JP3380396B2 - Wire material with indentation indentation - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear material with an indented impression used as a deformed bar.
The linear material in the present invention refers to steel rods, steel wires, and coil reinforcing bars in general.

[0002]

2. Description of the Related Art Generally, for reinforcing concrete, straight reinforcing bars are arranged vertically and horizontally in a mesh shape and welded at the intersections to be used on the floor or wall of a building, or the mesh shape is bent. However, there is an application used as the above-mentioned building member. This is a so-called welded wire netting in which a reinforcing bar is straightened and welded at a factory before going to a construction site in order to save labor and reduce the weight of a building material when using the reinforcing bar for a building. This is a field in which the construction period of welding wire mesh for concrete reinforcement has been shortened, streamlined, and standardized successfully. In order to quickly construct this welded wire mesh, there is no dimensional error, rising or welding separation.

The wire material with an indented indentation used as a deformed reinforcing bar for welding in the net shape of reinforcing bar processing for this purpose and on-site construction is to be straight at the time of the straightening machine in the factory, that is, linear processing And weldability are important. If this condition is not met, lifting or welding separation will occur on a certain plane, and the meaning of concrete reinforcement as a reinforcing bar will be impaired. Further, if the straightening is not straightened at the time of the straightening machine, the linear body is caught when it is supplied to the welding machine in the next step, and the so-called transportability is impaired.

For example, in Japanese Patent Publication No. 59-673, for the purpose of improving concrete adhesion, the height of the vertical ribs is 1.0 to 2.0 mm, the pitch p of the horizontal ribs and the height h of the horizontal ribs. Is 3 ≦ p / h ≦ 11, and the relationship between the nominal diameter D _N of the steel rod and the pitch p of the lateral ribs is 1.4√ (h /
Disclosed is a deformed steel bar for concrete reinforcement, wherein D _N ) ≦ p / D _N ≦ 2.5√ (h / D _N ).

Further, in Japanese Unexamined Patent Publication No. 6-31368, as a method for indenting a linear material, a plurality of indent rolls 1a, 1b, 1c and 1d are used to surround the linear material in a circumferential direction Y and a length direction X. A plurality of indentation rows a1, b1, c1 and d1 are provided by placing an indentation at intervals of, and the indentation of each indentation row is rotated clockwise of the linear member, facing side,
Disclosed is a method in which the phase is shifted in the order of counterclockwise and facing side, or in the order of counterclockwise, facing side, rightward and facing side and in the length direction of the linear member, and indentation is sequentially performed.

[0006]

In producing the indented linear material with indentations, it is generally produced by hot rolling in view of standard mass production. Usually produced by hot-indent rolling, in which the material is pressed into an elliptical cross-section during hot working by passing it between a pair of finishing rolls having calibers with convexities opposite to the indented shape. To do.

According to the present invention, for reinforcing concrete, in a process of welding straight reinforcing bars vertically and horizontally in a mesh shape,
An object of the present invention is to provide an indented linear material with an indentation which is roll-formed by the above-described method and which is straightened when processed by a straightening machine and has good weldability.

[0008]

The gist of the present invention is as follows. (1) In a linear material having a concave surface with a substantially constant interval and a substantially constant depth and a substantially constant area, the concave area is 20 to 80% of the total surface area , and the concave surface is elliptical.
At the same time, the indented linear material having an indented shape is characterized in that the outer surface is substantially circular . (2) indented shape indentations with linear material according to claim 1, wherein the oval recess surface is characterized in that it is skewed in the same direction about the axis.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION When straightening a linear material 1 used as a deformed reinforcing bar by the piece type straightening machine of FIG. 3, if the straightening is not straight, the linear material is supplied to a welding machine in the next step. At that time, it will be caught or a positional deviation will occur after welding, and floating or welding will occur.

As a result of earnest studies on the above points, the inventors of the present invention have shown that the outer surface has a shape close to a circle as shown in FIG. 1, and the concave surface 4 is in the same direction in the direction of the axis 5 at an angle θ. It has been found that the linearity is improved by forming a slanted elliptical shape, reducing the area of the recessed surface and increasing the area of the outer surface, that is, a so-called indented linear material with indentations.

