JP2003328769A - Engine device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an engine device which solves problems caused due to insufficient ventilation by securing sufficient ventilation in an engine room of low noise structure and wherein the engine room is not affected by oil leakage in a pump room. <P>SOLUTION: The pump room 25 containing a hydraulic pump 24 driven by an engine 21 through a bulkhead body 23a is arranged on one side of the engine room 22 in which the engine 21 is contained. In the engine room 22, a compressor 41 driven by the engine 21 is installed. The compressor 41 compresses the outside air of a low temperature sucked through a suction pipe 42 and supplies it into the engine room 22 from a nozzle 45. The nozzle 45 blows compressed air of a low temperature to an engine controller 32 which must be cooled most in the engine room 22. An air exhaust means 33 is arranged in the air exhaust section of the engine room 22 to exhaust the air in the engine room 22 outside by an ejector function forcibly. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine device having a structure for separating an engine room and a pump room.

[0002]

2. Description of the Related Art As shown in FIG. 2, a construction machine (hydraulic excavator) has a cab 3 and a working device 4 mounted at a front portion of an upper revolving structure 2 provided on a lower traveling structure 1, and a rear portion thereof. In addition to the counterweight 5, an engine device 6 is mounted.

FIG. 3 shows a cross section taken along the line III-III of FIG. 2, and in the arrangement structure of the engine compartment 11 and its periphery,
For the engine 12 housed in the engine compartment 11, a hydraulic pump 13 serving as a power source of a hydraulic circuit that drives a hydraulic actuator of the work device 4, cooling water for cooling the engine, hydraulic oil for the hydraulic circuit, and the like are cooled. A cooling device (ie radiator and oil cooler) for
In addition, in recent years, as the noise of machines has been reduced, as one of the considerations, a partition wall body 15 called an enclosure is provided around the engine room 11, and the engine 12 which is a noise generation source is surrounded by this partition wall body 15. Thus, the structure is such that the noise generated from the engine 12 is confined and the noise of the machine is reduced.

When this structure is adopted, the noise of the engine 12 can be shut out, and the pump chamber 16 accommodating the hydraulic pump 13 and the engine chamber 11 can be separated from each other. Even if an oil leak occurs in
It is possible to avoid the situation where the oil is applied to a high temperature part such as the muffler 17 housed in the engine room 11.

On the other hand, on the other hand, since the heating element called the engine 12 is housed in the enclosure, the temperature inside the engine compartment 11 is significantly increased.

For this reason, it is required to improve the weather resistance of the parts attached to the engine 12, which is costly, and the engine room peripheral cover 18 which can be opened and closed on the pump room 16 together with the engine room upper cover 20 becomes hot. Inconvenience arises when a worker opens a part of the engine room peripheral cover 18 to work.

In order to avoid this, ventilation of the engine room 11 is essential. Therefore, as shown in FIG. 3, an ejector 19 utilizing the momentum of the exhaust gas flow exhausted from the muffler 17 is mounted. There is.

In this ejector 19, a muffler chimney portion 19a drawn out from the muffler 17 and an exhaust pipe 19b protruding above the engine compartment upper cover 20 are concentrically fitted through a gap 19c. Is a ventilation system that sucks and ventilates the air in the engine room 11 by using the negative pressure generated around the muffler exhaust gas flow ejected from the muffler chimney portion 19a into the exhaust pipe 19b. It is necessary to design in consideration of various engine room ventilation.

[0009]

As described above, in order to prevent the engine noise from leaking to the outside, the engine room
If the ventilation of 11 is not performed sufficiently, the heating element of the engine 12 is housed in the enclosure, so the temperature inside the engine compartment 11 rises significantly, and the durability of the components arranged in the engine compartment 11 is increased. That may affect your sex,
Alternatively, the engine room upper cover 20 and the engine room peripheral cover 18 become hot and the engine room peripheral cover 18
This causes inconvenience when a worker opens a part of the work.

