KR101541417B1 - Eddy current induction heating device - Google Patents

Abstract

Disclosed is an eddy current induction heating device capable of applying low input load through movement of a rotor. According to the present invention, the device comprises: a motor as a main power source; a rotor rotated by the motor, and having a permanent magnet; a rotation speed detecting encoder plate installed to detect the rotation speed of the rotor; a heating element adjacently disposed to the rotor, having opened upper and lower surfaces, and made of metal; an actuator connected to the rotor by penetrating the heating element, and changing the position of the rotor according to a signal outputted from the rotation speed detecting encoder plate; and an inlet/outlet unit for inflowing and outflowing water into/from the heating element, wherein the rotor is rotated in a state of being separated from the heating element at an initial low-velocity section in which the rotor starts to rotate through the rotating speed detection of the rotor by the rotation speed detecting encoder plate, and the rotor is rotated in a state of being automatically disposed in the heating element through action of the actuator at a high-velocity section in which the rotation speed of the rotor is fast.

Description

[0001] Eddy current induction heating device [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an eddy current induction heating device, and more particularly, to an eddy current induction heating device capable of applying a low input load through movement of a rotor.

As is well known, the eddy current indicates the movement of electric charges induced in the conductor by a change in an electric field or a magnetic field or an electromagnetic wave. When a rotor with a permanent magnet is rotated, an eddy current is generated. At this time, if the rotor having the permanent magnet is wrapped with the metal material, the metallic material generates heat, and the eddy current induction heating device can be realized by using this principle. Particularly, it has been proved through various studies that induction heating using eddy current is superior to heating using conventional heat resistance. Therefore, research on a device for heating metallic material through the generation of eddy current using permanent magnet .

Such an eddy current induction heating device is basically composed of a permanent magnet or a permanent magnet attached rotor and a metal material installed to surround the rotor, that is, a heating element. However, such a conventional eddy current induction heating apparatus has a problem that a large amount of input energy is required to drive a rotor made of a permanent magnet. This is because, when the magnetic flux is alternated in the conductor, the eddy current is induced and the heat generated by the joule heat is generated. At the same time, the force which interferes with the rotation of the rotor is strongly acted according to Fleming's left-hand rule. For reference, it is the eddy current brake technology that utilizes a force that interferes with the rotation of the rotor. Such eddy current brake technology is used in contactless braking devices such as a zip-drop braking device of a playground or a braking device of a high-speed railway.

Therefore, in order to industrially use the induction heating device using the eddy current, a method of driving the rotor by overcoming the braking force generated by the eddy current and driving the induction heating device with a small input energy is needed.

This fact is reflected in the recently published academic paper 'Development of a heat generator using eddy currents' (Journal of the Korean Society of Mechanical Engineers, Vol. 33, No. 8, Vol. 287, August 2009, pp.565-572 1226-4881 KCI) In this paper, the efficiency of the heating device using the motor as the power source was measured to be 94.8 ~ 99% at the rotating speed (RPM) 118 ~ 230 of the rotor.

On the other hand, it is well known that a high input load occurs at a low rotational speed of the rotor, and a low input load can be applied at a high rotational speed. In order to overcome a high input load, It is possible to overcome this problem through use. However, when a high-torque motor is used, the heat generation efficiency is relatively lowered, so its application is not suitable.

Therefore, it is necessary to develop a new eddy current induction heating device which can increase the heat generation efficiency by using a low torque motor while lowering the input load even when the rotational speed of the rotor is low.

Published Patent Application No. 10-2013-0000270

Development of Heat Exchanger Using Eddy Current (Transactions of the Korean Society of Mechanical Engineers B, Vol 33, No 8 (August 2009) pp.565-572 1226-4881 KCI Listed)

It is an object of the present invention to provide an eddy current induction heating device capable of lowering an input load even when a rotating speed of a rotor is low.

Another object of the present invention is to provide an eddy current induction heating device capable of increasing the heat generation efficiency by using a motor of low torque.

According to an aspect of the present invention, there is provided an eddy current induction heating device comprising: a motor as a power source; A rotor rotated by the motor and including a permanent magnet; A rotation speed sensing encoder plate installed to sense the rotation speed of the rotor; A heating element disposed adjacent to the rotor, the heating element having an upper surface and a lower surface opened; An actuator connected to the rotor through the heating element and changing the position of the rotor according to a signal output from the rotation speed sensing encoder plate; And an input / output unit for receiving and discharging water in the heating element. In an initial low speed section in which the rotor starts to rotate through the rotation speed sensing of the rotor by the rotation speed sensing encoder plate, The rotor is rotated in a state in which electrons are spaced apart from the heating element and the rotor is automatically rotated in a state of being disposed inside the heating element through the operation of the actuator in a high speed section in which the rotating speed of the rotor is high.

