JP2004285889A - Engine compartment ventilation structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an engine compartment ventilation structure provided inside a bulkhead body and capable of sufficiently ventilating an engine compartment, preventing the pressure of the engine compartment from tending to be negative, suppressing a rise in temperature inside the engine compartment, and suppressing the emission of a sound to the outside. <P>SOLUTION: This structure is provided with the bulkhead body, the engine compartment provided inside the bulkhead, an engine installed inside the engine compartment, an ejector provided on the bulkhead body and sucking air inside the engine compartment and ejecting the same to the outside, a ventilation intake provided on the bulkhead body and guiding part of air sent by a fan provided to oppose a heat exchanger at the outside of the bulkhead body to the inside of the engine compartment. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an engine room ventilation structure used for a working machine or the like.
[0002]
[Prior art]
In a typical work machine, for example, a hydraulic excavator, the engine is housed in a substantially hermetic bulkhead in order to suppress engine noise from leaking out of the fuselage. The heated air in the engine room is drawn by the flow of muffler exhaust between the exhaust pipe provided in the partition and the muffler chimney projecting inside, which is an ejector that uses the exhaust of the engine. It is sucked and released to the outside. The air introduced into the engine room to ventilate the engine room is sucked through a gap between covers forming a partition, or an intake port formed in the partition and opened to the outside. In order to suppress the emission of engine noise to the outside, the partition body is provided with a noise absorbing means such as a sound absorbing material or a louver at the partition body and at the intake port (for example, see Patent Document 1).
[0003]
[Patent Document 1]
JP-A-11-148348 (FIG. 1)
[0004]
[Problems to be solved by the invention]
However, the conventional engine room ventilation structure of the above-described embodiment has the following problems to be solved.
[0005]
(1) Inlet and emission noise:
When an intake port for sucking outside air is provided in the engine room, the opening area of the intake port must be as small as possible in order to suppress noise emitted from the intake port. However, if the opening area is reduced, the amount of intake air decreases and sufficient ventilation becomes difficult.
[0006]
(2) Oil leakage outside the engine compartment:
When the air in the engine room is sucked out by the ejector and the intake air into the engine room is small, the engine room tends to be under negative pressure. If an oil leak occurs in a pump room provided with a hydraulic pump, which is a hydraulic pressure source provided outside the partition, air containing oil flows into the engine room from a slight gap in the partition, and a muffler, etc. May come in contact with the high-temperature part and ignite. For this reason, sufficient measures must be taken for the partition wall connected to the pump chamber as a fire wall.
[0007]
(3) Effects on equipment in the engine compartment:
If the ventilation in the engine room is not sufficient, the temperature in the engine room will increase, which may adversely affect the durability of devices such as electrical components arranged in the room. In order to improve the weather resistance of the device, the cost of the device becomes high.
[0008]
(4) Measures against heat shielding around the engine room:
If the ventilation of the engine room is insufficient and the temperature inside the engine room rises significantly, it is necessary to take measures against heat so as to prevent the temperature of members such as a cover around the engine room touched by an operator or the like from rising.
[0009]
The present invention has been made in view of the above facts, and a technical problem thereof is that the engine room provided inside the partition body can be sufficiently ventilated, and the engine room is prevented from becoming negatively pressurized. It is an object of the present invention to provide an engine room ventilation structure capable of suppressing an increase in temperature in an engine room and suppressing noise emission to the outside.
[0010]
[Means for Solving the Problems]
According to the first aspect of the present invention, there is provided a partition body formed substantially in a closed state, an engine room provided inside the partition body, an engine disposed in the engine room, and one of the partition bodies. Ejector that sucks air inside the engine room using the exhaust gas of the engine and discharges it to the outside, and part of the air blown by the fan that is installed outside the partition and facing the heat exchanger into the engine room An engine room ventilation structure, comprising: a ventilation inlet provided in a partition wall for guiding.
[0011]
In addition to the ejector that sucks out the air in the engine room, an air intake that forcibly introduces the air from the fan into the engine room is provided to ensure sufficient ventilation, and the engine room is prevented from becoming negatively pressured. The temperature rise in the room is suppressed, and the radiation of noise to the outside is suppressed by the radiator and the rotating fan.
[0012]
According to a second aspect of the present invention, in the engine room ventilation structure according to the first aspect, the fan is driven by a hydraulic motor, and the partition body prevents the air passing through the hydraulic motor from entering the air intake. It has a partition wall.
[0013]
Then, oil leaked due to damage to the hydraulic motor or the like is prevented from entering the engine room.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an engine room ventilation structure configured according to the present invention will be described in more detail with reference to the accompanying drawings and FIG. 1 showing a preferred embodiment.
[0015]
The engine room ventilation structure includes a partition wall 2 formed substantially in a closed shape, an engine room 4 provided inside the partition body 2, an engine 6 disposed in the engine room 4, An ejector 8 is provided in a part of the engine 6 for sucking air in the engine room 4 using the exhaust gas of the engine 6 and discharging the air to the outside, and a fan 12 provided opposite the heat exchanger 10 outside the partition 2. An air inlet 14 provided in the partition wall 2 for guiding a part of the airflow to the engine room 4 is provided.
