IGNITIONER FOR A GAS GENERATOR AND METHOD FOR MANUFACTURING AN IGNITIONER

Description

[0001] The invention relates to an igniter for a gas generator and a method for producing an igniter.

[0002] Igniters are used in a gas generator to activate, in particular ignite, a gas-generating material contained therein, for example a pyrotechnic agent, by means of an electrical impulse.

[0003] Gas generators are used, for example, in vehicles, where they supply filling gas for inflatable gas bags, as micro gas generators to provide kinetic energy for seat belt tensioners, or act as an actuator in a safety system, such as an engine hood lifter or a separator for a battery connection.

[0004] Typically, such an igniter comprises a so-called pole body, also known as a header, which has two metallic, electrically conductive connecting pins and a holder that secures the two connecting pins. The two connecting pins are separated from each other by an electrically insulating medium.

[0005] The two connecting pins are connected by an electrically conductive bridge wire, which is in contact with a pyrotechnic igniter charge. This charge is housed in a cap and encapsulated by it. The pole body can be enclosed by a mounting section that allows the igniter to be mounted in the gas generator and can also provide an electrical connection for contacting the two connecting pins via a plug from outside the gas generator.

[0006] It is generally known to mount the polar body using a metal ring and to provide electrical insulation using a glass mass, which is initially present in liquid form in the metal ring and in which at least one of the connection pins is fixed, in particular by specifically cooling the liquid glass mass. Such polar bodies made of a metal ring with insulating glass feedthroughs are also known as GTMS headers (GTMS: Glass to Metal Seal). One known GTMS header is shown, for example, in US Pat. No. 5,404,263. Manufacturing is complex and expensive.

[0007] As an alternative, it is known to overmold two terminal pins with a plastic compound, which then secures the terminal pins and also forms the mounting section of the igniter. While the manufacturing process for these terminal bodies, which are essentially made of plastic, is inexpensive, ensuring the desired mechanical strength and tightness is complex.

[0008] From the document WO 2016 / 078634 A1, an igniter for a gas generator according to the preamble of claim 1 is known, which igniter has a pole body comprising at least one connection pin, a retaining ring and an insulating ring, wherein the insulating ring spaced the at least one connection pin from the retaining ring and electrically insulated therefrom, and wherein the retaining ring is made of a metal and the insulating ring is made of a plastic.

[0009] The object of the invention is to provide an igniter and a method for producing an igniter which overcome the disadvantages of the prior art and which create a mechanically stable and well-sealed igniter with a low-cost production.

[0010] This object is achieved with an igniter having the features of device claim 1 and / or method claim 7. An igniter for a gas generator has a pole body which comprises at least one connection pin, a retaining ring and an insulating ring, wherein the insulating ring spaces the at least one connection pin from the retaining ring and electrically insulates it from the latter, and wherein the retaining ring is made of a metal and the insulating ring is made of a plastic, and wherein the retaining ring, insulating ring and at least one connection pin are embossed in a embossing step in which the retaining ring, insulating ring and connection pin are firmly connected to one another without play by deforming at least the retaining ring.Due to this design, the pole body can initially be manufactured separately in a cost-effective process, whereby the use of the metal retaining ring enables a mechanically stable and airtight passage of the connection pin to the outside of the igniter.

[0011] Preferably, the retaining ring and the insulating ring have substantially the same dimensions along or parallel to a longitudinal axis of the igniter, so that the polar body forms a compact, geometrically simple component.

[0012] The pole body for the igniter for the gas generator comprises at least one connection pin, a retaining ring made of a metal and an insulating ring made of a plastic, wherein the insulating ring spaces the at least one connection pin from the retaining ring and electrically insulates it from the latter, and wherein the insulating ring forms a separately prefabricated component.

[0013] Such a pole body is designed such that, in plan view, the at least one connecting pin is surrounded by the insulating ring, and the insulating ring is surrounded by the retaining ring. Electrical insulation and a seal between the retaining ring and the at least one connecting pin are advantageously achieved solely by the insulating ring and its contact with the retaining ring and the at least one connecting pin.

[0014] The igniter according to the invention can preferably have a fastening section made of plastic, separate from the insulating ring, into which at least one connecting pin is partially embedded. This allows for subsequent partial embedding of the pole body in the fastening section, in particular by casting or injection molding, resulting in greater design flexibility and low manufacturing costs. To improve the mechanical connection and the sealing effect, an outer circumferential surface of the insulating ring and an inner circumferential surface of the retaining ring preferably have complementary structures that interlock. The structures can form a type of simple labyrinth structure and can have undercuts with respect to the longitudinal axis of the pole body or the igniter.

[0015] Alternatively or additionally, such complementary structures are also provided on an outer circumferential surface of the connection pin and an inner circumferential surface of the insulating ring.

[0016] The insulating ring is advantageously interlocked with both the retaining ring and the connecting pin via these structures, so that it cannot be displaced relative to the retaining ring and / or the connecting pin with respect to the longitudinal axis of the pole body or the igniter.

[0017] The insulating ring has, for example, a feedthrough opening through which an igniter-side end of the connecting pin, in particular a first connecting pin, extends, wherein preferably a further connecting pin, in particular a second connecting pin, is electrically conductively fastened to the retaining ring. This igniter-side end of the connecting pin ends essentially in the plane formed by the surface of the insulating ring and the retaining ring, wherein this refers in particular to the essentially overlapping surfaces of the insulating ring and the retaining ring, which are intended to accommodate, in a specific region, an electrically conductive element, in particular a bridge wire, which can activate a pyrotechnic ignition charge.The further connection pin, in particular the second connection pin, can preferably be fastened by welding or soldering to the axial end face of the retaining ring which is opposite the surface of the retaining ring which receives the bridge wire.

[0018] Normally, both connection pins are made of an electrically conductive material, usually a metal, although they may also be at least partially coated with an outer layer of gold.

[0019] According to the present invention, however, it is also possible for the insulating ring to have two through-openings through which the igniter-side ends of two adjacently arranged connecting pins, in particular a first and a second connecting pin, extend.

[0020] In the event that the insulating ring has only one feedthrough opening through which the igniter-side end of the connecting pin, in particular the first connecting pin, extends, the electrically conductive element, in particular a bridge wire with a specific resistance, is attached at one of its two ends to the igniter-side end of this connecting pin. The electrically conductive element can heat up considerably when current flows through it and ignite the adjacent pyrotechnic ignition charge. The other end of this electrically conductive element is electrically conductively connected to the retaining ring, in particular welded thereto. In this case, the further connecting pin, in particular the second connecting pin, is electrically conductively fixed to the retaining ring.

[0021] In the event that the insulating ring has two feedthrough openings through which the igniter-side ends of the adjacently arranged connection pins, in particular those of the first and second connection pins, extend, the other end of this electrically conductive element is directly electrically connected to the igniter-side end of the second connection pin, so that in this case the two igniter-side ends of the two connection pins are directly electrically connected to one another by the electrically conductive element.

[0022] In the present invention, the insulating ring only needs to be wide enough in the radial direction to provide sufficient electrical insulation. It is possible for the retaining ring to have a greater wall thickness in the radial direction than the insulating ring.

