JPS6178212U

JPS6178212U -

Info

Publication number: JPS6178212U
Application number: JP16336384U
Authority: JP
Priority date: 1984-10-29
Filing date: 1984-10-29
Publication date: 1986-05-26
Also published as: JPH0143449Y2

Description

[Brief explanation of the drawing]

第１図はこの考案に係るプリマフラを一部断面
にて示す正面図、第２図はその側面図、第３図は
その要部の断面図、第４図はこのプリマフラを備
えた排気系全体の構成説明図、第５図は排気系で
生じる共振モードを示す説明図、第６図はエンジ
ン回転３次成分について、通路断面積および共鳴
要素の有無による排気音の変化を示す特性図、第
７図、第８図および第９図は、上記実施例におけ
る排圧特性、排気音Ａ特性およびエンジン回転３
次成分についての排気音特性を夫々示す特性図、
第１０図はこの考案に係るプリマフラの異なる実
施例を示す要部のみの断面図、第１１図は従来に
おける排気系の構成説明図、第１２図および第１
３図は夫々従来のメインマフラおよびプリマフラ
の断面図である。１……プリマフラ、２……センタハウジング、
３……フロントハウジング、３ａ……主通路部、
３ｂ……バイパス通路部、４……リヤハウジング
、４ａ……主通路部、４ｂ……バイパス通路部、
５……容積室、６……排気入口、７……排気出口
、８……頚管、９……開閉弁、１１……負圧アク
チユエータ、１５……バイパス通路、１９……触
媒、２２……メインマフラ、２６……電磁弁、２
７……回転速度センサ、２８……制御回路。 Fig. 1 is a partially sectional front view of the pre-muffler according to this invention, Fig. 2 is a side view thereof, Fig. 3 is a sectional view of its main parts, and Fig. 4 is the entire exhaust system equipped with this pre-muffler. Fig. 5 is an explanatory diagram showing the resonance mode occurring in the exhaust system; Fig. 6 is a characteristic diagram showing the change in exhaust sound depending on the passage cross-sectional area and the presence or absence of a resonant element regarding the third-order component of engine rotation; 7, 8, and 9 show exhaust pressure characteristics, exhaust sound A characteristics, and engine speed 3 in the above embodiments.
Characteristic diagrams showing exhaust sound characteristics for the following components,
FIG. 10 is a sectional view of only the main parts showing different embodiments of the pre-muffler according to this invention, FIG. 11 is an explanatory diagram of the configuration of a conventional exhaust system, FIG.
3 are cross-sectional views of a conventional main muffler and a conventional pre-muffler, respectively. 1...Primary muffler, 2...Center housing,
3...Front housing, 3a...Main passage section,
3b... Bypass passage section, 4... Rear housing, 4a... Main passage section, 4b... Bypass passage section,
5...Volume chamber, 6...Exhaust inlet, 7...Exhaust outlet, 8...Cervical tube, 9...Opening/closing valve, 11...Negative pressure actuator, 15...Bypass passage, 19...Catalyst, 22... ...Main muffler, 26...Solenoid valve, 2
7... Rotation speed sensor, 28... Control circuit.

Claims

[Scope of utility model registration request]

A volume chamber installed upstream of the main muffler in the exhaust passage and functioning as an expansion chamber or a resonance chamber; an on-off valve disposed at either the exhaust inlet or the exhaust outlet of this volume chamber; a neck pipe section provided at the other side of the inlet or exhaust outlet; an actuator that closes the on-off valve in a low engine speed range and opens it in a high engine speed range; A pre-muffler for an automobile engine is provided with a bypass passage whose cross-sectional area is set to be smaller than that of the primary muffler of an automobile engine.