tank

Abstract

This tank stores an additive for vehicle exhaust emission control. The tank comprises a pump that is installed on a bottom wall of the tank and that draws in the additive and discharges the additive to outside the tank, and a storage wall that is erected on the bottom wall so as to be spaced apart from a side outer wall of the tank and surrounds the entire periphery of the pump.

Description

[Technical Field]

[0001] The present invention relates to a tank for storing an additive for purifying exhaust gas from a vehicle. [Background technology]

[0002] Conventionally, one method for purifying nitrogen oxides (NOx) in exhaust gas emitted from diesel engines involves hydrolyzing an additive such as urea water (aqueous additive solution) on a catalyst to generate ammonia (NH3), which then selectively reduces and purifies the nitrogen oxides contained in the exhaust gas. Exhaust purification devices with this function are called urea selective catalytic reduction. Vehicles equipped with urea selective catalytic reduction are equipped with a tank for storing the additive.

[0003] The urea tank described in Patent Document 1 includes a urea water pump having an inlet through which urea water flows and an outlet through which the urea water sucked from the inlet is discharged below the urea water tank, and a liquid reservoir wall that is curved circumferentially to surround the urea water pump and stands upright from the bottom wall. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2020-192876 Summary of the Invention [Problem to be solved by the invention]

[0005] In the technology disclosed in Patent Document 1, when the liquid level of the additive in the tank becomes low, the reservoir wall disrupts the fluidity of the additive crossing the reservoir wall, and further generates fluidity along the curved surface of the reservoir wall, thereby creating a fluid state in which the additive is less likely to freeze, even in cold regions. The adoption of this technology has been shown to be effective in preventing the additive from freezing. However, with regard to cold region countermeasures for additives, there is currently a greater demand than ever for technology that can reduce the impact of external temperatures.

[0006] The present invention has been made in view of the above problems, and its object is to provide a tank that is less susceptible to the effects of external temperatures. [Means for solving the problem]

[0007] In order to achieve the above object, the present invention has, for example, the following configuration.

[0008] (1) A tank for storing an additive for purifying exhaust gas from a vehicle, a pump installed on the bottom wall of the tank, which sucks in the additive and discharges it to the outside of the tank; a storage wall that is erected on the bottom wall so as to be spaced apart from the outer side wall of the tank and that surrounds the entire periphery of the pump; A tank equipped with: (2) The storage wall is a first wall portion surrounding the pump; a second wall portion surrounding at least a portion of the first wall portion; and An inner storage section surrounded by the first wall section and an outer storage section surrounded by the first wall section and the second wall section are formed inside the storage wall. (1) The tank described in (1). (3) The storage wall is a first opening connecting the inner reservoir and the outer reservoir; a second opening connecting the outer reservoir with an area outside the outer reservoir; and In a plan view, the first opening and the second opening are arranged so as to be separated by 180° or more in the circumferential direction relative to the center of the inner storage portion. (2) The tank described in (2). (4) The second wall portion has a first opening side portion located on the first opening side and a second opening side portion located on the second opening side, the outer side wall has a side wall portion adjacent to the second opening side portion, the second opening side portion is gradually spaced apart from the side wall portion as it approaches the second opening; (3) The tank described in (3). (5) The outer storage portion has an expanded portion in which a width between the first wall portion and the second wall portion in a plan view is wider than an opening width of the second opening portion in a plan view. A tank as described in (3) or (4). (6) The widened portion is provided in the vicinity of the first opening. (5) The tank described in (5). (7) The tank further includes a sub-wall portion erected on the bottom wall of the tank outside the storage wall, The sub-wall portion is disposed opposite the second opening. A tank described in any one of (3) to (6). (8) The sub-wall portion is connected to the outer surface of the storage wall. (7) The tank described in (7). (9) The second wall portion has a first opening side portion located on the first opening side and a second opening side portion located on the second opening side, the outer side wall has a side wall portion adjacent to the second opening side portion, the sub-chamber wall extends from the outer surface of the storage wall toward the side wall portion of the tank, The auxiliary chamber wall has a bent portion in the middle of its extension so that its tip portion faces the second opening side. (8) The tank described in (8). (10) The second wall portion has a first opening side portion located on the first opening side and a second opening side portion located on the second opening side, the outer side wall has a side wall portion adjacent to the second opening side portion, the sub-wall portion is spaced from the side wall portion of the tank; a third opening is formed between the sub-wall portion and the side wall portion; The second opening and the third opening are offset in the vehicle front-rear direction. A tank according to any one of (7) to (9). (11) The inner reservoir is provided with a heater disposed adjacent to the pump and configured to heat the additive. A tank according to any one of (2) to (10). (12) The tank is elongated and extends in the front-rear direction of the vehicle, the pump and the storage wall surrounding the pump are disposed on one side of the tank in the vehicle front-rear direction; The height of the storage wall on one side in the vehicle front-rear direction is greater than the height of the other side. A tank according to any one of (1) to (11). (13) The tank is elongated and extends in the front-rear direction of the vehicle, the pump and the storage wall surrounding the pump are disposed on one side of the tank in the vehicle front-rear direction; The storage wall has a height on one side in the vehicle front-rear direction greater than a height on the other side, with a portion where the sub-wall portion is connected as a boundary. (8) The tank described in (8). [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a tank that is less susceptible to the effects of external temperatures. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a bottom view of a vehicle to which the tank of the present invention can be applied. [Figure 2] FIG. 2 is an external perspective view of the tank shown in FIG. [Figure 3]FIG. 4 is a bottom view showing the tank mounting structure. [Figure 4] 2 is a plan view showing a tank and its accessories mounted on the vehicle shown in FIG. 1. FIG. [Figure 5] FIG. 1 is a horizontal cross-sectional view of the tank. [Figure 6] FIG. 6 is an enlarged view of the tank of FIG. 5. [Figure 7] FIG. 2 is an enlarged perspective view of a main part inside the tank. [Figure 8] FIG. 8 is a cross-sectional view taken along the line VIII-VIII in FIG. 6. DETAILED DESCRIPTION OF THE INVENTION

