Excavator

Abstract

To suppress blowback of a liquid reducing agent by suppressing air from being trapped inside a tank for the liquid reducing agent when supplying the liquid reducing agent.SOLUTION: An excavator according to an aspect of the present invention comprises an upper revolving body, an engine mounted on the upper revolving body, a revolving frame forming part of the upper revolving body, a liquid reducing agent tank mounted on the revolving frame, a filler attached to an upper portion of the liquid reducing agent tank, a first filter provided to cover a first opening present at a lower end of the filler, a pipe portion that connects the inside of the liquid reducing agent tank and the inside of the filler so that the gas in the liquid reducing agent tank is released when the liquid reducing agent is replenished from the filler to the liquid reducing agent tank. The pipe portion penetrates the liquid reducing agent tank above the lower end of the first opening.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to a shovel. [Background technology]

[0002] It has been known that an excavator is provided with an exhaust gas treatment device that purifies the exhaust gas from a diesel engine, which is a power source, and a liquid reducing agent tank that stores a liquid reducing agent used in the exhaust gas treatment device. Such a liquid reducing agent tank is provided with a filler, and the liquid reducing agent is supplied from the filler (for example, see the following cited document 1).

[0003] When liquid reducing agent is supplied from a filler to such a liquid reducing agent tank, a filter is often provided midway in the flow path from the filler to the inside of the liquid reducing agent tank to prevent foreign matter (debris) from entering the liquid reducing agent tank. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2015 / 053273 Summary of the Invention [Problem to be solved by the invention]

[0005] If a filter is provided midway along the flow path from the filler to the inside of the liquid reducing agent tank, the filter prevents foreign matter from entering the inside of the liquid reducing agent tank when the liquid reducing agent is being supplied. The foreign matter prevented from entering the inside of the liquid reducing agent tank accumulates in the filter. If foreign matter accumulates in the filter, the filter becomes clogged and it becomes difficult for air to escape from inside the liquid reducing agent tank to the outside when the liquid reducing agent is being supplied. If air cannot escape from inside the liquid reducing agent tank to the outside, the air inside the liquid reducing agent tank creates resistance, making it difficult for the liquid reducing agent to enter the inside of the tank, and there is a possibility that the liquid reducing agent will be blown back.

[0006] One aspect of the present invention provides a technique for suppressing a state in which air cannot escape from inside a liquid reducing agent tank when the liquid reducing agent is supplied, thereby suppressing the blow-back of the liquid reducing agent. [Means for solving the problem]

[0007] A shovel according to one aspect of the present invention includes an upper rotating body, An engine mounted on the upper rotating body; A revolving frame constituting a part of the upper revolving body; a liquid reducing agent tank mounted on the rotating frame; a filler attached to an upper portion of the liquid reducing agent tank; A first filter provided to cover a first opening at a lower end of the filler; a pipe portion connecting an inside of the liquid reducing agent tank and an inside of the filler so that gas in the liquid reducing agent tank is released when the liquid reducing agent is replenished from the filler to the liquid reducing agent tank; A second filter is disposed between the first opening and a second opening at an upper end of the filler. The pipe portion passes through the liquid reducing agent tank above a lower end of the first opening. The filler has a second through hole for inserting the tube portion, and the second filter is provided between a second opening at an upper end of the filler and the second through hole. . Effect of the Invention

[0008] An aspect of the present invention is to suppress a state in which air cannot escape from inside a liquid reducing agent tank when the liquid reducing agent is supplied, thereby suppressing blow-back of the liquid reducing agent. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a side view of a shovel according to an embodiment. [Diagram 2] FIG. 2 is a top view that diagrammatically illustrates an upper rotating body of the excavator in FIG. [Diagram 3] FIG. 3 is a diagram showing an example of the configuration of an exhaust gas treatment device mounted on the excavator of FIG. [Figure 4]FIG. 4 is a perspective view of a right front part of the shovel according to the embodiment, seen from diagonally above on the left. [Diagram 5] FIG. 5 is a side view of the right front part of the upper rotating body according to the embodiment, as viewed from the right side. [Figure 6] FIG. 6 is a perspective view of a right front part of a urea water tank provided in the excavator according to the embodiment, as viewed obliquely from above on the right. [Figure 7] FIG. 7 is a vertical cross-sectional view of the urea water tank according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment will be described with reference to the accompanying drawings. In order to facilitate understanding of the description, the same components in each drawing are denoted by the same reference numerals as much as possible, and duplicated description will be omitted.

[0011] In the following description, the positive X-axis direction and the negative X-axis direction are the front and rear of the shovel 100. The positive Y-axis direction and the negative Y-axis direction are the left and right of the shovel 100. The positive Z-axis direction and the negative Z-axis direction are the top and bottom of the shovel 100.

[0012] Fig. 1 is a side view of a shovel 100 according to one embodiment. As shown in Fig. 1, the shovel 100 includes a lower traveling structure 1, an upper rotating structure 2, a cabin 3, a boom 4, an arm 5, and a bucket 6.

[0013] The upper rotating body 2 is mounted on the lower traveling body 1 via a rotating mechanism (not shown). The cabin 3 is provided on the front left side of the upper rotating body 2. A driver's seat is provided inside the cabin 3. The boom 4 is rotatably provided in the center of the front part of the upper rotating body 2. The arm 5 is rotatably provided at the tip of the boom 4. The bucket 6 is an example of an end attachment, and is rotatably provided at the tip of the arm 5.

