electrical connections

Abstract

The invention relates to an electrical connection (10) comprising a bushing (12) having a geometric center axis (14), an electrical conductor (16) passing through the bushing (12) along the geometric center axis (14), and an insulation layer (18) electrically insulating the bushing (18) from the conductor (16). It is suggested to press the bushing 12, the insulation layer (18) and the electrical conductor (16) together, preferably during a rotary swaging process, to achieve a mechanical cold deformation.

Description

Technical Field

[0001] This invention relates to an electrical connector, comprising:

[0002] - Bushing with a geometric central axis;

[0003] - An electrical conductor passing through the bushing along its geometric central axis; and

[0004] - An insulating layer that makes the bushing electrically insulated from the conductor. Background Technology

[0005] Electrical connectors (or electrical connection devices) can be housed within a sheath or housing of the exhaust system of an internal combustion engine and electrically connected to electrical components to be housed within the sheath. The electrical components are preferably electrically heated grids or honeycomb structures of a catalytic converter, designed to be supplied with current via an electrical conductor after the electrical components are installed. The electrical connector is inserted into an opening in a mounting flange or sheath, and a bushing is secured in the opening, for example, by welding to the sheath. One end of the electrical conductor opposite the electrical component can be connected to a cable. The end of the cable opposite the electrical connector can be connected to a power source, such as a vehicle battery or control unit.

[0006] Such electrical connectors are well known in the art. For example, EP 2 828 932 B1 describes an electrical connector capable of drawing 30 amperes or more, up to several hundred amperes. The insulating layer is made of compressed ceramic powder and is virtually incompressible. The outer cross-section of the electrical connector has a non-circular shape, such as a polygonal cross-section, to prevent rotation of the electrical connector in the sheath or the like under very high torque.

[0007] US 6,025,578 describes an electrical connection having a sacrificial electrode, a protective layer, or other kind of protective configuration that contacts the bushing on the outside of a sheath to which the bushing is welded. The bushing is made of metal, and the insulating layer is made of aluminum oxide. The sacrificial electrode is a block of zinc. This prevents corrosion of the sacrificial electrode and protects the bushing or electrical conductor from corrosion in the event of an electrolyte buildup, such as brine, on top of the bushing.

[0008] EP 0 902 991 B1 describes the above-mentioned types of electrical connections. It is recommended to establish different types of connections between one end of the electrical conductor opposite the electrical component (e.g., the electrically heated grid or honeycomb structure of a catalytic converter) and the cable. Therefore, reliable electrical connections can be achieved quickly and easily.

[0009] Known electrical connectors have many disadvantages:

[0010] - A disadvantage of insulation layers made of ceramic materials is that when the bushing is welded to the sheath or housing, the insulation layer may crack due to the difference in thermal shrinkage values ​​between the bushing material and the ceramic material of the insulation layer, thus affecting the good insulation properties and airtightness of the electrical connection.

[0011] - During the use of electrical connections, temperatures may vary between ambient temperatures (as low as -40°C) when the internal combustion engine and catalytic converter are off and cooled down, and approximately +1,000°C when the internal combustion engine and catalytic converter are running. This may negatively affect the physical, mechanical, electrical, and thermal characteristics and performance of the electrical connections.

[0012] - Known electrical connectors can only withstand very limited amounts of force and torque. The main problem is not that the entire electrical connector loosens and detaches from the mounting flange or opening of the sheath or housing welded to it. Rather, the mechanical interconnection between the conductor and insulation and / or between the insulation and bushing can loosen and break due to large values ​​of force and / or torque acting on the electrical connector. For example, electrical connectors known from US 9,225,107 B2 can only absorb torque up to 8 Nm. This amount should be increased.

[0013] - The insulation layer may not provide a satisfactory seal. Gases or fluids (e.g., venting) may leak from inside the sheath or housing across electrical connections welded to mounting flanges or openings in the sheath or housing into the environment. These gases or fluids may be chemically corrosive, causing corrosion of the bushings and / or electrical conductors. For this reason, US 6,025,578 proposes a protective configuration to prevent corrosion. Summary of the Invention

[0014] Therefore, one object of the present invention is to provide an electrical connector that overcomes at least some of the aforementioned disadvantages. In particular, one object is to provide an electrical connector having the following properties:

[0015] - Electrical connections should be able to withstand a minimum voltage of up to 52V DC without damage, preferably up to 100V DC;

[0016] - Electrical connections should be able to withstand a minimum current of 150A, preferably up to 200A, without damage;

[0017] Electrical connections should have temperature stability and / or a certain degree of mechanical flexibility to compensate for large temperature changes exceeding 1,000°K without damage;

[0018] - Electrical connections shall provide an airtight seal (e.g., welded or screwed) to the sheath or housing to which they are attached, with a maximum leakage of less than 30 ml / min, preferably less than 25 ml / min, at a pressure of 0.3 bar in the sheath or housing;

[0019] - Electrical connections should provide good electrical insulation of the electrical conductors relative to the bushings and sheaths or housings, and in particular, electrical connections should provide an insulation resistance of more than 10 MΩ (preferably several GΩ) under ambient conditions (e.g., temperature 22°C + / - 2°C, pressure about 1,000 hPa and relative humidity 35% - 70%) and a DC voltage of 500 V;

[0020] - The electrical connection should have a disconnecting torque of more than 15 Nm, preferably more than 16 Nm, particularly more than 17 Nm, and especially about 20 Nm.

[0021] This objective is achieved by an electrical connector comprising the following features. Specifically, starting with the aforementioned type of electrical connector, it is proposed to press the bushing, insulation layer, and electrical conductor together to achieve mechanical cold transformation. The bushing, insulation layer, and electrical conductor are arranged coaxially with respect to the geometrical central axis of the bushing and then pressed together to achieve mechanical cold transformation. Preferably, the bushing, insulation layer, and electrical conductor are pressed together during a rotary forging process. Pressure acts on the outer circumferential surface of the bushing of the electrical connector. The pressure is preferably directed radially inward toward the geometrical central axis.

[0022] Due to mechanical cold deformation, the interconnections between the bushing and the insulation layer, as well as between the insulation layer and the electrical conductor, increase significantly. The electrical connectors can absorb higher force and torque values ​​without damage. In particular, the mechanical interconnections between the electrical conductor and the insulation layer and / or between the insulation layer and the bushing do not loosen or break, even when high force and torque values ​​are applied to the electrical connectors.

[0023] The bushing, insulation layer, and electrical conductor are preferably rotationally symmetrical about a geometric central axis. In particular, in a cross-sectional view, the bushing, insulation layer, and electrical conductor all have a circular or annular form.

