JPS60231009A - Cableway pipe - Google Patents

Abstract

PURPOSE:To improve the transmission efficiency and the wear-proof characteristics by coating the surface of a core wire with flexible and low-friction plastic resin and forming the internal friction face of an external sleeve from another kind of plastic resin which is harder and more flexible than said resin and has 0.2 or less coefficient of friction therebetween. CONSTITUTION:An internal wire 1 consists of a core wire 2 which is coated with plastic resin 3 having the thermoplasticity. The plastic resin 3 has a low friction coefficient and possesses the sufficient flexibility and is made of polyamid such as polyethylene, PTFE, FEP, etc. and polyester such as polyamid, polypropylene, etc. The internal friction face 6 of an external sleeve 4 is made of thermoplastic resin which has relatively high hardness and resilient coefficient with respect to the thermoplastic resin used as the material of the coating of the internal wire 1. The coefficient of the mutual kinetic friction between the plastic resins is 0.20 or less.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cable conduit with significantly improved transmission efficiency.

Conventionally, improved transmission efficiency 2 Feeling during operation
For the purpose of improving corrosion resistance and further preventing rust, the core wire of the cable conduit is coated with plastic coating (M'L), the inner surface of the outer tube of the cable conduit is coated with plastic coating, or the core wire and outer tube are coated with plastic coating. There are known ones in which a plastic tube is interposed between the tube and the tube.

For example, French Patent No. 1,078,061 discloses the use of polyamide, polyurethane and polyethylene in the manner described above, as well as the use of these plastics directly as an outer tube.

In Japanese Patent Publication No. 37-4803, a tube (inner tube) made of super polyamide or the like having a low coefficient of friction is fixed and inserted in at least one place between the core wire and the outer tube (spinning pressure). Aspects are disclosed.

In Japanese Patent Publication No. 54-17864, an example in which oil-impregnated plastic is coated on the core wire is disclosed, and in Japanese Patent Publication No. 48-42924, a plastic tube is coated on the inside of the outer casing. An example of a combination embodiment is disclosed in which the wire is inserted and the core wire is impregnated with a lubricant mainly composed of wax.

The conventional technologies listed above have improved transmission efficiency.

The feeling is also good, especially the Tokuko Showa 54-17864.
The transmission efficiency in Special Publication No. 48-42924 is 80.
~? 0r) has reached 6. Although this efficiency value is extremely high, as the performance of machines, devices, etc. becomes higher, further improvement in efficiency is desired.

The present inventors used a core wire coated with thermoplastic plastic having a low coefficient of friction as an inner cable.

As a result of experiments in which a flexible outer cylindrical tube having a thermoplastic plastic as an inner sliding surface was combined with an inner cable, and a sliding contact mode of a plastinochopranutisoku was carried out,
The present invention was based on the discovery that transmission efficiency and wear resistance can be significantly improved by specially selecting a combination thereof.

In other words, as the thermoplastic plastic to be adhered to the core wire, a plastic having a low coefficient of friction and relatively high flexibility is used, and the thermoplastic plastic that forms the inner sliding surface of the flexible outer cylindrical tube is used. As a plastic, it has higher hardness and elastic modulus than the plastic coated on the core wire.
It has also been found that combinations in which the coefficient of friction between the plastics in the combination is smaller than 0.20 exhibit extremely excellent performance.

Cable conduits are rarely used in a straight line, and are arranged in various curved manners to facilitate movement that involves changing the operating direction and to effectively transmit operating force. It is characterized by the fact that it makes it possible to do the following.

Once the outer cylindrical tube is arranged in a certain manner, it maintains that manner, but the inner cable, which operates by sliding on the inside thereof, is repeatedly bent.

Therefore, if the inner cable is coated with a relatively flexible plastic that has a low coefficient of friction, the inner cable will not become rigid, allowing smooth sliding during one operation, and reducing the loss of operating force. It was expected that the amount of wear would be small, but on the other hand, there was concern that wear would increase because the plastic to which it was applied was flexible.

As a result of various experiments, it was found that although the operating efficiency was as expected, the initial concerns regarding wear were unfounded.

