JPH09125957A - Internal combustion engine cooling system - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To improve cooling efficiency by improving the flow of cooling air in a machine room and to efficiently cool an oil pan or the like of an engine. A bottom plate portion 8A and a engine 11 in a machine room 8
An exhaust duct 21 is provided between the exhaust duct 21 and the lower side of the. And
One end side of the exhaust duct 21 is used as an opening 21A, and the oil pan 15 is opened obliquely upward on the left side. Also,
The other end 21B of the exhaust duct 21 is arranged on the bottom plate portion 8A of the machine room 8 so as to cover the outlets 10 from above. An auxiliary fan 22 is provided in the opening 21A of the exhaust duct 21 to discharge the cooling air flowing in the machine chamber 8 in the direction of the arrow B1 from each outlet 10 to the outside.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling device for an internal combustion engine used in construction machines such as hydraulic excavators and hydraulic cranes, and more particularly to a cooling device for an internal combustion engine that cools a power chamber using a cooling fan.

[0002]

2. Description of the Related Art Generally, a power chamber in which an air inlet and an air outlet are formed, an internal combustion engine provided between the inlet and the air outlet and provided in the power chamber, and A cooling device for an internal combustion engine, which is located on the inlet side and is provided in the power chamber and includes a cooling fan and a radiator for cooling the internal combustion engine, is widely known, for example, from Japanese Utility Model Publication No. 6-40317.

Here, a case where a cooling device for an internal combustion engine according to this type of conventional technology is used for a hydraulic excavator will be described with reference to FIGS. 6 and 7.

In the drawing, 1 is a lower traveling body provided with a traveling hydraulic motor (not shown) and the like, and 2 is the lower traveling body 1.
The revolving device 2 is provided on the upper surface side of the revolving device 2. The revolving device 2 includes a revolving hydraulic motor (not shown) provided on an upper revolving superstructure 3 described later. Reference numeral 3 denotes an upper revolving structure rotatably mounted on the lower traveling structure 1 via the revolving device 2, and the upper revolving structure 3 includes a revolving frame 4 having a frame structure and a front side of the revolving frame 4. Cab 5 provided in
And a counterweight 6 provided on the revolving frame 4 located on the rear side of the operator's cab 5, and a machine room 8 described later.

Reference numeral 7 denotes a working device provided at the front part of the upper swing body 3. The working device 7 is a boom 7A rotatably provided at the front part of the swing frame 4, and a tip side of the boom 7A. And an arm 7B rotatably provided to the arm 7B.
And a backhoe-type bucket 7C that is provided so as to be able to move up and down on the tip side of the boom 7A, the arm 7B, and the bucket 7C are respectively operated by a boom cylinder 7D, an arm cylinder 7E, and a bucket cylinder 7F. Is.

Reference numeral 8 denotes a machine room as a power room. The machine room 8 is located on the rear side of the operator's cab 5 and is provided on the revolving frame 4. Inside the machine room 8, an engine 11, which will be described later,
Cooling fan 12, radiator 13 and hydraulic pump 16
Etc. are accommodated. As shown in FIG. 7, the machine room 8 includes a bottom plate portion 8A located on the bottom side, side plate portions 8B, 8B, ... Standing on the left and right sides of the bottom plate portion 8A, and the side plate portions. It is configured in a box shape from a top plate portion 8C provided on the upper portion of 8B.

.. indicate a plurality of inlets for introducing cooling air into the machine room 8. Each of the inlets 9 is located on the left side of a radiator 13 housed in the machine room 8 and described later. , The top plate portion 8C is provided with a plurality of slit-shaped openings. Then, each inflow port 9 is arranged in the top plate portion 8C of the machine room 8 with a constant inclination angle toward the radiator 13 so as to guide the outside air as cooling air in the direction of the arrow A.

[0008] Reference numerals 10, 10, ... Show a plurality of outlets formed in the bottom plate portion 8A. The respective outlets 10 are located on the rear portion 11C side of the engine 11, which will be described later, and the bottom plate portion 8 of the machine room 8 is provided.
It is formed by providing a plurality of slit-shaped openings in A. Each of the outlets 10 is opened below the engine 11 with a certain inclination angle so that the cooling air flowing in the machine room 8 in the directions of arrows B1 and B2 can be directed toward the bottom plate 8A of the machine room 8. It is designed to be leaked from the outside.

