JP2021081291A - Load cell four-corner adjustment method and load cell manufacturing method using said method - Google Patents

Abstract

To provide a load cell four-corner adjustment method with which it is possible to facilitate the four-corner adjustment of a load cell equipped with two Roberval mechanisms.SOLUTION: Provided is a four-corner adjustment method for a load cell equipped with: first and second Roberval mechanism parts 2, 3, each including a fixed part 11 and a movable part 12 and a pair of beam parts 13, 14 for connecting the fixed part 11 and the movable part 12 and having a plurality of strain-causing parts D1-D4 formed therein, and arranged in parallel in a row in the horizontal direction; a first connection part 4 for connecting the fixed parts 11 to each other; a second connection part 5 for connecting the movable parts 12 to each other; and a plurality of strain gauges G pasted to the outside surface of the plurality of strain-causing parts D1-D4. The four-corner adjustment is carried out by shaving the inside surfaces of strain-causing parts D1-D4 of the first Roberval mechanism part 2 from the opposite side facing the second Roberval mechanism part 3, and/or by shaving the inside surfaces of strain-causing parts D1-D4 of the second Roberval mechanism part 3 from the opposite side facing the first Roberval mechanism part 2.SELECTED DRAWING: Figure 1

Description

The present invention relates to a method for adjusting the four corners of a load cell and a method for manufacturing a load cell using the method.

Generally, a load receiving member such as a saucer for holding an object to be measured is attached to the load cell, and an output signal from the load cell when the object to be measured is held at a corner of the load receiving member and an unbalanced load is applied. However, the four corners are adjusted so that the output signal is the same as when the object to be weighed is held in the central portion of the load receiving member.

Patent Document 1 describes a method for adjusting four corners of a double beam type load cell by scraping at least one of the cut portions on the arc concave surface of the load receiver to which the strain gauge is attached. However, this method is based on the craftsman's experience and intuition for a general double-beam type load cell equipped with one reverbal mechanism. Even if the same double beam type load cell has a special shape provided with two reverbal mechanism parts, a simple four-corner adjustment method suitable for the load cell is required.

Japanese Unexamined Patent Publication No. 60-85334

An object of the present invention is to provide a load cell four-corner adjustment method capable of easily performing four-corner adjustment of a load cell provided with two reverbal mechanism portions, and a load cell manufacturing method using the method.

In order to achieve the above object, the method for adjusting the four corners of the load cell according to an embodiment of the present invention has a fixed portion and a movable portion arranged at a distance in the first horizontal direction and a movable part at a distance in the vertical direction, respectively. It has a pair of beam portions which are arranged in parallel and are connected to the fixed portion and the movable portion to form a plurality of strain-causing portions, and in a second horizontal direction perpendicular to the first horizontal direction. A first connecting portion that connects the first and second reverbal mechanism portions arranged side by side in parallel, the fixing portion of the first reverbal mechanism portion, and the fixing portion of the second reverbal mechanism portion. A second connecting portion that connects the movable portion of the first reverbal mechanism portion and the movable portion of the second reverbal mechanism portion, and a plurality of affixed to the outer surfaces of the plurality of strain generating portions. The strain gauges of the first and second reverbal mechanisms are provided, and the strain-causing portions of the first and second reverbal mechanism portions are provided in the pair of beam portions, in a portion closer to the fixed portion and a portion closer to the movable portion. It is a method of adjusting the four corners of the formed load cell, in which the inner surface of the strain generating portion of the first reverbal mechanism portion is scraped from the side opposite to the side facing the second reverbal mechanism portion, and / Alternatively, the four corners are adjusted by scraping the inner surface of the strain-causing portion of the second reverbal mechanism from the side opposite to the side facing the first reverbal mechanism, and the first reverbal mechanism is adjusted. The four corners are not adjusted by scraping the inner surface of the strain-causing portion from the side facing the second reverbal mechanism portion, and the inner surface of the strain-causing portion of the second reverbal mechanism portion is the first. The four corners are not adjusted by scraping from the side facing the load cell mechanism of 1.

Further, as a method for manufacturing a load cell according to a certain aspect of the present invention, the above-mentioned method for adjusting the four corners of a load cell is used.

