JPS6234691B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a liquid cooling strengthening apparatus that strengthens a glass article by liquid cooling while applying ultrasonic vibrations to the glass article.

To strengthen a glass article, cooling gas (usually air) is blown onto the glass surface that has been heated above the strain point and below the softening point to rapidly cool it, and when the glass article passes through the strain point, the glass surface and center part A method has been adopted in which the temperature difference is increased and strong compressive stress is generated in the glass surface layer after cooling to room temperature.

However, the above method is effective when the thickness of the glass article is about 4 m/m or more, and has already been industrialized, but the method is effective when the thickness of the glass article is about 3 m/m or more.
m or less, it was not possible to obtain a cooling capacity sufficient to provide a sufficient temperature difference between the glass surface and the center, and therefore it was not possible to apply strong compressive stress to the glass surface layer.

One way to strengthen such glass articles with a thickness of 3 m/m or less is to immerse the glass article, which has been heated above the strain point and below the softening point, in a cooling liquid such as oil or water. A so-called liquid-cooling strengthening method has been proposed, in which the glass surface layer is cooled to a large temperature difference, and strong compressive stress is applied to the glass surface layer after cooling to room temperature.

However, in this liquid cooling strengthening method, in order to prevent the glass article from breaking due to the stress generated during rapid cooling, there is a method that reduces the cooling ability by forming a gas layer at the interface between the glass surface and the cooling liquid, or a cooling method that reduces the cooling ability. Methods have been proposed, such as using a coolant that does not have a very high capacity. However, it is difficult to obtain glass articles with satisfactory strength using these methods.

As a method for improving the strength of glass articles by the above-mentioned liquid cooling strengthening method, the present applicant first forms an ultrasonic sound field in a cooling liquid and inserts a heated glass article into this field. It was discovered that a significantly high reinforcement strain could be introduced into the
The application was filed as No. 51329.

As a result of studying an apparatus for carrying out such an ultrasonic liquid cooling strengthening method, the present inventor found that as the size of the glass article to be ultrasonic liquid cooling strengthened increases, the cooling liquid tank becomes larger. We found that it is necessary to take measures to prevent split vibrations, to equalize the sound pressure of ultrasonic vibrations, and to make repairs easier. for example,
If a single diaphragm is used to cover the entire glass plate, there will be a large difference in amplitude between the center and the vicinity of the periphery, and the glass plate will undergo split vibrations, making the sound pressure of the ultrasonic waves likely to be uneven.

The present invention unitizes an ultrasonic vibrating element that oscillates ultrasonic waves, limits the size of the unitized ultrasonic diaphragm to a predetermined size, and cools the diaphragm at a predetermined interval. The unitized ultrasonic diaphragms are arranged on one surface of the liquid tank, and the unitized ultrasonic diaphragms are arranged on the other surface opposite to this surface, and the areas between the ultrasonic diaphragms that are not irradiated with vibration are interpolated. This arrangement improves the above-mentioned drawbacks.

That is, the gist of the present invention is to provide a liquid cooling strengthening apparatus for glass articles in which a glass article heated to a temperature above the strain point and below the softening point is immersed in a cooling liquid bath for liquid cooling strengthening. The present invention relates to a liquid cooling strengthening device for glass articles, characterized in that ultrasonic diaphragms each having a plurality of ultrasonic diaphragms formed into units on opposing sides are arranged facing each other so as to complement each other.

Hereinafter, the present invention will be explained in more detail with reference to the drawings.

The liquid cooling reinforcement device of the present invention has a plurality of ultrasonic diaphragms 4 each having a plurality of ultrasonic vibration elements 3 formed into a unit on the outside of the opposing wall 2 of a cooling liquid tank 1, as shown in FIGS. 1 to 7, for example. They are provided at predetermined intervals. The diaphragm 4 of the ultrasonic vibration element is arranged to cover the glass plate that is immersed and strengthened by liquid cooling.
As shown in FIGS. 1, 3, and 4, the diaphragms 4 are provided facing each other so that the area A between adjacent diaphragms 4 is interpolated by the opposing diaphragms 4. In this way, the sound pressure can be made almost constant in the portion where the high pressure between the diaphragms is weak by the diaphragms of the opposing ultrasonic transducer elements.

