JP2566142Y2 - Tensile testing machine - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tensile tester provided with a test piece gripper for gripping a small test piece with wedge-shaped grip teeth.

[0002]

2. Description of the Related Art FIG. 4 shows a conventional test piece gripper for gripping a test piece with wedge-shaped gripping teeth. In FIG. 1, reference numeral 1 denotes a chuck frame, in which a space portion 4 gradually expanding from an inlet side 2 to a back side 3 along a load axis X is formed, and a pair of wedge-shaped gripping teeth 5a, 5b ( 5 may be slidably accommodated in a wedge surface 6 in the chuck frame 1. Hold the chuck frame 1 with the teeth 5
When pulled up, the gripping teeth 5 close, grip the previously interposed test piece, and open when pulled down to release this test piece.

[0003]

However, such a conventional test piece gripping tool has the following problems. (1) When the chucking margin of the test piece is small, when the chuck frame 1 is pulled up, both gripping teeth 5a and 5b may be inclined in a C-shape as shown by the phantom line. If the gripper is attached to the tester in this state and a tensile test is performed, slippage occurs between the test piece and the gripping surface of the gripping teeth 5, and an accurate tensile test cannot be performed. (2) When the slip occurs, the gripping surface may be damaged by the test piece.

An object of the present invention is to provide a tensile tester capable of performing a tensile test by holding a specimen while maintaining a pair of gripping teeth substantially parallel.

[0005]

The present invention will be described with reference to FIG. 1 showing an embodiment. In the present invention, a space portion 14 which gradually expands from an inlet side 12 to a back side 13 along a load axis is provided. A chuck frame 10 having a wedge surface 15 formed on an inner surface thereof to be formed;
It is opened and closed when moved in the direction of the load axis X with respect to the chuck frame 10, and is applied to a tensile testing machine having a test piece gripper having a pair of wedge-shaped gripping teeth 16A and B for gripping and releasing the test piece TP. You. A tightening means 20 for tightening the test piece TP inserted into one end of the pair of gripping teeth 16A, B, and a parallel adjusting means for adjusting the pair of gripping teeth 16A, B in parallel when tightening the test piece TP. 2
The clamping means 20 includes a pair of parallel gripping teeth 16A and 16B for clamping the test piece TP on the chuck frame 10, and then performs a closing movement of the pair of gripping teeth 16A and B by a wedge effect. The test piece TP is tightened to allow it, and the parallel adjusting means 21 and 24 are provided with a pair of gripping teeth 16.
The above object is achieved by allowing A and B to be readjusted to allow a closing motion after being mounted on the chuck frame 10.

[0006]

When the test piece TP inserted into one end of the pair of gripping teeth 16A, B is tightened by the tightening means 20, the pair of gripping teeth 16A, B are adjusted in parallel by the parallel adjusting means 21, 24. After the pair of gripping teeth 16A, B which are adjusted in parallel and tighten the specimen TP are mounted on the chuck frame 10, the parallel adjusting means 21, 24 are readjusted, and the pair of gripping teeth 16A, B by the wedge effect are adjusted. To allow the closing movement of The tightening by the tightening means 20 allows the closing movement.

In the section of the means for solving the above-mentioned problem and the operation which explain the configuration of the present invention, the drawings of the embodiments are used to make the present invention easy to understand. However, the present invention is not limited to this.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. In FIGS. 1 to 3, reference numeral 10 denotes a pair of chuck frames which are attached to a tensile tester so as to face each other. A wedge surface 15 is formed such that a space portion 14 gradually expanding from the inlet side 12 to the back side 13 along the load axis X is formed. Reference numerals 16A and 16B denote a pair of gripping teeth, which are wedge-shaped portions 16 slidably received on the wedge surface 15 in the space portion 14.
1A and 1B, and protrusions 162A and B connected to one ends of the wedge-shaped portions 161A and 161B, respectively. Protrusion 162
A wave-shaped gripping surface 162a for gripping the test piece TP is formed on the mutually facing side surfaces of A and B.

Reference numerals 20 and 21 denote a pair of gripping teeth 16 respectively.
A tip of the bolt 20 is screwed into a projection 162B of one gripping tooth 16B, and a head is a bolt storage hole 162b formed in the projection 162A of the other gripping tooth 16A. Has been inserted into the play. The shoulder 20a of the head of the bolt 20 is engaged with the step of the bolt storage hole 162b. The tip of the bolt 21 is screwed into a wedge-shaped portion 161B of one of the gripping teeth 16B and fixed by a lock nut 23. The head of the bolt 21 is the other gripping tooth 16
A bolt receiving hole 16 formed in wedge-shaped portion 161A of A
1a. 24 is the other gripping tooth 16A
This is an adjust nut for adjusting the parallelism of the gripping teeth 16A and B by contacting the wedge-shaped portion 161A. Reference numeral 25 shown in FIGS. 2 and 3 is a front lid for closing the entrance of the space portion 14 of the chuck frame 10 to prevent the gripping teeth 16A, 16B from falling off.

In order to grip the test piece TP with such a test piece gripping tool, the upper end of the test piece TP is placed between the projections 162A, B of the pair of gripping teeth 16A, B without being assembled to the chuck frame 10. Is inserted as shown in FIG. Next, the test piece TP is tightened by the holding surface 162 a of the protrusion 162 by tightening the bolt 20. At the same time,
The nut 24 is rotated while the wedge-shaped portion 161 of the gripping tooth 16A is in contact with the adjustment nut 24, and the gripping teeth 16A and 16B are adjusted in parallel. The same operation is performed on the lower end of the test piece TP, and the wedge-shaped portions 161A and 161B of each pair of gripping teeth 16A are accommodated in the space portions 14 of the upper and lower chuck frames 10 as shown in FIG.

