CN110557855B - Heating coil unit and induction heating cooker having the same - Google Patents
Heating coil unit and induction heating cooker having the same Download PDFInfo
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- CN110557855B CN110557855B CN201910467289.0A CN201910467289A CN110557855B CN 110557855 B CN110557855 B CN 110557855B CN 201910467289 A CN201910467289 A CN 201910467289A CN 110557855 B CN110557855 B CN 110557855B
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B6/00—Heating by electric, magnetic or electromagnetic fields
- H05B6/02—Induction heating
- H05B6/10—Induction heating apparatus, other than furnaces, for specific applications
- H05B6/12—Cooking devices
- H05B6/1209—Cooking devices induction cooking plates or the like and devices to be used in combination with them
- H05B6/1245—Cooking devices induction cooking plates or the like and devices to be used in combination with them with special coil arrangements
- H05B6/1254—Cooking devices induction cooking plates or the like and devices to be used in combination with them with special coil arrangements using conductive pieces to direct the induced magnetic field
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B6/00—Heating by electric, magnetic or electromagnetic fields
- H05B6/02—Induction heating
- H05B6/06—Control, e.g. of temperature, of power
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B6/00—Heating by electric, magnetic or electromagnetic fields
- H05B6/02—Induction heating
- H05B6/10—Induction heating apparatus, other than furnaces, for specific applications
- H05B6/12—Cooking devices
- H05B6/1209—Cooking devices induction cooking plates or the like and devices to be used in combination with them
- H05B6/1245—Cooking devices induction cooking plates or the like and devices to be used in combination with them with special coil arrangements
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B6/00—Heating by electric, magnetic or electromagnetic fields
- H05B6/02—Induction heating
- H05B6/10—Induction heating apparatus, other than furnaces, for specific applications
- H05B6/12—Cooking devices
- H05B6/1209—Cooking devices induction cooking plates or the like and devices to be used in combination with them
- H05B6/1245—Cooking devices induction cooking plates or the like and devices to be used in combination with them with special coil arrangements
- H05B6/1272—Cooking devices induction cooking plates or the like and devices to be used in combination with them with special coil arrangements with more than one coil or coil segment per heating zone
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B6/00—Heating by electric, magnetic or electromagnetic fields
- H05B6/02—Induction heating
- H05B6/36—Coil arrangements
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B6/00—Heating by electric, magnetic or electromagnetic fields
- H05B6/02—Induction heating
- H05B6/36—Coil arrangements
- H05B6/44—Coil arrangements having more than one coil or coil segment
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B2203/00—Aspects relating to Ohmic resistive heating covered by group H05B3/00
- H05B2203/022—Heaters specially adapted for heating gaseous material
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- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Induction Heating Cooking Devices (AREA)
Abstract
Heating coil unit and induction heating cooker having the same. In a heating coil unit of an induction heating cooker having a first heating coil and a second heating coil, heating power capable of suppressing heat generation and enlargement and performing induction heating on a cooking container made of a non-magnetic material can be realized. The heating coil unit (16) has first and second heating coils (22, 24) and a plurality of ferrites (26-36). The plurality of ferrites includes a common ferrite (34), and the common ferrite (34) surrounds adjacent portions (22 a) of the first heating coils (22) and adjacent portions (24 a) of the second heating coils (24) adjacent to each other in a state in which the upper portions thereof are open.
Description
Technical Field
The present invention relates to a heating coil unit and an induction heating cooker having the same.
Background
Conventionally, as a heating coil unit of an induction heating cooker for induction heating a cooking container in which a heating object is housed, a technique having a plurality of heating coils is known as described in patent document 1, for example. By selectively using a plurality of heating coils, the heating force (generated magnetic force) for the cooking container can be finely adjusted as compared with a heating coil unit having only one heating coil. In the case of the heating coil unit described in patent document 1, ferrite is disposed between the heating coils as a magnetic shielding unit so that the magnetic field generated from one heating coil does not affect the other heating coil.
Patent document 1: japanese patent laid-open No. 1-246782
However, induction heating of a cooking container made of a nonmagnetic material such as aluminum or copper is desired. Therefore, it is considered to flow a large current in the heating coil or to increase the number of turns of the heating coil. However, in this case, the heating coil itself becomes high in temperature and becomes large in size. As a result, the heating coil unit generates heat and increases in size.
Disclosure of Invention
Accordingly, an object of the present invention is to provide a heating coil unit of an induction heating cooker having a first heating coil and a second heating coil, which can suppress heat generation and increase in size, and which can realize heating power capable of induction heating a cooking container made of a nonmagnetic material.
In order to solve the above problems, according to one aspect of the present invention, there is provided a heating coil unit including:
a first heating coil and a second heating coil; and
a plurality of the ferrite elements are arranged in a plurality of the ferrite elements,
the plurality of ferrites includes a common ferrite that surrounds adjacent portions of the first heating coil and adjacent portions of the second heating coil adjacent to each other in a state where the common ferrite is open at an upper side.