[0011] A tank according to one embodiment of the present invention will be described below with reference to the drawings. In the description with reference to the drawings, the vehicle is described as having a longitudinal direction, a lateral direction (vehicle width direction), and an up-down direction as seen from the driver (occupant) of the vehicle. In addition, in each drawing, the vehicle is described as having a longitudinal direction, a lateral direction, and an up-down direction as seen from the driver (occupant) of the vehicle.

[0012] FIG. 1 is a bottom view of a vehicle to which the tank of the present invention can be applied. The vehicle 1 shown in Figure 1 is equipped with a diesel engine and a selective catalytic reduction (SCR) system that uses an additive such as urea to purify the nitrogen oxides in the exhaust gas emitted from the engine. The additive selective catalytic reduction system injects an additive into the exhaust pipe 7 through which the exhaust gas passes, and uses ammonia, which is produced by hydrolysis of the additive, as a reducing agent to reduce the nitrogen oxides to nitrogen on the catalyst and then emit it. This system is applied to vehicles equipped with diesel engines and lean-burn engines where nitrogen oxide emissions are a problem.

[0013] As shown in Figure 1, the body structure of vehicle 1 is a structure in which the body is mounted on a frame that includes side members 2, 2, which are two front and rear frames extending in the fore-and-aft direction of vehicle 1, and cross members 4, which are left and right frames connecting the side members 2, 2 in the width direction (left and right direction) of vehicle 1.

[0014] The side members 2, 2 are located below the floor at least near the rear of the vehicle 1 and are spaced apart in the vehicle width direction. In FIG. 1, only the portions of the side members 2, 2 near at least the rear of the vehicle 1 are shown.

[0015] A floor panel, which forms part of the body, is fixed to the upper surfaces of the side members 2, 2. Note that Fig. 1 shows only one cross member 4 located rearward of the axle (drive shaft) 5 disposed between the left and right rear wheels 3, 3, and the other cross members 4 are not shown.

[0016] In this embodiment, a differential is disposed between the left and right axles 5, 5, and a propeller shaft, a transmission, etc. are connected to the differential in this order from front to front. Also, although the rear wheels 3, 3 shown in the figure are drive wheels, the front wheels may be drive wheels instead of the rear wheels 3, 3.

[0017] An emergency tire wheel 6 (hereinafter referred to as the spare tire 6) is stored under a floor panel near the rear of the vehicle 1. The spare tire 6 is detachably suspended and fixed to the cross member 4 rearward of the axle 5 via predetermined fasteners (for example, bolts and nuts). Note that the spare tire 6 may also be able to be raised and lowered by winding up and down a chain.

[0018] An exhaust pipe 7 extending from the engine is disposed below the floor panel of the vehicle 1. An exhaust purification device 50 consisting of urea selective catalytic reduction, a muffler (silencer) 8, and the like are disposed in the exhaust pipe 7 along the flow direction of the exhaust gas. Here, the exhaust purification device 50 is part of the additive selective catalytic reduction system described above. A nozzle (not shown) for injecting an additive is disposed inside the exhaust pipe 7 (including inside the exhaust purification device 50). The nozzle for injecting the additive is generally disposed upstream of the exhaust purification device 50, but the injection position is selected appropriately depending on the specifications.

[0019] Additionally, a tank 10 that stores a certain amount of additive for purifying exhaust gas of the vehicle 1 is mounted under the floor panel and close to the spare tire 6, in order to supply the additive into the exhaust pipe 7. In the illustrated example, the spare tire 6 is disposed in the center of the vehicle 1 in the left-right direction, and the tank 10 is disposed on the left side, which is outside the spare tire 6 in the left-right direction. The location of the tank 10 is not particularly limited, and the tank 10 may be disposed to the right of the spare tire 6, for example.

