Side trimming equipment and side trimming method

Abstract

To provide a side trimming facility and a side trimming method capable of effectively preventing blade chipping due to impact caused by fluttering of a metal strip regardless of the thickness of the metal strip.SOLUTION: A side trimming facility 1 comprises upper pressing rings 21a, 21b and lower pressing rings 22a, 22b for holding a metallic strip S by sandwiching it from above and below on an upstream side of a pair of side trimmers 10a, 10b in an advancing direction (direction shown by an arrow A) of the metallic strip S. The upper pressing rings 21a, 21b and the lower pressing rings 22a, 22b are disposed out of alignment in the advancing direction of the metallic strip S, and either or both of the upper pressing rings 21a, 21b and the lower pressing rings 22a, 22b are disposed so as to push the metallic strip S in a normal direction from a pass line PL.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to side trimming equipment and a side trimming method for shearing both edges in the width direction of a metal strip.

Background Art

[0002] In a production line for manufacturing a metal strip such as an annealing line after cold rolling, for the purpose of removing irregularities in the shape of the end portions in the width direction of the manufactured metal strip or aligning the width of the metal strip with the product dimensions, etc., an operation (shearing operation) of cutting off both edge portions in the width direction of the metal strip by side trimming equipment is generally performed. This side trimming equipment includes a pair of side trimmers provided on both sides in the width direction of the metal strip conveyed on the pass line. Each side trimmer has an upper blade and a lower blade for shearing the edge portions in the width direction of the metal strip conveyed on the pass line. [[ID=^{13}]] It is generally performed. This side trimming equipment includes a pair of side trimmers provided on both sides in the width direction of the metal strip conveyed on the pass line. Each side trimmer has an upper blade and a lower blade for shearing the edge portions in the width direction of the metal strip conveyed on the pass line.

[0003] [[ID=1^{5}]] The upper blade or the lower blade of each side trimmer may cause chipping due to wear or impact, resulting in a decrease in the shearing ability and causing quality defects such as rough ears at the shearing portion. As a countermeasure against chipping of the upper blade and the lower blade in the side trimmer, conventionally, for example, those shown in Patent Documents 1 to 3 are known.

[0004] The cutting tool shown in Patent Document 1 is a cutting tool composed of a composite material containing a ceramic phase and a metal phase. The cutting edge portion of the cutting tool has a cutting edge ridge line and a cutting edge forming surface constituting the cutting edge ridge line. The cutting edge forming surface has a surface portion in which the ceramic phase protrudes from a composite material layer having a ceramic phase and a metal phase, the ceramic phase exists intermittently, and the metal phase is absent. And the roughness of the surface portion satisfies the arithmetic mean roughness Ra≤0.1 μm and the skewness Rsk≤-0.01.

[0005] According to the cutting tool shown in Patent Document 1, a cutting tool having good anti-welding properties and smoothness can be obtained. Furthermore, the method for applying cutting oil to a trimmer blade shown in Patent Document 2 is a method for applying cutting oil to a trimmer blade in a side trimmer device that shears the edge portion of a steel plate, in which cutting oil in a mist form is sprayed onto the shearing corner portion of the trimmer blade.

[0006] According to the method for applying cutting oil to a trimmer blade shown in Patent Document 2, cutting oil can be accurately applied to the shearing corner of the rotating trimmer blade, and cutting dust adhering to the surface of the trimmer blade can be effectively removed. This prevents cutting dust and debris generated when shearing steel plates from adhering to the trimmer blade and causing chipping of the blade.

[0007] Furthermore, the metal strip plate retaining ring for a side trimmer shown in Patent Document 3 is provided on the inside of each of the upper and lower disc-shaped blades of the side trimmer, adjacent to the disc-shaped blades, and the plate retaining ring is provided adjacent to the disc-shaped blades, with a cylindrical portion on the side adjacent to the disc-shaped blade and a tapered portion at its tip.

[0008] According to the metal strip side trimmer plate holder ring shown in Patent Document 3, when performing side trimming of a metal strip with a disc-shaped blade, the metal strip can be held down with the plate holder ring to suppress flapping or lifting of the metal strip, thereby preventing a deterioration in the quality of the cut shape of the metal strip. [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] International Publication No. 2019 / 65677 [Patent Document 2] Japanese Patent Publication No. 2005-153116 [Patent Document 3] Japanese Patent Application Publication No. 11-277325 [Overview of the project] [Problems that the invention aims to solve]

[0010] However, the cutting tool shown in Patent Document 1, the method for applying cutting oil to a trimmer blade shown in Patent Document 2, and the metal strip side trimmer plate retaining ring shown in Patent Document 3 had the following problems. In other words, the cutting tool shown in Patent Document 1 improves the adhesion resistance and smoothness of the blade itself to prevent minute chipping caused by wear, but it is not effective against chipping caused by impact.

[0011] Furthermore, the method of applying cutting oil to the trimmer blade shown in Patent Document 2 is effective in preventing minute chipping caused by wear and in preventing cutting dust and debris generated when shearing steel plates from adhering to the trimmer blade, but it is not effective against chipping caused by impact. Here, chipping due to impact refers to chipping that occurs on the trimmer blade due to impact applied to the trimmer blade, and this impact is mainly caused by the flapping of the metal strip.

[0012] According to the metal strip side trimmer plate retaining ring shown in Patent Document 3, when performing side trimming of a metal strip, the metal strip can be held down with the plate retaining ring to suppress flapping of the metal strip.

[0013] However, in the metal strip side trimmer plate pressing ring shown in Patent Document 3, the upper pressing ring, which is provided inside the upper disc-shaped blade, and the lower pressing ring, which is provided inside the lower disc-shaped blade, are arranged in a straight line in the direction of metal strip movement. As a result, the upper pressing ring and the metal strip make linear contact, and the lower pressing ring and the metal strip make linear contact to press down on the metal strip. In this case, the contact area between the upper and lower pressing rings and the metal strip is small, resulting in a small effect in suppressing metal strip flapping and not effectively preventing blade chipping caused by impact due to metal strip flapping. In particular, the effect of suppressing flapping is small for thin metal strips (for example, with a plate thickness of about 0.8 mm).

