EP2297450A1

EP2297450A1 - Starter for an internal combustion engine

Info

Publication number: EP2297450A1
Application number: EP09745679A
Authority: EP
Inventors: Thomas Biessenberger; Hartmut Wanner; Uwe Daurer; Oliver Neumann
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2008-05-14
Filing date: 2009-05-06
Publication date: 2011-03-23
Also published as: CN102089514A; WO2009138346A1; JP2011521141A; US20110115238A1; JP2013127253A; DE102008001750A1; US8610297B2

Abstract

The invention relates to a starter (10) for an internal combustion engine, comprising a starter motor (12) which can be coupled to the internal combustion engine by means of a pinion (22), and a device for engaging the pinion (22) in a gear rim (26) of the internal combustion engine and connecting the starter motor (12) to a DC voltage supply system (30, 31). In order to disconnect the sequence of operations, the device has separate means, in particular separate relays (57, 64; 60), for engaging the pinion (22) on one hand and turning on the starter motor on the other when the internal combustion engine is started, thus preventing reactions of the engagement dynamics on the contact system when the motor current is switched.

Description

description

title

Starter for an internal combustion engine

State of the art

The invention relates to a starter for an internal combustion engine according to the preamble of the independent claim. Such a starter is described for example in the Automotive Handbook of Bosch, 25 Aufläge, p.986 in the embodiment as a thrust screwdriver starter, which is controlled by a so-called engagement relay. This relay takes over the functions indenting, ie meshing of the pinion of the starter motor in the ring gear of an internal combustion engine, and switching the main current of the starter motor. When meshing the pinion with the sprocket, two possible sequences are to be distinguished: In about 20% - 30% of the gears, one pinion of the pinion hits a gap in the ring gear, while in about 70% - 80% of the gears meshing with one tooth of the pinion Pinion meets a tooth of the ring gear and the meshing must be supported by a Einspurfeder. Although this known starter design requires only a single relay and can thus be produced relatively inexpensively, on the other hand arise for the switching operation of the high motor current at the switching contact, which connects the motor windings to the voltage source, very difficult working conditions. Especially in teilentladenen batteries and with increasing mechanical wear of the Einspurteile then the dynamics when switching the main starter current can reduce so much that weld by welding arcs occurring during switching the contacts. On the other hand, depending on the design of the starter with a tooth-gap initial position, the dynamics of the switching process and the consequent contact wear are possibly large when direct meshing of the pinion in the motor gear ring.

To improve the switch-on, especially in high-performance starters, it is known from the aforementioned reference to turn the motor current in two stages in so-called push-drive starters, in a first stage, the pinion of the starter is moved against the ring gear of the engine and at the same time Anchor of the starter motor is fed with a reduced current, so that the armature and with it the pinion rotate when meshing, thus facilitating the Einspurvorgang. The meshing mechanism is in this case provided with a pawl, which closes only at the end of the Einspurvorgangs the pinion another switching contact of the relay and via this the main circuit of the motor. This allows the Einspurvorgang and switching the main current of the engine in two separate

Operations take place, but the structure of the engagement relay is mechanically and electrically complex and prone to failure.

Disclosure of the invention

The starter according to the invention with the features of the independent claim has the advantage that the Operations of Einspurens the pinion on the one hand and the switching of the motor current on the other hand by the use of separate means for this, in particular by the use of separate relays are completely decoupled, the types of relay can be optimally adapted to the respective steps. For all or individual switching means, however, suitable semiconductor components can also be used for switching larger currents, preferably transistors or GTO (Gate Turn-Off) thyristors. This makes it possible, in particular, to completely disconnect the switching function for the high main engine current when starting the internal combustion engine from the meshing operation and thereby to avoid repercussions of the single track dynamics on the contact system of relays. The contact closing speed in this case is independent of the Einspursituation.

