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Automatic transmission is now widely used equipment in vehicle to improve its performance. And determining the shift schedule is always an important problem in automatic transmission control. To shift at the properly shift point is the way to exert vehicle performance and economy. But the driving condition is very different in shift point determining, such as, throttle angle, vehicle speed, acceleration and road slope. This paper discuss the influence of the driving mass on shift point control, and the shift characteristic analysis shows why those difference occurs, and the influence of fixed shift point on vehicle performance is also discussed in the paper.

One of the most important research areas in tribology that affects the reliability, fuel economy and emissions of an internal combustion engine is the lubrication and wear of the piston ring - cylinder liner. In this paper, two-dimensional transient EHL analysis is developed for the lubrication analysis of the piston ring with the consideration of the two-dimensional deformation of the cylinder liner. The forming of the lubricant film and the characteristics of the pressure distribution on the piston ring surface are studied. The effects of the deformation of the cylinder liner are discussed. The calculated results show that the EHL performance of the piston ring significantly depends on the deformation of the cylinder liner. The paper may provide some insights for the analysis of the lubrication performance of the piston ring.

For reducing the heat rejection and enhancing the cylinder head's performance of enduring the thermal loads, the LHR cylinder head with a ceramic insulating layer is presented in this paper. The ceramic insulating layer, with the thickness of 0.0 mm, 0.7mm, 1.0mm and 1.5mm, is adopted respectively to illustrate the effect of thickness of the ceramic layer on the amount of the heat transfer of the cylinder head. Computed results show that the amount of the heat transfer decrease with the growth of the thickness of the ceramic layer. The three-dimensional FEA is used to calculate the cylinder head's mechanical-thermal comprehensive stresses. According to the FEA results, the stresses of characteristic points of the cylinder head with the heat-insulating layer become larger than those of the non-LHR cylinder head. Then, numerical analyses based on the stress-strength interference are performed to evaluate the cylinder head reliability with different thickness ceramic layer.

Free vibration of the blades of one radial-flow turbocharger is analyzed by the finite element method, and the natural frequencies and modes are obtained, the numerical results are in good agreement with the experimental ones. Resonant vibration of the compressor blade and turbine blade is analyzed respectively, then the resonance interference analysis of the blades is presented, the resonance occurrence probabilities of the blades at the rotating operation speed of the turbocharger is obtained, finally the working reliability of the blades is evaluated.

With the continuous progress of the engine technology, turbocharging technology is being developed and improved to meet more strict requirements of the fuel economy and exhaust emission of vehicle engines. At present, a very important part of the design and research of turbocharging system is to find a way to improve the transmitting efficiency of exhaust energy and turbine efficiency both in part-load and full-load power curves over the speed range. The pulsing turbocharging system widely used in the vehicle engine of low supercharging level and three-multiplied cylinders is not completely satisfactory since it is complicated in structure and difficult to keep high fuel economy in full range of running. This paper presents the scheme employing a Modular Pulse Converter (MPC) turbocharging system in the engine of low supercharging level and three-multiplied cylinders.

Affecting the normal running and determining the service lives of internal combustion engines, the lubrication and wear of the piston ring and cylinder liner pair are one of the most important area in tribology and studied both by theoretical analysis and experimental investigation by many researchers. In this paper, two-dimensional full numerical analysis is developed for the lubrication analysis of the piston ring based on the flow of lubricant. The forming of the lubricant film and the characteristics of the pressure distributions on the piston ring surface are studied. The detailed effects of many different factors, such as temperature, surface roughness, mixed lubrication and deformation of cylinder liner, are discussed. The calculating results show that the lubrication performance of piston ring significantly depends on those factors. This paper may provide some insights for the analysis of the lubrication performance of piston ring.

The Fuzzy sets theory into reliability analyses is studied. In this paper, a novel approach is presented to use the finite element analysis as a “numerical experiment” tool, and to find directly, by fuzzy linear regression method, the statistical property of the structure stress. Based on the fuzzy stress-random strength interference model proposed in this paper, the fuzzy reliability of the mechanical structure can be evaluated. The compressor blade of a given turbocharger is then introduced as a realistic example to illustrate the approach.

With the increase of strengthening degree, the parts of vehicle engines are required to bear much heavier mechanical and thermal loads. Great importance is attached to the Low Heat Rejection (LHR) technique to reduce the thermal loads and heat rejection in the field of internal combustion engines. Bearing heavy mechanical and thermal loads, cylinder heads are the most complicated parts and the key point of the LHR technique application in engines. This paper presents the researching work of the LHR cylinder head and its structure. A three-dimensional Finite Elements Analysis (FEA) of the cylinder head was offered and a large amdunt of significant data were obtained to find out the teniperatures field distribution a n d comprehensive stresses field distribution. LHR cylinder heads have greatly reduced the amount of heat rejection. This paper may provide some insights for the LHR cylinder head's designs.