JP2002145439A - Heat-resistant combined roller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a ceramics roller 12 from generating damage caused by a tightening pressure in a combined roller 10 in which the ceramics roller 12 engaged on a support shaft 11 made of metal is tightened and clamped by a receiving part 11b provided on one end of the support shaft 11 and a tightening nut member 13 made of metal and thread-mounted to the other end thereof. SOLUTION: A ratio of an axial width L and a radial thickness ΔD (thickness ΔD/width L) of a tightening nut member 13 is set to ΔD/L<=1.5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a heat-resistant composite roller for use as a roller for a hot rolling line in various steps of a hot rolling line.

[0002]

2. Description of the Related Art Rollers for a hot rolling line are required to have extremely high heat resistance and abrasion resistance. Generally, such rollers are made of heat-resistant steel or iron-based alloy. Metal rollers are used. However,
The heat-resistant metal roller still cannot sufficiently cope with the heat resistance required in the hot rolling line, and, due to the seizure of the roller itself and the material to be rolled, Many fine cracks are generated on the surface of the roller, and the roller surface is damaged at an early stage.

To cope with this, Japanese Patent Laid-Open Publication No. 63-1607
No. 39 proposes a composite roller in which a portion to be contacted by a material to be rolled is formed by a ceramic roller. The composite roller is a metal support shaft, a pair of left and right metal end rollers fitted on the support shaft, and a ceramic fitted on the support shaft and positioned between these end rollers. These three rollers are sandwiched and fixed by a fastening action between a flange provided at one end of the support shaft and a fastening nut member screwed to the other end of the support shaft. Is what it is.

According to the composite roller, since the portion requiring extremely high heat resistance and seizure prevention ability is constituted by a ceramic roller, the heat resistance required in a hot rolling line is required. To prevent the roller itself and the roller and the material to be rolled from seizing to prevent the roller surface from being damaged, and to maintain the roller surface in a good condition for a long period of time. It has the effect that can be done.

However, in the composite roller, a component made of two types of materials having greatly different coefficients of thermal expansion, a metal support shaft and metal end rollers and a ceramic central roller, is used. Therefore, the temperature rise during actual operation causes a large difference in thermal expansion between these components, loosening of the fastening state of each roller, causing idling of each roller, and Due to the thermal expansion, a tensile stress may be generated on the inner diameter side of the center roller made of ceramic, and the center roller may be damaged.

In view of these problems, the present applicant has proposed a composite roller capable of addressing these problems in Japanese Patent Application Laid-Open No. Hei 10-218337, which is a prior application of the present applicant. The composite roller includes a metal support shaft and a ceramic roller fitted on the support shaft.
By a receiving portion provided at one end of the support shaft and a metal fastening nut member screwed to the other end of the support shaft, the metal member is fastened and clamped while being heated to a temperature higher than the actual operating temperature. is there.

In the composite roller, a ceramic roller (hereinafter sometimes referred to as a ceramic roller) is screwed to a receiving portion provided at one end of the support shaft and to the other end of the support shaft. With the fastening nut member of the above, the structure is adopted in which the composite roller is fastened and clamped in a state heated above the actual operating temperature of the composite roller, so that the temperature rise during the actual operation of the composite roller causes thermal expansion. Even when the ceramic roller is not loosened, the ceramic roller can be prevented from spinning without loosening, and the generation of tensile stress on the inner diameter side of the ceramic roller can be suppressed, thereby preventing the ceramic roller from being damaged. Is played.

[0008]

As described above, the composite roller proposed in the latter publication, which is the earlier application of the present applicant, has the problems of the composite roller proposed in the former publication. In this respect, it can be recognized that the composite roller has excellent characteristics.

The present inventor has studied the composite roller according to the prior application of the present applicant in more detail, and as a result, in the composite roller, the fastening force of the fastening nut member and the fastening nut member and the support shaft have been described. It acts as a large fastening pressure on the ceramic roller located between the receiving portions of the ceramic roller, and may locally concentrate on the end face of the ceramic roller that comes into contact with the fastening nut member. If the fastening pressure is locally concentrated on the end face of the ceramic roller, a part of the ceramic roller may be damaged due to the stress concentration. Therefore, it is necessary to prevent the stress concentration of the fastening pressure from occurring.

Accordingly, the present invention has been made based on such knowledge, and an object of the present invention is to eliminate such a problem in the composite roller.