[0020] Fig. 2 is an external perspective view of the tank shown in Fig. 1. Fig. 3 is a bottom view showing the mounting structure of the tank. Fig. 4 is a plan view showing the tank and its accessories mounted on the vehicle shown in Fig. 1. Fig. 5 is a horizontal cross-sectional view of the tank. Fig. 6 is an enlarged view of the tank of Fig. 5. Fig. 7 is an enlarged perspective view of the main parts inside the tank.

[0021] As shown in FIG. 4, an additive injection pipe 31, a leveling pipe 32, and a vent pipe 33 are connected to the upper part of the tank 10 (the front side of the paper surface of FIG. 4).

[0022] The additive injection pipe 31 is a pipe member for refilling an additive such as urea water into the tank 10. The additive injection pipe 31 is a passage that is drawn out from an injection port 31c provided in the front wall 12c of the tank 10, for example, and refills the additive from the outside through a supply port 31b of an additive filler 31a provided in an appropriate position on the vehicle 1.

[0023] The leveling pipe 32 is a passage that releases air inside the tank 10 to the additive filler 31a side when the additive is replenished.

[0024] The vent pipe 33 is a passage that releases the gas inside the tank 10 to the atmosphere when the pressure inside the tank 10 increases. An atmosphere release valve that opens and closes the passage is provided midway along the vent pipe 33. The atmosphere release valve opens when the internal pressure of the tank 10 reaches or exceeds a set pressure.

[0025] A signal cable 34 and a power cable 35 for driving the components of the electrical system are connected to the tank 10.

[0026] An additive supply pipe 36 that sends the additive to the exhaust pipe 7 is connected to the lower part of the tank 10 (the rear side of the paper surface of FIG. 4). By the action of a pump 18 described later, the additive is sent from a delivery port 36c (see FIG. 5) provided in the bottom wall 11 of the tank 10 through the additive supply pipe 36 to the exhaust pipe 7.

[0027] The tank 10 may be a molded product made of, for example, a metal with excellent corrosion resistance such as stainless steel, a resin such as polyethylene or polypropylene, or a glass fiber reinforced plastic (FRP), etc. The tank 10 may be formed by integrally molding a plurality of molded members using a known method such as welding, bonding, or fusion.

[0028] A cover (not shown) serving as a protective member is attached to the bottom of the tank 10 so as to cover part or all of the tank 10. This cover protects the tank 10 from impact and preferably has a predetermined level of thermal insulation to prevent excessive temperature changes in the additives.

[0029] As shown in Figure 2, the tank 10 has a hollow structure formed by joining the open sides of a bottomed, concave lower member 10b that opens upward and has a bottom wall 11 and a bottomed, concave upper member 10a that opens downward and has a top wall 13.

[0030] 5 to 7, a recess 11b that is deeper than other portions is formed in the bottom wall 11 of the lower member 10b of the tank 10. In the illustrated example, the recess 11b has a circular cross section, but the shape of the recess 11b is not particularly limited. In the illustrated example, the recess 11b is located on one side in the front-rear direction of the tank 10, which is elongated in the front-rear direction (the rear side in the illustrated example), but the location of the recess 11b is not particularly limited.

[0031] The recess 11b is provided with a pump 18 that sucks in the additive using a driving force such as a motor and discharges it to the outside of the tank 10, and a heater 19 that is disposed adjacent to the pump 18 and heats the additive to an appropriate predetermined temperature. The additive is delivered by the pump 18 from a delivery port 36c provided in the recess 11b through the additive supply pipe 36 (see FIG. 4) to the exhaust pipe 7 side. In addition, a storage wall 20 is provided on the bottom wall 11 so as to surround the recess 11b, the details of which will be described later.

[0032] The tank 10 has outer side walls 12 that define the four sides, front, rear, left, and right, of the tank 10. The outer side walls 12 include an outer wall 12a located on the left-right outer side member 2 side (left side), an arc-shaped inner wall 12b located on the right-left inner side spare tire 6 side (right side), a front wall 12c located on the front side, and a rear wall 12d located on the rear side. The outer wall 12a, inner wall 12b, front wall 12c, and rear wall 12d are connected to each other and close the four sides, front, rear, left, and right, of the tank 10.

