JPH0316202B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention aims to prevent so-called edge cracking of trim material that is side-trimmed for the purpose of improving the width accuracy of a band-shaped metal plate (hereinafter simply referred to as steel band). This relates to a longitudinal edge processing method.

[Prior Art] As is well known, for example, when a hot-rolled steel strip is supplied to the next cold rolling process, it is well known to trim the longitudinal edges of the steel strip in advance. There is.

As shown in FIG. 8, an upper circular rotary blade 1 and a lower circular rotary blade 2 are used as a device (trimmer) for continuously trimming the edges in the longitudinal direction on both sides of the steel strip with a trim width equal to or greater than the plate thickness. It is often used that the strip is set perpendicular to the width direction of the strip. However, when the shearing ability of these types of trimmers decreases due to deterioration of the circular rotary blade, the cut surface tends to sag or burr, or incomplete cutting tends to occur.

Furthermore, when carrying out minute trimming, there is a limitation that the trimming margin cannot be made very small using the above-mentioned trimmer, and the problem of securing shearing accuracy tends to become more and more prominent.

In recent years, from the viewpoint of yield, partial trimming has been carried out intermittently, which targets only the parts where the strip width widens in the longitudinal direction of the strip, and micro trimming, which involves trimming with a trim width smaller than the strip thickness, has been carried out. However, the reality is that the above-mentioned trimmer has to have good cutting performance, so it is forced to have a generous amount of trimming allowance.

In order to solve these problems, a trimmer (hereinafter referred to as an angled trimmer) in which one of the circular rotary blades 1 is inclined at a constant angle θ ₁ with respect to the width direction of the steel strip, as shown in Fig. 1, was proposed, and compared to the above-mentioned trimmer, Because of its good cutting performance, the trim width can be kept very small.In other words, it has a great effect on improving micro trim performance, and allows shearing to be performed with almost no sagging or burrs while making it possible to trim extremely thin widths. It became.

That is, this bevel trimmer was first applied for by some of the inventors of the present invention (Japanese Patent Application No. 59-67086).
As shown in the figure, one circular rotary blade (the upper circular rotary blade 1 in the figure) is arranged at an oblique angle θ ₁ with respect to the end face of the steel strip.

As can be seen from the figure, this upper circular rotary blade 1 is characterized in that it bites diagonally into the steel band during cutting, and at that time, tension is applied to the steel band in the width direction by the circular rotary blade.

In other words, by trimming with the inclined upper circular rotary blade 1 while applying tension to the cutting part,
It has the feature of ensuring excellent ultra-fine cutting performance and removing sagging and burrs that normally occur during cutting.

Therefore, this inclination angle θ ₁ is determined according to the plate thickness, material, and trim allowance within the range (usually 1 to 45 degrees) where the circular rotary cutter bites into the band plate and tension is applied. (5 to 15 degrees is appropriate for ordinary steel plates) [Problems to be solved by the invention] However, according to the knowledge of the present inventors, the strip steel trimmed by this bevel trimmer is cold rolled in the next process. Then, the cracks at the edges of the strip in the longitudinal direction are
A new problem has arisen, which is more likely to occur than with trimming materials made with a regular normal-angle trimmer. As a result of further research on this point, the following was discovered.

Figure 2 shows a cut surface of the end of a steel strip trimmed by an angle trimmer, and the cut surface has a certain angle, and the cut surface has a relatively smooth upper sheared portion A and an uneven surface. The lower fracture part B has two different surfaces, and when a steel strip with such a cut surface is rolled, no rolling is applied to this cut surface, and the other parts extend in the longitudinal direction. The cut surface is pulled against this and excessive tension is applied. As a result, the minute cracks inherent in the lower fracture portion B cause the aforementioned cracking of the edge portion in the longitudinal direction of the steel strip, the so-called ear cracking phenomenon.

As a conventional method for forming the end face of a steel strip, for example,
No. 58-84604, Japanese Patent Application Laid-Open No. 58-9703, etc. are known, but since the trimmers used in these methods have ordinary rotating round blades, the trimming distance should be 10 mm or less to avoid sag or burrs. It is said that the cross-sectional properties after trimming are extremely poor. Therefore, these methods use a rolling device or a cutting tool to shape the end face after trimming, but they have the disadvantage that they cannot handle minute trims.
Furthermore, it is not possible to completely prevent the occurrence of sagging and burrs due to the reduction in the shearing ability of the cutter, and in particular, in the former method where the end face is shaped by applying pressure reduction, there may even be the inconvenience that these sag or burrs are folded in. be.

In the present invention, an oblique trim is performed in order to be able to cope with minute trims, and a simple cut surface consisting of a sheared part A on the upper side and a broken part B on the lower side without sagging or burrs is created, and at least By improving the broken part B, the end cracks peculiar to beveled trims are eliminated,
A stable and reliable micro-trim has been established, and the combination of these will dramatically improve the yield in strip steel trimming work.

