JP7025307B2 - Construction machinery - Google Patents

Description

The present invention relates to a construction machine, and more particularly to a construction machine in which an exhaust gas aftertreatment device for purifying engine exhaust gas is housed in a machine chamber.

In construction machinery such as hydraulic excavators and cranes, various devices such as engines and hydraulic pumps are housed in the machine room (engine room). In order to prevent overheating of these devices, it is necessary to appropriately discharge the waste heat from the engine or the like to the outside of the machine room. In the machine room of a construction machine, various devices are generally cooled by flowing the cooling air generated by the cooling fan from one side to the other side of the machine room and discharging it to the outside.

As a conventional technique for cooling an engine or the like in a machine room, for example, there is one described in Patent Document 1. In the engine room structure of the work machine described in Patent Document 1, the sound absorbing material and the outer periphery of the sound absorbing material are covered in order to reduce the noise in the machine room while ensuring the flowability of the cooling air in the engine room with a simple configuration. A rectifying plate that is integrally compression-molded with the outer skin material is fixed at intervals to the ceiling and bottom of the engine room at the top and bottom of the engine, and cooling air flows between the ceiling and bottom and the rectifying plate. It forms a flow path. In addition, it is molded from the periphery (upper or lower) of the exhaust muffler connected to the engine to the downstream side of the cooling air according to the outer shape of the engine room and the shape of the hydraulic pump located below the exhaust muffler. The muffler rectifying plate is fixed.

Japanese Unexamined Patent Publication No. 2010-55891

By the way, in some construction machines equipped with an engine as a prime mover, an exhaust gas aftertreatment device for removing harmful substances contained in the exhaust gas of the engine is housed in the machine room in order to comply with the exhaust gas regulation of the engine. As the exhaust gas aftertreatment device, a PM collection device that collects particulate matter (PM: Particulate Matter) contained in the exhaust gas, a NOx purification device that purifies nitrogen oxides (NOx), and the like are used. Such an exhaust gas aftertreatment device includes various devices such as a temperature sensor for detecting the temperature of the exhaust gas and a NOx concentration sensor for detecting the NOx concentration in the exhaust gas. These devices are arranged around the main body portion of the exhaust gas aftertreatment device through which the exhaust gas flows. In order for the exhaust gas aftertreatment device to operate normally, it is necessary to prevent an excessive temperature rise of the device due to waste heat from the engine or the exhaust gas aftertreatment device.

In the engine room structure of the work machine described in Patent Document 1, when the cooling fan is operating, the cooling air generated by the cooling fan is provided on the side surface or the ceiling surface of the engine room near the exhaust muffler by the muffler rectifying plate. Since it is guided to the opening, the heat of the engine and exhaust muffler is efficiently discharged to the outside. Therefore, the temperature around the exhaust muffler having the exhaust gas purification function similar to the above-mentioned exhaust gas aftertreatment device does not rise excessively.

On the other hand, when the engine and cooling fan are stopped after the work is completed, the difference in density between the ambient air such as the high temperature engine and exhaust muffler in the engine room and the air outside the engine room (outside air) causes the engine room to be abbreviated. Vertical upward natural convection occurs. In this case, it is difficult to efficiently discharge the heat in the engine room to the outside through the opening on the side surface of the engine room that opens in a direction substantially orthogonal to the direction of natural convection. In addition, heat in the engine room is discharged to the outside from the opening of the ceiling surface that opens in the same direction as the direction of natural convection, but the opening of the ceiling surface is due to the presence of the exhaust stack of the exhaust muffler. , There is a risk that the opening area cannot be sufficiently secured. With natural convection, which has a weaker driving force than forced convection by a cooling fan, heat in the engine room cannot be efficiently discharged to the outside through an opening on the ceiling surface where the opening area is insufficient. As described above, when the cooling fan is stopped, the heat in the engine room cannot be efficiently discharged to the outside, and the temperature around the exhaust muffler may rise excessively.

The present invention has been made based on the above matters, and an object of the present invention is to provide a construction machine capable of preventing an excessive temperature rise when the cooling fan of the equipment provided in the exhaust gas aftertreatment device housed in the machine room is stopped. To provide.

The present application includes a plurality of means for solving the above problems, for example, a machine room having an outer shell formed by a machine room cover, an engine housed in the machine room, and an upper part of the machine room. An exhaust gas aftertreatment device that purifies the exhaust gas of the engine, a hydraulic pump that is arranged below the exhaust gas aftertreatment device in the machine room and is driven by the engine, and a hydraulic pump that is housed and cooled in the machine room. In a construction machine provided with a cooling fan that generates wind and a partition wall that separates the exhaust gas aftertreatment device and the hydraulic pump in the machine room, the machine room cover covers the upper part of the exhaust gas aftertreatment device and is described. A first cover portion having a first opening capable of discharging the cooling air generated by the cooling fan, and a second opening portion capable of discharging the cooling air generated by the cooling fan, covering the sides of the exhaust gas aftertreatment device. A ventilation path between the exhaust gas aftertreatment device and the partition wall and between the exhaust gas aftertreatment device and the second cover portion, including a second cover portion having a It is characterized by further including a barrier portion that obstructs the flow of air to the second opening of the ventilation path.

According to the present invention, by arranging the barrier portion in the ventilation passage, the air flow to the second opening of the ventilation passage when the cooling fan is stopped is obstructed. A part of the flow in the vicinity of the opening can be discharged from the second opening to the outside of the machine room so as to substantially coincide with the opening direction of the second opening. Therefore, the heat in the machine chamber can be efficiently discharged to the outside from the first opening and the second opening, and an excessive temperature rise of the equipment provided in the exhaust gas aftertreatment device can be prevented.

