Reducing agent container of a motor vehicle

Abstract

Reducing agent tank of a motor vehicle comprising a first tank part (1) in the base (B) of which a heating device (5) and an element (5) for extracting reducing agent from the tank are provided, and a second tank part (2) which has at least one wall (3) common to the first tank part (1) in which at least one overflow opening (7) between the first and the second tank part (1, 2) is arranged or designed such that at a certain fill level (L) in the first tank part (1), which in turn may be subdivided by a partition (4), no reducing agent can enter the second tank part (2) from this or any other overflow opening (7) during regular operation of the vehicle, characterized in that the at least one overflow opening (7) is designed such that at a fill level (L) in the second tank part (2),which, when the vehicle is stationary horizontally, lies below this overflow opening (7) when viewed vertically, caused by longitudinal or lateral acceleration of the moving vehicle, reducing agent from the second container part (2) can enter the first container part (1) via this overflow opening (7), and that , (a) in the second container part (2) a ramp (8) leading from its bottom area (B) to the said overflow opening (7) is provided, and / or (b) in the first part of the container (1) below said overflow opening (7) a backflow prevention structure (9) projecting from the wall (3) having this overflow opening (7) is provided.

Description

[0001] The invention relates to a reducing agent container for a motor vehicle, comprising a first container part in the base of which a heating device and an element for extracting reducing agent from the container are provided, and a second container part which has at least one wall common to the first container part, in which at least one overflow opening between the first and the second container part is arranged or configured such that, at a certain fill level in the first container part, which may itself be subdivided by a partition, no reducing agent can enter the second container part from the first container part via this or any other overflow opening during normal operation of the vehicle. For the prior art, reference is made to German patent applications DE 10 2007 015 395 A1, EP 2 076 660 B1, DE 10 2009 047 637 A1, DE 10 2008 062 673 A1 and DE 10 2009 029 247 A1.

[0002] Reducing agent containers for storing a reducing agent intended for the exhaust aftertreatment of combustion engine-powered vehicles (e.g., "AdBlue") are known in numerous embodiments; in particular, various measures are also known by which accelerated electrical thawing of a reducing agent frozen in the container due to low ambient temperatures is enabled. Essentially, this measure consists of thawing only a relatively small (frozen) partial volume, which is separate from the rest of the stored (and frozen) reducing agent. In the simplest case, two separate containers are provided, connected to each other via a hose.

[0003] For reasons of installation space and assembly, the aim is to have only a single reducing agent tank on a motor vehicle. This tank must then be relatively low-profile in height and, due to the required storage volume (viewed horizontally within the vehicle), relatively large in area. Within this single tank, a sub-volume is provided, separated from the rest of the tank volume by a partition or similar structure. This sub-volume contains not only the heating device but also, sensibly, a dispensing device for pumping the reducing agent from the tank to the point of use. This dispensing element can be a pump with an attached discharge line, or alternatively, a suction line for a reducing agent pump located elsewhere.

[0004] The aim here is to demonstrate how the volume of reducing agent contained in the entire reduction container, which is divided into different container parts by means of a partition wall, can be utilized as fully as possible, especially when it only represents a small subset of the container's capacity, i.e., how it can be made available to the element for the removal of reducing agent in a simple manner despite said partition wall (= object of the present invention).

[0005] The solution to this problem for a reducing agent container according to the preamble of claim 1 is characterized in that the at least one overflow opening is designed such that, when the fill level in the second container part is below this overflow opening when the vehicle is stationary horizontally, reducing agent from the second container part can flow into the first container part via this overflow opening due to longitudinal or lateral acceleration of the moving vehicle. Advantageous embodiments and further developments are the subject of the dependent claims.

[0006] According to the invention, a defined separation between two container parts is provided in the form of a common wall. Furthermore, it is ensured that reducing agent located in the second container part, which contains neither the reducing agent extraction element nor the heating device, can pass into the first container part, where the extraction element and the heating device are located, without the need for complex measures. This transfer of reducing agent from the second container part to the first container part initially occurs, i.e., as long as a relatively large amount of reducing agent remains in the reducing agent container, according to the principle of communicating vessels via the aforementioned overflow opening, specifically as long as the fill level in the reducing agent container, viewed in the direction of gravity, is above this overflow opening.However, if the fill level in the reducing agent container has dropped below the lowest overflow opening (i.e., the one closest to the bottom of the container in the vertical direction, i.e., the direction of gravity) due to the removal of reducing agent from the first container section, and through which reducing agent can flow from the second container section into the first, then, according to the invention, reducing agent can continue to flow from the second container section into the first container section via this overflow opening, which is appropriately designed for this purpose. This occurs because impulses acting on the reducing agent from longitudinal or lateral acceleration processes of the vehicle are used to promote this flow of the reducing agent. Longitudinal vehicle acceleration results from increasing or decreasing vehicle speed, while vehicle...Lateral accelerations are the result of a vehicle cornering.

