JP2010001166A - Rotary roller device for conveying glass body and roller conveyer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a rotary roller device for conveying a glass body which hardly damages the surface of the conveyed glass body and has wear resistance to prolong the life. <P>SOLUTION: The rotary roller device 21 is provided with a shaft 35 having a gas jetting hole 37 jetting a gas and formed on the side surface to form a gas bearing and a rotary roller 21a fitted to the shaft 35, having an annular groove 31 for guiding the glass body G1 and rotating around the shaft 35, wherein the rotary roller 21a comprises a roller body 30 having the annular groove 31 formed on the outer surface, having a shaft hole 32 in the rotary shaft side and formed from a heat resistant resin and a bush 33 of a metallic pipe body which is fitted so that the outer surface is brought into close contact with the inner surface of the shaft hole 32 of the roller body 30 and the inner surface forms an air layer between the inner surface and the side surface of the shaft 35 to form a bearing. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a rotating roller device for transporting a glass body and a roller conveyor used in a glass tube forming apparatus that draws and forms a glass tube from molten glass.

In the glass tube forming device, a forming device such as a dunner method is used in which a molten glass is drawn into a tube shape, and a plastically deformed tube is transported and solidified in a horizontal state, and a rotating roller device using an air bearing is used as a transport conveyor. Is used. The roller is made of graphite having a low friction coefficient as a material, and prevents the heated glass tube from being deformed or scratching the surface (see Patent Document 1 and Patent Document 2).
Japanese Examined Patent Publication No. 45-24464 Japanese Utility Model Publication No. 63-89937

  Even when using a gas bearing with low rotational friction, the metal roller tends to damage long glass bodies such as the glass tube being conveyed, and the graphite roller has the disadvantage that it is not resistant to wear and has a short life. No rotating roller device was desired.

  The present invention has been made in view of the above, and provides a wear-resistant and long-life glass body rotating roller device that hardly damages the surface of the glass body being conveyed.

  The present invention relates to a shaft which forms a gas bearing by forming a vent hole for injecting a gas on a side surface, and a rotating roller which is inserted into the shaft and has an annular groove for guiding a glass body and rotates around the shaft. A rotating roller device comprising: a roller body formed of a heat-resistant resin having an annular groove formed on an outer surface thereof and a shaft hole on a rotating shaft side; and an outer surface of the roller body. A glass body conveyance comprising a bush of a metal tube which is closely attached to the inner surface of the shaft hole and is inserted so that an inner surface forms an air layer between the side surface of the shaft and a bearing is formed. The rotary roller device for use is obtained.

  The rotating roller device for conveying a glass body according to the present invention has a roller body having an annular groove that is in contact with a traveling glass body (glass tube, solid glass body) made of heat-resistant resin, and the rotating portion of the gas bearing is a metal tube body. Therefore, the heat of the roller body received at the contact portion of the hot glass body does not stay in the vicinity of the contact portion, but is conducted to the bush of the metal tube body with excellent thermal conductivity. Cooling fins are quickly cooled by, for example, an air medium of a gas bearing that is injected from the vent hole of the shaft. For this reason, the roller main body is not partially overheated, wear resistance is maintained, and the life is extended.

  In addition, since the processing accuracy of the metal tube is higher than that of the resin, the gas bearing performance similar to that of the metal roller can be obtained, and the specific gravity of the entire roller is small and the weight is light. A conveyor with reduced running costs can be obtained.

  The present invention uses a heat resistant resin for the roller body of the rotary roller device. Here, the heat-resistant resin is a fluororesin (PTFE, PFA, FEP, PVDF, etc.), a liquid crystal polymer (polycondensate of 2,6-hydroxynaphthoic acid and parahydroxybenzoic acid [type III], etc.), heat resistance A resin having a heat resistance of 260 ° C. or higher such as a polyamide-imide resin is called. Further, a filler can be added to increase the hardness, and carbon powder, silicon powder, carbon fiber and other materials can be selected as the filler.

  In the formation of a long glass body, for example, a glass tube, a roller conveyor is used when molten glass is made to flow in a tubular shape and is naturally dropped and guided horizontally to be solidified into a glass tube. The glass tube is cooled from 500 ° C. to 100 ° C. or less while the glass tube is solidified from the tubular softened state and cut into a fixed length glass tube, and the glass tube is guided on a rotating roller device arranged with an interval therebetween. Be transported.

  Some heat resistant resins can withstand about 260 ° C. to 400 ° C., and fluororesins and liquid crystal polymers can be used up to around 300 ° C., and the present inventor can replace most of the roller conveyor with rollers of this heat resistant resin. I found it. For example, the fluororesin itself has a low friction coefficient, and the friction coefficient is further reduced at 200 ° C. to 300 ° C., which is necessary for a glass tube conveyor. Hardness at the same temperature can be increased.

  However, the resin roller has several problems for conveying a hot glass body. One is that heat conductivity is low because heat conductivity is low, and the other is that workability is low, so the amount of gas introduced into the bearing is different due to the difference in processing accuracy in units of 10 μm, such as a gas bearing. Excess gas must be supplied and consumed for the variable.

