EP2321522B1 - Method for engaging a starting gear pinion of a starter device in a ring gear of an internal combustion engine - Google Patents

Description

State of the art

From the German published application DE 10 2006 011 644 A1 a method is known of how two moving gears of a starting device and an internal combustion engine (pinion and ring gear) can be brought into engagement with one another in the dynamic case. The case is already described there that the pinion should be engaged in the ring gear of the internal combustion engine in the so-called run-down phase of the internal combustion engine. The object of the method disclosed there is that the pinion should be engaged in the ring gear at essentially the same peripheral speed of both transmission parts. Comparable methods for the case of a regular starting process of an internal combustion engine, ie with a positive direction of rotation of the internal combustion engine, are for example from the DE 10 2005 004 326 A1 and the DE 10 2004 017 496 A1 known.

In contrast, it is provided that the pinion is engaged in the ring gear of the starter device by deliberately and due to technical means that the starter pinion contacts the ring gear at a peripheral speed that is lower than the peripheral speed of the ring gear. This has the advantage that the engagement process of the pinion in the ring gear can take place as in the conventional case of the engagement of a pinion of an ordinary starter in the ring gear. The conventional engagement process causes relatively little wear under normal conditions, which is particularly desirable in a vehicle with a start-stop system. For example, in a vehicle with a start-stop system, the number of starts is up to ten times higher than in vehicles with a conventional start system. Against this background, it is particularly desirable to enable low-wear engagement in a start-stop system.

Disclosure of the invention benefits

The method according to the invention with the features of the main claim has the advantage that when a starter pinion is engaged in the ring gear of an internal combustion engine, there are speed conditions which lead to a relatively gentle, ie. H. wear-free engagement of a pinion in the ring gear is made possible.

It can be provided that the peripheral speed of the ring gear is not equal to zero when the starter pinion contacts the ring gear at a peripheral speed. In particular in the event that the starter pinion is actively rotated to engage, it is provided that the peripheral speed of the starter pinion is not equal to zero in order to achieve the particular intended kinematic and kinetic conditions.

The method is particularly reliable if the peripheral speeds of the ring gear and the pinion gear are oriented in the same direction at their common point of engagement. For example, in the case that the toothed ring and also the starter pinion are each designed as externally toothed spur gears, this means that they move in opposite directions of rotation.

With regard to the different circumferential speeds of the ring gear and starter pinion, extensive tests have shown that special conditions should apply with regard to the circumferential speeds. It is provided that the circumferential speed of the ring gear at the moment of first contact with the starter pinion or the contacting of the starter pinion with the ring gear, the circumferential speed of the ring gear formed by a maximum of the product of 5 meters per second per millimeter and the module of the ring gear is larger in millimeters and slightly larger than the peripheral speed of the pinion. The reliability of the method can be increased in that the starting device has a pinion shaft which drives the starter pinion, a spring force of a spring element acting between the starter pinion and the pinion shaft in the direction of its axis of rotation, the spring element being compressed by contacting the starter pinion with the ring gear , The reliability of the system is not only improved by the resilient or elastic properties, but at the same time by the associated damping processes, which arise, for example, from the friction of the spring with its counter bearings or any flow damping.

For the method, it is also important that the starter pinion is advanced to the ring gear in good time and also achieves a high peripheral speed as intended. Accordingly, it is important that a switching criterion is recognized by a control device and the starter pinion is then advanced in one step towards the ring gear and in another step is rotated, the circumferential speed prevailing on the pinion being less than the circumferential speed when the ring gear is reached Sprocket is. These measures can ensure that the pinion contacts the ring gear at the right moment with a suitable property. It is irrelevant which switching criterion is used here. It is also irrelevant which control unit recognizes the switching criterion.

For example, the switching criterion can be a signal that corresponds to a request to switch off the internal combustion engine. The desire to switch off the internal combustion engine may be due, for example, to the fact that the speed of the vehicle is, for example, zero and / or the drive train is open, or the vehicle speed is, for example, below a low speed threshold, for example <7 h / km. Another switching criterion can be, for example, a signal which corresponds to a speed characteristic of the ring gear of the internal combustion engine. A speed characteristic of the ring gear would here, for example, be the angular speed of the ring gear or the change in the angular speed of the ring gear, for example below a certain speed threshold, from which a coming standstill of the internal combustion engine can be derived. Such a property could indicate that the internal combustion engine should be switched off (e.g. automatic flywheel system). It is provided that, based on the switching criterion, a point in time is calculated and the starting device is also activated. For example, For example, it can be defined that in the event that the internal combustion engine reaches a speed below 600 rpm, the starting device is activated (rotation of the starter pinion, toe-in of the starter pinion) in order to have the starter pinion with the suitable property with the ring gear at a suitable time to contact.

