JP2017206866A - Construction machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a construction machine capable of improving the assemblability, the maintainability or the like of peripheral components of an engine by cooling a coupling within a coupling case using cooling air with a simple constitution.SOLUTION: A first ventiduct 18 communicating between an engine chamber 16 and a coupling case 13 is formed. A second ventiduct 20 communicating between a pump chamber 17 and the coupling case 13 is formed. With this, The coupling case 13 is configured so that, when a cooling fan 11 is driven, cooling air flows therein through the first ventiduct 18 and the second ventiduct 20 due to a differential pressure which is generated between the engine chamber 16 and the pump chamber 17.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a construction machine such as a hydraulic excavator having a configuration in which, for example, a prime mover and a hydraulic pump are connected via a coupling.

  In general, a hydraulic excavator as a representative example of a construction machine includes a self-propelled lower traveling body, an upper revolving body that is turnably mounted on the lower traveling body and forms a vehicle body together with the lower traveling body, and the upper swivel It is comprised with the front apparatus provided in the front side of the body so that a heel-up and down movement was possible.

  The upper swing body of the excavator includes an engine mounted on a swing frame, a hydraulic pump driven by the engine, an output shaft of the engine and an input of the hydraulic pump for transmitting rotation of the engine to the hydraulic pump. A coupling that couples the shaft, a cooling fan that is provided on the opposite side of the hydraulic pump across the engine and that generates cooling air for cooling a heat exchanger such as a radiator and an oil cooler, the engine and the engine A coupling case that is provided between the hydraulic pump and accommodates the coupling therein, and covers the engine, the hydraulic pump, the coupling, a cooling fan, and a device including the heat exchanger on the swivel frame. An engine room in which the engine, the cooling fan, and the heat exchanger are accommodated in the exterior cover provided and in the exterior cover And a partition wall for partitioning the said hydraulic pump, a pump chamber coupled is housed.

  The coupling may use an elastic resin material as a damper in order to absorb engine torque fluctuation transmitted to the hydraulic pump. However, in the vicinity of the engine and the hydraulic pump, the heat generated by them generates a high temperature state. Therefore, a coupling using a resin material having low heat resistance as a damper may be deteriorated in durability when exposed to a high temperature state. There is.

  Therefore, some construction machines have a configuration in which an intake port and an exhaust port are provided in the coupling case, and the exhaust port and the inside of the cover of the cooling fan are connected by an exhaust hose (see, for example, Patent Document 1). In this patent document 1, the negative pressure which generate | occur | produces with a cooling fan is utilized, and the air in a coupling case is sucked out from an exhaust port via an exhaust hose. As a result, in the coupling case, air is actively introduced from the intake port to cool the coupling (resin damper).

JP 2009-250133 A

  Here, in patent document 1, in order to cool a coupling, it is set as the structure which connects the exhaust port of a coupling case, and the inside of the cover of a cooling fan with an exhaust hose. In this case, the exhaust hose is routed around the engine. On the other hand, many parts, pipes, harnesses, and the like are provided around the engine. As a result, there is a problem in that the work for arranging the exhaust hose is troublesome and the workability when performing the installation work, maintenance, etc. of other parts is reduced.

  The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to allow the coupling in the coupling case to be cooled with cooling air with a simple configuration, and to assemble the peripheral components of the prime mover. An object of the present invention is to provide a construction machine that can improve the performance and maintainability.

  A construction machine according to the present invention includes a prime mover mounted on a body frame, a hydraulic pump driven by the prime mover, an output shaft of the prime mover and an input shaft of the hydraulic pump for transmitting rotation of the prime mover to the hydraulic pump. A coupling that connects the motor, a cooling fan that is provided on the opposite side of the hydraulic pump and that generates cooling air for cooling the heat exchanger, and is provided between the prime mover and the hydraulic pump A coupling case that houses the coupling therein, and an exterior cover provided on the vehicle body frame in a state of covering devices including the prime mover, hydraulic pump, coupling, cooling fan, and heat exchanger, Inside the outer cover, a prime mover chamber in which the prime mover, a cooling fan, and a heat exchanger are accommodated, and a pump chamber in which the hydraulic pump and a coupling are accommodated. In the construction machine comprising a partition wall that is partitioned into a first partition, a first air passage is provided to communicate the prime mover chamber and the coupling case, and the pump chamber and the coupling case communicate with each other. A second air passage is provided, and the first air passage and the second air passage are formed in the coupling case by a differential pressure generated between the prime mover chamber and the pump chamber by driving the cooling fan. Cooling air flows through the second air passage.

  According to the present invention, it is possible to cool the coupling in the coupling case with the cooling air with a simple configuration, and it is possible to improve the assemblability and maintainability of the peripheral parts of the prime mover.

