JP7838591B2 - Side trimming equipment and side trimming method - Google Patents

Description

This invention relates to a side trimming apparatus and a side trimming method for shearing both edges in the width direction of a metal strip.

In manufacturing lines that produce metal strips, such as annealing lines after cold rolling, it is common practice to trim the widthwise edges of the metal strip using side trimming equipment (shearing) to remove irregularities in the shape of the widthwise ends of the manufactured metal strip and to standardize the width of the metal strip to the product dimensions. This side trimming equipment consists of a pair of side trimmers located on both sides of the widthwise direction of the metal strip being transported along the pass line. Each side trimmer has an upper and lower blade for shearing the widthwise edge of the metal strip as it is transported along the pass line.

The upper or lower blades of each side trimmer can become chipped due to wear or impact, which can reduce their shearing capacity and lead to quality defects such as rough edges on the sheared portion.
Conventionally, methods for preventing chipping of the upper and lower blades in side trimmers are known, such as those shown in Patent Documents 1 to 3.

The cutting tool described 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 and a cutting edge constituent surface that constitutes the cutting edge ridge. The cutting edge constituent surface has a surface portion where the ceramic phase protrudes from the composite material layer containing the ceramic phase and metal phase, resulting in an intermittent presence of the ceramic phase and a lack of the metal phase. Furthermore, the surface roughness is configured to satisfy an arithmetic mean roughness Ra ≤ 0.1 μm and a skewness Rsk ≤ -0.01.

According to the cutting tool shown in Patent Document 1, it is possible to create a cutting tool that has both good adhesion resistance and smoothness.
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.

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 during steel plate shearing from adhering to the trimmer blade and causing chipping.

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. This plate retaining ring has a cylindrical portion adjacent to the disc-shaped blade, with a tapered portion at its tip.

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 by 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.

International Publication No. 2019/65677 Japanese Patent Publication No. 2005-153116 Japanese Patent Application Publication No. 11-277325

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.

Furthermore, the method of applying cutting oil to the trimmer blade shown in Patent Document 2 is effective in preventing minute chipping of the blade due to 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.

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.

However, in the metal strip side trimmer plate clamping ring shown in Patent Document 3, the upper clamping ring, located inside the upper disc-shaped blade, and the lower clamping ring, located inside the lower disc-shaped blade, are arranged in a straight line in the direction of metal strip movement. Therefore, the upper clamping ring and the metal strip make linear contact, and the lower clamping ring and the metal strip make linear contact to hold the metal strip in place. In this case, the contact area between the upper and lower clamping rings and the metal strip is small, resulting in a reduced effect in suppressing metal strip flapping and ineffectively preventing blade chipping caused by impact due to metal strip flapping. This is particularly true for thin metal strips (e.g., about 0.8 mm thick).

This 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 blade chipping caused by impact due to flapping of the metal strip, regardless of the thickness of the sheet metal.

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 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, and further comprises an upper and lower retaining ring that holds 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, wherein 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.

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 and 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 and lower blade for shearing the other edge of the metal strip in the width direction, and the side trimming method is used to shear both edges of the metal strip in the width direction by a side trimming apparatus, wherein, when shearing both edges of the metal strip in the width direction of the metal strip traveling along the pass line with the upper and lower blades of the one side trimmer and the other side trimmer, 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 retaining 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.

According to the side trimming equipment and method of the present invention, regardless of the thickness of the metal strip, it is possible to effectively prevent chipping of the blade due to impact caused by fluttering of the metal strip.

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. This is a cross-sectional view along line 2-2 in Figure 1. 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 1 shows the upper retaining ring in the side trimming equipment, where (a) is a view of the left upper retaining ring from the left side of the metal strip, and (b) is a view of the left upper retaining ring from the front of the metal strip. Figure 1 shows the lower retaining ring in the side trimming equipment, where (a) is a view of the left lower retaining ring from the left side of the metal strip, and (b) is a view of the left lower retaining ring from the front of the metal strip. This diagram shows the schematic configuration of a side trimming device according to a second embodiment of the present invention, as viewed from the left side of a metal strip. This is a cross-sectional view along line 7-7 in Figure 6. Figure 6 shows the side trimming equipment as viewed from the front of the metal strip. However, in Figure 8, 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.

