Variable Valve Trains

The Evolving Engine

Pierburg GmbH Alfred-Pierburg-Straße 1 41460 Neuss Germany

www.kspg.com “We’re working on tomorrow’s

Doubly Complementary automobile engine.” 4-5 UniValve and FlexValve Dr. Dirk Hunkel, Director Business Unit Variable Valve Train Systems, Pierburg GmbH Precision for High RPM 6-7 UniValve – Design and Function

Gasoline or diesel? For years, these arch- inside the combustion chamber while Both Robust and Versatile 8-9 rivals have charged ahead along their keeping the impact on the fuel con- FlexValve – Design and Function independent respective development sumption to a minimum. The fact that paths, each chiding the other with its variability in the air handling system 715/2007/EG 10 -11 own technical advances. Each system provides advantages for both engines is You want to see it in black and white? has its strengths, but also its weakness- undisputed. But variable valve trains es. The stoichiometric gasoline engine offer even more potential. Keywords are The Evolution of Your Engine 12-13 features a highly efficient and cost displacement on demand, scavenging We work with you to produce a bespoke design. effective after-treatment system thanks and engine braking. to its three-way catalytic converter. But “Variable valve train systems are not 14-17 the fuel consumption has to be im- We’d like to show you what variable something you just get off the shelf.” proved. Diesel engines, on the other valve train systems can do. And we’d An interview with Heinrich Dismon, CTO hand, have already reached a very high like to assist you with your decision, efficiency. However, controlling their design concept and right on through KSPG in a Nutshell 18 -19 emissions is more challenging and to SOP. We offer two different variable Who we are. What we do. mostly comes at the cost of reduced valve train systems, which we explain efficiency. The strategy here involves in the following. limiting the production of pollutants

2 3 Doubly Complementary

UniValve: Making FlexValve: The valve your engine fitter train upgrade for for the future. diesel and heavy-duty engines.

Until now, the gas exchange of gasoline losses and pumping work lead to FlexValve is a compact, robust and including those for commercial vehicles, engines has always been associated favorable fuel consumption. efficient mechanical valve train system. which are sold in markets with differing with pumping losses. The reason is that It permits continuous variability emission standards. the throttle body has to be closed for An electrical actuator provides precise of valve lift over a broad range, even part load operation. and quick valve control from full valve lift allowing secondary opening of the valves, FlexValve offers the following down to zero valve lift. UniValve delivers if desired. This gives a lot of flexibility to advantages for diesel engines: UniValve fulfils engine designers’ outstanding fuel economy, dynamics influence the gas exchange process and faster warm up and improved longstanding goal of achieving adjust- and power. engine out exhaust gas temperature. after-treatment efficiency ment of cylinder filling to meet changing improved transient EGR control and/ operating conditions by means of UniValve provides the following In addition, FlexValve is modular, offering or faster T/C response thanks to variable valve timing. advantages for gasoline engines: various modules to change the function secondary valve opening high speed capability of the valve train system without having variable effective compression ratio UniValve has a compact, straightforward favourable frictional behaviour to change the cylinder head design adjustment of load and temperature design. The uncompromising use of good response and manufacture. This makes FlexValve for optimized combustion control roller contacts througout the system inherent cylinder deactivation an ideal solution for diesel engines, Compression release engine braking offers a high speed capability with low up to 12 % improvement in fuel mechanical losses. Reduced parasitic economy

