JP2996828B2 - Manufacturing method of sheet glass molded body - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a sheet glass molded article for use in buildings and general industries.

[0002]

2. Description of the Related Art In recent years, sheet glass has been widely used for various purposes such as windows, show windows, wall materials, doors, partitions, display cases, aquariums, furniture, etc. for building exterior and interior or for general industry. ing. Conventionally, corners of windows, show windows, display cases, etc. are joined at a predetermined angle using a frame of metal, wood, plastic, or the like, and the joint between each sheet glass and frame is made of silicone rubber or the like. Were adhered by a caulking material and a sealing material. However, this method has the disadvantage that the appearance and transparency of the corners are poor due to the presence of the frame, and the cost is increased when using a stainless steel frame or the like for the corners, which is economically unfavorable. . On the other hand, there is a method in which two glass sheets are butted without using the above-mentioned frame, and the butted portions are joined with a caulking material such as silicone rubber and a sealing material. However, this method does not improve the appearance and transparency of the corner portion, and the joined butted portion is weak in strength. In addition, there is a drawback that the service life of the joint is relatively short because the weather resistance of the caulking material and the sealing material is limited. As a method of removing the above-mentioned defect, it is known that a single sheet of glass is subjected to thermal processing to form a bent portion having a predetermined angle. For example, a normal float plate glass is horizontally placed on a mold having a bent portion having a predetermined angle, and the entire plate glass is heated to about 500 to 580 ° C.
Heating to a certain degree and forming on a mold by gravity or other external force to form a predetermined bent portion is performed. However, in this method, the bent portion has a relatively large radius of curvature (for example, when the thickness of the glass sheet is 4 mm, the radius of curvature is at least about 35 to 40 mm), and the window, the water tank,
When used for applications such as show windows and display cases, it is not preferable because the object looks greatly distorted. In addition, since the vicinity of the bent portion of the sheet glass is exposed to a high temperature equal to or higher than the annealing temperature over a considerable range, distortion occurs in the vicinity of the bent portion of the formed sheet glass over a considerable range, and the flat portion has a large defect. I was FIG. 4 shows an example of a cross section in the bending direction of a sheet glass having a bent portion formed by the above method. Bent part B ₁
Is about 10 times the thickness of the sheet glass, and AB ₁ and AB ₂ portions are flat portions A ₁ , A ₂
And bending a thickness inferior portion of the optical properties of the strain that occurs over a length of several times the d as an intermediate portion of the moiety B _1, also results also A ₁ and A ₂ moiety is a plan exposed to high temperatures In addition, flatness before thermal processing cannot be maintained, and there is optical perspective distortion and reflection distortion.

Further, after forming a groove-shaped cut line at a place on the sheet glass to be bent, the entire sheet glass is heated to a temperature higher than the annealing point, and the sheet glass is bent at a predetermined angle along the cut line. There is known a method of forming a sheet glass. However, since the cut portion after molding is not fused, the mechanical strength of this portion is very small, and it is not suitable for use for construction and general industry.
Further, if the cut is made small in order to increase the strength of the bent portion, the time required to bend the sheet glass to a predetermined angle becomes extremely long, and the glass is damaged during bending, which is not preferable. If the heating temperature is increased in order to shorten the bending time and prevent breakage of the glass, there is a disadvantage that the flat portion of the formed bent sheet glass is distorted.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for producing a sheet glass molded article having excellent mechanical strength of glass at a bent portion.

[0005]

SUMMARY OF THE INVENTION According to the present invention, at least one linear bending is performed by providing a groove-shaped score line on a sheet glass and bending the sheet glass along the score line with the score line inside. In the method for producing a sheet glass molded body having a plurality of flat portions having a portion, a line is drawn by using a conductive material at or near the cut line, and the line is supplied by supplying power to the line. A method for producing a sheet glass molded body, characterized in that the glass of the strip is heated to a temperature equal to or higher than the softening point of the sheet glass and the glass of the cut line is fused.

