scholarly journals Investigation and optimization of valve train abnormal noise under idle condition

2019 ◽  
Vol 39 (4) ◽  
pp. 1127-1144
Author(s):  
Xu Zheng ◽  
Xuan Luo ◽  
Quan Zhou ◽  
Yi Qiu ◽  
Zhi-Yong Hao
Keyword(s):  
Significant Influence ◽  
Subjective Evaluation ◽  
Rotor Blades ◽  
The Other ◽  
Valve Train ◽  
Variable Valve Timing ◽  
Valve Timing ◽  
Dynamics Simulations ◽  
Variable Valve ◽  
Average Drop

This paper investigated an abnormal noise under idle condition and analyzed the mechanism of the noise based on the results of experiments and dynamics simulations. It is confirmed that knocking inside variable valve timing phaser is the source of the abnormal noise. The results of experiments show that half-order rhythm of the vibration and noise components around 1000 and 2100 Hz are different from the other dominant components, which is possible to involve the abnormal noise. Numerical analyses are conducted to simulate the process of the abnormal noise. It is found that the thickness of the blades of the variable valve timing rotor has significant influence on the abnormal noise. The simulation implies that increasing the thickness of the rotor blades will decrease the abnormal noise. When the thickness increases to 3.0 mm, the acoustic frequencies within 1000–1200 Hz have an average drop of 3.7 dB(A), and the acoustic frequencies within 2000–2200 Hz have an average drop of 12.5 dB(A). The results of verification experiments show that the amplitudes of the abnormal noise have obvious reduction, and the abnormal noise is basically eliminated under subjective evaluation.

A Multi-Cylinder HCCI Engine Model for Control

2004 ◽  
Author(s):  
Jason S. Souder ◽  
Parag Mehresh ◽  
J. Karl Hedrick ◽  
Robert W. Dibble
Keyword(s):  
Design Process ◽  
Control Design ◽  
The Other ◽  
Variable Valve Timing ◽  
Valve Timing ◽  
Coupling Effects ◽  
Hcci Engine ◽  
Engine Model ◽  
Hcci Engines ◽  
Variable Valve

Homogeneous charge compression ignition (HCCI) engines are a promising engine technology due to their low emissions and high efficiencies. Controlling the combustion timing is one of the significant challenges to practical HCCI engine implementations. In a spark-ignited engine, the combustion timing is controlled by the spark timing. In a Diesel engine, the timing of the direct fuel injection controls the combustion timing. HCCI engines lack such direct in-cylinder mechanisms. Many actuation methods for affecting the combustion timing have been proposed. These include intake air heating, variable valve timing, variable compression ratios, and exhaust throttling. On a multi-cylinder engine, the combustion timing may have to be adjusted on each cylinder independently. However, the cylinders are coupled through the intake and exhaust manifolds. For some of the proposed actuation methods, affecting the combustion timing on one cylinder influences the combustion timing of the other cylinders. In order to implement one of these actuation methods on a multi-cylinder engine, the engine controller must account for the cylinder-to-cylinder coupling effects. A multi-cylinder HCCI engine model for use in the control design process is presented. The model is comprehensive enough to capture the cylinder-to-cylinder coupling effects, yet simple enough for the rapid simulations required by the control design process. Although the model could be used for controller synthesis, the model is most useful as a starting point for generating a reduced-order model, or as a plant model for evaluating potential controllers. Specifically, the model includes the dynamics for affecting the combustion timing through exhaust throttling. The model is readily applicable to many of the other actuation methods, such as variable valve timing. Experimental results validating the model are also presented.

Design and Performance of a Variable Valve Timing System on a Highly Turbocharged Diesel Engine—Experimental and Predicted Results

1995 ◽  
Vol 209 (4) ◽  
pp. 297-311 ◽  
Author(s):  
C R Stone ◽  
H J Leonard ◽  
C Elliott ◽  
M J Newman ◽  
S J Charlton ◽  
...  
Keyword(s):  
Diesel Engine ◽  
High Speed ◽  
Reverse Flow ◽  
Valve Train ◽  
Variable Valve Timing ◽  
Valve Timing ◽  
Single Cylinder ◽  
Cycle Simulation ◽  
Timing System ◽  
Variable Valve

A previous study using a cycle simulation program had identified the possibility that highly rated diesel engines might benefit from a variable valve timing (VVT) system. In particular, the study had shown that, by delaying the start of inlet valve opening at part load, it should be possible to eliminate the reverse flow that can lead to inlet port fouling. The work reported here encompasses the design and implementation of a variable valve timing system on a highly rated high-speed marine diesel engine. The principal topics addressed are the selection and design of a mechanism, a comparison between the predictions and results from mechanism testing on a single-cylinder valve-train rig and the engine performance predictions and results obtained when the mechanism was tested on the engine. The results from the single-cylinder test rig demonstrated that the mechanism performed satisfactorily, and this led to a design suitable for retro-fitting to the engine. The engine was comprehensively instrumented and the experimental results were in good agreement with the cycle simulation predictions.

