JP2838507B2 - 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 a cable for suspending a prestressed concrete structure, a cable for suspending a bridge or the like, and a steel tension fixing device used for a steel tension for tensioning a retaining plate.

[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. 10 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. 11, an end of the PC tosland 6 is inserted into a tapered cylindrical through hole of the fixing member 3 which comes into contact with the support plate 5, and a blade-shaped ridge is fixed between the two. The fixing wedges 4 and 4 are pulled 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. 12, a ridge is formed on the outer periphery of an end portion of a PC strand 1 by rolling or the like, and a steel sleeve 2 is covered thereon, 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. 11, the fixing wedges 4 and 4 are drawn into the through holes of the fixing body 3 so that the inner edge of the fixing wedges 4 and 4 has 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. 12 is applied to a PC strand 6 having a rust-proof coating, slippage occurs when 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,
It is an object of the present invention to provide a steel tensile member fixing device that firmly integrates a steel tensile member and a steel sleeve and that does not unnecessarily scrape off a rust-proof coating on the surface of the steel tensile member. .

[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.
A steel sleeve comprising a relatively soft outer cylinder member and an inner cylinder member which is relatively hard and has a cut portion in the axial direction and can be radially reduced in diameter, and a blade is provided on an inner periphery of the inner cylinder member. shaped protrusion is fixed, the steel sleeve, is pressed against the outer periphery of the steel tension members, the blade-like protrusions is dig into the steel tension member
In the steel tensile member fixing device, the surface of the steel tensile member
A rust-proof coating made of synthetic resin is formed, and the steel
Anticorrosion of synthetic resin on the surface or all surface of the blade-shaped protrusion
A coating is formed, and the blade-shaped protrusion of the steel sleeve is
The rust-proof coating on the surface of the steel sleeve and the steel tensile material
It penetrates into the steel tensile material .
In addition, it is preferable that the outer periphery of the inner cylinder member is tapered.

[0009]

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 6 show a first example of an embodiment of the present invention.
Is a fixing steel sleeve that is crimped to the outer periphery of the end of the PC strand 6. After crimping to the PC strand 6, a screw portion 13 is formed on the outer periphery of the steel sleeve 10, and a hydraulic jack is connected. The fixing nut is screwed.

[0010] The steel sleeve 10 before crimping to the PC strand 6 is relatively soft (softer than the inner cylinder member 15) and relatively hard (harder than the outer cylinder member 11). ), And a tapered cylindrical through hole 12 is formed in the center of the outer cylinder member 11. Each of the inner cylindrical members 15 has a tapered cylindrical outer peripheral shape corresponding to the through hole 12, a straight cylindrical through hole is formed at the center, and a sharp blade-like convex portion 16 is formed on the entire inner periphery. Made a cylindrical member engraved in a screw shape (spiral shape) in the opposite direction to the twisting direction of the steel strands 7, 7,... Of the PC strand 6, and halved vertically (divided into two in the circumferential direction). It has a wedge shape, and the diameter can be reduced in the radial direction by a gap between two cut portions formed in the axial direction.

The inner cylindrical member 1 of the steel sleeve 10
The end of the PC strand 6 is inserted into the through hole between 5, 5 and 15, and the steel sleeve 1 is extruded and drawn using a die.
The steel sleeve 10 is pressed against the end of the PC strand 6 by pressurizing the outer cylinder member 11 by applying pressure to the outer cylindrical member 11.

Accordingly, 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. Penetrates through the rust-preventive coating 9, and pushes the synthetic resin constituting the rust-preventive coating 9 deep into the gaps between the blade-shaped protrusions 16, 16 so as to bite into the single steel wires 7, 7,. become. The inner circumference of the outer cylinder member 11 and the inner cylinder member 1
Since the outer circumferences of 5 and 15 are formed in corresponding tapered cylindrical shapes, they can be pressure-bonded without shifting. Therefore, the rust-preventive coating 9 on the surface of the PC strand 6 is not unnecessarily scraped off by the bite of the blade-shaped convex portion 16, so that the corrosion of the PC strand 6 can be suitably prevented. Further, the PC strand 6 and the steel sleeve 10 can be firmly integrated, and the present invention can be applied to fixing of a large-diameter PC strand having a large introduction stress.

