Electric single beam technology solution
1. Technical parameters of LD3t-22.5m A5 electric single beam bridge crane
Institution Name
Project lifting mechanism name
Project operating organization
Gourd running large vehicle
Lifting capacity (t) 3 gauge (mm)/22500
Lifting height (m) 15 Running speed m/min 2-20 3-30
Work Level M5 Work Level M5 M5
Lifting speed m/min 0.8/5 wheelbase (mm)//
Electric hoist model NWH3t-15m steel rail model steel plate 43kg/m
Power supply three-phase AC 380V 50HZ wheel diameter (mm)/Φ 200
Maximum wheel pressure 20KN three in one reducer model/FA37-DT71D4/BMG
Crane weight 6.8 t power/2 × 0.37KW
Control form ground operation+wireless remote control limit switch LX10-11 LX10-11

2 Technical parameters of LD3t-19.5m A5 electric single beam bridge crane
Institution Name
Project lifting mechanism name
Project operating organization
Gourd running large vehicle
Lifting capacity (t) 3 gauge (mm)/22500
Lifting height (m) 15 Running speed m/min 2-20 3-30
Work Level M5 Work Level M5 M5
Lifting speed m/min 0.8/5 wheelbase (mm)//
Electric hoist model NWH3t-15m steel rail model steel plate 43kg/m
Power supply three-phase AC 380V 50HZ wheel diameter (mm)/Φ 200
Maximum wheel pressure 20KN three in one reducer model/FA37-DT71D4/BMG
Crane weight 5.5t power/2 × 0.37KW
Control form ground operation+wireless remote control limit switch LX10-11 LX10-11

（1） Manufacturing process and structural description of electric single beam crane
As shown in the schematic diagram, this crane adopts a European electric single beam bridge crane structure design.
Characteristics of European style single beam bridge crane:
1 Compact design
The advanced design concept enables the crane to have a lightweight structure and excellent performance, while minimizing the operating limit distance of the hook to the greatest extent possible, effectively improving space utilization, and also allowing customers to reduce factory investment costs. Adopting the European double beam bridge crane will bring you a richer return on investment.
2. Fast and balanced loading
The standard configuration of the crane is that both the small and large vehicles are variable frequency, which ensures smooth operation, fast positioning, and effectively solves the swinging of the load. It has the characteristics of braking balance, precise positioning, reliable performance, safety and efficiency.
3. Safer and more reliable, maintenance free
The perfect braking system greatly improves safety and reliability. The high-performance brake adopts dust-proof design, can be automatically adjusted, and has a safe service life of over 1 million times. The transmission gears are processed accurately, and the tooth surfaces are hardened and ground to ensure reliable long-term trouble free operation of the vehicle.
Fully embodies the advantages of European style cranes:
1. High lifting weight, low clearance, low wheel pressure, and smooth operation.
2. Quick positioning, ergonomic design, and comfortable operation.
3. Long service life and low maintenance
4. Use safety and reliability to improve production efficiency and create greater profits
5. Low driving force, energy-saving.
Introduction to the structure of European single beam bridge crane:
Main beam: Adopting a box shaped beam structure, each main beam is welded as a whole without any sections in the middle. The material of the main load-bearing components is not less than Q235-B. This structure has a simple structure, determined stress, good overall stability, fatigue resistance, and a small number of transverse reinforcements inside the beam. The processing technology is simple and can effectively shorten the production cycle. The overall cross-section of the main beam is optimized, fully utilizing the potential of the material and being lightweight.
The main structural material is Q235-B steel plate, and all butt welds of the steel plate are subjected to non-destructive testing according to the regulations of "General Bridge Crane" to ensure the quality of the welds. During radiographic testing, the level shall not be lower than Grade II specified in GB3323, and ultrasonic testing shall comply with the provisions of JB/T10559-2006.
