Research on Technology of Multilayer Wire Rope
Research on Technology of Multilayer Wire Rope
1 Introduction
The special structure of the wire rope causes the 6-strand or 8-strand wire rope to always have a tendency to rotate, which is the rotation brought about by the special structure of the wire rope. It is theoretically impossible to manufacture 6-strand or 8-strand wire rope into a non-rotating wire rope or a micro-travel wire rope. Even if this effect is achieved, many characteristics of the wire rope itself will be damaged. In addition, it may also be due to the use of tooling or unsuitable production methods during production, which leads to a greater tendency to twist the wire rope (that is, the larger the wire rope) and the rotation of the wire rope. However, many use environments of steel wire ropes require that the steel wire rope does not travel or rotate slightly during use. Therefore, multi-strand steel wire ropes have been developed, and the opposite twisting direction and metal area of the inner and outer layers are used to achieve the purpose of balance. The common methods for evaluating the rotation characteristics of multi-layered steel wire ropes are as follows:
(1) Experimental inspection method. For companies that produce steel wire ropes, there are few equipment that can directly check the rotation performance of steel wire ropes through experiments.
(2) Theoretical calculation. The structure of the wire rope is very complicated, and the calculation of the wire rope torque is also very complicated. It needs to be based on many assumptions, and the accuracy of the calculation is difficult to guarantee;
(3) Calculate by multiplying the area by the twisting radius. The product of the strand area and the distance to the center line of the wire rope can be regarded as the torque. Add the torque of the strands in the same twist direction. The closer the ratio of the two twist directions is to 1, the better the anti-rotation characteristics of the wire rope. This is the reason why the number of strands in the outer layer of the anti-rotation wire rope is 15-18. Through the adjustment of the number of outer layers, the ratio of the metal area of the outer strand to the metal area of the inner strand can be well controlled, and finally the outer layer The strands and the inner strands achieve the best torque balance. It has been very mature to calculate the torque of the inner and outer strands of the multilayer wire rope to achieve the best balance. However, the inner and outer strands of the multi-stranded steel wire rope must be able to restrain each other during actual use to achieve a balanced state, and it must be ensured by the good contact state of the inner and outer strands of the steel wire rope. This article is aimed at researching the contact state of the inner and outer strands of the multi-strand steel wire rope. Through sufficient theoretical analysis and experimental demonstration, a new production technology of the multi-strand steel wire rope is demonstrated, and good results have been achieved.
2. The importance of multi-layer steel wire rope diameter control
To control the rope diameter from the design point of view, the most important thing is whether the reduction should be considered:
(1) If the reduction is considered, the design of the reduction is more reasonable; (2) If the reduction is not considered from the design, but the actual production is impossible without pressing, there is a certain amount of pressing In this way, whether the diameter of the wire rope produced will have a negative tolerance;
(3) It is recommended to maintain a certain amount of reduction. The specific amount of reduction is measured by the production unit according to the actual production situation, and different reductions are given for different structures; (4) The design unit is given according to the production unit The reduction is designed to control the steel diameter tolerance within a certain range. The design of a certain reduction of the steel wire rope is of great significance. It can be seen from Table 1: The inner rope with a length of 500m and a diameter of 118amm has a difference of 2.A5m in the length of the inner rope strands when compressed by 3% and when there is no compression. The 245m inner rope may be the Achilles’ heel of the entire steel rope, and many problems may arise during the use of the rope.
Table 1 Comparative analysis of the rope glue length required for the same length of inner rope with (without) compression. The inner rope production requires the working condition of the gun. The first * bar distance, the length of the strand, the length of the hall% = ss when it is useless, 118 5.647500582). When K compression is 3, 1145.15 7 s00 595.75 If the rope is not compressed, the side effects of the extra 245m inner strands will gradually manifest. It is easy to cause damage to the rope under load, under the conditions of the wheel groove, the thread wheel and the in and out of the reel. In the course of use, the rope diameter changes greatly, even if it is compressed, the rope diameter will also change, but the degree and size of the change are different. Studies have shown that when the rope bears a tension of 3% of the minimum breaking load, the diameter of the steel rope will be smaller than the calculated minimum diameter of the rope. This implies that the gap between the outer strands of the steel rope will completely disappear, and if such a steel rope is put into use, it is prone to damage. There is no gap between the outer casts. During use, the outer casts will support each other. The radial action between the inner rope and the outer casts gradually weakens, and the outer casts are like a void. The same as the tube, with an inner rope in the middle. In this way, the inner rope will bear excess load during use, the length of the inner rope will be further lengthened, and the gauge length of the metal core will be further lengthened, further deteriorating the balance between the inner rope and the outer layer. The rope will soon be damaged.
