JP7167803B2 - material testing machine - Google Patents

Description

The present invention relates to a material testing machine.

During a material test in which a test force is applied to a test piece until it breaks, an image at the time of breakage may be obtained by photographing the test piece with a video camera during the material test. When ceramic materials such as glass are used as test pieces, they have not been photographed in the past because they fracture at a very high speed. (see Patent Document 1).

Moreover, when conducting a material test, the test is performed by a method conforming to various regulations such as JIS. A material test for ceramics such as glass is stipulated in ASTM C1499-01, which is a standard established by the American Society for Testing and Materials (ASTM, now ASTM International).

FIG. 5 is an explanatory view schematically showing the aspect of the "glass ring bending test" specified in ASTM C1499-01.

When performing this test, a test piece 100 made of a glass plate is placed on a support ring 102 having an annular projection. A material test is performed by bringing a load ring 101 having an annular projection into contact with the surface of the test piece 100 and applying a test force from the load rod 104 to the load ring 101 via the ball 103. be done.

JP 2012-189321 A

When performing such a glass ring bending test, etc., there is a demand for photographing the contact portion of the test piece 100 with the load ring 101 and the inner region of the support ring 102 where breakage occurs, using a high-speed video camera. There is However, in the glass ring bending test, since these areas are surrounded by the load ring 101 and the support ring 102, there is a problem that these areas cannot be photographed.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and is capable of photographing the test piece in the region within the rings even when a test force is applied to the test piece by a pair of rings. The purpose is to provide a material testing machine.

A first aspect of the present invention comprises a first pressing member having a first ring that contacts a first surface of a plate-shaped test piece, and a second surface of the test piece opposite to the first surface. a second pressing member having a second ring having an inner diameter different from that of the contacting first ring, wherein the first pressing member holds the test piece between the first ring and the second ring; In the material testing machine that applies a test force to the test piece by moving the second pressing member and the second pressing member in a direction approaching each other , and a through hole is formed in a region inside the second ring in the pedestal portion, and a drive for moving the first pressing member in a direction approaching the second pressing member and an imaging unit that is located on the side of the second pressing member when viewed from the test piece and captures an image of the region in the second plane of the test piece through the through hole .

According to the first aspect of the present invention, even when a test force is applied to the test piece by the pair of rings, the through hole formed in the region inside the second ring in the second pressing member is used. By doing so, it is possible to perform imaging of the specimen in the region within the ring.

1 is a schematic diagram of a material testing machine according to an embodiment of the present invention; FIG. 2 is a schematic diagram showing an upper jig 10 and a lower jig 20 together with a mirror 30 and a high-speed video camera 40; FIG. 3 is a cross-sectional view of a lower jig 20; FIG. 3 is a plan view of a lower jig 20; FIG. It is explanatory drawing which shows typically the aspect of the ring bending test of glass.

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram of a material testing machine according to an embodiment of the invention.

In this material testing machine, a test piece 100 is arranged in a test space of a material testing machine main body surrounded by a crosshead 51, a base 52, and a pair of covers 53 erected on the left and right sides of the base 52. , the glass ring bend test specified in ASTM C1499-01 as a material test. The test piece 100 is composed of a glass plate. The test piece 100 is arranged between an upper jig 10 arranged on the lower surface of the crosshead 51 and a lower jig 20 arranged on the base 52, as will be described later. 1, illustration of a high-speed video camera 40, which will be described later, is omitted.

Both ends of the crosshead 51 are provided with nut portions (not shown) that are screwed with a pair of screw rods arranged in covers 53 erected on the left and right sides of the base 52 . The crosshead 51 moves vertically as the pair of screw threads are synchronously rotated by the drive of the motor provided in the base 52 . A test force is applied to the test piece 100 by lowering the crosshead 51 .

FIG. 2 is a schematic diagram showing the upper jig 10 and lower jig 20 together with the mirror 30 and the high-speed video camera 40. As shown in FIG. 3 is a cross-sectional view of the lower jig 20. FIG. 4 is a plan view of the lower jig 20. FIG. 2, side cross sections of the upper jig 10, the lower jig 20 and the mirror 30 are shown.

