JPH06114414A - Projecting hot forming roller for finishing rolled channel bar and finishing method - Google Patents

Abstract

PURPOSE:To provide a means by which a channel bar the shape in pin corner parts of which is sharp and accurate and the flatness of web of which is stably manufactured regardless of the kind of material. CONSTITUTION:A projecting hot forming roller in the finishing stage of a rolled channel the cross-sectional shape of the forming part of which is constituted by having inclined straight-line parts A which are situated on both end parts, inclined straight-line parts B with a different angle from that of the parts A are connected to the circular-arc part in the middle and inclined straight-line parts C with a another different inclined angle which are connected to both the inclined straight-line parts on the point where both inclined straight-line parts A, B are crossed. Further, when the relationship among the inclined angle theta1 of the inclined straight-line part A, inclined angle theta2 of the inclined straight-line part B and inclined angle theta3 of the inclined straight-line part C, the length of the inclined straight-line part C and the length of the straight-line part of the web part of an article to be formed are adjusted so as to be a specified relation and the relative position between the inclined straight-line part C and the article to be formed is held in a specified relation, the stability of finishing is more improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot forming convex roller used in a shape shaping process for manufacturing a channel material by rolling, and a channel material having a high web flatness using the same. It is related to the shaping method for obtaining.

[0002]

2. Description of the Related Art In recent years, in metal structural members of various structures, a slight increase in cost has been tolerated, and there has been an increasing tendency toward higher corrosion resistance. Conventionally used ordinary steel and stainless steel have been increasingly used. The number of cases where "titanium (including titanium alloy)" is applied is increasing.

Further, as the size of the structure becomes larger, the demand for the shape also changes from the conventional chevron to the channel, and in terms of strength, the conventional "welded channel" is changed to "rolled". The trend of demand has come to be recognized for the "channel material manufactured in."

By the way, conventionally, when a channel material is manufactured by a rolling method, the shape of a crossing angle (hereinafter referred to as "pin angle": see FIG. 3) between the outer surface of the web and the outer surface of the flange is sharp and precise ( 90 °) is required, and thus pass-scheme rolling as shown in FIG. 4 is generally adopted. However, materials such as stainless steel and titanium having a high resistance to hot deformation have a large number of slip defects particularly with the finish rolling roll, and it is very difficult to finish the final product shape by hot rolling.

Therefore, in the case of a material having a high resistance to hot deformation as described above, the final product shape is not obtained only by hot rolling, but the thickness of the flange portion and the web portion is first obtained by hot rolling. A hot intermediate finished shape having the same W dimension as the product dimension and a curved W shape (shape indicated by i in FIG. 4) at the center of the web is obtained, and then cold or warm rolling is performed.
A method of forming a final product by two steps of flattening the curved web portion of the intermediate product by a roll forming was adopted. However, although this method is certainly effective in suppressing slip flaws, it was not sufficiently satisfactory from the viewpoint of realizing "a channel material with a sharp and accurate pin angle". .

Therefore, in order to solve such a problem, the inventors of the present invention firstly provided "flange portions at both edges of the web portion by performing hot hole rolling followed by roll forming. As shown in FIG. 5, the final cross-sectional shape in the hot hole rolling is shown in FIG.
The shape is almost W-shaped and protrudes in the direction of, and both ends of the web are straight to secure a sharp and accurate pin angle. " A method of forming a channel material by shaping it "
(Japanese Patent Application No. 63-190942).

However, it has been clarified that the above-mentioned proposed method has the following problems as a result of the examination through the actual operation which is continued thereafter. That is, according to the previously proposed method, in order to shape the intermediate product having the shape shown in FIG. 5 obtained by the hot hole rolling, as shown in FIG. And a circular arc portion in the center of the molded convex roller having a cross sectional shape of the molded portion connected by "an inclined linear portion B facing the linear portions at both ends of the article to be shaped". It was considered most preferable to promote the flattening of the part.

However, in the case of materials such as stainless steel and titanium, springback (shape restoration) is larger than that of ordinary steel, and springback occurs between the forming rollers in the shaping process (web bending forming process). However, there is a tendency that the basic forming angle θ ₂ cannot be obtained, and “actual forming angle> θ ₂ ”. Therefore, in extreme cases, this springback causes the pin corners of the molded product to come into contact with the rollers, which may cause the pin corners to lose their shape.

