Standard No.:	GB/T 20787-2023
English Name:	Reciprocating internal combustion engines—Measurement method for structure-borne noise
Chinese Name:	往复式内燃机 结构噪声测量方法
Chinese Classification:	J90    Piston type internal combustion engine and other power equipment in general
Professional Classification:	GB    National Standard
Issued by:	SAMR; SAC
Issued on:	2023-9-7
Implemented on:	2024-4-1
Status:	valid
Superseding:	GB/T 20787-2006 Classification system and test methods for nonmetallic gasket materials - Part 11: Standard practice for determining resistance of synthetic polymeric materials to fungi
Language:	English
File Format:	PDF
Word Count:	8500 words
Price(USD):	320.0
Delivery:	via email in 1 business day

GB/T 20787-2023 Reciprocating internal combustion engines - Measurement method for structure-borne noise 1 Scope This document describes the measurement methods for structure-borne noise emitted by reciprocating internal combustion engine. This document is applicable to reciprocating internal combustion engines defined in GB/T 21404 (hereinafter referred to as "engines" unless otherwise specified). 2 Normative references The following documents contain requirements which, through reference in this text, constitute provisions of this document. For dated references, only the edition cited applies. For undated references, the latest edition (including any amendments) applies. GB/T 1859.1 Reciprocating internal combustion engines - Measurement of sound power level using sound pressure - Part 1: Engineering method GB/T 1859.3 Reciprocating internal combustion engines - Measurement of sound power level using sound pressure - Part 3: Precision methods for hemi-anechoic rooms GB/T 6072.1 Reciprocating internal combustion engines - Performance - Part 1: Declarations of power fuel and lubricating oil consumptions and test methods - Additional requirements for engines for general use GB/T 6072.3 Reciprocating internal combustion engines - Performance - Part 3: Test measurements GB/T 13824 Mechanical vibration of rotating and reciprocating machinery - Requirements for instruments for measuring vibration severity GB/T 14777 Geometrical orientation and directions of movements 3 Terms and definitions For the purposes of this document, the terms and definitions given in GB/T 6072.1, GB/T 13824 and GB/T 14777 as well as the following apply. 3.1 structure-borne noise vibration propagating in a solid structure in the range of audible audio frequencies Note: The structure-borne noise in this document refers to the vibration propagating at the foot of the engine. 3.2 contact area supporting area on the engine side where the engine is in contact with surrounding components, especially vibration isolators (e.g. rubber) 3.3 translational velocity level

Foreword i Introduction iii 1 Scope 2 Normative references 3 Terms and definitions 4 Measurement environment 5 Measuring instruments 6 Installation and working conditions 7 Acceleration measurement 8 Calculation 9 Information to be recorded 10 Report Annex A (Normative) Other connections between engine and test environment Annex B (Normative) Height correction of sensor contact plane Annex C (Normative) Determination of test frequency range Annex D (Informative) Measurement records Bibliography