JPH0331832B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for fixing the ends of a composite twisted body using high-strength, low-elongation fibers.

[Conventional technology and its technical issues]

Wire rods based on high-strength, low-elongation fibers such as carbon fibers and polyaramid fibers, and twisted composites (strands and ropes) made by twisting multiple wires, have a low specific gravity.
It is non-corrosive, non-magnetic, and has high strength.
It has the characteristic of extremely low elongation deformation. For this reason, its use as a material to replace conventional steel wires, wire ropes, etc., such as reinforcing materials for prestressed concrete, is being considered.
However, in both applications, terminal processing is a problem. This is because unless a reliable fixing force can be easily obtained, the above characteristics cannot be exhibited and it cannot be used in practice.

Conventionally, the end treatment method for fiber ropes is as follows:
Methods of making eye splices on the ropes or splicing the ropes together have been used. These methods can be applied to conventional rope structures that are flexible and easy to untwist; It is difficult to apply thermosetting resins to the
It is also unsuitable in terms of work efficiency.

On the other hand, for steel wires and wire ropes, wedge socket types and metal sleeve crimping types are commonly used. In particular, the former wedge-type socket type is superior in terms of workability. However, when this method is simply applied to the terminal treatment of composite filaments or twisted bodies of high-strength, low-elongation fibers, the compressive action applied from the cone or sleeve causes shear breakage of the high-strength, low-elongation fibers. There was a problem in that a predetermined fixing force could not be obtained. Furthermore, due to the difference in physical properties between the fixing device and the filamentary body or twisted body, there was a problem in that when a tensile load is applied, the filamentous body or twisted body shrinks in diameter and easily comes off from the fixing device.

The present invention was devised to solve the above-mentioned problems, and its purpose is to manufacture the ends of a twisted body made of composite filaments using high-strength, low-elongation fibers on-site. It is an object of the present invention to provide a method that can be easily and reliably established.

[Means to solve the problem]

In order to achieve the above-mentioned object, the present invention provides a structure in which a fiber having a diameter approximately 10 times or more larger than the A buffer layer made of thermosetting resin is formed over the range of 200 mm and fills the valleys between adjacent composite filament bodies to form a cylindrical shape as a whole, and the socket is inserted with this buffer layer sandwiched between multiple cones. The method is to fit it in and secure it with a wedge.

As the buffer layer, it is preferable to use a thermosetting resin to integrally fill the gaps between adjacent wires or strands so that the end section has a substantially cylindrical shape.

The present invention is suitable for use when a composite filament made of high-strength, low-elongation fiber and thermosetting resin or a twisted body made of the composite filament as a wire is used as a reinforcing material for prestressed concrete. It also applies when used as a rope for securing or operating equipment.

〔Example〕

Embodiments of the present invention will be described below with reference to the accompanying drawings.

1 to 6 show an embodiment of the terminal fixing method according to the present invention. In the drawing, 1 is a composite filament, 2 is a twisted body having the composite filament 1 as a wire, 6 is a socket, and 7 is a split cone. The cones 7, 7 of which the socket 6 is split are generally made of metal, but may also be made of engineering plastic or a composite material of metal and plastic.

As shown in FIG. 2a, the composite filament 1 consists of a core body 1a in which a large number of ultra-thin long fibers 10 having high strength and low elongation properties such as carbon fibers, polyaramid fibers, and silicon carbide fibers are bundled, and an epoxy resin is applied to the core body 1a. , impregnated with thermosetting resin 3 such as unsaturated polyester resin or polyurethane resin, molded with a shaping die and removed excess resin, and then coated with a powder desiccant such as talc on the surface of core 1a to smooth the surface. After drying, a fiber coating 4 made of synthetic fibers such as polyester or nylon or high-strength, low-elongation fibers is applied around the outer periphery.

In this embodiment, the twisted body 2 is composed of seven composite filament bodies 1, and the seven composite filament bodies 1 coated with a powder desiccant and coated with fiber coating 4 as described above are twisted. The impregnated thermosetting resin 3 is cured by passing through a combing machine and twisting in a required pitch and twisting direction, and then heating.