According to the present invention, since only the portion close to the outside of the inner surface of the strain-causing portion is scraped to perform the four-corner adjustment, the four-corner adjustment can be easily performed.

The present invention provides a load cell four-corner adjustment method capable of easily performing four-corner adjustment of a load cell having the configuration described above and having two reverbal mechanism portions, and a load cell manufacturing method using the method. It has the effect of being able to do it.

FIG. 1 is a perspective view showing an example of a load cell for adjusting four corners in the present embodiment. FIG. 2A is a plan view of the load cell shown in FIG. 1, and FIGS. 2B, 2C, and 2D are side views of the load cell viewed from different directions. FIG. 3 is a perspective view for explaining a method of adjusting the four corners of the load cell of the present embodiment.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In the following, the same or corresponding elements will be designated by the same reference numerals throughout the drawings, and duplicate description thereof will be omitted. Further, the present invention is not limited to the following embodiments.

(Embodiment)
FIG. 1 is a perspective view showing an example of a load cell for adjusting four corners in the present embodiment. FIG. 2A is a plan view (viewed from above) of the load cell shown in FIG. 1, and FIG. 2B is a side view of the load cell viewed from the direction of arrow b in FIG. 2A. 2 (C) is a side view of the load cell viewed from the direction of arrow c in FIG. 2 (A), and FIG. 2 (D) is a view of the load cell from the direction of arrow d in FIG. 2 (A). It is an enlarged view of the side view. Note that, in FIG. 2D, only the first reverbal mechanism portion 2 and the portion in the vicinity thereof are shown, and the stopper member 6 and the like are not shown.

The load cell 1 for adjusting the four corners in the present embodiment is a first and second connecting portion 4 that connects the first and second reverbal mechanism portions 2 and 3 and the first and second reverbal mechanism portions 2 and 3. , 5, a stopper member 6, and a plurality of strain gauges G and the like are provided.

The first and second reverbal mechanism portions 2 and 3 have the same configuration and are provided in parallel with each other separated in the horizontal direction.

Each of the reverbal mechanism portions 2 and 3 is an upper beam portion that connects a columnar fixing portion 11 that is supported and fixed, a columnar movable portion 12 to which a load is applied, and an upper portion of the fixing portion 11 and an upper portion of the movable portion 12. It has a lower beam portion 14 that connects the lower portion of the fixed portion 11 and the lower portion of the movable portion 12. The upper beam portion 13 and the lower beam portion 14 are arranged in parallel with a distance in the vertical direction, and a plurality of strain generating portions D1 to D4 composed of thin-walled portions are formed at two locations symmetrical in the vertical direction. ing. Here, in the upper beam portion 13 and the lower beam portion 14, the strain generating portions D1 and D3 are formed in the portion closer to the fixed portion 11, and the strain generating portions D2 and D4 are formed in the portion closer to the movable portion 12. A strain gauge G for load detection is attached to the outer surfaces of the strain generating portions D1 to D4 (the upper surfaces of the strain generating portions D1 and D2 and the lower surfaces of the strain generating portions D3 and D4).

The first connecting portion 4 connects the fixing portions 11 and 11 of the first and second reverbal mechanism portions 2 and 3, and the second connecting portion 5 connects the first and second reverbal mechanism portions 2 and 2. The movable parts 12, 12 of No. 3 are connected to each other. Each of the fixing portions 11 and 11 is provided with a fixing hole 21 for fixing the load cell 1. Further, the second connecting portion 5 is provided with a hole 22 for attaching a load receiving member such as a saucer or a hopper for holding the object to be measured. When the object to be measured is held by the load receiving member, a load is applied to the second connecting portion 5 and the movable portions 12 and 12 connected to the second connecting portion 5.

In each of the above-mentioned reverbal mechanism portions 2 and 3, the fixed portion 11 and the movable portion 12 are arranged at a distance in the first horizontal direction, and the first reverbal mechanism portion 2 and the second reverbal mechanism portion 3 are arranged. Are arranged in parallel with each other in the second horizontal direction perpendicular to the first horizontal direction. The first connecting portion 4 and the second connecting portion 5 are formed so as to extend in the second horizontal direction, respectively, and are arranged side by side in the first horizontal direction and arranged in parallel. The first and second horizontal directions are indicated by arrows in FIG. 2 (A).

