JP2007009730A - Cooling device and cooling device of work machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To increase cooling performance in normal operation while effectively preventing a suction reverse flow from occurring near the downstream side rotating center of an axial fan by a simple structure in a cooling device and a cooling device of a work machine. <P>SOLUTION: This cooling device comprises the axial fan 1 having a vane fixing part 1a driven by a rotating drive source and vanes 1b roughly radially extended from its outer peripheral surface to the outside and flowing cooling air, an object (2) to be cooled by the cooling air, and a straightening member 5 disposed on the downstream side of the cooling fan more than the axial fan 1 near the outer peripheral surface of the vane fixing part 1a. The straightening member 5 is disposed in a direction that is along the cooling air discharged from the axial fan 1 and that stops the reverse flow occurring near the downstream side rotating center part of the axial fan 1 when the axial fan 1 is stalled. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a cooling device using an axial fan and a cooling device for a work machine.

  Today, various work machines such as traveling work machines such as hydraulic excavators and wheel loaders and stationary work machines such as cranes are used in various fields such as construction sites, harbors, factories, and the like. Work machines are generally used in harsh environments such as excavation of rocks in dams, tunnels, rivers, roads, etc., and demolition of buildings and buildings, but in such environments they are used for equipment such as engines and hydraulic pumps. The applied load is high, and the engine temperature and hydraulic oil temperature are likely to rise.

For this reason, these work machines are equipped with a cooling device including a heat exchanger such as a radiator or an oil cooler and an axial fan, and the cooling air taken in by the operation of the axial fan flows through the radiator. The hydraulic fluid flowing through the engine coolant and oil cooler is cooled.
For example, in Patent Document 1, an axial fan and a heat exchanger are provided in an engine room, and a flow of cooling air sucked from the outside of the engine room is circulated inside the heat exchanger by the axial fan. A heat exchange device for performing the exchange is described.

In this heat exchange device, a heat exchanger is disposed upstream of the axial fan in the engine room, and the heat exchanger is cooled by cooling air sucked into the axial fan, and the axial fan is cooled by the cooling air. The wind is discharged out of the engine room. With such a configuration, heat exchange is efficiently performed in the engine room.
In the axial fan as described above, the cooling air is sucked along the rotation axis direction of the axial fan substantially vertically from the upstream side front face, and accompanied by the turning of the axial fan in the turning direction. It is blown out downstream as an axial flow. That is, the cooling air blown out from the axial fan includes a velocity component flowing in the downstream direction perpendicular to the rotational surface of the axial fan and a velocity component flowing in the centrifugal / swirl direction.

  By the way, the blowing performance of the axial fan is generally shown by a performance curve as shown in FIG. 9, and when the pressure loss on the upstream side of the axial fan is small, the amount of air that goes straight in the downstream direction of the cooling air increases. It is known that this air volume decreases as the pressure loss increases. That is, in the state where the pressure loss is small, the velocity component in the downstream direction is relatively larger than the velocity component in the centrifugal / swirl direction in the axial flow blown out from the axial fan, as shown in FIG. As shown, the cooling air sucked perpendicularly to the rotational surface of the axial fan [arrow X in FIG. 11A] is substantially linearly downstream in the side view [arrow Y in FIG. 11A]. Blown out.

On the other hand, if dust or dust adheres to the ventilation openings in the engine room, heat exchangers, filters, etc., and the cooling air flow path is partially blocked, The pressure difference increases and a stall phenomenon may occur on the blade surface of the axial fan.
The stall phenomenon is a phenomenon in which the air flow is separated from the blade surface to cause turbulence. When this phenomenon occurs on the blade surface of the axial fan, as shown in FIG. 11 (b), the air flow separated from the blade surface swirls in the swirling direction of the axial fan, while the centrifugal / swirling direction [FIG. ) Blown out to the middle arrow Z ₁ ], negative pressure is generated in the vicinity of the rotational center of the axial fan, and a reverse flow (arrow Z _{2 in} the figure) is generated while swirling upstream. Such suction backflow becomes more prominent as the pressure loss increases.As the airflow of the axial fan decreases, the amount of suction from the inside of the axial fan increases and the intake performance of the axial fan is reduced. It will cause a significant decrease.

