JPH0225104B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a so-called hot air circulation type oven in which the temperature inside a heating chamber is raised by an electric heater and a circulation fan.

Conventional configuration and its problems Conventionally, this type of hot air circulation type oven has the advantage of being easy to clean as there is no need to install an electric heater etc. in the heating chamber, and it is possible to cook by storing objects to be heated in the heating chamber one above the other. It has the feature of being able to cook a large amount of food at once. However, for the latter multi-stage cooking, in order to equalize the vertical distribution, from the design stage to mass production, painstaking efforts were made to determine the position and shape of the air outlet and suction inlet, the position of the partition plate for blowing hot air into the heating chamber, etc.
Currently, the optimum point is found by changing the shape, etc.

When cooking with hot air, the areas that are exposed to the heat can be heated well and the food can also be browned, so the strength of the hot air can cause uneven cooking. Furthermore, if the temperature within the heating chamber is not kept constant, the unevenness of cooking becomes even more severe, and sufficient heating cannot be achieved, so accurate temperature control within the heating chamber is required.

Therefore, conventionally a temperature sensor was installed inside the heating chamber.
The temperature of the heating chamber was controlled to a constant temperature. However, installing a temperature sensor inside the heating chamber means protruding into the heating chamber, which not only makes cleaning difficult, but also causes temperature variations due to the influence of hot air depending on the installation position, and In such cases, there are drawbacks such as the need to install a cover to protect the temperature sensor from high frequency waves.

In addition, for models with a temperature sensor installed inside the electric heater mounting box, the distance between the electric heater and the temperature sensor is close, so the sensor detects the heat of the heater and turns off the heater power before the heating chamber reaches the set temperature. This results in temperature control being performed with a large temperature difference between the heating chamber and the electric heater mounting box. Therefore, it was extremely difficult to accurately control the temperature inside the heating chamber.

Purpose of the Invention The present invention solves the above-mentioned drawbacks of the conventional technology, and enables accurate control of the inside of the heating chamber by reducing the thermal gradient of the temperature sensor section in the heating chamber and the electric heater mounting box and performing stable temperature control. The purpose of the present invention is to provide a heating device that can perform oven cooking uniformly and with little unevenness.

Structure of the Invention In order to achieve the above object, the present invention includes a heating chamber for storing an object to be heated in a main body, an electric heater mounting box provided adjacent to a side wall or a back wall of the heating chamber,
A circulation fan and an electric heater for circulating hot air to and from the heating chamber in the electric heater mounting box, a partition plate for blowing hot air into the heating chamber, and a temperature sensor for detecting the temperature inside the electric heater mounting box. and the electric heater is approximately M-shaped, and the electric heater is approximately M-shaped.
A circulation fan is placed approximately in the center of the shape, a temperature sensor is mounted above the circulation fan, and a partition plate is provided close to the wall of the electric heater mounting box and the wall of the heating chamber on the upstream side near the temperature sensor. It is.

In this configuration, when the circulation fan rotates, the air inside the heating chamber and the electric heater mounting box circulates, raising the temperature inside the heating chamber. When the circulation fan rotates, the air in the heating chamber is sucked into the center of the circulation fan, and is blown onto the roughly M-shaped electric heaters placed around the circulation fan, turning it into hot air that flows further around, but does not touch the walls or the surrounding area. If there is a partition plate, it will change direction and blow out into the heating chamber. Therefore, there is a large temperature difference between the temperature of the air sucked into the center of the circulation fan and the temperature of the air that hits the partition plate and blows out into the heating chamber, but the temperature in the center of the heating chamber, which determines temperature control, is higher than that of the circulation fan. The temperature detected by the temperature sensor is almost the same as the temperature at the center of the heating chamber because it flows to the temperature sensor installed above the circulation fan. Therefore, the inside of the heating chamber can be accurately controlled using the temperature sensor, and stable oven cooking can be performed.

DESCRIPTION OF EMBODIMENTS Hereinafter, one embodiment of the present invention will be described based on the drawings.

Inside the main compartment 1 is a heating chamber 2 for cooking food. A door 3 is attached to the front opening of the heating chamber 2 so as to be openable and closable. 4 is used when performing high frequency heating with a magnetron. When performing high-frequency heating, the magnetron 4 is cooled by a cooling fan motor 5, and the cooled air enters the heating chamber 2 through an air guide 6 and is then discharged to the outside through an exhaust guide 7.

A rotary mounting table 8 is attached to the bottom wall of the heating chamber 2, and an oven tray 9 on which the object to be heated is placed is placed. To briefly explain the driving method of the rotary mounting table, 10 is a motor that rotates a circulation fan 11, which drives a pulley B15 attached to a worm gear 14 via a pulley A12 and a belt A13.
The rotary mounting table 8 is driven from another pulley C16 attached to the worm gear 14 via a belt B17.

