JP2003003849A - Engine cooling device for civil engineering/construction machinery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an engine cooling device for civil engineering/construction machinery, capable of improving the cooling performance for an intermediate heat exchanger and a lower-stream-side heat exchanger, with no increase in the noise of a cooling fan noise. SOLUTION: The upper region of a heat exchanger 9 of an upper cover 13d of an engine compartment 4 as well as the region on the side of side cover 13b, closer to a sucking side, and the upper and side regions of the side cover 13b on the sucking side, are respectively provided with sucking ports 16a, 16b, 16c, and 16d which take in a cooling wind P from outside and then guide it to a cooling fan 11. The sucking ports 16a and 16b are provided at such positions as directly introduce the outside air to a radiator 9c not through an inter cooler 9a and an oil cooler 9b but through the gap of dimension d1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine cooling device for civil engineering / construction machinery such as a hydraulic excavator, and more particularly to civil engineering for cooling a plurality of heat exchangers arranged in an engine compartment with cooling air generated by a cooling fan. The present invention relates to an engine cooling device for a construction machine.

[0002]

2. Description of the Related Art As a conventional technique relating to an engine cooling device for civil engineering and construction machinery, for example, Japanese Patent Laid-Open No. 10-103065 is known.
There is one shown in Japanese Patent Publication.

In this prior art, a cooling fan for generating cooling air in an engine room of civil engineering and construction machinery, that is, an engine room, and a plurality of inlets for introducing outside air for cooling air, that is, a cooling air intake, are provided. , An upstream heat exchanger or an intercooler, a downstream heat exchanger or a radiator, and an intermediate heat exchanger or an oil cooler, which are provided upstream, downstream, or in the middle of the cooling air flow direction, respectively. The cooling air generated by driving the cooling fan and introducing the outside air from the inlet passes through the upstream heat exchanger, the intermediate heat exchanger, and the downstream heat exchanger to cool each, and the downstream It is throttled by a shroud provided further downstream of the side heat exchanger and introduced into the cooling fan.
The cooling air blown from the cooling fan further cools the engine, the hydraulic pump, and the like, and then is discharged from the exhaust port to the outside of the engine room.

[0004]

In the above-mentioned conventional technique, the upstream heat exchanger, the intermediate heat exchanger, and the downstream heat exchanger are arranged in this order in series in the cooling air flow direction. , Most of the area of the intermediate heat exchanger is supplied with the cooling air that has cooled and heated the upstream heat exchanger, and the downstream heat exchanger cools the upstream heat exchanger and the intermediate heat exchanger. Then, as a result of introducing the heated cooling air, cooling of the intermediate heat exchanger and the downstream heat exchanger becomes insufficient.

Here, as one means for improving the cooling performance, there is also a method of increasing the cooling air volume by increasing the rotation speed of the cooling fan or by increasing the diameter of the cooling fan. However, in reality, this method may cause a situation in which the noise of the cooling fan increases.

The present invention has been made in view of the above-mentioned actual situation in the prior art, and its object is to improve the cooling performance of the intermediate heat exchanger and the downstream heat exchanger without increasing noise of the cooling fan. It is to provide an engine cooling device for civil engineering / construction machinery that can be improved.

[0007]

In order to achieve this object, the invention according to claim 1 of the present invention is a cooling fan for generating cooling air in an engine room of civil engineering and construction machinery, and the cooling in the engine room. A plurality of inlets for introducing outside air for wind, upstream side, downstream side along the flow direction of the cooling air, and upstream side heat exchangers respectively provided in the middle, downstream side heat exchangers, and intermediate In an engine cooling device for civil engineering / construction machinery including a heat exchanger, at least one of the plurality of inlets allows outside air to flow outside without passing through the upstream heat exchanger and the intermediate heat exchanger. It is arranged such that it can be introduced into the side heat exchanger.

In the invention according to claim 1 of the present invention thus constructed, when the cooling fan is driven, the outside air introduced through at least one inlet passes through the upstream heat exchanger and the intermediate heat exchanger. Without direct introduction to the downstream heat exchanger. As a result, the downstream heat exchanger can be cooled by the fresh, low-temperature cooling air that has not been heated in the upstream heat exchanger or the intermediate heat exchanger, and therefore the cooling performance of the downstream heat exchanger is improved. Can be made.