[0007] Preferably, a ramp leading from the bottom of the second container section to the aforementioned overflow opening is provided for this purpose. Reducing agent from the bottom of the second container section can flow up this ramp, which rises towards the overflow opening, and through it into the first container section under the influence of longitudinal or lateral acceleration of the vehicle. Preferably, this ramp is designed and arranged in such a way that both purely longitudinal acceleration processes, and in particular negative vehicle accelerations (i.e., a deceleration that is usually more intense than positive acceleration), and purely lateral acceleration processes can act in this manner. Thus, viewed in the longitudinal direction of the vehicle, the ramp extends forward in the direction of travel with its outlet towards the overflow opening and, in its inlet area, i.e., near the bottom of the container section, faces the vehicle.-Extending in the transverse direction and already featuring slightly rising approach sections, which lead into a ramp section extending in the longitudinal direction of the vehicle, where lateral boundary walls may be provided or which may be designed in a channel-like manner. When projected in the vertical direction, this ramp can therefore be approximately T-shaped, with the crossbar of this letter "T" forming the aforementioned transversely oriented approach sections, while the vertical bar of this letter "T" may be designed in a channel-like manner, at least near its free end adjacent to the aforementioned overflow opening.

[0008] To ensure that no partial quantity of reducing agent spills over from the first container part into the second container part during intensive acceleration processes of the vehicle, a backflow prevention structure projecting from the wall having this overflow opening can be provided in the first container part below the said overflow opening, which can be designed in the form of a protruding rib or the like.

[0009] To ensure under all circumstances that no reducing agent enters the second container section via the aforementioned overflow opening from the essential section of the first container section – namely, the area near the element used to extract reducing agent from the reducing agent reservoir – as long as the reducing agent level in the second container section remains below this overflow opening, a further partition may be provided in the first container section, creating two compartments within that section. While the first compartment adjoins the aforementioned overflow opening, through which reducing agent enters the first container section from the second due to vehicle acceleration, the second compartment comprises the aforementioned essential section of the first container section.In this second compartment of the first container section, the aforementioned element for extracting reducing agent from the reducing agent container and the aforementioned heating device are arranged. The two compartments are connected by at least one valve device located in the partition wall between them in the base of the first container section. This valve allows the flow of reducing agent from the first compartment to the second compartment and prevents backflow. Besides a conventional check valve, a simple duckbill valve or similar device is also suitable. Such valves simply open the path to the second (and aforementioned "essential section") compartment of the first container section when a certain fill level is reached in the first compartment.

[0010] To ensure that a sufficient quantity of reducing agent is available for the extraction element from the outset after refilling the reducing agent container when it has run empty, a filling pipe or the like, through which the reducing agent container can be filled from the outside, opens into the first part of the container and preferably into the second compartment, if present. Alternatively, a level sensor can be provided in the second part of the container to indicate the level or supply of reducing agent to the operator of the vehicle. This is because, due to the inventive effect that the level in the first part of the container will not be lower than in the second part after the level drops below the overflow opening, the operator of the vehicle can be alerted early on.so that the need to refill the reducing agent container can be pointed out in a timely manner.

[0011] An exemplary embodiment is abstracted to its essentials in the attached principle diagrams, whereby Fig. 1 shows a top view in the vertical direction (towards the roadway), while in Fig. 2 the cut AA from Fig. Figure 1 is shown. Arrow F indicates the usual straight-ahead direction of travel for the motor vehicle in which the depicted reducing agent container is installed. The terms used for the individual components of the reducing agent container are the same as those used in the introductory description; therefore, the respective components will only be briefly explained below, while a more detailed description is provided in the preceding introductory section.

[0012] The reducing agent container shown consists of a first container part 1 and a second container part 2, which are separated from each other by a common wall 3. A partition wall 4 is also provided in the first container part 1, dividing it into a first sub-compartment 11 and a second sub-compartment 12. A unit arranged in the bottom area B of sub-compartment 12 of the first container part 1, consisting of an element for extracting reducing agent from the reducing agent container and a heater for thawing reducing agent frozen in the container, is designated by reference numeral 5.