[0024] The dimensions of the electrical conductor are tailored to withstand a minimum voltage of 52V DC and a current of up to 200A. For this purpose, a conductor diameter between 5.0mm and 8.0mm is recommended, preferably between 6.0mm and 7.5mm. The outer diameter of the bushing of the electrical connector is determined by the size of the mounting flange or opening in which the bushing is fixed and / or the intended use of the electrical connector. In particular, the bushing should fit neatly into the opening of the sheath or housing. Typical examples suitable for the bushing outer diameter are between 12.0mm and 18.0mm, preferably about 14.0mm. In cross-section, the thickness of the bushing between the inner and outer circumferential surfaces is preferably between 1.0mm and 5.0mm, preferably about 2.0mm. The thickness of the insulation layer depends on the given diameters of the electrical conductor and bushing, and the electrical properties achieved by the electrical connector. For example, under ambient conditions (e.g., temperature 22°C + / - 2°C, pressure approximately 1,000 hPa, and relative humidity 35% - 70%) and a DC voltage of 500V, the insulation layer should achieve an insulation resistance exceeding 10 MΩ (preferably up to several GΩ). To achieve these insulation properties, depending on the material used for the insulation layer, it has a thickness of at least 1.2 mm, preferably about 1.6 mm.

[0025] According to a preferred embodiment of the invention, it is proposed that the electrical conductor has an outer circumferential surface having at least one of the following: an arithmetic mean roughness of at least Ra = 1 μm (or higher), protrusions and recesses on at least a portion of the outer circumferential surface of the electrical conductor covered by an insulating layer. The roughness of the outer circumferential surface can be Ra > 2 µm, preferably Ra > 3 µm, particularly preferably Ra > 4 µm, Ra > 5 µm, or even Ra > 10 µm. The roughness is such that it provides protrusions (i.e., positive peaks) and / or recesses (i.e., negative peaks or valleys) that extend irregularly relative to the average surface. The desired roughness can be achieved during the manufacturing process of the electrical conductor, i.e., by machine turning, for example by reducing the rotational speed of machining the outer circumferential surface, for example by using a cutting or milling tool. In particular, if the rotational speed of machining the outer circumferential surface is reduced, the roughness of the circumferential surface may increase. Alternatively, the desired roughness value can also be achieved by additional process steps after the manufacture of the electrical conductor.

[0026] During mechanical cold deformation, pressure acts radially on the outer circumferential surface of the bushing. The bushing transmits at least a portion of the radial pressure to the insulation layer pressed against the outer circumferential surface of the electrical conductor. Some of the insulation material is pressed into recesses on the outer circumferential surface of the electrical conductor and / or protrusions on the outer circumferential surface of the electrical conductor are pressed into the insulation material. Thus, an interlocking connection is established between the electrical conductor and the insulation layer. This can further increase the force and torque values ​​that the electrical connection can absorb without damage. In particular, the mechanical interconnection between the electrical conductor and the insulation layer will not loosen or break, even when high force and torque values ​​are applied to the electrical connection.

[0027] Preferably, the protrusion has a cross-section having a base on the outer circumferential surface of the electrical conductor and sidewalls extending from the end of the base and converging toward the top of the protrusion. Similarly, the groove may have a cross-section having an opening on the outer circumferential surface and sidewalls extending from the end of the opening and converging toward the bottom of the groove. A preferred cross-section for the groove is U-shaped to facilitate the entry and diffusion of the insulating material into the groove. Of course, the groove may also have any other cross-section, such as a V-shaped cross-section or a combination of U and V shapes. A preferred cross-section for the protrusion is V-shaped, thus facilitating entry into the insulating material. Of course, the protrusion may also have any other cross-section, such as a U-shaped cross-section or a combination of V and U shapes. The preferred depth of the recess and the preferred height of the protrusion relative to the remainder of the outer circumferential surface of the electrical conductor may be between 0.05 mm and 0.3 mm, preferably about 0.15 mm.

[0028] Furthermore, it is recommended that the protrusions and / or recesses provided on the outer circumferential surface of the electrical conductor have circumferential longitudinal extension and / or axial longitudinal extension. For example, the protrusions or recesses may have a longitudinal extension extending along a fundamental circumferential direction, i.e., around the geometric central axis of the bushing. Alternatively, the protrusions or recesses may have a longitudinal extension extending along a fundamental axial direction, i.e., parallel to the geometric central axis of the bushing. Additionally, the protrusions and / or recesses may have longitudinal extensions extending both circumferentially and axially. In that case, the protrusions and / or recesses extend on the outer circumferential surface of the electrical conductor in an inclined or helical (i.e., spiral) manner. Such protrusions and / or recesses can be implemented during the manufacturing process of the electrical conductor, for example, by a specific feed rate relative to the rotational speed of the cutting or milling tool used to machine the outer circumferential surface and a specific depth of cut. Alternatively, the protrusions and / or recesses can also be implemented by additional process steps after the manufacture of the electrical conductor. Of course, it is also possible that the first set of protrusions and / or grooves have longitudinal extension in the first direction and the second set of protrusions and / or grooves have longitudinal extension in the second direction, and that the first set of protrusions and / or grooves intersects with the second set of protrusions and / or grooves.

[0029] Preferably, the protrusion or recess is part of the ribbed outer circumferential surface of the electrical conductor. The ribbed surface preferably includes a plurality of grooves. The grooves of a first set of grooves extend parallel to each other, preferably equidistant, as do the grooves of a second set of grooves. The grooves of the first set of grooves extend at an angle relative to the second set of grooves, the angle being greater than 0° and less than 180°. Preferably, the angle between the first and second grooves is 90°, resulting in a rectangular or square ribbed surface between the grooves. Alternatively, the angle can be between 10° and 80°, resulting in a rhomboid ribbed surface between the grooves. Of course, instead of grooves or other features, the ribbed surface may also include protrusions.

[0030] To facilitate the entry and diffusion of the insulating material into the grooves and / or to facilitate the entry of the protrusions into the insulating material, it is recommended that the insulating layer be made of a material with a lower hardness than the material used to make the electrical conductor. In particular, it is preferred that the insulating material has a hardness below 5.5 on the Mohs scale, and more preferably below that of magnesium oxide (MgO). Preferably, the insulating material has a Mohs hardness of about 1.5 to 4.0, particularly 2.0 to 3.0. In comparison, gold has a Mohs hardness of about 2.5 to 3.0, copper coins have a Mohs hardness of about 3.0, and steel has a Mohs hardness of about 6.0 to 6.5. The material used to make the electrical conductor has a greater hardness than the insulating material.

[0031] According to another preferred embodiment of the invention, it is proposed that the bushing has an inner circumferential surface having at least one of the following: protrusions and recesses on at least a portion of the inner circumferential surface of the bushing covering the insulating layer, having an arithmetically average roughness of at least Ra = 1 μm (or higher). Thus, the bushing has the form of a hollow cylinder, and the inner circumferential surface where the insulating layer of the bushing is located includes the desired roughness, protrusions, and / or recesses. The roughness of the inner circumferential surface can be Ra > 2 µm, preferably Ra > 3 µm, particularly preferably Ra > 4 µm, Ra > 5 µm, or even Ra > 10 µm. The roughness is such that it provides protrusions (i.e., positive peaks) and / or recesses (i.e., negative peaks or valleys) that extend irregularly relative to the average surface. The desired roughness can be achieved during the manufacturing process of the bushing, i.e., by machine turning, for example by reducing the rotational speed of machining the inner circumferential surface, for example by using a cutting or milling tool. In particular, reducing the rotational speed at which the inner circumferential surface is machined may increase the surface roughness. Alternatively, the desired roughness value can also be achieved through additional processing steps following the manufacture of the bushing.

