JP2014107091A - Induction heating apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an easy-to-handle induction heating apparatus in which leakage of magnetic flux to the surrounding can be reduced, and the weight of an induction heating coil is reduced by improving the support structure thereof.SOLUTION: An induction heating apparatus includes an induction heating coil 10 formed by winding a coil conductor 11 cylindrically, and a coil support configured by arranging a plurality of rod-like support members 16, formed of a heat-resistant insulating material, at equal intervals on the periphery while directing the length direction vertically. The induction heating coil is supported by the coil support, and a heat insulation part is formed by sandwiching a heat resistant heat insulation material 21 between the support members of the coil support, on the inside of the induction heating coil.

Description

  The present invention relates to an induction heating apparatus for heating a metal part, a casting forging die, and the like by induction heating.

  Heating of metal parts for surface modification and removal of thermal distortion and heating for preheating of a casting and forging die are generally performed by putting these objects to be heated in a gas combustion furnace. However, in such a gas combustion furnace, the flow of high-temperature air is not uniform, it is difficult to uniformly heat the entire metal part such as a mold, the heating time is long, and the heating efficiency is high. There are problems such as bad things.

  On the other hand, as shown in Patent Documents 1 and 2, an induction heating coil is disposed around a metal part such as a mold for casting and forging, and a high-frequency current is passed through the induction heating coil. If induction heating is performed on the metal part, the entire metal part such as a mold can be heated to a uniform temperature and can be efficiently heated, so that such a problem can be solved. .

  In an induction heating apparatus using such metal parts such as a mold for heating, as shown in FIG. 6, a coil conductor 11 wound in a cylindrical shape is embedded in a cylindrical support 12 made of heat-resistant cement. Conventional induction heating coils have been used. Reference numerals 13 and 14 are connection terminals for connecting the coil conductor to a high-frequency power source. According to this apparatus, since a metal part such as a mold is placed in the hollow space of the induction heating coil 10 and induction heating is performed, the entire metal part can be uniformly heated in a short time. However, in this structure, since the coil conductor 11 is held by the support body 12 made of heat-resistant cement, the weight becomes heavy and handling becomes inconvenient.

Japanese Patent Laid-Open No. 05-076978 JP 2002-361353 A

  An object of the present invention is to improve the support structure of the induction heating coil in order to solve the problems in the conventional apparatus described above, the weight of the induction heating coil is light, easy to handle, and leakage to the surroundings. An object of the present invention is to provide an induction heating device capable of reducing magnetic flux.

  In order to solve the above-described problems, the present invention provides an induction heating coil configured by winding a coil conductor in a cylindrical shape, and a plurality of rod-shaped support members formed of a heat-resistant insulating material on the circumference. A coil support portion configured by arranging the length directions perpendicularly at intervals, and supporting the induction heating coil by the coil support portion, and between the support members of the coil support portion inside the induction heating coil A heat insulating part is formed by sandwiching a heat resistant heat insulating member.

  In this invention, the width of each support member of each of the coil support portions is widened inwardly every other one, and the heat-resistant heat insulation member is sandwiched between the wide support members to form the heat insulation portion. Can be formed. It is preferable that the heat-resistant heat insulating member has a flexible structure formed by packing a fine inorganic heat-insulating material in a flexible bag formed of a heat-resistant fiber material.

  In the present invention, a magnetic shielding plate can be formed by sandwiching a magnetic shielding plate between support members of the coil supporting portion outside the induction heating coil, and the magnetic shielding plate is a tile-shaped piece. The magnetic shielding plates can be arranged in one row at intervals, and the arrangement of each row can be staggered so that the whole becomes a staggered arrangement.

  Further, the induction heating coil is preferably wound so that the distance between the coil conductors becomes narrow at the upper and lower end portions of the induction heating coil in order to make the magnetic flux portion distribution in the induction heating coil uniform.

  Furthermore, when the metal part which is a to-be-heated object arrange | positioned inside the said induction heating coil is divided | segmented into plurality, it is good to arrange | position the said some metal parts, providing a clearance gap, respectively.

  According to the present invention, the induction heating coil is supported by the plurality of rod-shaped support members formed of a heat-resistant insulating material, and the heat insulating portion is formed inside the induction heating coil, so that the weight of the induction heating device is light. Thus, the magnetic flux can be easily reduced and leakage flux to the surroundings can be reduced by forming a magnetic shielding portion by sandwiching a magnetic shielding plate between the support members on the outer peripheral side of the induction heating coil.

The top view of the induction heating apparatus by the Example of this invention. The front view. FIG. 3 is a longitudinal sectional view taken along line III-III in FIG. 1. The longitudinal cross-sectional view which follows the IV-IV line in FIG. FIG. 5 is a cross-sectional view taken along line VV in FIG. 3. The perspective view containing the cross section of the induction heating coil of the conventional induction heating apparatus.

