GB/T 16671-2018Geometrical product specifications (GPS) -- Geometrical tolerancing -- Maximum material requirement (MMR), least material requirement (LMR) and reciprocity requirement (RPR) (English PDF)

Foreword

This standard was drafted in accordance with the rules given in GB/T 1.1-2009.

This standard replaces GB/T 16671-2009 Product Geometric Specification (GPS) Geometric tolerance maximum entity requirements, minimum entity

Requirements and Reversible Requirements, the main technical changes compared with GB/T 16671-2009 are as follows.

--- Add reference document information and further interpretation for terms and definitions;

--- Increase the scope of the size elements applicable to this standard.

This standard uses the redrafting method to modify the use of ISO 2692.2014 "product geometry specification (GPS) geometric tolerance maximum

Body Requirements (MMR), Minimum Entity Requirements (LMR), and Reversible Requirements (RPR).

There are technical differences between this standard and ISO 2692.2014, and the terms involved in these differences have been passed on the outer margins of the margins.

The vertical single line (—) is marked. The corresponding technical differences and their reasons are as follows.

---About the normative reference documents, this standard has made technical adjustments to adapt to China's technical conditions, adjustments

The situation is reflected in Chapter 2, "Regulatory Citations", and the specific adjustments are as follows.

* Replace ISO 1101.2012 with GB/T 1182-2018 modified to international standards.

This standard has made the following editorial changes.

--- Informative Appendix C, change the matrix model of ISO 14638.1995 used in the original standard to the new moment of ISO 14638.2015

Matrix model.

This standard is proposed and managed by the National Technical Committee for Standardization of Geometrical Specifications (SAC/TC240).

This standard was drafted. China Machine Productivity Promotion Center, Kuanzhi Automobile Co., Ltd., Beijing Automobile Co., Ltd., Shanghai Automotive Group

Technology Center of Co., Ltd., SAIC-GM-Wuling Automobile Co., Ltd., Zhengzhou University, Omnex (Shanghai) Consulting Co., Ltd., Xi'an

Jiaotong University, Dai Keyi (Beijing) Technology Co., Ltd., Hexagon Measurement Technology (Qingdao) Co., Ltd., Carl Zeiss (Shanghai) Management Co., Ltd.

Company, Pan Asia Automotive Technology Center Co., Ltd.

1 Scope

This standard specifies the terms and definitions of the maximum entity requirements, minimum entity requirements and reversible requirements, basic provisions, pattern representation methods and

Application example. These requirements apply only to dimension elements.

This standard applies to situations where workpiece dimensions and geometric tolerances are related to each other to meet their specific functions, such as meeting part assembly (most

Large entity requirements), minimum wall thickness (minimum entity requirements), but maximum entity requirements and minimum entity requirements also apply to other functional requirements.

Considering the correlation between dimensions and geometrical elements, when using the maximum entity requirement, minimum entity requirement or reversible requirement,

The principle of independence as defined in GB/T 4249 no longer applies.

2 Normative references

The following documents are indispensable for the application of this document. For dated references, only dated versions apply to this article.

Pieces. For undated references, the latest edition (including all amendments) applies to this document.

GB/T 1182-2018 Geometrical Product Specifications (GPS) Geometric tolerance shape, orientation, position and runout tolerance

(ISO 1101..2017, IDT)

GB/T 18780.2-2003 Technical specification for geometrical quantities (GPS) - Geometrical elements - Part 2. Description of cylindrical and conical surfaces

Take the center line, the extraction center plane of the parallel plane, and extract the local dimensions of the features (ISO 14660-2.1999, IDT)

ISO 5459.2011 Geometrical Product Specifications (GPS) Geometric Tolerance Benchmarks and Benchmark Systems [Geometricalproduct

Specifications(GPS)-Geometricaltolerancing-Datumsanddatumsystems]

ISO 14405-1.2010 Geometrical Product Specifications (GPS) Geometrical tolerances Part 1. Linear dimensions [Geometrical

Productspecifications(GPS)-Dimensionaltolerancing-Part 1.Linearsizes]

ISO 17450-1.2011 Geometrical Product Specifications (GPS) Geometrical tolerances Part 1. Geometric specification and validated models

[Geometricalproductspecifications(GPS)-Generalconcepts-Part 1.Modelforgeometricalspecifi-

Cationandverification]

3 Terms and definitions

GB/T 18780.2-2003, ISO 5459.2011, ISO 14405-1.2010, ISO 17450-1.2011 and the following terms

And definitions apply to this document.

3.1

Component integralfeature

A geometric element that belongs to the actual surface of the workpiece or to the surface model.

Note 1. The constituent elements define the features themselves, such as the surface of the workpiece.

Note 2. Quoted from ISO 17450-1.2011, definition 3.3.5.

3.2

Size element featureofsize

Linear size element featureoflinearsize

A geometric element with one or more essential features, only one of its essential characteristics can be used as a variable parameter, and the rest is "single

Part of the parameter family and adhere to the single constraint attribute of this parameter.

