JP2005289749A - Apparatus and method of manufacturing bent glass pipe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus and method of manufacturing a bent glass pipe by which a straight glass pipe is bent appropriately. <P>SOLUTION: In the method of manufacturing the bent glass pipe, the straight glass pipe 4 is held by a 1st holder 5 and a 2nd holder 6, the glass pipe between both holders 5 and 6 is heated to soften the glass pipe, and the 2nd holder 6 is moved in a circular-arc shape to bend the glass pipe 4 at a softened part. In the bending of the glass pipe 4, the outside diameter of the softened part of the glass pipe 4 is measured by a measuring means 8, the optimum heating temperature of the glass pipe 4 by a heating means 7 is computed by a computing means 9 based on the measured outside diameter and controlling by a control means 10 to heat at a temperature computed by the heating means 7. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a manufacturing apparatus and a manufacturing method for a bent glass tube constituting a bent discharge tube used as a backlight of a liquid crystal display device. The present invention relates to an apparatus and a method for manufacturing a bent glass tube for forming an L-shape.

  As a light source such as a backlight of a liquid crystal display device, a bent discharge tube formed into a U shape, an L shape, or the like is used. In order to manufacture a bent type discharge tube, after forming the glass tube constituting the discharge tube into a U-shape or L-shape, both ends of the glass tube are filled with rare gas or mercury enclosed in the glass tube. There is a sealing method for attaching an electrode to the substrate. However, this method has a problem in terms of cost such that the post-process apparatus becomes complicated, and various types of apparatuses are required for each shape of the glass tube.

  Therefore, when attaching and sealing electrodes on both ends of the glass tube, a rare gas or mercury is enclosed in the glass tube, and then the glass tube is formed into a U-shape or L-shape, thereby bending-type discharge. A method of manufacturing a tube is provided. In this method, for example, a bending apparatus as disclosed in Patent Document 1 is used.

  In this bending apparatus, as shown in FIG. 2, the base 1 and the turntable 2 are connected by a support shaft 3 so that the turntable 2 can rotate around the support shaft 3 as a rotation axis. Yes. The base 1 and the turntable 2 are glass tubes in which mercury or the like is diffused and sealed, and electrodes (not shown) are attached to both ends. The first holding unit 5 and the second holding unit 6 that hold 4 are provided, and the rotating table 2 further includes heating means such as a coil heater (hereinafter referred to as “heater”). 7 is provided.

  The holding parts 5 and 6 and the heater 7 are arranged in a row in the initial state, and the glass tube 4 is held by the holding parts 5 and 6 while being inserted through the coiled heater 7. Then, the second holding unit 6 moves in an arc shape by the rotation of the turntable 2, and half-rotates in the final state to face the first holding unit 5.

  In order to manufacture the bent glass tube 4 in such a bending apparatus, first, as shown in FIG. 2 (a), the turntable 2 is positioned on the side of the base 1, and the straight tubular glass is formed. Both holding portions 5 and 6 hold the glass tube 4 in a state where the tube 4 is inserted through the heater 7. This straight tubular glass tube 4 is filled with rare gas, mercury or the like, and electrodes are attached to both ends.

  Then, a substantially intermediate portion of the straight tubular glass tube 4 is heated by the heater 7. When the heated glass tube 4 is softened, the turntable 2 gradually rotates with the support shaft 3 as a rotation axis, as shown in FIG. At this time, the heater 7 also rotates, and the portion of the glass tube 4 that is closer to the second holding unit 6 is heated than the softened portion. In this way, the glass tube 4 rotates while the second holding unit 6 side is gradually heated, and the rotating table is rotated until the second holding unit 6 faces the first holding unit 5 as shown in FIG. When 2 rotates, a U-shaped bent glass tube 4 is manufactured.

Note that when the L-shaped bent glass tube 4 is manufactured, the turntable 2 stops with the second holding portion 6 rotated by a quarter as shown in FIG. 2B.
Japanese Patent Laid-Open No. 6-243782

  In order to manufacture the bent glass tube 4 from the straight tubular glass tube 4, the heater 7 heats and straightens the straight tubular glass tube 4. However, the temperature at which the glass tube 4 is heated and softened varies depending on the deterioration of the heater and the passage of conduction time even if the temperature setting conditions such as the voltage of the heater are constant. Therefore, unless the temperature setting conditions are changed according to these fluctuation factors, the heating conditions fluctuate and the glass tube 4 cannot be bent properly.