  These problems are improved by applying a metal tube to the roller bearing.

  The metal tube body can be in close contact with the shaft hole portion of the resin main body to quickly diffuse the heat, and is forcedly air-cooled by the introduced gas that forms the gas layer of the gas bearing. Furthermore, since the inner surface of the metal tube can be finished with high accuracy, the gap of the gas layer between the shaft supporting the rotating roller device can be kept constant, and the gas feed amount for the gas bearing is minimized. The running cost can be increased.

  Embodiments will be described below with reference to the drawings.

(Embodiment 1)
FIG. 1 and FIG. 2 illustrate this embodiment. FIG. 1 is a schematic view of a danna-type glass tube forming apparatus, and FIG. 2 is a schematic cross-sectional view of a rotating roller apparatus used for the roller conveyor.

  In the glass tube forming apparatus 10, a glass melting container 12 that holds and stores the molten glass G drawn from the glass melting furnace at a predetermined temperature is disposed above the muffle furnace 11. Below the orifice 13 formed at the bottom of the glass melting vessel 12 and opening into the muffle furnace 11, a sleeve 15 disposed in the muffle furnace 11 and rotated in a predetermined direction at a predetermined rotational speed by a drive mechanism 14 is provided. I have. The sleeve 15 is inclined at a predetermined inclination angle so that the front end is downward, and a gas pressure feed path 16 is provided through the sleeve 15 along the axial center of the sleeve 15, and a pressure gas supply source 17 is provided through the gas pressure feed path 16. The blow air supplied from is ejected from the tip opening.

  The molten glass G0 having an appropriately adjusted viscosity flows down from the orifice 13 of the glass melting container 12 in a ribbon shape and winds around the base side surface above the sleeve 15. Thereafter, the wound molten glass G0 moves from the base side to the lower tip side by gravity, is formed into a tubular glass G1 by blow air of a predetermined pressure ejected from the tip opening, and is conveyed on the roller conveyor 20. The tube is drawn in the direction of arrow g by the tube drawing machine 18. The glass tube G2 that has passed through the tube drawing machine 18 is cut to a required size by a cutting machine 19.

  The roller conveyor 20 is a conveyor line of a plurality of rotating roller devices 21 arranged along the direction g in which the glass tubes G1 and G2 are conveyed. The rotary roller device has a gas bearing configuration, and a gas introduction tube 23 is connected to each rotary roller device, and each gas introduction tube 23 is connected to a high-pressure gas supply source 24.

  The rotating roller device 21 that conveys the glass tube as a long glass body includes a rotating roller 21a, and includes, for example, a drum-shaped heat-resistant resin roller body 30 having an annular groove 31 on the outer surface. A shaft hole 32 penetrating through the center of the rotation shaft is formed. A cylindrical metal tube bush 33 is fitted into the shaft hole 32. The outer surface of the bush is in close contact with the inner surface of the shaft hole 32 of the roller body 30 using the elasticity of the roller body. Both end surfaces of the roller body 30 and the bush are formed flush with each other.

  The bush 33 is rotatably attached to the metal shaft 35. The shaft 35 has a gas flow path 36 formed in the shaft along the axis, and a plurality of gas injection holes 37 extend radially from the gas flow path 36 to the side surface of the shaft. The base of the shaft 35 is cantilevered by a bracket 38 and is fixed by a cap retainer 39 and a nut 40. Both end surfaces of the rotating roller 21a are sandwiched between disc-shaped caps 41 and 42, and axial movement on the shaft is restricted. The shaft base side cap 42 is fixed by a shaft 35 and a cap retainer 39, and the shaft tip end cap 41 is fixed by a bolt. A gap through which the gas supplied for the bearing escapes is formed between the cap 41 and the roller main body 30, and the caps 41 and 42 and the rotating roller 21a are brought into contact with each other.

  The outer diameter of the shaft 35 is slightly smaller than the inner diameter of the bush 33 of the rotating roller 21a to create a gap, thereby forming a gas layer in a cylindrical shape between the outer surface of the shaft and the inner surface of the bush to constitute a bearing. . For example, the gap is 0.05 mm to 0.10 mm.

  The gas introduction pipe 23 is connected to the base of the shaft 35, and, for example, compressed air from the high-pressure gas supply source 24 is injected into the gap from the gas injection hole 37 through the gas flow path 36 of the shaft and functions as a gas bearing.

  The bracket 38 is fixed to the base 45, and forms a roller conveyor 20 in parallel as a plurality of rotating roller devices.

  The roller body 30 is made of polytetrafluoroethylene (PTFE), which is a fluororesin, as a heat-resistant resin, and is molded by mixing 10 to 20% by volume of graphite powder as a filler. The bush 33 is formed of stainless steel, for example, SUS304, and the roller main body 30 has elasticity, so that the bush 33 is fitted so as to elastically adhere to the shaft hole wall. Since the melting point of the resin is 327 ° C., it can withstand heating at about 300 ° C. This resin has a low coefficient of friction and is less likely to cause mechanical damage to the surface of the glass tube that comes into contact with the filled graphite powder by conveyance. The opening angle of the V-shaped annular groove is selected depending on the diameter of the glass tube to be conveyed, but is, for example, 90 to 135 degrees.

