JPH11295014A - Strain gauge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a strain gage which can find out a strain gauge that nearly the same temperature coefficient of resistance when the resistance of the strain gauge varies depending upon impressed strain. SOLUTION: A strain gauge is constituted of a cut piece of a rolled metallic sheet the resistance value of which varies depending upon impressed strains. A strain detector is obtained by incorporating the strain gauge provided with an indicating section 5 which is provided on an insulating plate to which the main body 3 of the strain gauge cut off from the roller metallic sheet is stuck and indicates the cut-off position of the main body 3 from the metallic sheet adjacently to the main body 3 in a bridge circuit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a strain gage, and more particularly to a strain gage having excellent matching of temperature characteristics of strain gages to be combined.

[0002]

2. Description of the Related Art A strain gauge comprises a resistor element.
When a strain is applied to this, the resistance value changes in proportion to the amount of the strain. A measuring unit such as a measuring device or a pressure gauge is provided with a detecting unit including a strain gauge utilizing this property. The strain gauge adds a small amount of manganese and iron atoms to the nickel-copper alloy to minimize the change in resistance with temperature. Even if the variation of the resistance value due to the temperature change is minimized, the strain gauge will have its own unique temperature coefficient.

[0003]

Normally, when a detecting unit such as a measuring instrument is constituted by using a strain gauge, a bridge circuit is formed by randomly combining four or eight strain gauges to be manufactured. The circuit is a detection unit. In this bridge circuit, if the resistance temperature coefficients of the individual strain gauges are slightly different, the balance of the bridge will collapse due to temperature changes, and an apparent output due to temperature will be output. Must be provided with a temperature compensation circuit.

An object of the present invention is to solve the above-mentioned technical disadvantages of the prior art. It is an object of the present invention to provide a strain gauge having a resistance temperature coefficient which is substantially the same as that of a strain gage whose resistance value changes by applying strain. An object of the present invention is to provide a strain gauge that can accurately find a gauge.

[0005]

In order to achieve the object of the present invention as described above, according to the first aspect of the present invention, a metal whose resistance value changes by applying strain is cut out from a rolled metal rolled sheet. In the obtained strain gauge, on the insulating plate to which the main body of the strain gauge cut out from the rolled metal sheet is adhered, a display unit that displays the position where the main body of the strain gauge is cut out from the rolled metal sheet. A strain gauge provided adjacent to a main body of the strain gauge.

In the invention according to claim 2, in a strain gauge cut out from a rolled metal sheet obtained by rolling a metal whose resistance value changes by application of strain, a main body of the strain gauge cut out from the rolled metal sheet is attached. On the insulating plate, a display portion indicating a position where the main body of the strain gauge is cut out from the metal rolled sheet at least in an address in a row direction along a rolling direction of the metal rolled thin plate is provided on the main body of the strain gauge. A strain gauge provided adjacently is provided.

According to a third aspect of the present invention, in a strain gauge cut out of a rolled metal sheet obtained by rolling a metal whose resistance value changes by applying strain, a main body of the strain gauge cut out of the rolled metal sheet is attached. On the insulated plate, where the position of the main body of the strain gauge is cut out from the metal rolled sheet, the addresses in the column direction along the rolling direction of the metal rolled sheet, and the addresses in the row direction orthogonal to the rolling direction. A strain gauge is provided, wherein a display portion indicated by (1) and (2) is provided adjacent to the main body of the strain gauge.

[0008] In the invention according to claim 4, the strain gauge according to any one of claims 1 to 3, wherein a lot number indicating that the strain gauge is cut out from the same rolled metal sheet is displayed. The present invention provides a strain gauge characterized in that

According to a fifth aspect of the present invention, there is provided a strain detecting apparatus having a bridge circuit combining strain gauges cut out of a rolled metal sheet obtained by rolling a metal whose resistance value changes by application of strain. Provided is a strain detecting device having a bridge circuit in which a plurality of strain gauges having a display portion with the same display of a cutout position address in a column direction along a rolling direction are combined.

