JP4198301B2 - Engine cooling device for construction machinery - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an engine cooling device provided in an engine room of a construction machine, and more particularly, to an engine cooling device for a construction machine provided with a cooling fan for cooling a heat exchanger such as a radiator.
[0002]
[Prior art]
A construction machine, for example, a hydraulic excavator, operates a front device (working front) such as a boom, an arm, and a bucket and an upper swing body by a hydraulic actuator such as a hydraulic cylinder and a hydraulic motor. These hydraulic actuators are actuated by discharge pressure oil from a hydraulic pump driven by the engine. The upper swing body is covered with a cover, and the engine and the hydraulic pump are arranged in an engine room provided in the cover.
[0003]
Usually, in this type of construction machine, in order to cool the engine, a cooling fan provided in the engine room is driven to introduce outside air from an intake hole provided on one side of the cover to induce cooling air. At this time, as the cooling fan, a so-called axial fan (propeller fan) that is rotated by a driving force from the crankshaft of the engine is often used. After the cooling air is introduced into the engine compartment, it is cooled by passing through various heat exchangers such as a radiator, and is throttled by a shroud provided on the downstream side of the heat exchanger and introduced into the cooling fan. The cooling air blown from the cooling fan is further cooled to the engine, the hydraulic pump, etc., and then discharged to the outside through an exhaust hole provided on the other side of the cover.
[0004]
By the way, the above-described hydraulic pump, engine, cooling fan, and the like generate noise during operation, and this sound flows out from the intake hole and the exhaust hole to the surroundings. In recent years, there has been a strong demand for noise reduction from construction machines to the surroundings based on changes in the work environment and the need to preserve the surrounding environment, and various measures have been conventionally taken for the purpose of reducing this noise. As such a known example, for example, there is an engine cooling device described in JP-A-11-94419.
[0005]
This engine cooling device is provided in an engine room in which an engine of a construction machine is installed, and induces at least one heat exchanger including a radiator that cools cooling water of the engine and cooling air that cools the heat exchanger. In an engine cooling device for a construction machine having a cooling fan and a shroud (wind guide plate) that is fixed to a heat exchanger and introduces cooling air into the cooling fan, a substantially disc-shaped fluid guide plate is provided on the blowing side of the cooling fan. ing.
This structure prevents interference between the main flow of the cooling air induced by the cooling fan in the centrifugal direction and the reverse flow that separates from the main flow and moves toward the center of the cooling fan, thereby preventing the occurrence of turbulence and cooling. Noise generated from the fan can be reduced.
[0006]
[Problems to be solved by the invention]
The above-described known techniques have the following problems.
That is, in general, in this type of construction machine engine cooling device, the rotating shaft of the cooling fan is generally provided in common with the rotating shaft of the water pump for circulating the radiator water disposed in the engine. A pulley is fixed to a portion of the fan rotation shaft between the cooling fan and the engine, and a fan belt is stretched between the pulley and the pulley fixed to the crankshaft of the engine. Is transmitted to the fan rotation shaft through the pulley of the crankshaft, the fan belt, and the pulley of the fan rotation shaft, thereby rotating the cooling fan to induce cooling air. Since this fan belt is worn with use, it is necessary to replace (or maintain) it at an appropriate frequency.
[0007]
Normally, this replacement / maintenance operation is performed while maintaining the ring shape without cutting the fan belt. That is, after removing the fan belt from the pulley of the crankshaft and the pulley of the fan rotation shaft and letting it escape to the anti-engine side, let it pass through the outer peripheral part of each cooling fan blade and pull it further to the anti-engine side. When the outer peripheral portion of the blade is passed, the removal is completed. The reverse procedure is used when installing a new fan belt. Thus, when replacing or maintaining the fan belt, it is necessary to pull out the fan belt to the non-engine side.
[0008]
However, in the above known technique, when the fluid guide plate is provided on the blowout side of the cooling fan (in other words, between the cooling fan and the pulley of the fan rotation shaft), special consideration is given to the above fan belt replacement / maintenance work. The fluid guide plate is fixedly supported from the engine side. Therefore, it becomes difficult to pull out the fan belt due to the fluid guide plate having the fixed structure, which makes it difficult to replace and maintain the fan belt.
[0009]
The present invention has been made in view of the above, and an object thereof is to prevent interference between the cooling air main flow and the reverse flow in the cooling fan, reduce noise, and facilitate the replacement and maintenance work of the fan belt. An object of the present invention is to provide an engine cooling device for construction machinery that can be used.
[0010]
[Means for Solving the Problems]
(1) In order to achieve the above object, the present invention provides at least one heat exchanger including a radiator that is provided in an engine room in which an engine of a construction machine is installed and that cools cooling water of the engine, An engine cooling device for a construction machine having a cooling fan that is rotated by a driving force of an engine and induces cooling air that cools the heat exchanger. The engine cooling device is detachably supported on the engine side and includes the cooling fan. A first shroud and a second shroud that is located upstream of the first shroud and that is supported on the heat exchanger side and introduces the cooling air that has cooled the heat exchanger into the first shroud; An elastic sealing member that seals between the first shroud and the second shroud while allowing relative displacement between the first shroud and the second shroud;A net member for fan protection having a substantially half donut shape provided in the first shroud so as to be located on the blowout side of the cooling fan;Located on the blowout side of the cooling fan,On the downstream side of the cooling air of the mesh memberA first fluid guide plate supported on the first shroud side;The first fluid guide plate has a substantially inverted U shape coaxial with a substantially half donut shape of the mesh member, and the first fluid guide plate passes the rotation shaft of the cooling fan. The provided inner peripheral surface is arranged so as to overlap the inner peripheral surface of the mesh member..