That is, in combination with a flexible plastic on the inner sliding surface of the outer tube and a plastic with a relatively high elastic modulus on the inner cable.

As a result, the glass of the inner cables was significantly worn, and the transmission efficiency was also lower than the value of the above-mentioned combination.

The core wire used in the present invention is a wire lobe with a "7-strand, 6-fold, concentric" configuration, but it is not necessarily limited to this configuration, and wire lobes with other configurations,
In some cases, solid wire such as stainless steel wire or piano wire is used for a certain l/1 core wire.To coat this core wire with thermoplastic, it is extruded using a cross-throated die, but it is also extruded using a fluidized bed immersion method. After applying a plastic dispersion, a film is formed by drying and baking, and a method such as fitting a heat-shrinkable tube is used.

The thickness of the thermoplastic plastic wire lobe may be 0.2 to 0.5 mm out of 10 mm, and the thickness of the thermoplastic plastic wire may be 0 f15 to 0.2 mm out of 10 mm. preferable.

The thermoplastic plastic used for the adhesion has a low coefficient of friction and is highly flexible, such as polyethylene, polytetrafluoroethylene (PTFE), polytetrafluoroethylene hexafluoropropylene (FEP), and 11-nylon. polyamide, polypropylene, and other polyether esters,
Examples include polyesters such as polybutyne/terephthalate. The value of the coefficient of friction must be less than 0.20 (coefficient of dynamic friction) in combination with the thermoplastic plastic that forms the inner sliding surface of the outer cylindrical tube described below. It is.

One embodiment of the flexible outer cylindrical tube of the present invention is a cylindrical tube in which steel wire or steel strips are tightly wound in a spiral manner.

The outer circumferential surface of this cylindrical pipe is usually provided with a protective coating such as polyvinyl chloride or polyethylene, and the inner circumferential surface is made of a thermoplastic selected in relation to the thermoplastic applied to the inner cable described above. are arranged to form a sliding surface.

The plastic sliding surface may be coated on the inner circumferential surface of a spiral tube made of steel by coating, or by tightly wrapping a steel wire or steel strip coated with plastic in a spiral manner. Alternatively, the plastic tube may be formed separately and fitted into the cylindrical tube.

As another embodiment of the flexible outer tube, a relatively thick cheap thermoplastic plastic selected as described above may be used as the soft outer tube.

1. In yet another embodiment, a tube is formed using the thermoplastic plastic selected as described above, and the outer circumferential surface of the tube is reinforced by wrapping a plurality of thin steel wires in a loose pinch. An integrated tube can be used as the outer tube by coating the same or a different thermoplastic on the outside.

The selected thermoplastic plastic mentioned above is a thermoplastic plastic that is relatively harder and has a higher elastic modulus than the T-plastic plastic used for the inner cable, and in the combination of the plastics, The dynamic friction coefficient is smaller than 020.

Table 1 exemplifies thermoplastics with low coefficients of friction used in the present invention. The bending elastic modulus and hardness shown in Table 1 are expressed as comparative model values, with PTFE set at 1. be.

The ○ mark in the "Usage location" column in the table indicates that it is used on the inner cable side or the outer tube side. Among these, polyethylene, polyamide, and polypropylene are used on both the inner cable side and the outer tube side. Ru.

However, if polyethylene is used for the inner cable side, it should be combined with the plastic used for the outer tube side that is listed in the bottom column of Table 9 and has a higher bending elastic modulus and hardness than this plastic. do.

In addition, when polyethylene is used on the outer tube side, PTFE is indicated above the polyethylene.

A combination with FEP shall be adopted.

Regarding poly-1-ethylene, it is preferable to use one having a relatively high molecular weight, since the two molecular weights have a large effect on wear resistance.

Polyamides such as nylon 6, nylon 6-6, nylon 11, and nylon 12 are used as sliding materials, but the physical properties of these materials have relatively large differences. As a polyamide used for the inner cable side.

6-6 nylon and 11-nylon are preferable, and 6-6 nylon is preferable as the polyamide used for the outer tube side.

