JPS5972348A - Mold structural member of welded structure and production thereof - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a welded type structural member and a method for manufacturing the same.

BACKGROUND OF THE INVENTION Structural members, particularly those used for bridges or building beams, require bending rigidity among various strengths, and the magnitude of the second moment of area serves as a design standard. For this reason, large-sized structures such as bridges use mold structural members with large cross-sections and large moments of inertia. This type structural member is, for example, I-type, box-type,
C type.

It has a cross-sectional shape such as L-shape, and most of them have a welded structure in which a web member and a flange member are integrated by welding.

Normally, when using the same metal, it is desirable that the weight be smaller if the strength is the same, and in the case of the above-mentioned mold structural members, since the contribution to the second moment of area near the neutral plane of the web portion is small, While maintaining the bending rigidity of the structural member substantially constant, weight reduction can be achieved by reducing the wall thickness near the neutral plane (2).

Conventionally, in order to provide a difference in thickness in the width direction of the web portion, materials having different thicknesses have been welded together.

That is, the web member is formed by welding a long material with a small thickness and a long material with a large thickness in the width direction.

However, this web member has the disadvantage that it requires a great deal of effort to manufacture.

The present invention has been made in view of the conventional drawbacks mentioned in 1.
Easily manufactured by using a differential thickness metal plate as a web member, which is made of a single long piece of material and has a difference in plate thickness in the cross section in the width direction by rolling so that the plate thickness near the neutral plane is thinner. The object of the present invention is to provide a type structural member having a welded structure that makes it possible to do this. Furthermore, a release agent made of a substance with a higher melting point than the heating temperature during rolling is inserted between multiple slabs of rolled material having different thicknesses so that the thickness is approximately uniform, and each slab is stacked on top of the other. After heating and rolling the material to have a uniform overall thickness, the stacked rolled materials are peeled off and the obtained differential pressure metal plate is appropriately cut and used as the above-mentioned web member. Therefore, it is an object of the present invention to provide a method for manufacturing a mold structure member having a welded structure, which allows the mold structure member having a welded structure to be manufactured easily, stably, and with high dimensional accuracy.

Next, the present invention will be explained with reference to the drawings, which are one embodiment.

FIG. 1a shows a type structural member 1a having an I-type welded structure according to the first invention, and the thickness difference in the cross section in the width direction is caused by rolling so that the thickness decreases linearly toward the neutral plane 2. A flange member 4a is welded to both upper and lower ends of a web member 3a made of a steel plate of different thickness. This mold structural member 1a
And, as shown in Fig. 1a7, a flange member 4 is attached to the web member 3a using a flat steel plate instead of the above-mentioned differential thickness steel plate.
In order to compare the moment of inertia and weight of the type structural member i a / formed by welding a, the 11th l la'
In the figure, the values of the symbol display part, the density ρ3, and the member length La are as follows.

Ha=1000, Ba=450, L1=30.1
2=22, L3=14, L4=20, La=80
00 (unit: mm), ρa = 7.8 x 1O-9
ton/7.

At this time, the moment of inertia (2) and weight W of the mold structure members 1 a and la' are as follows.

1 (mm4) W (ton) type structural member
1a 7.74x109 2.74"
la' 7.74x109 2.86 Therefore, the mold structure member 1a according to the present invention has a weight reduction of about 4% while maintaining the second moment of area equivalent to that of the mold structure member 1 a / using ordinary members. It can be reduced.

Next, FIG. 1b shows another embodiment of the first invention, in which a web is made of a differential pressure steel plate whose cross section in the width direction near the neutral plane is pressed down into a trapezoidal shape by rolling to provide a difference in plate thickness in the cross section. Part 3
The mold structure member 1b is formed into a box shape by arranging two pieces of flange members 4b facing each other and welding flange members 4b to the top and bottom of the flange members 4b. As above, this type structural member 1b and a web member 3b using a flat steel plate instead of the differential thickness steel plate as shown in FIG. 1b'.
A mold structure member 1b' formed by welding a flange member 4b to '
In order to compare the values, the values of the symbol display part, the density ρb, and the member length Lb in FIGS. 1b and 1b' are as follows.

rIb=2800,) IS=1350, B1)=
1500, t5=75, t6=54, t7=30
, L8=50, Lb=15000 (unit: mm
), Pb=7.8X10-9[On/-0 At this time, the second moment of inertia l-I and weight W of the mold structure members 1b and 1b' are as follows.

1 (mm4) W (ton) Type structural member 1b 1.55×1011 52・2・□
1b', 1.55xlO" 57.3 Therefore, the weight of the mold structure member 1b can be reduced by about 9% while maintaining the same moment of inertia of the mold structure as the mold structure member 1b'.

Note that the present invention is not limited to the above-mentioned embodiments, and instead of the web members 3a and 3b described in 1.
Web members 3c to 3 layers shown in FIG. , may be L-shaped.

Next, a second invention, which is an example of a method for manufacturing a mold structure member having the welded structure, will be described.

First, a method for manufacturing the mold structural member 1a will be described.

As shown in Fig. 4a, steel slabs 5al, 51 are rolled materials having thickness differences in a zigzag pattern in the opposite direction of the unevenness with an inclination angle equal to the longitudinal direction of the rolling direction (horizontal direction in Fig. 4a).
A release agent made of a material having a melting point higher than the heating temperature during rolling, such as powdered alumina, is inserted between the slabs 5a and 2 so as to have a substantially uniform thickness, and the slabs 5al and 5a2 are overlapped. Further, the boundary between the two slabs 5al and 5a2 is welded over the entire circumference to form a multilayer slab 63 having a uniform overall thickness.