[0014] Fig. 2 is a top view that shows a schematic view of the upper rotating body 2 of the excavator 100 in Fig. 1. As shown in Fig. 2, an engine room 7 is formed in the upper rotating body 2. A diesel engine 8 (one example of an "engine") is installed in the engine room 7. A cooling fan 12 is installed to the left of the diesel engine 8 (the positive side of the Y axis). A heat exchanger unit 13 including a radiator and the like is installed to the left of the cooling fan 12 (the positive side of the Y axis).

[0015] Furthermore, the diesel engine 8 draws in outside air through an air filter 9a and an intake pipe 9b installed outside the engine compartment 7. Furthermore, an exhaust pipe 9c is connected to the diesel engine 8. An exhaust gas treatment device 10 that purifies nitrogen oxides (hereinafter referred to as NOx) in the exhaust gas discharged from the diesel engine 8 is installed downstream of the exhaust pipe 9c.

[0016] In this embodiment, the exhaust gas treatment device 10 is a urea selective reduction type NOx treatment device that uses urea water as a reducing agent. The exhaust gas treatment device 10 reduces NOx (nitrogen oxides) in the exhaust gas by injecting urea water upstream of a reduction catalyst (not shown) provided in the exhaust pipe 9c, and the reduction reaction is promoted by the reduction catalyst to render the NOx harmless.

[0017] On the right side of the upper rotating body 2 and in front of the engine room 7, a urea water tank 20, a fuel tank 19, and a hydraulic oil tank 18 are arranged in this order from the front. The urea water tank 20 (an example of a "liquid reducing agent tank") is a container for storing urea water. The urea water tank 20 is connected to the exhaust gas treatment device 10 via a urea water supply line 69 and a urea water supply pump 70.

[0018] Fig. 3 is a diagram showing an example of the configuration of the exhaust gas processing device 10 mounted on the excavator 100 of Fig. 1. The diesel engine 8 is controlled by an engine control module (hereinafter referred to as "ECM") 60.

[0019] The air introduced into the intake pipe 9b through the air filter 9a passes through the turbocharger 61, the intercooler 65, etc., and is supplied to the diesel engine 8. Then, the exhaust gas from the diesel engine 8 passes through the turbocharger 61 and reaches the exhaust pipe 9c downstream thereof, where it is purified by the exhaust gas treatment device 10 and then discharged into the atmosphere.

[0020] A diesel particulate filter 66 that collects particulate matter in the exhaust gas and a selective reduction catalyst 67 that reduces and removes NOx in the exhaust gas are provided in series in the exhaust pipe 9c.

[0021] The selective reduction catalyst 67 receives a supply of a reducing agent and continuously reduces and removes NOx in the exhaust gas. In this embodiment, urea water (urea aqueous solution) is used as the reducing agent because of its ease of handling.

[0022] A urea water injector 68 for supplying urea water to the selective reduction catalyst 67 is provided on the upstream side of the selective reduction catalyst 67 in the exhaust pipe 9c. The urea water injector 68 is connected to the urea water tank 20 via a urea water supply line 69.

[0023] A supply module (hereinafter, referred to as "SM") is provided in the middle of the urea water supply line 69. The SM includes a urea water supply pump 70 and a filter 71. In this embodiment, the SM is configured such that the filter 71 is disposed between the urea water tank 20 and the urea water supply pump 70.

[0024] The urea water stored in the urea water tank 20 is supplied to the urea water injector 68 by the urea water supply pump 70, and is injected from the urea water injector 68 to a position upstream of the selective reduction catalyst 67 in the exhaust pipe 9c.

[0025] The urea water injected from the urea water injector 68 is supplied to the selective reduction catalyst 67. The supplied urea water is hydrolyzed in the selective reduction catalyst 67 to generate ammonia. This ammonia reduces NOx contained in the exhaust gas in the selective reduction catalyst 67. In this manner, the exhaust gas is purified.

[0026] The first NOx sensor 72 and the second NOx sensor 73 are sensors that detect the NOx concentration in the exhaust gas. In this embodiment, the first NOx sensor 72 is disposed upstream of the urea water injector 68, and the second NOx sensor 73 is disposed downstream of the selective reduction catalyst 67.

[0027] The urea water remaining amount sensor (an example of a detection device) 74 is a sensor that detects the amount of urea water remaining in the urea water tank 20 and obtains information on the amount of urea water remaining. In this embodiment, the urea water remaining amount sensor 74 is a so-called float type sensor that is installed inside the tank so as to be movable in the vertical direction and detects the amount of urea water remaining based on the position of a float floating on the liquid surface, but other types may also be used. The urea water remaining amount sensor 74 outputs information on the amount of urea water remaining to the exhaust gas controller 75.

[0028] Urea quality sensor (an example of a detection device) 25 is a sensor that detects the quality including the components of the urea water in the urea water tank 20, and obtains information on the quality of the urea water. Urea quality sensor 25 outputs the information on the urea quality to exhaust gas controller 75.

