JPH0725606B2 - Method for producing natural sand that produces pronunciation characteristics in water and sounder using underwater pronunciation sand - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an acoustic technique for vibrating particles, and relates to a method for producing natural sand that produces a sounding characteristic in water and a sounding body using the underwater sounding sand.

[Prior Art] In the sand that has naturally existed on the coast, the regular frequency that is different from the rubbing sound when you step on the sand
It is known that so-called "crying sand", which produces a pleasant sound called "kyu," and the identity of these crying sands is quartz sand.

[Problems to be Solved by the Invention] However, these naturally existing squealing sands produce this pleasant sound only when their feet are strongly rubbed against the sand. In addition to the moving sound, no pleasant sound peculiar to squealing sand occurs. Further, this kind of squealing sand does not produce a pleasant sound even when it is shaken by waves in the sea, and does not produce a remarkable sounding characteristic even if it is shaken by being present together with water in a container.

The present invention has been made for the purpose of exhibiting the sounding characteristics of the above-mentioned singing sand in a container and in the state of being present together with water, and proposes a method for producing natural sand that produces sounding characteristics in water. In addition, the object is to provide a sounding body made of underwater sounding sand.

[Means for Solving the Problem] That is, the method for producing natural sand (underwater squealing sand) that produces sounding characteristics in water according to the present invention is prepared by preliminarily preparing a soil having a viscosity of 0.1 to 2 mm obtained from a sand layer accompanied by clay. After being completely removed by the washing process, water and sand are further put in a cylindrical container at a volume ratio of about 1: 1 and the container is reciprocated or a constant radius swirling motion with the cylindrical part standing upright. Based on the above, a linear or circular motion is performed so that the movement speed of the mixture of water and sand particles is 10 m / s to 5 m / s, and the sand particles are rubbed against each other in water for a long-term purification and cleaning treatment. Completely removes dirt and other foreign matter attached to the surface,
The gist is to manufacture by rounding off the angular portions of the particles.

After the above-mentioned purification and washing treatment step, the water was thoroughly drained, and 1 to 3N dilute hydrochloric acid was added to the sand in a volume ratio of about 1: 1.
It is preferable to add an acid washing treatment step of performing light washing for 1 minute to several minutes, and then performing post washing by washing with water until the acidity disappears.

At this time, the time of the purification washing treatment step is as follows: (1) During the purification washing treatment, when the washing is continued for 1 hour, coloring other than white turbidity is not observed.

(2) 60 to 500 hours.

Can be determined by

Further, the underwater singing sand produced by the above-mentioned production method, the repose angle of the average sand grains is preferably 42 to 50 degrees, the sounding body by the underwater sounding sand, put the underwater singing sand in a container together with water, The gist is to fill the volume mixing ratio of sand and sand to an appropriate amount close to 1: 1. The container is preferably made of a hard material having resonance such as acrylic, vinyl and polycarbonate. Especially when dealing with large volumes,
It is desirable to apply a microvibration constantly to the container from the outside with a seismic generator to reduce the number of contact points between the sands.

[Operation] If the soil adhering to the quartz sand is completely removed by the preliminary water washing treatment step and then the purification washing treatment is further performed for a long time, the frictional characteristics of the particle surface can be changed, and the static friction between particles can be caused. Significantly increase the coefficient. That is, the angle of repose generally used for the evaluation of the friction coefficient of the particulate matter by this washing is from 42 to 50, which is 35 to 38 degrees, which ordinary sand has.
Rise to degrees. At the same time, the corners of the sand particles are polished and become rounded by co-sliding during washing, resulting in an increase in the packing density of the sand particles and an increase in the number of contact points between the particles. After the above-mentioned purification cleaning, an acid cleaning treatment with dilute hydrochloric acid can remarkably improve the pronunciation characteristics.

When the sand particle group is housed in a container and placed in motion, a shear plane is formed inside the particle layer, as is generally known. Sliding occurs in the limit state where sufficient force is applied on the shear surface. When slippage occurs, the coefficient of friction of the shear surface of the particle layer changes from the static coefficient described above to the state in which the dynamic friction coefficient acts, and it rapidly moves along the shear surface, but at this time, the sand layer expands, As soon as the sand layer is pushed up and the applied force is released, it stops moving and returns to its previous state of rest. By repeating this process momentarily, vibration occurs in the sand layer, and the repetition rate causes sound characteristics with a specific frequency sound (50 to 800 Hz) and a squealing sand phenomenon.

This was filled so that the volume mixing ratio of water and sand particles was 1: 2, and the container was rocked to shake the sand inside, causing the container to resonate and to make a "squeak" sound.

