JPH1133691A - Compound sleeve, it manufacture, and rolling roll usign the sleeve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate the manufacture of the compound sleeve for rolling in which an inner sleeve for protracting an outer sleeve is compounded on the inner side of the outer sleeve consisting of a hard material, to reduce the cost, and to improve the cracking resistance of the outer sleeve. SOLUTION: An inner circumferential surface 2a of an outer sleeve 2 is undulated along the circumferential direction, and the surface is fitted to a corresponding surface of an inner sleeve 3 in a rugged manner to prevent the relative rotation of the outer sleeve 2 to the inner sleeve 3 by the key effect of the fitted part. In order to easily improve the close adhesion to the outer sleeve 2, the inner sleeve 3 is formed by a casting method, and further, in order to reduce the residual stress generated after the casting, the temperature of the molten metal during the casting is lower tan the melting point of the outer sleeve 2 to prevent the sleeve 2, 3 from being fused.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a composite sleeve for rolling, a composite sleeve obtained by the method, and a rolling roll made using the composite sleeve.

[0002]

2. Description of the Related Art Rolling rolls in which a sleeve made of a hard metal, a hard alloy, ceramics or the like is attached to improve the wear resistance and economical efficiency of the roll surface (the assembled type is called a sleeve roll) is known. The sleeve is brittle and easily broken. For this reason, a composite sleeve has been developed in which an inner sleeve for protecting the outer sleeve is provided inside an outer sleeve made of a hard material.

In this composite sleeve, it is necessary to combine the outer sleeve and the inner sleeve so that they cannot rotate relative to each other. Japanese Patent Application Laid-Open No. 60-24208 discloses an outer sleeve (outer ring portion) and an inner sleeve (inner ring). Part) is proposed to be fitted with an ellipse. Also, JP-A-60-242
No. 09 proposes that irregularities are formed on the inner peripheral surface of the outer sleeve and the outer peripheral surface of the outer sleeve so as to smoothly undulate along the circumferential direction, and the irregular surfaces are fitted.

Further, Japanese Patent Application Laid-Open No. Hei 2-243736 discloses that an outer sleeve (a cemented carbide ring) is cast into an inner sleeve (a cast alloy) so that the outer sleeve and the inner sleeve are metal-bonded. It has been proposed to reduce the difference in heat shrinkage between the outer sleeve and the inner sleeve in the subsequent cooling process (which promotes cracking of the outer sleeve) by adjusting the composition of the cast alloy and performing heat treatment.

Japanese Patent Application Laid-Open No. 8-158004 discloses that the inner sleeve is formed of high Ni cast iron having a difference in thermal expansion coefficient from the outer sleeve of 4 × 10 ⁻⁶ or less, and the difference in heat shrinkage in the cooling process after casting is reduced. It is suggested to make it smaller.

[0006]

The technique disclosed in Japanese Patent Application Laid-Open Nos. 60-24208 and 60-24209, in which the outer sleeve and the inner sleeve are fitted to each other in a concave and convex manner to prevent relative rotation of the two sleeves, is disclosed in Japanese Patent Application Laid-Open No. 60-24208. If it is not good, torque transmission is performed by some surfaces, stress is concentrated there and causes breakage of the outer ring, so it is necessary to machine the fitting surface of complicated shape with very high precision, Increases cost.

Further, the techniques disclosed in JP-A-2-243736 and JP-A-8-158004 can be said to be reduced to a small extent by the outer sleeve and the inner sleeve which are metal-bonded. It is difficult to completely eliminate the breakage of the outer sleeve during the cooling process after casting.

The technique of the former publication requires heat treatment of the inner sleeve after casting, so that it takes too much time and cost. The technique of the latter publication is economically disadvantageous because high Ni cast iron is expensive. .

Accordingly, an object of the present invention is to provide a method of manufacturing a composite sleeve which is a solution to the above-mentioned problems, an inexpensive and highly reliable composite sleeve obtained by the method, and a method of using the composite sleeve. An object of the present invention is to provide a rolling roll.

