SUPERCHARGER

PROBLEM TO BE SOLVED: To provide a supercharger considering a startability, exhaust emission control, and fuel consumption in a diesel engine.SOLUTION: A supercharger 1 is equipped with a compressor 3 which compresses air and supplies the air to a diesel engine 53; a branch flow path 71 which makes a part of the air compressed by the compressor 3 branch off from a discharge port 11 of the compressor 3 to carry the air to a sending destination other than the diesel engine 53; and a gate portion 73 which opens/closes the branch flow path 71. The gate portion 73 opens the branch flow path 71 when a load factor of the diesel engine 53 is within a range from a predetermined lower limit threshold value to an upper limit threshold value, and closes the branch flow path 71 in other times.SELECTED DRAWING: Figure 2 【課題】ディーゼル機関における始動性、排ガス浄化性及び燃費を考慮した過給機を提供する。【解決手段】過給機１は、空気を圧縮しディーゼル機関５３に供給するコンプレッサ３と、コンプレッサ３で圧縮された空気の一部をコンプレッサ３の吐出口１１から分岐させディーゼル機関５３以外の送出先に搬送する分岐流路７１と、分岐流路７１を開閉するゲート部７３と、を備え、ゲート部７３は、ディーゼル機関５３の負荷率が、所定の下限閾値から上限閾値までの範囲内であるときには分岐流路７１を開き、それ以外のときには分岐流路７１を閉じる。【選択図】図２