JP7340677B1 - Method for suppressing twisting of threaded reinforcing bars - Google Patents

Abstract

[Problem] Even in the case of products whose properties are not uniform over the entire length (tip, middle, and rear end), by applying uniform deformation from the side, it is possible to produce threaded reinforcing bars that are free from twisting over the entire length. To provide a twist suppression method. [Solution] By plastically deforming a threaded joint reinforcing bar R in which a threaded joint S is formed with a threaded shape forming roll 2 using a pair of rolls installed on the downstream side of a threaded shape forming rolling mill, This is to correct the twist that occurs in the threaded reinforcing bar R, and the pair of rolls is a convex roll 3 with an arcuate cross-sectional shape, and the threaded knots S of the threaded reinforcing bar R are formed. The twist that occurs in the threaded reinforcing bar R is corrected by rolling down the parts where it is not present from both sides and applying plastic working to the center of the threaded reinforcing bar R. [Selection diagram] Figure 3

Description

The present invention suppresses twisting that occurs in threaded reinforcing bars when manufacturing threaded reinforcing bars (deformed steel bars with threaded knots. In this specification, referred to as "threaded reinforcing bars"). The present invention relates to a method for suppressing twisting of threaded reinforcing bars by improving the shape of the reinforcing bars.

By the way, when manufacturing threaded reinforcing bars by rolling, threaded reinforcing bars tend to induce twisting due to the formation of thread-like knots in them, which reduces the shape accuracy of threaded reinforcing bars. There was a problem that the

As a countermeasure to this problem, that is, a method for suppressing the twisting that occurs in threaded reinforcing bars when manufacturing threaded reinforcing bars,
1. A method of offsetting the twist that occurs in threaded reinforcing bars by tilting the rolling entrance guide in the opposite direction in advance (see, for example, Patent Document 1).
2. A method of correcting twists occurring in threaded reinforcing bars by holding the threaded reinforcing bars using a roller guide at an exit stand (see, for example, Patent Document 2).
has been proposed and put into practical use.

However, the above-mentioned conventional method for suppressing twisting of threaded reinforcing bars is
1. The method of tilting the rolling entrance guide in the opposite direction in advance results in left-right asymmetric rolling, which reduces the accuracy of the shape of the shoulder thread.
2. The method of holding threaded reinforcing bars using a roller guide on an exit stand involves untwisting and correcting the reinforcing bars at two points in contact with the rollers of the roller guide, which prevents twisting for products whose properties are not uniform over the entire length (tip, middle, and rear end). remains uneven.
There was a problem.

Japanese Patent Application Publication No. 2001-150017 Japanese Patent Application Publication No. 2007-125597

In view of the above-mentioned problems with the conventional method for suppressing twisting of threaded reinforcing bars, the present invention has been developed by applying uniform deformation from the side, even in the case of products whose properties are not uniform over the entire length (tip, middle, and rear end). The purpose of the present invention is to provide a method for suppressing twisting of threaded reinforcing bars that can produce threaded reinforcing bars that are free from twisting over their entire length.

In order to achieve the above object, the method for suppressing twisting of a threaded reinforcing bar of the present invention includes installing a threaded reinforcing bar in which threaded knots are formed with a rolling roll for threaded shape forming on the downstream side of a rolling mill for threaded shape forming. In a method for suppressing twisting of threaded reinforcing bars in which twisting occurring in threaded reinforcing bars is corrected by plastically deforming them using a pair of rolls, convex rolls having an arcuate cross-sectional shape are used as the pair of rolls. However, the twist that occurs in the threaded reinforcing bars is corrected by compressing the parts of the threaded reinforcing bars where threaded knots are not formed from both sides and applying plastic working to the center of the threaded reinforcing bars. It is characterized by

In this case, a cross-sectional shape extending in the longitudinal direction of the reinforcing bar material is formed using a groove-forming rolling roll at a 180° symmetrical position on the circumferential surface of the reinforcing bar material before the thread-like nodes are formed using the thread-shape forming rolling roll. can form a concave groove having an arc shape.

According to the method for suppressing twisting of threaded reinforcing bars of the present invention, threaded reinforcing bars can be manufactured with a simple mechanism by improving the shape of a pair of convex rolls installed downstream of a rolling mill for thread shape forming. At the same time, it is possible to suppress twisting that occurs in the threaded reinforcing bars and improve the shape of the threaded reinforcing bars.

FIG. 2 is an explanatory diagram showing an example of a rolling process for carrying out the method for suppressing twisting of threaded reinforcing bars of the present invention. It is an explanatory view showing the main part of the same rolling process. It is an explanatory view showing the shape of the reinforcing bar in the rolling process of the same reinforcing bar.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the method for suppressing twisting of threaded reinforcing bars of the present invention will be described based on the drawings.