[0011]

SUMMARY OF THE INVENTION The present invention relates to a heat-resistant composite roller, which comprises a metal support shaft and a ceramic roller fitted on the support shaft. By a receiving portion provided at one end of the support shaft and a metal fastening nut member screwed to the other end of the support shaft, tightened and clamped in a state of being heated to an actual operating temperature or higher. This is a composite roller formed. Thus, in the composite roller according to the present invention, the ratio (thickness / width) of the width of the fastening nut member in the axial direction to the thickness in the radial direction is (thickness / width).
Width) ≦ 1.5.

In the composite roller according to the present invention, the receiving portion at one end of the support shaft is constituted by a flange portion formed integrally with the support shaft, and is screwed to one end of the support shaft. It can be configured with a metal nut member as described above.

[0013]

According to the composite roller according to the present invention, in the composite roller of the above-mentioned type, a fastening nut member for fastening a ceramic roller (hereinafter sometimes referred to as a ceramic roller) is provided. The ratio of the width in the axial direction to the thickness in the radial direction (thickness / width) is expressed as (thickness / width) ≦ 1.
By setting to 5, the fastening pressure of the fastening nut member on the ceramic roller is evenly distributed over the entire end face of the ceramic roller in contact. Thus, it is possible to prevent the fastening pressure acting from the fastening nut member from being locally concentrated on the end face of the ceramic roller, and to prevent the ceramic roller from being partially damaged due to stress concentration. Can be.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION A composite roller according to the present invention is a roller in various steps for hot rolling, that is, a pinch roller,
These are used as kicker rollers, looper rollers, transport rollers, and the like. Composite roller 1 shown in FIGS. 1 and 2
0 indicates a pinch roller which is a typical example of the composite roller according to the present invention. 1 is a longitudinal sectional side view of the composite roller 10, FIG. 2 is a partially omitted front view (a) of the composite roller 10 viewed from the left side of FIG. 1, and FIG. It is a front view (b) with a part omitted. The composite roller 10 includes a metal support shaft 11 and a ceramic roller 1 fitted on the support shaft 11.
2 and a fastening nut member 13 for fastening the ceramic roller 12.

The support shaft 11 has a stepped cylindrical shape made of a metal material such as steel, stainless steel, alloy steel, or the like. One end of the cylindrical shaft portion 11a has a diameter larger than the outer diameter of the coaxial portion 11a. In addition to having a cylindrical flange portion 11b, the other end of the shaft portion 11a has a thin cylindrical screw portion 11c slightly smaller in diameter than the outer diameter of the coaxial portion 11a. Screw part 11
c has an external thread on its outer periphery.

In the support shaft 11, an outer periphery of the shaft portion 11a forms an annular recess 11d with respect to the flange portion 11b, and a ceramic roller 12 is fitted into the annular recess 11d. The ceramic roller 12 has a screw portion 11c.
Is fastened and clamped by the fastening nut member 13 and the flange portion 11b by the fastening action of the metal fastening nut member 13 screwed into the nut.

The ceramic roller 12 is a variety of ceramic rollers formed by molding a ceramic material having high heat resistance. As the ceramic raw material, silicon nitride, sialon, silicon carbide and the like can be adopted. Such ceramic raw material is mainly used, and an appropriate additive such as Mg
O, CeO, SrO, ZrO, Al ₂ O ₃ , Y ₂ O ₃ ,
A sintering aid or a binder containing Yb ₂ O ₃ or the like is added and used. For molding the ceramic roller 12, a molding die in which a core metal is arranged inside a rubber mold is used. In molding, a ceramic material dried and granulated by a spray dryer is filled in a mold, and is molded into a cylindrical shape by a rubber press molding method. The obtained molded body is fired after processing its outer periphery and both end surfaces with an NC lathe or the like. The obtained fired body is formed into a ceramic roller having a set dimension by polishing the outer periphery, the inner periphery, and both ends. The inner diameter of the ceramic roller 12 is set slightly larger than the outer diameter of the shaft 11 a of the support shaft 11, and fits into the annular recess 11 d of the shaft 11 a of the support shaft 11. In the combined state, with the composite roller 10 heated to the actual operating temperature, the annular recess 11 of the shaft portion 11a is
d.

