JP2004036590A - Engine cooling device for construction machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an engine cooling device for a construction machine capable of enhancing a cooling efficiency and reducing a noise caused by a flow of cooling air by making an air speed distribution in a heat exchanger uniform and increasing the amount of air. <P>SOLUTION: The engine cooling device is provided with a first shroud 4a covering a cooling fan 2; a second shroud 4b for introducing cooling air F to the first shroud 4a; and an elastic sealing member 4c for absorbing a relative displacement of the first shroud 4a and the second shroud 4b and sealing a gap between the first shroud 4a and the second shroud 4b. They are arranged such that a distance from a rotation center axis of the cooling fan 2 to a connection part 4b2 (4c2) of the elastic sealing member 4c and the second shroud 4b becomes far than a distance to a connection part 4a2 (4c1) with the first shroud 4a and both connection parts 4b2, 4a2 become approximately the same position regarding the rotation axis direction of the cooling fan 2 to enlarge a space behind a radiator 3d. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an engine cooling device for a construction machine, and more particularly to an engine cooling device for a construction machine provided with a cooling fan for cooling a heat exchanger such as a radiator.
[0002]
[Prior art]
In a construction machine, for example, a hydraulic shovel, a front device such as a boom, an arm, and a bucket and an upper swing body are driven by a hydraulic actuator such as a hydraulic cylinder or a hydraulic motor. Further, these hydraulic actuators are operated by hydraulic oil discharged from a hydraulic pump driven by an engine. The upper revolving unit is provided with a tank for fuel and hydraulic oil, other hydraulic devices such as a hydraulic pump, a motor, a valve, an engine, and the like. In particular, the engine and the hydraulic pump are arranged in an engine room.
[0003]
Usually, in this type of construction machine, in order to cool the engine, a cooling fan driven by the engine is used, and outside air is introduced as cooling air from an intake port provided on one side of a cover that covers the engine room. Note that an axial fan rotated by a driving force from a crankshaft of an engine is often used as a cooling fan.
[0004]
After the cooling air is introduced into the engine compartment, it passes through various heat exchangers such as a radiator or an oil cooler to cool the cooling water and hydraulic oil for cooling the engine, and is provided downstream of the heat exchanger. Guided to the cooling fan by the shroud. The cooling air blown from the cooling fan further cools the engine, the hydraulic pump, and the like, and is then discharged to the outside from an exhaust port provided on the other side of the cover.
[0005]
Here, the various heat exchangers mounted on the construction machine are supported on the engine room floor based on the main frame that forms the skeleton of the upper body structure of the construction machine. For this reason, the vibration and impact accompanying the excavation work or traveling are transmitted to various heat exchangers via the main frame. That is, vibrations different from vibrations in which the engine serves as a vibration source act on the various heat exchangers. On the other hand, the cooling fan is directly connected to the engine rotation shaft, and the cooling fan and the various heat exchangers have completely different swings. Further, the shroud covering the cooling fan has a structure in which one end side is supported by the heat exchanger, so that a relatively large relative displacement occurs between the cooling fan and the shroud. For this reason, the gap (chip clearance) between the downstream portion of the shroud that covers the cooling fan and the outer diameter of the cooling fan must be increased, and the cooling air flows backward from this gap or Leakage and turbulence occurred, resulting in a decrease in air volume, a decrease in fan efficiency, and an increase in noise.
[0006]
To solve such a problem, there is a known technique disclosed in Japanese Utility Model Laid-Open Publication No. Hei 4-6726 (hereinafter referred to as a conventional technique). In this prior art, the shroud is provided with a first shroud that covers the cooling fan and a radiator as a heat exchanger that is provided upstream of the first shroud and introduces cooling air into the first shroud. The first shroud is separated from the second shroud, and the first shroud and the second shroud are connected and sealed by an elastic sealing member (for example, a rubber ring). At this time, since the size of the second shroud is larger than that of the first shroud, the structure is such that the second shroud is bent on the way so as to have substantially the same diameter as the first shroud. By adopting such a structure, the first shroud covering the cooling fan belongs to the vibration system using the engine as the excitation source, similarly to the cooling fan, and the relative displacement between the two shrinks and the chip clearance decreases. Therefore, fan efficiency can be improved and noise can be reduced.
[0007]
[Problems to be solved by the invention]
However, the above-mentioned prior art has the following problems.
