JPS6218261B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for passing a steel strip in a spiral mill, which is necessary for continuously delivering a coiled steel strip that is used as a pipe-making material to be supplied to the mill. .

A spiral mill is comprised of a tube-making line that spirally bends and welds a steel strip, and a coil line that unwinds the steel strip obliquely to the line and sends it out to the tube-making line. In order to continuously send out this steel strip, another steel strip coil is prepared in the coil line, and the tip of the trailing steel strip is joined to the rear end of the leading steel strip, making both into one. It is necessary to do so.

Conventionally, in order to join these two steel strips, the spiral mill was temporarily stopped, the feeding of the steel strip was stopped, and the ends of each steel strip were cut in the width direction, and the front and rear ends of both steel strips were butted together. A method of transverse welding is used.

However, with this method, the pipe manufacturing process would be interrupted due to the temporary stoppage of the spiral mill.
There is an inconvenience that welding breaks occur on the inner and outer surfaces of the formed pipe, and the weld seams on the inner and outer surfaces must be repaired after the pipe is cut to a specified length. Further, since the spiral mill needs to be stopped for about 10 minutes for the above-mentioned welding, there are problems such as a decrease in productivity. In view of the above circumstances, it is also conceivable to transversely weld both steel strips while moving a truck carrying a clamping device, a welding device, etc. in synchronization with the delivery speed of the steel plate. However, in cross welding between steel strips, unlike welding of steel pipes, steel bars, etc., it is necessary to cut the crops at the ends of both steel strips in advance, and then weld the front and rear ends of the two steel strips against each other. First, it is extremely difficult to control the speed and position the steel strips when butting them together, which complicates the structure of the cart and makes the work less reliable.

The present invention has been made in order to solve this problem, and it is an object of the present invention to connect the rear end of the steel strip sent to the spiral mill and the leading end of the trailing steel strip to the steel strip without stopping the pipe manufacturing line. The present invention provides a method that allows cross welding to be performed reliably and easily while continuing to deliver the welding material.

The following will explain the embodiments shown in the drawings.
In FIGS. 1 to 4, 1 is a coil line that sends out a steel strip toward a pipe manufacturing line. 2 is a rail laid on the line 1, and 3 and 4 are a rear end truck and a front end truck that run on the rail 2, respectively. The carts 3 and 4 are equipped with coupling machines 5 and 5', respectively. 6 and 6' are steel strips.

In addition, in the center of the rear end trolley 3 and the front end trolley 4,
A clamping device (not shown) that clamps the steel strip and a cutting device (not shown) that cuts the end of the steel strip in the width direction are provided with penetration parts through which the steel strip passes.
Furthermore, the rear end truck 3 is equipped with a cross welding device 7. Note that the clamping device is, for example, a pressing device using a hydraulic cylinder, and the cutting device is, for example, a gas cutting device. Further, the transverse welding device 7 may be provided on the tip truck 4.

Reference numerals 8 and 9 are scrap carts, and the scrap cart 9 on the side of the tip cart 4 on which the scrap obtained by cutting the tip of the steel strip 6' is placed is mounted in a direction perpendicular to the rail 2 (in the upward direction in FIG. 3). ). The scrap cart 8 on the rear end cart 3 side on which the cut scrap of the rear end of the steel strip 6 is placed runs on the rail 2, and at a predetermined position (the position where the rail 2' is laid), a cylinder equipped with lifting wheels 10 is mounted. By operating the device 11, it is detached from the rail 2 and retracted upward on the rail 2' as shown in FIG.

Reference numerals 12 and 12' denote uncoilers, and two uncoilers are provided in order to shorten the time required to unwind the leading end of the coil that becomes the trailing steel strip. The steel strip is fed out by the sub-pinch rollers 13 and 13', respectively, and the feeding speed adjustment, switching operation, etc. are controlled by a control device (not shown). The traveling movement and driving/stopping of the scrap carts 8, 9 as well as the carts 3 and 4 are similarly controlled.

Reference numeral 14 denotes a support which supports the steel strips 6, 6' and is of the type that can be laid down on its side so as not to hinder the movement of the carts 3, 4 and the scrap carts 8, 9.

The present invention is constructed as described above, and its operation will be described next. When the steel strip 6 is sent out toward the pipe production line and its rear end reaches the top of the scrap truck 8 (see Figure 1), the steel strip 6 is clamped by a clamping device provided on the rear end truck 3. At the same time, the ends of the steel strip 6 are cut in the width direction by a cutting device. This clamping and cutting is performed while the steel strip 6 is being sent out toward the pipe production line. That is, the cart 3 and the scrap cart 8 move at the same speed in synchronization with the delivery speed of the steel strip 6 while cutting the steel strip 6.

Meanwhile, in parallel with the above operation, the steel strip 6' is passed through the coil prepared in the uncoiler 12 to the sub-pinch roller 1.
3, and when its tip passes through the cart 4 and reaches the top of the scrap cart 9, the feeding of the steel strip 6' is stopped, and the steel strip 6' is clamped by a clamping device provided on the cart 4. At the same time, the tip of the steel strip 6' is cut in the width direction by a cutting device, and the cut scraps are dropped onto the scrap cart 9. Then, the scrap cart 9 is immediately retracted upward as shown in FIG. When the evacuation is completed, the cart 4 clamping the steel strip 6' is moved toward the pipe production line.

Since this moving speed is faster than the feeding speed of the preceding steel strip 6, the rear end of the preceding steel strip 6 is at a predetermined position, that is, a position appropriately set according to the required time of various operations, and the first The cutting operation has been completed by the time the cutting operation reaches the position indicated by A in FIGS.

