EP1837595A1 - Ignition module for a combustion chamber assembly of a vehicle heater - Google Patents

Abstract

The module has an ignition body carrier (40) that is held at a combustion chamber housing (12). An air passage opening arrangement (50) is provided in the carrier. The opening arrangement is defined in a longitudinal section of the body. The opening arrangement has an air duct extending from an exterior-front side (58) to an interior-front side (56) of the carrier. The carrier is formed with a ring body in a ring-shape. The ignition body has a heating unit arrangement with a heating unit section that lies in the longitudinal section.

Description

The present invention relates to an ignition assembly for a combustion chamber assembly of a vehicle heater with an ignition device and a Zündorganträger by which the ignition device is to be supported on a combustion chamber housing the combustion chamber assembly.

In vehicle heaters, the combustion chamber assembly is often constructed with a combustion chamber housing which defines a combustion chamber with a peripheral wall and a bottom wall and which generally has a neck or neck in the region of the peripheral wall in which an ignition element, for example a glow plug, is arranged. The inner peripheral wall of this approach and also the inside of the peripheral wall, which limits the combustion chamber, are lined at least in regions with porous evaporator medium. Liquid fuel is fed into this porous evaporator medium in the area of the approach receiving the ignition element, so that where the combustion is to start, that is to say in the volume range to be heated by the ignition element in the starting phase, also increased fuel evaporation will take place. In order to provide an atmosphere in the interior of this approach, which ensures starting of the combustion, at least one air passage opening is provided in this approach, so that not only fuel is fed into the region of this approach, but also at least that air is fed there to start Combustion is required to produce an ignitable mixture. The provision of such an air passage opening or a plurality of such openings in the generally forming an integral part of the metal-made combustion chamber housing approach for the ignition device requires an additional processing operation.

It is the object of the present invention to provide an ignition assembly for a combustion chamber assembly of a vehicle heater, with which in a simple manner, the introduction of air is made possible in the field of Zündorgangs.

According to the invention, this object is achieved by an ignition assembly for a combustion chamber assembly of a vehicle heater, comprising an ignition device and a Zündorganträger to be supported on a combustion chamber housing, wherein in the Zündorganträger an air passage opening arrangement is provided.

In the present invention, therefore, an air passage opening arrangement is formed in the region of the ignition assembly itself, which brings various advantages. On the one hand can be dispensed with it, measures to be provided on the combustion chamber housing, on which the ignition assembly is worn, in order to initiate at least the air required for ignition can. This facilitates the manufacturing process of such a combustion chamber housing. On the other hand, the air to be introduced flows through the spatial proximity of the ignition device and the Zündorganträgers with respect to each other forcibly also very close to the ignition device. In the starting phase, this means that the air can be heated very effectively. After the starting phase, this has the consequence that when no longer energized ignition this is cooled faster by the incoming air, resulting in a longer service life of the ignition.

In order to enhance this effect of the thermal interaction of the incoming air with the ignition, it is further proposed that the air passage opening arrangement is limited at least in a longitudinal section thereof of the ignition device.

For example, it can be provided that the air passage opening arrangement at least one of an outer end face of the Zündorganträgers to an inner end face of the Zündorganträgers extending air passageway comprises.

In a structurally very easy to implement and with respect to the interaction with other modules particularly advantageous embodiment, it is proposed that the Zündorganträger is annularly formed with an annular body which is to be supported with an outer peripheral region of a combustion chamber housing and carries the ignition device in an annular opening. In this case, the air passage opening arrangement adjacent to an inner end face of the Zündorganträgers then have at least one air passage and adjacent to an outer end face of the Zündorganträgers have an air passage ring opening into which the at least one air passageway opens. In such an arrangement, therefore, the at least one air passage channel or its flow cross-section and the concomitant throttling effect at predetermined pressure conditions determines which air quantity flows in. The air passage ring opening has the essential function to lead the air to be introduced as possible without greater flow resistance in the region of the at least one air passage channel. Along with this, the risk of closing the opening arrangement by deposits forming during combustion is essentially limited to the at least one air passage channel, since the air passage ring opening provides a significantly larger flow cross section. However, the spatially or lengthwise comparatively short trained air passageway can be heated very effectively by the thermal interaction with the ignition, so that there possibly deposits can be easily burned.

