DE575179C - Rolling mill for metal sheets, strips and rods - Google Patents

Description

Rolling mill for metal sheets, brackets and rods The invention is pursued the purpose of simplifying the rolling of metal sheets, strips and bars and abbreviate. Up to now, thin sheets and strips have been manufactured on rolling mills, which are known in the art as duo, trio or multi-roller mills.

The rolling mills are built from the point of view of the whales on the one hand withstand the great pressure that occurs during rolling and on the other hand can absorb the torque to be transmitted. As a result of this stress relatively large diameter for the rollers. Give large roller diameters good grip on the rollers, d. H. they exert a great deal of pulling force on the rolling stock off, but complicate the deformation work, d. H. the achievement of large cross-sectional reductions of the rolling stock, which is ultimately the real purpose of rolling.

For some time there has therefore been a move towards closing rolling mills use that are built to use the driven work rolls or some of them are relatively very small in diameter, which eliminates the work of deformation is facilitated. The rolling pressures that occur are thereby reduced by stronger backup rolls added, so that the work rolls essentially only what is necessary for rolling Have to transmit torque. The reduction in diameter of the work rolls has However, their limits are that the gripping ability of the rolls when reducing the diameter decreases sharply, so that only very thin material, for example rolling stock from 2 mm thickness downwards; / rolled on such rolling mills with economic advantage can be. It has been suggested that such rolling mills have good gripping properties to forego and not the rolling stock through these powered rolling mills to roll through, but to pull through by running the rolling mills without a drive and winds the rolling stock on a driven reel (in the case of strip-shaped rolling stock) or as with a draw bench, grabs with tongs and pulls it straight away from the rolling mill (for strips, boards, etc.).

In this method, however, has the major disadvantage that the relatively thick rolling stock must either first be sharpened so thin that it is through the Rolls can be pushed through, or that you first of all in the rolling mill Roll gap must increase so that the rolling stock over a certain length through can push through the nip, then the rolling mill must compress and Now only grasp the rolling stock with the grippers or the like and pull it through the rollers can. These procedures require either a considerable amount of extra work or a proportionate amount of work big waste by that non-rolled starting piece of the rolled stock, which is disruptive to economic work, especially with larger rolled stock thicknesses makes noticeable.

According to the invention, the machine is now with one or more the pulling power for the rolling mills A with large roll diameters that produce the rolling stock Mistake. These large rollers then pull the rolling stock through the one or the other as well existing rolling mills B with a relatively small diameter therethrough. These Rolling mills B with a small diameter can be without a drive or with one Be provided with auxiliary drive. The auxiliary drive is preferably designed to be elastic, z. B. by a slip clutch is switched on so that the rotational speeds of the two rolling mills can adapt to each other. The rolling mill A is advantageous with relatively large roller diameter reversible set up, and advantageous with simultaneous deactivation of the rolling mill B with a relatively small roll diameter, thus the rolling mill with a large roll diameter at the beginning of the rolling process. with alternating direction of rotation can be operated, so that the beginning of the rolling stock gradually through the rolling mill A to the later through the rolling mill B with small Roll diameter achievable strength is rolled down.

One proceeds z. B. in the following way. You first open the nip of the rolling mill B so far that the rolling stock can be pushed through. Then a short piece of the rolling stock is rolled with the rolling mill A, as thin as possible in several passes, until the thickness that is later to be achieved by the rolling mill B is reached. The rolling stock is then rolled or pulled back so far that the thinner rolled rolling stock is between the rollers B, and then the roller gap of the rolling mill B is set to this thickness. The rolling mill A then rolls the rolling stock even thinner and pulls it through it at the same time relatively thin work rolls in this rolling mill, the same cross-sectional decrease of the rolling stock is achieved in one pass that was previously achieved by several passes.

Various advantages are achieved with this method.

i. The rolling stock is rolled out without waste.

a. The rolling stock leaving the rolling mill A is completely smooth. the Specifically highly stressed thin rollers B are very easily rough or damaged, but the defects then marked on the rolling stock are caused by the rolling mill A eliminated.

3. There is no pre-treatment of the rolling stock by sharpening it on others Required by machine or by hand.

4. There can be the advantages of rolling with thin work rolls consist in that relatively large decreases with relatively small Power consumption can be achieved with thicker rolling stock than has previously been the case relatively less space-consuming rolling mills are achieved: 5. The for the drawing through the rolling mill with thin work rolls required large Tensile force is generated without additional tools.

The rolling work done by rolling mill B with thin work rolls can also be increased by also driving the rollers. This drive is expediently made elastic, so that the rolling speed of the small The rolling mill is adapted to that of the large rolling mill.

Of course, the rolling mill A can also pull the rolling stock at the same time by several rolling mills arranged one behind the other with a smaller roller diameter be pulled through. Compared to the previously known rolling mills, which one behind the other arranged but all driven (continuous roads) results The new method has the advantage that the occurring in continuous roads structural difficulties, the rolling speed of each rolling mill of each respective Adapt the cross-section reduction to the corresponding rolling stock speed, not appear.

If necessary, in addition to the rolling mill A with rolls of large diameter arranged behind the rolling mill B , such a mill could also be arranged in front of the rolling mill B. If both rolling mills with large roll diameters are reversible, the rolling stock can be rolled down in several consecutive passes by switching over these rolling mills, namely in alternating working directions.

Claims (3)

PATENT CLAIMS: i. Rolling mill for metal sheets, strips and bars, in which the rolling stock is pulled through work rolls of relatively small diameter, characterized by one or more of the tensile force for. the rolling mills (A) producing the rolling stock with a relatively large diameter, the actual work rolling mill (s) (B) either being designed without a drive or provided with an additional auxiliary drive, preferably with an elastic design of this drive. 2. Rolling mill according to claim i, characterized in that that the rolling mill (A) is set up reversible with a large roller diameter. 3. Rolling mill according to claim i and 2, characterized in that the pulling rolling mill (A) is set up controllable in such a way that it is switched off at the beginning of the rolling process the actual work rolling mill (B) is operated with alternating direction of rotation, so that the beginning of the rolling stock gradually passes through the drawing mill (A) to the later the thickness achievable by the work rolling mill (B) is rolled down.