JP2023161832A - heating cooker - Google Patents

Abstract

To suppress deformation of a coil of a heating cooker having a plurality of coils.SOLUTION: A heating cooker comprises: a housing part 40 with a bottom that houses a pot; a non-cylindrical shape coil 55 that is arranged to a peripheral direction as a center of a shaft line of the housing part 40 on an outer surface side positioned at the side opposite to the pot in the housing part 40, and guides and heats the pot; and a coil depressing part 67 that is adjacent from an outer surface side to an end part of a peripheral direction of the coil 55. Deformation easily occurred in the end part of the peripheral direction of the outer side coil 55 is suppressed.SELECTED DRAWING: Figure 11

Description

The present invention relates to a heating cooker.

Patent Document 1 discloses a heating cooker in which a plurality of coils are arranged at intervals in the circumferential direction of a bottomed cylindrical housing part that accommodates a pot.

Japanese Patent Application Publication No. 2021-129843

By reducing the gap between coils adjacent to each other in the circumferential direction of the pot, a heating area by a plurality of coils may be secured. The applicant of the present application has obtained a new finding that in such a case, as the coil is used repeatedly, the end of the coil in the circumferential direction of the pot may become deformed in a direction away from the pot. This deformation can cause undercooking of the pan. Patent Document 1 does not disclose the insufficient heating of the pot due to the occurrence of warping.

An object of the present invention is to suppress deformation of the coils of a heating cooker including a plurality of coils.

One aspect of the present invention includes a bottomed cylindrical storage part that stores a pot, and a housing part that is arranged in a circumferential direction around an axis of the storage part on an outer surface side opposite to the pot in the storage part, The present invention provides a heating cooker including a non-circular coil for induction heating the pot, and a coil pressing portion adjacent to the circumferential end of the coil from the outer surface side.

According to this aspect, the coil pressing portion can suppress deformation that is likely to occur particularly at the ends in the circumferential direction of the coil due to heating by energization. For example, resin such as varnish applied to the coil in order to keep it curved along the shape of the housing section softens when heated, causing the circumferential end of the coil to move away from the curved shape of the housing section. When the coil is deformed, the end of the coil comes into contact with the holding part. Thereby, deformation of the coil can be suppressed by the coil pressing portion.

The coil may have a long axis in a circumferential direction of the pot and a short axis in a radial direction of the pot.

According to this configuration, the radius of curvature of the coil in the circumferential direction is smaller than the radius of curvature of the short axis of the coil in the radial direction. In other words, the curvature of the coil in the circumferential direction changes more rapidly than in the radial direction. As the coil is used repeatedly (heated and non-heated states are repeated), strain tends to occur at the ends of the coil in the circumferential direction where the curvature changes rapidly, so the effect of suppressing coil deformation by the holding part becomes more pronounced. It will be done.

The width of the coil in the circumferential direction of the pot may be larger than the width of the coil in the radial direction of the pot.

According to this configuration, when trying to make the width of the coil in the circumferential direction larger than the width of the coil in the radial direction, the thickness of the coil in the circumferential direction is made thinner than the thickness of the coil in the radial direction. Since the coil needs to be stretched in the same direction and the thinner the coil is, the coil is more likely to deform. Therefore, the effect of suppressing the deformation of the coil by the holding part is more noticeable.

The coil holding portion may include a first holding portion adjacent to an outer circumferential side of the coil, and a second holding portion adjacent to an inner circumferential side of the coil.

According to this configuration, by providing a gap between the first holding part and the second holding part, deformation of the coil can be suppressed without impeding heat dissipation of the coil.

a ferrite holder that holds a ferrite core disposed outside the coil;
The coil holding portion may be provided on the ferrite holder.

According to this configuration, since the coil holding part is provided in the ferrite holder, a dedicated part for providing the coil holding part is not required, and an increase in the number of parts can be suppressed.

A sensor that comes into contact with the pot is arranged in the housing part,
The coil may be provided close to the sensor.

According to this configuration, the temperature and the like of the coil can be detected with higher accuracy by the sensor than when the coil is provided apart from the sensor.

A gap between the coil and the sensor may be set to 3 mm or more and 20 mm or less.

According to this configuration, the gap between the coil and the sensor is appropriately set. If it is less than 3 mm, the ease of assembling the coil will be hindered, and if it exceeds 20 mm, the accuracy of temperature detection etc. by the sensor will decrease.

ADVANTAGE OF THE INVENTION According to this invention, the deformation|transformation of the coil of the heating cooker provided with the several coil can be suppressed.

