Spark plug connecting element and spark plug

Abstract

A spark plug connecting element. The spark plug connecting element includes a first contact element and a second contact element. A resistor element is situated between the first contact element and the second contact element. The first contact element and the second contact element have a specific conductivity of 10.sup.2 S/m to 10.sup.8 S/m and the resistor element has a specific conductivity of 10.sup.−3 S/m to 10.sup.1 S/m.

Claims

1. A spark plug connecting element, comprising: a first contact element; a second contact element; and a resistor element situated between the first contact element and the second contact element; wherein the first contact element and the second contact element have a specific conductivity of 10.sup.2 S/m to 10.sup.8 S/m, and the resistor element have a specific conductivity of 10.sup.−3 S/m to 10'S/m.

2. The spark plug connecting element as recited in claim 1, wherein the first contact element and/or the second contact element and/or the resistor element is free of metals and carbonaceous compounds.

3. The spark plug connecting element as recited in claim 1, wherein the first contact element and/or the second contact element and/or the resistor element is free of inorganic, nonoxidic, electrically conductive material, metals, and alloys.

4. The spark plug connecting element as recited in claim 1, wherein the first contact element and/or the second contact element and/or the resistor element are made up of at least one first oxide and at least one additive, a total content of the additive with respect to a total mass of the first contact element and/or the second contact element and/or the resistor element being less than 5 mass percent.

5. The spark plug connecting element as recited in claim 1, wherein the first contact element and/or the second contact element and/or the resistor element are made up of at least one first oxide and at least one additive, a total content of the additive with respect to a total mass of the first contact element and/or the second contact element and/or the resistor element being less than 0.5 mass percent.

6. A spark plug connecting element, comprising: a first contact element; a second contact element; and a resistor element situated between the first contact element and the second contact element; wherein the first contact element and/or the second contact element and/or the resistor element containing at least one first oxide selected from a group made up of: (i) oxides of the following formula:
M.sub.1-xD.sub.xO.sub.2 M being selected from Ti, Zr, Sn and combinations of Ti, Zr, Sn, D being selected from V, Nb, Ta, P, As, Sb, Bi and combinations of V, Nb, Ta, P, As, Sb, Bi, and 0<x<0.5, and/or (ii) oxides of the following formula:
Zn.sub.1-yQ.sub.yO, Q being selected from Al, Ga, In, B, Ti, Zr, Hf, Si, Ge, Sn and combinations of Al, Ga, In, B, Ti, Zr, Hf, Si, Ge, Sn, and 0<y<0.5, and/or (iii) oxides selected from the group made up of: ZrO.sub.2-r, TiO.sub.2-r, SnO.sub.2-r, ZnO.sub.1-r, HfO.sub.2-r, V.sub.2O.sub.5-r, Nb.sub.2O.sub.5-r, and Ta.sub.2O.sub.5-r, where 0.5>r≥0.

7. The spark plug connecting element as recited in claim 6, wherein the first contact element and/or the second contact element and/or the resistor element is free of metals and carbonaceous compounds.

8. The spark plug connecting element as recited in claim 6, wherein the first contact element and/or the second contact element and/or the resistor element contains at least one second oxide, which is an inorganic, amorphous oxide.

9. The spark plug connecting element as recited in claim 8, wherein the second oxide is a silicate glass.

10. The spark plug connecting element as recited in claim 8, wherein the first contact element and/or the second contact element and/or the resistor element contains at least one third oxide, which is a crystalline oxide selected from ZrO.sub.2, TiO.sub.2, Al.sub.2O.sub.3 and mixtures of ZrO.sub.2, TiO.sub.2, Al.sub.2O.sub.3.

11. The spark plug connecting element as recited in claim 6, wherein a total content of the first oxide in the first contact element and/or in the second contact element and/or in the resistor element is maximally 100 mass percent, with respect to a total mass of the first contact element and/or the second contact element and/or the resistor element.

12. The spark plug connecting element as recited in claim 6, wherein a total content of the first oxide in the first contact element and/or in the second contact element and/or in the resistor element is 40 mass percent to 95 mass percent with respect to a total mass of the first contact element and/or the second contact element and/or the resistor element.

13. The spark plug connecting element as recited in claim 6, wherein a total content of the first oxide in the first contact element and/or in the second contact element and/or in the resistor element is 60 mass percent to 85 mass percent with respect to a total mass of the first contact element and/or the second contact element and/or the resistor element.

