JPS5916035B2 - wire rope - Google Patents

Description

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

In recent years, wire ropes have come to be widely used as motion transmitting parts for printers, XY blocks, various measuring instruments, copying machines, and the like.

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

When such a wire rope is used in a terminal device such as a printer, it is desirable that the wire rope satisfies the following conditions.

In other words, (1) it must have excellent flexibility so that it can be used by bending in any direction, and (2) it must have sufficient springiness, especially in areas where the tensile load is small, so the spring constant must be very high. (3) It should be able to sufficiently withstand tensile or bending stress caused by repeated loading over a long period of time and not elongate, in other words, it should have a long life; (4) It should have a long lifespan, and One of the advantages is that there is no wear due to friction between wire ropes, that is, it has excellent wear resistance.

However, in conventional wire ropes of this type, emphasis is placed on the flexibility described in (1) above, and the spring constant, lifespan, and abrasion resistance required for printers, etc. are neglected, and the results are never satisfactory. It wasn't.

In other words, conventional wire ropes are made from wire rods that have been formed through severe cold processing called wire drawing.
Since these wires are twisted together, the residual stress generated by drawing the wire decreases under the influence of the stress generated by repeated loads during subsequent use, causing the wire to soften and become easily elongated.

Another disadvantage is that conventional wire materials have a small resiliency constant, and elongation increases due to friction due to friction between individual wires, between strands, or between pulleys and wire ropes, which can also cause breakage. was there.

Particularly in recent years, printers and other devices used as terminal devices in information equipment have become faster and faster, so when wire ropes like this are used as movement transmission members for type, the characters may become distorted if the wire rope stretches or wears out. etc., resulting in a decline in print quality.

Therefore, there has been a strong demand for the development of a wire rope that does not have these drawbacks.

The present invention was made in response to such demands.
The wire rope is formed from stainless steel wire, the surface thereof is plated with zinc, and after imparting spring properties directly or by heat treatment, impregnated with oil,
The present invention provides a wire rope that has excellent flexibility, durability, and abrasion resistance due to its extremely simple structure in which the entire wire rope is coated with synthetic resin.

The configuration etc. will be explained in detail below.

The wire rope according to the present invention has a wire diameter of 0.11 to 0.1.
2 mm stainless steel wire is used.

This material has higher mechanical strength than other materials, and its springiness can be greatly improved by heat treatment and straightening, as will be described later.

The surface of this stainless steel wire is plated with zinc (Zn), and the wires are twisted to form a strand, which is further twisted to form a wire rope.

The reason for this Zn plating is that, as a result of experiments, the softness and conformability of Zn reduces the gap between the wires and strands, and increases the strength required for the rope, that is, the spring constant, compared to one without plating. This is because it has been proven.

Figure 1 shows the loads on Zn-plated stainless steel wire rope and conventional bare stainless steel wire rope without plating.
A spring constant diagram is shown, and as is clear from the figure, by applying Zn plating, the spring constant is increased compared to that of a bare stainless steel wire rope.

Furthermore, Fig. 2 shows the elongation of a wire rope when the pulley bending is repeatedly applied, and the elongation of a single wire loaf with Zn plating is smaller than that of a bare stainless steel wire rope even when repeatedly bent.

It was confirmed that by applying Zn plating in this way, the mechanical strength and the lifespan against repeated elongation, which could not be obtained with conventional wire ropes, were improved and the lifespan was also increased.

This is thought to be due to the lubrication, prevention of contact wear, and affinity of the Zn plating layer.

Further, the wire rope plated with Zn as described above is heat-treated in the atmosphere at 300 to 600° C., if necessary.

Generally, when wire rope is twisted at room temperature, residual stress is generated and the twist is reduced, but as a way to prevent this, heat treatment is applied, and as shown in Figure 3, the spring constant of the wire rope decreases compared to the untreated one. It can be increased significantly.

The tension during this heat treatment varies depending on conditions such as the diameter of the rope, the size of the electric furnace, and the temperature, and cannot be determined in general, but it is sufficient if the tension is approximately equal to or lower than the yield point of the rope.

Generally, it is thought that increasing mechanical strength through such heat treatment reduces the flexibility of the wire rope itself, but with stainless steel, the presence of an oxide film formed on the surface of stainless steel , the spring constant is increased as mentioned above and the flexibility is improved.

Furthermore, the oxide film formed on the surface of each material by this heat treatment not only increases the spring constant as described above, but also has the effect of reducing the gaps between the materials and between the strands.

Furthermore, since countless minute pores are formed on the surface of this oxide film, oil, which will be described later, is effectively captured by these pores.

The wire rope with the oxide film formed on its surface 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 traps oil as a lubricating oil in the recessed holes, so wear due to friction between the wires and between the strands is greatly improved. The repeat life can be improved.

The outer layer of the wire rope thus formed is further coated with synthetic resin or braid.

In other words, this resin coating is used to prevent wear caused by friction between the pulley and wire rope when the wire rope is wound around a metal pulley, and also to eliminate slippage and extend the life of the wire rope. .

Next, an example of a method for manufacturing the wire rope configured as described above will be described.

First, the wire diameter is 0.11~0.127M71! 18-8
The surface of the stainless steel wire is plated with Zn, and the stainless steel wire is twisted in a 7x19 twist configuration to form a wire rope with a rope diameter of 1.6 mrn, and this is held under a tension of about 5% of the rope breaking force. The wire rope was continuously heat-treated in an atmosphere at a temperature of 550°C to increase its springiness, and then immersed in a commonly used lubricating oil to impregnate it, and then the entire wire rope was covered with a nylon braid. .

The mechanical strength, spring constant, and life test results of the wire rope thus obtained and the conventional bare stainless steel wire rope are as follows.

As is clear from this table, the wire rope according to the present invention has increased mechanical strength and spring constant, and has significantly improved durability compared to the conventional wire rope.

As explained above, according to the present invention, it has high mechanical strength and spring constant without any loss in flexibility compared to conventional wire ropes, and has increased durability and abrasion resistance due to oil impregnation and resin coating. You can get excellent wire rope.

Therefore, when the wire rope of the present invention is used as a motion transmitting part for terminal devices such as printers and various measuring instruments, which are required to have increased reliability, high speed, and miniaturization in recent years, the effect is extremely low.

[Brief explanation of the drawing]

Figure 1 is a diagram showing the relationship between load and spring constant when the stainless steel wire used in the wire rope of the present invention is galvanized, and Figure 2 is based on a pulley bending test of the same galvanized stainless steel wire. FIG. 3 is a diagram showing the relationship between the number of repeated bending cycles and elongation, and FIG. 3 is a diagram showing the relationship between the heat treatment temperature and the spring constant of a galvanized stainless steel wire.

Claims (1)

[Claims] 1. A wire rope characterized by plating the surface of a stainless steel wire with zinc to form a rope, heat-treating it while applying tension, impregnating it with oil, and coating the entire rope with a synthetic resin. .