JP5242447B2 - Refrigerator and work machine - Google Patents

Description

  The present invention relates to a cooling device and a work machine.

  Conventionally, a cooling system mounted on a work machine such as a construction machine mainly includes a radiator and a cooling fan. A radiator circulates a cooling medium between engines, and cools a cooling medium with external air. The cooling fan generates an air flow through the radiator to facilitate heat exchange with the radiator. Furthermore, a fan shroud that guides the flow of air from the radiator to the cooling fan is provided between the radiator and the cooling fan (see, for example, Patent Document 1).

  In recent years, there has been a problem that the water temperature of the radiator rises due to an increase in the total heat quantity of the engine. In order to solve the problem, for example, it is conceivable to increase the flow rate of air by the cooling fan by increasing the rotation speed of the cooling fan. However, when the rotation speed of the cooling fan is increased, there is a problem that noise increases.

  Therefore, even if the cooling capacity of the engine cooling system is improved, it is necessary to increase the air flow rate of the cooling fan without increasing the rotation speed of the cooling fan. Therefore, in the fan shroud described in Patent Document 1 described above, two cylindrical portions are provided at the tip of the fan shroud. Thereby, the backflow of the air by a fan shroud is prevented, and the flow volume of the air by a cooling fan can be increased.

JP 2006-132380 A

  However, only the structure of the fan shroud described in Patent Document 1 has a limit in increasing the air flow rate by the cooling fan, and further increase in the air flow rate is desired.

  An object of the present invention is to provide a cooling device and a work machine that can sufficiently increase the flow rate of air from a cooling fan without increasing the rotational speed of the cooling fan.

A cooling device according to a first aspect of the present invention includes a cooling fan, a fan shroud, and a ring portion. The fan shroud is provided on the outer peripheral side of the cooling fan. The ring portion has an inner peripheral wall portion, an outer peripheral wall portion, and a bottom portion, and is provided on the fan shroud. The inner peripheral wall portion is provided so as to cover the outer peripheral side of the cooling fan, and has a circular tubular shape. The outer peripheral wall portion is disposed so as to surround the outer peripheral side of the inner peripheral wall portion, and has a circular tubular shape. The bottom is located upstream of the tip of the outer peripheral wall and the tip of the inner peripheral wall in the air flow direction by the cooling fan, and is provided between the inner peripheral wall and the outer peripheral wall. And the space | interval of the outer peripheral surface of an inner peripheral wall part and the inner peripheral surface of an outer peripheral wall part is gradually spreading toward the front end side of an inner peripheral wall part and an outer peripheral wall part from the bottom part side. A taper is provided on the outer peripheral surface of the inner peripheral wall portion so that the outer peripheral surface is reduced in diameter toward the distal end side. A taper is provided on the inner peripheral surface of the inner peripheral wall portion so that the inner peripheral surface is reduced in diameter toward the distal end side. The taper angle of the inner peripheral surface of the inner peripheral wall portion is smaller than the taper angle of the outer peripheral surface of the inner peripheral wall portion.

  In this cooling device, the space between the inner peripheral wall portion and the outer peripheral wall portion of the ring portion has a shape that gradually expands from the bottom side toward the tip side. By arranging the space having such a shape between the inner peripheral wall portion and the outer peripheral wall portion, the flow rate of air by the cooling fan can be sufficiently increased.

  Further, by providing a taper on the outer peripheral surface of the inner peripheral wall portion, the space between the inner peripheral wall portion and the outer peripheral wall portion of the ring portion has the shape as described above.

  Further, by providing the taper as described above on the inner peripheral surface of the inner peripheral wall portion, the ring portion can be easily manufactured using a pair of molds.

  Furthermore, since the taper angle of the inner peripheral surface of the inner peripheral wall portion is small, even if a taper is provided on the inner peripheral surface of the inner peripheral wall portion, the expansion of the chip clearance between the inner peripheral surface of the inner peripheral wall portion and the cooling fan is suppressed. be able to. Thereby, the fall of the flow rate of the air by a cooling fan can be suppressed.

  The cooling device according to the second invention is the cooling device according to the first invention, wherein the inner peripheral surface of the outer peripheral wall portion is provided with a taper so that the inner peripheral surface increases in diameter toward the tip side.

  In this cooling device, by providing a taper on the inner peripheral surface of the outer peripheral wall portion, the space between the inner peripheral wall portion and the outer peripheral wall portion of the ring portion has the shape as described above.