4 Comparison 5 3 UniValve: 4 Precision for High RPM 1

Design and Function 5 UniValve features two mechanical cam How UniValve works 2 mechanisms in series. The UniValve The UniValve rocker (1), which rests rocker assembly is the heart of the on the control shaft (2), is guided by 6 system. The camshaft keeps it moving in the circular guide (3), and is set in an an oscillating motion and the assembly oscillating motion by the camshaft (4). subsequently transfers its movement to UniValve components the roller finger follower. Position and The UniValve rocker has a profile (5), Besides the typical valve train parts, such as a camshaft (4) and a orientation of the UniValve rocker are which is in contact to the roller finger roller finger follower (6), UniValve changed to give the desired family of follower (6). The profile includes a base has only three additional continuously variable valve lifts. circle and a lifting curve which together components: form a “swinging cam.” – UniValve rocker (1) UniValve can also completely deactivate – Control shaft (2) – Circular guide (3) individual valves, fully shutting down The control shaft (2) is shaped in a way, their respective cylinders. Now, that’s that its rotation controls the movement downsizing on demand. of the UniValve rocker. This varies the relative lengths of the base circle and Strong on every side the lifting curve used. Even greater potential is available with the use of UniValve on both the intake An electrical actuator steplessly turns and exhaust sides, particularly with turbo the control shaft, rapidly and precisely engines. to provide continuously variable position-control of the shaft and hence the valve lift. Contact: Dr. Michael Breuer All contact points are fitted with roller [email protected] bearings to minimise friction.

6 UniValve 7 4 FlexValve: 3 Both Robust

and Versatile 5

Design and Function

FlexValve is based on DuoCam, a twin Depending on the shapes and relative cam camshaft as the name indicates. angular positions of both cam groups, 6 An actuator, similar to a cam phaser, the FlexValve rocker either rotates about changes the angular relationship of the the pivot shaft (6) or generates a valve 7 shaft and tube and hence their associ- movement. Different cam contours are ated cam lobes, which are in contact with possible and through their design can the FlexValve rocker. The FlexValve rocker produce multiple valve openings. The “adds together” the two cam profiles. figures show two of the potential lift Thus, altering the angle between shaft curve families. and tube allows the valve lift to be varied. FlexValve is modular. This allows the FlexValve components FlexValve employs a DuoCam to The FlexValve system comprises a single engine to be built to different specifica- replace the conventional camshaft lobe (1), pinned to the inner shaft (2) of tions without cylinder head design and two other parts in addition to the the DuoCam shaft. The two outer cam changes. This provides the freedom to conventional valve train system components: lobes (4) are fixed to the tube (3). The implement conventional valve timing, – FlexValve upper rocker assembly (5) phasing between the lobes (1) and (4) a DuoCam version with variable valve – Return spring (7) may be varied via an actuator, (not shown timing of two groups of cam lobes, or for clarity). the full FlexValve system.

The rollers of the FlexValve rocker (5) follow both cam profiles. This rocker pivots on a shaft (6), which connects it to both finger followers. The return spring Contact: (7) keeps all the parts in contact when Dr. Tim Lancefield the valves are closed. [email protected]

8 FlexValve 9 715/2007/EC

160 160 2500 This European Parliament regulation the penalty fees that will apply as of 2000 calls for the reduction of the average 2020 and the European fleet average 140 140 Actual in 2012: 135 g/km 1500 fleet consumption and the cutting of for 2012. 1000 carbon emissions produced by European 120 120 Target 2015: 130 g/km 500 automobile manufacturers to 95 g/km Our own surveys indicate up to 12 % by 2020. fuel reduction in the mapping area with

3.6 l Diesel the same or even improved full load and 4.1 l Gasoline 100 100

This chart shows the targeted values for emissions performance in g/km depicted emissions

2 Target 2020: 95 g/km

2015 and 2020, as well as values that are 80 C O 80 penalty fee payment in for 2020 in for payment fee ISO penalty in discussion for 2025. You’ll also find Proposal 2025: 68 – 78 g/km 1375* 60 60 2 4 6 1100 1200 1300 1400 1500 1600 1700 Fuel consumption kerb weight in kg shown as l/100 km * ∅ Mean kerb weight of European motor vehicles 12% Up to 12 % fuel consumption reduction This chart shows the targeted values for 2015 and 2020, as well as values that are in discussion for 2025. You’ll also find the penalty fees that will apply as of 2020 and the European fleet average for 2012.

Our own surveys indicated a 12 percent reduction in consumption with the same or even improved full load and emissions performance.