In a construction machine, particularly a structure having an upper revolving body such as a hydraulic shovel, it is required that the turning radius of the upper revolving body be smaller for workability at a narrow construction site and safety at the time of turning. . Accordingly, the engine room provided behind the upper-part turning body must also be made as small as possible. On the other hand, from the viewpoint of cooling efficiency, a structure in which a plurality of heat exchangers, a cooling fan, an engine, and a hydraulic pump are respectively arranged in series is generally used, which makes it difficult to reduce the overall length. ing.
[0008]
In order to connect the second shroud having a large diameter and the first shroud having a small diameter, in the case of the above-described conventional technology, the second shroud is connected so that the diameters of the second shroud are equal to each other. The first shroud, the elastic sealing member, and the second shroud are linearly arranged in the limited space between the cooling fan and the radiator in a limited space between the cooling fan and the radiator. Will do. Here, in order to provide an elastic sealing member and a ring for fixing the elastic sealing member on the second shroud side, the bent portion of the second shroud must be located at a position close to a radiator which is a heat exchanger. . For this reason, the cooling air that has passed through the radiator is rapidly reduced at the bent portion of the second shroud, causing a large flow path loss, and further, the difference in the wind speed distribution of the cooling air in the heat exchanger including the radiator becomes large. Accordingly, the amount of cooling air is reduced, and the effect of narrowing the chip clearance cannot be sufficiently exhibited.
[0009]
The present invention has been made in view of the above-mentioned problems in the related art, and has as its object to increase the air volume by making the wind speed distribution of the heat exchanger more uniform and reducing the pressure loss, thereby improving the cooling efficiency. And at the same time, to reduce noise caused by the flow of cooling air.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides at least one heat exchanger including a radiator provided in an engine compartment and cooling a cooling water for cooling the engine, and a cooling air for cooling the heat exchanger. A cooling fan to be induced, a first shroud having one end supported by the engine and covering the cooling fan, and a cooling shroud provided upstream of the first shroud and having one end supported by the heat exchanger. A second shroud for introducing wind into the first shroud; one end connected to the other end of the first shroud and the other end connected to the other end of the second shroud; An elastic sealing member that absorbs relative displacement between the shroud and the second shroud and seals between the first shroud and the second shroud; Distance from the rotation center axis to the other end of the elastic sealing member may be a farther than the distance from the central axis of rotation of the cooling fan to one side of said resilient sealing member.
[0011]
Preferably, a connecting portion between the first shroud and the elastic sealing member and a connecting portion between the second shroud and the elastic sealing member are located at substantially the same position in the rotation axis direction of the cooling fan. Deploy.
[0012]
In the present invention configured as above, the gap caused by the difference between the distance from the rotation center axis of the cooling fan to the first shroud and the distance to the second shroud is covered by the elastic sealing member. Accordingly, it is not necessary to bend the second shroud or the first shroud to match the size (diameter) of the other shroud, and the distance to the throttle portion due to the difference in size between the first shroud and the second shroud. Can be separated from the heat exchanger. For this reason, the flow of the cooling air flowing through the heat exchanger can be made uniform as compared with the conventional case, and the amount of air can be increased by reducing the pressure loss, thereby improving the cooling efficiency and improving the cooling air flow. Noise can be reduced.
[0013]
Further, by providing a ring-shaped fluid guide plate between the elastic sealing member and the heat exchanger, it is possible to eliminate the influence of the backflow of the cooling air and reduce noise.
Further, by providing a slit along the outer periphery of the cooling fan in a space surrounded by the first and second shrouds and the elastic sealing member so as to cover the cooling fan, the influence of the backflow is further eliminated, and noise is reduced. Can be reduced.
[0014]
More preferably, a heat exchanger is arranged in the order of an intercooler, an oil cooler, and a radiator from the upstream side of the flow of the cooling air, and a cooling fan and an engine are further arranged downstream of the heat exchanger to connect the intercooler and the engine. The piping is arranged to pass above the oil cooler header and to the side of the radiator header.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment in which the present invention is applied to a hydraulic excavator as a construction machine will be described with reference to the drawings.
FIGS. 1 to 3 are views for explaining a first embodiment of the present invention. FIG. 1 is a cross-sectional view of an engine room according to the first embodiment, FIG. FIG. 2 is an enlarged view of a main part in FIG. 1.
[0016]
As shown in FIG. 2, the hydraulic excavator includes a traveling body 24 including a pair of left and right crawler tracks, an upper revolving body 26 that is rotatably provided on the traveling body 24, and a cab provided on the left front side of the upper revolving body 26. 25, and a front device provided in front of the upper swing body 26 and including the boom 21, the arm 22, and the bucket 23. Reference numeral 27 denotes a counter weight provided behind the upper swing body 26, and reference numeral 12 denotes a cover of an engine room described later.
