JP3861987B2 - Manufacturing method of welded H-section steel - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a technique for preventing a right or left twist of a welded H-shaped steel generated after welding.
[0002]
[Prior art]
As shown in FIG. 7, the welded H-shaped steel is composed of a web material 1 (also referred to as a web coil) 1 unwound from a coiled state (not shown), and upper and lower flange materials (upper and lower flanges) rewinded in the same manner. (Also called coils) 2a and 2b are manufactured by welding using a high frequency resistance welder (not shown). When welding, the web coil 1 is restrained and supported by the web guide roll 4 and the upper and lower flange coils 2a and 2b are pressed by the press-contacting roll 5 so as to be orthogonal to the web coil 1, so Positioning is performed, and the shape of the welded H-section steel is made favorable.
[0003]
However, in reality, the flange heated during welding is deformed when cooled to room temperature, and a so-called umbrella folding phenomenon occurs. Furthermore, due to various factors such as the cutting finish accuracy of the web coil end face, the flatness of the flange coil, and the balance between the web guide roll and the pressure roll during pressure contact, it deforms unbalanced up and down and left and right, resulting in the amount of umbrella folding up and down and left and right. There is a difference. FIG. 4 shows the situation of umbrella breakage occurring in the welded H-section steel. The left umbrella folding amount of the upper flange 32 is represented as l ₁ , the right umbrella folding amount is represented as l ₂ , the left umbrella folding amount of the lower flange 32 ′ is represented as l ₃ , and the right umbrella folding amount is represented as l ₄ . Further, the left angle θ ₁ between the upper flange 32 and the web 31, the right angle θ ₂ between the upper flange 32 and the web 31, the left angle θ ₃ between the lower flange 32 ′ and the web 31, and the right angle θ between the lower flange 32 ′ and the web 31. ₄ The left and right are determined for convenience in the following description and are not particularly limited.
[0004]
In the welded H-section steel production line, as shown in FIG. 7, the shape correction of the H shape has been performed by correcting the flange portion using an umbrella folding straightening machine 7.
On the other hand, the welded H-shaped steel after straightening the flange portion, when viewed only from the cross-sectional shape, the H-shaped shape itself can be corrected without any problem, but as shown schematically in FIG. There is a problem that a twist or a left twist occurs.
[0005]
For this reason, conventionally, it has been practiced to correct the twist generated by using a pressing device provided in a downstream process.
Here, the twist is defined as follows.
That is, the lower flange surface is placed on the surface plate, the thread with the weight attached from the upper flange joint 41 is drawn, and the distance between the thread and the lower flange joint 42 is defined as the twist amount. Also, depending on whether the lower flange joint 42 is on the left or right side with respect to the yarn, it is called right twist or left twist.
[0006]
[Problems to be solved by the invention]
However, in the method of correcting torsion with a press device, it takes time to correct and the manufacturing cost increases. Further, when the twist is large, it is also a problem that the press device cannot completely correct.
The present invention eliminates the cause of torsion itself, eliminates the need for twist correction processing in the downstream process, and realizes efficiency improvement and cost reduction of the welded H-section steel production line.
[0007]
[Means for Solving the Problems]
The present inventor has investigated the cause of the torsion occurring in the welded H-section steel, and found that the cause is that the correction in the flange umbrella folding correction in the umbrella folding correction machine is due to left-right imbalance.
The case where the flange umbrella breakage is as shown in FIG. 8A will be described. This is a case where the amount of umbrella folding becomes asymmetrical with respect to the web as a center, and in particular, the amount of umbrella folding on the diagonal increases. That is, this is a case where l ₁ >> l ₂ and l ₃ << l ₄ . Therefore, the diagonal reduction (direction is indicated by 34) in the umbrella folding straightener becomes large, and the reduction is unbalanced with respect to the web, and a rotational moment is generated. This is the main factor, and the twist shown in FIG.
[0008]
The present invention has been made for the purpose of fundamentally eliminating the above-described torsion factors, and has solved the above problems by a method for producing a welded H-section steel described below.