Reference numeral 11 denotes an engine serving as an internal combustion engine provided in the machine room 8. A cooling fan 12, a radiator 13 and the like, which will be described later, are arranged on the front portion 11A side of the engine 11, and the output of the engine 11 is provided. Shaft 11B is cooling fan 1
2 is rotationally driven. Further, an oil pan 15 described later is arranged on the lower side of the rear portion 11C side of the engine 11, and a hydraulic pump 1 described later is disposed on the rear end side.
6, exhaust pipe 17 and the like are attached. The engine 11 is fixed on the swivel frame 4 via an engine mount 11D, and the bottom plate portion 8A of the machine room 8 is fixed.
It is arranged above.

Reference numeral 12 denotes a cooling fan which is attached to the output shaft 11B of the engine 11 and is located on the side of each inlet port 9. The cooling fan 12 is driven by the rotation of the engine 11 to take in outside air from each inlet port 9. The cooling air for cooling the engine 11, etc. is generated in the machine room 8.

Reference numeral 13 denotes a radiator provided on the side of each of the inflow ports 9 and provided in the machine room 8, and the radiator 13 is provided.
Is composed of a circulation pipe through which cooling water circulates, and a large number of cooling fins (none of which are shown) provided in the circulation pipe,
It is connected to a water jacket (not shown) of the engine 11 via each cooling water pipe 14 which will be described later and forms a circulation passage for the cooling water. Then, the radiator 13 cools this cooling water by the cooling fan 12 while circulating the cooling water heated to a high temperature by the engine 11 in the distribution pipe.

Reference numerals 14 and 14 designate an engine 11 and a radiator 1.
3 shows a cooling water pipe connected to 3 and each cooling water pipe 1
4 is the radiator 1 for cooling water that has become hot in the engine 11.
It is a circulation path for the cooling water which is led to the engine 3 and returns the cooling water cooled again by the radiator 13 to the engine 11 side.

Reference numeral 15 denotes an oil pan fixed to the lower side of the rear portion 11C of the engine 11 and forming a part of the engine 11. The oil pan 15 is formed as a substantially convex container projecting downward. Reference numeral 15 circulates the lubricating oil (engine oil) contained therein to the crank chamber (not shown) of the engine 11.

Reference numeral 16 denotes a hydraulic pump arranged on the rear portion 11C side of the engine 11, and the hydraulic pump 16 is rotationally driven by the engine 11 so that each of the cylinders 7
Pressure oil is supplied to D, 7E, 7F and each hydraulic motor.

Reference numeral 17 denotes an exhaust pipe connected to the rear portion 11C side of the engine 11, the exhaust pipe 17 projecting from the rear portion 11C side of the engine 11 in a substantially horizontal direction, and the tip end side thereof becomes a chimney portion 17A and goes upward. It is extended. The upper end of the chimney portion 17A of the exhaust pipe 17 is the top plate portion 8 of the machine room 8.
The exhaust gas generated by the combustion of the engine 11 is discharged to the outside by penetrating through C and opening to the outside. Reference numeral 18 denotes a muffler provided in the middle of the exhaust pipe 17, and the muffler 1
8 is the exhaust sound (noise) of the exhaust gas flowing through the exhaust pipe 17.
Is to be reduced.

The hydraulic excavator according to the prior art has the above-mentioned structure. When the hydraulic pump 16 is driven by the engine 11 in the machine room 8, the hydraulic pump 16 presses a hydraulic pipe (not shown). Discharge the oil. Then, the pressure oil from the hydraulic pump 16 is supplied to and discharged from the traveling hydraulic motor of the lower traveling structure 1, the swing hydraulic motor of the swing device 2, the cylinders 7D, 7E, 7F of the working device 7 and the like, whereby the hydraulic excavator is excavated. It is designed to perform work such as traveling, turning, and excavation.

