Spark plug with multi-step insulator seat
阅读说明:本技术 具有多梯级的绝缘体支座的火花塞 (Spark plug with multi-step insulator seat ) 是由 M.赫茨贝格 C.希梅尔 于 2018-04-11 设计创作,主要内容包括:本发明涉及一种火花塞(1),该火花塞具有:壳体(2);布置在所述壳体(2)的内部的绝缘体(3),其中所述绝缘体(3)具有纵轴线(X)、绝缘体托架(31)、绝缘体本体(32)和绝缘体头部(33)以及形成从所述绝缘体托架(31)到所述绝缘体本体(32)的过渡区的绝缘体托架(35);布置在所述绝缘体(3)的内部的中心电极(4);布置在所述壳体(2)的面向燃烧室的端面上的地电极(5),其中所述地电极(5)和所述中心电极(4)如此布置,使得这两个电极构成点火间隙,其中所述壳体(2)在其内侧面上具有壳体支座(25),所述绝缘体(3)以其绝缘体托架(35)安放在所述壳体支座(25)上,其中在所述壳体支座(25)与所述绝缘体托架(35)之间布置有内密封件(10),使得所述内密封件(10)、所述壳体支座(25)和所述绝缘体托架(35)形成密封系统,其中,所述绝缘体托架(35)具有至少一个梯级,所述梯级具有第一区段(3510)和至少一个第二区段(3520),其中所述第一区段(351)和所述第二区段(3520)相对于彼此具有大于0°的角度γ,并且所述第一区段(3510)平行于所述绝缘体纵轴线(X),其中所述内密封件(10)抵靠在这个第一区段(3510)上,从而在所述绝缘体(3)上构成径向的密封面(351)。(The invention relates to a spark plug (1) having a housing (2), an insulator (3) arranged inside the housing (2), wherein the insulator (3) has a longitudinal axis (X), an insulator carrier (31), an insulator body (32) and an insulator head (33) and an insulator carrier (35) forming a transition from the insulator carrier (31) to the insulator body (32), a central electrode (4) arranged inside the insulator (3), a ground electrode (5) arranged on an end face of the housing (2) facing a combustion chamber, wherein the ground electrode (5) and the central electrode (4) are arranged such that these two electrodes form an ignition gap, wherein the housing (2) has a housing seat (25) on its inner side, the insulator (3) rests with its insulator carrier (35) on the housing seat (25), wherein a seal (10) is arranged between the housing seat (25) and the insulator carrier (35) such that the inner seal (10), the housing seat (25) and the insulator carrier (35) form a seal 3535) which forms a seal system of at least one seal between the inner seal (10) and the insulator carrier (3535) which has a sealing surface (3534) which forms a sealing surface of the second insulator carrier (3620) which is arranged parallel to the longitudinal axis (365910) and/or between the insulator carrier (3535) and the insulator carrier (355920) which forms at least one another insulator carrier () and the insulator carrier (3590) and the insulator carrier (3620) which forms a sealing surface of the second insulator carrier (355920) which forms a sealing surface of the insulator carrier (3620) which is arranged at least the second insulator carrier (355920) which.)
1. A spark plug (1) having
A housing (2);
an insulator (3) arranged inside the housing (2), wherein the insulator (3) has a longitudinal axis (X), an insulator bracket (31), an insulator body (32) and an insulator head (33) and an insulator bracket (35) forming a transition from the insulator bracket (31) to the insulator body (32);
a central electrode (4) arranged inside the insulator (3);
a ground electrode (5) arranged on the end face of the housing (2) facing the combustion chamber, wherein the ground electrode (5) and the center electrode (4) are arranged in such a way that these two electrodes form an ignition gap, wherein the housing (2) has a housing mount (25) on its inner face, on which the insulator (3) rests with its insulator carrier (35), wherein an inner seal (10) is arranged between the housing mount (25) and the insulator carrier (35) in such a way that the inner seal (10), the housing mount (25) and the insulator carrier (35) form a sealing system,
it is characterized in that the preparation method is characterized in that,
the insulator carrier (35) has at least steps with a section (3510) and at least second sections (3520), wherein the section (351) and the second section (3520) have an angle γ of more than 0 ° relative to each other, and the section (3510) is parallel to the insulator longitudinal axis (X), wherein the inner seal (10) rests on this section (3510), forming a radial sealing surface (351) on the insulator (3).
