JP2002126807A - Ceramic work roll - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ceramic work roll capable of preventing processing flaws or deterioration of processing accuracy originating in the center fluctuations. SOLUTION: A through hole 27 is provided at the other point than on the central axis of a metal fitting 22 in the same direction as the shell length direction of a ceramic matrix 21 and after the metal fitting 22 is inserted or adhered to both ends of the ceramic matrix 21, a center hole 23 is processed and provided in the metal fitting 22 and the operating sequences are attained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic work roll used for rolling metal and having metal fittings having center holes at both ends.

[0002]

2. Description of the Related Art In a ceramic work roll used for rolling a metal, a rolling runout does not occur so as not to damage a metal or the like as a product to be rolled.
It is required that the accuracy of the center axis of the ceramic work roll, which is the cause thereof, be high and not low, and that the surface be in a good surface state without processing flaws.

[0003] A ceramic work roll used for cold rolling is proposed in Japanese Patent Application Laid-Open No. Sho 59-197307, but the specific work roll structure is not disclosed. Conventionally, the entire work roll is made of ceramics, and no study has been made on the accuracy of the center hole during production. The center hole is also made of ceramics, and when the center hole is made by processing such as cylindrical grinding, the center hole and the center provided in the ceramics are liable to wear and abrasion, and the axial accuracy of the center deteriorates. The roll causes rotational runout, and as a result, processing accuracy such as roundness and cylindricity has been reduced.

The roundness is represented by a difference in diameter in a measurement cross section of a work roll which is a cylindrical body, and is a degree of whether or not the work roll is a perfect circle. The cylindricity is a coaxial geometric cylinder. (Standard cylinder) When the work roll is sandwiched, it is expressed by the difference in diameter when the gap becomes smallest, and indicates the degree of the geometric cylinder.

[0005] In recent years, ceramic work rolls have been proposed in which the center accuracy of the center is not deteriorated due to center sticking or abrasion at the time of work roll processing, and processing scratches and processing accuracy are not reduced. Japanese Patent Application Laid-Open No. 4-361803 discloses a ceramic work roll in which fittings such as die steel and bearing steel, which are preferable materials for a center hole, are attached to both ends thereof by fitting or bonding. The details will be described below.

In a ceramic work roll, if center holes formed in metal fittings attached to both ends of ceramics are used, there is almost no sticking and center wear with the center during processing, and the axial accuracy of the center does not decrease. The metal fittings have a Rockwell C scale hardness of 50 or more, especially 50 to
A tool steel with 65 is used. The center hole is provided in a conical shape, and a through hole is provided inside the center hole. The through hole is important for preventing excess air from remaining inside the fitting portion.
It is a small hole of ５5 mm (diameter). The center hole is used for transmitting the rotation to the center tool when grinding and polishing the surface of the work roll.

[0007] The ceramic material is Sialon. This ceramic work roll is formed by forming ceramic projections at both ends of the ceramic and fitting a metal fitting having a recess and a center hole corresponding to the ceramic projection in advance and a through hole on the inside thereof into the ceramic projection. Then, it is performed by fixing through an adhesive portion made of an epoxy adhesive.

[0008]

In the above-mentioned prior art, since the center hole is formed in the metal fitting before fitting or bonding to the ceramic, the positional accuracy of the center hole and the quality of the fitting or bonding are reduced. Due to the relationship between the two elements, with the brackets attached to both ends of the ceramic,
The center axis tends to shift. As a result, the ceramic work roll is subject to rotational runout, which is likely to cause processing flaws and decrease processing accuracy.

[0009] It is very difficult to correct the deviation of the center axis. In addition, a fitting having only a through hole in the center shaft is fitted,
Thereafter, when the center hole is machined, the center hole is opened along the center shaft through-hole, so that the above is the same as above.

The present invention has been made in view of such problems of the related art, and an object of the present invention is to provide metal fittings having center holes with improved position accuracy at both ends, and to process by center runout. An object of the present invention is to provide a ceramic work roll in which scratches and reduction in processing accuracy are prevented.

