JP3422022B2 - Noise suppression enclosure for engines. - Google Patents

Description

TECHNICAL FIELD The present invention relates generally to noise suppression in devices driven by engines, and more specifically to engine enclosures using passive and active acoustic suppression. A system for reducing noise emitted from a device.

BACKGROUND OF THE INVENTION Due to the ever-increasing use of equipment driven by engines, such as generator sets, environmental concerns are directed towards lowering and lowering the noise emitted by such equipment. . These generator sets are often used in areas where low noise is required. Such uses include construction sites in residential areas, carnivals and projector sets. Therefore, the market for acoustic suppression storage devices is increasing, and at present, the surcharges imposed on such storage devices are extremely high. For example, the price of some low noise enclosures is roughly comparable to the price of engine and generator packages that do not include enclosures.

An example of a storage device is disclosed in Howard R. Anderson et al., US Pat. No. 3,462,949, Aug. 26, 1969. This enclosure for a gas turbine engine comprises a silencer for the compressor of the engine and a compressor inlet housing specially shaped to create a uniform flow without turbulence and shunts. The enclosure comprises inlet duct means that bends the incoming air through a plurality of right angle bends, thereby quieting compressor noise.

Another example of an existing enclosure is Jack, dated January 31, 1978.
It is disclosed in US Pat. No. 4,071,009 to H. Kraina.
The enclosure includes an outer enclosure mounted around the engine and having a horizontally arranged hood and sidewalls. An inner enclosure is disposed within the outer enclosure and a horizontally disposed upper wall is vertically spaced between the top of the engine and the hood to form first and second air flow passages therebetween. ing. Air flow guide means are secured within each side wall defining a passage therebetween between them to the second air flow passage. The top and front walls of the hood, sidewalls and inner enclosure each have a layer of sound absorbing material secured thereto.

An example of an existing enclosure is Gerhard Th, March 6, 1979.
It is disclosed in US Pat. No. Re. 29,923 to ien et al. The soundproof casing is divided into two cooling air ducts which are separated from each other by at least one partition wall. One duct contains all of the engine's fuel supply members,
The second duct contains the exhaust system of the engine.

A noise reduction enclosure, as defined herein, reduces the noise emitted by equipment driven by the engine,
It provides the customer with a noise reduction enclosure at an economical price.

DISCLOSURE OF THE INVENTION A noise reduction enclosure according to one aspect of the present invention is adapted for use with an engine. The noise reduction enclosure includes a generally rectangular shaped housing that surrounds the engine. The storage device is divided into a duct portion and an engine portion that defines an engine compartment. The enclosure also includes a generally rectangular shaped housing surrounding the engine and is divided into a duct portion and an engine portion defining an engine compartment.
The housing further includes a plurality of molded sheet material skins (or skins) joined together. Each of the plurality of skins is relatively thin and has at least a portion having an inlet opening and an outlet opening. Each of the plurality of outer plates has an inner surface,
At least a portion of these interior surfaces are in close proximity to the engine. The enclosure further includes damping material and absorbent material fixedly attached to at least a portion of the inner surface. The enclosure also has an inlet duct having a predetermined length through which the cooling medium flows and which is positioned within the housing. The inlet duct interconnects the inlet opening through which the cooling medium enters and the engine compartment. The enclosure also has an outlet duct of a predetermined length through which the cooling medium flows and which duct is positioned in the housing and outside the inlet duct with respect to the engine. . The outlet duct interconnects the outlet opening through which the cooling medium exits with the engine compartment. The predetermined length of the outlet duct is longer than the predetermined length of the inlet duct.

