Spiral steel, application product of same, and method for manufacturing spiral steel

Abstract

The purpose of the invention is to provide a spiral steel having a high mechanical strength and being capable of easily narrowing the pitch interval of a twisted portion (spiral blade portion) even without changing a twist angle and also to provide an application product of the spiral steel and a method for manufacturing the spiral steel. The spiral steel is formed in such a way that steels (f1 to f4) having, as a center axis, an axis parallel with the longitudinal direction of the steels and having a shape including at least three or more long side members disposed radially with respect to the center axis are twisted along the center axis.

Description

technical field [0001] The present invention relates to a helical steel formed by twisting a steel material of a specific shape, an applied product thereof, and a manufacturing method of the helical steel. Background technique [0002] Conventionally, twisted flat bars made by twisting flat bars are used. The applicant has proposed and practically applied various utilization methods of twisted flat steel. [0003] As specific examples, there are a pile for driving into the soil shown in Patent Document 1, a pillar in which rigidity is ensured by joining a steel pipe to a twisted flat steel shown in Patent Document 2, and an anti-floating structure shown in Patent Document 3. Anchors (tent nails), etc. These piles and the like can be easily installed by punching, and can also be easily removed by pulling out while turning. [0004] As another application of the twisted flat steel, as shown in Patent Document 4, it can be used as a drill of a hole digger, or as a conveying ...

AI Technical Summary

Problems solved by technology

However, for the compressive force from the long-axis direction of the twisted flat steel, by figure 1 Bending load applied in the vertical direction, for example, easily deforms at the position indicated by the arrow, and cannot obtain sufficient mechanical strength

[0007] Therefore, it is difficult to use the twisted flat steel itself for the pillars of the structure, and if it is desired to increase the mechanical strength, it requires corresponding secondary processing, etc., which will have a negative impact on the difficulty and efficiency of processing.

In addition, twisted flat steel may be difficult to process in the direction of shortening the pitch of the flat steel, or longitudinal warp may occur.

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