It is particularly advantageous if the switching relay is activated in the main circuit of the starter motor by the Einspurrelais even at the end or shortly before the end of the meshing movement and in this case the starter motor is connected directly to the voltage source. In this way, with little additional effort, an exact interaction between the meshing movement of the pinion and the switch-on of the main starter current at the end of

Einspurbewegung. Appropriately, the Einspurrelais this is equipped with a holding winding and a separate pull-in winding, which together actuate a switching contact for activating the switching relay. The holding winding and the Einspurwicklung preferably sit on the same relay core and are either switched in the same direction or in opposite directions. In the case of a co-directional interconnection, the necessary total flux with a smaller number of turns and / or reaches lower excitation current, while in opposite flooding the winding with the smaller flux can be used to dampen the switching process. Pay the turns and the excitation currents of the holding winding and the pull-in winding are suitably chosen so that the holding winding with a high number of turns and a sufficient excitation current causes the switching operation of the Einspurrelais, while the pull-in winding is equipped with a significantly lower number of turns, but a much higher Exciting current leads, which is sufficient to easily twist the anchor when meshing.

A particularly simple and inexpensive circuitry is obtained by a single-stage energization of the

Starter motor, wherein the pull-in winding of the Einspurrelais as a series resistor with a series winding of the starter motor is in series and both windings of the Einspurrelais together switch a normally open contact via which the winding of the switching relay energized and the

Starter motor is supplied with the full motor current at the end of the retraction movement of the Einspurrelais. Such an arrangement requires in a known manner a Einspurfeder, which supports in conjunction with a coarse thread, especially in a so-called tooth on tooth position of the pinion and the ring gear, the Einspurvorgang before the main current of the motor is suddenly turned on.

A particularly gentle Einspurvorgang is a basically known two-stage energization of

Starter motor achieved, wherein in a first switching stage, a limited Verdrehstrom for the starter armature via a normally closed contact and the pull-in winding of the Einspurrelais flows. Subsequently, in a second stage on or _ C _

energized shortly before the end of the retraction movement of the relay armature via a contact of the Einspurrelais the separate switching relay and fed the full motor current to the starter motor. Here, the two separate relay can be optimally designed according to the different requirements.

Further details and advantageous embodiments of the invention will become apparent from the dependent claims and the description of the embodiments, which are illustrated in the drawings and explained in more detail in the following description.

Show it

1 shows a schematic representation of a push-screw drive starter with a series winding,

2 shows a circuit diagram of a single-stage energized starter in conventional design,

Figure 3 is a circuit diagram of a single-stage energized starter in accordance with the invention

Execution,

4 shows a first circuit diagram of a two-stage energized starter according to the invention,

5 shows a second circuit diagram of a two-stage energized starter according to the invention, Figure 6 is a schematic representation of the spatial

Arrangement and interconnection of a starter according to the invention with Einspurrelais and switching relays and

Figure 7 is a schematic representation of the spatial

Arrangement and interconnection of a starter according to FIG. 6 with additional pilot control relay for energizing the Einspurrelais.

Embodiments of the invention

Figure 1 shows schematically the mechanical structure of the starter 10 according to the invention in the embodiment as a push-screw drive starter for an internal combustion engine. The starter 10 has a starter motor 12, the output shaft 14 has a coarse thread 16 which cooperates with a corresponding female thread in a driving shaft 18. Alternatively, the output shaft 14 is driven via an unillustrated, intermediate planetary gear. The Mitnehmerschaft 18 is fixedly connected to the outer ring of a freewheel ring 20, the inner ring carries a pinion 22. The pinion 22 and the freewheel 20 are mounted axially displaceably on the output shaft 14 up to a stop 24. The pinion 22 is thereby meshed in a ring gear 26 of an internal combustion engine, not shown. The axial displacement takes place with the aid of a relay arrangement 28 shown in detail in the following figures, which engages via a deflection lever 29 and a Einspurfeder 32 on the freewheel 20. As a voltage source 34 of the arrangement is a Battery, which is grounded with its negative terminal 31 and is connected with its positive pole 30 on the one hand directly and on the other hand via a Zündstandschalter 36 with the relay assembly 28. About the relay arrangement, a series winding 38 is fed, which is connected via brushes 40 and 42 and via the collector 44 of the motor to ground. The armature of the starter motor 12 is denoted by 46, its stator 48.

