JP2009057934A - Cooling fan shroud structure, and cooling unit of construction machine provided therewith - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cooling fan shroud structure and a cooling unit of a construction machine provided therewith, capable of reducing noise in a shroud by smoothing an airflow in overhung parts by a simple structure. <P>SOLUTION: This shroud structure 40 of a cooling fan 21 includes: a case part 41 attached to cover the peripheral parts of the blade members 21a of the cooling fan 21; the overhung parts 42 formed to project horizontally from the case part 41 along the rotational tracks of the blade members 21a; and inner wall parts 43 formed on the inner wall surfaces of the overhung parts 43 positioned near to the end parts of the blade members 21a. The inner wall parts 43 are formed along the direction of the airflow generated by rotatively driving the cooling fan 21. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a shroud structure of a cooling fan mounted on a construction machine or the like and a cooling unit for a construction machine including the shroud structure.

  2. Description of the Related Art Conventionally, a cooling unit that cools a cooling medium in a radiator while circulating the cooling medium between the engine and a radiator has been used as a cooling means for an engine mounted on a construction machine or the like. In such a cooling unit, a radiator is arranged in the air flow generated by the cooling fan, and air is rectified by a fan shroud attached so as to cover the periphery of the cooling fan. By exchanging heat with air, the cooling efficiency of the engine is increased.

For example, Patent Document 1 discloses a cooling device configured to cover an outer peripheral portion of a cooling fan with a shroud formed in a box shape in accordance with the shape of a radiator. In this configuration, the inner wall portion of the shroud, which is close to the end of the blade member (blade) that constitutes the cooling fan, is expanded radially outward to eliminate a portion where the space is locally narrowed in the shroud. The generation of noise due to large pressure fluctuations is reduced.
JP-A-9-118141 (published on May 6, 1997)

However, the configuration of the conventional engine cooling device has the following problems.
In other words, the engine cooling device disclosed in the above publication employs a structure in which a protruding portion (expanded portion) is provided in a part of the shroud. There is a possibility that turbulent flow is generated in the space on the inner peripheral side of the section and noise is likely to be generated.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a cooling fan shroud structure and a cooling unit for a construction machine equipped with the same that can smooth the air flow in the overhanging portion and reduce noise in the shroud with a simple configuration. It is to provide.

  A shroud structure of a cooling fan according to a first aspect of the present invention is a shroud structure of a cooling fan that is attached so as to cover an outer peripheral portion of a cooling fan that generates a flow of air that is blown against a cooling core. And an overhanging portion and an inner wall portion. The case portion is disposed close to the outer peripheral portion of the cooling fan. The projecting portion is a part of the case portion and is formed so as to project to the outer peripheral side in accordance with the rotation track of the cooling fan. The inner wall portion is disposed on the inner peripheral surface side facing the cooling fan in the projecting portion, and is formed along the flow of air that spreads outward in the radial direction generated by the rotation of the cooling fan.

  Here, in order to supply as much airflow as possible to the cooling core such as a radiator, it is formed so as to project to the outer peripheral side along the trajectory where the cooling fan as large as possible takes into account the layout etc. In the shroud structure provided with the overhanging portion, an inner wall portion constituting a surface on the inner peripheral side of the overhanging portion is formed along a flow direction of air generated by the cooling fan. And the flow of the air produced | generated by this cooling fan is formed so that it may spread to radial direction outer side seeing from a rotating shaft.

Here, in the installed state, for example, the overhanging portion may be formed on both the left and right sides of the case portion attached so as to cover the outer peripheral portion of the cooling fan, or only the upper portion or only the left and right side surfaces. It may be formed. The cooling core includes a radiator, an oil cooler, an aftercooler, and the like.
Thereby, since the inner wall part of a shroud structure is formed along the flow of the air produced | generated when a cooling fan rotates, it can prevent that the air flow is obstructed in an overhang | projection part. As a result, the flow of air in the overhanging portion can be made smooth, and the generation of noise in the shroud can be effectively reduced.

