JP4183108B2 - In-furnace transport roller with ring and method for manufacturing the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an in-furnace transport roller used for transport of an object to be heated in a roller hearth kiln or the like.
[0002]
[Prior art]
In recent years, a roller made of a ceramic material having excellent wear resistance, heat resistance, light weight and the like has attracted attention as an in-furnace transfer roller used in a continuous heating furnace such as a roller hearth kiln. This type of roller is required to have high shape accuracy. For example, in a roller having a length of about 2400 mm used in a wide roller hearth kiln for baking a glass substrate, the amount of warpage a of the roller shown in FIG. 3 is within 0.5 mm. It is preferable that
[0003]
When this warp amount a is large, (1) the peripheral speed at the maximum warp position of the roller is faster than other parts, and contact with the setter becomes point contact, which causes dust generation due to friction with the setter. (2) Since the peripheral speed of rotation differs in the width direction in the furnace, the heated body meanders. (3) The heated body moves up and down during transportation, and the impact caused by the vibration causes damage to the heated body. This leads to problems such as
[0004]
In general, a ceramic-made in-furnace transport roller is manufactured by firing a hollow shaft-shaped formed body obtained by extrusion molding. However, the amount of warping a at the end of firing is a roller in the existing technology. It is about 0.1% of the length. That is, with a roller having a length of 2400 mm, a warp of about 2.4 mm is generated, which greatly exceeds the preferable range of 0.5 mm or less. Conventionally, with a long roller, the above-described (1) to (3) Had a problem.
[0005]
[Problems to be solved by the invention]
A high-hardness and dense ceramic sintered body used for in-furnace transport rollers does not have good workability. Therefore, if the roller surface is ground to correct warpage, a large amount of processing is required. Since the processing cost is high and the strength is lowered, it has been considered that polishing is impossible.
[0006]
The present invention has been made in view of such conventional circumstances, and the object of the present invention is a ceramic in-furnace transport roller capable of obtaining a required shape accuracy with a small amount of processing and its manufacture. It is to provide a method.
[0007]
[Means for Solving the Problems]
According to the present invention, a plurality of rings made of the same material are integrally joined at a predetermined interval to a roller shaft made of a Si-SiC sintered body containing silicon carbide and silicon as constituent components. An in-furnace transport roller with a ring is provided.
[0008]
Further, according to the present invention, a shaft-shaped molded body and a plurality of ring-shaped molded bodies were separately molded using a molding raw material prepared using silicon carbide powder and carbon powder as main raw materials. A plurality of ring-shaped molded bodies are inserted into the shaft-shaped molded body and bonded and fixed at predetermined intervals, and then this is impregnated with metal silicon in a reduced-pressure inert gas atmosphere or vacuum in which metal silicon is present. A method for producing a roller for transporting in a furnace with a ring, characterized in that a roller sintered body with a ring is obtained by firing, and the required shape accuracy is obtained by polishing the surface of the ring of the sintered body. Provided.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a perspective view showing an example of an embodiment of an in-furnace transport roller according to the present invention, and FIG. 2 is a cross-sectional view taken along line AA of FIG. In the in-furnace transport roller 1 of the present invention, a plurality of rings 5 made of the same material are arranged at predetermined intervals on a roller shaft 3 made of a Si—SiC sintered body containing silicon carbide and silicon as constituent components. Are integrally joined. The ring 5 is joined to the roller shaft 3 and polished after joining so that the central axis of the ring 5 is coaxial with the central axis of the roller shaft 3 when the roller 1 rotates.
[0010]
The in-furnace transport roller 1 with a ring rotates in a state where only the surface of the ring 5 is in contact with a setter on which the heated body is placed, and transports the heated body and the setter. For this reason, in the manufacturing process of a roller, when it is going to correct the curvature at the time of completion | finish of baking, the polishing process for the correction should just be given only to the surface of the ring 5 which contacts a setter, and there is little processing amount Thus, the required shape accuracy can be obtained.
