Method for producing a ring-shaped or plate-like element

Abstract

The invention relates to a method for producing a ring-shaped or plate-like element, in particular for a metal-sealing material-feedthrough, in particular for devices which are subjected to high pressures, for example igniters for airbags or belt tensioning devices, whereby a blank, especially in the embodiment of a wire-shaped material is provided and the blank is subjected to processing so that a feedthrough-opening can be incorporated into a ring-shaped or plate-like element created from the blank.

Claims

1. A method for producing a ring-shaped or plate-like element for a metal-sealing material-feedthrough for a plurality of devices which are subjected to high pressures, said method comprising the steps of: providing a blank; and subjecting said blank to a processing so that a feedthrough opening with a diameter DFT can be incorporated into said element created from said blank, wherein said processing of said blank includes incorporation of a relief region with a diameter DRE, said diameter DRE being greater than the diameter DFT of the feedthrough opening, wherein said blank is formed from a wire-shaped material and said processing of said blank includes a cold-forming process.

2. The method according to claim 1, wherein the diameter of the relief region DRE is 1.1 to 5 times greater than the diameter of the feedthrough opening DFT.

3. The method according to claim 1, wherein the diameter of the relief region DRE is 1.1 to 2 times greater than the diameter of the feedthrough opening DFT.

4. The method according to claim 1, wherein the relief region is located in the center of the element and the diameter of the relief region DRE is calculated by DRE=DOV2DW, wherein DOV is the overall diameter of the element and DW is the length or thickness of the wall surrounding the relief region.

5. The method according to claim 1, wherein the feedthrough opening is punched through said element and the thickness DR of the feedthrough opening is at maximum 1.5 times greater than the diameter DFT of the feedthrough opening.

6. The method according to claim 1, wherein said plurality of devices includes at least one of an igniter for an airbag and a belt tensioning device.

7. The method according to claim 1, wherein said cold-forming process includes compression.

8. The method according to claim 1, wherein said element has an essentially round outside contour and said feedthrough opening is located in a center.

9. The method according to claim 1, wherein, after producing said relief region, a punching tool having a diameter corresponding to the diameter of the feedthrough opening DFT which is smaller than the diameter of the relief region DRE is provided in an area associated with said relief region in order to punch out said feedthrough opening.

10. The method according to claim 9, wherein said punching tool is a stance needle.

11. The method according to claim 9, wherein cold forming said element from said blank occurs in a first amount of time, providing said relief region occurs in a second amount of time, and punching said feedthrough opening into said element occurs in a third amount of time, wherein the first amount of time, the second amount of time, and the third amount of time are essentially the same.

12. The method according to claim 1, wherein the produced element includes bent flow lines adjacent to the relief region.

13. A method for producing a ring-shaped or plate-like element for a metal sealing material-feedthrough for a plurality of devices which are subjected to high pressures, the method comprising the steps of: providing a wire-shaped material as a blank; cold-forming the blank, whereby relatively geometric dimensions of the blank are changed, resulting in the ring-shaped or plate-like element; and subjecting said element to a processing so that a feedthrough opening with a diameter DFT is incorporated into said element created from said blank, wherein said processing of said element includes incorporation of a relief region with a diameter DRE, said diameter DRE being greater than the diameter DFT of the feedthrough opening.

14. The method according to claim 13, wherein, to incorporate the relief region, said blank or said element is pressed against a punch and a material of said blank or said element flows around said punch.

15. The method according to claim 14, wherein, after producing said relief region, a punching tool having a diameter corresponding to the diameter of the feedthrough opening DFT which is smaller than the diameter of the relief region DRE is provided in an area associated with said relief region in order to punch out said feedthrough opening.