In addition, according to another aspect of the present invention, there is provided an induction heating cooker including:
a top plate; and
a heating coil unit disposed below the top plate,
the heating coil unit has:
a first heating coil and a second heating coil; and
a plurality of the ferrite elements are arranged in a plurality of the ferrite elements,
the plurality of ferrites includes a common ferrite, and the common ferrite surrounds adjacent portions of the first heating coil and the second heating coil adjacent to each other in a state where the common ferrite is opened upward.
According to the present invention, in a heating coil unit of an induction heating cooker having a first heating coil and a second heating coil, heating power that can suppress heat generation and increase in size and also perform induction heating of a cooking container made of a nonmagnetic material can be realized.
Drawings
Fig. 1 is a perspective view of an induction heating cooker according to an embodiment of the present invention.
Fig. 2 is a perspective view of the heating coil unit.
Fig. 3 is an exploded perspective view of the heating coil unit.
Fig. 4 is a perspective view showing the arrangement relationship of the first heating coil, the second heating coil, and the plurality of ferrites in the heating coil unit.
Fig. 5 is a plan view showing the arrangement relationship of the first heating coil, the second heating coil, and the plurality of ferrites in the heating coil unit.
Fig. 6 is a perspective view of the first ferrite and the third ferrite.
Fig. 7 is a perspective view of the second ferrite and the fourth ferrite.
Fig. 8 is a schematic diagram showing a magnetic field generated in the heating coil.
Fig. 9 is a perspective view of the common ferrite.
Fig. 10A is a diagram showing a magnetic field distribution of a heating coil unit of an embodiment having a common ferrite.
Fig. 10B is a diagram showing the magnetic field distribution of the heating coil unit of the comparative example having no common ferrite.
Fig. 11 is a perspective view of the auxiliary ferrite.
Description of the reference numerals
16: a heating coil unit; 22: a first heating coil; 22a: adjacent portions (linear portions); 24: a second heating coil; 24a: adjacent portions (linear portions); 26: a first ferrite; 28: a second ferrite; 30: a third ferrite; 32: a fourth ferrite; 34: sharing ferrite; 36: auxiliary ferrite.
Detailed Description
A heating coil unit according to an aspect of the present invention includes a first heating coil, a second heating coil, and a plurality of ferrites, wherein the plurality of ferrites include a common ferrite, and the common ferrite surrounds adjacent portions of the first heating coil and the second heating coil adjacent to each other in a state where the common ferrite is open at an upper side.
According to one aspect of the present invention, in a heating coil unit of an induction heating cooker having a first heating coil and a second heating coil, heating power that can suppress heat generation and increase in size and also can perform induction heating on a cooking container made of a nonmagnetic material can be realized.
The common ferrite may have a shape of a letter コ, for example.
The plurality of ferrites include a first ferrite and a second ferrite which surround a portion of the first heating coil different from the adjacent portion in an open state, and a third ferrite and a fourth ferrite which surround a portion of the second heating coil different from the adjacent portion in an open state, and in this case, the common ferrite preferably has a larger magnetic path cross-sectional area than the first ferrite to the fourth ferrite. This suppresses the common ferrite from being in a high temperature state and also suppresses the generation of magnetic saturation in the common ferrite.
In the first heating coil, a radius of curvature of a portion surrounded by the second ferrite is smaller than a radius of curvature of a portion surrounded by the first ferrite, and in the second heating coil, a radius of curvature of a portion surrounded by the fourth ferrite is smaller than a radius of curvature of a portion surrounded by the third ferrite, in which case the second ferrite preferably has a larger magnetic path cross-sectional area than the first ferrite, and the fourth ferrite preferably has a larger magnetic path cross-sectional area than the third ferrite. This suppresses the second ferrite and the fourth ferrite from being brought into a high-temperature state.
The first to fourth ferrites may be, for example, in the shape of a "コ" character.
The plurality of ferrites may include an auxiliary ferrite having an "L" shape. The magnetic field can be further expanded toward the upper side of the heating coil.
Adjacent portions of the first heating coil and the second heating coil may be linear portions parallel to each other. As a result, the heating power can be further improved.
The first heating coil and the second heating coil may have, for example, a "D" shape.
The interval between adjacent coil lines in the corner portions of the first heating coil and the second heating coil located at both ends of the linear portion may be larger than the interval between coil lines in portions other than the corner portions. Thereby, the magnetic field generated by the first heating coil and the second heating coil can be expanded in the horizontal direction.
An induction heating cooker according to another aspect of the present invention includes: a top plate; and a heating coil unit disposed below the top plate, wherein the heating coil unit includes a first heating coil, a second heating coil, and a plurality of ferrites, wherein the plurality of ferrites include a common ferrite, and wherein adjacent portions of the first heating coil and adjacent portions of the second heating coil adjacent to each other are surrounded together in a state in which the common ferrite is open at an upper side.
According to another aspect of the present invention, in a heating coil unit of an induction heating cooker having a first heating coil and a second heating coil, heating power that can suppress heat generation and increase in size and also perform induction heating on a cooking container made of a nonmagnetic material can be realized.
An embodiment of the present invention will be described below with reference to the drawings.
