JP6668882B2 - Additive container - Google Patents

Description

  The present invention relates to an additive container for storing an additive for purifying an engine exhaust gas.

  2. Description of the Related Art Conventionally, there has been known a vehicle equipped with an exhaust gas purification system for reducing and purifying exhaust gas components, which is equipped with an additive tank (additive container) having a reducing action on a substance to be purified. When the substance to be purified is nitrogen oxide (NOx), additives such as an aqueous urea solution and an aqueous ammonia solution are stored inside the tank. Further, it has been proposed that the disposition position of the tank be set, for example, below the floor of the vehicle. With such a layout, a space in the vehicle compartment is ensured, and a decrease in vehicle occupancy due to leakage of the additive is prevented.

  By the way, many frame vehicles such as trucks and buses adopt a layout in which a tank is fixed to a ladder frame which is a frame member of a vehicle body. Since such a tank is relatively easy to access from outside the vehicle, a supply port is provided in the tank itself (see Patent Document 1). Therefore, the user can perform an additive supply operation while visually checking how much additive is stored in the tank.

JP 2010-156284 A

  On the other hand, in a vehicle other than the frame vehicle (for example, a monocoque vehicle or a semi-monocoque vehicle), it is not always possible to arrange the tank at a position that is easily accessible from outside the vehicle. Therefore, it is conceivable to adopt a structure in which a supply port (inlet) is provided on the side of the vehicle or in the passenger compartment, and the supply port and the tank are connected and connected by a supply tube. At this time, since the user cannot visually check the storage amount in the tank, it is conceivable to attach a leveling valve for defining the upper limit liquid level of the additive.

  The leveling valve is a valve body that closes the air passage of the tank when the liquid level reaches a predetermined height, and is disposed slightly below the upper surface of the tank. After the leveling valve is submerged, the pressure in the tank increases as the additive is replenished, and the additive stays inside the replenishing tube. Thereby, the liquid level can be raised to the vicinity of the supply port while maintaining a certain space in the tank. Therefore, the user can visually confirm that the storage amount of the additive has reached the upper limit on the liquid level inside the supply tube.

  However, when the leveling valve is mounted on the wall surface of the tank, the leveling valve may be quickly submerged depending on the inclination of the vehicle body when the additive is replenished, and the amount of the additive stored may be insufficient. Further, when the ventilation path extends from the wall surface or the upper surface of the tank to the center of the tank, and a leveling valve is attached to the end thereof, the structure of the tank is complicated and the protection of the tank may be reduced. Although the strength and rigidity of the ventilation path can be increased, the production cost of the tank rises.

  One of the objects of the present invention has been made in view of the above-mentioned problem, and it is an object of the present invention to provide a highly protective additive container having a simple structure. It is to be noted that the present invention is not limited to this purpose, and is an operation and effect derived from each configuration shown in “Embodiments for Carrying Out the Invention” described later. Can be positioned as an objective.

(1) The additive container disclosed herein is an additive container that stores an additive for purifying engine exhaust and is mounted on a vehicle. The additive container and refill cylinder tube which connects communication between the supply port of the additive is arranged in the vehicle and the additive container, and the atmosphere release valve attached to the upper surface of said additive container, said additive A leveling valve attached to the bottom surface of the concave portion formed on the upper surface of the container and defining an upper limit liquid level of the additive to be supplied from the supply port , one end connected to the leveling valve, and the other end provided for the supply. A leveling pipe connected near a connection point between the cylindrical pipe and the supply port, and closed by the leveling valve when the additive in the additive container reaches or exceeds the upper limit liquid level . In addition, it is preferable that the leveling valve is attached to the inside of the concave portion so that four sides of the leveling valve are surrounded by portions higher than the concave portion.

(2) It is preferable that an expansion portion bulging upward from the upper surface on the side near the exhaust passage of the vehicle is provided. In addition, it is preferable that the height of the expansion part is set at a position higher than the lower end of the atmosphere opening pipe connected to the atmosphere opening valve. Alternatively, it is preferable to set the position higher than the upper end of the atmosphere release valve.
(3) One end is connected to the open-to-air valve, and the other end is provided with an open-to-atmosphere tube that is open to the atmosphere, and a first storage portion that is recessed in a groove shape in the extension portion and stores the open-to-air tube. Is preferred. Since the air release valve always functions, the position at which the other end of the air release pipe is opened can be set arbitrarily. Further, it is preferable that the first storage portion extends along an extending direction of the atmosphere opening pipe.

