Fluid Control Device

A fluid control device, including: a housing, including: a first port having a first main axis; and at least one second port, each having a respective second main axis; wherein the first main axis and the second main axis are aligned off-axis to one another; wherein a control means is arranged within the housing, the control means configured to control a fluid flow between the first port and the at least one second port; wherein the control means includes a valve body arranged within the housing, the valve body rotatable around the first main axis of the first port, the valve body having a fluid path for guiding the fluid through the valve body.

TECHNICAL FIELD

The invention relates to a fluid control device, in particular to an air intake shifter for air ducts of internal combustion engines of vehicles, more particularly, it relates to a charge air duct for a turbocharged engine, such as a one-stage turbocharged engine.

BACKGROUND OF THE INVENTION

Charge air within the meaning of the invention shall be understood as compressed air, compressed by an exhaust turbocharger or any other kind of charger or compressor.

For turbocharged engines, geometry (diameter and length) of charge air ducts (also called charge air delivery ducts) is tuned to take benefits from pressure waves for improving the air filling into the engine cylinders and thus increase the output torque.

However, optimal geometry of charge air ducts is dependent on engine speed. At high engine speeds, for instance above around 1500 rpm (revolutions per minute), and high load, the turbocharger compresses the supplied air in an effective manner. Under these engine operating conditions, a charge air duct of small length and larger diameter is suitable in order to reduce pressure loss and increase the engine power.

At low engine speeds (around 1250 rpm for instance) and part load operation, the turbocharger compressor is not very effective (the charging effect of the turbocharger is poor and limits the engine output torque). Under these engine operating conditions, a longer duct having a reduced inlet diameter is appropriate in order to increase the engine feeding (i.e. the mass of gas introduced into the combustion chamber) and thus the volumetric efficiency.

Conventional charge air ducts have a fixed length, which is a tradeoff between engine torque and power. With a charge air duct of fixed length, the engine performance is optimized at a specific engine speed, but not on a large operating range. Also, because of harsh environmental requirements in the automotive sector, aiming to reduce fuel consumption and CO2emissions, there is a great demand for increase in the engine output torque of a turbocharged engine in the low engine speed range.

Therefore, it is desirable for optimal engine control to have the possibility to change the air inlet of a combustion engine between different air duct branches according to engine speed and load condition.

DE10314629A1 discloses an induction system for an internal combustion engine which has a rotary valve directing the incoming fuel/air mixture either through a short wide induction pipe or a narrow long induction pipe. The fuel/air mixture passes through an inlet channel into a chamber with several short wide tubes and long narrow tubes leading to the individual cylinders. A rotary valve body forms part of a valve assembly and is accommodated in a cylindrical housing. The housing has a wide opening for each cylinder and a narrow opening. The valve body is rotated to line up wide or narrow passages with the entry port for each cylinder.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a fluid control device, in particular an air intake shifter for air ducts, which is reliable, compact, cheap to manufacture and easy to assemble, and which can easily be adapted to different engine operating modes.

This object is achieved by a fluid control device, including a housing with one first port and with at least one second port, wherein a control means is arranged within the housing to control a fluid flow between the first port and the at least one second port.

According to a first aspect of the invention, a fluid control device, in particular an air intake shifter, is proposed, which comprises a housing with one first port having a first main axis and with at least one second port having at least one second main axis. Advantageously, the first main axis is perpendicular to the cross section of the first port and the one second main axis is perpendicular to the cross section of the at least one second port.

The first main axis and the at least one second main axis are aligned off-axis to one another. A control means is arranged within the housing to control a fluid flow between the first port and the at least one second port. The control means comprises a valve body being rotatable around the first main axis of the first port, whereas the valve body comprises a fluid path for guiding the fluid through the valve body.

The control means are enabling the fluid flow between the first port and the second port by connecting the first and the second port via the fluid path or between the first port and a third port by connecting the first and the third port via the fluid path. The flow direction of the fluid can be from the second port or third port to the first port or alternatively from the first port to the second or the third port.

The proposed inventive fluid control device deals with a product which is able to shift a fluid flow path from one first port to at least a second port while keeping the pressure losses of the fluid during passage through the fluid control device low. This exhibits a significant advantage over current fluid control devices according to state of the art using flaps or valves with axles in the main path of the fluid flow which create high level of fluid pressure drops even at open positions of the fluid path, where even at open positions the axles and the flaps are remaining in the middle or near the middle of the fluid path. The inventive fluid control device on the contrary is able to withstand high fluid pressures and high levels of fluid pulsation without significant losses of fluid pressure. Further, the fluid control device is characterized by a high level of fluid tightness at the end positions of a valve body of the control means.