[0014] The present invention was made to solve these conventional problems, and its objective is to provide a side trimming apparatus and a side trimming method that can effectively prevent chipping of the blade due to impact caused by flapping of the metal strip, regardless of the thickness of the plate. [Means for solving the problem]

[0015] To solve the above problems, a side trimming apparatus according to one aspect of the present invention comprises a pair of side trimmers installed on both sides in the width direction of a metal strip traveling along a pass line, wherein one of the pair of side trimmers has an upper blade and a lower blade for shearing one edge of the metal strip in the width direction, and the other of the pair of side trimmers has an upper blade and a lower blade for shearing the other edge of the metal strip in the width direction, wherein the apparatus comprises an upper pressing ring and a lower pressing ring that hold the metal strip from above and below on the upstream side of the pair of side trimmers in the direction of travel of the metal strip, the upper pressing ring and the lower pressing ring are positioned offset from each other in the direction of travel of the metal strip, and either one or both of the upper pressing ring and the lower pressing ring are positioned to push the metal strip in the direction normal to the pass line.

[0016] Furthermore, another aspect of the present invention relates to a side trimming method comprising a pair of side trimmers installed on both sides in the width direction of a metal strip traveling along a pass line, wherein one of the pair of side trimmers has an upper blade and a lower blade for shearing one edge of the metal strip in the width direction, and the other of the pair of side trimmers has an upper blade and a lower blade for shearing the other edge of the metal strip in the width direction, and the side trimming method comprises side trimming equipment that shears both edges of the metal strip in the width direction, wherein when the upper blade and lower blade of one side trimmer and the other side trimmer shear both edges of the metal strip traveling along the pass line, the metal strip is held from above and below on the upstream side of the pair of side trimmers in the direction of travel of the metal strip, and either or both of the upper and lower pressing rings, which are positioned offset in the direction of travel of the metal strip, push the metal strip in the direction normal to the pass line. [Effects of the Invention]

[0017] According to the side trimming equipment and side trimming method of the present invention, regardless of the thickness of the plate, it is possible to effectively prevent chipping of the blade due to impact caused by flapping of the metal strip. [Brief explanation of the drawing]

[0018] [Figure 1] This diagram shows the schematic configuration of a side trimming device according to the first embodiment of the present invention, as viewed from the left side of a metal strip. [Figure 2] This is a cross-sectional view along line 2-2 in Figure 1. [Figure 3] Figure 1 shows the side trimming equipment as viewed from the front of the metal strip. However, in Figure 3, the left side trimmer, left upper retaining ring, and left lower retaining ring, and the right side trimmer, right upper retaining ring, and right lower retaining ring are shown retracted in the width direction of the metal strip. [Figure 4]The upper pressing ring in the side trimming equipment shown in FIG. 1 is shown. (a) is a view of the left upper pressing ring seen from the left side of the metal strip, and (b) is a view of the left upper pressing ring seen from the front side of the metal strip. [Figure 5] The lower pressing ring in the side trimming equipment shown in FIG. 1 is shown. (a) is a view of the left lower pressing ring seen from the left side of the metal strip, and (b) is a view of the left lower pressing ring seen from the front side of the metal strip. [Figure 6] It is a view of the schematic configuration of the side trimming equipment according to the second embodiment of the present invention seen from the left side of the metal strip. [Figure 7] It is a cross-sectional view taken along the line 7-7 in FIG. 6. [Figure 8] It is a view of the side trimming equipment shown in FIG. 6 seen from the front side of the metal strip. However, in FIG. 8, the left side trimmer, the left upper pressing ring, and the left lower pressing ring, and the right side trimmer, the right upper pressing ring, and the right lower pressing ring are shown in a state of being retracted in the width direction of the metal strip.

Embodiments for Carrying Out the Invention

[0019] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The embodiments shown below are examples of devices and methods for embodying the technical idea of the present invention, and the technical idea of the present invention does not specify the materials, shapes, structures, arrangements, etc. of the components in the following embodiments. Also, the drawings are schematic. Therefore, it should be noted that the relationship between the thickness and the planar dimensions, the ratio, etc. are different from the actual ones, and there are also parts where the dimensional relationships and ratios between the drawings are different from each other.

[0020] (First Embodiment) FIG. 1 shows a state in which the schematic configuration of the side trimming equipment according to the first embodiment of the present invention is seen from the left side of the metal strip. The side trimming equipment 1 shown in Figure 1 is used in the annealing line after cold rolling to cut off (shear) both edges in the width direction of the rolled metal strip S for purposes such as removing irregularities in the shape of the widthwise end of the metal strip S or making the width of the metal strip S match the product dimensions.

[0021] This side trimming equipment 1 is equipped with a pair of side trimmers 10a and 10b installed on both sides of the width direction (the direction perpendicular to the plane of the paper in Figure 1, and the left-right direction in Figures 2 and 3) of the metal strip S that moves along the pass line PL in the direction indicated by arrow A. The left (one) side trimmer 10a has an upper blade 11a and a lower blade 12a that shear the left (one) edge in the width direction of the metal strip S as it moves along the pass line PL, as shown in Figure 2. The right (other) side trimmer 10b has an upper blade 11b and a lower blade 12b that shear the right (other) edge in the width direction of the metal strip S as it moves along the pass line PL.