[0013] In the wall 3 between the two container sections 1 and 2, a transfer opening 6 located higher in the vertical direction and a transfer opening 7 located lower are provided, through which reducing agent can pass from the second container section 2 into the first container section 1; a reverse transfer of reducing agent is also possible, if necessary. While the transfer opening 6 is designed as a simple opening in the wall 3, the transfer opening 7 is designed such that, at a fill level designated L ("Low") in the second container section 2, which, when the vehicle is stationary, lies below this transfer opening 7 in the vertical direction V, reducing agent from the second container section 2 can pass through this transfer opening 7 into the first container section 1, caused by longitudinal or lateral acceleration of the moving vehicle.For this purpose, a ramp 8 leading from the bottom area B of the second container section 2 to the aforementioned overflow opening 7 is provided. Reducing agent from the bottom area B of the second container section 2 can flow along this upwardly rising ramp 8 to the overflow opening 7 and through it into the first container section 1, specifically into its first compartment 11, under the influence of longitudinal or lateral acceleration processes of the vehicle. To ensure that no portion of the reducing agent overflows from the first container section 1 into the second container section 2 during intense acceleration processes of the vehicle, a backflow prevention structure 9 projecting from the wall 3 is provided in the first container section 1 below the aforementioned overflow opening 7. This structure is designed in the form of a protruding rib or the like.

[0014] If the level of reducing agent in the reducing agent container is higher, for example above the transfer opening 6 located in the wall 3 higher than the overflow opening 7, which level is marked with the letter H ("High"), then reducing agent can pass between the two container parts 1 and 2 via this transfer opening 6 just as it would if the level M ("Medium") were at the level of this transfer opening 6.A transfer from the first container section 1 to the second container section 2 through the transfer opening 6 occurs during the filling of the reducing agent container with reducing agent, after a filling pipe (not shown) opens into the compartment 11 or 12 of the first container section 1. A transfer of reducing agent from the second container section 2 to the first container section 1 via the transfer opening 6 occurs during the withdrawal of reducing agent from the compartment 12 of the first container section 1, as long as the fill level in both container sections 1 and 2 is not below the fill level M. After the fill level falls below the fill level M, reducing agent then flows from the second container section 2 through the overflow opening 7 into the first container section 1 as long as the fill level is not below the fill level L.Below the fill level L, the ramp 8 then helps to transfer reducing agent from the second container part 2 into the first container part 1, more precisely into its first sub-chamber 11, in the case of, in particular, a negative longitudinal acceleration (= "braking"), but also a lateral acceleration of the vehicle with a negative longitudinal acceleration component, through which a force oriented essentially in the direction of the vehicle's travel F acts on the reducing agent still located in the second container part 2, in order to transfer reducing agent from the second container part 2 into the first container part 1, more precisely into its first sub-chamber 11.

[0015] From the first sub-chamber 11 of the first container part 1, the reducing agent passes via two valve devices 10 provided in the partition wall 4 into the second sub-chamber 12 of the first container part 1, which valve devices 10 are provided and designed in its bottom area B to allow the transfer of reducing agent from the first sub-chamber 11 to the second sub-chamber 12, but to prevent backflow in the opposite direction.

Claims

[1] Reducing agent tank of a motor vehicle comprising a first tank part (1) in the base (B) of which a heating device (5) and an element (5) for extracting reducing agent from the tank are provided, and a second tank part (2) which has at least one wall (3) common with the first tank part (1) in which at least one overflow opening (7) between the first and the second tank part (1, 2) is arranged or designed in such a way that at a certain fill level (L) in the first tank part (1), which may itself be subdivided by a partition (4), no reducing agent can enter the second tank part (2) from this or any other overflow opening (7) during normal operation of the vehicle, characterized by, that at least one overflow opening (7) is designed such that, when the fill level (L) in the second container part (2) is below this overflow opening (7) when the vehicle is stationary horizontally, reducing agent from the second container part (2) can enter the first container part (1) via this overflow opening (7) due to longitudinal or lateral acceleration of the moving vehicle, and that (a) in the second container part (2) a ramp (8) leading from its bottom area (B) to the said overflow opening (7) is provided, and / or (b) in the first part of the container (1) below said overflow opening (7) a backflow prevention structure (9) projecting from the wall (3) having this overflow opening (7) is provided. [2] Reducing agent container according to claim 1, with a partition (4) in the first container part (1) which separates a first sub-chamber (11) into which the said overflow opening (7) from the second container part (2) opens, from a second sub-chamber (12) in which the heating device (5) and the said extraction element (5) are provided, wherein at least one valve device (10) is provided in this partition (4) in the bottom area (B) of the first container part (1) which allows a transfer of reducing agent from the first sub-chamber (11) into the second sub-chamber (12) and prevents backflow. [3] Reducing agent container according to one of the preceding claims, wherein a filling tube or the like, through which the reducing agent container can be filled from the outside, opens into the first container part (1) and preferably into the second sub-chamber (12) of the same, if any, existing. [4] Reducing agent container according to one of the preceding claims, wherein a level sensor is provided in the second container part (2) to indicate the level or supply of reducing agent to the operator of the motor vehicle.

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