JPH0329296Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a mold for molding glass, and particularly to a mold for glass molding suitable for molding a glass product whose peripheral portion has a three-dimensional shape.

[Technical background of the invention and its problems]

In the past, most of the glass press-molded products had a two-dimensional flat peripheral edge.For example, the front lens of an automobile headlamp changed from a round shape to a square shape.
Although the shape has changed from square to large rectangle, the shape of the periphery has always been a two-dimensional plane. Recently, however, there has been a demand for rectangular lenses with complex shapes that are fashionable to match the body lines of automobiles, and there has been a strong demand for the establishment of a manufacturing technology for press-molded products having three-dimensional peripheral edges.

However, when molding a rectangular lens with a complex shape using conventional technology, a molten glass gob (hereinafter referred to as a glass gob) is press-molded using only the lower die (hereinafter referred to as the bottom) and the upper die (hereinafter referred to as the plunger) in the mold combination. In order to compress without an annular presser mold (hereinafter referred to as a ring), a method was used in which a flowing glass cob was formed so as to protrude from the periphery, and after cooling, unnecessary parts were cut off. This method is very time-consuming and has a low manufacturing efficiency and low yield rate.

Further, when the conventional method is used to press-mold the complex-shaped rectangular lens by combining a mold using a ring, the following problems occur.

(1) The molds for molding large rectangular lenses with complex shapes are heavy and complicated, making it difficult to center each mold. In addition, due to the increased pressure during press molding, the fixing tool that centered the ring, bottom, and plunger was likely to loosen, resulting in frequent protrusion, chipping, and cracks at the periphery of the glass molded product.

(2) Also, due to the three-dimensional shape of the periphery, the pressurizing force increases during press molding and the temperature of the glass gob increases, causing damage to the part of the mold that forms the periphery to cover the flow of glass within the mold. The number of cracks increased significantly, and cracks from the periphery occurred frequently due to partial damage to the mold.

(3) Furthermore, it was difficult to set standards for adjusting the spacing (hereinafter referred to as clearance) between the plunger and the bottom and ring, making it difficult to obtain products with uniform wall thickness.

[Purpose of invention]

The present invention was developed in view of the above circumstances, and it is possible to manufacture complex-shaped glass products with three-dimensional peripheral edges without performing secondary processing or other means, while maintaining high dimensional accuracy on an industrial scale. The objective is to provide a glass molding mold that can be mass-produced.

[Summary of the idea]

In order to achieve the above object, the present invention provides a plurality of keyways on the outer surface of the bottom, and a key that engages with the keyways is provided on the outer surface of the ring, thereby facilitating center adjustment of each mold combination. After the center is fixed, a cobalt-based hard alloy is welded to the sliding contact parts of the key and keyway to prevent wear and tear. Furthermore, when press molding a glass gob, a cobalt-based hard alloy is welded to the sliding contact portions of the plunger, bottom, and ring that contact the peripheral edge of the glass product to prevent wear and tear on the mold as much as possible.

[Example of idea]

Next, the present invention will be explained in detail based on examples and drawings. FIG. 1 is a perspective view of a conventional rectangular headlamp lens, and FIGS. 2 and 3 are perspective views of a complex-shaped rectangular lens. In the figure, a prism for light distribution of a headlight is engraved in part 1, and a prism for a side marker lamp or a turn signal lamp is engraved in part 2. The part 3 is a side vertical wall that corresponds to the connection between the headlight and the vehicle body, and is usually molded. Also, the part 4 is connected to the bonnet as part of the vehicle body.

Next, the molding die of the present invention will be explained. 4 and 5 are a plan view and a front view showing the assembly of the plunger, bottom and ring according to the present invention. In the figure, 11 is a press-molded glass product, 1
2 is a plunger, 13 is a ring, and 14 is a bottom.

Plunger 12 is attached to adapter 16,
It is connected to a piston shaft of a press machine (not shown). The ring 13 is attached to a spacer 17 and, like the plunger, is attached to a press machine. A plurality of bottoms 14 are mounted on a rotary table of a press machine (not shown).

