JPH0275431A - Working method for pc steel stranded wire rolled threads - Google Patents

Abstract

PURPOSE:To surely stabilize the stress of a PC steel stranded wire to anchor a nut in a small cost by working rolled threads on the PC steel stranded wire when the stress introduced is anchored by a nut in using the PC steel stranded wire for the prestressed concrete technique. CONSTITUTION:The PC steel stranded wire 1 wherein plural element wires 2 are stranded helically is cold-drawn and deformed plastically, the helical gap 3 among the element wires 2 are crushed and reduced, the outer surface 5 is formed in a circular shape, the bonding between the element wires 2 is intensified and deformation by external pressure is made difficult to occur. Rolled threads are cut by the forming roll 6 at the end part of this PC steel stranded wire 1a to form a desired length of rolled threads 7 at both ends. Or, a ring 8 is fitted to the end part of the PC steel stranded wire 1a which has been deformed plastically before threading, then, rolled threads are cut by the forming roll 6 to a specific length part except a ring 8, then, the ring 8 is cut off to manufacture a PC steel stranded wire capable of anchoring a nut.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a rolling process method for applying stress to a prestressed steel strand by fixing it with a nut after stress is introduced when the PC steel strand is used in a prestressed concrete construction method. It is.

(Prior art) There are various methods for fixing the stress after introducing stress when using conventional PC steel strands in prestressed concrete construction method, but all of them are horizontal methods using complicated fixing tools, and this method is not suitable for this purpose. It lacks reliability compared to the nut fixation of the invention. Furthermore, the cost and work time required for fixing increase significantly.

Therefore, conventionally, all PCA rods used in the PCA4 strand-like prestressed concrete method are anchored with nuts because it is easy to form threads, but rolling threads are not possible in the case of PCA strands. Because of this, there has been no establishment of Natsuto until today.

(Problems to be Solved by the Invention) Conventionally, the method of fixing the stress after introducing stress into the PC steel stranded wire used a complicated fixing device as described above, and all of the fixing devices were of the wedge force type. This is because in the case of a PC steel stranded wire, thread rolling cannot be easily performed as with a PC steel bar.

If the rolling process can be easily performed like pc@@, nuts can be easily and reliably fixed using only the anchor plate without using complicated fixing tools.

However, until now, it has been considered impossible to perform rolling thread processing on PCL4 stranded wire. The reason for this is P.
In the case of C steel stranded wire, since it is made of #l structure with twisted wires, there are spiral grooves between the wires, and when thread rolling is applied, a greater pressure is required than with PC steel. It has been considered impossible to form a threaded thread due to the force applied between the wire strands, which destroys the perfect circle between the strands.

In order to solve the above-mentioned problems, the present invention has been made through various experiments over many years, and has succeeded in applying thread rolling to PC steel strands.

(Means for solving the problems) P according to the present invention to solve the conventional problems as described above.
The feature of the rolling screw processing method for C steel stranded wire is that after processing the stranded PCL wire, which is made by twisting multiple strands of wire, plastic deformation is applied by cold drawing to form a spiral gap between the strands. and transform the outer surface into a cylindrical surface, and then perform a thread rolling process on the end of the wire in the same direction as the twisting direction of the 20g4 stranded wire, and twist multiple strands of wire. After stranding the PC steel wire, we give it plastic deformation through cold drawing to reduce the spiral gap between the strands, transform the outer surface into a cylindrical surface, and fit a ring around the end of the wire. After that, rolling thread cutting is performed at the position excluding the ring.

(Function) This method performs cold drawing after stranding in the PCM stranded wire manufacturing process to reduce the spiral gap between the strands, thereby making the bond between the strands stronger and forming a rolled thread. The pressurizing force applied at times prevents the wires from becoming out of perfect circle. Further, by making the stranded wire plate twisting direction and the rolling thread cutting rotation direction in the same direction, deformation of the perfect circle between the strands is prevented.

Furthermore, in the case of rolled screws where the roundness between the strands may be distorted depending on the size, or where greater precision is required, a hard ring is inserted at the tip of the thread rolling part to prevent the circularity between the strands from collapsing. 2 rolls are rolled from the position excluding the ring.

In this case, after thread rolling, PC from the position excluding the ring.
Nut anchoring is possible by cutting the steel strands.

Conventionally, nut fixing is the method for fixing stress after stress is introduced, and it is simpler and more reliable than any other fixing method, and it is also cheap and easy to fix, so in the case of thick PCfA rods, no other method other than nut fixing has been used. .

