JPH06219758A - Method of melting and cutting glass rod material - Google Patents

Abstract

PURPOSE:To prevent a round glass rod after cutting from bending at the tip in cutting a molten glass rod. CONSTITUTION:Edges of a pair of cutting members 3 are crossed, a glass rod material 1 is cut and simultaneously the glass rod material 1 is moved above the cutting members 3. Consequently, the tip part of the glass rod material 1 is prevented from being pushed by one cutting member 3 and bent.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for melting and cutting a glass rod.

[0002]

2. Description of the Related Art Recently, a method for producing a glass molded part having high shape accuracy and surface quality by simply heating and pressing a glass rod without the need for grinding and polishing has been established. As such a manufacturing method, a manufacturing method applying a direct press method which has already been put into practical use is considered. According to this direct press method, a molten glass lump of a predetermined amount obtained by cutting the molten glass heated and melted in the crucible and flowed down from the orifice with a cutting member such as a shear at a predetermined timing is supplied to the mold, Since press molding is performed thereafter, the processing steps are significantly shortened as compared with the grinding / polishing processing method, and it becomes possible to significantly reduce the processing cost of the glass optical component.

In the direct press system, the cutting of the molten glass is generally carried out by driving a pair of cutting members facing each other in a direction transverse to the molten glass at a right angle. In the cutting of the molten glass by such a method, there is a problem that air is apt to be entrained in the molten glass at the time of cutting, and a defective appearance portion called a shear mark is generated on the surface of the obtained glass gob. In order to solve this problem, in the method and apparatus for cutting outflow molten glass disclosed in Japanese Patent Publication No. 52-19209,
Cut the molten glass toward the center without squeezing by using two rotating left and right V-shaped cutting members and engaging them with their turning radii different and their circumferential orbits offset from each other. A method of doing so is disclosed.

On the other hand, in the conventional direct press system, raw materials are put into a crucible for melting glass,
Since this is collectively melted by heating, one lot is 100k
It was not suitable for small-lot production of less than g. Further, when the glass material to be melted is changed, the crucible must be replaced and the cleaning work must be carried out each time, which causes an increase in setup time and a significant reduction in production efficiency. Therefore, conventionally, a method is known in which a round glass rod is used as a glass material, and the tip end portion thereof is heated and melted and cut to be applied to small-lot production.

[0005]

However, when the round glass rod is cut by the conventional cutting method, there arises a problem as shown in FIG. In FIG. 4, the tip 2 of the glass rod 1 is heated and melted by a heating means (not shown). As shown by A, the pair of cutting members 3 are driven to start cutting while traversing the tip 2 of the glass round bar 1. Then, as shown by B, when the cutting edges of the cutting members 3 intersect with each other, the cutting of the tip portion 2 is completed and the molten glass gob 5 is formed. However, as indicated by C, when the cutting members 3 cross each other, the tip edge surface 6 of the upper cutting member of the cutting member 3 comes into contact with the post-cutting tip 4 of the glass round bar 1 so that the portion is laterally (upper side). Since the cutting member is pressed in the advancing direction of the cutting member, the tip 4 is bent after cutting. Further, even after the cutting member 3 returns to the original position and the tip blade tip surface 6 and the post-cut tip portion 4 are separated from each other, the heat of the post-cut tip portion 4 is removed by the tip blade tip surface 6 during the contact. , The tip 4 after cutting
The bending will not be restored to its original shape and will remain bent. The above-mentioned bending phenomenon is described in Japanese Patent Publication No. 52-19.
It does not disappear even by the molten glass cutting method disclosed in Japanese Patent No. 209, and it similarly occurs.

When the bending phenomenon occurs, not only does the weight of the next molten glass gob vary depending on the degree of bending, but also the stability of the position where the molten glass gob falls falls, and good glass optical parts are obtained. Will not be able to get. On the other hand, for example, as shown in FIG. 5, a pair of cutting members 3
The blade height is arranged in the same manner, and the above-mentioned problem does not occur when cutting by abutting the blade edges,
In this method, since the cutting edges are repeatedly brought into contact with each other, the cutting edges may be damaged or blunted, and the life of the cutting member 3 may be significantly shortened.

