JPS6289512A - Outlet side device for cold rolling mill - Google Patents

Abstract

PURPOSE:To restrain abnormal tensions and to prevent generation of off-gage of a strip by installing a tension buffer between the final stand and a tension reel and moving a deflector roll in the direction in which a loop length is shortened. CONSTITUTION:When a strip S is wound on a tension reel 3 and an energy of rotating inertia of the tension reel 3 is emitted, the energy acts as a tension on the strip S to increase the tension of the strip S. When the increased tension acting on the strip S reaches a tension value set on a buffer 6, a deflector roll 5 is moved by the buffer 6 supporting the roll 5 in the direction in which a loop length formed by deflector rolls 5 and 5' is shortened. The strip S positioned at the loop part is supplied to the reel 3 to prevent the increased tension from acting on the rolling mill 1 side and the buffer 6 absorbs the increased tension, converts the absorbed tension into a heat energy by friction, and dissipates the energy.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a cold rolling mill installed between a cold rolling mill and a tension reel for winding a strip formed by the rolling mill into a coil shape. Regarding equipment on the exit side of the machine,
More specifically, the present invention relates to equipment that prevents excessive tension from being applied to the strip at the initial stage of winding the strip onto a tension reel.

[Conventional technology]

Generally, as shown in FIG. 5, a tension reel 3 is installed on the exit side of a cold rolling mill 1.

The rolled strip S is wound around this tension reel 3 to form a coil.

Generally, the method of winding the tip of the strip S around the tension reel 3 is to wrap the strip S around the feeding belt wrapper 2.
The tension reel 3 is wound at a circumferential speed of rotation of the tension reel 3 that is approximately 10% higher than the feeding speed of the strip S.

When winding the strip S around the tension reel 3, the rotational inertia energy of the tension reel 3 is released at the moment the tip of the strip S is tightly wound around the tension reel 3.

This will be converted into a tension force acting on the strip S.

By the way, the tension reel 3 is a very large machine, and the motor that rotates the tension reel 3 also has a large capacity.

The rotational inertia energy released by the tension reel 3 is extremely large.

In this way, the rotational inertia energy released by the tension reel 3 is very large, and this released rotational inertia energy is converted into strip tension, so the moment the strip S is wound onto the tension reel 3, it becomes extremely tight. A large tension on the exit side was generated, and this tension on the exit side was the cause of strip-off gauge (deviation in plate thickness).

Figure 6 shows actual measurements of the fluctuation state of the tension acting on the strip S with a thickness of 0.6 nm and a width of 10,000 mm at the initial stage of winding it around the tension reel 3. It can be seen that the tension decreases from time t3, but rapidly increases at time t4 when the subsequent strip is wound. The increase in tension during the subsequent winding of the strip reached approximately 2.87 on.

In plate rolling, when tension is applied to the exit side, the rolling load decreases, and the instantaneous tension fluctuations described above result in a habitual decrease in the rolling load, and due to the interaction with the elasticity of the mill, off-gauge will occur.

Figure 4 shows the relationship between plate thickness, rolling load, and mill rigidity. Here, the intersection of the mill elasticity line C and the material plasticity line 2 under normal tension is the outlet side plate thickness, but as the tension increases When the material changes, the slope of the material plasticity line changes in the decreasing direction and becomes the characteristic line E, causing off-gauge to occur toward the thinner plate side.

Since this phenomenon is a transient phenomenon, it is not possible to correct the plate thickness using AGC or the like.

[Problem that the invention seeks to solve]

As described above, as a conventional means for preventing the adverse effects caused by the abnormal tension that occurs at the initial stage when the strip S is wound around the tension reel 3, a slip coupling, for example, is interposed in the drive system of the tension reel 3 to prevent the generation of abnormal tension. There is a means to prevent this (Japanese Unexamined Patent Publication No. 53-62063), but in the case of this means, if a slip coupling is provided on the high speed side (motor side), the entire driven body beyond this slip coupling The rotational inertia of the mechanical system causes abnormal tension in the strip S, and if it is installed on the low speed side (reel side), the required maximum transmission torque will be extremely large, so it is necessary to install a slip coupling. There is a problem in that it requires a large capacity.

