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EP-4737695-A1 - INTAKE SYSTEM FOR INTERNAL COMBUSTION ENGINE WITH FLOW CONTROL SLIDER

EP4737695A1EP 4737695 A1EP4737695 A1EP 4737695A1EP-4737695-A1

Abstract

An intake system (1) for an internal combustion engine is provided. The intake system comprises an intake valve (70) for controlling the flow of a combustion gas into a cylinder of the internal combustion engine; a valvetrain (2) for actuating the intake valve (70); an inlet duct (170) leading to the intake valve (70) for guiding the combustion gas via the intake valve to the cylinder; a slider cavity (164) arranged at a side wall (172) of the inlet duct; a flow control slider (180) being accommodated in the slider cavity (164) and being translationally slidable between an extended position and a retracted position, and an additional gas supply system (160) passing through the slider cavity (164). In the extended position, the flow control slider (180) extends with a protruding portion (185) from the slider cavity (164) into the inlet duct (170) for shaping a flow of the combustion gas. In the retracted position, the flow control slider (180) is retracted, relative to the extended position, into the slider cavity (164).

Inventors

  • EISENBEIS, UWE

Assignees

  • Eisenbeis, Uwe

Dates

Publication Date
20260506
Application Date
20241105

Claims (15)

  1. An intake system (1) for an internal combustion engine, the intake system comprising: an intake valve (70) for controlling a flow of a combustion gas into a cylinder of the internal combustion engine; a valvetrain (2) for actuating the intake valve (70); an inlet duct (170) leading to the intake valve (70) for guiding the combustion gas via the intake valve to the cylinder; a slider cavity (164) arranged at a side wall (172) of the inlet duct; a flow control slider (180) being accommodated in the slider cavity (164) and being translationally slidable between an extended position and a retracted position; and an additional gas supply system (160) passing through the slider cavity (164), wherein in the extended position, the flow control slider (180) extends with a protruding portion (185) from the slider cavity (164) into the inlet duct (170) for shaping a flow of the combustion gas, and in the retracted position, the flow control slider (180) is retracted, relative to the extended position, into the slider cavity (164).
  2. The intake system (1) according to claim 1, wherein the valvetrain being at least one of the following: - A variable valvetrain adapted for continuously adjusting a valve lift of the intake valve (70); - adapted to be arranged in a cylinder head (3) portion of the internal combustion engine; - the valvetrain comprising: - an actuation system for periodically opening and closing the valve (70), the actuation system comprising at least one of a rotatable valve crank (16); and a transmission unit for transmitting the rotational movement of the valve crank (16) into a periodical lifting movement for actuating the valve (70), wherein preferably, the valve crank (16) is rotatably mounted about a valve crank axis (14) by a valve crank bearing (15), the valve crank bearing (15) connecting the valve crank (16) to a rigid support body (80) - the support body (80) is mounted on a pivot shaft (23) to be pivotable about a pivot axis (24), wherein pivoting of the support body (80) about the pivot axis (24) causes a change in position of the valve crank axis (14) along a circle segment about the pivot axis (24) for adjusting the valve lift; - the transmission unit comprises: - a connecting rod (30) with a first joint (34) and a second joint (36), and - a guiding member (60) for guiding the connecting rod, the guiding member being mounted on a guiding member shaft (63) to be pivotable about a guiding member axis (66), wherein preferably, the connecting rod (30) is joined with its first joint (34) to the valve crank (16), and the connecting rod (30) is joined with its second joint (36) to the guiding member (60); - the transmission unit further comprises - a pushing member (40) fastened to the guiding member (60), and - a transmission member (50) in mechanical contact with the pushing member (40) along a contact surface (54) for transmitting a force exerted by the pushing member (40) towards the valve (70).
  3. The intake system (1) according to any one of the preceding claims, wherein the protruding portion (185) is shaped as a nozzle element for constricting the inlet duct cross section and/or is adapted for generating a turbulent flow and/or a tumble flow when the flow control slider (180) is positioned in the extended position.
  4. The intake system (1) according to any one of the preceding claims, wherein a distal portion (184) of the flow control slider (180) is flush with the side wall of the inlet duct (170) when the flow control slider (180) is positioned in the retracted position.
  5. The intake system (1) according to any one of the preceding claims, wherein the flow control slider (180) is arranged for at least partially blocking an additional gas flow through the additional gas supply system (160) into the inlet duct (170) when positioned in the retracted position, and for allowing an additional gas flow through the additional gas supply system (160) into the inlet duct (170) when positioned in the extended position.
  6. The intake system (1) according to claim 5, wherein the flow control slider (180) comprises a channel recess (182), the channel recess (182) defining a channel for the additional gas flow into the inlet duct (170) when positioned in the extended position, wherein the channel recess (182) is preferably arranged at an upstream face of the flow control slider (180) relative to the direction of inlet gas flow along the inlet duct (170).
  7. The intake system (1) according to any one of the preceding claims, wherein the flow control slider (180) is arranged at a distance from the intake valve (70) of at most 60 mm.
  8. The intake system (1) according to any one of the preceding claims, wherein the intake system (1) further comprises an actuator system (190) for actuating the movement of the flow control slider (180) between the extended position and the retracted position.
  9. The intake system (1) according to claim 8, wherein the actuator system (190) is coupled to a variable valvetrain for actuating the movement of the flow control slider (180) in dependence of an adjusted valve lift of the variable valvetrain.
  10. The intake system (1) according to claim 8 or 9, wherein the actuator system comprises a rotatable actuation shaft (192) and a transmission system (191) for transmitting a rotation of the actuation shaft (192) into a translational sliding motion of the flow control slider (180), and preferably a crank eccentrically fixed to the actuation shaft (192) and connected to the flow control slider (180).
  11. The intake system (1) according to claim 10, wherein the actuation shaft (192) is spaced apart from the inlet duct (170), preferably by at least 50 mm.
  12. The intake system (1) according to any one of the claims 10 to 11, wherein the intake system (1) comprises a plurality of intake valves (70) and a plurality of inlet ducts (170) with respective flow control sliders (180), wherein the transmission system (191) is configured for transmitting a rotation of the actuation shaft (192) into a translational sliding motion of the flow control sliders (180).
  13. The intake system (1) according to claim 8 or 9, wherein the actuator system (190) comprises a linear actuation element coupled to the flow control slider (180).
  14. The intake system (1) according to any one of the preceding claims, wherein the intake system (1) comprises a plurality of intake valves (70) and a plurality of inlet ducts (170) with a plurality of respective flow control sliders (180), and wherein the pair of first and second flow control sliders (180, 180') are asymmetrical with respect to each other, and wherein preferably the first flow control slider (180) has a channel recess (182) not present in the second flow control slider (180').
  15. Internal combustion engine comprising an intake system according to any one of the preceding claims.

