Internal Combustion Engine for a Motor Vehicle, in Particular for a Car

Abstract

An internal combustion engine of a motor vehicle includes an output shaft and a spring element which can rotate with the output shaft which is to be tensioned as a result of a deactivation of the internal combustion engine by a rotation of the output shaft, where a spring force can be provided by the spring element and where by the spring force the output shaft can be set into rotation in the event of a start following the deactivation. Via a locking device the output shaft is to be secured against a rotation after tensioning the spring element and while the spring element is tensioned. A blocking device can be shifted between a blocking state securing a first part of the spring element, which has a second part non-rotationally connected to the output shaft, against a rotation and a release state releasing the first part for a rotation.

Claims

1.-3. (canceled)

4. An internal combustion engine (16) of a motor vehicle, comprising: an output shaft (24) which is rotatable around an axis of rotation (26) relative to a housing (22) of the internal combustion engine (16), wherein a torque is providable by the internal combustion engine (16) for driving the motor vehicle via the output shaft (24); a spring element (34) which is rotatable with the output shaft (24), wherein the spring element (34) is tensionable as a result of a deactivation of the internal combustion engine (16) by rotation of the output shaft (24) relative to the housing (22) around the axis of rotation (26), wherein a spring force is providable by the spring element (34) by tensioning the spring element (34), wherein the output shaft (24) is settable in rotation relative to the housing (22) around the axis of rotation (26) during a start of the internal combustion engine (16) following the deactivation by the spring force, and wherein the spring element (34) has a first part (T1) and has a second part (T2) that is non-rotationally connected to the output shaft (24); a locking device (36), wherein the output shaft (24) is securable against rotation relative to the housing (22) around the axis of rotation (26) after the spring element (34) has been tensioned and while the spring element (34) is tensioned by the locking device (36); a blocking device (38), wherein the blocking device (38) is adjustable between a first blocking state securing the first part (T1) of the spring element (34) against a rotation taking place relative to the housing (22) around the axis of rotation (26) and a first release state releasing the first part (T1) for a rotation taking place relative to the housing (22) around the axis of rotation (26); a blocking element (40), wherein the blocking element (40) is formed separately from the spring element (34) and is non-rotationally connected to the first part (T1) of the spring element (34) and interacts in the blocked state with the blocking device (38), wherein the blocking element (40) and, via the blocking element (40), the first part (T1) of the spring element (34) are securable against a rotation taking place in relation to the housing (22) around the axis of rotation (26); wherein the locking device (36) is movable between a second blocking state securing the output shaft (24) against rotation taking place in relation to the housing (22) around the axis of rotation (26) and a second release state releasing the output shaft (24) for rotation taking place in relation to the housing (22) around the axis of rotation (26); and a flywheel (28) formed separately from the output shaft (24), wherein the flywheel (28) is rotatable together with the output shaft (24) and wherein the locking device (36) cooperates in a form-fit manner with the flywheel (28) in the second blocking state; wherein the flywheel (28) and the blocking element (40) are disposed on respective sides (30, 32) of the output shaft (24) which are opposite one another in an axial direction of the output shaft (24).

5. The internal combustion engine (16) according to claim 4, wherein the blocking device (38) in the first blocking state interacts in a form-fit manner with the blocking element (40).

6. The internal combustion engine (16) according to claim 4, further comprising a sensor (50), wherein a rotational speed of the output shaft (24) is detectable by the sensor (50), wherein an electrical signal characterizing a detected rotational speed is providable by the sensor (50), and wherein the blocking device (38) and/or the locking device (36) are drivable depending on the electrical signal.

Description

BRIEF DESCRIPTION OF THE DRAWING

[0029] In the single FIGURE, the drawing sectionally shows a schematic depiction of a drivetrain of a motor vehicle, wherein the drivetrain comprises an internal combustion engine according to the invention.

