JPH0633402Y2 - Multi-point bending test jig - Google Patents

Description

[Detailed Description of the Invention] A. Field of Industrial Application The present invention relates to a multipoint bending test jig used for bending tests of brittle materials such as ceramics and cemented carbide.

B. Conventional Technology For example, when performing the bending test of the brittle material described above with a three-point bending test jig or a four-point bending test jig, the amount of deformation until the test piece breaks is extremely small. If there is a slight manufacturing error in the test piece such as non-parallelism of the top and bottom surfaces of the test piece having a rectangular cross section, correct measurement data cannot be obtained and there is a problem in that the measurement varies. Therefore, conventionally, such a problem has been solved by a jig as shown in FIGS. 10 to 12.

In FIGS. 10 to 12 showing the three-point bending test jig, a pair of support pin positioning grooves 81a parallel to each other is provided on the support 81.
And a test piece positioning groove 81b orthogonal to these grooves 81a,
A load pin positioning groove 81c orthogonal to the test piece positioning groove 81b is formed. A pair of support pins 82 are respectively immovably fitted in the support pin positioning grooves 81a in the width direction, and a test piece TP is fitted in the test piece positioning groove 81b in the width direction while being bridged over the pair of support pins 82. It is immovably fitted. Further, the load pin 83 is fitted in the load pin positioning groove 81c so as to be swingable in the vertical plane in the longitudinal direction and immovable in the width direction in a state of being in line contact with the upper portion of the test piece TP. Further, the intermediate member 84 and the intermediate pin 85 are fitted on the load pin 83 in the upper portion of the test piece positioning groove 81b.

A guide member 86 is fitted to the support tool 81, and a load tool 87 is slidably inserted into a through hole 86a formed in the upper part of the support tool 81, and the lower surface of the load tool 87 is in line contact with the intermediate pin 85. is doing.
88 is a load ball.

The three-point bending test jig configured as described above is attached to a tester (not shown), and a load tool is applied via a ball 88 by a load rod.
When a load is applied to 87, a bending load acts on the test piece TP via the intermediate pin 85, the intermediate member 84, and the load pin 83. Since the load pin 83 can swing in the vertical plane in the longitudinal direction, even if the upper and lower surfaces of the test piece TP are not parallel,
83 is inclined so that it always comes into line contact with the upper surface of the test piece TP, which prevents an undesired load from acting on the test piece TP.

C. Problems to be Solved by the Invention However, in the above configuration, since the support pin 82 cannot swing, when the test piece TP is twisted, the test piece TP does not come into line contact with the support pin 82. Point contact, which results in a test piece
Accurate measurement is difficult because undesired load acts on TP or load concentrates on the point contact part.

An object of the present invention is to provide a multi-point bending test jig that solves the above problems.

D. Means for Solving the Problems In the present invention, a test piece is laid horizontally on a pair of support members, and a load member is tested so as to come into contact with at least one position on the upper surface of the test piece opposite to the support member. The present invention is applied to a multi-point bending test jig which is arranged orthogonal to a piece and transmits a load in the load axial direction to a load member via a load tool to perform a bending test. The above-mentioned problem is that the load member is fixed between the pair of support groove portions extending in the first direction for fixing the pair of support members and the pair of support groove portions and substantially parallel to the groove portions. And a test piece groove portion that extends in a second direction substantially orthogonal to the pair of support groove portions and that places the test piece on the pair of support members. The above-mentioned problems can be solved by constructing the supporting member of (1) as follows.

That is, the load member is formed with a straight side portion that extends in a direction orthogonal to the test piece and is in line contact with a part of the test piece, and a convex arc-shaped portion that is in contact with the load tool. , A straight side portion that contacts the test piece and a convex arc-shaped portion that is swingably fitted in a vertical plane in the first direction in a concave arc-shaped groove formed in the bottom portion of one of the support groove portions. .

E. Action The load member is orthogonal to the test piece and its straight side is in line contact with part of the test piece, and the convex arcuate part is in contact with the load tool. It is possible to swing in a vertical plane in the direction of 1. Further, since the convex arcuate portion of one of the support members is fitted into the concave arcuate groove formed in the bottom portion of the load groove portion, it can be similarly swung in the vertical plane in the first direction. Therefore, even when the test piece is twisted, it is possible to prevent the straight sides of the load member and the support member from constantly making line contact with the test piece and applying an undesired load.

F. Embodiment An embodiment in which the present invention is applied to a three-point bending test jig will be described with reference to FIGS. 1 to 6.

