Under heavy-duty working conditions such as mines and large-scale earth and stone projects, loaders carry out high-intensity and continuous shoveling and transportation operations, and their various components are subjected to huge alternating loads and shock and vibration.As the key component for balancing the force, the reliability of the connection structure between the counterweight and the frame is directly related to the safety and continuous operation ability of the whole machine.Under heavy-duty impact, if the connection structure fails (such as bolt fracture, bracket welding), it may cause the counterweight to fall off, causing the center of gravity of the vehicle to move forward violently in an instant, which can easily cause a major accident that capsizes forward, with unimaginable consequences.Therefore, for heavy-duty working conditions, special strengthening of the counterweight connection structure and the establishment of strict regular inspection standards are a vital part of equipment safety management.
 

The strengthening of the reliability of the connection structure is a system engineering.First of all, at the design and material level, the connecting bracket (or counterweight bracket) should be made of high-strength steel plate, and is usually designed as a box-shaped or stable structure with reinforcing bars to have excellent bending and torsional stiffness.The connection weld between it and the main frame must be fully permeable bevel welding to ensure that the stress can be smoothly transmitted to the main structure of the frame.Secondly, in the connection method, high-strength alloy steel bolts are generally used for fastening.The strength level of these bolts (such as level 10.9 or Level 12.9) must be clearly required and installed in strict accordance with the torque and fastening sequence provided by the manufacturer (such as diagonal tightening).Sometimes anti-loosening washers or thread locking agents are used on the binding surface to prevent the bolts from loosening under long-term vibration.In addition, some designs will set positioning pins or stops at the joints, which are easy to assemble and align, and can also bear part of the shear force and reduce the load on the bolts.
 

The establishment and implementation of a set of scientific regular inspection standards and methods is the key guarantee to transform design reliability into continuous operation safety.Inspection should be divided into three levels: daily inspection, regular professional inspection, and post-inspection under special working conditions.Daily inspections are completed by the operator, mainly relying on visual vision and simple tools to check whether the visible bolts are significantly loose or missing, and whether the bracket welds have cracks visible to the naked eye.Regular professional inspections should be included in the medium-term or annual maintenance plan of the equipment, and professional maintenance personnel should use professional tools to perform them.This includes: using a calibrated torque wrench to conduct a census or spot check of the preload of all connecting bolts; using a magnifying glass or weld inspection ruler to conduct a detailed visual inspection of key force welds; for heavy-duty equipment, you can even consider every certain operating hours (such as 5000-10000 hours), hire a professional organization to perform non-destructive flaw detection of the connecting bracket (such as magnetic particle flaw detection or ultrasonic flaw detection) to find microscopic fatigue cracks on the surface or near the surface.In addition, after the equipment has experienced an unusually violent impact (such as shoveling super hard materials causing the vehicle to shake violently) or a collision of related parts, additional inspections of the counterweight connection structure should be carried out immediately.Through this kind of multi-level and standardized inspection system, the potential risks of the connection structure can be contained in the bud, and the foundation of this “power pioneer” can always be firmly established under heavy-duty tests.