JPH10218630A - Mirror finished surface forming mold - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a forming mold, excellent in durability and capable of molding many mirror surface bodies by forming a recessed part for supporting a lateral edge of a flat platy glass plate to be curved and formed on the top surface of a mold body made of diatomaceous earth and installing reinforcing materials better in impact resistance than that of the mold body located in each corner of the recessed part therein so as to nearly align with the recessed part surface. SOLUTION: A recessed part 7 of a nearly planar square shape is formed on a top surface plate 5 of a mold body 2 of a mirror surface forming mold 1 made of diatomaceous earth and a cavity 11 coincident with a protruding curved surface of a mirror surface body, curved and formed in the central part of the recessed part 7. Many through-holes 17 having an axial line in the vertical directions are formed on the top surface plate 5 of the cavity 11 so as to communicate with a hollow part formed in the lower part of the mold body 2. Mounting holes 19 corresponding to respective corners of the recessed part 7 are formed in the top surface plate 5. Reinforcing materials 21 better in impact resistance than that of the mold body 2 are inserted and fitted into the mounting holes 19.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a flat glass plate having a convex curved surface having a required curvature (in the present invention, a curved surface which is entirely curved at a constant curvature and partially different in curvature from the curved surface in the present invention). The present invention also relates to a mirror-surface forming die formed on a curved surface and a curved surface having a constant curvature, including a case where a gradually changing curved surface having a gradually changing curvature is provided.

[0002]

For example, in a vehicle mirror (including an inner mirror and an outer mirror) and the like, a glass plate is formed on a convex curved surface having a predetermined curvature in order to enlarge a rear view. However, in order to form a flat glass plate into a convex curved surface, diatomaceous earth having a curved concave portion (cavity) having a required curvature on the upper surface or a product name: Super Bender (manufactured by Isolite Industries) or a product name: After setting a flat glass plate in a mold formed of a material such as FFB setter (Nichias), the mold and the glass plate are heated to a glass softening temperature while vacuum-suctioning the glass plate in a firing furnace. The softened glass plate is formed into a mirror body having a required curved surface by matching the cavity with the vacuum along with the vacuum suction.

[0003] Of the above-mentioned molds, the one made of diatomaceous earth has a relatively low heat capacity, so that the mold itself can be heated to the glass softening temperature in a short time. However, the mold itself is extremely fragile and easily broken. When the glass sheet is curved and formed by vacuum suction, the deformation stress concentrates on each corner of the cavity, and the mold may be broken. For this reason, the number of molds that can be formed by a single mold is limited, which is an obstacle to reducing the molding cost.
In addition, since careful handling is required for loading and unloading the mold, workability is poor.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned conventional drawbacks. The object of the present invention is to form a large number of mirrors and reduce the manufacturing cost. An object of the present invention is to provide a mirror mold.

[0005]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a concave portion for supporting a side edge of a flat glass plate to be curved and formed on the upper surface of a diatomaceous earth mold, and a concave portion formed in a central portion of the concave portion. In a mirror-shaped mold provided with a cavity that matches the convex curved surface of the mirror body, a reinforcing body that is more impact-resistant than the Install each one to match.

When the flat glass sheet is set in the recess of the mold and heated to the softening temperature of the glass,
The stress of the glass plate when being bent and deformed by being pressed against the cavity is received by the reinforcing member to avoid directly acting on the mold.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings.

Embodiment 1 FIG. 1 is an overall perspective view of a mirror mold.

FIG. 2 is a vertical sectional view taken along the line II-II of FIG.

FIG. 3 is a vertical sectional view taken along the line IV-IV of FIG.

The mold body 2 of the mirror forming mold 1 is made of diatomaceous earth and has an inverted box shape having a hollow portion 3 at a lower portion, and a substantially flat square recess 7 is formed in the upper surface plate 5 at an appropriate depth. ing.
A cavity 11 is formed at the center of the recess 7 so as to coincide with the convex curved surface of the mirror body 13 that is curved and formed. The connection area 1 is located between the recess 7 and the cavity 11.
5 are provided, and the connection area 15 is gradually inclined toward the cavity 11.