Embodiments of the present invention will be described below with reference to the drawings. The embodiments shown below are illustrative examples of devices and methods for realizing the technical concept of the present invention, and the technical concept of the present invention is not limited to the following embodiments in terms of the material, shape, structure, arrangement, etc. of the components.
Furthermore, drawings are schematic representations. Therefore, it should be noted that the relationship and ratios between thickness and planar dimensions may differ from those in reality, and there may be differences in dimensional relationships and ratios between drawings themselves.

(First Embodiment)
Figure 1 shows a 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.
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.

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 moving 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 moving 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 moving along the pass line PL.

Here, the upper blade 11a and lower blade 12a of the left side trimmer 10a are circular blades, detachably mounted on 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, detachably mounted on 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, thus forming a rotating blade.

As shown in Figure 2, the lower blades 12a and 12b of the left and right side trimmers 10a and 10b, respectively, are positioned on the inside in the width direction of the metal strip S. The upper blades 11a and 11b of the left and right side trimmers 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 and right side trimmers 10a and 10b, both 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.

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 shearing the widthwise edges of the metal strip S. When shearing the widthwise edges of the metal strip S, the left and right housings are moved inward in the widthwise 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 widthwise direction of the metal strip S to shear the widthwise edges of the metal strip S.

Furthermore, the side trimming equipment 1 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.

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.

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 clamped 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.

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.

Thus, the system 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 allows for suppression of 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.

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, which form the cutting edges, push the edges of the metal strip S downwards, 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. Therefore, the upper blades 11a and 11b, which form the cutting edges, are prone to being subjected to large loads and are susceptible to chipping. In such cases, if the incidence of the metal strip S on the upper blades 11a and 11b, which form the rotating blades, is from above the pass line PL, the force on the upper blades 11a and 11b increases further, which may induce further chipping.

Therefore, in the side trimming equipment 1 of this embodiment, firstly, the upper retaining rings 21a, 21b and 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 between the left upper retaining ring 21a and the left lower retaining ring 22a in the direction of travel is the distance Δ between their centerlines.

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.

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.

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, this effectively prevents 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.

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, and amount of shape change in the direction of travel at both edges in the width direction of the metal strip S, as well as 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 set such that the following equation holds true in relation to the displacement distance Δ of the upper retaining rings 21a, 21b and the lower retaining rings 22a, 22b in the direction of travel.

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 pressing rings 21a, 21b and the lower pressing rings 22a, 22b and the metal strip S, and 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.

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

Furthermore, 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 neither edge in the width direction of the metal strip S is 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 neither edge in the width direction of the metal strip S is being sheared. Then, when both edges in the width direction 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 in the width direction of the metal strip S.

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.

Furthermore, 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 moving the right upper retaining ring 21b and the right lower retaining ring 22b in the width direction of the metal strip S.

Next, a side trimming method for shearing both edges in the width direction 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.

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, also move inward in the width direction of the metal strip S, as indicated by arrow B.

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 shoulders 22ab of the left lower retaining ring 22a and 22bb of the right lower retaining ring 22b guide the metal strip S to a pinch position near both ends (left and right ends) in the width direction. Then, upstream of the pair of side trimmers 10a and 10b in the direction of metal strip S's movement, 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 suppresses flapping of the metal strip S when shearing both width edges of the metal strip S with the left and right side trimmers 10a and 10b.

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. At 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.

In this process, the upper blades 11a and 11b, which constitute the cutting edge, push the edges of the metal strip S downwards. Therefore, 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 are easily subjected to a large load, making them prone to chipping. In such cases, if the incidence of the metal strip S on the upper blades 11a and 11b of the rotating blade is above the pass line PL, the force on the upper blades 11a and 11b increases further, potentially inducing further chipping.

In the side trimming equipment 1, the left upper pressing ring 21a is positioned downstream of the left lower pressing ring 22a, where the pair of side trimmers 10a and 10b are located, in the direction of travel of the metal strip S, as shown in Figure 1. Similarly, the right upper pressing ring 21b is also positioned downstream of the right lower pressing ring 22b, where the pair of side trimmers 10a and 10b are located, in the direction of travel of the metal strip S. 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.

This results in surface contact between the upper pressing rings 21a and 21b and the metal strip S, and surface contact between the lower pressing rings 22a and 22b and the metal strip S, thereby pressing down on the metal strip S. This increases the contact area between the upper and lower pressing rings 21a and 21b and the metal strip S compared to line contact, significantly reducing the effectiveness of suppressing metal strip flutter. Furthermore, by pushing the metal strip S downward from the pass line PL using the upper pressing rings 21a and 21b, the incidence of the metal strip S on the upper blades 11a and 11b, which constitute the rotating blade, is below the pass line PL, thus avoiding an increase in the force applied to the upper blades 11a and 11b. Therefore, this effectively prevents chipping of the blades due to impact caused by metal strip flutter, regardless of the thickness of the metal strip S.