Figure 2 shows a circuit diagram of a single-stage energized starter in a conventional design. In this case, the positive pole 30 of the voltage source is connected on the one hand via the ignition start switch 36 and a connection 50 and on the other hand directly to an engagement relay 49. This includes a holding winding 52 and a

Feed winding 54 which have the same winding sense, are wound on the same core and both are connected with a winding end to the terminal 50. The other winding end of the holding winding 52 is connected to the negative pole 31 and to ground, the corresponding other winding end of the holding winding 54 is connected via the series winding 38 and the armature 46 of the starter motor 12 to the negative terminal 31 and to ground. Together, the holding coil and the pull-in winding actuate a normally open contact 56 of the engagement relay 49, via which the starter motor 12 is directly connected to the positive pole 30, as soon as the relay armature is fully or almost completely retracted and the pinion 22 is meshed with the ring gear 26.

The holding winding 52 and the pull-in winding 54 take over in this known arrangement together the work of the meshing of the pinion 22 in the ring gear 26 on the internal combustion engine and at the same time the function of switching the main current for the starter motor 12. Meets In this case, a tooth of the pinion 22 to a gap in the ring gear 26 so only a small force is necessary for meshing and the dynamics when switching the contact 56 is relatively large. On the other hand, the dynamics when switching the contact 56 is very low when a tooth of the pinion 22 strikes a tooth of the ring gear 26 when meshing, so that in addition the Einspurfeder 32 shown in Figure 1 must be clamped during engagement and for the actuation of the working contact 56th only little energy is available. As a result, relatively long arcing and welding can occur, which affect the function of the starter, at least in the longer term.

Figure 3 shows the circuit diagram of a single-stage energized starter in an embodiment according to the invention, with the above-described difficulties are solved. The circuit arrangement corresponds in terms of the structure with a Einspurrelais 57 and its connection to the DC voltage network 30, 31, in principle, that in Figure 2, but assumes in this arrangement the

Relay contact 56 not the switching function for the high motor current but only for the energization of the winding 58 of a switching relay 60, which then switches the motor current via its normally open contact 62. Also, this arrangement operates in one stage, wherein the pinion 22 as well as in the arrangement of Figure 2 meshed in the ring gear 26 and the motor current at the end or shortly before the end of the meshing movement of the pinion 22 is turned on in full. In contrast to the arrangement of Figure 2 is the Einspurrelais 57 in addition to the

Einspurarbeit for the pinion 22, however, demanded only the operation of the low-load contact 56 and made the actual switching of the motor current through the switching relay 60, so that the functions Einlen and switching are completely separated and the Einspurvorgang has no effect on the contact system of the switching relay 60.

Figure 4 shows a circuit arrangement for two-stage energization of a starter motor 12. Instead of the Einspurrelais 57 in Figure 3 for the single-stage energization occurs here a single track relay 64 with a normally closed contact 66 and a normally open contact 68. The hard terminals of the contacts 66 and 68 are parallel over a pilot control relay 70 connected to the positive pole 30, wherein the relay coil is connected to one end to the negative terminal 31 and to ground and with its other end via the terminal 50 and the ignition switch 36 to the positive pole 30 of the DC network. The holding winding 52 of the Einspurrelais 64 is also connected via the pilot control relay 70 to the positive terminal 30 and the negative pole 31 of the DC power grid.