[0011]

That is, according to the present invention, a metal fitting with a center hole is fitted or bonded to both ends of a ceramic base, and the metal fitting has a through hole for air release, and one of the holes. A ceramic work roll used for rolling metal provided in contact with a fitting portion with a ceramic base and having the other hole open to the atmosphere, wherein the through-hole has the same direction as the body length direction of the ceramic base. And a ceramic work roll provided on a part other than the center axis of the metal fitting.

The ceramic work roll of the present invention is manufactured by processing a center hole in the metal fitting after the metal fitting is fitted or bonded to both ends of the ceramic base. The ceramic base is preferably made of any one of silicon nitride, sialon, zirconia, silicon carbide, and alumina.

[0013]

Embodiments of the present invention will be described below. FIG. 1 is a sectional view of the ceramic work roll of the present invention. The processing of the ceramic work roll 30 is performed by forming ceramic protrusions at both ends of the ceramic base 21, and forming a recess corresponding to the ceramic protrusion in advance and a through-hole that passes through the metal fitting 22 in the cross-sectional direction as shown in FIG. 1. The center hole 23 is machined after fitting the metal fitting 22 provided with the protrusion 27 to the convex portion of the ceramics and fixing the metal fitting 22 through an adhesive portion using an epoxy adhesive.

The present invention is characterized in that the through-holes 27 that serve as air vents are provided at positions other than on the central axis of the metal fittings 22 at both ends.
Can be manufactured independently of the center axis of the through hole 27, so that the center hole 23 can be manufactured with high accuracy. As a result, the rotation of the ceramic work roll 30 does not occur, so that it is possible to prevent the occurrence of processing scratches and a reduction in processing accuracy.

In the ceramic work roll 30, the center axis of the metal fittings 22 at both ends is defined as the ceramic base 2.
1 is a shaft located at the center of the metal fitting 22 in the same direction as the body length direction, and the through holes 27 provided on the both ends other than on the central axis of the metal fitting 22 are, for example, both ends as shown in FIG. The through hole 2 formed on a plane perpendicular to the central axis of the metal fitting 22 and in the same direction as the cross-sectional direction of the ceramic base 21.
7

A metal fitting 22 is attached to the ceramic base 21.
After fitting or bonding, the center hole 23 is
The center hole 23 is formed by forming
Due to the relationship between the two factors of the positional accuracy of the above and the quality of fitting or bonding between the ceramic base 21 and the metal fitting 22, the problem that the center axis is displaced can also be avoided.

As a main material of the ceramic base 21, silicon nitride, sialon, zirconia, silicon carbide, alumina, or the like can be used, but silicon nitride is most preferable because of its high toughness and excellent high-temperature bending strength.

[0018]

EXAMPLES Hereinafter, the ceramic work roll of the present invention will be described in more detail using examples, but the present invention is not limited to these examples. (Embodiment) A ceramic work roll 30 of the present invention shown in the sectional view of FIG. 1 was produced by the following procedure using silicon nitride as a raw material. First, a predetermined amount of a sintering aid and a binder are added to the raw material, mixed, dried and granulated, and the obtained granulated material is filled in a rubber mold and molded by a hydrostatic press. Four molded bodies having a diameter of 50 mm and a length of 650 mm were produced.

Next, the formed body is processed into a predetermined shape by an NC lathe, and calcined at 400 ° C. in the air to remove the binder.
After firing for 4 hours, four sintered bodies were obtained. The obtained sintered body is processed to an outer diameter of 40 mm and a length of 450 mm using a metal bond diamond grindstone.
Finished to be 9mm, length 15mm convex shape,
As a result, four ceramic base bodies 21, each of which was a single silicon nitride, were obtained.

Next, a metal cylinder made of S45C is machined with a lathe to an outer diameter of 38 mm and a length of 50 mm, and an outer diameter of 29 m is formed as a fitting hole so that one end serves as a fitting allowance.
m, finished in a concave shape with a length of 15 mm, and further processed a through hole 27 (air vent hole) with an outer diameter of 3 mm passing through the outer peripheral surface and the fitting hole in a direction perpendicular to the central axis by a drilling machine, Eight metal simple substances as the metal fittings 22 were obtained.

