Method and device for removing and testing an injector

Abstract

A device (30) for removing and testing an injector (92), in particular for removing an injector (92) from an injection device (90) for exhaust aftertreatment, comprises an adapter plate (6) designed to receive an injection device (90) with an injector (92); a screw-in adapter (14) with a substantially cylindrical area (14a, 14b) that can be inserted into an opening formed in the injection device (90), wherein an axial bore (18) is formed in the substantially cylindrical area (14a, 14b) which extends along a longitudinal axis (A) of the substantially cylindrical area (14a, 14b); and a push-out mandrel (20) which can be inserted into the injection device (90) through the bore formed in the substantially cylindrical area (14a, 14b) in order to push the injector (92) out of the injection device (90).A device (30) according to the invention can additionally include a test adapter (32) which makes it possible to introduce a gas, in particular air, into the injection device (90) in order to check the injection device (90) for leaks.

Description

[0001] The invention relates to a method and a device for removing and testing an injector; in particular, a method and a device for removing and testing an injector from a metering module for exhaust aftertreatment. State of the art

[0002] Exhaust aftertreatment using a fluid reducing agent (“AdBlue”) is a common technology for reducing harmful emissions from diesel engines, particularly nitrogen oxides. By using exhaust aftertreatment systems, diesel-powered vehicles, especially trucks, can meet stringent emissions standards and reduce environmental pollution.

[0003] An exhaust aftertreatment system essentially comprises a delivery module for conveying the fluid reducing agent, a metering module with an injector to introduce the fluid reducing agent into the exhaust stream of an internal combustion engine, a catalyst located downstream of the metering module in the exhaust stream of the internal combustion engine, and a control unit designed and configured to control the delivery module and the metering module to introduce an amount of reducing agent into the exhaust stream adapted to the respective operating condition of the internal combustion engine.

[0004] The injector is a wear component of an exhaust aftertreatment system that must be replaced when necessary to ensure the continued proper functioning of the exhaust aftertreatment system.

[0005] It is environmentally friendly and cost-effective to replace only the injector, rather than the entire dosing module. This requires removing the injector from the dosing module.

[0006] The housing of the dosing module, which is often made of a soft metal, especially aluminium, must not be damaged or deformed.

[0007] After the injector has been replaced with a new injector, the combination of the dosing module and the new injector must be checked for leaks before installation in the motor vehicle.

[0008] It is therefore an object of the invention to provide devices and methods that facilitate both the non-destructive removal of an injector from a metering module and the checking of a metering module with an injector for leaks. Disclosure of the invention

[0009] An inventive device for removing and testing an injector, in particular for removing an injector from a metering module for exhaust aftertreatment, comprises an adapter plate designed to receive an injection device with an injector; a screw-in adapter with a substantially cylindrical area that can be inserted into an opening formed in the injection device, wherein a bore is formed in the substantially cylindrical area that extends along a longitudinal axis of the substantially cylindrical area; and a push-out mandrel that can be inserted into the injection device through the bore formed in the substantially cylindrical area in order to push the injector out of the injection device.

[0010] A method according to the invention for dismantling an injector from an injection device using a device according to the invention comprises mounting the injection device with the injector on the adapter plate of the device; screwing the screw-in adapter into the screw-in opening formed in the adapter plate; and guiding the ejector pin through the bore formed in the screw-in adapter to push the injector out of the injection device. The method particularly includes screwing the ejector pin into the bore formed in the screw-in adapter.

[0011] With a device and a method according to the invention, an injector can be removed from an injection device simply, safely and without damage, without damaging the injector or the injection device.

[0012] This makes it possible to replace the injector of an exhaust aftertreatment system without replacing the injection device or the metering module. This saves the cost of a new injection device and / or a new metering module, and protects the environment.

[0013] In one embodiment, fastening elements, in particular fastening holes, are formed on or in the adapter plate, which make it possible to fasten the injection device in a predetermined position on the adapter plate.

[0014] In one embodiment, the adapter plate has at least one screw-in opening into which the screw-in adapter can be screwed. In this way, the screw-in adapter can be positioned in a predetermined position relative to the injection device located on the adapter plate.

