JPH07208745A - Heating cooker - Google Patents

Abstract

PURPOSE:To detect an accurate food weight by a simple structure despite a shape of a placing tray and to further prevent discharge due to approaching of the rectangular tray rotated to detect to a peripheral wall of a heating chamber. CONSTITUTION:A disclike bearer 6 is coaxially fixed to a rotary support shaft 5 disposed substantially at a center of a heating chamber 1. A rectangular placing tray 2 is placed to be supported to the bearer 6, and a food weight on the tray 2 is detected via a supporting load of the shaft 5. In this case, the shaft 5 and the bearer 6 are rotated to eliminate influence of deviation of the placing position on the tray 2, thereby obtaining a detection result accurately corresponding to the real weight of the food. The rotation of the tray 2 upon rotation of the bearer 6 is restricted by the contact with spacers 12 made of insulator mounted near the corner of a peripheral wall of the chamber 1, and an insulating gap corresponding to the thickness of the spacer 12 is obtained between the tray 2 and the peripheral wall of the chamber 1. In the case of following microwave heating, the discharge between the both is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating cooker in which heating control is performed so as to obtain an appropriate heating state according to the weight of food in a heating chamber.

[0002]

2. Description of the Related Art The weight of food to be cooked is detected in a heating chamber, and the food is controlled under appropriate heating conditions by heating control that controls one or both of a heating time and a heating output based on the detected weight. A heating cooker adapted to automatically cook has been put into practical use. This heating control is a microwave oven that uses microwaves introduced into the heating chamber to heat the food, an electric oven that uses the heat rays emitted by the heater inside the heating chamber, an microwave oven that uses both the microwave and the heater, etc. It is widely practiced in heating cookers equipped with electrically controllable heating means. In the microwave oven, switching of the heating method between microwave heating and heater heating is also included in the heating control.

In carrying out such heating control as described above, it is important to accurately detect the weight of food. This weight is detected as a support load of the above-mentioned plate which is detected by the load sensor by disposing a load sensor on the support part of the plate for placing food placed inside the heating chamber. . In many cases, the mounting plate is supported on a support shaft projecting substantially in the center of the bottom surface of the heating chamber, and the load sensor is a base end of the support shaft extending outside the heating chamber. It is arranged in a manner to support.

[0004]

However, when such an arrangement mode is adopted, when the food is placed at a position apart from the central portion of the placing plate which is the supporting portion by the support shaft, the food is placed. As a result, the load of the load sensor acts unevenly on the load sensor, and the detected load of the load sensor and the actual weight of the food do not correspond, and erroneous heating control is performed based on this detected load to obtain a satisfactory finished state. There is an inconvenience.

In a microwave oven that heats food by the action of microwaves, the spindle of the above-mentioned plate is used for the purpose of equalizing the action of microwaves on each part of the food and preventing uneven heating. A configuration has been widely adopted in which a rotary spindle that is rotationally driven about the center is used, and by rotating the rotary spindle, cooking is performed while rotating food together with a circular placing plate (turntable). . In this case, as disclosed in Japanese Utility Model Laid-Open No. 4-70903, the load sensor is arranged at the base end of the rotary support shaft to detect the load while rotating the mounting tray, whereby the above-mentioned mounting is performed. It is known that the influence of positional deviation can be eliminated and the weight of food can be accurately detected.

On the other hand, electric ovens, microwave ovens, etc.
In a heating cooker equipped with a heater as a heating means,
In order to make effective use of the internal volume of the heating chamber, a rectangular plate (square plate) having a flat shape corresponding to the bottom surface of the heating chamber is often used, and the supporting load of such a plate is circular. It is not possible to detect while rotating, as in the case of the mounting plate of.

In Japanese Laid-Open Patent Publication No. 4-29937, a pair of support rails extending in the front and rear direction are provided on opposite side walls of a heating chamber, and both side edges of a rectangular placing tray are supported by the support rails, respectively. A heating cooker is disclosed in which a load acting on a support rail is guided to a load sensor arranged outside the heating chamber via a transmission member and a link mechanism. With this configuration, it is possible to accurately detect the weight of the food on the rectangular plate, and the heating control based on the detection result can be performed without error.