For example, it can be provided that the air passage ring opening is formed widening in the direction from the inner end face to the outer end face. This means that the air passage ring opening, where it adjoins the at least one air passage channel, namely at its inner end face closer end, has a smaller dimension and thus closer to the ignition device. However, this also means that the air passageway opening there into the air passage ring opening also lies closer to the ignition element and thus can have a stronger thermal interaction with it. It is particularly advantageous if the at least one air passage channel adjacent to the annular opening of the annular body and is limited by the ignition device. In this way, it is possible that the air flowing through the at least one air passage channel can get into direct thermal interaction with the ignition and can be heated very efficiently there or by this very close thermal contact also very good burn-off for possibly forming deposits given are.

The ignition element generally has a heating element arrangement in the inner region, which is electrically excitable. This heating element arrangement can then have a heating element section which is effective for heating and which lies in a longitudinal section of the ignition device carried in the ignition element carrier. In general, care will be taken to ensure that the effective length sections of such a heating element arrangement in the interior volume of the ignition device are effectively positioned to generate high temperatures for heating the mixture to be ignited. An additional heating of the Zündorganträgers would actually mean unnecessary heat loss here. In the structure according to the invention, however, the possibility is created to ensure by comparatively strong heating of the Zündorganträgers on the one hand, a correspondingly strong heating of the inflowing air, and on the other burn off deposits, provided that they arise in the air passage opening arrangement.

The present invention further relates to a combustion chamber assembly for a vehicle heater with a combustion chamber housing and at least one ignition assembly according to the invention carried thereon. The combustion chamber housing may comprise at least one Zündorganaufnahmeansatz in which at least one ignition assembly is supported. In general In this case, the structure is such that this Zündorganaufnahmeansatz opens in a first end region in a combustion chamber and carries the ignition assembly in a second Enbdereich.

In order to be able to receive and appropriately distribute the supplied liquid fuel in the interior region of the combustion chamber assembly, it is further proposed that at least a portion of the ignition element in the ignition organ receiving attachment be surrounded by porous evaporator medium.

Fig. 1

eine Schnittansicht einer Brennkammerbaugruppe mit einem Zündorganaufnahmeansatz;

Fig. 2

einen Schnitt durch den Zündorganaufnahmeansatz längs einer Linie II - II in Fig. 1;

Fig. 3

eine erfindungsgemäß aufgebaute Zündbaugruppe;

Fig. 4

eine Ansicht der in Fig. 3 gezeigten Zündbaugruppe in Blickrichtung IV in Fig. 3;

Fig. 5

eine Ansicht der in Fig. 3 gezeigten Zündbaugruppe in Blickrichtung V in Fig. 3.

The present invention will be described below in detail with reference to the accompanying drawings. It shows:

Fig. 1

a sectional view of a combustion chamber assembly with a Zündorganaufnahmeansatz;

Fig. 2

a section through the Zündorganaufnahmeansatz along a line II - II in Fig. 1;

Fig. 3

an ignition assembly constructed according to the invention;

Fig. 4

a view of the ignition assembly shown in Figure 3 in the direction of view IV in Fig. 3.

Fig. 5

a view of the ignition assembly shown in Fig. 3 in the direction V in Fig. 3rd

In Fig. 1, a combustion chamber assembly shown in section is generally designated 10. This combustor assembly 10 comprises a generally cast metal casing 12 having a peripheral wall 14 and a bottom wall 16 which may be integrally formed with the peripheral wall 14, but may also be provided as a separate assembly. On the peripheral wall 14 is further a Zündorganaufnahmeansatz 18 is provided, which adjoins the peripheral wall 14 in a first end portion 20 and is also formed there integrally with the peripheral wall 14, and which is open in the region of this first end 20 to a limited by the peripheral wall 14 and the bottom wall 16 combustion chamber 22 ,

