JPS58160744A - Hot air circulating type oven - Google Patents

Abstract

PURPOSE:To improve the uniform heating function by providing suction holes at the center of the upper surface of a heating chamber having square-shaped upper surface and blow-off holes at four corners, connecting the section hole to the blow-off holes by means of a cross air guide, and accommodating therein a heater and a fan. CONSTITUTION:Foodstuff placing shelves 37 formed by a wire material are provided in a substantially square heating chamber 21 having a horizontal section, and suction holes 38 are formed at the substantially central part of the heating chamber 21 and blow-off holes are formed at four corners thereof. These suction holes and blow-off holes are connected to each other by an air guide 22, and the fan 23 and the heater 24 are accommodated in a space surrounded by the air guide 22 and the upper surface wall of the heat chamber 21. The fan 23 is positioned on the suction hole 38, and the center of the rotation of the fan is set at the substantially central part of the upper surface of the heating chamber 21. As a result, as the uniform heating function is maintained excellently, simultaneous cooking at two upper and lower stages, even a large cake having a size in such a degree as contacting the fan wall surfaces of the heating chamber, can be baked at least on its upper and lower surfaces.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention aims at improving the uniform heating performance and downsizing of a hot air circulation type oven that can simultaneously cook on two upper and lower stages, and is particularly premised on being combined with a microwave oven.

Figure 1 is a horizontal sectional view of the main part of the conventional example, and Figure 2 is its 0-
C/ sectional view (principal part vertical section m1 view). An air guide 2 base 22 is provided behind the rear wall of the heating chamber 21 having a substantially rectangular parallelepiped shape, and a fan 23 and a heater 24 are housed therein, and the fan is rotated by a fan motor 26. Hot air is blown out along the left and right walls as shown by the arrows against the object to be cooked (assuming a circular sponge cake), and is sucked in from the center to the rear.

Further, the air is blown out along the top and bottom surfaces, and is sucked rearward through the middle of the objects to be heated, which are placed on the upper and lower levels.

This method has been widely used in the past, but its drawbacks are: (1) Since the fan is still rotating, both the blowout (L) suction air and the suction air turn in the same direction as the fan, creating a spiral shape. An imbalance occurs in the heat distribution, making it difficult to improve uniform heating performance.

(2) When the food to be cooked becomes large, the left and right ends of the food are directly exposed to the hot air, causing it to burn more quickly. To avoid this, it was necessary to make the left and right walls project outward, as shown by the two-dot chain lines in Figure 1.

In addition, 1. In Figure 2, part 8 of the rear wall is drawn with a broken line, 1, which means that this is a group of small holes. In other words, since the present invention is based on the premise of having a microwave oven function,
This group of small holes allows wind to pass through and blocks radio waves.

FIG. 3 is a vertical sectional view of the main part of the same conventional example.

This method takes advantage of the swirling of the wind, which was mentioned in defect (1) in Figure 1, and the fan 23 is installed at the center of the top surface, around the heater i, and along the rotation axis of the fan. In addition, it creates a vertical vortex to achieve uniform heating.

However, this method does not allow for one-cook, two-stage cooking, and if the food to be cooked is large, only the surrounding area will be burnt.

The present invention eliminates the above-mentioned drawbacks, provides excellent uniform heating performance, and provides 1.
The purpose is to realize an oven capable of two-stage cooking, and one embodiment will be described below with reference to the drawings. FIG. 4 is a perspective view of the heating chamber portion of the present invention. This is a view from the front right and slightly above, showing the door and insulation material that are essential for an oven.
Since the electrical wiring is well known, it has been omitted for the sake of brevity and clarity.

The heating chamber 21 is a rectangular parallelepiped box made of thin stainless steel plate, and the top surface (and therefore the bottom surface) is square.