The present invention was devised to solve the problems and drawbacks of the conventional examples described above, and its purpose is to suppress the abnormal tension that occurs when the slip wraps around, thereby preventing the occurrence of off-gauge of the strip. .

[Failure to solve the problem]

Hereinafter, one embodiment of the present invention will be explained with reference to drawings showing nine embodiments of the present invention.

The outlet equipment of the cold rolling mill according to the present invention is configured to release the rotational inertia energy of the tension reel 3 by two mechanical methods without generating abnormal tension in the strip S. At least two tension reels 5, 5' forming a loop in the running path of the strip S between the final stand and the tension reel 3.
and a buffer body 6 for supporting at least one of the tension reels 5, 5'.

The buffer body 6 described above prevents the tension applied to the strip S from exceeding a preset value when a tension greater than a preset value is applied to the strip S.

It has a function of moving the supported tension reel 5 in the direction of shortening the loop length formed by the tension reel 5.

Although the shape and length of the loop formed by two or more tension reels 5, 5' are not specified,
The energy released by tension reel 3 is not instantaneous,
In order to allow the release to take some time, it is desirable that the length of the loop formed by two or more tension reels 5.5'' is quite long.

That is, as shown in characteristic curve A in FIG. 3(a), when the tension reel 3 releases a certain amount of energy A, which is rotational inertia energy, during an extremely short time t1, the tension acting on the strip S increases. While the fluctuation value instantaneously reaches an extremely large value, tension P1,
As shown at the characteristic curve in FIG. 3(b), when the tension reel 3 releases a certain amount of energy A, which is rotational inertia energy, over a reasonably long time L2, the fluctuation value of the tension that acts on the strip S. is up to the tension P2, which is a small value, and there is no need to apply large tension fluctuations to the strip S. Therefore, it is possible to absorb the rotational inertia energy released by the tension reel 3 over a long period of time. Therefore, it is desirable that the length of the loop formed by the deflector rolls 5 and 5° is considerably long.

In addition, as the shock absorber 6, a spring or a damper is generally considered, but in the case of one spring, it functions effectively to absorb continuous vibrations, so the tension reel 3 is released. It seems effective to use a damper to absorb the rotational inertia energy over a certain amount of time.

That is, as shown in FIG. 1, one deflector roll 5 is supported by a buffer body 6 using an oil damper, and the set tension of this buffer body 6 is set approximately 5 to 30% higher than the steady tension of the strip S. By doing so, the tension acting on the strip S will never exceed the set tension of the buffer 6, and the length of the loop may be made long enough to obtain the set tension.

[Effect]

Since the outlet equipment according to the present invention has the above-described configuration, when the strip S is wound around the tension reel 3 and the rotational inertia energy of the tension reel 3 is released, this released rotational inertia energy is transferred to the strip S. This acts as a tension force on the strip S, increasing the tension force acting on the strip S.

When the tension acting on the strip S increases and reaches the tension value set in the buffer 6, the buffer 6 shortens the loop length formed by the deflector roll 5 supported by the deflector roll 5. The strip S located in this loop portion is supplied to the tension reel 3, thereby preventing the increased tension from acting on the rolling mill 111J, and the buffer body 6 absorbing the increased tension. Moreover, this absorbed tension is converted into thermal energy by resistance and dissipated.

The displacement of the deflector roll 5 in the buffer body 6, the absorption of tension greater than a set value, and the dissipation of the tension by converting it into thermal energy continue as long as the rotational inertia energy is released from the tension reel 3.

In this manner, the outlet equipment according to the present invention absorbs the released rotational inertia energy of the tension reel 3 by the release of the storage strip S from the loop and the resistance of the kFtiE body 6, so that the tension acting on the strip S is reduced. does not become larger than the set tension of the buffer body 6, and therefore the strip S does not cause strip off gauge.
can be safely wound into a coil.

That is, one reason is that the deflector roll 5 used in the present invention has a small weight and therefore has a small inertial force.

Abnormal tension that would affect the strip S is not generated.

In addition, in the tension absorbing operation of the present invention, an extra length of strip S is pooled in the loop in advance.

