A composite crossarm with maintenance position

Abstract

This invention provides a composite crossarm with maintenance positions, comprising: a core rod and integrally formed insulating skirts and an insulating sheath alternately arranged outside the core rod, the insulating sheath being made of silicone rubber; maintenance positions are provided on the outer surface of the insulating sheath, and an anti-slip layer is provided at the maintenance positions; the raw materials of the anti-slip layer, by weight, include: 100 parts polyurethane elastomer, 50-60 parts silica sol-modified silica sand, 8-10 parts additives, and 10-15 parts curing agent. Through the above technical solution, an anti-slip layer is provided on the maintenance positions of the insulating sheath, improving the wear resistance and anti-slip properties of the maintenance positions, thereby improving the durability of the crossarm and the safety of maintenance operations.

Description

Technical Field

[0001] This application relates to the field of crossarm transmission equipment technology, and in particular to a composite crossarm with a maintenance position. Background Technology

[0002] Composite crossarms are widely used devices in power systems, primarily for supporting and protecting transmission lines. Compared to traditional crossarms, they are made using polymer materials.

[0003] When performing maintenance on power transmission line maintenance towers, high-altitude operations are required. Therefore, existing technology's step-on composite crossarms can provide maintenance personnel with a stepping position.

[0004] For example, patent application CN215632091U discloses a stepable composite crossarm, in which the outer surface of the core rod is covered with multiple silicone rubber sheaths and multiple hard resin sheaths. In this design, the length of the hard resin sheaths is only set to be the average foot length to facilitate stepping, without any treatment of the hard resin sheaths. This design lacks anti-slip measures and has poor safety.

[0005] Patent application CN109577736A discloses a UHV (Ultra-High Voltage) composite insulated crossarm that can be stepped on for maintenance. This design also only specifies the length of the silicone rubber skirt and the step-on skirt. The length conforms to the stride length of an adult, facilitating stepping by maintenance personnel. However, this design also lacks any treatment on the composite insulated crossarm, resulting in a lack of anti-slip measures and poor safety.

[0006] Most existing composite crossarms lack maintenance positions, failing to provide a foothold for maintenance personnel. A few crossarms have maintenance positions but lack wear resistance and anti-slip properties, resulting in reduced safety for maintenance personnel working at heights.

[0007] On the other hand, the skirts of composite crossarms are generally made of silicone rubber, while in the existing technology, polymer anti-slip coatings generally use polyurethane as the base material for anti-slip materials. However, due to the poor compatibility between silicone rubber and polyurethane, the adhesion of the polyurethane protective coating after it is applied to the silicone rubber surface is small, which affects the reliability of the maintenance position of the composite crossarm. Summary of the Invention

[0008] The technical problem to be solved by the present invention is that the existing step-on composite crossbeams do not have anti-slip and wear-resistant treatment on the silicone rubber surface, resulting in poor safety.

[0009] To address the aforementioned problems, this invention provides a composite crossarm with an inspection position, comprising: a core rod and integrally formed insulating skirts and insulating sleeves alternately disposed outside the core rod, the insulating sleeve being made of silicone rubber; an inspection position is provided on the outer surface of the insulating sleeve, and an anti-slip layer is provided at the inspection position; the raw materials of the anti-slip layer, by weight, include: 100 parts polyurethane elastomer, 50 to 60 parts silica sol modified silica sand, 8 to 10 parts additives, and 10 to 15 parts curing agent.

[0010] The above technical solution covers the maintenance area at the insulating sheath with an anti-slip layer, improving the wear resistance and anti-slip properties of the maintenance area, thereby enhancing the durability of the crossarm and the safety of maintenance operations. In this solution, polyurethane elastomer, as the base material, provides good elasticity and wear resistance. The addition of silica sol-modified silica sand significantly improves the roughness and wear resistance of the anti-slip layer, thus enhancing the anti-slip effect. This invention improves the compatibility between silica sand and polyurethane elastomer by mixing silica sol-modified silica sand with polyurethane elastomer, ensuring that the silica sand does not separate from the polyurethane elastomer during long-term foot traffic.

