Construction machinery

Abstract

The present invention provides a construction machine that can reduce the frequency of cleaning up leaked or scattered urea solution when replenishing urea solution in a urea solution tank. [Solution] The construction machine 1 includes a urea aqueous solution tank 40 in which urea aqueous solution is stored and located in a machine room 44 provided on the vehicle body, a receiving container 50 attached to the supply port 48 of the urea aqueous solution tank 40, a maintenance opening 14b formed in the machine room 44 that allows access to the urea aqueous solution tank 40, and a maintenance cover 14c that opens and closes between an open position that opens the maintenance opening 14b and a closed position. The receiving container 50 is provided so as to surround the supply port 48 and has a receiving tray 52 that receives urea aqueous solution that leaks around the supply port 48, and a cylindrical pocket 54 connected to the receiving tray 52 that collects and discharges the urea aqueous solution that flows down the receiving tray 52. ​​The pocket 54 is in contact with the maintenance cover when the maintenance cover is in the closed position.

Description

Technical Field

[0001] The present invention relates to construction machinery, and particularly to construction machinery equipped with an aqueous urea tank for storing an aqueous urea solution supplied to an exhaust gas purification device.

Background Art

[0002] Patent Document 1 discloses construction machinery equipped with an exhaust gas purification device for purifying the exhaust gas of an engine. This construction machinery is equipped with a liquid reducing agent tank (aqueous urea solution tank) for storing a liquid reducing agent (aqueous urea solution) supplied to the exhaust gas purification device. This aqueous urea solution tank is installed in a tool box disposed on the upper revolving body of the construction machinery.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The aqueous urea solution tank has a supply port to which the nozzle of a storage container storing the aqueous urea solution is inserted to supply the aqueous urea solution to the aqueous urea solution tank. During such a liquid supply operation, the aqueous urea solution may drip around from the tip of the nozzle, or may splash out from the supply port, causing droplets of the aqueous urea solution to leak and scatter around. Since the aqueous urea solution corrodes some metals and resins, it is necessary to regularly clean the aqueous urea solution that has leaked and scattered at the supply port.

[0005] The present invention has been made in view of such problems, and its object is to provide construction machinery capable of reducing the frequency of cleaning work for the leaked and scattered aqueous urea solution when replenishing the aqueous urea solution to the aqueous urea solution tank.

Means for Solving the Problems

[0006] To achieve the above objectives, the construction machine of the present invention comprises a vehicle body, a urea aqueous solution tank for storing urea aqueous solution and located in a machine room provided in the vehicle body, a receiving container attached to the supply port of the urea aqueous solution tank, a maintenance opening formed in the machine room that allows access to the urea aqueous solution tank, and a maintenance cover that opens and closes between an open position that opens the maintenance opening and a closed position that closes the maintenance opening. The receiving container is provided surrounding the supply port and has a receiving tray for receiving urea aqueous solution that leaks around the supply port, and a cylindrical pocket connected to the receiving tray for collecting and discharging the urea aqueous solution that flows down the receiving tray. The pocket is characterized in that it is in contact with the maintenance cover when the maintenance cover is in the closed position. [Effects of the Invention]

[0007] According to the construction machinery of the present invention, the frequency of cleaning work for leaked or scattered urea solution when replenishing urea solution in a urea solution tank can be reduced. [Brief explanation of the drawing]

[0008] [Figure 1] This is a side view of a hydraulic excavator, which is an example of a construction machine according to an embodiment of the present invention. [Figure 2] This is a top view of a hydraulic excavator, with some of the working equipment and the top cover of the upper rotating body omitted. [Figure 3] This is a perspective view of a hydraulic excavator with some of its working equipment omitted, seen from the left rear. [Figure 4] This is a perspective view of a urea solution tank. [Figure 5] This is a front view of the receiving container. [Figure 6] This is a top view of the receiving container. [Figure 7] This is a side view of the receiving container. [Figure 8] This is a schematic cross-sectional view of a urea solution tank seen from the side during liquid supply operations. [Figure 9] This is a schematic cross-sectional view of the receiving container from the side when the maintenance cover is moved from the open position to the closed position. [Figure 10] This is a schematic side view of a receiving container of a different form attached to a urea aqueous solution tank, as seen from the side. [Modes for carrying out the invention]

