Practical application of EN ISO 13849-1 for machine tools - Eberhard Beck

“Safety related control systemsfor machinery“

ST/Beck -1-09.09.10

Brussels, 9th September 2010

“Practical application of EN ISO 13849-1

for machine tools”

INDEX Werke GmbH & Co. KG Hahn & Tessky

Eberhard Beck Head of control techniques INDEX-Werke

EU-Symposium

“Safety related control systems for machinery”


ST/Beck -2-09.09.10

0 General Introduction The company of INDEX

1 Practical application of Workpiece clamping device

EN 13849 to Machine Tool as EN 13849 safety function

Requirements according

EN 12415 // EN ISO 23125

Requirements applying

EN ISO 13849 risk analysis

Conclusion

2 Further experiences out of Translation problems “How

the EN ISO 13849 application to get EN ISO 13849 diagrams”?

Multiple safety functions for

EN ISO 13849 requirements

3 Summary out of the EN ISO 13849

application

Overview

Structure for the Presentation


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1914 19541914 1970

First NC machineFounded by

Hermann Hahn

Begin with the production

of turret screw machines

20.000 INDEX machines sold

1997Merger with

TRAUB-Drehmaschinen

GmbH

1992

Introduction of the modular

building block system with

the RatioLine and VerticalLine

1985First CNC-controlled multi

spindle machine with

hollow shaft motor

The Eugen und Irmgard

Hahn foundation becomes

shareholder with 85% after

the death of Eugen Hahn

1990

History of INDEX-WerkeFrom the beginning …


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Introduction of flexible

high performance

turn mill centers

2000 2002

Integration of various

technologies in serial

production

First provider of a

Virtual Machine

for the PC

2005 2009

Introduction of 5-axis-

turn mill centers of the

newest generation

History of INDEX-Werke… to the past 10 years


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Medical Industry

Fittings / Fluidics

Electronics

Automotive

Optics / Precision Mechanics

Air- / Spacecraft Technology

Customer segments and industries… typical cycle times and part numbers

Cycle times

from ≥ 1 second

up to > 2,5 hours

typical 30 to 240 s

Number of parts

from single part

production up to

> 10 Mio parts/year


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Locations and subsidiaries Agents

Turnover (2008) 510 Mio €

Number of Employees (2008) ca. 1950

Number of Machines (2008) ca. 1200

Export rate ca. 40 %

INDEX-Werke GmbH & Co. KG… in figures, locations and subsidiaries


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Typical parts machined by INDEX machine tools(examples for bar machining)


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Working zone of INDEX machines(example)


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Machining inside INDEX machines(video example)


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EN 12415 // EN ISO 23125



Conclusion






application

Overview



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Workpiece clamping device as safety function(based on EN ISO 23125 + EN ISO 13849 requirements )


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P

Monitoring pres-sure cylinder A

Monitoring hydraulic pressure

Pressure cylinder A

Pressure cylinder B

Cylinder stop

Enabling cylinder movement

Main spindle with chuck

Sensor for jaw position

Clamping/ unclamping valves

A

B

nonreturn valves

Hydraulic power supply

Sensors for clamping pressure

Hydraulic pipes

PLC control + PLC software

24V/I

24V/O

24V/O

24V/O

24V/O

Monitoring pres-sure cylinder B

Monitoring jaw position

Workpiece clamping safety function“state of the art”

safety equipment (sensors) are monitored by PLC


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EN 12415 // EN ISO 23125



Conclusion






application

Overview



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EN 12415

Cat. “1”

EN954-1


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Meldepflichtige Unfälle an Werkzeugmaschinen

20000

25000

30000

35000

40000

45000

50000

1992 1994 1996 1998 2000 2002 2004 2006 2008

Jahr

An

zah

l

Maschinenrichtlinie (und Typ C Normen)

Improvement of accidents

in Germany since 1993

“C-Standards” for machine tools

in relation to “accidents at machine tools”


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EN 23125

PL “b”

EN13849


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EN ISO 23125 workpiece clamping function“state of the art”

EN ISO 13849 safety calculation

safety function “workpiece clamping”

evaluation according to DIN EN ISO 13849:2007

Institute of employers„ liability

insurance association (BGIA)


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VDW-Project

Functional safety for machine tools

More than 100 experts: 60 designers, 30 suppliers, 16 Safety Experts, …have

- 20 typical safety functions for machine tools defined

- 10 safety functions have been calculated in more than 1,5 years

- over 40 meetings have been hold and more than 200.000 € have been spent


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Definition of safety functionsworkpiece clamping device

“state of the art”

Standstill of the spindle

Clamping of the workpiece

Run up of the spindle

Diagnosis clamping state and door

Diagnosis clamping pressure and position

Machining of the workpiece

Run down of the spindle

Opening of the clamping device

Clamping

at

Clamping

at


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Definition of safety functionsworkpiece clamping device


safely limited speed

workpiece clamping

without speed (= 0)

Monitoring work-

piece clamping with

speed (> 0)

safety function

b

b

d

SF2

SF3


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SISTEMA

PL “b”

EN23125

SISTEMA

PL “c”

EN23125

EN ISO 23125

EN ISO 23125

Safety block diagram + SISTEMA “PL result”workpiece clamping safety function



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EN 12415 // EN ISO 23125



Conclusion






application

Overview



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Figure A.1 – risk graph to define the performance level for each safety function

Selection of performance levels, a - e

PLrequired

PL “d”

EN13849

?

EN ISO 13849 result / requirementsworkpiece clamping safety function

“new safety status?”


