Abstract:
A combustion chamber arrangement, in particular for a burner of a vehicle heating device, includes a housing arrangement in which a seating region is provided for abutment of a counter-seating region formed on an ignition element. An elastically effective retaining element for retaining the ignition element on the housing arrangement, the retaining element having a first support region supported with respect to the ignition element and a second support region supported with respect to the housing arrangement, wherein the retaining element is supported on at least one of the ignition element or the housing arrangement with the production of a substantially sealed closure of an ignition element passage opening of the housing arrangement.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS  
         [0001]    Not applicable.  
         STATEMENT REGARDIGN FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT  
         [0002]    Not applicable.  
         BACKGROUND OF THE INVENTION  
         [0003]    The present invention relates to a combustion chamber arrangement, in particular for a burner of a vehicle, including a housing arrangement, in which a seating region is provided for the abutment of a counter-seating region formed on an ignition element, and also an elastically effective retaining element for retaining an ignition element on the housing arrangement, wherein the retaining element has a first support region supported with respect to the ignition element and a second support arrangement supported with respect to the housing arrangement.  
           [0004]    German Patent Document DE-OS 1 551 681 discloses an ignition element supported on a housing. An ignition element lead-in opening or passage opening is provided in the housing, and the ignition element partially passes through it in the mounted state. The ignition element is held on the housing by a retaining element made of sheet metal and has plural retaining flanges. The retaining flanges then lie against an inner peripheral wall of the ignition element lead-in opening and are supported there by their own elasticity for producing the retaining effect.  
           [0005]    German Patent Document DE 298 02 226 U1 discloses a combustion chamber arrangement for a vehicle heating device, in which an ignition element is retained in an ignition element lead-in opening such that it partially engages with an end region in the combustion chamber, and the end region is effective for igniting a mixture present in a combustion chamber. A clamp-like retaining element ensures that the ignition element is firmly held to the housing of the combustion chamber arrangement. This clamp-like retaining element is pushed on transversely of the longitudinal direction of the ignition element, or in the direction in which the ignition element is pushed into the ignition element lead-in opening.  
           [0006]    European Patent Document EP 0 579 157 B1 discloses an ignition element held on a housing, and a clamp-like spring element is provided that under its elastic prestress fixes the ignition element on the housing.  
         SUMMARY OF THE INVENTION  
         [0007]    The present invention has as its object to provide a combustion chamber arrangement, in particular for a burner of a vehicle heating device, in which better functionality can be achieved in the region of the retaining of an ignition element on a housing.  
           [0008]    This object is attained according to the invention by a combustion chamber arrangement, particularly for a burner of a vehicle heating device, including a housing arrangement in which a seating region is provided for abutment of a counter-seating region formed on an ignition element, and also an elastically effective retaining element for retaining an ignition element on the housing arrangement. The housing element has a first support region supported with respect to the ignition element and a second support region supported with respect to the housing arrangement.  
           [0009]    It is furthermore provided that the retaining element is supported on the ignition element and/or the housing arrangement with the production of a substantially sealed closure of an ignition element passage opening of the housing arrangement.  
           [0010]    The combustion chamber arrangement according to the invention requires that the retaining element for retaining the ignition element on the housing arrangement serves a double function, in that at the same time it also ensures a sealed closure of the housing arrangement in the region of this retention. Thus no additional sealing elements need be provided. This simplifies the structure and reduces the production costs by integration of functions in a single component.  
           [0011]    For example, it can be provided that the retaining element has in its second support region a support projection that (with respect to the ignition element passage opening) abuts at least partially around, and substantially over its whole peripheral length, on the housing arrangement. For achieving a defined cooperative effect between the retaining element and the housing arrangement, it is proposed that a support surface is formed on the housing arrangement, at least locally surrounding the ignition passage opening and associated with the support projection.  
           [0012]    The retaining element and the housing arrangement can be held together against undesired release in that the support projection engages over the support surface like a barb, so that for a satisfactory sealed closure it can be ensured that the support projection has a sealing lip region abutting under prestress against the support surface.  
           [0013]    The retaining element can, for example, be formed like a pot and can have the first support region in a floor region and the second support region in a wall region.  
           [0014]    When the ignition element is prestressed with its counter-seating region in abutment on the seating region by the retaining element, on the one hand, the ignition element is retained in a defined manner with respect to the housing arrangement, and the occurrence of clicking noises can be avoided. On the other hand, this abutment produces an advantageous reaction force for attaining a sealed closure.  
           [0015]    The holding element can be formed of rubber-elastic material. Preferably natural or synthetic rubber materials are used here. Care must be taken that these materials have to be resistant to this surrounding atmosphere and, in addition, must be heat resistant in the temperature range in which such arrangements operate. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]    The present invention is described in detail hereinafter with reference to the accompanying Figure, in which a section of a combustion chamber arrangement is shown. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0017]    A section of a combustion chamber arrangement, generally denoted by the reference numeral  10 , is shown in the Figure. This section shows a portion of a housing arrangement  12 . A housing portion  16  of the housing arrangement  12  bounds a combustion chamber  14 , visible only partially, and has a recess  18  formed with a, for example, circular contour and at least partially receiving in the assembled state a combustion element  20  formed, for example, as a glow ignition pin. A pressure space  19  is formed between the housing portion  16 , already mentioned and bounding the combustion chamber  14 , and a further housing portion  17  connected to this and, for example, even integrally formed. Compressed air is provided via this pressure space  19  by means of a fan for feeding into the combustion chamber  14 . A section  22  of the ignition element  20  that becomes thermally effective for ignition projects at least into the region of the combustion chamber  14  and is surrounded by a porous material  24  formed like a bushing. This porous material  24  is also partially situated in the recess  18  and can be supported on a floor region  26  of this recess  18  in the direction of a long axis L of the same.  
