JPH11183238A - Load cell scale - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a load cell sale which can measure the weights of a wide range of loads from a small load to a large load and can stably measure the weights of loads at or near the boundary between small loads and large loads. SOLUTION: The load cell scale is provided with a load cell 15 in which a plurality of strain generating sections 16 and 17 having different rated loads are formed, small and large-load transmitting shafts 19 and 20 respectively fixed to the loading points 17a and 16a for the strain generating sections 17 and 16 having the smaller and larger rated loads, and small and large-load pan stop frames 22 and 21 respectively fixed to the tops of the shafts 19 and 20. The load cell scale is also provided with a weighting pan 24 on which an object to be weighted is placed, magnetic force generating bodies 23 fixed to the small-load pan stop frame 22 or weighting pan 24, and attracted bodies 26 which are fixed to the pan 24 or frame 22 so that the bodies 26 may be attracted to and separated from the magnetic force generating bodies 23. The strain generating sections 16 and 17 are switched to each other, by attracting and separating the attracted bodies 26 to and from the magnetic force generating bodies 23 when a load is impressed upon one of the sections 16 and 17.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a load cell balance capable of performing high-precision weighing in a wide range from a small load to a large load.

[0002]

2. Description of the Related Art A load cell scale used for business use or the like is determined by a measuring method so that a value of a measuring accuracy is 1/3000 or less. The details of the measurement accuracy will be described with reference to FIG. FIG. 3A is a graph showing an allowable error range in a load cell weigher having a rated load of 3 kg. The allowable range of the weighing error is shown by a step-like solid line, and the actual weighing result is shown by an arc-shaped dashed line. FIG. 4B is a graph showing an allowable error range in a load cell weigher having a rated load of 30 kg. The allowable range of the weighing error is shown by a step-like solid line, and the actual weighing result is shown by an arc-shaped dashed line. In the load cell scale with a rated load of 3 kg shown in FIG.
It is within 1 g, which indicates that the load cell scale has a weighing accuracy of 1/3000. In the load cell scale with a rated load of 30 kg shown in FIG.
The error of the weighing range is within ± 10 g,
The load cell scale has a weighing accuracy of 1/3000.

[0003] Here, when a light weight object is weighed with a load cell weigher having a rated load of 30 kg, for example, a weighing error when weighing a 3 kg weighed object is about ± 2.5 g, and the weighing accuracy is reduced. In other words, in a load cell scale having a large rated load, even if the load cell scale satisfies the measurement accuracy specified by the measurement method, the measurement accuracy when weighing a lightweight object is low. With a load cell scale having a structure, it is difficult to perform highly accurate weighing in a wide range from a small load to a large load.

FIG. 9 shows a known load cell balance capable of performing high-precision weighing in a wide range from a small load to a large load. The load cell 1 of the load cell scale has a strain generating portion 2 having a large rated load and a strain generating portion 3 having a small rated load, and has a structure in which two load cells are integrated. The load cell 1 is accommodated in an accommodation space surrounded by a weighing base 4 and a weighing case 5, and the lower end of the load cell 1 on the side where the strain-generating portion 2 is formed is weighed via a mounting table 6. Base 4
It is fixed to.

[0005] On the upper surface of the load cell 1, a load transmitting shaft 7 located at the end on the side of the strain-generating portion 3 for applying a small load to the strain-generating portion 3 and two strain-generating portions 2, 3 And a load transmitting shaft 8 for applying a large load to the strain-generating portion 3 is fixed at a substantially central portion. One end of a plate receiving frame 9 is fixed to the upper end of the load transmitting shaft 7, and a plate supporting shaft 10 is attached to the other end of the plate receiving frame 9, between the plate supporting shaft 10 and the load transmitting shaft 8. Has a gap of a predetermined size "M" when not weighing.

A lower end of a dish support shaft 11 is fixed to a substantially central portion of the upper surface of the dish receiving frame 9. The pan support shaft 11 extends upward through the weighing case 5, and a weighing pan 12 is fixed to an upper end thereof.

Here, a case where a weighing object is placed on the weighing pan 12 and weighing is performed will be described. When the load of the weighing object is equal to or less than the predetermined value, the load of the weighing object is applied to the strain generating unit 3 via the plate support shaft 11, the plate receiving frame 9, and the load transmission shaft 7, and the strain of the strain generating unit 3 is changed. Metering is performed according to the quantity.