The inventive fluid control device may be used as an air intake shifter for air ducts of internal combustion engines of vehicles if the ports of the fluid control device are connected to two inlets and one outlet of the air duct, for instance. Thus it may be part of an active charge air duct. Alternatively, the fluid control device may be used as a shutter, if the ports of the fluid control device are connected to one inlet and one outlet of the air duct.

The valve body of the control means of the inventive fluid control device is able to rotate around the first main axis of the first port, thus an axle of the valve body does not cause any significant pressure drop of the fluid flow as it is directed in the fluid flow direction. The fluid path, which may be manufactured by drilling the valve body in order to provide a unique fluid path inside the valve body, is always connected and open to the first port, whereas the other side of the fluid path is either connected and open to a second port or by rotating the valve body to a third port. Alternatively the fluid path may be partly open to both second and third ports, thus providing a partly open connection from the second and the third port to the first port and mixing the fluid flows from both second and third port when feeding to the first port.

In a further alternative, if the fluid control device does not exhibit a third port, it can be used to open or close the second port in order to work as a shutter for the second port.

Favorably, the valve body may have at least one outer surface section having a spherical shape. If the valve body is constructed as a sphere or at least part of the valve body is realized as a part of a sphere, where the valve body may be of generally spherical shape, but with edges and recesses, it is quite convenient and efficient to rotate it around the main axis of the first port. The moment of inertia can thus be kept quite low thus enabling to rotate the valve body at a high speed and with a low activating torque.

Therefore, advantageously at least a section of an inner surface of the housing may have a spherical shape corresponding to the outer surface section of the valve body. Thus sealing of the valve body against the housing can be achieved very efficiently and reliably with low friction values of the valve body to the inner surface of the housing.

Advantageously a seal groove for a gasket is formed in the valve body to receive the gaskets. It extends along the surface into the valve body. With an integration of the groove in the valve body the tolerances between valve body with gasket and the valve housing can be kept small. The package needed for the sealing area is optimized by forming the groove within the valve body. The sealing area on side of the housing can be shaped in a flat manner. The manufacturing of the housing, advantageously as an injection molded plastic part is easy and possible without any complex tool. Forming a groove for a gasket in a convex curved valve body is less complex than a forming a groove on a concave curved inner surface of a housing. In an advantageous embodiment the inner surface of the housing does not have any gasket groove shaped features in the sealing area.

According to an advantageous embodiment, the housing may comprise at least a first shell and a second shell. This enables convenient assembly conditions, because thus the valve body may be inserted into one of the shells, then the other shell may be put on top of the valve body and the first shell and finally both shells may be closed and tightened by welding or by screws or the like. This also exhibits a very modular construction of the fluid control device, because by changing one of the two shells, where the first shell, for instance, carries the first port and the second shell carries the second and the third port, an alternative type of fluid control device may be assembled, exhibiting different ports concerning mechanical interfaces or a different number of ports or changing the fluid control device from an air intake shifter to a shutter or vice versa.

Favorably, in a first position of a valve body of the control means a fluid connection may be established between the first port and the at least one second port and in a second position of a valve body of the control means the fluid connection between the first port and the at least one second port may be closed. Thus a switching or shifting or alternatively a shutter behavior of the fluid control device may be realized where the fluid path is open from the first port to the second port in one position, whereas the fluid path from the first port to the second port is closed in a second position. If the housing carries a third port, in the second position the fluid path may be open from the first port to the third port. If the housing does not carry a third port then the fluid control device is working as a shutter and closes the fluid path simply in the second position.

In an advantageous embodiment, the valve body may be arranged to provide a fluid connection alternatively between the first port and the second port or between the first port and at least a third port. This is the realization of an air intake shifter, for instance, where the air inlet to a combustion engine is shifted between different air ducts, e.g., from a charge air duct to a pulsating air duct.

Due to a further favorable embodiment, in at least one position of a valve body of the control means the second and third ports may be at least partially open to the first port.

Thus a mixing function between two input flows from the second and the third port guided to the first port may be realized for optimizing a certain combustion function of an engine, for instance.

Due to an advantageous embodiment, the valve body may be two-dimensionally sealed by gaskets to the first port and the at least one second port. The fluid tightness may be ensured by a sealing area at the interface between an opening of the fluid path in the valve body and the first or second port provided in the housing of the fluid control device. The sealing area may be kept two-dimensional to ensure the reliability of the sealing function. This can be achieved by a gasket around the two-dimensional plane of the opening of the fluid path in the valve body in cylinder shape, sealed to the spherical inner surface of the housing around the first or second port.