(I) Configuration of Example FIG. 1 is a front sectional view of a three-point bending test jig 100, FIG. 2 is a sectional view taken along the line II-II of FIG. 3, and FIG. FIG. 3 is a sectional view taken along line III-III in FIG.

The support 10 includes a large-diameter cylindrical portion 11 and a medium-diameter cylindrical portion 12 in order from the bottom.
And a small-diameter cylindrical portion 13 are integrally laminated, and a circular recess 11a is formed on the bottom surface of the large-diameter cylindrical portion 11. Third
As shown in the figure, the medium-diameter cylindrical portion 12 has fulcrum positioning grooves (supporting groove portions) 12a, 12 extending in the x direction at the left and right ends in the figure.
b is formed. Further, a test piece positioning groove (test piece groove portion) 13a orthogonal to the fulcrum positioning grooves 12a, 12b is provided in the y direction from the upper portion of the small diameter cylindrical portion 13 to the upper portion of the medium diameter cylindrical portion 12, and the test piece positioning is performed. The load punch positioning groove (load groove portion) 13b orthogonal to the groove 13a at the center is y.
Is extended in the direction. That is, the fulcrum positioning groove 12a,
The direction in which 12b extends is x, and the direction in which the test piece positioning groove 13a extends is y.

When performing a 3-point bending test on the test piece TP, the fulcrum positioning groove 12
A pin-shaped fulcrum (support member) 31 as shown in FIG. 4 (b) is fitted in a with the movement in the y direction restricted.
A fulcrum (support member) 32 having a shape as shown in FIG. 4 (c) or (d) is fitted into the fulcrum positioning groove 12b in a state where movement in the y direction is restricted. The lower surface of the fulcrum 32 has a convex arc shape, and this convex arc-shaped portion is swingably fitted into a concave arc-shaped groove formed at the bottom of one fulcrum positioning groove 12b. Therefore, the fulcrum 32 can swing in a vertical plane in the longitudinal direction (x direction). The upper surface of the fulcrum 32 is a straight side portion that comes into line contact with the lower surface of the test piece. Further, the test piece TP is fitted into the test piece positioning groove 13a in a state in which the test piece TP is laid over the fulcrums 31 and 32 and the movement in the x direction is restricted.
A load punch (load member) 33 as shown in FIG. 4 (a) is fitted in the load punch positioning groove 13b in a state where the load punch 33 is orthogonal to the test piece TP and its movement in the y direction is restricted. The upper surface of the load punch 33 has a convex arc shape, and the convex arc portion is slightly projected from the upper surface of the small-diameter columnar portion 13 to make line contact or point contact with a load tool 50 described later. Also load punch
The lower surface of 33 is a straight side portion that contacts a part of the test piece TP. In this way, the straight side of the load punch 33 contacts a part of the test piece TP in a state orthogonal to the test piece TP, and the convex arcuate part makes a line contact or point contact with the load tool, so the upper surface of the test piece TP. Load punch 33 in the longitudinal direction (x direction) according to the shape of
It will oscillate in the vertical plane, and the straight side will always come into line contact with the test piece TP.

A cylindrical guide member 20 is fitted in the support tool 10, and the lower surface thereof is in contact with the upper surface of the large-diameter cylindrical portion 11 of the support tool 10. A load tool 50 is vertically slidably inserted into a through hole 21 formed in the center of the upper portion of the guide member 20, and the load punch 33 described above is provided.
Supported above. Further, a ball 60 for loading is provided in a conical recess 51a formed in the upper center of the head 51 of the loading device 50.
Is fitted.

The test jig 100 configured as described above is mounted on a tester as shown in FIG. 5, for example.

In FIG. 5, a pair of screw rods 72 erected on a table 71 is provided with a yoke 73 on the upper portion thereof and a cross head 74 is screwed so as to be able to move up and down. A load cell 75 for load detection is provided at the center of the lower surface of the crosshead 74, and a load shaft 76 is connected to this. At the center of the table 71, a test jig 100 is installed with its bottom surface recess 11a fitted to a positioning protrusion (not shown) on the table, and the load shaft 76 and the load tool 50 are coaxially opposed to each other.

(II) Operation of Example In performing the bending test, first, the fulcrums 31, 32, the test piece TP, and the load punch 33 are set in each groove as described above, and the supporting tool 10 is set.
The guide member 20 is put on the cover. When the screw rod 72 is rotated and the crosshead 74 is lowered, a downward load is applied to the load tool 50 by the load shaft 76 via the ball 60, whereby a bending load acts on the test piece TP via the load punch 33. . The applied load is detected by the load cell 75 and recorded by a recorder (not shown).

