Papers by Keyword: Ground Surface Roughness

Abstract: Roughness is important criterion of ground surface. When the surface roughness is demanded to be smooth, it is required to make the grinding conditions optimum. To optimize the grinding conditions, relationship between grinding conditions and ground surface roughness must be known. Therefore, it has been attempted to reveal the effect of grinding conditions on the roughness of ground surface over the years. From previous researches, it becomes possible to estimate the ground surface roughness with statistical grinding theory. However, there are some parameters, such as wheel depth of cut and distribution of abrasive grain, are not factored in the theory. In this paper, fundamental research on cross sectional profile is carried out to consider the relationship between the wheel depth of cut and ground surface roughness.

Abstract: A cutting-tool-type single-point diamond dresser, the tip of which has a given rake angle, was developed and its dressing and grinding performances were investigated. It was found that the dressing mechanism changes its mode from a ductile mode to a brittle mode with increasing back rake angle in the negative direction and that the cutting-tool-type dresser exhibits good robustness owing to the fact that its ground surface roughness is not markedly affected by the dressing conditions.

Abstract: Micro-grinding is a machining method to create submillimeter structures, and it can be applicable to various kinds of materials with a flexible forming ability. However, the micro tool may be easily bended by the grinding force, which results in relative low form accuracy and worse ground surface roughness. To solve these problems, ultrasonic assistance was applied to micro-grinding. This paper proposes a method to calculate ground surface roughness theoretically using statistical approach, and the ground surface improving mechanism of ultrasonic assistance was clarified. Finally, the theoretical calculation was confirmed experimentally using a developed ultrasonic-assisted micro-grinding device.

Abstract: In this study, the determination method of the number of the effective cutting-edges had been proposed based on the measurements of working surface topography and the grinding force. Furthermore, its validity is made clear based on the topographical analysis of the ground surface roughness of pure copper, which is excellent in transcribing the working surface. From the results, the following are found out: The ground surface topography contains the periodical component, which is originated in the grinding and dressing conditions, on the fractal noise component. The cutting traces by each cutting-edge can be countable from the ground surface profile, and then, the number of the effective cutting-edges is identified at one line within the working surface. On the other hand, the number of the effective cutting-edges also can be identified based on the working surface, but, this method requires the determination of the typical grain shape. From the experiment, it is confirmed that the grain shape should be almost spherical for making the numbers of the effective cutting-edge identified from the working and ground surfaces equal.

Abstract: The grinding should be improved to be the skill-free process executed based on the quantified criteria. In this study, the evaluation methods are applied to evaluate the dressing process to clarify how the dressing changes the cutting-edge distribution. From the results, the following facts have been clarified: There is the critical value of the depth of cut for suppressing the release of grain. The spark-out in dressing releases grains damaged by collision with dresser, and then, it also increases the cutting-edge density.

Abstract: Dressing force measuring equipment was developed and the performance of a single-point diamond dresser was examined focusing on the relationship between dressing force and grinding performance. It was found that a distinct relationship exists between dressing force and grinding performance, and that the sharp-edged single-point diamond dresser can control grinding performance with low dressing force. The single-point diamond dresser and multipoint diamond rotary dresser induce the same dressing force if their wear widths are equal.

Abstract: The effect of cutting-edge truncation on the grinding mechanism of quartz glass as a hard and brittle material was investigated. From computer-aided grinding simulations and experiments on surface plunge grinding it was found that cutting-edge truncation decreases the ground-surface roughness and the maximum grain depth of cut; however, the maximum grain depth of cut approaches a constant value depending on the grinding wheel specifications. The alternative means of making the maximum grain depth of cut much smaller than this constant value is to increase the speed ratio. Cutting-edge truncation should be terminated at the optimum truncation depth to avoid the high grinding forces resulting from the flattening of cutting edges.

Abstract: Aiming at different ground surfaces of hardened bearing steel GCr15, this paper made experimental research on assessment method of surface roughness based on computer vision technology. Firstly, some pre-processing of the ground images should be carried out to eliminate noise and get more detail information, including image enhancement and median filtering. Then the method of power spectrum analysis transformed representation of processed image from spatial domain to frequency domain by adopting two-dimensional Discrete Fourier Transform. Gaining the mean power spectrum named E and its corresponding radius r, we made efforts to seek the direction in which the arithmetic average surface roughness Ra varied according to E and r. After that the variation rule can be regarded as an assessment basis of ground surface roughness.