With regard to the method, provision is made in particular for the starter pinion to be set in rotation in one step and then to be preloaded to the ring gear in one step.

drawings

Figur 1

eine Startvorrichtung und ausschnittweise eine Brennkraftmaschine mit Zahnkranz,

Figur 2

eine Prinzipdarstellung des Systems aus Brennkraftmaschine, Startvorrichtung und Steuergeräten in einem ersten Ausführungsbeispiel,

Figur 3

eine Prinzipdarstellung der Geschwindigkeitsverhältnisse zum Zeitpunkt des ersten Kontaktierens des Andrehritzels am Zahnkranz,

Figur 4

zeigt den Ablauf eines theoretischen Verfahrens anhand von einigen Momentaufnahmen von Situationen während des Verfahrenablaufs bis zum Andrehen,

In the drawings is a method for engaging a pinion gear in a ring gear. shown. Show it:

Figure 1

a starting device and sections of an internal combustion engine with ring gear,

Figure 2

1 shows a basic illustration of the system comprising the internal combustion engine, starting device and control units in a first exemplary embodiment,

Figure 3

a schematic representation of the speed relationships at the time of first contacting the pinion on the ring gear,

Figure 4

shows the course of a theoretical procedure based on a few snapshots of situations during the course of the procedure until turning on,

Embodiments of the invention

Figure 1 shows an electrical machine 10 (starting device) in a longitudinal section. This electrical machine 10 has, for example, an electric motor 13 (starter motor) and a pushing device 16. The electric motor 13 and the thrust device 16 are fastened to a common drive end shield 19. Functionally, the electric motor 13 is used, for example, to drive a starter pinion 22 when it is engaged in the ring gear 25 of the internal combustion engine (not shown here).

The electric motor 13 has, as a housing 11, a pole tube 28 which carries pole shoes 31 on its inner circumference, each of which is wound by an excitation coil 300, which is part of an excitation winding 34. The pole shoes 31 in turn surround an armature 37, which has an armature package 43 constructed from lamellae 40 and an armature winding 49 arranged in slots 46. The armature package 43 is pressed onto a drive shaft 44. At the end of the drive shaft 44 facing away from the starter pinion 22, a commutator 52 is also attached, which is constructed, among other things, from individual commutator segments 55. The commutator segments 55 are electrically connected to the armature winding 49 in a known manner such that when the commutator segments 55 are energized by carbon brushes 58 results in a rotary movement of the armature 37 in the pole tube 28. A power supply 61 supplies both the carbon brushes 58 and the excitation winding 34 with current in the switched-on state. The drive shaft 44 is supported on the commutator side with a shaft journal 64 in a slide bearing 67, which in turn is held stationary in a commutator bearing cover 70. The commutator cover 70 in turn is fastened to the drive end shield 19 by means of tie rods 73 which are arranged distributed over the circumference of the pole tube 28 (screws, for example two, three or four pieces). The pole tube 28 is supported on the drive end shield 19 and the commutator bearing cover 70 on the pole tube 28.

A so-called sun gear 80, which is part of a planetary gear 83, adjoins the armature 37 in the drive direction. The sun gear 80 is surrounded by a plurality of planet gears 86, usually three planet gears 86, which are supported on axle journals 92 by means of roller bearings 89. The planet gears 86 roll in a ring gear 95 which is mounted in the pole tube 28. A planet carrier 98, in which the axle journals 92 are received, adjoins the planet wheels 86 in the direction of the driven side. The planet carrier 98 is in turn stored in an intermediate bearing 101 and a slide bearing 104 arranged therein. The intermediate bearing 101 is designed in a cup-shaped manner such that both the planet carrier 98 and the planet gears 86 are accommodated in it. Furthermore, the ring gear 95 is arranged in the pot-shaped intermediate bearing 101 and is ultimately closed by a cover 107 with respect to the armature 37. The intermediate bearing 101 is also supported with its outer circumference on the inside of the pole tube 28. The armature 37 has a further shaft journal 110 on the end of the drive shaft 44 facing away from the commutator 52, which is also received in a slide bearing 113. The plain bearing 113 in turn is received in a central bore of the planet carrier 98. The planet carrier 98 is integrally connected to an output shaft 116. This output shaft is supported with its end 119 facing away from the intermediate bearing 101 in a further bearing 122 which is fastened in the drive end shield 19. The output shaft 116 is divided into different sections: the section which is arranged in the slide bearing 104 of the intermediate bearing 101 is followed by a section with a so-called straight toothing 125 (internal toothing) which is part of a so-called shaft-hub connection. In this case, this shaft-hub connection 128 enables a driver 131 to slide axially in a straight line. This driver 131 is a sleeve-like extension, which is integrally connected here, for example, to a cup-shaped outer ring 132 of the freewheel 137. This freewheel 137 (directional lock) also consists of the inner ring 140, which is arranged radially inside the outer ring 132. Clamping bodies 138 are arranged between the inner ring 140 and the outer ring 132. This clamp body 138 prevent interaction with the inner and outer rings a relative rotation between the outer ring and the inner ring in a second direction. In other words: the freewheel 137 enables a circumferential relative movement between the inner ring 140 and outer ring 134 only in one direction. In this exemplary embodiment, the inner ring 140 is made in one piece with the starter pinion 22 and its toothing 143.