[0017]
The engine room in which the engine cooling device is provided is provided at the rear portion of the upper swing body 26, and the engine 1 is supported by a center frame 10 forming a main frame as shown in FIG. Is done. The cooling fan 2 rotates by receiving the driving force of the crankshaft 1a of the engine 1 via the fan belt 1b. In addition, the cooling air F induced by the rotation of the cooling fan 2 flows into the engine room from an intake port 12 a provided on one side of the cover 12. An intercooler 3a and a condenser 3b for an air conditioner are provided in parallel with the flow of the cooling air F at the most upstream side, and the heat exchangers are arranged downstream of the intercooler 3c and the radiator 3d in this order. Each of the heat exchangers 3a to 3d is fixed to a side frame and a side beam-based support member fixed to a center frame 10 (not shown) by welding or the like.
[0018]
The cooling fan 2 is covered with a first shroud 4a, a second shroud 4b, and an elastic sealing member 4c as shown in FIG. One end 4a1 of the first shroud 4a is supported by a support member 7 fixed to the engine 1. The second shroud 4b has one end 4b1 supported by the radiator 3d. The other end 4a2 of the first shroud 4a and the other end 4b2 of the second shroud 4b are connected at one end 4c1 and the other end 4c2, respectively, obtained by bending the elastic sealing member 4c, and are sealed. ing. As shown in FIG. 3, the diameter of the cooling fan 2 from the rotation center axis is larger in the second shroud 4b than in the first shroud 4a. The end 4a2 and the other end 4b2 of the second shroud 4b are substantially at the same position in the direction of the rotation axis of the cooling fan 2, and the elastic sealing member 4c is provided along the radial direction of the cooling fan 2. ing.
[0019]
Reference numeral 8 in FIG. 3 denotes a fan guard provided to cover the cooling fan 2, and 9 denotes a ring for fixing the elastic sealing member 4c. 1, reference numeral 13 denotes a battery, 5 denotes a hydraulic pump driven by the engine 1, and 11 denotes a muffler.
[0020]
In the first embodiment configured as described above, the cooling air F induced by the driving of the cooling fan 2 passes through each of the heat exchangers 3a to 3d and is supported by the radiator 3d provided at the most downstream side. The gas flows through the second shroud 4b, the elastic sealing member 4c, and the first shroud 4a supported on the engine 1 side, and is guided to the cooling fan 2. The cooling air F that has passed through the cooling fan 2 cools the engine 1 and the hydraulic pump 5, and is discharged outside through the cover 12 and an exhaust port 12 b provided in a lower part of the engine room. Here, as described above, the connection between the one end 4c1 of the sealing member 4c and the first shroud 4a and the connection between the other end 4c2 and the second shroud 4b are in the rotational axis direction of the cooling fan 2. Are substantially at the same position, the length of the sealing member 4c in the rotation axis direction of the cooling fan 2 is only the engagement portion required for connection with each of the shrouds 4a and 4b, and is extremely shorter than that of the above-described prior art. It has become something. In the present embodiment, the second shroud 4b can be directly extended from the radiator 3d side to the engine side as much as the sealing member 4c is shortened in the rotation axis direction of the cooling fan 2. That is, it is not necessary to bend the second shroud 4b in accordance with the diameter of the first shroud 4a.
[0021]
Therefore, the second shroud 4b can be extended as it is to the portion where the second shroud 4b and the fan 2 overlap, and as a result, the space behind the radiator 3d can be increased as compared with the conventional structure. . By increasing the space behind the radiator 3d in this manner, the flow of the cooling air F flowing toward the first shroud 4a and the cooling fan 2 can be gently deflected, and the loss of the flow can be reduced. Furthermore, the wind speed distribution of the cooling air F flowing through the radiator 3d is also reduced, so that even with the same number of rotations of the fan, the air volume can be induced more, and the cooling performance of the cooling device can be improved. Conversely, the number of fan rotations can be reduced by the amount of air that has been increased, and this is also effective from the viewpoint of reducing fan noise.
[0022]
Further, a first shroud 4a covering the cooling fan 2 is supported by a support member 7 fixed to the engine 1 side, and belongs to a vibration system using the engine as a vibration source similarly to the cooling fan 2; , The tip clearance 2a can be reduced, so that fan efficiency can be improved and noise can be reduced.
