AU701197B2 - Water wiping device for rolling mill roll - Google Patents

Description

W example, see "HANDBOOK FOR STEEL AND IRON", 3rd..

Edition, Volume III, page 375). A typical example of such a water wiping device as this is shown in Fig. i.

In this drawing, the numeral 1 indicates backup rolls, the numeral 2 indicates work rolls and the numeral 3 indicates a strip, and the work roll 2 is cooled by coolant ejected from a roll cooling device 4.

The numeral 5 indicates a water wiping device which comprises a main body of the water wiping device 7 having sealing material 6, such as felt, on its tip and a cylinder 9 freely pivoting the main body of the water wiping device 7 around a supporting point 8. And coolant on the roll surface is dropped off from the both ends of the roll barrel and in the outside of the width of the strip 3 by pushing the sealing material 6 on the surface of the work roll 2 with an action of the cylinder 9, which prevents the roll coolant from falling directly on the strip 3.

But the above said water wiping device 5 had the following problems: 1) a top of the sealing material 6 does not come in uniform contact with the roll surface in correspondence to the change of the shape of the work roll 2 to tend to make a gap, for example, because of the change of initial roll crown (for example, trapezoidal roll, concave crown, or convex crown etc.), thermal crown, change of roll -2- 3 diameter due to wear, especially, partial edge wear, 2) the sealing material 6 comes in partial contact with the work roll 2 because of assembling error or setting error of the main body of the water wiping device 7 to make wiping performance unstable and to tend to make a partial wear, 3) the sealing material 6 is strongly pressed on the roll surface to wear rapidly because the wiping effect is made by pressing force of the cylinder 9, and 4) it takes much time to change the sealing material 6 etc..

And these problems caused the problems that partial wear of the surface of the work roll 2 due to rolling or partial wear of the sealing material 6 makes gap between the sealing material 6 and the work roll 2, from which coolant drops on the strip 3 and, in the case of hot rolling, the coolant reduces temperature of the strip 3 or makes uneven distribution of the temperature, thereby reducing workability and causing shape defects such as bending, deforming or uneven thickness and, in the case of cold rolling, the coolant causes rust and uneven annealing, as above said.

As a means for solving these problems, Japanese laid open Patent Application No. 63-224806, for example, proposes a 25 water wiping device for roll coolant of rolling mill roll, which stores freely expandable bag in a storage box with an S• aperture in the side opposite to the rolling roll and has sealing material fixed on the exposed surface from the storage box of said bag and has a pressure controlling valve for keeping the pressure in said bag constant.

Moreover, Japanese laid open Patent Application No. 4- 59106, proposes a water wiping device for a rolling mill roll, which has a storage box opposite to the rolling roll, the storage box storaging a piston and two freely expandable tubes across the piston, the piston having sealing material and projecting its top from said storage H:\Sabene\Keep\Speci\46331-96-kawasakisteeldoc 26/11/98

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4 box. And further, the latter Japanese laid open Patent Application No. 4-59106, shows that a position sensor, such as a pulse generator, detects movement of rack and pinion mechanism attached to the sealing material to position the sealing material.

But the technique described in the former Japanese laid open Patent Application No. 63-224806 has the following problems: 1) It is difficult to fix sealing material on the freely expandable bag. Even if the sealing material is well fixed, when the sealing material comes in contact with roll surface, the sealing material comes off the surface of the bag owing to friction force and has very short life owing to partial wear of the sealing material caused by the *:fact that the exposed surface of the bag is transformed and the surface of the sealing material comes in partial contact with the roll surface and tends to vibrate along the roll surface owing to elasticity of the exposed surface of the bag, which makes water wiping performance unstable.

0 0 2) When the sealing material wears, it is very difficult to replace the sealing material and, therefore, it is necessary to replace the whole bag or the whole storage box and it takes much time to replace it and many 25 kinds of spare parts for replacing are needed.

0. And the technique described in the latter Japanese laid open Patent Application No. 4-59106 has merit of adjusting a gap between sealing material and rolling roll but it has the following problems: 1) It is difficult to attach the sealing material to the front side of piston or to detach the sealing material from the front side of piston and it is necessary to detach the whole storage box from rolling mill and to disassemble the storage box, and therefore it takes much time to replace it and many kinds of spare parts for replacing are needed.

H:\Sabene\Keep\Speci\46331-96-kawa sakis teel.doc 26/11/98 r 5 2) Because high accuracy in detecting position or setting mechanism of the sealing material can not be expected, it is substantially difficult to wipe water by using viscosity of water without putting the sealing material into contact with roll surface non-contact sealing) and, when wiping water by putting the sealing material into contact with roll surface, the sealing material rapidly wears and makes its life short.

The following usual water wiping devices are known in addition to the above said devices: as shown in Fig. 2 of Japanese laid open Utility Model Application No.

58-13803 or in Fig. 3 of Japanese laid open Utility Model Application No. 55-77503, a water wiping plate or wiper elastically put into contact with roll surface at a nearly right angle, as shown in Fig. 1 of Japanese laid open Utility Model Application No. 58-85403, Fig. 1 of Japanese laid open Utility Model Application No. 52-423 or Fig. 5 of Japanese laid open Utility Model Application No. 53-160432, a water wiping surface of the wiping plate or wiper with an a a acute angle top or a plate top (a surface which is upstream in the rotating direction of the roll) is elastically put into contact with roll surface so as to make an acute angle, that is, less than 90 degree, with an external tangent plane of the roll of the upstream side in the rotating direction of the roll at the first contact line S with the roll surface (in the latter two devices, the water wiping plate is positively put into area contact with the roll surface). In said device of contact area becomes larger and a water wiping plate or a wiper is hard to be elastically transformed in the perpendicular direction to the (the next page is page 7) SH: \Sabene\Keep\Speci\46331-96-kawasakisteel doc 26/11/98 I A c EDITORIAL NOTE APPLICATION NUMBER 46331/96 THIS SPECIFICATION DOES NOT CONTAIN PAGES 6, 16, 17.

contact surface, and therefore, if the water wiping plate is hard, it is hard to be deformed according to the shape of the roll surface, thereby making it difficult to get uniform water wiping effect along the roll axis. And if the water wiping plate is made soft to get easily transformed, it rapidly wears. In said device of since a water wiping surface of a water wiping plate or a wiper (a surface which is upstream in the rotating direction of the roll) is put into contact with roll surface to make an acute angle, that is less than 90 degrees, with an external tangent plane of the roll of the upstream side in the rotating direction of the roll at the first contact line with the roll surface, a wedge-shaped space is made between the water wiping surface of the water wiping plate or the roll wiper and the roll surface, in which water wiped from the roll surface stays and ferrous powder, scale and wear powder tends to pile. Moreover, since contact area of the water wiping plate and the roll surface becomes larger, the piled ferrous powder, scale and wear powder are bit into the sealing material to make defect on the roll, thereby resulting in making defect on the rolled material. And the water wiping plate tends to have defect on its surface in the circumferential direction and partial groove there, reducing the water wiping effect.

-7- 8 Furthermore, both said devices of and especially the device of have the fault that they do not have good water wiping effect because cooling water on the surface of the roll rotating at high speed is apt to be drawn into between the water wiping plate and the roll surface by the wedging effect and the problem that, if roll partially wears at the both ends in the width direction of the rolled material, a gap is apt to be made between the water wiping plate and the roll, reducing sealing performance.

In addition, with a view to improving water wiping performance, as shown in Fig. 2(a) and of Japanese laid open Utility Model Application No. 51-101337, a cooling water wiper provided with multistage water wiping edges S- 1lla, llb which are elastically put into contact with a S: horizontal roll 10 so as to make an angle c between an external tangent plane of the roll of the downstream side i in the roll rotating direction and the water wiping edges 1la, lib an acute angle is described, and a cooling water wiper having a spring 13 pressing the wiper support 12 provided with the water wiping edges 1la, lb to the roll is proposed. Moreover, in Japanese laid open Utility Model Application No. 54-142344, as shown in Fig. 3 a roll wiper 18 is described which is provided with a wiping tip 16 comprising flexible material, such as rubber or leather, attached to an edge part 15 which extends into a position opposite to a rolling roll 14 and adjacent to the surface of the rolling roll of the roll guide 15 arranged parallel to the rolling roll, and a plate spring 17 overlaid on the back of the wiping tip, wherein the wiping tip 16 is fixed to make an acute angle between itself and an external tangent plane of the downstream side in the roll rotating direction from its contact line with the roll surface.

SFurthermore, in Japanese laid open Utility Model SH:\Sabene\Keep\Speci\46331-96-kawasakisteel. doc 26/11/98 9 Application No. 55-111602, as shown in Fig. 4, a water wiping plate with a spring for a slabbing mill roll is described which comprises a wiper 20 formed by elastic material plate and wiping by coming in contact with a roll 19 to make an acute angle between itself and an external tangent plane of the downstream side in the roll rotating direction from its contact line with roll surface, a water wiping plate frame 22 whose one end is provided with a wiper and other end is pivotably, via a pin 22', connected to an arm 21 fixing the water wiping plate, and a spring 24 whose one end is fixed at the water wiping frame 22 and other end is fixed at a roll hanger 23 so as to press the wiper against the roll.

By the way, the techniques described in said Japanese laid open Utility Model Application No. 51-101337, Japanese laid open Utility Model Application No. 54-142344 and Japanese S..laid open Utility Model Application No. 55-111602 have the following faults: As shown in Fig. 5, since an angle y between a top end surface Sc of a wiping knife 11 made of bakelite or hard rubber, or a plate-shaped wiping tip 16 made of flexible material such as rubber or leather, or a plateshaped wiper 20 made of flexible material such as synthetic rubber, resin or thin metal plate and its plate surface SP makes an angle of about 90 degrees, even if an angle a between the plate surface Sp of the water wiping knife etc.

and an external tangent plane TD N of the downstream side in roll rotating direction makes an acute angle, an angle 3 between an external tangent plane Tu N of the upstream side in the roll rotating direction and the top end surface S c of the wiping knife etc. will make an acute angle, thereby reducing effect of wiping the coolant on the roll surface. And ferrous powder and scale tends to pile between said top end surface S c and roll surface Su-N, biting into sealing material by friction force of the surface of the roll rotating at a high speed, making defect <H:\Sabene\Keep\Speci\46331-96-kawasakisteel.doc 26/11/98 'Pr 10 on the rolling roll, which results in printing the defect on the rolled material. Moreover, the water wiping plate tends to catch defect on the surface in the rotating direction of the roll, having partial groove, which further deteriorates water wiping effect.

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H: \Sabene\feep\Speci\46331-96-kawasakisteeedoc 26/11/99 To improve water wiping effect, the thinner water wiping knife is better but thinner one has a shorter life owing to wear, increasing replacing work of the water wiping knife, which disturbs rolling operation.

When making it thicker for a long life, faults described in the above tend to happen.

A spring is used for pressing the water wiping knife against the roll. When the spring stroke changes according to wear of the water wiping knife, pressing force decreases and reduces water wiping performance.

When the roll rotates at low speed, good water wiping performance can not be gotten. When the roll has a roll crown, uniform sealing effect in the axial direction of roll can not be gotten. Moreover, problems common to said usual techniques are as follows. Different characteristics are required for main body of a water wiping plate (hereinafter referred to as base body") and for its top end. As the top end comes into contact with the roll surface, it is necessary that it tends to be transformed according to shape of the roll surface and have elasticity and flexibility for getting uniform sealing effect in the axial direction of the roll and considerable hardness to resist wearing.

In the case of hot rolling, as the roll surface temperature is high, heat resistance to resisting the high temperature is also required. On the other hand, -11- 12 the base body is required to be apt to be elastically transformed and, as a whole, to be transformed according to the roll shape and wearing resistance (hardness) and heat resistance are not necessary as is the case with the top end. But no practical shape or material of a water wiping plate or a wiper satisfying these requirements has been proposed.

