JPS6284817A - Back tension device for scale breaker - Google Patents

Abstract

PURPOSE:To enable the effective breaking or leveling by giving an optomum tension without causing any press flaw on a trip by pinching the strip between the plural rolls which are arranged in zigzag and by giving it a bend forcibly. CONSTITUTION:The strip 11 having passed through an annealing furnace 1, fog cooling tank 2 and water quench 3 is passed to the acid cleaning pre-treating equipment composed of the scale breaker 4 which is quipped with a bending roll unit 8 and leveling unit 9, the bridle 6 which controls the speed of a drier 5 and the line, etc. In said scale breaker 4, the tension of the strip 11 is held properly by a back tension device 7. Said device 7 is made by arranging the upper roll 13 with rubber lining and lower roll 14 coated with ceramics in zigzags, holding the strip 11 between said plural roll 13, 14 by a hydraulic cylinder 10 and giving a forced bend.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an improvement of a back tension device used in a device for descaling and shape correction in pre-pickling treatment of common steel and special steel.

(Conventional technology) An oxide film is usually formed on the surface of the steel strip after hot rolling, and in the case of special steel, it is hardened, so in order to carry out the next process of cold rolling, it is softened. The bell of dawn and the oxide film (hereinafter referred to as scale) on the surface are being removed. This scale is hard and brittle, so conventionally, to remove this scale, a steel ball is shot onto the surface of the steel plate using show blasting to crack the scale on the surface of the steel plate, and then sulfuric acid and Chemical removal methods using chemicals such as nitric acid, hydrochloric acid, and fluoroboric acid were used.

However, in recent years, users' requirements for the surface of steel sheets have become stricter, and when shot blasting is used on the surface of steel sheets, dents remain, so cracks are created in the scale by reducing the shot grain size and using bending rolls. This shortens the pickling time.

Since this bending requires applying high tension to the steel plate, pinch rolls are provided on the entry side.

This type of conventional pickling pretreatment equipment is summarized in Section 4.
As shown in the figure, a fog cooling tank 2 and a water quench 3 are arranged at the rear of the annealing furnace 1, and a scale breaker 4 is arranged on the outlet side thereof. 5, and a prydle 6 for controlling the speed of the line is further disposed behind it. And the scale breaker 4 is
It consists of a pinch roller 7a that applies back tension to the steel plate on its entry side, three bending rolls located in the center, and a leveling roll unit 9 on its exit side.

To explain the scale breaker 4 in more detail, the pinch roll 7
A is generally lined with rubber, and the strip 11 is held by a hydraulic cylinder lO, and a drag operation is performed by a DC motor (not shown) to apply tension e to the strip 11. Further, the bending roll unit 8 has 72 pairs of backup rolls and a lower pair of backup rolls, and the rolling reduction jJY can be set by an electric motor (not shown) according to the thickness of the sheet. moreover,
The leveling roll unit 9 is installed to correct the bending caused by the sudden bending of the plate by the bending roll unit 8, and the reduction amount can be set according to the thickness of the plate using an electric motor (not shown). .

In addition, these bending roll units 8 and leveling roll units 9 are all non-driven, and the plate bending resistance due to these rolls appears as an increase in the tension of the strip 11, and this tension can be pulled by the rear priddle 6. It is now possible to do so.

In addition, a water cooling nozzle (not shown) is installed in the scale breaker 4 to spray water onto the strip 11 from the inlet to the outlet in order to prevent indentation damage caused by the scale being pulled up.

(Problem to be solved by the invention) The above-mentioned equipment has the following drawbacks.

l) The strip 11 heated in the annealing furnace 1 is rapidly cooled by cooling water and enters the pinch roll 7a (or priddle roll) in a wet state, so if a large tension is to be applied, the roll and the strip 11 A slip occurs between the strips and the strip, making control difficult. At the same time, the curvature of the strip by the bending roll unit 8 also changes, making it difficult to perform uniform braking or leveling.

2) When applying a large capacity reduction edge to the strip 11 using the pinch rolls 7a, the rolls must be made of steel, which results in the production of scrapes in the product.

3) If the surface of the pinch roll 7a is rubber-lined, slipping occurs between the roll and the strip 11 as described in 1), causing uneven wear of the roll, and the life of the roll is shortened. becomes extremely short. Further, if a prydle roll is used instead of the pinch roll 7a, the roll diameter becomes large and equipment consumption increases.

4) When the surface of the pinch roll 7a (or the priddle roll is rubber-lined), when the part where strips of different thicknesses are joined passes, the upper roll is used as an oven, but the subsequent strip 11 is not cooled. If the temperature is high due to immo content, there is a risk that the rolls will be burnt out, making stable operation difficult.

In view of the above problems, the present invention enables more effective braking or leveling by applying tension to the strip within the bending roll or leveling roll, and enables stable operation at all times even when the strip is wet. The purpose of the present invention is to provide a back tension device for a scale breaker that can be used.

<F stage for solving the problem> The structure of the present invention for achieving the above object is provided on the entrance side of the bending roll of a scale breaker having a bending roll and a leveling roll, and is installed in the bending roll or the leveling roll. A back tensioning device for a scale breaker that applies tension to a strip is characterized by comprising a plurality of rolls arranged in a staggered manner with the strip sandwiched between the strips and forcing the strip to bend. Features: By forcibly bending the strip using a plurality of rolls arranged in a staggered manner, mechanical loss (energy) called bend loss is generated, and this mechanical loss generates back tension in the strip. This energy is different from a pinch roll that uses a rolling blade and friction, and a strip! ! Generates tension regardless of type.

