JP2017227166A - Reductant agent tank system and sub tank applied for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reductant agent tank system capable of storing sufficient amount of urea water and facilitating replenishment work and provide a tank applied for the reductant agent tank system.SOLUTION: This invention relates to a reductant agent tank system 1 for use in supplying liquid reductant agent to a selective catalyst reductant system 2 installed at a vehicle 3 and comprising a main tank 21 connected to a reductant agent supply pipe and fixed to the vehicle to store the reductant agent; a sub-tank 22 that can store the reductant agent and removably arranged at the vehicle; a first connection part 41 arranged at the sub-tank to cause both tanks to be communicated to each other and a first part 31 to be connected that is arranged at the main tank; an opening or closing valve 43 arranged in at least one of the first connection part and the first part to be connected; and a transferring mechanism 55 arranged between the first connecting part and the first part to be connected to transfer the reductant agent stored in the sub-tank when both tanks are communicated to each other and the opening or closing valve is opened.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a reducing agent tank system used in a selective catalytic reduction (SCR) system and a sub-tank used therefor.

There are vehicles equipped with an SCR system that reduces nitrogen oxides (NOx) in exhaust gas. In the SCR system, ammonia (NH ₃ ) is widely used as a NOx reducing agent. A urea aqueous solution (hereinafter referred to as urea water) serving as a precursor as the NH ₃ generation source is loaded on the vehicle. The urea water loaded on the vehicle is injected toward a selective reduction catalyst (hereinafter referred to as SCR catalyst) provided in the exhaust gas flow path. The injected urea water becomes NH ₃ by the catalytic action, and the generated NH ₃ reduces NOx in the exhaust gas to nitrogen.

  In order to load urea water, a urea water tank connected to the SCR system via a urea water supply pipe is mounted on the vehicle. In order to facilitate the supply of urea water to the urea water tank, a urea water tank that can be separated from the SCR system is known (for example, Patent Document 1).

JP 2001-173431 A

  However, since the urea water tank mounted on the vehicle needs to store a sufficient amount of urea water for traveling of the vehicle, the urea water tank after replenishment of the urea water becomes heavy. Therefore, there is a problem that it is difficult to carry the urea water tank and attach it to the SCR system.

  In view of the above background, the present invention has an object to provide a reducing agent tank system that can store a sufficient amount of urea water and that can be easily supplied, and a tank used in the reducing agent tank system. To do.

  In order to solve the above-mentioned problem, there is a reducing agent tank system (1) for supplying a liquid reducing agent to a selective catalyst reduction system (2) mounted on a vehicle (3). A main tank (21) for storing a reducing agent fixed to the vehicle, and a sub-tank (22) that can store the reducing agent and is detachable from the vehicle. ), The first connection part (41) provided in the sub tank and the first connected part (31) provided in the main tank, and the first connection, so that the sub tank and the main tank communicate with each other And an on-off valve provided on at least one of the first connected portion and the first connected portion, and the sub tank and the main tank communicate with each other provided between the first connected portion and the first connected portion. And, when said on-off valve is opened, the reducing agent stored in the sub tank may have a transfer mechanism (55) for transferring to the main tank.

  According to this aspect, it is a tank that supplies the reducing agent to the selective catalyst reduction system, and a sub-tank that is lighter than the entire tank including the main tank and the sub tank and that can be easily replenished is configured.

  In the above aspect, the sub tank may be superposed on the upper side of the main tank.

  According to this aspect, since the reducing agent is transferred from the sub tank to the main tank by gravity, the transfer mechanism is easily configured.

  In the above aspect, the on-off valve (43) having a valve body (44) biased in the closing direction at one of the first connecting portion (41) and the first connected portion (31). When the sub tank (22) is superimposed on the upper side of the main tank (21) on the other of the first connection part and the first connected part, the stop valve is pushed in the opening direction. An adapted operating member (33) may be provided.

  According to this aspect, when the sub tank is superposed on the upper side of the main tank, the reducing agent in the sub tank is supplied to the main tank.

