JPH0576911A - Method and device for notching steel sheet - Google Patents

Abstract

PURPOSE:To provide a method and device for notching edges in the breadthwise direction in a joined part between steel sheets without making the equipment larger and local temp. drop of steel 5 sheets at the time of continuously rolling a steel plates which the rear end of a preceding steel sheet and the tip of the following steel sheet are joined. CONSTITUTION:The joined part 31 of the steel sheet 3 which travels on a rolling line is clamped from both sides with a roll 1 with a circular-arcuate projecting part 11 and a roll 2 with a circular-arcuate notched part 21 corresponding to that projecting part 11 and the circular-arcuate notchs are formed at edges in the axial direction of the joined part 31 by utilizing the traveling power of the steel sheet 3 by this method. And, this notching device has the paired upper and lower rolls which respectively have a bisected shape in the breadthwise direction, respective divided rolls are connected with one shaft and the intervals between the respective upper and lower rolls are variable.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for forming a notch (hereinafter also referred to as notching) in a widthwise end portion of a joining portion between a preceding steel plate and a following steel plate in a continuous rolling line.

[0002]

2. Description of the Related Art In recent years, predetermined dimensional accuracy and quality have been required even at the leading end and the trailing end of a hot rolled steel sheet. As a technology that dramatically improves the dimensional accuracy and quality of the leading and trailing edges of the steel sheet, we have developed a technique for improving the dimensional accuracy and quality of the leading and trailing steel sheets between the rough rolling mill group and finishing mill group of the hot rolling line. A technique for joining the tip and continuously finishing rolling is being developed.

In this case, the widths of the preceding steel plate and the following steel plate are usually different from each other, and the plate width difference at the joining portion causes a threading trouble in the rolling line. As a countermeasure against this, the present applicant has proposed a joining portion trimming method in which arcuate notches are formed at both end portions in the plate width direction of the joining portion, as disclosed in JP-A-63-115605. This method uses a die for arc-shaped projections and notches at the latter stage of the joining machine installed between the group of rough rolling mills and the group of finishing rolling mills, and presses them at both ends in the plate width direction of the joints by pressing. By the method of forming the notch,
Since the plate width step at the end of the joint is smoothly cut and stress concentration is relieved, smooth continuous hot rolling without trouble can be performed.

However, the method of making a notch by this pressing method has the following problems. That is, (1) The pressing load is large and the equipment is expensive.

(2) When the steel sheet running on the rolling line is temporarily stopped and subjected to press reduction, the temperature drop of the steel sheet becomes large. On the other hand, in the case of pressing down the steel plate without stopping it, it is necessary to run the press and the equipment becomes larger.

(3) Since the contact area between the die and the steel sheet during pressing is large and the contact time is long, the local temperature drop of the steel sheet becomes large and the quality of the steel sheet deteriorates.

[0007]

DISCLOSURE OF THE INVENTION The present invention, when continuously rolling a steel sheet in which the trailing edge of the preceding steel sheet and the leading edge of the following steel sheet are joined, does not involve the enlargement of equipment and causes a local temperature drop of the steel sheet. It is an object of the present invention to provide a method and an apparatus for notching the end portion in the plate width direction of a steel plate joint without the use.

[0008]

The gist of the present invention resides in the following notching method and apparatus for steel sheets.

When continuously rolling a steel sheet in which the trailing edge of the preceding steel sheet and the leading edge of the trailing steel sheet are joined, the joining portion of the steel sheets traveling on the rolling line is formed by a roll having arc-shaped projections and this projection. Characterized in that it is sandwiched by a pair of rolls composed of a roll having an arcuate notch corresponding to the section from above and below to form an arcuate notch at the widthwise end of the steel plate joint. Steel plate notching method.

A roll having arcuate protrusions and a roll having arcuate notches corresponding to the protrusions are arranged vertically at both ends of the steel plate with the steel plate sandwiched therebetween, and the upper roll and the lower roll at both ends are arranged. A notching device for steel plates in which the side rolls are connected by a single shaft, and the distance between the rolls at the upper and lower ends is variable.

