throttle body led to evolutionary form of a rating of its axis and butterfly evolutionary form of complementary dimension

A throttle valve body (1) including a flap (6) of which the side pivoting down or up on opening has a shoulder (17) on the flap surface facing upwards or downwards, respectively, defining a gradually widening cross-sectional area with the cylindrical (7) or frusto-conical (9) wall opposite the intake channel (3) through the housing (2). The side of the flap (6) which rotates up or down, respectively, on opening consists of a flat half disk of which the edge is moved, at first, opposite a tapered surface portion (14) with a complex shape to define a gradually widening cross-sectional area downstream from an inlet convergent (15, 12) and upstream from an outlet divergent, respectively. Said throttle valve body may be used in an internal combustion engine injection device.