The invention according to claim 6 is the invention according to claim 5, wherein the strain gauges are cut out in the same column direction and are adjacent to each other in the column direction. Provided is a strain detection device.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the present invention will be described in detail with reference to the drawings. Foil strain gauges, several hundreds of the same strain gauge pattern is baked on a metal rolled thin plate of an insulating thin plate that is formed by rolling a metal rolled thin plate formed by rolling an ingot whose resistance temperature coefficient is adjusted, and the strain gauge is formed by photoetching. The formed and subsequently formed strain gauges are cut off individually for each insulating sheet.

The strain gauge adds a small amount of manganese and iron atoms to the nickel-copper alloy to minimize the fluctuation of the resistance value due to the temperature change. However, the segregation of atoms is present in the ingot, and the ingot is rolled. Not all parts of the foil can achieve a uniform temperature coefficient of resistance. FIG. 1 is a chart showing the variation of the temperature coefficient of resistance according to the position of the rolled nickel-copper alloy thin film. In FIG. 1, the rolling direction, that is, the longitudinal direction of the strip-shaped rolled thin film is defined as a Y direction,
Let the width direction be the X direction. As can be seen from FIG. 1, the distribution of the temperature coefficient of resistance is relatively uniform in the Y direction, which is the longitudinal direction of rolling, and has a large variation in the X direction, which is the width direction.

Therefore, in the present invention, a display unit for displaying positional information on the nickel copper alloy sheet surface at least in an area where a strain gauge is formed on the surface of the rolled nickel copper alloy sheet is provided. For example, as shown in FIG. 2, sections 2, 2,... For forming a strain gauge by dividing a nickel copper alloy thin plate 1 in a matrix form.
To form Then, a Roman address is assigned in the descending order in the X direction from the section located at the origin, and a numeric address is assigned in the ascending order in the Y direction. After the address is assigned, the position of the section is specified by the combination of the address in the X direction and the address in the Y direction.

When printing the strain gauge pattern on the rolled nickel-copper alloy sheet, the pattern is printed in the area specified above. In FIG. 2, a burn-in pattern is shown in a part of sections 2, 3 is a strain gauge body portion, and 4 is a lead terminal portion. At the time of this printing, the address is marked in a space adjacent to the main body portion 3 without interfering with the pattern formation. The mark 5 is a display section, which indicates a position where the main body of the strain gauge is cut out from the rolled metal sheet. This mark 5 does not disappear even when the strain gauge pattern is formed by selective etching or after the strain gauge is separated, for example,
Marking is performed by a forming method such as laser baking or selective etching. Then, a boundary line between the sections 2, 2, 2,... Is cut off to produce a single strain gauge.

[0015] Even after being separated, each strain gauge has a combination of an address in the X direction and a direction in the Y direction, from which of the rolled nickel copper alloy thin plate surface the corresponding strain gauge was cut out. Will be clearly shown. Strain gauges obtained from one nickel copper alloy sheet are handled as one lot group. Therefore, the lot number is additionally written in the mark 5.

As can be seen from FIG. 1, the distribution of the temperature coefficient of resistance is relatively uniform with respect to the Y direction which is the longitudinal direction of the rolling. At the indicated Roman character address, a strain gauge having the same character is selected, and four adjacent numbers are selected from among the strain gauges indicating the position in the row direction. To describe the address specifically, (A, 1), (A, 2),
The one having the addresses (A, 3) and (A, 4) is selected.

Strain gauges having these addresses are:
Since they have the same or very similar resistance temperature coefficients, forming a bridge circuit using these strain gauges can produce a circuit that does not lose its balance with temperature changes. In fact, in the case of a bridge circuit made of a conventional strain gauge, it was not possible to achieve a balance in a wide temperature range unless a temperature compensation circuit was provided in most of the bridge circuits. When the strain detection device was formed by combining the above, it was not necessary to provide a temperature compensation circuit with 80% of the bridge.

In the above-described embodiment, Roman characters are used for displaying addresses in the row direction, and arithmetic numerals are used for displaying addresses in the column direction. However, the present invention is not limited to such a display method. For example, if it is a code indicating that it is on the longitudinal direction (row direction) of rolling and a code indicating an existing position on the same row, what kind of code, such as a bar code, a binary number, or a combination thereof, is used. May be something.

As described above, the present invention has been described with reference to the above-described embodiment. However, various modifications and applications are possible within the scope of the present invention, and these modifications and applications are excluded from the scope of the present invention. is not.