When the forming pressure is strengthened in order to bring the forming angle closer to θ ₂ , the pressing force of the arm portion r provided at the intersection of the inclined straight line portion A and the inclined straight line portion B also increases. There is also a tendency to cause inconvenience that depressions (pressing dents) are generated in the article-to-be-shaped web located in the convex portion and the web flatness is deteriorated.

In view of the above, the present invention has an object to use a grooved material having a sharp pin corner shape and a high web flatness, and a material having a relatively large springback. The aim is to establish means that can be stably manufactured by the roll method.

[0011]

The present invention has been completed based on the results of studies by the present inventors made from various points of view to achieve the above-mentioned object, and is shown in FIG. As described above, the hot forming convex roller used in the shaping process of the rolled channel material has a cross-sectional shape of the forming part that is "an inclined straight line portion A located at both ends" and "a center angle at a different angle. And a "sloping straight line portion B" connected to the circular arc portion and a "sloping straight line portion C having a different inclination angle connected to both the slanting straight line portions at the intersection of the both slanting straight line portions A and B". In addition, in this hot forming convex roller, as shown in FIG. 2, the inclination angle of the inclined straight line portion A is θ ₁ , the inclination angle of the inclined straight line portion B is θ ₂ , and the inclination straight line is If the inclination angle of part C is θ ₃ , [However, α = 0.8 to 1.2] holds, and if the length of the inclined straight line portion C is M and the straight line portion length of the molded product web portion is m, [However, γ = 1 to 1.5] is a point that the roller cross-sectional shape is regulated so that the following relationship is established ", and this hot forming convex roller is used. When shaping the rolled channel material in one step or in multiple steps, "when forming each step, the horizontal position of the intersection point where the extension lines of the inclined straight line portions A and B intersect is always located at the center of the straight line portion of the article web. By performing shaping while positioning, it is possible to stably obtain a rolled channel material having high web flatness with a roller pressing force that is as small as possible. "

Here, as the material of the channel member, ordinary steel,
It does not matter the type of stainless steel, titanium, etc.

[0013]

When the cross-sectional shape of the forming part of the hot forming convex roller used in the shaping process of the rolled channel is formed as shown in FIG. 1, the convex roller and the concave roller are formed. Even if a springback occurs in the molded product that is pressed between the racks and bent (shaped into a straight line), and the stress for expanding the basic molding angle θ ₂ shown in FIG. 2 occurs, Since the intersection of the inclined straight line portions A and B forms the inclined straight line portion C that is cut at an angle θ ₃ with the horizontal direction, this inclined straight line portion C
Pin corners for forming angle is corrected by the angle theta ₃ is B - La - it does not contact the surface.

Further, as described above, since the intersection of the inclined straight line portions A and B is the inclined straight line portion C forming an angle θ ₃ with the horizontal direction, this is a convex portion for shaping the molded product. In the case of pressing between the roller and the concave roller, the intersection of the inclined straight line portions A and B does not make point contact as in the conventional roller shown in FIG. The surface contact occurs due to the pressing of the molded product. Thus, the convex roller according to the present invention
Since the "face contact bending forming method" is used, even if the pressing force is increased to some extent, pressing concave marks are generated as in the "point contact bending forming method (method using the roller in Fig. 6)". Will disappear.

At this time, as described above, [However, α = 0.8 to 1.2], and [However, if the roller cross-sectional shape is regulated so that the relationship of γ = 1 to 1.5] is satisfied, the flatness of the channel member web portion is more stably improved. Here, when the α is out of the range of 0.8 to 1.2,
Due to the influence of the transitional portion r ₁ or r ₂ of the inclination shown in FIG. Also, γ
If There is less than 1, indentation marks pressing by means runs out to provide an inclined linear portion C becomes tends out, whereas, flatness (shaping degree) and γ is no longer come alive molding angle theta ₂ exceeds 1.5 poor Become.