[0023] In a preferred embodiment, the insulating ring is a prefabricated component that is inserted between the retaining ring and the connecting pin. The insulating ring can, for example, be a separately manufactured component, such as an injection-molded, cast, or stamped part, or produced using a 3D printing process or an extrusion process. This allows for easy handling during assembly of the igniter or the pole body, for example, by providing the insulating ring as bulk material on a production line and then feeding it individually and without great effort.

[0024] It is also possible for at least one connection pin to be formed from two separate components, a first contact section and a second contact section, which are firmly connected to one another in an electrically conductive manner, in particular welded, soldered, or glued. In particular, the first contact section is surrounded or enclosed by the or an insulating ring at least partially along its longitudinal extent, wherein the second contact section is essentially free of such an enclosure. In this case, a connection pin as described above is therefore not formed from a single known elongated component made of metal, but rather comprises at least two components which are electrically conductively connected to one another and, as a whole, form a connection pin. The first and second contact sections are preferably made of the same material, in particular a metal known for use as a connection pin.The first and second contact sections are preferably designed as rectilinear, axially extending, rod-shaped or substantially cylindrical wire elements, wherein both contact sections preferably have complementary connecting surfaces or connecting contours in the region in which they are electrically connected to one another, so that they can be optimally connected, in particular welded, soldered, or glued, in this region. Advantageously, the first contact section has a planar surface on each of its two opposite end faces, which is formed substantially perpendicular to the longitudinal axis of the first contact section.The second contact section advantageously has a face with a planar surface at only one axial end, which is complementary to the face of the first contact section to which it is connected, in order to be optimally aligned with the first contact section. However, the second contact section has a rounded or dome-shaped end at the axially opposite end, which is suitable for connection to a connector or plug for electrically connecting the igniter to a control unit.

[0025] In summary, the first contact section is connected to the second contact section in axial alignment, so that a connection pin is formed which comprises the two contact sections and which essentially forms a continuous, longitudinally extending, rod-shaped or essentially cylindrical shape or contour.

[0026] The above-mentioned object is also achieved by a method for producing an igniter for a gas generator having the steps specified in claim 9. In this method for producing an igniter for a gas generator, the following steps are carried out: Providing at least one connection pin, a retaining ring made of a metal and an insulating ring made of a plastic, inserting the connection pin, the insulating ring and the retaining ring into one another so that the connection pin is surrounded by the insulating ring and the insulating ring is surrounded by the retaining ring, and stamping the retaining ring, insulating ring and connection pin in a stamping step in which the retaining ring, insulating ring and connection pin are firmly and play-freely connected to one another by deforming at least the retaining ring.

[0027] The retaining ring, insulating ring, and connecting pin are each separately prefabricated parts whose dimensions do not change significantly during the stamping step. In the axial and radial directions, the retaining ring and, if applicable, the insulating ring, in particular, can change their dimensions by approximately 10% to 30%. The connecting pin preferably deforms only slightly during the stamping step.

[0028] During the stamping step, an axial force can be applied to the retaining ring, the insulating ring, and the connecting pin. However, it is also possible to apply a radial force in addition. Generally, the stamping step involves joining, in particular pressing, the retaining ring, insulating ring, and connecting pin together. The stamping force can range from 5 N to 50 kN, for example, whereby the stamping step can comprise a single stamping stroke or any number of stamping strokes.

[0029] In the stamping step, a stamping die is moved onto the igniter-side upper side of the retaining ring, the insulating ring and the connection pin with sufficient impact force to deform these components.

[0030] The retaining ring and the insulating ring can be placed on a carrier which, in the stamping step, provides a counterforce to an axially moving stamping die which acts on the igniter-side surfaces of the retaining ring, the insulating ring and the igniter-side end of the connection pin.

[0031] The outer radius of the retaining ring preferably does not increase during the stamping step. A counterholder surrounding the retaining ring is preferably provided, which prevents the retaining ring from deflecting in the radial direction and from increasing the outer radius of the retaining ring.

[0032] If, as described above, the insulating ring has two separate openings, each with one end of a connecting pin protruding through it, both connecting pins are connected to the insulating ring and the retaining ring in the same stamping step. The basic procedure remains unchanged.

[0033] The above-mentioned object is also achieved by a method for producing an igniter for a gas generator having the steps specified in claim 11. In this method for producing an igniter for a gas generator, the following steps are carried out: Providing at least one first contact section, at least one second contact section, a retaining ring made of a metal, and an insulating ring made of a plastic; inserting the first contact section, the insulating ring, and the retaining ring into one another such that the first contact section is surrounded by the insulating ring and the insulating ring is surrounded by the retaining ring; stamping the retaining ring, the insulating ring, and the first contact section in a stamping step, in which the retaining ring, the insulating ring, and the first contact section are firmly and play-freely connected to one another by deforming at least the retaining ring; wherein, in particular in the stamping step, a force acting in the axial direction is applied to the retaining ring, the insulating ring, and the first contact section; and electrically connecting the second contact section to the first contact section, substantially axially aligned, by welding, soldering, or gluing.to form at least one connection pin from the first and second contact sections. ,

[0034] If, as described above, the insulating ring has two separate openings, each through which a first contact section protrudes, two first contact sections are connected to the insulating ring and to the retaining ring in the same stamping step. Subsequently, a second contact section is electrically connected to the respective first contact section, essentially axially aligned, by welding, soldering, or gluing, in order to form a connection pin from each of the first and second contact sections, so that the igniter has a total of two connection pins. The basic procedure remains unchanged.

[0035] As already described above, an outer peripheral surface of the insulating ring and an inner peripheral surface of the retaining ring preferably have complementary structures.

[0036] The same applies to an outer circumferential surface of the connection pin in the area of ​​the insulating ring as well as an inner circumferential surface of the insulating ring.

[0037] Before the stamping step, it is advantageous to maintain a gap between the insulating ring and the retaining ring large enough to allow the insulating ring and retaining ring to be inserted into each other without deformation, even though the structures do not need to be free of undercuts. There may also be some play between the insulating ring and the connecting pin after assembly and before the stamping step, so that these components can also be inserted into each other without deformation.

[0038] The shape, type and size of the structures between the insulating ring and the retaining ring and those between the connecting pin and the insulating ring can be selected to be the same or different.

[0039] The structures on the peripheral surfaces of the retaining ring and the connecting pin can be introduced into the respective surfaces, for example, by material-removing machining, such as machining, laser ablation, or chemically through etching or forming processes. It is also possible to use primary forming processes and create the structures directly during the production of the respective component. This is particularly preferred when manufacturing the insulating ring from plastic.

[0040] Any suitable geometry can be used for structuring, e.g., corresponding projections and recesses in the form of knobs and indentations with round, oval, elongated, or polygonal peripheral contours, as well as ribs and corresponding grooves that can run purely in the axial direction, purely in the radial direction, diagonally to these directions, or in a wavy manner. Thread forms and other spiral-shaped linear structures can also be used. The surface of the structuring can be rounded, straight, or angular.

[0041] During the stamping step, the structures of the insulating ring and the retaining ring are then preferably joined together without any gaps, in particular in a moisture-tight and gas- or air-tight manner, so that after the stamping step, the connection pin, the insulating ring and the retaining ring are directly connected to one another, firmly, without any gaps or play and, if possible, gas- or air-tight.

