JPH0335002B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a method for manufacturing a rib material having a J-shaped cross section, and in particular, a method for manufacturing a J-shaped steel by hot rolling, and a method for cold-cutting this J-shaped steel. The present invention relates to a method of manufacturing a J-shaped rib material obtained by.

In recent years, with the development of shield construction methods in tunnel construction, steel segments that can withstand earth pressure, water pressure, and surface loads have been commonly used, but there has been a growing demand for improved strength of the segments themselves.

As is well known, vertical rib members are arranged on steel segments to receive the reaction force of the jack for shield propulsion, and also to transmit the load as a ring and to prevent buckling. Thick vertical rib materials are now required.

By the way, vertical rib members have conventionally been manufactured by press molding, but the following problems are inherent.

That is, a steel plate or flat steel cut into a width W ₁ thickness t ₁ as shown in Fig. 1 is pressed by an upper mold with a radius of R against a lower mold with a force of P in a press machine and bent at 90°. It is formed into a J shape with the required flange length on the left and right sides. At this time, the area around the R portion becomes thinner in the width direction at the same time as the deformation, creating a difference in thickness from the flange.

That is, as shown in Fig. 2, t ₂ < t ₁ , and the total length of the processed flange W ₂ is longer than the width of the plate before processing W _1.For this reason, a soft material with good bending performance is used as a material that requires bending. A material with good elasticity is required. In addition, in the case of 90° bending, the radius of the upper die is as small as 1.5 times the plate thickness, so when the plate is bent, cracks are likely to occur at the end on the side where the plate stretches.

For this reason, when cutting a member from a steel plate, first, the length of the required workpiece is determined to be the width of the slit, and the steel plate is cut and divided in the length direction using a frame planer. After that, since gas cutting causes bending due to thermal distortion, the workpiece is cut to the width with a jar to produce a member of predetermined dimensions. The purpose of this cutting method is to prevent the occurrence of cracks by bending the steel plate in a direction perpendicular to its rolled length.

Furthermore, when cutting a member from flat steel, the flat steel is inevitably bent around the direction in which it was rolled, so cracks are likely to occur. For this reason, it is necessary to apply heat to the edges before bending to prevent the occurrence of cracks, and a process is added to keep the cracks small even if they occur.

Also, flat steel is cut to a predetermined length with a shear,
As shown in FIGS. 3a and 3b, when the board is cut with a shear, small burrs are generated in opposing directions on the upper and lower surfaces of both ends of the board. When this member is bent at 90° with a small R around the length direction, when the burred surface is on the lower mold side as shown in Figure c, the R part on the outside of the plate will stretch. Cracks are likely to occur from this burr part.

The present invention solves the above-mentioned problems, and its gist is that when producing a section steel with a flange by hot rolling, a flat steel plate having a thickness of 1.5 to 2.5 t, which is the product thickness t, is formed. Then, the left and right intersections of the flanges are introduced into a subsequent groove series having an R-shape, and the R-shape is successively approximated to the product shape, and one pass of the final groove roll and the final groove roll is introduced. In a guiding device having right and left rigid guide rolls between the previous forming hole type rolls, an intermediate bend is applied to the material to be processed, and a final hole type roll with the flange tips of the short side and long side on the same horizontal plane forms a J-shape. Shape,
Finish rolling by smoothing the left and right flange end faces,
This is a method for manufacturing a J-shaped rib material, which is characterized by cutting to a desired length.

In the present invention, a deformed shaped steel having a J-shaped cross section and given a predetermined radius is particularly referred to as a J-shaped steel.

In the past, various types of steel sections have been produced by hot rolling, and when producing section steel by hot rolling, a - size - hole series method is used.

The inventors have developed a product with a thickness of 1.5 to 2.5 by hot rolling.
The steel material, which has been formed into a flat steel shape with twice the thickness, is gradually formed into an R shape in the subsequent 4 passes, and the tips of the left and right flanges are shifted to become flat, and the 6th hole is formed in the final hole mold. A J-shaped steel having a desired cross-sectional dimension as shown in the figure is manufactured.