FIG. 1 is a perspective view of a rice cooker (heating cooker) according to an embodiment of the present invention. A cross-sectional view of the rice cooker with the lid body hidden. An exploded perspective view of a rice cooker. FIG. 3 is a perspective view of a protective frame with a coil attached thereto. The figure which looked at the inner coil from the direction in which the axis line of the inner coil extends. A view of the outer coil viewed from the direction in which the axis of the outer coil extends. FIG. 3 is a diagram schematically showing a cross section along the long axis of the outer coil. 5 is a sectional view taken along line VIII-VIII in FIG. 4. FIG. The bottom view of the ferrite holder attached to the protection frame. FIG. 3 is a perspective view of the ferrite holder from below. FIG. 3 is a perspective view of the ferrite holder attached to the protection frame. The perspective view of the ferrite holder seen from the direction where an outer coil is the front. FIG. 3 is a perspective view of the ferrite holder seen from the direction in which the coil holding part faces the front.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view from above of a rice cooker (cooking device) 1 according to an embodiment of the present invention, with a lid 30 opened and a pot 10 taken out. FIG. 2 is a sectional view of the rice cooker 1. FIG. 3 is an exploded perspective view of the rice cooker 1.

As shown in FIG. 1, the rice cooker 1 includes a rice cooker main body 20 that removably accommodates a bottomed cylindrical pot 10 for heating cooked rice, and a rice cooker main body 20 that is rotatably arranged relative to the rice cooker main body 20. A lid body 30 is provided.

Referring to FIGS. 1 and 2, the pot 10 is made of a magnetic material and is heated by induction by a coil 50 disposed within the rice cooker body 20. The pot 10 has a bottom portion 10a, a side portion 10b, and a curved portion 10c. The bottom portion 10a has a circular shape extending substantially flat in the left-right direction. The side portion 10b has a substantially cylindrical shape extending vertically and outward. The curved portion 10c connects the bottom portion 10a and the side portion 10b. The curved portion 10c has a curved shape that connects the radially outer end of the bottom portion 10a and the lower end of the side portion 10b.

The lid 30 is rotatably attached to the connection part 24 of the rice cooker main body 20, and closes the opening 20a of the rice cooker main body 20 when it is closed with respect to the rice cooker main body 20.

Referring to FIG. 3, the lid body 30 has an operation section 31 for operating the rice cooker 1 on its front side, and a display section 32 for displaying the operation status and operation status, and on its rear side, It has a steam exhaust port 33 which is an outlet of the exhaust passage.

The operation unit 31 has a plurality of operation buttons 31a and a release button 31b. The operation buttons 31a are buttons for switching the operating state of the rice cooker 1, and are, for example, a button to start cooking rice, a button to cancel the operation, a power button, etc. The release button 31b is a button for opening the lid 30 that is kept closed by the lock mechanism.

Referring to FIG. 1, an inner lid (not shown) is attached to the inside of the lid 30 to close the upper end opening 10d of the pot 10 in a closed state. The inner lid has a sealing member (not shown) that closely contacts the inner circumference of the upper end opening 10d of the pot 10 and closes the upper end opening 10d. The inner lid is detachably attached to the lid body 30.

As shown in FIGS. 2 and 3, the rice cooker main body 20 includes a casing 21, a housing section (protective frame) 40, a coil 50, a ferrite 91 (see FIG. 9), a ferrite holder 60, a reflector 70, a power supply board 26, It has an IH board 27 and a cooling fan 28.

As shown in FIG. 1, the casing 21 includes a casing body 22, a shoulder body 23, and a connecting portion 24. The casing body 22 is box-shaped and includes a bottom surface 22a, a peripheral wall 22b surrounding the bottom surface 22a, and an opening 22c formed at the upper end of the peripheral wall 22b.

The shoulder body 23 is attached from above so as to cover the opening 22c of the casing body 22. An engagement hole 23a is provided on the front side of the shoulder body 23 to engage with a lock pawl 34 provided at the front part of the lid body 30. The connecting portion 24 is a hinge portion provided on the rear side of the shoulder body 23 and for rotatably mounting the lid body 30.

As shown in FIG. 2, the protection frame 40 is arranged below the shoulder body 23 within the casing body 22. A pot 10 is arranged within the protective frame 40. An inner trunk 25 is arranged above the protection frame 40 and below the shoulder body 23. The inner body 25 has a cylindrical shape with a slightly larger diameter than the pot 10, and is made of a metal material. When the pot 10 is housed in the protection frame (accommodating portion) 40, the axis A of the pot 10 and the axis B of the protection frame 40 coincide.

FIG. 4 is a perspective view of the protection frame 40 with the coil assembled therein. FIG. 4 is shown upside down relative to FIGS. 1-3. In FIG. 4, the shape of the coil 50 is shown schematically for clarity and simplicity. In reality, the coil 50 has a spiral shape formed by winding wire. The coil 50 has multiple layers of windings stacked in the radial direction. In other words, the coil 50 has a plurality of layers of windings stacked outward from the outer peripheral surface of the protective frame 40 .

