JPS584117B2 - wire rope - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a wire rope used as a motion transmitting upper part of various devices such as printers.

In recent years, wire ropes have come to be widely used as motion transmission components in printers, XY plotters, cameras, and various measuring instruments.

By the way, this type of wire rope is generally formed by twisting several wire rods together to form a strand, which is then further Z-twisted or S-twisted.

Conventionally, the wire ropes used in the various devices mentioned above are:
Wires made of hard steel wire, stainless steel copper wire, etc. twisted together are used, and if necessary, those whose outermost layer is coated with synthetic resin or braided wires are used.

When such a wire rope is used in a terminal device such as a printer, it must satisfy the following conditions.

That is, a wire rope for moving a carriage in a printer is wound around a drive pulley, attached to several guide pulleys, and connected to the carriage with a certain tension applied thereto.

Therefore, as the wire rope is driven, repetitive bending loads are applied to the wire rope by these pulleys, so the wire rope must have a high bending fatigue strength that can sufficiently withstand the bending stress caused by this load.

In addition, the desired force must be able to be transmitted with as little force as possible.

That is, since sufficient springiness is required even in a region where the tensile load is low, the spring constant must be large and there is a degree of freedom in the field of use.

Assuming that these conditions are satisfied, the conventional A wire rope made of wire was used.

However, when these wire ropes are subjected to repeated bending loads, they not only become soft and stretch easily, but also when stress is large, wear occurs due to friction between wires, between strands, or between pulleys and wire ropes, resulting in increased elongation. There was a drawback that these wire ropes were easily broken and caused the wire rope to break.

Particularly in recent years, printers and other devices used as terminals in information equipment have become faster and smaller, so wire ropes may stretch or wear out, and wire ropes with low bending stress may not be able to handle high-speed equipment. There has been a demand for the development of high-strength wire ropes that are difficult to miniaturize.

The present invention was made in response to such demands.
By constructing the wire rope with high-strength tungsten wire and copper or copper alloy wire as wire materials, it has a high spring constant, excellent wear resistance and fatigue resistance, and can be used to speed up and downsize armored equipment. The present invention provides a wire rope that can be used in a wide range of applications.

The configuration and the like will be explained in more detail below.

The wire rope according to the present invention can be produced by twisting a tungsten wire having a graphite powder layer on the surface and having a wire diameter of 0.1 mm or less and a copper wire or a copper alloy wire together to form a strand, or by twisting the strands together. It is formed by twisting together a strand of twisted tungsten wire and a strand of twisted copper wire or copper alloy wire (or a composite wire thereof).

Tungsten wire is usually made by making a round bar using a sintering method, swaging it at high temperature, and then drawing it.

Wire drawing is carried out by passing it through a cemented carbide die at a temperature below the recrystallization temperature. At this time, the surface of the tungsten wire is coated with aquadac (carbon powder) as an antioxidant on the surface of the tungsten wire and as a lubricant for the die. The usual method is to cover it with emulsion.

As the wire drawing progresses and the wire diameter becomes thinner, the crystal grains of the tungsten wire generally take on a shape that is elongated in the length direction of the wire, which is known as a "fiber structure."

As a result of work hardening due to wire drawing and the development of this fiber structure, the strength per unit cross-sectional area of tungsten wire increases as the wire diameter becomes thinner.

As shown in Table 1, the tensile strength of tungsten wire is 0.2
The wire diameter is 200 kg/mm2, which is about the same as that of ordinary steel, but when the wire diameter is 0.1 mm or less, the
A line with high intensity of 00 kg/1 or more can be obtained.

Additionally, metals generally lose their ductility as their strength increases, so
It is extremely difficult to process something that requires flexibility, such as a wire rope, but when we actually worked on tungsten wire, we found that it has very good workability.

This is the reason why the present invention uses a tungsten wire with a wire diameter of 0.1 mm or less.

Furthermore, the aqua glue applied to the wire drawing culm described above covers the surface of the tungsten wire as a carbon powder layer even after the wire drawing process.

When inserting tungsten wire into vacuum equipment, this carbon powder layer is removed to clean the surface of the wire. However, the present invention improves the adhesion between strands when forming a wire rope, and the distance between wires when using a wire rope. This carbon powder layer is actively used to prevent friction and wear between the strands and between the wire rope and the pulley.

In this invention, the tungsten wire is combined with copper wire or copper alloy wire when forming the wire rope, in view of the extremely wide range of uses for wire rope. The aim is to improve local wear.

Then, the wire rope thus formed is immersed in oil or coated with oil on its surface, thereby allowing oil to penetrate between the wires and between the strands.

This oil impregnation treatment significantly reduces wear caused by contact friction between wires or strands when the wire rope is subjected to a bending load.

Further, the wire rope thus formed is further coated with a synthetic resin by a technique such as braiding or extrusion resin coating, if necessary.

This synthetic resin coating is effective in preventing wear due to friction between the pulley and wire rope when the wire rope is wound around or attached to a metal pulley, and also to eliminate slippage between the two parts. be.

Next, examples of the present invention will be described.

Tungsten wire with wire diameter 0.1mm and wire diameter 0.1mm
A wire rope was obtained by alternately twisting phosphor bronze wires for a spring into a 7×19 twist configuration, making the rope diameter 1.6 mm, impregnating it with oil, and covering the outermost layer with a nylon braid.

Table 2 shows the results of a comparison of the life characteristics of the wire rope thus obtained and a conventional wire rope made of stainless steel wire formed with a similar structure.

As is clear from this table, it can be seen that the wire rope of the present invention has extremely long life characteristics compared to conventional wire ropes.

When this wire rope was soldered, it showed extremely good solderability.

In this example, an example was shown in which phosphor bronze wires for springs are twisted together, but since various wire materials can be combined with tungsten wires with a wire diameter of 0.1 mm or less and various twisted configurations can be adopted, depending on the usage conditions. The characteristics of composite wire can be utilized.

As explained above, according to the present invention, since a tungsten wire having a graphite powder layer is formed as the main wire material, it has extremely high mechanical strength and life, and can be applied to small diameter pulleys. Equipment can be made smaller.

In addition, the wire rope according to the present invention not only has an extremely high spring constant but also has excellent flexibility, and has improved solderability, electrical conductivity, and local abrasion, resulting in a longer service life.

Therefore, it has a wide range of applications as a motion transmitting component for terminal equipment and various types of Oki-yodo equipment, which are increasingly required to be smaller and more reliable, and its expected effects are extremely large.

[Brief explanation of the drawing]

The figure is a diagram showing the load-spring constant of the wire rope of the present invention and the conventional wire rope.

Claims (1)

[Scope of Claims] 1. A wire rope made by twisting together strands of tungsten wire with a wire diameter of 0.1 mm or less and copper wire or copper alloy wire having a graphite powder layer on the surface. 2. A wire rope made by twisting together strands of tungsten wire with a wire diameter of 0.1 mm or less having a graphite powder layer on the surface, and strands of copper or copper alloy wire.