Fig. 1 shows an induction heating cooker according to an embodiment of the present invention. The X-Y-Z coordinate system shown in the drawings is for aiding understanding of the invention, and is not intended to limit the invention. The X-axis direction and the Y-axis direction represent horizontal directions, and the Z-axis direction represents vertical directions.
As shown in fig. 1, the induction heating cooker 10 is a cooker that induction heats a cooking container C that accommodates a heating target T. The induction heating cooker 10 includes: a top plate 12 for placing the cooking container C, for example, made of heat-resistant glass; and a housing 14 mounted on a lower surface of the top plate 12. A plurality of heating coil units 16 are mounted in the case 14. The plurality of heating coil units 16 are disposed below the top plate 12, respectively, and induction-heat the cooking container C placed on the top plate 12 at portions facing the plurality of heating coil units 16, respectively.
The details of the heating coil unit 16 according to one embodiment of the present invention will be described below.
Fig. 2 is a perspective view of the induction heating coil unit. Fig. 3 is an exploded perspective view of the induction heating coil unit.
As shown in fig. 2 and 3, in the case of the present embodiment, the heating coil unit 16 includes a coil base 20, a first heating coil 22, a second heating coil 24, a plurality of ferrites 26 to 36, and a shielding plate 38. Although not shown, the heating coil unit 16 includes components other than these components, for example, an infrared temperature sensor or the like for detecting the temperature of the cooking container C located above the heating coil unit 16 with the top plate 12 interposed therebetween.
The coil base 20 of the heating coil unit 16 is a member made of, for example, a resin material, and is configured to hold the first heating coil 22, the second heating coil 24, and the plurality of ferrites 26 to 36. Specifically, the coil base 20 has a shallow tray shape having a concave space 20a in which the first heating coil 22 and the second heating coil 24 are accommodated, and the concave space 20a has a plurality of partition walls 20b for holding the first heating coil 22 and the second heating coil 24 (coil wires constituting them). By disposing the coil wire between the adjacent partition walls 20b, the first heating coil 22 and the second heating coil 24 are held by the coil base 20 in a state in which their coil shapes are maintained.
The plurality of ferrites 26 to 36 are mounted on the bottom surface of the coil base 20 in a state where a part (wall portion described later) penetrates into the recess space 20 a.
The first heating coil 22 and the second heating coil 24 are constituted by coil wires which are produced by twisting a plurality of wires such as aluminum wires or copper wires. In the case of the present embodiment, the coil wires are arranged on the coil base 20 such that 9 loops are formed when viewed in the vertical direction (when viewed in the Z-axis direction), and the coil wires are vertically overlapped by five layers.
In the case of the present embodiment, the coil wire is arranged on the coil base 20 such that the first heating coil 22 and the second heating coil 24 are each formed in a "D" shape in the vertical direction (when viewed in the Z-axis direction). That is, the first heating coil 22 and the second heating coil 24 include linear portions 22a, 24a and arcuate portions 22b, 24b, respectively.
The first heating coil 22 and the second heating coil 24 are held by the coil base 20, and thus are arranged in parallel (in the Y-axis direction) with the coil opening facing the vertical direction (Z-axis direction). In the case of the present embodiment, the first heating coil 22 and the second heating coil 24 are arranged adjacent to each other with the linear portions 22a, 24a parallel to each other.
The plurality of ferrites of the heating coil unit 16 include: the first ferrite 26 and the second ferrite 28 used for the first heating coil 22, the third ferrite 30 and the fourth ferrite 32 used for the second heating coil 24, and the common ferrite 34 common to the first heating coil 22 and the second heating coil 24.
In the present embodiment, the first ferrite 26 and the third ferrite 30 have the same shape, and the second ferrite 28 and the fourth ferrite 32 have the same shape. In the case of the present embodiment, the heating coil unit 16 includes the auxiliary ferrite 36 as ferrite other than the first ferrite 26 to the fourth ferrite 32 and the common ferrite 34. Details of these ferrites 26 to 36 will be described.
Fig. 4 is a perspective view showing the arrangement relationship of the first heating coil, the second heating coil, and the plurality of ferrites in the heating coil unit. Fig. 5 is a plan view showing the arrangement relationship of the first heating coil, the second heating coil, and the plurality of ferrites among the heating coils.
As shown in fig. 4 and 5, the first ferrite 26 (third ferrite 30), the second ferrite 28 (fourth ferrite 32), and the common ferrite 34 have different shapes.
Fig. 6 is a perspective view of the first ferrite and the third ferrite. Fig. 7 is a perspective view of the second ferrite and the fourth ferrite.
As shown in fig. 6, in the case of the present embodiment, the first ferrite 26 and the third ferrite 30 have the same shape as described above, and have a shape of a letter コ. Specifically, the first ferrite 26 and the third ferrite 30 have: the present invention is characterized by comprising rectangular parallelepiped main body portions 26a, 30a extending in the horizontal direction (X-axis direction, Y-axis direction), rectangular parallelepiped outer side wall portions 26b, 30b erected in the vertical direction (Z-axis direction) from one ends of the main body portions 26a, 30a, and rectangular parallelepiped center side wall portions 26c, 30c erected in the vertical direction from the other ends.