Electrical part: This product is equipped with imported motors such as ABM or ABB for operation. Both the electric hoist and the entire machine are equipped with safety devices, such as lifting limit switches, large vehicle end limit switches, etc.
The operation of the crane and trolley adopts variable frequency speed regulation, and the electrical system consists of a "PLC+AC variable frequency drive" system. PLC control is added to the lifting system to make it more stable. At the same time, it also raised the level of the equipment. This system consists of an operating console and two cabinets. Two of the cabinets are controlled by a PLC and two frequency converters. The programmable controller controls the frequency converter to achieve motor soft start, multi speed operation, and braking functions. The use of a programmable controller not only simplifies the control circuit, but also achieves precise adjustment of logic control and time parameters through PLC, while also increasing the reliability of the system and reducing the failure rate. The operator can input control commands to the PLC through the control panel, and then use the PLC to control the frequency converter according to the control conditions. The PLC also adds limit devices and braking devices to the frequency converter to achieve accurate positioning and control of the brakes, preventing the occurrence of hook slipping. The use of frequency conversion control in the crane significantly improves the overall performance of the machine. Smooth and stable lifting and walking, with accurate positioning of the lifted object. Up and down as needed. The front, back, left, and right operations can all be infinitely variable, adapting to various practical situations. In addition, the inverter has complete protection functions, such as overcurrent, overload, overvoltage, etc., which can alarm and stop in a timely manner, reducing crane failures and improving safety performance. At the same time, the frequency converter has a current limiting effect, which can reduce the impact on the power grid during startup and facilitate the normal operation of other equipment in the workshop.
There are the following advantages:
Wide speed regulation range, capable of achieving operations with precise control and positioning requirements;
The functions of soft start and soft stop reduce mechanical transmission impact, significantly improve the load-bearing performance of steel structures, and extend the service life of cranes;
High integration components and high reliability low-voltage electrical appliances effectively solve the complex wiring problems of the original electrical system, not only reducing the probability of system failures, but also easy to maintain;
At low speeds, the electric motor can output 200% torque, and even if the brake is loose or malfunctioning, there will be no heavy object sliding down, ensuring the safety and reliability of the system;
It has fast dynamic response, no hook slipping, and truly achieves the "zero speed crossing" function;
The frequency converter used in the system has an automatic energy-saving operation mode, which can greatly improve the power factor and overall working efficiency of the system, with significant energy-saving effects and an average energy-saving rate of over 20%;
After adopting the variable frequency speed regulation system, it can completely eliminate operators' illegal operations.
Electric hoist
Adopting European style low static electric hoist, it has the characteristics of compact structure, lightweight, safety and reliability, large universal program of components, strong interchangeability, high lifting capacity, and easy maintenance. It is currently a widely used and popular lightweight lifting equipment.
The gourd is of the small car type, which has operational functions and can be installed on tracks for use. MD1 type is a dual speed lifting system.
1. Main purpose:
The small car type hoist can be installed on various types of cranes or suspended on I-beams to lift heavy objects back and forth in a straight or curved line.
This product is widely used in industrial and mining enterprises, railways, docks, warehouses, material yards and other places. It is an essential machinery for improving working conditions and increasing labor efficiency in current production operations.
2. Scope of adaptation and working conditions
This product is suitable for working in environments with -25 ℃~+40 ℃, humidity ≤ 85%, altitude below 100m, no fire, explosion hazards, corrosive media, and no dust pollution. It is prohibited to lift molten metals, toxic, flammable, and explosive materials. The applicable power supply is AC three-phase, 50Hz, 380V; The working type of this product is intermediate, and for every level increase in the working level of the mechanism during use, its rated lifting mass must be reduced by 20% accordingly.
3. Transmission structure and working principle
The European low static electric hoist is mainly composed of three parts: the lifting mechanism; Second, the operating mechanism (not available for fixed types); Three are electrical devices.