[0042] It is also conceivable to initially form the insulating ring, which is made of plastic and is therefore easier to deform, without structures or with structures that are flatter in the radial direction, so that the structures on the insulating ring only emerge during the embossing step or are formed in their final dimensions.

[0043] In general, the retaining ring and the connection pin can be manufactured by drawing, deep drawing, punching, forming, sintering, metal injection molding, electrochemical deposition processes or 3D printing.

[0044] It has proven advantageous if, prior to the stamping step, an axial length of the retaining ring is greater than an axial length of the insulating ring, wherein in particular the retaining ring and the insulating ring are axially aligned with one another such that the igniter-side upper side of the retaining ring projects beyond the igniter-side upper side of the insulating ring. As a result, the resulting excess material of the retaining ring can be used to displace the inner circumferential surface of the retaining ring radially inward, so that the structures of the retaining ring and insulating ring interlock. Preferably, the excess material is selected to be large enough to also cause a radially inward deformation of the insulating ring, which engages the structures on the inner circumferential surface of the insulating ring and on the outer circumferential surface of the connection pin.

[0045] The wall thickness of the insulating ring can be between 1 mm and 15 mm. The axial length of the insulating ring can be between approximately 1 mm and 10 mm.

[0046] The inner diameter of the retaining ring can, for example, be approximately 1 mm to 25 mm, while the outer diameter of the retaining ring can be between 1.5 mm and 50 mm. A wall thickness of 1 mm to 25 mm is conceivable. The height corresponds in particular to that of the insulating ring and can be selected between approximately 1 mm and 10 mm. An initial overhang of the retaining ring height, i.e., formed before the first stamping step, can be approximately 10% to 20% compared to the height of the insulating ring.

[0047] After the stamping step or after completion of several stamping steps, the igniter-side upper side of the retaining ring, insulating ring and connection pin generally forms an essentially flat and smooth surface.

[0048] However, it is possible to produce a raised structure on this igniter-side upper side of the pole body and in particular on the surface of the retaining ring, the insulating ring and / or the connection pin or the first contact section in the embossing step.

[0049] The raised structure can in particular be a web that runs between the connection pin and the retaining ring or, if two connection pins are provided that pass through the insulating ring, a web in the surface of the insulating ring between the two connection pins.

[0050] Preferably, in the case of the presence of only a single connection pin within the insulating ring, a further connection pin is electrically conductively fastened to the retaining ring, in particular by welding or soldering.

[0051] In the event that the insulating ring has only one through-hole through which a single connecting pin extends, an electrically conductive element, in particular a bridge wire, is arranged in an electrically conductive manner between the connecting pin and the retaining ring, in particular welded or soldered, as described above. Instead of a bridge wire, a printed circuit board, a chip element, a thick-film element, or a thin-film element can of course also be used, as is known from the prior art.

[0052] In the event that the insulating ring has two feedthrough openings through which two adjacently arranged connection pins extend, the electrically conductive element, in particular the bridge wire, is arranged between the two connection pins.

[0053] If a raised structure is provided, the electrically conductive element preferably rests on the raised structure, wherein the width of the raised structure is preferably many times greater than the width of the electrically conductive element in plan view, such that a projection of the raised structure is formed along the longitudinal extent of the electrically conductive element, so that a secure or sufficiently wide support of the electrically conductive element on the raised structure is ensured.

[0054] As mentioned above, the stamping step can involve multiple stamping strokes, in particular up to several hundred. This improves the surface quality and reduces surface roughness. Preferably, such multiple stamping steps are performed before mounting the electrically conductive element and before mounting another terminal pin on the retaining ring, in the case of only a single terminal pin within the insulating ring.

[0055] If necessary, multiple embossing strokes can also be made only in the area of ​​the raised structure.

[0056] It is also conceivable to create the raised structure only in such a re-embossing stroke after one or more first stamping strokes in which the connection pin, the insulating ring and the retaining ring were connected to each other.

[0057] The fully assembled polar body with the electrically conductive element is connected to a first cap filled with a compressed pyrotechnic igniter charge. The first cap can preferably be made of metal, for example steel, and can be filled with one or more different layers of a compressed pyrotechnic igniter charge. The above-described assembled polar body can be inserted or moderately pressed into the open end of such a pre-filled cap, wherein a circumferential side wall of the open end of the first cap preferably encloses the retaining ring of the polar body, in particular in the manner of a press fit, and is fastened radially to the retaining ring, in particular by welding. This ensures, in particular, a hermetic seal and a certain mechanical prestress or insulation of the pyrotechnic igniter charge.This requires close, intimate contact between the electrically conductive element and the pyrotechnic igniter charge. Placing the electrically conductive element on the raised structure can increase contact force and thus ensure good contact.

[0058] Such a prefabricated igniter with the above-described first metal cap can be used directly for installation in a gas generator housing, in particular in an outer housing of a gas generator, by being permanently installed, in particular welded, into such a housing. Preferably, such an igniter with an outer region of the first cap can be fitted into a receptacle of a metal gas pressure vessel in which a gas or gas mixture is stored at a pressure of 200 to 600 bar even in the idle state, i.e., in the non-actuated state, and can be welded gas-tight to this receptacle.

[0059] Furthermore, it is also possible for such a prefabricated igniter to have, in addition to the first metal cap, another cap, in particular a second outer cap, preferably made of an electrically insulating material such as plastic. Such a second cap can be placed or pressed directly onto the first cap and thereby essentially completely enclose the outer contour of the first cap, thereby forming a partial region of the outer contour of such a prefabricated igniter. In particular, such a second cap has the task of electrically insulating the prefabricated igniter from the outside.

[0060] In general, the term cap, with regard to the first and the second cap, means a component with a substantially cylindrical side wall, wherein the side wall is axially closed by a cap base and an opening of the cap is axially opposite the cap base.

[0061] After completion of the pole body using the method described above, after mounting the bridge wire on the pole body, and after attaching the first and second caps, the firmly connected assembly comprising two connecting pins, the insulating ring, and the retaining ring is preferably overmolded or cast with a fastening section made of a plastic, with at least the connecting pins being partially embedded in the fastening section. The openings or the edges of the openings of both caps, in particular also a portion of the axial side wall of the second cap, starting from its opening and extending to its cap base, can optionally also be embedded in the fastening section.

[0062] The second connection pin can either be guided through a feedthrough opening, in particular a second feedthrough, in the insulating ring and connected to the insulating ring in the stamping step and to the retaining ring by means of the insulating ring, or it can be welded to the retaining ring after the stamping step.

[0063] As already described above, the fastening section forms a fastening for fixing the igniter either in a separate igniter carrier which can be fastened in the gas generator or directly in the gas generator and additionally seals the polar body against moisture.

[0064] The overmolding or overmolding with the fastening section takes place in a separate step. Different plastic materials can be used for the insulating ring and the fastening section.

[0065] It is also conceivable to produce the fastening section in such a way that the polar body is connected to the gas generator by the casting or injection process, i.e. to cast or inject the fastening section into the gas generator.

