JPS6085334A - Load-cell type load meter - Google Patents

Abstract

PURPOSE:To enhance efficiency in adjustment of unbalanced load indication, by forming a load receiving body, whose four corners of rectangular hollow part provided at the central part are cut out in a concave shape, and attaching detecting elements in correspondence with concave cut parts. CONSTITUTION:A load receiving body 2 has a specified thickness and a rectangular shape. A rectangular hollow part 3 is formed at the central part. Arc shaped concave surfaces 5 are cut out at both side parts of its lower surface 4. Four detecting elements 7 of strain gages, which are finished highly accurately and have a specified thickness, are attached in correspondence with the concave surfaces 5. They are electrically connected in a bridge circuit formation, and the electric signals are added and outputted. One side surface 8 of the load receiving body 2 is fixed to a base plate 9. A measuring pan 12 is fixed to another side surface 8 through a pan attaching member 11, and a load-cell type load meter 1 is constituted. Thus, the weight indication of the detecting elements 7 with respect to the unbalanced load corresponding to the measurement can be adjusted positively and efficiently.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a load cell type load cell that detects weight by changes in the electrical characteristics of a detection element such as a resistance wire strain element or a crystal oscillator attached to a load receiver.
This invention relates to a load cell type load cell that adjusts the weight display due to the uneven load acting on the weighing pan.

Conventionally, a detection element such as a strain gauge is attached to a load receiver made of an elastic body, one end of the load receiver is supported by a support member, and a weighing pan is attached to the movable end of the load receiver. When the object to be weighed is placed on this weighing pan, the above-mentioned detection element is distorted in response to the distortion of the load receiver, so by detecting the change in electrical characteristics due to this distortion and converting it into weight, it is possible to measure the object to be weighed. A load cell type load cell that measures the weight of objects has been put into practical use, and this type of load cell has a relatively simple configuration and high accuracy.
Since it outputs an air signal, it has the advantage that it can be used as is in electrical digital display scales, etc. In addition, as mentioned above, the distortion of the detection element is output as an @air signal, so if multiple detection elements are used, the output of the electrical signal will also be large, so recently multiple detection elements have been installed at different locations on the load receiver. Those with a detection element attached are often used.

In addition, in the case of a load cell, the object to be weighed is not always placed in the center of the weighing pan, but sometimes the object to be weighed is placed in a corner of the weighing pan. Even in the case of such an uneven load, it is necessary to be able to accurately measure the weight.

However, in the case of a load cell type load cell, the processing accuracy of the load receiver made of an elastic body, the material and processing accuracy of the multiple detection elements, the attachment position and attachment condition of each detection element, the thickness and properties of the adhesive, etc. Various conditions greatly affect measurement accuracy, and ideally, it is desirable that all of the above conditions meet the manufacturing requirements at the time of manufacturing, but it is not possible to manufacture from the beginning with all of these conditions fully satisfied. Have difficulty. If even some of the above conditions are off, the stress acting on each detection element will be unbalanced, so the weight display may be off, especially for loads that are biased toward each corner of the weighing pan. occurs, making it difficult to accurately measure ftt. For this reason, in the above case, it is necessary to make adjustments so that the weight display for each unbalanced load matches, but no load cell type load cell has been found that can effectively perform the above adjustment.

This invention was made to improve the above situation.
The purpose of this is to provide a load cell type load indicator 1'f that can reliably and efficiently adjust the weight display for unbalanced loads.
: What we are trying to provide.

The present invention will be explained below with reference to embodiments shown in the drawings. This will be explained one by one using a beam cell type load cell as shown in the figure. The load receiver 2 of the load cell 1 is formed into a rectangular shape with a predetermined thickness as shown in FIG. Both sides of the upper and lower surfaces 4 are cut into arcuate concave surfaces 5, and detection elements 7 made of strain gauges are affixed at 40 locations on the upper and lower surfaces 6 of the load fi receiver 2 corresponding to the concave surfaces 5, Further, the thickness of the adhesive portion of the detection element 7 (the distance between the upper and lower surfaces 6 and the arcuate concave surface 5) is finished to a predetermined dimension with high precision. Further, the four detection elements 7 are electrically connected in a bridge circuit format, so that electrical signals from the four detection elements 7 are summed and output. The distance between both side surfaces 8 of the load receiver 2 is finished to a predetermined dimension, one side surface 8 is fixed and supported by the vertical part of an L-shaped support member 10 fixed on the substrate 9, and the load receiver 2 is Side surface 8 on the movable end side of body 2
The lower part of the catch mounting member 11 is fixed to the
The center part of the lower surface of the flat weighing plate 12 is fixed to the upper part of the weighing plate 12.

