JP2772358B2 - Terminal fixing method and terminal fixing device for fiber composite material - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a terminal fixing method and a terminal fixing device for a fiber composite material formed using high-strength, low-elongation fibers.

(Conventional technology) A fiber composite comprising a high-strength, low-elongation fiber impregnated with a thermosetting resin and cured to form a rod-like body, a twisted body, and the like has been developed (Japanese Patent Publication No. 57-25679 No. 62-18679, etc.), the high-strength low-elongation fiber has excellent physical and chemical properties such as light weight, corrosion resistance, high strength, low elongation, and low relaxation. As materials that can replace conventional steel wires and wire ropes, for example, use as pre-stressed concrete, tension materials for pre-tensioned and post-tensioned concrete, out-cables, etc., is considered. It is important to easily and reliably fix the terminal portion of the material.

Further, conventionally, the end portion of the fiber ropes, ice-splicing, or the fixing method of splicing the rope is adopted, but in the case of a flexible and easy to untwist rope or similar fiber composite material. It is difficult to apply the fixing method, and wedge socket type or metal sleeve type terminal fixing means applied to steel wire or wire rope has excellent workability. When applied to fixing,
Due to the local compressive action applied from the cone, the fiber composite material is sheared off, and a predetermined fixing force is not secured. When a tensile load is applied, the fiber composite material tends to come off from the cone due to a difference in physical properties between the fiber and the cone.

In view of the above situation, the present applicant has developed and proposed the following method for fixing a fiber composite terminal. That is, the high-strength low-extension fiber is impregnated with the thermosetting resin, and the end of the cured fiber composite is inserted into a die-casting mold, and a low-melting-point metal is injected into the die-casting mold to form an outer periphery of the end. A cylindrical fixing part is formed on the fiber, and a compressive force is applied to the identification attachment part from the outer periphery by a press machine, the identification attachment part is pinched by a plurality of cones, and both are inserted into the socket, and the fiber composite material has a wedge action. (Japanese Patent Application No. 1-87341)
No.), the formation of the fixing portion is easy and reliable, and the fixing power is enhanced.

(Problems to be Solved by the Invention) The terminal fixing method of the fiber composite material proposed earlier has features in formation of a fixing portion, workability, fixing power to fibers, and the like. The low-melting metal formed has relatively poor creep properties and is durable for short-time tension, but not for long-time. (The above-mentioned end processing is applied to a fiber composite material with a cutting load of 16tf.) Tensioned by pinching wedges
If 8.7tf is applied, the terminal part will be destroyed within about one hour), and the local compressive action that recurs from the wedge will cause shear fracture in the low melting point metal. Are easily entrained, and the strength of the fixing portion becomes non-uniform, which causes a problem of quality deterioration.

(Means for Solving the Problems) The present invention has been developed to address the above-mentioned problems, and has a low melting point inside a die-casting die by inserting a terminal portion of the fiber composite material into the die-casting die. A metal is injected, a cylindrical fixing portion is formed on the outer periphery of the terminal portion with the same low melting point metal, and the identification attachment portion is inserted into the metal pipe, and a compressive force is applied from the outer peripheral surface of the metal pipe by a press. By crimping the fixing portion to the fixing portion with a metal pipe, creep, shear breakage, and the like of the identification attaching portion are prevented.

Further, by fixing the fixing portion with the metal pipe with a plurality of wedges, inserting the fixing portion with the metal pipe into the socket together with the wedge, and fixing the terminal portion of the fiber composite material to the fixed portion by wedge action. , Enables high wedge fixing and high fixing power.

(Operation) By inserting the end portion of the fiber composite material into the die casting mold and injecting the low melting point metal into the die, the outer periphery of the end portion of the fiber composite material is formed in the same mold by the low melting point metal. A cylindrical fixing portion having a desired shape is formed on the metal pipe. Further, the identification attachment portion is inserted into the metal pipe, and a compressive force is applied from the outer peripheral surface of the metal pipe by a press machine to press the metal pipe against the fixing portion. By providing a fixing section, the low melting point metal forming the fixing section is well impregnated in the fiber strand to obtain a high fixing force, and is formed to be thin, and is covered with a metal pipe having a good creep property and pressure bonding. In combination, creep, shear fracture and the like are effectively prevented.

The metal pipe non-fixed part is sandwiched by multiple split wedges,
Even if the end of the fiber composite material is fixed to the part to be fixed by wedge action by inserting it into the socket together with the fixing part wedge, the metal pipe has better creep property than low melting point metal and is stronger against shearing, and it is added from wedge chuck The local compressive force does not act on the low melting point metal, and has excellent fixing performance, and the end portion of the fiber composite material is easily, reliably and strongly fixed.

(Embodiment) FIGS. 1 to 3 show one embodiment of the present invention, in which 1 is a fiber composite material, 2 is a die casting mold, 3 is a fixing portion formed of a low melting point metal, and 4 is a metal. The pipe 5 is a press machine (cold press machine), and the process of fixing and processing the end portion of the fiber composite material 1 will be described with reference to the drawing. First, as shown in FIG. The end portion (fixed section) of the fiber composite material 1 is inserted into the center shaft portion in the inside 2, and in this state, the inside of the low melting point metal die casting mold 2 (injection port)
2a) is filled, filled and solidified to form a cylindrical fixing portion 3.

The fiber composite 1 bundles a large number of high-strength low-elongation fibers such as carbon fibers, polyaramid fibers, and silicon carbide fibers and impregnates them with a thermosetting resin (epoxy resin, unsaturated polyester resin, polyurethane resin, etc.). The fixing portion 3 is formed of a low melting point metal having a melting point of 600 ° C. or less, for example, a low melting point metal such as an aluminum alloy, a zinc alloy, and a lead alloy. Metal is applied,
The inner diameter of the die casting mold 2 is 1.4 times or less the outer diameter of the end of the fiber composite 1. Fiber composite 1 is die-casting mold 2
The low-melting-point metal is press-fitted and filled into the die-casting hole, impregnated into the fiber strand, and has a relatively small thickness around the outer periphery of the fiber composite (1/3 of the outer diameter of the fiber composite 1).
5 or less).