It is a side view which shows the hydraulic excavator as an embodiment of the construction machine of this invention. It is a perspective view which shows the upper swing body of the hydraulic excavator shown in FIG. FIG. 1 is a cross-sectional view of the machine room of the upper swivel body according to the embodiment of the construction machine of the present invention shown in FIG. 1 as viewed from the arrow III-III. FIG. 3 is a perspective view showing the internal structure of the machine room shown in FIG. 3 in a state where the covers on both sides of the machine room and the upper cover are omitted. It is a perspective view which shows the outer shell of the machine room in the upper swing body shown in FIG. It is sectional drawing which shows the internal structure of the machine room of the conventional hydraulic excavator as a comparative example with respect to one Embodiment of the construction machine of this invention. It is sectional drawing which shows the internal structure of the machine room in the 1st modification of the 1st Embodiment of the construction machine of this invention. It is sectional drawing which shows the internal structure of the machine room in the 2nd modification of one Embodiment of the construction machine of this invention. It is sectional drawing which shows the internal structure of the machine room in the 3rd modification of one Embodiment of the construction machine of this invention. It is sectional drawing which shows the internal structure of the machine room in the 4th modification of one Embodiment of the construction machine of this invention. It is sectional drawing which shows the internal structure of the machine room in the 5th modification of one Embodiment of the construction machine of this invention. It is sectional drawing which shows the internal structure of the machine room in the 6th modification of one Embodiment of the construction machine of this invention. It is sectional drawing which shows the internal structure of the machine room in the 7th modification of one Embodiment of the construction machine of this invention. It is sectional drawing which shows an example of the installation position of the plurality of barrier portions in the internal structure of the machine room of the other embodiment of the construction machine of this invention.

Hereinafter, embodiments of the construction machine of the present invention will be described with reference to the drawings. In the present embodiment, a hydraulic excavator will be described as an example of a construction machine. In the following, the front-back and left-right directions will be described with reference to the operator seated in the driver's seat.
First, the configuration of the hydraulic excavator, which is an embodiment of the construction machine of the present invention, will be described with reference to FIGS. 1 and 2. FIG. 1 is a side view showing a hydraulic excavator as an embodiment of the construction machine of the present invention, and FIG. 2 is a perspective view showing an upper swing body of the hydraulic excavator shown in FIG. The left-right direction in FIG. 1 is the front-rear direction of the hydraulic excavator.

In FIG. 1, the hydraulic excavator 1 is a self-propelled crawler type lower traveling body 2, an upper turning body 3 mounted on the lower traveling body 2 so as to be able to turn, and a depression / elevation movement at the front end portion of the upper turning body 3. It is roughly composed of a work front 4 provided as possible.

The lower traveling body 2 includes a track frame 6 and left and right drive wheels 7 rotatably supported by a rear end portion (right end portion in FIG. 1) of the track frame 6 and driven by a hydraulic motor (not shown). , The left and right idle wheels 8 rotatably supported by the front end portion (left end portion in FIG. 1) of the track frame 6, and the cuffs 9 hung around the drive wheels 7 and the idle wheels 8 are provided.

The work front 4 is, for example, an articulated actuating device for performing excavation work and the like, and includes a boom 11, an arm 12, and a bucket 13. The base end side of the boom 11 is rotatably connected to the front end portion of the upper swing body 3. A base end portion of the arm 12 is rotatably connected to the tip end portion of the boom 11. The base end portion of the bucket 13 is rotatably connected to the tip end portion of the arm 12. The boom 11, arm 12, and bucket 13 are rotated by the boom cylinder 11a, arm cylinder 12a, and bucket cylinder 13a, respectively.

As shown in FIGS. 1 and 2, the upper swivel body 3 includes a swivel frame 15 mounted on the lower traveling body 2 so as to be swivel, a cab 16 installed on the left front side on the swivel frame 15, and a swivel frame. The fuel tank 17 and the hydraulic oil tank 18 arranged on the right side of the 15 are arranged between the counterweight 19 attached to the rear end of the swivel frame 15 and the cab 16 and the counterweight 19 in the swivel frame 15. It is configured to include the machine room 20 and the machine room 20. The cab 16 is provided with various operating devices (not shown) for operating the operator's seat (not shown), the work front 4, and the like. The counterweight 19 is for balancing the weight with the work front 4. The machine room 20 accommodates various devices, although details will be described later.

Next, the configurations of various devices housed in the machine room of the hydraulic excavator and the outer shell of the machine room, which are one embodiment of the construction machine of the present invention, will be described with reference to FIGS. 2 to 5. FIG. 3 is a cross-sectional view of the machine room of the upper swivel body in one embodiment of the construction machine of the present invention shown in FIG. 1 as viewed from the arrow III-III, and FIG. 4 is a machine showing the internal structure of the machine room shown in FIG. A perspective view showing a state in which the covers on both sides of the chamber and the upper cover are omitted, and FIG. 5 is a perspective view showing the outer shell of the machine room in the upper swivel body shown in FIG. The left-right direction in FIGS. 3 to 5 is the left-right direction of the hydraulic excavator.

As shown in FIGS. 3 and 4, the machine room 20 houses a large number of devices such as an engine 22, an exhaust gas aftertreatment device 23, a hydraulic pump 24, a cooling fan 25, and a heat exchange device 26. These devices are mounted on a swivel frame 15 located at the lower end of the machine room 20. The swivel frame 15 is a support structure composed of a plurality of frames, and includes a left tail frame 15a and a right tail frame 15b that are juxtaposed at regular intervals in the left-right direction and extend in the front-rear direction. The left tail frame 15a and the right tail frame 15b also have a function of supporting the counterweight 19 (see FIG. 2).

The engine 22 as a prime mover is arranged in a horizontal position in which the output shaft extends in the left-right direction, and is supported by the left tail frame 15a and the right tail frame 15b. The engine 22 is provided with an oil pan 22a at its lower end. The oil pan 22a is arranged between the left tail frame 15a and the right tail frame 15b. An exhaust pipe 28 for exhausting exhaust gas is connected to the engine 22.

An exhaust gas aftertreatment device 23 that purifies the exhaust gas of the engine 22 is connected to the exhaust pipe 28. The exhaust gas aftertreatment device 23 is arranged above the machine room 20 adjacent to the right side of the engine 22. The exhaust gas aftertreatment device 23 is arranged in, for example, a PM collecting device 41 that collects particulate matter (Particulate Matter) generated by combustion in the engine 22 and a downstream side of the PM collecting device 41, and is contained in the exhaust gas. It is composed of a NOx purifying device 42 that purifies the contained nitrogen oxides (NOx). The NOx purifying device 42 is arranged diagonally upward to the right with a gap from the PM collecting device 41, for example, and is closer to the side opening 64a of the engine cover 57 described later than the PM collecting device 41. positioned.