[0032] During mechanical cold deformation, pressure acts radially on the outer circumferential surface of the bushing. The inner circumferential surface of the bushing is pressed radially against the insulation layer. Some of the insulation material is pressed into the recesses provided on the inner circumferential surface of the bushing and / or the protrusions provided on the inner circumferential surface of the bushing are pressed into the insulation material. Thus, an interlocking connection is established between the housing and the insulation layer. This can further increase the force and torque values ​​that the electrical connection can absorb without damage. In particular, the mechanical interconnection between the housing and the insulation layer will not loosen or break, even when high force and torque values ​​are applied to the electrical connection.

[0033] Preferably, the protrusion has a cross-section having a base on the inner circumferential surface of the bushing and sidewalls extending from the end of the base and converging toward the top of the protrusion. Similarly, the groove may have a cross-section having an opening on the inner circumferential surface and sidewalls extending from the end of the opening and converging toward the bottom of the groove. The groove preferably has a U-shaped cross-section to facilitate the entry and diffusion of the insulating material into the groove. Of course, the groove may also have any other cross-section, such as a V-shaped cross-section or a combination of U and V shapes. For the protrusion, the preferred cross-section is V-shaped, thus facilitating entry into the insulating material. Of course, the protrusion may also have any other cross-section, such as a U-shaped cross-section or a combination of V and U shapes. The preferred depth of the recess and the preferred height of the protrusion relative to the rest of the inner circumferential surface of the bushing may be between 0.05 mm and 0.3 mm, preferably about 0.15 mm.

[0034] Furthermore, it is suggested that the protrusions and / or recesses provided on the inner circumferential surface of the bushing have at least one of circumferential and axial extension. For example, the protrusions or recesses may have a longitudinal extension extending in a substantially circumferential direction, i.e., around the geometric central axis of the bushing. Alternatively, the protrusions or recesses may have a longitudinal extension extending in a substantially axial direction, i.e., parallel to the geometric central axis of the bushing. Furthermore, the protrusions and / or recesses may have longitudinal extensions extending in both the circumferential and axial directions. Thus, the protrusions and / or recesses extend on the inner circumferential surface of the bushing in an inclined or helical (i.e., spiral) manner. Such protrusions and / or recesses can be implemented during the bushing manufacturing process, for example, by a specific feed rate relative to the rotational speed and specific depth of cut of the cutting or milling tool used to machine the inner circumferential surface. Alternatively, the protrusions and / or recesses can also be implemented by additional process steps after the bushing is manufactured. Of course, it is also possible that the first set of protrusions and / or grooves extends longitudinally in the first direction and the second set of protrusions and / or grooves extends longitudinally in the second direction, and the first set of protrusions and / or grooves intersects with the second set of protrusions and / or grooves.

[0035] According to a preferred embodiment, the bushing has recesses in the form of axial grooves disposed on the inner circumferential surface of the bushing and spaced apart from each other in the circumferential direction. The grooves have a longitudinal extension extending in the axial direction, i.e., parallel to the geometric central axis of the bushing. Preferably, the grooves are equidistant from each other in the circumferential direction, i.e., each groove is separated from its adjacent groove by a given angle. If the angle is 120°, then there are three grooves equidistant from each other on the inner circumferential surface of the bushing. Of course, different numbers of grooves and different angles between the grooves, spaced equidistantly or unequally from each other, can also be provided.

[0036] Preferably, the axial groove does not extend along the entire axial direction of the inner circumferential surface of the bushing. Instead, it is recommended that the groove extend only along a portion of the inner surface of the bushing, starting from one end face of the bushing and ending at a distance from the opposite end face of the bushing. Therefore, the groove does not reach the opposite end face of the bushing. This can further increase the force and torque values ​​that the electrical connector can absorb without damage. In particular, the electrode displacement force acting on the electrical conductor in the direction toward the opposite end face of the bushing will prevent the electrical conductor from being pressed out or pulled out of the bushing along with the insulation layer. The electrode displacement force is preferably above 5,000 N, particularly between 5,500 N and 10,000 N.

[0037] To facilitate the entry and diffusion of the insulating material into the grooves and / or to facilitate the entry of the protrusions into the insulating material, it is recommended that the insulating layer be made of a material with a lower hardness than the material used to make the bushing. Preferably, the insulating material has a Mohs hardness of approximately 1.5 to 4.0, particularly 2.0 to 3.0. The bushing material has a higher hardness than the insulating material.

[0038] According to a preferred embodiment of the invention, it is recommended that the bushing and / or electrical conductor be made of stainless steel, particularly of a nickel-chromium-iron alloy. In principle, the bushing and / or electrical conductor can be made of any suitable material, provided that it possesses the necessary physical, mechanical, electrical, and thermal properties required for the electrical connection.

[0039] According to another preferred embodiment of the invention, it is recommended that the insulating layer be made of a material containing at least 50% foliated silicate minerals. Preferably, the insulating material contains more than 70%, particularly about 90%, foliated silicate minerals. The remainder of the material may be a laminate or an adhesive. Preferably, the insulating layer material has lower hygroscopicity than magnesium oxide (MgO). In principle, any material can be used for the insulating layer, as long as it possesses the necessary physical, mechanical, electrical, and thermal properties required for the insulating material of the electrical connector. In particular, the material should have sufficient elasticity to compensate for the thermal expansion of the different materials used in the electrical connector due to a wide range of thermal changes during the expected use of the electrical connector without breaking or cracking. Therefore, a high degree and long-lasting hermeticity of the electrical connector can be guaranteed. Attached Figure Description

[0040] Further features and advantages of the invention will now be described with reference to the accompanying drawings. It should be noted that each feature shown in the drawings and described herein may be important to the invention itself, even if not explicitly shown in the drawings or mentioned in the description. Furthermore, any combination of features shown in the drawings and described herein may be important to the invention, even if such combinations are not explicitly shown in the drawings or mentioned in the specification. The drawings show:

[0041] Figure 1 This is an example of an electrical connector according to a preferred embodiment of the present invention;

[0042] Figure 2 yes Figure 1 Exploded view of the electrical connectors;

[0043] Figure 3 yes Figure 2 A partial cross-sectional view of the electrical connector;

[0044] Figure 4 yes Figure 2 and Figure 3 Details A of the electrical conductor;

[0045] Figure 5 yes Figure 1 A partial cross-sectional view of the electrical connector;