3.1. Lifting mechanism
The lifting mechanism is driven by the lifting motor through the coupling and the hollow shaft of the reducer to rotate the drum, so that the steel wire rope wound on the drum drives the hook device to rise or fall.
When the lifting height H=6m, use a claw type coupling to connect the motor shaft and the input shaft of the reducer. When H ≥ 9m, add an intermediate shaft and a rigid coupling. When H ≥ 18m, equip a support frame to strengthen the rigidity of the intermediate shaft and maintain rotational balance.
3.1.1. Lifting motor
The lifting motor adopts a conical rotor motor with a larger starting force to adapt to frequent direct starting during intermittent operation of the product. This electric hoist is equipped with a dual speed motor.
3.1.2. Reducer
The 0.25t gourd reducer is a spur gear planetary transmission mechanism, while all other reducers use helical gear three-stage reduction. Gears and shafts are made of alloy structural steel or high-quality carbon steel, and undergo appropriate heat treatment to ensure their reliability and lifespan. The box body and cover are made of cast iron, with good vibration reduction and reliable sealing.
3.1.3. Drum device
The drum is made of cast iron or seamless steel pipe and uses splines to transmit power; The outer shell of the drum is welded from steel plates.
The drum device is the central part of the hoist, which is connected to the running mechanism through a balance beam, and connected to the lifting reducer motor at both ends. The lower part works in conjunction with the hook device through a steel wire rope. A limiter guide rod device is installed on the front upper part of the outer cover.
3.1.4. Hook device
The hook is forged from specialized steel and connected to the outer shell through a thrust ball bearing via the hook crossbeam, allowing the hook to operate freely. The hook device for 5t and below is a single sliding wheel, while for 10t and above it is a double sliding wheel. The hook material is DG20 # steel.
3.2. Operating mechanism
The electric car, running motor, running reducer, and driven car together form the running mechanism, which suspends the main engine for reciprocating movement. Its operating speed is generally 20m/min. When the lifting height is ≥ 12m from 1 to 5t, an additional driven trolley is added.
3.3. Electrical devices
The electrical device of the European low static electric hoist consists of an electrical control box (0.25t without), button switches, limiters, and connecting wires.
The operating voltage of the button switch is generally 380V or 36V. For non special orders, the voltage distribution should be controlled by 380V. According to the direction symbol on the button switch, press the button correctly and control the action of the hoist by closing and disconnecting the relay inside the control box.
The circuit diagram in this manual should be used in conjunction with the accompanying motor and electrical circuit diagrams.
4. Installation and Debugging
4.1. Installation
Inspection and preparation before installation
After the electric hoist is transported to the installation site, it shall be inspected according to the packing list and checked for any damage or loss of parts during transportation.
Carefully read the user manual and other accompanying documents to understand the structure of this product.
The operating trolley, current inlet, and hook device (excluding 10t) are generally disassembled and packed with the main engine, and must be reassembled during installation;
Clean the oil stains or anti displacement paint on the tread of the electric car;
Add oil to the lifting and operating reducer according to Table 8 and Table 11 of this manual, and seal the oil filling hole to prevent leakage.
Understand the installation site and prepare for the installation of facilities.
install
The track structure for the mobile use of the power supply hoist shall be selected and designed by the user in accordance with the GB706-88 standard. Adjust the gasket during installation to ensure a gap of 3-5mm between the wheel flange and the rail flange.
The installation of fixed hoists should ensure correct installation orientation and safe and reliable support frame.
Regarding the situation with the gourd, refer to the relevant circuit diagram and install the electrical appliances.
Installation precautions
To ensure that the electric hoist does not derail or collide with the body at both ends, polyurethane buffers should be installed at both ends of the track; A grounding wire should be installed on the track or its connected structure, which can be a bare copper wire with a diameter of Ø 4-5mm or a metal wire with a cross-section of not less than 25mm2.
The ground resistance of all power circuits and circuits of electrical devices shall not be less than 1000 ohms per volt of operating voltage.