The above-mentioned arc-shaped protrusion means a protrusion having an outline of the protrusion or an arc-like shape. The height of the protrusion is 1.0 to 2.0 times the thickness of the steel plate,
The length of the protrusion from the steel plate side edge is preferably 0.5 times or more the plate width difference between the preceding steel plate and the trailing steel plate, and in particular, the tip has a semi-circular shape with a radius of 0.5 times the plate thickness difference. Is most desirable.

The arcuate notch corresponding to the protrusion is slightly larger than the protrusion and has the same shape as or similar to the protrusion, and a steel plate is sandwiched between the upper and lower rolls for joining. A notch portion provided so that a notch can be formed at the end portion in the width direction of the portion.

[0013]

According to the present invention, as described above, a steel plate traveling on a continuous rolling line is sandwiched by rolls from above and below, and the rolls are rotated by the traveling force of the steel plates. Similarly, it is a method and an apparatus for notching a widthwise end portion of a joint portion of steel plates with a notch portion provided in a roll.

FIG. 1 is a perspective view of an example of a roll portion (hereinafter referred to as a notcher 5) of a notching device for carrying out the invention of the present invention. Notcher 5
Is an upper roll 1 having arcuate protrusions 11 at both ends in the width direction, and the arcuate protrusions 11 at both ends in the width direction as well.
The lower roll 2 has an arcuate notch portion 21 corresponding to. Joints 31 of steel plate 3 traveling on the rolling line
When approaching the notcher 5, as shown in the figure,
The steel plate 3 is sandwiched between the upper and lower rolls 1 and 2, and the roll is rotated in the direction of the arrow by the running force of the steel plate 3 to cut the joint 31 near both ends 32 in the plate width direction as shown in FIG. Lack 4
Put in.

The operation of the notcher shown in FIG. 3 will be described in more detail with reference to the schematic view. FIG. 3A shows a state in which the upper roll 1 and the lower roll 2 are separated from the steel plate 3 before the joint portion of the traveling steel plate 3 approaches the notcher 5. (b)
Detects that the joint 31 is approaching the notcher 5 and sandwiches the steel plate between the upper and lower rolls 1 and 2, and the rolls 1 and 2 rotate in the direction of the arrow due to the traveling force of the steel plate. Notching is started as shown in FIG. An optical width meter, for example, is used as the method of detecting the joint portion.

Thus, the plate width step portion is detected, and the expected notch position is calculated from the distance between the width meter and the notcher and the steel plate traveling speed. (d) shows a state in which the notch material 6 cut by the notcher 5 has fallen into the notch portion 21 of the lower roll 2. When the rolls 1 and 2 rotate further, the notch 6 falls as shown in (e). After that, when the upper and lower rolls 1 and 2 are separated from the steel plate 3 as shown in (f), the rolls stop rotating, and the upper and lower rolls 1 and 2 become (by the time the next joint portion approaches the notcher 5). Align so that the state (stop position) shown in a) is reached.

FIG. 4 is a front view showing the structure of the roll portion of the notching device of the invention of FIG. 4, in which the upper and lower rolls used when carrying out the invention of FIG.
The divided upper and lower rolls (1a and 1b and 2a and 2b) are connected to each other by one shaft 13. Moreover, a mechanism is provided so that the distance between the upper and lower rolls (the distance between 1a and 1b and the distance between 2a and 2b) can be adjusted according to the width of the steel plate 3. If such a roll is used, the most suitable notch can be formed according to the plate width. The present inventor was able to make notches corresponding to a plate width of 650 to 1850 mm by using such a split roll.

In the notching device of the present invention, a simple drive mechanism for aligning the roll stop position is required, but since the cutting force is used to cut the steel sheet, a large drive mechanism is not required, and the equipment is not required. It can be simplified.
Further, since the roll is pressed against the traveling steel plate to rotate the roll, the roll peripheral speed is synchronized with the traveling speed of the steel plate, and it becomes possible to perform notching without reducing the steel plate speed. Further, as shown in FIG. 3, the roll and the steel sheet are always in linear contact with each other, and the temperature drop of the steel sheet hardly occurs.

