Increasing Torque Output from a Turbodiesel with Camless Valvetrain

Tai, Chun; Tsao, Tsu‐Chin; Schorn, N.; Levin, Michael

doi:10.4271/2002-01-1108

Cited by 18 publications

(4 citation statements)

References 2 publications

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“…With its gaseous state, low density, and, thus, large volume, the electronic control of air exchange was a slow evolution process, from variable valve time (VVT) to more sophisticated systems such as discrete variable valve lift (DVVL), continuous variable valve lift (CVVL), cam-based variable valve actuation (VVA), and camless VVA, which are reviewed later in this article. There were also efforts to develop camless VVA to have complete electronic control of the air exchange process, which is a major enabler for advanced combustion such as homogeneous charge compression ignition (HCCI) to improve engine fuel economy and reduce emissions [4][5][6][7]. To improve engine fuel economy, engine downsizing techniques are widely used with the help of turbochargers.…”

Section: Combustion and Need For Electronic Control Of Gas Exchangementioning

confidence: 99%

Review of Advancement in Variable Valve Actuation of Internal Combustion Engines

Lou

Zhu

2020

Applied Sciences

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The increasing concerns of air pollution and energy usage led to the electrification of the vehicle powertrain system in recent years. On the other hand, internal combustion engines were the dominant vehicle power source for more than a century, and they will continue to be used in most vehicles for decades to come; thus, it is necessary to employ advanced technologies to replace traditional mechanical systems with mechatronic systems to meet the ever-increasing demand of continuously improving engine efficiency with reduced emissions, where engine intake and the exhaust valve system represent key subsystems that affect the engine combustion efficiency and emissions. This paper reviews variable engine valve systems, including hydraulic and electrical variable valve timing systems, hydraulic multistep lift systems, continuously variable lift and timing valve systems, lost-motion systems, and electro-magnetic, electro-hydraulic, and electro-pneumatic variable valve actuation systems.

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Section: Combustion and Need For Electronic Control Of Gas Exchangementioning

confidence: 99%

Review of Advancement in Variable Valve Actuation of Internal Combustion Engines

Lou

Zhu

2020

Applied Sciences

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“…Nevin et al achieved PCCI using VVT and claimed that nearly 70% CO and PM levels could be decreased by late inlet valve closing [4]. Tai et al investigated a 2.7 L light duty diesel engine on the effects of inlet valve closing and exhaust valve openings [5]. Charlton et al investigated a turbocharged 39.42 L diesel engine using computer simulation and claimed that increasing the valve overlap as soon as possible would obtain optimum transient response [6].…”

Section: Introductionmentioning

confidence: 99%

13 Mode Fuel Benefit Investigation Using Variable Valve Timing in a Heavy Duty Diesel Engine

Deng

Stobart

2009

2009 Asia-Pacific Power and Energy Engineering Conference

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Variable valve actuation in heavy duty diesel engines is not well documented, partly because of diesel engine nature, such as, unthrottled air handling, which gives little room to improve pumping loss; a very high compression ratio, which makes the clearance between the piston and valve is little when the piston reaches the top dead center. It is a long time that diesel engines are running by EGR and VGT. The goal of this research work is addressed the issue about how much fuel benefit diesel engines at 13-mode cycle could be achieved using variable valve timing in a heavy duty diesel engine. Late inlet valve closing strategy will be used. In order to see how much fuel efficiency could improve in addition to EGR and VGT, EGR and VGT are fully controlled in a closed-loop. This paper examines fuel improvement in different speeds and torques. Finally, we could see that 3.28% BSFC benefit at 13-mode cycle could be achieved. The reason of this benefit is that fixed valve lift engine makes a compromise between high speed engine performance and low speed fuel economy, late inlet valve closing optimizes valve timing at each engine torque and speed.

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“…For traditional internal combustion engines, engine intake and exhaust valves operate with a fixed lift and timing and some valve systems are capable of dual-lift and variable valve timing [1,2,3]. Engines with Variable Valve Actuation (VVA) systems are capable of continuously variable lift and timing at any given operational condition to minimize the engine pumping loss with optimized combustion to improve engine performances in fuel economy, emissions, and torque delivery [4,5,6].…”

Section: Introductionmentioning

confidence: 99%

Progress in Camless Variable Valve Actuation with Two-Spring Pendulum and Electrohydraulic Latching

Lou¹,

Deng²,

Wen³

et al. 2013

SAE Int. J. Engines

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Camless Variable Valve Actuation (VVA) technologies have been known for improving fuel economy, reducing emissions, and enhancing engine performance. VVA can be divided into electromagnetic , electro-hydraulic, and electropneumatic actuation. A family of camless VVA designs (called LGD-VVA or Gongda-VVA) has been presented in an earlier SAE publication (SAE 2007-01-1295) that consists of a two-spring actuation, a bypass passage, and an electrohydraulic latch-release mechanism. The two-spring pendulum system is used to provide efficient conversion between the moving mass kinetic energy and the spring potential energy for reduced energy consumption and to be more robust to the operational temperature than the conventional electrohydraulic actuation; and the electrohydraulic mechanism is intended for latch-release function, energy compensation and seating velocity control. This paper presents the prototype design of a variable valve-time and two-lift LGD-VVA with bench and engine test results. The designed actuator is able to achieve 3 ms opening and closing response time with satisfactory valve seating velocity and low energy consumption. This is all achieved with a cost-effective design and open-loop control.

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Increasing Torque Output from a Turbodiesel with Camless Valvetrain

Cited by 18 publications

References 2 publications

Review of Advancement in Variable Valve Actuation of Internal Combustion Engines

Review of Advancement in Variable Valve Actuation of Internal Combustion Engines

13 Mode Fuel Benefit Investigation Using Variable Valve Timing in a Heavy Duty Diesel Engine

Progress in Camless Variable Valve Actuation with Two-Spring Pendulum and Electrohydraulic Latching

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