JPS63120013A - Slit distortion decreasing method for slitting material - Google Patents

Abstract

PURPOSE:To decrease the extent of slit distortion, by controlling an angle at which a slit strip comes into contact with a stripper, and giving it longitudinal bending deformation and reverse bending deformation both to be given to a slit edge just after biting. CONSTITUTION:In order to make a pass line of the broad metal belt 1 so far entered from the inlet side turn upward at a biting position, a slit strip receives longitudinal bending deformation for top compression. In succession, this strip is pushed up by a lower round blade 5', making it contact with the stripper 14 set up as tilted at a certain angle to horizontal line. And, it is advanced to the slitter outlet side as receiving bending deformation for underside compression such as offsetting forward bending deformation in the quite reverse direction to the bending deformation received at the biting position. Therefore, after slitting, there is no residual stress in the longitudinal bending deformation of a slit strip edge. So, a roller leveler leveling process is made unnecessary, thus quality is sharply improvable.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a method for reducing slit distortion that occurs in a hoop material obtained by cutting a wide metal strip (such as a cold-rolled steel plate) into a predetermined width using a slitter, and in particular to The present invention relates to a method for effectively reducing shape defects of processed products, so-called slit distortion, which occur due to residual stress entering the vicinity of parts.

Prior Art and its Problems A common method for cutting a wide coiled cold-rolled steel plate into narrow hoops is to use a gang slitter as shown in FIGS. 4a and 4b. The gang slitter continuously slits a wide coil into a narrow hoop material (11) by shearing using rotatable upper and lower round blades (505') set at predetermined intervals on the upper and lower arms (6) (6°). It is something to do.

The hoop material cut to a predetermined width by this gang slitter is used for various purposes, but when the hoop material is processed into an E shape that includes slit edges, for example, the shape is defective as shown in Figure 5. , that is, the slit edge part (1
1-1) (11-2) may warp in the longitudinal direction and the product may not be flat. These shape defects do not occur at all when, for example, the same width is cut with a shear and the same E-shaped stamping is performed.This is a phenomenon specific to slitting using a rotating knife, and is caused by residual stress during slitting. Since this is thought to be the cause, it is generally called slit distortion. Furthermore, since slit strain disappears when a region 2 to 4 times the plate thickness is removed from the slit edge by corrosion, for example, the residual stress that enters during slitting is thought to be due to residual stress concentrated at the slit edge. .

Hereinafter, the formation and opening groove of slit distortion will be briefly explained.

As mentioned above, Fig. 4(a) is a side view of a commonly used slitter, in which round blades (5) (5') are installed on the upper and lower arms (6) (6') according to the slit width of the hoop material. It is placed. The vertical rotating round blade is arranged on the arm with a horizontal gap C (hereinafter referred to as clearance, S) and a vertical overlap 2 (hereinafter referred to as overlap amount) between the upper and lower round teeth as shown in Fig. 4(b). be done. In addition, when the overlap amount is very small, there is little danger, but if the amount of overlap becomes large, the narrow hoop material (1) after separation will wrap around the round blade, so it is necessary to prevent it from wrapping around the round tooth. The stripper (4) is installed almost horizontally.

Considering the symmetry of the slitter, the formation mechanism of slit distortion will be explained by taking as an example the strip cut up by the upper round blade.As shown in Figure 6(a), the wide metal strip (1) entering from the entrance side of the slitter is At point A, it is bitten by the vertically rotating round blade, and after being cut up by the upper round blade, it is separated from the upper round blade (5) by the stripper (4). During the slitting process, the edge of the slit strip is forced to suddenly change its path line upward due to the biting position. Here, the radius is given by R: radius of the round blade 2 degrees, amount of overlap t: thickness of the wide metal band.

That is, the edge portion of the slit strip receives a moment MA of upper surface compression at the biting position. MA is the size of the army;
That is, it varies depending on the radius R of the round blade, the amount of overlap, and the thickness t of the wide metal strip, and the larger the overlap ti is, the smaller the radius R of the round blade is, the larger MA becomes. After that, the hoop material (11
The edge part of ) takes a different path line depending on the set position of the stripper (4) and the amount of overlap 2, but generally it contacts the stripper and receives a bending moment in the opposite direction to MA, that is, a bending moment M8 of lower surface compression. become. The magnitude of the bending moment Me that the hoop material receives during stripping is determined by the setting position of the stripper,
It depends on the amount of overlap 2. For example, even if the amount of overlap is the same, if the stripper is set near the center line in Fig. 6, the contact angle during stripping becomes larger and Me also becomes larger, and in some cases, MA < It may become ME3. On the other hand, as shown in FIG. 6(b), the pass line at the center of the hoop material is not directly constrained by the vertically rotating round blade, so it takes a gentle pass line compared to the slit edge.

As described above, the edge of the hoop material is deformed in the longitudinal direction by the bending moment MA at the biting point of the vertically rotating round blade @ point A, and then the edge is warped upward in the longitudinal direction by the bending moment MA, and then the edge is bent upward in the longitudinal direction
At this point, the bending moment Ma causes a downward warpage in the longitudinal direction.

As mentioned above, the deformation of the center part of the hoop material is gradual deformation relative to the slit edge part, so if the hoop material is processed into an E-shaped product that includes an edge, and the slit edge is separated from the center part, the slit edge Of the upward warping deformation at point A and the downward warping deformation at 8 points that were received during the slitting process, elastic recovery occurs in the direction of the larger deformation, resulting in a longitudinal warpage shape defect.

In order to reduce these shape defects, conventional methods have been used to apply unbending deformation using a roller leveler after slit processing to reduce the residual stress at the slit edge. However, the hoop material, which has a large residual stress at the slit edge, can be bent in the longitudinal direction using rollers with the same diameter in the board width direction.

