JPH05116965A - Apparatus for producing glass tube - Google Patents

Abstract

PURPOSE:To efficiently and stably produce a glass tube having a prescribed outside diameter with simple operations. CONSTITUTION:Glass tube outside diameter measuring means 12, 13 which respectively measure the outside diameters are disposed near a sleeve 1 and just before a cutting means 8 for the glass tube formed by a tube-drawing. This apparatus is so constituted as to control the pressure gas to be supplied by continuously computing the outside diameter control of the glass tube in accordance with the measured values by these glass tube outside diameter measuring means. Namely, the glass tube changed in the outside diameter by adjusting the blow pressure is subjected to the primary measurement of the outside diameter by the 1st glass tube outside diameter measuring means 12 at the point of this time. On the other hand, the outside diameter is measured by the 2nd glass tube outside diameter measuring means 13 even at the point of the time when the glass tube is cut as the final product. The measured values by the two glass tube outside diameter measuring means 12, 13 are both instantaneously fed back to the control of the pressure gas to be supplied. The wasteful time is decreased and eliminated and the exact adjustment of the corresponding blow pressure is possible.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a glass tube manufacturing apparatus capable of continuously and easily manufacturing a glass tube having a predetermined outer diameter.

[0002]

2. Description of the Related Art As is well known, glass tubes are widely used, for example, in the construction of fluorescent lamps, and in the manufacture of fluorescent lamps, the quality of the fluorescent lamps manufactured and other factors also contribute to the production of glass tubes. It is desired to have a constant outer diameter according to By the way, the following means are generally adopted for manufacturing a glass tube. That is, as shown in a schematic cross-sectional view in FIG. 3, a sleeve 1 arranged in an oblique direction and rotating, a molten glass supply source 3 for dropping molten glass 2 on the peripheral surface of the sleeve 1 on the upper end side, A gas pressure feed passage 4 penetrating along the axis of the sleeve 1 and a molten glass 2'carried on the peripheral surface of the sleeve 1 are supplied with a pressure gas through the gas pressure feed passage 4 to thereby provide the sleeve 1 At the lower end side, a pressurized gas supply source 5 for turning the molten glass 2'to a required outer diameter, at the lower end side of the sleeve 1, a tube drawing means 6 for drawing a tube while forming a valve, and a tube drawing / forming by the tube drawing means 6 A glass tube cutting means 8 for cutting the formed glass tube 7 to a required length, and a glass tube outer diameter measuring means 9 for measuring the outer diameter of the glass tube which is valved to the required outer diameter in the vicinity of the tube drawing means 6. , The pipe drawing
Pipe drawing speed measuring means 10 arranged immediately before the cutting means 8 position of the formed glass tube 7 to measure the drawing / forming speed of the glass tube 7 to be cut, and a signal from the tube drawing speed measuring means 10 and the outside of the tube. Blow pressure control means for controlling the gas supply pressure from the pressurized gas supply source 5 based on the measurement result of the diameter measuring means 9.
A glass tube manufacturing apparatus comprising 12 is known.

Next, the operation of the glass tube manufacturing apparatus having the above structure will be described.

Molten glass 2 dropped from the molten glass supply source 3 on the peripheral surface on the upper end side of the sleeve 1 is wrapped around and carried on the peripheral surface of the rotating sleeve 1 and moves to the lower end (tip) side by gravity. And the lower end (tip) of the sleeve 1
The molten glass 2 ′ that has reached the side is drawn by the tube drawing means 6 while forming a bulb. That is, at this time, the gas pressure feed passage 4 provided so as to penetrate along the axis of the sleeve 1
The molten glass 2'is pipe-drawn by the pipe-drawing means 6 on the lower end side of the sleeve 1 while being valved to a required outer diameter by the pressurized gas supplied via the pipe. Then, the glass tube 7 formed by this tube drawing is cut into a required length by the glass tube cutting means 8 to obtain a required glass tube. In this glass tube manufacturing process, the outer diameter and the wall thickness of the glass tube are the tube drawing (pulling) speed by the tube drawing means 6 and the gas pressure (pneumatic pressure) supplied (introduced) through the gas pressure passage 4 of the sleeve 1. Etc.) and the amount of the molten glass 2 dropped (supply amount).

