JP2505084Y2 - Bending tester - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bending tester capable of detecting a deformation amount of a test piece by applying a bending load to the test piece.

[0002]

2. Description of the Related Art In a bending tester of this type, for example, as shown in FIG. 5, both ends of a test piece TP are placed on a pair of receivers 61 constituting a lower test jig, and an upper test jig is placed. The surface of the test piece TP is pressed by 62 to apply a bending load to the test piece TP, and the deformation amount of the deformation of the test piece TP due to the bending load is measured by the displacement meter 6
This is detected in 3. The spindle (detector) 63a of the displacement meter 63 is configured to contract according to the deformation of the test piece TP, and the contraction amount is output as the test piece deformation amount.

[0003]

However, in measuring the deformation amount of the test piece, the deformed test piece T is usually used.
Maximum displacement of P (displacement of the pressing part in the upper test jig)
d is measured. Therefore, there is no problem if the upper test jig 62 and the spindle 63a have the same axis as shown in FIG. 5, but when the axes of both are deviated as shown in FIG. 6, for example. However, the contraction amount of the spindle 63a becomes smaller than the maximum displacement amount by d1 shown in the figure, and an accurate displacement amount cannot be measured.

An object of the present invention is to provide a bending tester capable of accurately measuring the amount of displacement even if the axes of the upper test jig and the detector of the displacement gauge are slightly deviated.

[0005]

SUMMARY OF THE INVENTION The present invention provides a bending tester for applying a bending load to a test piece and detecting the bending displacement of the test piece from the displacement of a detector that follows the deformation of the test piece. Applied to. Then, the detection plate clamped between the back surface of the test piece and the detector, and the detection plate is guided so as to be displaced in the load axis direction with the test piece contact surface of the detection plate orthogonal to the load axis. A guide mechanism is provided to solve the above problems.

[0006]

The detecting plate is displaced in the load axis direction following the deformation of the test piece due to the bending load. At that time, since the test piece contact surface of the detection plate is maintained in a state orthogonal to the load axis, the movement amount of the detector contact surface of the detection plate becomes equal to the maximum displacement amount of the test piece over the entire surface. Therefore, as long as the detector is in contact with the detection plate, the displacement of the detector becomes the maximum displacement of the test piece even if the axis of the upper test jig and the axis of the detector are deviated.

[0007]

1 to 4 show an embodiment of the present invention. FIG. 1 is a front view showing a test jig of a bending tester according to the present invention. Reference numeral 10 is the table 5 of the material testing machine body.
1 is a lower test jig consisting of a base 11 fixed on 1 and a pair of test piece receivers 12L and 12R provided upright on the base 11. Both ends of the back surface are placed and supported. Reference numeral 40 denotes an upper test jig that is fixed to a crosshead (not shown) of the tester body. Apply a bending load.

A displacement measuring mechanism 20 for detecting the amount of deformation of the test piece TP is provided between the pair of receiving members 12L, 12R. FIG. 2 is an enlarged view of the displacement measuring mechanism 20,
The plate 21 fixed on the base 11 has a pair of columns 2
2 is erected, and both ends of the bracket 24 are vertically slidably penetrated through the column 22 via a coil spring 23. A pair of guide shafts 25 are erected on the bracket 24, and the bracket 2 mounted horizontally on the upper end of the support column 22.
A pair of linear bearings 27 are fixed to 6 and the guide shaft 25 is vertically slidably passed through these linear bearings 27.

Both ends of a circular detection plate 28 are fixed to the upper end of each guide shaft 25. This detection plate 28
Is urged upward by a spring 23 via a pair of guide shafts 25 and a bracket 24, and its upper surface abuts the rear surface of the test piece TP. When the detection plate 28 is pressed downward, the detection plate 28 is lowered integrally with the pair of guide shafts 25 and the bracket 24 against the spring force of the spring 23. Here, the detection plate 28 is wider than the test piece TP as shown in FIG.

A displacement gauge 30 of, for example, a differential transformer is attached to one of the columns 22 via a clamp member 29 between the upper and lower brackets 24 and 26. The displacement meter 30 is composed of a main body 30a and a spindle (detector) 30b which is vertically expandable and contractable with respect to the main body 30a, and an attaching portion 30c protruding from the peripheral surface of the main body 30a has the above-mentioned support 22
It is gripped and supported by the clamp material 29 fixed to the.
The spindle 30b is urged in the extension direction by a spring (not shown), and its tip is brought into contact with the lower surface of the recess of the detection plate 28, and an electric signal corresponding to the contraction amount of the spindle 30b is output from the main body 30a. It

Next, the operation of the embodiment will be described with reference to FIG. In performing the bending test of the test piece TP, first, the test piece TP is placed on the pair of receivers 12L and 12R, and the back surface of the test piece TP is brought into contact with the upper surface of the detection plate 28. The zero point adjustment of the displacement meter 30 is performed with the spindle 30b of the displacement meter 30 in contact with the lower surface of the detection plate 28, and then the upper test jig 40 is lowered via the crosshead. As a result, the upper test jig 40 presses the test piece TP downward, and a bending load is applied to the test piece TP. This bending load deforms the test piece TP as shown in FIG.
The back surface of the presses the detection plate 28 downward. The pressing force causes the detection plate 28, the guide shaft 25, and the bracket 24 to integrally move downward (displace in the load axis direction) against the biasing force of the spring 23.

