A method for deformation-proof reinforcement of a bridge crane contactor moving contact
By using beech wood and a dustproof sealing design in the moving contacts of bridge crane contactors, the problems of moving contact deformation and poor contact have been solved, resulting in improved structural stability, extended service life, and reduced maintenance costs and safety risks.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- YANGCHUN NEW STEEL CO LTD
- Filing Date
- 2026-01-31
- Publication Date
- 2026-06-23
AI Technical Summary
The moving contacts of bridge crane contactors are prone to deformation under high frequency and high temperature environments, resulting in poor contact, high maintenance costs, safety hazards, and poor environmental adaptability.
The moving contact groove is filled with beech wood with a moisture content of 8-10%, and a T-shaped wooden plug is designed and fixed by a freeze assembly method. Combined with a dustproof sealing design and spring stiffness adjustment, a complementary effect is formed to stabilize the contact pressure, and a three-level early warning mechanism is established for maintenance.
It effectively controls the deformation of the moving contact within ±0.1mm, extends the service life to more than 12 months, reduces maintenance costs, improves safety, reliability and environmental adaptability, and has a short investment payback period.
Smart Images
Figure CN122254397A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of steel production technology, specifically to a method for preventing deformation and reinforcing the moving contacts of a bridge crane contactor. Background Technology
[0002] A method for reinforcing and preventing deformation of the moving contacts of bridge cranes is mainly applied to the retrofitting of electrical control systems for cranes under high-frequency, heavy-load conditions in the metallurgical industry. It is particularly effective against contact failures caused by deformation of the moving contacts due to frequent operation and high-temperature environments. Currently, bridge cranes generally use GMC series contactors, which have the following main technical defects: (1) Mechanical structural defects: The existing contactor moving contacts use a single spring pressure structure. Under frequent operation (>300 times / hour), the spring is prone to stress relaxation, resulting in insufficient contact pressure. Test data shows that after three months of continuous operation, the spring pressure of the original structure decreased by 30%.
[0003] (2) Thermal deformation problem: The copper moving contact will undergo thermal deformation when working continuously in a high temperature environment (>60℃). The deformation of the groove part can reach 0.5-1mm, causing contact alignment deviation.
[0004] (3) High maintenance costs: The contactor needs to be replaced 2-3 times a month on average, and each replacement takes 1.5 hours, which affects production efficiency.
[0005] (4) Fault risk: Poor contact at the contact point can cause the control signal to be interrupted, leading to malfunction of the crane and posing a safety hazard.
[0006] (5) Poor environmental adaptability: The existing design does not take into account the dust prevention requirements of the high dust environment in the metallurgical workshop, and the accumulation of dust aggravates mechanical wear. Summary of the Invention
[0007] The purpose of this invention is to provide a method for anti-deformation reinforcement of the moving contact of a bridge crane contactor, so as to solve the problems of mechanical structural defects, thermal deformation, high maintenance costs, failure risks and poor environmental adaptability in the above-mentioned background art.
[0008] To achieve the above objectives, the present invention provides the following technical solution: a method for reinforcing the moving contact of a bridge crane to prevent deformation, wherein the specific process of the reinforcement method is as follows: S1. Failure Mode and Effects Analysis: Disassembly and testing of 30 faulty contactors revealed that 78% had deformed moving contacts, 15% had spring failures, and the remaining 7% were due to other factors. A 3D scanning model was established to quantify the deformation characteristics, identifying the center of the groove as the area of maximum deformation (average deformation of 0.8 mm). S2. Filler Material Screening and Optimization: After comparing the performance parameters of six materials (beech, oak, nylon, PTFE, phenolic resin, and silicone rubber), beech wood with a moisture content of 8-10% was ultimately selected as the filler material. Its coefficient of thermal expansion (5×10⁻⁶) -6 / ℃) and copper contacts (17×10 -6 ( / ℃) to form a complementary effect; S3. Structural Parameter Design: The cork is designed with a T-shaped cross-section, and the head diameter is 0.05-0.1mm larger than the groove to form an interference fit. Three pressure-reducing grooves are cut into the main body, 1.5mm deep and 0.8mm wide, to allow for thermal expansion deformation. S4. Assembly Process Specifications: A cryogenic assembly method is used, placing the cork in a -20℃ environment for 30 minutes before quickly pressing it into the groove. The pressing speed is controlled at 0.5mm / s, with a maximum pressing force ≤200N, ensuring uniform interference fit distribution. S5. Dynamic Performance Testing: A 1 million-cycle mechanical life test is conducted on a simulated operating platform. Test conditions: operating frequency 600 cycles / hour, ambient temperature 70±5℃, relative humidity 40-60%. After the test, the contact resistance at the contact points is measured to be ≤0.5mΩ. S6. Thermodynamic Simulation Analysis: An ANSYS transient thermo-structural coupling model is established to simulate the heat accumulation process during 8 hours of continuous operation. The cork structure is verified to reduce the maximum temperature from 102℃ to 85℃, reducing thermal deformation by 72%. S7. Dustproof Sealing Design: A special silicone grease (model MG-417) is applied to the joint surface between the cork and the groove to form a dust barrier. Simultaneously, a 0.1mm thick polyimide film is added to the exposed end to prevent fiber exudation; S8, Dustproof Sealing Design: The original spring stiffness is adjusted from 8N / mm to 6N / mm, and the initial pressure is reduced from 45N to 35N. Pressure loss is compensated by wooden plug support, so that the effective contact pressure is stabilized within the range of 40±2N; S9, On-site Installation Specifications: A "three-confirmation" installation process is established: confirm the contactor model, confirm the wooden plug specifications, and confirm the pressure test results. After installation, 20 no-load tests are required, and the contact temperature rise ≤30K is considered qualified.