4.2. Inspection and Debugging
Check whether each connecting part is firmly connected, whether the assembly meets the requirements, whether the power supply meets the regulations, whether the circuit is correct, whether the brake and limit device are sensitive and reliable, whether the rope guide is smoothly arranged, whether the running car deviates, and whether the wheel tread and guide rail are in good contact. Once a problem is discovered, it should be corrected promptly. Common troubleshooting methods are shown in Table 3
debugging
Adjust the gap between the car rim and the track flange to ensure it is between 3-5mm.
Adjustment of motor spindle displacement
When the axial displacement of the main shaft of a conical rotor motor is generally 1.5mm, the braking effect is optimal. If the electric hoist slides too much at rated load, it needs to be adjusted. The adjustment method is as follows:
Adjustment of hoist motors of 5t and below: Remove the tail cover, unscrew the four screws that fix the adjustment nut, use a wrench to turn the adjustment nut clockwise to the limit position, then turn it counterclockwise once, and then install the sturdy screw.
The adjustment method for the 10t and 16t hoist motors is the same as recommended above, except that the nut rotation direction is opposite, that is, clockwise rotation increases the amount of play, and counterclockwise rotation decreases the amount of play.
Adjustment of the flame arrester
The adjustment of the flame arrester is achieved by adjusting the two collision blocks on the limit rod. The adjustment method is to loosen the screws on the collision block, place the collision block on both sides of the rope guide card, and the card can freely push the stopper to move. Start the motor to lift, and the upper limit collision block is pushed by the card plate to move. When the upper edge of the hook pulley shell is 150mm-50mm away from the lower edge of the drum shell, stop rising. Press the descent button, and when the rope guide moves back about 10mm, stop the machine. Move the upper limit collision block close to the card plate and tighten the screw.
The adjustment of the lower limit position is the same as above, but in the opposite direction. However, it must be ensured that when the hook is handling the lowest position, there are at least 3 turns of steel wire rope left on the drum.
After adjustment, it can be lifted several times without load to verify whether the upper and lower limits meet the requirements.
5. Test run and acceptance
5.1. No load test
Press the corresponding button with your hand and check if the actions of each mechanism are consistent with the symbols marked on the button device. After confirming that they are correct, perform two consecutive cycles each.
Lift the hook to the limit position and check if the limiter is reliable.
Press the button and visually inspect the axial air displacement of the motor shaft, which should be within the range of 1-2mm.
After the no-load test, if there are no abnormalities, the load test can be carried out. The load test is divided into static load test and dynamic load test.
5.2. Static load test
Under rated voltage, lift at 1.25 times the rated load and lift 100mm off the ground. After 10 minutes of rest, unload and check for any abnormal phenomena.
5.3. Dynamic load test
Under rated voltage, conduct a suspended load test at 1.1 times the rated load for a period of 40 seconds, with a rise of 6 seconds, a stop of 4 seconds, a drop of 6 seconds, and a stop of 14 seconds. Repeat this process for 15 cycles, and visually inspect each part for any abnormalities. If there are no abnormalities, the test is qualified.
The brake motor should be adjusted to be able to suspend the heavy object for braking. When the rated load is lowered for braking, the sliding amount S ≤ V liters/100mm
（2） Design, manufacturing, installation standards and specifications for equipment
