JPH0769656A - Plunger for forming hollow glass product - Google Patents

Abstract

PURPOSE:To provide the plunger which solves problems in forming of hollow glass products occurring in a large temp. difference in the respective parts of forming surfaces and less damages members at the time of assembly. CONSTITUTION:The plunger for forming the hollow glass products is so constituted as to control the temp. distribution of the forming surfaces by internally providing the plunger with a distributing chamber 22 to which cooling fluid is supplied and a cooling cavity 23 existing around the distributing chamber 22 and circulating the cooling fluid through the cooling cavity 23 from the distributing chamber 22. A spring nozzle 30 for supplying the cooling fluid to the corner parts of the cooling cavity 23 from the distributing chamber 22 is so mounted as to project from the corner part of the distributing chamber 22.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hollow glass product, and more particularly to a plunger suitable for molding a panel for a cathode ray tube.

[0002]

2. Description of the Related Art When molding a panel for a cathode ray tube, first, a predetermined amount of molten glass mass (gob) is formed in a mold in which a ring mold (body type) 10 and a bottom mold (bottom type) 11 shown in FIG. 2 are combined. It is obtained by press-molding the panel 13 having a desired shape by lowering the plunger (arrow-shaped) 12 by feeding it.

Such a panel 13 is composed of a gently convex front plate 14, a corner portion 15 that bends sharply from the front plate 14, and a flange portion (side peripheral wall portion) 16 connected thereto. Seal edge 1 at the top
It is 7. The plunger 12 is wholly attached to the head body 18, and the molding surfaces thereof are the front molding surface 19 forming the inner surfaces of the front plate 14, the corner portion 15, and the flange portion 16 of the panel 13, and the corner molding surface 20. ,
The side peripheral molding surface 21.

The panel 13 is required to have a strict quality with respect to the curvature shape, cracks, wrinkles and the like of the inner surface thereof. When the panel 13 is molded, the temperature distribution on the molding surface of the plunger 12 is the quality. Influence.

Therefore, it is required to strictly control the temperature distribution on the molding surface of the plunger 12, and for example, as shown in FIG. 3, a distribution chamber 22 into which a cooling fluid such as cooling water or cooling air is supplied. Further, the cooling cavity 23 is provided along a portion located around the distribution chamber 22, that is, along the front molding surface 19, the corner molding surface 20, and the side peripheral molding surface 21.

In such a plunger 12,
Cooling fluid is supplied from the center of the head body 18 to the plunger 12
After being supplied to the distribution chamber 22 of the first place, the cooling cavity 23 is supplied through a nozzle 25 provided at various places in the distributor 24.
Forming surface 1 of the plunger 12 by supplying
9, 20, 21 are cooled, and then discharged from a discharge port 26 communicating with the head body 18.

Further, this plunger 12 projects into the cooling cavity 23 toward the corner molding surface 20 in order to maintain the temperature of the side peripheral molding surface 21 higher than the temperature of the front molding surface 19, and the cavity is formed. Insulating plate 28 such as gasket packing for providing a main cooling chamber 27 with a wide space
The corner forming surface 20 of the plunger 12 is sufficiently cooled by attaching the pressing tool 29 so that the temperature difference between the corner forming surface 20 and the side surface forming surface 21 does not become large.

[0008]

In spite of the above structure, the conventional plunger 12 has the side peripheral molding surface 2
1. Especially, the portion A near the seal edge 17 of the panel 13 is much colder than the portion B near the corner molding surface 20, which causes cracks in the upper inner surface of the flange portion 16 of the panel 13 and the seal edge 17. It is the cause. The occurrence of the above-mentioned overcooling cracks is more remarkable when the panel 13 is formed such that the length of the flange portion 16 of the panel 13 is short and therefore the distance between the portion A and the main cooling chamber 27 is short.

Therefore, in order to raise the temperature at the point A and prevent the above-mentioned supercooling cracks from occurring, the flow rate of the cooling water is reduced,
Attempts have been made to raise the temperature of the entire plunger 12, but in this case, the temperature at the point B becomes too high and the panel 13 is easily bonded to the temperature, and when the plunger 12 is pulled up after molding, at the time of mold release. The panel 13 adheres to the molding surface of the plunger 12 and is lifted together with the depressurizing action, and the surface deformation of the glass ridge called sock-up causes the surface of the front plate portion 14 or the corner portion 15 of the panel 13. Will be formed.

