JP7506561B2 - Air intake duct structure for engine work equipment - Google Patents

Description

The present invention relates to an intake duct structure for an engine-operated machine that houses an engine in a housing.

Conventionally, examples of this type of engine working machine include engine generators and engine welding machines that use engine power to drive a generator, and engine compressors that use engine power to drive a compressor. In these engine working machines, the generator and other components are housed in a housing together with the engine to reduce noise during operation. The housing is formed so that the engine and generator are not exposed to enhance the noise reduction effect, but since it houses the engine, it is necessary to provide the housing with an intake duct to draw in air to be supplied to the engine.

The engine work machine disclosed in Patent Document 1 has an intake port formed in a door or side wall, and an intake duct extending upward is provided on the inside of this intake port. Within the air flow path formed inside the intake duct, multiple partition plates that rectify the air flowing through the air flow path are arranged parallel to each other. Patent Document 1 describes that the partition plates suppress the generation of turbulence and reduce wind noise, and that dividing the air flow paths in the intake duct with the partition plates to narrow each flow path makes it difficult for noise inside the machine to escape to the outside.

Japanese Patent No. 6076213

However, when a partition plate is placed in the intake duct, the cross-sectional area of the partition plate and the cross-sectional area of the passage in the intake duct are reduced. In Patent Document 1, it is assumed that multiple partition plates are placed, so the cross-sectional area of the passage in the intake duct is greatly reduced, which may result in a decrease in the amount of intake air and a decrease in the cooling performance inside the aircraft. In particular, in Patent Document 1, in order to make it difficult for noise inside the aircraft to escape to the outside, the air flow path in the intake duct is divided into multiple parts and the cross-sectional area of each flow path is actively narrowed. However, in such a narrow air flow path, it is thought that the intake resistance in each air flow path increases, making it easy for the intake amount to decrease, and it is also thought that the flow speed in each air flow path increases, making it easy for wind noise to occur. In order to avoid this, it is sufficient to make the intake duct larger, but trying to make the intake duct larger leads to an increase in the size of the housing, which is not desirable.

In addition, in Patent Document 1, the partition is placed inside the intake duct and does not face the cabin, so the partition has little effect in directly absorbing cabin noise.

The present invention was made in consideration of these points, and its purpose is to efficiently reduce external noise while ensuring a sufficient amount of air is drawn into the aircraft through the intake duct, improving cooling performance.

To achieve the above objective, in the present invention, sound-absorbing panels are arranged so that the cross-sectional area of the passage in the intake duct is not significantly reduced and so that noise inside the aircraft can be directly absorbed.

The first invention is an intake duct structure for an engine working machine having an engine, a driven machine driven by the engine, and a housing that houses the engine and the driven machine, characterized in that the housing is formed with an intake port for drawing in outside air, and inside the housing are provided an intake duct component that forms an intake air passage connected to the intake port, and a plurality of sound absorbing plates that are outside the intake air passage and guide the air discharged from the intake air passage into the housing in a predetermined direction.

According to this configuration, air sucked in through the intake port of the housing flows through the intake air passage formed by the intake duct components and is discharged from the intake air passage into the housing. The air discharged from the intake air passage into the housing is guided in a predetermined direction by multiple sound absorbing plates and is supplied to necessary locations such as the engine and driven machinery, and is used as engine intake and cooling air for each part.

The multiple sound-absorbing panels are positioned to guide air outside the intake air passage, so all or most of the sound-absorbing panels are positioned outside the intake air passage. This ensures that the cross-sectional area of the intake air passage is not significantly reduced by providing multiple sound-absorbing panels, and a sufficient amount of air is taken into the aircraft.

In addition, since all or most of the sound-absorbing panels are located outside the intake air passage, noise emitted from the engine and driven machine is directly absorbed by the sound-absorbing panels. In addition, since all or most of the sound-absorbing panels are located outside the intake air passage, the area that can be absorbed by the sound-absorbing panels can be increased, and the sound-absorbing effect is enhanced. Therefore, the sound pressure level of noise inside the housing is reduced, and noise radiated from inside the housing to the outside is efficiently reduced. This achieves low noise not only on the side of the housing where the sound-absorbing port is formed, but all around the housing. The sound-absorbing panels can also provide a straightening effect inside the intake duct.

All of the sound-absorbing panels may be located outside the intake air passage, or most of the sound-absorbing panels may be located outside the intake air passage and the remaining parts may be located inside the intake air passage. Even if only a part of each sound-absorbing panel is located inside the intake air passage, it is possible to ensure a sufficient amount of air intake into the aircraft and to reduce noise.

The multiple sound-absorbing plates may be arranged at intervals from each other in a direction intersecting the air flow direction, or may be arranged side by side in the air flow direction. In addition, since the multiple sound-absorbing plates only need to be able to guide the air discharged from the intake air passage into the housing in a specified direction, all of the sound-absorbing plates may be arranged outside the intake duct component, or a part of each sound-absorbing plate may be arranged inside the intake duct component.

