Designers who want to model and prototype automotive components have been given a number of new tools in recent years . 3D modelling in the form of office modellers and various stereo-lithographic form-generators can provide the designer with a close simulation of the shape . Such models are of value as design aids for first-order reality and also for volumetric fit-and-function aspects of the item but they are not the real thing .
These models can sometimes be used as patterns for secondary processes such as vacuum casting or RIM-moulding in epoxies, polyurethanes, polyesters and similar two-component of these materials, although stronger than the computer generated models, are suitable for formal prototype testing, early to market batches ,or for production use.
Safety approval
Obtaining type approval and safety certification in vehicle testing requires that all functional and flight-critical parts of the vehicle tested must be to the exact design specification and be manufactured in production intent materials. Nothing else will do, and the process required in the case of plastic parts is invariably injection moulding in thermoplastics.
The investment in full production tooling for this purpose at such an early stage, when testing may still highlight essential last-minute design adjustments, has an element of risk against which there is little insurance once serious metal cutting has taken place.
However, a series of identical prototypes, pre-production batches, full production up to 3,000 items, all in a choice of injection material and furthermore in the most complex of intricate designs, has been available to designers for almost 25 years.
Space Puzzle Molding
Space Puzzle Molding (SPM) is used regularly by every major automotive company in Europe as a rapid pre-cursor to full tooling at less than half the cost.
Porsche, Mercedes, BMW, Renault and VW are all long-established users of SPM, a process available exclusively from the patentees, Konrad Hofmann GmbH of Fuerth Germany trading under the banner of protoform.
Downstream tier 1 suppliers such as automotive component specialist Dr Schneider are typical multiple product users of SPM and many clients are finding that, in the case of specialist low-volume build vehicles with a high degree of niche-market customisation, the final production run can be more than covered without the need to tool up for mass volumes. The advantage is that tooling can be refreshed after a few thousand cycles, giving the opportunity to incorporate changes to the design.
One recent example illustrating size complexity and flexibility is one of a series of radiator top and bottom mouldings, the tooling for which the producer could provide five niche variants on demand. The design in this case was optimised by protoform to compensate for warpage and cooling factors since the straightness and form of the final product was vital.
The essence of SPM lies in the technique of the 5-axis CNC high-speed machining of a set of metal tooling from the designer’s computer aided design (CAD) data, the space-puzzle like pieces define the volume in the immediate vicinity of the product surface only.
These relatively lightweight elements of the mould can be manually assembled using special tools and assembly fitted by robot arm into a patented reinforcement bolster that remains permanently attached to a conventional injection machine.
The resultant product is a perfect Class A quality series-identical moulding in the correct material and conforming exactly to the design specification. This is suitable for type approval, market launch and ongong production in advance of mass production tooling.
The well-established protoform formula, made up of design optimisation, low tooling cost, rapid timescale,early-to-market production rates and acceptable levels of item cost makes a perfect match for new products from 2g to 2.2 g shot weight and generally within the dimensions 800×400×200mm and in quantities up to 3,000 items. The envelope is flexible for larger items that are not oversize in all three directions.
There is a philosophy that protoform shares with new clients,one of no compromise on quality, performance or service. Within the criteria claimde for the process and irrespective of complexity,SPM does exactly what it says on the box,producing mouldings to the client’s CAD data rapidly, economically and repeatedly.
参考译文：
模制和制造汽车部件原型的设计师们在最近几年内获得了大量新工具。办公室造型者形式的3D模型化以及各种立体平面印刷形式的发生器均能够为设计师提供形状逼真模拟。这种模型很有价值，因为该设计辅助用于部件的一阶实体及体积配合和功能，但是它们并不是真实的东西。
有时可将这些模型用于环氧树脂、聚亚安酯、聚酯和类似双组分热固树脂真空铸造和RIM模型的二次加工。尽管这些材料的强度都高于计算机生成的模型，但是它们都不适合在早期市场分批的正式原型试验或生产中使用。
安全许可
获取车辆试验的类型许可和安全证书要求的待测车辆的所有功能部件和关键运动部件都必须准确遵循设计规范，并且使用生产专用材料进行制造。其他材料均无法代替，而塑料部件所需要的工艺始终是注塑成形。
试验强调最终设计调整的必要性，早期对成批生产加工的投资存在着一定的风险，因为它基本没有防止发生严重金属切削的措施。
但是，一系列相同的原型、试制批量达3,000件的批量生产都采用了注塑材料以及更复杂的设计——设计师们已经使用了近25年。
空间复杂成型
而如今欧洲各大汽车公司都采用的空间复杂成型（SPM），将其作为全面加工的前一工序，从而降低了一半以上的成本。
保时捷、梅赛德斯、宝马、雷诺和大众汽车公司一直都是SPM长期的用户，这种工艺只能从专利所有者——Protoform名义下的Konrad Hofmann GmbH of Fuerth Germany Trading处获得。
下游一级供应商，例如汽车部件专家Schneider博士，都是SPM典型的多产品用户。许多客户发现，当使用高级细分市场定制化设计低容量车辆时，最终的生产过程能够超出所覆盖的区域，而且无需加工大体积部件。它的优势在于可以在经过数千次循环后对工具进行更新，从而可以在设计中加入新的变化。
最近的一个证明尺寸复杂度和灵活性的实例就是一系列散热器顶部和底部造型中一个，它的工具可以由生产者根据需要提供五种细分变型。因为最终产品的平直度和形状很重要，所以该案例内的设计由Protoform优化，补偿了翘曲和冷却因素。
SPM的实质在于根据设计师计算机辅助设计（CAD）的数据，使用一套金属刀具进行5轴CNC高速加工，空间复杂结构（例如部件）只确定产品表面附近的体积。
这些模型相对较轻的部件可以使用专用工具手动装配，而组件则由机器人臂装入专利的增强承架上，并且持久固定在常规注塑机器上。
这样生产出来的产品是与完美的A级质量系列模型，使用的材料正规，并且完全遵循设计规范。此种产品类型适用于认可、投入市场以及批量生产加工前的生产工艺。
沿用已久的Protoform公式，由优化设计、低加工成本、快速时间表、早入市场生产率和部件成本的可接收水平组成。这一公式非常适合于2g至2.2g喷射重量的新产品，尺寸通常在800×400×200mm内，而数量可达3,000个。而它的外壳是势在挠性的，可以用于三维尺寸都没有过大的稍大部件。
Protoform告知新客户，Protoform的理念是绝不降低质量、性能和服务标准。在工艺要求的标准范围内，不管复杂度多高，SPM都要完全做到它的承诺：根据客户CAD数据快速、经济和可重复地生产模型。
