Performance impact of honing dynamics on surface finish of precoated cylinder bores

Abstract

International audienceThe surface modification of engine cylinder bores with improved sliding properties is often produced by the honing process. This multi-stage process is performed using abrasive stones loaded against the bore with simultaneous rotation and oscillation. To guarantee this process robustness with acceptable dimensional accuracy and surface quality, the stone dynamic effects in continuous balanced contact with the workpiece have to studied deeply. This paper highlights these effects on honed surface textures. The stone dynamic behavior was studied at conventional regime ranged from 0,5g to 1,5g as often used in mass production. In this range, the dimensional accuracy is ensured by opposition to the surface appearance. However, higher accelerations up to 2,5g improve simultaneously the form quality (especially straightness) and reduces the cycle time. This work shows, at least, that the bore surface finish can be dynamically controlled while honing. This technology is enabled by a micro scale regeneration mechanism of abrasive stones

Effect of Grain Size and Density of Abrasive on Surface Roughness, Material Removal Rate and Acoustic Emission Signal in Rough Honing Processes

“…Roughness values obtained for grain size 91 and 46 lie within the 0.05-1.6 µm range, determined by Petropoulos et al High grain size of 181 provided even higher Ra values up to 3.02 µm. Rk, Rpk, and Rvk values reported in the present paper for rough honing are higher than those found in the literature for finished honing [9,11]. This is because higher grain size is used in rough than in finish honing operations.…”

“…The regression models for the roughness parameters Ra, Rz, Rk, Rpk, Rvk, Sa, and Sz are presented in Equations (5)- (11), respectively, with their corresponding R 2 -adj value. As a general trend, roughness increases with grain size and density, as it had been found in previous experiments [38,39].…”

Flexible right sized honing technology for fast engine finishing

“…Paper [9] shows that the acceleration of inversion plays a role in the amount of horizontal traces. The prototype machine is programmed to interpolate rotation -and stroke axes in order to respect a path defined by the user.…”

“…The path is traversed with a target speed corresponding to the optimum cutting speed of the abrasive, 45 m/min. Like the experiment of article [9], the texture quality was assessed at the top and bottom of the cylinder. From the top, we can compare the quality observed in the liner with the classic honing at 458 equivalent to a conventional machine.…”

“…The study conducted in [9] showed the influence of the acceleration on the rate of non-conform grooves. The development of the prototype machine provides a way to remedy such noncompliance.…”