In order to solve the above problem, the technique described in Patent Document 1 has a truncated cone-shaped backflow prevention member in the vicinity of the rotation center portion on the downstream side of the axial fan, with its small diameter surface oriented toward the axial fan. The structure to provide is described. That is, the flow speed of the swirling air blown from the axial fan is reduced while being guided along the outer peripheral surface of the backflow preventing member in the radial direction. Thereby, generation | occurrence | production of the negative pressure in the downstream rotation center part of an axial fan can be suppressed, and suction | inhalation backflow can be prevented now.
JP 2002-200140 A

  However, in the technique described in Patent Document 1 described above, for example, as shown in FIG. 11A, during normal operation where the pressure loss on the upstream side of the axial fan is small, that is, cooling air with a small centrifugal / swivel speed component. Even when the airflow is blown out from the axial fan so as to go straight downstream, the backflow preventing member directs the cooling air to the outside in the radial direction of the axial fan, and the backflow preventing member acts as a flow path resistance. It will be.

Therefore, during normal operation, the intake performance of the axial fan is reduced and the cooling effect in the heat exchanger is reduced as compared with the case where there is no backflow prevention member. For this reason, a backflow prevention member that does not hinder the flow of normal cooling air is desired when the operation state is such that no suction backflow occurs in the vicinity of the downstream rotational center of the axial fan.
The present invention has been made in view of such problems, and can effectively improve the cooling performance even during normal operation while effectively preventing the suction backflow near the downstream rotation center of the axial fan with a simple configuration. An object of the present invention is to provide a cooling device and a cooling device for a work machine.

  In order to achieve the above object, a cooling device of the present invention (Claim 1) includes a blade fixing portion driven by a rotational drive source, and a blade extending radially outwardly from the outer peripheral surface of the blade fixing portion. An axial fan that circulates cooling air, an object to be cooled by the cooling air, and an outer peripheral surface of the blade fixing portion on the downstream side of the cooling air from the axial fan. A straightening member, and the straightening member is oriented along the cooling air blown from the axial fan, and in the vicinity of the rotational center of the downstream of the axial fan, when the axial fan is stalled. It is characterized by being arranged in a direction to prevent the generated backflow.

  The object to be cooled here includes a heat exchanger such as a radiator, an oil cooler, and a condenser of an air conditioner outdoor unit that cools engine coolant or hydraulic oil, or includes a cooling package constituted by these. Further, the reverse flow generated when the axial flow fan is stalled, that is, the suction reverse flow in the vicinity of the rotation center of the downstream side of the axial flow fan, includes a velocity component in the same turning direction as that of the axial flow fan.

The straightening member is inclined from the state in which the plate surface is oriented perpendicularly to the rotational surface of the axial fan to the swirling direction and the downstream direction of the axial fan, and is fixed substantially radially from the rotational shaft. (Claim 2).
Further, it is preferable to include a shroud that covers the space between the axial fan and the object to be cooled to improve the cooling efficiency of the object to be cooled, and a fixing member that connects and fixes the rectifying member and the shroud ( Claim 3).

The straightening member is formed in a hollow cylindrical shape having substantially the same diameter as the boss and is arranged coaxially with the boss, and extends outward from the outer peripheral surface of the annular portion as the plate surface. It is preferable to have a rectifying blade part (claim 4).
A rectifying plate disposed outside the wing tip of the axial fan, the rectifying plate is oriented along the flow direction of the cooling air, and the stall of the axial fan It is preferably arranged in a direction to prevent backflow outside the blade tip portion that sometimes occurs.

The rectifying plate is preferably fixed substantially radially from the rotating shaft on the outer side of the blade end portion of the axial fan with the plate surface oriented substantially parallel to the flow direction of the cooling air. Item 6).
In this case, it is preferable that the current plate is disposed on an arbitrary plane including the rotation axis of the axial fan (Claim 7), or the current plate includes the rotation axis. Preferably, the plate surface is oriented so as to form a predetermined inclination angle with respect to an arbitrary plane, and is formed in a vortex shape so as to converge on the rotation axis in the swirling direction of the axial fan. 8) Alternatively, the flow straightening plate has a swirling direction of the axial fan and an axis of the axial fan with respect to an axis perpendicular to the rotation axis from a state in which the plate surface is oriented parallel to the flow direction of the cooling air. It is preferable to incline in the downstream direction (claim 9).