A cooling device according to a third aspect of the present invention is the cooling device of the first or second aspect , wherein the tip of the outer peripheral wall portion is located downstream of the tip of the inner peripheral wall portion in the air flow direction. Further, the downstream end portion of the outer peripheral edge of the cooling fan in the air flow direction is located downstream of the front end of the inner peripheral wall portion in the air flow direction.

  In this cooling device, the downstream end portion of the outer peripheral edge of the cooling fan in the air flow direction is disposed downstream of the front end of the inner peripheral wall portion in the air flow direction, that is, outside the inner peripheral wall portion. By such a positional relationship between the cooling fan and the inner peripheral wall portion, the effect of increasing the air flow rate by the cooling fan by the fan shroud and the ring portion is further improved.

A work machine according to a fourth aspect of the present invention is an engine, a radiator that circulates a cooling medium for cooling the engine, and a cooling device according to any one of claims 1 to 3 that generates a flow of air that passes through the radiator. Is provided.

  In this work machine, the space between the inner peripheral wall portion and the outer peripheral wall portion of the ring portion has a shape that gradually expands from the bottom side toward the tip side. Thereby, the air flow rate by the cooling fan can be sufficiently increased.

  In the cooling device and the work machine according to the present invention, the space between the inner peripheral wall portion and the outer peripheral wall portion of the ring portion has a shape that gradually widens from the bottom side toward the tip side. Thereby, the air flow rate by the cooling fan can be sufficiently increased.

1 is an external view of a hydraulic excavator according to an embodiment of the present invention. The figure which shows the state which opened the engine hood of the engine room. The top view which shows the structure in an engine hood. The top view which shows the structure of the cooling device in an engine hood. The perspective view which shows the structure of a cooling device. The schematic diagram which shows the positional relationship of an engine and a cooling device. The front view of the ring part with which a cooling device is provided. IX-IX sectional drawing in FIG. The graph which compares the performance of the cooling device which concerns on embodiment of this invention, and the conventional cooling device. Sectional drawing which shows an example of the type | mold used for manufacture of a ring part.

[overall structure]
FIG. 1 shows a hydraulic excavator 1 as an embodiment of a work machine according to the present invention. The hydraulic excavator 1 includes a lower traveling body 2, a swivel base 3, a work implement 4, a counterweight 5, an engine room 6, an equipment room 9, a cab 10, and a cooling device 20 (see FIG. 2). It has.

  The lower traveling body 2 causes the hydraulic excavator 1 to travel by rotating the covering belt P. Moreover, the swivel base 3 is mounted on the lower traveling body 2 so as to be able to turn.

  The swivel base 3 can turn in any direction on the lower traveling body 2. On the upper surface of the swivel 3, a work machine 4, a counterweight 5, an engine room 6, and a cab 10 are placed.

  The work machine 4 includes a boom 11, an arm 12, and a bucket 13. The boom 11 is rotatably attached to the swivel base 3. The arm 12 is rotatably attached to the boom 11. The bucket 13 is rotatably attached to the arm 12. These members are driven by hydraulic cylinders 11a, 12a, and 13a, thereby performing operations such as excavation.

  The counterweight 5 is made of, for example, scrap steel or concrete in a steel plate box and hardened. The counterweight 5 is provided to balance the vehicle body during work such as excavation. The counterweight 5 is disposed behind the engine room 6.

  As shown in FIG. 2, the engine room 6 is disposed adjacent to the counterweight 5. The engine room 6 has an upper opening for inspection, and an engine hood 14 is provided so that the upper opening can be opened and closed. The engine room 6 accommodates an engine 6 a that is a drive source for driving the lower traveling body 2 and the work machine 4, and a cooling device 20.

  The equipment room 9 is disposed behind the work machine 4 and houses a fuel tank, a hydraulic oil tank, an operation valve, and the like (not shown). In the hydraulic oil tank, hydraulic oil for driving hydraulic actuators such as the hydraulic cylinders 11a, 12a, and 13a is stored.

  The cab 10 is disposed on the side of the work machine 4 on the swivel 3 so that the operator can see the tip of the work machine 4.

  The cooling device 20 is disposed adjacent to the engine 6 a in the engine room 6. The cooling device 20 cools the cooling water or hydraulic oil of the engine 6a. Hereinafter, the configuration of the cooling device 20 will be described in detail.

