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The purpose of this paper is to investigate the influence of different finish processes on the surface integrity and tribological behaviour of cylinder running surfaces…
The purpose of this paper is to investigate the influence of different finish processes on the surface integrity and tribological behaviour of cylinder running surfaces for internal combustion engines.
The cutting force during finishing and the resulting surface topography was measured for a variety of cylinder running surfaces made of EN-GJL-250, EN-GJV-400 and thermal sprayed aluminium alloy. A separate conditioning tool was developed and tested. Different analysis methods (SEM, EDX, SIMS and FIB) for the characterisation of the boundary conditions were used. By an oscillating friction wear test and a single cylinder floating liner engine, the running-in and frictional behaviour was rated.
It was shown that honing with low cutting forces and silicon carbide cutting material decreases the friction in operation. The characteristics of the boundary layers after running-in depend on the finish machining process. A preconditioning with a separate tool can adjust the boundary layer and running-in behaviour. Based on the experimental results, a multi-body and computational fluid dynamics simulation was developed for the floating liner engine.
The results demonstrate the potential of finishing with low process forces to reduce friction and the need for a complete consideration of the tribological system piston ring/cylinder liner surface.
This paper proposes a classification scheme for the quantified analysis of micro‐grip principles. Micro‐part gripping has received quite some attention in micro‐assembly…
This paper proposes a classification scheme for the quantified analysis of micro‐grip principles. Micro‐part gripping has received quite some attention in micro‐assembly research. However, there is a lack of quantified data on the characteristics and applicability of micro‐grip principles. The micro‐grip principle is the physical principle that produces the necessary forces to get and maintain a part in a position with respect to the gripper. The classification scheme defines criteria that are essential in the evaluation and selection of a micro‐grip principle for gripping a given part. The criteria are defined on the basis of characteristics of the parts to be gripped, demands on the grip operation to be performed and characteristics of the environment in which the grip operation takes place. The classification scheme is evaluated using examples from literature.
An alternative way of performing micro‐assembly tasks is by means of product‐internal assembly functions. After a coarse alignment step, the parts are fine positioned…
An alternative way of performing micro‐assembly tasks is by means of product‐internal assembly functions. After a coarse alignment step, the parts are fine positioned relative to each other by functionality that is integrated with the product. This functionality includes part actuation, position sensing and part freezing. They replace expensive machinery and delicate manual labour, and are aimed to result in lower total production costs. Micro electro mechanical system (MEMS) technology has important benefits to be used as supporting technology, because it allows for cost reduction (batch production), and structures can be made with small dimensions and high accuracy. The objective of this paper is to develop a reliable and reproducible interconnection technology using MEMS‐based product‐internal assembly functions, by which packaging cost is reduced and yield is improved. The considered case is the packaging of optical fibre to chip couplings.