公开(公告)号：US3967446A

公开(公告)日：1976-07-06

申请号：US500634

申请日：1974-08-26

申请人： Joseph H. Harralson ,  William F. Wurzbach

发明人： Joseph H. Harralson ,  William F. Wurzbach

IPC分类号： F01N1/02 ,  B63H20/24 ,  B63H21/32 ,  F01N13/12 ,  F02B27/04 ,  F02B61/04 ,  F02B27/02 ,  B63H5/13 ,  F01N7/12

CPC分类号： F01N13/12 ,  B63H20/245 ,  F02B61/045

摘要： A tuned exhaust gas relief system for marine propulsion systems, for example an outboard motor, includes a lower drive shaft housing coupled to a two stroke engine by a pair of intermediate stacked exhaust extension plates. The housing directs the exhaust gas downwardly to a through-the-hub exhaust propeller for exit therethrough. With the unit in reverse or idling, exhaust gases are trapped within the housing. A pair of tuned exhaust relief passageways may be formed by cavities in the mating faces of the two extension plates with a pair of inlet openings in the lower wall of the bottom plate. A baffle member may overlie the inlet openings. The passageways define constant cross-sectional area channels which terminate in exhaust openings in the rear wall of the drive shaft housing. A resonant cavity, which may be integrally formed by mating recesses in the opposed faces of the extension plates, is in close spaced relation to each idle exhaust passageway. Connecting openings are distributed along the length of the common wall between the cavity and passageway. An exhaust housing within the drive shaft housing forms an exhaust expansion chamber of high acoustical impedance between the lower ends of the exhaust pipe means and the upper wall extension plate assembly. The idle exhaust passageways have a low acoustical impedance, so that the acoustical impedance mismatch between the chamber and the passageways attenuates the high frequency sounds. The idle exhaust passageways may transmit the half wave frequency and even multiplies thereof. The resonator cavity is selected to attenuate the particular half wave frequency, or an even multiple thereof, which because of physical space requirements may be present and not attenuated by the idle exhaust passageway means.

摘要翻译： 用于船用推进系统（例如舷外马达）的调节废气释放系统包括通过一对中间堆叠排气延伸板联接到二冲程发动机的下驱动轴壳体。 壳体将废气向下引导到通过轮毂的排气螺旋桨从其中排出。 当设备反向或空转时，废气被困在壳体内。 一对调谐的排气释放通道可以由两个延伸板的配合面中的空腔形成，在底板的下壁中具有一对入口。 挡板构件可以覆盖入口开口。 通道限定恒定的横截面积通道，其终止于驱动轴壳体的后壁中的排气口。 可以通过在延伸板的相对面中配合凹部而一体地形成的谐振腔与每个空闲的排气通道紧密隔开。 连接孔沿腔体和通道之间的公共壁的长度分布。 驱动轴壳体内的排气壳体在排气管装置的下端和上壁延伸板组件之间形成高阻抗的排气膨胀室。 空闲的排气通道具有低的声阻抗，使得腔室和通路之间的声阻抗失配使高频声音衰减。 空闲的排气通道可以传输半波频率和偶数倍。 选择谐振器腔以衰减特定的半波频率或其偶数倍，这是由于物理空间要求可能存在并且不被空闲排气通道装置衰减。