The second invention is characterized in that the sound absorbing plate is arranged to extend in the direction of extension to the downstream side of the intake air passage.

With this configuration, air discharged into the housing from the downstream side of the intake air passage is smoothly guided in the extension direction of the intake air passage by the sound absorbing plate, so that it can be reliably supplied to the desired area.

The third invention is characterized in that the sound absorbing plate is arranged to extend in a direction intersecting the downstream extension direction of the intake air passage.

With this configuration, air discharged into the housing from the downstream side of the intake air passage is guided by the sound absorbing plate in a direction different from the extension direction of the intake air passage, so that cooling air can be supplied to a part different from the extension direction of the intake air passage, improving cooling performance.

The fourth invention is characterized in that the intake port is formed in a door of the housing, the intake duct component includes first and second plate portions fixed to the inner surface of the door and extending in the flow direction of the intake air passage, arranged to face each other, a third plate portion extending from the first plate portion to the second plate portion and arranged to face the inner surface of the door, and a blocking plate portion blocking the upstream end of the intake air passage, and the intake air passage is formed by the first plate portion, the second plate portion, the third plate portion, the blocking plate portion, and the inner surface of the door.

With this configuration, if there is free space near the door inside the housing, the free space can be used effectively by placing the intake duct components in that space. In this case, the intake air passage can be formed using the inner surface of the door, making it even more compact.

The fifth invention is characterized in that the sound-absorbing plate is fixed to the inner surface of the door and protrudes from the inner surface of the door into the housing.

With this configuration, the intake duct components and sound absorbing panel are fixed to one door, making it possible to effectively utilize the space near the door inside the housing.

The sixth invention is characterized in that the sound-absorbing board is fixed to an upper cover provided on the upper part of the housing or to a frame provided on the lower part of the housing.

With this configuration, by fixing the sound-absorbing board to the upper cover, the air discharged from the intake air passage into the housing can be guided further upward. Also, by fixing the sound-absorbing board to the lower frame, the air discharged from the intake air passage into the housing can be guided further downward.

The seventh invention is characterized in that the intake port is formed in the side wall of the housing, the intake duct component includes first and second plate portions fixed to the inner surface of the side wall and extending in the flow direction of the intake air passage, arranged to face each other, a third plate portion extending from the first plate portion to the second plate portion and arranged to face the inner surface of the side wall, and a blocking plate portion blocking the upstream end of the intake air passage, and the intake air passage is formed by the first plate portion, the second plate portion, the third plate portion, the blocking plate portion, and the inner surface of the side wall.

With this configuration, if there is free space near the side wall inside the housing, the free space can be used effectively by placing the intake duct components in that space. In this case, the intake air passage can be formed using the inner surface of the side wall, making it even more compact.

The eighth invention is characterized in that the sound absorbing plate is positioned downstream from the downstream end of the intake air passage.

With this configuration, the entire sound-absorbing panel is positioned outside the intake air passage, so the cross-sectional area of the intake air passage is not reduced by the sound-absorbing panel, ensuring a sufficient amount of air being drawn into the aircraft. In addition, the noise generated by the engine and driven machinery can be directly absorbed over a wide area of the sound-absorbing panel, improving sound-absorbing performance.

In the ninth aspect of the invention, the sound-absorbing board is equipped with a sound-absorbing material made of foam, so noise can be absorbed efficiently.

In the tenth aspect of the present invention, the intake duct components form an intake air passageway that extends upward from the intake port, making it difficult for rainwater, etc. to enter the intake air passageway.

In the eleventh aspect of the invention, the multiple sound-absorbing panels are approximately parallel to each other, so that the air discharged into the housing can be reliably guided in the desired direction.

In the twelfth invention, the sound-absorbing plate guides the air discharged from the intake air passage into the housing toward the part to be cooled inside the housing, so that the part to be cooled can be cooled reliably.

According to the present invention, multiple sound absorbing plates are provided outside the intake air passage formed by the intake duct components to guide air in a predetermined direction, so that the intake duct components can ensure a sufficient amount of air is drawn into the aircraft, improving cooling performance while efficiently reducing external noise.

1 is a side view of an engine-driven working machine according to a first embodiment of the present invention. FIG. FIG. 2 is a perspective view of the door according to the first embodiment, seen from the inside. 3 is a cross-sectional view taken along line III-III in FIG. 1. 4 is a cross-sectional view taken along line IV-IV in FIG. 1. FIG. 11 is a side view of a door according to a modified example of the first embodiment. FIG. 11 is a perspective view of a door according to a modified example of the first embodiment, as viewed from the inside. 7 is a cross-sectional view taken along line VII-VII in FIG. 5. 8 is a cross-sectional view taken along line VIII-VIII in FIG. 5 . FIG. 6 is a side view of an engine-driven working machine according to a second embodiment of the present invention. 10 is a cross-sectional view taken along line XX in FIG. 9. FIG. 11 is a side view of an engine-driven working machine according to a third embodiment of the present invention. This is a cross-sectional view taken along line XII-XII in Figure 11. FIG. 11 is a perspective view showing an intake duct structure according to a fourth embodiment of the present invention. FIG. 11 is a perspective view showing an intake duct structure according to a fifth embodiment of the present invention. FIG. 13 is a perspective view showing an intake duct structure according to a sixth embodiment of the present invention. FIG. 13 is a perspective view showing an intake duct structure according to a seventh embodiment of the present invention.

