JP6708883B2 - Cooker using electromagnetic induction heating method - Google Patents

Description

The present invention relates to a cooker that uses an electromagnetic induction heating system.

BACKGROUND ART Heretofore, a cooker utilizing an electromagnetic induction heating method has been proposed as in Patent Document 1.

JP, 2003-102616, A

In such a cooker, a magnetic heating element is attached by caulking or the like to the bottom of the non-magnetic pan body, but caulking alone may loosen the joined state of the two and make it difficult for heat to be transferred from the heating element. is there.

Therefore, an object of the present invention is to provide a cooker in which heat from a heating element is easily transferred.

A cooker using an electromagnetic induction heating method according to the present invention includes a pot body and a heating element having a hardness higher than at least the bottom portion of the pot body and attached to the bottom portion, and the side of the heating element that contacts the bottom portion. A ring protruding toward the bottom is integrally formed on the first surface of the, and a groove portion having a groove width smaller than the thickness of the ring is provided in a region of the bottom portion facing the ring, and the ring is formed in the groove portion. The heating element is fixed to the bottom portion by pushing the second surface of the heating element opposite to the first surface so as to bite and caulking.

By pressing the second surface (upper surface) of the heating element and fitting the ring-shaped projection of the heating element into the groove provided on the bottom of the pan body, the primary fixing to the bottom of the heating element (first fixing) ) Is performed, and the caulking is performed to perform secondary fixation (second fixation) to the bottom of the heating element.

For this reason, it is easier to maintain the fixed state between the bottom portion and the heating element, as compared with the form in which the heating element is fixed to the bottom portion only by caulking without providing the ring-shaped protrusion.
Since the ring-shaped protrusion is fitted into the groove portion provided in the bottom portion, the protrusion does not buckle and can easily enter, as compared with a configuration in which the groove portion is not provided.

In addition, since the contact area between the bottom and the heating element can be increased by the amount of the ring-shaped protrusion, the efficiency of heat transfer from the heating element to the pan body can be increased.

Preferably, the heat generating element is provided with a recess having a second surface recessed, a first surface protruding, and a U-shaped cross section as a ring, and a recessed portion provided as a groove in a region of the bottom portion facing the recessed portion. A groove portion for recess having a groove width smaller than the thickness of the region facing the bottom portion is provided.

Since the groove portion (recess groove portion) is configured such that the groove width of the groove portion is smaller than the thickness of the protrusion (recess portion) fitted into the groove portion, the bottom region of the recess portion is bent in the direction away from the bottom portion. In this state, the heating element is fitted into the bottom.
The amount of bending of the bent portion (bottom region) varies due to heat, and the variation of the amount of bending can prevent the generation of abnormal noise due to the difference in thermal expansion coefficient between the pot main body and the heating element.

More preferably, the groove width of the groove portion for recess is 4% smaller than the radial dimension of the region of the recess facing the bottom.

Further, preferably, the heating element is provided with a rib as a ring, and a groove portion for a rib having a groove width smaller than a radial thickness of the rib is provided in a region of the bottom portion facing the rib as a groove portion. .

More preferably, the groove width of the rib groove portion is 20% smaller than the radial thickness of the rib.

Further, preferably, the heating element has a hollow disc shape and has two or more rings, and the circular shape of the inner peripheral edge of the hollow disc shape and the two or more rings are arranged concentrically. It

The method of manufacturing a cooker using the electromagnetic induction heating method according to the present invention is a method of inserting a heating element having a hollow plate shape between the protrusions used for caulking provided at the bottom of the pan body. A body inserting step and a ring integrally formed on the first surface of the heating element on the side in contact with the bottom, and protruding toward the bottom, so as to bite into a groove provided in the bottom and having a groove width smaller than the ring, It comprises a pushing step of pushing a second surface of the heating element opposite to the first surface, and a crimping step of deforming the protruding portion so as to cover the outer peripheral edge portion and the inner peripheral edge portion of the hollowed-out plate shape and performing the crimping. .

