JPS5891042A - Tempered glass - Google Patents

Abstract

PURPOSE:To prevent the formation of dangerous splines when sheet glass splinters by heating a flat glass of a small thickness then air-cooling the specific range thereof from the top and rear surface to form areas having higher compressive stress and lower compressive stress separately. CONSTITUTION:A thin flat glass 9 of 2.4-4.0mm. thickness is heated to 610-700 deg.C and is conveyed by means of guiding members 10 to between many upper spraying nozzles 5 and lower spraying nozzles 8. Thereafter cooling air is sprayed from upper and lower spray nozzles onto the top and rear surface of the plate 9 to form areas 11 where surface compressive stresses are as large as 1,300kg/ cm<2> and areas 12 where said stresses are as small as 1,020kg/cm<2> at 10-30mm. intervals in a belt shape. The differences in the compressive stresses between both surfaces are set at 80-220kg/cm<2> and the max. main stress difference in the areas 12 where the surface compressive stresses are small is set at >=80kg/ cm<2>. When broken, this flat glass splinters to 5X5cm sizes and this flat glass is utilized for window glass of automobiles as tempered glass that does not produce any dangerous and sharp splines.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tempered glass used as a window glass for automobiles, hildings, etc.

Generally, when the windshield of a car breaks due to an accident, if the fragments are large, there is a risk of causing lacerations to the occupants, while if the fragments are too small, there is a risk of them entering the body. :1 The long thin pieces called splines can be said to be the same as knives and are extremely dangerous.

Therefore, tempered glass used for automobile windshields and the like must satisfy various standards. For example, in the European Economic Community standards, 5
The number of crushed pieces in the range of 5 cA is 50 to 300,
It states that splines with a length of more than 60 degrees must not occur.

By the way, conventional tempered glass is made by rapidly cooling the high-temperature glass surface relatively uniformly to generate a relatively uniform surface compressive stress on the surface.

If such conventional tempered glass has a thickness of at least a certain level, specifically 4 holes or more, the number of fractures will not meet the above standards even if it is used for automobile windshields, etc. You can do it.

However, in recent years, there has been an increasing demand for the use of thin tempered glass for automobile windshields due to demands for weight reduction. When using thin tempered glass manufactured by the conventional method, there is a problem that the above specifications cannot be satisfied.

In view of the above-mentioned conventional problems, the present inventor has devised the present invention to effectively solve the problems. The trenches are there to provide thin tempered glass.

In order to achieve this object, the present invention consists of plate glass having a thickness of about 2.4 mm to about 40 mm, with areas of high surface compressive stress and areas of low surface compressive stress arranged alternately in a band shape, and Set the interval to 1
0 city to 30 degrees, and the above surface compressive stress]
, from 020r to 1300r, and has at least one surface with a difference in surface compressive stress of 80 to 220r, and further has a maximum principal stress difference of 8
The gist is that it is 0 to more than 0.

A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 shows a part of an apparatus for manufacturing tempered glass according to the present invention. In the figure, reference numeral 1 is a frame body, which is installed on the upper part of the frame body 1, and an upper unloading part 3 is provided on the supporting plate 2, and the lower part of this unloading member 3 is filled with cooling air (- 4
A nozzle 5 is installed vertically on the bottom surface of the box 4 for blowing cooling air. Further, a lower eyebrow lowering member 6 is provided on the bottom plate 1a of the frame body 1, the upper part of this lowering member 6 is filled with cooling air similar to that described above, and one box 7 is removed. Nozzle 8 is installed upright in the blower.

As shown in FIG. 2, the nozzles 5 in the upper blower are regularly arranged in a straight line in the vertical and horizontal directions, and the vertical arrangement coincides with the advancing direction of the glass plate 9. I try to do that. In this embodiment, the nozzle 5 has an inner diameter of 3.5 mm, and the distance W1 between the nozzles 5 in the vertical direction, that is, the direction in which the glass travels, is approximately 1.
2, and the lateral distance W2 is in the range of 10 nm to 30 nm. The arrangement of the lower spray nozzles 8 may be the same as the arrangement of the upper spray nozzles 5, or may be a conventional uniform cooling nozzle arrangement in which the vertical nozzle arrangement is inclined in the traveling direction of the sheet glass.

Approximately 610 to 700°C from the left side of the apparatus shown in Figure 1.
The plate glass 9 heated to
Transport between. At this time, the thickness of the plate glass 9 is 4 ra
Cooling air is blown onto the glass surface from the nozzles 5 and 8 at a pressure of 940 to 1230 mm H2O for n, and 1860 to 2040 rrrm H2O for 3,4 brains.

The tempered glass thus obtained has at least one surface with a high surface compressive stress 11 as shown in FIG.
... and portions 12 with low surface compressive stress are arranged alternately in a band shape, and the interval t1 between the band portions 11 with high surface compressive stress is 10 to 30 mm, and the width t2 of the band portion 11 is as described above. The interval t1 is less than or equal to 3. - & r, = The compressive stress on the tempered glass surface is at least 1300'\l at the maximum and 1020Y at the minimum! The difference in stress between the portion 11 with high surface compressive stress and the portion 12 with low surface compressive stress is 80 to 220 Y! The maximum principal stress difference is 80 or more even in the portion 12 where the surface compressive stress is low.

