Urea tank

Abstract

To provide an urea water tank in which urea water can be prevented from accumulating in a breather pipe disposed in a manner of penetrating through a top surface of a tank main body.SOLUTION: A urea water tank 1 mounted on a work machine comprises: a tank main body 2 including a bottom surface portion 21, a side surface portion 23, and a portion 25; and a breather pipe 5 disposed in a manner of penetrating through the top surface portion 25. A first opening end at one end side of the breather pipe 5 is positioned outside the tank main body 2. A second opening end at the other end side of the breather pipe 5 is positioned in a space formed at an upper side with respect to a maximum liquid level of the urea water stored in an internal space, of the internal space of the tank main body 2. In the case in which the tank main body 2 is in a horizontal state, an upper pipe portion positioned at an upper side of the top surface portion 25 of the breather pipe 5 includes an upper inclined portion extended obliquely upward from a side of the top surface portion 25 and does not include a horizontally extending horizontal region.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a urea water tank mounted on a work machine, and more particularly to a urea water tank provided with a breather pipe. [Background technology]

[0002] Among working machines such as hydraulic excavators and demolition machines, there are models equipped with a urea water tank that stores urea water. For example, in a hydraulic excavator (1) described in Patent Document 1, a urea tank (30) that stores urea water for exhaust gas purification is provided on a deck (41) (FIG. 3 of Patent Document 1).

[0003] The urea water tank is provided with a breather pipe for releasing the internal air to the outside to release pressure. For example, in Patent Document 2, a breather pipe (60) is provided near the lid (51) on the upper surface (42) of the urea water tank (40).

[0004] More specifically, in Patent Document 2, the breather pipe (60) is composed of an upper pipe section (61) that extends vertically while penetrating the upper surface section (42) of the urea water tank (40), and a lower pipe section (62) that is formed integrally with the upper pipe section (61) and has a tip section that penetrates the upper surface section (42) of the urea water tank (40) and extends diagonally downward into the gas phase section (A) (see Figure 4 of Patent Document 2). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2020-007884 A [Patent Document 2] Patent No. 5963270 Summary of the Invention [Problem to be solved by the invention]

[0006] In the above-mentioned Patent Document 2, the lower pipe portion (62) is configured to be as long as possible, thereby preventing the urea water from leaking out of the urea water tank (40).

[0007] However, in order to maintain the ventilation function of the breather pipe (60), it is necessary to separate the open end (62a) of the lower pipe portion (62) from the maximum liquid level (Hmax) of the urea water.

[0008] Therefore, if the lower pipe portion (62) is configured to be long, it becomes necessary to take measures such as lowering the maximum level of the urea water or increasing the height of the urea water tank. However, if the maximum level of the urea water is lowered, the volume of the urea water decreases and the frequency of supplying the urea water increases. Furthermore, if the height of the urea water tank is increased, the manufacturing cost of the urea water tank increases.

[0009] To address this issue, it would be possible to shorten the lower pipe section, but in that case, a new problem would arise in that the urea water would leak out of the urea water tank and adhere to the upper surface of the urea water tank. Therefore, the inventors of the present application came up with a configuration in which the upper pipe section, which extends vertically through the upper surface section of the tank body, is bent sideways and a rubber hose is connected to and routed along the side of the tank body. With this configuration, the urea water that has entered the upper pipe section is discharged to the side of the tank body, preventing the urea water from adhering to the upper surface of the tank body.

[0010] However, when the above-mentioned configuration is adopted, there is a possibility that the urea water that has entered the upper pipe section will accumulate inside the pipe (particularly in the horizontal region toward the side of the tank body). If the urea water accumulates inside the upper pipe section, the accumulated urea water will crystallize and accumulate, causing blockage inside the pipe and inhibiting the ventilation function of the breather pipe.

[0011] Therefore, an object of the present invention is to provide a urea water tank that is capable of preventing urea water from accumulating inside a breather pipe that is provided so as to penetrate the upper surface of the tank body. [Means for solving the problem]

[0012] In order to achieve the above-mentioned object, the present invention provides a urea water tank mounted on a working machine, comprising a tank body including a bottom portion, a side portion and a top portion, and a breather pipe arranged to penetrate the top portion, wherein a first open end on one end of the breather pipe is arranged outside the tank body and a second open end on the other end of the breather pipe is arranged in a space formed within the internal space of the tank body above a maximum liquid level of the urea water stored in the internal space, and when the tank body is in a horizontal state, an upper pipe portion of the breather pipe arranged above the top portion includes an upward inclined portion extending diagonally upward from the side of the top portion.