An eddy current induction heating device according to the present invention includes: a first rotating shaft connected to the motor; A first pulley mounted on the first rotation shaft; A second rotating shaft connected to the rotor; A second pulley mounted on the second rotation shaft; And a belt installed to connect the first pulley and the second pulley.

In the eddy-current induction heating device according to the present invention, the rotor may include a truncated cone-shaped metal ring having a hole in its central portion; A plurality of permanent magnets provided at equal intervals on the outer surface of the metal ring; And a housing sandwiched between the permanent magnets to prevent the permanent magnets from being separated from the outer surface of the metal ring.

In the eddy current induction heating device according to the present invention, the heating element has a generally cylindrical ring type, and the inner surface of the first member facing the rotor is parallel to the outer surface of the rotor, ; And a second member inserted and arranged in a helical structure in the first member.

In the eddy current induction heating device according to the present invention, the heating element may be provided in a shape in which a metal pipe as a whole is spirally arranged, and an inner surface of the metal pipe facing the outer surface of the rotor is inclined.

In the eddy current induction heating apparatus according to the present invention, the actuator may be operated such that the rotor is automatically positioned inside the heating element when the rotor reaches a predetermined speed by the rotation speed sensing encoder.

The eddy current induction heating apparatus according to the present invention may further include a controller for controlling driving of the actuator according to a signal output from the rotation speed sensing encoder.

According to the present invention, the rotor is prevented from approaching the heat generating element in the initial low speed section of the rotor, and the rotor is automatically approached to the heat generating element in the high speed section.

In the eddy-current induction heating device according to the present invention, since the rotational speed of the rotor does not wrap around the rotor in the low-speed section, the force that hinders the rotation of the rotor, that is, the eddy current brake is not large, The load can be applied. Also, in a section where the rotational speed of the rotor is high, a low input load can be applied even if the circumference of the rotor is surrounded by the heating body.

Therefore, it is possible to apply a low input load even in a high-speed section having a high rotation speed as well as an initial low-speed section in which the rotational speed of the rotor is slow, thereby increasing the efficiency.

Further, since the present invention can apply a low input load even in a section where the rotational speed of the rotor is low, it is not necessary to employ a motor with a high torque. Therefore, by employing a relatively low torque motor The heating efficiency can be increased, and the equipment cost can be reduced.

1 and 2 are perspective views for explaining an eddy current induction heating apparatus and an operation thereof according to the present invention.
3A and 3B are a perspective view and a plan view for explaining a rotor of an eddy current induction heating device according to the present invention.
4A to 4C are a perspective view and a sectional view for explaining a heating element of an eddy current induction heating device according to the present invention.
FIG. 5 is a perspective view illustrating a heating element of another embodiment of an eddy current induction heating device according to the present invention. FIG.

BRIEF DESCRIPTION OF THE DRAWINGS The above objects, features and advantages of the present invention will become more apparent from the following description of embodiments with reference to the accompanying drawings. It is to be understood, however, that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. .

On the other hand, when an element is referred to herein as being on another element, it means that it may be formed directly on the other element or a third element may be interposed therebetween. Moreover, the thickness of the components in the figures is exaggerated for an effective description of the technical content.

Where the terms first, second, etc. are used herein to describe components, it is to be understood that these components are not to be limited by these terms, they are merely intended to distinguish one component from another It is used only for. The embodiments described and exemplified herein also include their complementary embodiments.

Further, when it is mentioned that the first component is operated or executed on the second component, the first component may be operated or executed in an environment where the second component is operated or executed, or may be directly or indirectly It should be understood that it is operated or executed through interaction.

The terminology used herein is for the purpose of illustrating embodiments and is not intended to be limiting of the invention. The singular forms herein include plural forms unless the context clearly dictates otherwise. That is, 'comprises' and / or 'comprising', as used herein, means that the recited element does not exclude the presence or addition of one or more other elements.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the shapes and the like of the components in the drawings may be exaggerated in order to emphasize a clearer description, and the same members are denoted by the same reference numerals in the drawings. It should also be mentioned in advance that in some cases portions of the invention that are not commonly known in the description of the invention and are not largely related to the invention are not described in order to avoid confusion without much reason to explain the present invention.

1 and 2 are perspective views for explaining an eddy current induction heating apparatus and an operation thereof according to the present invention.

