Abstract:
With metered admixing of volatized fuel in an intake manifold of an internal combustion engine with a supercharger, the problem exists that depending on the respective operating state, different pressures prevail in the intake manifold. This problem is resolved in known devices, in that return valves are subsequently added and structurally separated from the tank aeration valve in the flow direction. The present invention proposes that the return valves ( 39, 40 ) are structurally integrated in a tank aeration valve ( 5 ), in order to reduce the assembly expense and the spatial requirements.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    The present application relates to a device for the metered admixing of volatized fuel in an intake manifold of an internal combustion engine.  
           [0002]    From DE 40 23 044 A1, a tank aeration valve is known, in which for the use in so-called supercharged aero engines or blower-fed engines, a return valve is integrated on the outlet side. Since in turbo operation, the necessary negative pressure does not prevail in an inlet manifold, in order to produce a flow from an activated charcoal filter in the direction of the intake manifold for a regeneration of an activated charcoal filter, rather, a similarly high excess pressure, a return or return valve is placed in the tank aeration valve on the outlet side, which closes in turbo operation and thereby prevents a back flow from the intake manifold in the direction of the activated charcoal filter. A regeneration of the activated charcoal filter in turbo operation is therefore not possible. This is particularly disadvantageous, since with today&#39;s supercharged aero engines, the turbo operation makes up more than 80% of the operating time.  
           [0003]    From DE 43 11 316 C1, a device is known that comprises a tank aeration valve and a separate valve housing with two return valves, which remedies these disadvantages. The separate valve housing has an inlet channel and two outlet channels, whereby one of the outlet channels is connected with the suction side of the supercharger and the other outlet channel is connected with the pressure side of the super charge downstream of a throttle valve. In each outlet channel, a return valve is provided, so that one of the outlet channels can flow only in the direction of the suction side of the supercharger and the other outlet channel can only flow in the direction of the pressure side of the supercharger. In turbo operation, an over pressure prevails down stream of the supercharger in the intake manifold, so that the return valve connected with the pressure side closes, while the return valve connected with the suction side of the supercharger opens and the volatized fuel can be supplied from a fuel tank to the internal combustion engine. In this manner, the activated charcoal filter can be regenerated in turbo operation. This solution of the structural separation from the magnetic valve and the valve housing with two return valves still has the disadvantage that the manufacturing costs and the assembly costs are similarly high and in addition, additional lines and much space is required.  
         SUMMARY OF THE INVENTION  
         [0004]    The device of the present invention, in contrast, has the advantage that in a simple manner, a simplification is cost-effectively achieved, in which the tank aeration valve and the two return valves are integrated in or with a housing and thereby, connection lines from the tank aeration valve to the separate valve housings with the return valves can be eliminated, which substantially simplifies assembly and offers a significant cost savings as a result.  
           [0005]    It is advantageous if the first housing part is cup-shaped, in order to enable a spatially good arrangement of the valve body and an actor.  
           [0006]    In addition, it is advantageous if the second housing part is cover-shaped on space-saving grounds.  
           [0007]    It is particularly advantageous if a return valve is arranged on each of the two outlet connections on the side facing the tank aeration valve, since this substantially simplify the assembly of the tank aeration valve.  
           [0008]    It is also advantageous if one of the outlet connections is pluggable for the insertion of the intake manifold in a cylindrical opening, since in this manner, the assembly of the tank aeration valve on the internal combustion engine is greatly simplified and, for example, a hose connection is dispensable.  
           [0009]    In addition, it is advantageous to provide a flow element, for example, a laval nozzle, in the two outlet channels.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]    One embodiment of the invention is shown in the drawings and is described in more detail in the subsequent description.  
