JP4223847B2 - Engine room ventilation structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an engine room ventilation structure used for a work machine or the like.
[0002]
[Prior art]
In a typical work machine, such as a hydraulic excavator, the engine is housed in a substantially sealed bulkhead to prevent engine noise from leaking out of the fuselage. The heated air in the engine room is drawn by the flow of the exhaust of the muffler between the exhaust pipe provided in the partition body, which is an ejector that uses the exhaust of the engine, and the muffler chimney that protrudes into the exhaust pipe. It is sucked and released to the outside. Air introduced into the engine compartment to ventilate the engine compartment is sucked through a gap between the covers forming the partition wall or an intake port formed in the partition wall and opened to the outside. In order to suppress the release of engine noise to the outside, the partition body is provided with noise prevention 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]
Japanese Patent Laid-Open No. 11-148348 (FIG. 1)
[0004]
[Problems to be solved by the invention]
However, the conventional engine room ventilation structure of the form as described above has the following problems to be solved.
[0005]
(1) Inlet and emission noise:
In the case where an intake port for sucking outside air is provided in the engine compartment, the opening area of the intake port must be made as small as possible in order to suppress noise emitted from the intake port. However, if the opening area is reduced, intake becomes less 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, if the intake air to the engine room is small, the engine room becomes a negative pressure. When oil leaks occur in a pump chamber provided with a hydraulic pump that is a hydraulic source provided outside the partition wall, air containing oil flows into the engine chamber from a slight gap in the partition wall, such as a muffler. There is a risk of ignition by contact with high temperature parts. Therefore, a sufficient measure as a fire barrier is required for the partition wall portion connected to the pump chamber.
[0007]
(3) Impact on equipment in the engine compartment:
If the engine room is not well ventilated, the temperature inside the engine room becomes high, and there is a risk of adversely affecting the durability of equipment such as electrical components arranged in the room. The cost of the equipment becomes high in order to improve the weather resistance of the equipment.
[0008]
(4) Heat shield measures around the engine compartment:
If the engine compartment is not well ventilated and the temperature inside the engine compartment rises significantly, heat shielding measures are required to prevent the temperature of members such as a cover around the engine compartment that an operator or the like touches from rising.
[0009]
The present invention has been made in view of the above-mentioned facts, and its technical problem is that the engine compartment provided inside the partition wall can be sufficiently ventilated, and the engine compartment is prevented from having a negative pressure. It is possible to provide an engine room ventilation structure capable of suppressing an increase in temperature in the 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 in a substantially hermetically sealed manner, an engine room provided inside the partition body, an engine disposed in the engine room, and one of the partition bodies. A part of the air blown from the ejector that sucks the air inside the engine room using the exhaust of the engine and releases it to the outside, and the fan that is provided outside the partition wall and faces the heat exchanger. A fan intake port provided in the leading partition body, the fan is driven by a hydraulic motor, and the partition body includes a partition wall for preventing the air passing through the hydraulic motor from entering the air intake port . The engine room ventilation structure is characterized by that.
[0011]
In addition to the ejector that sucks out the air in the engine compartment, a ventilation inlet that forcibly introduces the fan air into the engine compartment is provided to ensure sufficient ventilation, preventing the engine compartment from becoming a negative pressure, The rise in indoor temperature is suppressed, and the release of noise to the outside is suppressed by a radiator and a rotating fan.
[0013]
Furthermore , oil leaked due to damage to the hydraulic motor is prevented from entering the engine compartment.
[0014]
DETAILED DESCRIPTION OF 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 illustrating a preferred embodiment.
[0015]
The engine room ventilation structure includes a partition body 2 that is substantially sealed, an engine room 4 provided inside the partition body 2, an engine 6 disposed in the engine room 4, and the partition body 2. An ejector 8 that is provided in part and sucks air in the engine chamber 4 using the exhaust of the engine 6 and discharges it outside, and a fan 12 that is provided outside the partition body 2 and faces the heat exchanger 10. A blower inlet 14 provided in the partition wall 2 is provided to guide part of the blown air to the engine chamber 4.
[0016]
