Information
-
Patent Grant
-
6698390
-
Patent Number
6,698,390
-
Date Filed
Friday, January 24, 200321 years ago
-
Date Issued
Tuesday, March 2, 200420 years ago
-
Inventors
-
Original Assignees
-
Examiners
- Yuen; Henry C.
- Harris; Katrina B.
Agents
- MacMillan, Sobanski & Todd, LLC
-
CPC
-
US Classifications
Field of Search
US
- 123 18455
- 123 18457
- 181 229
- 181 241
- 181 250
-
International Classifications
-
Abstract
A variable tuned telescoping resonator which militates against the emission of noise energy caused by intake air in a vehicle wherein the connector length and the volume of the resonator are varied as a function of engine speed simultaneously to provide attenuation of noise energy over a wide frequency range.
Description
FIELD OF THE INVENTION
The invention relates to a resonator and more particularly to a variable tuned telescoping resonator for control of engine induction noise in a vehicle wherein the connector length and volume of the resonator are varied simultaneously.
BACKGROUND OF THE INVENTION
In an internal combustion engine for a vehicle, it is desirable to design an air induction system in which sound energy generation is minimized. Sound energy is generated as fresh air is drawn into the engine. Vibration is caused by the intake air in the air feed line which creates undesirable intake noise. Resonators of various types such as a Helmholtz type, for example, have been employed to reduce engine intake noise. Such resonators typically include a single, fixed volume chamber for dissipating the intake noise. Additionally, multiple resonators are frequently required to attenuate several noise peaks of different frequencies.
Desired noise level targets have been developed for a vehicle engine induction system. When engine order related inlet orifice noise targets are specified to be within narrow limits as a function of engine speed, the target line often cannot be met with a conventional multi-resonator system. The typical reason is that conventional resonator systems provide an attenuation profile that does not match the profile of the noise and yields unwanted accompanying side band amplification. This is particularly true for a wide band noise peak. The result is that when a peak value is reduced to the noise level target line at a given engine speed, the amplitudes of adjacent speeds are higher than the target line. Thus, the resonators are effective at attenuating noise at certain engine speeds, but ineffective at attenuating the noise at other engine speeds.
It would be desirable to produce a resonator which is variable tuned to militate against the emission of sound energy caused by the intake air at a wide range of engine speeds.
SUMMARY OF THE INVENTION
Consistent and consonant with the present invention, a variable tuned telescoping resonator which militates against the emission of sound energy caused by the intake air at a wide range of engine speeds, has surprisingly been discovered.
The variable tuned resonator system comprises:
an inner telescoping section adapted to provide fluid communication with a duct, the inner telescoping section defining a resonator connector length; and
an outer telescoping section surrounding the inner telescoping section to define a chamber therebetween, the inner telescoping section and the outer telescoping section being selectively extensible and collapsible to thereby change at least one of a volume of the chamber and the resonator connector length;
wherein changing the at least one of the volume of the chamber and the resonator connector length facilitates attenuation of a desired frequency of sound entering the resonator.
BRIEF DESCRIPTION OF THE DRAWINGS
The above, as well as other objects, features, and advantages of the present invention will be understood from the detailed description of the preferred embodiments of the present invention with reference to the accompanying drawings, in which:
FIG. 1
is a perspective view of a variable tuned telescoping resonator shown in the extended position, with the resonator mounted on a duct and the resonator shown in section, incorporating the features of the present invention;
FIG. 2
is a perspective view of the variable tuned telescoping resonator illustrated in
FIG. 1
shown in the collapsed position, with the resonator shown in section;
FIG. 3
is a partial sectional view of the variable tuned telescoping resonator illustrated in
FIG. 1
with helical springs for sequencing of the telescoping segments;
FIG. 4
is a partial sectional view of the variable tuned telescoping resonator illustrated in
FIG. 1
showing an alternate embodiment for sequencing the telescoping segments using leaf type springs;
FIG. 5
is a schematic diagram of the variable tuned telescoping resonator illustrated in
FIG. 1
with a control system for controlling the volume and connector length of the resonator at different engine speeds;
FIG. 6
is a graph showing a plot of the sound pressure level (SPL) in decibels vs. engine speed in RPM for noise emission without a resonator, noise emission with a one liter volume resonator, noise emission with a two liter volume resonator, and a target level for noise emission; and
FIG. 7
is a schematic diagram of an alternate embodiment of the invention showing a resonator including an inner telescoping member operably coupled with a piston.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, and particularly
FIG. 1
, there is shown generally at
10
a variable tuned telescoping resonator shown in the expanded position for use in a vehicle air intake system (not shown). The resonator
10
is mounted on and in fluid communication with a duct
12
which is in communication with the vehicle air intake system. A connector
14
attaches the resonator
10
with the duct
12
. The connector
14
has a neck length
16
and a neck diameter
18
.
