In internal combustion engines, throttle adjusting devices are used in the intake tube section and can regulate the air volume required by the internal combustion engine for the combustion of fuel. As a rule, the throttle adjusting devices include a drive mechanism, the throttle valve supported on a shaft, and a two-part throttle housing, which can be made of cast metal or as an injection-molded plastic part. In addition, the throttle housing is often provided with a separate housing cover, which can be used to seal the housing in order to prevent the intake of outside air.
DE 43 29 522 A1 has disclosed a throttle device, which can be built into the intake conduit of an internal combustion engine. The throttle device is comprised of a housing of a throttle valve control unit, a position sensor, and a throttle valve attached to a throttle valve shaft, the throttle device being disposed between the connection on the clean air side of an air filter and the intake system of the internal combustion engine. The air filter connection and/or the intake system are comprised of a plastic and the individual elements of the throttle device are designed in modular fashion and can be joined to one another by means of slid-together, screwed, or clamped connections. The housing and/or the throttle valve can be made of plastic; the throttle valve shaft is embodied in two pieces: the module for the position sensor can be disposed on one half of the shaft and the module for the throttle valve adjusting unit can be disposed on the other half of the shaft. The adjusting unit, the position sensor, and the throttle valve with the throttle valve shaft constitute a common unit, where the housing can be integrated into the air filter connection fitting or the intake system connection.
The subject of WO 95/02493 A1 is a shaped body comprised of plastic. This publication discloses a shaped body made of plastic, preferably produced using an injection molding process, and a throttle valve housing that has a wall whose inner wall surface borders a hollow chamber. An insert part that is covered by the plastic material is disposed inside the wall, at least on the inner wall surface oriented toward the hollow chamber. The insert part is inclined in relation to the normal plane in such a way that a pivotable throttle valve, which is disposed in the hollow chamber and is used to control the output of an internal combustion engine, is flush with this insert part in the idle position of the engine. According to this proposed embodiment, the insert part is made of metal, for example a sheet metal. The insert part includes a section which is bent out from a plane, and can be provided with deformations, in particular with openings that pass through the insert part.
DE 195 25 510 A1 relates to a throttle valve adjusting unit. The throttle valve adjusting unit includes a throttle valve fastened to a throttle valve shaft supported so that it can rotate in a throttle valve fitting. In addition, an adjusting motor, which is supported on the throttle valve fitting and is coupled to the throttle valve shaft, is provided for adjusting the throttle valve shaft. This adjusting motor includes at least one slider and at least one potentiometer path for detecting an adjustment position of the throttle valve shaft and an electrical connection to which the adjusting motor and the potentiometer are connected in a connection chamber. Furthermore, a cover is provided, which terminates in the connection chamber. The at least one potentiometer path is affixed to the cover and the cover has a coupling part formed onto it, which is part of the electrical connection. In addition the cover has at least one contact embodied on it, which electrically contacts a reciprocal motor plug contact connected to the adjusting motor when the cover is mounted onto the throttle valve connection.
With the embodiment proposed according to the invention, a throttle valve unit can be produced as an easy-to-use component through the use of multi-component techniques. The actual throttle valve can be manufactured with a frame part running around the edge of the throttle valve surface with a throttle valve shaft embodied as a one-piece component. The ends of the throttle valve shaft between the wings of the throttle valve surface can be produced as bearing pins within the required tolerances so that a throttle valve unit, which is embodied for example as a die-releasing throttle valve component, can be inserted into a throttle valve housing in few handling steps. If a throttle valve unit, which is embodied as die-releasing, i.e. without undercuts, is inserted into a bottom half of a throttle valve housing embodied in the intake tube section, then intermediary assembly steps and machine finishing operations can be eliminated.
The bottom housing half of the throttle valve housing can be embodied directly against an intake section tube of an internal combustion engine, which tube is likewise produced as an injection-molded plastic part, thus eliminating the installation step of attaching the throttle valve housing to the intake tube section in an internal combustion engine, which step can be a source of possible defective air intakes.