  That is, when the heating temperature is low, the glass tube 4 is not heated sufficiently and is bent without being softened, so that the glass tube 4 is broken. Conversely, when the heating temperature is high, the glass tube 4 is heated too much and the glass melts, so that the inner wall of the glass tube 4 is crushed.

  Then, this invention makes it a subject to provide the manufacturing apparatus of a bending type glass tube and the manufacturing method of a bending type glass tube which enabled it to bend a straight tubular glass tube appropriately.

  An apparatus for manufacturing a bent glass tube according to the present invention includes a heating unit that heats a glass tube, a first holding unit that is disposed on one side of the heating unit and holds one of the glass tubes, and the heating unit. A bending type glass tube manufacturing apparatus provided with a second holding portion which is arranged on the other side of the means and moves while holding the other side of the glass tube and which bends the heated and softened portion. And measuring means for measuring the outer diameter of the bent portion of the glass tube, and setting conditions for the heating means to optimally heat the glass tube based on the outer diameter measured by the measuring means. And a control means for controlling the heating means according to the set condition calculated by the calculation means.

  According to this bent-type glass tube manufacturing apparatus, when the heating means heats the glass tube to soften and bend the glass tube, the bent portion is slightly reduced in diameter, and the outer diameter of the reduced portion is reduced. Is measured by the measuring means, the calculating means calculates the optimum setting condition based on the outer diameter, the control means controls the heating temperature of the heating means, and the heating means heats the glass tube at this temperature. Therefore, since the setting condition is calculated based on the outer diameter and the glass tube is overheated, the glass tube is bent in an optimally softened state. In addition, the setting conditions of the heating means that can bend the glass tube optimally according to the outer diameter of the reduced diameter portion of the glass tube are accumulated as data in the calculation means, and based on this data, A setting condition of the heating means is calculated.

  In the bent glass tube manufacturing apparatus, the measuring means preferably includes a camera and an image processing unit.

  According to this method of manufacturing a bent glass tube, the measuring means includes a camera and an image processing unit, so that the outer diameter of the softened portion of the glass tube photographed by the camera is digitized by the image processing unit. Is done.

  Further, in the method for manufacturing a bent glass tube according to the present invention, the glass tube is held by the first holding portion and the second holding portion, and the space between the holders is heated by a heating means. A method of manufacturing a bent type glass tube that is softened and bent at a portion where the glass tube is softened by movement of the second holding portion, wherein the outer diameter of the portion softened and bent by the measuring means So that the heating means optimally heats the glass tube from the outer diameter measured by the computing means, and the heating means is heated by the control means under the calculated setting conditions. The glass tube is bent by being controlled.

  According to the method of manufacturing a bent glass tube, based on the outer diameter of the softened portion of the glass tube measured by the measuring unit, the calculation unit calculates the setting condition for optimally heating the glass tube, The heating means is controlled by the control means so as to heat the glass tube under the calculated setting conditions. Therefore, since the glass tube is heated under the setting condition calculated based on the outer diameter, the glass tube is bent in a properly softened state, and a bent glass tube can be manufactured appropriately.

  According to the present invention, the outer diameter of the softened portion of the glass tube is measured, and the glass tube is heated at an appropriate temperature to control the temperature under the setting conditions calculated based on the outer diameter. The glass tube is bent in a properly melted state. Therefore, the glass tube is not cracked due to the low heating temperature, and conversely, the heating temperature is high and the inner wall is not crushed, thereby improving the yield and reducing the cost of the glass tube and the discharge tube. Can be planned.

  An embodiment of a bent-type glass tube manufacturing apparatus and method according to the present invention will be described with reference to FIG. However, the same parts as in the prior art will be described with the same reference numerals.

  This bent glass tube manufacturing apparatus is provided with a measuring means 8, a calculating means 9, and a control means 10 in addition to the conventional apparatus. In addition, since a heating means can use a burner etc. other than the heater 7, it demonstrates as the heating means 7 in this embodiment.

  The measuring means 8 is a device for measuring the outer diameter of the portion where the glass tube 4 is heated and softened and bent by the heating means 7, and includes, for example, a camera such as a CCD and an image processing section. When the glass tube 4 is heated and softened and bent, the glass tube 4 is reduced in diameter by being stretched during bending and the internal pressure of the glass tube 4 being lower than the external pressure. This reduced diameter portion is photographed by the camera, the outer diameter is digitized by the image processing unit, and this numeric value is output to the computing means 9.

