JP4704091B2 - Wire rope and control cable - Google Patents

Description

  The present invention relates to a wire rope formed by twisting a plurality of strands and a control cable having the wire rope.

  Currently, wire ropes and control cables are applied in a wide range of industrial fields. Therefore, it is used under various conditions such as on land and sea, high temperature and high load, and the use conditions are severe. A wire rope and a control cable having durability that can withstand such severe use conditions are desired. In particular, a wire rope having high fatigue durability (flexion fatigue durability) when subjected to bending while sliding is desired.

  The inventors of the present invention have already proposed a wire rope and a control that can meet the above-mentioned demands by optimizing the shaping rate and fastening rate of the side strands and the compressive residual stress of the side strands of the side strands in Patent Document 1. Proposed with cable.

However, in recent years, modularization of parts and members has become common in vehicle assembly. For example, when a wire rope is broken, it is necessary to replace a module including the wire rope instead of replacing only the wire rope. It became so. For this reason, the replacement cost has increased, and higher fatigue durability has been demanded than before.
JP 2004-277993 A

  The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a wire rope excellent in bending fatigue durability by improving the prior art (Patent Document 1) and a control cable having the wire rope. And

  When the wire rope is repeatedly bent and stretched with a small bending radius, the core strand and the side strands around the core strand will be misaligned each time the wire is stretched. This misalignment will cause a misalignment between the strand of the core strand and the side strand. The wire comes into contact and wears and breaks. Further repeated bending and stretching breaks the rope. This is due to wear between the strands constituting the rope as described above, and conventionally, oil or grease has been sealed in the wire rope to reduce the friction coefficient between the strands.

  By the way, it is generally known that a combination of strands of dissimilar metals or similar alloys (for example, steel and steel) has a smaller friction coefficient than a combination of strands of the same kind of pure metal. For example, according to the third edition of “Mechanical and Mechanical Mechanics” of Mechanical Engineering Handbook (Showa 54 edition, published by Japan Opportunity Association), the friction coefficient μ between the same kind of pure metals is 0.7 to 1.4. The friction coefficient μ between different metals or the same type of alloys (including steel) is 0.3 to 0.4.

  FIG. 5 schematically shows a cross section of a wire rope having a W (19) + 8 × 7 structure proposed in Japanese Patent Application Laid-Open No. 2004-277993. As is well known, the W (19) + 8 × 7 structure has a Warrington-type twisted structure, and is composed of one core strand 10 composed of 19 strands and eight side strands 20 composed of seven strands. It is the structure of the rope comprised. In addition, the clearance gap 30 between the core strand 10 and the eight side strands 20 which circumscribe is a twist oil adhesion part.

  Specifically, six first side strands 11 are arranged around one core strand 15, and the first side strands 11 are adjacent to each other between adjacent first side strands 11. Six third side strands 13 are arranged so as to be positioned, and six second side strands 12 are arranged between adjacent third side strands. These side strands 11 to 13 are simultaneously twisted in the same pitch and in the same direction, and parallel stranding is performed so that the strands are in line contact with each other. Further, the side strand 20 twists six side strands 21 around the core strand 25. And this side strand 20 is twisted around the above-mentioned core strand 10, and it is set as the wire rope which has the cross section shown in FIG.

  Each element wire is plated, and the element wire (core element wire and first to third side element wires) forming the core strand 20 and the core element wire 25 of the side strand 20 are galvanized (hereinafter referred to as Zn). The side strand 21 of the side strand 20 is a zinc-aluminum alloy plating (hereinafter referred to as Zn-Al alloy plating) steel wire (indicated by ●).

  Zn plating and Zn-Al alloy plating are combinations of different metals, and have a small friction coefficient as described above. Therefore, the sliding between the core strand 10 and the side strand 20 is smooth due to the lubricating action of the twisted oil. However, in one core strand 10 composed of 19 strands, all the strands are subjected to Zn plating, so that the sliding contact between the strands is a combination of pure metals and the friction coefficient is extremely high. That is, when bending and stretching are repeatedly performed with a small bending radius, the strands of the core strand are worn and disconnected, which leads to a rope breakage. That is, in order to further enhance the durability of the wire rope, it has been found that not only the sliding property between the core strand 10 and the side strand 20 but also the sliding property between the strands constituting the core strand must be improved. It was.