Polyester is shown in Table 1 as not being used on the inner cable side, but polyester (especially polybutyreterephthalate)
(PBT) is relatively flexible, so it can be used on the inner cord side in some cases.

On the other hand, polyethylene terephthalate (PET)
Since the polyarylate has high rigidity, it is used exclusively on the outer tube side.

Table 2 shows the dynamic friction coefficient (dry friction) for each combination of plastics used on the inner cable side and the outer tube side.

Table 2 The polyamide in the polyethylene-polyamide combination is nylon 6, the polyamide-polyester combination is nylon 11 and PBT, the polyester in the polypropylene-polyester combination is PBT, and the (polyester)-polyacetal combination is PBT. It is an acetal copolymer (trade name: Di-Racon).

Table 5 shows the transmission efficiency and wear amount of the inner rope for each plastic combination, and the test conditions are as described below.

spiral tube Test condition: The cable conduit specimen shown in the figure was bent into a semicircular shape.

Fix each cable end to the operating bar via the load cell of the testing machine, apply a load intermittently to the operating bar, and repeat the pushing and pulling of the inner cable, and attach the load cell to -IJ)
The sliding resistance was measured by measuring the load applied, and the operating efficiency was calculated from this.

(1) Inner cable - 3 mm with 17 main lines 6 concentric configuration
Plastic is coated to a thickness of 0.4 mm on a core wire consisting of wire lobes with a diameter of (3) Clearance between inner cable and outer tube - 0.6 mm (4) Test temperature - Room temperature (15°C) (6) Load - 200 kg (6) Cable curvature - radius of curvature 200 mm 180 degree direction change (7) Push/pull stroke - 30 blades (8) Number of push/pull - 44 times per minute, 50,000 times continuously (9
) Measurement of wear amount - Value of 0I transmission efficiency measured after 50,000 operations - At the end of 50,000 operations, however, Comparative Example 7 is the value in steady state after the start of operation (11) Lubrication - A thin layer of mineral oil is applied at startup. As can be seen from Table 6, all of the specimens made by combining the two inventions had extremely high transmission efficiency.

The amount of wear was also small.

In the comparative examples listed in the same table, the types of plastics were the same, but the combinations were reversed except for 9th example 7.

Both the transmission efficiency and the amount of wear are inferior to the combination of the present invention. In Example 7, the plastic was worn and the core wire was exposed.

As explained above, in the cable conduit of the present invention, the core wire is coated with a highly flexible thermoplastic having a low coefficient of friction, the inner cable is used as the inner cable, and the outer cylindrical pipe is in sliding contact with the inner cable. The inner sliding surface is made of thermoplastic plastic selected in relation to the thermoplastic plastic applied to the inner cable, so it has a high transmission efficiency despite the large load. Not only does it have little wear, it also has a good feeling during operation because it is a plastic-to-plastic sliding contact, and it also has excellent rust prevention properties, which have many practical effects.

In addition to coloring agents, lubricants such as graphite, molybdenum disulfide, wax, and liquid oil can be added to the plastic used in the present invention, and the addition of these lubricants affects operating efficiency and feeling. In addition to contributing to improved wear resistance, it also contributes to improving the wear resistance of plastic sliding parts.

[Brief explanation of drawings]

The figure is a partially longitudinal side view showing an embodiment of the cable conduit of the present invention. 1. Inner cable, 2. Core wire, & thermoplastic, 4° outer tube, 5. Spiral tube made of steel strip, G thermoplastic tube, I fitting, 8, cable end Patent applicant Oiles Industries Co., Ltd.

Claims (1)

[Claims] The inner cable has a core made of steel and has a low coefficient of friction and is coated with highly flexible thermoplastic, and the flexible outer tube has an inner sliding surface made of thermoplastic. The inner cable is combined in sliding contact with the inner sliding surface, and the thermoplastic plastic forming the inner sliding surface is
A cable conduit characterized in that the hardness and elastic modulus are higher than that of the thermoplastic plastic coated on the inner cable, and the coefficient of friction between the plastics in the combination is smaller than 0.20.