车辆与动力工程学院毕业设计说明书
375柴油机设计
摘 要
本文主要介绍375柴油机气缸盖的设计。在本次设计中，考虑到375柴油机主要应用于农业生产中的中小型机械，环境往往较为恶劣，需要内燃机具有较好的动力性能为农机产品提供足够的动力。本次设计在375柴油机基础上加大了活塞的工作行程，改球形燃烧室为W形燃烧室，使其动力性与经济性都有所提高。但由于工作行程的加大，平衡性变差，噪音与震动加大，在设计时对其采取一定的措施。燃烧系统采用直喷型，易启动，节能效果明显，可使经济性和动力性大大提高。发动机转速为3400r/min左右，12h标定功率约19kW，符合当今低速汽车对转速及功率的需求。通过参数及工艺性能的控制可使燃油消耗率保持在250g/kW.h以内。本文着重讨论了气缸盖重要部位的设计要求及特点。
本人主要任务是设计375柴油机的气缸盖，首先根据柴油机的性能指标对柴油机主要的性能参数进行了选择。然后在参照375柴油机的气缸盖结构进行结构设计。在阐述气缸盖设计过程的同时也对主要零部件的设计要点作了总结。本说明书中重点论述了375柴油机气缸盖的设计依据与设计过程。同时，对气缸盖材料的选择、冷却水道的布置、进排气道的布置以及缸盖螺栓的布置等问题也进行了讨论。
关键词： 柴油机，气缸盖，冷却水道，进气道，
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车辆与动力工程学院毕业设计说明书
THE DESIGN OF 375 DIESEL ENGINE
（CYLINDER HEAD）
ABSTRACT
This paper mainly introduces the design of the 375 diesel engine cylinder head. In this design, considering the 375 diesel engines are mainly applied in small and medium-sized machinery, agricultural production environment is bad, need often has better performance for internal machinery products provide enough power. The Diesel 375 which designed this time is on the basis of the old Diesel 375 and increasing the piston stroke, with its power performance and economical efficiency enhanced. However, because of the work itinerary increased, its balance became worse, noise and vibration also increased. So in this design, I have to take some certain measures. Combustion Chamber using injection type, easy to start, energy saving effect, and can make the efficiency and performance improved greatly. The engine speed is 3400r/min, about 19kW/12h calibration power, speed and the current low power of the car needs. Through the parameters and process performance control can make fuel consumption in 250g/kW. This paper discusses the design requirements and characteristics of the cylinder important parts。
My main task is to design 375 engine cylinder head. On the first, according to the diesel’s performance target, I should to choose the main performance mark of the diesel. Then in the light of the design of 375 diesel cylinder head to design the structure. When explained the process of the cylinder head design, I also summarized the main parts. This thesis focused on expounding the foundation and process
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车辆与动力工程学院毕业设计说明书
of the 375 diesel engine cylinder head design. Meanwhile, the cylinder head material selection, the cooling channel, intake, exhaust and the cylinder head bolts, arrangement also were discussed.
KEY WORDS： diesel engine, cylinder head , cooling channel,
intake,
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车辆与动力工程学院毕业设计说明书
目 录
第一章 前 言 .............................................................................................1
§1.1 柴油机技术概述及发展趋势 ...................... 1
§1.1.1 概述 ................................... 1 §1.1.2 柴油机技术的发展趋势 ................... 2 §1.2 我国柴油机技术的发展 .......................... 4 第二章 整体设计 ........................................................................................6
§2.1 柴油机设计的总体要求 .......................... 6
§2.1.1 内燃机的设计要求 ........................ 6 §2.1.2 内燃机设计工作中的“三化” ............. 6 §2.2 柴油机的设计要求 .............................. 7 §2.3 375柴油机简介 ................................ 8 §2.4 柴油机主要零部件的设计 ........................ 9
§2.4.1 活塞 .................................... 9 §2.4.2 连杆 ................................... 10 §2.4.3 曲轴飞轮组 ............................. 10 §2.4.4 气缸盖 ................................. 11 §2.4.5 机体组 ................................. 11
第三章 气缸盖设计 .................................................................................. 13
§3.1 气缸盖的工作条件 ............................. 13 §3.2 气缸盖的设计要求 ............................. 14 §3.3 气缸盖的材料 ................................. 15 §3.4 气缸盖结构形式的选择 ......................... 17 §3.5 气缸盖主要尺寸的确定 ......................... 17 §3.6 进、排气道的设计 ............................. 17 §3.7 冷却水道的设计 ............................... 18 §3.8 气缸盖螺栓的布置 ............................. 19
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车辆与动力工程学院毕业设计说明书
第四章 发动机的热力计算 ....................................................................... 21
§4.1 气缸盖的热力计算 ............................. 21
§4.1.1 参数选择 ............................... 21 §4.1.2 燃料燃烧的热力计算 ..................... 21 §4.1.3燃烧过程的热力计算 ...................... 22
第五章 结 论 .......................................................................................... 29 参考文献 ...................................................................................................... 30 致谢 ............................................................................................................... 31
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