The invention according to claim 2 of the present invention is the invention according to claim 1, wherein the size of the gap between the intermediate heat exchanger and the downstream heat exchanger is set to the upstream heat exchanger. It is characterized in that it is made larger than the gap between the intermediate heat exchanger and the intermediate heat exchanger.

In the invention according to claim 2 having such a structure, the outside air introduced from the at least one inlet is passed through a relatively wide gap between the intermediate heat exchanger and the downstream heat exchanger. It can be smoothly and easily introduced into the downstream heat exchanger. Thereby, the cooling performance of the downstream heat exchanger can be reliably improved.

The invention according to claim 3 of the present invention is the invention according to claim 1 or 2, wherein the size of the gap between the intermediate heat exchanger and the downstream heat exchanger is the downstream heat exchanger. The feature is that it is 1/15 times or more of the height dimension of the exchanger.

In the invention according to claim 3 configured as above, the intermediate heat exchanger and the downstream heat exchanger are formed in a shape corresponding to the dimension in the height direction corresponding to the heat exchange area of the downstream heat exchanger. The size can be ensured so that the gap size does not become too small. Thereby, at least one of the above
The outside air introduced through the one inlet can be introduced into the downstream heat exchanger more smoothly and easily through the relatively wide gap between the intermediate heat exchanger and the downstream heat exchanger. As a result, the cooling performance of the downstream heat exchanger can be more reliably improved.

In order to achieve this object, the invention according to claim 4 of the present invention is to introduce a cooling fan for generating cooling air into an engine room of civil engineering and construction machinery, and to introduce outside air for the cooling air into the engine room. A plurality of inlets, and an upstream heat exchanger, a downstream heat exchanger, and an intermediate heat exchanger that are respectively provided on the upstream side, the downstream side, and the middle thereof along the flow direction of the cooling air. In the engine cooling device for civil engineering / construction machinery, at least one of the plurality of inlets introduces outside air into the intermediate heat exchanger and the downstream heat exchanger without passing through the upstream heat exchanger. It is arranged in a position where it is possible.

In the invention according to claim 4 of the present invention thus constructed, when the cooling fan is driven, the outside air introduced from at least one inlet is directly intermediated without passing through the upstream heat exchanger. It is introduced into the heat exchanger and the downstream heat exchanger. As a result, the intermediate heat exchanger and the downstream heat exchanger can be cooled by the fresh and low-temperature cooling air that has not been heated in the upstream heat exchanger, and thus the intermediate heat exchanger and the downstream heat exchanger can be cooled. The cooling performance of can be improved.

According to a fifth aspect of the present invention, in the invention according to the fourth aspect, the size of the gap between the upstream heat exchanger and the intermediate heat exchanger is set to the intermediate heat exchanger. It is characterized in that it is made larger than the size of the gap with the downstream side heat exchanger.

In the invention according to claim 5 having such a configuration, the outside air introduced through the at least one inlet is passed through a relatively wide gap between the upstream heat exchanger and the intermediate heat exchanger. It can be smoothly and easily introduced into the intermediate heat exchanger and the downstream heat exchanger. Thereby, the cooling performance of the intermediate heat exchanger and the downstream heat exchanger can be reliably improved.

The invention according to claim 6 of the present invention is the invention according to claim 4 or 5, wherein the size of the gap between the upstream heat exchanger and the intermediate heat exchanger is set to the intermediate heat exchange. The feature is that it is set to 1/15 times or more of the height direction dimension of the container.

In the invention according to claim 6 having such a structure, the gap between the upstream heat exchanger and the intermediate heat exchanger is formed in a shape corresponding to the dimension in the height direction corresponding to the heat exchange area of the intermediate heat exchanger. Its size can be ensured so that it does not become too small. Thereby, the outside air introduced from at least one of the above-mentioned inlets can be more smoothly and easily passed through the relatively wide gap between the upstream heat exchanger and the intermediate heat exchanger. It can be introduced into a heat exchanger. As a result, the cooling performance of the intermediate heat exchanger and the downstream heat exchanger can be more reliably improved.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of an engine cooling device for civil engineering and construction machinery according to the present invention will be described below with reference to the drawings.