As shown in fig. 5, a part of the first heating coil 22 is disposed above the main body portion 26a of the first ferrite 26 between the outer side wall portion 26b and the center side wall portion 26 c. Specifically, a part of the coil base 20 is present between the main body portion 26a and the first heating coil 22. The outer side wall 26b is located outside the first heating coil 22, and the center side wall 26c is located on the center side (inside the coil opening) of the first heating coil 22. In other words, the first ferrite 26 surrounds a part of the first heating coil 22 in a state where the upper side is open (a state where the top plate 12 side is open).
As shown in fig. 5, a part of the second heating coil 24 is disposed above the main body portion 30a of the third ferrite 30 between the outer side wall portion 30b and the center side wall portion 30c. Specifically, a part of the coil base 20 is present between the main body portion 30a and the second heating coil 24. The outer side wall portion 30b is located outside the second heating coil 24, and the center side wall portion 30c is located on the center side (inside the coil opening) of the second heating coil 24. In other words, the third ferrite 30 surrounds a part of the second heating coil 24 in a state where the upper side is open (a state where the top plate 12 side is open).
As shown in fig. 7, in the case of the present embodiment, the second ferrite 28 and the fourth ferrite 32 have the same shape as described above, and have a shape of a letter コ. Specifically, the second ferrite 28 and the fourth ferrite 32 have: the present invention is characterized by comprising rectangular parallelepiped main body portions 28a, 32a extending in the horizontal direction (X-axis direction, Y-axis direction), rectangular parallelepiped outer side wall portions 28b, 32b erected in the vertical direction (Z-axis direction) from one ends of the main body portions 28a, 32a, and semi-cylindrical center side wall portions 28c, 32c erected in the vertical direction from the other ends.
As shown in fig. 5, a part of the first heating coil 22 is disposed above the main body portion 28a of the second ferrite 28 between the outer side wall portion 28b and the center side wall portion 28 c. Specifically, a part of the coil base 20 is present between the main body portion 28a and the first heating coil 22. The outer side wall 28b is located outside the first heating coil 22, and the center side wall 28c is located on the center side (inside the coil opening) of the first heating coil 22. In other words, the second ferrite 28 surrounds a part of the first heating coil 22 in a state where the upper side is open (a state where the top plate 12 side is open).
Similarly, as shown in fig. 5, a part of the second heating coil 24 is disposed above the main body portion 32a of the fourth ferrite 32 between the outer side wall portion 32b and the center side wall portion 32c. Specifically, a part of the coil base 20 is present between the main body portion 32a and the second heating coil 24. The outer side wall portion 32b is located outside the second heating coil 24, and the center side wall portion 32c is located on the center side (inside the coil opening) of the second heating coil 24. In other words, the fourth ferrite 32 surrounds a part of the second heating coil 24 in a state where the upper side is open (a state where the top plate 12 side is open).
As shown in fig. 6 and 7, the shape of the first ferrite 26 is different from the shape of the second ferrite 28, and the shape of the third ferrite 30 is different from the shape of the fourth ferrite 32. The reason why the third ferrite 30 and the fourth ferrite 32 are different in shape is the same as the reason why the first ferrite 26 and the second ferrite 28 are different in shape.
As shown in fig. 5, the first ferrite 26 surrounds the arc-shaped portion 22b of the first heating coil 22 in a state where the upper side is open. The second ferrite 28 surrounds the corner portions 22c of the first heating coil 22 located at both ends of the linear portion 22a, i.e., located between the linear portion 22a and the arcuate portion 22b, in a state of being opened upward.
As shown in fig. 5, in the first heating coil 22, when the arc-shaped portion 22b and the corner portion 22c are compared, the radius of curvature of the latter is small. Therefore, the center side wall portion 28c of the second ferrite 28 is formed in a semi-cylindrical shape (semi-circular shape when viewed from above (viewed in the Z direction)) unlike the rectangular parallelepiped center side wall portion 26c of the first ferrite 26 so that the center side wall portion 28c of the second ferrite 28 does not come too close to the first heating coil 22.
In addition, the second ferrite 28 has a larger magnetic path sectional area than the first ferrite 26. This will be specifically described with reference to fig. 8.
Fig. 8 is a schematic diagram showing a magnetic field generated in the first heating coil.
As shown in fig. 8, when a current I flows through the first heating coil 22, magnetic fluxes MF respectively surrounding portions of the first heating coil 22 are generated. The density of the magnetic flux MF is higher at the portion where the radius of curvature is small than at the portion where the radius of curvature is large.
Therefore, the magnetic flux density in the second ferrite 28 disposed in the corner portion 22c of the first heating coil 22 having a small radius of curvature is higher than the magnetic flux density in the first ferrite 26 disposed in the arc-shaped portion having a large radius of curvature. As a result, the second ferrite 28 is more likely to be in a high temperature state than the first ferrite 26.
In order to suppress the second ferrite 28 from being in a high temperature state, the second ferrite 28 has a larger magnetic path cross-sectional area than the first ferrite 26, and thus has a shape different from that of the first ferrite 26.