The single-track mechanism is discussed below. The pushing device 16 has a housing 156 which is fastened to the drive end shield 19 by means of a plurality of fastening elements 159 (screws). A winding 162 for retraction is also arranged in the pushing device 16. When pulled in, the winding 162 causes an electromagnetic field which flows through various components. Among other things, this magnetic field affects a linearly movable armature, which is referred to here as lifting means 168, and possibly a yoke core 171, which is lid-like here. The lifting device 168 carries a push rod 174 which is moved to the right when the lifting device 168 is drawn in linearly.

The pushing device 16 or the lifting means 168 has the task of using a pulling element 187 to move a lever 190 arranged in the drive bearing plate 19 so as to be rotatable. This lever 190, usually designed as a fork lever, grips with two “tines” or fork arms (not shown here) on its outer circumference a driving ring 197 located between two disks 193 and 194 in order to move it towards the freewheel 137 against the resistance of the spring 200 and thereby engage the starter pinion 22 in the ring gear 25.

Alternatively, the electric motor 13 could also be permanently magnetically excited. In this case, the pole tube 28 has permanent magnets on its inner circumference instead of pole shoes 31, each surrounded by an excitation coil 300, which ensure the corresponding magnetic opposing field to the armature 37.

In Figure 2 shows how the starting device 10 is electrically connected or connected to a starter control unit 250. For example, this starter control unit 250 uses an electrical solenoid 253 (relay) to actuate a switch 256, which is responsible for the power supply to the starter motor 13. If this switch 256 is closed, positive electrical potential is applied to the starter motor 13 by a starter battery or starter accumulator 259. As a result, the armature 37 begins to rotate, and the starter pinion 22 also begins to rotate. The starter control unit also switches 250 the pusher 16. For this purpose, the winding 162 is energized by means of two electrical lines 262 and 265 for drawing in. As a result, the lifting means 168 moves, which moves the pulling element 187 and subsequently the lever 190. The starter pinion 22 is thus advanced axially in the direction of the output shaft 116 in the direction of the ring gear 25.

The sequence according to the embodiment Figure 2 is as follows: A speed sensor 270 transmits a signal to an engine control unit 273. This signal corresponds to a speed characteristic of the ring gear 25 of the internal combustion engine 20. It is irrelevant whether the speed sensor 270 is the speed of the ring gear 25 or the speed of another with the Sprocket 25 connected component transmitted. The speed of a camshaft of the internal combustion engine 20 could also come into question here, for example. In the embodiment according to Figure 2 The engine control unit 273 decides whether the starter control unit 250 should be activated or not. If the speed characteristic is such that the starter pinion 22 is to be engaged in the ring gear 25, in this case the engine control unit 273 activates the starter control unit 250, which both starts the starter motor 13 (activating the solenoid 253, closing the switch 256) and activating it of the pushing device 16 by switching the winding 162. There are alternatives to this activation procedure, which will be mentioned below. According to the method described above, a method for engaging a starter pinion 22 of a starting device 10 into a ring gear 25 of an internal combustion engine is provided, the starter pinion 22 having a circumferential speed v _R due to a rotating starter motor 13 and the ring gear 25 having a circumferential speed v _ZK , the Starting pinion 22 axially pre-tracks along a rotation axis 276. The starter pinion 22 contacts the ring gear 25 at a peripheral speed v _R that is less than the peripheral speed v _{ZK of} the ring gear 25.

The Figure 3 shows a schematic view in the axial direction (axis of rotation of starter pinion 22 and ring gear 25) an end view of the starter pinion 22 and the ring gear 25 at the moment before the ring gear 25 is contacted by the starter pinion 22. It is shown that the ring gear 25 is clockwise here and the starter pinion 22 counterclockwise. The ring gear 25 has a circumferential speed v _ZK on its outer circumference, ie here on the pitch circle diameter, and the starter pinion 22 has a circumferential speed V _R on its pitch circle diameter. As shown, the starter pinion 22 contacts the ring gear 25 at a peripheral speed v _R , the peripheral speed v _{R being} less than the peripheral speed v _{ZK of} the ring gear 25.