The following describes in detail an embodiment of the present invention with reference to the drawings. Note that the following description of the preferred embodiment is essentially merely an example and is not intended to limit the present invention, its applications, or its uses.

(Embodiment 1)
1 is a side view of an engine-driven working machine 1 according to a first embodiment of the present invention. The engine-driven working machine 1 is a portable power generating device including an engine E, a generator G as a driven machine driven by the engine E, and a housing 10 that houses the engine E and the driven machine G. The driven machine of the engine-driven working machine 1 may be, for example, a compressor or a pump other than the generator G. The engine-driven working machine 1 may also be a welding machine or the like equipped with the generator G, or may be a working machine equipped with various other driven machines driven by the engine E.

A horizontally extending frame 11 is provided at the bottom of the engine work machine 1, and this frame 11 is also a component of the engine work machine 1. An engine E and a generator G are attached to the frame 11. Although not shown, various auxiliary equipment is also attached to the frame 11.

The driving force output from the crankshaft (not shown) of the engine E is input to the generator G. The engine E and the generator G are arranged side by side in the crankshaft direction, but this arrangement is not limited to this. In the explanation of this embodiment, the front and rear are defined as shown in FIG. 1, and an example is explained in which the generator G is arranged on the rear side of the engine E, but this is a definition only for the convenience of explanation, and either side may be the front or the rear in the actual usage state or during manufacturing.

Engine E is equipped with a radiator R, a cooling fan F, and an air cleaner A. Radiator R is located in front of engine E and is a heat exchanger for cooling engine coolant. Engine coolant circulates through radiator R when engine E is operating. Cooling fan F is located behind radiator R and is for supplying cooling air to radiator R. Cooling fan F can be driven by engine E or a motor (not shown). Air cleaner A is located above generator G and is for filtering air drawn into engine E. Air cleaner A is provided with an intake port A1 that opens toward the front.

Since the engine E and the generator G are aligned in the front-to-rear direction, the housing 10 has a box-like shape that is longer in the front-to-rear direction than in the left-to-right direction (width direction). The housing 10 includes side walls 12, a door 13, and an upper cover 14. The side walls 12 extend upward from the upper part of the frame 11 and are formed to surround the periphery of the engine E and the generator G. The upper cover 14 is provided on the upper part of the side walls 12. This upper cover 14 covers the upper part of the space surrounded by the side walls 12.

The door 13 is provided on the side wall 12. That is, a rectangular opening 12a that is opened and closed by the door 13 is formed in the middle of the front-rear direction of the portion of the side wall 12 that extends in the front-rear direction. The opening 12a is located to the side of the engine E, and opens at a position where repairs and maintenance work on the engine E etc. can be easily performed. The lower edge of the opening 12a is located near the top of the frame 11, and the upper edge of the opening 12a is located near the bottom of the upper cover 14. This ensures that the vertical dimension of the opening 12a is long, and the opening area can be increased.

The position of the opening 12a is not limited to the above-mentioned position, but may be near the front or rear of the side wall 12. The size and shape of the opening 12a can also be set arbitrarily.

The door 13 has a rectangular shape that can completely close the opening 12a of the side wall 12. As shown in FIG. 2, the door 13 has a door body plate portion 13a that corresponds to the shape of the opening 12a, and a peripheral plate portion 13b that protrudes from the peripheral edge of the door body plate portion 13a toward the inside of the housing 10. When the door 13 is closed, the peripheral plate portion 13b is formed to fit into the opening 12a of the side wall 12. The peripheral plate portion 13b may be omitted.

A hinge (not shown) is provided at one edge of the door 13 to rotatably support the door 13 on the side wall 12. In this embodiment, the hinge is provided at the front edge or rear edge of the door 13. The mounting structure of the door 13 to the side wall 12 is not limited to a structure using a hinge, and may be a structure that allows the door 13 to be detachably attached to the side wall 12. The inside of the door 13 is the side facing the inside of the housing 10, and may also be called the back side. The outside of the door 13 is the side facing the outside of the housing 10, and may also be called the front side. The door 13 may be made of, for example, a steel plate.

The engine work machine 1 is provided with an intake duct structure 20. The intake duct structure 20 is a structure for introducing air from outside the housing 10 into the housing 10, and is characterized by the fact that it can reduce noise emitted outside the housing 10 while ensuring a large intake volume. The air introduced into the housing 10 includes air to be sucked into the engine E, as well as air for cooling the engine E and air for cooling the generator G.