[0011]
In the present invention, the shroud that guides the cooling air that has passed through the heat exchanger to the cooling fan is provided on the upstream side of the first shroud (fan ring) supported on the engine side and including the cooling fan. It is set as the isolation | separation structure with the 2nd shroud (shroud cover) which is located and is supported by the heat exchanger side and introduce | transduces cooling air into a 1st shroud. Then, by connecting and sealing between the first shroud and the second shroud with an elastic sealing member (for example, a rubber ring), the cooling air is passed through various heat exchangers such as a radiator, and then cooled. The second shroud supported on the exchanger side, the elastic sealing member, and the first shroud supported on the engine side can be passed without leakage in order and introduced into the cooling fan.
At this time, a so-called axial fan (propeller fan) is usually used as the cooling fan rotated by the driving force of the engine. In this case, when the cooling air is blown out from the cooling fan, a back flow that separates from the main flow and separates from the main flow toward the center of the cooling fan is generated with respect to the main flow of the cooling air toward the centrifugal direction. In the present invention, by providing the first fluid guide plate on the blowout side of the cooling fan, it is possible to prevent the reverse flow from interfering with the main flow and to generate turbulence, and to reduce the noise generated from the cooling fan.
[0012]
On the other hand, in the present invention, among the shrouds having the separation structure as described above, the first shroud is detachably supported on the engine side, and the first fluid guide plate is attached to the detachable first shroud. Support on the side. Thereby, the first fluid guide plate can also be structured to be removable from the engine side together with the first shroud. As a result, when the fan belt is replaced or maintained, the fan belt can be easily pulled out to the non-engine side by removing the first fluid guide plate together with the first shroud, and the fan belt can be easily replaced and maintained. Can be done.
[0014]
(2) Preferably,Self-ventilated generator provided with power generation means and fan means driven by the power of the engineFurtherHaveIn (1) above,  On the blowing direction blowing side of the fan means of the self-venting generatorProvidedSecond fluid guide plateThe second fluid guide plate is formed by extending the end portion of the first fluid guide plate downward to reach substantially the same height direction position as the self-ventilated generator..
[0015]
In the present invention, cooling air induced by a cooling fan is used to cool through various heat exchangers such as a radiator, and the self-ventilated generator is provided with fan means driven by engine power. Cool the means. At this time, the flow direction of the cooling air in the engine room is so-called that it passes through the heat exchanger, the cooling fan, and the engine in that order because a uniform wind speed is obtained on the front surface of the heat exchanger and the cooling efficiency is excellent. Usually, the suction cooling system is used, and the fan means of the self-ventilating generator is usually the suction cooling system that passes in the order of power generation means → fan means from the same viewpoint as described above.
[0016]
In the present invention, both the cooling fan and the fan means of the self-venting generator are driven by the engine power. In this case, a pulley is provided on the crankshaft projecting to one side of the engine, and the power from this pulley is transmitted to the pulley provided on the rotating shaft of the cooling fan and the pulley provided on the rotating shaft of the fan means for cooling. It is common to drive fans and fan means. In this case, the pulley of the cooling fan rotating shaft and the pulley of the fan means rotating shaft are arranged at positions relatively close to the pulley of the engine crankshaft. As a result, when both the cooling fan and the fan means are in the suction cooling system as described above, the power generation means on the engine side → the engine's side of the engine with respect to the direction of the cooling air flowing by the cooling fan flowing in the direction of the heat exchanger → cooling fan → engine. Since the direction of ventilation by the fan means flowing in the direction of the fan means protruding to one side is the opposite direction, it may be difficult to secure the cooling air volume by the fan means.
[0017]
Therefore, in the present invention, by providing the second fluid guide plate on the ventilation direction blow-out side of the fan means of the self-ventilation type generator, the cooling air from the cooling fan tries to interfere with the cooling air of the fan means. It can block and block its influence. Therefore, it is possible to secure the cooling air amount by the fan means and improve the cooling performance for the power generating means of the self-ventilation type generator.
[0018]
(3)Preferably, the above(2)The flow direction of the cooling air induced by the cooling fan and the direction of the air flow by the fan means of the self-venting generator are opposite to each other.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[0020]
FIG. 2 is a perspective view showing an overall appearance structure of a hydraulic excavator that is an example of a construction machine to which the engine cooling device according to the present embodiment is applied. The hydraulic excavator is roughly described as a lower traveling body 1. An upper revolving body 2 provided on the lower traveling body 1 so as to be able to turn, an operator cab 3 provided on the front left side of the upper revolving body 2, and an engine room 4 disposed horizontally on the upper revolving body 2. And a counterweight 5 provided at the rear of the upper swing body 2 and an articulated front device 6 provided at the front of the upper swing body 2 and including a boom 6a, an arm 6b and a bucket 6c. .
