JP2000002634A - Thin plate gripping jig - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thin plate gripping jig for stably pinching a thin plate material as a test piece to be supplied for a tensile testing without damaging it. SOLUTION: The thin plate gripping jig is provided with a pair of pinching bodies 6a and 6b for pinching a test piece between opposing surfaces that form a pinching surface while being brought into contact with and separated from in opposite directions, a gutter-shaped recessed part 9a in a direction orthogonally crossing the pull direction of a test piece on the pinching surface of one pinching body, and at the same time, a projecting part 10 that causing the test piece to be pinched between the pinching surfaces to be deformed while being fitted to the outer-periphery surface so that it can enter the recessed part 9a on the pinching surface of the other pinching body. Especially, the projecting part 10 is achieved as the rod-shaped body 10 that is filled into the groove part 9b being provided on the other pinching surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin plate gripping jig which is mounted on a material testing machine and can stably hold a thin plate as a test piece to be subjected to a tensile test.

[0002]

2. Description of the Related Art In a tensile test, which is one of the material tests, a test piece is mounted between a pair of chucks provided in a material testing machine, and a tensile load is applied to the test piece by changing an opposing distance between the chucks. While adding, the tensile load and the elongation of the test piece are measured. At the same time, the breaking condition of the test piece is also examined. Incidentally, various kinds of test pieces are provided for this kind of tensile test. For example, not only a high-rigidity metal piece but also a test for an elastic member such as rubber are performed.

[0003]

A pair of chucks provided in a material testing machine are usually provided with a pair of holding bodies for holding one end of a test piece from both sides thereof.
Since the sandwiching of the test piece by such a pair of holding bodies is perpendicular to the direction of the tensile load applied to the test piece, the friction between the opposing holding surfaces of the holding body and the test piece is usually sufficient. It has been devised to increase it.

For example, as shown in FIG. 5, minute tooth shapes 3a, 3b are formed on holding surfaces 2a, 2b of a pair of holding bodies 1a, 1b which come into contact with and separate from each other and hold a test piece S therebetween. The tooth shapes 3a and 3b increase the contact friction with the test piece S, so that both sides of the test piece S can be firmly clamped. Alternatively, fine particles are made to adhere to the holding surfaces 2a and 2b. A device has been devised to increase the contact friction with the test piece S by these fine particles.

However, with such a structure, for example, when a thin test piece (thin plate material) S having a thickness of several μm to several tens μm is sandwiched and subjected to a tensile test, the tooth profile 3a,
The test piece S was damaged by 3b or the like, and there was a possibility that the test piece S was broken at the sandwiched portion due to the damage. Such a fracture is what is called a so-called chuck breakage, which not only disables the tensile test of the test piece S but also causes waste of the test piece S prepared in advance.

The present invention has been made in view of such circumstances, and an object of the present invention is to stably sandwich a thin plate material as a test piece to be subjected to a tensile test without damaging it. An object of the present invention is to provide a thin plate gripping jig capable of improving the efficiency.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, a thin plate gripping jig according to the present invention is brought into contact with and separated from each other in opposite directions so as to sandwich a test piece between opposing surfaces forming a clamping surface. A clamping body is provided, and for example, a trough-shaped recess extending in a direction intersecting with the pulling direction of the test piece is provided on a clamping surface of one of the clamping bodies, and the recess enters the recess on a clamping surface of the other clamping body. A ridge-shaped convex portion is provided, which extends in a direction intersecting the pulling direction of the test piece and deforms the test piece sandwiched between the holding surfaces along the outer peripheral surface thereof.

That is, according to the present invention, a convex portion for deforming a test piece made of a thin plate material sandwiched between a pair of holding bodies according to the outer peripheral surface thereof, the convex portion and the convex portion are deformed according to the convex portion. A concave portion serving as an escape portion for the test piece is provided on each of the holding surfaces of the pair of holding members. Then, when the test piece is sandwiched between the pair of holding members, the test piece is deformed in accordance with the outer peripheral surface of the convex portion, and the test piece is deformed by utilizing an increase in tensile resistance accompanying the deformation of the test piece. It is characterized in that the test piece is subjected to a tensile test by stably holding the test piece without damaging it.

For example, the concave portion is formed as a rounded hole with a bottom, and the convex portion is realized as a sphere filled in a round hole with a bottom provided at a position facing the concave portion. . Alternatively, as described in claim 2, the concave portion is realized as a gutter-shaped concave portion provided over a direction orthogonal to the pulling direction of the test piece, and the convex portion can enter the concave portion. It is characterized by being realized as a ridge-shaped convex portion provided in a direction perpendicular to the pulling direction of the test piece.

