GM has filed a patent application for an electromagnetically latched liftgate designed to improve NHV (Noise / Vibration / Harness) inside a vehicle cabin. The patent application was assigned patent number US 2024/0271467 A1 with the United States Patent and Trademark office and was published on August 15th, 2024. The patent was originally filed on February 9th, 2023 and lists Indian-based engineer Murali K. Konga as the inventor.
The system described in the patent application aims to reduce NVH in the vehicle cabin by using electromagnetically latched mechanisms to improve the overall lift gate acoustic performance, specifically low-frequency noises often generated by flexing and movement of the lift gate while the vehicle is on the move.
In the system described by the GM patent application, the lift gate is attached to the vehicle using both mechanical and electromagnetic latches. The mechanical latch secures the lift gate in its closed position, while the electromagnetic latch is selectively energized to apply additional force that pulls the lift gate closer to the vehicle structure, constraining its movement. This reduces any displacement of the lift gate that could otherwise result in vibrations or noise transmission into the cabin.
The system also involves a control module that monitors various vehicle operating conditions, including speed and gear position, activating the electromagnetic latch based on those conditions. For instance, under higher-speed driving conditions or during specific driving modes where noise sensitivity is higher, the electromagnetic latch can be engaged to tighten the lift gate, reducing the potential for acoustic disruptions.
One key advantage of this system is its ability to actively adjust to different vehicle conditions, allowing for improved acoustic performance only when necessary. Additionally, the use of electromagnetic latches allows for more precise control of liftgate positioning, offering better flexibility compared to traditional mechanical latching systems.
As vehicles become increasingly more refined, even in traditionally utilitarian segments, this electromagnetically latched solution could help with NVH levels, particularly in SUVs and crossovers. Furthermore, the system is designed to seamlessly integrate into the vehicle without compromising the aesthetics or the functionality of the lift gate.
Comments
This has “bad idea” written all over it. Especially in rear end collisions.
How did you come to that conclusion?
A magnet is a better safeguard from opening than a physical latch?
The magnetic lock is also to prevent a door from rattling. Also, magnetic locks have been used for many years to secure doors. My son’s school uses magnetic locks on all the doors to prevent people from walking in off the street. You’re not getting these doors open unless someone lets you in.
Not just schools. Many door intended to act as a security barrier or to be released on activation of a fire alarm. But these doors with enough force can still be broken open. Ok we’ll see how this plays out in a car but they will need atleast 120 V to work.
85ZingoGTR
Where would a normal vehicle get 120 v D.C. in order to operate the electromagnets. Electro magnets only operate on D.C. current.
Non-starter. Too much energy is going to be consumed by those electromagnets. Even used sparingly, power hog.
This only proves that there are people out there that are overly sensitive and should likely live in a hermetically sealed sphere where nothing can disturb them. I have driven all kinds of vehicles in all kinds of conditions at all rates of speed and I have yet to recognize a Noise / Vibration / Harness issue emanating from the tailgate, etc. Somebody has too much time to waste, is trying to keep their job, or is in a department that has too big a budget. One more thing to go wrong.
except that you are not everybody. my dads 97′ 4runner tailgate rattles over EVERY bump, and it is very annoying.
One of our company vehicles is a Ford truck with that rattle trap pull out step tailgate. Nobody wanted to drive it because of the rattles. So I bought a rare earth magnet put it on the inside where the step slides into the gate and it fixed the problem. Same concept.
“ The system also involves a control module that monitors various vehicle operating”
So ANOTHER module and system to have problems. More computer chips to wait for.
Basically this is a bandaid for bad engineering and sloppy assembly. GM build it right the first time; don’t rely on a computer to tighten the doors down.
“It’s magnetically sealed.”
K.I.S.S. Quit over complicating stuff.
Some questions: What happens if the vehicle loses electrical power, would the lift gate no longer be held closed? How long will the vehicle battery last if the vehicle were not driven for an extended period of time? As previously mentioned, how will the lift gate be held closed in a severe accident where the d-pillars are damaged?
It would be nice if someone could get answers to all the questions that are asked on this story.
As I read the article, the conventional latch is augmented by the magnets…..not replaced by the magnets. I agree that this seems like something else to fail though.
Just because a patent has been applied does not mean it will be applied at this time though.
Ummm, it’s Noise, Vibration and Harshness, not harness 🙄.