Penetration through a housing component, especially for harsh, mechanically and thermally stressed environments

Description

[0001] The invention relates to a feedthrough through a housing component, in particular for harsh, mechanically and thermally stressed environments.

[0002] If such feedthroughs, for example for the transmission of electrical or electronic signals, are located in sections of exhaust systems of internal combustion engines, for example in motor vehicles with controlled exhaust gas purification, significantly changing ambient conditions often occur.

[0003] DE 10 2011 101 676 B4, for example, describes a catalyst heating system for an internal combustion engine of a motor vehicle, which system has a monitoring module, a mode selection module and a control module for an electrically heatable catalyst (EHC), wherein the mode selection module is configured to select an EHC heating mode based on a first temperature and / or the active catalyst volume and to generate a mode signal on the basis of which the EHC control module supplies a current to an electrically heatable catalyst (EHC) of the catalyst arrangement, which current causes it to heat up.

[0004] Such systems can utilize high currents, ranging from 20 A to 100 A, for example, to provide particularly high heating outputs, typically in the range of 1 kW to approximately 8 kW. The high heating outputs are intended to rapidly heat the electrically heated catalyst (EHC) to keep the cold start or cold run phase as short as possible.

[0005] These currents are conducted into the interior of the catalyst by means of electrical feedthroughs, whereby these feedthroughs usually have an inner conductor which is held by means of an electrically insulating material within an outer conductor assigned to it, which in turn is attached to the housing of the respective catalyst in an electrically conductive connection to its housing.

[0006] Document DE 10 2008 045 816 A1 proposes an elastomeric material surrounding a conductor for a feedthrough in order to extend a creepage distance, which, in the context of this disclosure, is the distance along which creepage currents can develop between the joining partners. A disadvantage of this solution is that elastomeric materials often do not have the thermal stability and long-term operating strength required for the hot area of ​​exhaust systems, because temperatures of up to more than 900°C can occur inside these catalysts, thus creating a very high temperature gradient compared to the exterior of the catalyst.

[0007] In the case of bushings on exhaust gas catalytic converters or turbochargers of internal combustion engines, temperature gradients can occur between the outer conductor and the inner conductor of the bushing, which can each amount to several 100 K.

[0008] In addition, exhaust gas systems are exposed to severe temperature changes, for example during the transition from the cold start or cold running phase to a desired continuous operating state or when the respective internal combustion engine is switched off, which leads to the creation of thermally induced stresses, especially when the respective exhaust element cools down inhomogeneously.

[0009] EP 3 650 415 A1 by the same applicant describes a joint comprising a crystallized glass that holds an inner conductor relative to an outer conductor, which can be used as an electrical feedthrough in an element of an exhaust system. However, no details regarding the assembly or mechanical support of this joint are disclosed.

[0010] The feedthroughs discussed above are also exposed to harsh environments in other respects, because inside a catalyst, especially an electrically heated catalyst, corrosive exhaust gases act on the feedthrough and in outer areas of the catalyst, salt water or mechanically aggressive particles often come into contact with it.

[0011] High mechanical stresses also often occur due to vibrations, which can correspond to accelerations of up to significantly more than 10 g. The resulting forces can be transmitted through the way the bushing is attached to the catalytic converter into the outer conductor, which holds the pin of the inner conductor, which often leads to heating elements located inside the catalytic converter. This conductor is thus subjected to further, additional mechanical stresses in the exhaust stream by these heating elements. For example, the pulsating exhaust stream itself can generate frequency spectra, which can induce undesirable movements in the bushing if it is elastically, particularly if it is subject to vibration.

[0012] WO 2018 / 114392 A2 by the same applicant proposes a feedthrough for a battery or capacitor housing, preferably for a supercapacitor housing, comprising a base body. The base body is provided with at least one opening that holds at least one functional element in a glass or glass-ceramic material and is intended for connection to a housing made of a light metal, in particular aluminum, wherein the base body consists at least partially of a light metal, preferably a light metal alloy. However, batteries, capacitors, and especially supercapacitors, generally do not encounter the harsh environmental conditions described above, but must even regularly avoid greatly elevated temperatures due to the chemical substances used in them.Where batteries are used in the drive technology of motor vehicles, increased attention must be paid to their temperature management, in particular to ensure that no fire or explosion-hazardous operating conditions are reached, which could then endanger the life and limb of the vehicle occupants.

[0013] However, even without the aforementioned stresses during operation of an internal combustion engine, there is already a risk of pre-damage to the bushing, for example, during its installation on a catalytic converter housing component. If, for example, the outer conductor of the bushing is welded to the catalytic converter housing component, the locally high temperatures and resulting stresses can damage the temperature-stable, preferably mineral material that holds the inner conductor, even without this damage being immediately apparent. However, such pre-damage can significantly reduce the long-term operational strength of the bushings discussed here.

[0014] Further implementations are known from the following publications: EP 0 830 695 B1, DE 195 33 088 A1, US 6 628 024 B1), EP 0 942 158 B1, WO 2018 / 114392 A2 or DE 34 18 156 A1.

[0015] The invention is based on the object of at least mitigating the disadvantages described above. In particular, it is advantageous to be able to ensure the integrity of a bushing with greater certainty than before, even during installation.

[0016] In addition, a mechanically robust installation of a bushing, especially in the exhaust system of an internal combustion engine, is advantageous for its long-term operational strength.

[0017] The inventors have surprisingly discovered that even with high-temperature-resistant bushings, pre-damage can occur during assembly, for example by means of laser or tungsten inert gas welding (TIG), which is not always immediately recognizable but can significantly reduce the long-term operational strength of these high-temperature-resistant bushings.

[0018] The above problem can already be solved with the features of independent claim 1 and such pre-damage can be significantly reduced.

