Research On The Stability Of Backhoe Hydraulic Excavator Based On The Influence Of The Ratio Of Normal And Tangential Digging Resistance

Excavator is a common and important construction machinery. It plays animportant role in energy exploitiom,transportation construction, national defenseconstruction,irrigation and other earthwork construction. With the continuousdevelopment of national economy, especially the investment on construction ofrailway and irrigation works,the excavator has shown huge roles in the nationaleconomy increasingly. Therefore, it is meaningful to emphasize and accelerate itsimprovement and innovation and improve the quality of productions stability to satisfythe users for speeding up modernization construction.The stability of excavator refers to the ability against overturning excavator underits own weight and external loads. Therefore, the stability conditions affect the servicecapability, reliability and safety of excavator directly. During the analysis of fore-rakestability, the theoretical calculation results are stable but the actual mining operationare opposite.The result shows that the ratio of normal and tangential digging resistance(marked as λ for short) has great influence on the stability of complete appliance. Inthis paper, stability mechanics model of several typical operating conditions wereestablished. Considering the effect of the Ratio of normal and tangential diggingresistance, optimization design of the stability of backhoe hydraulic excavator wascarried on. The relevant parameters of counterweight can be obtained, and provide atheoretical basis for the design of excavator.The main contents of this paper are listed as follows.①Analyzes and summarizes the mining characteristics and structure form of thebackhoe hydraulic excavator,and via doing mechanical analysis and kinematicanalysis on the boom,arm and bucket,creates the mathematical model of the hingepoint and forces model of the working device.②By taking excavator working which weights21tons as the research object,analyzes fore-rake stability by using self-developed software, and the result that theratio of normal and tangential digging resistance has great influence on the stability ofcomplete appliance is obtained.③Analyzes many main working conditions, establishes the mechanical model ofstability of the typical working conditions. ④Selects the appropriate optimization parameters and the objective function, anddevelops the program of optimization of the stability of backhoe hydraulic excavatorbased on the influence of the ratio of normal and Tangential Digging Resistance usingVisual Basic6.0program.⑤Using self-developed optimization design software, optimizes the stability ofthe backhoe hydraulic excavator. The scheme obtained was compared with the stabilityof the situation before optimization. The result meets the working requirement whichproves the validity and feasibility of the method.