That is, in the method of the present invention, a line is drawn using a conductive material at or near the cut line. In the embodiment in which the cut line is formed in the sheet glass, preferably, a line of the conductive material is drawn in a bent portion in the cut line, on a glass surface adjacent to the cut line and / or on a glass surface opposite to the cut line. . In the present invention, a method of providing a grooved score line in a sheet glass is known. For example,
It can be created using a V-cut machine for sheet glass (manufactured by Suzuki Shokai Co., Ltd.). The number of the cut lines is the same as the number of bent portions of the sheet glass molded product required as a product, and at least one cut line is provided on one sheet glass. When a plurality of cut lines are provided, they are provided in parallel or non-parallel with each other depending on the shape of a desired product. Examples of the cross-sectional shape of the cut include a triangle and a quadrangle, and a triangle is preferable. The dimensions of the cross section are appropriately determined by the thickness of the sheet glass, the bending angle of the sheet glass molded body, and the like. The depth of the cut is usually determined by the radius of curvature of the outer periphery of the curved surface in a direction perpendicular to the bent portion of the formed sheet glass body after bending. The depth of the cut is preferably 1/5 to 1/1 of the thickness of the sheet glass.
It is twice. The angle of the cut line having a triangular cross section toward the opening is preferably equal to the bending angle of the formed sheet glass molded body. For example, when a 5.0 mm-thick plate glass is bent at a right angle, the angle toward the opening is a right angle and the depth is 2.0 mm.
Having a triangular cross-section. The score line is usually formed only on the surface that is inside when the sheet glass is bent.

[0007] The lines of the conductive material are drawn, for example, at the positions shown in FIG. FIG. 1 is a cross-sectional view showing, in an enlarged manner, the vicinity of a cut line or a joint in a sheet glass. The thick black line in the figure indicates the cross section of the filament of the conductive material, however, the dimensions are inaccurate for the sake of illustration. In embodiments where the score lines are cut into the glass sheet, the score lines typically have a triangular cross-section. For example, the line is drawn on the surface of the groove of the cut line as shown in FIG. Next, when electricity is supplied to the striated portion, the glass surface becomes high temperature due to Joule heat, and the striated portion is in a molten state to form a melting line.
When the energization is continued, the glass below the melting line is in a molten state and has conductivity. The conductive material burns, volatilizes, or diffuses into the glass at elevated temperatures, and current gradually flows through the molten glass in the conductive glass below the melting line, which is further heated by Joule heat, which in turn Electric current also flows through the lower layer, causing heating. As a result, the glass is heated to a temperature equal to or higher than the softening point along the longitudinal direction of the score line. Therefore, bending can be performed. Further, since the glass in the groove of the cut line is molten, both surfaces of the groove are completely fused when the glass is bent. Therefore, the strength of the product is large. At this time, the conductive material in the groove burns, volatilizes, or diffuses into the glass, and does not hinder the fusion of the glass.

In another embodiment, the streaks are in the vicinity of the score line, ie, on the left and right glass surfaces adjacent to the score line (B), on the glass surface opposite the score line (C), or both ( D). In this case as well, heating is caused by energization in the same manner as described above. As a result, the glass near the cut line is heated to a temperature higher than the softening point through the front and back to be in a molten state, and both sides of the groove after bending are completely fused.

[0009] In another embodiment, the line is formed on the left and right glass surfaces adjacent to the cut line and on the left and right glass surfaces adjacent to the cut line (E). It can be drawn on the surface and on the glass surface opposite to the cut line (F), or on the groove surface of the cut line and on the glass surface opposite to the cut line (G). The glass in the vicinity of the cut line and in the groove of the cut line is sufficiently softened and melted by energization, and both sides of the groove after bending are completely fused. Particularly in a thick sheet glass, it is effective because the groove surface and the bent portion can be quickly heated and the radius of curvature of the bent portion can be reduced.

[0010] The line can be drawn at the bottom (H) of the groove of the cut line, or at (I) where a separate cut line is provided at a bent portion on the glass surface opposite to the cut line. In each case, it is preferably used for relatively thick sheet glass, which allows the softening melt to be very narrow. Regarding (I), since the cut line created for drawing the line is outside the bending of the sheet glass, it is stretched and flattened and disappears after molding.

In the above description, the groove of the score line has a triangular cross section, but is not limited to this. For example, in the above (A) to (I), the score line can have a rectangular cross section. (J) shows a case corresponding to the above (C). Such a mode of enlarging the cross section of the groove is particularly effective when the curvature radius of the bent portion is set to be equal to or less than the plate thickness particularly in the case of a thick plate glass. However, it is preferable to determine the shape and size of the groove according to the bending angle so that there is no gap in the groove after bending.