[0046] Figure 6 shows the electrical connector of Figure 1 before mechanical cold deformation;

[0047] Figure 7 It is after mechanical cold deformation Figure 1 Electrical connectors;

[0048] Figure 8 It is the cross-section of the protrusion provided on the outer circumferential surface of the electrical conductor;

[0049] Figure 9 It is the cross-section through a groove set on the outer circumferential surface of an electrical conductor;

[0050] Figure 10 This is an example of using an electrical connector according to the invention;

[0051] Figure 11 This is an example of an electrical connector according to another preferred embodiment of the present invention;

[0052] Figure 12 yes Figure 11 Exploded view of the electrical connectors;

[0053] Figure 13 yes Figure 12Details of the electrical conductor, B;

[0054] Figure 14 This is another example of using the electrical connector according to the invention;

[0055] Figure 15 yes Figure 14 Details of the electrical connectors, C;

[0056] Figure 16 This is yet another example of using the electrical connector according to the invention; and

[0057] Figure 17 shows the details of the electrical connector D in Figure 16. Detailed Implementation

[0058] An electrical connector according to a preferred embodiment of the invention is indicated by reference numeral 10. The connector 10 includes a bushing 12 having a geometrical central axis 14. The bushing 12 is in the form of a hollow cylinder. Furthermore, the connector 10 includes an electrical conductor 16 passing through the bushing 12 along the geometrical central axis 14 and an insulating layer 18 electrically insulating the bushing 12 from the conductor 16. Figure 1 Figure 10 shows a fully assembled and ready-to-use electrical connector 10. Figure 2 shows an exploded view of the electrical connector 10.

[0059] The bushing 12, insulating layer 18, and electrical conductor 16 are preferably rotationally symmetrical about the geometric central axis 14. In particular, in a cross-sectional view, the bushing 12, insulating layer 18, and electrical conductor 16 are all in a circular or annular form.

[0060] like Figure 10 As schematically shown, the electrical connector 10 can be housed in the sheath or housing 100 of the exhaust system of the internal combustion engine and electrically connected to the electrical components 102 disposed in the sheath 100. Figure 10 Example 1 illustrates a specific type of electrical connector 10. Further embodiments will be described in more detail below. The electrical component 102 is preferably an electrically heated grid or honeycomb structure of the catalytic converter 104, designed to be supplied with current via the electrical conductor 16 of the electrical connector 10 after the electrical component 102 has been placed. Figure 10 In the diagram, the catalytic converter 104 or its casing 100 are shown in cross-section to allow observation of the internal portion of the casing 100. During use, the catalytic converter 104 or its casing 100 are hermetically sealed to prevent exhaust gas from escaping from the internal portion of the casing 100.

[0061] Electrical connector 10 is inserted into mounting flange or opening 106 of sleeve 100, and bushing 12 is secured in mounting flange or opening 106, for example by welding to sleeve 100. Alternatively, bushing 12 may also be secured to sleeve 100 in mounting flange or opening 106 in any other way, such as by threads.

[0062] The inner end (inside the sheath 100) of the electrical conductor 16 of the electrical connector 10 is connected to the electrical component 102. The outer end (outside the sheath 100) of the electrical conductor 16, opposite to the electrical component 102, can be connected to a cable (not shown), etc. Preferably, the electrical conductor 16 of the electrical connector 10 is provided with a positive charge (+). The end of the cable opposite to the electrical connector 10 can be connected to a power source (not shown), such as a battery or control unit of a motor vehicle, preferably connected to the positive terminal of the battery or control unit.

[0063] Similarly, the inner end of the conductor of another electrical connector (not shown) is connected to electrical component 102. This connector can be implemented directly or indirectly via the internal housing of electrical component 102. The outer end of the conductor of the other electrical connector opposite electrical component 102 can be connected to a cable (not shown), etc. Preferably, the conductor 16 of the other electrical connector is provided with a negative charge (-), for example, connected to a ground terminal or ground wire terminal (e.g., vehicle body or chassis). The end of the cable opposite the other electrical connector can be connected to a power source (not shown), such as a battery or control unit of a motor vehicle, preferably connected to the negative terminal or ground terminal or ground wire terminal of the battery or control unit. In the latter case, the negative terminal of the battery will be connected to a ground terminal or ground wire terminal at another point.

[0064] Finally, the electrical conductor (not shown) of the other electrical connector functions solely as an electrically insulating retaining pin, suitable for holding the internal housing of electrical component 102 or the electrical component 102 itself within the sheath 100. For this purpose, it is recommended that the inner end of the electrical conductor of the other electrical connector be connected to the internal housing of electrical component 102 or to the electrical component 102 itself. This connector is preferably conductive and can be achieved, for example, by welding, screwing, or any other means. The electrical conductor of the other electrical connector is electrically insulated relative to the bushing by an insulating layer. Thus, the other electrical connector isolates the internal housing relative to the sheath 100.

[0065] Of course, the electrical connector 10 according to the invention is not limited to the different uses described herein as examples. The electrical connector 10 can also be used in many other applications.

[0066] According to the present invention, the bushing 12, the insulating layer 18, and the electrical conductor 16 are pressed together to achieve mechanical cold deformation. First, the bushing 12, the insulating layer 18, and the electrical conductor 16 are arranged coaxially with respect to the geometrical center axis 14 of the bushing 12 (see...). Figure 6For this purpose, prior to mechanical cold deformation, the inner diameter of the inner circumferential surface 12a of the bushing 12 is slightly larger than the outer diameter of the insulating layer 18. For example, the inner diameter of the bushing 12 may be approximately 0.1 mm larger than the outer diameter of the insulating layer 18 to allow the bushing 12 to slide on the insulating layer 18. Similarly, the outer diameter of the outer circumferential surface 16b of the electrical conductor 16 is slightly smaller than the outer diameter of the insulating layer 18. The inner diameter of the insulating layer 18 is, for example, approximately 0.1 mm smaller than the outer diameter of the insulating layer 18. After arranging the bushing 12, the insulating layer 18, and the electrical conductor 16 coaxially with respect to the geometrical center axis 14 of the bushing 12, these components 12, 18, and 16 are pressed together to achieve mechanical cold deformation (see...). Figure 7 ).

[0067] Preferably, the bushing 12, the insulating layer 18, and the electrical conductor 16 are pressed together during the rotary forging process, thereby achieving mechanical cold deformation. Pressure acts on the outer circumferential surface of the bushing 12 of the electrical connector 10. The pressure is preferably directed radially inward toward the geometric central axis 14. Due to the pressure and mechanical cold deformation, the original dimensions (diameter A and length B) of the electrical connector 10 change (diameter A1 and length B1). Specifically, the diameter will decrease while the length will increase (A1...).<A;B1> B), as shown in Figure 6 and Figure 7 As shown. Preferably, the dimensional changes refer to the bushing 12 and the insulating layer 18, while the electrical conductor 16 will essentially retain its original dimensions.