Specifically, for example, the magnetic flux generated from the first heating coil 22 and collected in the second ferrite 28 mainly enters from the tip end of one of the outer side wall portion 28b and the center side wall portion 28c of the second ferrite 28 to extend toward the main body portion 28a, and extends from the main body portion 28a toward the other to come out from the tip end of the other. Thereby, the magnetic field expands upward, that is, toward the cooking container C on the top plate 12. The magnetic flux also passes through the first ferrite 26.
The area of the cross section perpendicular to the path (magnetic path) of the magnetic flux (magnetic path cross section) is larger than that of the first ferrite 26. Thus, the magnetic flux density in the second ferrite 28 is lower than that in the first ferrite 26. As a result, the second ferrite 28 is brought into a temperature state similar to that of the first ferrite 26, and is suppressed from being brought into a high temperature state.
In the present embodiment, as shown in fig. 6 and 7, the outer wall 26b of the first ferrite 26 and the outer wall 28b of the second ferrite 28, which are disposed outside the first heating coil 22, respectively, have different thicknesses d1 and d2, and d2 is larger than d 1. Thus, the magnetic path cross-sectional area of the second ferrite 28 is larger than that of the first ferrite 26.
Similarly, in the second heating coil 24, the third ferrite 30 surrounds the arc-shaped portion 24b of the second heating coil 24 in a state of being opened upward. The fourth ferrite 32 surrounds the corner portions 24c of the second heating coil 24 located at both ends of the linear portion 24a, that is, located between the linear portion 24a and the arcuate portion 24b, in a state of being opened upward.
In the second heating coil 24, when the arc-shaped portion 24b is compared with the corner portion 24c, the radius of curvature of the latter is small. Therefore, the center side wall portion 32c of the fourth ferrite 32 is formed in a semi-cylindrical shape (a semicircular shape when viewed from above (viewed in the Z direction)) unlike the rectangular parallelepiped center side wall portion 30c of the third ferrite 30 so that the center side wall portion 32c of the fourth ferrite 32 does not come too close to the second heating coil 24.
The magnetic path cross-sectional area of the fourth ferrite 32 is made larger than that of the third ferrite 30 for the same reason and by the same method as the second ferrite 28.
In the case of the present embodiment, as shown in fig. 5, the intervals between adjacent coil lines in the corner portions 22c, 24c of the first heating coil 22 and the second heating coil 24 in which the second ferrite 28 and the fourth ferrite 32 are arranged are larger than those in the portions other than the corner portions. In the case of the present embodiment, the interval P between the third and fourth coil lines is larger than the interval between the other coil lines from the center side. By adjusting the intervals of the coil lines in this way, the first heating coil 22 and the second heating coil 24 can be expanded outward without reducing the radius of curvature of the coil line on the most center side of the corner portions 22c, 22c. As a result, the magnetic field generated by the first heating coil 22 and the second heating coil 24 can be expanded in the horizontal direction (X-axis direction). Further, if the first heating coil 22 and the second heating coil 24 are expanded outward without expanding the pitch interval, the radius of curvature of the corner portion becomes smaller, and there is no longer a space for disposing the center side wall portions 28c, 32c of the second ferrite 28 and the fourth ferrite 32.
As shown in fig. 5, the common ferrite 34 is shared by the first heating coil 22 and the second heating coil 24, unlike the first ferrite 26 to the fourth ferrite 32.
Fig. 9 is a perspective view of the common ferrite.
As shown in fig. 9, in the case of the present embodiment, the common ferrite 34 has a shape of a letter コ. Specifically, the common ferrite 34 has: a rectangular parallelepiped main body 34a extending in the horizontal direction (X-axis direction, Y-axis direction), and rectangular parallelepiped wall 34b erected in the vertical direction (Z-axis direction) from both ends of the main body 34 a.
As shown in fig. 5, the linear portion 22a of the first heating coil 22 and the linear portion 24a of the second heating coil 24 adjacent to each other are arranged between the two wall portions 34b above the main body portion 34a of the common ferrite 34. Specifically, a part of the coil base 20 is located between the main body 34a and the linear portions 22a and 24a of the first and second heating coils 22 and 24. In addition, one wall portion 34b is located in the coil opening of the first heating coil 22, and the other wall portion 34b is located in the coil opening of the second heating coil 24. In other words, the common ferrite 34 surrounds the linear portion 22a in the first heating coil 22 and the linear portion 24a in the second heating coil 24 adjacent to each other in a state where a part thereof is open (state where the top plate 12 side is open).
The reason for using such a common ferrite 34 will be described. The description will be made with reference to examples and comparative examples.
Fig. 10A shows the magnetic field distribution of the heating coil unit of the embodiment having the common ferrite. Fig. 10B shows the magnetic field distribution of the heating coil unit of the comparative example having no common ferrite.