The induction heating device 100 according to the present invention includes a motor 10, a rotor 20, a rotation speed sensing encoder 30, a heating element 40, an actuator 50, (60).

In addition, the eddy current induction heating device 100 according to the present invention includes components for mechanically coupling the above components, for example, rotating shafts 72-1 and 72-2, pulleys 74-1 and 74-2, A belt 76, and a connecting shaft 78. [

In addition, the eddy current induction heating apparatus 100 according to the present invention may further include a controller for controlling the driving of the actuator 50 according to a signal output from the rotation speed sensing encoder 30, although not shown.

Specifically, the motor 10 is provided to rotate the rotor 20, and although it is not shown in detail, a motor having the same or similar type and configuration as the conventional one but having a lower torque than the conventional one can be applied . This is because, as will be described later, the rotor 20 can be rotated even at a lower input load in the initial low speed section of the rotor 20. Therefore, the eddy current induction heating apparatus 100 according to the present invention can employ a motor with a lower torque than the conventional one, thereby reducing the facility cost.

The motor 10 may include, for example, a first rotation shaft 72-1 provided on the upper surface (or one side surface thereof) and a first pulley 74-1 installed on the first rotation shaft 72-1 And although not shown, it can be fixed to a specific portion in the facility by a fixing member provided on the outer circumferential surface thereof.

The rotor 20 is a substantial component for generating an eddy current, and has a structure in which a plurality of bar-shaped permanent magnets 24 are provided at equal intervals on the outer surface thereof.

3A and 3B are a perspective view and a plan view for explaining the rotor 20 of the eddy current induction heating device 100 according to the present invention. As shown in the figure, the rotor 20 has one side A metal ring 22 having an outer shape of a truncated cone having a size larger than the other side (or lower surface) and provided with a hole h for inserting the second rotation shaft 72-2 in the center thereof, A plurality of permanent magnets 24 which are equally spaced on the outer surface of the permanent magnets 24 and which have a bar shape in plan view and which have a trapezoidal shape in cross section and are respectively fitted in spaces between the permanent magnets 24, And a housing 26 made of a metal material for preventing the permanent magnets 24 from being detached from the outer surface of the housing.

The permanent magnet 24 may be formed to have a rectangular cross-sectional shape other than a trapezoidal cross-sectional shape. The housing 26 may have a cross-sectional shape corresponding to the sectional shape of the permanent magnet 24, Sectional shape so as not to be detached from the outer surface of the metal ring 22. For example, when the permanent magnet 24 is formed to have a trapezoidal cross-sectional shape, the housing 26 is formed to have an inverted trapezoidal cross-sectional shape. Alternatively, if the permanent magnet 24 is formed to have a rectangular cross- And the housing 26 are also provided so as to have a rectangular sectional shape.

The rotor 20 includes a second rotary shaft 72-2 installed on one side thereof and the second rotary shaft 72-2 is rotatably and movably installed on the second pulley 74-2 . It can be understood that this is because the outer surface of the second rotation shaft 72-2 is serrated and the inner surface of the corresponding second pulley 74-2 is also serrated

On the other hand, the first pulley 74-1 of the motor 10 and the second pulley 74-2 of the rotor 20 may be interconnected by a belt 76, 10 to the rotation of the rotor 20 as well as to accelerate the rotation speed of the rotor 20 from the rotation speed of the motor 10. [

Here, the eddy current induction heating apparatus 100 according to the present invention may include a chain instead of the belt 76. In this case, the first and second pulleys 74-1 and 74-2 It is preferable that the first rotating gear and the second rotating gear are provided.

Next, the rotation speed sensing encoder 30 is provided for sensing the rotation speed of the rotor 20 and may have a plate shape. The second pulley 74-2 and the rotor 20 may have a plate- Detects the rotational direction of the second rotary shaft 72-2 and the rotational speed of the rotor 20, and outputs the result to a control unit (not shown). Here, the rotation speed sensing encoder 30 may be understood to be the same as or similar to the conventional one, and accordingly detailed description and explanation thereof will be omitted in the embodiment of the present invention.

The heating element 40 is provided to generate an eddy current together with the rotor 20, and is formed of a metallic material, for example, and may have a cylindrical ring shape. In particular, the heating element 40 according to the embodiment of the present invention has a shape in which the upper surface and the lower surface thereof are opened so that the connecting shaft 78 of the actuator 50 is inserted while allowing the rotor 20 to be inserted.