[0021]
The lower traveling body 1 includes an endless track crawler belt 1a on the left and right. Each of the endless track crawler belts 1a is driven by a driving force of a traveling hydraulic motor 1b.
[0022]
An upper swing body 2 including an operator cab 3, an engine compartment 4, a counterweight 5, an articulated front device 6 and the like is a hydraulic hydraulic motor (not shown) for swing provided at the center of the upper swing body 2. Is turned with respect to the lower traveling body 1.
[0023]
The boom 6a, the arm 6b, and the bucket 6c that form the multi-joint type front device 6 are driven and operated by the boom cylinder 7a, the arm cylinder 7b, and the bucket cylinder 7c provided to them.
[0024]
The drive devices (hydraulic actuators) such as the hydraulic cylinders 7a, 7b, 7c, the turning hydraulic motor, and the traveling hydraulic motor 1b described above are responsive to operations from an operation lever operated by an operator in the cab 3. Then, it is driven by pressure oil from a control valve device (not shown) that controls pressure oil from a hydraulic pump (not shown) driven by an engine 8 (not shown, see FIG. 1 described later) in the engine chamber 4. Is done.
[0025]
FIG. 3 is an enlarged perspective view showing the external structure of the engine chamber 4 to which the engine cooling device according to the present embodiment is applied. FIG. 1 is a detail of the engine chamber 4 in which the engine cooling device according to the present embodiment is provided. FIG. 4 is a side sectional view taken along the line II in FIG. 3 showing the structure, and FIG. 4 is an enlarged view of a portion A in FIG. 1, 3, and 4, the same reference numerals as those in FIG. 2 denote the same parts.
[0026]
1, 3, and 4, the engine room 4 includes a heat exchanger 9, a shroud 10 provided on the downstream side of the heat exchanger 9, and cooling air (air) that cools the heat exchanger 9. Flow), a cooling fan 11 for inducing P, a sealing partition member 12 provided on the outer periphery including the upper and lower portions of the heat exchanger 9, and a side portion (front side in FIG. 1) of the engine 8 And an AC generator 28 for supplying power to various electrical components (not shown) of the hydraulic excavator.
The engine chamber 4 is surrounded by an engine cover 13 that covers the engine 8, the cooling fan 11, the heat exchanger 9, a hydraulic pump (described later), a muffler (same), and the like. ing. The engine cover 13 includes a lower cover 13a, a suction side (left side) horizontal cover 13b, a discharge side (right side) horizontal cover 13c, an upper cover 13d, a front cover 13e, and a rear cover 13f. Yes.
[0027]
The upper cover 13d is attached to the discharge side cover 13c so that one end thereof can be opened and closed by a hinge 14, and the other end is provided with a locking tool 15 for latching the opening / closing side to the suction side cover 13b. It has been. And the suction port 16 which takes in the cooling air P from the outside and introduces it into the cooling fan 11 is provided in the heat exchanger 9 side area | region of this upper cover 13d, and the suction side side cover 13b. Further, the other area of the upper cover 13d and the discharge side lateral cover 13c are respectively provided with discharge ports 17 and 18 for discharging the cooling air P flowing out from the cooling fan 11 to the outside. Further, a discharge port 19 is also provided on the hydraulic pump (described later) side of the lower cover 13a.
[0028]
The engine 8 is installed on a frame 20 that is provided below the upper swing body 2 and forms a basic lower structure of the upper swing body 2 via a vibration damping device 21. A pulley 22 is fixed to the crankshaft 8 a of the engine 8. Further, an auxiliary rotary shaft 23 is provided above the crankshaft 8 a of the engine 8 so as to face the engine 8 in common with the shaft of the cooling fan 11. A water pump 24 that circulates engine cooling water through a pipe (not shown) to a radiator 9c (described later) that is one of the heat exchangers 9 is connected to the end of the auxiliary rotating shaft 23 in the engine 8. Yes.
The heat exchanger 9 is disposed upstream (upstream side) of the cooling fan 11, and more specifically, for example, is a compressed compression intake for combustion that is located on the most upstream side in the flow direction of the cooling air P and is supplied to the cylinder head of the engine 8. An intercooler 9a that cools air in advance, an oil cooler 9b that cools the pressure oil (hydraulic oil) that is adjacent to the downstream side of the intercooler 9a and drives the hydraulic actuators 7a to 7c described above, and the oil cooler 9b Further, it is formed with a radiator 9 c that is located on the most downstream side in the flow direction of the cooling air P on the downstream side and cools the cooling water of the engine 8. Note that the size of the intercooler 9a disposed on the uppermost stream side of the cooling air P is similar to that of an ordinary engine cooling device of this type of construction machine depending on the required cooling performance (heat exchange capacity). As shown in FIG. 1, it is smaller than the oil cooler 9b and the radiator 9c, and particularly has a small vertical vertical dimension (vertical direction in FIG. 1).