However, this heating cooker requires a complicated mechanism for transmitting the supporting load of the placing plate to the load sensor, and has a drawback that it cannot be applied to a microwave oven having a turntable as the placing plate. In addition, in the microwave oven using the circular loading tray and the rectangular loading tray, separate load sensors are required to detect the weight of food on the respective loading trays, which further complicates the configuration. There is a problem of inducing

The present applicant has already proposed a heating cooker that solves the above problems (Japanese Patent Application No. 5-122792). This is a disk-shaped pedestal that is coaxially fixed to the tip of a rotary support shaft that projects from the center of the bottom of the heating chamber, and a circular or rectangular mounting tray is mounted and supported on this pedestal. It has been configured. When using a circular mounting tray, this mounting tray is rotated by the rotation of the rotating spindle due to the frictional resistance between it and the pedestal, and functions as a turntable to eliminate uneven heating. As described above, the weight of the food on the plate is accurately detected during the rotation by the load sensor provided at the base end of the rotary support shaft.

On the other hand, even in the case of using a rectangular mounting tray, the supporting load is detected while rotating the rotary support shaft. At the beginning of the rotation, the mounting tray rotates due to friction with the pedestal, and its peripheral portion is brought into contact with the peripheral wall of the heating chamber to be restrained, but the pedestal also stops after this. In order to continue idling against the friction with the placed plate, the load sensor acts on the load plate to support the food on the plate without bias, and the weight of the food is accurately detected. Is possible.

That is, in this heating cooker, a rectangular mounting plate is supported by a rotary supporting shaft for supporting a circular mounting plate serving as a turntable, and the heating cooking device is arranged at the base end of the rotating supporting shaft. The common load sensor enables accurate detection of the weight of food on both dishes, and also eliminates the need for a complicated mechanism. The error-free heating control based on the detection result ensures proper operation. It is an excellent cooked food.

However, when this configuration is adopted in a heating cooker utilizing microwave heating (microwave oven or microwave oven), as a result of the above-described weight detection, the peripheral edge of the placing plate and the peripheral wall of the heating chamber are in contact with each other. They are in contact with or in close proximity to each other, and since both of them are generally made of metal, a strong electric field generated in the heating chamber during the subsequent heating operation causes discharge between the two, which prevents normal heating. There is a risk.

The present invention has been made in view of the above circumstances, and enables accurate detection of food weight with a simple structure regardless of the shape of the plate, and for this detection. (EN) A heating cooker that prevents direct contact between a rotating rectangular placing plate and a peripheral wall of a heating chamber and effectively prevents generation of electric discharge between the two, thereby preventing heating failure. To aim.

[0014]

A heating cooker according to the present invention is supported by a tip end portion of a rotary support shaft projectingly provided on a bottom surface of a heating chamber, and is made of a metal having a planar shape corresponding to the bottom surface. A plate is provided, and the weight of the food placed on the plate is detected as a load acting on the rotating support shaft during rotation, and heating control is performed to perform appropriate heating according to the detected weight. The heating cooker according to claim 1, wherein the rotation of the placing plate accompanying the rotation of the rotation spindle is restrained while maintaining a predetermined gap between the peripheral edge of the placing plate and the peripheral wall of the heating chamber. It is characterized by including a spacer made of a material.

[0015]

According to the present invention, the rotation of the placing plate accompanying the rotation of the rotary support shaft when detecting the weight of food is restrained by a spacer made of an insulating material with a predetermined gap maintained between the peripheral wall of the heating chamber. The electric field strength generated between the two during the subsequent heating operation by microwaves is reduced to effectively prevent the occurrence of discharge that causes heating failure.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings showing the embodiments. FIG. 1 is a schematic diagram showing a configuration of a heating cooker according to the present invention. In the figure, 1 is a heating chamber, and the heating chamber 1
A plate 2 is placed on the bottom surface 10 of the. A magnetron 3 serving as a microwave oscillation source is fixed to the outside of one side of the heating chamber 1 via a waveguide 30 having an opening on the side wall on the same side. A heater 4 is attached to the.

FIG. 2 is an enlarged sectional view of an essential part showing the support structure of the mounting tray 2. As shown in the figure, in the central portion of the bottom surface 10 of the heating chamber 1, the axis of the bottom surface 10 is orthogonal to the rotation spindle 5
A disk-shaped receiving stand 6 is coaxially fixed to the tip of the rotary support shaft 5, and the placing tray 2 is mounted and supported on the receiving stand 6. There is. As the placing plate 2, a rectangular plate having a planar shape corresponding to the bottom surface 10 of the heating chamber 1 or a circular plate capable of rotating in the heating chamber 1 can be used. As shown in FIG. By fitting the annular protrusion 20 formed on the back surface side to the outer periphery of the pedestal 6, the movement in the radial direction is restrained and the pedestal 6 is supported concentrically.

