Junichi YajimaChief Powertrain Engineer

Powertrain Engineering DivisionNissan Motor Co., Ltd.

VVEL Technology BriefingVariable Valve Event & Lift System

July 13, 2007

Agenda

1. The Powertrain Concept2. Benefits of VVEL3. VVEL Structure4. VQ37VHR

1. The Powertrain Concept

Environment

Dynamic Performance

Dynamic Performance

Trust:

Safety

Driving Pleasure:

Dynamic Performance

Environment

Trusted Driving PleasureTrusted Driving Pleasure

1-1. Core Values of Nissan Technology

Safety

Environment

Quality, Cost

Life on Board

UltimatePowertrain

CO2 reduction Emission

Performance

Efficiency

Emotion

1-2. Powertrain Engineering ConceptNissan's powertrain development aims to develop an ultimate

powertrain which balances 3 factors [Emotion, Efficiency, Emission] at a high level

Emotion

Efficiency Emission

Emotion

1-3. VVEL Concept

Efficiency Emission

VVEL

VVEL highly-balances 3 factors [Emotion, Efficiency, Emission]

What is VVEL?

Benefits of VVEL

2. Benefits of VVEL

2-1-1. What is VVEL?

VVEL

Conventional engines have one-type cam lobes, limiting it to one pattern of movement

VVEL combined with C-VTC enables continuous valve movement

Conventional Engine VVEL-equipped Engine

Constant intakevalve lift

Variable intakevalve lift

The fixed cam which moves the valve, enables intake-air control at throttle valve opening

Throttle

open/close

Throttle

open

VVEL controls intake amount through intake-valves of the combustion chamber, where conventional engines used throttle valves

2-1-2. What is VVEL?

Direct intake-air control with continuously variable valve lift

Conventional Engine VVEL-equipped Engine

What is VVEL?

Benefits of VVEL

2. Benefits of VVEL

In driving condition on a flat road at constantly 40km/h(when accelerator is pressed halfway or less) there is little pumping loss with VVEL-equipped engines

Throttle Valve Close

NegativePressure

Choking

Big negative work(pumping loss)

Valve Throttle(=non throttle)

AtmospherePressure

Throttle Valve Open

little negative work

Similar condition to the large amount of strength needed to pull a thin syringe needle. (large pumping loss)

Similar to good condition where little strength is needed to pull thick syringe needle. (little pumping loss)

Conventional Engine VVEL-equipped Engine

2-2-1. Benefits of VVEL – Fuel Efficiency(When throttle opening is small)

In driving ranges of small throttle opening, intake-valve lift can be kept low to reduce camshaft friction compared to conventional engine

2-2-2. Benefits of VVEL – Fuel Efficiency(When throttle opening is small)

Ca

m s

ha

ft F

rict

ion

Conventional Engine(fixed valve lift)

VVEL-equipped Engine(small lift amount)

VVEL-equipped engines control air amount at intake-valve by the combustion chamber entrance, which enables necessary air to be sent promptly to combustion chamber, resulting in better response.

As air is controlled at the throttle valve far from the combustion chamber, it takes time to deliver necessary air

Air instantly enters when accelerator is pressed

Conventional Engine VVEL-equipped Engine

2-2-3. Benefits of VVEL – Better Response

without VVEL

with VVEL

2-2-4. Benefits of VVEL – Better ResponseWith a short hose, water flows out right after the tap is turned (with VVEL)

2-2-5. Benefits of VVEL – Better Response

without VVEL

with VVEL

With a long hose, when the tap is turned it takes a while before water flows out (without VVEL)

VVEL

Engine Speed

Engi

ne T

orqu

e

VVEL Engine

Torque is improved by optimized valve open-close movement, adjusted accordingly to engine revolutions

2-2-6. Benefits of VVEL – More Power

Conventional Engine

At timing of ignition when air is being warmed and combustion is unstable, if valve lift amount is small, air flow velocity rises. Fuel is then atomized by vaporizing effect and combustion is stabilized, resulting in clean emissions.