A Cam-Based Electro-Hydraulic Variable Valve Timing System for Pneumatic Hybrid Engines

2009 ◽  
Author(s):  
Mohammad Pournazeri ◽  
Amir Fazeli ◽  
Amir Khajepour
Keyword(s):  
Valve Train ◽  
Variable Valve Timing ◽  
Valve Timing ◽  
System A ◽  
Timing System ◽  
Valve Opening ◽  
And Performance ◽  
High Flexibility ◽  
Variable Valve ◽  
And Control

In this work, a new type of cam-based variable valve timing system has been proposed based on the “lost motion” principle. Using this mechanism, the problems with the valve transition time and control complexity which are still serious concerns for camless valve train systems are solved. This mechanism not only allows the engine to work at different modes of operation as an air hybrid engine but also enables it for continuous torque management. In this system, the control methodology utilizes a cam position feedback to control the valve opening timing. A combination of hydraulic and mechanical systems was utilized to offer high flexibility and robustness in the engine valve control system. A zero dimensional analysis is also conducted to evaluate the functionality and performance of the proposed system.

Application of Multi-Objective Genetic Algorithm (MOGA) for Design Optimization of Valve Timing at Various Engine Speeds

2011 ◽  
Vol 264-265 ◽  
pp. 1719-1724 ◽  
Author(s):  
A.K.M. Mohiuddin ◽  
Md. Ataur Rahman ◽  
Yap Haw Shin
Keyword(s):  
Genetic Algorithm ◽  
Design Optimization ◽  
Robust Design Optimization ◽  
Primary Concern ◽  
Variable Valve Timing ◽  
Valve Timing ◽  
Engine Valve ◽  
Multi Objective ◽  
Multi Objective Genetic Algorithm ◽  
Variable Valve

This paper aims to demonstrate the effectiveness of Multi-Objective Genetic Algorithm Optimization and its practical application on the automobile engine valve timing where the variation of performance parameters required for finest tuning to obtain the optimal engine performances. The primary concern is to acquire the clear picture of the implementation of Multi-Objective Genetic Algorithm and the essential of variable valve timing effects on the engine performances in various engine speeds. Majority of the research works in this project were in CAE software environment and method to implement optimization to 1D engine simulation. The paper conducts robust design optimization of CAMPRO 1.6L (S4PH) engine valve timing at various engine speeds using multiobjective genetic algorithm (MOGA) for the future variable valve timing (VVT) system research and development. This paper involves engine modelling in 1D software simulation environment, GT-Power. The GT-Power model is run simultaneously with mode Frontier to perform multiobjective optimization.

Development of a Hydraulic Variable Valve Timing Control System with an Optimum Angular Position Locking Mechanism

2012 ◽  
Author(s):  
Takahiro Miura ◽  
Shunichi Aoyama ◽  
Kaoru Onogawa ◽  
Takaya Fujia ◽  
Tetsuro Murata ◽  
...  
Keyword(s):  
Control System ◽  
Angular Position ◽  
Variable Valve Timing ◽  
Valve Timing ◽  
Timing Control ◽  
Locking Mechanism ◽  
Variable Valve

Study on Non-Axisymmetric 3D Curved Surface Turning by Driven-Type Rotary Tool Synchronized With Spindle

2021 ◽  
Author(s):  
Akane Ishizuka ◽  
Narimasa Ueda ◽  
Yoshitaka Morimoto ◽  
Akio Hayashi ◽  
Yoshiyuki Kaneko ◽  
...  
Keyword(s):  
Internal Combustion Engine ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Curved Surface ◽  
Variable Valve Timing ◽  
Valve Timing ◽  
Cam Mechanism ◽  
Rotary Tool ◽  
Variable Valve ◽  
New System

Abstract Since shifting to electric vehicles as a countermeasure against global warming is not always easy to complete, the hybrid car has been considered as another possible solution. However, based on the calculation of total CO2 emissions, all hybrid cars which will constitute 90% of all cars are expected to be equipped with an internal combustion engine even after 2030. Therefore, further efficiency improvement of the internal combustion engine is necessary. One of the key factors is the variable valve timing and variable lift with the 3D cam mechanism. Since conventional technology uses a complicated link mechanism and servo motor control, this leads a problem to set into small cars or motorcycles because they cannot afford to install the variable valve timing and variable lift with cam mechanism. To solve this problem, a cam shape with a three-dimensional curved surface has been proposed. In order to create this shape, the machining method for non-axisymmetric curved surface turning (NACS-Turning) is required. To build the new system, our research group has proposed a new machining method using a driven type rotary tool and a linear motor driven moving table to enable to achieve NACS-Turning. In this new system, a new tool rotation axis (B axis) is adopted to synchronize its rotational position with the rotational position of the spindle (C axis) holding the workpiece, the X1-, X2-, and Z-Axis positions in total. In this paper, the new hardware configuration is proposed to overcome the present machining accuracy.

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