Since this extra pooled strip S is released according to the increasing tension, the increased tension will not act on the rolling mill l side even if it is instantaneous, and this will prevent the thickness variation of the strip S from occurring. Good rolling operation of the rolling mill 1 can be maintained without any occurrence of this problem.

And unlike strip couplings, it does not rely on friction sampling, which includes uncertain elements, so it is easy to set the tension.

Furthermore, it can be carried out by simply installing a tension buffer device 4 with a simple structure between the outlet side of the rolling mill 1 and the tension reel 3, and it is possible to modify the complex and large tension reel 3, or use other parts such as dog breeds. There is no need to modify the assembly at all.

Note that the tension set in the buffer body 6 is the same as that of the strip S.
Needless to say, it is adjusted and set depending on the dimensional conditions, molding conditions, etc.

〔Example〕

The embodiment shown in FIG. 2 shows an example in which a hydraulic cylinder is used as the shock absorber 6. The shock absorber 6 using this hydraulic cylinder has a relief pulp 7 operated by a solenoid valve 8. Connected as a brake circuit.

The loop of the strip S is formed by two deflector rolls 5', 5' immovably arranged at a distance along the conveyance line of the strip S, and these two tension reels 5.
', 5' and one deflector roll 5 supported movably by a buffer body 6 in a direction transverse to the conveyance line of the strip S.

The reason why the loop of the strip S is formed in the above-described form is because in an actual line, it is necessary to make a loop for every coil, and also because it is preferable that the path of the strip S be a straight line during threading.

That is, when threading the strip S, the tension reel 5 is lowered to the lower limit position below the path of the strip S, and when threading of the strip S is completed, the tension reel 5 is simply raised. This means that a loop can be formed, and the handling of the strip S for loop formation becomes extremely easy.

The setting tension in the tension buffer device 4 shown in FIG. 2 is determined by the relief pulp 7.

In the example shown in the second figure, only one loop was formed, but if you want to obtain a longer loop length,
This can be easily achieved by forming a plurality of loops.

〔Effect of the invention〕

As is clear from the above description, the cold rolling mill exit equipment according to the present invention can reliably and smoothly prevent the occurrence of abnormal tension at the initial stage of coil winding of the strip, thereby preventing the occurrence of strip off gauge. It is possible to reliably prevent this and produce good products with no variation in plate thickness, and by installing a tension buffer device in the area between the rolling mill exit side and the tension reel where there is sufficient installation space. Since the structure of this tension buffer device is extremely simple, it is easy to implement and handle, and furthermore, it is possible to reliably prevent an increase in abnormal tension, thereby achieving a significant improvement in yield. It has many excellent effects, including the ability to

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing the basic configuration of the present invention. FIG. 2 is an explanatory diagram showing a specific configuration of the present invention using a hydraulic cylinder as a shock absorber. Figure 3 is used to explain the absorption operation of the released rotational inertia energy of the tension reel.
) is a characteristic diagram showing the change in tension when rotational inertia energy is absorbed over a short period of time, and FIG. 3(b) is a characteristic diagram showing the change in tension when rotational inertia energy is absorbed over a long period of time. FIG. 4 is a characteristic diagram showing the relationship between mill rigidity, material plasticity line, plate thickness, and rolling load. FIG. 5 is a diagram for explaining how the tip of the strip is wound around the tension reel. FIG. 6 is a graph showing actually measured changes in strip tension that occur when the strip is wound. Explanation of symbols 1; Rolling MI! , 2; Belt trapper, 3; Tension reel, 4; Tension buffer, 5t5'; Deflex crawl, 6; Buffer, 7; Relief pulp, 8; Solenoid valve. Applicant: Kawasaki Steel BUZO Co., Ltd./a Doshi~Sho Junki 3-1-kun>M Goop 4-=
4. Sound fJ/IfJ15.5'-F-yt, 7) 7a-
yt-6=-1i1fl14 huge bulge (a) (b) 4/%f

Claims (1)

[Claims] At least two deflector rolls (5) forming a loop in the running path of the strip (S) between the final stand of the continuous cold rolling mill (1) and the tension reel (3).
(5') and a buffer (6) supporting at least one of the deflector rolls (5) and (5'). When a tension equal to or greater than a preset value is applied to the strip (S), the supported deflector roll (5
) in the direction of shortening the loop length.