DETAILED DESCRIPTION OF THE DRAWING

[0030] The single FIGURE sectionally shows a schematic depiction of a drivetrain 10 of a motor vehicle designed in particular as a motor vehicle and preferably as a passenger car. This means that the motor vehicle in its fully manufactured state comprises the drivetrain 10. In addition, the motor vehicle in its fully manufactured state comprises, for example, at least or exactly two axles arranged one behind the other in the longitudinal direction of the vehicle, of which one axle labelled with 12 is shown in the FIGURE. The axle 12 comprises at least or exactly two vehicle wheels 14 spaced apart from each other in the transverse direction of the vehicle and simply also referred to as wheels. Moreover, the drivetrain 10 comprises an internal combustion engine 16 in the form of a reciprocating piston engine, by means of which the wheels 14 and thus the motor vehicle as a whole can be driven by an internal combustion engine via a transmission 18 of the drive train 10. The gearbox 18 is, for example, a change-speed gearbox and thus comprises several gears or gear steps which can be engaged and disengaged. The axle 12 comprises an axle gear 20, also referred to as a differential gear, via which the wheels 14 can be driven by the gearbox 18.

[0031] The internal combustion engine 16 has a housing 22, for example in the form of a crank housing, in particular a cylinder crank housing, and an output shaft 24, for example in the form of a crankshaft, which is mounted on the housing 22 so as to be rotatable around an axis of rotation 26 relative to the housing 22. Via or by means of the output shaft 24, the internal combustion engine 16 can provide torques, by means of which the wheels 14 can be driven via the axle drive 20 and the gearbox 18.

[0032] For example, the internal combustion engine 16 has at least one combustion chamber which is partially bounded or formed by a cylinder formed by the housing 22. During a fired operation of the internal combustion engine 16, the internal combustion engine 16 is activated, whereby combustion processes take place in the combustion chamber during the fired operation. By means of these combustion processes, the output shaft 24 is driven and thus rotated around the axis of rotation 26 relative to the housing 22. The internal combustion engine 16 has a flywheel 28 which is formed separately from the output shaft 24 and can rotate with the output shaft 24, which flywheel 28 is formed, for example, as a dual-mass flywheel (ZMS) and can implement a particularly smooth running of the internal combustion engine 16. The flywheel 28 is arranged on an output side 30 of the internal combustion engine 16 or the output shaft 24, whereby the transmission 18 is also arranged on the output side 30.

[0033] On a side 32 of the internal combustion engine 16 or of the output shaft 24 opposite the output side 30 in the axial direction of the output shaft 24 and also referred to as the control or front side, a spring 34 is provided which can rotate with the output shaft 24 and is also referred to as a spring element.

[0034] If the combustion engine 16, which is initially activated and thus in its fired mode, is deactivated, the combustion processes taking place in the combustion chamber or in the combustion engine 16 as a whole are terminated. Due to its inertia, however, the output shaft 24 continues to rotate for a certain time, such that the output shaft 24 coasts down as a result of the deactivation of the internal combustion engine 16, i.e., passes into a so-called coasting down or engine coasting down. During coasting, the output shaft 24 is not driven, such that the speed of the output shaft 24 is reduced.

[0035] The spring 34 is to be tensioned or is tensioned during the run-down of the output shaft 24 resulting from a deactivation of the internal combustion engine 16 by a rotation of the output shaft 24 taking place during the run-down and relative to the housing 22 around the axis of rotation 26, i.e., by rotational energy of the output shaft 24, such that the spring 34, as a result of its tensioning, provides a spring force by means of which, during a start of the internal combustion engine 16 following the deactivation, the output shaft 24 can be set in rotation or is set in rotation relative to the housing 22 around the axis of rotation 26. This can, for example, support or effect the start of the internal combustion engine 16.

[0036] The internal combustion engine 16 also has a locking device 36. This is held, for example, at least indirectly, in particular directly, on the housing 22. In particular, the locking device 36 is secured against rotation around the axis of rotation 26 relative to the housing 22. As will be explained in more detail below, the locking device 36 is used to secure the output shaft 24 against rotation relative to the housing 22 around the axis of rotation 26 after the spring 34 has been tensioned and while the spring is tensioned. By securing the output shaft 24 against rotation around the axis of rotation 26 relative to the housing 22 by means of the locking device 36, for example, at least part of the spring 34 is also secured against rotation around the axis of rotation 26 relative to the housing 22.

[0037] In order to now be able to implement a particularly advantageous operation of the internal combustion engine 16, the internal combustion engine 16 has a blocking device 38 which is provided in addition to the locking device 36 and, in particular, is designed separately from the locking device 36. The blocking device 38 is, for example, held at least indirectly, in particular directly, on the housing 22. In particular, the blocking device 38 is secured against rotation around the axis of rotation 26 relative to the housing 22. The blocking device 38 can be adjusted or switched between a first blocking state and a first release state.