2, FIG. 3, FIG. 1, and FIG. 4 are explanatory views of a first embodiment of an engine cooling device for civil engineering and construction machinery corresponding to the inventions according to claims 1, 2 and 3 of the present invention. And
FIG. 2 is a perspective view showing an overall external structure of a hydraulic excavator that is an example of the civil engineering / construction machine to which the first embodiment is applied, and FIG. 3 is an engine room provided in the hydraulic excavator shown in FIG. 1 is an enlarged perspective view showing the external structure of FIG.
[Fig. 4] is a side sectional view taken along the line I-I in Fig. 3 showing the configuration of the engine cooling device for the civil engineering and construction machine according to the first embodiment, and Fig. 4 is an enlarged view of portion A in Fig. 1.

The hydraulic excavator shown in FIG. 2 has a lower traveling body 1 provided with endless track crawler tracks 1a on the left and right, and this lower traveling body 1
The upper revolving superstructure 2 is provided so as to be rotatable upward, a driver's cab 3 provided on the front left side of the upper revolving superstructure 2, and an engine compartment 4 horizontally disposed on the upper revolving superstructure 2. Further, a counterweight 5 provided at a rear portion of the upper swing body 2 and a front 6 which is an excavating work machine provided at a front portion of the upper swing body 2 and including a boom 6a, an arm 6b, and a bucket 6c are provided.

The above-mentioned crawler track 1a is driven by a left / right traveling hydraulic motor 1b, and the upper swing body 2 is provided with a driver's cab 3, an engine compartment 4, a counterweight 5, an articulated front 6 and the like. The boom 6a, the arm 6b, and the bucket 6c are swung with respect to the undercarriage 1 by a turning hydraulic motor (not shown) provided at the center, and the boom cylinder 7a, the arm cylinder 7b, and the bucket cylinder 7c respectively provided on them. Operate.

The hydraulic cylinder 7 described above in FIG.
The hydraulic actuators a, 7b, 7c, the turning hydraulic motor, the traveling hydraulic motor 1b, etc. are discharged from the hydraulic pump 33 driven by the engine 8 shown in FIG. It is driven by the pressure oil whose flow rate and direction are controlled by the control valve device according to the operation from the operation lever operated by the operator inside.

As shown in FIG. 1, a heat exchanger 9, a shroud 10 provided on the downstream side of the heat exchanger 9, and an air flow for cooling the heat exchanger 9 are provided in the engine compartment 4 described above. A cooling fan 11 for generating the cooling air P and a partitioning member 12 for sealing, which are provided on the outer peripheral portion including the upper portion and the lower portion of the heat exchanger 9, are provided. The heat exchanger 9 is arranged upstream of the cooling fan 11, and specifically, for example, an upstream heat exchanger or an intercooler 9a provided upstream along the flow direction of the cooling air P, and provided downstream. The downstream heat exchanger or radiator 9c is provided, and the intermediate heat exchanger or oil cooler 9c provided in the middle is included. The intercooler 9a pre-cools the compressed combustion intake air supplied to the cylinder head of the engine 8, and the oil cooler 9b is adjacent to the downstream side of the intercooler 9a and is a pressure oil for driving the above-mentioned hydraulic actuators 7a to 7c. That is, the working oil is cooled, and the radiator 9c is located further downstream of the oil cooler 9b and on the most downstream side in the flow direction of the cooling air P to cool the cooling water of the engine 8.

