| 摘要 |
Fuel-air mixture apparatus (1) has a body (2) adapted for connection via a flange (3) to an air cleaner housing (3') and to an engine inlet manifold (4'). In the body (2) is arranged a primary air passage (5) having an inlet (6), an adjustable throttle (7), a throat (8) and an outlet (9). The throttle will be connected in use to a speed control device for the engine via a linkage (10). Also provided in the body (2) is a secondary air passage (13) having an inlet (14) from the air cleaner housing and an outlet (15) to the primary air passage (5) at the throat (8). Towards its downstream end, the secondary air passage opens into a chamber (16), with the opening (17) being arranged tangentially to the chamber to induce swirling air flow in the chamber. The outlet (11) is provided axially of the chamber. At the other end of the chamber, in a bore (18) in the body a nozzle device (21) is provided. It has a circumferential void (24) to the body. This void has a fuel supply bore (25) in the body (2) and connected to a continuous fuel pump opening into it. A fuel inlet (26) leads from the void to an internal bore in the sleeve (22). Slidably mounted in the sleeve is a guide (27), sealed to the sleeve via a gland (28). The outside end of the guide carries a compression spring (29) and the end of the guide is closed by a plug (30) providing an abutment for the spring, whereby the guide is urged outwards. The guide has a bore (31) in which a needle (32) is slidably mounted. The arrangement is such that when the plug (30) is pushed fully inwards of the body, as on closure of the throttle, the needle closes the aperture (38) and the fuel supply to the engine, but the force with which the needle is urged into the aperture is regulated by the internal spring (33). In use, the plug (30) is acted on by an abutment member (40), which is movable in step with the throttle (7) via a branch of the linkage (10). The linkage is designed to ensure that the stoichiometrically required amount of fuel is provided for the throttle opening. |