[0022] Here, the upper blade 11a and lower blade 12a of the left side trimmer 10a are circular blades, and are detachably attached to an upper drive shaft (not shown) and a lower drive shaft (not shown), respectively, which are rotatably supported in a left-side housing (not shown), thus forming a rotating blade. Similarly, the upper blade 11b and lower blade 12b of the right side trimmer 10b are circular blades, and are detachably attached to an upper drive shaft (not shown) and a lower drive shaft (not shown), respectively, which are rotatably supported in a right-side housing (not shown), separate from the left-side housing mentioned above, thus forming a rotating blade.

[0023] The lower blades 12a and 12b of the left side trimmer 10a and the right side trimmer 10b are positioned on the inside in the width direction of the metal strip S, as shown in Figure 2. The upper blades 11a and 11b of the left side trimmer 10a and the right side trimmer 10b are positioned on the outside in the width direction of the metal strip S relative to the lower blades 12a and 12b, forming the cutting edge. When shearing both edges of the metal strip S in the width direction, the lower blades 12a and 12b support the metal strip S, while the upper blades 11a and 11b are responsible for shearing and cracking the metal strip S. When the metal strip S enters the left side trimmer 10a and the right side trimmer 10b, the upper blades 11a and 11b and the lower blades 12a and 12b initially bite into the metal strip S, but the edges of the metal strip S are sheared by the upper blades 11a and 11b.

[0024] Furthermore, as shown in Figure 3, the left side trimmer 10a and the right side trimmer 10b are retracted to the outside in the width direction of the metal strip S when the widthwise edges of the metal strip S are not being sheared. When shearing the widthwise edges of the metal strip S, the left and right housings are moved inward in the width direction of the metal strip S, as indicated by arrow B, and the left side trimmer 10a and the right side trimmer 10b are moved inward in the width direction of the metal strip S to shear the widthwise edges of the metal strip S.

[0025] Furthermore, the side trimming equipment 1 is equipped with upper pressing rings 21a, 21b and lower pressing rings 22a, 22b that hold the metal strip S from above and below, upstream of a pair of side trimmers 10a, 10b in the direction of travel of the metal strip S.

[0026] As shown in Figure 3, the upper retaining rings 21a and 21b are installed in pairs on both sides of the metal strip S in the width direction, forming the left upper retaining ring 21a and the right upper retaining ring 21b. Similarly, the lower retaining rings 22a and 22b are also installed in pairs on both sides of the metal strip S in the width direction, forming the left lower retaining ring 22a and the right lower retaining ring 22b.

[0027] By installing a pair of upper retaining rings 21a, 21b and lower retaining rings 22a, 22b on both sides in the width direction of the metal strip S, both ends of the metal strip S in the width direction can be stably held by being sandwiched from above and below on the upstream side of the pair of side trimmers 10a, 10b in the direction of travel of the metal strip S.

[0028] Furthermore, by installing a pair of upper retaining rings 21a, 21b and lower retaining rings 22a, 22b on both sides in the width direction of the metal strip S, when the widthwise edges of the metal strip S are not being sheared, the upper retaining rings 21a, 21b and lower retaining rings 22a, 22b are retracted to the outside in the width direction of the metal strip S. Also, when the widthwise edges of the metal strip S are being sheared, the upper retaining rings 21a, 21b and lower retaining rings 22a, 22b can be moved inward in the width direction of the metal strip S to hold the vicinity of both ends in the width direction of the metal strip S.

[0029] Thus, the device includes upper retaining rings 21a, 21b and lower retaining rings 22a, 22b that hold the metal strip S from above and below, upstream of the pair of side trimmers 10a, 10b in the direction of travel of the metal strip S. This makes it possible to suppress flapping of the metal strip S when shearing both edges of the metal strip S in the width direction by the pair of side trimmers 10a, 10b.

[0030] However, as mentioned above, when shearing both edges of the metal strip S in the width direction, the lower blades 12a and 12b support the metal strip S, while the upper blades 11a and 11b form the cutting edges and are responsible for cracking to shear and break the metal strip S. At this time, the upper blades 11a and 11b that form the cutting edges push the edges of the metal strip S downward, so the upper blades 11a and 11b are subjected to a normal force and a lateral force due to friction between the metal strip S and the upper blades 11a and 11b. For this reason, the upper blades 11a and 11b that form the cutting edges are prone to being subjected to a large load and are likely to chip. In such cases, if the incidence of the metal strip S on the upper blades 11a and 11b that form the rotating blades is from above the pass line PL, the force on the upper blades 11a and 11b will increase further, which may result in further chipping.

[0031] Therefore, in the side trimming equipment 1 of this embodiment, firstly, the upper retaining rings 21a, 21b and the lower retaining rings 22a, 22b are positioned offset in the direction of travel of the metal strip S. Specifically, as shown in Figure 1, the left upper retaining ring 21a is positioned downstream of the left lower retaining ring 22a in the direction of travel of the metal strip S, where the pair of side trimmers 10a, 10b are located. The distance of the offset in the direction of travel between the left upper retaining ring 21a and the left lower retaining ring 22a is the distance Δ between their centerlines.

[0032] Furthermore, the right upper retaining ring 21b is positioned downstream of the right lower retaining ring 22b in the direction of travel of the metal strip S, where the pair of side trimmers 10a, 10b are located. The displacement distance between the right upper retaining ring 21b and the right lower retaining ring 22b in the direction of travel is the distance Δ between their centerlines. These distances Δ are appropriately determined according to the diameters of the upper retaining rings 21a, 21b and the lower retaining rings 22a, 22b and the thickness of the metal strip S.

[0033] Secondly, the upper retaining ring 21a on the left and the upper retaining ring 21b on the right are positioned to push the metal strip S downward from the pass line PL where the lower blades 12a and 12b are located.