Preferably, the axial fan is provided on the downstream side of the cooling air with respect to the object to be cooled, and the rectifying plate is fixed in the shroud.
The work machine cooling device according to the present invention (Claim 11) includes a boss driven by a rotational drive source mounted on the work machine, and blades extending radially outward from the outer peripheral surface of the boss. An axial fan that is disposed in the engine room and distributes the cooling air from the outside of the work machine to the engine room, and a cooling target that is mounted in the engine room and is cooled by the cooling air. A rectifying member disposed near the outer peripheral surface of the boss on the downstream side of the cooling air from the axial fan, and the rectifying member is oriented along the cooling air blown from the axial fan In addition, it is characterized in that it is arranged in the direction of preventing the reverse flow generated when the axial fan is stalled in the vicinity of the downstream rotation center portion of the axial fan.

According to the cooling device of the present invention (Claim 1), it is possible to prevent the suction backflow that occurs in the vicinity of the rotation center of the downstream side of the axial fan at the time of stall, and the blowing effect of the axial fan can be enhanced. Moreover, in the state where the suction back flow does not occur, the flow of the normal cooling air is not hindered and the air blowing effect of the axial flow fan can be maintained. As a result, the cooling efficiency of the object to be cooled can be increased.
Further, according to the cooling device of the present invention (Claim 2), the rotating shaft is inclined from the state in which the plate surface of the rectifying member is oriented perpendicularly to the rotating surface of the axial fan, in the swirling direction and downstream of the axial fan. Therefore, it is possible to prevent the suction and backflow without interfering with the cooling air blown from the axial fan, and to enhance the blowing effect of the axial fan and the cooling effect of the cooling target.

Further, according to the cooling device of the present invention (Claim 3), the rectifying member can be easily fixed near the downstream rotation center portion of the axial fan by using the shroud.
Further, according to the cooling device of the present invention (Claim 4), it is easy to dispose the rectifying member at a position corresponding to the flow position of the suction backflow that can occur in the vicinity of the downstream rotation center portion of the axial fan. Further, the configuration is simple and the formation of the flow regulating member is facilitated.

Further, according to the cooling device of the present invention (Claim 5), it is possible to prevent the swirl backflow generated at the blade tip portion at the time of stall without disturbing the flow of the cooling air circulated by the axial flow fan, and to blow the axial flow fan. The effect and the cooling effect of the object to be cooled can be enhanced.
Further, according to the cooling device of the present invention (Claim 6), since the rectifying plate is fixed substantially parallel and substantially radially to the flow direction of the cooling air, the flow of the cooling air from the upstream side of the axial fan is prevented. Therefore, it is possible to prevent the swirling back flow without increasing the air blowing effect of the axial fan and the cooling efficiency of the cooling target.

Moreover, according to the cooling device of the present invention (Claim 7), the configuration is simple and the arrangement of the current plate is facilitated.
Further, according to the cooling device of the present invention (Claim 8), in the front view of the axial fan, the plate surface can be oriented substantially vertically with respect to the swirling backflow that blows outward in the swirling direction, and the effect of preventing swirling backflow is enhanced. be able to.

Further, according to the cooling device of the present invention (Claim 9), in the side view of the axial flow fan, the plate surface can be oriented substantially vertically with respect to the swirling backflow blown upstream, and the effect of preventing swirling backflow is further enhanced. be able to.
Moreover, according to the cooling device of the present invention (Claim 10), the current plate can be easily arranged and can be fixed securely. Use of the shroud facilitates the arrangement of the current plate at the fan blade end. Further, the current plate can be protected by the shroud.

  Moreover, according to the cooling device for a working machine of the present invention (claim 11), the suction backflow that occurs near the downstream rotation center of the axial fan during a stall can be prevented, and the blowing effect of the axial fan can be enhanced. Moreover, in the state where the suction backflow does not occur, the axial flow fan does not disturb the flow of the cooling air introduced from the outside of the machine body into the engine room, and the normal cooling air flow is not obstructed. Can be kept. As a result, the cooling effect of the cooling package as the cooling target can be increased.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 5 and 10 are diagrams for explaining a cooling device for a working machine as one embodiment of the present invention, FIG. 1 is an exploded perspective view of the apparatus, and FIG. 2 is a front view of the apparatus. 1 is a perspective view showing an air flow, (a) is an air flow during normal operation of the apparatus, (b) is an air flow during a stall, and FIG. 4 is a book of FIG. FIG. 5 is a schematic view for explaining the gradient of the rectifying member, and FIG. 10 is a perspective view of a work machine on which the apparatus is mounted.