  From such knowledge, the present inventors have conceived that the above-described disconnection can be prevented if the strands of the core strands are also a combination of different metals, and as a result of intensive studies, the present invention has been completed.

That is, the wire rope of the present invention has W (19) + 8 × 7, in which eight side strands formed by twisting seven strands are twisted around a core strand formed by twisting 19 strands. in the configuration of the wire rope, the core strands, one and the core wire, a first side wire of six to slide on Shinmotosen, six to sliding contact with the first side element wires adjacent second Zn that is composed of side strands and six third side strands positioned between adjacent second side strands, and that is in sliding contact with the first layer of Zn-plated strands and the first layer. -A multilayer structure having a second layer made of an Al alloy-plated strand, the core strand is made of a Zn-plated strand, and the first layer is made up of a second side strand and a third side strand. Thus, the second layer is characterized by comprising a first side strand.

  In the wire rope of the present invention, the side strand of the side strand is preferably a Zn—Al alloy plated strand.

  As for the wire rope of this invention, it is desirable for the fastening rate of a core strand to be 0.5 to 4%.

  In the wire rope of the present invention, the side strand of the side strand located at the outermost end of the wire rope has a compressive residual stress of 600 MPa or more, and the side strand has a shaping rate of 83 to 103%, Furthermore, it is desirable that the tightening rate is 6 to 10%.

The control cable of the present invention is a control cable having a wire rope and a conduit through which the wire rope is slidably inserted. The wire rope is wound around a core strand formed by twisting 19 strands. A wire rope having a W (19) + 8 × 7 configuration in which eight side strands formed by twisting seven wires are twisted , and the core strand includes a first layer made of a Zn-plated strand and the first layer. A multilayer structure having a second layer made of a Zn—Al alloy-plated wire in sliding contact with the layer.

  The wire rope of the present invention has a multi-layer structure in which a core strand has a first layer made of a Zn-plated strand and a second layer made of a Zn-Al alloy-plated strand that is in sliding contact with the first layer. . Since the sliding contact surfaces of different metals have a small coefficient of friction, they are more slippery than single-layer core strands made of only Zn-plated strands. Therefore, the wire rope is further excellent in fatigue durability than the conventional wire rope, and the control cable having the wire rope of the present invention is also more excellent in durability and has a longer life.

  Moreover, the lifetime extension effect of a wire rope can further be heightened by limiting the fastening rate of a core strand to 0.5 to 4%.

  In the wire rope of the present invention, the side strand of the side strand located at the outermost end portion of the wire rope has a compressive residual stress of 600 MPa or more, and the side strand has a shaping rate of 83 to 103%. When the fastening rate is 6 to 10%, high durability can be stably maintained.

  Below, the best form for implementing the wire rope and control cable of this invention is demonstrated.

[Wire rope]
The wire rope of the present invention is a wire rope having a so-called double twist structure in which a plurality of side strands formed by twisting a plurality of strands are twisted around a core strand formed by twisting a plurality of strands. The core strand has a multilayer structure having a first layer made of a Zn-plated wire and a second layer made of a Zn—Al alloy-plated wire in sliding contact with the first layer. And

  A preferred embodiment of the present invention is shown in FIG. 1 is a schematic cross-sectional view of a wire rope having a W (19) + 8 × 7 configuration as in FIG. 5. Here, the difference between the present embodiment and the prior art shown in FIG. The nineteen strands of the strand 10 have a single-layer structure consisting of only one type of plated strand that is a Zn-plated strand, whereas in the present embodiment the six strands of the core strand 30 The 1 side strand 11a is a Zn-Al alloy plating strand, and the core strand 15, the 2nd side strand 12, and the 3rd side strand 13 are all Zn plating strands. That is, the core strand 30 has a second layer II (first side strand 11a) made of a Zn—Al alloy plated strand on the core portion of the Zn plating (core strand 15), and further a Zn plated second portion II. It has a multilayer structure composed of a combination of two or more types of plated wires in which one layer I (second side strand 12 and third side strand 13) is laminated. Therefore, the sliding contact between the core and the second layer II is a combination of different metals, and the sliding contact between the second layer II and the first layer I is also a combination of different metals. Compared with the core strand 10 which is a slidable contact between the same kind of pure metals (Zn plating), the friction coefficient is remarkably reduced, and the slipperiness between the respective layers is improved. Therefore, it is possible to suppress the occurrence of wire breakage due to wear.