In the case where the load of the sample is applied to the strain-generating section 3 for measurement, the plate receiving frame 9 is bent as the load of the sample increases, and the lower end of the plate support shaft 10 is bent. It approaches the upper end of the load transmission shaft 8. Then, when the load of the weighed object reaches a predetermined value, the lower end of the dish support shaft 10 comes into contact with the upper end of the load transmission shaft 8. After the lower end of the plate support shaft 10 comes into contact with the upper end of the load transmission shaft 8, no more load is applied to the strain generating unit 3, and the load of the weighing object is reduced by the plate support shaft 11 and the plate receiving frame 9. The strain is applied to the strain-generating unit 2 via the load transmission shaft 8, and the measurement is performed according to the strain amount of the strain-generating unit 2.

In this way, when the load of the weighing object is small, the load is applied to the strain generating portion 3 having a small rated load to perform the weighing, and when the load of the weighing object is large, the load is increased. Since the measurement is performed by applying the load to the strain generating portion 2, highly accurate measurement can be performed in a wide range from a small load to a large load. In addition, the strain generating portion 3 having a large load and a small rated load.
, And the strain generating portion 3 is protected.

[0010]

However, in the vicinity of the boundary between the weighing range of the strain-generating portion 3 and the weighing range of the strain-generating portion 2, vibration or the like is transmitted from the outside to the load cell scale. And the lower end of the dish support shaft 10 repeatedly contacts and separates from the upper end of the load transmission shaft 8, and the measured value may become unstable.

Accordingly, the present invention switches the load of a weighing object from a small load to a large load by switching the load to be applied to a strain-generating portion having a large rated load or a strain-generating portion having a small rated load according to the load. It is an object of the present invention to provide a load cell weigher capable of performing high-precision weighing in a wide range, and stably weighing a load near a switching range.

[0012]

According to a first aspect of the present invention, there is provided a load cell scale which is fixed to a load cell having a plurality of strain generating portions having different rated loads and a load point for the strain generating portion having a small rated load. A small load transmitting shaft, a large load transmitting shaft fixed to a load point for the strain generating portion having a large rated load, a small load pan receiving frame fixed above the small load transmitting shaft, and the large load transmitting shaft. A large load pan receiving frame fixed to the upper part of the shaft, a weighing pan on which the weighing object is placed, a magnetic force generator fixed to the small load pan receiving frame or the weighing pan, and the weighing pan or the small pan; An adsorbent fixed to a load receiving frame and arranged so as to come into contact with and separate from the magnetic force generator; and when the load on the weighing object placed on the weighing pan is equal to or less than a predetermined value, the magnetic force generator And the adsorbent are adsorbed The weighing pan and the small load pan receiving frame are connected to each other, and the load of the weighing object is applied to the strain generating portion having a small rated load via the small load pan receiving frame and the small load transmission shaft. When the load on the weighing object placed on the weighing pan is equal to or greater than a predetermined value, the magnetic force generator and the adsorbent are separated from each other, and the weighing pan and the large load pan receiving frame are connected to each other. Is applied to the strain-generating portion having a large rated load via the large-load dish receiving frame and the large-load transmission shaft.

Therefore, when the load of the weighing object placed on the weighing pan is equal to or less than the predetermined value, the weighing pan and the small load pan receiving frame are connected by attracting the magnetic force generator and the adsorbent, The load of the weighed object is applied to the load point on the strain-generating portion having a small rated load via the small-load dish receiving frame and the small-load transmission shaft, and weighing is performed in accordance with the strain amount of the strain-generating portion. On the other hand, when the load of the weighing object placed on the weighing pan exceeds a predetermined value, the load exceeds the attraction force between the magnetic generator and the adsorbent, and the magnetic generator and the adsorbent are separated and the weighing pan and The large load pan receiving frame is connected. For this reason, the load of the weighing object is applied to the load point for the strain-generating portion having the large rated load via the large-load pan support frame and the large-load transmission shaft, and weighing is performed in accordance with the strain amount of the strain-generating portion. Will be Switching between the measurement performed by applying a load to the strain generating portion having a small rated load and the measurement performed by applying a load to the strain generating portion having a large rated load is performed by adsorption and separation of the magnetic force generator and the adsorbent. . For this reason, even when vibration is transmitted from the outside to the load cell scale during weighing, there is a difference between weighing performed by applying a load to the strain-generating part having a small rated load and weighing performed by applying a load to the strain-generating part having a large rated load. Switching does not occur repeatedly, and stable weighing can be performed.