[0019] According to the invention, it is provided that a feedthrough through a housing component, in particular for harsh, mechanically and thermally stressed environments, an inner conductor, an outer conductor, and an electrically insulating component arranged between the outer conductor and the inner conductor, wherein the electrically insulating component arranged between the outer conductor and the inner conductor preferably comprises a glass, in particular a crystallizable or at least partially crystallized glass, or a glass ceramic, and the electrically insulating component keeps the inner conductor electrically insulated relative to the outer conductor. In a further embodiment, a sleeve is assigned to the outer conductor or formed thereon, by means of which sleeve it can be held or fastened to a thermally loaded housing component, in particular to a functional assembly of the exhaust system of a motor vehicle.

[0020] Thermally stressed environments are considered to be environments in which recurring temperature differences of more than 200 K can occur in the operating state of the thermally stressed housing component, as is regularly the case in exhaust systems of internal combustion engines.

[0021] Harsh, mechanically and thermally stressed environments are considered to be environments in which, in addition to the recurring temperature differences described above, mechanical stresses such as vibrations are added, which exert acceleration forces of at least 10 g on the bushing, i.e. ten times the acceleration acting in the Earth's gravitational field.

[0022] For the purposes of the present disclosure, a feedthrough is considered to be "fastenable" if it is suitable and intended to be fastened to another assembly, for example by means of a mounting area provided for this fastening on a sleeve formed by the feedthrough or associated with the feedthrough.

[0023] Held by means of an electrically insulating component or held in an electrically insulated manner in the context of the present disclosure refers to a type of holding in which a direct current resistance between the joining partners of the feedthrough described here, which are located in a dry atmosphere, thus between the inner conductor and the outer conductor of the feedthrough, on which there are no deposits which can impair this resistance, is more than 100 MOhm, these electrical resistance values ​​being measured at voltages of less than 100 V.

[0024] The invention enables assembly or fastening by welding processes of the insulating component, in particular of the glazing frequently provided by this component, without damage, for example due to inhomogeneous mechanical stress distribution during a welding process.

[0025] This advantageously results in a decoupling of the glazing of the insulating component, which usually has a high modulus of elasticity and is less elastic than metals of the inner or outer conductor, from deformation of the outer conductor during the application of the welding process.

[0026] In addition, damping of the deflection of the inner conductor, designed as a pin, relative to the outer conductor can be provided against vibration occurring during operation, which is described in more detail below.

[0027] The provision of a sleeve allows the use of adapted wall thicknesses, which can be thicker for the outer conductor surrounding the insulating component and thinner for assembly areas located on the sleeve, especially welding areas. Overall, the inner conductor can respond more elastically to mechanical stresses.

[0028] In a first preferred variant, the outer conductor is formed integrally with the sleeve. For the purposes of the present disclosure, embodiments in which the outer conductor is formed integrally with the sleeve are also referred to simply as "integral embodiments."

[0029] Further embodiments have an at least two-piece design, in which different materials can advantageously be used for the outer conductor and the sleeve. In this case, by specifically adjusting the elasticity of the sleeve, in particular by appropriately selecting the material as well as the wall thickness and the axial extent of the sleeve, thermal expansion differences between the feedthrough and the component to which it is attached can be absorbed without damaging, thermally induced stress differences occurring. In this case, it can be particularly advantageous to adapt the thermal expansion of the outer conductor to that of the glass-ceramic insulation. This is advantageous in the case of thermal cycling that occurs in application, as it minimizes stresses in the glass-ceramic insulation material.

[0030] Furthermore, in some cases it is advantageous to match the material of the sleeve, independent of the outer conductor, to the welding partner to which the bushing is attached in order to optimize this process.

[0031] In the context of the present disclosure, embodiments in which the outer conductor and the sleeve are present in two pieces are also referred to simply as "two-piece embodiments", even if the sleeve is mechanically firmly held on the outer conductor after its assembly, for example by means of a first assembly region.

[0032] A hermetically sealed connection can be realized by welding or soldering, which enables cost-effective series production, particularly through non-cutting, i.e. non-machining, manufacturing.

[0033] Preferably, the inner conductor is cylindrically symmetrical, in particular cylindrical, and the outer conductor surrounds the inner conductor in a cylindrically symmetrical, in particular annular arrangement, since this results in a compact and mechanically stable design.

[0034] In a two-piece design, the sleeve can advantageously surround the outer conductor on its outer surface and have at least two mounting areas that are spatially spaced from one another.

[0035] In this case, a first mounting area can provide a mechanical connection of the sleeve to the outer conductor and a second mounting area can provide a mechanical connection of the sleeve to the housing component of the functional assembly of the exhaust system of a motor vehicle, on which the bushing is held after its mounting.

[0036] It is particularly advantageous that different fastening forms can be selected for the first mounting area than for the second mounting area, as will be described in more detail below with reference to various embodiments with their fastening or mounting options.

[0037] According to the invention, after mounting the sleeve on the outer conductor of the bushing, a gap is formed between the outer surface of the outer conductor and an inner surface of the sleeve. This allows for very effective heat dissipation during assembly, for example, using laser or TIG welding. When the bushing is mounted, a gap exists that allows elastic deflections of the bushing without mechanical contact and the resulting damage. This design also allows force peaks, which are introduced, for example, into the inner conductor designed as a pin, to be effectively absorbed without mechanical damage.

[0038] Such a design of the sleeve allows a relatively free choice with regard to the axial width of the fastening areas and, moreover, several fastening lines one above the other are also possible, for example in order to provide a defined mechanical strength and a reduced tendency to oscillate, in particular resonant oscillation.

[0039] If the sleeve has a radially narrowed section in the region of the first mounting section, this can have several advantages, for example if this narrowed mounting section provides a press fit for the outer surface of the outer conductor and this can already hold the outer conductor securely and permanently relative to the sleeve.

