JPH05125676A - Fatigue-resistant wire rope - Google Patents

Abstract

PURPOSE:To obtain the subject product having improved flexural fatigue resistance, tensile fatigue resistance and shape collapse resistance and high durability by using a multilayer twisted strand obtained by forming gaps between wires of each layer of strand and twisting the wires under a specific condition. CONSTITUTION:A space S is formed between wires 1a to 1e of each layer constituting multilayer twisted strand in such a way that a ratio of the wire space S and diameter da to de of each wire is 2-4%, 19-41 wires 1a to 1e are twisted in parallel so that twisting length L of strand is 5 to 6 times as long as a strand diameter D to give multilayer twisted strand 1 and the plural strands 1 are twisted to give the objective product.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dynamic rope for a cargo handling machine such as a crane or a hoist, a construction machine, an elevator or the like, and a fatigue resistant wire rope suitable as a support rope. is there.

[0002]

2. Description of the Related Art The wire rope shown in FIG. 2 (JIS standard G3525) is shown as a typical example of the conventional moving rope.
Will be described. A Warrington seal type multi-layer formed by twisting six strands 11b, 12 strands 11c, d, and 12 strands 11e around a strand (core) 11a. IWRC6 × WS, which has twisted strands 11 and is formed by twisting six strands 11 around a wire rope core (IWRC) 12 having a 7 × 7 structure.
It has a rope structure of (31) and its strand 1
A very small space between the strands is formed between the strands of each layer of No. 1, and the strand twist length L0 is 7.5 to 8.5 times the strand diameter D0.

[0003]

As a conventional moving rope wire rope, a rope having the above-mentioned structure is generally used. Due to an increase in the diameter of the sheave and a decrease in the diameter of the sheave, the fluctuation range of the tension and bending load applied to the wire rope becomes large, causing early fatigue disconnection, and the reduction of the diameter of the winding drum and the number of winding layers. Due to the increase, wire ropes are rubbed against each other and lose their shape, causing breakage, etc., and improvements in bending fatigue resistance, tensile fatigue resistance, and deformation resistance have become issues. ..

The present invention was developed in order to address the above-mentioned problems, and its purpose is to improve bending fatigue resistance, tensile fatigue resistance, deformation resistance and the like. And to provide a fatigue resistant wire rope with improved durability.

[0005]

According to the present invention, in a wire rope constituted by twisting a plurality of multi-layer twisted strands, the strands have a ratio of 2 <strand gap and strand diameter between strands of each layer. <4% space between strands is formed, and the strand twist length is 5 to 6 with respect to the strand diameter.
By doubling and constructing by twisting 19 to 41 strands into parallel strands, fatigue resistance as well as deformation resistance and the like are effectively improved.

[0006]

In a wire rope formed by twisting a plurality of multi-layer twisted strands, the strand twist length is appropriately shortened to 5 to 6 times the strand diameter to obtain 19 to 41 strands. The strands are twisted in parallel with each other to form a structure that is relatively rigid and difficult to lose shape even when subjected to strong pressure, and that stress is evenly distributed, which is basically flexible and fatigue-resistant. By forming a space between strands of 2 <strand gap and strand diameter <4% between the strands of each layer, it effectively reduces fatigue breakage due to internal wear and secondary bending, and is excellent overall. Bending fatigue resistance, tensile fatigue resistance, and deformation resistance have been obtained.

[0007]

EXAMPLE An example of the strand of the present invention is shown in FIGS. 1 (A) and 1 (B), and the strands are twisted together to form FIG.
The structure is a fatigue resistant wire rope having the structure shown in FIG. In the figure, 1 is a strand, 1a, 1b, 1c, 1d, 1
e is a wire constituting the strand 1, da, db, dc, dd, d
e is the diameter of each strand (each diameter of the strands 1a to 1e), S
Is the strands 1b, 1c and 1d of each layer of the strand 1, and 1
Space (gap) between the strands formed between e, D
Is the strand diameter (outer diameter of strand 1), L is the strand twist length (1 twist pitch of strand 1),
As shown in FIG. 1, six strands 1b, 1 are provided around the strand 1a.
It has a multilayer twisted strand 1 of 1 + 6 + (6 + 6) +12 structure formed by twisting two wires 1c and 1d and 12 wires 1e, and a wire rope of 7 × 7 structure as shown in FIG. In a wire rope in which six strands 1 are twisted around a core (IWRC) 12 to form an IWRC6 × WS (31) structure, the strand 1 has two wires 1b, 1c and 1d of each layer, and 1e. <The ratio of the wire gap to the wire diameter is <4% and the space S between the wires is formed, and the strand twist length L is 5 to the strand diameter D.
It is a fatigue-resistant wire rope characterized by being formed by twisting the strands 6 to 6 times and twisting 19 to 41 strands 1a to 1e in parallel.

As shown in FIG. 1 (A), the space S between the strands formed on the strand 1 is the strand 1 at the outermost layer.
Supposing that the wire gap of e is S and the wire diameter is de, 2 <the ratio of wire gap S and wire diameter de (= S × 100 / de
) <4%, and in the next layer, the wires 1c and 1d are formed.
Based on the average value of the element wire diameters dc and dd, the space S between the element wires is formed between the element wires of the next layer and the innermost layer in the innermost layer based on the element wire diameter db of the element wire 1b. .. further,
The fatigue-resistant wire rope is set to have an appropriately long rope twist length in accordance with setting (shortening) of the strand twist length L of the strand 1 as described above.
A non-rotating wire rope with a small torque coefficient, manufactured by twisting together into a normal twist to improve the quality and reliability of the rope and adjusting the rotation force of the rope.