The resonator
10
includes a hollow main housing
20
. Disposed within the housing
20
are an inner telescoping section
22
and an outer telescoping section
24
. In the embodiment shown, five distinct inner telescoping segments
25
a
are included in the inner telescoping section
22
and five distinct outer telescoping segments
25
b
are included in the outer telescoping section
24
. It is understood that additional or fewer telescoping segments
25
a
,
25
b
could be used to arrive at a desired connector length and volume without departing from the scope and spirit of the invention. Additionally, one of the functions of the housing
20
is to provide stops to limit the movement of the telescoping segments
25
a
,
25
b
. It is understood that other internal or external stops could be used to replace the housing
20
without departing from the scope and spirit of the invention.
The inner telescoping section
22
defines an inner chamber
26
and the outer telescoping section
24
cooperates with an outer wall of the inner telescoping section
22
to define an outer;chamber
28
. Together, the inner chamber
26
and the outer chamber
28
define the hollow interior of the resonator
10
volume. A first end
30
of the inner telescoping section
22
communicates with the connector
14
of the resonator
10
. A second end
32
of the inner telescoping section
22
is open to the outer chamber
28
. A first end
34
of the outer telescoping section
24
is spaced radially from the first end
30
of the inner telescoping section
22
and adjacent an inner wall of the housing
20
. A second end
36
of the outer telescoping section
24
is spaced radially and longitudinally from the second end
32
of the inner telescoping section
22
and adjacent the inner wall of the housing
20
. The second end
36
of the outer telescoping section
24
is closed to form the outer chamber
28
within the outer telescoping section
24
.
A plurality of radial struts
38
are disposed between and connect each adjacent inner telescoping segment
25
a
and outer telescoping segment
25
b
. A plurality of helical springs
40
is disposed between each adjacent outer telescoping segment
25
b
, as illustrated in FIG.
3
. Alternatively, a plurality of leaf type springs
42
is disposed to abut the inner telescoping segments
25
a
and the radial strut
38
of the adjacent inner telescoping segment
25
a, as illustrated in FIG.
4
. It is understood that other spring types, configurations, and locations could be used without departing from the scope and spirit of the invention. A stop tab
44
extends radially outwardly from an outer surface of each of the outer telescoping segments
25
b
. Three tabs
44
are spaced circumferentially at 120 degrees apart in the embodiment shown. The tab
44
is disposed in a slot
45
as clearly shown in
FIGS. 1 and 2
. Inner o-rings
46
are disposed between adjacent inner telescoping segments
25
a
and outer o-rings
48
are disposed between adjacent outer telescoping segments
25
b
.
FIG. 2
shows the telescoping sections
22
,
24
in the collapsed position, which can be attained using a motive driver connected to a linkage, an example of which is shown schematically in FIG.
5
. It is also understood that the linkage can be received in and guided by an aperture in a wall of the housing
20
, for example.
