Method for producing a ring- or plate-shaped element

Abstract

A method for manufacturing a ring- or plate-shaped element for a metal-fixing material feedthrough, for devices exposed to high pressures, preferably airbag igniters or seatbelt tensioners, with a through-opening, wherein a blank (1000) made of a wire-like material is provided and the blank (1000) is subjected to machining such that the through-opening (1070) is introduced into the ring- or plate-shaped element (1010) formed from the blank (1000) by punching with a punching tool after machining the ring- or plate-shaped element (1010), characterized in that the machining of the blank (1000) comprises the introduction of a clearance area (1050), wherein flow lines (1500) in the blank (1000) in an area (1600) which is connected to the through-opening (1070),the release area (1050) and rounded edges adjacent to the forming process are bent and run parallel to an axis of the through-opening (1070) outside the area (1600).

Description

[0001] The invention relates to a method for manufacturing a ring- or plate-shaped element, in particular for a metal fixing material feedthrough, especially for devices that are exposed to high pressures, preferably igniters of airbags or belt tensioners, and a method for manufacturing a metal fixing material feedthrough.

[0002] Metal-fixed feedthroughs are known in various designs from the prior art. These feedthroughs are vacuum-tight fusions of fixative materials, particularly glass, glass-ceramics, or plastics, within metals. The metals act as electrical conductors. Reference is made, for example, to US Patents 5,345,872 and 3,274,937. Such feedthroughs are widely used in electronics and electrical engineering. The material used for fusion, especially glass, serves as an insulator. Typical metal-fixed feedthroughs are constructed such that metallic inner conductors are fused into a pre-formed sintered glass part, which in turn is fused into an outer metal part with the so-called base body, formed from a ring- or plate-shaped element.Preferred applications for such metal-fixing material feedthroughs include, for example, ignition devices. These are used, among other things, for airbags or seatbelt tensioners in motor vehicles. In this case, the metal-fixing material feedthroughs are part of an ignition device. The complete ignition device comprises, in addition to the metal-fixing material feedthrough, an ignition bridge, the explosive, and a metal cover that tightly encloses the ignition mechanism. Either one, two, or more than two metallic pins can pass through the feedthrough. In a particularly preferred embodiment with one metallic pin, the housing is grounded; in a preferred two-pin embodiment, it is grounded to one of the pins.

[0003] Metal fixing material feedthroughs, particularly for airbag igniters or seatbelt tensioners, are known from US patents 2006 / 0222881 A1, 2004 / 0216631, EP-A-1 455 160, 2007 / 0187934 A1, and 2006 / A-1 813 906. These feedthroughs are characterized by the fact that the opening for the metal pins is punched out of the base body. According to US patent 2007 / 0187934 A1, the openings are punched through the entire thickness of the base body D using a strip material with a thickness in the range of 1 mm to 5 mm, preferably 1.5 mm to 3.5 mm, particularly between 1.8 mm and 3.0 mm, and most preferably between 2.0 mm and 2.6 mm.

[0004] The metal pin in the fixing material is inserted into the entrance opening punched into the base body over the entire thickness D of the base body, which lies in the area mentioned above.

[0005] Furthermore, the through-hole in the bushings with more than one pin is arranged off-center according to US 2007 / 0187934 A1.

[0006] Stamping from sheet metal according to US 2007 / 0187934 A1 has a number of disadvantages. One disadvantage is that stamping from a solid material, such as a sheet of the base body, results in a large amount of material waste.

[0007] In particular, with metal fixing material feedthroughs with two metal pins and an off-center through-hole, the problem arose that the off-center through-hole leads to a weakening of the glazing.

[0008] The object of the invention is therefore to avoid the disadvantages described above according to the prior art and in particular to provide a method for producing a base body in the form of a ring- or plate-shaped element for a metal fixing material feedthrough, which can be produced with less material waste than in the prior art, in particular also in a cold forming process.