14. The spark plug connecting element as recited in claim 8, wherein a total content of the second oxide in the first contact element and/or in the second contact element and/or in the resistor element is more than 0 mass percent to 75 mass percent with respect to a total mass of the first contact element and/or the second contact element and/or the resistor element.

15. The spark plug connecting element as recited in claim 8, wherein a total content of the second oxide in the first contact element and/or in the second contact element and/or in the resistor element is more than 0 mass percent to 45 mass percent with respect to a total mass of the first contact element and/or the second contact element and/or the resistor element.

16. The spark plug connecting element as recited in claim 8, wherein a total content of the second oxide in the first contact element and/or in the second contact element and/or in the resistor element is more than 20 mass percent to 40 mass percent with respect to a total mass of the first contact element and/or the second contact element and/or the resistor element.

17. The spark plug connecting element as recited in claim 8, wherein a total content of the second oxide in the first contact element and/or in the second contact element and/or in the resistor element is more than 28 mass percent to 38 mass percent with respect to a total mass of the first contact element and/or the second contact element and/or the resistor element.

18. The spark plug connecting element as recited in claim 10, wherein a total content of the third oxide in the first contact element and/or in the second contact element and/or in the resistor element is more than 0 mass percent to 20 mass percent, with respect to a total mass of the first contact element and/or the second contact element and/or the resistor element.

19. The spark plug connecting element as recited in claim 10, wherein a total content of the third oxide in the first contact element and/or in the second contact element and/or in the resistor element is more than 2 mass percent to 10 mass percent, with respect to a total mass of the first contact element and/or the second contact element and/or the resistor element.

20. The spark plug connecting element as recited in claim 10, wherein a total content of the third oxide in the first contact element and/or in the second contact element and/or in the resistor element is more than 3 mass percent to 5 mass percent, with respect to a total mass of the first contact element and/or the second contact element and/or the resistor element.

21. A spark plug comprising a spark plug connecting element, the spark plug connecting element including: a first contact element; a second contact element; and a resistor element situated between the first contact element and the second contact element; wherein the first contact element and the second contact element have a specific conductivity of 10.sup.2 S/m to 10.sup.8 S/m, and the resistor element have a specific conductivity of 10.sup.−3 S/m to 10'S/m.

22. A spark plug comprising a spark plug connecting element, the spark plug connecting element including: a first contact element; a second contact element; and a resistor element situated between the first contact element and the second contact element; wherein the first contact element and/or the second contact element and/or the resistor element containing at least one first oxide selected from a group made up of: (i) oxides of the following formula:
M.sub.1-xD.sub.xO.sub.2 M being selected from Ti, Zr, Sn and combinations of Ti, Zr, Sn, D being selected from V, Nb, Ta, P, As, Sb, Bi and combinations of V, Nb, Ta, P, As, Sb, Bi, and 0<x<0.5, and/or (ii) oxides of the following formula:
Zn.sub.1-yQ.sub.yO, Q being selected from Al, Ga, In, B, Ti, Zr, Hf, Si, Ge, Sn and combinations of Al, Ga, In, B, Ti, Zr, Hf, Si, Ge, Sn, and 0<y<0.5, and/or (iii) oxides selected from the group made up of: ZrO.sub.2-r, TiO.sub.2-r, SnO.sub.2-r, ZnO.sub.1-r, HfO.sub.2-r, V.sub.2O.sub.5-r, Nb.sub.2O.sub.5-r, and Ta.sub.2O.sub.5-r, where 0.5>r≥0.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Exemplary embodiments of the present invention are described in detail below with reference to the figures.

(2) FIG. 1 shows a partially cut-away view of a spark plug according to a first specific example embodiment of the present invention.

(3) FIG. 2 shows a schematic sectional view of a resistor element according to a second specific example embodiment of the present invention.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

(4) In the figures, only the main features of the present invention are represented. All other features have been omitted for the sake of clarity. Moreover, identical components are provided with identical reference numerals.

(5) As is shown in FIG. 1, spark plug 1 according to a first specific embodiment includes a ground electrode 2 and a center electrode 3. An insulator 4 is provided in such a way that center electrode 3 projects slightly from insulator 4 in a conventional way. Insulator 4 itself is partially surrounded by a housing 5. Reference numeral 6 designates an electrical terminal nut 6. Electrical terminal nut 6 provides an electrically conductive connection to center electrode 3 via a connecting bolt 7, a first contact element 9a, a resistor element 8, and a second contact element 9b. First contact element 9a, second contact element 9b, and resistor element 8 situated between first contact element 9a and second contact element 9b are indicated collectively as spark plug connecting element 12. First contact element 9a and second contact element 9b have a specific conductivity of 10.sup.2 S/m to 10.sup.8 S/m. As a result, the voltage transmitted from electrical terminal nut 6 via connecting bolt 7 onto first contact element 9a is transferred largely without resistance. The voltage conveyed from resistor element 8 via second contact element 9b to center electrode 3 is also conveyed largely without loss by second contact element 9b due to the very good conductive properties. In other words, first contact element 9a and second contact element 9b have a high electrical conductivity and, thereby, a low electrical resistance.

