Cable suspension composite wire clamp

Abstract

The utility model discloses a cable suspension composite wire clamp which is composed of a supporting plate, a flat steel hoop with a plastic sleeve and a steel wire rope clamping head, and flexible connection of a cable and a steel cable is achieved through bolt combination. During construction, a stable bearing system is formed by pre-tensioning the steel cables, and cable installation is completed synchronously. Compared with a traditional iron tower scheme, the tower construction cost is saved; compared with a direct crossing scheme, the mechanical stress is effectively dispersed through distributed fixation, and the plastic protective layer can reduce the insulating wear risk. The method is especially suitable for 100m-level gully terrains, has the advantages of high construction safety, good dynamic load adaptability, low operation and maintenance cost and the like, and fills the technical blank of cable crossing in medium-span complex terrains.

Description

Technical Field

[0001] This utility model relates to a composite cable suspension clamp, belonging to the field of cable laying technology. Background Technology

[0002] In high-voltage cable transmission projects, terrain adaptability is a key factor influencing the selection of technical solutions and economic efficiency. Currently, conventional technical solutions have significant limitations for different terrain features such as canyons and ditches.

[0003] Canyon crossing solutions typically involve connecting power transmission cables to multiple towers for segmented support to distribute the load. However, tower construction is costly, especially in complex terrain where foundation engineering must address challenges such as soil stability and transportation conditions, resulting in tower costs accounting for 30%-40% of the total construction cost. For example, in the cost per kilometer of a 500kV line in mountainous terrain, tower engineering accounts for over 40%. In gully terrain with a width of approximately 100m, if a tower solution is used, multiple tower sites are required, significantly increasing foundation construction and material transportation costs.

[0004] Direct crossing of small ditches: This method achieves unsupported crossing by increasing cable sag or shortening the span. While reducing initial investment, the cable's sag due to its own weight can easily lead to mechanical stress concentration, potentially causing insulation wear or strand breakage over long-term operation. Studies have shown that under unsupported conditions, extreme weather conditions (such as icing and strong winds) further exacerbate the sag problem in overhead cables, increasing maintenance costs.

[0005] The technical gap in intermediate terrain: gully terrain is characterized by its wide width (around 100m) and moderate depth, making it difficult for existing solutions to balance economy and reliability. If the tower solution is used, the foundation engineering needs to address the loose soil on the gully slopes, requiring pile foundations or reinforcement measures, leading to a surge in costs (e.g., the rock geological adjustment coefficient reaches 3.85 times). Direct crossing, on the other hand, faces the challenge of controlling cable sag. While increasing the cross-section can improve mechanical strength, it sacrifices current carrying capacity and increases material costs.

[0006] Therefore, there is an urgent need for a high-voltage cable trench crossing technology that takes into account economic efficiency, structural stability, and construction feasibility to fill the existing technological gap. Summary of the Invention

[0007] The technical problem to be solved by this utility model is to provide a cable suspension composite clamp to overcome the shortcomings of the prior art.

[0008] The technical solution of this utility model is: a cable suspension composite clamp, the clamp comprising:

[0009] The support plate is made of flat steel and its length is greater than the spacing between two steel cables;

[0010] The flat steel clamp includes two cantilever arms and a U-shaped section. The two cantilever arms are symmetrically connected to the two ends of the U-shaped section. The cantilever arms are fixedly connected to the lower surface of the support plate by the first bolt. The inner diameter of the flat steel clamp matches the outer diameter of the cable.

[0011] The wire rope clamp includes two wire rope clamps, which are symmetrically fixed to the lower surfaces of the two cantilever arms of the flat steel clamp by a second bolt. The diameter of the clamp hole of the wire rope clamp matches the diameter of the steel cable.

[0012] Furthermore, the cable suspension composite clamp also includes:

[0013] The plastic sleeve is installed on the inner side of the flat steel clamp, which is surrounded by the support plate.

[0014] The beneficial effects of this utility model are: compared with the prior art,

[0015] 1) This utility model connects steel cables with wire rope clips and fixes cables with flat steel clamps. After the steel cables are tensioned, they can provide strong support for the cables and prevent cable sag. This avoids the high costs associated with traditional iron tower construction and also avoids the increased operating costs caused by cable sag when using cables to cross directly.

[0016] 2) The support plate, flat steel clamp and wire rope clip of the cable suspension composite clamp of this utility model are all standard parts that are easy to process or readily available, which makes it easy to control costs;

[0017] 3) This utility model protects the cable insulation layer from friction damage by using a plastic sleeve. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the composite cable suspension clamp of this utility model. Detailed Implementation

[0019] To better understand the above technical solutions, the following will provide a detailed description of the technical solutions in conjunction with the accompanying drawings and specific embodiments.