[0015] In one embodiment, the screw-in opening is formed with an internal thread, and the essentially cylindrical area of ​​the screw-in adapter is formed with a corresponding external thread that can be screwed into the internal thread formed in the screw-in opening. In this way, the screw-in adapter can be easily and securely fixed in the screw-in opening.

[0016] In one embodiment, knurling is provided on a grip area of ​​the screw-in adapter. This improves the handling, and in particular the screw-in ease, of the screw-in adapter.

[0017] In one embodiment, the mandrel has a first cylindrical section with a first diameter and a second cylindrical section with a second diameter, the second diameter being larger than the first diameter. The first cylindrical section can, in particular, have a first diameter in the range between 4.6 mm and 4.9 mm, and more specifically, a second diameter of 4.7 mm.

[0018] In one embodiment, the second cylindrical area has a length between 45 mm and 46 mm, in particular a length of 45.5 mm, and the first cylindrical area has a length between 19 mm and 20 mm, in particular a length of 19.5 mm.

[0019] A mandrel with such dimensions has proven to be particularly well suited for pushing an injector out of the injection device using the mandrel.

[0020] In one embodiment, a chamfered or conical section is formed between the first and second sections of the mandrel. This chamfered or conical section can be angled between 40° and 50°, particularly at an angle of 45°, to a longitudinal axis of the mandrel. Such a chamfered or conical section can prevent the mandrel from jamming and becoming stuck in a bore at the transition between the first and second sections.

[0021] In one embodiment, the screw-in adapter has an internal thread, in particular an M10 internal thread, and the first cylindrical section of the ejector mandrel has an external thread, in particular an M10 external thread. This allows the ejector mandrel to be screwed into the screw-in adapter in order to push the injector out of the injection device using the ejector mandrel.

[0022] In one embodiment, the device additionally comprises a test adapter having an external thread that can be screwed into the screw-in opening. The test adapter particularly has a connection area to which a fluid line, for example a fluid hose, can be connected to supply a fluid, especially air, to the test adapter.

[0023] The invention also includes a method for checking the tightness of an injection device with an injector using a device according to the invention with a test adapter, wherein the method comprises mounting the injection device on the adapter plate; screwing the test adapter into the screw-in opening formed in the adapter plate; connecting the connection area of ​​the test adapter to a fluid line, in particular a hose; and introducing a fluid, in particular air, into the injection device through the fluid line and the test adapter and detecting fluid escaping from the injection device and / or the injector in order to check the tightness of the injection device and the injector.

[0024] The method may in particular include submerging the injection device in water and detecting gas, especially air, escaping from the injection device in the form of gas or air bubbles rising in the water ("bubble test").

[0025] In this way, leaks in the injection system can be detected easily and reliably. Brief description of the characters

[0026] An embodiment of the invention is described below with reference to the accompanying figures. Fig. Figure 1A shows a schematic view of a motor vehicle with an exhaust aftertreatment system comprising a metering module with an injection device. Fig. Figure 1B shows an exploded view of an injection device with one injector. Fig. Figure 2 shows an injection device removed from a motor vehicle with an injector arranged on an adapter plate according to the invention. Fig. Figure 3 shows a top view of an adapter plate designed according to an embodiment of the invention. Fig. Figure 4A shows a perspective view of a screw-in adapter designed according to an embodiment of the invention. Fig. 4B shows a sectional view of the [unclear text] in the Fig. 4A screw-in adapter shown. Fig. Figure 5A shows a view of a mandrel according to an embodiment of the invention. Fig. Figure 5B shows a top view of a screw-in head of the print mandrel. Fig. Figure 6A shows a perspective view of a device for removing and testing an injector according to an embodiment of the invention. Fig. 6B shows a cross-section through the Fig. Device shown in 6A. Fig. Figure 7 illustrates the use of a device according to the invention for removing an injector from an injection device. Fig. Figure 8A shows a perspective view of an embodiment of a test adapter according to the invention for testing the tightness of an injection device. Fig. 8B shows a partial sectional view of the area in the Fig. 8A test adapter shown. Fig. Figure 9 illustrates the use of a device according to the invention for checking the tightness of an injection device with an injector. Character description

[0027] Fig. Figure 1A shows a schematic view of a motor vehicle 50 with an internal combustion engine 52, in particular with a diesel engine, and with an exhaust aftertreatment system 54 designed for aftertreatment of the exhaust gases 56 of the internal combustion engine 52.

