the structural shape is complex, and residual stress is inevitably generated during the manufacturing process. In order to prevent deformation of the components due to changes in residual stress during use, it is necessary to perform stress relief treatment on the completed components.
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The arrangement of vibration points should be based on the vibration aging process standard GB/T25712-20. The vibration aging exciter should be placed at a position with high rigidity and amplitude of the workpiece, and its rotating axis should be parallel to the plane where the effective zone of the vibration mode is located. The exciter should be fixed at the end angle or edge of the workpiece with high rigidity, so that small energy can be used to excite the component with large amplitude. Based on the structural shape of the foundation, we set the vibration points on the protruding plates on each side of the workpiece.
.The lifting foundation of the platform is a large structural component made of alloy steel plates with different thicknesses that are welded together. The welding amount is large, the structural shape is complex, and residual stress is inevitably generated during the manufacturing process. In order to prevent deformation of the components due to changes in residual stress during use, it is necessary to perform stress relief treatment on the completed components.
Firstly it is necessary to start from the source. The current technology is relatively advanced. When manufacturing aluminum alloy lifting platforms, which steel should be chosen for production? Because there are many corrosion-resistant steel materials now, adding chromium, nickel, etc. to ordinary steel to make stainless steel, changing the internal structure of the metal to prevent rust.
Drivers should be responsible for supervising the uniform distribution of items transported by the platform on the platform as much as possible to prevent partial loading and prohibit overloading. flat
The driver shall close and lock the movable doors at both ends of the protective fence before work, and then ring the bell to start. It is strictly prohibited to work with the movable doors of the protective fence open. In case of special circumstances during platform operation, the emergency stop switch can be used to stop the platform. However, during normal operation, it is prohibited to use the emergency stop switch to stop the platform.
Regularly check whether the operation of each mechanism is normal and whether there is any noise. If any faults are found, they must be promptly eliminated.
However, large welded structural components have the characteristics of complex morphology, large weight, large differences in residual stress size and distribution, and it is difficult to achieve good results using ordinary vibration aging technology. Therefore, it is crucial to develop a reasonable process. Therefore, they found Nanjing Juhang and our JH-700 vibration aging equipment, and requested us to develop a complete vibration aging process.
Interpretation and observation.The second method is the protective layer method, which covers the metal surface of the aluminum alloy lifting platform with a protective layer to isolate the metal products from the surrounding corrosive medium and prevent corrosion. Apply engine oil,TianjinFixed guide rail lifting platform, petroleum jelly, paint, or cover the surface of steel parts with corrosion-resistant non-metallic materials such as enamel and plastic; Using electroplating, hot plating, spray plating, etc., to coat the surface of steel with a layer that is not easily corroded
Emergency descent: Handle operation or use of manual pressure relief and activation of emergency battery system to implement emergency descent function safety net.
The second method is the protective layer method which covers the metal surface of the aluminum alloy lifting platform with a protective layer to isolate the metal products from the surrounding corrosive medium and prevent corrosion. Apply engine oil, petroleum jelly, paint, or cover the surface of steel parts with corrosion-resistant non-metallic materials such as enamel and plastic; Using electroplating, hot plating, spray plating, etc., to coat the surface of steel with a layer that is not easily corroded
The vibration frequency should be set to obtain large dynamic stress with low energy consumption, and the resonance frequency should be used to handle time dependent vibration. However, there may be one or more resonance peaks in large components, and using resonance peaks with higher peaks and lower frequencies for aging can achieve optimal results. The resonance frequency needs to be determined by trial vibration, which slowly increases the speed of the excitation motor from 0, and determines the relationship curve between the amplitude of the workpiece and the motor speed to determine the resonance point of the workpiece. According to the scanning curve, a large acceleration was obtained at 5366r/min, so 5366r/min was determined as the aging frequency.
Service first.Thermal aging stress relief is generally suitable for small workpieces, while the lifting foundation structure has a large volume and does not have a large enough annealing furnace. Using natural aging takes one year and the production cycle is too long, so neither of these two methods is feasible. After research and understanding by the manufacturer, it was found that selecting appropriate support points for large welded structural components can perform vibration aging stress relief. Therefore, the manufacturer has decided to use vibration aging for stress relief of the platform lifting foundation. Long term promotion of downgrading manufacturers, 20 year old brand, with price advantages and guaranteed quality!
?? Hidden danger investigation relies on joint efforts from all aspects:?? Construction enterprises are the main responsibility for identifying hidden dangers in construction elevators. They should strengthen daily inspections and regular inspections and carefully inspect the steel structure, safety protection devices, electrical devices, and transmission devices of construction elevators
Applicable environment: Indoor or outdoor Applicable temperature: Safety device Safety rocker: When the equipment is running and rising, mainly used for high-altitude cargo transportation between floors. With a load capacity of 1-50 tons and an elevation of 1-25 meters, also known as hydraulic elevators, can be installed indoors and outdoors. They have a high lifting height and use side mounted oil cylinders, ensuring smooth operation, low noise, convenient maintenance, and long service life. In case of power failure, manual emergency descent can be used, which is safe, convenient, fast, and practical. The pit depth is generally 15cm-30cm. Professional elevator manufacturers have high pressure resistance, and fire and high temperature resistance, Strong overload capacity, corrosion resistance radiation resistance, long service life. The top layer height is not affected, and can be customized according to the on-site environment. It is suitable for 2-3 story steel structures or concrete factories, and can be used both internally and externally.
According to GB/T25712-2010, when one of the following situations occurs in the curve related to the aging frequency it can be determined that the area covered by the effective zone of the vibration mode at that frequency has reached the aging effect: the curve rises and flattens; The curve rises, then falls, and then flattens; The resonance frequency of the a-n curve after vibration is lower than that before vibration; The bandwidth of the a-n curve after vibration narrows compared to before vibration; The resonance peak of the a-n curve after vibration exhibits fission phenomenon; The curve flattens out after descent.
The selection of vibration pickup points refers to the placement point of the sensor, which is used to measure the vibration amplitude of the workpiece. According to GB/T25712-2010, the acceleration sensor should be placed on the workpiece with a certain rigidity and a large amplitude, and its testing direction should be adjusted to be perpendicular to the plane where the effective zone of the vibration mode is located. Considering the complex structure of the lifting foundation workpiece and the uneven thickness of each component, the vibration pickup point is set in a thick area in the middle of the component.