[0038] In the blocked state, at least a first part T1 of the spring element (spring 34) is secured against rotation around the axis of rotation 26 relative to the housing 22 by means of the blocking device 38, for example in such a way that the first part T1 is connected to the housing 22 in a rotationally fixed manner by means of or via the blocking device 38. The spring 34 also has a second part T2, which is spaced from the first part T1 in the axial direction of the output shaft 24 and in the axial direction of the spring 34, the axial direction of which coincides with the axial direction of the output shaft 24. The second part T2 is non-rotatably connected to the output shaft 24 and can thus rotate with the output shaft 24. For example, the parts T1 and T2 are formed integrally with each other. Alternatively or additionally, the parts T1 and T2 form at least one part of at least one spring coil of the spring 34. In the exemplary embodiment shown in the FIGURE, the spring 34 is designed as a torsion or rotation spring. In the first release state, the blocking device 38 releases the part T1 for rotation around the axis of rotation 26 relative to the housing 22. In other words, in the first blocking state, the part T1 cannot be rotated around the axis of rotation 26 relative to the housing 22 as this is prevented by the blocking device 38. However, in the first release state, the part T1 can be rotated around the axis of rotation 26 relative to the housing 22.

[0039] The locking device 36 can be switched or adjusted between a second blocking state and a second release state. In the second blocking state, the locking device 36 secures the output shaft 24 against rotation around the axis of rotation 26 relative to the housing 22. Since the part T2 is non-rotatably connected to the output shaft 24, in the second blocked state the part T2 is secured against rotation around the axis of rotation 26 relative to the housing 22 via the output shaft 24 by means of the locking device 36, such that, in the second blocked state, the output shaft 24 and the part T2 cannot rotate around the axis of rotation 26 relative to the housing 22. In the second release state, however, the locking device 36 releases the output shaft 24 and thus the part T2 for rotation around the axis of rotation 26 relative to the housing 22, such that in the second release state the output shaft 24 and with it the part T2 can rotate around the axis of rotation 26 relative to the housing 22. If, for example, the locking device 36 and the blocking device 38 are in their respective release states and the output shaft 24 is driven by combustion processes taking place in the internal combustion engine 16 and thus rotated around the axis of rotation 26 relative to the housing 22, the spring 34, in particular the entire spring 34, can simply rotate with the output shaft 24 around the axis of rotation 26 relative to the housing 22.

[0040] However, if, for example, the output shaft 24 and with it the part T2 rotate around the axis of rotation 26 relative to the housing 22 while the blocking device 38 is in its first locking state, the parts T1 and T2 are rotated around the axis of rotation 26 relative to each other. This causes the spring 34 to be tensioned, and thus charged or loaded. This converts rotational energy of the rotating output shaft 24 into spring energy or potential energy, which is stored in the spring 34. If, for example, the locking device 36 is then moved into its second locking state while the blocking device 38 is still in the second locking state and the spring is tensioned, the spring 34 is kept tensioned.

[0041] If, for example, the locking device 36 is then moved into its second release state during the aforementioned start, in particular while the locking device 38 is still in its first locking state, the spring 34 can at least partially relax. Thus, the output shaft 24 is accelerated and thus driven by means of the spring 34 or by means of its spring force and thus rotated around the axis of rotation 26 relative to the housing 22, whereby the internal combustion engine 16 is started or can be started. Of course, for example, in particular a short time after the output shaft 24 has been rotated by means of the spring force of the spring 34 in order to start the internal combustion engine 16, the blocking device 38 is also moved into its first release state, such that the output shaft 24 can then be driven by combustion processes taking place in the internal combustion engine 16 and can thus be rotated around the axis of rotation 26 relative to the housing 22 without this being excessively impaired by the spring 34, the locking device 36 or the blocking device 38.

[0042] In the exemplary embodiment shown in the FIGURE the spring 34 is arranged at a front end of the output shaft 24 and is non-rotatably connected to the output shaft 24 at the front end, such that the part T2 is non-rotatably connected to the front end.