[0009] According to the invention, the problem is solved by a method for producing a plate-shaped element that forms the base body, in particular for a metal fixing material feedthrough, in which a blank, in particular made of a wire-shaped material, is provided and the blank is subjected to processing in such a way that a through-opening can be introduced into a ring- or plate-shaped element formed from the blank by punching.

[0010] Preferably, the processing of the blank includes the creation of a relief area and forming, in particular cold forming. The processing steps of the method can be carried out in different sequences.

[0011] One possible sequence, without limitation, includes the following procedural steps: – A blank, in particular made of a wire-like material, will be provided. – The blank is cold-formed, particularly by upsetting, which changes the relative geometric dimensions, resulting in the plate-shaped element with an essentially round outer contour. A cutout area is incorporated into the plate-shaped element. After the cutout area is incorporated into the plate-shaped element, resulting in a thinner plate-shaped element in the area of ​​the through-hole being produced than the thickness of the plate-shaped element, particularly the base body, the through-hole is created by means of a punching process using this reduced thickness.

[0012] In a first embodiment of the method, the relief area can be introduced into the blank or the ring- or plate-shaped element, or the base body, by pressing the blank or the ring- or plate-shaped element against a punch. In the area of ​​the punch, the material flows around the blank or the ring- or plate-shaped element, which is preferably a steel with a copper content of 1 to 5 wt.% copper, due to the pressure. In this way, a relief bore or relief area can be introduced into the blank or the ring- or plate-shaped element by the punch. Alternatively, it is possible not to press the blank or the ring- or plate-shaped element against a punch, but rather to press a punch against one side of the blank or the ring- or plate-shaped element.This causes the material of the plate-shaped body to be forced out on the side opposite the side on which the pressure is applied. The result of this process is the creation of a cutout area or cutout hole.

[0013] After the cutout area has been created, a punching tool is inserted into the cutout area or the cutout bore, and the through-hole is created by punching. Preferably, the thickness of the ring- or plate-shaped element in the area of ​​the through-hole to be punched is reduced, preferably to values ​​of 1.5 mm to 4.5 mm.

[0014] It is particularly preferred if a conically tapered through-hole is punched out using the punching tool.

[0015] The advantage of the described method lies in the fact that the production of the ring- or plate-shaped element used in a metal-fixing material feedthrough occurs essentially within the same time interval for all the different process steps. This means that the cold forming step, the step of creating the clearance opening or area, and the step of punching the through-hole into the ring- or plate-shaped element all take essentially the same amount of time. In this way, it is possible to produce a ring- or plate-shaped element with a through-hole from a wire-like material with essentially the same cycle time at different workstations, i.e., the workstation for cold forming, the workstation for creating the clearance opening, and the workstation for punching.If it is necessary, as is the case, for example, in the prior art for a machined or cold-formed ring- or plate-shaped element, to introduce the hole not by a punching process but by means of a drilling process, the drilling step takes much longer than the cold forming, which means that the production of the ring- or plate-shaped element takes at least twice as long compared to the method according to the invention.

[0016] As previously stated, it is preferred that the plate-shaped element be made of steel, in particular stainless steel, with a copper content in the range of 1 wt.% to 5 wt.%, and especially between 2.0 wt.% and 4 wt.%. Such a material allows the ring- or plate-shaped element, or the base body, to be manufactured by cold forming, for example, from wire. In this process, a piece is first cut from a steel wire with the copper content specified above. In a further step, it is formed into the desired shape for the plate-shaped element by upsetting. This is only possible if the material has a certain degree of elasticity, which is achieved by the specified copper content. The cold forming process described results in a very high degree of compaction and work hardening of the material.

[0017] The material must not only be suitable for cold forming, but when used for applications such as airbag igniters, it must also possess sufficient stiffness to withstand mechanical extrusion forces of 1750 N to 3000 N acting on the fixing material within the igniter, without deformation. Furthermore, the material must also ensure reliable laser welding.

