The present invention relates to an arrangement of the valve in a channel of a fresh gas system for supplying fresh gas to an internal combustion engine, in particular in a motor vehicle. The invention also relates to a fresh gas system equipped with such a valve arrangement.
An internal combustion engine has a fresh gas system comprising multiple channels for supplying fresh gas to the individual cylinders of the engine. So-called tumble valves may be arranged in these channels, which are also known as “intake pipes.” With the help of tumble valves, a charge flow can be generated for the respective cylinder as needed, said flow rotating parallel to the piston-bolt axis and perpendicular to the vertical axis of the cylinder, and thereby implementing a shifting charge operation In this way, the turbulent kinetic energy in the cylinder can be increased, which makes it possible to increase the quantity of exhaust gas recycled. Greater recycling rates lead to dethrottling of the internal combustion engine, which lowers its fuel consumption, and leads to a reduction in the combustion chamber temperature, which reduces NO2 production in the combustion process. Tumble valves are used primarily in gasoline engines.
So-called swirl valves may also be used in the channels or intake pipes. With the help of swirl valves, it is possible to generate a charge flow rotating about the vertical axis of the cylinder. With the help swirl valves, a channel of a pair of channels allocated to a cylinder can be closed to varying extents to thereby increase the turbulent kinetic energy in the combustion chamber. In this way the internal combustion engine can be adapted relatively accurately to different operating states. In addition to the advantages mentioned above which derive in combination with a tumble valve, particulate emissions can be reduced and the particle size decreased when using swirl valves, especially with diesel engines.
It is fundamentally possible to arrange such a valve in a rotationally fixed manner on a drive shaft. By rotating the drive shaft, the desired swivel adjustment of the valve can be implemented, with the drive shaft necessarily running coaxially with the swivel axis of the valve. Depending on the operating state of the internal combustion engine and depending on the valve setting, relatively high flow forces can act on the valve and must be absorbed by the drive shaft. In this way an operating device for swivel adjustment of the valve is exposed to relatively great loads and stresses. This may have negative effects on the lifetime of the actuating device. Likewise, the flow forces acting on the valves can trigger relative movements of the valves which may be associated with an unwanted noise production.
The present invention relates to the problem of providing an improved embodiment for a valve arrangement of the type defined in the preamble and/or a fresh gas system equipped with such a valve such that this embodiment is characterized in particular by reduced stress on the respective actuating device.
This problem is solved according to this invention by the features of the independent claims. Advantageous embodiments are the subject matter of the dependent claims.
The present invention is based on the general idea of driving the respective valve with the help of a separate actuator for pivoting, in which case the respective actuator acts eccentrically on the valve with respect to the pivot axis of the valve. Due to the eccentric introduction of force into the valve, advantageous lever forces can be achieved so that on the one hand only relatively low adjusting forces are required for adjusting the valve while on the other hand the flow forces acting on the valve are transmitted in a reduced form according to the lever action when they are transferred to the actuator and thus to the actuating device. The loads acting on the actuating device are therefore reduced, so that the latter device has a longer lifetime while retaining the same stability or it may be designed with a reduced stability while maintaining the same lifetime and therefore may be manufactured less expensively.
The actuating device may preferably be designed so that when the actuator is actuated, it rotates about an axis of rotation running parallel with and eccentric to the pivot axis. Then the actuator is connected to a drive shaft in a rotationally fixed manner, the drive shaft running parallel and eccentric to the pivot axis and extending coaxially with the axis of rotation in particular. In this way it is possible in particular to arrange an actuating drive for driving the drive shaft outside of the channel, In particular, this also makes it possible to provide a common actuating drive for multiple actuators, expediently driving the actuators in synchronization via a common drive shaft.
The valve may be mounted in pivot bearings, e.g., by means of bearing journals extending coaxially with the pivot axis. Likewise the valve may be arranged on a bearing shaft extending coaxially with the pivot axis. In particular, several valves of neighboring valve arrangements may be arranged simultaneously on such a bearing shaft. This common bearing shaft and the joint drive shaft which is expediently provided then extend in parallel and eccentrically, i.e., at a distance from one another, to implement the aforementioned advantageous lever ratios.
Additional important features and advantages of the invention are derived from the subclaims, the drawings and the respective description of the figures on the basis of the drawings.
It is self-evident that the features mentioned above and those yet to be explained below may be used not only in the particular combination given but also in other combinations or alone without going beyond the scope of the present invention.
Preferred exemplary embodiments of the invention are depicted in the drawings and explained in greater detail in the following description, where the same reference numerals refer to the same or similar or functionally same components.
They each show, in schematic diagrams,
According to
At least one of the channels 2 is equipped with an inventive valve arrangement 4 which is explained in greater detail with reference to
According to
In the embodiments shown here, the actuator 8 is mounted so it is rotationally adjustable about an axis 9 of rotation. The actuator 8 rotates about this axis of rotation 9 in pivot actuation of the valve S. This axis of rotation 9 extends parallel to the pivot axis 6 but is also eccentric with respect to the pivot axis 6, i.e., is arranged at a distance from it. A drive shaft 10 to which the actuator 8 is attached in a rotationally fixed manner is preferably also provided. This drive shaft 10 extends here coaxially with the axis of rotation 9 and thus runs in parallel with and eccentrically to the pivot axis 6. The rotationally fixed coupling between the actuator 8 and the drive shaft 10 is accomplished here by a form-fitting connection.