[0043] Furthermore, a blocking element 40 is provided which is formed separately from the spring 34 and is also referred to as a positive locking element, blocking disc or locking disc. In the axial direction of the output shaft 24, the spring 34 is arranged at least partially, in particular at least extensively or completely, between the blocking element and the output shaft 24. In this case, the part T1 is connected to the blocking element 40 in a rotationally fixed manner. The blocking element 40 has recesses 42 on its periphery or across its periphery, in particular evenly distributed recesses 42, which are formed as bores, for example. The blocking device 38 has an actuator 44 and a further blocking element 46, for example in the form of a pin or bolt, which can be moved by means of the actuator 44 in a movement direction illustrated in the FIGURE by a dashed line 48 relative to the blocking element 40, in particular translationally. The movement direction is oblique or perpendicular to the axis of rotation 26. This means, for example, that a first plane perpendicular to the axis of rotation 26 is perpendicular to a second plane perpendicular to the direction of movement. In the first blocking state, the blocking element 46, which is for example in the form of a locking pin, engages in one of the recesses 42, as a result of which the blocking device 38 interacts with the locking element 40 in a form-fitting manner. As a result, the locking element 40 and, via it, the part T1 are secured in a form-fit manner by means of the blocking device 38 against rotation relative to the housing 22 around the axis of rotation 26.

[0044] If the internal combustion engine 16, which is initially activated and thus in its fired mode, is deactivated, for example, i.e., switched off, then ignition and injection are switched off, such that fuel is no longer introduced into the combustion chamber of the internal combustion engine 16 and ignitions taking place in the combustion chamber cease. As a result, the output shaft 24 goes into its run-down, such that the rotational speed of the output shaft 24 decreases.

[0045] Here, the internal combustion engine 16 has a sensor 50 by means of which, for example, a rotational speed of the output shaft 24 is detected. In particular, a rotational speed of the flywheel 28 and, via this, the rotational speed of the output shaft 24 is detected by means of the sensor 50. The sensor 50 provides, for example, a signal, in particular an electrical signal, which characterizes the rotational speed detected by the sensor 50. An electronic computing device 52 of the internal combustion engine 16 shown particularly schematically in the FIGURE receives, for example, the signal provided by the sensor 50 and characterizing the rotational speed and can then, for example, control the locking device 36 and/or the blocking device 38 as a function of the received signal, such that, for example, the locking device 36 and/or the blocking device 38 can be operated or are operated as a function of the detected rotational speed. In particular, the sensor 50 is designed to detect respective rotational or angular positions of the output shaft 24 or the flywheel 28 and, as a consequence, the rotational speed of the flywheel 28 or the output shaft 24. Since, for example, the flywheel 28 is connected to the output shaft 24 in a rotationally fixed manner, the rotational speed of the flywheel 28 corresponds to the rotational speed of the output shaft 24.

[0046] For example, the respective angular or rotational position of the flywheel 28 or the output shaft 24 detected by means of the sensor 50 is compared with a so-called stop map or with data or positions stored in the stop map, whereby the stop map and thus its data or positions are stored in the electronic computing device 52, for example. By comparing the rotational positions detected by means of the sensor 50 with the stored positions, a forecast can be made about a further future course of the rotational speed of the output shaft 24. For example, the locking device 36 and/or the blocking device 38 are operated depending on the forecast.

[0047] The flywheel 28 has recesses 54 on its outer periphery, in particular evenly distributed recesses, which can be designed as bores, for example. The locking device 36 has a second actuator 56 and a locking element 58, for example in the form of a bolt. The locking element 58 is formed, for example, as a locking bolt. The locking element 58 can be moved by means of the actuator 56 in a second movement direction relative to the flywheel 28 or relative to the output shaft 24, in particular translationally, as illustrated in the FIGURE by a dotted line 60. The second movement direction runs, for example, obliquely or perpendicularly to the axis of rotation 26, such that, for example, a third plane running perpendicularly to the second movement direction runs perpendicularly to the plane which runs perpendicularly to the axis of rotation 26.

[0048] In the first release state, there is no engagement of the blocking element 46 with the or all recesses 42, such that there is no interaction between the blocking element 46 and the blocking element 40. As a result, the blocking device 38 releases the blocking element 40 and thus the part T1 for rotation around the axis of rotation 26 relative to the housing 22.

[0049] In the second blocking state, the locking element 58 engages in one of the recesses 54 formed, for example, as bores, such that in the second blocking state the locking device 36 interacts positively with the flywheel 28. As a result, the flywheel 28 and, via the flywheel, the output shaft 24, are positively secured by means of the locking device 36 against rotation around the axis of rotation 26 relative to the housing 22. In the second release state, however, the locking element 58 does not engage in the or all recesses 54 of the flywheel 28, such that in the second release state the locking device 36 releases the flywheel 28 and thus the output shaft 24 for rotation around the axis of rotation 26 relative to the housing 22.