An engine according to another aspect of the invention has a noise reduction enclosure positioned around it. The institution
It includes a cooling system having a heat exchanger coupled to the engine to dissipate heat generated by the engine. The heat exchanger has a coolant therein, the coolant being circulated through the heat exchanger and the engine by circulation means. A fan is coupled to be driven by the engine to dissipate heat from the coolant as the cooling medium through the heat exchanger flows through the heat exchanger. The noise reduction enclosure includes a generally rectangular shaped housing that surrounds the engine. The housing has an engine portion defining an engine compartment and an outer plate made of a plurality of sheet materials,
Each skin has an inner surface and at least a portion of these inner surfaces are proximate to the engine. The noise reduction enclosure further comprises damping and absorbing material fixedly attached to at least a portion of the inner surface. The housing further includes an inlet opening and an outlet opening in at least a portion of the sheet material skin. The enclosure also has an inlet duct having a predetermined length through which the cooling medium flows and which is positioned within the housing. The inlet duct interconnects the inlet opening through which the cooling medium enters and the engine compartment. The enclosure also has an outlet duct of a predetermined length through which the cooling medium flows and which duct is positioned in the housing and outside the inlet duct with respect to the engine. . The outlet duct interconnects the outlet opening through which the cooling medium exits with the engine compartment. The predetermined length of the outlet duct is longer than the predetermined length of the inlet duct.

A noise reduction enclosure according to another aspect of the invention is adapted for use with an engine. The engine emits noise and has a cooling medium flowing around the engine. The noise reduction enclosure includes a housing having an engine portion that defines an engine compartment and formed of a plurality of skins of sheet material. The housing has a generally rectangular shape and surrounds the engine. Each of the plurality of skins has an interior surface and at least a portion of the interior surface is proximate to the engine. The enclosure further includes damping material and absorbent material fixedly attached to at least a portion of the inner surface. Each of the plurality of skins is relatively thin and has at least a portion having an inlet opening and an outlet opening. The enclosure also has a length of inlet duct positioned within the housing. The inlet duct interconnects the engine compartment with the inlet opening through which the cooling medium enters. The enclosure also has an outlet duct of a length positioned within the housing and outside the inlet duct with respect to the engine. The outlet duct is
The outlet opening from which the cooling medium exits and the engine are interconnected. The inlet duct and the outlet duct have a substantially rectangular cross section. The predetermined length of the outlet duct is longer than the predetermined length of the inlet duct. The enclosure also includes means coupled to the housing to actively reduce noise.

Brief description of the drawings   FIG. 1 is a perspective view of the noise reduction structure.

  2 is a sectional view taken along the line 2-2 of FIG.

  FIG. 3 is a sectional view taken along line 3-3 of FIG.

  FIG. 4 is a sectional view taken along the line 4-4 of FIG.

Embodiment A noise reduction storage device 10 will be described with reference to FIGS. The enclosure 10 is intended for use with a driven device 12, such as a generator set or a compressor set.
Engine 14 and driven device 12 are conventional types and include a conventional fuel system, an air intake system, a control system (not shown), and a conventional exhaust system (only partially shown).

The noise reduction enclosure 10 includes a conventional skid or mounting base 30 having a fuel tank (not shown). organ
14 and driven device 12 are removably mounted to and detached from base 30 in the conventional manner. A housing 32 having a generally rectangular shape is positioned around the engine 14 and the driven device 12. The housing 32 has a plurality of inner surfaces 33, some of which are in close proximity to the engine 14 and the driven device 12. The housing 32 also includes a plurality of molded sheet material strips or skins 34 having a thickness of 2.5 mm to 4 mm. In this embodiment, the outer plate 34 has a thickness of 3.5 mm. A plurality of skins 34
Includes a pair of side walls 36, a pair of end walls 38, and a top wall 40. Each pair of side walls 36 has an inlet opening closer to one end wall 38.
Has 50. The entrance opening 50 is sandwich packaging,
It is covered by a perforated plate or grate 51 to prevent ingress of large items such as napkins or other airborne products. The end wall 38 remote from the inlet opening 50 has an outlet opening 52. The outlet opening 52 as well as the inlet opening 50
Perforated plate or grate 53 to prevent even larger items from entering
Is covered by. Alternatively, the housing 32 may include a structural underframe that is fixedly attached to the base 30, such as by welding. The underframe can be removably attached to the base 30 without changing the gist of the invention. The underframe can be formed by mounting a plurality of structural plates around the engine 14 and the device 12 to form a generally rectangular configuration. The plates may be angled, channel, or box-shaped in cross-section. If an underframe is used, the outer plate 34 is attached to the underframe 34 in the usual manner with bolts or tacks.