  Embodiments of the present invention will be described with reference to the embodiments shown in the drawings.

  1 to 5 show the configuration of each part of an induction heating apparatus according to an embodiment of the present invention.

  In these drawings, reference numeral 10 denotes an induction heating coil, which is formed by winding a coil conductor 11 such as a litz wire horizontally or spirally in a cylindrical shape. The coil conductor 11 wound in a cylindrical shape has excellent strength, such as engineering plastic, and is supported by a plurality of rectangular rod-shaped coil support members 16a and 16b formed of a nonmagnetic heat-resistant insulating material. The support members 16 a and 16 b are arranged on the circumference concentric with the induction heating coil 10 at equal intervals with the length (height) direction being vertical (vertical) to constitute the coil support portion 16. The plurality of support members arranged on the circumference include a wide support member 16a having a radial width W as Wa and a narrow support member 16b having a width W as Wb. Wide support members 16a and narrow support members 16b are alternately arranged so that the positions of the outer peripheral ends of all the support members are aligned on the same circumference (see FIGS. 1 and 5).

  A plurality of holding grooves 16c and 16d for holding the plurality of coil conductors 11 are provided on the inner peripheral end sides of the support members 16a and 16b. The holding groove 16c of the wide support member 16a is formed deep from the inner peripheral end surface and is formed shallower from the inner peripheral end surface of the holding support groove 16d of the narrow support member 16b so that the coil conductor 11 is supported at the same position. Is done. The coil conductor 11 is held by being pushed to a position in contact with the innermost peripheral wall of the holding grooves 16c and 16d. In the induction heating coil 10 supported by inserting the coil conductor 11 into the holding grooves 16c and 16d of the support members 16a and 16b in this way, the interval between the coil conductors 11 is narrow at the upper and lower ends in the height direction, It is wound so as to be wide at the part (see FIG. 4).

  Here, when the coil conductor 11 is spirally wound, the holding grooves 16c and 16d of the support members 16a and 16b are provided at different intervals in the height (vertical) direction according to the coil conductor 11. By horizontally winding the support members 16a and 16b, the holding grooves 16c and 16d have the same height (same height) as the holding grooves 16c and 16d, and the processing cost of the support members 16a and 16b can be reduced.

  The plurality of support members 16a and 16b that support the coil conductor 11 are fitted and coupled at their upper and lower ends to annular end plates 17a and 17b formed of the same nonmagnetic heat-resistant insulating material as the support member. Are connected to each other and integrated (see FIG. 4).

  Further, on the outer peripheral side of the induction heating coil 10, a plurality of magnetic shielding plates 18 laid into tile-shaped pieces by ferrite, for example, are fitted between the support members 16 a and 16 b at a predetermined interval, and an adhesive is used. It is supported by the support members 16a and 16b by adhering with the like. The magnetic shielding plates 18 in each row are arranged alternately with the magnetic shielding plates 18 in adjacent rows, and as a whole, the arrangement is in a staggered pattern as shown in FIG. In FIG. 2, the magnetic shielding plate 18 is not shown in section but is hatched in order to make the distinction between the void and the magnetic shielding plate 18 clear.

  Since the magnetic shielding plate 18 is arranged in a staggered pattern on the outer periphery of the induction heating coil 10 as described above, a portion where the magnetic shielding plate 18 is missing is generated at the upper and lower ends as shown in FIG. As described above, the magnetic shielding plate 19 made of ferrite or the like is disposed on the upper and lower end portions of the induction heating coil 10 above the lacked portion of the magnetic shielding plate 18 and on the lower end plates 17a and 17b. As a result, the magnetic flux distribution at the upper and lower ends of the induction heating coil 10 can be made more uniform, and leakage of the magnetic flux to the outside can be reduced. Moreover, if the coil conductor 11 is wound horizontally, the loss at the upper and lower ends of the coil can be reduced.

  On the inner peripheral side of the induction heating coil 10, fine inorganic particles are formed in a flexible bag formed of a heat resistant fiber material such as glass fiber between the wide support members 16 a. A heat insulating wall is formed by sandwiching and fixing a non-magnetic heat insulating member 21 which is configured by filling a heat insulating material and which is relatively free of deformation. Thereby, it becomes the heat processing space 20 with which the inside of the induction heating coil 10 was insulated (refer FIG. 5). When the heat insulating member 21 is configured by filling a bag made of heat insulating fiber material with a fine-grained inorganic heat insulating material, the degree of freedom of deformation of the heat insulating member 21 is increased. Becomes easy.

  In the induction heating apparatus having the induction heating coil 10 of the present invention configured as described above, a metal part such as a casting forging die as a heated object is inserted into the heat treatment space 20 in the induction heating coil 10. By arranging and connecting the connection terminals 13 and 14 to a high frequency power source and supplying a high frequency current to the induction heating coil 10, it is possible to heat the metal parts in the heat treatment space 20 by flowing an induction current.