The stopper member 6 is a member for preventing damage to the load cell 1 due to overload. In order to attach the stopper member 6, a stepped hole 41 is provided in the central portion of the first connecting portion 4, and a through hole 51 is provided in the central portion of the second connecting portion 5. The tip portion of the stopper member 6 is inserted from the outside of the stepped hole 41 and further inserted into the through hole 51. At this time, the base end portion of the stopper member 6 is press-fitted into the stepped hole 41, so that the stopper member 6 is fixed to the stepped hole 41. The diameter of the tip portion of the stopper member 6 is configured to be smaller than the diameter of the through hole 51.

The manufacturing method of the load cell 1 will be briefly described. For example, a rectangular parallelepiped-shaped strain-causing body made of aluminum or the like is processed to form a portion other than the strain gauge G and the stopper member 6. The strain gauge G and the stopper member 6 are prepared separately. The stopper member 6 may be made of the same material as the strain-causing body, or may be made of a different material.

When processing the rectangular parallelepiped-shaped strain-causing body, for example, in a plan view, a region portion surrounded by the first and second reverberant mechanism portions 2 and 3 and the first and second connecting portions 4 and 5 is formed. The internal space Sp1 is formed by hollowing out. Next, in the forming portions of the first and second reverbal mechanism portions 2 and 3, the region portion surrounded by the fixed portion 11, the movable portion 12, the upper beam portion 13 and the lower beam portion 14 is hollowed out from the respective side surface directions. Space Sp2 is formed. At this time, the arcuate region corresponding to the strain generating portions D1 to D4 may be formed last.

Next, the stopper member 6 is attached, and the strain gauge G is attached to the upper surface Fa and the lower surface Fb of the first and second reverbal mechanism portions 2 and 3 corresponding to the strain generating portions D1 to D4 with an adhesive. Here, the eight strain gauges G attached are connected to a circuit type such as a Wheatstone bridge, and correspond to the strain generated in the strain generating portions D1 to D4 when a load is applied to the movable portion 12. The electric signal is output from the load cell 1. This output signal is a load signal according to the magnitude of the load, and this load signal is converted into a weight value.

After that, the four corners are adjusted. FIG. 3 is a perspective view for explaining a method of adjusting the four corners of the load cell 1. When adjusting the four corners, a weighing device incorporating the load cell 1 or a simulated device simulating the device is used, and a load cell or the like is inserted into two fixing holes 21 in a predetermined mounting portion of the load cell 1 in this device. 1 is fixed, and a load receiving member 101 such as a saucer (weighing dish) for holding an object to be measured is attached to the load cell 1. In the example of FIG. 3, by attaching the support member 102 that supports the load receiving member 101 to the hole 22 with a bolt or the like, the load receiving member 101 is attached substantially directly above the load cell 1, but the load cell is a load cell with the hopper as the load receiving member 101. 1 may be arranged side by side and attached to the hole 22 with a bolt or the like via the support member 102 to adjust the four corners.

In the four-corner adjustment, for example, similarly to a general load cell provided with one reverbal mechanism portion, a predetermined sample is sequentially placed on each of the four corner portions A to D of the load receiving member 101, and the load cell 1 at that time is placed. The inner surface of any of the strain generating portions is filed and adjusted so that the output signal of the above is equivalent to the output signal when the sample is placed on the central portion of the load receiving member 101.

When adjusting the four corners, the portion to be scraped with a file or the like is a portion N1 to a portion on the inner surface of each of the strain generating portions D1 to D4 of the first reverbal mechanism portion 2 facing the second reverbal mechanism portion 3. N4, portions S1 to S4 on the opposite side, and portions N1 to N4 on the inner surface of the strain generating portions D1 to D4 of the second reverbal mechanism portion 3 facing the first reverbal mechanism portion 2. And the parts S1 to S4 on the opposite side to this are considered, and there are more target parts than the load cell having one reverbal mechanism part. Since there are individual differences in the processing accuracy for the strain-causing body of the load cell for which the four corners are adjusted and the location where the strain gauge G is attached, it is preferable to select the locations to be individually ground.