[Constitution]
As shown in FIG. 10, a work machine 9 to which the present invention is applied includes a lower traveling body 7 having a traveling device with an endless track, and an upper revolving body 8 that is turnably mounted on the upper portion of the lower traveling body 7. It is prepared for. A hydraulically driven working device and a cab are provided in a front portion of the upper revolving body 8 and a counterweight and an engine room 11 for balancing the weight of the airframe are provided in a rear portion of the body. Inside the engine room 11, the engine 11a and the cooling device 10 according to the present invention are installed.

As shown in FIG. 1, the cooling device 10 includes an axial fan 1, a heat exchanger 2 as a cooling target, a shroud 4, and a rectifying member 5.
The axial fan 1 includes a boss (blade fixing portion) 1a that is rotationally driven by a fan motor (not shown) driven by an engine 11a, and surrounding blades 1b. The wing 1b extends radially outwardly from the outer peripheral surface of the boss 1a, is driven to rotate together with the boss 1a, sucks outside air from the outside of the work machine 9, and flows into the engine room 11 as cooling air. Let In this embodiment, the axial flow fan 1 in which the blade 1b is fixed around the boss 1a will be described below. The boss 1a is a fastening member between the blade 1b and a rotating shaft such as a fan motor. It is given as a general example.

Further, the cooling air is sucked into the axial fan 1 substantially parallel to the rotation axis C, and is blown out downstream as an axial flow accompanied by the turning of the axial fan 1 in the turning direction. Further, the blowing performance of the axial fan 1 is shown by the performance curve shown in FIG.
The heat exchanger 2 is a device that performs heat exchange between cooling air and a heat medium (for example, engine cooling water or hydraulic oil), and is disposed on the upstream side of the cooling air from the axial fan 1. Hereinafter, the upstream side and the downstream side of the cooling air are simply referred to as the upstream side and the downstream side. The heat exchanger 2 is a cooling package including a radiator that cools engine cooling water, an oil cooler that cools working oil of a work machine, and the like.

  The shroud 4 covers the space between the heat exchanger 2 and the axial fan 1 and, as shown in FIGS. 1 and 4, from the outer peripheral end of the heat exchanger 2 to the blade end of the axial fan 1. It extends outward and is formed so as to cover the entire space on the upstream side of the axial fan 1. Thereby, only the air that has passed through the inside of the shroud 4, that is, the inside of the heat exchanger 2, is sucked from the upstream side of the axial fan 1 as cooling air, and the air is sucked from the outside of the shroud 4. Absent. Accordingly, the intake efficiency of the axial fan 1 is increased.

As shown in FIG. 1, the rectifying member 5 includes an annular portion 5a and a rectifying blade portion 5b around the annular portion 5a. The annular portion 5a is formed in a hollow cylindrical shape having substantially the same diameter as the boss 1a. The annular portion 5a is fixed on the downstream side of the axial fan 1 with its central axis aligned with the rotational axis C of the axial fan 1. The The rectifying blade portion 5b is composed of a plurality of plates extending outward from the outer peripheral surface of the annular portion 5a.
The rectifying blade portion 5 b is configured such that each plate surface is inclined from the orientation state perpendicular to the rotational surface of the axial fan 1 in the swirling direction and the downstream direction of the axial fan 1. As shown in FIG. 5, in general, the blowing direction of the cooling air from the axial fan 1 is a speed component V _{1 in the} downstream direction perpendicular to the rotation surface of the axial fan 1, and centrifugal accompanying the rotation of the axial fan 1. The velocity component V ₂ in the direction and the velocity component V _{3 in the} turning direction are expressed by a velocity vector direction V _A. In this embodiment, to match the direction of the inclination gradient of the rectifier wings 5b were synthesized and vector V ₁ and the vector V ₃ vector. As a result, the plate surface of the rectifying blade portion 5 b is substantially parallel to the cooling air blowing direction V _A blown from the axial fan 1.