The front surface G is an opening for putting in and taking out the food to be cooked, and is closed with a door (not shown). On the left and right walls are the upper and lower Mochima Sho 5
8-160744 (2) Two protrusions 31 are provided on the inside of the heating chamber by drawing. An air guide 22 is attached to the top surface. FIG. 7 shows the positional relationship between the air guide 22 and the top surface of the heating chamber.
It is a plan view seen from above. The air guide 22 is made by drawing an aluminized steel plate, and has a cross-shaped 90' rotationally symmetrical shape.

The center part, that is, the intersection of the crosses, is spiral-shaped (to be exact, the rotation angle θ and the distance r from the center to the wall are proportional), and the four tips of the crosses have an inclination of 46°. It's a wall. A flange 32 is provided around the entire circumference, a mounting hole 321L is bored in the flange 32, and the flange 32 is fastened to the top surface of the heating chamber with screw nuts. The upper surface of the heating chamber in the area corresponding to the tip of the cross...A group of small holes are provided in the thinly painted area 33 surrounded by a dashed line, and a circular hole is also formed in the center of the upper surface of the heating chamber at 11. A group of small holes 38 are provided.A motor 26 is fixed at the center and upper side of the air guide, and its rotating shaft passes through the center of the air guide and rotates within the space formed by the upper surface of the heating chamber.

Fix the pin 23. A perspective view of the fan is shown in FIG. It is a 6-beam type made by pressing a single piece of aluminized steel plate, with a hole in the center for fixing to the motor shaft, and radial wings around the circumference formed by bending. FIG. 9 is a perspective view of the heater 24. It is a sheathed heater in the form of a two-turn coil, with a fixing fitting 34 provided on the coil part.
It is fixed to the air guide with screw nuts using a hole drilled in the tip of the air guide and two screws drilled in the mounting bracket 36 provided on the drawer. The position is a position surrounding the fan 23 as shown in FIG. As shown in FIG. 4, the pull-out portion projects outward from above the air guide. A thermistor 36 is attached next to this, and a heat sensitive part (not shown) is exposed into the air guide. FIG. 10 is a perspective view of a slatted mesh 37 (food shelf), which is made by welding iron wire and chrome plated. Slatted mesh 37 (placed on the protrusion 31). In order to clarify the positional relationship of each component, the cross-section 5-5' in Fig. 4 is shown in Fig. 6, and the cross-section B-B' in Fig. 6. Both are vertical sectional views passing through the center of the upper surface of the heating chamber. Slatted net 37
is indicated by a two-dot chain line. Both Figures 6 and 6 have a nearly symmetrical shape, with the motor 26. )6 ・, Anne 23. A heater 24 and a group of small circular holes 38 formed in the center of the upper surface of the heating chamber are arranged. Slatted net 37 (2
The thinly painted shape drawn on top of the dashed dotted line represents a sponge cake.

Next, the effect will be explained. When the rotating shaft of the motor 26, and therefore the fan fixed to it, rotates, the air inside the heating chamber passes through a group of small circular holes opened in the center of the upper surface of the heating chamber opposite to the rotating shaft of the motor 26, and a space is created by the air guide and the upper surface of the heating chamber. It is guided inside, then receives heat from a heater, and is divided into four parts.
It passes through four passages, passes through a group of small holes 33, and is blown into the heating chamber.

