| 摘要 |
A variable venturi down-draft carburettor comprises a unitary casting (1) which defines an induction passage (2), and upwardly open cavities constituting a float chamber and a recess in which a movable venturi member (15) is housed. A throttle valve (30), main jets (12,13) and venturi members (15) are all housed wholly within the confines of the casting (1), and the casting is covered by a single plate (40) which closes the upwardly open cavities and defines an inlet orifice (41) to the induction passage (2). By housing the throttle valve (30), main jets (12,13) and venturi in one unit operation of the carburettor is unaffected by variations in the cover plate (40) produced by manufacturing tolerances. Access to the interior of the carburettor is achieved by removal of the plate (40) which does not, in itself, affect the adjustment of the carburettor. The casting preferably includes integral mountings for a vacuum motor, and/or acceleration pump, and/or an automatic choke. |
