JPH1114521A - Tool for tension test - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it easy to set even an extremely thin test piece on a tension testing machine and to facilitate the setting of an extensometer. SOLUTION: This tool is equipped with couples of upper and lower gripping members 2A to 2D which clamp and hold the grip parts 1a and 1b at both the lengthwise ends of the test piece 1 made of an extremely thin material, received parts 5 which allow the side parts of the parallel parts of the test piece 1 to be exposed are formed at the side parts of those gripping members 2A to 2D, and the opposite end parts of the upper and lower gripping members 2A to 2B are connected in a separable state by a specific distance to form a cassette. The grip parts of the test piece 1 are clamped between the upper and lower gripping members 2A to 2B and fitted to the tension testing machine and the clamp part of the extensometer is clamped to the test piece 1 exposed in the recessed parts 5 to measure the extension quantity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tensile test device, and more particularly to a tensile test device for an extremely thin material.

[0002]

2. Description of the Related Art In general, a tensile test is performed to determine the relationship (Young's modulus) between the stress and strain of a material, and the elongation of the material is determined by calculating the change in the distance between two gauge points of the tensile test piece. Is measured by

In the measurement of the amount of elongation, when the thickness of the test piece is 2 mm or more, there is no problem in performing the measurement by using a tensile tester. It is difficult to measure the elongation directly with a tensile tester as usual in the case of such an ultra-thin material.

Therefore, conventionally, the amount of elongation is measured by the following method.

As shown in FIG. 6, a test piece a made of an ultra-thin material (shape conforming to JIS No. 13B) extends along both sides of a narrow parallel portion c at the center from grip portions b at both ends. ,
Detection pieces d and d separated at the longitudinal center of test piece a
Is formed, and when the test piece a is pulled by a tensile tester, the amount of change in the gap e between the ends of the detection pieces d and d is regarded as the change in light transmission, and the elongation is measured based on the change. (JP-A-5-80979).

[0006] A mark is marked on a narrow parallel portion a at the center of the test piece 1 having the shape shown in Fig. 2 by marking or the like, and a change in the mark interval is detected by a CCD camera to measure the amount of elongation. Means to do.

Means for measuring the amount of elongation using a strain gauge.

[0008]

However, in the means according to the above, since the detecting pieces d, d are thin and extremely thin, they fluctuate only by the action of the outside air or a slight vibration, and the elongation during the test. It is difficult to accurately measure the change in the gap e between the opposing ends of the detection pieces d, d due to the above.

[0009] Further, the above-mentioned means are all inferior in stability at the time of measurement, and it is extremely difficult to measure in units of 1 μm necessary for measurement of elongation.

Further, there is a problem that it is not easy to set an extremely thin test piece in a tensile tester by any of the above means.

On the other hand, if an existing extensometer is clamped at two points of the parallel portion 1a of the test piece 1 and the amount of elongation of the test piece 1 is detected and measured by the extensometer, a highly accurate result can be obtained. Although it can be obtained, the pinching part of the conventional extensometer to the test piece faces the pivot, and the test piece is pinched between its needle-like tips, so the pivot is used when pinching the test piece. The tips of the pivots tend to shift from each other, especially in the case of the above-mentioned ultra-thin test pieces, the test pieces are deformed if the tips of the opposing pivots are displaced, and they cannot be sufficiently clamped at the correct position, resulting in poor measurement. And inaccurate results.

[0012]

SUMMARY OF THE INVENTION The present invention makes it possible to easily set a test piece of a very thin material on a tensile tester and to measure an elongation amount accurately using an extensometer. It is an object of the present invention to provide a tensile test tool that performs the test.

As a means for solving the above problems, the present invention comprises a pair of upper and lower gripping members for holding the gripping portions at both ends in the longitudinal direction of a test piece made of an extremely thin material. A part is provided with a concave portion in which a side portion of the parallel portion of the test piece can be exposed, and a cassette formed by connecting the opposite ends of the upper and lower gripping members so as to be separated from each other over a predetermined distance,
An object of the present invention is to provide an extensometer which is constituted by a pair of knife edges in which a sandwiching portion sandwiched between two parallel portions of a test piece intersects each other, and which holds the test piece at an intersection of these knife edges.

Thus, even if the test piece is made of an extremely thin material, the test piece is held between the gripping members of the cassette, and the gripping member may be mounted on the tensile tester. It is easy to handle even an extremely thin test piece.

Further, since the portion of the extensometer to be clamped to the test piece has a cross-knife edge structure, there is no occurrence of poor clamping due to misalignment, and even an extremely thin test piece can be securely clamped. And highly accurate measurement of elongation can be performed.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments shown in the drawings.

FIG. 1 shows a cassette 2 according to the present invention. As shown in FIG. 2, gripping portions 1b at both ends in the longitudinal direction of a test piece 1 made of an extremely thin material having a shape conforming to JIS No. 13B are provided.
A pair of upper and lower gripping members 2A, 2B for holding the nip 1b
And upper and lower gripping members 2A, 2C, 2D.
The bolts 2C, 2B, and 2D can be fastened to each other by passing bolts through the bolt holes 3, 3. Also, a projection 4 for fitting and aligning the mating surface of the gripping members 2A, 2B or 2C, 2D on one side with the holes of the gripping members on the other side.
4 are provided.

The gripping members 2A, 2B and 2C, 2D
Are formed in the side portions of the parallel portion 1a so that the side portions of the parallel portion 1a can be exposed when the test piece 1 is clamped and held therebetween. .

