JP3128392B2 - microwave - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microwave oven for detecting the weight of an object to be heated and performing cooking in a state suitable for the weight.

[0002]

2. Description of the Related Art Conventionally, the weight of food in a heating chamber is detected as shown in, for example, Japanese Patent Publication No. 3-5492, and a heating time corresponding to the detected weight is determined. 2. Description of the Related Art There has been proposed a microwave oven that automatically controls a heating output, a heating mode, and the like to perform optimal heating cooking. In the microwave oven disclosed in Japanese Patent Publication No. 3-5492 or the like, when measuring the weight of food with a weight detection sensor, a circular mounting plate on which the food is placed is used to reduce the detection error. The plate was placed on a receiving table, and the weight of the food was detected while rotating the receiving table.

[0003] In recent years, there is a microwave oven provided with a heater in a heating chamber so as to cook gratin or bake cookies. That is, in this microwave oven, an oven cooking function is provided in addition to the microwave cooking function. In general, when cooking gratin or baking cookies, it is common practice to cook many foods on a mounting plate. However, in the microwave oven with the oven cooking function, the corners in the heating chamber cannot be effectively used, so that many foods cannot be oven-cooked. In other words, when cooking gratin or baking cookies, a circular placing plate is used, so that many foods cannot be placed on the placing plate.

[0004] Therefore, in order to make effective use of the corners in the heating chamber, it is conceivable to make the mounting plate square, for example. However, when the mounting plate is formed in a rectangular shape, the corner of the mounting plate hits the wall surface of the heating chamber and cannot be rotated. for that reason,
When a food is placed on a square mounting plate (hereinafter, referred to as a “square plate”) that cannot be rotated in the heating chamber and the weight is detected, the weight must be detected without rotating the square plate.

However, when the food is placed at a position eccentric from the center of the square plate, the eccentric load causes the square plate to be displaced from the pedestal, and a part of the square plate comes into contact with the wall surface of the heating chamber. Also, it comes into contact with the geared shaft insertion part of the cradle and the bearing part of the cradle. For this reason, the weight of the food transmitted to the weight detection sensor via the cradle and the geared shaft is dispersed. As a result, the weight is not correctly transmitted to the weight detection sensor, which causes a failure in heating and cooking the food. So, when cooking food on a square plate,
It is desired to improve the weight measurement accuracy at the time of so-called load eccentricity.

In order to improve the weight measurement accuracy at the time of load eccentricity as described above, the present applicant has set a pre-determined weight measurement time before heating and cooking when placing food on a square plate and cooking. I thought that it would be better to rotate the cradle on which the square plate was placed. The present invention, in view of the above,
It is an object of the present invention to provide a microwave oven that can accurately measure the weight of food on a square plate even when cooking using a square plate.

[0007]

The object of the present invention is to provide a heating chamber for accommodating an object to be heated, a rotatably provided in the heating chamber, and a circular or non-rotatable shape in contact with a wall surface of the heating chamber. A receiving table on which a heated object mounting dish is placed, a rotating shaft extending vertically supporting the receiving table, a driving unit for rotating the receiving table by rotating the rotating shaft, and a lower end of the rotating shaft in contact with the rotating table. A weight detection sensor that detects the weight of the object to be heated transmitted from the rotating shaft, and a heated object mounting plate that is in a shape that cannot be rotated by being in contact with the wall surface of the heating chamber are mounted on the receiving table. Occasionally, the apparatus includes a rotation control unit that drives the driving unit to rotate the cradle only during a predetermined weight measurement time before cooking.

[0008]

According to the above-mentioned means for solving the above problems, when the object-to-be-heated placed in a non-rotatable shape in contact with the wall surface of the heating chamber is placed on the receiving table, the rotation control means sets the predetermined value before the heating and cooking. The driving means is driven to rotate the cradle only during the weight measurement time. Therefore, when the object to be heated is placed at a position eccentric from the center of the placing plate, a part of the placing plate comes into contact with the wall surface of the heating chamber and stops, and the weight of the food to be transmitted to the weight detection sensor is transmitted. However, even if the mounting plate is stopped, the driving force from the driving means is transmitted to the rotating shaft, and as a result, the rotating shaft slides out with respect to the cradle and continues to rotate. Frictional resistance is reduced.

As a result, the weight of the object to be heated is accurately transmitted to the weight detection sensor via the cradle and the rotating shaft.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a diagram schematically illustrating the configuration of a microwave oven according to one embodiment of the present invention. Referring to FIG. 1, reference numeral 1 denotes a heating chamber for storing food, and heating chamber 1 is formed in a box shape having an opening on a front surface. A door 2 (see FIG. 3) is provided at an opening of the heating chamber 1 so as to be openable and closable.