[0028] The exhaust aftertreatment system 54 comprises a catalyst 60, which is arranged in an exhaust stream 58 of the internal combustion engine 52, and a system 62 for injecting a fluid reducing agent 66, in particular an aqueous urea solution (“AdBlue”®), stored in a reservoir 64, into the exhaust stream 58 of the internal combustion engine 52.

[0029] During operation of the exhaust aftertreatment system 52, fluid reducing agent 66 is taken from the reservoir 64 via a supply line 68 and supplied under increased pressure via a suitable fluid line 74 to a metering module 55, which is arranged on the exhaust stream 58 of the internal combustion engine 52, by a fluid conveying device 70 which contains a fluid pump 72.

[0030] The metering module 55 comprises an injection device 90 with an injector 92, which is designed and configured to inject the fluid reducing agent 66 as a spray 76 into the exhaust stream 58 of the internal combustion engine 52.

[0031] In the exhaust stream 58, the injected reducing agent 66 mixes with the exhaust gases 56 of the combustion engine 52 flowing through the exhaust stream 58 and reacts in the catalyst 60 provided downstream of the metering module 55 in the exhaust stream 58 with the nitrogen oxides contained in the exhaust gases 56 to form water and nitrogen.

[0032] The injector 92 is a wear part that must be replaced when necessary to ensure proper operation of the exhaust aftertreatment system 52 and to comply with specified exhaust emission limits.

[0033] The exhaust aftertreatment system 52 comprises several sensors 82, 84, 86, for example temperature sensors 82, 84, which are arranged upstream and downstream of the catalyst 60 on or in the exhaust stream 58, and a nitrogen oxide sensor (“NOx sensor”) 86, which is arranged downstream of the catalyst 60 in the exhaust stream 58.

[0034] The sensors 82, 84, 86 deliver measurement results to a control unit 80, which is designed to control the components of the exhaust aftertreatment system 52, in particular the fluid delivery device 70 and the injector 92, in such a way that the nitrogen oxides contained in the exhaust gases 56 of the combustion engine 52 are reduced to nitrogen and water in the best possible way.

[0035] Fig. Figure 1B shows an exploded view of an injection device 90 with an injector 92 arranged in a cooling element 2 of the injection device 90. The injector 92 is fixed in the cooling element 2 by means of screws 95 through a retaining plate 94 and a valve holder 4.

[0036] Fluid connection elements 96 are screwed into the cooling body 2 and sealed by sealing rings 97.

[0037] A heat shield 98 is also provided on the cooling body 2 to protect the injector 92 from heat emitted by the exhaust system 58.

[0038] Fig. Figure 2 shows an injection device 90 removed from a motor vehicle 50, with an injector 92 arranged in the cooling element 2 and held by the valve holder 4, as described in connection with the Fig. 1B has been described.

[0039] The heat sink 2 is attached to an adapter plate 6 by means of fastening elements 5, for example with screws 5. The adapter plate 6 is clamped between the jaws 8 of a vise.

[0040] Fig. Figure 3 shows a top view of an adapter plate 6, which is designed according to an embodiment of the invention.

[0041] The adapter plate 6 is rectangular, in particular square, with a side length L in the range between 65 mm and 80 mm, in particular with a side length of 70 mm.

[0042] The adapter plate 6 has three mounting holes 10, which allow fastening elements / screws 5 to be passed through the adapter plate 6 in order to attach an injection device 90 to the adapter plate 6, as shown in the Fig. 2 is shown.

[0043] In the Fig. In the embodiment shown in Figure 3, the fastening holes 10 are designed with M6 internal threads, which make it possible to screw the fastening elements / screws 5 into the fastening holes 10.

