JPS629128A - Weight-detecting device of electronic range - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

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 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. An example of a conventional weight detection device of this type will be explained below with reference to FIGS. 2 to 5.

As shown in FIGS. 2 and 4, a magnetron 2 is attached to the top wall of the heating chamber 1, and a turntable for placing the food A on the inner bottom of the heating chamber 1. 3 is installed. This turntable 3 is supported by being mounted on a support roller 5 attached to the tip of each arm of a roller arm 4 having a shape in which three arms extend radially as shown in FIG. The support rollers 5 are configured to rotate on the same trajectory while rolling on the bottom wall 6 of the heating chamber 1, so that the turntable 3 can rotate inside the heating chamber 1.

Further, as shown in FIG. 4, a motor 7 whose mounting is fixed by a motor mounting member 8 is installed on the lower surface side of the bottom wall 6 of the heating chamber, and a cup is attached to a drive shaft 9 of this motor 7. The roller arm 4 is removably pivoted by a ring 10.

On the other hand, as shown in FIGS. 3 and 5, a penetrating hole 6a is provided at an arbitrary position on the rotation locus of the support row 25 in the bottom wall 6 of the heating chamber 1. A circular piezoelectric element 11 is disposed below the bottom wall 6 and on the lower surface side of the bottom wall 6. This piezoelectric element 11 has a detection member 12 that protrudes upward, and the detection member 12 is installed so as to face and penetrate the hole 6a from below the bottom wall 6 and protrude upward. Furthermore, a fixed angle 13 fixed by spot welding is attached to the lower surface side of the bottom wall 6.
A fixing member 14 is screwed to the fixed angle 13. This fixing member 14 has a female threaded portion formed on its inner circumferential surface, and is integrally constructed by screwing a height adjusting member 15, which has a male threaded portion formed on its outer circumferential surface, into a screw hole of the fixing member 14. There is.

The height adjustment member 15 is formed with an inner circumference stepped portion 15a, and this inner circumference stepped portion 15. a supports the piezoelectric element 11 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 protrusion height of the piezoelectric element detection member 12 from the upper 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 rotation with respect to the fixed member 14. Then, the set height of the detection member 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 the piezoelectric element detection member protruding from the bottom wall 6 follows the turning trajectory. Turn while overcoming 12.

When the detection member 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.

With the above weight detection device, even if there are variations in the thickness of the coating on the circumferential surface of the heating chamber or the thickness of the various structural members that form the heating chamber, the error can be absorbed by adjusting the height adjustment member. This method can prevent variations in the output level from the piezoelectric element, but it is necessary to adjust the set height of each detection member when it is installed in the heating chamber, and the size of the heating chamber Considering the box-like shape of the pod, it was not suitable for Takayuki.

<Object of the Invention> The present invention has been made in view of the above, and includes a piezoelectric element detection unit consisting of a piezoelectric element, a piezoelectric element detection member, a fixing member, and an adjustment member. The aim is to improve mass productivity by making it possible to adjust the set height of the detection member with a single element detection unit.

<Example> Hereinafter, one example of the weight detection device of the present invention will be described based on the drawings.

FIG. 1 is a vertical sectional view of the weight detection mechanism section of the present invention;
The same reference numerals are given to the same or corresponding parts as in the conventional example, and the explanation thereof will be omitted. Piezoelectric element 11 as a weight detection element
is supported by the inner peripheral stepped portion 16a of the height adjustment member 16, and output lead wires 17, 17 are led out from holes 16b, 16c provided in the height adjustment member 16. The height adjustment member 16 is screwed onto the fixing member 18 and is integrated with the fixing member 18. A knob 19 of the detection member is inserted into the boss-shaped hole 18a at the center of the fixing member 18 so as to be able to slide up and down, and a circular knob 19 is fixed to the fixing member 18 with a plurality of screws 20 (one location in the figure). It is incorporated into a lid-shaped metal cover 21 with its tip protruding from a hole 21a provided at the center. That is, the piezoelectric element 11. Height adjustment member 16. Fixed member 1
8. Knob 19. The metal cover 21 is integrated with screws 20 to form a piezoelectric detection unit 22.

