JPH0827225B2 - Tensile bending tester - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a tensile bending tester capable of performing a tensile test and a bending test.

B. Prior art and problems to be solved by the invention Conventionally, the tensile test and the bending test of a test piece are separately performed by dedicated test machines, and there is no test machine capable of performing both tests. It was For this reason, a test in which a bending load is applied while a tensile load is applied to the test piece cannot be performed.

A technical object of the present invention is to enable a tensile load and a bending load to be simultaneously applied to a test piece.

C. Means for Solving the Problems The present invention provides a pair of grips for gripping a test piece, a tension load mechanism that drives the grip to apply a tensile load to the test piece, and a bending load to the test piece. It is applied to a tensile bending tester having a bending load mechanism. Then, a restraint member that restrains a predetermined position between the gripping positions of the pair of grips of the test piece so as to form a support point when the test piece is bent,
The above problem is solved by including a load detector that detects a tensile load applied to the test piece by the tensile load mechanism and by configuring the bending load mechanism as follows.

That is, the bending load mechanism applies a bending load to the test piece by swinging at least one of the grips around a fulcrum with the tensile load acting on the test piece being held at a predetermined value by the tensile load mechanism. It is composed of a rocking mechanism.

D. Action The grip is driven by the tensile load mechanism to apply a tensile load to the test piece. The bending load mechanism applies a bending load while applying a tensile load to the test piece by swinging at least one of the grips around a fulcrum while the tensile load mechanism is still connected to the grip.

E. Embodiment An embodiment of the present invention will be described with reference to FIG.

FIG. 1 shows the construction of a tensile bending tester according to the present invention,
(A) is a front view, (b) is the figure seen from the bb line. A pair of machine pillars 2 are erected on the table 1, and a yoke 3 is laid horizontally on the upper part thereof. The crosshead 4 is screwed into a pair of screw rods (not shown) provided upright inside the machine pillar 2, and the crosshead 4 is moved up and down by the rotation of the screw rods. A load cell 5 is fixed to the lower surface of the crosshead 4, and a cylindrical bearing guide 6 is screwed to cover the load cell 5, and a load rod 7 connected to the load cell 5 is guided by a linear bearing 70. The inside of 6 is slidable in the vertical direction. An upper grip 8 is attached to the lower end of the load rod 7.

31, 32 are rollers, and the roller 31 is a roller holder 33f, 3
The roller 32 is rotatably attached to one end of 3r and to one end of roller holders 34f and 34r (34r is not shown).
Each roller holder has a long hole HL (first
It is screwed to the outer wall of the bearing guide 6 by a bolt 42 through the figure (b)), so that the pair of rollers 31, 32
Are held beneath the upper gripper 8 as shown. The rollers 31 and 32 are for forming a fulcrum P when the test piece TP is bent by sandwiching and restraining the substantially intermediate position of the test piece TP, and the hole HL of each roller holder is an elongated hole. The reason is that the rollers 31 and 32 are positioned in the vertical direction.

On the other hand, on the table 1, as shown in FIG. 1 (b), the motor 21 and the rotary load frame holder 22 are fixed, and
A pulley 23 is attached to the output shaft 21a of 21. At the top of the holder 22, a rotary shaft with a pulley 24 attached to one end
25 penetrates rotatably via a bearing 41, and a timing belt 26 is wound around the pulleys 23 and 24. Therefore, the rotating shaft 25 can be rotated by the driving force of the motor 21.

The other end of the rotary shaft 25 is connected to the center of the bar 27, and both ends of a semi-cylindrical rotary load frame 28 having a radius R are fixed to both ends of the bar 27, respectively. Therefore, the rotation of the rotary shaft 25 causes the bar 27 and the rotary load frame 28 to integrally rotate in the directions A and B shown in FIG. A lower grip 29 is attached to the center of the rotary load frame 28, and
When the bar 27 is horizontal as shown in FIG. 7A, the axes of the lower grip 29 and the upper grip 8 coincide with the load axis. Both ends of the flat plate-shaped test piece TP are respectively held by the two grippers 8, 29.

 Next, the operation of the embodiment will be described.

In performing the tensile bending test, the test piece TP is mounted on the tester without the rollers 31 and 32 attached. That is, with the lower grip 29 at the position indicated by the solid line in the figure (position facing the upper grip 8), the upper and lower grips 8, 29 are caused to grip the test piece TP. Next, the rollers 31 and 32 are attached, and the fulcrum P for bending the test piece TP is formed. That is roller 3 at the tip
Roller holders 33f, 33r and 3 with 1,32 attached respectively
The 4f and 34r are positioned and mounted on the bearing guide 6, and the pair of rollers 31 and 32 clamp the test piece TP on the center line 1 of the rotary shaft 25 (FIG. 1 (b)).