1. GB/T3811-2008 "Code for Design of Cranes"
2. GB/T7592-1987 "Boundary Dimensions for General Purpose Bridge Cranes"
3. European standards
Fourth edition, October 1, 1987, reference number F E.M.1.001
5. Welding standards: DIN18800，BLATT7
6. Crane design and structural standards: DIN15018，BLATT2
7. Welding grade: DIN8563，BLATT3
8. Brakes and couplings: According to DIN15434, VDE0580, KONE or DIN15431 standards.
9. DIN15401 single hook
10. DIN15402 Double Hook
11. Electrical equipment: VDE0113, VDE0100, and CEE
12. Electric motor: IECRecommendations34-1， 34-5 and 72-1.
13. Select the motor according to FEM standards and fully comply with the international crane standard IKH6.30.1
14. Gearbox: Designed according to ISO/DIS6336/II-6336/V (DIN51150) standards.
GB6067-1985 "Safety Regulations for Cranes"
16. JB3229-83 "Three phase asynchronous motors with wound rotor for metallurgy and cranes"
17. GB/T6333-1986 "Electric Hydraulic Block Brakes"
18. ZBJ19011-1988 "Crane Reducer"
19. ZB19011-1988 "Crane Base Reducer"
20. GB/T14405-2011 "General Purpose Bridge Cranes"
GB/T5117-1995 "Carbon Steel Welding Rod"
22. GB/T699-1988 "Technical Conditions for High Quality Carbon Structural Steel"
23. GB/T700-1988 Carbon Structural Steel
24. GB/T5118-1995 "Low alloy steel welding rods"
25. GB/T5293 "Fluxes for submerged arc welding of carbon steel"
26. GB/T14957 "Steel Wire for Fusion Welding"
GB/T1348 "Ductile Iron Castings"
28. GB/T1591-1994 "Technical Conditions for Low Alloy Structural Steel"
29. GB/T985-1988 "Basic forms and dimensions of weld grooves for gas welding, manual arc welding, and gas shielded welding"
30. GB/T986-1988 "Basic forms and dimensions of submerged arc welding groove"
31. GB/T3323 "Radiography and Quality Grading of Fusion Welded Butt Joints in Steel"
32. JB/T90006-1999 "Cast pulleys for cranes"
33.GB6164 "Crane Buffer"
Technical Factors Affecting the Quality of Steel Melting Welded Joints (GB6416)
35.SZD014 General Technical Conditions for Clean Installation
36. GB6417 "Classification of Defects in Metal Melting Welds"
Requirements for Inspection of Materials and Welds of Main Structures of Cranes (GB979)
38.JB/J9008-1999 "Casting Rollers for Cranes"
39. GB8918-1988 "High Quality Steel Wire Rope"
GB/T1182-1184-1996 "Tolerances for Shape and Position"
41.GB/T4628 "Cylindrical Wheels for Bridge Cranes"
42. GB/T13384-1992 "General Technical Conditions for Packaging of Mechanical and Electrical Products"
43. GB/T191-1990 "Pictorial Marking for Packaging, Storage and Transportation"
44. GB/T8923-1988 "Surface corrosion grades and rust removal grades of coated steel materials"
45. GB/T14407-1993 "Technical Conditions for General Bridge Crane Cab"
46. GB10051 "Lifting Hooks"
47. GB/T10183-1988 "Manufacturing and track tolerances for bridge and gantry cranes"
48. GB/T5905-86 "Test specifications and procedures for lifting equipment"
49. GB/T3426 "Crane Rail"
50.SDZ014 "General Technical Conditions for Painting"
51. GB/T9286 "Planning tests for paint films of paints and varnishes"
GB/T1800-1804-1998 "Limits and Fits"
53. GBJ232 "Code for Construction and Acceptance of Electrical Equipment Installation Engineering"
54. GB/T12470 "Quality Assurance of Welding - Requirements and Defect Segmentation for Steel Fusion Welded Joints"
JB43154315 "Crane Electrical Control Equipment"
56. GB/T8110 "Steel Welding Wires for Carbon Dioxide Gas Shielded Welding"
GB/T14958 "Steel Welding Wires for Gas Shielded Welding"
58. GB/T1228-1231 "High strength large hexagon head bolts, nuts, washers and technical specifications for steel structures"
59. JGJ82 "Design, Construction, and Acceptance Engineering of High Strength Bolt Connections in Steel Structures"
GB50278 "Code for Construction and Acceptance of Crane Installation Regulations"
UL508C "Safety Specification Standard for Electrical Control Equipment"
62. GB/T7592-1987 "Boundary Dimensions for General Purpose Bridge Cranes"
63. GB/T6974-1986 "Terminology for Lifting Machinery"
64. GB/T15052-1994 "Dangerous parts and signs of lifting equipment"
65. GB/T11345-1989 "Manual Ultrasonic Testing Method and Classification of Testing Results for Steel Welds"
66. GB/T1031-1995 "Surface roughness parameters and their numerical values"
67. JB/T50103-1998 "Reliability Evaluation Test Specification for General Bridge Cranes"