When using hard material from the viewpoint of wear resistance, it is usually of low elasticity and is hard to be transformed against the shape of the roll surface to deteriorate water wiping performance, on the other hand, from the viewpoint of elasticity and flexibility, when using material having tendency to be transformed according o to 15 to the shape of the roll surface, it is usually of low hardness and of low wear resistance and has a short life as a water wiping plate or a wiper, disturbing the rolling operation owing to replacing it.

Disclosure of the Invention The present invention provides a water wiping device for a rolling mill roll, including a water wiping head positionable at a position contacting with or a position t* 25 separated from a roll of a rolling mill; a supporting frame supporting said water wiping head; a supporting frame supporting means for supporting movably said supporting frame; a positioning means for positioning said water wiping head at a position contacting with or a position separated from said roll, wherein said water wiping head stores, in a storage box having an aperture in a side facing the surface of the roll, a freely expandable and elastic bag; a sealing material projecting from said aperture; a positioning member for positioning said water wiping head on the circumferential surface of the roll fixed on both sides of said storage box in the axial direction of the roll; a pressure control means for /H;\Sabene\Keep\Speci\46331-96-kawasakisteel.doc 26/11/98 13 controlling pressure in said elastic bag so as to expand said elastic bag when positioning said water wiping head at a water wiping position and to shrink said bag when retracting said water wiping head from the water wiping position; wherein said positioning means is fixed on both sides of said storage box in the axial direction of the roll and holds said sealing material on both sides, and has a front end which contacts end sections of the roll when said water wiping head is in the water wiping position.

Preferably said supporting frame supporting means is a pivot parallel to an axis of the roll and said positioning means comprises a hydraulic cylinder connected to the end section of said supporting frame.

.Preferably said supporting frame supporting means is a guiding device supporting said supporting frame so as to move back and forth in a right angle direction to the axial direction of the roll and said positioning means comprises a hydraulic cylinder connected to the end section of said supporting frame.

Preferably at least one of the top and the bottom front ends of said storage box has a stopper having a convex projection projecting in said storage box and one side of the top and the bottom rear ends of said sealing material and opposite to said convex projection of the stopper has a projection engaging with said convex projection.

Preferably the said stopper is removably attached to said storage box.

Preferably at least one of side of both sides of said storage box in the axial direction of the roll has its front side wall broken away except for a rear part storaging said elastic bag and said positioning member on said one side is removably or pivotably attached to said f H:\Sabene\Keep\Speci\46331-96-kawasakisteel.doc 26/11/98 14 side.

The present invention also provides a water wiping device for a rolling mill roll, for wiping water by putting a top end of a sealing material into contact with a circumferential surface of the rolling mill roll in the axial direction of the roll with an elastic pressing means, wherein said elastic pressing means is equipped with a means for controlling pressing force and a means for pressing uniformly in the axial direction of the roll and the top end of said elastic sealing material having a wiping surface and an opposite surface formed into an acute angle of between 30 and 85 degrees, and when the wiping surface is put into contact with the circumferential 15 surface of the roll, the wiping surface makes an angle 01 of over 90 degrees with an external tangent plane of the upstream side in the roll rotating direction at the point of contact of the wiping surface and the roll.

oe Preferably said elastic pressing means comprising a structure stores a freely expandable and elastic bag in the *storage box having an aperture in a side opposite to the surface of the rolling mill roll and stores in front of said bag in said storage box the rear end of said elastic ooeeo sealing material so as to move slidably back and forth and to make the front end of said elastic sealing material e project from said storage box and is equipped with a pressure control means for controlling pressure in said bag.

Preferably at least top end of said elastic sealing material is made of hard wear-resistant rubber.

Preferably the base body of said elastic sealing material is made of soft rubber and the top end of said elastic sealing material is made of hard wear-resistant rubber and the base body and the top end are bonded.

/H:\Sabene\Keep\Speci\46331-96-kawasaksteeldoc 26/11/98 H:Sbe docSei\63- 9-aasks 26/11i98 15 Preferably the hard wear-resistant rubber has Shore hardness of 80-100.

Preferably a joint plane of the top end made of hard wearresistant rubber and the base body made of soft rubber comprises one plane and a plane including this joint plane meets a plane including an operating direction of the resultant force of reaction force and friction force against pressing force operating on the top end of the elastic sealing material at a right angle.

Preferably a joint plane of the top end made of hard wearresistant rubber and the base body made of soft rubber comprises two planes intersecting each other and, of these two planes, a plane including a plane not contacting with a water wiping surface of the sealing material meets a plane including an operating direction of the resultant force of reaction force and friction force against pressing force 20 operating on the top end of the elastic sealing material to make over 90 degrees in the upstream side of the roll rotating direction, and a plane including other joint plane is parallel to or meets in the downstream side of the :rotating direction a plane including an operating direction 25 of said resultant force at the contact section of the top end.

S* Preferred embodiments will be described with reference to the accompanying drawings.

(the next page is page 18) H:\Sabene\Keep\Speci\46331-96-kawasakjsteeldoc 26/11/98 Brief Description of the Drawings Fig. 1 is a schematic view illustrating a usual example of a water wiping device for a rolling mill roll.

Fig. 2 are schematic views illustrating a structure of a usual example for a cooling water wiper.

Fig. 3 are schematic views illustrating a structure of other usual example for a cooling water wiper.

Fig. 4 is a schematic view illustrating a structure of other usual example for a cooling water wiper.

Fig. 5 is an enlarged side view of the main part of a usual example.

Fig. 6 is a schematic view illustrating a structure of the first embodiment of a water wiping device relating to the present invention.

Fig. 7 shows an example of a water wiping head used in the present invention and is its perspective view and is a cross section taken on line A A with arrows.

Fig. 8 shows other example of a water wiping head used in the present invention and is its perspective view and is a cross section taken on line B B with arrows.

Fig. 9 shows other example of a water wiping head used in the present invention and is its perspective view and is a cross section taken on line C C with -18arrows and is a cross section taken on line D D with arrows.

Fig. 10 shows other example of a water wiping head used in the present invention and is a perspective view and is an enlarged view of the main part and is a side view taken on line E E with arrows.

Fig. 11 is a perspective view illustrating movement of Fig. Fig. 12 are perspective views illustrating a shape of bottom end of the sealing material used in the present invention.

Fig. 13 are side views illustrating material of top end of the sealing material used in the present invention.

Fig. 14 is a perspective view illustrating other example of an elastic bag used in the present invention.

Fig. 15 is a schematic view illustrating a structure of the second embodiment of a water wiping device relating to the present invention.

Fig. 16 is an enlarged section view of a water wiping head used in the present invention.

Fig. 17 is a side view illustrating contact condition of a top end of the elastic sealing material and a roll.

Fig. 18 is a side view illustrating wear condition of the elastic sealing material shown in Fig. 17.

-19- Fig. 19 is a side view illustrating contact condition of a top end of other elastic sealing material and a roll of the present invention.

Fig. 20 is a side view illustrating wear condition of the elastic sealing material shown in Fig. 19.

Fig. 21 are views illustrating force operated by roll at a top end of the elastic sealing material.

Fig. 22 are views illustrating action of separating force operating on a joint plane when the joint plane of a top end and a base body of the elastic sealing material comprises one plane.

Fig. 23 are views illustrating one example of action of separating force operating on a joint plane when the joint plane of a top end and a base body of the elastic sealing material comprises two planes.

Fig. 24 are views illustrating other example of action of separating force operating on a joint plane when the joint plane of a top end and a base body of the elastic sealing material comprises two planes.

Fig. 25 are views illustrating other example of action of separating force operating on a joint plane when the joint plane of a top end and a base body of the elastic sealing material comprises two planes.

Fig. 26 is a view illustrating other example of action of separating force operating on a joint plane when the joint plane of a top end and a base body of the elastic sealing material comprises two planes.

Fig. 27 are views illustrating other example of action of separating force operating on a joint plane when the joint plane of a top end and a base body of the elastic sealing material comprises two planes.

Fig. 28 is a view illustrating other example of action of separating force operating on a joint plane when the joint plane of a top end and a base body of the elastic sealing material comprises two planes.

Fig. 29 are views illustrating other example of action of separating force operating on a joint plane when the joint plane of a top end and a base body of the elastic sealing material comprises two planes.

Fig. 30 is a view illustrating other example of action of separating force operating on a joint plane when the joint plane of a top end and a base body of the elastic sealing material comprises not less than three planes.

Fig. 31 is a view illustrating sectional shape and size of the elastic sealing material used in the test machine.

-21- Fig. 32 is a characteristic graph illustrating water wiping performance of comparison 1 and embodiment A in an off-line test.

Fig. 33 are characteristic graphs illustrating water wiping performance of comparison 2 and embodiment A, B in an off-line test.

Fig. 34 is a characteristic graph illustrating the relationship between Shore hardness of the elastic sealing material and wear volume of comparison 1 5 and embodiment A, B after 40-hour test in an off-line test device.

Fig. 35 are characteristic graphs illustrating distribution of wear volume, in the axial direction of a roll, of the elastic sealing material used for 14 successive days in the off-line test.

Fig. 36 is a characteristic graph illustrating total quantity of wear of the elastic sealing material used for 14 successive days in the on-line test.

Fig. 37 is a view illustrating sectional shape and size of the elastic sealing material when the joint plane of a top end and a base body of the elastic sealing material comprises two planes.

Fig. 38 is a bar graph illustrating relationship between material and manufacturing cost ratio of the elastic sealing material.

-22- 23 Best Mode for Carrying Out the Invention As in the preferred embodiment of the present invention an elastic bag expanding and contracting freely is slidably stored in a storage box with an aperture in one side opposite to roll surface of rolling mill and elastic sealing material projecting its top from the aperture is arranged in front of the elastic bag and inner pressure of the elastic bag is adjusted by a pressure adjusting means, the elastic sealing material is projected to the front of the storage box by an expansion of the elastic bag and whole elastic sealing material can be transformed by putting a top end of the elastic sealing material into contact with roll surface at required pressure and the top end of the elastic sealing material can be transformed and l pressed on the roll surface according to shape of the roll surface, which produces nearly uniform water wiping effect for the whole range in the axial direction of the roll.

20 And even if the elastic sealing material and the roll wear, the elastic sealing material is pressed on the roll at constant pressure and keeps good water wiping performance; since the pressure in the elastic bag is kept constant by a pressure adjusting means, if the elastic sealing material S: 25 and the roll wear to make a gap between the elastic sealing oo material and the roll, the elastic bag expands. But the expansion of the ooe opnso o h De o0 I L qw k IriI H:\Sabene\Keep\Speci\46331-96-kawasakisel.doc 26/11/98 elastic bag is limited by the storage box except for the side opposite to the roll, and therefore the elastic bag expands toward the roll and presses the elastic sealing material on the roll by a quantity corresponding to the wear of the elastic sealing material or the roll, thereby keeping good water wiping performance.

Moreover, a compression spring could be used instead of such an elastic bag expanding freely as said one, but, in this case, if the stroke of the compression spring changes(or decreases contraction of the spring) with the wear of the elastic sealing material, the pressing force of the compression spring will change (or decreases), rapidly decreasing water wiping performance, especially at a low rotating speed of the roll.

Further, an air cylinder could be used for pressing at a constant pressure. In this case, the pressing force of the elastic material on the work roll can be kept constant as is the case with the elastic and freely expandable bag as said above, but comparing with the elastic and freely expandable bag, this case might have the following troubles: response is made worse by inertia of a piston rod etc. or friction between the seal of 0 ring etc. and a piston or a piston rod, and it is used in bad circumstances where the cooling water is sprayed, steam is filled and atmospheric temperature is high (in the case of a hot rolling mill).

