Contact force prediction and experimental verification on an OHC finger-follower-type cam-valuve system

Kim, Wj; Jeon, Hs; Park, Youn-sik

doi:10.1007/bf02327568

Cited by 10 publications

(8 citation statements)

References 5 publications

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“…A combined kinematic analysis of the mechanism with lubricated contact dynamics is then justified, as in the works reported in references [7,8,19,20]. However, at progressively increasing engine speeds, the spring surge effect becomes significant as shown by Kim et al [21], and thus a full non-linear dynamic analysis becomes necessary. At higher speeds, larger dynamic forces occur, yielding higher contact forces that can be quite beneficial as highlighted above.…”

Section: Resultsmentioning

confidence: 97%

Valve-train dynamics: A simplified tribo-elasto-multi-body analysis

Kushwaha

Rahnejat

Jin

2000

Proceedings of the Institution of Mechanical Engineers, Part K:

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This paper presents a model of a cycloidal cam-flat follower pair. The model incorporates the inertial elements, the assembly constraint functions and the sources of compliance in the valve train. The sources of compliance include the valve spring characteristics, including the spring surge effect under dynamic conditions, as well as the contact compliance between the cam and the flat follower. The contact domain is treated as a counterformal concentrated lubricated region subjected to an elastohydrodynamic regime of lubrication (EHL). The prevailing contact geometry is one of finite line contact.The paper presents the results of simultaneous solution of the Lagrangian dynamics for the non-linear constrained system, together with an approximate quasi-static elastohydrodynamic solution of the lubricated contact conjunction at each time step by an extrapolated oil-film thickness formula for combined entraining and squeeze film action. The effect of spring surge on the contact separation and residual vibrations of the system are investigated, as well as the lubricant pressure distribution and film thickness, including during start-up and acceleration.

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Section: Resultsmentioning

confidence: 97%

Valve-train dynamics: A simplified tribo-elasto-multi-body analysis

Kushwaha

Rahnejat

Jin

2000

Proceedings of the Institution of Mechanical Engineers, Part K:

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“…He observed that profile errors can have a major impact on the dynamic performance of such high-speed follower cam systems. Kim et al (1991) used a lumped mass-springdamper to predict the dynamic behaviour of a cam-valve system that gives concordant results compared with experimental tests for the evaluation of contact forces in the system. Jeon et al (1989) stated in his paper that with experimental and simulation results that optimize a cam profile, he is able to increase the valve lift area, while reducing the cam acceleration and the peak pushrod force.…”

Section: State Of the Artmentioning

confidence: 99%

Computational Tool for Simulation of the Dynamic Response of Valve Train

Osman¹

2014

IJTTE

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This paper presents the development of the MOTORI 2004 computing tool that calculates the distance, speed and acceleration of a car engine valve train's oscillating mass m, which is reduced to the valve axis. Distance diagrams, speed and accelerations are provided in dependence on the camshaft twist angle at a constant rotational speed in several consecutive revolutions. The computing tool implements a mathematical description and numerical solution for the motion of mass m of a valve gear dynamic model. Valve lift h is given numerically using a series of equidistant points in the period of one camshaft revolution. The variabilities of camshaft rotation and spring thread vibration as a result of cam lift harmonic excitation. The computing solutions were tested at valve opening points and in imaginary extreme operating conditions (soft/hard spring, low/high damping, low/high rotational speed and increased clearance.

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“…Three types of geometric tolerances exist: (1 ) cam profile tolerance (and finger follower profile tolerance); (2) cam eccentricity tolerance; and (3) perpendicularity tolerance of the valve stem. The corresponding dynamic model [10] and an interpretation of the geometric tolerance types are shown. The overall functional design requirements of this mechanism can be Figure 2.…”

Section: Sources Of Noisementioning

confidence: 99%

“…The overall functional design requirements of this mechanism can be Figure 2. A finger follower-type cam valve system [10], dynamic model, and geometnc tolerances. stated in terms of the functions performed by each component (sub-system).…”

Section: Sources Of Noisementioning

confidence: 99%

A Concurrent Engineering Approach To Robust Product Design

Gadallah

ElMaraghy

1993

Concurrent Engineering

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An approach for robust design of mechanical systems using experimental design techniques is presented. Performance and achievement of functional requirements depend critically on variations on the geometry, dimensions, and positions of the system components. These variations arise due to limitations imposed by the capabilities of manufacturing processes, the tight control of which can be prohibitively expensive. This paper presents an approach for achieving robust designs which are less sensitive to these variations. Two formulations are used where manufacturing tolerances are considered as: (1) control variables; and (2) noise variables beyond the designer's control. Orthogonal arrays and analysis of variance are used to detect the most important design parameters to ensure performance robustness. The proposed design methodology is illustrated using a finger follower cam valve system. A comparison with other conventional design approaches is included.

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Contact force prediction and experimental verification on an OHC finger-follower-type cam-valuve system

Cited by 10 publications

References 5 publications

Valve-train dynamics: A simplified tribo-elasto-multi-body analysis

Valve-train dynamics: A simplified tribo-elasto-multi-body analysis

Computational Tool for Simulation of the Dynamic Response of Valve Train

A Concurrent Engineering Approach To Robust Product Design

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