JPH04123805A - Method and device for preventing sticking foreign matter to surface of roll - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a method and device for preventing the adhesion of foreign matter on the surface of a roll, and in particular, in rolling mills such as cold rolling mills and temper rolling mills, The present invention relates to a method and device for preventing foreign matter from adhering to a roll surface to maintain quality.

[Conventional technology]

In a cold strip rolling mill (cold strip mill), rolling oil (roll coolant), which also serves as lubrication and roll cooling for rolling, is used at a rate of 500 (1-1000011) per stand.
/min, and Cono coolant is supplied at about 50 to 100
Generally, it is returned to a m3 tank and recycled for use.

By the way, abrasion powder of the rolled material and rolls is generated during rolling, and when this abrasion powder adheres to the surface of the work roll, it causes flaws on the surface of the plate, resulting in defective products. In other words, when foreign matter adhering to the surface of the work roll is pressed against the reinforcing hole or the intermediate roll, it creates a dent on the surface of the work roll, and the dent is transferred to the surface of the plate rolled by the roll. Scratches occur on board products. One way to prevent this is to lower the hardness of the reinforcing roll to absorb the deformation caused by foreign objects and reduce damage to the work roll, but this has the problem of shortening the life of the reinforcing roll, and the basic It's not a solution.

This foreign substance is thought to be of the following two types.

(1) Abrasion powder of work rolls It's especially intense when using Dull Roll.

(2) Foreign matter generated from rolled materials These can be divided into abrasion powder from rolling and metal chips torn off from plate edges, etc.

Conventionally, it was common practice to mix all of these foreign substances into a large amount of coolant and remove them with a filter. For this reason, large and expensive filters have traditionally been used, but in the case of tallow-based rolling oil, which has good lubricity and excellent rolling properties, using a fine-mesh filter can separate the oil and water. , problems such as clogging and damage to the filter occur. There is also a method of removing iron powder using a magnet in the filter, but the iron powder in the rolling oil may be contaminated with beef tallow, etc.
Being integrated with important components, removing iron powder comes at the cost of losing valuable oils and fats.

[Problem to be solved by the invention]

As described above, the conventional technology removes generated foreign matter by mixing it into the coolant, but it requires the use of large and expensive filters, and there is a problem that the filters may become clogged and damaged. Moreover, when magnets are used, there is a problem in that expensive rolling oil is lost.

How to respond to the increasingly sophisticated surface quality of steel plate products is an extremely important issue.

Currently, although automatic inspection equipment for plate surface defects is being developed, it has not reached the level of practical use, and rolling speeds are kept extremely low and human visual inspection is relied upon. It is not uncommon for cases where this occurs.

An object of the present invention is to provide a method and apparatus for preventing foreign matter from adhering to a roll surface, which can maintain high surface quality of rolled products by effectively removing foreign matter.

[Means to solve the problem]

In order to achieve the above object, the method of the present invention keeps a magnet close to the roll surface of a rolling mill, and keeps the roll surface clean by attracting metal powder on the roll surface to the magnet by magnetic force.

Further, in the method of the present invention, preferably, a magnet is further brought close to the surface of the rolled material on the exit side of the rolling mill, and foreign matter on the surface of the plate is attracted to the magnet by magnetic force.

Moreover, in order to achieve the above object, the apparatus of the present invention is one in which a magnet is installed close to the roll surface of a rolling mill to attract metal powder on the roll surface.

Preferably, the apparatus of the present invention further includes a magnet close to the surface of the rolled material on the outlet side of the rolling mill for attracting foreign matter on the surface of the plate.

[Effect]

By placing a magnet close to the roll surface of a rolling mill and using its magnetic force to attract the metal powder on the roll surface, the metal powder is transferred to the work roll by the reinforcing roll immediately before it is mixed into the coolant and immediately after foreign matter is generated. removed before being crimped. This prevents the inefficiency of removing foreign matter from a large amount of coolant with a filter, and when removing foreign matter mixed in coolant, no matter how thorough filtration is, Foreign matter that was not removed and was causing harm to the surface of the work roll is also prevented, and the surface quality of the rolled product can be maintained at a high level.

Furthermore, by arranging a magnet close to the surface of the rolled material on the exit side of the rolling mill and using its magnetic force to suck up foreign matter on the plate surface, foreign matter adhering to the surface of the rolled material can be mixed into the coolant. This reduces the burden on the filter due to foreign matter entering the coolant.

