JPH09264540A - Weight measuring device and heat-cooker having the device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent variation of precision even when an environmental change generates, and in addition, reduce the cost. SOLUTION: This weight measuring device is equipped with a loading table 1 on which an article to be measured is loaded, a first rotating body 2 being engaged with the loading table 1, a second rotating body 4 which is connected to the first rotating body 2 by an elastic member 3, a driving source 5 to drive the second rotating body 4, and a calculating means 6 which calculates a value of slipping between the first rotating body 2 and the second rotating body 4 when being driven by the driving source 5. Then, the value of the slipping is utilized for the calculation of the weight of the article.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a weight measuring device having a novel structure, and a heating cooker incorporating the weight measuring device having the novel structure.

[0002]

2. Description of the Related Art Conventionally, there is a heating cooker with a weight measuring device which measures the weight of food to be cooked and sets an optimum cooking time according to the weight. Then, as a method for measuring the weight, a piezoelectric element method in which pressure is converted into electricity by a piezo effect and converted (Japanese Patent Laid-Open No. 57-184).
No. 836, etc.), a method using an amorphous metal in which a coil is wound around an amorphous ferromagnetic core and used as a displacement transducer (Japanese Patent Publication No. 59-45089, etc.), and a semiconductor sensor system using a pressure-sensitive semiconductor (Japanese Patent Publication No. 53-3).
No. 5652, etc.), a variable capacitance method using a change in electrostatic capacity (Japanese Patent Publication No. 52-43583, etc.), a variable inductor method for detecting a change in magnetic permeability of a magnetic body with a coil, and a change in displacement amount by light Various methods such as a light detection method that emits light have been proposed.

[0003]

However, since various conventional methods use special materials and parts, the cost tends to be high. In addition, each conventional method uses a material such as a piezoelectric element, an amorphous metal, or a semiconductor sensor that is easily affected by environmental changes, and thus has a problem that the accuracy is deteriorated depending on the usage environment or long-term use. .

Further, if it is attempted to keep the cost low by using low-quality materials and parts which are low in cost, the accuracy is further lowered and it cannot be used. On the other hand, if efforts are made to respond to environmental changes, the structure becomes complicated, and moreover expensive materials and parts are used, resulting in a significant increase in cost. For this reason, the conventional heating cooker with a weight measuring device is limited to the high-class type.

It is an object of the present invention to provide a weight measuring device that does not cause a change in accuracy even if an environmental change occurs, and a heating cooker having the device.

[0006]

In order to achieve the above object, a weight measuring apparatus according to claim 1 has a mounting table on which an object whose weight is to be measured is mounted, and a first rotating member engaged with the mounting table. And a second body connected to the first rotating body via an elastic member
And a drive source for driving the second rotary body, and calculation means for calculating a deviation value between the first rotary body and the second rotary body when driven by the drive source. And is used to calculate the weight of the object.

[0007] According to the second aspect of the present invention, the first aspect is provided.
In the weight measuring device described above, a first rotating body detecting means for detecting rotation of the first rotating body and a second rotating body detecting means for detecting rotation of the second rotating body are provided as part of the deviation calculating means. The time difference between the signal from the first rotating body detecting means and the signal from the second rotating body detecting means is set as the deviation value. Further, in the invention according to claim 3, in the weight measuring apparatus according to claim 1, a first rotating body detecting means for detecting rotation of the first rotating body is provided as a part of the deviation calculating means, and the first rotating body is rotated. The time when the body starts to rotate is detected by the first rotating body detecting means, the time until the first rotating body starts to rotate after the drive source starts operating is calculated by the deviation calculating means, and the time is calculated. The value is the deviation.

Further, in the invention according to claim 4, in the weight measuring apparatus according to claim 2, the first rotating body detecting means and the second rotating body detecting means are the first rotating body and the second rotating body. The magnets are arranged respectively, and the magnetic detection means are arranged at positions facing the magnets. Further, in the invention according to claim 5, in the weight measuring apparatus according to claim 2 or 4, both signals from the first rotating body detecting means and the second rotating body detecting means are transmitted by the second rotating body at least once. Have detected after.

Further, in the invention according to claim 6, in the weight measuring device according to claim 1, 2, 3, 4 or 5,
The relative positional relationship between the first rotating body and the second rotating body when the object is not placed on the mounting table is the home position, the value of the deviation is the difference from this home position, and the first rotating body and the second rotating body are the same. The rotating body is returned to the home position by the elastic member when the object is not placed on the mounting table. Further, in the invention according to claim 7, claims 1, 2 and
In the weight measuring device described in 3, 4, 5 or 6, the drive source is a motor rotating at a constant speed, and the deviation value is the first value.
The deviation time of the rotating body from the second rotating body is set.
In addition, in the invention described in claim 8, claims 1, 2, 3,
In the weight measuring device described in 4, 5, 6 or 7, the drive source is a synchronous motor.

According to the invention of claim 9, in the weight measuring device of claim 1, 2, 3, 4, 5, 6, 7 or 8, the elastic member is a coil spring. Furthermore, in the invention described in claim 10, in the weight measuring device according to claim 9, the coil spring is constituted by a plurality of springs having different spring forces.