As shown in FIG. 1, the intercooler 9
Each of a, the oil cooler 9b, and the radiator 9c is formed by holding a pipe through which a liquid to be cooled flows inside a guide formed by standing a substantially frame body or two substantially flat plates on both sides. The intercooler 9a includes a pipe 9aA through which combustion air flows and a frame 9a holding the pipe 9aA.
The oil cooler 9b is provided with a pipe 9 through which hydraulic oil is flowed.
The radiator 9c is provided with a pipe 9cA through which engine cooling water flows and a frame 9cB that holds the same. The intercooler frame body 9aB and the oil cooler frame body 9bB are arranged and fixed so as to be in close contact with each other in the flow direction of the cooling air P with almost no clearance, but the oil cooler frame body 9bB and the radiator frame body 9cA are Is arranged so that there is a clearance of dimension d1 in the flow direction of d. This d1 is secured to have a size of 1/15 or more of the vertical dimension H1 of the radiator frame 9cA. Further, the size of the intercooler 9a arranged on the most upstream side of the cooling air P depends on the required heat exchange capacity, that is, the cooling performance, similarly to the engine cooling device of a normal hydraulic excavator of this type. 9b and radiator 9
It is smaller than c, and especially the vertical dimension is smaller. If necessary, the heat exchanger 9 may include a condenser as an upstream heat exchanger indicated by a chain double-dashed line 9d in FIG. 1, and is used for an air conditioner provided in the cab 3.

The outer wall of the engine compartment 4 described above is formed by an engine cover 13, and the engine cover 13, the engine 8, the cooling fan 11, the heat exchanger 9, the hydraulic pump 33, the muffler 34 and other equipment. Is covered. The engine cover 13 is the lower cover 1
3a and the left side of the cab 3, that is, the suction side lateral cover 1
3b, the right side or discharge side lateral cover 13c, the upper cover 13d, the front cover 13e, and the rear cover 13f. One end of the upper cover 13d is attached to the discharge side lateral cover 13c by a hinge 14 so as to be openable and closable, and a locking tool 15 for locking the opening and closing side of the upper cover 13d to the suction side lateral cover 13b is provided. ing. Then, the cooling air P is introduced from the outside to the upper region of the heat exchanger 9 of the upper cover 13d and the region on the suction side lateral cover 13b side thereof, and further to the upper region and the side region of the suction side lateral cover 13b, respectively. Inlet ports for introducing into the fan 11, that is, suction ports 16a, 16b, 16c, 16d are provided respectively, and the suction port 16a and the suction port 16b do not allow outside air to pass through the intercooler 9a and the oil cooler 9b, and the above-mentioned dimension d1. Radiator 9 through the gap
It is arranged at a position where it can be directly introduced into c. Further, in the discharge side lateral cover 13c side region of the upper cover 13d, the discharge side lateral cover 13c, and the hydraulic pump 33 side region of the lower cover 13a, the discharge port 17 for discharging the cooling air P blown from the cooling fan 11 to the outside. , 18, 19 are provided respectively. Note that reference numeral 12 in FIG. 1 denotes a partition member that seals between the heat exchanger 9 and the upper cover 13d, the lower cover 13a, the front cover 13e, and the rear cover 13f.

Further, the above-mentioned engine 8 is provided in the lower part of the upper revolving superstructure 2 and is a frame 20 forming a base lower structure thereof.
A pulley 22 is installed on the crankshaft 8a via a vibration damping device 21, and an auxiliary rotary shaft 23 is shared with the shaft of the cooling fan 11 above the crankshaft 8a. 8 is provided so as to face the inside. A water pump 24 that circulates engine cooling water is connected to a radiator 9c at an end portion of the auxiliary rotary shaft 23 inside the engine 8 through a pipe (not shown). A hydraulic pump 33 is provided on the discharge side lateral cover 13c side of the engine 8 and is connected to the engine 8 through a coupling mechanism (not shown), so-called coupling, and is driven by its driving force, but is fixed to the upper portion of the engine 8. The muffler cover 36 prevents oil from scattering from the hydraulic pump 33 to the engine 8 side. Exhaust gas from the engine 8 is silenced by a muffler 34 and then exhausted through an exhaust gas pipe, that is, a tail pipe 35, to the engine compartment 4
Is released to the outside of. The heat exchanger 9 in the engine compartment 4
A battery 37 for supplying the starting current of the engine 8 is arranged on the upstream side.