FIG. 5 shows a conventional example of scalene angle steel. The basis of design and manufacturing is that the tops y of the ridges where the left and right flanges intersect are at right angles, and the tips of the flanges are rounded at r ₁ and r ₂ . In the present invention, on the contrary, the holes formed in the flat steel shape are rounded at the intersections of the flanges in all four passes, and the tips of the flanges are formed flat. Furthermore, this J-shaped steel is cold cut to a predetermined length to produce a desired rib material.

Therefore, the rib material according to the present invention has the same wall thickness over the entire length, and the wall thickness of the portion given the 90° radius and the end portion can of course be made equal.

In addition, the opening points O ₇ , O ₈ ... O ₁₀ of the roll hole type from st7 to st10 in Fig. 4 are arranged alternately on the upper roll side and the lower roll side, and the flange end faces Q ₁ , Q ₂ of Fig. 6 are arranged alternately on the upper roll side and the lower roll side. Since it is formed to be smooth at right angles, there is no need for additional groove processing when welding and assembling the rib material into segments.

The present invention will be explained below with reference to the drawings.

The manufacturing method of the present invention is shown in FIG. Cross section A,
B, C...M, N indicate the hole shape of each roll when manufacturing a flat steel having an S cross section with a thickness tx and a width W.

st1~1, 2, 3, 4 indicate rough rolling passes,
A billet with a cross section of A changes to B, C, D, and E. st2 and st3 are intermediate rolling passes, and F and G are respective cross sections. The steel material in the cross section of G is st4...
By rolling up to st10, the cross section changes to H, I...N. st10 is the final roll.

By changing the dimensions and shapes of each of these holes, flat bars of various sizes are manufactured. J-shaped steel is
In the figure, the flat steel rolling method is used up to st6. However, the cross section of T has a thickness t ₆ ' that is 1.5 to 2.5 times the flange thickness t of the product indicated by Z, and the width is also adjusted to W ₆ '. Accordingly
The shape and dimensions before I of st5 are also adjusted so that a T cross section can be obtained.

As is well known, when making scalene angle steel as shown in Fig. 5, the left and right flange side lengths are different, so when the rolling reduction is large, the component force in the horizontal axis direction on the long side is large, so the thrust works, and the upper roll tends to escape to the long side. As a result, the thickness of the left and right flanges becomes unequal, and a lack of wall thickness, which is called sagging, occurs at the apex angle y. In particular, the J-shaped steel according to the present invention has a large radius at the intersection of flanges, unlike ordinary angle steel.
Because of this, the rolled steel tends to escape to the long sides. In addition, the flange tip needs to be finished flat as shown at Q ₁ and Q ₂ in Figure 6 to improve welding conditions.

For this reason, in the hole shapes U, V,
As will be described later, we have taken precautions to prevent the rolled material from escaping to the left and right, and we have also taken measures for the guiding device.

R ₂ at the top and R ₁ at the bottom of the 4-pass flange intersection from hole type U of st7 to hole type Y of st10 in Figure 4
and all were set to the same R. In addition, R ₂ and R ₁ of the flange intersection from hole type U of st7 to hole type X of st9 and the intersection of the left and right flat flange portions are connected by R ₇ , which is the same for all three passes. In addition, the rising angles θ of the hole shapes U, V, X, and Y are all 90°.

With the above-mentioned hole configuration, the rounded rising portion of the flange intersection portion that does not have a triangular apex angle is tightly hugged by both sides of the upper and lower rolls. Also, the width of the holes from st7 to st10, from _W7 to _W10 , should be the same in order to prevent the steel material from waving. However, W ₇ > W ₈ ,
If W ₈ > W ₉ , make the front hole slightly wider than the rear hole. Therefore, in order to avoid unfavorable biting conditions, an inlet fuel ring with a roller as described later is provided.