When the cooling fan 12 is rotated by the driving of the engine 11, the outside air is sucked in the direction of the arrow A through each inlet 9, and the cooling air is generated in the machine room 8.
The cooling air passes through the radiator 13 before and after it cools the cooling water circulating in the radiator 13 and indirectly cools the engine 1 by the cooling water.
Cool 1 On the other hand, when this cooling air flows around the engine 11 in the directions of arrows B1, B2, and B3, the oil pan 1 disposed around the main body of the engine 11 and its surroundings.
5, while cooling the hydraulic pump 16, the exhaust pipe 17, etc.,
It is discharged from the outlets 10 of the machine room 8 in the direction of arrow C to the outside.

[0018]

By the way, in the hydraulic excavator according to the above-mentioned conventional technique, the engine 11 and the cooling fan 1 are installed in the machine room 8 due to the limitation of the volume of the machine room 8.
2, in addition to the radiator 13, the exhaust pipe 17, etc., the hydraulic pump 16 driven by the engine 11, the hydraulic pipe, etc. are accommodated, so that the inside of the machine room 8 is indicated by arrows A, B1,
The shape of the flow passage for the cooling air flowing in the B2 direction or the like becomes complicated, and the pressure loss resistance (pressure loss) increases, so that the engine 11
There is a problem that sufficient cooling air cannot be circulated to the rear portion 11C side.

Particularly in recent hydraulic excavators, in order to reduce noise during work, etc., there is a tendency to increase the degree of airtightness of the machine room 8 for accommodating the engine 11, which is a main noise source. The machine room 8 is communicated with the outside only through the inlet 9 and the respective outlets 10 to prevent engine sound and the like from leaking to the outside from other locations.

Therefore, in the prior art, it is difficult to suck sufficient cooling air into the machine chamber 8 through the outlets 9 only by the cooling fan 12 driven by the output shaft 11B of the engine 11, and There is a problem that the oil pan 15, the hydraulic pump 16 and the like cannot be effectively cooled on the rear portion 11C side of 11. Further, in this case, if an attempt is made to increase the rotation speed of the cooling fan 12, it becomes necessary to increase the rotation speed of the engine 11 that drives the cooling fan 12, resulting in a large power loss.

On the other hand, for example, in Japanese Patent Laid-Open No. 5-288053, an intake fan is provided on the inlet side of the cooling air, which is the front side of the radiator, through a duct opening to the front side of the hydraulic excavator, and this intake air is taken in. There has been proposed a cooling device for a construction machine (hereinafter, referred to as another conventional technique) in which the amount of the cooling air in the machine room 8 is increased by sucking the cooling air with a fan.

However, in the other prior art, although a duct or an intake fan can be installed in the case of a large hydraulic excavator, it is located on the front side of the radiator for a small or medium-sized hydraulic excavator. It is difficult to install a duct and an intake fan, and because the duct is opened on the front side of the hydraulic excavator that performs work such as excavation, dust such as earth and sand rolled up with a bucket, etc. is sucked into the duct. There is a problem that it is easy to invade through the fan, the filter arranged on the front side of the radiator 13 is clogged early, and the amount of cooling air cannot necessarily be effectively increased.

The present invention has been made in view of the above-mentioned problems of the prior art. It is possible to increase the flow rate of the cooling air flowing in the machine chamber, improve the cooling efficiency, and to improve the oil pan and hydraulic pump of the engine. An object of the present invention is to provide a cooling device for an internal combustion engine that can be effectively cooled.

[0024]

In order to solve the above-mentioned problems, the present invention according to claim 1 provides a power chamber in which an air inlet and an outlet are formed, and the inlet and the outlet. An internal combustion engine that is located between the internal combustion engine and the power chamber, and an internal combustion engine that is located inside the power chamber on the inlet side of the power chamber and that cools the internal combustion engine and a radiator. In the cooling device described above, an auxiliary fan that is located below the internal combustion engine and that increases the amount of cooling air that flows in the power chamber is provided in the power chamber.

In this case, as in the invention described in claim 2, an exhaust duct is provided in the power chamber, one end side of which opens below the internal combustion engine and the other end side of which communicates with the outflow port. The auxiliary fan may be provided in the exhaust duct.