The intercooler 9a, the oil cooler 9b, and the radiator 9c may all be pipes through which the liquid to be cooled flows, or may be guides that are substantially framed (or two substantially flat plates on both sides). ) Is formed inside. That is, the intercooler 9a includes a pipe 9aA through which combustion air flows and a frame body 9aB that holds the pipe 9aA, the oil cooler 9b includes a pipe 9bA through which hydraulic oil flows and a frame body 9bB that holds the pipe, and the radiator 9c A pipe 9cA through which engine cooling water flows is provided and a frame body 9cB that holds the pipe 9cA. At this time, as shown in FIG. 1, the intercooler frame body 9aB, the oil cooler frame body 9bB, and the radiator frame body 9cB are arranged and fixed so as to be in close contact with each other in the flow direction of the cooling air P. The intercooler pipe 9aA, the oil cooler pipe 9bA, and the radiator frame 9cA are arranged so that there is a slight clearance therebetween in the flow direction of the cooling air P.
[0029]
The shroud 10 is located on the upstream side of the cooling fan 11 and introduces the cooling air P induced by the cooling fan 11 to the suction side of the cooling fan 11 and is fixed to the downstream side of the heat exchanger 9. A substantially box-shaped front part (box shroud or shroud cover) 10a and a substantially bellmouth-shaped rear part (fan ring) located further downstream of the front part 10a and arranged on the radially outer peripheral side of the cooling fan 11 ) 10b and a so-called separation type (two piece type) shroud.
[0030]
That is, as shown in detail in FIG. 4, the front portion 10 a is fixed to the downstream side (right side in FIG. 4) of the cooling air P of the heat exchanger 9 (specifically, the radiator 9 c), while the rear portion 10 b is fixed to the engine 8. It is fixed to a provided bracket (stay) 41.
[0031]
The shroud rear portion 10b is provided with a substantially half donut-shaped ring guard portion (fan protection net) 10b1 for securing safety on the downstream side of the cooling air P. And the mounting bracket part 10b1A is provided in the circumferential direction multiple places (this example three places) of this ring guard part 10b1 so that it may protrude radially, and the through-hole 45 is provided in each mounting bracket part 10b1A. Yes. On the other hand, the number of the brackets 41 corresponding to the ring guard mounting bracket portion 10b1A of the shroud rear portion 10b is arranged from the engine 8 and passed through a through hole 41a formed in the vicinity of the tip portion of each bracket 41. After the mounting bolt 42a is further passed through the through hole 45 of the ring guard mounting bracket portion 10b1A, the mounting nut 42b is fastened so that the shroud rear portion 10b is detachably mounted to the bracket 41.
[0032]
A fluid guide plate 27 is fixed on the downstream side of the cooling air of the ring guard portion 10b1. FIG. 5 shows a detailed structure of the fluid guide plate 27 and the ring guard portion 10b1 as seen from the direction B (downstream side of cooling air) in FIG.
[0033]
As shown in FIG. 5, the fluid guide plate 27 has a substantially inverted U shape coaxial with the half donut shape of the ring guard portion 10 b 1, and an inner peripheral surface 27 a through which the auxiliary rotation shaft 23 is passed, It arrange | positions so that it may overlap with the internal peripheral surface 10b1B of the ring guard part 10b1. The inner diameter of the inner peripheral portion 27a is larger than the diameter of the auxiliary rotating shaft 23, but it is preferable from the viewpoint of air volume and noise to be as close as possible to the diameter of the auxiliary rotating shaft 23.
[0034]
Further, the size of the fluid guide plate 27 may be set to the most preferable value in consideration of the air volume of the cooling air P, the required degree of noise reduction, the mounting of each device in the engine room 4 and the like. However, in the fluid guide plate 27 of the present embodiment, the radial dimension D is made smaller than the outer diameter dimension of the cooling fan 11 (see FIG. 1). Further, both side end portions 27b1 and 27b2 having a substantially inverted U shape are extended downward until reaching substantially the same height direction position as the AC generator 28 (see FIG. 1). The fluid guide plate 27 can be made of, for example, metal or plastic.
[0035]
1, 3, and 4, stoppers 10 ao and 10 bo are provided in the vicinity of the downstream end of the shroud front part 10 a and in the vicinity of the upstream end of the rear part 10 b, respectively. After attaching a sealing member (a shroud rubber bar, rubber ring) 43 formed of an elastic material such as rubber to the portions 10ao and 10bo, a band 44 is provided near the upstream end of the sealing member 43. Tightening and sealing member 43 are prevented from shifting or coming off. With such a structure, during the operation of the cooling fan 11, the chip clearance c (see FIG. 4) between the shroud rear portion 10b and the blade 11b of the cooling fan 11 is made as small as possible to improve the fan performance, and the heat exchanger The front portion 10a and the rear portion 10b are sealed while allowing relative displacement between the shroud front portion 10a belonging to the vibration system on the 9th side and the rear portion 10b belonging to the vibration system on the engine 8 side. . That is, a negative pressure is generated between the cooling fan 11 and the heat exchanger 9, and this becomes a source of the cooling air P passing through the heat exchanger 9. However, if the space is an open space, the negative pressure is reduced and cooling is performed. Since the effect is reduced, the sealing member 43 is provided to prevent this.
