JP2011080751A - Method for manufacturing glow plug - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To propose a method for manufacturing a glow plug, causing an improved electrical contact connection in a heating element in particular. <P>SOLUTION: The glow plug 110 has at least one heating element 114 including at least one first connection contact 128, and at least one second connection contact 130 for contact connection of the first connection contact. The first connection contact and second connection contact are electrically connected to each other in a connection region 132, at least one electric conductive tablet 146 is used for the electrical connection of the first connection contact to the second connection contact in the connection region, the connection region is surrounded at least partially with a solid ceramic element having characteristics of electric insulation, and subsequently, the solid ceramic element is at least partially crushed and particularly turned into powder in a crushing process. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method of manufacturing a glow plug, in particular a glow plug for use in an internal combustion engine. Furthermore, the present invention relates to a glow plug, and more particularly to a glow plug that can be manufactured by the above method.

  The invention starts from a known glow plug which can be used, for example, in an internal combustion engine, in particular a self-igniting internal combustion engine, for example a diesel engine, which can be realized, for example, as a rod-shaped glow plug. This type of glow plug has a heating element such as a glow pin. The heating element or glow pin may in particular be configured as a ceramic heating element or glow pin.

  The technical approach in known glow plugs is often in the electrical contact connection or contacting of heating elements, for example glow pins. An aspect of contact connection is the use of metal caps in one or more electrical connection contacts. However, this type of contact connection is technically laborious and prone to failure. EP1125086B1 is therefore a rod-shaped glow plug comprising a ceramic glow pin and a connection element that is electrically connected to the ceramic glow pin via a contact connection element or a contact element and serves to supply current Is disclosed. This contact connecting element is formed as a tablet made of electrically conductive powder. The connecting pin is crimped to the contact connecting element, and the contact connecting element is surrounded by an insulating ceramic sleeve. This contact connection has advantages over the known contact connection of rod-like glow plugs in terms of its reliability. However, there are still potential possibilities for improving the strength of electrical connections and for improving seismic strength.

EP1125086B1

  The object of the present invention is therefore to propose a method of manufacturing a glow plug and a glow plug, which results in an improved electrical contact connection, in particular of a heating element.

  In order to solve the above problems, in a method of manufacturing a glow plug, particularly a glow plug for use in an internal combustion engine, according to the present invention, the glow plug includes at least one first connection contact. And at least one second connection contact for contact connection of the first connection contact, and electrically connecting the first connection contact and the second connection contact in a connection region Connected to each other, in which at least one electrically conductive tablet is used for electrical connection between the first connection contact and the second connection contact, the connection region being at least partially Surrounded by a solid ceramic element having electrical insulating properties, followed by a solid ceramic element in a crushing process. At least partially breaking the cement, in particular so as to powdered.

  Preferably, in the crushing step, the solid ceramic element debris, in particular the insulating ceramic powder and advantageously the porous insulating ceramic powder, is at least partially compressed.

  Preferably, the solid ceramic element comprises an insulating ceramic ring, in particular a porous ceramic ring, in particular a one-piece, cylindrical ceramic ring.

  Preferably, the crushing step includes hammering.

  Preferably, the solid ceramic element further at least partially surrounds the first connection contact and / or the second connection contact.

  Preferably, the solid ceramic element has a plurality of individual annular ceramic elements.

  Preferably, the electrically conductive tablet comprises one or more of the following materials in immobilized form: metal powder, in particular silver powder, conductive ceramic powder, graphite.

  Preferably, the first connection contact and / or the second connection contact are plunged into an electrically conductive tablet.

  Preferably, the electrically conductive tablet is additionally at least partially crushed in the crushing step.

  Furthermore, in order to solve the above-mentioned problem, in the glow plug according to the present invention, particularly the glow plug that can be manufactured by the method, at least one heating element including at least one first connection contact, and the first connection At least one second connection contact for contact connection of the contact, wherein the first connection contact and the second connection contact are electrically connected in the connection region via at least one electrically conductive tablet Connected to one another, the connection area is at least partly surrounded by a crushed solid ceramic element having electrical insulating properties, in particular insulating ceramic powder.

  The glow plug may in particular be formed as a rod-like glow plug and is particularly useful for use in an internal combustion engine, preferably a self-igniting internal combustion engine. Since the proposed glow plug can be manufactured or manufacturable in particular according to the proposed method, please refer to the method according to the invention for possible forms of the glow plug.