Each vector V ₁ , V _2, and V ₃ varies depending on the ventilation performance of the axial fan 1, upstream pressure loss, and the like. Here, each vector obtained during experiments and tests is obtained during normal operation. Based on the magnitudes of V ₁ , V _2, and V ₃ , the gradient of the rectifying blade portion 5b is set.
The rectifying blade portion 5b includes a plurality of such plate surfaces, and as shown in FIGS. 1 and 2, an annular portion is provided in the vicinity of the outer peripheral surface of the boss 1a on the downstream side of the cooling air from the axial fan 1. 5a is fixed at substantially equal intervals in the circumferential direction and substantially radially from the rotation axis C. The axial fan 1 is driven to rotate about the rotation axis C. However, as shown in FIGS. 2 and 4, the rectifying member 5 is connected to the shroud 4 by a fixing member 6 and fixed. do not do.

[Action / Effect]
With the configuration as described above, the work machine cooling device of the present embodiment has the following operations and effects.
First, when the pressure loss on the upstream side of the axial fan 1 is small (in the normal operation state), as shown in FIG. It is sucked in almost parallel. The cooling air that has passed through the heat exchanger 2 and has exchanged heat with the heat medium is blown downstream as an axial flow accompanied by a swirling of the axial fan 1 in the swirling direction. Here, as shown in FIG. 4, the plate surface of the rectifying blade portion 5b is substantially parallel to the direction of the cooling air blown out from the axial fan 1, so that the cooling air flows into the rectifying blade portion 5b. It distributes without resistance along the plate surface. Accordingly, as shown in FIG. 3A, the circulation of the cooling air is not hindered.

Also, in this state, the cooling air on the downstream side of the axial fan 1 has a relatively larger speed component in the downstream direction than the speed component in the centrifugal / swirl direction. Is maintained.
On the other hand, when dust or dust adheres to the ventilation opening of the engine room 6, the inside of the heat exchanger 2, the filter, etc., the flow path of the cooling air becomes narrow, and the pressure loss on the upstream side of the axial fan 1 becomes large. The speed component in the downstream direction of the cooling air on the downstream side of the axial fan 1 is reduced, and the cooling air is blown out so as to spread in the centrifugal / swirl direction. Here, even if a stall phenomenon occurs and a suction backflow near the rotation center portion occurs as shown in FIG. 11B, the suction backflow is caused by the plate surface of the rectifying vane plate 5b as shown in FIG. Blocked.

In other words, the plate surface of the rectifying vanes 5b, as shown in FIG. 5, are formed parallel to the direction of the synthesized velocity vector and a velocity component V ₃ to velocity component V ₁ and the turning direction of the downstream direction On the other hand, the suction reverse flow near the rotation center of the axial fan 1 has a speed component −V _{1 in the} upstream direction (the reverse direction of V ₁ ) and a speed component V _{3 in} the swirling direction of the axial fan 1. Therefore, the plate surface of the rectifying vane plate 5b works to prevent suction and backflow. Therefore, as shown by the arrow in the broken line frame in FIG. 3B, it is possible to make it difficult for the suction backflow to flow to the upstream side of the rectifying blade 5b.

Since the rectifying member 5 is arranged so that the gradient of the rectifying wing portion 5b coincides with the direction of the vector obtained by combining the vector V ₁ and the vector V ₃ , even during the stall shown in FIG. The flow of the cooling air blown out from the axial fan 1 is not blocked by the rectifying blade plate 5.

Further, since the rectifying member 5 is connected and fixed to the shroud 4 by the fixing member 6, it can be easily fixed near the rotation center portion on the downstream side of the axial fan 1.
As described above, according to the present cooling device, it is possible to prevent the suction and backflow with a simple configuration, improve the air blowing effect of the cooling air, and increase the heat exchange efficiency in the heat exchanger 2.

[Modification]
Next, a first modification of the present invention will be described with reference to FIG. In this 1st modification, in addition to the structure of the above-mentioned embodiment, the baffle plate 3 fixed in the shroud 4 is provided. Hereinafter, the same components as those in the above embodiment are denoted by the same reference numerals, and description thereof is omitted.

  The rectifying plate 3 is composed of a plurality of vanes that rectify the cooling air. As shown in FIG. 6, each plate surface is oriented parallel to the flow direction of the cooling air, and outward of the end of the blade 1 b. At the upstream side. Further, the current plate 3 is arranged on the arbitrary plane including the rotational axis C of the axial fan 1, the plate surfaces are arranged at substantially equal intervals in the circumferential direction of the axial fan 1, and radially with respect to the axial fan 1. Be placed. That is, the extended surfaces of the plate surfaces of the rectifying plate 3 are arranged to intersect so as to share the rotation axis C. The rectifying plate 3 extends from the outside of the blade end of the axial fan 1 to the shroud end surface 4a.

