JP2019052581A - Cooling fan for construction machine - Google Patents

Abstract

To provide a cooling fan for a construction machine capable of suppressing a counter flow in a clearance gap between a ring and a shroud in a case where reduction in the clearance gap between the ring and the shroud is limited.SOLUTION: A cooling fan 32 is disposed at an inner peripheral side of a shroud 33 and comprises multiple main wings 42 and a ring 43 which couples outer edges of the main wings 42. The main wings 42 are disposed in such a manner that at least one wing interval becomes wider than the other wing intervals. The ring 43 includes a diameter enlarged part 46 of which the discharge side is fan-shaped. The diameter enlarged part 46 is positioned closer to the discharge side than the shroud 33. Multiple wing piece parts 50 are disposed in an outer periphery of the diameter enlarged part 46. The wing piece parts 50 consist of multiple first wing piece parts 51 disposed in a first region R1 that is a portion of a wide wing interval P1 in the ring 43 and spread over a position of a front edge 42b (Wr) of a main wing 42 (Wr), and multiple second wing piece parts 52 disposed outside of the first region. The first wing piece part 51 is formed in such a shape that a stress generated in a coupling part with the ring 43 is mitigated further than the second wing piece part 52.SELECTED DRAWING: Figure 9

Description

  The present invention relates to a cooling fan for a construction machine that supplies cooling air to a heat exchanger such as a radiator, and more particularly to a cooling fan in which outer peripheral side ends of a plurality of blades are connected by a ring.

  In construction machines such as hydraulic excavators and dump trucks, a cooling unit including a heat exchanger such as a radiator or an oil cooler and a cooling fan that supplies cooling air at a flow rate required by the heat exchanger is generally used for an engine or the like. It is arrange | positioned in the vehicle body with the drive device of this cooling fan. As one type of cooling fan, a fan in which outer peripheral side ends of a plurality of blades are connected by a cylindrical member (ring), a so-called ring fan is known.

  Construction machines are required to improve the cooling efficiency of the cooling unit in order to improve reliability and save energy. As an effective means for improving the cooling efficiency of the cooling unit, there is an increase in the air volume of the cooling fan and an increase in efficiency. Patent Documents 1 and 2 are known as techniques aimed at increasing the air volume and increasing the efficiency of a cooling fan.

  The cooling device described in Patent Literature 1 includes an axial fan having a plurality of blades, and a shroud disposed between the axial fan and the heat exchanger. A ring (fan ring) is attached to the outer peripheral end of the blade of the axial fan so as to surround the blade over the entire circumference, and this fan is a so-called ring fan. The ring includes a protrusion that protrudes toward the outer periphery over the entire periphery. In the shroud, an adjustment plate divided into a plurality in the circumferential direction is variably fixed to the outer peripheral surface of the ring. The technology described in Patent Document 1 can be easily assembled with the above-described configuration, and further reduces the flow of air (cooling air) that flows backward from the fan discharge side to the suction side through the gap between the ring and the shroud. The air volume is increased.

  The fan-housing combination described in Patent Document 2 includes a ring fan (axial fan with a band) and a shroud (housing) for guiding an air flow, and the ring fan is positioned in the shroud. In the recirculation flow path between the ring (band-like portion) and the shroud, a steady flow control blade is arranged in a state connected to the shroud. The technique described in Patent Document 2 achieves high efficiency by reducing the vortex flow in the recirculation air flow that reversely flows through the recirculation flow path between the ring (band-like portion) and the shroud by the above configuration. is there.

  Further, an effective means for increasing the air volume and increasing the efficiency in a general fan is to reduce the backflow of the gap between the blade and the shroud by reducing the gap (tip clearance) between the blade and the shroud. In the case of a ring fan, the blades are replaced with a ring, but by reducing the gap between the ring and the shroud, the pressure loss of the gap increases. Can be expected.

International Publication WO2005 / 098213 Pamphlet JP-T 9-505375

  An effective means for suppressing the backflow in the ring fan is to reduce the gap between the ring and the shroud. However, in a construction machine, the ring may come into contact with the shroud due to vibration of the vehicle body or the like, so that it is necessary to widen the gap between the ring and the shroud as compared with a general fan. Therefore, there is a limit to the reduction of the gap. For example, when the fan (ring fan) described in Patent Document 1 is applied to a construction machine, there is a limit to reducing the gap between the ring and the adjustment plate. Due to the limit of the gap reduction, there is a limit to increasing the efficiency of the cooling fan. is there.

  Further, as means for improving the efficiency of the cooling fan other than reducing the gap between the ring and the shroud, a steady flow control blade connected to the shroud in the gap between the ring and the shroud as in the technique described in Patent Document 2. Some arrangements reduce the vortex flow in the recirculation air flow that flows back through the gap between the ring and the shroud. However, this steady flow control blade does not reduce the recirculation air flow itself.

  The present invention has been made to solve the above problems, and its purpose is to suppress the backflow of the gap between the ring and the shroud while there is a limit to the reduction of the gap between the ring and the shroud. It is to provide a cooling fan for construction machinery.

  The present application includes a plurality of means for solving the above-mentioned problems. For example, a cooling fan for a construction machine that is disposed with a gap on the inner peripheral side of the shroud and is spaced apart in the circumferential direction. The plurality of main wings and a ring connecting the outer peripheral side ends of the plurality of main wings, and at least one of the plurality of main wings is wider than between the other wings. The ring has an enlarged diameter portion whose inner and outer diameters increase in the discharge direction of the cooling fan, and the enlarged diameter portion is more than the shroud in the axial direction of the cooling fan. A plurality of blade pieces arranged at intervals in the circumferential direction on the outer peripheral portion of the enlarged diameter portion of the ring, wherein the plurality of blade pieces are Located between wide wings in the ring A plurality of first blades arranged in a first region across a portion corresponding to the position of the front edge of the main wing on the rear side in the rotation direction of the cooling fan, of the two main wings forming the space between the blades And a plurality of second wing pieces arranged outside the first region of the ring, wherein the plurality of first wing pieces are more ring-shaped than the plurality of second wing pieces. It is formed in the shape which relieves the stress which arises in the joint part.