1. A welded H-section steel manufacturing method that prevents torsion of a welded H-section steel when a web coil and a pair of upper and lower flange coils are manufactured by high-frequency welding while being restrained and reduced by a web guide roll and upper and lower press-contact rolls. there are a high-frequency welder umbrella folding detectors are placed after the, than bevel fold detector and umbrella folded straightener is disposed downstream, the umbrella fold detector up and down right and left flange end 4 points umbrella fold amount detecting the in, based on the umbrella fold of four positions and said detection, said upper and lower flange and the upper flange the an angle relative to the web when viewed in cross-section formed by the web web a left angle and right angle formed between calculates a left angle and right angle formed between the the lower flange webs, the left and right unbalance umbrella fold amount with respect to the upper and lower flanges at an angle difference between the calculated left angle and right angle To the control device Ri, said angle difference by the feedback to be within a predetermined value, the manufacturing method of welding H-beams to the web guide roll and the upper and lower features and Turkey to control the slope of the pressure roll.
2. 1. The left and right unbalance of the amount of folding of the umbrella is within ± 1 ° both in the vertical direction due to an angle difference . The manufacturing method of the welded H-section steel as described in 2.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
A preferred embodiment of the method for producing a welded H-section steel of the present invention will be described with reference to FIG. In addition, the same number is attached | subjected to the member same as the member already demonstrated in FIG. 7, and description here is abbreviate | omitted.
The present invention detects by a detector 6 fold umbrella umbrella fold amount of H-shaped steel 3 immediately after the welding, on the basis of the detected umbrella fold amount, the inclination of the web guide roll 4 and the pressure contact roll 5 at the welding position It is something to control. And by controlling the inclination of those rolls, the inclination of the web coil 1 and the upper and lower flange coils 2a and 2b is controlled, and the purpose is to eliminate the left-right imbalance of the amount of umbrella folding occurring in the welded H-section steel. To do.
[0010]
FIG. 2 shows the arrangement of the web guide roll 4. Also shows the arrangement of the pressure contact roller 5 in the upper and lower in FIG. The tilting means 8 shown in FIGS. 2 and 3 is not particularly limited. For example, a hydraulic cylinder, an electric screw gear, or the like can be suitably applied. And the both ends of a roll are crushed independently by those means, and it becomes possible to incline a roll freely.
[0011]
On the other hand, the umbrella break detector 6 detects the amount of umbrella breakage of the flange by measuring the amount of displacement at the four flange ends at the upper left and right of the upper limit in the cross-sectional direction of the welded H-section steel. For the measurement of the displacement amount, a contact type touch roll displacement meter, a non-contact type laser displacement meter or the like can be suitably applied.
In the present invention, the amount of umbrella folding detected by the umbrella folding detector 6 is taken into the control device 10, a predetermined calculation is performed, and the left and right angles of the upper and lower flanges and the web are calculated based on the amount of umbrella folding. the fed back to calculate the tilt amount of the web guide roll 4 and the pressure contact roll 5, and controls of those roles inclined. By doing so, it becomes possible to control the inclination of the web coil 1 and the upper and lower flange coils 2a, 2b, and the left / right balance of the amount of folding of the umbrella can be evenly controlled.
[0012]
In addition, it is preferable that the left-right angle difference between the flange and the web is within ± 1 ° both in the vertical direction. This is because by setting the angle within ± 1 °, the generated twist can be within ± 3 mm which is a standard allowable range for an H-shaped steel having a web length of 100 to 300 mm.
By the way, the control device 10 may be added with a function of calculating a correction amount of umbrella folding correction in the umbrella folding correction machine 7 based on the input umbrella folding amount and performing feedforward control. By doing so, it is also possible to fully automate the umbrella folding correction and the twist correction of the welded H-shaped steel at the same time.
[0013]
【Example】
First, an application example of the method for producing a welded H-section steel of the present invention will be described.
FIG. 6 shows an application of the present invention, sampling the welded H-section steel produced on the welded H-section steel production line, and the actual amount of torsion and the left-right angle difference (θ ₁ −θ) between the flange and the web. It is a graph showing the relationship of ₂ ).