  The glow plug has at least one heating element, for example at least one glow pin, preferably at least one ceramic heating element. The heating element may have a base made of, for example, a ceramic, and can accommodate at least two connecting portions, for example, one or more heating conductors having at least one positive pole and at least one negative pole. It is. In this regard, reference is made, for example, to known rod-like glow plugs, for example the rod-like glow plugs described in EP1125086B1.

  The heating element includes at least one first connection contact, for example, on one axis of the heating element, a positive pole or a negative pole disposed on the opposite side of the heating element from the combustion chamber. Furthermore, the glow plug comprises at least one second connection contact for contact connection of the first connection contact, for example a second connection contact led from the housing side to the heating element and / or the first connection contact. . The second connection contact may be provided with a plurality of second connection contacts, for example as a flexible or flexible wire and / or connection pins, in whole or in part, That is, it may be configured as a solid member that is substantially shape stable. In particular, the configuration as a connection pin is advantageous within the scope of the present invention. The first connection contact can, for example, simply have a contact point on the surface on the housing side of the heating element and / or have a convex part on this surface and / or an attachment part on this surface. The first connection contact and the second connection contact are electrically connected to each other directly or indirectly in the connection region.

  Unlike known manufacturing methods, the connection area is at least partly surrounded by a solid ceramic element having electrically insulating properties. For example, the solid ceramic element may be configured completely or partially as a ceramic cylinder and / or a ceramic sleeve. The ceramic cylinder and / or the ceramic sleeve is completely or partially fitted over the connection area, thereby completely or partially surrounding the connection area. This may be done, for example, in the housing of the glow plug, or the connection area may be surrounded by such a housing before or after mounting of the solid ceramic element. The housing may comprise, for example, one or more metal cylinders surrounding the connection area and the solid ceramic element.

  In another method step, the solid ceramic element is finally at least partially crushed, in particular powdered. In so doing, the solid ceramic elements are broken down into small components, in particular broken down into ceramic powder. In this way, in a crushing process, which may include, for example, hammering or hammering, but may be configured in another manner, ceramic element debris is formed, which is no longer a solid ceramic element. There are no crushed ceramic elements. That is, the solid ceramic element is formed of a substantially shape-stable, one or more pieces or parts, or a one-piece or multi-piece body that at least partially surrounds the connection area, but is not shattered. Depending on the process, it can be broken down into small debris, for example powder, and adapted to the shape of the connection area, thereby stabilizing the connection area. At the same time, optionally in the crushing step, the ceramic element debris may be at least partially compressed or consolidated. As a result, the connection region and / or the electrical connection between the first connection contact and the second connection contact can be further improved. In the crushing process, the originally solid or shape-stable ceramic element can be completely or partially broken down into ceramic powders with insulating properties, in particular into porous insulating ceramic powders. This ceramic powder can additionally be compressed in the crushing process.

  The solid ceramic element may in principle comprise any shape-stable ceramic element having at least one ceramic material, preferably at least one metal oxide and / or oxide mixture. However, alternatively or additionally, the solid ceramic element may comprise at least one non-oxide ceramic, for example boron nitride. The solid ceramic element may in particular have at least one insulating ceramic ring, ie a rotationally symmetric element. The rotationally symmetric element may be configured, for example, with one or more stages, and in principle may be configured from one or more pieces or parts into one piece or multi-piece. In particular, the insulating ceramic ring may be a porous ceramic ring, the porous ceramic ring having a columnar or stepped outer surface and a columnar or stepped inner surface. . In particular, the ceramic ring may be a one-piece cylindrical ceramic ring made up of one piece or part. In this way, the assembly of the glow plug can be considerably simplified.

  The solid ceramic element completely or partially surrounds the connection area before the crushing process. Furthermore, the solid ceramic element may at least partially surround the first connection contact and / or the second connection contact. Thereby, for example, after the crushing process, the solid ceramic element debris also at least partially surrounds the first connection contact and / or the second connection contact, for example the first connection contact and / or the first connection contact. It can be ensured that the two connection contacts, for example part of the connection pins, can be stabilized and / or fixed with respect to position and / or orientation relative to the connection area.

  The solid ceramic element may be formed from one or more pieces or parts into a one-piece or multi-piece. As described above, the solid ceramic element may be configured to be rotationally symmetric, for example, a columnar shape or a cylindrical shape. As an alternative to the configuration with solid ceramic element steps, it may be purely columnar or cylindrical, or in the form of one or more columnar or cylindrical sleeves configured without steps. Good. If it is desired to be stepped, the solid ceramic element is correspondingly divided into a plurality of individual annular ceramic elements, for example cylindrically configured annular elements, for example with different outer diameters and / or You may have it with an internal diameter. An annular ceramic element of this kind can be realized particularly simply technically.