On the other hand, in the above-mentioned glass tube manufacturing process, a value obtained by dividing the distance from the tip of the sleeve 1 to the glass tube outer diameter measuring means 9 by the tube drawing speed is regarded as a dead (delay) time. The blow pressure control means 12 controls the gas supply pressure from the compressed gas supply source 5 based on the measured value (outer diameter deviation signal) by the glass tube outer diameter measuring means 9 to continuously produce glass tubes. The outer diameter and wall thickness are controlled.

[0006]

However, the glass tube manufacturing apparatus having the above structure has the following inconvenient problems. That is, in the case of the above glass tube manufacturing apparatus, the outer diameter value is read by one glass tube outer diameter measuring means 9 arranged in the vicinity of the glass tube cutting means 8 for cutting the drawn glass tube 7, and the outer diameter value is read. The configuration is such that the outer diameter is calculated so as to match the standard median value (design value), and the blow pressure control means 12 outputs the supply pressure gas (blow pressure) value. Therefore, if the drawing line of the glass tube 7 becomes long (may be several tens of meters), a phenomenon occurs in which the blow pressure adjustment (adjustment) does not correspond to the outer diameter of the actually manufactured glass tube. In other words, it takes several seconds to several minutes (delay time) for the glass tube whose blow pressure is adjusted to change the outer diameter to actually reach the glass tube outer diameter measuring means 9. It is practically difficult to adjust the pressure or control the glass tube outer diameter measuring means 9, and it is impossible to achieve a constant outer diameter control.

On the other hand, in recent years, it has been attempted to integrate the outer diameter control means of the glass tube and the blow pressure control means into a single control device. However, in the case of a configuration including a control device in which the outer diameter control means of the glass tube and the blow pressure control means are integrated, the primary pressure of the blow pressure generation source is likely to change due to fluctuations in the power supply voltage, and the blow pressure is likely to change. When there is a change or when some disturbance that changes the outer diameter of the glass tube occurs, due to the dead (delay) time as described above,
There is a problem that the outer diameter of the manufactured glass tube varies.

In any of the conventional means, there is a problem that due to the existence of the above-mentioned problems, the type of glass tube to be manufactured must be changed or the control constant must be changed between daytime and nighttime. There is an inconvenience that the manufacturing operability (mass productivity) is poor.

The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a manufacturing apparatus capable of easily manufacturing a glass tube having a predetermined outer diameter with high efficiency and stability.

[0010]

SUMMARY OF THE INVENTION A glass tube manufacturing apparatus according to the present invention comprises a sleeve arranged obliquely and rotating,
A molten glass supply source for dropping molten glass onto the peripheral surface on the upper end side of the sleeve, a gas pressure feed passage penetrating along the axial center of the sleeve, and a molten glass carried on the peripheral surface of the sleeve. A pressure gas supply source for supplying a pressure gas through a gas pressure feeding path to valve the molten glass to a required outer diameter on the lower end side of the sleeve; Glass tube cutting means for cutting the glass tube drawn / formed by the tube drawing means to a required length, and first measuring the outer diameter of the glass tube valved to the required outer diameter in the vicinity of the rotating sleeve.
Glass tube outer diameter measuring means, second glass tube outer diameter measuring means arranged immediately before the cutting means position of the glass tube formed and drawn, and measuring the outer diameter of the glass tube to be cut; The amount of deviation of the measured value by the glass tube outer diameter measuring means is calculated and compared with the amount of deviation of the measured value by the first glass tube outer diameter measuring means to control the pressurized gas supplied through the gas pressure feeding passage. And a gas control means.

[0011]

In the glass tube manufacturing apparatus according to the present invention,
Glass tube outer diameter measuring means for measuring the outer diameter are arranged in the vicinity of the sleeve and immediately before the cutting means position of the drawn / formed glass tube. Based on this, the glass tube outer diameter control is continuously calculated to control the pressurized gas to be supplied. That is, for the glass tube whose blow pressure is adjusted to change the outer diameter, the outer diameter is primarily measured by the first glass tube outer diameter measuring means at that time, while the glass tube is cut as the final product. However, the outer diameter is measured by the first glass tube outer diameter measuring means, and the mutual measurement values of both the glass tube outer diameter measuring means are fed back to the control of the pressurized gas supplied instantaneously. In other words, the control calculation of the supply pressure gas is performed by the measured values at a plurality of points separated from each other, so that the so-called dead time (delay time) is substantially generated.
Will be greatly reduced and eliminated, and the blow pressure can be adjusted appropriately. Therefore, in manufacturing a glass tube, it is possible to always achieve a predetermined (constant) outer diameter control in a stable state.