According to the eleventh aspect of the present invention, in the weight measuring apparatus according to the ninth or tenth aspect, the prevention wall for preventing the coil spring from tilting when the coil spring is twisted is provided with the first rotating body and the second rotating body. The coil spring is provided on at least one of the rotating bodies, and the coil spring is arranged inside or outside the prevention wall. In addition, in the invention of claim 12, claims 9 and 1
In the weight measuring device according to 0 or 11, the coil spring has fixed coil diameters at both ends, and both end portions are engaged with the first rotating body and the second rotating body.

Further, in the heating cooker according to the thirteenth aspect, the object is a food material for cooking.
The weight measuring device described in 5, 6, 7, 8, 9, 10, 11 or 12 is provided.

In this weight measuring device, when the second rotating body is rotated by a drive source such as a synchronous motor, the rotation is transmitted to the first rotating body via an elastic member such as a coil spring. Then, the mounting table rotates with the rotation of the first rotating body. At this time, as the weight of the object on the mounting table is larger, the first rotating body rotates in a state of being displaced from the second rotating body. Therefore, if the value of this deviation is detected and the relationship between the value and the weight is derived, not only the magnitude of the weight but also the weight itself can be calculated.

According to this method, since a proportional relationship is established between the shift value and the weight, the weight can be calculated with an extremely simple structure of adding an elastic member, and the cost can be reduced. Become. Also, when environmental changes occur,
The elastic member is the only member whose effect should be considered. Therefore, compared to the conventional weight measuring device in which various parts are combined, the change in accuracy is less likely to occur due to the change in environment. Furthermore, when such a weight measuring device is used in a heating cooker that requires strict temperature conditions and is also required to be small in volume, it is possible to obtain a compact cooking cooker with good cooking conditions at low cost. Becomes

Here, the elastic member may be a spring such as a torsion coil spring, rubber, or a synthetic resin having elasticity. The drive source may be a motor such as a synchronous motor or a stepping motor, as well as a mainspring or a plunger. Further, as a detection means, a non-contact type such as a mechanical means using a micro switch, a Hall IC and a magnet, a metal cam and a proximity sensor, a photo sensor, or the like is used. Detection means can be employed.

[0016]

FIG. 1 is a block diagram showing an embodiment of the present invention.
Starting from FIG. 7, description will be made. Note that the first embodiment will be described first with reference to FIGS. 1 to 4.

The first embodiment is a weight measuring device applied to a heating cooker. Then, this weight measuring device is a dish 1 serving as a mounting table on which an object whose weight is to be measured is mounted.
And a disk-synchronous rotary cam 2 that is a first rotary body that engages with the disk 1, and a motor that is a second rotary body that is connected to the disk-synchronous rotary cam 2 via a torsion coil spring 3 that is an elastic member. Synchronous rotary cam 4, synchronous motor 5 serving as a driving body for driving the motor synchronous rotary cam 4, and the synchronous motor 5
It is mainly composed of a detecting means 6 which is a part of a deviation calculating means for calculating a value of a deviation between the dish synchronous rotation cam 2 and the motor synchronous rotation cam 4 when driven by.

At the lower part of FIG. 1, there is provided a roller body 7 which supports the dish 1 and rotates together with the dish 1.
Further, while supporting the roller body 7, a range case 8 which is a frame body of the heating cooker is provided so as to surround the plate 1. Further, a fixed frame 9 to which the synchronous motor 5 and the like are attached is fixed to the range case 8. Further, a controller (not shown) for processing the signal detected by the detection means 6 is provided in the heating cooker. This control unit constitutes a part of the deviation calculating means. Then, a microcomputer in the heating cooker that controls various devices of the heating cooker may be used as the control unit.

The plate 1 is engaged with a plate synchronous rotation boss 11 fixed to the plate synchronous rotation cam 2 and rotates integrally with the plate synchronous rotation cam 2. The dish synchronous rotation cam 2 has a disc shape and has an engaging recess 12 at the center thereof.
The motor output shaft 13 of the synchronous motor 5 is rotatably loosely engaged therewith. Further, an operating portion (not shown) for generating a signal from the detecting means 6 is provided on the peripheral surface of the dish synchronous rotation cam 2, and a projection on the lower surface of which the one end portion 3a of the torsion coil spring 3 is locked. 14 are provided. The plate 1 may not rotate integrally with the plate synchronous rotation cam 2, but the plate synchronous rotation cam 2 and the roller body 7 may be fixed, and the plate 1 may be rotated together with the rotation of the roller body 7.

The torsion coil spring 3 is used for the motor output shaft 13
Are arranged so as to penetrate the center of the. The one end 3a is locked to the protrusion 14, and the other end 3b is locked to the protrusion 15 on the upper surface of the motor synchronous rotation cam 4. In this way, the torsion coil spring 3 is arranged between the dish synchronous rotation cam 2 and the motor synchronous rotation cam 4. The initial angle α between the one end portion 3a and the other end portion 3b of the torsion coil spring 3 is wide open as shown in FIG. 3 (A), and its value is 144 degrees. Further, as shown in FIG. 3, the torsion coil spring 3 has an outer diameter L1 of about 1 at the circumferential portion.
2.2mm, effective number of turns 6.6, height L2 7.7
mm. Also, this torsion coil spring 3
Made of SUS304 and annealed at low temperature,
The length L3 of each end 3a, 3b is 4 mm, and the spring material thickness L4 is 1.1 mm.

