Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01T—SPARK GAPS; OVERVOLTAGE ARRESTERS USING SPARK GAPS; SPARKING PLUGS; CORONA DEVICES; GENERATING IONS TO BE INTRODUCED INTO NON-ENCLOSED GASES
  • H01T13/00—Sparking plugs
  • H01T13/20—Sparking plugs characterised by features of the electrodes or insulation
  • H01T13/39—Selection of materials for electrodes
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01T—SPARK GAPS; OVERVOLTAGE ARRESTERS USING SPARK GAPS; SPARKING PLUGS; CORONA DEVICES; GENERATING IONS TO BE INTRODUCED INTO NON-ENCLOSED GASES
  • H01T13/00—Sparking plugs
  • H01T13/20—Sparking plugs characterised by features of the electrodes or insulation
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01T—SPARK GAPS; OVERVOLTAGE ARRESTERS USING SPARK GAPS; SPARKING PLUGS; CORONA DEVICES; GENERATING IONS TO BE INTRODUCED INTO NON-ENCLOSED GASES
  • H01T13/00—Sparking plugs
  • H01T13/20—Sparking plugs characterised by features of the electrodes or insulation
  • H01T13/32—Sparking plugs characterised by features of the electrodes or insulation characterised by features of the earthed electrode
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01T—SPARK GAPS; OVERVOLTAGE ARRESTERS USING SPARK GAPS; SPARKING PLUGS; CORONA DEVICES; GENERATING IONS TO BE INTRODUCED INTO NON-ENCLOSED GASES
  • H01T13/00—Sparking plugs
  • H01T13/54—Sparking plugs having electrodes arranged in a partly-enclosed ignition chamber
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
  • Y02T10/00—Road transport of goods or passengers
  • Y02T10/10—Internal combustion engine [ICE] based vehicles
  • Y02T10/12—Improving ICE efficiencies

Definitions

• the present invention relates to a pre-chamber spark plug, in particular for automotive applications, with two noble metal bodies which face one another opposite one another.
• Pre-chamber spark plugs for gas internal combustion engines are commonly used in large stationary systems. With these spark plugs, the service life of the prechamber spark plug is a crucial economic and technical parameter. However, spark plugs for mobile internal combustion engines must in particular be as cost-effective as possible and in particular also be suitable for mass production. In order to meet the required service life, precious metal wearing surfaces are usually used on the center electrode, which, however, make prechamber spark plugs of this type considerably more expensive.
• the prechamber spark plug according to the invention with the features of claim 1 has the advantage that simple and inexpensive mass production is possible.
• the prechamber spark plug according to the invention is suitable not only for use in stationary internal combustion engines but also for automotive applications, which include mobile internal combustion engines.
• the prechamber spark plug according to the invention has two precious metal bodies, namely a first precious metal body on the center electrode and a second precious metal body on the ground electrode.
• the ground electrode is fixed in a case, and an insulator electrically insulates the center electrode from the ground electrode.
• a cap is provided which, together with a part of the housing, defines a prechamber of the prechamber spark plug.
• the two precious metal bodies each have end spark surfaces which are parallel to each other and face each other in the pre-chamber at a predetermined distance to produce an ignition spark therebetween in use.
• the first precious metal body is particularly preferably arranged laterally on the center electrode. As a result, the first precious metal body can be easily fixed to the center electrode.
• the first front spark surface is parallel to the central axis of the prechamber spark plug.
• the second precious metal body is preferably arranged at a right angle to a central axis of the prechamber spark plug. As a result, the second spark surface of the second precious metal body is arranged perpendicular to the central axis of the prechamber spark plug.
• the first precious metal body is arranged in a lateral blind hole in the center electrode.
• the first noble metal body is arranged on a flattened area of the center electrode that is directed toward the ground electrode.
• the center electrode preferably has a lateral flattening, to which the holding element is fastened.
• the first noble metal body is then arranged laterally on the holding element.
• the flattening is preferably arranged at the free end of the center electrode.
• the second noble metal body is arranged on a flattening on the ground electrode and the first noble metal body is arranged on an end face of the center electrode.
• the flattening is preferably arranged at the free end of the ground electrode.