The Figure 4a to 4k shows the sequence of the Einspurvorgangs in a highly schematic manner. The representations in Figure 4a to 4k show in developments the process of the engagement of the teeth of the starter pinion 22 in the tooth gaps of the ring gear 25. That is. the circumference of the gears is shown linear here.

So shows Figure 4a the situation of the starter pinion 22 and the ring gear 25 after the starter pinion 22 has been rotated. The starter pinion 22 shows a tooth ZR1 in the detail and subsequently a tooth ZR2. These teeth ZR1 and ZR2 have a bevel 303 in the direction of the end face 300 directed towards the ring gear 25, this bevel 303 has the back of the teeth. Back side here means that this bevel passes from the front side 300 to the back of the tooth, the back of the tooth ZR1 or ZR2 being oriented against the direction of rotation. The ring gear 25 also has an end face 306. The teeth ZK1, ZK2, ZK3 and ZK4, representative of all teeth on the outer circumference of the ring gear 25, also have a bevel 309. In contrast to the bevels 303 of the starter pinion 22, these bevels 309, starting from the end face 306 in the direction of the direction of rotation and thus the peripheral speed v _ZK . The bevels 303 of the starter pinion 22 and also the bevels 309 of the ring gear 25 are opposite one another or face one another. The different peripheral speeds of the pitch circle of the starter pinion 22 and the ring gear 25 are shown here with different sized arrows.

Starting from the Figure 4a show the Figure 4b the next step. The Figure 4b here shows the moment of contacting the pinion 22 on the ring gear 25. This Figure 4b shows the normal case of the first attempt to engage a pinion 22 in the ring gear 25 of an internal combustion engine, namely the so-called tooth-on-tooth position. As can be clearly seen here, the end faces 300 and 306 of teeth ZR1 and ZR2 and teeth ZK1 and ZK2 are in the way of one another. A smooth, unimpeded engagement of the pinion 22 in the ring gear 25 is not possible.

In accordance with the further course of the single-track method and the situation with regard to the peripheral speeds v _R and v _ZK of the starter pinion 22 and the ring gear 25, the two gear wheels rotate relative to one another. Accordingly, the teeth ZK1 and ZK2 of the ring gear 25 slide along the end faces of the teeth ZR1 and ZR2 until theoretically there would be the possibility for the teeth ZR1 and ZR2 to enter a tooth gap ZL1 between the teeth Engage teeth ZK1 and ZK2. Due to the inertia of the starter pinion 22 and the relative speed, ie the difference in the peripheral speeds of the starter pinion 22 and the ring gear 25, the teeth ZR1 and ZR2 initially fail to mesh into the corresponding tooth gaps ZL1 and ZL2 of the ring gear 25. Rather, the bevels 303 of the teeth ZR1 and ZR2 abut the bevels 309 of the teeth ZK2 and ZK3. This impact or impact leads to the starter pinion 22 initially bouncing off the bevels 309, but losing kinetic energy in the process, ie not too far back in the axial direction (axis of rotation 276), see also Figure 4e , During this ricocheting and not being engaged in the ring gear 25, the ring gear 25 continues to rotate relative to the starter pinion 22, so that the bevels of the teeth 303 ZR1 and ZR2 now face the bevels 309 of the teeth ZK3 and ZK4, see also Figure 4g , Due to the fact that the starter pinion now carries less kinetic energy, the teeth of the starter pinion 22 no longer hit the bevels 309 of the teeth ZK3 and ZK4 of the ring gear 25 quite as hard. Furthermore, the ring gear 25 with the impact ( Figure 4d ) of the starter pinion 22 to the starter pinion 22 transmit a certain angular momentum (at the same time, however, the toothed ring was also braked somewhat), so that the starter pinion 22 with its teeth ZR1 and ZR2 now does not or almost not rebound from the bevels 309 of the teeth ZK3 and ZK4 and is pushed further into the tooth gaps ZL2 and ZL3 due to a prestressing force of the spring 200 until they have left the bevels 309 of the ring gear 25 behind them ( Figure 4h ).