         [0011]    [0011]FIG. 1 shows a device for tank aeration for an internal combustion engine with a supercharger; and  
         [0012]    [0012]FIG. 2 shows the device of the present invention in a longitudinal section.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0013]    [0013]FIG. 1 shows a device for ventilation of a fuel tank  1 . A ventilation channel  2  of the fuel tank I is connected to a storage unit  3  filed with activated charcoal, for example, which temporarily absorbs the volatized fuel from the fuel tank  1 . Before the absorption capacity of the storage unit  3  is depleted, in a regeneration phase, a control valve  62  of a tank aeration valve  5  located in a discharge line  6  is opened, so that by a negative or low pressure in an intake manifold  7 , air from the surrounding environment is sucked in via a ventilation opening  4  provided on the storage unit  3  and flows through the storage unit  3 . The activated charcoal supplied thereby the absorbed fuel to the air. The fuel-air mixture formed in this manner is also designated as a tank aeration mixture or regenerating gas. The regenerating gas arrives in the regeneration phase via the tank aeration valve  5  in the intake manifold  7  of an internal combustion engine  8  with a supercharger  9 . In this manner, the regenerating gas, depending on the operation state of the internal combustion engine  9 , is either mixed with the suction air in the intake manifold  7  upon supercharger operation via a first discharge line section  6 . 1  on a suction side  10  of the charger  9  or with the manner of operation, with a still charger  9 , via a second discharge line section  6 . 2  on a pressure side  11  of the charger downstream of a throttle valve  57 . A control apparatus  13  controls the volume of the regenerating gas to be mixed over an opening time of the control valve  62 . In this manner, the control valve  62  can be cyclically controlled by alternating opening and closing.  
         [0014]    After the end of the regeneration phase, the absorption capacity of the storage unit  3  is restored and the storage unit  3  can again absorb fuel. In the tank aeration valve  5 , a first return valve  39  and a second return valve  40  are arranged near the control valve  62 . The first return valve  39  closes upon charger operation and prevents therewith a back flow of the intake or suction air from the intake manifold  7  in the storage unit  3 . The second return valve  40  opens upon charger operation and makes possible in this manner that also with a charger operation, a regeneration phase can take place. Outside of the charger operation, the first return valve  39  is opened and the second return valve  40  is closed.  
         [0015]    [0015]FIG. 2 shows the tank aeration valve  5  in longitudinal section. The tank aeration valve  5  comprises, for example, a two-part housing  12  with a first housing part  14 , which, for example, is cup-shaped, and with a second housing part  15 , which, for example, is cover-shaped. The first housing part  14  has an inlet connection  16  for connection via the discharge line  6  to the storage unit  3  that is filled with activate charcoal, for example, for the volatized fuel. The inlet connection  16  has an opening  17  in an inner chamber  19  in the region of a floor  20  of the cup-shaped first housing part  14 . The first housing part  14  has, for example, on its periphery a plug  21  that is connected as one-piece with the first housing part  14 , which has a connection element  22  for connecting to an outside plug contact.  
         [0016]    In the inner chamber  19  of the cup-shaped first housing part  14 , the control valve  62 , which is actuated by an actor, with a valve member  29  and a sealing seat  49  is arranged. The actor, for example, is an electromagnet  32 . The electro-magnet  23 , for example, has a cup-shaped magnet housing  25  with a cylindrical magnet core  26  that penetrates the cup floor and is coaxial to a valve axis  18  and which has a cylindrical field coil  27 , which sits on a coil support  24 , which surrounds the magnet core  26  in the magnet housing  25 . On side of the magnet core  26  facing the second housing part  15 , a valve member  29  that is adjustable counter to the return for of a return spring  28 . The valve member  29  is activated by the electromagnets  23  and is an armature plate, which comes into contact with the sealing seat  49  arranged directly or indirectly on the second housing part  15 . On the armature plate  29  forming a valve member, further, a sealing and damping member  30  is arranged. The sealing and damping member  30  is arranged on the armature plate  29  and on the magnet core  26  and connects these elements to one another as an elastic element.  