According to the present invention, by disposing the blade piece on the outer peripheral portion of the enlarged diameter portion of the ring, a flow in the direction opposite to the flow that flows backward through the gap between the ring and the shroud is generated. The backflow of the gap between the ring and the shroud can be suppressed while there is a limit to the reduction of the gap. As a result, the fan air volume can be increased and the efficiency can be increased.
Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.

1 is a side view showing a hydraulic excavator to which a first embodiment of a cooling fan for a construction machine according to the present invention is applied. It is sectional drawing which looked at the hydraulic shovel shown in FIG. 1 from the II-II arrow, and is a figure which shows the internal structure in the machine room of a hydraulic shovel. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view showing a first embodiment of a cooling fan for a construction machine according to the present invention and a cooling device including the cooling fan in a partially sectional state. It is the figure which looked at the vicinity of the blade piece part which comprises a part of 1st Embodiment of the cooling fan of the construction machine of this invention from the suction side of the cooling fan. It is explanatory drawing which shows the effect | action of 1st Embodiment of the cooling fan of the construction machine of this invention. It is the perspective view which looked at 1st Embodiment of the cooling fan of the construction machine of this invention from the suction side. It is the front view which looked at 1st Embodiment of the cooling fan of the construction machine of this invention from the suction side. It is explanatory drawing which shows the deformation | transformation state in rotational drive in 1st Embodiment of the cooling fan of the construction machine of this invention. It is the perspective view seen from the suction side shown in the state which expanded a part of 1st Embodiment of the cooling fan of the construction machine of this invention shown with the code | symbol X of FIG. It is the perspective view seen from the suction side shown in the state which expanded a part in 2nd Embodiment of the cooling fan of the construction machine of this invention. It is the perspective view seen from the suction side shown in the state which expanded a part in 3rd Embodiment of the cooling fan of the construction machine of this invention. It is the perspective view seen from the suction side shown in the state which expanded a part in 4th Embodiment of the cooling fan of the construction machine of this invention. It is the perspective view seen from the suction side shown in the state which expanded a part in 5th Embodiment of the cooling fan of the construction machine of this invention. It is the perspective view seen from the suction side shown in the state which expanded a part in 6th Embodiment of the cooling fan of the construction machine of this invention.

  Embodiments of a cooling fan for a construction machine according to the present invention will be described below with reference to the drawings. In the present embodiment, a hydraulic excavator will be described as an example of a construction machine.

  First, the construction of a hydraulic excavator to which the first embodiment of the cooling fan of the construction machine of the present invention is applied will be described with reference to FIGS. FIG. 1 is a side view showing a hydraulic excavator to which a first embodiment of a cooling fan for a construction machine according to the present invention is applied. FIG. 2 is a sectional view of the hydraulic excavator shown in FIG. FIG. 2 is a diagram showing an internal configuration of a machine room of a hydraulic excavator. Here, a description will be given using the direction seen from the operator seated in the driver's seat.

  In FIG. 1, a hydraulic excavator 1 is a self-propelled crawler-type lower traveling body 2, is mounted on the lower traveling body 2 so as to be able to turn, and an upper revolving body 3 that constitutes a vehicle body together with the lower traveling body 2 This is generally composed of a work front 4 provided at the front end portion of the revolving body 3 so as to be able to move up and down.

  The work front 4 is an articulated actuator for performing excavation work and the like, and includes a boom 6, an arm 7, and a bucket 8. The base end side of the boom 6 is rotatably connected to the front end portion of the upper swing body 3. The base end portion of the arm 7 is rotatably connected to the distal end portion of the boom 6. A proximal end portion of the bucket 8 is rotatably connected to the distal end portion of the arm 7. The boom 6, the arm 7 and the bucket 8 are rotated by the boom cylinder 6a, the arm cylinder 7a and the bucket cylinder 8a, respectively.

  The upper swing body 3 includes a swing frame 11 which is a support structure mounted on the lower traveling body 2 so as to be swingable, a cab 12 installed on the left front side of the swing frame 11, and a rear end portion of the swing frame 11. And a machine room 14 disposed between the cab 12 and the counterweight 13. The cab 12 is provided with an operating device for instructing operations of the lower traveling body 2, the work front 4, and the like, a driver's seat where an operator is seated, and the like (both not shown). The counter weight 13 is for balancing the weight of the work front 4.

  As shown in FIG. 2, the machine room 14 houses a number of devices such as an engine 20 as a prime mover, a hydraulic pump 21 driven by the engine 20, a cooling device 30 that cools the engine 20, the hydraulic pump 21, and the like. Yes. Although the details will be described later, the cooling device 30 includes a heat exchange device 31 and a cooling fan 32, and is disposed, for example, on the opposite side of the hydraulic pump 21 with the engine 20 interposed therebetween. The outer wall of the machine room 14 is formed by a building cover 16. A suction port 16 a for taking outside air into the machine room 14 is provided on the cooling device 30 side (left side) of the building cover 16. A discharge port 16 b that discharges air from the machine room 14 is provided on the hydraulic pump 21 side (right side) of the building cover 16.

  Next, a first embodiment of a cooling fan for a construction machine according to the present invention and a configuration of a cooling device including the first embodiment will be described with reference to FIGS. FIG. 3 is a side view showing a first embodiment of a cooling fan for a construction machine according to the present invention and a cooling device including the first embodiment in a partially sectional state, and FIG. 4 is a first view of the first cooling fan for a construction machine according to the present invention. It is the figure which looked at the vicinity of the blade piece part which comprises a part of embodiment from the suction side of the cooling fan. 3 and 4, the same reference numerals as those shown in FIGS. 1 and 2 are the same parts, and detailed description thereof is omitted.

