2017 International Conference on Computer Network, Electronic and Automation (ICCNEA 2017) 76 Optimization of Matching on Torque Converter with Engine Based on Improved Radar Chart Method Zhenbao Wang College of mechanical Science and Engineering Jilin University Changchun , China E-mail: wangzhenbao1989 @126.com Sicheng Qin College of mechanical S cience and Engineering Jilin University Changchun, China E-mail: qsc925@hotmail.com Abstract—In order to comprehensively evaluate the performance of matching between engine and torque converter, a series of matching evaluation indexes were developed according to the ideal matching principle and a standardized treatment for every index was put forward. Considering the different importance of each indexes in different applications, weight of each index was given by using comprehensive method, The evaluati on method of the hydraulic torque converter and engine matching was established based on the improved radar map method. The objective function was constructed based on the sum of each evaluation index and the perimeter of radar map. With a hydraulic torque converter of ZL50 loader as an example, the effective diameter of circular circle on hydraulic torque converter was optimized in view of the shovel loading cycle condition. The original size of torque converter effective diameter was 0.340 m. After optimi zation, the effective diameter of hydraulic torque converter was 0.350 m, and the matching performance of engine and torque converter was increased by 7.4%. The results show that the optimal matching scheme can be improved by using the improved radar map m ethod. Keywords -Torque converter; Matching ; Improved radar chart method; Optimization; Whee l loader I. INTRODUCTION Hydraulic torque converter as a kind of hydraulic transmission device works with the engine in the course of work. After the matching of hydrau lic torque converter and engine, it can be considered as a new power installation and its performance greatly depends on whether the matching of them is reasonable. Thus, it is necessary to make a comprehensive evaluation for the performance of the joint work [1, 2]. Aiming at the deficiency existing in the matching evaluation method of engine and hydraulic torque converter, this paper makes a further improvement on the traditional radar chart [3, 4]. Through the formulation of dimensionless matching evalua tion index and the empowerment by principal component analysis, this paper establishes the comprehensive evaluation method of the matching of a hydraulic torque converter and engine. Based on it, the objective function is constructed. And aiming at shovel mucking drive cycle, the diameter of the effective circulating circle of the hydraulic torque converter of ZL50 loader is optimized. II. EVALUATION INDEX OF MATCHING PERFORMANCE According to the matching principle of hydraulic torque converter and engine, this paper selects five evaluation indexes of matching performance and standardizes each index, which is shown in table I [5, 6]. TABLE I. EVALUATION INDEXES OF MATCHING PERFORMANCE Evaluation indexes Formula Maximum torque output coefficient 1a 1 maxTT Maximum power output coefficient 2a 1 max()eH PP Width of the efficient workspace 3a 2 1 max()wwn n n Power output coefficient 4a 1()eH PP Coefficient of fuel consumption 5a max max min( ) ( )e g g g g In the table I: 1Trefers to the crossover point torque between load parabola and engine ’s net torque curve when the transmission ratio of hydraulic torque converter 0i ; maxT refers to the maximum net output torque of engine; eHP refers to the maximum net output power o f engine; max refers to the peak efficiency of the hydraulic torque converter; 1P refers to the maximum output power of the hydraulic torque converter; 1wn and 2wn refer to the corresponding tur bine spe