[0040] Furthermore, such a close fit of the sleeve to the outer surface of the outer conductor also enables resistance and friction welding to hold the sleeve to the outer conductor in such a way that it is resistant to continuous operation.

[0041] In addition, laser and TIG welding is also made more precise, as corresponding weld seams can then be carried out more safely and a hermetically sealed connection between the sleeve and the outer conductor can then be created with greater reliability.

[0042] The friction effect provided by the radially narrowed section of the sleeve with respect to the outer surface of the outer conductor can also act as a damping element, for example against torsional, tilting and longitudinal vibrations of the outer conductor relative to the sleeve held in a device component.

[0043] Thus, the first mounting area, which provides a mechanical connection of the outer conductor to the sleeve, can be formed in the mounted state by a press fit or by local mechanical pressing, in particular by point-shaped or regional depressions of the sleeve in the radially inward direction.

[0044] It is advantageous if the thermal expansion coefficient of the outer conductor material is equal to, or at least only slightly higher than, the thermal expansion coefficient of the sleeve material within the respective operating temperature range. This prevents heating of the bushing from generating forces that attempt to separate the sleeve from the outer conductor. Instead, additional forces are introduced into the bushing, making the mechanical connection between the outer conductor and the bushing more stable. A difference in thermal expansion, i.e., the respective thermal expansion coefficients, of less than 3 ppm / K is advantageous, and particularly advantageously less than 1.5 ppm / K.

[0045] Advantageously, in the aforementioned two-piece design, the first mounting area is formed on the inner surface of the sleeve and the second mounting area is formed on an outer circumferential surface of the sleeve, and in the one-piece design, the at least one mounting area is formed on the outer circumferential surface of the sleeve. This arrangement of the second or at least one mounting area ensures that potentially strong local temperature peaks that arise during assembly only lead to a very limited heating of the outer conductor and, even if it does heat up, only affect locally greatly enlarged areas, so that only significantly lower thermally induced stresses arise between the outer conductor and the insulating component.

[0046] This can be the case in particular if the second assembly area, which provides a mechanical connection to the housing component of the functional assembly of the exhaust system of a motor vehicle, is then connected in the assembled state to the housing component of the functional assembly of the exhaust system of a motor vehicle by a soldered connection or a welded connection, in particular a laser or TIG welded connection or by resistance welding.

[0047] Advantageously, in two-piece embodiments, the first mounting area, which provides a mechanical connection of the outer conductor to the sleeve, can be formed in the mounted state by a soldered connection or a welded connection, in particular a resistance, friction welded, laser or TIG welded connection or by friction welding, because in this case too, heat can be dissipated through the sleeve and heat acting on the outer conductor can be distributed more locally.

[0048] If the second mounting area in two-piece embodiments is arranged radially and / or axially offset relative to the first mounting area or if the at least one mounting area in one-piece embodiments is arranged radially and / or axially offset relative to the area in which the outer conductor merges into the sleeve, heat-conducting transitions between the sleeve and the outer conductor can be further influenced in a defined manner by the radial or axial offset.

[0049] In general, a fastening arranged on the first mounting area can be designed to be radially circumferential and a ring-shaped closed fastening line formed on the first mounting area can be arranged offset to the lower and upper radial end of the sleeve and, in particular, can have a damping effect on torsional, tilting and longitudinal vibrations due to its position in the axial direction, for example if this fastening line suppresses a possible vibration antinode.

[0050] For this purpose, the second mounting area formed on an outer circumferential surface of the sleeve or the at least one mounting area can also be formed circumferentially and an annular closed fastening line formed on the second mounting area can be arranged offset to the lower and upper radial end of the sleeve.

[0051] The bushing described here can advantageously be attached to a functional assembly of a motor vehicle, such as an exhaust gas catalyst, in particular an electrically heatable exhaust gas catalyst (EHC) or also to an exhaust gas catalyst having sensors.

[0052] Alternatively or additionally, the bushing described here can also be held in a continuously operational manner on a turbocharger, in particular a turbocharger provided with an electric drive or a turbocharger having sensors.

[0053] Furthermore, the thermally stressed housing component to which the bushing is held can also be part of a chemical production plant.

[0054] The invention is described in more detail below using preferred embodiments and with reference to the accompanying drawings.