3 Multi-layer steel wire rope diameter control
3.1 Control the rope diameter from the design
The use environment of steel wire ropes is very complicated, and the equipment of the same type may vary greatly due to the lack of use time, environment or operating habits. Therefore, many steel rope manufacturers start from improving their own personalized design capabilities to meet the needs of users. The ratio of the radius of the wheel groove of the equipment to the diameter of the steel fly is generally Q53. As time goes by, the equipment is continuously damaged, this ratio may continue to decrease, when the ratio is a.5, the number of bending cycles of the wire rope reaches the best.
The ratio of the radius of the wheel groove of the equipment to the diameter of the wire rope is generally 053. However, a misunderstanding is often formed: it is not good to think that the ratio of the round radius to the straightness of the steel rope is 0.53, or the ratio of the radius of the wheel groove to the diameter of the wire rope is 0.53. When the wire rope has the best bending times. However, the design of the diameter of the wire rope must be meaningful when the inner and outer layers of the rope are in good connection and rotation. If only the diameter of the steel division is designed to be small, and the inner and outer layers of the rope are not in a good connection state from the production point of view, the quality and use effect of the steel rope is still difficult to guarantee.
3.2 The influence of the sizing roller on the rope diameter
During the production process, it is necessary to ensure that the inner and outer layers of the rope are closely connected. If the inner and outer strands are separated, the anti-rotation characteristic of the anti-rotation steel rope will be destroyed, and the anti-rotation characteristic of the anti-rotation steel rope will be lost. Therefore, the inner and outer strands must be closely matched and restrained each other to achieve the purpose of torque balance between the inner and outer strands. If there is no interaction between the inner and outer layers, the rotation resistance of the wire rope will be meaningless.
At the head of the rope, the diameter of the steel rope is likely to be too large, especially when the diameter of the steel rope without sizing is larger than the diameter of the steel rope after the sizing roller, which needs attention. It is normal that the diameter measured at the two places before and after the sizing roller differ by 0.2-0.3mm.
The position of the sizing energy is very important. The closer the distance spot is to the tile opening, the better. Because the sizing silver causes the fly diameter to be reduced, the length of the steel rope strands required for the same length of steel rope will be much shorter, that is, the shrinkage rate of the shrinkage is much lower. If the sizing distance is too far from the composite point, this extra rope throw length is difficult to move longitudinally in the direction of the tile mouth. In the end, this extra length is very likely to be distributed throughout the steel rope. Such steel rope is in use Problems are prone to appear in the process. When the sizing roller is placed at the distance from the tile opening, the extra strand length is likely to move toward the tile opening along the longitudinal direction, which can ensure that the pot rope is not prone to problems during use.
3.3 The influence of inner rope tension on rope diameter. During the production of inner rope, the inner rope must have a certain compression rate, so as to ensure the connection state of the inner and outer layers of the steel rope, and also to ensure the diameter control of the steel wire rope. Very good. Compress the inner layer. The elastically compressed part can be tightly attached to the inner rope. At the same time, the compression and straightness control of the outer rope is very good, which can ensure the connection state of the inner and outer layers of the steel rope. In a relatively unhealthy state.
Conclusion
1) The multi-strand steel wire rope is very sensitive to the external environment or load. Therefore, it is very sensitive to the change of the wire rope diameter. The significance of controlling the diameter of the multi-strand steel wire is more than that of the ordinary wire rope:
2) When designing a multi-strand steel rope, the rope diameter of the steel rope can be designed to be smaller, but this is not the fundamental way to solve the multi-strand steel rope. The key is to control the multi-layer cast steel to stand the strength between the inner and outer layers. The connection status of:
3) When in the outbuilding state, apply 10%~20% tension of the minimum breaking drug load to the rope core to ensure the stability of the mud diameter during the use of the steel solution:
4) The multi-layer steel wire lift controls the diameter of the steel wire rope from the design and production of each environment to ensure a good connection state between the inner and outer house ropes. This is the key to controlling the quality of the steel fly.
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