<Embodiment> Hereinafter, a preferred embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram of a pickling pretreatment facility using a back tension device according to this embodiment, and FIG. 2 is an explanatory diagram showing the configuration of the back tension device according to this embodiment. Note that the same parts as those described in the prior art are denoted by the same reference numerals, and redundant explanation will be omitted.

As shown in both figures, the back tension device 7 provided on the inlet side of the scale breaker 4 is of a three-roll type, with an upper roll 13 and two trolls 14 on the right side. ”The second roll 13 has a rubber lining 1 on its outer circumference.
2, and is rotatably held via a bearing 15 in a bearing box 18 that can be raised and lowered. 30. On the other hand, two lower rolls 1 are arranged horizontally.
4 has a surface coated with ceramic, and the bearing 1 is mounted in a bearing box 17 fixed to the frame 21.
It is rotatably held via 6. These L roll 13 and lower roll 14 are rotationally driven separately, and the J
: Role 13 is a universal join)22. ilt
Direct current motor 2B via speed gear 24 and coupling 25
The two wooden five rolls 14 are driven by two universal joints 23 and a distribution reducer 27. It is driven by a DC motor 28 via a coupling 28.

In such a configuration, the upper roll 13 is connected to the cylinder 20
By driving the upper roll 13 and the two trawls I4 while pressing the strip 11 downward, the strip 11 is bent and clamped to obtain back tension. In this case, 2mm to 6ml! If a hydraulic cylinder 20 is used that can bend the strip 11 up to 1, the bending resistance will be 2000 kg to 80 kg in terms of tension.
It reaches 00 kg. This value can be freely changed depending on the roll arrangement and roll diameter. The above-described embodiment has a simple structure and is designed to provide both the bending effect and the pinch roll effect so that the maximum effect can be obtained. Moreover, the pinch roll effect is equivalent to two pinch rolls.

In the embodiment described in L, in order to further improve the pinch roll effect, the friction coefficient in the water-tangled state is increased by IIJJ,
And to prevent the occurrence of push-in scratches.

A ceramic coating was applied to the lower roll 14, and a rubber lining 12 was applied only to the 1st roll 13. At this time, the tension generated in the lower roll is NXpXbXM=0.0 when the strip is 1m wide. IX 80X 1
00
100 X2 = 600kg, total r8QO
You can expect a pinch roll effect of kg.

If the tension due to the above-mentioned bending effect is added to the tension due to the pinch roll effect of 1800 kg, the result is 3800 kg to 9800 kg. As described above, according to Example 1, a back tension of 3800 kg can be obtained even with a thin material, which is a sufficient value for use in this type of scale breaker.

For comparison, let us estimate the hex tension using the pinch roll method according to the prior art. For pinch rolls with rubber lining, the maximum linear pressure is currently considered to be 50 to 90 kg/car due to the strength of the rubber, so if the strip is 1 m wide, the tension is N.
X p X b = 0.05X 90X 100; 4
50kg, 900 even if the upper and lower rolls are driven
kgJ'ti degrees. Therefore, according to the conventional method, 3 to 4
It is necessary to arrange the pinch rolls on the stand in tandem.

FIG. 3 shows back tension 'A' according to another embodiment.
40 is shown. In this back tension device 40,
The upper and lower rolls 32 of the 3-wooden wood are each provided with two 8-up rolls 31, so the upper and lower rolls 3
2 can be made smaller in diameter.

As explained above, according to the back tension device of this embodiment, it is possible to obtain the effect of three to four conventional pinch rolls. Moreover, since the rolls are arranged in a staggered manner, the reduction blade is 30% to 40% larger than that under direct pressure such as a pinch roll, so the hydraulic cylinder for reduction is relatively small. be able to.

In addition, such a back tension device.

In addition to scale breakers, it is also useful for tension levelers, levelers, etc.

<Effects of the Invention> As described above in detail with the examples, by using the back tension device according to the present invention, it is possible to effectively apply a large back tension to the strip by the bending effect and the pinch roll effect. Moreover, since no slip occurs between the roll and the strip, control is easy, and the curve -V of the split by the bending roll unit does not change, making uniform braking or leveling easy. In addition, since a large back tension can be obtained with a small rolling blade, the strip will not be scratched, and since it will not slip, uneven wear of the roll will not occur and the life of the roll will be extended. Further, since there is no need to provide a rubber lining to the lower roll, if the upper roll is opened when the strip joint passes, the roll will not be burnt out even if the following strip is at a high temperature.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a pickling pretreatment facility equipped with a back tension device according to an embodiment of the present invention, FIG. 2 is an explanatory diagram showing the configuration of the back tension device, and FIG. 3 is an illustration of another embodiment. FIG. 4, an explanatory diagram showing the configuration of the back tension device according to the example, is a schematic diagram of the pickling pretreatment equipment according to the prior art. Inside the drawing. 4 is a scale breaker, 7 is a back tension device. 8 is a bending roll unit, 9 is a leveling roll unit. 11 is a strip, 13 is an upper roll, 14 is a lower roll, and 40 is a back tension device.

Claims (1)

[Claims] In a scale breaker back tension device that is installed on the inlet side of the bending roll of a scale breaker having a bending roll and a leveling roll and applies tension to the strip in the bending roll or the leveling roll, the back tension device holds the strip and applies tension to the strip. A back tension device for a scale breaker, characterized by comprising a plurality of rolls arranged in a staggered manner with strips that provide forced bending in between.