JPH07113529A - Plane heater for heating cooker - Google Patents

Abstract

PURPOSE:To improve the heat insulating property of a heat shielding plate by a method wherein a plane heater is provided with a plate type heat source, pushed against the heating surface of a heating cooker, the heat shielding plate made of a metal, and projections for supporting the plate type heat source. CONSTITUTION:A plate type heat source 23 is pushed against the heating surface 12a of a heating cooker. The metallic heat shielding plate 22 is provided between the plate type heat source 23 and the bottom surface of a metallic casing 21 and is supported through a projection (cut-and-raised piece) 30 provided on the heat shielding plate 22 projectingly. The heat shielding plate 22 supports the plate type heat source 23 through the cut-and-raised piece 30 whereby a contacting area of the heat shielding plate 22 with the plate type heat source 23 becomes extremely small. Accordingly, the amount of heat, transferred from the plate type heat source 23 to the heat shielding plate 22 through conduction, becomes small and, therefore, the amount of heat transferred from the heat shielding plate 22 to the casing 21 becomes small also. According to this method, the heat shielding property (heat insulating property) of the heat shielding plate 22 can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat heater used as a heat source for a heating cooker such as an oven grill range.

[0002]

2. Description of the Related Art For example, in an oven grill range, an external flat heater having a structure in which a bottom surface of an inner box forming a heating chamber is used as a heat radiation surface is used as a lower heater for heating food from the lower side. ing.

This flat heater is mainly composed of a plate-shaped heat source having a structure in which a core mica plate wound with a nichrome wire is sandwiched between two insulating mica plates for insulation from other members. The heat source is pressed against the outer bottom surface of the inner box forming the heating chamber to heat the bottom surface, and the bottom surface of the heated inner box heats the food by radiation.

Conventionally, such a flat heater is shown in FIG.
And the structure shown in FIG. 13 and FIGS.
There is one with the structure shown in. The planar heater 1 shown in FIG. 12 and FIG. 13 is a plate-shaped heat source by attaching a plate-shaped heat source 2 to a rectangular container-shaped casing 4 via a heat insulator 3 made of glass fiber and fixing the casing 4 to an inner box. 2 is pressed against the bottom surface of the inner box. Also, FIG.
4 and the plane heater 5 shown in FIG. 15 attaches the plate-shaped heat source 2 to the casing 4 via the heat shield plate 6 made of metal, and fixes the casing 4 to the bottom surface of the inner box.
It is a structure that presses against the bottom of the inner box. The heat insulator 3 and the heat shield plate 6 have a function of blocking heat conduction from the plate-shaped heat source 2 to the casing 4 and pressing the plate-shaped heat source 2 against the bottom surface of the inner box.

[0005]

In the flat heater 1 shown in FIGS. 12 and 13, the heat insulating body 3 is made of glass fiber, so that the heat insulating property is excellent. However, since the heat insulating body 3 is manufactured by integrating glass fibers, the thickness of the heat insulating body 3 varies widely, and when the plate-shaped heat source 2 is pressed against the bottom surface of the inner box, the pressing force varies, and the plate-shaped heat source The amount of heat transfer from 2 to the bottom of the inner box varies. In addition, when the flat heater 1 is disassembled and discarded, the glass fiber heat insulator 3 is difficult to recycle, is incombustible and cannot be incinerated, and eventually becomes incombustible waste.

On the other hand, in the flat heater 5 shown in FIGS. 14 and 15, the metal heat shield plate 6 is made of the glass fiber heat insulator 3.
Since there is no such dimensional variation, there is no variation in the pressing force of the plate heat source 2 on the bottom surface of the inner box, and therefore there is little variation in the amount of heat transfer from the plate heat source 2 to the bottom surface of the inner box, and recycling Is easy. However, the metal heat shield 6
Has a thermal conductivity of 100 times or more higher than that of the glass fiber heat insulator 3, so that the heat shield plate 6 contacting the plate heat source 2 in a large area is connected to the plate heat source 2 from the heat shield plate 6. The amount of heat transfer increases and the heat insulation is poor.