Further, it has been proposed that a copper pipe is attached so as to project from the corner of the distribution chamber, and the cooling fluid is supplied to the main cooling chamber located at the corner of the cooling cavity through the copper pipe. Such a plunger has a great effect of cooling the B portion and a temperature difference between the A portion and the A portion is small, but when assembled, the copper pipe is likely to come into contact with the cooling cavity and bend.

It is an object of the present invention to provide a plunger that solves the problem of forming a hollow glass product due to a large temperature difference between the various parts of the forming surface and has less damage to the members during assembly.

[0012]

A hollow glass product molding plunger of the present invention comprises a distribution chamber into which a cooling fluid is supplied, and a cooling cavity located around the distribution chamber. In a hollow glass product molding plunger, in which a cooling fluid is circulated through the molding chamber to control the temperature distribution on the molding surface, a spring nozzle that supplies the cooling fluid from the distribution chamber to the corner of the cooling cavity has a distribution nozzle. It is characterized in that it is attached so as to project from the corner portion of the.

The spring nozzle used in the present invention has a property of immediately returning to its original shape even when bent, and its material is to prevent rust and clogging of the nozzle. A metal such as stainless steel, which hardly causes rust, is preferable.

[0014]

According to the hollow glass product forming plunger of the present invention, the spring nozzle for supplying the cooling fluid from the distribution chamber to the corner portion of the cooling cavity is attached so as to project from the corner portion of the distribution chamber. Therefore, the effect of cooling the molding surface of the corner of the plunger is great, a large temperature difference does not occur in each part of the molding surface, and the spring nozzle immediately returns to its original shape when it comes into contact with another member and bends. , No damage when assembling the plunger.

[0015]

EXAMPLES The hollow glass product molding plunger of the present invention will be described in detail below with reference to examples.

FIG. 1 is a partial sectional view showing the molding of a cathode ray tube panel using the plunger of the present invention. still,
In the following description, the same parts as those in FIGS. 2 and 3 and the parts corresponding to those in FIG. 3 are designated by the same reference numerals in FIG. 1, and the description of these parts is omitted.

In the plunger 12 shown in FIG. 1, a stainless steel spring nozzle 30 for supplying a cooling fluid from the distribution chamber 22 to the corner portion of the cooling cavity 23 has a distribution chamber 22.
It has a structure that is attached so as to project from the corner portion.

Using this plunger 12, the panel 1
At the time of molding 3, the cooling fluid supplied from the central portion of the head body 18 to the distribution chamber 22 inside the plunger 12 is
Since the main cooling chamber 27 located at the corner of the cooling cavity 23 is supplied through the spring nozzle 30, the corner molding surface 20 of the plunger 12 is sufficiently cooled. After that, the cooling fluid in the cooling cavity 23 is discharged from the discharge port 26 communicating with the head body 18.

The plunger 12 having the above structure is
When used for molding a small-sized cathode-ray tube panel 13 of an inch size, the panel 13 is satisfactorily maintained without cracks on the upper inner surface of the flange portion 16 of the panel 13 or the seal edge portion 17 for a long period of time. It was possible to mold.

[0020]

As described above, in the hollow glass product forming plunger of the present invention, the spring nozzle is not damaged at the time of assembly, and when this plunger is used, the inside of the flange portion of the cathode ray tube panel is particularly improved. It is possible to prevent overcooling cracks that occur on the side surface and the seal edge portion, improve the size and molding problems, and improve the molding yield.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view of a plunger of the present invention for forming a cathode ray tube panel.

FIG. 2 is an explanatory view of a state where a cathode ray tube panel is molded.

FIG. 3 is a partial cross-sectional view of a conventional plunger for molding a cathode ray tube panel.

[Explanation of symbols]

 12 Plunger 13 Panel 22 Distribution Chamber 23 Cooling Cavity 30 Spring Nozzle

Claims (1)

[Claims] 1. A distribution chamber in which a cooling fluid is supplied,
In a hollow glass product molding plunger having a cooling cavity located around the distribution chamber, in which a cooling fluid is circulated from the distribution chamber through the cooling cavity to control the temperature distribution on the molding surface, the cooling cavity from the distribution chamber A hollow glass product molding plunger, wherein a spring nozzle for supplying a cooling fluid to the corner part of the hollow glass product is attached so as to project from the corner part of the distribution chamber.