  3 shows a wire rope A (hereinafter referred to as rope A) having a multi-layered core strand (core strand 30) and a wire rope B (hereinafter referred to as rope B) having a single-layered core strand (core strand 10). And (b) load (P) -deflection (δ) diagram. FIG. 3 conceptually shows a load (P) -deflection (δ) diagram, and a solid line a is a load (P) -deflection (δ) diagram of the rope A (hereinafter referred to as diagram a). The dotted line b is a load (P) -deflection (δ) diagram of the rope B (hereinafter referred to as diagram b). As described above, the rope A and the rope B have different core strand configurations, but the other strands, the thickness of each strand, or other components such as the stranding process and the manufacturing conditions are the same. It is a thing.

The load (P) -deflection (δ) diagram of FIG. 3A can be obtained as follows. Taking the diagram b as an example, first, a sample Sb having a predetermined length L is taken from the twisted rope B, and one end c of the sample Sb is fixed as shown in FIG. A load P is applied to the other end d at a constant load speed. Since the rope B is an elastic body, the deflection δ increases in proportion to the increase in the load P (dotted line OQ ₁ ). At a predetermined load _PQ , the deflection becomes _δQ1 , but unloading is started here. The unloading speed is the same as the loading speed in the opposite direction. Since the rope B has internal friction, the restoration does not start simultaneously with the start of unloading. That is, until the load P is unloaded by ΔP _{1, the} deflection δ _Q1 remains constant (dotted line Q ₁ R ₁ ). Thereafter, the deflection δ also decreases in proportion to the decrease in the load P, and the load P becomes 0 at the deflection δ _T1 (dotted line R ₁ T ₁ ). In this way, a diagram b (O → Q ₁ → R ₁ → T ₁ → O) of the rope B can be obtained. Here, after the unloading (even if the load P is set to 0), the deflection δ _T1 remains, but this deflection δ _T1 is a resistance component due to internal friction, and is eliminated with the passage of time and becomes substantially zero. For the rope A, a diagram a (O → Q ₀ → R ₀ → T ₀ → O) can be obtained in the same manner.

When the diagram a and the diagram b are compared, the following (A) to (D) can be understood. (A) When the same load P is applied, the rope A is more bent than the rope B (for example, δ _Q1 <δ _{Q0 in} P _Q ). (A) With the same bending, the load of rope A is smaller than that of rope B (δ _Q1 and P _q <P _Q ). (C) The rope A starts restoration earlier than the rope B (ΔP ₀ <ΔP ₁ ). (D) The rope A is less bent after unloading than the rope B (δ _T0 <δ _T1 ). These phenomena (a) to (d) are caused by the difference in the configuration of the core strands of the rope A and the rope B, and the core strand of the rope A is composed of a Zn-plated strand and a Zn-Al alloy-plated strand. This is because it has a multi-layer structure and has a small friction coefficient on the sliding contact surface and excellent slipperiness.

  The fastening rate of the core strand 30 having such excellent slipperiness is 0.5 to 4%. If the tightening rate is not within this range, a wire rope having sufficient bending fatigue durability cannot be obtained.

  As can be seen from FIG. 4, the rope A (◯) has higher durability than the rope B (Δ) at any tightening rate. And if the fastening rate of the core strand is up to 2%, the durability increases as the fastening rate increases, but thereafter the durability decreases as the fastening rate increases. That is, it is understood that the core strand fastening rate is more preferably 0.9 to 3%. In carrying out this durability test, the fastening rate (%) of the core strand is (calculated outer diameter−actual outer diameter) / calculated outer diameter × 100 at the time of manufacturing the core strand, and the shaping rate of the test rope is The tightening rate was 97% and 7.4%.

  The above-described action of the core strand in the present embodiment can be obtained not only by the wire rope having the W (19) + 8 × 7 configuration shown in FIG. FIG. 2 is a schematic cross-sectional view of a 7 × 7 wire rope. In this configuration, the core strand 40 is composed of one core strand 15 a and six side strands 11 in the same manner as the side strand 20. Here, if the core strand 15a is a Zn-Al alloy plated strand and the six side strands 11 are Zn plated strands, the core strand 15a is the second layer II and the side strand 11 is the first strand. A multi-layer structure that is one layer I can be formed. Therefore, the friction coefficient at the sliding contact surface between the core element wire and the side element wire can be reduced as compared with the conventional single-layer structure including only the Zn-plated element wire, and a highly durable wire rope can be obtained.