2-2-7. Benefits of VVEL – Cleaner Emissions

Valve Lift 2mmAverage Particle Diameter 9 m

Valve Lift 2mmAverage Particle Diameter 9 m

Valve Lift 8mmAverage Particle Diameter 157 m

Valve Lift 8mmAverage Particle Diameter 157 m

Ben

efi

ts

Fuel Efficiency(when throttle

opening is small)

Better Response

More Power

Cleaner Emissions

VVEL

Allows necessary air to be sent promptly to the combustion chamber, resulting in better response

Torque is improved by optimized valve open-close movement, adjusted accordingly to engine revolutions

As VVEL stabilizes combustion even when engine is cool, rise in exhaust emissions temperature enables quicker warm-up of catalyst, resulting in clean emissions

2-2-8. Benefits of VVEL - Summary

VVEL is a system which controls the amount of air intake directly atthe intake-valve right before the combustion chamber

VVEL combined with C-VTC, creates continuous movement of valve

VVEL throttle valve remains open, causing little pumping loss (little resistance)

As valve lift amount is small, there is little friction

3. VVEL Structure

Valve Lifter

Valves

Rocker Arm

Control Shaft

Drive Shaft

Control Cam

Input CamLink A

Output Cam

Link B

(eccentric cam)

(eccentric cam)(oscillating cam)

DC Motor

Ball Screw Shaft Nut

Valve LifterOutput Cam

Link BRocker Arm

Control Shaft

Control Cam

Drive ShaftLink A

Input Cam

(oscillating cam)

(eccentric cam)

(eccentric cam)

3-1. Basic Structure of VVEL System

Fragmentary View (direction of arrow)Fragmentary View (direction of arrow)

DC Motor

Ball Screw Shaft Nut

3-2. Valve Lift Amount/Operating Angle Conversion

Control Shaft

Fragmentary View (direction of arrow)Fragmentary View (direction of arrow)

Output Cam (oscillating cam)

Control Shaft

Output Cam (oscillating cam)

3-3. Valve Drive of VVEL System

Drive Shaft

Valve Lifter

Valves

Drive Shaft

Valve LifterFragmentary View (direction of arrow)Fragmentary View (direction of arrow)

3-4. VVEL Motion

Maximum Valve Lift

Lift Amount

Maximum

Valve Operating Angle

Lift Amount

Maximum

Valve Operating Angle

Maximum Valve Lift Minimum Valve Lift

Lift Amount

Valve Operating Angle

Lift Amount

Minimum

Valve Operating Angle

3-4. VVEL Motion

Minimum Valve Lift

Lift Amount

Minimum

Valve Operating Angle

3-4. VVEL Motion

Minimum Valve Lift Maximum Valve Lift

VVEL is capable of continuously changing valve lift amount (between min - max) freely

3-4. VVEL Motion

4. New-Generation VQ37VHR Engine

Nissan VQ

‘95 ‘96 ‘97 ‘98 ‘99 ‘00 ‘01 ‘02 ‘03 ‘04 ‘05 ‘06

BMW I6

GM V6

Ford V8

DCX V8

Honda V6

Toyota V6

4-1 Evaluation of the VQ Engine

VQ35HR awarded “Ward’s 10 Best Engines” for 13 consecutive years

‘07

5 Best-in-class emission standard

4 Increased practical fuel efficiency

Reduced friction

Smooth, pleasant

drive

1 High rate of revolution

Max 7500rpm

4 Increased practical fuel efficiency

Reduced friction

2 Pleasant acceleration sound

Clear sound

4-2. Aim of the New Generation VQ37VHR EngineBased on the VQ35HR engine, further improvements on engine

performance, fuel efficiency, and clean emissions

3 Top level power performance in class

Improved intake/exhaust/combustion efficiencyImproved intake/exhaust/combustion efficiency

3 Top level power performance in class

5 Best-in-class emission standard

Acceleration Sound

Acceleration Sound

ResponseResponse

ExhilarationExhilaration

Fuel Efficiency

Cleaner Emissions

ResponseResponse

ExhilarationExhilaration

Fuel Efficiency

Cleaner Emissions

High ignitability for iridium plug

Revised cylinder head

Revised oil pump rotor

Increased height of cylinder blocks

Processing PVD piston ring

Straight inlet port

Asymmetric piston skirt

Revised diameter of valve

Enhanced valve spring

Hydrogen-free DLC valve lifters

Extended cylinder block liner

Enlarged diameter of crank journal

Equal length exhaust manifold

Cooling water flow structure

Twin knock sensor

Enhanced durability of chain cover

Enhanced durability of upper oil pan

Enhanced durability of lower oil pan

Enlarged diameter of crankpin

Symmetric twin intake system

Sound insulating engine cover

Enhanced durability of rocker cover

VVEL system on air intake side

High flow exhaust port

VQ37VQ37VHRVHRApprox. 35% of parts

newly developed

Thin-lined umbrella of intake valve High flow resin collector

Extended amount of valve lift

4-3. Technology of VQ37VHR EngineNew design for VQ37VHR

Ultra-wide phase angle C-VTC on intake side

Ladder frame of cam bracket

Ladder frame set

Enhanced compression ratio

M12 Spark plug

Lengthened connecting rod

High flow intake manifold

VVEL will be debut on the SKYLINE Coupe VQ37VHR engine to be launched this fall

Thank you for your attention