The motor synchronous rotation cam 4 has a disk shape and is fixed to the motor output shaft 13 so as to rotate integrally with the motor output shaft 13. In addition to the protrusion 15 provided on the upper surface, an operating unit (not shown) for generating a signal from the detection unit 6 is provided on the peripheral surface. The synchronous motor 5 is attached to the fixed frame 9. The motor output shaft 13 of the synchronous motor 5 has a rotation speed of 10 seconds per rotation. As this rotation speed, other rotation speeds such as one rotation in 20 seconds can be appropriately adopted.

The detecting means 6 is arranged on the side of the peripheral surface of the dish synchronous rotation cam 2 and is attached to the fixed frame 9 for the micro switch 16 for the dish rotation signal and the dish synchronous rotation cam for operating the micro switch 16. 2 motion parts,
The motor-synchronized rotary cam 4 includes a micro switch 17 for a motor rotation signal, which is arranged on the side of the peripheral surface of the motor-synchronized rotary cam 4 and is attached to the fixed frame 9, and an operating portion of the motor-synchronized rotary cam 4 for operating the micro switch 17. It
The roller body 7 is composed of a roller holder 18 and a plurality of rollers 19 held by the roller holder 18. Here, the micro switch 16 and the operating portion of the dish synchronous rotation cam 2 constitute a first rotating body detecting means, and the micro switch 17 and the operating portion of the motor synchronous rotation cam 4 form a second rotating body detecting means.
It constitutes a rotating body detecting means.

The operation of the weight measuring device constructed as described above is as follows. First, the ingredients for cooking are placed on the plate 1 serving as a placing table. Then, cooking is started. When cooking is started, the synchronous motor 5 is energized, and the motor synchronous rotation cam 4 rotates integrally with the motor output shaft 13. Then
A start signal is generated from the micro switch 17 for the motor rotation signal and is input to the control unit. On the other hand, the rotation of the motor output shaft 13 causes the motor synchronous rotation cam 4 to have the other end 3
The torsion coil spring 3 to which b is locked also tries to rotate. However, since one end 3a thereof is locked to the protrusion 14 of the dish synchronous rotation cam 2, the total weight of the weight of the dish synchronous rotation cam 2, the weight of the dish 1 and the weight of the foodstuffs is summed up. Works as a load and cannot rotate immediately.
Therefore, the torsion coil spring 3 is gradually wound and tightened. Then, when the tightening force and the total weight are balanced, the plate synchronous rotation cam 2 starts to rotate. Then
A displacement calculation signal is generated from the micro switch 16 for the dish rotation signal and is input to the control unit. The control unit obtains the time difference between the deviation calculation signal and the start signal, calculates the weight of the food from the time difference, and reflects the weight on the cooking time and the like.

That is, as shown in FIG. 4, the time difference between the deviation calculation signal and the start signal has a constant proportional relationship with the weight of the food placed on the plate 1 serving as a mounting table. Therefore, if the time difference that is the value of the shift is obtained,
The weight of the foodstuffs placed on the plate 1 is obtained from the graph shown in FIG. As a result, if the cooking time is calculated by the microcomputer or the like using the data converted into the weight or the data of the time difference itself, optimum cooking can be performed according to the weight, that is, the volume of the food. In addition,
The operating part of the pan-synchronizing rotary cam 2 and the operating part of the motor-synchronous rotary cam 4 are exactly the respective operating terminals 1 of the microswitch 16 and the microswitch 17 shown in FIG.
6a and 17a are arranged in the same positional relationship.
That is, when there is no weight at all, signals are simultaneously generated from the micro switches 16 and 17.

The graph shown in FIG. 4 shows the synchronous motor 5
When the rotation takes 1 second and takes 10 seconds, the graph corresponds to the difference of 2.8 seconds when the deviation angle is 100 degrees. Also, this graph is obtained by measuring three times in succession, and the average variation is about 5%. Further, in the actual measurement and signal processing in this embodiment, a start signal and a deviation calculation signal after a lapse of a fixed time (about 10 seconds) in which initial information at the start of rotation of the dish 1 does not enter are used. This is because the dish synchronous rotation cam 2 and the motor synchronous rotation cam 4 continue to rotate with a constant deviation after the initial inertia is removed. Also, as shown in FIG.
Even when the food material is not placed on the plate 1, a deviation value of about 0.67 seconds is generated. This is due to the weight of the plate 1 and the plate synchronous rotation cam 2 and the like. Then, the relative positional relationship between the dish synchronous rotation cam 2 and the motor synchronous rotation cam 4 when no food material is placed is the home position. The opening angle β of the torsion coil spring 3 at the home position is initially about 120 degrees in this embodiment. Here, the opening angle β at the home position changes depending on how dirty the roller 19 is, the change over time of the coil spring 3, and the like. After the cooking is finished, when the cooked food is taken out, the dish 1 or the dish synchronous rotation cam 2 is solenoided (not shown) at the end of the cooking so that the dish 1 does not rapidly rotate due to the returning force of the torsion coil spring 3. I'm trying to hold it. Then, after the food is taken out, the synchronous motor 5 is chopped, that is, the drive current is made to flow at a constant interval for a short time, and the relationship between the plate synchronous rotation cam 2 and the motor synchronous rotation cam 4 is set at the home position. Returning to a relationship.