[0044] The positions and diameters of the mounting holes 10 are matched to the mounting elements 5 and mounting tabs formed on the injection device 90. In further embodiments not explicitly shown in the figures, the mounting holes 10 may be configured differently than shown in the Fig. Figure 3 shows that the mounting holes 10 are designed in such a way as to correspond with the mounting tabs of the heat sink 2.

[0045] Furthermore, the adapter plate 6 has a screw-in opening 12, which makes it possible to attach a (in the Fig. 3 screw-in adapters 14 (not shown) are to be guided through the adapter plate 6. The screw-in opening 12 is designed in particular with an internal thread, for example with an M18x1.5 internal thread, which makes it possible to screw in a screw-in adapter 14, which is designed with a corresponding external thread, into the screw-in opening 12.

[0046] The screw-in opening 12 is positioned in the adapter plate 6 such that it is arranged in the extension of an injector channel formed in the cooling body 2 in which the injector 92 is arranged.

[0047] The screw-in opening 12 is designed in particular to be aligned coaxially with the injector channel.

[0048] Fig. Figure 4A shows a perspective view of a screw-in adapter 14, which is designed according to an embodiment of the invention. Fig. 4B shows a sectional view of the [unclear text] in the Fig. 4A screw-in adapter 14.

[0049] The screw-in adapter 14 has a first cylindrical area (“screw-in area”) 14a and a second cylindrical area (“grip area”) 14b. The screw-in area 14a and the grip area 14b are coaxial with each other along a common axis A.

[0050] The screw-in area 14a has a first diameter D1 and the handle area 14b has a second diameter D2, which is larger than the first diameter D1.

[0051] The screw-in area 14a can, for example, have a first diameter D1 in the range between 15 mm and 16.5 mm. Specifically, the screw-in area 14a can have a first diameter D1 of 16.2 mm.

[0052] The grip area 14b, for example, can have a second diameter D2 in the range between 29 mm and 31 mm.

[0053] The screw-in area 14a can, for example, have a first length L1 in the range between 17 mm and 19 mm, in particular a first length L1 of 18 mm.

[0054] The grip area 14b, for example, can have a second length L2 in the range between 15 mm and 17 mm, in particular a second length L2 of 16 mm.

[0055] The dimensions of the screw-in adapter 14 mentioned here are only exemplary and may vary depending on the dimensions of the heat sink 2 and the injector 92 when a device according to the invention is used for disassembling other dosing module variants. The first diameter D1 of the screw-in area 14a is selected in particular such that the screw-in area 14a can be inserted into the screw-in opening 12 formed in the adapter plate 6.

[0056] An external thread 16 is formed on the outer circumference of the screw-in area 14a, which can be screwed into the internal thread formed in the screw-in opening 12 of the adapter plate 6.

[0057] A knurling is formed on the outer circumference of the grip area 14b to facilitate the handling, in particular the screwing in, of the screw-in adapter 14.

[0058] The screw-in adapter 14 has an axial bore 18 which extends along the axis A of the screw-in adapter 14 through the screw-in area 14a and the grip area 14b.

[0059] The axial bore 18 is formed with an internal thread, in particular with an M10 internal thread. In alternative embodiments, which are not explicitly shown in the figures, the axial bore 18 can also be formed with a larger or smaller diameter and with a larger or smaller internal thread.

[0060] Fig. Figure 5A shows a view of a mandrel 20 which can be screwed into the axial bore 18 formed in the screw-in adapter 14 in order to push the injector 92 out of the heat sink 2.

[0061] The mandrel 20 has a first cylindrical area 20a and a second cylindrical area 20b, which are formed coaxially to each other along a common axis B.

[0062] The first cylindrical region 20a has a first diameter d1 and a first length l1. The second cylindrical region 20b has a second diameter d2 and a second length l2.

[0063] The first diameter d1 is smaller than the second diameter d2 and the first length l1 is shorter than the second length l2.

[0064] The first area 1420a can, for example, have a first diameter d1 in the range between 4.6 mm and 4.8 mm, in particular a first diameter d1 of 4.7 mm.

[0065] The second area 20b can be formed with an M10 external thread so that it can be screwed into an M10 internal thread formed in the axial bore 18 of the screw-in adapter 14.