The PM collection device 41 has a PM collection filter and an oxidation catalyst (DOC) (not shown) arranged inside a cylindrical container connected to the downstream end of the exhaust pipe 28 and extending in the front-rear direction. The PM collection filter collects PM contained in the exhaust gas. DOC is a catalyst that oxidizes nitric oxide (NO), carbonization monoxide (CO), hydrocarbon (HC), etc. in exhaust gas. The PM collecting device 41 includes an exhaust gas temperature sensor 44 that detects the temperature of the exhaust gas. The exhaust gas temperature sensor 44 is arranged around the tubular housing of the PM collecting device 41, and is preferably installed at a position opposite to the partition wall 70 side (engine 22 side) described later. One of the causes of failure of the exhaust gas temperature sensor 44 is exposure to a state higher than a predetermined temperature.

In the PM collecting device 41, a large amount of unburned fuel (HC) is contained in a cylindrical body by injecting fuel into the engine 22 (after main injection) and then injecting fuel into the engine 22 again (post-injection). Is discharged to. Since this unburned fuel is oxidized by the DOC, heat of oxidation is generated in the DOC and the temperature of the exhaust gas rises. Particulate matter deposited on the PM collection filter is incinerated and removed by the heated exhaust gas, and the PM collection filter is regenerated. The operation of the PM collecting device 41 is controlled by using the measurement data of the exhaust gas temperature sensor 44 or the like.

The NOx purifying device 42 purifies nitrogen oxides (NOx) in the exhaust gas by using, for example, a liquid reducing agent. The NOx purifying device 42 has a reduction catalyst and an oxidation catalyst (both not shown) arranged inside a cylindrical container connected to the downstream side of the PM collecting device 41 and extending in the front-rear direction. A reducing agent supply device 46 for injecting a reducing agent is provided on the upstream side of the reduction catalyst. The NOx purifying device 42 includes a NOx sensor 47 that detects the NOx concentration in the exhaust gas. The NOx sensor 47 is arranged around the tubular housing of the NOx purification device 42, and is preferably installed at a position opposite to the partition wall 70 side (engine 22 side) described later. One of the causes of failure of the reducing agent supply device 46 and the NOx sensor 47 is exposure to a state higher than a predetermined temperature. An outflow pipe 29 is provided on the downstream side of the NOx purification device 42.

In the NOx purification device 42, the reducing agent injected into the exhaust gas by the reducing agent supply device 46 is adsorbed by the reduction catalyst and reacts with the nitrogen oxides in the exhaust gas. The reducing agent that cannot completely react with the nitrogen oxide in this reaction is oxidized and decomposed by the oxidation catalyst. The operation of the NOx purification device 42 is controlled by using the measurement data of the NOx sensor 47, the reducing agent supply device 46, and the like.

A hydraulic pump 24 is connected to the engine 22 via a power transmission device 31, and the hydraulic pump 24 is supported by the engine 22. The hydraulic pump 24 is arranged in the machine room 20 on the right side of the engine 22 and below the exhaust gas aftertreatment device 23. The hydraulic pump 24 is driven by the engine 22 to suck in the hydraulic oil in the hydraulic oil tank 18 (see FIG. 2), and the cylinders 11a, 12a, 13a (see FIG. 1) of the work front 4 and the lower traveling body. 2 (See FIG. 1) supplies hydraulic oil to a hydraulic actuator such as a traveling hydraulic motor (not shown).

A cooling fan 25 and a heat exchange device 26 as cooling devices are arranged on the left side of the engine 22. The cooling device is for releasing the heat generated in the hydraulic system including the hydraulic pump 24 and the cylinders 11a, 12a, 13a (see FIG. 1) of the work front 4 and the engine 22 to the outside of the machine room 20.

The cooling fan 25 is arranged on the side opposite to the hydraulic pump 24 and the exhaust gas aftertreatment device 23 with the engine 22 interposed therebetween. The cooling fan 25 is, for example, an axial fan having a plurality of blade portions 25a arranged in the circumferential direction. The cooling fan 25 is rotationally driven by the engine 22 to take in outside air into the machine room 20 and generate cooling air flowing from the left side to the right side of the machine room 20.

A heat exchange device 26 is arranged on the suction side (left side) of the cooling fan 25 so as to face the cooling fan 25. The heat exchange device 26 is composed of, for example, a radiator, an oil cooler, or the like, and is used as a cooling water or a hydraulic system for cooling the engine 22 by the outside air (cooling air) taken into the machine chamber 20 by the cooling fan 25. Cools the flowing fluid such as hydraulic oil.

A partition plate 33 is provided on the outer peripheral portion of the heat exchange device 26 to prevent the cooling air discharged from the cooling fan 25 from flowing back to the suction side. A shroud 34 extending toward the outer peripheral side of the wing portion 25a of the cooling fan 25 is attached to the partition plate 33. The shroud 34 is for smoothly introducing the outside air taken into the machine room 20 to the cooling fan 25.

The machine room 20 has an outer shell formed by a machine room cover 50 that surrounds various devices such as an engine 22, an exhaust gas aftertreatment device 23, a hydraulic pump 24, a cooling fan 25, and a heat exchange device 26. The machine room cover 50 is formed in a box shape that opens rearward, for example, as shown in FIG. Specifically, as shown in FIGS. 3 and 5, the machine room cover 50 includes a lower cover 51 provided at the lower end positions of the left tail frame 15a and the right tail frame 15b, and the lower cover 51. The left side cover 52 erected on the left end side, the right side cover 53 erected on the right end side of the lower cover 51, and the left side cover 52 erected on the front end side of the lower cover 51. It is composed of a front cover 54 extending in the left-right direction between the front end portion of the right side cover 53 and the front end portion of the right side cover 53, and an upper cover 55 covering the left and right side covers 52, 53 and the front cover 54 from above. ing. The rear opening of the machine room cover 50 is closed by the counterweight 19 as shown in FIG.

As shown in FIG. 3, the lower cover 51 is provided with a lower first opening 51a at a position between the left tail frame 15a and the right tail frame 15b. Further, a lower second opening 51b is provided at a position on the right side cover 53 side of the right tail frame 15b.

The left side cover 52 and the right side cover 53 face the heat exchange device 26 and the hydraulic pump 24, respectively. The left side cover 52 and the right side cover 53 have a structure that can be opened and closed, and the left side cover 52 and the right side cover 53 can access the heat exchange device 26 and the hydraulic pump 24, respectively. Is provided with a suction port 52a for taking in outside air in the machine room 20.