As described above, the heat insulating body 3 made of glass fiber is excellent in heat insulating property, but finally it becomes non-combustible waste and adversely affects the environment. Therefore, avoid using the heat insulating body 3 made of glass fiber. It is preferable to use a heat shield plate 6 made of metal. However, the conventional metal heat shield plate 6 is inferior in heat insulation. Therefore, there is a strong demand for the development of a planar heater having excellent heat insulating properties while using a heat shield plate made of a metal plate.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a flat heater for a heating cooker excellent in heat insulation while using a metal heat shield plate.

[0009]

A flat heater for a heating cooker according to the present invention is provided with a metal casing formed in a flat box shape, and the casing is provided on the casing, and the casing is attached to a heating surface of the heating cooker. A plate-shaped heat source pressed against the heating surface, a metal heat shield plate provided between the plate-shaped heat source and the bottom surface of the casing, and the plate-shaped heat source supported by the heat shield plate. And a supporting protrusion that is provided in a protruding manner.

In this case, the supporting protrusion is formed by a cut and raised piece formed by cutting and raising the heat shield plate in an inclined shape, and the cut and raised piece is elastic in a direction in which the cut and raised piece is bent by contact with the heating surface of the plate heat source. It is possible to deform and press the plate-shaped heat source against the heating surface by the restoring elastic force in the standing direction. Further, in order to increase the strength of the heat shield plate, it is preferable that the cut-and-raised piece forming the supporting protrusion is continuously cut and raised in substantially the entire width direction of the heat shield plate.

In order to minimize the amount of heat transfer by radiation from the plate heat source to the heat shield plate, the heat shield plate can be plated. In addition, in order to minimize the amount of heat transmitted from the plate heat source to the heat shield plate by radiation in a limited space, the distance between the heat shield plate and the bottom surface of the casing should be smaller than the distance between the plate heat source and the heat shield plate. The interval dimension can be set larger.

[0012]

Since the contact area of the heat shield plate with the plate-shaped heat source is small, even if the heat shield plate is made of a metal having high thermal conductivity,
The amount of heat transferred from the plate heat source to the heat shield plate is small, and the heat insulation is improved.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment in which the present invention is applied to an oven grill range will be described below with reference to FIGS. The overall structure of the oven grill range is shown in FIG. In the figure, 11 is an outer box, 12 is an inner box, and the inside of this inner box 12 is a heating chamber 13. A magnetron 15 for supplying microwaves into the heating chamber 13 via the waveguide 14 is provided on the outer side of the inner box 12.
Is provided. Further, a lamp heater 16 is arranged inside the upper part of the inner box 12, and a flat heater 17 according to the present invention is arranged on the outer bottom surface. The flat heater 17 is configured to use the bottom surface of the inner box 12 as a heating surface 12a, and heats the heating surface 12a to heat food by radiant heat from the heating surface 12a.

At the bottom of the flat heater 17, the mounting frame 1 is attached.
A motor 19 is attached via 8. The rotary shaft 19a of the motor 19 is inserted into the flat heater 17 and projects into the inner box 12 (heating chamber 13).
A turntable 20 is attached to the upper end of a. Then, the food to be heated is placed on the turntable 20 and rotated by the turntable 20, whereby uneven heating of the food is prevented.

As shown in FIGS. 2 and 5, the flat heater 17 is a casing 2 formed in the shape of a flat rectangular container.
1. A heat shield plate 22 disposed in the casing 21 and a plate-shaped heat source 23 supported by the heat shield plate 22 so as to be located on the open upper surface portion of the casing 21.
As shown in FIG. 4, the plate-shaped heat source 23 includes a core mica plate 25 around which a heating wire 24 such as a nichrome wire is wound.
The core mica plates 25 are arranged side by side and sandwiched by two insulating mica plates 26 for insulating from other members. The casing 21 and the heat shield plate 22 are formed of a thin metal plate, and the surfaces thereof are plated for light reflection. Radiation heat (infrared rays) from the plate-shaped heat source 23 is reflected by this plating to prevent the casing 21 and the heat shield plate 22 from being heated by the radiant heat from the plate-shaped heat source 23 as much as possible.