In the above, plane stress (maximum principal stress) occurs in the A direction, that is, the direction perpendicular to the band, in the portion 11 with high surface compressive stress, and plane stress (maximum principal stress) occurs in the portion 12 with low surface compressive stress. It occurs in the B direction, that is, parallel to the strip. When tempered glass is broken, the cracks propagate in the direction perpendicular to the plane stress, so the cracks propagate straight in the length direction in the part 11 where the surface compressive stress is high; becomes thinner and no splines occur. t rx low surface compressive stress area 1
In No. 2, the crack propagates straight in the direction perpendicular to the band-shaped portion, but since the portion with high surface compressive stress is destroyed first, the crack stops there, and no large fragments are generated.

Therefore, a portion 11 with high surface compressive stress and a portion 1 with low surface compressive stress
2 to a predetermined value, and the portion 11
, 12-1], etc., it will be reinforced to a certain standard, for example, the number of fractures is 50 pieces/5ci x 5cm to 300 pieces/5cm x 5cm, and a spline with a length of 60 cities or more will not occur. You can get the glass.

The effects of the present invention will be explained below based on the following [Table] showing specific experimental results and Figures 4 to 6 which are diagrams of this [Table].

-7- 233- Experiments (conducted on tempered glasses with ζ dimensions of 500 mm x 1100 m+n and thicknesses of 4.0 pieces, 35 mm, and 24 mm, respectively, of which Figure 4A, Figure 5A, and Figure 6A Figure 4 shows the relationship between the surface average compressive stress (the average of the maximum surface compressive stress in areas with high surface compressive stress and the minimum surface compressive stress in areas with low surface compressive stress) and the number of fractures. Figure 5B
, and FIG. 6B shows the relationship between the surface compressive stress and the number of splines corresponding to the thickness of each glass.

As is clear from the above [Table 1 and FIGS. 4 to 6], in order to make the number of fractures 50 to 300, the thickness of the glass should be 2.
4 rrrm to 40 throat, area with high surface compressive stress 11
The interval between ... is 10y++m to 30wn, and the maximum value of the high surface compressive stress is 1300'V or less,
In addition, it is necessary that the minimum value of the low surface compressive stress portion be 1020 or more. Furthermore, it is necessary to keep the above range in order to avoid including splines with a length of 60 or more.

When the difference in surface compressive stress exceeds 220 z, the number of fractures exceeds 300, as shown in the table, and when the difference in surface compressive stress becomes 80 z or less, the length exceeds 60 z. Since a spline is formed, the surface compressive stress difference is 8
It is preferably 0 to 220 shi. Furthermore, as is clear from the table, it is appropriate that the maximum principal stress difference in the portion 12 with low surface compressive stress is 80 or more.

As is clear from the above explanation, according to the present invention, a sheet glass having a thickness of 2.41 to 40 sq. The interval between the high-stress band parts is 10 mm to 301 mm, and the surface compressive stress is 102 +) short to 13 mm.
00～, the difference in surface compressive stress was set as 807.2 to 220～, and the maximum principal stress difference in the area where the surface compressive Lls force is low was set as 80 or more, so the number of fractures was 50 pieces/ 5 cm x 5 cm to 300 pieces 75 cm x 5
cm, and the length is 6゜rrr.
A spline on rn, IJ, does not occur. Furthermore, it can be made to conform to various ■Φ standards required for reinforced glass, and can also be used for automobile window glasses, offering many advantages such as weight reduction.

[Brief explanation of the drawing]

The drawings show preferred embodiments of the present invention and experimental results, and Fig. 1 is a side view showing a part of the apparatus for manufacturing tempered glass according to the present invention, and Fig. 2 is a side view showing a part of the apparatus for manufacturing tempered glass according to the present invention. Fig. 3 is a printed view of the tempered glass according to the present invention, and Fig. 4A shows the relationship between the number of fractures and surface compressive stress of 40 wa tempered glass. Diagram, Figure 4B is a diagram showing the relationship between the number of splines and surface compressive stress for tempered glass with a thickness of 4.0mm, Figure 5A is a diagram showing the relationship between the number of splines and surface compressive stress for tempered glass with a thickness of 3.5 mm. Diagram similar to A; Figure 5B is a diagram similar to Figure 4B for 3.5 mm thick tempered glass; Figure 6A is 2.4 + nm thick.
Diagram similar to Figure 4A for thick tempered glass, Figure 6
Figure B is Figure 4B for 2.41mm thick tempered glass.
This is a diagram similar to . In the drawing, 5.8 is the blowing nozzle for cooling air, 9 is the plate glass, 11 is the area with high surface compression stress, and 12 is the surface compression t.
Low part of V-8 power, 1. is the interval between areas with high surface compressive stress. Patent Applicant: ``1 Plate Glass Co., Ltd. Interest Agent Patent Attorney 2 1) Yongbu Patent Attorney Kunihiko Ohashi 4th Prisoner (A) u゛yysufr&5QxIIO○ (B) Cooking -msu(A) n゛'valsoqg501)xllo.

Claims (1)

[Claims] Areas with high surface compressive stress with a maximum value of 1300 V or less and areas with low surface compressive stress with a minimum value of 1020 V or more are arranged alternately in a band shape at intervals of 10 Tran to 30 mm. Tempered glass having a thickness of 2.4 rrtm to 4.0 inches, having at least one surface with a difference of 805 to 220 mm, and having a maximum principal stress difference of 80 mm or more in the portion with low surface compressive stress.