  In FIG. 3, the cooling device 30 includes a heat exchanging device 31, a cooling fan 32 that generates cooling air that cools the heat exchanging device 31, and a shroud 33 that guides the cooling air to the heat exchanging device 31. Yes.

  The heat exchange device 31 is configured by a heat exchanger such as a radiator or an oil cooler, for example. The radiator cools the cooling water of the engine 20, and the oil cooler operates through a hydraulic circuit including the hydraulic cylinders 6a, 7a, 8a (see FIG. 1) and the hydraulic pump 21 (see FIG. 2) of the work front 4. The oil is cooled. The heat exchange device 31 is disposed on the suction side of the cooling fan 32 so as to face the cooling fan 32.

  A rotating shaft 23 is attached to the cooling fan 32. The rotation shaft 23 is rotatably supported by the engine 20 above the drive shaft (output shaft) 20a of the engine 20. Pulleys 24 and 25 are provided on the rotary shaft 23 and the drive shaft 20a of the engine 20, respectively. A belt 26 is stretched between the pulley 24 on the rotary shaft 23 side and the pulley 25 on the drive shaft 20a side. With this configuration, the engine 20 functions as a drive device that rotationally drives the cooling fan 32. The pulleys 24 and 25 and the belt 26 function as a power transmission mechanism that transmits the power of the engine 20 to the cooling fan 32.

  A shroud 33 is fixed to the cooling fan 32 side (right side in FIG. 3) of the heat exchange device 31. The shroud 33 includes a cylindrical portion 35 that extends in the axial direction of the cooling fan 32 and an overhang portion 36 that protrudes radially inward from the entire periphery of the end portion of the cylindrical portion 35 on the cooling fan 32 side. A part of the outer edge of the cooling fan 32 is surrounded. An inner peripheral edge 36 a of the overhang portion 36 forms a circular opening and faces the outer edge of the cooling fan 32 with a gap d <b> 1.

  The cooling fan 32 is a so-called ring fan, and includes a boss 41 to which the rotary shaft 23 is attached, a plurality of main wings 42 for air blowing and pressure increase at an outer peripheral portion of the boss 41 and spaced apart in the circumferential direction, and a plurality of And a ring 43 for connecting the outer peripheral side end portion 42a of the main wing 42. The cooling fan 32 is made of, for example, resin, and a boss 41, a main wing 42, and a ring 43 are integrally formed.

  The ring 43 has a cylindrical shape whose discharge side widens toward the end. In other words, the ring 43 has an inner diameter and an outer diameter that are substantially equal to the outer diameter of the main wing 42, and a ring main body 45 that contacts the outer peripheral end 42a of the main wing 42, and a discharge side end of the ring main body 45 (FIG. 3). Then, it is comprised by the enlarged diameter part 46 from which an internal diameter and an outer diameter expand gradually toward a discharge direction (right direction in FIG. 3) from a right end part. The ring body 45 has a suction side end positioned on the suction side of the front edge 42b of the main wing 42, and a discharge side end (right end in FIG. 3) of the main wing 42 more than the rear edge 42c. It is configured to be located on the discharge side. That is, the ring main body 45 is configured such that the entire outer peripheral side end 42 a of the main wing 42 is disposed inside the ring main body 45. On the outer peripheral side of the ring main body 45, the inner peripheral edge 36a of the overhang portion 36 of the shroud 33 is disposed with a gap d1. The enlarged diameter portion 46 is located on the discharge side of the overhang portion 36 of the shroud 33 in the axial direction of the cooling fan 32, and has a trumpet shape that expands in diameter from the suction side toward the discharge side. ing. The ring 43 is composed of a cylindrical member having a substantially constant plate thickness, and the outer diameter of the ring 43 changes in the same manner as the inner diameter.

  On the outer peripheral surface of the diameter-expanded portion 46 of the ring 43, a plurality of blade piece portions 50 having a blade action protruding outward are provided at intervals in the entire circumferential direction. The blade piece 50 has the same size as the difference between the maximum diameter and the minimum diameter of the enlarged diameter portion 46 of the ring 43 and the size of the gap d1 between the ring 43 and the shroud 33, and the main wing 42 that generates cooling air. Is extremely small compared to The blade piece 50 is disposed at a distance d2 on the discharge side with respect to the protruding portion 36 of the shroud 33 in the axial direction of the cooling fan 32. The blade piece 50 is, for example, a substantially fan-shaped plate member, and the blade leading edge 50 b is substantially parallel to the radial direction of the cooling fan 32, and the blade trailing edge 50 c is substantially parallel to the axial direction of the cooling fan 32. It is configured. That is, the blade leading edge 50 b is an axial suction side end (left end in FIG. 3), and the blade trailing edge 50 c is an outer peripheral end of the blade piece 50. For example, the outer peripheral end 50 c of the blade piece 50 is located radially inward of the outer peripheral end of the enlarged diameter portion 46. Further, as shown in FIG. 4, the blade piece 50 is configured to tilt backward with respect to the rotation direction of the cooling fan 32. That is, the blade portion 50 is inclined so that the outer peripheral end 50c of the blade leading edge 50b is located behind the root portion (the connecting portion with the enlarged diameter portion 46 of the ring 43) 50a in the rotation direction of the cooling fan 32. doing. As shown in FIG. 3, these blade pieces 50 rotate integrally with the main wing 42 and the ring 43.

  Next, the operation of the first embodiment of the cooling fan of the construction machine according to the present invention will be described with reference to FIGS. FIG. 5 is an explanatory view showing the operation of the first embodiment of the cooling fan of the construction machine according to the present invention. In FIG. 2, the thick arrow indicates the flow of cooling air. In FIG. 5, the same reference numerals as those shown in FIGS. 1 to 4 are the same parts, and detailed description thereof is omitted.