The teeth ZR1 and ZR2 of the starter pinion 22 now slide, driven in the circumferential direction through the ring gear or its teeth ZK3 and ZK4, further into the tooth gaps ZL3 and ZL2 until these teeth are completely inserted into the tooth gaps ZL2 and ZL3 ( Figure 4i and Figure 4j ). The teeth ZR3 and ZR4 then carry out a change of contact ( Figure 4k ) by, ie either the gear rim 25 brakes so strongly that the teeth ZK3 and ZK4 slow down and come to rest against the teeth ZR1 and ZR2 or that the pinion gear 22 accelerates so much that it now drives the gear rim 25 actively to turn the engine 20 back over the ring gear 25 (continued operation of the engine). The latter case can occur if the driver has changed his intentions while the engagement of the pinion gear 22 in the ring gear 25 was in progress. Such a change can occur, for example, when the driver has approached a traffic light with his vehicle and intended to bring the vehicle to a standstill or has brought it to a very short standstill. In such a case, the internal combustion engine can just in the concept of Be run out when the traffic light switches from "stop" to "drive". In such a case, the starting pinion 22 can be suddenly accelerated, for example, by actuating a signal transmitter which represents a driver's request (accelerator pedal) and the Figure 4k presented situation occur (keyword "mind change", reinterpretation for change of intent or change of mind of the driver).

1. a) Der erste Fall ist der Fall, wie er in Figur 3 dargestellt ist. Die Umfangsgeschwindigkeit des Zahnkranzes v_ZK ist größer als die Umfangsgeschwindigkeit v_R des Andrehritzels 22. Daraus ergibt sich im Umkehrschluss, dass das Andrehritzel 22 mit einer Umfangsgeschwindigkeit v_R den Zahnkranz 25 kontaktiert, die kleiner als die Umfangsgeschwindigkeit v_ZK des Zahnkranzes 25 ist. Die Drehrichtung ist in diesem Fall in der gleichen Richtung wie die vorgesehene bzw. tatsächliche Drehrichtung einer Antriebswelle 21 (beispielsweise Kurbelwelle) der Brennkraftmaschine 20 im antreibenden Fall und hier wertmäßig als positiv bewertet. In diesem Fall ist die Umfangsgeschwindigkeit v_ZK des Zahnkranzes 25 ungleich Null. Ebenso ist die Umfangsgeschwindigkeit v_R des Andrehritzels 22 ungleich Null. Beide Umfangsgeschwindigkeiten v_R, v_ZK sind in gleicher Richtung orientiert, Figur 3.
2. b) In diesem Fall ist die Umfangsgeschwindigkeit v_ZK des Zahnkranzes 25 nach wie vor größer als die Geschwindigkeit v_R des Andrehritzels 22. Dies bedeutet, dass die Drehrichtung des Andrehritzels 22 in diesem Fall der Andrehrichtung des Andrehritzels 22 aus dem Fall a entgegengesetzt ist. Während im Fall a das Andrehritzel 22 mit einer Drehung bzw. Winkelgeschwindigkeit dreht, die der vorgesehenen Drehung der Antriebswelle 21 in deren Antriebszustand entgegengesetzt ist, so ist im Fall b vor dem Kontaktieren des Andrehritzels 22 dessen Winkelgeschwindigkeit in der gleichen Richtung wie die spätere Winkelgeschwindigkeit der Antriebswelle 21. Unter derartigen Geschwindigkeitsverhältnissen zwischen dem Zahnkranz 25 und dem Andrehritzel 22 können die gleichen Relativbewegungen vorliegen wie im Fall a. Im Unterschied zum Fall a, ist nach dem erfolgten Einspuren des Andrehritzels 22 die Drehrichtung und damit die Winkelgeschwindigkeit des Startermotors 13 umzudrehen.
3. c) Beim Fall c ist die Umfangsgeschwindigkeit v_ZK des Zahnkranzes 25 größer Null und die Umfangsgeschwindigkeit v_R des Andrehritzels 22 kleiner als die Umfangsgeschwindigkeit v_ZK des Zahnkranzes 25. Die Winkelgeschwindigkeit des Zahnkranzes 25 ist dabei der Antriebsdrehrichtung der Antriebswelle 21 entgegengesetzt. Ein derartiger Fall kann dann auftreten, wenn sich in der Brennkraftmaschine 20 aufgrund von bekannten Auslaufeigenschaften die Drehrichtung der Antriebswelle 21 umkehrt. So ist das Phänomen bekannt, dass ein sich in einer Brennkraftmaschine zum sogenannten oberen Totpunkt bewegender Kolben die für die Verbrennung vorgesehene Luft verdichtet und dabei Arbeit gegen den Luftdruck in dem Brennraum oberhalb des Kolbens verrichtet. Ist die Energie des Kolbens bzw. der Antriebswelle 21 und der damit verbundenen Antriebsteile (Kolben, Pleuel, Kurbelwelle) nicht so hoch, dass der Kolben den oberen Todpunkt überschreiten kann, so wird die Antriebswelle 21 wieder zurückdrehen. Dieser Fall ist hier mit diesem Fall c gemeint. In einer derartigen Situation dreht sich die Antriebswelle 21 nachdem sie den oberen Todpunkt nicht erreicht hat, wieder zurück und weist demzufolge kurzfristig eine Winkelgeschwindigkeit auf, die der Winkelgeschwindigkeit im Antriebsfall und auch im Fall a entgegengesetzt ist. Derartige Details zu diesem Thema sind aus druckschriftlichen Werken zur Technik von Verbrennungsmotoren allgemein bekannt. Im Moment ab der Drehrichtungsumkehr und damit der Annahme einer Winkelgeschwindigkeit der Antriebswelle 21 und des Zahnkranzes 25, wird diese Winkelgeschwindigkeit und damit auch die Umfangsgeschwindigkeit des Zahnkranzes 25 dem Wert nach negativ bewertet. Mit anderen Worten, die Winkelgeschwindigkeit des Andrehritzels 22 muss bis zum Moment des Kontaktierens einen Wert annehmen, der verglichen mit der Winkelgeschwindigkeit des Zahnkranzes 25 noch negativer ist, um gemäß der hier vorgenommenen Definition kleiner zu sein als die Winkelgeschwindigkeit des Zahnkranzes 25. Gemäß der hier vorgenommenen Definition ist in diesem Fall die Umfangsgeschwindigkeit v_R des Andrehritzels 22 ebenfalls kleiner als die Umfangsgeschwindigkeit v_ZK des Zahnkranzes 25.