When a pair of screw rods (not shown) are rotated to raise the crosshead 4 in this state, a tensile load is applied to the test piece TP via the upper gripping tool 8 and the test piece TP extends. As the pair of rollers 31, 32 rotate in accordance with the extension, the rollers 31,
Even if it is sandwiched by 32, the elongation of the test piece TP is not hindered. Here, the tensile load acting on the test piece TP is detected by the load cell 5, and based on the detection result, for example, a constant load test or the like is performed.

When the motor 21 is rotated in a predetermined direction by a predetermined amount under this tensile load, the rotation of the pulley 23 attached to the output shaft 21a is transmitted to the pulley 24 via the timing belt 26, and the rotating shaft 25 rotates. As a result, the bar 27 and the rotary load frame 28 rotate, for example, in the direction A of FIG. 1A by a predetermined amount, and the lower grip 29 swings around the fulcrum P to a position indicated by a chain double-dashed line, for example. . Due to the swing of the lower grip 29, a bending load acts on the test piece TP, and the test piece TP bends around the fulcrum P.

In this state, when the motor 21 is rotated in the opposite direction to the above, the bar 27 and the rotary load frame 28 are rotated by a predetermined amount, for example, in the B direction in FIG.
29 swings in the opposite direction and the test piece TP bends in the opposite direction to the above. Thus, the motor 21 is repeatedly rotated in the forward and reverse directions to bend the test piece TP in both directions.

Alternatively, the bending load may be applied by driving the motor 21 while the crosshead 4 is stopped. In this case, a tensile load acts on the test piece TP due to the bending of the test piece TP, but a test method in which this is detected by the load cell 5 and the motor 21 is controlled so that this tensile load becomes constant is also possible. Is.

In the configuration of the above embodiment, the screw rod and the crosshead 4 serve as a tensile load mechanism, the rollers 31, 32 and the roller holders 33f, 33r, 34f, 34r serve as restraining members, the motor 21, the pulleys 23, 24, and the rotation. The shaft 25, the timing belt 26, the bar 27, and the rotary load frame 28 form a bending load mechanism.

As shown in FIG. 2, a torque sensor is attached to the rotary shaft 25.
The torque sensor 51 may be attached to detect a bending load, and a predetermined test (for example, a constant bending load) may be performed based on the detected bending load.

The members forming the fulcrum P are not limited to the rollers 31 and 32. Further, although the upper grip 8 is driven to apply the tensile load to the test piece TP, the lower grip 29 may be driven to apply the tensile load. Furthermore, the mechanism for applying a bending load to the test piece TP is not limited to the above-mentioned one, and for example, the upper gripping tool 8 is swung or both gripping tools are used.
You may make it oscillate 8 and 29 together and give a bending load.

F. Effect of the Invention Since the present invention is configured as described above, it is possible to realize a test in which a bending load is applied to a test piece while a predetermined tensile load is applied. Further, since the portion of the test piece between the gripping positions by the gripping tool serves as a bending fulcrum, the test piece breaks at the boundary between the gripping portion and the non-grasping portion of the test piece (so-called chuck breakage (either of the test pieces). This tends to occur when the grip portion is used as the bending fulcrum), and the test accuracy is improved. Further, since both ends of the test piece are gripped and fixed by the gripping tool, it is not necessary to tighten the test piece when forming the bending fulcrum at the intermediate position. Therefore, a compressive load due to tightening does not act on the fulcrum forming portion of the test piece, and a pure bending test can be performed.

[Brief description of drawings]

1 and 2 show an embodiment of the present invention, and FIG. 1 (a) is a front sectional view of a tensile bending tester according to the present invention.
(B) is a partial cross-sectional view showing the right half when (a) is cut along the line bb, and FIG. 2 is a partial cross-sectional view showing a modified example. 4: Crosshead, 8: Upper grip 21: Motor, 23, 24: Pulley 25: Rotating shaft, 26: Timing belt 27: Bar, 28: Rotating load frame 29: Lower grip, 31, 32: Roller 33f, 33r, 34f: Roller holder P: Support point, TP: Test piece

Claims (1)

[Claims] 1. A pair of grippers for gripping a test piece, a tension load mechanism for driving the gripper to apply a tensile load to the test piece, and a bending load mechanism for applying a bending load to the test piece. In a tensile bending tester having: a restraint member for restraining a predetermined position between the gripping positions of the test piece by the pair of grips so as to form a fulcrum when the test piece is bent; and the tensile load mechanism. With a load detector for detecting the tensile load applied to the test piece by, the bending load mechanism, in a state in which the tensile load acting on the test piece by the tensile load mechanism is held at a predetermined value. A tensile bending tester, comprising at least one swinging mechanism that swings around one of the supporting points to apply a bending load to the test piece.