Although the above description has been made with respect to a notcher attached to a hot rolling line, the present invention is not limited to this.
It can also be applied to notches such as cold rolling lines and pickling lines.

[0020]

EXAMPLE A hot rolling line equipped with the notching device of the present invention shown in FIG. 5 has a plate thickness of 30 to 40 mm and a plate width of 1100 to 1300.
The steel plate 3 of mm was hot-rolled. The notching device used, as shown in FIG. 6, has a pair of upper and lower rolls having a roll diameter of 1000 mm and a roll barrel length of 1400 mm.
Each end of the roll has a radius of 100m in the roll length direction.
A semicircular length of 200 mm and a height of 50 mm are provided with protrusions 11, and notches having a depth of 55 mm corresponding to the protrusions 11 in the roll length direction are provided at both ends of the lower roll 2. 21 are provided.

In the above hot rolling line, the steel sheet 3 was first rolled by the rough rolling mill group 7 and once wound into a coil by the coil box 8. Next, the front end of the rewound steel plate 34 and the rear end of the preceding steel plate 33 are heated by a joining machine 9 with a reducing flame and then joined by superposition pressure welding, and the notcher 5 of the present invention shown in FIG. A notch was made (see Figure 7). As shown in FIG. 6, the notched steel plate 3 has a plate width difference of 100 mm at both ends and a total of 200 mm. This steel plate 3
Was continuously rolled by the finishing rolling mill group 12, but there was no trouble. On the other hand, if you do not insert the notch,
When the plate width difference between the preceding steel plate and the following steel plate was 50 mm or more, problems such as breakage occurred at the plate width end of the joint.

When a conventional press reduction type notcher is used, the contact time between the press die and the steel plate is 0.2.
It is as long as ~ 0.5 seconds, and the local temperature drop of the steel sheet is several tens of degrees Celsius, but when the notcher 5 of the present invention is used, the temperature of the steel sheet is measured by a thermometer 10 installed behind the notcher 5. The temperature drop of the steel sheet was hardly observed.

In this embodiment, superposition pressure welding was used as the joining method, but the method of the present invention could be similarly applied to butt joining.

[0024]

When continuously rolling a steel sheet in which the trailing edge of the preceding steel sheet and the leading edge of the trailing steel sheet are joined, if the method of the present invention is applied, the widthwise end portion of the joining portion can be obtained without stopping the running of the steel sheet. Can be notched, and local temperature drop of the steel sheet can be prevented.

The device of the present invention can form the most suitable notch according to the plate width and uses the running force of the steel plate, so that it is inexpensive without increasing the size of the equipment.

[Brief description of drawings]

FIG. 1 is a perspective view of an example of a notcher for carrying out the method of the present invention.

FIG. 2 is a perspective view of a steel plate having a notch formed by the method of the present invention.

FIG. 3 is a schematic diagram illustrating the function of a notcher used to carry out the method of the present invention.

FIG. 4 is a front view of the notcher of the present invention.

FIG. 5 is a schematic view of a hot rolling line used in an example of the method of the present invention.

FIG. 6 is a perspective view of a notcher used in an example of the method of the present invention.

FIG. 7 is a perspective view of an example of a steel plate having a notch in the embodiment of the method of the present invention.

Claims (2)

[Claims] 1. When continuously rolling a steel sheet obtained by joining the rear end of a preceding steel sheet and the leading end of a following steel sheet, the joining portion of the steel sheets traveling on a rolling line is formed by a roll having arc-shaped projections. It is sandwiched from above and below by a pair of rolls composed of a roll having an arcuate notch corresponding to this protrusion,
A notching method for steel plates, characterized in that arc-shaped notches are formed at the widthwise ends of the steel plate joints. 2. A roll having arcuate protrusions and a roll having arcuate notches corresponding to the protrusions are vertically arranged with the steel sheet sandwiched between both ends of the steel sheet, and the upper rolls at both ends. A steel plate notching device in which the lower roll and the lower roll are connected by a single shaft, respectively, and the distance between the rolls at both ends of the upper and lower rolls is variable.