In this embodiment, even if the food is contaminated between the roller 19 and the range case 8 and a catch occurs, it can be detected any number of times during the rotation, and accurate data can be obtained. can get. In addition, in this embodiment, since the synchronous motor 5 is a motor that rotates at a constant speed with no rotation deviation, the deviation value can be extracted as a time difference. Further, since the weight of the dish 1 and the food material is not supported by the weight measuring device and the range case 8 receives the weight through the roller body 7, the weight measuring portion is lightweight and downsized. Instead of converting the deviation angle into a time difference, the deviation angle itself may be detected by a photosensor or the like and the angle may be converted into weight. Further, the solenoid for holding the plate 1 or the plate synchronous rotation cam 2 at the end of cooking and the chopping drive after taking out the food are not always necessary, and can be appropriately omitted according to the specifications.

Next, a second embodiment, which is a slight modification of the first embodiment, will be described with reference to FIG. In addition,
5, the same members as those shown in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted. In the second embodiment, the microswitches 16 and 17 of the first embodiment are used.
While the Hall ICs 21 and 22 and the magnets 23 and 24 are used, the positions of both cams 2 and 4 are detected. That is, as shown in FIG. 5, the substrate 20 is provided between the dish synchronous rotation cam 2 and the motor synchronous rotation cam 4, and the Hall ICs 21 for the dish rotation signal are respectively provided at the back-to-back positions on the respective surfaces of the substrate 20. The Hall IC 22 for the motor rotation signal is fixed. Here, the substrate 20
The Hall ICs 21 and 22 that are attached to the fixed portion of the range case 8 or the like and fixed to the substrate 20 are fixed to the fixed portion of the heating cooker. Further, on the surface of the plate synchronous rotation cam 2 on the plate 1 side, a magnet 2 for a plate rotation signal is provided.
3 is embedded. Further, on the surface of the motor synchronous rotation cam 4 on the substrate 20 side, a magnet 24 for a motor rotation signal is provided.
Is placed and fixed. In this way, the magnets 23, 2
This is because the arrangement of 4 is an asymmetric structure to avoid mutual interference of magnetic forces. Further, the plate synchronous rotation cam 2 has a boss portion 2
a, the cylindrical boss portion 4 of the motor synchronous rotation cam 4 is provided.
It has entered a. The torsion coil spring 3 is arranged between the boss portion 2a and the boss portion 4a. The Hall ICs 21 and 22 and the magnets 23 and 24
The mounting position of the micro switch 16 shown in FIG.
Alternatively, the positions may be separated by a predetermined angle, such as 17.

In the second embodiment, since signals are generated in the Hall ICs 21 and 22 by rotation of the dish synchronous rotation cam 2 and the motor synchronous rotation cam 4 in a fixed direction, the Hall IC 2
It is not affected by the variations in the sensitivity of Nos. 1 and 22 and the variations in the hysteresis when the signal rises and falls. Therefore, the Hall ICs 21 and 22 can be used for accurate detection. Further, in addition to the merits of the first embodiment described above, the second embodiment can increase the longevity of the non-contact switch. As such a non-contact switch, other methods such as a method using a metal cam and a proximity sensor and a method of light detection using a photo sensor can be adopted.

Next, a third embodiment of the present invention will be described with reference to FIG. In the third embodiment, the number of signal extraction units of the first and second embodiments is one. That is, the motor synchronous rotation cam 4 and the micro switch 17 for the motor rotation signal in the first embodiment are removed, and the motor synchronous rotation cam 4, the Hall IC 22 and the magnet 24 in the second embodiment are removed. It was also removed. In addition, in the first embodiment, the motor synchronous rotation cam 4 is the second rotating body, and in the third embodiment, the motor rotating shaft 13 is the second rotating body. .

As shown in FIG. 6, the circuit configuration of the third embodiment is provided with a switch section 30 corresponding to the micro switch 16 of the first embodiment, and the normally closed terminal 31 of the switch section 30 is provided. The resistor 32 is connected to. On the other hand, a wire having no resistance is connected in parallel with the resistance 32 to the normally open terminal 33 of the switch unit 30. Then, the synchronous motor 5 is connected between the AC power supply AC and the resistor 32.

The operation of the third embodiment configured as described above is as follows. First, the load curve (tilt angle) of FIG. 4 is stored in a control unit such as a microcomputer. After that, when cooking is started and the AC power supply AC is turned on, the AC power supply is supplied to the synchronous motor 5 via the normally closed terminal 31, and the synchronous motor 5 rotates. At this time, the voltage across the resistor 32 is a predetermined value V volt.
After that, when the spring force of the torsion coil spring 3 and the total weight such as the weight of the food are balanced, the dish synchronous rotation cam 2 starts to rotate. Then, at that point, the switching terminal 3a of the switch unit 30 is switched to the normally open terminal 33. Therefore, the AC power supply AC starts to be supplied to the synchronous motor 5 through a route that does not pass through the resistor 32. As a result, the voltage across resistor 32 drops close to 0 volts. On the other hand, the control unit constituting the deviation calculating means detects the voltage across the resistor 32, and calculates the time from the start of rotation of the synchronous motor to the time when the voltage decreases to 0 V, that is, the deviation time. Then, a control unit in the heating cooker, for example, a microcomputer calculates the weight of the food from the time difference and controls the cooking time to perform cooking.