In addition, a trough 11 may be provided for accommodating the valve 5 in the starting position. This trough 11 is designed in a channel wall 12 which borders the channel 2. The valve 5 is arranged so it is countersunk in this trough 11 in the starting position. A front side 14 of the valve 5 is exposed to the channel 2, i.e., to the fresh gas flow 13 (indicated here by arrows), which develops during operation of the internal combustion engine, and is arranged in a manner such that it is integrated into the contour in an inside contour 15 of the channel wall 12 which is exposed to the fresh gas flow 13. The actuator 8 is expediently also arranged in this trough 11 and is thus countersunk in the channel wall 12. Therefore, the axis of rotation 9 and the drive shaft 10 are arranged so they are countersunk in the channel wall 12.
The valve 5, which is countersunk in the trough 11, is more or less outside of the fresh gas flow 13 and has essentially no interfering influence on the flow.
According to
In the embodiment shown here the valve 5 is mounted on a bearing shaft 18. The bearing shaft 18 extends coaxially to the pivot axis 6. In the exemplary embodiment shown here the valve 5 is arranged on the bearing shaft 18 in a rotationally fixed manner, which is achieved by a corresponding form-fitting coupling, for example. Accordingly in this embodiment the bearing shaft is mounted to rotate about the pivot axis 6 in a suitable manner, preferably being mounted on the channel block 3. In particular it is possible in this way to arrange outside of the channel 2 a restoring spring that acts on the bearing shaft 18 and prestresses the valve 5 in its starting position. Such a restoring spring is illustrated in
As an alternative, an embodiment in which the valve 5 is mounted on the bearing shaft 18 to pivot about the pivot axis 6 is also possible. The bearing shaft 18 itself may then be arranged in a rotationally fixed manner. A corresponding restoring spring then acts directly on the valve 5, to which end it is arranged inside the channel 2.
Like the bearing shaft 18, the pivot axis 6 here is also arranged in the trough 11, i.e., is countersunk in the channel wall 12.
On its axial ends with respect to the pivot axis 6, the valve 5 here is equipped with side walls 20 which extend parallel to the channel wall in a wall niche 21 in the channel 2. This wall niche 21 may be shaped in such a way that it forms an end stop in the end position of the valve 5 shown in
According to
According to
Here again, the valve 5 is preferably arranged so that it is countersunk in the channel wall 12 in the starting position, to which end the channel wall may again be equipped with a trough 11. The front side 14 of the valve 15 is also designed to be shape-integrated with regard to the inside contour 15 of the channel wall 12 for the starting position.
The gearwheel 8 is also arranged countersunk in the channel wall 12. In the special embodiment shown here, the channel wall 12 has an opening 34 in the area of the gearwheel 8 so that the gearwheel 8 protrudes through this opening from the outside through the channel wall 12 into the channel 2 and/or into the trough 11 as far as the gearwheel segment 31. On a side facing away from the channel 2, said opening 34 is closed by a cover 35 which surrounds the gearwheel 8 and the drive shaft 1a. Through appropriate contouring or formation of a niche on channel walls adjacent to the side walls 32 of the valve 5 and/or walls 36 insertable into the channel 2, an end stop 37 for the end position shown in
In the embodiment shown here, the valve 5 is equipped with two bearing journals 39 extending coaxially with the pivot axis 6. The bearing journals 39 are formed on the side walls 32 and are each mounted so they can rotate about the pivot axis 6 in a pivot bearing 40. These pivot bearings 40 are preferably designed in the walls 36 inserted into the channel 2 and/or into the channel block 3. These walls 36 in turn form wall sections of the channel 2.
For a definition of the end position shown in
The bearing sleeves 43 are therefore inserted into first bearing half shells 44 which are formed on the channel block 3. Second bearing half shells 45 are formed on the cover 35 and complete the support and/or mounting of the bearing sleeves 43.
According to
A joint bearing shaft on which the valves 5 of the respective actuating devices 4 are jointly arranged is preferably also provided for bearing the valves 5. The joint drive shaft 10 and/or the joint bearing shaft 18 is/are also suitable in assembly of the fresh gas system 1 for securing the components of the valve arrangements 4, which are inserted into the channel block 3, on the channel block 3 in a form-fitting manner.
According to
The valves 5 shown here are designed as tumble valves in an exemplary manner; with their help a shift charge operation for the internal combustion engine can be implemented in particular. Likewise the valves 5 may be swirl valves or any other valves 5, e.g., throttle valves which are arranged in the channels 2 of the fresh gas system 1 in a cylinder-specific arrangement.
Number | Date | Country | Kind |
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10 2005 029 193.7 | Jun 2005 | DE | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/DE06/01027 | 6/16/2006 | WO | 00 | 8/5/2008 |