[0033] As shown in FIG. 5, the tank 10 includes an extension portion 10d in which the pump 18 and heater 19 are disposed, and a connection portion 10c extending forward from the extension portion 10d to a front wall 12c in which an inlet 31c for an external additive is provided. The extension portion 10d is wider in the left-right direction than the connection portion 10c, forming a large space capable of accommodating the pump 18 and heater 19. The extension portion 10d is formed toward the rear of the tank 10 to facilitate the inflow of additives when the vehicle 1 is tilted uphill. To ensure this large space, the extension portion 10d utilizes a large space on the rear side of the vehicle 1 relative to the center of the spare tire 6, which is circular in plan view (see FIGS. 1 and 4). The center of the spare tire 6 is the center position of the wheel of the spare tire 6.

[0034] The rearward extension 10d of the tank 10 is set to a maximum width L2 in the left-right direction. The maximum width L2 in the left-right direction is also greater than the length L1 in the front-rear direction of the vehicle (L1>L2). Therefore, the tank 10 is elongated and extends in the front-rear direction of the vehicle.

[0035] As shown in Figures 2 to 4, the outer side wall 12 of this tank 10, which is elongated in the front-rear direction, is provided with a plurality of brackets 29 that protrude in the left-right direction of the vehicle. In the illustrated example, three brackets 29 are provided, with one bracket 29 protruding outward in the left-right direction from the rear of the outer wall 12a of the outer side wall 12, and two brackets 29, 29 protruding inward in the left-right direction from the front and rear of the inner wall 12b of the outer side wall 12, respectively. The tank 10 is detachably attached to the underside of the floor panel via the plurality of brackets 29. The brackets 29 are provided with mounting holes 29a through which fastening members such as bolts pass for detachable attachment.

[0036] Of the multiple brackets 29, the left bracket 29 provided on the outer wall 12a is directly fixed to the side member 2 by a bolt or the like inserted into a mounting hole 29a.

[0037] Of the multiple brackets 29, the two right-side brackets 29, 29 provided on the inner wall 12b are attached to the cross member 4 via a first auxiliary frame 41 and a second auxiliary frame 42. The first auxiliary frame 41 and the second auxiliary frame 42 extend in the front-to-rear direction of the vehicle from the cross member 4 above the spare tire 6 (see FIG. 1). The two brackets 29, 29 are fixed to the first auxiliary frame 41 and the second auxiliary frame 42 with bolts or the like inserted into mounting holes 29a, 29a.

[0038] As shown in FIG. 4, the arc-shaped inner wall 12b of the tank 10 is adjacent to the spare tire 6 over almost its entire surface with a small gap between them, and is therefore less susceptible to temperature changes from the outside than the other parts of the side outer wall 12 (the outer wall 12a, the front wall 12c, and the rear wall 12d).

[0039] Furthermore, the tank 10 is disposed to the left of the spare tire 6, and the exhaust pipe 7 is disposed to the right of the spare tire 6. This suppresses the thermal effects of the high-temperature components of the exhaust pipe 7 and the exhaust gas released into the atmosphere, and prevents the temperature of the tank 10 and the additives inside the tank 10 from rising excessively. Note that the openings 9 of the tank 10 and the exhaust pipe 7 may be reversed, so that the tank 10 is disposed to the right of the spare tire 6 and the exhaust pipe 7 is disposed to the left of the spare tire 6.

[0040] As shown in FIGS. 5 to 7, a storage wall 20 is provided on the bottom wall 11 within the expansion section 10d of the tank 10 so as to be spaced apart from the outer side wall 12. The storage wall 20 rises vertically (upward) from the bottom wall 11 outside the recess 11b. The storage wall 20 also surrounds the entire circumference of the pump 18. "Surviving the entire circumference of the pump 18" means that the storage wall 20 is provided over 360° or more in the circumferential direction centered on the pump 18. Therefore, the storage wall 20 has a so-called spiral shape in a plan view.

[0041] In this way, the storage wall 20 is provided so as to surround the entire circumference of the pump 18, which restricts the movement of the additive due to changes in acceleration accompanying acceleration / deceleration or turning of the vehicle 1, and allows the additive to be held inside the storage wall 20. As a result, even when the remaining amount of additive in the tank 10 is low, the additive can be held near the pump 18, and the additive can be reliably flowed into the pump 18. Furthermore, because the storage wall 20 surrounding the pump 18 is provided so as to be spaced apart from the outer side wall 12 of the tank 10, the additive near the pump 18 inside the storage wall 20 is prevented from coming into direct contact with the outer side wall 12 of the tank 10. This reduces the effect of the temperature outside the tank 10 on the additive near the pump 18.

[0042] In the illustrated example, the recess 11b is provided with a heater 19 disposed adjacent to the pump 18. Therefore, the storage wall 20 surrounds not only the pump 18 but also the entire periphery of the heater 19.

[0043] The storage wall 20 has a first wall portion 21 that is disposed outside the pump 18 and the heater 19 and surrounds the pump 18 and the heater 19, and a second wall portion 22 that is disposed outside the first wall portion 21 and surrounds at least a portion of the first wall portion 21. Then, inside the storage wall 20, an inner storage portion 23 that is surrounded by the first wall portion 21, and an outer storage portion 24 that is surrounded by the first wall portion 21 and the second wall portion 22 are formed.