According to a third aspect of the present invention, the convex portion is realized as a rod-like body which is inserted into a groove provided on the other holding surface facing the concave portion. If the convex portion is realized as such a rod,
For example, by using a rod having a diameter corresponding to the thickness and rigidity of the test specimen, it is possible to stably hold various test specimens, respectively. For example, by inserting a non-slip material, stable holding can be achieved.

[0011]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a jig for holding a thin plate according to an embodiment of the present invention.

FIG. 1 is an external perspective view showing a schematic configuration of a thin plate gripping jig according to an embodiment. Reference numeral 5 denotes a chuck body, 6a,
Reference numeral 6b denotes a pair of holding bodies which are incorporated in the chuck body 5 so as to be able to approach and separate from each other. These holding bodies 6a, 6b
By inserting the base into the rail portion 5a of the chuck body 5, the base can move up and down in parallel with each other and come and go. Incidentally, the pair of holding bodies 6a and 6b are
By turning the screw 7 exposed on the side of the chuck body 5, a chucking mechanism (not shown) incorporated inside the chuck body 5 is actuated so as to be simultaneously connected to and separated from each other. Moved in the direction.

The holding bodies 6a and 6b have holding surfaces 8a and 8b opposed to the test piece S. One end of the test piece S is held by the holding surfaces 8a and 8b from both sides. I do. A pair of gutter-shaped recesses 9a, 9b extending in a direction perpendicular to the pulling direction of the test piece S are provided at positions of the holding surfaces 8a, 8b facing each other. In particular, a round bar body 10 serving as a convex portion is fitted into a concave portion (groove portion) 9b provided in the lower holding body 6b. The round bar body 10 includes, for example, a pair of holding members 6.
When the a and 6b are brought into contact with each other, they have a diameter such that they can enter a space formed between the recess 9a provided in the upper holding body 6a and the recess 9b. A plurality of types of round bar bodies 10 are prepared with different diameters.
The test piece S is selectively used as appropriate according to the specification.

The thin plate gripping jig having such a structure is used as a set of two to hold both ends of the test piece S, and is incorporated as a chuck portion in a dedicated thin plate tensile material testing machine (not shown). It is used as an auxiliary chuck (a jig) for a thin plate tensile test which is appropriately attached to a chuck portion of a universal material testing machine. In this case, for example, as shown in FIG.
The shaft 12 protruding from the rear surface of the universal material testing machine may be mounted on a chuck (not shown) of the universal material testing machine.

The holding of the test piece S by the thin plate gripping jig having such a structure is performed as follows. That is,
As shown in FIG. 2 (a), a test piece S made of a thin plate material is inserted from the tip side with the pair of holding bodies 6a and 6b opened, and the test piece S is inserted into the recess 9b. Rod 1
It is positioned between the holding members 6a and 6b beyond 0. In this state, by turning the screw portion 7 to operate the chucking mechanism and bringing the pair of holding members 6a and 6b closer to each other, the test piece S is held in the holding member 6 as shown in FIG.
a, 6b. At this time, the test piece S made of a thin plate follows the outer peripheral surface of the round bar body 10 and forms a curved portion locally as shown in FIG.
a, 8b.

As described above, the round bar body 10 is deformed in accordance with the outer peripheral surface thereof so as to be interposed between the holding members 6a and 6b (the holding surfaces 8a and 8b).
According to the test piece S interposed between the test pieces S, the frictional resistance of the test piece S in the tensile direction becomes extremely large in the deformed portion of the test piece S. Therefore, the test piece S is securely held without providing the above-described tooth shapes 3a, 3b on the flat portions (opposing surfaces) that form the main surfaces of the holding surfaces 8a, 8b, and the test piece S is firmly held in the pulling direction. And it can be stably held. Moreover, since it is not necessary to provide the tooth shapes 3a, 3b on the holding surfaces 8a, 8b, there is no possibility that the test pieces S are damaged by the tooth shapes 3a, 3b, and the test pieces S are broken at the chuck portion due to the scratches. There is no fear. Further, if the diameter of the round bar body 10 is changed according to the thickness and the type of the test piece S, the bending deformation amount of the test piece S can be changed thereby,
The test piece S can be appropriately deformed within a range that does not damage the test piece S, and can be firmly and stably sandwiched.

