Fluid transport device having a fluid connection piece, and method for connecting a fluid connection piece to a fluid transport device

Abstract

A fluid transport device (40), in particular a fluid transport device (40) for transporting a fluid reducing agent (34) in an exhaust aftertreatment system (30) for the aftertreatment of exhaust gases (48) of a combustion engine (38), comprises a fluid channel (42) which extends from an open end (16), which is formed on an outer side of the fluid transport device (40), into the interior of the fluid transport device (40), and a fluid connection piece (2) which has been inserted through the open end (16) into the fluid channel (42). Formed between an outer periphery of the fluid connection piece (2) and a wall of the fluid channel (42) is an intermediate space (12), and a filler material (14), which seals off the intermediate space (12) in a fluid-tight manner, has been introduced into the intermediate space (12).

Description

[0001] Description

[0002] title with fluid connector and method for connecting a fluid connector with a

[0003] The invention relates to a fluid delivery device, in particular a fluid delivery device for delivering a fluid reducing agent in a system for the aftertreatment of exhaust gases from an internal combustion engine. The invention also relates to a system for the aftertreatment of exhaust gases from an internal combustion engine, comprising a fluid delivery device according to the invention, a motor vehicle equipped with such a system, and a method for connecting a fluid connector to a fluid delivery device.

[0004] State of the art

[0005] To reduce the nitrogen oxides (NOx) contained in the exhaust gases of an internal combustion engine, particularly a diesel engine, a liquid reducing agent in the form of a urea-water solution (AdBlue®) is often injected into the exhaust system of the internal combustion engine. The reducing agent reacts with the nitrogen oxides contained in the exhaust gases in a catalyst located in the exhaust system of the internal combustion engine.

[0006] The liquid reducing agent is stored in a reservoir or tank and conveyed by a fluid conveying device containing a fluid pump to a metering module mounted on the exhaust system of the internal combustion engine, which module includes an injection device. The injection device injects the reducing agent into the exhaust system in a metered manner.

[0007] Urea water solution freezes at temperatures of approximately -11.5 °C. Volume expansion associated with the freezing of the reducing agent can lead to damage to the fluid conveying device.

[0008] Disclosure of the invention: It is an object of the invention to provide a fluid conveying device which is not damaged by freezing reducing agent, in particular not by the volume expansion of freezing reducing agent, when the ambient temperatures fall below the freezing point of the reducing agent.

[0009] A fluid delivery device according to the invention, in particular a fluid delivery device for delivering a fluid reducing agent in a system for the aftertreatment of exhaust gases of an internal combustion engine, comprises a fluid channel extending from an opening formed on an outer side of the fluid delivery device into the interior of the fluid delivery device. The fluid delivery device further comprises a fluid connector inserted through the opening into the fluid channel such that a gap is formed between an outer circumference of the fluid connector and a wall of the fluid channel. A filler material is introduced into the gap such that it seals the gap fluid-tight.

[0010] A method according to the invention for connecting a fluid connector to a fluid delivery device, in particular to a fluid delivery device which is provided for delivering a fluid reducing agent in a system for the aftertreatment of exhaust gases of an internal combustion engine, comprises: inserting a fluid connector into a fluid channel formed in the fluid delivery device such that an intermediate space is formed between an outer circumference of the fluid connector and a wall which delimits the fluid channel, and introducing a filling material into the intermediate space such that the filling material seals the intermediate space in a fluid-tight manner.

[0011] The invention also includes a system for aftertreating exhaust gases of an internal combustion engine with a fluid conveying device according to the invention for conveying the fluid reducing agent and a motor vehicle with an internal combustion engine which is equipped with a system according to the invention for aftertreating the exhaust gases of the internal combustion engine.

[0012] The filling material introduced into the space between the fluid connector and the wall of the fluid channel reliably prevents fluid, in particular water or fluid reducing agent, such as urea water solution, from penetrating into the space, freezing there at low ambient temperatures and damaging the fluid connector and / or the fluid channel due to the volume expansion associated with freezing.