[Means for Solving the Problems] Therefore, the present invention achieves the following by ensuring the above-mentioned shearing capacity and plate width accuracy during partial trim and minute trim, and by preventing cracks at the plate ends. The aim is to obtain a stable trim material and increase productivity.The feature is that the upper circular rotary blade of a pair of circular rotary blades is attached to the longitudinal edge of the strip metal plate. Trimming is performed by tilting (θ) so as to apply tension in the width direction of the band-shaped metal plate to the extent that it can bite into the end face of the band-shaped metal plate, and then, after trimming, the upper sheared part A and the lower broken part B that constitute the cut surface are trimmed. Of these, by either pressing the lower broken part B or removing it by cutting or grinding,
The purpose is to process the shearing part A so that it does not protrude further to the front than at least the lower position of the shearing part A.

[Example] The present invention will be specifically described below based on an example shown in the drawings.

First Embodiment: FIG. 3 shows a shape straightening device for the longitudinal edge of a steel strip after bevel trimming. Part B is pressed by the forming roll 5 to correct the edge shape. By changing the angle θ ₂ of the forming roll 5 with respect to the strip steel and the amount of pushing into the edge portion in the longitudinal direction of the steel strip, the shape of the edge portion can be arbitrarily formed as shown in FIG. 4. Although FIG. 4 shows the processed shape after trimming, it is important that the fractured portion does not protrude from the other surface, that is, the sheared portion A in the width direction.

This is to prevent the fracture portion B from becoming the starting point of cracks due to rolling in the subsequent process. The flange 6 has a function of preventing the occurrence of "curvature" of the end face that occurs when the end face of the strip steel is pushed by the forming roll 5.

Second embodiment: Fig. 5 shows an example in which the forming roll 5 and flange 6 in Fig. 3 are separated to accommodate changes in the thickness of the steel strip, and similarly, an independent forming roll 8 having an angle of θ ₃ is shown. and a presser roll 7, and the basic details of forming are the same as those shown in Fig. 3. In these first and second embodiments, θ ₂ and θ ₃ must each be 0 so that the fracture portion B does not independently protrude to the front.
In other words, it is good if the broken part B is 90 degrees to the width direction of the plate, but in order to make it more stable and reliable, it should be pressed so that it is located inside the plane of the sheared part A in the width direction of the plate. It's clearly better.

Third embodiment: Fig. 6 shows a state in which the grinder 9 is brought into contact with the edge of the steel strip 3 after bevel trimming to grind the fractured part B, and the ground surface is shown in Fig. 7a. so that θ ₄ ≧
It may be 0 degree, or only the surface of the broken part B may be ground as shown in b, and both of these are synonymous with substantially removing the broken part, so the broken part of the present invention is independent. This applies to not protruding to the front.

This grinder 9 can be replaced with another rotating blade or a non-rotating cutting tool.

All of these methods achieve the intended purpose, but according to tests conducted by the present inventors, in view of processing speed, noise, ability, accuracy, etc., indentation molding is preferred in the first and second embodiments. We have confirmed that this is the most practical and effective method.

[Effects of the invention] According to this method, all of the above-mentioned problems can be solved, cutting accuracy and trim width accuracy such as minute trim and partial trim can be improved, and furthermore, end cracking after trimming can be prevented. It is something.

If the steel strip has high hardness, there are special cases in which cracks occur at the trailing edge of rolling even after cutting or shaping into an ideal rectangular cross section. I would like to add that this problem can be solved by using aspects.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a bevel trimmer to which the present invention is applied, FIG. 2 is a diagram showing a cut section by the bevel trimmer of FIG. 1, and FIGS. 3 and 5 are diagrams showing the first,
Figures showing the second embodiment, Figure 4 are Figures 3 and 5.
FIG. 6 is a diagram showing a third embodiment of the present invention, FIG. 7 a,
b is a diagram showing the shape of the ground end surface according to FIG. 6, and FIG. 8 is a diagram showing a conventional conventional trimmer. 1...Upper circular rotary blade, 2...Lower circular rotary blade, 3
...Strip steel, θ ₁ ...Beveled angle, 5 ... Forming roll, 6 ...
...Flange, 7... Push roll, 8... Forming roll, 9... Grinder, A... Shearing section, B...
Broken part.

Claims (1)

[Claims] 1 The upper circular rotary blade of the pair of circular rotary blades is tilted against the longitudinal edge of the metal band plate so as to apply tension in the width direction of the metal band plate to the extent that it can bite into the end face of the metal band plate. (θ), and then, of the upper sheared part A and the lower broken part B that make up the cut surface after trimming, the lower broken part B is either pressed or removed by cutting or grinding. Therefore, a method for processing a longitudinal edge of a band-shaped metal plate is characterized in that processing is performed so that the edge does not protrude to the front surface beyond at least the lower position of the sheared portion A.