The air intake duct structure 20 includes an air intake port 21 formed in the door 13, an air intake duct component 22 provided on the inside of the door 13, and a sound absorbing plate 23. The air intake port 21 is formed to penetrate the door body plate portion 13a of the door 13 in the front-to-back direction, and is an opening for drawing in air outside the housing 10. In this embodiment, the air intake port 21 is located below the vertical center of the door 13, but the air intake port 21 may be formed in the vertical center of the door 13 or above the vertical center of the door 13.

The air intake 21 is longer in the front-to-rear direction than in the up-down direction, giving it a long shape in the front-to-rear direction. A lattice 21a can be provided inside the air intake 21 to prevent foreign objects from entering, but this lattice 21a may be omitted. Providing the lattice 21a divides the air intake 21 into multiple parts, but these multiple openings may be treated as a single air intake 21, or multiple air intakes 21 may be formed in the door 13 with spaces between them. The air intake 21 is positioned below and forward of the air intake A1 of the air cleaner A.

2 and 3, the intake duct component 22 is provided inside the housing 10 and is a component for forming the intake air passage 24 connected to the intake port 21. The material of the intake duct component 22 may be the same as that of the door 13, for example, or may be different. The intake duct component 22 includes a front plate portion (first plate portion) 22a, a rear plate portion (second plate portion) 22b, an inner plate portion (third plate portion) 22c, and a blocking plate portion 22d. These plate portions 22a, 22b, 22c, and 22d may be integrally molded, for example, by press processing, or may be integrated by joining separate members. The intake air passage 24 is formed by the front plate portion 22a, the rear plate portion 22b, the inner plate portion 22c, the blocking plate portion 22d, and the inner surface of the door 13.

The front plate portion 22a and the rear plate portion 22b are fixed to the inner surface of the door body plate portion 13a of the door 13, protrude toward the inside of the housing 10, and extend in the vertical direction, which is the flow direction of the intake air passage 24. The front plate portion 22a and the rear plate portion 22b are arranged at a distance from each other in the front-rear direction and arranged to face each other in the front-rear direction. The front plate portion 22a is arranged in front of the front edge of the intake port 21, and the rear plate portion 22b is arranged behind the rear edge of the intake port 21, so that the intake port 21 is located between the front plate portion 22a and the rear plate portion 22b. The distance between the front plate portion 22a and the rear plate portion 22b corresponds to the dimension of the intake air passage 24 in the front-rear direction. The front plate portion 22a and the rear plate portion 22b may be parallel, or may be spaced apart from each other in the front-rear direction, for example, so that the distance between them increases toward the top, or decreases toward the top.

The inner plate portion 22c extends from the edge of the front plate portion 22a on the inside of the housing 10 to the edge of the rear plate portion 22b on the inside of the housing 10 and also extends in the vertical direction. The inner plate portion 22c is arranged to face the inner surface of the door body plate portion 13a with a predetermined gap therebetween. The gap between the inner surface of the door body plate portion 13a and the inner plate portion 22c corresponds to the left-right (depth) dimension of the intake air passage 24. In this embodiment, the front-rear dimension of the intake air passage 24 is set longer than the left-right dimension, and the cross-sectional shape of the intake air passage 24 is a flat shape that is long in the front-rear direction. The front-rear dimension and the depth dimension of the intake air passage 24 may be approximately the same, or the depth dimension may be longer. The inner plate portion 22c and the door body plate portion 13a may be parallel, and for example, the gap may be wider as they go up, or the gap may be narrower as they go up.

The blocking plate portion 22d is for blocking the upstream end (lower end) of the intake air passage 24. The front edge of the blocking plate portion 22d is connected to the lower edge of the front side plate portion 22a, and the rear edge of the blocking plate portion 22d is connected to the lower edge of the rear side plate portion 22b. Furthermore, the blocking plate portion 22d is joined to the door body plate portion 13a and is connected to the lower edge of the inner side plate portion 22c. This blocks the lower end of the intake duct component 22, and the air sucked in from the intake port 21 flows only upward.

The upper end of the intake duct component 22 is the downstream end of the intake air passage 24, and is entirely open to form an air exhaust port 22e. Since the intake air passage 24 extends vertically and the exhaust port 22e opens upward, the air in the intake air passage 24 is blown upward from the exhaust port 22e. The exhaust port 22e has a shape that is long in the front-to-rear direction, similar to the cross-sectional shape of the intake air passage 24.

The sound absorbing plate 23 is a member that guides the air discharged from the intake air passage 24 into the housing 10 in a predetermined direction outside the intake air passage 24, and absorbs noise inside the housing 10. In this embodiment, an example in which first to fourth sound absorbing plates 23A to D are provided as the sound absorbing plates 23 will be described, but the number of sound absorbing plates 23 may be any number of two or more.