[0018] Surprisingly, it was found that a steel, in particular a stainless steel with a copper content of 1 wt.% to 5 wt.%, combines these two opposing properties: on the one hand, sufficient elasticity for a cold forming process, and on the other hand, sufficient strength or flexural stiffness to withstand the high pull-out forces or high compressive force under load, such as can occur in a metal-fixing material feedthrough in a detonator.

[0019] The force required to expel the fixative material from the opening of the metal-fixative material feedthrough, as described above, is the force necessary to force it out. The magnitude of this force can be determined either hydrostatically or mechanically. If the force is determined mechanically, a plunger is used to press down on the area of ​​the fixative material, with the area of ​​the plunger pressing on the material being smaller than the area of ​​the material itself.

[0020] Alternatively, the expressive force can be measured hydrostatically. In a hydrostatic measurement, the fixing material is subjected to hydrostatic pressure, for example water pressure, and the hydrostatic pressure at which the fixing material is expelled from the through-hole is measured.

[0021] In addition to the inventive method for producing the ring- or plate-shaped element, the invention also provides a method for producing a metal-fixing material feedthrough with such a ring- or plate-shaped element as a base body, wherein the metal pin of the metal-fixing material feedthrough is glazed into the through-opening of the ring- or plate-shaped element using a fixing material.

[0022] First, the ring- or plate-shaped element is produced using the method according to the invention. Then, a metal pin is melted into a fixing material, which can be, for example, a glass plug. Next, the glass plug, together with the metal pin, is inserted into the through-hole, and the glass and metal ring (here, the ring- or plate-shaped element) are heated so that, after cooling, the metal shrinks onto the fixing material (here, the glass plug).

[0023] A preferred method for manufacturing a metal-fixing material feedthrough is described, in which two metal pins are provided. Since the through-opening in the plate-shaped element according to the invention is arranged essentially in the middle, the two metal pins are bent. While one of the metal pins is passed through the through-opening in the glass plug in an insulating manner, the other metal pin is preferably designed as a grounding pin and conductively connected to the base body, for example by brazing.

[0024] The metal fixing material feedthrough manufactured according to the invention is preferably used in ignition devices of any design. For example, such an ignition device can be provided for a pyrotechnic protective device, in particular for an airbag or seatbelt pretensioner. Such a pyrotechnic protective device comprises a metal fixing material feedthrough manufactured according to the invention and a cap connected to the base body of this metal fixing material feedthrough, wherein a propellant charge is enclosed between the metal fixing material feedthrough and the cap. The ignition device with the metal fixing material feedthrough designed according to the invention can be used in gas generators, for example hot gas generators, cold gas generators, and hybrid generators.

[0025] Preferred areas of application are, as mentioned above, equipment for pyrotechnic protective systems, for example airbags and seatbelt tensioners.

[0026] The solution according to the invention is explained below with reference to figures, without being limited thereto. The following details are shown therein:

[0027] Fig. 1a– Fig. 1c a method for producing a ring- or plate-shaped element according to the invention;

[0028] Fig. 2a– Fig. 2c a ring- or plate-shaped element according to the invention;

[0029] Fig. 3a– Fig. 3c a metal fixing material feedthrough according to the invention;

[0030] Fig. 4a– Fig. 4b Comparison of the phase lines in a metallurgical section of a ring- or plate-shaped body according to the prior art and according to the invention.