Also, when the steel material is rolled down, the overall length and width of the flange gradually increases. Although the relationship between this lateral spread and the above-mentioned making the hole width approximately equal is contradictory, h ₇ <
h ₈ <h ₉ is accommodated by raising the height of the R portion of the flange intersection. This means that the height will gradually approach h ₁₀ of the final hole shape,
It also has the effect of improving chewing.

Also, the rising angles θ (90°) of the flange intersections with R from st7 to st9 are equally distributed by 45° at the center line with respect to the horizontal axis of the roll. When the final hole Y is placed on the roll with equal distribution of 45 degrees along the center line as shown in Figure 6,
When the X of st9 bites into the Y of st10, the left and right flanges are unbalanced, making it difficult to bite, and
Left and right side blurring is likely to occur.

In order to eliminate these drawbacks, as shown in the Y hole shape of st10, the center line is tilted by η with respect to the horizontal axis of the roll so that the flange tips e and e' on the short side and long side are on the same horizontal plane. Make it. This allows the left and right flanges to simultaneously fit the X-section steel material exiting st9 into the Y-section hole at st10.

Fig. 4. The flat parts near both ends of the left and right flanges of the hole pattern after st7 are made on the same horizontal plane as much as possible, and the O ₇ , O ₈ , O ₉ , and O ₁₀ ends are alternately raised and lowered in accordance with flat steel rolling. Make sure to apply it with a roll and improve welding conditions.

Furthermore, in order to stabilize the guidance of steel materials to the rolls, among the guidance devices at each entrance from st7 to st10,
A guide roller is attached to the fuel ring so that the left and right flanges engage the roll through rotational contact. A fuel ring made of a steel plate or cast wears due to friction with the tip of the flange of the rolled material, making the product unstable.

In FIG. 7, f shows the fuel ring, e shows the guide roller, and a shows the cross section of the steel material during semi-insertion. The entrances of st8 and st9 are provided with an upper slit in Figure 7 b and a lower slit in c.
Align the cross section of the hole before inserting into the next hole with the shape of the top and bottom of the slivers, and keep the center of the R-shaped rising part of the steel material with the top and bottom slivers. Both the upper and lower entrance sides are designed to be easy to enter.

Next, FIG. 8 shows the final st10 inlet sucella for the Y hole type. Inlet and outlet fuel lungs, exit funds, etc. are omitted. j and k in Fig. 8a are rolls, and the X-shaped steel material exiting st9 is st10
It passes through the roll hole type Y and becomes a Y J-beam.
b' indicates the upper slope of the entrance, and c' indicates the lower slope of the entrance. In addition, the procedure for lower slicing is the same as in b and c in Fig. 7.

The steel materials held by the slides b' and c' are shown in Figure 8a.
The shape of the inside of the upper and lower slides is that the cross section on the entrance side is X (view A-A), but B
-B), it gradually deforms and takes the shape of an i at view B-B. i is st9 x and st10
It has a flange portion with a medium slope of the Y cross section.

The steel material with cross section
While passing through view B-B, the flange portion is deformed into the shape of an i by the upper and lower slivers and is bitten into the YK hole shape of st10. The middle bending of the flange makes it very smooth to fit into the final hole mold. This slat is made of special heat-resistant steel to prevent seizure.

By using the above groove roll and guiding device, the intersection of the flanges has the required radius in the final groove, the left and right flanges tips are flat, and the thickness of the flange is equal to t in all parts. Manufactures J-beam steel. Equilateral J-beams with equal left and right flange lengths are manufactured in exactly the same manner.

