梅崎 洋二

ホブ切り過渡現象の観察と切りくず生成機構の解明 : 第2報,ホブ切り過程における切りくず生成と挙動(機械要素,潤滑,工作,生産管理など)

The transient phenomenon of chip generations and behavior in hobbing are investigated by using high-speed video camera. The chip behavior in gear finish hobbing process and in hobbing of a special workpiece with one tooth space is investigated. New visual findings such as the chip interference on rake surface and the condition of contact with the work surface can be obtained. In the case of dry cutting with high-speed steel flytool having non-coated rake face, the flytool cuts the workpiece frequently as attaching on the rake face with the chip before one revolution. The newly produced chip push out the old attached chip and flies away. The now of chip is interfered strongly at the corner of cutting edge when both top and side cutting edges produces it at the same time, and flow out as changing the shape. Three chips attached on the rake face before next cutting are also observed.

ホブ切り歯車の歯面形状に関する研究 : 第2報, 送り目とホブ切り誤差および歯形誤差との関連

The feed marks on the tooth surfaces of hobbed gears express the characteristics of the tooth surfaces very well, and are related closely to the errors of hobs and hobbing machines. In this paper, the formation mechanism of feed marks caused by the errors of hobs and hobbing machines is investigated, and the relationships between the errors and the feed marks in the tooth surface configurations shown in the first report are clarified. Moreover, the relations between the feed marks and calculated tooth profile errors are investigated. From those relationships, it is possible to estimate the errors of hobs and the hobbing machine by the feed marks of hobbed gears.

ホブ切り歯車の精度向上に関する研究 : 第4報,ホブの取付け偏心の調整による被削歯車歯形精度の向上

Recent studies showed that the tooth profile errors of hobbed gears were mainly caused by the geometrical error and eccentricity error and eccentricity of the hob under good cutting conditions. Because manufacturing a highly accurate hob is very difficult and maybe a highly accurate gear is not obtained even though a highly accurate hob is used, it is very important to investigate how to improve the actual meshing accuracy of the hob in the cutting process. In general, the meshing error of the edges caused by the hob eccentricity is nearly sinusoidal and also the geometrical errors often contain sinusoidal components. On the basis of these facts, this report proposes a method which makes both of the sinusoidal error components cancel each other out in order to obtain an accurately hobbed gear. The test results clearly show its usefulness to improve the tooth profile errors of the gears.

ホブ切り歯車の精度向上に関する研究 : 第2報,解析歯形誤差と実測歯形誤差の比較および誤差要因の検討

The causes of tooth profile errors in gear hobbing are investigated by comparing the computed tooth profile errors with the measured ones, for manufacturing accurate gears. Under various hobbing conditions, gears are cut and measured. Spheroidal graphite cast iron is used as hobbed test material because built-up edge hardly occurs. From these comparisons, it is found that the tooth profile errors are mainly caused by the geometrical errors and the eccentricity of the hob. The tooth profile errors caused by the dynamic errors of the hobbing process are very small under these conditions, though they are observed more or less in the case of helical gear hobbing. It is also confirmed that the calculating method of tooth profile error, which is reported in the 1st report, is useful in analyzing gear accuracy.

ホブ切り歯車の精度向上に関する研究 : 第1報,歯形誤差形状の解析

Accurate gears are needed in order to obtain the high load carring capacity of gears. This study aims at manufacturing highly accurate gears by hobbing. In this report, a method for the calculation of tooth profile errors caused by geometrical hob errors such as profile errors of the hob tooth and the eccentricity of the hob is proposed. From the comparison of the calculated tooth profile errors with the measured ones in hobbing tests, it is found that the tooth profile errors generated by the geometrical errors and the eccentricity of the hob can be distinguished from those by the dynamic errors of the hobbing process, i.e. vibrations, built-up edges and so on. It is proved that the accuracy of this calculation method is sufficient to study the accuracy of hobbed gears.