[0034] In this manner, the upper pressing rings 21a, 21b and the lower pressing rings 22a, 22b are positioned offset from each other in the direction of travel of the metal strip S. Furthermore, the upper pressing rings 21a, 21b are positioned to push the metal strip S downward from the pass line PL where the lower blades 12a, 12b are located. As a result, the upper pressing rings 21a, 21b and the metal strip S make surface contact, and the lower pressing rings 22a, 22b and the metal strip S make surface contact, pressing down on the metal strip S. This increases the contact area between the upper pressing rings 21a, 21b and the lower pressing rings 22a, 22b and the metal strip S compared to the case of line contact, thereby greatly increasing the effect of suppressing the flapping of the metal strip S. Furthermore, by pushing the metal strip S downward from the pass line L using the upper retaining rings 21a and 21b, the incidence of the metal strip S on the upper blades 11a and 11b that constitute the rotating blade is from below the pass line PL, thus preventing an increase in the force applied to the upper blades 11a and 11b. Therefore, it effectively prevents chipping of the blades due to impact caused by the fluttering of the metal strip S, and regardless of the thickness of the metal strip S, it is possible to effectively prevent chipping of the blades due to impact caused by the fluttering of the metal strip S.

[0035] Here, the amount by which the left upper retaining ring 21a and the right upper retaining ring 21b push the metal strip S downward from the pass line PL, that is, the amount of downward movement δ of the left upper retaining ring 21a and the right upper retaining ring 21b from the pass line PL, is appropriately determined according to the strength, thickness, width, amount of shape change in the direction of travel at both edges in the width direction of the metal strip S, and the size and strength of the upper retaining rings 21a, 21b and the lower retaining rings 22a, 22b. In this embodiment, the amount of downward movement δ of the left upper retaining ring 21a and the right upper retaining ring 21b from the pass line PL is such that the following equation holds true in relation to the distance Δ of the displacement in the direction of travel of the upper retaining rings 21a, 21b and the lower retaining rings 22a, 22b.

[0036] 0.04 × Δ ≤ δ ≤ 0.07 × Δ If the downward movement δ is 0.04 × Δ or greater, the amount of pressure applied to the metal strip S is sufficient, increasing the contact area between the upper retaining rings 21a, 21b and the lower retaining rings 22a, 22b and the metal strip S, thereby more effectively preventing chipping of the blades due to impact caused by the flapping of the metal strip. On the other hand, if the downward movement δ is 0.07 × Δ or less, it is preferable because excessive load is not placed on the lower blades 12a, 12b that support the metal strip S when shearing both edges of the metal strip S in the width direction.

[0037] The left upper retaining ring 21a and the left lower retaining ring 22a are each attached to a left-side housing (not shown) that supports the left side trimmer 10a. The right upper retaining ring 21b and the right lower retaining ring 22b are each attached to a right-side housing (not shown) that supports the right side trimmer 10b.

[0038] As shown in Figure 3, the left upper retaining ring 21a and the left lower retaining ring 22a are retracted to the outside in the width direction of the metal strip S when the widthwise edges of the metal strip S are not being sheared. Similarly, as shown in Figure 3, the right upper retaining ring 21b and the right lower retaining ring 22b are also retracted to the outside in the width direction of the metal strip S when the widthwise edges of the metal strip S are not being sheared. When the widthwise edges of the metal strip S are being sheared, the left and right housings are moved inward in the width direction of the metal strip S, as indicated by arrow B, and the left upper retaining ring 21a and the left lower retaining ring 22a, and the right upper retaining ring 21b and the right lower retaining ring 22b are moved inward in the width direction of the metal strip S to hold the vicinity of both ends of the metal strip S in the width direction.

[0039] Furthermore, as shown in Figure 4, the upper retaining ring 21a on the left side has a cylindrical shape with a diameter d21 and a body length l21. Similarly, the upper retaining ring 21b on the right side also has a cylindrical shape with a diameter d21 and a body length l21.

[0040] As shown in Figure 5, the left lower retaining ring 22a comprises a cylindrical parallel portion 22aa having a diameter d22aa and a body length l22aa, and a shoulder portion 22ab with a body length l22ab that extends from one end face of the parallel portion 22aa so as to gradually taper in outer diameter. As shown in Figure 3, the shoulder portion 22ab has the function of guiding the vicinity of the left end in the width direction of the metal strip S to the pinch position when the left upper retaining ring 21a and the left lower retaining ring 22a are moved inward in the width direction of the metal strip S. Similarly, the right lower retaining ring 22b comprises a cylindrical parallel portion 22ba having a diameter d22aa and a body length l22a, and a shoulder portion 22bb with a body length l22ab that extends from one end face of the parallel portion 22ba so as to gradually taper in outer diameter. The shoulder portion 22bb also has the function of guiding the vicinity of the rightmost end in the width direction of the metal strip S to the pinch position when the right upper retaining ring 21b and the right lower retaining ring 22b are moved inward in the width direction of the metal strip S.

[0041] Next, a side trimming method for shearing both widthwise edges of the metal strip S using the side trimming equipment 1 configured in this way will be explained with reference to Figures 1 to 3. Before shearing both edges of the metal strip S in the width direction, as shown in Figure 3, the left side trimmer 10a and the right side trimmer 10b are retracted to the outside in the width direction of the metal strip S. Also, the left upper retaining ring 21a and the left lower retaining ring 22a, and the right upper retaining ring 21b and the right lower retaining ring 22b are retracted to the outside in the width direction of the metal strip S.

[0042] Then, when shearing both edges of the metal strip S in the width direction, the left housing to which the left side trimmer 10a is attached and the right housing to which the right side trimmer 10b is attached are moved inward in the width direction of the metal strip S, as indicated by arrow B. At the same time, the left upper retaining ring 21a and left lower retaining ring 22a attached to the left housing, and the right upper retaining ring 21b and right lower retaining ring 22b attached to the right housing are also moved inward in the width direction of the metal strip S, as indicated by arrow B.