When the cooking is completed, the dish synchronous rotation cam 2 or the dish 1 is held by a solenoid (not shown) to prevent them from rotating. Then, the door (not shown) of the cooking chamber is opened, and the cooked ingredients are removed from the plate 1. After that, close the door of the kitchen. Then, after turning off the light in the cooking chamber, the AC power supply AC is applied to the synchronous motor 5 for a minute time. By this chopping drive, the dish 1 is returned to the home position. By this return to the home position, the dish synchronous rotation cam 2 is arranged at the position immediately before the switching terminal 30a is switched from the normally closed terminal 31 to the normally open terminal 33. Therefore, in the operation of the switch unit 30 after the second time, when the food is not placed, the switching terminal 30a is changed from the normally closed terminal 31 to the normally open terminal 3 at the same time when the synchronous motor 5 starts rotating.
Switch to 3. That is, the graph of the relationship between the weight and the time difference after the second time is a graph in which the position of the horizontal axis in the graph shown in FIG. 4 is moved in the positive direction by 0.67 seconds. It should be noted that when the load loss is large due to dirt or the like on the roller 19, the position of the horizontal axis further moves in the plus direction, and the vertical axis also moves in the plus direction so that the intersection becomes zero.

In the third embodiment, the number of parts is reduced, accuracy changes due to variations in parts are reduced, and cost reduction is achieved. The switch unit 30 may use the Hall IC 21 as in the second embodiment instead of the micro switch. in this case,
When the magnet 23 and the Hall IC 21 face each other,
Power is supplied to the resistor 32, and the magnet 2
It is necessary to have a circuit configuration in which power is not supplied to the resistor 32 when 3 is separated from the Hall IC 21. Also,
In the third embodiment, it is necessary to return to the home position, but it is not always necessary to hold the dish 1 or the like with a solenoid or the like.

Next, a fourth embodiment of the present invention will be described with reference to FIG. In this fourth embodiment,
In order to improve the measurement accuracy, multiple springs with different spring forces or one spring with multiple elastic constants can be used.
The low load spring part supports measurement of parts with low weight,
The high load spring part is used for the measurement of a heavy part. The fourth embodiment is different from the first to third embodiments only in the configuration of the elastic member as described above, and other configurations are the same as those in the first, second or third embodiment. It is similar to the form. Further, in the fourth embodiment, two springs are used or one spring having two different spring force portions is used, but three or more springs are used, or three or more different spring forces are used. It may be one spring.

That is, the first to third embodiments are 0
While the food material weighing up to about 5 kg was measured with one torsion coil spring 3 having a constant elastic constant,
In the first example shown in FIG. 7 (A) of the fourth embodiment, a torsion coil spring 41 having a low spring force for weak load corresponds to a deviation angle of 0 to 90 degrees, and 90 degrees to 300 degrees. A torsion coil spring 42 having a high spring force for high load is used. That is, the second rotating body 43 is provided with the pin 44, and the pin 44 initially tightens the low load torsion coil spring 41 by 90 degrees. After that, the high load torsion coil spring 42 is wound tightly, and the torque is transmitted to the first rotating body (not shown).

Further, as in the second example of the fourth embodiment shown in FIG. 7B, the second rotor 43 and the intermediate rotor 4 are provided.
5, a low load torsion coil spring 46 having weak elasticity may be provided, and a high load torsion coil spring 48 having strong elasticity may be provided between the intermediate rotating body 45 and the first rotating body 47. good. Further, in the third example of the fourth embodiment shown in FIG. 7C, one torsion coil spring 49 is replaced by a weak spring portion 49a having a large diameter and a strong spring portion 4 having a small diameter.
It is divided into 9b. At the center of the torsion coil spring 49, there is provided an inner shaft 50 for suppressing the inclination of the torsion coil spring 49. The portion of the inner shaft 50 around which the weak spring portion 49a is wound has a large diameter, and the portion around which the strong spring portion 49b is wound has a small diameter.

Further, in the fourth example of the fourth embodiment shown in FIG. 7D, a weak compression spring 51 and a strong compression spring 52 are provided.
I use. That is, the weak compression spring 51 is provided on the protrusion 54 projecting outward of the second rotary body 53, and the weak compression spring 51 is compressed in the initial rotation, and then the weak compression spring 51 and the first rotary body 53 are compressed. The strong compression spring 52 provided between the projection 55 projecting toward the shaft center of 55 is compressed. In addition, as a modification, a fifth example shown in FIG.
As in the example of FIG.
And both protrusions 60 protruding toward the axial center of the first rotating body 59,
Two compression coil springs 61, 61 symmetrically with 60
Is provided. Then, the compression coil springs 61, 61
Are weak spring portions 61a and 6 having weak elastic forces.
1a and strong spring portions 61b, 61b having strong elastic force
And Also in this fifth example, the second rotating body 57
When the drive source is rotated, first, the weak spring portion 61
a and 61a are crushed. When the weight of the food is large, the strong spring portions 61b and 61b are crushed thereafter. In this way, the torque is transmitted to the first rotating body 57.

