표제지

목차

ABSTRACT 9

Ⅰ. 서론 11

1.1. 연구 배경 및 목적 11

1.2. 연구동향 15

1.2.1. 엔진 성능 개선 연구 16

1.2.2. 엔진 주변장치 개선 연구 17

1.2.3. 변속기 개선 연구 18

1.3. 주요 연구대상 19

1) 변속기 어셈블리 (transmission assembly) 19

2) 기어트레인 시스템 (gear/shaft) 19

3) 케이스류 (clutch housing/TM case/rear case) 19

Ⅱ. 이론적 배경 20

2.1. 기어트레인 시스템 평가 방법 20

2.1.1. 기어 강도 평가 20

2.1.2. 기어 손상률 평가 30

2.2. 케이스 형상 최적화 방법 32

Ⅲ. 본론 34

3.1. 시스템 개념설계 34

3.1.1. 성능 요구 조건 분석 34

3.2. 기본설계 36

3.2.1. 파워트레인 운동 성능인자 분석 37

3.2.2. 변속기 내부 기어 경량화에 따른 연비 변화 45

3.3. 설계검증 49

3.3.1. 기어류 구조해석 49

3.3.2. 기어 시스템 구조해석 58

3.3.3. 기어 경량화 및 개선 설계 65

3.3.4. 케이스 구조해석 및 개선 설계안 도출 71

3.3.5. 개선 설계안 연비 상승효과 비교 86

3.4. 상세설계 88

3.5. 시제품 제작 89

3.6. 성능시험 90

3.6.1. 구동 토크 시험 90

3.6.2. 동력전달효율 시험 94

3.6.3. Dynamometer 내구 시험 100

3.6.4. 연비 측정 시험 102

3.7. 실차시험 104

1) 실차시험 방법 104

2) 실차시험 결과 108

3.8. 변속기 장착 전기구동(TMED) 상용차 적용 비교 109

3.8.1. 전기구동 상용차 개요 109

3.8.2. 동력원 선정 및 비교 111

Ⅳ. 결론 115

1) 파워트레인 운동 성능인자 분석 115

2) 다단 자동화 수동변속기 설계 검증 115

3) 다단 자동화 수동변속기 시제품 성능 시험 116

4) 변속기 장착 전기구동 상용차 적용 비교 116

참고문헌 117

Table 1.1. Comparison of performance and feature by transmission type 13

Table 1.2. Improvement of the fuel economy by engine items 16

Table 1.3. Improvement contribution of fuel economy by element in the coolant system 17

Table 3.1. Required specifications of the 12-speed AMT 35

Table 3.2. Calculation of fuel consumption 46

Table 3.3. Comparison of fuel efficiency 48

Table 3.4. Material properties of SCM822H 52

Table 3.5. The results of structural analysis of the gears 57

Table 3.6. Load conditions of analysis in Rornax DESIGNER 61

Table 3.7. Input conditions of speed 61

Table 3.8. Contact and bending stress at the 1st speed main gear and counter gear 63

Table 3.9. Compare with AGMA 2001 and the result of Romax DESIGNER 64

Table 3.10. Structural analysis of the initial model and modified model 69

Table 3.11. Compare with the initial model and the modified model of gears 70

Table 3.12. Material properties of AC4B-T6 76

Table 3.13. The results of the structural analysis of cases 77

Table 3.14. Effect for lightweight of the transmission mass 86

Table 3.15. Comparison of fuel consumption by each speed 87

Table 3.16. Test conditions of driving torque test 91

Table 3.17. Test conditions of power transfer efficiency test 95

Table 3.18. Test conditions of durability test 100

Table 3.19. Specifications of test vehicle for fuel consumption 102

Table 3.20. The test results of fuel consumption 103

Table 3.21. Specifications of test vehicle for load test 105

Table 3.22. Average speed for each speed of 12-speed AMT 111

Table 3.23. Effect for lightweight of the transmission mass in TMED 114

Fig. 1.1. Overview of automotive powertrain 11

Fig. 1.2. System sensitivity of powertrain 15

Fig. 2.1. Load of gear tooth 22

Fig. 2.2. Allowable bending stress, sₐₜ 23

Fig. 2.3. Bending strength stress cycle factor, YN[이미지참조] 25

Fig. 2.4. Pitting resistance stress cycle factor, ZN[이미지참조] 25

Fig. 2.5. Allowable contact stress, sac[이미지참조] 27

Fig. 2.6. Hardness ratio factor, CH[이미지참조] 29

Fig. 2.7. Cumulative damage graph in the transmission 31

Fig. 2.8. Design variables a, b, and c for a solid design element 33

Fig. 3.1. Simplified diagram of the planetary gear system(1~6 speed, reverse speed) 39

Fig. 3.2. Simplified diagram of the planetary gear system(7~12 speed) 39

Fig. 3.3. Diagram of the multi-range transmission 40

Fig. 3.4. BSFC of the diesel engine (11,000 cc) 46

Fig. 3.5. Power delivery of 12-speed AMT 50

Fig. 3.6. FEM for gears 51

Fig. 3.7. Boundary conditions for structure analysis 53

Fig. 3.8. Structural analysis of the initial design 56

Fig. 3.9. Modeling of the gear assembly using Romax DESIGNER 60

Fig. 3.10. Result graphs of the 1st main gear 63

Fig. 3.11. Modified modeling for the low gear of the main shaft 66

Fig. 3.12. Modified modeling for the low gear of the counter shaft 66

Fig. 3.13. Structural analysis of the modified design 68

Fig. 3.14. FEA process of transmission cases 72

Fig. 3.15. Specification of size of the 12-speed AMT 72

Fig. 3.16. Load positions of bearing 73

Fig. 3.17. Boundary conditions of the 12-speed AMT case 74

Fig. 3.18. Load conditions of the clutch housing 75

Fig. 3.19. Load conditions of the TM case 75

Fig. 3.20. Load conditions of the rear case 76

Fig. 3.21. The FEA results of the AMT case 79

Fig. 3.22. Shape optimization of the 12-speed AMT 82

Fig. 3.23. The result of shape optimizations 83

Fig. 3.24. The modified cases 83

Fig. 3.25. Structural analysis of the modified model 85

Fig. 3.26. Detail design of the 12-speed AMT 88

Fig. 3.27. Experimental products 89

Fig. 3.28. Test devices for driving torque test 91

Fig. 3.29. The results of the driving torque test for the 12-speed AMT 93

Fig. 3.30. The results of the power transfer efficiency test for the 12-speed AMT 99

Fig. 3.31. Durability test for the 12-speed AMT 101

Fig. 3.32. Test devices for fuel consumption 103

Fig. 3.33. PG(Proving Ground) test 106

Fig. 3.34. Road test 107

Fig. 3.35. The results of PG test and road test 108

Fig. 3.36. Motor efficiency map of the 340 kW motor 112

Fig. 3.37. T-N curve of the 340 kW motor 112

Fig. 3.38. Performance curve of diesel engine in commercial vehicle 113