[0029] In the present embodiment, an example has been described in which information on the remaining amount of urea water and information on urea quality are shown as information on the urea water (liquid reducing agent) inside the urea water tank (an example of a tank for a liquid reducing agent) 20. However, in the present embodiment, the information on the urea water (liquid reducing agent) is not limited to information on the remaining amount of urea water and information on urea quality, and any information may be used as long as it shows the results of measurement on the urea water inside the urea water tank (an example of a tank for a liquid reducing agent) 20.

[0030] The first NOx sensor 72, the second NOx sensor 73, the urea water remaining amount sensor 74, the urea quality sensor 25, the urea water injector 68, and the urea water supply pump 70 are connected to an exhaust gas controller 75. The exhaust gas controller 75 controls the urea water injector 68 and the urea water supply pump 70 based on the NOx concentrations detected by the first NOx sensor 72 and the second NOx sensor 73, respectively, so that an appropriate amount of urea water is injected.

[0031] Further, the exhaust gas controller 75 calculates the ratio of the remaining amount of urea water to the total volume of the urea water tank 20 based on the remaining amount of urea water output from the urea water remaining amount sensor 74. In this embodiment, the ratio of the remaining amount of urea water to the total volume of the urea water tank 20 is referred to as the urea water remaining amount ratio. For example, a urea water remaining amount ratio of 50% indicates that half the capacity of the urea water tank 20 of the urea water remains in the urea water tank 20.

[0032] The exhaust gas controller 75 is connected to the ECM 60 via a communication means. The ECM 60 is also connected to a shovel controller 76 via a communication means, and the shovel controller 76 is also connected to a monitor 77 via a communication means. The monitor 77 displays warnings, operating conditions, and the like.

[0033] The exhaust gas controller 75 can also be called a DCU (Dosing Control Unit), the ECM 60 can also be called an ECU (Engine Control Unit), and the shovel controller 76 can also be called an MCU (Main Control Unit).

[0034] The exhaust gas controller 75 is configured to be able to share various information related to the exhaust gas processing device 10 with the shovel controller 76. Each of the ECM 60, the exhaust gas controller 75, and the shovel controller 76 is a computing device including a CPU, a RAM, a ROM, an input / output port, a storage device, and the like.

[0035] The exhaust gas treatment device 10 also has a heat supply function for supplying heat to the urea water tank 20 and the urea water supply line 69. The heat supply function is performed, for example, to prevent the urea water from freezing in cold regions or to melt frozen urea water. In this embodiment, engine cooling water (for example, long-life coolant) of the diesel engine 8 passing through a cooling water pipe 80 is used.

[0036] Specifically, the engine cooling water immediately after cooling the diesel engine 8, while maintaining a relatively high temperature, passes through a first portion 81 of the piping 80 to reach a second portion 82. The second portion 82 is a part of the piping 80 that contacts the outer surface of the urea water tank 20. As the engine cooling water, which is at a higher temperature than the urea water, flows through the second portion 82, it supplies heat to the urea water tank 20 and the urea water contained therein.

[0037] The engine cooling water then reaches the third portion 83 and the SM. The third portion 83 is a part of the piping 80 that is in close contact with the urea water supply line 69. When the engine cooling water, which is hotter than the urea water, flows through the third portion 83 of the piping 80 along the urea water supply line 69, it supplies heat to the urea water supply line 69 and the urea water therein. In addition, when the engine cooling water, which is hotter than the urea water, flows through a flow path formed in the SM, it supplies heat to the SM (including the urea water supply pump 70 and the filter 71) and the urea water therein.

[0038] Thereafter, the engine coolant, which has become relatively low in temperature after having received heat from the second portion 82 and the third portion 83, passes through a fourth portion 84 of the piping 80 and reaches the heat exchanger unit 13 (see FIG. 2). The fourth portion 84 is a part of the piping 80 that is routed between the heat exchanger unit 13 and the third portion 83 and fifth portion 85, and is not in close contact with the urea water supply line 69.

[0039] The fifth portion 85 is a part of the piping 80 used to cool the urea water injection device 68. When the engine cooling water, which is at a lower temperature than the urea water injection device 68 in a high temperature state, flows through the fifth portion 85, it absorbs heat from the urea water injection device 68 in a high temperature state, thereby cooling the urea water injection device 68 and preventing it from overheating. After that, the engine cooling water (which is at a higher temperature than the urea water) that has been supplied with heat and has become a relatively high temperature supplies heat to the urea water supply line 69 and the urea water therein when it flows through the portion 85a along the urea water supply line 69. When the urea water injection device 68 is in a low temperature state, the engine cooling water, which is at a higher temperature than the urea water injection device 68 in a low temperature state, supplies heat to the urea water injection device 68 and the urea water therein when it flows through the fifth portion 85. After that, after having supplied heat in section 85a and now at a relatively low temperature, the engine cooling water merges with the engine cooling water that has flowed through the third section 83 and then passes through the fourth section 84 to reach the heat exchanger unit 13.

[0040] In this way, the heat supply function utilizes the engine cooling water to supply heat to the urea water tank 20, the urea water supply line 69, the SM, and the urea water injector 68, thereby preventing the urea water inside them from freezing or melting any frozen urea water.

[0041] Next, the right front part of the upper rotating body 2 will be described in detail with reference to Fig. 4 and Fig. 5. Fig. 4 is a perspective view of the right front part of the excavator 100 as seen diagonally from above and to the left. Fig. 5 is a side view of the right front part of the upper rotating body 2 as seen from the right side. Fig. 5 shows the inside of the lifting equipment 30 in a see-through manner.

[0042] The lifting equipment 30 is a structure used when an operator ascends or descends the upper rotating body 2. In this embodiment, the lifting equipment 30 is disposed in front of the fuel tank 19, and covers the urea water tank 20 and the storage section 21.

[0043] The fuel tank 19 is a tank in which fuel for the diesel engine 8 is stored, and is firmly fixed to a revolving frame 31 that constitutes a part (bottom plate) of the upper revolving body 2. In addition, a fuel tank undercover 31v is attached below the fuel tank 19. The fuel tank undercover 31v is fastened and fixed to the revolving frame 31 by fastening members such as bolts that are accessible from the outside (bottom side).

[0044] The urea water tank 20 is a tank that stores an aqueous urea solution as a liquid reducing agent used in an SCR system (selective catalytic reduction system), and is firmly fixed to the revolving frame 31. In addition, a urea water tank undercover 31w is attached below the urea water tank 20. The urea water tank undercover 31w is fastened and fixed to the revolving frame 31 by fastening members such as bolts that are accessible from the outside (bottom side), similar to the fuel tank undercover 31v. Note that an engine undercover (not shown) attached below the engine, a radiator undercover (not shown) attached below the radiator, and the like are also fastened and fixed to the revolving frame 31 by fastening members such as bolts that are accessible from the outside (bottom side).

[0045] The storage section 21 is a collection of members that divide a storage space, and may take the form of a box, container, partition, or the like. In this embodiment, the storage section 21 is disposed on the opposite side of the cabin 3 across the boom 4 in the upper rotating body 2. The storage section 21 has a storage space 21a that is divided by a lifting equipment 30 and a rotating frame 31. The storage space 21a stores items 21b, such as tools used during maintenance and a fuel pump. A bottom plate 32 is attached below the storage section 21. The storage space 21a and the space in which the urea water tank 20 is disposed may be divided by a plate, or the spaces may be connected without a plate.

[0046] As shown in Fig. 4, a pair of left and right support brackets 17 for mounting the booms are erected in front of the revolving frame 31 of the upper revolving body 2. A fuel tank 19 and a lifting equipment 30 are disposed to the right of the support bracket 17. Handrails 33 are provided on the outside of the lifting equipment 30 for an operator to hold on to when ascending or descending the lifting equipment 30.

[0047] The lifting equipment 30 has a first lifting section 30A and a second lifting section 30B. The first lifting section 30A functions as a step for an operator to ascend and descend, and also functions as a cover for covering the urea water tank 20 and as part of the storage section 21. The second lifting section 30B is located at the lowest level of the lifting equipment 30. The second lifting section 30B is made of metal, and is fixed to the revolving frame 31. The second lifting section 30B protrudes forward from the front end portion of the revolving frame 31.

[0048] The lifting equipment 30 has a three-stage structure including two step sections 44, 45 and two riser sections 48, 49 in the first lifting section 30A and the second lifting section 30B. Note that the number of step sections provided in the first lifting section 30A is not limited to two.

[0049] The step board portion 44 is configured as an opening / closing portion that can be opened and closed. In this embodiment, the step board portion 44 is configured to open upward as shown in Fig. 5. By opening the step board portion 44, a worker can put tools in and take them out of the storage portion 21. The step board portion 44 can be locked with a key 44a.

[0050] In addition, the riser plate portion 49 is configured as an opening / closing portion that can be opened and closed. In this embodiment, the riser plate portion 49 is configured to open sideways. An operator can access the filler 22 of the urea water tank 20 by opening the riser plate portion 49.

[0051] The urea water tank 20 is mounted on a revolving frame 31 at the front right side of the upper revolving body 2.

[0052] The urea water tank 20 is disposed adjacent to and in front of the fuel tank 19 on the rotating frame 31 at the front right side of the upper rotating body 2. The urea water tank 20 is also disposed adjacent to and rear of the storage unit 21 disposed at the front end of the upper rotating body 2. In other words, the urea water tank 20 is disposed on the rotating frame 31 at the front right side of the upper rotating body 2, between the storage unit 21 and the fuel tank 19 in the front-rear direction.

[0053] In the storage section 21 adjacent to the front of the urea water tank 20, in addition to tools required for maintenance and inspection of the excavator, for example, electrically-powered devices such as an oil supply pump 140 may be stored.

[0054] Fig. 6 is a perspective view of the right front part of the urea water tank 20 provided in the excavator 100 of this embodiment, viewed from diagonally above to the right. The external shape of the urea water tank 20 will be described with reference to Fig. 6 in addition to Fig. 5.

[0055] 6, the urea water tank 20 has a generally rectangular cross section, is generally box-shaped overall, and includes a filler 22 and a lid unit 42. The main body of the urea water tank 20 is made of, for example, resin. Alternatively, a tank storage container may be provided on the swivel frame 31, and the tank storage container may be fastened to the swivel frame 31 to store the urea water tank 20 in the tank storage container. In this case, the tank storage container may be made of, for example, steel.

