JPH0664013B2 - Material vibrating device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the invention (Industrial field of application) The present invention relates to a vibrating device for a material used for obtaining a mechanical constant of the material by, for example, a resonance method.

(Prior Art) Mechanical constants such as elastic modulus and rigidity of materials such as ceramics, metals, plastics, and wood can be obtained by a resonance method in which a material is excited to measure a resonance frequency peculiar to the material. . This method is particularly effective for materials having a high Young's modulus such as ceramics.

Conventionally, a material is hit with a hammer or the like to vibrate, or one end of the thread is adhered to the cone part of the speaker and the other end is adhered and the sound is emitted from the speaker by the thread. The material was vibrating.

However, in the case of vibration by the above-mentioned impact, it is difficult to measure the resonance frequency unless the material has a certain size, and the skill of the impact is required. In addition, in the case of the vibration due to the propagation of the sound wave, there are drawbacks that the vibration characteristic of the vibration exciter itself propagates to the yarn, the original resonance frequency of the material is difficult to measure, and the vibration efficiency is poor due to the attenuation during propagation. It was

Therefore, a conductive material is applied to the surface of the material to form an electrode, and an alternating voltage is applied to vibrate the material.

(Problems to be Solved by the Invention) In the case of vibration with the alternating voltage, there is a drawback that it takes too much time to apply the conductive material. Further, the resonance frequency of the material may change depending on the amount of the conductive material applied.

The present invention has been made under the circumstances as described above,
An object of the present invention is to provide a material and a vibrating device that can easily obtain an accurate resonance frequency of the material.

(Structure of the Invention) (Means for Solving the Problems) The present invention relates to a vibrating device for a material used for obtaining a mechanical constant of the material by, for example, a resonance method. And a sound-insulating plate in which a hole having a predetermined diameter is bored, the sound wave generator is mounted on one surface, and a vibration non-propagating material is mounted on the other surface. Then, the material is placed on the vibration non-propagation material, and the sound wave emitted from the sound wave generator to the material and projected through the hole is projected to vibrate the material.

(Operation) Since the vibrating device of the material of the present invention is configured to project and vibrate a sound wave in a non-contact manner on a predetermined portion of the material, it is possible to accurately measure the resonance frequency of the material, The mechanical constant of the material can be easily obtained by appropriately combining the sound wave projection position and the resonance frequency measurement position.

(Embodiment) FIG. 1 is a perspective view showing an example of a vibrating device for a material of the present invention, and FIG. 2 is a side view when the material is set in the vibrating device. Hole 2A
Is provided near the cone portion 1A of the speaker 1,
And the sound insulating plate 2 mounted so as to cover the cone portion 1A, the hole 2A of the plate 2 is located substantially in the center of the cone portion 1A of the speaker 1, and the plate on the side where the speaker 1 is not mounted A support 3 is mounted on the surface of No. 2 and does not transmit vibration to the placed material. The loudspeaker 1 used in this example is a general one, for example, a rating of 60 W and a frequency range of 50 Hz to 40 kHz. The plate 2 is made of, for example, aluminum, and the gap d between the plate 2 and the cone portion 1A of the speaker 1 is a distance (for example, 2 to 3 m) that does not cause a phase shift of sound by the plate 2.
m) is set. The support 3 is, for example, a cylindrical urethane having a height of 5 mm, sponge, etc., and a plurality (four in the example) are mounted around the hole 2A.

An example of the operation in such a configuration will be described. For example, a rectangular parallelepiped (100 mm in length × 20 mm in width ×
Place the material 4 with a thickness of 4 mm on the support 2 so that the central part of the material 4 is above the hole 2A of the plate 2, and pick up the material 4 on the central part of the upper surface of the material 4 (the amplitude of the material, the speed of vibration or acceleration). Piezoelectric acceleration sensor that generates proportional voltage) 5
Put on. Then, when a sound wave is generated from the cone portion 1A of the speaker 1, the sound wave passes through the hole 2A of the plate 2 and is projected on the central portion of the material 4. Therefore, the material 4 vibrates with its central portion having the maximum amplitude, and thus the amplitude, speed, and acceleration of the vibration can be detected by the pickup 5.

In this way, since the sound wave is projected onto the central portion of the material 4 to obtain the longitudinal vibration (see FIG. 3), the elastic modulus of the material 4 can be obtained. Further, as shown in FIG. 4, if the sound wave is projected to the corner portion of the material to obtain the vibration, the torsional rigidity of the material 4 can also be obtained. At this time, the mounting position of the pickup 5 is moved to the corner of the upper surface of the material 4. In order to longitudinally and torsionally vibrate the material 4, the diameter of the holes 2A of the plate 2 is set to 1/2 or less of the width of the material 4, and the number of the holes 2A is not limited to one. Good as an individual.

Although the contact type pickup is used in the above-described embodiment, a non-contact type pickup may be used.

As described above, according to the material vibrating device of the present invention, the material can be vibrated easily and accurately.
The development can be speeded up, and the structure is simple, so it can be provided as a low-priced device.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of a material vibrating device of the present invention, FIG. 2 is a side view when the material is set in it, and FIGS. 3 and 4 are vibrating parts of the material by the device, respectively. FIG. 1 ... Speaker, 1A ... Cone part, 2 ... Plate, 2A
...... Hole, 3 ... Support, 4 ... Material, 5 ... Pickup.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Koichiro Otomo Inventor, Koichiro Otomo 2-272 Yakumohigashi-cho, Moriguchi-shi, Osaka (56) References JP-A-49-101015 (JP, A) Shoukai Sho-16-16197 (JP, U)

Claims (2)

[Claims] 1. A sound wave generator for generating a sound wave for exciting a material, and a hole having a diameter of ½ or less of the width of the material is penetrated from one surface to the other surface, A sound-insulating plate having the sound wave generator mounted on a surface thereof and a vibration non-propagating material for mounting the material on the other surface, the material being mounted on the vibration non-propagating material. The material vibrating device is characterized in that the material is vibrated by projecting a sound wave emitted from the sound wave generator to the material and passing through the hole. 2. The material vibrating device according to claim 1, further comprising a sensor for detecting vibration of the material.