CN1299053C - Heating device of lower portion of microwave oven - Google Patents

Abstract

The present invention discloses a lower heating device for a microwave oven, which can improve heat efficiency. The lower heating device is composed of a lower heater, a reflecting plate and a matching hole, wherein the lower heater can generate light waves and can not generate superheating phenomenon because of the characteristics of the lower heater; the reflecting plate which is combined with a cavity has a structure which can reflect the light waves generated by the lower heater into the cavity; the matching hole for preventing microwaves from leaking and the lower heater from transferring heat is arranged in one side of the cavity corresponding to the reflecting plate and is provided with a plurality of through holes. The lower heating device can reduce the heat loss of the lower heater, shorten cooking time, and accordingly save electric energy. In addition, because the present invention has simple structure, product cost can be reduced.

Description

Heating device of lower portion of microwave oven

Technical field

The present invention relates to a kind of heating device of lower portion of microwave oven, particularly relate to a kind of heating device of lower portion of microwave oven that improves the thermal efficiency and reduce cost.

Background technology

Micro-wave oven is a kind ofly to utilize electricity to produce microwave and make microwave by being heated by the device for cooking of cooking food to cause the molecule vigorous exercise in the food by cooking food.Traditional micro-wave oven only utilizes heating using microwave merely, and its mode of heating is more single, and its heat output also is restricted, and therefore the cooking of quick and high-quality can't be provided.When utilizing this micro-wave oven to heat,, it can evenly heat by the advantage of cooking food inside and outside though having, because by the cooking food difference, thereby also different to the requirement of heating, this advantage becomes shortcoming possibly.The light wave of developing with lamp in order to overcome this shortcoming is the micro-wave oven of heating source, be that its utilization can produce 90% lamp with the following wavelength light wave of 1 μ m and is heating source, utilize lamp visible light emitted and infrared ray, under keeping, heat by cooking food fully by the condition of cooking food surface and bulk properties.Fig. 1 illustrates the micro-wave oven that heater is installed.But the microwave that this micro-wave oven has a heat effect by the cavity 1 of heated food with for generation is equipped with the electric apparatus room 3 of various accessories to be formed.Cavity 1 downside is provided with the netted coupling hole 4 with a plurality of through holes.The machine works that causes for fear of microwave is unusual, and the diameter through hole littler than microwave wavelength used in coupling hole 4, and the diameter of through hole is about 3～5mm.It is heater 13 that the downside in coupling hole 4 is provided with the heating source that available light wave comes heat food, and it utilizes coupling hole 4 that radiant heat is delivered in the cavity 1.The downside of heater 13 is provided with reflecting plate 10, and it can reflex to the light wave that heater 13 sends downwards in the cavity 1 of its upside.In order to improve reflectivity, common reflecting plate 10 enterprising electroplatings in lead system.The two ends of reflecting plate 10 are provided with a plurality of passage 10a, and the air by passage 10a can cool off heater 13.The heat release of heater 13 be for the temperature maintenance that makes itself below 850 ℃, so just can not influence operate as normal.If heat release not exclusively can make the quartz ampoule of heater 13 overheated and dissolve, thereby cause its inner gases at high pressure to be revealed and make the quartz ampoule projection.And the reflecting plate 10 of aluminum also can produce distortion because of heat resisting temperature is low.Reflecting plate 10 right sides are provided with cooling fan 15 from air to the passage 10a of reflecting plate 10 that can send into.Cooling fan 15 is arranged on cooling fan support 15b upward so that the left direction of air in Fig. 1 that produces is mobile.Reflecting plate 10 on the heater 13 is arranged in the air duct 17, and the right side of air duct 17 links to each other with cooling fan support 15b, and the left side then combines with air guiding device 18.It is the air stream that is produced by cooling fan 15 in order to guide that cooling fan support 15b, air duct 17 and air guiding device 18 are set.The filter glass 5 of coupling hole 4 upside settings can transmit the radiant heat that is sent by heater 13 in cavity 1, and can stop the lower air of temperature that feeds for cooling heater 13 to flow in the cavity 1.And, when high temperature common glass contacts with cryogen and ceramic component has been added in the glass explosion that causes when making tempered glass.And impurity flow in the heater 13 when utilizing filter glass 5 also can prevent the issuable spark of coil of the heater 13 that caused by microwave and the cooking.The extraneous air that is sucked by cooling fan 15 can flow to air duct 17 directions by the through hole that cooling fan support 15b one side is offered, and flow into passage 10a cooling settings the heater 13 on reflecting plate 10 of air by reflecting plate 10 1 sides in the air duct 17, the passage of being offered by reflecting plate 10 opposite sides is discharged again, and the preceding outlet of offering by not shown micro-wave oven lower end along the air guiding device 18 that links to each other with air duct 17 at last is discharged to the outside.Meanwhile, behind the connection power supply, the radiation that produces on the heater 13 flow into heat food in the cavity 1 by coupling hole 4 and filter glass 5.But there is following shortcoming in traditional heating device of lower portion of microwave oven, can together cool off ambient air when promptly the air stream that is produced by cooling fan 15 cools off heater, air themperature is discharged to the outside after raising, therefore, quite a few heat that produces on heater 13 can be lost to outside the cavity, not only can loses heat, and can make the time of the cooking elongated.And, need to be provided with the cooling fan 15 that can suck and send extraneous air, cooling fan support 15b and air duct 17 and the air guiding device 18 that forms air flow passage for the heat release of heater 13, can increase product cost like this.

Summary of the invention

In order to address the above problem, the object of the present invention is to provide a kind of thermal efficiency that improves lower heater also can make the heating device of lower portion of microwave oven that simplify the structure relevant with lower heater.