-24- K

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-74 25 Furthermore, when the elastic and freely expandable bag is used, the elastic sealing material can be arranged directly in front of the elastic bag and on it without any other parts between them, which is different from said compression spring or said air cylinder, and therefore, even if the work roll has a roll crown, it can put the elastic sealing material into contact with the roll at uniform pressure in the axial direction of the work roll.

In addition, according to the preferred embodiment of the present invention the water wiping head supported by a front end of a supporting frame can be freely positioned at either position of a waiting position far from the work roll or at a water wiping position near the work roll by pivoting the supporting frame around a pivot arranged parallel to a roll axis or by moving it forward or backward along a guiding unit with a positioning device (for example, a hydraulic cylinder). And since a pair of positioning members, which position a water wiping head by 20 putting their front end sections into contact with end sections of the work roll in its axial direction when the water wiping head is in the water wiping position, is fixed at both sides of the water wiping head in the axial direction of the roll, even if roll diameter or pass line of a strip is changed, relative relationship in position between the roll H:\Sabene\Keep\Speci\46331-96-kawasakisteel.doc 26/11/98 T C 0 surface and the water wiping head is kept constant.

Moreover, since the pressing force by said positioning device is canceled by reaction force on the positioning member acted by the roll surface, the top end of the elastic sealing material can be constantly put into stable contact with the roll surface in the range of a stroke produced by the elastic and freely expandable bag in the direction perpendicular to the axis of the work roll with considerably small pressing force, which results in producing stable effect of water wiping.

Moreover, if the positioning member is attached to both sides of the storage box in the axial direction of roll and holds the elastic sealing material on its both sides, it is possible to prevent the top end of the elastic sealing material laterally vibrating or moving sideways and to make the contact of the sealing material and the roll surface stable and thus to improve stable water wiping effect.

Moreover, if a stopper projecting into the storage box is put on at least one of top and bottom front ends of the storage box and a projecting member for engaging stopper extending in the axial direction of roll is put on the side opposite to the stopper of the top and bottom rear ends of the elastic sealing material, the elastic sealing material does not come off -26from the storage box owing to its own weight or friction force with the roll surface, whatever angle the storage box assumes.

Furthermore, if said stopper is removably attached to the storage box, it is easy and done in short time to remove the elastic material from the storage box or to insert it into the storage box by removing the stopper.

And if at least one side of both sides of the storage box in the axial direction of the roll has its front side wall broken away except for rear part of the box storaging elastic bag and, of both positioning members, at least one positioning member on the side whose front side wall of the storage box is broken away is removably or pivotably attached on the side wall, even if a stopper for preventing elastic sealing material from coming off is put on the storage box, the elastic sealing material can be sideways removed from the storage box and spare elastic sealing material can be inserted into the storage box from the side by removing or turning by 90 or 180 degrees the positioning member on the side whose front side wall of the storage box is broken away, which makes it possible to change the elastic sealing material easily and in a short time on the operating side of the rolling mill.

In a device wiping water by putting the top end -27- 28 of the elastic sealing material into contact with the roll surface of the rolling mill roll along the axial direction of the roll with an elastic pressing means, by providing said elastic pressing means with a means for controlling the pressing pressure and a means for uniformly pressing in the axial direction of the roll, it is possible to control the pressing force at the top end of the elastic sealing material and to press uniformly in the axial direction of the roll. And the top end of the elastic sealing material can be pressed by the elastic transformation of the whole elastic sealing material to the degree that it can be transformed according to the shape of roll surface, which makes it possible to produce nearly uniform sealing effect for the whole range in the axial direction of the roll, to effectively wipe water, to prevent the top of the elastic *o sealing material from rapid wearing by excessive pressing force, and to keep good water wiping performance by 'pressing the elastic sealing material on the roll at a constant pressure even if the elastic sealing material or 20 the roll wears and by adjusting pressing force so as to keep the pressure on the contact surface constant even if the contact area changes as the elastic sealing material wears.

Since in the preferred embodiment of the present invention the top end of the elastic sealing material is formed into an acute H:\Sabene\Keep\Speci\46331-96-kawasakisteel.doc 26/11/98 c. angle and this acute part is put into contact with roll surface so as to make an angle 81 between an external tangent plane of the roll of the upstream side in the rotating direction of said roll at said contact section and a water wiping surface at the top end of the elastic sealing material over 90 degrees, water film on the roll surface can be effectively wiped off by the top end of the elastic sealing material and the wiped water can be flown away in back of the elastic sealing material without staying.

And since the top end of the elastic sealing material is formed into an acute angle, it can be put into nearly straight line contact with roll surface in the beginning of use of said elastic sealing material; therefore, ferrous powder and scale do not pile between the top end and the roll surface nor bite into sealing section, thereby not making defect on the roll and on the rolled material. And the bitten ferrous powder and scale do not make a groove on the elastic sealing material to make water wiping effect worse.

To put the top end of the elastic material into stable contact with the roll surface, needless to say, the operating direction of the pressing force pressing the elastic sealing material on the roll surface is in the range between the external tangent plane of the roll at said contact line and the roll.

-29- Moreover, it is desirable that this pressing force has operating direction and magnitude so that the opposite side of the water wiping surface of the top end of the elastic sealing material may be transformed to properly come to the roll surface by this pressing force and the top end of the elastic sealing material may have uniform sealing effect for the whole range in the axial direction of the roll according to the shape of the roll surface, for example a roll crown.

These direction and magnitude of the pressing force should be properly selected and decided by taking into account layout of the water wiping device in the rolling mill, roll diameter or roll shape, width of rolled material, contact position of the roll and the elastic sealing material, shape, size and material of the elastic sealing material and elastic transformation capability of the whole elastic sealing material depending on said factors.

If the elastic pressing means comprises the freely expandable bag stored in the storage box with an aperture in a side opposite to the roll, the elastic sealing material stored in said storage box so that the rear section of the elastic sealing material can move back and forth to project the top end of the elastic sealing material, in front of the bag in the storage box, from the storage box and the means for controlling the pressure in the bag, the top end of the elastic sealing material can be pressed to the degree that it can be transformed according to the shape of roll surface by the elastic transformation of the whole elastic sealing material which is realized by expanding the bag to project the elastic sealing material to the front of the storage box and by putting the top end of the elastic sealing material into contact with the roll surface with an adjusted pressure. And this makes it possible to get roughly uniform sealing effect for the whole range in the axial direction of the roll and get effective water wiping effect and does not make the top end of the elastic sealing material rapidly wear by an excessive pressing pressure.

Moreover, even if the elastic sealing material and the roll wear, the elastic sealing material is pressed on the roll always at a constant pressure to keep good water wiping performance; since the pressure in the bag is kept constant by the means for controlling the pressure, the bag expands when the elastic sealing material or the roll wears to make a gap between the elastic sealing material and the roll, but it can not expand except for the side opposite to the roll by the storage box, but expands toward the roll in correspondence with the wear of the elastic sealing material or the roll, pressing the elastic sealing material on ~-31- W the roll, which keeps good water wiping performance.

If the top end of the elastic sealing material used in the present invention is made of hard wearresistant rubber and joined to the base body made of soft rubber, the top end contacting with the roll surface wears little and keeps good water wiping effect for a long time; this leads to reducing frequency of changing the elastic sealing material and not disturbing the rolling operation.

Further, if rubber having a Shore hardness of 100 is used as said hard wear-resistant rubber and inexpensive rubber having a Shore hardness of 50 70 is used as said soft rubber, manufacturing cost of the elastic sealing material can be reduced and wear of the top end of the elastic sealing material can be reduced and the elastic sealing material can be transformed according to the shape of the roll surface as a whole and can keep good water wiping effect for a long time without change of the elastic sealing material.

Furthermore, by forming the joint plane of the top end and the base body of the elastic sealing material into one plane and making a plane including this joint plane meet a plane including the operating direction of the resultant force of the reacting force against the pressing force and the friction force operating at the top end of said elastic sealing -32material from the roll at a right angle, it is possible to make the resultant force operating on the top end operate as a pressing force against the joint plane, thereby preventing separation of the top end and the base body.

Moreover, by forming the joint plane of the top end and the base body of the elastic sealing material into two planes intersecting one another and, of said two planes, by making a plane including a plane not contacting with a water wiping surface of said sealing material meet a plane including the operating direction of the resultant force of the reacting force and the friction force against the pressing force operating at said joint plane on the top end of said elastic sealing material from the roll at over 90 degrees in the upstream side of the rotating direction of the roll and by making a plane including the other joint plane parallel to, or meet in the downstream side in the rotating direction of the roll a plane including the operating direction of said resultant force at said contact point of the top end, shear separation as well as separation of 90 degrees can be prevented.

Embodiments of the present invention will hereinafter be explained more concretely with reference to drawings.

Fig. 6 is a schematic view illustrating the -33- 34 whole structure of the first embodiment of the present invention.

In the drawing, 25 is a water wiping device of the preferred embodiment of the present invention. 26 is a water wiping head fixing sealing material (elastic sealing material) 27 and its structure is described later. 28 is a supporting frame supporting this water wiping head 26 by fixing it on the top end, 29 is a pivot arranged parallel to an axis of work roll 30 and pivotably supporting the supporting frame 28. 31 is a pneumatic positioning cylinder connected to the rear end of the supporting frame 28 with a piston rod 31a and positioning the water wiping head 26 for the work roll 30 at a near position or a distant position. 32 is a positioning member attached to "both sides of the water wiping head 26 in the axial direction of the roll, whose top end 32 is pressed on the surface of the end in the axial direction of the roll to keep relative relationship of the position between the 20 water wiping head 26 and the work roll 30 and to cancel the pressing force of the positioning cylinder 31 by the reacting force of the work roll 30 when the water wiping head 26 is near the circumferential surface of work roll and in the water wiping position. Details of the structure are after described.

33 is an air source supplying air pressure for operation, 34 and 35 are their air pressure supplying e

I/

H:\Sabene\Keep\Speci\46331-96-kawasakisteel.doc 26/11/98 TO I pipes. 36 is a cylinder operating solenoid valve operating the positioning cylinder 31, which changes to P (projecting) side to select an air pressure supplying pipe 37 for projecting, thereby projecting the positioning cylinder 31, and changes to S (shrinking) side to select an air pressure supplying pipe 38 for shrinking, thereby shrinking the positioning cylinder 31. 39 is a pressure control valve.

is a solenoid valve for operating a pilot controlling air pressure in an elastic bag 42 made of rubber, for example, in the water wiping head 26 through air pressure supplying pipe 41 for expanding the bag.

By pressurizing air pressure supplied to the positioning cylinder 31 through an air pressure supplying pipe 43 for the pilot, 40 is changed to P (projecting) side, thereby expanding the elastic bag 42, and by making air pressure unloaded 40 is changed to Ex(exhausting) side, thereby shrinking the elastic bag 42.

Referring now to Fig. 7, the structure of the water wiping head 26 is described.

Fig. 7 is a perspective view of water wiping head 26, and Fig. 7 is a sectional view taken on line A A with arrows. In these drawings, 44 is a storage box storaging said sealing material 27 and the elastic bag 42, the sealing material 27 is attached on the side of the work roll 30 with its top end projected.

I'x are bolts for fixing the positioning member 46 on the both sides of the storage box 44 in the axial direction of the roll, 47 is a stopper of L-shape section which is removably fixed on the top and front end of the storage box 44 with bolts 48 and has a bottom end having a projection 47a projecting downward in the storage box 44.

The positioning member 46 is made of polyamideimide resin, for example, and a chamfered section 46a on its top end is put into contact with the roll surface of the work roll 30 to position the water wiping head 26 at the water wiping position and its main body holds the sealing material 27 projecting from the storage box 44 on the both sides to prevent the top end of the sealing material 27 from vibrating and going out to the side of the storage box 44.

