注射成型零件的几何尺寸和公差

于2022年4月11日发布 金沙9999js

The world of quality in the manufacturing industry is a big, complex place. From industry certifications to dimensional verification and process validation, 有很多变量需要考虑. 在大多数情况下, these quality processes are critical to ensuring stability in each manufacturing process before moving on to produce components in higher volumes. Basically, it means measure twice, or 30 times in the case of a CpK, so you only have to cut once. 但, 正如金沙9999js所知, 一个典型的组件可以有许多特性, 维, 以及可能造成或破坏零件性能的公差. In this blog, we’re going to address Geometric Dimensioning and Tolerancing (GD&T),最近升级到金沙9999js的 Critical-to-Quality(概念不同)的过程, and we’ll outline the various feature and dimensional measurement capabilities available, 以及这些特性给金沙9999js的客户带来的透明性.

GD是什么&T?

GD&T is an industry standard symbolic language used to communicate allowable geometric represents the evolution of the CTQ quality inspection process. When you submit a 3D CAD model, it gives us a strong indication of the specs for your part. GD&T更进一步, 为金沙9999js提供特定的功能, 例如位置或平面, 你想让金沙9999js测量. 具体来说,你可以为金沙9999js提供动力局&下面列出的T特性.


位置

用轴表示, 点或飞机, position defines how much variation a feature 可以 have from a specified exact true location. The tolerance is a 2- or 3-dimensional tolerance zone that surrounds the true location where a feature must lie. 这意味着你将有一个确切的点 应该 是,你的容忍度指定了这个特性离你有多远 可以 be. This is usually called out as a diameter to represent a circular or cylindrical tolerance zone.


平面度

这是一个衡量表面平坦程度的简单特征. It’s important to note that this symbol references flatness of a surface regardless of other features or datums that might exist on the part. 由两个平行平面定义的, this feature is useful to call out on features that need to be uniformly flat without adjusting other 维 on the drawing.


平直度

平直度 可以 be defined as either surface straightness or derived median line (DML) straightness. Surface straightness is the standard form and is used to verify uniform straightness across a feature or surface. This is often applied to flat features but 可以 also be applied to cylindrical features. In both cases, this feature is defined by the variance of a surface within a specific line.

DML直线度不同于表面直线度, 因为它适用于零件中心轴的弯曲, 通常一个圆柱体.  在这种情况下, DML becomes a 3-dimensional tolerance which defines how far the center axis of a part may bend or twist.


循环

循环, 或圆, defines the allowable variance between a circular feature and a true circle. 这个二维公差定义了圆的形状, 为了证明这个圆不是长方形的, 广场, 或者是不圆的. Like flatness, circularity is measured independently from other features or datums.

循环gd&t


同心

同心, 或同轴度, defines the central derived median points of a referenced feature to a datum axis. 这个特性很复杂, because it relies on mathematically derived median points instead of the physical axis of a surface or feature.


圆柱度

圆柱度定义了物体与真正圆柱的接近程度. This 3-dimensional tolerance defines roundness and straightness of the overall form of a cylindrical feature. 再一次, 这是独立于任何其他基准进行测量的, and forms a cylindrical boundary around the object that the 3-dimensional feature must lie in.


并行性

并行性

并行性 describes the orientation of one referenced feature to a datum surface or line. This commonly relates the orientation of one surface plane parallel to another datum plane in a 3-dimensional tolerance zone. This effectively means that the tolerance controls the angle between 2 features by controlling where the surface 可以 lie.

垂直

垂直

垂直有两种:面垂直和轴垂直. It is defined by how close to 90 degrees a surface or line is from a datum surface or line. 在一般情况下, surface 垂直 is used to verify orientation of a one surface plane perpendicular to the datum plane. 轴垂直度可作为圆形特征的参考, and defines the cylindrical boundary where the axis of the referenced feature must be.

配置文件

曲面轮廓

曲面的轮廓定义了三维公差带, 通常以高级曲线或形状的形式出现. 因此, 在曲面上进行轮廓测量时, 比如鱼片, 半径的整个表面必须落在公差带内. 在这种情况下, any variance inside or outside of the tolerance must fall within the surface 配置文件 tolerance.

As we referenced at the beginning of this blog, the addition of these GD&T features to our automated inspection capabilities provides an added layer of transparency to the quality control process. If you would like us to inspect any of the previously mentioned features on your next project, 只需参考金沙9999js的检查概述, 金沙9999js的应用工程师, 或者和你的客户经理谈谈.

标记: 质量, 注塑