[0031] In Fig. Figure 1a shows the various stages of the manufacturing process. In the first stage, a wire-shaped material is used. 1000 a blank 1010separated or cut off. In the second step, that is, at the second station to which the cut-off blank is transported in a manufacturing process, the blank is 1010 The blank is cold-formed by upsetting until its external dimensions match those of the ring- or plate-shaped element to be processed. This alters the relative geometric dimensions; in this case, the blank becomes wider due to the upsetting process. In the subsequent third stage, the cold-formed plate-shaped element is further processed. 1020 with pressure 1030 against a stamp 1040Pressed. Due to the pressure with which the ring- or plate-shaped element is pressed against the punch, the material of the ring- or plate-shaped element encloses the punch. This removes the material from the plate-shaped element in the area of ​​the punch, leaving the plate-shaped element with a release opening or release area, as shown in the fourth station. 1050 The description of the sequence of the aforementioned process steps is only an example. It would also be possible to first create the release opening in a blank and then perform the forming process.

[0032] The release bore allows for [something] in the area 1060The thickness D of the ring- or plate-shaped element has been significantly reduced, namely to a thickness DR. The thickness of the ring- or plate-shaped element is reduced by between 20% and 60%, particularly between 30% and 50%. Now, in a fifth process step, a stamping tool is used. 1060 inserted into the release opening and a conical through-hole created by a punching step 1070the material is driven through the ring- or plate-shaped element with the reduced thickness. Essentially, the resulting ring- or plate-shaped element with a clearance opening and a through-hole is then formed, as shown in the fifth station. The inventive method is characterized in that the cycle time for each of the specified stations—that is, cutting from the wire-shaped base material, forming, creating the clearance opening or the clearance area, and punching out the through-hole from the plate-shaped element with reduced thickness—is essentially the same. This makes it possible to automate the inventive method to a very high degree.

[0033] In the Fig. 1b and Fig. Figure 1c shows the two fundamentally possible methods for creating the clearance area or the clearance bore. Fig. 1b will be as in Fig. 1a in the third step the ring- or plate-shaped element 1020 against a stamp 1040 pressed so that the material flows around the die, resulting in a release opening. Alternatively, it would be possible, as in Fig. 1c showed that not the plate-shaped base body 1020 against a stamp 1040 is pressed, but the opposite is true. The stamp is pressed. 1040 against the ring- or plate-shaped base body 1020 Then, due to the pressure on the side of the ring- or plate-shaped body opposite the punch, the material is transported out. The result is a re-formed ring- or plate-shaped element with a relief area or relief bore.

[0034] In the Fig. 2a– Fig. 2c is a ring- or plate-shaped structure or element, produced according to the inventive method, shown, which is essentially used as a base body for a metal-fixing material feedthrough. The ring- or plate-shaped element 1 has, like Fig. Figure 2b, in the top view, essentially shows a circular outer contour. 3 The plate-shaped body 1 is preferably carried out by a cold forming process, as in Fig. 1a shows, for example, how it is made from a wire. First, a piece of wire is cut off, and then this piece of wire is cold-formed, in particular by upsetting, into a circular shape. Fig. 2b in the top view from the back 14 presented. Fig. Figure 2c shows a perspective view from the back. 14 .

[0035] Following this, the cold-formed part is formed 1for example by a stamp, a clearance area 5 , which is also known as a clearance borehole.

[0036] The height or thickness of the clearance hole, which, as shown in the top view in Fig. 2b shows that it is also essentially circular, and its HF is...

[0037] The thickness of the entire ring- or plate-shaped element obtained by cold forming is D. The material is thus weakened in the areas where the through-hole is introduced essentially centrally to the axis of rotation R of the plate-shaped body, so that the solid material through which the through-hole passes 10 in the ring- or plate-shaped element 1 The thickness D of the plate-shaped element is preferably between 3.5 mm and 6 mm, and the thickness DR of the area to be punched out is between 1.5 mm and 3 mm. The plate-shaped element1 When used in a metal fixing material feedthrough, the material is inserted into the through-opening. 10 A metal pin is inserted into a fixing material, for example, a glass plug. The glass plug then rests against the walls of the opening. This prevents the pin, which is encased in a glass plug, from being forced out of the opening even under high pressure. 10 To avoid this, means are provided to prevent relative movement from the front. 12 of the ring- or plate-shaped element 1 to the back 14 to prevent this. In the present embodiment, this is achieved by ensuring that the through-opening is at least partially obstructed. 20 It tapers to a point.