The first to fourth sound absorbing plates 23A to D are fixed to the inner surface of the door body plate portion 13a and protrude from the inner surface toward the inside of the housing 10. As shown in FIG. 4, the first to fourth sound absorbing plates 23A to D have a plate material 230 made of a hard material such as metal and a sound absorbing material 231 attached to both sides of the plate material 230. The sound absorbing material 231 can be a porous material made of a resin such as urethane foam. The sound absorbing material 231 may be provided on the entire surface of the plate material 230 or only on a part of it. The sound absorbing material 231 may be provided on only one side of the plate material 230. In addition, the sound absorbing plate 23 may be formed into a hollow plate shape and a structure that attenuates sound energy using, for example, the principle of Helmholtz resonance may be adopted. That is, a number of openings are formed on the surface of a hollow sound-absorbing board, the openings are connected to the internal space of the sound-absorbing board, and the sound that enters the internal space through the openings is resonated in the internal space, thereby reducing noise. In this case, the sound-absorbing board 23 may be made of a resin material, or may be a structure having a number of air bubbles. The above-mentioned structural example of the sound-absorbing board 23 is just one example, and boards with other sound-absorbing effects can also be used as the sound-absorbing board 23. Also, each of the first to fourth sound-absorbing boards 23A to D in this embodiment may be made of a single plate material, or may be made by stacking multiple plate-like members.

In addition to the plate material 230, the porous material may be attached to the inner surface of the door 13, or to the outer or inner surface of the intake duct component 22. By attaching the porous material to the inner surface of the door 13 or the outer or inner surface of the intake duct component 22, the effect of reducing internal noise can be increased together with the sound-absorbing plate 23.

1 and 2, the first to fourth sound absorbing plates 23A-D extend obliquely. That is, since the intake air passage 24 extends from bottom to top, the extension direction of the intake air passage 24 to the downstream side is upward, but in this embodiment, the first to fourth sound absorbing plates 23A-D are inclined so that they are positioned further back as they go up, so they are arranged to extend in a direction intersecting the extension direction of the intake air passage 24 to the downstream side. This allows the air introduced from the outside to be guided toward the intake port A1 of the air cleaner A. The air cleaner A is a cooled part that supplies low-temperature air introduced from the outside. Examples of the cooled part include the engine E main body, the radiator R, and the cooling fan F. In the case of an engine equipped with a supercharger (not shown), the supercharger and the intercooler are also cooled parts. The direction and length of the sound absorbing plate 23 can be set so as to guide the air introduced from the outside to these cooled parts. Additionally, the first to fourth sound absorbing panels 23A to 23D may be positioned so that the higher they are, the further forward they are.

The first to fourth sound absorbing plates 23A-D are parallel to each other, but they do not have to be parallel. For example, the spacing between the first to fourth sound absorbing plates 23A-D may be wider or narrower as they go up. Also, in this embodiment, the first sound absorbing plate 23A is the longest and the fourth sound absorbing plate 23D is the shortest, but this is not limiting, and all of the sound absorbing plates 23A-D may be the same length, or the first sound absorbing plate 23A may be the shortest.

The first to fourth sound absorbing plates 23A to 23D are disposed downstream of the downstream end (exhaust port 22e) of the intake air passage 24. As a result, all of the first to fourth sound absorbing plates 23A to 23D are disposed outside the intake air passage 24, so the cross-sectional area of the intake air passage 24 is not reduced by the sound absorbing plates, and a sufficient amount of air is taken into the aircraft. In addition, the noise generated by the engine E and the generator G can be directly absorbed over a wide range of the sound absorbing plates 23A to 23D, improving the sound absorbing performance. The sound absorbing plates 23A to 23D do not all need to extend in the same direction, and may extend in different directions from each other. For example, the first sound absorbing plate 23A and the second sound absorbing plate 23B may extend forward, while the third sound absorbing plate 23C and the fourth sound absorbing plate 23D may extend backward. This allows air to be guided in two directions.

Although not shown, only the lower parts of the first to fourth sound absorbing panels 23A to 23D may be disposed within the intake air passage 24. In this case, the cross-sectional area of the intake air passage 24 can be secured to be larger than that of Patent Document 1, so that a sufficient amount of air can be sucked into the aircraft.

Also, as in the modified example shown in Figs. 5 to 8, the sound absorbing plate 23 may be arranged to extend in the extension direction (upward) of the intake air passage 24 downstream. In this modified example, the dimension of the intake air passage 24 in the front-rear direction is set longer than that of the embodiment shown in Fig. 1, but may be the same as that of the embodiment shown in Fig. 1. In this modified example, the sound absorbing plate 23 may be any number of plates equal to or greater than two. Since the sound absorbing plate 23 extends in the vertical direction, the air discharged from the intake air passage 24 into the housing 10 can be guided upward. For example, when a large air flow is formed in the housing 10 by the cooling fan F, the air discharged from the intake air passage 24 can be guided by the sound absorbing plate 23 so as to follow the air flow in the housing 10 without impeding the air flow in the housing 10. Such an air guide direction can be set by the shape and position of the sound absorbing plate 23.