[0055] They show: Figure 1 shows a cross-sectional view of a first preferred embodiment of a bushing which is held on a thermally loaded housing component, in particular a functional assembly of the exhaust system of a motor vehicle, wherein the cross-sectional plane runs in the horizontal direction approximately through the line of symmetry of the bushing. Figure 2 shows a cross-sectional view of a second preferred embodiment of a bushing which is held on a thermally loaded housing component, in particular a functional assembly of the exhaust system of a motor vehicle, wherein the cross-sectional plane runs in the horizontal direction approximately through the line of symmetry of the bushing. Figure 3 shows a cross-sectional view of an embodiment of a bushing not according to the invention which is held on a thermally loaded housing component, in particular a functional assembly of the exhaust system of a motor vehicle.where the cross-sectional plane runs in the horizontal direction approximately through the line of symmetry of the bushing, Figure 4 is a cross-sectional view of the in , Figure 3 shown feedthrough, in which temperatures are shown, as they can occur during laser welding or TIG welding for connecting the feedthrough with a functional assembly of the exhaust system of a motor vehicle, Figure 5 a plan view of a 3D representation diagonally from above, in which the temperatures occurring during laser welding or TIG welding for the Figure 1illustrated embodiment during its assembly on a functional assembly of the exhaust system of a motor vehicle, Figure 6 is a cross-sectional view of the first preferred embodiment of a bushing which is held on a thermally loaded housing component, in particular a functional assembly of the exhaust system of a motor vehicle, wherein the cross-sectional plane runs in the horizontal direction approximately through the line of symmetry of the bushing and the temperatures occurring during laser welding or TIG welding during its assembly on a functional assembly of the exhaust system of a motor vehicle are shown, Figure 7 is a cross-sectional view of the in Figure 2shown second preferred embodiment of a bushing, in which a weight is attached to the inner conductor by means of which vibration stresses can be introduced into the bushing, wherein the cross-sectional plane runs in the horizontal direction approximately through the line of symmetry of the bushing, Figure 8 a cross-sectional representation of a simulated vibration load of the in Figure 2 shown second preferred embodiment, in which as in Figure 7 shown a weight is attached to the inner conductor by means of which vibration voltages can be introduced into the bushing together with the results of the vibration load, Figure 9 an enlarged detail view from Figure 8in the area of ​​the transition from the outer conductor to the sleeve, Figure 10 a cross-sectional view of a third preferred embodiment of a bushing, which is held on a thermally loaded housing component, in particular a functional assembly of the exhaust system of a motor vehicle, wherein the cross-sectional plane runs in the horizontal direction approximately through the line of symmetry of the bushing, Figure 11 a cross-sectional view of a detail of the in Figure 10shown feedthrough, in which temperatures are shown such as can occur during laser welding or TIG welding for connecting the feedthrough to a functional assembly of the exhaust system of a motor vehicle, Figure 12 shows a cross-sectional view of the outer conductor and the sleeve of a fourth preferred embodiment with a projecting base region of the sleeve, in which the sleeve is held to the outer conductor by means of laser welding or a soldered connection, wherein the cross-sectional plane runs in the horizontal direction approximately through the line of symmetry of the feedthrough, Figure 13 shows a cross-sectional view of the outer conductor and the sleeve of a fifth preferred embodiment with a radially narrowed section in the region of the first mounting section of the sleeve, in which the sleeve is held to the outer conductor by means of laser welding or a soldered connection,Figure 14 shows a cross-sectional view of the outer conductor and the sleeve of a sixth preferred embodiment with a projecting base section and a radially narrowed section in the region of the first mounting section of the sleeve, in which the sleeve is held on the outer conductor by means of laser welding. Figure 15 shows a cross-sectional view of the outer conductor and the sleeve of a seventh preferred embodiment with a projecting base section and a radially narrowed section in the region of the first mounting section of the sleeve, in which the sleeve is held on the outer conductor by means of a soldered connection. Figure 16 shows a cross-sectional view of the outer conductor and the sleeve of an eighth preferred embodiment with a radially narrowed section in the region of the first mounting section of the sleeve, in which the sleeve is held on the outer conductor by means of a press fit and / or by mechanical pressing.in particular by point-shaped or regional depressions of the sleeve in the radially inward direction on the outer conductor, Figure 17 a cross-sectional view of the outer conductor and the sleeve of a ninth preferred embodiment with a radially narrowed section in the region of the first assembly section of the sleeve, in which the sleeve is held on the outer conductor by means of point-shaped welds. Detailed description

[0056] In the following detailed description, like reference numerals designate like or equivalent components in the various disclosed embodiments. For the sake of clarity, not all illustrations are drawn to scale.

[0057] The following refers to Figure 1which shows a cross-sectional view of a first preferred embodiment of a feedthrough, generally designated by reference numeral 1, through a housing component 2, said cross-sectional view extending in the horizontal direction approximately through the line of symmetry S of the feedthrough 1.

[0058] The housing component 2 can be part of a thermally loaded assembly, in particular a functional assembly of the exhaust system of a motor vehicle, such as an exhaust gas catalytic converter, in particular an electrically heatable exhaust gas catalytic converter (EHC) or an exhaust gas catalytic converter having sensors, or can also be part of a turbocharger, in particular a turbocharger provided with an electric drive or a turbocharger having sensors.

[0059] Alternatively, in further embodiments, the thermally stressed housing component 2 can also be part of a chemical production plant in order, for example, to conduct electrical signals to or from sensors or actuators through the housing component 2 by means of the feedthrough 1.

[0060] The bushing 1 generally comprises an inner conductor 3, an outer conductor 4 and an electrically insulating component 5 arranged between the outer conductor 4 and the inner conductor 3.

[0061] The electrically insulating component 5 can comprise a glass, in particular a crystallizable or at least partially crystallized glass, or also a glass ceramic, and mechanically holds the inner conductor 3 relative to the outer conductor 4, electrically insulated from the latter, in particular sufficiently resistant to pull-out and vibration for the respective application, which is ensured by its respective structural dimensions and choice of material in an application-specific manner.

[0062] During manufacture of the bushing 1, the electrically insulating component 5 can be heated, at least in part, to its molten state, while it is already arranged between the likewise heated inner conductor 3 and the heated outer conductor 4 essentially in its later operating position. At this elevated temperature, both the outer surface of the inner conductor 3 and the inner surface of the outer conductor 4 are wetted, which is also referred to as glazing. Cooling of the inner conductor 3, the electrically insulating component 5, and the outer conductor 4 following wetting leads to a mechanically stable connection between the inner conductor 3 and the insulating component 5, as well as between the insulating component 5 and the outer conductor 4, which is also referred to as glazing.If the outer conductor 4 has a higher thermal expansion coefficient than the insulating component 5 and the pin, compressive stresses arise during cooling, which the outer conductor 4 exerts on the insulating component 5, leading to an increase in the strength of the bushing 1 and, in particular, also increasing the pull-out strength of the inner conductor 3. In this case, the resulting glazing is also referred to as pressure glazing.

[0063] In general, the inner conductor 3 is cylindrically symmetrical, in particular cylindrical, for example designed as a cylindrical pin, wherein the inner conductor 3 can also be columnar in further embodiments with a cross-section deviating from cylindrical symmetry, and the outer conductor 4 surrounds the inner conductor 3 cylindrically symmetrically, and is in particular ring-shaped or tubular.