The noise reduction enclosure 10 is divided into a duct portion 54 and an engine portion 56. The engine portion 56 has an engine compartment 57 defined therein. The engine 14, driven device 12, and cooling system 60 are positioned within an engine compartment 57. The cooling system circulates a coolant (not shown) through the heat exchanger 62, a pair of bosses 64 connecting the heat exchanger 62 and the engine 14, and in this embodiment, the engine 14 and the heat exchanger 62. Institutions to let
And a circulation means 66 which is a pump 68 which is coupled to be driven by 14. The cooling system is also fan 72
The fan 72 also includes a plurality of blades 74, a tip 76 on each blade 74, and a conically shaped shroud 78 mounted to the engine 14. A fan 72 is drivingly coupled to the engine 14 and a shroud 78 is attached to the engine 14,
A relatively small gap is provided between the fan blades 74 and the shroud 78. The shroud 78 is a heat exchanger
62 and the interior of the outer plate 34 forming the outer shell of the engine compartment 57 of the housing 32 in a sealing relationship. Fan 72 directs a cooling medium, such as air, through heat exchanger 62 as indicated by arrow 82. Duct portion 54 includes an inlet duct 84 positioned within housing 32. A partition 85 is positioned within the inlet duct 84 and divides the inlet duct 85 into a pair of generally rectangular cross-section shaped inlet ducts. Each duct 84 separately interconnects one of the inlet openings 50 on each side wall 40 to a duct outlet 86 which is an outlet into the engine compartment 57. Cooling medium
82 is drawn through each inlet opening 50 by a fan 72 and flows from a curved portion 87 formed by a portion of the skin forming the inlet duct 84 to the inlet duct 84, near the end having the outlet opening 52 Guided into section 57 through duct outlet 86. The curved portion 87 formed in the portion of the skin 34 that forms the inlet duct 84 has a 90 ° bend in this embodiment. The cooling medium 82 is further guided by the fan 72 through the driven device 12, the engine 14, and the heat exchanger 62 to absorb heat from the coolant. Duct portion 54 also includes an outlet duct 88 positioned within housing 32. A partition 89 is positioned in the outlet duct 88 and divides the outlet duct 88 into a pair of outlet ducts 88 having a substantially rectangular cross section. Furthermore, the outlet duct 88 is
It is positioned with respect to the engine 14 outside the inlet duct 84. Each duct 88 has an outlet opening 52 provided at one end 38 and a duct inlet 90 positioned near the end 38 of the housing 32 opposite the duct outlet 86 of the inlet duct 84 to the engine compartment 57. And are connected to each other. Exit duct 88
Includes a curved portion 91 formed by and positioned within a portion of skin 34 forming outlet duct 88. The curved portion 91 has an angle of 90 ° and this embodiment is located near the duct inlet 90. Fan 72
Causes the cooling medium 82, which has a portion of the heat absorbed from the coolant through the heat exchanger 62, to be discharged from the outlet openings 52 through the duct inlets 90 in each outlet duct 88. Each inlet duct 84 has a predetermined length along which the cooling medium flows and has a substantially rectangular cross section substantially along its entire length. Each outlet duct 88 has a predetermined length along which the cooling medium 82 flows and has a substantially rectangular cross section substantially along its entire length. The predetermined length of each outlet duct 88 is longer than the predetermined length of each inlet duct 84. The predetermined length of each inlet duct 84 is equal to each other, and the predetermined length of each outlet duct 88 is equal to each other. A plurality of guide vanes 92 are positioned in the engine compartment 57 between the heat exchanger 62 and the duct inlet 90. The enclosure may separate engine portion 56 and duct portion 54 into two individual modules. The top wall 40 of the engine portion 56 is used to form the lower plate of the duct portion 54, but is left as the top wall of the engine portion 56 when divided into modules.