Referring now to
FIG. 5
, there is shown a schematic diagram of the resonator
10
including a control system
52
for controlling the extending and collapsing of the telescoping sections
22
,
24
. By controlling the telescoping sections
22
,
24
, the resonator volume
54
(volume of the outer chamber
28
) and resonator connector length
56
(the neck length
16
of the connector
14
plus the length of the inner telescoping section
22
) are controlled at different vehicle engine speeds. A programmable control module or PCM
60
is electrically connected to a motor
62
. The motor
62
is drivingly engaged with a rack and pinion type actuator
64
. It is understood that other actuator types may be used without departing from the scope and spirit of the invention. The rack portion of the rack and pinion actuator
64
is connected to the resonator
10
such that the resonator volume
54
and the resonator connector length
56
can be selectively varied as desired. A position sensor and transmitter
66
provides positional feedback to the PCM
60
from the resonator
10
. An engine speed sensor and transmitter
68
senses and transmits engine speed to the PCM
60
. The PCM
60
accesses a PCM table
70
to find a required position for the resonator
10
based upon engine speed. The required position of the resonator
10
is then compared with the positional feedback from the position sensor and transmitter
66
. If the positional feedback differs from the required position, a position adjustment is made by the PCM
60
by operating the motor
62
to adjust the rack and pinion actuator
64
as needed. It is understood that other structures could be used to vary the resonator volume
54
and the resonator connector length
56
such as a stepper motor, for example.
In operation, air travels through the duct
12
. Sound generated by the vehicle engine travels through the duct
12
and enters the resonator
10
through the connector
14
. A sound frequency generated by the engine differs at different engine speeds. Therefore, in order to meet target sound pressure levels, the resonator
10
is required to attenuate a wide range of frequencies. This is accomplished by varying the resonator connector length
56
and the resonator volume
54
. The inner telescoping section
22
acts as an adjustable extension to the connector
14
and thereby permits adjustment of the resonator connector length
56
. Adjustment of the length of the outer telescoping section
24
permits adjustment of the resonator volume
54
. Simultaneous adjustment of the inner telescoping section
22
and the outer telescoping section
24
facilitates fine tuning of the resonator
10
over a wide range of frequencies. Thus, the desired attenuation of sound emitted from the vehicle engine over a wide range of frequencies is accomplished. It is understood that the inner telescoping section
22
and the outer telescoping section
24
can be independently adjusted without departing from the scope and spirit of the invention.
The method of controlling the resonator
10
by the PCM
60
is accomplished by first mapping the characteristics of the resonator
10
at various telescoping positions at each engine speed. The resonator position versus engine speed is organized into the PCM table
70
. The resonator positions are determined by comparing the difference between base and target characteristics at each engine speed to a map of resonator performance. The resonator position which best meets the target at each engine speed is organized into the PCM table
70
. It should be noted that to achieve the best efficiency, the resonator
10
should be placed in the air induction system of the vehicle where it will most efficiently attenuate the frequencies of interest. For example, the chosen location should not be near a pressure nodal point of the frequencies of interest, but at a location where the standing wave pressures for the frequencies of interest are values which would provide reasonable attenuation.
The resonator
10
can be precisely controlled by controlling the repeatability of the telescoping motion of the inner telescoping section
22
and the outer telescoping section
24
. To be repeatable, the telescoping motion of the inner telescoping section
22
and the outer telescoping section
24
in each section must occur in the same sequence when extending or contracting. The position of each of the telescoping segments
25
a
,
25
b
must be the same when in the extending or the contracting mode. The repeatability is accomplished using two distinct methods. First, the axial position of the telescoping segments
25
a
,
25
b
is maintained by the radial struts
38
. Second, in the embodiments using the springs
40
and the springs
42
, the spring constant of the springs
40
and the springs
42
are designed so that the compression force required to move each of the telescoping segments
25
a
,
25
b
adjacent the first ends
30
,
34
of the telescoping sections
22
,
24
, respectively, is an order of magnitude higher than the frictional forces generated by the o-rings
46
,
48
of the telescoping segments
25
a
,
25
b
adjacent the second ends
32
,
36
of the telescoping sections
22
,
24
, respectively. Additionally, the tab
44
militates against the telescoping segments
25
a
,
25
b
from extending beyond a desired telescoping position.