When performing terminal treatment on such a twisted body 2, first, a buffer layer 5 is formed at the end portion of the twisted body 2. The buffer layer 5 should be formed over a range at least 10 times the diameter of the twisted body 2 in order to make it difficult to apply shearing force to the core body 1a even when compressive force is applied and to increase the contact area with the cone described later. is necessary.

In this embodiment, the buffer layer 5 is made of thermosetting resin. The thermosetting resin may be either a heat-setting type or a room-temperature setting type, and is applied to the surface of the twisted body 2 by any method such as brushing, spraying, dipping, etc., and then hardened. In the case of a heat curing type, after applying the resin, the part may be heated with a heater or dryer. In this case, the buffer layer 5 should fill the valleys 11 between the adjacent strands 1, 1 and have a solid cylindrical cross section as a whole, as shown in FIG. It is preferable that the diameter R of the stranded body at least equal to or slightly larger than the diameter R of the stranded body imaginably formed by each of the strands 1, 1, and to cover the surface of the strands 1 to an appropriate extent.

After the above operations, the buffer layer 5 is sandwiched between the split cones 7, 7, inserted into the socket 6, and compared by a wedge action.

More specifically, as shown in FIG. 4, the socket 6 has a tapered hole 60 with a radius r ₁ extending in the axial direction, and a split cone (divided into two in the embodiment) 7, 7.
has a common center with a tapered outer surface 70 having a radius r ₂ centered at positions _{P 2 and} P ₂ ′ that are eccentric from the center P 1 of the tapered hole 60 by a predetermined distance, and the center P ₁ of the tapered hole 60. A gap t corresponding to the total distance between _{the eccentric points P 2 and} P ₂ ' is formed between the end surfaces 7a, 7a of each split type cone 7, 7.

For comparison, the split cones 7, 7 are pulled out from the tapered hole 60 as shown in FIG.
Pull it out from the large diameter side of 0. And Figure 1b
The arcuate inner surfaces 71, 71 of the split cones 7, 7 are brought into contact with the buffer layer 5 formed at the ends, as shown in FIG. In this state, as shown in FIG.
Push it to 0. Then, the twisted body 2 is pulled from the other end side.

As a result, the split cones 7, 7 have tapered holes 60
The end portion of the twisted body is drawn into the arcuate inner surface 71, and the gap t decreases due to its axial movement.
71, it is strongly tightened in the radial direction. At this time, a buffer layer 5 having a length of at least 10 times the diameter of the twisted body is placed on the part that is pressed between the split cones 7, 7.
The buffer layer 5 fills the valleys 11, 11 of the wires 1, 1 constituting the twisted body 2, and the cross section of this portion has a substantially solid cylindrical shape. Therefore, the clamping force by the split cones 7, 7 does not directly act on the core 1a or the strands 1, 1 formed therefrom. Therefore, shear breakage of high strength, low elongation fibers does not occur. Moreover, since the buffer layer 5 fills the valley between the wires 1, 1, pressure deviation of the wires 1, 1 does not occur, and the contact area with the arcuate inner surfaces 71, 71 increases substantially. The required fixing force can be obtained efficiently and reliably.

Specific examples of the present invention are as follows.

Long carbon fibers are bundled, impregnated with epoxy resin, molded with a shaping die, coated with talc, and 7 4.2mmφ composite filaments braided with polyester fibers are twisted together as strands. Then, the epoxy fibers were heated and cured to obtain a twisted body with a diameter of 12.5 mmφ.

The terminal part of this twisted body has a length of about 160 mm,
An epoxy fibrous buffer layer was formed. That is,
Mix equal amounts of the main agent and curing agent, stir at a temperature of 25°C, apply the mixture to the end part, and then use a dryer to
It was dried at ℃ for 1 hour. The buffer layer is integrated with the twisted body, filling the gaps between adjacent strands,
The part had a cylindrical shape with a diameter of approximately 12.6 mm.

The terminal part was formed using a steel socket with a length of 150 mm having a tapered hole with a large diameter part of 40 mm and a small diameter part of 13 mm, and a two-split cone with an eccentric distance of 2 mm, a radius r ₂ 18 mm, a virtual radius r ₃ 6 mm, and a length 150. It has become established.