[0036]
The cooling fan 11 is a so-called axial fan and is attached to the auxiliary rotating shaft 23. At this time, the pulley 25 is fixed to the auxiliary rotating shaft 23 so as to be in a position corresponding to the pulley 22 of the engine crankshaft 8a. A belt (fan belt) 26 is stretched between the pulley 22 and the pulley 25. The cooling fan 11 includes a boss 11a fixed to the auxiliary rotating shaft 23 to which the driving force from the engine crankshaft 8a is transmitted, and a plurality of blades 11b fixed around the boss 11a. It is rotationally driven by the rotation of the auxiliary rotating shaft 23 to induce (generate) cooling air P (see arrow) in the right direction in FIG.
[0037]
A pulley 32 for transmitting driving force to the AC generator 28 (details will be described later) is separately provided on the auxiliary rotating shaft 23 on the engine 8 side from the pulley 25.
[0038]
6 is a partially enlarged view of FIG. 1 showing the detailed structure of the AC generator 28. The AC generator 28 includes a rotor (not shown) having a rotating shaft 29 and a fan fixed to the rotating shaft 29. Means 30 and a housing 31 containing the rotor are provided.
At this time, a pulley 38 is fixed to the rotary shaft 29 so as to be at a position corresponding to the pulley 32 of the auxiliary rotary shaft 23, and a belt (fan belt) 39 is interposed between the pulley 32 and the pulley 38. It is being handed over. Then, when the rotating shaft 29 is driven to rotate and the fan means 30 rotates, the cooling air Pc for cooling the generator in the left direction in FIGS. 1 and 5 is induced (produced), and by this cooling air Pc, An armature coil (not shown), a field coil, and other various electronic components (diodes, regulators, etc.) inside the housing 31 are air-cooled.
[0039]
Returning to FIG. 1, the partition member 12 seals between the heat exchanger 9 and the upper cover 13d, the lower cover 13a, the front cover 13e, and the rear cover 13f.
[0040]
The above-described hydraulic pump 33 is provided on the discharge side lateral cover 13c side of the engine 8, and this hydraulic pump 33 is connected to the engine 8 via a connection mechanism (coupling) (not shown), and the driving force of the engine 8 is Driven by. Further, the exhaust gas from the engine 8 is silenced by the muffler 34 and then discharged to the outside of the engine room 4 through an exhaust gas pipe (tail pipe) 35. At this time, a muffler cover 36 is fixed to the upper part of the engine 8 so as to prevent oil from scattering from the hydraulic pump 33 to the engine 8 side. A battery 37 for supplying a starting current for the engine 8 is disposed upstream of the heat exchanger 9 in the engine room 4 (left side in FIG. 1).
[0041]
In the above, the shroud rear portion 10b is detachably supported on the engine side described in each claim, and constitutes a first shroud including a cooling fan, and the shroud front portion 10a is located upstream of the first shroud. And a second shroud for introducing the cooling air supported on the heat exchanger side and cooling the heat exchanger into the first shroud, and the sealing member 43 includes the first shroud and the second shroud. The elastic sealing member which seals between them is comprised, accept | permitting relative displacement with.
In addition, the fluid guide plate 27 is located on the blowout side of the cooling fan and constitutes a first fluid guide plate supported on the first shroud side, of which the end 27b1 is a fan of the self-ventilating generator It also constitutes a second fluid guide plate provided on the side in the ventilation direction of the means. Further, the ring guard portion 10b1 constitutes a net member provided on the first shroud so as to be positioned on the blowing side of the cooling fan.
[0042]
Next, the operation of the engine cooling device according to the present embodiment will be described.
When the engine 8 is driven during hydraulic excavator work, the rotation of the crankshaft 8 a is transmitted to the auxiliary rotating shaft 23 via the pulley 22, the belt 26, and the pulley 25. As a result, the water pump 24 is driven to circulate the cooling water of the radiator 9c, and the cooling fan 11 is driven to rotate. By the rotation of the cooling fan 11, air outside the cover 13 is introduced into the engine chamber 4 from the suction port 16 and flows into the cooling chamber P from the upstream side to enter the heat exchanger 9 (intercooler 9a, oil cooler 9b, And the radiator 9c) are sequentially cooled and then throttled through the inside of the shrouds 10a and 10b on the downstream side of the heat exchanger 9, and introduced to the suction side (left side in FIG. 1) of the cooling fan 11 (so-called Suction cooling method). Thereafter, the cooling air P blown from the cooling fan 11 cools the engine 8, the hydraulic pump 33, and the like on the downstream side of the cooling fan 11, and is then discharged from the discharge ports 17, 18, 19 to the outside of the engine chamber 4. The
[0043]
The rotation of the auxiliary rotating shaft 23 is transmitted to the rotating shaft 29 of the AC generator 28 via the pulley 32, the belt 39 and the pulley 38. The rotation of the rotating shaft 29 causes the rotor to rotate to generate electric power, supplying power to various electrical components (not shown) of the hydraulic excavator, the fan means 30 to rotate, and the cooling air Pc to be supplied to the armature in the housing 31. A coil (not shown), a field coil, and other various electronic components (diodes, regulators, etc.) are cooled and then flow into the fan means 30 (so-called suction cooling system).