  The Zn—Al alloy plating layer having good sliding properties with Zn plating preferably contains 1 to 20 wt% of aluminum, more preferably 2 to 15 wt%. When it consists of two or more side strands, Zn-Al alloy plating may be applied to at least the outermost side strand. By applying the Zn—Al alloy plating, the corrosion resistance of the wire rope can be improved.

  As a method for performing Zn-Al alloy plating, a method conventionally used, such as a method of dipping a steel wire (base material) before drawing into a molten alloy plating bath (dipping), an electroplating method, and the like. It's okay. The thickness of the Zn—Al alloy plating layer formed on the base material is 10 to 50 μm, more preferably 20 to 40 μm.

  In addition, when Zn-Al alloy plating is performed on the steel wire (base material) before wire drawing, a Zn-Al-Fe ternary intermetallic compound layer is obtained. Aluminum has the function of increasing the toughness of the intermetallic compound layer, and the hardness and thickness of the Zn—Al—Fe ternary intermetallic compound layer affect the durability of the wire rope. Therefore, the hardness of the Zn—Al—Fe ternary intermetallic compound layer is 90 to 200 Hv, more preferably 100 to 160 Hv, and the thickness is 3 to 15 μm, more preferably 4 to 10 μm. The endurance strength of the processed wire can be improved.

  In the wire rope of the present invention as described above, the configuration and conditions disclosed in Patent Document 1 (Japanese Patent Application Laid-Open No. 2004-277993) are applied to the configuration factors and manufacturing conditions other than the configuration of the core strand. Can do. That is, each strand may be a steel wire used for a normal wire rope, such as a steel wire made of alloy steel such as carbon steel and stainless steel, and the area reduction rate of the strand before and after wire drawing is 90 to 99.5%, more preferably 95 to 99.5%.

  Moreover, the shape of the strand is preferably a round wire having a circular cross section, and the thickness of the strand is not particularly limited. As for the hardness of a strand, Vickers hardness is 600-800Hv, More preferably, it is 670-770Hv.

  The core strand is composed of a plurality of strands that are bundled or twisted, but the inner strand and the outer strand can be cross-twisted when the inner strand and the outer strand are in point contact. It may be a parallel twist that makes line contact or other twists. More preferred is Warrington twist. Since the Warrington twist is a dense twist with a high actual cross-sectional area, it has excellent tensile strength.

  A side strand consists of a core strand and a side strand twisted around the core strand. It consists of two or more layers of side strands, such as twisting another side strand (second side strand) around the side strand (first side strand) twisted around the core strand. Side strands can also be used. When two or more side strands are twisted together, cross-twisting, parallel twisting, or other twisting methods may be used. The number of core strands and side strands is not particularly limited, but it is preferably composed of one core strand and 6 side strands. In the case of a side strand composed of two or more layers of side strands, it is desirable to select a plating composition so that the side strands in sliding contact with other layers are a combination of different metals.

  The twist structure of the core strand and the side strand is not particularly limited as long as it is a twist structure used for a normal wire rope. In addition to twisting a plurality of side strands on one core strand, the same or another type of side strand (second side strand) around the side strand (first side strand) twisted around the core strand The structure which consists of 2 or more side strands may be sufficient like twisting together. Particularly preferred as the twisted structure of the core strand and the side strand is the W (19) + 8 × 7 structure.

  In the wire rope of the present invention, the compressive residual stress of the side strand of the side strand located at the outermost end is 600 MPa or more, more preferably 700 to 1000 MPa. When a side strand consists of two or more layers, the side strand located in the outermost layer becomes the side strand located in the outermost end.

  The side strands have a shaping rate of 83 to 103%, more preferably 91 to 100%. Furthermore, the fastening rate of the wire rope is 6 to 10%, more preferably 7 to 10%.

  If the values of the compressive residual stress, the shaping rate, and the tightening rate of the side strands of the side strands located at the outermost end are not within the above ranges, a wire rope having sufficient bending fatigue durability cannot be obtained.

  Moreover, it is preferable that the wire rope of this invention consists of a strand twisted with the twist oil whose SAE kinematic viscosity grade is # 1000 or less (40 degreeC). More preferably, they are twisted together by # 80 to # 550 twisting oil.