However, the present inventors have repeated trial and error in consideration of work efficiency and load cell strength, and have made the above-mentioned portions N1 to N4 on the inner surface of the strain-causing portions D1 to D4 of the first reverbal mechanism portions 2 and 3. We have invented a four-corner adjustment method that is easy to work with and has a small amount of parts to be scraped, by not scraping and scraping and adjusting the parts S1 to S4 on the opposite side. That is, the inner surfaces of the strain generating portions D1 to D4 of the first reverbal mechanism portion 2 are scraped from the side opposite to the side facing the second reverbal mechanism portion 3, and / or the second reverbal mechanism portion. The four corners are adjusted by scraping the inner surfaces of the strain generating portions D1 to D4 of No. 3 from the side opposite to the side facing the first reverbal mechanism portion 2. Thereby, the four corners can be easily adjusted.

For example, when the output signal of the load cell 1 when the sample is placed on the corner A is smaller than the output signal when the sample is placed on the center of the load receiving member 101, the part to be scraped is , The portions N1 and N3 on the inner surface of the strain generating portions D1 and D3 of the first reverbal mechanism portion 2 and the portions S1 and S3 on the opposite side thereof are considered, but in the present embodiment, the portions N1 and N3 are At least one of the parts S1 and S3 close to the outside is scraped without making it a target to be scraped.

In the present embodiment, the strain gauges G are attached to both the upper surface Fa and the lower surface Fb of the first and second reverbal mechanism portions 2 and 3, but the first and second reverbal mechanism portions 2 are attached. , 3 may be configured such that the strain gauge G is attached only to one of the upper surface Fa and the lower surface Fb.

From the above description, many improvements and other embodiments of the present invention will be apparent to those skilled in the art. Therefore, the above description should be construed as an example only and is provided for the purpose of teaching those skilled in the art the best aspects of carrying out the present invention. The details of its structure and / or function can be substantially changed without departing from the spirit of the present invention.

The present invention is useful as a method for adjusting the four corners of a load cell having two reverbal mechanism parts so that the four corners of the load cell can be easily adjusted.

1 Load cell 2 First reverbal mechanism part 3 Second reverbal mechanism part 4 First connecting part 5 Second connecting part 11 Fixed part 12 Movable part 13 Upper beam part 14 Lower beam part D1 to D4 Strain gauge G gauge

Claims (2)

The fixed portion and the movable portion, which are arranged at a distance in the first horizontal direction, and the fixed portion and the movable portion, which are arranged in parallel at a distance in the vertical direction, are connected to each other, and a plurality of strain generating portions are formed. A first and second reverbal mechanism unit having a pair of formed beam units and arranged in parallel in a second horizontal direction perpendicular to the first horizontal direction.
A first connecting portion that connects the fixing portion of the first reverbal mechanism portion and the fixing portion of the second reverbal mechanism portion, and
A second connecting portion that connects the movable portion of the first reverbal mechanism portion and the movable portion of the second reverbal mechanism portion, and
A plurality of strain gauges attached to the outer surface of the plurality of strain generating portions, and a plurality of strain gauges.
With
Adjusting the four corners of the load cell in which the strain-causing portions of the first and second reverbal mechanism portions are formed in the portion closer to the fixed portion and the portion closer to the movable portion in each of the pair of beam portions. It ’s a method,
The inner surface of the strain-causing portion of the first reverbal mechanism is scraped from the side opposite to the side facing the second reverbal mechanism, and / or the strain of the second reverbal mechanism is formed. The four corners are adjusted by scraping the inner surface of the portion from the side opposite to the side facing the first reverbal mechanism portion.
The four corners are not adjusted by scraping the inner surface of the strain-causing portion of the first reverbal mechanism from the side facing the second reverbal mechanism, and the strain of the second reverbal mechanism is not adjusted. The four corners are not adjusted by scraping the inner surface of the portion from the side facing the first reverbal mechanism portion.
How to adjust the four corners of the load cell. A method for manufacturing a load cell using the method for adjusting the four corners of the load cell according to claim 1.

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