1 is a front view showing a hydraulic excavator as a construction machine according to a first embodiment of the present invention. It is sectional drawing which expands and shows the rear part of an upper revolving body from the arrow II-II direction in FIG. It is sectional drawing which expands and shows a part of engine in FIG. 2, a hydraulic pump, a coupling, a coupling case, etc. It is sectional drawing of the principal part expansion seen from the arrow IV-IV direction in FIG. It is a disassembled perspective view which disassembles and shows a flywheel, a hydraulic pump, a coupling, a coupling case, and the like. It is sectional drawing which looked at the rear part of the upper turning body provided with the cooling fan by the 2nd Embodiment of this invention, a coupling case, etc. from the same position as FIG. 7 is a cross-sectional view of a part of the engine, the hydraulic pump, the coupling, the coupling case, each air passage, and the like in FIG. 6 as viewed from the same position as in FIG. It is sectional drawing which looked at the rear part of the upper turning body provided with the engine and assist electric motor by the 3rd Embodiment of this invention from the same position as FIG. It is sectional drawing which looked at the modification of this invention from the same position as FIG.

  Hereinafter, as a typical example of a construction machine according to an embodiment of the present invention, a crawler type hydraulic excavator will be described as an example, and will be described in detail according to the accompanying drawings.

  1 to 5 show a first embodiment of the present invention. In the first embodiment, a diesel engine is applied as a prime mover, and a suction-type cooling fan that supplies air sucked from the outside to a heat exchanger is applied as a cooling fan.

  In FIG. 1, a hydraulic excavator 1 constitutes a crawler type construction machine. The hydraulic excavator 1 is a self-propelled crawler-type lower traveling body 2, is pivotably mounted on the lower traveling body 2, and constitutes a vehicle body together with the lower traveling body 2. The front device 4 is provided in front of the revolving structure 3 and in front of the rear direction so as to be movable up and down, and includes a front device 4 that performs excavation work of earth and sand using a plurality of actuators as a power source.

  The turning frame 5 is configured as a vehicle body frame that forms a support structure for the upper turning body 3. As shown in FIG. 2, the revolving frame 5 has a flat bottom plate 5A made of a thick steel plate or the like extending in the front and rear directions, and is erected on the bottom plate 5A, with a predetermined interval in the left and right directions. Left and right vertical plates 5B and 5C extending in the front and rear directions, and the bottom plate 5A and each of the vertical plates 5B and 5C are projected to the outside in the left and right directions, and a plurality are provided at intervals in the front and rear directions. The extended beam 5D and the left and right side frames 5F and 5C, which extend forward and rearward with an interval in the left and right directions of the vertical plates 5B and 5C, and are attached to the distal ends of the extended beams 5D. It is comprised including.

  On the rear side of the swivel frame 5, a plurality of, for example, two supports positioned on the left side in the left and right directions and spaced in the front and rear directions are positioned between the left and right vertical plates 5B and 5C. A bracket 5G (only one rear side is shown) and two support brackets 5H (see FIG. 4) located on the right side in the left and right directions and spaced in the front and rear directions are provided. The two left support brackets 5G located on the left side (the heat exchanger 12 side described later) are disposed in the vicinity of the left vertical plate 5B and support the left side portion of the engine 7 via a vibration isolation mount 8 described later. It is. On the other hand, the two right support brackets 5H located on the right side (the hydraulic pump 9 side described later) are disposed in the vicinity of the right vertical plate 5C and support the right side portion of the engine 7 via the vibration isolation mount 8. is there.

  As shown in FIGS. 2 and 3, the revolving frame 5 is provided with a plurality of undercovers 5J and 5K (only two on the rear side are shown) so as to cover the space between the extended beams 5D. Among the undercovers 5J and 5K, the right undercover 5K is provided with a flow port 5L located below the hydraulic pump 9. The circulation port 5L is for circulating air between a pump chamber 17 described later and the outside.

  The counterweight 6 is provided on the rear side of the turning frame 5. This counterweight 6 balances the weight with the front device 4 and is formed as a heavy object having a convex arcuate rear surface. The counterweight 6 is attached to the rear part of the left and right vertical plates 5B and 5C.

  The engine 7 constitutes a prime mover mounted at the rear side position of the turning frame 5 in a horizontally placed state extending in the left and right directions. A cooling fan 11 is provided on the left side of the engine 7 for supplying cooling air to a heat exchanger 12 described later. On the other hand, a flywheel 7A constituting an output shaft is provided on the right side of the engine 7, and a case joint surface in which a plurality of female screw holes (not shown) are provided at positions surrounding the flywheel 7A. 7B is formed. The case joint surface 7B is joined to an engine joint surface 13A of a coupling case 13 described later.

