排气放气阀车用发动机的转速变化范围较大,涡轮增压器受发动机及增压器特性的限制,难以在低速端和高速端均获得最佳匹配。如果按高速端匹配,则低速端增压压力不足,为了不使排放性能恶化,不得不限制燃油量,从而牺牲了低速扭矩,影响了低速工作性能。当按低速端匹配时,考虑到柴油机的寿命和效率,有的柴油机采取了适当降低压缩比和标 Exhaust deflation valve vehicle engine speed range, Turbocharger by the engine and supercharger characteristics of the restrictions, it is difficult at the low-speed and high-speed are the best match. If the high-speed end match, the low-speed side of the supercharged pressure is not enough, in order not to deteriorate the emission performance, have to limit the amount of fuel, thus sacrificing low-speed torque, affecting low-speed performance. When matched by the low-speed side, taking into account the life and efficiency of the diesel engine, some diesel engines have taken appropriate compression ratio reduction and standard