[0044] In this way, an inner reservoir portion 23 surrounded by the first wall portion 21 and an outer reservoir portion 24 surrounded by the first wall portion 21 and the second wall portion 22 are formed inside the reservoir wall 20, so that a plurality of reservoir regions for the additive are provided. This makes it possible to suppress the movement of the additive away from the pump 18. As a result, it is possible to enhance the effect of retaining the additive near the pump 18. Furthermore, since a double-walled portion is provided in which the first wall portion 21 and the second wall portion 22 are spaced a predetermined distance apart, the heat-shielding effect of the storage wall 20 can be enhanced. This makes it possible to more effectively reduce the influence of the external temperature on the tank 10.

[0045] In the inner reservoir 23, not only the pump 18 but also the heater 19 that is disposed adjacent to the pump 18 and heats the additive is provided. Therefore, the additive flowing into the pump 18 can be more reliably prevented from freezing.

[0046] The first wall portion 21 and the second wall portion 22 form a continuous spiral shape on the vehicle front side and left side of the storage wall 20. The storage wall 20 is provided near the continuous portion between the first wall portion 21 and the second wall portion 22, and has a first opening 21h connecting the inner storage portion 23 and the outer storage portion 24, and a second opening 22h connecting the outer storage portion 24 and an area outside the outer storage portion 24 (an auxiliary chamber 30 described below).

[0047] 6, an inner starting end 21a of the first wall portion 21, which is the inner starting end of the spiral shape of the storage wall 20, is located in front of and to the left of the pump 18 and the heater 19. The first wall portion 21 extends in an arc shape from the starting end 21a so as to surround the pump 18 and the heater 19. A terminal end 21b of the first wall portion 21 is disposed in front of the starting end 21a via a gap, and a first opening 21h is provided between the terminal end 21b and the starting end 21a.

[0048] The second wall portion 22 has a first opening side portion 221 located on the side of the first opening 21h, and a second opening side portion 222 located on the side of the second opening 22h.

[0049] The first opening side portion 221 has an L-shaped cross section, and includes a left-right extending portion 221a that connects to the end 21b of the first wall portion 21 and extends to the left, and a front-rear extending portion 221b that extends rearward from the left end of the left-right extending portion 221a. The front-rear extending portion 221b is provided substantially parallel to the outer wall 12a of the side outer wall 12 at a predetermined distance.

[0050] The second opening-side portion 222 is a portion that is connected to the rear end of the first opening-side portion 221 and extends in the left-right direction behind the first wall portion 21. The rear wall 12d of the side outer wall 12 is a side wall portion that is close to the second opening-side portion 222. From the left end of the second opening-side portion 222 to near the center in the left-right direction, it is provided approximately parallel to the rear wall 12d of the side outer wall 12 at a predetermined distance, but from near the center in the left-right direction toward the right, that is, as it approaches the second opening 22h, it curves forward so as to gradually move away from the rear wall 12d.

[0051] By configuring the second wall portion 22 in this manner, it is possible to efficiently utilize the space inside the tank 10. Furthermore, since the second opening 22h can be disposed so as to be spaced apart from the rear side wall 12d, it is possible to reduce the effect of the temperature outside the tank on the additive flowing in through the second opening 22h.

[0052] Furthermore, an end 222a of the second opening side portion 222 of the second wall portion 22, which is the outer end of the spiral shape of the storage wall 20, is located rearward and to the right of the pump 18 and the heater 19. A second opening 22h is formed between this end 222a and the first wall portion 21. The second opening 22h connects the outer storage portion 24 with the auxiliary chamber 30, which is an area outside the outer storage portion 24.

[0053] As shown in FIG. 6, the first opening 21h and the second opening 22h are arranged so as to be separated by 180° or more in the circumferential direction with respect to the center C of the inner reservoir 23 in a plan view.

[0054] In this way, the first opening 21h and the second opening 22h are arranged so as to be separated by 180° or more in the circumferential direction relative to the center C of the inner reservoir 23 in a plan view, so that the outer reservoir 24 can be provided with a curved shape that is long in the circumferential direction and is 180° or more. This improves the ability of the outer reservoir 24 to retain the additive. Furthermore, since the double-layered portion of the first wall 21 and the second wall 22 is long, the influence of the external temperature on the tank 10 can be reduced.