  For example, as in EP1125086B1, within the scope of the present invention, an electrically conductive tablet is used in the connection area for the electrical connection of the first connection contact and the second connection contact. For example, at least one electrically conductive tablet can be arranged between the first connection contact and the second connection contact. A tablet can be understood as a shape-stable element, preferably a shape-stable element that is rotationally symmetrical, for example in the form of a cylinder. For example, the tablet may be configured as a pressure molded article or a pressing and / or as an element manufactured according to conventional ceramic manufacturing methods. Conductive tablets have electrically conductive properties. The conductive tablet may comprise, for example, one or more of the following materials in immobilized form: metal powder, in particular silver powder, conductive ceramic powder, graphite. However, alternatively or additionally, other materials can be used.

  The first connection contact and / or the second connection contact may pierce into a fully or partially conductive tablet, unlike the configuration shown in EP1125086B1. For example, the first connection contact may have an element protruding from the heating element, for example, an attachment portion and / or a pin. The attachment and / or pin can be plunged into the electrically conductive tablet. As an alternative or in addition, the second connection contact may pierce completely or partially into the electrically conductive tablet. As described above, the second connection contact is completely or partially sharpened at the end of the connection pin, for example, the heating element, and extends in a cone shape or a cone shape, or a frustum shape or a truncated cone shape. It may be configured as a connection pin extending to The entry of the first connection contact and / or the second connection contact into the electrically conductive tablet can be made, for example, via a recess already present in the electrically conductive tablet. Alternatively, the first connection contact and / or the second connection contact may be introduced, for example press-fitted, into the electrically conductive tablet for the first time during the manufacturing process.

  The electrically conductive tablet may be maintained as a solid, shape stable body in the manufacturing process. However, alternatively, the electrically conductive tablet may be completely or partially destroyed in the manufacturing process. That is, the electrically conductive tablet may be at least partially crushed, for example, during the crushing process, and may have, for example, electrically conductive fragments that are part of the electrical connection after the crushing process. . For example, electrically conductive tablets may be completely powdered during the crushing process, and advantageously compressed during that time.

  Further, in addition to the above-described manufacturing method according to the singular or plural forms, as described above, a glow plug that can be manufactured in the above-described singular or plural forms according to the method of the present invention is proposed. The glow plug comprises at least one heating element comprising at least one first connection contact and at least one second connection contact for direct or indirect contact connection or connection of the first connection contact. The first connection contact and the second connection contact are electrically connected to each other via at least one electrically conductive tablet in the connection region. An electrically conductive tablet can exist as a tablet in the above sense, ie as a solid shape-stable body. However, alternatively or additionally, the electrically conductive tablet may already exist in a crushed form, as described above. In that respect, the concept of a tablet is more broadly understood in the sense of the proposed product, unlike the method described above, since the tablet may exist in at least a partially powdered state. Should be. As mentioned above, in the proposed glow plug, the connection region is at least partly crushed ceramic elements having electrically insulating properties, in particular insulating ceramic powder, for example porous insulating ceramic powder. Besieged by.

The proposed manufacturing method and the proposed glow plug have a number of advantages over known glow plugs and methods. The contact connection of a heating element, such as a ceramic heating element, in particular a silicon nitride (Si ₃ N ₄ ) heating element, with a sensitive brazed metal wire connection, as found in many known rod-like glow plugs, It can be omitted. As a result, the electrical connection is mechanically considerably stabilized and strengthened. Furthermore, improved heat derivation can be achieved from the connection area, for example via crushed ceramic elements surrounding the connection area. The assembly process, in particular the pre-assembly for the brazing process and the final assembly of the heating element, is clearly simplified and configured to be resistant to failure.

  Other possible details of the invention are described in the following embodiments schematically shown in the drawings.

It is a figure which shows the glow plug equivalent to a prior art. It is a figure which shows one Embodiment of the glow plug which concerns on this invention. It is a figure which shows another embodiment of the glow plug which concerns on this invention. It is a figure which shows another embodiment of the glow plug which concerns on this invention. It is a figure which shows another embodiment of the glow plug which concerns on this invention.

  1 to 5 show different glow plugs 110. Here, the glow plug 110 is formed as a rod-like glow plug 112. The glow plug 110 is shown in FIGS. 1 to 5 in a cross-sectional view parallel to the axis. FIG. 1 shows an example of the glow plug 110 corresponding to the prior art. In contrast, the structure of the glow plug 110 according to the present invention and the manufacturing method according to the present invention will be described with reference to FIGS.

