AIR INTAKE SILENCER

• US 3,712,416 A
• Filed: 11/26/1971
• Issued: 01/23/1973
• Est. Priority Date: 11/26/1971
• Status: Expired due to Term

• Current Assignee: Ian N. Swanson, Wayne M. Wagner
• Original Assignee: Ian N. Swanson, Wayne M. Wagner
• Inventors: Swanson, Ian N., Wagner, Wayne M.
• Primary Examiner(s): Ward, Jr., Robert S.
• Application Number:
  US05/202,357
• Time in Patent Office: 424 Days
• Field of Search: 181/33D,33E,33F,33H,33HA,33L,35R,35A,40,48,59
• US Class Current: 181/229
• CPC Class Codes: F02M 35/1216 by using a plurality of holes, slits, protrusions, perforations, ribs or the like; Surface structures; Turbulence generators
• CPC Class Codes: F02M 35/1244 using interference; Masking or reflecting sound
• CPC Class Codes: F02M 35/1261 Helmholtz resonators
• CPC Class Codes: F02M 35/162 Motorcycles; All-terrain vehicles, e.g. quads, snowmobiles; Small vehicles, e.g. forklifts

Abstract

An air intake silencer that can be quickly attached to the carburetor of a snowmobile'"'"''"'"'s internal combustion engine. The silencer contains a tuning chamber which is sized for a given engine speed in order to reflect pressure waves to provide the greatest engine torque output. The air intake silencer also contains a silencing chamber which silences the audible sound waves which are emitted from the engine. A third chamber acts as a balancing chamber between the first two chambers to further improve the engine performance.

Claims

1. For a snowmobile having a two-stroke cycle engine and a carburetor for supplying an air-fuel mixture thereto, an air intake silencer, comprising:

a. a housing having a plurality of chambers therein;

b. an air intake port mounted on said housing for the transfer of air to said housing;

c. an air outlet port for the transfer of air out of said housing;

d. means attaching said housing to said carburetor for the transfer of air from said outlet port to said carburetor;

e. a tuning chamber defined by said housing for the reflection of pressure waves of different phase from pressure waves emanating from said two-stroke cycle engine through said air outlet port;

f. a balancing chamber defined by said housing and disposed therein so that pressure waves emanating from said engine reach said balancing chamber at a later time than when said pressure waves reach said tuning chamber for the reflection of pressure waves of different phase than said waves reflected from said tuning chamber and different in phase from said waves emanating from said two-stroke cycle engine; and

g. a silencing chamber defined by said housing and disposed therein so that pressure waves emanating from said engine reach said silencing chamber at a later time than when said pressure waves reach said tuning chamber and prior to when said pressure waves reach said balancing chamber, said silencing chamber having a perforated tube mounted therein with one end extending into said tuning chamber and the other end having a gradually increasing diameter and extending into said balancing chamber for changing the phase of sound pressure waves providing for their destructive interference with other sound pressure waves.

2. An air intake silencer for internal combustion engines, comprising:

a. a housing;

b. an air intake port mounted on said housing for the transfer of air through said housing;

c. an air outlet port for the transfer of air out of said housing;

d. first means disposed within said housing for changing the phase of sound pressure waves providing for their destructive interference with other sound pressure waves;

e. second means disposed within said housing for the reflection of pressure waves of different phase from pressure waves emanating from said internal combustion engine through said air outlet port; and

f. third means disposed within said housing for the reflection of pressure waves of different phase than said pressure waves reflected by said second means, different in phase from any pressure waves reflected by said first means, and different in phase from pressure waves emanating from said internal combustion engine.

3. The apparatus of claim 2, wherein:

a. said second means includes a tuning chamber defined by said housing;

b. said third means includes a balancing chamber defined by said housing; and

c. said first means includes a silencing chamber defined by said housing with a perforated tube mounted therein with one end extending into said tuning chamber and the other end having a gradually increasing diameter and extending into said silencing chamber.

4. An air intake silencer for internal combustion engines, comprising:

a. a casing having walls, a top portion, a bottom portion, and an air inlet port for receiving air into said silencer and an air outlet port for the transfer of air out of said silencer;

b. first and second baffle plates mounted within said casing, said baffle plates having their peripheral edges secured to the interior of said walls and being spaced from each other and from the top and bottom portions of said casing, said first baffle plate associating with said top portion and said walls to define a tuning chamber, said outlet port opening said tuning chamber for the transfer of air out oF said silencer, said first baffle plate and said second baffle plate associating with said walls to define a silencing chamber, said second baffle plate associating with said bottom portion and with said walls to define a balancing chamber, said inlet port connecting said balancing chamber to a source of air, each of said baffle plates having an opening therein; and

c. a tube having a top end and a bottom end, said tube being mounted in said opening in said top baffle plate and in said opening in said bottom baffle plate, said top end thereof extending into said tuning chamber, and said bottom end thereof extending into said balancing chamber, said tube having a gradually increasing diameter at the bottom end thereof extending into said balancing chamber, said tube having perforations in the walls thereof communicating with said silencing chamber.