Next, a description will be given of a fifth embodiment in which the problems caused when the torsion coil springs 3, 41, 42, 46, 48 and 49 of the first to fourth embodiments are used are improved. For example, as shown in FIG. 8A, when one end 3a of the torsion coil spring 3 is engaged with the first rotating body 2 and the other end 3b is engaged with the second rotating body 4, The second rotating body 4 is rotated in the direction of arrow A. Then, the one end 3a of the torsion coil spring 3 tries to rotate the first rotating body 2,
Since the first rotating body 2 is heavy, the torsion coil spring 3 tilts as shown in FIG. 8 (A). For this reason,
The root portion of the torsion coil spring 3 on the second rotating body 4 side is
It hits the motor rotating shaft 13 and turns around while being rubbed. As a result, the motor rotating shaft 13 has a recess 13a as shown in FIG. When the concave portion 13a is formed, the torsion coil spring 3 further tilts, the position of the other end portion 3b changes, and further, the contact state of the torsion coil spring 3 becomes unstable, and the measured data varies. This variation becomes a large ratio in a portion where the weight is small, that is, in a low load range, and poses a problem.

As a countermeasure against such a problem at the time of using the torsion coil spring, in the fifth embodiment, as shown in FIG. 9, a second cylindrical prevention wall 71 for preventing the torsion coil spring 70 from tilting is provided. It is provided on the rotating body 72 and its prevention wall 71
A torsion coil spring 70 is inserted in the inside of the. The torsion coil spring 70 is a twist coil spring 70 devised to prevent wear of the motor rotating shaft 13 and the like.
That is, as shown in FIG. 9A, the difference X between the inner diameter of the prevention wall 71 and the outer diameter of the torsion coil spring 70 is set to almost zero, while the inner diameter of the torsion coil spring 70 and the shaft portion of the first rotating body 73. The difference Y from the outer diameter of 74 is equal to or more than the spring contraction amount, that is, the contraction amount when it is wound. The shaft portion 74 has a recess at the center thereof, and the projection shaft 75 of the second rotating body 72 is rotatably fitted in the recess. In addition, in the fifth embodiment, both ends 70a and 70b of the torsion coil spring 70 are not bent at right angles used in the torsion coil spring 70 shown in FIG. I am trying.
This is because in the torsion coil spring 76 as shown in FIG. 9B, the portion bent at a right angle (arrow B) becomes weak and is easily damaged.

Due to this structure, both ends 70 of the torsion coil spring 70 are operated at a low load with a small amount of compression.
The winding portions at the roots of the a and 70b come into contact with the upper and lower two locations on the inner side surface of the prevention wall 71, and the inclination of the torsion coil spring 70 is prevented. On the other hand, when the compression amount is high and the load is high, the torsion coil spring 70 is wound around the shaft portion 74, so that the inclination thereof is prevented.

FIG. 10 is a graph showing the relationship between the weight of the food material and the time difference in the fifth embodiment described above. This graph corresponds to the graph in FIG. However, different points exist as follows. In the graph of FIG. 4, the torsion coil spring 3 having an inner diameter of 10 mm is arranged around the motor rotating shaft 13 having a diameter of 7 mm. However, in the graph of FIG. 10, as shown in FIG. A shaft portion 74 having a diameter of 9.2 mm is provided on the dish synchronous rotation cam 73, and the torsion coil spring 70 having the shape shown in FIG. 3 and an inner diameter of 10 mm is arranged around the shaft portion 74.
In addition, the prevention wall 71 is provided. As shown in the graph of FIG. 10, in the case where the prevention wall 71 and the like are provided, the variation is reduced, and particularly the variation on the low load side is reduced, and the linearity (proportionality) of the whole is reduced. Has improved. In addition, the large amount of wear iron powder generated in the device that does not take this measure is not generated in the device of the fifth embodiment.

As another means for solving the above-mentioned problem when the torsion coil spring is adopted, the torsion coil spring 80 of the sixth embodiment shown in FIG. 11 may be adopted. As shown in FIG. 11 (A), the torsion coil spring 80 has both ends 80a and 80b in a hook shape, and has a diameter r from the center of each of the ends 80a and 80b.
₁ and r ₂ are not changed. That is, when it is wound tightly, as shown in FIG. 11 (B), the diameter of the central portion becomes smaller than the diameters of both ends to form a drum shape. Such a torsion coil spring 80 is attached as shown in FIG. One end 8 of the torsion coil spring 80
0a is engaged with the protrusion 82 of the first rotating body 81, and the other end 80b is engaged with the protrusion 84 of the second rotating body 83. The shaft portion 85 of the first rotating body 81 is provided with a recess, and the shaft portion 86 of the second rotating body 83 is rotatably fitted in the recess. By using such a torsion coil spring 80, the winding portions at the bases of the both end portions 80a and 80b do not come into contact with the shaft portion 85, and the recessed portion 13a as shown in FIG. 8B does not occur in the shaft portion 85. Becomes In the sixth embodiment as well, similar to the graph of FIG. 10, there is little variation, and in particular, there is little variation on the low load side and good overall linearity is obtained.

Next, the weight measuring device is flattened in the seventh
The embodiment will be described with reference to FIG. The weight measuring apparatus according to the seventh embodiment uses Hall ICs 21 and 22 as in the second embodiment shown in FIG. 5, except for the arrangement of the synchronous motor 5 and the synchronous motor 5.
It is a method of transmitting torque from. In the seventh embodiment, the synchronous motor 5 is arranged in parallel on the same space where the dish synchronous rotation cam 2 and the motor synchronous rotation cam 4 are arranged. Moreover, the rotation of the synchronous motor 5 is changed from the gear 90 fixed to the motor output shaft 5a to the gear 90
Gear portion 9 provided on the motor synchronous rotation cam 4 that meshes with the
I'm telling 1. The dish synchronous rotation cam 2 and the motor synchronous rotation cam 4 are both fixed to a fixed frame 9 and rotatably held by a fixed shaft 92. Further, the dish synchronous rotation cam 2 is provided with a boss portion 2 a, which is inserted into the cylindrical boss portion 4 a of the motor synchronous rotation cam 4. The torsion coil spring 3 is arranged between the boss portion 2a and the boss portion 4a.