[0009] S10, Maintenance and Monitoring System: Establish a three-tiered early warning mechanism: daily inspection (visual inspection of cork condition), monthly testing (contact resistance), and annual replacement (preventive maintenance). Develop specialized testing fixtures to quickly determine the degree of cork aging.
[0010] Preferably, the three-dimensional scanning in step S1 uses the GOM ATOS Q system with a resolution of 0.03 mm. By comparing the design CAD model with the measured point cloud data, the deformation of each region is calculated. The strain distribution of the groove is analyzed in detail, a temperature-deformation relationship curve is established, and the critical deformation temperature is determined to be 75℃.
[0011] Preferably, the beech wood pretreatment in S2 includes: steam drying (105℃×8h), impregnation with phenolic resin (concentration 12%), and surface polishing (Ra≤1.6μm). The finished product has a density of 0.72g / cm³, a compressive strength of 65MPa, a thermal conductivity of 0.12W / (m·K), and an insulation resistance >100MΩ.
[0012] Preferably, in S3, the diameter of the T-shaped structure head is Φ6.05±0.02mm, the diameter of the handle is Φ4.00±0.01mm, and the total height is 10.00±0.05mm. The pressure-reducing grooves are evenly distributed at 120°, and the bottom of the grooves is rounded with R0.4mm to avoid stress concentration.
[0013] Preferably, in step S4, a dedicated low-temperature chamber (DW-40) is used for the freezing process, with a temperature uniformity of ±1℃. The pressing equipment is a digital display miniature press (HP-50) equipped with a pressure sensor (range 500N, accuracy 0.5%FS). Electrical testing is performed after the assembly has been allowed to recover to room temperature for 2 hours. Preferably, in step S5, the life testing machine conforms to GB / T14048.4-2010 standard and is equipped with a contact resistance tester (MODEL 6290) with a test current of 100A DC. The dynamic contact resistance waveform is recorded every 100,000 cycles, and the bounce time is analyzed (≤3ms is considered acceptable). Preferably, in step S6, the simulation boundary conditions are set as follows: ambient temperature 60℃, convection coefficient 15W / (m²·K), and contact resistance heating power 3.5W. The material parameters are defined as follows: the cork is orthotropic, and the copper contact is a bilinear kinematic reinforcement model. The mesh size is 0.5mm, and the time step is 60s.
[0014] Preferably, the silicone grease in S7 has the following technical parameters: dropping point 280℃, volume resistivity 1×10¹ 4 Ω·cm, evaporation rate (200℃×24h) ≤1%. Polyimide film temperature resistance class H (180℃), dielectric strength 200kV / mm, thickness tolerance ±0.01mm.
[0015] Preferably, the spring material in S8 is replaced with SWOSC-V piano wire, with a diameter of Φ1.2mm, an effective number of coils of 6, and a free length of 25mm. After 3 million fatigue cycles, the pressure attenuation is ≤5%, which is better than the original design (attenuation of 15%).
[0016] Preferably, the installation tools in S9 include a special caliper (6.5mm opening), a torque screwdriver (0.2N·m), and an infrared thermometer (accuracy ±1℃). The acceptance standard refers to GB / T14048.1-2012, with a focus on checking the contact alignment (deviation ≤0.3mm).