The upper cover 55 extends in the left-right direction between the upper end portion of the left side cover 52 and the upper end portion of the right side cover 53, and enables access to the engine 22, the exhaust gas aftertreatment device 23, and the like. It is composed of a top plate cover 56 having an opening 56a, and an engine cover 57 that bulges above the top plate cover 56 and surrounds the access opening 56a of the top plate cover 56 so as to be openable and closable. The top plate cover 56 is located higher than the engine 22, but is located at a height at which a part of the exhaust gas aftertreatment device 23 protrudes.

As shown in FIGS. 2, 3, and 5, the engine cover 57 is formed in a box shape that opens downward, and the exhaust gas aftertreatment device 23 is in a state where the access opening 56a of the top plate cover 56 is closed. It is configured to be able to accommodate a part (a part of the NOx purification device 42). The engine cover 57 surrounds, for example, the front peripheral surface portion 61 that surrounds the access opening 56a of the top plate cover 56 from the front side, the rear peripheral surface portion 62 that surrounds the access opening 56a from the rear side, and the access opening 56a from the left side. It is composed of a left peripheral surface portion 63, a right peripheral surface portion 64 that surrounds the access opening 56a from the right side, and an upper surface portion 65 that covers each peripheral surface portion 61, 62, 63, 64 from the upper side. As shown in FIG. 3, the right peripheral surface portion 64 is a cover portion that is located close to the NOx purifying device 42 and covers the side of the NOx purifying device 42. The portion of the upper surface portion 65 on the right peripheral surface portion 64 side is a cover portion that is located close to the NOx purifying device 42 and covers the upper part of the NOx purifying device 42.

As shown in FIGS. 3 and 5, a plurality of lateral openings 64a (4 in FIG. 5) that open laterally are provided on the right peripheral surface portion 64 in the front-rear direction. The side opening 64a is configured so that the cooling air generated by the cooling fan 25 can be discharged to the outside of the machine room 20. A plurality of upper opening portions 65a (two in FIG. 3) that open in the vertical direction are provided in the portion of the upper surface portion 65 close to the NOx purifying device 42. The upper opening 65a is configured so that the cooling air generated by the cooling fan 25 can be discharged to the outside of the machine room 20. As shown in FIGS. 2, 3, and 5, a turning member 58 is attached to each of the upper openings 65a. The turning member 58 turns the direction of the cooling air discharged from the upper opening 65a to the outside of the machine room 20 from the upper side to the right side. A tail tube 59 is provided on the upper surface portion 65. The tail pipe 59 is configured to be connected to the outflow pipe 29 of the exhaust gas aftertreatment device 23 with the engine cover 57 closed.

Further, as shown in FIGS. 3 and 4, a partition wall 70 for partitioning the engine 22 and the exhaust gas aftertreatment device 23 and the hydraulic pump 24 is provided in the machine room 20. The partition wall 70 prevents the hydraulic oil from adhering to the high temperature portion of the engine 22 and the exhaust gas aftertreatment device 23 and igniting when the hydraulic oil leaks from the hydraulic pump 24. The partition wall 70 is formed according to the arrangement and shape of the engine 22 and the exhaust gas aftertreatment device 23. For example, the partition wall 70 rises from the upper side of the right tail frame 15b and bends to the right from the lower vertical plate portion 71 that separates the engine 22 side and the hydraulic pump 24 side in the left-right direction and the upper end portion of the lower vertical plate portion 71. , The PM collecting device 41 side rising from the first horizontal plate portion 72 that vertically separates the PM collecting device 41 side and the hydraulic pump 24 side of the exhaust gas aftertreatment device 23 and the right end portion of the first horizontal plate portion 72. The central vertical plate portion 73 that separates the surface from the hydraulic pump 24 side in the left-right direction, and the NOx purification device 42 side and the hydraulic pump 24 side of the exhaust gas aftertreatment device 23 that bend to the right from the upper end portion of the central vertical plate portion 73. It is composed of a second horizontal plate portion 74 that divides the surface in the vertical direction and an upper vertical plate portion 75 that rises from the right end portion of the second horizontal plate portion 74 and separates the NOx purification device 42 side and the hydraulic pump 24 side in the left-right direction. ing. The lower vertical plate portion 71 is provided with a through hole portion 71a for penetrating the hydraulic pump 24. The partition wall 70 extends from the lower part to the upper part of the machine room 20.

In the machine room 20, as shown in FIG. 3, a space (gap) formed between the PM collecting device 41 and the NOx purifying device 42 of the exhaust gas aftertreatment device 23 and the partition wall 70 and the NOx purifying device 42 are provided. The space (gap) formed between the engine cover 57 and the right peripheral surface portion 64 constitutes a ventilation passage P having the side opening 64a of the right peripheral surface portion 64 as an exhaust port. The upstream end of the ventilation passage P is a region connecting the lower end of the PM collecting device 41 of the exhaust gas aftertreatment device 23 and the portion of the partition wall 70 at the height of the lower end of the PM collecting device 41. The downstream end of the ventilation passage P is a region connecting the upper end of the NOx purifying device 42 of the exhaust gas aftertreatment device 23 and the height position of the upper end of the NOx purifying device 42 in the lateral opening 64a of the right peripheral surface portion 64.

As shown in FIGS. 3 and 4, the ventilation passage P is provided with a barrier portion 80 that obstructs the flow of air to the side opening 64a of the ventilation passage P. Specifically, the barrier portion 80 is, for example, a plate that protrudes horizontally from the upper end portion of the upper vertical plate portion 75 of the partition wall 70 toward the ventilation passage P and extends in the extending direction (front-back direction) of the NOx purifying device 42. It is a member. The barrier portion 80 does not completely block the ventilation passage P, but has a gap between the barrier portion 80 and the NOx purifying device 42.

Next, the operation and effect of one embodiment of the construction machine of the present invention will be described with reference to FIGS. 2, 3, 5, and 6 while comparing with the conventional construction machine. FIG. 6 is a cross-sectional view showing the internal structure of the machine room of a conventional hydraulic excavator as a comparative example with respect to an embodiment of the construction machine of the present invention. In FIGS. 3 and 6, the thick arrow indicates the natural convection when the cooling fan is stopped. The left-right direction in FIG. 6 is the left-right direction of the hydraulic excavator. In the comparative example shown in FIG. 6, those having the same reference numerals as those shown in FIGS. 1 to 5 are the same parts as those of the present embodiment, and detailed description thereof will be omitted.