A large number of through-holes 17 having an axis in the vertical direction as shown in the figure are formed in the upper surface plate 5 at 11 cavities so as to communicate with the hollow portion 3. Further, mounting holes 19 are formed in the upper surface plate 5 corresponding to the respective corners of the recess 7, and reinforcing members 21 are inserted into the mounting holes 19, respectively. Each reinforcing member 21 has heat resistance and impact resistance, for example, fused silica (SiO2: 99% or more, for example, Germany,
It is formed in the shape of a quadrangular prism or a cylinder using, for example, a fused silica manufactured by Halden Wanger or silicon nitride ceramics.

Each of the reinforcing members 21 is preferably a material close to diatomaceous earth in physical characteristics such as heat capacity and thermal expansion coefficient, but is not limited thereto. For example, when the thermal expansion coefficient is larger than that of diatomaceous earth, the amount of thermal expansion at about 700 ° C., which is the softening temperature of the flat glass plate 9, is anticipated, and the mounting holes 19 are tightly fitted with the reinforcing body 21 at that temperature. By determining the size, it is possible to prevent the mirror-finished mold 1 from being damaged due to a difference in thermal expansion between the mold 2 and the reinforcing body 21.

A notch 21a is formed in each reinforcing body 21,
And, it is formed so as to coincide with each surface of the connection region 15, and is set substantially flush with the recess 7 and the connection region 15 when the reinforcing member 21 is inserted into each of the mounting holes 19 respectively. A positioning projection and a concave portion (both not shown) are formed opposite to each other in the lower part of each reinforcing member 21 and in the mounting hole 19, and when the reinforcing member 21 is inserted into the mounting hole 19, The notch 21a of the reinforcing member 21 may be positioned so as to coincide with each surface of the recess 7 and the connection region 15 by the engagement of the protrusion and the recess.

Next, the operation of forming the mirror body 13 by the mirror surface forming die 1 formed as described above will be described.

FIG. 4 is a partial longitudinal sectional view showing a state where the mirror-surface forming die is mounted on the firing table.

FIG. 5 is a longitudinal sectional view showing a curved state of a flat glass plate.

A suction hole 33 connected to a vacuum suction device (not shown) is provided in the baking table 31 on which the mirror-surface forming die 1 is placed. It is placed so that the hollow portion 3 is located above the suction hole 33. Further, a flat glass plate 9 is set in the concave portion 7 of the mirror mold 1. At this time, each corner of the flat glass plate 9 is supported by the notch 21 a of each reinforcing body 21.

Next, in the above state, the baking table 31 is placed in a baking furnace (not shown) while vacuum-sucking the flat glass plate 9 supported in the recess 7 with vacuum suction from the through hole 17. The flat mold 1 and the flat glass plate 9 are heated to about 700 ° C., which is the softening temperature of the flat glass plate 9.

When the flat glass plate 9 is softened by the above-mentioned heating, the central portion of the flat glass plate 9 is pressed against the cavity 11 by a vacuum suction action, and the convex curved surface of the flat glass plate 9 coincides with the cavity 11. It is formed into a mirror body 13.
At this time, the central portion of the flat glass plate 9 is deformed due to the vacuum suction, and the deformation stress of the flat glass plate 9 acts on each corner of the recess 7. Since each corner of the plate 9 is supported by the reinforcing member 21, the deformation stress is prevented from directly acting on the mold body 2, thereby preventing loss and the like.

Next, the mirror-surface forming die 1 is carried out of the firing furnace, and the flat glass plate 9 is gradually cooled so as to have the original hardness. Then, the mirror body 13 is cut off, and the molding operation is completed. The surface of the thus formed mirror body 13 is polished to finish the product. Further, when setting the flat glass plate 9 in the concave portion 7 of the mirror forming die 1, when taking out the curved flat glass plate 9 from the concave portion 7, or when setting the concave glass 7 When the flat glass plate 9 set therein is vacuum-sucked, an excessive force acts on each corner of the recess 7, but this force is received by the reinforcement 21 and acts on the mold 2. To avoid loss.