[0064] A sleeve 6 is assigned to the outer conductor 4 or is formed on the outer conductor 4 itself, by means of which the outer conductor 4 and thereby the bushing 1 can be held on the housing component 2 or fastened to the housing component 2.

[0065] In the in the Figures 2 , 5 , 6 , 7 , 8 and 9 In the embodiments shown, the sleeve 6 is essentially cylindrical and has at its lower end a radially inwardly extending bridge section 7 which connects it in one piece to the outer conductor 4.

[0066] In the Figures 10 and 11 In the embodiments shown, the sleeve 6 extends in a frustoconical shape from the upper part of the outer conductor 4, widening radially downwards, away from it, but is also formed integrally with it.

[0067] In these one-piece embodiments described above, both the outer conductor 4 and the sleeve 6 are made of the same material, for example of metal, in particular iron, an iron alloy, an iron-chromium alloy, an iron-chromium-nickel alloy, an iron-nickel alloy, an iron-nickel alloy, an iron-nickel-cobalt alloy, KOVAR, titanium, a titanium alloy, in particular of a metal from the group of steels, for example normal steels, stainless steels, stainless steels and high-temperature stable ferritic steels, which are also known under the brand name Thermax, for example Thermax 4016, Thermax4742, or Thermax4762 or Crofer22 APU or CroFer22 H or NiFe-based materials, for example NiFe45, NiFe47 or known under the brand name Inconel, for example Inconel 718 or X-750, or steels, for example known under the designations CF25, Alloy 600, Alloy 625, Alloy 690, SUS310S, SUS430, SUH446 or SUS316,or austenitic steels such as 1.4828 or 1.4841, aluminum, an aluminum alloy, AlSIC, magnesium or even a magnesium alloy.

[0068] In these one-piece embodiments, in which the sleeve 6 is formed integrally with the outer conductor 4, the sleeve 6 has at least one annular mounting area 8, to which it is held by a laser or TIG weld when mounted on the housing component 2. An annular laser or TIG weld seam 9 extends along the mounting area 8 to a corresponding mounting area 10 formed on the housing assembly 2, thus connecting the sleeve 6 to the housing component 2.

[0069] As in the embodiments presented in more detail below, this advantageously enables fastening by welding without damaging the glazing of the insulating component 5 due to inhomogeneous stress distributions during the respective welding process.

[0070] During welding, there is a lower thermal load on the insulating component 5 and a decoupling of the entire glazing of the insulating component 5, which generally has a high modulus of elasticity and is less elastic than metals, in particular from deformations of the outer conductor relative to the insulating component 5.

[0071] This is particularly good compared to the conventional Figures 3 and 4illustrated embodiment, in which immediately after welding, very high temperatures Tmax of more than 950 °C, even up to 1019 °C in the case of TIG welding and more than 600 °C in the case of laser welding, occur directly in the area of ​​the welding point 11 of the conventional weld seam 12 in the areas of the inner wall of the outer conductor 4 adjacent to the welding point 11, which temperatures each have a locally limited effect on the insulating component 5.

[0072] These locally limited, very high temperatures are particularly harmful because they occur in the area of ​​the welding point 11, which, as can be seen from Figure 5As can be clearly seen, during welding the welding process is carried out in a circle around the outer conductor 4 and the housing component 2 at their respective contact lines, so that strong thermal and mechanical stresses occur between the outer conductor 4 and the insulating component 5 both during the heating caused by the welding and the subsequent cooling.

[0073] This can cause damage to bushing 1, which may not be immediately apparent after the welding process, but can significantly reduce the operational strength of this bushing. For example, microscopic cracks formed during the welding process can gradually spread, which can be further exacerbated by subsequent mechanical and thermal stresses on the bushing and, as a result, lead to the failure of the bushing, for example, due to an insufficiently held inner conductor 3.

[0074] However, significantly more advantageous conditions are made possible by the embodiments disclosed here, which are improved compared to the prior art and which, without limiting the generality, are initially only described with reference to the Figures 10 and 11 explained below, but can also be realized by the further embodiments disclosed herein.

[0075] The heat generated during the welding process at welding point 13 is initially not introduced into the outer conductor 4, but rather into the respective sleeve 6, from which it is then transferred to the outer conductor 4, albeit to a considerably lesser extent than with conventional bushings. Immediately after laser welding, which was carried out under the same conditions as the previously described laser welding of a conventional bushing, the maximum temperature Tmax of the outer conductor 4 was only approximately 100°C on the inner surface or inner face of the outer conductor 4 connected to the insulating component 5.

[0076] During TIG welding, which was also carried out under the same conditions as the TIG welding of a conventional bushing described above, these maximum temperatures Tmax on the inner surface or inner surface of the outer conductor 4 connected to the insulating component 5 were only about 139 °C.

[0077] In addition to the greatly reduced thermal stresses, mechanical stresses exerted by the outer conductor 4 on the insulating component 5 could also be greatly reduced, since these stresses could essentially already relax in the sleeve 6.

[0078] In contrast to mechanical stresses, which are caused by forces exerted by the outer conductor 4 on the insulating component 5, thermal stresses are understood to be those stresses which are generated by the respective temperature gradient in the respective component itself, i.e. in the outer conductor 4 and the insulating component 5 itself.

[0079] In a very advantageous manner, the damping of the deflection of the inner conductor 3, preferably designed as a cylindrical pin or pin, relative to the outer conductor 4 against vibrations could also be greatly improved, as will be explained below with reference to the Figures 8 and 9 described in more detail.