[0012] In a preferred embodiment, the line has an uneven width or thickness or is discontinuous along its longitudinal direction, and the line is fed along the line by supplying power to the line. A method of causing an arc discharge and heating the glass at the location to a temperature higher than its softening point is used. According to this method, since electrical resistance is large at a portion or a break point where the width or thickness of the filament is small (hereinafter simply referred to as a narrow portion), arc discharge continuously occurs across the narrow portion. Then, the temperature of this portion becomes high, and the glass melts to form a molten spot. Since the conductive material burns, volatilizes, or diffuses into the glass in the same manner as described above, the amount of the conductive material at the portion in contact with the molten spot in the wide (or thick) striated portion is reduced, As a result, arc discharge also occurs at this point. As a result, the melting spots are finally connected to each other to form a melting line. The melting line is heated to a high temperature of 700 ° C. or more, generates sodium ions, the glass exhibits good conductivity, and current flows through the surface of the glass. Further over time, the conductive material further dissipates and the arc discharge at the glass surface is eliminated. At this time, the temperature rise on the glass surface is hindered by heat radiation, and the temperature immediately below the melting line becomes higher than the glass surface. The current will flow inside the glass just below the hotter, more conductive melting line. As a result, the inside of the glass immediately below the melting line is heated by Joule heat and is brought into a molten state. By this repetition, a current also flows through the lower layer, and heating occurs. As a result, the current flows intensively inside the glass immediately below the line, and the glass is in a molten state. According to actual observation, the glass is rapidly melted from the surface toward the inside. Regardless of the details of the phenomena, the glass is in any case heated to a temperature above the softening point very locally in the striated portion, so that the parts of the sheet glass to be bonded to one another are completely fused. The above phenomenon is completed in a very short time (for example, several seconds to 30 seconds).
Therefore, the above-mentioned sheet glass molded body can be manufactured in an extremely short time.

Since the present invention uses the above-described electric heating, it can be heated very locally in the striated portion. Therefore, the heat transfer in the glass plane direction is small, and the glass plane portion near the bent portion does not rise to the softening point. Therefore, it is possible to manufacture a sheet glass molded article having an extremely good flatness of the flat portion up to the vicinity of the bent portion.

In the present invention, the electric heating by the power supply to the above-mentioned wire portion is usually performed before bending, but is not limited to this. For example, in an embodiment in which a cut line is formed in a sheet glass, according to the above-described conventional method, the entire sheet glass is heated to a temperature not lower than the annealing point, and the sheet glass is bent at a predetermined angle along the cut line. The cut line portion can be softened and melted and fused by energizing the wire. Here, the annealing point of the sheet glass generally means a temperature at which the viscosity of the glass corresponds to about 1013 poise.

In the method for producing a molded sheet glass of the present invention, a known conductive material can be used as a conductive material for drawing a line. The conductive material is preferably a conductive paint such as a carbon-based material such as graphite or a metal-based material such as silver, copper, nickel, chromium, palladium or platinum, an oxide-based material such as tin oxide, or a carbide-based material such as silicon carbide. Or alloys such as iron-nickel-chromium alloys,
Copper-tin alloys, aluminum alloys and the like can be mentioned. Bunny Height (F-525W-1) manufactured by Nippon Graphite Shoji Co., Ltd. is used as a carbon-based conductive paint, and H9100 manufactured by Hokuriku Paint Co., Ltd. or D-1230 (Fujikura Kasei Co., Ltd.) is used as a silver-based conductive paint. Kai) and the like. From among these, where to draw the line, the shape and size of the groove of the cut line, the length, width or thickness of the line, adhesion to glass, coloring of glass by diffusion of metal ions, operating voltage, etc. Depending on the situation, it can be appropriately selected.

The conductive paint in paste form is applied on a glass sheet by screen printing, letterpress printing, spraying or transfer. Metal or alloy, metal spraying method,
It can be applied by a CVD or pyrolytic method. In the metal spraying method, a mask having a slit corresponding to a filament is placed on a glass plate, the metal is used as a conductive material, the metal is melted by an electric arc or a flame, and the metal is blown out from a nozzle by compressed air. And apply thermal spray on the glass sheet to draw a line. In any of the above methods,
The drawn lines can be printed in close contact with the surface of the sheet glass and accurately at predetermined locations. Screen printing and metal spraying are preferred for accuracy and simplicity.

