JP2003328767A - 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. An air suction means 41 is installed in the engine room 22 to boost the air pressure in the engine room 22 by forcibly sucking outside air in the engine room 22. The air suction means 41 has a directional characteristic to jet the air sucked forcibly into the engine room 22 in a specific direction. The exhaust air section of the engine room 22 is provided with an air exhaust means 33 for exhausting the air in the engine room 22 outside forcibly by an ejector effect. <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 area of the opening on the air intake side into the engine room 11 is made narrow, and the inside of the engine room 11 is exposed through a slight gap between the engine room covers and partition walls. Since only air is sucked in, the inside of the engine compartment 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 accommodating a driven hydraulic pump, an air suction means for forcibly sucking outside air into the engine chamber to raise the engine room pressure, and an engine room pressure boosted by the air suction means to be higher than the pump chamber pressure. It is an engine device provided with an air discharge means for forcibly discharging the air in the engine room within a range where it can be kept, and while external air is forcibly sucked into the engine room by the air suction means, the air in the engine room is discharged by the air discharge means. By forcibly discharging, sufficient ventilation is possible even in the engine room with a low noise structure, and the temperature inside the engine room is lowered by external air, In addition to solving the problems associated with the temperature rise in the engine room that occurs when the air is insufficient, the air discharge means keeps the air in the engine room within a range in which the engine room pressure boosted by the air suction means can be maintained at or above the pump room pressure. Since the oil is discharged, even if oil leaks in the pump chamber, it is possible to prevent the engine room from sucking air containing the oil from the pump chamber.

According to a second aspect of the present invention, the air suction means in the engine device according to the first aspect has a direction in which the air forcedly sucked into the engine chamber is ejected in a specific direction. Due to the directivity of the air suction means for ejecting air in a specific direction, the engine room equipment, which is particularly vulnerable to high temperatures, is efficiently cooled.

According to a third aspect of the invention, the air discharge means in the engine device according to the first or second aspect of the invention forcibly discharges the air in the engine room by utilizing the flow of the exhaust gas discharged from the engine. It is an ejector, and the pressure in the engine chamber is increased by the air sucked into the engine chamber by the air suction means.Therefore, the ejector effect of forcibly discharging the engine room air by using the flow of exhaust gas from the air discharge means is increased. The ventilation performance of is improved.

[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.

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 for controlling the operating state of the engine 21 is installed. 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
The baffle on the side opposite to b is provided with a suction port 37 for sucking external air, and diagonally above the cooling fan 29, for discharging the cooling air blown from the cooling fan 29 to the outside. An exhaust port 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, an air suction means 41 for forcibly sucking the external air into the engine room 22 to raise the engine room pressure in the surplus space at the bottom thereof.
Is installed.

The amount of external air that is forcibly sucked into the engine compartment 22 by the air suction means 41 is the same as the air discharge means.
The amount of air is controlled to be larger than the amount of air forcedly discharged from the engine room 22 by 33.

In short, the air discharge means 33 forcibly discharges the air in the engine compartment 22, but the discharge amount is
The engine chamber pressure boosted by the air suction means 41 is regulated within a range in which it can be maintained above the pump chamber pressure (atmospheric pressure).

In the air suction means 41, an intake hole 42 is provided in the bottom plate of the engine chamber, a suction fan 43 is arranged inside the intake hole 42, and an electric motor 44 is installed as a drive source of the suction fan 43. Further, a fan cover 46 provided with a vent hole 45 for ejecting air toward the engine controller 31 is installed.

As a drive source for the suction fan 43, not only the electric motor 44 but also a hydraulic motor can be used. However, in the case of hydraulic drive, when an oil leak occurs, the engine room 22
Since the oil scattered inside may come into contact with high temperature parts,
Electric motor 44 is preferred.

The blower hole 45 is provided in a part of the fan cover 46 and has a direction to blow out the air forcedly sucked into the engine compartment 22 by the suction fan 43 in a specific direction. If you add a nozzle to this fumarole 45,
It is possible to further clarify the directionality when injecting air.

Regarding the installation position of the air suction means 41, it is desirable to install the air suction means 41 at a place where the low-temperature external air can be directly injected toward the object to be cooled. In the embodiment shown in FIG. Although the air suction means 41 is installed so as to match the wind direction to 31, it is not limited to this form.

Steps 47 are provided on one side and the other side of the machine body as scaffolds for the operator. On this step 47, the operator opens the engine room peripheral cover 26 and the like, Perform maintenance work such as inside the pump room 25.

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 sucked from the suction 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.

Simultaneously with the cooling by the cooling device 27, the suction fan 43 of the air suction means 41 is driven by the electric motor 44, and low-temperature external air is supplied from the intake hole 42 provided in the engine room bottom plate to the engine. The air is forcibly sucked into the chamber 22 and then ejected from the fumes 45 toward the engine controller 31 to directly cool the engine controller 31, and the air in the engine chamber 22 is forced to the outside by the air discharge means 33. By discharging, the ventilation in the engine compartment 22 is promoted, and the engine 21, the muffler 32, and the like are cooled together with the engine controller 31.

At this time, the air discharge means 33 and the air suction means
The performance balance with 41 is that the amount of external air that is forcibly sucked into the engine chamber 22 by the suction fan 43 of the air suction unit 41 is greater than the amount of air that is forcedly discharged from the engine chamber 22 by the air discharging unit 33. By controlling so that
The engine compartment 22 is pressurized to a pressure slightly higher than atmospheric pressure.