• the noble metal bodies are preferably connected to the respective electrodes by means of soldering or welding or by means of a press connection.
• the center electrode has a bevel on its end face, on which the first precious metal body is arranged.
• the ground electrode, on the front side of which second noble metal body is arranged, is then preferably arranged at an angle to the central axis of the prechamber spark plug, so that the spark surfaces of the two noble metal bodies of the center electrode and the ground electrode face each other.
• the angle is preferably selected in a range from 30° to 60° and is particularly preferably 45°.
• the first precious metal body is preferably arranged on a holding element which is fixed on the center electrode. More preferably, the holding element is fixed laterally to the center electrode.
• the holding element is preferably made of a material containing nickel.
• the holding element is arranged on an end face of the center electrode and the first precious metal body is then fixed laterally to the holding element.
• the holding element is a ring with a central opening, at which the holding element is fixed to the center electrode.
• the first noble metal body is arranged on the side of the ring.
• the ring particularly preferably has a lateral flattening, to which the first precious metal body is attached. More preferably, the center electrode has a shoulder on which the ring-shaped holding element is arranged. As a result, a predefined, secure fixation of the holding element is possible. As a further alternative or in addition, the ring-shaped holding element has a shoulder at the opening, with which a secure placement for fixing the holding element to the center electrode is possible.
• the holding element is arcuate, in particular with a 90° arc, with the first precious metal body being arranged on the end face of the arc.
• the arcuate holding element preferably tapers in the direction of the free end, for example stepwise or continuously. This allows easy bending.
• the first and second noble metal body are identical, in particular as a cylindrical pin (pin).
• the precious metal body itself is arcuate and is fixed to an end face of the center electrode, which is perpendicular to the center axis of the prechamber spark plug.
• the first noble metal body is preferably a 90° arc.
• the first precious metal body is preferably made from a wire with a diameter in the range from 0.5 mm to 2 mm.
• the first sparking face of the center electrode and the second sparking face of the ground electrode are disposed obliquely to the central axis X-X of the prechamber spark plug.
• the spark surfaces are arranged as slopes to the central axis.
• the ground electrode is preferably arranged perpendicularly to the central axis X-X.
• an axial length of the prechamber spark plug can be reduced by this configuration.
• the bevel is particularly preferably formed on the first noble metal body of the center electrode and a second bevel is formed on the second noble metal body of the ground electrode.
• the first and second noble metal bodies of the center electrode and the ground electrode are cylindrical, and the slopes are arranged on the center electrode and the ground electrode, respectively.
• the present invention relates to an internal combustion engine with a prechamber spark plug according to the invention, in particular for automotive applications.
• FIG. 1 shows a schematic sectional view of a prechamber spark plug according to a first preferred exemplary embodiment of the invention
• FIG. 2 shows a schematic sectional view of a prechamber spark plug according to a second preferred exemplary embodiment of the invention
• Figure 3 is a schematic, perspective partial sectional view of
• FIG. 4 shows a schematic sectional view of a prechamber spark plug according to a third preferred exemplary embodiment of the invention
• Figure 5 is a schematic perspective partial sectional view of
• FIG. 6 shows a schematic sectional view of a prechamber spark plug according to a fourth preferred exemplary embodiment of the invention
• FIG. 7 shows a schematic sectional view of a prechamber spark plug according to a fifth preferred exemplary embodiment of the invention.
• Figure 8 is a schematic, perspective sectional view of a
• Prechamber spark plug according to a sixth preferred embodiment of the invention.
• FIG. 9 shows a schematic sectional view of the prechamber spark plug from FIG.
• FIG. 10 shows a schematic sectional view of a prechamber spark plug according to a seventh preferred exemplary embodiment of the invention
• Figure 11 is a plan view of the center electrode of Figure 10
• FIG. 12 shows a schematic sectional view of a prechamber spark plug according to an eighth preferred exemplary embodiment of the invention
• FIG. 13 shows a schematic sectional view of a prechamber spark plug according to a ninth preferred exemplary embodiment of the invention.
• FIG. 14 shows a schematic sectional view of a prechamber spark plug according to a tenth preferred exemplary embodiment of the invention.
• FIG. 15 shows a schematic sectional view of a prechamber spark plug according to an eleventh preferred exemplary embodiment of the invention.