The shroud 10 described above, as shown in FIG. 4, has a substantially box-shaped front portion fixed to the downstream side of the heat exchanger 9, that is, a box shroud or shroud cover 10a, and the front portion 10a. It is a so-called separated type or two-piece type shroud formed by a rear portion of the substantially bellmouth shape, that is, the fan ring 10b, which is located on the further downstream side and is arranged on the radially outer side of the cooling fan 11, and is generated by the cooling fan 11. The cooling air P is introduced to the suction side. The front part 10a is fixed to the downstream side of the cooling air P on the right side when viewed from the operator's cab 3 of the radiator 9c,
The rear portion 10b is fixed to a bracket provided on the engine 8, that is, the stay 41, and a ring guard portion 10b1 for ensuring safety is provided on the downstream side of the cooling air P. Mounting bracket portions 10b1A are provided at a plurality of circumferential positions of the ring guard portion 10b1 so as to project in the radial direction, and each mounting bracket portion 10b1A is provided with a through hole 45. On the other hand, from the engine 8, a number of brackets 41 are arranged at positions and numbers corresponding to the ring guard mounting bracket portion 10b1A, and mounting bolts 42a passed through through holes 41a formed near the tip of each bracket 41 are further attached to the ring guard. The shroud rear portion 10b is detachably attached to the bracket 41 by fastening the rear mounting nut 42b which is passed through the through hole 45 of the bracket portion 10b1A. Stops 10ao and 10bo are provided near the downstream end of the shroud front part 10a and near the upstream end of the rear part 10b, respectively, and are made of an elastic material such as rubber for the stops 10ao and 10bo. After the formed sealing member, that is, the shroud rubber bar or the rubber ring 43 is attached by being hooked, the vicinity of the upstream end of the sealing member 43 is tightened with a band 44 to prevent the sealing member 43 from slipping or coming off. With such a structure, when the cooling fan 11 is operating, the tip clearance c between the shroud rear portion 10b and the blades 11b of the cooling fan 11 is made as small as possible to improve the fan performance, and the vibration system on the heat exchanger 9 side is improved. The front part 1 of the shroud is allowed while allowing relative displacement between the shroud front part 10a and the shroud rear part 10b belonging to the vibration system on the engine 8 side.
A seal is made between 0a and the rear part 10b.

The cooling fan 11 is a so-called axial fan attached to the auxiliary rotary shaft 23 to which the driving force from the engine crankshaft 8a is transmitted as shown in FIG. Fixed boss 11a and a plurality of blades 11b fixed around this boss 11a
And is driven to rotate by the rotation of the auxiliary rotary shaft 23 to generate the cooling air P to the right in FIG. A pulley 25 is fixed to the auxiliary rotary shaft 23 at a position corresponding to the pulley 22 of the engine crankshaft 8a.
Between the belt and the pulley 25, that is, the fan belt 2
6 is passed over.

The operation of the first embodiment thus configured is as follows. When the engine 8 is driven during hydraulic excavator work, the rotation of the crankshaft 8a is transmitted to the auxiliary rotary shaft 23 via the pulley 22, the belt 26, and the pulley 25. As a result, the water pump 24 is driven to circulate the cooling water of the radiator 9c, and
The cooling fan 11 is driven and rotates. Due to the rotation of the cooling fan 11, the air outside the cover 13 is sucked into the suction port 16
The cooling air P is introduced into the engine compartment 4 from a, 16b, 16c, 16d and flows in from the upstream side to cool the intercooler 9a, the oil cooler 9b, and the radiator 9c. In particular, the cooling air P introduced from the suction port 16c and the suction port 16d receives the intercooler 9a and the oil cooler 9
While the radiator 9c is cooled after cooling b (or only the oil cooler 9b), the suction ports 16a, 1
The cooling air P introduced from 6b is directly introduced into the radiator 9c without passing through the intercooler 9a and the oil cooler 9b. At this time, by providing an air guide plate 40 in FIG. 1, it is possible to further smooth the flow of the cooling air P from the suction port 16b. These cooling air P
Is the shroud 10 downstream of the radiator 9c.
This is a so-called suction cooling system in which the cooling is passed through the insides of a and 10b and is narrowed down and introduced to the suction side of the cooling fan 11. After that, the cooling air P blown out from the cooling fan 11 cools the engine 8 and the hydraulic pump 33 on the downstream side of the cooling fan 11, and then the discharge ports 17, 18, 19 are discharged.
Is discharged to the outside of the engine room 4.