The diaphragm of an ultrasonic vibration element has a desired output depending on the dimensions and thickness of the glass plate to be strengthened or the dimensions and shape of the cooling liquid tank, for example, an output of several hundred watts to several tens of kW per unitized diaphragm. The number of ultrasonic transducer elements to be made into a unit is selected so as to obtain the following. For example, several to over 100 ultrasonic vibrating elements are made into a unit to form one ultrasonic diaphragm. Further, the row spacing of each vibrating element is selected so that the sound pressure is uniform. In the example illustrated in FIG. 1, the row interval B of the ultrasonic transducer elements is approximately 10 to 30 mm. Similarly, the distance between the diaphragms of adjacent ultrasonic transducers can be determined by the dimensions, output, sound pressure distribution, width of the cooling liquid tank, mounting condition of the diaphragms, thickness of the glass plate, etc. of the diaphragms of the ultrasonic transducers to be interpolated. Select the optimal value by Further, a predetermined number of such ultrasonic diaphragms, for example, several to several tens, are arranged depending on the size and shape of the cooling liquid tank and the size and shape of the glass plate to be strengthened.

Note that if the diaphragms are simply placed parallel to each other, they will receive vibrations from the ultrasonic transducer elements facing each other, generating electromotive force in the transducer elements, which in turn will flow through the circuit and stop oscillation. If this occurs, the oscillation frequency may be shifted, or the diaphragms of opposing ultrasonic transducer elements may be placed at a distance so that they do not receive vibrations from the opposing diaphragms. By doing so, the total sound pressure received by the opposing diaphragms is significantly reduced, and the above-mentioned trouble can be prevented. For example, the upper side of the glass plate 1 tends to be harder to strengthen than the lower side, so the upper interval is narrowed as shown in Figure 7.
The glass plate is brought close to the ultrasonic diaphragm, and the distance between the diaphragms is set so that there is a difference of about one wavelength between the top and bottom, so that the upper side of the glass plate receives stronger sound pressure than the lower side. Moreover, by doing so, the stability of the cooling liquid tank can also be improved.

The ultrasonic diaphragm is arranged as described above and is fixed by pasting, attaching, fitting, or bolting to the outside of the opposing side walls of the cooling tank so as to make contact with the wall surface. Alternatively, a hole or recess may be provided in the side wall of the cooling liquid tank, the ultrasonic diaphragm may be embedded in it, and the surrounding area may be sealed.
Alternatively, it may be attached inside the side wall of the cooling tank.

Further, it is preferable that the ultrasonic diaphragm is arranged on the wall surface of the cooling liquid tank in such a direction that the direction of irradiation of the ultrasonic waves is approximately perpendicular to the glass surface.

In the case of a cooling tank with a quadrilateral cross section, the ultrasonic diaphragm can be provided not only on one set of opposing surfaces but also on two sets of opposing surfaces. If not, the ultrasonic diaphragms are arranged so as to interpolate and face each other depending on the shape.

Further, as shown in FIGS. 5 and 6, a plurality of ultrasonic diaphragms can be arranged substantially parallel and diagonally at predetermined intervals, and furthermore, the diaphragms facing each other can be arranged so as to interpolate each other. . When the unit plates are arranged diagonally in this manner, there is an advantage that the glass plate immersed in the vertical direction is more uniformly irradiated with ultrasonic waves.

Further, the optimum value of the distance from the ultrasonic diaphragm to the immersed glass plate, ie, the width of the cooling tank, is determined based on the sound pressure level of the ultrasonic vibration element and its spread. In addition, what is shown in FIG. 1 is an example in which the distance between the diaphragm and the glass plate is 50 to 60 mm.