The reason why the current plate 3 is arranged in this way is as follows. That is, when the stall phenomenon occurs on the blade surface of the axial fan 1, not only the suction backflow described above occurs as shown in FIG. 11 (b), but also the swirl backflow to the upstream side outside the blade tip [Fig. 11 (b), an arrow Z ₃ ] is generated. Such swirl backflow becomes more prominent as the pressure loss increases, and the backflow from the blade tip increases as the amount of air blown by the axial fan 1 decreases.

  Since the airflow that has flowed back here is sucked again to the upstream side of the axial fan 1, the intake air amount sucked substantially vertically from the upstream side of the axial fan 1, that is, the sucked outside air is reduced. Become. Therefore, the intake capacity of the axial fan is further reduced, and the cooling efficiency of the heat exchanger is also reduced. Therefore, in this modification, the rectifying plate 3 is provided in order to prevent swirl backflow from the blade tip.

In this case, even if the stall phenomenon occurs and the turbulent air flow separated from the blade surface swirls in the swirling direction of the axial fan 1 and tries to flow backward outside the blade tip, it is arranged outside the blade tip. The rectified plate 3 thus made works to prevent the swirling backflow.
That is, since the plate surface of the rectifying plate 3 is arranged radially with respect to the axial fan 1, the swirl reverse flow outside the blade end including the swirl component in the same direction as the swirl direction of the axial fan 1 is It will collide with the plate surface. Therefore, the swirl backflow is blocked by the plate surface and is not sucked again to the upstream side of the axial flow fan 1.

  Since the rectifying plate 3 is disposed outside the blade end portion of the axial fan 1, the flow of the cooling air sucked substantially vertically from the upstream side of the axial fan 1 is shroud even in the stalled state. It is not blocked by the rectifying plate 3 fixed in 4. Moreover, since the current plate 3 is fixed inside the shroud 4, it is easy to fix the current plate 3 outside the blade tip. Further, the current plate 3 can be protected by the shroud 4 and the current plate 3 can be securely fixed.

As described above, according to the first modification, it is possible to prevent the swirl backflow from the blade tip portion with a simple configuration, improve the circulation efficiency of the cooling air, and increase the heat exchange efficiency in the heat exchanger 2. it can.
Next, a second modification of the present invention will be described with reference to FIG. Here, instead of the rectifying plate 3 of the first modification, a second rectifying plate 3a having a different arrangement configuration is provided.
As shown in FIG. 7, the second rectifying plate 3 a has a spiral shape (that is, the rotational axis of the axial fan 1) that converges on the rotational axis C in the turning direction of the axial fan 1 (black arrow in FIG. 7). Are arranged in a vortex shape diffusing in a swirling direction opposite to the swirling direction of the axial flow fan 1. That is, the inner end portion of the rectifying plate 3 in the above-described embodiment is arranged to be inclined in the turning direction of the axial fan 1, and each plate surface of the second rectifying plate 3 a is the rotation axis of the axial fan 1. Is set to an orientation angle that forms a predetermined inclination angle θ with respect to an arbitrary plane including.

  According to such a configuration, as shown in FIG. 7, when a swirl reverse flow (white arrow in FIG. 7) occurs outside the blade tip portion of the axial flow fan 1 due to a stall phenomenon, the front surface of the axial flow fan 1. In view, the plate surface of the second rectifying plate 3a is arranged substantially perpendicular to the swirling back flow. That is, since the swirling backflow collides with the plate surface substantially perpendicularly, the swirling backflow can be more effectively blocked as compared with the above embodiment.

Thus, according to this modification, the effect of preventing the swirl backflow can be enhanced with a simple configuration.
Note that, as shown in FIG. 7, focusing on the speed component of the cooling air blown from the vicinity of the blade tip of the axial fan 1, the direction of the speed component in the swirl direction and the speed component in the centrifugal direction are combined. On the other hand, it is preferable to set the predetermined inclination angle θ so that the plate surface of the second rectifying plate 3a is vertical.