[0066] The second area 20b and the axial bore 18 of the screw-in adapter 14 can also be designed with other corresponding threads.

[0067] The first cylindrical area 20a can have a first length l1 in the range between 18 mm and 20 mm, in particular a first length l1 of 19 mm or of 19.5 mm.

[0068] The second cylindrical area 20b can have a second length l2 in the range between 44 and 50 mm, in particular a second length l2 in the range between 45 and 47 mm.

[0069] The dimensions of the first cylindrical area 20a and the second cylindrical area 20b given are only examples and may vary. In particular, the dimensions may vary depending on the thickness of the adapter plate 6, the geometry of the heat sink 2, and / or the geometry of the injector 92 if the device is to be used for disassembling a different type of metering module.

[0070] Between the first cylindrical region 20a and the second cylindrical region 20b, a chamfered or conical region 20c is formed, which tapers from the second diameter d2 of the second cylindrical region 20b to the first diameter D1 of the first cylindrical region 20a. The chamfered or conical region 20c can be chamfered with respect to the axis B at an angle α in the range between 40° and 50°, in particular at an angle α of 45°.

[0071] A screw-in head 22 is formed at one end of the second cylindrical region 20b of the mandrel 20, the end facing away from the first cylindrical region 20a. The screw-in head 22 can, for example, have a diameter d0 in the range between 14 mm and 18 mm, in particular a diameter d0 of 16 mm.

[0072] Fig. Figure 5B shows a top view of the screw-in head 22.

[0073] A hexagonal opening 24 is formed in an end face of the screw-in head 22 facing away from the second cylindrical area 20b of the mandrel 20.

[0074] The hexagonal opening 24 makes it possible to insert a hexagonal tool 26, in particular a hexagonal key, into the screw-in head 22 (see Fig. 7) to rotate the print mandrel 20 about its axis A, in particular to screw the print mandrel 20 into the axial bore 18 formed in the screw-in adapter 14.

[0075] Fig. Figure 6A shows a perspective view of a device 30 for removing and testing an injector 92 according to an embodiment of the invention. Fig. 6B shows a cross-section through the Fig. Device 30 shown in 6A.

[0076] The device 30 comprises the adapter plate 6, the screw-in adapter 14, which is screwed into the screw-in opening 12 in the adapter plate 6, and the ejector mandrel 20, which is screwed into the axial bore 18 formed in the screw-in adapter 14.

[0077] The Fig. 6A and Fig. Figure 6B also shows the fastening elements 5, e.g. screws 5, which are screwed into the fastening holes 10 in the adapter plate 6.

[0078] Fig. Figure 7 illustrates the use of a device 30 according to the invention, which comprises the adapter plate 6, the screw-in adapter 14 and the ejector mandrel 20, to remove an injector 92 from an injection device 90.

[0079] A cooling element 2 of the injection device 90 is, as already mentioned in the Fig. 2 shown, with fasteners / screws 5, which are in the Fig. 7 are not visible, attached to the adapter plate 6. The adapter plate 6 is clamped between the two jaws 8 of a vise.

[0080] The screw-in adapter 14 is screwed into the screw-in opening 12 formed in the adapter plate 6 from the side facing away from the injection device 90, so that in the Fig. 7 only the grip area 14b of the screw-in adapter 14 is visible outside the adapter plate 6.

[0081] The print mandrel 20 is partially screwed into the axial bore 18 formed in the screw-in adapter 14, so that in particular a part of the second cylindrical area 20b of the print mandrel 20 is still visible.

[0082] Using a suitable hexagonal tool 26, which is inserted into the hexagonal opening 24 formed in the screw-in head 22, the mandrel 20 can be screwed even deeper into the axial bore 18 of the screw-in adapter 14 and thus through the adapter plate 6 into the injector channel formed inside the cooling body 2.

[0083] When the front end of the first cylindrical section 20a of the ejector mandrel 20 reaches the injector 92, further screwing in of the ejector mandrel 20 causes the front end of the ejector mandrel 20 to push the injector 92 out of the cooling sink 2, after the screws 95 of the valve holder 4 (see Fig. 1 B) have been resolved. In this way, the injector 92 can be safely and non-destructively removed from the cooling element 2 without damaging the injection device 90.