(4) It is preferable to provide a notch formed by cutting out a front portion on a side far from the exhaust passage of the vehicle. In addition, it is preferable that the cutout portion is an inclined surface provided on one side of the additive container away from the exhaust passage.
(5) It is preferable that pre-SL is recessed in a groove shape on the upper surface and a second housing section for accommodating the leveling tube. Since the leveling valve functions only when replenishing the additive, the position where the other end of the leveling tube is opened may be a position that is opened to the atmosphere when the additive is replenished. preferable.

(6) Preferably, the leveling pipe is arranged below a lower end of a side member of the vehicle.
(7) It is preferable that the leveling pipe is routed with a horizontal or ascending gradient from the leveling valve toward an open end. In other words, it is preferable that the leveling pipe be routed so as not to have an upward slope in all the paths from the open end to the leveling valve.

(8) It is preferable to provide a groove formed in a groove shape from the recess toward the outer edge. It is preferable that the bottom of the groove is formed to be the same as or lower than the recess.
(9) It is preferable that the groove has a bottom with a downward slope from the recess to the outer edge.
(10) Preferably, the groove portion extends in the front-rear direction of the vehicle.

  With a simple configuration, the upper limit liquid level at which the air release valve can function even when the vehicle body is tilted can be set by the leveling valve, and the capacity of the replenished additive can be secured.

1 is a bottom view of a vehicle to which an additive container (tank) according to an embodiment is applied. It is a figure which shows the structure of an additive container typically. FIG. 3 is a perspective view (a downward looking direction) of an additive container. (A)-(C) are partial sectional views of an additive container.

  An additive container as an embodiment will be described with reference to the drawings. Note that the embodiments described below are merely examples, and there is no intention to exclude various modifications and application of technology not explicitly described in the following embodiments. Each configuration of the present embodiment can be variously modified and implemented without departing from the spirit thereof. Further, they can be selected as needed, or can be appropriately combined.

[1. Constitution]
The additive container 10 (hereinafter, simply referred to as a tank 10) of the present embodiment is a liquid additive (eg, an aqueous urea solution, an aqueous ammonia solution, etc.) used in a urea SCR system (Urea Selective Catalytic Reduction System) for purifying exhaust gas. ) Is disposed below the floor of the vehicle 20 shown in FIG. The urea SCR system is a type of exhaust gas purification system for purifying nitrogen oxides (NOx) contained in the exhaust gas of an engine. In the urea SCR system of the present embodiment, an aqueous urea solution is injected upstream of the NOx selective reduction catalyst disposed on the exhaust passage 25, and NOx is formed on the catalyst using ammonia generated by urea hydrolysis as a reducing agent. Is reduced to nitrogen. This type of urea SCR system is widely used in automobiles, work machines, ships, power generation facilities, etc., equipped with a diesel engine or lean burn engine.

  As shown in FIG. 1, a hollow cylindrical side member 21 and a cross member 22 functioning as a frame member are provided on the lower surface side of the floor panel 23 of the vehicle 20. The side members 21 are a pair of structural members arranged at intervals in the vehicle width direction (left-right direction), and extend in the vehicle length direction (front-rear direction) of the vehicle 20. The cross member 22 is a hollow cylindrical structural member connected to the left and right side members 21, and extends in the vehicle width direction of the vehicle 20. The floor panel 23 is a member that is deployed substantially horizontally. The side member 21 and the cross member 22 are formed integrally with the floor panel 23 by, for example, welding and fixing a rail member having a hat-shaped cross section to the lower surface of the floor panel 23.

  As shown in FIG. 1, the shape of the tank 10 is substantially trapezoidal when viewed from the bottom of the vehicle 20, and the upper base is disposed forward and the lower base is disposed rearward. The peripheral portion of the tank 10 is attached to a vehicle body (side member 21, cross member 22, floor panel 23, etc.) via a plurality of brackets 24. Here, the arrangement positions of the respective brackets 24 are set such that the position of the center of gravity of the triangle formed by the three brackets 24 and the position of the center of gravity of the tank 10 are close to each other.