[0012]

Embodiments of the present invention will be described below with reference to FIGS.

FIG. 1 is a block diagram showing the outline of the structure of a glass tube manufacturing apparatus according to the present invention, wherein 1 is a sleeve which is obliquely arranged and rotates, and 3 is a molten glass on the peripheral surface of the upper end of the sleeve 1. A molten glass supply source for dripping 2 is a gas pressure feed passage 4 which penetrates along the axis of the sleeve, and a gas pressure feed passage 4 is a gas pressure feed passage 4 for a molten glass 2'carried on the peripheral surface of the sleeve 1. Through pressurized gas (blow pressure)
To supply a pressure gas supply source (for example, an air blow pressure generator) for making the molten glass 2'at the lower end side of the sleeve 1 into a required outer diameter, and 6 while making the molten glass 2'at the lower end side of the sleeve 1 as a valve. A tube drawing means for drawing the tube at a predetermined speed, and a glass tube cutting means 8 for cutting the glass tube 7 drawn and formed by the tube drawing means 6 into a required length. Further, 12 is a first glass tube outer diameter measuring means for measuring the outer diameter of the glass tube 7 valved to a required outer diameter in the vicinity of the rotating sleeve 1, and 13 is the glass tube cutting means formed and drawn. Second glass tube outer diameter measuring means arranged immediately before the 8th position to measure the outer diameter of the glass tube 7 to be cut,
Reference numeral 14 calculates the deviation amount of the measured value by the second glass tube outer diameter measuring means 13 and compares it with the deviation amount of the measured value by the first glass tube outer diameter measuring means 12 and supplies it via the gas pressure feeding path 4. It is a supply pressure gas control means for controlling the pressure gas to be applied.

That is, although the glass tube manufacturing apparatus according to the present invention has the same basic configuration as that of the conventional case, a plurality of glass tube outer diameter measuring means are arranged and the glass tube outer diameter measuring means is arranged. Sleeve 1 as the position to place
To select the vicinity and immediately before the position of the glass tube cutting means 8 and to control the blow pressure by calculating an optimum blow pressure set value based on the outer diameter measurement values of these glass tube outer diameter measurement means. It can be said that these functions are added.

Next, an explanation will be given of the points of the operation example or the usage example of the glass tube manufacturing apparatus having the above-mentioned structure.

First, the molten glass 2 dropped from the molten glass supply source 3 on the peripheral surface on the upper end side of the sleeve 1 is wrapped around and carried on the peripheral surface of the rotating sleeve 1 and moved to the lower end (tip) side by gravity. .. The molten glass 2 ′ reaching the lower end (tip) side of the sleeve 1 is drawn by the drawing means 6 at a constant speed while forming a valve. That is, at this time, the molten glass 2'is valved to the required outer diameter on the lower end side of the sleeve 1 by the pressurized gas supplied through the gas pressure feeding passage 4 provided penetrating along the axis of the sleeve 1, It is drawn by the drawing means 6.
The outer diameter of the drawn glass tube 7 is measured by the second glass tube outer diameter measuring means 13 arranged immediately before the position of the glass tube cutting means 8.

The measured value (data) PV ₂ is shown in FIG.
As shown in the block diagram in
PV of PID ₂ operation block after smoothed through DF _2.
It becomes an input, and here the PID for the outer diameter target value (setting value)
The operation output MV ₂ is calculated. That is, the difference (deviation) between the outer diameter data obtained by the second glass tube outer diameter measuring means 13 and the standard median value ... target value (set center value) is calculated,
The operation output MV ₂ that is the outer diameter target value (set value) in the first glass tube outer diameter measuring means 12 is determined, and the sensitivity is adjusted by the ratio setting RB.