The protection frame 40 includes a bottomed cylindrical pot accommodating section 41 that accommodates the pot 10 and a board support section 42 that supports the power supply board 26 . The protective frame 40 is made of a non-conductive material (for example, a synthetic resin material).

Referring to FIGS. 2 and 4 together, the pot accommodating portion 41 has a bottom portion 41a, a side portion 41b, and a curved portion 41c. The bottom portion 41a is arranged outside the bottom portion 10a of the pot 10 and has a circular shape extending substantially flat in the left-right direction. The side portion 41b is arranged on the outside of the side portion 10b of the pot 10, and has a substantially cylindrical shape extending vertically and outward. The curved portion 41c is arranged on the outside of the curved portion 10c of the pot 10, and has a curved shape that connects the bottom portion 41a and the side portion 41b.

A screw hole is provided in the bottom portion 41a and the curved portion 41c, and a cylindrical boss 41d extending in the vertical direction is provided. The side portion 41b is provided with a cylindrical penetration portion (sensor attachment portion) 41e through which a temperature sensor (not shown) is disposed. The sensor disposed on the mounting portion 41e passes through the pot accommodating portion 41 and is in contact with the pot 10.

A plurality of bracket parts 44 are provided on the upper peripheral edge of the protection frame 40. The bracket portion 44 is used for screwing to the shoulder body 23. A center support portion 45 is provided at the center of the bottom surface of the protection frame 40. The center support portion 45 has a substantially cylindrical shape, projects downward, and is inserted into the center portion 61 of the ferrite holder 60 to position the ferrite holder 60 (see FIG. 9).

Referring to FIG. 4, a coil 50 having a non-circular shape (more specifically, a donut shape) in a plan view is disposed on the outer circumferential surface of the pot accommodating portion 41. The coil 50 includes an inner coil 51 and an outer coil 55 having different shapes, and generates an eddy current when a high frequency current is applied thereto, thereby heating the pot 10 by induction.

A plurality of the inner coils 51 and the outer coils 55 are arranged around the axis A. In this embodiment, three inner coils 51 and three outer coils 55 are arranged. The inner coils 51 that are adjacent to each other in the circumferential direction are spaced from each other, and the outer coils 55 that are adjacent to each other in the circumferential direction are spaced from each other. The radially adjacent inner coil 51 and outer coil 55 are spaced apart from each other.

The inner coil 51 is arranged from the bottom 41a of the pot accommodating portion 41 to the outer surface of the curved portion 41c so as to heat the bottom 10a and the curved portion 10c of the pot 10 by induction. In other words, the inner coil 51 is arranged in a region extending from the bottom part 41a of the pot accommodating part 41 to the curved part 41c, on the radially inner side (on the axis A side) of the side part 41b.

FIG. 5 is a diagram of the inner coil 51 viewed from the direction in which the axis of the inner coil 51 extends.

Referring to FIGS. 4 and 5, the inner coil 51 has a non-circular shape having a long axis a1 extending in the radial direction of the pot 10 and a short axis a2 extending in the circumferential direction of the pot 10. In the inner coil 51 of this embodiment, the short axis a2 is located closer to the axis A than the center of the long axis a1.

As shown in FIG. 5, the inner coil 51 includes an inner portion 52 disposed on the axis A side of the pot 10, and an outer portion 53 extending radially outward from the inner portion 52 of the pot 10. The inner part 52 and the outer part 53 are connected via a pair of curved parts 54 curved at a predetermined curvature. The inner part 52, the outer part 53, and the curved part 54 are all formed in an arc shape with a predetermined curvature, but are not limited to a strict arc shape, and may be substantially arc shaped from one end to the other end. Good to have.

The inner portion 52 extends in the circumferential direction of the pot 10 as a whole. The inner portion 52 is curved with a predetermined radius of curvature R1. The outer portion 53 extends radially outward from the inner portion 52 of the pot 10 and is curved with a predetermined radius of curvature R2 smaller than the radius of curvature R1. The curved part 54 connects the inner part 52 and the outer part 53. The curved portion 54 is curved with a predetermined radius of curvature R3 that is larger than the radius of curvature R1.

FIG. 6 is a diagram of the outer coil 55 viewed from the direction in which the axis of the outer coil 55 extends.

Referring to FIGS. 4 and 6, the outer coil 55 is arranged radially outward than the inner coil 51 with respect to the axis A so as to inductively heat the bottom part 41a of the pot 10 other than the center part. The outer coil 55 is disposed extending from the side portion 41b of the pot accommodating portion 41 to the curved portion 41c. The outer coil 55 is curved along the radial and circumferential curved surfaces of the pot accommodating portion 41 as a whole.

As shown in FIG. 6, the outer coil 55 has a non-circular shape with a long axis a3 extending in the circumferential direction of the pot 10 and a short axis a4 extending in the radial direction of the pot 10. The outer coil 55 of this embodiment has a generally elliptical shape, and has a flat shape with a larger amount of radial collapse than the inner coil 51.