The cooling fan shroud structure according to the second invention is the cooling fan shroud structure according to the first invention, and the inner wall portion constitutes the cooling fan in a sectional view along the rotation axis direction of the cooling fan. It is formed along the shape of a plurality of blade members.
Here, as described above, the surface of the inner wall portion formed along the direction in which the air flows is formed along the shape of the end portion of the blade member of the cooling fan disposed close to the end surface.

  As a result, when the cooling fan rotates, the problem of noise generation is more effectively reduced by making the distance between the cooling fan blade member and the inner wall of the shroud structure substantially constant in the overhanging portion. Can do.

A cooling fan shroud structure according to a third aspect of the present invention is the cooling fan shroud structure according to the first or second aspect of the present invention, and the inner wall portion is configured to include a plurality of R portions.
Here, as described above, the surface of the inner wall portion formed along the air flow direction is formed to be a smooth surface including a plurality of R portions.
Thereby, compared with the conventional shroud structure which has the inner wall part containing the some surface which cross | intersects an acute angle, the flow of the air which flows through the overhang | projection part can be made smooth, and generation | occurrence | production of noise can be reduced more effectively.

A cooling fan shroud structure according to a fourth aspect of the present invention is the cooling fan shroud structure according to any one of the first to third aspects of the present invention, wherein the overhanging portion is disposed opposite to the end of the cooling core. Yes.
Here, in a front view, the protruding portion is disposed so as to overlap with an end portion of a cooling core such as a radiator that feeds cooling air.
Thereby, it is possible to arrange a cooling fan having the maximum size with respect to the cooling core and to supply sufficient air. As a result, cooling efficiency in a cooling core such as a radiator can be improved.

A cooling unit for a construction machine according to a fifth aspect includes a cooling fan shroud structure according to any one of the first to fourth aspects, a cooling fan, and an air flow generated by the cooling fan. A cooling core to be disposed.
Accordingly, as described above, a cooling unit capable of reducing the noise by smoothing the air flow in the overhanging portion with a simple configuration can be obtained.

A construction machine cooling unit according to a sixth aspect of the present invention is the construction machine cooling unit according to the fifth aspect of the present invention, and the cooling fan is rotationally driven by an engine mounted on the construction machine.
Here, for example, the cooling fan is driven to rotate by an engine mounted on a construction machine such as a hydraulic excavator.
Thereby, since the rotation of the engine can be used as it is for the rotation drive of the cooling fan, the configuration can be simplified.

A construction machine cooling unit according to a seventh aspect is the construction machine cooling unit according to the fifth aspect, wherein the cooling fan is rotationally driven by a hydraulic drive motor mounted on the construction machine.
Here, for example, the cooling fan is rotationally driven by a hydraulic drive motor mounted on a construction machine such as a hydraulic excavator.

  Thereby, the vibration of the cooling fan transmitted from the engine can be suppressed as compared with the configuration in which the cooling fan is rotationally driven by the engine direct connection. As a result, since the amount of clearance (clearance) between the inner wall portion and the cooling fan in the shroud structure can be reduced, the air flow in the overhanging portion is made smoother and noise generation is reduced while cooling. Efficiency can be improved.

A construction machine cooling unit according to an eighth aspect of the present invention is the construction machine cooling unit according to any one of the fifth to seventh aspects of the present invention, wherein the cooling fan is configured to supply air to the cooling core. It arrange | positions in the flow direction at the downstream of a cooling core.
Here, a cooling fan is arranged on the downstream side of the cooling core in the air flow direction so as to constitute an intake type cooling unit that feeds air while sucking into a cooling core such as a radiator.

  Thereby, even if it is an intake type cooling unit, the flow of air can be made smooth and noise reduction can be achieved.

  According to the shroud structure of the cooling fan according to the present invention, the air flow in the overhanging portion can be smoothed and the noise can be reduced with a simple configuration.

A hydraulic excavator (construction machine) 1 equipped with a shroud structure for a cooling fan according to an embodiment of the present invention will be described as follows with reference to FIGS.
[Configuration of hydraulic excavator 1 as a whole]
As shown in FIG. 1, a hydraulic excavator 1 according to the present embodiment includes a lower traveling body 2, a swivel base 3, a work implement 4, a counterweight 5, an engine room 6, an equipment room 9, and a cab 10. And a cooling unit 20 (see FIG. 3 and the like).