[Embodiment] An embodiment of a method for producing natural sand that produces a sounding characteristic in water according to the present invention will be described below.

Natural sand as a raw material Natural sand containing quartz crystals as a main component and having a bright characteristic is preferable (although sand “singing sand” having a sounding characteristic exists on the shore, etc., these have almost no sounding characteristic in water, Also, from the viewpoint of aesthetics, it is difficult to use because foreign matter is significantly mixed in).

Among the ancient quartz sands buried in the clay layer, it is possible to find one suitable for this application. In Japan, sand layers with clay widely distributed in the Tohoku region can be used.

Cleaning treatment of natural sand [Preliminary cleaning treatment] Sand grains obtained from a sand layer with clay (grain size of quartz sand is 0.1 to 2 m
After the soil adhering to m) is completely removed by the preliminary water washing process, the next purification and washing process is performed for a long time.

[Purification and cleaning treatment] Put water and sand in a volume ratio of approximately 1: 1 into a cylindrical container, and with the cylindrical part upright, reciprocate with the container or a straight line or circle based on a constant radius turning motion. By moving and rubbing sand grains against each other in water, soil and other foreign matter adhering to the particle surface are completely removed, and the angled parts of the particles are rounded. Clean the sand without damaging the surface of the sand without touching the object. The movement speed of sand in this washing is preferably 10 m / s to 5 m / s, and sound can be produced for 60 hours or more, but if a washing time of about 500 hours is further applied, high frequency sound can be generated. . The determination of the degree of purification and washing by this water washing can be carried out based on the fact that when washing is further continued for 1 hour, it does not cause colored turbidity but only becomes cloudy. In this purification and cleaning treatment step, it is effective to add a suitable amount of hydrochloric acid or a synthetic detergent to the cleaning water to enhance the cleaning effect.

Through this purification and cleaning treatment step, fine particles such as soil adhering to the surface of the sand grains are completely removed, so that the friction points of the surface of the sand particles are increased to be more than 10 which is about 6 for ordinary sand grains. To cause a significant increase in the coefficient of static friction between particles. The angle of repose commonly used to evaluate the coefficient of friction of particulate matter is 35 to 38 degrees for ordinary sand, but this washing process
Rises to ~ 50 degrees. At the same time, the corners of the sand particles are polished and become rounded by co-sliding during washing, and the number of points of contact between the particles increases, resulting in an increase in the packing density of the sand particles.

[Acid cleaning treatment] It is desirable to perform an acid cleaning treatment on the sand grains that have undergone the previous purification cleaning treatment step.

After completion of the purification and washing treatment, after sufficiently draining water, dilute hydrochloric acid (1 to 3N) is added in an amount substantially equal to the bulk volume of sand, and shaken gently for about 1 minute, and then washed by washing with water until the acidity disappears. As a result, the pronunciation characteristics can be significantly improved. At this time, it is confirmed by PH value that residual acid has disappeared. Then, the vibration is continued for several minutes to obtain a predetermined sounding characteristic.

Sound Generation Characteristics of Natural Sand in Water When a group of sand particles configured as described above is placed in a container and placed in motion, a shearing surface is formed inside the particle layer as is generally known. Since the particle size is large, the particle group slides in the limit state where sufficient force is applied on the shear surface.
When slippage occurs, the coefficient of friction of the shear surface of the particle layer changes from the static coefficient described above to the state in which the dynamic friction coefficient acts, and it rapidly moves along the shear layer, but at this time, the sand layer expands, As soon as the sand layer is pushed up and the applied force is released, it stops moving and returns to its previous state of rest. By repeating this process a plurality of times instantaneously, vibration occurs in the sand layer, and due to this repetition rate, it has a specific frequency sound and exhibits sounding characteristics.

Further, the larger the difference between the static friction coefficient and the dynamic friction coefficient, the larger the magnitude of vibration.

The inertial force due to the vibration of the sand particles causes the vibration of the container wall in contact with the sand particles to generate sound. This vibration is 50 to 800 hertz. The larger the amount of sand, the louder the sound.

Regarding Container and Tone Color The above-mentioned container is made of a transparent material by selecting a hard and resonant material such as acrylic, vinyl, or polycarbonate.

The squealing sand washed as described above has a volume mixing ratio of water and sand of
Fill to 1: 1 and rock the container to shake the sand inside.

The size of the generated sound can be changed by changing the size of the container to 100 ml, 500 ml, 1000 ml or the like.

