WO2012110390A1

WO2012110390A1 - Circuit arrangement, method for operating the latter and starting apparatus

Info

Publication number: WO2012110390A1
Application number: PCT/EP2012/052189
Authority: WO
Inventors: Karl-Otto Schmidt
Original assignee: Robert Bosch Gmbh
Priority date: 2011-02-15
Filing date: 2012-02-09
Publication date: 2012-08-23
Also published as: CN103380290A; EP2676028A1; DE102011004156A1; HUE038271T2; CN103380290B; EP2676028B1

Abstract

The invention describes a circuit arrangement (1) for an electrical machine (2), in particular for a starting apparatus having a starter motor (2) for starting an internal combustion engine (15), in a motor vehicle, having a current-limiting apparatus (3) for limiting a starting current of the electrical machine (2), having a bridging apparatus (4) for bridging the current-limiting apparatus (3), wherein the bridging apparatus (4) can be directly connected to a high potential of a voltage source (10). In order to easily implement a stable circuit arrangement and a starting apparatus with a long service life, the bridging apparatus (4) comprises a contact opener and the contact opener is formed in a current path (83), with the result that the contact opener can be directly connected to a control switch (8) of the electrical machine (2).

Description

Description title

Circuit arrangement, method for operating it and starting device prior art

The invention relates to a circuit arrangement for an electrical machine, in particular for a starting device with a starter motor for starting an internal combustion engine, in a motor vehicle, with a current limiting device for limiting an inrush current of the electric

A machine comprising a lock-up device for bypassing the current-limiting device, wherein the lock-up device is directly switchable to a high potential of a voltage source. The invention further relates to a method for operating a, in particular above-described, circuit arrangement for an electrical machine, in particular for a starting device with a starter motor for starting an internal combustion engine, in a motor vehicle, with a current limiting device for limiting an inrush of the electric machine and a Bridging device for temporary bridging of the current limiting device.

In addition, the invention relates to a starting device for starting an internal combustion engine in a motor vehicle with, in particular described above, with a starter motor and a current limiting device for limiting an inrush current of the starter motor and with a bridging device for bypassing the current limiting device, wherein the Bridging device is switchable by means of a high potential of a voltage source. There are known starting devices which start an internal combustion engine. To start the internal combustion engine, a starter pinion is meshed with a ring gear of the internal combustion engine by means of a starter relay designed as a single-track device. At the same time, a contact bridge between two contacts is closed by the relay, which forms a circuit for the electrical

Machine to a power source closes, the circuit is designed for high currents up to 1000 or 1500 amps at about 12 to 13 volts. The starter pinion is meshed via a coarse thread so that the starter pinion meshes in the sprocket without any problems and a tooth-on-tooth position is avoided. In addition, it can be provided that the electric machine is easily turned on, wherein the circuit is guided via a series resistor. Once the engine is started, the starter pinion spurts out of the ring gear through the starter relay as an anchor, and the circuit of the electrical machine is interrupted by the contact bridge.

The high current decrease when starting an internal combustion engine causes the battery voltage from originally 12 volts to about 6 volts and possibly deeper breaks. The break-in depends on environmental parameters such as temperature and battery state of charge, the size, the resistance of the armature, the voltage drop across the carbon brushes and the supply cables. Further electrical consumers such as control units, fuel pump and headlights may possibly not be sufficiently supplied with electrical energy, so that they are affected by the start. This is at a so-called cold start d. H. at a start of an internal combustion engine before operation of the vehicle is not critical. This is more critical or unsatisfactory for the vehicle occupants, in a start-stop operation of the motor vehicle. For example, electrical consumers are affected at the restart of the internal combustion engine at a traffic light or in a traffic jam so that they do not get the necessary battery power and thus at least temporarily suspend. This is undesirable.

The applicant is aware that to limit the voltage dip, a current limiting device can be used at least briefly when starting the internal combustion engine to reduce the voltage drop by the electric machine with a reduced current over a

Pre-resistor is applied. The series resistor is in the main current path The electrical machine is switched so that even high currents of up to 600 A and more amps can flow through this. If the internal combustion engine has started, the current limiting device is bypassed via a bridging device and the starter motor is subjected to a maximum current. A large voltage dip at this time overcame. Thus, an only acceptable small voltage dip occurs. For example, the voltage dip reduces to only a range of 10 to 20 percent of an area previously 50 to 60 percent.

The Applicant is also known to provide a series resistor in the main current path of the starter motor, which is bridged over a bridging device, which is designed as a contact closer, when the starter motor is already turned on and has reached a certain speed, so that the voltage dip, as described above, at most 10 to 20 percent.

It is an object of the invention, a circuit arrangement, a method and a starting device of the type mentioned in such a way that the

Circuitry and thus the starting device over the life as stable and safe works.