On the inside 24 of the peripheral wall 14, a porous evaporator medium 26 is provided, which is formed for example of a mesh, a knit, foamed ceramic or other porous material, the liquid fuel in its porous structure, promote by Kapillarförderwirkung and at the combustion chamber 22 free can evaporate lying side. Also on the inside of the Zündorganaufnahmeansatzes 18 porous evaporator medium 28 is provided, which connects in the first end portion 20 of the Zündorganaufnahmeansatzes 18 to the porous evaporator medium 26, so that here a fuel transfer connection is created. It should be noted here that in Fig. 1, the porous evaporator medium 26 and the porous evaporator medium 28 are shown so that they each bear directly against the corresponding inner surface of the peripheral wall 14 and the Zündorganaufnahmeansatzes 18. It is of course possible that, if necessary, a gap may be formed here.

A fuel supply line 30 feeds liquid fuel into the combustion chamber assembly 10 in the region of the ignition organ receiving lug 18. For this purpose, on the inside of this Zündorganaufnahmeansatzes 18 between the first end portion 20 and a second end portion 32 thereof, for example, an annular channel 34 is formed, in which the fuel supply line 30 opens. Thus, this annular channel 34 receives liquid fuel and distributes it circumferentially around the generally toroidal receiving lug 18 formed on the rear side of the porous evaporator medium 28. Thus, over the circumference of the initiator receiving lug 34, a comparatively uniform refueling and injection into the igniter porous evaporator medium 28 ensures.

On or in Zündorganaufnahmeansatz 18 a Zündbaugrupe 36 is also worn. This igniter assembly 36 includes an elongated igniter 38, such as a glow plug, that extends across a substantial length of the igniter-receiving lug and thus protrudes from the second end portion 32 to near the first end portion 20. The ignition member 38 is carried on a Zündorganträger 40, which in turn is supported on the Zündorganaufnahmeansatz 18 in the region of the second end portion 32. As can also be seen in FIG. 2, the ignition element carrier 40 is generally ring-shaped and abuts against the inner surface 44 of the Zündorganaufnahmeansatzes 18 with an outer peripheral surface 42. In order to obtain a stable and nonetheless tight seal, it can be provided here that the ignition element carrier 40 is press-fitted into the ignition element receiving projection 18, so that the essentially planar surfaces 42, 44 are pressed against one another. Of course, it is also possible to provide on the outer circumference of the annular body 46 of the Zündorganträgers 40 a thread which is screwed into an internal thread in the Zündorganaufnahmeansatz 18.

In its central region, the annular body 46 has an annular opening 48 into which the ignition device 38 is inserted. A firm connection of the ignition device 38 with the annular body 46 can be done for example by soldering. For this purpose, it is necessary that both the outer material of the ignition device 38 and the annular body 46 of solderable material, ie metal, is constructed. In particular, the annular body 46 may be constructed of a chromium-steel alloy.

1 and 2 at the ignition assembly further an air passage opening assembly 50. This includes in the example shown two air passageways 52, 54 which are diametrically opposed to each other with respect to the annular opening 48 and from an interior of the Zündorganaufnahmeansatzes 18 to be positioned facing inside Front side 56 too an outwardly positioned to be positioned outer end face 58 of the annular body 46 extend substantially straight therethrough. The air passageways 52, 54 are further positioned in the annular body 46 so that they directly adjoin the annular opening 48 and are thus open over its entire extension length to this annular opening 48. When inserted into the annular opening 48 of the ignition device 38 then the air passageways 52, 54 are limited inwardly by the ignition device 38.