The casing 21, the heat shield plate 22 and the plate heat source 23 are connected to each other by eyelets 27 at the four corners. In this case, as shown in FIG. 1, the inner diameters of the through holes 21a, 22a, 23a formed in the casing 21, the heat shield plate 22, and the plate-shaped heat source 23 for passing the eyelet 27 are larger than the outer diameter dimension of the eyelet 27. Is also formed with a large diameter. As a result, the heat shield plate 22 and the plate-shaped heat source 23 can freely move laterally with respect to the casing 21, and the casing 21 when the plate-shaped heat source 23 generates heat,
The difference in the amount of thermal expansion between the heat shield plate 22 and the plate-shaped heat source 23 can be absorbed.

The flat heater 17 is mounted on the mounting seat 28 fixed to the lower surface of the heating surface 12a of the inner box 12 and the casing 2
It is attached by tightening the bottom surface of 1 with screws 29. By mounting the casing 21 on the mounting seat 28, the plate-shaped heat source 23 is pressed against the heating surface 12a of the inner box 12, and the heat generated by the heating wire 24 is transferred to the heating surface 12a.

Here, the support structure of the plate heat source 23 by the heat shield plate 22 will be described. That is, in the heat shield plate 22,
As shown in FIG. 5, the cut-and-raised pieces 3 serving as a plurality of supporting protrusions.
0 is formed by cut and raised, and cut and raised piece 3
A plurality of conical projections 33 projecting downward are formed by drawing on the cross section 32 between the elongated holes 31 formed by cutting and raising 0. In this case, the protruding height H1 of the cut and raised piece 30 is set higher than the protruding height H2 of the protrusion 33.

The cut-and-raised pieces 30 are cut and raised so as to be continuous over substantially the entire width of the heat shield plate 22, and in the cut-and-raised state, they are inclined as shown in FIG. The upper end of the cut-and-raised piece 30 is bent so as to be inclined obliquely downward, and the bent portion 30b bent to form the bent piece 30a is the top of the cut-and-raised piece 30.

The heat shield plate 22 is supported on the inner bottom surface of the casing 21 by bringing the projection 33 into contact with the inner bottom surface of the casing 21, and the bent portion 30b, which is the top of the cut and raised piece 30, is formed into a plate shape. The plate-shaped heat source 23 is supported by being brought into contact with the heat source 23. In this case, as shown in FIG. 3, both ends in the longitudinal direction of the bent portion 30b contact the insulating mica plate 26 below the plate-shaped heat source 23 at a portion deviated from the portion where the heating wire 24 is arranged. I have come into contact with them.

Here, in a state before the casing 21 is attached to the mounting seat 28, the distance L1 between the inner bottom surface of the casing 21 and the upper surface of the plate-shaped heat source 23 is determined by the lower surface of the mounting seat 28 and the heating surface of the inner box 12. It is set to be longer than the distance L2 from 12a. As a result, the casing 21 is attached to the mounting seat 2
8, the cut-and-raised piece 30 is elastically deformed from the state shown by the solid line in the figure to the direction in which it goes down (shown by the arrow A in FIG. 1) to the state shown by the chain double-dashed line. Plate-like heat source 2 due to the restoring elastic force to return to the state of
3 is pressed against the heating surface 12a of the inner box 12. in this case,
The cut-and-raised piece 30 does not elastically deform in the arrow A direction alone, but elastically deforms so as to rotate in the arrow A direction around the protrusion 33 together with the crosspiece 32. In FIG. 5, 34 is a lead wire connected to both ends of the heating wire 24.

