JPH0742114Y2 - Material testing machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to a material testing machine for performing a tensile test on a sample such as a thread or a wire.

[Prior Art] To perform a tensile test on a sample such as a thread or a wire, first attach a weight or the like to the sample, apply an initial load, grasp the sample with a grasping tool with the deflection of the sample removed, and then The test is conducted by applying a tensile load to the.

[Problems to be Solved by the Invention] As described above, in the conventional sample holding device, since the weight is attached to the sample and the sample is gripped after the initial load is applied,
There was a problem that the work efficiency was poor because the work of attaching the weight etc. was time-consuming.

Therefore, an object of the present invention is to provide a material testing machine equipped with a sample gripping device capable of efficiently and easily gripping a sample by removing the deflection of the sample when performing a tensile test on a sample such as a yarn.

[Means for Solving the Problems] The present invention adopts the following configurations in order to solve the above problems.

That is, the material testing machine according to the present invention is a material testing machine equipped with a gripping device for a sample such as a thread or a wire, and a pair of gripping tools for gripping a sample and a distance between the gripping tools are grasped. A moving means for moving in the unfolding direction, a suppressing means for applying a predetermined force in a direction for suppressing the movement of the gripping tool by the moving means, and a detection when the gripping tool moves beyond the suppression pressure of the suppressing means And a control means for stopping the driving of the moving means in response to a detection signal from the detecting means.

[Operation] When the sample is gripped by the gripping tool while the flexure is generated, the gap between the gripping tools is widened by the moving means and the flexure of the sample is removed. At this time, the moving means widens the gap between the gripping tools against the restraining force of the restraining means, so that a tensile force as an initial load acts on the sample. When the pulling force exceeds the suppression force, that is, when the gripping tool moves beyond the suppression force, the displacement is detected by the detection means. The control means outputs a drive stop command for the moving means in response to a signal from the detecting means. When the movement of the gripping tool is stopped, the sample is grasped in a state where the deflection is removed and the initial load is applied.

[Embodiment] FIGS. 1 (a), (b), (c), and (d) are a plan view, a front view, and left and right side views showing a configuration of an embodiment of the present invention. The sample gripping device of this material testing machine is configured to grip a sample 4 such as a thread or a wire between the fingers 2a and 3a provided on the pair of sample grippers 2 and 3 and operated by air pressure. One sample gripping tool 2 is fixedly mounted on a base 5 of the apparatus main body by a mounting tool 6. The other sample gripping tool 3 is attached to a fixture 12 that is attached via a joint 11 to a rectilinear motor 10 that moves along a rail 7 provided on a base 5, and is used to move the rectilinear motor 10. Move along the guide 13 accordingly. Sample holder 3
By moving, the distance L between the grips changes.

The finger 2a of the fixed sample holder is rotatably supported around the rotary shaft 15, but is normally pressed against the stopper 17 by the leaf spring 16 and constrained so as not to rotate toward the stopper 17 side. There is. Further, a displacement detector is provided near the finger 2a. The displacement detector 19 detects the moment when a force is applied to the finger 2a and the finger 2a begins to rotate along the guide 20 to the opposite side of the stopper 17 against the pressing force of the leaf spring 16. The output signal from the displacement detector 19 is input to control means (not shown). When the displacement of the finger 2a is detected, a driving stop signal is output from the control means to the linear motor 10 to stop the motor. on the other hand,
The finger 3a of the sample holder 3 on the moving side has no special component such as 2a, and is opened and closed in the direction of arrow A so as to hold or open the sample by air pressure. Finger 2a
For holding the sample, open and close it in the direction of arrow B.

The gripping operation of the sample in the embodiment apparatus configured as above will be described. First, the sample 4 is held by the fingers 2a and 3a of the grippers 2 and 3 without worrying about the deflection. Next, the linear motor 10 is driven to slide on the rail 7, and the sample gripper 3 is moved along the guide 13 in the direction in which the distance L between the grippers increases. The sample gripping tool 2 is fixed, and the flexure of the sample 4 is removed as the gripping tool 3 moves, so that the sample 4 gradually receives a tensile force as an initial load. When this tensile force is applied to the sample 4, a force to rotate the finger 2a of the sample grip 2 around the rotary shaft 15 toward the grip 3 is applied.

However, since the pressing force of the leaf spring 16 is also acting on the finger 2a, the finger 2a does not rotate while the pressing force overcomes the tensile force. When the sample gripper 3 moves further and the tensile force acting on the sample 4 exceeds the suppression force of the leaf spring 16, the finger 2a starts to rotate. When the finger 2a starts rotating, the detector 19 detects this movement. The detection signal from the detector 19 is input to the drive control means of the linear motor 10. The control means receives the detection signal and outputs a drive stop command to the straight-ahead type motor 10. The linear motor 10 stops, and the movement of the sample holder 3 stops. As a result, sample 4
Will be gripped with the deflection removed and the initial load applied. A tensile test may be performed on this sample.

As described above, according to the material testing machine equipped with the sample gripping device of the present embodiment, it is not necessary to attach a weight or the like to the sample to remove the deflection and to apply an initial load, which is efficient and simple. The sample can be gripped. In addition, the initial load applied to the sample is the spring 16 that suppresses the movement of the fingers.
It can be adjusted by changing the strength of. Furthermore, when an automatic carrier is used for the apparatus of this embodiment, it can be conveyed to the tensile tester in a state where the bending is removed, the tensile test is started immediately, the cycle time of the test can be shortened, and the test can be performed efficiently. You can

In the above embodiment, the gripping tool is of the pneumatic type, but may be of the suction type. Further, although one of the sample gripping tools is moved, it is also possible to move both of the gripping tools to remove the deflection. A gripping tool moving mechanism may be provided between the sample gripping tool and the mounting tool, and the tensile force may be detected at this portion.

[Effect of the Invention] As is apparent from the above description, according to the material testing machine equipped with the sample gripping device according to the present invention, the operation of attaching a weight or the like to the sample is not required, and the flexure of the sample can be performed efficiently and easily. The sample can now be gripped with the initial load removed.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 (a), (b), (c), and (d) are a plan view, a front view, and a side view showing the configuration of an embodiment of the present invention. 2, 3 ... Sample holder, 2a, 3a ... Fingers, 4 ...
… Sample, 10 …… Linear motor (grasping tool moving means), 16
...... Leaf spring (suppression means), 19 …… Detector

Claims (1)

[Scope of utility model registration request] 1. A material testing machine comprising a device for gripping a sample such as a thread or a wire, comprising a pair of grippers for gripping the sample.
A moving means for moving the grips in a direction of increasing the distance between the grips, a suppressing means for applying a predetermined force in a direction for suppressing the movement of the grips by the moving means, and a pressure exceeding the suppressing force of the suppressing means. A material testing machine comprising a sample gripping device comprising a detection means for detecting the movement of a gripper when the gripper moves, and a control means for stopping the driving of the movement means in response to a detection signal from the detection means.