[0014]
From FIG. 6, it is apparent that in the method of the present invention, the relationship between the twist amount of the welded H-shaped steel and the left-right angle difference (θ ₁ −θ ₂ ) between the flange and the web is almost linear. That is, both are in a proportional relationship. In particular, in order to make the amount of twist within the standard tolerable range of ± 3 mm or less, if the left-right angle difference (θ ₁ −θ ₂ ) between the flange and the web is controlled to be within ± 1 °. It is clear that it is good.
[0015]
As described above, in the present invention, the twist generated in the welded H-section steel can be eliminated in advance at the welding stage, and press correction in the downstream process can be made unnecessary.
On the other hand, in the conventional manufacturing method in which the inclination of the web coil and the upper and lower flange coils is not controlled, the torsion of the welded H-section steel cannot be controlled, so that a large torsion occurs, and the direction and amount of the torsion generated vary. It becomes. Therefore, time-consuming press correction in the downstream process is essential.
[0016]
【The invention's effect】
The present invention eliminates the need for press correction in the downstream process, and makes it possible to efficiently produce a welded H-section steel having excellent shape quality with little torsion at low cost.
[Brief description of the drawings]
FIG. 1 is a schematic view for explaining a method for producing a welded H-section steel of the present invention.
FIG. 2 is a schematic view showing a control operation of a web guide roll.
FIG. 3 is a schematic diagram showing a control operation of a pressure contact roll. FIG. 4 is an explanatory diagram defining a flange umbrella folding amount.
FIG. 5 is a schematic diagram for explaining the twisting phenomenon of welded H-section steel.
FIG. 6 is a graph showing the relationship between the left-right angle difference (θ ₁ −θ ₂ ) between the flange and the web and the twist amount of the welded H-section steel.
FIG. 7 is a schematic diagram for explaining a conventional method for producing a welded H-section steel.
FIG. 8 is a schematic diagram for explaining the cause of twisting of welded H-section steel.
[Explanation of symbols]
1 Web coil (web material)
2a Upper flange coil (material for upper flange)
2b Lower flange coil (lower flange material)
3 Welded H-shaped steel 4 Web guide roll 5 Pressure contact roll 6 Umbrella break detector 7 Umbrella break corrector 8 Inclination means
10 (Coil tilt) control device
31 Web (of welded H-section)
32 Flange (of welded H-section steel)
34 Rolling direction (to correct umbrella breakage)
41 Upper flange joint
42 Lower flange joint θ ₁ Upper flange and web left angle θ ₂ Upper flange and web right angle (θ ₁ −θ ₂ ) Difference between right and left angles of flange and web θ ₃ Lower flange and web left angle θ ₄ Lower flange And the right angle of the web 1 ₁ Left umbrella folding amount 1 ₂ Upper flange folding amount 1 ₃ Upper flange folding amount 1 ₃ Left flange folding amount 1 ₄ Lower flange folding amount

Claims (2)

A welded H-section steel manufacturing method that prevents torsion of a welded H-section steel when a web coil and a pair of upper and lower flange coils are manufactured by high-frequency welding while being restrained and reduced by a web guide roll and upper and lower press-contact rolls. there are a high-frequency welder umbrella folding detectors are placed after the, than bevel fold detector and umbrella folded straightener is disposed downstream, the umbrella fold detector up and down right and left flange end 4 points umbrella fold amount detecting the in, based on the umbrella fold of four positions and said detection, said upper and lower flange and the upper flange the an angle relative to the web when viewed in cross-section formed by the web web a left angle and right angle formed between calculates a left angle and right angle formed between the the lower flange webs, the left and right unbalance umbrella fold amount with respect to the upper and lower flanges at an angle difference between the calculated left angle and right angle To the control device Ri, said angle difference by the feedback to be within a predetermined value, the manufacturing method of welding H-beams to the web guide roll and the upper and lower features and Turkey to control the slope of the pressure roll. Wherein an angle difference left and right unbalance umbrella fold amount, method for producing a welded H-shaped steel according to claim 1, characterized in that within ± 1 ° as the upper and lower.

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