JP3173538B2 - Engine room soundproofing / cooling system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a soundproofing / cooling device for an engine room of an engine type industrial vehicle such as a forklift or a shovel loader.

[0002]

2. Description of the Related Art In a conventional industrial vehicle having a structure opened to the lower side of an engine room, noise (mainly engine sound) emitted from the engine room is large, and problems such as contamination of equipment in the engine room are caused. In order to solve this problem, a low-noise type in which the undersurface of the engine room is covered by an undercover C shown in FIGS. 5 and 6 is provided. FIG. 7 is a side view showing the entire forklift of the standard specification. Regarding the structure of the undercover of an industrial vehicle that covers the lower surface of the engine room,
Japanese Unexamined Patent Publications Nos. 2-125648 and 2-88826 are provided. In other words,
In Japanese Patent No. 2-125648, an air introduction portion is formed by bending a front edge of an under cover attached to a lower end portion of a side frame obliquely downward. The under cover is provided with a plurality of air introduction portions shown in FIG. In Japanese Utility Model Application Laid-Open No. 2-88826, air into the engine room is supplied from an inlet formed in an under cover, and a guide member is provided for flowing the air flowing out of the inlet toward the wall surface of the hydraulic oil tank. As a result, the contact of the cooling air with the wall surface of the hydraulic oil tank is positively activated, and the heat radiation effect of the hydraulic oil is positively performed. Further, a plurality of air introduction portions shown in FIG. In FIGS. 3, 4, 5, 6, and 7, e is an engine, d is a sound absorbing material, c is an undercover, s is a side frame, r is a radiator, w is a counterweight, f is a fan, and p is exhaust. Indicates a hole.

[0003]

However, in the case of the above-mentioned closed structure with the under cover, the structure shown in FIG. 6 is adopted, and the insufficient air intake causes the engine to overheat due to insufficient engine cooling. In order to enhance the cooling effect, the air introduction part and the guide member shown in FIGS. 3 and 4 are provided, but the noise radiated from there is reflected on the road surface to increase the operation ear noise and the surrounding noise. There was a problem of doing it. That is, in Japanese Utility Model Laid-Open No. 62-125648, the sound emitted from the engine wall, which is a noise source, from a plurality of air inlets directly propagates to the outside, and is reflected on the road surface to increase the operational ear noise and the ambient noise. In the same way, in Japanese Utility Model Laid-open No. 2-88826,
Although the hydraulic oil tank is cooled, the sound radiated from the engine wall, which is the noise source, from the air intake formed in the under cover directly propagates to the outside, and is reflected on the road surface, increasing the operational ear noise and ambient noise. Had been done.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has a plurality of air spaces at appropriate intervals in front, rear, left and right of an undercover which covers a lower surface of an engine room.
The introduction portion is provided, wraps and slit air introducing portion which is longer open in the vehicle width direction, and the lower guide piece projecting inclined obliquely forward on the lower side of the slit, the front and rear and the lower guide piece It is formed by an upper guide piece projecting obliquely rearward with an interval above the slit ,
Inclination of the lower and upper guide pieces
Provide a horizontal part at the tip of the part parallel to the undercover
At the same time, the undercover has a sound absorbing material attached to both the upper surface thereof and both surfaces of the slit of the air introducing portion.

[0005]

According to the present invention, since the under cover having the above-described structure is employed, outside air can be positively introduced into the engine room by several air introducing portions. The sound absorbing material reduces the direct sound, absorbs the reflected sound, prevents the direct sound and the reflected sound from propagating to the outside, and reduces the leakage of noise as much as possible. Is big. Therefore, this invention
It is possible to improve the soundproofing effect without impairing the cooling performance
it can.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a structural view showing an embodiment of an undercover 7 according to the present invention, and FIG. 2 is a diagram showing an embodiment of FIG. 1 in which sound waves emitted from a wall of an engine 4 propagate from an air inlet 11 of the undercover 7 to the outside. It is a schematic diagram which shows the process which performs. As shown in FIG. 1, the under cover 7 is provided with two air introduction portions 11, and the slits 12, which are long and open in the vehicle width direction at appropriate intervals, are inclined obliquely forward below the slits 12. A lower guide piece 13 projecting from
An air introduction portion 11 is formed on the upper side of the slit 12 so as to be wrapped back and forth with the lower guide piece 13 and an upper guide piece 14 having a certain interval and inclined obliquely rearward. . Therefore, when the vehicle is running, as shown by the arrows, the gap formed by the upper and lower guide pieces 14 and 13 of the slit 12 of the air introduction portion 11 of the undercover 7 is guided to the upper surface of the undercover 7 by the outside air being guided. I will That is, air during traveling is actively taken into the engine room, and the air is guided from below the engine 4 to the wall of the engine 4, passes through the radiator 6, and is exhausted to the rear of the vehicle body from the exhaust holes 3 a.

