JPS5852930B2 - Manufacturing method of partially tempered glass - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing partially strengthened glass, and more particularly to a method for producing partially strengthened glass by immersing heated glass in a cooling liquid to rapidly cool it and heat-treating the glass.

In recent years, there has been a trend in the use of laminated glass instead of tempered glass for the front windshield of automobiles.On the other hand, research has been conducted to reduce the weight of vehicles in order to save energy, and there is a demand for thinner glass sheets.

When using thin laminated glass for the front windshield of an automobile, it is desirable to use tempered glass because the thinness of the glass results in insufficient rigidity and strength.

However, if tempered laminated glass is broken, the forward view will be blocked, so laminated glass with partially tempered glass on the interior side is the best option to ensure visibility and to ensure the safety of the driver and passengers. desirable.

This partially tempered glass is manufactured by blowing air onto the parts of the glass surface that have been heated above the strain point and below the softening point to give different cooling rates to different parts of the glass for thick plates of 4% or more. , has been put to practical use in the front windshield of automobiles, etc. However, the above method lacks cooling capacity for thin sheet glass with a thickness of 3% or less, and cannot be applied as a manufacturing method for partially tempered glass. The manufacturing method for tempered glass has not been established.

An object of the present invention is to provide a method for producing thin partially tempered glass suitable for thin laminated glass used to reduce the weight of automobile front windshields.

The present applicant previously wrote in Japanese Patent Application No. 51-51329,
When strengthening glass articles by liquid cooling, we proposed a method in which ultrasonic vibrations are applied to the cooling liquid, and the glass, which has been heated to a temperature above the strain point and below the softening point, is immersed in the cooling liquid to strengthen it.

This method significantly increases the compressive stress on the glass surface and the bending strength of the glass compared to the case of strengthening with a coolant that is not subjected to ultrasonic vibration, and is a suitable method for strengthening glass articles. .

The present invention was discovered as a result of further research, and its feature is that glass heated above the strain point and below the softening point is heated to a temperature above the strain point and below the softening point, and then a cooling liquid is applied to the glass surface to create partially different strengths. The purpose is to partially strengthen the glass by rapidly cooling it while applying ultrasonic vibrations.

Examples of glass that can be applied to the present invention include plate glass container glass, glass for scientific use, etc., and it is particularly suitable for thin glass of 3 mm or less, which is difficult to strengthen by air blowing, and for other thick glass. It can also be applied to strengthen partially modified glass articles.

Further, as the cooling liquid, vegetable oil, mineral oil, molten metal, synthetic oil, liquid paraffin, etc. can be used, and the cooling liquid can be heated as appropriate.

To carry out the method of the present invention, the above-mentioned cooling liquid is placed in a cooling tank large enough to immerse the glass, and ultrasonic vibrating elements are placed at appropriate locations in the cooling tank to immerse the heated glass. When immersed, ultrasonic vibrations of different intensities are applied to the glass surface via the cooling liquid.

In the present invention, as a method of imparting ultrasonic vibrations of different intensities locally to the surface of the glass immersed in the cooling liquid, for example, an appropriate position in the cooling tank where the ultrasonic vibrations can be irradiated perpendicularly to the glass surface is used. Ultrasonic vibrations are emitted onto the glass surface by an ultrasonic vibration element placed on the glass surface, and ultrasonic sound absorbing material or ultrasonic reflection material of a desired shape is placed parallel to the glass surface and near the glass surface on the side of the ultrasonic vibration element. The ultrasonic vibrations are partially shielded by a mask plate made of material, and the glass surface corresponding to this masked part is not subjected to ultrasonic vibrations, or even if it is applied, the ultrasonic vibrations are applied weakly compared to other parts. There are ways to make it look like this.

Another method is to place an ultrasonic vibrating element with a desired shape in a cooling tank and irradiate the glass surface with ultrasonic waves perpendicularly. will be granted.

Furthermore, there is a method in which two or more of the above elements are arranged and ultrasonic vibrations of different intensities are irradiated perpendicularly to the glass surface from each element.

Another method is to generate standing waves in the cooling tank.

For example, as shown in FIG. 1, an ultrasonic vibration element 2 is directed upward at the bottom of a cooling tank 1 to emit ultrasonic waves, and the reflected liquid reflected on the liquid surface 3 and the irradiated waves mutually interact. Interfering standing waves 4
When formed, the intensity of ultrasonic vibration is strong at the antinode part of the standing wave (and the intensity of ultrasonic vibration is weak at the node part), and a layered sound field 5 with different intensities of ultrasonic vibration is formed.

When glass is placed vertically into this cooling tank, parts of the glass to which ultrasonic vibrations are strongly applied and parts to which ultrasonic vibrations are applied weakly appear alternately in band-like shapes.

Furthermore, when the glass is placed in the cooling tank at an angle from the vertical direction, ultrasonic vibrations are imparted to the glass in a band-like width that increases depending on the angle of inclination.

Further, as shown in FIG. 2, an ultrasonic vibration element 2 is arranged on the side surface of the cooling tank 1, and the ultrasonic vibration element 2 is radiated in the horizontal direction, and the reflected wave and the irradiated wave reflected at the opposing surface mutually interfere with each other. A standing wave 4 is formed in the cooling tank.

In this method, there is a layer with strong ultrasonic vibration and a layer with weak ultrasonic vibration in the vertical direction.
is formed, so if the glass is immersed horizontally, the same effect as above can be obtained.

Further, when the glass plate 6 is immersed at an angle as shown in FIG. 3 in the liquid in which standing waves have been formed by the above method, a wide belt-shaped ultrasonic vibration of different intensities is applied to the glass plate.

