JPH0543061Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Field of Application) The present invention relates to a device for locally sharply bending foam glass sheets, and is particularly suitable for manufacturing foam glass sheets that are applied to corners of buildings and the like.

(Prior art and its problems) There are many known examples of bending ordinary plate glass. For example, Japanese Patent Publication No. 34-10477 consists of a mold for the central part and molds for both wing parts that are mounted on the central part, and a glass plate is placed on the mold and the molds for both wing parts are brought to the closed position in a heating furnace. There are few similar disclosures, such as Japanese Patent Publication No. 31-2337, which discloses applying local heating to the part where the glass plate should be bent to a large curvature. Zuar.

However, foam glass plates are significantly different from regular glass plates in that they are thicker and have difficulty transmitting heat. Even if the surface of the bent part is heated, the heat does not reach the center, making it difficult to bend or bending the bent part. Excessive heating may change the texture of the area, ie, the bubble diameter, color tone, etc.

In addition, the thickness of the bent part of the foam glass plate becomes abnormally thick, and when it is flat, the outside and inside surfaces of the foam glass plate,
Even if the angle formed with the end face is a right angle, there is a problem in that it changes to an oblique angle after bending.

When a normal glass plate is heated to near its softening point, it becomes highly plastic and bends extremely easily. On the other hand, there are almost no disclosed examples of bending special glasses that are difficult to bend, such as crystallized glass or foam glass. Japanese Patent Application Laid-open No. 50-46722 discloses that a crystallized glass containing β-wollastonite as a main ingredient is heat-plasticized and bent under its own weight to follow a curved molding surface. This method can be applied to objects with a small curvature, but if the curvature is large, it becomes difficult to curve the object to follow the mold surface.

Furthermore, JP-A No. 62-241834 discloses that a preformed foam glass plate is bent and formed, placed on a mold with a similar curved surface, and heated and foamed. This may cause deformation or increase dimensional errors, making it difficult to obtain a product with the desired shape and dimensions.

On the other hand, when bending a foam glass plate once finished,
It has excellent insulation properties and is only about 10 mm thick.
The length is nearly 100 mm, which makes it difficult to equalize the heat and is easily damaged by sudden or local heating or by external force. In particular, when trying to bend sharply using a bending mold as disclosed in JP-A No. 50-46722, it is necessary to heat the glass significantly beyond its softening point to increase its plasticity. The remaining unfoamed blowing agent, such as calcium carbonate, foams to increase the bubble diameter and sometimes destroys the bubble wall due to rapid foaming. In addition, the bubble diameter locally increases on the outer periphery of the curved surface, impairing uniformity. On the other hand, if the heating temperature is kept close to the softening point, the plasticity will be low and the material will not be able to bend sufficiently along the bending pattern.

The present invention eliminates these disadvantages and provides a device that can easily bend a foam glass plate.

(Means for Solving the Problems) The present invention consists of a pair of flat foam glass plates that are arranged side by side with a gap between each other and are hinged at opposite front and rear ends so as to be rotatable. In a self-weight bending device for a foam glass plate formed from a heating band provided directly under the flat gap, an abutting member for pressing the foam glass plate vertically installed above the gap; The present invention is characterized by a device for bending a foam glass plate, which is characterized in that it includes a flat mold and a flexible thin plate member laid across a gap.

(Example) The present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a perspective view of the present invention, and in the figure, 1 and 1 are a pair of SUS flat molds on which foam glass plates 2 are placed.
They are arranged side by side with a gap 3 between them, and their opposing front and rear ends 4 and 5 are rotatably hinged. A heating band 6 is provided directly below the gap 3. The figure shows a pair of front and rear metal wires 7 suspended from a flat model as an example.
(The rear end portion is omitted) The resistance heating winding 6 placed on the refractory 8 placed horizontally is heated by electrical current through the lead wire 6'. Of course, the heating band may be provided separately.

On the flat molds 1 and 1, a thin metal plate, specifically a thin metal plate member 9 that is highly flexible and thermally conductive, for example, a metal plate of SUS or the like with a thickness on the order of 10 ^-2 to 1 mm, fills the gap 3. The foam glass board 2 is laid across the board.
be interposed between.

On the other hand, above the gap 3, a contact member 11 made of metal or ceramics is vertically provided so as to be movable up and down so as to come into contact with the upper surface of the bent portion 10 of the foam glass plate 3.

FIG. 2 is a schematic front cross-sectional view of the inside of a resistance heating furnace incorporating the device of the present invention.
12 is suspended by metal wires 13, 13, and the upper ends of the metal wires 13, 13 are supported by the upper frame portion 16 of the support frame 15.