As described above, in the present embodiment, the force generated due to the curvature of the flat glass plate 9 is received by the reinforcing members 21 provided at the corners of the recess 7 and acts on the mold 2. By avoiding this, breakage of the mirror mold 1 can be effectively prevented. For this reason, a large number of flat glass plates 9 can be curved-formed by one mirror-surface forming die 1, and the molding cost can be reduced.

Embodiment 2 FIG. 6 is an exploded perspective view of a mirror mold.

FIG. 7 is a longitudinal sectional view of the mirror forming mold taken along the line VII-VII in FIG.

The mold body 42 of the mirror forming mold 41 is made of diatomaceous earth similarly to the mirror forming mold 1 of the first embodiment.
A cavity 47 is formed at the center of the recess 5 and the recess 45, respectively.

A mounting groove 51 is formed in the entire circumference of the recess 45 and in a connection area 49 provided between the recess 45 and the cavity 47, and the mounting groove 51 substantially coincides with the recess 45. A rectangular frame-shaped reinforcing member 53 is inserted. The reinforcing member 53 is made of the same fused silica or silicon nitride ceramic as the reinforcing member 21 of the first embodiment,
A support portion 53a is provided on the upper inner side surface of the reinforcing body 53 in the connection region 4.
9, and the supporting portion 53a supports the peripheral edge of the flat glass plate 9.

The mirror forming mold 41 formed as described above supports each side edge of the flat glass plate 9 to be curved by the support portion 53 a of the reinforcing member 53. For this reason,
The deformation stress of the flat glass plate 9 being deformed in a curved shape due to the vacuum suction is received by the reinforcing member 53 having higher impact resistance than the mirror-surface forming die 1, and the direct acting on the die 42 is avoided. Loss can be prevented.

In the first and second embodiments, the mirror mold 1 is used.
Although one cavity 11 (47) is provided in (41), a plurality of cavities 11 (47) are provided in a single mirror-surface forming mold 1 (41) and a large number of flat glass plates 9 are simultaneously bent. It may be molded.

[0029]

According to the present invention, the number of moldable sheets can be increased and the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is an overall perspective view of a mirror mold.

FIG. 2 is a vertical sectional view taken along line II-II of FIG.

FIG. 3 is a vertical sectional view taken along the line IV-IV of FIG. 1;

FIG. 4 is a partial longitudinal sectional view showing a state where a mirror-surface forming die is mounted on a firing table.

FIG. 5 is a longitudinal cross-sectional view showing a curved state of a flat glass plate.

FIG. 6 is an exploded perspective view of a mirror mold.

FIG. 7 is a longitudinal sectional view of the mirror forming mold taken along a line VII-VII in FIG. 6;

[Description of Signs] 1 Mirror surface molding die, 2 molds, 7 recesses, 9 flat glass plates, 11 cavities, 13 mirrors, 19 mounting holes, 21 reinforcement

Claims (5)

[Claims] 1. A concave portion for supporting a side edge of a flat glass plate to be curved and formed on the upper surface of a diatomaceous earth mold, and a convex curved surface of a mirror formed at a central portion of the concave portion. A mirror mold having a cavity, wherein a reinforcing member having better impact resistance than the mold is attached to a mold located at each corner of the recess so as to substantially coincide with the recess surface. 2. A concave portion for supporting a side edge of a flat glass plate to be curved and formed on the upper surface of a diatomaceous earth mold, and a convex curved surface of a mirror formed at the center of the concave portion. A mirror-surface molding die provided with cavities, wherein a reinforcing member having more excellent impact resistance than that of the molding is attached to a die positioned at the periphery of the concave so as to substantially coincide with the concave surface. 3. A mirror mold according to claim 1, wherein the reinforcing member is made of fused silica. 4. A mirror mold according to claim 1, wherein the reinforcing member is made of ceramic. 5. The mirror forming mold according to claim 1, wherein at least the cavity at the cavity portion is provided with a large number of through holes connected to a vacuum suction device.