Patent Publication Number: US-2017350285-A1

Title: Valve for Controlling a Gas Stream, Liquid Separator, Venting System and Internal Combustion Engine Having Such a Valve

Description:
The present invention relates to a valve for controlling a gas flow. Furthermore, it relates to a liquid separator, a ventilation system and also an internal combustion engine, which include such a valve. 
     In the crankcase of an internal combustion engine, blow-by gases occur which are guided normally, in particular for environmental reasons, into the intake duct of the internal combustion engine. For guiding the blow-by gases out of the crankcase into the intake duct, the pressure difference between the crankcase and the intake duct is used. 
     A ventilation system for a crankcase for transporting blow-by gases therefore normally has a ventilation pipe from the crankcase to the intake pipe. In the ventilation pipe, usually an oil separator/oil mist separator is disposed in addition in order to separate oil and oil mist, which are contained in the blow-by gases, from the blow-by gases. 
       FIGS. 1 and 2  show a combustion engine as an internal combustion engine in schematic cross-section. The internal combustion engine  1  has a crankcase  2 , a cylinder head  3  and also a cylinder head cover/valve cover  4 . Furthermore, the internal combustion engine  1  has an intake duct  10  with an air filter  11 , a charger device  13 , for example a turbocharger or a compressor, a throttle valve  14  and an intake pipe  12 , connecting these, with pipe sections  12   a ,  12   b  and  12   c . The intake pipe  12  leads from the air filter  11  via the charger device  13  and the throttle valve  14  to an intake manifold  5 . 
     In or on the valve cover  4 , a coarse oil separator  21  which serves for separation of oil or oil mist is disposed. The coarse oil separator  21  is flowed through by the blow-by gases. These are conducted, for this purpose, from the crankcase  2  either externally or via the cylinder head  3  and/or the valve cover  4  in the direction of the antechamber  20 . There they flow firstly through the coarse oil separator  21 . They enter via the coarse separator  21  into a pressure-side settling chamber  24  which, together with the coarse oil separator  21 , forms the antechamber  20 . 
       FIG. 1  shows this engine in coasting operation. In this state, just as in partial load operation, the blow-by gases flow from the settling chamber  24  via a suction-side postchamber  25 , in which a further oil separator  22  is disposed, and a ventilation pipe  16  to the intake pipe  12   c  between throttle valve  14  and intake manifold  5 . Ventilation via the suction-side chamber  25  and the ventilation pipe  16  serves for ventilation of the crankcase in partial load operation or coasting operation of the engine because, in partial load operation and in coasting operation, a negative pressure is present in the intake pipe  12   c  relative to the crankcase  2  so that the blow-by gases are guided through the oil separator  22 . For protection against uncontrolled pressure peaks, a pressure control valve  18  is disposed in the ventilation pipe  16 . 
     Whilst in partial load operation, a relatively large volume flow of blow-by gases must be guided from the crankcase to the intake duct, this volume flow is very low in coasting operation. Rather in the case of a closed throttle valve  14 , the pipe sections  15  and  16  are scoured via the chambers  26 ,  20  and  25 . In order to make this possible, a bypass valve  27  is provided between the chamber  26  and the chamber  20 , which valve opens with increased volume flow from the chamber  26  and hence increased pressure in the chamber  26  relative to the chamber  20 . The non-return valve  28  disposed parallel to the bypass valve  27  is closed in this state. 
     Parallel to the first-mentioned flow path via the oil separator  22  and the pressure-side chamber  25 , a further oil separator  23  and a suction-side chamber  26  are therefore disposed. Both suction-side chambers  25  and  26  are connected to the antechamber  20 . Starting from the suction-side chamber  26 , a ventilation pipe  15  leads to the section  12   a  of the intake pipe  12  between air filter  11  and charger device  13 . This pipe section is used in coasting operation, as already mentioned, for conducting fresh air in the direction of the chamber  20 . 
     In reverse flow direction, a ventilation valve  28  is disposed in front of the oil separator  23 , which ventilation valve opens in the case of sufficient low pressure in the intake pipe  12  in the region in front of the charger device  13 , i.e. in the pipe section  12   a . This is the case in full-load operation, as illustrated in  FIG. 2 . This means that, at very low pressure in the intake pipe  12   a  relative to the settling chamber  24 , this valve  28  opens as ventilation valve and enables a direct flow of blow-by gases from the crankcase  2  to the intake pipe  12   a  of the intake duct  10 . The bypass valve  27  is closed in this state. 