2. The spark plug (1) of claim 1, wherein the step on the insulator carrier (35) has, in addition to the radial sealing surface (351), at least axial sealing surfaces (352), in particular the axial sealing surfaces are formed on at least second sections (3520) of the step.
3. A spark plug (1) according to claim 2, characterized in that the radial sealing surface (351) is arranged between two axial sealing surfaces (352 a, 352 b).
4. The spark plug (1) of any of the preceding claims, wherein the insulator bracket (35) has a plurality of steps, each step having a th section (3510), the th section forming with the inner seal (10) a plurality of radial seal faces (351 a, 351b, 351 c).
5. The spark plug (1) of claim 4, wherein the plurality of radial sealing surfaces (351 a, 351b, 351 c) are connected by axial sealing surfaces (352 a, 352b, 352 c), respectively.
6. The spark plug (1) of any of claims 3 to 5, wherein there is a radial main sealing surface (351 a) on the insulator carrier having at least radial secondary sealing surfaces (351 b, 351 c) for a plurality of radial sealing surfaces and/or an axial main sealing surface (352 a) on the insulator carrier having at least axial secondary sealing surfaces (352 b, 352 c) for a plurality of axial sealing surfaces.
7. The spark plug (1) of any of the preceding claims, wherein the second section (3520) of the step on the insulator bracket (35) has an angle γ of 90 ° to 175 ° with respect to the insulator longitudinal axis (X).
8. The spark plug (1) of claim 7, wherein all second sections (3520) of steps have the same angle γ with respect to the insulator longitudinal axis (X).
9. The spark plug (1) of any of the preceding claims, wherein the housing abutment (25) spans an angle β with respect to the insulator longitudinal axis (X), wherein β has a value of at least 80 ° and a maximum of 170 °, in particular between 90 ° and 160 °.
10. The spark plug (1) of any of the preceding claims, wherein the inner seal (10) before installation has a height h in cross section measured parallel to the insulator longitudinal axis (X) and a width d measured perpendicular to the insulator longitudinal axis (X), and wherein the inner seal (10) before installation has a ratio of the width d to the height h of at least 0.5, in particular at least 0.75.
11. The spark plug (1) of any of the preceding claims, wherein the inner seal (10) before installation has a height h in cross section measured parallel to the insulator longitudinal axis (X) and a width d measured perpendicular to the insulator longitudinal axis (X), and the radial sealing surface (351) on the insulator bracket (35) has a height measured parallel to the insulator longitudinal axis (X) which is at least 30%, in particular at least 36%, of the height h of the inner seal (10).
12. The spark plug (1) of of any of the preceding claims 1 to 10, wherein the inner seal (10) before installation has a height h in cross section measured parallel to the insulator longitudinal axis (X) and a width d measured perpendicular to the insulator longitudinal axis (X), and wherein for a plurality of radial sealing surfaces (351 a, 351b, 351 c) on the insulator carrier (35) a radial main sealing surface (351 a) on the insulator carrier (35) has a height measured parallel to the insulator longitudinal axis (X) of at least 30%, in particular at least 36%, of the height h of the inner seal (10).
13. The spark plug (1) of any of the preceding claims, wherein the inner seal (10) before installation has a height h in cross section measured parallel to the insulator longitudinal axis (X) and a width d measured perpendicular to the insulator longitudinal axis (X), and wherein for a plurality of radial sealing surfaces (351 a, 351b, 351 c) on the insulator carrier (35) a radial secondary sealing surface (351 b, 351 c) on the insulator carrier (35) has a height measured parallel to the insulator longitudinal axis (X) of at least 1%, in particular at least 5%, of the height h of the inner seal (10).