The difference between the internal structure of the machine room 200 of the conventional hydraulic excavator shown in FIG. 6 and the internal structure of the machine room 20 of the hydraulic excavator 1 of the present embodiment is that the barrier portion 80 does not exist. Other configurations of the internal structure of the conventional machine room 200 are the same as the configuration of the internal structure of the machine room 20 of the present embodiment.

In the present embodiment and the conventional hydraulic excavator, when the engine 22 shown in FIGS. 3 and 6 is driven, high-temperature exhaust gas flows inside the exhaust gas aftertreatment device 23, and the engine 22 and the exhaust gas aftertreatment device 23 Heat is released from the surface to the surrounding environment. At this time, since the cooling fan 25 is rotationally driven by the drive of the engine 22, outside air is sucked into the machine rooms 20 and 200 from the suction port 52a of the left side cover 52, and cooling air is generated in the machine rooms 20 and 200. Will be done. The cooling air in the machine rooms 20 and 200 first passes through the heat exchange device 26 and cools the high-temperature engine cooling water and hydraulic oil flowing in the heat exchange device 26. After that, it passes through the shroud 34 on the right side of the heat exchange device 26, is introduced into the cooling fan 25, and is discharged to the engine 22 side.

Of the cooling air discharged from the cooling fan 25, the cooling air discharged upward in the machine rooms 20 and 200 passes around the upper part of the engine 22 and heats heat from the surface of the engine 22 and the exhaust gas aftertreatment device 23. After receiving the engine cover 57, the engine cover 57 flows out of the machine room 20 and 200 from the side opening 64a and the upper opening 65a. On the other hand, the cooling air discharged to the lower side in the machine rooms 20 and 200 passes around the lower part of the engine 22 and receives heat from the surface of the engine 22, and then a part of the cooling air is the lower first side of the lower cover 51. It flows out from the opening 51a to the outside of the machine rooms 20 and 200. Further, a part thereof passes through the through hole portion 91a of the partition wall 90, flows into the peripheral portion of the hydraulic pump 24, and flows out from the lower second opening 51b of the lower cover 51 to the outside of the machine chambers 20 and 200.

As described above, in the present embodiment and the conventional hydraulic excavator, when the cooling fan 25 is driven, the side opening 64a of the engine cover 57, the upper side, from the suction port 52a of the left side cover 52 in the machine room 20 and 200. Since forced convection occurs toward the lower first opening 51a and the lower second opening 51b of the opening 65a and the lower cover 51, the heat released to the surroundings from the engine 22, the exhaust gas aftertreatment device 23, etc. is mechanically generated. It can be efficiently discharged to the outside of the chambers 20 and 200.

In the internal structure of the machine room 20 in the present embodiment, unlike the internal structure of the conventional machine room 200, the barrier portion 80 is arranged in the ventilation passage P, so that the barrier portion 80 is in the ventilation passage P. May affect the flow of. However, since the heat in the machine chamber 20 is efficiently discharged to the outside by the forced convection generated by the cooling fan 25, even if the barrier portion 80 affects the flow, the exhaust gas temperature sensor 44 of the PM collecting device 41 and the exhaust gas temperature sensor 44 The temperature of the reducing agent supply device 46 and the NOx sensor 47 of the NOx purifying device 42 does not rise excessively.

After that, when the engine 22 being driven is stopped due to the end of work or the like, the cooling fan 25 is stopped at the same time, so that the cooling air from the cooling fan 25 is not supplied to the machine rooms 20 and 200. In this case, the temperature of the air around the engine 22 and the exhaust gas aftertreatment device 23 rises due to the heat remaining in the engine 22 and the exhaust gas aftertreatment device 23. The air whose temperature has risen has an upward buoyancy in the vertical direction due to the difference in density from the outside air. As a result, in the machine rooms 20 and 200, the lower first opening 51a and the lower second opening 51b of the lower cover 51 are directed upward toward the upper opening 65a and the side opening 64a of the engine cover 57. Natural convection occurs.

In the internal structure of the conventional machine room 200, as shown in FIG. 6, a part of the upward natural convection is a ventilation path P (a space formed between the exhaust gas aftertreatment device 23 and the partition wall 70, and exhaust gas. The space formed between the aftertreatment device 23 and the right peripheral surface portion 64 of the engine cover 57) flows through the side opening 64a of the right peripheral surface portion 64 of the engine cover 57 and the upper opening 65a of the upper surface portion 65. It flows out to the outside of the machine room 200. Further, a part of the upward natural convection flows through the space on the left side of the exhaust gas aftertreatment device 23 (the space near the exhaust gas aftertreatment device 23 existing on the opposite side of the ventilation passage P across the exhaust gas aftertreatment device 23). It flows out to the outside of the machine room 200 through the upper opening 65a. As a result, the heat remaining in the exhaust gas aftertreatment device 23 is discharged to the outside of the machine room 200.

The natural convection F1 from the ventilation path P toward the side opening 64a of the right peripheral surface portion 64 and the upper opening 65a of the upper surface portion 65 is a flow having a particularly large velocity component in the vertical direction upward direction. Further, the natural convection F2 from the space on the left side of the exhaust gas aftertreatment device 23 toward the upper opening 65a also has a particularly large velocity component in the vertical direction upward direction.

The side opening 64a is an opening that opens laterally (left-right direction), and the opening direction of the side opening 64a is close to a direction orthogonal to the flow direction of the natural convection F1 toward the side opening 64a. It is oriented. Therefore, it is difficult to efficiently allow the natural convection F1 flowing through the ventilation path P to flow out from the side opening 64a to the outside of the machine room 200. That is, it is difficult to allow a sufficient flow rate of natural convection F1 to flow out of the machine room 200 from the side opening 64a and efficiently discharge the heat in the machine room 200 to the outside.

On the other hand, the upper opening 65a is an opening that opens in the vertical direction, and the opening direction of the upper opening 65a is oriented so as to substantially coincide with the flow directions of the natural convections F1 and F2 toward the upper opening 65a. ing. Therefore, the upper opening 65a has a configuration capable of efficiently discharging the upward natural convection F1 and F2 to the outside of the machine room 200.