A fixed angle 13 is attached to the heating chamber bottom wall 6 by spot welding 9, and the piezoelectric detection unit is attached to the fixed angle 13 with a plurality of screws 23 (one in the figure).
It will be installed at. A hole 6b that is sufficiently larger than the tip of the knob 19 is provided in the bottom wall 6 of the heating chamber, and a protrusion 21b is provided on the upper surface of the cover 21 by, for example, half-bore processing in press processing to fit into the hole 6b. ing. Protrusion 21
The protruding height of b is set to be approximately equal to the thickness of the bottom wall 6 of the heating chamber, and the bottom wall 6 and the upper surface of the protrusion 21b are approximately flush with each other.

The roller 5 rolls on the bottom wall 6 in the direction of arrow A, and the cover 21
passes over the knob 19 and the piezoelectric element 1
Press 1 to obtain a signal according to the weight. The bottom wall 6 and the protrusion 21b are almost flush with each other, and even if there is a slight step, the step is sufficiently far away from the tip of the knob 19, so the impact that the step gives to the roller 5 is attenuated, and the roller 5 does not touch the knob 19. It has no effect once it arrives.

In addition, the amount of protrusion of the knob 19 (dimension 8) is important for weight measurement; if the amount of protrusion is too large, sideways force will be applied to the knob 19, and if the knob 19 falls below the rolling plane of the roller 5, the roller It is conceivable that the acceleration of gravity due to the falling of the roller 5 is applied, or that the roller 5 completely passes over the knob 19 and no output is obtained.

In the conventional example, after the weight detection mechanism is assembled in the heating chamber 1, the height adjustment member 15 is rotated to change the amount of screwing into the fixing member 14, and the amount of protrusion of the detection member 12 from the bottom wall 6 of the heating chamber 1 is adjusted. This method was not suitable for mass production, as the adjustment work was difficult and the large box (heating chamber 1) had to be moved. Since the detection mechanism is a small assembly called a piezoelectric detection unit, it is easy to adjust and suitable for mass production, and therefore allows for higher precision adjustment. Moreover, the heating chamber bottom wall 6
Even if a relatively large hole 6b is made in the hole 6b, the cover 21 can be fitted into the hole 6b, and the bottom wall 6 and the cover 2 can be connected at the 0 part.
1 are in contact with each other, leakage of high frequency radio waves from the hole 6b can be prevented.

<Effects of the Invention> 1. Since the height of the knob protruding from the top surface of the bottom wall of the heating chamber can be easily adjusted, output accuracy can be increased.

2. The amount of knob protrusion can be accurately adjusted using a small assembly separate from the heating chamber.

3. Adjustment and checking including the circuit of the weight detection mechanism can be performed by attaching it to a separate standard chassis without attaching it to the heating chamber, improving mass productivity.

4. The weight detection mechanism can be replaced freely, which is advantageous in terms of mass production and service.

[BRIEF DESCRIPTION OF THE DRAWINGS] Fig. 1 is a vertical cross-sectional view of essential parts showing an embodiment of the present invention, Fig. 2 is a longitudinal cross-sectional view showing the entire microwave oven, and Fig. 3 is a cross-sectional view of the support roller in Fig. 2. FIG. 4 is a longitudinal cross-sectional view of the bottom of the heating chamber of the conventional example, and FIG. 5 is a longitudinal cross-sectional view of the essential parts of the 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, 6b is a hole, 11 is a piezoelectric element, 16 is a height adjustment member, 18 is a fixing member, 19 is a detection member, 21 is a cover, and a piezoelectric detection unit. Agent Patent attorney Aihiko Fuku (and 2 others) Figure 1 Figure 2

Claims (1)

[Claims] 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 weight of the food to be cooked on the turntable. In the weight detection device for a microwave oven, a part of the bottom wall of the heating chamber is formed facing the hole formed on the rotation trajectory of the support roller, and a detection member of a piezoelectric element is inserted into the heating chamber. 1. A weight detection device for a microwave oven, comprising a piezoelectric detection unit having a cover that is penetrated through the cover, and configured to freely adjust the set height of the detection member relative to the surface of the cover on the heating chamber side.