  Further, the engine 7 has four mounting legs 7C and 7D (two on the left side and one on the right side) positioned on the side surfaces in the front and rear directions so as to correspond to the support brackets 5G and 5H of the revolving frame 5, respectively. Only one is shown). The mounting legs 7C and 7D are attached to the support brackets 5G and 5H of the revolving frame 5 through vibration-proof mounts 8, respectively. Thereby, the engine 7 is supported on the rear side of the turning frame 5 in a vibration-proof state.

  The hydraulic pump 9 is provided on the right side of the engine 7 and is driven by the engine 7. The hydraulic pump 9 discharges hydraulic oil supplied from a hydraulic oil tank (not shown) as pressure oil toward a control valve device (not shown). The hydraulic pump 9 includes an input shaft 9A that protrudes toward the engine 7, a speed reduction mechanism that decelerates the rotational force input from the input shaft 9A, and a pump body that is driven by the reduced rotational force (both not shown). ).

  As shown in FIG. 3, the coupling 10 connects the flywheel 7 </ b> A of the engine 7 and the input shaft 9 </ b> A of the hydraulic pump 9. Thereby, the coupling 10 can transmit the rotation of the engine 7 to the hydraulic pump 9. The coupling 10 is accommodated in a coupling case 13 described later. The coupling 10 elastically connects the flywheel 7A serving as the output shaft of the engine 7 and the input shaft 9A of the hydraulic pump 9 in order to absorb the torque fluctuation of the engine 7 and the deviation of the rotation center axis. .

  That is, as shown in FIG. 5, the coupling 10 includes a plurality of, for example, four engine-side blocks 10 </ b> A that are attached to the flywheel 7 </ b> A serving as the output shaft of the engine 7 at intervals in the circumferential direction (rotational direction). A hub member 10B attached to the input shaft 9A of the hydraulic pump 9, and a plurality of, for example, four pump sides, attached to the outer peripheral side of the hub member 10B at intervals in the circumferential direction in a state of projecting radially outward. The block 10C is constituted by an elastic body 10D that surrounds the hub member 10B and elastically connects the engine side blocks 10A and the pump side blocks 10C. Here, the elastic body 10D is formed in a thick cylindrical shape using, for example, an elastic resin material.

  The coupling 10 thus configured includes each engine side block 10A attached to the flywheel 7A of the engine 7 and each pump side block 10C attached to the input shaft 9A of the hydraulic pump 9 via the hub member 10B. Are opposed in the circumferential direction across the elastic body 10D. Thereby, the coupling 10 can relieve the impact and torque fluctuation transmitted from the engine 7 to the hydraulic pump 9 by the elastic body 10D, for example.

  As shown in FIG. 2, the cooling fan 11 is provided on the side opposite to the hydraulic pump 9 across the engine 7, that is, on the left side of the engine 7. The cooling fan 11 is rotated by the engine 7 to suck air outside the exterior cover 14 (to be described later) into the engine chamber 16 as cooling air, and supply the sucked cooling air to the heat exchanger 12. It is configured as a cooling fan.

  The heat exchanger 12 is provided facing the cooling fan 11 upstream in the flow direction of the cooling air, that is, on the left side of the cooling fan 11. The heat exchanger 12 accommodates, for example, a radiator 12B that cools cooling water of the engine 7, an oil cooler (not shown) that cools hydraulic oil, and the like in a rectangular frame-shaped support frame 12A. A cylindrical fan shroud 12A1 surrounding the cooling fan 11 is provided on the support frame 12A.

  The coupling case 13 is provided between the engine 7 and the hydraulic pump 9. The coupling case 13 houses the coupling 10 that transmits the rotation of the engine 7 to the hydraulic pump 9. As shown in FIGS. 3 and 5, the coupling case 13 has a flange-shaped (annular) engine joint surface 13 </ b> A facing the case joint surface 7 </ b> B of the engine 7 on the engine 7 side (left side). . On the other hand, the hydraulic pump 9 side (right side) of the coupling case 13 is gradually reduced in diameter, and the hydraulic pump 9 is attached to an end portion having a small diameter.

  That is, the coupling case 13 is contracted toward the hydraulic pump 9 from the large-diameter cylindrical surface portion 13B extending from the inner periphery of the engine joint surface 13A to the hydraulic pump 9 side and the end portion of the cylindrical surface portion 13B on the hydraulic pump 9 side. And a tapered surface portion 13C having a diameter. Here, the inclination angle of the tapered surface portion 13 </ b> C is set according to conditions such as the size and shape of the flywheel 7 </ b> A and the coupling 10 of the engine 7 housed in the coupling case 13. Therefore, the inclination angle of the tapered surface portion 13C can be set as appropriate, and it can also be a flat surface portion instead of the tapered surface portion 13C.