A projection 27a projecting in the axial direction of the roll so as to engage with the projection 47a of the stopper 47 is formed on the top surface of the rear end of the sealing material 27 and when the sealing material 27 is off to the front of the storage box 44 by the friction force with the work roll or self weight of the sealing material 27 this projection 27a strikes against the projection 47a of the stopper 47 and is engaged with it, thereby not being off from the storage box 44.

S-36r t o An operation of the water wiping device of the present invention having said structure is now described. Firstly, when the water wiping head 26 is in the water wiping position of the circumferential surface of the work roll 30, as shown in Fig. 6, a cylinder operating solenoid valve 36 is changed to P side to project a piston rod 31a of the positioning cylinder 31 and to push down the rear end of the supporting frame 28 in the drawing. In this case, the water wiping head 26 fixed on the top end of the supporting frame 28 supported by a pivot 29 is pushed up from the oblique and downward side of the work roll 30 until the front end of the positioning member 32 attached to the side of the water wiping head is put into contact with the circumferential surface of the work roll 30. And air pressure is supplied to the solenoid valve 40 for operating the pilot through the air pressure supplying pipe 43 for the pilot from the air pressure supplying pipe 37 for projecting the positioning cylinder 31, thereby changing the solenoid valve 40 for operating the pilot to P side to supply air pressure controlled by the air controlling valve 39 to the elastic bag 42 in the storage box 44 of the water wiping head 26 through the air pressure supplying pipe 41 for expanding the bag and to expand the elastic bag 42, which pushes the sealing material 27 in the storage box 44 to the front of it and -37presses the top end surface of the sealing material 27 on the circumferential surface of the work roll In this case, since the pressing force by the positioning cylinder 31 is transferred to the work roll through the positioning member 46 and canceled by the reaction force from the work roll 30, it does not work as the pressing force pressing the sealing material 27 on the circumferential surface of the work roll therefore, if the inner pressure of the elastic bag 42 is controlled by the pressure controlling valve 39 on the level that the force pressing the sealing material 27 on the circumferential surface of the work roll 30 is smaller than that of the positioning cylinder 31 and the top end of the sealing material 27 is put into little contact with the circumferential surface of the work roll 30 to be transformed a little and is put into contact with the work roll 30 nearly uniformly and gaplessly for the whole range in the axial direction of the roll, stable water wiping effect is gotten and the sealing material 27 is not rapidly worn by an excessive pressing force nor partially worn by the partial contact.

To retract the water wiping head 26 to the retraction position from said water wiping position, if the solenoid valve 36 for operating the cylinder is changed to S side, the piston rod 31a of the positioning -38cylinder 31 is shrunk; consequently, by the rotating torque caused by pulling force of the positioning cylinder 31 or by self weight around the center of pivot 29, the rear end of the supporting frame 28 is pushed up in the drawing to rotate the supporting frame 28 and to move the water wiping head 26 to the oblique and downward side, which separates the water wiping head 26 from the work roll 30. At the same time, air in the air pressure supplying pipe 37 for projecting the positioning cylinder 31 is exhausted from the exhausting port of the solenoid valve 36 for operating the cylinder and thus air pressure in this air pressure supplying pipe 37 for projecting and in the air pressure supplying pipe 43 for the pilot is reduced and the solenoid valve for operating the pilot is changed to EX side by the reaction force of the spring in it, which exhausts air pressure in the elastic bag 42 from the exhausting port of the solenoid valve 40 for operating the pilot to shrink the elastic bag 42.

Describing now the changing method of the sealing material 27 used for the water wiping head 26, when changing the sealing material 27, loosen the bolts 48 shown in Fig. 7 and pull up the stopper 47, or remove the bolts 48 and the stopper 47 and pull out the sealing material 27 to the front of the storage box 44, insert the spare sealing material 27 from the front of -39- /T the storage box 44 and return and fix the stopper 47 in the state of what it was. In this way, changing the sealing material 27 is easy and can be done in a short time.

In the embodiment of the water wiping head 26 shown in Fig. 7, the embodiment that the stopper 47 is provided on the top front end of the storage box 44 and the projection 27a of the sealing material 27 (a convex projection 47a of the stopper 47) is formed on the top surface of the rear end of the sealing material 27 is described, but the present invention is not limited to this and the stopper 47 can be attached to the bottom surface of the front end of the storage box 44 and the projection 27a can be attached to the bottom surface of the rear end of the storage box 44, or the stopper 47 can be attached to both top and bottom surfaces of the storage box 44 and the convex projection can be formed on both top and bottom surfaces of the sealing material 27.

Moreover, as for the stopper 47, the member of L-shape section need not to be fixed by the bolts 48, as shown in the water wiping head 26A of Fig. 8 a slit aperture 49 can be formed along the top side of the front end of the storage box 44 and the stopper 50 of Lshape section (or T- shape section can be used) can be removably inserted in the slit aperture 49 with its top end 50a projected in the storage box 44.

The other embodiments of the water wiping head of the present invention are described in Fig. 9 to In this embodiment of the water wiping head 26B the stopper comprises a stopper 51 made in the storage box 44 as a body. Since this structure of the stopper makes it impossible to remove or insert the sealing material 27 from the front aperture of the storage box 44, at least one side of both walls of the storage box 44 in the axial direction of the roll (the left side of this drawing) has the side wall 52 only at the section corresponding to the size L of depth of the storage section of the elastic bag 42 and does not have the side wall in the front of it. The sealing material 27 can be slidably removed and inserted for changing in the axial direction of the roll from the side of the storage box 44 with the bolt 45 removed and the positioning member 46 removed. 45a in the drawing is a screw hole of bolt Fig. 10 shows a change of the embodiment shown in Fig. 9 and this water wiping head 26c has a characteristic in the positioning member 46A. In this embodiment, the stopper 51 is made in the storage box 44 as a body like Fig. 9 and therefore the sealing material 27 can not be removed nor inserted from the front aperture of the storage box 44. And thus in this embodiment as with the embodiment shown in said Fig. 9, at least one side of both walls of the storage box 44 in -41the axial direction of the roll (the left side of this drawing) has the side wall 52 only at the section corresponding to the size L of depth of the storage section of the elastic bag 42 and does not have the side wall in the front of it.

And the positioning member 46A comprises the base plate 53b attached to the top end of the arm 53a so as to project it to the outside in the axial direction of the roll and the liner 53c attached to the top surface of this base plate 53b with bolt 53d.

The liner 53c has its top corner taken away to prevent wearing and making defect on the roll surface and this section is put into contact with the circumferential surface of the work roll 30. It is desirable that the material of the liner 53c is softer than that of the work roll surface to prevent partial wear of the work roll and has some degree of hardness, and thus hard resin such as polyamideimide resin, considerably soft non-ferrous metal or non-ferrous alloy is suitable.

The rear end of the arm 53a is pivotably supported by the pivot 55 screwed into the screw hole 54 provided in the side wall 52 of the storage box 44.

This arm 53a, as shown by solid line in Fig. 10 to is fixed by screwing the top end of a bolt 57 going through the penetrating screw hole 56a of the first fixing block 56 fixed oppositely to the arm 53a of the 42 supporting frame 28 so as to hold the sealing material 27 on the side and to locate the liner 53c in the near position of the work roll 30. And the second fixing block 59 having the penetrating screw hole 59a on the supporting frame 28 to the left side of the pivot 55 in the drawing and in the symmetric position of the position of the fixing block 56.

The sealing material 27 in this water wiping head 26c is changed in the following procedures: 1) Loosen the fixing bolt 57 and remove it from the fixing nut 58 on the side wall of the arm 53a. 2) Turn the arm 53a to the left direction to the drawing by 180 degrees to set it in the state of the Fig.ll. 3) If necessary, screw the top end of the fixing bolt penetrating the penetrating screw hole 59a of the second fixing block 59 into the fixing nut 58 on the side wall of the arm 53a to fix the arm 53a. Moreover, this step can be omitted when the water wiping head 26c is in the position that it can not return to the former position by the rotating torque due to gravity even if it is not fixed. 4) Remove the sealing material 27 from the storage box 44 to the side by sliding the sealing material 27 parallel to the axial direction of the roll.

insert spare sealing material into the storage box 44 from the side by sliding the spare sealing material 27 parallel to the axial direction of the roll. 6) If necessary, loosen the fixing bolt 60 and remove it from the fixing nut 58 on the arm 53a. Moreover, when said step 3) is omitted, this step can be omitted. 7) Return the arm 53a to the former position by turning it to the right direction by 180 degrees to the drawing. 8) Fix the arm 53a by screwing the top end of the fixing bolt 57 penetrating the penetrating screw hole 56a of the first fixing block 56 into the fixing nut 58 of the arm 53a.

In the case of embodiment of water wiping head 26c, since the sealing material 27 can be replaced from the side of the storage box 44 by turning the arm 53a by 180 degrees in a simple operation, the sealing material 27 can be easily replaced within a short time of about minutes even in the narrow space near the side of the rolling mill. Moreover, although the embodiment that the arm 53a can be fixed at the position turned by 180 degrees is described, the angle of turning is not limited to 180 degrees and it can be less than 180 degrees if the arm 53a can be turned and fixed at the position where the sealing material can be removed and inserted from the side of the storage box 44.

In the embodiment of the above said water wiping head the positioning member 46 is fixed on both side walls of the storage box 44 in the axial direction of the roll, but the present invention is not limited to -44q this, for example, the side wall can be fixed on the supporting frame 28. Moreover, it is desirable that the top end of the sealing material 27 is continuously made into a body in the axial direction of the roll, because if the top end is not a continuous body a partial gap could be made between it and the work roll surface and water wiping effect might be deteriorated.

On the other hand, the rear end of the sealing material 27 can have a crown on its rear end so as to be easily transformed according to the initial crown, or the shape of the circumferential surface of the work roll 30. For example, if the work roll 30 has a convex crown, the sealing material 27A can have a concave crown 61 on its rear end as shown in Fig. 12 And if the work roll 30 has a concave crown, the sealing material 27B can have a convex crown 62 as shown in Fig.12(b).

If the elastic bag 42 expands to make its front section flat, the sealing material 27 is transformed to make its rear end surface flat and the top end of the sealing material 27 tends to be transformed according to the crown of the work roll 30, for example, it is transformed to a concave crown for a concave crown of the work roll and it is transformed to a convex crown for a convex crown of the work roll. Moreover, when the crown of the work roll 30 is a concave crown as shown in Fig. 12(c), by providing the rear end of the sealing material 27 with a plurality of slits 63 in the right angle direction of the axial direction of the roll, the top end of the sealing material 27 is transformed to a convex crown and can be easily transformed according to the crown of the work roll By the way, required characteristic for the top end of the sealing material 27 is different from that for the other part of the sealing material 27. Since the top end comes in contact with the roll surface, it is necessary that the top end has elasticity of transformation according to the shape of the roll surface and some degree of hardness and toughness for wearing. Moreover, in the case of hot rolling, since the roll surface has a high temperature, it needs to have heat resistance for the high temperature. On the other hand, the other part is required for being easily transformed according to the shape of the roll, but it does not need wear resistance (hardness) or heat resistance as with the top end. When the sealing material is made of one kind of material as a whole, it is therefore desirable that wear-resistant fluoro rubber having Shore hardness of over 80 is used. On the other hand, taking into account manufacturing cost of the sealing material 27, expensive wear-resistant fluoro rubber can be used only for the top end of the sealing material which comes in contact with the work roll -46- (V Sand wears (for example, numeral 64 in Fig. 13 and inexpensive NBR (acrylonitrile-butadiene-rubber) having high elasticity can be used for the other part of the sealing material 27 (for example, numeral 65 in Fig. 13 and these different materials can be bonded with adhesive.