[0055] Here, heat is transferred by heater 19 in the following order: additive in inner reservoir 23, additive in first opening 21h, additive in outer reservoir 24, and additive in second opening 22h. Therefore, the greater the separation angle between first opening 21h and second opening 22h is set beyond 180°, the greater the additive retention capacity of outer reservoir 24 and the effect of reducing the influence of external temperature due to the doubling of reservoir wall 20. However, it becomes more difficult for heater 19 to heat the additive in outer reservoir 24 and second opening 22h, and there is a risk that the additive may freeze in these locations in a cold climate environment. Therefore, from the viewpoint of achieving both the additive retention capacity of outer reservoir 24, the reduction in the influence of external temperature due to the doubling of reservoir wall 20, and the prevention of freezing of additive in outer reservoir 24 and second opening 22h, it is preferable that first opening 21h and second opening 22h be 180° or more and 360° or less in the circumferential direction about center C of inner reservoir 23 in plan view. Note that in the example of Fig. 6, first opening 21h and second opening 22h are arranged so as to be exactly 180° apart in the circumferential direction about center C of inner reservoir 23 in plan view.

[0056] Furthermore, outer reservoir 24 has front widened portion 25 and rear widened portion 26 in which widths L4, L5 between first wall 21 and second wall 22 in a plan view are wider than opening width L3 of second opening 22h in a plan view. In the illustrated example, widths L4, L5 of front widened portion 25 and rear widened portion 26 are wider than opening width L3 of second opening 22h and also wider than the opening width of first opening 21h.

[0057] The front widened portion 25 is located at a corner on the front left side of the storage wall 20. That is, the front widened portion 25 is located closer to the first opening 21h than to the second opening 22h. More specifically, the front widened portion 25 is formed between the first wall 21 and a corner where the left-right extending portion 221a and the front-rear extending portion 221b of the first opening side portion 221 of the second wall 22 are connected.

[0058] Moreover, the rear widened portion 26 is located at a corner on the rear side and left side of the storage wall 20. That is, the rear widened portion 26 is located approximately midway between the first opening 21h and the second opening 22h. More specifically, the rear widened portion 26 is formed between the first wall 21 and a corner where the front-rear direction extending portion 221b of the first opening-side portion 221 of the second wall 22 and the second opening-side portion 222 are connected.

[0059] In this way, the outer reservoir 24 has the wide front widened portion 25 and the wide rear widened portion 26, so that a larger amount of additive can be stored in the outer reservoir 24.

[0060] Furthermore, the front widened portion 25 is provided near the first opening 21h. By providing the front widened portion 25 at a location close to the first opening 21h in this manner, the amount of additive stored in the region of the outer storage portion 24 close to the inner storage portion 23 can be increased. Here, when the frozen additive is thawed, the additive is thawed in order from the portion closest to the first opening 21h. Therefore, by providing the front widened portion 25 at a location close to the first opening 21h, the thawing of the additive can be more efficiently promoted.

[0061] The tank 10 further has a sub-wall portion 28 standing on the bottom wall 11 of the tank 10 outside the storage wall 20. The sub-wall portion 28 stands vertically (upward) from the bottom wall 11. The sub-wall portion 28 is disposed so as to face the second opening 22h. In other words, the sub-wall portion 28 is located on an extension of the second opening 22h in the opening direction.

[0062] By arranging the sub-wall portion 28 opposite the second opening 22h in this manner, a storage area, which can also be called a sub-chamber 30, in which additives can be secondarily stored can be formed in the opposing area between the sub-wall portion 28 and the second opening 22h on the outside of the storage wall 20.

[0063] Although the sub-wall portion 28 does not necessarily have to be connected to the outer surface of the storage wall 20, the base 28a of the sub-wall portion 28 in this embodiment is connected to the outer surface of the storage wall 20. In the example shown, the base 28a of the sub-wall portion 28 is connected to the right side and near the center in the front-to-rear direction of the outer surface of the arc-shaped first wall portion 21. Therefore, the front of the sub-chamber 30 formed by the sub-wall portion 28 and the second opening 22h is closed, so that the additive can be stored in the sub-chamber 30 more reliably.

[0064] The sub-wall portion 28 extends from the outer surface of the storage wall 20 toward the rear wall 12d (side wall portion) of the tank 10. Furthermore, the sub-wall portion 28 has a bent portion 28c midway along its extension such that its tip portion 28b faces the second opening 22h (left side). More specifically, the sub-wall portion 28 has a base portion 28a connected to the outer surface 20a of the storage wall 20, an inclined portion 28d that slopes to the right as it extends rearward from the base portion 28a, a bent portion 28c that is the tip of the inclined portion 28d, an extending portion 28e that extends rearward from the bent portion 28c, and a tip portion 28b that is the tip of the extending portion 28e. The inclined portion 28d extends at an angle of approximately 45° in the left-right direction relative to the front-rear direction, and the extending portion 28e extends approximately parallel to the front-rear direction.

[0065] In this way, the sub-wall portion 28 has a bent portion 28c that is bent midway through its extension so that its tip portion 28b faces the second opening 22h, thereby more reliably storing the additive in the sub-chamber 30, which is the area surrounded by the storage wall 20 and the sub-wall portion 28.