[0068] The pressure acting on the electrical connector 10 can also alter the structure of the materials used for the bushing 12, the insulation layer 18, and the electrical conductor 16. In particular, the materials of the insulation layer 18 and / or the bushing 12 may be hardened due to the pressure applied to the electrical connector 10, and / or their bending fatigue strength may increase.

[0069] Due to mechanical cold deformation, the interconnections between bushing 12 and insulation layer 18, and between insulation layer 18 and electrical conductor 16, are significantly increased. Electrical connector 10 can absorb higher force and torque values ​​without damage. In particular, the mechanical interconnections between electrical conductor 16 and insulation layer 18 and / or between insulation layer 18 and bushing 12 will not loosen or break, even when high force and torque values ​​are applied to electrical connector 10 during its intended use.

[0070] The electrical conductor 10 and its components (bushing 12, insulation layer 18, and electrical connector 16) can be custom-sized and / or manufactured from special materials such that the electrical connector 10 can withstand up to 100 V DC and transmit up to 200 A. For this purpose, it is recommended that the diameter of the conductor 16 be between 5.0 mm and 8.0 mm, preferably between 6.0 mm and 7.5 mm. The outer diameter A1 of the bushing 12 is determined by the customer and / or the intended use of the electrical connector 10.

[0071] Specifically, the bushing 12 should be neatly fitted into the opening 106 in the sheath or housing 100. Typical examples of suitable outer diameter A1 for the bushing 12 are between 12.0 mm and 18.0 mm, preferably about 14.0 mm. In cross-section, the bushing 12 has an inner circumferential surface 12a and an outer circumferential surface 12b (see...). Figure 2 The thickness of the insulating layer 18 is preferably between 1.0 mm and 5.0 mm, and more preferably about 2.0 mm. The thickness of the insulating layer 18 depends on the given diameters of the electrical conductor 16 and the bushing 12, and the electrical or insulating properties achieved by the electrical connector 10. For example, the insulating layer 18 should achieve an insulation resistance of at least 10 MΩ, preferably up to several GΩ, under ambient conditions at a DC voltage of 500 V. Depending on the material used for the insulating layer 18, it has a thickness of at least 1.2 mm, preferably about 1.6 mm. Of course, these are merely exemplary values, particularly applicable to… Figure 10 The intended use is illustrated. When the electrical connector 10 is used in other applications, one or more of its physical, mechanical, electrical, and thermal properties and performance can change significantly.

[0072] It is recommended that the electrical conductor 16 have an outer circumferential surface 16b, the outer circumferential surface 16b having an arithmetic mean roughness of at least Ra = 1 μm (or higher) and / or protrusions and / or recesses 20 on at least a portion 16a of the outer circumferential surface 16b, the outer circumferential surface 16b being covered by an insulating layer 18 during assembly (see [link]). Figures 2 to 4 The roughness of the circumferential surface 16b is such that it provides irregularly distributed protrusions (i.e., positive peaks) and / or recesses (i.e., negative peaks or valleys) 20 relative to the average surface. The desired roughness can be achieved during the manufacture of the electrical conductor 16, i.e., by machine turning, for example by reducing the rotational speed of machining the outer circumferential surface 16b, for example by using a cutting or milling tool. In particular, if the rotational speed of machining the outer circumferential surface 16b is reduced, the roughness of the circumferential surface 16b of the electrical conductor 16 may increase. Alternatively, the desired roughness value can also be achieved by additional process steps after the manufacture of the electrical conductor 16.

[0073] During mechanical cold deformation, pressure acts radially on the outer circumferential surface 12b of the bushing 12. The bushing 12 transmits at least part of the radial pressure to the insulating layer 18, which is pressed against the outer circumferential surface 16b of the bushing 12. Some insulating material is pressed into the recesses 20 provided on the electrical conductor 16 and / or the protrusions 20 provided on the electrical conductor 16 are pressed into the insulating material of the insulating layer 18. Thus, an interlocking connection is established between the electrical conductor 16 and the insulating layer 18. This can further increase the force and torque values ​​that the electrical conductor 10 can absorb without damage. In particular, the mechanical interconnection between the electrical conductor 16 and the insulating layer 18 will not loosen or break, even when high force and torque values ​​are applied to the electrical connection 10.

[0074] like Figure 8 As shown, the protrusion 20 preferably has a cross-section having a base 22a on the outer circumferential surface 16b of the electrical conductor 16 and sidewalls 22b extending from the end of the base 22a and preferably converging toward the top of the protrusion 20. Similarly, as Figure 9 As shown, the groove 20 may have a cross-section having an opening 24a on the outer circumferential surface 16b and a sidewall 24b extending from the end of the opening 24a and preferably converging toward the bottom of the groove 20.

[0075] The preferred cross-section for the groove 20 is U-shaped to facilitate the entry of the material of the insulating layer 18 into the groove 20 and its diffusion within the groove 20 (see [link]). Figure 9 Of course, the groove 20 can also have any other cross-section, such as a V-shaped cross-section or a combination of U-shaped and V-shaped. Given the roughness of the outer circumferential surface 16b of the electrical conductor 16, the grooves can have any irregular shape and location and can be distinguished from each other.

[0076] The preferred cross-section for the protrusion 20 is V-shaped, thus allowing the protrusion 20 to more easily penetrate the material of the insulating layer 18 (see [link]). Figure 8 Of course, the protrusion 20 can also have any other cross-section, such as a U-shaped cross-section or a combination of V-shape and U-shape. In the case of roughness on the outer circumferential surface 16b of the electrical conductor 16, the protrusions can have any irregular shape and position and can be distinguished from each other.

[0077] The preferred depth of the groove 20 and the preferred height of the protrusion 20 relative to the rest of the outer circumferential surface 16b of the electrical conductor 16 can be between 0.05 mm and 0.3 mm, respectively, and are preferably about 0.15 mm. Of course, these are just exemplary values, and there may be significant differences in practice.

[0078] Furthermore, it is recommended that the protrusions 20 and / or grooves 20 provided on the outer circumferential surface 16b of the electrical conductor 16 have circumferential longitudinal extension and / or axial longitudinal extension. For example, as Figure 4 As shown, the protrusion or recess 20a may have a longitudinal extension extending in a generally circumferential direction, i.e., around the geometric central axis 14 of the bushing 12. Alternatively, the protrusion or recess 20b may have a longitudinal extension extending in a generally axial direction, i.e., parallel to the geometric central axis 14 of the bushing 12. Furthermore, the protrusion and / or recess 20 may have longitudinal extensions extending both circumferentially and axially. Thus, the protrusion and / or recess 20 extend on the outer circumferential surface 16b of the electrical conductor 16 (not shown) in an inclined or helical (i.e., spiral) manner. Such protrusions and / or recesses 20 can be achieved during the manufacture of the electrical conductor 16, for example, by a specific feed rate relative to the rotational speed and specific depth of cut of the cutting or milling tool used to machine the outer circumferential surface 16b. Alternatively, the protrusion and / or recess 20 may also be achieved by additional process steps after the manufacture of the electrical conductor 16. Of course, it is also possible that the first set of protrusions and / or grooves 20a has a longitudinal extension in the first direction and the second set of protrusions and / or grooves 20b has a longitudinal extension in the second direction, and the first set of protrusions and / or grooves 20a intersects with the second set of protrusions and / or grooves 20b (see...). Figure 4 ).