In this case, it is recommended that when the top end wears, the sealing material 27 is replaced for a spare part as a whole and the top end is replaced and renewed in the off-line work. Further, although a rubber bag is used as a freely expandable elastic bag in said embodiment, the present invention is not limited to this and any material can be used if it is an elastic bag having a structure and material which can freely expand back and forth in the storage box 44. For example, as shown in Fig. 14, an elastic bag 42A comprising a front end 67 of a bellows member 66 of a rectangular section formed by elastic thin metal sheet and a rear end 68 closed by flat metal sheet can be used.

Fig. 15 is a schematic view illustrating the structure of the second embodiment of the water wiping device according to the present invention. In this drawing, 69 is a guiding device for guiding and supporting the supporting frame 28 to the right angle direction of the barrel axis direction of the work roll The operation of projecting and shrinking the positioning -47cylinder 31 is contrary to that of the first embodiment and it is different from the first embodiment in the point that the air pressure supplying pipe for the pilot 43 pressurizing the solenoid valve for operating the pilot 40 is connected to the air pressure supplying pipe for shrinking 38, but in other points it has the same structure as the first embodiment.

Referring now to the movement of the water wiping device 25A of the second embodiment composed like this, when the solenoid valve for operating the cylinder 36 is changed to P side, the positioning cylinder 31 is projected by air pressure from the air pressure supplying pipe for projecting 37 and the supporting frame 28 is moved upward on the guiding device 69 and the water wiping head 26 is separated and retracted from the work roll On the contrary, when the solenoid valve for operating the cylinder 36 is changed to S side, the positioning cylinder 31 is shrunk by air pressure from the air pressure supplying pipe for shrinking 38 and the water wiping head 26 is made to approach the work roll until the positioning member 32 is put into contact with the circumferential surface of the work roll At the same time, the solenoid valve for operating the pilot 40 is changed to P side by air pressure from the air pressure supplying pipe for the pilot 43 and the -48elastic bag 42 is expanded by air pressure from the pressure controlling valve 39 to make the sealing material 27 approach the work roll 30 to wipe the water.

Moreover, the second embodiment is different from the first embodiment in the point that in the first embodiment the water wiping head 26 is made to approach the work roll 30 by projecting the positioning cylinder 31 and on the other hand in the second embodiment the water wiping head 26 is made to approach the work roll by shrinking the positioning cylinder 31 so as to make the space required for setting the device as small as possible, and there is no difference in effect and a difference only in the design between two embodiments.

Moreover, it is described that the positioning cylinder 31 in two embodiments of the water wiping device uses the hydraulic cylinder, but the present invention is not limited to this and, for example, an electrically-powered cylinder or a driving unit of rotating screw type can be used. In this case, an electrically-powered cylinder or a solenoid valve operating with the movement of a rotating screw can be used instead of the solenoid valve for operating the pilot Further, said embodiments describe the cases applied to the work roll, but the present invention is not limited to this and, needless to say, it is applied -49- ,-49to the backup roll, if necessary.

Next, the same structure as shown in said Fig. 6 is also basically applied to the water wiping device for the rolling mill roll which comprises an elastic pressing means, as shown as an elastic bag in the embodiment, provided with a means for controlling the pressing force and a means for pressing uniformly in the axial direction of the roll and has the top end of the sealing material formed in an acute angle and, on the other hand, puts the top end of an acute angle into contact with the circumferential surface of the roll so as to make the angle 01 between the external tangent plane of the roll of the upstream side in the rotating direction of the roll at the contact point and the water wiping surface of the top end of the sealing material over 90 degrees.

But as shown in Fig. 16, when the top end 27 of the sealing material formed in a an acute angle is worn, it comes in plane contact with the roll 30 and contact area will increase as the sealing material wears, and if the pressure in the storage box 42 is constant and the pressing force does not change, the contact pressure of the sealing material and the roll 30 will decrease.

Decrease of the contact pressure is a cause of the decrease of water wiping performance by itself and makes it difficult to transform the top end 27t according to the partial unevenness, defect or bitten matter on the roll surface and partial gap tends to happen, which leads to a decrease of water wiping performance.

It is possible to reduce a deterioration speed of the water wiping performance caused by the wear of the sealing material 27 by measuring values, such as using hours or rolling tonnage of the sealing material 27, as a reference for a accumulated wear of the sealing material 27 and by estimating its accumulated wear with the values and by controlling the inner pressure of the bag 42 according to the estimated wear. It is recommended that the pressure control valve 39 shown in Fig. 6 be provided in the operating room of the rolling mill or be the one whose setting pressure is changed by a remote control or automatically changed by a process computer for the rolling mill roll.

Now, it is recommended that, as shown in Fig. 17, the top end 27t of the sealing material 27 bend in L-shape upward in the drawing, and in the opposite direction to the rotating direction of the roll 30, as shown by the arrow X, along the lines A and C which are perpendicular to the drawing and parallel to the central axis 0 of the roll 30 and the top end 27t described by line ANB be put into contact with the roll surface Su SD of the roll 30 at the line N perpendicular to the drawing and the angle a between the A N plane and the I -51- B N plane of the top end 27t be an acute angle, or less 90 degrees, and it is desirable that the angle is not less than 30 degrees and not more than 85 degrees.

When the angle is under 30 degrees, the top end 27t is too thin and has shorter life of wear to cause frequent change of the sealing material 27 and to disturb the rolling operation. On the other hand, when it is over 85 degrees, the top end is too thick and is not easily transformed according to the shape of the roll surface to make partial gaps between it and the roll surface, thereby deteriorating water wiping performance and making the water wiping performance unstable because the angle 81 is near 90 degrees.

Moreover, it is recommended that, on a basis of a normal plane of O-N-R including a central axis 0 of the roll 30 and a line N, the angle 81 between a tangent plane TU-N of the roll 1 at the line N in the upstream direction U of the rotating direction of the roll shown by arrow X and the water wiping plane A-N of the sealing material 27 be an obtuse angle, over 90 degrees and it is desirable that it is not less than 95 degrees and not more than 150 degrees.

When the angle 01 is under 95 degrees, it decreases the effect that the top end 27t of the sealing material 27 wipes the water film on the roll surface effectively and washes it away backward to the sealing -52material 27, thereby reducing water wiping performance.

On the other hand, when it is over 150 degrees, the angle a of the top end 27t of the sealing material 27 needs to be under 30 degrees and causes said troubles.

Moreover, the sealing material 27 is pressed to the direction shown by arrow Y in the drawing by expansion of the bag 42. The top end 27t of the sealing material 27, therefore, is elastically transformed so that a plane B-N of the back-side of the water wiping plane is nearer to the roll surface SD-N of the roll 30 in downstream direction D of the rotating direction of the roll 30 than to a normal plane O-N-R and the angle 82 between the plane B-N and the tangent plane TD-N of the roll may be smaller, thereby making nearly uniform sealing in the axial direction of the roll according to the shape of the roll, such as a roll crown.

It is desirable that said angle 82 is not less than 5 degrees. It is because when the angle a of the top end 27t of the sealing material 27 is small and the top end is thin, in special, when the angle 82 is under degrees, there is a strong possibility that the top end of the back-side of the water wiping plane comes in plane contact with the roll surface and the contact pressure decreases, which tends to make partial gap between it and the roll surface and to deteriorate the water wiping performance in some case. Moreover, it is -53because the smaller said angle 82 is, the larger the contact area of the roll surface and the sealing material 27 becomes because of the wear of the sealing material 27 and the smaller the pressure on the contact surface becomes, which might make local gap between the sealing material and the roll surface and reduce the water wiping performance.

To prevent such a deterioration of water wiping performance, when the pressure on the contact surface is increased by increasing the pressing force of the sealing material 27, the top end 27t rapidly wears; therefore, taking into account the top end angle a, elasticity, hardness and pressing force of the sealing material 27, at least at the beginning of the use of the sealing material 27, it is desirable that said angle 82 has a magnitude which produces nearly uniform sealing effect in the axial direction of the roll according to the shape of the roll, such as a roll crown, and does not put a part of the back-side of the water wiping plane of the top end into plane contact with the roll surface and does not increase the contact area so much rapidly.

In the device comprising said structure according to the present invention, when the top end 27t of the sealing material 27 is put into contact with the circumferential surface of the roll 30, the water film -54on the roll surface Se-N in the upstream side U of the rotating direction of the roll 30 from the normal plane O-N-R and the cooling water flowing on the roll surface is effectively wiped by the water wiping plane A-N of the sealing material 27 and flows away to back of the sealing material 27 and down to the outside of the width direction of the rolled material, not shown in the drawing, from the both ends of the sealing material 27 in the axial direction of the roll and does not drop directly on the rolled material.

Fig. 18 shows a state that after the top end 27t of the sealing material 27 shown in said Fig. 17 is a little worn with an elapse of time and thus it is moved to the operating direction of the pressing force designated by an arrow Y and put into plane contact with the roll surface SU-SD at a plane of NUt-NDt.

The angle Olt between the external tangent plane Tut-Nut of the roll at the line Nut in the upstream direction of the rotating direction of the roll of the contact surface Nut-NDt in this state and the water wiping plane A-Nut of the sealing material 27 is smaller than the 81 in the initial state shown in Fig.17, but if the initial angle 81 is an obtuse angle, greatly over degrees, the angle 81t is kept always over 90 degrees.

Moreover, if said angle 81 and the operating direction of the pressing force of the sealing material 27 is designed so as to keep this angle 81 in an obtuse angle, always over 90 degrees, deterioration degree of the water wiping performance due to the wear is made extremely smaller than that of the usual technique and the life of the sealing material 27 can be made longer.

This is because if said angle 81 is close to 90 degrees, with the wear of the top end 27t of the sealing material, the contact position of the top end 27t and the roll 30 is moved to the downstream D direction of the rotating direction of the roll from the initial contact position (line) and the top end 27t is put into plane contact with the roll and then the angle 81t between the external tangent plane at the end of said contact area in the upstream direction D of the rotating direction of the roll and the water wiping plane of the elastic sealing material 27 might be not more than degrees.

Moreover, as the contact plane Nut-NDt is formed into the shape simulating the shape of the roll surface, such as a roll crown, when looking from the roll axis, and is kept in a contact state with the roll surface, the uniform sealing is formed in the axial direction of the roll; therefore even if the top end 27t wears a little with an elapse of time, the water wiping performance can be kept in almost the same level as the initial one.

-56- By the way, as for said freely expandable bag 42, a compression spring may be used as described before, but in this case the pressing force can not be freely controlled during the operation and when the stroke of the compression spring is changed (the compression allowance is made smaller) as the sealing material 42 wears, the pressing force of the sealing material 27 is changed (decreased) and the water wiping performance is rapidly decreased and good water wiping performance can not be gotten.

An air cylinder may be used as the other means to press at a constant pressure.

In this case, the pressing force of the sealing material 27 on the roll 30 can be kept at a constant pressure as is the case with the freely expandable bag 42, but comparing with the freely expandable bag 42, there may be some problems that it has bad response due to inertia of a piston rod and friction between the seal of the O ring and the piston or the piston rod and that the cylinder is used under bad circumstances where cooling water is sprayed and steam is filled and it is hot (in the case of a hot rolling mill).

Further, when the freely expandable bag 42 is used, the sealing material 27 can be put directly in front of the bag 42 without any other member between them, which is different from the case of said -57compression spring or said air cylinder, and thus the uniform contact pressure can be gotten in the axial direction of the roll 30 even if the roll is crowned.