2, 3 and 4, a damping material 100 is fixedly attached, such as by gluing, to at least a portion of the plurality of molded sheet material pieces or skins 34. Braking material 100 is not attached to mounting base 30. In this embodiment, the damping material is highly effective in reducing seismic resonance in structures such as sheet material panels. The damping material is resistant to water and various solvents, acids and corrosive gases. The braking material used in this example is the Midwestern Regiona, Zip Code 60185, 1400 West Chicago Nuclear Drive, Illinois.
l HLBlac with Sales and Manufacturing Facility
It is commercially available from hford Inc. under the trade name “AQUAPLAS” ® and can be purchased in sheet form or in liquid form. In this example, the "AQUAPLAS" ® sheet has a thickness of about 6 mm to 10 mm. In this embodiment, the damping material 100 is attached only to the sidewall 36 of the noise reduction enclosure 10, the inner surface of the end wall 38, and the portion of the top wall 40 located within the engine compartment 57. About 80% of the side wall 36, the inner surface of the end wall 38, and the top wall 40 in the engine compartment 57 is covered by "AQUAPLAS" (registered trademark). Further, an absorbing material 102 such as acoustic foam or fiberglass is attached to the inner surfaces of "AQUAPLAS" (registered trademark) and the outer plate 34 by gluing or the like. The acoustic foam or fiberglass used in the engine compartment 57 has been treated to provide an oil resistant barrier. Further, the ends of the foam or fiberglass 102 are stuffed or molded along the corners and edges to make their oil resistant barriers. The foam or fiberglass 102 has a predetermined thickness of about 20 mm to 60 mm. In this example, the pre-determined thickness of most foam or fiberglass 102 used in engine compartment 57 is about 50.8 mm. In areas where space is restricted and the use of 50.8 mm thick foam or fiberglass 102 is prevented, about 25.4 mm thick foam or fiberglass is used. Each of the inlet duct 84 and the outlet duct 88 is
It has a layer of acoustic foam or fiberglass 102 fixedly attached to it. The foam or fiberglass 102 has a predetermined thickness of about 20 mm to 60 mm. In this example, the predetermined thickness of foam or fiberglass 102 mounted inside the duct is about 25.4 mm.

Noise reduction storage device to further reduce noise
10 includes means 120 for actively reducing noise. The means 120 for actively reducing noise includes a plurality of dynamic hardware 122. The dynamic hardware includes, for example, a speaker 124 mounted on the top wall 40 of each outlet duct 88. The means 120 also includes a plurality of microphones or sensors 126 positioned within each outlet duct 88. One of the plurality of sensors 126 is positioned near the duct inlet 90 of each outlet duct 88, and the second sensor 126 is positioned near the outlet opening 52. One end of a wiring harness 128 having a plurality of electric wires (not shown) has a plurality of sensors 126 and speakers 12.
Installed in 4 pairs. The other end of wiring harness 128 is connected to a control module or computer 130. Control module or computer 130 is sensor 1
The impulses from 26 can be evaluated, recorded, and resolved to determine the frequency to be emitted from speaker 124.

INDUSTRIAL APPLICATION Noise reduction enclosure 10 reduces noise emissions from conventional engine and generator packages by over 22 dB (A). When means 120 for actively reducing noise is added to the noise reduction enclosure 10, the noise emitted from the enclosure 10 is additionally reduced by an average of 1.4 dB (A). Further, when the means 120 for actively reducing noise is added to the noise reduction storage device 10, the noise emitted from the exit end of the storage device 10 is further reduced by 5 dB (A).

The operation will be described. Start engine 14. The air in the engine compartment 57 of the engine portion 56 of the enclosure 10 is mixed with fuel and used to operate the engine 14. When the engine 14 operates, the operation of the engine causes the cooling fan 72 to pass through the grid 51 and the inlet opening 50 on each side of the inlet duct 84 and the cooling medium (atmosphere)
Inhale 82. The inlet opening 50 is laterally positioned so that rain or snow does not naturally enter the inlet opening 50. The cooling medium 82 travels along a length of the inlet duct 84 and is diverted into the engine compartment 57 of the enclosure 10 by a curved portion 87 that helps reduce turbulence.

The cooling medium 82 travels along the outside of the generator set 12 and the engine 14 and absorbs heat from them. The cooling medium 82 is a shroud
It enters into 78, contacts the fan 72 and is passed through the heat exchanger 62. Enclosure 78, heat exchanger 62, and engine compartment 57
The sealing relationship between the inner surfaces of the skins 34 forming the increases the efficiency of the cooling system 60 and ensures effective cooling of the engine. The relative relationship between the shroud 78 and the tips 76 of the fan blades 74 further increases the flow of the cooling medium 82 through the heat exchanger 62. The cooling medium 82 that has passed through the heat exchanger 62 and has absorbed part of the heat from the coolant is discharged from the engine compartment 57 of the enclosure 10. The guide vanes 92 allow the heated cooling medium 82 to enter the duct.
From 90 to output duct 88. After entering the output duct 88, the cooling medium 82 again bends the curved portion 91 to reduce turbulence.
Be led to. As the cooling medium 82 travels along the output duct 88, at least some of the noise associated with travel is absorbed by the absorbent material 10.
The noise level absorbed by 2 and emitted from the output aperture 52 is reduced.