[0084] After the injector 92 has been removed from the cooling element 2, the components of the injection device 90, in particular the injector channel in the cooling element 2, can be cleaned. A new injector 92 can then be inserted into the cooling element 2 of the injection device 90.

[0085] After a new injector 92 has been installed in the injection device 90 and fixed there, a leak test must be carried out to check the injection device 90 with the new injector 92 for leaks.

[0086] One way to check the tightness of the injection device 90 with the new injector 92 is to submerge the injection device 90 in water and, in a so-called "bubble test", introduce a gas, in particular air, under pressure into the injection device 90 to check whether the supplied gas escapes from the injection device 90 in the form of bubbles that are visible in the water.

[0087] In order to be able to perform such a bubble test, a device 30 according to the invention can additionally include a test adapter 32 which makes it possible to introduce a gas, in particular air, into the injection device 90.

[0088] Fig. Figure 8A shows a perspective view of an embodiment of such a test adapter 32, and Fig. Figure 8B shows a sectional view of the test adapter 32.

[0089] The test adapter 32 includes a [unclear] in the Fig. 8A and Fig. 8B shown on the left is the screw-in element 34 with an external thread 35 formed on its outer circumference. The screw-in element 34 can be screwed into the screw-in opening 12 formed in the adapter plate 6, just like the screw-in adapter 14 described above.

[0090] A lock nut 36 is provided on the external thread 35, which makes it possible to secure the screw-in element 34 in the screw-in opening 12.

[0091] At the one in the Fig. 8A and Fig. 8B at the left end of the screw-in element 34, a rubber seal 38 is provided to seal the interface between the screw-in element 34 and the injector 92 in a gas-tight manner.

[0092] On the opposite side, into the Fig. 8A and Fig. 8B, shown on the right, at the end of the screw-in element 34 there is a coupling plug 40 with a connection area 42, which is designed and intended to be connected to an air supply line, in particular an air hose 44, which is inserted into the Fig. 8A and Fig. 8B is not shown, to be connected in order to supply air to the injection device 90.

[0093] On the end of the coupling plug 40 facing away from the connection area 42, which is located in the Fig. As shown in Figure 8B on the left, an external thread 46 is formed which is screwed into a corresponding internal thread formed in the screw-in element 34 in order to securely connect the coupling plug 40 and the screw-in element 34. A sealing ring 48 is provided between the coupling plug 40 and the screw-in element 34 to create a gas-tight seal between the coupling plug 40 and the screw-in element 34.

[0094] Fig. Figure 9 illustrates the use according to the invention of a device according to the invention for checking the tightness of the injection device 90 with an injector 92 arranged therein.

[0095] The injection device 90, which contains the injector 92, is attached to the adapter plate 6 by means of fastening elements 5, as shown in the Fig. 2 and Fig. 7 is shown.

[0096] The screw-in element 34 of the test adapter 32 is screwed into the screw-in opening 12 formed in the adapter plate 6 and secured with the lock nut 36.

[0097] An air hose 44 is attached to the connection area 42 of the coupling plug 40 and secured with a hose clamp 46.

[0098] To check the tightness of the injection device 90 with the injector 92, the [unclear] is [unclear] Fig.The arrangement shown in 9 is placed in a water container below the water surface. Then, pressurized gas, in particular air, is introduced into the injector channel of the injection device 90 through the air hose 44 and the test adapter 32.

[0099] The water surrounding the injection device 90 is then checked to see if gas bubbles rise ("bubble test"). The presence of gas bubbles would indicate that the injection device 90 is leaking.

[0100] If no gas bubbles rise from the injection device 90, the leak test has been passed.

[0101] A device 30 according to the invention enables both a simple, non-destructive and damage-free removal of an injector 92 from an injection device 90 and a simple, convenient and reliable checking of the tightness of one of the injection devices 90 with a bubble test, in particular after a new injector 92 has been installed in the injection device 90.

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