According to the first embodiment having such a configuration, the cooling air P introduced from the suction ports 16a and 16b is directly introduced into the radiator 9c without passing through the intercooler 9a and the oil cooler 9b. As a result, the radiator 9c can be cooled by the fresh and low-temperature cooling air P that has not been heated by the intercooler 9a or the oil cooler 9b, and therefore the cooling performance of the radiator 9c can be improved. In addition, when the cooling airflow is directly introduced into the radiator 9c in this manner, the inventors of the present application have studied how much the clearance dimension d1 between the oil cooler 9b and the radiator 9c should be widened to be effective in cooling performance. It has been found that a relatively good cooling performance can be surely obtained if at least 1/15 of the height direction dimension H1 of the radiator 9c which is the downstream side heat exchanger is set. Based on this knowledge, in the first embodiment, the gap dimension d1 between the oil cooler 9b and the radiator 9c is set to 1/15 or more of the height direction dimension H1 of the radiator 9c, and the gap between the intercooler 9a and the oil cooler 9b is set. By making the size larger than the size, the outside air introduced from the suction ports 16a and 16b can be smoothly and easily passed through the relatively wide gap between the oil cooler 9b and the radiator 9c.
c can be introduced. This allows the radiator 9
It is possible to reliably improve the cooling performance of c. As described above, the cooling air P introduced through the suction ports 16a to 16d is used, and the heat exchanger groups 9a to 9 have different cooling loads.
c or 9d can be efficiently cooled.

In the first embodiment, the suction port 1
The cooling air P introduced from 6a and 16b is the intercooler 9
Although it was introduced directly into the radiator 9c without passing through either a or the oil cooler 9b, the invention is not limited to this. For example, as shown in FIG. 5, the upper end of the intercooler 9a projects upward from the upper end of the oil cooler 9b. By arranging in such a manner, the cooling air P introduced from the suction port 16b may be introduced into the radiator 9c via the intercooler 9a, and the cooling performance of the intercooler 9a may also be improved. In this case, the cooling air P introduced from the suction port 16b exchanges heat with the intercooler 9a and rises in temperature from the outside air before flowing into the radiator 9c. However, the cooling heat load is larger than that of the intercooler 9a. Since it has not passed through 9b, the cooling performance of the radiator 9c is not significantly impaired.

FIG. 6 is an explanatory view of a second embodiment of an engine cooling device for civil engineering / construction machinery corresponding to the inventions according to claims 4, 5 and 6 of the present invention. It is a sectional side view which shows the structure of 2nd Embodiment of an apparatus.

In FIG. 6 showing the second embodiment, the gap dimension d between the oil cooler 9b and the radiator 9c shown in FIG.
1 is 1/15 or more of the height dimension H1 of the radiator 9c and is larger than the clearance dimension between the intercooler 9a and the oil cooler 9b.
The clearance dimension d2 between a and the oil cooler 9b is set to be 1/15 or more of the height direction dimension H2 of the oil cooler 9b to be larger than the clearance dimension between the intercooler 9b and the radiator 9c, and the suction port 16a and the suction port 16b are protected from the outside air. It is arranged such that it can be directly introduced into the oil cooler 9b through the gap of the above-mentioned dimension d2 without the intercooler 9a. Other configurations are shown in FIG.
This is equivalent to the first embodiment shown in FIG.

In the second embodiment having such a configuration,
When the air outside the cover 13 is introduced as cooling air P into the engine compartment 4 by the rotation of the cooling fan 11 from the suction ports 16a, 16b, 16c, 16d, the cooling air P introduced from the suction ports 16c and 16d. Half of the cooling air cools the oil cooler 9b after cooling the intercooler 9a, whereas the cooling air P introduced from the suction port 16a and the suction port 16b directly passes through the oil cooler 9b without passing through the intercooler 9a. Will be introduced to. At this time,
By providing the baffle plate indicated by 41 in FIG. 6, it is possible to further smooth the flow of the cooling air P from the suction port 16b.