  In the above aspect, the sub tank (22) may be provided with a supply port (46) for supplying a reducing agent.

  According to this aspect, it becomes possible to supply the reducing agent to the sub tank via the supply port.

  In the above aspect, the main tank (21) is provided below the floor (12) of the luggage compartment (11) of the vehicle (3), and the sub tank (22) is provided between the main tank and the floor. It is good that it can be installed between.

  According to this aspect, since the sub tank and the main tank are installed under the floor of the cargo compartment, deterioration of the convenience of the cargo compartment is prevented.

  In the above aspect, the sub tank (22) may be provided with a liquid level gauge (49), and the display (48) of the liquid level gauge may protrude above the floor (12).

  According to this aspect, the amount of urea water in the sub tank is read without accessing the floor.

  In the above aspect, the liquid level gauge (49) may be a float type liquid level gauge.

  According to this aspect, the liquid level gauge of the sub tank is easily configured.

  In the above aspect, the sub tank (22) may be provided with a second connected portion (45) connectable to the first connecting portion (41) provided in the other sub tank.

  According to this aspect, the sub tank superposed on the main tank is further polymerized to increase the total amount of reducing agent that can be stored in the reducing agent tank system.

  Further, a main tank (21) connected to a reducing agent supply pipe (24) leading to the selective catalyst reduction system (1) mounted on the vehicle (3) and supplying a liquid reducing agent to the selective catalyst reduction system, A sub-tank (22) configured to be detachable, wherein the main tank is provided with a first connected portion (31) having an opening (34), and the sub-tank is attached to the main tank. A first connection portion (41) connected to the first connected portion and the first connection portion to communicate the main tank and the sub tank, the main tank and the sub tank An on-off valve (43) for opening and closing communication with the reductant stored in the sub-tank when the first connecting portion is connected to the first connected portion and the on-off valve is open. The main unit Transport mechanism for transporting the click (55) may comprise a.

  According to this aspect, it is possible to configure a tank that facilitates the supply of the reducing agent to the selective catalyst reduction system.

  Further, in the above aspect, the sub tank is mounted on the upper side of the main tank, and has a second connected portion (45) on the upper surface that can be connected to the first connecting portion provided in the other sub tank. Good.

  According to this aspect, since the reducing agent is transferred from the sub tank to the main tank by gravity, the transfer mechanism is easily configured. Further, by loading another subtank on the upper side of the subtank connected to the main tank, the total amount of reducing agent that can be supplied to the selective catalyst reduction system can be increased.

  According to the above configuration, it is possible to provide a reducing agent tank system that can store a sufficient amount of urea water and that can be easily supplied, and a tank used in the reducing agent tank system.

Schematic of urea water supply system according to the present invention (A) sectional view at the time of connection of the main tank and the sub tank according to the present invention, and (B) rear view Sectional view of (A) main tank and (B) sub tank according to the present invention

  Hereinafter, a reducing agent tank system according to an embodiment of the present invention will be described with reference to the drawings.

  As shown in FIG. 1, the reducing agent tank system 1 according to this embodiment is provided in a vehicle 3 on which an SCR system 2 is mounted. The reducing agent described herein is a liquid reducing agent for reducing environmental pollutants in exhaust gas, and includes a liquid containing a reducing agent, a liquid containing a precursor of the reducing agent, or a mixture thereof. Including. In the vehicle 3 described below, the urea SCR system 2 is mounted. The urea SCR system 2 is an SCR system that uses urea water as a reducing agent precursor, and the urea SCR system 2 reduces nitrogen oxides in the exhaust gas to nitrogen.