The other side of the rotary support shaft 5 extends through the bottom plate of the heating chamber 1 to the outside and is connected to the geared motor 7. The geared motor 7 includes a motor main body 71 inside a housing 70 fixed to the lower portion of the heating chamber 1, and a drive gear 72 fitted to an output shaft of the motor main body 71, which is located in the middle of the rotary support shaft 5 penetrating the housing 70. The drive gear of the motor main body 71 is transmitted to the rotation support shaft 5 through deceleration by the drive gear 72 and the driven gear 73 to rotate the pedestal 6. There is.

FIG. 3 is a plan view from above schematically showing the supporting state of the rectangular mounting tray 2. As shown in this figure and FIG. 2, in the heating cooker according to the present invention, a predetermined thickness is provided near the four corners of the inner circumference of the heating chamber 1 in accordance with the height position of the plate 2 described above. Spacer 12 made of insulating material
12 ... are attached respectively. These spacers 12, 12 ...
The mounting position of is corresponding to the position at which the four corners of the mounting tray 2 first come into contact when the rectangular mounting tray 2 rotates as the pedestal 6 rotates. Spacer 1
2, 12 ... Bind the rotation of the rectangular plate 2 generated as indicated by the chain double-dashed line in FIG. 3 with a predetermined gap between the peripheral edge of the plate and the peripheral wall of the heating chamber 1. Make up.

The rotary support shaft 5 for supporting the pedestal 6 has a pair of upper and lower radial bearings 7 in the housing 70 of the geared motor 7.
The load in the thrust direction acting on the rotary support shaft 5 merely supported by the rotary shafts 4 and 75 penetrates the housing 70 and extends downward, and the load sensor 8 is arranged at the base end of the rotary support shaft 5.
To join. The load sensor 8 is only required to be capable of converting the supporting load of the rotary support shaft 5 into an electric signal, and for example, the deformation of the pressure sensitive body to which the supporting load is applied is converted into a resistance value or an electrostatic capacitance. It is possible to use a load sensor configured to take out by utilizing the change, but to the extent that the displacement of the rotation support shaft 5 due to the deformation does not hinder the engagement between the drive gear 72 and the driven gear 73 in the geared motor 7. Is required to be small.

The output of the load sensor 8 is given to the controller 9 as shown in FIG. 1, and the output of the controller 9 is the output of the heating chamber 1.
It is applied to the magnetron 3 and the heater 4 attached to the gear motor 7, and is also applied to the geared motor 7.
The control unit 9 includes a CPU, a data RAM, and a program R.
It is a microprocessor including an OM and performs a control operation of issuing an operation command to the magnetron 3 or the heater 4 and the geared motor 7 in accordance with a program stored in the ROM in advance. The input from the load sensor 8 is used to determine the operating time and output of the magnetron 3 or the heater 4, that is, one or both of the heating output and the heating time in the heating chamber 1.

In the heating cooker configured as described above, the food A to be cooked is placed on the placing plate 2 supported on the receiving stand 6, and the front door 13 of the heating chamber 1 (see FIG. 3). (See) and close the cooking process. At this time, the control unit 9 first issues an operation command for a predetermined time to the geared motor 7 to rotate the rotary support shaft 5 and the pedestal 6, while sequentially capturing the output of the load sensor 8 and averaging them. ,
The weight of the food A is recognized by reducing the weights of the plate 2, the pedestal 6 and the rotary support shaft 5.

The weight of the food A on the plate 2 is added to the load sensor 8 via the pedestal 6 and the rotary support shaft 5. In this addition mode, the weight of the food A on the plate 2 is increased. It changes with the deviation of the mounting position. When the circular loading tray 2 is used, the loading tray 2 rotates together with the food A on the upper side as the pedestal 6 rotates, and as a result, the load sensor 8 is loaded into the control unit 9 as described above. The output is a supporting load in a state where various deviations of the food A on the placing tray 2 occur, and the result of averaging these results eliminates the influence of the deviation on the placing tray 2,
It accurately corresponds to the actual weight of the food A.

On the other hand, when the rectangular loading tray 2 is used, the rotation of the loading tray 6 in accordance with the rotation of the pedestal 6 causes the four corners to contact the spacers 12, 12 ,. Although it is restrained in the state, the pedestal 6 freely rotates against the friction on the contact surface with the mounting tray 2 and is taken in by the control unit 9 as in the case where the circular mounting tray 2 is used. The output of the load sensor 8 is the loading plate 2
It becomes the supporting load in the state where various deviations occur in the food A above, and the result of averaging these is the food A on the platen 2.
It will accurately correspond to the actual weight of.

