JPS59137170A - Composite roll and using method thereof - Google Patents

Abstract

PURPOSE:To minimize the expansion and contraction load over the entire part of a sleeve to be inserted onto an arbor and to prevent the generation of blister and heat crack owing to expansion by dividing said sleeve to plural segments. CONSTITUTION:A sleeve is divided to three segments; the 1st sleeve 40a, the 2nd sleeve 40b positioned in the middle, and the 3rd sleeve 40c. The divided sleeves are formed with prescribed allowances (g) for expansion between the respective adjacent sleeves. Two key grooves 44a are grooved in one circumferential end edge of the sleeve 40a and two key grooves 44b are punched in the other circumferential end part. Keys 42a, 42b are fixed by means such as bolting to an arbor 38 in the corresponding positions of the respective key grooves 44a, 44b to attach the sleeve 40a slidably in the longitudinal direction with respect to the arbor 38 and unturnably in the circumferential direction. The other sleeves 40b, 40c are also coupled by the similar means.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a composite roll in which a sleeve is inserted around the outer periphery of an arbor and connected by means such as shrink fitting or loose fitting, and a method for using the same.

A roll basically consists of a cylindrical part and a neck that supports the cylindrical part at both ends. It is broadly divided into so-called composite rolls, which are made by inserting a sleeve into the roll.

This composite roll is suitably used, for example, as a pinch roll for pulling hot slab slabs under pressure in continuous casting equipment, or as a roll for hot conveyance of slabs. More specifically, in the continuous casting equipment shown in FIG. 1, molten steel injected from a tundish 10 into a mold 12 hangs down as a slab slab 14 with only the outer jacket solidified, and this hot slab slab 14 hangs down. 14 is a series of support rolls 16. Guide rolls 18 and pinch rolls 20 ensure stable delivery.

Since the surface temperature of these rolls rises to about 600 to 850°C when they come into contact with the hot slab slab 14, conventionally, as shown in Fig. 2, the outer periphery of the arbor 22 forming the roll body is coated with martensite A composite roll is used in which a single sleeve 24 made of a heat-resistant alloy such as stainless steel or chromium-molybdenum steel is inserted and connected by shrink fitting or other loose fitting. In this composite roll, the surface of the sleeve 24 is exposed to high temperatures and expands, but since cooling water flows through the arbor 22 through the through hole 26 drilled in the center, the temperature does not rise much, so the temperature between the two does not rise much. A considerable temperature difference occurs, and the tightening force of the sleeve 24, which has a large thermal expansion, against the arbor 22 is reduced. For this reason, in the circular portion A shown by the broken line in FIG.
) to (d), one end of the sleeve 24 is welded 28. to the arbor 22. The sleeve 24 is fixed by pins 30 and other screws 32, and the other end of the sleeve 24 is left free so that the sleeve 24 can expand and contract in the longitudinal direction.

In this way, conventional composite rolls are designed to allow the sleeve to expand and contract in the longitudinal direction relative to the arbor, but in reality, the sleeve 24 comes into contact with the hot continuous casting slab and heats up as described above. Furthermore, the group of guide rolls is sprayed with cooling water and forced to rapidly cool down, resulting in rapid temperature rises and falls, and furthermore, the expansion and contraction of the sleeve 24 relative to the arbor 22 is not always uniform over its entire length. As a result, there were problems in that the sleeve would bulge in the center, resulting in blistering, and heat cracks would occur. In particular, in the pinch roll group, in order to make the thickness of the slab slab uniform, the roll spacing is finely adjusted to achieve the optimal rolling edge. However, if the pinch rolls develop the blistering phenomenon, the slab casting It is clear that the quality of the piece itself is adversely affected.

Furthermore, in addition to being used in locations that are affected by high temperature heat, such as the continuous casting equipment, long composite rolls may be used in harsh working environments. In this case, if the sleeve does not wear uniformly and wears out unevenly, it would be very expensive to replace the entire long sleeve each time, so it would be convenient if only the worn parts could be repaired.

The present invention was devised for the purpose of solving the problems inherent in the composite roll according to the prior art described above. By installing the sleeves in such a way that they can slide in both longitudinal directions of the arbor and cannot rotate in the circumferential direction, the expansion/contraction load applied to each sleeve can be minimized, thereby preventing the blistering phenomenon and heat cracks. In addition to preventing the occurrence of damage, it is possible to easily replace only the worn and damaged sleeves in each sleeve group.

