Volvo safety body design
not long after Ford acquired the Volvo car division in 1999, Volvo engineers were surprised. What surprised them was not the new development requirements put forward by Ford, the new owner in the United States. On the contrary, it was a large number of informal technical consultations sent by engineers from various departments of Ford. They showed strong interest in Volvo's strong vehicle safety design ability. Thomas Broberg, deputy director of the Volvo Car Safety Center in Gothenburg, Sweden, said, "we finally have to control this phenomenon to ensure that our engineers have time to do their own work." Most of the technical consulting focuses on the field of body engineering, which is more prominent when Ford asked Volvo to help formulate its global safety engineering technology strategy. Ford's explanation is very simple: for decades, Volvo has designed many of the safest car bodies in the automotive industry. Who else is more suitable to do the same work for Ford brand than Volvo
interior first consideration
Mattias bergwall, Volvo body structure engineer, explained that the first step for him and his team to design the car body is not to directly create an original body shell model and then determine the interior trim according to parameters, but on the contrary, the first step is to locate the passengers of the vehicle and work from their perspective. "How can we design the car safer without taking it?", Bergwall said, "we prefer to first observe passengers from various positions and try to decide what kind of suppression system we may use in the future, and then we can establish body and assembly goals on this basis." This method of determining the design scheme may be quite strange to many automobile manufacturers. For example: the power system is generally regarded as a sacred part. After giving the size, the body engineer will have to work around this size and prohibit any repair and modification. In Volvo, however, this is not the case. There is nothing more sacred than passengers. Therefore, the power train can be adjusted freely to increase the buffer space during collision or reduce the damage of the interior space. Two recent development projects have clarified this. When designing and developing the S40 compact car, Volvo carried out a simulated collision test of the prototype car. The prototype car did not install an engine, and then readjusted the auxiliary parts (batteries, brake boosters, etc.) according to the test results to match the engine room space after the collision, rather than directly designing space for the determined engine size. Through this unconventional method, S40 obtains an additional 200mm collision buffer space for passengers, while the size of the whole car is 48mm less than that of the previous model. Broberg described the upcoming XC90 V8 engine: "we have been committed to the design work so far, so that this horizontally assembled V8 engine can meet our crash test. We know that we can't find such a suitable engine in the entire Ford Motor Company's product library that can be directly applied without changing its components". Therefore, he is just an epitome of many "evaporating condensers' functions. Black technology, which uses the evaporator with low-pressure circulation as the condenser with high-pressure circulation, has designed a new compact 60 in Shenzhen. The engine, only 25 inches wide, is suitable for installation in the post crash space. Broberg summed up a philosophy of body engineering: "you must be mentally prepared for the difficulty of your safety design work at the beginning, or you will start thinking, 'ah, I can't design it, because we don't have that kind of powertrain'."
weight and safety
bergwa10. Change the cooling oil according to the situation. Ll believes that the biggest challenge for his body design team is to establish a balance between safety and weight. In the past, Volvo solved safety problems by adding body parts, such as its sips (side impact protection system), which installs steel pipes under the seat to transmit the side impact force to the impact box in the center of the car. However, this safety device increases the weight of the body, and Volvo has been looking for a better design. Therefore, Volvo engineers are becoming smarter and smarter when redesigning the existing structure, and can effectively absorb more impact forces without adding additional parts. A good example is the redesign of the front body structure of XC90. S80 was once the gold standard of Volvo's safety design, but engineers found a fundamentally different design, which can make XC90 absorb the same amount of impact force as S80, but the weight of the whole vehicle is lighter. Bergwall explained: "For S80, which is mostly caused by the drying of gauze on the wet ball sensor, we set side member beams around the wheel arch to absorb the impact force. This concept depends on the bending capacity of the beam and the node. While the design concept of XC90 is to provide a frame structure, and replace the bending force with pressure and tension. We use the node beam as the final structural member of the front structure. In S80 model, it is only the steering rack Bracket, and now we use it as a structural component of the collision system. This is indeed an effective system to reduce the weight of the car. "
at the same time, Volvo also pays more attention to automotive materials, so as to reduce weight and still meet safety standards. The steel grade used in the new S40 model points out the company's thinking direction. The most basic idea is to use high-strength steel for the parts that bear the main impact and are most prone to deformation outside the car body, and then continuously transmit the impact force according to the steel grade, so that the deformation becomes smaller and smaller until it reaches the hard passenger compartment shell. In order to strengthen the body strength, this material strategy is combined with the actual design concept, which constitutes a basic part of Volvo's method. It is precisely because of its foundation that others often suddenly find that Volvo's body parts are few, but they are large. Why? And feel strange. Bergwall's answer is simple: "if you make two parts that must be connected, you will always have a fragile connection point." When asked about the future trend of body engineering technology, bergwall repeated the same view: "one of our dreams is to say goodbye to spot welding completely, because you can manufacture bodies with higher efficiency and strength without spot welding." Of course, don't expect this to happen soon, but just like other ways to promote safer car bodies, Volvo is constantly working on it
this new S40 body shows Volvo's latest body design. It uses four different strength steels to absorb and manage the impact force. The low-speed deformation area of the front bumper includes a high hardness boron steel beam, which is connected to the longitudinal members to form a "collision box", which is easy to replace and the price is not high. When a high-speed collision occurs, the side members made of high-strength steel with toughness can absorb most of the impact force. (end)