[0013] Here, it is preferable that the upper pipe portion further includes a vertical portion extending vertically upward from the top surface portion when the tank body is in a horizontal state, and that the upward inclined portion is bent from the upper end of the vertical portion and extends diagonally upward.

[0014] Also, it is preferable that the inclination angle of the upper inclined portion with respect to the horizontal direction is greater than the maximum inclination angle of the work machine.

[0015] It is also preferable that the upper pipe portion further includes a downward inclined portion that is bent from an upper end of the upper inclined portion and extends obliquely downward when the tank body is in a horizontal position.

[0016] It is also preferable that the breather pipe is provided so as to pass through approximately the center of the upper surface portion.

[0017] Furthermore, it is preferable that the lower pipe portion of the breather pipe, which is arranged below the upper surface portion, extends vertically downward from the upper surface portion when the tank body is in a horizontal state, the second opening end opens downward, and a shielding member is arranged between the second opening end and the maximum liquid level when the tank body is in a horizontal state. Effect of the Invention

[0018] According to the present invention, when the tank body is in a horizontal position, the upper pipe portion constituting a part of the breather pipe includes an upwardly inclined portion extending obliquely upward from the side of the upper surface portion of the tank body. Therefore, even if the urea water enters the upper pipe portion, the urea water does not accumulate in the upper pipe portion. Therefore, it is possible to prevent the urea water from accumulating in the tube of the breather pipe. [Brief description of the drawings]

[0019] [Figure 1] FIG. 2 is a perspective view showing the urea water tank according to the embodiment of the present invention. [Diagram 2] FIG. 2 is a view taken along the line II in FIG. [Diagram 3] Cross-sectional view (A) taken along the line AA in FIG. 2 and cross-sectional view (B) taken along the line BB in FIG. [Figure 4] FIG. 4 is a plan view of the lid portion attached to the upper surface of the tank body. [Diagram 5] Cross-sectional view taken along the CC line in Figure 4. [Figure 6] FIG. 4 is a diagram showing the inclination angle of an upper pipe portion of a breather pipe. [Figure 7] FIG. 13 is a perspective view illustrating a shielding plate according to a modified example. [Figure 8] FIG. 4 is a cross-sectional view showing a breather pipe and a shielding plate. [Figure 9] 13A and 13B are diagrams showing a breather pipe according to a modified example (having a different inclination angle of the downward inclined portion). [Figure 10] FIG. 13 is a diagram showing a breather pipe according to a modified example (an example that does not include a downward inclined portion). [Figure 11] FIG. 13 is a diagram showing a breather pipe according to a modified example (an example not including a vertical portion). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] <1. Embodiment> An aqueous urea tank according to an embodiment of the present invention will be described with reference to Fig. 1 to Fig. 6. In the following, an aqueous urea tank 1 shown in Fig. 1 will be illustrated as an example of an aqueous urea tank mounted on a work machine such as a hydraulic excavator, a demolition machine, or a crawler crane.

[0021] As shown in FIG. 1, the urea water tank 1 is configured to include a tank body 2, a lid portion 3 that is detachably attached to an upper surface portion 25 of the tank body 2, a breather pipe 5 that is arranged to penetrate the lid portion 3 vertically, and a rubber hose 6 that is connected to the tip of the breather pipe 5.

[0022] In addition to the above, the urea water tank 1 also includes a water supply port for supplying urea water, a heating pipe for heating the urea water, a urea water suction pipe for sucking in the urea water, etc. The heating pipe and the urea water suction pipe are attached to the lid 3, and therefore can be attached to and detached from the tank body 2 together with the lid 3.

[0023] As shown in FIG. 1, the tank body 2 includes a bottom portion 21, a side portion 23, and an upper portion 25, and is configured as a hollow box-like member.

[0024] 2, the lid portion 3 is configured as a member having a substantially circular shape in a plan view, and is fixed to the upper surface portion 25 with bolts. The lid portion 3 functions as a part of the upper surface portion 25 when attached to the upper surface portion 25.

[0025] As shown in Fig. 5, the breather pipe 5 is provided to penetrate vertically through the cover 3. As described above, the heating pipe, the urea water suction pipe, and the like are also provided to penetrate vertically through the cover 3 (see Figs. 3(A) and (B)).