[0011]
In addition, as a configuration of the in-furnace transport roller having such a ring, in addition to an integrated structure as in the present invention, a structure in which a separate roller shaft and a ring are fitted may be considered. In that case, in order to ensure the required shape accuracy, in addition to the processing accuracy of the shape processing as described above, the fitting accuracy between the roller shaft and the ring, the displacement and looseness of the ring, and thermal expansion are also considered. There is a need to. On the other hand, in the roller of the present invention, since the roller shaft 3 and the ring 5 are integrated, it is not necessary to consider problems other than the processing accuracy when ensuring the required shape accuracy.
[0012]
The Si—SiC sintered body forming the roller of the present invention is a material in which a silicon carbide material is used as a base material, and metal silicon is infiltrated and impregnated into pores thereof, and includes silicon carbide and carbon as its composition. Specifically, those containing 50 to 99.5% by weight of silicon carbide and 0.5 to 50% by weight of silicon are preferable from the viewpoint of strength, thermal shock resistance and the like.
[0013]
The Si-SiC sintered body is obtained by firing a molded body made using a molding raw material mainly composed of silicon carbide powder and carbon powder while impregnating metal silicon. Since the formed metal silicon has a function as a bonding material, when the above-described firing is performed by combining separately formed roller shafts and rings, the two are firmly integrated by the action of the metal silicon. In addition, in the formation process, the Si-SiC-based sintered body not only works suitably for the integration of the roller shaft and the ring, but also has excellent strength, oxidation resistance, etc. It is very suitable.
[0014]
Next, the manufacturing method of the roller of this invention is demonstrated. FIG. 4 is a flowchart showing an example of a roller manufacturing method according to the present invention. In manufacturing the roller as described above, first, a raw material for molding is prepared using silicon carbide powder and carbon powder as main raw materials. That is, a predetermined amount of silicon carbide powder and carbon powder are mixed, and an organic binder such as phenol or methylcellulose and water are added to the mixed powder and kneaded to obtain a forming raw material.
[0015]
Next, using this forming raw material, a shaft-shaped molded body and a plurality of ring-shaped molded bodies are molded separately. The molding is performed by extruding a molding raw material into a cylindrical shape by extrusion molding and cutting it at a predetermined length (thickness), thereby producing a desired shaft-shaped molded body and ring-shaped molded body, respectively.
[0016]
Next, after drying each molded body obtained, a plurality of ring-shaped molded bodies are inserted into the shaft-shaped molded body and bonded and fixed at a predetermined interval. A slurry for bonding obtained by adding phenol or methyl cellulose as an organic binder to a mixture of silicon carbide fine particles and carbon fine particles and further adding water in a paste form can be suitably used.
[0017]
After the bonding, this is baked while impregnating metal silicon in a reduced-pressure inert gas atmosphere or vacuum in which metal silicon is present. The firing temperature is preferably in the range of 1350-2500 ° C. By this firing, molten metal silicon is impregnated in the molded body, reacts with the carbon powder in the molded body to turn it into silicon carbide, and fills in the pores to be densified. Further, the metal silicon also acts as a bonding material, and integrates the shaft-shaped molded body and the ring-shaped molded body more firmly.
[0018]
The roller sintered body with a ring of Si-SiC obtained in this way is subjected to surface finishing by sandblasting, and then the surface of the ring is polished to correct the warpage of the roller to obtain the required shape accuracy. . Specifically, when the roller is rotated, the ring is polished so that the center axis of each ring is coaxial with the center axis of the roller axis and the outer surface of each ring forms the same plane. As described above, in this roller with a ring, the required shape accuracy can be obtained by polishing only the surface of the ring, so that the outer diameter accuracy is greatly improved at a lower cost than conventional rollers. be able to.
[0019]
In the present invention, the size of the roller, the number of rings, and the arrangement interval are appropriately determined depending on the size / structure of the furnace in which the roller is used, the heated object to be transported, and the like.
[0020]
【Example】
EXAMPLES Hereinafter, although this invention is demonstrated further in detail based on an Example, this invention is not limited to these Examples.