EU Targets for 2020

95 g/km CO2

4.1 l/100 km average Gasoline fleet consumption

3.6 l/100 km average Diesel fleet consumption

10 Facts and Figures 11 The Evolution We work with you to produce a of Your Engine bespoke design for the future.

A component can perform to its full No, we design your valve train system potential only if it integrates perfectly to meet your specific requirements. into its technical environment, which That’s only possible if we work closely is why we wouldn’t sell you an off-the- with you. In the following, you’ll learn shelve valve train system. what we mean.

Initial Cooperative Prototype Manufacturing

discussion engineering building Not until all parties are convinced that the variable valve train meets all of In this phase we ask many questions, During the design phase, our engineers As soon as all your product specifications your requirements, do we begin regular because we desire to know exactly how work closely with your engineers. Thanks are clear, your expectations understood manufacturing operations, on our you envisage your variable valve train to this cooperation it is possible to and the first variable valve train models premises. Here is where we manufacture, system. And of course, we‘re interested provide you with a tailor-made solution have been designed for your engine, we assemble, test and inspect your variable in learning about what you expect from for your engine. We meet regularly with begin with the building of a prototype. valve train system. You profit from our your work with us. Together, we lay the your engineers to discuss projects and This way, you can become familiar with decades of experience in the manufacture groundwork for the engineering of your their status, including comparing current how our system functions and what you of mechatronic components. Following a system, defining the technical objectives, mechanical designs and variants. And, can expect from our system during your final quality inspection, we ship our fully cost and timing. together with you, we check to make sure engine‘s service life. Together, we then variable valve train product directly to your our work is in line with your expectations. determine which enhancements or production line. There, too, our engineers changes are necessary to the valve train. are onsite to assist you with getting the final details straightened out and getting your operations up and running as you expect.

12 Cooperative Engineering 13 “Variable valve train systems are not something you get off the shelf.”

Heinrich Dismon speaks about Mr. Dismon, how long have you been to put the technology to work for us – variable valve train systems and the working on variable valve train systems? improved materials, improved manufac- future of motor vehicle engineering. In 2007, I was the senior director of turing processes and particularly advanced engineering at Pierburg. Back advanced control technology. then, we carefully considered which products we would have in our portfolio Are there other technologies besides KSPG Automotive CTO today, which are suitable for the future mechanical systems? and which new products would be a Yes there are various hydraulic and good fit for Pierburg. The variable valve electrical systems. We have considered train system was one of these. all of them extensively. After our review of technical options we chose mechani- And you believe that variable valve cal systems with advanced electronic train systems are a technology for the controls. future? Absolutely. We’re taught at university Why did you decide on mechanical that variable valve train technology is systems with electronic controls? a very effective means of reducing fuel An enormous advantage is the opera- consumption in gasoline engines. tional robustness: even in adverse conditions, such as cold starts or low Then, the technology isn’t completely battery voltage. Mechanical systems are new? also more durable. And their similarity No. There exists an often-quoted patent to the conventional valve train systems from Louis Renault from 1908, when he helps keep the costs within reason, received patent rights for his variable because we can use familiar, estab- valve train technology. Over a hundred lished vendors and processes, while years ago, people had good ideas! requiring only slight modifications to They just didn’t pursue them to their the engine layout. That is a major realisation. Today, it’s very current, advantage. because we have everything we need