[0013] The fixing device having the above-described configuration uses a PC.
In order to fix the strand 6, as shown in FIG. 4, the PC strand 6 is inserted through a threaded pipe 17 having a through hole in 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. 6 may be inserted between the steel sleeve 10 and the supporting plate 5 as shown in FIG.

FIG. 7 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 comprises a relatively soft outer cylinder member 21 and relatively hard inner cylinder members 25, 25. A straight cylindrical through hole 22 is formed. The inner cylindrical members 25, 25 have a cylindrical outer peripheral shape corresponding to the through holes 22, a straight cylindrical through hole is formed at the center, and a sharp blade-like convex portion 26 is formed on the entire inner periphery. A plate in which a cylindrical member engraved in a screw shape (spiral shape) opposite to the twisting direction of the steel strands 7, 7,... Of the PC strand 6 is vertically divided in half (divided into two in the circumferential direction). The diameter can be reduced in the radial direction by a gap between two cut portions formed in the axial direction. Further, the inner cylinder members 25, 25 are formed thinner than the inner cylinder members 15, 15 of the steel sleeve 10 described above.

The inner cylindrical member 2 of the steel sleeve 20
The end of the PC strand 6 is inserted into the through hole between 5, 5 and 25, and the steel sleeve 2 is extruded and drawn using a die.
The steel sleeve 20 is pressed against the end of the PC strand 6 by applying a pressure from the outer peripheral side to cause plastic deformation. Therefore, as in the case of the steel sleeve 10, the steel sleeve 2
The 0 blade-like projections 26 penetrate the PC strand 6 through the rust-preventive coating 9 on the surface.

Further, the steel sleeve 20 is provided on the inner cylindrical member 2.
5 and 25 are pressed from the outer peripheral side to the extent that they are plastically deformed and sink into the concave portions between the steel strands 7 of the PC strand 6. The gripping force is increased by the meshing of the cylindrical portion (the portion formed by plastic deformation) and the concave portion on the outer periphery of the PC strand 6 (the portion between the single steel wires 7, 7). Further, since the blade-like convex portions 26 are formed on the entire inner periphery of the steel sleeve 20, the blade-like convex portions 26 of the steel sleeve 20 bite into the concave portions as well as the convex portions of the PC strand 6. I can do it.

FIG. 8 shows a third embodiment of the present invention. In the figure, reference numeral 30 denotes a fixing steel sleeve pressed 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 comprises a relatively soft outer cylinder member 31 and relatively hard inner cylinder members 35, 35. A straight cylindrical non-through hole is formed in the center of the side. The inner cylindrical members 35, 35 have a cylindrical outer peripheral shape corresponding to the non-through holes. The cylindrical member 3
5, 35 are the inner cylindrical members 25,
As in the case of 25, blade-shaped protrusions 36, 36 are engraved on the inner periphery, and the blade-shaped protrusions 36, 36 bite into the PC strand 6.

FIG. 9 shows a fourth example of the embodiment of the present invention. In the figure, reference numeral 40 denotes a fixing steel sleeve crimped on 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 43 of the steel sleeve 40 is used.
Are brought into contact with the support plate 5.

The steel sleeve 40 before being crimped to the PC strand 6 comprises a relatively soft outer cylinder member 41 and relatively hard inner cylinder members 45, 45. A straight cylindrical non-through hole is formed in the center of the side. The inner cylinder members 45, 45 have a cylindrical outer peripheral shape corresponding to the non-through holes. In addition, the inner cylinder member 4
5, 45 are the inner cylindrical members 25,
In the same manner as 25, blade-shaped protrusions 46, 46 are engraved on the inner periphery, and the blade-shaped protrusions 46, 46 bite into the PC strand 6.

In the above-described embodiment, the case where the inner cylindrical member is divided into two in the circumferential direction having two cut portions in the axial direction is shown. It is only necessary that a gap is formed in the direction and the diameter can be reduced in the radial direction. Therefore, a C-shaped cross section having one cut portion may be used. It may be divided into three, four,... In the circumferential direction having a cut portion.

Incidentally, a rust-preventive coating made of a synthetic resin is formed on the entire surface of the steel sleeve, so that corrosion of the steel tensile member can be more suitably prevented. 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 steel tensile member, and bites into the steel tensile member.