[Configuration of Cooling Device 20]
The cooling device 20 is a device that cools the cooling water and hydraulic oil of the engine 6a. As shown in FIGS. 3 to 6, the cooling device 20 includes a cooling fan 21, a cooling core 30, and a fan shroud 40.

  The cooling fan 21 is directly connected to the engine 6a and is driven to rotate by the engine 6a. As shown in FIG. 5, the cooling fan 21 is an axial fan and includes a boss portion 21b and a plurality of blade members 21a provided around the boss portion 21b. The cooling fan 21 generates an air flow through the cooling core 30 by being driven to rotate. The number of blade members 21a varies depending on the amount of air blown by the cooling fan 21 and the size thereof, but is generally about 6 to 11 sheets. When the cooling fan 21 is driven, an air flow is formed in the direction from the cooling core 30 toward the cooling fan 21 as indicated by an arrow F in FIGS. 3 and 6. In other words, the cooling fan 21 is disposed on the downstream side of the cooling core 30 in the air flow generated by the cooling fan 21. In the following description, the direction of arrow F in FIGS. 3 and 6 is referred to as the air flow direction. In FIGS. 3, 4, 6 and 8, the left side is the upstream side and the right side is the downstream side.

  The cooling core 30 is a unit that cools cooling water as a cooling medium by heat exchange with air. As shown in FIG. 4, the cooling core 30 includes a radiator 31, an oil cooler 32, an after cooler 33, and the like.

  The radiator 31 circulates cooling water for cooling the engine 6a, and reduces the temperature of the cooling water by causing heat exchange with air flowing by the cooling fan 21.

  The oil cooler 32 reduces the temperature of the hydraulic oil by causing heat exchange between the hydraulic oil supplied from the hydraulic oil tank to the hydraulic circuit and having increased in temperature, and the air flowing by the cooling fan 21.

  The aftercooler 33 cools the compressed air by causing heat exchange between the compressed air from the turbocharger (not shown) of the engine 6 a and the air flowing by the cooling fan 21. The compressed air is cooled and then sent to the intake manifold of the engine 6a.

  As shown in FIGS. 5 and 6, the fan shroud 40 is attached so as to cover the outer peripheral portion of the blade member 21 a of the cooling fan 21, and has a case portion 41. The case part 41 is a box-shaped member having a circular opening formed along the outer peripheral portion of the blade member 21a. Further, a ring portion 51 is attached to the case portion 41.

  The ring part 51 is a member for increasing the air flow rate by the cooling fan 21. The ring part 51 is a separate member separate from the case part 41, and is attached to the inner peripheral edge of the opening of the case part 41. The ring portion 51 is made of resin and is manufactured by a known molding technique such as injection molding. As shown in FIGS. 6 to 8, the ring portion 51 has an inner peripheral wall portion 52, an outer peripheral wall portion 53, a bottom portion 54, and a flange portion 55, and these portions are integrally formed. ing.

  The inner peripheral wall portion 52 is provided so as to cover the outer peripheral side of the cooling fan 21 and has a circular tubular shape. As shown in FIG. 6, the inner peripheral wall portion 52 is located at the edge of the opening of the case portion 41 and is close to the outer peripheral edge of the cooling fan 21. The diameter of the inner peripheral wall portion 52 is larger than the outer diameter of the cooling fan 21, and the gap G between them (hereinafter referred to as “chip clearance”) G is, for example, 15 mm. Further, as shown in FIG. 8, the outer peripheral surface 56 of the inner peripheral wall portion 52 is tapered so that the outer peripheral surface 56 is reduced in diameter toward the distal end side, that is, the downstream side of the air flow. Further, the inner peripheral surface 57 of the inner peripheral wall portion 52 is tapered so that the inner peripheral surface 57 is reduced in diameter toward the tip side. The taper angle b2 of the inner peripheral surface 57 of the inner peripheral wall portion 52 is smaller than the taper angle b1 of the outer peripheral surface 56 of the inner peripheral wall portion 52. For example, the taper angle b1 of the outer peripheral surface 56 of the inner peripheral wall portion 52 is 1 °, and the taper angle b2 of the inner peripheral surface 57 of the inner peripheral wall portion 52 is 0.5 °. At the tip of the inner peripheral wall 52, the outer peripheral corner 63 is connected by a curved surface, but the inner peripheral corner 64 is a sharp edge that is not connected by a curved surface. Further, the corner 67 at the upstream end of the air flow in the inner peripheral wall 52 is also a sharp edge.

