JP3194260B2 - Chatter mark prevention device in temper rolling mill - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for preventing chatter marks in a cold pass mill.

[0002]

2. Description of the Related Art Generally, in a cold rolling mill, a kind of resonance phenomenon called a chattering phenomenon may occur between a steel plate to be rolled and a rolling mill. This chattering phenomenon is a serious impeding factor in operation, and when this chattering phenomenon occurs, a horizontal stripe pattern called chatter mark appears on the surface of the steel sheet after rolling, which significantly impairs the product quality, and in some cases, the sheet breaks. You can even reach it.

There are various possible causes of chattering, and countermeasures have been proposed for each cause.

For example, in Japanese Patent Application Laid-Open No. 62-292209, as one of the causes of chattering, the position of the neutral point is affected, and when the neutral point is behind the roll bite (when the advance rate is negative), If so, chattering is prevented by controlling the tension between stands so that the advance rate becomes positive.

In Japanese Patent Publication No. 3-50602, a vibration detector is installed in the housing of a rolling mill to detect vibrations assuming that the vibrations are caused by the mills. When a value is exceeded, a control signal is output to reduce the rolling speed of the mill, change the coolant flow rate, and control rolling conditions to prevent chattering.

[0006] Alternatively, in Japanese Patent Publication No. 54-23861,
Chattering is prevented by using an extreme pressure agent to which a dialkyldithiophosphate-based extreme pressure agent containing an organic metal Zn is added.

In Japanese Patent Publication No. Sho 61-16522, chattering is prevented by setting the working roll diameter of the cold rolling mill and the unit tension of the steel sheet on the delivery side to specific ranges.

[0008]

However, chattering may occur even if the above-mentioned countermeasures are taken. For example, in Japanese Patent Publication No. 3-50602,
There was a problem that only chattering related to the sheet breaking could be controlled, and a slight one could not be handled.

After all, the conventional method focuses on how early chattering is detected, and most prevention methods control rolling conditions after chattering is detected. .

That is, both techniques of the chattering detecting device and the rolling control at the time of chattering are required. There's a problem.

Therefore, it is apparent that it is desirable to improve the apparatus so that chattering does not originally occur, instead of controlling after detecting chattering.

The present invention has been made to solve the above-mentioned conventional problems, and has as its object to provide an apparatus for preventing chatter marks in a temper rolling mill which can effectively suppress even small chatter marks. And

[0013]

SUMMARY OF THE INVENTION The present invention is characterized in that a plate surface vibration suppressing roll and a pressing force adjusting device therefor are arranged near an upstream side of an auxiliary roll of a cold strip rolling mill for metal strip. The purpose has been achieved.

The present invention also achieves the above object by using the auxiliary roll as a tension measuring roll.

The present invention also achieves the above object by providing a plate vibration measuring device upstream of the plate vibration suppressing roll.

The present invention further provides the above-mentioned plate surface vibration measuring device,
The above-mentioned object is also achieved by using a non-contact displacement gauge which is mechanically isolated from the rolling mill and peripheral equipment.

[0017]

According to the investigation and research by the present inventors, in the temper rolling mill, the steel plate slips due to the drive vibration of the bridle roll, and the plate vibrates in the longitudinal direction. It is considered that the inflection point 6 of the metal strip 1 fluctuates back and forth between the tension measuring roll 2 and the deflector roll 4 as shown in FIG. 1, thereby causing residual distortion in the plate and generating chatter marks. Can be

Therefore, according to the present invention, in order to prevent chatter marks, near the upstream side of the auxiliary roll of the temper rolling mill (for example, in FIG. 1, upstream of the tension measuring roll 2).
In addition, by adding a plate surface vibration suppressing roll and a pressing force adjusting device thereof and performing fine adjustment, chattering can be suppressed, and as a result, chatter marks on the plate surface can be prevented.

The auxiliary roll may be a tension measuring roll.

Further, by providing a plate surface vibration measuring device upstream of the plate surface vibration suppressing roll and monitoring the chattering of the plate itself, unlike the conventional method, there is no possibility of erroneous detection and the chatter mark is completely removed. Can be prevented from occurring.

[0021]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 2 is a side view schematically showing a line of the present embodiment to which the present invention is applied.