     In order therefore to ensure both reliable ventilation during coasting operation, as in  FIG. 1 , and reliable ventilation during full load as in  FIG. 2 , two different valves  27  and  28 , which are disposed parallel in the flow direction of the gases, are required. Installation of two different valves requires however constructional space, assembly complexity and costs. 
     Starting from this state of the art, it is now the object of the present invention to make available a valve arrangement which is optimised with respect to constructional space. At the same time, this valve arrangement is intended to fulfil the above-described functions reliably. Furthermore, it is the object of the present invention to make available a liquid separator, a ventilation system and an internal combustion engine which are optimised with respect to the required constructional space. 
     This object is achieved by the valve according to claim  1 , the liquid separator according to claim  20 , the ventilation system according to claim  21  and also the internal combustion engine according to claim  22 . Advantageous developments of the valve according to the invention are indicated in the associated dependent claims. 
     According to the invention, a valve for controlling a gas flow between the two sides of the valve is now made available. The valve has, like any conventional valve, a valve opening and a valve closure. The valve closure has a valve plate with which the valve opening can be closed. Furthermore, the valve closure is mounted on a valve bearing such that it is pretensioned in the direction for closure of the valve by means of the valve plate. As a result of this mounting of the valve closure which is pretensioned and resilient, the valve closure is closed in the case of absence of low pressure on the side behind the valve bearing of the valve viewed from the valve plate. 
     According to the invention, the valve plate is now provided with an opening element. The opening element now opens counter to the opening direction of the valve plate. 
     Whilst therefore the valve plate opens, in the case of overpressure, on a first side of the valve relative to the second side of the valve, and thus enables a gas flow through the valve opening, the opening element opens in the case of high pressure on the second side of the valve relative to the first side of the valve. Consequently, it becomes possible to provide the valve not only with a ventilation function but, simultaneously, also with a bypass function. 
     Whilst the valve plate is however mounted with pretension, the opening element can be used without or with pretension or without or with pretension counter to the closing direction of the opening element. 
     By means of the valve according to the invention, now two contrary valve functions are integrated in a single component. It is therefore advantageous with such a combination valve that it can fulfil two functions: firstly, passage through the valve in one direction with a definable differential pressure is possible and, at the same time, also opening in the other direction with a likewise definable differential pressure is possible. 
     For opening of the valve plate, differential pressures between 0 and 500 mbar are particularly suitable, advantageously between 0 and 100 mbar, respectively including or also excluding the boundary values. For opening of the opening element, differential pressures between 0 and 500 mbar are particularly suitable, advantageously between 0 and 200 mbar, respectively including or also excluding the boundary values. 
     By adjusting the differential pressures, it is therefore possible to produce a passage in one direction and a deliberate bypass in the other direction of the valve. It is not necessary now to provide separate valves for these two functions. Consequently, the valve according to the invention is more economical and easy to assemble. It is only necessary to pre-mount the assembly of the valve and to incorporate this then directly. The valve according to the invention is also readily scalable because of its low constructional space requirement. 
     With the valve according to the invention, it is possible in particular, even with only small available constructional spaces, for example with very limited cross-sections, to enable a double function of the opening in one direction and of the bypass in the other direction. Hence the valve also fulfils both requirements that, on the one hand, with a positive pressure, a bypass/high-pressure opening is made possible in one direction and, on the other hand, also a non-return/blocking function. 
     The opening element can advantageously be a through-opening in the valve plate which is closed by a flap. The flap thereby opens in a direction counter to the opening direction of the valve plate. The flap can thereby be mounted for example rotatably. The axis of rotation is then situated preferably at the side neighboring to the flap. 
     In another embodiment of the opening element, one or more slot-shaped openings are provided in the valve plate. In the case of high pressure on one side of the valve, the valve plate is deformed so that through-openings for the gases are formed along the slots. The slot-shaped through-openings can thereby be linear, meandering, in the form of circular sections or the like. Advantageously, one or more of such slot-shaped openings are provided. These can then extend at least partially parallel or concentrically relative to each other. 