  Furthermore, the surface of the wire rope of the present invention is preferably covered with a resin such as polyethylene, polyamide, or polyacetal resin. By covering the surface of the wire rope with resin, the durability is further improved, and the slidability is improved when the wire rope is inserted into a conduit of a control cable.

[Control cable]
The control cable of the present invention includes the above-described wire rope of the present invention and a conduit that is slidably inserted through the wire rope.

  The conduit may be a conduit having a general structure composed of an outer spring that is obtained by rolling a steel wire or the like into a rectangular cross section and winding it. The conduit may have a structure in which an outer spring is closely wound spirally on a cylindrical liner made of resin. A control cable with a resin liner has good slidability of the wire rope and excellent operability. As the material of the liner, polyethylene, polyacetal resin, polybutylene terephthalate, fluorine resin, or the like is preferable. Further, a resin outer coat may be attached to the outer periphery of the outer spring.

  In the control cable of the present invention, the wire rope preferably slides in the conduit in the pulling direction or the pushing and pulling direction, and is used for operation of various devices such as an accelerator, a throttle, a clutch, a brake, a window regulator and the like of an automobile. .

  Hereinafter, the present invention will be described in more detail with reference to Examples (Rope A) and Comparative Examples (Rope B).

(Sample preparation)
A steel wire (SWRH62A) was prepared as a bus bar. A Zn plating layer (thickness of 30 μm) is formed on the surface of the bus bar by dipping and wire drawing is performed to form the core strands of the core strands, the first (rope B) / second / third side strands and the side strands. A core strand was obtained. The first strand of the core strand (rope A) and the side strand of the side strand are formed by dipping a Zn—Al alloy plating layer (thickness 30 μm) containing aluminum on the surface of the bus. Was drawn. The outer diameter of each strand after drawing was set to the value shown in Table 1. In addition, the area reduction rate of each strand by wire drawing was 97 to 99%, and the hardness was 700 to 750 Hv (see Table 2).

  By combining these strands, a test rope A having a multi-layer structure in which the core strand is a Zn-plated strand and a Zn-Al alloy-plated strand and a test rope B having a single-layer structure in which the core strand is a Zn-plated strand only. And got. The configuration of each rope is W (19) + 8 × 7 configuration.

  At this time, the type of plating of the side strand of the side strand and the first side strand of the core strand of the test rope A, the hardness of the side strand of the side strand, the residual stress, the shaping rate, and the amount of each strand A combination such as a twisted oil viscosity was selected as shown in combination conditions 1 to 17 in Table 2, and a test rope A and a test rope B were produced under the same number of combination conditions. That is, the sample rope A obtained under the combination condition 1 is the sample A01, and the sample rope B obtained in the same manner is the sample B01, and a total of 33 samples of the sample A01 to the sample A17 and the sample B01 to the sample B16 are used. Was made.

  Sample A16 and sample B16 are samples obtained by removing the twisted oil of each test rope prepared under combination condition 16 by ultrasonic cleaning. Sample A17 was obtained by removing all 19 strands of the core strand from Zn-Al alloy plated strands and removing the twisted oil of the test rope by ultrasonic cleaning. Further, the fastening rate of the test rope was 7.4%, and the fastening rate of the core strand was constant at 2%.

(Examination and evaluation)
The above 33 samples were subjected to a bending fatigue endurance test (hereinafter simply referred to as an endurance test) by the method disclosed in Japanese Patent Application Laid-Open No. 2004-277993. The results are shown together in Table 2. Although the sample number is not described in Table 2, for example, the column of the test rope A under the combination condition 1: 250 × 10 ³ times is the endurance test result of the sample A01, and the test rope B under the combination condition 1 Column: 190 × 10 ³ times is the endurance test result of sample B01. Similarly, the column of the test rope A is the endurance test result of each sample A02-17, and the column of the test rope B is the endurance test result of the sample B02-16. In addition, although the endurance test performed the fixed pulley endurance test and the rotation pulley endurance test, it was a result of "no break" about all the samples of the test rope A and the test rope B in the fixed pulley endurance test. Therefore, the durability test results in Table 2 are based on the rotating pulley.