As described above, according to the present invention, it is possible to provide a cooker in which heat from the heating element is easily transmitted.

It is a perspective view which shows the state before a heating element is attached to the pan main body in the cooking device in this embodiment. FIG. 6 is a perspective view showing the positional relationship between the bottom of the pan body and the lower surface of the heating element that faces the bottom. It is a perspective view showing a pan body and a heating element after a heating element inserting step. It is a perspective view which shows the pan main body and the heat generating body after a pushing process. It is a perspective view showing a pan body, a heating element, a first caulking jig and a second caulking jig after the fitting step. It is a perspective view showing a pan body, a heating element, a first caulking jig, and a second caulking jig after the caulking step. It is a perspective view which shows the pan main body and the heat generating body after a removal process. FIG. 4 is a cross-sectional configuration diagram of the pan body, the heating element, the first caulking jig, and the second caulking jig before the heating element is attached to the pan body. It is a cross-sectional block diagram of a pan main body and a heat generating body in the state before a heat generating body is attached to a pan main body. It is a cross-sectional block diagram which shows the pan main body and a heating element after a heating element insertion process. It is a cross-section block diagram which shows the pan main body and the heat generating body after a pushing process. It is a cross-section block diagram which shows the pan main body after a fitting process, a heat generating body, a 1st crimping jig, and a 2nd crimping jig. It is a cross-sectional block diagram which shows the pan main body after a crimping process, a heating element, a 1st crimping jig, and a 2nd crimping jig. It is a cross-section block diagram which shows the pan main body and the heat generating body after a removal process. It is a cross-sectional block diagram which shows the pan main body and a heat generating body when a heat generating body expands. It is a cross-sectional block diagram which shows the pan main body and a heat generating body when a heat generating body contracts.

Hereinafter, the present embodiment will be described with reference to the drawings. The cooker 1 using the electromagnetic induction heating method according to the present embodiment includes a pan body (a container for containing an object to be cooked) 10 and a heating element 20 (see FIGS. 1 to 16 ).
Further, when the heating element 20 is attached to the pan body 10, the first caulking jig 51 and the second caulking jig 52 are used. In this embodiment, the configuration of the cooking device 1 is described using a pot, but another cooking device 1 such as a frying pan may be used.

In addition, in order to make it easy to distinguish from other members, in FIGS. 1 to 7, the upper surface 20a of the heating element 20 (the first surface (the lower surface 20b, the first surface) on the side in contact with the bottom portion 11 and the opposite side) The second area) and the projected area on the lower surface 20b are meshed in a lattice pattern, but the meshing is not essential for carrying out the present invention.

The pot body 10 is made of a non-magnetic material such as an aluminum alloy, and the bottom 11 has first to third protrusions 11a to 11c used for attaching the heating element 20 and a groove 12 (first flange groove). 12a1, a second flange groove 12a2, a first recess groove 12b1, a second recess groove 12b2, a first rib groove 12c1 to a fourth rib groove 12c4) are provided.

The first protrusion 11a has a substantially hollow columnar shape (for example, a hollow columnar shape).
A first slope 11a1 is provided at the tip of the first protrusion 11a so that the outside is higher than the inside.

The second protrusion 11b has a substantially hollow columnar shape (for example, a hollow columnar shape) that surrounds the side surface of the first protrusion 11a.
A second slope 11b1 is provided at the tip of the second protrusion 11b so that the inside is higher than the outside.

The third protrusion 11c has a substantially hollow columnar shape (for example, a hollow columnar shape) that surrounds the side surface of the second protrusion 11b.

The first space 101 surrounded by the first protrusion 11a and the bottom portion 11 is a lower portion (bottom portion) of the first caulking jig 51 so that the first caulking jig 51 can be fitted inside the first protrusion portion 11a. 11 has a shape (substantially columnar in the present embodiment) substantially the same as that of the portion 11 in contact with.