The reason why the center of the air guide is spiral is to smooth the flow of air. Air guide is 90'
Since it is rotationally symmetrical, the wind blown out from the four small hole groups 33 is divided into approximately four equal parts. These four groups of small holes are opened near some of the four corners on the top surface of the heating chamber, and the air from the center to some of the corners is blown into the heating chamber through the air guide. Part of the corner (4
Flows neatly along the corners). A portion of it reaches the bottom of the heating chamber, page 7, and flows to the center. The rest flows around the center in the middle. As shown in Figure 6, the cake that reaches the bottom of the C along the four corners heats the surface of the sponge cake placed on the lower level and rises to the top. On the way, part of the liquid heading towards the center passes through the middle of the upper and lower sponge cakes (thus heating the upper part of the lower sponge cake and the F section of the upper sponge cake) and rises to the top. This upward force and the force directed from the four corners to the center are generated by suction through the small holes 38 due to the rotation of the fan described above. Because the fan rotates, the wind that rises from the four corners to the center and then to "-" swirls as shown in the 11th illustration. FIG. 11 is a simplified version of FIG. 7, and the arc-shaped arrow drawn in the center indicates the direction of rotation of the fan. The dashed line indicates the direction of the wind. In other words, a vortex is created that rotates in the same direction as the rotation of the fan. This allows the sponge cake to be heated evenly. In addition, in Fig. 11, the area surrounded by the circle and the square is 39, and the small hole group 33.
This is a preferable location for installing. This is because, for example, in an extreme example, the size is almost equal to the circle in Fig. 11, JP-A-58-
160744 (3) When heating the sponge cake, the thin coating range is 39
Since there are no particular obstructions from the top surface to the bottom surface of the heating device, the wind blown from the small hole group 33 passes through this portion and reaches the surface of the sponge cake, so that the cake can be baked. As is well known, in order to bake cakes and bread, it is necessary to apply heat from both sides of the top. In this respect, for example, in the conventional example shown in Fig. 3, hot air is blown from almost the entire plane, so when heating a large cake, such as the relationship between a square and a circle in Fig. 11, it is difficult to heat the cake. The r-plane of is hardly heated. Even in the case of this example, with a cake of such a large size, the part near the blowing part (small hole group 33) will be slightly burnt black, but since the main part of the hot air reaches the cake surface F, as shown in Fig. 3. Reiyoshi makes a big difference. It goes without saying that the smaller the cake size, the better the uniform heating performance.

To summarize, the present invention provides an air inlet at the center of the upper surface of a heating chamber having an approximately square upper surface, and air outlets at the four corners, which are connected by a cross-shaped air guide, and a heater is installed in 9 bays and 7' of the heating chamber. By housing the fan and rotating the fan in the center of the top surface, it is possible to simultaneously cook two stages of one dish while maintaining good uniform heating performance, and the large circular shape almost touches the four walls of the heating chamber. It also made it possible to bake cakes on the top F side.

As described above, according to the present invention, an oven with excellent uniform heating performance, capable of simultaneous cooking on two upper F' stages, can be realized.

[Brief explanation of the drawing]

Figure 1 is a schematic horizontal cross-sectional view of a conventional oven, and Figure 2 is the same.
A schematic vertical cross-sectional view taken along the line -c', FIG. 3 is a schematic vertical cross-sectional view of another conventional example, and FIG. 4 is a perspective view showing main parts of the present invention.
Figures 6 and 6 are lines A-A' and B-B' in Figure 4, respectively.
FIG. 7 is a cross-sectional view along a line, and FIG. 8 is a plan view showing the relationship between the upward direction of the heating chamber and the air guide. FIG. 9 and FIG. 1o are perspective views of the fan and heater grating, respectively, and FIG. 11 is a schematic diagram of FIG. 7 showing the blow-off section. 21...KafiL, 23...Fan,
24...hi1 o...7-ter, 37...slatted net, 38...
Small intake hole group, 22...Air guide. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure IJM2 figure! Figure I5 Figure 7 Figure 4 “98.4 Figure 10 Figure 11

Claims (1)

[Claims] It has a heating chamber with an approximately square horizontal cross section, a fan, a heater, a food shelf made of wire rods, and an air guide, and an air intake hole is located approximately in the center of the top surface of the heating chamber, and air is blown out near the four vertices. A hole is made for the heating chamber, and the exhaust and blowout holes are connected with the air guide, and a fan and a heater are housed in a space surrounded by the air guide and the upper wall of the heating chamber, and the fan is positioned above the intake hole. , a hot air circulation oven whose center of rotation is approximately at the center of the top of the heating chamber.