Delivery device with filter element

Abstract

The invention relates to a delivery device for aqueous urea solution in a motor vehicle, having a container, a filter element and a pump, wherein aqueous urea solution can be delivered by means of the pump from the container via the filter element into a suction line, wherein the filter element has a filter material and a frame for accommodating the filter material, wherein the filter material is connected to the frame by means of a connecting element, wherein the connecting element is part of the fluid delivery line from the container via the filter element to the pump.

Description

Technical Field

[0001] The present invention relates to a device for conveying an aqueous urea solution in a motor vehicle, comprising a container, a filter element and a pump, wherein the aqueous urea solution can be conveyed from the container through the filter element to a suction line by means of the pump, wherein the filter element has a filter material and a frame for containing the filter material. Background Technology

[0002] Globally, many countries have established laws and regulations that set upper limits on the content of specific substances in the exhaust of internal combustion engines. These specific substances are mostly those that are undesirable for emission into the environment. One such substance is nitrogen oxides (NOx), whose share in exhaust cannot exceed legally prescribed limits. Due to framework conditions, such as the design of internal combustion engines for optimal fuel consumption, the avoidance of NOx emissions within the engine can only be limited when reducing the share of NOx in exhaust, thus requiring exhaust aftertreatment to comply with lower limits. Selective catalytic reduction (SCR) of NOx has proven advantageous. This SCR method requires a nitrogen-containing reducing agent. In particular, the use of ammonia (NH3) as a reducing agent has proven to be a possible alternative. Due to its chemical properties and the legal regulations of many countries, ammonia is generally not stored as pure ammonia, as this could cause problems, especially in motor vehicles or other mobile applications. Instead, instead of storing the reducing agent itself, reducing agent precursors are typically stored and carried. Reducing agent precursors are specifically understood as substances that can decompose into a reducing agent or be chemically converted into a reducing agent. For the reducing agent ammonia, urea is, for example, a reducing agent precursor.

[0003] Ammonia solution and urea are carried in containers and delivered to the exhaust system in precise dosages via suitable delivery devices. For this purpose, the delivery device typically includes a pump for conveying the fluid, one or more filters for cleaning the fluid, a heating device for thawing the fluid if necessary, and a control device for processing internal and external data and for driving the pump, heating device, and other controllable components, such as injectors.

[0004] A particularly disadvantageous aspect of existing devices is that, to date, no device has been able to ensure the use of products of sufficient quality and technical functionality when replacing filters, and thus ensure the functionality of the entire device. Summary of the Invention

[0005] Therefore, the object of the present invention is to provide a conveying device having a means of excluding or at least preventing the replacement of filters for unsuitable replacement media.

[0006] This objective is achieved in terms of the conveying device by a conveying device having the features of claim 1.

[0007] Embodiments of the present invention relate to a device for conveying an aqueous urea solution in a motor vehicle, comprising a container, a filter element, and a pump, wherein the aqueous urea solution can be conveyed from the container via the filter element to a suction line by means of the pump, wherein the filter element has a filter material and a frame for containing the filter material, wherein the filter material is connected to the frame by means of a connecting element, wherein the connecting element is part of the fluid delivery path from the container via the filter element to the pump.

[0008] A urea solution (hereinafter referred to as the fluid) is pumped from a container to a consumer, such as an injector in an exhaust line. Here, the fluid is conveyed from the container via filter material to the pump's suction line, from where it is further conveyed to the consumer. Special valves for controlling fluid flow and devices for degassing, particularly for removing air from the pipeline, can be installed along the pipeline.

[0009] Filter materials can be formed, for example, from mesh materials, porous materials, or elements with multiple openings that allow fluid to flow through but block solids larger than a certain size. Such filter materials are known in various ways in the prior art.

[0010] A key feature of filter media is that it is designed so that fluid from the container can flow into the suction line only through a defined cross-section. For example, filter media can be configured in multiple layers to form a bag, thereby creating an area for the filtered fluid within a containment space expanded by the bag. The filtered fluid can only overflow from this area into the suction line leading to the pump, for example, through a defined cross-section formed by defined openings in the bag.

[0011] In the space created by the filter material, it is preferable to provide a support structure that supports the formation of the space and, in particular, prevents the filter material from collapsing.

[0012] The suction line specifically refers to the section of the fluid delivery line that connects downstream of the filter and upstream of the pump along the conventional flow direction (from the container to the pump). The line is located on the suction side of the pump. The suction line can also extend along various housing sections of the delivery device. In particular, a portion forming the frame for the filter material or housing the filter material can also be designed as part of the suction line.

[0013] Frames are particularly used for fixing and / or shaping filter media. Depending on the filter media used, additional support structures or frames may be required to support the filter media and thus create sufficient filtration surface. The frame may have anchor points to which the filter media can be attached.

[0014] Alternatively, the frame may have multiple tabs and ribs that form a support that opens up a space in which the filter material is preferably arranged.