In this embodiment, the two windings 52 and 54 of the Einspurrelais 64 opposite Wickelsinn, the holding winding 52 has a significantly higher number of turns than the pull-in winding 54 and is energized with a sufficiently large current to alone despite the opposite flow of the pull-in winding 54 Einspurvorgang of Ritzel 22 to accomplish. The pull-in winding 54 advantageously dampens the dynamics of the meshing movement and at the same time supplies a sufficiently high excitation current to the series winding 38 of the starter motor 12 in order to slightly turn it and facilitate or enable the meshing process. In this arrangement, a Einspurfeder additionally be used to assist the Einspurvorgangs. The energization of the starter motor 12 is again taken over independently of the function of the Einspurrelais 64 by the switching relay 60. For this purpose, the winding 58 of the switching relay 60 is energized at the end or near the end of the switching movement of the Einspurrelais 64 by the normally closed contact 66 and the normally closed contact 66 are opened, so that the switching relay 60 contact via its working 62 without interference from the meshing the starter motor 12th is supplied with its predetermined working current. By opening the normally closed contact 66, the pull-in winding 54 of the Einspurrelais 64 is de-energized, its holding winding 52 remains energized until the opening of the Zündstartschalters 36 and thus ensures the continuation of the boot process.

The use of a pilot control relay 70 is for the

Operation of the circuit arrangement according to Figure 4 is not mandatory, the Einspurrelais 64 can also be energized analogous to the circuit arrangement in Figure 3 directly via the ignition switch. On the other hand, the motor current in the first Bestromungsphase on the

Feeding winding 54 in the order of up to 200 A, so that at least for high-performance starter motors in the first stage of the energization of the use of a pilot control relay for bypassing the Zündstartschalters 36 is appropriate.

Figure 5 shows a variant of the circuit arrangement of Figure 4, which differs from the previously described embodiment in that the excitation current for the winding 58 of the switching relay 60 is not on the

Pilot relay 70 flows but is tapped directly from the supply line to the positive terminal 30 of the voltage source. Although this has the disadvantage that an additional interconnection between the Einspurrelais 64 and the switching relay 60th is required, on the other hand, however, the amount of current through the Einspurrelais 64 is reduced and the pilot control relay 70 can be omitted rather at least for smaller engine designs. All other functions of the circuit arrangement according to FIG. 5 correspond to those of FIG. 4 and need not be discussed again.

To explain the illustrations in FIGS. 6 and 7, additional connection points are designated by the reference symbols 50i, 50k, 50m and 50n in FIGS. Here, the connection point 5Oi is located at the fixed connection of the relay contact of the pilot control relay 70, the connection point 50k at the winding connection of the switching relay 60, the connection point 50m at one connection and the connection point 5On at the other connection of the make contact of

Einspurrelais 57, and 64. These reference numerals facilitate the interpretation of the illustrations in Figures 6 and 7, wherein in practice usually in the form of double contacts or with a contact plate switching contacts are also shown schematically.

Figure 6 shows the structural design of a starter according to the invention with single-stage energization according to Figure 3. Here, the starter motor 12, the Einspurrelais 57 and the switching relay 60 form a unit 72, either either relay 57 and 60 or one of them fixed in the housing of the starter motor 12 integrated, or are releasably connected to this. The internal structure of the Einspurrelais 57, the switching relay 60 and the starter motor 12 is symbolically denoted by the respective connection points. Thus, the Einspurrelais 57 receives its start signal via an external terminal of the ignition switch 36, whereby the normally open contact 56th closed and the connection points 50m and 50n are connected to each other to energize the relay.

In the switching relay 60 of the positive terminal 30 via the working contact 62 with the connection point 45 on the relay and this externally connected to the starter motor 12 and via its series winding 38 to the negative terminal 31, or to ground.