[0079] Preferably, the protrusion or groove 20 is part of the ribbed outer circumferential surface 16a of the electrical conductor 16, such as... Figure 4 As shown in the diagram. The ribbed surface 16a preferably includes a plurality of grooves 20a, 20b. A first set of grooves 20a extends parallel to each other, preferably at equal intervals, and a second set of grooves 20b extends parallel to each other, preferably at equal intervals. The first set of grooves 20a extends relative to the second set of grooves 20b at an angle greater than 0° and less than 180°. Preferably, the angle between the first groove 20a and the second groove 20b is 90°, resulting in a rectangular or square ribbed surface 16a between the grooves 20a, 20b (see...). Figure 4 Alternatively, the angle can be between 10° and 80°, preferably about 60°, thereby creating a rhomboid ribbed surface 16a between the grooves 20a and 20b (see...). Figure 13 Of course, instead of grooves 20a and 20b, or in addition to grooves 20a and 20b, the ribbed surface 16a may also include protrusions.

[0080] To facilitate the entry and diffusion of the material of the insulating layer 18 into the groove 20 and / or to facilitate the entry of the protrusion 20 into the material of the insulating layer 18, it is recommended that the insulating layer 18 be made of a material with a lower hardness than the material used to make the conductor 16 during mechanical cold deformation when external pressure is applied to the electrical connector 10. Preferably, the material of the insulating layer 18 has a Mohs hardness of about 1.5 to 4.0, particularly 2.0 to 3.0. In comparison, gold has a Mohs hardness of about 2.5 to 3.0, copper coins have a Mohs hardness of about 3.0, and steel has a Mohs hardness of about 6.0 to 6.5. The material of the electrical conductor 16 has a greater hardness than the insulating material.

[0081] Furthermore, it is suggested that the bushing 12 has an inner circumferential surface 12a, which has at least one of the following: an arithmetic mean roughness of at least Ra = 1 μm (or higher), protrusions and recesses 26 on at least a portion of the inner circumferential surface 12a, and the inner circumferential surface 12a is covered by an insulating layer 18 during assembly. Thus, the bushing 12 can have the form of a hollow cylinder, and the inner circumferential surface 12a where the insulating layer 18 of the bushing 12 is located includes the desired roughness, protrusions, and / or recesses 26. The roughness of the circumferential surface 12a is such that it provides protrusions (i.e., positive peaks) and / or recesses (i.e., negative peaks or valleys) that extend irregularly relative to the average surface. The desired roughness can be achieved during the manufacture of the bushing 12, i.e., by machine turning, for example by reducing the rotational speed of machining the inner circumferential surface 12a, for example by using a cutting or milling tool. In particular, if the rotational speed for machining the inner circumferential surface 12a is reduced, the roughness of the circumferential surface 12a may increase. Alternatively, the desired roughness value can also be achieved through additional processing steps after the manufacture of the bushing 12.

[0082] During mechanical cold deformation, pressure acts radially on the outer circumferential surface 12b of the bushing 12. The inner circumferential surface 12a of the bushing 12 is pressed radially against the insulating layer 18. Certain insulating materials of the insulating layer 18 are pressed into recesses 26 provided on the inner circumferential surface 12a of the bushing 12, and / or protrusions 26 provided on the inner circumferential surface 12a of the bushing 12 are pressed into the insulating material of the insulating layer 18. Thus, an interlocking connection is established between the bushing 12 and the insulating layer 18. This further increases the force and torque values ​​that the electrical conductor 10 can absorb without damage. In particular, the mechanical interconnection between the bushing 12 and the insulating layer 18 will not loosen or break, even when high force and torque values ​​are applied to the electrical connector 10.

[0083] Preferably, similar to Figure 8 and Figure 9As shown in the diagram and described above regarding the protrusions and grooves 20 of the electrical conductor 16, the protrusion 26 of the inner circumferential surface 12a of the bushing 12 has a cross-section having a base on the inner circumferential surface 12a of the bushing 12 and sidewalls extending from the end of the base and preferably converging toward the top of the protrusion 26. Similarly, the groove 26 may have a cross-section having an opening on the inner circumferential surface 12a and sidewalls extending from the end of the opening and preferably converging toward the bottom of the groove.

[0084] The preferred cross-section for the groove 26 is U-shaped to facilitate the entry and diffusion of the material of the insulating layer 18 into the groove 26. Of course, the groove 26 can also have any other cross-section, such as a V-shaped cross-section or a combination of U-shaped and V-shaped. Given the roughness of the inner circumferential surface 12a of the bushing 12, the grooves can have any irregular shape and location and can be distinguished from each other.

[0085] The preferred cross-section for the protrusion 26 is V-shaped, so that the protrusion 26 can more easily penetrate into the material of the insulating layer 18. Of course, the protrusion 26 can also have any other cross-section, such as a U-shaped cross-section or a combination of V-shape and U-shape. In the case of roughness on the inner circumferential surface 12a of the bushing 12, the protrusions can have any irregular shape and position and can be distinguished from each other.

[0086] The preferred depth of the groove 26 and the preferred height of the protrusion 26 relative to the rest of the inner circumferential surface 12a of the bushing 12 can be between 0.05 mm and 0.3 mm, respectively, and are preferably about 0.15 mm. Of course, these are just exemplary values ​​and may vary considerably in practice.

[0087] Furthermore, it is suggested that the protrusions and / or recesses 26 provided on the inner circumferential surface 12a of the bushing 12 have at least one of circumferential and axial extension. For example, the protrusions or recesses 26 may have a longitudinal extension extending in a substantially circumferential direction (not shown), i.e., around the geometrical central axis 14 of the bushing 12. Alternatively, the protrusions or recesses 26 may have a longitudinal extension extending in a substantially axial direction, i.e., parallel to the geometrical central axis 14 of the bushing 12 (see [link to relevant documentation]). Figure 2 , 3(5 and 12). Furthermore, the protrusions and / or grooves 26 may have longitudinal extensions extending in both the circumferential and axial directions. Thus, the protrusions and / or grooves 26 extend on the inner circumferential surface 12a of the bushing 12 in an inclined or helical (i.e., spiral) manner (not shown). Such protrusions and / or grooves 26 can be implemented during the manufacture of the bushing 12, for example, by a specific feed rate for a specific depth of cut relative to the rotational speed of the cutting or milling tool used to machine the inner circumferential surface 12a. Alternatively, the protrusions and / or grooves 26 may also be implemented after the manufacture of the bushing 12 by additional process steps. Of course, it is also possible that the first set of protrusions and / or grooves 26 has a longitudinal extension in a first direction and the second set of protrusions and / or grooves 26 has a longitudinal extension in a second direction, and the first set of protrusions and / or grooves 26 intersects with the second set of protrusions and / or grooves 26.