The second space 102 surrounded by the first protrusions 11a, the second protrusions 11b, and the bottom 11 generates heat so that the heating element 20 can be inserted between the first protrusions 11a and the second protrusions 11b. It has substantially the same shape as the lower surface 20b of the body 20 (the surface on the side that contacts the bottom portion 11) (in this embodiment, a substantially donut shape).

A ring shape in which the inner flange 21a provided on the inner peripheral edge of the heating element 20 is fitted between the first protruding portion 11a and the second protruding portion 11b in the bottom portion 11 and near the first protruding portion 11a. The first flange groove portion 12a1 is provided.

A ring shape in which the outer flange 21b provided on the outer peripheral edge of the heating element 20 is fitted between the first protruding portion 11a and the second protruding portion 11b in the bottom portion 11 and in the vicinity of the second protruding portion 11b. The second flange groove 12a2 is provided.

Between the first flange groove portion 12a1 and the second flange groove portion 12a2 in the bottom portion 11, on the side closer to the first flange groove portion 12a1, the first recess portion h1 of the heating element 20 is fitted. The groove 12b1 is provided, and the second recess groove 12b2 into which the second recess h2 of the heating element fits is provided on the side closer to the second flange groove 12a2.

A first rib groove portion 12c1 into which the first rib a1 of the heating element 20 is fitted is provided between the first flange groove portion 12a1 and the first recess groove portion 12b1 in the bottom portion 11.
For the second rib in which the second rib a2 of the heating element 20 is fitted, on the side between the first recessed groove portion 12b1 and the second recessed groove portion 12b2 in the bottom portion 11 and close to the first recessed groove portion 12b1. The groove 12c2 is provided, and the third rib groove 12c3 into which the third rib a3 of the heating element 20 is fitted is provided on the side closer to the second recess groove 12b2.
A fourth rib groove portion 12c4 into which the fourth rib a4 of the heating element 20 is fitted is provided between the second recess groove portion 12b2 and the second flange groove portion 12a2 in the bottom portion 11.

A third space surrounded by the second protrusion 11b, the third protrusion 11c, and the bottom 11 so that the second caulking jig 52 can be fitted between the second protrusion 11b and the third protrusion 11c. 103 has substantially the same shape as the lower portion of the second caulking jig 52 (the portion on the side in contact with the bottom portion 11) (in this embodiment, a substantially donut shape).

The heating element 20 including the inner flange 21a, the outer flange 21b, the first rib a1 to the fourth rib a4, the first recess h1 and the second recess h2 is made of ferritic stainless steel having a hardness higher than that of the bottom 11 of the pan body 10. It is integrally formed of a magnetic material and has a hollow plate shape of 2.0 mm to 2.5 mm (for example, a hollow disk shape).

An inner flange 21a that extends toward the bottom 11 and projects radially inward is integrally formed on the inner peripheral edge of the surface of the heating element 20 on the side that contacts the bottom 11 (lower surface 20b). An outer flange 21b that extends toward the bottom portion 11 and protrudes outward in the radial direction is integrally formed in the portion, and the upper surface 20a is recessed and the lower surface 20b protrudes between the inner flange 21a and the outer flange 21b. A first concave portion h1 and a second concave portion h2 each having a V shape are formed, and a plurality of ring-shaped ribs (first rib a1 to fourth rib a4) that project toward the bottom portion 11 and surround the side surface of the inner flange 21a are integrally formed. Is formed.

The first rib a1 is provided between the inner flange 21a and the first recess h1.
The second rib a2 is provided between the first recess h1 and the second recess h2 and on the side closer to the first recess h1.
The third rib a3 is provided between the first recess h1 and the second recess h2 and on the side closer to the second recess h2.
The fourth rib a4 is provided between the second recess h2 and the outer flange 21b.