The ratio of the long axis a3 to the short axis a4 of the inner peripheral portion 55a of the outer coil 55 is set to 2.5 times or more and 3 times or less, preferably 2.7 times or more and 2.9 times or less. The ratio of the long axis a3 to the short axis a4 of the outer peripheral portion 55b of the outer coil 55 is set to 2 times or more and 2.5 times or less, preferably 2.2 times or more and 2.4 times or less.

The shape of the outer coil 55, like the inner coil 51, depends on the shape of the jig for forming the outer coil 55. The jig has a shape that follows the shape of the pot accommodating portion 41. The coil wires wound around the jig and bundled are hardened by being filled with an insulating layer such as varnish, and the desired shape is maintained.

The outer coil 55 includes an inner portion 56 disposed on the axis A side of the pot 10 and an outer portion 57 extending radially outward from the inner portion 56 of the pot 10. The inner portion 56 and the outer portion 57 are connected via a pair of curved portions 58 curved at a predetermined curvature. The inner part 56, the outer part 57, and the curved part 58 are all formed in an arc shape with a predetermined curvature, but are not limited to a strict arc shape, and may be substantially arc shaped from one end to the other end. Good to have.

The inner portion 56 and the outer portion 57 extend in the circumferential direction of the pot 10 as a whole. The inner part 56 and the outer part 57 are curved with a predetermined radius of curvature (first radius of curvature) R4. The curved portion 58 connects the inner portion 56 and the outer portion 57. The curved portion 58 is curved with a predetermined radius of curvature (second radius of curvature) R5 smaller than the radius of curvature R4. The radius of curvature R5 of the curved part 58 is set smaller than the radius of curvature R4 of the inner part 56 and the outer part 57.

The ratio of the radius of curvature R5 of the curved portion 58 to the radius of curvature R4 of the inner portion 56 and the outer portion 57 is set to 1.5% or more and 3% or less. More preferably, it is set to 2% or more and 2.5% or less. In other words, the curvature of the curved portion 58 changes more rapidly than that of the inner portion 56 and the outer portion 57.

If the ratio of the radius of curvature is made too small, the area extending in the radial direction of the outer coil 55 becomes small, and the non-heated area in the radial direction becomes excessively wide. If the ratio of the radius of curvature R5 is excessively increased, the area of the curved portion 58 extending in the circumferential direction becomes smaller. The distance between adjacent outer coils 55 increases, and the non-heated area becomes excessively wide. Therefore, in order to ensure the heating area of the pot 10 by the outer coil 55, the ratio of the radius of curvature R5 to the radius of curvature R4 is preferably set within the above range.

As shown in FIG. 6, the width W1 of the curved portion 58 from the inner circumferential portion 55a to the outer circumferential portion 55b of the outer coil 55 is wider than the width W2 of the inner portion 56 and the outer portion 57. Therefore, in the outer coil 55, the heating area in the circumferential direction is wider than the heating area in the radial direction.

In this way, when the heating area in the circumferential direction formed by the curved part 58 is made wider than the heating area in the radial direction formed by the inner part 56 and the outer part 57, the thickness of the curved part 58 becomes larger than the heating area in the radial direction formed by the inner part 56 and the outer part 57. It becomes thinner towards the outside.

FIG. 7 is a diagram schematically showing a cross section of the outer coil 55 along the long axis a3.

The circumferential width W1 of the curved portion 58 is wider than the radial width W2 of the inner portion 56 and outer portion 57, so if the number of turns of the coil is the same, , the thickness T1 of the outer peripheral portion 58a of the curved portion 58 is thinner than the thickness T2 of the inner peripheral portion 58b of the curved portion 58.

The thickness of the curved portion 58 decreases from the inner side to the outer side in the circumferential direction of the outer coil 55. In this way, by expanding the surface area of the curved portion 58 in the circumferential direction more than the surface area of the inner portion 56 and the outer portion 57, the gap between the adjacent outer coils 55 can be reduced.

FIG. 8 is a sectional view of the outer coil 55 along the long axis a3 in the protection frame 40 to which the coil 50 and ferrite holder 60 are assembled.

As shown in FIG. 8, a sensor mounting portion 41e is arranged on the circumferential direction in which the long axis a3 of the curved portion 58 extends. By configuring the outer coil 55 as described above, the outer peripheral portion 55b of the curved portion 58 can be easily brought closer to the attachment portion 41e. The gap S between the outer peripheral portion 55b of the curved portion 58 and the attachment portion 41e can be set within a range that provides good detection response by the temperature sensor.