In FIG. 2, 2 is a tension measuring roll, 4 is a deflector roll, 8 is a plate surface vibration suppressing roll, 10 is a pressing force adjusting device, and 12 is a skin pass mill including a work roll (12a) and a backup roll (12b). , 1
4 is an anti-cross brake roll, 16 is an anti-clipping roll, 18 is a tension bridle roll, 20
Is a displacement meter, and 22 is a control device. The tension bridle roll 18 is a roll used to apply tension to the steel plate, and the deflector roll 4 is for giving an angle to the plate in the tension measurement roll 2, and includes the anti-clipping roll 16 and the anti-cross brake roll 1.
Reference numeral 4 denotes an auxiliary roll for controlling the plate surface shape.

The steel plate is a tension bridle roll 1
8. Rolled by the skin pass mill 12 via the tension measuring roll 2, the deflector roll 4, and the anti-clipping roll 16, and proceed to the next step via the anti-cross brake roll 14.

As shown in FIG. 2, a plate surface vibration suppressing roll 8, a pressing force adjusting device 10, and a displacement gauge 20 are provided upstream of the tension measuring roll 2. The displacement meter 20 measures the vibration of the plate surface itself, and is preferably provided on a stand separate from the rolling mill and peripheral equipment, and is preferably of a non-contact type. Is optimal.

The control device 22 controls the pressing force adjusting device 10 based on the output of the displacement meter 20.

When the temper rolling is performed, only the chattering of the plate itself is monitored by the displacement gauge 20 and the plate surface vibration suppressing roll 8 is finely adjusted by the pressing force adjusting device 10 to suppress the chattering. Prevent chatter marks.

The chatter mark is such a minute product defect that it cannot be found without a skilled operator. FIG. 3 shows a line before application of the present invention (before the plate surface vibration suppressing roll is installed).
A state of plate surface vibration by a line to which the present invention is applied is shown for comparison. As can be seen from the graph of FIG. 3, the amplitude of the plate surface vibration was reduced after the implementation of the present invention, and as a result, the chatter mark was no longer a quality problem.

As a modified example of this embodiment, when the tension measuring roll 2 is not provided, or as shown in FIG. The vibration suppressing roll 8 may be provided.

It should be noted that the embodiments of the present invention are not limited to those described above, and it is apparent that various other modifications are possible.

[0031]

As described above, according to the present invention,
By installing a plate surface vibration suppression roll adjacent to the entrance side of the temper rolling mill to suppress plate surface vibration, there is no risk of erroneous detection as in the past, and a mild This has an excellent effect that the chatter mark can be completely prevented even for objects.

[Brief description of the drawings]

FIG. 1 is a side view showing a part of a rolling mill for explaining the cause of chattering.

FIG. 2 is a side view of the temper rolling line after application of the present invention.

FIG. 3 is a graph for comparing the state of plate surface vibration before and after application of the present invention.

FIG. 4 is a side view of a line showing a modification of the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Strip 2 ... Tension measuring roll 4 ... Deflector roll 6 ... Inflection point 8 ... Plate surface vibration suppression roll 10 ... Pressing force adjustment device 12 ... Skin pass mill 14 ... Anti-cross brake roll 16 ... Anti-clipping roll 18 ... Tension bridle Roll 20: Displacement gauge 22: Control device

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-57-100818 (JP, A) JP-A-4-4913 (JP, A) JP-A-62-292209 (JP, A) JP-A-7-107 12638 (JP, A) JP-A-7-2399 (JP, A) JP-B 3-50602 (JP, B2) JP-B 54-23861 (JP, B2) JP-B 61-16522 (JP, B2) (58) Field surveyed (Int. Cl. ⁷ , DB name) B21B 33/00 B21B 39/08

Claims (4)

(57) [Claims] 1. A chatter in a temper rolling mill, wherein a sheet surface vibration suppressing roll and a pressing force adjusting device therefor are arranged near an upstream side of an auxiliary roll of a cold strip rolling mill for metal strip. Mark prevention device. 2. A chatter mark preventing device in a temper rolling mill according to claim 1, wherein said auxiliary roll is a tension measuring roll. 3. A chatter mark preventing device in a temper rolling mill according to claim 1, wherein a sheet surface vibration measuring device is provided upstream of said sheet surface vibration suppressing roll. 4. A chatter mark prevention in a temper rolling mill according to claim 3, wherein said plate surface vibration measuring device is a non-contact displacement meter mechanically separated from the rolling mill and peripheral equipment. apparatus.