[0066] The invention is described in more detail below using several exemplary embodiments with reference to the accompanying drawings. In the drawings: Figure 1a an igniter according to the invention for a gas generator in a schematic sectional view, produced by a method according to the invention; Figure 1b an assembly 11 comprising the igniter 10 according to the invention from Figure 1a , inserted into a component of an outer casing of a gas generator, manufactured according to a method according to the invention; Figures 2 to 4 Steps of manufacturing an igniter according to the invention by a method according to the invention, according to a first embodiment; Figure 4aa sectional view of an igniter according to the invention, produced by a method according to the invention, according to a variant; Figure 5 a schematic plan view of an igniter-side top side of a finished pole body of the igniter according to the invention produced by the method according to the invention; Figure 6 a finished pole body of an igniter according to the invention in a schematic sectional view according to a second embodiment, produced by a method according to the invention; Figure 7 the polar body Figure 6 in a schematic plan view of its igniter-side top side; Figure 8 a retaining ring, an insulating ring and an upper igniter-side end of a connection pin of a pole body of an igniter according to the invention in a schematic perspective view, before the start of production of the igniter in a method according to the invention, with a structuring according to a first variant; Figure 9 the connection pins of the pole body of the igniter according to the invention according to Figure 8 ; Figure 10 the components of the Figures 8 and 9 finished pole body, wherein the connecting pin, insulating ring and retaining ring have a first structuring; Figures 11 to 13 various schematic sectional views of the polar body from Figure 10 ; Figure 14 a schematic plan view of the igniter-side top of the polar body from Figure 10 ; Figure 15 a retaining ring, an insulating ring and an upper igniter-side end of a connection pin of a pole body of an igniter according to the invention before the start of production of the igniter in a method according to the invention, in a schematic perspective view, with a structuring according to a second variant; Figure 16 the two connection pins of the polar body according to Figure 15 ; Figures 17 to 19 various schematic sectional views of the components of the Figures 15 and 16manufactured polar body; Figure 20 a retaining ring, an insulating ring and an upper igniter-side end of a connection pin of a pole body of an igniter according to the invention before the start of production of the igniter in a method according to the invention, in a schematic perspective view, with a structuring according to a third variant; Figure 21 the two connection pins of the polar body according to Figure 20 ; Figures 22 to 24 various schematic sectional views of the components of the Figures 20 and 21 manufactured polar body; Figure 25 a retaining ring, an insulating ring and an upper igniter-side end of a connection pin of a pole body of an igniter according to the invention before the start of production of the igniter in a method according to the invention, in a schematic perspective view, with a structuring according to a fourth variant; Figure 26 the two connection pins of the polar body according to Figure 25 ; Figures 27 to 29 various schematic sectional views of the components of the Figures 25 and 26 manufactured polar body; Figure 30 a retaining ring, an insulating ring and an upper igniter-side end of a connection pin of a pole body of an igniter according to the invention before the start of production of the igniter in a method according to the invention, in a schematic perspective view, with a structuring according to a fifth variant; Figure 31 the two connection pins of the polar body according to Figure 30 ; Figures 32 to 34 various schematic sectional views of the components of the Figures 30 and 31 manufactured polar body; Figures 35 to 44 schematic representations of further variants for structuring the retaining ring, the insulating ring and / or the connection pin; Figures 45a to 45d Variants for structuring the retaining ring and the insulating ring or the insulating ring and the connection pin; Figures 46 to 48Steps of manufacturing an igniter according to the invention by a method according to the invention, according to a further embodiment; and Figure 48a a sectional view of an igniter according to the invention, produced by a method according to the invention, according to a variant.

[0067] Figure 1a shows an igniter 10 according to the invention, which comprises a pole body 14, which in turn is composed of two electrically conductive connecting pins 16, 18, in particular of a first connecting pin 16 and a second connecting pin 18, and a metal retaining ring 20 and a plastic insulating ring 22 (see in detail Figures 8 to 34 ). The polar body 14 has an igniter-side upper side 28 (see e.g. Figure 4), whereby this upper side 28 can also be understood as a corresponding igniter-side upper side 28 of the retaining ring 20, igniter-side surface 28 of the insulating ring 22, and igniter-side upper side 28 of an igniter-side end 26 of the connecting pin 16. In other words, the igniter-side upper side 28 of the pole body 14 can also be understood as a summary of the individual corresponding igniter-side upper sides formed there, namely those of the retaining ring 20, the insulating ring 22, and the igniter-side end 26 of the connecting pin 16. For the sake of simplicity, the abbreviated term "upper side" is sometimes used below for the term "igniter-side upper side." In the example as in Figure 1aAs shown, an electrically conductive element 24 having a specific electrical resistance, which is designed in particular as a bridge wire, is also considered to belong to the pole body 14, wherein the electrically conductive element 24 extends between the upper (in the figures) igniter-side end 26 of the connection pin 16 and the igniter-side upper side 28 of the retaining ring 20.

[0068] The igniter-side end of the pole body 14 and in particular the entire upper side 28 of the retaining ring 20, the insulating ring 22, and the end 26 of the connecting pin 16 are completely covered by a first cap 31, preferably made of metal, which accommodates an igniter charge 32, in particular a pyrotechnic igniter charge, within its interior. The igniter charge 32 is in direct contact with the electrically conductive element 24 and with the upper side 28 of the pole body 14.

[0069] The electrically conductive element 24 is, for example, a bridge wire as is conventionally known, but could also be another component which can be heated by current flow between the two connection pins 16, 18 to such an extent that it can ignite the ignition charge 32.

[0070] A second cap 30, preferably made of a non-electrically conductive material such as plastic, is placed or pressed onto the first cap 31 in direct contact with the latter. The second cap 30 essentially completely encloses the outer contour of the first cap 31 and thus also forms an outer cap.

[0071] The igniter 10 also has a fastening section 34, which here is made of a plastic and surrounds a central section of the two connection pins 16, 18, so that these are partially embedded in the plastic material of the fastening section 34 and also fixed by it. Likewise, a peripheral edge of the second cap 30, in particular a free edge thereof, and a portion of an adjoining axial side wall of the second cap 30 are completely embedded in the material of the fastening section 34 and sealed from the environment by the latter.

[0072] The retaining ring 20, the insulating ring 22, the igniter-side end 26 of the connecting pin 16 as well as the electrically conductive element 24 and the ignition charge 32 are here completely surrounded by the second cap 30 and the fastening section 34 and are hermetically sealed, in particular air-tight or gas-tight, from the environment.

[0073] In this example, an igniter-side end 38 of the second connection pin 18 extends only to the side of the retaining ring 20 remote from the igniter and is electrically connected there, for example, by welding or soldering. The "igniter-side" of the retaining ring 20 refers to the side of the retaining ring 20 that is longitudinally axially opposite the igniter-side top side 28 of the retaining ring 20, to which the electrically conductive element 24 is attached. Specifically, the igniter-side side of the retaining ring 20 is a bottom side 46 of the retaining ring 20.

