JP2787288B2 - Method for manufacturing steel tensile material fixing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the manufacture of a steel tensile material anchoring device used for introducing a stress in a prestressed concrete structure, suspending a cable such as a bridge, and further using a steel tensile material for tensioning a retaining plate. About the method.

[0002]

2. Description of the Related Art Conventionally, in a prestressed concrete structure, a PC strand in which a plurality of steel strands are twisted has been used. However, in recent years, a reduction in proof stress due to the temporal corrosion of the PC strand has become a problem. In order to prevent this, PC strands having a rustproof coating made of a synthetic resin have been used. For example, a PC strand 6 shown in FIG. 11 has a single strand 7 (core wire) made of a PC steel wire as a center, and six single strands 7,
7. A strand is formed by spirally winding the (side wire), forming a rust-preventive coating 9 of a synthetic resin on the outer peripheral surface thereof, and filling the internal void between the single wires 7 with the synthetic resin. ing.

A fixing device for a PC strand having such a rust-preventive coating is disclosed in, for example, JP-A-6-27238.
No. 4 (wedge fixing). this is,
As shown in FIG. 12, the end of the PC tosland 6 is inserted into a tapered cylindrical through hole of the fixing member 3 which abuts on the support plate 5, and a blade-like ridge is fixed inside between the two. The fixing wedges 4 and 4 are inserted into the through holes of the fixing body 3 by the force in the return direction when the PC strands 6 are tensioned by inserting the fixing wedges 4 and 4 whose outer circumferences are half-tapered and cylindrical. Is made to bite into the outer periphery of the PC strand 6 to fix the PC strand 6.

On the other hand, as a fixing device for a PC strand having no rust preventive film, for example, Japanese Utility Model Publication No. Sho 53-28264.
As shown in FIG. 13, there is a crimped grip formed by forming a ridge on the outer periphery of the end of the PC strand 1 by rolling or the like, covering the steel sleeve 2 with the steel strand 2, as shown in FIG. Steel sleeve 2 by extrusion, drawing, etc. using a die
Is pressed from the outer peripheral side and is crimped to the outer periphery of the end of the PC strand 1.

[0005]

In the fixing device shown in FIG. 12, when the fixing wedges 4 and 4 are drawn into the through holes of the fixing member 3, the inner edge of the fixing wedges 4 and 4 have a PC-like edge. The rust-preventive coating 9 penetrates and penetrates the surface of the strand 6, but at this time, slippage occurs between the fixing wedges 4, 4 and the PC strand 6, and the rust-preventive coating 9 on the surface of the PC strand 6 is formed.
May be unnecessarily scraped off, and there is a problem that rust prevention performance is reduced.

On the other hand, when the fixing device shown in FIG. 13 is applied to a PC strand 6 having a rust-proof coating, if a synthetic resin is interposed between the steel sleeve 2 and the single strands 7, 7,. As a result, a sufficient pressure cannot be obtained, so that the rust preventive coating 9 at the portion where the steel sleeve 2 is pressed is previously shaved off, and there is a problem that the rust preventive performance decreases.

The present invention has been made in view of such a conventional problem,
An object of the present invention is to provide a steel tensile member fixing device capable of suitably fixing a steel tensile member without unnecessarily shaving off a rust-proof coating on the surface, and a method of manufacturing the same.

[0008]

SUMMARY OF THE INVENTION The features of the present invention for solving the conventional problems as described above and achieving the intended purpose are as follows.
Multiple steel strands are twisted together to fix a steel tensile material with a rust-proof coating made of synthetic resin on the surface.
In the method of manufacturing a dressing device, on the outer periphery of the steel tensile member,
A steel sleeve having an edge-shaped protrusion on the inner surface is fitted,
The steel sleeve is pressed and crimped from the outer circumference toward the center.
The tip of the blade-shaped convex portion covers the rust-proof coating.
Penetrates into contact with the steel single strand, and
The inner periphery of the sleeve is fitted into the recess between the steel wires.
The crimping is performed in the state of being inserted .

A rust-preventive coating made of a synthetic resin is formed on the surface or the entire surface of the blade-shaped protrusion of the steel sleeve, and the blade-shaped protrusion of the steel sleeve is formed of the steel sleeve and the steel tensile member. Preferably penetrates the rust-preventive coating on the surface.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the present invention will be described with reference to FIGS.
Referring to FIG. 1 to 7 show a first embodiment of the present invention. In FIG.
This is a fixing steel sleeve that is crimped to the outer periphery of the end of the strand 6. After the crimping to the PC strand 6, a screw portion 13 is formed on the outer periphery of the steel sleeve 10. The nut is screwed.