[0011] Optionally, the preparation method of silica sol modified silica sand includes: dispersing silica sand in silica sol and soaking it for no less than 2 hours, taking it out after soaking, and drying it in an environment not higher than 70°C to obtain silica sol modified silica sand.

[0012] In the above method, silica sand is dispersed in silica sol, allowing the silica sand particles to be fully immersed in the silica sol so that the silica sol can coat the outer layer of the silica sand particles. After soaking, the silica sand is removed from the silica sol. At this point, the surface of the silica sand particles is covered with a layer of silica sol. Drying removes excess moisture and unbound silica sol from the surface of the silica sand particles, making the silica sol-modified silica sand more stable. Simultaneously, the lower temperature prevents the silica sol from denaturing or decomposing at high temperatures, which would affect the modification effect.

[0013] To improve the weather resistance of the anti-slip layer, the additives may optionally include at least one of antioxidants, flame retardants, and ultraviolet absorbers.

[0014] Optionally, the preparation method of the coating for the anti-slip layer includes:

[0015] Polyurethane elastomer powder is dissolved in a solvent to obtain a polyurethane solution with a solid content of not less than 65%.

[0016] The anti-slip liquid material is obtained by thoroughly mixing silica sol-modified silica sand with polyurethane solution;

[0017] No more than 1 hour before applying the anti-slip liquid to the insulating sheath, the curing agent and the anti-slip liquid are thoroughly mixed to obtain the anti-slip coating.

[0018] To improve the bonding strength between the anti-slip layer and the insulating sheath, as an improvement, an adhesive layer is also provided between the anti-slip layer and the insulating sheath. The raw materials of the adhesive layer include at least silicone rubber powder and polyurethane elastomer powder. Preferably, the mass ratio of silicone rubber powder to polyurethane elastomer powder is 1:0.8 to 1.2.

[0019] To address the issues of poor compatibility and weak adhesion between silicone rubber and polyurethane anti-slip layers in composite crossarms, the above solution incorporates an adhesive layer between the anti-slip layer and the insulating sleeve. This adhesive layer is composed of a mixture of silicone rubber powder and polyurethane elastomer powder. The silicone rubber powder is made of the same material as the insulating sleeve, while the polyurethane elastomer is the main matrix material of the anti-slip layer. This mixing of materials improves the adhesive strength of the adhesive.

[0020] In a further improvement, the raw materials of the adhesive layer also include glass fiber shavings. Preferably, the mass of the glass fiber shavings accounts for no more than 32% of the total mass of the adhesive layer.

[0021] Glass fiber shavings are a high-strength, high-modulus fiber material. They exhibit good compatibility with both silicone rubber and polyurethane. Adding them to the rubber compound layer can significantly improve its strength while maintaining good elasticity and toughness. Furthermore, the addition of glass fiber shavings can enhance the tear resistance and impact resistance of the rubber compound layer, further improving its overall performance.

[0022] More preferably, the structure of the rubber layer, from the insulating sheath to the anti-slip layer, is as follows: silicone rubber compound area, silicone rubber compound-polyurethane mixture area, polyurethane compound area, with glass fiber shavings mixed in the silicone rubber compound-polyurethane mixture area.

[0023] In this design, the silicone rubber compound area serves as a transition layer between the insulating sheath and the compound layer. The silicone rubber compound area maintains good insulation performance and compatibility with the insulating sheath, ensuring a tight bond between the two.

[0024] The silicone rubber-polyurethane blend zone combines the advantages of both silicone rubber and polyurethane, while the addition of glass fiber shavings significantly improves strength and abrasion resistance. The presence of this blend zone allows the rubber layer to maintain good elasticity while possessing higher strength and tear resistance.

[0025] As a transition layer between the anti-slip layer and the adhesive layer, the polyurethane adhesive zone provides good elasticity and wear resistance, ensuring a tight bond with the anti-slip layer while improving the overall durability of the composite crossarm.