14 Interview 15 Eventually, you decided to go with two With both systems, you work closely In the past, it was significantly harder Are such standards realistic? systems: UniValve and FlexValve. Why? with your customers. Why? to justify investing in fuel economy, You should never say “never” in We began with UniValve – our preferred Variable valve train systems are not however, with the new EU regulations technology. system for all gasoline engines. But it the kind of components you pull off the things have changed. Have things soon became clear to us that there was shelve and say, “install it.” Rather it is gotten easier for you? Currently, America is discovering natural also demand for an alternative system. necessary to adapt or design them for No, not really. The market is still highly gas as a fuel for motor vehicles and in So we decided to invest in FlexValve. their specific application. competitive. Europe people are increasingly showing For the past year, we’ve worked interest in alternative fuels. How certain simultaneously on both systems. Since How long does the joint engineering of Competitive in terms of price? is variable valve train technology’s both systems have specific functional a new product typically require? Chiefly. Nobody does anything anymore future? differences, there is no danger of them Well, we’re operating in OEM territory just for the love of technology. Every Oh, I’m very upbeat. I believe the competing directly against each other. here. We have to be very integrated effort has to be justified by a benefit. internal combustion engine will be with in our work with the OEMs. Usually, The rules of the game have changed us for quite a while. By the way, natural You have different products for different it takes several years before regular pro- significantly. European legislators have gas engines benefit from variable valve target groups? duction can begin. set a limit and determined that those train technology, too. Although electro We do. FlexValve is more for diesel who don’t remain under the limit will and hybrid vehicles may gain momen- engines whereas UniValve is clearly Integrated means your engineers be hit with penalty fees. The fees are tum, they surely won’t find use every- designed for gasoline passenger work on-location with the customer’s naturally drastically higher than the where. vehicles. The reasons for using variable engineering department? cost of technological development, valve train technology in diesel and Yes, frequently. Our engineers are often assuming you can keep pace. The What is the future’s ideal variable valve gasoline engines are distinctly differ- on site. Why? Because variable valve current European fleet limit of 95 grams train system like? ent. Its application in gasoline engines train systems aren’t like other KSPG is already a challenge. And the 68 to The ideal variable valve train system of is desirable as a means of cutting fuel parts. You can’t just bolt them some- 75 they’re currently discussing for 2025 the future will be versatile and adapt- consumption in order to comply with where onto the engine. Moreover, the is even more ambitious. able. That means it has to be a freely the carbon emission limits for fleets. cylinder head is a highly sensitive area. configurable system that accommodates And for diesel engines, it helps meet For this reason, we have to work very every imaginable timing scenario. And toxic emissions legislation require- closely with the OEMs. then it will have to be controllable ments, without negatively affecting cylinder- or even cycle- wise. Our current fuel economy. Exhaust gas temperature Is working so closely with customers systems represent a step in the right management is the buzz-word. That’s something new for Pierburg? direction. And we have further ideas in FlexValve’s objective. In addition, By no means. Although, we can say development, too. FlexValve is very modular, providing the that this is the first time were working choice between either non-variability “in” and not just “on” engines. That is or maximum variability. The variability certainly special for Pierburg. expands in three different steps and doesn’t require significant modification to the engines.

16 Interview 17 For clarity: Hardparts: Whether engine block, plain When it comes to details, we’re your bearing, large or small bore pistons, this specialists, because we never lose sight What KSPG does. KSPG division designs, manufactures of the whole picture. Our project teams and sells custom solutions for internal usually comprise of specialists from over 12,000 people across the globe. combustion engines used by passenger every division, which is the only way to In a nutshell, KSPG designs and KSPG’s Hardparts, Mechatronics cars, commercial vehicles, ships and produce components and technologies manufactures engine parts and provides and Motorservice divisions together stationary machinery. to produce clean and efficient power for all the associated services. But there’s produce a total turnover of 2.4 billion our transportation in the future. more. We are amongst the world’s 100 euro. Mechatronics: As an engineering largest Tier 1 suppliers to the automo- partner to the automobile industry, the tive industry. And we play a key role in Pierburg unit designs the technologies shaping the engine’s future. and products that enable tomorrow’s engines. EGR systems, valves, actuators The KSPG Group belongs to the and pumps are Pierburg’s forte. Rheinmetall Group and employs Motorservice: This division is KSPG’s sales organisation and handles all the global after-market activities, while providing wholesalers, engine service businesses and service garages with parts.

Europe 22 locations in Germany, Divisions Hardparts Mechatronics Motorservice France, Great Britain, Italy, Spain, Czech, and Turkey

Core brands 1

1 3 12 1 3 4 1 2

2

1 2 Asia 6 locations in China, North America India and Japan 5 locations in the Business segments USA and Mexico 1

South America 1 location in Brazil

18 KSPG in a Nutshell 19