[0017] Preferably, in step S10, the detection fixture determines the wear condition by measuring the protrusion of the cork (standard value 2.0 ± 0.1 mm). Aging judgment criteria: replacement is required if the protrusion is <1.8 mm or >2.2 mm. The maintenance cycle is adjusted to 12 months, four times longer than the original system.
[0018] Compared with the prior art, the beneficial effects of the present invention are: (1) Improved structural stability: By using the wood plug filling scheme, the deformation of the moving contact is controlled within ±0.1mm.
[0019] (2) Extended service life: The service life of the contactor is extended from 3 months to more than 12 months.
[0020] (3) Reduced maintenance costs: annual replacement cost savings of RMB 1,200 per unit, and reduced downtime of 36 hours.
[0021] (4) Safety and reliability: Completely eliminate the problem of control signal interruption caused by poor contact of contacts.
[0022] (5) Environmental adaptability: The modification plan must be able to withstand high temperature environment of 60-80℃ and dust conditions.
[0023] (6) Economic feasibility: The cost of a single unit modification is controlled within 50 yuan, and the investment recovery period is less than 1 month. Attached Figure Description
[0024] Figure 1 This is a detailed flowchart of the present invention. Detailed Implementation
[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0026] Please see Figure 1 This invention provides a method for reinforcing the moving contacts of bridge crane contactors to prevent deformation. In this invention, through disassembly and testing of 30 faulty contactors, it was found that 78% of the moving contacts were deformed, 15% were due to spring failure, and the remaining 7% were due to other factors. A three-dimensional scanning model was established to quantify the deformation characteristics, identifying the center of the groove as the area of maximum deformation (average deformation 0.8 mm). The three-dimensional scanning was performed using the GOM ATOS Q system with a resolution of 0.03 mm. By comparing the design CAD model with measured point cloud data, the deformation in each area was calculated. The strain distribution in the groove area was analyzed in detail, and a temperature-deformation relationship curve was established, determining the critical deformation temperature to be 75℃.
[0027] After comparing the performance parameters of six materials (beech, oak, nylon, PTFE, phenolic resin, and silicone rubber), beech wood with a moisture content of 8-10% was ultimately selected as the filler material. Its coefficient of thermal expansion (5×10⁻⁶) is also considered suitable. -6 / ℃) and copper contacts (17×10 -6 The beech wood pretreatment process includes steam drying (105℃×8h), impregnation with phenolic resin (concentration 12%), and surface polishing (Ra≤1.6μm). The finished product has a density of 0.72g / cm³, a compressive strength of 65MPa, a thermal conductivity of 0.12W / (m·K), and an insulation resistance >100MΩ.
[0028] The cork is designed with a T-shaped cross-section, with the head diameter 0.05-0.1mm larger than the groove to create an interference fit. The main body has three pressure-reducing grooves, 1.5mm deep and 0.8mm wide, to allow for thermal expansion and deformation. The T-shaped structure has a head diameter of Φ6.05±0.02mm, a handle diameter of Φ4.00±0.01mm, and a total height of 10.00±0.05mm. The pressure-reducing grooves are evenly distributed at 120° intervals, with a 0.4mm rounded corner at the bottom to avoid stress concentration.
[0029] A cryogenic assembly method was employed, where the cork was placed in a -20℃ environment for 30 minutes and then rapidly pressed into the groove. The pressing speed was controlled at 0.5 mm / s, with a maximum pressing force ≤200 N, ensuring uniform interference fit distribution. A dedicated low-temperature chamber (DW-40) was used for the cryogenic treatment, with a temperature uniformity of ±1℃. The pressing equipment was a digital display miniature press (HP-50) equipped with a pressure sensor (range 500 N, accuracy 0.5%FS). Electrical testing was performed after the cork had been allowed to return to room temperature for 2 hours following assembly. A mechanical life test of 1 million cycles was conducted on a simulated operating bench. Test conditions included: operating frequency of 600 cycles / hour, ambient temperature of 70±5℃, and relative humidity of 40-60%. After the test, the contact resistance was measured to be ≤0.5mΩ. The life testing machine conformed to GB / T14048.4-2010 standard and was equipped with a contact resistance tester (MODEL 6290) with a test current of 100A DC. The dynamic contact resistance waveform was recorded every 100,000 cycles, and the bounce time (≤3ms was considered acceptable) was analyzed.
[0030] A transient thermo-structural coupling model was established using ANSYS to simulate the heat accumulation process during 8 hours of continuous operation. The model verified that the cork structure could reduce the maximum temperature from 102℃ to 85℃, with a 72% reduction in thermal deformation. Simulation boundary conditions were set as follows: ambient temperature 60℃, convection coefficient 15W / (m²·K), and contact resistance heating power 3.5W. Material parameters were defined as follows: the cork was orthotropic, and the copper contacts were modeled using a bilinear kinematic hardening system. The mesh size was 0.5mm, and the time step was 60s.