Description

The invention relates to an intake system for an internal combustion engine. Technical background Internal combustion engine, especially for vehicles, are operated under a variety of conditions and need to perform adequately well under these conditions. These conditions include full-load and partial load conditions, and in addition also low-flow conditions such as idling or low load. A variable valvetrain adapted to allow high performance as well as high fuel efficiency under a variety of such operation conditions is described in EP 1712747 A1 and a number of related applications cited further below. The present invention is based on the valvetrain described therein and regards an improvement of this valvetrain. Each of the various operation conditions of the combustion engine bring their own challenges. In particular, the low flow through the intake system may not automatically lead to a sufficiently well-mixed air-fuel mixture into the combustion chamber while the intake valves are open, so that imperfect combustion, and as a consequence, deteriorated combustion stability and fuel economy may result. Another challenge is the response time in response to a throttle command, as this response time may be delayed due to the low gas flow though the intake system. It is known that in these low-flow conditions, the combustion can be improved by controlling the turbulence within the combustion chamber of the fuel and air mixture immediately prior to combustion. Especially under low-flow conditions, the additional turbulences may improve the part-throttle / idle stability and the fuel economy. On the other hand, under high-flow conditions such as high or full load, high rate of gas flow directly into the cylinder is desirable. Under these conditions, the additional turbulences may lead to a deteriorated engine performance. In view of the above, various schemes for selectively introducing turbulences in the inlet system have been proposed. For example, EP 0521921 A1 describes an inlet arrangement including means such as a rotary member for varying the direction of gas flow past a respective intake valve. Other proposals are described in AT 521714 A1, DE 102011016644 A1, EP 0616116 A2, DE 10220340 A1, and DE 102007020926 A1. However, there is still room for additional improvements. Summary of the invention In view of the above, an intake system according to claims 1 and an internal combustion engine according to claim 15 are provided. According to the invention, the intake system comprises: an intake valve for controlling the flow of a combustion gas into a cylinder of the internal combustion engine; a valvetrain for actuating the intake valve; an inlet duct leading to the intake valve for guiding the combustion gas via the intake valve to the cylinder; a slider cavity (164) arranged at a side wall (172) of the inlet duct; and a flow control slider being accommodated in the slider cavity and being translationally slidable between an extended position and a retracted position. In the extended position, the flow control slider extends with a protruding portion from the slider cavity into the inlet duct for shaping a flow of the combustion gas. In the retracted position, the flow control slider is retracted, relative to the extended position, into the slider cavity. Furthermore, the intake system comprises an additional gas supply system passing through the slider cavity. An advantage of embodiments is that the flow control slider may re-direct the flow of intake gas and introduce additional turbulences when needed, but may be retracted when these additional turbulences are undesired. Furthermore, the additional gas supply system may further improve the gas flow, and in addition may allow for improved response time. According to embodiments, the above advantages are possible within a simple and compact setup. Further advantages, features, aspects and details that can be combined with embodiments described herein are evident from the dependent claims, the description and the drawings. Brief description of the Figures: The details will be described in the following with reference to the figures, wherein Fig. 1is a cross-sectional side view of an intake system according to an embodiment, with flow control slider in a retracted position;Fig. 2is a cross-sectional side view of the intake system of Fig. 1 with flow control slider in an extended position;Fig. 3is a perspective view of the intake system according to an embodiment;Fig. 4is a perspective view into the inlet duct of the intake system according to the embodiment of Fig. 3;Fig. 5is a side view of an intake system according to an embodiment, with flow control slider in a retracted position; andFig. 6is a cross-sectional side view of the intake system of Fig. 5 with flow control slider in an extended position. Detailed description of the Figures and of embodiments: Reference will now be made in detail to the various embodiments, one or more examples of which are illu