[0020]

As described above in detail, according to the first aspect of the present invention, the main body of the strain gauge is provided on the insulating plate to which the main body of the strain gauge cut out of the rolled metal sheet is attached. Since a display portion indicating the position cut out from the rolled metal sheet is provided adjacent to the main body of the strain gauge, even if the strain gauges are cut off one by one, the strain gauge can be viewed even if the strain gauges are cut off one by one. From which part of the rolled metal sheet was cut off, so when trying to arrange strain gauges with the same temperature coefficient of resistance, it is extremely easy to refer to the indications on the display to see the same resistance temperature coefficient. Strain gauges with

In the invention according to the second aspect, when strain gauges having the same temperature coefficient of resistance are to be arranged, it is sufficient to collect those existing in the same rolling direction by looking at the display portion. According to the third aspect of the invention, when strain gauges having the same temperature coefficient of resistance are to be aligned, the display portions are located in the same rolling direction and are adjacent to each other at an address in a row direction orthogonal to the rolling direction. By gathering objects that have the same temperature coefficient of resistance, they can be aligned.

In the invention according to the fourth aspect, the lot number indicating that the same metal sheet was cut from the same rolled metal sheet is indicated on the display portion. Therefore, in the mass production of strain gauges, strain gauges cut from a plurality of lots are mixed. Even if you do so, it is very easy to select strain gauges with the same temperature coefficient of resistance by selecting the same lot.

According to the fifth aspect of the present invention, the bridge can be assembled with strain gauges having substantially the same temperature coefficient of resistance, so that there is no temperature compensation circuit or a small amount of compensation makes it possible to balance against temperature changes. Bridge circuit can be obtained. In the invention according to claim 6,
Since the strain gauges are cut out in the same column direction and the bridge circuits are formed using the strain gauges adjacent to each other in the column direction, a bridge circuit more balanced than the invention according to claim 5 is obtained. I can do it.

[Brief description of the drawings]

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a chart showing a variation state of a temperature coefficient of resistance according to a position of a rolled nickel-copper alloy thin film.

FIG. 2 is a front view showing an embodiment of the present invention.

[Explanation of symbols]

 1 Nickel-copper alloy thin plate 2 Section 3 Body part 4 Pull-out terminal 5 Mark

Claims (6)

[Claims] 1. A strain gauge cut out from a rolled metal sheet obtained by rolling a metal whose resistance value changes due to the application of strain, wherein the strain gauge is cut out from the rolled metal sheet on an insulating plate to which a main body of the strain gauge is adhered. A strain gauge, wherein a display portion indicating a position where the main body of the strain gauge is cut out from the rolled metal sheet is provided adjacent to the main body of the strain gauge. 2. A strain gauge cut out from a rolled metal sheet obtained by rolling a metal whose resistance value changes due to application of a strain, wherein the strain gauge is cut out from the rolled metal sheet on an insulating plate to which a main body of the strain gauge is adhered. A display portion indicating a position where the main body of the strain gauge is cut out from the rolled metal sheet at least in an address in a column direction along a rolling direction of the metal rolled thin sheet is provided adjacent to the main body of the strain gauge. A strain gauge characterized by the following. 3. A strain gauge cut out from a rolled metal sheet obtained by rolling a metal whose resistance value changes due to the application of strain, wherein the strain gauge is cut out from the rolled metal sheet and the main body of the strain gauge is adhered on an insulating plate. And a display section in which the position of the main body of the strain gauge cut out from the metal rolled sheet is indicated by an address in a column direction along a rolling direction of the metal rolled sheet and an address in a row direction orthogonal to the rolling direction. Is provided adjacent to a main body of the strain gauge. 4. The selected one of claims 1 to 3, wherein the strain gauge displays a lot number indicating that the piece has been cut from the same rolled metal sheet. Strain gauge. 5. A strain detecting device having a bridge circuit combining strain gauges cut out of a metal rolled sheet obtained by rolling a metal whose resistance value changes by applying a strain, wherein at least a row along the rolling direction of the metal rolled sheet A strain detecting device, comprising: a bridge circuit in which a plurality of strain gauges each having a display unit having the same cutout position address in the direction are displayed. 6. The strain detecting apparatus according to claim 6, wherein the strain gauges are cut out in the same column direction and are adjacent to each other in the column direction.