[0074] The insulating ring 22 is made of an electrically non-conductive plastic material and spatially separates the igniter-side end 26 of the connecting pin 16 from the metal retaining ring 20, and also electrically insulates these components from each other. The only electrical contact between the retaining ring 20 and the connecting pin 16 is via the electrically conductive element 24 in a non-activated state of the igniter 10, in which the electrically conductive element 24 is (not yet) activated, as shown in Figure 1a shown.

[0075] The retaining ring 20 radially surrounds the insulating ring 22, wherein in the radial direction r the two components directly abut or contact one another over their entire corresponding circumference. In other words, the retaining ring 20 bears with its radially circumferential surface, with respect to its inner diameter, against the radially circumferential surface of the insulating ring 22, with respect to its outer diameter. Furthermore, the insulating ring 22 radially surrounds the end 26 of the connecting pin 16. These components also directly abut or contact one another over their entire corresponding circumference in the radial direction r. In other words, the insulating ring 22 bears with its radially circumferential surface, with respect to its inner diameter, against the radially circumferential surface of the connecting pin 16, with respect to its outer diameter.

[0076] The fastening section 34 here forms a separate component, in particular from the insulating ring 22, which, as described further below, is also manufactured in a separate work step.

[0077] Figure 1b shows an assembly 11 comprising the igniter 10 according to the invention, as in Figure 1ashown, inserted into a housing 12 of a gas generator (not shown in more detail). The housing 12 shown can also be understood as a component of a housing of such a gas generator or at least as a partial region of such a housing. In particular, the housing 12 shown can represent a partial region of an outer housing of such a gas generator, wherein the housing 12 is preferably made of metal and the igniter 10 is firmly held in the housing 12, in particular by a flanged or bent collar-like extension of the housing 12. The housing 12 itself can also be inserted into a further housing part (not shown), for example into a particularly tubular outer housing of such a gas generator, in particular welded to an end region of such a housing.

[0078] Alternatively, it is also possible to connect only the polar body 14 of the igniter 10 directly to the housing 12 of the gas generator by means of the fastening section 34, by attaching the polar body 14 to or into the housing 12, in particular into an end opening thereof, by means of plastic injection molding. In this case, the fastening section 34 then represents a portion of such a plastic overmolding or plastic injection of the polar body 14 into the housing 12. In this case, a flanged or bent collar-like extension of the housing 12 described above can be omitted, since the polar body 14 can be held in place simply by injecting the fastening section 34 into the housing 12.

[0079] Instead of the gas generator, a so-called micro gas generator or actuator, which is used, for example, to lift the hood of a vehicle for a personal protection system, can also be understood here, wherein the housing 12 shown then represents a corresponding housing or housing component of such a micro gas generator or actuator.

[0080] In the housing 12 of the gas generator, a plug receptacle 36 is formed, via which the free ends of the two connection pins 16, 18 can be electrically contacted in order to activate the igniter 10, i.e. to trigger it in such a way that the ignition charge 32 can be ignited and the gas generator can be used as intended.

[0081] In the Figures 2 to 5 is an inventive manufacturing process for the Figure 1a illustrated lighter 10.

[0082] In this case, the retaining ring 20, the insulating ring 22 and the connecting pin 16, in particular the first connecting pin 16, are separate, prefabricated components, each of which can be manufactured independently of one another and provided for the manufacturing process of the igniter 10 according to the invention.

[0083] The retaining ring 20 has a ring shape with a through-hole 39a. The outer circumference of the retaining ring 20 is circular here, but can also have any other contour.

[0084] The insulating ring 22 is also ring-shaped with a single through-opening 39b.

[0085] In general, a wall thickness of the insulating ring 22 in the radial direction r can be selected to be smaller, equal to or larger than that of the retaining ring 20, so that the wall thickness of the insulating ring 22 can be designed independently of the wall thickness of the retaining ring.

[0086] The three components retaining ring 20, insulating ring 22 and connection pin 16 are assembled as shown in Figure 2 shown inserted into one another, so that the insulating ring 22 is arranged within the through-opening 39a of the retaining ring 20 and the end 26 of the connecting pin 16 is arranged within the through-opening 39b. In this example, the retaining ring 20 and the insulating ring 22 are concentric with the igniter-side end 26 of the connecting pin 16 or concentric with respect to the first connecting pin 16. A longitudinal axis A of the end 26 of the connecting pin 16, which can also be understood as the longitudinal axis A of the first connecting pin 16, coincides with a longitudinal axis A of the entire igniter 10 or is aligned parallel to it, as also in Figure 1a and Figure 1b can be seen.

[0087] Along this longitudinal axis A or parallel thereto, the longitudinal extent h 1 of the retaining ring 20 is selected to be somewhat larger than the longitudinal extent h 2 of the insulating ring 22, so that here an axial length difference or a projection of the retaining ring 20 results, which can amount to approximately 1 - 15%, based on the longitudinal extent h 2 of the insulating ring 22. The three components retaining ring 20, insulating ring 22 and connection pin 16 are arranged relative to one another, in particular axially relative to one another, such that the projection of the retaining ring 20 is formed on the side of the igniter-side end 26 of the connection pin 16 or that the igniter-side upper side 28 of the retaining ring 20 projects beyond the igniter-side upper side 28 of the insulating ring 22 and that of the connection pin 16 opposite an axial direction a. The axial direction a is essentially parallel to the longitudinal axis A of the connection pin 16 or.to the longitudinal axis A of the entire igniter 10 and points in the direction of the end of the connection pin 16 which is axially opposite the igniter-side end 26 of the connection pin 16.

[0088] The retaining ring 20, the insulating ring 22 and the igniter-side end 26 of the connecting pin 16 are inserted into each other with enough play or distance Δx 1 , Δx 2 that none of these components is deformed (see for example Figure 2 ). In other words, these three components—retaining ring 20, insulating ring 22, and connecting pin 16—are positioned with sufficient radial spacings Δx 1 , Δx 2 relative to one another, allowing the three components to be inserted into one another without deformation. In other words, a clearance fit can be formed between the three components when they are provided or inserted into one another.

[0089] As in Figure 3 shown, the Figure 2The assembly shown is placed on a carrier 40 which has an opening through which the connecting pin 16 projects, the connecting pin 16 being fixed in its position such that its igniter-side upper side 28 is at the same height as the igniter-side upper side 28 of the insulating ring 22. A counter-holder 42 encloses the retaining ring 20 in the circumferential direction and prevents any deflection or mobility or material compression of the retaining ring 20 in the radial direction r. Using a stamping die 44 which can be moved along the axial direction a, a force F acting in the axial direction a is applied to the retaining ring 20, the insulating ring 22 and the end 26 of the connecting pin 16. This can take place in a single pulse or any number of individual pulses or stamping steps with the previously described force application.By repeated application of force, the igniter-side upper side 28 of the retaining ring 20, the insulating ring 22 and the igniter-side end 26 of the connecting pin 16, i.e. the entire igniter-side upper side 28 of the pole body, can be smoothed more and thus a higher surface quality can be achieved.

[0090] In this example, the force F is applied in a pulsed or sudden manner over a short period of time. A high force can be applied over a short period of time. The force F can be up to approximately 50 kN, but can also be selected to be lower, e.g., down to approximately 5 N. The magnitude of the force F depends in particular on the dimensions of the igniter 10 and its components.