According to what has been described so far, a method is therefore provided for engaging a starter pinion 22 of a starting device 10 into a ring gear 25 of an internal combustion engine 20, the pinion gear 22 having a peripheral speed v _R and the ring gear 25 having a peripheral speed v _ZK , the starter pinion 22 along axially forward of its axis of rotation 276, the starter pinion 22 making contact with the ring gear 25 at a peripheral speed v _R which is lower than the peripheral speed v _{ZK of} the ring gear 25. It is clear from this that the speed relationships between the starter pinion 22 and the ring gear 25 are important in the method. Accordingly, several cases can be distinguished, only case c) corresponding to the claims appended here and describing a method according to the invention:

1. a) The first case is the case as in Figure 3 is shown. The peripheral speed of the ring gear v _ZK is greater than the peripheral speed v _{R of} the starter pinion 22. Conversely, this means that the starter pinion 22 contacts the ring gear 25 with a peripheral speed v _R that is lower than the peripheral speed v _{ZK of} the ring gear 25. In this case, the direction of rotation is in the same direction as the intended or actual direction of rotation of a drive shaft 21 (for example crankshaft) of the internal combustion engine 20 in the driving case, and here in terms of value it is rated positive. In this case, the peripheral speed v _{ZK of} the ring gear 25 is not equal to zero. Likewise, the peripheral speed v _{R of} the pinion gear 22 is not equal to zero. Both peripheral speeds v _R , v _ZK are oriented in the same direction, Figure 3 ,
2. b) In this case, the circumferential speed v _ZK of the ring gear 25 is still greater than the speed v _{R of} the pinion gear 22. This means that the direction of rotation of the pinion gear 22 in this case is opposite to the direction of rotation of the pinion gear 22 from case a. While in case a the starter pinion 22 rotates at a rotation or angular speed which is opposite to the intended rotation of the drive shaft 21 in its drive state, in case b before contacting the starter pinion 22 its angular velocity is in the same direction as the later angular velocity Drive shaft 21. Under such speed conditions between the ring gear 25 and the starter pinion 22 there can be the same relative movements as in case a. In contrast to case a, after the starter pinion 22 has been engaged, the direction of rotation and thus the angular velocity of the starter motor 13 must be reversed.
3. c) In case c, the peripheral speed v _ZK of the ring gear 25 is greater than zero and the peripheral speed v _{R of} the starter pinion 22 is smaller than the peripheral speed v _ZK of the ring gear 25. The angular speed of the ring gear 25 is opposite to the direction of rotation of the drive shaft 21. Such a case can occur when the direction of rotation of the drive shaft 21 is reversed in the internal combustion engine 20 due to known run-down properties. Thus, the phenomenon is known that a piston moving in an internal combustion engine to the so-called top dead center compresses the air provided for the combustion and thereby does work against the air pressure in the combustion chamber above the piston. If the energy of the piston or the drive shaft 21 and the associated drive parts (piston, connecting rod, crankshaft) is not so high that the piston can exceed the top dead center, the drive shaft 21 will turn back again. This case is meant here with this case c. In such a situation, the drive shaft 21 rotates back after it has not reached the top dead center and consequently has an angular velocity for a short time which is opposite to the angular velocity in the drive case and also in case a. Such details on this topic are generally known from printed works on the technology of internal combustion engines. At the moment from the reversal of the direction of rotation and thus the assumption of an angular speed of the drive shaft 21 and the ring gear 25, this angular speed and thus also the peripheral speed of the ring gear 25 is evaluated negatively in terms of value. In other words, the angular velocity of the starter pinion 22 must, until the moment of contacting, assume a value which is even more negative compared to the angular velocity of the ring gear 25 in order to be smaller than the angular velocity of the ring gear 25 according to the definition made here In this case, the definition made is the peripheral speed v _{R of} the starter pinion 22 also smaller than the peripheral speed v _ZK of the ring gear 25.