[0056] A liquid supply port 20h for supplying urea water to the inside of the urea water tank 20 is provided on the front side (X-axis positive side) of the tank top surface 20a of the urea water tank 20, and a filler 22 is attached to the liquid supply port 20h. The urea water is supplied to the inside of the urea water tank 20 through the filler 22.

[0057] A rear opening is provided on the rear side (X-axis negative side) of the tank top surface 20a of the urea water tank 20 to guide cooling water into the urea water tank 20, and a lid unit 42 is provided at the rear opening.

[0058] An air breather hose 41 is provided between the filler 22 and the lid unit 42. The air breather hose 41 will be described later.

[0059] The relay bracket 78 is fixed to the front surface of the fuel tank 19. The relay bracket 78 and the lid unit 42 are connected by two signal lines 74a, 25a (a signal line 74a for the urea water remaining sensor 74 and a signal line 25a for the urea quality sensor 25). The relay bracket 78 converts the signals transmitted from the signal lines 74a, 25a into data that can be identified by the exhaust gas controller 75, and transmits the data to the exhaust gas controller 75.

[0060] An adapter 28 is provided at the upper end of the filler 22. A plurality of fixing screws 28a are threaded through a flange provided at the lower end of the adapter 28 and are screwed into a plurality of nuts embedded in the flange provided at the upper end of the filler 22. This allows the adapter 28 to be fixed to the filler 22 by the screws. A strainer 28A is also fitted to the adapter 28.

[0061] Furthermore, a filler cap 23 is provided at the upper end of the adapter 28 .

[0062] The operator removes the filler cap 23 from the filler 22 and pours the urea water from the upper opening of the filler 22. As a result, the urea water is replenished into the urea water tank 20 via the filler 22.

[0063] Further, the tank top surface 20a of the urea water tank 20 is provided with pipe attachment ports 20i1 and 20i2.

[0064] The piping mounting port 20i1 is connected to a urea water supply line 69 (see FIG. 3) inside the urea water tank 20, and is connected to a urea water supply line 69 (see FIG. 3) outside the urea water tank 20. In reality, two piping mounting ports 20i1 are provided on the tank top surface 20a, and one of the piping mounting ports 20i1 is connected to a urea water supply line 69 for taking out the urea water from the urea water tank 20, and the other piping mounting port 20i1 is connected to a urea water supply line 69 for returning the urea water to the urea water tank 20.

[0065] The pipe mounting port 20i2 is connected to a pipe 80 inside the urea water tank 20, and is connected to a pipe 80 outside the urea water tank 20. In reality, two pipe mounting ports 20i2 are provided on the tank top surface 20a, and one pipe mounting port 20i2 is used to discharge the cooling water that has circulated inside the urea water tank 20 from the pipe 80 inside the urea water tank 20, and the other pipe mounting port 20i2 is used to feed the cooling water circulating inside the urea water tank 20 to the pipe 80 inside the urea water tank 20.

[0066] Fig. 7 is a vertical cross-sectional view of the urea water tank 20. The structure of the urea water tank 20 will now be described in detail with reference to Fig. 7.

[0067] The main body of the urea water tank 20 is made of resin and has a substantially rectangular parallelepiped shape. The urea water tank 20 has a tank top surface 20a, a tank bottom surface 20b, a tank front surface 20c, a tank rear surface 20d, and a pair of tank side surfaces (not shown).

[0068] A liquid supply port 20h is formed in the tank upper surface 20a. A filler 22 is provided in the liquid supply port 20h so as to protrude upward. A liquid level regulating member 22d is provided in the filler 22 so as to protrude downward.

[0069] The filler 22 is attached to the top of the urea water tank 20 (an example of a tank for a liquid reducing agent) and guides the urea water to a liquid supply port 20h of the urea water tank 20 when refilling the urea water tank 20. The filler 22 is fixed to the tank top surface 20a by a fixing screw 22c. An adapter 28 is fixed to the upper end of the filler 22 by a fixing screw 28a. A filler cap 23 is detachably provided on an upper end opening (an example of a second opening) at the upper end of the adapter 28. The filler 22 is provided with a planar rib 24 extending in the Z-axis direction and the X-axis direction. The rib 24 supports forces in the height direction (Z-axis direction) and the front-rear direction (X-axis direction) of the filler 22.

[0070] The filler cap (an example of a second lid) 23 is provided with an air breather (not shown). Since the filler cap 23 is provided with the air breather, while the filler cap 23 is attached to the filler 22, the air inside the urea water tank 20 can be released to keep the internal pressure constant, and also dust, dirt, etc. can be prevented from entering the inside of the urea water tank 20 from the outside.

[0071] A rear opening is provided on the tank top surface 20a of the urea water tank 20, and a lid unit (an example of a first lid) 42 that closes the rear opening is provided on the rear opening.

[0072] A urea water remaining amount sensor 74 and two signal wires 74a, 25a are attached to the lid unit 42. The two signal wires 74a, 25a connect the urea water remaining amount sensor 74 and the urea quality sensor 25 to a relay bracket 78 so as to be able to communicate with each other.

[0073] The lid unit 42 is provided with a plurality of through holes penetrating between its upper and lower surfaces, i.e., between the outside and the inside of the urea water tank 20, through which a pipe 80 for engine cooling water for heating the urea water, a urea water supply line 69, a urea water return line (not shown), a port 41c (an example of a connecting member) for the air breather hose 41, and the like are inserted. That is, the pipe 80, the urea water supply line 69, the urea water return line, the port 41c, and the like penetrate between the inside and the outside of the urea water tank 20 in the lid unit 42. That is, the plurality of through holes provided in the lid unit 42 of the urea water tank 20 include a through hole (an example of a first through hole) for inserting the port 41c for the air breather hose 41.

[0074] The urea water return line (not shown) is used to return the urea water that has not been supplied from the urea water supply pump 70 to the urea water injector 68, i.e., unused urea water, to the urea water tank 20.

[0075] Thus, the lid unit 42 has the port 41c for the air breather hose 41, and supports the two signal lines 74a, 25a, the piping 80, the urea water supply line 69, and the urea water return line (not shown), etc.

[0076] A strainer (an example of a second filter) 28A is provided between the adapter 28 and the filler 22. The strainer 28A has a generally cylindrical shape with an outer diameter smaller than the inner diameter of the filler 22, and is disposed inside the cylinder of the filler 22. The strainer 28A is, for example, a metal mesh filter, and removes foreign matter contained in the urea water poured from the upper opening of the adapter 28. In this way, the strainer 28A suppresses the intrusion of foreign matter into the urea water tank 20.

[0077] The liquid level regulating member 22d guides the urea water into the urea water tank 20 and regulates the liquid level of the urea water refilled into the urea water tank 20. The urea water is refilled into the urea water tank 20 from the liquid supply port 20h via a filler 22 having the liquid level regulating member 22d.

[0078] Further, a drain plug 27 is provided on a tank bottom surface 20b of the urea water tank 20. The drain plug 27 is removed when the urea water remaining in the urea water tank 20 is to be drained.

[0079] The urea water remaining amount sensor 74 detects the position of the liquid level directly below the pipe mounting port 20i1. The urea water supply line 69 extends directly downward from the pipe mounting port 20i1 and sucks up the urea water at the center of the tank bottom surface 20b. A signal line 74a is connected to the urea water remaining amount sensor 74, and this signal line 74a is drawn out from the tank top surface 20a of the urea water tank 20 to the outside and connected to the exhaust gas controller 75 via a relay bracket 78 (see FIG. 6) fixed to the front surface of the fuel tank 19.

[0080] A second portion 82 of the pipe 80 extends directly downward from the pipe attachment ports 20i1, 20i2, bends at a substantially right angle near the tank bottom surface 20b, and extends along the tank bottom surface 20b.

[0081] Urea quality sensor 25 is installed near the bent portion of second portion 82 of piping 80. A signal wire 25a is connected to urea quality sensor 25, and this signal wire 25a is drawn out from tank top surface 20a of urea water tank 20 to the outside and connected to exhaust gas controller 75 via relay bracket 78 (see FIG. 6) fixed to the front surface of fuel tank 19.

[0082] In this embodiment, the urea quality sensor 25 is disposed near a bent portion of a pipe (second portion 82 of the pipe 80) through which antifreeze liquid for thawing the urea water inside the urea water tank 20 passes. This allows liquefied urea water to always be present around the urea quality sensor 25, and prevents the urea water from directly hitting the sensor during water supply, allowing stable measurement of the quality of the urea water.

[0083] As shown in Fig. 7, the full water level position A2, which is determined to be full by the urea water remaining amount sensor 74, is slightly lower than the liquid level regulation position A1. This allows the urea water remaining amount sensor 74 to detect the full water level before the urea water reaches the liquid level regulation position A1, thereby avoiding a problem in which the full water level cannot be detected for a long time. The full water level position A2 may be the same position as the liquid level regulation position A1.

[0084] An inlet filter (an example of a first filter) 43 is provided at a lower end opening (an example of a first opening) present at the lower end of the liquid level regulating member 22d of the filler 22.

[0085] The inlet filter 43 is, for example, a bag-shaped filter made of woven fabric, and is fixed to the vicinity of the lower end of the liquid level regulating member 22d by a resin cable tie 47.

[0086] On the other hand, the strainer 28A is provided between a lower end opening of the filler 22 (an example of a first opening) and an upper end opening of the filler 22 (an example of a second opening).

[0087] Therefore, inlet filter 43 is a filter provided downstream of strainer 28A, and removes fine foreign matter passing through strainer 28A. In other words, the mesh size of strainer 28A (an example of the second filter) is larger (coarser) than that of inlet filter 43 (an example of the first filter).

[0088] The inlet filter 43 removes fine foreign matter from the urea water that has flowed in from the filler 22, and allows the urea water to flow out into the urea water tank 20. As the urea water flows into the urea water tank 20, air inside the urea water tank 20 is discharged from the filler 22 via the inlet filter 43.

[0089] In this manner, in a situation where no foreign matter has accumulated in the inlet filter 43, air is discharged as the urea water flows in.

[0090] However, when foreign matter 43a accumulates in the inlet filter 43, for example, the foreign matter 43a suppresses the flow of the urea water, thereby obstructing the flow of the urea water along the direction 603. In such an example, the urea water flows into the urea water tank 20 along the directions 601 and 602. In general, air passes through a portion of the inlet filter 43 above the portion into which the urea water flows, and is discharged from the filler 22.

[0091] For this reason, as foreign matter accumulates in the inlet filter 43, the area through which air can pass becomes narrower. In such a situation, when urea water is supplied from the filler 22, the air inside the urea water tank 20 cannot escape to the outside of the urea water tank 20 and functions as a resistance to the inflowing urea water inside the urea water tank 20. As a result, there is a possibility that the urea water will be blown back when the water is supplied.

[0092] Therefore, in this embodiment, an air breather hose 41 (an example of a pipe section) is connected between the lid unit 42 of the urea water tank 20 and the filler 22. In other words, the air breather hose 41 (an example of a pipe section) connects the inside of the urea water tank 20 and the inside of the filler 22 so that air (an example of a gas) in the urea water tank 20 is released when urea water (an example of a liquid reducing agent) is refilled from the filler 22 to the urea water tank 20. In this manner, the air breather hose 41 is connected to the lid unit 42 of the urea water tank 20, and therefore penetrates the filler 22 above the lower end opening (an example of a first opening). Therefore, the air breather hose 41 can release only the air in the urea water tank 20.

[0093] The air breather hose 41 includes, for example, a hollow, flexible rubber hose body 41b to allow air to pass through, and also includes ports 41a and 41c at the ends of the hose body 41b. Specifically, the air breather hose 41 is formed by inserting both ends of the hose body 41b into the ports 41a and 41c and fixing them with fasteners or the like.

[0094] The port 41a has a substantially cylindrical shape. The port 41a is erected on the outer circumferential surface of the filler 22, with one end thereof opening to the inside of the body of the filler 22 and the other end thereof opening to the outside of the body of the filler 22. That is, the port 41a communicates with the inside and outside of the substantially cylindrical shape of the filler 22 via a through hole (an example of a second through hole) formed between them.

[0095] The through-hole (an example of a second through-hole) is provided downstream of the strainer 28A. As a result, air discharged from the through-hole is discharged to the outside through the strainer 28A. In other words, since the strainer 28A is provided between the outside and the through-hole, it is possible to prevent foreign matter from entering the urea water tank 20 through the through-hole.

[0096] Moreover, the through hole (an example of a second through hole) is provided at a position closer to the upper end opening of the filler 22 than to the lower end opening of the filler 22, and the port 41a faces upward. In other words, since the through hole (an example of a second through hole) is provided near the upper end opening of the filler 22, it is easy to discharge the air discharged from the through hole to the outside, and also prevents the urea water from flowing into the air breather hose during water supply. This makes it possible to suppress air in the urea water tank 20 from becoming a resistance, and improve the water supply efficiency.

[0097] In this embodiment, the port 41a is described as being molded integrally with the filler 22, but the port 41a may be molded separately from the filler 22 and then joined to the outer peripheral surface of the filler 22 by welding or the like.

[0098] The port 41c is, for example, a resin tube and is inserted into the lid unit 42, but may be molded integrally with the lid unit 42. The port 41c has a through hole for discharging air through the air breather hose 41. A bent portion that is bent 90 degrees is provided near one end of the port 41c. The port 41c is a tube member whose other end protrudes in the negative direction of the Z axis, and the other end is formed at approximately the same height as the liquid level regulating member 22d. As a result, the port 41c realizes the same function as the liquid level regulating member 22d and regulates the height position of the liquid level of the urea water refilled in the urea water tank 20. The other end is not limited to being formed at approximately the same height as the liquid level regulating member 22d, and may be above the liquid level regulating member 22d.

[0099] The air breather hose 41 is a pipe portion having one end into which the port 41a is inserted and the other end inserted into one end side near the bent portion of the port 41c. As a result, the air breather hose 41 connects a through hole provided in the upper part of the urea water tank 20 and a through hole provided in the filler 22, so that air can move between the inside of the urea water tank 20 and the inside of the filler 22 without passing through the inlet filter 43.

[0100] Specifically, when the urea water tank 20 is being supplied with the urea water, the air breather hose 41 takes in air present below (in the negative direction of the Z axis) substantially the same height as the liquid level regulating member 22d through the port 41c, and discharges the air through the port 41a to the filler 22. The air discharged to the filler 22 is discharged to the outside of the urea water tank 20 via the strainer 28A.

[0101] Therefore, in the urea water tank 20 according to this embodiment, when the urea water is being supplied, the urea water passes through the inlet filter 43, thereby preventing foreign matter from entering the urea water tank 20. Even if foreign matter accumulates in the inlet filter 43 and it becomes difficult for the air inside the urea water tank 20 to be discharged to the outside of the urea water tank 20 through the inlet filter 43 when the urea water is being supplied, the air inside the urea water tank 20 can be discharged to the outside of the urea water tank 20 through the air breather hose 41.

[0102] In the urea water tank 20 according to this embodiment, an example has been described in which a through hole for inserting the port 41c is provided in the lid unit 42. However, in this embodiment, the position where the through hole is provided is not limited to the lid unit 42, and may be any position as long as it is in the tank top surface 20a of the urea water tank 20.

[0103] (Modification) In the above-described embodiment, an example has been shown in which a through hole for inserting the port 41c is provided in the lid unit 42 of the urea water tank 20. The position where the through hole is provided is not limited to the tank top surface 20a of the urea water tank 20, and the through hole may be provided in any one of the tank front surface 20c, the tank rear surface 20d, and a pair of tank side surfaces (not shown). Note that the other configurations are the same as those in the above-described embodiment, and therefore description thereof will be omitted.