The upper jig 10 includes a first pressing member 12 having an upper ring 11 as a first ring capable of coming into contact with the first surface of the test piece 100 . The first pressing member 12 is fixed to a support member 13 on which a metal sphere 14 is placed and connected to a frame 15 . A lifting member 16 fixed to the crosshead 51 shown in FIG. 1 is connected to the frame 15 . The lifting member 16 is movable with respect to the frame 15 between a position indicated by a solid line and a position indicated by a phantom line in FIG.

On the other hand, the lower jig 20 includes a second pressing member 22 having a lower ring 21 as a second ring capable of coming into contact with the back surface, which is the second surface of the test piece 100 . The inner diameter of the lower ring 21 is larger than the inner diameter of the upper ring 11 . The second pressing member 22 is fixed by four screws 24 to the upper plate 23 of the lower jig 20 . The top plate 23 forms a box-shaped body with an open front surface together with a pair of side plates 25 and a bottom plate 26 . A through hole 29 is formed in the second pressing member 22 in a region inside the lower ring 21 . The shape of the through hole 29 , that is, the shape of the horizontal cross section of the through hole 29 is a circle having the same diameter as the inner diameter of the lower ring 21 . Through holes corresponding to the through holes 29 are also formed in the upper plate 23 .

A mirror 30 supported by a support member 31 is arranged inside the lower jig 20 . This mirror 30 is located on the opposite side of the second pressing member 22 to the test piece 100 , that is, on the lower side of the second pressing member 22 , and the reflective surface of the mirror 30 is 45 degrees with respect to the back surface of the test piece 100 . are arranged in a state of intersecting with a crossing angle of A high-speed video camera 40 is arranged in front of the mirror 30 . This high-speed video camera 40 captures an image of the area within the lower ring 21 of the test piece 100 via the mirror 30 and the through hole 29 formed in the second pressing member 22 .

In the material testing machine having the configuration as described above, the operation of performing a glass ring bending test on the test piece 100 made of a glass plate will be described.

When conducting the ring bending test of glass, first, the upper jig 10 is retracted upward with respect to the lower jig 20 by raising the crosshead 51 . At this time, the elevating member 16 of the upper jig 10 is separated from the spherical body 14 as indicated by the phantom lines in FIG. Then, the test piece 100 is placed on the upper portion of the lower ring 21 of the second pressing member 22 .

In this state, the upper jig 10 is lowered together with the crosshead 51 . Then, the test piece 100 placed on the lower ring 21 is held between the upper ring 11 and the lower ring 21 . After that, the upper jig 10 is further lowered to bring the first pressing member 12 and the second pressing member 22 close to each other. The inner diameter of the lower ring 21 is larger than the inner diameter of the upper ring 11, and the diameter of the contact area between the lower ring 21 and the back surface of the test piece 100 is larger than the diameter of the contact area between the upper ring 11 and the surface of the test piece 100. , a test force for bending the test piece 100 is applied to the test piece 100 as the upper jig 10 descends. At this time, since the test force is applied to the first pressing member 12 from the elevating member 16 via the ball 14, the test force can be applied in a direction perpendicular to the front and back surfaces of the test piece 100. It becomes possible.

During such material testing, an image of the area of the specimen 100 within the lower ring 21 is captured by the high speed video camera 40 . As the test piece 100 continues to deform, the high-speed video camera 40 acquires an image at the moment when the test piece 100 breaks. At this time, the inner diameter of the lower ring 21 is larger than the inner diameter of the upper ring 11, and the shape of the through hole 29 is a circle having the same diameter as the inner diameter of the lower ring 21. Therefore, the upper ring in the test piece 100 All areas in the lower ring 21 , including the contact area between 11 and the test piece 100 , can be photographed by the high-speed video camera 40 . However, the diameter of the through hole 29 may be smaller than the inner diameter of the lower ring 21, and the shape of the through hole 29 may be other than circular.