According to the second embodiment having such a configuration, the cooling air P introduced from the suction ports 16a and 16b directly passes through the oil cooler 9b without passing through the intercooler 9a.
Will be introduced to. As a result, the oil cooler 9b and the radiator 9c can be cooled by the fresh and low-temperature cooling air P that has not been heated by the intercooler 9a.
Therefore, the cooling performance of the oil cooler 9b and the radiator 9c can be improved. Further, based on the above-mentioned knowledge, the intercooler 9a is also used in the second embodiment.
The gap dimension d2 between the oil cooler 9b and the oil cooler 9b.
The outside air introduced from the suction ports 16a, 16b is set to be 1/15 or more of the height direction dimension H2 of b and larger than the clearance dimension between the oil cooler 9b and the radiator 9c.
It can be smoothly and easily introduced into the oil cooler 9b through a relatively wide gap between the intercooler 9a and the oil cooler 9b. As a result, the cooling performance of the oil cooler 9b and the radiator 9c can be reliably improved, and in particular, the cooling performance of the oil cooler 9b can be improved and the temperature of the working oil that is the refrigerant in the pipe can be reduced. As described above, the cooling air P introduced through the suction ports 16a to 16d is used, and the heat exchanger groups 9a to 9 have different cooling loads.
c or 9d can be efficiently cooled.

In the second embodiment, the suction port 1
The cooling air P introduced from 6a and 16b was directly introduced into the oil cooler 9b without passing through the intercooler 9a, but the invention is not limited to this. For example, as shown in FIG. The cooling air P introduced from the suction port 16b is introduced into the oil cooler 9b through the intercooler 9a by arranging the cooler 9b so as to project upward from the upper end portion of the intercooler 9a.
You may make it improve the cooling performance of. In this case as well, the cooling air P introduced from the suction port 16b exchanges heat with the intercooler 9a and rises in temperature from the outside air before flowing into the oil cooler 9b. However, the amount of heat released from the intercooler 9a reaches the oil cooler 9b. Small compared to
The cooling performance of the oil cooler 9b is not significantly impaired.

In the above, the case where the present invention is applied to the engine room of a hydraulic excavator has been described as an example. However, the present invention is not limited to this, and other civil engineering / construction machinery such as cranes, self-propelled crushers, wheel loaders, etc. It may be applied to the engine compartment. It goes without saying that similar effects can be obtained in these cases as well.

[0039]

As described above, according to the inventions according to claims 1 to 3 of the present invention, the outside air introduced from at least one inlet passes through the upstream heat exchanger and the intermediate heat exchanger. Instead of being directly introduced into the downstream heat exchanger, the downstream heat exchanger can be cooled by the fresh and low-temperature cooling air that has not been heated in the upstream heat exchanger or the intermediate heat exchanger. Therefore, the cooling performance of the downstream heat exchanger can be improved.

Further, in particular, according to the invention of claim 2,
Outside air introduced from at least one inlet can be smoothly and easily introduced into the downstream heat exchanger via a relatively wide gap between the intermediate heat exchanger and the downstream heat exchanger,
Thereby, the cooling performance of the downstream heat exchanger can be surely improved.

In particular, according to the invention of claim 3,
By ensuring that the size of the gap between the intermediate heat exchanger and the downstream heat exchanger does not become too small in accordance with the height direction dimension corresponding to the heat exchange area of the downstream heat exchanger The cooling performance of the side heat exchanger can be more reliably improved.

Further, according to the inventions according to claims 4 to 6 of the present invention, the outside air introduced from at least one inlet directly passes through the intermediate heat exchanger and the downstream heat exchanger without passing through the upstream heat exchanger. By being introduced into the heat exchanger, the intermediate heat exchanger and the downstream heat exchanger can be cooled by the fresh and low-temperature cooling air that has not been heated in the upstream heat exchanger, and thus the intermediate heat exchanger and The cooling performance of the downstream heat exchanger can be improved.

Further, in particular, according to the invention of claim 5,
To smoothly and easily introduce the outside air introduced from at least one inlet into the intermediate heat exchanger and the downstream heat exchanger through a relatively wide gap between the upstream heat exchanger and the intermediate heat exchanger. This makes it possible to reliably improve the cooling performance of the intermediate heat exchanger and the downstream heat exchanger.