14. The spark plug (1) of any of the preceding claims, wherein the inner seal (10) before installation has a height h in cross section measured parallel to the insulator longitudinal axis (X) and a width d measured perpendicular to the insulator longitudinal axis (X), and the inner seal (10) and the housing (2) form an axial sealing surface (252) on the housing mount (25) and a radial sealing surface (251) on the inner side of the housing, wherein the radial sealing surface (251) on the housing (2) has a height measured parallel to the insulator longitudinal axis (X) of at least 30%, in particular at least 36%, of the height h of the inner seal (10).
15. The spark plug (1) of any of the preceding claims, wherein the inner seal (10) before installation has a height h in cross section measured parallel to the insulator longitudinal axis (X) and a width d measured perpendicular to the insulator longitudinal axis (X), and the axial sealing surface (352) on the insulator carrier has a width measured perpendicular to the insulator longitudinal axis (X) of at least 15%, in particular at least 20%, of the width d of the inner seal (10).
16. The spark plug (1) of any of the preceding claims, wherein the inner seal (10) before installation has a height h in cross section measured parallel to the insulator longitudinal axis (X) and a width d measured perpendicular to the insulator longitudinal axis (X), and wherein the axial main sealing surface (352 a) on the insulator carrier (35) has a width measured perpendicular to the insulator longitudinal axis (X) for a plurality of axial sealing surfaces of at least 15%, in particular at least 20%, of the width d of the inner seal (10).
17. The spark plug (1) of any of the preceding claims, wherein the inner seal (10) before installation has a height h in cross section measured parallel to the insulator longitudinal axis (X) and a width d measured perpendicular to the insulator longitudinal axis (X), and wherein the axial secondary sealing surfaces (352 b, 352 c) on the insulator carrier (35) have a width measured perpendicular to the insulator longitudinal axis (X) for a plurality of axial sealing surfaces which is at least 1%, in particular at least 5%, of the width d of the inner seal (10).
18. The spark plug (1) of of any of claims 2 to 17, wherein the axial sealing surface (352 b) on the insulator bracket (35) directly adjoining the insulator bracket has at least a width that corresponds to a particularly narrowest gap width (e) between the insulator bracket (31) and the inner side of the housing opposite the insulator bracket (31).
Technical Field
The invention relates to spark plugs according to the preamble of claim 1, such spark plugs being known, for example, from DE 10344186 Al.
Background
, well functioning spark plugs and their components must meet the series of requirements, such as long life, reliable ignition characteristics, breakdown strength, and gas tightness where conditions such as temperature and pressure in the combustion chamber become more and more extreme, under which the spark plug must function reliably and as long as possible.
Spark plugs of today have series sealing elements and sealing materials for achieving and ensuring the necessary tightness solutions for sealing the gap between the insulator and the housing are shown in fig. 2The insulator seat is mounted on the shell seat with an inner seal, often in the form of a sealing washer or sealing ring, disposed between the two seat surfaces.A line or spark plug longitudinal axis, which typically coincides with the shell longitudinal axis, is inclined at an angle α, α, typically in the range of 55-65, the insulator likewise has a taper of its outer diameter in the direction of its combustion chamber-side end or its insulator seat2The size of (2). This sealing solution has been well tested for temperatures below about 220 ℃ and pressures below about 22 bar in the combustion chamber.
However, the demand for the performance of the motor, and thus the demand for the spark plug, is increasing. In particular in the field of miniaturized motors, to operate at increasingly higher pressures and temperatures, new loads are thus applied to the spark plug. Temperatures below 300 ℃ and pressures below 30bar are increasingly becoming a rule and no longer an exception when operating internal combustion engines.
The tightening torque for screwing the spark plug into the cylinder head has a gap of for achieving a gas-tight transition between the spark plug and the cylinder head, for example, so that today M12 spark plugs are screwed with a tightening torque of up to 60 Nm, whereas previously a tightening torque of 40 Nm would be sufficient.