In the present invention, the steel material is rolled by the flat steel rolling method until the middle of hot rolling to obtain a flat steel cross section with a thickness of 1.5 to 2.5 times the thickness of the product, and then the right and left intersections of the flanges are further rounded. By passing the rolls of the trailing hole series 4 times, the R-shape gradually approaches the product shape, and the ends of the left and right flanges are shaped smoothly, and the rolling is completed. A further feature is that the desired rib material is manufactured by cold cutting.

Since the J-shaped steel obtained by the present invention can have the R part as thick as or thicker than the flange part, it has higher strength than cold-formed steel if the dimensions are the same. benefits can be obtained. Furthermore, if the rib material is melt-cut from a steel plate and then cut using a shear, fusing residue and cutting burrs will be attached, which are removed using a grinder, but there is no need for that effort.

Furthermore, when cutting flat steel to a predetermined length, cutting burrs occur at both ends, and cracks are likely to occur during bending, but since no bending is performed, no cracks occur. There is no need for heat treatment of the edges or anything else. Furthermore, for products with dimensions that are used in large quantities, if a product that has been hot-formed and then cut into a predetermined length is used, steps such as press molding can naturally be omitted.

Also, if the dimensions are the same, it is possible to make a material that is stronger than cold-formed steel plates or flat steel. Furthermore, since there is no need to consider bending performance, materials with good corrosion resistance can be used. Moreover, since it is manufactured by hot rolling, it is possible to measure long lengths. Therefore, it can be applied to shipbuilding parts, vehicle parts, civil engineering construction parts, and other general machine parts.

In addition, members of a predetermined length, such as segment materials, can be delivered in the required amount at the required time, which simplifies the management work of the user's processing factory, including the material yard, horizontal handling work, rust prevention, and other tasks. Furthermore, the product can be manufactured by taking advantage of the opportunity of flat steel rolling and changing only four rolls with hole shapes of J-shaped steel, so the effort required for rearranging can be reduced.

Examples of the present invention will be described below.

After producing regular flat steel using a shape rolling mill, the four rolls in the finishing row are rearranged to produce st7, st8, st9, and
st10 was made into a J-shaped steel roll.

A billet of size 124 x 124 (material SM50) is heated to 1150℃ in a heating furnace, flat steel rolling method is used up to finishing row st6, and a flat steel cross section with a thickness of 17 mm is obtained at st6.
This was passed through the rolls of the groove series st7 and later of the present invention as it was, to obtain a J-section steel with a final groove thickness of 8 mm and a rolled flange length of 150 mm.

The above-mentioned J-shaped steel was welded and used as a vertical rib material of a steel segment made of SM material, and the reaction force and buckling prevention force were equal to or superior to those of conventional press-formed vertical rib material. .

It was estimated that manufacturing costs could be reduced by approximately 30%.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a flat steel plate, Fig. 2 is a schematic diagram of conventional press working, Fig. 3 is an explanatory diagram of the process of the conventional example, Fig. 4 is an explanatory diagram of the process of the present invention, and Fig. 5 is the conventional example. 6 is a cross-sectional view of the rib material of the present invention. Figure 8 is an explanatory cross-sectional view of the inlet slat associated with the hole shape of the present invention. Figure 8 is a cross-sectional view of the inner shape of the inlet slasse. It is an explanatory diagram showing a change. 10... flat steel plate, 12... shear, 13... burr, 14... crack.

Claims (1)

[Claims] 1. When manufacturing a section steel with a flange by hot rolling, a flat steel plate with a thickness of 1.5 to 2.5 t, which is the product thickness t, is formed, and the left and right intersections of the flange have an R-shape. Introduced into the hole type series and sequentially R
In addition to approximating the shape of the product to the shape of the product, a guide device having left and right rigid guide rolls between the final groove roll and the forming groove roll one pass before the final groove roll performs intermediate bending on the material to be processed. The flange tips on the short and long sides are shaped into a J shape using a final groove roll with the same horizontal plane, the end surfaces of the left and right flanges are smoothed, the rolling is finished, and the product is cut to the desired length. A method for manufacturing J-shaped rib material.