[0010]

In order to solve the above-mentioned problems, according to the present invention, in manufacturing a composite sleeve, the inner sleeve is fitted to the inner peripheral surface, the end surface, or both the inner peripheral surface and the end surface of the outer sleeve. A method of casting the inner sleeve by forming a concavo-convex to prevent rotation and using a mold having the surface on which the concavity and convexity are formed as a part of the molding surface and lowering the melting temperature of the material metal below the melting point of the outer sleeve. take. The casting of the inner sleeve is preferably performed by centrifugal casting in order to reduce the gap between the mating surfaces generated by cooling after casting.

In the composite sleeve of the present invention obtained by such a method, the inner sleeve and the outer sleeve are not welded. For this reason, torque transmission between the two sleeves is mainly performed through the concave and convex fitting portion of the mating surface. The irregularities that create the torque transmission fitting part are (a) the surface that undulates along the circumferential direction of the sleeve, (b) the surface that undulates along the circumferential direction and the axial direction of the sleeve, and (c) the outer sleeve. Either of the holes for filling the inner sleeve may be provided, and the undulating surface of (a) may be formed on either the inner peripheral surface or the end surface of the outer sleeve.

Further, the roll of the present invention is fixed to the outer periphery of the shaft through a detent key that locks the above-mentioned composite sleeve to the inner sleeve and the shaft or by a tight spring fitting. The relative rotation between the outer sleeve and the inner sleeve can be eliminated, and the outer sleeve can be prevented from being broken, without complicating the operation and increasing the cost.

[0013]

According to the present invention, since the outer sleeve is formed as a part of the mold and the inner sleeve is provided by casting, it is not necessary to machine the fitting surface with high precision.

Further, since the rotation of the inner sleeve and the outer sleeve is prevented by fitting the concave and convex of the mating surfaces and the mating surfaces are not welded, the generation of residual stress due to the difference in the coefficient of thermal expansion between the inner sleeve and the outer sleeve is small. In addition, there is no need to perform heat treatment to prevent the outer sleeve from being damaged or to replace the inner sleeve material with an expensive material.

[0015]

FIG. 1 shows an embodiment of a composite sleeve according to the present invention. The composite sleeve 1 includes an outer sleeve 2 and an inner sleeve 3.

The outer sleeve 2 is formed of a hard material such as a hard metal, a hard alloy, and ceramics. The inner peripheral surface 2a of the outer sleeve 2 is processed in advance into an uneven surface that is undulated along the circumferential direction, and a metal melt is poured inside the outer sleeve 2 using a mold having this surface as a part of the molding surface. Cast to obtain the composite sleeve shown. The temperature of the molten metal at the time of casting the inner sleeve is set lower than the melting point of the outer sleeve material so as to reduce the residual stress generated after the casting, so that the mating surface of the outer sleeve 2 and the inner sleeve 3 is not welded.

As the material metal for the inner sleeve 3, besides cast iron typified by gray cast iron and spheroidal graphite cast iron, an aluminum alloy or the like can be used, and the material can be properly used according to the purpose of use of the roll. The casting may be performed in the air, but is preferably performed in a vacuum atmosphere or a non-oxidizing atmosphere because oxidation of the outer sleeve 2 can be prevented.

The relative rotation between the outer sleeve 2 and the inner sleeve 3 is prevented by utilizing the key effect of the fitting of the mating surfaces. The unevenness for preventing rotation may be shaped as long as torque can be transmitted through the mating surface. For example, an elliptical shape as shown in FIG. 2 (strictly speaking, a surface which undulates along the circumferential direction) can also be adopted, but from the viewpoint of stress concentration mitigation, a shape as smooth as possible as shown in FIG. From the viewpoint of uniform dispersion of stress, it is preferable that the material undulates regularly.

As shown in FIG. 3, the outer sleeve 2 may be provided with a hole 2b penetrating from one end to the other end, and the hole may be filled with the inner sleeve 3. The hole 2b may be a non-penetrated hole formed in the end face of the outer sleeve, and processing may be a little troublesome. Can be fulfilled.

