JPS6399386A - Method for clamping end of polyoxymethylene twised wire - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for end-stopping polyoxymethylene stranded wire that has high strength and elastic modulus and is also excellent in weather resistance. More specifically, the present invention relates to a method for end-stopping a polyoxymethylene stranded wire, in which the ends of the stranded wire are embedded in an adhesive and fixedly molded to form an end-stop portion.

<Prior Art> Conventional ropes or stranded wires are made of metal such as steel, or synthetic resin such as polyamide, polyester, aromatic polyamide, etc., either singly or in combination. Wire ropes made of metal are stronger than those made of synthetic resin, but have the disadvantages of being heavy and prone to rust.On the other hand, wire ropes made of synthetic resin have lower tensile strength. is generally smaller than steel, making it difficult to obtain high-strength ropes.

Therefore, -g should be a material with particularly high strength as a rope material, i.e., nylon or polyester fiber with a tensile strength of 6 to 10 g/d by ordinary multi-step drawing method, or a strength of 20 to 30 g/d. Aramid (bara-phenylene terephthalamide) fibers having the following properties are used. However, in the case of nylon or polyester fibers, the tensile strength is low, so the specific strength (tensile strength/weight per unit length) is smaller than that of steel. On the other hand, in the case of aramid fibers, the fibers are easily damaged by buckling and have poor weather resistance, so it is necessary to cover them with an outer covering (eg, polyethylene, polyester, etc.). This leads to the disadvantage that the manufacturing cost of the rope increases, and even with such a method of covering the rope with an outer jacket, the phenomenon of single thread breakage due to buckling cannot be completely eliminated. Furthermore, these fibers generally have a small denier and must be twisted into a rope from a large number of filaments, which makes the manufacturing process complicated.

In recent years, Japanese Patent Publication No. 6 has been used as a material for new ropes or twisted wires.
Publication No. 0-21989 discloses a plastic made by twisting and assembling large-diameter plastic materials formed by stretching the plastic material while dielectrically heating it to orient and crystallize it to increase its tensile strength and tensile modulus. The rope is revealed.

Further, another manufacturing method using a pressure drawing method using a heating medium is also disclosed. High-strength polyoxymethylene has a specific gravity of only about 5.5 times that of steel, making it lightweight and rust-resistant. The dielectric heating stretching technology itself, which is a manufacturing technology, is disclosed in Japanese Patent Application Laid-Open No. 148616/1982, and is already known as a method for increasing the strength of plastic materials. However, when looking at materials such as ropes or stranded wires, there is a problem in that there is no method for fixing the ends to take advantage of the high strength properties of the materials. When using the conventional eye splice method as a method for fixing the ends, slippage occurs between the polyoxymethylene wires, so the high strength of the material cannot be fully utilized. Other methods of fixing stranded wires include:
There is a socket processing method, in which the end is shaped and fixed with adhesive or the like so that it has a certain shape. Although this method is also common, it cannot be used as is because there is no adhesive that has good adhesive properties for polyoxymethylene.

<Problems to be Solved by the Invention> When polyoxymethylene wires having high strength and high elastic modulus are end-stopped as stranded wires, the conventional eye splice method or socket processing method Peeling occurs at the ends due to slip-through or peeling between the polyoxymethylene wire and the adhesive, and when viewed as a stranded wire, it is difficult to obtain a high strength wire in practice. That is, it has a drawback that the specific strength as a usable stranded wire is low due to slippage at the end stop or peeling.

An object of the present invention is to provide a method for end-stopping stranded wires by adhesion, which is particularly effective when socketing ends.

<Means for Solving the Problems> The present invention involves winding a plurality of steel wires around the twisted polyoxymethylene wires in order to end the twisted wires twisted from high-strength, high-modulus polyoxymethylene wires. This is a method for end-stopping polyoxymethylene strands, which is characterized in that after the steel and polyoxymethylene strands are tied together, they are embedded in an adhesive and fixedly molded to form an end-stop part.

The polyoxymethylene used in the method of the present invention is obtained by a known polymerization method using formaldehyde or trioxane as a raw material. Moreover, either a homopolymer or a copolymer obtained by copolymerizing ethylene oxide or the like may be used.

The high-strength, high-modulus polyoxymethylene wire can be obtained by dielectric heating drawing and/or external heating drawing manufacturing technology. As for its manufacturing technology, for example, Japanese Patent Application Laid-Open No. 57-148616
It is disclosed in the publication No.

By changing the stretching ratio of the unstretched polyoxymethylene body to 8 to 35 times, the tensile strength is 0.5 to 1.7 GPa,
It is possible to change the tensile modulus from 10 to 50 GPa. When used as the stranded wire of the present invention, the tensile modulus is preferably 20 GPa or more. More preferably, the tensile modulus is 30 GPa or more and the tensile strength is 1.4 GPa.
If it is less than a, high physical properties cannot be expected as a stranded wire. Further, polyoxymethylene having a wire diameter of 0.3 to 10 mm can be used. The wire diameter can be arbitrarily selected to some extent depending on the stranded wire to be manufactured.

Stranded wire is usually manufactured by twisting several wires together.

A twisted yarn body is usually formed from 3 to 7 wire rods. There are usually two types of twist: S twist and 2 twist, and either type can be manufactured. It is also possible to further twist a plurality of such twisted wires together. The polyoxymethylene ends are socketed in the present invention.