  When the cooling fan 32 shown in FIG. 2 is driven by the engine 20, outside air is sucked from the suction port 16 a of the building cover 16 of the machine room 14, and cooling air is generated in the machine room 14. The cooling air is discharged from the cooling fan 32 via the shroud 33 after cooling the heat exchange device 31 in the machine room 14. The cooling air discharged from the cooling fan 32 cools the periphery of the engine 20 and the hydraulic pump 21, and then is discharged to the outside from the discharge port 16 b of the building cover 16. Thus, since the heat exchange device 31 and other devices housed in the machine room 14 are cooled by the cooling air generated by the cooling fan 32, they can be operated normally.

  In the cooling fan 32 shown in FIG. 5, the main flow α flows from the suction side to the discharge side of the cooling fan 32 due to the rotation of the main blade 42, and a pressure difference is generated between the suction side and the discharge side. Due to this pressure difference, air flows in the direction opposite to the main flow α from the discharge side of the overhanging portion 36 of the shroud 33 disposed on the outer peripheral side of the ring 43 toward the gap d1 between the ring 43 and the overhanging portion 36. (Backflow) β occurs. This reverse flow β causes a decrease in the air volume and efficiency of the cooling fan 32.

  In the present embodiment, the blade piece 50 provided on the ring 43 rotates integrally with the main wing 42, thereby generating a radially outward flow γ on the outer peripheral side of the ring 43. This flow γ is a flow opposite to the reverse flow β flowing between the ring 43 and the shroud 33. Since the reverse flow β is hindered by the flow γ in the opposite direction, the flow rate of the reverse flow β flowing through the gap d1 between the ring 43 and the overhanging portion 36 of the shroud 33 is reduced as compared with the configuration without the blade piece 50. Is done. Therefore, the efficiency of the cooling fan 32 can be increased by the amount that the flow rate of the backflow β is reduced.

  Further, in the present embodiment, since the blade piece 50 provided on the outer peripheral surface of the enlarged diameter portion 46 of the ring 43 has a shape having a blade action, the blade piece 50 rotates integrally with the main wing 42. By doing so, it itself exerts a boosting action. Therefore, the effective fan outer diameter of the cooling fan 32 is determined by the position of the outer peripheral end 50c of the blade piece 50, and becomes D2 shown in FIG. On the other hand, the effective fan outer diameter of the cooling fan configured without the blade piece 50 is determined by the position of the outer peripheral end 42a of the main wing 42, and is D1 shown in FIG. In other words, the effective fan outer diameter of the cooling fan 32 of the present embodiment is larger by the blade piece 50 than D1 in the case of a cooling fan having no blade piece 50, and increases to D2. The effective work performed on the air of the cooling fan 32, that is, the total pressure increase, is proportional to the square of the fan outer diameter. Therefore, in the cooling fan 32 of the present embodiment, the air volume increases at the same number of rotations as compared to the case of the cooling fan having no blade piece 50.

  In addition, in the present embodiment, the blade piece portion 50 is inclined so that the outer peripheral end 50c of the blade leading edge 50b of the blade piece portion 50 is located behind the root portion 50a in the rotation direction of the cooling fan 32. (See FIG. 4). In the case of this configuration, it has been confirmed that the static pressure efficiency of the fan is increased as compared with the case where the blade piece portion 50 is not inclined.

  In the present embodiment, the ring 43 is configured such that the inner diameter and outer diameter on the discharge side of the ring 43 are increased. In this case, the flow on the outer peripheral side of the main flow α discharged from the main wing 42 spreads smoothly outward in the radial direction along the inner peripheral surface of the diameter-expanded portion 46 of the ring 43, so that the discharge side of the ring 43 is expanded in diameter. The generation of vortices around the discharge side end of the ring 43 is reduced as compared with the case where the same diameter is used instead. Since the generation of the vortex is reduced, the efficiency of the cooling fan 32 is increased.

  Thus, in the present embodiment, the effect of increasing the air volume and improving the efficiency of the cooling fan 32 can be obtained without reducing the gap d1 between the ring 43 and the shroud 33. By increasing the air volume of the cooling fan 32, the temperature rise of various devices such as the heat exchange device 31 in the machine room 14 can be suppressed, and the reliability of the hydraulic excavator 1 is improved. Further, since the power consumption can be reduced by improving the efficiency of the cooling fan 32, energy saving of the hydraulic excavator 1 can be realized.

  By the way, in construction machines, in order to ensure the comfort of the operator, it is required to suppress the peak sound generated from the cooling fan 32, that is, the noise at the so-called blade passing frequency. Therefore, in the present embodiment, the plurality of main blades 42 of the cooling fan 32 are arranged at unequal pitches (different intervals) in the rotation direction.

  Next, the arrangement of the main wings of the cooling fan will be described with reference to FIGS. 6 is a perspective view of the first embodiment of the cooling fan for the construction machine according to the present invention as viewed from the suction side, and FIG. 7 is the first embodiment of the cooling fan for the construction machine according to the present invention indicated by the symbol X in FIG. It is the perspective view seen from the suction side shown in the state where a part of form was expanded. 6 and 7, the same reference numerals as those shown in FIGS. 1 to 5 are the same parts, and the detailed description thereof will be omitted.

  6 and 7, the cooling fan 32 has, for example, seven main wings 42, and these main wings 42 are arranged at different intervals in the rotation direction. That is, between the blades of the seven main wings 42, a relatively wide wing (hereinafter sometimes referred to as the first wing) P1 and a relatively narrow wing (hereinafter referred to as the second wing). P2 exists. In the present embodiment, for example, the main wings 42 are arranged so that there are two relatively wide blade spacings P1 as compared to other blades. The cooling fan 32 has, for example, 62 blade pieces 50. These blade pieces 50 are, for example, arranged at equal pitches (same intervals) in the rotation direction.

  When the main wings 42 are arranged at unequal pitches in this way, when the cooling fan 32 is in operation, the portion of the ring 43 that is located in the relatively wide blade interval P1 is positioned in the other blade interval (relatively narrow blade interval) P2. It may be deformed to be larger than the part to be.