When the object to be weighed is placed on the weighing pan 12, the weight of the object acts on the movable end side of the load receiver 2.
The four places where the detection element 7 is attached are distorted due to stress (tensile stress acts on the upper rear and lower front and rear parts, and compressive stress acts on the upper front and lower rear parts). So,
The four detection elements 7 attached to this part are also distorted, and output electrical signals corresponding to the amount of distortion.
Since the four detection elements 7 are connected in a bridge circuit format, the electrical signals from the four detection elements 7 are summed, enlarged and output, and the output amount of this electrical signal is converted into weight and displayed. By doing so, the weight of the object to be weighed is measured.

Next, the gist of the invention will be explained. In other words, if the weight display for an unbalanced load deviates because the processing dimensions and materials of the load receiver 2, the detection element 7, the material, or the attachment position of the detection element 7 do not match the ideal conditions during manufacturing, the accuracy may vary. Since accurate measurements cannot be made, it is necessary to make adjustments, but we will explain how to do this step by step. First, a load is sequentially applied to each of the corners A, B, O, and D, which are the off-centered parts of the weighing pan 120. Detect the unbalanced load display value at section D. In addition, when the weight of the accurate load M (for example, 10100O) is displayed, it is set as 10, and when the weight displayed is small, it is set as -, for example, A.

If each part of B and O is 1g more than LOOOg+
The weight is displayed as 1 g = l OOl g, so
If +1 is displayed, and only the D portion is less than Ig, 1000g-1g=100O will be displayed, resulting in -1 display. This is because the amount of distortion in the portion A of the load receiver 2 corresponding to the portion D, which was displayed as -1, was smaller than that in other portions.

Therefore, if you increase the amount of strain in part A by scraping off part A of the load receiver 2, the weight display in part D will increase and change from - to 10, and in this way, the unbalanced load will be displayed. Each person by scraping off a predetermined part of the load receptor 2 corresponding to the value.

Adjust the displayed values of B, O, and D until they match. and 1
If the displayed values of each part of A, E, O, and D match, it means that the overall balance has been achieved, so if you adjust the weight conversion circuit according to the matched displayed values, measurement errors due to unbalanced loads will occur. , so accurate measurements can be made.

Note that the adjustment method is not limited to the above embodiments, for example, A
If the two locations B and B are displayed as one, the corresponding portions of the load receiver 20 may be scraped off, and the unbalanced load display values at each corner may be adjusted to match. , it goes without saying that the position of each corner to be detected can also be selected as appropriate.

As described in detail above, this invention is formed into a rectangular shape with a predetermined thickness, a rectangular hollow part is provided in the center part to form a parallelogram, and horizontal beam parts above and below the parallelogram. A load receptor P is formed by cutting the vicinity of both sides of the load receptor P into a concave shape, and a detection element is attached to a position corresponding to the concave cut portion of the load receptor to form a load cell having one load receptor. One end of the one load receptor is supported by a support member, and a weighing pan is attached to the movable end of the load receptor to form a load cell. After assembly, each corner of the weighing pan is Detect the unbalanced load display value at each corner by applying a load to the part, and cut a predetermined part of the load receiver in accordance with the unbalanced load display value so that the unbalanced load I chopsticks at each corner match. It is characterized by the fact that it was taken. Therefore, the load receiver used in the load cell of the present invention has a predetermined portion cut off in accordance with the unbalanced load display value at each corner of the weighing pan.
.

Accurate measurement is possible even when a load is applied to the corner of the weighing pan.

In addition, adjustment can be made by simply scraping off a portion of the load receiver in accordance with the displayed value of the unbalanced load at each corner of the weighing pan, making it possible to adjust the unbalanced load very reliably and efficiently. It has excellent effects such as being able to easily and inexpensively manufacture a load cell.

[Brief explanation of drawings]

Fig. 1 is a perspective view of a cell type load cell for explaining an embodiment of the present invention, Fig. 2 is a side view of the same load cell, and Fig. 3 is a perspective view of a load receiver of the same load cell. 01...Load cell type load meter, 2...Load receiver 17...Detection element, 9.
... Substrate, 10... Supporting member, 11... Capturing and mounting member, 12... Weighing pan, A, T3. O, D...each corner of the weighing pan, A...the portion of the load receiver to be scraped off. Figure 2 1 Figure 3

Claims (1)

[Claims] A plurality of detection elements are attached to a load receiver, one end of the load receiver is supported by a support member, a weighing pan is attached to the movable end of the load receiver, and an object to be weighed is attached to the weighing plate. The load cell type load cell detects the weight of the object to be weighed by converting changes in the electrical characteristics of each of the detection elements described above into weight when a weight is placed on the object. A rectangular hollow part is provided in the section to form a parallelogram, and the vicinity of both sides of the upper and lower horizontal beam parts of the parallelogram are cut into concave shapes to form one load receiver. A load cell having one load receptor is formed by pasting a detection element at a position corresponding to the concave cut portion of the body, and the above-mentioned 1.
One end of each load receptor is supported by a support member, and several weighing pans are placed at the movable end of the load receptor to form a load cell. After assembly, a load is applied to each corner of the weighing pan. Detect the unbalanced load display value at each corner by applying Features: Load cell type load cell.