JPH06288038A - Coil rebar having excellent bending workability and method for manufacturing the same - Google Patents

Abstract

(57) [Summary] [Object] To provide a coil rebar having excellent bending workability in rectangular or continuous circular bending, and a method for manufacturing the same. [Structure] There is a node that is inclined in the same direction with respect to the axis and is arranged at regular intervals, and the node is formed by two spirally extending nodes that are symmetrical with respect to the axis and a gap band between the nodes. It's broken,
A coil rebar having excellent bending workability and a method of manufacturing the same, wherein the skew is inclined with respect to an axis line opposite to the gap band.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coil rebar having excellent bending workability and a method for manufacturing the same.

[0002]

2. Description of the Related Art Generally, a coil rebar wound in a coil shape is used for reinforcing concrete. The coil rebar is bent into a rectangular shape or a circular shape when it is carried out. The condition of workability is that the bent rebar is regularly bent within a certain cross section.

For example, in Japanese Examined Patent Publication No. 52-21295, there is no directionality in the moment required for bending a deformed wire, bending in any direction is easy, and good straightness can be obtained by mechanical correction. Further, a steel rod / wire for concrete reinforcement in which wear of the straightening device is small is disclosed. or,
Deformed wire rods have different shapes depending on the shape of the knot, for example
Bamboo knots (a), wave knots (b), cross knots (c), etc. are known, but there are many other knot shapes such as leaf knots.

[0004]

Generally, when a rebar shape is formed by hot rolling, the surface of the hot rolled material is composed of nodes and gaps between the nodes. In consideration of the productivity of the wire rod rolling of the coil reinforcing bar, when the normal laying winding is performed, 360 ° / ring twist occurs as a result.
If there is a twist in the direction of rebar movement, even if bending is performed in the same direction, the twist changes the positional relationship between the nodes and the gap between the nodes in the longitudinal direction, and as a result, there is a difference in the section modulus. Occurs and bending workability deteriorates.

That is, the bending occurs in a direction in which the bending moment becomes smaller in the cross section, and therefore the bending direction of the bent coil rebar becomes uneven. Uplift occurs due to non-uniformity, and as a result it becomes difficult to apply it to buildings. If the shape of the coil rebar is a simple knotless circular shape, the unevenness of the bending moment can be eliminated, but it becomes difficult to secure the adhesion of concrete. The present invention provides a coil rebar having excellent bending workability in rectangular or continuous circular bending and a method for manufacturing the same.

[0006]

The gist of the present invention is as follows. (1) It has a node 5 that is skewed in the same direction with respect to the axis and is arranged at regular intervals, and the node 5 has two spirally extending nodes that are symmetrical with respect to the axis and a gap between the nodes. A coil rebar excellent in bending workability, characterized in that it is interrupted by a band 6 and that the oblique line is inclined with respect to an axis line opposite to the gap band 6. (2) The twist angle α of the gap band 6 between the nodes is 75 in the axial direction.
The coil rebar having excellent bending workability according to (1), wherein the coil rebar has an angle of up to 120 ° / m and an oblique angle θ of 45 to 60 ° with respect to the axis of the joint 5.

(3) After the material is hot-rolled to form a knot shape oblique to the rolling direction, a twist that intersects an inclined node with respect to the rolling direction is continuously wound on the non-concentric ring. A method for manufacturing a coil rebar characterized by applying. (4) With respect to the knot shape in which the angle between the node and the axis line is 45 to 60 ° in the clockwise direction with respect to the rolling direction, the twist angle per unit length is 75 to 120 ° / m in the counterclockwise direction. Twisting when winding a non-concentric ring (3)
A method for manufacturing a coil rebar as described. (5) For a knot shape in which the angle between the knot and the axis is 45 to 60 ° counterclockwise with respect to the rolling direction, the twist angle per unit length is 75 to 120 ° / m in the clockwise direction. (3) The method for manufacturing a coil rebar according to (3), wherein a twist is imparted when winding the non-concentric ring.

[0008]

In the coil rebar, the inclination angle of the knot and the twisting direction have a great influence on the longitudinal direction of the bending moment in bending. In the present invention, since the inclination angle of the node and the twist direction of the gap (hereinafter referred to as a rib) of the node intersect each other, the floating amount is reduced and the workability is excellent. Figure 1
It is a conceptual explanatory drawing of the coil reinforcement 1 of this invention. In the figure, 2: axis line, 3: axis direction, 4: angle between axis line and node,
5: node, 6: rib is shown.

The twist angle α of the node and rib in the present invention
Is 75 to 120 ° / m. Here, the twist angle is shown in FIG.
Indicates the angle α in the coil rebar 1. Twist angle 75
~ 120 ° / m means that the ring diameter of the laying head in the wire rod production line is generally 1.0 to 1.5 m.
Since it is a degree, the idea of the present invention can be applied to other ring diameters.

The angle between the node and the axis is in the range of 45 to 60 degrees clockwise or counterclockwise with respect to the traveling direction of the axis. If it is less than 45 °, the bending workability becomes uneven during bending, and if it exceeds 60 °, the adhesion of concrete decreases, and it becomes difficult to secure the JIS tolerance as a reinforcing bar.

The coil rebar of the present invention is formed of a node oblique to the axis and a rib that twists. That is, FIG. 2 corresponds to FIG.
Is a partially developed view of the rib 6, the twist angle α of the rib 6 is 75 to 120 ° per 1 m when 360 ° per rotation.
Further, as shown in FIG. 3, the oblique node 5 has an angle θ with respect to the axis.
Is 45 to 60 °, both the adhesion and workability of concrete are excellent.