  On the side of the tank 10, an exhaust passage 25 of an engine mounted on the vehicle 20 is routed in the front-rear direction. In the example shown in FIG. 1, a silencer for reducing exhaust noise is arranged adjacent to the right side of the tank 10. These tank 10 and silencer are arranged in the vehicle width direction behind the axle of the rear wheel. In addition, a cover member may be disposed below the tank 10 in order to prevent chipping wear due to hopping stones from the road surface and contamination by muddy water.

  FIG. 2 is a diagram schematically illustrating the structure of the tank 10. The tank 10 is connected to a supply tube 13 for replenishing the additive, and is provided with the atmosphere release valve 2 and the leveling valve 5. The supply tube 13 is a tube that connects the supply port 14 of the vehicle 20 to the tank 10. The supply port 14 of the present embodiment is disposed adjacent to a fuel filler port provided on the left side surface of the vehicle 20. The atmosphere release valve 2 is a vent valve (ventilation valve) for maintaining the internal pressure of the tank 10 near the atmospheric pressure. The atmosphere release valve 2 functions to balance the tank internal pressure and the external pressure while maintaining liquid tightness with respect to additives stored in the tank 10 and external moisture. As shown in FIG. 2, an atmosphere opening pipe 3 is connected to the atmosphere opening valve 2, and the distal end side thereof is opened to the atmosphere via a filter 15. Since the tank 10 is arranged below the floor of the vehicle 20, only the atmosphere opening pipe 3 may be connected to the upper end side of the tank 10 and the atmosphere opening valve 2 may be omitted.

  The leveling valve 5 is a valve body that closes the leveling pipe 6 (ventilation path) of the tank 10 when the liquid level reaches a predetermined height during the replenishment of the additive. Has a function to regulate the liquid level. The leveling pipe 6 is a pipe that opens the tank 10 to the atmosphere via the leveling valve 5 when replenishing the additive. The leveling valve 5 closes the leveling pipe 6 according to the level of the liquid level (for example, when the liquid level becomes equal to or higher than a predetermined level). The air release valve 2 always functions, whereas the leveling valve 5 functions only during the operation of replenishing the additive (for example, during opening of the supply port 14).

  Inside the leveling valve 5, a float member having a small specific gravity capable of floating on the liquid level of the additive is incorporated, and is sealed so as to close the leveling pipe 6 when the liquid level rises. When the liquid level inside the tank 10 rises until the leveling valve 5 is submerged during the replenishment of the additive, the leveling pipe 6 is closed, and the additive stays inside the supply tube 13. Thereby, the user can visually confirm that the storage amount of the additive has reached the upper limit on the liquid level inside the supply tube 13. Note that the float member incorporated in the leveling valve 5 can be omitted. That is, the leveling valve 5 of the present embodiment may not substantially have the float function. Therefore, the end of the leveling pipe 6 on the tank 10 side may be referred to as “leveling valve 5”.

  The distal end (open end 16) of the leveling tube 6 of the present embodiment is connected near the connection point between the supply tube 13 and the supply port 14, as shown in FIG. Further, the position of the leveling valve 5 is set at a position higher than the outlet of the supply tube 13 inside the tank 10. The additive stored in the tank 10 is sucked up by the urea water pump 26 at an appropriate timing according to the operation state of the engine mounted on the vehicle 20 and supplied to the urea water injector 28 through the urea water pipe 27. Is done. The urea water injector 28 is disposed upstream of the NOx selective reduction catalyst interposed on the exhaust passage 25.

  FIG. 3 shows the overall shape of the tank 10 (the positional relationship with the atmosphere release valve 2 and the leveling valve 5). On the upper surface 1 of the tank 10 to which the atmosphere release valve 2 is attached, a concave portion 4 that is concave downward is formed. The shape of the recess 4 is a shape that is recessed in an inverted truncated cone shape. Further, the leveling valve 5 is attached to a bottom surface inside the recess 4. The shape of the concave portion 4 when viewed from above is circular, and is at least as large as the leveling valve 5 can be attached. The depth of the concave portion 4 is set to a depth at which the leveling valve 5 can be disposed below the upper surface 1. Thereby, the periphery of the leveling valve 5 is surrounded by a portion higher than the concave portion 4 (the conical surface of the inverted truncated cone), and the component protection of the leveling valve 5 is improved.