  The coupling case 13 is attached to the right end portion of the engine 7 by causing the engine joint surface 13A to face the case joint surface 7B of the engine 7 and screwing a bolt 13D (see FIG. 4) around it. Furthermore, the hydraulic pump 9 can be attached to the coupling case 13 at the end opposite to the engine joint surface 13A.

  Further, a first air passage 18 to be described later is provided in the cylindrical surface portion 13B of the coupling case 13. Further, the tapered surface portion 13 </ b> C of the coupling case 13 is provided with a second ventilation path 20, which will be described later, located near the outer periphery thereof.

  As shown in FIG. 2, the exterior cover 14 is provided on the revolving frame 5 so as to cover devices including the engine 7, the hydraulic pump 9, the coupling 10, the cooling fan 11, and the heat exchanger 12. The exterior cover 14 is provided between a cab 21 and a counterweight 6 which will be described later. Specifically, the exterior cover 14 is located above the cover portions 14A and 14B, a left surface cover portion 14A covering the left side of the heat exchanger 12, a right surface cover portion 14B covering the right side of the hydraulic pump 9 and the like. And an upper surface cover portion 14C that covers the upper side of the engine 7 and the like.

  Here, a circulation port 14D for sucking outside air is provided at an upper position of the left surface cover portion 14A and a left position of the upper surface cover portion 14C on the upstream side in the flow direction of the cooling air. On the other hand, a circulation port 14 </ b> E for discharging warmed cooling air from the engine chamber 16 is provided at an intermediate portion in the left and right directions of the upper surface cover portion 14 </ b> C on the downstream side in the cooling air flow direction. Further, a flow port 14F for discharging warm air in the pump chamber 17 is provided on the right side portion of the upper surface cover portion 14C.

  The partition wall 15 is provided on the right side in the exterior cover 14 so as to extend forward, backward, upward, and downward. The partition wall 15 includes an engine chamber 16 as a prime mover chamber in which the engine 7, the cooling fan 11, and the heat exchanger 12 are housed, a hydraulic pump 9, and a coupling 10 (most of the coupling case 13). Is separated from the pump chamber 17 in which the As shown in FIG. 3, the partition wall 15 is, for example, a plate body positioned between the right vertical plate 5 </ b> C of the revolving frame 5 and the upper surface cover portion 14 </ b> C of the outer cover 14 and disposed on the outer peripheral side of the coupling case 13. It is formed as. Specifically, as shown in FIG. 4, the partition wall 15 that covers the outer peripheral side of the coupling case 13 is positioned on the upper side of the coupling case 13 and extends in the front and rear directions, and the upper plate portion 15A. The case 13 is formed in a gate shape by a front lower plate portion 15B and a rear lower plate portion 15C extending downward from the upper plate portion 15A so as to sandwich the case 13 from the front and rear directions.

  The partition wall 15 is disposed on the outer peripheral side of the coupling case 13 that is shifted to the right from the boundary position (attachment site) between the engine 7 and the coupling case 13. Thereby, even if the situation where hydraulic fluid leaks and scatters on the hydraulic pump 9 side, for example, the partition 15 covers the space between the coupling case 13 and the outer cover 14 to scatter the hydraulic fluid. Can be prevented from coming into contact with the high-temperature engine 7 side. The partition wall 15 can also be disposed in the vicinity of the connection position between the engine 7 and the coupling case 13. In this case, the coupling case 13 is almost entirely disposed in the pump chamber 17.

  Here, the relationship between the pressure in the engine chamber 16 and the pressure in the pump chamber 17 will be described. When the excavator 1 is in operation, a difference is generated between the pressure inside the engine chamber 16 and the pressure inside the pump chamber 17. Specifically, the pump chamber 17 communicates with the outside through a flow port 5L provided in the under cover 5K of the swivel frame 5 and a flow port 14F provided in the upper surface cover portion 14C of the outer cover 14. It is atmospheric pressure.

  On the other hand, the engine chamber 16 communicates with the outside through a circulation port 14 </ b> E provided in the upper surface cover portion 14 </ b> C of the exterior cover 14. However, a large amount of air exceeding the amount of air discharged from the circulation port 14 </ b> E is sucked into the engine chamber 16 from the outside by the suction-type cooling fan 11. For this reason, the engine chamber 16 has a pressure higher than the atmospheric pressure, that is, a positive pressure. Thereby, a differential pressure is generated between the engine chamber 16 and the pump chamber 17.

  Next, the structure of the 1st ventilation path 18 and the 2nd ventilation path 20 used as the characteristic part of 1st Embodiment is demonstrated in detail.