It is preferable that the gap S between the curved portion 58 and the attachment portion 41e is set to be 20 mm or less, and as short as possible. If the gap S is made too small, the ease of assembling the coil to the protective frame 40 may be hindered due to manufacturing errors in the coil.

As shown in FIGS. 4 and 8, the outer coil 55 is formed in a curved shape along the circumferentially extending curved surface of the side portion 41b and the curved portion 41c of the pot accommodating portion 41.

In the case of the above-mentioned outer coil 55, by repeating the heating state and the non-heating state, the curved portion 58 of the outer coil 55 is deformed in the direction away from the pot accommodating portion 41. This may cause insufficient heating in the portions where the coils are spaced apart.

That is, the applicant of the present invention has proposed that the radius of curvature R5 of the curved portion 58 at both ends in the circumferential direction is smaller than the radius of curvature R4 of the inner portion 56 and outer portion 57 at both ends in the radial direction, and the thickness of the curved portion 58 is We have found a new problem in that when an outer coil 55 that becomes thinner from the inside to the outside in the radial direction of the coil is used, deformation occurs at the circumferential end (curved portion 58) of the coil.

During cooking (heating), the temperature of the coil may rise to near the melting temperature of the insulating layer (for example, 120°C) due to the heat generated by the coil itself or radiant heat from the heated pot, and the temperature may rise between the non-heating state and the non-heating state. A temperature difference occurs. A new finding was obtained that this temperature difference tends to cause strain in the curved portion 58 where the curvature of the coil changes rapidly. Further, since the thickness of the curved portion 58 becomes thinner from the inner circumferential portion to the outer circumferential portion, the number of strands is small, and the insulating layer is easily melted. That is, the curved portion is more likely to be deformed.

On the other hand, in the present embodiment, a coil holding part is arranged in the ferrite holder 60 close to the outside of the circumferentially outer end (top) 58a of the curved part 58 (on the opposite side of the pot accommodating part 41). 67 suppresses deformation of the curved portion 58. As shown in FIG. 2, the ferrite holder 60 is disposed directly below the coil 50 and accommodates a ferrite core 91 (see FIG. 9) for converging the magnetic flux from the coil 50.

FIG. 9 is a bottom view of the ferrite holder 60 attached to the protection frame 40. FIG. 10 is a perspective view of the ferrite holder 60 from below. FIG. 11 is a perspective view of the ferrite holder 60 attached to the protection frame 40.

The ferrite holder 60 includes a central portion 61, first to third holding portions 62 to 64 that hold the ferrite core 91, and a coil holding portion 67. It is effective to arrange a plurality of ferrite cores for each coil 50 in order to concentrate the magnetic flux caused by energizing the coil 50 and to suppress magnetic flux leakage to the outside of the casing 21. Therefore, the first to third holding parts 62 to 64 are provided to correspond to each coil 50. The first to third holding parts 62 to 64 each have a slot shape, and a ferrite core is accommodated in the slot. The ferrite holder 60 further includes a boss receiving portion 60a for fixing to the protection frame 40, and a screwing portion 60b for screwing the reflecting plate 70 shown in FIG. 12.

The central portion 61 is an annular portion centered on the axis B. The center support portion 45 of the protection frame 40 is disposed to penetrate the inner space of the center portion 61 .

As shown in FIGS. 9 and 10, the first holding portion 62 protrudes radially from the central portion 61. As shown in FIGS. Three first holding parts 62 are provided at equal intervals in the circumferential direction around the central part 61. The first holding part 62 includes a radial part 62a that extends radially along the bottom 41a of the protection frame 40, and a radial part 62a that further extends in the radial direction from the outer end of the radial part 62a. B).

The first holding portion 62 includes a pair of side wall portions 62c, a connecting portion 62d, an elastic piece 62e, and a retaining portion 62f. The pair of side wall portions 62c extend from the radial portion 62a to the extension portion 62b. The connecting portion 62d connects the ends of the side wall portion 62c on the protection frame 40 side. The retaining portion 62f projects inward from the end of the side wall portion 62c opposite to the connecting portion 62d. The elastic piece 62e is formed by a part of the connecting portion 62d, and urges the ferrite core toward the retaining portion 62f. The connecting portion 62d, the elastic piece 62e, and the retaining portion 62f are provided in the radial portion 62a and the extending portion 62b, respectively.

The second holding portion 63 has a first circumferential portion 63a and a second circumferential portion 63b extending generally along the circumferential direction from both radially outer ends of the side wall portion 62c in the radial portion 62a. The first and second circumferential portions 63a and 63b include an outer peripheral wall 63c, a bottom wall 63d, a retaining portion 63f, and an elastic piece 63e. The outer peripheral wall 63c surrounds the outer peripheral part of the ferrite core. The bottom wall 63d partially closes the end of the outer peripheral wall 63c on the protection frame 40 side. The retaining portion 63f projects inward from the outer peripheral wall 63c from the end opposite to the bottom wall 63d. The elastic piece 63e extends in the radial direction from the bottom wall 63d and biases the ferrite core toward the retaining portion 63f.