Next, the joint 1 of the two chuck frames 10 will be described.
1 is fixed to a tensile tester. Here, the adjust nut 24 is slightly loosened, and the entrance of the space 14 is closed by the front lid 25. Next, the joint 1 of the chuck frame 10
When 1 is pulled by the tester, the wedge-shaped portions 161A and 161B between the bolts 20 and 21 slide down the wedge surface 15 of the chuck frame. At this time, the bolt 20 is loosely inserted into the bolt storage hole 162b of the gripping tooth 16A, the bolt 21 is loosely inserted into the bolt storage hole 161a, and a gap is formed between the wedge-shaped portion 161A and the nut 24. Therefore, the gripping teeth 16A and 16B can be moved in the closing direction. On the other hand, the wedge-shaped portion 161
A and B act on the end portion 15a of the wedge surface 15 as a fulcrum, and a force to rotate in the clockwise direction and the counterclockwise direction respectively acts.
A and B are adjusting nuts 2 as indicated by phantom lines in FIG.
Incline until it touches 4. At this time, a force acts in the opening direction on the gripping surface 162a of the test piece TP, but the tip of the bolt 20 is screwed into the projection 162B of the gripping tooth 16B, and the shoulder 20a of the head is formed at the step of the bolt storage hole 162b. , The movement of the protrusions 162A, B in the opening direction is restricted. Therefore, the gripping surface 162a does not move in the opening direction, and thereby the wedge-shaped portion 16
The wedge action by the end 15a of the wedge surface 15 effectively works on 1A and 1B, and the test piece TP is reliably gripped by the gripping surfaces 162a of the protrusions 162A and B. On the other hand, when the test piece becomes thin during the test, the wedge-shaped portions 161A and 161 slide on the wedge surface 15, and the distance between the gripping teeth 16A and 16B becomes narrow. In this state, the wedge-shaped portions 161A and 161B are rotated by the clockwise and counterclockwise directions around the end 15a of the wedge surface 15 as a fulcrum. Try to tilt as shown by. At this time, the interval between the wedge-shaped portions 161A and 161B has already been narrowed, and the wedge-shaped portions 161A and 161B are almost in contact with the adjustment nut 24. Therefore, the gripping teeth 16A, B are opened, and the test piece TP does not come off from the gripping teeth 16A, B.

As described above, the protrusions 1 of the gripping teeth 16A and 16B are provided.
The test piece TP inserted into 62A, 62B is tightened by the bolt 20, and at this time, the pair of gripping teeth 16A, B are adjusted in parallel by the bolt 21 and the adjust nut 24. After the grip nuts 16A and 16B are mounted on the chuck frame 10 and the adjust nut 24 is loosened,
Due to the wedge effect of the wedge surface 15, the movement of the gripping teeth 16A, B in the closing direction is allowed in accordance with the allowance for the adjustment nut 24 to be loosened, and the gripping teeth 16A do not incline in the shape of a triangle as in the prior art. , B, the test piece TP is reliably gripped by the gripping surface 162a provided at one end of the test piece TP. For this reason, it is possible to securely grip even a small allowance for gripping the test piece TP, and the gripping surface 162a of the test piece TP and the gripping teeth 16 is provided.
No slippage occurs between them. As a result, an accurate tensile test can be performed. Also, gripping surface 1
62a can also be prevented from being damaged.

In the configuration of the above embodiment, the bolt 20
Is the tightening means, the bolt 21 and the adjust nut 24
Constitute parallel adjustment means, respectively.

[0014]

According to the present invention, when the test piece inserted into one end of the pair of gripping teeth is tightened by the tightening means via the gripping teeth, the pair of gripping teeth are adjusted in parallel by the parallel adjusting means. After the pair of gripping teeth are mounted on the chuck frame, the parallel adjusting means can be adjusted again to close the pair of gripping teeth by a wedge effect. And the specimen can be securely held by one end of the gripping tooth. For this reason, even a small specimen can perform an accurate tensile test without chuck slippage, and can also prevent the gripping surface of the gripping teeth from being damaged.

[Brief description of the drawings]

FIG. 1 is an enlarged sectional view of a main part showing an embodiment of a test piece gripper according to the present invention.

FIG. 2 is a front view showing a state in which the test piece gripping tools shown in FIG. 1 are attached to a tensile tester in pairs.

FIG. 3 is a view taken in the direction of arrows II-II in FIG. 2;

FIG. 4 is a front sectional view showing a conventional test piece gripper.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Chuck frame 12 Inlet side 13 Back side 14 Space part 15 Wedge surface 16A, 16B Gripping tooth 20, 21 Bolt 24 Adjust nut

Claims (1)

(57) [Scope of request for utility model registration] 1. A chuck frame having a wedge surface formed on an inner surface so as to form a space gradually expanding from an inlet side to a depth side along a load axis, and housed in the space, In a tensile tester having a test piece gripper having a pair of wedge-shaped gripping teeth that opens and closes when moved in the load axis direction and grips and releases a test piece, A tightening means for tightening the test piece inserted into one end of the gripping tooth; and a parallel adjusting means provided on the gripping tooth for adjusting the pair of gripping teeth in parallel when tightening the test piece. The tightening means mounts a pair of parallel gripping teeth for tightening the test piece on the chuck frame, and then closes the test piece so as to allow the pair of gripping teeth to close by a wedge effect. The tension tester, wherein the parallel adjusting means is re-adjustable to allow the closing movement after the pair of gripping teeth are mounted on the chuck frame.