In the present invention, when processing the end stop, multiple steel wires are wrapped around the twisted polyoxymethylene, the steel and polyoxymethylene strands are fastened, and then the end stop is formed by embedding and fixing with adhesive. It is characterized by the formation of

In general, polyoxymethylene has poor adhesion; for example, even with epoxy adhesive, the adhesive strength is only 10 to 20K.
It's just g/cj. Therefore, if the end is simply fixed by socket processing with epoxy adhesive, the polyoxymethylene will slip through due to poor adhesion. In the present invention, in order to improve adhesiveness, epoxy adhesive and a steel wire with good adhesiveness are used as assisting agents to improve end-stopping efficiency and to complete an effective socket processing method.

The adhesive used in the present invention may be any adhesive as long as it solidifies and maintains a certain shape, but epoxy adhesives are particularly preferred. In the present invention, in order to prevent pull-out, the end-stopping efficiency is improved not by a chemical method of surface modification of polyoxymethylene, but by a method of using steel, which has good adhesion to epoxy.

The steel wire used in the present invention may be any wire that has good adhesion to epoxy, but general iron wire or plated steel wire is preferable. Generally, in the case of steel wire, the adhesive strength with epoxy adhesive is about 100 to 400 kg/c,
The size and required number of steel wires used in the present invention can be determined from the tensile strength of the steel wires and the adhesive strength with the epoxy adhesive. For example, the adhesive strength between steel wire and epoxy adhesive is 100 kg/cn! In this case, if the steel wire has a wire diameter of 1 and the tensile strength of the wire is 150kg/-, the tensile strength of the wire calculated from the cross-sectional area is 118k.
If the length is greater than 11B/100 = 1.18cff1, the steel wire will break first rather than peeling off at the bonded portion. In the case of wire diameter 11, calculated from the adhesive strength with epoxy adhesive: 1.18 / (0
, 1X3.14) = 3.8, that is, 3.8 am or more, it is calculated that when stress is applied, the bonded portion will not peel and breakage will occur. For example, polyoxymethylene strands are
In order to increase 1 ton, if the steel wires are 3.8 cm or more in length, 1000/11B = 8.5, that is, if there are at least 9 steel wires, the breaking strength at that part will be lower than the adhesive strength. In other words, the adhesive strength with the epoxy adhesive exceeds the breaking strength. Of course, the steel wire must be integrally fixed to the polyoxymethylene strands. For example, the first
As shown in the figure, there is a method of physically fastening and fixing a steel wire and a polyoxymethylene stranded wire using, for example, a wire.

In the end-stopping process of stranded wires according to the present invention, whether socket processing is effective or not can be evaluated by measuring the pull-out stress shown below.

The pull-out stress referred to here is determined by the method shown below. That is, as shown in FIG. 1, both ends of a polyoxymethylene stranded wire are socket-processed to form end portions, and then a tensile test is performed. A tensile test is conducted, and the pulling stress is determined from the breaking stress (kg) of the stranded wire at that time or the maximum stress (kg) immediately before the end of the polyoxymethylene stranded wire is pulled out.

<Example> Next, the present invention will be explained in more detail with reference to Examples.

Example 1. Comparative Example 1 Tensile strength 32 kg, tensile modulus 40 GPa, outer diameter 0.5
A stranded wire was produced using a super-stretched wire body of Tsuru's polyoxymethylene homopolymer (Tenatsuku 3010, manufactured by Asahi Kasei Kogyo Co., Ltd.) as a raw material. The twisted wire had a 1×7 configuration, and the ends were processed using this twisted wire. The polyoxymethylene strands were separated into strands, treated with 400 mesh sandpaper, and then cleaned with acetone. Seven steel wires with a tensile strength of 35 kg and a length of 7 cm were wrapped around the polyoxymethylene strands and fixed with the steel wires.

The shape of the socket is 100 inches long, 60 inches at the top, 2 inches at the bottom.
The polyoxymethylene strands processed as described above were placed inside the conical shape, and embedded and hardened with an epoxy adhesive (Araldite, Rapid, manufactured by Ciba Geigy). Do not perform tensile testing 72 hours after curing. In the example according to the present invention, the stranded wire broke at 190 kg, whereas in the comparative example that did not use steel wire, the stranded wire was pulled out from the socket at 80 kg, indicating that the end stop was incomplete. .

<Effects of the invention> A stranded wire made of polyoxymethylene having high strength and high elastic modulus, in which a plurality of steel wires are wound around the stranded polyoxymethylene in order to socket the ends of the stranded wire. After the stranded steel and polyoxymethylene wires are tied together, they are embedded in adhesive and fixedly molded to form an end stop. It is possible to prevent the methylene stranded wire from slipping through from the end, and the high strength and high elastic modulus of polyoxymethylene, which is the constituent material, can be directly expressed as a stranded wire.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the form of a socket processed portion of a sample according to the present invention, in which reference numeral 1 indicates a polyoxymethylene stranded wire, 2
3 is a steel wire, and 3 is an epoxy adhesive.

Claims (1)

[Claims] 1. In order to end the stranded wire twisted from high-strength, high-modulus polyoxymethylene wire, a plurality of steel wires are wound around the twisted polyoxymethylene and the steel and polyoxymethylene wires are twisted together. Method 2 for end-stopping of polyoxymethylene stranded wires, which is characterized by forming end-stop portions by embedding and fixing the strands with adhesive after tying the wires, and that the adhesive is an epoxy adhesive. End-stopping method according to claim 1 characterized by: