Structural design specification for 63/20t, span 25.5m, double girder overhead travelling crane

 As a key component of heavy industrial equipment, the 63/20t double girder overhead travelling crane with a span of 25.5m plays a pivotal role in modern manufacturing and logistics. Its structural design is not only related to the efficiency and safety of lifting operations, but also a measure of the level of manufacturing technology. The purpose of this manual is to elaborate the design concept, structural composition, force analysis and material technology and other core contents of the crane, in order to provide a comprehensive and accurate technical reference for the manufacturing, installation, maintenance and operation personnel. Through in-depth discussion of the design details of the main and auxiliary girders, hoisting and operating mechanisms, as well as the arrangement of safety devices and protective measures, it demonstrates its excellent performance and reliability in complex industrial environments.

Crane Overview

Double girder overhead travelling crane, as a leader in heavy machinery and equipment, plays a vital role in industrial production. Their unique structural design allows for excellent performance when lifting and handling heavy loads. The double girder overhead travelling crane has two parallel and sturdy main girders, which are connected by end girders to form a solid frame structure, ensuring that the crane moves horizontally along the length of the plant on a track. This design not only improves the stability of the crane, but also ensures its safety and efficiency when lifting goods.

Main technical indexes and parameters

The main technical specifications and parameters of this crane include a rated lifting capacity of 63/20t, a span of 25.5m, and a lifting height that can be customized according to the actual needs of users, ensuring the flexibility and adaptability of the crane; The work level is A5, indicating that the crane is suitable for frequent use occasions; The operating speed includes lifting speed, trolley operating speed, and crane operating speed, all of which are designed according to actual needs to ensure the efficient operation of the crane; In addition, relevant parameters of the working environment, such as temperature and humidity, were also considered to ensure that the crane can operate stably and reliably in specific environments.

Application Scenario and Demand Analysis

Double girder overhead cranes play a crucial role in large steel mills, heavy machinery manufacturing plants, harbor terminals and other places where heavy goods need to be lifted frequently. In these environments, the performance stability and safety of the crane is crucial. This crane is designed to meet the needs of efficient, safe and stable work. At the same time, considering that different working environments have their own special characteristics, such as high temperature, humidity, corrosion, etc., this design optimizes the crane in a targeted manner. For example, in the high temperature environment, high temperature resistant materials and design are selected; in the humid environment, the anti-corrosion treatment is strengthened. These optimization measures aim to ensure that the crane can operate stably and reliably under various working environments.

Design Principles and Criteria

Design Principles

In the process of crane design, we always adhere to and practice the core design principle of “safety, reliability, economy and high efficiency”. This principle requires us to scientifically and reasonably optimize the structural layout of the crane during the design process, and adopt advanced design concepts and technical means to ensure that the whole machine can still maintain stable and trouble-free operation in the face of the maximum rated load or even overloading and other extreme working conditions, so as to fully guarantee the safety of the operation process. At the same time, we attach great importance to the maintainability and expandability of the equipment, and by anticipating possible future functional requirements and technology upgrade paths, we pre-design the corresponding interfaces and structures, so as to facilitate convenient and efficient maintenance or functional expansion in the future, thus effectively reducing the maintenance costs and potential investment risks of the users in the process of using the equipment.

Standards and Criteria

In this design program, strictly follow and strictly implement the national and industry standards and specifications on crane design, manufacturing, installation, commissioning, use and maintenance of the whole life cycle. These standards and norms cover, but are not limited to, “Crane Design Code” (GB/T 3811), a national standard, which specifies the basic requirements and parameters of various types of cranes in terms of structural design, strength calculations, material selection, manufacturing process, safety protection devices set up, etc.; as well as the “Crane Safety Regulations” (GB 6067), an important industry regulation, which is designed to ensure that Crane safety regulations (GB 6067), an important industry regulation, which aims to protect the safety and reliability of the use of lifting machinery in the process of crane design, manufacturing, installation, commissioning, use and maintenance of cranes and other aspects of the proposed clear safety requirements and operational standards.

List of relevant standards and norms

Name of standard/norm	Serial number	Description/Scope of Application
Crane Design Specifications	GB/T 3811	Provides for all types of cranes in the structural design, strength calculation, material selection, manufacturing process, safety protection device settings and other aspects of the basic requirements and parameters
Safety Regulations for Cranes	GB 6067	The design, manufacture, installation, commissioning, use and maintenance of cranes and other aspects of clear safety requirements and operational standards
_	_	Other national and industry standards and norms related to crane design, manufacture, installation, commissioning, use and maintenance
_	_	(Note: Some of the key standards are listed here and the actual project should cover all relevant standards throughout the life cycle.)

Crane Design Related Standards and Codes Sources

Type of source	Descriptive	Typical example
National standard	Issued by the National Standardization Administration Committee, with nationwide uniformity and mandatory nature	GB/T (recommended standard), GB (mandatory standard)
Industry standard	Formulated by the relevant administrative department of the State Council and reported to the administrative department for standardization of the State Council for the record, with uniformity and norms in a particular industry	Such as machinery industry standard JB, construction industry standard JGJ, etc.
International standard	Developed by the International Organization for Standardization or regional standardization organizations with wide international acceptance and applicability	ISO (International Organization for Standardization), IEC (International Electrotechnical Commission)
Local standards	Developed by the competent administrative department for standardization of provinces, autonomous regions and municipalities directly under the Central Government, and uniformly implemented within the administrative region.	e.g. DBXX (XX is the abbreviation and code name of the province)
Enterprise Standard	Developed by the enterprise itself and implemented uniformly within the enterprise, usually used for internal technical management, quality control, etc.	e.g. Q/XXX (enterprise code)

Structural composition and component design

Main beam structure design

The main beam is the core load-bearing component of a crane, and its structural design has a crucial impact on the performance and stability of the entire crane. In order to meet the lifting requirements under various working conditions, the main beam adopts an advanced box structure, which has the advantages of high strength, high stiffness, and good stability. By using finite element analysis method, the main beam structure is repeatedly optimized to ensure that it can maintain sufficient strength and stiffness under maximum load, effectively avoiding deformation and damage. In order to improve the torsional resistance of the main beam, a reasonable reinforcement plate structure is set inside the main beam. These reinforcement plates not only enhance the overall rigidity of the main beam, but also improve its torsional performance. Meanwhile, considering the long-term service life and wear resistance of the crane, high-strength low-alloy steel is selected as the main beam material, which has high strength and toughness, can withstand large loads, and maintain good durability. In order to further improve the comprehensive mechanical properties of the main beam, the main beam will also undergo heat treatment to eliminate internal stress in the material, improve material uniformity and stability.

Design of secondary beams and end beams

The design of the secondary beam and end beam, as important components connecting the main beam and supporting the operation of the crane, is equally crucial. The auxiliary beam adopts a box shaped structure similar to the main beam to ensure a firm and reliable connection with the main beam. The auxiliary beam provides stable support and load-bearing capacity for the entire crane through its connection with the main beam. In order to ensure a firm and reliable connection between the secondary beam and the main beam, a combination of high-strength bolts and welding is used for their connection. The end beam is welded with steel plates and reinforced internally to improve its load-bearing capacity. At the same time, a wheel set is installed on the end beam to ensure smooth operation of the crane on the track. The design of the wheel set is crucial for the smooth and stable operation of the crane.

Design of lifting mechanism

The lifting mechanism is one of the important components of a crane, responsible for achieving vertical lifting and lowering of materials. According to user needs and actual working conditions, the lifting mechanism can be in the form of an electric hoist or winch, and can be customized in design. The lifting mechanism ensures that the lifting speed meets actual needs through reasonable transmission ratio and motor power design. The design of the transmission ratio considers the efficiency and power performance of the mechanism to ensure that the material can maintain stable speed and acceleration during the lifting process. The design of motor power takes into account factors such as material weight, lifting speed, and frictional resistance of the mechanism to ensure that the motor can provide sufficient power to drive the mechanism to operate normally. At the same time, the lifting mechanism is also equipped with braking devices and limit devices to ensure safety and stability during the lifting process. The braking device can quickly and effectively stop the movement of the mechanism when necessary, while the limit device can limit the range of motion of the mechanism, avoiding excessive stretching or contraction that may cause damage or safety accidents.

Operating mechanism design

The operating mechanism includes the small car operating mechanism and the large car operating mechanism. The small car operating mechanism is responsible for the lateral movement of the crane on the main beam, while the large car operating mechanism is responsible for the longitudinal movement of the crane on the track. By selecting appropriate motors, designing reducers, and arranging wheels, the crane ensures sufficient stability and load-bearing capacity during operation. The selection of motors takes into account the load size and speed requirements of the operating mechanism; The design of the reducer improves the transmission efficiency and reliability of the mechanism through a reasonable gear ratio and structural form; The arrangement of wheels affects the stability of the mechanism and the accuracy of the operating trajectory.

Force Analysis and Calculation

Static force analysis

Static force analysis is to study the mechanical characteristics of the crane when it is subjected to the maximum load, and calculate the stress distribution and deformation through the principle of statics. Using finite element analysis software to refine the modeling of the key components of the crane, such as the main girder, sub girder, end girder and other structures, and set the corresponding material properties, boundary conditions and load conditions. Through simulation, the stress concentration and maximum deformation of each component under maximum static load are predicted to ensure that it meets the requirements of strength and stiffness, and to avoid structural damage due to overloading or irrational design.

Dynamic force analysis

Dynamic force analysis focuses on the impact of dynamic loads on the structure generated during the startup, braking and operation of the crane. Cranes will produce large dynamic load effects due to inertia when starting and braking, while vibration and impact during operation may also lead to an increase in dynamic stresses. Modeling and calculation of cranes through dynamic analysis software should not only consider the structure's own elastic vibration, but also assess its response characteristics and stability under dynamic loads to prevent the occurrence of structural resonance or instability.

Stress and deformation calculation

Based on the results of static and dynamic force analysis, the stress and deformation are calculated in detail. Through finite element analysis or other numerical simulation methods, the stress distribution cloud diagram and deformation shape diagram of each component when it is subjected to the maximum load, as well as the specific numerical results. These data help the designers to judge whether the crane components meet the design requirements, especially whether they can maintain sufficient safety margin when subjected to the ultimate load to ensure the safe and reliable operation of the crane during the whole service life.

Stability and safety assessment

Stability assessment is an important part of the crane design process, through the stability analysis of the overall structure of the crane to assess its ability to resist overturning and slip when subjected to the maximum load. At the same time, combined with the design of safety devices and protective measures, such as anti-tipping devices, anti-slip devices, overload protection devices, etc., to ensure the safety and reliability of the crane in the operation process. In addition, it is necessary to simulate and analyze the possible extreme conditions or misoperation and propose corresponding improvement measures to minimize the potential safety risks.

Material selection and process requirements

Main material selection

As heavy machinery equipment, the structural stability and load-bearing capacity of cranes are crucial. Therefore, there are strict requirements for the selection of main materials in the manufacturing process. Steel is the main structural material of cranes, and high-strength low-alloy steel is usually selected. This type of steel has high tensile strength and yield point, which can ensure that the crane will not experience structural damage when bearing heavy objects. In addition to steel, castings and forgings are also important materials in the manufacturing of cranes. Castings and forgings are commonly used to manufacture complex shaped parts such as gears, bearing seats, etc. To ensure the quality and performance of these parts, high-quality alloy materials should be selected for castings and forgings. These materials have excellent mechanical properties and durability, which can meet the requirements of cranes in various working conditions. All materials must comply with the requirements of relevant standards and specifications, and their quality must be ensured through strict inspection and testing.

Manufacturing process requirements

The manufacturing process requirements include welding process, heat treatment process, mechanical processing process, etc. The welding process needs to ensure reliable weld quality, the heat treatment process needs to improve the comprehensive mechanical properties of the material, and the mechanical processing process needs to ensure the dimensional accuracy and surface quality of each component. Welding, as a key link in the manufacturing process of cranes, directly affects the overall performance and safety of the crane. During the welding process, it is necessary to strictly control the welding parameters, including welding current, voltage, speed, etc., to ensure the quality of the weld seam. Meanwhile, in order to ensure the stability and reliability of the welding process, advanced welding techniques and equipment should also be adopted. Heat treatment process is also an important means to improve the performance of cranes. Heat treatment can eliminate internal stress and impurities in materials, improve their microstructure, and thus enhance their comprehensive mechanical properties. During heat treatment, it is necessary to strictly control parameters such as temperature and time to ensure that the heat treatment effect meets the requirements. In addition to welding and heat treatment, mechanical processing technology is also one of the important factors affecting the performance of cranes. In the process of mechanical processing, it is necessary to strictly control the dimensional accuracy and surface quality of each component to ensure the fitting accuracy and installation accuracy between each component. At the same time, advanced mechanical processing equipment and process technology should be adopted to improve processing efficiency and quality.

Welding and connection process

Welding, as an important link in the manufacturing process of cranes, directly affects the overall performance and safety of the crane in terms of its quality. Strict control of welding parameters and welding quality is required during the welding process to ensure that the strength and toughness of the weld meet the design requirements. Necessary inspections and tests are required for the connecting components to ensure their secure and reliable connection. To achieve this goal, manufacturing companies need to take a series of measures. Firstly, it is necessary to establish strict welding process specifications, clarify welding parameters and operational requirements. This specification should include key parameters such as welding current, voltage, speed, as well as preparation work before welding, quality control during the welding process, and inspection after welding. By standardizing the welding process, the quality of the weld seam can be ensured to be stable and reliable. Secondly, the connection process of the connecting components also needs to be strictly controlled. The connecting components are an important part of the crane, and their connection quality and stability directly affect the overall performance of the crane. Reliable connection methods such as high-strength bolt connections, welding, etc. should be used in the manufacturing process of connecting components. At the same time, necessary inspections and tests must be conducted to ensure that the quality and performance of the connecting components meet the design requirements.

Corrosion prevention and surface treatment

Considering that the crane is exposed to harsh working environments for a long time, it is necessary to carry out anti-corrosion treatment to improve its service life. Anti corrosion treatment includes steps such as sandblasting, rust removal, painting with primer and topcoat. Sandblasting can remove impurities such as dirt and oxide scale from the surface, improving the cleanliness and roughness of the surface; Applying primer can enhance the adhesion and corrosion resistance of the surface; Applying topcoat can further improve the appearance and durability of the surface. At the same time, surface treatment is required for key components to improve their wear resistance and corrosion resistance; Surface treatment techniques such as electroplating or spraying can form a protective film on the surface of key components; Surface modification techniques such as laser quenching or nitriding can improve the hardness and wear resistance of key component surfaces.

Safety devices and protective measures

Limit and anti-collision device

In modern industrial production environments, cranes are important logistics handling equipment, and their safety and reliability are crucial for production efficiency and personnel safety. The limit device is an effective controller to ensure the operating range of the crane, usually installed in key parts such as the drive mechanism, running track, and lifting equipment of the crane. These devices monitor and limit the operating limits of the crane in real time through physical or electronic induction, preventing the crane from deviating from the predetermined track due to operational errors or equipment failures, thereby avoiding safety accidents such as mechanical damage, electrical short circuits, and even personnel injuries caused by collisions with buildings, equipment, or other facilities.

The anti-collision device is an active preventive safety protection system that utilizes advanced technologies such as infrared sensors, laser scanners, and camera monitoring to monitor changes in the surrounding environment of the crane in real time. When it detects that the crane is too close to surrounding personnel, objects, or another crane, it can quickly react, issue alarm signals to remind operators and other relevant personnel, and automatically activate emergency braking programs when necessary, effectively preventing possible collision accidents.

Overload protection device

Overload protection device is a core component of the crane safety management system, which functions to monitor and accurately control the load status of the crane in real time, ensuring that its designed bearing capacity is not exceeded at any time. This device mainly uses high-precision weight sensors for real-time monitoring, which can accurately sense the weight changes of the goods on the lifting equipment and transmit the data to the intelligent control system for processing. Once the control system determines that the load has exceeded the set rated lifting capacity, the overload protection device will immediately activate and take a series of preset safety measures to avoid overload accidents. Common operations include automatically cutting off the power supply or issuing audible and visual alarm signals to alert operators to promptly reduce the load to a safe range.

Electrical safety devices

Electrical safety devices play a crucial role in the overall safety protection system of cranes. In order to prevent safety accidents caused by electrical faults such as leakage and short circuits, leakage protectors are widely installed in the electrical system of cranes. Once a leakage occurs, the leakage protector can quickly detect abnormal current and take measures to cut off the power supply, thereby avoiding the risk of electric shock and fire hazards caused by current leakage. Short circuit protection device is designed for possible short circuit faults in electrical circuits. When overload or short circuit occurs in the circuit, the device can quickly respond and cut off the power supply of the faulty circuit, protecting equipment such as cables and motors from damage. The grounding protection device is set up to ensure the safe grounding state of the crane casing and the metal components connected to it. By reliably connecting the metal parts of the equipment to the grounding grid, in the event of insulation damage or equipment leakage, the grounding protection device can effectively guide the current to flow into the ground, avoiding electric shock injuries to operators.

Maintenance and repair safety measures

In order to ensure the stable and efficient operation of the crane during long-term use, a comprehensive maintenance and overhaul plan must be developed and implemented. When carrying out maintenance and repair tasks, all personnel involved must strictly comply with relevant safety production regulations and operating procedures, always putting safety first. Before maintenance and overhaul, a comprehensive safety assessment and risk analysis of the work environment must be conducted to ensure that the safety conditions of the work area are fully confirmed and addressed. For high-risk activities such as entering confined spaces, using hazardous chemicals, or conducting high-altitude operations, it is necessary to apply for approval and prepare corresponding safety protection measures in advance in accordance with relevant regulations. The waste and pollutants generated during maintenance and repair should be properly disposed of in accordance with national laws and regulations to prevent environmental pollution and ecological damage. At the same time, detailed records and analysis summaries of each maintenance and overhaul are made to form standardized record files, which helps to timely discover hidden dangers and problems in the equipment and take targeted measures to solve them.

Installation and Debugging

Preparation before installation

Before starting the installation of the crane, comprehensive and meticulous preparation work must be carried out to ensure the smooth progress of the installation work and the safe and reliable operation of the final equipment. Firstly, thoroughly clean the installation site, remove any debris or obstacles that may affect the installation work, and ensure that the work area is clean and spacious; Carefully inspect the equipment components, confirm their integrity, and verify whether their quality meets the design requirements, including but not limited to the functionality and durability of major components such as structural parts, electrical components, hydraulic systems, etc; Based on the actual situation, develop detailed installation plans and schedules, clarify various installation steps, personnel arrangements, and safety measures. In addition, it is crucial to provide professional training and safety education to the personnel involved in the installation, so that they can have a deep understanding of the installation process, operating standards, and potential safety risks of the crane, and improve their operational skills and safety awareness.

Installation steps and requirements

The installation steps of a crane cover multiple key links, including foundation construction, equipment installation, commissioning, and acceptance. Basic construction is the cornerstone of ensuring the stability of the crane, and precise construction is required according to design requirements to ensure a flat and solid foundation. During the equipment installation phase, it is necessary to strictly follow the installation plan and schedule to ensure the correct installation position and reliable fixation of the equipment. The debugging phase is the process of verifying the various functions of the crane, including testing of the electrical system, hydraulic system, control system, and other aspects to ensure the normal operation of the equipment. Acceptance is a comprehensive inspection of installation quality, which requires operation in accordance with relevant standards and specifications to ensure that the equipment meets the requirements for use.

Debugging and Testing

Debugging and testing are important steps to ensure the normal operation of the crane. During the debugging process, technicians need to conduct comprehensive and detailed testing and verification of various functions of the crane. This includes but is not limited to functional testing of key components such as electrical systems, hydraulic systems, and control systems to ensure they meet design requirements and usage needs. A comprehensive assessment of the safety of the crane is also required. This involves testing and validation of structural stability, load-bearing capacity, protective performance, and other aspects to ensure that the crane can maintain good safety performance during long-term use and avoid potential safety hazards.

Acceptance criteria and procedures

Acceptance standards and procedures are important links in ensuring the quality of cranes. During the acceptance process, a comprehensive inspection and evaluation of the crane must be conducted in accordance with relevant standards and specifications. Including but not limited to appearance quality, structural integrity, functional performance, safety performance, and other aspects. Inspect the appearance quality to confirm that there are no damages or deformations on the surface of the equipment; Conduct structural integrity testing to confirm that the structural components of the equipment are intact and securely connected; Test the functional performance to confirm that all functions of the device are operating normally; Evaluate the safety performance and confirm that there will be no safety hazards during the use of the equipment. It is also necessary to test and record the operation of the crane. By conducting actual operational testing, observe the operating status and performance of the equipment to confirm whether it meets the usage requirements. At the same time, establish a comprehensive acceptance record and reporting system, detailing the acceptance process and results, providing reference for subsequent use and maintenance.

Maintenance and upkeep

Daily maintenance and inspection

Daily maintenance and inspection are key links to ensure the long-term stable operation of the crane. Firstly, regularly clean the various components of the crane, removing dust, dirt, and debris to maintain a good working environment. Secondly, according to the requirements of the equipment, regularly lubricate the crane to reduce wear and extend its service life. In addition, it is necessary to regularly inspect and tighten the fasteners of the crane to prevent accidents caused by looseness. At the same time, it is necessary to inspect and record the operation of the equipment, promptly identify and solve problems.

Fault diagnosis and troubleshooting

When the crane malfunctions, it is necessary to promptly diagnose and troubleshoot the problem. Firstly, by checking the operation and fault symptoms of the equipment, analyze the causes and mechanisms of the faults. Secondly, based on the fault analysis results, develop corresponding maintenance plans and measures. During the maintenance process, it is necessary to supervise and inspect the maintenance process to ensure that the maintenance quality meets the requirements of relevant standards and specifications. Finally, inspect and record the repair results to ensure that the malfunction is completely resolved.

Suggestions for major repairs and renovations

As the usage time of the crane increases, its performance may gradually decline. Therefore, it is necessary to regularly carry out major repairs and renovations on the crane. The major overhaul mainly includes a comprehensive inspection and evaluation of the structure and function of the equipment, identifying and resolving existing problems. Renovation mainly involves upgrading and optimizing equipment based on actual needs and technological advancements. During the overhaul and renovation process, it is necessary to supervise and inspect the renovation process to ensure that the renovation quality meets the requirements of relevant standards and specifications. At the same time, it is necessary to inspect and record the results of the renovation to ensure that the expected goals are achieved.

Maintenance plan and records

To ensure the long-term stable operation of the crane, a detailed maintenance plan and records need to be developed. The maintenance plan should include elements such as maintenance cycle, maintenance content, and maintenance personnel. The maintenance cycle should be set according to the actual usage of the equipment and the manufacturer's recommendations. The maintenance content should cover all components and systems of the equipment, and the maintenance personnel should have professional knowledge and skills. At the same time, a maintenance record management system should be established to provide detailed records of the time, content, personnel, and other information of each maintenance. By managing maintenance plans and records, it is possible to ensure timely and effective execution of crane maintenance work. In addition, it can provide strong reference for the maintenance and management of equipment.

Structural design specification for 63/20t, span 25.5m, double girder overhead travelling crane

Code of practice for safety of magnetic lifting appliances

 As an indispensable equipment in modern industry, the safety of magnetic lifting device is directly related to the efficient operation of production operations and personnel safety. These devices by virtue of the powerful magnetic force, can easily lift all kinds of heavy objects, greatly enhancing the work efficiency. However, if the magnetic lifting device is not operated properly or the design is defective, it may also cause serious safety accidents. Therefore, in-depth discussion of the safety specifications of magnetic lifting device, clear from the design and manufacture to the use of maintenance of all aspects of the safety requirements for the protection of production safety, accident prevention is of great significance. In this paper, we will comprehensively analyze the safety technical points of magnetic lifting device, in order to provide scientific guidance for relevant practitioners.

Overview of Magnetic Lifting Device

Definition and classification of magnetic lifting device

Magnetic lifting device is a kind of advanced mechanical equipment, using the principle of magnetic force to realize the lifting and moving of heavy objects. It realizes the lifting of heavy objects by generating a strong magnetic field and producing an adsorption force on magnetic materials such as steel. This device is widely used in industrial production and logistics transportation, which greatly improves work efficiency and safety. According to the different ways of generating magnetic force, magnetic lifting device is mainly divided into two categories: electromagnetic lifting device and permanent magnet lifting device.

Electromagnetic lifting device: the use of energized coils to generate a magnetic field, through the control of the current to control the generation and disappearance of the magnetic field. This lifting device is suitable for frequent lifting and lowering occasions, such as steel, shipbuilding, machinery manufacturing and other fields. When energized, the electromagnet generates a strong magnetic field that attracts ferromagnetic materials, such as steel. When the power is cut off, the magnetic field disappears and the ferromagnetic material is released. Since the strength of the magnetic field of the electromagnet can be adjusted by the size of the current, this lifting device has good flexibility. However, electromagnetic lifting device requires external power supply, so it cannot be used in the absence of power supply.

Permanent magnet lifting device: the use of permanent magnets to generate a constant magnetic field, to achieve a stable adsorption of ferromagnetic substances. This lifting device is suitable for long time fixed lifting occasions, such as heavy equipment, logistics and warehousing and other fields. The magnetic field strength generated by the permanent magnet is fixed, so this lifting device can realize the stable adsorption and lifting of ferromagnetic substances. Since the magnetic field strength of the permanent magnet is not affected by the power supply, this lifting device can be used in the absence of power supply. However, the magnetic field strength and stability of the permanent magnet lifting device are limited by the performance of the permanent magnet, and may not be flexible enough compared to the electromagnetic lifting device.

Working principle of magnetic lifting device

The working principle of the magnetic lifting device is based on the interaction between electromagnetic induction and magnetic force. When the electromagnetic lifting device is powered on, the current passes through the coil to generate a magnetic field, which attracts ferromagnetic substances; When the power is cut off, the magnetic field disappears and ferromagnetic substances are released. The permanent magnet lifting device utilizes the high-performance magnetic field of the permanent magnet to achieve stable adsorption of ferromagnetic substances. Whether it is an electromagnetic or permanent magnet lifting device, its working efficiency and safety depend on the strength and stability of the magnetic field.

The working principle of the electromagnetic lifting device is based on the law of electromagnetic induction and Ampere's loop law. When current passes through a coil, according to the law of electromagnetic induction, the coil generates a magnetic field that attracts ferromagnetic material. Meanwhile, according to Ampere's Loop Law, the magnetic field strength inside ferromagnetic materials is directly proportional to the magnetic field strength applied externally. Therefore, when the electromagnet generates a sufficient magnetic field, it can attract and fix ferromagnetic materials. Once the current is disconnected, according to the law of electromagnetic induction, the magnetic field in the coil will quickly disappear, and ferromagnetic substances will also be released.

The permanent magnet lifting device utilizes the constant magnetic field of the permanent magnet to achieve the adsorption and lifting of ferromagnetic substances. The magnetic field strength and direction of permanent magnets are fixed, thus enabling stable adsorption of ferromagnetic substances. Due to the fact that the magnetic field strength of permanent magnets is not affected by external power sources, they can be used in situations without a power source. However, the magnetic field strength and stability of permanent magnets are limited by their own performance, and may not be flexible enough compared to electromagnetic lifting devices. In practical applications, it is necessary to choose a suitable lifting device based on the specific usage environment and requirements.

Application scope of magnetic lifting device

Magnetic lifting device is a mechanical equipment that uses the principle of magnetic force to lift and move heavy objects, widely used in fields such as steel, shipbuilding, machinery manufacturing, logistics and warehousing. It has the advantages of high efficiency, safety, and flexibility, especially when dealing with heavy, large, or irregularly shaped steel products, demonstrating unique advantages. In addition, in high-tech fields such as nuclear power plants and aerospace, magnetic lifting devices also play an important role in transporting and installing precision equipment.

In the steel industry, magnetic lifting devices are widely used in the transportation of molten steel, hoisting of steel ingots, and recycling of scrap steel. By using a magnetic lifting device, precise control of molten steel can be achieved, improving transport efficiency; At the same time, it can reduce the labor intensity of staff and improve job safety. In the shipbuilding industry, magnetic lifting devices are used for lifting and flipping of ship sections, sections, and large components. Due to the complex structure and heavy weight of the ship, using traditional lifting methods poses significant difficulties and risks. By using magnetic lifting devices, precise control and safe lifting of ship components can be achieved. In addition, in the field of mechanical manufacturing, magnetic lifting devices are widely used in the lifting and installation of heavy equipment and precision components. It can achieve precise control and safe lifting of heavy objects; At the same time, it can also improve production efficiency and reduce labor intensity for workers. In the field of logistics and warehousing, magnetic lifting devices are used for cargo handling, loading and unloading, and storage. Can achieve fast and accurate handling of goods; At the same time, it can also improve warehousing efficiency and management level. In addition, in the field of nuclear power plants, due to the precision and heavy weight of the equipment, traditional lifting methods are prone to damage or radiation pollution to the equipment. By using magnetic lifting devices, precise control and safe lifting of equipment can be achieved; At the same time, it can also reduce the risk of radiation damage to personnel.

Design and Manufacturing Safety Requirements

Design and manufacturing safety standards

The design and manufacturing process of magnetic lifting device strictly follow the relevant national and industry safety norms and standards, such as the “Safety Regulations for Hoisting Machinery” (GB 6067.1-2010) on the specific safety and technical conditions of electromagnetic lifting machinery. These standards not only specify the overall structural layout of the magnetic lifting device, component materials and dimensions, but also put forward clear requirements on the performance indicators of the equipment, the setup and effectiveness of safety guards, etc., in order to ensure that the magnetic lifting device from the very beginning of the design of the high efficiency, reliability and intrinsic safety features.

Setting and Calculation of Safety Factor

In the design phase of the magnetic lifting device, the setting of the safety factor is a key technical decision. The safety factor is the ratio between the maximum load that the device can withstand under normal operating conditions and the rated load, which directly reflects the ability of the device to resist overload and accidental conditions. In order to ensure that the magnetic lifting device can still maintain stable and safe operation in the face of unexpected conditions, the designer must scientifically and reasonably determine and rigorously calculate the adequate safety coefficient according to the actual working environment of the equipment, material properties and the expected service life of the equipment and other factors. This will not only effectively prevent equipment damage or even accidents caused by overloading or abnormal working conditions, but also provide sufficient time for the operator to react and take measures, thus guaranteeing the safety and reliability of production operations.

Control gear settings and warning signals

The operation control panel of the magnetic lifting device should be clearly designed, reasonably laid out, with a clear control gear, so that the operator can easily choose and switch between lifting and moving operations according to the actual needs. In order to further enhance the safety and standardization of the operation process, the magnetic lifting device should also be equipped with the necessary warning signal system, such as sound and light alarms and other equipment. When the device starts, stops or encounters abnormal conditions, warning signals can ring in time to remind the operator to pay attention and take appropriate measures to effectively avoid potential safety risks.

Material selection and manufacturing process

In terms of material selection, the components of the magnetic lifting device should be selected according to the strength requirements, wear resistance and corrosion resistance and other criteria to select the appropriate material. For example, the load-bearing structural components should be selected from high-strength steel to ensure adequate load-bearing capacity; key components related to magnetism, such as electromagnets, permanent magnets, etc., should be selected from high remanent magnetic induction strength, high coercivity and good temperature stability of the high-performance permanent magnet materials, and after strict quality inspection to ensure its reliable performance.

In terms of manufacturing process, the entire magnetic lifting device manufacturing process should strictly comply with the relevant manufacturing process specifications to ensure that the precision and reliability of the equipment to meet the design requirements. Especially in the production process, effective quality control measures should be taken to prevent equipment defects or hidden dangers due to improper manufacturing process. In addition, for the machining and assembly of key components, it is more necessary to strive for excellence and achieve precise measurement and fine operation to ensure the excellent quality of the final product.

Safety regulations for use and operation

Pre-use Inspection and Confirmation

Before using the magnetic lifting device, the operator should carry out a comprehensive and detailed inspection of the equipment, including but not limited to the electrical system, hydraulic system and control system and other key components of the function test. For the electrical system, should confirm that the power supply is stable and reliable, all kinds of switches, buttons and indicators and other components are working properly, no damage, ablation and other abnormalities; hydraulic system, need to check whether the oil pipeline is intact without leakage, hydraulic pumps, valves and other components of good performance, normal pressure; control system should be to ensure that the sensors, controllers and drives sensitive and effective, the program logic is correct and error-free.

In addition, the operator also needs to understand and confirm the detailed working range of the equipment, load limit and other important parameters, clear equipment in what working conditions under the most appropriate operation, overloading is strictly prohibited to ensure that the equipment is always in the specified conditions. At the same time, in accordance with the equipment manual or relevant specifications, the equipment should be regularly maintained and necessary preventive maintenance to ensure that it is in good working condition.

Safety precautions during operation

In the process of operating the magnetic lifting device, the operator must strictly comply with the established operating procedures, maintain a high degree of concentration throughout the entire process, and shall not engage in other activities unrelated to the operation. Especially in the lifting and lowering of heavy objects in this critical link, the operator is required to do a smooth operation, to avoid sudden acceleration or deceleration of the object caused by swinging too large, or even fall off and other accidents.

In the process of lifting, the operator should reasonably plan the route to ensure that the heavy object will not collide with other equipment or structures when moving. At the same time, pay close attention to the operating status of the equipment components, such as found abnormal sound, vibration or temperature is too high, should immediately stop the machine to check, troubleshooting before continuing operations. In addition, for special types of goods or operations in special environments, it is also necessary to take appropriate safety measures in accordance with relevant regulations, such as bundling and fixing, the use of special tools and so on.

Prohibited Operating Behaviors

A series of high-risk operating behaviors are strictly prohibited during the use of magnetic lifting devices. First and foremost, the load limit of the equipment must not be exceeded, the weight of the heavy object to accurately assess the weight, to avoid overloading the equipment caused by damage, deformation or even lead to safety accidents. At the same time, unlicensed operation is also expressly prohibited behavior, all operators must be professionally trained and obtain the appropriate qualification certificate before they can operate.

Unauthorized or non-professionals are strictly prohibited from modifying the structure of the equipment, adjusting key parameters or destroying the original safety protection functions of the equipment. Such behavior is likely to lead to equipment performance degradation, loss of stability, increase the risk of failure, and even lead to serious personal injury or property damage accidents.

Inspection and Maintenance Safety Requirements

Periodic Inspection and Maintenance Program

As a heavy equipment, the safety and reliability of the magnetic lifting device is crucial for production operations. Therefore, comprehensive and detailed inspection and maintenance work must be carried out regularly. For the electrical system, cables, connectors, switches and other components should be checked regularly to see if they are intact, and whether the lines are aging or exposed, in order to ensure a stable and reliable supply of electricity, and to avoid accidents caused by electrical failures. For the hydraulic system, it is necessary to check whether the key components such as oil pipelines, hydraulic pumps, valves, etc. are leaking, blocked or damaged to ensure that the hydraulic system works at a stable pressure and operates flexibly.

In terms of the control system, it is necessary to verify whether the control components, sensors, actuators and other equipment are working properly, and whether the data acquisition and processing functions are accurate, in order to ensure that the magnetic lifting device operates accurately according to the preset program. For the magnet part, in addition to checking its appearance with or without damage, deformation, but also need to test its magnetic can meet the use of requirements, such as whether the magnetic induction strength is up to standard, whether the magnetic field distribution is uniform and so on. At the same time, the appearance, function, performance and other aspects of the equipment should also be comprehensively inspected and maintained to ensure that the overall operating condition of the equipment is good.

Maintenance methods and steps

Magnetic lifting device maintenance is a systematic and detailed work, the specific methods and steps are as follows: First of all, to ensure that the surface of the equipment is clean and free of grease and dust adhesion, can be used to special cleaning agents or high-pressure air pumps to clean up the surface dirt, in order to maintain good visibility and heat dissipation performance; Secondly, regular inspection of the equipment fastening of various components, including but not limited to bolts, nuts, washers and other connectors, to ensure that no loose Finally, for wearing parts such as solenoid coil, hydraulic oil, etc., they should be replaced in time according to the degree of wear and tear to prevent equipment failure or safety accidents due to aging and failure of parts.

Safety Requirements for Repair and Replacement of Parts

When repairing and replacing parts of the magnetic lifting device, the primary safety requirement is to ensure that the equipment is in a de-energized state, and take appropriate safety measures. For example, hanging conspicuous warning signs at the maintenance site to prevent unrelated personnel from approaching the operation area; using insulated tools for operation to avoid accidents caused by electric shock. In addition, maintenance personnel should have solid professional knowledge and rich operational skills. In the maintenance process should strictly abide by the relevant operating procedures and safety norms; fully understand the structure and working principle of the equipment; the correct use of tools and equipment; to avoid new safety hazards due to improper operation.

Security Monitoring and Emergency Response

Configuration and application of safety monitoring system

As an efficient and safe heavy equipment, the operation status of the magnetic lifting device is directly related to the safety and efficiency of production operations. In order to ensure that the magnetic lifting device is always in the best working condition, it should be equipped with a complete set of safety monitoring system. The system realizes real-time monitoring of the magnetic lifting device workload by integrating advanced equipment such as weight sensors, displacement sensors and temperature sensors.

Weight sensors accurately measure the weight of the lifted object to ensure that it will not be overloaded during the lifting process; displacement sensors monitor the position and movement trajectory of the spreader in real time, effectively preventing collision or tipping accidents due to misuse; temperature sensors detect the temperature rise of the key parts of the equipment in real time, to prevent damage to the equipment due to high temperatures or fire accidents. These key data are transmitted to the central control system in real time through wireless transmission technology, so that the operator can grasp the operating status of the equipment at any time, and discover and deal with potential safety hazards in a timely manner.

The safety monitoring system also has an intelligent warning function. Once the equipment operating parameters exceed the preset safety thresholds, the system will immediately trigger the alarm device, and through cell phone text messages, emails and other means of timely notification of the management personnel, to ensure that they can react in the first time to take appropriate safety measures. This greatly improves the efficiency and accuracy of safety management and effectively reduces the risk of safety accidents caused by equipment failure or operational errors.

Emergency Disposal Process and Measures

In the event of a malfunction or accident of a magnetic lifting device, it is crucial that the emergency handling process is activated quickly. Operators should first receive rigorous emergency training, familiar with and master the emergency procedures. Once an abnormality or malfunction of the magnetic lifting device is detected, the first action is to stop the operation of the equipment immediately and quickly cut off the power supply to avoid causing further damage or injury. This step is critical to effectively prevent a chain reaction triggered by the loss of control of the equipment.

Depending on the specific type and extent of the accident, operators need to quickly take appropriate emergency measures. For example, if the accident involves chemical leakage or high-temperature burns and other dangerous situations, the site should be immediately evacuated to a safe area, and set up isolation zones to prevent unrelated personnel from approaching the accident site; if it is a small-scale accident triggered by equipment damage or operational errors, a localized emergency response plan should be activated immediately, such as starting standby equipment, adjusting process parameters, etc.; for any type of accidents, an emergency rescue plan should be activated in a timely manner and the relevant emergency rescue should be notified. For any type of accident, the emergency rescue plan should be activated in time, and the relevant emergency rescue team should be notified to rush to the scene for disposal.

In the process of emergency disposal, communication should be kept free, timely communication and coordination of all forces. After the accident occurs, the accident reporting procedure should be started immediately, and the accident situation should be reported to the higher management and relevant emergency command departments in time. At the same time, it is necessary to protect the accident scene and cooperate with relevant departments to investigate and analyze the accident. Through scientific and rigorous accident investigation, the real cause of the accident can be identified, providing valuable experience and lessons for future safety production.

Accident records and analysis

For accidents occurring in magnetic lifting devices, information such as the time, location, cause and handling process of the accident should be recorded in detail. This information can be recorded in written or electronic form and properly stored. The degree of detail of the accident record directly affects the analysis of the accident and the effect of improvement. Through in-depth analysis of accidents, lessons can be summarized and targeted improvement measures can be proposed to avoid the recurrence of similar accidents.

When analyzing the causes of accidents, they should be considered from multiple perspectives, including equipment failures, human factors, environmental factors and so on. Through in-depth analysis of these factors, the root cause of the accident can be identified, providing a basis for the proposal of improvement measures. When proposing improvement measures, factors such as safety, reliability, feasibility and sustainability should be fully considered. Improvement measures should be targeted and operable, and be able to effectively prevent the recurrence of similar accidents. Improvement measures should also be regularly evaluated and reviewed to ensure their effectiveness and applicability.

Additional Safety Technical Measures

Application and limitations of the magnetizing function

The magnetization function in magnetic lifting device realizes high flexibility and wide adaptability of lifting operation through fine regulation of magnetic field strength and range of action. In practical application, according to the weight, volume, material of the lifted object and the different requirements of the lifting environment, the magnetizing function can accurately adjust the strength of the magnetic field to ensure that when lifting and moving heavy objects will not cause the object to slip off, but also minimize the damage to the lifted object. At the same time, the intelligent design of the magnetizing function allows the operator to remotely control or automatically adjust the magnetic field parameters according to the actual working conditions, which greatly improves operational efficiency and safety. However, despite the significant advantages of the magnetizing function, safety norms and operating procedures must be strictly observed in the process of using it. Too high or too low a magnetic field strength may lead to uncontrolled lifting of the object or can not be properly adsorbed, which may lead to serious safety accidents. Therefore, for the use of magnetic function, not only need the operator with professional skills and knowledge, but also have a rigorous work attitude and good emergency response ability.

Combined crane safety requirements

In the face of large, complex lifting tasks, often need more than one magnetic lifting device to work together to achieve efficient and safe combination of lifting. At this time, the first task is to ensure that all the magnetic lifting devices involved in the operation of the performance parameters match each other, including but not limited to magnetic suction force, load carrying capacity, working range and other aspects of consistency and coordination. This means that each unit must be able to operate stably in a given operating environment and be able to provide adequate power support when required. In order to ensure the stability and safety of the entire combined crane system, the signal transmission and control system between the equipment must be strictly calibrated and verified, to achieve accurate remote control and real-time monitoring, to prevent inconsistent action between the equipment due to signal delays or misoperation, which may cause safety accidents. In the process of combined lifting, it is crucial to reasonably design and implement an effective load distribution program. This means that according to the performance characteristics of each piece of equipment, stress conditions and operating environment and other factors, scientific and reasonable distribution of the total load weight, to avoid single point overload or uneven load distribution.

Safety measures under special working conditions

For the operation of magnetic lifting device under special working conditions, such as high temperature environment may lead to equipment internal component performance degradation or failure; strong magnetic field environment may cause interference or damage to electronic components; corrosive environment may erode the surface of the equipment and the internal structure, reduce the durability and sealing performance of the equipment. In this case, a series of additional precautions must be taken to ensure the safe operation of the equipment. For example, the use of high-temperature-resistant materials for the manufacture of key components; special design of the equipment or the addition of protective cover, heat dissipation system and other auxiliary facilities; regular inspection and maintenance of the equipment to ensure that it is still able to maintain stable and reliable operation under extreme conditions; according to the specific characteristics of the working conditions of the development of a detailed safety operating procedures and contingency plans.

Code of practice for safety of magnetic lifting appliances