According to the flat heater 17 constructed as described above, the following effects can be obtained. That is,
Since the heat shield plate 22 supports the plate-shaped heat source 23 by the cut-and-raised pieces 30, the contact area of the heat shield plate 22 with the plate-shaped heat source 23 is extremely small. Therefore, the plate-shaped heat source 23 to the heat shield plate 2
Since the amount of heat transferred to the heat conducting plate 2 by 2 is small, and therefore the amount of heat transferred from the heat shield plate 22 to the casing 21 is also small, the heat shield property (heat insulating property) of the heat shield plate 22 is improved.

In this case, since the heat shield plate 22 is supported by the bottom surface of the casing 21 via the projection 33, the contact of the heat shield plate 22 with the casing 21 is close to a point contact. Therefore, the contact area of the heat shield plate 22 with the casing 21 is also extremely small, and the amount of heat transferred by conduction from the heat shield plate 22 to the casing 21 is also extremely small.

The distance L1 between the heat shield plate 22 and the plate-shaped heat source 23 is greater than the distance L2 from the bottom surface of the casing 21.
Is set longer than. For this reason, in the limited space, the plate-shaped heat source 23, which has a high temperature, can be removed from the heat shield plate 2.
It is possible to minimize both the heat transfer by radiation to the casing 2 and the heat transfer by radiation from the heat shield plate 22 to the casing 21. In this case, since the heat shield plate 22 is plated and the radiant heat from the plate heat source 23 is reflected by the plating, the amount of heat transferred from the plate heat source 23 to the heat shield plate 22 is further reduced.

Moreover, the cut-and-raised pieces 30 are cut and raised in an inclined shape, and when the flat heater 17 is attached to the heating surface 12a,
Since the cut-and-raised piece 30 is elastically deformed in the lying direction and the restoring elastic force presses the plate-shaped heat source 23 against the heating surface 12a, the plate-shaped heat source 23 is always heated with an appropriate pressing force.
It can be kept pressed against a. Therefore, the thermal conductivity from the plate heat source 23 to the heating surface 12a is improved, and the heat transfer efficiency is improved.

Furthermore, since the cut-and-raised pieces 30 are continuously cut and raised over the entire width of the heat-shielding plate 22, the heat-shielding plate 22 becomes stronger in strength and one cut-and-raised piece is formed. Three
The number of protrusions 33 for 0 is at least 30
The plate-shaped heat source 23 can be pressed against the heating surface 12a in the entire longitudinal direction.

On the other hand, since the bent portion 30b of the cut-and-raised piece 30 is in contact with the plate-shaped heat source 23, the contact portion of the cut-and-raised piece 30 with the plate-shaped heat source 23 is an arc surface portion. Therefore, unlike the case where the upper end of the cut and raised piece that is simply cut and raised is brought into contact with the plate-shaped heat source 23, there is no risk of damaging the insulating mica plate 26 below the plate-shaped heat source 23, and a thin insulating mica is used. Board 2
6 (thickness 0.3 to 0.5 mm) is broken, and the cut and raised piece 30 comes into contact with the heating wire 24, causing no electric leakage.

Further, at both ends in the longitudinal direction of the bent portion 30b,
There is a cutting edge when the cut and raised piece 30 is cut and raised. However, since both ends in the longitudinal direction of the bent portion 30b are in contact with the plate-shaped heat source 23 at the portions deviating from the positions where the heating wires 24 are arranged, the cutting edges existing at the both ends in the longitudinal direction of the bent portion 30b are assumed. Even if the insulating mica plate 26 on the lower side of the plate-shaped heat source 23 is broken, the cut-and-raised pieces 30 do not come into contact with the heating wire 24.