However, as shown in FIGS. 2 and 5, the opening area of the upper opening 65a is limited by the installation space of the tail tube 59, so that it may not be possible to secure a sufficiently large opening area. In natural convection driven by a density difference, unlike forced convection driven by a cooling fan 25, a sufficient flow rate can flow out from the upper opening 65a, which does not have a sufficient opening area. This is not possible, and there is a risk that the flow will stay in the vicinity of the upper opening 65a in the machine room 200. In this case, since the natural convection F1 in the ventilation passage P flows toward the side opening 64a of the right peripheral surface portion 64, the flow staying in the vicinity of the upper opening 65a in the machine room 200 is in the vicinity of the upper opening 65a. It is difficult to turn toward the side opening 64a of the right peripheral surface portion 64 located at. Therefore, if the upper opening 65a does not have a sufficient opening area, it becomes difficult to efficiently discharge the heat in the machine room 200 to the outside.

As described above, in the internal structure of the conventional machine room 200, when the cooling fan is stopped due to the stop of the engine 22, the heat in the machine room 200 is efficiently transferred to the outside from the upper opening 65a and the side opening 64a. There is a risk that it cannot be discharged. In this case, the temperatures of the exhaust gas temperature sensor 44 of the PM collecting device 41, the reducing agent supply device 46 of the NOx purifying device 42, and the NOx sensor 47 may rise excessively, and these may fail.

On the other hand, in the present embodiment, as shown in FIG. 3, the barrier portion 80 is arranged in the ventilation passage P. When the cooling fan 25 is stopped due to the stop of the engine 22, natural convection to the side opening 64a and the upper opening 65a in the ventilation path P is hindered by the barrier portion 80. As a result, most of the natural convection in the ventilation path P joins the natural convection F2 flowing in the space on the left side of the exhaust gas aftertreatment device 23 through the gap between the PM collection device 41 and the NOx purification device 42. do.

The natural convection F2 flowing through the space on the left side of the exhaust gas aftertreatment device 23 flows out to the outside of the machine room 20 through the upper opening 65a of the upper surface portion 65. When the opening area of the upper opening 65a is sufficiently secured, the upper opening 65a that opens in the vertical direction moves upward to the outside of the machine room 20 without retaining the natural convection in the machine room 20. It can be leaked. On the other hand, when the opening area of the upper opening 65a is not sufficiently secured, the natural convection of a sufficient flow rate cannot be discharged to the outside of the machine room 20 through the upper opening 65a, and the natural convection F2. A part of it stays in the vicinity of the upper opening 65a in the machine room 20. In this case, since the barrier portion 80 obstructs the flow to the side opening 64a and the upper opening 65a in the ventilation passage P (see FIG. 6), the flow accumulated in the vicinity of the upper opening 65a is the upper surface portion 65. It becomes easy to flow in a substantially horizontal direction toward the side opening 64a along the line. The flow F3 toward the side opening 64a is oriented so as to substantially coincide with the opening direction of the side opening 64a. Therefore, since the flow F3 toward the side opening 64a efficiently flows out to the outside of the machine room 20 through the side opening 64a, it flows out from the ventilation path P to the outside of the machine room 20 through the side opening 64a. The heat in the machine room 20 can be efficiently discharged to the outside as compared with the case where the heat flows out to the outside.

Further, in the present embodiment, the barrier portion 80 is arranged in the ventilation passage P formed between the NOx purification device 42 located closer to the lateral opening 64a than the PM collecting device 41 and the partition wall 70. Therefore, the barrier portion is directed from the ventilation passage P toward the side opening 64a or the upper opening 65a rather than the case where the barrier portion is arranged in the ventilation passage P formed between the PM collecting device 41 and the partition wall 70. It can block the flow of natural convection.

Further, in the present embodiment, since the barrier portion 80 is provided at the upper end portion of the upper vertical plate portion 75 of the partition wall 70, the partition wall 70 and the barrier portion 80 can be integrally formed.

As described above, according to one embodiment of the construction machine of the present invention, by arranging the barrier portion 80 in the ventilation passage P, the side opening 64a of the ventilation passage P when the cooling fan 25 is stopped (the first). Since the flow of air to the 2 openings) is obstructed, a part of the flow near the upper opening 65a (first opening) in the machine room 20 when the cooling fan 25 is stopped is divided into the side openings 64a (2 openings). It can be discharged from the second opening) to the outside of the machine room 20 so as to substantially coincide with the opening direction of the side opening 64a (second opening). Therefore, the heat in the machine chamber 20 can be efficiently discharged to the outside from the upper opening 65a (first opening) and the side opening 64a (second opening), and the exhaust gas of the exhaust gas aftertreatment device 23 can be discharged to the outside. It is possible to prevent an excessive temperature rise of the temperature sensor 44, the reducing agent supply device 46, and the NOx sensor 47 (equipment).

Next, the first to seventh modifications of the embodiment of the construction machine of the present invention will be described with reference to FIGS. 7 to 13. FIG. 7 is a cross-sectional view showing the inside of the machine chamber in the first modification of the first embodiment of the construction machine of the present invention, and FIG. 8 is the machine chamber in the second modification of the embodiment of the construction machine of the present invention. FIG. 9 is a sectional view showing the inside, FIG. 9 is a sectional view showing the inside of the machine chamber in the third modification of the third modification of the embodiment of the construction machine of the present invention, and FIG. 10 is the fourth embodiment of the construction machine of the present invention. A sectional view showing the inside of the machine chamber in the modified example, FIG. 11 is a sectional view showing the inside of the machine chamber in the fifth modified example of the fifth embodiment of the construction machine of the present invention, and FIG. 12 is one of the construction machines of the present invention. FIG. 13 is a cross-sectional view showing the inside of the machine chamber in the sixth modification of the embodiment, and FIG. 13 is a cross-sectional view showing the inside of the machine chamber in the seventh modification of the sixth modification of the construction machine of the present invention. In FIGS. 7 to 13, the thick arrow indicates the natural convection when the cooling fan is stopped. Further, the left-right direction in FIGS. 7 to 13 is the left-right direction of the hydraulic excavator. In FIGS. 7 to 13, those having the same reference numerals as those shown in FIGS. 1 to 6 have the same reference numerals, and therefore detailed description thereof will be omitted.

The first to seventh modifications of the embodiment of the construction machine of the present invention shown in FIGS. 7 to 13 are different from the embodiment of the construction machine of the present invention (see FIG. 3) in that ventilation. The installation position of the barrier portion that obstructs the flow in the road P is different.

Specifically, the barrier portion 80A in the first modification shown in FIG. 7 projects horizontally from the position of the lower end portion of the side opening 64a in the right peripheral surface portion 64 of the engine cover 57 to the ventilation path P to purify NOx. It is a plate member extending in the extending direction (front-back direction) of the device 42. The barrier portion 80A can be configured as, for example, one plate member extending over a plurality of side openings 64a (see FIG. 5). Further, it is also possible to provide each of the plurality of side openings 64a individually. The barrier portion 80A does not completely block the ventilation passage P, and has a gap between the barrier portion 80A and the NOx purifying device 42.