Each of the glow plugs 110 has one heating element 114. The heating element 114 may be formed as a ceramic glow pin 116, for example. The glow pin 116 can enter the combustion chamber of the internal combustion engine. The glow pin 116 may be formed as a silicon nitride (Si ₃ N ₄ ) glow pin, for example. However, alternatively or additionally, other materials, such as other ceramic materials, may be included and / or the heating element 114 may be in a different form than that shown in FIGS. It may be configured.

  In the example shown in FIGS. 1 to 5, the heating element 114 is accommodated in the housing 118 and thus protrudes from the housing 118 on the combustion chamber side. For this purpose, the housing 118 can have a receiving part 120. The accommodating part 120 may be formed as an attachment part provided in the housing body 122, for example. The housing part 120 forms a housing area 124. The accommodation region 124 is isolated from the inner chamber 126 of the housing body 122 in the glow plug 110 corresponding to the prior art shown in FIG. 1, in which the accommodation portion 120 is formed as an attachment portion provided in the housing body 120. Configured. On the other hand, in the form according to the present invention shown in FIGS. 2 to 5, the accommodation region 124 and the inner chamber 126 are advantageously connected to each other. For example, the accommodating part 120 can be integrally coupled to the housing body 122. For example, the housing 120 can still be formed as an attachment provided on the housing body 122, but consistently, for example, as a sleeve comprising the housing body 122, eg, a sleeve or tube having a step. It may be configured as a shaped sleeve. This may be realized, for example, such that the housing body 122 is formed entirely as a support tube (Stutzrohr), which is also preferably a one-piece or one-piece housing part 120. The inner diameter of the support tube as a whole may be substantially constant even in the accommodating portion 120, unlike the case shown in the drawing. For example, the wall thickness of the support tube, and thus only the outer diameter of the support tube, may increase behind the stepped portion at the transition portion to the accommodating portion 120.

  The heating element 114 may have, for example, one or a plurality of heating elements such as a heating conductor therein. These heating elements not shown in FIGS. 1 to 5 may have a positive contact and a negative contact, for example. One of the contacts, for example, the minus contact, can be contact-connected or contacted via the housing 118, particularly the accommodating portion 120, on the peripheral surface, for example. The other of the contacts forms a first connection contact 128, for example, a positive contact. In the illustrated embodiment, the contact is formed on the surface of the heating element 114 as a simple contact point, for example. This first connection contact 128 must be electrically connected to the second connection contact 130 in the connection region 132. The second connection contact 130 may for example be configured as a rigid, shape-stable connection contact, in particular as a connection pin 134. In the present embodiment, the connecting pin 134 extends away from the glow pin 116 through the housing 118 in the axial direction, and protrudes from the housing 118 on the back surface of the glow plug 110 in the drawing shown symbolically. However, in reality, the connection pins 134 generally do not protrude from the housing 118, and are connected to a connector, such as a round connector, for example, inside the housing via one or more other connections. Yes.

  The present invention mainly relates to the connection between the first connection contact 128 and the second connection contact 130. In the example according to the prior art shown in FIG. 1, the rod-like glow plug 112 is contact-connected or contacted via, for example, a metal “cap-Verbundung”. The cap connection is extremely sensitive. This “cap connection” has a metal cap 136. The metal cap 136 is brazed to, for example, the first connection contact 128, particularly a positive contact. Furthermore, a wire 138 is provided on the first connection contact 128. The wire 138 has a coil shape at the end. A connection pin 134 is screwed into the wire 138. The threading is symbolically indicated by reference numeral 140 in FIG. However, a very sensitive braze or wire 138 failure may occur during screwing. Reuse and / or repair of the rod glow plug 112 is generally no longer possible.

  After the connection pins 134 are screwed into the wires 138, in the prior art, the connection areas 132 are fixed by filling the ceramic powder 142. This anchoring is reinforced by hammering or hammering of the housing 118 with powder filling. The diameter of the housing body 122 is also reduced. The powder filling of the ceramic powder 142 is held and compressed by the seal ring 144 on the side opposite to the glow pin 116. The seal ring 144 may have an insulating function of the connection pin 134 with respect to the housing 118. In addition, this compression step forces the metal cap 136 against the glow pin 116 and thus stabilizes the connection.