Note 1. Quoted from ISO 17450-1.2011, definition 3.3.1.5.1. For the "single parameter family" and "single constraint attribute", see also ISO 22432.2011,

Meaning 3.2.5.1.1.1 and 3.2.5.1.1.2.

Example 1. A single cylindrical hole or axis is a linear dimension element whose linear dimension is its diameter.

Example 2. Two relatively parallel flat surfaces are linear sized features whose linear dimension is the distance between the two parallel planes.

3.3

Export feature derivedfeature

The geometric elements that do not actually exist on the actual surface of the workpiece are not the nominal components.

Note 1. The derived features can be obtained from the nominal, fitted or extracted features. Can be called a nominal derived feature, a fitted derived feature, or an extraction guide

Out of the elements.

Note 2. The types of derived features include the center point, centerline, and center plane defined from one or more components.

Note 3. Quoted from ISO 17450-1.2011, definition 3.3.6.

Example 1. The centerline of a cylinder is the derived feature taken from the component of the cylindrical surface. The axis of the nominal cylinder is the nominal derived element.

Example 2. The center plane of two relatively parallel flat surfaces is the derived element obtained from the two parallel flat surfaces, which can constitute a constituent element. These two

The center plane of a relatively parallel plane is a nominal derived element.

3.4

Maximum entity state maximummaterialcondition

MMC

When the local dimension of the extracted component of the dimension element is at the limit size and has the largest material (the largest entity)

State, such as the smallest diameter of the hole and the maximum diameter of the shaft.

Note 1. In this standard, the term maximum entity state (MMC) is used to indicate that it needs attention at the ideal or nominal factor level (see ISO 17450-1.2011).

The required limit (upper or lower limit).

Note 2. The default mode or a special definition of several extracted feature sizes (see ISO 14405-1.2010) can be used to define the maximum entity state (MMC).

The size of the extracted features.

Note 3. As defined in this standard, the Maximum Entity State (MMC) can be used explicitly with any definition of the extracted feature size.

3.5

Maximum physical size maximummaterialsize

MMS

Determines the size of the feature's largest entity state.

Note 1. One of the default definitions or one of the specific definitions of several extracted feature sizes (see ISO 14405-1.2010 and GB/T 18780.2-2003)

Maximum physical size (MMS).

Note 2. In this standard, the maximum physical size (MMS) is a given value, so it is not necessary to specifically define the extraction size to explicitly use the most

Large physical size (MMS).

Note 3. See Appendix A.

3.6

Minimum entity state leastmaterialcondition

LMC

Assume that the local size of the extracted component is at the limit size and has the least amount of material (the smallest entity), for example

Such as the maximum diameter of the hole and the minimum diameter of the shaft.

Note 1. In this standard, the term minimum entity state (LMC) is used to indicate that at the ideal or nominal factor level (see ISO 17450-1.2011), attention needs to be paid

The limit (upper or lower limit) sought.

Note 2. The default mode or a special definition of several extracted feature sizes (see ISO 14405-1.2010) can be used to define the minimum entity state (LMC).

The size of the extracted features.

Note 3. As defined in this standard, the Minimum Entity Status (LMC) can be used explicitly in conjunction with the definition of any extracted feature size.

3.7

Minimum physical size leastmaterialsize

LMS

Determines the size of the feature's minimum entity state.

Note 1. One of the default definitions or one of the specific definitions of several extracted feature sizes (see ISO 14405-1.2010 and GB/T 18780.2-2003)

The minimum physical size (LMS).

Note 2. In this standard, the minimum physical size (LMS) is a given value, so it is not necessary to specifically define the extraction size to explicitly use the most

Small physical size (LMS).

Note 3. See Appendix A.

3.8

Maximum entity effective size maximummaterialvirtualsize

MMVS

The maximum physical dimension (MMS) of the dimension feature and the geometric tolerance (shape, orientation, or position) of its derived features

size.

Note 1. The Maximum Entity Effective Size (MMVS) is a size parameter that can be used as a value associated with the Maximum Entity Effectiveness (MMVC).

Note 2. For outer dimension elements, MMVS is the sum of MMS and geometric tolerances, and for inner dimension features, is the difference between MMS and geometric tolerances.

Note 3. MMVS, lMMVS, e of the outer dimension element are given by formula (1).

lMMVS,e=lMMS delta (1)

The MMVS, lMMVS, i of the inner dimension element is given by equation (2).

lMMVS, i=lMMS-delta (2)

In the formula.

lMMS---Maximum physical size;

delta --- geometric tolerance.

3.9

Maximum entity effect state maximummaterialvirtualcondition

MMVC

The state at which the feature is fitted to its largest physical effective size (MMVS).

Note 1. The Maximum Entity Effectiveness (MMVC) is the ideal shape state of the feature.

Note 2. When the geometric tolerance is the direction tolerance (see Figure A.3), the maximum entity effective state (MMVC) is affected by the direction of the fitting element (according to GB/T 1182-

Constrained by.2018 and ISO 5459.2011). When the geometry specification is a position specification (see Figure A.4), the maximum entity effectiveness state (MMVC) is fitted to

The position of the prime (according to GB/T 1182-2018 and ISO 5459.2011).

