US3812697A

US3812697A - Method and an apparatus of leveling a metal strip

Info

Publication number: US3812697A
Application number: US00329310A
Authority: US
Inventors: A Kamoi; K Fukuda; K Kawaguchi; Y Miyamatsu
Original assignee: Toyo Kohan Co Ltd
Current assignee: Toyo Kohan Co Ltd
Priority date: 1973-02-05
Filing date: 1973-02-05
Publication date: 1974-05-28
Anticipated expiration: 1991-05-28

Abstract

An apparatus for leveling a metal strip wherein the strip is made to travel along an elongated guide mounted on a bed. The guide has an outwardly tapered elongated central section with a plurality of guide capillaries and a flat portion at the top of the guide with recesses in the flat portion around each of the capillaries. The moving strip is supported on a fluid fed through the capillaries and is not in contact with the guide flat portion.

Description

United States Patent 1191 Kawaguchi-et al.

1. 11 3,812,697 1451 May 28,1l974 METHOD AND AN APPARATUS OF LEVELING A METAL STRIP Inventors: Kiyoshi Kawaguchi, Kudamatsu;

Yasunori Miyamatsu, Yokohama; Arao Kamoi, Kudamatsu; Kinya Fukuda, Yokohama, all of Japan Assignee: Toyo Kohan Co., Ltd.', Tokyo, Japan Filed: Feb.'5, 1973 Appl. No.: 329,310

- U.S. CL... 72/60, 72/160 Int. Cl...; B2ld l1/02 Field of Search...'..; 72/54, 56, 60, 57,160

References Cited v UNITED STATES PATENTS Ferchland 72/60 3,559,438 2/1971 Rouyeretai. .,.;..72/160 3,587,598. 6 1971 Miyamatsuetal...'..' 134/122 Primary Examiner- Richard J. Herbst Attorney, Agent, or Firm-George B. Oujevolk [5 7] ABSTRACT Y An apparatus for leveling a metal strip wherein the strip is made to travel along an elongated guide mounted on a bed. The guide has an outwardly tapered elongated central section with aplurality of guide capillaries and a flat portion at the top of the guide with recesses in the Hat portion around each of the capillaries. The moving strip is supported on a fluid fed through the capillaries'and is not in contact with the guideflat portion. 1

11 Claims, '21 Drawing Figures Pmmanmzemn $812,697

saw 03 OF 10 mmmwz m4 3812.697

.sum as or 10 FIG." I 15 16 PATENTEDm 28 1914 sum 07 or 10 METHOD AND AN APPARATUS or LEVELING A METAL STRIP BACKGROUND OF THE INVENTION BRIEF DISCUSSION OF THE PRIOR ART Manufacturing of a metal strip involves several processes such as rolling, annealing and tempering. As the metal strip is processed, defects concerning the shape of the metal strip, such as guttering, curling, edge wave, full center and quarter buckle appear. These defects are not only obstacles in the following processes, but

also a large factor to lower the quality standard of the products for which the metal strip is used. Therefore, it is necessary for the metal strip to be leveled by using a leveler. Generally, in processing the Ieveler, the metal strip is bent plastically several times under tension by work rolls. During leveling,the 'metal strip is elongated plastically around 0.3 to 1.5 percent and the plastic elongation corrects the shape defects of the metal strip. The mechanical tension leveler is a known apparatus for leveling.

It is known generally that when leveling a metal strip by a mechanical tension-leveler the use of work rolls of as a smalldiameter as possible helps to reduce the ten-' sion required to-correct shape defects of the metal of the work roll in theconventional mechanical tension leveler, the mechanism of supporting the work rolls is complicated and the number of the bearings of back up rollswill increaseto support the work rolls. Other difficulties appear such as stains on the surface of the metal strip due to leakage of oil out of the bearings and scratches on the surface due to undesirable vibration by deteriorating accuracy of machine elements assembled. Also, there isthe difficulty of reducing the work roll diameter. Even though the mechanism of supporting the small work rolls isprovided, the number of rotations of the small work roll becomes considerably larger than that of the regular work roll for the same traveling speed of the metal strip, which causes sticking of the bearings and shortens the life of the work rolls. Therefore, it is very difficult technically to use extremely small work rolls in the conventional mechanical tension leveler. Large tension is required to correct shape defects of the metal strip, which means large scale bridles have to be installed before and after the leveler. Further, it is very difficult to practically correct shape defects of cold rolled steel strip of around 0.1 mm thick.

