Honing

About: Honing is a research topic. Over the lifetime, 3530 publications have been published within this topic receiving 17491 citations.

Reducing in-cylinder parasitic losses through surface modification and coating

Abstract: Friction constitutes nearly one fifth of all engine losses. The main contributory source of frictional losses in most engines is the piston–cylinder system, accounting for nearly half of all the parasitic losses. Minimisation of this is essential for improved fuel efficiency and reduced emissions, which are the main driving forces in engine development. The tribology of piston–cylinder conjunctions is, however, transient in nature. This means that various palliative actions need to be undertaken to suit certain instances during the engine cycle. In general, formation of a coherent film of lubricant of suitable viscosity reduces the chance of boundary interactions for most of the piston cycle. Plateau honing of the cylinder bore surface reduces the ‘peakiness’ of the surface topography. Furthermore, if regularly spaced grooves are provided on the contacting surface, these grooves can act as reservoirs of lubricant. However, at low sliding speeds, which are typically found during piston motion reversals, lubricant entrainment into the contact either ceases or is significantly reduced. Therefore, at the end of the piston strokes, there is a greater chance of boundary interactions, resulting in increased friction. There is a need to engineer the surface topography in these low-relative-speed regions in a manner conducive to the retention of a lubricant film. Surface texturing by means of laser processing or mechanical indentation at the dead centres are used to produce local reservoirs of lubricant as well as to encourage and direct the flow of lubricant into the contact conjunction. The paper shows that such surface-modifying features improve the engine’s output power by as much as 4% over that of the standard cylinder bore surface. To reduce wear and scuffing, particularly at the top dead centre, hard coatings can also be used. However, smooth surfaces and the generally oleophobic nature of hard coatings can increase the chance of adhesion, particularly at low sliding speeds. This means that prevention of wear does not necessarily lead to improved fuel efficiency. Furthermore, it is necessary to determine the geometry of the textured patterns in order to avoid the leakage of oil from the ring-pack conjunctions, which can result in increased emissions as well as lubricant degradation and depletion.

Stone polishing apparatus and method

Abstract: A self-propelled battery operated stone floor polishing machine having dual rotating heads with detachable stone grinding, honing, and polishing pads. The polishing machine includes an integral solution tank for applying a liquid lubrication to the floor through the heads, a recovery tank for collecting the slurry generated by the grinding, honing, and polishing action, and an integral squeegee system that removes the liquid and particle slurry and thereafter transfers the slurry to the recovery tank. The grinding pads are integrated with metallic alloys, bonding industrial diamond abrasives for grinding marble, granite, poured terrazzo, precast terrazzo, cement, concrete, porcelain tile, ceramic tile, teracotta tile, but are not limited to these stone surfaces. A single operator may grind, hone, and polish up to 1,500 square feet of stone floors in a normal work day.

Applied Machining Technology

Abstract: Fundamentals of machining explained for turning.- Tool life T.- Tool- and machine curves.- Metal removal rate and chip volume ratio.- Cutting materials.- Turning.- Planning and slotting.- Drilling.- Sawing.- Milling.- Broaching.- Grinding.- Abrasive cutting.- Abrasive belt grinding.- Honing.- Superfinishing (shortstroke honing).- Lapping.- Further refinement of the cutting materials.- High speed cutting (HSC).- Cutting fluids (coolants and lubricants).- Cutting force measurement in machining.- Tables for general use.