[0104] For example, a through hole is provided above the liquid level regulating position A1 in the tank rear surface 20d shown in Fig. 7. A port 41c' is inserted into the through hole. The air breather hose 41 is formed by inserting an end of a hose body 41b into the port 41c' and fixing it with a fastener or the like.

[0105] The port 41c' is, for example, a resin pipe and is inserted into a through hole (an example of a first through hole) provided in the tank rear surface 20d in the X-axis direction. A through hole is formed in the port 41c' for discharging air via the air breather hose 41. The through hole (an example of a first through hole) provided in the tank rear surface 20d in the X-axis direction penetrates above the lower end opening of the filler 22 (an example of the lower end of the first opening).

[0106] The port 41c' is provided with a bent portion that is bent 90 degrees from the X-axis direction to the negative Z-axis direction inside the urea water tank 20. The end of the port 41c after bending at the bent portion is formed at the same height as the lower end opening of the filler 22 (an example of the lower end of the first opening). As a result, the port 41c' realizes a function similar to that of the liquid level regulating member 22d and regulates the height position of the liquid level of the urea water refilled in the urea water tank 20. For this reason, in this modified example, a through hole provided in the tank rear surface 20d in the X-axis direction is formed above the lower end opening of the filler 22. The end of the port 41c after bending at the bent portion is not limited to being formed at approximately the same height as the liquid level regulating member 22d, and may be above the liquid level regulating member 22d.

[0107] In this modified example, an example in which a through hole is provided in the tank rear surface 20d has been described, but the present invention is not limited to the method of providing a through hole in the tank rear surface 20d, and a through hole may be provided in the tank front surface 20c or the tank side surface. The port used when a through hole is provided in the tank front surface 20c or the tank side surface is the same as the port 41c' inserted in the tank rear surface 20d, and a description thereof will be omitted. Even with the configuration of this modified example, the same effects as those of the above-mentioned embodiment can be achieved.

[0108] In the above-described embodiment and modified example, the filler 22 of the urea water tank 20 and the lid unit 42 provided on the upper part of the urea water tank 20 are connected by an air breather hose 41. As a result, when the urea water is supplied, the air inside the urea water tank 20 is discharged to the outside from the filler 22 via the air breather hose 41 without passing through the inlet filter 43 provided on the lower end of the filler 22. This prevents the air inside the urea water tank 20 from becoming a resistance, and suppresses the blow-back of the urea water.

[0109] Furthermore, even if foreign matter accumulates in the inlet filter 43, the air in the urea water tank 20 can be discharged, which extends the period until the inlet filter 43 needs to be replaced. This reduces the burden of maintaining the urea water tank 20, and reduces costs by reducing the need to replace the inlet filter 43.

[0110] Furthermore, a port 41c that connects to the air breather hose 41 is provided in the lid unit 42. The lid unit 42 is provided to support the signal lines 74a, 25a, the piping 80, etc., and therefore can prevent the provision of a new through hole in the main body of the urea water tank 20. Therefore, with the urea water tank 20 according to this embodiment, it is possible to prevent the urea water tank 20 from being given a new shape, thereby improving maintainability.

[0111] Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment. Various changes, modifications, substitutions, additions, deletions, and combinations are possible within the scope of the claims. These naturally fall within the technical scope of the present invention. [Explanation of symbols]

[0112] 100 Shovel 1 Undercarriage 2 Upper rotating body 3 Cabin 4. Boom 5 Arm 6 Bucket 8. Diesel Engine 19 Fuel Tank 20. Urea tank 22 Filler 23 Filler cap 28 Adapters 28A Strainer 31 Swivel Frame 42 Lid unit 41 Air breather hose 78 Relay bracket 74a, 25a signal line

Claims

1. An upper rotating body; An engine mounted on the upper rotating body; A revolving frame constituting a part of the upper revolving body; a liquid reducing agent tank mounted on the rotating frame; a filler attached to an upper portion of the liquid reducing agent tank; A first filter provided to cover a first opening at a lower end of the filler; a pipe portion connecting an inside of the liquid reducing agent tank and an inside of the filler so as to release gas in the liquid reducing agent tank when the liquid reducing agent is replenished from the filler to the liquid reducing agent tank; A second filter is provided between the first opening and a second opening at an upper end of the filler, the pipe portion penetrates the liquid reducing agent tank above a lower end of the first opening, The filler has a second through hole for inserting the pipe portion therethrough, The second filter is provided between a second opening present at an upper end of the filler and the second through hole. Shovel.

2. The second through hole is provided in a position facing upward. The shovel according to claim 1.

3. a first lid provided on an upper portion of the liquid reducing agent tank and having a first through hole through which the pipe portion is inserted; the first lid has a connection member for connecting the pipe portion to the first through hole, and supports a signal line of a detection device for acquiring information about the liquid reducing agent inside the liquid reducing agent tank. The shovel according to claim 1.

4. a removable second lid is provided on a second opening at an upper end of the filler; The second lid includes an air breather. The shovel according to claim 1 or 2.

5. The first filter is a fabric inlet filter. A shovel according to any one of claims 1 to 4.

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