[0043] As the left upper retaining ring 21a and left lower retaining ring 22a, and the right upper retaining ring 21b and right lower retaining ring 22b move inward in the width direction of the metal strip S indicated by arrow B, the shoulder portion 22ab of the left lower retaining ring 22a and the shoulder portion 22bb of the right lower retaining ring 22b guide the vicinity of both ends (left and right ends) in the width direction of the metal strip S to a pinch position. Then, on the upstream side of the pair of side trimmers 10a and 10b in the direction of travel of the metal strip S, the left and right upper retaining rings 21a and 21b and the left and right lower retaining rings 22a and 22b hold the metal strip S from above and below. This makes it possible to suppress flapping of the metal strip S when shearing both edges in the width direction of the metal strip S with the left and right side trimmers 10a and 10b.

[0044] Next, the upper blades 11a and 11b, which constitute the cutting edges of the pair of left and right side trimmers 10a and 10b, rotate and descend to shear both edges of the metal strip S in the width direction, as shown in Figures 1 and 2. During this time, the lower blades 12a and 12b rotate and support the metal strip S. This allows the metal strip S to be sheared along both edges in the width direction.

[0045] In this process, the upper blades 11a and 11b that constitute the cutting edge push the edges of the metal strip S downward, so the upper blades 11a and 11b are subjected to a normal force and a lateral force due to friction between the metal strip S and the upper blades 11a and 11b. As a result, the upper blades 11a and 11b that constitute the cutting edge are prone to being subjected to a large load and are likely to chip. In such cases, if the incidence of the metal strip S on the upper blades 11a and 11b that constitute the rotating blade is from above the pass line PL, the force on the upper blades 11a and 11b increases even further, which may result in further chipping.

[0046] In the side trimming equipment 1, the left upper pressing ring 21a is positioned downstream of the left lower pressing ring 22a in the direction of travel of the metal strip S, as shown in Figure 1, where the pair of side trimmers 10a and 10b are located. Similarly, the right upper pressing ring 21b is also positioned downstream of the right lower pressing ring 22b in the direction of travel of the metal strip S, where the pair of side trimmers 10a and 10b are located. Furthermore, the left upper pressing ring 21a and the right upper pressing ring 21b are positioned to push the metal strip S downward from the pass line PL where the lower blades 12a and 12b are located.

[0047] As a result, the upper pressing rings 21a, 21b and the metal strip S make surface contact, and the lower pressing rings 22a, 22b and the metal strip S make surface contact, pressing down on the metal strip S. This increases the contact area between the upper pressing rings 21a, 21b and the lower pressing rings 22a, 22b and the metal strip S compared to line contact, thereby greatly increasing the effect of suppressing the fluttering of the metal strip S. In addition, by pushing the metal strip S downward from the pass line PL with the upper pressing rings 21a, 21b, the incidence of the metal strip S on the upper blades 11a, 11b that constitute the rotating blade is from below the pass line PL, thus avoiding an increase in the force applied to the upper blades 11a, 11b. Therefore, it functions effectively to prevent chipping of the blades due to impact caused by the fluttering of the metal strip S, and can effectively prevent chipping of the blades due to impact caused by the fluttering of the metal strip S, regardless of the thickness of the metal strip.

[0048] (Second Embodiment) Next, a side trimming apparatus and a side trimming method according to a second embodiment of the present invention will be described with reference to Figures 6 to 8.

[0049] Figure 6 shows a schematic configuration of a side trimming device according to the second embodiment of the present invention, as viewed from the left side of a metal strip. The side trimming equipment 1 according to the second embodiment shown in Figure 6 has the same basic configuration as the side trimming equipment 1 according to the first embodiment shown in Figure 1.

[0050] However, in the side trimming equipment 1 according to the first embodiment shown in Figure 1, the lower blades 12a and 12b of the left side trimmer 10a and the right side trimmer 10b, respectively, are positioned on the inside in the width direction of the metal strip S, as shown in Figure 2. Also, the upper blades 11a and 11b of the left side trimmer 10a and the right side trimmer 10b, respectively, are positioned on the outside in the width direction of the metal strip S relative to the lower blades 12a and 12b. When shearing both edges of the metal strip S in the width direction, the lower blades 12a and 12b support the metal strip S, and the upper blades 11a and 11b form the cutting edges and are responsible for cracking to shear and break the metal strip S.

[0051] In contrast, in the side trimming equipment 1 according to the second embodiment, unlike the side trimming equipment 1 according to the first embodiment shown in Figure 1, the upper blades 11a and 11b of the left side trimmer 10a and the right side trimmer 10b, respectively, are positioned on the inside in the width direction of the metal strip S, as shown in Figure 7. Also, the lower blades 12a and 12b of the left side trimmer 10a and the right side trimmer 10b, respectively, are positioned on the outside in the width direction of the metal strip S relative to the upper blades 11a and 11b. When shearing both edges of the metal strip S in the width direction, the upper blades 11a and 11b support the metal strip S, and the lower blades 12a and 12b form the cutting edges and are responsible for shearing and cracking the metal strip S.

[0052] In the side trimming equipment 1 according to the first embodiment shown in Figure 1, since the upper blades 11a and 11b constitute the cutting blades, the left upper retaining ring 21a is positioned downstream of the left lower retaining ring 22a in the direction of travel of the metal strip S, where the pair of side trimmers 10a and 10b are located, as shown in Figure 1. Similarly, the right upper retaining ring 21b is also positioned downstream of the right lower retaining ring 22b in the direction of travel of the metal strip S, where the pair of side trimmers 10a and 10b are located.

[0053] Furthermore, in the side trimming equipment 1 according to the first embodiment shown in the first image, the left upper pressing ring 21a and the right upper pressing ring 21b are positioned to push the metal strip S downward from the pass line PL where the lower blades 12a and 12b are located.