Therefore, the composite roll according to the present invention includes an arbor and a plurality of divided sleeves inserted around the outer periphery of the arbor, and the plurality of sleeves have a predetermined expansion margin between adjacent sleeves, Further, the sleeve located at least in the middle of the plurality of sleeves is attached to the arbor so as to be slidable in both longitudinal directions of the arbor, but not rotatable in the circumferential direction.

By the way, when the composite rolls according to the present invention configured as described above are used by sequentially arranging a large number of composite rolls in parallel at predetermined intervals, it is possible that the expansion allowances formed on the adjacent composite rolls are aligned in a straight line as a whole. If they are arranged so as to be aligned, for example, in continuous casting equipment etc., problems such as cooling syndrome will occur in the continuous casting slab.

In order to prevent this, a method of using a composite roll according to another invention of the present application is composed of an arbor and a plurality of divided sleeves inserted through the outer periphery of the arbor, and the plurality of sleeves are adjacent to each other. There is a predetermined expansion margin between each sleeve that fits together, and a sleeve located at least in the middle of the plurality of sleeves is slidable in both longitudinal directions of the arbor but cannot be rotated in the circumferential direction. When a large number of composite rolls attached to the arbor are arranged in parallel at predetermined intervals, the expansion allowance formed on each composite roll is formed on another composite roll adjacent to the composite roll. It is characterized in that the arrays are used so as to mutually sum up the expansion allowances.

Next, the composite roll according to the present invention will be described in detail below by giving preferred embodiments and referring to the attached drawings.

FIG. 4 is a partially cutaway side view showing an embodiment of the composite roll 34 according to the present invention, and FIG. 5 is a perspective view of the composite roll shown in FIG. 4. The illustrated composite roll 34 includes an arbor 38 having a through hole 36 for cooling water to flow through in the central axis direction, and a plurality of divided sleeves 4 inserted through the outer periphery of the arbor 38.
It basically consists of 0a to 40n. That is, in the case of FIG. 4, the sleeve is divided into three segments: a first sleeve 40a, a second sleeve 40b located in the middle, and a third sleeve 40c. The arrangement is such that a predetermined expansion margin g is formed between the sleeves. This expansion amount g
The optimum value of the dimensions is specifically determined in consideration of the thermal expansion coefficient specific to the sleeve 40, the temperature rise limit, the temperature expansion difference between the earth core sleeve 40 and the arbor 38, etc.

In addition, the material of each sleeve is appropriate depending on the working environment in which the composite roll is used, and when used in the continuous casting equipment, heat-resistant alloys such as martensitic stainless steel or chromium-molybdenum steel are used. is considered to be the material.

Further, each of the plurality of sleeves 40a to 40c is attached to the arbor 38 by appropriate means so that it can slide in both longitudinal directions of the arbor 38 and cannot rotate in the circumferential direction. . In this case, "the divided sleeve 40 as each segment is slidable in both longitudinal directions of the arbor 38" means that when the divided sleeve 40 increases in temperature and thermally expands, the sleeve moves toward the arbor 38. This refers to being expandable in the direction of narrowing the expansion allowance g along both longitudinal directions, and the split sleeve 40 is loosely fitted to the arbor 38 in such a manner that it can always freely slide in the longitudinal direction of the surface. does not mean.

Various types of means can be used to connect each divided sleeve 40 to the arbor 38 and transmit the rotational driving force applied to the arbor 38 to the sleeve 40.
In this embodiment, a key connection using a key 42 fixed to the arbor 38 and a keyway 44 provided at the end of each sleeve is preferably used. For example, in FIGS. 4 and 5, one circumferential edge of the split sleeve 40a has a diameter of 180 mm.
Two key grooves 44a are bored at an interval of 180 degrees, and two key grooves 44b are bored at an interval of 180 degrees on the other circumferential edge with a phase angle of 90 degrees with respect to the key groove 44a. ing. Then, this sleeve 40a is attached to the arbor 3.
After inserting the key 42a into the outer periphery of the key 8, the key 42a is inserted into the corresponding position of each keyway 44a, 44b.

42b is fixed to the arbor 38 by bolting or other means such as welding, so that the split sleeve 40a can be slid in both longitudinal directions with respect to the arbor 38, but cannot be rotated in the circumferential direction. Can be installed. Further, the other divided sleeves 40b and 40c are also keyed together by the same means. As shown in FIGS. 6(a) to 6(C), the key 42 may have a circular cross-section, an oval shape, a striped rectangular shape, or the like, as appropriate, to avoid concentration of stress in a specific location. is desirable.