Therefore, even in the case of PC steel stranded wire, by using the method of the present invention, it is possible to fix the nut using only the anchor plate without using a complicated fixing device as in the past.

(Example) Next, embodiments of the present invention will be described with reference to the drawings.

Figure 1 shows a PCM that is thread-rolled using the method of the present invention.
A stranded wire 1 is shown, and this P(J14 stranded wire 1 has a plurality of strands 2 twisted together in a spiral shape).

In this PCS stranded wire 1, strands 2.2 having a circular cross section are in close contact with each other in a state close to line contact, and a large helical gap 3 exists between each contact portion.

Prior to thread rolling, wire 1 is cold drawn from prestressed steel. As shown in Fig. 2, this processing is performed by forcibly passing the wire 1 made of prestressed steel through a die 4 having a circular cross section with a diameter smaller than the outer diameter a of the prestressed steel wire 1, causing plastic deformation. As shown in FIG. 3, the helical gap 3 between the strands 2 is compressed to make it smaller, and the outer surface 5 is formed into a cylindrical shape. As a result, the bond between each strand 2 becomes strong, and the whole becomes difficult to deform due to external pressure.

Although this cold drawing process is performed over the entire length of the PCfA stranded wire 1, it may also be applied only to the ends where thread rolling is to be performed.
The ends of the cs stranded wire 1a are thread-rolled using rolling rolls 6.6.6 as shown in FIG. Shape.

In this thread rolling process, the deformed PC steel is rotated in the same direction as the helix of the wire 1a, so that when it is rotated under pressure between the rolling rolls 6, 6, 6, the stranded wire becomes A stronger force in the direction of twisting is applied, making it difficult for the strands 2 to collapse.

In addition, prior to the thread forming by the rolling roll, a ring 8 is fitted to the end of the wire 1a made of deformed PC steel which has been plastically deformed by cold drawing, as shown in FIG.
As shown in FIGS. 8 and 9, thread rolling is performed to a desired length at a position excluding the ring 8 portion using a rolling roll 6.6, and then the ring 8 portion is cut. As shown in FIG. 6, a rolling screw 7 may be formed at the end. By fitting the ring 8 in this manner and performing the thread rolling process, high precision thread processing can be obtained.

In this case, the direction of the screw does not have to be the same as the direction of twisting the PC steel strands.

(Effects of the Invention) As described above, the present invention realizes nut fixing, which has been desired as a PCS twisted line fixing method.

Therefore, when comparing the method using the conventional fixing device and the present invention, it is found that the method of the present invention, which makes it possible to fix nuts using only an anchor plate, significantly reduces fixing costs, etc., and also enables reliable fixing. This is an epoch-making invention as a method for fixing stranded steel wires, and its effects are extremely large.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of a PC steel stranded wire subjected to thread rolling according to the present invention, Figure 2 is a cross-sectional view of the cold drawing process, and Figure 3 is a cross-sectional view of a deformed PC steel stranded wire after cold drawing. A sectional view, FIG. 4 is a front view of the thread rolling process, FIG. 5 is a side view of the same, and FIG.
The figure is a plan view of the PC#l stranded wire after rolling, Figure 7 is a front view of the deformed PC#l stranded wire with a ring fitted, and Figure 8 is the deformed PC steel shown in Figure 7. FIG. 9 is a front view of the thread rolling process for the wire, and FIG. 9 is a side view of the same. 1...PC steel stranded wire, 2...Element wire, 3
...Spiral gap, 4...Dice, 5.
...Outer surface, 6... Rolling roll, 7...
...Rolled screw. Patent applicant North Sea! 11 Machine Co., Ltd.
Times Engineering Co., Ltd. Figure 1 Figure 2 Figure 3 Figure 7 Figure 1a Procedural amendment (voluntary) November 15, 1988

Claims (2)

[Claims] (1) A PC steel stranded wire made by twisting multiple strands is subjected to plastic deformation by cold drawing after stranding,
It is characterized by reducing the helical gap between the strands, transforming the outer surface into a cylindrical surface, and then applying a thread rolling process to the end of the wire in the same direction as the twisting direction of the wire from PC steel. A rolling thread processing method for PC steel stranded wire. (2) After stranding the PC steel stranded wire, which is made by twisting multiple strands together, plastic deformation is applied by cold drawing.
It is characterized by reducing the helical gap between the strands, transforming the outer surface into a cylindrical surface, fitting a ring around the outer circumference of the end, and then performing rolling thread cutting at the position excluding the ring. A rolling thread processing method for PC steel stranded wire.