GB/T 19876-2012Safety of machinery -- Positioning of safeguards with respect to the approach speeds of parts of the human body (English PDF)

1 Scope 1

2 Normative references 1

3 Terms, Definitions, Symbols and Abbreviations 2

3.1 Terms and Definitions 2

3.2 Symbols and Abbreviations 3

4 Method 4

5 General formula for system-wide shutdown performance and minimum distance calculation 6

5.1 System-wide downtime performance 6

8 Two-hand controls17

9 Interlocking guards without guard locking 17

Appendix A (Informative Appendix) Calculation Example 19

Appendix B (Informative) Termination of Dangerous Machine Functions 26

Appendix C (Informative) Examples of Considering Indirect Access 27

Appendix D (Informative Appendix) Measurement and Calculation of System-wide Shutdown Performance 29

Appendix E (informative) Number of beams and their height above the datum 31

Reference 32

Mechanical safety related to the speed of approaching body parts Positioning of safety guards

1 Scope

This standard specifies the positioning of safety guards in relation to the approach speed of human body parts.

This standard specifies parameters based on the value of the approach speed of human body parts and provides means for actuation from detection zones or safety guards Method for determining the minimum distance to the danger zone.

Approach speed values (walking speed and upper extremity movement) in this standard have been verified by timed tests or practical experience. This standard gives Guidelines for calculating minimum distances for typical approaches. This standard does not consider other forms of approach, such as running, jumping or falling.

Note 1.Other forms of approach can lead to approach speeds higher or lower than the values specified in this standard.

Safety guards considered in this standard include.

a) Electro-sensitive protective equipment [see IEC 61496 (all parts)], including.

--- Light curtains and light grids (AOPDs);

--- Laser scanners (AOPDDRs) and 2D vision systems;

b) Pressure-sensitive protective devices (see GB/T 17454.1, GB/T 17454.2, GB/T 17454.3), especially pressure-sensitive pads;

c) Two-hand operating device (see GB/T 19671);

d) Interlocking guards without guard locking (see GB/T 18831).

This standard specifies the hazards arising from the detection zone, detection surface, detection line, detection point or entry point of an interlocking guard to the moving parts of the machine.

(e.g. crushing, shearing, entanglement) distance to the danger zone.

This standard applies to machinery defined in GB/T 15706.

This standard does not apply to protection against risks posed by hazards arising from flying solid or fluid materials, emissions, radiation or electricity.

Note 2.When determining the invasive distance "C" value in the formula, the anthropometric data between the 5th and 95th percentiles of people aged 14 and over were used.

Note 3.The data in this standard is based on industrial experience; if this standard is used for non-industrial purposes, it is the designer's responsibility to take this into account.

Note 4.This standard does not use data specifically for children. Until specific data on the child's approach speed are available, designers have the responsibility takes into account that the child may be detected sooner or the child may enter the danger zone before being detected.

This standard does not apply to safety guards (such as suspended hanging two-hand control).

The minimum distances derived in accordance with this standard do not apply to detection in areas already protected by guards or electro-sensitive protective equipment.

Safety guards in the absence of human presence.

2 Normative references the following documents are essential for the application of this document. For dated references, only the dated version applies to this article pieces. For undated references, the latest edition (including all amendments) applies to this document.

GB/T 15706-2012 General Principles of Mechanical Safety Design Risk Assessment and Risk Reduction (ISO 12100:2010, IDT) GB 23821-2009 Safety of machinery to prevent the upper and lower limbs from touching the safety distance of the danger zone (ISO 13857:2008, IDT) IEC 61496-1:2004 Safety of machinery electro-sensitive protective equipment - Part 1: General requirements and tests (Safetyofmachinery-Electro-sensitiveprotectiveequipment-Part 1: Generalrequirementsandtests)

3 Terms, Definitions, Symbols and Abbreviations

3.1 Terms and Definitions GB/T 15706 as well as the following terms and definitions apply to this document.

3.1.1

actuation

Physical actuation when a safety guard detects a human body or a body part.

3.1.2

overallsystemstoppingperformance Time interval between actuation of the sensing function and termination of the hazardous machine function.

Note. Adapted from IEC 61496-1:2004 3.1.3 detectioncapability Supplier-specified limits for sensing function parameters that cause actuation of protective devices.

[IEC/T S62046.2004, 3.1.2] 3.1.4 electro-sensitiveprotectiveequipment ESPE an integration of devices and/or components that, when working together, can act as protective tripping or presence sensing, consisting of at least.

--- an induction device;

--- control/monitoring devices;

---Output signal switch device.

[IEC 61496-1:2004, 3.5] Note. Electro-sensitive protective equipment refers only to non-contact sensing devices.

3.1.5

Indirect Approach

Approach when the shortest path to the danger zone is blocked by a mechanical obstacle.

NOTE. Access to the danger zone is only possible by bypassing obstacles.

3.1.6

circumventing the detection zone Pass above, below or to the side of the detection zone and enter the danger zone without the protection device being actuated.

3.1.7

terminationofthehazardousmachinefunction the condition attained when a hazard parameter is reduced to a level that does not cause bodily harm or damage to health.

Note. See Appendix B for examples.

3.1.8

detectionzone

Specifies the area of the test piece that can be detected by protective equipment.

Note 1.The detection area can also be a point, line or plane.

Note 2.Adapted from IEC 61496-1:2004, 3.4.