Further, when the rolled channel profile is shaped in one step or a plurality of steps using the hot forming convex roller according to the present invention, the inclined straight line portions A and B are extended in the forming of each step. While the horizontal position of the intersection of the lines is always located at the center of the straight portion of the molded product web, that is, while the inclined straight portion C is positioned at the center of the straight portion of the molded product web (some deviation is acceptable. Of course) shaping is important for stable and proper shaping. If this position is extremely deviated, the flatness (shaping) of the product may be deteriorated, or an excessive roller pressing force may be required, so be careful.

That is, in the case of shaping using a multi-stage hot forming roller, the distance (intersection point distance: K in FIG. 2) between the two "intersection points of the inclined straight line portions A and B" is constant. Then,
As the web portion of the article to be molded extends linearly as it goes to the latter stage roller of the molding, the “distance between the pin angle and the intersection point” gradually increases, and therefore the bending moment increases and the roller pressing force increases. It becomes necessary to increase the force (forming force).
However, if the distance from the pin angle of the molded product to the intersection is always constant during each molding process (that is, if K is increased in the later stage of molding), Such a situation is avoided, and predetermined molding can be performed with a roller pressing force that is as small as possible.

[0018]

EXAMPLE First, a SUS304 stainless steel continuously cast billet was roughly rolled into a flat bar, and subsequently hot-rolled in a hole type to obtain an intermediate material having a W-shaped cross section as shown in FIG.

Subsequently, this was shaped by a 6-stage hot forming machine using a convex roller under the conditions shown in Table 1, and a thickness: 6 mm,
A stainless channel steel having a web size of 100 mm and a flange size of 50 mm was manufactured.

[0020]

[Table 1]

Next, the flatness of the web portion of the thus obtained channel steel was investigated, and the results are also shown in Table 1. As is clear from the results shown in Table 1, when the hot forming convex roller according to the present invention is used, the degree of improvement of the forming shape (flatness) is in a severe range (0.3.0.
It can be seen that even in the flatness range of 5 mm or less), a remarkable flatness improving effect can be obtained.

With respect to the number of molding passes, it goes without saying that the molded shape is improved as the number of passes is increased, but in this embodiment, the shape improving effect is in the range of "5-8".
It is said that the test has been selected with consideration of the efficiency of capital investment.

[0023]

[Summary of Effects] As described above, according to the present invention, it is possible to stably manufacture a channel material having sharp pin corners and excellent flatness regardless of the type of material. It is possible to bring about useful effects in industry.

[Brief description of drawings]

FIG. 1 is an explanatory view of a hot forming convex roller according to the present invention.

FIG. 2 is a detailed explanatory view of a hot forming convex roller according to the present invention.

FIG. 3 is an explanatory diagram of “pin angle” in the channel material.

FIG. 4 is an explanatory diagram of a channel rolling schedule of a channel material.

FIG. 5 is an explanatory diagram of a final cross-sectional shape formed by hot hole rolling.

FIG. 6 is an explanatory view of a conventional hot forming convex roller.

[Explanation of symbols]

 1 Web part 2 Flange part

Claims (3)

[Claims] 1. The cross-sectional shape of the molding part is as shown in FIG.
The inclined straight line portions A located at both ends, the inclined straight line portions B connected to the central arc portion at different angles, and the portion connected to the inclined straight line portions at the intersection of the inclined straight line portions A and B. And a hot forming convex roller for use in a shaping process of a rolled channel material, further comprising inclined straight line portions C having different inclination angles. 2. As shown in FIG. 2, the inclination angle of the inclined linear portion A is θ ₁ , the inclination angle of the inclined linear portion B is θ ₂ , and the inclined linear portion C is
Let θ _{3 be} the tilt angle of [However, α = 0.8 to 1.2] holds, and if the length of the inclined straight line portion C is M and the straight line portion length of the molded product web portion is m, [However, γ = 1 to 1.5] is satisfied, and the hot forming convex roll used in the shaping step of the rolled channel material according to claim 1 is characterized.
La-. 3. The hot forming convex roller according to claim 1 or 2 is used, and in forming each stage, the horizontal position of the intersection point where the extension lines of the inclined straight line portions A and B intersect is always maintained. A method for shaping a rolled channel material, which comprises performing shaping while being positioned at the center of a straight line portion of a web to be molded.