JP2910480B2 - Weight sensor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a weight sensor used for a cooking device such as a microwave oven.

[0002]

2. Description of the Related Art As shown in FIG. 7, a conventional weight sensor of this type is a rotating round plate for cooking as a weighing dish 3 installed in a cooking chamber 2 through a weight transmitting unit 4. The weight detection unit 1 supports the entire weight of the food 5 and the cooking pan. In such a configuration, the control unit 6 operates the magnetron 7 according to the weight of the food 5 detected by the weight detection unit 1. The radio wave radiated from the magnetron 7 is introduced into the cooking chamber 2 through the waveguide 8 to cook the food 5.

[0003]

However, in the above-described structure, a heavy food such as a casserole is accidentally dropped on a cooking round plate, When a load equal to or greater than the maximum allowable load is applied to a cooking round plate, there has been a problem that the weight detection unit 1 malfunctions or breaks, making it impossible to perform heating cooking.

The present invention solves the above-mentioned conventional problems, and suppresses an impact load to a weight detecting portion due to a drop load or prevents a load exceeding a maximum allowable load from being applied to the weight detecting portion. It is an object of the present invention to provide a weight sensor having a configuration.

[0005]

In order to solve the above-mentioned problems, a weight sensor according to the present invention comprises a weighing dish on which an object is placed, and the weighing dish supported rotatably or vertically.
A weight transmitting unit that transmits the weight of the weighing dish via an elastic body that is vertically expandable and contractable, and a weight detecting unit that detects the weight transmitted by the weight transmitting unit.

[0006] Then, the weight transmitting portion includes a hollow cylindrical body,
It is composed of two vertically movable pillars inscribed in the hollow tubular body and provided in the hollow tubular body, and a vertically stretchable elastic body sandwiched between the two pillars, and has a predetermined stress or more. When the pressing force acts on the elastic body, the elastic body expands and deforms in the lateral direction, and is configured to be inscribed in the cylindrical body so that the impact load can be absorbed.

[0007]

According to the present invention, when an impact load such as a drop load is applied to a cooking dish serving as a weighing dish, the impact load is transmitted by a weight transmission made of an elastic body such as a spring or rubber which can be vertically extended and contracted. Through the section
To the weight detector. Therefore, a spring or
Due to the buffering action of the elastic body such as rubber, a time delay occurs in the transmission of the impact load, and the impact load transmitted to the weight detection unit is suppressed.

Further, when a load exceeding a certain fixed load is applied, an elastic body such as a spring or rubber sandwiched between two columns inscribed in the hollow cylindrical body is compressed in the vertical direction and elastically. At the same time, the elastic body expands and deforms in the lateral direction, and is pressed against the inner surface of the hollow cylindrical body to generate a frictional force. As a result, the pressing force applied to the cooking dish due to a load equal to or more than a certain fixed load is attenuated and transmitted to the weight detecting unit. Therefore, a load equal to or more than a certain fixed load is not transmitted to the weight detection unit.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a cross-sectional view of a weight sensor mounted on a heating cooker according to the present invention. The same components as those of the conventional example are denoted by the same reference numerals. FIG. 2 shows a fixed hollow cylinder 9 having an inner diameter of 10 mm and two pillars 1 inscribed therein and sliding up and down.
A weight transmitting unit 4 comprising a coiled spring as an elastic body 12 sandwiched between the upper and lower two pillars 10 and 11; and an alumina diaphragm installed below the weight transmitting unit. 1 shows a mold weight detection unit 1. The weight detection unit 1 includes two alumina substrates 13 and 1 having a diameter of about 30 mm.
4 (plate thickness of about 0.5 mm to 0.7 mm) was used in which the periphery was fixed with an adhesive layer 15 and circular electrodes 16 and 17 were formed on the inner surface. At this time, the distance between the two circular electrodes was about 50 μm. The weight of the food 5 placed on the round plate as the weighing dish 3 is transmitted to the lower portion through the column 10, the coil spring 12, and the column 11 sequentially. This force deforms the alumina substrate 13 via the shell-shaped load point 18. Therefore, the capacitance formed by the circular electrodes 16 and 17 changes due to this deformation, and the weight of the food 5 is detected as a change in the capacitance. In this configuration
The weight detector can detect up to 10 kg
You.

With such a configuration, a load of 5 kg was repeatedly dropped from a height of 5 cm 10 times on a round plate as the weighing plate 3 to perform an impact load test. When such an impact load test was carried out using ten alumina diaphragm type weight detecting parts, the conventional example in which the load on the round plate was directly transmitted without a coil spring was about 2%. Alumina substrates 13 of the three weight detection units have bullet-shaped load points 1
Cracks started from the lower part of No. 8 and broke.

Through a coil spring as the elastic body 12,
In the case of the present invention in which the load on the round plate is transmitted to the weight detection unit 1,
No breakage of the alumina substrate 13 of the weight detector 1 was found. In this case, when a load of 5 kg was gently placed on the round plate, a coil spring having a spring constant enough to allow compression was selected and used. Also,
At this time, the lower end of the round plate and the upper end of the column 9 had not yet contacted.