(Effects of the embodiment)
As described above, according to this embodiment, air sucked in through the intake port 21 of the housing 10 flows through the intake air passage 24 formed by the intake duct component 22, and is discharged from the intake air passage 24 into the housing 10. The air discharged from the intake air passage 24 into the housing 10 is guided in a predetermined direction by the sound absorbing plate 23 and supplied to necessary locations of the engine E and the generator G, and is used as intake air for the engine E and cooling air for each portion.

The sound absorbing plate 23 is positioned so as to guide air outside the intake air passage 24, so all or most of the sound absorbing plate 23 is positioned outside the intake air passage 24. As a result, the cross-sectional area of the intake air passage 24 is not significantly reduced by providing the sound absorbing plate 23, and a sufficient amount of air is taken into the aircraft.

In addition, since all or most of the sound absorbing plate 23 is disposed outside the intake air passage 24, the noise emitted from the engine E and the generator G is directly absorbed by the sound absorbing plate 23. This reduces the sound pressure level of the noise inside the housing 10, and efficiently reduces the noise radiated from the housing 10 to the outside. This achieves low noise not only on the side of the housing 10 where the sound absorbing port 21 is formed, but all around the housing 10.

In addition, if there is free space near the door 13 inside the housing 10, the free space can be used effectively by placing the intake duct component 22 in that space. In this case, the intake air passage 24 can be formed using the inner surface of the door 13, making it even more compact.

(Embodiment 2)
9 and 10 show an engine-driven working machine 1 according to a second embodiment of the present invention. This second embodiment differs from the first embodiment in that a sound absorbing panel 23 is fixed to the upper cover 14. In the following, the same parts as those in the first embodiment are given the same reference numerals and their explanation is omitted, and only the different parts will be explained.

In this second embodiment, the intake duct component 22 is located higher than in the first embodiment, and the upper end of the intake duct component 22 is closer to the top cover 14. The layout of the intake duct component 22 may be determined in this way depending on the arrangement of the internal equipment of the housing 10. For this reason, the door 13 does not have enough space to attach the sound absorbing board 23, so the sound absorbing board 23 is fixed to the top cover 14. By fixing the sound absorbing board 23 to the top cover 14, the air discharged from the intake air passage 24 into the housing 10 can be guided further upward.

As shown in FIG. 10, the sound absorbing plate 23 protrudes from the inner surface of the upper cover 14 into the housing 10 and extends in the vertical direction. Air discharged from the intake air passage 24 into the housing 10 is guided upward by the sound absorbing plate 23, and then hits the upper cover 14 and flows toward the back of the housing 10. This creates an air flow that flows toward the back at the top of the housing 10.

In the second embodiment, the number of sound-absorbing panels 23 may be any number of panels equal to or greater than two. The sound-absorbing panels 23 may also extend in a direction intersecting the direction of extension of the intake air passage 24 downstream, i.e., diagonally forward or diagonally backward.

Therefore, according to this embodiment 2, as in embodiment 1, it is possible to efficiently reduce external noise while ensuring a sufficient amount of air intake into the aircraft through the intake duct component 22, improving cooling performance.

(Embodiment 3)
11 and 12 show an engine working machine 1 according to a third embodiment of the present invention. This third embodiment differs from the first embodiment in that air is supplied downward inside the housing 10 and that a sound absorbing panel 23 is fixed to the frame 11. In the following, the same parts as those in the first embodiment are given the same reference numerals and their explanation is omitted, and only the different parts will be explained.

In this embodiment 3, as shown in FIG. 12, the intake air passage 24 extends upward, and then is bent and extends downward. The intake duct component 220 of embodiment 3 has a front plate portion 220a, a rear plate portion 220b, an inner plate portion 220c, and a closing plate portion 220d similar to those of embodiment 1, and further has an upper plate portion 220e at the top. The upper plate portion 220e is a member for closing the upper end portion of the intake duct component 220.

Furthermore, the intake duct component 220 includes an intermediate partition plate portion 220f. The intermediate partition plate portion 220f is disposed between the door body plate portion 13a and the inner plate portion 220c. The lower end portion of the intermediate partition plate portion 220f is continuous with the closing plate portion 220d. The upper end portion of the intermediate partition plate portion 220f is spaced downward from the upper plate portion 220e. An exhaust port 220g opens downward, further back in the housing 10 than the intermediate partition plate portion 220f.

In the third embodiment, when air flows from the intake port 21 into the lower side of the intake air passage 24 and enters the intake duct component 220, it flows upward, then flows toward the back side beyond the intermediate partition plate portion 220f, and then flows downward to be discharged from the exhaust port 220g.

The sound-absorbing board 23 is fixed to the upper surface of the frame 11, protruding upward and extending in the depth direction. The upper end of the sound-absorbing board 23 faces the exhaust port 220g. The air discharged from the intake air passage 24 into the housing 10 is guided downward by the sound-absorbing board 23, and then hits the upper surface of the frame 11 and flows toward the rear of the housing 10. This creates an air flow that flows toward the rear at the bottom inside the housing 10.

