THROTTLE VALVE

摘要

A throttle valve (10) disposed in a cylindrical bore (2) so as to cross the center axis of the bore and supported rotatably by a throttle shaft passing through the bore, wherein a bitten zone (10a) (diagonally shaded area) on the external surface of the throttle valve (10) near the area crossing the throttle shaft is removed by cutting so as to avoid an interference with the bore (2), and the maximum value delta max of a recess is shown by the expression (2); instead of forming such a recess, height differences (20b) and (20c) may be formed as shown in Fig. 3 or a thick wall part (30b) may be formed as shown in Fig. 4, whereby an increase in intake air volume at the time when the valve is fully closed and in a small opening area of the valve can be suppressed.