Disclosure of Invention
However, it has been shown that the previous sealing solutions for the internal tightness, i.e. the gap between the housing and the insulator, approach their limits as the requirements and the forces acting on the spark plug increase, in particular, higher tightening torques are used to lengthen the housing in the region of the screw thread during the installation, in the region of the screw thread the housing support is located on the inner side of the housing, the pretensioning force for pressing the housing and the insulator against one another is reduced by the elongation, as a result of which the inner seal is no longer pressed into the housing and the insulator with sufficient strength, the surface pressure between the inner seal and the insulator or the housing is reduced, and the sealing surface is thus also reduced, and the sealing surface is no longer sufficiently resistant to the high pressures prevailing in the combustion chamber, so that the spark plug has sufficient gas tightness.
The object of the present invention is therefore to further develop a spark plug of the type mentioned at the outset in such a way that the spark plug and in particular the gap between the insulator and the housing are reliably gas-tight even when the temperature and pressure in the combustion chamber increase.
According to the invention, this object is achieved in a spark plug of the type mentioned at the outset in that the insulator mount has at least steps with a section and at least second section, wherein the section and the second section have an angle γ of more than 0 ° relative to one another and the section is parallel to the longitudinal axis of the insulator, wherein the inner seal bears against this section, so that a radial sealing surface is formed on the insulator.
The spark plug according to the invention has a housing, an insulator arranged inside the housing, a center electrode arranged inside the insulator, and a ground electrode arranged on an end face of the housing facing the combustion chamber, wherein the ground electrode and the center electrode are arranged such that the two electrodes form an ignition gap.
The insulator can be divided along its longitudinal axis into three regions, an insulator carrier, an insulator body and an insulator head, the region forming the combustion chamber side end of the insulator is referred to as the insulator carrier.
The housing furthermore has a housing support on its inner side, on which the insulator rests with its insulator support, wherein an inner seal is arranged between the housing support and the insulator support, such that the inner seal, the housing support and the insulator support form a sealing system.
According to the invention, the insulator support has at least steps with a th section and at least second section, wherein the th section and the second section have an angle γ of more than 0 ° relative to each other, and the th section is parallel to the insulator longitudinal axis X, wherein the inner seal rests on this th section, so that a radial sealing surface is formed on the insulator.
The invention relates to a spark plug, in particular a spark plug for a motor vehicle, comprising a housing, an insulator, a radial sealing surface, a housing, a piston rod, a piston.
In the sense of the present application, an axial force or force component is a force which acts parallel to the longitudinal axis of the spark plug. Accordingly, a radial force or force component refers to a force acting perpendicular to the longitudinal axis of the spark plug. The force can be divided into axial and radial force components.
Within the scope of the present application, the word "parallel" is not used in the sense of a narrow geometric word. As "parallel" in particular in connection with the orientation of the planes, small deviations from strict geometric parallelism, such as occur due to uncertainties in the production conditions, are also considered as parallel orientations. For example, a surface or a section is considered to be parallel or substantially parallel to the longitudinal axis of the insulator if said surface or section has an angle of at most 10 ° with respect to the longitudinal axis of the insulator.
Accordingly, all other sealing surfaces that abut a surface or segment oriented perpendicular to or at an angle of degrees relative to the insulator longitudinal axis, the housing longitudinal axis, or the spark plug longitudinal axis are axial sealing surfaces.
Further advantageous embodiments of the invention are the subject matter of the dependent claims.
In an advantageous development of the spark plug, it is provided that the step on the insulator carrier has, in addition to the radial sealing surfaces, at least axial sealing surfaces, in particular the axial sealing surfaces are formed on at least second sections of the step, by enlarging the total sealing surface, a better overall sealing of the inner sealing system is produced, and in addition, the effect is also produced that the axial sealing surfaces, which are influenced primarily by axial forces acting on the insulator, the inner seal and the housing, and the radial sealing surfaces, which are influenced primarily by radial forces acting on the insulator, the inner seal and the housing, are influenced by different components of the pretensioning force, whereby the sealing surfaces can maintain their functionality when their functionality is reduced for the other sealing surfaces, for example, as a result of a reduction in the respective force component.
