JPH0247367Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a weight detection device for a microwave oven that can detect the weight of an object to be cooked placed on a turntable.

<Prior Art> A microwave oven is known that automatically detects the weight of an object to be cooked when the object is placed on a turntable installed in a heating chamber of the microwave oven. Conventional weight detection devices of this type are
As shown in FIG. 5, the support roller 31 supports the turntable and rotates on the inner bottom surface of the heating chamber bottom wall 30. A detecting section 33 of a piezoelectric element 32 projected upward is provided, and a voltage is generated in the piezoelectric element 32 due to the load received from the support roller 31, and the weight of the food placed on the turntable is detected from the output thereof. is configured to do so.

However, the conventional weight detection device described above has a structure in which the height setting position of the detection section 33 of the piezoelectric element 32 cannot be adjusted and is fixed by the fixing member 34.
It becomes extremely difficult to accurately set the protrusion height position. In particular, the inner circumferential surface of the heating chamber is coated, and the coating thickness varies by about 80μ to 200μ, and the thickness of the various constituent members that form the heating chamber also varies by about 100μ.
Under such conditions, it is extremely difficult to accurately set the protrusion height of the detection section 33 with respect to the inner bottom surface of the heating chamber bottom wall 30.
There was a problem in that the output level of the piezoelectric element 32 varied due to inaccuracy in the height setting position.

[Purpose of invention]

The present invention has been made in consideration of the above-mentioned conventional problems, and makes it possible to easily and accurately set the height of the detection section of the piezoelectric element that protrudes upward from the bottom wall of the heating chamber. The object of the present invention is to provide a weight detection device for a microwave oven that can maintain a constant output level of a piezoelectric element and perform highly accurate weight detection.

[Structure of the idea]

The weight detection device for a microwave oven according to the present invention detects a voltage generated in a piezoelectric element due to a load received from a support roller rotating on the upper surface of the bottom wall of a heating chamber while supporting a turntable, and thereby detects a voltage generated in a piezoelectric element on a piezoelectric element. In a microwave oven configured to detect the weight of an object to be cooked, a detection section of a piezoelectric element is made to face a hole in the bottom wall of the heating chamber formed on the rotation locus of the support roller and protrude upward; The present invention is characterized in that the set height of the detecting section is configured to be adjustable, so that the protruding height of the detecting section can always be accurately set.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 4.

As shown in FIGS. 1 and 2, a magnetron 2 is installed on the top wall of the heating chamber 1, and a turntable is placed on the inner bottom of the heating chamber 1 on which the food to be cooked A is placed. 3 is installed. This turntable 3 has a roller arm 4 having a shape in which three arms extend radially as shown in FIG.
It is supported by being placed on support rollers 5 attached to the ends of each arm, and each support roller 5 rotates on the same trajectory while rolling on the bottom wall 6 of the heating chamber 1. Thus, the turntable 3 is configured to be able to rotate inside the heating chamber 1.
Further, as shown in FIG. 1, a motor 7 is installed on the lower surface side of the bottom wall 6 of the heating chamber and is fixed by a motor mounting member 8. A roller arm 4 is removably pivoted.

On the other hand, as shown in FIGS. 3 and 4, a penetrating hole 6a is provided at an arbitrary position on the rotation trajectory of the support roller 5 in the bottom wall 6 of the heating chamber 1. A circular piezoelectric element 11 is disposed below and on the lower surface side of the bottom wall 6. This piezoelectric element 11 has a detecting portion 12 that protrudes upward, and the detecting portion 12 is inserted into the hole 6a from below the bottom wall 6.
It is installed in such a way that it penetrates and protrudes upwards. Furthermore, a fixed angle 13 fixedly installed by spot welding is attached to the lower surface side of the bottom wall 6, and a fixed member 14 is screwed to the fixed angle 13. The fixing member 14 has a female threaded portion formed on its inner circumferential surface, and a height adjusting member 15 having a male threaded portion formed on its outer circumferential surface.
It is integrally constructed by screwing into the screw hole of. An inner stepped portion 15a is formed on the height adjustment member 15, and the piezoelectric element 11 is connected to the inner stepped portion 15a.
is supported from below, and is configured such that the set height of the piezoelectric element 11 can be arbitrarily adjusted by displacing the height adjusting member 15 with respect to the fixing member 14.

In the above configuration, if the protruding height of the piezoelectric element detection unit 12 from the top surface of the bottom wall 6 of the heating chamber 1 is not at a predetermined height position, the height adjustment member 15 is adjusted by rotating with respect to the fixing member 14. Then, the set height of the detection section 12 of the piezoelectric element 11 is adjusted. When the motor 7 is driven, the roller arm 4 rotates, and following this, each support roller 5 turns while rotating on the upper surface of the bottom wall 6, and a piezoelectric element detection section protruding from the bottom wall 6 follows the turning trajectory. Turn while overcoming 12. When the detection part 12 of the piezoelectric element 11 receives a load from above by each support roller 5, a voltage is generated in the piezoelectric element 11, and this voltage is detected to determine the weight of the food A placed on the turntable 3. This is to detect.

[Effect of idea]

As described above, the weight detecting device for a microwave oven according to the present invention has a detecting section of a piezoelectric element facing the hole in the bottom wall of the heating chamber formed on the rotation locus of the support roller and protruding upward. Since the set height of the detection part is configured to be adjustable, it is possible to easily set the protrusion height of the piezoelectric element detection part from the top surface of the bottom wall of the heating chamber to an accurate constant value. . Therefore, an output signal with little error is obtained from the piezoelectric element based on the load received from each support roller, and the weight of the food to be cooked can be detected and measured accurately and with high precision. Even if there are variations in the coating thickness of the heating chamber or the plate thicknesses of the various constituent members that form the heating chamber, these errors can be absorbed by adjustment using the height adjustment member, thereby eliminating variations in the output level from the piezoelectric element. This has the effect of preventing this from occurring.

[Brief explanation of the drawing]

Fig. 1 is a vertical cross-sectional view of a main part showing an embodiment of the present invention, Fig. 2 is an overall longitudinal cross-sectional view of a microwave oven to which the present invention is applied, and Fig. 3 shows the turning locus of the support roller in Fig. 2. FIG. 4 is a longitudinal cross-sectional view showing an enlarged view of the main parts of the present invention, and FIG. 5 is a vertical cross-sectional view showing a conventional example. 1 is a heating chamber, 3 is a turntable, 4 is a roller arm, 5 is a support roller, 6 is a bottom wall, 6a is a hole, 11 is a piezoelectric element, 12 is a detection part, 14 is a fixing member, 15 is a height adjustment It is a member.

Claims (1)

[Claims for Utility Model Registration] 1. Detecting the voltage generated in the piezoelectric element due to the load received from the support roller rotating on the upper surface of the bottom wall of the heating chamber while supporting the turntable, and thereby detecting the voltage generated in the piezoelectric element In a microwave oven configured to detect the weight of a piezoelectric element, a detection section of a piezoelectric element is made to face a hole in the bottom wall of the heating chamber formed on the rotation locus of the support roller and protrude upward; A weight detection device for a microwave oven, characterized in that the setting height is freely adjustable. 2 In the above-mentioned detection section, the set height of the detection section can be freely adjusted by screwing a height adjustment member that supports the piezoelectric element into a screw hole of a fixing member fixed to the bottom wall of the heating chamber. A weight detecting device for a microwave oven according to claim 1, which is a utility model registered as claimed in claim 1.