[0023]
Next, a second embodiment of the present invention will be described with reference to FIGS. FIG. 4 is a cross-sectional view of the engine room according to the second embodiment, and FIG. 5 is an enlarged cross-sectional view taken along line BB of FIG.
[0024]
The engine cooling device according to the second embodiment differs from the above-described first embodiment in the following points, and has the same configuration as the others. That is, as shown in FIG. 4, a portion 4 e extending from the upstream side (radiator 3 d side) of the first shroud 4 a ′ is a ring-shaped guide plate, and a slit 4 d is provided in this portion so as to surround the cooling fan 2. ing. As shown in FIG. 5, a plurality of slits 4d are provided along the outer shape of the cooling fan 2.
[0025]
In the second embodiment configured as described above, as shown in FIG. 4, the backflow F ′ flowing out of the blade tip on the inlet side of the cooling fan 2 is circulated at the same location by the slit 4d and the guide plate 4e. . As described above, since the main flow F flowing into the cooling fan 2 can be separated, the influence of the backflow F ′ can be eliminated, and as a result, noise can be reduced.
[0026]
FIG. 6 is a diagram showing a cross-sectional view of an engine room in a third embodiment according to the present invention. In the above-described second embodiment, the guide plate 4e and the slit 4e are provided in the extension of the first shroud 4a '. In the third embodiment, however, the second shroud 4b' on the side of the cooling fan 2 is provided. A part is extended to form a ring-shaped guide plate 4e ', and a slit 4d' is provided on the outer peripheral portion of the guide plate 4e 'as shown in FIG. Other configurations are the same as those of the second embodiment. FIG. 7 is an enlarged view of a cross section taken along line CC in FIG.
[0027]
Also in the third embodiment, similarly to the above-described second embodiment, the backflow F ′ flowing out of the blade tip at the inlet of the cooling fan 2 flows into the cooling fan 2 by the guide plate 4d ′ and the ring 4e ′. It can be separated from the main flow F, so that the influence of the backflow F ′ can be eliminated and noise can be reduced.
[0028]
Note that a new ring-shaped guide plate may be added without changing the shape of the existing first shroud 4a or second shroud 4b.
[0029]
Next, a fourth embodiment of the engine cooling device according to the present invention will be described with reference to FIGS. 8 is a plan view of the arrangement of the heat exchanger of the hydraulic excavator as viewed from above, FIG. 9 is a side view of FIG. 8 viewed from the side, and FIG. 10 is a sectional view taken along the line EE in FIG.
[0030]
As shown in FIG. 8, the heat exchanger in this embodiment is arranged in the order of the intercooler 3a, the oil cooler 3c, and the radiator 3d from the upstream side (the left side in FIG. 8) of the flow of the cooling air F, and (In the vertical direction), the core portions of the heat exchangers 3a, 3b, 3d are arranged so as to overlap. As shown in FIG. 9, the intercooler 3a is disposed slightly above the core portions of the oil cooler 3c and the radiator 3d, and an air conditioning condenser 3b is disposed below the intercooler 3a. The cores of the radiators 3d are arranged so as to overlap. On the other hand, the pipes 13 connected to the headers 3a 'and 3a' of the intercooler 3a are disposed above the header 3c 'of the oil cooler 3c and on both sides of the header 3d' of the radiator 3d as shown in FIG. are doing. The cooling air F flows in from the left side in FIGS. 8 and 9 and is guided to the cooling fan 2 (not shown) after passing through the radiator 3d.
[0031]
In the fourth embodiment configured as described above, since the respective cores of the oil cooler 3c and the radiator 3d are arranged so as to overlap when viewed from the front, the four corners, that is, above (or below) the header 3c 'of the oil cooler. In addition, a pipe 13 for the intercooler 3a can be provided in a space beside the header 3d 'of the radiator 3d. With this arrangement, a larger intercooler 3a can be mounted in a limited space in the engine compartment, and as a result, the cooling capacity of the intercooler 3a can be increased.
[0032]
Further, by disposing the oil cooler 3c and the core portion of the radiator 3d so as to overlap, the flow of the cooling air F is not obstructed by the header 3c 'of each oil cooler 3c, and the cooling efficiency of the radiator 3d is particularly improved. I do.