[0088] according to Figure 2 , Figure 3 , Figure 5 and Figure 12 In the preferred embodiment shown, the bushing 12 has grooves, which are in the form of axial grooves 26 spaced apart from each other in the circumferential direction and disposed on the inner circumferential surface 12a of the bushing 12. The grooves 26 have a longitudinal extension in the axial direction, i.e., parallel to the geometric central axis 14 of the bushing 12. Preferably, the grooves 26 are equidistant from each other in the circumferential direction, i.e., each is separated from the adjacent groove by a given angle. If the angle is 60°, there are six grooves 26 equidistant from each other on the inner circumferential surface 12a of the bushing 12. Of course, different numbers of grooves 26 and different angles between the grooves 26, equidistant from each other or not equidistant from each other, can also be provided.

[0089] Preferably, the axial groove 26 does not extend along the entire axial direction of the inner circumferential surface 12a of the bushing 12. Instead, it is suggested that the groove 26 extends only along a portion of the inner surface 12a of the bushing 12, starting at one end face 12c of the bushing 12 and terminating at a distance from the opposite end face 12d of the bushing 12. This can be achieved by... Figure 3 and Figure 5 As can be seen from this, the groove 26 does not reach the opposite end face 12d of the bushing 12. This can further increase the force and torque values ​​that the electrical connector 10 can absorb without damage. In particular, the force F acting on the electrical conductor 16 in the direction toward the opposite end face 12d of the bushing 12 (see...) Figure 3 and Figure 12 This will prevent the conductor 16 from being pressed out or pulled out of the bushing 12 along with the insulating layer 18. The force F is also called the electrode displacement force. The electrode displacement force F is preferably higher than 5,000 N, especially 5,500 N to 10,000 N.

[0090] Figures 11 to 13 Another preferred embodiment of the electrical connector 10 according to the invention is shown. Specifically, in this embodiment, the first set of grooves 20a extends relative to the second set of grooves 20b at an angle between 10° and 80°, preferably about 60°, thereby creating a rhomboid ribbed surface 16a between the grooves 20a, 20b (see [link to original text]). Figure 13 Of course, instead of grooves 20a and 20b, or in addition to grooves 20a and 20b, the ribbed surface 16a may also include protrusions.

[0091] Of course, the outer circumferential ribbed surface 16a can also have any other design, as long as it allows the mechanical shape-fitting interaction between the insulation layer 18 and the electrical conductor 16 to achieve an interlocking connection between the two and enhance the fixation of the insulation material 18 on the outer circumferential surface 16b of the electrical conductor 16.

[0092] exist Figure 11 As can be seen, the ribbed surface 16a has a greater axial extension than the insulating layer 18 and the bushing 12. This allows for precise positioning of the electrical conductor 16 relative to the bushing 12 before the bushing 12, insulating layer 18 and electrical conductor 16 are pressed together during the manufacturing process to achieve mechanical cold deformation.

[0093] Figure 14 and Figure 15 The opening 106 is shown in the sleeve or housing 100 fixed in, for example, the exhaust system of an internal combustion engine. Figures 11 to 13 Electrical connector 10. Electrical connector 10 can be secured in opening 106 by welding, screwing, or similar connection techniques. Figure 14 and Figure 15 In the image, the solder bead 110 is visible. Alternatively or additionally, the electrical connector 10 may also be provided with a radially projecting collar (not shown) that rests on the outer surface of the sheath 100 when the electrical connector 10 is introduced into the opening 106. The collar may further support the hermetically tight fixation of the electrical connector 10 in the opening 106 of the sheath 100.

[0094] Figure 16 and Figure 17 Another embodiment of an electrical connector 10 is shown, fixed in an opening 106 of a sheath or housing 100, such as that of an internal combustion engine exhaust system. The ribbed outer circumferential surface 16 may include a groove 20 extending around the entire or part of the circumference of the outer surface 16b of the electrical conductor 16. The groove 20 may be annular or helical in form. The electrical connector 10 may be fixed in the opening 106 by welding, screwing, or similar connection techniques. (See Figures 16 and...) Figure 17In this configuration, the electrical connector is secured in the opening by screws. For this purpose, the outer surface 12b of the bushing 12, or at least a portion thereof, is provided with external threads. Corresponding internal threads may be provided in the opening 106. Alternatively or additionally, the electrical connector 10 may also be provided with a radially projecting collar (not shown), which rests on the outer surface of the sheath 100 when the electrical connector 10 is introduced into the opening 106. The collar may further support the airtight securing of the electrical connector 10 in the opening 106 of the sheath 100.

[0095] To facilitate the entry and diffusion of the material of the insulating layer 18 into the groove 26 and / or to facilitate the entry of the protrusion 26 into the material of the insulating layer 18, it is recommended that the insulating layer 18 be made of a material with a lower hardness than the material used to make the bushing 12. Preferably, the material of the insulating layer 18 has a Mohs hardness of about 1.5 to 4.0, particularly 2.0 to 3.0. The material of the bushing 12 has a greater hardness than the insulating material.

[0096] It is recommended that the bushing 12 and / or the electrical conductor 16 be made of stainless steel, particularly of a nickel-chromium-iron alloy. The material of the bushing 12 and / or the electrical conductor 16 may include at least 70% nickel (plus cobalt), 10-20% chromium, and 3-15% iron. In addition to these components, the material may also contain small amounts (<2%) of carbon, manganese, sulfur, silicon, and / or copper. Preferably, the material of the bushing 12 and / or the electrical conductor 16 includes at least 72% nickel (plus cobalt), 14-17% chromium, and 6-10% iron. It may be advantageous if both the bushing 12 and the electrical conductor 16 are made of the same material. In principle, all materials suitable for providing the necessary physical, mechanical, electrical, and thermal properties required for the electrical connector 10 can be used for the bushing 12 and the electrical conductor 16.

[0097] It is further suggested that the insulating layer 18 be made of a material containing at least 50% foliated silicate minerals. Preferably, the insulating material contains more than 70%, particularly about 90%, of foliated silicate minerals. The remaining material of the insulating layer 18 may be a laminate or adhesive. Preferably, the material of the insulating layer 18 has a lower hygroscopicity than magnesium oxide (MgO). In principle, all materials suitable for providing the necessary physical, mechanical, electrical, and characteristic properties required for the electrical connector 10 can be used for the insulating layer 18. In particular, the material should have sufficient elasticity to compensate for the thermal expansion of the different materials used in the electrical connector 10 due to the wide range of thermal changes (above 1,000°K) during the expected use of the electrical connector 10 without breakage or cracking. Therefore, a high degree and long-lasting hermeticity of the electrical connector 10 can be guaranteed.