  Next, the result of deformation analysis of the cooling fan in which the main wings are arranged at unequal pitches will be described with reference to FIG. FIG. 8 is an explanatory view showing a deformation state during rotation driving in the first embodiment of the cooling fan of the construction machine of the present invention, and is a front view seen from the suction side of the cooling fan. The cooling fan in FIG. 8 shows an extremely deformed state. In FIG. 8, the same reference numerals as those shown in FIGS. 1 to 7 are the same parts, and detailed description thereof is omitted.

  From the result of the deformation analysis shown in FIG. 8, it can be seen that the deformation of the portion of the ring 43 located in the first inter-blade P1 is larger than the deformation of the portion located in the second inter-blade P2. More specifically, at the suction side end of the ring main body 45 of the ring 43, the portion located in the first inter-blade P1 is particularly greatly deformed radially inward. On the other hand, among the main wings 42 (Wf) and 42 (Wr) forming the first inter-blade P1, the predetermined includes the front edge 42b (Wr) of the main wing 42 (Wr) located on the rear side in the rotation direction of the cooling fan 32. The portion located in the region is greatly deformed radially outward.

  According to the result of this deformation analysis, when the blade piece 50 provided in the enlarged diameter portion 46 of the ring 43 receives a centrifugal force radially outward, the joint (root portion) of the blade piece 50 with the deformed ring 43. The local stress generated at the time increases. In the blade piece portion 50 disposed in the enlarged diameter portion 46 of the ring 43 in a portion corresponding to a predetermined region straddling the leading edge 42b (Wr) of the main wing 42 (Wr) where deformation is particularly large, the joint portion with the ring 43 In particular, the local stress generated in the case becomes large.

  In this way, in order to reduce the noise of the cooling fan 32 while increasing the air volume and increasing the efficiency of the cooling fan 32, the blade piece 50 is disposed on the outer peripheral portion of the enlarged diameter portion 46 of the ring 43, and a plurality of the blade pieces 50 are arranged. When the main wings 42 are arranged at unequal pitches, the above-described problems occur. Therefore, in the present embodiment, the blade piece 50 where the local stress is particularly large is configured to have a shape that relaxes the stress generated in the joint portion with the ring 43.

  Next, the configuration and structure of the plurality of blade pieces will be described with reference to FIGS. FIG. 9 is a perspective view seen from the suction side, showing a part of the first embodiment of the cooling fan of the construction machine of the present invention indicated by the symbol X in FIG. 7 in an enlarged state. In FIG. 9, the same reference numerals as those shown in FIGS. 1 to 8 are the same parts, and detailed description thereof is omitted.

  7 and 9, the plurality of blade pieces 50 are portions of the ring 43 that are located at a relatively wide blade interval P1 and form two main blades 42 (Wf), 42 (Wr) that form the blade interval P1. ) Of the main wing 42 (Wr) on the rear side in the rotation direction of the cooling fan 32 in a predetermined region (hereinafter referred to as a first region) R1 across a portion corresponding to the position of the front edge 42b (Wr). It comprises a plurality of first blade pieces 51 and a plurality of second blade pieces 52 arranged outside the first region. In the present embodiment, there are two first regions R1, and the number of first blade pieces 51 disposed in each first region R1 is, for example, four. This first region R1 is a region having a particularly large local stress found by the above-described deformation analysis of the cooling fan, and depends on conditions such as the diameter of the ring 43, the size of the blade P1, the size of the enlarged diameter portion 46, and the like. The range is determined.

  The first blade piece portion 51 is formed in a shape that relieves stress generated at the joint portion with the ring 43 as compared with the second blade piece portion 52. Specifically, as shown in FIG. 9, the first blade piece 51 includes a corner (joint portion) between the side surface on the rotation direction side and the enlarged diameter portion 46 of the ring 43, and a side surface on the counter-rotation direction side and the ring. 43 has a rotation-side fillet portion 51a and a counter-rotation-side fillet portion 51b at corners (joining portions) with the diameter-expanded portion 46, respectively. Similarly, the second blade piece 52 includes a corner (joint portion) between the side surface on the rotation direction side and the enlarged diameter portion 46 of the ring 43 and a corner between the side surface on the counter rotation direction side and the diameter enlarged portion 46 of the ring 43. Each part (joint part) has a rotation side fillet part 52a and a counter rotation side fillet part 52b. The counter-rotation side fillet portion 51 b of the first wing piece portion 51 is set to be relatively larger than the counter-rotation side fillet portion 52 b of the second wing piece portion 52. On the other hand, the rotation-side fillet portion 51 a of the first blade piece 51 is set to be approximately the same size as the rotation-side fillet portion 52 a of the second blade piece 52.

  In the present embodiment, a fillet portion 51b that is relatively larger than the fillet portion 52b of the second wing piece portion 52 is provided with respect to the coupling portion (root portion) of the first wing piece portion 51 with the ring 43. Therefore, the suppression effect of the local stress produced in the joint part (root part) of the 1st blade piece part 51 can be exhibited.

  As described above, according to the first embodiment of the cooling fan for the construction machine of the present invention, the ring piece 50 and the shroud 33 are arranged by arranging the blade piece 50 on the outer peripheral portion of the enlarged diameter portion 46 of the ring 43. Since a flow γ opposite to the flow β flowing backward through the gap d1 between the ring 43 and the shroud 33 is generated, the reduction of the gap d1 between the ring 43 and the shroud 33 is limited. Backflow β can be suppressed. As a result, the fan air volume can be increased and the efficiency can be increased.

  Further, according to the present embodiment, since the plurality of main wings 42 are arranged at unequal pitches, fan noise can be reduced.

  Furthermore, according to the present embodiment, among the plurality of blade pieces 50, the first blade piece 51 arranged in the first region R1 that is greatly affected by the increased deformation of the ring 43 due to the unequal pitch of the main wing 42 is provided. Since the second blade piece 52 arranged outside the first region has a shape that relieves stress generated in the joint portion with the ring 43 rather than the second blade piece portion 52, the joint portion with the ring 43 in the first blade portion 51. It is possible to further reduce the local stress generated in the (root portion).