16. The method according to claim 15, wherein said punching tool is a stance needle.

17. The method according to claim 15, wherein cold forming said element from said blank occurs in a first amount of time, providing said relief region occurs in a second amount of time, and punching said feedthrough opening into said element occurs in a third amount of time, wherein the first amount of time, the second amount of time, and the third amount of time are essentially the same.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein:

(2) FIGS. 1a-1c show a method for the production of a ring-shaped or plate-like element according to the invention;

(3) FIGS. 2a-2c show a ring-shaped or plate-like element according to the invention;

(4) FIGS. 3a-3c show a metal-sealing material-feedthrough according to the invention; and

(5) FIGS. 4a-4b show a comparison of the phase lines in a metallurgical section of a ring-shaped or a plate-like body according to the current state of the art.

(6) Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate embodiments of the invention, and such exemplifications are not to be construed as limiting the scope of the invention in any manner.

DETAILED DESCRIPTION OF THE INVENTION

(7) FIG. 1a illustrates the various stations of the production process. In the first station a blank 1010 is separated or respectively cut from a wire like material 1000. In the second step, that is in the second station to which the severed blank is transported in one production step, the blank is cold-formed by compressing to the point where the outside dimensions conform to the outside dimensions which the ring-shaped or plate-like element that is to be manufactured must have. The relative geometric dimensions are hereby altered, whereby the blank predominantly becomes wider due to compressing. In the following third station the cold-formed plate-like element 1020 is pressed against a punch 1040 with pressure 1030. Due to the pressure with which the ring-shaped or plate-like element is pressed against the punch, the material of the ring-shaped r plate-like element surrounds the punch. The material in the region of the punch is thereby removed from the plate-like element and the plate-like element with a relief opening or respectively relief region 1050 shown in the fourth station remains. The description of the sequence of process steps is merely exemplary. A relief opening in the blank could also be produced first, followed by subsequent reshaping.

(8) Due to the relief bore thickness D of the plate-like element has been greatly reduced in region 1060 of the ring-shaped or plate-like elementthat is to a thickness DR. The thickness of the ring-shaped or plate-like element is hereby reduced by between 20% and 60%, especially between 30% and 50%. Then, in a fifth process step a punching tool 1060 is inserted into the relief opening and a conical feedthrough opening 1070 is punched through the ring-shaped or plate-like element. Essentially, the ring-shaped or plate-like element with relief opening and feedthrough opening results as demonstrated in the fifth station. The inventive method distinguishes itself in that for each of the cited stations, that is for severing from the wire-like base material, forming, provision of the relief opening or respectively the relief region and punching of the feedthrough opening through the plate-like element with reduced thickness, essentially the same time is taken for each process step. This allows for the inventive method to be highly automated.

(9) FIGS. 1b and 1c illustrate two methods which are possible in principle for providing the relief region or respectively the relief bore. In FIG. 1b, as in FIG. 1a the ring-shaped or plate-like element 1020 is pressed against a punch 1040 in the third step, so that the material surrounds the punch and from this a relief opening results. Alternatively it is possible, as shown in FIG. 1c, that not the plate-like base body 1020 is pressed against a punch 1040, but vice versa, punch 1040 is pressed against the ring-shaped or plate-like base body 1020. Then, due to the pressure on the side of the ring-shaped or plate-like body opposite the punch, the material is expelled. The result again is the ring-shaped or plate-like element with relief region or respectively relief bore.

(10) FIGS. 2a-2c illustrate a ring-shaped or plate-like formation or element, produced according to the inventive method which essentially is utilized as the base body for a metal-sealing material-feedthrough. As shown in a top view in FIG. 2b, the ring-shaped or plate-like element 1 has essentially a circular outer contour 3. Plate-like body 1 is produced preferably by a cold-forming process, as shown in FIG. 1a, for example from a wire. Hereby, a piece is first cut from the wire and is subsequently transformed through cold-forming, in particular through compression into the circular form illustrated in FIG. 2b in a top view from backside 14. FIG. 2c is an exploded view from backside 14.

(11) Following this, a relief region 5 which is also referred to as relief bore is provided into the cold-formed component 1 by means of a punch.

(12) The height or respectively thickness of the relief bore, which essentially circular as shown in the top view in FIG. 2b, equals HF. The relief bore or relief region represents a recess from one side of the ring-shaped or plate-like element. This recess is surrounded by a wall having a local thickness or length DW of its top area. As described, the relief region can be located in the center of the ring-shaped or plate-like element. In this case DW has substantially the same value within said ring-shaped or plate-like element.

