Green light for engine parts

In the avi­a­tion industry, even the most minor faults on the parts and com­po­nents can lead to serious fail­ures. In their pro­duc­tion process, engine and tur­bine com­po­nents pass through crack testing machines, as man­u­fac­tured by Rhode + Wagner Anla­genbau GmbH, in order to meet the high quality stan­dards.

The crack testing machine is around thirty metres long, approx­i­mately fif­teen metres wide and up to seven metres high. It con­sists of sev­eral work­spaces and process areas, with nine pro­cessing booths. In addi­tion there are var­ious infeeds, as well as robot-oper­ated spray areas to wet the com­po­nents. Crane and appli­ca­tion sys­tems are installed hor­i­zon­tally above the plant, trans­porting the tur­bine com­po­nents, which weigh up to 500 kilo­grammes and have up to one and a half metre diam­e­ters, from sta­tion to sta­tion.

Step by step through the crack testing machine at MTU Aero Engines

1. In the first booth, a robot sprays the com­po­nents with a flu­o­res­cent pen­e­trant.
2. Then they are lifted into the dark­ened booth on the trans­porter, where an indus­trial camera system scans the test objects from all sides. In this step, with the help of UV light, the plant oper­a­tors check the com­plete wet­ting of the com­po­nents.
3. In the booths that follow there are var­ious rinsing, drying and quality eval­u­a­tion processes, in which even the finest hair­line cracks are vis­ible under UV light.
4. At the end of the test line, the com­po­nents are pro­vided with detailed test doc­u­men­ta­tion. Only those engine parts that meet the required cri­teria one hun­dred per cent make it to final assembly.

Focus on operator and machinery safety

The out­line con­cept for this crack testing machine was already there at the end of 2018. In detail its task was to safe­guard all infeed and access areas, so that any haz­ards for oper­ating and main­te­nance employees were excluded. Above all, an intel­li­gent solu­tion was to be found, which would assign per­son­alised, task-spe­cific oper­ating mode and access per­mis­sions to the respec­tive oper­a­tors.

“When Pilz intro­duced us to PIT­mode fusion, it was imme­di­ately clear to us that this mod­ular system was ideal for meeting all of the customer’s Safety and Indus­trial Secu­rity spec­i­fi­ca­tions, as well as ful­filling our con­cepts of an effi­cient, user-friendly plant con­cept.”

Holger Wagner, Man­aging Director of Rhode + Wagner

Operating mode selection and access permission system PITmode fusion: Safely control who can do what

Not every employee who has access to the machine needs and should be per­mitted to have all the oper­ating, inter­ven­tion and change options avail­able on the exten­sive plant. An oper­ator has dif­ferent tasks and per­mis­sions to a machine setter or ser­vice per­sonnel. With PIT­mode fusion you can com­pletely set up a com­plex, safe per­mis­sion man­age­ment system. Employees are given their task-based, per­son­alised RFID transponder, con­taining the appro­pri­ately adapted access per­mis­sion and machine enable. When an oper­ator inserts their key and selects the required oper­ating mode, the system com­pares the per­mis­sion on the key with the requested oper­ating mode. When enabled, the mul­ti­colour LED ring on the PITreader gives the “green light”. That way the oper­ator can only carry out the tasks they are intended to per­form. Any other access or inter­ven­tion is denied and thus manip­u­la­tion pro­tec­tion is guar­an­teed. That min­imises the risks and sig­nif­i­cantly increases a plant’s Safety and Indus­trial Secu­rity stan­dard.

Plant oper­a­tors can define up to five safe oper­ating modes and assign the cor­re­sponding rights to autho­rised per­sonnel: auto­matic mode, manual inter­ven­tion under restricted con­di­tions or ser­vice mode, for example.

Safety sensors as safety allies

The Pilz PSENslock, the safety gate system with process guarding, and PSEN­m­lock, the safety gate system with mechan­ical guard locking, are also inte­gral com­po­nents of the safety con­cept. While PSENslock offers safe posi­tion mon­i­toring with process guard locking in a single system, PSEN­m­lock can be used up to the highest cat­e­gory thanks to safe inter­locking and safe guard locking for the pro­tec­tion of per­sonnel and processes. On the crack testing machine, PSENslock is used to safe­guard posi­tion: as mate­rial is fed in, the switch checks that the nec­es­sary holding force of the elec­tro­magnet has been estab­lished and there­fore the loading car­riage is standing firm. The safety gate system PSEN­m­lock ensures safe mon­i­toring and safe guard locking on four­teen safety gates: it guar­an­tees safe mechan­ical guard locking, pro­tecting per­sonnel in the imme­diate envi­ron­ment.

Rhode + Wagner values the flex­ible, easily adapt­able approach of PIT­mode fusion: “It means we can guar­antee to our cus­tomers that plants have the very latest safety tech­nology. At the same time they ben­efit from higher avail­ability of their machinery”, says Holger Wagner. For this reason, all future plants that need to switch between dif­ferent con­trol sequences and oper­ating modes are to be equipped with the inno­v­a­tive oper­ating selec­tion and access per­mis­sion system from Pilz.