[0026] The layered structure design allows the rubber layer to fully utilize the advantages of silicone rubber and polyurethane, while the addition of glass fiber shavings significantly improves the performance of the rubber layer.

[0027] Optionally, the coating density of the anti-slip layer is not less than 1.8 g / cm³. 2 The coating density of the adhesive layer is not less than 0.25 g / cm³. 2 .

[0028] Optionally, the method for coating the anti-slip layer onto the insulating sheath is as follows:

[0029] After cleaning the surface of the insulating sheath, the surface of the insulating sheath is roughened.

[0030] The anti-slip coating is applied to the surface of the insulating sheath, and after drying, a composite crossarm with maintenance positions is obtained.

[0031] A preferred embodiment is to coat the anti-slip layer onto the insulating sheath as follows:

[0032] After cleaning the surface of the insulating sheath, the surface of the insulating sheath is roughened.

[0033] The adhesive layer is coated onto the surface of the insulating sheath;

[0034] The anti-slip coating is applied to the outer layer of the adhesive layer, and after drying, a composite crossarm with maintenance positions is obtained.

[0035] The technical advantages of this application are as follows:

[0036] 1. This invention covers the maintenance area at the insulating sheath with an anti-slip layer, improving the wear resistance and anti-slip properties of the maintenance area, thereby enhancing the durability of the crossarm and the safety of maintenance operations. In the above solution, polyurethane elastomer, as the base material, provides good elasticity and wear resistance. The addition of silica sol-modified silica sand significantly improves the roughness and wear resistance of the anti-slip layer, thus enhancing the anti-slip effect. This invention improves the compatibility between silica sand and polyurethane elastomer by mixing silica sol-modified silica sand with polyurethane elastomer, ensuring that the silica sand does not separate from the polyurethane elastomer during long-term foot traffic.

[0037] 2. Further, in a preferred embodiment, the present invention disperses silica sand in silica sol, allowing the silica sand particles to be fully immersed in the silica sol so that the silica sol can coat the outer layer of the silica sand particles. After soaking, the silica sand is removed from the silica sol. At this point, the surface of the silica sand particles is covered with a layer of silica sol. Drying removes excess moisture and unbound silica sol from the surface of the silica sand particles, making the silica sol-modified silica sand more stable. Simultaneously, the lower temperature prevents the silica sol from denaturing or decomposing at high temperatures, thus affecting the modification effect.

[0038] 3. Further, in the preferred embodiment, this invention addresses the problem of poor compatibility and weak bonding between silicone rubber and the polyurethane anti-slip layer in the composite crossarm. The above embodiment incorporates an adhesive layer between the anti-slip layer and the insulating sleeve. This adhesive layer is composed of a mixture of silicone rubber powder and polyurethane elastomer powder. The silicone rubber powder is made of the same material as the insulating sleeve, and the polyurethane elastomer is the main matrix material of the anti-slip layer. Mixing these materials improves the adhesive strength of the adhesive.

[0039] 4. Further, in a preferred embodiment, the present invention adds glass fiber shavings to the adhesive layer. The glass fiber shavings have good compatibility with both silicone rubber and polyurethane, which can significantly improve the performance of the adhesive layer.

[0040] 5. In a further preferred embodiment, the present invention, through a layered structure design, enables the adhesive layer to fully utilize the advantages of silicone rubber and polyurethane, while the addition of glass fiber shavings significantly improves the performance of the adhesive layer. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of a composite crossarm with a maintenance position according to an embodiment of the present invention.

[0042] Figure 2 yes Figure 1 Enlarged view of point a in the middle.

[0043] Figure 3 This is a schematic diagram of the anti-slip layer installation at the inspection position of the composite crossarm in an embodiment of the present invention.

[0044] Figure 4 This is another schematic diagram of the anti-slip layer setting at the inspection position of the composite crossarm in an embodiment of the present invention.

[0045] Figure 5 This is another schematic diagram of the anti-slip layer setting at the inspection position of the composite crossarm in this embodiment of the invention.

