CN102448207A - Induction heating apparatus and control method thereof - Google Patents

Abstract

The invention has provided a induction heating device and its control method, the induction heating device is made up of induction coil and magnetizer, the induction coil can be displaced to the heated object, and the induction coil can heat the heated object after being excited, and the magnetizer is set up in the predetermined position adjacent to induction coil, after exciting the induction coil, can set up the magnetizer in the induction coil near one side of the heated object in order to form the magnetic field and separate the function; or the magnetizer is arranged at one side of the induction coil far away from the heated object so as to form the magnetic field enhancement effect.

Description

Induction heating device and control method thereof

technical field

The invention relates to the technical field of induction heating of a mold, in particular to an induction heating device and a control method thereof which use a magnetizer to control the distribution and strength of a magnetic field.

Background technique

Generally speaking, the factors that have the greatest impact on dynamic mold temperature control are heating speed and heating uniformity. In terms of heating speed, the structure and application of induction heating using induction coils has achieved a very good heating speed and is the most energy-saving. , and the conversion rate can reach more than 95%.

For example, China Taiwan Province Patent Announcement No. 463718 (i.e. U.S. Patent US6,402,501) "Sub-Master Instantaneous Preheating Module Drive Device", which sets the male mold as a sub-mode and a female mode according to the heating system and cooling system The combination allows the male mold to be pushed out of the sub-parting mold in the mold closing stroke and heated quickly. The sub-partition mold is small in size, so it warms up quickly, and its heating system uses a high-frequency induction heating coil to be packaged with ceramic blocks or plastic steel soil. As a result, the eddy current installed in the groove of the sub-parting mold can be preheated to the predetermined temperature instantly, so that the preheating time can be shortened and the preheating effect is better.

Another example is Taiwan Province of China Patent Publication No. I228945 (i.e. U.S. Patent US6,919,545) "Method and Device for Promoting the Uniform Distribution of High-frequency Magnetic Force", which utilizes a coil body capable of conducting high-frequency electromagnetic energy to be wound with a high-bottom undulating distribution Regular layered configuration, the adjacent coils are arranged in a non-planar form on a different plane, which can avoid the mutual repulsion and cancellation of the magnetic flux around the two adjacent coils, so as to improve the high-frequency heating magnetic field.

Another example is the Chinese Taiwan Province Patent Announcement No. I224548 (i.e. U.S. Patent No. 6,960,746) "instantaneous mold preheating method and device thereof" invention patent, which establishes a heat conduction coil between a male mold and a female mold, and the heat conduction coil is A coil body capable of conducting high-frequency induction heat energy is wound in a spiral shape. When the male mold and the female mold are separated, they can be moved and moved close to the parting surface of the male mold and the female mold by the mechanical arm , so that the high-frequency induction heat directly acts on the mold core, so as to achieve the purpose of instant preheating of the mold core surface, which not only improves its preheating efficiency, saves electric energy, but also ensures smooth flow of plastic melt in the mold core.

The patented technologies mentioned above all use induction coils to inductively heat the mold, and can achieve the effect of rapid heating. However, another important factor for temperature control of the mold with induction coils is the uniformity of heating. It is a problem still to be overcome.

Since the induction heating of the induction coil is the whole surface, but the object to be heated (such as: mold core) has a non-planar structure, so it is easy to gather magnetism at the corners of the object to be heated, resulting in overheating. Furthermore, the induction coil is usually wound in a helical shape, which tends to cause the problem of low heating temperature at the center of the induction coil, making it difficult to control the heating uniformity.

Therefore, it is necessary to provide a heating method that can meet both the heating speed and the heating uniformity.

Contents of the invention

In view of this, the purpose of the present invention is to provide an induction heating device and its control method, which is equipped with a magnetic conductor on the induction coil, by changing the relative position of the magnetic conductor and the induction coil to strengthen or weaken the magnetic field, and then change the magnetic field Distributed to achieve the effect of improving heating efficiency and uniformity.

In order to achieve the above-mentioned purpose, the induction heating device of the present invention is composed of at least one induction coil and at least one magnetizer, the induction coil can be displaced relative to a heated object, and the induction coil can move the heated object heating is performed, and the magnetic conductor is arranged at a predetermined position adjacent to the induction coil, so as to enhance or block the magnetic field of the induction coil.

And the control method of induction heating device of the present invention, its step comprises:

disposing at least one induction coil adjacent to an object to be heated;

disposing at least one magnetizer at a predetermined position adjacent to the induction coil;

energize the induction coil; and

The magnetic field distribution after the induction coil is excited is enhanced or blocked by the position of the magnetic conductor.

Thereby, the magnetizer is arranged on the side of the induction coil adjacent to the object to be heated, so that the magnetizer attracts the magnetic force lines of the induction coil close to the magnetizer, so that part of the magnetic force lines cannot be transmitted to the heated object to form a barrier effect; Or set the magnetizer on the side of the induction coil away from the object to be heated, so that the magnetizer is magnetized by the magnetic field lines of the induction coil, and strengthen the magnetic field of the induction coil corresponding to the magnetizer toward the object to be heated, thereby forming a magnetic field enhancement effect.