The oscillation method of ultrasonic waves may be either magnetostrictive or electrostrictive, and the oscillation frequency is such that when a glass article is immersed in a cooling liquid, the cavitation bubbles generated by the ultrasonic waves interact with the hot glass plate and the cooling liquid. 10 KHz to 100 KHz, preferably in order to effectively destroy the boundary film layer formed at the interface and improve cooling performance.
A frequency range of about 20KHz to 80KHz is preferred.

To explain the case where a glass plate is strengthened by liquid cooling using the apparatus of the present invention, the glass plate to be strengthened is suspended by a hanger, or conveyed horizontally by rolls, or conveyed vertically or diagonally, until the strain point of the glass plate is As mentioned above, heat the glass plate to a temperature below its softening point, for example 560℃ to 700℃ in the case of soda lime glass plates, and then heat the glass plate to a temperature below the softening point, and then heat it to a temperature below the softening point, for example, about 560℃ to 700℃ in the case of a soda lime glass plate. A heated glass plate is immersed between opposed ultrasonic vibration elements in a cooling liquid tank as shown in Figures 1 to 4 to be rapidly cooled. Also, when the glass plate is immersed, after being immersed, or before being immersed again, an ultrasonic vibration element in the cooling liquid tank is oscillated, and when the glass plate is immersed, ultrasonic waves are applied to the glass plate for a predetermined period of time. is irradiated and ultrasonic liquid cooling is applied. Then, it is taken out from the cooling liquid bath and washed.

In addition, examples of glass articles to which the present invention can be applied include glass tubes, glass containers, glass tableware, glass appliances, optical glass products, and various other glass articles in addition to glass plates.

As described above, according to the present invention, a plurality of unit plates of ultrasonic vibration elements are provided facing each other on the side surface of the cooling liquid tank, and the area between the unit plates can be interpolated by the opposing unit plates. Therefore, uniform ultrasonic vibration can be applied to the glass plate immersed in the cooling liquid bath, and uniform reinforcement can be applied to the glass plate. In addition, the ultrasonic diaphragm that covers the entire glass plate to be strengthened is not made as a single piece, but is made into a unit, and moreover, multiple pieces are used. It is possible to improve the large difference in amplitude that occurs and the non-uniformity of the sound pressure distribution due to the occurrence of split vibration. Furthermore, since a diaphragm in which the ultrasonic vibration elements are integrated into a unit is used, maintenance of the diaphragm is convenient.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a liquid cooling strengthening device for glass articles according to a specific example of the present invention, FIG. 2 is a sectional view taken along the line X-Y of the device shown in FIG. 1, and FIG. 3 is a front view of this device. FIG. 4 is a rear view of this device, FIG. 5 is a front view of a liquid cooling strengthening device for glass articles according to another specific example, FIG. 6 is a side view of the device shown in FIG. 5, and FIG. 7 is another example. FIG. 2 is an explanatory diagram of a liquid cooling strengthening device for glass articles according to two specific examples. 1: Liquid cooling strengthening device for glass articles, 2: Cooling liquid tank, 3: Ultrasonic vibration element, 4: Ultrasonic diaphragm,
5: Glass plate, 6: Hanging hand.

Claims (1)

[Scope of Claims] 1. In a liquid cooling strengthening apparatus for glass articles, which strengthens a glass article by immersing the glass article heated to a temperature above the strain point and below the softening point in a cooling liquid bath, at least one of the glass articles in the cooling liquid bath is 1. A liquid cooling strengthening device for glass articles, characterized in that ultrasonic diaphragms each having a plurality of ultrasonic diaphragms formed into units on opposing sides are arranged facing each other so as to interpolate with each other. 2. A liquid cooling strengthening device for glass articles according to claim 1, characterized in that an ultrasonic diaphragm having a plurality of ultrasonic vibrating elements as a unit is arranged obliquely on a wall surface in a cooling liquid tank. . 3. A liquid cooling strengthening device for glass articles according to claim 1, characterized in that the ultrasonic diaphragms are opposed to each other with a difference of about one wavelength.