4A to 4C illustrate a heating element 40 of the eddy current induction heating apparatus 100 according to the present invention. As shown in FIG. 4, the heating element 40 includes a cylindrical 1 member 42 and a second member 44 of a helical structure inserted and disposed inside the first member 42. [

Here, the first member 42 has an inner space of a certain width into which the second member 44 is inserted, and the inner surface of the first member 42 facing the rotor 20 is parallel to the outer surface of the rotor 20 And has a slanted shape. In other words, the inner surface of the first member 42 is inclined at an inclination angle equal to the outer surface inclination angle of the rotor 20 having the truncated cone-shaped outer shape. This is because, in order to induce the eddy current, it is advantageous that the distance between the heating surfaces of the permanent magnet 24 and the heating element 40 is parallel to the distance control. In addition, when the inner surface of the first member 42, that is, the heat generating surface is in a straight line shape without an angle, the size of the rotor 20 must be small. However, if the size of the rotor 20 is small This is because it is easy to control the gap between the rotor 20 and the heat generating surface of the heat generating element 40 so as to adjust the gap left and right.

The second member 44 is inserted and installed so as to have a spiral shape as a whole in the first member 42 so that heat generated from the heat generating surface of the heating member 940 is efficiently absorbed inside the first member 42. [

On the other hand, the heating member 40 is provided with an inlet / outlet unit 60 for receiving and discharging water. For example, the inlet 62 is connected to the upper end (or one side) of the first member 42 And the outflow port 64 may be respectively installed at the lower end (or other side) of the first member 42 of the heating element 40. The inlet port 62 and the outlet port 64 in the input / output unit 60 may comprise a pipe and may include a water supply device (not shown) capable of supplying water into the heating element 40

5 is a perspective view for explaining a heating element of another embodiment of the eddy current induction heating device according to the present invention.

As shown in the drawing, the heating element 40 of this embodiment may be constructed in a structure in which metal pipes are arranged in a spiral shape. At this time, the heating element 40 of the helical pipe structure is provided, for example, so that the upper opening size is larger than the lower opening size. This is to ensure that the inner surface of the rotor 20 and the outer surface of the rotor 20 are spaced in parallel to each other as in the above-described embodiment.

In addition, the heating body 40 of this embodiment is provided with the inlet 62 at the upper end (or one side) thereof and the outlet 64 at the lower end (or the other side) thereof.

The actuator 50 in the eddy current induction heating apparatus 100 according to the present invention is provided for moving the rotor 20 and is connected to the rotor 20 to rotate the rotor 20 20 so as to insert the rotor 20 into the inside of the inner surface of the heating element 40.

Specifically, the actuator 50 includes a connecting shaft 78 connected to the rotor 20, and the connecting shaft 78 passes through the heating element 40 at a lower portion of the heating element 40, . Here, the structure and structure of the actuator 50 can be understood to be the same as or similar to that of the conventional actuator 50, and thus detailed description and description thereof will be omitted in the present invention.

The actuator 50 moves the rotor 20 according to a control signal of a control unit (not shown) according to a signal output from the rotation speed sensing encoder 30. [ The rotor 20 rotates in a state of being separated from the heating element 40 in the initial low speed section in which the rotor 20 starts to rotate and in the high speed rotation section of the rotor 20, The rotor 20 is moved so that the outer surface of the rotor 20 is completely surrounded by the heating element 40. [

Since the rotor 20 is separated from the heating element 40 in the initial low speed section where the rotation of the rotor 20 is started, the input portion to be applied to the motor 10 for rotating the rotor 20 is not large The temperature of the surface of the heating element 40 is very high because the rotor 20 is close to the heating element 40 and is completely surrounded by the heating element 40 in a high speed section where the rotation speed of the rotor 20 is high. On the other hand, it may be a low input load applied to the motor 10.

Therefore, the eddy current induction heating apparatus 100 according to the present invention is designed such that the gap between the rotor 20 and the heating element 40 is adjusted to be in accordance with the relation between the surface heating temperature of the heating element 40 and the rotational efficiency of the rotor 20 Automatic control can be made to enable application of a low input load.

Although not shown, the eddy current induction heating apparatus 100 according to the present invention further includes a controller for controlling the operation of the actuator 50 according to a signal output from the rotation speed sensing encoder 30, As described above, the operation of the actuator 50 is controlled by this control unit, and consequently, the movement of the rotor 20 is controlled by the control unit.

Hereinafter, the operation of the eddy current induction heating apparatus according to the present invention as described above will be briefly described with reference to FIGS. 1 and 2. FIG.

First, when the motor 10 is rotated, the second pulley 74-2 and the second rotation shaft 72-2 are rotated via the first rotation shaft 72-1 and the first pulley 74-1 and the belt 76, The rotation speed of the rotor 20 is accelerated more than the rotation speed of the motor 10 in this process.