The coil rebar of the present invention has a general roll groove shape and a general oblique knot shape, and is easy to roll and is low in cost. Further, the twisting of the reinforcing bar can be easily formed on the wire rod manufacturing line having the ray reeler. That is, in the coil reinforcing bar, the knot inclination angle and the twisting direction have a great influence on the bending moment in the longitudinal direction during bending.

In the present invention, the material is knotted by hot rolling, and then the inclination angle and the twisting direction are made to intersect with each other. The relationship between the twisting angle and the ring diameter of the laying head is obtained in advance, The laying head can be selected to obtain a given twist angle.

[0014]

【Example】

(Embodiment 1) A coil rebar having a basic shape satisfying the regulation of JIS G3112 is processed by a continuous circular bending (300
φ) and size: D10 / D13 / D16 / D19. In hot rolling, after forming a node shape oblique to the rolling direction, the ring diameter was continuously set to 955 mm and 15
A 28 mm laying head was selected and twisted.

When a ring diameter of 955 mm is used, 120
° / m, 75 ° / when using a ring diameter of 1528 mm
A twist angle of m was formed. The results are shown in FIGS.
Shown in. The flying height was significantly reduced at a knot angle of 45 to 60 °. On the other hand, in FIG. 4-B, in the case of an oblique node having a knot angle of 45 ° clockwise with respect to the axis, the helix angle rises in the range of 75 to 120 ° counterclockwise with respect to the axis. The quantity has been greatly improved.

(Example 2) A coil rebar (size: D13) having a basic shape of steel type SD295A satisfying the requirements of JIS G3112 was manufactured. In hot rolling, after forming a node shape oblique to the rolling direction, a laying head having a ring diameter shown in Table 1 was continuously selected and twisted. The results are shown in Table 1.

[0017]

[Table 1]

Comparative Example No. The twist angle of −95 ° of 6 is an example in which the rib direction is the same as the diagonal node. The flying height of the present invention was superior to that of the comparative example.

FIG. 6 (a) is a photograph showing the flying height of the comparative example during rectangular processing, and FIG. 6 (b) is a photograph showing the flying height of the present invention during rectangular processing. The flying height of the coil rebar according to the present invention is very small. Is. FIG. 7 is a photograph of another example of the present invention, in which the bending angle in the plane direction was constant and there was no tangle.

[0020]

EFFECTS OF THE INVENTION According to the present invention, in a coil rebar in which it is difficult to avoid twisting during manufacturing, complicated roll groove processing is unnecessary, and a coil having good bending workability such as rectangular or continuous circular bending. The shape of the reinforcing bar can be secured. As a result, it is possible to efficiently produce reinforcing bars with good bending workability such as rectangular and continuous circular bending in auxiliary reinforcing bars for concrete structures such as columns in various buildings, which contributes to a significant cost reduction. Will result.

[Brief description of drawings]

FIG. 1 is a conceptual explanatory diagram of the present invention.

FIG. 2 is an analysis diagram of the present invention.

FIG. 3 is another analysis diagram of the present invention.

4A is a diagram showing a relationship between a node angle with respect to an axis and a flying height, and FIG. 4B is a chart showing a relationship between a twist angle with respect to an axis and a flying height.

5 (a), (b) and (c) are explanatory views of a conventional example.

6A is a photograph of the flying height of a conventional product, and FIG. 6B is a photograph of the flying height of the present invention.

FIG. 7 is a photograph of the packaging of the present invention.

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[Procedure amendment]

[Submission date] November 19, 1993

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 6

[Correction method] Change

[Correction content]

[Figure 6]

[Procedure Amendment 2]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 7

[Correction method] Change

[Correction content]

[Figure 7] ─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] January 7, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Figure 6

[Correction method] Change

[Correction content]

FIG. 6A is a perspective view showing a floating amount of a conventional product,
(B) is a perspective view showing the floating amount of the present invention.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] Figure 7

[Correction method] Change

[Correction content]

FIG. 7 is a perspective view of the present invention during packaging.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Takashi Ueno 12 Nakamachi, Muroran City, Muroran City, Muroran Steel Co., Ltd. (72) Inventor Isesaki, 12 Ho, Nakamachi, Muroran City, Muroran City, Japan Orchid Works (72) Inventor Wataru Nozaki 12 Nakamachi, Muroran City Nippon Steel Corporation Muroran Works

Claims (5)

[Claims] 1. A node 5 obliquely extending in the same direction with respect to the axis and arranged at regular intervals, the node 5 being two spiral nodes and a node symmetrical with respect to the axis. The coil rebar excellent in bending workability, characterized in that it is interrupted by the gap band 6 and the oblique line is inclined with respect to the axis opposite to the gap band 6. 2. The twist angle α in the axial direction of the joint band 6 between the nodes is 75 to 120 ° / m, and the skew angle θ with respect to the axis of the node 5 is 45 to 60 °. The coil rebar having excellent bending workability according to claim 1. 3. The material is hot-rolled to form a knot shape oblique to the rolling direction, and then a twist intersecting an inclined node to the rolling direction is imparted at the time of winding the non-concentric ring. A method for manufacturing a coil reinforcing bar, comprising: 4. A knot shape in which the angle between the node and the axis is 45 to 60 ° in the clockwise direction with respect to the rolling direction, and a twist angle per unit length in the counterclockwise direction is 75 to 120 ° / The method for manufacturing a coil reinforcing bar according to claim 3, wherein a twist is imparted when winding the non-concentric ring so that the length becomes m. 5. A knot shape in which the angle between the knot and the axis is 45 to 60 ° in the counterclockwise direction with respect to the rolling direction,
The twist angle per unit length in the clockwise direction is 75 to 120 ° /
The method for manufacturing a coil reinforcing bar according to claim 3, wherein a twist is imparted when winding the non-concentric ring so that the length becomes m.