Hardened layer depth mm: 1 ± 0.3; Transition layer thickness mm: 0.8; 2) The low-frequency output end of the three-phase high-low frequency rotating magnetic field variable frequency power supply cabinet is connected to the coupling reactor and the three-phase inductor to form a low-frequency induction hardening device. The specific implementation steps are as follows: (1) The three-phase inductor composed of three groups of inductors; (2) The three-phase low-frequency output end of the three-phase high-low frequency rotating magnetic field variable frequency power supply cabinet is connected to the low-frequency coupling reactor, and the low-frequency coupling reactor is connected to the three-phase inductor; (3) The three-phase low-frequency output of the three-phase high-low frequency rotating magnetic field variable frequency power supply cabinet is set to a frequency of 50Hz; (4) The three-phase high-frequency output of the three-phase high-low frequency rotating magnetic field variable frequency power supply cabinet is turned off; Technical performance: Power supply frequency Hz: 50; Heating depth mm: 71 ± 1; Hardened layer depth mm: 35 ± 0.5; Transition layer thickness mm: 30; 3) The three-phase high-low frequency rotating magnetic field variable frequency power supply is connected to the three-phase inductor to form a high-low frequency composite induction hardening device. The specific implementation steps are as follows: (1) The three-phase inductor composed of three groups of inductors; (2) The three-phase high-frequency output terminals of the three-phase high-low frequency rotating magnetic field variable frequency power supply cabinet are connected to the high-frequency coupling capacitor, and the high-frequency coupling capacitor is connected to the three-phase inductor; (3) The three-phase low-frequency output terminals of the three-phase high-low frequency rotating magnetic field variable frequency power supply cabinet are connected to the low-frequency coupling reactor, and the low-frequency coupling reactor is connected to the three-phase inductor; (4) The set frequency of the three-phase low-frequency output of the three-phase high-low frequency rotating magnetic field variable frequency power supply cabinet is 500 Hz; (5) The set frequency of the three-phase high-frequency output of the three-phase high-low frequency rotating magnetic field variable frequency power supply cabinet is 20,000 Hz; Technical performance: Power supply frequency Hz: 500 + 20,000; Heating depth mm: 10 ± 0.5; Hardened layer depth mm: 3.5 ± 0.5; Transition layer thickness mm: 6.

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