In a preferred embodiment, the object to be heated is a mold core, and the mold core is set in a mold.

In a preferred embodiment, the magnetic conductor is made of magnetic powder core.

In a preferred embodiment, the magnetic conductor is made of soft magnetic material.

In a preferred embodiment, the thickness of the magnetic conductor is greater than 3 mm.

In a preferred embodiment, the thickness of the magnetic conductor is preferably greater than 5 mm.

In a preferred embodiment, the object to be heated has at least one corner portion, and the corner portion is formed by a portion where the distance between the object to be heated and the induction coil varies, and the aforementioned magnetizer is arranged on the induction coil The side adjacent to the object to be heated corresponds to the position of the corner, so as to generate a magnetic field blocking effect on the corner.

In a preferred embodiment, the induction coil is wound in a spiral shape, and the aforementioned magnetizer is arranged on the side of the induction coil away from the object to be heated corresponding to the central part of the induction coil, so that the induction coil The central part produces a magnetic field enhancement effect.

Compared with the prior art, in the induction heating device and its control method described in the present invention, a magnetizer is arranged on the induction coil, and the magnetic field is strengthened or weakened by changing the relative position of the magnetizer and the induction coil, thereby changing the direction of the magnetic field. Distributed to achieve the effect of improving heating efficiency and uniformity.

The detailed features and advantages of the present invention are described in detail below in the embodiments, the content of which is sufficient to enable any person familiar with the relevant art to understand the technical content of the present invention and implement it accordingly, and according to the content disclosed in this specification, the patent scope of the application and the illustrations , anyone skilled in the relevant art can easily understand the related objects and advantages of the present invention.

Description of drawings

Fig. 1 is the structural representation of induction heating device of the present invention;

Fig. 2 is the flowchart of the control method of induction heating device;

Fig. 3 is the schematic diagram that the present invention applies the magnetic conduction principle to change the position of the magnetizer to block the magnetic field; and

Fig. 4 is a schematic diagram of applying the principle of magnetic conduction to change the position of the magnetic conduction body to increase the magnetic field in the present invention.

Explanation of reference numerals: induction heating device-1; induction coil-10; magnetizer-2; object to be heated-3; mold core-3A; mold cavity-31; Steps in the method of inventing magnetic field control.

Detailed ways

The preferred embodiments of the present invention are described in detail below with reference to the drawings.

Please refer to Fig. 1 to Fig. 4, Fig. 1 is the structure diagram of the induction heating device of the present invention; Fig. 2 is the flowchart of the control method of the induction heating device; A schematic diagram of the magnetic field; FIG. 4 is a schematic diagram of the present invention applying the principle of magnetic permeability to change the position of the magnetic conductor to increase the magnetic field.

Please refer to Fig. 1 at first, the induction heating device 1 of the present invention is made up of an induction coil 10 and a magnetizer 2, and this induction coil 10 can be displaced relative to a heated object 3 (such as: the core in the mould), And the induction coil 10 can heat the heated object 3 after being excited, and the magnetic conductor 2 is arranged at a predetermined position adjacent to the induction coil 10 to enhance or block the magnetic field of the induction coil 10 .

Please refer to Fig. 2, which is a flow chart representing the control method of the induction heating device of the present invention; the steps of the control method of the induction heating device of the present invention include:

Step S1: setting the induction coil 10 adjacent to a heated object 3;

Step S2: disposing the magnetizer 2 at a predetermined position adjacent to the induction coil 10;

Step S3: Exciting the induction coil 3; and

Step S4: Use the position of the magnetic conductor 2 to enhance or block the magnetic field distribution of the induction coil 10 after being excited, so as to achieve the effect of uniform heating.

In this embodiment, an induction coil and a magnetic conductor are used as an example for illustration, but it is not limited to this. In practical applications, an induction coil can also be matched with several magnetic conductors, or multiple The induction coil is matched with a plurality of magnetizers; and the aforementioned object to be heated 3 can be a mold core 3A (as shown in Figure 3 ) that is arranged on a mold (not shown in the figure); and the magnetizer 2 is made of magnetic powder The core or soft magnetic material is made of blocks, sheets, etc. in the desired shape; and the thickness of the magnetic conductor 2 is preferably more than 3 mm, and more than 5 mm.

The position of the magnetic conductor 2 can be varied according to the requirement of the magnetic field distribution, so as to control the distribution of the magnetic field and the heating effect on the object to be heated 3 .