Fig. 10A and 10B show magnetic field distributions when currents in the same direction flow through the straight portions 22a, 24a of the first heating coil 22 and the second heating coil 24, respectively. In the case of the comparative example shown in fig. 10B, instead of the common ferrite, a ferrite 150 surrounding the linear portion 22a of the first heating coil 22 in an open-top state and a ferrite 152 surrounding the linear portion 24a of the second heating coil 24 in an open-top state are used. The ferrite 150 has the same shape as the first ferrite 26, and the ferrite 152 has the same shape as the third ferrite 30.
As shown in fig. 10A, in the case of using the common ferrite 34, a magnetic flux MF1 is generated that passes through both the linear portions 22a, 24a inside the common ferrite 34 and surrounding the first heating coil 22 and the second heating coil 24. The magnetic flux MF1 is stronger than the magnetic flux MF2 passing through the first ferrite 26 and the magnetic flux MF3 passing through the third ferrite 30. That is, since the coil wire is surrounded by 2 times, the magnetic flux density in the common ferrite 34 is higher than the magnetic flux density in the first ferrite 26 and the third ferrite 30.
On the other hand, in the case of the comparative example shown in fig. 10B, a magnetic flux MF4 passing through the ferrite 150 and surrounding the linear portion 22a of the first heating coil 22 is generated. At the same time, a magnetic flux MF5 is generated that passes through the ferrite 152 and surrounds the linear portion 24a of the second heating coil 24.
Since the number of coil lines enclosed is the same, the magnetic flux MF4 generated by the ferrite 150 should be the same as the magnetic flux MF2 generated by the first ferrite 26, and the magnetic flux MF5 generated by the ferrite 152 should be the same as the magnetic flux MF3 generated by the third ferrite 30. However, the magnetic flux passing through the outer side wall portion 150b of the ferrite 150 and the magnetic flux passing through the outer side wall portion 152b of the ferrite 152 are opposite in direction to each other, and thus cancel each other.
In addition, as shown in fig. 10A, in the case of the heating coil unit having the embodiment of the common ferrite 34, the distance in the parallel direction (Y-axis direction) of the linear portion 22a of the first heating coil 22 and the linear portion 24a of the second heating coil 24 can be reduced as much as possible. Therefore, the mutual cancellation of the magnetic flux generated around the coil lines in the linear portion 22a of the first heating coil 22 and the magnetic flux generated around the coil lines in the linear portion 24a of the second heating coil 24 is suppressed.
On the other hand, in the case of the comparative example shown in fig. 10B, the outer side wall portion 150B of the ferrite 150 and the outer side wall portion 152B of the ferrite 152 exist between the first heating coil 22 and the second heating coil 24. Therefore, the linear portion 22a of the first heating coil 22 and the linear portion 24a of the second heating coil 24 cannot be made to approach each other to the same extent as in the embodiment.
Therefore, in the case of the comparative example, since ferrite exists between the first heating coil 22 and the second heating coil 24, a part of the magnetic flux generated from the first heating coil 22 and a part of the magnetic flux generated from the second heating coil 24 cancel each other out.
In contrast, in the case of the embodiment shown in fig. 10A, the mutual cancellation of the magnetic flux generated from the first heating coil 22 and the magnetic flux generated from the second heating coil 24 is suppressed by using the common ferrite 34. That is, the electric power supplied to the first heating coil 22 and the second heating coil 24 can be converted into the magnetic field with high conversion efficiency. Thus, a high heating force can be achieved by the first heating coil 22 and the second heating coil 24 without flowing a large current through the first heating coil 22 and the second heating coil 24 and without increasing the number of turns. As a result, the heating coil unit 16 can suppress heat generation and increase in size, and can inductively heat a cooking container made of a nonmagnetic material such as aluminum or copper.
As shown in fig. 5, the common ferrite 34 surrounds 2 times the number of coil lines as compared with the first ferrite 26 to the fourth ferrite 32. Therefore, the common ferrite 34 preferably has a larger magnetic path cross-sectional area than the first ferrite 26 to the fourth ferrite 32. This suppresses the common ferrite 34 from being in a high-temperature state and suppresses the generation of magnetic saturation in the common ferrite 34. In the case of the present embodiment, as shown in fig. 6, 7, and 9, the magnetic path cross-sectional area (cross-section perpendicular to the extending direction) of the main body portion 34a of the common ferrite 34 is larger than the main body portions 26a to 32a of the first ferrite 26 to the fourth ferrite 32.
As shown in fig. 5, the auxiliary ferrite 36 surrounds a part of the first heating coil 22 and the second heating coil 24 in a partially opened state, unlike the first ferrite 26 to the fourth ferrite 32 and the common ferrite 34.
Fig. 11 is a perspective view of the auxiliary ferrite.
As shown in fig. 11, in the case of the present embodiment, the auxiliary ferrite 36 has an "L" shape. Specifically, the auxiliary ferrite 36 has a rectangular parallelepiped main body 36a extending in the horizontal direction (X-axis direction, Y-axis direction) and a rectangular parallelepiped outer side wall 36b erected in the vertical direction (Z-axis direction) from one end of the main body 36 a.