In particular, according to the invention of claim 6,
The size of the intermediate heat exchanger can be ensured so that the size of the gap between the upstream heat exchanger and the intermediate heat exchanger does not become too small according to the height direction dimension corresponding to the heat exchange area. The cooling performance of the heat exchanger and the downstream heat exchanger can be further improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a detailed structure of an engine room in which a first embodiment of an engine cooling device for civil engineering and construction machinery of the present invention is provided.

FIG. 2 is a perspective view showing an overall external structure of a hydraulic excavator that is an example of a construction machine to which the first embodiment shown in FIG. 1 is applied.

FIG. 3 is an enlarged perspective view showing an external structure of an engine compartment to which the first embodiment shown in FIG. 1 is applied.

FIG. 4 is an enlarged view of part A in FIG.

FIG. 5 is a cross-sectional view showing a detailed structure of an engine compartment in which a modification of the first embodiment shown in FIG. 1 is provided.

FIG. 6 is a cross-sectional view showing a detailed structure of an engine room in which a second embodiment of the engine cooling device for civil engineering and construction machinery of the present invention is provided.

FIG. 7 is a cross-sectional view showing a detailed structure of an engine compartment in which a modification of the second embodiment shown in FIG. 6 is provided.

[Explanation of symbols]

4 engine room 8 engine 9 heat exchanger 9a Intercooler (upstream heat exchanger) 9b Oil cooler (intermediate heat exchanger) 9c radiator (downstream heat exchanger) 11 Cooling fan 16a-d Suction port (inlet) d1 Gap between oil cooler and radiator d2 Gap size between intercooler and oil cooler H1 radiator height direction H2 oil cooler height direction P cooling air

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) F01P 3/18 F01P 3/18 G 5/06 510 510 5/06 510A F02B 29/04 F02B 29/04 K ( 72) Inventor Shigehisa Funabashi 502 Jinrachi-cho, Tsuchiura-shi, Ibaraki Machinery Research Institute, Hiritsu Manufacturing Co., Ltd. ) 2D015 CA02 3D038 AA01 AA05 AB09 AC02 AC11 AC12 AC14 AC26 3G013 DA02 DA19

Claims (6)

[Claims] 1. A cooling fan for generating cooling air in an engine room of a civil engineering / construction machine, a plurality of inlets for introducing outside air for the cooling air into the engine room, and along a flow direction of the cooling air. In the engine cooling device for civil engineering / construction machinery, which includes an upstream side heat exchanger, a downstream side heat exchanger, a downstream side heat exchanger, and an intermediate heat exchanger that are respectively provided in the upstream side, the downstream side, and the middle thereof, the plurality of inlets At least one of them is arranged at a position where outside air can be introduced into the downstream heat exchanger without passing through the upstream heat exchanger and the intermediate heat exchanger. Machine engine cooling system. 2. The gap size between the intermediate heat exchanger and the downstream heat exchanger is larger than the gap size between the upstream heat exchanger and the intermediate heat exchanger. The engine cooling device for civil engineering / construction machinery according to claim 1. 3. The gap size between the intermediate heat exchanger and the downstream heat exchanger is set to be 1/15 times or more the dimension in the height direction of the downstream heat exchanger. Item 1. An engine cooling device for civil engineering and construction machinery according to item 1 or 2. 4. A cooling fan for generating cooling air in an engine room of civil engineering / construction machinery, a plurality of inlets for introducing outside air for the cooling air into the engine room, and along a flow direction of the cooling air. In the engine cooling device for civil engineering / construction machinery, which includes an upstream side heat exchanger, a downstream side heat exchanger, a downstream side heat exchanger, and an intermediate heat exchanger that are respectively provided in the upstream side, the downstream side, and the middle thereof, the plurality of inlets At least one of them is arranged at a position where outside air can be introduced into the intermediate heat exchanger and the downstream heat exchanger without passing through the upstream heat exchanger. Machine engine cooling system. 5. A gap size between the upstream heat exchanger and the intermediate heat exchanger is larger than a gap size between the intermediate heat exchanger and the downstream heat exchanger. The engine cooling device for civil engineering and construction machinery according to claim 4. 6. The gap size between the upstream heat exchanger and the intermediate heat exchanger is set to 1/15 times or more of the height direction dimension of the intermediate heat exchanger. 4. An engine cooling device for civil engineering and construction machinery according to 4 or 5.