     Advantageously, such slot-shaped openings are disposed essentially in edge regions of the valve plate, for example in regions which are removed from the surface centre of the valve plate by more than 50% of the radial extension. If the slot-shaped through-holes are now supported on one side by a bearing element, then the opening element which has these slot-shaped openings can open only in the other direction. Hence the opening element becomes a non-return valve which enables passage merely in one direction. 
     This bearing element can for example be configured in annular shape, in particular an entirely or extensively circular shape. Such a bearing element then is in particular configured in a circular shape if also the slot-shaped openings are configured correspondingly as circular sections. 
     The valve plate itself can have an outer contour which has an oval, elliptical, circular or other type of shape. 
     On the one hand, the opening of the opening element can be blocked entirely in one direction by the bearing element, on the other hand, by a suitable stopper, for example one or more webs, the degree of opening of the opening element can be delimited in the other direction. 
     This stopper is advantageously disposed, with respect to the gas flow direction in the case of an opened opening element, gas-flow-downwards or on the negative pressure side relative to the opening element. It forms a bearing for the opening element in the maximum opened state of the opening element. As a result, the opening element is mounted well and in a stable manner on the suction-side in the maximum opened state. 
     This bearing can have in particular a single web, a plurality of webs and in particular webs which intersect or converge to form a star or consist thereof. Advantageously, the region of the connection of the webs with each other is disposed such that the opening element is mounted in the centre/moment-free on this region in the maximum opened state. 
     As a result of this mounting of the opening element, described as advantageous, gas-flow-downwards/on the suction-side relative to the opening element, in particular deformation of the opening element in the maximum opened state is prevented or reduced and thus also the opening behaviour of the opening element or the throughflow cross-section which is uncovered at maximum by the opening element can be determined or established exactly. 
     The opening characteristic and the degree of opening of the opening element is established further by the number, shape and arrangement of the slot-shaped openings or of the flap. The degree of opening of the opening element is determined by the bearing element. In the case of laterally lifting flaps, delimitation to an opening angle≦85°, preferably ≦60°, is advantageous for simple reclosure. In the case of opening elements with slot-shaped openings, the stopper ensures that the opening element is deformed only within the elastic range thereof. 
     Similarly, by means of the spring characteristic of the resilient mounting of the valve closure on the valve bearing, the opening characteristic of the valve plate and hence of the valve opening is determined. 
     Advantageously, the valve plate consists of a metal sheet, in particular a steel sheet, particularly preferably of a tempered steel sheet or comprises this. In particular the opening element, which is element of the valve plate for its part, can also be manufactured from other materials. However, manufacture of the valve completely from metal is advantageous since a fully-metallically manufactured valve is subject to fewer restrictions with respect to the permissible temperature, i.e. is more temperature-resistant, and in addition has greater resistance relative to oils. 
     The valve in total, the bearing element and further elements of the valve can also consist of a plastic material, in particular of a thermoplastic plastic material, preferably of a polyamide, preferably polyamide 6.6, or comprise these materials even if the valve plate consists of a metallic material or comprises this. 
     The connection between the individual elements, for example the connection between the bearing element and an annular element bearing the stopper, with intermediate mounting of the edge region of the valve plate, can be produced in particular by means of a clip connection or by means of welding, ultrasonic welding, vibration welding or hot-gas welding. 
     Preferably, a metallic spiral spring or a pretentioned elastomeric column are suitable for the valve bearing. With both, a resilient elastic mounting of the valve plate with the required pretension can be achieved. 
     A liquid separator according to the invention now has a valve according to the invention and can be incorporated in a ventilation system according to the invention and in an internal combustion engine according to the invention. 
     Subsequently, a few examples of valves according to the invention are now given. The same or similar reference numbers in the various Figures thereby always denote the same or similar elements so that explanation thereof is in part not repeated. The subsequent examples respectively have a large number of different optional features of the valve according to the invention, alone or also in combination with each other. These features according to the invention can however, also in a different combination or even per se separately, develop the valve according to the invention. 