According to a third aspect of the present invention, the power chamber in which the air inlet is formed, the internal combustion engine provided in the power chamber, and the power chamber located on the inlet side of the power chamber are provided. In a cooling device for an internal combustion engine, which is provided in a room and comprises a cooling fan and a radiator for cooling the internal combustion engine, the power chamber is located on the opposite side of the cooling fan with the internal combustion engine interposed therebetween, An exhaust duct that opens upward to the outside of the chamber is provided, and an auxiliary fan that increases the amount of cooling air that flows in the power chamber is provided in the exhaust duct.

In this case, as in the invention described in claim 4, the upper end side of the exhaust duct surrounds the exhaust pipe of the internal combustion engine from the outside at least at the tip end side, and the exhaust pipe and the exhaust pipe are located above the power chamber. It may be configured to open.

[0028]

With the above construction, in the invention described in claim 1,
Since the auxiliary fan is provided in the power chamber below the internal combustion engine, the cooling air sucked into the power chamber from the inlet by the cooling fan is sent to the lower side of the internal combustion engine by the auxiliary fan, and inside the power chamber. The air can be efficiently discharged to the outside without staying, and the amount of cooling air flowing through the power chamber can be increased.

In this case, as in the invention described in claim 2, the exhaust duct communicating from the lower side of the internal combustion engine to the outlet is provided, and the auxiliary fan is disposed in the exhaust duct, whereby the internal combustion engine The flow of cooling air toward the lower side of the internal combustion engine can be generated more reliably, and the volume of the cooling air flowing through the lower side of the internal combustion engine can be further increased.

Further, in the third aspect of the present invention, since the exhaust duct that opens upward is provided on the side opposite to the cooling fan across the internal combustion engine, and the auxiliary fan is disposed in the duct. The cooling air sucked from the inlet by the cooling fan can be efficiently circulated around the internal combustion engine, and can be discharged to the upper side of the power chamber through the exhaust duct. The amount of cooling air can be increased by (on the opposite side of the cooling fan) or the like.

In this case, as in the invention described in claim 4, the exhaust duct surrounds the exhaust pipe from the outside at the upper end side thereof, and is constructed so as to open above the power chamber together with the exhaust pipe. The flow rate of the exhaust gas discharged from the exhaust pipe can be used to increase the amount of cooling air in the exhaust duct, thereby further increasing the amount of cooling air flowing through the rear side of the internal combustion engine or the like.

[0032]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. In each embodiment, the same components as those of the above-mentioned conventional technique are designated by the same reference numerals, and the description thereof will be omitted.

Here, FIG. 1 shows a first embodiment of the present invention.

In the figure, reference numeral 21 denotes an exhaust duct provided below the engine 11 in the machine room 8, and the exhaust duct 21 is
For example, it is formed in a substantially cylindrical shape by a metal flat plate or the like, and is arranged between the bottom plate portion 8A in the machine chamber 8 and the lower portion of the engine 11. The exhaust duct 21 has an opening 21A at one end thereof, and the opening 21A opens obliquely upward to the lower side of the engine 11 near the oil pan 15 of the engine 11. Further, the other end side 21B of the exhaust duct 21 covers the respective outlets 10 from the upper side so that the bottom plate portion 8 of the machine room 8 is covered.
The exhaust duct 21 extends along the line A and communicates with the outside through the outlets 10.

Reference numeral 22 denotes an opening 21A of the exhaust duct 21.
Shows an auxiliary fan disposed on the side, and the auxiliary fan 22 is
Cooling air, which is located in the exhaust duct 21 and is driven to rotate by an electric motor (22A, etc.) provided on the bottom plate portion 8A of the machine chamber 8 and flows in the machine chamber 8 in the direction of arrow B1 into the exhaust duct 21. While sucking from the opening 21A side, it is discharged from the other end side 21B of the exhaust duct 21 to the outside of the machine room 8 via each outlet 10. Then, the auxiliary fan 22 increases the air volume of the cooling air flowing in the machine room 8,
The oil pan 15 and the like are effectively cooled by cooling air in the directions B1 and B3.

The cooling device for the engine 11 according to the present embodiment has the above-mentioned structure, and its basic operation is not different from that of the prior art.