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EN ISO 13849 requirements Comparison workpiece clamping safety functionagainst remaining residual risks in practice

In spite of PLr (EN 13849) “d” – in practice there is no

significant increasing of real safety at the machine

Because the following remaining residual risks in practice

also have to be considered:

- The risk of a collision between moving tools, tool carriers

and the workpiece or the workpiece clamping device

- The risk for a lack of clamping force based on a bad

maintenance condition of the clamping devices

- The risk of an insufficient hydraulic clamping

pressure in relation to the machining operations

- The risk for a not suitable maximum spindle speedfor the clamping device and / or the workpiece


ST/Beck -26-09.09.10

Without having PLr based on experts experience out of

“Type C” standard, the found high end PLr” of EN 13849

can be misleading

EN ISO 13849 requirements Evaluation EN ISO 13849 requirements against experts experience in practice

- The safety status only can be seemingly increased.

In practice, seldom a real safety improvement at the

real machine can be achieved

- The “high end PLr” requires high efforts in realization.

Remaining risks outside the scope of the safety related

control system could stay unnoticed

- The “high end PLr” often is very difficult to realize.

This can cause to further problems in operation of the machine and lead to the manipulation of safety devices


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EN 12415 // EN ISO 23125



Conclusion






application

Overview



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The big differences between new EN ISO 13849 PLr

safety requirements and EN 954-1 safety categories

based on “type C” safety standards leads to great

trouble and uncertainty among the applicants of the

EN ISO 13849 standard

Conclusion:

Conclusion


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Overview






EN 12415 // EN ISO 23125



Conclusion






application


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Technical

layout (Mechanic,

Hydraulik. Hard-/

Software)

Logical

structure of safety

functions according

EN 954-1

Difficulties in application of EN ISO 13849

Safety function based on EN 954-1 has been a

1:1 relationship

Translation from

Technical layout

to

Logical structures of

EN 954-1 categories

“relative easy”

for technicians


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From the point of view of a machine tool (MT) builder …

How to translate safety function into EN 13849?

Technical

layout (Mechanic,

Hydraulik. Hard-/

Software)

Structure

of EN 13849

functions safety

block-diagrams

How to translate from

Technical layout

to

EN 13489 safety

block-diagrams?

?


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EN 12415 // EN ISO 23125



Conclusion






application

Overview



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Safety functions based on EN 13849 have a

1:n relationship

SF2: Werkstückspannen im Stillstand (Anlauf verhindern bei falschem Spannzustand)

S1

Spannwegkontrolle

K1 + T1

NCU S840D

+ SINAMICS

Blatt KR5701.51371 (Seite 515)

MK2

Standard SPS Blatt

KR5701.51371 (Seite 515)

SF3: Werkstückspannen unter Drehzahl (lösen verhindern)

K1 + T1

NCU S840D

+ SINAMICS


K2

Standard SPS Blatt

KR5701.51371 (Seite 515)

G1

Motorgeber Werkstückspindel

Spannmechanik

SF4: Spindel stillsetzen bei Druckverlust

S2

Drucküberwachung

MK2

Standard SPS Blatt

KR5701.51371 (Seite 515)

K1 + T1

NCU S840D

+ SINAMICS


Spannmechanik


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SF5: Druckänderung verhindern unter Drehzahl

K1 + T1

NCU S840D

+ SINAMICS


K2

Standard SPS Blatt

KR5701.51371 (Seite 515)

G1

Motorgeber Werkstückspindel

Gesteuertes Druckventil

SF2 und SF4 sind bei BGIA Betrachtung nicht abgebildet. Kein Induktivgeber in SF2 bei BGIA.

PLr c weil bei Fräsmaschinen d zum Einsatz kommt.

K1 + T1

Sicherheitssteuerung

Spannungsversorgung für Ventilsteuerung

wird über PROFISAFE geschaltet


Safety functions based on EN 13849 have a

1:n relationship


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EN 12415 // EN ISO 23125



Conclusion






application

Overview



ST/Beck -36-09.09.10

Summary

- out of the EN ISO 13849 application

1. For EN ISO 13849 application there is no description or guideline how

to “translate” technical structures into EN ISO 13849 based safety

block structures for EN ISO 13849 evaluation and calculation.

2. EN ISO 13849 beginners are not able to understand and apply EN

ISO13849 standard without (foreign) introduction and practical

training.

3. The need to specify and define multiple EN ISO 13849 safety functions

for the evaluation of one physical technical safety structure requires

great efforts which SME seldom are able to spend.

4. Different level of safety requirements inside EN 954-1 based C-

standards in comparison to EN ISO 13849 based risk analysis lead

to great uncertainty and trouble among EN ISO 13849 applicants.

5. The “high end PLr” of EN ISO 13849 based risk analysis often is much

beyond the technical “state of the art”. It's realization is difficult, very

expensive and causes most further problems in machine operation.


ST/Beck -37-09.09.10

Recommendation- out of the experience of the EN ISO 13849 application

1. There should be a written guideline how to “translate”

technical structures into EN ISO 13849 based safety block

structures in general

2. There should also be a guideline how to apply EN ISO

13849 calculation for EN ISO 13849 based safety block

structures in general

3. The EN ISO 13849-1 and ISO 14121 risk assessment should

be synchronized and harmonized!

4. The safety requirements in C-Standards – based on experts

experience – have to be the leading value in EN ISO 13849

“translation” of these standards!


ST/Beck -38-09.09.10

Thank you for your attention!

Questions?

Eberhard Beck Head of control techniques INDEX-Werke

EU-Symposium

“Safety related control systems for machinery”

Practical application of EN ISO 13849-1 for machine tools - Eberhard Beck

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Transcript of Practical application of EN ISO 13849-1 for machine tools - Eberhard Beck