Here, since the detection plate 28 is biased upward by the spring 23, it follows the deformation of the test piece TP and descends while always contacting the back surface of the test piece. Further, since the pair of guide shafts 25 slide in the linear bearing 27 to guide the lowering of the detection plate 28, the detection plate 28 always maintains a horizontal state (a state orthogonal to the load axis) without tilting. . Therefore, the displacement amount of the lower surface of the detection plate 28 becomes equal to the maximum displacement amount of the test piece TP over the entire surface, that is, the displacement amount of the pressing portion of the upper test jig 40.

When the detection plate 28 descends, the spindle 30b, which abuts the lower surface of the detection plate 28, contracts with respect to the displacement meter main body 30a by the same amount as the detection plate 28, and a signal corresponding to the contraction amount is output as the deformation amount of the test piece. It As described above, since the displacement amount of the lower surface of the detection plate 28 is equal to the maximum displacement amount of the test piece TP over the entire surface, for example, as shown in FIG.
0 and the axis of the spindle 30b are deviated, that is, regardless of where the spindle 30b is in contact with the lower surface of the detection plate, the displacement amount of the spindle 30b is always the maximum displacement amount of the test piece TP, and the accurate test piece The amount of deformation can be detected.

After the test is completed, when the test piece TP is removed and the upper test jig 40 is raised, the urging force of the spring 23 causes the bracket 24, the guide shaft 25, and the detection plate 28 to rise integrally to the initial position. Accordingly, the spindle 30b of the displacement gauge 30 is also expanded by a spring (not shown) and returns to the state of FIG.

In the configuration of the above embodiment, the guide shaft 2
5 and the linear bearing 27 constitute a guide mechanism.

Although an example using a differential transformer type displacement meter has been shown above, another type of displacement meter may be used as long as it has a structure for detecting the displacement amount of the detector. Further, the configuration of the guide mechanism is not limited to that of the embodiment as long as it displaces the detection plate in the same posture. For example, the spring 23 may not be provided, and the detection plate may be clamped between the test piece and the spindle by the upward biasing force of the spindle 30b. In addition, a spring and a guide mechanism are provided between the upper test jig and the detection plate, the upper surface of the detection plate is brought into contact with the back surface of the test piece by the urging force of the spring, and the detection plate is moved through the guide mechanism. You may make it guide to a load axis direction in the state orthogonal to a load axis.

Further, the shape of the detection test is not limited to the circular shape. Furthermore, although the example in which the upper tester jig is lowered to load the test piece is shown, the lower tester jig and the displacement measuring device may be integrally raised to load the test piece. Again 3
Although the point bending tester has been described, the present invention can be applied to a four point bending tester that presses two points on the surface of the test piece. Furthermore, although the tester in which the test piece is loaded in the vertical direction has been described, it may be loaded in the horizontal direction.

[0018]

EFFECTS OF THE INVENTION According to the present invention, a detection plate is provided between the back surface of the test piece and the detector, and the detection plate is placed in a state where the test piece contact surface of the detection plate is orthogonal to the load axis. Since it is designed to displace in the load axis direction, the displacement of the detector contact surface of the detection plate is the maximum displacement of the test piece over the entire surface, and the axis of the upper test jig and the detector axis are not aligned. Also, it becomes possible to accurately measure the deformation amount of the test piece.

[Brief description of drawings]

FIG. 1 is a front view showing a main part of a bending tester according to an embodiment of the present invention.

FIG. 2 is an enlarged view of a displacement detection mechanism.

FIG. 3 is a top view showing a test piece and a detection plate.

FIG. 4 is a diagram for explaining the operation of the embodiment.

FIG. 5 is a diagram illustrating a conventional bending test method.

FIG. 6 is a diagram illustrating a conventional problem.

[Explanation of symbols]

 10 Lower Tester Jig 12L, 12R Test Specimen Receptor 20 Displacement Measuring Mechanism 23 Coil Spring 25 Guide Axis 27 Linear Bearing 28 Detecting Plate 30 Displacement Gauge 30b Spindle 51 Table 40 Upper Tester Jig TP Test Specimen

Claims (1)

(57) [Scope of utility model registration request] 1. A bending tester that applies a bending load to a test piece and detects the bending displacement of the test piece from the displacement of a detector that follows the deformation of the test piece. And a guide mechanism for guiding the detection plate so as to be displaced in the load axis direction in a state where the test piece contact surface of the detection plate is orthogonal to the load axis. Characteristic bending tester.