• a prechamber spark plug 1 according to a first preferred exemplary embodiment of the invention is described in detail below with reference to FIG.
• the prechamber spark plug 1 comprises a center electrode 2 and a ground electrode 3.
• the center electrode 2 lies in a center axis X-X of the prechamber spark plug 1.
• the center electrode 2 comprises a first precious metal body 20 which is, for example, a cylinder.
• the first precious metal body 20 has a first sparking surface 21 on the end face.
• the first noble metal body 20 is arranged in a blind hole 22 in the center electrode base body 2a.
• the first noble metal body 20 can be fixed to the center electrode base body 2a by, for example, welding or press fitting.
• the ground electrode 3 has a second precious metal body 30 . How out
• the second noble metal body 30 is on one end of the Fixed ground electrode 3, preferably also by welding.
• a second end-side spark surface 31 of the second precious metal body 30 lies parallel to the first end-side spark surface 21 of the first precious metal body 20.
• the two spark surfaces 21, 31 are arranged parallel to the central axis X-X of the prechamber spark plug 1.
• the prechamber spark plug 1 also includes a housing 4, an insulator 5 and a cap 6. As can be seen from Figure 1, part of the housing 4 and the cap 6 define a prechamber 7 of the prechamber spark plug, in which the center electrode 2 and the ground electrode 3 are arranged to generate sparks.
• a plurality of cap holes 60 are provided in the cap 6 in order to feed an ignited gas mixture through the cap holes into a combustion chamber of an internal combustion engine and there to trigger a main ignition of the gas mixture located in the combustion chamber.
• the housing 4 has a through opening 40 in which the ground electrode 3 is fixed, for example by means of a press fit 41.
• the ground electrode can also be connected to the housing 4 by means of welding.
• the two end faces 21, 31 face each other parallel to the central axis X-X at a predetermined distance.
• the first precious metal body 20 is arranged laterally on the center electrode 2 .
• the second precious metal body 30 is arranged on the ground electrode 3 at the end face.
• the ground electrode 3 is fixed in the housing 4 at an angle of 90° to the central axis X-X.
• the first noble metal body 20 is welded radially into the blind hole 22 . It should be noted, however, that it is also possible for the first precious metal body 20 to be completely melted and alloyed with the base material of the center electrode 2 at the transition region of the two materials, as a result of which a region containing a high amount of precious metal is present on the center electrode 2, which is directed towards the ground electrode 3 is.
• the first and second precious metal bodies 20, 30 are cylindrical bodies (pins) which preferably have the same dimensions. As a result, mass production can be further reduced in cost.
• a prechamber spark plug 1 can be provided which has reduced wear through the use of the two noble metal bodies 20, 30, the necessary noble metal volume being nevertheless minimized and the prechamber spark plug being able to be provided very cost-effectively as a result.
• FIGS. 2 and 3 show a prechamber spark plug 1 according to a second preferred embodiment of the invention. Identical or functionally identical parts are denoted by the same reference symbols as in the first exemplary embodiment.
• the center electrode 2 of the second exemplary embodiment has a lateral flattening 23 on the outer circumference of the free end of the center electrode.
• the flattened area 23 is provided at a position on the center electrode 2 which is directed towards the ground electrode 3 .
• the first precious metal body 20 is arranged on the flattening 23 . This can be done, for example, by welding the first precious metal body 20 , which is also cylindrical in this exemplary embodiment, to the flattened area 23 . As a result, the first noble metal body 20 is arranged laterally on the center electrode 2 .
• the two end faces 21, 31 of the center and ground electrodes face each other at a predetermined distance and are parallel to the center axis X-X.
• the flattening 23 is provided at the free end 2b of the center electrode 2 . At the flat 23 approximately one third of the diameter of the center electrode material is removed. The first precious metal body is still within an envelope of the originally cylindrical center electrode.
• FIGS. 4 and 5 show a prechamber spark plug 1 according to a third exemplary embodiment of the invention. Identical or functionally identical parts are denoted by the same reference symbols as in the first exemplary embodiment.
• a lateral flattening 33 is provided at the free end of the ground electrode 3, to which the second precious metal body 30 is fixed (cf. FIG. 4).