The width of the line differs depending on the position where the line is drawn, the shape and size of the groove of the cut line, the thickness of the sheet glass, the bending angle, the working voltage, the shape of the line, and the like. In a mode in which a score line is formed in a sheet glass, a line is drawn on a groove surface of the score line ((A), (E), (F) or (G) in FIG. 1).
Can be drawn on the entire groove surface or on a part of the groove surface. When the glass is relatively thick, drawing a line of a conductive material at the bottom of the groove makes it possible to make the softened and fused portion extremely narrow and to perform sufficient heating (H in FIG. 1). When drawing on the glass surface adjacent to the cut line ((B) in FIG. 1)
Alternatively, when drawing on a bent portion on the glass surface opposite to the cut line (FIGS. 1C and 1J), the thickness is preferably 0.2 to 3 times the thickness of the sheet glass at the cut line. And particularly preferably 0.5 to 1.0 times. In the case of drawing a plurality of filaments ((D), (F) and (G) in FIG. 1), heating is sufficiently performed even if the width of each filament is narrower than the above. In any of the above cases, if the width of the filament is too wide, the range of the sheet glass to be heated near the softening point is too wide, which causes distortion in the flat portion of the sheet glass near the bent portion, which is not preferable, and which is too narrow. In addition, sufficient heating cannot be performed, and the fusion of the glass at the bonding portion of the plate glass is insufficient, which is not preferable.

The thickness of the wire varies depending on the type of the conductive material, the method used for drawing the wire, or the place where the wire is drawn. However, if the glass can be stably heated to a predetermined temperature for a predetermined time. Well, preferably 0.1 to number 1
00 μm, for example, 10 to 1 in the screen printing method.
00 μm, and preferably 30 to 300 μm in the thermal spraying method.

Further, examples of the lines having a non-uniform or discontinuous width along the longitudinal direction include those shown in FIG. In the figure, dimensions are in mm.
The width of the wide part of the line is preferably 0.5 to 5 m.
m, and particularly preferably 1 to 3 mm. If the width of the wide portion is less than 0.5 mm, it is not preferable because heating with required electric power cannot be performed. Also, if it exceeds 5 mm,
The range of the plate glass heated near the softening point is too wide, and the flat portion of the plate glass near the bent portion is undesirably distorted.
The width of the narrow portion of the filament is preferably 1 mm or less, particularly preferably 0.5 mm or less. If the width of the narrow portion exceeds 1 mm, arc discharge hardly occurs, which is not preferable. Further, the filament is preferably 0.1 to 3 mm,
Particularly preferably, it may be intermittent at intervals of 1 to 2 mm. If the distance exceeds 3 mm, arc discharge hardly occurs, which is not preferable. In addition, the above-mentioned striated line is preferably a repetition of a wide portion and a narrow portion, a repetition of a large portion and a small portion, or a repetition of an intermittent portion, preferably 0.3 to 10 mm in length, and particularly preferably. Is a repeating pattern having a length of 1 to 3 mm. When the repetition exceeds 10 mm, the time required for heating becomes long, which is not preferable. When the repetition is less than 0.3 mm, it is difficult to form a filament with an accurate shape, which is not preferable. The thickness of the filament depends on the type of the conductive material, the method used to draw the filament, or the location where the filament is drawn, but it is sufficient that the glass can be stably heated to a predetermined temperature for a predetermined time. , Preferably 0.1 to several hundred μm,
For example, the thickness is preferably 10 to 100 μm for the screen printing method, and 30 to 300 μm for the thermal spraying method. Further, the filament may have a changed thickness. The thickness of the portion where the thickness of the filament is large is preferably 10 to 50 μm, and the thickness of the portion where the thickness is small is preferably 5 to 15 μm. The width of the filament is preferably 0.5 to 5 mm, and the repetition of a portion having a large thickness and a portion having a small thickness is preferably 0.3 to 10 m.
This is a repeating pattern having a length of m. For example, if the width is 1.
0 mm, a line having a thickness of 30 μm at a portion having a large thickness, a thickness of 10 μm at a portion having a small thickness, and a repetition of a portion having a thickness of 1 mm at a portion having a large thickness and a portion having a small thickness are exemplified.