FIG. 6
illustrates the attenuation characteristics of fixed volume resonators. Curve A shows the sound pressure level or SPL in decibels without a resonator. Curve B shows the SPL with a 1.0 liter volume resonator. Curve C shows the SPL with a 2.0 liter volume resonator. Line D shows a target SPL. Fixed volume resonators provide a notch type attenuation with side band amplification that does not match the attenuation required to reduce a noise peak to a specific target line. As illustrated by curve B in
FIG. 6
, a low volume 1.0 liter resonator attenuates the SPL at 4500 rpm to near the target line D, but the remainder of curve B remains above the target line D. As the resonator gets larger, providing more attenuation, the attenuation bandwidth and notch depth increases. For the 2.0 liter resonator, the curve C is equal or below the target line D from 4000 to 5000 rpm. However, the side band amplification
80
of the 2.0 liter resonator is increased compared to the side band amplification
82
of the 1.0 liter resonator. As
FIG. 6
illustrates, notch type attenuation does not provide the degree of control required to meet a specific target line.
The resonator
10
minimizes the problems associated with the fixed volume or notch type attenuation resonator, since at each engine speed the resonator
10
can be set to a desired telescoping position to provide the required attenuation. Additionally, where part of the noise curve lies below the target line D, amplification can be provided in the side band amplification region of the SPL curve to reach the target line D as desired.
An alternate embodiment of the invention is illustrated in
FIG. 7. A
resonator
90
includes a main housing
91
is connected to a duct
92
by a connector
94
. A first end
96
of an inner telescoping section
98
communicates with the connector
94
. A second end
100
of the inner telescoping section
98
is coupled to a piston
102
which cooperates with the inner walls of the housing
91
to form a resonator chamber
104
. The inner telescoping section
98
cooperates with the connector
94
to define a resonator connector length. A seal
106
is disposed between an outer wall of the piston
102
and the inner wall of the housing
91
. An actuator assembly
108
operatively connects the piston
102
with a motor
110
.
In operation, the position of the piston
102
is varied to vary a volume of the resonator chamber
104
. As the piston
102
is caused to move towards the connector
94
, the volume of the resonator chamber
104
is decreased. As the piston
102
is caused to move away from the connector
94
, the volume of the resonator chamber
104
is caused to increase. The inner telescoping section
96
is likewise caused to move with the piston
102
. As the piston
102
is caused to move towards the connector
94
, the inner telescoping section
98
is caused to collapse, thereby decreasing the resonator connector length. As the piston
102
is caused to move away from the connector
94
, the inner telescoping section
98
is caused to extend, thereby increasing the resonator connector length. Thus, by controlling the piston
102
and the inner telescoping section
98
to vary the volume of the resonator chamber
104
and the resonator connector length as described for the other embodiments of the invention, the resonator
90
is effective to control a wide range of sound frequencies. It should be noted that the piston
102
can be used with a resonator having a fixed resonator connector length without departing from the scope and spirit of the invention.
From the foregoing description, one ordinarily skilled in the art can easily ascertain the essential characteristics of this invention and, without departing from the spirit and scope thereof, can make various changes and modifications to the invention to adapt it to various usages and conditions.
Claims
- 1. A variable tuned resonator comprising:an inner telescoping section adapted to provide fluid communication with a duct, said inner telescoping section defining a resonator connector length; and an outer telescoping section surrounding said inner telescoping section to define a chamber therebetween, said inner telescoping section and said outer telescoping section being selectively extensible and collapsible to thereby change at least one of a volume of the chamber and the resonator connector length; wherein changing the at least one of the volume of the chamber and the resonator connector length facilitates attenuation of a desired frequency of sound entering the resonator.
- 2. The resonator according to claim 1, wherein both the volume of the chamber and the resonator connector length are changed simultaneously.
- 3. The resonator according to claim 1, wherein said inner telescoping section and said outer telescoping section are concentric.
- 4. The resonator according to claim 1, wherein said inner telescoping section and said outer telescoping section are joined by a plurality of radial struts to cause said inner telescoping section and said outer telescoping section to extend and collapse simultaneously.
- 5. The resonator according to claim 1, wherein said inner telescoping section includes a plurality of inner telescoping segments.
- 6. The resonator according to claim 5, wherein a spring is disposed between each of the inner telescoping segments, the spring urging said inner telescoping section towards an extended position.
- 7. The resonator according to claim 1, wherein said outer telescoping section includes a plurality of outer telescoping segments.
- 8. The resonator according to claim 7, wherein a spring is disposed between each of the outer telescoping segments, the spring urging said outer telescoping section towards an extended position.