[0050] For example, when the output shaft 24 runs out, the sensor 50 detects the respective rotational positions, also referred to as rotational locations, and the rotational speed of the output shaft 24, in particular via the flywheel 28. If the rotational speed of the output shaft 24 has fallen below a predetermined or predeterminable threshold value, for example, which corresponds, for example, to the idling speed of the internal combustion engine 16, the blocking element 46 is triggered. This means that the blocking device 38 is brought out of its first release state into its first blocking state, as a result of which the blocking element 40 and, via the latter, the part T1 are non-rotationally locked, i.e., are secured against rotation around the axis of rotation 26 relative to the housing 22. However, since the locking device 36 is still in its second release state, the output shaft 24 can still rotate, whereby the output shaft 24 is braked by means of the spring 34. In the process, the spring 34 is twisted, i.e., tensioned or charged. In particular, the output shaft 24 is braked during its run-down by means of the spring 34, which is designed as a torsion spring, for example, in such a way that the output shaft 24 comes to a standstill. After the output shaft 24 has come to a standstill, the output shaft 24 is rotated backwards, for example, by means of the then tensioned spring 34 until the output shaft 24 comes to a standstill again. In the second standstill of the output shaft 24, for example, the blocking element 58 is triggered, i.e., the locking device 36 is moved from its second release state into its second blocking state. This locks the output shaft 24, thus securing it against rotation around the axis of rotation 26 relative to the housing 22. The spring 34 is then tensioned and is kept tensioned, in particular in such a way that when the locking device 36 is moved from its blocked state to its second released state, the spring 34 or its spring force causes the output shaft 24 to rotate in the first direction of rotation. Thus, the output shaft 24 is accelerated or rotated for the start in the correct first direction of rotation.

[0051] Thus, during fired operation, the output shaft 24 is rotated around the axis of rotation 26 relative to the housing 22 in a first direction of rotation. The output shaft 24 is to be rotated in this first direction of rotation to start the internal combustion engine 16. During its coasting, the output shaft 24 continues to rotate in the first direction of rotation without being driven. Here, the output shaft 24 is braked by means of the spring 34, whereby the spring 34 is tensioned.

[0052] After this standstill, the output shaft 24 is rotated back around the axis of rotation 26 relative to the housing 22 by means of the then tensioned spring 34, i.e., rotated in a second direction of rotation opposite to the first directions of rotation, in particular until the output shaft 24 comes to its, in particular second, standstill again. In this second standstill, the spring 34 is tensioned and the locking device 36 is moved from its second release state into its second locking state.

[0053] For example, if the blocking member 58 is then retracted such that it no longer engages in the recess 54 such that the locking device 36 is moved to its second release state, the spring 34 can relax. As a result, the output shaft 24 is rotated in the first direction of rotation, whereby a start of the internal combustion engine 16 can be performed, that is, caused or assisted.

[0054] For example, for a conventional start, the first cylinder whose piston passes its top dead centre is fired and then all the following cylinders. For a direct start, the cylinder whose piston had already passed its top ignition dead centre at standstill is fired and then all the following cylinders. As soon as the spring 34 has rotated the output shaft 24 during the start in such a way that the spring 34 is released, the locking element 46 is also retracted, i.e., the locking device 38 is moved into its first release state, such that the spring 34 does not hinder the start or an associated start-up of the internal combustion engine 16.

LIST OF REFERENCE CHARACTERS

[0055] 10 Drivetrain [0056] 12 Axis [0057] 14 Vehicle wheel [0058] 16 Internal combustion engine [0059] 18 Transmission [0060] 20 Axle transmission [0061] 22 Housing [0062] 24 Output shaft [0063] 26 Axis of rotation [0064] 28 Flywheel [0065] 30 Output side [0066] 32 Side [0067] 34 Spring [0068] 36 Stopping device [0069] 38 Blocking device [0070] 40 Blocking element [0071] 42 Recess [0072] 44 Actuator [0073] 46 Blocking element [0074] 48 Dashed line [0075] 50 Sensor [0076] 52 Electronic computing device [0077] 54 Recess [0078] 56 Actuator [0079] 58 Stopping element [0080] 60 Dashed line [0081] T1 First part [0082] T2 Second part