FIGS. 7 to 11 show second to sixth embodiments of the present invention. In these drawings, the same parts as those in FIG. In the second embodiment shown in FIG. 7, cut-and-raised pieces 36 and 37 are formed by cutting and raising the heat-shielding plate 35 alternately downward and upward. The heat shield plate 35 is supported on the bottom surface of the casing 21 by bringing the cut-and-raised pieces 36 facing downward into contact with the bottom surface of the casing 21. Then, the plate-shaped heat source 23 is formed by the upwardly facing cut-and-raised piece 37 as a supporting protrusion.
Is supporting.

In the third embodiment shown in FIG. 8, a leg piece 39 is formed on the heat shield plate 38 by bending the peripheral edge of the heat shield plate downward, and a plurality of cut-and-raised parts serving as support projections are formed. A piece 40 is cut and raised vertically with the piece facing upward. The heat shield plate 38 is supported by the casing 21 by bringing the leg pieces 39 into contact with the bottom surface of the casing 21, and supports the plate-shaped heat source 23 by the cut and raised pieces 40.

In the fourth embodiment shown in FIG. 9, trapezoidal protrusions 42 and 43 are alternately formed on the heat shield plate 41 downward and upward. This heat shield plate 41
Is supported on the bottom surface of the casing 21 by bringing the downwardly convex projection 42 into contact with the bottom surface of the casing 21. Then, the plate-shaped heat source 23 is supported by the projecting portion 43, which uses the projecting portion 43 projecting upward as a supporting projecting portion.

In the fifth embodiment shown in FIG. 10, the heat shield plate 44 has a corrugated portion 4 as a support protrusion protruding upward.
5 is drawn. A corrugated protrusion 46 protruding upward is formed on the bottom surface of the casing 21 by drawing. The heat shield plate 44 is supported by the casing 21 by being placed on the protrusion 46, and the corrugated portion 47 supports the plate heat source 23.

In the sixth embodiment shown in FIG. 11, corrugated portions 48 and 49 are alternately drawn on the heat shield plate 47 so as to be convex downward and convex upward.
Therefore, the heat shield plate 47 has a substantially corrugated cross section. The heat shield plate 47 is supported by the casing 21 by bringing a downwardly convex corrugated portion 48 into contact with the bottom surface of the casing 21, and a plate shape is formed by the corrugated portion 49 with the upwardly convex corrugated portion 49 as a supporting protrusion. It supports the heat source 23.

Even if the heat shield plates 35, 38, 41, 44 and 47 are constructed as in the second to sixth embodiments, the contact areas of both the plate heat source 23 and the casing 21 are small. As in the case of the first embodiment, the effect of improving the heat insulating property can be obtained. Particularly, in the fourth embodiment shown in FIG. 9, since the plate-shaped heat source 23 is supported by the flat upper end surface of the protrusion 43, the lower insulating mica plate 26 is not scratched. In this case, the second one shown in FIG. 7 and FIG.
In addition, in the third embodiment, the horizontal piece is bent and formed at the tips of the cut and raised pieces 37 and 40, and the plate-shaped heat source 2 is formed by this horizontal piece.
You may make it support 3.

In each of the above embodiments, the description has been made by applying it to the flat heater attached to the bottom surface (heating surface 12a) of the inner box 12, but it may be applied to the flat heater attached to the upper surface of the inner box. Alternatively, the eyelet 27 may be replaced with a stepped shaft fixed to the casing, and the heat shield may be supported by the stepped part of the stepped shaft.

In addition, the present invention is not limited to the embodiments described above and shown in the drawings, and is not limited to, for example, a flat heater of an oven grill range, but can be widely applied to a flat heater of a heating cooker in general. The present invention can be variously modified and implemented without departing from the above.

[0037]

As described above, according to the flat heater of the heating cooker of the present invention, the metal heat shield plate is used as a member for heat insulation, so that the heat insulator made of glass fiber is used. In contrast, it is possible to recycle and does not have an adverse effect on the environment.Moreover, the supporting projection is provided on the metal heat shield plate to support the plate-shaped heat source. As a result, the contact area of the heat shield plate to the heat source becomes smaller and the heat transfer amount from the plate heat source to the heat shield plate becomes smaller.
The amount of heat transmitted from the plate-shaped heat source to the casing through the heat shield plate and escaping to the outside is small, and excellent heat insulating properties can be obtained despite the use of the metal heat shield plate.