• the first noble metal body 20 is fixed to an end face of the center electrode 2 .
• the first end spark surface 21 of the first noble metal body 20 and the second end spark surface 31 of the second noble metal body 30 are arranged perpendicularly to the central axis X-X of the prechamber spark plug 1 .
• This arrangement also means that the front spark surfaces 21, 31 are parallel to one another and offer a very compact and space-saving design for the prechamber spark plug 1.
• approximately one third of the ground electrode material for the flattening 33 is also removed and the second precious metal body is located within the original envelope the ground electrode.
• FIG. 6 shows a prechamber spark plug 1 according to a fourth exemplary embodiment of the invention. Identical or functionally identical parts are denoted by the same reference symbols as in the previous exemplary embodiments.
• the first precious metal body 20 is fixed to a holding element 24 in the fourth exemplary embodiment.
• the holding element 24 is in turn fixed laterally to the center electrode 2 .
• a lateral flattening similar to that in the second exemplary embodiment can be provided on the center electrode 2, or, as shown in FIG.
• This configuration has the particular advantage that the first precious metal body 20 can be applied exactly to the holding element 24 outside of the spark plug in a first step.
• the holding element 24 is then connected to the center electrode 2, for example by means of welding.
• the first noble metal body 20 is arranged laterally on the central electrode 2, but with the holding element 24 in between is positioned.
• the holding element 24 is arranged at or near the free end 2b of the center electrode 2 .
• FIG. 7 shows a prechamber spark plug 1 according to a fifth exemplary embodiment of the invention. Identical or functionally identical parts are denoted by the same reference symbols as in the previous exemplary embodiments.
• the fifth exemplary embodiment essentially corresponds to the fourth exemplary embodiment, the first precious metal body 20 being fixed to a holding element 24 again.
• the holding element 24 is arranged on an end face of the free end 2 b of the center electrode 2 . In this way too, a lateral arrangement of the first precious metal body 20 in the direction of the ground electrode 3 can again be implemented.
• the material of the holding member 24 is preferably the same as that for the center electrode base body 2a.
• a geometric shape of the holding element 24 can be chosen freely, but is preferably a cylinder. If the materials chosen for the holding element 24 and the center electrode 2 are the same, the holding element 24 is preferably fixed to the center electrode 2 by means of resistance welding.
• FIGS. 8 and 9 show a prechamber spark plug 1 according to a sixth exemplary embodiment of the invention. Identical or functionally identical parts are in turn denoted by the same reference symbols as in the previous exemplary embodiments.
• the first precious metal body 20 and the second precious metal body 30 of the prechamber spark plug are arranged on the center electrode 2 or the ground electrode 3 in such a way that the front spark surfaces 21, 31 are at an angle a to the center axis XX of the prechamber spark plug are arranged.
• the angle a of this exemplary embodiment is 45°. However, it should be noted that the angle a can also be chosen differently, but is always an acute angle.
• the front end of the center electrode 2 is defined by a bevel 25 on which the first precious metal body 20 is fixed.
• the bevel 25 is also arranged at an angle of 45° to the central axis XX.
• the ground electrode 3 is also arranged at an angle to the central axis XX, which corresponds to the angle of the bevel 25 to the central axis XX.
• an axial length of the prechamber spark plug 1 can be reduced by this arrangement. This also allows the size of the antechamber 7 to be increased or the cap 6 to be made smaller. Otherwise, this exemplary embodiment corresponds to the previous exemplary embodiments, so that reference can be made to the description given there.
• FIGS. 10 and 11 show a prechamber spark plug 1 according to a seventh exemplary embodiment of the invention. Identical or functionally identical parts are in turn denoted by the same reference symbols as in the first exemplary embodiments.
• the seventh exemplary embodiment again has a holding element 24, which in this exemplary embodiment is designed as a ring with an opening 24a.
• FIG. 11 shows a top view of the center electrode 2.
• a diameter of the opening 24a preferably corresponds to an outer diameter of the center electrode base region 2a.
• an axial arrangement of the holding element 24, as indicated by the double arrow A in FIG. 10 can be varied. In this way, tolerances in particular can be compensated for so that the two end-side spark surfaces 21, 31 of the center electrode 2 and the ground electrode 3 are opposite one another in the desired manner.