[0031] Apply special silicone grease (model MG-417) on the joint surface of the cork and the groove to form a dust barrier. At the same time, install a 0.1 mm thick polyimide film at the exposed end to prevent fiber precipitation. Technical parameters of the silicone grease: dropping point 280 °C, volume resistivity 1×10¹ 4 Ω·cm, evaporation amount (200 °C × 24 h) ≤ 1%. The polyimide film has a temperature resistance grade of H (180 °C), dielectric strength of 200 kV / mm, and thickness tolerance of ±0.01 mm.
[0032] Adjust the original spring stiffness from 8 N / mm to 6 N / mm, and the initial pressure from 45 N to 35 N. Compensate for the pressure loss through the cork support to keep the effective contact pressure stable within the range of 40 ± 2 N. The spring material is changed to SWOSC-V piano wire, with a diameter of Φ1.2 mm, 6 effective turns, and a free length of 25 mm. After 3 million fatigue tests, the pressure attenuation ≤ 5%, which is better than the original design (attenuation 15%).
[0033] Formulate a "three-confirmation" installation process: confirm the contactor model, confirm the cork specifications, and confirm the pressure test results. After installation, 20 no-load tests need to be carried out, and it is qualified if the measured contact temperature rise ≤ 30 K. The installation tools include a special caliper (opening 6.5 mm), a torque screwdriver (0.2 N·m), and an infrared thermometer (accuracy ±1 °C). The acceptance standard refers to GB / T14048.1-2012, and the key inspection is the contact alignment (deviation ≤ 0.3 mm).
[0034] Establish a "three-level warning" mechanism: daily inspection (visually check the cork status), monthly test (contact resistance), and annual replacement (preventive maintenance). Develop a special detection fixture to quickly judge the aging degree of the cork. The detection fixture judges the wear status by measuring the protrusion amount of the cork (standard value 2.0 ± 0.1 mm). Aging judgment standard: replace if the protrusion amount < 1.8 mm or > 2.2 mm. The maintenance cycle is adjusted to 12 months, which is 4 times longer than the original system.
[0035] The content not described in detail in this specification belongs to the prior art well-known to those skilled in the art. Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.
Claims
1. A method for reinforcing the moving contact of a bridge crane to prevent deformation, characterized in that: The specific process of the reinforcement method is as follows: S1. Failure Mode and Effects Analysis: Through disassembly and testing of 30 faulty contactors, it was found that 78% of the moving contacts were deformed, 15% of the springs were failed, and the remaining 7% were not. A three-dimensional scanning model was established to quantify the deformation characteristics and determine that the center of the groove was the area with the largest deformation, with an average deformation of 0.8 mm. S2. Filler material selection and optimization: Comparing the performance parameters of six materials—beech wood, oak wood, nylon, PTFE, phenolic resin, and silicone rubber—beech wood with a moisture content of 8-10% was ultimately selected as the filler material, with a coefficient of thermal expansion of 5×10⁻⁶. -6 / ℃ and copper contact 17×10 -6 / ℃ creates a complementary effect; S3. Structural parameter design: The cork is designed with a T-shaped cross section, with the head diameter being 0.05-0.1mm larger than the groove to form an interference fit. The main body has three pressure-reducing grooves, 1.5mm deep and 0.8mm wide, to allow for thermal expansion and deformation. S4. Assembly Process Specifications: The frozen assembly method is adopted. After placing the cork in a -20℃ environment for 30 minutes, it is quickly pressed into the groove. The pressing speed is controlled at 0.5mm / s, and the maximum pressing force is ≤200N to ensure uniform distribution of interference. S5 Dynamic Performance Test: A mechanical life test of 1 million cycles was conducted on a simulated working platform. The test conditions were: operating frequency of 600 cycles / hour, ambient temperature of 70±5℃, and relative humidity of 40-60%. After the test, the contact resistance of the contact points was measured to be ≤0.5mΩ. S6. Thermodynamic Simulation Analysis: A transient thermal-structural coupling model was established using ANSYS to simulate the heat accumulation process during 8 hours of continuous operation, verifying that the wooden plug structure can reduce the maximum temperature from 102℃ to 85℃, with a 72% reduction in thermal deformation. S7, Dustproof and Sealed Design: A special silicone grease, model MG-417, is applied to the joint surface between the cork and the groove to form a dust barrier. At the same time, a 0.1mm thick polyimide film is added to the exposed end to prevent fiber exudation. S8, Dustproof and sealed design: The original spring stiffness was adjusted from 8N / mm to 6N / mm, and the initial pressure was reduced from 45N to 35N. Pressure loss was compensated by using a wooden plug support, so that the effective contact pressure was stabilized in the range of 40±2N. S9. On-site installation specifications: A "three-confirmation" installation process was established: confirm the contactor model, confirm the wooden plug specifications, and confirm the pressure test results. After installation, 20 no-load tests were required, and the contact temperature rise was ≤30K to be considered qualified. S10, Maintenance and Monitoring System: A three-tiered early warning mechanism was established, with daily visual inspections of the cork's condition, monthly testing of contact resistance, and annual replacement to achieve preventative maintenance. Specialized testing fixtures were developed to quickly determine the degree of cork aging.