[0091] By applying such a force or by means of such a stamping step, a joining or joining, in particular a pressing, of the retaining ring 20, the insulating ring 22 and the connecting pin 16 with one another is achieved.

[0092] Due to the force described above, the material of the retaining ring 20 flows radially inwards or is pressed or displaced in the radial direction r and thereby also pushes the insulating ring 22 radially inwards in the direction of the connection pin 16. In the process, the spaces (see Figure 2 ) between insulating ring 22 and retaining ring 20 and insulating ring 22 and connection pin 16 is completely closed. In particular, the material of the retaining ring 20 that protrudes beyond the dimension h 2 fills at least a partial area of ​​the intermediate space between insulating ring 22 and retaining ring 20. Both the diameter of the through-opening 39a of the retaining ring 20 and the diameter of the through-opening 39b of the insulating ring 22 are reduced in this stamping step or are successively reduced accordingly in the case of several stamping steps.

[0093] It would also be possible, in the stamping step described above or optionally or selectively in subsequent repeated stamping steps, to apply not only a purely axially acting force F, but also, for example, to additionally apply a radially inwardly acting force which is directed substantially perpendicular to the outer wall of the counterholder 42 from radially outside to radially inside.

[0094] After completion of the stamping step or several stamping steps, the igniter-side end 26 of the connecting pin 16, the insulating ring 22, and the retaining ring 20 are firmly connected to each other without play. The connection between the individual components is particularly moisture-tight, airtight, and gas-tight.

[0095] Figure 4 shows the firmly connected assembly consisting of retaining ring 20, insulating ring 22 and connection pin 16.

[0096] As in Figure 4As can be seen, in a further work step the electrically conductive element 24 is arranged on the upper side 28 of the pole body 14 and is firmly and electrically conductively connected, in particular welded or soldered, to the connection pin 16 and the retaining ring 20.

[0097] In addition, the igniter-side end 38 of the second connection pin 18 can be welded to the underside 46 of the retaining ring 20. This is Figure 4 not explicitly shown, but there is merely indicated by the reference numeral 46 a possible location on the underside 46 of the retaining ring 20, to which the second connection pin 18 can be attached accordingly. Figure 1a a possible embodiment of the igniter according to the invention with a corresponding second connection pin 18, attached to the underside 46 of the retaining ring 20, is shown.

[0098] During the embossing step or several repeated embossing steps, the roughness of the upper side 28 of the pole body 14 is reduced as much as possible, resulting in a surface with a high surface quality. The upper side 28 can form a single smooth plane.

[0099] However, it is also possible to provide the upper side 28 with a raised structure 45, wherein the raised structure 45 is also produced in the embossing step or by several embossing steps carried out one after the other, in particular by an embossing die 44 adapted to the contour of the raised structure 45. Such a raised structure 45 is shown in Figure 4a shown.

[0100] It would also be possible to use a second stamping die 44 that acts on the upper side 28 only in the area of ​​the raised structure 45 in order to create a particularly low roughness there. The raised structure 45 is, for example, a web that extends exclusively below the conductive element 24 from the igniter-side end 26 of the connection pin 16 to the retaining ring 20 and on which the electrically conductive element 24 rests.

[0101] Figures 6 and 7 show a second embodiment of a polar body 14' of the igniter 10.

[0102] In contrast to the embodiment just described, the insulating ring 22' has two through-openings 39b through which the igniter-side end 26 of the first connection pin 16 and the igniter-side end 38 of the second connection pin 18 protrude. In this case, the second connection pin 18 is not attached to the underside 46 of the retaining ring 20, but extends to the top side 28 of the pole body 14' or the insulating ring 22'. In this case, the electrically conductive element 24 connects the igniter-side top sides of the two connection pins 16, 18 to one another on the top side 28 of the pole body 14'.

[0103] The retaining ring 20 can be designed identically to the first embodiment. It is possible to slightly increase the diameter of the retaining ring 20 and the insulating ring 22' compared to the first embodiment.

[0104] Here too, a raised structure can be provided below the electrically conductive element 24.

[0105] The contour of an outer peripheral surface 48 (see Figure 2 ) of the insulating ring 22 (and analogously of the insulating ring 22') corresponds in its shape essentially to the contour of an inner circumferential surface 50 of the feedthrough opening 39a of the retaining ring 20. Likewise, a contour of an outer circumferential surface 52 of the igniter-side end 26 of the connection pin 16 corresponds in its shape essentially to the contour of an inner circumferential surface 54 of the respective feedthrough opening 39b of the insulating ring 22, 22'. The contours can be essentially circular in plan view, but can also have other shapes.

[0106] The surfaces or peripheral surfaces 48, 50, 52, 54 are provided with structures 56a, 56b, 56c, 56d according to the variants shown in Figures 8 to 45.

[0107] The directly adjacent surfaces, i.e. the outer circumferential surface 48 of the insulating ring 22 and the inner circumferential surface 50 of the retaining ring 20 as well as the outer circumferential surface 52 of the connection pin 16 and the inner circumferential surface 54 of the insulating ring 22, each have complementary structures 56b, 56a and 56d, 56c, respectively, which are designed such that they can interlock in the radial direction r.

[0108] The structures 56a, 56b between the retaining ring 20 and the insulating ring 22 can have the same shape as the structures 56c, 56d between the insulating ring 22 and the connection pin 16, but different shapes can also be selected for these structures.

[0109] During the stamping step, the structures 56a, 56b and 56c, 56d of all structured surfaces 48, 50, 52, 54 are radially joined together so that the respective structures interlock, particularly without play. In this way, the retaining ring 20, the insulating ring 22, and the first connecting pin 16 are immovably and firmly connected to one another in the axial direction a and in the circumferential direction, i.e., radially all the way around.

[0110] Figure 10 shows the finished pole body 14 after the stamping step and after welding the second connection pin 18 to the retaining ring 20. In the finished pole body 14, the structures 56a, 56b, 56c, 56d are not visible from the outside.

[0111] The Figures 11 to 13 show how, after the embossing step, the structures 56a, 56b, 56c, 56d interlock in the finished polar body 14.

[0112] In this example, all structures 56a, 56b, 56c, 56d consist of circumferentially or radially extending ribs that are evenly spaced apart in the axial direction a and project in the radial direction r. On opposing surfaces 48, 50 and 52, 54, the ribs naturally meet grooves formed between the ribs.

[0113] All structures 56a, 56b, 56c, 56d extend essentially over the entire axial length of the respective surface 48, 50, 52, 54.

[0114] Figure 12 shows an enlarged section of Figure 11. Figure 14 clarifies the cutting direction of the Figures 11 and 13 .

[0115] Analogous to the embodiment just described, the Figures 15 to 19 a polar body 14 with a differently formed structure 56a, 56b, 56c, 56d.

[0116] Here, the structuring is formed by hemispherical recesses and projections that are opposite one another. Here, too, the structuring 56a, 56b between the retaining ring 20 and the insulating ring 22 is selected to be the same as the structuring 56c, 56d between the insulating ring 22 and the connecting pin 16.

[0117] The Figures 20 to 24 show a further variant of the structuring 56a, 56b, 56c, 56d. In this example, the arrangement of the recesses and projections is reversed or complementarily inverse compared to the last described example.