In this method it is provided that the circumferential velocity v _ZK of the ring gear 25 a maximum at the moment of first contacting a value formed from the product of 5m / (s ^* mm) [five yards per the product of seconds and millimeters], and the module m _{ZK of} the ring gear 25 is larger in mm and slightly larger than the peripheral speed v _{R of} the pinion gear 22 is. As an example, a value of 2.11 mm is assumed for the module m _{ZK of} the ring gear 25. This technical size module m is specified, for example, in the German industrial standard DIN 868 and is a basic size for length dimensions of gears. The module m results as the quotient of the division p and the number π. The pitch p is in turn in a certain section of the toothing of the arches on the reference surface between the flanks of the same name of two adjacent teeth, that is to say, for example, the teeth ZK1 and ZK2. If the module m has the stated value, it is provided that the peripheral speed v _{ZK of} the ring gear 25 is at most 10.55 meters per second greater than the peripheral speed v _{R of} the starter pinion 22. For a module m of 3 mm, this would result thus a value of 15 meters per second and for a module of 1.5 mm a speed of 7.5 meters per second.

It is further provided that the starting device 10 has a pinion shaft in the form of the driver 131, which drives the starter pinion 22. A spring force of the spring 200 acts on the starter pinion 22, the spring 200 being compressed when the starter pinion 22 contacts the ring gear 25.

In reference to Figure 2 it has already been explained that a switching criterion, e.g. B. a speed of the ring gear 25 or the drive shaft 21 or a camshaft by a control unit 273, executed there is recognized as an engine control unit. As a result, the starter pinion 22 is pre-tracked in one direction towards the ring gear 25 and set in rotation in another step, the peripheral speed v _R prevailing on the pinion gear 22 being smaller than the peripheral speed v _ZK when the ring gear 25 is reached. It is initially irrelevant whether the toe-in of the starter pinion 22 takes place before the start of the rotation or in the reverse order.

A variant of the embodiment according to Figure 2 can provide, for example, that the switching criterion, for example the rotational speed, is not recognized by the control unit 273 of the internal combustion engine 20, but rather, for example, by the control unit 250 of the starter, which then initiates the steps already mentioned (rotating, toe-in).

The switching criterion can be, for example, a signal that corresponds to a request for switching off the internal combustion engine in general. Such a request can already appear, for example, in that the speed of the Vehicle should be reduced. Such a reduction in speed can result, for example, from the actuation of the brake pedal or the actuation of a corresponding signal sensor, which processes the signals of the brake system. A corresponding other signal could also be the signal which is intended to signal the internal combustion engine 20 that it should now be controlled in idle mode (overrun cutoff).

Thus, according to the method or a variant of this method, a time is calculated based on the switching criterion and the starting device is also activated in order to achieve the conditions desired according to the invention. It is envisaged that the method is applied to an internal combustion engine 20 that is running out, the rotational speed of the drive shaft 21 being reduced. According to a further method step, it is provided that the rotational speed of the starter pinion 22 is reduced to the value zero after engagement in the ring gear 25. As a result, this condition also applies to the ring gear 25.

Within the scope of the method it is provided that the starter motor 13 and the lifting means 16 are controlled separately from one another.

The spring 200 can be designed, for example, as a spiral spring or as a plate spring or another type of spring.