The lower traveling body 2 has the crawler belt P wound around the left and right end portions in the traveling direction to rotate the hydraulic excavator 1 forward and backward, and the swivel base 3 is mounted on the upper surface side in a state in which the swivel base 3 can be turned. Yes.
The swivel base 3 can be swung in any direction on the lower traveling body 2 and has a work machine 4, a counterweight 5, an engine room 6, and a cab 10 mounted on the upper surface.

  The work machine 4 is configured to include a boom 11, an arm 12 attached to the tip of the boom 11, and a bucket 13 attached to the tip of the arm 12. The work machine 4 is a civil engine that excavates earth and sand and gravel while moving the boom 11, the arm 12, the bucket 13 and the like up and down by the hydraulic cylinders 11a, 12a and 13a included in a hydraulic circuit (not shown). Work at the construction site.

The counterweight 5 is made of, for example, scrap iron or concrete in a box formed by assembling steel plates and is hardened. The counterweight 5 is an engine room 6 on the swivel 3 for balancing the vehicle body during mining. It is provided behind.
As shown in FIGS. 2 and 3, the engine room 6 is disposed adjacent to the counterweight 5 and has an upper opening for inspection covered with an engine hood 14 that can be opened and closed with a handle 14a. is doing. The engine room 6 accommodates therein a cooling unit 20 (see FIG. 3) including an engine 6a that is a power source for driving the lower traveling body 2 and the work machine 4, a cooling core 30, and the like.

The equipment room 9 is disposed behind the work machine 4 and houses a fuel tank, a hydraulic oil tank, an operation valve, and the like (not shown).
The cab 10 is a driver's cab in which an operator of the excavator 1 gets on and off, and is disposed on the left front side on the swivel 3 so that the tip of the work machine 4 can be seen. .

As shown in FIG. 4, the cooling unit 20 is disposed in a position adjacent to the engine 6 a in the engine room 6, and cools cooling water, hydraulic oil, and the like flowing through the engine 6 a. The configuration of the cooling unit 20 will be described in detail later.
[Cooling unit 20]
As shown in FIGS. 3 and 4, the cooling unit 20 includes a cooling fan 21 and a cooling core 30.

  As shown in FIG. 4 and the like, the cooling fan 21 is directly connected to the engine 6a, and the blade member 21a (see FIG. 6 and the like) is directly rotated by the engine 6a. Further, the cooling fan 21 has a shroud structure 40 (see FIG. 6 and the like) described later, and efficiently cools while sending a large amount of air to the cooling core 30 while reducing noise. Furthermore, in the present embodiment, when the cooling fan 21 is driven, an air flow is formed in the direction of suction with respect to the cooling fan 21 as indicated by the arrows in FIG. That is, the cooling fan 21 is disposed on the downstream side of the cooling core 30 in the air flow generated by the cooling fan 21. The configuration of the cooling fan 21 will be described in detail later.

The cooling core 30 is a unit that cools the cooling medium by exchanging heat with air, and is configured to include a radiator 31, an oil cooler 32, an after cooler 33, and the like, as shown in FIG.
The radiator 31 reduces the temperature of the cooling water by causing heat exchange between the cooling water flowing through the engine 6 a and the air generated by the cooling fan 21.

The oil cooler 32 exchanges heat between the oil whose temperature has been increased by being supplied from the hydraulic oil tank to the hydraulic circuit and the air generated by the cooling fan 21, whereby each hydraulic cylinder 11 a, 12 a, 13 a. Reduce the temperature of the oil sent to etc.
The aftercooler 33 caused heat exchange between the air that the turbocharger (not shown) of the engine 6a sucked and discharged from the air cleaner 35 and the air generated by the cooling fan 21, and the temperature rose. After cooling the air, the air is sent to an intake manifold (not shown) of the engine 6a.