    
    
     
       There are shown 
         FIGS. 1 and 2  an internal combustion engine according to the state of the art in coasting operation and full-load operation; 
         FIG. 3  an internal combustion engine according to the invention; 
         FIG. 4  an embodiment of a valve according to the invention in side plan view; 
         FIG. 5  to  FIG. 9  plan views or sectional views of the valve according to the invention; 
         FIGS. 10 a  to 10 c    different embodiments of a valve plate of a valve according to the invention; 
         FIG. 11  a plan view on a valve according to the invention; 
         FIG. 12  a further plan view on a section of a valve according to the invention; 
         FIG. 13  a view from below of a section of a valve according to the invention; 
         FIG. 14  a side plan view on a valve according to the invention; 
         FIG. 15  a top view on a section of a valve according to the invention; 
         FIG. 16  a side plan view on a valve according to the invention; 
         FIG. 17  in three partial  FIGS. 17A, 17B and 17C , a further valve according to the invention. 
     
    
    
       FIG. 3  shows an internal combustion engine  1  according to the invention. This internal combustion engine is constructed in the same way as that in  FIGS. 1 and 2 . In contrast to the internal combustion engine in  FIGS. 1 and 2 , this however does not have two valves  27  and  28  but rather one valve  29  according to the invention which extends over the separation wall  30 . The separation wall  30  is thereby itself part of the valve  29  insofar as it forms the valve opening  37  of the valve  29 . 
     The valve  29  is now configured such that, during coasting operation of the engine, it opens in the direction of the chamber  24  and consequently makes possible a gas flow via the pipe  15 , the chamber  26 , the separator  23  and the valve  29  towards the chamber  24  and then, from there together with the blow-by gases, via the oil separator  22  and the chamber  25  and also the pipe  16  into the intake pipe  12   c.    
     In the case of full load, a high pressure is present behind the throttle valve  14  in the region  12   c  of the intake pipe  12 . Therefore, the gas flow, in particular fresh air, now flows via the pipe  16  with the pressure control valve  18 , the chamber  25 , the separator  22  towards the chamber  20  and, from there together with the blow-by gases, via the valve  29 , the separator  23 , the chamber  26  and the pipe  15  into the intake pipe  12  in section  12   a . The valve  29  is therefore opened in the direction of the chamber  26 . 
       FIG. 4  shows a side plan view on a valve  29  according to the invention. This valve  29  has a valve opening  37  which is disposed in a portion of the separation wall  30 . This portion of the separation wall  30  can be regarded as belonging to the valve. It is however also possible to provide the valve opening in a separate component which can be inserted in an opening of the separation wall  30 . The valve opening  37  is closed by a valve closure which is formed from a first annular element  41 , a valve plate  43  and a second annular element  42 . Both annular elements  41  and  42  enclose, between each other, the circumferential edge of the valve plate  43  and therefore secure this. The valve closure consisting of these three elements is now mounted resiliently on a spring  36  and a valve bearing  33 . With sufficient pressure on the valve plate  43  (from the left in the drawing), the valve closure is therefore pressed counter to the spring force in the direction of the bearing  33  and hence uncovers the valve opening  37 . 
     The valve bearing  33  is secured on the separation wall  30  via retaining elements  31 . Should an individual element be provided in order to form the valve opening, securing on this element is then effected via the retaining elements  31 . For simpler assembly, the retaining elements  31  have catch lugs  32 . Corresponding to these catch lugs  32 , the valve bearing  33 , which can be configured for example as base plate, has projections  34  with catch openings  35 . As a result, the valve bearing  33  can be mounted easily on the retaining elements  31 . The separation wall  30  and/or the retaining elements  31  can in general be for example part of a housing or of a wall, for example of a housing or wall of a valve cover, an oil separator module, an oil sump, a front cover or the like. 
     According to the invention, the valve plate now has an opening element  50 . This opening element  50  includes slots  51  which enable opening. These slots are covered on the rear-side by the ring element  42 , not detectable in  FIG. 4 . High pressure on sides of the second annular element  42  opposite the side of the annular element  41  consequently leads to deflection of the central part of the valve plate  43  so that the slots  51  are opened and annular gaps are uncovered. Consequently, a bypass function from the side of the second annular element  42  to the side of the first annular element  41  is produced. This bypass function makes it possible for gases to be able to flow through the valve counter to the actual opening direction of the valve. 
