Filling Material Optimization Of20Tons Hydraulic Excavator Counterweight

Counterweight is a component to keep balance of the20tons hydraulic excavator while working. The most important index of counterweight is filling weight.Counterweight is a box structure weld by metal plates, the filling material fill through the upper opening.By adjust the ratio of different filling material to manage the weight, to meet the design or drawing demands.Normally, the filling materials are: steel grit, barite, concrete and water.But the price and the SG (specific gravity) is different the materials, steel grit has the highest price and SG; barite has a lower price and a lower SG.Meanwhile, the bubble caused by filling process will affect the voidage. That is, the less bubble occurs, the lower voidage we’ll get, which means a better filling. In order to get the cost improvement, we must get the maximum usage of the counterweight inner space, by increase the ratio of barite which is cheaper and lower SG instead of expensive steel girt.The price of the counterweights is very high before the cost improvement, because they are filled manually, and we had not studied the matching of the filling materials. Meanwhile, the manual filling process isinefficient, cannot meet the future demands. In this improvement, we improve efficiency by leading in the automatic filling device and the vibration plat.In the same time, we kept adjusting the matching formula of the filling materials to get the lowest cost by repeatedly filling experiments. Because of we have different filling materials and they affect each other, we use the Multivariate Regression Analysis to calculate the best solution, first the set the voidage as the Dependent Variable, and set the ratios of steel grit, barite and water as independent variables, then built the multivariate regression model. We get the regression equationthrough dozens of experiments。The best formula is steel girt700Kg, water125Kg, water reducer4Kg. in the new the vibration plat,by using the water reducer anddefoamer, we reduced the voidage to2.23%averagely. The formula is verified by30experiments. We got1742 RMB cost reduceper counterweight, and12times of production efficiency, from8pcs by4person per day to48pcs by2person per day...