(Cooling fan 21)
As shown in FIGS. 6 and 7, the cooling fan 21 has six blade members 21 a constituting an axial fan and a shroud structure 40.
As shown in FIG. 8, the blade member 21a is fitted into a circular space including an overhang portion 42 that is a part of the shroud structure 40, and is driven to rotate by the engine 6a. And the flow of the air which spreads from a rotating shaft to a radial direction outer side is produced | generated by rotationally driving the six blade members 21a.

As shown in FIGS. 6 and 7, the shroud structure 40 is attached so as to cover the outer peripheral portion of the blade member 21a of the cooling fan 21, and includes a case portion 41, an overhang portion 42, and an inner wall portion 43 (FIG. 9). (See (b)).
The case part 41 is a box-shaped member having a circular opening formed along the outer peripheral portion of the blade member 21a.

The overhanging portion 42 is a blade member at both left and right end portions of the case portion 41 in order to mount the cooling fan 21 as large as possible under the installation conditions in the space in the engine room 6 with respect to the cooling core 30 including the radiator 31 and the like. It is a substantially arc-shaped portion that is expanded to the left and right along the rotation trajectory 21a.
As shown in FIG. 8, the inner wall portion 43 is an inner wall surface facing the blade member 21 a in the overhang portion 42, and is formed along the direction in which air flows outward in the radial direction generated by the cooling fan 21. ing. Further, as shown in FIG. 8, the inner wall portion 43 is formed along the shape of the tip portion of the blade member 21a in a cross-sectional view at a position close to the blade member 21a. As a result, the air flow in the overhanging portion 42 when the cooling fan 21 is driven can be made smooth, the amount of air supplied to the cooling core 30 can be increased, the cooling efficiency can be improved, and the noise can be reduced. it can.

  Here, as shown in FIGS. 9A and 9C, the left and right end portions of the case portion 41 have straight inner wall surfaces. On the other hand, both left and right ends of the overhanging portion 42 have curved inner wall surfaces 43 including two R portions 43a and 43b, as shown in FIG. 9B. As a result, the inner wall surface 43 along the shape of the tip of the blade member 21a of the cooling fan 21 along the air flow direction described above is provided on the inner wall surface side of the overhanging portion 42 adjacent to the blade member 21a. be able to. As a result, in the shroud structure 40, air can smoothly pass through the inner wall portion 43 that is the inner wall surface side of the overhang portion 42 that is the portion closest to the blade member 21 a of the cooling fan 21. Therefore, it is possible to reduce the noise during the rotation of the cooling fan 21 and improve the cooling efficiency.

[Characteristics of the shroud structure 40 of the cooling fan 21]
(1)
In the shroud structure 40 of the cooling fan 21 according to the present embodiment, as shown in FIG. 8 and the like, the case portion 41 attached so as to cover the outer peripheral portion of the blade member 21a of the cooling fan 21 and the rotation track of the blade member 21a. A projecting portion 42 formed so as to protrude from the case portion 41 to the left and right, and an inner wall portion 43 formed on the inner wall surface of the projecting portion 42 adjacent to the tip portion of the blade member 21a. As shown in FIG. 8, the inner wall portion 43 is formed along a direction in which air that is generated when the cooling fan 21 is driven to rotate and spreads radially outward.

  As a result, the inner wall surface (inner wall portion 43) of the projecting portion 42 is formed along the direction in which air spreads radially outward by the axial fan, so that the cooling fan 21 can be rotated. The wind can be efficiently sent to the cooling core 30 without hindering the air flow. As a result, generation of turbulent flow in the shroud structure 40 can be prevented, noise reduction can be measured, and cooling efficiency in the cooling core 30 can be improved.

(2)
In the shroud structure 40 of the cooling fan 21 of the present embodiment, as shown in FIG. 8, the inner wall portion 43 of the shroud structure 40 is formed along the above-described air flow direction. It is formed along the shape of the tip portion of the blade member 21 a constituting the member 21.