2. The method for preventing deformation and reinforcing the moving contact of a bridge crane contactor according to claim 1, characterized in that: The three-dimensional scanning in S1 uses the GOMATOSQ system with a resolution of 0.03 mm. By comparing the design CAD model with the measured point cloud data, the deformation of each region is calculated. The strain distribution of the groove is analyzed in detail, and a temperature-deformation relationship curve is established to determine the critical deformation temperature as 75℃.
3. The method for preventing deformation and reinforcing the moving contact of a bridge crane contactor according to claim 1, characterized in that: The pretreatment of beech wood material in S2 includes: steam drying at 105℃ for 8 hours, impregnation with phenolic resin at a concentration of 12%, surface polishing to Ra≤1.6μm, finished product density of 0.72g / cm³, compressive strength of 65MPa, thermal conductivity of 0.12W / m·K, and insulation resistance >100MΩ.
4. The method for preventing deformation and reinforcing the moving contact of a bridge crane contactor according to claim 1, characterized in that: The S3 has a T-shaped structure with a head diameter of Φ6.05±0.02mm, a handle diameter of Φ4.00±0.01mm, and a total height of 10.00±0.05mm. The pressure-reducing grooves are evenly distributed at 120°, and the bottom of the grooves is rounded with R0.4mm to avoid stress concentration.
5. The method for preventing deformation and reinforcing the moving contact of a bridge crane contactor according to claim 1, characterized in that: The S4 freezing process uses a dedicated low-temperature chamber, model DW-40, with a temperature uniformity of ±1℃. The pressing equipment is a digital display micro press, model HP-50, equipped with a pressure sensor with a range of 500N and an accuracy of 0.5%FS. After assembly, the equipment is allowed to recover to room temperature for 2 hours before electrical testing.
6. The method for preventing deformation and reinforcing the moving contact of a bridge crane contactor according to claim 1, characterized in that: The life testing machine in S5 conforms to the GB / T14048.4-2010 standard and is equipped with a MODEL6290 contact resistance tester with a test current of 100ADC. The dynamic contact resistance waveform is recorded once every 100,000 cycles, and the bouncing time is ≤3ms as qualified.
7. The method for preventing deformation and reinforcing the moving contact of a bridge crane contactor according to claim 1, characterized in that: The simulation boundary conditions in S6 are set as follows: ambient temperature 60℃, convection coefficient 15W / m²·K, contact resistance heating power 3.5W, material parameters defined as orthotropic for the cork, bilinear kinematic reinforcement model for the copper contact, mesh size 0.5mm, and time step 60s.
8. A method for preventing deformation and reinforcing the moving contact of a bridge crane contactor according to claim 1, characterized in that: The technical parameters of the silicone grease in S7 are: dropping point 280℃, volume resistivity 1×10¹. 4 Ω·cm, evaporation rate ≤1% at 200℃×24h, polyimide film temperature resistance class H 180℃, dielectric strength 200kV / mm, thickness tolerance ±0.01mm.
9. A method for preventing deformation and reinforcing the moving contact of a bridge crane contactor according to claim 1, characterized in that: The spring material in S8 has been changed to SWOSC-V piano wire with a diameter of Φ1.2mm, an effective number of coils of 6, and a free length of 25mm. After 3 million fatigue tests, the pressure attenuation is ≤5%, which is better than the original design attenuation of 15%.
10. A method for preventing deformation and reinforcing the moving contact of a bridge crane contactor according to claim 1, characterized in that: The installation tools in S9 include a special caliper with an opening of 6.5mm, a torque screwdriver of 0.2N·m, and an infrared thermometer with an accuracy of ±1℃. The acceptance standard refers to GB / T14048.1-2012, with a focus on checking the contact alignment deviation of ≤0.3mm.