Advantageously a groove for a gasket around a two-dimensional plane formed by the valve body results in a tight sealing.

Advantageously, the valve body may be rotatable by action of a driving mechanism located outside the housing. A rotating axle of the valve body may be fed through the housing in order to be coupled to an actuator as a driving mechanism of the control means of the fluid control device. Such an actuator can be a vacuum actuator, e.g., which is a very common type of actuator in combination with combustion engines, particularly in vehicles. Alternatively an electric actuator can be used for rotating the valve body.

In an advantageous embodiment, the housing and/or the valve body may be made of plastics materials. Plastics materials are not only very convenient for manufacturing different shapes of devices, but are also a cheap and flexible way of producing in a high output. Further it is advantageous to use, for instance, a Teflon segment for the sealing area of the valve body and as a counterpart other plastics materials for the corresponding inner surface of the housing. Thus a very efficient and reliable sealing function is achievable in an economic way. A segment for the sealing can consist of a suitable material different to Teflon as well.

According to another aspect of the invention, an air intake shifter is proposed, including a fluid control device, having a first port, a second port and a third port, wherein the first port is alternatively coupleable to the second port or the third port by a control means, which is rotatable about a main axis of the first port, which main axis is perpendicular to the cross section of the first port. A switching or shifting behavior of the fluid control device may be realized where the fluid path is open from the first port to the second port in one position, whereas the fluid path from the first port to the second port is closed in a second position. If the housing carries a third port, in the second position the fluid path may be open from the first port to the third port. This is the realization of an air intake shifter, for instance, where the air inlet to a combustion engine is shifted between different air ducts, from a charge air duct to a pulsating air duct, for instance.

Advantageously, the first port may be an air outlet and the second port may be an air inlet for charge air and the third port may be an air inlet for pulsating air. The charge air may be generated by a turbocharger, whereas the pulsating air may be generated by a resonance device. Thus it is possible to get more air into a combustion engine, to achieve a higher level of pulsation and to increase an engine efficiency. Different load conditions of combustion engines may be optimized by an optimized supply of air for the combustion process. The fluid control device can thus be used for a shifting of the air inlet according to the load conditions of the combustion engine. Shifting may be achieved dependent on specific engine speeds and engine load, or other engine parameters like temperature, pressure, mass flow or others.

According to another aspect of the invention, a fluid shutter is proposed, including a fluid control device, having a first port and a second port, wherein a fluid connection between the first port and the second port is switchable by a control means, which is rotatable about a main axis of the first port, which main axis is perpendicular to the cross section of the first port. A shutter behavior of the fluid control device may be realized where the fluid path is open from the first port to the second port in one position of a valve body, whereas the fluid path from the first port to the second port is closed in a second position. If the housing does not carry a third port then the fluid control device is working as a shutter and closes the fluid path simply in the second position of the valve body.

DETAILED DESCRIPTION OF THE DRAWINGS

In the drawings, like elements are referred to with equal reference numerals. The drawings are merely schematic representations, not intended to portray specific parameters of the invention. Moreover, the drawings are intended to depict only typical embodiments of the invention and therefore should not be considered as limiting the scope of the invention.

FIG. 1depicts in a cross cut view a first example embodiment of a fluid control device100according to the invention in a first position of a valve body24of a control means22, where a fluid path28is open from a first port20to a second port16. The fluid control device100inFIG. 1, for instance an air intake shifter, is including a housing10with one first port20having a first main axis27perpendicular to the cross section of the first port20and with one second port16having one second main axis25perpendicular to the cross section of the second port16. The fluid control device100also has a third port18, which cannot be seen inFIG. 1, but is depicted inFIG. 2. The first main axis27and the second main axis25are aligned off-axis to one another.

The control means22is arranged within the housing10to control a fluid flow between the first port20and the second port16, as well as the third port18.

The control means22comprises a valve body24being rotatable around the first main axis27of the first port20for changing the position of a valve body24of the control means22.

The valve body24comprises a fluid path28for guiding the fluid through the valve body24. The fluid path28may be manufactured by drilling the valve body24. The valve body24has an outer surface section having at least partly a spherical shape, whereas at least a section of the inner surface38of the housing10has a spherical shape corresponding to the outer surface section of the valve body24. Accordingly, rotating of the valve body24within the housing10around the main axis27can easily be achieved, and the surface38of the housing10serves as a bearing for the valve body24. The housing10comprises a first shell12and a second shell14. The valve body24is mainly carried by the second shell14. The second shell14incorporates the second port16and the third port18(shown inFIG. 2), whereas the first port20is located in the first shell12. The first shell12closes the second shell14to get a sealed housing10.

