Noisy Latches No More

BIRMINGHAM, MI – The relentless pursuit to limit or lessen noise in vehicle interiors extends to items you might think would be overlooked, including the unassuming door latch.

While its noise is heard briefly when entering and exiting the vehicle, automakers nevertheless are taking issue with an overly audible latch.

“As vehicle cabins got quieter, people started hearing more things, good or bad,” Mike Hietbrink, general manager-Kiekert USA, tells media here at the 2016 Tech Crawl event featuring suppliers.

Hietbrink later tells WardsAuto the majority of the 60 brands Kiekert supplies, armed with data from consumer surveys, are asking it to manage latch noise to create a perception of luxury in their vehicles.

There’s no way to create a noiseless latch, but noise can be dampened to create the desired low-frequency sound most OEMs favor, says Hector Verde, director-product development of the Americas for Kiekert USA.

“A lot of customers are looking for a low-frequency sound – that’s what everybody prefers, not a high (-pitched) metallic sound,” Verde tells WardsAuto. Low-frequency sound is associated with luxury thanks to the plentiful door seals found on most luxury models.

“Maybe (certain cars) really don’t have them, but the perception would be low-frequency sound, that you’re sealing the car very nice,” Verde says.

The three areas of noise in a normal latch include opening noise, actuator noise during locking and unlocking and closing noise.

Of the closing noise, “You want it to be as close to refrigerator (-like) as possible – just a thud,” Verde says, adding customers don’t want to hear the mechanical components inside the latch, but want to know the door has closed.

For the power lock/unlock actuator, Kiekert aims for a very short actuation sound, but at a deep frequency.

The German supplier does not use decibels as the primary measurement of noise, because measuring in decibels is not subjective and high-frequency sound at a low dB is possible.

Says Verde, “Then what you have is people saying, ‘Ah, I don’t like the way that sounds,’ even though maybe they can’t hear it so well.”

Kiekert Electronic Latch Coming

If one of Kiekert’s latest products is a success, latch noise may become a thing of the past.

Kiekert, which began 159 years ago supplying latches to the railway industry, has its first customer for its E-Latch electronic latch. The device will be in production within a year, Verde says, without naming the customer or saying if it will be installed on a luxury application. Electronic latches have been shown on luxury concept cars for at least a decade.

Thanks to keyless entry systems that already are prevalent, E-Latch means a vehicle door could open on its own if its fob is detected on a driver or passenger, sending a signal to the vehicle control module to unlatch the door.

A recognized smartphone or a driver or passenger’s touch on the door or a button also could trigger opening.

A traditional door handle could be paired with E-Latch, but it could be smaller and slimmer.

Kiekert is promoting its E-Latch as a weight-saving measure due to the module’s smaller size and fewer components.

“(In) typical vehicles you have out there today, you have extra weight, counterweight, in order to prevent handles from coming open in inertia situations. These could be eliminated,” Verde says, noting a rough estimate of 0.7 lbs. (300 g) per door could be saved with an E-Latch. While that’s not a lot, automakers are combing today’s automobiles to remove even small amounts of weight in light of more stringent future fuel-economy standards.

Two other products Kiekert presents here at Tech Crawl, i-protect, a door-brake system that aims to prevents dings or dents by sensing nearby objects and LED-Latch, integrating an LED into the latch to warn pedestrians or bicyclists of an open vehicle door, don’t yet have customers.

Kiekert’s main business is side-door latches, accounting for 80% of its revenue, but it also supplies hood latches, latch modules, rear-compartment latches and sliding-door mechanisms.

The latch supplier has 25% market share in the NAFTA region, 35% in Europe and 20% in China, but its products are in one of every three vehicles on the road as its licenses its designs to other manufacturers.

The supplier employs 5,800 people worldwide in 10 different locations, including 1,200 at its Detroit-area U.S. development, manufacturing and sales facility in Wixom, MI.

Kiekert June 14 announces it is investing $1 million in the Wixom facility, to expand manufacturing there from 350,000 door-latch modules in 2013 to 1 million this year.

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