  Further, the heat received from the hot glass tube G1 becomes a cooling fin in the bush 33 located at the bottom of the groove, and can be quickly dissipated and cooled by the entire bearing. When the bush is not provided, the vicinity of the contact portion of the glass tube It is possible to prevent overheating due to heat retention. The shaft is made of similar stainless steel.

  In FIG. 1, the glass tube G0 drawn from the muffle furnace 11 has a viscosity and is in a state of plastic deformation, and as it hangs down, it is drawn while being cooled by the outside air and solidifies into a glass tube G1 having a predetermined diameter. . The glass tube heated to about 500 ° C. near the muffle furnace reaches about 300 ° C. when it reaches the horizontal position of the conveyor. A graphite rotating roller device is used for a glass tube of 300 ° C. to 500 ° C., and the rotating roller device of this embodiment is used for a glass tube having a temperature of about 300 ° C. or less.

  As an example, when a 4 mmφ glass tube is formed, the tube drawing speed is 1.3 to 2.6 m / s. The length of the rotating roller 21a applied at this time is 50 mm, the maximum diameter of the roller body is 50 mmφ, The outer diameter of the bottom of the annular groove 31 was 32.5 mmφ, the inner diameter of the bush 33 was 14.9 mmφ, the outer diameter of the shaft 35 was 15.0 mmφ, and air of 2 atm was supplied from the high-pressure gas supply source 24.

  The service life of the rotating roller 21a due to contact wear with the glass tube is an average of 8500 hours in use time, which is four times that of a rotating roller device having only a heat-resistant resin without a bush.

(Embodiment 2)
In this embodiment, as shown in FIG. 3 (a), a spiral protrusion 50 is formed on the surface of the bush 33, while a spiral groove 51 is formed on the inner wall of the shaft hole 32 of the roller body. It is worn. In addition, the part of the same code | symbol as Embodiment 1 shows a component similarly. By forming the spiral convex portion 50, the contact area between both the members 30 and 33 is increased, and the heat of the roller body can be easily captured, so that heat dissipation can be increased.

  Furthermore, since the thermal expansion of the resin roller body 30 is larger than that of the metal, the contact tends to loosen due to heating during operation, but this tendency can be reduced by the convex portion 51 even when the thermal expansion difference is large. .

(Embodiment 3)
In the present embodiment, an intermediate metal tube 52 having an intermediate coefficient of thermal expansion smaller than that of the roller body and larger than that of the bush is interposed between the roller body 30 and the bush 33. As an example, when the bush 33 is made of stainless steel, the intermediate metal tube 52 is made of metallic aluminum. Heat-resistant polyamide-imide resin 31.0 × 10 ⁶ / ° C., the aluminum is 23 × 10 ⁶ / ℃, a 17.3 × 10 ⁶ / ℃ stainless steel SUS304, to relax the difference in the expansion coefficients of the roller body and the bushing. Since the intermediate metal tube 52 is aluminum which is a heat conductive metal, heat dissipation of the roller body is further advantageous.

  Although the present invention has been described above with reference to the embodiments, the annular groove of the roller main body is not limited to the V-shaped cross section, but can be applied to a roller formed with a plurality of grooves such as a W-shaped cross section.

  Further, the glass tube forming apparatus is not limited to the dunner method, and can be applied to devices formed by other methods such as a bellows method.

Schematic explaining one Embodiment of this invention. Sectional drawing of the rotating roller apparatus of one Embodiment of this invention. (A) and (b) are the cross-sectional schematic diagrams explaining other embodiment of this invention.

Explanation of symbols

11: Muffle furnace 20: Roller conveyor 21: Rotating roller device 21a: Rotating roller 23: Gas introduction pipe 24: High pressure gas supply source 30: Roller body 31: Annular groove 32: Shaft hole 33: Bush 35: Shaft 36: Gas flow Path 37: Gas injection hole 38: Bracket 41, 42: Cap

Claims (4)

A rotation comprising a shaft that forms a gas bearing by forming a vent hole for injecting gas on the side surface, and a rotating roller that is inserted into the shaft and has an annular groove that guides the glass body and rotates around the shaft. A roller device,
The rotating roller has a roller body formed of a heat-resistant resin with the annular groove formed on the outer surface and the rotating shaft side as an axial hole;
It comprises a bush of a metal tube that is inserted so that the outer surface is in close contact with the inner surface of the shaft hole of the roller body and an air layer is formed between the inner surface and the side surface of the shaft to constitute a bearing. A rotating roller device for conveying a glass body.   The rotation roller device for conveying a glass body according to claim 1, wherein the roller body and the bush are screwed together.   The rotation for conveying a glass body according to claim 1, wherein an intermediate metal tube having an intermediate coefficient of thermal expansion smaller than that of the roller body and larger than that of the bush is interposed between the roller body and the bush. Roller device.   A roller conveyor comprising a plurality of the rotating roller devices according to claim 1 arranged in a line.

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