The installation of GB QU70 crane rails needs to follow strict specifications and steps to ensure the safety and stability of crane operation. The following are the specific steps and key points of its installation:
Preparation before installation
Check the quality of the rails: Check the appearance of the QU70 crane rails against the GB standard to ensure that there are no obvious cracks, bubbles, inclusions and other defects. Measure the dimensions of the rails, including height, width, head radius, etc.
| Parameters of QU70 Crane rail | |||||||
| type | weight(mm) | material | length(m) | ||||
| QU70 | 52.8 | U71Mn | 12 | ||||
| rail height(mm) | bottom width(mm) | head width(mm) | web thickness(mm) | ||||
| 120 | 120 | 70 | 28 | ||||
Clean the base surface: Clean the base surface where the rails are installed, remove oil, dust, debris, etc., and ensure that the base surface is flat and solid. Use a level to measure the flatness of the base surface, requiring the flatness error within each meter to not exceed 2mm.
Prepare installation tools: Prepare the tools required for installation, such as crane, wrench, screwdriver, level, feeler gauge, pull rope, etc.
Positioning and laying out
Determine the center line of the track: According to the design requirements of the crane and the structure of the plant, use measuring instruments to accurately mark the center line of the crane track on the foundation. Set a center mark point at a certain distance (such as 5-10 meters), and use a pull rope to connect these points to form a clear track center line.
Determine the installation reference point: Set the installation reference point at both ends and the appropriate position in the middle of the track to control the elevation and levelness of the rail. The elevation of the reference point should be accurately measured and adjusted according to the design requirements, and the allowable error should be controlled within ±1mm.
Rail laying
Lifting the rail: Use a crane to lift the QU70 rail to the vicinity of the installation location. Pay attention to keeping the rail stable during the lifting process to avoid collision and deformation.
Place the rail: Place the rail section by section on the foundation according to the position of the track center line and the installation reference point. A certain gap should be reserved between the rails, generally 1-2mm, to accommodate the expansion and contraction of the rails caused by temperature changes.
Adjust the position of the rails: Use tools such as crowbars and jacks to fine-tune the position of the rails so that the center line of the rails coincides with the pre-marked center line, with an error of no more than ±2mm. At the same time, use a level and a feeler gauge to check the levelness of the rails, and adjust them by inserting a pad of appropriate thickness at the bottom of the rails so that the levelness of the rails does not exceed 1.5mm per meter.
Rail connection
Welding connection: For GB QU70 crane rails, welding is usually used for connection. Before welding, the welding parts of the rails need to be cleaned to remove impurities such as oil and rust. Welders should have the corresponding qualifications. After welding is completed, the welds are visually inspected. There should be no defects such as pores, slag inclusions, cracks, etc. The height and width of the welds should meet the design requirements.
Fishplate connection: In some cases, fishplates may also be used to connect rails. Place the fishplate at the end of the rail and fasten the fishplate to the rail with bolts. The tightening torque of the bolts should meet the specified requirements, generally 300 - 500N・m. After the connection is completed, check the fit between the fishplate and the rail, and the gap is required to be no more than 0.5mm.
Fix the rail
Install the pressure plate: Install the pressure plate on both sides of the rail, and fix the rail to the foundation through the pressure plate. The spacing of the pressure plate is generally 500 - 800mm, and the specific spacing should be determined according to factors such as the load capacity of the crane and the length of the track. There should be a rubber pad or other elastic material between the pressure plate and the rail to reduce vibration and noise.
Tighten the bolts: Use a wrench to tighten the bolts on the pressure plate so that the pressure plate is firmly pressed on the rail. During the tightening of the bolts, a symmetrical tightening method should be adopted to ensure that the rail is evenly stressed.
Post-installation inspection
Track geometry inspection: After installation, use the measuring tool again to check the geometric dimensions of the track, such as the center line, elevation, levelness and gauge. The deviation of the track center line should not exceed ±3mm, the elevation error should be controlled within ±2mm, the levelness should not exceed 3mm in the full length, and the gauge error should be ±2mm.
Rail surface quality inspection: Check whether the rail surface is damaged, deformed, worn, etc. If there are defects, they should be repaired or replaced in time. Touch the rail surface with your hand, it should feel smooth, without obvious bulges or depressions.
Connection inspection: Check whether the welding part of the rail or the fishplate connection part is firm, whether the weld has cracks, pores and other defects, and whether the fishplate bolts are loose. Perform flaw detection on the connection parts to ensure that the connection quality meets the requirements.
Through the above steps and methods, the installation of GB QU70 crane rails can be completed to meet the operation requirements of the crane and ensure the safe and stable operation of the crane. During the installation process, relevant national standards and specifications must be strictly observed to ensure the installation quality.