The Automotive Suspension Systems Report Supplierbusiness

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The Automotive Suspension Systems Report

2013 Edition The Automotive Suspension Systems Report

CONTENTS

Introduction ...... 7 Key market drivers ...... 12

Fuel efficiency and CO2 emissions ...... 12 The United States ...... 12 The European Union ...... 13 Japan ...... 14 China ...... 14 Other countries ...... 15 Materials considerations ...... 15 Increasing electrification ...... 20 Systems integration...... 20 Challenges and barriers ...... 24 Chassis and suspension weight reduction ...... 27 Suspension performance ...... 28 Design compromise ...... 28 Moving from passive to active suspension ...... 30 Kinematics and elastokinematics ...... 34 The ‘Skyhook control strategy ...... 35 Suspension element technology ...... 36 Control arms ...... 37 Front suspension ...... 38 Rear suspension...... 39 Spring systems ...... 40 Pneumatic and hydropneumatic spring systems ...... 41 Electronic spring systems ...... 46 Composite springs ...... 48 Dampers/shock absorbers...... 49 Shock absorber design...... 49 Acceleration Sensitive Damping ...... 50 Gas charged shock absorbers...... 50 Position Sensitive Damping ...... 51 Dynamic Ride Control ...... 51 BWI’s manual selectable ride ...... 52 BWI’s Bi-State real time damping system ...... 52 Adaptive damping system ...... 53 Frequency Dependent Damping (FDD) ...... 54 ZF preloaded valve and vario damper technology ...... 56 ZF Sachs Continuous Damping Control...... 57 BWI MagneRide: Magneto-rheological damping ...... 59

Stabilisers or anti-roll bars ...... 61 Knuckles/Uprights ...... 64 Ball joints ...... 64 Bushings ...... 65 Supplier Profiles ...... 66 Benteler ...... 66 BWI Group ...... 69 KYB ...... 71 Magneti Marelli ...... 74 Mando Corporation...... 79 Metaldyne ...... 83 NHK Spring ...... 85 Sanluis ...... 88 ThyssenKrupp ...... 90 Tower International ...... 95 TRW Automotive ...... 97 WABCO ...... 106 ZF...... 113

FIGURES Figure 1: Conventional suspension compromises [Source: Daimler] ...... 8 Figure 2: Average power consumption 1990 – 2010 for mid size and luxury cars [Source: AABC Europe] ...... 9 Figure 3: Electrical power requirements for NEDC and actual customer requirements for various vehicle classes [Source: BMW]...... 10 Figure 4: The extended performance envelope for fully active suspension compared to conventional passive and semi-active systems [Source: TU München] ...... 11 Figure 5: Fuel economy standards to 2015 for selected countries (US mpg) [Source: Various] ...... 14 Figure 6: The impact of weight on fuel consumption [Source: ZF Sachs] ...... 16 Figure 7: Cost comparison of lightweight vehicle structures [Source: Massachusetts Institute of Technology] ...... 16

Figure 8: Additional costs entailed by tougher European CO2 legislation for a vehicle with emissions of 161g per km [Source: TRW] ...... 17

Figure 9: Average profit per vehicle versus CO2 compliance costs [Source: A T Kearney] ...... 18 Figure 10: The relationship between functions and control units to 2014 [Source: ADL] ...... 20 Figure 11: The growth of integrated functions [Source: BMW] ...... 21 Figure 12: X-by-wire roadmap [Source: Ricardo] ...... 21 Figure 13: An active stabiliser bar system [Source: BWI Group] ...... 22 Figure 14: BMW’s Dynamic Drive system [Source: BMW] ...... 23

Figure 15: Ford Focus control blade rear suspension [Source: Ford] ...... 23 Figure 16: AAM’s I-Ride suspension module [Source: AAM] ...... 26 Figure 17: Contribution to weight reduction [Source: Centro Ricerche Fiat] ...... 28 Figure 18: Conventional suspension compromises for passive and active suspension systems [Source: Daimler] ...... 29 Figure 19: The complex functional harmony required to provide driving quality [Source: Ford] ...... 30 Figure 20: A schematic of active and semi-active suspension [Source: RMIT] ...... 31 Figure 21: A schematic showing the Mercedes-Benz Pre-Scan technology [Source: Daimler] ...... 33 Figure 22: Mercedes Benz’s Pre-Scan technology [Source: Daimler] ...... 34 Figure 23: Axle and multi-axle computer simulation [Source: IAV Automotive Engineering] ...... 35 Figure 24: A schematic representation of the skyhook control strategy [Source: ZF Sachs] ...... 36 Figure 25: Suspension control arm configurations [Source: ZF Friedrichshafen] ...... 37 Figure 26: Typical control arm designs [Source: ZF Friedrichshafen] ...... 38 Figure 28: Continental's 4-Corner air suspension system [Source: Continental] ...... 41

Figure 29: CO2 reduction through the use of pneumatic suspension systems ...... 44 Figure 28: Continental's air suspension system [Source: Continental AG] ...... 44 Figure 30: Bose's fully electromechanical front suspension model [Source: Bose] ...... 47 Figure 31: Sogefi’s composite springs [Source: Sogefi] ...... 48 Figure 32: Acceleration sensitive damping [Source: Tenneco] ...... 50 Figure 33: Audi RS5 chassis featuring dynamic ride control [Source: Audi]...... 52 Figure 34: suspension motion sensors [Source: BWI] ...... 53 Figure 35: A schematic of Tenneco’s Continuously Controlled Electronic Suspension [Source: Tenneco] ...... 55 Figure 36: A schematic of Tenneco’s integrated Kinetic H2 CES system [Source: Tenneco] ...... 56 Figure 37: Comparison between standard and pre-loaded valve performance [Source: ZF Sachs] ...... 57 Figure 38: Graph showing the range in which CDC can continuously vary damping forces in compression and rebound [Source: ZF Sachs] ...... 58 Figure 40: CDC dampers with internal and external valves [Source: ZF Sachs] ...... 58 Figure 42: Cross section of a MagneRide actuator [Source: BWI] ...... 59 Figure 43: Comparison of force-velocity characteristics of a MagneRide damper, typical variable valve dampers and a passive damper [Source: BWI] ...... 60 Figure 44: ZF Sach’s Active Roll Stabilisation system [Source: ZF Sachs] ...... 62

TABLES

Table 1: Weight reduction in lightweight shock absorber assemblies [Source: ZF Friedrichafen] 27

Table 2: Front axle design proportions, worldwide light passenger vehicles (%) [Source: ZF Friedrichshafen] ...... 38 Table 3: Front axle design by segment, worldwide light passenger vehicles (%) [Source: ZF Friedrichshafen] ...... 39 Table 4: Rear axle design proportions, worldwide light passenger vehicles (%) [Source ZF Friedrichshafen] ...... 39 Table 5: Rear axle design by segment, worldwide light passenger vehicles (%) [Source: ZF Friedrichshafen] ...... 40