(13) The thickness of the entire ring-shaped or plate-like element which is obtained through cold-forming, equals D. The material therefore is weakened in the areas where the feedthrough opening is essentially placed central relative to the rotational axis R of the plate-like body, so that the solid material through which feedthrough opening 10 in the ring-shaped or plate-like element 1 must be punched equals merely DR. Thickness D of the plate-like element varies for example between 3.5 mm to 6 mm and thickness DR of the region to be punched out between 1.5 mm and 3 mm. As can be seen from FIG. 2a the diameter of the relief region is denoted with DRE. The relief region has a circular contour. The diameter of the circular feedthrough opening is denoted with DFT. The overall diameter of the ring-shaped or plate-like element is denoted with DOV. The length or thickness of area outside the relief region is denoted with DW. As described above, this area can be used to connect other functional components such as metal pins to the ring-shaped or plate-like element. According to the invention, the aforementioned design rules are fulfilled. The diameter of the relief region DRE is determined as difference between DOV and the required value for DW. As described, DW is for example a least 1.5 times the diameter of a metal pin to be connected to the ring-shaped or plate-like element in this area. This leads to the advantageous values for DRE to be between 1.1 to 5 times, for example 1.1 times to 2 times greater than the diameter DFT of the feedthrough opening. This also means the following relations are fulfilled:
DR1.5DFT and
DRE>DFT

(14) If for example the diameter DFT of the feedthrough opening is 2 mm and the overall diameter DOV is 7 mm, then the diameter of the relief region is for example 4 mm, which is 2 times more than the diameter of the feedthrough opening. If the plate-like element 1 is utilized in a metal-sealing material-feedthrough, then a metal pin in a sealing material, for example in a glass plug is inserted in the feedthrough opening. The glass plug is then in contact with the walls of the feedthrough opening. In order to avoid pushing the metal pin which was encased in a glass plug out of feedthrough opening 10, even at high pressures means are provided to prevent a relative movement from the front side 12 of ring-shaped or plate-like element 1 to the rear side 14. In the present design example this is achieved in that the feedthrough opening tapers conically over at least one region 20.

(15) FIGS. 3a through 3c illustrate utilization of a plate-like element according to FIGS. 2a-2c according to the invention in a metal-sealing material-feedthrough, especially for airbag ignition devices, belt tensioning devices. Hereby FIG. 3a illustrates a section according to FIG. 2a, FIG. 3b a top view according to FIG. 2b and FIG. 3c an exploded view according to FIG. 2c.

(16) Identical components as shown in FIGS. 2a through 2c carry the same identification numbers.

(17) Ring-shaped or plate-like element 1 with a thickness D is clearly recognizable. Moreover, relief bore 5 with the diameter DRE is recognizable, which is punched out of the cold-formed plate-like element 1 by means of a punch. Above the punch, feedthrough opening 10 with the diameter DFT and its conical progression 20 which is punched from the remaining material with thickness DR can be seen. The diameter DRE of the relief region is always greater than the diameter DFT of the feedthrough opening, for example 1.1 to 5 times greater than the diameter DFT of the feedthrough opening.

(18) The ring-shaped or plate-like element serves as the basis for a metal-sealing material-feedthrough with a total of two metal pins 50, 52. The diameter of pin 52 is denoted with DGP. The diameters of both pins 50 and 51 can be the same. While metal pin 50 is fed through the ring-shaped or plate-like base body 1 from the front side to the rear side, insulated in a sealing material 60in this case a glass material which however can also be glass ceramics or ceramic materialssecond metal pin 52 serves as ground pin. For this purpose, second metal pin 52 is connected directly with ring-shaped or plate-like body 1. Usually a solder or welding connection are used. Metal pin 50 as well as metal pin 52 is curved. The curvature of both metal pins is identified with 54 and 56 respectively and is clearly recognizable.