Note 3. When the geometric tolerance is the direction tolerance (see Figure A.3), the maximum entity effective state (MMVC) is affected by the direction of the fitting element (according to GB/T 1182-

Constrained by.2018 and ISO 5459.2011). When the geometry specification is a position specification (see Figure A.4), the maximum entity effectiveness state (MMVC) is fitted to

The position of the prime (according to GB/T 1182-2018 and ISO 5459.2011).

Note 4. See Figure A.1~Figure A.4, Figure A.6, Figure A.7 and Figure A.10~Figure A.13.

3.10

Minimum entity effective size leastmaterialvirtualsize

LMVS

The combination of the smallest physical dimension (LMS) of the dimension feature and the geometric tolerance (shape, direction, or position) of its derived feature

size.

Note 1. The Minimum Entity Effective Size (LMVS) is a size parameter that can be used as a value associated with the Minimum Entity Effectiveness (LMVC).

Note 2. For outer dimension elements, LMVS is the difference between LMS and geometric tolerances, and for inner dimension features, it is the sum of LMS and geometric tolerances.

Note 3. LMVS, lLMVS, e of the outer dimension element are given by equation (3).

lLMVS, e=lLMS-delta (3)

The LMVS, lLMVS,i of the inner dimension element is given by equation (4).

lLMVS, i=lLMS delta (4)

In the formula.

lLMS---minimum physical size;

delta --- geometric tolerance.

3.11

Minimum entity effect state leastmaterialvirtualcondition

LMVC

The state at which the feature is fitted to its smallest entity effective size (LMVS).

Note 1. The minimum entity effect state (LMVC) is the ideal shape state of the feature.

Note 2. When the geometric tolerance is the direction specification, the minimum entity effectiveness state (LMVC) is affected by the direction of the fitting element (according to GB/T 1182-2018 and

Constrained by ISO 5459.2011). When the geometric tolerance is the position specification, the minimum entity effective state (LMVC) is affected by the position of the fitted feature (based on

Constrained by GB/T 1182-2018 and ISO 5459.2011) (see Figure A.5).

Note 3. See Figure A.5, Figure A.8 and Figure A.9.

3.12

Maximum entity requires maximummaterialrequirement

MMR

Non-ideal elements of a dimension element must not violate one of the size factor requirements of its Maximum Physical Effectiveness (MMVC), ie, the size

A non-ideal element of a prime must not exceed one of the size factor requirements of its largest physical effectiveness boundary (MMVB).

The largest entity effective state (MMVC) or maximum entity effective boundary is the same type and ideal shape as the measured dimension element

The limit state of the geometric element, the size of which is MMVS.

Note 1. The maximum physical requirement (MMR) can be used to control the assembly of the workpiece.

Note 2. See also 4.2.

3.13

Minimum entity requires leastmaterialrequirement

LMR

Non-ideal elements of a dimension element must not violate one of the size factor requirements of its Minimum Entity Effectiveness (LMVC), ie, the size

The non-ideal element of the prime must not exceed one of the size factor requirements of its smallest physical effect boundary (LMVB).

Note 1. The minimum physical requirement (LMR) used in pairs can be used to control the minimum wall thickness, for example, the most between two symmetrical or coaxially arranged elements of the same size.

Small wall thickness.

Note 2. See also 4.3.

3.14

Reversible requirement reciprocityrequirement

RPR

Additional requirements for maximum entity requirements (MMR) or minimum entity requirements (LMR), indicating that dimensional tolerances can be small in actual geometric errors

Correspondingly increases within the difference between the geometric tolerances.

4 Maximum Entity Requirements (MMR) and Minimum Entity Requirements (LMR)

3 Figure A.4, Figure A.6, Figure A.7, Figure A.10 and Figure A.11).

Note 2. The use of containment requirements (formerly known as the Taylor principle) often leads to excessive constraints on feature functionality (assemblability). Use this constraint and ruler

The inch definition reduces the technical and economic benefits of the maximum entity requirement (MMR).

Note 3. When the geometric tolerance is a shape tolerance, the label 0 has the same meaning.

d) Rule D The maximum of the measured element when the geometric specification is relative to the direction or position of the (first) reference or reference system

The entity effectiveness status (MMVC) should be relative to the baseline or benchmark system, according to GB/T 1182-2018 and ISO 5459.

2011, in the correct direction or position of the theory (see 3.9 Note 2 and Figure A.3, Figure A.4, Figure A.6 and Figure A.7). In addition, when a few

When the measured elements are marked with the same tolerance, except for the possible constraints relative to the reference (see Figure A.1, Figure A.10, Figure A.11).

And Figure A.13), its maximum physical effectiveness state (MMVC) should be in the theoretical correct direction and position.

Note 4. When several measured elements are marked with the same tolerance, the maximum entity requirement (MMR) and other sums are not included in any other modifiers.

The same requirements for the CZ modifier have the same meaning. The SZ modifier should be used after the modifier to specify the application that needs to be separated.