  The vehicle 3 has an internal combustion engine 4 mounted in an engine room formed at the front thereof, and an exhaust pipe 5 extending to the rear end of the vehicle 3 is connected to the internal combustion engine 4. The exhaust pipe 5 is provided with an oxidation catalyst 6, a urea SCR system 2, a silencer 7, and an exhaust port 8 in order from the front. The oxidation catalyst 6 and the urea SCR system 2 are connected by a pipe, and a urea injector 9 is connected to the upper part of the pipe connected to the front side of the urea SCR system 2. A luggage compartment 11 is provided behind the seat 10 of the vehicle 3, and a tank compartment 14 is provided below the floor 12 of the luggage compartment 11 and above the body frame 13. The reducing agent tank system 1 is accommodated in the tank chamber 14. The reducing agent tank system 1 includes a main tank 21 and a sub tank 22 that can store urea water.

  The main tank 21 is a substantially rectangular parallelepiped tank placed in the tank chamber 14 and can store urea water therein. The main tank 21 is connected to a urea water supply pipe 24 connected to the urea injector 9.

  As shown in FIG. 2, the sub tank 22 can be superposed on the main tank 21 mounted on the vehicle 3 from above. Further, as shown in FIG. 3, the sub tank 22 can be detached from the main tank 21.

  As shown in FIGS. 2 and 3, an inclined surface that slopes downward and downward is formed at the rear of the upper surface of the main tank 21, and the first supply port 25 that opens obliquely upward and backward on the inclined surface. Is provided. The first supply port 25 is defined by a tube port portion protruding from the inclined surface. A male screw is formed on the outer peripheral surface of the tube opening, and the first supply port 25 is closed by a lid body 26 screwed to the tube opening.

  The main tank 21 further includes a first connected portion 31 on its upper surface. The first connected portion 31 is provided on the upper surface of the main tank 21 and has a recessed portion 32 that is recessed downward in a cylindrical shape, and an operation member that protrudes upward from the bottom surface of the recessed portion 32 along the axis of the recessed portion 32. 33 and a recess through hole 34 provided at the bottom of the recess 32. The outside and the inside of the main tank 21 communicate with each other through the recessed through hole 34.

  The main tank 21 further includes a first liquid level gauge 35 that measures the amount of urea water stored in the main tank 21 at the upper front part thereof. The first liquid level gauge 35 includes a first float 36 (float) that floats on the urea water level of the main tank 21 and moves up and down along the height of the urea water level. The first liquid level gauge 35 further includes a sensor 37 that detects the height of the first float 36. The first liquid level gauge 35 detects the amount of urea water in the main tank 21 from the height of the first float 36 detected by the sensor 37, and a signal corresponding to the remaining amount is provided in the driver's seat of the vehicle 3. It transmits to the 1st display part 38 through an electrical wiring. The first display unit 38 displays the remaining amount of urea water in the main tank 21.

  As shown in FIG. 1, the sub-tank 22 is superposed on the upper part of the main tank 21, and is installed under the floor 12 of the cargo compartment 11 and on the main tank 21. That is, the main tank 21 and the sub tank 22 are accommodated in the tank chamber 14. As shown in FIGS. 2 and 3, in this embodiment, the sub tank 22 is a substantially rectangular parallelepiped tank and has a bottom surface that is substantially the same shape as the main tank 21. In the present embodiment, the height of the sub tank 22 is smaller than the main tank 21 and lighter than the main tank 21. The sub-tank 22 has a first connection portion 41 that bulges downward in a columnar shape on the bottom surface. The outer diameter of the first connecting portion 41 is smaller than the inner diameter of the first connected portion 31, and the first connecting portion 41 is formed so as to be able to fit and detach from the first connected portion 31. Inside the bottomed cylindrical first connection portion 41, a discharge port 42 and an on-off valve 43 that opens and closes the discharge port 42 are provided at the bottom of the first connection portion 41. The on-off valve 43 is provided with a valve body 44 that is biased toward the discharge port 42 so as to close the discharge port 42. In the present embodiment, a compression coil spring 44S is provided as means for urging the valve body 44 in the closing direction. In other forms, other springs, urea water pressure, or the like may be used as the biasing means.