[0066] The tip end 28b of the sub-wall portion 28 is spaced apart from the rear wall 12d (side wall portion) of the tank 10. A third opening 28h is formed between the tip end 28b of the sub-wall portion 28 and the rear wall 12d (side wall portion).

[0067] The second opening 22h and the third opening 28h are offset in the front-to-rear direction of the vehicle 1. In the example of Fig. 6, the length of the extension portion 28e is set so that the tip end 28b of the sub-wall portion 28 is located rearward of the second opening 22h. As a result, the third opening 28h is offset rearward from the second opening 22h.

[0068] In this way, by offsetting the second opening 22h and the third opening 28h in the longitudinal direction of the vehicle 1, direct, linear flow of the additive between the second opening 22h and the third opening 28h is suppressed, the auxiliary chamber 30 can be effectively used as a storage area, and the additive can be stored more reliably.

[0069] As described above, the tank 10 is configured in an elongated shape (L1>L2) extending in the fore-and-aft direction of the vehicle 1. When the tank 10 is long in the fore-and-aft direction of the vehicle in this way, uneven distribution of additives may occur due to movement in the fore-and-aft direction when the vehicle 1 accelerates or decelerates or travels on an incline. However, the pump 18 and the storage wall 20 surrounding it are provided on one side of the tank 10 in the fore-and-aft direction of the vehicle (the rear side in this embodiment), which makes it easy to store unevenly distributed additives.

[0070] Fig. 8 is a cross-sectional view taken along line VIII-VIII in Fig. 6. As shown in Fig. 8, the storage wall 20 is formed so that a height H2 on one side (rear side) in the vehicle longitudinal direction is greater than a height H1 on the other side (front side) (H2>H1).

[0071] More specifically, referring also to Figure 6, of the storage wall 20, (i) the portion of the first wall portion 21 from the starting end 21a to the point where the base 28a of the sub-wall portion 28 is connected, and (ii) the portion of the second wall portion 22 including the front-to-rear extending portion 221b of the first opening side portion 221 and the second opening side portion 222 are set to a relatively low, constant height H1.

[0072] On the other hand, the height H2 of (i) the portion of the first wall portion 21 from the point where the base 28a of the sub-wall portion 28 is connected to the terminal end 21b of the storage wall 20 and (ii) the left-right extending portion 221a of the first opening-side portion 221 of the second wall portion 22 is set higher than the height H1 (H2>H1). In particular, (i) the portion of the first wall portion 21 from the point where the base 28a of the sub-wall portion 28 is connected to the terminal end 21b of the storage wall 20 is inclined upward so that the height H2 gradually increases toward the front, and the height H2 reaches a maximum value H2max near the front end. Also, (ii) the height H2 of the left-right extending portion 221a of the first opening-side portion 221 of the second wall portion 22 is the maximum value H2max.

[0073] In this way, the height H2 of the other side (front side) of the storage wall 20 is set to be higher than the height H2 of one side (rear side), with the part of the storage wall 20 where the base 28a of the sub-wall portion 28 is connected as the boundary.

[0074] In this way, the storage wall 20 is formed with a higher height H2 on the other side (front side) opposite to the side (rear side) on which the storage wall 20 and the pump 18 are provided, so that the additive can be retained within the storage wall 20 even when the vehicle 1 is accelerating or decelerating or when driving on an incline. Furthermore, since the storage wall 20 has high and low portions, when an additive is injected into the tank 10 from the outside via the additive injection pipe 31 (see FIG. 4), the additive can be smoothly supplied into the storage wall 20 by climbing over the low height H1 portion of the storage wall 20. On the other hand, if the entire storage wall 20 were made high, it would be difficult to supply the additive into the storage wall 20 by climbing over the top of the storage wall 20, and the additive would have to pass through the route of the third opening 28h → sub-chamber 30 → second opening 22h → outer storage section 24 → first opening 21h → inner storage section 23, which is not preferable.

[0075] Furthermore, the boundary where the height of storage wall 20 changes is the portion where base 28a of sub-wall portion 28 is connected. This allows a portion of the additive stored in sub-chamber 30 to be supplied directly to inner storage portion 23 from first wall portion 21, which has a reduced height, thereby shortening the time required to supply the additive.