〔Example〕

An embodiment of the present invention will be described with reference to FIG.

In FIG. 1, reference numeral 1 denotes work rolls of a rolling mill, each of which is supported by reinforcing rolls 2. Coolant 4 is injected from an injection nozzle 3 onto the work rolls to provide lubrication for rolling and to cool the rolls 1.2. 5 is a rolled steel plate. A magnet 6 is installed close to the surface of the work roll, and attracts metal powder, ie, foreign matter 7, on the surface of the roll. A recess 6A for collecting foreign matter is formed in a portion of the magnet 6 facing the roll surface.

Next, the operation of this embodiment will be explained. First, the harmful behavior of conventional foreign objects will be explained with reference to FIG. Abrasion powder and chips generated during rolling, that is, foreign matter 7, are removed from the work roll.
or the surface of the rolled steel plate 5. Foreign matter on the steel plate is removed in a cleaning line etc. after rolling, so it does not directly damage the quality, but the foreign matter 7 on the work roll surface is crushed at the contact point A with the reinforcing roll 2, and as a result, A dent 8 is generated on the work roll at the same time as the reinforcing roll 2. Therefore, when rolling a steel plate on this plane,
Mark No. 9 appears on the surface of the steel plate 5, resulting in a defective product in terms of surface quality.

In contrast, in this embodiment, before the foreign matter 7 is pressed by the reinforcing roll 2, it is separated from the work roll 1 by the magnetic force of the magnet 6 and is attracted to the magnet 6. As a result, the above-mentioned dents 8 are prevented from occurring on the surface of the work roll, and transfer marks 9 are not generated on the surface of the steel plate 5, so that a product with good surface and quality can be obtained.

Also, since foreign matter 7 is prevented from entering the coolant,
Foreign matter entering the coolant is also significantly reduced, reducing the burden on the filter that filters the coolant.

Another embodiment of the present invention will be described with reference to FIG.

In the embodiment shown in FIG. 1, the foreign matter 7 attached to the roll surface is removed by the magnet 6, but the foreign matter attached to the surface of the rolled steel plate 5 is not removed, so it falls during the movement and gets mixed into the coolant. there's a possibility that. This embodiment also prevents this foreign matter from entering.

In FIG. 3, downstream of a rolling mill consisting of a work roll 1 and a reinforcing roll 2, a work roll ``a'' and a reinforcing roll 2a are shown.
Another rolling mill consisting of is arranged, and a magnet 6a is also arranged close to the work roll 1a of this rolling mill. The rolled steel plate 5 is placed on the exit side of the upstream rolling mill, that is, between the two rolling mills
Upper and lower magnets 10 are placed close to the upper and lower surfaces of the plate to attract foreign matter 11 on the plate surface. The magnet 10 also has a concave portion 10A for collecting foreign matter formed in a portion facing the plate surface.

According to this embodiment, since the foreign matter 11 attached to the rolled steel plate 5 can also be removed, the amount of foreign matter mixed into the coolant is further reduced, and the burden on the filter for removing foreign matter from the coolant is further reduced.

In addition, if foreign matter attached to the rolled steel plate 5 is not removed, when the rolled steel plate is rolled in the downstream rolling mill, the second
The behavior similar to that explained in the figure causes scratches on the roll surface and deteriorates the surface quality of the steel plate, but according to this example, the foreign matter 11 is removed from the surface of the steel plate, so the downstream rolling mill It is also possible to roll steel plates with good surface quality.

FIG. 4 shows the detailed structure of the magnet 6 portion. The magnet 6 is given a function that can be turned on and off. This may be realized using the principle of a magnetic stand, or may be configured to be switched using an electromagnet. A passage 13 is provided on one side of the magnet 6 for supplying a fluid 12 such as water, rolling oil, or air to the recess 6A of the magnet, and on the other side of the magnet 6, a passage 13 is provided for supplying a fluid 12 such as water, rolling oil, or air to the recess 6A of the magnet, and on the other side of the magnet 6 there is provided a passage 13 for supplying a fluid 12 such as water, rolling oil, or air to the recess 6A of the magnet. A collection device is installed. A mesh filter 16 is installed at the bottom of the foreign matter storage box 15.
is provided.

Further, at both ends of the magnet 6, contacts, such as balls 17, which are in contact with the roll surface and maintain a predetermined gap therebetween, are arranged.