The reason why this linearity is excellent is that the straightening piece has a small resistance and uniformly hits the entire surface.
It was found that the area of the recessed surface was the best in the range of 20 to 80% in consideration of linearity and concrete adhesion, as shown in FIG. Further, it has been found that the large area of the outer surface increases the contact area between the vertical bar 7 and the horizontal bar 8 in the welding machine 9 of FIG. 4, thereby improving the shear strength of the welded portion.

Therefore, the inventors of the present invention used the linear material having the shape of the present invention shown in FIG. 1 and the linear material having the conventional shape shown in FIG. 2 with a piece type straightening machine shown in FIG. I went. The result is shown in FIG. As shown in FIG. 5, it is understood that the linear material having the shape of the present invention has a smaller bending amount S per measured length 1 and has better linearity than the linear material having the conventional shape.

The so-called partial contact, in which the straightening piece 2 of the straightening machine of FIG. 3 comes into contact with a part of the node 11 or the axially extending rib 12 on the outer surface of the conventional linear material shown in FIG. On the other hand, since the linear material having the shape of the present invention has a substantially circular outer surface and a large area, the correction piece makes a light and even contact with the entire outer surface, so-called straightening area is large, so the linear material becomes straight. Of.

The linear material having the shape of the present invention can be easily subjected to so-called hot rolling by passing it between a pair of finishing rolls having a roll-hole type caliber in a general two-roll rolling method, so-called hot rolling. It can be manufactured.

[0015]

【Example】

(Example 1) The linear material having the shape of the present invention shown in FIG. 1 and the linear material having the conventional shape shown in FIG. 2 were straightened by a piece type straightening machine shown in FIG. The result is shown in FIG. It was evaluated that the smaller the bending amount S per measurement length l, the better the linearity, and the shape of the present invention was found to be better than the conventional shape.

Next, the linear material having the shape of the present invention shown in FIG.
A conventional linear wire having the above-mentioned shape was welded with a vertical bar and a horizontal bar by a welding machine shown in FIG. 4, and a test was carried out by a welded portion shear strength test method defined in JIS G3551 of FIG. The results are shown in FIGS. 7 (a) and 7 (b). It was shown that the larger the numerical value of the weld shear strength, the higher the strength, and it was found that the shape of the present invention is better than the conventional shape.

Further, the bending of the linear material was evaluated by the 90-degree bending test method as shown in FIG. The result is shown in FIG. It is shown that the closer to the target of 90 degrees, the better, and the shape of the present invention (FIG. 9B) is the same as the conventional shape (FIG. 9B).
It was found to be better than (a)).

Furthermore, the linear material embedded by the concrete curing method defined in JIS A1132 by the concrete adhesion strength test method shown in FIG.
FIG. 11B shows the relationship between the slip amount Δl and the pull-out load G when pulling out by the method specified in IS B 7721.
Shown in. As a result, it was found that the shape of the present invention was comparable to the conventional shape.

Incidentally, FIG. 13 shows the relationship between the slip amount Δl and the pull-out load G, that is, the so-called concrete adhesion property. It is explained that the maximum pull-out load G is reached through the elastic region, the elasto-plastic region and the plastic region. is doing.

A floor slab as shown in FIG. 10 is obtained by straightening the linear material having the shape of the present invention with the piece type straightening machine of FIG. 3 and welding the vertical and horizontal lines by the welding machine of FIG. Arrangement was carried out. As a result, the work required for constructing the entire floor, which has been conventionally required, does not require additional work such as uplifting and reinforcement of welding points, and the working time has been shortened.

Further, as shown in FIG. 12 (a), a welded wire mesh is embedded in concrete by the method specified in JIS A 5305, that is, in the state of a so-called concrete product, in the L direction and the C direction of FIG. The fracture strength when bent as in b) was investigated. The results are shown in Table 1.
As a result, it was found that the shape of the present invention was comparable to the conventional shape.

[0022]

[Table 1]

(Embodiment 2) As a result of comparing the linearity after straightening with the piece straightening machine of FIG. 3 when the area ratio of the concave surface of the linear material of the present invention of FIG. 1 is changed. Is shown in Table 2. Further, as shown in FIG. 14, the relationship between the area ratio of the concave surface and the average adhesive stress is shown. As a result, in the range of good linearity and concrete adhesion, the area ratio of the concave surface is 20 to 80%.
Was found to be within the range specified in the present invention.