[0009] Hereinafter, a construction machine according to an embodiment of the present invention will be described with reference to the drawings. Figure 1 shows a side view of a hydraulic excavator 1, which is an example of a construction machine. Hereafter, the "front-rear direction" and "up-down direction" as shown in the figures refer to directions relative to the body of the hydraulic excavator 1, and the "left-right direction" refers to directions relative to an operator who is seated on the hydraulic excavator 1 and facing forward. The hydraulic excavator 1 comprises a self-propelled crawler-type lower vehicle 2, an upper slewing body 6 that is rotatably mounted on the lower vehicle 2 via a slewing device 4, and a work device 8 that is provided on the front side of the upper slewing body 6 so as to be able to be tilted up and down and is used for excavation work, etc. The upper part of the upper slewing body 6 is covered with an upper cover 6a and is equipped with a slewing frame 10 that constitutes the support structure of the upper slewing body 6. A cab 12 in which the operator sits is located on the left front side of the slewing frame 10, and a counterweight 14 for balancing the weight with the work device 8 is located on the rear side of the slewing frame 10.

[0010] Figure 2 shows a top view of the hydraulic excavator 1 with part of the work device 8 and the top cover 6a of the upper slewing body 6 omitted. In the upper slewing body 6, the engine 16 is mounted in front of the counterweight 14 and behind the slewing frame 10. A cooling fan 18 is provided to the left of the engine 16. The cooling fan 18 rotates using the engine 16 as a power source and draws in outside air as cooling air. A heat exchanger 20 is located to the left of the cooling fan 18. Cooling air drawn in by the cooling fan 18 flows through the heat exchanger 20. The heat exchanger 20 consists of a radiator 22, an oil cooler 24, an intercooler 26, an air conditioning condenser 28, etc., and the fluid flowing through these is cooled by the cooling air from the cooling fan 18.

[0011] An under cover 10a is provided on the left rear of the slewing frame 10. The under cover 10a is a substantially flat plate, and a heat exchanger 20 and the like are attached to it. A hydraulic pump 30 is mounted on the right side of the engine 16. A hydraulic oil tank 32 is provided on the slewing frame 10 in front of the hydraulic pump 30. When the hydraulic pump 30 is driven by the engine 16, hydraulic oil as pressurized oil is discharged from the hydraulic oil tank 32 to a control valve device (not shown).

[0012] The control valve device supplies hydraulic fluid to the actuators provided in the lower traveling body 2, the slewing device 4 of the upper rotating body 6, and the working device 8, and drives the lower traveling body 2, the slewing device 4, and the working device 8 by the pressure of the hydraulic fluid. A fuel tank 34 is provided on the slewing frame 10 to the right of the hydraulic fluid tank 32. The fuel tank 34 supplies fuel to the engine 16. Furthermore, an exhaust gas purification device 36 is provided to the right of the engine 16 and above the hydraulic pump 30. The exhaust gas purification device 36 is connected to the exhaust pipe 16a through which exhaust gas from the engine 16 flows, and oxidizes and removes carbon monoxide (CO), hydrocarbons (HC), etc. contained in the exhaust gas discharged from the engine 16, purifies nitrogen oxides (NOx) contained in the exhaust gas, and also reduces exhaust noise.

[0013] More specifically, the exhaust gas purification device 36 includes a first exhaust gas aftertreatment device 36a connected to the exhaust pipe 16a of the engine 16 on its inlet side, a connecting pipe 36b connected to the outlet side of the first exhaust gas aftertreatment device 36a, a urea aqueous solution injection valve 36c provided in the connecting pipe 36b for injecting urea aqueous solution, and a second exhaust gas aftertreatment device 36d connected to the outlet side of the connecting pipe 36b. An oxidation catalyst (not shown) is housed inside the first exhaust gas aftertreatment device 36a. This oxidation catalyst constitutes one of the treatment components for purifying the exhaust gas. The oxidation catalyst oxidizes and removes carbon monoxide (CO), hydrocarbons (HC), etc. contained in the exhaust gas by passing the exhaust gas through it at a predetermined temperature.

