ABSTRACT
The cylinder head gasket (CHG) joint is the most critical sealing joint for IC engine performance. Cylinder head bolt preload application should be stoichiometric. Excess cylinder head bolt pre-tension develops more stress and further leads to bore deformation. Insufficient cylinder head bolt pre-tension leads to gasket leakage. It is challenging to achieve uniform pressure distribution because of variation in stiffness of block and head. But the minimum pressure must be ensured for leak-proof joint. In this article, gasket pressure distribution around the cylinder bore is estimated by non-linear Finite Element Analysis (FEA) and compared with Fuji Film results. Bore deformations, due to spiral and cross patterns, are determined and compared. Piston ring conformability is estimated in terms of percentage sealing of the ring to the liner. Effects of bolt tightening strategies are investigated for engine gasket sealing parameter, bore deformation and piston ring conformability.
Nomenclature
ɣ = | = | interpenetration between the two contacting bodies in terms of displacement |
p = | = | normal traction |
Г = | = | interface between the contacting bodies over which the penalty term is integrated |
fc = | = | contact force |
vT = | = | normal velocity |
fint = | = | internal forces |
fext = | = | external forces |
Ma = | = | inertial forces |
Δr = | = | deviation from ideal circle |
N = | = | number of nodes per level |
An and Bn = | = | Fourier coefficients of nth order |
Cn = | = | Magnitude of nth order harmonic |
αn = | = | Angle of nth order harmonic |
k = | = | conformability coefficient |
Ft = | = | tangential load |
D = | = | nominal diameter of ring |
E = | = | modulus of elasticity |
J = | = | moment of inertia of the ring cross section |
Umax = | = | ring conformability |
k = | = | Conformability coefficient |
I = | = | Order of deformation (2, 3….) |
r = | = | Radius of ring |
ub = | = | maximum deformation |
Acknowledgments
I would like to thank my colleague in Powertrain engineering department of, The Automotive Research Association of India (ARAI) & VIT University who has given support for carrying out above work.
Disclosure statement
No potential conflict of interest was reported by the authors.