In general, it has proven advantageous for the step to have an -th section and two second sections, wherein the -th section is arranged between the two second sections, a radial sealing surface is obtained with the inner seal , which is arranged between the two axial sealing surfaces, the resulting advantage being that the inner seal bears against the entire surface of the -th section of the step on the insulator seat and thus forms a radial sealing surface as large as possible on this -th section, furthermore, the total sealing surface is enlarged by the combination of the axial and radial sealing surfaces, and the path through which gas must escape is lengthened due to the angled arrangement of the -th and second sections of the step on the insulator seat, thereby improving the gas tightness of the inner seal system as a whole.
In the preferred embodiment, it is provided that the insulator carrier has a plurality of steps, each of which has a th portion, these th portions forming radial sealing surfaces together with the inner seal , whereby the technical effects and advantages described above work particularly well, especially if, as in the modification of this embodiment, a plurality of radial sealing surfaces are each connected by an axial sealing surface.
In embodiments with a plurality of radial sealing surfaces on the insulator carrier, radial main sealing surfaces are present together with at least radial auxiliary sealing surfaces, in addition or as an alternative to a plurality of axial sealing surfaces, axial main sealing surfaces are present together with at least axial auxiliary sealing surfaces on the insulator carrier, respectively.
The radial main sealing surface is advantageously surrounded by a radial secondary sealing surface along the longitudinal axis of the insulator, the radial sealing surfaces being connected by axial sealing surfaces. The axial main sealing surface can be arranged directly on the radial main sealing surface.
The radial secondary sealing surface can also be formed, for example, on the insulator carrier and/or the insulator body, i.e. the inner seal projects beyond the insulator seat after deformation. The advantage is thereby obtained that the entire surface of the insulator foot is used as a sealing surface, wherein the sealing surface is composed of radial and axial sections of the sealing surface. By the stepped arrangement of the sealing surfaces, the leakage path of the gas is particularly long, as a result of which the spark plug maintains its gas tightness even at high gas pressures.
The precise shape of the inner seal after installation of the spark plug and elastic plastic deformation of the inner seal and the specific configuration of the axial and radial sealing surfaces (number and arrangement) associated therewith, such as, for example, the number and arrangement, depend on various factors, such as, for example, the size of the gap between the insulator and the housing above and below the insulator seat, the number of steps in the insulator seat, the pretension for pressing the insulator into the housing, or the area of the sealing contour. This also results in the possibility of adapting the inner sealing system to the particular loads and requirements by means of a corresponding design of these factors, in order to thereby optimize the spark plug for the respective application.
The present applicant's research has shown that it is advantageous if the second section of the step on the insulator support has an angle γ of at least 90 ° with respect to the insulator longitudinal axis (X), a further study at has shown that the above-described technical effect is achieved in a reproducible manner up to an angle γ of 175 °, it has also been found from the study that for a plurality of second sections of steps or for a plurality of steps the second sections can all have the same angle γ or different angles γ with respect to the insulator longitudinal axis X, this simplifies the manufacture and thus also reduces the manufacturing costs if all the second sections are inclined with the same angle γ with respect to the insulator longitudinal axis.
studies have additionally shown that the housing holder can be extended by an angle β relative to the longitudinal axis X of the insulating body, which can have a value which is considerably greater than in the internal sealing concept according to the prior art, in which typically α is 55 ° -65 °. the angle β is the angle within the housing wall, for the angle α according to the prior art, an angle β of 115 ° to 125 ° is correspondingly obtainedSdTIn the spark plug according to the invention, the internal sealing system according to the invention already functions when β has a value of at least 80 ° and also functions for values below a maximum of 170 ° of β, the values for β are preferably at least 90 ° and a maximum of 160 °SdTTypically only having a width of 10 deg..
In a further advantageous embodiment of the invention, the inner seal, prior to installation, has a height h, measured parallel to the insulator longitudinal axis X, and a width d, measured perpendicular to the insulator longitudinal axis X, in cross section, it has proven advantageous here if the ratio of the width d to the height h of the inner seal is at least 0.5, in particular at least 0.75, the inner seal preferably being a solid body, such as a sealing ring or sealing washer, i.e. the inner seal is not an extruded powder packet.