In the first position34of the valve body24of the control means22, shown inFIG. 1, a fluid connection is established between the first port20and the second port16, thus enabling fluid flow from the second port16to the first port20via fluid path28and vice versa. The valve body24is arranged to provide a fluid connection alternatively between the first port20and the second port16and the second port16or between the first port20and at least a third port18.

The valve body24is two-dimensionally sealed to the first port20by gaskets40and to the second port16by gaskets40a.The fluid tightness may be ensured by a sealing area at the interface between the opening32of the fluid path28in the valve body24and the first port20provided in the housing10of the fluid control device100. The sealing area may be kept two-dimensional to ensure the reliability of the sealing function. This can be achieved by a gasket40around the two-dimensional plane of the opening32of the fluid path28in the valve body24in cylinder shape, sealed to the spherical inner surface38of the housing10around the first port20. In a similar way the valve body24is sealed to the inner surface38of the housing10with the gasket40aaround the opening30of the fluid path28and with the gasket40baround the closed area of the valve body24, if the valve body24is in the second position36, where the fluid path28is open from the first port20to the third port18and closed from the first port20to the second port16. Thus the second port16is sealed by the valve body24via the gasket40b.The seal grooves for the gaskets40,40a,40bare formed in the valve body24to receive the gaskets. The inner surface38of the housing10does not have any gasket groove shaped features in the sealing area.

The valve body24is rotatable by action of a driving mechanism located outside the housing10. For this purpose a rotating axle42of the valve body24is fed through the housing10in order to be coupled to an actuator as a driving mechanism of the control means22of the fluid control device100. Such an actuator can be a vacuum actuator, e.g., which is a very common type of actuator in combination with combustion engines, particularly in vehicles. Alternatively an electric actuator can be used for rotating the valve body24.

The housing10and/or the valve body24can favorably be made of plastics materials. It is advantageous to use, for instance, a Teflon segment for the sealing area of the valve body24and as a counterpart other plastics materials for the corresponding inner surface38of the housing10. Thus, a very efficient and reliable sealing function is achievable in an economic way.

InFIG. 1the first position34of the valve body24of the control means22with the fluid connection between the first port20and the second port16is shown, whereas inFIG. 2the second position36of the valve body24with the fluid connection between the first port20and the third port18is shown. In the second position36of a valve body24the fluid connection between the first port20and the second port16,18is closed.

FIG. 2depicts in a cross cut view the example embodiment of the fluid control device100according toFIG. 1in a second position36where the fluid path28is open from the first port20to a third port18. In this second position36the valve body24is rotated around the main axis27such that the fluid path28connects the first port20and the third port18and the fluid flow between the third port18and the first port20is enabled. The opening30of the fluid path28is connected to the third port18, whose main axis26is aligned off-axis to the main axis27of the first port20. The second port16is closed by the valve body24.

It is possible that in at least one position34,36of the valve body24or in a transition between end positions the second and third ports16,18may be at least partially open to the first port20, resulting in a mixing of the fluid flow from different branches of the fluid duct via the second and the third port16,18.

InFIG. 3an isometric view of the example embodiment of the fluid control device100according toFIG. 1with a first port20, a second port16, and a third port18is shown.

The housing10comprises a first shell12and a second shell14assembled and sealed together. The second shell14carries the second port16and in an axially distant position the third port18. The first shell12carries the first port20on top of the housing10. The first port20is always connected to the opening32of the valve body24to the fluid path28, as the valve body24is rotatable around the main axis27of the first port20.

In such a configuration the fluid control device100may represent an air intake shifter, which comprises the fluid control device100, having a first port20, a second port16and a third port18, wherein the first port20is alternatively coupleable to the second port16or the third port18by a control means22, which is rotatable about a main axis27of the first port20, which main axis27is perpendicular to the cross section of the first port20. In this case, the first port20is an air outlet and the second port16is an air inlet for charge air and the third port18is an air inlet for pulsating air. The charge air may be generated by a turbocharger, whereas the pulsating air may be generated by a resonance device. Thus it is possible to get more air into a combustion engine, to achieve a higher level of pulsation and to increase an engine efficiency.

Alternatively, if the fluid control device100carries only a first and a second port20,16, the fluid control device100may represent a fluid shutter including a fluid control device100, having a first port20and a second port16, wherein a fluid connection between the first port20and the second port16is switchable by a control means22, which is rotatable about a main axis27of the first port20, which main axis27is perpendicular to the cross section of the first port20. A shutter behavior of the fluid control device100may be realized where the fluid path28is open from the first port20to the second port16in one position34of the valve body24, whereas the fluid path28from the first port20to the second port16is closed in a second position36of the valve body24.