In-all conventional mechanical tension levelers, work rolls have been used to bend the metal strip and correct its shape defects. Tension is added tomake the metal strip fit the surface of the work roll and improve the effect of leveling. Almost all defects in the conventional mechanical tension leveler described above are caused by the use of the-work rolls. If the metal strip is supported out of contact by fluid film and bent without using the work rolls-defects in theconventional mechanical tension leveler can be substantially avoided. One of the prior art-methods of supporting a strip by a stationary guide and handling it without causing surface defects is foil hearing. In this case, materials such as plastic film metal foil and paper of around 0.3 mm to 0.5 mm thick are used. The stiffness of foil is negligibly small compared to that of the metal strip to be lev-.

eled and the load capability of the foil bearing is extremely small. Further, the object of foil bearing is not to level the'metal strip. I

Other prior art arrangements are described in US. Pat. No. 3,587,598 Sink roll for supporting an elon gate material without direct contact" and British Pat.

No. 1,016,703 Improvements relating to fluid pressure support bearings. But .these patents relate to a technique of supporting the metal strip out of contact and guiding it in a continuous treatment line. Therefore the object of these arrangements above is different from the present invention.

OBJECT OF THE INVENTION Accordingly, it is an object of the present invention to provide a method and apparatus for leveling. a metal strip in which work rolls are not used and therefore complicated mechanism is not necessary to support the work rolls like in the l leveler.

It is another object of the present invention to provide a method and apparatus for leveling a metal strip provide a method and apparatus for leveling the metal I strip in which no scratch is caused to appear on the surface of the metal strip.-

It is yet a further object of the present invention to', provide an apparatus for leveling the metal strip which i does not have any bearing in the mechanism.

Again, it is an object of the present invention to provide an apparatus for leveling the metal strip which does not have a limited life of the work rolls in the conventional mechanical tension leveler.

Also, it is an object of the present invention to provide a method and apparatus for leveling the metal strip which does not have any upper limitations on traveling speed of a metal strip like cal tension leveler.

SUMMARY OF THE INVENTION Briefly speaking, the principle of leveling of a metal strip by the present invention is that a traveling metal strip having shape defects is supported out of contact in'the conventional mechaniwith the surface of a supporting guide, which does not I have any rotary part, by a pressure film of liquid and is bent under tension by the supporting guides, and shape defects of the metal strip are corrected.

The invention as well as other objects and advantages thereof, will be more apparent from the following detailed description when taken together withthe accompanying drawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a supporting guide according to the present inventive concept;

conventional mechanical tension FIG. 2 is a cross-sectional view-through .FIG. I along line .I I;

FIG. 3 is a cross-sectional view along line II II of FIG. 1;

FIG. 4 is a perspective view of another type of sup- I porting guide according to the inventive concept;

FIG. 5 is a cross-sectional view taken along lines III I in in FIG. 4;

a FIG. 6 is also a perspective view of still another type of supporting guide accordingto the inventive concept;

FIG. 7 is a cross-sectional view along lines IV IV of FIG/6;

FIG. 8 presents yet another perspective view of yet FIG. 13 is also a cross-sectional view' of a different configuration for some of the components for FIGS. 1, 4and'6; l

FIG. 14 is a perspective view of a'component used with the-embodiment of FIG. 8;

FIG. 15'is a cross-sectional view taken alon'g lines VII VII of FIG. 14;

FIG; 16 shows a perspective view of the assembly of thecom'ponents in FIGS. 1 and 10;

FIG. 17 is a cross-sectional view taken along VIII VIII of FIG. 16;

FIG. 18 is an'explanation view of one version of a working section of a complete unit;

lines FIG. 19 is another version of an explanation of a working'section of a complete unit; I

FIG. 20 is a schematic version of a complete unit; and,

' FIG. 21 is a schematic explanation of another version of acompleteunit.