In order to fulfill the demands placed on the throttle valve unit with regard to imperviousness and ruggedness, a high-quality plastic is selected as the injection molding material for the throttle valve surface and components possibly injection molded onto it, as well as for a frame structure encompassing the throttle valve surface, in order to assure the required closing precision, the maintenance of dimensional stability, and a temperature stability of the throttle valve unit in all operating states of an internal combustion engine. If the throttle valve unit is produced in the course of the plastic injection molding, then it can be molded in one operation as a unit made of high-quality material. The split throttle valve housing, however, can be injection molded of a cheaper plastic, thus minimizing the quantity of high-quality plastic used.
During production of the throttle valve unit, not only can its bearing elements, i.e. the bearing pins of the throttle valve shaft, be manufactured in a dimensionally stable fashion within the required tolerances, but also if need be, driving features, driving gears, and receiving surfaces or recesses for sensor components can be produced in a single operation during the manufacture of the throttle valve unit. On the one hand, the above-listed attachments on the throttle valve unit can be directly injection molded onto it and on the other hand, these components can also be subsequently mounted onto a throttle valve unit produced in the plastic injection molding process.
With the embodiment proposed according to the invention, the geometry of a frame encompassing the valve surface can be varied in a simple manner, i.e. the material thickness of the frame encompassing the throttle valve surface and the resulting sealing action of the throttle valve unit in the intake tube section of an internal combustion engine can be adapted to the criteria furnished by the client.
The invention will be better understood and further objects and advantages thereof will become more apparent from the ensuing detailed description of preferred embodiments taken in conjunction with the drawings, in which
The depiction according to
The first embodiment of a throttle valve unit 1 shown in
In addition to an embodiment of the first frame part 3.1 and the second frame part 3.2 with a constant frame thickness 3.3, the frame part 3.1, 3.2 can also be embodied with a frame thickness 3.3 that changes over the circumferencial surface of the first wing 4.1 or of the second wing 4.2 of the valve surface 4. In order to reinforce the valve surface 4, it can be useful to embody the frame structure 3 at the transition points in the vicinity of the bearing pins 5 and 7 with a greater frame thickness 3.3 than the one in
In the end regions of the valve shaft 2, bearing pins 5 and 7 are formed onto the throttle valve unit 1, which is a one-piece component, preferably produced in a two-component injection molding process and injection molded of a high-quality plastic material. Ideally, the injection molding die exerts adjusting forces that are powerful enough to permit the die-releasing throttle valve unit 1 according to the depiction of
The throttle valve unit 1 according to
The drive element 10 can be formed directly onto the valve shaft 2 during the production of the throttle valve unit 1 in the course of the two-component injection molding process, i.e. injection molded onto it. The drive element 10 shown in
The throttle valve unit 1, which is shown by way of example in
A receiving surface 6 in the form of a flattened area is formed onto the region of the first bearing pin 5 of the valve shaft 2 and can be used to attach sensor elements or slip-on drive elements to the valve shaft 2 or throttle valve unit 1 according to FIG. 2.
The lower housing half 20 shown in a perspective top view in
In
For the sake of completeness, it should be noted that the drive housing 23 of the first housing half 20 is provided with locking elements 27 in which a locking element can lock in detent fashion after a drive mechanism, not shown here, is inserted into the hollow chamber 24 of the drive housing 23.
The depiction according to
The second housing half 30 of the throttle device has an upper receptacle half 33 formed onto it, which closes the lower receptacle half 26 formed onto the first housing half 20 shown in
A form-fitting element 31 is embodied on the second housing half 30. The form-fitting element 31 is disposed on the outer circumference surface of a fitting 34. An air hose leading from the air filter housing can be snapped on over the form fitting element 31. The wall 35 of the fitting 34 has an inner diameter 36, which corresponds to the cross section, which in the position of the one-piece throttle valve unit 1 shown in
Through the one-piece embodiment of the throttle valve unit 1, whether as a die-releasing component according to the depiction in
The foregoing relates to preferred exemplary embodiments of the invention, it being understood that other variants and embodiments thereof are possible within the spirit and scope of the invention, the latter being defined by the appended claims.
Number | Date | Country | Kind |
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101 37 771 | Aug 2001 | DE | national |
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Number | Date | Country | |
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20030024576 A1 | Feb 2003 | US |