In case of using only one Hall IC, as shown in FIG.
A structure as shown in 3 can be adopted. This figure 1
The deviation calculating means of the weight measuring device according to the eighth exemplary embodiment shown in FIG. 3 mainly includes a Hall IC 93, a magnet 94 attached to the dish synchronous rotation cam 2, and a magnet 95 attached to the motor synchronous rotation cam 4. Is composed of. The magnet 94 and the magnet 95 are shown in FIG.
As shown in (A), the Hall IC 93 is attached so that its polarities are reversed.

Then, as shown in FIG. 13B, first, the angle θ1 between the magnets 94 and 95, that is, the deviation time, is measured at the initial stage of no load. Then, the foodstuff is placed and the deviation angle θ2, that is, the deviation time is measured. Then, the shift time due to the weight of the food material is calculated by subtracting the angle θ1 from the angle θ2. Since the magnets 94 and 95 are attached in the opposite direction, the hole I
Both signals entering C93 can be determined by "rising" and "falling". Therefore, it is possible to determine whether the signal entering the Hall IC 93 is the signal of the dish synchronous rotation cam 2 or the signal of the motor synchronous rotation cam 4, and the shift time can be easily calculated.

The above-described embodiments are examples of preferred embodiments of the present invention, but the present invention is not limited to these, and various modifications can be made without departing from the gist of the present invention. Is. For example, the first rotating body and the mounting table 1 of each embodiment are integrated, and the first rotating body is mounted on the mounting table 1
You may make it double as. Furthermore, in all the embodiments, the value of the deviation of the first rotating body from the second rotating body may be regarded as an angle instead of a time difference. In addition, as a method of capturing the angle difference, one of the first rotating body and the second rotating body is provided with an MR.
There is a method in which a magnetic element is arranged on one of the elements and the number of magnetic poles of the magnetic substance is calculated by an MR element. Further, the motor rotary shaft 13 around which the torsion coil spring 3 and the like are wound may be a shaft-shaped member that rotates integrally with the motor rotary shaft 13.

Further, as the elastic member, in addition to the spring such as the torsion coil spring 3 and the compression spring, rubber or synthetic resin having elasticity may be used. Further, as the drive source, other than the synchronous motor 5, a motor such as a stepping motor or a DC motor or a motor such as a mainspring or a plunger may be used. If the driving source is a synchronous motor 5, a stepping motor, or the like having a constant relationship between time and rotation speed, the time difference can be used as a substitute for the deviation value. on the other hand,
If the rotation speed of the DC motor or the like is unlikely to have a constant relationship, it is preferable to detect the deviation angle itself without using the deviation value as a time difference. Further, as the detecting means, the micro switches 16 and 17 and the Hall ICs 21 and 2 are used.
In addition to 2, various other detecting means such as a photo sensor or a metal cam and proximity sensor may be used.

[0048]

As described above, in the weight measuring apparatus according to the first aspect, since the weight can be measured only by adding the elastic member and the deviation calculating means, the accuracy change due to the environmental change is small. Will be things. Further, in this weight measuring device, since the members that are added to the mechanism that does not measure the weight are mainly the elastic member and the deviation calculating means, the additional function of the weight measuring can be realized at low cost.

According to the second aspect of the invention, since the deviation value is the time difference between the signals from the two detecting means,
The deviation value can be easily detected. Furthermore, in the invention according to the third aspect, since only one detecting means is provided, cost reduction and accuracy stabilization can be achieved.

Furthermore, in the invention according to the fourth aspect, since the non-contact method utilizing magnetism is used, the life of the detecting operation can be extended. Further, in the invention according to claim 5, since the signal is detected after the second rotating body has made at least one rotation, that is, the signal after the rotation has been stabilized is utilized, so that it is stable and accurate. A signal can be obtained, and the accuracy of weight calculation can be improved.

According to the sixth aspect of the invention, when there is no object on the mounting table, both rotating bodies are returned to their home positions, so that the weight can be measured again smoothly. In addition, in the invention according to claim 7, since the drive source is a motor that rotates at a constant speed, the angle of deviation between the two rotating bodies can be calculated as the deviation time, and the signal can be detected easily. Further, according to the invention described in claim 8, since the synchronous motor is used as the drive source, stable constant speed rotation can be easily obtained.

Further, in the invention according to claim 9, since the elastic member is the coil spring, the cost can be reduced and the quality can be stabilized. Further, according to the tenth aspect of the present invention, since a plurality of coil springs having different spring forces are used, a low load, that is, a small weight can be measured with a coil spring having a weak spring force, and the measurement accuracy is improved.

Further, in the inventions according to the eleventh and twelfth aspects, since measures such as inclination prevention of the coil spring are taken,
Both ends of the coil spring do not wear the member supporting the coil spring. As a result, the measurement accuracy is improved and no abrasion powder is generated.

In the heating cooker according to the thirteenth aspect,
The quality is stable, and the weight measuring device has a small size at a low cost. For this reason, it is possible to provide a heating cooker that is small in size and low in price and capable of performing accurate cooking suitable for the weight of food.