Next, the metal fittings 22 are shrunk on the fitting shafts at both ends of the ceramic base 21, and then center holes 23 are formed on both end faces of the metal base 22 with reference to the body of the ceramic base 21. Thus, four ceramic work rolls 30 were obtained.

The amount of deflection of the fitting shaft of the silicon nitride alone (ceramic base body 21) in the course of manufacture was measured with respect to the body, and the amount of deflection of the center hole 23 with reference to the body of the completed ceramic work roll 30 was measured. The results are as shown in Table 1.

Further, when the center of the ceramic work roll 30 is supported and the outer peripheral surface of the body is ground, the amount of deflection of the center of the ceramic base body 21 in the body length direction supported by the center and the roundness, Table 1 also shows the observation results of the cylindricity over the entire torso region and the surface condition.

[0024]

[Table 1]

(Comparative Example) Through hole 37 provided in metal fitting 32
(Air vent hole) was provided on the central axis in the same manner as in the example, except that the ceramic work roll 4 shown in FIG.
0 were obtained. In the same manner as in the embodiment, the amount of deflection of the fitting shaft of silicon nitride alone (ceramic base material 31) in the course of manufacture, and the amount of deflection of the center hole 33 with reference to the body of the completed ceramic work roll 40. The result of measuring
It is shown in Table 1. Similarly, when the center of the ceramic work roll 40 is supported and the outer peripheral surface of the body is ground,
Table 1 also shows the amount of run-out, the roundness, the cylindricity of the entire torso portion, and the surface state of the ceramic base body 31 in the center direction in the ceramic body 31 supported by the center.

(Consideration) If the through hole is provided on the center axis of the metal fitting, that is, at the center position in the same direction as the length direction of the body of the work roll, the center hole oscillates greatly, and a problem occurs during machining. It was considered. The amount of run-out, roundness, and cylindricity of the center portion of the ceramic base in the body length direction was large, and the surface state was not satisfactory because of the observation of processing flaws. In the work roll of the present invention, the runout of the center hole is small, and the runout amount and roundness of the center of the ceramic base in the body length direction when the center of the body of the ceramic is ground by grinding the outer peripheral surface of the body roll while supporting the center of the work roll. , And cylindricity were small, and the observation results of the surface state were also good.

[0027]

As described above, according to the present invention, a metal fitting having a center hole is fitted or adhered to both ends, and a through-hole for venting air is provided on a portion other than the center axis of the metal fitting at both ends. Further, since the ceramic work roll manufactured by the procedure of machining and providing the center hole after the fitting is fitted or adhered to the ceramic base is provided, the fitting or bonding of shrink fit or the like is surely performed. It is possible to suppress the deterioration of the axial accuracy of the center due to the influence of the center sticking and abrasion or the position of the through hole, thereby eliminating the processing flaws and suppressing the deterioration of the processing accuracy. A ceramic work roll having no processing scratches and improved processing accuracy such as roundness and cylindricity can stably roll a high-quality metal product.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing one embodiment of a ceramic work roll having a structure in which a through hole is provided other than on the center axis of a center hole according to the present invention.

FIG. 2 is a cross-sectional view showing one embodiment of a conventional ceramic work roll.

[Explanation of symbols]

21, 31: ceramic matrix, 22, 32: metal fittings, 2
3, 33: Center hole, 27, 37: Through hole (air vent hole), 30, 40: Ceramic work roll.

Claims (3)

[Claims] 1. A metal fitting having a center hole is fitted or bonded to both ends of a ceramic base, and a through hole for air release is provided in the metal fitting, and one hole is provided in a fitting portion between the metal fitting and the ceramic base. A ceramic work roll used for rolling metal, provided in contact with the other hole and opened to the atmosphere, wherein the through-hole is other than on a central axis of the metal fitting in the same direction as a body length direction of the ceramic base. A ceramic work roll, which is provided in a ceramic work roll. 2. The ceramic work roll according to claim 1, wherein the metal fitting is formed by processing a center hole in the metal fitting after the metal fitting is fitted or bonded to both ends of the ceramic base. 3. The ceramic work roll according to claim 1, wherein the ceramic base is mainly composed of any one of silicon nitride, sialon, zirconia, silicon carbide, and alumina.