Next, the fixing unit 3 is taken out of the die casting mold 2 (see FIG. 1C), and the fixing unit 3 is removed as shown in FIGS.
As shown in FIG. 1, the metal pipe 4 is inserted into the metal pipe 4 and further, as shown in FIG. The metal pipe 4 is pressed against the fixing unit 3 by applying a uniform compressive force toward the fixing unit 3 to form the fixing units 3 and 4 with the metal pipe. The metal pipe 4
The length of the fixing portion 3 is substantially the same as that of the fiber composite 1, and is about 1.5 times the outer diameter of the fiber composite 1. A steel tube or a stainless steel pipe which is resistant to shearing and has a good creep property is applied. And compressing it to greatly reduce the thickness of the fixing section 3 to reduce the entrapment of air bubbles, and the creep property and shear strength of the fixing section 3 are effected by the tight and strong connection of the metal pipe 4 by pressure bonding. Has been improved.

As shown in FIGS. 2 and 3, the fixing portions 3 and 4 with metal pipes are sandwiched by a plurality of split wedges 7, and further inserted into sockets 8 together with the wedges 7 and combined to form fixing portions 3 with metal pipes. The end portion of the fiber composite material 1 is fixed to the portion to be fixed by the wedge action via the and 4. The metal pipe 4 is resistant to shearing and is applied from wedges, so that the local compressive action is not transmitted to the low-melting-point metal, so that shear fracture is prevented and the fixing function is markedly enhanced.

To explain a specific example, a 12.5 mmφ fiber composite material end was inserted into a die casting mold over a length of 250 mm. The diameter of the casting part in the die casting mold is 15 mmφ, the length is 250 mm, and a zinc alloy having a melting point of 390 ° C is heated to 420 ° C in this die casting mold and 150 kgf / c
The mixture was injected at a pressure of m ² and solidified by cooling to obtain a fixing portion.

After that, the fixing part is removed with an outer diameter of 22 mm, an inner diameter of 16 mm, and a length of
It was inserted into a 0 mm steel pipe and pressed from two directions with a compression force of 1.9 tf / cm ² using a cold press. And this fixing part 2
It was pinched by a 1.8 mm PC wedge, inserted into a socket, and the fixing efficiency was measured.

The results of the measurements are shown in Table 1, As is evident from Table 1, no matter where the fixing position was, the standard cutting load was exceeded at all, and no abnormalities were observed even if the strain was applied for 24 hours at 8.7 tf, and the residual strength was 100% or more. was gotten.

(Effects of the Invention) The present invention has the above-described configuration, and forms a fixing portion by inserting a terminal portion of a fiber composite material into a die casting mold and injecting a low melting point metal, and forms the fixing portion on a metal pipe. The fixing part with the metal pipe is easily and reliably formed by inserting the part, compressing and pressing the metal pipe by the press machine, and the low melting point metal is impregnated into the fiber strand, compacted and formed into a thin wall. After being covered and crimped with a pipe, the fixing section with the metal pipe has a strong fixing force, and the fixing performance of the end portion of the fiber composite material is greatly improved.

Also, even if a wedge chuck (wedge, socket) is applied to the fixing part with a metal pipe, the local shearing action added from the wedge is not transmitted to the low melting point metal, and the function of the wedge is effectively exhibited, thereby obtaining excellent fixability. Can be

[Brief description of the drawings]

1 (A) to 1 (G) are each a process diagram of a fixing method according to an embodiment of the present invention, FIG. 2 is a longitudinal sectional view showing a mounting state of a socket chuck, and FIG. 3 is a diagram of FIG. It is a longitudinal cross-sectional view which shows a disassembled state. 1: Fiber composite material, 2: Die casting mold 3: Fixing part, 4: Metal pipe 5: Press machine, 7: Wedge 8: Socket

Claims (3)

(57) [Claims] An end portion of a fiber composite material is inserted into a die casting mold, a low-melting metal is injected into the die, and a cylindrical fixing portion is formed on the outer periphery of the end portion by the low-melting metal. At the same time, the identification attachment part is inserted into the metal pipe, and a pressing force is applied from the outer peripheral surface of the metal pipe by a press machine to the fixing part to form a fixing part with a metal pipe. Fixing the terminal portion of the fiber composite material to the portion to be fixed via the fixing device. 2. A metal fixing member provided with a cylindrical fixing portion formed by injection die casting of a low melting point metal at a terminal portion of a fiber composite material, and a metal pipe inserted and fitted to an identification attachment portion from an outer peripheral surface and compressed. An end fixing device for a fiber composite material, comprising: a fixing unit with a pipe, wherein the terminal portion of the fiber composite material is fixed to a portion to be fixed via the fixing unit with a metal pipe. 3. A terminal portion of the fiber composite material is inserted into a die casting mold, a low melting point metal is injected into the die portion, and a cylindrical fixing portion is formed around the terminal portion with the low melting point metal. At the same time, the identification attachment part is inserted into the metal pipe, and a pressing force is applied from the outer peripheral surface of the metal pipe by a press machine to the fixing part to form a fixing part with a metal pipe. The fiber composite material is characterized in that the fixing portion with the metal pipe is inserted into a socket together with the wedge and the terminal portion of the fiber composite material is fixed to the portion to be fixed by a wedge action while being sandwiched by a plurality of wedges. Terminal fixing method.