The glass ring bending test is completed when the test piece 100 breaks.

In the above-described embodiment, the case where a glass plate is used as the test piece 100 and the test force is applied until it breaks, but the deformation of the test piece 100 before breaking may be measured. good. In such a case, a sticker or the like having a random pattern formed on the surface of the test piece 100 is attached, and the deformation of the test piece 100 is measured by stereo measurement in which the sticker is photographed from two directions by a camera. good too.

Further, in the above-described embodiment, glass, which is a type of ceramic, is used as the material of the test piece 100, but other ceramics may be tested. may be tested.

It will be appreciated by those skilled in the art that the exemplary embodiments described above are specific examples of the following aspects.

A material testing machine according to a first aspect of the present invention includes a first pressing member having a first ring that contacts a first surface of a plate-shaped test piece, and a first pressing member on the side opposite to the first surface of the test piece. a second pressing member having a second ring having an inner diameter different from that of the first ring that abuts on two surfaces; In a material testing machine that applies a test force to the test piece by moving the first pressing member and the second pressing member in a direction approaching each other, the inner side of the second ring in the second pressing member A through hole is formed in the region.

According to the material testing machine according to the first aspect of the present invention, even when the test force is applied to the test piece by the pair of rings, the By using the through holes, it is possible to perform imaging of the specimen in the region within the ring.

In the material testing machine according to the modification of the first aspect of the present invention, the reflective surface intersects the second surface of the test piece at a position opposite to the test piece with respect to the second pressing member. Further comprising a mirror arranged in a state of aligning.

According to this aspect, it is possible to photograph the test piece in the region within the ring from an arbitrary position using the mirror. Therefore, it is possible to increase the degree of freedom in arranging the cameras for photographing.

In the material testing machine according to another modification of the first aspect of the present invention, the inner diameter of the second ring is larger than the inner diameter of the first ring.

According to such an aspect, it is possible to photograph the contact area between the first ring and the test piece.

In the material testing machine according to still another modification of the first aspect of the present invention, the shape of the through-hole is circular having the same diameter as the inner diameter of the second ring.

According to such an aspect, it is possible to photograph all regions within the second ring of the test piece.

It should be noted that the above description is for the description of the embodiments of the present invention, and does not limit the present invention.

REFERENCE SIGNS LIST 10 upper jig 11 upper ring 12 first pressing member 13 supporting member 14 sphere 15 frame 16 lifting member 20 lower jig 21 lower ring 22 second pressing member 23 upper plate 29 through hole 30 mirror 31 supporting member 40 high-speed video camera 51 crosshead 100 test piece

Claims (4)

A first pressing member having a first ring that contacts a first surface of a plate-shaped test piece, and the first ring that contacts a second surface of the test piece opposite to the first surface have an inner diameter. and a second pressing member having a different second ring, wherein the first pressing member and the second pressing member are pressed against each other with the test piece disposed between the first ring and the second ring. In a material testing machine that applies a test force to the test piece by moving it in the direction of proximity,
The second pressing member has the second ring on one surface of a pedestal portion having a planar surface, and a through hole is formed in a region of the pedestal portion that is inside the second ring ,
a drive unit that moves the first pressing member in a direction toward the second pressing member;
an imaging unit that is located on the side of the second pressing member when viewed from the test piece and captures an image of a region within the second surface of the test piece through the through hole;
material testing machine. In the material testing machine according to claim 1,
The imaging unit is arranged in a state where the reflecting surface intersects the second surface of the test piece at a position opposite to the test piece with respect to the second pressing member through the through hole. material testing machine including mirrors. In the material testing machine according to claim 1 or claim 2,
The inner diameter of the second ring is greater than the inner diameter of the first ring. In the material testing machine according to any one of claims 1 to 3,
The material testing machine, wherein the shape of the through-hole is a circle having the same diameter as the inner diameter of the second ring.

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