JPS6261851B2 - - Google Patents

Description

[Detailed description of the invention] The present invention equips an electric oven with a humidity sensor,
The purpose is to detect moisture released from food during cooking as relative humidity without error.

Conventionally, cooking in electric ovens has been done by manually setting the time using a timer and manually setting the temperature using a temperature control volume. For this reason, there are errors due to settings, and the final determination of when cooking is complete depends on the user's intuition, so optimal cooking is rarely achieved. In recent years, it has been discovered that the moisture released from the food being cooked is closely related to the progress of cooking, and microwave ovens are already using humidity sensors to detect moisture, and some even automatically determine when cooking is complete. It's on the market. However, since the internal temperature of electric ovens is high, it is difficult to detect relative humidity using a method similar to that used for microwave ovens. To detect relative humidity with a humidity sensor,
Since the amount of water released from food is limited, at least
It is necessary to lower the temperature of the exhaust air from the electric oven to below 70°C and install a humidity sensor at that location to detect humidity. This problem can be solved by installing the exhaust duct of the electric oven downwards, which lowers the temperature of the exhaust air inside the duct, but the setting of the exhaust air volume is very delicate, and the air is taken in from between the front door and the exhaust air. With natural convection, if there is wind outside the electric oven, the temperature of the exhaust air inside the exhaust duct will fluctuate, so when detecting relative humidity with a humidity sensor installed inside the exhaust duct, the detection level will fluctuate greatly, leading to errors. It became so large that accurate humidity detection was not possible. Furthermore, after cooking food that contains a large amount of water, the water that comes out as steam from the food cools down in the exhaust duct and condenses near the humidity sensor. This resulted in an error in humidity detection, making accurate humidity detection difficult.

The present invention forcibly sends air into the electric oven, provides a backflow prevention plate in the exhaust duct, and
This eliminates point errors, that is, humidity detection errors due to external wind and humidity detection errors due to residual moisture after cooking high-moisture foods, and makes humidity detection more accurate.

An embodiment of the present invention will be described below based on the drawings. FIG. 1 is a sectional view of the electric oven viewed from the side. The housing 1 and the front door 2 are sealed with a packing material 3 during cooking. When food 8 on a cooking plate 7 inside the refrigerator is heated by an upper heater 5 and a lower heater 6 attached to the inner wall 4 of the housing 1, steam 9 is generated. This steam 9 is carried by the wind and sent to an exhaust duct 11 whose one end is an opening at a notch 10 provided in a part of the upper rear end of the inner wall 4. The exhaust duct 11 hangs down along the outer wall 12 of the housing 1, in which air is cooled, and the relative humidity of the steam 9 is detected by a humidity sensor 13 provided inside. The lower part of the humidity sensor 13 is approximately the cross-sectional area of the exhaust duct 11.
Three backflow prevention plates 14, which occupy two-thirds of the space, are arranged horizontally or downwardly, and the exhaust air passes through these plates and exits from the exhaust duct 11. The steam 9 detected as relative humidity by the humidity sensor 13 is further cooled in the exhaust duct 11 and partially condenses near the backflow prevention plate 14 . The degree of condensation is almost determined by the amount of moisture contained in the food 8. A dew pan 15 provided at the bottom of the exhaust duct 11 is for receiving condensed water droplets together with the oil contained therein. Further, the backflow prevention plate 14 is used to prevent wind from flowing back into the electric oven from the outside so that it does not directly reach the humidity sensor 13, and the shape shown in FIG. 2 is considered. It will be done.
That is, a is provided horizontally, b is provided tilted downward, and c is provided with the tip bent downward. The condensed moisture 16 flows out more easily from points b and c than from point a.

FIG. 3 is a partial cross-sectional view of the electric oven viewed from above, in which a blowing duct 21 is provided, one end of which is a notch 20 provided in a part of the front end of the side surface of the inner wall 4 of the housing 1. Air is blown into the refrigerator by a fan 22. When the airflow rate switching valve 23 is open, the airflow rate into the refrigerator is weak and small. At this time, some of the air is sent forward to cool the control circuit (not shown). The time when the amount of air blown into the refrigerator is small is during cooking, and the time is when humidity is detected. On the other hand, as shown in FIG. 4, when the strength switching valve 23 is closed, the amount of air blown into the refrigerator is strong and large. At this time, the air blowing to the control circuit stops, but since the amount of air being blown into the refrigerator is large, the amount of air passing through the exhaust duct 11 also increases, and when the temperature inside the refrigerator is high, the remaining moisture in the exhaust duct 11 is quickly removed downward. The exhaust duct 11 can be cleaned by blowing toward the outlet. Further, in this case, in the structure of the backflow prevention plate 14 shown in FIG. 2, the moisture can be blown off in a shorter time in the configurations b and c than in the configuration a.

As described above, according to the present invention, the backflow prevention plate in the exhaust duct can make it less susceptible to wind disturbance from the rear, and the moisture coming out of the food to be cooked during cooking can be detected more accurately as relative humidity without error. be able to. Furthermore, by tilting the backflow prevention plate, it becomes easier to blow away residual water. Furthermore, since it uses a forced air blowing mechanism using a fan, it is less susceptible to disturbances caused by wind from the front, and by switching the forced air blowing mechanism using a fan in two stages, it is possible to blow away residual moisture in the exhaust duct with a strong force.

In addition, experiments have shown that the temperature rise stabilization time near the humidity sensor is longer than the stabilization time when the internal temperature rises. Although a longer preheating time is required, by blowing strong air for a short time when the temperature inside the refrigerator overshoots even with forced air blowing by a fan, the humidity can be reduced in approximately the same time as the temperature inside the refrigerator rises and stabilizes. It has been confirmed that the temperature near the sensor can also be stabilized.

[Brief explanation of the drawing]

Fig. 1 is a side cross section showing one embodiment of the present invention, Figs. 2 a to c are three configuration diagrams of the exhaust duct, Fig. 3 is a top partial sectional view, and Fig. 4 explains the operation of the ventilation mechanism. FIG. 1... Housing, 4... Inner wall, 5, 6... Upper and lower heaters, 10... Notch, 11... Exhaust duct, 13
... Humidity sensor, 14 ... Backflow prevention plate, 15 ...
Dew pan, 20...notch, 21...blow duct, 22...fan, 23...strong/weak switching valve.

Claims (1)

[Scope of Claims] 1. A fan is provided for blowing air into the refrigerator through a blow duct whose opening is a notch provided in a part of the side surface of the inner wall of the refrigerator, and a fan is provided at one end of the rear surface of the inner wall of the refrigerator. The provided notch is an opening at one end, and the opening at the other end is provided downward at a position hanging down along the outer wall of the oven, and a humidity sensor is installed in the exhaust duct. An electric oven characterized in that a backflow prevention plate is provided in the exhaust duct further down, and a condensation catcher is provided below the opening at the other end of the exhaust duct. 2. The electric oven according to claim 1, characterized in that the amount of air blown into the oven by the fan is switched in two or more stages. 3. The electric oven according to claim 1 or 2, wherein the backflow prevention plate is inclined downward at the tip.