Patent ID: 8894759

Claim:
A cogeneration apparatus comprising: a motor; an electrical generator driven by the motor; a heat exchanger for using waste heat of the motor as a heat source; an air-cleaning device, provided to an intake system of the motor, for purifying outside air introduced into the motor, wherein the air-cleaning device comprises: an air-cleaning case communicating with the intake system; an air filter provided at a position where a space within the air-cleaning case is split into an upstream space and a downstream space and being capable of purifying outside air led into the upstream space and of introducing the outside air to the downstream space; and a hollow resonator positioned in the downstream space at a predetermined interval with respect to the air-cleaning case and having an internal space, so that outside air passed through the downstream space is introduced into the internal space of the resonator to thereby limit intake noise of the outside air and the outside air introduced into the internal space of the resonator passes through the internal space and is led outside of the resonator, the resonator comprising: an introduction port disposed on an opposite side of the air filter and communicating the downstream space with the internal space, and a lead-out port communicating the internal space with a throttle valve of the intake system, the lead-out port being provided above the introduction port, wherein the resonator is positioned at a predetermined interval within the air-cleaning case to define a downstream-space channel between the air-cleaning case and the resonator, so that the outside air led from the intake system to the upstream space is led through the air filter to the downstream-space channel, the outside air led to the downstream-space channel is led through the introduction port to the internal space of the resonator, and the outside air led to the internal space is led out through the lead-out port to the throttle valve the lead-out port having a cross-sectional area S 1 , the introduction port having a cross-sectional area S 2 , and the cross-sectional areas S 1 and S 2 having a relationship such that S 1 >S 2 , the downstream-space channel having a cross-sectional area S 3 , and the cross-sectional areas S 3 and S 2 having a relationship such that S 3 >S 2 , and the cross-sectional areas S 3 and S 1 having a relationship such that S 3 >S 1 .