The partition wall 2 is formed in a hollow substantially rectangular parallelepiped shape with six surfaces covered with a cover plate. The engine exhaust system in the engine chamber 4 is provided with a muffler 18 as a silencer in the exhaust pipe 16, and a tail pipe provided in a part of the exhaust outlet pipe 18 a of the muffler 18 and the upper surface cover plate 2 a of the partition wall 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 around the exhaust outlet pipe 19 and longer than the exhaust outlet pipe 19, and an exhaust outlet pipe 19 and a tail. A suction gap 22 is formed between the pipe 20 and the air in the engine chamber 4 is sucked and discharged through the suction gap 22 by the flow of exhaust from the exhaust outlet pipe 19 .
[0018]
A heat exchanger 10 and a fan 12 are provided outside the partition body 2 on the front cover plate 2b side (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 2 c side (right side in FIG. 1) of the partition body 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 disposed. The fan 12 is driven by a hydraulic motor 26 that is rotated by hydraulic oil supplied from a hydraulic pump 24.
[0019]
When the fan 12 is rotated 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 is indicated by the arrow W2. The air flows upward and is discharged from the discharge port 28, and a part of the flow flows to the blower intake port 14 as shown by an arrow W3.
[0020]
The air inlet 14 is formed in the lower portion of the front cover plate 2b of the partition wall 2 that is located on the opposite side of the discharge port 28 with the hydraulic motor 26 interposed therebetween. A partition wall 30 that prevents the air that has passed through the hydraulic motor 26 from flowing into the air intake port 14 covers the lower portion of the hydraulic motor 26 between the air intake port 14 and the hydraulic motor 26 from the front cover plate 2b. It is provided in a projecting manner.
[0021]
The operation of the engine room ventilation structure as described above will be described.
[0022]
(1) Improvement of engine room ventilation performance:
A part of the air blown by the fan 12 indicated by the arrow W3 is forcibly introduced into the engine chamber 4 through the air intake port 14 provided in the front cover plate 2b of the partition body 2. The air in the engine chamber 4 is drawn by the ejector 8 and flows to the ejector 8 as indicated by an arrow W4, and is sucked and released through the suction gap 22 of the ejector 8 as indicated by an arrow W5. Therefore, the engine room 4 can be sufficiently ventilated and the ventilation performance can be improved.
[0023]
(2) Prevention of negative pressure in the engine compartment:
By forcing the air of the fan 12 to flow into the engine chamber 4, the engine chamber 4 is prevented from having a negative pressure. Therefore, the flow of air containing oil from the pump chamber 25 or the like to the engine chamber 4 is prevented. Furthermore, by forcing the fan 12 to flow in, 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 air blown from the fan 12 into the engine room 4, the temperature of the engine room 4 is prevented from rising. Therefore, problems that adversely affect the durability of equipment such as electrical components can be eliminated, and reliability can be improved. In addition, no special heat shielding measures are required for members such as a cover around the engine compartment 4.
[0025]
(4) Noise reduction:
Further, since the air intake 14 is provided in the front cover plate 2b of the partition wall 2 on the side of the heat exchanger 10 and the fan 12, the noise of the engine chamber 4 flowing out from the air intake 14 is drowned out by the fan 12. In addition, the noise is cut off and attenuated by the heat exchanger 10, so that the noise emitted from the engine compartment 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 passing through the portion of the hydraulic motor 26 that drives the fan 12 does not flow into the air intake port 14, even if there is an oil leak in the hydraulic motor 26, the air leaked. There is no risk of oil entering the engine compartment 4 from the air intake 14 and igniting.
[0027]
【The invention's effect】
According to the engine room ventilation structure configured in accordance with the present invention, the engine room provided inside the partition wall can be sufficiently ventilated, and the engine room can be prevented from becoming negative pressure. Provided is an engine room ventilation structure capable of suppressing an increase in temperature and suppressing noise emission to the outside.
[Brief description of the drawings]
FIG. 1 is a schematic diagram illustrating one embodiment of an engine room ventilation structure constructed in accordance with the present invention.
[Explanation of symbols]
2: Partition body 4: Engine chamber 6: Engine 8: Ejector 10: Heat exchanger 12: Fan 14: Air intake 26: Hydraulic motor 30: Partition wall

Claims (1)

A partition body formed in a substantially sealed shape, an engine chamber provided in the partition body, an engine disposed in the engine chamber, and an engine exhaust provided in a part of the partition body An ejector that sucks air inside the engine chamber and discharges it to the outside, and an air intake port provided in the partition wall that guides part of the air blown from the fan outside the partition wall to the heat exchanger It equipped with a door,
The engine room ventilation structure according to claim 1, wherein the fan is driven by a hydraulic motor, and the partition body includes a partition wall for preventing air that has passed through the hydraulic motor from entering the air intake.

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