[Others]
As mentioned above, although embodiment of this invention and its modification were demonstrated, this invention is not limited to these embodiment, Various deformation | transformation can be implemented in the range which does not deviate from the meaning of this invention.
For example, in the first modified example described above, the rectifying plate 3 extends from the outside of the blade end portion of the axial flow fan 1 to the shroud end surface 4a, but the extending length of the rectifying plate 3 may be shortened. . That is, since the swirl counterflow caused by the stall phenomenon is generated outside in the vicinity of the blade end portion of the axial fan 1, the flow straightening plate 3 only needs to have a plate surface length that blocks the swirl counterflow. Specifically, as shown in FIG. 8, the rectifying plate 3 b is arranged radially within a range of a predetermined distance R (where R> radius of the axial fan 1) from the rotational axis of the axial fan 1. It can be considered. By setting the predetermined distance R appropriately, it is possible to obtain substantially the same operational effects as the above-described embodiment.

  In the first and second modifications described above, the rectifying plate 3 is oriented in parallel with the cooling air flow direction, but the plate surface may be slightly inclined with respect to the cooling air flow direction. For example, the rectifying plate 3 is inclined in the swiveling direction of the axial fan 1 and the downstream direction of the axial fan from an orientation that is parallel to the rotational axis C of the axial fan 1 with respect to an arbitrary axis that intersects the rotary axis C perpendicularly. It is possible to make it.

  That is, the swirl reverse flow generated in association with the stall phenomenon has a three-dimensional orientation characteristic of swirling in the swirl direction of the axial fan 1 while flowing back upstream, and therefore the axial flow fan 1 is viewed from the front and side. Therefore, the effect of preventing swirl backflow can be further enhanced by orienting the current plate 3 substantially perpendicularly to swirl backflow (that is, three-dimensionally perpendicular to swirl backflow).

In the first modification described above, the plate surface of the rectifying plate 3 is formed in a substantially flat shape, but may be formed in a curved surface according to the orientation characteristics of the swirling back flow, or a combination of the flat surface and the curved surface. It may be a flat plate surface.
In the above-described embodiment, the heat exchanger 2 is disposed on the upstream side of the axial fan 1. However, the heat exchanger 2 may be disposed on the downstream side of the axial fan 1. The cooling device of the present invention can improve the air blowing effect of the axial fan 1 regardless of the arrangement order, and can improve the heat exchange efficiency in the heat exchanger 2.

In the above-described embodiment, the rectifying plate 3 is fixed inside the shroud 4. However, the rectifying plate 3 may be provided outside the blade end portion of the axial flow fan 1.
Further, in the above-described first modification, the rectifying plate 3 is fixed to the outside of the blade tip portion 1a, and this rectifying plate 3 is oriented along the flow direction of the cooling air, and As long as it is arranged in a direction to prevent the swirling backflow, it does not have to be fixed. That is, the rectifying plate 3 may be provided as a movable plate. For example, the orientation characteristics of the swirling back flow vary depending on various conditions such as the rotational speed of the axial fan 1 and the amount of air blown. By adopting a configuration in which the angle is controlled according to the various conditions, it is possible to enhance the effect of preventing swirl backflow according to each condition.

Similarly, in the above-described embodiment, the rectifying member 5 is fixed on the downstream side of the axial fan 1, but the rectifying member 5 is oriented along the cooling air blown from the axial fan 1. And if it is arrange | positioned in the direction which prevents the suction | inhalation reverse flow which arises at the time of a stall in the downstream rotation center part vicinity of the axial flow fan 1, it does not need to be fixed. That is, the rectifying member 5 may be provided as a movable member. For example, among the cooling air flow blown from the axial flow fan 1, and calculates the velocity vector V ₃ to the velocity vector V ₁ and the turning direction of the downstream direction, the orientation of the rectifying member 5 in accordance with these values It can be considered that the angle is controlled.

  In addition, although the above-mentioned embodiment applies this invention to the cooling device provided in the engine room of a working machine, the application object of this invention is not limited to this. For example, when the present invention is applied to a residential air conditioner apparatus, the present invention can be applied to an air conditioner outdoor unit provided with an axial fan for taking heat away from refrigerant condensed by a compressor. .

