Multiple throttle mechanism for internal combustion engines

Claim 1

A multiple throttle mechanism for internal combustion engines comprising a main air intake passage, a plurality of intake manifold passages connected to the downstream side of main air intake passage and communicating with engine cylinders, respectively, a plurality of throttle valves provided in said intake manifold passages, respectively, and fuel injectors having fuel injection holes opened to said intake manifold passages downstream of said throttle valves, respectively, characterized by a pair of intake manifold blocks separated from each other and each having at least two parallel passages formed therethrough and a wall portion separating thereby said adjacent parallel passages, said parallel passages each being a part of said intake manifold passage and having said injection hole; a pair of throttle shafts arranged in an axial direction, said throttle shafts each crossing said parallel passages, passing through a through hole formed in said wall portion of said intake manifold block and supported on said intake manifold block, said throttle valves being mounted on said throttle shafts so that said throttle valves are operated simultaneously to control the cross sectional area of each said parallel passage; and means, including air gap defined between said through hole and said throttle shaft, for fluidly interconnecting said parallel passages in each of said intake manifold blocks and passing air from said main air intake passage into said parallel passages downstream of said throttle valves by by-passing said throttle valves, thereby providing desired fuel air ratio for each said engine cylinder during idling of the engine.