In this modification, when the cooling fan 25 is stopped, the barrier portion 80A obstructs the flow to the side opening 64a in the ventilation passage P, while a part of the flow in the vicinity of the upper opening 65a in the machine room 20. Is guided to the side opening 64a as a horizontal flow F3. Since the barrier portion 80A guides the horizontal flow F3 to the side opening 64a, the heat in the machine room 20 can be discharged to the outside more effectively than in one embodiment.

The barrier portion 80B in the second modification shown in FIG. 8 is directed from a position substantially the same height as the lower end portion of the side opening 64a of the engine cover 57 in the NOx purifying device 42 toward the lower end of the side opening 64a. It is a plate member that protrudes horizontally to the ventilation path P and extends in the extending direction (front-back direction) of the NOx purifying device 42. The barrier portion 80B does not completely block the ventilation passage P, and has a gap between the barrier portion 80B and the right peripheral surface portion 64 of the engine cover 57.

In this modification, as in the first modification, the barrier portion 80B blocks the flow to the side opening 64a in the ventilation passage P when the cooling fan 25 is stopped, and the upper opening in the machine room 20. A part of the flow in the vicinity of the portion 65a is guided to the side opening 64a as a horizontal flow F3. Since the barrier portion 80B guides the horizontal flow F3 to the side opening 64a, the heat in the machine room 20 can be discharged to the outside more effectively than in one embodiment.

The barrier portion 80C in the third modification shown in FIG. 9 is directed from the outer peripheral surface of the engine cover 57 on the side opening 64a side of the tubular housing of the NOx purifying device 42 toward the upper end side of the side opening 64a. It is a plate member that protrudes into the ventilation passage P and extends in the extending direction (front-back direction) of the NOx purifying device 42.

In this modification, when the cooling fan 25 is stopped, the barrier portion 80C obstructs the flow to the side opening 64a in the ventilation passage P, and a part of the natural convection in the ventilation passage P is collected by the PM collecting device. It leads to the space on the left side of the exhaust gas aftertreatment device 23 through the gap between 41 and the NOx purification device 42. Further, the barrier portion 80C is a machine while turning a part of the flow to the side opening 64a in the ventilation passage P from substantially upward in the vertical direction toward the opening direction (horizontal direction) of the side opening 64a. A part of the flow in the vicinity of the upper opening 65a in the chamber 20 is drawn into the side opening 64a as a horizontal flow F3. Since a part of the natural convection to the side opening 64a in the ventilation path P approaches the opening direction (horizontal direction) of the side opening 64a, the heat in the machine room 20 can be efficiently discharged to the outside. can.

The barrier portion 80D in the fourth modification shown in FIG. 10 is erected vertically on the outer peripheral surface near the upper vertical plate portion 75 of the partition wall 70 in the tubular accommodating body of the NOx purification device 42, protrudes into the ventilation passage P, and protrudes into the NOx. It is a plate member extending in the extending direction (front-back direction) of the purification device 42. The barrier portion 80D does not completely block the ventilation passage P, and has a gap between the barrier portion 80D and the upper vertical plate portion 75 of the partition wall 70.

In this modification, when the cooling fan 25 is stopped, the barrier portion 80D obstructs the flow to the side opening 64a in the ventilation passage P, and collects most of the natural convection in the ventilation passage P by PM. It leads to the space on the left side of the exhaust gas aftertreatment device 23 through the gap between the device 41 and the NOx purification device 42. As a result, most of the natural convection in the ventilation passage P joins the natural convection F2, and the heat in the machine room 20 is efficiently discharged to the outside through the upper opening 65a and the side opening 64a. Can be done.

The barrier portion 80E in the fifth modification shown in FIG. 11 projects from the end portion of the second horizontal plate portion 74 of the partition wall 70 on the center side vertical plate portion 73 side toward the NOx purifying device 42 into the ventilation passage P, and is the second. It is a plate member extending in the width direction (front-back direction) of the horizontal plate portion 74. The barrier portion 80E does not completely block the ventilation passage P, and has a gap between the barrier portion 80E and the NOx purifying device 42.

In this modification, as in the fourth modification, the barrier portion 80E obstructs the flow to the side opening 64a in the ventilation passage P when the cooling fan 25 is stopped, and natural convection in the ventilation passage P. Most of the parts are guided to the space on the left side of the exhaust gas aftertreatment device 23 through the gap between the PM collecting device 41 and the NOx purifying device 42. As a result, most of the natural convection in the ventilation passage P joins the natural convection F2, and the heat in the machine room 20 is efficiently discharged to the outside through the upper opening 65a and the side opening 64a. Can be done.

The barrier portion 80F in the sixth modification shown in FIG. 12 projects from the central vertical plate portion 73 of the partition wall 70 toward the PM collecting device 41 toward the ventilation passage P, and is in the width direction (front-back direction) of the central vertical plate portion 73. ) Is a plate member extending. The barrier portion 80F does not completely block the ventilation passage P, and has a gap between the barrier portion 80F and the PM collecting device 41.

In this modification, when the cooling fan 25 is stopped, the barrier portion 80F obstructs a part of the flow to the side opening 64a in the ventilation passage P. Therefore, the heat in the machine room 20 can be efficiently discharged to the outside as compared with the case where there is no barrier portion in the ventilation passage P as in the case of the internal structure of the conventional machine room 200.

The barrier portion 80G in the seventh modification shown in FIG. 13 projects from the outer peripheral surface of the tubular accommodating body of the PM collecting device 41 toward the central vertical plate portion 73 of the partition wall 70 toward the ventilation passage P, and is a PM collecting device. It is a plate member extending in the extending direction (front-back direction) of 41. The barrier portion 80G does not completely block the ventilation passage P, and has a gap between the barrier portion 80G and the central vertical plate portion 73.

In this modification, similarly to the sixth modification, the barrier portion 80G obstructs a part of the flow to the side opening 64a in the ventilation passage P when the cooling fan 25 is stopped. Therefore, the heat in the machine room 20 can be efficiently discharged to the outside as compared with the case where there is no barrier portion in the ventilation passage P as in the case of the internal structure of the conventional machine room 200.