[0033]
【The invention's effect】
As described above, according to the present invention, the gap caused by the difference between the distance from the rotation center axis of the cooling fan to the first shroud and the distance to the second shroud is covered by the elastic sealing member. It is not necessary to bend the first shroud or the first shroud to the size (diameter) of the other party, and the distance from the heat exchanger to the throttle portion due to the difference in size between the first shroud and the second shroud is eliminated. Can be pulled apart. As a result, the flow of the cooling air flowing through the heat exchanger can be made uniform as compared with the conventional case, and the amount of air can be increased by reducing the pressure loss, thereby improving the cooling efficiency and improving the cooling air flow. Noise can be reduced.
[0034]
Further, by providing a ring-shaped fluid guide plate between the elastic sealing member and the heat exchanger, the influence of the backflow can be eliminated and noise can be reduced.
[0035]
Further, by providing a slit along the outer periphery of the cooling fan in a space surrounded by the first and second shrouds and the elastic sealing member so as to cover the cooling fan, the influence of the backflow can be further eliminated. And noise can be reduced.
[0036]
Further, since the cores of the oil cooler and the radiator are arranged so as to overlap when viewed from the front, the four corners, that is, the space above (or below) the header of the oil cooler and on the side of the header of the radiator, are used for the intercooler. Can be mounted, so that a larger intercooler can be mounted in a limited space in the engine room, and as a result, the cooling capacity of the intercooler can be increased.
[Brief description of the drawings]
FIG. 1 is a side sectional view showing a detailed structure of an engine room provided with an engine cooling device according to a first embodiment of the present invention.
FIG. 2 is a perspective view showing an overall external structure of a hydraulic shovel to which the engine cooling device shown in FIG. 1 is applied.
FIG. 3 is an enlarged view of a portion A in FIG.
FIG. 4 is an enlarged view of a main part of an engine cooling device according to a second embodiment of the present invention.
FIG. 5 is a view as seen from an arrow B in FIG. 4;
FIG. 6 is an enlarged view of a main part of an engine cooling device according to a third embodiment of the present invention.
FIG. 7 is a view as viewed from an arrow C in FIG. 6;
FIG. 8 is a plan view of an engine cooling device according to a fourth embodiment of the present invention.
FIG. 9 is a side view of FIG. 8 viewed from the side.
FIG. 10 is a front view of FIG. 8 as viewed from the upstream side of the cooling air.
[Explanation of symbols]
1 engine 2 cooling fan 3a intercooler (heat exchanger)
3b Condenser (heat exchanger)
3c Oil cooler (heat exchanger)
3d radiator (heat exchanger)
3a 'Header of intercooler 3c' Header of oil cooler 3d 'Header of radiator 4a First shroud 4b Second shroud 4c Elastic sealing member 4d Slit 4e Ring 9 Ring 13 Intercooler piping

Claims (5)

At least one heat exchanger provided in the engine compartment and including a radiator for cooling engine cooling water, a cooling fan for inducing cooling air for cooling the heat exchanger, and one end supported by the engine A first shroud that covers the cooling fan; and a first shroud that is provided on the upstream side of the first shroud and extends in a direction of a rotation center axis of the cooling fan, and one end is supported by the heat exchanger. A second shroud for introducing the cooling air into the first shroud, one end of which is connected to the other end of the first shroud and the other end of which is connected to the other end of the second shroud; An elastic sealing member that absorbs a relative displacement between the first shroud and the second shroud and seals between the first shroud and the second shroud;
A construction machine, wherein the distance from the rotation center axis of the cooling fan to the other end of the elastic sealing member is longer than the distance from the rotation center axis of the cooling fan to one end of the elastic sealing member. Engine cooling device. The connecting portion between the first shroud and the elastic sealing member and the connecting portion between the second shroud and the elastic sealing member are arranged at substantially the same position in the rotation axis direction of the cooling fan. The engine cooling device for a construction machine according to claim 1, wherein: The engine cooling device for a construction machine according to claim 1, wherein a ring-shaped fluid guide plate is provided between the elastic sealing member and the heat exchanger. The slit is provided along the outer periphery of the cooling fan in a space surrounded by the first and second shrouds and the elastic sealing member so as to cover the cooling fan. An engine cooling device for a construction machine according to the above. A heat exchanger is arranged in the order of an intercooler, an oil cooler, and a radiator from the upstream side of the flow of the cooling air, and further, the cooling fan and the engine are arranged further downstream thereof, and the intercooler and the engine are connected. The engine cooling device for a construction machine according to any one of claims 1 to 4, wherein the air pipe is disposed so as to pass above the header of the oil cooler and a side of the header of the radiator.

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