Also, gripping members 2A, 2B and 2C, 2D
Brackets 6 and 6 are fixed to opposite ends of the bracket 6 with screws 7, 7..., And a pin 8 fixed to one bracket 6 is slidably inserted into the other bracket 6 and provided at the tip of the pin 8. The gripping members 2A, 2B and 2C, 2D are connected so as to be separated from each other over a required distance L (shown in FIG. 3). This connection means may be another means as long as it can move over the distance L.

On the other hand, an extensometer 10 for use in combination with the cassette 2 is a commercially available product (Linear Gauge Ed LGB2-105L or LGB2 manufactured by Mitutoyo Corporation).
-0105L), but its test piece 1
5 (A),
As shown in FIG. 2B, the test piece 1 is composed of knife edges 12 and 12 which are orthogonal to each other, and the test piece 1 is held at the intersection P of the blade portions of the knife edges 12 and 12. . Reference numeral 13 denotes a holding screw.

The gripping members 2A, 2B and 2C, 2D
It is preferable to make rough the area where the gripping portions 1b, 1b of the test piece 1 are placed on the opposing surface in order to ensure the holding of the test piece 1 in the clamping pressure.

Next, the operation will be described.

Prior to the test, the bolts connecting the gripping members 2A, 2B and 2C, 2D are removed, and the opposing ends of the gripping members 2C, 2D on one side are brought into contact with or close to each other, so that the upper surface (the alignment) is The test piece 1 is placed on the (surface), the gripping members 2A, 2B on the other surface are superimposed thereon, and bolts are passed through the bolt holes 3, 3 and fastened. As a result, the test piece 1 has its gripping portions 1b, 1b having gripping members 2A, 2C and 2B, 2D.
A portion of the parallel portion 1a of the test piece 1 is held in the recesses 5, 5,... Of the gripping portions 2A to 2D.

The cassette 2 holding the test piece 1 in this manner
Are gripped by a general tensile tester, and a clamping portion of the extensometer 10 is positioned at a reference point of the test piece 1 exposed in the recesses 5, 5,... Of the gripping members 2A to 2D. Inserting the test piece 1 between the knife edges 12 and 12 of the holding portions 11 and 11 and tightening the screw 13, the test piece 1 at the intersection P of the blade portions of the knife edges 12 and 12. Is pinched.

When the tensile tester is operated in this manner, the gripping members 2A, 2C and 2B, 2D of the cassette 2 are relatively pulled in a direction away from each other, and a tensile force acts on the test piece 1.

At this time, the elongation of the test piece 1 is detected by the separation between the holding portions 11 and 11 of the extensometer 10, and the displacement is detected by a linear encoder or the like, and the elongation in microns is measured. Can be.

When the test piece 1 has such a thickness that the cassette 2 is not required, the extensometer 1 is used directly without the cassette.
0 can be attached to measure the amount of elongation. In this case, however, since the test piece 1 is held at the intersection P of the blade portions of the knife edges 12, 12, a holding failure due to a positional shift occurs as in the case of pivoting. Nothing.

[0028]

As described above, according to the present invention, even if the thickness of a test piece for which a tensile test is performed is an extremely thin material of a micron unit, it can be set in a tensile tester via a cassette. Therefore, it is possible to easily and reliably mount the apparatus to the test machine, and it is possible to significantly improve the work efficiency. In addition, when the test piece is set in the tensile tester, the test piece is sandwiched between the holding members of the cassette and stored, so that even if the test piece is extremely thin, there is no risk of damaging the test piece, and the test can be performed with high precision. Can do it.

On the other hand, since the holding portion of the extensometer is constituted by a pair of intersecting knife edges, even if the test piece is extremely thin, it can be held with one touch without causing displacement and stable. A measurement can be made.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of a cassette according to the present invention.

FIG. 2 is a plan view of a test piece.

FIG. 3 is a plan view showing a state where a test piece is sandwiched between cassettes and an extensometer is set.

FIG. 4 is a front view of FIG. 3;

FIGS. 5A and 5B are exemplary views of a holding portion of an extensometer.

FIG. 6 is a plan view of an ultra-thin test piece showing a conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Test piece 1a Parallel part 1b Gripping part 2 Cassette 2A-2D Gripping member 3 Bolt hole 4 Projection 5 Depression 6 Bracket 7 Screw 8 Pin 9 Head 10 Extensometer 11 Clamping part 12 Knife edge 13 Clamping screw

Claims (3)

[Claims] 1. A pair of upper and lower gripping members for clamping and holding gripping portions at both ends in the longitudinal direction of a test piece made of an ultrathin material,
A concave portion is provided on the side of these gripping members so that the side of the parallel portion of the test piece can be exposed, and the upper and lower gripping members are opposed to each other at a predetermined distance so as to be separated from each other by a predetermined distance. Then, the gripping portion of the test piece is sandwiched between the upper and lower gripping members and attached to a tensile tester, and the amount of elongation is measured by clamping the clipping portion of an extensometer to the test piece exposed in the concave portion. A tensile test tool characterized by being obtained. 2. An extensometer for detecting an amount of elongation of a test piece, said holding means having a holding portion capable of being held at two parallel portions of a test piece made of an ultrathin material. A tensile test device comprising a pair of intersecting knife edges, wherein a test piece is sandwiched between intersections of these knife edges. 3. A pair of upper and lower gripping members for clamping and holding gripping portions at both ends in the longitudinal direction of a test piece made of an ultrathin material,
Provided on the side of these gripping members is a concave portion in which the side of the parallel portion of the test piece can be exposed, and a cassette formed by connecting the opposite ends of the upper and lower gripping members so as to be separated from each other over a predetermined distance, A clamping portion sandwiched between two parallel portions of the test piece is constituted by a pair of knife edges crossing each other, and has an extensometer configured to clamp the test piece at an intersection of these knife edges. Tensile testing tool.