Below referring to figs. 1 through Fig. 6, to being applicable to the 1st of the microwave oven that bakes of the present invention
Embodiment describes.
The overall structure that can bake microwave oven as shown in Figure 6.In the figure, the 11st, outer container, the 12nd, interior case, inside of case 12 is heating chamber 13 in this.Dispose magnetron 15 so that in heating chamber 13, supply with microwave in the outside portion of interior case 12 through waveguide 14.In addition, be provided with fluorescent tube heater 16 in the upper inner of interior case 12, and on outer bottom, be provided with plane heater 17 of the present invention.This plane heater 17 is made the structure that the bottom surface of interior case 12 is used as heating surface 12a, by the heating of heating surface 12a, is used to take heated food from the radiant heat of this heating surface 12a.
In the bottom of above-mentioned plane heater 17, motor 19 is installed through installing rack 18.The rotating shaft 19a of this motor 19 passes plane heater 17 and stretches out in interior case 12 (heating chamber 13), in the upper end of this rotating shaft 19a turntable 20 is housed.The food that must heat places on this turntable 20, is driven by this turntable 20 to rotate, thereby prevents the inhomogeneous of food heating.
As Fig. 2 and shown in Figure 5, above-mentioned plane heater 17 comprises: form the container-like housing of flattened rectangular 21, be located at the thermal insulation board 22 in this housing 21, and the tabular thermal source 23 of upper position that is positioned at the opening of housing 21 by thermal insulation board 22 supportings.The concrete structure of above-mentioned tabular thermal source 23 as shown in Figure 4, be wound with nichrome wire etc. heating line 24 25 two of mica central layers side by side, in order to make this two killinites central layer 25 and other members insulation, they are clipped in wherein by two insulating mica plates 26.Above-mentioned housing 21 and thermal insulation board 22 are processed by the metallic plate of thinner thickness, and there is the coating of reflection from the radiant heat (infrared ray) of tabular thermal source 23 on its surface, prevent that as far as possible housing 21 and thermal insulation board 22 are by the radiant heat heating from tabular thermal source 23.
Aforesaid housing 21, thermal insulation board 22 and tabular thermal source 23 interosculate by buttonhole 27 in 4 bights.This moment, in order to pass buttonhole 27, the internal diameter size that is formed at through hole 21a, 22a on housing 21, thermal insulation board 22, the tabular thermal source 23,23a was bigger than the outside dimension of buttonhole 27 as shown in Figure 1.Like this, thermal insulation board 22 can laterally move freely mutually with tabular thermal source 23 relative housings 21, can absorb thermal expansion amount poor of housing 21, thermal insulation board 22 and tabular thermal source 23 at tabular thermal source 23 adstante febres.
Above-mentioned plane heater 17 is fastened on the bottom surface of housing 21 on the mount pad 28 with screw 29 and is mounted, and mount pad 28 be fixed on the downside of heating surface 12a of case 12.Be installed on this mount pad 28 by housing 21, tabular thermal source 23 is urged on the heating surface 12a of interior case 12, and the heat that heating line 24 is sent passes to heating surface 12a.
At this, the supporting structure of the tabular thermal source 23 that adopts thermal insulation board 22 is described.On thermal insulation board 22, as shown in Figure 5, by having cut a plurality of perverse 30 that is processed to form as support projection portion, and, perverse 30 because of the strip parts 32 of having cut 31 of the slotted holes that produce of processing on, be processed to form conical a plurality of projections 33 of giving prominence to downwards by pull and stretch.At this moment, perverse 30 projecting height is set at the projecting height that is higher than projection 33.
Above-mentioned each the perverse 30 roughly whole Width at thermal insulation board 22 cut continuously, and it has been cut state and has been as shown in Figure 1 heeling condition.And the upper end of thorn sheet 30 bends obliquely to oblique below, forms bent sheet 30a, so kink 30b becomes perverse 30 top, top.
Like this, thermal insulation board 22 is supported on the inner bottom surface of this housing 21 by making its projection 33 and the inner bottom surface butt of housing 21, and is that kink 30b and tabular thermal source 23 butts support this tabular thermal source 23 by making perverse 30 top, top.In the case, the length direction both ends of kink 30b are connected to and are equipped with the position of staggering in the position of heating line 24 with the insulating mica plate 26 of downside as shown in Figure 3.
Here, will be set in the distance L 1 between the upper side of the inner bottom surface of the housing 21 under the state before housing 21 is installed in mount pad 28 and tabular thermal source 23 greater than the distance L 2 between the heating surface 12a of the downside of mount pad 28 and interior case 12.Like this, when being installed in housing 21 on the mount pad 28, perverse 30 from state shown in Fig. 1 solid line to the strain of direction generation shown in Fig. 1 arrow A, become state shown in the two point dotted line, and perverse 30 generation is urged to tabular thermal source on the heating surface 12a of interior case 12 from the restorable recovery elastic force of this elastic deformation.At this moment, perverse 30 is not separately to arrow A direction generation strain, but with strip parts 32, the form generation strain that rotates for middle mind-set arrow A direction with projection 33.