[0044]
The operation of the present embodiment as described above will be sequentially described below.
[0045]
(1) Noise reduction by preventing interference with separated backflow
As described above, the cooling air P is blown out to the engine 8 side by the cooling fan 11. Here, the cooling fan 11 is an axial fan. However, at a fan operating point (low flow rate, high pressure) in a normal hydraulic excavator, the cooling fan 11 is squeezed in the radial direction by the shroud 10 and the sealing degree in the engine chamber 4 is low. By being high, the cooling air P blown from the cooling fan 11 flows out mainly in the centrifugal direction (see P0 described later).
[0046]
Here, when there is no fluid guide plate 27, the main flow P0 (see FIG. 1) of the cooling air P generated in the centrifugal direction on the blow-out side of the cooling fan 11 and the main flow P0 are separated from the main flow P0 radially inward. A reverse flow (an example P1 of which is indicated by a broken line in FIG. 1) that attempts to return from the vicinity of the auxiliary rotating shaft 23 toward the radiator 9c interferes with each other, thereby causing a disturbance and increasing noise. Therefore, in the present embodiment, by providing the fluid guide plate 27, the backflow P1 can be prevented from interfering with the main flow P0 in the centrifugal direction, and the occurrence of turbulence can be prevented, so noise generated from the cooling fan 11 can be prevented. Can be reduced.
[0047]
(2) Action by detachable structure of fluid guide plate
Although the inside of the engine compartment 4 is cooled by the cooling fan 11 as described above, the belt 26 formed of an elastic member is worn over time with use. Therefore, replacement or maintenance is performed at an appropriate frequency. In this case, first, after removing the mounting nut 42b fastened to the mounting bolt 42a, the sealing member 43 locked to the stopper portion 10bo in the vicinity of the upstream end of the shroud rear portion 10b is removed, and the shroud rear portion 10b and the fluid are removed. The guide plate 27 is removed as a unit.
[0048]
After that, the belt 26 is removed from the pulley 22 of the crankshaft 8a of the engine 8 and the pulley 25 of the auxiliary rotating shaft 23 and is allowed to escape to the non-engine 8 side (left side in FIG. 1). Take out to the side opposite to the engine 8 through the clearance c. Thereafter, the other portions of the belt 26 are sequentially taken out to the side opposite to the engine 8 through the tip clearance c. In this way, when the outer peripheral portions of all the blades 11b have been passed, the removal of the belt 26 is completed. Thereafter, a new belt (or a belt after repair) 26 is attached in the reverse procedure. After the belt 26 is attached, the replacement / maintenance work of the belt 26 is completed if the rear portion 10b of the shroud and the fluid guide plate 27 are fastened and fixed with the attaching bolt 42a and the attaching nut 42b.
[0049]
As described above, by removing the fluid guide plate 27 together with the shroud rear portion 10b, the belt 26 can be easily pulled out to the anti-engine 8 side, so that belt replacement and maintenance work can be easily performed.
[0050]
The belt 39 for cooling the AC generator 28 may be replaced and maintained in the same manner as the belt 26. In this case, the same effect can be obtained.
[0051]
(3) Action to improve AC generator cooling
In the present embodiment, both the cooling fan 11 and the fan means 30 of the self-ventilating generator 28 are driven by the driving force from the crankshaft 8 a of the engine 8. Therefore, the driving force from the pulley 22 provided on the crankshaft 8a protruding to one side (left side in FIG. 1) of the engine 8 is applied to the pulley 25 provided on the auxiliary rotating shaft 23 and further to the self-ventilated generator rotating shaft 29. The cooling fan 11 and the fan means 30 are respectively driven by being transmitted to the provided pulley 38. Due to such a structure, as shown in FIG. 1, the pulley 25 of the auxiliary rotating shaft 23 and the pulley 38 of the self-ventilated generator rotating shaft 29 are arranged at positions relatively close to the pulley 22 of the engine crankshaft 8a. Is done. As a result, when the cooling fan 11 and the fan means 30 are both sucked and cooled as in the present embodiment, the flow direction of the cooling air P by the cooling fan 11 flowing in the direction of the heat exchanger 9 → the cooling fan 11 → the engine 8. And the cooling air Pc generated by the fan means 30 flowing in the direction of the fan means 30 projecting toward one side (left side in FIGS. 1 and 6) of the power generation means in the casing 31 in opposite directions (opposite directions). ) At this time, since the wind pressure of the cooling air P is larger than that of the cooling air Pc, it is difficult to secure the air volume of the cooling air Pc as it is, and there is a possibility that the cooling performance of the self-ventilated AC generator 28 is lowered.