The air in the engine compartment 11 is forcibly discharged to the outside by the ventilation effect of the ejector 19,
In order to prevent engine noise from leaking to the outside, the total opening area on the side where air is blown into the engine room 11 is narrowed, and the engine room 11 is introduced into the engine room 11 through a slight gap between the engine room covers and partition walls. Since only the air in the pump room is blown in, the inside of the engine room 11 becomes full of negative pressure.

Due to this phenomenon, when an oil leak occurs in the pump chamber 16 due to some reason, oil is leaked from the slight gap of the partition wall 15 between the engine chamber 11 and the pump chamber 16 toward the engine chamber 11. The contained air may flow and the oil may come into contact with the high temperature part such as the muffler 17.

The present invention has been made in view of the above circumstances, and secures sufficient ventilation in an engine room having a low noise structure, solves a problem caused by insufficient ventilation, and pumps the engine room. An object of the present invention is to provide an engine device that is not affected by oil leakage in a room.

[0013]

According to a first aspect of the present invention, there is provided an engine compartment for accommodating an engine, a partition wall surrounding the engine compartment, and an engine arranged on one side of the engine compartment via the partition wall. A pump chamber that houses the hydraulic pump to be driven, a compressor that is installed in the engine chamber and that is driven by the engine to compress the air that has been sucked in from the outside of the partition wall and supply it to the engine chamber, and an air suction of the compressor from outside the partition wall This is an engine device that has an intake pipe that is installed up to the mouth, and the compressor in the engine room forcibly blows the air sucked from outside the partition wall through the intake pipe into the engine room to reduce noise. Sufficient ventilation is possible even in the engine room of the structure, the temperature inside the engine room is lowered, and the temperature inside the engine room rises due to insufficient ventilation. In addition to solving the above problem, the engine chamber contains the oil content even if oil leaks in the pump chamber by keeping the engine chamber pressure higher than the pump chamber pressure by the compressed air pressurized and supplied by the compressor. Prevents the possibility of blowing air from the pump room.

According to a second aspect of the present invention, in the engine device according to the first aspect, the compressed air discharged from the compressor is provided with an air ejecting section for blowing the object to be cooled most in the engine compartment. The air ejecting section blows compressed air from the compressor onto the object to be cooled in the engine compartment, thereby efficiently cooling the object to be cooled, which is weak to high temperatures.

According to a third aspect of the present invention, in the engine device according to the first or second aspect, the engine room pressure boosted by externally pressurizing and supplying the external air into the engine room is made equal to or higher than the pump room pressure. It is equipped with an air discharge means for forcibly discharging the air in the engine room within the range that can be maintained.In the engine room, the supply of compressed air from the compressor and the forced discharge of air by the air discharge means are performed at the same time. Therefore, more sufficient ventilation is possible, and the air discharge means discharges the air in the engine room within a range in which the engine room pressure boosted by the compressed air supplied from the compressor can be maintained at the pump room pressure or higher. Even if oil leaks in the pump chamber, it is possible to prevent the engine chamber from sucking air containing the oil from the pump chamber.

[0016]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in detail below with reference to the embodiment shown in FIG.

As shown in FIG. 1, an engine room 22 for accommodating the engine 21 is surrounded by a partition wall body (enclosure) 23 having a sound insulating property.

A partition wall on one side of the central engine compartment 22
Hydraulic pump 2 driven by engine 21 via 23a
A pump chamber 25 accommodating 4 is arranged. A part of the engine room peripheral cover 26 provided on the upper part of the pump room 25 is provided so as to be opened and closed by an operator.

Further, with respect to the engine room 22 at the center, the cooling device chamber 2 accommodating the cooling device 27 through the partition wall 23b on the other side.
8 are arranged. The partition walls 23a and 23b are a part of a series of partition walls 23 surrounding the engine compartment 22.

The cooling device 27 is a radiator for further cooling cooling water which is a cooling medium for cooling the engine 21,
A heat exchanger such as an oil cooler for cooling the hydraulic oil of the hydraulic circuit supplied from the hydraulic pump 24 is integrated, and a cooling fan 29 is provided on the engine room 22 side of these heat exchangers. Is.

