Internal combustion engine

Abstract

An internal combustion engine for a motor vehicle included a crankshaft, at least one piston coupled to the crankshaft for performing strokes in a cylinder as a consequence of a rotation of the crankshaft. An eccentric shaft is coupled to the crankshaft and to the piston in such a manner that through it strokes of the piston are extendable. The internal combustion engine further includes a phase adjuster for adjusting a phase of the coupling of the eccentric shaft to the crankshaft and/or a stroke adjuster for adjusting strokes of the piston, in particular an extension of strokes of the piston by the eccentric shaft.

Claims

1. An internal combustion engine for a motor vehicle, comprising: a crankshaft; a piston coupled to the crankshaft for performing strokes in a cylinder as a consequence of a rotation of the crankshaft; an eccentric shaft coupled to the crankshaft and to the piston in such a manner that the strokes of the piston are extendable; an adjustment mechanism selected from the group consisting of a phase adjuster configured to adjust a phase of a coupling of the eccentric shaft to the crankshaft, and a stroke adjuster configured to adjust an extension of the stroke of the piston by the eccentric shaft; an adjustable crank drive operably coupling the crankshaft, the eccentric shaft and the piston; the adjustable crank drive comprising a first connecting rod coupled to the piston, a second connecting rod coupled to the eccentric shaft and a coupling link coupled to the crankshaft and interconnecting the first and second connecting rods; and the adjustment mechanism comprising the stroke adjuster configured to adjust a length of at least one of the first connecting rod, the second connecting rod or the coupling link.

2. The internal combustion engine according to claim 1 further comprising a second piston coupled to the crankshaft for performing strokes in a second cylinder as a consequence of the rotation of the crankshaft, wherein the eccentric shaft is coupled to the crankshaft and to the second piston in such a manner that the strokes of the second piston are extendable.

3. The internal combustion engine according to claim 2 further comprising a second stroke adjuster configured to adjust an extension of the stroke of the second piston by the eccentric shaft.

4. The internal combustion engine according to claim 1, wherein the eccentric shaft is coupled to the crankshaft through a transmission.

5. The internal combustion engine according to claim 4, wherein the adjustment mechanism comprises the phase adjuster configured to adjust an offset of the between a first link and a second link of the transmission for adjusting the phase of the coupling of the eccentric shaft to the crankshaft.

6. The internal combustion engine according to claim 4, wherein the transmission comprises a positively joined traction drive.

7. The internal combustion engine according to claim 1, wherein the adjustment mechanism comprises the phase adjuster configured to adjust the eccentric shaft between an initial position for extending expansion and exhaust strokes relative to at least one of intake or compression strokes by a first amount and an further position for extending expansion and exhaust strokes relative to at least one of intake or compression strokes by a second amount which is greater than the first amount.

8. The internal combustion engine according to claim 1, wherein the adjustment mechanism comprises the phase adjuster configured to reduce a deviation between expansion, exhaust, intake and compression strokes by an amount less than or equal to 50% of a maximum deviation.

9. The internal combustion engine according to claim 1, wherein the adjustment mechanism comprises the stroke adjuster positionable in an initial position for extending expansion, exhaust, intake and/or compression strokes relative to expansion, exhaust, intake and/or compression strokes in a further position thereof.

10. The internal combustion engine according to claim 1, wherein the adjustment mechanism comprises the phase adjuster and the stroke adjuster.

11. The internal combustion engine according to claim 1, wherein each of the phase adjuster and the stroke adjuster are selected from the group consisting of a hydraulic adjustor or an electric adjuster.

12. The internal combustion engine according to claim 1, further comprising a turbocharger configured for supercharged filling of the cylinder.

13. The internal combustion engine according to claim 1, further comprising a controller configured to control the adjustment mechanism for adjusting at least one of the phase of the coupling of the eccentric shaft to the crankshaft, or the strokes of the piston as a function of at least one operating parameter, wherein the operating parameter is selected from the group consisting of a load range, a rotational speed, a torque, a temperature, a charge pressure or a combination thereof.