  The outer peripheral wall portion 53 has a tubular shape, and is disposed concentrically with the inner peripheral wall portion 52 so as to surround the outer peripheral side of the inner peripheral wall portion 52. The outer peripheral wall portion 53 is disposed at a radial interval with respect to the inner peripheral wall portion 52, and an annular space S is provided between the outer peripheral wall portion 53 and the inner peripheral wall portion 52. A taper is provided on the inner peripheral surface 58 of the outer peripheral wall portion 53 so that the inner peripheral surface 58 increases in diameter toward the distal end side. Further, a taper is provided on the outer peripheral surface 59 of the outer peripheral wall portion 53 so that the outer peripheral surface 59 is reduced in diameter toward the distal end side. The taper angle a2 of the inner peripheral surface 58 of the outer peripheral wall 53 and the taper angle a1 of the outer peripheral surface 59 of the outer peripheral wall 53 are the same size, for example, 1 °. At the tip of the outer peripheral wall 53, the outer peripheral corner 61 is connected by a curved surface, but the inner peripheral corner 62 is a sharp edge that is not connected by a curved surface.

  The length of the inner peripheral wall portion 52 in the air flow direction is smaller than the length of the outer peripheral wall portion 53 in the air flow direction. Further, the downstream end portion of the outer peripheral wall portion 53 in the air flow direction is located downstream of the inner peripheral wall portion 52 in the air flow direction. The downstream end portion of the outer peripheral edge of the cooling fan 21 in the air flow direction is located on the downstream side of the inner peripheral wall portion 52 in the air flow direction.

  The bottom portion 54 is provided between the inner peripheral wall portion 52 and the outer peripheral wall portion 53 on the upstream side in the air flow direction from the front end of the inner peripheral wall portion 52 and the front end of the outer peripheral wall portion 53, and has a flat shape. Specifically, the bottom 54 connects the upstream end of the outer peripheral wall 53 in the air flow direction and the upstream end of the inner peripheral wall 52 in the air flow direction. The bottom portion 54 closes the upstream side in the air flow direction of the space S between the outer peripheral wall portion 53 and the inner peripheral wall portion 52. In addition, the corner | angular part 65 between the surface by the side of the space S of the bottom part 54 and the outer peripheral surface 56 of the inner peripheral wall part 52 is connected by the curved surface. A corner 66 between the surface of the bottom 54 on the space S side and the inner peripheral surface 58 of the outer peripheral wall 53 is also connected by a curved surface.

  The flange portion 55 is provided on the outer peripheral side of the outer peripheral wall portion 53 and has a flat shape. The flange portion 55 is provided with a plurality of holes 68 at intervals in the circumferential direction, and metal pipe members 69 are inserted into these holes 68. Bolts for fixing the ring portion 51 to the case portion 41 are inserted into these pipe members 69. Further, the outer peripheral surface 74 of the flange portion 55 is tapered so that the outer peripheral surface 74 is reduced in diameter toward the downstream side of the air flow. The taper angle C of the outer peripheral surface 74 of the flange portion 55 is larger than the taper angle a2 of the inner peripheral surface 58 of the outer peripheral wall portion 53 and the taper angle a1 of the outer peripheral surface 59 of the outer peripheral wall portion 53. It is.

[Feature]
In the cooling device 20, the ring portion 51 as described above is provided, so that the air flow rate by the cooling fan 21 can be increased. In particular, in the ring portion 51, the distance between the outer peripheral surface 56 of the inner peripheral wall portion 52 and the inner peripheral surface 58 of the outer peripheral wall portion 53 is from the bottom 54 side toward the distal end side of the inner peripheral wall portion 52 and the outer peripheral wall portion 53. The shape gradually expands. Thereby, the effect which increases the flow volume of the air by the cooling fan 21 by the fan shroud 40 can be improved more.

  In FIG. 9, the relationship between the air flow rate (air volume) and the noise level by the cooling device 20 of the present embodiment is indicated by L1. As a comparative example, the relationship between the air flow rate and the noise level by a conventional cooling device is indicated by L2. In the cooling device of the comparative example, the distance between the outer peripheral surface 56 of the inner peripheral wall portion 52 and the inner peripheral surface 58 of the outer peripheral wall portion 53 is constant. As is clear from FIG. 9, when the noise level is the same, the cooling device 20 according to the present embodiment has a larger air volume than the cooling device of the comparative example.