According to a second aspect of the present invention, in the load cell scale according to the first aspect of the present invention, the gap between the magnetic force generator and the adsorbent in the separated state and the action between the magnetic force generator and the adsorber are provided. The magnetic force was set so that the magnetic force generator and the adsorber in the separated state were automatically attracted when the load acting on the weighing pan became a predetermined value or less.

Accordingly, it is not necessary to perform an operation of returning the separated magnetic force generator and the adsorbent to the adsorbed state, and the handleability of the load cell scale is improved.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A load cell scale according to a first embodiment of the present invention will be described with reference to FIGS. In this load cell scale, a rectangular parallelepiped load cell 15 is stored in a storage space surrounded by a scale base 13 and a scale case 14,
The load cell 15 includes a strain generating portion 16 having a large rated load.
And a strain generating portion 17 having a small rated load. The load cell 15 is configured such that the lower end of one end on which the strain-generating portion 16 is formed is connected to the scale base 13 via a mounting base 18.
It is fixed to.

A small load transmission shaft 19 and a large load transmission shaft 20 are fixed to the upper surface of the load cell 15. The small load transmission shaft 19 is fixed to a load point 17a for the strain generating portion 17 located at the other end of the load cell 15, and extends upward. The large load transmission shaft 20 is fixed to a load point 16a for the strain generating portion 16 and extends upward.

At the upper end of the large load transmitting shaft 20, a substantially central portion of a large load tray receiving frame 21 is fixed. The small load transmission shaft 19 is provided with the large load pan support frame 21.
A small-load dish receiving frame 22 is fixed to the upper end of the large-load dish receiving frame 21 so as to extend through the through-hole 21a formed at the upper end thereof. It should be noted that the small load pan receiving frame 22 and the large load pan receiving frame 21
Are arranged in parallel and opposed to each other. A first magnet 23 as a magnetic force generator is fixed to the lower surface of the four corners of the small load pan receiving frame 22.

Above the weighing case 14, a weighing dish 24 on which a weighing object is placed is arranged. This weighing dish 24
A dish support shaft 25 extending downward is fixed to the lower surface of each of the four corners. These pan support shafts 25 are connected to the weighing case 1.
4 and further penetrates through holes 22 a formed at four corners of the small load pan receiving frame 22 and through holes 23 a formed at the center of the first magnet 23. A second magnet 26, which is an adsorbent, is fixed to the lower end side of the dish support shaft 25 that has penetrated the through holes 22a and 23a.
The magnet 26 can be attracted to and separated from the first magnet 23.

FIG. 3A shows a first magnet 23 and a second magnet 26.
FIG. 3B shows a state in which the first magnet 23 is attracted.
And the second magnet 26 are separated from each other. First
When the magnet 23 and the second magnet 26 are attracted, the weighing pan 24
And the small load pan receiving frame 22 are connected, and the weighing pan 24
The load of the weighing object placed thereon is applied to the strain generating unit 17 via the small load pan support frame 22 and the small load transmission shaft 19. When the first magnet 23 and the second magnet 26 are separated,
The lower end of the plate support shaft 25 abuts the four corners of the upper surface of the large load pan receiving frame 21 to connect the weighing pan 24 and the large load pan receiving frame 21, and the weighing object placed on the weighing pan 24. Is applied to the strain generating portion 16 via the large load dish receiving frame 21 and the large load transmission shaft 20.

When the load of the weighing object is applied to the strain generating section 16 for weighing, the distance between the first magnet 23 and the second magnet 26 is "L" (see FIG. 3B). The distance “L” and the magnetic force acting between the first and second magnets 23 and 26 are smaller than the value at which the load acting on the weighing dish 24 is separated by the first and second magnets 23 and 26. Sometimes, the first magnet 23 and the second magnet 26 in the separated state are set to be automatically attracted. Therefore, when the weighing object is removed from the weighing dish 24, the first magnet 23 and the second magnet 26 automatically return to the attracted state in FIG.

FIG. 4 is a block diagram showing a circuit structure of the load cell scale. A small load measuring unit 27 that generates an electric signal according to the amount of strain of the strain generating unit 17 having a small rated load, and a large load measuring unit 28 that generates an electric signal according to the amount of distortion of the strain generating unit 16 having a large rated load. Are connected to the amplifier 30 via the changeover switch 29. The amplifier 30 is connected to the CPU 32 via the A / D converter 31. The changeover switch 29 is directly connected to the CPU 32. Further, a display 33 and a keyboard 34 are connected to the CPU 32 via a control circuit (not shown).