Please refer to FIG. 3 , which is a schematic diagram of the present invention applying the principle of magnetism to change the position of the magnetizer to block the magnetic field. When the object to be heated 3 is a mold core 3A, since the mold cavity 31 will be set in the mold core 3A, the distance between the object to be heated 3A and the induction coil 10 will change at the depth change of the mold cavity 31, thereby forming One corner 32, in order to prevent the corner 32 from being overheated due to the corner effect (EndEffect.) during the induction heating process, the aforementioned magnetizer 2 can be arranged on the side of the induction coil 10 adjacent to the heated object 3 Corresponds to the position of the corner portion 32 . In this way, the magnetic force lines of the induction coil 10 close to the magnetic conductor 2 will be attracted by the magnetic conductor 2 so that part of the magnetic force lines cannot be transmitted to the heated object 3. Compared with the magnetic force lines of other parts of the induction coil 10, the adjacent magnetic conductors Only a small part of the magnetic field lines of 2 is transmitted to the heated object 3, so as to block the heating efficiency of the heated object 3 corresponding to the magnetizer 2, thereby forming a blocking effect.

Please refer to FIG. 4 again, which is a schematic diagram of the present invention applying the principle of magnetic conduction to change the position of the magnetic guide to increase the magnetic field. Since the induction coil 10 is usually wound in a helical shape, a weaker magnetic field will be formed in the central part of the induction coil 10, which will affect the heating uniformity of the heated object 3, so the magnetic conductor 2 can be arranged At the central position of the induction coil 10 on the side away from the heated object 3 . In this way, the magnetic force lines of the induction coil 10 adjacent to the magnetizer 2 will be attracted by the magnetizer 2, and because the magnetizer 2 is arranged on the side of the induction coil 10 away from the object to be heated 3, the magnetizer 2 will be attracted by the induction coil After the magnetic field lines of 10 are magnetized, the magnetic field of the induction coil 10 corresponding to the magnetizer 2 towards the heated object 3 can be strengthened, so that the magnetic field distribution of the entire induction coil 10 is more uniform, and the heating of the heated object 3 by the induction coil 10 can be improved. Spend.

In short, if the magnetic conductor is arranged on the side of the induction coil adjacent to the object to be heated, a magnetic field blocking effect can be produced; if the magnetic conductor is arranged on the side of the induction coil away from the object to be heated, it can produce Magnetic field enhancement effect. Therefore, in practical applications, the position of the magnetizer can be changed and adjusted according to the heating requirements of the object to be heated, so as to achieve multiple functions of controlling the magnetic field distribution, heating efficiency, and heating uniformity.

To sum up, what is described above is only a description of the preferred implementation mode or example of the technical means adopted by the present invention to solve the problems, and is not intended to limit the scope of the patent implementation of the present invention. That is, all equivalent changes and modifications that are consistent with the scope of the patent application of the present invention, or made according to the scope of the patent of the present invention, are covered by the scope of the patent of the present invention.

Claims (14)

1. An induction heating device, characterized in that it comprises: an induction coil displaced relative to a heated object, and the induction coil is excited to heat the heated object; and At least one magnetic conductor is arranged at a predetermined position adjacent to the induction coil. 2. The induction heating device according to claim 1, wherein the object to be heated is a mold core, and the mold core is arranged in a mold. 3 . The induction heating device according to claim 1 , wherein the magnetic conductor is a block or a sheet made of a magnetic powder core. 4 . 4. The induction heating device according to claim 1, characterized in that the magnetic conductor is a block or sheet made of soft magnetic material. 5 . The induction heating device according to claim 1 , wherein the magnetic conductor is disposed at a predetermined position on a side of the induction coil adjacent to the object to be heated. 5 . 6 . The induction heating device according to claim 1 , wherein the magnetic conductor is disposed at a predetermined position on a side of the induction coil away from the object to be heated. 6 . 7. The induction heating device as claimed in claim 1, wherein the thickness of the magnetic conductor is greater than 3 mm. 8. The induction heating device as claimed in claim 1, wherein the thickness of the magnetic conductor is greater than 5mm. 9. The induction heating device according to claim 1, wherein the object to be heated has at least one corner portion, and the corner portion is formed by a portion where the distance between the object to be heated and the induction coil varies, and The said magnetizer is arranged corresponding to the corner. 10 . The induction heating device as claimed in claim 1 , wherein the induction coil is wound in a helical shape, and the magnetic conductor is disposed at a central part of the induction coil. 11 . 11. A control method for an induction heating device, characterized in that the steps include: disposing at least one induction coil adjacent to an object to be heated; disposing at least one magnetizer at a predetermined position adjacent to the induction coil; energize the induction coil; and The magnetic field distribution after the induction coil is excited is enhanced or blocked by the position of the magnetic conductor. 12 . The control method of the induction heating device according to claim 11 , wherein the magnetizer is arranged at a predetermined position on a side of the induction coil adjacent to the object to be heated to generate a magnetic field blocking effect. 13 . 13. The control method of the induction heating device according to claim 11, wherein the object to be heated has at least one corner portion, and the corner portion is formed at a portion where the distance between the object to be heated and the induction coil varies , and the aforementioned magnetizer is disposed corresponding to the corner portion. 14 . The control method of the induction heating device according to claim 11 , wherein the magnetizer is arranged at a predetermined position on the side of the induction coil away from the object to be heated to generate a magnetic field enhancement effect. 15 .

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