According to the plane heater of the heating cooker of the present invention, the heat shield plate and the plate-shaped heat source are connected to the casing so as to be movable relative to each other, so that the three members have a difference in thermal expansion. Even if it exists, this can be absorbed, and as a result, there is no possibility that a large thermal stress will occur between the above three members and cause deformation or damage.

According to the flat heater of the heating cooker of the present invention, the supporting projection of the heat shield plate is composed of the cut and raised piece cut and raised in an inclined state, and the cut and raised piece is directed to the heating surface of the plate-shaped heat source. The elastic heat is applied to the heating surface to press the plate heat source against the heating surface, so that the plate heat source is always pressed against the heating surface with an appropriate pressure, The heat conduction of the is improved.

According to the flat heater of the heating cooker of the present invention, since the cut-and-raised pieces forming the supporting projections are formed over substantially the entire width direction of the heat shield plate, the plate thickness of the heat shield plate is small. Also, the strength of the heat shield plate is improved, and the plate-shaped heat source can be satisfactorily pressed against the heating surface.

According to the flat heater of the heating cooker of the present invention, the tip end of the cut-and-raised piece that constitutes the support protrusion is bent, and the bent portion for bending is in contact with the plate-shaped heat source. There is no risk of the heat source being damaged by the cut and raised pieces.

According to the flat heater of the heating cooker of the present invention, since the heat shield plate is plated for light reflection, the heat shield plate receives less heat due to radiation from the plate-shaped heat source, The heat insulation is further improved.

According to the plane heater of the heating cooker of the present invention, the distance between the plate-shaped heat source and the heat shield is set larger than the distance between the bottom of the casing and the heat shield. It is possible to reduce the amount of heat that is propagated by radiation from the plate heat source to the heat shield plate in a limited space.

According to the flat heater of the heating cooker of the present invention, since both ends of the supporting protrusion in the longitudinal direction are in contact with each other at a portion deviating from the portion where the heating wire of the plate-shaped heat source is disposed, the length of the supporting protrusion is long. Even if there are edges at both ends in the direction and the plate-shaped heat source is damaged by the edges, there is no risk of the support projection contacting the heating wire, and there is no risk of electrical leakage.

[Brief description of drawings]

FIG. 1 is a partial vertical sectional side view of a flat heater showing a first embodiment of the present invention.

FIG. 2 is a vertical sectional side view of the entire plane heater.

FIG. 3 is a partial vertical sectional side view taken along line III-III in FIG.

FIG. 4 is an exploded perspective view of a plate heat source.

FIG. 5 is an exploded perspective view of a flat heater.

FIG. 6 is a vertical sectional view of an oven grill range.

FIG. 7 is a view corresponding to FIG. 1 showing a second embodiment of the present invention.

FIG. 8 is a diagram corresponding to FIG. 1 showing a third embodiment of the present invention.

FIG. 9 is a view corresponding to FIG. 1 showing a fourth embodiment of the present invention.

FIG. 10 is a view corresponding to FIG. 1 showing a fifth embodiment of the present invention.

FIG. 11 is a diagram corresponding to FIG. 1 showing a sixth embodiment of the present invention.

FIG. 12 is a view corresponding to FIG. 5 showing a conventional flat heater.

FIG. 13 is a view equivalent to FIG.

FIG. 14 is a view corresponding to FIG. 5 showing another conventional planar heater.

FIG. 15 is a view equivalent to FIG.