As described above, it is preferable that the key grooves 44 and the corresponding keys 42 formed in the side circumferential edges of each split sleeve 40 are arranged in a staggered manner with a predetermined phase angle. 7 (a) to (C). In FIG. 7(a), the keyways 44a and 44b are arranged in a staggered manner with a phase angle of 90° as shown in FIGS. 4 and 5.
In FIG. 7(b), three keyways 44a are bored at 120° intervals on the circumferential edge of one sleeve, whereas the keyways 44a are formed on the circumferential edge of the other sleeve with a phase angle of 60°. Similarly, three keyways 44'b are drilled at 120" intervals. FIG. 7(C) shows four keyways 44'b drilled at 90° intervals.
One keyway 44a is drilled, and four keyways 44b are similarly drilled at 90° intervals with a phase angle of 45°, but this is not necessarily a staggered arrangement based on these phase angles. It doesn't require that. Note that, as shown in FIG. 4, the top of the key 42 is of course set to be located below the surface level of the split sleeve 40.

Further, in the embodiment shown in FIG. 4, all of the three divided sleeves 40a to 40c are keyed together and configured to be slidable relative to the arbor 38 in the longitudinal direction of the surface. However, in the present invention, it is not a requirement that all the divided sleeves be able to slide in both longitudinal force directions, and only the sleeve located at least in the middle among the plurality of sleeves is capable of sliding in both longitudinal force directions of the arbor. It suffices if it is attached so that it can slide in the direction and cannot rotate in the circumferential direction. For example, as shown in FIG. 8, the circumferential edge of one of the divided sleeves 40a and 40c located near each end of the arbor 38 is fixed to the arbor 38 by means such as shown in FIG. 3, such as by welding 46. However, it goes without saying that only the split sleeve 40b located in the middle may be key-coupled so that it can be attached so as to be slidable in both longitudinal directions.

Furthermore, if the sleeve 40 is thick, the key groove 44 formed in the circumferential edge of the sleeve may not be a cutout groove but a bottomed groove as shown in FIG. 9. In this case, the keyway 44 is not exposed as a notched groove on the outer periphery of the sleeve 40, so it is suitable for use in a nipping roll, etc. in continuous casting equipment, without leaving groove marks on the surface of the slab slab. .

Moreover, FIGS. 10 and 11 show still another embodiment of the composite roll according to the present invention.

A configuration is adopted in which each of the divided sleeves 40a to 40n is inserted and connected to the arbor 38 without using the keyway or key. That is, in the illustrated embodiment, the outer ends of the divided sleeves 40a and 40n located at both ends of the roll made up of a plurality of sleeves are welded and fixed to the arbor 38 (reference numeral 46). As shown in FIG. 11, each of the divided sleeves 40b to 40ni located between the divided sleeves 40a and 40n has an uneven stepped portion 48 continuous in the circumferential direction on its open end surface. However, the uneven stepped portions 48 of each of these divided sleeves are connected to the uneven stepped portions 48 of the adjacent divided sleeves so as to mesh with each other. For example, in FIG. 11, the uneven stepped portion 48 located at the right end of the one-piece sleeve 40b consists of a convex portion 50a with a large circumferential width (crest) and a concave portion 52 with a small circumferential width (trough).
a, and the rising surface of each convex portion 50a from the valley to the peak is slightly tapered (angle α). Further, the uneven stepped portion 48 located at the left end of the split sleeve 40c is a convex portion 5 having a small circumferential width (peak portion).
0b and a recess 52b having a large circumferential width (trough), and the rising surface from the trough to the peak of each recess 52b is slightly tapered (angle β), And the corner α≠angle β. and convex part 5
0a engages with the concave portion 52b, and the concave portion 52a engages with the convex portion 50b.
However, as mentioned above, since the angles α and β of each taper are different, the concave portions and convex portions of adjacent sleeves are in close contact with each other at their contours as shown in the figure. There is no expansion allowance g in the axial direction of the arbor. However, because of the uneven engagement, each divided sleeve cannot rotate in the circumferential direction. That is, even with the structure shown in FIGS. 10 and 11, the sleeve located at least in the middle of the plurality of divided sleeves is attached so that it can slide in the longitudinal direction of the arbor 38 and cannot rotate in the circumferential direction. This means that the

As described above, the composite roll according to the present invention has a sleeve inserted into the outer periphery of the arbor that is divided into a plurality of segments. Even if it is used in applications where thermal expansion is likely to occur, at least the split sleeve located in the middle stretches in both longitudinal directions, and therefore the expansion/contraction load on the entire sleeve can be kept small. It is possible to effectively prevent the blistering phenomenon in which the central portion of the sleeve expands and the occurrence of heat cracks. Therefore, it significantly contributes to reducing repair costs and improving the quality of slab slabs.