The first rib a1 surrounds the side surface of the inner flange 21a, and the outer peripheral wall of the portion forming the inner flange 21a and extending toward the bottom portion 11 is in a positional relationship facing the inner peripheral wall of the first rib a1.
The first recess h1 surrounds the side surface of the first rib a1, and the outer peripheral wall of the first rib a1 is in a positional relationship facing the inner peripheral wall on the lower surface 20b side of the first recess h1.
The second rib a2 surrounds the side surface of the first recess h1 on the lower surface 20b side, and the outer peripheral wall of the first recess h1 on the lower surface 20b side is in a positional relationship of facing the inner peripheral wall of the second rib a2.
The third rib a3 surrounds the side surface of the second rib a2, and the outer peripheral wall of the second rib a2 is in a positional relationship of facing the inner peripheral wall of the third rib a3.
The second recess h2 surrounds the side surface of the third rib a3, and the outer peripheral wall of the third rib a3 is in a positional relationship of facing the inner peripheral wall of the second recess h2 on the lower surface 20b side.
The fourth rib a4 surrounds the side surface of the second recess h2 on the lower surface 20b side, and the outer peripheral wall of the second recess h2 on the lower surface 20b side is in a positional relationship facing the inner peripheral wall of the fourth rib a4.
The outer flange 21b surrounds the side surface of the fourth rib a4, and the outer peripheral wall of the fourth rib a4 is in a positional relationship of facing the inner peripheral wall of the outer flange 21b.

The groove width of the first flange groove portion 12a1 is 3 to 4% smaller than the radial dimension of the inner flange 21a (the portion of the inner flange 21a that faces the first flange groove portion 12a1) (for example, The width of the groove portion 12a1 for one flange: 2.7 mm, the radial dimension of the inner flange 21a: 2.8 mm).
The groove width of the second flange groove portion 12a2 is 3 to 4% smaller than the radial dimension of the outer flange 21b (the dimension of the portion of the outer flange 21b that faces the second flange groove portion 12a2) (for example, the first The lateral width of the groove portion 12a2 for the two flanges: 2.7 mm, and the radial dimension of the outer flange 21b: 2.8 mm).

The groove width of the first recess groove 12b1 is 4 to 5% smaller than the radial dimension of the region (first bottom region h1a) of the first recess h1 facing the first recess groove 12b1 (for example, The groove width of the first recess groove portion 12b1 is 8.6 mm, and the radial dimension of the first bottom region h1a is 9.0 mm.
The groove width of the second recessed groove portion 12b2 is 4 to 5% smaller than the radial dimension of the region (second bottom region h2a) of the second recessed portion h2 facing the second recessed groove portion 12b2 (for example, The groove width of the second recess groove portion 12b2: 8.6 mm, the radial dimension of the second bottom region h2a: 9.0 mm).

The groove width of the first rib groove portion 12c1 is 20% smaller than the radial thickness of the first rib a1 (for example, the groove width of the first rib groove portion 12c1 is 1.6 mm, Thickness: 2.0 mm).
The groove width of the second rib groove portion 12c2 is 20% smaller than the radial thickness of the second rib a2 (for example, the groove width of the second rib groove portion 12c2: 1.6 mm, Thickness: 2.0 mm).
The groove width of the third rib groove portion 12c3 is 20% smaller than the radial thickness of the third rib a3 (for example, the groove width of the third rib groove portion 12c3: 1.6 mm, Thickness: 2.0 mm).
The groove width of the fourth rib groove portion 12c4 is 20% smaller than the radial thickness of the fourth rib a4 (for example, the groove width of the fourth rib groove portion 12c4: 1.6 mm, Thickness: 2.0 mm).

The inner flange 21a, the first rib a1, the first recess h1, the second rib a2, the third rib a3, the second recess h2, the fourth rib a4, and the outer flange 21b are holes 21c formed inside the inner peripheral edge portion. They are arranged concentrically around an axis LX passing through the center of (the circle forming the outer shape of the inner peripheral edge).

