今年晚些时候，Freevalve AB 公司的无凸轮轴发动机将由观致汽车 (Qoros) 完成评估。未来，这种名为 Qamfree 的技术将有机会真正走入量产发动机，为发动机工程师的动力系统设计与制造带来新的维度。

除了奇瑞旗下的观致汽车，还有另外两家汽车厂商也被认为有计划采用Qamfree系统。

Freevalve公司在 2003 到 2017 年间曾为瑞典超跑制造商Koenigsegg AB 的姐妹公司，目前已经成为一家独立企业。与其他无凸轮轴设计发动机不同，Freevalve 的 Qamfree 系统使用“气动-液压-电子”促动器 (PHEA) 来取代传统凸轮轴。Freevalve 公司的工程师指出，这可以在完整气门进程中提供更精准的控制，并在进气和排气两侧提供气门提升。

2016 年北京车展期间，这款 Qamfree 系统曾搭配一款 1.6 L 4 缸 16 气门 DOHC 涡轮增压汽油发动机一同登陆一辆观致概念车，完成首次公开亮相。Freevalve 工程师声称，与采用传统凸轮轴发动机的同等规格车型相比，这种无凸轮轴设计可以为车辆提供 47% 的动力提升、45% 的扭矩增加，以及 15% 的降耗表现。

Freevalve 公司指出，任何负载等级的发动机采用 Qamfree 系统后，进气和排气侧的气门定时均支持独立编程，系统则将根据具体驾驶条件，决定采用哪种配置，以实现性能最大化，或燃耗和排放最小化。

CTO Q&A问答

这款发动机不仅没有凸轮轴，而且也没有使用相关配套硬件，包括节气门、凸轮轴驱动、定时齿轮和外壳、排气门、预先催化转换器，及直喷系统等。系统配备了专用的阀门位置传感器。与常规发动机相比，无凸轮轴发动机不仅在减重方面具有优势，与采用常规气门的标准发动机相比，无凸轮轴发动机的燃料消耗量在“正常”驾驶工况中可降低 10%。

Qoros 和 Freevalve 公司正在利用一款具体型号未知的观致车型，共同对这种无凸轮轴概念设计进行测试评估。

随着评估接近尾声，Freevalve 首席技术官 Urban Carlson 接受了《汽车工程》欧洲总编 Stuart Birch 的采访，共同讨论无凸轮轴发动机及其应用及影响。

SAE：对于一些更保守的厂商而言，Freevalve 公司的设计会不会太激进了？

Carlson：对，没错。不过，为了满足即将实施的排放法规，汽车厂商仍有充分理由选择尝试我们的系统。此外，人们现在越来越热衷开发先进的发动机控制策略，而我们的概念设计非常符合内燃机的这种发展趋势。我们的优势在于技术更新颖，参数表现更优秀，从而更好地满足汽车厂商实现发动机精准控制的需求和目标。

SAE：Freevalve 并不需要一些价格昂贵的传统组件，那么如果产量达到一定规模，这种发动机的成本是不是会低于常规的同级别发动机呢？

Carlson：是的。在没有小型化的情况下，1.6 L 涡轮增压发动机即可节省约 20 公斤（44 磅）重量。通过紧凑安装和进一步优化，我们预计 Qamfree 的完整设计可以降低发动机的整体成本。我们的成本评估显示，Qamfree 系统的成本应与汽油直喷发动机组件相仿，需要采用一些更先进的后处理系统，比如颗粒过滤器。我们预计，与同等性能的柴油机相比，汽油机搭配 Freevalve 系统的成本要明显低的多。

SAE：除了观致公司，在不久的将来是否还有其他厂商采用无凸轮轴发动机技术？

Carlson：是的。市场导入当然还需要一定时间，但我们正在同时跟进几个不同领域的项目。我们预计，至少有两家客户将在明年公布他们的计划。

SAE：目前多个国家均已表示，将在 2040 到 2050 年间逐步立法淘汰内燃机汽车，从而支持电动汽车的发展。您认为无凸轮轴发动机是否能在这种巨变下为内燃发动机带来更多机会？

Carlson：我们肯定无法预见所有地缘政治因素，但从更广义的层面看，内燃机的性能可以通过采用 Freevalve 的系统得到显著改善。在包括公路、铁路和航运在内的交通运输领域中，更多的关注已经转移至为内燃发动机选择替代燃料。液态烃类的储存和配送非常方便。基于风能和太阳能的 P2G（电转气）燃料将迎来巨大机遇，GTL（天然气r制合成油）领域也将实现巨大进展，可再生能源的气态和液态燃料极有可能在这段时间实现大规模生产。

Freevalve 技术将在高性能多燃料发动机及其他热力循环发动机的发展中发挥重要作用。从近期来看，电动汽车的发展的确风头正劲，但未来的情况谁也说不准。

SAE：您能透露更多项目细节吗？比如项目是什么时候开始？预计什么时候完成？具体涉及哪些方面以及最近的进展情况？

Carlson：评估项目从 2015 年开始，预计将于今年年底完成，涉及的方面很多，包括扭矩、功率、油耗、排放、包装及减重等。

SAE：除了目前的 1.6 L涡轮增压发动机 (169 kW) 外，未来还有其他不同排量和功率输出等级的发动机采用 Qamfree 系统吗？

Carlson：这个问题应该由观致的管理层回答。我们目前的项目是曾在 2016 年北京车展上展示过的发动机平台。

SAE：Qamfree 将在哪里生产？您已经拿到生产编号的信息了吗？

Carlson：从目前的信息来看，观致和奇瑞的生产和装配都是仅在中国进行。2016 年，这两家公司共生产了大约 40 万辆汽车。

Later this year, concept evaluation of Freevalve AB’s radical camless engine technology is expected to be completed by Qoros Auto. The technology, known as Qamfree, could lead to volume production, bringing a new dimension to powertrain design and engineering.