In the above-mentioned container, in the case of using a large amount of sand grains such as 1000 ml, a fine vertical vibration is constantly applied to the container from the outside by an appropriate vibration device such as a vibrator, and the sand particles are mutually By slightly reducing the number of contact points (which is 10 or more), the sand layer can be kept in a movable state.

Further, it is possible to change the resonance range by changing the form of the container to emphasize a specific sound range, and it is also possible to change the scale to some extent by changing the grain size of the sand grains to be contained.

In a relatively small container, the sound generated by rocking the container resembles the sound of a frog, and when this is combined with an animal, for example, a stuffed animal that imitates the shape of a frog, a toy is produced. It has sufficient characteristics as a toy.

Furthermore, by making the container for storing the squeal sand transparent,
The movement of the sand can be visually observed from the portion, and the interest as a toy can be increased.

[Effects of the Invention] As described above, the method for producing natural sand that produces the pronunciation characteristics in water according to the present invention and the sounding body using the underwater sounding sand can be obtained by increasing the diameter of the container containing the sand grains, for example, about 1000 It is also possible that the inertial force of the sand becomes large and a roaring sound reminiscent of the voice of a dinosaur is generated. It has a feature that it is possible to create an exhibit (monument) having a special acoustic effect by utilizing an automatic mechanism for reciprocating the container, and the practical effect after the present invention is carried out is extremely large.

Claims (11)

[Claims] 1. A cylinder obtained by completely removing soil adhered to a sand grain having a grain size of 0.1 to 2 mm obtained from a sand layer accompanied with clay by a pre-washing process, and further making water and sand in a volume ratio of about 1: 1. In a cylindrical container, with the cylindrical part standing upright, reciprocal or constant radius swirling motion with the container as a basic, linear or circular motion so that the motion speed of the mixture of water and sand grains becomes 10 m / s to 5 m / s It is characterized by rubbing sand grains against each other in water for a certain period of time for purification and cleaning to completely remove soil and other foreign matter adhering to the particle surface and round off the angular part of the particle. A method for producing natural sand that produces sounding characteristics in water. 2. Draining the water sufficiently after the purification washing process, 1
To 3N dilute hydrochloric acid at a bulk volume ratio of sand of about 1: 1 and lightly shake for 1 to several minutes, after which an acid washing process is performed by washing with water until the acidity disappears. The method for producing natural sand producing a sounding characteristic in water according to claim 1, wherein the natural sand is added. 3. The natural sand producing a sounding characteristic in water according to claim 1 or 2, wherein the time of the purification washing treatment step is such that no coloring other than white turbidity is observed when washing is further continued for 1 hour. Manufacturing method. 4. The time for the purification and cleaning process is 60 hours to
The method for producing natural sand which produces a pronunciation characteristic in water according to claim 1 or 2, which is 500 hours. 5. A cylinder having a volume ratio of water and sand of approximately 1: 1 after completely removing the soil adhering to the sand grains having a grain size of 0.1 to 2 mm obtained from a clay-laden sand layer by a preliminary washing process. In a cylindrical container, with the cylindrical part standing upright, reciprocal or constant radius swirling motion with the container as a basic, linear or circular motion so that the motion speed of the mixture of water and sand grains becomes 10 m / s to 5 m / s It is characterized by rubbing sand grains against each other in water for a certain period of time for purification and cleaning to completely remove soil and other foreign matter adhering to the particle surface and round off the angular part of the particle. Underwater pronunciation sand. 6. Draining the water sufficiently after the purification and washing process, 1
To 3N dilute hydrochloric acid at a bulk volume ratio of sand of about 1: 1 and lightly shake for 1 to several minutes, after which an acid washing process is performed by washing with water until the acidity disappears. The underwater sounding sand according to claim 5, which has been subjected to an acidic washing treatment after that. 7. The underwater sounding sand according to claim 5, wherein the average repose angle of the sand grains is 42 to 50 degrees. 8. The sound-producing sand according to claim 5, 6 or 7 is put together with water in a container, and the volume mixing ratio of water and sand is filled to an appropriate amount close to 1: 1 to form the container. A sounding body based on underwater sounding sand, which is rocked to give a rocking motion to the sand inside to produce sound. 9. A sounding body made of underwater sounding sand according to claim 8, wherein a fine vibration is constantly applied to the container from the outside by an appropriate vibration generator to reduce the number of contact points between the sands. 10. A sounding body made of underwater sounding sand according to claim 8, wherein the container is made of a hard material having resonance such as acrylic, vinyl, and polycarbonate. 11. A sounding body made of underwater sounding sand according to claim 8 or 9, wherein said container is transparent.