JPS6047001B2 - Rolling method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for rolling metal by reversing the work rolls of a rolling mill every bus.

As shown in FIG. 1, winding and unwinding machines 3 and 4 are arranged before and after the reversing rolling mill 1, and the electric motors of the work rolls 2 and 2 and the motors of the winding and unwinding machines 3 and 4 are installed for each bus. In the method of rolling metal by reversing the winding and unwinding machines, the winding and unwinding machines 3 and 4 are equipped with a number As shown in Figure 2, the coil winding part 13 is divided into several segments 10.
The inner surface of the segment 10 and the mandrel shaft 11 are formed into a serrated shape and combined, and a hydraulic cylinder 12 is provided at the rear end of the mandrel shaft 11, and the coil winding portion 13 is formed by the extension operation of the hydraulic cylinder 12. An expanding/contracting mandrel having a structure that can be expanded and contracted as appropriate is used, and as shown in FIGS. 2 and 3, the mandrel shaft 11 moves forward and the coil winding part 13 is expanded, and then the metal strip 6 is wound and wound. When the winding operation is performed by applying a large winding tension in order to perform the return operation, as shown in FIG. This reel mark 15 occurs at about 1 turn in a normal plate thickness, and up to several 10 turns in the case of a thin plate, resulting in a deterioration in the quality of the product and a very poor yield.

In addition, when winding the metal strip directly around the expansion mandrel to perform the winding operation for rolling as described above,
In general, the greater the tension per unit area applied to the metal strip, and the more oil is attached to the surface of the metal strip, the greater the tightening force (the more the coil acts toward the inside of the coil). The non-contact portion 16 between the segment 10 and the mandrel shaft 11
(See Figure 2) The segment 10 will warp due to the bending force applied to it, and in extreme cases there is a risk that the segment 10 will be damaged. A hydraulic cylinder is required.

On the other hand, applying as much tension as possible to the metal strip requires less rolling load and produces a product with a good shape. Also, if the work rolls have the same diameter, applying as much tension as possible is better than applying less tension. It is generally known that thin products can be rolled, and for this reason, as shown in Figure 5,
Winding and unwinding machines 18 and 19 equipped with solid mandrels are installed before and after the multi-high rolling mill 17, and these solid mandrels perform the winding operation under high tension to eliminate the drawbacks of using the expansion and contraction mandrels described above. A method of rolling a product with a good shape is being considered.

However, in such a method, the rolling equipment becomes large-scale and the equipment becomes bulky, and the work of winding the raw material coil from the unwinding machine 21 equipped with the expansion/contraction mandrel onto the solid mandrel of the winding unwinding machine 18 on the entry side and the product are required. It is necessary to wind the coil from the solid mandrel of the take-up and unwind machine 19 on the exit side using the winding machine 22 equipped with an expansion/contraction mandrel, which is not efficient, and because there are many driving sources, it consumes a lot of energy. There are drawbacks such as increased product cost. In the figure, 23 indicates a coil car. In order to compensate for this drawback, a method has been considered in which the product coil is wound up in the final stage of rolling by the winding and unwinding machine 24 that unwinds the material coil at the start of rolling, as shown in FIG. However, unless the product coil is taken out, preparations for the next rolling cannot be made, and the problem of inefficiency remains unresolved.

In order to solve the above-mentioned problems with the rolling method, there is a method in which winding is performed using a mandrel fitted with a sleeve, and the product coil is taken out together with the sleeve when rolling is completed. Not only does the product cost increase because the sleeve must be prepared, but it also reduces the cost of the next process.
For example, there are disadvantages such as poor work efficiency because the sleeve must be taken out and transported on the shearing line, and when the coil is annealed in the next step, the sleeve is also annealed, resulting in severe wear and tear on the sleeve.

The rolling method of the present invention was developed to solve the problems in the various rolling methods described above, and includes winding and unwinding machines equipped with an expanding and contracting mandrel having a coil winding section that expands and contracts, and is arranged before and after the rolling mill. , the sleeves are fitted and fixed on both expansion and contraction mandrels, the rolling mill work rolls and both expansion and contraction mandrels are reversed every bus, and the metal strip is wound and unwound by both expansion and contraction mandrels, and the metal strip is rolled between the rolling mill work rolls. This method is characterized in that the plate is rolled a required number of times, and then the sleeve is removed from one of the winding and unwinding machines, and the metal strip is wound directly around the expansion/contraction mandrel and wound up.

A first embodiment of the present invention will be described below with reference to FIGS. 1, 7, and 8. The take-up and unwind machines 3 and 4 and the unwind machine 5 on the entry and exit sides are each equipped with an expanding and contracting mandrel having the structure shown in FIG. Prior to starting rolling, a sleeve 25 is fitted onto each of the four expanding and contracting mandrels as shown in FIGS. 7 and 8.

In FIGS. 7 and 8, 6 is a metal strip, 10 is a segment, 11 is a mandrel shaft, 26 is a key, 27 is a slit-type grip, and 28 is a bearing. After that, the metal strip 6 of the material coil inserted into the expansion/contraction mandrel of the unwinding machine 5 is unwound, and its tip is passed between the work rolls 2, 2 of the reversing rolling mill 1 for winding and unwinding on the exit side. After winding the sleeve 25 of the machine 4 using the slit-type grip 27, the work rolls 2, 2 are driven while being wound with high tension by the take-up and unwind machine 4 on the exit side. Start rolling.