(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.

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.

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. Furthermore, 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, while the upper blades 11a and 11b form the cutting edges and are responsible for shearing and cracking the metal strip S.

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. Furthermore, 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, while the lower blades 12a and 12b form the cutting edges and are responsible for shearing and cracking the metal strip S.

Furthermore, 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 edges, 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.

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.

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.

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.

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, and amount of shape change in the direction of travel at both edges in the width direction of the metal strip S, as well as 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 set such that the following equation holds true in relation to the positional displacement Δ of the upper retaining rings 21a, 21b and the lower retaining rings 22a, 22b in the direction of travel.

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 because 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.

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.

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 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, also move inward in the width direction of the metal strip S, as indicated by arrow B.

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 shoulders 22ab of the left lower retaining ring 22a and 22bb of the right lower retaining ring 22b guide the metal strip S to a pinch position near both ends (left and right ends) in the width direction. Then, upstream of the pair of side trimmers 10a and 10b in the direction of metal strip S's movement, 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 suppresses flapping of the metal strip S when shearing both width edges of the metal strip S with the left and right side trimmers 10a and 10b.

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 rotate and support the metal strip S.
This allows the metal strip S to be sheared along both edges in the width direction.

In this process, the lower blades 12a and 12b, which constitute the cutting edge, push the edges of the metal strip S upward. Therefore, 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 are easily subjected to a large load, making them prone to chipping. In such cases, if the incidence of the metal strip S on the lower blades 12a and 12b of the rotating blade is above the pass line PL, the force on the upper blades 11a and 11b increases further, potentially inducing further chipping.

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

This results in surface contact between the upper and lower pressing rings 21a and 21b and the metal strip S, and surface contact between the lower and lower pressing rings 22a and 22b, pressing down on the metal strip S. This increases the contact area between the upper and lower pressing rings 21a and 21b and the metal strip S compared to line contact, significantly reducing the fluttering effect of the metal strip S. Furthermore, by pushing the metal strip S upward from the pass line PL using the lower pressing rings 22a and 22b, the incidence of the metal strip S on the lower blades 12a and 12b of the rotating blade is above the pass line PL, thus avoiding an increase in the force applied to the lower blades 12a and 12b. Therefore, this effectively prevents chipping of the blades due to impact caused by metal strip fluttering, regardless of the thickness of the metal strip S.

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.

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.

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.

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 by being sandwiched from above and below by the upstream side of the pair of side trimmers 10a, 10b in the direction of the metal strip S's movement, and either or both of the upper retaining rings 21a, 21b and lower retaining rings 22a, 22b, which are positioned offset from each other in the direction of the metal strip S's movement, push the metal strip S in the direction normal to the pass line PL.

This effectively prevents chipping of the blade caused by impact resulting from the fluttering of the metal strip S, regardless of the plate thickness.

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.

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.

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, respectively, 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.

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.

Then, the metal strip S was pushed in from the pass line PL with the lowering 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 the upper blades 11a and 11b) and the side surface (inner surface of the upper blades 11a and 11b). This extent of chipping is within the range that can be removed by grinding.

In contrast, a side trimming apparatus 1, as shown in Figure 1, was used to perform shearing of both widthwise edges of a steel strip with a tensile strength of 780 MPa or more. The upper retaining rings 21a and 21b on the left and right sides were positioned without being pushed downward from the pass line PL. (Comparative Example)

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 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).

Therefore, in the present invention example, it was found that both 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.

1 Side trimming equipment 10a Left side trimmer (one side) 10b Right side trimmer (the other side) 11a Left upper blade 11b Right upper blade 12a Left lower blade 12b Right lower blade 21a Left upper retaining ring 21b Right upper retaining ring 22a Left lower retaining ring 22aa Parallel section 22ab Shoulder section 22b Right lower retaining ring 22ba Parallel section 22bb Shoulder section PL Pass line S Metal strip

Claims (12)

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. 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. The side trimming apparatus 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, where the pair of side trimmers are located. 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. The side trimming apparatus 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. 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 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. 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. 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. 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. 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. 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