In the heating chamber 1, a receiving table 3 and a heater 4 are provided. The cradle 3 is arranged at the bottom of the heating chamber 1, and a circular or rectangular food placing plate 5 that cannot be rotated in contact with the wall surface of the heating chamber 1 is placed thereon. Heater 4
Is disposed above the heating chamber 1 and heats the food placed on the placing plate 5 from above. In the following description, a circular placing plate is referred to as a “circular plate”, and a square placing plate is referred to as a “square plate”.

A geared motor 6 for rotating the receiving table 3 is disposed below the heating chamber 1, and below the geared motor 6, the food placed on the placing plate 5 is disposed. A weight detection sensor 7 for detecting weight is provided. As the weight detection sensor 7, a strain gauge, a pressure sensor, or the like is used. Further, a magnetron 8 that oscillates a microwave and a waveguide 9 that propagates the microwave oscillated from the magnetron 8 and supplies the inside of the heating chamber 1 are provided on a side of the heating chamber 1.

The heater 4, the geared motor 6, and the magnetron 8 are controlled by a control circuit 10. Control circuit 1
Reference numeral 0 denotes a microcomputer including a CPU, a data RAM, and a program ROM, which performs control according to a program stored in the ROM in advance. In particular,
The control circuit 10 includes a detection signal from the weight detection sensor 7, a heating selection switch for selecting oven heating by the heater 4 and microwave heating by the magnetron 8, and a mounting plate selection for inputting the use of a circular plate and a square plate. And an operation signal from an operation panel P having switches and the like.
The driving of the heater 4, the geared motor 6 and the magnetron 8 is controlled based on these signals.

FIG. 2 is an enlarged sectional view of a main part showing the relationship between the geared motor and the weight detection sensor. Referring to the figure, a geared motor 6 for rotating the receiving table 3 includes:
A motor 62 serving as a drive source, a geared shaft 63 supporting the cradle 3, a drive gear 64 fitted externally to the output shaft of the motor 62 so as to be coaxially rotatable, and coaxially rotatable with the geared shaft 63 in a casing 61. And a driven gear 65 meshed with the drive gear 64 and a pair of bearings 66 and 67 for rotatably bearing the geared shaft 63. The geared shaft 63 extends vertically through the casing 61, and its lower end is in contact with the upper surface of the weight detection sensor 7. Therefore, when a downward force is applied to the geared shaft 63, the geared shaft 63 moves downward and pushes the weight detection sensor 7. Therefore, the weight of the placing plate 5 and the weight of the food placed on the placing plate 5 are transmitted to the weight detection sensor 7 via the receiving stand 3 and the geared shaft 63.

In the above configuration, when cooking with a circular dish as usual, when the circular dish on which the food is placed is placed on the cradle 3 and the door 2 is closed, the geared motor is driven. The weight of the food is detected by the weight detection sensor 7 while rotating the receiving base 3 around the geared shaft 63 by the use of the sensor 6. Data detected by the weight detection sensor 7 is input to the control circuit 10. The control circuit 10 determines a heating time, a heating output, a heating mode, and the like corresponding to the detected weight, and
The heater 4 or the magnetron 8 is controlled while keeping the rotation of.

On the other hand, when performing heating cooking using the square plate, first, the placing plate selection switch on the operation panel P is operated. Then, when the square plate on which the food is placed is placed on the receiving table 3 and the door 2 is closed, the control circuit 10 determines a predetermined value before the heating and cooking based on the placement plate selection signal of the operation panel P. The cradle 3 is rotated by the geared motor 6 for the weight measurement time. When the weight measurement time has elapsed, the geared motor 6 is stopped. Then, the control circuit 10 determines a heating time, a heating output, a heating mode, and the like corresponding to the weight detected by the weight detection sensor 7, and controls the heater 4 and the magnetron 8 with the rotation of the cradle 3 stopped. Will be

