JP2598475B2 - Sheet glass bending machine - Google Patents

Description

Description: BACKGROUND OF THE INVENTION The present invention relates to an apparatus for forming, for example, bent glass constituting laminated glass or bending and forming sheet glass for reinforcement.

(Prior Art) In order to form a bent glass constituting a laminated glass, two sheet glasses are conventionally stacked and bent by their own weight. However, recent windshields for automobiles may be required to have a deeply bent shape or a complicated shape.
It is becoming difficult to form a laminated glass having such a shape by the self-weight method. Therefore, apparatuses disclosed in JP-A-56-120524, JP-A-57-140325 and JP-A-62-283834 are known.

The apparatuses disclosed in JP-A-56-120524 and JP-A-57-140325 load the lower mold from the inlet of the heating furnace with the plate glass placed on the lower mold, and set the inside of the heating furnace near the outlet. In the apparatus disclosed in Japanese Patent Application Laid-Open No. 62-283834, high pressure is applied when the glass sheet is conveyed below the upper mold in a heating furnace. The sheet glass is pressed against the lower surface of the upper mold by a hot air flow to bend and formed. After the forming, the pressure of the hot air flow is reduced and the plate glass is adsorbed by the upper mold.

(Problems to be Solved by the Invention) Among the above-mentioned prior arts, in the apparatuses disclosed in JP-A-56-120524 and JP-A-57-140325, the sheet glass is bent halfway by its own weight method. For example, the sheet glass is bent down to the bottom of the pot, making it difficult to correct by a subsequent press. In the apparatus disclosed in Japanese Patent Application Laid-Open No. 62-283834, since the sheet is bent by air pressure, it is deeply bent or complicated. It becomes difficult to bend into a shape.

(Means for Solving the Problems) In order to solve the above problems, the present invention provides a downstream end of a heating furnace as a forming zone, a transfer zone immediately before the forming zone, and a slow cooling zone downstream of the forming zone. The ring mold circulated through each of these zones.

(Operation) The sheet glass conveyed in the heating furnace in a horizontal state is placed on the ring mold in the transfer zone, and is pressed as it is with the upper mold, and the formed sheet glass is placed on the ring mold. The glass is taken out of the ring mold, and the ring mold enters the transfer zone again.

(Example) Hereinafter, an example of the present invention will be described with reference to the accompanying drawings.

1 is an overall plan view of a bending apparatus according to the present invention, FIG. 2 is a cross-sectional view showing the inside of the bending apparatus, FIG. 3 is a plan view of a transfer zone, and FIG. 4 is a cross-sectional view of a ring mold. , Fifth
The figure is a front view of the loading jig.

The bending apparatus is provided with a forming zone at the downstream end of the heating furnace 1, a transfer zone 3 is provided immediately before the forming zone, and an annealing furnace for gradually cooling the two bent-formed laminated glass sheets from the forming zone 2. 4 is taken out of the heating furnace 1, a sheet glass pick-up station 5 is provided at a downstream end of the lehr 4, and the pick-up station 5 and the transfer zone 3 are provided.
Are connected by a return passage 6, and a part of the return passage 6 immediately before entering the transfer zone 3 is a preheating chamber 7.

In addition, a primary cooling section 8 and a secondary cooling section 9 used for producing rapidly cooled tempered bent glass separately from the annealing furnace 4 are branched from the forming zone 2.

Next, the internal structure of the molding apparatus will be described.
2, a roller 10 for transporting the sheet glass G in a horizontal state is disposed therein. A wall 11 forming a transfer zone, a forming zone 2, an annealing furnace 4 and a return passage 6 has a third member.
As shown in the figure, a shaft 12 is inserted from the outside, a roller 13 is attached to the inner end of the shaft 12, and the shaft 12 is rotated so that the ring mold 14 placed on the roller 13 is transferred to the transfer zone 3. After that, it is transferred again to the transfer zone 3 through the forming zone, the annealing furnace 4, the return passage 6, and the preheating chamber 7. Here, the ring mold 14 heated to a predetermined temperature in the preliminary heating chamber 7 is used.
Is mounted on the roller 13 in the transfer zone 3 using a carry-in jig 15 as shown in FIG. The loading jig 15 has four claws 16. The claws 16 use the outer frame 17 of the ring mold 14.
Is supported and lifted from below, and the ring mold 14 is placed on the roller 13.