[0015] As already mentioned, the frame can be, in particular, the portion of the fluid delivery route connected upstream of the pump, such that the frame has, for example, a connection point where filter material is connected to the frame, so that the filtered fluid, from the volume expanded by the filter material, can flow through the connection point into the suction line.

[0016] In its simplest form, the frame is part of the housing of the device and is formed only by connection points or joints for the filter material, and additionally, if necessary, forms a support surface on which the filter material can be supported at least partially, especially on one side.

[0017] To connect the filter media to the frame, a connecting element is provided, which creates a fluid-tight and durable connection between the filter media and the frame. The connection points on the filter media and / or the frame can therefore have connectors that can be easily connected to the connecting element. In particular, grooves, protrusions, threads, or other profiles can be provided.

[0018] The connecting element can be an additional component that connects to the frame and filter material, or it can be fixedly mounted on one side. In one advantageous embodiment, the connecting element can be fixedly connected to the filter material, thus requiring only an additional connection between the connecting element and the frame. The connecting element with the connected filter material can be, for example, pressed in, screwed in, or otherwise connected to a receiving area on the frame.

[0019] Alternatively, the connecting element can be fixedly connected to the frame, thereby pressing or screwing the filter material into the connecting element. However, the connection principle remains the same here.

[0020] A particular advantage is that the connecting element partially secures the filter material relative to the frame. As already mentioned, the frame is preferably part of the housing of the device.

[0021] In a preferred embodiment, the device is configured to have a can-shaped shell, which is mounted into the container through an opening in the container wall, preferably an opening in the wall forming the bottom, and connected to the wall by a surrounding flange.

[0022] Pumps and other components, such as control devices, are preferably arranged on the side of the tank-shaped shell facing away from the container, and therefore do not come into direct contact with the fluid.

[0023] Advantageously, the frame has fluid lines that come into contact with / connect to the pump fluid, wherein the fluid lines on the frame have inlets, and the filter material is connected to the inlets via connecting elements. The inlets are positioned directly adjacent to the connection point between the filter material and the frame.

[0024] In a particularly preferred embodiment, the inlet is part of the connection, ensuring that fluid from the space created by the filter material flows directly into this inlet and thus into the downstream fluid conduit. The fluid conduit can be formed, for example, by a short section, such as through a hole in the housing wall, or by a longer channel section or conduit extending within the wall. Depending on the configuration, the fluid conduit can be identical to a suction line that is technically connected upstream of the pump and downstream of the filter.

[0025] A preferred embodiment is characterized in that the connecting element creates a fluid-tight connection between the filter material and the fluid conduit. Therefore, the connecting element is a sealing element that seals the connection between the filter material and the connection point on the frame. According to the invention, the device is specifically designed such that a missing connecting element or a damaged filter element results in a non-sealing condition, thereby compromising the functionality of the device.

[0026] In particular, opening the connection between the filter material and the frame leads to the destruction of the connecting element, thereby no longer ensuring functionality and making the connection physically unstable and / or fluidly unsealed.

[0027] Preferably, the connecting elements create a connection between the frame and the filter material that cannot be released in a non-destructive manner. A key characteristic of this non-destructive connection is that the connection between the elements to be connected can only be established once during normal installation. Subsequent opening of the connection results in damage to the connecting elements, or at least severe damage.

[0028] Furthermore, it is advantageous to create a connection that cannot be released in a non-destructive manner through bayonet / screw-type connections. This is advantageous, for example, by facilitating the connection by twisting the two parts to be connected relative to each other, or, in a particularly preferred embodiment, by simply twisting the connecting element relative to the filter material and / or the frame. Bayonet connections, in particular, do not require high torsional angles between the involved parts, thus enabling durable connections even in confined spaces.

[0029] Furthermore, it is advantageous that the connection, which cannot be released non-destructively, is formed by a stop pawl that breaks when a sufficiently high force is applied in the opposite direction to the closing direction. The stop pawl is formed, for example, by a molded body that protrudes radially inward from the inner circumferential surface of the opening, the molded body being arranged at an angle in the circumferential direction. This is preferably formed on a connecting element designed as a ring. A shaped portion is provided, for example, on the outer periphery of the mating member, on which the connecting element is disposed, the shaped portion being designed such that the stop pawl slides on the shaped portion in one rotational direction; however, locking exists when the stop pawl is guided on the shaped portion in the opposite direction.

[0030] As is well known, this principle is implemented, for example, in the one-way clutch of a bicycle wheel hub. The shaped parts and locking claws on the outer periphery can be designed in a variety of ways. The core concept is that two elements, especially the connecting element and the filter material and / or frame, can be twisted relative to each other in one direction of rotation and locked together in opposite directions.

[0031] If the force applied to the connection is large enough to break the stop pawl, the connection will loosen and a fixed, fluid-tight connection can no longer be established.