  3 and 5, the first air passage 18 is provided on the outer peripheral side of the coupling case 13. For example, the first air passage 18 is composed of one pipe member, and the base end side thereof is attached to the cylindrical surface portion 13 </ b> B of the coupling case 13. Here, the first air passage 18 is an inflow side air passage through which cooling air flows into the coupling case 13. The first air passage 18 on the inflow side is provided so as to be connected to the lower position of the coupling case 13, that is, the lowermost part of the cylindrical surface portion 13B.

  The first air passage 18 extends downward from the lowermost portion of the cylindrical surface portion 13 </ b> B, bends and extends to the left side (engine 7 side), and the opening 18 </ b> A on the tip side reaches the engine chamber 16. Thereby, the first air passage 18 allows the engine compartment 16 and the coupling case 13 to communicate with each other.

  The first air passage 18 can communicate with a lower position in the engine compartment 16 by connecting to the lowermost portion of the cylindrical surface portion 13B. In this case, since the low temperature air circulates in a low position in the engine chamber 16, the first air passage 18 circulates the low temperature air flowing in the low position in the coupling case 13 in the engine chamber 16. Can be made. Furthermore, the first air passage 18 is disposed such that the opening 18A on the tip side faces the left side. Thereby, the cooling air flowing from the left side to the right side in the engine chamber 16 by the cooling fan 11 efficiently flows into the first air passage 18.

  The filter member 19 is provided in the opening 18 </ b> A at the tip of the first air passage 18. The filter member 19 can suppress the entry of foreign matter into the coupling case 13 by catching foreign matter such as dust, insects, and dust that has entered the engine chamber 16.

  The second air passage 20 is provided on the outer peripheral side of the coupling case 13. For example, the second air passage 20 is made of one pipe member, and the base end side thereof is attached to the tapered surface portion 13 </ b> C of the coupling case 13. Here, the second ventilation path 20 is an outflow side ventilation path through which cooling air flows out of the coupling case 13. In addition, the second ventilation path 20 on the outflow side is away from the first ventilation path 18 on the inflow side, specifically, at the upper position of the coupling case 13, that is, at the upper portion of the tapered surface portion 13C. Connected and provided.

  The second ventilation path 20 extends rightward from the upper part of the tapered surface portion 13 </ b> C toward the upper side of the hydraulic pump 9, and the opening 20 </ b> A on the tip side opens into the pump chamber 17. Thereby, the second ventilation path 20 allows the pump chamber 17 and the coupling case 13 to communicate with each other. The filter member 19 described above is provided in the opening 20 </ b> A of the second air passage 20.

  The second ventilation path 20 can communicate with a high position in the engine compartment 16 by connecting to the upper portion of the tapered surface portion 13C. In this case, the cooling air whose temperature has been increased by exchanging heat with the coupling 10 in the coupling case 13 flows upward in the coupling case 13. Therefore, the second ventilation path 20 provided at a high position of the coupling case 13 can efficiently flow the warm cooling air that sequentially flows upward toward the pump chamber 17.

  In addition, the first air passage 18 is disposed at a lower position of the coupling case 13, and the second air passage 20 is disposed at an upper position of the coupling case 13. As a result, the first air passage 18 and the second air passage 20 are arranged at symmetrical positions with the axial center line of the coupling 10 in between. Therefore, in the coupling case 13, the circulation distance of the cooling air from the first ventilation path 18 to the second ventilation path 20 can be set long. As a result, the coupling 10 can be efficiently cooled by the cooling air.

  The cab 21 is mounted on the left front side of the revolving frame 5. The cab 21 is to be boarded by an operator, and a driver's seat on which the operator is seated, an operation lever for traveling, an operation lever for work, and the like (all not shown) are arranged.

  The hydraulic excavator 1 according to the first embodiment has the above-described configuration, and the operation thereof will be described next.

  The operator gets on the cab 21 of the upper swing body 3, starts the engine 7, and drives the hydraulic pump 9. Thereby, pressure oil is discharged from the hydraulic pump 9, and this pressure oil is supplied to various hydraulic actuators of the lower traveling body 2 and the front device 4 via the control valve device.

  When the operator who has boarded the cab 21 operates the operating lever for traveling, the vehicle can be moved forward or backward by the lower traveling body 2. On the other hand, when the operator in the cab 21 operates the operation lever, the front device 4 can be moved up and down to perform excavation work of earth and sand.

  During operation of the hydraulic excavator 1, torque output from the flywheel 7A serving as the output shaft of the engine 7 is transmitted to the input shaft 9A of the hydraulic pump 9 via the coupling 10 having the elastic body 10D. In this case, the elastic body 10 </ b> D of the coupling 10 can absorb torque fluctuation between the flywheel 7 </ b> A of the engine 7 and the input shaft 9 </ b> A of the hydraulic pump 9, a shift of the rotation center axis, and the like by elastic deformation. it can.