  From Table 2, it can be seen that the test rope A is more durable than the test rope B under all combination conditions. In the particularly preferred combination conditions 1 to 7, it can be seen that the durability of the test rope A is 40,000 to 60,000 times higher than that of the test rope B, and the improvement effect is high. The test rope A exhibited a durability of 180,000 times or more, and in particular, the samples A01, 06, and 07 were able to maintain a stable durability without breaking up to 250,000 times. From these facts, it can be seen that the multi-layering of the core strand greatly contributes to the long life of the wire rope.

  Further, when the twisted oil was removed and only the sliding contact between the strands (combination condition 16), the durability was 30,000 times for sample A16 and 20,000 times for sample B16. This is a result more remarkably indicating that the friction coefficient on the sliding contact surface between the Zn plating and the Zn—Al alloy plating is smaller than the friction coefficient on the sliding contact surface between the Zn platings.

  Further, Sample A17 was obtained by using all the 19 strands of the core strand as Zn-Al alloy plated strands and removing the twisted oil of the test rope by ultrasonic cleaning, but the durability was 30. 1,000 times and that of sample A16. That is, it has been found that if the core strand has a multilayer structure of Zn—Al alloy plating and Zn plating, the life extension effect of the rope can be obtained.

On the other hand, in the case of combination conditions 8 to 12, the test rope A is more durable than the test rope B, but the test rope B obtained under the suitable combination conditions 1 to 7 It was lower than the durability of and was not satisfactory. Moreover, in the case of the combination conditions 13-15, although comparatively high durability (210 * 10 < ³ > times) was obtained, since twist oil dynamic viscosity is as high as # 300- # 1000, there exists a possibility of reducing productivity. It is not suitable for mass production.

The present invention is not limited to the above-described embodiments, and can be modified without departing from the gist of the present invention. The present invention relates to a wire rope formed by twisting a carbon steel-based wire such as a hard steel wire by various plating treatments and forming a combination of different plating layers in each layer of the wire rope . Has been described in conjunction with Zn plating and Zn-Al plating real 施例, in any case the side strands and the core strand, instead of the wire having a different plating layers described above, corresponding to each plating material Material Wires (metal wires) may be used.

  The wire rope and wire cable of the present invention can be suitably used for accelerators, throttles, clutches, brakes, window regulators and the like of automobiles.

It is a cross-sectional schematic diagram of the wire rope A which is one Example of this invention. It is a cross-sectional schematic diagram of the wire rope (7x7) which is the other aspect of this invention. It is explanatory drawing explaining the load-deflection diagram of the wire rope A and the wire rope B. FIG. (A) is a conceptual diagram of a load-deflection diagram, (b) is a schematic diagram of a measuring method. It is a graph which shows the change of durability by the fastening rate of a core strand. It is a cross-sectional schematic diagram of the wire rope B which is a comparative example.

Explanation of symbols

10, 30: Core strand 11: First side strand 12: Second side strand 13: Third side strand 15: Core strand core strand 20: Side strand 21: Side strand side strand 25: Side Strand core wire

Claims (5)

In a wire rope of W (19) + 8 × 7 configuration in which eight strands formed by twisting seven strands are twisted around a core strand formed by twisting 19 strands,
The core strands, one and the core wire, a first side wire of six to sliding contact with the core wire, six to sliding contact with the first side element wires adjacent second Side Element Wire And a third layer of six third- side wires positioned between the adjacent second- side strands, and a first layer made of Zn-plated strands and a Zn-Al in sliding contact with the first layer A multilayer structure having a second layer made of an alloy-plated element wire,
The core wire is made of a Zn-plated wire, the first layer is made of the second side wire and the third side wire, and the second layer is made of the first side wire. A wire rope characterized by   The wire rope according to claim 1, wherein the side strand of the side strand is a Zn-Al alloy plated strand. The wire rope according to claim 1 or 2 , wherein a fastening rate of the core strand is 0.5 to 4%. The side strands of the side strands located at the outermost end of the wire rope have a compressive residual stress of 600 MPa or more, the side strands have a shaping rate of 83 to 103%, and a tightening rate of 6 It is 10%, The wire rope in any one of Claims 1-3 . In a control cable having a wire rope and a conduit that slidably passes through the wire rope,
The wire rope has a W (19) + 8 × 7 configuration in which eight strands are formed by twisting seven strands around a core strand formed by twisting 19 strands. And
The core strand has a multilayer structure having a first layer made of Zn-plated strands and a second layer made of Zn-Al alloy-plated strands in sliding contact with the first layers. Control cable.

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