[0054] In contrast, in the side trimming equipment 1 according to the first embodiment shown in Figure 2, since the lower blades 12a and 12b constitute the cutting blades, the left lower retaining ring 22a is positioned downstream of the left upper retaining ring 21a in the direction of travel of the metal strip S, where the pair of side trimmers 10a and 10b are located, as shown in Figure 6. Similarly, the right lower retaining ring 22b is also positioned downstream of the right upper retaining ring 21b in the direction of travel of the metal strip S, where the pair of side trimmers 10a and 10b are located.

[0055] Furthermore, in the side trimming equipment 1 according to the first embodiment shown in the second example, unlike the side trimming equipment 1 according to the first embodiment shown in the first example, the left lower pressing ring 22a and the right lower pressing ring 22b are positioned to push the metal strip S upward from the pass line PL where the upper blades 11a and 11b are located. In the side trimming equipment 1 according to the first embodiment shown in Figure 2, the displacement distance in the direction of travel between the left lower retaining ring 22a and the left upper retaining ring 21a, and the displacement distance in the direction of travel between the right lower retaining ring 22b and the right upper retaining ring 21b, are distances such that the distance between their centerlines is Δ. These distances Δ are appropriately determined according to the diameters of the upper retaining rings 21a, 21b and the lower retaining rings 22a, 22b, and the thickness of the metal strip S.

[0056] Furthermore, the amount by which the left lower retaining ring 22a and the right lower retaining ring 22b push the metal strip S upward from the pass line PL, that is, the amount of rise δ of the left lower retaining ring 22a and the right lower retaining ring 22b from the pass line PL, is appropriately determined according to the strength, thickness, width, amount of shape change in the direction of travel at both edges in the width direction of the metal strip S, and the size and strength of the lower retaining rings 22a, 22b and the upper retaining rings 21a, 21b. In this embodiment, the amount of rise δ of the left lower retaining ring 22a and the right lower retaining ring 22b from the pass line PL is such that the following equation holds true in relation to the distance Δ of the displacement in the direction of travel of the upper retaining rings 21a, 21b and the lower retaining rings 22a, 22b.

[0057] 0.04 × Δ ≤ δ ≤ 0.07 × Δ If the upward movement δ is 0.04 × Δ or greater, the amount of pressure applied to the metal strip S is sufficient, increasing the contact area between the upper pressing rings 21a, 21b and the lower pressing rings 22a, 22b and the metal strip S, thereby more effectively preventing chipping of the blades due to impact caused by the flapping of the metal strip. On the other hand, if the upward movement δ is 0.07 × Δ or less, it is preferable that excessive load is not placed on the upper blades 11a, 11b that support the metal strip S when shearing both edges of the metal strip S in the width direction.

[0058] Next, a side trimming method for shearing both edges in the width direction of the metal strip S using the side trimming equipment 1 according to the second embodiment will be described with reference to Figures 6 to 8. Before shearing both edges of the metal strip S in the width direction, as shown in Figure 8, the left side trimmer 10a and the right side trimmer 10b are retracted to the outside in the width direction of the metal strip S. Also, the left upper retaining ring 21a and the left lower retaining ring 22a, and the right upper retaining ring 21b and the right lower retaining ring 22b are retracted to the outside in the width direction of the metal strip S.

[0059] Then, when shearing both edges of the metal strip S in the width direction, the left housing (not shown) to which the left side trimmer 10a is attached and the right housing (not shown) to which the right side trimmer 10b is attached are moved in the width direction of the metal strip S, as indicated by arrow B. At the same time, the left upper retaining ring 21a and left lower retaining ring 22a attached to the left housing, and the right upper retaining ring 21b and right lower retaining ring 22b attached to the right housing are also moved in the width direction of the metal strip S, as indicated by arrow B.

[0060] As the left upper retaining ring 21a and left lower retaining ring 22a, and the right upper retaining ring 21b and right lower retaining ring 22b move inward in the width direction of the metal strip S indicated by arrow B, the shoulder portion 22ab of the left lower retaining ring 22a and the shoulder portion 22bb of the right lower retaining ring 22b guide the vicinity of both ends (left and right ends) in the width direction of the metal strip S to a pinch position. Then, on the upstream side of the pair of side trimmers 10a and 10b in the direction of travel of the metal strip S, the left and right upper retaining rings 21a and 21b and the left and right lower retaining rings 22a and 22b hold the metal strip S from above and below. This makes it possible to suppress flapping of the metal strip S when shearing both edges in the width direction of the metal strip S with the left and right side trimmers 10a and 10b.

[0061] Next, the lower blades 12a and 12b, which constitute the cutting edges of the pair of left and right side trimmers 10a and 10b, rotate and rise to shear both edges of the metal strip S in the width direction, as shown in Figures 6 and 7. During this time, the upper blades 11a and 11b support the metal strip S while rotating. This allows the metal strip S to be sheared along both edges in the width direction.

[0062] In this process, the lower blades 12a and 12b that constitute the cutting edge push the edges of the metal strip S upward, so the lower blades 12a and 12b are subjected to a normal force and a lateral force due to friction between the metal strip S and the lower blades 12a and 12b. As a result, the lower blades 12a and 12b that constitute the cutting edge are prone to being subjected to a large load, which can easily cause chipping. In such cases, if the incidence of the metal strip S on the lower blades 12a and 12b that constitute the rotating blade is from above the pass line PL, the force on the upper blades 11a and 11b increases even further, which may result in further chipping.

[0063] In the side trimming equipment 1, the left lower retaining ring 22a is positioned downstream of the left upper retaining ring 21a in the direction of travel of the metal strip S, as shown in Figure 6, where the pair of side trimmers 10a and 10b are located. Similarly, the right lower retaining ring 22b is also positioned downstream of the right upper retaining ring 21b in the direction of travel of the metal strip S, where the pair of side trimmers 10a and 10b are located. Furthermore, the left lower retaining ring 22a and the right lower retaining ring 22b are positioned to push the metal strip S upward from the pass line PL where the upper blades 11a and 11b are located.