68. JBJ31-96 "Code for Construction and Acceptance of Crane Equipment Installation Engineering"
69. GB50171-92 "Code for Construction and Acceptance of Panel, Cabinet and Secondary Circuit Wiring in Electrical Equipment Installation Engineering"
70. GB50254-96 "Code for Construction and Acceptance of Low Voltage Electrical Equipment Installation Engineering"
GB50256-96 "Code for Construction and Acceptance of Crane Electrical Equipment Installation Engineering"
72. JB/T10559-2006 "Ultrasonic Testing of Steel Welds for Non destructive Testing of Lifting Machinery"
（3） Quality Assurance
A complete quality assurance system (design, development, production, installation, and service) implementing ISO9001 full process control ensures product quality and gives users peace of mind when purchasing products.
The control and management of the physical quality of products in the production and manufacturing process is mainly achieved through "four reviews, eight controls, two types of identification, and internal quality audits".
Four reviewers
Namely, management review, contract review, design review, and non-conforming product review.
The management review is presided over by the top management, which evaluates the suitability and effectiveness of the quality system operation, the implementation of the quality policy, and the internal quality audit.
Contract review is a targeted implementation of different forms of review based on different types of ordered products before contract signing.
During the design review, different design stages of all product designs are evaluated, including conference style design reviews for new or key products, and the design output meets the design input requirements.
The review of non-conforming products is the main content of non-conforming product control. Different levels of review are conducted according to the severity of non-conforming products, including professional factory level review and company level review.
Eight controls
The eight controls are design control, document and data control, procurement control, customer provided product control, process control, inspection and testing, including testing equipment control, non-conforming product control, and quality record control.
Design Control
There is a strict design control management process within the technology center, from design planning to design confirmation. All design process activities are planned, controlled by measures, and have quality records.
Document and Data Control
The quality system documents and data control are managed by the technical center, and the entire process of distribution and use is manually controlled. The distribution has controlled identification, a record list, and approval for document changes.
The control of product drawings and technical documents is under the centralized management of the archives department. The entire process from design output to distribution, use to recycling in production is strictly controlled, and there is a special assessment system to ensure that the drawings and technical documents in use and archived are in a controlled state.
Procurement control
Seven supporting documents were issued to match the program files;
Strictly follow the qualified subcontractor list announced by the factory for procurement;
Implement subcontractor review and evaluation;
The main department is the Inspection Department, supplemented by the Design Department and the Material Supply Department. Three evaluation methods were used to assess the 25 supporting manufacturers of electrical components and equipment across the country: on-site audit of the source of goods, sample identification, and comprehensive evaluation;
Implement dynamic management of product quality for supporting manufacturers;
When problems are found with the quality of the supply, the control method of "please come in, go out" is adopted. The product quality is randomly inspected at the site of its subcontractors from time to time, and the manufacturer is convened for quality problem discussions and on-site product quality improvement meetings from time to time. If the quality is not qualified, a product quality improvement notice is issued and the manufacturer is ordered to improve it. If no corrective measures are taken, the qualification of the qualified subcontractor will be revoked.