It is a disassembled perspective view of the cooling device of the working machine as one Embodiment of this invention. It is a front view of this apparatus of FIG. 1, Comprising: It is A arrow view of FIG. It is a perspective view which shows airflow, (a) shows the airflow at the time of normal operation of this apparatus, (b) shows the airflow at the time of a stall. It is BB sectional drawing of the state which assembled this apparatus of FIG. It is a schematic diagram explaining the gradient of a baffle member. It is a disassembled perspective view of the cooling device of the working machine as a 1st modification of this invention. It is sectional drawing of the cooling device of the working machine as a 2nd modification of this invention. It is sectional drawing of the cooling device of the working machine as a modification of this invention. It is a graph which shows the performance curve of a general axial fan. 1 is a perspective view of a work machine to which the present invention is applied. It is sectional drawing which shows the airflow in the conventional cooling device, (a) shows the airflow at the time of normal operation, (b) shows the airflow at the time of a stall.

Explanation of symbols

1 Axial fan 1a Boss (blade fixing part)
DESCRIPTION OF SYMBOLS 1b Blade | wing 2 Heat exchanger 3, 3b Current plate 3a 2nd current plate 4 Shroud 4a Shroud end surface 5 Current flow member 5a Annular part 5b Current flow blade part 6 Fixed member 7 Lower traveling body 8 Upper revolving body 9 Work machine 10 Cooling device 11 Engine Room 11a engine

Claims (11)

An axial fan having a blade fixing portion driven by a rotational drive source and blades extending radially outward from the outer peripheral surface of the blade fixing portion, and for circulating cooling air;
A cooling object cooled by the cooling air;
A rectifying member disposed near the outer peripheral surface of the blade fixing portion on the downstream side of the cooling air from the axial fan,
The rectifying member has a direction along the cooling air blown from the axial fan, and a direction to prevent a reverse flow generated when the axial fan is stalled in the vicinity of the downstream rotation center of the axial fan. A cooling device, which is arranged. The straightening member is inclined from the state in which the plate surface is oriented perpendicularly to the rotational surface of the axial fan to the swirl direction and the downstream direction of the axial fan, and is fixed substantially radially from the rotational shaft. The cooling device for a work machine according to claim 1, wherein A shroud that covers the space between the axial fan and the object to be cooled to improve the cooling efficiency of the object to be cooled;
The work machine cooling device according to claim 1, further comprising a fixing member that connects and fixes the flow regulating member and the shroud. The rectifying member is
An annular portion formed in a hollow cylindrical shape having substantially the same diameter as the blade fixing portion and disposed coaxially with the blade fixing portion;
The cooling device for a working machine according to any one of claims 1 to 3, further comprising a rectifying blade portion extending outward from an outer peripheral surface of the annular portion as the plate surface. A rectifying plate disposed outside the tip end of the axial flow fan,
The rectifying plate is disposed in a direction along the flow direction of the cooling air and in a direction that prevents a reverse flow outside the blade end portion that occurs when the axial fan is stalled. The cooling device according to any one of 1 to 4. The rectifying plate is fixed substantially radially from the rotating shaft outside the blade end of the axial flow fan with the plate surface oriented substantially parallel to the flow direction of the cooling air. Item 6. The cooling device according to Item 5. The cooling device according to claim 5, wherein the current plate is disposed on an arbitrary plane including a rotation axis of the axial fan. The rectifying plate has a spiral shape in which the plate surface is oriented so as to form a predetermined inclination angle with respect to an arbitrary plane including the rotating shaft, and converges on the rotating shaft in the turning direction of the axial fan. The cooling device according to claim 5, wherein the cooling device is formed as follows. The rectifying plate inclines the plate surface from a state of being oriented in parallel with the flow direction of the cooling air in a swirling direction of the axial fan and a downstream direction of the axial fan with respect to an axis perpendicular to the rotation axis. 6. The cooling device according to claim 5, wherein the cooling device is provided. The axial flow fan is provided on the downstream side of the cooling air from the object to be cooled, and the rectifying plate is fixedly installed in the shroud. The cooling device according to 1. A blade fixing portion driven by a rotary drive source mounted on the work machine, and a blade extending radially outward from the outer peripheral surface of the blade fixing portion, and disposed in an engine room An axial fan that circulates cooling air from the outside of the work machine into the engine room;
A cooling object mounted in the engine room and cooled by the cooling air;
A rectifying member disposed near the outer peripheral surface of the blade fixing portion on the downstream side of the cooling air from the axial fan,
The rectifying member has a direction along the cooling air blown from the axial fan, and a direction to prevent a reverse flow generated when the axial fan is stalled in the vicinity of the downstream rotation center of the axial fan. A cooling device for a work machine, wherein the cooling device is disposed.

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