[0080] The one in the Figures 3 and 4The vibrations introduced into the inner conductor 3 through the conventional feedthrough shown act through the inner conductor 3 directly onto the insulating component 5 and via the insulating component 5 directly onto the outer conductor 4. If, for example, further components are arranged on the inner conductor 3, such as connectors, in particular plug-in or screw connectors, generally each with their associated connecting cables, these components can exert considerable forces on the inner conductor 3, for example during the operation of a motor vehicle when the feedthrough is fastened to a housing component of a functional assembly of the exhaust system of this motor vehicle. However, due to the rigid connection to the housing component 2, these forces must be fully absorbed by the inner conductor 3.

[0081] However, in the presently disclosed improved embodiments, the sleeve 6 can absorb such vibration-induced forces elastically to a large extent and thereby greatly reduce the forces acting on the inner conductor 3.

[0082] In the Figures 7, 8 and 9 In the bushings shown, a mechanical actuator 14 was attached to the upper end of their inner conductor 3, which introduced vibrations into them, which led to maximum accelerations of about 13 g (thus thirteen times the acceleration of the Earth's gravitational field at sea level), which are significantly above the operating loads for typical applications of such bushings.

[0083] From the presentation of Figure 8, in which the resulting voltages are shown in color, it can be seen that only low voltages occur within the inner conductor 3, the insulating component 5 and the outer conductor 4.

[0084] Figure 9 , which shows an enlarged detailed view of detail D 1 from Figure 8 in the region of the transition from the outer conductor 4 to the sleeve 6, reveals that mechanical stresses occur essentially only in the sleeve 6 and in the radially inwardly extending bridge section 7, which connects the sleeve 6 integrally to the outer conductor 5, and the lower section of the outer conductor 4, and that slight stresses still introduced into the insulating component 5 are to be classified as non-critical for the insulating component 5, since their maximum is below 0.23 MPa.

[0085] Essentially the same improvements could also be achieved with the other embodiments disclosed here by the respective sleeve 6, wherein the choice of the thickness of the cylindrical region DA of the outer conductor 4 relative to the thickness DH of the cylindrical region of the sleeve 6 was of essential importance, see for example Figure 2 . The thickness of the cylindrical region DA of the outer conductor 4 should preferably be approximately two to four times the thickness DH of the cylindrical region of the sleeve 6, and the axial extension EH of the cylindrical region of the sleeve 6 should be approximately three to ten times the thickness DH of the cylindrical region of the sleeve 6. In the preferred embodiments, the axial extension EH of the cylindrical region of the sleeve 6 was smaller than the axial extension EA of the cylindrical region of the outer conductor 4.

[0086] It is generally advantageous if the sleeve 6 forms a gap SP between the outer surface of the outer conductor 4 and an inner surface of the sleeve 4 in order to ensure that no damage to the outer conductor 4 or the sleeve 6 occurs in the event of vibrations or forces exerted on the inner conductor 3 that trigger a tilting movement.

[0087] For further, especially in the Figures 1 and 12 to 17, the sleeve 6 and the outer conductor 4 are each formed in two pieces and the sleeve 6 surrounds the outer conductor on its outer surface and has at least two mounting areas 15, 16 spatially spaced from one another.

[0088] In these embodiments, different materials can advantageously be used for the outer conductor and for the sleeve 6.Independently of each other, the material of the sleeve 6 or the outer conductor 4 can be made of metal, in particular iron, an iron alloy, an iron-chromium alloy, an iron-chromium-nickel alloy, an iron-nickel alloy, an iron-nickel-cobalt alloy, KOVAR, titanium, a titanium alloy, in particular of a metal from the group of steels, for example normal steels, stainless steels, stainless steels and high-temperature stable ferritic steels, which are also known under the brand name Thermax, for example Thermax 4016, Thermax4742, or Thermax4762 or Crofer22 APU or CroFer22 H or NiFe-based materials, for example NiFe45, NiFe47 or known under the brand name Inconel, for example Inconel 718 or X-750, or steels, for example known under the designations CF25, Alloy 600, Alloy 625, Alloy 690, SUS310S, SUS430, SUH446 or SUS316, or austenitic steels such as 1.4828 or 1.4841, aluminum, an aluminum alloy, AlSIC, magnesium or a magnesium alloy.

[0089] In the two-piece embodiments, the first mounting area 15 generally provides a mechanical connection between the sleeve 6 and the outer conductor 4, and the second mounting area 16 provides a mechanical connection between the sleeve 6 and the housing component 2 of the functional assembly, for example, an exhaust system of a motor vehicle. Preferably, the first mounting area 15 is formed on the inner surface of the sleeve 6, and the second mounting area 16 is formed on an outer circumferential surface of the sleeve 6.

[0090] Preferably, the second mounting area 16 is arranged radially and / or axially offset relative to the first mounting area 15.

[0091] At the Figure 1In the embodiment shown, the first mounting area 15 is formed, for example, by friction welding of the sleeve 6, which in this case preferably has a radially narrowed section in its lower area, and the second mounting area 16 comprises a welded connection, in particular a TIG or laser welded connection, as has already been described above for the one-piece embodiments.

[0092] In general, however, the first mounting region 15, which provides a mechanical connection of the outer conductor 4 to the sleeve 6, can be held in the mounted state with a soldered connection or a welded connection, in particular a resistance weld, friction weld, laser weld or TIG weld or by friction welding on the sleeve 6, in particular on a mounting region 17 of the sleeve 6.

[0093] In further embodiments, in the assembled state, the first mounting region 15 can also be held on the sleeve 6, in particular on a mounting region 17 of the sleeve 6, by a press fit or by mechanical pressing, in particular by point-shaped or regional depressions of the sleeve 6 in the radially inward direction.

[0094] The following refers to the Figures 12 to 17 illustrated embodiments, in which, for the sake of simplicity of illustration, the housing component 2 is not shown, but the location at which it is to be attached to the second mounting area 16 is nevertheless shown.