In such a configuration, FIGS. 1 and 3
(A) shows a case where the load of the weighing object placed on the weighing pan 24 is equal to or less than a predetermined value. In this case, the first
The magnet 23 and the second magnet 26 are attracted, and the weighing dish 24 and the small load dish receiving frame 22 are connected. For this reason, the load of the weighing object is applied to the strain generating section 17 via the small load dish receiving frame 22 and the small load transmission shaft 19, and the strain is generated in the strain generating section 17. Then, an electric signal corresponding to the amount of distortion is generated from the small load weighing unit 27, the electric signal is amplified by the amplifier 30, then converted into a digital signal by the A / D converter 31 and input to the CPU 32. The CPU 32 performs processing based on the weighing data converted into the digital signal by the A / D converter 31 and the unit price data input from the keyboard 34, and the display unit 33 displays the unit price, weight value, price, and the like. You.

Next, FIG. 3B shows a case where the load of the weighing object placed on the weighing pan 24 is equal to or more than a predetermined value. In this case, since the load of the weighing object exceeds the attraction force between the first magnet 23 and the second magnet 26, the first magnet 23
And the second magnet 26 are separated from each other, and the weighing dish 24 and the large load dish receiving frame 21 are connected by the lower end of the dish support shaft 25 contacting the four corners of the upper surface of the large load dish receiving frame 21. . For this reason, the load of the weighing object is applied to the strain generating portion 1 via the large load pan receiving frame 21 and the large load transmission shaft 20.
6, and strain is generated in the strain generating section 16. Then, an electric signal corresponding to the amount of distortion is generated from the heavy load measuring section 28, and after the electric signal is amplified by the amplifier 30, the A / D
The digital signal is converted by the converter 31 and input to the CPU 32. The CPU 32 performs processing based on the weighing data converted into the digital signal by the A / D converter 31 and the unit price data input from the keyboard 34, and the like.
3 displays a unit price, a weight value, a price, and the like.

Here, in the load cell balance of the present embodiment, when the load of the weighing object is equal to or less than the predetermined value, the weighing is performed by applying a load to the strain generating portion 17 having a small rated load. If the value is equal to or more than a predetermined value, the strain generating portion 1 having a large rated load
Since the measurement is performed by applying a load to 6, a highly accurate measurement can be performed in a wide range from a small load to a large load.

In addition, the switching between the measurement performed by applying a load to the strain generating portion 17 having a small rated load and the measurement performed by applying a load to the strain generating portion 16 having a large rated load is performed by the first magnet 23.
And the second magnet 26 are attracted and separated. For this reason, even if vibrations or the like are transmitted from the outside to the load cell scale at the time of weighing, weighing performed by applying a load to the strain generating section 17 and the strain generating section 1 are performed.
Switching to weighing performed by applying a load to 6 does not occur repeatedly, and stable weighing can be performed.

Next, after weighing a weighing object having a load equal to or greater than a predetermined value, the weighing object is removed from the weighing pan 24, and the first magnet 23 and the second magnet 26 in the separated state are automatically set. And returns to the state shown in FIGS. 1 and 3 (a). Therefore, it is not necessary to perform an operation of returning the separated first magnet 23 and second magnet 26 to the attracted state after weighing the weighed object having a load equal to or more than the predetermined value. Is improved.

Next, a load cell scale according to a second embodiment of the present invention will be described with reference to FIGS. 1 to 5 are denoted by the same reference numerals. This load cell balance has a load cell 15 in which a strain generating portion 16 having a large rated load and a strain generating portion 17 having a small rated load are formed.
To the scale base 13.

A small load transmission shaft 19 and a large load transmission shaft 20 are fixed to the upper surface of the load cell 15. At the upper end of the large load transmission shaft 20, a large load pan support frame 3
5 is fixed. The small load transmission shaft 19 passes through a through hole 35a formed in the large load pan receiving frame 35 and a through hole 36a formed in a pan support plate 36 fixed integrally with the weighing pan 24 and moves upward. One end of the small load pan receiving frame 37 is fixed to the upper end thereof. It should be noted that the small load pan receiving frame 37 and the pan support plate 36
And the large load pan receiving frame 35 are arranged to face each other in parallel. The four corners of the plate support plate 36 and the four corners of the weighing plate 24 are fixed by a plate support shaft 38, and these plate support shafts 38 pass through the weighing case 14.