  That is, according to the present embodiment, the noise of the cooling fan 32 can be reduced and the local stress generated in the blade piece 50 can be reduced while maintaining the increase in air volume and high efficiency of the cooling fan 32.

  Further, according to the present embodiment, the fillet portion 51b of the first wing piece portion 51 arranged in the first region R1 is larger than the fillet portion 52b of the second wing piece portion 52 arranged outside the first region. Therefore, the material for molding the cooling fan 32 can be used as compared with the case where both the fillet portions of the first blade piece portion 51 and the second blade piece portion 52 are made the same size as the fillet portion of the first blade piece portion 51. Can be used, and as a result, the manufacturing cost can be reduced.

  Further, according to the present embodiment, the first blade piece 51 and the second blade piece 52 constituting the blade piece 50 are configured to be inclined backward with respect to the rotation direction of the cooling fan 32, and the first Since the fillet portion 52b is provided at the root portion on the side opposite to the rotation direction of the first blade piece 51 and the second blade piece 52, the first blade piece 51 tilted backward and the efficiency of the fan are further increased. The stress generated in the joint portion between the second blade piece 52 and the enlarged diameter portion 46 of the ring 43 can be relaxed.

  Next, a second embodiment of the cooling fan of the construction machine according to the present invention will be described with reference to FIG. FIG. 10 is a perspective view seen from the suction side, showing a part of the cooling fan of the construction machine according to the second embodiment of the present invention in an enlarged state. In FIG. 10, the same reference numerals as those shown in FIGS. 1 to 9 are the same parts, and detailed description thereof is omitted.

  The second embodiment of the cooling fan for the construction machine according to the present invention is different from the first embodiment as follows. In the cooling fan 32 according to the first embodiment, out of the plurality of blade pieces 50, the counter-rotation side fillet portion 51b of the first blade piece portion 51 arranged in the first region R1 is arranged outside the first region. The second blade piece 52 is relatively larger than the counter-rotation side fillet 52b (see FIG. 9). On the other hand, in the cooling fan 32A according to the second embodiment shown in FIG. 10, the thickness of the first blade piece portion 51A arranged in the first region R1 out of the plurality of blade piece portions 50A is outside the first region. Is relatively thinner than the thickness of the second blade piece 52 </ b> A disposed on the surface. Moreover, although the 1st blade piece part 51A and the 2nd blade piece part 52A of this Embodiment are not provided with the fillet part in the root part, the structure provided with a fillet part is also possible.

  In the present embodiment, the thickness of the first blade piece 51A arranged in the first region R1 is thinner than the thickness of the second blade piece 52A arranged outside the first region. The mass of the portion 51A is smaller than the mass of the second blade piece 52A. Therefore, the centrifugal force acting on the first wing piece portion 51A is smaller than the centrifugal force acting on the second wing piece portion 52A, and accordingly, the first blade piece portion 51A and the enlarged diameter portion 46 of the ring 43 in the first blade piece portion 51A. It is possible to reduce the local stress generated in the coupling part (root part).

  According to the second embodiment of the cooling fan of the construction machine of the present invention described above, the same effect as that of the first embodiment described above can be obtained.

  Further, according to the present embodiment, the amount of the material used to form the cooling fan 32A can be reduced by the amount that the thickness of the first blade piece portion 51A is made thinner than the thickness of the second blade piece portion 52A. The manufacturing cost can be reduced.

  Next, a third embodiment of the cooling fan for the construction machine according to the present invention will be described with reference to FIG. FIG. 11 is a perspective view seen from the suction side showing a part of the cooling fan of the construction machine according to the third embodiment of the present invention in an enlarged state. In FIG. 11, the same reference numerals as those shown in FIGS. 1 to 10 are the same parts, and detailed description thereof is omitted.

  The third embodiment of the cooling fan for the construction machine of the present invention is different from the second embodiment as follows. The cooling fan 32A according to the second embodiment includes a second blade piece portion in which the thickness of the first blade piece portion 51A arranged in the first region R1 is arranged outside the first region among the plurality of blade piece portions 50A. The thickness is relatively smaller than the thickness of 52A (see FIG. 10). On the other hand, the cooling fan 32B according to the third embodiment shown in FIG. 11 has the axial length of the first blade piece 51B arranged in the first region R1 among the plurality of blade pieces 50B. The second blade piece 52A arranged outside the first region is relatively shorter than the axial length.

  In the present embodiment, the axial length of the first blade piece 51B arranged in the first region R1 is relatively shorter than the axial length of the second blade piece 52A arranged outside the first region. Therefore, the mass of the first blade piece 51B is smaller than that of the second blade piece 52A. Therefore, as in the case of the second embodiment, the centrifugal force acting on the first wing piece portion 51B is smaller than the centrifugal force acting on the second wing piece portion 52A, and accordingly, the first wing piece portion. The local stress which arises in the joint part (root part) with the enlarged diameter part 46 of the ring 43 in 51B can be reduced.

  According to the third embodiment of the cooling fan of the construction machine of the present invention described above, the same effect as in the second embodiment described above can be obtained.

  Next, a fourth embodiment of the cooling fan for the construction machine according to the present invention will be described with reference to FIG. FIG. 12 is a perspective view seen from the suction side showing a part of the cooling fan of the construction machine according to the fourth embodiment of the present invention in an enlarged state. In FIG. 12, the same reference numerals as those shown in FIGS. 1 to 11 are the same parts, and detailed description thereof is omitted.

  The fourth embodiment of the cooling fan of the construction machine of the present invention is different from the third embodiment as follows. In the cooling fan 32B according to the third embodiment, among the plurality of blade pieces 50B, the axial length of the first blade piece 51B arranged in the first region R1 is arranged outside the first region. The two blade pieces 52A are relatively shorter than the axial length (see FIG. 11). On the other hand, the cooling fan 32C according to the fourth embodiment shown in FIG. 12 has the radial length of the first blade piece 51C arranged in the first region R1 among the plurality of blade pieces 50C. The second blade piece 52A disposed outside the first region is relatively shorter than the length in the radial direction.