  A groove 9 is formed in a portion of the tank 10 near the outer edge of the recess 4 so as to prevent rainwater or muddy water jumped from the road surface from remaining on the inside of the recess 4. In the present embodiment, the bottom of the groove 9 is formed so as to be at least as high as the bottom of the recess 4, or as shown in FIG. You. However, since it is considered that the amount of rainwater or muddy water entering is small, the groove width and groove depth of the groove portion 9 may be set according to the estimated amount of entering water. By providing the groove 9, drainage from the recess 4 is promoted, and contamination and corrosion of the leveling valve 5 are prevented.

  The extending direction of the groove 9 is set in the front-back direction of the vehicle 20. This makes it easier for the rainwater or muddy water in the recess 4 to be discharged along the groove 9 due to the inertial force accompanying the acceleration and deceleration of the vehicle 20. The shape of the groove 9 may be a tunnel shape instead of the concave shape. In addition, drainage may be improved by providing a slope on the bottom surface of the concave portion 4 to which the leveling valve 5 is attached. In this case, it is preferable that the slope of the bottom surface of the recess 4 be a downward slope toward the groove 9. That is, it is preferable to extend the groove 9 from the lowest position on the bottom surface of the recess 4.

  In the tank 10, on the right side near the exhaust passage 25 behind the vehicle 20, there are provided expansion portions 7 and 8 bulging upward from the upper surface 1. The expansion portions 7 and 8 are portions provided to expand the internal space of the tank 10 and have a function of suppressing submersion of the atmosphere release valve 2 due to the vehicle body tilt. By setting the expansion portions 7 and 8 at positions closer to the exhaust passage 25, the heat receiving area of the tank 10 with respect to the exhaust passage 25 is increased, and an increase in the viscosity and freezing of the additive is suppressed. The height of the extension portions 7 and 8 is set at a position higher than at least the lower end of the atmosphere opening pipe 3, and is preferably set at a position higher than the upper end of the atmosphere opening valve 2. If the extension portions 7 and 8 are made higher than the lower end of the open-to-atmosphere tube 3, the lower end of the open-to-atmosphere tube 3 can be supported by the extension portions 7 and 8. Further, if the extension portions 7 and 8 are made higher than the upper end of the air release valve 2, the component protection of the air release valve 2 is improved.

  Of the expansion parts 7 and 8, the expansion part 8 located immediately behind the atmosphere release valve 2 is provided with a first storage part 11 which is formed in a groove shape so as to surround the peripheral surface of the atmosphere release pipe 3. . As shown in FIG. 4 (B), the inner shape of the first storage portion 11 is formed in such a shape as to come into surface contact with the lower half half cylindrical surface of the cylindrical surface forming the peripheral surface of the atmosphere opening pipe 3. You. In addition, the first storage portion 11 extends along the extending direction (front-back direction) of the open-to-atmosphere tube 3 and functions to support the open-to-atmosphere tube 3 along its longitudinal direction. This stabilizes the mounting state of the atmosphere opening pipe 3 and makes it difficult for repeated loads due to vehicle vibration to act on the connection between the atmosphere opening valve 2 and the atmosphere opening pipe 3. Of the parts is improved.

  Similarly, on the left side of the concave portion 4, there is provided a second storage portion 12 which is formed in a groove shape so as to surround the peripheral surface of the leveling tube 6. As shown in FIG. 4 (C), the inner shape of the second storage portion 12 is formed in a shape that makes surface contact with the lower half half cylindrical surface of the cylindrical surface forming the peripheral surface of the leveling tube 6. . The second storage section 12 extends along the direction in which the leveling tube 6 extends, and functions to support the leveling tube 6 along its longitudinal direction. This stabilizes the mounting state of the leveling pipe 6, and makes it difficult for the repeated load due to the vibration of the vehicle body to act on the connecting portion between the leveling valve 5 and the leveling pipe 6, thereby improving the component protection of the leveling valve 5 and the leveling pipe 6. improves. In addition, similarly to the above-mentioned groove 9, the drainage function from the concave portion 4 may be assigned to the second storage portion 12. In this case, the bottom of the second storage portion 12 may be at the same height as the bottom of the recess 4 or may have a downward slope from the recess 4 toward the outer edge.