[0046] Explanation of reference numerals in the attached figures:

[0047] 1. Core rod; 2. Insulating skirt; 3. Insulating sheath; 4. Rubber layer; 5. Anti-slip layer; 401. Glass fiber shavings; 41. Silicone rubber compound area; 42. Silicone rubber compound-polyurethane mixing area; 43. Polyurethane compound area; 51. Silica sol modified silica sand. Detailed Implementation

[0048] The following will be combined with the appendix Figures 1-5 The embodiments of the technical solution of this application are described in detail below. The following embodiments are only used to illustrate the technical solution of this application more clearly, and are therefore only examples and should not be used to limit the scope of protection of this application.

[0049] I. Example of anti-slip coating preparation:

[0050] Silica sand was dispersed in silica sol and soaked for no less than 2 hours. After soaking, it was removed and dried at an environment not exceeding 70°C to obtain silica sol-modified silica sand. The silica sol used in the following examples is M3010 silica sol.

[0051] At 85°C, 100 parts of polyurethane elastomer powder were dissolved in DMF solvent to obtain a polyurethane solution with a solid content of not less than 65%.

[0052] The anti-slip liquid material is obtained by thoroughly mixing 50 to 60 parts of silica sol modified silica sand, polyurethane solution and 8 to 10 parts of additives consisting of antioxidants, flame retardants and ultraviolet absorbers.

[0053] No more than 1 hour before applying the anti-slip liquid to the insulating sheath 3, 10 to 15 parts of curing agent are thoroughly mixed with the anti-slip liquid to obtain the anti-slip coating.

[0054] Example 1-1

[0055] S11. Disperse 50 parts of silica sand in 60 parts of M3010 silica sol and soak for 2 hours. After soaking, take it out and dry it at 65°C to obtain 51.2 parts of silica sol modified silica sand.

[0056] S12. Dissolve 100 parts of polyurethane elastomer powder in 40 parts of DMF solvent to obtain 140 parts of polyurethane solution with a solid content of about 71%.

[0057] S13. After thoroughly mixing 51.2 parts of silica sol-modified silica sand, 140 parts of polyurethane solution, 3 parts of antioxidant, 3 parts of flame retardant, and 2 parts of ultraviolet absorber, the anti-slip liquid material is obtained.

[0058] S14. No more than 1 hour before applying the anti-slip liquid to the insulating sheath 3, mix 15 parts of curing agent with the anti-slip liquid to obtain the anti-slip coating.

[0059] Examples 1-2

[0060] The difference between Examples 1-2 and Examples 1-1 lies in the different control conditions for each step, as detailed in Table 1.

[0061] Comparative Example 1-1

[0062] The difference between Comparative Example 1-1 and Example 1-1 is that the silica sand used in Comparative Example 1-1 was not modified, as detailed in Table 1.

[0063] Table 1

[0064]

[0065] II. Example of adhesive layer preparation:

[0066] As shown in Figure 3, the raw materials of the rubber layer 4 include at least silicone rubber powder and polyurethane elastomer powder. Preferably, the mass ratio of silicone rubber powder to polyurethane elastomer powder is 1:0.8 to 1.2. The preparation of this rubber layer includes: dissolving 100 parts of silicone rubber powder and 80 to 120 parts of polyurethane elastomer powder in DMF solvent at 85°C to obtain a rubber compound with a solid content of not less than 70%. In the following examples, the silicone rubber used is type 110-2 methyl vinyl silicone rubber.

[0067] like Figure 4 The preferred embodiment is as follows: at 85°C, 100 parts of silicone rubber powder and 80 to 120 parts of polyurethane elastomer powder are dissolved in DMF solvent, and glass fiber shavings are added and thoroughly mixed to obtain a rubber compound with a solid content of not less than 70%, wherein the mass of glass fiber shavings 401 accounts for no more than 32% of the total mass of the rubber compound layer 4.

[0068] like Figure 5 A more preferred embodiment is shown in the diagram: the structure of the rubber layer 4, from the insulating sheath 3 to the anti-slip layer 5, consists of: a silicone rubber compound area 41, a silicone rubber compound-polyurethane mixing area 42, and a polyurethane compound area 43, wherein the silicone rubber compound-polyurethane mixing area 42 is mixed with glass fiber shavings 401.