However, in the present embodiment, the exhaust duct 21 is provided between the bottom plate portion 8A of the machine room 8 and the engine 11, and one end side of the exhaust duct 21 is located near the oil pan 15 and below the engine 11. The opening portion 21A is opened, and the other end side 21B is communicated with each outlet 10 of the machine room 8,
Since the auxiliary fan 22 that increases the amount of cooling air is provided in the exhaust duct 21, the following operational effects can be obtained.

That is, the cooling air sucked by the cooling fan 12 from the respective inlets 9 into the machine room 8 is circulated to the lower side of the engine 11 by the auxiliary fan 22 in the direction of arrow B1 and the like, while the exhaust duct 21 Since it is sucked in, the cooling air that flows in the machine room 8 in the directions of the arrows B1, B2, B3, etc. can be sucked into the exhaust duct 21 with a high air volume, and this can be sucked from each outlet 10 to the outside. Can be efficiently discharged. As a result, new cooling air is supplied from each inflow port 9 in the direction of the arrow A at a higher flow velocity (higher air volume), and the air volume of the cooling air flowing through the machine room 8 can be significantly increased. The cooling efficiency in the chamber 8 can be improved.

In this case, particularly, the cooling air flowing in the machine room 8 in the direction of arrow B1 is sucked toward the opening 21A side of the exhaust duct 21 by the auxiliary fan 22, so that the cooling air flowing in the lower side of the engine 11 is cooled. The amount of wind can be reliably increased, and this cooling wind can efficiently cool the oil pan 15 and the like. As a result, for example, the lubricating oil (engine oil) in the oil pan 15 that becomes hot during the operation of the engine 11 can be cooled particularly efficiently.
It is possible to maintain a good operating condition without overheating even during long-term operation, and to prevent deterioration of engine oil even under high-temperature conditions such as midsummer, thereby improving the durability and life of the engine 11 and the like. It can be reliably extended.

Further, by covering the outlet 10 side of the machine room 8 with the other end side 21B of the exhaust duct 21, etc., the exhaust duct 21 acts as a shield between the engine 11 and the outside. It is possible to reliably suppress the noise of the vehicle from leaking to the outside, and while rectifying the cooling air at the other end side 21B of the auxiliary fan 22 and the exhaust duct 21,
The cooling air can be discharged downward from the machine room 8. As a result, noise (engine noise, etc.) in the machine room 8 that diffuses from the hydraulic excavator to the surroundings can be effectively reduced, and the hydraulic excavator can be used in urban areas and at night, and the hydraulic excavator can be used. The work site and environment can be expanded, and the applications of the hydraulic excavator can be expanded.

Furthermore, since it is not necessary to specially provide an obstacle on the front side (left side in FIG. 1) of the radiator 13 unlike other prior arts, the front side of the radiator 13 can be cleaned and cleaned. Maintenance work can be easily performed, and it is possible to effectively prevent clogging of a filter or the like.

Next, FIG. 2 shows a second embodiment of the present invention. The feature of this embodiment is that it is formed on the side opposite to the cooling fan 12 with the engine 11 in between, for example, as a cylindrical body made of a metal plate or the like. The formed exhaust duct 31 is provided, the lower end side 31A of the exhaust duct 31 is formed to have a large diameter, and the auxiliary fan 32 is provided inside, and the upper end side 31B thereof is substantially parallel to the exhaust pipe 17 and the machine chamber 8 The configuration is such that the top plate portion 8C is opened to the outside.

Thus, in this embodiment having the above-described structure, it is possible to obtain substantially the same effects as the first embodiment. However, particularly in this embodiment, the lower end 31A of the exhaust duct 31 is the engine. 11, the upper end side 31B thereof is opened upward to the outside of the machine room 8. Therefore, the cooling air flowing in the direction B3 shown by the arrow toward the rear portion 11C of the engine 11 is exhausted by the auxiliary fan 32. The hydraulic pump 1 driven by the engine 11 and heated to a high temperature, while being able to suck into the air and effectively increase the air volume of the cooling air.
6 and the exhaust pipe 17 serving as a passage for high-temperature exhaust gas can be cooled particularly efficiently, and the engine 11 can be operated even under adverse conditions.
The whole can be cooled effectively.