[0064] As a result, the upper pressing rings 21a, 21b and the metal strip S make surface contact, and the lower pressing rings 22a, 22b and the metal strip S make surface contact, pressing down on the metal strip S. This increases the contact area between the upper pressing rings 21a, 21b and the lower pressing rings 22a, 22b and the metal strip S compared to line contact, thereby greatly increasing the effect of suppressing the fluttering of the metal strip S. In addition, by pushing the metal strip S upward from the pass line PL with the lower pressing rings 22a, 22b, the incidence of the metal strip S on the lower blades 12a, 12b that constitute the rotating blade is from above the pass line PL, thus avoiding an increase in the force applied to the lower blades 12a, 12b. Therefore, it functions effectively to prevent chipping of the blades due to impact caused by the fluttering of the metal strip S, and can effectively prevent chipping of the blades due to impact caused by the fluttering of the metal strip S, regardless of the thickness of the plate.

[0065] Although embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications and improvements can be made. For example, in the side trimming equipment 1 according to the first embodiment, there may be robust holding devices such as high-pressure masher rolls or holding rings that hold the center of the metal strip S upstream of the upper holding rings 21a, 21b and lower holding rings 22a, 22b. In such cases, the upper holding rings 21a, 21b may not be pushed down, and only the lower holding rings 22a, 22b may be raised from the pass line PL. Alternatively, in the side trimming equipment 1 according to the first embodiment, the upper holding rings 21a, 21b may be lowered from the pass line PL, while the lower holding rings 22a, 22b may be raised from the pass line PL.

[0066] Furthermore, in the side trimming equipment 1 according to the second embodiment, there may be robust holding devices such as high-pressure masher rolls or holding rings that hold the center of the metal strip S upstream of the upper holding rings 21a, 21b and lower holding rings 22a, 22b. In such cases, the lower holding rings 22a, 22b may not be pushed down, and only the upper holding rings 21a, 21b may be lowered from the pass line PL. Alternatively, in the side trimming equipment 1 according to the second embodiment, the upper holding rings 21a, 21b may be lowered from the pass line PL, while the lower holding rings 22a, 22b may be raised from the pass line PL.

[0067] In other words, in the side trimming equipment 1 according to the first and second embodiments, the upper pressing rings 21a, 21b and the lower pressing rings 22a, 22b are positioned offset from each other in the direction of travel indicated by arrow A of the metal strip S. Furthermore, it is sufficient that one or both of the upper pressing rings 21a, 21b and the lower pressing rings 22a, 22b are positioned to push the metal strip S in the direction normal to the pass line PL.

[0068] In the side trimming methods according to the first and second embodiments, the upper blades 11a, 11b and lower blades 12a, 12b of one side trimmer 10a and the other side trimmer 10b, respectively, shear both edges in the width direction of the metal strip S as it moves along the pass line PL. At this time, the metal strip S is held between the upstream side of the pair of side trimmers 10a, 10b in the direction of travel of the metal strip S, and either or both of the upper retaining rings 21a, 21b and lower retaining rings 22a, 22b, which are positioned offset in the direction of travel of the metal strip S, push the metal strip S in the direction normal to the pass line PL.

[0069] This effectively prevents chipping of the blade due to impact caused by fluttering of the metal strip S, regardless of the plate thickness.

[0070] Furthermore, the side trimming equipment 1 shown in Figures 1 and 6 can be applied to metal strip manufacturing lines other than the annealing line after cold rolling. [Examples]

[0071] To verify the effects of the present invention, shearing was performed on both widthwise edges of a steel strip with a tensile strength of 780 MPa or more using the side trimming equipment 1 shown in Figure 1 (example of the present invention). The diameter d21 of the left and right upper retaining rings 21a and 21b used was 150 mm, and the body length l21 was 115 mm. The diameter d22aa of the parallel sections 22aa and 22ba of the left and right lower retaining rings 22a and 22b used was 150 mm, and the body length l22aa was 90 mm. The body length l22ab of the shoulder sections 22ab and 22bb of the left and right lower retaining rings 22a and 22b was 100 mm. The material of the left and right upper retaining rings 21a and 21b is MC nylon. The material of the left and right lower retaining rings 22a and 22b is MC nylon with a urethane rubber lining around it.

[0072] Then, the upper retaining rings 21a and 21b on the left and right sides were positioned offset from the lower retaining rings 22a and 22b on the left and right sides to the downstream side in the direction of travel of the metal strip S, and the offset distance Δ in the direction of travel was set to 80 mm.

[0073] Furthermore, the upper blades 11a and 11b on the left and right sides used are circular blades with a diameter of 430 mm and a thickness of 30 mm, and their material is SKD11. Similarly, the lower blades 12a and 12b on the left and right sides used are also circular blades with a diameter of 430 mm and a thickness of 30 mm, and their material is SKD11.

[0074] Then, the metal strip S was pushed in from the pass line PL with the downward amount δ of the left and right upper retaining rings 21a and 21b from the pass line PL set to 4 mm. As a result, the chipping of the upper blades 11a and 11b on the left and right sides occurred 0-1 times per 6000 kt of steel strip (0-1 times / 6000 kt). The extent of the chipping was approximately 1-2 mm in the trim surface (circumferential surface of upper blades 11a and 11b) and the side surface (inner surface of upper blades 11a and 11b). This extent of chipping is within the range that can be removed by grinding.

[0075] In contrast, a side trimming apparatus 1 shown in Figure 1 was used in which the left and right upper pressing rings 21a and 21b were positioned without being pushed downward from the pass line PL, and shearing was performed on both edges in the width direction of a steel strip with a tensile strength of 780 MPa or more (comparative example).