The width of the inner seal is advantageously greater than the depth of the housing seat. Depth a of the housing seatgInner diameter c of the housing above the housing support or in the direction of sides of the housing facing away from the combustion chambergAn inner diameter b of the housing in the direction of the end of the housing below the housing support, i.e. on the combustion chamber side of the housingg half difference therebetween, depth a of the insulator standoffiIs similarly defined as the outside diameter c of the insulator above the insulator seat, i.e. on the insulator bodyiWith the outside diameter b of the insulator below the insulator foot, i.e. on the insulator carrieri half difference betweeniIs less than or equal to the housing seat agOf the depth of (c).
Furthermore, it is advantageous if the radial sealing surface on the insulator seat has a height, measured parallel to the insulator longitudinal axis X, which is at least 30%, in particular at least 36%, of the height h of the inner seal.
Alternatively, the radial main sealing surface on the insulator foot has a height, measured parallel to the insulator longitudinal axis X, of at least 30%, in particular at least 36%, of the height h of the inner seal for a plurality of radial sealing surfaces on the insulator foot. In addition, it is conceivable for the radial secondary sealing surface on the insulator seat to have a height, measured parallel to the insulator longitudinal axis X, which is at least 1%, in particular at least 5%, of the height h of the inner seal.
For the axial sealing surface, it has proven to be advantageous if the axial sealing surface has a width, measured perpendicular to the insulator longitudinal axis X, on the insulator support, which is at least 15%, in particular at least 20%, of the width d of the inner seal. In the case of a plurality of axial sealing surfaces, the axial main sealing surface on the insulator seat can have a width, measured perpendicular to the insulator longitudinal axis X, of at least 15%, in particular at least 20%, of the width d of the inner seal. In addition or alternatively, the axial secondary sealing surface on the insulator seat can have a width, measured perpendicular to the insulator longitudinal axis X, of at least 1%, in particular at least 5%, of the width d of the inner seal.
In principle, it is possible for the inner seal and the housing to form an axial sealing surface on the housing support and a radial sealing surface on the inner side of the housing. In this case, it has proven advantageous if the radial sealing surface on the housing has a height, measured parallel to the longitudinal axis X of the insulator, which is at least 30%, in particular at least 36%, of the height h of the inner seal.
In an advantageous further development of the invention, the axial (secondary) sealing surface on the insulator foot directly adjoining the insulator foot has at least a width which corresponds to the gap width between the insulator foot and the inner side of the housing opposite the insulator foot, in particular the narrowest gap width, directly at the insulator foot.
Drawings
FIG. 1 illustrates embodiments for a spark plug;
FIG. 2 shows in detail the arrangement of the housing mount, insulator bracket and inner seal of a spark plug according to the prior art;
FIG. 3 shows in detail the stepped insulator carrier, inner seal and housing mount of the spark plug according to the invention prior to installation;
FIG. 4 shows in detail the stepped insulator carrier, inner seal and housing mount of the spark plug according to the invention after installation;
FIG. 5 shows a stepped insulator bracket for a spark plug according to the present invention;
fig. 6 shows exemplary embodiments of a housing mount for a spark plug according to the invention.
Detailed Description
Fig. 1 shows a spark plug 1 in a half-cut view. The spark plug 1 includes a
Between the center electrode 4 and the connecting screw 8, in the insulating
A ground electrode 5 is arranged on the
The
The
Adjoining the
The
The
Fig. 2 shows in detail the
Fig. 3 shows in detail the
In such an embodiment, the
Fig. 4 shows the
A
In this exemplary embodiment, the
Due to the stepped shape of the insulator seat, the sealing surfaces alternate radially and axially.
It is not excluded that a radial sealing surface is also formed on the
It is not necessary that a sealing surface be formed on all sections of the step on the
The axial
FIG. 5 shows the
The