3.1.9

minimum distance

Calculated safety guards and hazards necessary to prevent persons or body parts from entering the danger zone until the machine reaches a safe state distance between danger zones.

Note. For different states or different approaches, the calculated minimum safety distance may be different. However, when selecting the position of the protective device, the Use the maximum of these minimum distances.

3.1.10

intrusiondistance

The distance that a body part (usually the hand) moves past the safety guard to the danger zone before the safety guard is actuated.

3.2 Symbols and Abbreviations

3.2.1 Symbols

3.2.2 Abbreviations

AOPD --- Active Photoelectric Protection Device AOPDDR---active photoelectric protection device (such as laser scanner) responding to diffuse reflection VBPD --- Vision Based Protection Device ESPE --- Electro-sensitive protective equipment 4 methods

Figure 1 shows a schematic diagram of the method for determining the correct position of the sensing or actuating device of a safety guard in accordance with this standard, as follows.

a) Identify hazards and assess risks (see GB/T 15706);

b) if a Class C standard is available for the machine, select a specified type of safety guard from the appropriate Class C standard, and use the distances specified in this standard;

Note 1.The C-type standard directly specifies the minimum distance or requires reference to this standard.

c) If there is no Class C standard, use the formula given in this standard to calculate the minimum distance of the selected safety guard;

Note 2.See GB/T 15706-2012, 6.3 and IEC/T S62046 for the selection of suitable safety guards.

d) If there is a possibility of bypassing (bypassing) the detection area, it is also necessary to use the formula in 6.5 for auxiliary calculation;

e) If combined safety guards are used, each type of safety guard and possible bypasses should be considered when calculating the minimum distance.

Capability;

f) Calculate the minimum distance for each possible route into the danger zone, and select the safest (maximum value) among them;

g) If possible, use this distance for the design of the machine. Otherwise, see step i);

h) Check whether there is a possibility of entering the danger zone without being detected after the safety guard is installed. If there is such a possibility If not, then it should be redesigned [step i)], otherwise go to step j);

i) Can the parameters be modified or other safety guards be used? If this is not possible, additional safety guards should be used;

j) Check that the determined position allows a person to remain undetectable between the protective device and the danger zone. In this case, the root Supplementary measures are provided based on additional risk assessments.

Note 3.Examples of supplementary measures. Manual reset switches located outside the danger zone or between the safety guard and the danger zone. manual reset switch position the selection makes it easy for the person operating it to check that there are no persons in the danger zone or between the safety guard and the danger zone. Manual reset See GB/T 16855.1-2008, 5.2.2 for functional requirements.

5 General formula for system-wide shutdown performance and minimum distance calculation

5.1 System-wide shutdown performance System-wide shutdown performance consists of at least two phases. The relationship between the two stages can be expressed by formula (1).

System-wide shutdown performance T is an essential characteristic for determining the location of protective devices. When estimating the value of T, any difference in the machine downtime (t2) all deviations should be considered (see Appendix D). When machine downtime becomes longer in its life cycle, technical or management measures should be adopted to ensure accurate full System downtime performance. For example, these measures include.

--- the braking performance of the control device;

--- Inspection, the nature and frequency of inspection should be specified in the user manual.

NOTE. Some additional factors may also need to be considered, such as.

a) Integrity of the protection function (fail safe) (see GB/T 16855.1, GB/T 16855.2 and IEC 62061);

b) shutdown performance monitoring (see IEC/T S62046, etc.);

c) In cases where this standard cannot be applied due to insufficient shutdown performance, such as.

1) The machine cannot be stopped in one cycle;

2) Downtime performance is unpredictable.

In order to obtain accurate and appropriate values, the measurement of system shutdown performance needs to be carefully considered. Appendix D provides guidelines for ensuring proper results Step by step guide.

5.2 Minimum distance the minimum distance to the hazardous area shall be calculated using general formula (2).

For specific types and specific configurations of protective devices, Chapters 6 to 9 show how to use this formula to calculate the minimum distance. count See Appendix A for an example of the calculation.

6 Minimum distance calculation of electro-sensitive protective equipment using active photoelectric protection system

6.1 Overview

6.1.1 This chapter specifies the requirements when the approach direction of the human body or parts of the human body is in the following two main situations.

a) perpendicular to (at right angles or normal to) the detection zone (see 6.2);

b) parallel to the detection zone (see 6.3).

It also specifies requirements for the following situations.

--- Need to consider the case of approaching from a certain angle (between vertical and parallel directions) (see 6.4);

--- Have to consider situations where electro-sensitive protective equipment may be bypassed (see 6.5);

--- The path from the detection area to the danger area is blocked by obstacles (indirect approach) (see 6.6).

Note 1.The above situations may also occur at the same time.

When the minimum distance cannot detect a person staying between the hazard zones of the detection area, presence sensing devices or other means should be provided to prevent this.

Note 2.This standard does not provide measures to prevent reaching the danger zone by climbing.

6.1.2 The configuration and positioning of safety guards should be able to prevent entering the danger zone without being discovered.

6.1.3 If necessary, additional safety guards should be provided to prevent bypassing the detection area of the safety guards (see Figure 9).

6.1.4 If a laser scanner (AOPDDR) or vision-based protection device (VBPD) with two-dimensional protection zone is used, the Calculate the minimum distance in the near direction according to 6.2, 6.3 or 6.4.

6.2 The detection area is perpendicular to the approach direction

6.2.1 Overview

Figure 3 shows three examples where the detection zone is perpendicular to the approach direction.