When the glass is immersed in this way, ultrasonic vibrations of different intensities are radiated to the glass surface using the method described above, and the glass is heated to a temperature above the strain point and below the softening point. When the glass is immersed in a cooling bath to be rapidly cooled, the glass surface to which ultrasonic vibrations have been strongly applied will experience a larger compressive stress than other surfaces, resulting in a glass product with partially different levels of reinforcing dust.

Example 1 Silicone oil (produced by Toshiba Silicon Co., Ltd., trade name: Toshiba Silicone Oil Y)'-33) was used as a cooling liquid in a cooling tank (8).
0% x 500% x 560% depth), a 150x width ultrasonic vibration element was placed in the center of the side (500% surface) of this cooling tank, and ultrasonic vibrations with a frequency of 29 KHz were radiated in the horizontal direction. 100% heated to 680℃
300x300%, 2.4x thick float glass plate
It was immersed so that the % sides were horizontal and the center of the glass surface was subjected to ultrasonic vibrations with a width of 150%, and was rapidly cooled.

(Both ends of the glass are each 75 sq. wide and no ultrasonic vibrations are applied.

) A glass plate that had been cooled to room temperature was taken out, and the compressive stress and fragment density on the glass surface were measured for the part that was cooled while applying ultrasonic vibration and the part that was cooled without applying ultrasonic vibration. As a result, the parts that were cooled while being irradiated with ultrasonic waves along the lines shown in Table 1 had larger surface compressive stress and fragment density than other parts, and the degree of strengthening was different in parts of a single sheet of glass. It turned out that.

Example 2 As shown in Fig. 4, ultrasonic vibration elements 2 with a width of 150X are arranged on the side of the cooling tank 1, one on each 500 sides, and when ultrasonic vibrations are radiated in the horizontal direction, they overlap each other. The cooling liquid used in Example 1 is placed in this cooling tank, and the output of one ultrasonic vibration element is weakened to 75% of the output of the other element and irradiated.

A 100% x 300% 2.4x thick float glass plate heated to 680°C was immersed in this and rapidly cooled.

(During immersion, ultrasonic vibration was strongly applied to the right half of the glass plate (100% x 150%), and weakly applied to the left half.

) The above glass plate was taken out from the cooling fan to room temperature, and the compressive stress on the glass surface and glass fragment density were measured for the parts to which ultrasonic vibration was strongly applied during cooling and the parts to which ultrasonic vibrations were applied weakly. As shown in Figure 2, the parts to which ultrasonic vibrations are strongly applied during cooling have higher surface compressive stress and fragment density than the parts to which ultrasonic vibrations are weakly applied, and are partially strengthened in a single sheet of glass. It turned out that the degrees were different.

Example 3 Using the cooling liquid and cooling tank used in Example 1, an ultrasonic vibration element was placed on the bottom of the cooling tank and radiated in the vertical direction to form standing waves in the cooling tank as shown in Figure 1. A float glass plate heated to 680°C was vertically immersed and rapidly cooled.

The glass above the cooling layer was taken out to room temperature and the surface compressive stress was observed. As a result, it was found that there were alternating band-shaped areas with strong surface compressive stress and areas with weak surface compressive stress.

Example 4 Using the cooling liquid and cooling tank used in Example 3, a standing wave was formed in the same manner as in Example 3, and a float glass plate heated to 680°C was immersed at an angle of 45 degrees from the vertical. As a result of observing the compressive stress on the surface of the cooling layer glass at room temperature, regions with strong compressive stress and regions with weak compressive stress were alternately present in a band shape, and the width of this band shape was wider than in Example 3.

As explained above, according to the present invention, it is possible to obtain a thin plate, for example, partially tempered glass having a thickness of 3X or less, which has been considered difficult in the past.

Note that the present invention is not limited to this, and can be applied to, for example, strengthening glass articles having different plate thicknesses.

That is, if ultrasonic vibration is strongly radiated to a thin part, it can be strengthened in the same way as a thick part.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of an example of a cooling tank used for carrying out the present invention. FIG. 2 is a longitudinal sectional view of another cooling tank used to carry out the present invention. FIG. 3 is a cross-sectional view of the glass plate immersed in the cooling tank of FIG. 2 at an angle. FIG. 4 is a plan view of another example of a cooling tank used to carry out the present invention. 1...Cooling tank, 2...Ultrasonic vibration element, 3...Cooling liquid level, 4...Ultrasonic standing wave, 5... ... Ultrasonic sound field of different intensities formed by standing waves, 6 ... Glass plate.

Claims (1)

[Claims] 1. Glass that has been heated to a temperature above the strain point and below the softening point is rapidly cooled while applying ultrasonic vibrations of different intensities to the glass surface through a cooling liquid. A manufacturing method for partially tempered glass, which is characterized by its strength. 2. Ultrasonic vibrations applied to the glass surface are partially shielded by a mask plate in the vicinity of the glass surface, so that the ultrasonic vibrations are applied to the glass surface with different intensities locally. A method for producing partially tempered glass according to claim 1. 3 Claims characterized in that a plurality of ultrasonic vibrating elements emit ultrasonic waves of different intensities to the coolant, thereby imparting ultrasonic vibrations of partially different intensities to the glass. A method for producing partially tempered glass according to item 1. 4. Partial reinforcement according to claim 1, characterized in that a standing wave of ultrasonic vibrations is formed in the coolant so that ultrasonic vibrations of different intensities can be imparted to the glass partially. Glass manufacturing method.