A first groove g1 is formed between the inner flange 21a and the first rib a1 on the lower surface 20b, and a second groove g2 is formed between the first rib a1 and the first recess h1. A third groove g3 is formed between the first recess h1 and the second rib a2, a fourth groove g4 is formed between the second rib a2 and the third rib a3, and a third rib a3 is formed. A fifth groove g5 is formed between the second recess h2 and a sixth groove g6 between the second recess h2 and the fourth rib a4, and a fourth rib a4 and the outer flange 21b are formed. A seventh groove g7 is formed between them.

Except for the first concave portion h1 and the second concave portion h2, the horizontal cross section of the upper surface 20a of the heating element 20 has a substantially hollow circular shape, and the vertical cross section of the heating element 20 has an outer peripheral edge portion and an inner peripheral edge portion. It has a substantially convex shape in which a step is provided on the upper surface 20a so as to be thinner than the region.

The heating element 20 is attached to the bottom 11 between the first protrusion 11a and the second protrusion 11b (second space 102), and includes the first rib a1 to the fourth rib a4, the first recess h1, and the second recess. The h2 is pressed against the groove 12 (such as the first rib groove 12c1) and fixed by caulking.

Specifically, the upper surface 20a of the heating element 20 is pushed toward the bottom portion 11 so that the inner flange 21a of the heating element 20 is fitted into the first flange groove 12a1 of the bottom portion 11 and the outer flange 21b of the second portion of the bottom portion 11 is pressed. The first recess h1 is fitted in the flange groove 12a2, the first recess h1 is fitted in the first recess groove 12b1 in the bottom 11, the second recess h2 is fitted in the second recess groove 12b2 in the bottom 11, and the first rib a1 to the first rib a1 The four ribs a4 are fitted into the first rib groove portion 12c1 to the fourth rib groove portion 12c4 in the bottom portion 11, so that the heating element 20 is temporarily fixed to the bottom portion 11 (first fixing).

After the first fixing, the projections (the first projections 11a and the second projections 11b) provided around the area to which the heating element 20 is attached are covered with the flange of the peripheral edge of the heating element 20. Secondary deformation (second fixation) to the bottom portion 11 of the heating element 20 is performed by the deformed caulking.

When the caulking is performed, the protrusion (first space 101 or the third space 103) on the side (first space 101 or third space 103) of the side surface of the protrusion (first protrusion 11a and second protrusion 11b) that is not adjacent to the heating element 20. The jigs (the first caulking jig 51 and the second caulking jig 52) are attached to the first space 101 and the third space 103 so that the protrusions 11a and the second protrusions 11b are not deformed.

The first caulking jig 51 has a substantially columnar shape (for example, a columnar shape), and the second caulking jig 52 has a substantially hollow columnar shape (for example, a hollow columnar shape). It is used as a caulking jig when it is attached to the bottom portion 11.

The 1st crimping jig 51 and the 2nd crimping jig 52 are comprised by the harder material than the 1st protrusion part 11a and the 2nd protrusion part 11b.

Next, a procedure for attaching the heating element 20 to the bottom portion 11 of the pan body 10 will be described.

Insert the heating element 20 into the second space 102 so that the bottom portion 11 of the pan body 10 faces upward (see FIGS. 1, 2, 8, and 9) so that the first protrusion 11a enters the hole 21c. (Step of inserting heating element, see FIGS. 3 and 10).
In this state, the inner flange 21a, the outer flange 21b, the first concave portion h1, the second concave portion h2, and the tip end portions (the portions facing the bottom portion 11) of the first rib a1 to the fourth rib a4 in the heating element 20, It contacts the opening portions of the first flange groove portion 12a1, the second flange groove portion 12a2, the first recess groove portion 12b1, the second recess groove portion 12b2, the first rib groove portion 12c1 to the fourth rib groove portion 12c4 in the bottom portion 11. However, the other regions (first groove g1 to seventh groove g7) do not come into contact with each other.

