JPH10167444A - Carrying roller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a carrying roller, which does not allow a cylindrical ceramic member to turn idle around a shaft, and can prevent the cylindrical ceramic member from being damaged when the roller is deflected due to the weight of articles on carrier even when it is used under high temperatures, or when a metallic shaft is elongated in the axial direction due to thermal expansion and even when a gap is created in between the cylindrical ceramic members. SOLUTION: A plural number of relatively uniform cylindrical ceramic members 3 are fitted in to a metallic shaft 2 in such a way that the end faces of the adjacent cylindrical ceramic members 3 come into contact with each other so as to allow the roller 1 for a carrier to be formed up, the cross section of the shaft 2 is formed into a shape out of which one or more than two of an inferior arc portion are cut out when a line segment connecting two points over the circumference of its circle is drawn, and concurrently the cross sectional shape of the inner circumference of the cylindrical ceramic member 3 is made similar to the cross sectional shape of the shaft 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuous casting slab; a transport roller for transporting a high-temperature and heavy-weight material such as a rolled material such as a rod, a tube, and a plate.

[0002]

2. Description of the Related Art Conventionally, in the steelmaking and steelmaking industries, continuous casting slabs; for transporting high-temperature and heavy-weight materials such as rolled materials such as rods, tubes, and plates, have been made of metal made of heat-resistant steel, iron-based alloy, or the like. Rollers were used, but metal rollers have low heat resistance, and the surface condition deteriorates due to wear on the roller surface or scale burning of the conveyed steel material, so maintenance such as polishing of the roller surface is required. This operation had to be performed frequently, and this operation was extremely dangerous because the operation was performed without stopping the line in terms of operating efficiency.

For this reason, in recent years, a conveying roller configured by fitting a cylindrical ceramic member to a metal shaft has been used.
Japanese Patent Application Laid-Open No. 196154/1992 discloses a conveying roller formed by fitting a cylindrical ceramic member integrally formed on a steel shaft.

However, in this transport roller, since the ceramic member to be fitted to the shaft is integrally formed, the size of the ceramic member becomes large and it is difficult to manufacture the roller. However, since the difference in thermal expansion cannot be absorbed and the concentration of stress during transportation cannot be reduced, there is a drawback that durability is low and breakage occurs easily.

In order to solve such a drawback, recently, a conveying roller in which a plurality of cylindrical ceramic members are fitted to a metal shaft without using a ceramic member integrally is used. And, for example,
In Japanese Patent Application Laid-Open No. 1-55409, as shown in FIG.
A plurality of cylindrical ceramic members 3 made of a sintered body of ceramic such as silicon nitride, a composite material of ceramic and metal, etc.
Is fitted to a metal shaft 2 and a transfer roller 1 in which a dissimilar material such as metal is interposed between the shaft 2 and the cylindrical ceramic member 3 in order to absorb a difference in thermal expansion between the two. Is disclosed.

In Japanese Patent Publication No. 62-26861, a plurality of cylindrical ceramic members are mounted on a metal shaft.
A conveying roller is disclosed in which a fitting member is fitted via a stress relieving member, and a metal annular fixing member is fitted between the ceramic members. The reason why the stress relaxation member is used is to prevent the cylindrical ceramic member from being damaged by expansion of the metal shaft when used at a high temperature because the coefficient of thermal expansion of ceramic is smaller than that of metal. .

Japanese Unexamined Patent Publication (Kokai) No. 63-160739 discloses that, as shown in FIG. 5B, a ceramic roller body 8 made of silicon nitride and an end roller body 13 made of carbon steel are provided.
The metal shaft 2 is arranged so that the end roller body 13 made of carbon steel is positioned on both sides of the ceramic roller body 8 made of silicon nitride.
And a conveying roller 1 fastened by a screw fastening member.

[0008]

However, in the conveying roller 1 disclosed in Japanese Patent Application Laid-Open No. 61-55409, the cross section of the outer circumference of the metal shaft and the inner circumference of the cylindrical ceramic member is circular. For this reason, there is a problem that the cylindrical ceramic member idles. In addition, absorbing the difference in thermal expansion between the cylindrical ceramic member 2 and the metal shaft 1 by using the stress relaxation member 12 increases the number of parts, and thus complicates the manufacturing process and increases the cost. There was a problem. Furthermore, when the roller bends, the edges of the end face of the cylindrical ceramic member 3 may collide with each other, and the portion may be chipped or broken.

[0009] Further, in the transfer roller disclosed in Japanese Patent Publication No. Sho 62-26861, a stress relieving material is used to absorb the difference in thermal expansion between the cylindrical ceramic member and the metal shaft. However, there is a problem that the number of parts is increased, which complicates the manufacturing process and increases the cost. Further, in the case of use at a low temperature, there is a problem that the cylindrical ceramic member idles around the axis.