- 9. A variable tuned resonator comprising:an inner telescoping section adapted to provide fluid communication with a duct, said inner telescoping section defining a resonator connector length; an outer telescoping section surrounding said inner telescoping section to define a chamber therebetween, said inner telescoping section and said outer telescoping section being selectively extensible and collapsible to thereby change at least one of a volume of the chamber and the resonator connector length, wherein changing the at least one of the volume of the chamber and the resonator connector length facilitates attenuation of a desired frequency of sound travelling through said duct; and a resonator control system comprising: a programmable control module; and an actuator adapted to be controlled by said programmable control module, said actuator operatively engaged with said inner telescoping section and said outer telescoping section to extend and collapse said inner telescoping section and said outer telescoping section to thereby control the volume of the chamber and the resonator connector length; wherein said programmable control module controls said actuator responsive to engine speed of an automobile engine.
- 10. The resonator according to claim 9, including an engine speed sensor and transmitter to sense and transmit engine speed to said programmable control module.
- 11. The resonator according to claim 9, wherein said actuator is a rack and pinion type actuator.
- 12. The resonator according to claim 9, wherein both the volume of the chamber and the resonator connector length are changed simultaneously.
- 13. The resonator according to claim 9, wherein said inner telescoping section and said outer telescoping section are joined by a plurality of radial struts to cause said inner telescoping section and said outer telescoping section to extend and collapse simultaneously.
- 14. The resonator according to claim 9, wherein said inner telescoping section includes a plurality of inner telescoping segments.
- 15. The resonator according to claim 14, wherein a spring is disposed between each of the inner telescoping segments, the spring urging said inner telescoping section towards an extended position.
- 16. The resonator according to claim 9, wherein said outer telescoping section includes a plurality of outer telescoping segments.
- 17. The resonator according to claim 16, wherein a spring is disposed between each of the outer telescoping segments, the spring urging said outer telescoping section towards an extended position.
- 18. A variable tuned resonator comprising:a hollow housing having a connector adapted to provide fluid communication with a duct; an inner telescoping section disposed within said housing and having a first end and a second end, the first end of said inner telescoping section in fluid communication with the connector of said housing, said inner telescoping section and the connector cooperating to define a resonator connector length; and a piston selectively reciprocable within said housing and cooperating with said housing to form a resonator chamber, said piston coupled to the second end of said inner telescoping section and causing said inner telescoping section to extend and collapse during reciprocation of said piston, reciprocation of said piston changing a volume of the resonator chamber, and extending and collapsing of said inner telescoping section changing the resonator connector length; wherein changing the volume of the resonator chamber and the resonator connector length facilitates attenuation of a desired frequency of sound entering the resonator.
- 19. A variable tuned resonator comprising:a hollow housing having a connector adapted to provide fluid communication with a duct; an inner telescoping section in fluid communication with the connector of said housing and disposed within said housing, said inner telescoping section and the connector cooperating to define a resonator connector length; and an outer telescoping section disposed within said housing and surrounding said inner telescoping section to define a chamber therebetween, said inner telescoping section and said outer telescoping section being selectively extensible and collapsible to thereby change at least one of a volume of the chamber and the resonator connector length; wherein changing the at least one of the volume of the chamber and the resonator connector length facilitates attenuation of a desired frequency of sound entering the resonator.
- 20. A method of controlling a variable tuned telescoping resonator, the method comprising the steps of:sensing an engine speed and transmitting said sensed engine speed to a programmable control module; matching said sensed engine speed with a stored resonator position value stored in a table in the programmable control module, wherein the table is created by determining a desired attenuation value for each engine speed to reach a desired sound pressure level, calculating an attenuation characteristic at each resonator position to determine the stored resonator position value at each resonator position, and matching the desired attenuation value at an engine speed with the attenuation characteristic of the resonator at each resonator position, thereby establishing the stored resonator position value for the engine speed; and adjusting at least one of a resonator connector length and a resonator volume according to the stored resonator position value.
US Referenced Citations (9)
Foreign Referenced Citations (1)
Number |
Date |
Country |
03064622 |
Mar 1991 |
JP |