[0020] Implementation Example 1:

[0021] This embodiment provides a method for crossing complex mountainous terrain for transmission lines. The specific implementation steps are as follows:

[0022] Step S01: Anchor point setting

[0023] Two sets of anchor points are installed on the stable slopes on both sides of the gully. Each set of anchor points adopts a deep-buried ground anchor structure with a depth of not less than 3m and is reinforced with concrete. The spacing between anchor points is determined based on the width of the gully and the cable load to ensure uniform stress on the steel cable.

[0024] Step S02: Cable Traction

[0025] Two high-strength galvanized steel cables (6) with a diameter of 18mm and a breaking strength (≥150kN) are simultaneously pulled using a tension-based method. A dual-traction system is used, positioned behind the anchor points on the same side of the gully. A synchronous control system ensures consistent traction speed for the steel cables (6) to prevent deviation or entanglement. The tension of the steel cables (6) is monitored in real-time during traction and controlled within 20%-30% of the rated value.

[0026] Step S03: Secure the cable end

[0027] After steel cable 6 is pulled to the opposite anchor point, a cable suspension composite clamp (structure as follows) is used. Figure 1 (As shown) Secure the cable end. Specific operations include:

[0028] 1. The support plate 1 is horizontally placed between the two steel cables 6. The support plate is made of Q235B flat steel (50mm×5mm) and its length is 200mm longer than the spacing between the steel cables 6.

[0029] 2. The cable 2-1 can be clamped by the flat steel clamp 4, and the optical cable 2-2 can also be clamped at the same time. The inner wall of the flat steel clamp 4 is provided with a 5mm thick EPDM plastic sleeve 3 to prevent the insulation layer of the cable 2-1 from being worn.

[0030] 3. Use wire rope clips 8 to connect the support plate to the steel cable 6, and use 2 sets of stainless steel second bolts 8 to fasten each clip.

[0031] Step S04: Continuous cable fixing

[0032] During the traction and pullback process of cable 6, a set of cable suspension composite clamps is installed every 20m. The tension of cable 6 is dynamically adjusted by a tension machine to ensure that the cable sag meets the design requirements (e.g., maximum sag ≤ 8m). The clamps are installed using a combination of ground pre-assembly and mechanical hoisting to avoid the risks of working at height.

[0033] Step S05: Pre-tensioning of steel cables

[0034] After the cable is secured, steel cable 6 is pre-tensioned in stages:

[0035] 1. In the first stage, load to the design tension (e.g., 40% of the breaking strength of steel cable 6) and hold the load for 10 minutes to eliminate creep;

[0036] 2. In the second stage, the load is applied to the final tension (50% of the breaking force), and precise control is achieved through a hydraulic tensioner;

[0037] 3. Strain gauges were used to monitor the stress distribution of the steel cable 6 to ensure that the non-uniformity was ≤5%.

[0038] Step S06: Anchor point locking

[0039] The tensioned steel cable 6 ends were connected to the anchor point via shackles, secured with double-nut anti-loosening bolts, and injected with anti-corrosion grease. Finally, vegetation was restored around the anchor point to reduce the impact of soil erosion.

[0040] Cable suspension composite clamp structure description as follows Figure 1 As shown, the wire clamp contains the following core components:

[0041] 1. Support plate 1: Flat steel structure, length customized according to the spacing of steel cable 6, surface hot-dip galvanized;

[0042] 2. Flat steel clamp 4: The inner diameter of the U-shaped part matches the outer diameter of the cable (e.g., Φ120mm), the cantilever length is 150mm, and it is connected to the support plate by the first M12 bolt 7;

[0043] 3. Wire rope clip 8: adopts GB / T5976 standard type, clip hole diameter 18mm, and interference fit with steel cable 6;

[0044] 4. Plastic sleeve 3: EPDM material, Shore hardness 70±5, molded and vulcanized to the inner wall of the clamp.

[0045] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the protection scope of the present invention.

Claims

1. A composite cable suspension clamp, characterized in that, The wire clamp includes: Support plate (1), the support plate (1) is a flat steel, and the length of the support plate (1) is greater than the spacing between the two steel cables (6); Flat steel clamp (4), the flat steel clamp (4) includes 2 cantilever arms and a U-shaped part. The 2 cantilever arms are symmetrically connected to the 2 ends of the U-shaped part. The cantilever arms are fixedly connected to the lower surface of the support plate by the first bolt (7). The inner diameter of the flat steel clamp (4) matches the outer diameter of the cable. The wire rope clamp (8) includes two wire rope clamps. The two wire rope clamps (8) are symmetrically fixed to the lower surfaces of the two cantilever arms of the flat steel clamp (4) by the second bolt (5). The diameter of the clamp hole of the wire rope clamp (8) matches the diameter of the steel cable (6).

2. The cable suspension composite clamp according to claim 1, characterized in that, The cable suspension composite clamp also includes: A plastic sleeve (3) is placed on the inner side of the flat steel clamp (4) that is surrounded by the flat steel clamp (4) and the support plate.

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