The ring mold 14 is provided with an outer ring 18 and an inner ring 19 inside the outer frame 17 as shown in FIG. 3 and FIG. 4 which is a cross-sectional view taken along line AA of FIG. While placing the sheet glass G, the portion 19a for receiving the corner portion of the sheet glass G is made wider and the portion 19b for receiving the side portion is made narrower,
Further, the plate glass is accurately positioned by the pressing piece 21 advanced and retracted by the cylinder unit 20.

Further, among the transport rollers 10 for transporting the plate glass G in a horizontal state, three transport rollers 10a disposed in the transfer zone 3 are sized to fit in the inner ring 19, and are capable of moving up and down. I have.

Further, an upper die 22 and a lower die 23 which can be raised and lowered respectively are disposed in the molding zone 2. Since the upper mold 22 and the lower mold 23 press-mold the sheet glass G in the heating furnace 1,
It is preferable to use one having a hardness (Mohs hardness of 2 to 5) which can be used continuously at 0 to 700 ° C. and can be NC-processed by a carbide cutting blade.

Specifically, alumina cement with Mohs hardness of 2-3 (Al
₂ O ₃ : 40%, SiO ₂ : 25%, CaO: 35%), calcium silicate with a Mohs' hardness of 3 to 4 and silica are melt-cooled, pulverized, and then sintered (400 to 800 ° C). The resulting specific gravity is 1.0
A fused silica (SiO ₂ : 99% or more) having a Mohs hardness of 3 to 5 at 1.9 is considered.

And, on the molding surfaces of the upper mold 22 and the lower mold 23, silica fibers,
A woven fabric or felt made of glass fiber, carbon fiber, or the like is adhered to prevent the glass sheet G from adhering to the molding surface or causing distortion.

FIGS. 2 (A) to 2 (D) illustrate the case where the sheet glass G for laminated glass is bent and formed by using the forming apparatus having the above configuration.

First, as shown in FIG. 2 (A), the sheet glass G, which is two sheets stacked in the heating furnace 1 by the transport roller 10, is transferred to the transfer zone 3.
Is transported onto the transport roller 10a. During this time, the glass sheet G is heated to near the softening point.

Next, as shown in FIG. 2 (B), the transport roller 10a descends, and the sheet glass G is transferred onto the inner ring 19 of the ring mold 14. And during this time the cylinder unit 20
Is operated to position the glass sheet G.

When the positioning is completed, the upper mold 22 and the lower mold 22 are supported while the plate glass G is supported by the ring mold 14 as shown in FIG. 2 (C).
The sheet glass G faces the space 23, and press-forming is performed while the two sheets of the sheet glass G are stacked between the upper mold 22 and the lower mold 23 as shown in FIG. 2 (D).

The press-formed sheet glass G is cooled in the annealing furnace 4 while being placed on the ring mold 14, and is discharged at the pick-up station 5.

On the other hand, the ring mold 14 from which the sheet glass G has been removed enters the transfer zone 3 again through the return passage 6.

Note that the above is an example of the embodiment. For example, as long as the zone is less than or equal to the extent that the shape and the residual stress of the sheet glass are determined at the time of slow cooling, a transfer roller may be used instead of the ring mold. Ring mold 14 omitting mold 23
And the upper mold 22 alone.

(Effects of the Invention) As described above, according to the present invention, when bending a sheet glass, the sheet glass is formed in a heating furnace and is conveyed in a horizontal state until immediately before being formed by a forming die provided in the heating furnace. As a result, even a product having a deep bending or a complicated shape can be bent accurately.

[Brief description of the drawings]

FIG. 1 is an overall plan view of a bending apparatus according to the present invention, and FIG.
3A to 3D are cross-sectional views for explaining the operation of the bending apparatus, FIG. 3 is a plan view of a transfer zone, FIG. 4 is a cross-sectional view taken along line AA of FIG. 3, and FIG. It is a front view of a carrying-in jig. In the drawings, 1 is a heating furnace, 2 is a forming zone, 3 is a transfer zone, 4 is an annealing furnace, 10 is a conveying roller, 14 is a ring mold, 22 and 23 are press dies, and G is a sheet glass.

Claims (2)

(57) [Claims] 1. A forming zone for bending sheet glass is provided at a downstream end of a heating furnace, a transfer zone for sheet glass is provided immediately before the forming zone, and a lehr is extended from the forming zone to outside the heating furnace. A plate glass bending apparatus, wherein a ring mold for supporting the sheet glass from below in the zone, the forming zone, and the annealing furnace is circulated. 2. The sheet glass bending apparatus according to claim 1, wherein a transfer line from the forming zone to a quenching zone is branched in addition to a transfer line to the annealing furnace.