[0010] Also, in the conveying roller 1 disclosed in JP-A-63-160739, the ceramic roller body 8 and the end roller body 13 idle around the shaft when used at low temperatures. In addition, at high temperatures, these members may be damaged due to expansion of the metal shaft 2, and the ceramic roller body 8 and the end roller body 13 may be made of silicon nitride. Since both of them are made of carbon steel and have different dimensions, there is a problem that the number of parts is increased, and the manufacturing process becomes complicated and the cost is increased.

The present invention has been made in view of such a situation, and an object of the present invention is to make it possible for a cylindrical ceramic member to be used even when a gap is formed between the cylindrical ceramic member and a metal shaft. An object of the present invention is to provide a transport roller that does not run around the shaft, is easy to assemble, contributes to simplification of a manufacturing process, and does not cause damage to a transported object. In addition, even when used at high temperatures, the expansion of the metal shaft does not damage the cylindrical member, and the number of parts is small.
Another object of the present invention is to provide a transport roller that can contribute to a reduction in manufacturing cost. Furthermore, the cylindrical ceramic member may be damaged when the roller is bent due to the weight of the conveyed object or when the metal shaft extends in the axial direction due to thermal expansion and a gap is formed between the cylindrical ceramic members. Another object of the present invention is to provide a transport roller that does not need to be used.

[0012]

That is, according to the present invention, a plurality of mutually uniform cylindrical ceramic members are fitted to a metal shaft such that end faces of adjacent cylindrical ceramic members are in contact with each other. A conveying roller comprising: a cross section of the shaft having a shape in which one or two or more subarc portions are cut out when a line segment connecting two points on a circle is drawn on a circle; A conveying roller is provided in which the cross-sectional shape of the inner periphery of the cylindrical ceramic member is similar to the cross-sectional shape of the shaft.

In the above-described transport roller, the dimensional ratio of the cross section of the shaft when thermally expanded at the maximum use temperature to the cross section of the inner periphery of the cylindrical ceramic member is 95: 100 to 1: 1.
It is preferred that

Further, it is preferable that the transporting roller is one in which the edges of both end faces of each cylindrical ceramic member are smoothly chamfered.

[0015] In the transport roller, the cylindrical ceramic member is preferably made of one or more materials selected from the group consisting of silicon nitride, sialon, and silicon carbide.

[0016] Further, the above-mentioned conveying roller may have open pores communicating the inner peripheral side and the outer peripheral side of the cylindrical ceramic member. In this case, the diameter of the above-mentioned open pores is 20 mm.
It is preferably not more than μm.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION In the conveying roller of the present invention, as shown in FIG. 1, the cross section of the shaft 2 is one or two when a line segment connecting two points on the circumference is drawn on a circle. It has a shape in which the above-mentioned inferior arc is cut out, and since the cross-sectional shape of the inner periphery of the cylindrical ceramic member 3 is similar to the cross-sectional shape of the shaft, the cylindrical ceramic member 3 and metal Shaft 2
The cylindrical ceramic member 3 does not idle around the shaft 2 even when a gap is generated between the cylindrical ceramic member 3 and the cylindrical ceramic member 3.

The two points on the circumference are preferably provided such that the central angle formed by the two points and the center point of the circle is 30 ° to 120 °. If the angle is less than 30 °, the effect of preventing idling cannot be obtained.

There is no limitation on the number of notched subarc portions, but it is preferable that the number is one or two from the viewpoint of simplifying the manufacturing process.

In the transport roller of the present invention, the plurality of cylindrical ceramic members 3 fitted to the metal shaft 2 are uniform with each other, that is, have the same shape, size and material. It can be manufactured at low cost, and the assembling of the transport roller 1 becomes easy, so that the manufacturing process can be simplified.

The cylindrical ceramic member 3 is fitted to the metal shaft 2 such that the end faces of the adjacent cylindrical ceramic members come into contact with each other. Therefore, since the gap between the cylindrical ceramic members is small, Even when the steel material to be conveyed is softened by heating, the conveyed material is not damaged.

In the present invention, by determining the dimensions of the cylindrical ceramic member 3 and the metal shaft 2 in consideration of the coefficient of thermal expansion thereof, the cylindrical ceramic member 3 can be formed at the maximum use temperature of the transport roller 1. 3 is 95: 100 to 1: 1.
When the metal shaft 2 expands at a high temperature without using a stress relaxation member, the cylindrical member 3
Can be prevented from being damaged, and the manufacturing cost can be reduced by reducing the number of parts. Therefore, at a low temperature, a gap is formed between the cylindrical ceramic member 3 and the metal shaft 2. However, due to the presence of the notch, the cylindrical ceramic member 3 can be prevented from idling. At a high temperature, even if the metal shaft 2 expands, it is possible to prevent the cylindrical ceramic member 3 from being damaged.

