Mutsumi Touge

Monitoring of wear of abrasive grains

Abstract This paper describes a simple experimental apparatus which can monitor the positions of abrasive grains and the degree of their wear under wet conditions and practical wheel peripheral speed (30 m/s). The apparatus mainly consists of a laser unit, lens, silicone-PIN-photodiode, etc. The output signal of the apparatus is investigated experimentally. The main content of the experiments are investigations for the effect of air and coolant on the output signal, variations of the output signal under different dressing conditions, a comparison of the print of wheel face and output signal, and that of normal grinding force and the area of the peak of output signal. The main results obtained from the experiments are as follows: (1) The position of peak of output signal is in good agreement with that of the wear flat of cutting edges. (2) The area of the peak corresponds to the degree of the wear flat of cutting edges.

In-process Measurement of Wear of Abrasive Grain (4th Report) - High-Speed Visualization for Wheel Working Face.

It is extremely important to know the conditions of wheel working face for managing grinding processes. Among the conditions, wear flats and their arrangements are critical because they directly have an influence on the integrity of the surface ground. However, conventional methods or apparatuses are not necessarily sufficient for measuring them as their measuring speeds or resolutions are lower than those required in practical grinding. This paper describes a system for managing grinding processes using high-speed visualization of a wheel working face at a 30m/s practical wheel peripheral speed. Images obtained by this system are almost the same quality as ones obtained by a microscope. The spatial resolution of this system is 6μm. The background, or part lower than the active cutting edges, can also be erased with a precision of about 50μm using a masking technique based on the height data of them.

Jig Grinding of Alloy Tool Steel with Electrodeposited CBN Wheels. Effects of Grinding Conditions on Grinding Characteristics.

Jig grinding is well known as a precision internal machining process for high precision products such as dies and fixtures. Investigation to realize high productivity and high accuracy is performed with different electrodeposited CBN wheels under various grinding conditions. Grinding characteristics such as grinding forces, torque and surface roughness were measured. The main results obtained are as follows. (1) Grinding accuracy improved with an increase in peripheral speed of grinding wheel. (2) Grinding forces and torque decrease with an increase in peripheral speed of wheel but increase with wheel depth of cut and work feed rate. (3) Grinding forces and torque increase with the cumulative stock removal which is caused by the progress of attritional wear of CBN abrasive grains. (4) A clear reduction of grinding forces is caused by quill motion overlapping the main axis and is induced by the decrease in the mean chip volume and/or the mean chip cross-sectional area.