Further, since the upper end side 31B of the exhaust duct 31 is opened upward from the top plate portion 8C of the machine room 8, the convection phenomenon of air generated in the machine room 8 and the like can be utilized.
The air in the machine room 8 can be effectively discharged upward, which also can generate the flow of the cooling air flowing upward in the machine room 8 and the noise in the machine room 8 to the exhaust duct 31. It can be discharged upward from the upper end side 31B, and it is possible to suppress noise from becoming loud near the hydraulic excavator.

Next, FIG. 3 shows a third embodiment of the present invention. The feature of the third embodiment is that the chimney portion of the exhaust pipe is surrounded from the outside by the upper end side of the exhaust duct provided in the machine room and the exhaust duct is provided. The upper end side of this is opened upward from the machine room together with the chimney portion of the exhaust pipe.

In the figure, reference numeral 41 designates an exhaust duct. The exhaust duct 41 is constructed in substantially the same manner as the exhaust duct 31 described in the second embodiment, but the lower end side 41A becomes a large diameter portion and assists. The fan 42 is accommodated therein, and the upper end side 41B is open upward. However, the exhaust duct 41 is provided with a connecting portion 41C with the exhaust pipe 17 in the middle thereof, and the chimney portion 17A of the exhaust pipe 17 is coaxially arranged in the exhaust duct 41 via this connecting portion 41C. There is. The upper end side 41B of the exhaust duct 41 surrounds the chimney 17A of the exhaust pipe 17 from the outside, and opens upward from the top plate 8C of the machine room 8.

Reference numeral 42 denotes an auxiliary fan provided on the lower end side 41A of the exhaust duct 41, and the auxiliary fan 42 has substantially the same structure as that of the second embodiment. The auxiliary fan 42 generates a cooling air in the machine room 8 in the direction of the arrow B3, and the cooling air is passed through the annular gap 43 between the inner peripheral surface of the exhaust duct 41 and the outer peripheral surface of the exhaust pipe 17. To be discharged to the outside.

Thus, in this embodiment having such a structure, it is possible to obtain substantially the same effects as the second embodiment. However, in this embodiment, the exhaust gas is exhausted at the upper end side 41B of the exhaust duct 41. Since the chimney portion 17A of the pipe 17 is surrounded and both of them are opened at substantially the same position on the top plate portion 8C of the machine room 8, the exhaust gas is discharged from the upper end of the chimney portion 17A of the exhaust pipe 17 during operation of the engine 11. By utilizing the flow of the exhaust gas, an upward flow in the arrow D direction can be generated on the upper end side 41B of the exhaust duct 41, whereby the cooling air from the exhaust duct 41 can be effectively directed in the arrow D direction. Of the cooling air from the exhaust duct 41, the amount of the cooling air flowing in the machine room 8 in the direction of the arrow B3 can be reliably increased, and the cooling efficiency of the engine 11 can be improved. Improve Door can be. Moreover, since the circulation of the cooling air is promoted by the upward flow in the direction of the arrow D due to the exhaust gas,
The load on the auxiliary fan 42 and the like can be reduced, and the power consumption can be reliably reduced.

Further, by surrounding the chimney portion 17A of the exhaust pipe 17 from the surroundings by the upper end side 41B of the exhaust duct 41, the exhaust gas discharged from the exhaust pipe 17 is surrounded, and the annular cooling air from the exhaust duct 41 is surrounded. The exhaust gas can be shielded from the surroundings by the annular cooling air, and the cooling air can act on the exhaust gas like an air curtain. As a result, it is possible to effectively suppress horizontal propagation of exhaust noise due to exhaust gas and exhaust gas, and it is possible to reliably prevent noise of the engine 11 from leaking in the vicinity of the hydraulic excavator. In addition, Engine 1
By surrounding the outside of the exhaust pipe 17, which becomes hot during the operation of 1, with the exhaust duct 41, the chimney portion 17 of the exhaust pipe 17 is surrounded.
A and the like can be cooled, and the exhaust pipe 17 can be prevented from overheating.

Next, FIG. 4 shows a fourth embodiment of the present invention. The feature of this embodiment is that the outlets 51, 51, 51, 51 are formed in the side plate portion 8B on the right side of the machine room 8 which is the rear side of the engine 11. Are formed, and the exhaust duct 52 is disposed over each of the outlets 51 on the rear side of the engine 11, and the exhaust duct 52 is formed.
This is because the auxiliary fan 53 is provided inside.