Means for actively reducing noise in the storage device 10 described above
When used with 120, additional actions and activities occur. The noise level entering the output duct 88 is detected by the sensor 126.
Monitored by. The impulse obtained from the sensor 126 is guided to the control module 130 along a plurality of electric wires in the wiring harness 128. The module 130 resolves the impulse and signals the speaker 124 in the exit duct 88 to emit acoustic waves into the exit duct 88. The acoustic wave from the speaker 124 cancels a part of the noise wave and reduces the noise emitted from the storage device 10. Exit opening in exit duct 88
A second sensor 126, located near 52, monitors the results of the canceling acoustic waves. The resulting pulses are directed to control module 130 along a plurality of wires in parity 128. Module 130 resolves these pulses and further modifies the acoustic waves emitted from speaker 124 to better cancel the noise emitted from enclosure 10.

The following list outlines the advantages and reasons why these advantages may be obtained. It has been found that a thickness of the skin 34 of typically 1.5 mm to 2.0 mm increases the transmission loss of a conventional enclosure and helps reduce the noise emitted from the enclosure. Actually, the noise attenuation is
The cost for increasing noise attenuation must be evaluated, although it increases with increasing thickness. Therefore, the degree of increase in cost versus damping for increasing thickness is evaluated, and the thickness of the outermost skin 34, which is the most cost effective at this time, is about 3 mm to
It was determined to be 3.5 mm. The positioning of the duct portion 54 above the engine compartment 57 formed by the engine portion minimizes the floor space required for the enclosure. Minimizing floor space is important because many devices are priced per unit floor area.
Experiments have shown that the maximum duct cross-section size determines the effective cutoff frequency of the passive damping, and the smaller ducts give higher cutoff frequencies. Therefore, a rectangular duct will give more damping than a rectangular duct with the same short sides. Therefore, two rectangular inlet ducts 84 and two rectangular outlet ducts 88 are adopted to obtain maximum acoustic suppression. The cross-sectional area of the duct used in this embodiment corresponds to the second fundamental vibration of the frequency of the fan 72 and the engine 14, resulting in a cutoff frequency of 360 Hz which can be sufficiently dampened with active and passive acoustic suppression. Has been selected. Furthermore, the passive duct damping is a function of length and the noise level is
Since traveling with the cooling medium 82 is higher than traveling with the cooling medium 82, the outlet side of the cooling medium 82 needs to be attenuated more than the inlet side of the cooling medium 82. Furthermore, since the fan 72, which is one of the noise sources, is closer to the outlet of the cooling medium 82, the outlet side of the cooling medium 82 needs to be attenuated more than the inlet side of the cooling medium 82. So the entrance duct 84
And the length of the outlet duct 88 has the above-described predetermined relationship.

Other aspects, objects and advantages of the invention will be apparent from the accompanying drawings, the foregoing description and the claims.

Front Page Continuation (72) Inventor Zam William Charles Illinois, Illinois 61615 Peoria North Sleepy Hello Road 10621 (56) References JP 62-80464 (JP, A) JP 63-5696 (JP, A) Actual development Sho 50-17635 (JP, U) Actual development Sho 57-20521 (JP, U) Actual development Sho 51-72639 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) F02B 77/13 F01P 11/12

Claims (21)