When the rotor 20 is rotated while the outer surface of the rotor 20 is surrounded by the metal material, that is, the heat generating element 40, in the initial low speed section in which the rotor 20 starts rotating, Since the magnitude of the eddy-current brake interfering with the rotation of the electron 20 is large, the load of the input load, i.e., the input energy applied to rotate the rotor 20, must be increased.

On the other hand, if the outer surface of the rotor 20 is not wrapped with the heating body 40 made of a metal, even if the rotor 20 rotates, the eddy current brake that interferes with the rotation of the rotor 20 is not The rotor 20 can be sufficiently rotated even with a low input load.

Therefore, in the eddy current induction heating apparatus according to the present invention, as shown in FIG. 1, in the initial low speed section of the rotor 20, the rotor 20 is disposed apart from the heating element 40, It is possible to rotate the rotor 20 sufficiently even with a low input load by preventing the electrons 20 from being disposed inside the cylindrical heating element 40. [

When the rotor reaches the high speed section through the initial low speed section through sensing the rotor rotation speed of the encoder 30 for detecting the rotation speed, the controller (not shown) The actuator 20 connected to the rotor 20 is operated and the rotor 20 is automatically moved to approach the heating element 40 by the operation of the actuator 50. Finally, 2, the rotor 20 is positioned inside the heating element 40 so that the outer surface of the rotor 20 is surrounded by the heating element 40, as shown in Fig. At this time, since the rotational speed of the rotor 20 is high, the force of the eddy current brake that interferes with the rotation of the rotor 20 is not large, so that the input load also becomes small.

Therefore, the eddy current induction heating device 100 according to the present invention is configured such that the rotor 20 is surrounded by the heating element in the high speed section of the rotor 20 through the installation of the encoder 30 and the actuator 50 The high temperature heat of the heating element 40 can be generated through the generation of sufficient eddy current even with a low input load.

While the present invention has been particularly shown and described with reference to particular embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be readily apparent to those skilled in the art that modifications and variations can be effected by those skilled in the art.

10: motor 20: rotor
22: metal ring 24: permanent magnet
26: housing 30: encoder for detecting rotation speed
40: heating element 42: first member
44: second member 50: actuator
60: I / O unit 62:
64: Outlet port 72-1:
72-2: second rotation shaft 74-1: first pulley
74-2: second pulley 76: belt
78: Connection axis

Claims (7)

A motor as a power source;
A rotor rotated by the motor and including a permanent magnet;
A rotation speed sensing encoder plate installed to sense the rotation speed of the rotor;
A heating element disposed adjacent to the rotor, the heating element having an upper surface and a lower surface opened;
An actuator connected to the rotor through the heating element and changing the position of the rotor according to a signal output from the rotation speed sensing encoder plate; And
An inlet / outlet unit for receiving and discharging water inside the heating element;
/ RTI >
The rotor rotates in a state where the rotor is separated from the heating element in an initial low speed section in which the rotor starts to rotate by sensing the rotation speed of the rotor by the rotation speed sensing encoder plate, And in the high speed section, the rotor is automatically rotated through the operation of the actuator so as to be disposed inside the heating element.
The method according to claim 1,
A first rotating shaft connected to the motor;
A first pulley mounted on the first rotation shaft;
A second rotating shaft connected to the rotor;
A second pulley mounted on the second rotation shaft; And
A belt installed to connect the first pulley and the second pulley;
Further comprising: an eddy current induction heating device for heating the eddy current induction heating device.
2. The rotor of claim 1,
A truncated cone-shaped metal ring having a hole in its central portion;
A plurality of permanent magnets provided at equal intervals on the outer surface of the metal ring; And
A housing which is sandwiched between the permanent magnets and prevents the permanent magnets from separating from the outer surface of the metal ring;
Wherein the eddy current induction heating device comprises:
The heat generating element according to claim 1,
A first member which has a generally cylindrical ring-type and whose inner surface facing the rotor is inclined so as to be parallel to the outer surface of the rotor; And
A second member inserted and arranged in a spiral structure in the first member;
Wherein the eddy current induction heating device comprises:
The heat generating element according to claim 1,
Characterized in that the metal pipe is spirally arranged as a whole so that its inner surface facing the outer surface of the rotor is arranged to be inclined.
2. The actuator according to claim 1,
Wherein when the rotor reaches a predetermined speed by the rotation speed sensing encoder plate, the rotor is automatically positioned inside the heating element.
The method according to claim 1,
Further comprising a control unit for controlling driving of the actuator according to a signal output from the rotation speed sensing encoder plate.

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