The present invention has been made in view of the above problems of the prior art, and when cutting a molten glass rod, a glass rod that can be cut without bending the tip of the cut glass rod. It is an object to provide a method for melting and cutting a material.

[0008]

In order to achieve the above object, the present invention, as shown in the conceptual diagram of FIG. 1, heats and melts a tip portion 2 of a glass rod 1 to form a pair of the tip portions 4. In the method for melting and cutting a glass rod by cutting with the cutting member 3, the pair of driven cutting members 3 intersect with each other to cut the tip 2 of the glass rod 1 and at the same time, the post-cutting tip 4 of the glass rod 1 is cut. The glass round bar 1 is moved up to a position where does not contact the upper cutting member of the cutting member 3.

[0009]

According to the above construction, since the tip 4 of the glass rod 1 after cutting is separated from the tip blade surface of the cutting member 3, the tip of the glass rod 1 after cutting is moved by the movement of the cutting member 3 after the completion of cutting. The part 4 does not bend.

[0010]

EXAMPLE 1 FIG. 2 is a schematic view showing an apparatus used for carrying out the melt cutting method of Example 1 of the present invention. In the figure, one of the cutting members 3 is arranged so that its tip (blade) is at a distance of L / 2 with respect to the center of the glass rod 1. That is, the distance between the tips of the pair of cutting members 3 is L. Each cutting member 3 has a drive source A
7 and the glass round bar 1 is connected to the drive source B8. The driving source A7 and the driving source B8 are connected to the controller 9, the glass round bar 1 is moved upward by the driving source B8 which receives the signal from the controller 9, and the cutting member 3 is driven by the signal received from the controller 9. It is adapted to be moved forward and backward by the source A7. Where the controller 9
Means that when the cutting member 3 advances L / 2 from the initial position and the tip ends intersect, the glass round bar 1 is moved to the thickness t + of the cutting member 3.
It is set to send a signal to the drive source B8 in order to increase the movement amount by 2 mm. The rising speed of the round glass rod 1 is set to be the same as the forward speed of the cutting member 3.

Next, a first embodiment of the cutting method according to the present invention will be described together with its operation. First, the forward movement of the cutting member 3 is started by the drive source A7, and the melting tip 2 of the glass round bar 1 is started.
Start cutting. Then, when the cutting member 3 advances by L / 2, the respective tips intersect and complete the substantial cutting of the glass round bar 1. However, the stroke amount of the cutting member 3 is set to perform more reliable cutting. Since it is larger than L / 2, it will move further forward. Then, when the cutting member 3 advances L / 2 forward, the drive source B8 which receives a signal from the controller 9 raises the glass round bar 1 at the same speed as the forward speed of the cutting member 3 to cut the glass round bar 1. The rear tip 4 rises to a position higher than the upper surface of the cutting member 3, that is, a position where it does not interfere with the tip cutting edge surface 6 of the upper cutting member, and then stops.
As a result, after the cutting members 3 cross each other, the tip edge surface 6
On the other hand, since the round glass rod 1 is always separated, the bending of the front end portion 4 after the cutting of the round glass rod 1 is prevented. According to this embodiment, it is possible to prevent bending of the front end portion 4 after cutting when the glass round bar 1 is cut by an extremely simple means.

[0012]

[Embodiment 2] FIG. 3 is a schematic view showing an apparatus used for carrying out the melt cutting method according to Embodiment 2 of the present invention. A sensor A10 is arranged on the upper surface of one cutting member 3a of the pair of cutting members 3, and the glass round bar 1 is provided from the tip of the cutting member 3a.
The distance Y1 to the side surface of the can be detected.
A sensor B11 is installed on the upper surface of the other cutting member 3b so that the distance Y2 from the tip of the cutting member 3b to the side surface of the glass round bar 1 can be detected. further,
The sensor C12 is arranged on the side surface of the cutting member 3a, and the reference plate 13 is installed on the side surface of the cutting member 3b.
The sensor C12 detects the distance from the reference plate 13 to detect the distance X between the tips of the cutting members 3a and 3b.