As a method for supplying power to the filament drawn on the sheet glass, the following method is preferably used.
That is, a method in which a solid electrode of an appropriate shape is brought into contact with the above-mentioned filament at the end of the plate glass to supply power and heat, and a conductive high-temperature gas frame for generating lithium ions or the like is brought into contact with the above-mentioned filament at the end of the plate glass to form the frame. Or a method of heating by heating, or a method of drawing a wire in a loop shape and using a high-frequency current to perform dielectric heating. In the case where the wire is drawn in the cut line and energized, a method is preferred in which a conductive high-temperature gas frame that generates lithium ions or the like is brought into contact with the wire at the end of the sheet glass, and power is supplied and heated through the frame. The power source is 50 or 6
An AC power supply of 0 Hz, a high-frequency power supply of 100 KHz to 50 MHz or a DC power supply is used. In the method using the solid electrode, any of the above-described power sources can be used. However, in the method using the conductive high-temperature gas frame, a high-frequency power source is preferable, and only the high-frequency power source can be used in the dielectric heating. The selection of the type of the power source to be used is determined in consideration of the size of the sheet glass and the like in addition to the type of the method of heating the filament. In addition, in the case where the width or the thickness is uneven along the longitudinal direction, or when the arc is discharged by supplying power to the intermittent filament, a method other than the above-described dielectric heating method can be used. The same power supply as described above is used, but the voltage must be sufficient to cause arc discharge, preferably several thousand volts to 20,000 volts, and the current is preferably 0.5 volts. ~ 2 amps.

The temperature control is performed by controlling the current, voltage, energizing time, thickness and dimensions of the sheet glass to be used, width of the line, shape and size of the groove of the cut line, the position where the line is drawn, etc. If the width or thickness of the line is uneven or intermittent, the width of the wide and narrow portions of the line, the interval between the intermittent portions of the intermittent line, and the repetition of the line It is preferably carried out by controlling the current and the conduction time in consideration of the length of the pattern and the like. Since the control factors include a number of parameters as described above, the temperature is preferably controlled by computer control, and the desired heating temperature can be achieved very easily. Normally, current is applied for 30 seconds to 5 minutes, particularly 1 to 3 minutes, and in the case of a filament having a non-uniform width or thickness along the longitudinal direction or intermittent, a few seconds to 30 seconds. Can heat several tens to several hundreds of watts per 10 cm of the length of the filament, which is sufficient.

By the above heating method, the striated portion drawn on the sheet glass is heated to a predetermined temperature. The temperature is equal to or higher than the softening point of the used glass sheet, particularly preferably in the range of softening point to softening point plus 140 ° C. If the temperature exceeds the above range, distortion occurs in the flat glass portion near the bent portion after processing, and it is not preferable from the viewpoint of economy. By this heating, the glass in the linear portion of the plate glass is melted, and the glass in the portion to be bonded is completely fused to each other. Here, the softening point of the sheet glass means a temperature at which the viscosity of the glass corresponds to about 10 8 poise and the glass is deformed by its own weight (normally about 740 ° C. for float glass).

In the present invention, the whole glass sheet is preferably at a temperature lower than the annealing point of the glass sheet, more preferably 0 to 200 ° C. lower than the annealing point of the glass sheet, particularly preferably 50 to 200 ° C. below the annealing point of the glass sheet. After heating substantially uniformly at a temperature lower by 略 100 ° C., it is preferable to supply power to the striated portion for heating. It is preferable to uniformly heat the glass sheet in advance in this way, because it is possible to prevent breakage of the glass that occurs when the wire is supplied with power and heated.

In the method of the present invention, the heating of the linear portion of the sheet glass is usually performed in air, but is not limited to this.

In the method of the present invention, the method of bending the flat sheet glass at a predetermined angle along the cut line is performed by an appropriately designed sheet glass holding mechanism. At this time, the bending speed, external bending force and final bending angle are precisely controlled through the holding mechanism. Thereby, the occurrence of cracks in the bent portion is prevented, and a predetermined cross-sectional shape and thickness of the bent portion can be obtained. As the plate glass holding mechanism,
For example, there is a device in which a plate glass is sandwiched by a plate attached to an arm, and the plate glass is bent at a predetermined angle by moving the arm with power. Thereby, the inner angle between two adjacent planes is preferably set to 60 to 160 degrees. The bending operation can be completed in a very short time, and usually 1 to 5 minutes is preferable.

