Effects of end coils on the natural frequency of automotive engine valve springs

Liu, H.; Kim, D.

doi:10.1007/s12239-009-0047-8

Cited by 15 publications

(11 citation statements)

References 8 publications

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“…It has been shown in the paper (Michalczyk, 2015a) that the influence of end-coil shape can be so significant that application of the model treating a spring as a spatially curved rod, but with constant geometrical parameters over the entire length of the wire, may not produce results more accurate than the equivalent beam model, especially with regard to the first frequency of transverse vibrations. The authors of the paper (Liu and Kim, 2009) highlighted the problem of the influence of end-coil shape on the natural longitudinal vibration frequencies of valve springs, proposing a new method for calculating the first transversal frequency, based on the assumption that the torsion stiffness of end coils can be modelled by replacing them with elastic clamping of active coils.…”

Section: Analytical Model Of Helical Spring Transverse Vibrationsmentioning

confidence: 99%

A simple formula for predicting the first natural frequency of transverse vibrations of axially loaded helical springs

Michalczyk¹,

Bera²

2019

Journal of Theoretical and Applied Mechanics

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A new formula that allows the first natural frequency of transverse vibrations of axially loaded steel helical springs to be determined has been presented in the paper. The relationship is easy to use and allows finding the first natural frequency of spring vibrations without the necessity of solving analytical or numerical models. According to the authors' knowledge, this is the first such a formula and, consequently, when this frequency becomes zero, it enables determination of the critical axial force or deflection causing the buckling of the spring. The way of obtaining the described formula is presented in the paper. The results of this formula are compared with those obtained using FEM and experiments. The advantages, drawbacks and limitations of the proposed relationship are also discussed.

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Section: Analytical Model Of Helical Spring Transverse Vibrationsmentioning

confidence: 99%

A simple formula for predicting the first natural frequency of transverse vibrations of axially loaded helical springs

Michalczyk¹,

Bera²

2019

Journal of Theoretical and Applied Mechanics

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“…(4), which is an important modal parameter of vibratory feeder system. Liu et al [2] have conducted theoretical study on important parameters of the helical spring, which affects dynamic…”

Section: Mathematical Backgroundmentioning

confidence: 99%

“…It is usually suspended on the helical springs and driven by unbalanced vibratory motor. Liu and Kim [2] identified that the natural frequency of a spring changes significantly during operation under compressed condition. The natural frequency changes mostly due to the variations in the number of active coils.…”

Section: Introductionmentioning

confidence: 99%

Analysis of variations in vibration behavior of vibratory feeder due to change in stiffness of helical springs using FEM and EMA methods

Chandravanshi

Mukhopadhyay

2017

J Braz. Soc. Mech. Sci. Eng.

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“…Liu and Kim (2009) presented a paper presenting an efficient way to estimate the natural frequencies of valve springs by considering the end coil effects. The paper revealed the reason for the mismatch between the calculated and measured natural frequencies.…”

Section: Spring Surge Estimationmentioning

confidence: 99%

Estimation of valve spring surge amplitude using the variable natural frequency and the damping ratio

Liu

Kim

2011

Int.J Automot. Technol.

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Internal vibration of the valve spring is a critical factor in determining the dynamic characteristics of highspeed valve train systems. Because precise prediction of the spring surge amplitude is a difficult problem, especially for nonlinear variable-pitch springs, the development stage requires a process of trial and error. In the present study, a new method that considers the variable natural frequency and variable damping ratio is proposed to predict the spring surge amplitude. First, the change in the natural frequency and damping ratio caused by compression is predicted from the initially given pitch curve at the free height. Second, the spring surge amplitude is estimated by solving the wave equation with nonlinear variable coefficients. The surge amplitudes of typical valve springs are also measured using a motoring test rig and are compared with theoretical results predicted by the spring drawing and cam profile data. NOMENCLATURE d : spring wire diameter [mm] R : spring mean coil radius [mm] c : speed of wave propagation [m/s] k : spring stiffness [N/mm] m : mass of active coils [kg] t : time [s] x : distance along spring axis [mm] L : spring length [mm] φ : camshaft rotation angle [deg] n : order of spring natural frequency G n (φ) : dynamic component of spring internal vibration, function of camshaft angle [mm] ω n (φ) : natural frequency, function of camshaft angle [Hz] ζ (φ) : damping ratio, function of camshaft angle N α : number of active coils E : Young's modulus of spring material [Pa] G : shear modulus of spring material [Pa] ρ : density of spring material [kg/m 3 ] υ : Poisson's ratio γ : shear coefficient of wire cross section

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Effects of end coils on the natural frequency of automotive engine valve springs

Cited by 15 publications

References 8 publications

A simple formula for predicting the first natural frequency of transverse vibrations of axially loaded helical springs

A simple formula for predicting the first natural frequency of transverse vibrations of axially loaded helical springs

Analysis of variations in vibration behavior of vibratory feeder due to change in stiffness of helical springs using FEM and EMA methods

Estimation of valve spring surge amplitude using the variable natural frequency and the damping ratio

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