         [0018]    The recess  18  forms a conical seating surface  28 , on which a correspondingly formed counter-seating surface  30  of the ignition element  20  abuts. In this manner, the position of the ignition element  20  with respect to the housing arrangement  12  is defined and fixed. Furthermore, a lead-in opening or passage opening  32  for the ignition element  20  is provided in the housing portion  17  of the housing arrangement  12  as an axial extension of the recess  18 , and the ignition element  20  is guided through the opening  32  when being inserted into the housing arrangement  12 . In the mounted state shown in the Figure, the ignition element  20  projects with its rear end region  34  into the opening  32 . A retaining element  36 , formed like a cap or pot, is pushed over the end region  34  of the ignition element  20 . The retaining element  36  has a floor region  38 , from which a first support region  40  extends to the end region  34  of the ignition element  20  and abuts on this. A wall region  42  adjoins the floor region  38 , surrounds the end region  34  of the ignition element  20 , and is adapted in its shape to the inner peripheral shape of the opening  32 , and thus has, for example, a circular external peripheral form. The wall region  42 , in its end region placed in the direction of the longitudinal axis L of the opening, has a projection  44  annularly running around the latter and standing radially outward. In the assembled state, this projection  44  is substantially completely received in an armular groove-shaped widening  46  of the opening  32 . The projection  44  is formed like a barb, so that in the fitted-in state it is supported with a sealing lip region  48  on a support surface  50 , running annularly around the opening  32  of the housing  12 , or abuts with an outer peripheral surface  52  on a floor wall of the widening  46 .  
         [0019]    The retaining element  36  is produced from rubber-elastic material that is thus elastically deformable. The retaining element  36  is dimensioned such that in the state shown in the Figure it abuts under prestress on both the glow ignition pin  20 , namely with its first support region  40 , and also on the housing arrangement, namely with its projection  44  substantially forming a second support region. It is thereby attained that the ignition element  20  is prestressed with its counter-seating surface  30  in firm abutment contact on the seating surface  28  by the retaining element  36 . Furthermore, a sealed closure of the opening  32  is attained. Contributing to this, the retaining element  38  abuts with its sealing lip region  48  on the support surface  50 , with its outer peripheral surface  52  on the floor region of the widening  46 , and with its substantially conical or frustroconical end surface  54  on a corresponding abutment surface  56  of the housing arrangement  12 . Moreover, the dimensioning of the projection  44  is chosen so that preferably an abutment under elastic prestress occurs in all the three regions previously mentioned. Thus the volume region surrounded by the housing  12  is closed by the retaining element  36  against any materials leaving through the opening  32 , and of course also against any materials entering through the opening  32 . In order to supply the ignition element  20  with electrical energy, it is possible to provide passage openings for electrical leads in the floor region  38  of the retaining element  36 . Particularly when the dimensioning of the retaining element  36  is chosen so that this abuts with its wall region  42 , or with an outer peripheral surface of the same, under prestress on the inner peripheral wall of the opening  32  and simultaneously also under prestress with an inner peripheral surface of the wall  42  at the end region  34  of the ignition element  20 , no sealing problem also arises in the region of the lead-in for the electrical leads, since a sealed closure between the retaining element  36  and the ignition element  20  on the one hand, and the retaining element  36  and the housing  12  on the other hand, is already implemented at a region situated near to the combustion chamber  14 .  
         [0020]    In the combustion chamber arrangement  10 , the retaining element  36  thus fulfills a double function, in that on the one hand, it holds the ignition element  20  in firm contact with the housing arrangement  12 , namely the housing portion  16  of the same and, on the other hand, effects a sealed closure of an opening through which the ignition element  20  is introduced into the housing arrangement  12 . Furthermore, because of the elasticity of the retaining element  36 , this can also compensate for manufacturing tolerances.  
         [0021]    When incorporating the ignition element  20  into the housing arrangement  12 , it can be pushed, together with the retaining element  36  already provided at the end region  34 , through the opening  32  and into the recess  18 , so that the retaining element  36 , while being elastically deformed, and surrounding the end region  34 , enters the opening  32  and latches, expanding elastically, with its projection  44  into the groove-like widening  46 . Alternatively, it is also possible to design the opening  32  in which the retaining element is to be positioned so that it is open transversely of the axis L, and thus, for example, is open upward from the plane of the diagram of the Figure. The retaining element  36  can then be pushed laterally, together with the end region  34  already received therein, into the opening  32 . The opening  32  can thereupon be closed on this side also by a further housing part, for example a housing cover. In this embodiment, the retaining element can be formed so that the projection  44  providing a support region is provided only on that peripheral region, which is received in the opening  32  of the housing portion  17  of the retaining element  36 , which is then not necessarily provided with a circular periphery on the outside. On the side on which a further housing part, for example a housing cover, then ensures closure of the opening  32  and of course also of the pressure space  19 , the retaining element  36  can have a flattened surface that substantially abuts with its full surface on this further housing part. It should also be mentioned in regard to the ignition element  20  that the opening  18  receiving this does not necessarily have to be fully closed in the peripheral direction, but that here likewise, by leaving this opening  18  open laterally, the ignition element  20  can be inserted laterally, if necessary together with the porous material  24 . Here also, lateral closure can take place by a further housing part or a housing cover.  
         [0022]    It should be mentioned that it goes without saying that above all the construction described hereinabove of the housing arrangement  12  can be different. It is, of course, possible for the recess  18  to directly adjoin the opening  32  and for the opening  32  to form a portion of the recess  18 . It is also possible, as mentioned, to form the housing arrangement  12  of plural portions and, for example, to provide the recess  18  on one portion and the opening  32  on another portion.