JPH0368719A - Method and apparatus for preventing meandering of steel strip - Google Patents

Abstract

PURPOSE:To efficiently prevent meandering of a steel strip by partially arranging porous part at center part in strip width direction of a roll and in peripheral direction of barrel part and attracting the steel strip from this porous part. CONSTITUTION:The porous part 5 is set at a part or plural positions in the peripheral direction and at the center part in roll width direction in the range of not exceeding the min. steel strip width in the roll body 6, and suction space 7 in inner part of the roll is sucked with a vacuum suction device 10 through air suction passage 8 and rotary joint 9 communicated with the outer part to make negative pressure, and the steel strip 4 is attracted to the roll 6. Further, in order to hold the negative pressure in inner part of the roll during rotating, the rotary synchronous joint 11 is arranged at end of the roll so as to communicate the suction space part 7 with the air suction passage 8 only at the moment of contacting with the steel strip 4 and porous part 5. By this method, the effective preventing apparatus for meandering to the whole size of the steel strip from thick to thin material and from wide to narrow material, is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a method and apparatus for preventing meandering of a cold rolled steel strip.

(Prior Art) Conventionally, as a method for preventing meandering of a cold rolled steel strip, there is a method employing a tapered crown roll and a steering device.

As shown in Fig. 5, the tapered crown roll consists of a parallel part 2 in the center and tapered parts 1 on both sides, and if some disturbance is applied to the steel strip passed through this and meandering occurs, This is also a meandering prevention method in which a centering force is applied to return the sheet to the center, contributing to returning the sheet to its normal threading state.

The steering device is a roll position correction device consisting of a sheet passing position detection sensor, a hydraulic system, etc., and changes the roll angle or position to return the steel strip in the opposite direction according to the meandering of the steel strip, thereby preventing meandering. This is what we aim to do.

In addition, in Japanese Patent Application Laid-open No. 80-21332, as shown in Fig. 6, distributed openings are formed around the circumference of the tapered roll excluding the central part, on both sides of the roll, which exceeds the maximum sheet width to be threaded. A method of preventing meandering particularly in a continuous annealing furnace is proposed by providing a large number of suction holes 3 for atmospheric gas and bringing the steel strip 4 into close contact with each other to improve its restraint.

(Problem to be solved by the invention) Regarding tapered crown rolls, the greater the thickness of the steel strip, the greater the centering effect, but when thin material is passed through, the effect becomes smaller, and line speed reduction is avoided to prevent meandering. I can't.

As a countermeasure to this problem, increasing the taper angle may be considered, but wrinkles frequently occur in the steel strip. Particularly in continuous annealing lines, wrinkles called heat buckles are a problem.

Therefore, there is a limit to the centering force of the tapered roll, which poses a bottleneck to either process capacity or product quality.

Next, since the method using a steering device employs a sensor and a hydraulic system, it has a problem of having a complicated mechanism in terms of electrical equipment and mechanical equipment, resulting in high equipment costs.

Furthermore, in the method proposed in Japanese Patent Application Laid-open No. 80-21332, when a narrow material is passed through, the contact area between the suction hole and the steel plate becomes smaller, and the adhesion force becomes weaker, so the effect becomes smaller. When this roll is used, since it is not tapered, it is impossible to correct a meandering steel plate, even if it is a narrow material, even if it is brought into close contact with the suction holes located at both ends. Furthermore, since there are parts where the steel plate and the suction holes do not come into contact, it is difficult to maintain the degree of vacuum inside the roll, which requires a large amount of vacuum suction power, which poses a running cost problem.

(Means for Solving the Problems) In view of the above-mentioned problems, the present invention provides a method for preventing meandering in a high-speed line using rolls that have a large restraining force for the entire threaded size and can efficiently vacuum suction. A method and apparatus are provided.

The gist of the present invention is to provide a porous part in the central part in the width direction of the roll and partially in the circumferential direction of the roll, and to apply suction from the porous part to prevent meandering, and the width of the roll. A porous part is provided in the center of the direction and partially in the circumferential direction of the body, a suction space is provided inside the roll of the porous part, and the suction space and a vacuum suction device are connected to each other for suction through a rotary joint. This is a meandering prevention device for a steel strip, which includes a rotation synchronized joint that is connected to the steel strip through a passage and that a suction passage opens when the steel strip and a porous portion come into contact within the rotary joint.

In other words, a roll used for passing a cold-rolled steel strip is provided with a porous portion at a part or multiple locations in the roll circumferential direction at the center in the strip width direction within a range not exceeding the minimum strip width, and the rotation of the roll is By applying suction from the outside through the joint, a negative pressure is created inside the roll, and the steel strip receives suction force from the surface of the wrapping plate, thereby preventing the steel strip from meandering.

The structure of the present invention is as shown in FIG.
A porous portion 5 is provided at a portion or multiple locations in the circumferential direction of the roll.
is installed at the center in the width direction of the roll within a range that does not exceed the minimum steel plate width, and the vacuum suction device 10 applies negative pressure to the inside of the roll through an intake passage 8 and a rotary joint 9 that communicate from the suction space 7 inside the roll to the outside. As a result, the steel plate is adsorbed onto the roll.