[Explanation of symbols]

Reference numeral 12 is an inner box, 12a is a heating surface, 13 is a heating chamber, 17 is a flat heater, 21 is a casing, 22 is a heat shield plate, 23 is a plate-shaped heat source, 24 is a heating wire, 25 is a core mica plate, and 26 is insulating. Mica plate, 30 is a cut and raised piece (supporting protrusion), 33 is a protrusion, 3
Reference numeral 5 is a heat shield plate, 37 is a cut and raised piece (supporting protrusion), 38 is a heat shield plate, 39 is a cut and raised piece, 40 is a cut and raised piece (supporting protrusion), 41 is a heat shield plate, and 43 is a protrusion. (Supporting protrusion), 44 is a heat shield plate, 46
Is a protrusion (supporting protrusion), 47 is a heat shield plate, and 48 is a corrugated portion (supporting protrusion).

Claims (13)

[Claims] 1. A metal casing formed in a flat box shape, a plate-shaped heat source which is provided on the casing and is pressed against the heating surface of the heating cooker by attaching the casing to the heating surface. A heat shield plate made of metal provided between the plate heat source and the bottom surface of the casing, and a supporting protrusion provided on the heat shield plate so as to abut the plate heat source and support the plate heat source. A flat heater for a heating cooker, which includes a section. 2. The cooking according to claim 1, wherein the plate-shaped heat source and the heat shield plate are connected to the casing such that they can move freely relative to each other in order to absorb the difference in thermal expansion. Flat heater. 3. The support projection comprises a cut-and-raised piece formed by cutting and raising the heat shield plate in an inclined shape, and the cut-and-raised piece is elastically deformed in a direction in which the cut-and-raised piece is bent by contact with a heating surface of the plate-shaped heat source. The flat heater of the heating cooker according to claim 1 or 2, wherein the plate-shaped heat source is pressed against the heating surface by the restoring elastic force in the standing direction. 4. The heating piece according to claim 3, wherein the cut-and-raised piece forming the support projection is formed by cutting and raising the heat-shielding plate continuously over substantially the entire widthwise direction of the heat-shielding plate. A flat heater for a cooker. 5. The heating cooker according to claim 1, wherein a bottom surface of the casing is provided with a protrusion that abuts against the heat shield plate and supports the heat shield plate. Flat heater. 6. The heat shield plate is formed with a plurality of protrusions projecting to the side opposite to the supporting protrusions, and the heat shield plate is supported by the bottom surface of the casing via the protrusions. A flat heater for a heating cooker according to any one of claims 1 to 4. 7. The heat shield plate is formed with a plurality of cut-and-raised pieces so as to project to opposite sides, and the heat shield plate is supported by the bottom surface of the casing via the cut-and-raised pieces that project to one side. At the same time, the cut-and-raised piece projecting to the other side is brought into contact with the plate-shaped heat source as a support projection, and the flat heater of the heating cooker according to any one of claims 1 to 4. 8. The flat heater for a heating cooker according to claim 1, wherein the support protrusion has a flat portion in contact with the plate-shaped heat source. 9. The tip of the cut-and-raised piece forming the support projection is bent, and the bent portion for bending is in contact with the plate-shaped heat source. 7. A flat heater for a heating cooker according to any one of 7. 10. The distance between the heat shield plate and the bottom surface of the casing is set to be larger than the distance between the plate heat source and the heat shield plate. The flat heater of the heating cooker according to. 11. The heat shield plate is formed to have a substantially corrugated cross section, and is supported on the bottom surface of the casing through a corrugated portion that is convex on one side, and the corrugated portion that is convex on the other side is used as a supporting protrusion for a plate-shaped heat source. The flat heater for a heating cooker according to claim 1 or 2, which is in contact with the flat heater. 12. The plate-shaped heat source is constituted by sandwiching a heating wire between insulating plates such as mica plates, and both ends in the longitudinal direction of the supporting protrusion are located at a portion of the plate-shaped heat source that is out of the area where the heating wire is arranged. The flat heater for a heating cooker according to any one of claims 1 to 11, which is in contact with a plate-shaped heat source. 13. The surface of the heat shield plate on the plate-shaped heat source side is plated for light reflection.
A flat heater for a heating cooker according to any one of 1 to 12.