         [0017]    The second housing part  15 , for example, is centrally arranged in a recess  38  of the first housing part  14  and connected thereto. As viewed in the flow direction, a channel  31  formed in the second housing part  15  connects to the armature plate  29  downstream of the sealing seat  49 . The channel  31  branches off in a first channel  32  and a second channel  33 , whereby the first channel  32 , for example, ends in a first recess  34  and the second channel  33  ends in a second recess  35  of the second housing part  15 . In the first recess  34 , a first outlet connection  36  with a first outlet channel  49  is partially arranged and in the second recess  35 , a second outlet connection  37  with a second outlet channel  60  is partially arranged. The first outlet channel  59  is connected with the first channel  32 , and the second outlet channel  60  is connected to the second channel  33 . Both outlet connections  36 ,  37  are welded or adhered or screwed, for example, to the second housing part  15 . In the first outlet channel  59 , a first return valve  39  is arranged on the side facing the second housing part  15 . The first return valve comprises a first valve body  41 , a first valve seat  42 , and a first return spring  43 . In the second outlet channel  60 , a second return valve  40  is arranged, the second return valve  40  comprising a second valve body  53 , a second valve seat  54 , and a second return spring  55 . In this manner, the valve seats  42  and  54  are formed on the second housing part  15 . The return valves  39  and  40  both close against a flow direction by a control valve  62  to the outlet connections  36 ,  37 .  
         [0018]    In addition, the first outlet channel  59  has a flow element  48 , for example, a laval nozzle. The flow element  48 , however, is not limited to a laval nozzle and also can be embodied as a screen or throttle. The flow element  48  is formed such that the surface of its narrowest flow cross section is smaller than the surface of the opening cross section of the sealing seat  49 . Also, the flow element  48 , for example, a laval nozzle, can be arranged in the second outlet channel.  
         [0019]    On the outer circumference of the first outlet connection  36 , a cylindrical section  45  is arranged, in which a groove  51  for receiving a sealing ring  52  is located. For the assembly on the internal combustion engine  8 , the first inlet connection  36  of the tank aeration valve  5  needs only to be inserted into an opening of the intake manifold  7  downstream of the charger  9 . A fiber  46  facilitates this assembly step.  
         [0020]    [0020]FIG. 1 shows that the tank aeration valve  5  is connected via the discharge line  6 . 2  with the intake manifold  7  downstream of the charger  9 . The discharge line  6 . 2  can be a line, for example, a hose, which connects the first outlet connection  36  with the intake manifold  7  downstream of the throttle valve  57 . If the tank aeration valve  5  is inserted instead with the first outlet connection  36  into an opening of the intake manifold  7 , than the first outlet channel  59  is also simultaneously the discharge line  6 . 2   
         [0021]    The second outlet connection  37  is connected with the intake manifold  7  by means of a discharge line  6 . 1  downstream of the charger  9 . The discharge line  6 . 1  can be a hose connection, for example.  
         [0022]    The first return valve  39  of the first outlet connection  36  opens against the force of the first return spring  43  at a negative pressure predetermined by the force of the first return spring  43  in the intake manifold  7  downstream of the throttle valve  57 . The negative pressure in the intake manifold  7  downstream of the throttle valve  57  is sufficiently large to open the first return valve  39  in the manner of operation of the internal combustion engine  8 , in which the charge  9  rests. Since, with an opened first return valve  39 , the pressure in the second channel  33  is smaller then downstream of the second return valve  40  in the second outlet channel  60 , the second return valve  40  closes approximately simultaneously with the opening of the first return valve  39 .  
         [0023]    In operation of the supercharger, an overpressure prevails in the intake manifold  7  on the pressure side  11  of the supercharger  9  downstream of the throttle valve  57 , so that the first return valve  39  closes. The negative pressure in the intake manifold  7  on the suction side  10  of the supercharger  9  opens approximately simultaneously with the second return valve  40 .  
         [0024]    The housing  12  and the outlet connections  36  and  37  are made of plastic, for example.  
         [0025]    It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the types described above.  
         [0026]    While the invention has been illustrated and described herein as a device for metered admixing of volatized fuel in an intake manifold of an internal combustion engine, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.  
         [0027]    Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention.