brill+adloff | WITTE locking cylinder

Our developers help to make glove compartments more forgiving

A locking cylinder in the glove compartment has to put up with a lot in the course of its life. To ensure that it still functions reliably, our engineers have come up with quite a few ideas. And designed the entire process chain, including testing methods, for our customer Witte Automotive – thus enabling the extremely precise production of an extraordinarily delicate locking cylinder with six openings.

Customer WITTE Automotive

Industry Automotive industry

Services Process development
Manufacturing

Plastic POM-C

Skip to the section:

01 The challenge

02 Our solution

03 The result

The challenge

A delicate plastic part with 6 openings that can be reliably manufactured and function smoothly for years

For our customer Witte Automotive, we manufactured the housing of a locking cylinder for glove compartments. There are 6 strike plates in the locking cylinder. And for each strike plate, an opening has to be made in our small plastic part. That in itself is not a challenge for us. But with functional surfaces in each of these six channels, it becomes quite a challenge. Especially when we have to adhere to tolerances of a few hundredths – less than a human hair.

That was just challenging enough for us. Because we were able to play to our strengths here. We declared war on burrs and flakes in the channels. And with our interdisciplinary manufacturability assessment, we developed the entire process step by step, with which we can manufacture this delicate plastic part reliably for years to come. And at the same time ensure that the locking cylinder in the glove compartment does not fail, but is much more forgiving.

Our solution

Comprehensive feasibility assessment and test methods

Not many plastic injection molders have the comprehensive expertise and holistic view required to develop industry-leading processes. But we are not many, we are brill+adloff. And we love mastering challenges that others don’t dare to tackle. Our process development for the WITTE locking cylinder focused on two things in particular: our comprehensive manufacturability assessment and our test methods.

Feasibility assessment & drawing

Our manufacturability assessment is really something special. This is because we work particularly closely with development, toolmaking, production and, if necessary, logistics on an interdisciplinary basis. And we take a very close look at every functional feature. This enables us to evaluate the manufacturability of a part holistically in each of its characteristics. And to make recommendations on how the article can be improved. For example, we made sure that we had sufficient draft angles for the smooth production of our lock cylinder, even though no draft angle was permitted between the 5th and 6th channel for functional reasons.

We have incorporated our findings from the manufacturability assessment directly into our drawing. And this shows how important our comprehensive manufacturability assessment is. We started with a development drawing and are now working with an index 19 drawing. So we have already made some adjustments to the drawing – and therefore also to the design of the locking cylinder. And in doing so, we have moved further and further in the direction of a reliable process.

Such interdisciplinary and comprehensive evaluations do not result in 08/15 drawings. The drawing of our locking cylinder, for example, contains a relatively large amount of text. This was necessary in order to take into account the many functional requirements with tight tolerances and to implement them optimally in the design. This allowed us to think about the necessary tests and test methods right from the start. And to design our solution for long-term process reliability.

Test methods

6 filigree channels. Each with a functional surface. And with tolerances in the hundredths range. This was not so easy for the channel diameter. Because burrs or flakes – i.e. tiny burr residues, also known as burr fluff – were not at all useful here. They would have caused the slides, which run against each other in a channel, to block under certain circumstances. And then the glove compartment could no longer be opened or closed.

Burrs and burr fluff should be avoided early on in the process. That is clear. And we gave it our all. By checking our tools every four hours and cleaning them if necessary. All we needed now was a test method that showed us whether that was enough. This was the only way we could be sure that there were no functional problems in any of the channels. And because we wanted to make this test as efficient as possible, it was not an option for us to install strikers and springs for testing purposes.

Instead, we measured the diameter of the ducts. Working closely with Witte, our first step was to precisely determine the function-critical points in each channel. We then developed our answer to the HOW: a measuring pin test. This involves dropping metal measuring pins through the channels of the locking cylinder. We adjusted the weight of the measuring pins to take into account the force of the springs that later move the strike plates in the locking cylinder. If the pins fall through the channels without any problems, the functional surfaces are OK. Challenge mastered.

As part of our quality agreement with Witte, we also monitor some of the special characteristics statistically. Because if a process is capable – and this is our process, which complies with the CpK value of 1.67 for the special characteristics measured – the channels only need to be randomly checked for burrs and flakes every 8 hours. This meant we always had an overview of the quality of our part. And we were as efficient as possible.

The brill+adloff project team supported us very competently from the start and the communication was great.

Purchasing Coordinator, WITTE Automotive GmbH
brill+adloff did an excellent job with both the APQP processing and the DFM analysis.

Suppliermanager, WITTE Automotive GmbH
The preparation for the VDA 6.3 audit was great and the communication from brill+adloff was always transparent and at eye level.

Auditor, WITTE Automotive GmbH

The result

A delicate plastic part. Reliable and without failures since 2011

Once we had worked out and agreed initial changes with Witte from our feasibility analysis in the initial phase, things really got going. And with the lessons learned from our manufacturability analysis and our test methods, we ensured that the delicate plastic locking cylinder was reliably manufactured within the tight tolerances and that all functional characteristics were adhered to.

And we’ve done pretty well. Because since the start in 2011, there has not been a single field or 0-kilometer failure of our locking cylinder. In other words, all our locking cylinders work perfectly – whether for one of the many millions of end customers or an OEM, such as Ford. No matter how much they have had to take since 2011. It couldn’t be better with such a delicate plastic part.

Here, too, we have made the impossible possible

John Deere hydraulic hose holder and clamp

Our solutions help to ensure that harvests can be harvested all over the world.

Learn more
Schell pressure flush cartridge

Our specialists make sure you feel good every time you go to the toilet.

Learn more

WITTE Locking cylinder