In the transport roller of the present invention,
As shown in FIG. 2, if the edges of both end faces of the cylindrical ceramic member 3 are gently chamfered, the edges of the end faces of the cylindrical ceramic member 3 can be connected even when the roller 1 bends. Crashed, that part was missing,
Does not break. In addition, the gentle chamfering is performed by chamfering a corner portion formed by the end surface 6 and the outer peripheral surface 7 of the cylindrical ceramic member 3 to 45 ° or less,
In addition, the corner formed by the chamfered portion and the outer peripheral surface 7 is rounded so that the chamfered portion smoothly transitions to the outer peripheral surface 7 or the end surface 6 of the cylindrical ceramic member 3 and the outer peripheral surface 7 Means that a rounded portion having a chord oriented at an angle of 45 ° or less with respect to the outer peripheral surface 7 is formed at the corner formed by the above so that the end surface 6 smoothly transitions to the outer peripheral surface 7.

In the transport roller of the present invention, the cylindrical ceramic member is preferably made of one or more materials selected from the group consisting of silicon nitride, sialon and silicon carbide, but is preferably made of silicon nitride. Is more preferred. This is because silicon nitride has particularly poor reactivity with steel even at high temperatures, so that scale does not adhere to the roller surface and can be used without maintenance.

The transport roller of the present invention may have open pores communicating the inner peripheral side and the outer peripheral side of the cylindrical ceramic member. In this case, the diameter of the open pores is 20 μm or less. Is preferred. If the diameter of the open pores exceeds 20 μm, the steel material being conveyed enters the open pores and adheres, and the steel material is easily damaged by being built up. The diameter of the open pore is more preferably 10 μm or less.

The cylindrical ceramic member used for the transport roller of the present invention is manufactured, for example, as follows.

First, a silicon nitride raw material dried and granulated by a spray drier is filled in a molding die composed of a cored bar and a rubber die disposed outside the cored bar, and a pressure of, for example, 4 t / cm ² is applied by a hydrostatic press. Press molding. The core has a diameter of, for example, 120 m, as shown in FIG.
m, width 9 mm on the outer circumference of S45C steel material 150 mm in length
The one having a two-plane width of 5 mm is used. Also, silicon nitride raw materials include MgO, CeO, SrO ₂ , ZrO ₂ , Al
_A sintering aid containing ₂ O ₃ , Y ₂ O ₃ , Yb ₂ O _3, etc. and a binder may be added.

The outer periphery and both end surfaces of the obtained molded body are NC
After processing with a lathe, firing is performed in an electric furnace in a nitrogen atmosphere, for example, at 1650 ° C. for 2 hours to obtain a fired silicon nitride body.

Next, both ends and an outer peripheral portion of the obtained fired body are subjected to a grinding process, for example, an outer diameter is set to 150 mm, an inner diameter is set to 95 mm, and a length is set to 100 mm. Is chamfered with R50 mm and width 20 mm to obtain a cylindrical ceramic member 3 as shown in FIG. The surface roughness of the outer peripheral surface 7 is, for example, R
_{max is} 3.2 μm, and the inner peripheral surface 9 is left as a fired surface. The grinding is performed using, for example, a cylindrical grinder, and a # 400 resin diamond grindstone is used as a grindstone, for example.

The transport roller of the present invention is manufactured, for example, as follows.

As the axis of the transport roller, for example,
1600mm length, 94mm diameter, 75mm width on the outer circumference
A shaft made of S55C having the two surface widths described above is used. Further, it is preferable to provide a bearing portion in a region that is constant from both end surfaces of the shaft, for example, a region of 250 mm.

As shown in FIG. 4, for example, three cylindrical ceramic members 3 and 10 are fitted to the shaft 2, and then, from both ends of the shaft 2, a flange 10 for stopping the flow of steel material.
The fixing roller 11 made of S55C provided with is fitted, and the shaft 2 and the fixing sleeve 11 are welded to obtain the transport roller 1 of the present invention.

[0033]

Hereinafter, the present invention will be described in more detail with reference to the illustrated embodiments, but the present invention is not limited to these embodiments.

Example 1 A steel material was transported using the transport roller of the present invention, and its performance was examined. The roller conveyor shown in FIG. 4 is equipped with five transfer rollers shown in FIG. 4 and a steel billet having a length of 10 m and a weight of 1 t is heated to 1300 ° C. by an electric heater at a speed of 2 to 3 m / sec. Transported. The state of the rollers transported, the surface condition of the transported articles, and the state of the rollers after operating the roller conveyor for one month were observed.

