GB/T 41108.3-2021Safety of machinery—Safety requirements for interlocking devices—Part 3: Trapped key interlocking devices and systems (English PDF)

Foreword

This document is in accordance with the provisions of GB/T 1.1-2020 "Guidelines for Standardization Work Part 1: Structure and Drafting Rules of Standardization Documents" drafted.

This document is part 3 of GB/T 41108 "Safety Requirements for Mechanical Safety Interlocks". GB/T 41108 has been released The following parts.

--- Part 1: Direct disconnection of position switches;

--- Part 2: Interlocks with guard locking;

--- Part 3: Interlocking devices and systems for retaining keys.

Introduction

The safety standard system in the field of machinery consists of the following types of standards.

--- Type A standard (basic safety standard), giving the basic concepts, design principles and general characteristics applicable to all machinery;

--- Class B standard (general safety standard), involving a safety feature in machinery or a class of safety devices with a wide range of use.

- Class B1, standard for safety features (such as safety distance, surface temperature, noise);

- Class B2, safety devices (such as two-hand operating devices, interlocking devices, pressure-sensitive devices, protective devices) standards.

--- Class C standard (machine product safety standard), a standard that specifies detailed safety requirements for a specific machine or a group of machines.

According to GB/T 15706-2012, this document belongs to category B2 standard.

This document is particularly relevant to the following stakeholders related to machinery safety.

--- machine manufacturer;

--- Health and Safety Agency. Other stakeholders affected by the level of machinery safety are.

--- machine users;

--- the owner of the machine;

--- service providers;

--- Consumers (for machinery intended for use by consumers).

All of the above-mentioned stakeholders may have participated in the drafting of this document.

In addition, this document is intended for standardization bodies drafting Type C standards.

The requirements specified in this document may be supplemented or modified by Type C standards.

For machines that are within the scope of the C-type standard and have been designed and manufactured in accordance with the C-type standard, the requirements in the C-type standard are preferred.

Interlocking device is a type of protective device commonly used in mechanical safety protection, mainly used to prevent dangerous machine functions under specific conditions (usually Refers to operation as long as the guard is not closed) to avoid personal injury.

GB/T 41108 consists of three parts.

--- Part 1: Direct disconnection of the position switch. Direct disconnection of the position switch is an interlocking device widely used at home and abroad.

Products, such as sliding safety doors for CNC machine tools, disable dangerous machine functions through position switches when the door is opened.

--- Part 2: Interlocks with guard locking. The moving parts of mechanical equipment cannot stop in a short time due to their inertia, It is necessary to add the safety function of protective locking to the interlocking device, which is usually realized by electromagnetic force to ensure the movement of the machine.

Protective devices such as safety doors controlled by interlocking devices can only be opened after the components are stopped.

--- Part 3: Interlocking devices and systems for retaining keys. The trapped key interlock device is a new type of interlock device that has appeared in recent years.

Usually used in large equipment or production lines, especially suitable for preventing other personnel from accidentally starting the machine during equipment maintenance and overhaul. danger to life.

A trapped key interlock is a safety device that performs a function by trapping or releasing a key. In practical application, In order to realize one or more safety functions, at least two or more trapped key interlocking devices are required to be grouped in a certain logical sequence. Synthetic trapped key interlock system.

1 Scope

This document specifies requirements and usage information for trapped key interlocks and systems.

This document applies to safety-related trapped key interlocks and systems.

2 Normative references

The contents of the following documents constitute essential provisions of this document through normative references in the text. Among them, dated citations documents, only the version corresponding to that date applies to this document; for undated references, the latest edition (including all amendments) applies to this document.

GB/T 14048.1-2012 Low-voltage switchgear and control equipment - Part 1: General

GB/T 14048.3-2017 Low-voltage switchgear and controlgear-Part 3: Switches, isolators, isolating switches and fuse sets Combiner

GB/T 14048.5-2017 Low-voltage switchgear and control equipment-Part 5-1: Control circuit electrical appliances and switching elements electromechanical control circuit electrical appliances

GB/T 15706-2012 General Principles of Mechanical Safety Design Risk Assessment and Risk Reduction

GB/T 16855.1-2018 Safety-related parts of machinery safety control systems - Part 1: General rules for design

GB/T 16855.2-2015 Safety-related components of machinery safety control systems - Part 2: Confirmation

GB/T 18831-2017 Design and selection principles of interlocking devices related to mechanical safety and protective devices

GB/T 41108.1 Safety requirements for mechanical safety interlocks - Part 1: Direct disconnection of position switches

GB/T 41108.2-2021 Safety requirements for mechanical safety interlocks - Part 2: Interlocks with guard locking

3 Terms and Definitions

The terms and definitions defined in GB/T 15706-2012, GB/T 18831-2017 and GB/T 41108.1 and the following terms and definitions apply to this document.