  The sub tank 22 includes a second connected portion 45 on the upper surface thereof. The second connected portion 45 has the same shape as the first connected portion 31, and the in-plane position of the second connected portion 45 on the upper surface of the sub tank 22 is the surface on the upper surface of the first connected portion 31 of the main tank 21. It is the same as the inner position. A second replenishing port 46 that opens further upward is provided at the rear of the upper surface of the sub tank 22. In the present embodiment, the shape of the second supply port 46 is substantially the same as that of the first supply port 25, and the second supply port 46 on the upper surface of the sub tank 22 is substantially the same position as the first supply port 25 on the upper surface of the main tank 21. And is closed by the lid 26. The sub tank 22 further includes a handle 47 on its upper surface.

  The sub tank 22 includes a second liquid level gauge 49 that measures the amount of urea water in the sub tank 22. The second liquid level gauge 49 is stored inside the sub tank 22, floats on the urea water level of the sub tank 22, and moves up and down along the height of the urea water level of the sub tank 22. Prepare. The level of the urea water in the sub tank 22 measured by the second liquid level gauge 49 is displayed on the second display unit 48. The second display portion 48 is provided inside the cargo compartment 11 so as to protrude above the floor 12 of the cargo compartment 11. In the present embodiment, the indicator of the second display unit 48 is connected to the second float 50 of the second liquid level gauge 49, and the second display is linked to the height of the second float 50 of the second liquid level gauge 49. The indicator of the part 48 is configured to move up and down.

  When the sub tank 22 is superposed on the main tank 21, the first supply port 25 that is a urea water supply port of the main tank 21 is closed by the lid body 26. The lid body 26 that closes the first supply port 25 is configured such that when the sub tank 22 is superposed on the main tank 21, the lower surface of the sub tank 22 contacts the lid body 26 from above. Therefore, the movement of the lid body 26 in the direction of opening the first supply port 25 is restricted by the housing of the sub tank 22. That is, if the superposition of the sub tank 22 and the main tank 21 is not canceled, the screw connection between the lid body 26 and the tube opening portion of the first supply port 25 is released, and the lid body 26 is removed from the first supply port 25, The first supply port 25 is configured not to be opened.

  Next, operation | movement of the reducing agent tank system 1 which concerns on embodiment of this invention is demonstrated. In the vehicle 3 equipped with the urea SCR system 2, the vehicle 3 can travel when the amount of urea water in the main tank 21 is larger than a predetermined amount of urea water.

  When the amount of urea water in the main tank 21 is smaller than the predetermined amount of urea water, the sub tank 22 filled with urea water is superposed on the upper side of the main tank 21 as shown in FIG. When the sub tank 22 and the main tank 21 are superposed, the first connecting portion 41 is fitted into the first connected portion 31. By fitting the first connecting portion 41 and the first connected portion 31, the valve body 44 of the first connecting portion 41 is pushed up by the operating member 33 provided in the first connected portion 31, and the operating member 33 The on-off valve 43 is opened. When the valve body 44 is pushed up, the discharge port 42 provided in the first connection portion 41 of the sub tank 22 is opened, and urea water is discharged between the main tank 21 and the sub tank 22, and the discharge port 42 and the recess through hole 34. Circulate through.

  When the sub tank 22 and the main tank 21 are superposed, if the lower end of the first connection portion 41 does not reach the urea water level of the main tank 21, urea water is discharged from the first connection portion 41 by gravity, Urea water flows from the sub tank 22 into the main tank 21. By the fitting of the first connecting portion 41 and the first connected portion 31, a transfer mechanism 55 for transferring the urea water in the sub tank 22 to the main tank 21 is formed. Simultaneously with the discharge, air flows into the space above the sub tank 22. When the liquid level reaches the lower end of the connection, air does not flow in even if the liquid level of the sub tank 22 descends, and the space above the sub tank 22 is evacuated. Suction is stopped and discharge stops.