(6) Resistor element 8, which is represented in detail in FIG. 2, has a very good oxidation resistance and, associated therewith, a permanently stable resistance value. As a result, not only is the chemical and, thereby, also the mechanical stability of resistor element 8 improved, but also the corresponding properties of spark plug 1. Spark plug 1 therefore also has a long durability when used as intended.

(7) FIG. 2 is a schematic sectional view of resistor element 8 from FIG. 1. Resistor element 8 has a specific conductivity of 10.sup.−3 S/m to 10.sup.1 S/m and includes at least one first oxide 11.

(8) First oxide 11 may be an oxide of the following general formula (1) or mixtures of oxides falling under formula (1):
M.sub.1-xD.sub.xO.sub.2  formula (1).

(9) In formula (1), M is selected from Ti, Zr, Sn and combinations thereof, D is selected from V, Nb, Ta, P, As, Sb, Bi and combinations thereof, and x satisfies the following relation: 0<x<0.5.

(10) Alternatively or in addition to the oxide(s) of the formula (1), first oxide 11 may also include at least one oxide of the following general formula (2):
Zn.sub.1-yQ.sub.yO  formula (2).

(11) In formula (2), Q is selected from Al, Ga, In, B, Ti, Zr, Hf, Si, Ge, Sn and combinations thereof, and y satisfies the following relation: 0<y<0.5.

(12) Alternatively or in addition to the oxide or the oxides of the formulas (1) and (2), first oxide 11 may also include an oxide, which is selected from the group made up of: ZrO.sub.2-r, TiO.sub.2-r, SnO.sub.2-r, ZnO.sub.1-r, HfO.sub.2-r, V.sub.2O.sub.5-r, Nb.sub.2O.sub.5-r, and Ta.sub.2O.sub.5-r. r satisfies the relation 0.5>r≥0.

(13) The aforementioned oxides may each be used individually or also, however, in arbitrary combinations. The total portion of first oxide 11 is, in particular, 60 mass percent to 85 mass percent with respect to the total mass of resistor element 8.

(14) Resistor element 8 is free of inorganic, nonoxidic, electrically conductive materials, metals, and alloys.

(15) In addition to first oxide 11, resistor element 8 also includes at least one second oxide 10, which is an inorganic, amorphous oxide. Second oxide 10 is present in the form of a glass and forms, in part, a matrix for crystalline first oxide 11. As a result, a very high stability of resistor element 8 is achieved. The glass is, in particular, a silicate glass, due to its high stability also at high temperatures.

(16) The total content of second oxide 10 is, in particular, 5 mass percent to 30 mass percent with respect to the total mass of resistor element 8, so that a particularly stable oxidic matrix of resistor element 8 is obtained.

(17) Optionally, resistor element 8 may contain at least one third oxide, which is selected from ZrO.sub.2, TiO.sub.2, Al.sub.2O.sub.3 and mixtures thereof.

(18) Resistor element 8 is distinguished by a particularly high oxidation resistance, so that no degradation of the material of resistor element 8 takes place during the manufacture of a spark plug by utilizing resistor element 8. As a result, the desired resistance value may be kept permanently stable. Resistor element 8 therefore not only has a high chemical stability, but also a very good mechanical stability, also when used as intended.

(19) First contact element 9a and second contact element 9b may be designed similarly to resistor element 8 with respect to the chemical composition, i.e., may also include a first oxide 11, optionally a second oxide 10 and, optionally, a third oxide, as defined above, and, in particular, may be free of metals and carbonaceous compounds. The compositions differ, however, in that first contact element 9a and second contact element 9b have a specific conductivity of 10.sup.2 S/m to 10.sup.8 S/m. This may be achieved with the aid of different dopings of the appropriate oxides or also with the aid of different contents of the oxides. First contact element 9a and second contact element 9b are also distinguished by a good oxidation resistance in combination with a simultaneously very high electrical conductivity.