The third holding portion 64 is connected between adjacent second holding portions 63 via a connecting portion 65 . The third holding portion 64 extends radially in the radial direction. Three third holding parts 64 are provided at equal intervals in the circumferential direction around the axis B. The third holding part 64 is arranged with a circumferential position offset from that of the first holding part 62. The third holding portion 64 includes a radial portion 64a that extends radially along the curved portion 41c of the protection frame 40, and a side portion 41b ( and an extending portion 64b extending along the axis B).

The third holding portion 64 includes a pair of side wall portions 64c, a connecting portion 64d, an elastic piece 64e, and a retaining portion 64f. The pair of side wall portions 64c extend from the radial portion 64a to the extension portion 64b. The connecting portion 64d connects the ends of the side wall portion 64c on the protection frame 40 side. The retaining portion 64f projects inward from the side wall portion 62c from the end of the side wall portion 64c on the opposite side to the connecting portion 64d. The elastic piece 64e is formed by a part of the connecting portion 64d, and urges the ferrite core toward the retaining portion 64f.

Referring to FIGS. 9 and 11, the first holding portion 62 is arranged along the long axis of the inner coil 51. As shown in FIG. The radial portion 62 a is located from outside the top of the inner portion 52 to within the inner diameter portion of the inner coil 51 . The radial portion 62 a is arranged to correspond to the inner portion 52 of the inner coil 51 . The extending portion 62b is located from outside the top of the outer portion 53 to within the inner diameter portion of the inner coil 51. The extending portion 62b is arranged to correspond to the outer portion 53 of the inner coil 51.

The second holding portion 63 is arranged along the short axis portion of the inner coil 51 . The first and second circumferential parts 63a and 63b are arranged at positions corresponding to from the curved part 54 of the inner coil 51 to the inner part 56 of the outer coil 55 between the two circumferentially adjacent radial parts 62a. has been done.

The third holding portion 64 is arranged along the long axis portion of the outer coil 55 between the first circumferential portion 63a and the second circumferential portion 63b adjacent to each other in the circumferential direction. The radial portion 64 a is located from outside the top of the inner portion 56 to within the inner diameter portion of the outer coil 55 . The radial portion 64a is arranged to correspond to the inner portion 56 of the outer coil 55. The extending portion 64b is located from outside the top of the outer portion 57 to within the inner diameter portion of the outer coil 55. The extending portion 64b is arranged to correspond to the outer portion 53 of the outer coil 55.

FIG. 12 is a perspective view of the ferrite holder 60 viewed from the direction in which the outer coil 55 faces the front. FIG. 13 is a perspective view of the ferrite holder 60 viewed from the direction in which the coil holding portion 67 faces the front.

As shown in FIG. 12, the coil pressing portion 67 is provided at a position corresponding to the pair of curved portions 58 of the outer coil 55. The coil pressing portion 67 is connected to the radially outer side of the outer peripheral wall 63c of the second holding portion 63. The coil pressing portion 67 extends radially in the radial direction. As shown in FIG. 10, the coil pressing portion 67 extends along the curved portion 41c and the side portion 41b (axis line B) of the protection frame 40.

Referring to FIG. 9, six coil pressing portions 67 are provided at equal intervals in the circumferential direction with the axis B as the center. The coil pressing portion 67 is arranged with a circumferential position offset from the first holding portion 62 and the third holding portion 64. Between adjacent coil holding parts 67, first holding parts 62 (extending parts 62b) and third holding parts 64 are arranged alternately.

As shown in FIG. 13, the coil holding part 67 includes a first holding part 67a, a second holding part 67b, a first connecting part 67c, a second connecting part 67d, a first opening 67e, and a second holding part 67a. and an opening 67f. The first pressing portion 67a and the second pressing portion 67b are separated by a predetermined width W3 corresponding to the circumferential width W2 of the curved portion 58 of the outer coil 55.

The first holding part 67a and the second holding part 67b are plate-shaped side walls that extend in the radial direction and protrude to the outside of the pot accommodating part 41. The thickness T3 (circumferential dimension) of the first holding portion 67a and the second holding portion 67b is set to be 1.5 mm or more and 3.5 mm or less. If it is less than 1.5 mm, the rigidity of the coil pressing portion 67 against deformation of the outer coil 55 is insufficient, and deformation of the coil is difficult to be suppressed. If it exceeds 3.5 mm, the area covered by the first holding part 67a and the second holding part 67b increases with respect to the outer coil 55, which may result in a decrease in heat dissipation.