  The wiring positions of the leveling tube 6 and the supply tube 13 are set below the lower end of the side member 21 of the vehicle 20. The wiring configuration of the leveling pipe 6 has a gradient that is horizontal or ascends from the leveling valve 5 toward the open end 16. In this embodiment, the leveling pipe 6 extends substantially horizontally from the leveling valve 5 toward the obliquely rear left side, and extends upward after passing under the side member 21. That is, the leveling pipe 6 has a routing shape that does not become an upward slope in all the paths from the open end 16 to the leveling valve 5. The same applies to the supply tube 13, and the route is formed so as not to be ascending in all routes from the supply port 14 to the tank 10. As a result, the remaining of the additive (liquid pool) inside the leveling tube 6 and the supply tube 13 is reliably prevented.

  In the tank 10, a cutout portion 17 is formed in a left portion in front of the vehicle 20 and far from the exhaust passage 25. The surface of the notch 17 is an inclined surface facing diagonally left front of the vehicle 20. By providing the cutout portion 17 on one side far from the exhaust passage 25, the tank volume of the portion of the exhaust passage 25 where heat is difficult to be transmitted is reduced, and the viscosity increase and freezing of the additive are suppressed. Further, by providing an inclined surface on one side away from the exhaust passage 25, the flow path of the outside air heated by the exhaust passage 25 tends to be biased to the left side of the tank 10, and the melting and temperature rise of the additive are promoted. You.

[2. Action, effect]
[1] With a simple configuration in which the leveling valve 5 is disposed inside the concave portion 4 concaved on the upper surface 1 of the tank 10, the upper limit liquid level at which the atmosphere release valve 2 can function regardless of the inclination of the vehicle body. It can be set by the leveling valve 5, and the capacity of the additive can be secured. Further, since the upper surface 1 of the tank 10 has a shape protruding around the leveling valve 5, the internal capacity of the tank 10 can be increased, and the liquid immersion of the atmosphere release valve 2 due to the inclination of the vehicle body can be suppressed. . Further, since it is not necessary to extend the leveling pipe 6 to the inside of the tank 10, it is possible to suppress the occurrence of abnormal noise and the occurrence of fatigue damage due to the vibration of the leveling pipe 6, thereby improving the protection of the tank 10. it can.

[2] By setting the expansion portions 7 and 8 at positions near the exhaust passage 25, it is possible to suppress an increase in the viscosity and freezing of the additive. In addition, by arranging the expansion portions 7 and 8 around the atmosphere opening valve 2, the component protection of the atmosphere opening valve 2 can be improved.
[3] By supporting the open-to-atmosphere tube 3 with the first storage portion 11, the mounting state of the open-to-atmosphere tube 3 can be stabilized, and the protection of the open-to-atmosphere tube 3 can be improved. Further, since each of the air release valve 2 and the air release pipe 3 is fixed and supported to the tank 10, a load acting on a connection portion between the air release valve 2 and the air release pipe 3 can be reduced. . Therefore, it is possible to improve the protection of the parts of the atmosphere opening valve 2 and the atmosphere opening pipe 3.

[4] By providing the notch 17 at the front side far from the exhaust passage 25, the outside air heated by the exhaust passage 25 can be positively circulated to the notch 17, and the viscosity of the additive increases and freezing occurs. Can be suppressed. Therefore, deformation and breakage of the tank 10 due to fixation or freezing of the additive can be prevented, and the protection of the tank 10 can be improved.
[5] By supporting the leveling tube 6 with the second storage section 12, the mounting state of the leveling tube 6 can be stabilized, and the protection of the leveling tube 6 can be improved. Further, since each of the leveling valve 5 and the leveling pipe 6 is fixed to and supported by the tank 10, a load that can act on a connection portion between the leveling valve 5 and the leveling pipe 6 can be reduced. Therefore, the component protection of the leveling valve 5 and the leveling pipe 6 can be improved.

  [6] By laying the leveling tube 6 below the lower end of the side member 21, for example, it is not necessary to move the leveling tube 6 in the vertical direction to avoid the side member 21, thereby increasing the degree of freedom in layout. Can be. Further, since the bent portion in the vertical direction is reduced, it is possible to easily reduce a portion where the stress distribution on the pipe wall of the leveling pipe 6 is excessively concentrated. Therefore, the protection of the leveling tube 6 can be improved.