[0024]

[Table 2]

[0025]

The linear material according to the present invention is straightened by the straightening machine, and the following improvements are achieved. (1) The straightening piece of the straightening machine is evenly worn and has good linearity, so the contact with the linear material can be loosened, the degree of wear is small, the replacement cycle is long, and the cost is improved. (2) Trouble caught on the straightening machine was reduced, and productivity was improved. (3) The scale peeling during the straightening process was improved, and the weldability in the next step was improved. (4) The supply troubles of the vertical and horizontal lines to the welding machine were drastically reduced, and the productivity was improved. In addition, it was possible to operate as if it were an unmanned operation, and we could expect a reduction in personnel. (5) Since the contact area between the welding electrode of the welding machine and the linear member is large, welding can be performed in a short time, wear of the welding electrode is reduced, the life is extended, and cost is improved. (6) The shear strength of the welded portion is improved, and the design strength is improved. (7) The arrangement of vertical stripes and horizontal stripes becomes square or rectangular,
Since there is no uplift, the floor slab reinforcement work can be easily constructed, and the construction period can be shortened. (8) Since it has good bending workability, it can be bent at a target angle, and can be reinforced in the center of a frame such as a U-shaped gutter, so improvement in the strength of concrete products can be expected. As a result, in reinforcing steel bars for concrete structures such as welded wire nets, it makes a great industrial contribution in production and use.

[Brief description of drawings]

FIG. 1 is a front view, a plan view, an AA cross-sectional view and a side view showing a shape example of a linear member of the present invention.

FIG. 2 is a front view, a plan view, showing an example of the shape of a conventional linear member,
AA sectional drawing and a side view.

FIG. 3 is an overall view showing an example of straightening processing by a piece type straightening machine and an enlarged view of a correction piece.

FIG. 4 is a schematic explanatory view showing an example of manufacturing a welded wire net with a welding machine.

FIG. 5 is a diagram showing a comparison of linearity between the conventional shape and the shape of the present invention after straightening.

FIG. 6 is an explanatory view of a welded portion shear strength test method.

FIG. 7 is a chart showing a comparison of the shear strength of the welded portion between the conventional shape and the shape of the present invention.

FIG. 8 is an explanatory diagram of a bending test method.

FIG. 9 is a chart showing a comparison of bending angles of the conventional shape and the shape of the present invention.

FIG. 10 is an explanatory diagram of an example of a floor slab bar arrangement diagram.

FIG. 11 is an explanatory diagram of a concrete adhesion strength test method.

FIG. 12 is an explanatory diagram of a concrete product bending test method.

FIG. 13 is a chart showing concrete adhesion characteristics.

FIG. 14 is a chart showing the relationship between the area ratio of recessed surfaces and the average adhesive stress.

[Explanation of symbols]

1 linear material 2 straightening pieces 3 feed rollers 4 recessed surface 5 axis 6 gap zone θ Angle between the concave surface and the axis in the linear material of the present invention 7 Vertical streaks 8 horizontal lines 9 welding machine 11 Nodes (convex) of conventional wire 12-section gap band (rib) 13 axis 14 Recessed surface θ Angle between the concave surface and the axis in the linear material of the present invention α Angle between node and axis in conventional linear material

Continuation of the front page (72) Tomio Sakano Tomio Sakano 1-2-7 Kakinokizaka, Meguro-ku, Tokyo Within Sakano Kogyo Co., Ltd. (56) Reference JP-A-8-284313 (JP, A) JP-A-9-94602 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) B21H 8/00 B21F 1/02 E04C 5/03

Claims (2)

(57) [Claims] 1. A substantially constant interval and a substantially constant depth,
And in a linear material having a recessed surface with a substantially constant area,
The area of the dent is 20-80% of the total surface area , and the dent surface is oval
An indented linear material having an indented shape , which has a substantially circular shape on the outer surface . 2. A indented shaped indentations with linear material according to claim 1, wherein the oval recess surface is characterized in that it is skewed in the same direction about the axis.