Incidentally, weight balances 17, 17 may be appropriately attached to both ends of the flat molds 1, 1 in advance.

On the other hand, the abutment member 11 is also supported by a slit hole 14 provided in the upper frame portion 16 of the support frame 15 so as to be movable up and down, and its tip portion is brought into contact with the foam glass plate 2 placed on the flat molds 1,1.

In this state, the heating furnace is gradually heated, and when the glass reaches a temperature equivalent to its strain point, 500°C for soda-lime glass, electricity is gradually applied to the heating band 6, and the bending portion 10 of the foam glass plate 2 is Let it heat up. In this case, since the thin metal plate 9 (see Fig. 1) is laid in advance, the lower surface of the planned bending section 10 is not directly exposed to the heat source 6, so overheating can be avoided and the temperature of the section can be equalized. .

Along with this, the hinge parts 4 and 5 of the flat molds 1 and 1 (first
(see figure), the bent portion 10 of the foam glass plate 2 also bends accordingly, and the contact member 11 also presses the upper surface of the bent portion 10. Next, when the temperature of the entire foam glass plate 2 exceeds 650° C. and the bent portion 10 reaches an appropriate temperature of about 720° C. or above, the temperature increase is stopped and the temperature is maintained. At this point, the flat molds 1, 1 form a predetermined angle, but on the other hand, the foam glass plate 2 still has poor plasticity and is therefore insufficiently bent. Further, the abutting member 11 presses and assists the bending, whereby a desired bent shape can be obtained.

As shown in FIG. 3, the obtained bent foam glass plate 2 can prevent the thickness of the bent portion of the foam glass plate shown by arrow t from becoming abnormally thick due to the pressing action of the contact member 11, and The pressed area 10' is dense and has a high specific gravity, and the brittleness of this area, which is prone to chipping and cracking, is improved. Furthermore, if there is no contact member 11,
Angles α and α between the outer surface and the end surface of the foam glass plate 10
However, due to the pressing action of the contact member 11, the foam glass plate 10 The inner surfaces of are pulled in the direction of arrows 18, 18 to maintain said α, α, α', α' at right angles.

In addition, as described above, by laying the metal thin plate 9, the bent local part of the lower surface (outer surface) of the foam glass plate 10 is not directly exposed to the heat of the heating band 6, so that the texture, that is, the size and color of the bubbles can be changed. The appearance texture does not change due to the change, and the occurrence of cracks and loosening is also suppressed.

Although the above description has been made by simply bending a foam glass plate, the foam glass plate may have a dense glass layer previously provided on its outer surface. During the original lamination and molding, the dense glass layer is in contact with the mold surface, so it is in a slightly hazy state like a plate glass, giving it an attractive appearance.

If this is bent without laying the thin metal plate 9 during bending, the lower surface of the bent portion 10 may be overheated and locally loosened, or the surface may become a fire-shaped mirror surface and the surrounding haze may form. However, according to the present invention, there is no risk of local overheating due to the intervention and contact of the thin metal plate 9, and the haze-like texture is maintained, making it possible to perform the desired bending. It is.

(Effects of the invention) According to the invention, the pressing action of the contact member prevents the thickness of the bent portion of the foam glass plate from becoming abnormally thick, and this portion is pressed and has a high specific gravity, resulting in chipping and cracking. The brittleness of this portion is improved, and the angle between the outer surface of the foam glass plate and the end surface and the angle between the inner surface of the foam glass plate and the end surface can be maintained at right angles. In addition, thin metal plates can prevent changes in texture due to local overheating, and can suppress the occurrence of cracks and loosening. As a result, it is possible to easily bend a foam glass plate using a simple device, which has been considered difficult in the past, and the resulting product can be effectively applied to corners of buildings, etc.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of the present invention, FIG. 2 is a schematic front sectional view of the inside of a heating furnace according to the present invention, and FIG. 3 is a perspective view of a foam glass plate manufactured based on the present invention. DESCRIPTION OF SYMBOLS 1, 1... Flat type, 6... Heating band body, 9... Metal thin plate, 11... Contact member.

Claims (1)

[Scope of utility model registration request] A pair of flat molds for placing foam glass plates are arranged side by side with an interval between each other, and the front and rear ends facing each other are hinged so as to be freely rotatable. In a self-weight bending device for a foam glass plate formed from a tropical body, an abutment member for pressing the foam glass plate is installed vertically above the gap, and a flexible member is installed across the gap on the pair of flat molds. 1. A device for bending a foam glass plate, comprising: a thin plate member.