• the holding element 24 can then be fixed to the central electrode base body, for example by means of a welding process.
• the material of the holding element 24 is preferably the same as the material of the center electrode base body, so that, for example, resistance welding can be used for fixing.
• annular retaining elements 24 have a
• Flattening 24b provided on the outer circumference, to which the first precious metal body 20 is fixed.
• a shoulder on which the annular holding element 24 is attached.
• this also simplifies an alignment in the circumferential direction, since the ring-shaped holding element 24 can simply be rotated onto the shoulder and can then be fastened.
• the paragraph also allows a guided movement in the direction of the central axis XX (axial direction).
• the holding element 24 can also be fixed, for example, by a press fit on the center electrode base body 2a.
• FIG. 12 shows a prechamber spark plug 1 according to an eighth exemplary embodiment of the invention. Identical or functionally identical parts are denoted by the same reference symbols as in the previous exemplary embodiments.
• an arcuate holding element 24 is welded onto an end face of the center electrode 2 in the eighth exemplary embodiment.
• the holding element 24 has a geometric shape of a 90° arc.
• the first precious metal body 20 is fixed to the free end face of the 90° arc, preferably by means of a welded connection.
• the two spark surfaces 21, 31 of the precious metal bodies 20, 30 are again opposite one another in order to generate an ignition spark between them.
• the center electrode base body 2a can also be bent.
• FIG. 13 shows a prechamber spark plug 1 according to a ninth exemplary embodiment of the invention. Identical or functionally identical parts are in turn denoted by the same reference symbols.
• the ninth exemplary embodiment is designed similarly to the eighth exemplary embodiment, but instead of a holding element 24, a first precious metal body 20 is designed directly as a 90° arc.
• the first noble metal body 20 is welded to the end face of the center electrode 2 .
• the spark surfaces 21, 31 of the two precious metal bodies 20, 30 also face one another as a result of this configuration.
• FIG. 14 shows a prechamber spark plug 1 according to a tenth exemplary embodiment of the invention. Identical or functionally identical parts are denoted by the same reference symbols.
• the tenth embodiment is similar to the sixth embodiment with slopes at the first spark face 21 of the first noble metal body 20 and the second end-side spark surface 31 of the second precious metal body 30 is provided.
• the first and second end spark surfaces 21, 31 are arranged at an acute angle to the central axis XX of the prechamber spark plug, preferably at an angle of 45°.
• the ground electrode 3 is arranged perpendicularly to the center electrode 2 . In particular, an axial length of the prechamber spark plug can be reduced by this configuration.
• FIG. 15 shows a prechamber spark plug 1 according to an eleventh exemplary embodiment of the invention. Identical or functionally identical parts are in turn denoted by the same reference symbols.
• the eleventh exemplary embodiment is similar to the tenth exemplary embodiment, but in contrast to the tenth exemplary embodiment, the first precious metal body 20 and the second precious metal body 30 are cylindrical. Here, however, a first slope 25 is provided on the center electrode 2 and a second slope 35 is provided on the ground electrode 3 . This in turn results in the inclined arrangement of the spark surfaces 21, 31 of the two precious metal bodies 20, 30 to the central axis X-X, similar to the tenth embodiment. Otherwise, this embodiment corresponds to the previous embodiments, so that reference can be made to the description given there.
• prechamber spark plugs 1 shown in the exemplary embodiments are preferably provided for automotive applications, in particular with an outer housing diameter of M8, M10 or M12.
• outer housing diameter M8, M10 or M12.
• External thread diameter such as M18, are used.

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Applications Claiming Priority (2)

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• 2020
  • 2020-09-10 DE DE102020211356.4A patent/DE102020211356A1/de active Pending
• 2021
  • 2021-07-13 US US18/044,036 patent/US20230318264A1/en active Pending
  • 2021-07-13 CN CN202180062251.0A patent/CN116075994A/zh active Pending
  • 2021-07-13 EP EP21745306.7A patent/EP4211762A1/de active Pending
  • 2021-07-13 WO PCT/EP2021/069514 patent/WO2022053203A1/de unknown

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