  Thereby, the clearance gap between the case part 41 of the shroud structure 40 and the inner wall surface (inner wall part 43) of the overhang | projection part 42, and the front-end | tip part of the blade member 21a when the blade member 21a rotates can be made substantially constant. it can. As a result, the pressure fluctuation in the shroud structure 40 when the blade member 21a rotates can be minimized, and the air flow can be made smooth. Therefore, it is possible to reduce noise and improve cooling efficiency.

(3)
In the shroud structure 40 of the cooling fan 21 of the present embodiment, as shown in FIG. 9B, an inner wall portion 43 that is an inner wall surface of the projecting portion 42 is formed so as to include two R portions 43a and 43b. Yes.
As a result, a smooth curved surface can be formed on the inner wall surface side of the overhanging portion 42 to have a shape along the air flow direction. As a result, generation of turbulent flow in the shroud structure 40 can be prevented, and noise can be reduced and cooling efficiency can be improved.

(4)
As shown in FIG. 5, the shroud structure 40 of the cooling fan 21 of the present embodiment is disposed so as to be opposed to the left and right ends of the cooling core 30.
Thereby, the largest cooling fan 21 can be installed with respect to the cooling core 30 which is a cooling object. As a result, by sending a sufficient amount of air to the cooling core 30, the cooling efficiency in the cooling core 30 can be improved, and noise can be reduced.

(5)
As shown in FIG. 5, the cooling unit 20 of the present embodiment includes the above-described shroud structure 40 of the cooling fan 21 and the cooling fan 21.
Thereby, it is possible to obtain the cooling unit 20 capable of improving the cooling efficiency as well as reducing the noise described above.

(6)
As shown in FIG. 4, in the cooling unit 20 of the present embodiment, a cooling fan 21 (blade member 21a) is directly connected to the engine 6a, and is driven to rotate by the engine 6a.
As a result, the engine 6a can be used as it is as a rotational drive source of the cooling fan 21, so that the configuration can be simplified.

(7)
As shown in FIG. 4, the cooling unit 20 of the present embodiment is disposed on the downstream side of the cooling core 30 in the direction in which the air generated by the cooling fan 21 flows (see the arrow in FIG. 4).
Thereby, even in the so-called intake-type cooling fan 21, the flow of air passing through the shroud structure 40 can be made smoother, noise in the shroud structure 40 can be reduced, and cooling efficiency in the cooling core 30 can be improved. it can.

[Other Embodiments]
As mentioned above, although one Embodiment of this invention was described, this invention is not limited to the said embodiment, A various change is possible in the range which does not deviate from the summary of invention.
(A)
In the above-described embodiment, as illustrated in FIG. 4, the configuration in which the cooling fan 21 is rotationally driven by directly connecting the engine 6 a has been described as an example. However, the present invention is not limited to this.

For example, as shown in FIG. 10, the cooling fan 121 may be rotationally driven by a hydraulic drive motor 120 disposed in the vicinity of a cooling core such as a radiator.
In this case, compared to a cooling fan that is driven by rotation directly connected to the engine, the engine can be designed with negligible influence due to vibrations of the engine. Therefore, the clearance between the cooling fan and the inner wall surface of the shroud structure is reduced. Can be minimal. As a result, the air flow in the vicinity of the shroud structure becomes smoother, and it is possible to obtain effects such as noise reduction and improvement of cooling efficiency of the cooling core.

(B)
In the above embodiment, as illustrated in FIG. 4, the so-called intake type cooling unit 20 in which the cooling fan 21 is disposed on the downstream side of the cooling core 30 in the air flowing direction has been described as an example. However, the present invention is not limited to this.
For example, by arranging the cooling fan and the shroud structure so that the air flow direction and the shroud structure are in the same positional relationship as the above-described intake-type cooling unit, the upstream side of the cooling core such as a radiator is provided. The present invention can also be applied to a so-called blowout type cooling unit in which a cooling fan is arranged on the side.

(C)
In the above embodiment, as shown in FIG. 6 and the like, the cooling fan 21 has been described as an example using an axial fan. However, the present invention is not limited to this.
For example, you may comprise a cooling unit using other types of ventilation fans, such as a mixed flow fan.
(D)
In the above-described embodiment, an example in which the radiator 31, the oil cooler 32, and the after cooler 33 are used as the heat exchanger constituting the cooling core 30 has been described. However, the present invention is not limited to this.

