JPS6196421A - Beam body of load cell balance - Google Patents

Abstract

PURPOSE:To improve a creep characteristic without changing a strain gauge by setting up the thickness of arm parts between thin deformed parts to a specific length in a beam body formation four thin deformed parts connected by the arm parts. CONSTITUTION:Two holes connected to each other are penetrated into the beam body 1 formed like a rectangular parallelepiped and four thin deformed parts 3 formed by the holes 2 are connected by the arm parts 4. The thickness of the arm parts 4 positioned between the thin deformed parts 3 is set up to a specific thickness, t=1.13mm e.g., so that flat status of which creeping characteristic is almost zero is formed. Consequently, the creeping characteristic can be improved by the beam body itself without changing the strain gauges.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a beam body of a load cell scale.

Conventional technology In general, in load cell scales, strain gauges are attached to the outer surfaces of four thin deformed parts formed in a beam body, and when the load of the object to be weighed is applied to the beam body. nosu 1
-The weight of the object to be measured is detected by changes in the electrical resistance of the range gauge.

Conventionally, the creep characteristics (permanent deformation of the material that occurs over time) are determined at the time the strain gauge is attached to the beam body. Therefore, in order to improve the creep characteristics, we repeatedly create strain gauges with good creep characteristics, attach them to the beam body, and perform evaluations.

Problems to be Solved by the Invention In the conventional method described above, it is difficult to always expect completely satisfactory characteristics, and there are limits. or.

Even if the creep properties are satisfied, the problem arises that other properties deteriorate due to changes in the strain gauge.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to obtain a beam body for a load cell weighing machine whose creep characteristics can be improved without changing the strain gauge.

Means for Solving the Problems In order to solve the problems mentioned above, the present invention discovered that the thickness t of the arm portion 4 between the thin deformed portions 3 in the beam body l affects the creep characteristics.

This thickness t is set to a specific thickness tl so that the creep property is in a flat state with almost zero.

Example An embodiment of the present invention will be described based on the drawings.

First, there is provided a beam body 1 formed into a rectangular parallelepiped made of high-strength aluminum that is easy to machine. Two holes 2 are formed through the beam body 1 in a continuous manner, and four thin-walled deformed parts 3 formed by these holes 2 form arms projecting in a chevron shape. They are connected by section 4. Then, a strain gauge 5 is attached to the outer surface of each of the thin-walled deformable parts 3. In addition, in the figure, the left side of the beam body 1 is a fixed part, and the right side is a load receiving part.

Therefore, in this embodiment, it has been found that when the thickness of the tool 11 portion 4 located between the thin deformed portions 3 is t, this thickness t influences the creep characteristics. here,
The length, width, and height of the entire beam body l are appropriately selected depending on the space of the scale to be installed.

First, as shown in FIGS. 2(a) to 2(c), beam bodies (2) are prepared in which the arm portions 4 have different thicknesses t1, t1, t3 (tx > tz) t3). In this case, in order to produce the same load cell output no matter which beam body l is present, when the thickness of the thin deformed portion 3 is W, the second
In figures (,) to (c), Wl, W2, 'JJ
3 is 'JJ t (W 2 (W 3). For example, in the case of FIG. 2(a), this is t+)tz, and the second
This is because Wl<W2 must be satisfied in order to produce the same output as shown in FIG. 2(b). Figures 3(a) to 3(a) show the creep characteristics of these three types of beam bodies 1.
(c). According to the results of this creep characteristic, the second
As shown in FIG. 3(b) and FIG. 3(b), it can be seen that the creep characteristics are improved to a flat state of almost zero by a certain thickness tl. It can also be seen that the creep characteristics are not improved even if the thickness is thinner (thickness t3) or thicker (tl) than this thickness tl, and that the creep characteristics are reversed depending on the size.

The beam body 1 according to this embodiment is shown in FIG. 1, and the thickness t of the arm portion 4 is set to a specific thickness tl. FIG. 4 shows an example of a concrete example in which the creep characteristic C becomes zero when, for example, tzt2 is set to 1.13 mm.

What must be noted here is that even if the thickness t is slightly more or less than this thickness of 1.13m, it is ±3X10-"
However, the creep characteristics only deteriorate to a very small extent, such as %.

Precisely because it is a scale, even a slight deterioration of the leap characteristic becomes a problem. Note that in the curve shown in FIG. 4, the thickness is t and the creep characteristic is C.

It is shown by the formula:

Effects of the Invention In the present invention, as described above, the thickness of the arm portion is set to a specific thickness so that the creep property is in a flat state with almost zero, so the creep property can be improved by the beam body itself. This eliminates the need to prepare a strain gauge with good creep characteristics, attach it to the beam body, and repeatedly evaluate the creep characteristics.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention; FIG. 1 is a side view, FIGS. 2(a) to (c) are side views showing samples with different thicknesses t, and FIGS. 3(a) to 3(c) are side views showing samples with different thicknesses t. (c) is shown in Figure 2 (,) to (e
), and FIG. 4 is a creep characteristic diagram showing a concrete example of actual measurements. 1... Beam body, 2... Hole, 3... Thin deformed part,
4...Arm body, 5...S1-range gauge, t...
Thickness Applicant: Tokyo Electric Co., Ltd., 5. Good idea V Neit? Author: % formula % 1, Indication of the case Patent application No. 59-217579 2, Name of the invention Beam body of load cell scale 4, Agent 107 Address: 5-9-15 Minami-Aoyama, Minato-ku, Tokyo Showa 60 years 1
Month 29th (Shipping field 6, drawing subject to correction 7, correction content t...Month 2nd)

Claims (1)

[Claims] A beam body is provided in which four thin-walled deformed parts are formed through two holes in a rectangular parallelepiped-shaped metal material and connected by an arm part, and a strain gauge is placed on the thin-walled deformed parts of this beam body. The weight of the object to be weighed is detected by the change in electrical resistance of the strain gauge when the load of the object to be measured is applied to the beam body, and the creep characteristic is almost zero. A beam body of a load cell weighing device, characterized in that the thickness of the arm portion between the thin-walled deformed portions is set so as to be in a flat state.