| Based on the restrictions of domestic truck tonnage and the company’s production needs,according to market demand,an underground dump truck with a load capacity of20 tons was designed.The design is based on the principle of reducing the height of the vehicle,reducing the dead weight and increasing the load,inheriting the advantages of the existing models and reducing the defects.Strive for standardization of parts,generalization of components,and product serialization.The structure of the truck frame of the transportation truck is simpler,the hopper capacity is increased,the height of the vehicle is lowered,and the processing is more convenient.The main research contents are as follows:Introduce the development status and development trend of 20 tons underground mining trucks at home and abroad.According to the actual working conditions,the appropriate engine,torque converter,gearbox,drive shaft and drive axle are selected.Taking the YJ375 torque converter as an example,the improve of structure and working principle of the torque converter are briefly introduced.A reasonable hinged part is designed.In the final design,the hinge is a tight joint and the lower hinge is a floating hinge.The hinged joint connects the front and rear frames into a rigid body to prevent the upper and lower movements.The floating hinge avoids the over-positioning of the hinged part and can play a certain buffering effect.In addition to the bearings,bearing end caps and pin shafts,the other parts are universal in the upper and lower hinges,easy to replace,reducing the processing difficulty.The 20-ton underground mining truck was subjected to force analysis,which was divided into three different working conditions: constant speed driving,full load shock and braking.The rear frame,swing frame,slewing bearing and front frame were analyzed and calculated.The size of the force is exerted and preparation is provided for finite element analysis.In the Soildworks software,the frame model of the mining truck was chamfered,rounded and the non-load bearing and unimportant parts were omitted,and then the front and rear frames were sequentially imported into the ANSYS Workbench.The steps of material addition,meshing,load and constraint addition were carried out in sequence,and the results of finite element analysis were finally obtained.In order to improve thereliability,firstly,the upper plate of the frame is thickened to 20 mm,and the triangular reinforcing ribs are welded at the contact point between the lifting steel pipe and the rear frame,and the side plates of the frame are thickened.Secondly,the upper hinge plate and the rear frame bottom plate of the rear vehicle can also be appropriately thickened.The maximum stress on the front frame is on both sides of the front axle mounting plate,within safe limits.In order to avoid resonance of the mining truck,the modal analysis of the model of the front and rear frames is carried out.Get the tenth natural frequency and mode shape.According to the results,compared with the three external excitation frequencies,improvement measures are proposed.The left and right side plates of the rear frame are thickened from 16 mm to 20 mm,the bottom is welded with reinforcing plates,and the inner side is welded with reinforcing ribs.The front hinge plate of the rear frame is thickened to 50 mm,the upper cover of the front frame is thickened to 16mm~20mm,and the slewing bearing mounting plate is changed to 40 mm.Finally,make a summary and expectations for future development. |