' DETAILED DESCRIPTION FIG. 1 shows a perspective view of a supporting guide 1 with capillary 8. FIG. 2 is a cross-sectional view taken along the line I I through capillary 8 in FIG. 1 with a metal strip 28. FIG. 3 is across-sectional view taken along the'line ll ll through a hole40 in FIG. 1. A top surface of the supporting guide 1 consists of a flat portion 36 andtwo curved portions 37. A row of capillaries 8 are provided through the supporting guide 1 to supply pressurized liquid. The capillary 8 has. an opening 4 around which a recess 3 is provided on theflat portion 36. The capillary 8 has another opening at the bottom'of the supporting guide l.,PluraI holes 40 are drilled to measure pressure of a liquid film between the top service and the metal strip 28 to .be leveled. The hole 40 has an opening'6 on the flat surface 36 and another opening 9 on the side ofIthe supporting guide 1 to connect to a pressure gage. Plural stepped holes 5 are drilled to fix the supporting guide I to a bed 2 (see FIG. 10). I I I I I The principle of leveling a metal strip by the present invention is that the traveling metal strip is bent under tension by the top-surface of the supporting guide 1 comprising thellat portion 36 and the two curved portions 37. Pressurized liquid llowsinto the clearance formed between the traveling metal'strip 28 and the curved portions 37 pressurized liquid film formed be tween the traveling metal strip 28 andthewp-surface I of the supporting guide .1 prevents the metal strip 28 from contacting directly with the'supporting guide 1 and shape defects of the traveling metal strip 28 are corrected. I

In FIG. 4 which is another type of a supporting guide 1, a fin 10 (see FIG. 5), made of flexible material is at- I tached on each curved portion 37. The shape of the fin l0 deforms naturally so that pressurized liquid film is formed in the clearance between the metal strip 28 and I the top surface of thesupporting guide 1.

In FIG. 6 and FIG. 7 the whole top 11 of the supporting guide 1 is made of material, such as rubber-and plastic, having lower elasticity than of the metal. As shown in FIG. 7, the shape of the top surface does not need to be curved. Except for the top of the supporting, guide 1, the rest of the 38 between the two rows of recesses 4 forms two flat portions 36a. In the embodiments given in FIG. I to 9, the capillaries 8 can be replaced withholes having an orifice.

FIG. 10 and 11 are views of a bed 2 on which the supporting guides] in FIG. 1, land 6 are put. The bed 2 contains a chamber 15 inside. An entrance hole l6is provided to introduce pressurized .liquid from pressure to the chamber 15 and plural holes 14 are drilled to supply pressurized liquid to the capillaries 8 in the supporting guide 1. O-rings 13 are used between the holes 14 and the capillaries 8 to prevent leakage of pressur ized liquid at the joint. Plural holes 12 are threaded to fix the supporting guide 1 to the bed 2. I

FIG. 12 is a cross-sectional view of abed 2 having an-.

other arrangement for the chambers 15 for the supporting guide 1 in FIGS. 1, 4 and 6. Large-chambers l5 and small chambers 42 are divided longitudinally by plural partitions l7 and each

chamber

15 or 42 has independently an

entrance hole

16 or 43 forpressurized liquid I and at leastone hole-1410 supply'pressurized liquid to the capillaries 8. In this type of bed 2, the supplyof pressurized liquid to the outer chamber 15 can be stopped to save unnecessary flow rate of liquid when a narrow metal strip is leveled and also the pressure and flow rate of the pressurized liquid to the respective chamber 15 can be changed to correct shape defects of the metal strip effectively.

4 FIG. 13 shows another configuration of the chamber 15 for the supporting guide 1 in FIGS. 1, 4 and 6. In this example, the chamber 15 forms a cylinder. At both ends of cylindrical chamber 15, apair of pistons 19 are provided having a piston rod 18 and O-ring 20. The pis-' tons 19 are movable and can change the length of the chamber 15 continuously corresponding to the width of a metal strip to be leveled and so power of the pressure source can be saved.

In FIG. 14 and FIG. 15', the bed 2 contains a of chambers 15b whicbhave two rows of entranceholes 16 of pressurized-liquid and holes 14 to the capillaries 8 of the supporting guide I in FIG. 8. For the assembly comprising the supporting guide I in FIG. 8 and the bed2 in FIG. 14, two systems of pressure sources are necessary to supply pressurized liquid into the chambers' b separately.

FIG. 16 and FIG. 17 shows how an assembly in which the supporting guide 1 in FIG. 1 and the bed 2 in FIG. 10 are put together by screws 7. The joint between the hole 14 and the capillary 8 is sealed by O-ring 13. The other types of supporting guides 1 and the bed 2, similar to FIGS. 16 and 17 can be assembled in the same way.