[0026] The breather pipe 5 is a vent pipe for releasing the air inside the tank body 2 to the outside to release pressure when the urea water is supplied, and is configured by a metal tube in this embodiment. Note that the breather pipe 5 also has a function of maintaining the pressure inside the tank at atmospheric pressure when the urea water stored in the tank body 2 is gradually consumed as the machine operates (injection of the urea water into the exhaust gas) and the liquid level of the urea water drops.

[0027] Specifically, as shown in Fig. 5, the breather pipe 5 is composed of an upper pipe section 5A arranged on the upper side (outside the tank body 2) of the lid section 3, which is a part of the upper surface section 25, and a lower pipe section 5B arranged on the lower side (inside the tank body 2) of the lid section 3. Note that the upper pipe section 5A and the lower pipe section 5B are not separate tubes but are composed of a single continuous tube.

[0028] The upper pipe section 5A is configured to include a vertical section 51, an upwardly inclined section 52, and a downwardly inclined section 53.

[0029] The vertical portion 51 is a portion that extends vertically upward from the lid portion 3 that constitutes part of the upper surface portion 25 when the tank body 2 is in a horizontal state. In this embodiment, when the tank body 2 is in a horizontal state, it means that the work machine on which the urea water tank 1 is mounted is not tilted.

[0030] The upwardly inclined portion 52 is a portion that bends and extends obliquely upward from the upper end of the vertical portion 51 when the tank body 2 is in a horizontal state. Here, the upwardly inclined portion 52 extends to the maximum height allowed in terms of the installation layout.

[0031] Furthermore, the inclination angle of the upward inclination portion 52 with respect to the horizontal direction is set to a value larger than the maximum inclination angle of the work machine on which the urea water tank 1 is mounted. In this embodiment, the maximum inclination angle of the work machine on which the urea water tank 1 is mounted is 35 degrees. Therefore, as shown in Fig. 6, the upward inclination portion 52 is inclined upward by about 45 degrees with respect to the horizontal direction so that the inclination angle of the upward inclination portion 52 with respect to the horizontal direction is larger than the maximum inclination angle of 35 degrees.

[0032] The downward inclined portion 53 is a portion that bends and extends obliquely downward from the upper end of the upper inclined portion 52 when the tank body 2 is in a horizontal state. In this embodiment, as shown in Fig. 6, the downward inclined portion 53 is inclined downward by about 15 degrees with respect to the horizontal direction.

[0033] As described above, the three parts constituting the upper pipe section 5A, namely the vertical section 51, the upward inclined section 52, and the downward inclined section 53, are configured so as not to be horizontal when the tank body 2 is in a horizontal state. In other words, the upper pipe section 5A is configured so as not to include a horizontal region (horizontal section) that extends horizontally when the tank body 2 is in a horizontal state.

[0034] As shown in FIGS. 1 to 3, a rubber hose 6 is connected to the tip of the downward inclined portion 53 and is routed to the side surface portion 23 of the tank body 2.

[0035] Next, a description will be given of the lower pipe section 5B (see FIG. 5) constituting a part of the breather pipe 5. The lower pipe section 5B is disposed in a space above the maximum liquid level of the urea water stored in the internal space of the tank body 2. This space functions as a gas phase section for absorbing expansion caused by a temperature rise or freezing of the urea water.

[0036] When the tank body 2 is in a horizontal state, the lower pipe section 5B extends vertically downward through the lid section 3. The vertical length of the lower pipe section 5B is shorter than the vertical length of the vertical section 51. In other words, in this embodiment, the lower pipe section 5B is configured to be much shorter than the upper pipe section 5A.

[0037] 5, an open end 50A of the upper pipe section 5A (an open end on one end side of the breather pipe 5) is disposed outside the tank body 2. The open end 50A is an example of a first open end according to the present invention.

[0038] As described above, the rubber hose 6 is connected to the open end 50A of the upper pipe portion 5A. As shown in Figures 3(A) and (B) , the rubber hose 6 extends from the open end 50A while inclining downward toward the side surface portion 23, and then extends vertically downward along the side surface portion 23. The tip of the rubber hose 6 opens downward.

[0039] On the other hand, the open end 50B of the lower pipe section 5B (the open end on the other end side of the breather pipe 5) is disposed in a gas phase portion formed in the internal space of the tank body 2, i.e., in a space above the maximum liquid level of the urea water stored in the internal space of the tank body 2. The open end 50B is an example of a second open end according to the present invention. The open end 50B opens downward and faces the liquid level of the urea water stored in the tank body 2.