Again, in Fig. 5, the 34th, the lead that is connected with the two ends of heating line 24.
If adopt the as above plane heater 17 of structure, can obtain following effect.
Thermal insulation board 22 makes thermal insulation board 22 relative plates by the perverse 30 tabular thermal source 23 of supporting
Thermal insulation board 22 makes the contact area of the tabular relatively thermal source 23 of thermal insulation board 22 become minimum by the perverse 30 tabular thermal source 23 of supporting.Therefore, pass seldom, also reduce thereby pass toward the heat output of housing 21, so can improve the thermal insulation (thermal insulation) of thermal insulation board 22 from thermal insulation board 22 toward the heat of thermal insulation board 22 from tabular thermal source.
At this moment, because thermal insulation board 22 is to be supported on the bottom surface of housing 21 by projection 33, so the contact of thermal insulation board 22 relative housings 21 is in an approximate some state of contact.Therefore, the contact area of thermal insulation board 22 relative housings 21 is also minimum, and the heat that conducts to housing 21 from thermal insulation board 22 is also minimum.
In addition, because thermal insulation board 22 be according to the spacing distance H of tabular thermal source 23
1Greater than with the spacing distance H of itself and housing 21 bottom surfaces
2Mode set.Therefore, in limited space, be radiated to the calorie spread of thermal insulation board 22, and be radiated to the calorie spread of housing 21, can both reduce as far as possible from thermal insulation board 22 from the tabular thermal source 23 of high temperature.At this moment, because on the thermal insulation board 22 coating is arranged, the radiant heat that tabular thermal source 23 sends is reflected by this coating, so the propagation heat from tabular thermal source 23 to thermal insulation board 22 still less.
And, being tilted shape for perverse 30 turns up, when being installed in plane heater 17 on the heating surface 12a, perverse 30 to lodging direction generation strain, because it restores elastic force and tabular thermal source 23 is urged to heating surface 12a, therefore, can remain with suitable plus-pressure tabular thermal source 23 is pressed against state on the heating surface 12a.Therefore, tabular thermal source 23 is improved to the heat conductivity of heating surface 12a, heat transfer efficiency improves.
And, this perverse 30 is to have cut continuously and formed at the roughly whole Width of thermal insulation board 22, so, thermal insulation board 22 intensity enhancing, be attached to the number of the projection 30 on perverse 30, can tabular thermal source 23 be urged to heating surface 12a at perverse 30 whole length direction at least.
On the other hand, because perverse 30 with kink 30b and tabular thermal source 23 butts, the contact site of perverse 30 tabular relatively thermal source 23 is an arc surface.Therefore, different with the situation that only makes the perverse upper end of having been cut and tabular thermal source 23 butts, can not damage the insulating mica plate 26 of tabular thermal source 23 downsides, thin insulating mica 26 (thickness is 0.3-0.5mm) can not take place break, contact the bad phenomenon that electric leakage accident etc. takes place with heating line 24 for perverse 30.
In addition, at the length direction two ends of kink 30b, the perverse 30 cut-out edge of cutting time-out arranged.But, because the tabular relatively thermal source 23 in the length direction both ends of this kink 30b, be to contact at the position of staggering, configuration position with heating line 24, so, even the cutting shoulder at kink 30b length direction both ends has staved the insulating mica plate 26 of the downside of tabular thermal source 23, perverse 30 can not contact with heating line 24 yet.
Fig. 7 to Figure 11 shows the 2nd to the 6th embodiment of the present invention, and the part identical with Fig. 1 put on identical symbol and described in these accompanying drawings.
In the 2nd embodiment shown in Figure 7, on thermal insulation board 35, being formed with alternately makes progress reaches perverse 37 and perverse 36 that turns up downward vertically.This thermal insulation board 35 is supported on the bottom surface of this housing 21 by making the downward perverse 36 bottom surface butt with housing 21, and perverse 37 that makes progress as support projection portion, by this perverse 37 tabular thermal source 23 of supporting.
In the 3rd embodiment shown in Figure 8, on thermal insulation board 38,, its marginal portion forms pin sheet 39 downwards by being bent, and, upwards vertically turn up a plurality of perverse 40 as support projection portion.This thermal insulation board 38 is supported on this housing 21 by making the pin sheet 39 and the bottom surface butt of housing 21, and by the perverse 40 tabular thermal source 23 of supporting.
In the 4th embodiment shown in Figure 9, on thermal insulation board 41, downwards and upwards alternately drawing and forming has the jut 42 and 43 of platform shape.This thermal insulation board 41 is supported on the bottom surface of this housing 21 by making the protruding downwards jut 42 and the bottom surface butt of housing 21, and convex jut 43 as support projection portion, support tabular thermal source 23 by this jut 43.