The upper surface 20a of the heating element 20 is pushed so that the heating element 20 approaches the bottom portion 11, the inner flange 21a of the heating element 20 is fitted into the first flange groove portion 12a1 of the bottom portion 11, and the outer flange 21b of the second portion of the bottom portion 11 is inserted. The first recess h1 is fitted in the flange groove 12a2, the first recess h1 is fitted in the first recess groove 12b1 in the bottom 11, the second recess h2 is fitted in the second recess groove 12b2 in the bottom 11, and the first rib a1 to the first rib a1 The four ribs a4 are fitted into the first rib groove portion 12c1 to the fourth rib groove portion 12c4 in the bottom portion 11, and the first groove g1 to the seventh groove g7 are brought into contact with the bottom portion 11 (pressing step (first fixing), FIG. 4). , See FIG. 11).

Although the groove width for the first flange groove 12a1 and the second flange groove 12a2 provided in the bottom portion 11 is smaller than the thickness of the flange, the pot body 10 is softer than the heating element 20 (the hardness of the heating element 20 is Since it is higher than the hardness of the pan body 10 (at least the bottom portion 11 thereof), the first flange groove portion 12a1 and the second flange groove portion 12a2 function as a guide that bites the inner flange 21a and the outer flange 21b into the bottom portion 11, By the pressing step, the inner flange 21a and the outer flange 21b are bited into the first flange groove portion 12a1 and the second flange groove portion 12a2 in the bottom portion 11.

The first recessed groove 12b1 and the second recessed groove 12b2 provided on the bottom 11 have a groove width smaller than the thickness of the bottom region of the recess, but the pot body 10 is softer than the heating element 20, so that the first recessed portion is formed. The groove portion 12b1 for the second recess and the groove portion 12b2 for the second recess function as a guide that bites the first recess h1 and the second recess h2 into the bottom 11, and the first recess h1 and the second recess h2 are moved to the bottom 11 by the pushing step. In the first recessed groove portion 12b1 and the second recessed groove portion 12b2.

The groove widths of the first rib groove portion 12c1 to the fourth rib groove portion 12c4 provided on the bottom portion 11 are smaller than the thickness of the rib, but the pot body 10 is softer than the heating element 20, so that the first rib groove portion 12c1. The fourth rib groove portion 12c4 functions as a guide that causes the first rib a1 to the fourth rib a4 to bite into the bottom portion 11, and the pushing step causes the first rib a1 to the fourth rib a4 to move to the first portion of the bottom portion 11. The rib groove portion 12c1 to the fourth rib groove portion 12c4 are cut into.

In the present embodiment, the first rib a1 to the fourth rib a4 have a shape in which the thickness of the tip portion and the thickness of the root portion are the same, but in order to surely bite the first rib a1 to the fourth rib a4. The tip may have a shape that is thinner and sharper than the root portion.

The groove portion 12 (first rib groove portion 12c1 and the like) is configured such that the groove width of the groove portion 12 is smaller (narrower) than the thickness of the protrusion (first rib a1 and the like) fitted into the groove portion 12. Therefore, it is necessary to apply force to push the upper surface 20a of the heating element 20 for fitting.
At this time, a region (first bottom region h1a) that is substantially parallel to the bottom 11 of the first recess h1 and faces the first recess groove 12b1 bends in a direction away from the bottom 11 and is substantially parallel to the bottom 11 of the second recess h2. Then, the heating element 20 is fitted into the bottom portion 11 in a state where the region (second bottom region h2a) facing the second recess groove portion 12b2 is bent in the direction away from the bottom portion 11.

The first caulking jig 51 is fitted into the first space 101, and the second caulking jig 52 is fitted into the third space 103 (fitting step, see FIGS. 5 and 12).
The heating element inserting step and the pushing step may be performed after the fitting step.

With the first caulking jig 51 fitted in the first space 101 and the second caulking jig 52 fitted in the third space 103, the first slope 11a1 of the first protrusion 11a and the second protrusion 11b are By pressing the second inclined surface 11b1, the first protrusion 11a and the second protrusion 11b are deformed so as to cover the inner flange 21a and the outer flange 21b of the heat generating element 20, so that the heat generating element 20 inserted into the second space 102 is removed. Fix (caulking process (second fixing), see FIGS. 6 and 13).