The drive means 30 for the cooling fan 29 may be a hydraulic motor, but in the case of hydraulic drive, there is a risk of adverse effects on the engine compartment 22 when an oil leak occurs, so an electric motor is used. It is desirable to drive with.

In the engine room 22, together with the engine 21,
An engine controller 31 is installed as a cooling object for controlling the operating state of the engine 21.
A muffler 32 that muffles exhaust noise generated from the engine 21 is arranged above the engine 21.

Further, a muffler is provided above the engine compartment 22.
An air exhausting means 33 for engine room ventilation for forcibly exhausting air in the engine room by utilizing the momentum of the exhaust gas flow exhausted from 32 is mounted.

The air discharge means 33 includes a small-diameter cylindrical muffler chimney portion 34 drawn from the muffler 32 and a large-diameter cylindrical exhaust pipe 35 protruding above the engine compartment upper cover 40.
Is an ejector in which and are concentrically fitted via a gap.

In the air discharge means 33, a negative pressure lower than atmospheric pressure is generated around the muffler exhaust gas flow ejected from the engine 21 through the muffler 32 into the exhaust pipe 35 through the muffler chimney portion 34. By utilizing this negative pressure generation phenomenon, it has an ejector function of sucking the air in the engine room 22 from the gap 36 to the negative pressure generating part, and the air in the engine room 22 can be forcibly sucked and ventilated. it can.

In the cooling device chamber 28, the partition wall 23
A baffle plate on the side opposite to b is provided with a blow-in port 37 for blowing in external air, and is obliquely above the cooling fan 29 to discharge the cooling air blown from the cooling fan 29 to the outside. A wind vent 38 is provided.

The partition wall 23b between the engine room 22 and the cooling device room 28 has a sloping plate part 39 which is bent toward the engine room 22 side above the center part thereof. It is formed so that the air flow from the cooling fan 29 to the exhaust port 38 becomes smooth.

Further, in the engine room 22, there is installed a compressor 41 which is driven by the engine 21 and which compresses the air sucked from the outside and supplies the compressed air into the engine room 22.

The power of the compressor 41 is obtained from the rotary shaft (not shown) of the engine crank via a belt type transmission mechanism (not shown).

Further, the intake air to the compressor 41 is piped in consideration of taking in fresh air from the outside of the engine room 22, and as shown in FIG. The intake pipe 42 drawn in is connected to the air intake port 43 of the compressor 41.

On the other hand, the compressed air discharge port 44 of the compressor 41
Is connected to a nozzle 45 as an air ejection portion, and the tip of the nozzle 45 is opened to face the object to be cooled most that requires the most cooling in the engine room 22, and the low temperature compressed air from the compressor 41 is discharged. The length, direction, etc. of the nozzle 45 are provided so that the nozzle 45 can directly spray the object to be cooled.

In the example shown in FIG. 1, the wind direction of the nozzle 45 is aligned with the engine controller 31 that is weak to high temperature and requires the most cooling, and is arranged with a predetermined separation distance.

In the piping system of the compressor 41, a pressure accumulating tank (not shown) for smoothing pressure fluctuations of the compressed air, or a heat exchanger for cooling the compressed air whose temperature has been raised by pressurization by the compressor 41. (Not shown) may be provided. These accumulator tanks and heat exchangers may be installed as needed.

In this way, the compressor 41 installed in the engine room 22 takes in the external air into the engine room 22 through the intake pipe 42 and pressurizes and supplies it into the engine room 22, so that the engine room pressure rises. It will be.

Here, the amount of air discharged by the air discharge means 33 is such that the engine room pressure boosted by the compressor 41 supplying the external air into the engine room 22 can be kept above the pump room pressure. It is regulated to forcibly discharge the air inside 22.

In other words, since the air discharge means 33 forcibly discharges the air in the engine room 22 to the outside, it works to lower the engine room pressure. Since the compressor 41 has a smaller amount of compressed air blown into the engine room 22, the engine room pressure in the engine room 22 does not become a negative pressure lower than the pump room pressure (atmospheric pressure).