     For opening of the valve by lifting of the valve closure from the valve opening  37  counter to the pretension of the spring  36 , in particular differential pressures of 0 to 500 mbar, preferably 0 to 100 mbar, are suitable. For opening of the opening element by widening the slots  51 , pressure differences between pressure and suction-side of 0 to 500 mbar, preferably 0 to 200 mbar, are suitable. These values are basically preferred values for every valve according to the invention and apply excluding or also including the respective range limits. 
     The first ring  41  has furthermore hoops or webs  44  disposed in a cross-shape. These webs extend firstly vertically and then horizontally over the valve plate  43  and—in the rest position thereof—are at a spacing from the valve plate  43 . If now the valve plate  43  is deformed by high pressure on sides of the second annular element  42  and the slots  41  are thereby widened, then the webs  44 , which are disposed, in the opened state of the valve plate  43 , gas-flow-downwards or on the suction-side relative to the throughflow direction, serve as stoppers for opening the valve plate, they ensure that the valve plate is deformed only within the elastic range. 
       FIG. 5  shows a side plan view on the same valve as in  FIG. 4 . In this view, it can be readily detected that the valve plate  40  is formed by the first annular element  41  and the second annular element  42  and also by the valve plate  43  which is mounted between these two annular elements and by these two annular elements. 
       FIG. 5  thereby shows a state in which, on the one hand, the valve opening is closed and, on the other hand, also the valve plate is not deflected. 
       FIG. 6  shows a state of the same valve as in  FIG. 4  and  FIG. 5 . In  FIG. 6 , the valve plate  43  is now however deflected such that it abuts against the stopper webs  44 . The slots  51  uncover the flow path. As a result, a gas passage from the right-hand side in the drawing towards the left-hand side in the drawing is now possible. The valve opening  37  itself is furthermore closed as such by the valve closure  40 , i.e. the connection of both annular elements  41 ,  42  and valve plate  43  mounted therebetween. 
       FIG. 7  shows the same valve as in  FIGS. 4 to 6 . Now however, the valve closure is displaced by high pressure on sides of the first annular element  41  counter to the pretension force of the spring  36  in the direction of the valve bearing  33 . Consequently, the valve opening is now uncovered annularly so that gases from the left-hand side in the drawing can flow towards the right-hand side in the drawing through the valve opening. 
       FIG. 8  shows a section through the valve according to  FIGS. 4 to 7 . It can be readily detected hereby how the valve plate  43  is clamped and mounted at its edges between the first annular element  41  and the second annular element  42 .  FIG. 8  thereby shows the valve in a state in which both the valve opening  37  is closed and the opening elements in the valve plate  43  are not widened. 
     In  FIG. 8 , that region of the valve plate  43 , which is mounted clamped between the first annular element  41  and the second annular element  42 , is provided with the reference number  43 ′. Furthermore, that region of the second annular element  42 , on which the valve plate  43  is supported in  FIG. 8 , is provided with the reference number  42 ′. In the region of this support region  42 ′, the slot-shaped openings  51  are disposed in the valve plate  43 , whilst no slot-shaped openings  51  are provided outside this region. As a result, in the case of high pressure on sides of the first annular element  41  relative to the second annular element  42 , the valve plate cannot be widened. The valve plate  43  with the opening elements thereof therefore forms a non-return valve. 
       FIG. 9  shows the same valve as in  FIG. 8 , now however in a state in which a high pressure prevails on sides of the second annular element  42  relative to the side of the first annular element  41 . The valve plate  43  is now widened in the direction of the stopper webs  44  and abuts against these. Consequently, the slots are widened in the edge region of the valve plate  43  and uncover annular gaps for the throughflow by gases. 
       FIGS. 10 a  to 10 c    show different variants of opening elements. 
     In  FIG. 10 a   , the slot-shaped openings are present in a plurality, namely three here, which are disposed concentrically in the shape of circular sections. In  FIG. 10 b   , a single slot which extends helically over in total 1¾ circles is provided. In  FIG. 10 c   , in total four slot-shaped openings  41  which are disposed offset relative to each other are provided. 