Thus, in this embodiment having the above-described structure, it is possible to obtain substantially the same effects as the first embodiment. However, particularly in this embodiment, the exhaust duct 52 and the exhaust duct 52 are provided behind the engine 11. Since the auxiliary fan 53 is provided,
Hydraulic pump 16 arranged in the rear part 11C of the engine 11
And the exhaust pipe 17 can be cooled particularly efficiently.

Next, FIG. 5 shows a fifth embodiment of the present invention. The feature of this embodiment is that it extends on the bottom plate portion 8A in the machine room 8 in the left-right direction (the front-back direction of the engine 11). An exhaust duct 61 is provided in the exhaust duct 61, an auxiliary fan 62 is arranged in the exhaust duct 61, and the exhaust duct 61 is formed as a tubular body 61A whose right end side extends upward similarly to the chimney portion 17A of the exhaust pipe 17. Then, the top plate portion 8C of the machine room 8 is penetrated and opened to the outside.

Thus, in the present embodiment thus constructed, the exhaust duct 61 is provided horizontally in the machine chamber 8 in the same manner as in the first embodiment, and is bent halfway to be used in the second embodiment. By opening upwards as in the example,
It is possible to obtain substantially the same operational effects as those of the second embodiment.

That is, the auxiliary fan 62 and the exhaust duct 6
1 can increase the amount of cooling air flowing through the inside of the machine room 8 by discharging the cooling air inside the machine room 8, and by opening the right end side of the exhaust duct 61 upward as a cylinder 61A, Since the noise in the machine room 8 can be emitted upward, the cooling efficiency in the machine room 8 can be improved and the noise can be suppressed from leaking to the vicinity of the hydraulic excavator.

In the fifth embodiment, the right end side of the exhaust duct 61 is opened upward from the top plate portion 8C of the machine room 8 as the cylindrical body 61A, but the present invention is not limited to this. The duct 61 can be effectively opened in any direction as needed.

Further, in each of the above-mentioned embodiments, each auxiliary fan 22, 32, 42, 53, 62 is supposed to rotate at a predetermined rotation speed, but the present invention is not limited to this, and for example, inside the radiator 13. The rotation speed may be changed according to the temperature of the cooling water.

Furthermore, in each of the above-mentioned embodiments, a hydraulic excavator was described as an example of the construction machine, but the present invention is not limited to this, and may be applied to other construction machines such as a hydraulic crane, a wheel loader, and a bulldozer. It can be widely applied.

[0058]

As described above in detail, according to the invention as set forth in claim 1, since the auxiliary fan is provided in the power chamber below the internal combustion engine, the cooling flowing to the lower side of the internal combustion engine is achieved. The amount of wind can be reliably increased by the auxiliary fan, and, for example, the oil pan or the like provided on the lower side of the internal combustion engine can be effectively cooled, and at the same time, the engine oil and the like can be reliably cooled, which allows the internal combustion engine to operate for a long time. It is possible to secure a good operating condition over the entire period.

In this case, according to the invention described in claim 2, the exhaust duct communicating from the lower side of the internal combustion engine to the outlet is provided, and the auxiliary fan is provided in the exhaust duct, so that the power chamber is provided. It is possible to further increase the flow rate of the cooling air flowing through the engine, and more reliably improve the cooling efficiency on the lower side of the internal combustion engine. Further, by covering the outlet with the exhaust duct, the noise of the internal combustion engine or the like in the power chamber can be shielded by the exhaust duct, and the noise leakage to the outside of the power chamber can be effectively reduced.

According to the third aspect of the invention, an exhaust duct that opens upward is provided on the opposite side of the cooling fan with the internal combustion engine interposed therebetween, and the auxiliary fan is disposed in the exhaust duct. As a result, the cooling efficiency can be improved especially on the rear side of the internal combustion engine (the side opposite to the cooling fan), and the volume of the cooling air flowing through the power chamber can be increased. Therefore, for example, a hydraulic pump is provided on the rear side of the internal combustion engine. In this case, the hydraulic pump can be effectively cooled by the cooling air. Further, since the cooling air is discharged upward by the exhaust duct, the noise of the internal combustion engine in the power room can be diffused to the surroundings, and the noise level can be lowered.