[0095] In the Figure 12 In the embodiment of the outer conductor 4 and the sleeve 6 shown, the sleeve 6 has a projecting bottom region 18 and the sleeve 6 is held on the outer conductor 6 by means of an annular weld seam 19 produced by laser welding with its projecting bottom region 18.

[0096] In this and the embodiments described below, the insulating component does not have a creepage distance extension 20, which extends upwards substantially in a ring shape around the inner conductor 3 at a distance therefrom and causes an enlargement of the surface between the inner conductor 3 and the outer conductor 4 along the upper surface of the insulating component 5, but rather the substantially planar upper surface 21 of the insulating component 5 runs substantially parallel to its likewise planar lower surface 22.

[0097] The Figures 13 to 17 The embodiments shown each have in the lower region of the sleeve 6 a radially narrowed section 23 of the sleeve 6 in the region of the first mounting section 15, which can already securely hold the outer conductor 4 by frictional forces, in particular during the assembly of the bushing 1.

[0098] Figure 13shows a cross-sectional view of the outer conductor 4 and the sleeve 6 of a further embodiment in which the sleeve 6 does not have a projecting bottom region 18 and a weld seam 19 is applied to the outer conductor 4 and the sleeve 6 by means of laser welding, which weld seam extends laterally in the lower radially narrowed section 23.

[0099] In the Figure 14 In the illustrated embodiment of the outer conductor 4 and the sleeve 6 with a radially projecting base section 18 and a radially narrowed section 23, a weld seam 19 is applied to the outer conductor 4 and the sleeve 6 in the region of the first mounting section 15 of the sleeve by means of laser welding, which weld seam extends laterally in the radially projecting base section 18.

[0100] Figure 15shows an embodiment of the outer conductor 4 and the sleeve 6 with a cantilevered base region 18 and a radially narrowed section 23 in the region of the first mounting section of the sleeve, in which the sleeve 6 is held to the outer conductor 4 by means of a soldered connection 24. In this embodiment, the soldered connection 24 can advantageously be produced simultaneously and thus during the glazing of the insulating component 5, since the temperatures required for glazing can reliably liquefy the solder used. For this purpose, the radially narrowed section of the sleeve 6, together with the outer conductor, forms an annular cavity in which the solder can be arranged before glazing and in which the soldered connection 24 is located after glazing.

[0101] Figure 16an embodiment of the outer conductor 4 and the sleeve 6 with a radially narrowed section 23 in the region of the first mounting section 15 can be seen, in which the sleeve 5 is held on the outer conductor 4 by means of a press fit 25 and / or by mechanical pressing, in particular by point-shaped or regional depressions 26 of the sleeve 6 in the radially inward direction.

[0102] Figure 17 discloses an embodiment of the outer conductor 4 and the sleeve 6 with a radially narrowed section 23 in the region of the first mounting section 15, in which the sleeve is held on the outer conductor by means of spot welds 27. List of reference symbols

[0103] 1 Feedthrough through a housing component 2 2 Housing component 3 Inner conductor 4 Outer conductor 5 Electrically insulating component 6 Sleeve 7 Radially inwardly extending bridge section which integrally connects the sleeve 6 to the outer conductor 5 8 Mounting area of ​​those embodiments in which the outer conductor and the sleeve are formed in one piece 9 Weld seam 10 Mounting area of ​​the housing component 2 11 Weld point 12 Weld seam of a conventional feedthrough 13 Weld point in the presently disclosed embodiments 14 Mechanical actuator 15 First mounting area 16 Second mounting area 17 Mounting area of ​​the sleeve 6 18 Projecting bottom area of ​​the sleeve 6 19 Weld seam, in particular laser weld seam 20 Creepage distance extension 21 Essentially planar upper surface of the insulating component 5 22 Planar lower surface of the insulating component 5 23 Radially narrowed section of the sleeve 6 in the area of ​​the first assembly section 15 24Solder connection 25Press fit D 1 Detail from Figure 8 D 2 Detail from Figure 10 DA Thickness of the cylindrical portion of the outer conductor 4 DH Thickness of the cylindrical portion of the sleeve 6 EA Axial extension of the cylindrical portion of the outer conductor 4 EH Axial extension of the cylindrical portion of the sleeve 6 S Line of symmetry

Claims

1. Feedthrough (1) in a housing component (2), in particular for harsh environments subject to mechanical and thermal loading, comprising an inner conductor (3), an outer conductor (4) and an electrically insulating component (5) between the outer conductor (4) and the inner conductor (3), the electrically insulating component preferably comprising a glass, in particular a crystallizable or at least partially crystallized glass, or a glass ceramic and retaining the inner conductor (3) relative to the outer conductor in electrically insulated fashion, wherein a sleeve (6) is assigned to or is formed on the outer conductor (4) and retains or makes it possible to fasten this feedthrough on a housing component (2) that is subject to thermal loading, in particular a functional assembly of the exhaust gas system of a motor vehicle, characterized in that a gap (SP) is formed through the sleeve (6) between the outer lateral surface of the outer conductor and an inner surface of the sleeve (6) in such a way that, in the event of vibrations, or forces that are exerted on the inner conductor (3) and trigger a tilting movement, no damage is done to the outer conductor (4) and the sleeve (6).

2. Feedthrough (1) according to Claim 1, wherein the inner conductor (3) has a cylindrically symmetrical, in particular cylindrical, form and the outer conductor (4) cylindrically symmetrically, in particular annularly, surrounds the inner conductor (3).

3. Feedthrough (1) according to Claim 1 or 2, wherein the sleeve (6) surrounds the outer lateral surface of the outer conductor (4) and has at least two spatially separate mounting regions or wherein the sleeve (6) is formed in one piece with the outer conductor (4) and forms at least one mounting region (15).

