Ford and General Motors worked with their casting 供应商s to reduce vehicle weight with a variety of methods, from replacing material to switching processes.

轻量化 vehicles is not a new concept—the Corporate Average Fuel Economy (CAFE) standards were passed in 1975—but 汽车 manufacturers continue to find ways to trim the pounds. While many of the weight reductions have come from replacing steel with aluminum, more creative solutions have been found to meet strict strength and stiffness requirements while helping improve the overall fuel economy of the vehicle.

Here are three examples of vehicle manufacturers working with their casting 供应商s to engineer lightweight solutions through changes in material, innovative design or a different manufacturing process.

强化肋骨有助于镁取代钢
The structural portion of 汽车 closure panels such as side doors, 提升式门, hoods and trunk lids have been typically produced by joining several sheet steel stampings together by spot welding, 敲定, 粘合剂, 和卷边. Replacement of steel stampings is an ongoing trend in vehicle manufacture, and General Motors identified panels like the side door could be candidates for redesign. 

这些组件是广泛的部件, but the fluidity of magnesium to enable thin sections, coupled with the long die life of magnesium casting, enabled GM 供应商 Meridian Lightweight Technologies to combine the multiple components into a single casting. Engineers incorporated strengthening ribs to increase local stiffness so that the final single magnesium casting met all product stiffness requirements while reducing the mass by 50%. 

通过压铸门, it was possible to vary wall thicknesses to reduce the material w在这里 strength and stiffness was not required. Ultimately, the magnesium door panel weighed 19.4磅. 小于钢结构. 

+, reducing the number of parts meant that 105 spot welds were replaced by 13 mechanically fastened joints.

In areas w在这里 high stiffness was required in order to maintain the door-to-body seal when driving at high speeds, engineers included a ribbed open-section header to meet the requirements. 

最后, producing the door in magnesium via cold chamber high pressure diecasting reduced the number of parts from five to one and cut weight by 48%.

球墨铸铁比铝更重
Reducing weight is not limited to changing the material to something lighter. Auto manufacturers and 供应商s have been studying ways to cut the pounds by designing stronger parts using less material.

Such was the case for a lower control arm for Ford Motor Co.的CD4引擎平台, which is incorporated in vehicles such as the Ford Fusion, 福特金牛座和林肯鹦鹉螺. 在这个例子中, an aluminum part was converted to a ductile iron casting in order to achieve weight savings.

Engineers from Ford worked closely with 供应商s AFS Corporate Member Waupaca铸造 and Hitachi Metals to produce the high-strength, 轻量级组件. 使用设计优化软件, 一个初步的设计概念被构思出来了, and it was then further refined for production feasibility. The design engineering team carefully detailed the mating part interfaces of the arm to enhance durability and ensure proper assembly function and shaped the surface profiles so the component fit into the packaging space. 

通过与福特的合作, 日立金属和威尼斯注册送38元, the final design featured a hollow shape and weighed 25% less than it did at first concept. The thin-wall ductile iron component weighs 19.2磅. 比较了25个.4-lb. 铝版. 

相似的材料，不同的工艺修剪质量
An innovative manufacturing method helped General Motors further reduce the mass of a component it had already converted from a steel assembly to an aluminum assembly.

The five-piece aluminum stamped and welded side door mirror reinforcement bracket was a good start to cut weight, but GM worked with Cosma Casting Michigan (Battle Creek, Michigan) to engineer a casting solution that could further lighten the component.  The bracket provides the attachment points and load carry for the large side door mirror and is crucial to providing stiffness to the side door window frame. 

Cosma Casting opted to use high pressure vacuum diecasting, which creates a vacuum inside the die tooling for every machine cycle to create high integrity, 结构铸件. The die tooling was designed to produce four brackets per cycle for maximum overall equipment effectiveness (OEE). Cosma also modified its tooling to use water free lube for a faster cycle time over the conventional water spray die lube system. A casting is produced every 7 seconds with this system.

The new design represents an additional 20% mass savings of the aluminum stamped solution and 37% mass savings over the steel assembly.     

点击 在这里 to see this story as it appears in the July/August 2019 issue of MCDP.