[0052]
Therefore, in the present embodiment, the end 27b1 of the fluid guide plate 27 is extended to almost the same height direction as the fan means 30 of the self-ventilating generator 28, and the upstream side of the cooling air P of the fan means 30 is disposed. Cover (in other words, be located on the side of the fan means 30 where the cooling air Pc is blown out). Thereby, it is possible to partition and block the cooling air P from the cooling fan 11 from interfering with the cooling air Pc of the fan means 30 and to block the influence. Therefore, it is possible to secure the air volume of the cooling air Pc by the fan unit 30 and improve the cooling performance of the self-ventilated generator 28 with respect to the power generating unit.
[0053]
(4) Improvement of fan efficiency
In the present embodiment, as the shroud 10, a so-called separation type (two-piece type) shroud composed of 10 a fixed to the downstream side of the heat exchanger 9 and a rear portion 10 b fixed to the engine 8 side is used. The shroud rear portion 10b that includes the cooling fan 11 is disposed in the same vibration system on the engine 8 side as the cooling fan 11. As a result, the relative displacement between the shroud and the cooling fan is reduced as compared with the case where the part including the cooling fan, such as a non-separable (integrated) shroud, also belongs to a vibration system different from the engine 8. Thereby, since the chip clearance c can be set small in advance, the fan efficiency of the cooling fan 11 can be improved.
[0054]
As described above, according to the engine cooling apparatus of the present embodiment, it is possible to reduce the noise by preventing interference between the cooling wind main flow P0 and the backflow P1 in the cooling fan 11, and the replacement of the belts 26 and 39. Maintenance work can be easily performed.
[0055]
  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.The
[0056]
  For example, FIG.When using fluid guide plates 27 of different shapesFIG.It is the figure which looked at the structure of the fluid guide plate 27A and the ring guard part 10b1 from the cooling air P downstream side, and is a figure equivalent to the above-mentioned FIG. 5 (however, the mounting bracket part 10b1A is not shown). In FIG. 7, the fluid guide plate 27A according to this modified example has the right end portion 27b2 in FIG. 5 out of the substantially U-shaped side end portions 27b1 and 27b2 of the fluid guide plate 27 shown in FIG. Structure. For example, it corresponds to a case where some devices, parts, structures, etc. are arranged at the position of the end portion 27b2 due to the mounting of each device in the engine chamber 4, and the fluid guide plate 27 cannot be extended. It is a thing. At this time, since the end 27b1 covering the upstream side of the fan means 30 of the self-ventilating AC generator 28 is secured, the same effect as in the above embodiment can be obtained.
[0057]
In addition to the above, when the mounting position of the self-ventilation type AC generator 28 on the side of the engine 8 is changed and the self-ventilation type AC generator 28 is arranged on the front side in FIG. For example, as shown in FIG. 8, a fluid guide plate 27A ′ having an end portion 27b1 ′ extended to cover the upstream portion of the fan means 30 of the self-ventilating AC generator 28 may be used.
[0058]
  FIG. 9 shows a reference example.When a fluid guide plate is also provided in the self-ventilated AC generatorIt is a figure showing the configuration ofIt is a figure showing the detailed structure of AC generator 28A which is a principal part, and is a figure equivalent to the above-mentioned FIG. In FIG. 9, the bookReference exampleThen, instead of the above-described AC generator 28, an AC generator 28A provided with, for example, a circular fluid guide plate 40 is arranged on the blowing direction blowing side (downstream of the cooling air Pc) of the fan means 30 of the self-ventilating generator 28. It is a thing. At this time, through holes 31aA are formed in tongues (brackets) 31a provided at a plurality of locations on the outer peripheral side of the housing 31, and through holes 40a are also formed at positions corresponding to the through holes 31aA in the fluid guide plate 40. The fluid guide plate 40 is detachably fixed to the housing 31 by passing the mounting bolts 46a through the through holes 31aA and the through holes 40a and tightening the three nuts 46b.
[0059]
  In addition, thisReference exampleThen, the end portion 27b1 of the fluid guide plate 27, the fluid guide plate 40,ButA second fluid guide plate provided on the ventilation direction blow-out side of the fan means of the self-venting generator is configured.
[0060]
  BookReference exampleAccording to the above, by covering the upstream side of the cooling air P of the fan means 30 with the fluid guide plate 40 in addition to the fluid guide plate end portion 27b1, the air volume of the cooling air Pc by the fan means 30 can be secured more reliably. The cooling performance for the power generation means of the self-venting generator 28A can be further improved. At this time, at the time of replacement / maintenance work of the belt 39, the fluid guide plate 40 can be easily removed by loosening the mounting bolt 47a and the nut 47b, so that the replacement / maintenance work of the belt 39 can be easily performed.
[0061]
From the viewpoint of improving the cooling performance of the self-venting generator 28A with respect to the power generation means, the fluid guide plate 27 may be omitted and the fluid guide plate 40 may be provided only in the self-venting generator 28A. Needless to say.
[0062]
In the above description, the case where the present invention is applied to the engine cooling apparatus in which the intercooler 9a, the oil cooler 9b, and the radiator 9c are disposed as the heat exchanger 9 has been described as an example. However, the present invention is not limited thereto. Needless to say, the present invention can also be applied to a case where only an intercooler and a radiator are arranged as a heat exchanger. The heat exchanger is not limited to these three types. For example, if necessary, an air conditioner condenser 9d (see a two-dot chain line in FIG. 1) provided in the cab 3 is arranged and cooled by the cooling air P. May be.
