JP2001203069A - Electromagnetic induction heating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an electromagnetic induction heating device enhanced in efficiency and reliability. SOLUTION: The electromagnetic induction heating device comprises a bobbin 1 made of insulating material, a heating coil 2 wound on the bobbin 1 with high frequency electric current and a cylindrical heater 3 which is provided in the above bobbin 1 and heated by the high frequency electric current flowing to the heating coil 2, and further, a liquid passage 4 provided at a certain interval between the bobbin 1 and the heater 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic induction heating apparatus for generating an eddy current in a substrate by electromagnetic induction to generate heat, and for bringing a gas or liquid into contact with the substrate to heat the substrate.

[0002]

2. Description of the Related Art Conventional heating devices for heating fluids such as liquids and gases include boilers, various heat exchangers and various dryers for industrial use, and gas combustion for home use (consumer use). There are many types of combustion systems such as appliances, oil burning appliances, and instantaneous water heaters utilizing gas oil combustion.

[0003] Since these heating sources use oil or gas, storage and piping are required, so-called auxiliary equipment is required, and secondary damage such as exhaust gas and oxygen deficiency as combustion heating is required. And safety issues such as ignition.

On the other hand, as a method using electricity as a heating source, an electric heater is generally used, but a heating method using electromagnetic induction heating which is more efficient in terms of thermal power has been applied.

As a heating device for heating a fluid such as a liquid or a gas, there is a system in which a fluid is passed through a metal hollow pipe provided in a cylindrical heating coil, and the metal pipe generates heat.

[0006]

The characteristic of electromagnetic induction heating is that the metal body is heated by internal heat generation on the surface of the metal body due to the skin effect. Therefore, the high-frequency magnetic field generated by the heating coil wound around the outer periphery of the metal body causes an electromagnetic induction action only on the surface of the metal body inside the heating coil, so that only the surface of the metal body is locally heated.

For this reason, heat exchange with the fluid due to heat generation is indirect, and the rise of temperature is also delayed, so that there is a drawback that accurate temperature control is not possible.
Further, the portions other than the fluid passages in the axial direction are heated by electromagnetic induction, which causes a reduction in efficiency.

[0008]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and a heating element is provided in a bobbin around which a heating coil is wound, and the heating element is used as a fluid passage. A fluid passage is also formed between the heating element and the bobbin. Alternatively, the outer peripheral portion of the bobbin around which the heating coil is wound is covered with a structure, and a fluid passage is also provided between the structure and the bobbin.

[0009]

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a bobbin made of an insulator, a heating coil wound around the bobbin to enable the passage of a high-frequency current, and a cylindrical coil inside the bobbin which generates heat by the high-frequency current flowing through the heating coil. And an electromagnetic induction heating device in which a fluid passage is formed by providing a fixed gap between the bobbin and the heating element.

Alternatively, an external fluid passage is formed by providing a cylindrical structure for covering the outer peripheral portion of the bobbin around which the heating coil is wound, with a certain gap provided between the structure and the heating coil. Things.

With such a configuration, the principle of electromagnetic induction can be effectively operated, the temperature controllability can be improved efficiently, and the heat-resistant temperature of the insulator of the heating coil can be suppressed low. It also has the effect of suppressing the rise in product costs.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a structural diagram of an electromagnetic induction heating device according to one embodiment of the present invention, and FIG. 2 is a structural diagram of an electromagnetic induction heating device according to another embodiment.

In FIG. 1, reference numeral 1 denotes a bobbin made of a cylindrical insulator. A heating coil 2 is wound in a cylindrical shape around the outer periphery of the bobbin 1, and an alternating current that changes in the axial direction when a high-frequency current is supplied. It generates a magnetic field.

Inside a bobbin 1 of an insulator, a hollow metal heating element 3 that absorbs a high-frequency magnetic field to generate an eddy current to generate heat is coaxially arranged. In addition, bobbin 1
A fluid passage 4 is formed with a certain gap between the heating element 3 and the heating element 3.

When the heating coil 2 is energized, a high-frequency eddy current is generated on the surface of the metal heating element 3 and heated by electromagnetic induction. Hollow part of heating element 3 (main fluid passage)
Is heated to a predetermined temperature by passing a fluid such as air at a constant speed and is discharged.