Further, on one side and the other side of the body,
Since step 47 is provided as a foothold for workers,
On this step 47, the operator covers the engine compartment.
Open 26 etc. and perform maintenance work inside the pump room 25 etc.

Next, the function and effect of the embodiment shown in FIG. 1 will be described.

When the cooling fan 29 of the cooling device 27 rotates,
The cooling fan 29 promotes heat exchange in the radiator and the oil cooler of the cooling device 27 by the external air blown from the blowing port 37, and cools the engine cooling water and the hydraulic oil in the hydraulic circuit. The air whose temperature has risen by exchanging heat with the high-temperature engine cooling water and the hydraulic oil is exhausted to the outside from the upper exhaust port 38.

In parallel with the cooling by the cooling device 27, the engine 21 drives the compressor 41 in the engine chamber 22, and the compressor 41 sucks the air outside the partition wall 23 through the intake pipe 42 and compresses it. , The nozzle 45 is forced to blow compressed air into the engine compartment 22.

At this time, low-temperature compressed air is blown from the nozzle 45 toward the engine controller 31 to directly cool the engine controller 31, and the cooling air that has passed through the engine controller 31 is supplied to the entire engine compartment 22. .

At the same time, the air exhaust means 33 allows the engine room
Since the air inside 22 is forcibly discharged to the outside, sufficient ventilation is possible even in the engine room 22 surrounded by the partition wall body 23 of the noise reduction structure, and the temperature inside the engine room 22 is lowered by this ventilation, It is possible to solve the problem associated with the temperature rise in the engine room 22 that occurs when ventilation is insufficient.

That is, in the engine room 22, the compressed air is supplied from the compressor 41 and the air is forcibly discharged by the air discharging means 33 at the same time, so that the ventilation is more sufficient than the case where only one of them is carried out. With the engine controller 31 and the engine 21 and muffler.
32 can be cooled effectively.

At this time, the air discharging means 33 and the compressor
The balance between the supply and discharge amount with 41 is such that the amount of air forcedly blown into the engine chamber 22 from the compressor 41 is larger than the amount of air forcedly discharged from the engine chamber 22 by the air discharge means 33. By controlling, the boosting control is performed such that the engine room pressure in the engine room 22 is slightly higher than the pump room pressure in the pump room 25.

As a result, even if oil should leak from the hydraulic pump 24 or the like in the pump chamber 25, the engine chamber 22 of relatively high pressure will pass from the pump chamber 25 of low pressure through the gap such as the partition wall 23a. Air containing oil cannot be sucked in, and there is no risk of oil adhering to the high temperature muffler 32 or the like.

In addition, since the compressor 41 forcibly supplies the air, it is not necessary to form an opening hole for directly sucking the atmosphere in the bottom of the partition wall 23 in the engine compartment 22. The reduction effect can be maintained.

Next, the following effects can be obtained by adopting the structure shown in FIG.

By supplying the compressed air from the compressor 41 into the engine compartment 22 under pressure, the outside air having a temperature lower than the atmosphere in the engine compartment 22 can be positively taken into the engine compartment 22. By increasing the ventilation performance of, the ambient temperature in the engine room 22 can be lowered, and the reliability of the engine room equipment can be improved.

At this time, the low-temperature compressed air ejected from the nozzle 45 is directly blown as cooling air to the engine room equipment as the object to be cooled most in the engine room 22, for example, the engine controller 31. As a result, it is possible to efficiently cool even the indoor equipment of the engine, which is vulnerable to high temperatures, so that the reliability can be further improved.

By supplying the compressed air from the compressor 41 to the engine compartment 22, the outside air having a temperature lower than that in the engine compartment 22 can be positively taken into the engine compartment 22 through the intake pipe 42. The temperature rise of the engine room peripheral cover 26 on the pump chamber 25 and the pump room 25 can be suppressed, and it is easy for an operator who opens the engine room peripheral cover 26 to work.