[0014] The urea aqueous solution injection valve 36c injects the urea aqueous solution into the exhaust gas flowing through the connecting pipe 36b. The second exhaust gas aftertreatment device 36d is located above the first exhaust gas aftertreatment device 36a and is connected to the downstream side of the connecting pipe 36b. The second exhaust gas aftertreatment device 36d houses a urea selective reduction catalyst, an oxidation catalyst, etc. (none of which are shown). An exhaust port 36e is provided at the rear portion downstream of the second exhaust gas aftertreatment device 36d, protruding radially upward. The protruding end of the exhaust port 36e is connected to a tailpipe 38 (see Figure 1) formed on the upper surface cover 6a of the upper swirl body 6.

[0015] The urea selective reduction catalyst housed in the second exhaust gas aftertreatment device 36d selectively reduces nitrogen oxides (NOx) contained in the exhaust gas discharged from the engine 16 using ammonia generated from an aqueous urea solution as a reducing agent, decomposing them into nitrogen and water. Meanwhile, the oxidation catalyst housed in the second exhaust gas aftertreatment device 36d oxidizes the residual ammonia remaining after the nitrogen oxides have been reduced by the urea selective reduction catalyst, separating it into nitrogen and water. Here, the aqueous urea solution injection valve 36c is connected to the aqueous urea solution tank 40 via an aqueous urea solution pipeline and an aqueous urea solution pump (neither of which are shown). The aqueous urea solution tank 40 stores the aqueous urea solution, which is the reducing agent, and is mounted on a tank mounting base 42 provided on the upper side of the under cover 10a.

[0016] More specifically, the upstream heat exchanger chamber 46 is partitioned off as part of the machine room 44, which houses the engine 16, heat exchanger 20, exhaust gas purification device 36, etc., on the left rear side of the upper slewing body 6. The upstream heat exchanger chamber 46 is located upstream of the heat exchanger 20 in the direction of the cooling airflow from the cooling fan 18. Specifically, the upstream heat exchanger chamber 46 is partitioned off as a space enclosed by the under cover 10a of the slewing frame 10, the left inclined surface 14a of the counterweight 14, the heat exchanger 20, the left side cover 6b of the upper slewing body 6, and the top cover 6a (see Figure 1). The rear side of the upstream heat exchanger chamber 46 is a narrow triangular space due to the shape of the left inclined surface 14a of the counterweight 14, and the urea aqueous solution tank 40 is located in this triangular space.

[0017] FIG. 3 shows a perspective view of the hydraulic excavator 1 with a part of the working device 8 omitted, as seen from the left rear side. At a portion corresponding to the left inclined surface 14a of the counterweight 14, a maintenance opening 14b that enables access to the urea aqueous solution tank 40 is opened outward. The maintenance opening 14b is a rectangular opening extending in the vertical direction, and is used for performing maintenance such as liquid supply work on the urea aqueous solution tank 40, and is covered by a maintenance cover 14c that opens and closes between an open position where the maintenance opening 14b is opened and a closed position where the maintenance opening 14b is closed. An outside air inlet 14d for sucking outside air by the cooling fan 18 is formed in the maintenance cover 14c. Also, a side door 6c similar to the maintenance cover 14c is provided on the left side surface cover 6b of the upper swing body 6.

[0018] FIG. 4 shows a perspective view of the urea aqueous solution tank 40. The urea aqueous solution tank 40 is, for example, a container integrally formed using a resin material. The urea aqueous solution tank 40 is formed as thin as possible in order to increase its capacity as much as possible and reduce its weight. Specifically, the urea aqueous solution tank 40 is composed of an upper tank portion 40a having a larger capacity and a lower tank portion 40b disposed below the upper tank portion 40a and having a smaller capacity than the upper tank portion 40a. A supply port 48 for supplying the urea aqueous solution is formed in the upper tank portion 40a of the urea aqueous solution tank 40. The supply port 48 is closed by a removable lid 48a, and a receiving container 50 is attached to the peripheral wall 48b of the supply port 48.

[0019] Figure 5 shows a front view of the receiving container 50, Figure 6 shows a top view of the receiving container 50, and Figure 7 shows a side view of the receiving container 50. The receiving container 50 comprises a tray 52, a pocket 54, an outlet 54a, a drain pipe (tube) 56, and a drain hose (tube) 58. The receiving container 50 is a container in which the tray 52 and pocket 54 are integrally molded using an elastic material that is elastically deformable. The elastic material used for the receiving container 50 is, for example, EPDM (ethylene propylene diene rubber) or silicone, and a material having urea resistance and weather resistance is preferred.

[0020] The receiving tray 52 is provided surrounding the supply port 48 and receives the urea aqueous solution that leaks around the supply port 48. Specifically, the receiving tray 52 has an inclined surface 60 that slopes diagonally downward, a rectangular plate-like portion 52a on which the inclined surface 60 is formed, and wall portions 52b that are erected continuously at the upper end and left and right ends of the plate-like portion 52a. The plate-like portion 52a has mounting holes 52c that allow the receiving container 50 to be attached by fitting it into the peripheral wall 48b of the supply port 48. A cylindrical bush 62, for example made of rubber, is fitted into the mounting holes 52c. The receiving container 50 is fixed to the peripheral wall 48b without rattling via the bush 62 in the mounting holes 52c.

[0021] The pocket 54 is connected to the lower end of the tray 52, has a bottomed cylindrical shape, and has an upper opening 54b. The upper opening 54b is formed, for example, in a rectangular shape, and an outlet 54a is formed on the bottom surface 54c of the pocket 54. The bottom surface 54c is connected to the inner circumferential surface 54d of the pocket 54 and is formed to slope diagonally downward toward the outlet 54a. The outlet 54a discharges the urea aqueous solution collected in the pocket 54 to the bottom of the pocket 54. In this embodiment, a drain pipe 56 is connected to the outlet 54a, and a drain hose 58 is connected to the drain pipe 56. The drain hose 58 is fixed to the drain pipe 56 with a mounting bracket 64.

[0022] Figure 8 shows a schematic cross-sectional view of the urea solution tank 40 from the side during the liquid supply operation. During the urea solution supply operation, a storage container 70 for storing the urea solution is prepared, and the nozzle 70a of the storage container 70 is inserted into the supply port 48 of the urea solution tank 40 to supply the urea solution to the urea solution tank 40. At this time, the urea solution may drip from the tip of the nozzle 70a or spill from the supply port 48, causing droplets D of the urea solution to leak and scatter around the supply port 48 as shown in Figure 8. The receiving container 50 receives and collects the leaked and scattered urea solution. This prevents corrosion of metal and resin around the supply port 48 by the urea solution.

[0023] More specifically, first, the urea solution that leaks and splashes around the supply port 48 is received by the inclined surface 60 of the receiving tray 52. ​​Next, the urea solution that flows down the inclined surface 60 is collected at the upper opening 54b of the pocket 54. Then, the urea solution collected at the upper opening 54b is guided to the discharge port 54a by sequentially flowing down the inner circumferential surface 54d and the bottom surface 54c of the pocket 54. As mentioned above, the bottom surface 54c is formed with a diagonal downward slope toward the discharge port 54a, so the collected urea solution is efficiently guided to the discharge port 54a.

[0024] The urea aqueous solution guided to the discharge port 54a flows sequentially through the drain pipe 56 and drain hose 58, and is collected in a recovery container (not shown) located below the urea aqueous solution tank 40. Here, as shown in Figures 5 to 8, the pocket 54 formed in the receiving container 50 of this embodiment has a contact surface 54e that contacts the maintenance cover 14c shown in Figure 3 when it is closed. The contact surface 54e is the surface of the pocket 54 that faces from the upstream chamber 46 of the heat exchanger toward the maintenance opening 14b. The pocket 54 also has an expanded portion 66 formed from its bottom surface 54c toward the upper opening 54b. The expanded portion 66 is a part that gradually protrudes toward the maintenance opening 14b and includes the contact surface 54e.

[0025] Figure 9 shows a schematic cross-sectional view of the receiving container 50 from the side when the maintenance cover 14c is moved from the open position to the closed position. Note that the urea aqueous solution tank 40 is not shown in cross-section in Figure 9. In the state where the maintenance cover 14c is in the open position, as shown on the left side of Figure 9, the maintenance cover 14c is not in contact with the receiving container 50, and the pocket 54 is separated from the maintenance cover 14c. Therefore, the pocket 54 is not deformed, and space 68 is secured inside the pocket 54. Also, as shown on the left side of Figure 9, droplets D of the remaining urea aqueous solution are adhering to the inner circumferential surface 56a of the drain pipe 56.

[0026] On the other hand, when the maintenance cover 14c shown on the right side of Figure 9 is in the closed position, the maintenance cover 14c contacts the contact surface 54e of the pocket 54. That is, at least the pocket 54 of the receiving container 50 is positioned so that the maintenance cover 14c can contact it when the maintenance cover 14c is closed. As the maintenance cover 14c makes contact, the pocket 54 and thus the entire receiving container 50 vibrate, causing, for example, droplets D of the urea aqueous solution adhering to the inner circumferential surface 56a of the drain pipe 56 to flow down the inner circumferential surface 56a and be collected by flowing through the drain hose 58 as indicated by the arrow. The maintenance cover 14c is opened and closed each time the urea aqueous solution is supplied to the urea aqueous solution tank 40, and each time the maintenance cover 14c is closed, the maintenance cover 14c contacts the contact surface 54e. Each time this happens, the receiving container 50 is vibrated, and the vibration causes droplets D adhering to the inside of the pocket 54, drain pipe 56, or drain hose 58 to flow down. This suppresses the scaling of urea crystals.

[0027] Furthermore, in this embodiment, more preferably, when the maintenance cover 14c is closed, the pocket 54 is crushed by the maintenance cover 14c. This reduces the volume of the space 68 inside the pocket 54, generating a downward airflow F inside the pocket 54 as indicated by the arrow. The air pressure of this airflow F blows the droplets D of the urea aqueous solution adhering to the inner circumferential surface 56a of the drain pipe 56 downwards, and they flow through the drain hose 58 and are collected as indicated by the arrow. Therefore, the scaling of urea crystals can be suppressed even more reliably. In addition, because the pocket 54 has an expanded portion 66 including a contact surface 54e, the crushing of the pocket 54 is reliably performed when the maintenance cover 14c is closed. Furthermore, it is possible to further increase the air pressure of the airflow F, so the droplets D can be blown away even more effectively.

[0028] Furthermore, it is preferable to adjust the installation position, size, and shape of the pocket 54 so that when the pocket 54 is crushed by the maintenance cover 14c, the upper opening 54b is closed as shown in Figure 9. By making such adjustments, it is prevented that some of the airflow F generated when the pocket 54 is crushed leaks out from the upper opening 54b. This makes it possible to further increase the air pressure of the airflow F, thereby enabling more effective blowing away of the droplets D. On the other hand, since the pocket 54 is formed from the elastic material described above, when the maintenance cover 14c is opened again, the pocket 54 returns to its pre-crushing shape as shown on the left side of Figure 9. This makes it possible to recover the urea aqueous solution, which is the original function of the receiving container 50, during the urea aqueous solution supply operation.

[0029] On the other hand, if droplets D of urea aqueous solution adhere to the inner circumferential surface 54d of pocket 54, and the maintenance cover 14c remains closed for a long period of time, the pocket 54 may also be compressed for a long period of time. In such cases, urea crystals precipitated from the droplets D may cause opposing parts of the inner circumferential surface 54d inside pocket 54 to adhere to each other. In this case, even if the maintenance cover 14c is opened again, pocket 54 will not return to its shape before compression, and the urea aqueous solution cannot be collected in the receiving container 50.

[0030] Therefore, it is preferable to adjust the installation position, size, and shape of the pocket 54 so that when the pocket 54 is crushed by the maintenance cover 14c, a gap 72 is formed inside the pocket 54, as shown in Figure 9. This prevents adhesion of the inner circumferential surface 54d of the pocket 54 due to urea crystals, and thus ensures that the receiving container 50's original function of recovering the urea aqueous solution is reliably achieved during the urea aqueous solution supply operation.

[0031] Figure 10 shows a schematic side view of a receiving container 50 according to a different configuration, when it is attached to a urea aqueous solution tank 40. In this configuration, the receiving container 50 has a fold 74 formed on the side surface 54f of the pocket 54. The fold 74 can be formed by applying a creasing process during the formation of the pocket 54, or by partially reducing the thickness of the pocket 54. Specifically, when an inverted Y-shaped fold 74 as shown in Figure 10 is formed on the side surface 54f of the pocket 54, the pocket 54 easily deforms so that the side surface 54f of the pocket 54 folds when the pocket 54 is crushed by the maintenance cover 14c. By forming such a fold 74, deformation of the pocket 54 is promoted when the maintenance cover 14c is closed, and the crushing of the pocket 54 can be reliably performed.

[0032] As described above, in this embodiment, the hydraulic excavator 1 has a receiving container 50 attached to the supply port 48 of the urea aqueous solution tank 40 that supplies the urea aqueous solution, and the urea aqueous solution tank 40 is accessible by opening the maintenance cover 14c from the maintenance opening 14b of the machine room 44. The receiving container 50 has at least the aforementioned receiving tray 52, pocket 54, and discharge port 54a, and the pocket 54 has a contact surface 54e that contacts the maintenance cover 14c when it is closed.

[0033] When the maintenance cover 14c contacts the contact surface 54e, vibration is applied to the receiving container 50, causing droplets D of the urea aqueous solution adhering to the flow path of the urea aqueous solution, including the pocket 54, to flow down due to the vibration. This prevents corrosion of metal and resin around the supply port 48 by the urea aqueous solution, suppresses the scaling of urea crystals, and reduces the frequency of cleaning work to remove urea crystal scale. Therefore, the maintainability of the hydraulic excavator 1 can be improved.

[0034] Furthermore, the pocket 54 is formed from an elastic material and is compressed by the maintenance cover 14c when the maintenance cover 14c is closed. This reduces the volume of the space 68 inside the pocket 54, generating a downward airflow F inside the pocket 54. The air pressure of this airflow F blows away any droplets D of the urea aqueous solution adhering to the flow path of the urea aqueous solution, including the pocket 54.

[0035] Therefore, the scaling of urea crystals can be suppressed even more reliably, which further effectively reduces the frequency of cleaning work to remove urea crystal scale and further improves the maintainability of the hydraulic excavator 1. On the other hand, the pocket 54 returns to its shape before crushing when the maintenance cover 14c is open. Therefore, during the supply of urea aqueous solution, the original function of preventing leakage and splashing of the urea aqueous solution from the receiving container 50, and consequently recovering the urea aqueous solution, can be achieved.

[0036] Furthermore, the pocket 54 has an outlet 54a formed on its lower side for discharging the collected urea aqueous solution, and an extended portion 66 including a contact surface 54e that protrudes from the lower side toward the maintenance opening 14b. As a result, when the maintenance cover 14c moves from the open position to the closed position, the upper side of the pocket 54 is crushed before the lower side of the pocket 54, ensuring that the pocket 54 is crushed, and the air pressure of the airflow F can be further increased, allowing for even more effective blowing away of the droplets D. Therefore, the scaling of urea crystals can be suppressed even more reliably, making it possible to further effectively reduce the frequency of cleaning work for removing urea crystal scale, and further improving the maintainability of the hydraulic excavator 1.

[0037] Furthermore, a gap 72 is formed inside the pocket 54, and this gap 72 is maintained even when the pocket 54 is compressed by the maintenance cover 14c. This prevents urea crystals precipitated by the minute urea aqueous solution remaining after the removal of the droplet D from adhering to the inner surface 54d of the pocket 54. Therefore, during the supplying of the urea aqueous solution, the original function of preventing leakage and splashing of the urea aqueous solution from the receiving container 50, and consequently the recovery of the urea aqueous solution, can be more reliably achieved.

[0038] Furthermore, the receiving container 50 has a drain pipe 56 connected to the discharge port 54a and a drain hose 58 connected to the drain pipe 56. This ensures that the urea aqueous solution recovered in the receiving container 50 is reliably recovered in a recovery container located below the urea aqueous solution tank 40. Consequently, corrosion of metals and resins around the supply port 48 by the urea aqueous solution can be prevented even more reliably.

[0039] Furthermore, the receiving tray 52 has a mounting hole 52c into which the receiving container 50 can be attached by fitting it into the peripheral wall 48b of the supply port 48. A cylindrical bush 62 is fitted into the mounting hole 52c, and the receiving container 50 is fixed to the peripheral wall 48b via the bush 62 in the mounting hole 52c. This allows the receiving container 50 to be fixed to the supply port 48 of the urea aqueous solution tank 40 without rattling. Therefore, further improvement in the maintainability of the hydraulic excavator 1 can be expected.

[0040] Furthermore, the pocket 54 has a fold 74 that promotes deformation of the pocket 54 when it is crushed by the maintenance cover 14c. This allows the pocket 54 to deform easily when it is crushed by the maintenance cover 14c. Therefore, by forming the fold 74, deformation of the pocket 54 is promoted when the maintenance cover 14c is closed, and the crushing of the pocket 54 can be reliably performed. In addition, it is possible to further increase the air pressure of the airflow F, so that the droplets D can be blown away more effectively. Therefore, the scaling of urea crystals can be suppressed more reliably, so the frequency of cleaning work to remove urea crystal scale can be reduced more effectively, and the maintainability of the hydraulic excavator 1 can be further improved. [Explanation of Symbols]

[0041] 1. Hydraulic excavator (construction machinery) 14b Maintenance opening 14c Maintenance Cover 40 Urea solution tank 44 Machine room 48 supply ports 50 Receiving container 52 Saucer 54 pockets 54a Outlet 56. Drain pipe (tube) 58 Drain hose (pipe) 72 gaps 74 folds

Claims

1. The car body and, A urea aqueous solution tank is provided in the machine room located in the vehicle body, and the urea aqueous solution tank is stored in the urea aqueous solution tank. A receiving container attached to the supply port of the urea aqueous solution tank, A maintenance opening is formed in the machine room, which allows access to the urea aqueous solution tank, A maintenance cover that opens and closes between an open position that opens the maintenance opening and a closed position that closes the maintenance opening. Equipped with, The aforementioned receiving container is A tray is provided to surround the supply port and to receive the urea aqueous solution that leaks around the supply port, A cylindrical pocket connected to the aforementioned tray collects and discharges the urea aqueous solution that flows down the tray, and It has, The construction machine is characterized in that the pocket contacts the maintenance cover when the maintenance cover is in the closed position.

2. The construction machine according to claim 1, characterized in that the pocket is separated from the maintenance cover when the maintenance cover is in the open position.

3. The construction machine according to claim 1, characterized in that the pocket is crushed by the maintenance cover when the maintenance cover is in the closed position, and returns to its shape before crushing when the maintenance cover is in the open position.

4. The aforementioned pocket has an outlet formed on its lower side for discharging the collected urea aqueous solution, and protrudes from the lower side towards the maintenance opening. The construction machine according to claim 3, characterized in that when the maintenance cover moves from the open position to the closed position, the upper side of the pocket is crushed before the lower side of the pocket.

5. The construction machine according to claim 3, characterized in that a gap is formed inside the pocket, and the gap is maintained inside the pocket even when the pocket is crushed by the maintenance cover.

6. The aforementioned pocket has an outlet formed on its lower side. The construction machine according to claim 1, characterized in that the receiving container has a pipe connected to the discharge port.

7. The construction machine according to any one of claims 3 to 5, characterized in that the pocket has a fold that promotes deformation of the pocket when it is crushed by the maintenance cover.

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