  When urea water is used and there is no urea water in the sub tank 22, the sub tank 22 is filled with urea water. Filling the sub tank 22 with urea water is performed by removing the sub tank 22 from the main tank 21 and injecting urea water into the sub tank 22 from the second supply port 46. When the sub tank 22 is removed from the main tank 21, the valve body 44 is biased toward the discharge port 42, so that the discharge port 42 is sealed by the valve body 44 and the on-off valve 43 is closed. Since the on-off valve 43 is closed, the urea water is stored in the sub tank 22 without leaking. When the sub tank 22 is superposed on the main tank 21, urea water stored in the sub tank 22 is supplied to the main tank 21. After the urea water stored in the sub tank 22 is supplied to the main tank 21, the sub tank 22 may be removed from the main tank 21.

  When the vehicle 3 travels, the urea water stored in the main tank 21 and the sub tank 22 mounted on the vehicle 3 passes through the urea water supply pipe 24 and is sprayed from the urea injector 9 and consumed. When the urea water is consumed, the level of the urea water in the main tank 21 is lowered. The urea water stored in the sub tank 22 flows into the main tank 21 according to the decrease of the urea water in the main tank 21. Since the inflow of urea water is performed until the lower end of the first connection portion 41 reaches the liquid level of the urea water in the main tank 21, the lower end of the first connection portion 41 becomes the liquid level of the urea water in the main tank 21. Thus, urea water is supplied from the sub tank 22 to the main tank 21.

  It is also possible to fill the main tank 21 with urea by directly injecting urea water from the first supply port 25. The filling of the urea water into the sub tank 22 may be performed directly from the second supply port 46.

  Next, the effect of the reducing agent tank system 1 according to the embodiment of the present invention will be described. Since the sub tank 22 is smaller than the main tank 21, the sub tank 22 is lighter than the main tank 21 when filled with urea water. The weight of the sub tank 22 replenished with urea water is smaller than the weight of the main tank 21 replenished with urea water. The sub tank 22 is easily transported and can be easily attached to the main tank 21. . Further, since the sub tank 22 is superposed on the upper side of the main tank 21, it is possible to prevent the remaining amount of urea water in the main tank 21 from becoming zero even though urea water is stored in the sub tank 22. Yes.

  Depending on the injection speed of the urea water into the tank, it may take time to fill the urea water. When quick filling of urea water is required, a sub tank 22 filled with urea water in advance may be attached to the main tank 21. By preparing the sub tank 22 filled with urea water in advance, the urea water can be quickly supplied to the reducing agent tank system 1 when necessary.

  As shown in FIG. 2, a second connected portion 45 is provided on the upper surface of the sub tank 22 in the same manner as the main tank 21. Another sub tank 22 can be superposed on the sub tank 22 connected to the main tank 21 to connect the main tank 21 and the two sub tanks 22. When superposing another sub tank 22 on the sub tank 22, the second liquid level gauge 49 is removed from the sub tank 22, and the inlet of the second liquid level gauge 49 of the sub tank 22 is closed. By superposing the sub tank 22 on the sub tank 22 superposed on the main tank 21, it is possible to increase the amount of urea water that is mounted on the vehicle 3 and can be supplied to the urea SCR system 2.

  When the sub tank 22 is superposed on the main tank 21, the main tank 21 and the sub tank 22 are integrated to supply urea water to the urea SCR system 2. By superposing the sub tank 22 on the main tank 21, the amount of urea water that can be mounted on the vehicle 3 can be increased. When the vehicle travels a distance where there is no possibility of running out of urea water, removing the sub-tank 22 reduces the load weight of the vehicle 3, thereby improving the fuel efficiency of the vehicle 3.

  The amount of urea water in the main tank 21 is measured by the first liquid level gauge 35 and displayed on the first display unit 38 provided in the driver seat provided in the driver seat. It is possible to know deficiency of urea water more quickly. Further, since the amount of urea water in the subtank 22 is displayed on the second display unit 48 in the cargo compartment 11, the user of the vehicle 3 does not open the floor 12 of the cargo compartment 11 and the remaining amount of urea water in the subtank 22. It is possible to know.