When bending the glass sheet, it is preferable to radiantly heat the glass sheet near the cut line. The radiant heating is preferably performed using a sheath heater or a halogen lamp. For example, a rod-shaped sheathed heater having a diameter of 15 mm is placed parallel to the cut line at a position approximately 40 mm away from the cut line in a direction perpendicular to the surface of the glass sheet and heated.

The sheet glass used in the present invention is used for building or general industry. The glass sheet may be manufactured by a known method.However, since it is necessary that the flat portion of the glass sheet molded body manufactured by the method of the present invention has no distortion, a float glass sheet formed on metal without melting is used. It is preferred to use. The thickness, shape and dimensions of the sheet glass used are determined according to the purpose,
There is no particular limitation. In the method of the present invention, since the bent portion is formed at a predetermined angle by providing the groove-shaped cut line, the radius of curvature of the outer periphery of the curved surface in the direction perpendicular to the bent portion can be extremely reduced even for glass having a large thickness. The composition thereof is also not particularly limited, and plate glass having various softening points such as commonly used soda-lime glass, borosilicate glass, and high-strength crystallized glass can be used. As for the type of the sheet glass, ordinary sheet glass, netted sheet glass, polished sheet glass, shaped sheet glass and the like are used. Further, the above-mentioned plate glass may be subjected to various surface treatments such as heat ray reflection coating, non-reflection coating, specific pattern printing, and surface etching.

It is preferable that many of the components of the conductive material in the score line are gradually burned, volatilized or diffused into the glass during heating before fusion, and disappear. Therefore, almost no resin remains after the completion of molding. In this respect, a carbon-based conductive paint is preferred. The lines drawn in addition to the above can be removed during heating or after heat molding. The linear conductive material drawn on the glass surface does not adversely affect fusion even if it remains on the glass surface. The remaining conductive material can be removed by bubbling oxygen completely after the heat molding, or by a suitable mechanical or chemical method such as polishing after cooling the glass. In addition, from the viewpoint of design, when it is desired to leave a streak of a conductive material in the completed sheet glass molded body, use a conductive material having a predetermined composition such that a desired color tone appears in advance. You can draw streaks.

The glass after heat molding is post-treated in the same manner as in the prior art. For example, the glass can be gradually cooled or quenched to be gradually cooled, reinforced, or double reinforced. Also heat ray reflective coat,
Various surface treatments such as anti-reflection coating, specific pattern printing, and surface etching can be performed.

A single sheet glass formed from a plurality of flat portions having at least one straight bent portion manufactured by the method of the present invention has a curvature of an outer periphery of a curved surface in a direction perpendicular to the bent portion. The radius is 4 times or less, and preferably 2 times or less, the thickness of the sheet glass in the plane portion. When the radius of curvature exceeds four times the thickness of the glass sheet, the distortion of the see-through object in the bent portion is not preferable, and in a remarkable case, the see-through object appears to expand. Also, there may be a transition region between the bent portion and the flat portion that is slightly deformed and loses flatness,
The width of the transition region is preferably at most 6 times the thickness of the glass sheet, particularly preferably at most 2 times. If the width is more than twice, the see-through object is distorted in the flat portion near the bent portion, which is not preferable. The sheet glass molded body,
The flat glass surface of the flat portion is substantially flat. For example, in the case of a molded sheet glass using a float sheet glass, the flatness of the float sheet glass before bending is maintained as it is.

The above-mentioned sheet glass molded body has at least one corner portion, and examples thereof include various molded bodies as shown in FIG.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

[0033]

Example 1 A square float glass sheet (soda-lime glass, softening point 740) having a length and width of 1,000 mm and a thickness of 5 mm
In the center of ℃, annealing point 540 ℃), a cut line with a triangular cross section (the angle to the opening is a right angle, depth 2 mm) is created using a V-cut machine for sheet glass (manufactured by Suzuki Shokai Co., Ltd.) did. Next, a silver-based conductive material (trademark: H9100, manufactured by Hokuriku Paint Co., Ltd.) is placed at the position shown in FIG.
Was used to draw two lines with a width of 3 mm in parallel from both the left and right ends of the cut line at a thickness of 50 μm using a screen printing method on a sheet glass surface. Next, the plate glass is gripped by a plate glass holding mechanism that sandwiches the plate glass with a plate attached to the arm, and the plate glass is held at 470 ° C. in an electric furnace.
Was heated uniformly. Subsequently, a solid electrode was brought into contact with the end of the wire, and a current of 50 Hz and 38 V AC was applied to the wire for 2 minutes to heat the sheet glass of the wire to 800 ° C. Subsequently, the sheet glass was bent by the sheet glass holding mechanism such that the two flat portions were perpendicular to each other in about one minute, with the cut line being inside. Next, the sheet glass was gradually cooled. The bent portion of the manufactured sheet glass molded article was completely fused without any gap.