Next, on the rear wall outside the heating chamber, there is an electric heater mounting box 18.
A substantially M-shaped electric heater 19 for increasing the temperature inside the heating chamber 2 is mounted in the electric heater mounting box 18 by insulators 20 and 21. Further, a fan 11 for circulating air within the heating chamber 2 and the electric heater mounting box 18 is mounted approximately at the center of the electric heater 19. A suction port 22 corresponding to the center of the fan 11 is provided on the rear wall of the heating chamber, and air outlets 23 are provided on the left and right sides, so that when the fan 11 rotates, air circulates as shown by the arrows in FIG. That is, the air in the heating chamber 2 enters the electric heater mounting box 18 through the suction port 22, and the air that enters the heater mounting box 18 is heated by the heater 19 and becomes hot air through the partition plate installed inside the electric heater mounting box 18. 24 and is blown out from the air outlet 23 into the heating chamber 2, and the object to be heated 25 placed on the oven tray 9 rotating within the heating chamber 2 is heated and cooked.

26 is a temperature sensor which controls the power input to the heater 19 when the ambient temperature exceeds a certain level.
The temperature inside the heating chamber is kept constant.

Next, the flow of air inside the electric heater mounting box 18 will be explained with reference to FIG. Circulation fan 11 as shown in the figure
It is a so-called turbo fan that takes in air from the center and exhausts it to the surrounding area. When the circulation fan 11 rotates clockwise, air is sucked in from the center of the fan 11, and is blown out radially around the fan while rotating clockwise under the rotational force of the fan. Then, it is heated by the heater 19, becomes hot air, hits the partition plate 24, and is blown into the heating chamber 2. The hot air raises the temperature inside the heating chamber. At this time, the left side of the partition plate 24, that is, the heater 19 side, is hit by the air heated by the heater 19, so the temperature blown into the heating chamber 2 is higher than the temperature at the center of the heating chamber 2. . However, since the temperature sensor 26 is exposed to the air in the heating chamber 2 sucked in from the circulation fan 11, it has almost the same temperature as the central portion of the heating chamber 2. Therefore, the temperature gradient between the temperature sensor 26 and the heating chamber 2 is small, and the temperature inside the heating chamber can be accurately detected.

If the partition plate 24 were not present, the air heated by the heater 19 would directly hit the temperature sensor 26, making it impossible to accurately measure the temperature inside the heating chamber 2, resulting in erroneous temperature control.

Furthermore, in order to move the temperature sensor 26 away from the heater 19, the heater is shaped into a substantially M-shape as shown in the figure, and the temperature sensor is configured so that it does not directly detect the radiant heat of the heater, so the atmosphere of the air sucked into the circulation fan It is designed to detect only temperature.

Effects of the Invention By providing the partition plate upstream of the temperature sensor in this way, the temperature sensor part is prevented from being directly hit by the hot air heated to a high temperature by the heater, and the air sucked into the center of the fan from the heating chamber is prevented from directly hitting the temperature sensor part. As a result, the temperature difference between the heating chamber and the temperature sensor becomes smaller.
The temperature within the heating chamber will be accurately controlled.

A further advantage of the present invention is that even if the room temperature suddenly drops, the thermal gradient between the heating chamber and the temperature sensor section is small, so that accurate temperature control within the heating chamber can be performed. In other words, when the room temperature is low, if there is no partition plate, the temperature sensor will be directly hit by the hot air heated by the heater, and even though the temperature inside the heating chamber is low, the temperature sensor will judge that the temperature has risen and Heater power is cut off even though the temperature has not reached the set temperature. If the heater becomes de-energized, the temperature sensor will be exposed to air at the same temperature as the heating chamber, and as mentioned above, the heater will immediately stop being energized. . Therefore, cooking ends before the temperature in the heating chamber reaches the set temperature. However, if a partition plate is provided upstream of the temperature sensor as in the present invention, the heater power will not be cut off until the temperature inside the heating chamber reaches the set temperature, and once the set temperature is reached, the heater power will begin to be interrupted, so no matter what the room temperature is, the heater will not turn off. The indoor temperature can be controlled to a constant temperature, allowing stable oven cooking regardless of room temperature.

The above effect was explained using an electric oven equipped with a high-frequency heating device, but an electric oven without high-frequency heating
The same effect can be obtained even with a gas oven by installing a partition plate upstream of the temperature sensor.

[Brief explanation of drawings]

FIG. 1 is a top sectional view of a main part of a heating device showing an embodiment of the present invention, and FIG. 2 is a front view of the electric heater mounting box. 2... Heating chamber, 9... Oven saucer, 10...
Circulation fan motor, 11... Circulation fan, 19...
...Electric heater, 22... Suction port, 23... Air outlet, 24... Partition plate, 26... Temperature sensor.

Claims (1)

[Claims] 1. A heating chamber for storing an object to be heated in the main body, an oven tray on which the object to be heated is placed in two upper and lower stages, an electric heater mounting box provided adjacent to a side wall or a back wall of the heating chamber, and A circulation fan and an electric heater for circulating hot air to and from the heating chamber, a partition plate for blowing out the hot air into the heating chamber, and a temperature sensor for detecting temperature are provided in the electric heater mounting box, and the electric heater is approximately M-shaped, a circulation fan is arranged approximately in the center of the approximately M-shape, and a temperature sensor is installed in the upper space of the circulation fan,
A heating device in which a partition plate is provided on the upstream side near the temperature sensor.