In order to achieve the above object, heating device of lower portion of microwave oven of the present invention is by lower heater; Be arranged on lower heater below, have the light wave that lower heater can be produced and reflex to structure in the cavity and the reflecting plate that combines with cavity; And be arranged on corresponding cavity one side of reflecting plate and for preventing microwave loss and the heat that lower heater produces being sent to the coupling hole composition that is provided with in the cavity with a plurality of through holes; Described lower heater is by can producing light wave and by self characteristics decision superheating phenomenon not take place, and a plurality of ceramic heaters compositions of connect with power supply.

Use heating device of lower portion of microwave oven of the present invention can make heating device of lower portion need not the moving air cooling, thereby can reduce heat loss, and when the cooking, can shorten the cooking time, and then can save electric energy.And,, not only reduced cost so accessories such as cooling fan, cooling fan support, air duct and air guiding device can be installed owing to need not to cool off heating device of lower portion, and because assembling is simple, thereby can boost productivity.

Description of drawings

Below in conjunction with the drawings and specific embodiments heating device of lower portion of microwave oven of the present invention is elaborated.

Fig. 1 is traditional heating device of lower portion of microwave oven mounting structure exploded perspective view.

Fig. 2 is a heating device of lower portion of microwave oven mounting structure exploded perspective view of the present invention.

Fig. 3 is a heating device of lower portion of microwave oven installment state profile of the present invention.

The specific embodiment

As Fig. 2, shown in Figure 3, but micro-wave oven is made up of with the electric apparatus room 30 of accessories such as magnetron that not shown produced microwave is housed and high-tension transformer the cavity 20 of heat food.Be provided with below the cavity 20 and can prevent from microwave loss and will be installed in heat that the heater of its underpart produces to be sent to coupling hole 40 in the cavity 20 with a plurality of through holes.Coupling hole 40 is identical with the coupling hole 4 in the prior art micro-wave oven.The upside in coupling hole 40 is provided with filter glass 45, and it can prevent that impurity such as food from flowing into the bottom by coupling hole 40, and has added ceramic component when making tempered glass, can prevent that like this microwave from passing through.The downside in coupling hole 40 is provided with ceramic heater 60, and it utilizes ultrared radiant heat to heat and radiant heat is delivered in the cavity 20 by coupling hole 40.Be arranged on below the ceramic heater 60, and reflecting plates 50 that the downward light that ceramic heater 60 sends is reflexed in its upside cavity 20 have adopted more in the past than the stainless steel that price was lower, hear resistance is higher, also can adopt reflectivity height, good heat resistance, other material that cost is lower to make reflecting plate 50.After ceramic heater 60 is connected power supply, can produce infrared ray on it, and radiation can upwards be concentrated infrared ray by reflecting plate 50, flow in the cavity 20 with the filter glass 45 that is arranged on coupling hole 40 upsides by the netted open-end hole on the coupling hole 40 and come heat food.Meanwhile, the microwave that is produced by magnetron in the electric apparatus room can not be leaked to downside owing to added the cause in the filter glass 45 of ceramic component and the coupling hole 40 that is provided with the diameter through hole littler than microwave wavelength.Can will connect power supply again after two ceramic heater 60 parallel connections, and to the number of ceramic heater 60 without limits.In general the capacity of microwave oven cavity 20 is fixed, and in less cavity 20 bottoms of capacity heater is installed if desired, then needs the volume small heaters.In order to improve the thermal efficiency, a plurality of ceramic heaters 60 can be connected in parallel.And, can heat up rapidly after ceramic heater 60 energising, be warmed up to behind the proper temperature because therefore the constant temperature characteristic of himself and superheating phenomenon can not take place need not to establish in addition cooling system.And its relative heater 13 prices are low, therefore can save producing cost.In addition, because the coil resistance of heater 13 is smaller, therefore, the energising back fluorescent lamp scintillation that the meeting generation is caused by excessive conducting electric current in heater 13, for preventing that this phenomenon from occurring, heater 13 is equipped with delayer and prolongs initial actuation time, but because the coil resistance of ceramic heater 60 is bigger, therefore this phenomenon can not take place on the ceramic heater of energising back, so need not to establish in addition delayer.And the IR wavelength that ceramic heater 60 produces is longer, so it can be penetrated into the inside of heated object, and utilizes radiant heat, even this heater table surface temperature is lower than other heater, but the surface temperature of heating object also can be very high.And, because heating device of lower portion of microwave oven of the present invention need not heat release, so can not use the accessory relevant with heat release, promptly do not use cooling fan support 15b, cooling fan 15, air duct 17 and air guiding device 18, so not only can reduce cost, and assembling is simple, therefore can boost productivity and competitiveness of product.Because the heater assembly of bottom is made of 2 ceramic heaters 60, its heating area was than increased in the past, and therefore heating evenly.In order to prevent that microwave is leaked to cavity 20 outsides, coupling hole 40 offers the diameter a plurality of through holes shorter than microwave wavelength.But coupling hole 40 to cavity 20 inside, can't cause the lower heater operation irregularity with microwave reflection, and therefore mating hole 40 can be arranged to simple through hole.And the radiant heat that the increase lower heater flow in the cavity 20 can improve the thermal efficiency.

Claims (1)

1, a kind of heating device of lower portion of microwave oven, it is by lower heater; Be arranged on lower heater below, have the light wave that lower heater can be produced and reflex to structure in the cavity (20) and the reflecting plate (50) that combines with cavity (20); And be arranged on and corresponding cavity (20) one sides of reflecting plate (50) and for preventing microwave loss and the heat that lower heater produces being sent to coupling hole (40) composition that is provided with in the cavity (20) with a plurality of through holes; It is characterized in that: described lower heater is by can producing light wave and by self characteristics decision superheating phenomenon not take place, and a plurality of ceramic heaters (60) of connect with power supply composition.

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