[0032] Furthermore, it is preferable that the closure direction of the connection, which cannot be loosened in a non-destructive manner, is rotational or translational. Depending on how the connecting element should be connected to the filter material and / or frame, it may be advantageous to establish the connection through translational movement or rotational torsion. Bayonet connections are preferably created by torsion, while plug connections are created, for example, by linear translational movement.

[0033] The principle of the locking pawl can also be used for plug connections generated by translational motion. Here, the locking element protruding from the inner periphery can be fixed, for example, by pressing it onto the protrusion or into the groove, thereby creating a fixed fluid-tight connection through form-locking. Applying a force in the opposite direction to the plug eventually causes the locking element to break due to shearing action.

[0034] Furthermore, it is advantageous that a connection that cannot be released non-destructively is created when the filter material is connected to the frame via the connecting elements, and that this non-destructive connection is broken when the filter material is detached from the frame. This is particularly advantageous because, according to the invention, the connection should be created once during installation, and disassembly and reinstallation should be avoided.

[0035] Furthermore, it is preferable that the connecting element is designed as a ring, wherein the connection between the connecting element and the filter material and / or frame is designed to be non-destructive and cannot be loosened.

[0036] The connecting element is preferably a ring, wherein the connecting portion on the frame and / or filter material preferably has a corresponding cross-section, allowing the ring to be disposed thereon. In a preferred embodiment, the connecting element as a ring can be arranged on the filter material or frame and is permanently or releasably connected to the filter material or frame, for example, via a threaded connection. Connections to other corresponding elements are then created through a connection that cannot be released in a non-destructive manner. In this way, easy installability is ensured on the one hand, and on the other hand, a non-destructive connection is created through at least one of the elements, preventing reinstallation after the first loosening.

[0037] In a preferred embodiment, the connecting element may have threads on one side, which are used to screw the connecting element onto the frame, for example. In this case, the filter material is connected to the connecting element, for example, using a bayonet connection, which has a connection that cannot be loosened in a non-destructive manner. For this purpose, the annular connecting element may, for example, have two sections that are rotatable relative to each other, which are twisted relative to each other after the filter material is inserted, and the filter material is secured here using the connection described earlier. This allows for installation in space-constrained working environments and also allows for easy replacement of the connecting element after the connection with the filter material is broken.

[0038] Preferably, in such an embodiment, the connecting element can be designed such that loosening of the threaded connection with the frame also automatically leads to the breakdown of the connection with the filter material. This can be achieved in such a way that the two relatively torsionally oriented sections of the ring are designed such that tension of the ring at the connection point with the frame is possible, and conversely, loosening of the ring from the connection point leads to the destruction of the retaining pawl. This can be achieved, for example, in such a way that the two relatively torsionally oriented sections twist relative to each other upon loosening, thereby destroying the retaining pawl and thus no longer ensuring a secure and fluid-tight connection.

[0039] According to the design scheme, threaded connections with the filter material can also be created, as well as connections with the frame that cannot be loosened in a non-destructive manner.

[0040] The embodiments described herein are exemplary and are intended to illustrate the concept of the invention. These embodiments are not intended to be limiting.

[0041] Advantageous improvements to the invention are described in the dependent claims.

Claims

1. A conveying device for a urea aqueous solution in a motor vehicle, the conveying device comprising a container, a filter element, and a pump, wherein, A pump can transport an aqueous urea solution from a container through a filter element to a suction line. The filter element has a filter material and a frame for containing the filter material. The filter material is connected to the frame by means of a connecting element, which is part of the fluid transport path from the container through the filter element to the pump. The connecting element partially fixes the filter material relative to the frame, which has a fluid conduit in contact with the pump fluid. The fluid conduit on the frame has an inlet, and the filter material is connected to the inlet via the connecting element. The connecting element creates a non-destructive connection between the frame and the filter material, and also creates a fluid-tight connection between the filter material and the fluid conduit.

2. The conveying device according to claim 1, characterized in that, Connections that cannot be released non-destructively are created using bayonet-type connectors.

3. The conveying device according to claim 1 or 2, characterized in that, A connection that cannot be released in a non-destructive manner is formed by a stop pawl that breaks when a force is applied sufficiently high in the opposite direction to the closing direction.

4. The conveying device according to any one of claims 1 to 3, characterized in that, A connection that cannot be released in a non-destructive manner is closed in a direction of rotation or translation.

5. The conveying device according to any one of claims 1 to 4, characterized in that, The connection that cannot be released in a non-destructive manner is created when the filter material is connected to the frame via the connecting element, and the connection that cannot be released in a non-destructive manner is broken when the filter material is released from the frame.

6. The conveying device according to any one of claims 1 to 5, characterized in that, The connecting element is designed as a ring, wherein the connection between the connecting element and the filter material and / or frame is designed to be non-destructive and cannot be released.