When the thickness of the test piece S is sufficiently large, for example, as shown in FIG. 2 (c), the round bar body 10 is removed, and the friction members 11, 11 having a tooth profile formed on one surface are removed. The test pieces S may be inserted into the concave portions 9a and 9b, respectively, and the test piece S may be sandwiched between the friction members 11 and 11. That is, by providing the round bar 10 detachably from the recess 9b, the round bar 10 having a different diameter can be selectively used, or the friction member 11 can be inserted into the recess 9b in place of the round bar 10. This makes it possible to appropriately hold test pieces S having various thicknesses and rigidities.

Here, one pair of holding members 6a and 6b
The concave portions 9a and 9b are provided, and one round bar body 10 is inserted into the concave portions 9a and 9b.
By inserting the round bar body 10 into each of these recesses, the test piece S can be deformed at a plurality of locations. By doing so, it is possible to further increase the frictional resistance in the tensile direction due to the deformation of the test piece S.

Each of the holding surfaces 8 of the pair of holding bodies 6a, 6b
a, 8b, a bottomed round hole 1 having a predetermined depth as shown in FIG.
2 may be provided to face each other, and the sphere 13 may be inserted into the round hole 12 so that the round hole 12 functions as a concave portion and the sphere 13 functions as a convex portion.
Further, when the specifications such as the thickness and rigidity of the test piece S to be tested are determined to some extent, for example, as shown in FIG. 4, the pair of holding bodies 6a and 6b A pair of concavo-convex curved surfaces facing each other may be formed, one of which may function as the concave portion 9a and the other may function as the convex portion formed by the above-described round bar body 10. Then, the test piece S may be deformed in accordance with these concave and convex curved surfaces, and the test piece S may be sandwiched between the concave and convex curved surfaces. However, in this case, it is desirable to use a dedicated thin plate sandwiching jig according to the specifications.

In the above-described embodiment, the round bar 10 serving as a convex portion is inserted into the concave portion (groove portion) 9b. However, it is of course possible to use a bar-shaped bar or the like having a semi-cylindrical cross section. In short, any shape may be used as long as it gives smooth deformation without damaging the test piece S and increases its frictional resistance. In addition, the present invention can be variously modified and implemented without departing from the gist thereof.

[0021]

As described above, according to the thin plate gripping jig according to the present invention, a concave portion is provided in one of a pair of holding bodies for holding a test piece from both sides, and the other holding body enters the recess. Since a convex portion is provided to deform the test piece sandwiched between the holding bodies following the outer peripheral surface,
The test piece can be stably sandwiched without being damaged by utilizing the increase in the tensile resistance accompanying the deformation of the test piece. Therefore, there is no possibility of breaking the test piece in the holding portion, and the test piece can be stably and reliably held and subjected to a tensile test, and the workability of mounting the test piece can be improved, and the test efficiency can be improved. Practically great effects, such as being achievable, can be obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a schematic configuration of a thin plate gripping jig according to an embodiment of the present invention.

FIG. 2 is a view for explaining an operation of holding a test piece by the thin plate gripping jig shown in FIG. 1;

FIG. 3 is a main part configuration diagram showing another embodiment of the thin plate gripping jig according to the present invention.

FIG. 4 is a main part configuration diagram showing still another embodiment of the thin plate gripping jig according to the present invention.

FIG. 5 is a diagram showing a configuration example of a chuck portion in a conventional tensile tester.

[Explanation of symbols]

 6a, 6b Holding body 8a, 8b Holding surface 9a, 9b Concave portion (groove) 10 Bar-shaped body (convex) 12 Round hole (concave) 13 Spherical body (convex) S Test piece

Claims (3)

[Claims] 1. A thin plate gripping jig for mounting one end of a thin plate material as a test piece mounted on a material testing machine and subjected to a tensile test from both sides thereof, wherein the jig is brought into contact with and separated from each other in opposite directions. A pair of holding bodies for holding the test piece between opposing surfaces forming a holding surface, a concave portion provided on the holding surface of one holding body, and a holding member provided on the holding surface of the other holding body and being held between the holding surfaces; A thin plate gripping jig comprising: a convex portion for deforming a test piece following the outer peripheral surface thereof. 2. The recess comprises a gutter-shaped recess provided in a direction orthogonal to a pulling direction of the test piece, and the convex portion is configured to be capable of entering the recess in a pulling direction of the test piece. The jig according to claim 1, comprising a ridge-shaped convex portion provided in a direction perpendicular to the thin plate. 3. The device according to claim 2, wherein the convex portion is formed of a rod-like body which is inserted into a groove provided on the other holding surface opposite to the concave portion provided on the one holding surface. The jig for thin plate gripping according to 1.