[0040] According to the above-described embodiment, as shown in FIG. 5, the upper pipe section 5A includes a vertical section 51, an upwardly inclined section 52, and a downwardly inclined section 53, but does not include a horizontal region that extends horizontally when the tank body 2 is in a horizontal state.

[0041] Therefore, even if the urea water enters the upper pipe section 5A and reaches the upper inclined section 52, the urea water does not accumulate at the upper inclined section 52, but flows down into the tank body 2 via the upper inclined section 52 and the vertical section 51. Also, even if the urea water passes through the upper inclined section 52 and reaches the downward inclined section 53, the urea water does not accumulate at the downward inclined section 53, but flows down to the side of the tank body 2 via the downward inclined section 53 and the rubber hose 6.

[0042] Therefore, it is possible to prevent the urea water from staying inside the breather pipe 5. In other words, it is possible to prevent the urea water from staying inside the breather pipe 5, crystallizing, and clogging the inside of the pipe. As a result, it is possible to reliably maintain the ventilation function of the breather pipe 5.

[0043] Furthermore, according to the embodiment described above, the upper pipe section 5A is bent at two locations, the upper end of the vertical section 51 and the upper end of the upwardly inclined section 52. Therefore, compared to a section that is not bent but is configured straight or a section that is bent at only one location, it is possible to hinder the progress of the urea water that has entered the upper pipe section 5A and reduce the amount of urea water that leaks out of the tank body 2.

[0044] Furthermore, according to the embodiment described above, the inclination angle (45 degrees) of the upward inclination portion 52 with respect to the horizontal direction is set to a value greater than the maximum inclination angle (35 degrees) of the work machine on which the urea water tank 1 is mounted. Therefore, even when the work machine is at its maximum inclination, the inclined state of the upward inclination portion 52 is maintained and does not become horizontal. As a result, the urea water that has entered the upward inclination portion 52 does not accumulate, regardless of the inclination of the work machine.

[0045] Also, according to the embodiment described above, the lid portion 3 is attached to approximately the center of the upper surface portion 25 of the tank body 2. Also, the breather pipe 5 is provided so as to penetrate the lid portion 3 in the vertical direction. That is, the breather pipe 5 is provided so as to penetrate approximately the center of the upper surface portion 25 through the lid portion 3. In this regard, when the work machine swings, the liquid level of the urea water is less likely to rise near the center of the tank body 2 compared to the side surfaces of the tank body 2. Therefore, by providing the breather pipe 5 so as to penetrate approximately the center of the upper surface portion 25 through the lid portion 3, it is possible to reduce the amount of urea water that enters the breather pipe 5.

[0046] Furthermore, according to the embodiment described above, as shown in FIG. 5, the lower pipe section 5B is configured to be shorter than the vertical section 51, so there is no need to lower the maximum liquid level of the urea water or increase the height of the urea water tank.

[0047] <2. Modifications> The urea water tank according to the present invention is not limited to the above-described embodiment, and various modifications and improvements are possible within the scope of the claims.

[0048] For example, in the above-described embodiment, the liquid level of the urea water stored in the tank body 2 and the opening end 50B are arranged to face each other, but the present invention is not limited to this. When the tank body 2 is in a horizontal state, the shielding plate 4 (FIGS. 7 and 8) may be arranged between the opening end 50B and the maximum liquid level of the urea water.

[0049] A modified example in which the shielding plate 4 is provided will be described below with reference to FIGS.

[0050] As shown in Fig. 7, a fixing plate 31 for fixing various pipes (heating pipes, urea water suction pipes, etc.) is provided below the lid portion 3. The shielding plate 4 is provided to the fixing plate 31 and extends from the fixing plate 31 toward the lower side of the open end 50B of the lower pipe portion 5B. Then, as shown in Fig. 8, the shielding plate 4 is disposed below the open end 50B with a gap therebetween. The shielding plate 4 is an example of a shielding member according to the present invention.

[0051] According to this modified example, since the shielding plate 4 is provided between the opening end 50B and the liquid surface of the urea water, it becomes difficult for the urea water to enter the breather pipe 5.

[0052] In the above embodiment, the downward inclined portion 53 is inclined downward by about 15 degrees with respect to the horizontal direction as shown in Fig. 6, but is not limited to this. As shown in Fig. 9, the downward inclined portion 53 may be configured to be inclined downward by about 45 degrees with respect to the horizontal direction.

