Outboard motor with sound enhancement device and method for modifying sounds produced by air intake system of an outboard motor

Patent metadata

Field	Value
Publication number	US-9909545-B1
Application number	US-201615219617-A
Country	US
Kind code	B1
Filing date	Jul 26, 2016
Priority date	Jul 26, 2016
Publication date	Mar 6, 2018
Grant date	Mar 6, 2018

Abstract

An outboard motor includes an internal combustion engine powering the outboard motor and a cowl covering the engine and having a vent allowing air under the cowl. A throttle body meters flow of the air into the engine and an intake structure downstream of the throttle body delivers the metered airflow to one or more combustion chambers in a cylinder block of the engine. A sound enhancement assembly in acoustic communication with the intake structure collects sounds emitted by the engine. The sound enhancement assembly is configured to amplify a subset of the collected sounds that have frequencies within a desired frequency range. A method for modifying sounds produced by an air intake system of an internal combustion engine powering an outboard motor is also disclosed. The method includes positioning a sound enhancement assembly in acoustic communication with an air intake passageway located downstream of the engine's throttle body.

First claim

What is claimed is:

1. An outboard motor comprising:
an internal combustion engine powering the outboard motor;
a cowl covering the engine and having a vent allowing air under the cowl;
a throttle body metering flow of the air into the engine;
an intake structure downstream of the throttle body that delivers the metered airflow to one or more combustion chambers in a cylinder block of the engine; and
a sound enhancement assembly including an assembly housing, the sound enhancement assembly being in acoustic communication with the intake structure downstream of the throttle body and collecting sounds emitted by the engine;
wherein the sound enhancement assembly includes a sound enhancement device located within the assembly housing that is tuned to amplify a subset of the collected sounds that have frequencies within a desired frequency range.

2. The outboard motor of claim 1 , wherein the sound enhancement assembly includes an inlet pipe coupled to the intake structure that collects the sounds emitted by the engine and directs the collected sounds into the assembly housing.

3. The outboard motor of claim 2 , wherein the inlet pipe is coupled to the intake structure upstream of a cylinder head attached to the cylinder block of the engine.

4. The outboard motor of claim 2 , wherein the sound enhancement assembly includes an outlet pipe having an upstream end coupled to the assembly housing downstream of the sound enhancement device, wherein the outlet pipe transmits the amplified subset of the collected sounds to an area outside the cowl.

5. The outboard motor of claim 4 , wherein the sound enhancement assembly includes an acoustically transparent shield positioned above the inlet pipe upstream of the sound enhancement device that protects the sound enhancement device from particulates in the intake structure.

6. The outboard motor of claim 4 , wherein a downstream end of the outlet pipe is coupled to a lower portion of the cowl.

7. The outboard motor of claim 4 , wherein the intake structure defines a first passageway that is separate and distinct from a second passageway defined by the outlet pipe.

8. The outboard motor of claim 4 , wherein the assembly housing comprises a first mounting flange that is integral with the intake structure and a second mounting flange that is integral with the upstream end of the outlet pipe, the first and second mounting flanges being connected to one another in an airtight manner.

9. The outboard motor of claim 2 , wherein the sound enhancement device is a membrane, and further comprising a tensioner disk clamped within the assembly housing and stretching the membrane to maintain a given tension of the membrane.

10. The outboard motor of claim 9 , further comprising at least one travel guard disk located in the assembly housing on at least one of an upstream side and a downstream side of the membrane that prevents the membrane from distending by more than a predetermined distance in response to a pressure pulse.

11. The outboard motor of claim 3 , wherein the intake structure comprises a plenum downstream of the throttle body and one or more intake runners extending from the plenum to the one or more combustion chambers of the engine, and wherein the inlet pipe is coupled to the plenum.

12. A method for modifying sounds produced by an air intake system of an internal combustion engine powering an outboard motor, the method comprising:
positioning a sound enhancement assembly including an assembly housing in acoustic communication with an air intake passageway located downstream of a throttle body of the engine;
providing the acoustic communication downstream of the throttle body;
tuning a sound enhancement device of the sound enhancement assembly so that the sound enhancement device amplifies a subset of sounds emitted by the engine that have frequencies within a desired frequency range;
transmitting the amplified subset of sounds as sound pressure pulses through a sound passageway of the sound enhancement assembly to an area outside a cowl covering the engine; and
preventing fluid communication between the air intake passageway and the sound passageway by providing a fluid-tight seal between the air intake passageway and the sound passageway.

13. The method of claim 12 , further comprising collecting sounds emitted by the engine with an inlet pipe of the sound enhancement assembly, the inlet pipe being coupled to the air intake passageway so as to direct the collected sounds into the assembly housing.

14. The method of claim 13 , wherein the sound enhancement device comprises a flexible membrane, and further comprising placing the membrane within the assembly housing and maintaining a given tension on the membrane by stretching the membrane with a tensioner disk.

15. The method of claim 13 , further comprising providing at least one travel guard disk in the assembly housing that prevents the sound enhancement device from distending by more than a predetermined distance in response to a pressure pulse.

16. The method of claim 15 , further comprising providing a first travel guard disk on an upstream side of the sound enhancement device and a second travel guard disk on a downstream side of the sound enhancement device.

17. The method of claim 13 , further comprising providing a shield upstream of the sound enhancement device that shields the sound enhancement device from particulates in the air intake passageway.

18. The method of claim 13 , further comprising connecting an outlet pipe to the assembly housing downstream of the sound enhancement device, wherein the outlet pipe defines the sound passageway.

19. The method of claim 12 , wherein the air intake passageway is defined by a plenum downstream of the throttle body and one or more intake runners extending from the plenum to one or more combustion chambers of the engine.

Assignees

• Brunswick Corp

Inventors

• Waisanen Andrew S
• Etapa Jeffrey C
• Jaszewski Wayne M
• Broman Jeffrey J
• Fregonese Brian J

Classifications

• B63H20/32

  Housings {(air intakes for outboard engines F02M35/167)} · CPC title

• F02M35/10242 Primary

  Devices or means connected to or integrated into air intakes; Air intakes combined with other engine or vehicle parts (filters F02M35/02; silencers F02M35/12 and F02M35/14; air coolers F02B29/04; heaters F02M31/00; air storage tanks F02B21/00; compressors F02B33/00; sensors F02M35/10373) · CPC title

• F02M35/104

  Intake manifolds · CPC title

• B63H20/001

  Arrangements, apparatus and methods for handling fluids used in outboard drives (for handling exhaust gas B63H20/24; for handling cooling-water B63H20/28; cooling outboard marine engines F01P3/202; air intakes for outboard marine engines F02M35/167) · CPC title

• F02B61/045

  for marine engines · CPC title