The fastening nut member 13 functions to fasten the ceramic roller 12 and is made of the same metal material as the support shaft 11. Nut member 13 for fastening
Is provided on its inner periphery with a female screw 13a corresponding to the male screw of the screw portion 11c of the support shaft 11, and in a state where the ceramic roller 12 is fitted into the annular recess 11d of the shaft portion 11a of the support shaft 11. , And is screwed to the screw portion 11c of the support shaft 11.
The fastening nut member 13 presses the ceramic roller 12 against the inner end surface of the flange portion 11b of the support shaft 11 by screwing on the screw portion 11c of the support shaft 11, and a predetermined distance is formed between the nut and the flange portion 11b. Fasten and clamp with fastening force.

In screwing the fastening nut member 13 into the screw portion 11c of the support shaft 11, the support shaft 11 is heated to a temperature higher than the actual operating temperature, and the fastening nut is attached to the screw portion 11c of the support shaft 11 in this heated state. The member 13 is screwed, and the ceramic roller 12 is fastened by the fastening nut member 13. As means for heating the support shaft 11, a means for energizing and heating the support shaft 11 can be employed. By adjusting the applied current and the application time to the support shaft 11, the support shaft 11 can be heated to an actual operating temperature or higher. Raise the temperature. The composite roller 1
0, if necessary, the screw portion 11c of the support shaft 11
A crimping portion 13b is formed at the joint boundary on the end face of the nut member 13 for fastening, and the relative rotation of the support shaft 11 and the nut member 13 can be regulated by the crimping portion 13b.

In the composite roller 10 having such a configuration,
Since the ceramic roller 12 is used as the roller, the roller has extremely high heat resistance and seizure prevention ability, and can sufficiently cope with the heat resistance required in the hot rolling line. This has the effect of preventing seizure with the material to be rolled to prevent damage to the surface of the roller and maintaining the roller surface in a good condition for a long period of time.

In the composite roller 10, the ceramic roller 12 is heated to a temperature higher than the actual operating temperature of the roller by the fastening action of the fastening nut member 13 so that the flange portion 11b of the support shaft 11 is heated. And the fastening nut member 13 is fastened and clamped, so that even if thermal expansion occurs due to a temperature rise during actual operation of the roller, the fastening state to the ceramic roller 12 is not loosened. The idling of the ceramic roller 12 can be prevented, and the tensile stress acting on the inner diameter side of the ceramic roller 12 is suppressed.
Damage can be prevented.

Further, in the composite roller 10, the female screw 13 a of the fastening nut member 13 and the support shaft 11
Of the screw portion 11c is set to a direction in which the screw portion 11c is fastened by the torque acting on the composite roller 10 during actual operation, so that the loosening of the fastening state during the actual operation of the ceramic roller 12 is further prevented. I'm trying. That is, in the composite roller 10, even in a process in which a large torque is applied to the composite roller 10 in a hot rolling line, the torque is applied in a direction in which the torque is fastened to the fastening nut member 13. Acting, fastening nut member 13
The loosening of the fastening state with respect to the ceramic roller 12 due to the above does not occur.

Thus, in the composite roller 10, the ratio (thickness ΔD / L width) of the axial width L and the radial thickness ΔD of the fastening nut member 13 is represented by (ΔD / L).
≤ 1.5 is set.

In the composite roller 10 constructed as described above, from the result of intensive studies, the fastening nut member 1
3, the ratio of the axial width L to the radial thickness ΔD is
(ΔD / L) ≦ 1.5, and the fastening nut member 1
The fastening pressure applied to the third ceramic roller 12 is evenly distributed over the entire end face of the ceramic roller 12 in contact. This prevents the fastening pressure acting from the fastening nut member 13 from locally concentrating on the end face of the ceramic roller 12, thereby preventing the ceramic roller 12 from being locally damaged due to stress concentration. Can be.

In the composite roller 10, the receiving portion of the ceramic roller 12 on the support shaft 11 is provided with a flange portion 11b provided integrally with the shaft portion 11a of the support shaft 11.
However, instead of the flange portion 11b, a portion where the flange portion 11b is formed has the same configuration portion as the screw portion 11c, and a nut similar to the fastening nut member 13 is provided at the same configuration portion. The nut member can be made to function as a receiving portion by screwing the member.

[0026]

EXAMPLE In this example, as a sample of a composite roller,
A pinch roller (two types), a looper roller, a kicker roller, and a transport roller are manufactured by the following method, and each of the composite rollers 10 as a sample is used for a hot rolling line. The broken state of the constituent ceramic roller 12 at the time of assembly and actual operation was observed.