A first magnet 39, which is a magnetic force generator, is fixed to the lower surface of the other end of the small load dish receiving frame 37, and a second magnet, which is an adsorbent, is provided at the center of the upper surface of the small load dish receiving frame 37. The magnet 40 is fixed, and the second magnet 40 can be attracted to and separated from the first magnet 39.

A convex stopper 41 is fixed to the lower surface of the four corners of the plate support plate 36. A concave stopper 42 is formed on the upper surface of the four corners of the large load pan receiving frame 35.

FIG. 6 shows a state where the first magnet 39 and the second magnet 40 are attracted, and FIG. 7 shows a state where the first magnet 39 and the second magnet 4 are attracted.
0 indicates a state separated. When the first magnet 39 and the second magnet 40 are attracted, the weighing dish 24 and the dish support plate 3
6 and the small load pan receiving frame 37 are connected, and the weighing pan 2
The load of the weighing object placed on the 4 is applied to the strain generating unit 17 via the small load dish receiving frame 37 and the small load transmission shaft 19. When the first magnet 39 and the second magnet 40 are separated, the stoppers 41 and 42 are engaged, and the weighing dish 24, the dish support plate 36, and the large load dish receiving frame 35 are connected. The load of the placed weighing object is applied to the strain generating section 16 via the large load pan receiving frame 35 and the large load transmission shaft 20.

Next, when the load of the measurement object is applied to the strain generating section 16 to perform the measurement, the first magnet 39 and the second magnet 40
Is "L" (see FIG. 7). And
When the distance “L” and the magnetic force of the first and second magnets 39 and 40 become equal to or less than the predetermined value, the first magnet 39 and the second magnet 40 are separated from each other. Is set to be automatically absorbed.

In such a configuration, FIG. 6 shows a case where the load of the weighing object placed on the weighing pan 24 is equal to or less than a predetermined value. In this case, the first magnet 39 and the second magnet 40 are attracted, and the weighing dish 24, the dish support plate 36, and the small load dish receiving frame 37 are connected. For this reason, the load of the weighing object is applied to the strain generating section 17 via the small load dish receiving frame 37 and the small load transmission shaft 19, and the strain generating section 17
Can be measured in accordance with the amount of distortion.

Next, FIG. 7 shows a case where the load of the weighing object placed on the weighing pan 24 is equal to or more than a predetermined value.
In this case, since the load of the weighing object exceeds the attraction force between the first magnet 39 and the second magnet 40, the first magnet 39 and the second magnet
The magnet 40 is separated, the weighing pan 24 and the pan support plate 36 move downward, and the stopper 41 engages with the stopper 42, so that the weighing pan 24, the pan support plate 36, and the large load pan receiving frame 35 are connected. Be linked. For this reason, the load of the weighing object is applied to the strain generating portion 16 via the large load dish receiving frame 35 and the large load transmission shaft 20, and the weighing according to the strain amount of the strain generating portion 16 can be performed.

Here, in the load cell scale of the present embodiment, when the load of the weighing object is equal to or less than the predetermined value, the weighing object is weighed by applying a load to the strain generating portion 17 having a small rated load. If the value is equal to or more than a predetermined value, the strain generating portion 1 having a large rated load
Since the measurement is performed by applying a load to 6, a highly accurate measurement can be performed in a wide range from a small load to a large load.

Further, the switching between the measurement performed by applying a load to the strain generating portion 17 having a small rated load and the measurement performed by applying a load to the strain generating portion 16 having a large rated load is performed by the first magnet 39.
And the second magnet 40. For this reason, even if vibrations or the like are transmitted from the outside to the load cell scale at the time of weighing, weighing performed by applying a load to the strain generating section 17 and the strain generating section 1 are performed.
Switching to weighing performed by applying a load to 6 does not occur repeatedly, and stable weighing can be performed.

Further, since there is one first magnet 39 and one second magnet 40, the first magnet 39 and the second magnet 40
Adsorption and separation of the strain are smoothly performed, and the switching between the measurement applied to the strain generating section 16 and the measurement applied to the strain generating section 17 can be accurately switched.

