DE7915661U1 - MICROWAVE OVEN - Google Patents

Description

Title: Microwave Oven

With known microwave oven is to get the desired Achieve heating results through dielectric heating and radiant heating (electrical or Gas heating) a microwave generator is arranged below the furnace muffle, taking into account the temperature spread. With such an arrangement, the microwave energy is introduced into the furnace muffle from below is to be, only a relatively short waveguide "is necessary. However, with such an arrangement Microwave energy is reflected or partially adsorbed by the container holding the objects to be heated contains or the suspensions by which the container or the material to be heated is held, so that the efficiency of microwave heating is adversely affected. If with an aforementioned arrangement the microwave energy is transmitted into the furnace muffle from above, the use of a proportionate long microwave conductor from the microwave gene

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rator, which is arranged below, necessary with the result that the losses of output energy in the Microwave conductor grows with success that the dielectric heater efficiency deteriorates.

Furthermore, such a structure is relatively complicated, so that the manufacturing cost of the furnace increases.

On the other hand, if the microwave generator is placed in the furnace muffle, the efficiency becomes the dielectric Heating satisfactory, but because the heat generated by the radiant heating is directly too is transmitted to the microwave generator, a fan having a relatively large capacity must be provided to guarantee sufficient cooling of the microwave generator, which in turn reduces production costs elevated. In addition, since a significant part of the heat is dissipated from the furnace muffle, the efficiency of the radiant heating is reduced.

The object of the invention is to eliminate these disadvantages and to provide a microwave oven in which A high degree of efficiency of both types of heating can be maintained when placed on the furnace muffle Microwave generator.

This object is achieved in a microwave oven with the features of patent claim.

According to the invention, there is therefore a space between them the furnace muffle and the waveguide are provided, to ensure that the heat in the furnace muffle cannot be freely transferred to the microwave generator and there is also a microwave shield such as a flap or a damping coil

provided in the clear room in order to avoid local energy losses.

According to the invention, regardless of the structure of the furnace

regarding other features, the microwave energy introduced into the furnace muffle from above and the microwave generator is arranged above the furnace muffle without causing thermal problems. With others In words, the length of the microwave line can be kept shorter and hence the loss of high frequency energy be reduced. Conversely, this increases the efficiency of the dielectric heating system. In addition, the furnace is simpler in its construction and therefore also less expensive. Additionally also, since it is no longer necessary to install a large capacity blower, the efficiency of the Radiant heating is not affected and the overall cost of the furnace is reduced.

Further features and advantages are explained below with reference to the accompanying drawing, which in Detail one embodiment of the principle of the invention on a household microwave oven.

In the drawing, 1 denotes a microwave generator which contains, for example, a magnetron can. The microwave generator is arranged above the furnace muffle (heating chamber) 2, with a . Microwave conductor 3 is arranged so that the microwave energy from the microwave generator 1 in the Oven muffle 2 is transferred. In this way, the furnace muffle 2 receives the output from the microwave generator 1 Energy via the microwave line 3 from above. Between the furnace muffle 2 and the waveguide a clear space 4 is provided in which a thermal insulation 5 extends over the entire outer Wall of the furnace muffle 2 extends. In the space 4 is a seal 6 to prevent

Microwave losses, i.e., a flap or attenuation channel adjacent to the exit end of the waveguide 3 arranged. This sealing closure 6 can also be adjacent to the microwave inlet in the oven

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til

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; 1 muffle 2 can be arranged in the upper muffle wall.

Opposite this microwave entrance in the upper wall of the furnace muffle 2, where the microwaves are transmitted from the waveguide 3 to the furnace muffle 2 is an end plate 7 made of a dielectric material

provided with low dielectric losses, wel-

'before the internal heat escapes from the furnace muffle

γ 2 and the effect on the microwave generator

I change.

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$ Inside the furnace muffle 2 is a heating element 8 for

I provided radiant heating. The open front

I the furnace muffle 2 is closed by a flap 11-

I | sen, which is pivotable on hinge brackets 10 on the

% 15 housing or the outer wall 9 are fastened in such a way that

'ξ that free access and locking of the furnace

fe muffle is possible. A control panel 12 is in the upper

: Area of the housing 9 is provided.

h 20 With such an arrangement of the functional elements

I allows the combined use of the dielectric

1 heating by the microwave generator 1 and the beam

I treatment heating through the heating member 8 heating a

β (not shown) food, which in this case

ψ represents 25 d _as heating object by simultaneously, inner

ε; ' Heating and enameling and with it the delivery

.% of the desired cooked food in a short time.

e | Although the temperature inside the heating muffle is one

i) can assume a very high value, the oversight of a

H Qf)

fi space 4 between the furnace muffle 2 and the

! ' Waveguide 3 and the arrangement of a thermal

$ Insulation in this gap 4 only leads to a slight

|| gene transfer of heat from the furnace muffle 2 to the

Fl microwave generator 1.

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Thereby, even if the dielectric heating and the radiant heating are used at the same time, the microwave generator 1 is not too thermal

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affects and, although the microwave generator 1 above the oven racket is arranged, it is no longer necessary to provide a high capacity blower. The loss of microwave energy is thus reduced, because a short waveguide is sufficient to transmit the microwaves. In addition, the provision closes of the microwave sealing members 6 within the distance 4 from microwave losses.

From the foregoing description, it will be apparent that the application of the present invention may include the following and other desirable outcomes.

(1) Since the heat inside the furnace muffle is not transferred to the microwave generator, dielectric Heating and radiant heating can be applied at the same time.

(2) Since the microwave generator is placed in the furnace muffle, the length of the microwave guide can be reduced and consequently the loss of microwaves in the microwave guide is minimized will.

(3) Since less heat escapes from the furnace muffle can, the degree of heat build-up within the furnace muffle is large enough to cause a considerable Reduction in the heat capacity of the heating elements

to enable.
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Claims (1)

rt r f tr BOSCH-SIEMENS HAUSGERÄTE GMBH 8 Munich 80, May 30, 1979 Stuttgart Hochstrasse 17 TZP 79/802 Kes / si Title: Microwave Oven CLAIM Microwave heater (microwave oven), consisting of a furnace muffle for heating one housed in it Good thing, a microwave generator to generate the microwave energy that goes to the furnace muffle is transmitted, a waveguide for transmitting the microwave energy into the furnace muffle from above, wherein the microwave guide with one of its ends with the microwave generator and with its other end with the furnace muffle is connected, further consisting of heating elements for heating the material to be heated by radiant heat, characterized in that a free space (4) between the furnace muffle (2) and the waveguide (3) is formed and further a microwave shield is arranged at the entry end of the waveguide in the Furnace muffle.