Further, the surface may be made uneven in two directions, that is, the circumferential direction and the axial direction. FIGS. 4 to 6 show examples of unevenness undulating along the axial direction. When such unevenness is used in combination with unevenness that undulates in the circumferential direction, relative displacement in the axial direction as well as the circumferential direction is prevented.

Further, as shown in FIG. 7, the undulations (irregularities) along the circumferential direction may be formed on the mating surface with the end surface 2c of the outer sleeve 2 (the drawing shows both end surfaces, but one surface is also possible). Often, this is effective when there is no or little radial dimensional margin.

Irregularities can be formed on both the end surfaces and the inner peripheral surface of the outer sleeve 2. In this case, the distribution area of the concave and convex fitting portions is widened, and the reliability of torque transmission is improved.

The irregularities on the side of the inner sleeve 3 are formed in a shape corresponding to the irregularities of the outer sleeve 2 by the casting method. Therefore, the irregularities previously provided on the outer sleeve 2 do not need to be high precision, and can be processed at low cost. In particular, when the outer sleeve is manufactured by a powder metallurgy method, it is possible to suppress the processing cost by providing irregularities by pressing or machining before sintering.

The casting of the inner sleeve 3 is preferably performed by using a centrifugal casting apparatus 10, as shown in FIG. Figure 1
Reference numerals 1 and 12 denote holding jigs, 13 denotes a rotating shaft having a drive source (not shown), 14 denotes a pouring nozzle, and 15 denotes a cooling nozzle. The outer sleeve 2 is set between the holding jigs 11 and 12 of this apparatus, and the mold composed of the holding jigs 11 and 12 and the outer sleeve 2 is rotated at a high speed to pour the molten metal A into the inner sleeve 3. Is formed, the molten metal adheres well to the inner surface of the outer sleeve 2 by centrifugal force, and the gap generated at the interface after casting can be reduced.

FIG. 9 shows an embodiment of a sleeve roll made using the composite sleeve of the present invention. Since the roll sleeve without the inner sleeve is easily broken, it is common to avoid key fitting with the shaft and fix it on the shaft by frictional force. However, the composite sleeve 1 of the present invention has a key sleeve as shown in the figure. -4 (this is locked to the inner sleeve 3) and can be attached to the shaft 5 while preventing rotation, thereby simplifying the sleeve roll and reducing costs.

In the figure, 6 is a spacer ring, 7 is a nut, and 8 is a fillet ring.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to obtain a composite sleeve 1 shown in FIG.
Outer sleeve (outer diameter 330mm x inner diameter 250mm x width 50
mm) A cemented carbide was selected as a material, and at the stage where the raw material powder was pressed, the inner peripheral surface was subjected to unevenness processing by an NC processing machine. Thereafter, the powder compact is sintered to form the desired outer sleeve 2.
The outer sleeve 2 was set in a centrifugal casting machine as shown in FIG. p. m at a speed of m
A spheroidal graphite cast iron melt at 1260 ° C. was poured inside.
The temperature of the molten metal was set lower than that of the cemented carbide of the outer sleeve, so that the outer sleeve 2 and the inner sleeve 3 were not welded. Further, cooling after casting is performed by spraying water from a cooling nozzle on the outer periphery of the outer sleeve 2, whereby the outer sleeve 2 is cooled.
After the solidification, a sleeve in which the inner sleeve 3 of cast iron having a thickness of 25 mm after solidification was combined was obtained.

Next, this is finished and the inner sleeve 3
The key sleeve 9 was provided to the composite sleeve 1 shown in FIG. The sleeve roll of FIG. 9 is obtained by attaching the composite sleeve of FIG. 10 to the shaft by key fitting. The sleeve roll made in this manner is easy to manufacture, cost is reduced, and the effect of preventing the outer sleeve from breaking is superior to the conventional product.

The composite sleeve of the present invention is not limited to a key-fitting type assembling sleeve roll as shown in FIG.
It can also be used for Morgan rolls for rolling steel wire rods fixed to the shaft by internal pressure without using a key.

