技术要求在零件图上的标注

技术要求在零件图上的标注 HOMEPAGE. Opening of the company's extranet, every employee in the company's various point access to information on the INTERNET network ... Nodes can be extended to 1000M, support shared communications and virtual network technology, to form a local area network system. Wide area network access system should be applied according to the specific requirements of local area network system, and plant wide area network connections, including wide-area public networks, 第八章--第三讲 技术要求在零件图上的标注(2) 一、知识要点 1(极限与配合 2(形状和位置公差 二、教学方法 本讲在教学中要突出基本概念和基本技能的培养，要结合实际的零件生产进行教学，重点概念要讲清楚，如公差和偏差的区别、配合性质、基准制等，然后结合实例讲解精度和标注问。 三、课前准备 准备几张生产上使用的零件图，最好是有零件图纸和实际零件配合在一起，各种精度的零件和图纸尽量齐全。 四、教学内容 1. 极限与配合 1(互换性 成批生产的机器在进行装配时，要求一批相配合的零件，不经任何修配，任取一对装配起来，就能达到设计的工作性能要求，零件间的这种性质称为互换性。 2(极限与配合的基本概念和名词术语 基本尺寸:设计时确定的尺寸称为基本尺寸，如图8—27中的φ50。 最大极限尺寸:零件实际尺寸所允许的最大值。 最小极限尺寸:零件实际尺寸所允许的最小值。 上偏差:最大极限尺寸和基本尺寸的差。孔的上偏差代号为ES，轴的上偏差代号为es。 下偏差:最小极限尺寸和基本尺寸的差。孔的下偏差代号为EI，轴的上偏差代号为ei。 公差:允许尺寸的变动量，公差等于最大极限尺寸和最小极限尺寸的差。 HOMEPAGE. Opening of the company's extranet, every employee in the company's various point access to information on the INTERNET network ... Nodes can be extended to 1000M, support shared communications and virtual network technology, to form a local area network system. Wide area network access system should be applied according to the specific requirements of local area network system, and plant wide area network connections, including wide-area public networks, HOMEPAGE. Opening of the company's extranet, every employee in the company's various point access to information on the INTERNET network ... Nodes can be extended to 1000M, support shared communications and virtual network technology, to form a local area network system. Wide area network access system should be applied according to the specific requirements of local area network system, and plant wide area network connections, including wide-area public networks, 图8—27 公差与配合的基本概念 3(公差带图 用零线示基本尺寸，上方为正，下方为负，用矩形的高表示尺寸的变化范围(公差)，矩形的上边代表上偏差，矩形的下边代表下偏差，距零线近的偏差为基本偏差，矩形的长度无实际意义，这样的图形叫公差带图。如图8—28所示。 图8—28 公差带图 4(标准公差和基本偏差系列 标准公差是由国家标准规定的公差值，其大小由两个因素决定，一个是公差等级，另一个是基本尺寸。国家标准(GB/T1800)将公差划分为20个等级，分别为IT01、TI0、IT1、IT2、IT3……IT17、IT18。其中IT01精度最高，IT18精度最低。 轴和孔的基本偏差系列代号各有28个，用字母或字母组合表示，孔的基本偏差代号用大写字母表示，轴的基本偏差代号用小写字母表示。如图8—29所示。基本偏差决定公差带的位置，标准公差决定公差带的高度。 HOMEPAGE. Opening of the company's extranet, every employee in the company's various point access to information on the INTERNET network ... Nodes can be extended to 1000M, support shared communications and virtual network technology, to form a local area network system. Wide area network access system should be applied according to the specific requirements of local area network system, and plant wide area network connections, including wide-area public networks, HOMEPAGE. Opening of the company's extranet, every employee in the company's various point access to information on the INTERNET network ... Nodes can be extended to 1000M, support shared communications and virtual network technology, to form a local area network system. Wide area network access system should be applied according to the specific requirements of local area network system, and plant wide area network connections, including wide-area public networks, 图8—29 基本偏差系列 5(配合类别 基本尺寸相同，相互结合的轴和孔公差带之间的关系称为配合。按配合性质不同可分为间隙配 合、过盈配合和过渡配合，如图8—30所示。 HOMEPAGE. Opening of the company's extranet, every employee in the company's various point access to information on the INTERNET network ... Nodes can be extended to 1000M, support shared communications and virtual network technology, to form a local area network system. Wide area network access system should be applied according to the specific requirements of local area network system, and plant wide area network connections, including wide-area public networks, HOMEPAGE. Opening of the company's extranet, every employee in the company's various point access to information on the INTERNET network ... Nodes can be extended to 1000M, support shared communications and virtual network technology, to form a local area network system. Wide area network access system should be applied according to the specific requirements of local area network system, and plant wide area network connections, including wide-area public networks, 图8—30 配合类别 6(基准制 采用基准制是为了统一基准件的极限偏差，从而达到减少零件加工定值刀具和量具的规格数量， 国家标准规定了两种配合:基孔制和基轴制。如图8—31所示。 