In this case, the upper and lower two pillars 10 and 11 are
As shown in FIGS. 3A and 3B, it was also found that if the piston was processed into a piston shape, it could move smoothly without twisting. In the above embodiment, a coil spring was used as the elastic body 12, but as shown in FIG.
The same result as described above was obtained even when rubber 21 made of silicon, butyl, or the like having a height of about 5 to 15 mm was used.

Second Embodiment FIG. 5 shows a disc spring 22 used in place of the coil spring as the elastic body 12 used in the first embodiment. 2A is a cross-sectional view of the disc spring 22, and FIG. 2B is a plan view of the disc spring 22. For example, if the maximum allowable load of the weight detector 1 is 4 kg ,
If the maximum transmission weight of the weight transmission unit 4 is 4 kg ,
The height 23 of the disc spring 22 is compressed as the load increases,
At the same time, the outer diameter 24 of the disc spring 22 increases. At this time, if the spring constant of the disc spring 22 is selected so that the outer diameter 24 of the disc spring 22 matches the inner diameter of the hollow cylindrical portion 9 under a load of 4 kg, the outer peripheral portion of the disc spring 22 is The end of the outer diameter 24 of the disc spring 22 is pressed against the hollow cylindrical portion 9 to generate frictional force. Therefore, a load of 4 kg or more is attenuated and applied to the weight detector 1. Under these conditions,
When the impact load test performed in Example 1 was performed, no breakage of the alumina substrate 13 of the weight detector 1 was found. Further, even when the load was increased to 10 kg, no breakage of the alumina substrate 13 was observed.

Although the disc spring 22 is used in the second embodiment, a rubber 25 made of silicon or butyl is used instead of the disc spring 22 as shown in FIG. Alternatively, the rubber 25 may be compressed and deformed and expanded in the radial direction. At this time, if the elastic constant of the rubber 25 is selected so that the rubber 25 is inscribed in the hollow cylindrical portion 9 with a load of 4 kg or more, a frictional force is generated by inscribed with the load of 4 kg or more. Similar results were obtained.

Further, by interposing an elastic body 12 such as a spring or rubber between the pillars 10 and 11,
The vertical movement of the upper column body 10 can be made larger than the vertical movement of 1. That is, the electrodes 16 and 17 of the weight detection unit 1
Since the distance between them is about 50 μm, the vertical movement of the lower column 11 is about 50 μm. In this case, the vertical movement of the lower column 11 is about 50 μm, and the upper column 10
May be set to 0.5 mm. Therefore, when a load of 4 kg is applied to the round plate serving as the weighing plate 3, the elastic body 12 may be selected so that the lower end of the round plate comes into contact with the upper end of the hollow cylindrical portion of the weight transmitting unit. it can. In this case, a load of 4 kg or more is not transmitted to the weight detection unit 1 as in the above-described embodiment. Therefore, the same result as described above is obtained.

[0017]

As described above, according to the weight sensor of the present invention, the following effects can be obtained.

(1) The impact load applied to the cooking dish is suppressed and transmitted to the weight detection unit as a weight less than a certain weight , so that the weight detection unit is damaged or the weight sensor malfunctions. Disappears.

(2) Of the loads applied to the cooking dish, a load equal to or more than a certain value is not transmitted to the weight detection unit, so that the weight detection unit may be damaged or the weight sensor may malfunction. Disappears.

When such a weight sensor is used in a cooking device such as a microwave oven, a round plate as a weighing dish is usually used while rotating. According to the weight sensor of the present invention, the weight transmitting portion is provided on the upper and lower two pillars.
Since it is divided, for example, the upper column 10 can be freely rotated and moved up and down, and the lower column 11 can be made only up and down freely. That is, the relationship between the lower column 11 and the hollow cylinder 9 can be a spline bearing type. In this case, the relationship between the lower column 11 and the load point 18 is such that only the compressive force acts, and no rotational force is applied unlike the conventional weight sensor, so that the wear resistance of the rotary shaft is greatly reduced. The effect of being improved is also obtained.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a weight sensor according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view of a main part of the weight sensor.

FIG. 3 is an enlarged sectional view of a main part of another weight transmission unit of the weight sensor.

FIG. 4 is an enlarged sectional view of a main part used for another weight transmission unit of the weight sensor.

FIG. 5 is a cross-sectional view and a plan view of a disc spring used in another weight transmission unit of the weight sensor.

FIG. 6 is an enlarged sectional view of a main part of another weight transmission unit of the weight sensor.

FIG. 7 is a configuration diagram of a cooking device using a conventional weight sensor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Weight detection part 2 Cooking room 3 Weighing pan 4 Weight transmission part 5 Cooking item

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F24C 7/08 315 F24C 7/02 315 F24C 15/16 G01G 21/23 G01G 23/02

Claims (1)

(57) [Claims] 1. A weighing dish on which an object is placed, a weight transmitting section for rotatably or vertically supporting the weighing dish and transmitting the weight of the weighing dish via an elastic body which is vertically expandable and contractable; A weight detection unit that detects the weight transmitted by the weight transmission unit, wherein the weight transmission unit includes a hollow cylinder, and two vertically movable columns inscribed in the hollow cylinder and provided in the hollow cylinder. And an elastic body vertically stretchable and sandwiched between the two pillars, and the elastic body expands in the lateral direction at a pressing force of a certain stress or more and inscribes the hollow cylindrical body. Weight sensor configured.