In contrast, FIGS. 2 to 5 show an embodiment of the glow plug 110 according to the present invention. Various variations of the method according to the invention will be described with reference to these embodiments. In these embodiments, an electrically conductive tablet 146 is used for electrical connection between the first connection contact 128 and the second connection contact 130. The electrically conductive tablet may comprise, for example, graphite and / or metal powder, such as silver powder and / or conductive ceramic powder and / or conductive intermetallic compound, such as MoSi ₂ . In the illustrated embodiment, the second connection contact 130 in the form of a connection pin 134, which may be sharpened at the end on the side of the electrically conductive tablet 146, is provided within the slightly electrically conductive tablet 146. Has entered.

  When the glow plug 110 is manufactured, the electrically conductive tablet 146 is surrounded by a solid ceramic element 148 configured as an insulating ceramic ring 150 in the present embodiment. The fixed ceramic element 148 or the insulating ceramic ring 150 is made of, for example, a porous ceramic material having electrical insulating properties.

  As can be seen in these embodiments, a portion of the connection pin 134 may also be surrounded by a solid ceramic element 148. This element is disposed in the housing 118 as described. On the side opposite the glow pin 116, the assembly can still be closed by a seal ring 144, similar to the example shown in FIG. Again, the seal ring 144 may have particularly electrically insulating properties.

  The embodiment according to FIGS. 2-5 differs particularly with respect to the construction of the housing 118 and in part with the construction of the insulating ceramic ring 150 and, in some cases, the construction of the electrically conductive tablet 146. That is, in the embodiment according to FIGS. 2 and 3, the heating element 114 protrudes into the inner chamber 126 of the housing body 122 in the embodiment according to FIG. The difference is that the body 114 is completely disposed within the receiving area 124. Correspondingly, in the embodiment according to FIG. 2, the electrically conductive tablet 146 can also be slightly penetrated into the receiving area 124. Furthermore, these embodiments differ in the construction of the solid ceramic element 148. In the embodiment according to FIGS. 2 and 3, the solid ceramic element 148 is configured, for example, from one piece or part in one piece, and has, for example, a columnar outer surface. This outer surface can be adapted to the inner contour of the housing body 122. In both embodiments, the solid ceramic element 148 is adapted to the outer peripheral surface of the electrically conductive tablet 146 and the outer peripheral surface of the connecting pin 134, for example in the case of the electrically conductive tablet 146 and the connecting pin 134. Each has an inner contour which may have two columnar sections, each having a different diameter, corresponding to each different diameter.

  The embodiment according to FIG. 4 shows that the solid ceramic element 148 may be composed of multiple pieces or parts into multi-pieces. That is, the solid ceramic element 148 has an inner diameter adapted to the outer diameter of the electrically conductive tablet 146 in the illustrated embodiment, and the first ceramic ring 152 surrounding the electrically conductive tablet 146 and A second ceramic ring 154, which is preferably connected directly to the first ceramic ring 152 and whose inner diameter may be adapted to the outer diameter of the connecting pin 134. The outer contour of the ceramic rings 152, 154 may be equal to the inner contour of the housing 118. This multi-piece configuration of the solid ceramic element 148 can facilitate the manufacture of the ceramic rings 152, 154 and / or be configured at a lower cost. Further, the assembly of the glow plug 110 can be simplified.

  Finally, in the embodiment according to FIG. 5, the outer shape of the solid ceramic element 148 is adapted to the inner contour of the housing 118. In this case, the solid ceramic element 148 protrudes into the housing portion 120 of the housing 118 because the connection region 132 is partially disposed in the housing portion 120. Again, the inner contour of the solid ceramic element 148 may be adapted to the outer contour of the electrically conductive tablet 146 and / or the connecting pin 134.

  In all the embodiments according to FIGS. 2 to 5, the solid ceramic element 148 can be manufactured, for example, from an insulating ceramic material. In particular, the insulating ceramic material may be a porous insulating ceramic material. 2 to 5 show an intermediate process when the glow plug 110 is manufactured. In these situations, the solid ceramic element 148 is shown in an unbroken state, that is, in a solid state. Following the enclosing of the connection region 132 by the solid ceramic element 148, the solid ceramic element 148 can be crushed and optionally compressed, for example, in a hammering process. This process is a contact connection design or a contact design that can be technically robust. During the hammering process, ceramic powder is advantageously produced from the solid ceramic element 148. The ceramic powder can be compressed at the same time.