The sensors A10 and B11 are connected to the controller A14. The cutting member 3a and the cutting member 3b are connected to the drive source A7. The drive source A7 is connected to the controller A14 so that the cutting member 3a and the cutting member 3b can be independently moved forward and backward by a signal from the controller A14. The sensor C12 is connected to the controller B15. Controller B15
Is connected to a drive source B8 for the glass rod 1, and the drive source B8 moves the glass rod 1 up and down in response to a signal from the controller B15.

Next, a second embodiment of the cutting method according to the present invention will be described together with its operation. First, the sensor A10 and the sensor B11 detect the distance Y1 and the distance Y2. At this time, if Y1 <Y2, only the cutting member 3b starts moving forward, and conversely, if Y1> Y2, only the cutting member 3a starts moving forward. Then, when Y1 = Y2, the advance of the other cutting member (the cutting member 3a when Y1 <Y2 and the cutting member 3b when Y1> Y2 under the above conditions) is started. Thereby, even if the initial position of the round glass rod 1 is off center with respect to the tips of the cutting members 3a and 3b, it can be corrected. The cutting members 3a and 3b move forward, and the sensor C1
When the distance X detected by 2 becomes 0, the tips of the cutting members 3a and 3b start to intersect with each other, and the substantial cutting is completed at this stage. Then, at this point, the drive source B8 is activated by a signal from the controller B15, the glass rod 1 starts to rise, and stops above the cutting member 3b. As a result, regardless of the initial position of the glass rod 1, the glass rod 1 can be released upward at the most appropriate timing.

According to this embodiment, the cutting members 3a and 3b are independently driven, and the glass round bar 1 and the cutting member 3 are driven.
Since the position of the cutting member 3b and the position of the cutting member 3b are constantly detected and controlled, cutting can be performed with higher reliability. Especially when the diameter of the glass round bar 1 is as small as 1-2 mm, the glass round bar 1
Even if the timing of raising is slightly deviated, the tip portion after cutting is likely to be bent, and therefore the control of this embodiment is effective.

In each of the above embodiments, the case where a round glass rod is used as the glass rod has been described, but a glass square rod, a hexagonal rod or the like can be used according to the purpose. Even in this case, it is possible to obtain the same effect as that of each of the above embodiments.

[0017]

As described above, according to the method for melting and cutting a glass rod according to the present invention, the glass rod is lifted at the same time when the pair of cutting members cross each other. No bending occurs. Therefore, even when the glass rod is continuously cut, it is possible to suppress the variation in the weight of the molten glass gob and the variation in the supply position. Therefore, since it is possible to supply a very good quality molten glass gob to a fixed position, it is possible to greatly contribute to the quality improvement of the glass optical component obtained by the press forming which is the post-processing.

[Brief description of drawings]

FIG. 1 is a conceptual diagram showing a cutting step of a glass rod material melt cutting method according to the present invention.

FIG. 2 is a schematic view showing an apparatus used for carrying out the cutting method of Example 1 of the present invention.

FIG. 3 is a schematic view showing an apparatus used for carrying out the cutting method of Example 2 of the present invention.

FIG. 4 is a process diagram showing a conventional cutting method.

FIG. 5 is a process diagram showing a conventional cutting method.

[Explanation of symbols]

 1 Glass round bar 2 Tip part 3 A pair of cutting members

Claims (1)

[Claims] 1. A method for melting and cutting a glass rod, wherein the tip of a glass rod is heated and melted, and the tip is cut by intersecting a pair of cutting members. A method for melting and cutting a glass rod, comprising moving the rod in a direction away from the cutting member.