Next, this multilayer slab 6a is heated and hot rolled, and then the welded portion is cut off. As a result, each rolled material (here, the material rolled from the slabs 5al and 5a2) can be easily peeled off, and a differential pressure steel plate 7a is obtained, and this differential pressure steel plate 7a is further cut in the winter mountain area. By doing so, a web section 3a is obtained.

Then, flange members 4a made of flat steel plates are welded to both ends of this web member 3a in the plate width direction (horizontal direction in Fig. 5a) to form a ■-shaped structural member 1a (see Fig. 1a). .

Similarly, FIG. 4b shows a multilayer slab 6b for the web member 3b of the mold structure member 1b, in which a slab 5bl has a convex portion near the neutral plane and a slab 5 has a concave portion in the cross section in the plate width direction.
After overlapping with b2 through a release agent inserted to a uniform thickness, both slabs 5bl.

It is formed by welding the boundary part of 5b2.

This multilayer slab 6b is heated, rolled, and the rolled material is peeled off in the same manner as described in 1 above to obtain a web member 31], and two web members 3b are placed opposite each other to form a rectangular cross section. Two flange members 4b made of flat steel plates
By welding these to both sides of the web member 3b, a box-shaped mold structure Ulb (see FIG. 1b) is obtained.

In the above example, after hot rolling the multilayer slabs 5a and 5b, each rolled material was peeled off, but depending on the application, cold rolling may be continued after hot rolling, and then each rolled material may be peeled off. It may be peeled off.

From the explanation below, according to the first invention, the material is made of a single long material and has a thickness difference in the cross section in the width direction by rolling so that the thickness near the neutral plane is thinner. A thick metal plate is used as the web member. Therefore, it becomes easy to manufacture a mold structure member having a welded structure.

Furthermore, since the web member is made of a single member, problems such as welding defects are eliminated, and quality control is simplified.

Furthermore, according to the second invention, a release agent made of a substance having a melting point higher than the heating temperature during rolling is inserted between the plurality of slabs, which are rolled materials having different thicknesses, so that the thickness is approximately uniform. Then, the slabs were stacked on top of each other to have a substantially uniform overall thickness, heated and rolled, and the differential pressure metal plates obtained by peeling off each rolled material were appropriately cut to form the above-mentioned web member. I am using it.

Therefore, a mold structure member having a welded structure can be manufactured easily, stably, and with high dimensional accuracy.

As a result, according to the first invention and the second invention,
It becomes easier to use welded type structural members, and it is possible to reduce the weight without reducing strength, especially in large buildings such as bridges and high-rise buildings, which is preferable from a structural standpoint and helps reduce construction costs. It also has the effect of contributing to

[Brief explanation of the drawing]

Figures 1a and 1b are sectional views of a mold structure member of a welded structure according to the first invention, Figures 1a7 and 1b' are sectional views of a mold structure member of a conventional welded structure, and Figures 2a to 2a. Figure 2g is a sectional view of the web member applied to the first invention, Figures 3a to 3.
Figure C is a sectional view showing another embodiment of the first invention; Figure 4a;
FIG. 4b is a sectional view of the multilayer slab according to the second invention, and FIG.
The figure is a sectional view of the differential pressure steel plate, and FIGS. 6a and 6b are sectional views of the web member used in FIGS. 1a and 1b. la, ~1e... type structural member, 2... neutral plane, 3a
. ~3g...web member, 4a, 4b...flange member, 5al, 5a2.5bl, 51) 2.7. Love, 6a, 6b...Multilayer slab. Procedural amendment written form) March 18, 1980 Patent Office Director Palace 1 Display of case 1983 Patent Application No. 183422 2 Name of invention Welded structure type structural member and manufacturing method 3 Person making amendment Case and Relationship: Patent applicant 4, agent corrects 2. (b) In line 11 of page 4 and line 15 of the same page, "Figure 1a" is corrected to "Figure 1b." (b) Page 5, line 10, page 8, line 19, page 8, line 1
In lines 6 to 17, “Figure 1b-1 and net,
``Corrected to ``Figure 1C-1, Amako.'' (c) In page 5, line 16, and line 19 of the same page, ``Figure 1b'' was corrected to ``Figure 1d.'' (2) The “Brief explanation of drawings” column of the specification will be corrected as follows. (b) Page 10, line 8, 1 - Correct the text "J" in Figure 1a to "Figure 1b." (b) Page 10, line 7, page 14, line 1b “Figure 1b”
(C) On page 10, line 8, ``Figure 1b'' has been replaced with ``Figure 1.
"Figure d" with a correction. (3) Figures 1a', 1b, and 1b' have been deleted, and Figures 1b, 1C, and 1d have been added in place of them. that's all

Claims (2)

[Claims] (1) A web member is a metal plate with a different thickness, which is made of a single long material and has a difference in thickness in the cross section in the width direction by rolling so that the thickness near the neutral plane is reduced. A type structural member having a welded structure, characterized in that it is formed by welding a flange member to the flange member. (2) A release agent made of a substance with a higher melting point than the heating temperature during rolling is inserted between multiple slabs of rolled material with different thicknesses so that the thickness is approximately uniform, and each slab is stacked. After heating and rolling the sheets, which were formed to have a substantially uniform overall thickness, the differential pressure metal plates obtained by peeling off the stacked rolled materials were appropriately cut to form a sheet near the neutral plane. 1. A method for manufacturing a mold structure member having a welded structure, characterized in that the mold structure member is manufactured by forming a web member having a thin plate thickness, and welding a flange member to this web member.