14. An internal combustion engine for a motor vehicle, comprising: a crankshaft; a first piston coupled to the crankshaft for performing strokes in a cylinder as a consequence of a rotation of the crankshaft; an eccentric shaft coupled to the crankshaft and to the first piston in such a manner that the strokes of the first piston are extendable; an adjustment mechanism selected from the group consisting of a phase adjuster configured to adjust a phase of a coupling of the eccentric shaft to the crankshaft, and a stroke adjuster configured to adjust an extension of the stroke of the first piston by the eccentric shaft; a second piston coupled to the crankshaft for performing strokes in a second cylinder as a consequence of the rotation of the crankshaft, wherein the eccentric shaft is coupled to the crankshaft and to the second piston in such a manner that the strokes of the second piston are extendable; and a second stroke adjuster configured to adjust an extension of the stroke of the second piston by the eccentric shaft.

15. The internal combustion engine of claim 14, wherein the adjustment mechanism comprises the phase adjuster and the stroke adjuster.

16. An internal combustion engine for a motor vehicle, comprising: a crankshaft; a piston coupled to the crankshaft for performing strokes in a cylinder as a consequence of a rotation of the crankshaft; an eccentric shaft coupled to the crankshaft and to the piston in such a manner that the strokes of the piston are extendable; an adjustment mechanism selected from the group consisting of a phase adjuster configured to adjust a phase of a coupling of the eccentric shaft to the crankshaft, and a stroke adjuster configured to adjust an extension of the stroke of the piston by the eccentric shaft; the adjustment mechanism comprising the phase adjuster configured to adjust the eccentric shaft between an initial position for extending compression and expansion strokes relative to at least one of intake or exhaust strokes by a first amount and a further position for extending compression and expansion strokes relative to at least one of intake or exhaust strokes by a second amount which is greater than the first amount.

17. The internal combustion engine of claim 16, wherein the adjustment mechanism comprises the phase adjuster and the stroke adjuster.

18. An internal combustion engine for a motor vehicle, comprising: a crankshaft; a piston coupled to the crankshaft for performing strokes in a cylinder as a consequence of a rotation of the crankshaft; an eccentric shaft coupled to the crankshaft and to the piston in such a manner that the strokes of the piston are extendable; an adjustment mechanism selected from the group consisting of a phase adjuster configured to adjust a phase of a coupling of the eccentric shaft to the crankshaft, and a stroke adjuster configured to adjust an extension of the stroke of the piston by the eccentric shaft; the adjustment mechanism comprising the phase adjuster configured to adjust the eccentric shaft between an initial position for extending expansion and exhaust strokes relative to at least one of intake or compression strokes and a further position for extending compression and expansion strokes relative to at least one of intake or exhaust strokes.

19. The internal combustion engine of claim 18, wherein the adjustment mechanism comprises the phase adjuster and the stroke adjuster.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The present disclosure will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements.

(2) FIG. 1 illustrates a part of an internal combustion engine according to an embodiment of the present disclosure with a phase adjuster in a first position and a stroke adjuster in a first position;

(3) FIG. 2 illustrates the internal combustion engine with the phase adjuster in a further first position and the stroke adjuster in the first position;

(4) FIG. 3 is a graph showing strokes of a piston of the internal combustion engine in the first position the further first position of the phase adjuster and the first position of the stroke adjuster;

(5) FIG. 4 is a flow chart showing a method for operating the internal combustion engine according to an embodiment of the present disclosure;

(6) FIG. 5 illustrates the internal combustion engine with the phase adjuster in the first position of FIG. 1 and the stroke adjuster in a further position;

(7) FIG. 6 is a graph showing strokes of the piston in the first position of FIG. 1 of the phase adjuster and the first position as well as the further position of the stroke adjuster; and

(8) FIG. 7 is a flow chart showing a method for operating the internal combustion engine according to an embodiment of the present disclosure.

DETAILED DESCRIPTION

(9) The following detailed description is merely exemplary in nature and is not intended to limit the invention or the application and uses of the invention. Furthermore, there is no intention to be bound by any theory presented in the preceding background of the invention or the following detailed description.

(10) FIG. 1 shows a part of an internal combustion engine according to an embodiment of the present disclosure.