  When the excavator 1 is operating, the suction-type cooling fan 11 is rotated by the engine 7. Thereby, as shown by arrow A in FIG. 2, outside air is sucked into the engine compartment 16 from the circulation port 14D provided in the left surface cover portion 14A and the upper surface cover portion 14C of the outer cover 14, and heat exchange is performed as cooling air. Supplied to the vessel 12. The heat exchanger 12 can cool the engine coolant and hydraulic oil by exchanging heat.

  Next, as indicated by an arrow B, most of the cooling air that has passed through the heat exchanger 12 flows around the engine 7 and then flows from the circulation port 14E provided in the upper surface cover portion 14C to the outside. Discharged.

  On the other hand, as indicated by an arrow C in FIG. 3, a part of the cooling air that has passed through the heat exchanger 12 flows into the coupling case 13 from the engine chamber 16 through the first air passage 18. After the coupling 10 is cooled in the ring case 13, it flows out from the second ventilation path 20 to the pump chamber 17. At this time, since a differential pressure is generated between the positive pressure engine chamber 16 and the atmospheric pressure pump chamber 17, the cooling air flows into the first ventilation path 18, the coupling case 13, Through the air passage 20, the engine chamber 16 having a high pressure can be actively circulated to the pump chamber 17 having a low pressure. Thereby, in the coupling case 13, the coupling 10 can be efficiently cooled by many cooling air.

  As indicated by an arrow D, the cooling air that has flowed out of the second air passage 20 into the pump chamber 17 is provided in the circulation port 5L provided in the under cover 5K of the swivel frame 5 and the upper surface cover portion 14C of the exterior cover 14. It can be discharged to the outside through the distribution port 14F.

  Thus, according to the first embodiment, the first air passage 18 is provided in communication between the engine chamber 16 and the inside of the coupling case 13. Further, a second air passage 20 is provided so as to communicate the pump chamber 17 and the inside of the coupling case 13. In addition, cooling air is supplied into the coupling case 13 through the first air passage 18 and the second air passage 20 due to the differential pressure generated between the engine chamber 16 and the pump chamber 17 by driving the cooling fan 11. Is configured to flow.

  Therefore, by utilizing the differential pressure between the engine chamber 16 and the pump chamber 17, a large amount of cooling air can be circulated in the coupling case 13, and the coupling 10 can be efficiently cooled. it can. Thereby, in 1st Embodiment, like patent document 1, the coupling 10 can be cooled, without arranging a hose etc. around the engine 7. FIG.

  As a result, the coupling 10 in the coupling case 13 can be efficiently cooled with cooling air by a simple configuration in which the first ventilation path 18 and the second ventilation path 20 are provided in the coupling case 13. Thereby, the structure around the engine 7 can be simplified, and the assemblability and maintenance performance for assembling parts around the engine 7 can be improved.

  The first air passage 18 and the second air passage 20 are provided with a filter member 19 located at the open end portions, that is, at the respective openings 18A and 20A. Thereby, since the filter member 19 can suppress the entrance of foreign matter such as dust, insects, and dust into the coupling case 13, the durability and the like of the coupling 10 can be improved.

  On the other hand, the first air passage 18 on the inflow side through which the cooling air flows into the coupling case 13 is provided at a lower position of the coupling case 13. Further, the second ventilation path 20 on the outflow side for allowing cooling air to flow out from the inside of the coupling case 13 is provided at an upper position of the coupling case 13 that is higher than the first ventilation path 18.

  In this case, since the low temperature air circulates in a low position in the engine chamber 16, the first air passage 18 circulates the low temperature air flowing in the low position in the coupling case 13 in the engine chamber 16. Can be made. In addition, since the cooling air whose temperature has been increased by exchanging heat with the coupling 10 in the coupling case 13 flows upward in the coupling case 13, it has been warmed from the second ventilation path 20 provided at a high position. Cooling air can be efficiently discharged.

  In addition, the first air passage 18 and the second air passage 20 are arranged at symmetrical positions across the axial center line of the coupling 10. Therefore, in the coupling case 13, the circulation distance of the cooling air from the first ventilation path 18 to the second ventilation path 20 can be set long. By these things, in the coupling case 13, a cooling wind can be uniformly applied to the coupling 10, and the coupling 10 can be cooled efficiently.

  Next, FIG. 6 and FIG. 7 show a second embodiment of the present invention. A feature of the present embodiment is that a discharge type cooling fan that supplies air sucked from outside to a heat exchanger by discharging (exhausting) internal air toward the outside as a cooling fan is applied. is there. In the second embodiment, the same components as those in the first embodiment described above are denoted by the same reference numerals, and description thereof is omitted.