At least the air required for igniting a mixture in the Zündorganaufnahmeansatz 38 can flow under the action of a non-illustrated combustion air blower in the Zündorganaufnahmeansatz 18 and possibly even into the region of the combustion chamber 16 through this passage opening assembly 50 therethrough. 2, the air flows along the surface of the ignition device 38, can there already absorb heat and thus preheated in those volume range in which it then mixed with the fuel vapor emitted from the porous evaporator medium 28 and ignited becomes. As a result of the very high temperatures of more than 600 ° C. generated in the starting mode of a combustion chamber assembly 10 thus constructed in the region of the ignition element, it becomes possible to burn off the deposits possibly forming in the area of the air passage channels 52, 54 during combustion, for example during the starting phase, in which the ignition device 38 is energized, and possibly during certain periods of time repeated Zwischenglühphasen or when switching off the heater. However, due to the fact that the air passes through the air passage opening assembly 50 pre-heated in the inner volume region of the combustion chamber assembly 10, the risk of formation of deposits is already significantly reduced. Also, a significantly improved ignition behavior is achieved with better and more stable flame propagation. After the start of the combustion, the excitation of the ignition device 38 is set. By further passing through the air passage opening assembly 50 passing air, the ignition device 38 is cooled, which contributes to an increased service life of this ignition device 38.

Another advantage of the formed in the Zündorganträger 40 air passage opening assembly 50 is the much simpler design, since the provision of such openings in the Zündorganaufnahmeansatzes 18 can then be dispensed with. It is thus also easier to obtain an adaptation to different types of construction of a combustion chamber assembly by varying the opening cross section in the ignition element carrier 40. Also, the heater can be handled much more flexible in terms of positioning, without thereby producing a negative effect on the air inlet.

An alternative embodiment of an ignition assembly 36 is shown in Figs. 3-5. It can be seen in Fig. 3, the elongated ignition member 38 and the Zündorganträger 40 with its annular body 46. Furthermore, in Fig. 3, a arranged in the interior of the ignition element 38 heating element assembly 60 can be seen, which is fed via an electrical supply line 62 with energy. The heating element arrangement 60 may comprise heating coil sections 64 which are designed in the ignition assembly 36 according to the invention such that they are not only located in the inner portion of the Zündorganaufnahmeansatzes 18 extending longitudinal portion of the ignition device 38, but that they also have a longitudinal portion which is in that range in which the ignition device 38 is located in the annular body 46. In this way, a comparatively strong heating is also generated in this area, with the result that the previously described process of burning off deposits and the heating of air to be introduced can be further improved.

In the embodiment shown in FIGS. 3 to 5, the air passage opening arrangement 50 again comprises the two previously discussed air passageways 52, 54, which, however, starting from the inner end face 56 of the annular body 46 only via a Extending portion of the annular body 46 in the longitudinal direction of the ignition device 38 extend. The here comparatively short trained and inwardly again through the firing member 38 limited air passageways 52, 54 then open into an air passage opening 66, which extends from the outer end face 58 in the direction of the inner end face 56 and the air passageways 52, 54. This air passage ring opening 66, as can be seen in FIG. 5, preferably extends around the entire circumference of the ignition device 38 and thus provides a comparatively large air flow cross section, which is large compared to the total flow cross section provided by the two air passageways 52, 54. Furthermore, it can be seen that the air passage ring opening 66, starting from the junction of the air passageways 52, 54 expands in the direction of the outer end face 58, ie widens conically, this being an extension in the sense of increasing distance from the outer periphery of the ignition, which of course even a width increase of the ring opening can be superimposed on itself.

This configuration of the air passage opening arrangement, the air flow characteristic, ie the throttle effect, essentially determined by the flow cross section of the two air passageways 52, 54. These comparatively short air passageways 52, 54 are also subject by their immediate adjacency to those volume range in which start the combustion or will take place, the greater risk of deposition of incineration residues. Since these relatively short channels are directly in contact with the ignition device 38, they can be easily burned by heating the ignition device 38 to a temperature of about 600 ° C, at least during start-up, but otherwise possibly required intermediate annealing or after-run after completion of the combustion operation become. Since the air passage ring opening 66 adjoining these air passageways 52, 54 has a significantly larger flow cross section, essentially no deposits will form there.

