1. Field of the Invention
The present invention is related to a high frequency heating apparatus equipped with a high frequency heating cooking apparatus and a ventilating apparatus of a cooker provided under a main body of the high frequency heating apparatus. The present invention is also related to a high frequency heat-cooking apparatus equipped with an oven hood, which owns a ventilation fan capable of sucking gas generated from another heating/cooking apparatus to exhaust the generated gas. Furthermore, the present invention is related to a high frequency heating apparatus equipped with an oven hood fan, which heats an article to be heated. More specifically, the present invention is directed to a method of cooling a high frequency electric power supplying apparatus capable of protecting a heating member from over heat destruction even when the high frequency electric power supplying apparatus is operated under ambient temperature environment.
2. Description of the Related Art
Conventionally, as this sort of high frequency heating apparatus, for instance, the following high frequency heating system has been proposed. That is, as indicated in FIG. 6, a magnetron 9 is arranged on the right side of a heating chamber, high-frequency electromagnetic waves (microwave power) are conducted by using a wave-guide 10 to an upper portion of the heating chamber 8, and then the high-frequency electromagnetic waves are supplied from this upper portion of the heating chamber 8 by stirring the electromagnetic waves by a rotated stirrer 11.
Also, as this sort of high frequency heat-cooking apparatus equipped with an oven hood, for instance, Japanese Laid-open Patent Application No.Hei-11-166732 discloses such a high frequency heat-cooking apparatus equipped with an oven hood. FIG. 4 schematically indicates the conventional high frequency heat-cooking apparatus described in the above-explained application. In FIG. 10, reference numeral 101 indicates a main body of an appliance, reference numeral 103 shows another heat-cooking apparatus, and reference numeral 105 indicates a heating chamber. Also, reference number 106 represents a high frequency generating apparatus, reference numerals 109a and 109b indicate air intake ports, reference numeral 110 shows a ventilation fan, reference numeral 111 denotes an exhaust port, and reference numeral 115 is a cooking article.
Furthermore, conventionally, as a microwave oven equipped with an oven hood fan and a heat-cooking apparatus at a lower portion thereof, a cooling apparatus having a strong cooling capability and also capable of producing a large amount of wind must be provided with this microwave oven in order to avoid that an electric power supplying apparatus is destroyed due to an overheat phenomenon caused by, for example, heat generated from the lower-installed heat-cooking apparatus. On the other hand, since the cooling apparatus having such a strong cooling capability produces large noise, such a noisy cooling apparatus is not matched with the recent market needs (namely, silent cooking places are required). Also, since the cooling apparatus having such a strong cooling capability consumes very high electric power, generally speaking, a ratio of high frequency output power to total power consumption of an electric appliance is necessarily reduced.
In the above-described arrangement of the conventional high frequency heating apparatus, while an opening of the high frequency heating apparatus is arranged at the upper portion of the heating chamber, the high frequency electromagnetic waves are stirred by using the stirrer located in the vicinity of this opening. As a result, superior uniformities as to heating operation can be realized in the case that large-sized food products which stick out from a turn table (turn table is not rotated) is heated by the stirred high frequency electromagnetic waves. However, since the long wave-guide is employed, transmission loss of the high frequency electromagnetic waves may occur, so that the heating efficiency is low and also the microwave power is low. Further, since another cooling fan (not shown) used to cool the magnetron is required, there is another problem that the dimension of the machine chamber is increased and the dimension of the heating chamber is decreased. In addition, since the long wave-guide is equipped with the conventional high frequency heating apparatus, the cost thereof is increased.
Moreover, in the above-described conventional high frequency heat-cooking apparatus, there are many cases that the ventilation fan 110 is actuated in order that gas generated while another heat-cooking apparatus 103 installed under the main body 101 of the appliance is used is not filled within a kitchen. Then, when the ventilation fan 110 is actuated, in such an emergency case that the cooking article 115 fires which contains a large amount of oil components and is being heated by the other heat-cooking apparatus 103, the flames are furthermore blown by the ventilation fan 110. There are such problems that the appliance main body 101 is destroyed, and/or the fired appliance main body 101 spreads to other articles.
Also, when food products are heated by the high frequency heat-cooking apparatus equipped with the oven hood, a cooling fan (not shown) for cooling the high frequency generating apparatus 106 is operated. Even when the ventilation fan 110 is not actuated, there is another problem that flames are sucked by air suction of the cooling fan.
Also, in the case that the cooking article 115 which is being heated by the other heat-cooking apparatus 103 will fire, even when the food product is heat-cooked by the high frequency heat-cooking apparatus equipped with the oven hood, a stop button provided on an operation panel of the appliance main body 101 is manipulated so as to stop cooking of the hood products, or the ventilating operation of the ventilation fan 110 must be stopped even if the ventilation fan 110 is actuated. However, while the flames appear, there are other problems that a dangerous situation happens to occur, and therefore, any persons cannot approach the appliance main body 101.
Furthermore, the above-described conventional high frequency heating apparatus owns the following problem, since such an oven having a self-cleaning function is marketed in which high output power of a lower-installed heat-cooking apparatus operated by gas or electric power is gradually required due to market needs, and temperatures within chambers are reached to 400° C. to 500° C. In connection therewith, the thermal adverse influences given to the high frequency heating apparatus equipped with the oven hood fan are also increased. As a fact that the cooling atmospheric temperature is increased, the cooling effect with respect to the electric power supplying apparatus is deteriorated, so that the destruction of this electric power supplying apparatus easily occurs due to such an overheat phenomenon.
While the cooling apparatus having the strong cooling capability is provided in order to satisfy the cooling performance even under sever conditions, when this cooling apparatus is operated, wind-cutting sounds which are produced from propellers of the cooling fans and the cooling wind are not matched with the recent customer's needs (namely, silent cooking places are needed). Also, since this powerful cooling apparatus consumes high electric power, there are other problems. That is, a ratio of high frequency heating power to a total electric power consumption value of an electronic appliance cannot be increased which is limited due to the law regulation, or the circuit breaker capacity of home electronic appliances. Therefore, increasing of the high frequency heating output power required to speed up cooking time is impeded.