机床.金属切削机床加工过程的短期能力评估

[中文适用范围]： 本文件规定了基于对金属切削机床加工特定工件的能力的测试（即间接测试）的验收程序。它为测试条件、适用的测量系统和机床要求提供了建议。本文件与描述过程管理统计方法的 ISO 22514（所有部分）一致，并涉及这些方法在机床和一批测试件样品加工中的具体应用。本文件既不涵盖通常在测试精度性能之前进行的功能测试，也不涵盖机床安全条件的测试。附件 A 提供了与统计评估相关的附加信息，附件 B 和 C 提供了短期能力测试的协议和评估表，而附件 D 给出了一个示例。注 1 直接测试旨在调查单个机床属性，例如几何或定位精度。短期能力评估旨在证明机床具有完成特定工艺任务的能力。因此，重要的是要认识到短期能力测试仅关注制造的产品。这意味着直接测试方法更适合确定机床的误差源和对用于广泛生产范围的机床进行建设性改进；短期能力测试不太适合检测机床的误差源。因此，预计金属切削机床在加工过程中的验收短期能力评估主要在依赖于工件的专用机器上进行，例如，传输线的工作站，其过程确定的循环时间少于 10 分钟，以便一个班次至少生产 50 个工件，因为对于较小的数量，统计不确定性会急剧增加。原则上，如果满足上述统计要求，短期能力评估也可以在通用机床上进行，例如用于大批量生产的加工中心。注 2：“短期能力”是机床行业广泛使用的术语，对应于 ISO 3534-2:2006 中为正态分布规定的“过程性能指数”。 [外文原描述]： This document specifies procedures for acceptance of metal-cutting machine tools based on the tests of their capability in machining a specified workpiece (i.e. indirect testing). It gives recommendations for test conditions, applicable measurement systems and the requirements for machine tools. This document is consistent with ISO 22514 (all parts) describing statistical methods for process management and deals with the specific application of those methods to machine tools and machining of a sample batch of test pieces. This document covers neither functional tests, which are generally carried out before testing the accuracy performance, nor the testing of the safety conditions of the machine tool. Annex A gives additional information related to statistical evaluation, Annexes B and C provide agreement and evaluations forms for short-term capability tests, while Annex D gives an example. NOTE 1 Direct testing aims to investigate individual machine tool properties, such as geometric or positioning accuracy. Short-term capability evaluation is meant to prove that a machine tool has the capability to fulfil a specific process task. It is, therefore, important to recognize that the short-term capability test is focused only on the manufactured product. This means that direct testing methods are more suited for the determination of error sources on the machine tool and for deriving constructive improvements of a machine tool that is used in a wide production spectrum; a short-term capability test is less suited for detection of error sources of the machine tool. Therefore, it is expected that short-term capability evaluation for the acceptance of metal-cutting machine tools in machining processes be primarily carried out on workpiece-dependent special-purpose machines, e.g. working stations of transfer lines, with a process-determined cycle time of less than 10 min, so that at least 50 workpieces are manufactured in one shift as the statistical uncertainty increases strongly for a smaller number. In principle, short-term capability evaluation can also be performed on universal machine tools, such as machining centres used for large batch production if they meet the above-mentioned statistical requirements. NOTE 2 The term “short-term capability”, which is a widely used term in machine tool industry, corresponds to the term “process performance index” specified in ISO 3534-2:2006 for normal distribution.