JPS6048453B2 - Danner glass tube drawing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing glass tubes called a tanner glass tube drawing method.

The outline of the tanner glass tube drawing method is as follows.

That is, as shown in FIG. 1, a trough 3 made of a refractory material is provided in the upper part of a Matsufuru furnace 2 constructed of refractory bricks 1, and from the trough 3 molten glass is made into a ribbon shape 4 and is supplied onto a sleeve 5 below. This sleeve 5 is made of refractory material and is sloped (
The sleeve is attached to the mandrel 6 with the tip (lower tip) and rotated together with the mandrel 6 by the sleeve drive device 7. The molten glass flows down onto the upper part of the rotating sleeve 5 and wraps around the rotating sleeve 5 while flowing toward the tip of the sloping sleeve 5.
Cover the entire body uniformly and pull it out of the Matsufuru furnace from the tip of the sleeve 5 as a glass tube 9.

The outer diameter and wall thickness of the glass tube are determined by the temperature and flow rate of the molten glass,
It is determined by conditions such as the pressure of blow air (sent from the rear of the drive device 7 through the mandrel 6 and from the tip of the sleeve 5 into the glass tube 9), the rotational speed of the sleeve, and the speed at which the glass tube is drawn. By the way, the molten glass always flows down to a certain position and the sleeve receives it on the same circumference, so the circumference is eroded by the molten glass and the outer diameter of the sleeve gradually becomes thinner. In this way, if the portion of the sleeve that receives the molten glass is eroded and becomes a deep recess to a certain extent, the wall thickness of the glass tube 9 is likely to be deflected, and the sleeve must be replaced.

Replacing the sleeve is an extremely difficult and high-temperature operation in which the hot sleeve is removed from the drive and a new, preheated sleeve is installed in the drive.

It goes without saying that the tube cannot be drawn during replacement, but even after replacement it takes a considerable amount of time for the outside diameter and wall thickness of the glass tube to stabilize, resulting in considerable production losses. In the case of soda-lime glass, the sleeve can be used for about half a year, but in the case of borosilicate glass, the temperature at the sleeve edge is much higher than in the case of soda-lime glass, so erosion is severe enough to cause deflection of the sleeve. Production efficiency was extremely low.

The present invention was provided in order to improve the above-mentioned problem, and the sleeve is rotated in the direction of the central axis from 1 node to IOT per day.
By moving the WL and changing the location on the sleeve that receives the molten glass, the life of the sleeve is dramatically extended.

The feature of the present invention is that the Danner type device is provided with a moving device shown at 10 in the drawings.

5. The moving device 10 is fixed to the drive device 7 by a bracket 17, and the rotation of the drive motor 14 of the moving device 10 is reduced by a speed reducer 15 to about 1/10,000.

As shown in FIG. 2, a screw shaft 16 connected to the output shaft of the speed reducer 15 is supported by a bearing 20 attached to the moving device 10 and is engaged with a nut 18 fixed to the tilt table 12. The bracket 17 that holds the drive device 7 is a tilting table 12
It is slidably attached to the rail 13 of. Note that 19 is a guide for the bracket 17. When the drive motor 14 of the moving device 10 is rotated while performing a pipe pulling operation in the configuration of the moving device 10 described above, the rotation is reduced to about 1/10,000 by the speed reducer 15 and transmitted to the screw shaft 16.

Since the screw shaft 16 is engaged with a nut 18 and the nut 18 is fixed to the tilting table 12, as the screw shaft 16 rotates, the bracket 17 to which the moving device 10 and the driving device 7 are attached becomes a tilting table. It moves by sliding on 12 rails 13. Accordingly, the sleeve 5 attached to the drive device 7 moves accordingly, and its position for receiving the molten glass changes. Examples using borosilicate glass will be described below. First, the sleeve was set to receive the molten glass as close to the top end as possible, and then the sleeve was moved upward in the direction of the rotation axis to move the molten glass receiving position toward the center. .

When the sleeve was moved manually, the dimensions of the glass tubes, especially the outer diameter, varied greatly, resulting in a large number of glass tubes with defective outer diameters. 2. Ideally, the movement of the sleeve should be very small and continuous.

However, in this embodiment, the reducer 15 allows IT! UTt/9
When I moved the questions discontinuously one by one at a speed as small as 1 minute, there was no practical problem, so 1 field was moved 3 times, that is, 1T1rm every 8 hours, 377!77! Moved it. Erosion of the sleeve varies greatly depending on the glass material, but it is not necessary to move the sleeve for the first few days after replacing it with a new sleeve.

In the case of borosilicate glass for ampules, the lifespan of the sleeve was about 18 days on average with the conventional method, but when the sleeve was moved by 1 nun every 8 hours as described above, there was no problem with the dimensions of the glass tube. I was able to use the same sleeve for 40 days. In this embodiment, the sleeve was moved by 37 nIft per cylinder, but depending on the glass material and the state of corrosion of the sleeve, it is sufficient to move the sleeve 1 to 10 times, that is, about 1 to 10 WfL.

The moving speed is not limited to 1 Tnm/9 minutes, but may be faster as long as it does not adversely affect the dimensions of the glass tube. Furthermore, in this embodiment, the sleeve was moved upward in the direction of the rotation axis, but
It may also be moved downward.

[Brief explanation of drawings]

FIG. 1 is a partially sectional front view of an embodiment of the present invention, and FIG. 2 is a detailed view of the vicinity of the moving device shown in FIG. 4 is a ribbon-shaped molten glass, 5 is a sleeve, 7 is a drive device, 13 is a rail, 14 is a drive motor, 15 is a speed reducer,
16 is a screw shaft, 17 is a bracket, 18 is a nut, 19
is a guide, and 20 is a bearing.

Claims (1)

[Claims] 1. A Danner glass tube drawing method, which is characterized by moving the sleeve at a minute speed in one direction of the sleeve rotation axis.