Maximum Roughness Height Research Articles

Some Ecological Notes on the Egg Deposition of Argulus coregoni THORELL (Crustacea, Branchiura)

Laboratory and field experiments were made to examine the effects of time of day, water depth, and roughness of substrata on the egg deposition of Argulus coregoni. Egg-laying occurred normally at night (98%, 93/95) ; however, mature females laid eggs even in the daytime under experimentally dark conditions. The oviposition was thus considered to be influenced by the absence of light.The relationship between water depth and egg deposition was examined in trout ponds of 65 cm and 140 cm deep by hanging acrylic plates as substrata for the egg deposition, and the clusters of eggs deposited on the plates were analyzed. The clusters were found to be more abundant nearer the bottom of both ponds : 88% of the total number of clusters deposited at a depth of 45-65 cm in the pond of 65 cm depth and 74% at a depth of 100-140 cm in the 140 cm-deep pond.The parasite showed a preference of roughness of substrata. Only a few egg clusters were deposited on transparent glass (smooth substratum of less than 0.5 μm maximum height of roughness) and on a wooden plate (rough substratum of more than 50 μm), whereas abundant egg clusters were found on frosted glass or unglazed tile with a roughness of about 9 μm.Methods of control of A. coregoni utilizing these results are also discussed.

有効砥石深さと有効切れ刃分布の測定

Optical methods of measuring effective wheel depth and distribution of effective cutting edges by use of the apparatus, of which constitution was described in the previous paper, are presented. They are measured in dry surface grinding with variations of wheel depth of cut and dressing condition. The effective wheel depth increases not only with wheel depth of cut, but also with dresser feed or sharpness of the dresser point. Near the surface of wheel, there is a decrease of density of the effective cutting edges toward inside, being followed by an almost constant region up to the effective wheel depth. For higher dresser feed, the decrease is not conspicuous and the distribution becomes more uniform. The relation between maximum valley height of ground surface roughness and effective wheel depth is examined based upon the obtained distribution of the effective cutting edges.

放電研摩に関する研究(第3報)

Experimental studies are carried out on the following points to clarify the properties of surface machined by electric discharge grinding ; roughness, hardness and wear resistance of pure iron, mild steel, S45C steel, SKH steel and sintered carbide alloy. Life test of discharge grinding carbide tool is also investigated.The following conclusions are obtained :(1) Surface roughness increases as electrostatic capacity of condenser increases and is independent to the discharge-frequency per unit time within the range investigated.(2) Hardness of discharge grinding surface layer increases because of work-hardening or change of structure of metallic surface.(3) Wear rate of discharge grinding SKH steel surface is one-half of that of the mechanical grinding surface. Wear rate of sintered carbide alloy machined by electric discharge grinding has the same degree as by diamond grinding wheel.(4) Tool life of carbide tool machined by electric discharge grinding becomes long because the mechanical property of the surface layer of a carbide tip is improved. Face, frank and cutting edge of carbide tool machined by electric discharge grinding have a maximum height roughness of 1.5 microns.

表面あらさと負荷曲線

The relation between the surface roughness and Abbott's bearing curve is examined by introducing a model of the profile curves of some finished surfaces. Profile curves of almost all kinds of finished surfaces, except such special surfaces as milled ones and turned ones by a round nose tool, can be assumed to be made up of a series of triangles, the height of which is nearly equal with each other. In these cases the bearing curve can be drawn as a main straight line with broken lines at either end of it, and the broken lines disappear when the peaks and the valleys of the cross sectional curve are on two straight lines parallel to the center line of the cross sectional curve. The existence of the broken line has a secondary effect on the estimation of the center line average roughness, while it has important effect on the estimation of the maximum height roughness. Hence the center line average roughness can easily be calculated graphically, neglecting the broken lines of the bearing curve.It is found that the above theory can be applied for the surfaces which are finished by abrasive grains, that is, by emery cloth, abrasive belt, grinding wheel and sand blasting.

寸法測定値におよぼす表面あらさの影響(第2報)

In this report accuracy of length measurement relating to the mechanical contact between spherical surface of feeler and the test piece is discussed.In order to make clear these relations, displacement of a lapped disc tracing on the specimen is recorded by a roughness meter. And one more factor "reducing factor" is added to the profile factor suggested in the previous paper. The reducing factor means a ratio of the maximum height of the recorded envelope curve to the maximum height of the surface roughness. Introducing the reducing factor, reasonable length and distribution of the measured values can be known when measuring force and radius of curvature of the feeler and material of the test specimen are given.And further the authors suggest that the radius of curvature of the spherical surface of skid used for recording envelope curve of the surface is more than about four thousands times the maximum height of surface roughness.

不銹鋼の鏡面仕上について

The most efficient polishing methods of stainless steel to get smooth mirror-finished surface from rough turned surface of 20 μ maximum height roughness are researched. The polishing procedures are divided into two stages, namely "superfinishing" with abrasive stone of vitrified bond in the first stage and " superlapping " with chromium-oxide and felt lap in the second stage, in which the lap is oscillated just like in superfinishing. Also, these experimental results of the stainless steel are compared to the results obtained about the carbon steel of same hardness.