[0069] The preparation method is as follows:

[0070] Preparation of silicone rubber compound liquid: At 85°C, 100 parts of silicone rubber powder are dissolved in DMF solvent to obtain a compound with a solid content of not less than 70%;

[0071] Preparation of silicone rubber compound-polyurethane mixture liquid: At 85°C, 100 parts of silicone rubber powder and 80 to 120 parts of polyurethane elastomer powder are dissolved in DMF solvent, and glass fiber shavings are added and thoroughly mixed to obtain a compound with a solid content of not less than 70%, wherein the mass of glass fiber shavings accounts for no more than 32% of the total mass of the compound layer 4.

[0072] Preparation of polyurethane adhesive: At 85°C, 80 to 120 parts of polyurethane elastomer powder are dissolved in DMF solvent to obtain an adhesive with a solid content of not less than 70%.

[0073] Example 2-1

[0074] Dissolve 100 parts of silicone rubber powder and 80 parts of polyurethane elastomer powder in 75 parts of DMF solvent to obtain a silicone rubber-polyurethane adhesive with a solid content of about 70%.

[0075] Examples 2-2 to 2-3

[0076] The only difference between Examples 2-2 and 2-3 and Example 2-1 is that the control conditions for each step are different, as detailed in Table 2.

[0077] Examples 2-4

[0078] The difference between Examples 2-4 and Examples 2-1 to 2-3 is that Examples 2-4 also contain glass fiber shavings, as detailed below:

[0079] 100 parts of silicone rubber powder and 100 parts of polyurethane elastomer powder were dissolved in 75 parts of DMF solvent, and 65 parts of glass fiber shavings were added and mixed thoroughly to obtain a silicone rubber-glass fiber-polyurethane adhesive with a solid content of 73%, wherein the mass of glass fiber shavings accounted for 31.5% of the total mass of non-volatile substances.

[0080] Examples 2-5

[0081] The difference between Examples 2-5 and Examples 2-4 is that the control conditions for each step are different, as detailed in Table 2.

[0082] Table 2 Control conditions for each step in Examples 2-1 to 2-5

[0083]

[0084]

[0085] Examples 2-6

[0086] The difference between Examples 2-6 and Examples 2-1 to 2-5 is that the adhesive is a layered composite adhesive, specifically including:

[0087] Preparation of silicone rubber compound: Dissolve 100 parts of silicone rubber powder in 40 DMF solvent to obtain a compound with a solid content of 71%;

[0088] Preparation of silicone rubber-polyurethane mixed adhesive liquid: The preparation method is the same as that used in Examples 2-4 for preparing silicone rubber-glass fiber-polyurethane adhesive liquid.

[0089] Preparation of polyurethane adhesive: 100 parts of polyurethane elastomer powder were dissolved in 40 parts of DMF solvent to obtain an adhesive with a solid content of 71%.

[0090] 3. Apply an anti-slip layer to the surface of the insulating sheath 3:

[0091] One implementation method is to clean the surface of the insulating sheath 3 and then roughen the surface of the insulating sheath 3.

[0092] After applying the anti-slip layer 5 to the surface of the insulating sheath 3 and drying it, a composite crossarm with maintenance positions is obtained.

[0093] The preferred implementation method is as follows:

[0094] After cleaning the surface of the insulating sleeve 3, the surface of the insulating sleeve 3 is roughened.

[0095] Apply the adhesive layer 4 to the surface of the insulating sheath 3;

[0096] After applying the anti-slip layer 5 to the rubber layer 4 and drying, a composite crossarm with maintenance positions is obtained.

[0097] In the above embodiments, the coating density of the anti-slip layer 5 is not less than 1.8 g / cm³. 2 The coating density of adhesive layer 4 is not less than 0.25 g / cm³. 2 .