As shown in FIG. 2, the steel sleeve 10 before being crimped to the PC strand 6 has a straight cylindrical through hole formed in the center, and the entire inner periphery thereof has a sharp edge. The protruding portion 16 is a single strand of steel 7, 7 of the PC strand 6.
It is engraved in a screw shape (spiral shape) opposite to the twist direction. Then, the end of the PC strand 6 is inserted into the central through-hole of the steel sleeve 10, and the steel sleeve 10 is plastically deformed by pressing from the outer peripheral side by extrusion, drawing or the like using a die. The sleeve 10 is pressed against the outer periphery of the end of the PC strand 6.

Further, at the time of pressure bonding, as shown in FIG. 3, the blade-shaped convex portion 16 on the inner periphery of the steel sleeve 10 is pressed substantially perpendicularly to the outer surface of the PC strand 6 without slipping. The steel strands 7 penetrate the rust-preventive coating 9 on the surface of the PC strand 6 and come into contact with the surfaces of the steel strands 7, 7,. I am trying to. Therefore, the rust-preventive coating 9 on the surface of the PC strand 6 is not unnecessarily scraped off by the blade-shaped projections 16, so that corrosion of the PC strand 6 can be suitably prevented, and furthermore, the surface of the PC strand 6 can be prevented. Since the synthetic resin forming the rust-preventive coating 9 is pushed away into the space between the blade-shaped protrusions 16, sufficient pressure can be obtained.

Further, as shown in FIG. 4, the steel sleeve 10 is deformed from the outer peripheral side until the inner peripheral portion is plastically deformed and sunk into the concave portion between the single steel wires 7 of the PC strand 6. As a result, the convex portion (the portion formed by plastic deformation) on the inner periphery of the steel sleeve 10 and the PC
The concave portion on the outer periphery of the strand 6 (the portion between the single steel wires 7, 7) meshes with each other to increase the gripping force. Further, since the blade-shaped convex portion 16 is formed on the entire inner periphery of the steel sleeve 10, the inner peripheral portion of the steel sleeve 10 is sunk into the concave portion of the PC strand 6 so that the PC
The rust-proof coating 9 is formed not only on the convex portion of the strand 6 but also on the concave portion by the blade-shaped convex portion 16 of the steel sleeve 10.
Can be penetrated. Therefore, PC strand 6
And the steel sleeve 10 can be firmly integrated,
The present invention can also be applied to fixing a large-diameter PC strand having a large introduced stress.

[0014] The fixing device having the above-described configuration uses a PC.
In order to fix the strand 6, as shown in FIG. 5, the PC strand 6 is inserted through a screw pipe 17 having a through hole at the center and a threaded portion formed on the outer periphery, and a hydraulic jack is inserted into the steel sleeve 10. With the PC strand 6 tensioned by connecting the nuts, a fixing nut 18 is screwed into the threaded pipe 17 and fastened to the supporting plate 5 side to be fixed. The fixing nut 18 may be screwed into the steel sleeve 10 and fastened. Also,
A clog 19 having a U-shaped opening shown in FIG. 7 may be inserted between the steel sleeve 10 and the supporting plate 5 as shown in FIG.

FIG. 8 shows a second example of the embodiment of the present invention. In the figure, reference numeral 20 denotes a fixing steel sleeve crimped on the outer periphery of the end of the PC strand 6. No screw portion for screwing the fixing nut is formed on the outer periphery of the steel sleeve 20. To fix the PC strand 6, the end face of the steel sleeve 20 is brought into contact with the supporting plate 5, Alternatively, a clog 19 having a U-shaped opening is inserted between the steel sleeve 20 and the support plate 5.

The steel sleeve 20 before being press-bonded to the PC strand 6 has a straight cylindrical through hole formed in the center, and a sharp blade-like convex portion 26 is formed on the entire inner periphery thereof. 6 are engraved in a screw shape (spiral shape) opposite to the twisting direction of the single steel wires 7, 7,.... Then, the end of the PC strand 6 is inserted into the central through-hole of the steel sleeve 20, and the steel sleeve 20 is plastically deformed by pressing the steel sleeve 20 from the outer peripheral side by extrusion, drawing or the like using a die. The sleeve 20 is pressed against the outer periphery of the end of the PC strand 6.

