JPH07119680B2 - Jig for ceramic fatigue test - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a jig used for applying a vibration to a ceramic and testing the durability of the ceramic to fatigue failure.

<Prior Art> As shown in FIG. 6, a jig a for durability test of ceramics is used.
Is a vibration horn b having a large-diameter base end portion c having a back surface as an installation surface and a reduced-diameter projection portion e protruding forward from a fixed collar d of the base end portion c. A vibrator f is fixed, and a rod-shaped ceramic sample p is formed at the tip of the reduced diameter projection.
It is provided by fixing.

Then, this one sets the ultrasonic transducer f and the entire length of the vibrating horn b to 1 / 2λ for the wavelength λ of the applied voltage, respectively, and positions the fixed collar d in the middle of the vibrating horn b. ,
Further, the length of the ceramic sample fixed to the tip of the reduced diameter protrusion e is also set to 1 / 2λ, and the entire length of the jig a is set to 1 / 2λ × (n + 1).
(Where, λ; wavelength, n; integer) are set so that the center of the ceramic sample p becomes the node position, and the longitudinal vibration along the axial direction causes The maximum stress was applied to the node position.

<Problems to be Solved by the Invention> By the way, in such a configuration in which the longitudinal vibration is used to cause fatigue of the sample p, the sample is thin and the entire length is 1 / 2λ. Therefore, it is not possible to shorten the length of the sample p. Therefore, the tip of the sample p is easily vibrated in the lateral direction, and complicated fatigue is given to the sample p, so that stable test results cannot be obtained. is there.

An object of the present invention is to provide a fatigue test jig that can give stable fatigue to the sample p without using longitudinal vibration.

<Means for Solving Problems> In the present invention, the front end of a large-diameter base end portion having a fixed collar is bonded to the front end of the large-diameter base end portion with an adhesive at a position deviating from the node position of bending vibration induced on the ceramic sample. A vibrating horn that is fixed and that projects a supporting edge that laterally supports the ceramic sample, and that applies bending vibration to the sample through the supporting edge,
A jig for a fatigue test of ceramics, characterized by comprising an ultrasonic vibrator connected to the rear surface of the vibrating horn.

<Operation> The ceramic sample is laid horizontally on the tip of the supporting edge of the vibrating horn having the ultrasonic transducer coupled to the rear surface, and is supported by the adhesive. Then, when the ultrasonic oscillator and the vibrating horn are longitudinally vibrated, the sample supported by the tips of the supporting edges is excited in the bending mode, and the maximum stress is applied at the center position between the tips. It causes fatigue and breaks.

The tip of the supporting edge of the vibrating horn is of such a length that it comes into contact with either the inside or the outside depending on the node position of bending vibration induced on the sample.If the tip is at the node position, the sample bends. It does not resonate in the mode.

<Example> FIG. 1 shows an example of the jig x of the present invention. Where 1
Is a vibrating horn that is attached to the supporting edge y while holding the fixed collar 2, and an ultrasonic transducer 5 is fixed to the mounting surface 4 on the rear surface of the large-diameter base end portion 3 of the vibrating horn 1. This ultrasonic transducer 5 is a piezoelectric element composed of a pair of annular piezoelectric elements 7, 7 and an annular terminal plate 8 arranged between the elements and on the upper and lower surfaces of the elements. , 9b are applied, they are planted on the installation surface 4 through the bolts 10, and they are integrally fastened and fixed.

As shown in FIG. 2, the vibrating horn 1 has two arcuate linear support edges 11, 11 arranged in line symmetry, which are one example of support edges, projecting in front of the fixed collar 2. It has the function of expanding the amplitude at the tips of the linear support edges 11, 11.

The length relationship between the above-mentioned constituent elements is determined by the total length of the ultrasonic transducer 5.
1 / 2λ, the vibration horn 1 is also set to 1 / 2λ. Then, when the bending mode is applied to the ceramic sample p, as will be described later, the tips of the linear support edges 11 and 11 are fixed with an adhesive to abut on the vibration node positions n and n. And held. The ceramic sample p may be provided in various shapes such as a disk shape and a rectangular plate shape.

When an alternating voltage of wavelength λ is applied to the terminal plates 8, 8 of the piezoelectric element 4 after mounting the ceramic sample p, the piezoelectric element 4 and the vibrating horn 1 integrally longitudinally vibrate. Then, between the linear support edges 11 and 11, the longitudinal vibration is converted into a bending mode, the ceramic sample p is curved, and the maximum stress is applied at the center position o thereof. Therefore, the ceramic sample p is fatigued at the position o and is broken when the durability is exceeded, and the material characteristics of the ceramic sample p are detected.

The distance d between the linear support edges 11 and 11 is set so as to avoid the vibration node positions n and n on the sample, and by changing this, the displacement of the center position o of the sample p can be adjusted. it can.

3 to 5 show a modified example of the supporting edge, FIG. 3 is composed of two linear supporting edges 20 and 20 arranged in line symmetry, and FIG. 4 is an annular supporting edge. In FIG. 5, the supporting edge is composed of two supporting point edges 22,22. In addition, in the configuration of supporting at the support point edge,
In order to support the ceramic sample p more stably, the ceramic sample p may be composed of three or more supporting points arranged on a concentric circle at equal angular intervals.

Further, in the annular supporting edge 21, the separation distance d becomes the diameter thereof, and in the supporting point edge, the distance passing through the center thereof. In any case, the displacement of the center position o of the sample p can be adjusted by changing the separation distance d.

<Effect> As described above, according to the present invention, the supporting edge is projected on the vibration horn 1, the ceramic sample p is supported by the tip of the supporting edge, and the vibration due to the bending mode is applied to the sample p by the supporting edge.
Since the maximum stress is applied to the center position o to cause breakage, compared with the conventional jig,
Unnecessary vibration does not occur, stable fatigue can be imparted, the test conditions can be kept constant, and the output loss caused by the unnecessary vibration is small and the power is relatively increased. Further, the distance d between the support edges can be arbitrarily selected, the swing width can be easily adjusted, and various test conditions can be set. Further, as a result, the length of the sample p can be reduced, and it is economical because it requires only a small piece.

[Brief description of drawings]

FIG. 1 is a side view of a jig x according to an embodiment of the present invention, and FIG. 2 is a cross-sectional plan view cut along the linear support edges 11, 11. Further, FIGS. 3 to 5 are cross-sectional plan views of modified examples of the support edge, and FIG. 6 is a side view of the jig a having the conventional structure. x; jig, 1; vibrating horn, 2; fixed brim, 3; base end, 5; ultrasonic transducer, 11, 11; linear support edge, 20, 20; linear support edge, 21; circular ring Support edge, 22,22; Support edge, p; Ceramic sample

Claims (4)

[Claims] 1. A ceramic sample is laid laterally on the front part of a large-diameter base end part having a fixed jaw, with its tip fixed with an adhesive at a position deviating from the node position of bending vibration induced on the ceramic sample. A ceramic comprising a vibrating horn projecting a supporting edge for supporting in a circular shape and imparting bending vibration to the sample through the supporting edge, and an ultrasonic transducer coupled to the rear surface of the vibrating horn. Jig for fatigue test. 2. The support edge is constituted by two pairs of arcuate linear and linear linear support edges arranged symmetrically in front of the vibrating horn. A jig for fatigue test of ceramic according to the item. 3. The jig for fatigue testing of ceramics according to claim 1, wherein the supporting edge is an annular supporting edge. 4. The support edge according to claim 1, wherein the support edge is composed of two to a plurality of support point edges arranged concentrically on the front surface of the vibrating horn at equal angular intervals. Jig for ceramic fatigue test.