METHOD AND APPARATUS FOR ISOLATING AND MEASURING VEHICLE NOISE

• US 3,695,098 A
• Filed: 08/27/1970
• Issued: 10/03/1972
• Est. Priority Date: 08/27/1970
• Status: Expired due to Term

• Current Assignee: Kenneth C. Kirkland Jr
• Original Assignee: Kenneth C. Kirkland Jr
• Inventors: Kirkland, Kenneth C. Jr.
• Primary Examiner(s): Myracle, Jerry W.
• Application Number:
  US05/067,426
• Time in Patent Office: 768 Days
• Field of Search: 73/117.1,117 181/.5AP
• US Class Current: 73/116.01
• CPC Class Codes: G01M 15/00 Testing of engines

Abstract

Method and apparatus for individually isolating and measuring major vehicle noise sources such as the exhaust system, the air intake system and the engine. The noise sources are individually isolated, one at a time, while installed in their normal condition on the vehicle. Noise measurements are then taken on and around the vehicle while the vehicle is located on the ground similar to its operating position on a highway, with no building or reflecting surfaces near the test site which would affect the test results. The noises are individually isolated by parking the vehicle on top of a subterranean building having a soundproof room therein and by locating all but the one noise source being measured in the soundproof room. Standard measurement and analysis equipment are used.

Claims

1. A method for individually isolating and measuring noise sources of a vehicle having an engine comprising:

a. positioning the vehicle on the roof of a subterranean building having a soundproof room therein;

b. removing the noise from all other major noise sources on said vehicle except one, while retaining said other noise sources on said vehicle, by ceasing the operation of said other major noise sources;

c. operating said one noise source while all of said other major noise sources are still on said vehicle, and said one noise source is still in its normal operating condition; and

d. measuring, at a location outside of said building, the sound emitted from said vehicle, while said one noise source is operating in its normal condition on said vehicle and while said other major noise sources are still on said vehicle.

2. The method according to claim 1 including repeating steps (b), (c), and (d) for a different said one noise source.

3. The method according to claim 1 wherein said operating step comprises operating said noise source throughout a range of noise levels for said one noise source.

4. The method according to claim 1 wherein said measuring step comprises measuring the sound emitted from said one noise source at a plurality of different locations on and around said vehicle.

5. The method according to claim 1 including maintaining the area within a predetermined radius of said building free of sound reflecting surfaces.

6. The method according to claim 1 wherein said vehicle has an engine, an exhaust system, an air intake system, and a cooling system, and wherein said one noise source is engine noise and wherein said removing step comprises:

i. eliminating the exhaust noise by disconnecting the vehicle engine from its exhaust system and by connecting the vehicle engine to a secondary exhaust system within said soundproof room. ii. eliminating the air intake noise by disconnecting the vehicle engine from its normal air intake system and by connecting the vehicle engine to a secondary air intake system within said soundproof room;

iii. eliminating the cooling fan noise be removing the cooling fan from the vehicle engine and by disconnecting thE vehicle engine from its radiator and by connecting the vehicle engine to a secondary cooling system within said soundproof room; and

iv. eliminating tire noise by disconnecting the vehicle engine from its normal drive shaft and by connecting the vehicle engine to a dynamometer within said soundproof room.

7. The method according to claim 1 wherein said vehicle has an engine, an exhaust system, an air intake system, and a cooling system, and wherein said one noise source is exhaust noise and wherein said removing step comprises:

i. maintaining the vehicle engine in its off condition;

ii. providing a secondary engine equivalent to said vehicle engine, within said soundproof room;

iii. connecting said secondary engine to a dynamometer within said soundproof room;

iv. connecting said secondary engine to a secondary cooling system within said soundproof room;

v. connecting said secondary engine to a secondary air intake system within said soundproof room; and

vi. connecting said secondary engine to the normal exhaust system on said vehicle.

8. The method according to claim 7 including employing a pipe from said secondary engine to a muffler of said normal exhaust system on said truck of approximately equal length to the pipe running from said vehicle engine to said muffler.

9. The method according to claim 1 wherein said vehicle has an engine, an exhaust system, an air intake system, and a cooling system, and wherein said one noise source is air intake noise and wherein said removing step comprises:

i. maintaining said vehicle engine in its off condition;

ii. providing a secondary engine in said soundproof room equivalent to said vehicle engine;

iii. connecting said secondary engine to a dynamometer within said soundproof room;

iv. connecting said secondary engine to a secondary cooling system within said soundproof room;

v. connecting said secondary engine to a secondary exhaust system within said soundproof room; and

vi. connecting said secondary engine to said vehicle air intake system.

10. The method according to claim 1 wherein said ceasing step comprises disconnecting said other major noise sources from said one, and by connecting said one major noise source to secondary noise sources positioned in said soundproof room, whereby said one major noise source can be operated in its normal condition.

11. A method for individually isolating and measuring noise sources of a vehicle having an engine comprising:

a. positioning said vehicle adjacent a building having a soundproof room;

b. individually isolating any one major noise source of said vehicle, while all of said major noise sources are located on said vehicle, by eliminating from said vehicle the noise produced by all other major noise sources except said one by ceasing the operation of said other major noise sources;

c. operating said one noise source in its normal condition; and

d. measuring, at a location outside of said building, the sound emitted from said vehicle, while said one noise source is operating in its normal condition on said vehicle and while said other major noise sources are still on said vehicle.

12. A method for measuring noise produced by a vehicle having the three major noise sources of an engine, an engine exhaust system, and an engine air intake system comprising sequentially, individually, isolating the noise produced by:

said vehicle engine, said vehicle engine exhaust system, and said vehicle engine air intake system, while each one of the above-listed elements is located on said vehicle, by eliminating the noise produced by the other two noise sources by ceasing their operation, and sequentially measuring the noise produced by said vehicle with all three noise sources on the vehicle, and with the noise from two of the three sources having been eliminated.

13. Apparatus for individually isolating noise sources of a vehicle having an engine comprising:

a. a subterranean building having a soundproof room therein and having a roof, and a vehicle having an engine and being positioned on said roof;

b. a secondary engine positioned in said soundproof room equivalent to said vehicle engine;

c. a dynamometer in said room;

d. a secondary cooling system in said room;

e. a secondary exhaust system in said room;

f. a secondary air intake system in said room; and

g. means for independently connecting said elements (c), (d), (e), and (f) to one of said vehicle engine and said secondary engine.

14. The apparatus according to claim 13 wherein said secondary exhaust system includes an exhaust pipe extending away from said building and having an exhaust opening above ground located sufficiently far from said building that any sound produced at said opening will not affect any sound measurements taken adjacent said building.

15. The apparatus according to claim 13 wherein said air intake system includes an air intake pipe extending away from said building and having an air inlet opening above ground located sufficiently far from said building that any sound produced at said opening will not affect any sound measurements taken adjacent said building.

16. The apparatus according to claim 13 including an area, within a predetermined radius of said building, free of sound reflecting surfaces.