[0076] As a result, chipping of the upper blades 11a and 11b on the left and right sides occurred at a rate of 1 chip per 1000 kt of steel strip (1 chip / 1000 kt), indicating a high frequency. Furthermore, the extent of the chipping was extremely large, approximately 10 mm in the direction of the trim surface (circumferential surface of the upper blades 11a and 11b) and approximately 20 mm in the direction of the side surface (inner surface of the upper blades 11a and 11b).

[0077] Therefore, it was found that in the present invention example, the frequency and degree of chipping of the upper blades 11a and 11b on the left and right sides were reduced compared to the comparative example. [Explanation of symbols]

[0078] 1. Side trimming equipment 10a Left side (one side) side trimmer 10b Right side (other side) side trimmer 11a Left upper blade 11b Right upper blade 12a Left lower blade 12b Right lower blade 21a Upper retaining ring on the left side 21b Right upper retaining ring 22a Left lower retaining ring 22aa parallel part 22ab Shoulder 22b Right-side lower retaining ring 22ba parallel part 22bb shoulder PL Passline S Metal strip

Claims

1. A side trimming apparatus comprising a pair of side trimmers installed on both sides in the width direction of a metal strip moving along a pass line, wherein one of the side trimmers has an upper blade and a lower blade for shearing one edge of the metal strip in the width direction, and the other side trimmer has an upper blade and a lower blade for shearing the other edge of the metal strip in the width direction, The metal strip is further provided with an upper and lower retaining ring that holds the metal strip between the upper and lower sections on the upstream side of the pair of side trimmers in the direction of travel of the metal strip, The upper and lower retaining rings are positioned offset from each other in the direction of travel of the metal strip, and either one or both of the upper and lower retaining rings are positioned to push the metal strip in the direction normal to the pass line. The side trimming equipment is characterized in that each of the upper and lower pressing rings is installed in a pair on both sides of the metal strip in the width direction.

2. The lower blades of one side trimmer and the other side trimmer are positioned on the inside in the width direction of the metal strip, and the upper blades of the one side trimmer and the other side trimmer are positioned on the outside in the width direction of the metal strip relative to the lower blade, thereby forming a cutting edge. The side trimming apparatus according to claim 1, characterized in that the upper retaining ring is positioned to push the metal strip downward from the pass line on which the lower blade is located.

3. The side trimming equipment according to claim 2, characterized in that the upper retaining ring is positioned downstream of the lower retaining ring in the direction of travel of the metal strip, on the side where the pair of side trimmers are located.

4. The upper blades of one side trimmer and the other side trimmer are positioned on the inside in the width direction of the metal strip, and the lower blades of the one side trimmer and the other side trimmer are positioned on the outside in the width direction of the metal strip relative to the upper blade, thereby forming a cutting edge. The side trimming apparatus according to claim 1, characterized in that the lower retaining ring is positioned to push the metal strip upward from the pass line on which the upper blade is located.

5. The side trimming equipment according to claim 4, characterized in that the lower retaining ring is positioned downstream of the upper retaining ring in the direction of travel of the metal strip, where the pair of side trimmers are located.

6. The side trimming apparatus according to claim 1, characterized in that when the amount of indentation by either one or both of the upper and lower pressing rings pushing the metal strip in the direction normal to the pass line is δ, and the distance of displacement of the upper and lower pressing rings in the direction of travel is Δ, the following equation holds true. 0.04 × Δ ≤ δ ≤ 0.07 × Δ

7. A side trimming method comprising a side trimming apparatus that cuts both edges of a metal strip in the width direction, the apparatus comprising a pair of side trimmers installed on both sides in the width direction of a metal strip moving along a pass line, wherein one of the pair of side trimmers has an upper blade and a lower blade for shearing one edge of the metal strip in the width direction, and the other of the pair of side trimmers has an upper blade and a lower blade for shearing the other edge of the metal strip in the width direction, When the upper and lower blades of one side trimmer and the other side trimmer, respectively, shear both edges in the width direction of a metal strip moving along a pass line, the metal strip is held between the pair of side trimmers from above and below on the upstream side in the direction of the metal strip's movement, and one or both of the upper and lower retaining rings, which are positioned offset from each other in the direction of the metal strip's movement, push the metal strip in the direction normal to the pass line. A side trimming method characterized in that each of the upper and lower pressing rings is installed in a pair on both sides of the metal strip in the width direction.

8. The lower blades of one side trimmer and the other side trimmer are positioned on the inside in the width direction of the metal strip, and the upper blades of the one side trimmer and the other side trimmer are positioned on the outside in the width direction of the metal strip relative to the lower blade, thereby forming a cutting edge. The side trimming method according to claim 7, characterized in that the upper retaining ring pushes the metal strip downward from the pass line on which the lower blade is located.

9. The side trimming method according to claim 8, characterized in that the upper retaining ring is positioned downstream of the lower retaining ring in the direction of travel of the metal strip, where the pair of side trimmers are located.

10. The upper blades of one side trimmer and the other side trimmer are positioned on the inside in the width direction of the metal strip, and the lower blades of the one side trimmer and the other side trimmer are positioned on the outside in the width direction of the metal strip relative to the upper blade, thereby forming a cutting edge. The side trimming method according to claim 7, characterized in that the lower retaining ring pushes the metal strip upward from the pass line on which the upper blade is located.

11. The side trimming method according to claim 10, characterized in that the lower retaining ring is positioned downstream of the upper retaining ring in the direction of travel of the metal strip, where the pair of side trimmers are located.

12. The side trimming method according to claim 7, characterized in that when the amount of indentation by either one or both of the upper and lower pressing rings pushing the metal strip in the direction normal to the pass line is δ, and the distance of displacement of the upper and lower pressing rings in the direction of travel is Δ, the following equation holds true. 0.04 × Δ ≤ δ ≤ 0.07 × Δ

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