It is inefficient to reduce residual stress by repeating bending and unbending, and work hardening due to bending and unbending extends to the entire hoop material, which is not preferable.

The present invention has been made in consideration of the above-mentioned conventional problems, and an object of the present invention is to propose a slit distortion reduction method that can omit the leveling step.

Means for Solving the Problems This invention solves the above-mentioned problems of the prior art by providing a stripper that can be tilted at any angle vertically with respect to a horizontal line, and adjusting the angle at which the slit strip contacts the stripper during slitting. The present invention proposes a slit strain reduction method that is characterized by applying longitudinal bending deformation in a direction completely opposite to the longitudinal bending deformation applied to the slit edge immediately after biting.

The present invention will be explained below based on the drawings.

FIG. 1 is an explanatory diagram showing one embodiment of the present invention, (14)
shows the stripper, with two support arms (15)
(16) with both ends pivotally attached to one support arm (15).
) is pivotally connected to the fixed base (17) with a pin (18), and the other support arm (16) is connected to the fixed base via a guide pin (19) loosely fitted in the elongated hole (16-1). The inclination angle of the stripper (14) with respect to the horizontal line can be arbitrarily set by moving the support arm (16) with an elongated hole back and forth. That is, by tilting the stripper (14) at an arbitrary angle θ with respect to the horizontal line, it is possible to control the angle at which the slit strip contacts the stripper. Therefore, by controlling the inclination angle of the stripper (14), it is possible to provide a bending deformation in the opposite direction that offsets the bending deformation in the longitudinal direction that the slit edge receives at the biting position. This is a method to eliminate the warpage of the edges afterward.

That is, depending on the material of the wide metal band (1), the amount of overlap 2, the rotary round blade diameter R1 and the wide metal band thickness t, the traveling direction of the edge pass line at the biting position of the upper and lower round blades (5) (5') The magnitude of the warpage in the longitudinal direction due to the sudden change in the shape of the slit after cutting and separation is determined. This method adjusts the contact angle between the edge portion and the stripper (14) and imparts a bending deformation to the slit strip in a direction completely opposite to the bending deformation in the longitudinal direction at the biting position that the slit edge receives when it comes into contact with the stripper. be.

Function: Due to the symmetry of the slitter, the hoop material is cut up to the upper round edge (5°). As shown in Figure 1, the wide metal strip (1) that enters from the entry side passes through the slitter at the biting position. Since the line is changed upward by the force, the slit strip undergoes longitudinal bending deformation due to upper surface compression. Subsequently, the slit strip is pushed up to the upper round blade (5°) and contacts the stripper (14) installed at an angle θ with respect to the horizontal line, causing a bending deformation that is completely opposite to the bending deformation received at the biting position. The slitter advances toward the exit side of the slitter while being subjected to bending deformation due to downward compression that offsets the forward bending deformation in the direction. After slitting, there is no residual stress due to longitudinal bending at the edge of the slit. Therefore, for example, even if an E-shaped product including edges is pressed, the flatness of the E-shaped product will deteriorate. There is no warpage at the slit edge.

EXAMPLE Using the apparatus shown in FIG. 1, slitting was carried out under the conditions shown in Table 1. Note that the conventional method has the same conditions as the present invention except for the setting conditions of the stripper.

The hoop material obtained by slitting under the conditions shown in Table 1 was punched into the E shape shown in FIG. 2, and the flatness of this E shape product was investigated. The results are shown in FIG.

In addition, the dimensions of each part of the E type product are -1:50 mm, W
2: 3mm, W3: 5mm, W4: 97.5
mm, Wo: 117.5 mm.

From the results shown in FIG. 3, by controlling the contact angle between the slit strip and the stripper by attaching an angle θ to the stripper, the warpage of the slit edge after striking was reduced, and the leveling process became unnecessary. In particular, in the range where the overlap amount 9 was large, the amount of warpage was significantly improved to about 1/10.

As explained in detail in Table 1 of the invention below, the method of this invention completely eliminates the longitudinal bending deformation imparted to the slit edge immediately after biting by controlling the angle at which the hoop material contacts the stripper after slitting. Since this method reduces the residual stress at the slit edge by applying the opposite deformation, there is no need for a roller leveling step in which the width of the slit material is subjected to work hardening, resulting in a significant improvement in quality.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing one embodiment of the present invention, Fig. 2 is an explanatory diagram showing an E-shaped product in the embodiment of the invention, Fig. 3 is a diagram showing flatness in the same embodiment, Fig. 4 1 is a diagram showing a gang slitter to which the present invention is applied; FIG. 5 is a side view, FIG. 5 is a front view, FIG. These are explanatory diagrams showing the mechanism, in which Figure a shows a pass line at the edge of the slit strip, and Figure a shows a pass line at the center of the slit strip. 5... Upper round blade, 5°... Upper round blade, 14... Stripper, 15, 16... Support arm, 16-1...
Long hole, 11...fixing base, 18...pin, 19...
guide pin. Applicant: Sumitomo Metal Industries, Ltd. Figure 2 Figure 3 Overlap amount l (parrot) Figure 6 (a) \, R (b)

Claims (1)

[Claims] In a method of continuously cutting a wide metal strip into narrow hoop materials, a stripper is provided so as to be tiltable at any angle in the vertical direction with respect to a horizontal line, and the angle at which the slit strip comes into contact with the stripper is controlled. A method for reducing slit strain in a slit material, characterized by applying bending deformation in the direction completely opposite to the bending deformation in the longitudinal direction given to the slit edge immediately after the slit is bitten.