As shown in FIG. 12, the first pressing portion 67a and the second pressing portion 67b have a predetermined cross-sectional height (dimension along the axis B). The cross-sectional height H1 of the tip portions of the first holding portion 67a and the second holding portion 67b is set to 20 mm or more and 30 mm or less. When it is less than 20 mm, the rigidity of the coil pressing portion 67 against deformation of the coil is insufficient, and deformation of the coil is difficult to be suppressed. If it exceeds 30 mm, it will be difficult to arrange it in the limited space between the casing 21 and the protection frame 40.

Referring to FIGS. 8 and 13, the first pressing portion 67a is arranged to abut near the circumferentially outer end (top) 58a of the curved portion 58 of the outer coil 55. The second pressing portion 67b is arranged so as to come into contact with the vicinity of the inner peripheral portion 58b of the curved portion 58 of the outer coil 55. The second connecting portion 67d is arranged between the outer circumferential portion and the inner circumferential portion of the curved portion 58 of the outer coil 55 so as to abut at a radial position corresponding to the long axis a3 of the outer coil 55. As a result, the first pressing portion 67a and the second connecting portion 67d press the outer peripheral portion and the vicinity of the inner peripheral portion of the curved portion 58 of the outer coil 55, and the second connecting portion 67d presses the top of the curved portion 58 of the outer coil 55. The area between 58a and inner peripheral portion 58b is suppressed by a surface.

The vicinity of the outer periphery means a width of 4 to 10 mm in the circumferential direction centering on the top 58a of the curved portion 58. The vicinity of the inner circumferential portion is defined as a width of 3 to 10 mm in the circumferential direction centered on the top of the curved portion 58 on the inner circumferential side. The radial position corresponding to the long axis a3 where the second connecting portion 67d is arranged includes a distance within 20 mm from the long axis a3 in the direction of the short axis a4.

The term "abutting" includes a case where the outer coil and the coil pressing portion 67 are separated from each other to such an extent that the outer coil 55 can be considered not to have been substantially deformed. For example, the separation distance between the curved portion 58 and the coil pressing portion 67 may be such that deformation is allowed to such an extent that insufficient heating will not occur due to the separation of the curved portion 58 from the protection frame 40 . In this embodiment, the coil pressing portion 67 and the outer coil 55 are set to interfere with each other by 0.3 mm. Thereby, even if the thickness of the coil or the dimensions of the coil holding portion vary due to manufacturing errors, deformation can be reliably suppressed.

As shown in FIG. 12, the first connecting portion 67c is provided on the base end side of the first and second holding portions 67a, 67b and on the radially inner side of the first and second holding portions 67a, 67b. There is. The first connecting portion 67c extends along the circumferential direction of the protection frame 40 and connects the first and second pressing portions 67a and 67b.

The second connecting portion 67d is provided at the radially outer tip portions of the first and second pressing portions 67a and 67b. The second connecting portion 67d extends in the circumferential direction of the protection frame 40 and connects the tips of the first and second pressing portions 67a and 67b. A dimension H2 in the radial direction (axis B direction) of the second connecting portion 67d is set so as to generally cover the curved portion 58 of the outer coil 55.

The first opening 67e is defined by a pair of opposing surfaces of the first holding part 67a and the second holding part 67b, the first connecting part 67c, and the outer peripheral wall 63c of the second holding part 63. The second opening 67f is defined by a pair of opposing surfaces of the first holding part 67a and the second holding part 67b, the first connecting part 67c, and the second connecting part 67d.

As shown in FIG. 2, a reflection plate 70 is arranged directly below the ferrite holder 60 to suppress the high frequency magnetic field generated from the coil 50 from having an adverse effect on peripheral devices. The reflecting plate 70 has an integral structure formed by bending a single sheet metal. The material of the reflector 70 is copper, aluminum, or the like, which has a lower electrical resistance value than the pot 10.

When the rice cooker main body 20 is assembled, the position of the coil 50 is fixed by being held between the ferrite holder 60 and the pot accommodating portion 41. In this embodiment, when the boss 41d of the pot accommodating part 41 is received in the boss receiver 60a of the ferrite holder 60, the boss 41d, the screw hole of the reflection plate 70, and the screw stopper part 60b of the ferrite holder 60 are aligned. Tighten and secure each.

The rice cooker 1 configured in this manner has the following features.

The coil pressing portion 67 can suppress deformation that is likely to occur particularly at the circumferential end portion of the outer coil 55 due to heating by energization. For example, a resin such as varnish applied to the outer coil 55 to keep it curved along the shape of the pot accommodating part 41 is softened by heating, and the end of the outer coil 55 in the circumferential direction (curved part 58) When the outer coil 55 is deformed in a direction away from the curved shape of the pot accommodating portion 41, the end portion of the outer coil 55 comes into contact with the coil pressing portion 67. Thereby, deformation of the outer coil 55 can be suppressed by the coil pressing portion 67.