[0034]

Example 2 A cut line having the same shape was formed in a float glass sheet having the same dimensions as in Example 1. Next, FIG.
2 mm from the left and right ends of the cut line
, Two lines were drawn in parallel, and one line with a width of 2 mm was drawn on the bent portion of the glass surface opposite to the cut line portion. The above three total filaments are made of a carbon-based conductive material (trademark Bunny Height F-525W-1, manufactured by Nippon Graphite Shoji Co., Ltd.)
Was drawn on a sheet glass surface to a thickness of 20 μm using a screen printing method. Next, the sheet glass was gripped by the sheet glass holding mechanism in the same manner as in Example 1, and 470 ° C.
Was heated uniformly. Subsequently, a solid electrode was brought into contact with the end of the wire, and a current of 50 Hz and 38 V AC was applied to the wire for 1 minute to heat the sheet glass of the wire to 800 ° C. Subsequently, the plate glass was bent by the plate glass holding mechanism such that the two flat portions became perpendicular to each other in about 30 seconds, with the cut line inward. Next, the sheet glass was gradually cooled. The bent portion of the manufactured sheet glass molded article was completely fused without any gap.

[0035]

According to the present invention, it is possible to heat the sheet glass of the striated portion to a temperature higher than the softening point in a very short time, and to completely fuse the groove. As a result, a sheet glass molded body having excellent mechanical strength at the bent portion is obtained.

[0036]

[Brief description of the drawings]

FIG. 1 is an enlarged cross-sectional view showing the vicinity of a cut line portion in a sheet glass according to the present invention.

FIG. 2 is an example of a linear pattern having a non-uniform or intermittent width along a longitudinal direction used in the method of the present invention.

FIG. 3 is an example of a molded sheet glass produced by the method of the present invention.

FIG. 4 is an example of a cross-sectional view in a bending direction of a bent sheet glass manufactured by a conventional method.

[0037]

[Explanation of symbols]

d: thickness of sheet glass A ₁ , A ₂ : plane portion AB ₁ , AB ₂ : transition region between plane portion A ₁ , A ₂ and bent portion B ₁ B ₁ : bent portion

────────────────────────────────────────────────── (5) References JP-A-58-130125 (JP, A) JP-A-54-25918 (JP, A) US Patent 5,589,248 (US, A) US Patent 5,702,496 (US, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) C03B 23/00-23/26 C03C 17/00-17/44

Claims (7)

(57) [Claims] 1. A plurality of flat portions having at least one linearly bent portion by providing a groove-shaped score line on a sheet glass and bending the sheet glass along the score line with the score line inside. In the method of making a sheet glass molded body constituted by the above, by drawing a line using a conductive material in the above-mentioned cut line or in the vicinity thereof, by supplying power to the line section, the glass of the line section of the sheet glass A method for producing a sheet glass molded body, wherein the glass at the cut line portion is fused by heating to a temperature equal to or higher than the softening point. 2. The method according to claim 1, wherein the location where the line is drawn is a bend in the cut line, on the glass surface adjacent to the cut line, and / or on the glass surface opposite to the cut line. 3. The wire is non-uniform or discontinuous in width or thickness along its length, and power is supplied to the wire to cause an arc discharge along the wire, The glass of the striated part is heated, or characterized by the above-mentioned.
2. The method according to 2 . 4. The width of a place where the width of the filament is wide is 0.5 to 5 m.
4. The method according to claim 3, wherein the width of the narrow part is 1 mm or less. 5. The method according to claim 3, wherein the filaments are intermittent at intervals of 0.1 to 2 mm. 6. The filament has a length of 0.3 to 10 m along the longitudinal direction.
A method according to any one of claims 3 to 5, comprising a repeating pattern of length m. 7. The method according to claim 1, wherein the whole sheet glass is heated substantially uniformly at a temperature lower than the annealing point of the sheet glass, and then the linear portion is heated as described above. .