HOMEPAGE. Opening of the company's extranet, every employee in the company's various point access to information on the INTERNET network ... Nodes can be extended to 1000M, support shared communications and virtual network technology, to form a local area network system. Wide area network access system should be applied according to the specific requirements of local area network system, and plant wide area network connections, including wide-area public networks, HOMEPAGE. Opening of the company's extranet, every employee in the company's various point access to information on the INTERNET network ... Nodes can be extended to 1000M, support shared communications and virtual network technology, to form a local area network system. Wide area network access system should be applied according to the specific requirements of local area network system, and plant wide area network connections, including wide-area public networks, 图8—31 基准制 7(偏差代号的标注 在零件图中线性尺寸的偏差有三种标注形式，:只标注上、下偏差、只标注偏差代号、既标注 偏差代号，又标注上、下偏差，但偏差用括号括起来。在装配图上一般只标注配合代号，配合代号 用分数表示，分子为孔的偏差代号，分母为轴的偏差代号。如图8—32所示。 HOMEPAGE. Opening of the company's extranet, every employee in the company's various point access to information on the INTERNET network ... Nodes can be extended to 1000M, support shared communications and virtual network technology, to form a local area network system. Wide area network access system should be applied according to the specific requirements of local area network system, and plant wide area network connections, including wide-area public networks, HOMEPAGE. Opening of the company's extranet, every employee in the company's various point access to information on the INTERNET network ... Nodes can be extended to 1000M, support shared communications and virtual network technology, to form a local area network system. Wide area network access system should be applied according to the specific requirements of local area network system, and plant wide area network connections, including wide-area public networks, 图8—32 装配图中偏差的标注 (二)形状和位置公差 1(形状和位置公差的基本概念 在生产实际中，经过加工的零件，不但会产生尺寸误差，而且会产生形状和位置上的误差。如图8—33所示。 图8—33 (a)形状误差 (b)位置误差 形状误差是指实际表面和理想几何表面的差异。 位置误差是指相关联的两个几何要素的实际位置相对于理想位置的差异。 形状和位置误差的允许变动量称为形状和位置公差，简称形位公差。 2(形状和位置公差特征项目的规定符号 形状和位置公差特征项目的规定符号见表7—6所示。 表7—6:形状和位置公差的名称和符号 HOMEPAGE. Opening of the company's extranet, every employee in the company's various point access to information on the INTERNET network ... Nodes can be extended to 1000M, support shared communications and virtual network technology, to form a local area network system. Wide area network access system should be applied according to the specific requirements of local area network system, and plant wide area network connections, including wide-area public networks, HOMEPAGE. Opening of the company's extranet, every employee in the company's various point access to information on the INTERNET network ... Nodes can be extended to 1000M, support shared communications and virtual network technology, to form a local area network system. Wide area network access system should be applied according to the specific requirements of local area network system, and plant wide area network connections, including wide-area public networks, 3(形状和位置公差的标注 在机械图样中，形位公差采用代号的形式标注，代号由公差框格和带箭头的指引线组成，如图 8—34所示。 图8—34 形位公差代号 形位公差的标注示例如图8—35所示。 HOMEPAGE. Opening of the company's extranet, every employee in the company's various point access to information on the INTERNET network ... Nodes can be extended to 1000M, support shared communications and virtual network technology, to form a local area network system. Wide area network access system should be applied according to the specific requirements of local area network system, and plant wide area network connections, including wide-area public networks, HOMEPAGE. Opening of the company's extranet, every employee in the company's various point access to information on the INTERNET network ... Nodes can be extended to 1000M, support shared communications and virtual network technology, to form a local area network system. Wide area network access system should be applied according to the specific requirements of local area network system, and plant wide area network connections, including wide-area public networks, 图8—35 形位公差标注示例 图8—35形位公差标注示例的各个形位公差代号含义说明如表7—7所示。 表7—7:综合标注示例说明 HOMEPAGE. Opening of the company's extranet, every employee in the company's various point access to information on the INTERNET network ... Nodes can be extended to 1000M, support shared communications and virtual network technology, to form a local area network system. Wide area network access system should be applied according to the specific requirements of local area network system, and plant wide area network connections, including wide-area public networks,