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.
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.
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 12a 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 12a. This is the case in full-load operation, as illustrated in
In order therefore to ensure both reliable ventilation during coasting operation, as in
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
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 12c.
In the case of full load, a high pressure is present behind the throttle valve 14 in the region 12c 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 12a. The valve 29 is therefore opened in the direction of the chamber 26.
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
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.
In
In
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.
Number | Date | Country | Kind |
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20 2014 106 257.2 | Dec 2014 | DE | national |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2015/079899 | 12/15/2015 | WO | 00 |