(57) [Claims] 1. A duct section (5) partitioned by a wall (40).
4) and a housing (32) made of a sheet material plate forming an engine compartment (56), in which the engine (14) is located.
And a driven device (12), and an inlet duct (84) for guiding cooling air to the engine compartment in the duct compartment.
And an outlet duct (8
8) is formed, and a damping member (100) for suppressing vibration of the housing and an absorbing material (102) for absorbing noise are attached to at least a part of the inner wall surfaces of the duct section and the engine section. A noise reduction enclosure (10) adapted for use with an engine (14), wherein the duct compartment (54) is located above the engine compartment (56). The engine compartment (56) is separated from the engine compartment (56) by the top wall (40), and the engine compartment (56) is located in the duct compartment (54).
On the side facing the top wall (40) of the inlet duct (84)
Are arranged so as to extend along the length direction of the engine compartment (56), an inlet opening (50) for taking in cooling air is formed at one end of the inlet duct (84), and the other end is the engine. Section (5
In the vicinity of one end in the lengthwise direction of 6), an opening (86) is formed in the upper part of the engine compartment so as to send cooling air into the engine compartment, and in the duct compartment (54), An outlet duct (88) is arranged above the inlet duct (84) so as to extend along substantially the entire length of the inlet duct, and one end of the outlet duct passes outside the one end of the inlet duct in the longitudinal direction. Is connected to the other end side of the engine compartment so that the total length of the outlet duct is made longer than the total length of the inlet duct. 2. A noise reduction storage device (1) according to claim 1.
0) and the inlet and outlet ducts (84, 88) are
A noise reduction enclosure (10) having a substantially rectangular cross-sectional shape substantially along the length of the duct (84, 88). 3. A noise reduction enclosure (10) adapted for use with an engine (14) having a cooling medium (82) flowing around a noise emitting engine (14), the engine compartment (10) comprising: 57) defining an engine portion (56) and comprising a housing (32) formed of a plurality of sheet material skins (34), said housing (32) generally enclosing the engine (14). Has a rectangular shape, each of the plurality of sheet material outer plates (34) has an inner surface, at least a portion of the inner surface is close to the engine (14), and the damping material (100 ) And an absorbent material (102) are fixedly attached, the skin (34) of the sheet material forming the housing (32) is relatively thin, and at least a portion of them has an inlet opening () therein. 50) and an outlet opening (52), the noise reduction enclosure (1 0) has a predetermined length and is positioned in the housing on the upper side of the engine compartment (57) so that the inlet opening (50) into which the cooling medium (82) enters and the engine compartment (57) are mutually connected. An inlet duct (84) connected to the cooling medium (82) having a predetermined length and located in the housing and above and outside the inlet duct (84) with respect to the engine (14). An outlet duct (88) interconnecting the exit opening (52) and the engine compartment (57)
The inlet duct (84) and the outlet duct (88) have a substantially rectangular cross-sectional shape, and the outlet duct (88) has a longitudinal end portion of the inlet duct (84). By being connected to the engine compartment (57) through the outside, the predetermined length thereof is longer than the predetermined length of the inlet duct (84), and the noise reduction storage device (10), A noise reduction storage device (10) comprising means (120) coupled to the housing (32) for actively reducing noise. 4. A noise reduction enclosure (10) according to any one of claims 1 to 3, wherein the housing (32) has a thickness of about 2.5 mm to 4 mm. A noise reduction enclosure (10) including a sheet metal skin (34). 5. The plurality of sheet metal skins (34) comprises about 3.
A noise reduction enclosure (10) according to claim 4, having a thickness of 5 mm. 6. A noise reduction enclosure (10) according to any one of claims 1 to 5, wherein the damping material (100) has a thickness of about 6 mm to 10 mm. "AQUAPLAS" (registered trademark) noise reduction storage device (1
0). 7. A noise reduction enclosure (10) according to any one of claims 1 to 6, wherein the absorbing material (102) has a predetermined thickness of about 20 mm to 60 mm. A noise reduction storage device (10) which is an acoustic foam having. 8. The noise reduction storage device (10) according to any one of claims 1 to 7, wherein the absorption material (102) has a predetermined thickness of about 20 mm to 60 mm. A noise reduction storage device (10) which is a fiberglass material having. 9. The noise reduction enclosure (10) of claim 6, wherein at least a portion of the absorbent material (102) has a predetermined thickness of about 25.4 mm. 10. The noise reduction enclosure (10) of claim 6, wherein at least a portion of the absorbent material (102) has a predetermined thickness of about 50.8 mm. 11. Any one of claims 1 to 10