Besides Qoros (owned by Chery Automotive), two other OEMs are also understood to be potential adopters of the system.

Freevalve was a sister company of Koenigsegg AB, the Swedish supercar maker, from 2003-2017 and is now independent. Its Qamfree system differs from other camless designs in that it uses pneumatic-hydraulic-electronic actuators (PHEA) to replace the camshaft. Freevalve engineers state that this delivers more precise and completely customizable control over valve duration and lift on both the intake and exhaust sides.

A demonstrator 1.6-L 4-cylinder 16-valve DOHC turbocharged gasoline engine fitted with the system was first seen at the 2016 Beijing Motor Show in a Qoros concept car. Company engineers claimed it demonstrated a 47% increase in power, a 45% increase in torque, and a 15% reduction in fuel consumption compared to a regular camshaft-equipped engine with similar specifications.

Freevalve states that for any engine load criteria, the timing of intake and exhaust can be independently programmed, the system deciding which one to maximize performance or minimize fuel consumption and emissions, depending on driving conditions.

Q&A with the CTO

The engine dispenses with not only the camshaft itself, but also associated hardware: the throttle body, cam drive and timing gear and cover, wastegate, pre-catalytic converter and direct injection systems. It has proprietary valve position sensors. As well as significant weight saving, packaging efficiency gains include 50mm (1.9 in) off the height and 70mm (2.7 in) off the length of a comparable regular unit. Vehicle fuel consumption is reduced by 10% during "normal" driving compared to the baseline engine with normal valvetrain.

Qoros and Freevalve are working together on the concept evaluation, using a fleet of test engines to refine the technology for use in an as yet unspecified Qoros model.

With the concept evaluation phase approaching scheduled completion, AE's European Editor Stuart Birch discussed the new technology and its implications with Freevalve’s Chief Technology Officer (CTO) Urban Carlson.

Q: Is the Freevalve technology's radical design challenging for the more conservative OEMs?

That is what we expected, but the technical challenges meeting the market demand with coming emission legislations seems to be a stronger factor. We also feel that our concept fits well into the development trends of the combustion engine where people are increasingly interested in developing advanced control strategies. Our fit is that we provide new and powerful parameters to facilitate these needs and wishes.

Q: Some traditional, expensive components are not required for a Freevalve engine, so would its cost be lower than that of a similar capacity regular engine given comparable production volume?

Yes. Without downsizing, the weight saving is around 20 kg [44 lb] for the 1.6-L TC engine and with further optimization in combination with a more compact installation we expect the complete concept to reduce the overall cost. Our cost estimates indicate that our system will be similar to that of a gasoline DI engine, requiring more advanced after-treatment, such as a particulate filter. We expect gasoline engines with the Freevalve system to be significantly cheaper than diesel engines having the same performance.

Q: Apart from Qoros, can we expect to see the technology adopted by any other manufacturers in the near future?

Yes. There is, of course, a lead time for market introduction, but we are working in parallel with projects for several different segments. We expect at least two customers to announce their plans during next year.

Q: Many countries are now indicating that the ICE in new cars is going to be increasingly legislated out of existence in favor of EVs by 2040-2050. Do you see your engine offering an alternative to this radical change?

We can of course not foresee all geopolitical factors, but the ICE as a more general definition can be improved significantly with the Freevalve system applied. Within the transport sector - on road, rail and sea – more focus is directed towards alternative fuels for the ICE. Liquid hydrocarbons are very efficient to store and distribute. With great opportunities for wind and solar based P2G (power-to-gas), as well as great developments within GTL (gas to liquid) technologies, renewable gaseous and liquid fuels will most likely be produced in large quantities within this timeframe.

The Freevalve technology has an important role to play in efficient fuel-flexible engines and in engines switching to other thermodynamic cycles. Even if it is tempting to extrapolate the current EV trends, the long term future of transportation is far from decided.

Q: Can you put some detail on the program such as when did the program start and when is it expected to be completed, what it involves – and how it is progressing?

The concept evaluation, started 2015, is expected to be completed by the end of this year. It has involved torque, power, fuel consumption, emissions as well as packaging and weight optimization for vehicle installation.

Q: Would there be other engine capacities and outputs besides the 169-kW 1.6-L turbo version?

That is a question for the Qoros management to answer. The project we are doing is for the engine platform shown in public in 2016.

Q: Where would the Qamfree be built and do you have any indication of production numbers?

Qoros and Chery build cars and subassemblies only in China as for today. Together they built approximately 400,000 cars in 2016.

Author: Stuart Birch
Source: SAE Automotive Engineering Magazine