  In the present embodiment, the radial length of the first blade piece portion 51C arranged in the first region R1 is relatively shorter than the radial length of the second blade piece portion 52A arranged outside the first region. Therefore, the mass of the first blade piece 51C is correspondingly smaller than the mass of the second blade piece 52A. Therefore, as in the case of the third embodiment, the centrifugal force acting on the first wing piece portion 51C is smaller than the centrifugal force acting on the second wing piece portion 52A, and accordingly, the first wing piece portion. It is possible to reduce the local stress generated in the joint portion (root portion) with the enlarged diameter portion 46 of the ring 43 in 51C.

  Further, the rotation speed of the first blade piece 51C is smaller than the rotation speed of the second blade piece 52A because the length in the radial direction is relatively short. Accordingly, the acting centrifugal force is smaller than in the case of the third embodiment. Therefore, the centrifugal force acting on the first wing piece portion 51C is smaller than the centrifugal force acting on the second wing piece portion 52A, and accordingly, the first blade piece portion 51C is coupled to the enlarged diameter portion 46 of the ring 43. The local stress generated in the part (root part) can be reduced.

  According to the fourth embodiment of the cooling fan of the construction machine of the present invention described above, the same effect as that of the third embodiment described above can be obtained.

  Next, a fifth embodiment of the cooling fan for the construction machine according to the present invention will be described with reference to FIG. FIG. 13: is the perspective view seen from the suction side shown in the state which expanded a part in 5th Embodiment of the cooling fan of the construction machine of this invention. In FIG. 13, the same reference numerals as those shown in FIGS. 1 to 12 are the same parts, and detailed description thereof is omitted.

  The fifth embodiment of the cooling fan for the construction machine of the present invention is different from the first embodiment as follows. In the cooling fan 32 according to the first embodiment, out of the plurality of blade pieces 50, the counter-rotation side fillet portion 51b of the first blade piece portion 51 arranged in the first region R1 is arranged outside the first region. The second blade piece 52 is relatively larger than the counter-rotation side fillet 52b (see FIG. 9). On the other hand, the cooling fan 32D according to the fifth embodiment shown in FIG. 13 has a configuration in which the first blade piece portion 51D arranged in the first region R1 among the plurality of blade piece portions 50D is connected by the rib 54. The second blade piece 52 arranged outside the first region is configured without a rib.

  Specifically, each of the plurality of first blade pieces 51D arranged in the first region R1 has a rib 54 at the suction side end in the axial direction. The rib 54 extends in the circumferential direction and connects the plurality of first blade pieces 51D. The length in the radial direction of the rib 54 is substantially the same as the length in the radial direction of the suction side end of the first blade piece 51D. The function of the rib 54 can reduce local stress generated in the coupling portion (root portion) of the first blade piece 51D with the enlarged diameter portion 46 of the ring 43.

  According to the fifth embodiment of the cooling fan of the construction machine of the present invention described above, the same effect as in the first embodiment described above can be obtained.

  In addition, according to the present embodiment, since the first blade piece 51D is provided with the rib 54, the rigidity of the first blade piece 51D can be increased as compared with the case of the first embodiment. Furthermore, since the rib 54 is provided so as to connect the plurality of first blade pieces 51D, the rigidity of the first blade piece 51D can be further increased.

  Next, a sixth embodiment of the cooling fan for the construction machine according to the present invention will be described with reference to FIG. FIG. 14 is a perspective view seen from the suction side showing a part of the cooling fan of the construction machine according to the sixth embodiment of the present invention in an enlarged state. In FIG. 14, the same reference numerals as those shown in FIGS. 1 to 13 are the same parts, and detailed description thereof is omitted.

  The sixth embodiment of the cooling fan for the construction machine of the present invention shown in FIG. 14 is different from the first embodiment in that a plurality of blade pieces 50E are arranged in the first region R1. Instead of the first wing piece portion 51 and a plurality of second wing piece portions 52 arranged outside the first region, the second wing piece portion 52 is constituted only by the second wing piece portion 52 arranged outside the first region. is there. That is, the plurality of blade pieces 50E are not disposed in the first region R1, but are disposed in the entire circumferential region of the ring 43 except for the first region R1. In this case, since the blade piece (first blade piece) is not arranged in the first region R1 where the increase in local stress is a concern, there is no need to worry about the increase in the local stress in the blade piece.

  According to the sixth embodiment of the cooling fan of the construction machine of the present invention described above, the same effect as that of the first embodiment described above can be obtained.

  In addition, according to the present embodiment, the amount of the material for forming the cooling fan 32E can be reduced by the amount that the blade piece 50E is not disposed in the first region R1, and as a result, the manufacturing cost can be reduced. .

  The present invention is not limited to the present embodiment, and includes various modifications. The above-described embodiment has been described in detail for easy understanding of the present invention, and is not necessarily limited to the one having all the configurations described. A part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Moreover, it is also possible to add, delete, or replace another configuration for a part of the configuration of each embodiment.

  For example, in the above-described first to sixth embodiments of the construction machine of the present invention, the example in which the cooling fan of the construction machine of the present invention is applied to the hydraulic excavator 1 is shown. It can be widely applied to various construction machines such as wheel loaders.

  In the above-described embodiment, the example in which the engine 20 is used as the driving device for the cooling fan 32 has been described. However, an electric motor, a hydraulic motor, or the like can be used as the driving device.

  Further, in the above-described embodiment, the example in which the seven main blades 42 of the cooling fan 32 are arranged so that there are two relatively wide blade spaces P1 as compared with the space between the other blades is shown. However, it is possible to obtain an effect of reducing fan noise by arranging the main wings so that an arbitrary number of main wings are relatively wider between at least one wing than between other wings. There may also be a relative width in the relatively wide plurality of blades P1 and in the relatively narrow plurality of blades P2. That is, it is possible to arrange the main wings so that the plurality of wings are all different.