The first caulking jig 51 and the second caulking jig 52 are removed (removing step, see FIGS. 7 and 14).

After the fixing by caulking, the surfaces of the first protruding portion 11a, the heating element 20, the second protruding portion 11b, and the third protruding portion 11c are flattened (the tips are substantially in a straight line when viewed from the side). It may be in a mode in which a scraping step (not shown) for scraping the surface of is further performed.

Even after the scraping step, the caulking using the first protrusion 11a (a part of the deformed first protrusion 11a covers and fixes the inner flange 21a of the heating element 20) and the second protrusion 11b. The thickness of the heating element 20 and the size of the peripheral edge portion, the first dimension of the second heating element 20 are fixed so that the caulking (using the deformed second protrusion 11b to cover and fix the outer flange 21b of the heating element 20) is maintained. The height of the 1st protrusion part 11a and the 2nd protrusion part 11b, the scraping amount, etc. are determined.

In the present embodiment, the upper surface 20a of the heating element 20 is pressed to cause the plurality of ring-shaped protrusions (such as the first ribs a1) of the heating element 20 to be provided on the bottom portion 11 of the pan body 10 (for the first rib). (For example, the groove portion 12c1), primary fixing (first fixing) to the bottom portion 11 of the heating element 20 is performed, and by caulking, secondary fixing (first fixing) to the bottom portion 11 of the heating element 20 is performed. 2 fixed) is performed.

For this reason, compared to a mode in which the heating element 20 is fixed to the bottom portion 11 only by crimping without providing the ring-shaped protrusion, the fixing state between the bottom portion 11 and the heating element 20 is easier to maintain.
The ring-shaped protrusions (the inner flange 21a, the outer flange 21b, the first recess h1, the second recess h2, the first rib a1 to the fourth rib a4) are provided in the groove portion 12 (first flange groove portion) provided in the bottom portion 11. 12a1, first recess groove 12b1, second recess groove 12b2, second flange groove 12a2, first rib groove 12c1 to fourth rib groove 12c4), so that the groove 12 is not provided Compared with, the projection can be buckled and easily entered.

Since the groove portion 12 (the first recess groove portion 12b1 and the like) is configured such that the groove width of the groove portion 12 is smaller than the thickness of the protrusion (the first recess h1 and the like) fitted into the groove portion 12, The heating element 20 is fitted into the bottom portion 11 in a state in which the first bottom region h1a of the first recess h1 is bent in a direction away from the bottom portion 11 and the second bottom region h2a of the second recess h2 is bent in a direction away from the bottom portion 11. .
The amount of bending of the bent portions (the first bottom region h1a and the second bottom region h2a) changes due to heat, and the change in the amount of bending causes the difference in the coefficient of thermal expansion between the pan body 10 and the heating element 20. It is possible to prevent the generation of abnormal noise.

For example, when the temperature of the bottom surface of the pan body 10 rises such that the cooking device 1 becomes empty and the heating element 20 expands more than the pan body 10, the first bottom area h1a and the second bottom area h1a. The amount of deflection of h2a increases (see FIG. 15).
Further, when the temperature of the bottom surface of the pan body 10 is lowered such as when the cooker 1 is put in water and the heating element 20 contracts more than the pan body 10, the first bottom area h1a and the second bottom area h2a are The amount of bending becomes small (see FIG. 16).
11 to 14 show a moderate amount of bending, FIG. 15 shows a state where the heating element 20 expands and has a larger amount of bending than the state of FIG. 14, and FIG. 14 shows a state in which the amount of flexure is smaller than that in the state of No. 14 due to contraction.

That is, the deformation of the recesses (the first bottom region h1a and the second bottom region h2a) absorbs the difference in expansion between the pan body 10 and the heating element 20, and even if the pan body 10 and the heating element 20 are greatly expanded or contracted, the heating element 20 and the pan may be expanded. It is possible to easily maintain the fixed state of the main body 10.

