JPH0627809Y2 - Engine soundproofing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Field of the Invention The present invention relates to a soundproof device for an engine, such as an engine generator, which is entirely covered with a soundproof case.

2. Description of the Related Art FIGS. 6 and 7 show a conventional structure in which the entire engine including a generator is covered with a soundproof case. In the figure, (1) is an engine, and (2) is a generator driven by this engine (1), which is attached to the side surface of the engine (1). (3) is a box-shaped soundproof case that covers the entire engine (1) and generator (2). The engine (1) and the generator (2) are, as shown in FIG. 7, a pair of frame frames (4) having a groove-shaped cross section.
The frame (4) and the crosspiece (5) passed between the frame frames (4) and (4) are mounted on a frame (6) via a vibration-proof material or the like. ), A floor plate (7) is attached to the lower surface of the crosspiece (5) to cover the lower part of the engine (1) and the generator (2). Then, the floor plate (7) entered from the oil spilled when replenishing the lubricating oil to the engine (1) or when deaerating the fuel, and the exhaust port (8) on the upper surface of the case (3). A fairly large permeation hole (9) (9) for discharging rainwater etc.
Are provided in plural.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention As described above, conventionally, the floor plate (7) is provided with holes (9) (9) for discharging oil and rainwater. However, since noise is also discharged to the outside, not only a sufficient noise reduction effect cannot be obtained, but conversely, due to the negative pressure in the case (3), dust and sand below the floor plate (7) Wipe up and collect the dust and sand on the floorboard (7)
There was a risk of depositing on the engine (1), damaging the generator, etc., leading to destruction. From the viewpoint of reducing noise, it is conceivable to apply a process such as attaching a sound absorbing material to the floor plate (7), but in this kind of engine generator, etc., due to the problem of durability. It was difficult to perform sound absorption processing on the floor plate (7).

In this invention, in such a soundproof type engine, even if the floor plate is provided with the above-mentioned oil and water permeation holes, noise does not directly leak to the outside and dust from the outside. -The purpose of the present invention is to provide an engine soundproofing device that prevents direct inhalation of sand.

Means for Solving the Problems In order to achieve the above object, in the present invention, in an engine soundproof structure in which the entire engine is covered with a soundproof case, the floor plate covering the lower part of the engine is made into a double structure so that the floor plates are A space is provided in each of the floor plates, and a plurality of permeation holes for discharging leaked lubricating oil and fuel or invading rainwater are formed in the horizontal portions of the floor plates by shifting their horizontal positions from each other, and these permeation holes are formed. It is characterized by giving resistance to the air passing through the holes.

Action The space between the floorboards that are doubled provides resistance to the air that passes through the perforation holes of the floorboards, reducing the amount of noise leaked to the outside and preventing dust and sand from the outside. The suction volume is also reduced.

EXAMPLES Next, examples of the present invention will be described. In FIGS. 1 to 4 showing the embodiment, the same reference numerals are used for the same parts as the conventional one. In these embodiments, as in the conventional case, the horizontal portions of the floor plate (7) attached to the lower surface of the crosspiece (5) of the frame (6) have permeation holes (9) (9) for discharging rainwater and oil. ... is provided, but further, another floor plate (10) is provided below the floor plate (7) to form a space (12) between the floor plate (7) and (10), Formed in the horizontal portion of the lower floor plate (10) are transmission holes (11) (11) ... at positions horizontally shifted so as not to coincide with the transmission holes (9) of the upper floor plate (7). ing.

Therefore, as shown in FIG. 4, even when the inside of the soundproof case (3) has a negative pressure, the air from the outside still has a perforation hole (11) in the lower floor plate (10) as indicated by a solid arrow. Although it passes through and enters the space (12), ventilation resistance is given between this space (12) and the permeation hole (9) of the upper floor plate (7). Therefore, conversely, the noise leaking from the inside of the soundproof case (3) to the outside is also reduced. In addition, the amount of dust, sand, and the like on the lower side, which is sucked into the case (3), is greatly reduced by such resistance. The floor plates (7) and (10) use damping steel plates with a thickness of about 1.6 mm in order to reduce the radiated sound generated by themselves.

FIG. 5 shows the relationship between the size of the gap forming the space (12) between the floor plates (7) and (10) and the noise from the floor plates (7) and (10). As shown in
The noise amount becomes larger as the transmission loss (air flow resistance) becomes smaller, but it can be seen that the noise amount leaking to the outside is very small when the gap is about 20 mm. On the other hand, if it is made too small, the effect of draining oil and water from the permeation holes (9) (11) will be lost, so that the applicable range of the gap will eventually be
About 5 to 20 mm is suitable. The size of the transmission holes (9) (11) is an equivalent hole of about 10 mm to 12 mm, and the size of the aperture ratio in the figure depends on the area of the transmission holes (9) (11) relative to the area of the floor plates (7) (10). Indicates the size of the ratio. In addition, by making the floor plates (7) and (10) have a double structure in this way,
Noise from the floor plates (7) and (10) is reduced by about 16 dB (A) as compared with the conventional structure. Also, the total noise level has been reduced from 71.3 dB (A) to 70 dB (A). Noise is measured 1 m from the outer wall of the soundproof case (3)
And at a height of 1.2 m, the average measured from 5 directions was taken.

In FIGS. 1 and 2 showing the cross section of the soundproof case (3), (13) is a fuel tank arranged above the engine (1), and (14) is a side of the fuel tank (13). An air cleaner (15) is disposed on one side, a radiator (15) is also disposed on the side of the air cleaner (14), and an exhaust silencer (16) is disposed on the other side. Also,
The arrows in the figure show the flow of intake air and cooling air taken in from the two sides of the soundproof case (3). (17) shows an inlet for cooling air, (18) in FIG. 3 shows an inlet for intake air, and an air outlet (19) is opened on the upper side of the soundproof case (3).

Effects of the Invention As described above, according to the present invention, by forming the floor plates in a double structure, a space is formed between the floor plates, and resistance is given to the air passing through the permeation holes formed in the floor plates. As a result, the amount of noise emitted from the inside of the case to the outside can be reduced, and the amount of dust, sand, etc. sucked in from the outside can also be reduced. Rainwater that has entered can be discharged from these permeation holes as usual. Further, in order to reduce the amount of noise without taking such a measure, the soundproof case itself has to be upsized, but this invention has an effect that it can be realized without such upsizing.

[Brief description of drawings]

FIG. 1 is a front view of an engine generator shown by cutting a soundproof case in a vertical direction, FIG. 2 is a side view of an engine generator shown in a direction perpendicular to FIG. 1, and FIG. Fig. 4 is a perspective view showing a part of the soundproof case of Fig. 4 in a partially cutaway view. FIG. 6 is a front view of a conventional engine generator showing a soundproof case in a longitudinal section, and FIG. 7 is a partially cutaway perspective view of the conventional soundproof case. (1) …… engine, (3) …… soundproof case, (7) (10) …… floor plate, (9) (11) …… transmission hole, (12) …… space.

Claims (1)

[Scope of utility model registration request] 1. An engine soundproof structure in which the entire engine is covered with a soundproof case, and a floor plate covering the lower part of the engine has a double structure to provide a space between the floor plates.
In the horizontal part of these floor plates, a plurality of permeation holes for discharging leaked lubricating oil and fuel or invading rainwater are formed by shifting their positions in the horizontal direction from each other to resist the air passing through these permeation holes. Engine soundproofing device characterized by being given.