Claims (11)

1. A method for tracking a starting pinion (22) of a starting device (10) into a gear rim (25) of an internal combustion engine (20) which has a drive shaft (21), wherein the starting pinion (22) has a circumferential speed (v_R) and the gear rim (25) has a circumferential speed (v_ZK),
   wherein an angular velocity and the circumferential speed (v_ZK) of the gear rim (25) are evaluated as positive when the angular velocity is in the same direction as the intended direction of rotation of the drive shaft (21) in the driving case, and are evaluated as negative when the angular velocity is opposite to the intended direction of rotation of the drive shaft (21) in the driving case,
   wherein the starting pinion (22) axially advances along its axis of rotation (276) and the starting pinion (22) contacts the gear rim (25) at a circumferential speed (v_R) smaller than the circumferential speed (v_ZK) of the gear rim (25),
   characterized in that the angular velocity of the gear rim (25) is opposite to the intended direction of rotation of the drive shaft (21) in the driving case and thus the angular velocity and the circumferential speed (v_ZK) of the gear rim are evaluated negatively according to the value, and
   in that the angular speed of the starting pinion (22) is even more negative compared with the angular speed of the gear rim (25).
2. The method according to any one of the above claims, characterized in that the circumferential speed (v_ZK) of the gear rim (25) at the moment of the first contacting is at most by a value formed by the product of 5 metres per second per millimetre and the module m of the gear rim (25) in millimetres greater and minimally greater than the circumferential speed (v_R) of the starting pinion (22).
3. The method according to any one of the above claims, characterized in that the starting device (10) has a pinion shaft which drives the starting pinion (22), a spring force of a spring (200) acting on the starting pinion (22), the spring (200) being compressed when the starting pinion (22) contacts the gear rim (25).
4. The method according to any one of the above claims, characterized in that a switching criterion is recognized by a control device (273, 250) and the starting pinion (22) in one step advances in the direction of the gear rim (25) and in another step is set in rotation, the circumferential speed (v_R) prevailing on the starting pinion (22) when the gear rim (25) is reached being smaller than the circumferential speed (v_ZK) of the gear rim (25).
5. The method according to claim 4, characterized in that the switching criterion is a signal which corresponds to a wish to switch off the internal combustion engine (20).
6. The method according to claim 4 or 5, characterized in that a time is calculated on the basis of the switching criterion, in which the starting device (10) is activated.
7. The method according to any one of claims 4 to 6, characterized in that first the starting pinion (22) is set in rotation in one step and then in one step it is advanced to the gear rim (25).
8. The method according to any one of the above claims, characterized in that a rotational speed of the gear rim (25) is substantially reduced.
9. The method according to any one of the above claims, characterized in that the starter motor (13) and the lifting means (16) are controlled separately from one another.
10. The method according to any one of the above claims, characterized in that the starting pinion (22) has teeth (ZR1, ZR2, ZR3) with end faces (300) and the gear rim (25) has teeth (ZK1, ZK2, ZK3, ZK4) with end faces (306), the teeth (ZR1, ZR2, ZK3, ZK4) have bevels (303) and the teeth (ZK1, ZK2, ZK3, ZK4) have bevels (309), the bevels (303) of the teeth (ZR1, ZR2, ZR3) of the starting pinion (22) and the bevels (309) of the teeth (ZK1, ZK2, ZK3, ZK4) of the gear rim (25) being opposite one another.
11. The method according to claim 10, characterized in that a so-called tooth-to-tooth position results in the first attempt at a tracking, then the teeth (ZK1, ZK2) of the gear rim (25) slide along the end faces (300) of the teeth (ZR1, ZR2) of the starting pinion (22) until the teeth (ZR1, ZR2) of the starting pinion (22) theoretically have the possibility of being inserted into a tooth gap (ZL1) between the teeth (ZK1, ZR2), ZK2) of the gear rim (25), then the bevels (303) of the teeth (ZR1, ZR2) of the starting pinion (22) strike the bevels (309) of the teeth (ZK2, ZK3) of the gear rim (25) and the starting pinion (22) first bounces off the bevels (309), loses kinetic energy in the process and advances back in the direction of the rotation axis (276), the gear rim (25) continues to rotate relative to the starting pinion (22), so that the bevels (303) of the teeth (ZR1, ZR2) of the starting pinion (22) are now opposite the bevels (309) of the teeth (ZK3, ZK4) of the gear rim (25), wherein the teeth (ZR1, ZR2) of the starting pinion (22) are in the same position as the bevels (309) of the teeth (ZK3, ZK4) of the gear rim (25),wherein the teeth (ZR1, ZR2) of the starting pinion (22) do no longer strike as hard as before the bevels (309) of the teeth (ZK3, ZK4) of the gear rim (25), the gear rim (25) transmits a certain angular momentum with the impact of the starting pinion (22) on the starting pinion (22), so that the starting pinion (22) with its teeth (ZR1, ZR2) now does not bounce off the bevels (309) of the teeth (ZK3, ZK4), or almost does not bounce off them, and the starting pinion (22) is pushed further into the tooth gaps (ZL2, ZL3) on the basis of a pretensioning force of a spring (200) until these have left the bevels (309) of the gear rim (25) behind them.

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