As a result, the pressure can be controlled so that the pressure inside the engine chamber 22 is slightly higher than that inside the pump chamber 25 at atmospheric pressure.
Even if oil leaks from the hydraulic pump 24 in the pump chamber 25, air containing oil enters the high pressure engine chamber 22 from the relatively low pressure pump chamber 25 through the gap such as the partition wall 23a. There is no possibility that oil will come into contact with the hot muffler 32 or the like.

Moreover, since the suction fan 43 works to eliminate noise such as engine sound that leaks from the inside of the engine compartment 22 to the outside through the intake hole 42, the noise reduction effect of the partition wall body 23 is maintained. .

Next, the air discharge means 33 and the air suction means
List 41 effects.

By raising the pressure in the engine compartment 22 by the external air sucked by the suction fan 43 of the air suction means 41, the ejector effect of the air discharge means 33 can be enhanced, that is, the ventilation performance can be enhanced.

By increasing the ventilation performance with the suction fan 43 or the like, the outside air having a temperature sufficiently lower than that in the engine room 22 can be positively taken in and the temperature in the engine room 22 can be efficiently lowered. The reliability of the components inside 22 can be improved.

At this time, since the cooling air blown from the suction fan 43 installed in the engine room 22 is directly blown to the equipment to be cooled, it is possible to efficiently cool even the equipment in the engine that is not familiar with the high temperature, which is more reliable. It is possible to improve the property.

Since the intake fan 43 positively takes in outside air at a temperature lower than that in the engine room 22, the engine room upper cover 40 and the engine room peripheral cover on the pump room 25 are covered.
The temperature rise of 26 can be suppressed, and this engine room peripheral cover 26
It is easy for workers to open a part of the work.

The suction fan 43 of the air suction means 41 sucks a larger amount of air into the engine compartment 22 than the air quantity discharged by the air discharge means 33 and boosts the pressure in the engine compartment 22. When oil leaks from the hydraulic pump 24 or the like, it is possible to prevent oil from entering the engine compartment 22.

Unlike the hydraulic motor, the electric motor 44 that drives the suction fan 43 does not have the possibility of oil leakage in the engine compartment 22, so that the high temperature portion in the engine compartment 22 is prevented from being oiled. it can.

As described above, the low temperature outside air is forcibly sucked into the high temperature engine compartment 22 by the suction fan 43 of the air suction means 41 which is installed separately from the cooling fan 29 of the cooling device 27, and engine room equipment And the air warmed by this cooling is forcibly discharged to the outside by the air discharge means 33.
Even in 22, the sufficient ventilation can be secured, the temperature in the engine room 22 can be efficiently lowered by the outside air, and the reliability of the engine room equipment accompanying the temperature rise in the engine room 22 that occurs when ventilation is insufficient Of the engine controller 31 and the like, and the reliability of the engine controller 31 and the like can be improved.

In the embodiment shown in FIG. 1, an example in which the air suction means 41 is installed at the bottom of the engine room 22 is shown, but in short, the wall surface of the partition wall 23 surrounding the engine room 22 and the like. If there is a surplus space in the engine compartment 22 where air can be taken in, it is advisable to effectively utilize that location and install the air suction means 41 such as the suction fan 43.

[0051]

According to the first aspect of the present invention, the external air is forcibly sucked into the engine room by the air suction means, and the air in the engine room is forcibly discharged by the air discharge means, thereby reducing the noise. Ventilation is possible even in the engine room having the chemical structure, and the temperature inside the engine room is lowered by the outside air, and the problems associated with the temperature rise inside the engine room caused by insufficient ventilation can be solved. Further, since the air discharge means discharges the air in the engine room within a range where the engine room pressure boosted by the air suction means can be maintained at the pump room pressure or higher, even if oil leakage occurs in the pump room, It is possible to prevent the possibility that air containing air will be sucked from the pump chamber.

According to the second aspect of the invention, due to the directionality of the air suction means for ejecting air in a specific direction,
In particular, it is possible to efficiently cool and protect the engine indoor equipment that is vulnerable to high temperatures.

According to the third aspect of the present invention, since the pressure in the engine chamber is increased by the air sucked into the engine chamber by the air suction means, the air discharge means uses the flow of exhaust gas to force the air in the engine room. The ejector effect to be discharged can be enhanced, and the ventilation performance in the engine room can be improved.

[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 33 Air discharge means 41 Air suction means

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Tsuji             4-10-1, Yoga, Setagaya-ku, Tokyo             Within Mitsubishi Corporation

Claims (3)

[Claims] 1. An engine compartment for accommodating an engine, a partition wall surrounding the engine compartment, a pump compartment for accommodating a hydraulic pump driven by the engine and disposed on one side of the engine compartment through the partition body, and an engine compartment. The air suction means for forcibly sucking the outside air into the engine to raise the engine room pressure, and the air forcibly exhausting the air in the engine room within the range where the engine room pressure boosted by the air suction means can be kept above the pump room pressure. An engine device comprising: an ejecting unit. 2. The engine device according to claim 1, wherein the air suction means has a directivity for ejecting the air forcedly sucked into the engine chamber in a specific direction. 3. The air discharging means is an ejector for forcibly discharging the air in the engine room by utilizing the flow of exhaust gas discharged from the engine.
Or the engine device according to 2.