[0021]
Mixing 55% by weight of silicon carbide powder as an aggregate with a maximum particle size of 150 μm, 25% by weight of fine silicon carbide powder with an average particle size of 20 μm, 15% by weight of fine silicon carbide powder with an average particle size of 10 μm and 5% by weight of black smoke powder Then, 4% by weight of methylcellulose was added externally as a binder, water was further added, and the mixture was kneaded for 30 minutes to obtain a molding clay.
[0022]
A continuous extruder was used for molding, and the clay was molded into a cylindrical shape with a pressure during extrusion of 30 kgf / cm ² . After extrusion molding, it was dried at 60 ° C. for 15 hours to obtain a cylindrical molded body having a predetermined inner diameter and outer diameter. This molded body was cut into predetermined dimensions to produce a shaft-shaped molded body that becomes the shaft of the roller and a ring-shaped molded body that becomes the ring. In addition, in order to adhere | attach on the whole surface, maintaining the roundness after adhesion | attachment, the difference between the outer diameter of a shaft-shaped molded object and the internal diameter of a ring-shaped molded object was made into about 0.5-1 mm.
[0023]
95% by weight of silicon carbide fine powder with an average particle size of 10 μm and 5% by weight of black smoke powder are mixed, and 2% by weight of methylcellulose is added as an external binder to this, and water is further added to knead until a paste is formed. Thus, an adhesive material (adhesive) was obtained. This adhesive was applied to the ring attachment planned position of the shaft-shaped molded body, and the ring-shaped molded body was inserted to that position and rotated a little so that the inner surface of the ring and the tube were completely brought into close contact with the adhesive.
[0024]
After bonding, the film was dried at 60 ° C. for 12 hours or more to obtain a joined body of a shaft-shaped body and a ring-shaped body. The joined body was fired in a vacuum containing metal silicon at 1650 ° C. while impregnating the metal silicon. The sintered body thus obtained was polished on the ring surface until the required shape accuracy was obtained, and the in-furnace transport roller with a ring was completed.
[0025]
【The invention's effect】
As described above, the in-furnace transport roller of the present invention is processed only on the surface of the ring that comes into contact with the setter during use in correcting the warpage at the end of firing in the manufacturing process and obtaining the required shape accuracy. As a result, it is possible to provide a roller with a low processing cost. In addition, since the roller shaft and the ring are integrated, in order to ensure the required shape accuracy, consideration should be given to problems other than the processing accuracy such as the fitting accuracy between the roller shaft and the ring, misalignment and loosening of the ring, and thermal expansion. There is no need. Furthermore, according to the manufacturing method of the present invention, it is possible to perform a polishing process for correcting the warpage of the roller after firing, and to obtain the required shape accuracy with a small processing amount.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an example of an embodiment of an in-furnace transport roller with a ring according to the present invention.
FIG. 2 is a cross-sectional view taken along the line AA of FIG.
FIG. 3 is an explanatory diagram showing a warping amount of a roller.
FIG. 4 is a flowchart showing an example of a method for producing a furnace roller with a ring according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Roller for conveyance in a furnace with a ring, 3 ... Roller shaft, 5 ... Ring.

Claims (3)

A plurality of rings made of the same material are integrally joined at a predetermined interval to a roller shaft made of a Si-SiC sintered body containing silicon carbide and silicon as constituent components. In-furnace roller with a ring. The in-furnace transport roller according to claim 1, wherein a central axis of each of the rings is coaxial with a central axis of the roller shaft when the roller rotates. A shaft-shaped molded body and a plurality of ring-shaped molded bodies are separately molded using a molding raw material prepared using silicon carbide powder and carbon powder as main raw materials, and a plurality of ring-shaped molded bodies are obtained. After the ring-shaped formed body is inserted and bonded and fixed at predetermined intervals, this is fired while impregnating metal silicon in a reduced-pressure inert gas atmosphere or vacuum in which metal silicon is present, so that a roller with a ring is fired. A method for producing an in-furnace transport roller with a ring, wherein a sintered body is obtained, and a necessary shape accuracy is obtained by polishing the surface of the ring of the sintered body.

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