On the other hand, the first glass tube outer diameter measuring means 12
The outer diameter data PV ₁ measured by is smoothed through the digital filter DF ₁ , and then is compared PID calculation (deviation calculation) at the output SV ₁ of the ratio setting RB block and the PID ₁ block. This comparison PID Calculated PID
The output MV ₁ from _one block becomes the target value (set value) SV _{3 of} the blow pressure control means 14. PID calculation is performed in the PID ₃ block to output the operation output MV ₃ so that the actual blow pressure PV ₃ with respect to this target value SV ₃ exhibits the same value. The operation output MV ₃ thus output automatically controls the blow pressure on-off valve of the supply pressure (blow pressure) control means 14 to set the optimum blow pressure for the target value (set value) SV ₃ . Will be retained. Moreover, since the first glass tube outer diameter measuring means 12 is arranged close to the sleeve 1 and has a shape in which the dead time is reduced, the target value in the second glass tube outer diameter measuring means 13 is set. With respect to the (set value), a glass tube having a predetermined outer diameter is manufactured in a stable (constant) state in response to a quick dry.

The glass tube manufacturing apparatus according to the present invention is not limited to the above-mentioned constitutional example, and for example, glass tube outer diameter measuring means may be installed at three or more places, and each glass tube outer diameter measuring means. The blow pressure control means may be arranged corresponding to the means to further improve the accuracy.

[0020]

As described above, according to the glass tube manufacturing apparatus of the present invention, at the start of tube drawing (position close to the sleeve 1), near the cutting position of the drawn / formed glass tube. The outer diameter of each glass tube is measured, and the outer diameter control of the glass tube to be drawn / formed is calculated based on these measured values (data). In other words, pull the glass tube
When forming (pulling at a constant speed), the blow pressure, which greatly affects the change or accuracy of the outer diameter, is easily and promptly controlled, and vibration of the outer diameter is suppressed and reduced. It is possible to mass-produce a glass tube with a constant outer diameter in a state in which disturbances such as changes in flow rate (dropping amount) and temperature can be almost ignored.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration example of a main part of a glass tube manufacturing apparatus according to the present invention.

FIG. 2 is a block diagram for explaining an outer diameter measurement and a supply gas pressure (blow pressure) control means for drawing and forming a glass tube in the glass tube manufacturing apparatus according to the present invention.

FIG. 3 is a cross-sectional view schematically showing a configuration of a main part of a conventional glass tube manufacturing apparatus.

[Explanation of symbols]

1 ... rotatable sleeve 2, 2 '... molten glass
3 ... Molten glass supply source 4 ... Gas pressure feeding path 5 ... Pressure gas supply source 6 ... Pipe drawing means 7 ... Glass tube formed / formed 8 ... Glass tube cutting means 9 ... Outer diameter measuring means 10 ... Pipe drawing speed measurement Means 11 ... Blow pressure control means 12 ... First glass tube outer diameter measuring means 13 ... Second glass tube outer diameter measuring means
14 ... Supply pressure (blow pressure) control means

Claims (1)

[Claims] 1. A sleeve which is arranged in an oblique direction and rotates, a molten glass supply source for dropping molten glass onto the peripheral surface on the upper end side of the sleeve, and a gas pressure feed provided penetrating along the axis of the sleeve. A channel, a pressure gas supply source for supplying a pressure gas to the molten glass carried on the peripheral surface of the sleeve through a gas pressure feed channel to valve the molten glass to a required outer diameter on the lower end side of the sleeve, and the sleeve. A tube drawing means for drawing a tube while forming a valve at the lower end side, a glass tube cutting means for cutting a glass tube drawn / formed by the tube drawing means to a required length, and a required outer diameter near the rotating sleeve. A first glass tube outer diameter measuring means for measuring the outer diameter of the bulbized glass tube, and an outer diameter of the glass tube to be cut and arranged immediately before the cutting means position of the glass tube formed and drawn. Second glass tube outer diameter measuring means,
The amount of deviation of the measured value by the second glass tube outer diameter measuring means is calculated and compared with the amount of deviation of the measured value by the first glass tube outer diameter measuring means to control the pressurized gas supplied through the gas pressure feeding path. And a supply pressure gas control means for controlling the glass tube.