发动机活塞机械加工工艺规程及钻夹具设计

摘要

机械加工工艺过程，是指用机械加工方法逐步改变毛坯的状态（形状、尺寸和表面质量），使之成为合格的零件所进行的全部过程。发动机活塞的机械加工工艺是很典型的工艺过程。活塞的机械加工工艺过程包括结构工艺性分析、毛坯的选择、基准的选择、加工余量的确定、工艺路线的拟定、工序尺寸及公差的确定和加工设备的选择等。其中，加工余量的确定需遵守一定的原则，并通过查表和计算而得；简单的工序尺寸及其公差可以根据零件图而直接得到，但复杂的需通过尺寸链的计算而得；其他步骤的确定也得遵守一定的原则。最后，要填写相关的工艺文件。

为了提高劳动生产率，保证加工质量和改善劳动条件，需要设计专用的夹具来加工。机床夹具是用来准确、迅速地确定工件与机床、刀具间的相对位置的工艺装配。在钻油孔工序中，设计了专用的钻夹具来进行加工。钻夹具的设计是完成装夹机构、分度装置、操纵机构和夹具体的设计，以及如何将这些机构装配起来形成一个完整的装配的过程。结构方案确定以后，绘制了主要的零件图和装配图。

关键词：活塞加工；工艺过程；夹具设计

Abstract

Mechanical manufacturing process is all course carrying on of changing the state of the blank (the form, size and surface quality) with mechanical manufacturing method progressively, and making it become qualified products. The mechanical manufacturing process of the engine piston is a very typical process. The mechanical manufacturing process of the engine piston includes analysis of structure, choosing block, choosing standard , confirming process size and tolerance and choosing equipment, etc. . Among them, confirming the allowance of finish must meet certain principle by checking some table and computing; The size of simple working procedure and its tolerance obtain directly according to the detail drawing, but complex must through computing size chain; Other steps also must meet certain principle. Finally, fill in relevant files.

In order to enhance the productivity, guarante the processing quality and improve working condition, needs to design the special-purpose fixture to process. The jig used on Machine tools is a tooling used to confirm work piece’s relative position with the machine tools and cutting tool exactly and rapidly. When drilling the oil hole, we design the special-purpose jig which used on drill. The process of designing jig used on drill includes designing fixture, indexing mechanism, handle mechanism, and fixture body, and how to fit them into a whole assemblage. After confirming structure plan, we should draw up the assembly drawing. This jig is simple, also the working

procedure precision request is not very high, therefore does not have to carry on the precision analysis.

Key words: piston ；process ；designing jig

目录

绪论 (1)

第一部分发动机活塞机械加工工艺规程 (2)

第1章工艺过程概述及其重要性 (2)

1．1工艺过程概述 (2)

1．1．1生产过程、工艺过程和工艺规程 (2)

1．1．2机械加工工艺过程及其组成 (2)

1．1．3设计工艺过程的基本要求 (3)

1．1．4设计工艺过程的技术依据 (3)

1．2工艺过程重要性 (4)

第2章活塞加工基础知识 (5)

2．1活塞功用和结构特点 (5)

2．2活塞的技术要求 (7)

2．3活塞的材料 (8)

第3章活塞加工工艺规程的拟定 (9)

3．1活塞的结构工艺性分析 (9)

3．2毛坯的选择 (12)

3.2.1毛坯选择原则 (12)

3.2.2铝活塞毛坯的选择 (14)

3．3定位基准的选择 (15)

3．3．1工件的定位 (15)

3．3．2基准的概念 (18)

3．3．3定位基准选择的原则 (19)

3．3．4活塞加工基准的选择 (19)

3．4加工余量的确定 (21)

3．4．1毛坯的加工余量 (21)

3．4．2工序间的加工余量 (22)

3．5加工工艺路线的拟定 (22)

3．5．1表面加工方法的选择 (22)

3．5．2加工阶段的划分 (25)

3．5．3工序集中与工序分散 (26)

3．5．4加工顺序的安排 (26)

3．6工序尺寸及公差确定 (27)

3．6．1简单的工序尺寸 (27)

3．6．2尺寸链 (28)

3．6．3活塞加工主要工序尺寸及其公差的确定 (30)

3．7加工设备的选择 (32)