  The calculating means 9 is an apparatus that calculates the setting conditions of the heating device 7 that optimally heats the glass tube 4 based on the outer diameter measured by the measuring means 8. When the calculation means 9 changes the setting conditions in order to control the outer diameter of the bent portions of the plurality of glass tubes 4 previously measured and the heating temperature appropriate for the outer diameters, the glass tube 4 Data on whether it can be properly softened and bent without cracking or crushing. Therefore, the calculation means 9 calculates a setting condition corresponding to the change value of the heating temperature appropriate for the outer diameter of the glass tube 4 input from the measurement means 8 based on the accumulated data, and this calculation The set condition is output to the control means 10.

  The control means 10 is an apparatus that controls the heating means 7 to heat under the calculated setting conditions. When the heating means 7 is the heater 7, the control means 10 controls the voltage. When the heating means 7 is a burner, the control means 10 controls the gas amount or the distance between the burner and the glass tube 4.

  The bent type glass tube manufacturing apparatus is configured as described above. Next, a method of manufacturing the bent type glass tube 4 using the apparatus will be described.

  First, as shown in FIG. 1, the heating means 7 heats the glass tube 4 while the first holding unit 5 and the second holding unit 6 hold the glass tube 4. The glass tube 4 is filled with rare gas, mercury, or the like, and electrodes are attached to both ends. When the second holding part 6 is moved while the glass tube 4 is heated by the heating means 7, the glass tube 4 starts to bend. At this time, the glass tube 4 is stretched, and the internal pressure of the glass tube 4 is smaller than the external pressure. Therefore, the softened glass tube 4 is reduced in diameter in accordance with the wall thickness, the internal pressure, and other fluctuation factors. The outer diameter of this portion is measured by the measuring means 8, and the dimension is output to the calculating means 9.

  The calculation means 9 calculates a setting condition for achieving an optimum heating temperature for the reduced diameter from the accumulated data, and outputs the calculated setting condition to the control means 10. The control means 10 controls the heating means 7 to heat the next glass tube 4 with the calculated setting condition.

  The glass tube 4 is appropriately softened by being heated at an optimum temperature regardless of the fluctuation factor. Therefore, it is properly folded without being broken or crushed.

  In addition, this invention can be variously changed within the range of the technical matter described in the claim, without being limited to the said embodiment. For example, even if the glass tube 4 does not enclose noble gas, mercury, or the like and has no electrodes attached to both ends, the glass tube 4 is similarly implemented by being stretched and reduced in diameter by being heated and bent. Can do.

  The bent glass tube manufacturing apparatus and the bent glass tube manufacturing method according to the present invention improve the yield and are useful as a backlight of a liquid crystal display device.

The schematic block diagram which shows one Embodiment of the manufacturing apparatus of the bending type glass tube which concerns on this invention It is a schematic block diagram of the manufacturing apparatus of the conventional bending type glass tube, Comprising: (a) is a schematic block diagram of an initial state, (b) is a schematic block diagram of an intermediate state, (c) is a final state Schematic configuration diagram

Explanation of symbols

4 Glass tube 5 1st holding part 6 2nd holding part 7 Heating means 8 Measuring means 9 Calculation means 10 Control means

Claims (3)

A heating means for heating the glass tube; a first holding portion arranged on one side of the heating means; holding one of the glass tubes; and arranged on the other side of the heating means; A bending-type glass tube manufacturing apparatus provided with a second holding portion that moves while holding and bends a heated and softened portion;
Measuring means for measuring the outer diameter of the bent portion of the glass tube, and calculating means for calculating a set value for the heating means to optimally heat the glass tube based on the outer diameter measured by the measuring means; And a control means for controlling the heating means so as to heat at the set value calculated by the calculating means.   The apparatus for manufacturing a bent glass tube according to claim 1, wherein the measurement unit includes a camera and an image processing unit. The glass tube is held by the first holding unit and the second holding unit, the glass tube is softened by heating between the holders by heating means, and the glass tube is moved by moving the second holding unit. A method of manufacturing a bent glass tube that is bent at a softened portion,
The outer diameter of the bent portion is measured by a measuring means, a setting value for optimally heating the glass tube by the heating means is calculated from the measured outer diameter by an arithmetic means, and the heating means is calculated by a control means. A method of manufacturing a bent glass tube, wherein the glass tube is bent by controlling to heat at the calculated set value.

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