It is to be noted that the blade-shaped convex portion 26 of the steel sleeve 20 penetrates the rust-proof coating 9 on the surface of the PC strand 6;
The inner peripheral portion of the steel sleeve 20 is plastically deformed and sunk into the concave portion between the single steel wires 7 of the PC strand 6, and the like, as in the case of the steel sleeve 10.

FIG. 9 shows a third example of the embodiment of the present invention. In the figure, reference numeral 30 denotes a fixing steel sleeve crimped around the outer periphery of the end of the PC strand 6. Before crimping to the steel sleeve 30, a threaded portion 33 is formed in advance on the outer periphery of one end side (the opposite side of the crimped portion 34) of the steel sleeve 30 to connect a hydraulic jack and screw a fixing nut. I have.

The steel sleeve 30 before being crimped to the PC strand 6 has a straight cylindrical non-through hole formed at the center on the crimping portion 34 side. The portion 36 is engraved in a screw shape (spiral shape) in the direction opposite to the twisting direction of the steel strands 7 of the PC strand 6. Then, PC is inserted into the central non-through hole of the steel sleeve 30.
Insert the end of the strand 6 and extrude using a die,
The crimping portion 34 of the steel sleeve 30 is pressurized from the outer peripheral side by drawing or the like and plastically deformed, so that the steel sleeve 30 is crimped on the outer periphery of the end of the PC strand 6.

It is to be noted that the blade-shaped convex portion 36 of the steel sleeve 30 penetrates the rust preventive coating 9 on the surface of the PC strand 6;
The inner peripheral portion of the steel sleeve 30 is plastically deformed and sunk into the concave portion between the single steel wires 7 of the PC strand 6, and the like, as in the case of the steel sleeve 10.

FIG. 10 shows a fourth embodiment of the present invention. In the figure, reference numeral 40 denotes a fixing steel sleeve which is crimped to the outer periphery of the end of the PC strand 6. A fixing portion 43 protruding outward is formed on the outer periphery of one end side (the opposite side of the crimping portion 44) of the steel sleeve 40. To fix the PC strand 6, the fixing portion 4 of the steel sleeve 40 is fixed.
3 is brought into contact with the support plate 5.

The steel sleeve 40 before crimping to the PC strand 6 has a straight cylindrical non-through hole formed in the center on the crimping portion 44 side, and a sharp blade-shaped convex portion is formed on the entire inner periphery. 46 are engraved in a screw shape (spiral shape) in the direction opposite to the twisting direction of the steel strands 7 of the PC strand 6.
Then, the end of the PC strand 6 is inserted into the non-through hole at the center of the steel sleeve 40, and the crimping portion 44 of the sleeve 40 is plastically deformed by pressing the crimping portion 44 of the sleeve 40 from the outer peripheral side by extrusion, drawing or the like using a die. The steel sleeve 40 is pressed against the outer periphery of the end of the PC strand 6.

The edge-shaped projection 46 of the steel sleeve 40 penetrates the rust-proof coating 9 on the surface of the PC strand 6;
The inner peripheral portion of the steel sleeve 40 is plastically deformed and sunk into the concave portion between the single steel wires 7 of the PC strand 6, and the like, as in the case of the steel sleeve 10.

It is to be noted that a rust-preventive coating made of a synthetic resin may be formed on the surface of the blade-shaped convex portion of the steel sleeve or on the entire surface of the steel sleeve, so that the corrosion of the PC strand is more suitably prevented. be able to. In this case, the blade-shaped convex portion of the steel sleeve penetrates the rust-preventive coating on the surface of the steel sleeve and the PC strand, and comes into contact with the steel strands 7, 7,... Of the PC strand.

In the above-described embodiment, the case where the single steel wire is a PC steel wire is shown.
In addition, for example, a steel wire having a lower strength than a PC steel wire used for a tensile material for retaining may be used. In the above-described embodiment, the case where the steel tensile material is a strand formed by twisting steel single strands is shown. However, the steel tensile material is a parallel bundle without twisting the single strands. It may be one that has been made. Further, the steel tensile member may be a multi-stranded steel tensile member in which side wires are wound around a core wire in multiple layers, or a stranded wire bundle in which strands in which steel wires are twisted are bundled. Further, the steel tensile material does not have to be made of only a single steel wire, and is, for example, a so-called wire rope in which the core wire is made of hemp rope other than steel wire and the side wire is made of steel wire. You may.