FIG. 7 shows the spatial arrangement of a two-stage energized starter according to the invention corresponding to FIGS. 4 or 5. In this case, the pilot control relay 70, the tracking relay 64, the switching relay 60 and the starter motor 12 form a structural unit 74. The relays 70, 64 and 60 are in turn selectively individual or integrated together in the housing of the starter motor 12 or detachably connected to it. The representation of the connection points and the contacts corresponds to Figures 4 and 5, which differ only by the power supply of the normally open contact 68 of the Einspurrelais 64. The connection 50n of the Einspurrelais 64 is selectively connected either to the connection point 5Oi on the pilot control relay 70 or directly to the positive pole 30 of the voltage source.

Claims

claims

1. starter for an internal combustion engine, with a starter motor (12) which is coupled via a pinion (22) with the internal combustion engine, and with a device for meshing the pinion (22) in a ring gear (26) of the internal combustion engine and for connecting the Starter motor (12) to a DC voltage network (30,31), characterized in that the device comprises separate means (57, 64; 60) on the one hand for the meshing of the pinion (22) and on the other hand for switching on the starter motor (12) at startup the internal combustion engine.

2. A starter according to claim 1, characterized in that the device has separate relays (57, 64, 60) on the one hand for the meshing of the pinion (22) and on the other hand for switching on the starter motor (12).

3. Starter according to claim 1 or 2, characterized in that by the Einspurrelais (57,54) at or shortly before the end of its switching movement, a switching relay (60) in

Main circuit of the starter motor (12) is activated and the starter motor is connected directly to the voltage source (30,31).

4. The starter according to one of the preceding claims, characterized in ¹ that the engaging relay (57,64) having a holding winding (52) and a pull-in winding (54), which together form a switching contact (56; 66, 68) for activating the switching relay ( 60).

5. Starter according to one of the preceding claims, characterized in that the Einspurrelais (57) has a normally open contact (56) for activating the switching relay (60) and for single-stage energization of the starter motor (12).

6. Starter according to one of claims 1 to 4, characterized in that the Einspurrelais (64) has a normally closed contact (66) and a normally open contact (68) for two-stage energization of the starter motor (12), wherein in a first stage, a limited motor current over the normally closed contact (66) and the pull-in winding (54) of the Einspurrelais (64) and in a second stage at or shortly before the end of Einspurbewegung the full motor current through the by the closed contact (68) of the Einspurrelais (64) operable switching relay (60 ) flows.

7. A starter according to claim 6, characterized in that in the first switching stage, a limited motor current over the

Normally closed contact (66) and the pull-in winding (54) of the Einspurrelais (64) and via a series winding (38) of the starter motor (12) flows.

8. Starter according to one of the preceding claims, characterized in that by the switching relay (60) a series winding (38) and the armature (46) of the starter motor (12) directly to the voltage source (30,31) are connected.

9. Starter according to one of the preceding claims, characterized in that the device as a switching means (57, 64, 60) comprises semiconductor switches.

10. Starter according to one of the preceding claims, characterized in that the Einspurrelais (64) is preceded by a pilot control relay (70).

11 starter according to claim 10, characterized in that the winding (58) of the switching relay (60) via a respective make contact of the pilot control relay (70) and the Einspurrelais (64) with the voltage source (30,31) is connectable.

12. A starter according to claim 10, characterized in that the winding (58) of the switching relay (60) via the normally open contact of the Einspurrelais (64) directly to it voltage source (30,31) is connectable.

13. Starter according to one of the preceding claims, characterized in that the holding winding (52) and the pull-in winding (54) of the Einspurrelais (64) opposite Wickelsinn, wherein the holding winding (52) provides the flooding for the ümschaltung the Einspurrelais (64) and the pull-in winding (54) dampens the switching process.

14. Starter according to one of the preceding claims, characterized in that the pilot control relay (70) and / or the

Einspurrelais (57,54) and / or the switching relay (60) form a structural unit (72,74) with the starter motor (12).

15. A starter according to claim 14, characterized in that the pilot control relay '(70) and / or the Einspurrelais (57,54) and / or the switching relay (60) releasably connected to the starter motor (12) are connectable.