Kinematic Analysis of Continuous Variable Valve Lift Mechanism for SI Engine

2017 ◽  
Author(s):  
Dileep Malkhede ◽  
Sudesh Jadhav ◽  
Amit Dhotre
Author(s):  
Burak Gecim ◽  
Madhusudan Raghavan

We review variable valve actuation (VVA) concepts and also present the results of our work in the creative synthesis of these devices. We begin with a comprehensive survey of existing VVA devices. We then describe our work on four VVA concepts which we have explored in considerable detail. These include hydraulic lost-motion variable-lift systems, in both the direct acting and the roller-finger-follower configurations, several valve deactivation mechanisms with unique features, a variable valve-lift mechanism, and a variable-lift and duration concept. These devices differ in their complexity and versatility but offer a spectrum of design solutions applicable to a range of products. The strengths and weaknesses of these different approaches are discussed and analyzed, and some test results are presented.


Author(s):  
Nogill Park ◽  
Jonghyeon Sohn ◽  
Gyeangmyeang Baek ◽  
Chunghan Oh

Gearing with a ZK worm and an involute helical gear is used in the motor drive system of automotive continuous variable valve lift (CVVL) because of production cost. Since the geared system does not satisfy the meshing condition, transmission error (TE) and teeth interference (TI) are inevitable. This paper introduces a method for reducing TE and eliminating TI. Transmission error function is derived mathematically and used in checking TI. The first prototype for an automobile shows a lot of NVH problem, which is simply combined by coinciding with the helix/lead angles of two gears at the pitch point. By an optimal process with alternating the pressure and helix angles of worm gear system, an prototype of CVVL worm drive of which NVH problem is acceptably solved is designed.


Author(s):  
Adrian C Clenci ◽  
Vasile Hara ◽  
Nicolae-Doru Stănescu ◽  
Adrian Bîzîiac ◽  
Rodica Niculescu

This paper presents an original continuously variable intake valve lift mechanism designed for the automotive spark ignition engines. The paper first presents the analytical kinematic synthesis of the variable intake valve lift mechanism, which consists in finding out the required intake cam profile starting from an imposed intake valve lift law. Then, by using the obtained cam profile, a computer-aided kinematic analysis of the variable intake valve lift mechanism is performed using commercial CAD software. The accuracy of the motion conversion performed with CAD software is validated by checking the degree of correlation between the resulted intake valve lift law and the imposed law used when performing the analytical synthesis. The goals of the kinematic analysis are first to find the partial laws of the intake valve lift, corresponding to the engine part loads and second, to find the transfer functions of the elements used to command the mechanism, i.e. the dependency between these elements and the intake valve lift law. The designed variable intake valve lift mechanism is successfully operated on an engine prototype and proved its energetic improvement potential.


2012 ◽  
Author(s):  
Hermes Fernandez ◽  
Youssef Kazour ◽  
Michael Knauf ◽  
James Sinnamon ◽  
Edward Suh ◽  
...  

2008 ◽  
Vol 1 (1) ◽  
pp. 1357-1365 ◽  
Author(s):  
Isato Taki ◽  
Muneaki Nakamura ◽  
Kenjiro Nakama ◽  
Kazutoshi Takahashi ◽  
Kosaku Yamauchi

Author(s):  
H. Hirani ◽  
S. Dani

A magnetorheological (MR) fluid based variable valve lift mechanism is presented. A test setup is designed to measure the frictional-torque and valve-displacement of a direct acting valve mechanism under various speed conditions. Results of valve lifts at different speeds and control currents are presented.


2008 ◽  
Author(s):  
Kazuya Kinoshita ◽  
Kazuhiko Ueda ◽  
Fumihiko Ito ◽  
Yasushi Shinojima ◽  
Takashi Yanagizawa ◽  
...  

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