  Since the metal part is heated by the induced current, the whole can be heated uniformly and efficiently. And since the outer periphery of the heat treatment space 20 is thermally insulated by the heat insulating member 21 and the support member 16, heat radiation from the space to the outside can be suppressed, so that the thermal efficiency can be increased.

  Here, when a metal part such as a mold, which is an object to be heated set in the heat treatment space 20 in the induction heating coil 10, is configured with a structure (for example, a split structure) divided into a plurality of parts. Try to place the two metal parts slightly apart. By providing a gap between the two metal parts in this way, an induced current flows through each metal part, and the entire two metal parts can be heated to a uniform temperature. When two metal parts are placed in contact with each other, an inductive current concentrates on the contacted part, and troubles such as sparking and welding may occur.

  In addition, the induction heating coil 10 of the present invention is supported by a support member 16 formed of a plurality of heat-resistant insulating materials without being encased in fireproof cement, and an inorganic heat insulating material is provided between each supporting member on the inner peripheral side. A heat-insulating member made of a heat-resistant fiber material and packed in a flexible bag is fitted, and the outer peripheral side is made up of a tile-shaped magnetic shielding plate fitted between the support members, and the coil support member is guided. Since not only the heating coil but also the heat insulating part and the magnetic shielding part are supported, the induction heating device can be made small and light. For this reason, the weight can be greatly reduced as compared with the conventional induction heating apparatus configured by wrapping the induction heating coil with refractory cement, and handling becomes easy.

  Furthermore, the magnetic flux leaking to the outside from the induction heating coil 10 is absorbed by the magnetic shielding plates 18 and 19 disposed on the outer peripheral portion, and the leakage magnetic flux to the outside can be reduced. Since this magnetic shielding plate 18 is arranged in a staggered pattern, many voids are formed on the outer periphery of the induction heating coil 10, and the coil conductor 11 forming the induction heating coil 10 is cooled by direct contact with the outside air. Therefore, the cooling effect of the induction heating coil can be enhanced, and the capacity of the induction heating coll can be increased.

  In the above-described embodiment of the present invention, the support grooves 16c and 16d for supporting the coil conductor are provided on the inner peripheral surface side of the rectangular rod-shaped coil support members 16a and 16b for supporting the coil conductor. It is also possible to provide and support the coil conductor 11 from the inner peripheral side.

  Moreover, in the said Example, although the induction heating coil 10 demonstrated the coil conductor 11 wound by the cylinder shape as an example, it was induced | guided | derived by the coil conductor wound by polygonal cylinder shapes, such as a square cylinder shape. The heating coil 10 may be configured.

10: induction heating coil 11: coil conductor 13, 14: connection terminal 16 (16a, 16b): coil support member 18, 19: magnetic shielding plate 20: heat treatment space 21: heat insulating member

Claims (7)

  An induction heating coil configured by winding a coil conductor in a cylindrical shape and a plurality of rod-shaped support members formed of a heat-resistant insulating material are arranged at equal intervals on the circumference with the length direction being vertical. A coil support portion configured to support the induction heating coil by the coil support portion, and form a heat insulating portion by sandwiching a heat-resistant heat insulating material between support members of the coil support portion inside the induction heating coil. An induction heating device characterized by that.   The inner and outer direction widths of the respective coil support members are widened inwardly, and the heat-resistant and heat-insulating material is sandwiched between the widened coil support members to form a heat insulating portion. 2. The induction heating apparatus according to 1.   3. The induction heating according to claim 1, wherein the heat-resistant heat insulating material is configured to be freely deformed by packing a fine-grained inorganic heat insulating material in a flexible bag formed of a heat-resistant fiber material. apparatus.   The induction heating apparatus according to any one of claims 1 to 3, wherein a magnetic shielding part is formed by sandwiching a magnetic shielding plate between support members of the coil support part outside the induction heating coil.   A tile-shaped small piece of magnetic shielding plate is used as the magnetic shielding plate, and the small pieces of magnetic shielding plates are arranged in one row at intervals between the coil support members. The induction heating apparatus according to claim 4, wherein the induction heating apparatus is arranged in a staggered pattern so as to be staggered.   The coil conductor is wound so that the interval between the coil conductors supported by the coil support portion becomes narrower at the upper and lower end portions of the induction heating coil and becomes wider at the intermediate portion. The induction heating apparatus according to item 1.   2. The structure of claim 1, wherein the plurality of metal parts are arranged with gaps when the metal parts, which are objects to be heated, arranged on the inner peripheral side of the induction heating coil are divided into a plurality of parts. The induction heating device according to any one of -6.

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