Further, 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.

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.

[0026]

As described above, the steel tensile material fixing device according to the present invention has a relatively soft outer cylindrical member and a relatively hard inner cylindrical member having a cut portion in the axial direction and capable of reducing the diameter in the radial direction. Using a steel sleeve made of a cylindrical member, a blade-shaped convex portion is fixedly provided on the inner periphery of the inner cylindrical member, and the steel sleeve is pressed against the outer periphery of the steel tensile member to form an inner periphery of the steel sleeve. By making the edge-shaped convex portion of the steel bite bite into the steel tensile member, the steel tensile member and the steel sleeve can be firmly integrated. And, by making the outer periphery of the inner cylinder member tapered, the outer cylinder member and the inner cylinder member can be suitably press-bonded without shifting.

Further, since the rust preventive coating is formed on the surface of the steel tension member according to the synthetic resin, the blade-like protrusions of the steel sleeve antirust coating to penetration by synthetic resin surface to a steel tension member In this way, the anticorrosion coating on the surface of the steel tensile member is not unnecessarily scraped off, and the corrosion of the steel tensile member can be suitably prevented. The sleeve and the sleeve can be firmly integrated.
Furthermore, since the rust-preventive coating made of a synthetic resin is formed 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 steel tensile material fixing device according to the present invention.

FIG. 2 is a cross-sectional view taken along line AA in FIG.

FIG. 3 is an enlarged longitudinal sectional view showing a state in which the blade-shaped convex portion of the steel sleeve in FIG. 1 has bitten into a PC strand (steel tensile material).

FIG. 4 is a sectional view showing an example of fixing by the fixing device of FIG.

FIG. 5 is a cross-sectional view illustrating another example of fixing by the fixing device of FIG. 1;

FIG. 6 is a front view of the clog in FIG. 5;

FIG. 7 is a longitudinal sectional view showing a second example of the embodiment of the steel tensile material fixing device according to the present invention.

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

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

FIG. 10 is a cross-sectional view showing a PC strand (steel tensile material) having a rust-proof coating.

FIG. 11 shows an example of a conventional tension fixing device made of steel (wedge fixing).
FIG.

FIG. 12 is a longitudinal sectional view showing another example (pressure bonding block) of a conventional steel tensile material fixing device.

[Explanation of symbols]

 Reference Signs List 5 Support plate 6 PC strand (steel tensile material) 7 Single strand of steel 9 Rust prevention coating 10 Steel sleeve 11 Outer cylinder member 12 Through hole 13 Screw part 15 Inner cylinder member 16 Blade-shaped protrusion 17 Screw pipe 18 Nut DESCRIPTION OF SYMBOLS 19 Geta 20 Steel sleeve 21 Outer cylinder member 22 Through-hole 25 Inner cylinder member 26 Blade-like convex part 30 Steel sleeve 31 Outer cylinder member 32 Non-through-hole 33 Screw part 34 Crimping part 35 Inner cylinder member 36 Blade-like convex part 40 Steel sleeve 41 Outer cylinder member 42 Non-through hole 43 Fixing part 44 Crimping part 45 Inner cylinder member 46 Blade-shaped convex part

Claims (2)

(57) [Claims] 1. A steel sleeve comprising a relatively soft outer cylinder member and an inner cylinder member which is relatively hard and has a cut portion in an axial direction and can be radially reduced in diameter. A steel-shaped tension member is fixed on the inner periphery, and the steel sleeve is pressed against the outer periphery of the steel-made tensile material, and the blade-shaped convex portion bites into the steel-made tensile material. In the fixing device , the steel
A rust-proof coating made of synthetic resin is formed on the surface of the tensile material,
Synthesized on the surface or the entire surface of the blade-shaped protrusion of the steel sleeve
A rust-preventive coating made of resin is formed in front of the steel sleeve.
The notched convex portion is a table of the steel sleeve and the steel tensile member.
Penetrated the steel tensile material by penetrating the anti-rust coating on the surface
And a steel tensile material fixing device. 2. The steel tensile member fixing device according to claim 1, wherein an outer periphery of the inner cylindrical member is tapered.