The control unit 9 determines the heating time and heating output required for heating and cooking the food A using the weight of the food A obtained as described above, and the result and the operation panel connected to the input side. According to the heating method set to P (see FIG. 1), a heating control operation for driving one or both of the magnetron 3 and the heater 4, which are heating means, is performed. Circular plate 2
Is used, the control unit 9 further issues a continuous operation command to the geared motor 7. By this operation, the food A is heated and heated properly on the rotating platen 2 by microwave heating by the action of microwaves generated by the magnetron 3, microwave heating by the heater 4, or a combination thereof. It is cooked under time.

On the other hand, when the rectangular loading tray 2 is used, the rotation of the pedestal 6 due to the transmission from the geared motor 7 is stopped, and the same heating is performed on the loading tray 2 in the stopped state. Cooking is done. At this time, the plate 2 is kept at the restrained position when the weight of the food A is detected, that is, the position where the four corners are brought into contact with the spacers 12, 12, ... A space corresponding to the thickness of each spacer 12, 12, ... Is secured, and these spacers 12, 12 ,.
Since it is made of an insulating material, when heating the microwave by the operation of the magnetron 3, the peripheral wall of the heating chamber 1 and the placing plate 2 are
The electric field strength between the edge and the edge of the electrode is kept at a sufficiently small level, and the occurrence of discharge between them can be effectively prevented. As a result, a good finished state can be obtained even when the rectangular mounting tray 2 is used.

The shape of the plate 2 (circular or rectangular) is
It is designated by operating a predetermined designating means (dish designating switch) provided on the operation panel P, and the above-described operation of the control section 9 is performed according to this designation.

In the above embodiment, the rectangular placing tray 2 is used.
4 are attached to the heating chamber 1 side for restraining the rotation of the heating chamber 1 and maintaining a gap between the heating chamber 1 and the peripheral wall of the heating chamber 1. This restraint is, as shown in FIG. Can be realized by a structure in which spacers 22 made of an insulating material are attached to the respective parts, and a part or the whole of the peripheral surface of the heating chamber 1 is subjected to a enamel treatment of a predetermined thickness, and this treated layer serves as a spacer. You may make it fulfill a function.

[0029]

As described in detail above, in the heating cooker according to the present invention, the placing plate having a shape corresponding to the bottom surface of the heating chamber is supported on the rotary support shaft through the pedestal, and this placing is performed. The weight of the food on the plate is detected as the supporting load of the rotating spindle while the pedestal is being rotated, so a detection result that accurately corresponds to the actual weight of the food can be obtained. In addition to obtaining a good finish in a stable manner, it is made of an insulating material that restrains the rotation of the rectangular placing dish that occurs with the pedestal when detecting the weight of food with a predetermined gap between it and the peripheral wall of the heating chamber. Since the spacer is provided, it is possible to effectively prevent a discharge generated between the two in the subsequent microwave heating, and there is no fear of heating failure due to this discharge, and the present invention has excellent effects.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a configuration of a heating cooker according to the present invention.

FIG. 2 is an enlarged cross-sectional view of a main part showing a support structure of a mounting tray.

FIG. 3 is a plan view schematically showing a supporting state of a rectangular placing tray.

FIG. 4 is a plan view showing a supporting state of a placing tray according to another embodiment of the present invention.

[Explanation of symbols]

 1 Heating Chamber 2 Placement Plate 3 Magnetron 4 Heater 5 Rotating Spindle 6 Cradle 7 Geared Motor 8 Load Sensor 9 Controller 12 Spacer 22 Spacer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroyuki Uehashi 2-5-5 Keihan Hondori, Moriguchi City, Osaka Sanyo Electric Co., Ltd.

Claims (1)

[Claims] 1. A metal mounting plate, which is supported by the tip of a rotary support shaft projecting from the bottom surface of the heating chamber and has a planar shape corresponding to the bottom surface, is mounted on the mounting plate. A heating cooker configured to detect the weight of food as a load acting on the rotating spindle during rotation, and to perform heating control so as to perform proper heating according to the detected weight. The heating characterized by comprising a spacer made of an insulating material for restraining the rotation of the placing plate according to the rotation of (1) while keeping a predetermined gap between the peripheral edge of the placing plate and the peripheral wall of the heating chamber. Cooking device.