After the foreign matter is collected by the magnet 6, the fluid 12 is ejected from the passage 13 into the recess 6A, and the attracted foreign matter 7 is discharged into the foreign matter storage box 15 by the deflection plate 14.

At this time, preferably the magnetic force of the magnet 6 is turned off to facilitate the discharge of the foreign matter 7. The fluid discharged into the foreign matter storage box 15 passes through the filter 16, and only the foreign matter is captured by the filter 16. Thereby, the foreign matter 7 is collected so as not to mix into the coolant.

Furthermore, in order to make the magnetic force work effectively, it is desirable that the distance between the roll surface and the magnet 6 be close enough to avoid contact. Also,
The magnet 6 must be movable in the rolling direction in order to change the roll diameter or replace the roll. In this embodiment, since contacts made of balls 17 are installed at both ends of the magnet 6, the gap between the roll surface and the magnet 6 can be maintained at an optimum value, and even when the magnet 6 is moved, the gap between the roll surface and the magnet 6 can be maintained at the optimum value. can be easily reset.

The magnet 10 is also constructed similarly to the magnet 6.

The above embodiments apply the present invention to work rolls of a rolling mill, but the present invention can also be applied to other rolling mill rolls and rollers other than rolling mills, such as deflection rollers, bridle rollers, and roller levelers. It can also be applied to rollers, etc.

〔Effect of the invention〕

According to the present invention, foreign substances that cause surface defects on rolled steel sheets are removed immediately after they occur and before they cause damage to the product, so the surface quality of the product can always be maintained at a stable and high level. Productivity can be significantly improved.

Further, by applying the present invention, the contamination of foreign matter into rolling oil is significantly reduced, the use of large and expensive filters becomes unnecessary, and losses of rolling oil are also reduced.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a rolling mill equipped with a foreign matter adhesion prevention device according to an embodiment of the present invention, FIG. 2 is a diagram showing the behavior of foreign matter when the present invention is not implemented, and FIG. FIG. 4 is a schematic view of a rolling mill equipped with a foreign matter adhesion prevention device according to another embodiment of the present invention, and FIG. 4 is a detailed view of the foreign matter adhesion prevention device. Explanation of symbols 1.1a...Work roll 2.2a...Reinforcement roll 5...Rolled steel plate 6.10...Magnet 12...Fluid 13...Passage 14...Deflection plate (collection Device) 15...Foreign object storage box (same) 17...Ball (contact)

Claims (10)

[Claims] (1) A method for preventing foreign matter from adhering to a roll surface, which comprises bringing a magnet close to the roll surface of a rolling mill and keeping the roll surface clean by magnetically attracting metal powder on the roll surface to the magnet. (2) The method for preventing foreign matter from adhering to the roll surface according to claim 1, characterized in that the magnetic force of the magnet can be turned on and off, and the magnetic force of the magnet is turned off to jet a fluid to remove foreign matter attracted to the magnet. Method. (3) The method for preventing foreign matter from adhering to the roll surface according to claim 2, characterized by storing the removed foreign matter in a recovery device so as not to mix it into the roll coolant. (4) The method for preventing foreign matter from adhering to the roll surface according to claim 1, further comprising: bringing a magnet close to the surface of the rolled material on the exit side of the rolling mill, and attracting foreign matter on the plate surface to the magnet by magnetic force. How to do it. (5) The method for preventing foreign matter from adhering to the roll surface according to claim 1, characterized in that contacts are provided at both ends of the magnet, and the gap between the two is maintained at an optimum value through contact between the contacts and the roll surface. Method. (6) A device for preventing foreign matter from adhering to a roll surface, characterized in that a magnet is installed close to the roll surface of a rolling mill to attract metal powder on the roll surface. (7) The apparatus for preventing foreign matter from adhering to the roll surface according to claim 6, further comprising a fluid passage for removing foreign matter attracted to the magnet. (8) The device for preventing foreign matter from adhering to the roll surface according to claim 7, further comprising a recovery device for storing the foreign matter removed by the fluid passage so as not to mix it into the roll coolant. (9) In the apparatus for preventing foreign matter from adhering to the roll surface according to claim 6, a magnet is further installed close to the surface of the rolled material on the exit side of the rolling mill to attract foreign matter on the plate surface. Featured device. (10) The device for preventing foreign matter from adhering to the roll surface according to claim 6, characterized in that contacts are provided at both ends of the magnet to contact the roll surface and maintain the gap between the roll surface and the magnet at an optimum value. Device.