Further, of the acoustic power Wo radiated from the sound source (engine sound, transmission sound, etc.), a part becomes the transmitted sound power Wt, and a part becomes the under cover 7.
W absorbed by the sound absorbing material 16 and the like adhered to the upper surface of
a, the power Wd of the direct sound not entering the sound absorbing material 16 at all and the power Wr of the reflected sound leaking from the slit 12 of the air introduction portion 11 reflected from the under cover 7 and leaked from the under cover 7.
And propagate to the outside. The following equation shows this relationship. Wo = Wt + Wa + Wd + Wr i.e. upper and lower in the structure of the invention shown in FIG. 2
The sound absorbing material 16 adhered to both sides of the slit 12, which is a passage, of the air introducing portion 11 composed of the guide pieces 14 and 13 reduces direct sound and absorbs reflected sound. , And noise leakage can be reduced as much as possible, so that the effect of reducing ambient noise is remarkable.

[0008]

According to the present invention , the lower guide piece of the slit portion,
Wrap the upper guide piece back and forth
By adjusting the slit width, the outside air passing through the slit
The wind speed can be set freely, and the engine is located through the front slit.
Outside air taken into the room is taken in from the rear slit
Has a suction effect on the outside air,
The amount of outside air introduced into the inside increases, and the rear slit
The same suction effect works and the negative pressure in front of the fan is accelerated.
The outside air introduced from the slit is naturally cooled by the cooling fan
To the radiator behind the fan.
Efficiency can be improved. Also under the slit
A tip portion of the lower guide piece projecting inclined obliquely forward
And the lower guide piece.
Wrap forward and backward and tilt diagonally backward with an interval above
The tip of the upper guide piece that projects obliquely is attached to the lower guide piece.
By installing it in parallel with the under cover as in
Outside air taken into the engine room directly reaches the bottom of the engine
And introduced without disturbing the wind flow in the engine room
Outside air passes between the undercover and the bottom of the engine
To reach the cooling fan and sufficiently remove the hot air in the engine room.
Can scavenge and increase the cooling efficiency in the radiator
You. Furthermore, the turbulence of the outside air flow immediately after passing through the slit (wind
Vortex) can be prevented, and by adjusting the slit width
Increasing the outside air flow rate by increasing the outside air passing wind speed for cooling
Efficiency is increased. Therefore, according to the present invention, when the vehicle is running, outside air is actively taken into the engine room above the undercover from the air introduction portion, and the hot air in the engine room is sufficiently scavenged. The sound absorbing materials adhered to both surfaces of the introduction passage absorb the direct sound of the engine sound and the transmission sound, prevent the direct sound from propagating to the outside, and reduce noise leakage as much as possible.

[Brief description of the drawings]

FIG. 1 is a structural view showing an embodiment of an undercover according to the present invention.

FIG. 2 is a schematic view showing a process in which a sound wave radiated from an engine wall in FIG. 1 propagates from an air introduction portion of an undercover to the outside.

FIG. 3 is a schematic diagram showing a process in which a sound wave radiated from an engine wall surface in a conventional undercover propagates from an air introduction portion of the undercover.

FIG. 4 is a schematic diagram showing a process in which a sound wave radiated from an engine wall in a conventional undercover propagates from an air introduction portion of the undercover to the outside.

FIG. 5 is an explanatory view for attaching an under cover.

FIG. 6 is a structural explanatory view of a conventional under cover.

FIG. 7 is a side view showing the entire forklift.

[Explanation of symbols]

Reference Signs List 4 engine 7 under cover 11 air introduction part 12 slit 13 lower guide piece 14 upper guide piece 16 sound absorbing material

Claims (1)

(57) [Claims] A plurality of air guides are provided at appropriate intervals in front, rear, left and right of an under cover (7) covering a lower surface of an engine room.
The air inlet (11) is provided with a slit (12) opened long in the vehicle width direction, and a lower guide piece projecting obliquely forward and obliquely below the slit (12). forming (13), the upper guide pieces (14) projecting inclined obliquely rearward at an interval on the upper side of the slit (12) is wrapped back and forth with the lower gas <br/> id piece (13) The lower guide piece (13)
And the tip of each inclined part of the upper guide piece (14)
While providing a horizontal part parallel to the under cover (7),
The under cover (7) has an upper surface and an air introduction portion (11).
The sound absorbing material (16) is attached to both sides of the slit (12),
Soundproofing and cooling equipment for engine rooms in industrial vehicles.