Since the outer coil 55 has a long axis a3 in the circumferential direction of the pot 10 and a short axis a4 in the radial direction of the pot 10, the radius of curvature R5 in the circumferential direction of the outer coil 55 is It is smaller than the radius of curvature R4 of the short axis a4 in the radial direction. In other words, the curvature of the outer coil 55 in the circumferential direction changes more rapidly than in the radial direction. As the outer coil 55 is repeatedly used (repeated heating and non-heating states), strain tends to occur at the circumferential end (curved portion 58) of the outer coil 55 where the curvature changes rapidly. The effect of suppressing deformation of No. 55 can be more clearly obtained.

The thickness T1 of the circumferentially outer end (top) 58a of the curved portion 58, where the width W1 of the outer coil 55 is longer, is thinner than the thickness T2 of the circumferentially inner end 58b of the curved portion 58. Since it is easily deformed, the effect of suppressing the deformation of the coil by the coil pressing portion 67 can be more significantly obtained.

By providing a gap between the first holding part 67a and the second holding part 67b, which constitute a part of the coil holding part 67, deformation of the outer coil 55 is suppressed without impeding the heat dissipation of the outer coil 55. can.

Since the coil holding part 67 is provided in the ferrite holder 60, a dedicated part for providing the coil holding part 67 is not required, and an increase in the number of parts can be suppressed.

Since the outer coil 55 is provided close to the sensor (attachment part) 41e, compared to the case where the outer coil 55 is provided apart from the sensor (attachment part) 41e, the outer coil 55 is The temperature of the coil 55, etc. can be detected with high accuracy.

As shown in FIG. 7, the gap S between the outer coil 55 and the sensor (attachment part) 41e is set to 3 mm or more and 20 mm or less, so the gap S between the outer coil 55 and the sensor (attachment part) 41e is set appropriately. is set to If it is less than 3 mm, the ease of assembling the outer coil will be hindered, and if it exceeds 20 mm, the accuracy of temperature detection etc. by the sensor (attachment part) 41e will decrease.

In the above-described embodiment, the coil holding part 67 has the first holding part 67a, the second holding part 67b, and the second connecting part 67d. However, the structure is not limited to this, and the first holding part 67a Alternatively, it may be composed of only one of the second pressing portions 67b.

In the above-described embodiment, the coil holding part 67 has the first opening 67e and the second opening 67f, but the coil holding part 67 has the first opening 67e and the second opening 67f. 67e and 67f may not be provided.

In the above-described embodiment, a configuration has been described in which the coil pressing portion 67 is provided in the ferrite holder 60, but the coil pressing portion 67 is not limited to this, and may be provided in a separate member.

In the above-described embodiment, a configuration in which the radius of curvature of the inner part 56 and the outer part 57 of the outer coil 55 are the same has been described, but the present invention is not limited to this. For example, the radius of curvature of the inner part 56 is the same as that of the outer part 57. The inner part 56 and the outer part 57 may have different radii of curvature, such as an egg shape having a radius of curvature smaller than the radius of curvature of the inner part 56 and the outer part 57.

In the above-described embodiment, the configuration in which the pair of curved portions 58 of the outer coil 55 have the same radius of curvature has been described, but the invention is not limited to this, and the pair of curved portions 58 of the outer coil 55 have different radii of curvature. It may be composed of.

Note that the cooking device 1 of the present invention is not limited to the configuration of the above-described embodiment, and various changes can be made.

1 Heating cooker 10 Pot 24 Storage part 55 Outer coil (coil)
60 Ferrite holder 67 Coil holding part 67a First holding part 67b Second holding part a3 Long axis a4 Short axis A Axis line B Axis line W1 Width W2 Width

Claims (7)

a bottomed cylindrical housing part for housing the pot;
a non-circular coil that is arranged circumferentially around the axis of the housing part on an outer surface side opposite to the pot in the housing part and heats the pan by induction;
A heating cooker comprising: a coil presser portion adjacent to the outer surface side of the coil at a circumferential end portion of the coil. The cooking device according to claim 1, wherein the coil has a long axis in a circumferential direction of the pot and a short axis in a radial direction of the pot. The cooking device according to claim 1, wherein the width of the coil in the circumferential direction of the pot is larger than the width of the coil in the radial direction of the pot. The coil holding portion includes a first holding portion adjacent to the outer circumferential side of the coil, and a second holding portion adjacent to the inner circumferential side of the coil. heating cooker. a ferrite holder that holds a ferrite core disposed outside the coil;
The cooking device according to any one of claims 1 to 3, wherein the coil pressing portion is provided on the ferrite holder. A sensor that comes into contact with the pot is arranged in the housing part,
The heating cooker according to claim 1, wherein the coil is provided close to the sensor. The cooking device according to claim 6, wherein a gap between the coil and the sensor is set to 3 mm or more and 20 mm or less.

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