  In FIG. 6, the cooling fan 31 according to the second embodiment is provided on the left side of the engine 7. The cooling fan 31 is rotated by the engine 7 to discharge the air inside the engine chamber 16 toward the outside, so that the air sucked into the engine chamber 16 from the outside of the exterior cover 14 is discharged into the heat exchanger 12. It is configured as a discharge-type cooling fan that is supplied to the fan. Therefore, in the state where the discharge type cooling fan 31 is driven, the air in the engine chamber 16 is discharged, so that the engine chamber 16 has a pressure lower than the atmospheric pressure, that is, a negative pressure. As a result, a differential pressure is generated between the engine chamber 16 having a negative pressure and the pump chamber 17 having an atmospheric pressure.

  As shown in FIG. 7, the first air passage 32 according to the second embodiment is attached to the uppermost portion of the cylindrical surface portion 13 </ b> B of the coupling case 13. The first air passage 32 is an outflow side air passage through which the cooling air in the coupling case 13 flows out. The first air passage 32 extends upward from the uppermost portion of the cylindrical surface portion 13 </ b> B, bends and extends to the left side (engine 7 side), and the opening 32 </ b> A on the tip side reaches the engine chamber 16. As a result, the first air passage 32 allows the engine chamber 16 and the coupling case 13 to communicate with each other.

  The second air passage 33 according to the second embodiment is attached to a lower position of the tapered surface portion 13 </ b> C of the coupling case 13. The second air passage 33 is an inflow side air passage that allows cooling air to flow into the coupling case 13. The second ventilation path 33 extends rightward from the upper part of the tapered surface portion 13 </ b> C toward the lower side of the hydraulic pump 9, and the opening 33 </ b> A on the tip side opens into the pump chamber 17. Thereby, the second ventilation path 33 allows the pump chamber 17 and the coupling case 13 to communicate with each other.

  Next, the flow of air (cooling air) according to the second embodiment will be described. When the excavator 1 is in operation, the discharge type cooling fan 31 is rotated by the engine 7. As a result, as indicated by arrow E in FIG. 6, the cooling fan 31 blows air in the engine compartment 16 toward the heat exchanger 12, so that the air in the engine compartment 16 is The air is discharged from the circulation port 14D provided in the left cover portion 14A and the upper cover portion 14C. Along with this, as indicated by arrow F, external air flows from the circulation port 14E provided in the upper surface cover portion 14C. Thereby, the heat exchanger 12 can be cooled by the cooling air discharged by the cooling fan 31.

  Here, the engine chamber 16 has a negative pressure in the engine chamber 16 as air is discharged by the cooling fan 31, and therefore there is a difference between the engine chamber 16 having a negative pressure and the pump chamber 17 having an atmospheric pressure. Pressure is generated. As a result, as indicated by an arrow G, air flows into the pump chamber 17 from the flow port 5L of the under cover 5K of the swivel frame 5 and the flow port 14F of the upper surface cover portion 14C of the outer cover 14, and this flowed air As indicated by an arrow H, a part of the pressure is positively passed from the high pressure pump chamber 17 to the low pressure engine chamber 16 through the second air passage 33, the coupling case 13, and the first air passage 32. Can be distributed. Thereby, in the coupling case 13, the coupling 10 can be efficiently cooled by many cooling air.

  Thus, also in the second embodiment configured as described above, substantially the same operations and effects as those of the first embodiment described above can be obtained. In particular, in the second embodiment, the cooled air that has flowed into the pump chamber 17 from the flow port 5L of the under cover 5K of the swivel frame 5 and the flow port 14F of the upper surface cover portion 14C of the exterior cover 14 is used as a coupling case. 13 can flow in. Thereby, the coupling 10 can be efficiently cooled by the cold air.

  Next, FIG. 8 shows a third embodiment of the present invention. A feature of the present embodiment is that the prime mover is composed of an engine as an internal combustion engine and an assist electric motor provided in series with the engine located on the hydraulic pump side to assist the engine. This is because it is arranged on the outer peripheral side of the coupling case. Note that in the third embodiment, the same components as those in the first embodiment described above are denoted by the same reference numerals, and description thereof is omitted.

  In FIG. 8, reference numeral 41 denotes a prime mover according to the third embodiment. The prime mover 41 includes an engine 42 that is an internal combustion engine such as a diesel engine, and an assist electric motor 43 that is located on the hydraulic pump 9 side to assist the engine 42 and is provided in series with the engine 42. ing. A coupling case 13 is attached to the assist electric motor 43. Here, the prime mover 41 has a flywheel 42A and an attachment leg 42B that form an output shaft on the engine 42 side, and a case joint surface 43A and an attachment leg 43B on the assist electric motor 43 side.