In the third embodiment, the sound absorbing plates 23 may be any number of plates equal to or greater than two. The sound absorbing plates 23 may also extend in a direction intersecting the direction of extension of the intake air passage 24 downstream, i.e., diagonally forward or diagonally backward.

Therefore, according to this embodiment 3, as in embodiment 1, the amount of air taken into the aircraft by the intake duct component 220 is sufficiently ensured, improving cooling performance while efficiently reducing external noise.

(Embodiment 4)
13 shows an air intake duct structure 20 according to a fourth embodiment of the present invention. This fourth embodiment differs from the first embodiment in that air is supplied downward inside the housing 10 and that the sound absorbing plate 23 is disposed below the air intake duct component 240. In the following, the same parts as those in the first embodiment are given the same reference numerals and their explanation is omitted, and only the different parts will be explained.

In the fourth embodiment, the intake air passage 24 extends upward, then bends and extends downward. The intake duct component 240 of the fourth embodiment has a front plate portion 240a, a rear plate portion 240b, an inner plate portion 240c, and a blocking plate portion 240d similar to those of the first embodiment, and further has an upper plate portion 240e at the top. The upper plate portion 240e is a member for blocking the upper end portion of the intake duct component 240.

Furthermore, the intake duct component 240 includes an intermediate partition plate portion 240f. The intermediate partition plate portion 240f is disposed between the front side plate portion 240a and the rear side plate portion 240b, and extends in the vertical direction. The lower end portion of the intermediate partition plate portion 240f is continuous with the blocking plate portion 240d. The upper end portion of the intermediate partition plate portion 240f is spaced downward from the upper plate portion 240e. The exhaust port 240g is disposed on the rear side of the intake port 21 and opens downward.

In the fourth embodiment, when air flows from the intake port 21 into the lower side of the intake air passage 24 and enters the intake duct component 240, it flows upward, then flows rearward beyond the intermediate partition plate portion 240f, and then flows downward to be discharged from the exhaust port 240g.

The sound absorbing board 23 is located below the exhaust port 240g and extends in the vertical direction. The air discharged from the intake air passage 24 into the housing 10 is guided downward by the sound absorbing board 23. In the fourth embodiment, the sound absorbing board 23 may be any number of two or more. The sound absorbing board 23 may also extend in a direction intersecting the extension direction of the intake air passage 24 downstream, i.e., diagonally forward or diagonally backward.

Therefore, according to this embodiment 4, as in embodiment 1, it is possible to efficiently reduce external noise while ensuring a sufficient amount of air intake into the aircraft through the intake duct component 240, improving cooling performance.

(Embodiment 5)
14 shows an air intake duct structure 20 according to a fifth embodiment of the present invention. This fifth embodiment has a similar configuration to the air intake duct component 220 of the third embodiment, but differs from the third embodiment in that a sound absorbing plate 23 is fixed to the air intake duct component 220. In the following, the same parts as those in the third embodiment are given the same reference numerals and their explanation is omitted, and only the different parts will be explained.

In the fifth embodiment, the exhaust port 220g opens downward, and the sound absorbing plate 23 is disposed below this opening. The sound absorbing plate 23 is fixed to the intake duct component 220. This allows the vertical dimension of the intake duct structure 20, including the intake duct component 220 and the sound absorbing plate 23, to be shortened.

According to this embodiment 5, as in embodiment 1, the amount of air taken into the aircraft by the intake duct component 220 is sufficiently ensured, improving cooling performance while efficiently reducing external noise.

(Embodiment 6)
15 shows an air intake duct structure 20 according to a sixth embodiment of the present invention. The sixth embodiment differs from the first embodiment in that exhaust ports 22e are provided at the front and rear, and in the position of the sound absorbing material 23. In the following, the same parts as those in the first embodiment are given the same reference numerals and their explanations are omitted, and only the different parts will be explained.

An upper plate portion 22f is provided on the upper portion of the intake duct component 22, and the upper portion of the intake duct component 22 is closed by this upper plate portion 22f. On the other hand, exhaust ports 22e are formed on the upper portions of the front side plate portion 22a and the rear side plate portion 22b. Air is exhausted forward from the exhaust port 22e formed on the front side plate portion 22a, and air is exhausted rearward from the exhaust port 22e formed on the rear side plate portion 22b.

On the other hand, the sound absorbing plate 23 is disposed in front of the exhaust hole 22e of the front side plate portion 22a and extends forward, and is disposed behind the exhaust hole 22e of the rear side plate portion 22b and extends backward. This allows air to be guided in both the forward and rearward directions within the housing 10.

According to this sixth embodiment, as in the first embodiment, the intake duct component 22 can ensure a sufficient amount of intake air into the aircraft, improving cooling performance while efficiently reducing external noise.