The efficiency of the obtained end-treated portion was measured using a tensile tester. As a result, the design cutting load of the twisted combination is 15960
The twisted body was cut at the mouth of the socket at 16,047 Kgf. On the other hand, when it was fixed under the same conditions except that no buffer layer was provided (comparative example),
It was cut at 10400Kgf (65.2% of the cutting load).

Note that the composite filament body 1 and twisted body 2 of the present invention are not limited to those shown in the drawings. For example, a surface area increasing material made of a fibrous tape or string may be fixed to the outer periphery of the composite filament 1 or the stranded body 2 while the thermosetting resin is not yet cured.

When using the twisted body 2 as a reinforcing material for prestressed concrete, a buffer layer is formed at both ends. For example, in the case of a post-tension method,
A reinforcing material is made in advance and inserted into a hole in the concrete material (for example, a girder), and a socket is placed behind the bearing plate that is in contact with the concrete material, and one end is fixed. Then, place a socket on the other end, and use the fixing jack to press the split cone in with tension. The split cone and buffer layer are secured by the technique of FIG.

〔Effect of the invention〕

According to the present invention as described above, when fixing the end of a fiber rope, particularly a strand or rope using high-strength, low-elongation fibers, a composite filament in which high-strength, low-elongation fibers are impregnated with a thermosetting resin and cured is used. A thermosetting resin is applied to the end portion of the twisted composite body 2 in which 1 is a bare wire in advance, over a range of about 10 times or more of the diameter, and to fill in the valleys between adjacent composite filament bodies 1 so as to form a cylindrical shape as a whole. forming a buffer layer 5 consisting of
Since this buffer layer 5 is sandwiched between the plurality of cones 7, 7 and is fitted into the socket 6 and secured with a wedge, when the cones 7, 7 are tightened in the radial direction by the taper of the socket 6, this cone 7, 7 tighten the buffer layer 5 which is made of the same material and integrated with the matrix of the composite filament body 1, and the buffer layer 5 fills the gap between adjacent composite filament bodies 1, so that the cross section of the part is Since it has a solid rod-shaped cross section, the strong pressing force of the cones 7, 7 does not act on the high strength, low elongation fibers that constitute the composite filament 1. Therefore, shear breakage of the high-strength, low-elongation fibers does not occur, and pressure deviation of the composite filament 1 also does not occur. Therefore, it can be easily and reliably fixed on site, and the properties of strands and ropes made of high-strength, low-elongation fibers (high strength, light weight, low elongation, corrosion resistance) can be fully demonstrated. You can get excellent results by being able to do this.

[Brief explanation of the drawing]

Figures 1a, b, c, and d are sectional views showing the fixing method of the present invention step by step, Figure 2 is a sectional view taken along the - line of Figure 1a, and Figure 2a is a partially enlarged view of Figure 2. Figure 3 is a sectional view taken along the - line in Figure 1 a, Figure 4 is an enlarged sectional view taken along the - line in Figure 1 c, and Figure 5 is an enlarged sectional view taken along the V-V line in Figure 1 d. It is an enlarged sectional view. DESCRIPTION OF SYMBOLS 1... Composite filament, 1a... Core, 2... Twisted body, 3... Thermosetting resin, 5... Buffer layer, 6...
Socket, 7, 7... Split cone, 10... High strength, low elongation fiber.

Claims (1)

[Claims] 1. When fixing the ends of strands or ropes using high-strength, low-elongation fibers, a twisted body 2 whose strands are composite filaments 1 made by impregnating and curing high-strength, low-elongation fibers with a thermosetting resin. At the end, pre-approximately 10 mm in diameter.
A buffer layer 5 made of a thermosetting resin is formed so as to cover an area more than twice as large and fill the valleys between adjacent composite filament bodies 1 so as to form a cylindrical shape as a whole. , 7 is inserted into a socket 6 and fixed with a wedge. A method for fixing a terminal of a composite twisted composite using high-strength, low-elongation fibers.