In the 5th embodiment shown in Figure 10, drawing and forming has the corrugated part 45 as the support projection portion that projects upwards on thermal insulation board 44.In addition, drawing and forming has the jut 46 of upwards outstanding waveform on the bottom surface of housing 21.Like this, thermal insulation board 44 is supported on housing 21 by being placed on the jut 46, and by the tabular thermal source 23 of corrugated part 47 supportings.
In the 6th embodiment shown in Figure 10, on thermal insulation board 47, alternately drawing and forming has protruding and convex corrugated part 48 and 49 downwards.Therefore, these thermal insulation board 47 sections are roughly waveform.This thermal insulation board 47 is supported on this housing 21 by making the protruding downwards corrugated part 48 and the bottom surface butt of housing 21, and convex corrugated part 49 as support projection portion, support tabular thermal source 23 by this corrugated part 49.
Even make the such structure of above-mentioned the 2nd to the 6th embodiment, both contacts area of thermal insulation board 35,38,41,44,47 tabular relatively thermals source 23 and housing 21 are also all very little, thus the same with above-mentioned the 1st embodiment, can obtain the effect that thermal insulation improves.Especially in the 4th embodiment shown in Figure 9, support tabular thermal source 23, so can not damage the insulating mica plate 26 of downside with the plane upper surface of jut 43.
At this moment, in above-mentioned Fig. 7 and the 2nd and the 3rd embodiment shown in Figure 8, also can be bent to form horizontal plate, support tabular thermal source 23 by this horizontal plate perverse 37,40 top ends.
Again, in the various embodiments described above, the plane heater that is applied to be installed on interior case 12 bottom surfaces (heating surface 12a) is illustrated, but the plane heater of case upper side in also can being applied to be installed in.In addition, also can change buttonhole 27 into be fixed on the housing multidiameter, by the end difference supporting thermal insulation board of this multidiameter.
In addition, the present invention is not limited to as mentioned above and the embodiment shown in the figure, for example, is not limited to bake the plane heater in microwave Shanghai, and can be widely used in the plane heater etc. of common heating cooking pot, in the scope that does not break away from its main points, can do allly to implement after changing.
As mentioned above, if adopt the plane heater of heating cooking device of the present invention, because the member of adiabatic usefulness adopts metal thermal insulation board, so it is different during with the heat guard that adopts glass fibre system, resource can be utilized once more, environment is not had harmful effect, and because on metal thermal insulation board, give prominence to the support projection portion that is provided with, support tabular thermal source by this support projection portion, so thermal insulation board diminishes to the contact area of tabular thermal source, the heat output from tabular thermal source to thermal insulation board reduces, consequently, reach housing and the heat of overflowing outside reduces from tabular thermal source through thermal insulation board, though adopt metal thermal insulation board can obtain outstanding thermal insulation.
Plane heater according to heating cooking device of the present invention, the relative housing with tabular thermal source of thermal insulation board can be connected mutually movably, so even thermal coefficient of expansion separately is variant, also can absorb, so, can not produce big thermal stress between above-mentioned 3 and deform or damaged.
Plane heater according to heating cooking device of the present invention, perverse of being turned up by heeling condition of the support projection portion of thermal insulation board constitutes, this perverse because of tabular thermal source and heating surface butt to lodging direction strain, restore elastic force by it tabular thermal source is urged to heating surface, so, tabular thermal source is pressed against on the heating surface by the plus-pressure of appropriateness all the time, can transmit heat to heating surface well.
Plane heater according to heating cooking device of the present invention, because being the roughly whole Width at thermal insulation board, perverse of constituting support projection portion form, so, even the thermal insulation board thinner thickness, the intensity of thermal insulation board also can improve, and tabular thermal source can be pressed against on the heating surface well.
According to the plane heater of heating cooking device of the present invention, bent because constitute perverse top ends of support projection portion, the bend of its bending and tabular thermal source butt be not so tabular thermal source can be damaged because of perverse.
According to the plane heater of heating cooking device of the present invention, because the coating of light reflection usefulness is arranged on the thermal insulation board, so thermal insulation board has further improved thermal insulation because of the heat that the radiation of tabular thermal source is subjected to is few.
Plane heater according to heating cooking device of the present invention, because the size of space of tabular thermal source and thermal insulation board is set at the size of space greater than housing bottom surface and thermal insulation board, so, can be with the heat of the limited radiation propagation of space minimizing from tabular thermal source to thermal insulation board.
Plane heater according to heating cooking device of the present invention, because the length direction both ends of support projection portion butt with it on the position of staggering with heating line configuration position of tabular thermal source, so, even there is the sword limit at the length direction both ends of support projection portion, tabular thermal source has been damaged on this sword limit, support projection portion can the contact heating line yet, the electric leakage accident can not take place.