(11) The same includes a crankshaft 3 that is rotatably mounted about an axis of rotation 7, multiple, for example four, six, eight, ten or twelve pistons, of which in FIG. 1 only one piston 2 is exemplarily shown for the sake of clarity, and an eccentric shaft 13 that is rotatably mounted about an axis of rotation 14. The axes of rotation 7, 14 are offset parallel to one another. The pistons are identical in construction and function, so that in the following only the exemplarily shown piston 2 is explained and reference in this regard is made to the second pistons which are not shown. Complementarily, reference is also made to DE 10 2010 004 588 A1 mentioned at the outset. For this purpose, their reference characters are partly taken over.

(12) The eccentric shaft 13 is coupled via a gear transmission 15, which includes a gearwheel 17 that is rotationally fixed to the crankshaft 3 and a gearwheel 18 meshing therewith with double the number of teeth, which is coupled to an output 110 of the gear transmission 15 that is rotationally fixed to the eccentric shaft 13 via a phase adjuster 100, by way of which in a manner known per se, for example from camshaft adjustments, a phase of the coupling of the eccentric shaft 13 to the crankshaft 3 is adjustable or adjusted.

(13) The piston 2 is coupled to the crankshaft 3 for performing strokes in a cylinder 30 as a consequence of a rotation of the crankshaft through a crank drive 16, through which certain strokes are extendable within a cycle of intake, compression, expansion and exhaust stroke.

(14) For this purpose, the crank drive 16 includes a common coupling link 8 which is mounted on the crankshaft 3 in a crankpin joint 6 that is eccentric to the axis of rotation 7 and coupled to the piston 2 by a first (piston) connecting rod 4 that is mounted on the coupling link 8 in a rotary joint 11. A second (steering) connecting rod 19 is connected to the eccentric shaft 13 in a rotary joint 20 that is eccentric relative to the axis of rotation 14 and to the coupling link 8 in a rotary joint 23.

(15) In the exemplary embodiment, the rotary joint 20 or the connection, in which eccentric shaft 13 and second connecting rod 19 are coupled or connected to one another, is shiftable by a stroke adjuster 200 on the eccentric shaft 13 or the radius of the eccentric shaft 13, in which the same is connected to the second connecting rod 19, adjustable. This can in particular facilitate controlling or actuating the stroke adjuster 200. In modifications which are not shown, the rotary joint 20 can be additionally or alternatively shiftable or shifted on the second connecting rod 19 and/or the rotary joint 23 on the second connecting rod 19 and/or the coupling link 8 and/or the rotary joint 11 on the coupling link 8 and/or the first connecting rod 4 and/or the connection on the piston 2 by the stroke adjuster 200 of the same.

(16) By way of this, strokes of the piston 2, in particular their extension by the eccentric shaft 13, are adjustable. A motor ECU 120 contains data among others of a turbocharger 31 for the supercharged filling of the cylinders 30 and controls the phase adjuster 100 and the stroke adjuster 200 as indicated by dash-dotted signal arrows in FIG. 1.

(17) In the following, making reference to FIG. 1-4, only one phase adjustment according to an aspect of the present disclosure is initially explained, wherein the stroke adjuster 200 is kept constant in its first position shown in FIG. 1, 2. Accordingly, the stroke adjuster 200 can also be omitted or rotary joint 20 or the connection of the second connecting rod 19 to the eccentric shaft 13 can be constant or fixed in place relative to second connecting rod 19 and eccentric shaft 13 in a modification which is not shown.

(18) Following this, making reference to FIG. 1, 5-7, only one stroke adjustment according to a further aspect of the present disclosure is separately explained, wherein conversely the phase adjuster 100 is kept constant in its first position shown in FIG. 1, 5. Accordingly, the phase adjuster 100 can also be omitted in a modification which is not shown.

(19) In an embodiment, phase adjustment and stroke adjustment are combined with one another, wherein their separate explanation with reference to FIG. 1-4 on the one hand (phase adjustment) and FIG. 1, 5-7 on the other hand (stroke adjustment) merely serves for a more compact representation.

(20) In a first position S10 (see FIG. 4) of the phase adjuster 100 indicated in FIG. 1, the eccentric shaft 13 extends expansion strokes in expansion cycles E and exhaust strokes in exhaust cycles A relative to intake strokes in intake cycles S and compression strokes in compression cycles K as indicated in FIG. 3 in an expanded manner, in which the movement x of the piston 2 is indicated over the crankshaft angle KW of the crankshaft 3, thus realizing an Atkinson cycle process.