1 to 3 show an embodiment of the method for suppressing twisting of threaded reinforcing bars according to the present invention.
This method for suppressing twisting of threaded reinforcing bars is to use a pair of rolls installed downstream of a rolling mill for threaded shape forming to form threaded knotted reinforcing bars R into threaded knots S using a rolling roll 2 for threaded shape forming. Plastic working is used to correct the twist that occurs in the threaded reinforcing bars R. The pair of rolls is a convex roll 3 with an arcuate cross-sectional shape, and the threaded reinforcing bars R are straightened. The twist occurring in the threaded reinforcing bar R is corrected by rolling down the part where the knot S is not formed from both sides and applying plastic working to the center of the threaded reinforcing bar R.

Here, the thread-shaped rolling roll 2 is a rolling roll for forming thread-shaped nodes S in the reinforcing bar material R0.

Then, the roll roll 1 for forming a concave groove is arranged in the pre-process of the roll roll 2 for thread shape formation, and before the thread shape knot S is formed by the roll roll 2 for thread shape formation, the circumferential surface of the reinforcing bar material R0 is At 180° symmetrical positions, the groove forming roll 1 is used to form grooves H having an arcuate cross-sectional shape extending in the longitudinal direction of the reinforcing bar material R0.

The convex roll 3 has an arcuate cross-sectional shape, and the threaded joints S of the threaded reinforcing bar R are formed by the rolling roll 1 for forming grooves and the rolling roll 2 for forming a threaded shape. The arc-shaped convex part fits into the unformed part, that is, the concave groove H, and is rolled down from both sides, and plastic working is applied to the center of the threaded reinforcing bar R, thereby reducing the twist that occurs in the threaded reinforcing bar R. I am trying to correct this.

The threaded reinforcing bars R whose twist has been corrected by the convex rolls 3 are conveyed to a cooling bed (not shown) via the run-in rollers 4 and the braking plate 5.

This method for suppressing twisting of threaded reinforcing bars has the following effects.
1. When forming a thread-shaped node S with the rolling roll 2 for forming a thread shape, roll is performed symmetrically without tilting the inlet side in the opposite direction, making the shoulder dimensions uniform, and forming the thread-shaped node S. After forming, the convex roll 3 is used to roll down the part of the threaded reinforcing bar R where the threaded knot S is not formed, and plastic working is applied to the center of the threaded reinforcing bar R to form a thread. By correcting the twist that occurs in the knotted reinforcing bar R, the twist can be eliminated. In particular, it is possible to eliminate the strong twist that occurs when rolling under strong pressure so as to increase the thread height.
2. By forming concave grooves H extending in the longitudinal direction of the reinforcing bar material R0 at 180° symmetrical positions on the circumferential surface of the reinforcing bar material R0 with a concave groove forming rolling roll 1 having an arcuate cross-sectional shape, the convex roll 3 The center of the threaded reinforcing bar R can be guided stably.
3. Since the threaded reinforcing bar R comes into hot contact at two points of the tip of the arc of the convex roll 3 having an arcuate cross-sectional shape, roughness does not occur on the side surface of the threaded reinforcing bar R, and the surface quality is improved. Can be done.

The method for suppressing twisting of threaded reinforcing bars according to the present invention has been described above based on the embodiments thereof. However, the present invention is not limited to the configuration described in the above embodiments, and may be modified as appropriate without departing from the spirit thereof. Its configuration can be changed.

The method of suppressing twisting of threaded reinforcing bars of the present invention uses a simple mechanism by improving the shape of the roll that holds the threaded reinforcing bars at the exit stand. Since twisting can be suppressed and the shape of threaded reinforcing bars can be improved, it can be suitably used for manufacturing threaded reinforcing bars.

1 Rolling roll for forming grooves 2 Rolling roll for forming threaded shapes 3 Convex roll 4 Run-in roller 5 Braking plate H Groove R Threaded joint reinforcement R0 Reinforcing bar material S Threaded joint

Claims (1)

By plastically deforming the threaded reinforcing bars that have formed threaded knots using a rolling roll for forming threaded shapes using a pair of rolls installed downstream of the rolling mill for threaded shaping, the torsion that occurs in the threaded reinforcing bars can be reduced. In a method for suppressing twisting of threaded reinforcing bars to correct
As a pre-process to the process of forming thread-like knots with the thread-shape forming roll, a recess is formed at a 180° symmetrical position on the circumferential surface of the reinforcing bar material before forming the thread-like knot with the thread-shape forming roll. forming a concave groove with an arcuate cross-sectional shape extending in the longitudinal direction of the reinforcing bar material using a groove-forming roll;
As a post-process of forming thread-like knots with the thread-shape forming rolling rolls, a pair of rolls is a convex roll with an arc-shaped cross section, and the thread-like knots of the thread-knot reinforcing bar are This occurs in the threaded reinforcing bars by rolling down the unformed concave grooves with an arcuate cross-sectional shape from both sides using the convex parts of the convex rolls and applying plastic working to the center of the threaded reinforcing bars. and a step of correcting the twist.
A method for suppressing twisting of threaded reinforcing bars.

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