FIG. 18 is an example of the leveling unit of the metal stripcomprising the supporting guides l and the bed 2.

The metal strip 28 is guided to pass between the top surfaces of the supporting guide 1 which is adjusted above and below by the screw 22 and of the other supporting guide 1 fixed to a lower frame 21. Two deflector rolls 24 adjustable above and below by screws 22 are disposed before and after the supporting guides 1. The supporting guides l and the deflector rolls 24 may be adjusted by using the other known mechanism than screws 22. A discharging conduit pipe 27 is connected to the lower frame 21 and supply conduit pipes 23 are to the supporting guides .1.

'The leveling unit operates as follows:

The supporting guides l are positioned to bend the metal strip 28'traveling under tension and at the same time, pressurized liquid is supplied to the supporting guide 1 from the pressure source which is set to supply the liquid under proper pressure and of proper flow rate, and flows out through the clearance 41 between the traveling metal strip 28 and the top surface of the supporting guide 1. The wrap angle of the metal strip 28 along the top surface of the supporting guide 1 can be changed by adjusting the position of the deflector rolls 24..Non-contact between the traveling metal strip 28 and the curved portion 37 of the supporting guide 1 along which pressurized liquid flows outwardly can be attained by adjusting the wrap angle. The traveling metal strip 28 under tension is subjected to bending by the supporting guide 1 out of direct contact and is elongated plastically, and the shape defects of the metal strip are corrected. b

FIG. 19 is another example of the leveling unit comprising the supporting guide 1 and the bed 2. The bed 2 is mounted on a rotary part 25 which has a cylindrical convex surface to slide on a seat 26. The seat 26 has a cylindrical concave surface. One of the seats 26 is fixed to the lower frame 21 and two other seats 26 are provided onto the upper frame 30 and adjusted above and below by screws 22. The supply conduit pipe 23 of pressurized liquid is connected to each'bed 2. The other known device besides the rotary part 25, the seat 26 and the screw 22 can be 'used to change the wrap angle andthe position of the supporting guide 1.

FIG. 20 is an example of a leveler comprising the leveling unit shown in FIG. 18 or 19. The metal strip 28 vention is operated in the similar way of the conventional mechanical tension leveler. Because no work roll is used in the leveler of the present invention, radius of curvature of bent metal strip by the supporting guide 1 can be extremely small. Therefore tension required to elongate the metal strip plastically for correcting shape defects can be reduced. In FIG. 20 the capacity of the front bridle 32 and the back bridle 33 can be small. When only small tension is required, even the bridles used previously in the processing system can be utilized and there is not need to use a new bridle for the leveling unit of the present invention. The entire system is shown in FIG. 21. As pressurized liquid, any kind of liquid can be used like water, lubrication fluids and so on which are used presently in the production line. The leveling unit of the present invention has no rotary parts like work rolls in the conventional mechanical tension leveler and therefore the traveling speed of the metal strip is not limited.

Table 1 shows the sesult of leveling a metal strip by using the present invention. Theleveler of the present invention makes it easy to correct the shape defects of extremly thin and high yield stress metal strip which was very difficult to correct by the conventional mechanical tension leveler.

TABLE 1 Width of flat portion (36) 2.5mm Radius of curved portion (37) 2.5mm

Number of supporting guides (1) 3 Front tension between (32) and It will be understood that various changes and modiflcations can be made in the structures described which provide the characteristics of this invention without departing from the spirit thereof particularly. as defined in I the following claims.

We claim: 1. An apparatus for leveling metal strip material held under tension to correct shape defects therein, said apparatus comprising an elongated supporting guide having a wide base, a narrow flat top portion relative to said base, tapered sides extending upwardly from said wide base to said narrow flat top portion, curved portionsformed atthe juncture of said tapered sides and said narrow flat top portion, said curved portions forming supporting surfaces for tensioned metal strip material bent over said top portion, recesses formed in said flat top portion, a row of capillaries extending upwardly from said wide base in communication with said recesses in said narrow flat top portion, means connected to said elongated supporting guide to supply pressurized fluid to said capillaries extending to said recesses in said flat top portion to impinge against said tensioned metal strip material while holding said metal strip out of contact with said flat top portion to level and correct shape defects in said metal strip.