[0118] While in the example just described the recesses were provided on surfaces 50 and 52, here the recesses are formed on surfaces 48 and 54.

[0119] For the method according to the invention, the assignment of the respective structures 56a, 56b, 56c, 56d to the surfaces 48, 50, 52, 54 as well as the exact shape of the respective selected structures is of secondary importance.

[0120] The Figures 25 to 29 The example shown for the structurings 56a, 56b, 56c, 56d represents a knurling structure which is formed on all four surfaces 48, 50, 52, 54.

[0121] The Figures 30 to 34 Finally, a structuring is shown which is designed in the form of ribs of the structurings 56b, 56c running in the axial direction a and projecting in the radial direction r and corresponding depressions 56a, 56d.

[0122] As shown here, some of the structures may be formed only in the metal parts of the retaining ring 20 and the connecting pin 16 and may be missing from the insulating ring 22. Here, the complementary structures only emerge during the stamping step, when the material of the retaining ring 20 or the connecting pin 16 digs into the insulating ring 22 due to the pressing force.

[0123] The Figures 35 to 44 show further examples of structures which, for reasons of clarity, are only designated with the reference number 56 and which can each be designed as a depression or as a raised structure on the individual surfaces 48, 50, 52, 54.

[0124] All different structurings 56 can, of course, be interchanged at will at the discretion of the person skilled in the art. Likewise, other suitable structuring patterns can, of course, be used.

[0125] In general, the individual components of the structures 56 can merge into one another or be separated from one another and, in particular, can be designed in the form of points or lines.

[0126] In the Figures 45a to 45d It is once again illustrated how the structures 56a, 56b and 56c, 56d of the surfaces 48, 50 and 52, 54 are formed with complementary projections and depressions so that they interlock without play after the embossing step.

[0127] It is also conceivable to manufacture the insulating ring 22 from a suitable plastic material in an injection molding or casting process by filling the plastic material into a gap between the inner peripheral surface 50 of the retaining ring 20 and the outer peripheral surface 52 of the end 26 of the connection pin 16. In this case, the injection molding or casting step would replace the stamping step.

[0128] In all the examples shown, instead of an insulating ring 22 with only one through-opening 39b for the igniter-side end 26 of the connection pin 16, an insulating ring 22' with two through-openings 39b can of course be used, so that the igniter-side end 38 of the connection pin 18 is also passed through the insulating ring 22'.

[0129] After the pole body 14, 14' is completed and the conductive element 24 is mounted, the first cap 31 and the second cap 30 are placed on the top side 28 of the pole body 14, and the resulting assembly is provided with the fastening section 34 by casting or injection molding in a separate step to complete the igniter 10.

[0130] In the Figures 46 to 48a Another manufacturing method according to the invention for an igniter according to the invention is illustrated. In this case, the igniter according to the invention essentially corresponds to the Figure 1aThe igniter shown here is similar, but here one or both connecting pins are designed to run straight along their entire axial length. In other words, there is advantageously no curvature or bending along the longitudinal axis of the connecting pin(s).

[0131] The representations in the Figures 46 to 48a essentially correspond to the Figures 2 to 4a The main difference in this regard is the Figures 46 to 48ain that the connecting pin 16 shown there is constructed from two components, namely a first contact section 17a and a second contact section 17b. Both contact sections 17a, 17b are designed as rectilinear, longitudinally extending metal components. These are essentially cylindrical wire elements that are connected to one another at one of their end faces, in particular welded, soldered, or glued, and are formed from similar or identical suitable metallic materials as the one-piece connecting pin 16 described above.

[0132] The following description is limited to the Figures 46 to 48a on the essential differences to the ones described above Figures 2 to 4a . Thus, Figure 46a retaining ring 20, insulating ring 22 and a first contact section 17a with a longitudinal axis A as separate, prefabricated components, each of which can be manufactured independently of one another and provided for the manufacturing process of the igniter 10 according to the invention. Here, too, these separate components are assigned to one another, as already in Figure 2 shown, however, the axial length of the first contact section 17a corresponds to the axial extent of the insulating ring 22 or that of its through-opening 39a.

[0133] The three components retaining ring 20, insulating ring 22 and first contact section 17a are inserted into each other as shown in Figure 46shown. Here, too, the retaining ring 20 protrudes on the side of the igniter-side end 26 of the first contact section 17a, or the igniter-side upper side 28 of the retaining ring 20 projects beyond the igniter-side upper side of the insulating ring 22 and the first contact section 17a. On the opposite side, i.e., on the igniter-side underside of the retaining ring 20, however, the first contact section 17a terminates essentially planar with the retaining ring 20. In other words, there is no axial protrusion of the first contact section 17a on the igniter-side underside of the retaining ring 20.

[0134] As in Figure 47 The Figure 46The assembly shown is placed on a carrier 40, surrounded by a counterholder 42 and with an embossing die 44 which can be moved along the axial direction a, a force F acting in the axial direction a is applied to the retaining ring 20, the insulating ring 22 and the corresponding end of the first contact section 17a, which in the finished igniter corresponds to the end 26 of the connection pin 16.

[0135] The representation in Figure 47 also directly discloses a decisive advantage of the above-described embodiment according to the Figures 46 to 48a , namely that such a production, in particular an embossing or embossing process by means of the embossing die 44, is significantly simplified and also more efficient than is the case with an embodiment or a corresponding production of an igniter according to Figures 2 to 4a is the case. By using here ( Figure 47 ) the carrier 40 does not have to have an opening to accommodate an axially projecting connection pin 16 ( Figure 3 ) eliminates the need for complex positioning and fixing, as is the case for the axially protruding connection pin 16 (according to Figure 3 ) is the case.

[0136] After completion of the embossing step or several embossing steps according to Figure 47 The first contact section 17a, the insulating ring 22, and the retaining ring 20 are firmly connected to one another without play. The connection between the individual components is particularly moisture-tight, airtight, and gas-tight.

[0137] Figure 48shows a corresponding, firmly connected assembly comprising retaining ring 20, insulating ring 22, and first contact section 17a. However, in a further manufacturing step, a second contact section 17b is electrically conductively connected to the first contact section 17a, essentially axially aligned therewith, in order to produce a first connection pin 16, which comprises both contact sections 17a, 17b. Specifically, the first contact section 17a is essentially cylindrical and straight and comprises, at its opposite ends, two end faces or end surfaces that are aligned essentially parallel to one another and perpendicular to the longitudinal axis A of the first contact section 17a, one of these end faces already representing the igniter-side end 26 of the subsequently completed first connection pin 16. The second contact section 17b is now connected or fastened to the opposite end face of the first contact section 17a.For this purpose, the second contact section 17b has a correspondingly complementary end face, in particular a planar surface also aligned perpendicular to the longitudinal axis of the second contact section 17b, so that a correspondingly simple connection of the two contact sections 17a, 17b by welding, soldering or gluing is possible. The second contact section 17b has a rounded, dome-shaped contour at its opposite end, which is suitable for receiving a known plug (not shown) in order to be connected to a known control unit (not shown). In short, the two contact sections 17a, 17b, which are electrically conductively connected to one another, form a first connection pin 16, as shown, for example, in FIG. Figure 4 is shown as a one-piece component.