According to the first to seventh modifications of the above-described embodiment of the construction machine of the present invention, the barrier portions 80A, 80B, 80C, 80D, 80E, in the ventilation passage P, as in the above-mentioned one embodiment. By arranging 80F and 80G, the air flow to the side opening 64a (second opening) of the ventilation path P when the cooling fan 25 is stopped is obstructed, so that the machine when the cooling fan 25 is stopped A part of the flow near the upper opening 65a (first opening) in the chamber 20 substantially coincides with the opening direction from the side opening 64a (second opening) to the side opening 64a (second opening). It can be discharged to the outside of the machine room 20 as if it were. Therefore, the heat in the machine chamber 20 can be efficiently discharged to the outside from the upper opening 65a (first opening) and the side opening 64a (second opening), so that the exhaust gas aftertreatment device 23 can be used. It is possible to prevent an excessive temperature rise of the exhaust gas temperature sensor 44, the reducing agent supply device 46, and the NOx sensor 47 (equipment).

Further, according to the first to fifth modifications, a barrier is formed in the ventilation passage P formed between the NOx purifying device 42 and the partition wall 70 located closer to the side opening 64a than the PM collecting device 41. Since the portions 80A, 80B, 80C, 80D, and 80E are arranged, the natural convection in the ventilation path P is obstructed while obstructing the flow of the natural convection from the ventilation path P to the side opening 64a and the upper opening 65a. A part of the space can be guided to the space on the left side of the NOx purification device 42 (opposite the ventilation path P across the NOx purification device 42) through the gap between the PM collection device 41 and the NOx purification device 42.

In the above-described embodiment of the construction machine of the present invention and the first to seventh modifications thereof, an example in which the construction machine of the present invention is applied to the hydraulic excavator 1 is shown, but the present invention describes the engine 22. It can be widely applied to various construction machines such as hydraulic cranes and wheel loaders provided with an exhaust gas aftertreatment device 23 for purifying the exhaust gas and a cooling fan 25 for cooling the engine 22 and the exhaust gas aftertreatment device 23.

Further, the present invention is not limited to the present embodiment, and includes various modifications. The above-described embodiments have been described in detail in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the described configurations. It is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. It is also possible to add, delete, or replace a part of the configuration of each embodiment with another configuration.

For example, in the above-described embodiment and the first to seventh modifications thereof, there is an example of a configuration in which two aftertreatment devices, a PM collection device 41 and a NOx purification device 42, are provided as the exhaust gas aftertreatment device 23. As shown, configurations with at least one aftertreatment device are also possible.

Further, in the above-described embodiment and the first to seventh modifications thereof, there is an example of a configuration in which one barrier portion 80, 80A, 80B, 80C, 80D, 80E, 80F, 80G is arranged in the ventilation passage P. As shown, it is also possible to arrange a plurality of barrier portions at different positions in the ventilation path P. For example, as shown in FIG. 14, the barrier portion 80A in the first modification and the barrier portion 80F in the sixth modification can be combined. FIG. 14 is a cross-sectional view showing an example of installation positions of a plurality of barrier portions in the internal structure of the machine room of another embodiment of the construction machine of the present invention. The left-right direction in FIG. 14 is the left-right direction of the hydraulic excavator.

Further, in the above-described embodiment and the first to seventh modifications thereof, examples of the barrier portions 80, 80A, 80B, 80C, 80D, 80E, 80F, 80G having a configuration that does not completely block the ventilation passage P. However, it is also possible to configure the barrier portions 80, 80A, 80B, 80C, 80D, 80E, 80F, and 80G to completely block the ventilation passage P.

1 ... Hydraulic excavator (construction machine), 20 ... Machine room, 22 ... Engine, 23 ... Exhaust gas aftertreatment device, 24 ... Hydraulic pump, 25 ... Cooling fan, 41 ... PM collection device (1st aftertreatment device), 42 ... NOx purification device (second post-treatment device), 50 ... Machine room cover, 64 ... Right peripheral surface (second cover part), 64a ... Side opening (second opening), 65 ... Top surface (first) Cover part), 65a ... Upper opening (first opening), 70 ... Bulk partition, 80, 80A, 80B, 80C, 80D, 80E, 80F, 80G ... Barrier part, P ... Ventilation passage.

Claims (7)

The machine room whose outer shell is formed by the machine room cover,
The engine housed in the machine room and
An exhaust gas aftertreatment device that is located above the machine room and purifies the exhaust gas of the engine.
A hydraulic pump located below the exhaust gas aftertreatment device in the machine room and driven by the engine, and
A cooling fan housed in the machine room and generating cooling air,
In a construction machine provided with a partition wall separating the exhaust gas aftertreatment device and the hydraulic pump in the machine room.
The machine room cover is
A first cover portion that covers the upper part of the exhaust gas aftertreatment device and has a first opening capable of discharging the cooling air generated by the cooling fan.
A second cover portion that covers the side of the exhaust gas aftertreatment device and has a second opening capable of discharging the cooling air generated by the cooling fan.
A ventilation path provided between the exhaust gas aftertreatment device and the partition wall and between the exhaust gas aftertreatment device and the second cover portion.
A construction machine arranged in the ventilation passage and further provided with a barrier portion that obstructs the flow of air to the second opening of the ventilation passage. In the construction machine according to claim 1,
The construction machine is characterized in that the barrier portion is a portion of the second cover portion of the machine room cover that protrudes from the lower end portion of the second opening to the ventilation path. In the construction machine according to claim 1,
A construction machine characterized in that the barrier portion is a portion protruding from the partition wall to the ventilation passage. In the construction machine according to claim 1,
A construction machine characterized in that the barrier portion is a portion protruding from the exhaust gas aftertreatment device to the ventilation passage. In the construction machine according to claim 4,
The barrier portion is a portion of the exhaust gas aftertreatment device that projects from the height of the lower end portion of the second opening toward the lower end of the second opening toward the ventilation passage. Construction machinery. In the construction machine according to claim 1,
The exhaust gas aftertreatment device is
The first aftertreatment device and
It is provided with a second post-treatment device which is arranged with a gap with respect to the first post-treatment device and is located closer to the second opening than the first post-treatment device.
The construction machine characterized in that the barrier portion is arranged in the ventilation passage formed by the second aftertreatment device among the ventilation passages. In the construction machine according to claim 1,
The barrier portion is a construction machine characterized in that it is arranged at a plurality of positions of the ventilation passage.

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