  The coupling case 13 is attached to the case joint surface 43 </ b> A of the assist electric motor 43, and the coupling 10 is attached to the flywheel 42 </ b> A of the engine 42.

  Thus, also in the third embodiment configured as described above, substantially the same operations and effects as those of the first embodiment described above can be obtained. In particular, in the third embodiment, since the assist electric motor 43 is disposed on the coupling 10 side of the prime mover 41, the heat generated by the assist electric motor 43 may be transmitted to the coupling 10. However, according to the third embodiment, the cooling air is circulated in the coupling case 13 through the air passages 18 and 20 using the differential pressure between the engine chamber 16 and the pump chamber 17. The coupling 10 can be cooled by this cooling air.

  In the first embodiment, the first air passage 18 is formed by a pipe member connected to the cylindrical surface portion 13B of the coupling case 13, and the pipe member is extended to the engine 7 side to open the opening 18A. Is disposed in the engine compartment 16. However, the present invention is not limited to this. For example, the present invention may be configured as a modification shown in FIG.

  That is, in FIG. 9, the first air passage 51 is provided between the case joint surface 7 </ b> B of the engine 7 and the engine joint surface 13 </ b> A of the coupling case 13. For example, the first air passage 51 is configured as a passage that opens into the engine compartment 16 by forming a C-shaped groove in the lower part of the engine joint surface 13A of the coupling case 13. In addition to this, the first air passage may be formed by drilling the cylindrical surface portion 13B of the coupling case 13 on the engine chamber 16 side. These configurations can be similarly applied to other embodiments.

  On the other hand, in the first embodiment, the second air passage 20 is formed by a pipe member connected to the tapered surface portion 13C of the coupling case 13, and the opening 20A of the pipe member is disposed in the pump chamber 17. Yes. However, the present invention is not limited to this. For example, the second air passage may be formed by drilling the cylindrical surface portion 13B of the coupling case 13 on the pump chamber 17 side. This configuration can be similarly applied to other embodiments.

  Furthermore, in each embodiment, the crawler type hydraulic excavator 1 has been described as an example of the construction machine. However, the present invention is not limited to this, and other examples such as a wheel type hydraulic excavator, a hydraulic crane, a wheel loader, and the like. It can be widely applied to construction machines.

1 Excavator (construction machine)
5 Turning frame (body frame)
7,42 engine (motor)
7A, 42A flywheel (output shaft)
DESCRIPTION OF SYMBOLS 9 Hydraulic pump 9A Input shaft 10 Coupling 10D Elastic body 11,31 Cooling fan 12 Heat exchanger 13 Coupling case 14 Exterior cover 15 Partition 16 Engine chamber 17 Pump chamber 18, 32, 51 1st ventilation path 18A, 20A, 32A, 33A Opening 19 Filter member 20, 33 Second ventilation path 41 Prime mover 43 Assist electric motor

Claims (4)

The prime mover mounted on the body frame,
A hydraulic pump driven by the prime mover;
A coupling connecting the output shaft of the prime mover and the input shaft of the hydraulic pump to transmit the rotation of the prime mover to the hydraulic pump;
A cooling fan that is provided on the opposite side of the hydraulic pump across the prime mover and generates cooling air for cooling the heat exchanger;
A coupling case which is provided between the prime mover and the hydraulic pump and houses the coupling therein;
An exterior cover provided on the vehicle body frame in a state of covering devices including the prime mover, hydraulic pump, coupling, cooling fan, and heat exchanger;
In a construction machine comprising a partition wall that partitions the interior of the exterior cover into a prime mover chamber in which the prime mover, a cooling fan, and a heat exchanger are accommodated, and a pump chamber in which the hydraulic pump and a coupling are accommodated.
A first air passage is provided in communication between the prime mover chamber and the coupling case;
A second air passage is provided in communication between the pump chamber and the coupling case;
Due to the differential pressure generated between the prime mover chamber and the pump chamber due to the driving of the cooling fan, cooling air flows through the first vent passage and the second vent passage in the coupling case. A featured construction machine.   2. The construction machine according to claim 1, wherein a filter member is provided in the first air passage and the second air passage at an open front end portion. 3. Of the first ventilation path and the second ventilation path, an inflow side ventilation path for allowing cooling air to flow into the coupling case is provided at a lower position of the coupling case,
The construction according to claim 1, wherein an outflow side air passage for allowing cooling air to flow out of the inside of the coupling case is provided at an upper position of the coupling case higher than the inflow side air passage. machine. The prime mover is composed of an engine as an internal combustion engine and an assist electric motor provided in series with the engine located on the hydraulic pump side to assist the engine,
The construction machine according to claim 1, wherein the partition wall is disposed on an outer peripheral side of the coupling case.

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