(21) As a function of at least one operating parameter of the internal combustion engine, for example in the case that a charge pressure of the turbocharger 31 falls below a given limit amount, the ECU 120 steers the phase adjuster 100 into a further first position S100 (see FIG. 4), which is indicated in FIG. 2. In this further first position of the phase adjuster 100, the eccentric shaft 13 now extends the expansion strokes in the expansion cycles E and the compression strokes in the compression cycles K relative to the intake strokes in the intake cycles S and the exhaust strokes in the exhaust cycles A, as is indicated with dashed lines in FIG. 3 thus realizing an inverted Atkinson cycle process.

(22) As a function of the at least one operating parameter of the internal combustion engine, the ECU 120 again steers the phase adjuster 100 into the one first position S10 (see FIG. 4).

(23) Additionally or alternatively, the ECU 100 controls the phase adjuster 100, as a function of at least one operating parameter, for example a load range of the internal combustion engine, starting out from the first position S10 shown in FIG. 1 into a further position S20 (see FIG. 4), in which the eccentric shaft 13 extends the expansion and exhaust strokes relative to the intake and compression strokes by a greater amount.

(24) Additionally or alternatively, the ECU 120 controls the phase adjuster 100, as a function of at least one operating parameter, for example the load range, of the internal combustion engine, starting out from the further first position S100 shown in FIG. 2, into a further second position S200 (see FIG. 4), in which the eccentric shaft 13 extends the compression and expansion strokes relative to the intake and exhaust strokes by a greater amount.

(25) With reference to FIG. 1, 5-7, a stroke adjustment is now explained, wherein the phase adjuster 100 is kept constant in its first position shown in FIG. 1, 5. Accordingly, the phase adjuster 100 can also be omitted in a modification that is not shown. In an embodiment, the phase adjustment explained above and the stroke adjustment explained in the following is or takes place combined with one another.

(26) As is illustrated in particular by the comparison of FIG. 1, 5 and FIG. 6, the expansion, exhaust, intake and compression strokes are extended relative to the corresponding strokes in a further position of the stroke adjuster 200 shown in FIG. 5 through the shifting of the rotary joint 20 on the eccentric shaft 13 or the corresponding adjustment of the connection of second connecting rod 19 on eccentric shaft 13 or of the radius of the eccentric shaft 13, in which the same is connected to the second connecting rod 19, through the stroke adjuster 200 in its first position shown in FIG. 1.

(27) Accordingly, the extension of individual strokes of the piston 2 within a cycle is also adjusted by the eccentric shaft 13 by the stroke adjuster 200.

(28) In the first position S1000 (see FIG. 7) of the stroke adjuster 200 indicated in FIG. 1, the eccentric shaft 13 extends expansion strokes in expansion cycles E and exhaust strokes in exhaust cycles A relative to intake strokes in intake cycles S and compression strokes in compression cycles K, as explained above with reference to FIG. 1-4 and likewise indicated expanded in FIG. 6, in which analogously to FIG. 3 the movement x of the piston 2 over the crankshaft angle KW of the crankshaft 3 is indicated.

(29) As a function of at least one operating parameter of the internal combustion engine, the ECU 120 steers the stroke adjuster 200 into the further position 52000 (see FIG. 7), which is indicated in FIG. 5. In this position, too, the eccentric shaft 13 extends expansion strokes in expansion cycles E and exhaust strokes in exhaust cycles A relative to intake strokes in intake cycles S and compression strokes in compression cycles K as indicated in dash-double dotted line in FIG. 6, however compared with the first position S1000, to a lesser extent.

(30) As already emphasized multiple times, the phase adjustment described here and the stroke adjustment described here can be realized individually or, in an embodiment, be advantageously combined with one another which advantageously increases the flexibility (of the cycle process) of the internal combustion engine or its operation, in particular its control. Accordingly, depending on the operating state or parameters of the internal combustion engine, it is possible to change from the state of FIG. 2 into the state of FIG. 5, i.e. both phase and also strokes or their extension adjusted.

(31) While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment as contemplated herein. It should be understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope of the invention as set forth in the appended claims.