[0076] Although the embodiments of the present invention have been described above, the present invention can be modified as appropriate within the scope of its technical concept. For example, in the above embodiment, the storage wall 20 is provided in a spiral shape, but this is not limited to this shape. Also, in the above embodiment, the storage wall 20 is provided in a substantially circular shape, but this is not limited to this and may be, for example, an elliptical shape, a polygonal shape, or the like. Also, in the above embodiment, the auxiliary wall portion 28 is provided with a bent portion 28c, but this is not limited to this and the auxiliary wall portion 28 may be provided in a linear shape or a curved shape without the bent portion 28c. [Explanation of symbols]

[0077] 1 vehicle 2 side members 3 rear wheels 5 axles 4 cross members 6 Tire Wheel (Spare Tire) 7 exhaust pipe 8 Muffler 10 Tank 10a Upper member 10b Lower member 10c Connection 10d extension 11 Bottom wall 11b Recess 12 Side exterior wall 12a Outside wall 12b Medial wall 12c Front wall 12d Rear wall (side wall part) 13 Ceiling wall 18 Pump 19 Heater 20 Retention Wall 21 1st wall section 21a Starting point 21b Termination 21d Rear wall (first outer side wall) 21h 1st opening 22 Second wall section 22h 2nd opening 221 First opening side part 221a Lateral extension part 221b Anteroposterior extension part 222 Second opening side part 222a termination 23 Inner reservoir 24 Outer reservoir 25 Front widening section (widening section) 26 Rear widening section (widening section) 28 Sub-wall section 28a base 28b Tip 28c bend part 28d Slope 28e Extension 28h 3rd opening 29 Bracket 29a Mounting hole 30 Antechamber 31 Additive injection pipe 31a Additive Filler 31b Inlet 31c inlet 32 Leveling pipe 33 Vent pipe 36 Additive supply pipe 36c Outlet 41 First auxiliary frame 42 Second auxiliary frame 50 Exhaust gas purification device C center H1, H2 height

Claims

1. A tank for storing an additive for purifying exhaust gas from a vehicle, a pump installed on the bottom wall of the tank, which sucks in the additive and discharges it to the outside of the tank; a storage wall that is erected on the bottom wall so as to be spaced apart from the outer side wall of the tank and that surrounds the entire periphery of the pump; Equipped with The storage wall is a first wall portion surrounding the pump; a second wall portion surrounding at least a portion of the first wall portion; and An inner storage portion surrounded by the first wall portion and an outer storage portion surrounded by the first wall portion and the second wall portion are formed inside the storage wall. tank.

2. The storage wall is a first opening connecting the inner reservoir and the outer reservoir; a second opening connecting the outer reservoir with an area outside the outer reservoir; and The first opening and the second opening are arranged opposite to each other across the center of the inner storage portion in a plan view. The tank of claim 1.

3. the second wall portion has a first opening side portion located on the first opening side and a second opening side portion located on the second opening side, the outer side wall has a side wall portion adjacent to the second opening side portion, the second opening side portion is gradually spaced apart from the side wall portion as it approaches the second opening; 3. The tank of claim 2.

4. The outer storage portion has an expanded portion in which a width between the first wall portion and the second wall portion in a plan view is wider than an opening width of the second opening portion in a plan view.

3. The tank of claim 2.

5. The widened portion is provided in the vicinity of the first opening.

5. The tank of claim 4.

6. The tank further includes a sub-wall portion extending from the bottom wall of the tank outside the storage wall, The sub-wall portion is disposed opposite the second opening.

3. The tank of claim 2.

7. The secondary wall portion is connected to the outer surface of the reservoir wall.

7. The tank of claim 6.

8. the second wall portion has a first opening side portion located on the first opening side and a second opening side portion located on the second opening side, the outer side wall has a side wall portion adjacent to the second opening side portion, The secondary wall extends from the outer surface of the reservoir wall toward the side wall of the tank.

8. The tank of claim 7.

9. The auxiliary wall portion has a bent portion in the middle of its extension, and the portion on the tip side of the bent portion extends at an incline toward the side wall portion relative to the portion on the opposite side of the bent portion from the tip side.

9. The tank of claim 8.

10. the second wall portion has a first opening side portion located on the first opening side and a second opening side portion located on the second opening side, the outer side wall has a side wall portion adjacent to the second opening side portion, the sub-wall portion is spaced from the side wall portion of the tank; a third opening is formed between the sub-wall portion and the side wall portion; The tank according to claim 6, wherein the second opening and the third opening are offset from each other in the vehicle longitudinal direction.

11. The internal reservoir is provided with a heater disposed adjacent to the pump and configured to heat the additive. The tank of claim 1.

12. The tank has an elongated shape extending in the front-rear direction of the vehicle, the pump and the storage wall surrounding the pump are disposed on one side of the tank in the vehicle front-rear direction; The tank according to claim 1 , wherein the height of the one side of the storage wall in the vehicle longitudinal direction is greater than the height of the other side.

13. The tank has an elongated shape extending in the front-rear direction of the vehicle, the pump and the storage wall surrounding the pump are disposed on one side of the tank in the vehicle front-rear direction; The storage wall has a height on one side in the vehicle front-rear direction greater than a height on the other side, with a portion where the sub-wall portion is connected as a boundary.

8. The tank of claim 7.

Images