Next, after weighing an object having a load equal to or greater than a predetermined value, the object is lowered from the top of the weighing pan 24, and the first magnet 39 and the second magnet 40 in the separated state are automatically set. And returns to the state shown in FIG. Therefore, it is not necessary to perform an operation of returning the separated first magnet 39 and second magnet 40 to the attracted state after weighing the weighed object having the load equal to or more than the predetermined value. Is improved.

In the first and second embodiments described above, one load cell 15 is provided with two strain generating portions 16,
17 has been described as an example, but has two load cells, and one load cell has one strain-flexing portion 16.
May be formed, and the other strain generating portion 17 may be formed on the other load cell.

The magnets 23 and 39 are used as magnetic force generators.
An electromagnet may be used in place of the magnet, and a magnetic body such as iron may be used in place of the magnets 26 and 40 as the adsorbent.

[0042]

According to the load cell balance of the present invention, the load is applied to the strain generating portion having a small rated load to perform the measurement, and the load is applied to the strain generating portion having the large rated load to perform the measurement. Is switched by adsorption and separation between the magnetic force generator and the adsorbent. Therefore, even if vibration is transmitted from the outside to the load cell scale at the time of weighing, a load is applied to the strain-generating part with a small rated load. Switching between the weighing performed and the weighing performed by applying a load to the strain generating portion having a large rated load can be prevented from repeatedly occurring, and the weighing of the load near the switching can be performed stably. .

According to the load cell balance of the second aspect of the present invention, when the load acting on the weighing pan becomes a predetermined value or less, the magnetic force generator and the adsorbent in the separated state automatically return to the adsorbed state. In addition, it is not necessary to perform an operation of returning the separated magnetic force generator and the adsorbent to the adsorbed state, and the handleability of the load cell balance can be improved.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional front view showing a load cell scale according to a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional front view showing a part thereof in an enlarged manner.

FIG. 3A is a front view showing a state where a first magnet and a second magnet are attracted, and FIG. 3B is a front view showing a state where the first magnet and the second magnet are separated.

FIG. 4 is a block diagram showing a circuit structure of the load cell scale.

FIG. 5 is a graph showing output characteristics from a small load measuring section and a large load measuring section.

FIG. 6 is a longitudinal sectional front view showing a state where a first magnet and a second magnet are attracted to each other in a load cell balance according to a second embodiment of the present invention.

FIG. 7 is a longitudinal sectional front view showing a state where a first magnet and a second magnet are separated.

FIG. 8 is a graph showing an allowable error range of the load cell scale.

FIG. 9 is a vertical sectional front view showing a conventional load cell scale.

[Explanation of symbols]

 15 Load cell 16, 17 Strain-flexing part 16a, 17a Load point 19 Small load transmission shaft 20 Large load transmission shaft 21, 35 Large load pan receiving frame 22, 37 Small load pan receiving frame 23, 39 Magnetic force generator 24 Weighing pan 26, 40 adsorbent

Claims (2)

[Claims] 1. A load cell having a plurality of strain generating portions having different rated loads, a small load transmission shaft fixed at a load point for the strain generating portion having a small rated load, and the strain generating portion having a large rated load. A large load transmitting shaft fixed at a load point with respect to a small load transmitting shaft, a small load pan receiving frame fixed above the small load transmitting shaft, a large load pan receiving frame fixed above the large load transmitting shaft, and weighing. A weighing dish on which an object is placed, a magnetic force generator fixed to the small load pan receiving frame or the weighing pan, and a magnetic force generator fixed to the weighing pan or small load receiving frame and coming into contact with and separating from the magnetic force generating body When the load on the weighing object placed on the weighing pan is equal to or less than a predetermined value, the magnetic force generator and the adsorbent are attracted and the weighing pan and the small Connected to the load pan support frame The load of the weighing object is applied to the strain generating portion having a small rated load via the small load pan receiving frame and the small load transmitting shaft, and the load of the weighing object placed on the weighing pan is predetermined. When the value is equal to or greater than the value, the magnetic force generator and the adsorbent are separated from each other, the weighing pan and the large load pan receiving frame are connected, and the load of the weighing object is increased by the large load pan receiving frame and the large load transmission shaft. A load cell scale having a large rated load applied thereto through 2. The load between the magnetic force generator and the adsorbent in the separated state and the magnetic force acting between the magnetic force generator and the adsorbent are reduced to a predetermined value or less. 2. The load cell scale according to claim 1, wherein the magnetic force generator and the adsorber in a separated state are set so as to be automatically attracted.