[0098] Example 3-1

[0099] After cleaning the surface of the insulating sheath 3, the surface of the insulating sheath 3 is roughened so that the surface roughness is not less than Ra 6.3μm;

[0100] The anti-slip coating obtained in Example 1-1 was applied to the surface of the insulating sheath 3, with a coating density of 1.8 g / cm³. 2 After drying, a composite crossarm with maintenance positions is obtained.

[0101] Example 3-2

[0102] The difference between Example 3-2 and Example 3-1 lies in the different control conditions for each step, as detailed in Table 3.

[0103] Example 3-3

[0104] After cleaning the surface of the insulating sheath 3, the surface of the insulating sheath 3 is roughened so that the surface roughness is not less than Ra 6.3μm;

[0105] The adhesive obtained in Example 2-1 was coated on the surface of the insulating sheath 3 at a density of 0.25 g / cm2.

[0106] The anti-slip coating obtained in Examples 1-2 was applied to the adhesive layer 4, with a coating density of 1.8 g / cm³. 2 After drying, a composite crossarm with maintenance positions is obtained.

[0107] Examples 3-4 to 3-9, Comparative Example 3-1

[0108] The difference between Examples 3-4 to 3-9, Comparative Examples 3-1 and Example 3-3 lies in the different control conditions for each step, as detailed in Table 3.

[0109] Comparative Example 3-2: No anti-slip layer was installed at the maintenance position.

[0110] Table 3 Control conditions for each step in Examples 3-1 to Comparative Examples 3-2

[0111]

[0112] like Figures 1-2 This illustration shows a composite crossarm with a maintenance position provided by the present invention. The composite crossarm with a maintenance position includes: a core rod 1 and an integrally formed insulating skirt 2 and an insulating sleeve 3 arranged alternately outside the core rod 1. The insulating sleeve 3 is made of silicone rubber. The outer surface of the insulating sleeve 3 is provided with a maintenance position, and an anti-slip layer 5 is provided at the maintenance position.

[0113] Mechanical performance tests were conducted on the maintenance positions of the composite crossarms obtained in Examples 3-1 to 3-2.

[0114] The friction coefficient test method was carried out in accordance with the national standard GB / T 9263-2020.

[0115] The adhesive bonding strength test method is as follows: A 5cm × 5cm molded block of the insulating sheath 3, adhesive layer, and anti-slip layer in the inspection area is cut with a blade. On the peel test platform, the insulating sheath substrate is fixed at one end, and the anti-slip layer is fixed at the other end. The plate is slowly tightened and continuously stretched to perform a tensile peel test. The adhesive cracking is observed and recorded to evaluate the adhesive strength value. The adhesive strength test results are shown in Table 4.

[0116] The silica sand peel strength test is used to test the bonding force between silica sand and polyurethane. Since the bonding force between silica sand and polyurethane is necessarily less than the tensile strength of polyurethane, the peeling of silica sand and polyurethane can be determined by observing the sudden change in tensile force of the anti-slip layer. The test method is as follows: cut a 5cm×5cm anti-slip layer block with a blade, stretch it continuously on the peel test platform, and perform a tensile peel test. Observe the peeling situation between silica sand and polyurethane. The silica sand peel strength test results are shown in Table 4.

[0117] Table 4. Mechanical properties of the maintenance positions of the composite crossarms with maintenance positions obtained in Examples 3-1 to Comparative Examples 3-2.

[0118]

[0119] By comparing the above embodiments 3-1 to 3-9 with comparative example 3-2, it can be seen that the above embodiments have an anti-slip layer 5 at the maintenance position, which can significantly improve the friction coefficient of the maintenance position.

[0120] By comparing Examples 3-1 to 3-9 and Comparative Example 3-1, it can be seen that using silica sol to modify silica sand can significantly improve the compatibility and bonding ability between silica sand and polyurethane.

[0121] A comparison of Examples 3-1 to 3-2 and Examples 3-3 to 3-9 shows that setting an adhesive layer between the anti-slip layer and the insulating sleeve can significantly improve the adhesion of the anti-slip layer to the insulating sleeve.