As shown in fig. 5, the auxiliary ferrite 36 is provided to the first heating coil 22 and the second heating coil 24, respectively. In the case of the present embodiment, the auxiliary ferrite 36 is disposed between the first ferrite 26 and the second ferrite 28, and between the third ferrite 30 and the fourth ferrite 32. Further, the first heating coil 22 and the second heating coil 24 are disposed above the main body portion 36a of the auxiliary ferrite 36. Specifically, a part of the coil base 20 is located between the main body 36a and the first heating coil 22 and the second heating coil 24. The outer side wall 36b is located outside the first heating coil 22 and the second heating coil 24.
Such an auxiliary ferrite 36 can be provided at a portion of the first heating coil 22 and the second heating coil 24 where the first ferrite 26 to the fourth ferrite 32 cannot be disposed. The auxiliary ferrite 36 can further expand the magnetic field upward.
In addition, the auxiliary ferrite 36 may be disposed between the first ferrites 26 or between the third ferrites 30.
As shown in fig. 3, the shield plate 38 is made of a metal material such as aluminum, and the shield plate 38 has a bottom portion 38a and a cylindrical portion 38b erected from the outer peripheral edge of the bottom portion 38 a. The shield plate 38 is fitted to the outer peripheral surface 20c of the coil base 20. A plurality of through holes for cooling the first heating coil 22, the second heating coil 24, the first ferrite 26 to the fourth ferrite 32, the common ferrite 34, and the auxiliary ferrite 36 are provided in the bottom 38a of the shielding plate 38. However, a plurality of through holes are provided so that the bottom 38a of the shield plate 38 is located below the first ferrite 26 to the fourth ferrite 32, the common ferrite 34, and the auxiliary ferrite 36. This can suppress leakage of magnetic flux from each ferrite to the lower side of the shield plate 38.
According to the present embodiment described above, in the heating coil unit 16 of the induction heating cooker 10 having the first heating coil 22 and the second heating coil 24, heating power is realized in which heat generation and enlargement can be suppressed and induction heating can be performed also on a cooking container made of a nonmagnetic material. That is, the first heating coil 22 and the second heating coil 24 can achieve a high heating force without flowing a large current through the first heating coil 22 and the second heating coil 24 and without increasing the number of turns.
The present invention has been described above by referring to the above embodiments, but the present invention is not limited to the above embodiments.
For example, in the case of the above-described embodiment, as shown in fig. 6, 7 and 9, the first ferrite 26 to the fourth ferrite 32 and the common ferrite 34 have a shape of a so-called "コ", but the embodiment of the present invention is not limited thereto. For example, the shape may be a "C" shape or a "U" shape. That is, the first to fourth ferrites and the common ferrite may be shaped so as to surround the first heating coil and the second heating coil in a state of being opened upward.
In the case of the above embodiment, the first heating coil and the second heating coil have a so-called "D" shape, but the embodiment of the present invention is not limited thereto. For example, the shape may be an oblong shape or an elliptical shape.
In the case of the above embodiment, the portions of the first heating coil and the second heating coil that are surrounded by the common ferrite and are adjacent to each other are linear, but the embodiment of the present invention is not limited thereto. However, since a plurality of common ferrites can be used as shown in fig. 5, a linear shape is preferable.
That is, the heating coil unit according to the embodiment of the present invention broadly includes a first heating coil, a second heating coil, and a plurality of ferrites including a common ferrite, and the common ferrite surrounds adjacent portions of the first heating coil and the second heating coil adjacent to each other in a state of being open at the upper side.
Industrial applicability
The present invention can be applied to any heating coil unit of an induction heating cooker having a plurality of heating coils.
Claims (10)
1. A heating coil unit, comprising:
a first heating coil and a second heating coil; and
a plurality of the ferrite elements are arranged in a plurality of the ferrite elements,
the plurality of ferrites include a common ferrite which surrounds adjacent portions of the first heating coil and adjacent portions of the second heating coil adjacent to each other in a state where the common ferrite is opened upward,
the plurality of ferrites comprise: a first ferrite and a second ferrite surrounding a portion of the first heating coil different from the adjacent portion in a state where an upper side is opened; and third and fourth ferrites surrounding a portion of the second heating coil different from the adjacent portion in a state where an upper side is opened,
a portion of the common ferrite and a portion of the first ferrite and the second ferrite are located within a coil opening of the first heating coil,
a portion of the common ferrite and a portion of the third ferrite and the fourth ferrite are located within a coil opening of the second heating coil.
2. The heating coil unit according to claim 1, wherein,
the common ferrite is in the shape of a 'コ' word.
3. The heating coil unit according to claim 1 or 2, wherein,
the common ferrite has a larger magnetic path cross-sectional area perpendicular to the extending direction than the first to fourth ferrites.
4. The heating coil unit according to claim 3, wherein,
in the first heating coil, a radius of curvature of a portion surrounded by the second ferrite is smaller than a radius of curvature of a portion surrounded by the first ferrite,
the second ferrite has a larger magnetic path sectional area than the first ferrite,
in the second heating coil, a radius of curvature of a portion surrounded by the fourth ferrite is smaller than a radius of curvature of a portion surrounded by the third ferrite,
the fourth ferrite has a larger magnetic path sectional area than the third ferrite.