In this case, according to the invention described in claim 4, the negative pressure of the exhaust gas is utilized by opening the exhaust duct upward with the upper end side thereof surrounding the exhaust pipe from the outside. The efficiency of discharging the cooling air in the exhaust duct can be improved, and the amount of the cooling air flowing in the power chamber can be further increased. For example, the hydraulic pump can be cooled in the power chamber, and the cooling air surrounds the exhaust gas in an annular shape. By being discharged in this way, the cooling air shields the exhaust noise of the exhaust gas, and the noise level can be further reduced.

[Brief description of the drawings]

FIG. 1 is a vertical sectional view showing a machine room and the like of a hydraulic excavator according to a first embodiment of the present invention.

FIG. 2 is a vertical sectional view similar to FIG. 1, showing a second embodiment of the present invention.

FIG. 3 is a vertical sectional view similar to FIG. 1, showing a third embodiment of the present invention.

FIG. 4 is a partial cross-sectional view of a hydraulic excavator according to a fourth embodiment of the present invention as viewed from above showing a machine room and the like.

FIG. 5 is a horizontal sectional view similar to FIG. 4, showing a fifth embodiment of the present invention.

FIG. 6 is an overall view showing a conventional hydraulic excavator.

FIG. 7 is an enlarged sectional view taken along line VII-VII in FIG.

[Explanation of symbols]

 8 Machine Room (Power Chamber) 9 Inlet 10,51 Outlet 11 Engine (Internal Combustion Engine) 12 Cooling Fan 13 Radiator 21, 31, 41, 52, 61 Exhaust Duct 21A Opening (One End Side) 21B Other End Side 22, 32, 42, 53, 62 Auxiliary fan

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tomishige Yabuki 650 Jinrachi-cho, Tsuchiura-shi, Ibaraki Hitachi Construction Machinery Engineering Co., Ltd. (72) Inventor Ken Iijima 650 Kintate-cho, Tsuchiura-shi, Ibaraki Hitachi Construction Machinery Incorporated company Tsuchiura Plant (72) Inventor Mitsuo Watanabe 1-2 Sasagaoka, Mizuguchi-cho, Koga-gun, Shiga Stock Company Toyosha Shiga Plant (72) Inventor Yasushi Fukushima 2-13, Aize-cho, Hitachi City, Ibaraki Prefecture No. 1 within Hitachi Kiso Co., Ltd.

Claims (4)

[Claims] 1. A power chamber in which an air inlet and an air outlet are formed, an internal combustion engine provided between the inlet and the air outlet in the power chamber, and an inlet of the power chamber. In a cooling device for an internal combustion engine, which is located on a side of the internal combustion engine and includes a cooling fan and a radiator for cooling the internal combustion engine, the cooling device is located below the internal combustion engine in the power chamber, A cooling device for an internal combustion engine, comprising an auxiliary fan for increasing the amount of cooling air flowing through the engine. 2. An exhaust duct, one end of which opens below the internal combustion engine and the other end of which communicates with the outlet, is provided in the power chamber, and the auxiliary fan is provided in the exhaust duct. Item 2. A cooling device for an internal combustion engine according to Item 1. 3. A power chamber in which an air inlet is formed, an internal combustion engine provided in the power chamber, and an internal combustion engine located at the inlet side of the power chamber and provided in the power chamber. In a cooling device for an internal combustion engine, which comprises a cooling fan and a radiator for cooling, the power chamber is located on the opposite side of the cooling fan with the internal combustion engine interposed therebetween, and is directed upward to the outside of the power chamber. A cooling device for an internal combustion engine, comprising: an exhaust duct that is open; and an auxiliary fan that increases the amount of cooling air that flows in the power chamber. 4. The structure according to claim 3, wherein an upper end side of the exhaust duct surrounds an exhaust pipe of the internal combustion engine at least at a tip end side from the outside, and is opened above the power chamber together with the exhaust pipe. Internal combustion engine cooling system.