[0030]

As described above, according to the present invention, the outer sleeve and the inner sleeve are fitted to each other so as to prevent relative rotation between the two sleeves. Then, the fitting accuracy of the mating surfaces, which is a problem in this method, is ensured by casting the inner sleeve, and the problem of the generation of the residual stress newly caused by this is made to a structure in which the inner sleeve and the outer sleeve are not welded. This eliminates the need for high-precision processing of the mating surface, heat treatment for reducing the difference in heat shrinkage after casting, and the use of an expensive inner sleeve material, thereby improving productivity and reducing costs.

Further, since the mating surface is not welded, the residual stress is small, and since the mating surface has good adhesion, the stress concentration due to the bias of the transmission torque is small, and the effect of preventing the outer sleeve from breaking is superior to the conventional product. It will be.

In the case where the inner sleeve is formed by the centrifugal casting method, the adhesion of the mating surfaces is improved, and the effect of preventing the outer sleeve from being broken and the reliability of torque transmission are further improved.

In the case where the outer sleeve and the inner sleeve are fitted on both the inner peripheral surface and the end surface of the outer sleeve, torque transmission is performed in a wide range, so that stability and reliability are further improved.

Further, the torque transmission using the surface that rises and falls along the circumferential direction and the axial direction of the sleeve,
The outer sleeve and the inner sleeve are also prevented from moving in the axial direction, further increasing reliability.

In addition, since the inner sleeve is key-fitted to the shaft to transmit torque to and from the shaft, it is possible to simplify the rolling rolls and thereby reduce costs.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view perpendicular to an axis showing an embodiment of a composite sleeve according to the present invention.

FIG. 2 is a cross-sectional view perpendicular to the axis of another embodiment.

FIG. 3A is a side view of another embodiment. FIG.

FIG. 4 is a sectional view showing an example of undulations along the axial direction.

FIG. 5 is a sectional view showing another example of undulations along the axial direction.

FIG. 6 is a sectional view showing still another example of undulations along the axial direction.

FIG. 7A is a cross-sectional view illustrating an example in which an end surface of an outer sleeve is raised and lowered along a circumferential direction. FIG.

FIG. 8 shows an example of a centrifugal casting device.

FIG. 9 is a partially cutaway front view of a sleeve roll using the composite sleeve of the present invention.

10 (a) is a cross-sectional view perpendicular to the axis of a composite sleeve used for the sleeve roll of FIG. 9;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Composite sleeve 2 Outer sleeve 2a Inner peripheral surface 2b Hole 2c End surface 3 Inner sleeve 4 Key 5 Shaft 6 Spacer ring 7 Nut 8 Fillet ring 9 Keyway 10 Centrifugal casting device 11, 12 Holding jig 13 Rotating shaft 14 Pouring nozzle 15 Cooling nozzle A Metal melt

Claims (5)

[Claims] In the manufacture of a composite sleeve for rolling, wherein an inner sleeve is formed by casting an inner sleeve inside an outer sleeve made of a hard material, an inner sleeve is provided on an inner peripheral surface, an end surface or both the inner peripheral surface and the end surface of the outer sleeve. The inner sleeve is cast with the temperature of the molten metal of the material lower than the melting point of the outer sleeve using a mold having the surface on which the unevenness is formed as a part of the molding surface. A method for producing a composite sleeve, comprising: 2. The method according to claim 1, wherein the inner sleeve is cast by a centrifugal casting method. 3. A composite sleeve obtained by the manufacturing method according to claim 1 or 2, wherein the inner sleeve and the outer sleeve are unevenly fitted and are prevented from rotating, and both sleeves are not welded. 4. The unevenness is scattered on (a) a surface that undulates along the circumferential direction of the sleeve, (b) a surface that undulates along the circumferential direction and the axial direction of the sleeve, and (c) the surface is scattered on the outer sleeve. 4. The composite sleeve according to claim 3, which is one of an inner sleeve filling hole provided. 5. The composite sleeve according to claim 3 or 4,
A rolling roll fixed to the outer periphery of the shaft via a non-rotating key engaged with the inner sleeve and the shaft or by an interference fit.