     It is common to all these opening elements that they are disposed in the outer region of the valve plate  43  so that the central region of the valve plate  43  remains closed and can lift as such out of the plane of the valve plate with suitable pressure conditions. The outer region of the valve plate is thereby blocked in the mounted state such that an opening counter to the opening direction from the first to the second side of the valve is not possible.  FIG. 11  shows a plan view on the valve for example according to  FIG. 9  and  FIG. 10 a   . It can be detected here that the central region of the valve plate  43  is not pierced. The annular slots  51  are merely provided in those regions at the edge of the valve plate  43  in which they are covered and supported by the second annular element  42  below the drawing plane. 
       FIG. 12  now shows a further embodiment of an opening element  50 .  FIG. 12  thereby shows a plan view on the valve as in  FIG. 11 . Now however, the stopper webs  44  are disposed in a T-shape. The opening element  50  is disposed in the drawing plane below the stopper webs  44 . This opening element  50  has a flap/closure element  52 . This flap  52  is mounted rotatably on a bearing  53 . The stopper webs  44  have the effect here that the flap  52  can be opened by at most 45°. 
       FIG. 13  shows a view from below of this rotatably mounted opening element  50 . The flap  52  which is mounted in the rotary bearing  53  now has a rubber support  54  on the lower side. This rubber support  54  is configured such that it completely covers an opening in the valve plate. Instead now therefore of deforming the entire valve plate in order to widen slot-shaped opening elements, as in the previous embodiments, now opening of the flap  52  about the rotary hearing  53  thereof is effected with suitable pressure conditions. 
       FIG. 14  shows a side plan view on the entire valve which is basically configured just like the valve in  FIG. 4 . Merely the opening element  50  of the valve plate is now configured as flap  52 .  FIG. 14  thereby shows a state in which the flap  52  is opened and abuts against the stopper webs  44 . Consequently, it delimits the opening angle of the flap  52 . 
       FIG. 15  now shows a further valve in plan view. Merely the section of the opening element  50 , more precisely the valve flap  52 , is thereby illustrated. In contrast to the flap  52 , in  FIG. 12 , only a single stopper web  44  is provided, which web is configured as a freely projecting bar and is anchored in one piece, with and in the annular element  41 . It is supported at its left side on the first annular element  41 . Its right-hand end is free and serves as limit stop for the flap  50  during opening thereof. As a result, opening of the flap by at most 60° is made possible so that also closing the flap again does not present any difficulty. 
       FIG. 16  shows a plan view on a valve which has a flap as in  FIG. 15 . The valve is thereby illustrated in a state in which high pressure prevails on sides of the second annular element, compared with the first annular element, so that the flap  50  is opened and abuts on the projecting stopper web  44 . 
       FIG. 17  shows, in three partial Figures, a further embodiment of a valve  29  according to the invention. Here the valve plate  43  is pretensioned counter to its closing direction.  FIG. 17A  illustrates a cross-section through the closed valve plate  43  together with the second annular element  42 . The annular element  42  here has a gradation/gradated region  45  via which the valve plate  43  is pretensioned. The gradated regions  45  form a circumferential edge for a through-opening  46  within and through the second annular element  42 . Those regions  43 ″ of the valve plate  43 , which have slot-shaped openings  51 , extend oblique to the plane of the valve plate  43  within this opening. 
       FIG. 17B  shows the incorporation situation of this—likewise closed here—valve plate  43  in a valve analogously to  FIG. 8 . As in  FIG. 17A , the gradation 43″ can be detected, via which the slotted regions of the valve plate  43  are pretensioned in the direction of the annular element  41  via the other plane of the annular element  42 . 
       FIG. 17C  shows the valve of  FIG. 17B  now in the opened state, the valve plate, by applying high pressure or gas volume flow from the direction of the spring element  36 , being lifted from the gradated region  45  and the slot-shaped openings  51  being widened and opened. By means of the pretension of the valve plate over the gradated region  45 , displacement of the opening point of the valve at for example 10 mbar as far as higher pressure differences can be achieved. When applying a high pressure from the side of the webs  44 , the valve plate is however not deflected so far in the direction of the spring  36  that the slot-shaped openings  51  would uncover a passage for gases through the slot-shaped openings  51  and through the opening  46  between the gradated regions  45 .