Here, when the test piece TP is twisted as shown in FIG. 6 (a), for example, one fulcrum 31 and the test piece TP are in line contact as shown in FIG. 6 (b), but the other The fulcrum 32 and the test piece TP are in point contact with each other as shown by the solid line in FIG. 6 (c).
When a load acts on the test piece TP via the load punch 33, the fulcrum 32 swings as shown by the broken line in FIG.
Almost line contact with TP. Therefore, the applied load is TP
It works evenly and gives accurate measurement data. on the other hand,
In the conventional example, since the fulcrum corresponding to the fulcrum 32 does not swing, a load is applied to the test piece TP with point contact as shown by the solid line in Fig. 6 (c), and an undesired load is applied to the test piece TP. At the same time, the load concentrates on the point contact part, and accurate measurement data cannot be obtained.

Further, in this case, the load punch 33 also oscillates as shown in FIG. 6 (c), but since the upper portion thereof is formed in an arc shape, the load load is transmitted while always making point or line contact with the load tool 50. .

When the test piece TP ruptures, the load punch 33 is groove 13b due to its own weight.
Although the load 50 falls to the lowermost end, the flange 51 of the head of the load 50 comes into contact with the upper surface of the guide member 20 and stops.

(III) Other Embodiments The present invention can also be applied to a 4-point bending test jig as shown in FIGS. 7 to 9.

As shown in FIGS. 7 to 9, a pair of load punch positioning grooves extending from the upper portion of the small diameter cylindrical portion 13 to the upper portion of the medium diameter cylindrical portion 12
13b is formed, and a pair of load punches 33 as shown in FIG. 4 (a) are in line contact with the upper surface of the test piece TP.
In addition, it is fitted in a state where movement in the y direction is restricted. The upper portions of the load punches 33 make point contact with the lower surface of the load tool 50 and can swing in the vertical plane in the x direction as described above depending on the shape of the test piece TP. Since both of the pair of load punches 33 are formed in an arcuate shape, even if they swing in a vertical plane in the x-direction, both punches always make point or line contact with the load tool 50. The load load can be evenly input to the test piece TP from the punch 33, and an undesired load is prevented from acting. Therefore, accurate measurement data can be obtained. The movement of the fulcrum 32 is the same as in the case of the 3-point bending test jig.

G. Effect of the Invention Since the present invention is configured as described above, the load member and one of the supporting members oscillate and are always in line contact with the test piece, which results in an undesired load even when the test piece is twisted. Is prevented, and accurate measurement data is always obtained.

[Brief description of drawings]

1 to 6 illustrate one embodiment of the present invention.
FIG. 1 is a front sectional view of a 3-point bending test jig, and FIG.
II-II line sectional view, FIG. 3 is a III-III line sectional view of FIG.
FIG. 4 (a) is a perspective view showing the load punch, and FIG. 4 (b).
~ (D) is a perspective view showing three examples of fulcrums, Fig. 5 is a front view showing a case where a three-point bending test jig is mounted on a testing machine, and Fig. 6 (a) is a perspective view of a twisted test piece. Fig. 6 (b),
(C) is a view showing a contact state between a pair of fulcrums and a test piece, and FIGS. 7 to 9 show other embodiments in which the present invention is applied to a four-point bending test jig, and FIG. 1 to FIG. It is a figure corresponding to FIG. 10 to 12 are views showing a conventional example corresponding to FIGS. 1 to 3. 10: Support tool 12a, 12b: Support point positioning groove 13a: Test piece positioning groove 13b: Load punch positioning groove 20: Guide member, 31, 32: Support point 33: Load punch, 50: Load tool 100: 3-point bending test jig , TP: Test piece

Claims (1)

[Scope of utility model registration request] 1. A test piece is horizontally mounted on a pair of support members, and a load member is arranged orthogonally to the test piece so as to contact at least one location on an upper surface of the test piece opposite to the support member.
In a multi-point bending test jig for performing a bending test by transmitting a load in the load axis direction to a load member via a load tool, a pair of support groove portions extending in a first direction in which the pair of support members are fixed. And at least one load groove portion that extends between the pair of support groove portions and substantially parallel to the groove portions and positions the load member, and a second groove that is substantially orthogonal to the pair of support groove portions.
Of the test piece extending in the direction orthogonal to the test piece, the test piece groove portion for placing the test piece on a pair of supporting members and extending in the direction perpendicular to the test piece. And a convex arcuate portion with which the load is contacted are formed, and a straight side portion that contacts the test piece and a bottom portion of the one support groove portion are formed on one of the supporting members. A multi-point bending test jig characterized in that a concave arc-shaped groove is formed with a convex arc-shaped portion fitted to be swingable in a plane perpendicular to the first direction.