Moreover, when the air cylinder is used, an adoption of a uniform pressing means in the axial direction of the roll may make it possible to press the sealing material 27 uniformly in the axial direction of the roll 30, though said problems remain. For example, it is recommended that the elastic bag 42 storaging fluid such as gas or water be stored in the storage box 44 with an aperture opposite to the roll 30, and the sealing material be stored in front of the elastic bag 42 so that the top end 27t of the sealing material 27 is projected from the storage box 44 and the rear end of the sealing material 27 can slide back and forth, and a piston member having toughness and sliding back and forth in the storage box 44 be stored in the back of the bag 42, and said piston member be pressed by one or a plurality of air cylinders, and air pressure supplied to said air cylinders be controlled by a pressure controlling means. In this case, said elastic bag storaging fluid such as gas or water is transformed according to the shape of the roll surface such as a roll crown to produce uniform contact pressure in the axial direction of the roll Fig. 19 shows a shape of the top end 27t of the -58sealing material 27 and a state of contact of the top end 27t and the roll 30 and it is an enlarged sectional view of the main part showing other embodiment different from the embodiment of the sealing material 27 shown in the above Fig. 17. Although the top end 27t of this sealing material 27 is formed straightly, not into the L-shape, and pressed in the Y arrow-marked direction parallel to a plane A-N and a plane C-B, it is not substantially different from the sealing material 27 shown in Fig.17. in the effect.

Fig. 20 shows a state that the top end 27t of the sealing material 27 shown in the above Fig. 19 wears a little with an elapse of time and, as a result, moves a little in the operating direction of the pressing force marked by Y arrow and is in contact with the roll surface SU-SD at the contact plane NUt-NDt. The angle Olt between the external tangent plane of the roll Tut- Nut at the line Nut of the upstream side in the roll rotating direction of the contact plane Nut-NDt in this state is equal to the angle 81 in the initial state shown in Fig.19 and is kept always over 90 degrees, if said initial angle 81 is an obtuse angle, or over 90 degrees.

Moreover, since the contact plane NUt-NDt is formed into the shape according to the shape of the roll surface such as a roll crown in the axial direction of the roll and it will be tightly put into contact with -59the roll surface, it follows that the uniform sealing is formed also in the axial direction of the roll; therefore water wiping effect of the almost same level as that of the initial state can be kept even if the top end 27t of the sealing material 27 wears a little with the elapse of time.

By the way, as for material of the sealing material 27, as above said, required characteristic for the top end 27t is different from the that for the main body 27tl except the top end 27t (hereinafter, referred to as "base body").

Since the top end 27t comes in contact with the roll surface, it is necessary that it tends to be transformed according to the shape of the roll surface and has elasticity producing uniform sealing effect in the axial direction of the roll and hardness to resist wearing. And in special, in the case of hot rolling, heat resistance is required for it because the temperature of the roll surface becomes high. On the other hand, it is necessary that the base body 27tl tends to be elastically transformed with the top end 27t as a whole according to the shape of the roll, but it does not require heat resistance and wear resistance, which is different from the top end 27t. But thinking much the characteristic required for the top end 27t, the usual sealing material 27 is usually made of wearresistant rubber having a considerably big hardness.

If the top end 27t of the sealing material 27 is made of hard wear-resistant rubber having Shore hardness of 80 100 and the base body 27tl is made of soft rubber and these two members are joined together, it is possible to reduce wear of the top end put into contact with the roll surface and to keep good water wiping effect for a long period and to reduce frequency of changing the sealing material 27 and to reduce disturbing the rolling operation. Moreover, it is possible that when the top end 27t made of hard wearresistant rubber wears, the whole sealing material 27 is replaced and the worn top end 27t is only replaced and renewed by the off-line work and as a result the base body 27tl made of soft rubber is used many times.

Moreover, since expensive hard wear-resistant rubber is used only for the top end 27t, it is possible to reduce manufacturing cost of the new sealing material 27 and further to reduce the cost of the sealing material 27 by renewing and reusing it as above said.

And by making the base body 27tl of soft rubber, the sealing material 27 will have greater transformation capability as a whole to be easily transformed according to the shape of the roll surface, thereby improving the water wiping effect.

Next, geometric and dynamic conditions, which a -61joint of the top end 27t made of hard wear-resistant rubber and the base body made of soft rubber is expected to have, are described.

As shown in Fig. 21 reaction forces from the roll at the contact point N of the top end 27t of the sealing material 27 and the roll 30 when the top end 27t is pressed on the surface SU-SD of the rotating roll 1 with pressing force P are reaction force Fr against pressing force on the roll and friction force Ff along the external tangent plane N-TD of the downstream side in the axial direction of the roll. In fact, the top end 27t of the sealing material 27 is elastically transformed in a complicated way, but the elastic transformation is neglected here for simple explanation and the resultant force F of the reaction force Fr and the friction force Ff shall operate on the contact point N of the top end 27t of the sealing material 27.

By the way, when the top end 27t made of hard wear-resistant rubber and the base body made of soft rubber of the sealing material 27 are joined, it is expected that the joint plane has one plane and two planes and more.

Firstly, referring to Fig. 22, the case of one plane is described. The joint shown in Fig. 22(a) is a case that a plane including the joint plane x-y meets a plane including the operating direction of said -62resultant force F at the contact point N of the top end 27t of the sealing material 27 and the surface of the roll 30 to make an acute angle in the downstream side D of the roll rotating direction. Supposing that component force parallel to said joint plane x-y of the resultant force F operating on the contact point N of the top end 27t of the sealing material 27 is Fp and component force perpendicular to said joint plane x-y is Fc, the component force Fc operates against the joint plane x-y as pressing force and the component force Fp operates against the joint plane as compression shearing force; therefore separation is not easily happen, but, if the bonding force is not enough large, separation might happen between the top end 27t and the base body 27tl.

On the other hand, The joint shown in Fig.22 (b) is a case that a plane including the joint plane x-y meets a plane including the operating direction of the resultant force F at the contact point N to make a right angle. Since the resultant force F operating at the contact point N of the top end 27t of the sealing material 27 operates against the joint plane x-y as a pressing force at a right angle, the separation of the top end 27t and the base body 27ti is hard to happen.

Next, bonding means comprising two joint planes intersecting one another is hereinafter described.

-63 In this case, there will be nine cases as shown in Fig. 23 to Fig. 29.

Fig. 23 and Fig. 24 shows a case that, of two joint planes, one plane not contacting with a water wiping plane A-N meets a plane including the operating direction of the resultant force at the contact point N to make an acute angle in the upstream side U of the roll rotating direction. And this case is divided into three following cases according to the direction of the other joint plane x-y.

1) Fig. 23(a) is a case that a plane including the joint plane x-y meets a plane including the operating direction of the resultant force at the contact point N in the upstream side U of the roll rotating direction.

In this case, component force parallel to said joint plane x-y of the resultant force F and component force perpendicular to said joint plane x-y are Fxy and Fxyc, respectively, as shown in the drawing, and the component force Fxy operates against the joint plane x-y as compression shearing force, but, because the joint plane y-z receives it, it follows that shearing separation is hard to happen. But since the component force Fxyc operates against the joint x-y as a separating force at right angle, separation tends to happen.

2) Fig. 23(b) is a case that a joint plane x-y is parallel to a plane including the operating direction of 64said resultant force F at said contact point N. In this case, as shown in the drawing, the resultant force F operates against the joint plane x-y as compression shearing force but a plane y-z receives it and thus shearing separation on the joint plane x-y is hard to happen. And component force parallel to the joint plane y-z of the resultant force F and a component force perpendicular to said joint plane x-y are Fyz and Fyzc respectively, as shown in the drawing, and the component force Fyz operates against the joint plane y-z as a compression shearing force, but, since the component force Fyzc operates as pressing force in the right angle to it, shearing separation is relatively hard to happen.

3) Fig. 24(a), are cases that a plane including the joint plane x-y meets a plane including the operating direction of said resultant force F at said contact point N in the downstream side D of the roll rotating direction. In this case, component forces parallel to the joint planes x-y and y-z of the resultant force F are Fxy and Fzy, respectively, as shown in Fig. 24(a), and the component force Fxy operates against the joint plane x-y as compression shearing force but the plane y-z receives it and the component force Fzy operates against the joint plane z-y as tension shearing force but the plane x-y receives it; therefore shearing separation is hard to happen. From a different viewpoint, the component force parallel to the joint plane x-y and the component force perpendicular to said joint plane x-y of the resultant force F are Fxy and Fxyc respectively, as shown in Fig.24 and the component force Fxy operates against the joint plane x-y as compression shearing force but the plane y-z receives it and shearing separation is hard to happen, and the component force Fxyc operates against the joint plane xy as pressing force at 90 degrees and therefore separation is hard to happen, too.

Fig. 25 and Fig. 26 are cases that, of two joint planes, one plane y-z not contacting with a water wiping plane A-N meets a plane including said resultant force F at the contact point N to make a right angle.

And this case is divided into three following cases according to the direction of the other joint plane x-y.

4) Fig. 25(a) is a case that a plane including the joint plane x-y meets a plane including the operating direction of the resultant force F at said contact point N in the upstream side U of the roll rotating direction. In this case, the resultant force F operates against the joint plane y-z as pressing force at 90 degrees and separation at the joint plane y-z is hard to happen.

And component force parallel to the joint plane x-y of the resultant force F and component force perpendicular to said joint plane x-y are Fxy and Fxyc, -66respectively, as shown in the drawing, and the component force Fxy operates against the joint plane x-y as compression shearing force but the plane y-z receives it and thus shearing separation is hard to happen. But the component force Fxyc operates against the joint plane xy as separating force at 90 degrees and thus separation may happen.

Fig. 25(b) is a case that a joint plane x-y is parallel to a plane including the operating direction of the resultant force F at said contact point N.

In this case, the resultant force F operates against the joint plane y-z as pressing force at degrees and operates against the joint plane x-y as compression shearing force but the plane y-z receives it and thus.shearing separation is hard to happen.

6) Fig. 26 is a case that a plane including the joint plane x-y meets a plane including the operating direction of the resultant force F at said contact point N in the downstream side D of the roll rotating direction.

In this case, the resultant force F operates against the joint plane y-z as pressing force at 90 degrees and component force parallel to the joint plane x-y and component force perpendicular to said joint plane x-y are Fxy and Fxyc, respectively, as shown in the drawing, and the component force Fxy operates against the joint plane x-y as compression shearing force but the plane y- -67z receives it and the component force Fxyc operates against the joint plane x-y as pressing force at degrees and thus shearing separation is hard to happen.

Fig. 27 and Fig. 28 are cases that, of two joint planes, one plane y-z not contacting with a water wiping plane A-N meets a plane including the resultant force F at the contact point N to make an obtuse angle in the upstream side U of the roll rotating direction.

And this case is divided into three following cases according to the direction of the other joint plane x-y.

7) Fig. 27(a), are cases that a plane including the joint plane x-y meets a plane including the operating direction of the resultant force F at said contact point N in the downstream side U of the roll rotating direction.

In this case, component forces parallel to the joint planes x-y and y-z of the resultant force F are Fxy and Fzy, as shown in Fig. 27(a), respectively and the component force Fxy operates against the joint plane x-y as compression shearing force but the plane y-z receives it and thus shearing separation is hard to happen. On the other hand, the component force Fzy operates against the joint plane z-y as tension shearing force, though it is a little small and thus shearing separation might happen. From a different viewpoint, component force parallel to the joint plane x-y and I ,68component force perpendicular to the joint plane x-y are Fxy and Fxyc, respectively, as shown in Fig.27(b), and the component force Fxy operates against the joint plane x-y as compression shearing force but the plane y-z receives it and thus shearing separation is hard to happen, but the component force Fxyc operates against the joint plane x-y as separating force at 90 degrees, though it is small, and thus separation may tend to happen relatively.

8) Fig. 28 is a case that a joint plane x-y is parallel to a plane including the operating direction of the resultant force F at said contact point N.

In this case, the resultant force F operates against the joint plane x-y as compression force but the plane y-z receives it and thus shearing separation is hard to happen. And a component force parallel to the joint plane y-z and component force perpendicular to said joint plane y-z are Fzy and Fyzc, respectively, and the component force Fzy operates against the joint plane y-z as compression shearing force but the plane x-y receives it and the component force Fyzc operates against the joint plane y-z as pressing force at 90 degrees and thus separation is hard to happen.