5. The heating coil unit according to claim 3, wherein,
the first ferrite to the fourth ferrite are in a shape of a コ character.
6. The heating coil unit according to claim 1, wherein,
the plurality of ferrites includes an auxiliary ferrite having an L-shape.
7. The heating coil unit according to claim 1, wherein,
adjacent portions of each of the first heating coil and the second heating coil are straight portions parallel to each other.
8. The heating coil unit according to claim 7, wherein,
the first heating coil and the second heating coil are in a D shape,
the common ferrite is not provided with a separation between the first heating coil and the second heating coil.
9. The heating coil unit according to claim 7 or 8, wherein,
the first heating coil and the second heating coil are each located at a corner portion of both ends of the linear portion at a larger interval than the coil lines in a portion other than the corner portion.
10. An induction heating cooker, comprising:
a top plate; and
a heating coil unit disposed below the top plate,
the heating coil unit has:
a first heating coil and a second heating coil; and
a plurality of the ferrite elements are arranged in a plurality of the ferrite elements,
the plurality of ferrites include a common ferrite which surrounds adjacent portions of the first heating coil and adjacent portions of the second heating coil adjacent to each other in a state where the common ferrite is opened upward,
the plurality of ferrites comprise: a first ferrite and a second ferrite surrounding a portion of the first heating coil different from the adjacent portion in a state where an upper side is opened; and third and fourth ferrites surrounding a portion of the second heating coil different from the adjacent portion in a state where an upper side is opened,
a portion of the common ferrite and a portion of the first ferrite and the second ferrite are located within a coil opening of the first heating coil,
a portion of the common ferrite and a portion of the third ferrite and the fourth ferrite are located within a coil opening of the second heating coil.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2018-106949 | 2018-06-04 | ||
| JP2018106949A JP7108852B2 (en) | 2018-06-04 | 2018-06-04 | Heating coil unit and induction heating cooker provided with the same |
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| Publication Number | Publication Date |
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| CN110557855A CN110557855A (en) | 2019-12-10 |
| CN110557855B true CN110557855B (en) | 2023-10-24 |
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| CN201910467289.0A Active CN110557855B (en) | 2018-06-04 | 2019-05-31 | Heating coil unit and induction heating cooker having the same |
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| Country | Link |
|---|---|
| EP (1) | EP3579661B1 (en) |
| JP (1) | JP7108852B2 (en) |
| CN (1) | CN110557855B (en) |
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| JP7372168B2 (en) | 2020-02-14 | 2023-10-31 | 象印マホービン株式会社 | heating cooker |
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| FR2657486A1 (en) * | 1990-01-24 | 1991-07-26 | Bonnet Sa | Appliance for cooking by electromagnetic induction |
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| JPS51112249U (en) * | 1975-03-10 | 1976-09-10 | ||
| JPH1066643A (en) * | 1996-08-28 | 1998-03-10 | Matsushita Electric Ind Co Ltd | Electric rice cooker |
| JPH11162627A (en) * | 1997-12-01 | 1999-06-18 | Matsushita Electric Ind Co Ltd | Induction cooking apparatus |
| JP2005228571A (en) | 2004-02-12 | 2005-08-25 | Totoku Electric Co Ltd | Electromagnetic induction heating coil and electromagnetic induction heating device |
| US8350194B2 (en) * | 2009-01-12 | 2013-01-08 | Samsung Electronics Co., Ltd. | Cooking apparatus and heating device including working coils thereof |
| JP5271810B2 (en) | 2009-05-29 | 2013-08-21 | 日立アプライアンス株式会社 | Electromagnetic induction heating device |
| JP5235836B2 (en) | 2009-10-20 | 2013-07-10 | 三菱電機株式会社 | Induction cooking device |
| WO2011148468A1 (en) | 2010-05-26 | 2011-12-01 | 三菱電機株式会社 | Transformer |
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- 2019-05-31 CN CN201910467289.0A patent/CN110557855B/en active Active
- 2019-05-31 EP EP19177673.1A patent/EP3579661B1/en active Active
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| JPH01246782A (en) * | 1988-03-29 | 1989-10-02 | Toshiba Corp | Electromagnetic cooking apparatus |
| FR2657486A1 (en) * | 1990-01-24 | 1991-07-26 | Bonnet Sa | Appliance for cooking by electromagnetic induction |
| JPH08256904A (en) * | 1995-03-27 | 1996-10-08 | Zojirushi Corp | Ferrite core for electromagnetic introduction heating cooking utensil and its mounting structure |
| JP2000005051A (en) * | 1998-06-26 | 2000-01-11 | Zojirushi Corp | Induction heating type rice cooker |
| JP2001078881A (en) * | 1999-09-10 | 2001-03-27 | Matsushita Electric Ind Co Ltd | Rice cooker |
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Also Published As
| Publication number | Publication date |
|---|---|
| JP7108852B2 (en) | 2022-07-29 |
| CN110557855A (en) | 2019-12-10 |
| EP3579661A1 (en) | 2019-12-11 |
| JP2019212462A (en) | 2019-12-12 |
| EP3579661B1 (en) | 2021-08-25 |
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