Vertical Feed Research Articles

円筒形状誤差の一解析法

A method for analyzing and evaluating form errors of cylindrical parts is investigated. The profile of a cylindrical test piece is measured at several sections along the axis under the same setting on the rotating table of a roundness measuring machine which has an accurate vertical feed of the detector. An orthogonal function consisting of Fourier series and orthogonal polynomials is fitted to the observed data in cylindrical coordinates sampled at every 7.5 degrees for each section of the test piece. Geometrical meanings of individual terms of the orthogonal function are disclosed. By dissolving the total sum of squares of the observations into parts corresponding to individual terms and testing their significances against the residual variance, the form erorrs of the test piece as well as the errors in measurement are assessed independently of the setting conditions. The method is applied for measuring form errors in a few plug gauges and cylindrical machine parts.

On the Selection of the Cutting Condition of Plain Milling Machines

We analized the process involving self-excited vibration of the plain milling machine and tried to select the stable cutting condition by the simulation with analog computer. As the process involving self-excited vibration, a vibrating system of two directinos of vertical and table feed was considered and a system diagram based on regenerative effect was described. Then, the simulation circuit was composed on the analog computer using an equivalent vibrating system of the plain milling machine which was derived from the frequency response curve. The result coincided with the two kinds of self-excited vibrations at different frequencies caused in cutting experiment and with the stability diagram. As a result, using the analog computer as a simulator, it was made possible to select the best cutting condition never accompanied by self-excited vibrations.

研削砥石の摩耗の一般的特性

The characteristics in wear of grinding wheels are investigated over an ordinary range of grinding conditions. Further, the size distribution of abrasive grains worn from a grinding wheel is measured. Experimental results reveal the rapid increase of wear as the grinding condition is brought severe. The size distribution, however, does not change remarkably throughout the experiments.The effect of the grinding condition on wear is discussed in terms of the life of an active grain. The discussion leads to the conclusion that the life of a grain involves only a parameter, that is, the grain depth of cut which varies with the work speed and the vertical feed.

Canine Cysticercosis

Mechanical feed mixers are preferred for their higher efficiencies. A wide range of these feed mixers are available and used in the Ashanti and Brong Ahafo regions of Ghana due to a higher concentration of poultry farms in these regions. The performances of both local and foreign poultry feed mixers in the two regions were evaluated. This was carried out as a procedure to identify the types, measure machine parameters, operational parameters and feed characteristics relevant to the performance of poultry feed mixers. Data collected were analysed using statistical tools at 95% C.I. From the results, moisture content of the feed samples ranged from 9.21 to 11.08% (% wb), the geometric mean diameter of all samples ranged from 762.74 to 947.27 µm with the geometric standard deviation range of 2.35–2.50. The two dominating feed mixer types were the horizontal and vertical. The horizontal feed mixers indicated mixing time of 1.5–10 min, mixing speed of 40–80 rpm, energy consumption per mix of 0.9–3.8 kWh and blending uniformity with a coefficient of variation (CV = 7.19%), but relatively high maintenance cost per month. CV less than 10% is the percent commonly recognized by the feed industry as the cut-off for uniformity of mix analysis. The vertical feed mixers indicated low maintenance cost, mixing time of 15–30 min, mixing speed of 250–500 rpm, energy consumption per mix of 0.8–5.5 kWh and CV = 10.30–18.05%. Given that the horizontal feed mixers were found to have better performance metrics, there is the need to adapt the design for local process planning and manufacture, while substituting imported machine parts and components with locally available materials to optimize performance and minimise maintenance cost for the poultry and feed industries.