9) Fig. 29(a), are cases that a plane including the joint plane x-y meets a plane including the operating direction of the resultant force F at said contact point 69- N in the downstream side D of the roll rotating direction.

In this case, component forces parallel to the joint planes x-y and y-z of the resultant force F are Fxy and Fzy, as shown in Fig. 29(a), respectively and the component force Fxy operates against the joint plane x-y as compression shearing force but the plane y-z receives it and the component force Fzy operates against the joint plane z-y as compression shearing force but the plane x-y receives it; therefore shearing separation is hard to happen for both component forces. From a different viewpoint, the component force parallel to the joint plane x-y and the component force perpendicular to said joint plane x-y are Fxy and Fxyc, respectively, as shown in Fig.29(b), and the component force Fxy operates against the joint plane x-y as compression shearing force but the plane y-z receives it and thus shearing separation is hard to happen. The component force Fxyc operates against the joint plane x-y as pressing force and thus separation is hard to happen.

Further, a case that the joint plane comprises three planes (n-th planes) is as follows, though it is not practical. As shown in Fig. 30, supposing that a joint plane contacting with the surface of the sealing material A 0 -A-N near to the normal plane N-R is a plane x-yl and a joint plane contacting with the surface of the sealing material 27 N-B-C-C 0 near to the external tangent plane N-TD in the downstream side D of the roll rotating direction at the contact point of the top end 27t of the sealing material 27 and the roll surface Su- SD is a plane y n-l z and between said two planes joint planes yl-y2, y2-y3, y n-2 y n-l, are connected, even if separating force operates against each joint plane, yl y2, y2- y3, y n-2 y n-l, each adjacent joint plane receives it and separating force does not operate at 90 degrees; therefore whether separation will happen depends on how the force operates against said plane x-yl and said plane y n-l z.

In this case, it is advisable to read the plane x-yl for the plane x-y and the plane y n-l z for the plane y-z and to judge which case of nine cases of two joint planes corresponds to the above case.

From the above described, in the present invention, the conditions that the joint plane of the top end 27t made of hard wear-resistant rubber and the base body made of soft rubber of the sealing material 2 7ti does not cause shearing separation as well as degrees separation even if it has not so big bonding force are as follows.

1) If the joint plane comprises one plane, a plane including this joint plane meets a plane including the resultant force of reaction force of pressing force and -71friction force at the contact point of the top end at a right angle.

2) If the joint plane comprises two planes intersecting one another, a plane including a joint plane not contacting with the water wiping plane meets a plane including the operating direction of the resultant force of the reaction force of pressing force and friction force at the contact point of the top end at over 90 degrees in the upstream side of the roll rotating direction and a plane including the other joint plane is parallel to a plane including the operating direction of the resultant force of the reaction force of pressing force and friction force at said contact point of the top end or meets it in the downstream side of the roll rotating direction.

In addition, to make a joint section satisfying said conditions and resisting separating, taking into account joining work and replacing the worn top end 27t with a new one, it is advisable to use usual chemical adhesive for rubber which has water resistance, some heat resistance and bonding strength of degree where it is not separated by the resultant force of reaction force from the roll and friction force.

But the present invention is not limited to the invention whose joint plane satisfies said conditions.

If it intends to avoid shearing separation by using -72adhesive having bonding strength of a degree where it is not separated by the resultant force F of reaction force Fr and friction force Ff from the roll surface, or by increasing the bonding strength with engaging members, or by making the surface of the joint a circular arc section or wavy section, even if it does not satisfy said conditions, needless to say, it is included in the scope of the present invention.

Next, an off-line test device having a structure shown in the above Fig. 6, Fig. 16 and Fig. 17 and rotating only one roll was made and an off-line test was conducted. Specifications of this test device and test conditions are shown in Table 1 and specifications of the elastic sealing material used in the test are shown in Table 2, where embodiment A, B are materials suitable for the present invention and comparisons 1 5 are usual materials.

Table 1 Item Specification Roll diameter 400 mm Roll width 350 mm Roll crown center 18 um, concave, sine curve Roll surface roughness 16.2 s Roll revolution 1000 rpm Spray volume 20.0 i/min.

Spray pressure 4.0 kgf/cm 2 Air pressure for bag 0.3 kgf/cm 2 Material of positioning member polyamideimide resin Sealing width 280 mm -73- Table 2 Classifi- Material of Shore Angle Angle Anle Thickcation elastic sealing hardness 1 2 ne material (degree) (degree) (degree) ness Wear-resistant A Wear-resistant 86 75 100 5 11 mm Embodi- fluoro rubber 86 75 00 5 ment B Wear-resistant fluoro rubber SWear-resistant 1fluoro rubber 86 70 2 NBR 60 100 Comparison 3 NBR 70 4 Fluoro rubber 76 SWear-resistant 1 Sfluoro rubber 105 Acrylonitrile-butadiene rubber (hereinafter referred to as NBR") having Shore hardness of 60, fluoro rubber having Shore hardness of 76, wearresistant fluoro rubber having Shore hardness of 86, 96, 105 (hardness is controlled by quantity of carbonic ingredient) were used as material of the sealing material 27 of the embodiment and comparison and the sealing material was formed in one body. The sealing material 27 had the following section size, as shown in Fig.31: a whole length L is 39 mm, a height of the base body H is 11 mm, a height of the top end 27t h is 11 mm and an angle of the top end 27t contacting with the roll surface a is 75 degrees. Moreover, for embodiment A, B, the top end 27t of the sealing material 27 was pressed on the roll so as to make an angle 81 100 degrees (see Fig. 17) and for comparison 1 the top end 27t of the sealing material 27 made of wear-resistant fluoro rubber -74having Shore hardness of 86 was pressed on the roll so as to make an angle 81 70 degrees and for comparison 2, 3 the top end 27t of the sealing material 27 was pressed on the roll on the same conditions as embodiment A, B.

Thickness of the water film on the roll at the roll center of the nearest downstream side in the roll rotating direction to the contact point of the sealing material 27, that is just after water wiping, and thickness of the water film on the roll surface at the end in the axial direction of the roll of the sealing material 27 were measured with the following method and the measured thickness of the water film was made an index of evaluation of water wiping performance.

A dry paper towel of a given area having excellent water absorbing capability was pressed on the roll surface of the roll center and the position corresponding to the end of the sealing material in the axial direction of the roll for a given time to absorb water remaining on the roll surface. The paper was weighed with a precise spring scale before and after use of the paper and from the weight difference of the paper before and after use, that is water amount absorbed, thickness of the water film was determined using the following equation: h w (v x b x t) 1) where h is water film thickness w is weight difference of the paper before and after use (kgw), v is circumferential speed of roll b is paper towel width (mm) and t is pressing time of the paper towel Concrete measuring conditions are shown in Table 3.

Table 3 Item Specification Brand of paper towel Kleenex KF-950 Pressing area of paper towel 15 cm 2 Pressing time of paper towel 10 minutes Weight of paper towel before use 10 g Minimum scale of precise spring (digital display) 0.1 g scale (digital display) 0. g Result of measurement average of Resut _omeaureent5 measurements The above said measurement was conducted at the beginning of the test and 10, 20, 30, 40 hours after the beginning of the test and wear size of the top end 27t was measured after 40 hours and wear volume was found.

These results are shown in Figs. 32 34.

Fig. 32 shows the comparison of comparison 1 and embodiment A. Wear-resistant fluoro rubber of the same Shore hardness was used for both. It is obvious that embodiment A having an angle 81 of 1000 has thinner water film than comparison 1 having an angle 81 of 700 for both the roll center and the end of the sealing material and has better water wiping performance. For both 76 comparison 1 and embodiment A the water film is thinner at the roll center than the end of the sealing material and the difference of the water film decreases as test time passes. It is probable because the sealing material wears with roll crown and thus the difference of sealing performance decreases at the roll center and the end of the sealing material. Fig. 33 shows relationship between test time and thickness of water film attached to the roll surface of the downstream side in the roll rotating direction at the position of the roll center and the end of the sealing material for different material and hardness of the sealing material, and Fig. 34 shows effect of Shore hardness of the sealing material on wear volume (cm 3 of the sealing material after a given test time.

It is obvious from these drawings that if Shore hardness of the rubber used as the sealing material is less than 80, wear is big and thickness of water film after 10 hours is not less than 1 um and water wiping performance is reduced with increasing wear. If Shore hardness of the rubber used as the sealing material is not less than 100, it has poor transformation capability for the shape of the roll surface and thus thickness of the water film is not less than 1 pm from the beginning and produces the big scattering of water wiping performance in the axial direction of the roll, which is -77not desirable. In the case of Fig. 34, the big difference of the wear volume of the sealing material was not found between comparison 1 and embodiment A.

In Fig. 33 and Fig. 34, comparison of comparison 2 5 and embodiment A, B with said angle 81 of 1000 and different Shore hardness shows the following.

Thickness of the water film on the roll center at the beginning of test is 0.4 am regardless of material or hardness of the sealing material and water wiping performance is good. It is probable that the sealing material is put into good contact with the roll surface at the roll center having convex crown to produce good sealing effect. Thickness of the water film at the roll center, for comparison 2 4 having Shore hardness of less than 80, rapidly increases as test time increases and is not less than 1 pm after 10 hours and after that it increases, though increasing speed becomes a little slow. After 40 hours thickness of the water film becomes 1.3-2.6 pm. On the other hand, for embodiment A, B having Shore hardness of 86, 96 and comparison 5 having Shore hardness of 100, increase of thickness of water film is small with the elapse of time and even after 40 hours it remain 7 9 pm. Thickness of the water film of the sealing material at the beginning of the test is not less than 1 pm for comparison 5 having Shore hardness 105 but for comparison 2-4 and embodiment A, B it remains 78- 0.6 pm. In these cases, a trend can be seen that the smaller the Shore hardness is, the thinner thickness of the water film is, though the difference is small.

Comparing this results with the results of the roll center of the above it is probable that, since roll diameter having convex crown is a little smaller at the end of the sealing material than the roll center, transformation capability of the sealing material to the roll surface decreases a little but the sealing material having Shore hardness of less than 100 does not have big effect on water wiping performance and the sealing material having Shore hardness of not less than 100 has considerably bad effect on water wiping performance of the end because its flexibility is insufficient. (4) Thickness of the water film of the end of the sealing material rapidly increases with the elapse of test time for comparison 2-4 having Shore hardness of less than and is not less than 1 am after 10 hours and after that it increases, though increasing speed becomes a little slow. But the difference between the end and the center is gradually reduced and after 40 hours thickness of the water film remains 1.3 2.6 um as with the center. On the other hand, for embodiment 1, 2 having Shore hardness of 86, 96, thickness of the water film increases gradually with the elapse of test time and after 40 hours it remains 0.9 1 pm. But for -79- W comparison 5 having Shore hardness of 105, thickness of the water film increases gradually with the elapse of test time and the difference of thickness of the water film between the end and the center is kept almost constant. It is natural that wear volume after hours decreases as Shore hardness of the sealing material increases, but for Shore hardness of 76 86 wear volume rapidly decreases and after that it decreases gradually.

Taking into account the relationship between Shore hardness and wear volume of the above and the relationship between test time and thickness of the water film of the above together, the following can be said.

The smaller Shore hardness of the sealing material is, the faster the wearing speed is, and contact area of the sealing material and the roll surface increases rapidly. But since the pressing force of the sealing material on the roll is kept constant, pressure per unit contact area deceases as the contact area increases and thus water volume attached on the roll surface which is drawn into very small gap between the roll surface and the top surface of the sealing material by friction force of the rotating roll increases.

