| 摘要 |
PURPOSE:To extend the low-speed range of an engine and to thereby increase the output of the same, by forming an inclined bore portion at a venturi, opening a plurality of auxiliary slow ports of an independent, auxiliary low-speed fuel passage in said inclined bore portion, and communicating a slow port and said auxiliary slow ports with each other. CONSTITUTION:An inclined bore portion 19 is formed between a diverging portion 17 extending from a most converged portion 16 toward the downstream side of a venturi 3 and a throttle bore 18 where a throttle valve 5 is disposed, and the inclined bore portion 19 is formed with an inclined wall surface 20 which serves to keep the interspace between the marginal portion 5a of the throttle valve 5 located on the side of a slow port 14 and the wall surface 20 constant. Further, an auxiliary low-speed fuel passage 21 branched from a main fuel passage 8 and constructed in the same structure as a low-speed fuel passage 9 but independently of the same is formed i the body 1 of a carburetor, and a plurality of auxiliary slow ports 22 having a small diameter are opened in said inclined wall surface 20 and connected to an intake pas sage 2. Further, an auxiliary slow port chamber 27 and a slow port chamber 28 are connected via a passage 29 so that the slow port 14 and the auxiliary slow ports 22 are communicated with each other. |