It goes without saying that various variations can be made to the above-described ignition assembly or the combustion chamber assembly containing it, without departing from the essence of the invention. For example, the number of air passageways be different than two, but a symmetrical arrangement with respect to the longitudinal center axis of the ignition device due to the most uniform possible introduction of the air in the Zündorganaufnahmeansatz is advantageous. It is also self-evident that the cross-sectional shape of the air passageways and of course the air passage ring opening can be varied. Although the direct contact of the air passageways with the ignition device is advantageous with respect to the aspects described above, it is also possible to provide these air passageways as passageways spaced apart from the annular opening of the ignition element carrier, for example in the form of bores. It is also possible that the combustion chamber assembly may have more than one Zündorganaufnahmeansatz. The introduction of the liquid fuel can also take place at a different position in the Zündorganaufnahmeansatz or it can also be provided a plurality of fuel supply lines that feed fuel at different positions in the Zündorganaufnahmeansatz, for example, in coordination with the positioning of air passageways. Furthermore, it is possible that, in addition to the air passage opening arrangement, which may serve, for example, primarily the introduction of the air required for ignition, even openings are present in the combustion chamber 22 through which the then required to carry out the normal combustion air is fed directly into the combustion chamber can be.

The air passage opening arrangement could further comprise an air passageway inclined with respect to the ignition member, which can be limited inwardly at its inner end side end portion by the ignition member, as shown in the embodiment of Figs. 3 to 5, and to the outside towards an increasing distance from the Can have ring opening in Zündorganträger. If at the same time it is ensured that an air passageway formed in this way has an increasing flow cross-section in the direction of the outer end face, a similar effect can thus be achieved, as by the combination of the comparatively short air passageways shown in FIGS. 3 to 5 with the funnel-like manner expanding ring opening.

Claims (12)

Igniter assembly for a combustion chamber assembly of a vehicle heater, comprising an ignition device (38) and a Zündorganträger (40) to be supported on a combustion chamber housing (12), wherein in the Zündorganträger (40) an air passage opening arrangement (50) is provided. Ignition assembly according to claim 1,
characterized in that the air passage opening arrangement (50) is delimited by the ignition device (38) at least in a longitudinal section thereof. Ignition assembly according to claim 1 or 2,
characterized in that the air passage opening arrangement (50) comprises at least one of an outer end face (58) of the Zündorganträgers (40) to an inner end face (56) of the Zündorganträgers (40) extending air passageway (52, 54). Ignition assembly according to one of claims 1 to 3,
characterized in that the Zündorganträger (40) is annularly formed with an annular body (46) which is to be supported with an outer peripheral portion of a combustion chamber housing (12) and in an annular opening (48) carries the ignition member (38). Ignition assembly according to claim 4,
characterized in that the air passage opening arrangement (50) adjacent to an inner end face (56) of the Zündorganträgers (40) has at least one air passageway (52, 54) and adjacent to an outer end face (58) of the Zündorganträgers (40) an air passage ring opening ( 66) into which the at least one air passage channel (52, 54) opens. Ignition assembly according to claim 5,
characterized in that the air passage ring opening (66) in the direction of the inner end face (56) to the outer end face (58) is widening. Ignition assembly according to claim 5 or 6,
characterized in that the at least one air passage channel (52, 54) adjacent to the annular opening (48) of the annular body (46) and is limited by the ignition member (38). Ignition assembly according to one of claims 1 to 9,
characterized in that the firing member (38) includes a heating element assembly (60), and in that the heating element assembly (60) comprises a heating element portion effective for heating disposed in a length of the firing member (38) carried in the firing member support (40). A combustor assembly for a vehicle heater, comprising a combustor shell (12) and at least one igniter assembly (36) as claimed in any one of the preceding claims. Combustor assembly according to claim 9,
characterized in that the combustion chamber housing (12) comprises at least one Zündorganaufnahmeansatz (18), in which an ignition assembly (36) is supported. Combustion chamber assembly according to claim 10,
characterized in that the Zündorganaufnahmeansatz (18) in a first end region (20) opens into a combustion chamber (22) and in a second end region (32) carries the ignition assembly (36). Combustion chamber assembly according to claim 11,
characterized in that at least a portion of the ignition member (38) in the Zündorganaufnahmeansatz (18) of porous evaporator medium (28) is surrounded.

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