[0138] In addition, regarding the Figure 48 similar or analogous to the execution of the Figure 4As described above, an igniter-side end 38 of a second connection pin 18 is welded to the underside 46 of the retaining ring 20. This is Figure 48 not explicitly shown, but there is merely indicated by the reference number 46 a possible location on the underside 46 of the retaining ring 20 at which the second connection pin 18 can be fastened accordingly.

[0139] In addition, it is Figure 48a It is also possible for the upper side 28 to be provided with a raised structure 45, wherein the raised structure 45 is also produced in the embossing step or by several embossing steps carried out one after the other, in particular by an embossing die 44 adapted to the contour of the raised structure 45.

[0140] The main advantage of an igniter produced by a process according to the Figures 46 to 48aIn other words, the required finished length of a connection pin must only be realized or manufactured at a stage essentially at the end of the igniter manufacturing process. During the upstream manufacturing process, there is no need to handle a connection pin whose axial length is already finished. Advantageously, instead of a finished connection pin, a first contact section can be used that is optimally adapted to the other surrounding components, particularly with regard to its longitudinal extent, in order to achieve more effective and cost-effective upstream manufacturing processes.

Claims

1. An igniter for a gas generator, comprising a pole body (14; 14') having at least one connection pin (16, 18), a retaining ring (20) and an insulation ring (22), wherein the insulation ring (22) spaces the at least one connection pin (16, 18) apart from the retaining ring (22) and electrically insulates it from the same, and wherein the retaining ring (20) consists of a metal and the insulation ring (22) consists of a plastic, characterized in that said retaining ring (20), said insulation ring (22), and at least one connection pin (16, 18) are compressed together during a compression step, during which the retaining ring (20), the insulation ring (22), and the connection pin (16, 18) are directly connected to one another securely, without gaps and play, at least by deformation of the retaining ring (20).

2. The igniter according to claim 1, characterized in that the igniter comprises a fastening portion (34) made from plastic which is separate from the insulation ring (22) and into which at least portions of the at least one connection pin (16, 18) are embedded.

3. The igniter according to any one of the preceding claims, characterized in that an outer peripheral surface (48) of the insulation ring (22) and an inner peripheral surface (50) of the retaining ring (20) and / or an outer peripheral surface (52) of the connection pin (16) and an inner peripheral surface (54) of the insulation ring (22) have complementary textures (56b, 56a, 56d, 56c).

4. The igniter according to any one of the preceding claims, characterized in that the insulation ring (22) includes a through-opening (39b) through which an igniter-side end (26) of the connection pin (16) extends, wherein preferably another connection pin (18) is fastened to the retaining ring (20) in an electrically conducting manner.

5. The igniter according to any one of the preceding claims, characterized in that the insulation ring (22) includes two through-openings (39b) through which the igniter-side ends (26, 38) of two juxtaposed connection pins (16, 18) extend.

6. The igniter according to any one of the claims 1 to 5, characterized in that at least one connection pin (16, 18) is formed of two separate component parts, a first contact portion (17a) and a second contact portion (17b), which are tightly connected, especially welded, soldered or glued, to each other in an electrically conducting manner.

7. A method for producing an igniter (10) for a gas generator, especially according to any one of the preceding claims, comprising the steps of: - providing at least one connecting pin (16, 18), a retaining ring (20) consisting of a metal and an insulation ring (22) consisting of a plastic, - fitting the connecting pin (16, 18), the insulation ring (22) and the retaining ring (20) inside one another so that the connecting pin (16, 18) is surrounded by the insulation ring (22) and the insulation ring (22) is surrounded by the retaining ring (20), and - compressing the retaining ring (20), the insulation ring (22) and the connection pin (16, 18) in a compression step in which the retaining ring (20), the insulation ring (22) and the connecting pin (16, 18) are connected to one another securely and free from play while at least the retaining ring (20) is deformed, and wherein in the compression step a force (F) acting in the axial direction (a) is applied to the retaining ring (20), the insulation ring (22) and the first connecting pin (16, 18).

8. The method for producing an igniter (10) for a gas generator, especially according to claim 7, comprising the steps of: - providing at least a first contact portion (17a), at least a second contact portion (17b), a retaining ring (20) consisting of a metal and an insulation ring (22) consisting of a plastic, - fitting the first contact portion (17a), the insulation ring (22) and the retaining ring (20) inside one another so that the first contact portion (17a) is surrounded by the insulation ring (22) and the insulation ring (22) is surrounded by the retaining ring (20), - compressing the retaining ring (20), the insulation ring (22) and the first contact portion (17a) in a compression step in which the retaining ring (20), the insulation ring (22) and the first contact portion (17a) are connected to one another securely and free from play while at least the retaining ring (20) is deformed, wherein especially in the compression step a force (F) acting in the axial direction (a) is applied to the retaining ring (20), the insulation ring (22) and the first contact portion (17a), and - connecting the second contact portion (17b) in an electrically conducting manner to the first contact portion (17a), substantially in axial alignment, by welding, soldering or gluing, to form at least one connection pin (16) from the first and second contact portions (17a, 17b).

9. The method according to any one of the claims 7 to 8, characterized in that an outer peripheral surface (48) of the insulation ring (22) and an inner peripheral surface (50) of the retaining ring (20) have complementary textures (56b, 56a), and in that before the compression step a distance (Δx1) between the insulation ring (22) and the retaining ring (20) is so large that the insulation ring (22) and the retaining ring (20) can be fitted inside each other without being deformed.

10. The method according to claim 9, characterized in that in the compression step the textures (56a) of the insulation ring (22) and the retaining ring (20) are nested in a gap-free, especially gastight, manner.

11. The method according to any one of the claims 7 to 10, characterized in that, before the compression step, an axial length (h1) of the retaining ring (20) is larger than an axial length (h2) of the insulation ring (22), wherein especially the retaining ring (20) and the insulation ring (22) are axially aligned relative to each other so that the igniter-side upper side of the retaining ring (20) projects from the igniter-side upper side of the insulation ring (22).

12. The method according to any one of the claims 7 to 11, characterized in that in the compression step a raised structure (45) is produced on the igniter-side upper side (28) of the pole body (14; 14') comprising the retaining ring (20), the insulation ring (22) and the connection pin (16) and, resp., the first contact portion (17a).

13. The method according to any one of the claims 7 to 12, characterized in that the compression step is repeated several times.

14. The method according to any one of the claims 7 to 13, characterized in that, in case merely one single connection pin (16) is present within the insulation ring (22), another connection pin (18) is fastened, especially by welding or soldering, in an electrically conducting manner.

15. The method according to any one of the claims 7 to 14, characterized in that an electrically conductive element (24), especially a bridge wire, is arranged, especially welded or soldered, between the connection pin (16) and the retaining ring (20) in an electrically conducting manner.

16. The method according to any one of the claims 7 to 15, characterized in that the tightly connected subassembly consisting of two connection pins (16, 18), the insulation ring (22) and the retaining ring (20) is surrounded by injection-molding or casting with a fastening portion (34) made from a plastic into which at least portions of the connection pins (16, 18) are embedded.