[0038] In the Fig. 3a to Fig. 3c is the use of a plate-shaped element according to the Fig. 2a– Fig. 2c according to the invention is shown in a metal fixing material feedthrough, in particular for airbag igniters and seatbelt tensioners. This shows Fig. 3a a cut according to Fig. 2a, Fig. 3b a top view according to Fig. 2b and Fig. 3c a perspective view according to Fig. 2c.

[0039] Same components as in Fig. 2a to Fig. 2c are marked with the same reference numbers.

[0040] The ring- or plate-shaped element is clearly visible. 1 with a thickness D. Furthermore, a clearance hole can be seen. 5 , which, for example, are formed from the cold-formed, plate-shaped element using a stamp 1 is pushed out. Above the punch is the through-hole punched out of the remaining material with thickness DR. 10 with a conical shape 20 to recognize.

[0041] The ring- or plate-shaped element serves as a base for a metal fixing material feedthrough with a total of two metal pins. 50 , 52 . While the metal pin 50 in a fixing material 60 , here a glass material, which can also be a glass-ceramic material or a ceramic material, isolated from the ring- or plate-shaped base body 1 The second metal pin is used when it is passed from the front to the back. 52 as a grounding pin. For this purpose, the second metal pin is used. 52 directly with the ring- or plate-shaped body 1 connected. Both the metal pin 50 like the metal pin 52 are curved. The arc of both metal pins is made with 54 or 56 clearly marked and easily recognizable.

[0042] The metal pin 50 is also equipped with resources 62 on the metal pin 50self-provided, which engage in the glass stopper and thus prevent the metal pin from being pushed out of the glass stopper 60 , in which the metal pin is encased in glass, even at high pressures.

[0043] Glazing the metal pin 50 into the fixing material 10 This is done by melting. Once the metal pin is melted into the fixing material, the glass plug, along with the metal pin, is inserted into the opening. 10 The glass plug is inserted. Subsequently, the glass plug, together with the ring- or plate-shaped element (i.e., the base body), is heated so that, after cooling, the metal of the ring- or plate-shaped element shrinks onto the fixing material (in this case, the glass material), just as it did previously during the production of the glass plug, when the metal pin is inserted into the glass plug. The metal pin serves as the ground. 52It is conductively connected to the ring- or plate-shaped element, for example by brazing. The solder joint is equipped with 70 designated.

[0044] Fig. Figure 3b shows a top view of a metal fixing material feedthrough according to the invention. The central feedthrough is clearly visible in the top view. 10 in the ring- or plate-shaped element 1 Furthermore, the bent metal pin is clearly visible. 50 or 52 Especially with metal pins 50 It is clearly visible that the metal pin at its end 72 offset from the center R of the plate-shaped base body, i.e., bent. This also applies to the metal pin. 52 The curved pins are also well viewed in Fig. 3c to recognize. The view in Fig. Figure 3c of the entire metal fixing material feedthrough also shows the soldering area in particular. 70of the ground pin as well as the clearance hole or clearance area 5 in the ring- or plate-shaped base body. A characteristic feature of a metal-fixing material feedthrough with a plate-shaped element as the base body according to the invention, having a clearance bore or clearance area, is that the glazing 20 the metal pin is inserted into the base body only via a partial area, namely only via the thickness DR of the through-hole and not via the total thickness D of the base body.

[0045] In Fig. 4a is a metallurgical section through a ring- or plate-shaped element produced by the forming and stamping process according to the invention. 1 , as in Fig. 2a shown.

[0046] Same components as in Fig. 2a are designated with the same reference numbers.

[0047] As seen from the metallurgical cut according to Fig. As can be seen from 4a, the ring- or plate-shaped elements produced according to the inventive method are 1 through structure / flow lines 1500 characterized, which are located in the area 1600 have been bent by the forming process.