The present inventors manufactured several types of prototype molds and conducted various experiments, and as a result, they found that the following mold is optimal for molding complex-shaped glass products.

That is, in the assembly structure of the plunger 12, ring 13, and bottom 14, three or more keyways 19 are provided on the outer surface of the bottom 14, and the same number of keys 15 that engage with the keyways are provided on the outer surface of the ring 13 on the mounting screws 18. It is installed accordingly.

In addition, one or both of the keyway 19 and the sliding contact portion 20 of the key 15 are made of 30 to 65% Co, 10 to 30% Cr, and 5 to 5% W2, commonly known as Stellite.
It is characterized by welding a cobalt-based hard alloy whose main component is % to prevent wear and tear on the key and keyway parts. Figure 6 shows A of the peripheral edge of the glass product in Figure 5 and the part of the mold that comes into contact with the peripheral edge.
It is an enlarged view of the part.

The above-mentioned cobalt-based hard alloy is welded over the entire circumference of the portions of the plunger 12, ring 13, and bottom 14 corresponding to g, e, and f, respectively, which contact the peripheral edge of the glass product 11 in the molded state. .

The mold formed with the above configuration has a keyway on the bottom and a key on the ring to facilitate center adjustment, and also to prevent loosening of the bottom and ring fixings due to increased pressure during press molding. Do not cause Also, the reason why the plunger is left free without a key or keyway is that it is especially useful when molding complex-shaped glass products.
We have confirmed through various experiments that it is better to give the plunger a certain degree of freedom in view of the fluidity of the glass during pressing and the operability of the pressing mechanism. In this case, a method of fixing all the molds in one set by providing a key on the plunger and a keyway on the ring and bottom is not appropriate.

Further, the number of keys and key ways is suitably 3 to 5, the width of the keys is preferably 15 to 50 mm, and the length can be as long or short as long as it fits into the key way. It is preferable to taper the tip of the key at a slight angle inward to make it easier to enter the keyway.

Furthermore, it is appropriate that the cobalt-based hard alloy welded to the key or keyway be welded to a depth of 1.0 to 2.0 mm, and to have a width that is preferably welded to the entire sliding surface.

It is desirable that the cobalt-based hard alloy welded all around the plunger, bottom, and ring described above should be welded to a depth of 1.5 to 5.0 mm on the entire surface that contacts the peripheral edge.

The present invention is not limited to the rectangular lens mold having the three-dimensional shape of the above embodiment,
Of course, it can also be applied to molds for complex-shaped glass products such as glass tableware and glass parts for electron tubes.

[Effect of idea]

As explained above, according to the mold according to the present invention, center adjustment is easy, there is no bulging due to center deviation even when pressure increases during press molding, and the mold is molded by welding cobalt-based hard alloy. Damage was significantly reduced. Furthermore, it has now become possible to mass produce glass products with three-dimensional peripheral edges, which was previously considered difficult to directly mold.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an example of a conventional square headlight lens, FIGS. 2 and 3 are perspective views showing an example of a complex-shaped rectangular lens, and FIG. 4 is a mold according to the present invention. FIG. 5 is a longitudinal sectional view thereof, and FIG. 6 is an enlarged view of section A in FIG. 5. 12...Plunger, 13...Ring, 14...
...bottom, 15...key, 19...keyway.

Claims (1)

[Claims for Utility Model Registration] (1) A mold for forming a glass product whose peripheral edge has a three-dimensional shape, including a plurality of keyways on the outer surface of the open end of the lower mold, and the open end of the lower mold. The same number of keys that engage with the keyway are provided on the outer surface of the annular presser mold that comes into contact with the keyway, and a cobalt-based hard alloy is provided on the surface layer of the sliding portion of either or both of the engaging keys or the keyway. A mold for complex-shaped glass molding, characterized by welding. (2) Utility model registration claim 1, characterized in that a cobalt-based hard alloy is welded to the sliding contact portions of the upper mold, lower mold, and annular presser mold that contact the peripheral edge of the glass molded product. A mold for molding complex-shaped glass.