By supplying the compressed air from the compressor 41 to the engine room 22, the pressure inside the engine room 22 is increased, so that the ejector function of the air discharging means 33 can be enhanced, that is, the ventilation performance can be enhanced. .

By supplying the compressed air from the compressor 41 to the engine chamber 22, the pressure inside the engine chamber 22 is increased, so that the engine chamber 22 when an oil leak occurs from the hydraulic pump 24 in the pump chamber 25 or the like. It is possible to prevent oil from entering inside.

As described above, the compressor 41, which is installed separately from the cooling fan 29 of the cooling device 27, forcibly blows the air sucked from the outside of the partition wall 23 into the high-temperature engine compartment 22 to protect the equipment inside the engine. Since the air that has been cooled and warmed by this cooling is forcibly discharged to the outside by the air discharge means 33, the engine room having the structure for reducing noise by the partition wall 23
Even in 22, the sufficient ventilation can be secured, the temperature in the engine room 22 can be efficiently lowered, and the reliability of the engine room equipment is reduced due to the temperature increase in the engine room 22 caused by insufficient ventilation. Prevents the engine controller 31
It is possible to improve reliability such as.

[0054]

According to the first aspect of the present invention, the compressor in the engine compartment forcibly blows the air sucked from the outside of the partition through the intake pipe into the engine compartment. Sufficient ventilation is possible even in the engine room, and the temperature inside the engine room can be lowered.
It is possible to solve the problems associated with the temperature rise in the engine room that occurs when ventilation is insufficient, and to maintain the engine room pressure higher than the pump room pressure by the compressed air that is compressed and supplied into the engine room by the compressor. Even if oil leaks, it is possible to prevent the engine compartment from blowing air containing the oil from the pump compartment.

According to the second aspect of the present invention, the air ejecting section blows the compressed air from the compressor onto the object to be cooled in the engine compartment, thereby efficiently cooling the object to be cooled, which is weak to high temperature.

According to the third aspect of the invention, in the engine room, the supply of the compressed air from the compressor and the forced discharge of the air by the air discharging means are performed at the same time, so that more sufficient ventilation becomes possible. Also, since the air discharge means discharges the air in the engine room within a range in which the engine room pressure boosted by the compressed air supplied from the compressor can be maintained at or above the pump room pressure, even if oil leakage occurs in the pump room, It is possible to prevent the engine room from inhaling the air containing the oil from the pump room.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of an engine device according to the present invention.

FIG. 2 is a front view of a hydraulic excavator.

3 is a cross-sectional view of a conventional engine device showing a cross section taken along the line III-III of FIG.

[Explanation of symbols]

21 engine 22 Engine compartment 23,23a bulkhead 24 hydraulic pump 25 pump room 31 Engine controller as the object to be cooled most 33 Air discharge means 41 Compressor 42 Intake pipe 45 Nozzle as air jet

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Tsuji             4-10-1, Yoga, Setagaya-ku, Tokyo             Within Mitsubishi Corporation (72) Inventor Seiya Nuki             4-10-1, Yoga, Setagaya-ku, Tokyo             Within Mitsubishi Corporation F-term (reference) 2D015 CA02 CA03

Claims (3)

[Claims] 1. An engine chamber for accommodating an engine, a partition wall surrounding the engine chamber, a pump chamber for accommodating a hydraulic pump driven by the engine and arranged on one side of the engine chamber via the partition wall, and an engine chamber. A compressor that is driven by the engine to compress the air sucked from the outside of the partition wall and supplies the compressed air to the engine compartment; and an intake pipe that is arranged from the outside of the partition wall to the air intake port of the compressor. Characteristic engine device. 2. The engine device according to claim 1, further comprising an air ejecting unit that blows the compressed air discharged from the compressor onto an object to be cooled most in the engine chamber. 3. An air discharge means for forcibly discharging the air in the engine room within a range in which the engine room pressure boosted by pressurizing and supplying external air into the engine room by a compressor can be maintained. The engine device according to claim 1 or 2, characterized in that.