Acoustics – Sound-modifying means – Muffler – fluid conducting type
Reexamination Certificate
1998-10-21
2004-02-10
Nappi, Robert E. (Department: 2837)
Acoustics
Sound-modifying means
Muffler, fluid conducting type
C181S225000, C181S264000, C181S204000, C180S068100
Reexamination Certificate
active
06688424
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to an engine noise reduction device, and in particular, to an engine noise reduction device for a construction machine which further increases the quantity of air supplied to an engine compartment to prevent engine and equipment overheating.
BACKGROUND OF THE INVENTION
Conventionally, there have been various proposals regarding a noise absorbing device for reducing noise in an engine room. The following inventions are known as art close to the present invention:
(1) According to Japanese laid-open Patent No. 57-137616, cooling air discharged by a cooling fan of an engine passes through a sound deadening louver device of a radiator guard after cooling a radiator and is discharged into a space formed between the louver and a radiator silencer device. Part of the cooling air exhaust is discharged from an discharge port at the upper portion of the space, and the remaining portion of the exhaust is discharged to an engine air flow guiding passage of a dual structure connected to the lower portion of the space. A switch device is provided at the terminal end of the air flow guiding passage, and by operating an open-close plate, cooling air exhaust is returned to an engine room through an exit to enhance sound deadening effect, or cooling air exhaust is discharged to the outside to enhance cooling effect.
However, according to the above configuration, the sound deadening effect and the cooling effect are enhanced by operating the open-close plate in accordance with operational conditions; therefore, operation is troublesome. In addition, hot air is returned and circulated when the open-close plate is closed; thus, there is a disadvantage of reducing the cooling effect.
(2) According to Japanese Laid-open Patent No. 56-116520, each of a plurality of noise absorbing louvers is tilted so that the front edge thereof is higher than the rear edge thereof. As a result, a space between a pair of adjacent noise absorbing louvers form an air exhaust passage facing diagonally upward to the front of a vehicle. Thereby noisy air discharged from an engine room by a cooling fan is not discharged to the front of the vehicle but collides against the noise absorbing louvers once through a noise absorbing grille, and the noise and speed of the air is reduced. Thereafter, the noisy air is discharged along the passage to a portion above the vehicle. As a result, the noisy air discharged from the noise absorbing grille dose not scatter lightweight material such as fine coal, chips, or the like carried in the vehicle and placed in front of the noise absorbing grille.
However, according to the above configuration, each of the noise absorbing louvers is placed to face diagonally upward so that fine coal, chips, or the like are not scattered upward by the exhaust, but there is no particular advantage when it is applied to an air inlet portion. Especially it is difficult to apply this configuration to a vehicle with a structure which cannot secure a sufficient inlet area only with an air inlet portion in one direction and needs to provide air inlet portions in two different directions.
(3) According to Japanese Laid-open Utility Model No. 64-1150, both side portions of a plurality of noise absorbing louvers placed in parallel are respectively coupled with pins and the inclinations of the noise absorbing louvers are changed, thereby the space between adjacent louvers is adjustable. As a result, when a construction vehicle loses heat balance during operation, flow resistance of cooling air can be reduced by increasing the space between the noise absorbing louvers. When noises are to be reduced, the space can be reduced by tilting the noise absorbing louvers, and engine noises can be released upward.
However, according to the above configuration, it is necessary to operate the noise absorbing louvers respectively to reduce engine noise or to enhance engine cooling, thus the system is inconvenient. In addition, as in the previous invention, it is difficult to apply this configuration to air inlet portions in two different directions.
(4) Japanese Laid-open Patent No. 6-144022 provides a configuration of a traveling working vehicle in which exhaust from an opening portion of a radiator is discharged from an engine bonnet. A splitter sound deadening device is placed in close contact with the opening portion of the radiator and is attached at the engine bonnet side to prevent a cooling air flow from circulating in the engine bonnet. Moreover, the radiator is placed so that the axis of a cooling fan is at a position higher than the axis of a cooling pump so that the exhaust from the opening portion of the radiator is discharged lower than the splitter sound deadening device.
According to the above configuration, the splitter sound deadening device is in close contact with the opening portion of the radiator and is attached at the engine bonnet side to prevent a cooling air flow from circulating in the engine bonnet; therefore, it is difficult to apply this configuration to air inlet portions to take air in from two different directions.
Recently, ultra-small, revolving-type hydraulic shovels, which can revolve within the width of a crawler belt, are mainly used in operational sites. For these hydraulic shovels, the size of the upper revolving superstructure is reduced. Consequently, the volume of an engine room which houses an engine, a radiator, a fan, hydraulic instruments, and the like is decreased. In
FIGS. 25 and 26
, an upper revolving superstructure
151
is composed of a working machine
152
, a driver's cabin
153
, an engine room
111
, and the like, and can revolve within the width of a crawler belt
155
. In this downsized ultra-small, revolving-type hydraulic shovel
150
, a single intake port for supplying cooling air flow to cool a radiator (not illustrated) housed in the inner side of the engine room
111
and an engine (not illustrated) is too limited, and an insufficient quantity of cooling air flow would be supplied. Therefore, a device
110
for supplying air to an engine room having a plurality of air intake ports
122
and
127
supplies cooling air flow to the radiator to cool the engine. As a result, for a plurality of air intake ports
122
and
127
, air is mainly supplied through a counterweight
121
(composing the engine room
111
) having the intake port
122
, and a shortage amount is supplied through the air intake port
127
extending through an engine hood
126
at the upper side of the engine room
111
. Alternatively, air is mainly supplied through the counterweight
121
, and a shortage amount is supplied from a space at an upper revolving superstructure frame
112
at the lower side of the engine room
111
.
However, in the hydraulic shovel
150
or the like, it is found that even if a plurality of intake ports
122
and
127
(which intersect at a right angle) are provided, the quantity of air supplied is not increased. Explaining, for example, with reference to
FIG. 19
, a change in the quantity of intake air is achieved by changing an opening area An of the auxiliary hood inlet port
127
, provided at an engine hood
126
, to take in the shortage air flow amount, while an opening area Ac at the major counterweight inlet port
122
, provided at the counterweight
121
, is fixed. As a result, as shown in
FIG. 22
, it is found that if auxiliary air quantity Va from the auxiliary hood inlet port
127
is increased, major air quantity Vm from the major counterweight inlet port
122
decreases following the increase, and total air quantity Vc as a whole increases only a little. On the other hand, if the opening area An of the auxiliary hood inlet port
127
is fixed and the opening area Ac of the major counterweight inlet port
122
is changed, the same result is obtained, specifically, the total air quantity Vc as a whole increases only a little. The reason for the above result is considered to be that the air from the major counterweight inlet port
122
and the air from the auxiliary hood inlet port
127
interfere with
Ikeda Masahiro
Imamura Kazuya
Nakada Kuniaki
Komatsu Ltd.
Martin Edgardo San
Nappi Robert E.
Sidley Austin Brown & Wood LLP
LandOfFree
Noise absorbing device and device for taking air into engine... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Noise absorbing device and device for taking air into engine..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Noise absorbing device and device for taking air into engine... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3338573