2. A supporting guide (1) for leveling the metal strip as claimed in claim 1 wherein there are two rows of capillaries (8) for supplying pressurized liquid provided to said flat portion (36), a slender recess (3) is provided at an exit port (4) of said each capillary (8) and a long low projection (38) is provided between two rows of said recesses (3) on said flat portion (36).

3'. A supporting guide (1) for leveling the metal strip as claimed in claim 1, wherein a fin (10) made of flexible material is attached on each of said curved portion 4. A supporting guide (1) for leveling the metal strip as claimed in claim 1, the top of said supporting guide (1) ismade of material having lower elasticity than that of the metal.

5. A supporting guide (1) for leveling the metal strip as claimed in claim 2, wherein the top of said supporting guide (1) is made of material having lower elasticity said capillaries in the supporting guide to provide pres-' least one hole in each said cham her which connect with said capillaries in said supporting guides to supply pressurized liquid thereto.

8. An apparatus as claimed in claim 6, and further including a movable pistonextending into said bed chamber to vary the effective length of said chamber.

9. The apparatus as defined in claim 1, wherein two chambers are provided in said bed, each having an independent entrance hole through which pressurized liquid is introduced thereinto, means in said bed forming two rows of holes to connect with plural rows of capillaries in said supporting guides to supply pressurized liquid thereto. v

10. The combination as defined in claim 9, wherein said plural chambers are further divided longitudinally in said bed, each chamber so divided having an independent entrance hole to introduce pressurized liquid thereinto and each having at least one hole which connects with the capillaries in the supporting guide to which pressurized fluid is provided.

11. The combination as claimed in claim 9 wherein a pair of pistons are provided in said chambers, one piston extending into a said respective chamber from each hole through which pressurized is introduced, and at fective length of said chamber.

Claims

1. An apparatus for leveling metal strip material held uNder tension to correct shape defects therein, said apparatus comprising an elongated supporting guide having a wide base, a narrow flat top portion relative to said base, tapered sides extending upwardly from said wide base to said narrow flat top portion, curved portions formed at the juncture of said tapered sides and said narrow flat top portion, said curved portions forming supporting surfaces for tensioned metal strip material bent over said top portion, recesses formed in said flat top portion, a row of capillaries extending upwardly from said wide base in communication with said recesses in said narrow flat top portion, means connected to said elongated supporting guide to supply pressurized fluid to said capillaries extending to said recesses in said flat top portion to impinge against said tensioned metal strip material while holding said metal strip out of contact with said flat top portion to level and correct shape defects in said metal strip.

3. A supporting guide (1) for leveling the metal strip as claimed in claim 1, wherein a fin (10) made of flexible material is attached on each of said curved portion (37).

4. A supporting guide (1) for leveling the metal strip as claimed in claim 1, the top of said supporting guide (1) is made of material having lower elasticity than that of the metal.

5. A supporting guide (1) for leveling the metal strip as claimed in claim 2, wherein the top of said supporting guide (1) is made of material having lower elasticity than that of metal.

6. In combination with the apparatus as claimed in claim 1, a bed attached to the bottom of said supporting guide, means in said bed forming a chamber, an entrance hole formed in said bed chamber whereby pressurized liquid may be introduced thereinto and plural holes are formed in said bed chamber to connect with said capillaries in the supporting guide to provide pressurized liquid thereto.

7. An apparatus as claimed in claim 6, wherein plural longitudinally divided chambers are formed in said bed, each bed chamber having formed therein an entrance hole through which pressurized is introduced, and at least one hole in each said chamber which connect with said capillaries in said supporting guides to supply pressurized liquid thereto.

8. An apparatus as claimed in claim 6, and further including a movable piston extending into said bed chamber to vary the effective length of said chamber.

9. The apparatus as defined in claim 1, wherein two chambers are provided in said bed, each having an independent entrance hole through which pressurized liquid is introduced thereinto, means in said bed forming two rows of holes to connect with plural rows of capillaries in said supporting guides to supply pressurized liquid thereto.

11. The combination as claimed in claim 9 wherein a pair of pistons are provided in said chambers, one piston extending into a said respective chamber from each end of said bed, said pistons serving to change the effective length of said chamber.