[0053] According to this modified example, the inclination angle (45 degrees) of the downward inclination portion 53 with respect to the horizontal direction becomes greater than the maximum inclination angle (35 degrees) of the work machine on which the urea water tank 1 is mounted. Therefore, the downward inclination portion 53 maintains an inclined state even when the work machine is in the most inclined state. In other words, the downward inclination portion 53 always maintains an inclined state and does not become horizontal. As a result, urea water does not accumulate in the downward inclination portion 53, regardless of the inclination of the work machine.

[0054] Furthermore, even when the work machine is in the most inclined state, the opening end 50A of the downward inclined portion 53 faces downward from the horizontal direction, so that it is possible to prevent blockages in the pipes and the intrusion of debris due to urea water retention without connecting a rubber hose 6 as in the above-described embodiment.

[0055] In addition, in the above-described embodiment, as shown in FIG. 5, an example was given of the upper pipe section 5A being composed of three parts: a vertical section 51, an upwardly inclined section 52, and a downwardly inclined section 53, but this is not limited to this.

[0056] As shown in FIG. 10, the lower inclined portion 53 may be eliminated, and the upper pipe portion 5A may be configured to include two portions, a vertical portion 51 and an upper inclined portion 52.

[0057] 11, the vertical portion 51 may be eliminated, and the upper pipe portion 5A may be configured with two portions, an upper inclined portion 52 and a lower inclined portion 53. Although not shown, the lower inclined portion 53 may be eliminated, and the upper pipe portion 5A may be configured with only the upper inclined portion 52.

[0058] Even if the upper pipe portion 5A shown in FIG. 10 or FIG. 11 is employed, it is possible to prevent the urea water from staying inside the breather pipe 5, as in the above-described embodiment.

[0059] In the above embodiment, the upper inclined portion 52 extends obliquely upward in a straight line, and the lower inclined portion 53 extends obliquely downward in a straight line, but the present invention is not limited to this. One or both of the upper inclined portion 52 and the lower inclined portion 53 may be configured to extend in an arc shape (R-shape).

[0060] In addition, in the above-described embodiment, the breather pipe 5 is formed of a metal tube, but the present invention is not limited to this, and the breather pipe 5 may be formed of a hose such as a resin hose or a rubber hose. [Industrial Applicability]

[0061] INDUSTRIAL APPLICABILITY As described above, the urea water tank according to the present invention is suitable for mounting on a work machine such as a hydraulic excavator or a demolition machine. [Explanation of symbols]

[0062] 1 Urea tank 2 Tank body 3 Lid 4 Shielding Plate 5 Breather pipe 5A Upper pipe section 5B Lower pipe section 6. Rubber hose 21 Bottom part 23 Side part 25 Top part 31 Fixing plate 50A open end 50B open end 51 Vertical section 52 Upward slope 53 Downward slope

Claims

1. A urea water tank mounted on a work machine, a tank body including a bottom portion, a side portion, and a top portion; A breather pipe provided to penetrate the upper surface portion; Equipped with A first open end of the breather pipe is disposed outside the tank body, a second opening end of the breather pipe at the other end side is disposed in a space formed in an internal space of the tank body above a maximum liquid level of the urea water stored in the internal space, a urea water tank characterized in that, when the tank body is in a horizontal state, an upper pipe portion of the breather pipe that is arranged above the upper surface portion includes an upward inclined portion that extends diagonally upward from the side of the upper surface portion, and a downward inclined portion that is bent from an upper end of the upper inclined portion and extends diagonally downward.

2. The upper pipe portion further includes a vertical portion extending vertically upward from the top surface portion when the tank body is in a horizontal state, 2. The urea water tank according to claim 1, wherein the upwardly inclined portion is bent from an upper end of the vertical portion and extends obliquely upward.

3. 3. The urea water tank according to claim 1, wherein an angle of inclination of the upper inclined portion with respect to the horizontal direction is greater than a maximum inclination angle of the work machine.

4. 4. The urea water tank according to claim 1, wherein the breather pipe is provided so as to pass through approximately the center of the upper surface portion.

5. a lower pipe portion of the breather pipe that is disposed below the upper surface portion extends vertically downward from the upper surface portion when the tank body is in a horizontal state; The second opening end opens downward, 5. The urea water tank according to claim 1, wherein a shielding member is disposed between the second opening end and the maximum liquid level when the tank body is in a horizontal position.

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