Customer provided product control
Combined with procurement control, strictly implement incoming inspection or verification, set up dedicated warehouses and storage areas, and assign dedicated personnel to implement storage and protection control and management.
process control
A total of 20 general key processes have been identified and assigned to dedicated personnel, while one special process has been identified. Strictly follow the requirements for management, establish control over the implementation of key and special processes in the inspection department, and supervise and guide the execution status.
For the use and maintenance of equipment in key processes, monitoring and recording are carried out through the "Key Process Equipment Inspection Form" and "Key Equipment Inspection Form". For equipment in special processes, regular identification and recognition are also carried out under daily monitoring.
Organize multiple trainings on job skills and qualifications for personnel involved in critical and special processes, and insist on not allowing them to work without certification.
Monitor and control the appropriate process parameters and product characteristics specified in the technical documents such as process plan and process specifications during the operation of the process.
Control of Inspection and Testing
Strictly implement product quality inspection and testing. There are a total of 31 product quality inspection workers and 6 professional technical management personnel. A series of documented procedures have been issued for the incoming inspection, production process inspection, and final product inspection of purchased and outsourced parts. The principle of strictly implementing unqualified purchased and outsourced parts not being allowed to enter the factory, unqualified parts not being allowed to be transferred, unqualified product review, and unqualified products not being allowed to leave the factory is strictly enforced.
Control of non-conforming products
When non-conforming products are found, inspectors can immediately implement inspection and testing status identification, submit a non-conforming report, and the technical department in charge shall carry out non-conforming product review and disposal in accordance with regulations.
Control of Quality Records
The control of quality records is constantly supplemented and improved with the operation of the quality system. Our company has carried out rectification in accordance with the new national standards, and has completed a total of 64 specialized inspection records for bridge cranes and gantry cranes. We have implemented unified printing and distribution, ensuring effective identification, collection, storage, and disposal of product quality records, and facilitating archive management.
（4） Performance guarantee
1. During the static load test, the deflection of the main beam is strictly controlled within the standard range, and other mechanical properties are accepted according to the lifting machinery standards.
2. The surface of the hook has no obvious defects, honeycombs, or scattered cracks.
3. The gearbox and brake do not leak oil within the warranty period.
4. Ensure that the crane is correctly installed, operated and maintained, and operates well throughout its lifespan. During the warranty period, the supplier shall be responsible for any defects, malfunctions, and damages of the production line caused by design, process manufacturing, installation, commissioning, or material defects, as well as all supplier responsibilities.
5. The quality assurance period is 12 months for the equipment to be installed, debugged, and operate normally. During the installation, debugging, and warranty period, if any component damage is caused by equipment quality problems, the supplier shall send experienced technicians to the site for free repair within the time required by the demander, until replacement is made.
（5） Design, process equipment, manufacturing, and inspection methods
1. Design capability: The supplier has a technical center engaged in product technology research, development, and design. The technology center has more than 40 senior and intermediate engineers, with the chief engineer responsible for overall design quality and the chief engineer responsible for specific product design quality. It has strong technical strength, complete technical facilities, and is equipped with advanced computer-aided design (CAD) systems, which can proficiently carry out computer-aided design. The factory adopts the ISO9001 international standard from product to manufacturing process, ensuring that product design information is complete, correct, and unified, fully meeting the requirements of users.
2. Process collaboration conditions: The supplier has complete process collaboration conditions. Each factory is equipped with experienced process preparation technicians to ensure that the design quality of the products meets the design requirements stably. Process preparation work includes process analysis and review, preparation of process plans, process routes, process testing, process documents, process control documents, tooling design, process approval, modification, process rectification, and management.
3. Equipment capability: The supplier has complete mechanical processing equipment, such as casting, forging, machining, heat treatment, riveting and welding, assembly, inspection, etc., occupying a leading position in the domestic industry. It has 878 sets of various equipment, including 67 sets of precision, large and thin equipment, such as 16m gantry planer, 5m vertical lathe, EXA-500 CNC sheet cutting machine, φ 100 rocker drilling machine, CO2 gas automatic protective welding production line, WB43-12 × 2000 steel plate leveling machine, HK2000 vibration aging machine, etc. There are 32 various testing equipment and 3627 measuring and testing instruments, such as XX-250B X-ray flaw detector, CTS-26 ultrasonic flaw detector, SHT-162 paint mold thickness gauge, etc.