[7] By setting the wiring configuration of the leveling pipe 6 to a shape that does not become an ascending slope in all the paths from the open end 16 to the leveling valve 5, the residual of the additive (liquid pool) inside the leveling pipe 6 is prevented. can do. Thereby, for example, deterioration of the leveling tube 6 due to deterioration of the residual additive can be prevented. The same applies to the supply tube 13, and the additive can be prevented from remaining inside the supply tube 13.
[8] By providing the groove 9 extending from the recess 4 to the outer edge of the tank 10, it is possible to make it difficult for mud splashing water to collect in the recess 4. Accordingly, the leveling valve 5 can be prevented from being stained or corroded by the mud splashing water, and the protection of the leveling valve 5 can be enhanced.

[9] Further, if the bottom of the groove 9 is formed so as to have the same height as the bottom of the recess 4 or is formed with a downward slope from the recess 4 toward the outer edge, drainage from the recess 4 is improved. Thus, the protection of the leveling valve 5 can be improved.
[10] Further, by setting the extending direction of the groove 9 to the front-back direction of the vehicle 20, the drainage from the recess 4 can be improved by utilizing the inertial force generated by the acceleration and deceleration of the vehicle 20, and the leveling is achieved. The protection of the valve 5 can be further improved.

[3. Modification]
In the above-described embodiment, the tank 10 of the urea SCR system has been described in detail, but the type of the additive stored in the tank 10 is not limited to urea water. In an exhaust gas purification system using a NOx selective reduction catalyst, ammonia may be used instead of urea. Therefore, the above-mentioned tank 10 can be used as an additive container for storing an aqueous ammonia solution. In an exhaust gas purification system that uses a DPF (diesel particulate filter), hydrocarbons (HC, unburned fuel) are injected into the exhaust pipe to promote the combustion of PM (particulate matter). Sometimes. In this case, the above-described tank 10 can be used as an additive container for storing fuel.

DESCRIPTION OF SYMBOLS 1 Top surface 2 Atmosphere release valve 3 Atmosphere release pipe 4 Depression 5 Leveling valve 6 Leveling pipe 7 Expansion part 8 Expansion part 9 Groove part 10 Tank (additive container)
11 first storage section 12 second storage section 13 supply cylinder tube 14 supply port 15 filter 16 open end 17 notch section 20 vehicle 21 side member 22 cross member 23 floor panel 24 bracket 25 exhaust passage 26 urea water pump 27 urea water pipe 28 Urea water injector

Claims (10)

In an additive container mounted on a vehicle, storing an additive that purifies the exhaust of the engine,
A replenishing cylinder that communicates and connects the additive container and a replenishment port of an additive disposed in the vehicle,
An atmosphere release valve attached to the upper surface of the additive container,
A leveling valve attached to the bottom surface of the concave portion formed on the upper surface of the additive container and defining an upper limit liquid level of the additive supplied from the supply port ,
One end is connected to the leveling valve, the other end is connected near the connection point between the supply tube and the supply port, and when the additive in the additive container becomes equal to or higher than the upper limit liquid level. A leveling pipe closed by the leveling valve . An additive container, comprising: 2. The additive container according to claim 1, further comprising an expansion portion bulging upward from the upper surface on a side closer to an exhaust passage of the vehicle. 3. One end connected to the atmosphere release valve, the other end is open to the atmosphere,
The additive container according to claim 2, further comprising a first storage portion that is recessed in a groove shape in the expansion portion and stores the open-to-atmosphere pipe. The additive container according to any one of claims 1 to 3, further comprising a cutout portion formed by cutting out a front portion on a side far from the exhaust passage of the vehicle. 5. The additive container according to claim 1, further comprising: a second storage portion that is recessed in a groove shape on the upper surface and stores the leveling tube. 6. The additive container according to claim 5, wherein the leveling pipe is arranged below a lower end of a side member of the vehicle. 7. The additive container according to claim 5, wherein the leveling pipe is routed from the leveling valve to an open end with a horizontal or ascending gradient. The additive container according to any one of claims 1 to 7, further comprising a groove formed in a groove shape from the recess toward the outer edge. 9. The additive container according to claim 8, wherein the groove has a bottom having a downward slope from the recess toward the outer edge. The additive container according to claim 8, wherein the groove extends in a front-rear direction of the vehicle.

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