At this time, the fluid such as air flows simultaneously to both the main fluid passage in the hollow portion of the heating element 3 and the fluid passage 4 in the outer peripheral portion, so that the heat is effectively used. Further, since a cooling effect in which the inside of the heating coil 2 is cooled by the fluid is obtained, it is possible to prevent the temperature of the bobbin 1 which is an insulator of the heating coil 2 from rising.

In FIG. 2, reference numeral 1 denotes a bobbin made of a cylindrical insulator. A heating coil 2 is wound in a cylindrical shape around the outer periphery of the bobbin 1, and a high-frequency current is applied to the bobbin to change the axial direction. It generates a magnetic field.

Inside the bobbin 1 made of an insulator, a hollow metal heating element 3 that absorbs a high-frequency magnetic field and generates an eddy current to generate heat is coaxially arranged. In addition, bobbin 1
A fluid passage 4 is formed with a certain gap between the heating element 3 and the heating element 3.

Reference numeral 5 denotes a cylindrical structure that covers the outer periphery of the bobbin 1 wound with the heating coil 2 for heating. A fixed gap is provided between the structure 5 and the heating coil 2, and the gap is configured as an external fluid passage 6.

A high-frequency eddy current is generated on the surface of the metal heating element 3 when the heating coil 2 is energized, and is heated by electromagnetic induction. Hollow part of heating element 3 (main fluid passage)
Is heated to a predetermined temperature by passing a fluid such as air at a constant speed and is discharged.

At this time, the fluid such as air flows simultaneously to the main fluid passage in the hollow portion of the heating element 3 and the fluid passage 4 and the external fluid passage 6 in the outer peripheral portion, so that the heat is effectively used. Further, since a cooling effect in which the inside and outside of the heating coil 2 are cooled by a fluid is obtained, a rise in the temperature of the bobbin 1 which is an insulator of the heating coil 2 can be prevented.

Accordingly, the structure shown in FIG. 2 covers the state shown in FIG. 1 with the structure 5 so that a fluid can flow also to the outer peripheral portion of the heating coil 2 so that the entire heating coil 2 can be cooled. The heat loss due to self-heating can be effectively used for heating the fluid, and the efficiency of the entire apparatus can be improved.

Although the apparatus has a cylindrical configuration in the embodiment, the same effect can be obtained by using a rectangular or other cylindrical configuration.

[0024]

According to the present invention, a heating element is provided inside an insulating bobbin having a heating coil wound on the outer periphery thereof, and a predetermined gap is provided between the bobbin and the heating element to form a fluid passage. By providing a structure or covering an outer peripheral portion of a bobbin wound with a coil, providing a fixed gap between the structure and the bobbin, and providing an external fluid passage, a fluid such as air is generated by a heating element. Since the fluid flows through the fluid passage of the hollow portion and the outer peripheral portion, or the external fluid passage, heat generation is effectively used, and the inside of the bobbin is cooled by the fluid, or the outer peripheral portion of the coil is also cooled. By doing so, the entire coil can be cooled.

As described above, the present invention can effectively utilize the heat generated inside and outside the heating element and the heat generated by the resistance loss of the coil itself.
A thermal efficiency close to 0% can be obtained, and a cooling effect for both the coil and the bobbin can be expected, thereby improving the efficiency and the temperature controllability. Furthermore, the heat resistance temperature of the insulator can be kept low, and the cost of the product can be kept low.

[Brief description of the drawings]

FIG. 1 is a structural view of an electromagnetic induction heating device showing one embodiment of the present invention.

FIG. 2 is a structural view of an electromagnetic induction heating device showing another embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1 bobbin 2 heating coil 3 heating element 4 fluid path 5 structure 6 external fluid path

Claims (2)

[Claims] 1. A bobbin (1) made of an insulator, a heating coil (2) wound around the bobbin (1) and capable of supplying a high-frequency current, and a heating coil (2) inside the bobbin (1). A cylindrical heating element (3) that generates heat by a high-frequency current flowing through the bobbin, and a fluid passage (4) is formed by providing a constant gap between the bobbin (1) and the heating element (3). Electromagnetic induction heating device. 2. A tubular structure (5) for covering an outer peripheral portion of a bobbin (1) wound with a heating coil (2), and a fixed structure is provided between the structure (5) and the heating coil (2). 2. The electromagnetic induction heating device according to claim 1, wherein an external fluid passage is formed by providing a gap.