In the example shown in FIG. 15, the exhaust port 22b and the sound absorbing plate 23 are formed at the front and rear, but they may be formed on only one side. In that case, the exhaust port 22b on the other side will be blocked.

(Embodiment 7)
16 shows an intake duct structure 20 according to a seventh embodiment of the present invention. The seventh embodiment differs from the first embodiment in that the exhaust port 22e opens toward the back side of the housing 10 and in the position of the sound absorbing material 23. In the following, the same parts as those in the first embodiment are given the same reference numerals and their explanations are omitted, and only the different parts will be explained.

An upper plate portion 22f is provided on the upper portion of the intake duct component 22, and the upper portion of the intake duct component 22 is closed by this upper plate portion 22f. On the other hand, an exhaust port 22e is formed on the upper portion of the inner plate portion 22c. Air is exhausted from the exhaust port 22e to the rear side of the housing 10.

On the other hand, the sound absorbing plate 23 is disposed in front of the exhaust hole 22e and extends vertically and toward the rear of the housing 10. This allows air to be guided to the rear of the housing 10.

According to this embodiment 7, as in embodiment 1, the amount of air taken into the aircraft by the intake duct component 22 is sufficiently ensured, improving cooling performance while efficiently reducing external noise.

The above-described embodiments are merely illustrative in all respects and should not be interpreted as limiting. Furthermore, all modifications and variations within the scope of the claims are within the scope of the present invention.

In addition, in the above-mentioned embodiments 1 to 7, the intake port 21 is formed in the door 13, and the intake duct components 22, 220, and 240 are fixed to the door 13. However, this is not limited to the above, and although not shown, the intake port 21 may be formed in the side wall 12, and the intake duct components 22, 220, and 240 may be fixed to the side wall 12. This allows the intake air passage 24 to be formed by the intake duct components 22, 220, and 240 and the inner surface of the side wall 12. In this case, for example, by forming the intake port 21 in the side wall 12 other than the door 13, if there is free space near the side wall 12 inside the housing 10, the intake duct components 22 and 220 can be placed in the free space, making effective use of the space. In addition, since the intake air passage 24 can be formed using the inner surface of the side wall 12, it can be made even more compact.

As explained above, the present invention can be applied to engine-driven machines equipped with generators and compressors, for example.

Reference Signs List 1: Engine working machine 10: Housing 11: Frame 12: Side wall 13: Door 14: Upper cover 20: Intake duct structure 21: Intake port 22: Intake duct component 22a: Front side plate portion (first plate portion)
22b Rear side plate portion (second plate portion)
22c Inner plate portion (third plate portion)
22d Closure plate portion 23 Sound absorbing plate (first to fourth sound absorbing plates 23A to 23D)
231 Sound absorbing material 24 Intake air passage E Engine G Generator (driven machine)

Claims (7)

The engine,
A driven machine driven by the engine;
In an intake duct structure for an engine working machine including a housing that houses the engine and the driven machine,
The door of the housing is formed with an air intake port for drawing in outside air,
an intake duct component forming an intake air passage connected to the intake port, and a plurality of sound absorbing plates arranged outside the intake air passage to guide air discharged from the intake air passage into the housing in a predetermined direction ,
the intake duct component includes first and second plate portions fixed to an inner surface of the door, extending in a flow direction of the intake air passage, and arranged to face each other; a third plate portion extending from the first plate portion to the second plate portion and arranged to face the inner surface of the door; and a closing plate portion closing an upstream end of the intake air passage,
the first plate portion, the second plate portion, the third plate portion, the closing plate portion, and an inner surface of the door form the intake air passage,
The sound-absorbing panels are arranged at intervals from each other in the thickness direction, fixed to the inner surface of the door, protrude from the inner surface of the door toward inside the housing, and are arranged downstream in the air flow direction away from the air exhaust port which is the downstream end of the intake air passage . The intake duct structure for an engine work machine according to claim 1,
1 is a perspective view of an intake duct structure for an engine working machine according to the first embodiment of the present invention; The intake duct structure for an engine work machine according to claim 1,
1 is a perspective view of an intake duct structure for an engine-operated work machine according to an embodiment of the present invention; The intake duct structure for an engine work machine according to any one of claims 1 to 3 ,
1 is a schematic diagram showing an intake duct structure for an engine working machine according to the first embodiment of the present invention; The intake duct structure for an engine work machine according to any one of claims 1 to 4 ,
13. An intake duct structure for an engine-driven working machine, wherein the intake duct component forms the intake air passage so as to extend upward from the intake port. The intake duct structure for an engine work machine according to any one of claims 1 to 5 ,
An intake duct structure for an engine-driven working machine, wherein the plurality of sound-absorbing panels are substantially parallel to one another. The intake duct structure for an engine work machine according to any one of claims 1 to 6 ,
An intake duct structure for an engine work machine, characterized in that the plurality of sound-absorbing panels guide air discharged from the intake air passage into the housing toward a cooled portion within the housing.

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