[0122] A comparison of Examples 3-3 to 3-5 and Examples 3-6 to 3-7 above shows that adding glass fiber shavings to the adhesive can further improve the adhesion of the anti-slip layer to the insulating sheath.

[0123] A comparison of Examples 3-3 to 3-7 and Examples 3-8 to 3-9 above shows that setting the adhesive as a layered adhesive can further improve the bonding force of the anti-slip layer on the insulating sheath.

[0124] The composite crossarm with maintenance position obtained according to the above embodiments of the present invention can be adjusted by those skilled in the art according to relevant standards and regulations by adjusting the crossarm dimensions to meet the requirements of the following voltage levels and tower types:

[0125] 35kV: portal tower, U-shaped tower;

[0126] 110kV: Portal tower, U-shaped tower;

[0127] 220kV: Portal tower, U-shaped tower, V-shaped tower;

[0128] 330kV: Portal towers, V-shaped towers;

[0129] 500kV: Portal tower.

[0130] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A composite cross arm having an access location, the cross arm comprising: The utility model relates to a composite cross arm, including: a core rod (1) and an integrally formed insulating umbrella skirt (2) and insulating sheath (3) arranged outside the core rod (1), the material of the insulating sheath (3) is silicone rubber; an inspection site is arranged on the outer surface of the insulating sheath (3), and an anti-skid layer (5) is arranged at the inspection site; the raw materials of the anti-skid layer (5) include, by mass fraction: 100 parts of polyurethane elastomer, 50-60 parts of silica sol modified silica sand, 8-10 parts of auxiliary agent, and 10-15 parts of curing agent; a glue layer (4) is further arranged between the anti-skid layer (5) and the insulating sheath (3), and the raw materials for preparing the glue layer (4) at least include silicone rubber powder and polyurethane elastomer powder; the structure of the glue layer (4) is sequentially arranged from the insulating sheath (3) to the anti-skid layer (5) as follows: a silicone rubber glue area (41), a silicone rubber glue-polyurethane mixed area (42), and a polyurethane glue area (43), and the silicone rubber glue-polyurethane mixed area (42) is mixed with glass fiber scraps (401); the preparation method of the silica sol modified silica sand includes the following steps: dispersing silica sand in silica sol for not less than 2 hours, taking out after soaking, and drying in an environment of not higher than 70 DEG C to obtain silica sol modified silica sand.

2. The composite cross arm with access locations of claim 1, wherein, the auxiliary agent includes at least one of an antioxidant, a flame retardant, and an ultraviolet absorber.

3. The composite cross arm having an access location of any of claims 1-2, wherein, the preparation method of the coating of the anti-skid layer (5) includes the following steps: dissolving polyurethane elastomer powder in a solvent to obtain a polyurethane solution with a solid content of not less than 65%; mixing silica sol modified silica sand with the polyurethane solution to obtain anti-skid layer liquid material; mixing a curing agent with the anti-skid layer liquid material to obtain anti-skid layer coating within not more than 1 hour before coating the anti-skid layer liquid material on the insulating sheath (3).

4. The composite cross arm having a service location according to claim 1, wherein, the mass ratio of the silicone rubber powder to the polyurethane elastomer powder is 1:0.8-1.

2.

5. The composite cross arm having a service location according to claim 4, wherein, the mass of the glass fiber scraps (401) accounts for not more than 32% of the total mass of the glue layer (4).

6. The composite cross arm having a service location according to claim 1, wherein, The coating density of the anti-skid layer (5) is not less than 1.8 g / cm 2 The coating density of the rubber layer (4) is not less than 0.25 g / cm 2 .

7. The composite cross arm having a service location according to claim 3, wherein, the method for coating the anti-skid layer on the insulating sheath (3) includes the following steps: cleaning the surface of the insulating sheath (3) and performing roughening treatment on the surface of the insulating sheath (3); coating glue of the glue layer (4) on the surface of the insulating sheath (3); coating the anti-skid layer coating on the outer layer of the glue of the glue layer (4), and drying to obtain a composite cross arm with an inspection site.

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