[0013] In one embodiment, the filler material is a thermally conductive material, such as a thermal paste. A thermally conductive filler material can increase the supply of heat to frozen fluid located in the fluid channel. This can accelerate the thawing of frozen fluid. The filler material can also be a silicone resin, an epoxy resin, a polyamide, or a polyester resin.

[0014] In one embodiment, a sealing ring, in particular an O-ring, is arranged on the outer circumference of the fluid connector. The filling material can be introduced, in particular, into a section of the intermediate space that extends from an open end of the fluid channel to the sealing ring. The sealing ring can prevent fluid and / or filling material from undesirably penetrating from the intermediate space into the fluid channel. The sealing ring can limit the amount of filling material that can be introduced into the intermediate space.

[0015] In one embodiment, the fluid connector has a first section with a first diameter and a second section with a second diameter that differs from the first diameter. The second diameter may, in particular, be smaller than the first diameter.

[0016] In one embodiment, the fluid connector is inserted into the fluid channel such that the first portion is arranged closer to the open end of the fluid channel than the second portion.

[0017] The fluid channel can be configured accordingly with an outer region at the open end and an inner region, the outer region having a larger diameter than the inner region. The penetration depth of the fluid connector into the fluid channel can thus be limited by the length of the outer region of the fluid channel and the first region of the fluid connector and adjusted to a desired value. In one embodiment, the first section has a first diameter in the range between 5 mm and 7 mm and / or the second section has a second diameter in the range between 2 mm and 4 mm.

[0018] In one embodiment, the first section has a first length in the range between 28 mm to 33 mm and / or the second section has a second length in the range between 18 mm to 20 mm.

[0019] In one embodiment, the filler material is arranged around the first portion of the fluid connector.

[0020] A filter element may be provided in the fluid connector to filter fluid flowing through the fluid connector.

[0021] Embodiments of the invention are described below with reference to the accompanying drawings.

[0022] Short the

[0023] Figure 1 shows a schematic view of a motor vehicle with an internal combustion engine and an exhaust gas aftertreatment system.

[0024] Figure 2A shows a perspective view of a fluid connector.

[0025] Figure 2B shows a side view of the fluid connector shown in Figure 2A.

[0026] Figure 3 shows a section through the fluid connector, which is arranged in a fluid channel of a fluid conveying device.

[0027] An embodiment of the invention is described below with reference to the accompanying figures.

[0028] Figure 1 shows a schematic view of a motor vehicle 60 with an internal combustion engine 38, in particular with a diesel engine, and with an exhaust gas aftertreatment system 30 which is designed for aftertreating the exhaust gases 48 of the internal combustion engine 38.

[0029] The exhaust gas aftertreatment system 30 comprises a catalyst 50 arranged in an exhaust system 36 of the internal combustion engine 38, and a system 31 for introducing a fluid reducing agent 34, in particular an aqueous urea solution (“AdBlue®”) stored in a reservoir 32, into the exhaust system 36 of the internal combustion engine 38.

[0030] During operation of the exhaust gas aftertreatment system 30, fluid reducing agent 34, which is also referred to below as "fluid", is withdrawn from the reservoir 32 via a fluid line 33 and is supplied by a fluid conveying device 40, which has a fluid pump 45, under increased pressure via a suitable fluid line ("pressure line") 20 to a dosing module 44, which is arranged on the exhaust line 36 of the internal combustion engine 38.

[0031] The pressure line 20 opens into a fluid channel 42 formed in the fluid conveying device 40. A fluid connector 2 is arranged in the fluid channel 42 and is fluidically connected to the pressure line.

[0032] The dosing module 44 comprises an injection device designed and configured to inject the reducing agent 34 into the exhaust system 36 in a metered manner as a spray 46. In the exhaust system 36, the injected reducing agent 34 mixes with the exhaust gases 48 of the internal combustion engine 38 flowing through the exhaust system 36 and reacts with the nitrogen oxides contained in the exhaust gases 48 to form water and nitrogen in the catalyst 50 provided downstream of the dosing module 44 in the exhaust system 36.