Therefore, as Shore hardness is smaller, the increasing speed of thickness of the water film with the W elapse of test time is bigger. But Shore hardness of less than 80 and Shore hardness of not less than 80 have different effect on wear, as if they have two different linear relations, and thus increasing speed of the water film with the elapse of test time is big (rapid) for Shore hardness of less than 80 and it is small (slow) for Shore hardness of not less than Moreover, since transformation capability of the top end of the sealing material for the convex roll crown is better as the sealing material has smaller Shore hardness and is more flexible, it seems that thickness of the water film of the end of the sealing material at the beginning of the test when the sealing material does not much wear is thinner as Shore hardness is smaller.

But it is a little thicker than thickness of the water film at the roll center. But since the sealing material wears rapidly with the elapse of test time at the roll center where the contact pressure is big, increasing speed of the water film at the roll center is a little bigger than that at the end of the sealing material.

As a result, thickness difference of the water film of the roll center and the end of the sealing material becomes almost null with the elapse of test time.

Next, a water wiping device according to the present invention was set at the upper work roll of the 81last stand, which has the fastest rolling speed in the finishing mill of the continuous hot rolling mill and on-line test was conducted changing material and hardness of the sealing material.

The test conditions are shown in Table 4 and specification of the sealing material used in the test is shown in Table 5: embodiment C, D is material suitable for the present invention and comparison 6 is material used usually.

Table 4 Item Specification Roll diameter 740 mm Roll width 2482 mm Roll crown* roll center convex, 100 um, sine curve Roll surface roughness Rmax. 2 jm Roll revolution 430 rpm Spray volume 3.75 m 3 /min Spray pressure 10 kgf/cm 2 Air pressure for bag 0.3 kgf/cm 2 Material of positioning member polyamideimide resin Seal width 1800 mm (Note) Sum of initial crown and thermal crown Table Classification Sealing Shore Angle Angle Angle Thickness material hardness a 01 02 Embodiment C eluoroe rubbe 86 780 970 50 19 mm Embodit D Wear-resistant 96 Embodiment D fluoro rubber 96 Comparison 6 Fluoro rubber 76 -82- F As for the sealing material, comparison 6 used the same fluoro rubber having Shore hardness of 76 as comparison 4 of said on-line test and embodiment C, D used the same wear-resistant fluoro rubber having Shore hardness of 86, 96 as said embodiment A, B. The sealing material 27 used in this on-line test (see Fig. 31) has the following sectional shape and size: a whole length L is 66 mm, a height of the base body 27t 1 H is 19 mm, a height of the top end 27t h is 19 mm and an angle of the top end 27t contacting with the roll surface a is 78 degrees. And it was set so that said angle 01 is 107 degrees and said angle 02 is 5 degrees.

Before beginning this test, contact condition of the top end of the sealing material and the work roll was observed with eyes for the cases of before the work roll started rotating, while the work roll was rotating and when the work roll stopped rotating after the work roll was rotating for a few minutes and it was verified that for all cases the contact condition was good and the sealing material came in almost uniform contact with the work roll also in the axial direction of the roll.

Moreover, the surface of the work roll removed after said rotating and contacting test was observed and it was verified that the black and long stain like a belt was on the section contacting the sealing material, which shows that the sealing material was put into -83uniform contact with the roll in the axial direction of the roll.

Since this test was the on-line test, thickness of the water film attached on the roll surface could not be measured as with said off-line test, but water wiping condition was observed with eyes just after the test started and while the roll used for 14 successive days was rotating and as a result it was verified that water was wiped effectively and almost uniformly in the axial direction of the roll for all cases of comparison 6 and embodiment C, D.

Wear volume of the top end of the sealing material was measured at a total of 17 points at 100 mm intervals in the axial direction of the roll after the work roll was used for 14 successive days and distribution of the wear volume in the axial direction of the roll is shown in Fig. 35 Fig. shows the case of comparison 6 having Hs of 76, Fig. 35 shows the case of embodiment C having Hs of 86, Fig. 35 shows the case of embodiment D having Hs of 96 and Fig. 36 shows total wear volume. These drawing shows the following.

Wear volume at the roll center was big and that at both ends was small because of thermal crown of the work roll for all cases. This tendency was noticeable for smaller Shore hardness of the sealing material.

84 Total wear volume of wear-resistant fluoro rubber having Shore hardness of 86 is about one-half of that of fluoro rubber having Shore hardness of 76 and total wear volume of wear-resistant fluoro rubber having Shore hardness of 96 is about a quarter of that of fluoro rubber having Shore hardness of 76. Both of them were used durably for successive 14 days which is a stoppage cycle for regular maintenance of the hot rolling mill.

But It is desirable to use the wear-resistant fluoro rubber having Shore hardness of 86, 96 from a viewpoint of wear. Moreover, taking into account the difference of wear load of the top end of the sealing material caused by the difference of the rolling speed of each stand, it is recommended that material and hardness of the sealing material be selected for each stand so that each stand has an equal or an integer-fold wearing speed of the sealing material one another and thus replacing cycle of the sealing material correspond to the stoppage cycle of the regular maintenance of the rolling mill, which is suitable for actual rolling operation.

Next, the sealing material having the following shape and size was fixed, as shown in Fig. 37: a whole length L is 66 mm, a height of the base body 27ti H is 19 mm, a height of the top end 27t h is 19 mm, an angle of the top end 27t contacting with the roll surface a is 78 degrees, said angle 81 is 107 degrees and said angle 82 is 5 degrees. This top end 27t was based on the same idea as with Fig. 29 and contact lengths of the base body 27ti and joint planes x-y and y-z were 8 mm and mm, respectively. And wear-resistant fluoro rubber having Shore hardness of 86 was used as the top end 27t and NBR having Shore hardness of 70 was used as the base body 27ti and for bonding them water-resistant and heatresistant rubber adhesive was used.

This sealing material was used for successive 14 days on the identical conditions to said on-line test conditions. The sealing material was removed after using and separation of the joined section was inspected, but no separation was seen, which verified that the sealing material composed like this bore actual using.

Moreover, the top end 27t of the sealing material was torn after using and the remaining joint plane of the base body 27ti was cleaned and the new top end 27t of the sealing material was bonded to it with adhesive and thus the top end 27t of the sealing material was reproduced. For the reproduced sealing material, online test was conducted for successive 14 days and as a result no separation of the joint plane was seen and it was proved that the reproduced one bore actual using.

Moreover, when manufacturing the sealing material 27 shown in Fig.31, manufacturing cost was -86compared for the following cases: the whole sealing material is made of wear-resistant fluoro rubber having Shore hardness of 86, (II) the top end 27t made of wearresistant fluoro rubber is bonded to the base body made of NBR with adhesive as shown in Fig. 37, (III) the whole sealing material is made of NBR, (IV) the sealing material of said (II) is reproduced after using. As a result, supposing that the manufacturing cost of is as shown in Fig. 38, the manufacturing costs of (II) and (III) are 0.20 and 0.08, respectively, and the averaged value of the two cost was 0.14, which was close to the cost (III) of 0.12, and thus the average cost of the one reproduced two times became 0.12 and was reduced to the level of the cost (III) of o.12.

In the above embodiment, NBR was used as soft rubber but the present invention is not limited to this and any kind of inexpensive rubber can be used taking into account the characteristics required according to the using conditions such as water resistance, oil resistance, heat resistance, elasticity and hardness.

In the above embodiment, wear-resistant fluoro rubber was used as hard wear-resistant rubber but the present invention is not limited to this and any kind of considerably inexpensive rubber can be used taking into account the characteristic required according to the using conditions such as water resistance, oil -87resistance, heat resistance, elasticity and hardness.

Moreover, the present invention comprising the basic structure of the device shown in Fig. 6 was described but the device comprising the structure shown in Fig. 15 is also applied for the invention.

Some embodiments according to the present invention were described but the present invention is not limited to the above embodiments and other embodiments are included in the scope of the present, if they do not depart from the spirit and scope of the present invention.

Possibility of Industrial Application In the present invention, since a pair of positioning members positioning a water wiping head by contacting with both ends of roll barrel of the work roll is provided at both ends of the water wiping head, even if the work roll diameter or pass line of the rolled material changes while the water wiping head is wiping water of the work roll, relative position relationship between the roll surface and the water wiping head can be made a constant distance and the top of end of the sealing material can be put into stable contact with the roll surface with the considerably weak pressing force in the range of the sliding stroke of the sealing material made by the expansion of the elastic bag stored in the storage box and thus produces stable -88water wiping effect.

Moreover, if the positioning member is fixed on both sides of the storage box in the axial direction of the roll and holds the sealing material on both sides, it is possible to prevent the top end of the sealing material laterally vibrating or moving sideways and to keep stable contact of the sealing material and the roll surface and to improve more stable water wiping effect.

Further, if at least one of the top and the bottom front ends of the storage box is equipped with a stopper projecting in the storage box and one side of the top and the bottom rear ends of the sealing material and opposite to said stopper is equipped with a convex projection engaging with said stopper and extending in the roll barrel direction, the sealing material is not off from the storage box owing to its own weight or friction force with the roll surface, whatever angle the storage box is in.

Further, if the storage box is removably equipped with the stopper, the sealing material can be removed easily and in a short time by removing the stopper.

Further, if at least one side of both sides of the storage box in the axial direction of the roll has its front side wall broken away except for rear part of the box storaging elastic bag and, of both positioning members, at least on positioning member on the side -89whose front side wall of the storage box is broken away is removably or pivotably fixed on the side wall, even if a stopper for preventing elastic sealing material from coming off is put on the storage box, the elastic sealing material can be sideways removed from the storage box and spare elastic sealing material can be inserted into the storage box from the side by removing or turning by 180 degrees, for example, the positioning member on the side whose front side wall of the storage box is broken away, which makes it possible to change the elastic sealing material easily and in an extremely short time on the operating side of the rolling mill.

Further, when roll cooling water of the hot rolling mill or the cold rolling mill is wiped by the present invention, it is possible to get better water wiping performance than by usual technique, to make the water film thickness on the roll after wiping maximum 3 pm, to get uniform water wiping effect in the axial direction of the roll and to keep good water wiping effect for a long time.

Furthermore, it is possible to prevent ferrous powder or scale biting between the sealing material and the roll surface, not to making much defect on the roll surface, rolled material surface and top end of the sealing material, to make the life of the sealing material longer and to use it for a successive long time in the latter stands of the finishing mill of hot rolling mill, to make the joint section of the top end of the sealing material not separated by using different material for the top end of the sealing material and the base body and by bonding the two parts properly and as a result to reduce manufacturing cost of the sealing material and further to reduce the cost by reproducing and reusing it.

-91- 92 THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS: 1 A water wiping device for a rolling mill roll, including a water wiping head positionable at a position contacting with or a position separated from a roll of a rolling mill; a supporting frame supporting said water wiping head; a supporting frame supporting means for supporting movably said supporting frame; a positioning means for positioning said water wiping head at a position contacting with or a position separated from said roll, wherein said water wiping head stores, in a storage box having an aperture in a side facing the surface of the roll, a freely expandable and elastic bag; a sealing material projecting from said aperture; a positioning member for positioning said water wiping head on the circumferential surface of the roll fixed on both sides of said storage box in the axial direction of the roll; a pressure control means for controlling pressure in said elastic bag so as to expand said elastic bag when 20 positioning said water wiping head at a water wiping position and to shrink said bag when retracting said water wiping head from the water wiping position; wherein said 00.0 positioning means is fixed on both sides of said storage box in the axial direction of the roll and holds said s* 0* 0 25 sealing material on both sides, and has a front end which S00 contacts end sections of the roll when said water wiping 0o head is in the water wiping position.

2 A water wiping device of a rolling mill roll as 30 claimed in claim 1, wherein said supporting frame supporting means has a pivot parallel to an axis of the roll and said positioning means has a hydraulic cylinder connected to the end section of said supporting frame.

3 A water wiping device of a rolling mill roll as claimed in claim 1, wherein said supporting frame supporting means is a guiding device supporting said H:\Sabene\Keep\Speci\46331-96-kawasakisteel.doc 26/11/98 i V0 l -k