  Further, the outer peripheral surface 56 of the inner peripheral wall portion 52 is provided with a taper so that the outer peripheral surface 56 is reduced in diameter toward the tip side, that is, the downstream side of the air flow. The inner peripheral surface 57 of the inner peripheral wall portion 52 is tapered so that the inner peripheral surface 57 is reduced in diameter toward the tip side. For this reason, for example, the ring part 51 can be easily manufactured using a pair of molds 71 and 72 as shown in FIG. That is, when a taper is provided on the inner peripheral surface 57 of the inner peripheral wall portion 52 so that the inner peripheral surface 57 increases in diameter toward the distal end side, the mold 71 is removed in FIG. 10 (see arrow A1). ) And interfere with the mold 71. In this case, it is necessary to divide the mold 71, and the manufacturing apparatus becomes more complicated. However, the ring part 51 can be easily manufactured by making the inner peripheral wall part 52 into a tapered shape as described above.

  Furthermore, the taper angle b2 of the inner peripheral surface 57 of the inner peripheral wall portion 52 is smaller than the taper angle b1 of the outer peripheral surface 56 of the inner peripheral wall portion 52. For this reason, the chip clearance G (refer FIG. 6) between the cooling fan 21 and the internal peripheral surface 57 of the internal peripheral wall part 52 can be made small. Thereby, even if the inner peripheral wall portion 52 is provided with a taper as described above, it is possible to suppress an increase in the tip clearance that causes a decrease in the air flow rate by the cooling fan 21.

[Other Embodiments]
(A) In the above embodiment, both the outer peripheral surface 56 of the inner peripheral wall portion 52 and the inner peripheral surface 58 of the outer peripheral wall portion 53 are tapered, but only the outer peripheral surface 56 of the inner peripheral wall portion 52 is tapered. May be provided. Further, the taper angle of the outer peripheral surface 56 of the inner peripheral wall portion 52 and the taper angle of the inner peripheral surface 58 of the outer peripheral wall portion 53 may be different.

(B) taper is not provided on the outer peripheral surface 59 of the outer peripheral wall 53 may be parallel to the air flow direction.

  (C) The outer peripheral wall portion 53, the inner peripheral wall portion 52, the bottom portion 54, and the flange portion 55 are not integrally formed, and some or all of them may be formed separately.

  INDUSTRIAL APPLICABILITY The present invention has an effect of sufficiently increasing the air flow rate of the cooling fan without increasing the rotation speed of the cooling fan, and is useful as a cooling device and a work machine.

6a Engine 20 Cooling device 21 Cooling fan 31 Radiator 40 Fan shroud 51 Ring portion 52 Inner peripheral wall portion 53 Outer peripheral wall portion 54 Bottom

Claims (4)

A cooling fan,
A fan shroud provided on the outer peripheral side of the cooling fan;
A tubular inner peripheral wall provided to cover the outer peripheral side of the cooling fan, a tubular outer peripheral wall disposed so as to surround the outer peripheral side of the inner peripheral wall, the tip of the outer peripheral wall, and the A bottom portion provided between the inner peripheral wall portion and the outer peripheral wall portion, which is positioned upstream of the tip of the inner peripheral wall portion in the air flow direction by the cooling fan, and is provided in the fan shroud. A ring part,
With
Distance between the inner circumferential surface of the outer peripheral surface and the outer peripheral wall portion of the inner peripheral wall portion, Ri your spread gradually toward the distal end side of the inner circumferential wall and the outer peripheral wall portion from said bottom side,
The outer peripheral surface of the inner peripheral wall portion is provided with a taper so that the outer peripheral surface is reduced in diameter toward the tip side,
The inner peripheral surface of the inner peripheral wall portion is provided with a taper so that the inner peripheral surface is reduced in diameter toward the tip side.
The taper angle of the inner peripheral surface of the inner peripheral wall portion is smaller than the taper angle of the outer peripheral surface of the inner peripheral wall portion,
Cooling system. A taper is provided on the inner peripheral surface of the outer peripheral wall so that the inner peripheral surface expands toward the tip side.
The cooling device according to claim 1. The tip of the outer peripheral wall is located downstream of the tip of the inner peripheral wall in the air flow direction,
The downstream end in the air flow direction of the outer peripheral edge of the cooling fan is located on the downstream side in the air flow direction from the tip of the inner peripheral wall portion,
The cooling device according to claim 1 or 2 . Engine,
A radiator for circulating a cooling medium for cooling the engine;
The cooling device according to any one of claims 1 to 3 , which generates a flow of air through the radiator.
Work machine equipped with.

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