When the rolling of the first stage progresses and the tail end of the metal strip 6 separates from the unwinder 5, the winding operation is temporarily stopped and the tail end of the metal strip 6 is moved to the sleeve of the winder and unwinder 3 on the entry side. 25 into the slit-type grip 27 and wind it, and then the take-up and unwinder 4 on the exit side.
By the winding operation, high tension is again applied to the metal strip 6, and the work rolls 2, 2 are reversed to carry out second-stage rolling. Thereafter, the work rolls 2, 2 and the take-up and unwinders 3, 4 on the inlet and outlet sides are reversed for each bus to repeatedly roll at least the other buses except for the last bus, and the buses in the stage before the last bus are rolled. Once this is completed, the winding operation is temporarily stopped.

When the last bus corresponds to an odd number of times, the metal strip 6 has already been wound by the take-up and unwinder 3 on the entry side when the previous stage of rolling is completed, so the tip of the metal strip 6 is rolled up on the exit side. After separating it from the sleeve 25 of the unwinding machine 4, the key 26 is removed and the sleeve 25 is taken out from the mandrel shaft 11, and it is placed in a predetermined place using a known method such as a coil car 9 or another sleeve removal and installation device. Then, the tip of the metal strip 6 was directly wound around the expansion/contraction mandrel of the take-up/unwinder 4 on the exit side, so that no reel marks were left on the metal strip 6, and the product coil was removed from the expansion/contraction mandrel. The final stage of rolling is sometimes performed at a tension that does not crush the inner diameter of the coil and does not damage the segments of the expansion/contraction mandrel. The product coil wound onto the expansion and contraction mandrel of the winding and unwinding machine 4 on the exit side during the final stage of rolling is caused by the contraction operation of the segments 10 accompanying the backward movement of the mandrel shaft 11 of the expansion and contraction mandrel. It is taken out by the expansion/contraction mandrel and transported by the coil car 9 which has been waiting. In this way, in the present invention, while the sleeve is being fitted onto the expansion mandrel, there is no risk of leaving reel marks on the metal strip or damaging the segments, so rolling can be carried out at high tension, and the sleeve is being fitted. Since the final bus is wound with a non-expanding mandrel, the work of removing the product coil is simple and efficient. still,
In the present invention, at least in the bus preceding the final bus, all the coils must be unwound from one mandrel, the sleeve must be removed, and then the coils must be wound around the expansion mandrel again, which somewhat reduces work efficiency. However, it is best to change the ends of the coil once when at least the previous stage of the last bus out of multiple buses is completed, and when using a reversing rolling mill, the work of changing the ends of the metal strip can be done at least once at the end of the last bus. It is inevitable that there will be some parts that are not removed, that is, parts that do not become a product, so if you cut them off at this time, it will save you the trouble of cutting them out in the next process.
There are no problems whatsoever.

The cutting operation of the front and rear ends of the metal strip may be performed using a shear built into the rolling mill, or may be performed using a portable shear. The cut and scrap material may be removed together with the sleeve or may be removed separately. It should be noted that the rolling method of the present invention is not limited to the above-mentioned embodiments, and the coil cars do not necessarily have to be provided on both sides; in short, they may be provided below the expansion and contraction mandrel on the side from which the sleeve is removed during final bus rolling. In addition to the slit type grip, the grip may be of the type using a ratchet, and in the above embodiment, since the frictional force between the sleeve and the expansion mandrel alone is insufficient, a key is used to apply torque from the expansion mandrel to the sleeve. Although the transmission is ensured, the position of the key is not limited to the position shown in the figure; it may be placed between the inner periphery of the sleeve and the expansion mandrel, or between the end of the expansion mandrel and the end of the sleeve. Of course, this can be done.

According to the rolling method of the present invention, i It is possible to roll products without reel marks.

11. Damage to the mandrel due to strong tension is eliminated.

1i No need for large expansion and contraction cylinders to counter strong tensions.

Since rolling can be performed while applying strong tension,
The rolling load is reduced and products with good shapes can be rolled.
With the same work roll diameter, thinner products and harder materials can be rolled.

■ Compared to methods using solid mandrels, equipment costs are lower, work efficiency is better, and energy consumption is lower.

■ Compared to the conventional system using sleeves, the number of sleeves can be reduced and damage to the sleeves is less.

It has excellent effects such as

[Brief explanation of the drawing]

Figure 1 is an overall view of the reversing rolling equipment, Figure 2 is a vertical cross-sectional view of the expanding and contracting mandrel used in the winding and unwinding machine, Figure 3 is a view taken in the direction of the ■ arrow in Figure 2, and Figure 4 is the An enlarged view of part ■ in the figure, Figures 5 and 6 are general views of the reversing rolling equipment when the winding and unwinding machine is equipped with a solid mandrel, and Figure 7 is a diagram used in the rolling method of the present invention. FIG. 8 is a side view of the mandrel of the winding and unwinding machine. 1 and 17 are reversing rolling machines, 2 is a work roll, 3 is a take-up and unwinder on the input side, 4 is a take-up and unwinder on the output side, 5 is a raw material coil unwinder, and 6 is a metal strip plate. , 7, 8, 9, 23, 41, 42
10 is a coil car, 10 is a segment, 11 and 11a are mandrel shafts, 12 is a hydraulic cylinder, 13 is a coil support portion, 25 is a sleeve, and 26 is a key.

Claims (1)

[Claims] 1. A winding and unwinding machine equipped with an expansion mandrel having a coil winding part that expands and contracts is arranged before and after the rolling mill, and sleeves are fitted and fixed to both expansion and contraction mandrels, and the rolling machine work roll and both expansion and contraction mandrels are connected to one Reversing each pass, the metal strip is wound and unwound by both expansion and contraction mandrels, and the metal strip is rolled the required number of times between the work rolls of the rolling mill.Then, the sleeve is removed from one of the winding and unwinding machines and expanded and contracted. A rolling method characterized by winding a metal strip directly around a mandrel and winding it up.