Engine intake system having a pressure wave supercharger

A supercharged diesel cycle engine comprising:

• an engine, supercharging means including casing means, rotor means rotatably carried in said casing means and having a plurality of axially extending passages, intake air inlet opening means and exhaust gas outlet opening means formed in said casing means at opposite axial ends of the rotor means, intake air outlet opening means and exhaust gas inlet opening means formed in said casing means at opposite axial ends of the rotor means, engine exhaust passage means connected with said exhaust gas inlet opening means and provided with surging chamber means, exhaust gas outlet passage means connected with said exhaust gas outlet opening means, engine supercharged air intake passage means connected with said intake air outlet opening means, engine intake air inlet passage means connected with said intake air inlet opening means, driving means for rotationally driving said rotor means so that intake air drawn into the axially extending passages in the rotor means from said engine intake air inlet passage means through said intake air inlet opening means is compressed by engine exhaust gas drawn into said axially extending passages in the rotor means from said engine exhaust passage means through said exhaust gas inlet opening means and discharged into said supercharged air intake passage means through said intake air outlet opening means, intake bypass passage means bypassing said supercharging means and connecting said intake air inlet passage means with said supercharged air intake passage means, starting valve means provided in said intake bypass passage means at a junction with said supercharged air intake passage means to open said intake bypass passage means and close said supercharged air intake passage means at least in an engine starting period to lead intake air through said intake bypass passage means, recirculation passage means extending between said engine exhaust passage means and said engine supercharged air intake passage means, said recirculation passage means being opened to said engine exhaust passage means downstream from the surging chamber means, and to said supercharged air intake passage means downstream from the junction with the intake bypass passage means, control valve means provided in said recirculation passage means, control means for controlling operation of said control valve means so that said control valve means is opened at least under light load engine operation, intercooler means provided in said supercharged air intake passage means downstream from a portion where said intake bypass passage means is connected with the supercharged air intake passage means and upstream from a portion where said recirculation passage means is opened to said supercharged air intake passage means.