  In the above-described embodiment, the example in which the ring main body portion 45 is configured so that the entire outer peripheral end portion 42a of the main wing 42 is disposed inside the ring main body portion 45 of the ring 43 has been shown. The shape of the main body is not limited to this. For example, the ring main body portion can be configured such that the suction side end portion of the ring main body portion is located on the discharge side with respect to the front edge 42b of the main wing 42. Further, the ring main body portion can be configured such that the discharge side end portion of the ring main body portion is located on the suction side with respect to the rear edge 42c of the main wing 42.

  In the above-described embodiment, the blade piece 50 is configured such that the blade leading edge 50 b is substantially parallel to the radial direction of the cooling fan 32 and the blade trailing edge 50 c is substantially parallel to the axial direction of the cooling fan 32. Although an example of a substantially sector shape has been shown, the shape of the wing piece portion may be a shape having a wing action.

  In the above-described embodiment, the example of the resin cooling fan 32 in which the boss 41, the main wing 42, the ring 43, and the blade piece 50 are integrally formed is shown. However, the boss 41, the main wing 42, the ring 43, It is also possible to form a cooling fan by manufacturing the blade piece parts 50 separately and then joining the members.

  In the second to fourth embodiments described above, the thickness, axial length, and radial length of the first blade pieces 51A, 51B, 51C arranged in the first region R1 are set to the first. The centrifugal force acting on the first blade pieces 51A, 51B, and 51C is made relatively smaller than the thickness, axial length, and radial length of the second blade pieces 52A arranged outside one region. An example is shown in which the force is smaller than the centrifugal force acting on the second blade piece 52A. However, the centrifugal force that acts on the first blade piece is applied to the second blade piece by configuring the first blade piece in a shape other than the above in which the mass is smaller than that of the second blade piece. It is also possible to make it smaller than the force.

  DESCRIPTION OF SYMBOLS 1 ... Hydraulic excavator (construction machine), 32, 32A, 32B, 32C, 32D, 32E ... Cooling fan, 33 ... Shroud, 42 ... Main wing, 43 ... Ring, 46 ... Diameter expansion part, 50, 50A, 50B, 50C, 50D, 50E: Wings, 51, 51A, 51B, 51C, 51D ... First wings, 52, 52A ... Second wings, 51b ... Anti-rotation side fillet (fillet), 52b ... Anti-rotation Side fillet (fillet), 54 ... rib

Claims (9)

A cooling fan for a construction machine arranged with a gap on the inner periphery side of the shroud,
A plurality of main wings arranged at intervals in the circumferential direction;
A ring connecting the outer peripheral side ends of the plurality of main wings,
The plurality of main wings are arranged such that at least one of the wings is wider than the other wings,
The ring has an enlarged diameter portion whose inner diameter and outer diameter expand toward the discharge direction of the cooling fan, and the enlarged diameter portion is closer to the discharge side of the cooling fan than the shroud in the axial direction of the cooling fan. Arranged to be located,
A plurality of blade pieces arranged at intervals in the circumferential direction on the outer peripheral portion of the enlarged diameter portion of the ring;
The plurality of blade pieces are portions located between wide blades in the ring, and are located at the position of the leading edge of the main blade on the rear side in the rotation direction of the cooling fan among the two main blades forming the space between the blades. It is composed of a plurality of first wing pieces arranged in a first region across a corresponding part, and a plurality of second wing pieces arranged outside the first region of the ring,
The cooling fan for a construction machine, wherein the plurality of first blade pieces are formed in a shape that relieves stress generated at a joint with the ring, rather than the plurality of second blade pieces. In the cooling fan of the construction machine according to claim 1,
The first wing piece part and the second wing piece part each have a fillet part at the root part,
The cooling fan for a construction machine, wherein the first blade piece portion is configured such that a fillet portion thereof is larger than the fillet portion of the second blade piece portion. In the cooling fan of the construction machine according to claim 2,
The first blade piece and the second blade piece are configured to tilt backward with respect to the rotation direction of the cooling fan,
The fillet part of the first wing piece part and the fillet part of the second wing piece part are respectively disposed on the side surface on the counter-rotation direction side of the first wing piece part and on the counter-rotation direction side of the second wing piece part. A cooling fan for a construction machine, characterized by being provided on a side surface. In the cooling fan of the construction machine according to claim 1,
The cooling blade for a construction machine, wherein the first blade piece is formed in a shape having a smaller mass than the second blade piece. In the cooling fan of the construction machine according to claim 4,
The cooling fan for a construction machine, wherein the first blade piece portion is configured to have a thickness smaller than that of the second blade piece portion. In the cooling fan of the construction machine according to claim 4,
The construction machine characterized in that the first wing piece portion is configured to have a shorter radial length than the second wing piece portion. In the cooling fan of the construction machine according to claim 4,
The construction machine characterized in that the first wing piece portion is configured to have a shorter axial length than the second wing piece portion. In the cooling fan of the construction machine according to claim 1,
A construction machine comprising a rib connecting the plurality of first blade pieces. A cooling fan for a construction machine arranged with a gap on the inner periphery side of the shroud,
A plurality of main wings arranged at intervals in the circumferential direction;
A ring connecting the outer peripheral side ends of the plurality of main wings,
The plurality of main wings are arranged such that at least one of the wings is wider than the other wings,
The ring has an enlarged diameter portion whose inner diameter and outer diameter expand toward the discharge direction of the cooling fan, and the enlarged diameter portion is closer to the discharge side of the cooling fan than the shroud in the axial direction of the cooling fan. Arranged to be located,
A plurality of blade pieces arranged at intervals in the circumferential direction on the outer peripheral portion of the enlarged diameter portion of the ring;
The plurality of blade pieces are portions located between wide blades in the ring, and are located at the position of the leading edge of the main blade on the rear side in the rotation direction of the cooling fan among the two main blades forming the space between the blades. A cooling fan for a construction machine, characterized in that the cooling fan is arranged in the entire circumferential direction of the ring except for a region straddling a corresponding portion.

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