In addition, each split sleeve is configured to be easily attached to and removed from the arbor, so it does not necessarily have to be a composite roll used in a high-temperature environment. It is also suitable for use in cases where significant one-sided wear occurs. In this case, it is only necessary to completely replace the divided sleeve in the part where it has worn out, resulting in a significant cost reduction compared to the case where a single long sleeve is completely replaced and repaired.

Next, a method of using the composite roll according to another invention of the present application will be explained. A composite roll having the above configuration,
As shown in FIG. 12, when a large number of composite rolls 34 are sequentially arranged in parallel with a predetermined spacing, each expansion allowance g formed on each composite roll 34 is aligned with the expansion allowance g formed on another adjacent composite roll. They will line up. Therefore, if this arrangement is adopted, for example, in the continuous casting equipment, the temperature drop will be greater near the end edges of each divided sleeve 4o, which form the expansion allowance g, than in the central portion. For this reason, the portion of the continuously cast slab 14 in an unhardened state that contacts the expansion allowance g of each composite roll is excessively cooled and cannot maintain a uniform heat distribution, resulting in the inconvenience that a so-called cooling layer is formed on the surface of the slab. be pointed out.

Therefore, in the present invention, when a large number of composite rolls are arranged in parallel with a predetermined spacing, the expansion allowance g formed on each composite roll 34 is adjacent to the composite roll 34 as shown in FIG. With respect to the expansion allowance g formed on another matching composite roll 34, mutually glossing (i.e. -
Use an array (so that they are not aligned in a straight line). As a result, the continuous cast slab 1 is conveyed while contacting the composite roll group.
4 come into random contact with the expansion margin forming edges of each sleeve where the temperature drop is large, so the risk of the formation of the cooling layer is completely avoided. Therefore, it will greatly contribute to slab quality control.

[Brief explanation of drawings]

Figure 1 is a schematic explanatory diagram of a group of rolls in continuous casting equipment;
FIG. 2 is a longitudinal sectional view of a composite roll according to the prior art, FIGS. FIG. 5 is a perspective view of the composite roll shown in FIG. 4; FIGS. 6(a) to (C) are explanatory views showing the cross-sectional shape of the key; FIG. 7 is a partially cutaway side view of an embodiment of the roll; (a) to (c) are explanatory diagrams of keyways arranged in a staggered arrangement, Fig. 8 is a side view showing another embodiment of the composite roll according to the present invention, and Fig. 9 is a thick sleeve connected to an arbor. FIG. 10 is a longitudinal sectional view of yet another embodiment of the composite roll according to the present invention, and FIG. 11 is a part of the split sleeve shown in FIG. 10. FIG. 12 is a schematic view showing an arrangement example of a composite roll group, and FIG. 13 is a schematic diagram showing an example arrangement of a composite roll group for carrying out the method of using the composite roll according to the present invention. 38... Arbor 40... Sleeve g.
...expansion allowance

Claims (2)

[Claims] (1) Consisting of an arbor and a plurality of divided sleeves inserted into the outer periphery of the arbor, the plurality of sleeves have a predetermined expansion margin between adjacent sleeves, and the plurality of sleeves A composite roll characterized in that a sleeve located at least in the middle is attached to the arbor so as to be slidable in both longitudinal directions of the arbor, but not rotatable in the circumferential direction. (2) Consisting of an arbor and a plurality of divided sleeves inserted through the outer periphery of the arbor, the plurality of sleeves have a predetermined expansion margin between adjacent sleeves, and the plurality of sleeves The sleeve located at least in the middle has a number of parallel composite rolls attached to the arbor at predetermined intervals so that the sleeve can slide in both longitudinal directions of the arbor and cannot rotate in the circumferential direction. When disposing the composite roll, the expansion allowance formed on each composite roll is arranged so that it matches the expansion allowance formed on another composite roll adjacent to the composite roll by 1illlliL. How to use the mating roll.