In the fatigue wire rope of the present invention, as described above, each strand 1 forms the inter-strand space S between the strands of each layer with a ratio of 2 <strand gap and strand diameter <4%. In addition, the strand twist length L is 5 to the strand diameter D.
It is characterized by a structure in which 19 to 41 elemental wires 1a to 1e are twisted in parallel by 6 times, and the strand twist length L of each strand 1 is appropriately shortened as described above to make it parallel. By twisting, the strands of the strand 1 are densified and the shape is less likely to be deformed even when subjected to a strong pressure, and the stress is evenly distributed to form a structure that is basically rich in flexibility and fatigue resistance, By the space S between the strands formed as described above between the strands of each layer of the strand, fatigue disconnection due to internal wear and secondary bending is effectively reduced, and bending fatigue resistance and tensile resistance are comprehensively reduced. Fatigue resistance and deformation resistance have been significantly improved, and durability has been greatly improved.

As shown in Table 1, Conventional Example 1 of IWRC 6 × Ws (31) structure, IWRC 6 × Ws (31) formed in different rope structures by changing the strand twist length L and the space S between strands, IWRC
Wires of Examples 1 to 4 having 6 × Fi (29), IWRC 6 × Ws (36), and IWRC 6 × Ws (31) structures, and Comparative Examples 1 to 3 having IWRC 6 × Ws (31) structure The rope was manufactured as a sample and subjected to bending fatigue test, tensile fatigue test and shape collapse test, and the results as shown in Table 2 were obtained. The bending fatigue test is shown in Fig. 3.
As shown in (A), the sample a is hung on the two test sheaves c in an S shape and connected to the auxiliary rope b, and the hydraulic ram d is applied with a load F of 1/6 of the specified breaking load to drive. Repeatedly moving back and forth on the drum e, the relationship between the number of passes of the test sheave and the number of breaks in the strand is examined, and the tensile fatigue property is
As shown in FIG. 3 (B), one end of each sample (wire rope) a is inclined at 5 °, and a tension of 2 to 7 tf is applied to the sample a at a frequency of 2 Hz for 2 million times. The shape deformation test was carried out by inserting three samples (wire ropes) a into the groove of the sheave g as shown in FIG. 3 (C), and inserting and removing the central sample in the direction of the arrow. This is a test of the wire breakage condition when the wire is pulled in and out a certain number of times.

In the test comparison between the conventional example 1 and the example 1,
Regarding bending fatigue, the number of repetitive cycles until the occurrence of the initial disconnection was 13,000 in Conventional Example 1, but 1.7 in Example 1.
This is about 30% more than 10,000 times, and the number of repeated cycles up to 5% disconnection (9 pieces) in the twist length (1 twist pitch) of the sample (wire rope) is 27,000 times in Conventional Example 1. In Example 1, the number of cycles was 36,000, and the bending fatigue resistance was significantly improved. Moreover, in the case of tensile fatigue property, the conventional example 1 has
The rope broke after 0,000 times and 2 million times, but in Example 1, there was only a break in the wire even after 2 million times. Further, in terms of the shape deterioration, in Conventional Example 1, many breaks occurred from 50 times, whereas in Example 1, only a few breaks occurred at 200 times. Also, substantially the same results are confirmed for Examples 2, 3, and 4.

[0012]

[Table 1]

Further, Examples 1 to 4 and Comparative Example 1 shown in Table 2
As is clear from the results of the comparative tests of ~ 3, in parallel strands, the inter-strand spaces S between the strands of each layer are formed to be 2 <S × 100 / d <4 (%) and It has been confirmed that, by making the strand twist length L 5 to 6 times the strand diameter D, excellent properties in bending fatigue resistance, tensile fatigue resistance, and shape collapse resistance can be obtained.

The fatigue resistant wire rope of the present invention can be applied not only to the illustrated examples and display examples but also to a strand formed by twisting 19 to 41 strands in parallel, and a strand having a strand fiber core and the like. , That strand 6
The present invention can be applied to a wire rope formed by twisting eight to eight strands, and the same action and effect can be obtained.

[0015]

[Table 2]

[0016]

The present invention has the above-mentioned structure.
In a wire rope configured by twisting a plurality of multi-layer twisted strands, the strands form a space between strands of 2 <strand gap and strand diameter <4% between strands of each layer, and By bending the strand twist length 5 to 6 times the strand diameter and twisting the strands in parallel with 19 to 41 strands, bending fatigue resistance, tensile fatigue resistance, and shape collapse resistance are improved. Significantly improved, durability is greatly increased.

[Brief description of drawings]

FIG. 1 is a cross-sectional view (A) and a side view (B) showing an embodiment of a strand of the present invention.

FIG. 2 is a cross-sectional view (A) and a side view (B) showing a conventional example of a wire rope.

FIG. 3 is each side view mechanism diagram (A) to (C) showing each test mechanism of the wire rope.

[Explanation of symbols]

 1a, b, c, d, e strand 1 strand d-da, db, dc, dd, de strand diameter s space between strands D strand diameter L strand twist length

Claims (1)

[Claims] 1. A wire rope formed by twisting a plurality of multi-layer twisted strands, wherein the strands have a space between strands of 2 <strand gap and strand diameter <4% between strands of each layer. And a strand twist length of 5 to 6 times the strand diameter, and 19 to 41 strands are twisted in a parallel twist to form a fatigue resistant wire rope.