JPH0142025Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to a loading jig used for four-point bending strength testing of ceramics.

(Prior Art) Bending strength is generally determined as basic data on the properties of ceramics used as heat-resistant materials, carbide tools, cutting tools, and for physical and chemical applications under conditions such as high temperature, high pressure, and corrosion. The test method for this bending strength is 3-point bending and 4-point bending according to JIS R1601.
A point bending test method is known.

Among these, a jig having a structure shown in FIG. 2 is conventionally known as a jig used when performing a four-point bending test. In Figure 2, the specimen holder 2
Support points 22a and 22b are provided at 30 mm intervals on test piece 1, and test piece 23 has a width of 4 mm, a thickness of 3 mm, and a total length of 40 mm.
are placed on the fulcrums 22a and 22b. Test piece 23
On the top, there are load points 24a provided at intervals of 10 mm,
The loading jig 25 having the supporting points 22a and 22b is
The test was carried out by placing the test tube so that the distance between it and the load points 24a and 24b was 10 mm, and applying a load from above.

(Problems to be solved by the invention) In the jig having the above-described structure, after the test piece 23 is placed on the pedestal 21, the loading jig 25 must be accurately positioned and set on the test piece 23. As a result, the positioning work is difficult and time consuming. In addition, all conventional jigs were made of metal, which made it impossible to test at high temperatures, or the jigs were expensive due to their complex structures, and were consumables that were discarded after dozens of tests. It was unsuitable as a tool.

The purpose of the present invention is to eliminate the above-mentioned problems and provide a four-point bending loading jig made of ceramics that can easily and quickly position the loading jig with respect to the test piece, can also be tested at high temperatures, and is inexpensive. This is what I am trying to do.

(Means for solving the problem) The present invention consists of a test piece holder, a push pin on the test piece holder, and two pieces provided at a predetermined interval in contact with the test piece placed on the push pin. An upper loading jig that has load points at both ends of its lower surface, a holding jig that applies a predetermined force through the upper loading jig, and an open end that engages the periphery of the specimen holder so as to accommodate the specimen holder. It is characterized by comprising a lid body which is fitted together with a lid body and has a through hole for engaging an upper loading jig.

(Function) The present invention is based on two
The upper loading jig, which has several load points at both ends, and the lid are engaged through a through hole in the lid, so that the upper load jig, which has several loading points at both ends, is engaged with the lid through a through hole provided in the lid. By simply placing the upper loading jig and engaging the open end of the lid with the test specimen holder, the predetermined four-point positional relationship specified by JIS can be achieved. Furthermore, since the entire jig is made of ceramics such as SiC, it can also be used for testing at high temperatures.

(Example) FIG. 1 is a diagram showing an example of a four-point bending load jig for ceramics of the present invention. In FIG. 1, two notches 2a, 2b are provided on a SiC test piece holder 1 at an interval of 30 mm, and push pins 3a, 3b are attached to the notches 2a, 2b. A width of 4 mm and a thickness of 3 mm are placed on these push pins 3a and 3b.
If a test piece 4 with a length of 40 mm and a total length of 40 mm is placed, the span of 30 mm specified by JIS can be achieved.

The upper loading jig 5 made of SiC has two loading points 6a and 6b provided at an interval of 10 mm on its lower surface, and its top has a roof-like shape with a triangular cross section. At this time, the larger the angle of the top triangle, the more stable it will be. By setting this upper loading jig 5 at a predetermined position on the test specimen 4, it is possible to achieve the positional relationship specified by JIS, where the distance between the fulcrum and the loading point is 10 mm. In order to position this upper loading jig 5 on the test piece 4, a lid 7 is used in the present invention. This lid body 7 is made of SiC and has open ends 8a and 8b that engage with the test specimen holder 1, and has a through hole 9 that engages with the upper loading jig 5 in the center of its upper surface. Further, on the lower surface of the lid body 7, a groove 10 including a through hole 9 and having the same width as the upper load jig 5 is extended in the longitudinal direction in the figure, so that the upper load jig 5 is inserted in a direction perpendicular to the longitudinal direction when installed. It is positioned so that it does not move. By using the above-mentioned lid 7, the upper loading jig 5, that is, the loading points 6a, 6b can be accurately placed against the specimen 4 by a simple operation of engaging the open ends 8a, 8b with the specimen holder 1. can be positioned. In addition, when actually conducting the test, a SiC presser jig 11 that engages with the top of the upper load jig 5 is provided to apply the load, so that the load is evenly applied to the jig of the present invention. I have to.

The present invention is not limited to the embodiments described above, but can be modified and modified in many ways. For example, in the embodiments described above, SiC was used as the ceramic, but other ceramics may also be used. Further, although the top of the upper loading jig has been described as having a triangular cross section and a roof shape, other shapes may be used as long as the same purpose can be achieved. Also, the load point distance is 30
and 10mm, test piece width 4mm, thickness 3mm, total length 40mm
Although the case described above has been explained, even if the load point distance or the dimensions of the test piece change, the test can be performed by simply changing the jig dimensions.

(Effects of the invention) As is clear from the detailed explanation above, according to the four-point bending loading jig for ceramics of the invention, the load can be controlled by the simple operation of engaging the lid with the specimen holder. The tool can be positioned easily and quickly with respect to the test piece. Also,
Since the entire jig is made of ceramics, it can be tested at high temperatures, is inexpensive, and has good workability. Therefore, by using the loading jig of the present invention, bending strength tests that conventionally took time can be conducted in a short time.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an embodiment of the ceramic four-point bending loading jig of the present invention, and FIG. 2 is a diagram showing a conventional four-point bending loading jig. 1... Test piece holder, 2a, 2b... Notch, 3a, 3b... Push pin, 4... Test piece, 5
...Top loading jig, 6a, 6b...Loading point, 7...
...Lid body, 8a, 8b...Open end, 9...Through hole,
10...groove, 11...presser jig.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. A test piece holder, a push pin on the test piece holder, and two load points provided at a predetermined interval in contact with the test piece placed on the push pin on the lower surface thereof. an upper loading jig at both ends; and a lid whose open end is engaged with the periphery of the specimen holder so as to house the specimen holder, and which has a through hole for engaging the upper loading jig. A four-point bending load jig for ceramics, characterized by comprising: 2. The ceramic four-point bending loading jig according to claim 1, wherein the test piece holder, push pin, upper loading jig, and lid are made of ceramics. 3. The four-point bending loading jig for ceramics according to claim 1, wherein the through hole of the lid is created by grinding in a direction perpendicular to both the upper and lower surfaces. 4. The four-point bending loading jig for ceramics according to claim 1, wherein the upper surface of the upper loading jig has a roof-like slope.