[0063]
Furthermore, although the above demonstrated taking the case where this invention was applied to the engine room of the hydraulic shovel as an example, it is not restricted to this, It applies to the engine room of other construction machines, such as a crane, a self-propelled crusher, and a wheel loader. May be. In these cases, it goes without saying that the same effect can be obtained.
[0064]
【The invention's effect】
Claim1According to the described invention, since the first fluid guide plate is supported on the detachable first shroud side, the first fluid guide plate is removed together with the first shroud at the time of replacement / maintenance of the fan belt. Thus, the fan belt can be easily pulled out to the non-engine side, and the fan belt can be easily replaced and maintained. Further, the shroud has a first shroud including the cooling fan by separating the first shroud supported on the engine side and including the cooling fan from the second shroud supported on the heat exchanger side. Belongs to the engine-side vibration system like the cooling fan, and the relative displacement between the two becomes small and the chip clearance can be reduced, so that the fan efficiency can be improved and the noise can be reduced.
[0065]
Claims 2 and 3Since the second fluid guide plate is provided on the ventilation direction blow-out side of the fan means of the self-ventilation type generator, the cooling air from the cooling fan tends to interfere with the cooling air of the fan means. It can block and block its influence. Therefore, it is possible to secure the cooling air amount by the fan means and improve the cooling performance for the power generating means of the self-ventilation type generator.
[Brief description of the drawings]
FIG. 1 is a diagram showing a detailed structure of an engine room provided with an engine cooling device according to an embodiment of the present invention.
FIG. 2 is a perspective view showing an overall appearance structure of a hydraulic excavator that is an example of a construction machine to which the engine cooling device shown in FIG. 1 is applied.
FIG. 3 is an enlarged perspective view showing an external structure of an engine room to which the engine cooling device shown in FIG. 1 is applied.
FIG. 4 is an enlarged view of a part A in FIG.
5 is a diagram showing a detailed structure of a fluid guide plate and a ring guard portion as viewed from a direction B in FIG. 4 (downstream side of cooling air).
6 is a partially enlarged view of FIG. 1 showing a detailed structure of the AC generator.
FIG. 7 is a view of the structure of a fluid guide plate and a ring guard portion according to a modification using fluid guide plates having different shapes as viewed from the cooling air downstream side.
FIG. 8 is a view of the structure of the fluid guide plate and the ring guard portion, which are extended at the ends to cover the upstream portion of the fan means of the self-ventilated AC generator, as viewed from the cooling air downstream side.
[Fig. 9] A self-ventilating AC generator is also provided with a fluid guide plate.Reference exampleIt is a figure showing the detailed structure of the AC generator which is the principal part of.
[Explanation of symbols]
4 Engine compartment
8 engine
9 Heat exchanger
9c Radiator
10a shroud front (second shroud)
10b Rear shroud (first shroud)
10b Ring guard (net member)
10b 1 A Mounting bracket
11 Cooling fan
27 Fluid guide plate (first fluid guide plate)
27b1 end (second fluid guide plate)
28 Self-venting generator
30 Fan means
40 Fluid guide plate (second fluid guide plate)
43 Sealing member (elastic sealing member)
P Cooling air
Cooling air inside the Pc generator

Claims (3)

At least one heat exchanger provided in an engine room in which an engine of a construction machine is installed, including a radiator that cools the cooling water of the engine, and rotated by the driving force of the engine to cool the heat exchanger In an engine cooling device for a construction machine having a cooling fan for inducing cooling air,
A first shroud supported detachably on the engine side and enclosing the cooling fan;
A second shroud that is positioned upstream of the first shroud and that is supported on the heat exchanger side and that cools the heat exchanger and introduces the cooling air into the first shroud;
An elastic sealing member that seals between the first shroud and the second shroud while allowing relative displacement between the first shroud and the second shroud;
A net member for fan protection having a substantially half donut shape provided in the first shroud so as to be located on the blowout side of the cooling fan;
A first fluid guide plate located on the blowout side of the cooling fan and supported on the first shroud side on the cooling air downstream side of the mesh member ;
The first fluid guide plate has a substantially inverted U shape coaxial with a substantially half donut shape of the mesh member,
The engine cooling of a construction machine, wherein the first fluid guide plate is disposed such that an inner peripheral surface provided for passing a rotating shaft of the cooling fan overlaps with an inner peripheral surface of the mesh member. apparatus. The engine cooling device for a construction machine according to claim 1 , further comprising a self-ventilated generator including a power generation means and a fan means driven by power of the engine.
A second fluid guide plate provided on the side of the fan means of the self-ventilating generator on the blowing direction blowing side ;
The second fluid guide plate is formed by extending an end portion of the first fluid guide plate downward until reaching an almost same height direction position as the self-ventilated generator. Engine cooling device for construction machinery. The engine cooling device for a construction machine according to claim 2 , wherein the flow direction of the cooling air induced by the cooling fan and the air flow direction by the fan means of the self-venting generator are opposite to each other. Engine cooling device for construction machinery.

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