(Comparative Example 1) A steel material was conveyed under the same conditions as in Example 1 except that the roller attached to the roller conveyor was a roller made of heat-resistant steel (SUH), and the state of conveyance by the roller was used. The surface condition of the conveyed material and the state of the roller after the roller conveyor was operated for one month were observed.

No matter which of the heat-resistant steel roller and the transfer roller of the present invention was used, idle rotation did not occur and good transfer could be performed. However, on the outer peripheral surface of the heat-resistant steel roller, scale oxidized steel material is seized,
Many irregularities were generated on the surface, and the surface of the steel material was also damaged due to the irregularities on the roller surface.

On the other hand, when the transport roller of the present invention was used, no adhesion of scale was observed, the surface of the roller was smooth, and no scratch was generated on the steel material. In addition, the cylindrical ceramic member was not damaged due to the expansion of the metal shaft or the deflection of the roller due to the weight of the steel material.

[0038]

According to the transport roller of the present invention,
The cross section of the shaft has a shape in which one or two or more inferior arc parts are cut out when a line segment connecting two points on the circumference is drawn on a circle,
Further, since the cross-sectional shape of the inner periphery of the cylindrical ceramic member and the cross-sectional shape of the shaft are similar, even when a gap is generated between the cylindrical ceramic member and the metal shaft,
The cylindrical ceramic member does not spin around the axis.

Further, since the plurality of cylindrical ceramic members fitted to the shaft are uniform to each other, it is easy to assemble the rollers and to simplify the manufacturing process.

Further, since the end faces of the adjacent cylindrical ceramic members are fitted to the metal shaft so that the end faces come into contact with each other, no damage occurs to the conveyed object.

If the dimensional ratio between the cross section of the shaft and the cross section of the inner periphery of the cylindrical ceramic member at the time of thermal expansion at the maximum use temperature is 95: 100 to 1: 1, high temperature Even when used below, the expansion of the shaft does not damage the cylindrical member, and the number of parts is reduced, which can contribute to a reduction in manufacturing cost.

Furthermore, if the edges of both end surfaces of the cylindrical ceramic member are gently chamfered, the cylindrical ceramic member will not be damaged even when the roller is bent due to the weight of the conveyed object or the like.

[Brief description of the drawings]

FIG. 1 shows an example of a transport roller of the present invention (a).
It is a front view and (b) sectional view on the AA 'line.

FIG. 2 is a front view showing another example of the transport roller of the present invention.

3A is a perspective view showing an example of a core metal used for molding a cylindrical ceramic member, and FIG. 3B is a perspective view showing an example of a cylindrical ceramic member used for a transport roller of the present invention.

4A is a perspective view showing still another example of the transport roller of the present invention, FIG. 4B is a cross-sectional view taken along line AA ′, and FIG.
It is a sectional view taken on the line B '.

FIG. 5A is a perspective view showing one example of a conventional transport roller, and FIG. 5B is a perspective view showing another example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Conveying roller, 2 ... Metal shaft, 3 ... Cylindrical ceramic member, 4 ... Stopper, 5 ... Chamfering, 6 ...
An end surface of a cylindrical ceramic member, 7 ... an outer peripheral surface of a cylindrical ceramic member, 8 ... a ceramic roller body, 9 ... an inner peripheral surface of a cylindrical ceramic member, 10 ... brim removal, 11 ...・ ・
Fixing sleeve, 12: stress relaxation member, 13: end roller body.

Claims (5)

[Claims] 1. A transport roller comprising a plurality of uniform cylindrical ceramic members fitted to a metal shaft such that end faces of adjacent cylindrical ceramic members are in contact with each other. The cross section has a shape in which one or more subarc portions are cut out when a line segment connecting two points on the circumference is drawn on a circle, and the shape of the cross section of the inner circumference of the cylindrical ceramic member is And a cross-sectional shape of the shaft is similar. 2. The dimensional ratio of a cross section of the shaft when thermally expanded at a maximum use temperature to a cross section of an inner periphery of the cylindrical ceramic member is 95: 100 to 1: 1. Transport rollers. 3. The transporting roller according to claim 1, wherein edges of both end surfaces of the cylindrical ceramic member are gently chamfered. 4. The transport roller according to claim 1, wherein said cylindrical ceramic member is made of one or more materials selected from the group consisting of silicon nitride, sialon and silicon carbide. 5. An open pore communicating between an inner peripheral side and an outer peripheral side of the cylindrical ceramic member, wherein the diameter of the open pore is 20 μm.
The transporting roller according to claim 1, wherein m is not more than m.