  The embodiment according to FIGS. 3 and 5 in which a solid ceramic element 148 is further extended to the glow pin 116 between the electrically conductive tablet 146 and the tube wall of the housing 118 is an electrical short circuit. Strengthen the protection of the glow plug 110 against. In the embodiment according to FIG. 4, the solid ceramic element 148 is composed of a plurality of pieces, in this embodiment, two pieces as compared with the embodiment according to FIG. Have.

  As described above, the connection pins 134 may pierce into the electrically conductive tablet 146, for example. The electrically conductive tablet 146 can also be completely or partially broken down into debris, such as a powder, and possibly compressible, in a crushing process, such as a hammering process. As an alternative to the illustrated embodiment, in principle a wire 138 may be used, for example connected to the connection pin 134, eg connected by making a connection similar to FIG. . Instead of the connecting pins 134, a wire may optionally pierce into the electrically conductive tablet 146. In the case of contact connection using a wire, this wire can be connected to the connection pin 134 on the side of the seal ring 144 opposite to the heating element 114, for example. In this case, the wire and the connection pin 134 together form the second connection contact 130.

  It is advantageous if the glow plug 110 is configured to be flexible. This means in particular that the housing 118 and / or the housing body 122, which can be configured, for example, as a support tube, are bendable. This is preferably done so that the ceramic of the glow pin 116 is not damaged during this bending. To ensure this, the housing body 122 preferably begins at the rear of the ceramic of the glow pin 116. The support tube may be configured to hold the heating element 114 and subsequently press fit into a separate housing. Different forms are possible within the scope of the invention.

  110 Glow Plug, 112 Bar Glow Plug, 114 Heating Element, 116 Glow Pin, 118 Housing, 120 Housing, 122 Housing Body, 124 Housing Area, 126 Inner Room, 128 First Connection Contact, 130 Second Connection Contact, 132 Connection area, 134 connection pin, 136 metal cap, 138 wire, 140 threaded location, 142 ceramic powder, 144 seal ring, 146 tablet, 148 solid ceramic element, 150 ceramic ring, 152 first ceramic ring, 154 second Ceramic ring

Claims (10)

  In a method of manufacturing a glow plug (110), in particular a glow plug (110) for use in an internal combustion engine, the glow plug (110) comprises at least one first connection contact (128) at least one heating element. (114) and at least one second connection contact (130) for contact connection of the first connection contact (128), the first connection contact (128) and the first connection contact (128) Two connection contacts (130) are electrically connected to each other in the connection region (132), and at least one electrically conductive tablet (146) is connected to the first connection contact (128) in the connection region (132). And the second connection contact (130) for electrical connection, and the connection region (132) is at least partially Glow, characterized in that it is surrounded by a solid ceramic element (148) having electrically insulating properties and subsequently at least partly crushed, in particular powdered, in the crushing process. A method of manufacturing a plug, in particular a glow plug for use in an internal combustion engine.   2. The method according to claim 1, wherein said crushing step further compresses at least partly the debris of said solid ceramic element (148), in particular insulating ceramic powder and preferably porous insulating ceramic powder. .   Said solid ceramic element (148) comprises an insulating ceramic ring (150; 152, 154), in particular a porous ceramic ring (150; 152, 154), in particular a one-piece, cylindrical ceramic ring (150; 152). , 154).   The method according to any one of claims 1 to 3, wherein the crushing step includes hammering.   5. The method according to claim 1, further comprising at least partially surrounding the first connection contact (128) and / or the second connection contact (130) by the solid ceramic element (148). The method according to claim 1.   The method according to any one of the preceding claims, wherein the solid ceramic element (148) comprises a plurality of individual annular ceramic elements (150, 152).   7. The electrically conductive tablet (146) comprises one or more of the following materials in immobilized form; metal powder, in particular silver powder, conductive ceramic powder, graphite, The method of any one of Claims.   The method according to any one of the preceding claims, wherein the first connection contact (128) and / or the second connection contact (130) are plunged into an electrically conductive tablet (146).   9. A method according to any one of the preceding claims, wherein the electrically conductive tablet (146) is additionally at least partially crushed in the crushing step.   Glow plug (110), in particular a glow plug (110) that can be produced by the method according to any one of claims 1 to 9, wherein at least one heating element comprising at least one first connection contact (128) (114) and at least one second connection contact (130) for contact connection of the first connection contact (128), the first connection contact (128) and the second connection Contacts (130) are electrically connected to each other in the connection region (132) via at least one electrically conductive tablet (146), the connection region (132) being at least partly electrically insulating. Surrounded by crushed solid ceramic elements (148) with particular properties, in particular insulating ceramic powder And wherein, the glow plug.

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