  Although the description of the specific embodiment is finished as described above, the present invention is not limited to the above embodiment and can be widely modified. In order to thaw the frozen urea water, the sub tank 22 may be provided with a heater 60 that is a mode for heating the urea water in the sub tank 22. Each of the sub tank 22 and the main tank 21 may be provided with a urea water freezing check mechanism such as a thermometer. When the sub tank 22 for storing the urea water in the liquid state is connected to the main tank 21 having the frozen urea water therein, the urea water in the sub tank 22 is supplied to the main tank 21, and the frozen urea water in the main tank 21 is It becomes possible to rapidly supply the amount of heat required for melting.

  The sub tank 22 may have wheels at the lower part thereof. By providing the sub tank 22 with wheels, the sub tank 22 filled with urea water can be easily transported.

  In this embodiment, urea water is used as the reducing agent, but the reducing agent described in the present specification may be a liquid containing a reducing agent, a liquid containing a reducing agent precursor, or a mixture thereof. For example, a substance other than urea and water may be included for the purpose of lowering the freezing point or coloring.

1: Reductant tank system 2: SCR system (urea SCR system)
3: Vehicle 11: Cargo compartment 12: Floor 21: Main tank 22: Sub tank 24: Urea water supply pipe 31: First connected portion 33: Operation member 34: Recess through hole 41: First connecting portion 43: On-off valve 44 : Valve body 45: Second connected part 46: Second supply port 48: Second display part 49: Second liquid meter 55: Transfer mechanism

Claims (10)

A reducing agent tank system for supplying a liquid reducing agent to a selective catalytic reduction system mounted on a vehicle,
A main tank connected to a reducing agent supply pipe leading to the selective catalyst reduction system and storing a reducing agent fixed to the vehicle;
A sub-tank capable of storing a reducing agent and detachably attached to the vehicle;
A first connecting portion provided in the sub tank and a first connected portion provided in the main tank to communicate the sub tank and the main tank with each other;
An on-off valve provided in at least one of the first connecting portion and the first connected portion;
A reducing agent stored between the first connecting part and the first connected part, wherein the sub tank and the main tank communicate with each other and the on-off valve is open; A reducing agent tank system comprising: a transfer mechanism for transferring to the main tank.   The reducing agent tank system according to claim 1, wherein the sub tank is polymerized on an upper side of the main tank. The on-off valve having a valve body biased in the closing direction is provided on one of the first connection portion and the first connected portion,
An operation member adapted to push the valve body in an opening direction when the sub tank is superposed on the upper side of the main tank is provided on the other of the first connection portion and the first connected portion. The reducing agent tank system according to claim 2, wherein:   4. The reducing agent tank system according to claim 3, wherein a replenishing port for replenishing the reducing agent is provided in the sub tank.   5. The reducing agent according to claim 4, wherein the main tank is provided below a floor of the cargo compartment of the vehicle, and the sub tank is configured to be installed between the main tank and the floor. Tank system.   6. The reducing agent tank system according to claim 5, wherein a liquid level gauge is provided in the sub tank, and a display unit of the liquid level gauge protrudes above the floor.   The reducing agent tank system according to claim 6, wherein the liquid level gauge is a float type liquid level gauge.   The reducing agent tank system according to claim 7, wherein the sub tank is provided with a second connected portion connectable to the first connecting portion provided in the other sub tank. A sub tank connected to a reducing agent supply pipe leading to a selective catalyst reduction system mounted on a vehicle and configured to be detachable from a main tank for supplying a liquid reducing agent to the selective catalyst reduction system;
The main tank is provided with a first connected portion having an opening,
The sub-tank
A first connecting portion connected to the first connected portion to connect the main tank and the sub tank when the main tank is mounted;
An on-off valve provided at the first connection portion for opening and closing the communication between the main tank and the sub tank;
A transfer mechanism that transfers the reducing agent stored in the sub-tank to the main tank when the first connecting portion is connected to the first connected portion and the on-off valve is open. Features a sub tank. Mounted on the upper side of the main tank,
The subtank according to claim 9, further comprising a second connected portion that can be connected to the first connecting portion provided in the other subtank on an upper surface.

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