JPS6135947Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement in a test piece gripping tool used when performing a tensile test on a tubular test piece.

FIG. 1 shows a conventional gripper.

In the figure, 01 is a tubular test piece, into which a mandrel 02 is inserted from the end. 03 is a grip that surrounds the test piece 01 with grip teeth 03a, and has a tapered surface 3b on the outer circumferential surface that becomes narrower toward the center of the test piece 01 (downward in the figure).

Note that 04 is the tapered surface 3b of the grip 03.
A chuck having a tapered surface that engages with the chuck,
It is fixed to the rod of a tensile tester (not shown).

When the grip 03 is pressed toward the center of the test piece 01 by a hydraulic cylinder (not shown) installed in the gap between the grip 03 and the chuck 04, the test piece 01 is Deposit 0
2 and the grip teeth 03a of the grip 03.

In this state, when the chuck 04 is pulled by the rod, a tensile load is applied to the test piece 01 and a test is conducted.

However, if the test piece 01 is particularly thin or soft, the grip teeth 03a of the grip 03
For reasons such as the specimen 01 biting into the specimen 01 or the stress being concentrated on the gripping teeth 03, the specimen 01 could not be ruptured at the center of the specimen 01, which should cause rupture or elongation. In many cases, the parts broke off, and test data could not be obtained in some cases.

The present invention eliminates this drawback, and is a tensile test gripping tool that connects a tubular test piece and a holder that applies a load to the test piece. A column-shaped tensile jig has a tapered part that widens from the end toward the center of the test piece, and the inner surface has a tapered part that engages with the tapered part of the tensile jig, and the outer surface of the test piece A ring-shaped core that abuts the inner wall and is divided into a plurality of parts on a plane including the axis, a pressing member that presses the core toward the center of the test piece, and a pressing member that clamps the outer periphery of the end of the test piece. It is a gripping tool consisting of an outer cylinder.

An embodiment of the present invention shown in FIG. 2 will be described below.

In the figure, 1 is a tubular test piece, into which a columnar tension jig 6 is inserted from the end. One end of the tensile jig 6 is fixed to a rod of a tensile tester (not shown), and the end inserted into the test piece 1 has a tapered part that expands toward the tip, that is, toward the center of the test piece 1. 6a is formed.

Reference numeral 3 denotes a core disposed in the gap between the test piece 1 and the tensile jig 6, which has a tapered part 3a on its inner surface that engages with the tapered part 6a, and whose outer surface has a line parallel to the axis. It has a cylindrical surface formed,
and is divided by a plane containing the axis.

The core 3 is pressed toward the center of the test piece 1 by a pressing member 4 positioned by a nut 5 that is screwed into the tension jig 6, and is pressed toward the center of the test piece 1. An outer cylinder 2 is disposed on the outer surface to restrict expansion of the test piece 1 in the circumferential direction.

That is, by turning the nut 5, the pressing member 4 moves and enters the depth of the test piece 1. At this time, the pressing member 4 pushes the core 3 and causes its tapered surface 3a to slide on the tapered surface 6a of the tensioning jig 6, thereby expanding the core 3 in the semi-mechanical direction.

Therefore, the test piece 1 has an expanded core 3 on its inside.
On the other hand, the outer side is tightly attached by the outer cylinder 2,
A tensile load due to the rod acts on the test piece 1 due to the frictional force.

In this way, by using the gripping tool in this example, the test piece 1, which is a thin-walled tube, a copper alloy, etc., does not break from the gripping part, and fracture data between gauge points that satisfy the test conditions can be obtained. It becomes possible to obtain.

[Brief explanation of drawings]

Figure 1 is a partially cutaway side view of a conventional gripping tool;
The figure is a partially cutaway side view of a gripping tool showing an embodiment of the present invention. 1: Test piece, 2: Outer cylinder, 3: Core, 3a: Tapered part, 4: Pressing member, 5: Nut, 6: Tension jig, 6a: Tapered part.

Claims (1)

[Scope of utility model registration request] In a tensile test gripping tool that connects a tubular test piece and a holder that applies a load to the test piece,
A column-shaped tensile jig having a tapered part that widens from the end of the test piece toward the center, which is inserted from the end of the test piece, and a taper that engages with the tapered part of the tensile jig on the inner surface. a ring-shaped core whose outer surface abuts the inner wall of the test piece and is divided into a plurality of parts along a plane including the axis; and a pressure force that presses the core toward the center of the test piece. A gripping tool for a tensile test, comprising a member and an outer cylinder that clamps the outer periphery of the end of the test piece.