In the various types of composite rollers 10 described above, the ceramic roller 1 constituting the composite roller 10 is used.
Although the shape (length and diameter in the axial direction) of the ceramic roller 12 differs, the ceramic roller 12 has the same raw material and the same forming method. Each support shaft 11 has a shape and size corresponding to the shape of each ceramic roller 12.

In forming the ceramic roller 12, a forming raw material is prepared. The molding raw material was prepared by adding a sintering aid and a binder to the silicon nitride powder, drying and granulating the mixture with a spray dryer, thereby preparing a ceramic powder for molding. Next, this ceramic powder was filled into a rubber mold having a metal core therein, and was molded into a cylindrical shape by a rubber press molding method to obtain various ceramic molded bodies. Each of the obtained various ceramic molded bodies was subjected to a cutting process using a lathe to have a near-net shape in consideration of shrinkage due to firing and a finishing process allowance.

Various ceramic compacts cut into a near net shape were fired at 1650 ° C. for 2 hours in a nitrogen atmosphere to obtain silicon nitride sintered bodies. The silicon nitride sintered body obtained by firing is, on a cylindrical grinder, the outer circumference, the inner circumference,
Various ceramic rollers 12 were obtained by grinding both end faces, fixing holes, and the like. Table 1 shows the shapes (length and diameter in the axial direction) of the various ceramic rollers 12.

The various ceramic rollers 12 produced in this way are mounted on the corresponding support shafts 11 of the various support shafts 11 produced in correspondence thereto. The actual operating temperature (260 ° C.) of the composite roller 10 while heating by energizing and measuring the temperature with a thermocouple
The temperature of the support shaft 1 is maintained at this temperature.
The ceramic roller 12 is fitted into the one annular recess 11d. Then, various fastening nut members 13 are screwed and screwed onto the screw portion 11c of the support shaft 11, and the ceramic roller 12 is fastened and clamped between the flange portion 11b of the support shaft 11 and the screw. Thereby, various composite rollers 10 are completed.

The employed fastening nut member 13 has the same screw diameter (160 mm) and pitch (1.5 mm), and has an axial width L, a radial thickness ΔD, and
(ΔD / L) are different from each other.
Used for fastening. Table 1 shows the selection relationship of the fastening nut members 13 in each composite roller 10.

In each step of the hot rolling line, each composite roller 10 was used as a line for rolling a SS41 steel material having a diameter of 10 mm in a heated state at 1000 ° C. at a speed of 20 m / sec. Table 2 shows the results of the broken state of the ceramic roller 12 due to use in this hot rolling line.
And (ΔD / L) of the nut member 13 for fastening.
Indicates the appropriate range of values.

[0033]

[Table 1]

[0034]

[Table 2]

Referring to the results in Table 2, the composite roller 10
In order to prevent the ceramic roller 12 that constitutes the above from being damaged by the fastening pressure, the fastening nut member 13
The ratio of the width L in the axial direction to the thickness ΔD in the radial direction is ΔD / L ≦ 1.
5 was found to be good.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view of a composite roller according to an example of the present invention.

FIG. 2 is a partially omitted front view (a) as viewed from one end of the composite roller, and a partially omitted front view (b) as viewed from the other end.
It is.

[Explanation of symbols]

10 Composite roller, 11 Support shaft, 11a Shaft, 11
b: flange portion, 11c: screw portion, 11d: annular recess,
12: ceramic roller, 13: nut member for fastening, 1
3a: female screw; 13b: crimping portion.

Claims (3)

[Claims] 1. A support shaft made of metal, a roller made of ceramic fitted on the support shaft, a receiving portion provided at one end of the support shaft and the other end of the support shaft. A composite roller that is fastened and clamped in a state of being heated to an actual operating temperature or higher by a metal fastening nut member screwed to the, and the axial width and the radial direction of the fastening nut member. A heat-resistant composite roller, wherein the thickness ratio (thickness / width) is set to (thickness / width) ≦ 1.5. 2. The heat-resistant composite roller according to claim 1, wherein the receiving portion at one end of the support shaft is a flange formed integrally with the support shaft. . 3. The heat-resistant composite roller according to claim 1, wherein the receiving portion at one end of the support shaft is a metal nut member screwed to one end of the support shaft. Heat resistant composite roller.