by Jim Kerr
When Volvo came under the umbrella of the Ford Motor Company, I thought that Volvo cars would lose some of their identity under Ford’s large presence but I have been proven wrong. Volvo appears to have retained their strong image of strength and safety. Instead, Ford has used Volvo’s capabilities in safety research and design to strengthen the safety of every Ford vehicle. Here are a couple examples.
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The Ford Freestar is the first minivan to offer a Safety Canopy System that provides both side impact and rollover head protection for outboard passengers in all three rows of seats. Some of this technology comes from Volvo SUV applications but is adapted to the larger size of the Ford minivan. Front seat passengers also get the protection of seat mounted side impact airbags that use the same detection system as the Safety Canopy system.
Four side satellite sensors are used to detect side impacts, sending a signal to the Restraints Control Module to deploy the airbag on the side of the vehicle that is struck and the safety canopy system on both sides of the vehicles. Mounting the front side airbags in the front seats has the advantage of always positioning them correctly in relationship to the seat occupant.
The side canopy deploys down from the roof rail using gas cylinders to pull the inflatable curtain down. The canopy is designed to unfurl as it deploys so that it can be positioned between the side glass and the passengers. When asked what would happen if someone was sleeping with their head against a window, one Ford engineer told me that they had tested for this possibility and the canopy rolls quickly and gently into position, moving the passenger’s head away from the window.
To sense a potential rollover, a sensor packaged inside the Restraints Control Module on the centre tunnel measures roll rate. Impending rollovers are calculated using an energy-based algorithm. The program compares vehicle angle, speed and specific vehicle limits to determine if the safety canopy requires deployment.
When the safety canopy is deployed, it stays inflated for several seconds to protect against both primary and secondary impacts or more than one roll. A new cooler-gas inflator technology reduces the chance of hot gas burns, while low porous bag material slows deflation rates.
Not only does the canopy protect the passengers’ heads from hitting against the side of the vehicle, it also acts as a shield to reduce the possibility of objects entering the vehicle during a roll and helps keep passengers inside the vehicle. The passive safety offered by the Freestar safety canopy is of great benefit to all passengers in a collision or rollover.
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The 2005 Ford Five Hundred sedan, soon to appear in dealer’s showrooms, is also a merger of Volvo safety expertise with Ford engineering. According to Chris O’Connor, Crash Safety Supervisor, “the overall body structure was engineered for safety”. The unibody front frame rails are octagonal in shape, helping prevent them from buckling under a variety of crash conditions. The front bumper plate also has a patent pending new shape. “We discovered that changing the shape and mounting system of the front bumper plates drastically reduced peak crash forces” said O’Connor.
A cross car beam called the SIPS tube (side impact protection system) is used for mounting the front seats and transfers load across the car during a side impact. The tube has a bend in the middle to form a deformation point and reduce crash energy. The SIPS tube works in conjunction with high strength steel B pillars and a structural roof bow that help to protect passengers while the lower portion collapses.
It’s all about force management. Direct the forces of a collision away from the passenger space and into the surrounding structure so that peak crash loads are reduced for occupants. There is much more to the Ford Five Hundred force management design, such as steel sheets made from different thickness material by laser welding them together, driveshafts designed to collapse in collisions and rear frame rails that absorb initial impact forces and then channel them into a secondary crush zone.
While the available side canopy safety system labels may be the most noticeable safety feature, the whole car is designed around safety. Thank you Ford, and thank you too Volvo for keeping safety a priority.