[0033] The exhaust gas aftertreatment system 30 comprises a plurality of sensors 52, 54, 56, for example temperature sensors 52, 54, which are arranged upstream and downstream of the catalyst 50 on or in the exhaust line 36, and a nitrogen oxide sensor (“NO x -Sensor”) 56, which is arranged downstream of the catalyst 50 in the exhaust system 36.

[0034] The sensors 52, 54, 56 deliver their measurement results to a control unit 58, which is designed to control the components of the exhaust gas aftertreatment system 30, in particular the fluid conveying device 40 and the dosing module 44, in such a way that the nitrogen oxides contained in the exhaust gases 48 of the internal combustion engine 38 are reduced to nitrogen and water as best as possible.

[0035] Figure 2A shows a perspective view of a fluid connector 2, as it can be arranged in the fluid channel 42 formed in the fluid conveying device 40. Figure 2B shows a side view of the fluid connector 2.

[0036] The fluid connector 2 has a first section 4, shown on the left in Figures 2A and 2B, which has a first diameter d1 and a first length L1. The fluid connector 2 has a second section 6, shown on the right in Figures 2A and 2B, which has a second diameter d2 and a second length L2.

[0037] The first diameter di of the first section 4 is larger than the second diameter d2 of the second section 6.

[0038] The first section 4 can, for example, have a first diameter di in the range between 5 mm to 7 mm and a first length Li in the range between 28 mm to 33 mm.

[0039] The second section 6 can, for example, have a second diameter d2 in the range between 2 mm to 4 mm and a second length L2 in the range between 18 mm to 20 mm.

[0040] Between the first section 4 and the second section 6, a conical section 8 is formed, which widens from the second diameter d2 of the second section 6 to the first diameter di of the first section 4 and which connects the first section 4 to the second section 6.

[0041] An elastic sealing ring 10 is arranged around a region of the first section 4, which is located in particular at the end of the first section 4 facing the conical section 8. The sealing ring 10 can in particular be designed as an O-ring.

[0042] The fluid connector 2 can be made of metal or plastic. A filter element (not shown in the figures) can be provided in the fluid connector 2 to filter fluid 34 flowing through the fluid connector 2.

[0043] Figure 3 shows a section through a fluid connector 2, which is arranged in a fluid channel 42 of a fluid conveying device 40.

[0044] The fluid connector 2 is arranged in the fluid conveying device 40 such that the first section 6 of the fluid connector 2 is located at an outer, open end 16 of the fluid channel 42, shown on the right in Figure 3. The first section 6 of the fluid connector 2 is fluidically connected to the pressure line 20, not shown in Figure 3.

[0045] The first diameter di of the first section 4 of the fluid connection piece 2 is slightly smaller than the inner diameter di of the fluid channel 42. As a result, a gap 12 is formed between the outer circumference of the first section 4 of the fluid connection piece 2 and the wall of the fluid channel 42.

[0046] The gap 12 can have a width of up to 5 mm in the radial direction. The gap 12 can, in particular, have a width between 0.15 and 0.7 mm in the radial direction.

[0047] A filler material 14 is introduced into the intermediate space 12, which seals the intermediate space 12 in a fluid-tight manner. The filler material 14 prevents fluid 34 from penetrating the intermediate space 12 and preventing a volume expansion of fluid 34 that freezes in the intermediate space 12 from damaging the fluid connector 2 and / or the housing of the fluid conveying device 40 in which the fluid channel 42 is formed.

[0048] The filling material 14 can be a thermally conductive material, in particular a thermal paste, and / or a silicone resin, an epoxy resin, a polyamide or a polyester resin.