[Brief description of drawings]

FIG. 1 is a side view of a first embodiment of the present invention.

FIG. 2 is a plan view of a main part of FIG.

3A and 3B are views showing a torsion coil spring used in the weight measuring device of FIG. 1, in which FIG. 3A is a front view and FIG. 3B is a side view seen from the left of FIG.

FIG. 4 is a graph showing the relationship between the weight of foodstuffs and the shift time when the foodstuffs are placed on the weight measuring device of FIG. 1.

FIG. 5 is a partial cross-sectional side view of the right half of the second embodiment of the present invention, which is a view corresponding to the right half of FIG.

FIG. 6 is a circuit diagram of a third embodiment of the present invention.

FIG. 7 is a diagram showing a fourth embodiment of the present invention, showing a modified example of the elastic member in the first to third embodiments, where (A) shows the first example and (B) shows ) Is the second example,
(C) shows the third example, (D) shows the fourth example, and (E) shows the fifth example.

FIG. 8 is a diagram for explaining a problem when a coil spring is used in the first to fourth embodiments of the present invention, FIG.
FIG. 4B is a schematic view of the vicinity of a coil spring, and FIG. 6B is a view showing that a recess is formed in a motor rotation shaft or a boss portion.

9A and 9B are schematic views of an elastic member and its periphery according to a fifth embodiment of the present invention, FIG. 9A is a sectional view thereof, and FIG. 9B is another coil spring for explaining a difference from the coil spring of FIG. FIG.

FIG. 10 is a graph showing the relationship between the weight of foodstuffs placed on the weight measuring device of FIG. 9 and the shift time.

11A and 11B are views showing an elastic member according to a sixth embodiment of the present invention, in which FIG. 11A is a front view thereof, FIG. It is a schematic sectional drawing which shows the state which attached the elastic member of A).

FIG. 12 is a partial cross-sectional side view of the left half of the seventh embodiment of the present invention, corresponding to the left half of FIG.

FIG. 13 is a diagram showing an eighth embodiment of the present invention,
(A) is a main part conceptual diagram, (B) is a figure which shows a gap | deviation at the time of no load, (C) is a figure which shows a gap | deviation when a foodstuff is put.

[Explanation of symbols]

 1 Dish 1 (Mounting Table) 2 Dish Synchronous Rotation Cam (First Rotating Body) 3 Torsional Coil Spring (Elastic Member) 4 Motor Synchronous Rotating Cam (Second Rotating Body) 5 Synchronous Motor (Drive Source) 6 Detecting Means (Displacement) (Part of calculation method)

Claims (13)

[Claims] 1. A mounting table on which an object whose weight is to be measured is mounted, a first rotating body engaged with the mounting table, and a second rotating body connected to the first rotating body via an elastic member. Body and the second
And a deviation calculating means for calculating a deviation value of the first rotating body with respect to the second rotating body when driven by the driving source. Is used for calculating the weight of the object. 2. A first detecting the rotation of the first rotating body
A rotating body detecting means and a second rotating body detecting means for detecting the rotation of the second rotating body are provided as part of the deviation calculating means, and a signal from the first rotating body detecting means and the second rotation are provided. The weight measuring device according to claim 1, wherein a time difference from a signal from the detecting means is set as the value of the deviation. 3. A first detecting the rotation of the first rotating body
A rotating body detecting means is provided as a part of the deviation calculating means,
When the first rotation detecting means detects the time when the first rotating body starts to rotate, and after the drive source starts operating, the time until the first rotating body starts to rotate is calculated as the deviation. 2. The weight measuring device according to claim 1, wherein the time is calculated by means and the time is set as the value of the deviation. 4. The first rotating body detecting means and the second rotating body detecting means.
The rotating body detecting means is configured such that magnets are arranged in the first rotating body and the second rotating body, respectively, and magnetic detecting means is arranged in positions facing the magnets. 2. The weight measuring device according to 2. 5. The two signals from the first rotation detecting means and the second rotation detecting means are detected after the second rotating body has made at least one rotation, and 4. The weight measuring device according to 4. 6. A home position is defined as a relative positional relationship between the first rotating body and the second rotating body when an object is not placed on the mounting table, and a value of the deviation is defined as a difference from the home position. The first rotating body and the second rotating body are returned to the home position by the elastic member when an object is not placed on the mounting table. 4. The weight measuring device according to 4 or 5. 7. The drive source is a motor that rotates at a constant speed, and the deviation value is a deviation time between the first rotating body and the second rotating body. ,
The weight measuring device according to 2, 3, 4, 5 or 6. 8. The weight measuring device according to claim 1, wherein the drive source is a synchronous motor. 9. The elastic member is a coil spring, and the elastic member is a coil spring.
The described weight measuring device. 10. The coil spring is composed of a plurality of springs having different spring forces.
The described weight measuring device. 11. A prevention wall for preventing inclination of the coil spring when the coil spring is twisted is provided on at least one of the first rotating body and the second rotating body, and the inside or outside of the prevention wall is provided. The weight measuring device according to claim 9 or 10, wherein the coil spring is arranged on one side. 12. The coil spring, wherein coil diameters at both ends are fixed, and both ends are engaged with the first rotating body and the second rotating body.
10. The weight measuring device according to 10 or 11. 13. The weight measuring device according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12, wherein the object is a food material for cooking. Cooker to cook.