[0016]
The partition 2 is formed in a hollow substantially rectangular parallelepiped shape with six surfaces covered by a cover plate. A muffler 18 as a silencer is provided in an exhaust pipe 16 in an engine exhaust system in the engine room 4, and a tail pipe provided in an exhaust outlet pipe 18 a of the muffler 18 and a part of an upper surface cover plate 2 a of the partition body 2. The ejector 8 is formed by 20.
[0017]
The ejector 8 includes an exhaust outlet pipe 19 as an inner pipe, a tail pipe 20 as an outer pipe protruding from the upper surface cover plate 2a longer than the exhaust outlet pipe 19 around the exhaust outlet pipe 19, an exhaust outlet pipe 19, and a tail. A suction gap 22 is formed between the pipe 20 and the pipe 20, and the air in the engine room 4 is sucked and discharged through the suction gap 22 by the flow of exhaust gas from the exhaust outlet pipe *.
[0018]
A heat exchanger 10 and a fan 12 are provided outside the partition body 2 on the front cover plate 2b side (the left side in FIG. 1). A pump chamber 25 in which a hydraulic pump 24 driven by the engine 6 is disposed is formed on the rear cover plate 2c side (the right side in FIG. 1) of the partition 2. As the heat exchanger 10, for example, a radiator for engine cooling water, an oil cooler for cooling hydraulic oil of a hydraulic device, and the like are provided. The fan 12 is driven by a hydraulic motor 26 rotated by hydraulic oil supplied from a hydraulic pump 24.
[0019]
By rotating the fan 12 by the hydraulic motor 26, the outside air indicated by the arrow W1 first passes through the heat exchanger 10, passes through the fan 12, and flows along the front cover plate 2b of the partition wall 2, and as indicated by the arrow W2. Then, the air flows upward and is discharged from the discharge port 28, and a part of the water flows to the air inlet 14 as indicated by an arrow W3.
[0020]
The air inlet 14 is formed at a lower portion of the front cover plate 2b of the partition wall 2 opposite to the outlet 28 with the hydraulic motor 26 interposed therebetween. Between the ventilation inlet 14 and the hydraulic motor 26, a partition wall 30 for preventing the air passing through the hydraulic motor 26 from flowing into the ventilation intake 14 covers a lower portion of the hydraulic motor 26 and extends from the front cover plate 2 b to the shelf. It is provided overhanging.
[0021]
The operation of the engine room ventilation structure as described above will be described.
[0022]
(1) Improvement of ventilation performance of engine room:
A part of the air blown by the fan 12 indicated by the arrow W3 is forcibly flowed into the engine room 4 through the air intake 14 provided in the front cover plate 2b of the partition 2. The air in the engine room 4 is drawn by the ejector 8 and flows to the ejector 8 as shown by an arrow W4, and is sucked and discharged through the suction gap 22 of the ejector 8 as shown by an arrow W5. Therefore, sufficient ventilation of the engine room 4 can be performed, and ventilation performance can be improved.
[0023]
(2) Prevention of negative pressure in engine room:
By forcibly flowing the air from the fan 12 into the engine room 4, the engine room 4 is prevented from becoming slightly negative. Therefore, the flow of oil-containing air into the engine room 4 from the pump room 25 or the like is prevented. Further, by forcibly flowing the air from the fan 12, the effect of the ejector 8 can be enhanced, and the ventilation performance can be improved.
[0024]
(3) Prevention of engine room temperature rise:
Since the ventilation performance is improved by forcibly flowing the blast of the fan 12 into the engine room 4, a rise in the temperature of the engine room 4 is prevented. Therefore, it is possible to eliminate a problem that adversely affects the durability of a device such as an electrical component, thereby improving reliability. In addition, no special heat shielding measures are required for members such as the cover around the engine room 4.
[0025]
(4) Noise reduction:
Further, since the air inlet 14 is provided on the front cover plate 2 b of the partition 2 on the side of the heat exchanger 10 and the fan 12, the noise of the engine room 4 flowing out from the air inlet 14 to the outside is eliminated by the fan 12. In addition, the noise is cut off and attenuated by the heat exchanger 10, and the noise emitted from the engine room 4 is reduced.
[0026]
(6) Fire prevention measures for fan-driven hydraulic motors:
In addition, since the partition wall 30 is provided so that the air blown through the portion of the hydraulic motor 26 that drives the fan 12 does not flow into the air intake 14, even if the hydraulic motor 26 leaks oil, the oil leaks. There is no danger of oil entering the engine room 4 from the air intake 14 and igniting.
[0027]
【The invention's effect】
According to the engine room ventilation structure configured according to the present invention, it is possible to sufficiently ventilate the engine room provided inside the partition body, to prevent the engine room from becoming slightly negative, and An engine room ventilation structure capable of suppressing a rise in temperature and suppressing emission of noise to the outside is provided.
[Brief description of the drawings]
FIG.
1 is a schematic diagram illustrating an embodiment of an engine room ventilation structure configured according to the present invention.
[Explanation of symbols]
2: Partition wall 4: Engine room 6: Engine 8: Ejector 10: Heat exchanger 12: Fan 14: Ventilation inlet 26: Hydraulic motor 30: Partition wall

Claims (2)

A partition body formed substantially in a sealed state, an engine room provided inside the partition body, an engine disposed in the engine room, and exhaust gas of the engine provided in a part of the partition body An ejector that sucks air in the engine room and discharges it to the outside, and a blast intake port provided in the partition body that guides a part of the air blown by a fan provided outside the partition wall and facing the heat exchanger into the engine room. An engine room ventilation structure, comprising: 2. The engine room ventilation structure according to claim 1, wherein the fan is driven by a hydraulic motor, and the partition wall has a partition wall for preventing air passing through the hydraulic motor from entering the air intake.

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