Then, the trolleys 3 and 4 are at the A position, and the coupling machines 5 and 5'
The ends of both steel strips 6 and 6' are held so that their abutting state does not change. Next, by operating the welding device 7, transverse welding of both steel strips 6, 6' in the width direction is performed. In addition, at the same time as the bogie 4 comes into contact with the bogie 3, the moving speed of the bogie 4 and the steel strip 6' is synchronized with the delivery speed of the steel strip 6, and before the bogie 3 reaches position A, the bogie 4 and the steel strip 6' are traveling at the same speed as the bogie 3. The scrap cart 8 is located at the rail 2', and by operating the cylinder device 11, the scrap cart 8 is retracted upward as shown in FIG.

Next, as mentioned above, from the time when both bogies 3 and 4 are connected, horizontal joint welding of both steel strips 6 and 6' begins, but this welding is completed by the time bogie 3 reaches the predetermined position B. do. Once the welding is completed, the steel strips 6, 6'
Then, the bogies 3 and 4 and the clamps are released, the steel strip is continuously fed out, the bogies 3 and 4 are stopped, the couplers 5 and 5' are removed, and both bogies 3 and 4 return to their original positions. It happens.

That is, the truck 4 returns to the C position (see FIG. 2), and the truck 3 returns to the D position. In addition, scrap trolley 8
When the trolley 4 returns, the scrap is processed before the trolley 3 returns, and the scrap is returned to the original position by reversing the procedure from when it was evacuated. Further, the scrap cart 9 is also returned in the same manner.

Incidentally, the coil housed in the uncoiler 12' shown in FIG. 4 is connected to the rear end of the coil steel strip 6' of the uncoiler 12, so that it is prepared for the next operation.

Here, in the above-mentioned cross-joint method, cross-joint welding was performed while moving the steel strip without changing the production speed of the pipe manufacturing line, that is, without changing the delivery speed of the steel strip.
If the speed of the pipe production line is slightly slowed only during cross-jointing, it will be possible to provide more leeway for various operations such as cutting, retracting the scrap cart, and welding cross-joints, as well as shorten the length of the coil line. Is possible.

In addition, the scrap cart is arranged to the side of the front and rear end carts, or runs in parallel, so that only its upper body slides to the side, and when cutting, the upper body is positioned within the line and the Upon completion, it may be configured to receive scrap and retreat to the outside of the line, that is, to the side. In addition, in the present invention, the reason why the leading end of the trailing steel strip on the leading end trolley is cut in a stopped state is that cutting machines are mounted on both trolleys, and the leading and trailing steel strips can be cropped at the same time. This means that the distance the rear end cart needs to be moved is short, and that there is plenty of time for the tip cart to catch up after cutting, and that synchronized feeding movement of the tip cart is only necessary during welding. This is because the cropping process of the trailing steel strip can be ensured, and the movement of the scrap cart on the leading end cart side can be simplified.

As described in detail above, the present invention includes a rear end truck, a leading end truck, and two scrap trucks linked to these trucks, which are arranged on the coil line, and the speed of the rear end truck is synchronized with the coil delivery speed. Then, with the leading end cart stopped, the trailing end of the leading steel strip and the tip of the trailing steel strip are cut independently using the steel strip cutting devices installed on both carts, and each scrap cart is evacuated to the side. , the leading end cart with the trailing steel strip in a clamped state is moved at a higher speed than the delivery speed of the leading steel strip, catches up with the leading steel strip, connects both carts, and bumps the ends of both steel strips together. At the same time, cross welding is performed using a welding device installed on one of the trucks. According to this configuration, it is possible to reliably and easily cross-weld steel strips in a spiral mill without stopping the mill, and the steel strips of the coil can be continuously fed out. This has the effect of improving productivity due to improved operating rate, and producing pipes of excellent quality that do not cause weld breaks.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing the method of cross-jointing steel strips in a spiral mill according to the present invention, and shows the state before the start of cross-joining. FIG. 2 shows the same side view. FIG. 3 is a plan view showing the arrangement of each device at the time of completion of the transfer, and FIG. 4 is a side view of the same. 1... Coil line, 2, 2'... Rail, 3
...Dolly for the rear end, 4...Dolly for the tip, 5,5'...
...Coupler, 6, 6'... Steel strip, 7... Horizontal welding device, 8, 9... Scrap trolley, 10... Lifting wheel, 11... Cylinder device, 12, 12'...
Uncoiler, 13, 13'...Sub pinch roller.

Claims (1)

[Claims] 1. On the coil line that sends out the steel strip toward the pipe production line, place a rear end cart and a tip cart that are formed to penetrate the steel strip and have a steel strip clamping device and a steel strip cutting device. A welding device is mounted on one of both carts, and two scrap carts are installed in conjunction with each cart, and the rear end of the leading steel strip and the tip of the trailing steel strip are cut and then butt welded. Then, the rear end cart and the scrap cart on the side of the cart are moved at the same speed as the steel strip delivery speed, and the rear end of the preceding steel strip on the rear end cart is clamped and cut while the steel strip is being delivered. Then, the scrap cart is retracted to the side at a predetermined position, while the tip of the trailing steel strip on the tip cart is clamped and cut in a stopped state, and then
The scrapping cart on the tipping cart side is retracted to the side, and then the tipping cart with the trailing steel strip in a clamped state is moved at a higher speed than the delivery speed of the leading steel strip, catching up with the leading steel strip and moving both carts. 1. A method for transversely joining steel strips in a spiral mill, the method comprising: connecting the two steel strips, butting the ends of the steel strips, and maintaining this state to perform cross welding using the welding device.