Further, in the above-described embodiment, the case where the steel sleeve is crimped to the end of the steel tensile member has been described. However, for example, when the steel tensile member is driven into the ground as an anchor, A steel sleeve may be crimped to an intermediate part other than the end of the tensile member, and a plurality of steel sleeves may be crimped to the end and the intermediate part of the tensile member.

[0027]

As described above, in the method of manufacturing a steel tensile member fixing device according to the present invention, a steel sleeve having an edge-shaped convex portion on the inner periphery is pressed against the outer periphery of the steel tensile member to form a steel member. Unnecessary removal of the rust-preventive coating on the surface of the steel tensile material by penetrating the blade-shaped convex part of the sleeve through the synthetic resin rust-preventive coating on the surface of the steel tensile material and contacting the steel single strand Without being, it is possible to suitably prevent corrosion of the steel tensile member, and sufficiently press-bond the steel tensile member and the steel sleeve,
The steel tensile member can be suitably fixed.

Then, the inner peripheral portion of the steel sleeve is recessed into the concave portion between the single steel wires constituting the steel tensile member, so that the inner peripheral portion of the steel sleeve and the steel peripheral portion are indented. The concave portion of the tension member can be engaged with the steel tension member. In particular, in the case of a steel tension member in which a plurality of steel single strands are twisted, the steel tension member and the steel sleeve can be firmly integrated. .

Further, by forming a rust-preventive coating made of a synthetic resin on the surface or the entire surface of the blade-shaped convex portion of the steel sleeve, corrosion of the steel tensile member can be more suitably prevented.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a first example of an embodiment of a method for manufacturing a steel tensile material fixing device according to the present invention.

FIG. 2 is an enlarged longitudinal sectional view showing a state before crimping of a steel sleeve in FIG. 1;

FIG. 3 is an enlarged vertical sectional view showing a state after crimping of the steel sleeve in FIG. 1;

FIG. 4 is an enlarged cross-sectional view showing a state after crimping of the steel sleeve in FIG. 1;

FIG. 5 is a cross-sectional view illustrating an example of fixing by the fixing device of FIG.

FIG. 6 is a cross-sectional view illustrating another example of fixing by the fixing device of FIG. 1;

FIG. 7 is a front view of the clog in FIG. 5;

FIG. 8 is a longitudinal sectional view showing a second example of the embodiment of the method for manufacturing a steel tensile material fixing device according to the present invention.

FIG. 9 is a longitudinal sectional view showing a third example of the embodiment of the method for manufacturing a steel tensile material fixing device according to the present invention.

FIG. 10 is a longitudinal sectional view showing a fourth example of the embodiment of the method for manufacturing a steel tensile material fixing device according to the present invention.

FIG. 11 is a cross-sectional view showing a PC strand (steel tensile material) having a rust-proof coating.

FIG. 12 shows an example of a conventional tension fixing device made of steel (wedge fixing).
FIG.

FIG. 13 is a longitudinal sectional view showing another example (pressure bonding block) of a conventional steel tensile material fixing device.

[Explanation of symbols]

 5 Support plate 6 PC strand (steel tensile material) 7 Single strand of steel 9 Rust prevention coating 10 Steel sleeve 13 Screw part 16 Blade-shaped convex part 17 Screw tube 18 Nut 19 Clog 20 Steel sleeve 26 Blade-shaped convex part Reference Signs List 30 steel sleeve 33 screw part 34 crimping part 36 blade-shaped convex part 40 steel sleeve 43 fixing part 44 crimping part 46 blade-shaped convex part

Claims (2)

(57) [Claims] 1. A plurality of steel single strands are twisted , and a steel tensile member having a rustproof coating made of synthetic resin on the surface is fixed.
In the method for manufacturing a steel tensile member fixing device,
On the outer periphery of the upholstery, a steel sleeve with a blade-shaped convex on the inner surface
Fit the steel sleeve from the outer circumference toward the center.
By pressing and caulking, the tip of the blade-shaped convex portion
When it comes into contact with the steel single strand through the rust prevention coating,
In addition, the inner peripheral portion of the steel sleeve is formed between the steel single wires.
It is characterized in that it is crimped while it is embedded in the concave part
A method for manufacturing a tensile material fixing device made of steel. 2. A rust preventive coating according to the surface or synthetic resin on the entire surface of the blade-shaped protrusions of the steel sleeve is formed by a crimping
The method for manufacturing a steel tensile member fixing device according to claim 1, wherein the blade-shaped convex portion of the steel sleeve is penetrated by a rust preventive coating on the surface of the steel sleeve and the steel tensile member.