For example, the cooling core disposed to face the shroud structure of the cooling fan according to the present invention may be a radiator alone, another heat exchanger, or a combination thereof.
(E)
In the said embodiment, as shown in FIG. 1, the hydraulic excavator 1 was mentioned as an example and demonstrated as a construction machine to which the shroud structure 40 of the cooling fan 21 of this invention is applied. However, the present invention is not limited to this.

  For example, in addition to the hydraulic excavator, the present invention can be similarly applied to other construction machines such as a wheel loader.

  Since the shroud structure of the cooling fan of the present invention has an effect that the flow of air in the overhanging portion can be smoothed and the noise can be reduced with a simple configuration, the cooling unit including the cooling fan is mounted. Widely applicable to various work machines.

1 is an overall view showing the configuration of a hydraulic excavator equipped with a cooling fan shroud structure according to an embodiment of the present invention. The perspective view which shows the structure of the engine room and counterweight periphery mounted behind the hydraulic excavator of FIG. The perspective view which shows the state which opened the engine hood attached to the upper surface of the engine room of FIG. The top view which shows the structure in the engine hood of FIG. The elements on larger scale of FIG. FIG. 6 is a perspective view illustrating a configuration of the cooling fan of FIG. 5. The front view which looked at the cooling fan of FIG. 6 from the other side. FIG. 8 is a cross-sectional view taken along line AA in FIG. 7. (A)-(c) is the BB line of the case part which comprises the shroud structure of FIG. 7, CC line, DD sectional view taken on the line. The front view which shows the structure of the cooling fan which concerns on other embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hydraulic excavator 2 Lower traveling body 3 Swivel base 4 Working machine 5 Counterweight 6 Engine room 6a Engine 9 Equipment room 10 Cab 11 Boom 11a Hydraulic cylinder 12 Arm 12a Hydraulic cylinder 13 Bucket 13a Hydraulic cylinder 14 Engine hood 14a Handle 20 Cooling unit 21 Cooling fan 21a Blade member 30 Cooling core 31 Radiator 32 Oil cooler 33 After cooler 35 Air cleaner 40 Shroud structure 41 Case portion 42 Overhang portion 43 Inner wall portions 43a and 43b R portion 120 Hydraulic drive motor 121 Cooling fan

Claims (8)

A cooling fan shroud structure attached so as to cover an outer peripheral portion of the cooling fan that generates a flow of air blown to the cooling core,
A case portion disposed close to the outer peripheral portion of the cooling fan;
A part of the case part, and a projecting part formed so as to project to the outer peripheral side in accordance with the rotation orbit of the cooling fan;
An inner wall portion that is disposed on the inner peripheral surface side facing the cooling fan in the projecting portion, and is formed along a flow of air that is generated outwardly in the radial direction generated by rotation of the cooling fan;
A cooling fan shroud structure. The inner wall portion is formed along the shape of a plurality of blade members constituting the cooling fan in a cross-sectional view along the rotation axis direction of the cooling fan.
The shroud structure of the cooling fan according to claim 1. The inner wall portion is configured to include a plurality of R portions.
The shroud structure of the cooling fan according to claim 1 or 2. The overhanging portion is disposed opposite to the end of the cooling core,
The shroud structure of the cooling fan of any one of Claim 1 to 3. The shroud structure of the cooling fan according to any one of claims 1 to 4,
The cooling fan;
A cooling core disposed in a flow of air generated by the cooling fan;
Construction machine cooling unit equipped with. The cooling fan is driven to rotate by an engine mounted on the construction machine.
The construction machine cooling unit according to claim 5. The cooling fan is rotationally driven by a hydraulic drive motor mounted on the construction machine,
The construction machine cooling unit according to claim 5. The cooling fan is disposed on the downstream side of the cooling core in a direction in which air supplied to the cooling core flows.
The cooling unit for a construction machine according to any one of claims 5 to 7.

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