When the weight of the food placed on the square plate is measured as described above, the square plate 51 rotates with the rotation of the cradle 3 as shown by the dotted line in FIG. However, the square plate 51 collides with the wall of the heating chamber 1 or the like immediately after the rotation of the receiving table 3 and stops. At this time, as shown in FIG. 4, when the food C is placed at a position eccentric from the center of the square plate 51,
A part of the food 1 comes into contact with the wall surface of the heating chamber 1 and also comes into contact with the geared shaft insertion portion of the cradle 3 and the weight of the food to be transmitted to the weight detection sensor 7 is dispersed. That is, when a force is applied obliquely downward to the geared shaft 63, friction occurs at the portion supporting the geared shaft 63, and the geared shaft 63 does not lower in proportion to the load. However, even if the square plate 51 stops, the driving force from the motor 62 is transmitted to the geared shaft 63. As a result, the geared shaft 63 slides out with respect to the pedestal 3 and continues to rotate, so that the frictional resistance with each of the contact surfaces is reduced. As a result, the weight of the food is accurately transmitted to the weight detection sensor 7 via the cradle 3 and the geared shaft 63.

As described above, according to the microwave oven, the space in the heating chamber can be effectively used by using the square dish, and the weight of the food on the square dish can be accurately measured.
As a result, the food can be cooked without failure. By the way,
Table 1 shows comparison data of the weight detection error between the case where the cake is placed eccentrically on the square plate 51 and the cradle 3 is rotated and the case where it is stopped in a so-called load eccentric state.

[0019]

[Table 1]

As is clear from Table 1, when 500 g of cake is placed on the square plate 51 with the load eccentric, the error at the time of stopping the cradle 3 is Δ196 g, while the error at the time of rotation is Δ196 g. The error was Δ2g. When 1000 g of cake was placed on the square plate 51 in an eccentric load state, the error at the time of stopping the cradle 3 was Δ246 g, while the error at the time of rotation was Δ15 g. Thus, the cradle 3
When the square plate 51 is placed thereon, the weight of the food is measured by rotating the cradle 3 only for a predetermined weight measurement time before the heating and cooking, so that weight detection can be performed with a very small error. It turned out to be like that.

It should be noted that the present invention is not limited to the above-described embodiment, and it goes without saying that many modifications and changes can be made within the scope of the present invention. In the above embodiment, the use of the square plate 51 is input by operating the placement plate selection switch provided on the operation panel P. However, for example, an optical sensor at the corner of the heating chamber 1 is arranged. It may be configured to automatically detect that the square plate 51 is placed on the cradle 3.

[0022]

As is apparent from the above description, according to the present invention, when the object-to-be-heated, which has a shape that cannot be rotated due to contact with the wall surface of the heating chamber, is placed on the receiving table,
Rotation control means, only for a predetermined weight measurement time before cooking, to drive the drive means to rotate the cradle,
Even if a part of the mounting plate comes into contact with the wall surface of the heating chamber and stops, as a result of the rotation driving force being transmitted to the rotating shaft, the rotating shaft starts sliding with respect to the cradle and continues rotating.

As a result, the frictional resistance with each of the contact surfaces is reduced, and as a result, there is an excellent effect that the weight of the object to be heated is accurately transmitted to the weight detection sensor via the cradle and the rotating shaft.

[Brief description of the drawings]

FIG. 1 is a diagram showing a simplified configuration of a microwave oven according to one embodiment of the present invention.

FIG. 2 is an enlarged sectional view of a main part showing a relationship between a geared motor and a weight detection sensor.

FIG. 3 is a plan view showing a rotating state and a stopped state of the square plate.

FIG. 4 is a diagram showing a state in which food is eccentrically placed on a square dish.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heating room 3 Receiving stand 5 Placement tray 51 Square dish 6 Geared motor 62 Motor 63 Geared shaft 7 Weight detection sensor 10 Control circuit P Operation panel

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Hiroyuki Uebashi 2-18-18 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Inventor Katsuta Noda 2--18 Keihanhondori, Moriguchi-shi, Osaka (56) References JP-A-6-331149 (JP, A) JP-A-3-25221 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F24C 7/02 315 F24C 15/16 H05B 6/68 310 H05B 6/68 320

Claims (1)

(57) [Claims] 1. A heating chamber for accommodating an object to be heated, and a receiver on which a heating object mounting plate rotatably provided in the heating chamber and having a circular or non-rotatable shape in contact with a wall surface of the heating chamber. A table, a rotating shaft extending up and down to support the receiving table, a driving means for rotating the receiving table by rotating the rotating shaft, and a heating target contacting the lower end of the rotating shaft and transmitted from the rotating shaft. A weight detection sensor that detects the weight, and when the object to be heated having a shape that cannot be rotated in contact with the wall surface of the heating chamber is placed on the receiving table, only a predetermined weight measurement time before heating and cooking is performed. And a rotation control means for driving the driving means to rotate the cradle.