In addition, since the contact area between the bottom portion 11 and the heating element 20 can be increased by the amount of the plurality of ring-shaped projections, the heat conduction efficiency from the heating element 20 to the pan body 10 can be increased.

Further, the protrusion amount (depth) of the ring-shaped protrusions (first rib a1 to fourth rib a5) is increased to increase the amount of bite into the bottom portion 11 to strengthen the primary fixing. Can be done easily.

Also, due to the caulking, the inner end of the inner flange 21a is covered with the deformed first protrusion 11a, and the outer end of the outer flange 21b is covered with the deformed second protrusion 11b. This makes it difficult for water or the like to enter through the gap between the bottom portion 11 and the heating element 20.
Further, by using the first caulking jig 51 and the second caulking jig 52, there is an advantage that the deformation direction due to caulking can be easily guided in a predetermined direction (shape).

DESCRIPTION OF SYMBOLS 1 Cooking device 10 Pan main body 11 Bottom part 11a-11c 1st protrusion part-3rd protrusion part 11a1 1st slope 11b1 2nd slope 12 Groove part 12a1, 12a2 1st flange groove part, 2nd flange groove part 12b1, 12b2 1st recessed part Groove part, second groove part 12c1 to 12c4 first rib groove part to fourth rib groove part 20 heating element 20a upper surface of heating element (surface on the side not contacting the bottom portion, second surface)
20b Lower surface of heating element (surface contacting bottom, first surface)
21a Inner flange 21b Outer flange 21c Holes 51, 52 1st crimping jig, 2nd crimping jig 101-103 1st space-3rd space a1-a4 1st rib-4th rib g1-g7 1st groove-the 1st 7 groove h1, h2 first concave portion, second concave portion h1a, h2a first bottom region, second bottom region LX axis passing through the center of the hole formed inside the inner peripheral edge portion

Claims (7)

With the pot body,
Having a hardness higher than at least the bottom of the pot body, and comprising a heating element attached to the bottom,
A ring that protrudes toward the bottom is integrally formed on a first surface of the heating element that is in contact with the bottom.
A groove portion having a groove width smaller than the thickness of the ring is provided in a region of the bottom portion facing the ring,
Depress the second surface of the heating element opposite to the first surface so that the ring bites into the groove, and deform the protrusion provided on the bottom to cover the peripheral edge of the heating element. The cooker using an electromagnetic induction heating method, wherein the heating element is fixed to the bottom portion by caulking. As the ring, the heating element is provided with a recess having the second surface recessed, the first surface protruding, and a U-shaped cross section.
The groove part for recesses which has a groove width smaller than the thickness of the area|region which opposes the said bottom part in the said recessed part is provided in the area|region which opposes the said recessed part in the said bottom part, It is characterized by the above-mentioned. Cooker. The cooker according to claim 2, wherein the groove width of the groove portion for recess is 4% smaller than the radial dimension of a region of the recess facing the bottom portion. The heating element is provided with a rib as the ring,
The rib groove portion having a groove width smaller than the radial thickness of the rib is provided in a region of the bottom portion facing the rib as the groove portion. Cooker. The cooker according to claim 4, wherein the groove width of the rib groove is 20% smaller than the radial thickness of the rib. The heating element has a hollow disc shape, and has two or more rings.
The cooker according to claim 1, wherein the circular shape of the inner peripheral edge of the hollow disk shape and the two or more rings are arranged concentrically. A heating element insertion step of inserting a heating element having a hollow plate shape between the protrusions used for caulking provided on the bottom of the pan body,
A ring that is integrally formed on the first surface of the heating element that is in contact with the bottom portion and that projects toward the bottom portion bites into a groove portion that is provided on the bottom portion and has a groove width smaller than that of the ring, A pressing step of pressing a second surface of the heating element opposite to the first surface;
A method of manufacturing a cooker using an electromagnetic induction heating method, comprising: a caulking step of performing caulking by deforming the protruding portion so as to cover the outer peripheral portion and the inner peripheral portion of the hollow plate shape. .

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