4. Feedthrough (1) according to Claim 3, wherein a first mounting region (15) provides a mechanical connection between the sleeve (6) and the outer conductor (4) and a second mounting region (16) provides a mechanical connection between the sleeve (6) and the housing component of the functional assembly in particular of the exhaust gas system of a motor vehicle.

5. Feedthrough (1) according to one of the preceding claims, wherein the sleeve (6) has a radially narrowed portion in the region of the first mounting portion (15).

6. Feedthrough (1) according to one of the preceding claims, wherein the first mounting region (15) is formed on the inner surface of the sleeve (6) and the second mounting region (16) is formed on an outer lateral surface of the sleeve (6).

7. Feedthrough (1) according to one of the preceding claims, wherein the second mounting region (16) is radially and / or axially offset relative to the first mounting region (15).

8. Feedthrough (1) according to one of the preceding claims, wherein the material of the sleeve (6) consists of or comprises metal, in particular iron, an iron alloy, an iron-chromium alloy, an iron-chromium-nickel alloy, an iron-nickel alloy or an iron-nickel-cobalt alloy, Kovar, titanium, a titanium alloy, in particular a metal from the group of steels, for example standard steels, stainless steels, nonrusting steels and high-temperature-stable ferritic steels, which are also known under the trade name Thermax, for example Thermax 4016, Thermax 4742, or Thermax 4762 or Crofer22 APU or Crofer22 H or NiFe-based materials, for example NiFe45, NiFe47 or those known under the trade name Inconel, for example Inconel 718 or X-750, or steels known for example under the designations CF25, Alloy 600, Alloy 625, Alloy 690, SUS310S, SUS430, SUH446 or SUS316, or austenitic steels such as 1.4828 or 1.4841, aluminium, an aluminium alloy, AlSIC, magnesium or else a magnesium alloy.

9. Feedthrough (1) according to one of the preceding claims, wherein the material of the outer conductor (4) consists of or comprises metal, in particular iron, an iron alloy, an iron-chromium alloy, an iron-chromium-nickel alloy, an iron-nickel alloy or an iron-nickel-cobalt alloy, Kovar, titanium, a titanium alloy, in particular a metal from the group of steels, for example standard steels, stainless steels, nonrusting steels and high-temperature-stable ferritic steels, which are also known under the trade name Thermax, for example Thermax 4016, Thermax 4742, or Thermax 4762 or Crofer22 APU or Crofer22 H or NiFe-based materials, for example NiFe45, NiFe47 or those known under the trade name Inconel, for example Inconel 718 or X-750, or steels known for example under the designations CF25, Alloy 600, Alloy 625, Alloy 690, SUS310S, SUS430, SUH446 or SUS316, or austenitic steels such as 1.4828 or 1.4841, aluminium, an aluminium alloy, AlSIC, magnesium or else a magnesium alloy.

10. Feedthrough according to one of Claims 4 to 9, wherein the second mounting region (16) provides a mechanical connection to the housing component of the functional assembly of the exhaust gas system of a motor vehicle and in the mounted state is connected to the housing component of the functional assembly of the exhaust gas system of a motor vehicle by a soldered connection or a welded connection, in particular a laser-welded or TIG-welded connection.

11. Feedthrough (1) according to one of Claims 4 to 10, wherein the first mounting region, which provides a mechanical connection between the outer conductor (4) and the sleeve (6), in the mounted state is formed by a soldered connection or a welded connection, in particular a resistance-welded, friction-welded, laser-welded or TIG-welded connection or by friction welding, on the sleeve (6), in particular is retained on a mounting region of the sleeve (6).

12. Feedthrough (1) according to one of Claims 4 to 11, wherein the first mounting region (15), which provides a mechanical connection between the outer conductor (4) and the sleeve (6), in the mounted state is retained on the sleeve (6), in particular on a mounting region of the sleeve (6), by a press fit or by mechanical pressing means, in particular by recesses at certain points or certain regions of the sleeve (6) in the radially inward direction.

13. Feedthrough (1) according to the preceding claim, wherein the coefficient of thermal expansion of the material of the outer conductor (4) is less than the coefficient of thermal expansion of the material of the sleeve (6).

14. Feedthrough (1) according to one of Claims 4 to 13, wherein the fastening means on the first mounting region (15) has a radially encircling form and an annularly closed fastening line formed on the first mounting region (15) is offset in relation to the lower and upper radial ends of the sleeve (6).

15. Feedthrough (1) according to one of Claims 4 to 14, wherein the second mounting region (16) formed on an outer lateral surface of the sleeve (6), or the at least one mounting region, has an encircling form, wherein an annularly closed fastening line formed on the second mounting region (16) is offset in relation to the lower and upper radial ends of the sleeve (6).

16. Feedthrough (1) according to one of the preceding claims, wherein the thickness of the cylindrical region DA of the outer conductor (4) is preferably approximately twice to four times the thickness (DH) of the cylindrical region of the sleeve (6) and in particular the axial extent EH of the cylindrical region of the sleeve (6) has approximately three to ten times the thickness DH of the cylindrical region of the sleeve (6).

17. Feedthrough (1) according to one of the preceding claims, wherein the axial extent EH of the cylindrical region of the sleeve (6) is less than the axial extent (EA) of the cylindrical region of the outer conductor (4) .

18. Feedthrough (1) according to one of the preceding claims, wherein the functional assembly of a motor vehicle is an exhaust-gas catalytic converter, in particular an electrically heated exhaust-gas catalytic converter (EHC) or an exhaust-gas catalytic converter comprising sensors, or is a turbocharger, in particular a turbocharger provided with an electric drive or a turbocharger comprising sensors and / or wherein the housing component that is subject to thermal loading is part of a chemical production plant.