(19) Metal pin 50 is moreover provided with means 62 on metal pin 50 itself, which engage into the glass plug thereby preventing the metal pin being pushed out of glass plug 60 into which the metal pin is glazed, even at high pressures.

(20) Glazing of metal pin 50 into sealing material 10 occurs through sealing in. As soon as the metal pin is fused into the sealing material the glass plug is inserted into the feedthrough opening 10 together with the metal pin. Then, the glass plug, together with the ring-shaped or plate-like element, that is the base body, is heated so that after cooling the metal of the ring-shaped or plate-like element shrinks onto the sealing material, in this case the glass material, as previously in the production of the glass plug whereby the metal pin is inserted into the glass plug. The grounded metal pin 52 is connected conductively with the ring-shaped or plate-like element, for example through brazing. The welding location is identified with 70. Examples of values for a said ring-shaped and plate-like element according to the invention are an overall diameter DOV of 7 mm and an entire thickness D of 4.4 mm. The metal pins have a diameter DGP of 1 mm. DW can be calculated to be at least 1.5 mm by applying the aforesaid design rules. The diameter DFT of the feedthrough opening could be 2 mm in order to secure a reliable glazing. The feedthrough opening is stamped through the base body, therefore applying the aforesaid design rules requires that the length or thickness DR of the feedthrough opening is at maximum DR=1.5DFT=3 mm. Those numbers are used to determine the diameter DRE of the relief region to be DRE=7 mm21.5 mm=4 mm. Thereby the diameter DRE of the relief region is greater than the diameter DFT of the feedthrough opening. In this case 2 times greater. The height HF of the relief region is HF=DDR=4.4 mm3 mm=1.4 mm. Of course those are example values. The person skilled in the art is able to apply the described design rules in order to apply those to other dimensions, which are also covered by the inventions.

(21) FIG. 3b is a top view of an inventive metal-sealing material-feedthrough. Clearly seen in the top view is the central feedthrough 10 in the ring-shaped or plate-like element 1. Moreover, curved metal pin 50 and 52 respectively is clearly recognizable. Especially on metal pin 50 it can be clearly seen that the metal pin is offset, that is bent at its end 72 relative to center R of the plate-like base body. This also applies to metal pin 52. The curved pins are also clearly visible in the view in FIG. 3c. The illustration in FIG. 3c of the entire metal-sealing material-feedthrough shows in particular also the welding region 70 of the grounded pin as well as the relief bore or respectively the relief region 5 in the ring-shaped or plate-like base body. The diameter in the relief region is denoted with DRE, the diameter of the feedthrough opening with DFT. It is characteristic for a metal-sealing material-feedthrough with a plate-like element as base body according to the invention which has a relief bore or respectively a relief region that the embedding in glass 20 of the metal pin in the base body occurs only over a partial region, namely only over the thickness DR of the feedthrough opening and not over the entire thickness D of the base body.

(22) FIG. 4a is a metallurgical section through a ring-shaped or plate-like element 1 produced through the inventive forming and punching process, as illustrated in FIG. 2a.

(23) Identical components as shown in FIG. 2a carry the same identification numbers.

(24) As can be seen from the metallurgic section according to FIG. 4a, the ring-shaped or plate-like elements 1 produced according to the inventive method are identified through structure-/flow-lines 1500 which were bent in region 1600 due to the forming process.

(25) In contrast to this, FIG. 4b illustrates a component 100 produced in accordance with the conventional method by means of machining, which is in particular a turned part. Shown again are the structure-/flow lines 2000. Structure-/flow lines 2000 are essentially parallel and point into the same direction as the bar stock from which the ring-shaped or respectively plate-like component 100 was produced according to the state of the art, as shown in FIG. 4b. Feedthrough opening 110 is bored out of component 100.

(26) The invention cites a method for the first time with which a plate-like element is to be produced in a simple manner and distinguishes itself through compatibility with the metal-sealing material-feedthrough according to the state of the art, thus enabling installation in conventional ignition devices or respectively airbags.

(27) While this invention has been described with respect to at least one embodiment, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.