[0098] In summary, the present invention has the following advantages:

[0099] When the bushing 12 is welded to the sheath or housing 100, the insulation layer 18 will not break or crack due to the difference in thermal shrinkage values ​​between the materials of the bushing 12 and the insulation layer 18. This achieves electrical insulation and airtightness of the electrical connector 10. The insulation resistance exceeds 10 MΩ at 500 V DC and can even reach values ​​of several GΩ.

[0100] During the use of electrical connector 10, the temperature may vary between ambient temperature (as low as -40°C) when the internal combustion engine and catalytic converter 104 are off and cooled down, and as high as approximately +1,000°C when the internal combustion engine and catalytic converter 104 are running (causing temperature variations exceeding 1,000°K). Electrical connector 10 can withstand these large temperature fluctuations without negatively impacting its physical, mechanical, electrical, and thermal characteristics and performance.

[0101] The electrical connector 10 is capable of withstanding very high forces and torques applied thereto. Specifically, the mechanical interconnections between the electrical conductor 16 and the insulation layer 18 and / or between the insulation layer 18 and the bushing 12 will not loosen or break due to large forces and / or torques acting on the electrical connector 10. The electrical connector 10 can withstand a disconnecting torque greater than 15 Nm, preferably greater than 16 Nm, particularly preferably greater than 17 Nm, and especially about 20 Nm.

[0102] The sealing effect of the electrical connector 10 is particularly high due to the improved mechanical interconnection of the insulation layer 18 toward the electrical conductor 16 and / or bushing 12. A small amount of leakage of gas or fluid (e.g., exhaust gas) from the interior of the sheath or housing 100 across the electrical connector 10 to the environment is permissible. This invention significantly reduces leakage. The electrical connector 10 achieves a leakage value of less than 20 ml / min at a pressure of 0.3 bar.

Claims

1. An electrical connection (10) comprising: - a bushing (12) having a geometric center axis (14); - an electrical conductor (16) passing through the bushing (12) along the geometric center axis (14); and - an insulation layer (18) electrically insulating the bushing (12) from the electrical conductor (16); characterized in that the material of which the insulation layer (18) is made is less hard than the material of which the bushing (12) is made, the bushing (12), the insulation layer (18) and the electrical conductor (16) are pressed together to achieve a mechanical cold deformation.

2. The electrical connection (10) according to claim 1, characterized in that the electrical conductor (16) has an outer circumferential surface (16b) having at least one of the following: an arithmetic average roughness of at least Ra = 1 μm, protrusions and recesses (20; 20a, 20b) located on at least a portion (16a) of the electrical conductor (16); the outer circumferential surface (16b) is covered by the insulation layer (18).

3. The electrical connection (10) according to claim 2, characterized in that at least one of the protrusions and recesses (20; 20a, 20b) has at least one of a circumferential extension and an axial extension.

4. The electrical connection (10) according to claim 2 or 3, characterized in that the protrusions or recesses (20; 20a, 20b) are part of a ribbed outer circumferential surface (16a) of the electrical conductor (16) with a plurality of grooves (20a, 20b).

5. The electrical connection (10) according to one of claims 1 to 3, characterized in that the material of which the insulation layer (18) is made is less hard than the material of which the electrical conductor (16) is made.

6. The electrical connection (10) according to one of claims 1 to 3, characterized in that the bushing (12) has an inner circumferential surface (12a) having at least one of the following: an arithmetic average roughness of at least Ra = 1 μm, protrusions and recesses (26) located on at least a portion of the inner circumferential surface (12a) of the bushing (12); the inner circumferential surface (12a) covers the insulation layer (18).

7. The electrical connection (10) according to claim 6, characterized in that at least one of the protrusions and recesses (26) located on at least a portion of the inner circumferential surface (12a) of the bushing (12) has at least one of a circumferential extension and an axial extension.

8. The electrical connection (10) according to claim 6, characterized in that the bushing (12) has recesses (26) in the form of axial grooves spaced apart from each other in the circumferential direction.

9. The electrical connection (10) according to claim 8, characterized in that the axial grooves (26) extend over a portion of the inner circumferential surface (12a) of the bushing (12), starting from one end face (12c) of the bushing (12) and ending at a distance from the opposite end face (12d) of the bushing (12).

10. The electrical connection (10) according to one of claims 1 to 3, characterized in that At least one of the bushing (12) and the electrical conductor (16) is made of stainless steel.

11. The electrical connection (10) according to one of claims 1 to 3, characterized in that The insulation layer (18) is made of a material comprising at least 50% of a phyllosilicate mineral.

12. The electrical connection (10) according to claim 10, characterized in that At least one of the bushing (12) and the electrical conductor (16) is made of Inconel.

13. A method of manufacturing an electrical connection (10) comprising: - a bushing (12) having a geometric center axis (14); - an electrical conductor (16) passing through the bushing (12) along the geometric center axis (14); and - an insulation layer (18) electrically insulating the bushing (12) from the electrical conductor (16); characterized in that the material of which the insulation layer (18) is made is less hard than the material of which the bushing (12) is made, the bushing (12), the insulation layer (18) and the electrical conductor (16) are coaxially arranged relative to the geometric center axis (14) and then pressed together by mechanical cold deformation.

14. The method according to claim 13, characterized in that the bushing (12), the insulation layer (18) and the electrical conductor (16) are pressed together during a rotary swaging process.

15. The method according to claim 13 or 14, characterized in that the electrical connection (10) is an electrical connection according to any one of claims 1 to 12.

16. An exhaust system of an internal combustion engine comprising a jacket (100) having at least one opening (106) and an electrical connection (10) comprising a bushing (12) having a geometric center axis (14), an electrical conductor (16) passing through the bushing (12) along the geometric center axis (14) and an insulation layer (18) electrically insulating the bushing (12) from the electrical conductor (16), the electrical connection (10) being introduced into the jacket (100) through the opening (106) and fixedly attached to the jacket (100); characterized in that the exhaust system comprises an electrical connection (10) according to one of claims 1 to 12.

17. The exhaust system according to claim 16, characterized in that the electrical conductor (16) of the electrical connection (10) introduced into the jacket (100) through the opening (106) and fixedly attached to the jacket (100) is electrically connected to an electrical component (102) located inside the jacket (100).

18. The exhaust system according to claim 16 or 17, characterized in that the exhaust system comprises a catalytic converter (104), the jacket (100) being part of the catalytic converter (104) and housing an electrical component (102) in the form of a grid or a honeycomb body that is electrically heatable; the electrical conductor (16) of the electrical connection (10) introduced into the jacket (100) through the opening (106) and fixedly attached to the jacket (100) is electrically connected to the grid or honeycomb body inside the jacket (100).

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