The noise reduction storage device (10) according to the paragraph, wherein the inlet duct (84) is positioned in the inlet duct (84), and the inlet duct (84) is formed in a substantially rectangular shape. Including a partition (85) divided into ducts (84),
The outlet duct (88) is positioned in the outlet duct (88), and the outlet duct (88) has a substantially rectangular shape.
A noise reduction enclosure (10) including a partition (89) divided into a pair of outlet ducts (88). 12. Any one of claims 1 to 11
A noise reduction enclosure (10) according to paragraph 1, wherein the sheet material skin (34) forming the inlet duct (84) and the sheet material forming the outlet duct (88). The outer skin (34) includes a curved portion (87, 91), and the curved portion (87, 91) has an angle of 90 °. 13. Any one of claims 1 to 12
The noise reduction storage device (10) according to the above paragraph, wherein the cooling medium (82) is passed through the engine compartment to the engine compartment (57).
And the engine compartment (57) includes a plurality of turning vanes (92) for guiding the cooling medium (82) from the engine compartment (57) to the outlet duct (88).
0). 14. Any one of claims 1 to 13
A noise reduction enclosure (10) as recited in paragraph 1, wherein the sheet material skin (34) forming the housing (32) includes sidewalls (36) and the inlet opening (50) is A noise reduction enclosure (10) positioned within the sidewall (36). 15. Any one of claims 1 to 14
A noise reduction enclosure (10) according to claim 1, wherein the sheet material skin (34) forming the housing (32) includes an end wall (38) and the outlet opening (52). A noise reduction enclosure (10) positioned within the end wall (38). 16. A noise reduction storage device (10) is arranged so as to surround the engine (14), and the engine (14) is coupled to the engine (14) to generate heat generated by the engine (14). A cooling system (60) having a heat exchanger (62) for radiating heat, the heat exchanger (62) being circulated therein by a circulation means (66) through the heat exchanger (62) and the engine (14). The engine (14) has a coolant to be
A fan (72) which is coupled to be driven by the cooling medium (82) to force the cooling medium (82) to pass through the heat exchanger (62) and dissipate heat from the coolant flowing through the heat exchanger (62), The noise reduction enclosure (10) has a generally rectangular shape surrounding the engine (14) and defines an engine section (57) defining an engine compartment (57), each having an inner surface, A housing (32) including a plurality of molded sheet material skins (34), at least a portion of the inner surface of which is proximate to the engine (14), and a damping fixedly mounted on at least a portion of the inner surface A material (100) and an absorbent material (102), the housing (32) being provided in at least a portion of a skin (34) of sheet material, an inlet opening (50) and an outlet opening (52). The noise reduction storage device (10) has a predetermined length, The cooling medium (82) in the inside of the housing, and is formed in the housing above the engine compartment (57), and the cooling medium (82) enters the inlet opening (50) and the engine compartment ( 57) with an inlet duct (84) interconnecting it and a cooling medium (82) of a predetermined length in which the cooling medium (82) flows, into the housing and into the engine (14) An outlet duct (88) which is positioned above and outside the inlet duct (84) with respect to and interconnects the outlet opening (52) through which the cooling medium (82) exits with the engine compartment (57).
The outlet duct (88) is connected to the engine compartment (57) through the outside of the longitudinal end of the inlet duct (84) so that the predetermined length is An engine (14) characterized in that the duct (84) is longer than a predetermined length. 17. A fan (72) mounted to the engine (14), and a shroud (78) positioned around the fan (72) and mounted to the engine (14).
Institutions listed in (14). 18. The engine (14) of claim 17, wherein the shroud (78) has a conical shape. 19. The means for actively reducing noise (12)
0) includes a plurality of dynamic hardware (122), and each dynamic hardware (122)
Includes a speaker (124) attached to the outlet duct (88) for emitting a noise wave, and the noise wave emitted from the speaker (124) is emitted from the engine (14) and flows through the engine (14). The noise reduction enclosure (10) of claim 3, wherein noise carried by the cooling medium (82) is canceled. 20. The dynamic hardware (12
20. The noise reduction storage device (10) according to claim 19, wherein 2) also includes control means (130) for determining the level of the noise wave emitted from the speaker (124). 21. Any one of claims 4 to 15
An engine (14) in which the noise reduction storage device (10) described in No. 1 is arranged so as to surround the surroundings.