4. Manufacturing and inspection capabilities
4.1 Basic Projects
4.1.1 Inspect and test various steel materials, outsourced parts, and supporting components used in the crane according to the operation manual, conduct chemical analysis or mechanical performance tests on various steel materials, and use Q235-B material for main components such as the main beam and end beam.
4.1.2 After welding and forming the metal structural components of the crane, sandblasting treatment shall be carried out and anti rust paint shall be sprayed.
4.1.3 All inspection items of the crane shall be inspected item by item before leaving the factory during the production and manufacturing process. Only when all the specified testing items of the whole machine are qualified can it be shipped, ensuring a 100% pass rate.
4.2 Structural components
4.2.1 Flat Plate Cutting Control: All steel plates are corrected and stress relieved using a large flat plate machine, with a quality level effect of waves ≤ 3mm. The upper and lower flange plates, web plates, and small frame cover plates of the main beam and end beam are cut using CNC cutting machines, while the rest of the plates are cut using shear cutting.
4.2.2 Welds: The butt welds of the upper and lower flange plates and web plates of the main beam and end beam are welded using NZA-1000 submerged arc automatic welding machine. After positioning welding, the four corner welds are welded using CO gas automatic protection welding production line to ensure uniform heating of the structural components, deformation within the control range, and ultimately the docking of the bridge frame. They are welded flat on the reverse fixture. The welding of other metal structural components such as the trolley frame is carried out using CO gas shielded welding. In addition to meeting the surface quality requirements, the welds must also undergo 100% radiographic or ultrasonic testing in accordance with the requirements of GB/T14405-1993 standard. After the main components are welded and formed, they undergo vibration aging treatment.
4.2.3 Arch control of main beam: Determine the arch curve of the main beam based on the variables during its welding and bridge assembly. Input the equation f=f (1-4x/S) and use a CNC cutting machine to cut out the web plate to ensure that the arch of the crane main beam meets the standard requirements.
4.3 Castings
The castings are subjected to chemical composition analysis and mechanical performance testing before being fired, and are inspected according to the relevant provisions of the "Raw Material Quality Inspection System".
4.4 Processing Parts
Process inspection is carried out for machined parts, and re inspection is carried out before storage. The "three press" and "three inspection" systems are strictly implemented, and the inspection status is clearly marked on each workpiece. Unqualified parts will not be transferred to the next process, especially the hook, which must be re inspected strictly according to the inspection regulations and must be consistent with the material inspection results of the purchased hook before being processed for storage.
4.5 Heat treatment
The large and small car wheels are made of 60 # steel rolled, 65Mn, 42CrMo or ZG340-640, and quenched as a whole to ensure that the hardness of the quenched layer at a depth of 20mm is ≥ HB260, and the tread hardness is HB330~380. The gears are quenched in a 45 # or 40Cr salt furnace, and the brake wheels are surface quenched with ZG340-640 and tested using a hardness tester. For workpieces with quenching depth requirements, they are regularly dissected and inspected using cutting or machining methods every year.
4.6 Outsourced Parts
All purchased parts are sourced from well-known domestic manufacturers, and the suppliers are qualified suppliers determined through evaluation. After the purchased parts enter the factory, they shall be inspected item by item according to the "Inspection Regulations for Purchased Parts", and only after passing the inspection can they be processed for storage.
4.7 Assembly
The assembly of each working mechanism of the crane is strictly operated according to the process procedures. After the assembly is completed, in addition to item by item inspection according to the regulations, both the large and small vehicles are tested for empty operation to check their operation.