| It is of great concern to wheel loader and diesel engine manufacturers that how to improve dynamic and economic property of wheel loader. It has great engineering practical value for research, calculation and optimization of wheel loader power matching. At present, the main power matching work of wheel loader includes:the calculation and optimization of the hydraulic mechanical transmission system, test and analysis of wheel loader's actual working cycle. Based on the engineering practical point of view, this paper focus on the calculation theory of wheel loader power matching and the method of processing road Spectrum test data. And a software targeted on wheel loader power matching was developed, and it's reliability was verified by experiment. The main contents of this study include:By reading large amount reference on the performance of vehicles and construction machinery's hydraulic mechanical transmission system, and combining technical characteristics of ZL50 wheel loader; theoretical basis, process and evaluation method of the calculation for wheel loader power matching was summarized. In addition, based on an engineering practical point of view, this paper has proposed the processing methods and calculation processes of road spectrum test data for the wheel loader.New software targeted on the power matching of wheel loader was developed using Matlab language, which can be used on calculation of wheel loader's transmission system and results processing. Compared with other software of hydraulic mechanical transmission's calculation, its main features are:firstly, the software is expanded in function. Except for the calculation of power matching, it also can process road spectrum test data according to engineering specifications, and calculate other parameters in the working cycle which are hard to measure. Secondly, the software has been improved on the algorithm. User can choose different fitting (interpolation) algorithms to adapt different input data, and the equation is solved by a more accurate and fast algorithm. The power matching performance of two kind of ZL50 wheel loader was predicted by the new software. During the calculation, combine with the characteristics of wheel loader, four programs were chose to calculate the performance of diesel engine and hydraulic torque converter working together, five cases were divided to calculate the tractive property, and four cases were divided to calculate the accelerate property. The accuracy of tractive property calculated by the software was verified by the tractive experiment data of the highest speed and the Maximum traction force in the calculation of Long-distance transport conditions. Finally, optimization schemes for these two wheel loaders were presented by evaluation and comparison the calculation result.In order to verify the practicability of this software, the wheel loader's road spectrum test data of the actual work cycle were processed and analyzed according to practical engineering application. Include the following contents:Firstly, operation region distribution of diesel engine plotted by analysis the diesel engine's operation condition was used to verify the rationality of calculated results. Secondly, the modified curves of torque and fuel consumption from the statistical average of a large number of experimental data can be used for the future work of wheel loader power matching. Thirdly, the statistical average data of working time and fuel consumption from lots of test data of working time and integral of instantaneous fuel consumption during wheel loader cycle run can be used for compare the dynamic and economic performance of the two wheel loaders. And lastly, other parameters which are hard to measure directly in the cycle run were calculated to evaluate the performance of the matching of the transmission system.The study of wheel loader power matching was carried out, and new software was developed which could improve the efficiency and reliability of power matching. |
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