[0049] A thermally conductive filler material 14 can increase the supply of heat to frozen fluid 34 located in the fluid channel 42 and thereby accelerate the thawing of the frozen fluid 34. The filler material 14 extends, in particular, over a region of the intermediate space that extends between the open end 16 of the fluid channel 42 and the sealing ring 10. The filler material 14 can, in particular, be introduced into the intermediate space 12 through the open end 16 of the fluid channel 42. The penetration of the filler material 14 into the fluid channel 42 can be limited by the sealing ring 10.

Claims

1. A fluid conveying device (40), in particular a fluid conveying device (40) for conveying a fluid reducing agent (34) in an exhaust gas aftertreatment system (30) for the aftertreatment of exhaust gases (48) of an internal combustion engine (38), wherein the fluid conveying device (40) comprises: a fluid channel (42) extending from an open end (16) formed on an outer side of the fluid conveying device (40) into the interior of the fluid conveying device (40), and a fluid connection piece (2) inserted through the open end (16) into the fluid channel (42), wherein an intermediate space (12) is formed between an outer circumference of the fluid connection piece (2) and a wall of the fluid channel (42), and wherein a filling material (14) which seals the intermediate space (12) in a fluid-tight manner is introduced into the intermediate space (12).

2. Fluid conveying device (40) according to claim 1, wherein the filling material (14) is a thermally conductive material, in particular a thermally conductive paste, and / or a silicone resin, an epoxy resin, a polyamide or a polyester resin.

3. Fluid conveying device (40) according to claim 1 or 2, wherein a sealing ring (10), in particular an O-ring, is arranged on the outer circumference of the fluid connection piece.

4. Fluid conveying device (40) according to claim 3, wherein the filling material (14) is introduced into a portion of the intermediate space (12) extending from the open end (16) of the fluid channel (42) to the sealing ring (10).

5. Fluid conveying device (40) according to one of the preceding claims, wherein the fluid connector (2) has a first section (4) with a first diameter (d1) and a second section (6) with a second diameter (d2), wherein the second diameter (d2) is smaller than the first diameter (d1), wherein the fluid connector (2) is inserted into the fluid channel (42) such that the first section (4) is arranged closer than the second section (6) to the open end (16) of the fluid channel (42), wherein the filling material (14) is arranged in particular around the first section (4) of the fluid connector (2), 6. Fluid conveying device (40) according to one of the preceding claims, wherein the first section (4) has a first diameter (di) in the range between 5 mm to 7 mm and / or wherein the second section has a second diameter (d2) in the range between 2 mm to 4 mm.

7. Fluid conveying device (40) according to one of the preceding claims, wherein the first section (4) has a first length (Li) in the range between 28 mm to 33 mm and / or wherein the second section (6) has a second length (L2) in the range between 18 mm to 20 mm.

8. Exhaust gas aftertreatment system (30) for aftertreating exhaust gases (48) of an internal combustion engine (38) with a fluid conveying device (40) for conveying a fluid reducing agent (34), wherein the fluid conveying device (40) is a fluid conveying device (40) according to one of the preceding claims.

9. Motor vehicle (60) with an internal combustion engine (38) and with an exhaust gas aftertreatment system (30) for aftertreating exhaust gases (48) of the internal combustion engine (38), wherein the exhaust gas aftertreatment system (30) is an exhaust gas aftertreatment system (30) according to claim 8.

10. Method of connecting a fluid connector (2) to a fluid conveying device (40), in particular a fluid conveying device (40) for conveying a fluid reducing agent (34) in an exhaust gas aftertreatment system (30) for aftertreating exhaust gases (48) of an internal combustion engine (38), the method comprising: Inserting a fluid connector (2) into a fluid channel (42) formed in the fluid conveying device (40), wherein an intermediate space (12) is formed between an outer circumference of the fluid connector (2) and a wall which delimits the fluid channel (42), and Introducing a filling material (14) into the intermediate space (12) so that the filling material (14) seals the intermediate space (12) in a fluid-tight manner.

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