In addition, in order to maintain the negative pressure inside the roll while the roll is rotating, a rotation synchronizing joint 11 is installed at the end of the roll so that the suction space 7 and the intake passage 8 communicate only at the moment when the steel strip 4 and the porous part 5 come into contact. The mechanism shall be such that the opening and closing of the rotary joint are synchronized with each other.

The point of attraction when the steel strip 4 and the porous portion 5 come into contact will be explained in detail with reference to FIGS. 2(a), (b), and (C).

(a) shows the situation immediately after the steel strip 4 and the porous part 5 come into contact,
The porous portion 5, the suction space 7, and the intake passage 8 inside the roll rotate together with the roll, and the rotation synchronization joint 11 is fixed. Therefore, when the intake passage 8 and the rotation synchronization joint 11 are connected, suction occurs. (a) shows just before the start of suction, (b) shows that the intake passage 8 and the rotation synchronization joint 11 are open and suction is in progress, and (C) shows the intake passage 8
Then, the rotation synchronization joint 11 closes and the suction ends.

Therefore, the size (angle) of the rotation synchronous joint 11 is set so that suction is possible when the steel strip and the porous portion are in contact with each other.

In addition, the porous portion of the present invention may be one that has a large number of pores that can be sucked when the inside of the roll is made negative pressure.
It does not specify the shape of the hole.

(Example) The test apparatus is shown in FIG.
3 and weight 14 are installed. After measuring the initial tension, the roll was rotated and changes in the dynamic friction coefficient before and after suction with the vacuum suction pump 15 were examined.

In addition, meandering prevention was evaluated based on the amount of movement of the test steel plate when a predetermined tension was applied in the roll axis direction.

The results of these tests are shown in Table 1.

The test conditions are as follows.

・Test roll size: diameter 210 x length 340 (arm
)・Roll rotation speed: 183rpi (Roll circumferential speed:
108mpm)・Test steel plate size: Tin plate, width 12
5 Thickness 0.25 (mm) / Suction pore size: Axial direction 11
0 x Circumferential direction 80 (am) According to Table 1, the coefficient of friction between the steel plate and the roll surface after suction is improved by more than 30% compared to before suction, and the restraint in the roll axis direction (meandering prevention effect) is achieved. teeth,
Approximately 20% effect was confirmed.

Further, in FIG. 4, the present invention is applied to a hearth roll 6B in a quenching zone of a continuous annealing line, and the porous portion 5 is installed at the center in the axial direction of the roll in a range not exceeding the width of the steel plate. In this case, in order to improve performance, two locations are installed 180 degrees symmetrically with respect to the roll.

However, the roll surface shape has a necessary minimum taper angle, and the porous portion 5 is installed within the flat portion 2 shown in FIG.

In addition, the rotary joint 9 is installed at the end of the roll, and the suction pipe 19
The air is then guided to a vacuum suction device 10 for suction.

The rotary joint 9 employs a synchronization mechanism in which the interior of the roll and the suction pipe 19 alternately communicate only at the moment when the two porous portions 5 and the steel plate 4 come into contact.

With this mechanism, negative pressure inside the roll can be maintained at all times using a vacuum suction device with the minimum necessary capacity.

(Specifications) ・Line speed: 550m/i1n (M^X) ・Threading size: Board thickness 0.1 to 0.5 m, board width 500 to 1041 m
m ・Quick-cooled strip steel plate temperature: 420℃ ・Roll size 500φX1250L (m+*)・
Porous part size: 450mm (roll width direction) x 4
8 (hrta (roll rotation direction)) installed in two locations 180" symmetrically. Suction pressure -400mmHg (external atmospheric pressure)
As shown above, when used as a hearth roll in a continuous annealing furnace, wrinkles called heat buckles do not occur and it is effective as a method for preventing meandering in the furnace.

(Effects of the Invention) The present invention is effective for all sizes of steel strips, from thick to thin, wide to narrow, and is advantageous in terms of equipment efficiency. This has the effect of being able to handle high-speed sheet threading.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of a suction roll used for meandering prevention of the present invention, (a) is a side view, (b) is a front view, Fig. 2 is an explanatory diagram of the suction mechanism of the present invention, and Fig. 3 is an explanatory diagram. An explanatory diagram of the apparatus used in the example, FIG. 4 is an explanatory diagram when applied to a continuous annealing furnace hearth roll, which is another embodiment of the present invention, and FIG. 5 is an explanatory diagram of a general taper crown roll. FIG. 6 is an explanatory diagram of a roll used in the conventional meandering prevention method.

Claims (1)

[Claims] 1. A steel characterized by providing a porous part in the central part of the roll in the width direction and partially in the circumferential direction, and applying suction from the porous part to prevent meandering. How to prevent belt meandering. 2. A porous part is provided in the central part of the roll in the board width direction and partially in the circumferential direction of the roll, a suction space is provided inside the roll in the porous part, and a vacuum suction device is connected to the suction space. A meandering prevention device for a steel strip, which is connected to a suction passage through a rotary joint, and includes a rotation synchronized joint in which the suction passage opens when the steel strip and a porous portion come into contact with each other.