[0048] In contrast, this shows Fig. 4b a component manufactured using conventional machining methods 100 , which is in particular a turned part. The structure / flow lines are also shown. 2000 The structure / flow lines 2000 are essentially parallel and point in the same direction as the bar stock from which the ring- or plate-shaped component is made. 100 according to the state of the art, as in Fig. 4b shown, was produced. The through-opening 110 is from the component 100 drilled out.

[0049] The invention provides for the first time a method for the simple production of a plate-shaped element, characterized by compatibility with the metal fixing material feedthroughs according to the prior art, thereby enabling its installation in conventional igniters or airbags. QUOTES INCLUDED IN THE DESCRIPTION

[0050] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0051] US 5345872 A

[0002] US 3274937 A

[0002] US 2006 / 0222881 A1

[0003] US 2004 / 0216631

[0003] EP 1455160 A

[0003] US 2007 / 0187934 A1 [0003, 0003, 0005, 0006] US 1813906 A

[0003]

Claims

[1] Method for manufacturing a ring- or plate-shaped element, in particular for a metal fixing material feedthrough, especially for devices exposed to high pressures, preferably airbag igniters or seatbelt tensioners, with a through-opening, wherein a blank ( 1000 ), in particular made of a wire-shaped material, is provided and the blank ( 1000 ) is processed in such a way that the blank is transformed into a ( 1000 ) reshaped ring- or plate-shaped element ( 1010 ) the passage opening ( 1070 ) can be introduced by punching. [2] Method according to claim 1, characterized in that the processing of the blank ( 1000 ) the introduction of an exemption area ( 1050 ) includes. [3] Method according to one of claims 1 to 2, characterized in that the processing of the blank ( 1000) includes cold forming, in particular upsetting. [4] Method according to one of claims 1 to 3, characterized in that the ring- or plate-shaped element has a substantially round or circular outer shape and the through-opening is arranged centrally. [5] Method according to one of claims 1 to 4, characterized in that for the introduction of the release hole ( 1050 ) the blank ( 1000 ) or the ring- or plate-shaped element ( 1010 ) against a stamp ( 1040 ) is pressed and material of the blank ( 1000 ) or ring- or plate-shaped element ( 1010 ) the stamp is surrounded by water. [6] Method according to any one of claims 1 to 5, characterized in that a punch is used to create the release hole ( 1040 ) against one side of the blank ( 1000 ) or ring- or plate-shaped element ( 1010) is pressed and the material of the blank ( 1000 ) or ring- or plate-shaped element on the opposite side of the plate-shaped element. [7] Method according to any one of claims 2 to 6, characterized in that after the introduction of the release area ( 1050 ) into the clearance area a punching tool ( 1060 ) is inserted to create the passage opening ( 1070 ) to punch out. [8] Method according to claim 7, characterized in that the stamping tool is used ( 1060 ) a substantially conical through-hole is punched out. [9] Method according to any one of claims 3 to 8, characterized in that the cold forming of the plate-shaped element ( 1010 ) from the blank ( 1000 ), the introduction of the exemption area ( 1050 ) as well as punching the through-hole ( 1070) into the plate-shaped element essentially occurs within the same time period. [10] Method for producing a metal fixative feedthrough, comprising the following steps: – Manufacturing a plate-shaped body according to any one of claims 1 to 9; – Preparation of a fixative material ( 60 ), comprising at least one in the fixing material ( 60 ) embedded metal pin; – Insertion of the fixative material ( 60 ) with metal pin ( 50 ) into the passage opening ( 10 , 1070 ) of the plate-shaped element ( 1 , 1010 ); – Softening of plate-shaped element ( 1 , 1010 ) and fixative material ( 60 ) and subsequent cooling, so that a force-fit connection is formed between the fixing material and the material of the plate-shaped element.

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