Disclosure of the invention

According to the invention the object is achieved by the subject matter of claims 1, 7 and 8. The dependent claims define preferred embodiments of the invention.

It is an idea of the invention to develop a circuit arrangement known to the Applicant, so that if the bridging device malfunctions or fails and thus the series resistor would be destroyed, a failure of the starting device is avoided.

It is therefore an idea of the invention to form the lock-up device as a contact opener for this reason, wherein the contact opener in the

Current path is designed such that the contact opener is directly connected to a control switch of the electric machine switchable. Thus, the trained as a bridging contact opener is directly with no delay Voltage applied when the control switch is closed to control a starting device. The contact opener thus separates the main current path quickly, so that the electronic machine must start via a current limiting device. In the case of failure of the contact opener, however, the current limiting device is constantly bridged. So it's the conventional one

Current path with maximum current load enabled, as in a conventional cold start. The danger that the current-limiting device suffers thermal damage in the event of a functional failure of the bridging device is thus virtually automatically or automatically avoided with the directly switched contact opener.

The bridging device is released again by applying voltage to the starter motor or the electric machine and thus inducing a voltage, so that a voltage drop across the electrical machine leads to a reduction in the voltage across the bridging device, which in turn leads to the Switching contact from the contact opener in the main current path is closed again. This process preferably takes so long that a so-called short-circuit phase that is, the time duration in which a voltage dip could take place is overcome, so that, as already described above, a voltage dip is significantly reduced.

In order to set the duration to be bridged in a more defined manner depending on the type, a switching delay device is preferably arranged in a potential-mass current path direction in the current path behind the contact opener. Thus, when voltage is applied to the contact opener, it is first activated and the delay to close the open contact is previously set by the switching delay device.

According to an advantageous embodiment, the switching delay device comprises a passive component, in particular a resistor. This has the

Advantage that the passive component can be made significantly cheaper than a coil. In addition, the stored energy of the coil in the contact opener, that is, the switching relay, evenly loaded. According to a preferred or additional embodiment, to a stable

Construction, the switching delay device comprises a passive ves component, in particular a coil. With a coil which can be arranged on the core of the relay coil from the contact opener, the turn-off time can be delayed or shortened in comparison to a comparable ohmic resistance, depending on the direction of energization of the coil. The turn-off time is delayed when the energization direction and the winding direction in both coils are rectified. The turn-off time is shortened when the additional coil is energized or wound in the opposite direction of the coil from the contact opener.

Further preferably, the circuit arrangement comprises a first switching device, via which the electrical machine can be acted upon by voltage and wherein in the current path a bridging device is a safety device, in particular in the form of a diode, connected downstream. The switching device has the advantage that with the switching device high currents up to or over 1000 amperes can be switched briefly and this switching device with small

Streaming is switchable via the control switch. Thus, when switching off the e- lectric machine, the switching device is not powered by the lock-up device, which is preferably designed as a relay with a coil, this due to inductive voltage, the switching device with power, which could lead to malfunction and damage to the electrical machine, is preferably a diode to block the current in the opposite direction as a safety device downstream.

In order to form a starting device as efficiently as possible, so that a not too high thermal load occurs, the first switching device preferably comprises a pull-in winding and a holding winding, wherein the pull-in winding masseeitig on the potential side of the electric machine, in particular at a current path node with the mass of the bridging device is switched.

The holding winding, however, is connected directly to the ground side of the power source. Such a circuit has the advantage that the pull-in winding is energized for a short time, and this is low-resistance and the holding winding is high-impedance and thus requires a lower holding current.

The object is also achieved by a method in that after switching on a control switch, the bridging device is subjected to voltage and as a result, a main current path of the starter motor from the bridging is interrupted as a contact opener, wherein the main current path is closed by a first switching device and the electric machine via the current limiting device with voltage is applied, whereby due to a voltage drop across the starter motor, the voltage of the electric machine connected in series bypass device drops, so that the main current path is closed by the lock-up device and the current limiting device is bridged, wherein the main current path is interrupted by the first switching device as soon as the energized first switching device is switched off by the control switch. Thus, it is prevented by a stable structure and a stable process, that in case of malfunction or malfunction of the lock-up device the Spannungsbegrenzungsvorrich- device is unnecessarily high load, so that destruction of the high-current limiting device is avoided. The bridging device in the form of an additional relay is, as in a mono-flop module, switched off with a delay and thus forms a monostable flip-flop in the form of a contact opener.

The object is also achieved by a starting device in that the bridging device can be switched by means of a high potential at a voltage source and the bridging device is designed as a contact opener, preferably as a switching relay. Thus, the lockup device is switchable rather quickly, shift delay elements are not arranged in front of or in the lockup device. The starting device is simple and thus achieves a long life.

In order optionally to replace the lock-up device quickly and easily, or to geometrically efficiently adapt the starting device to a given installation space, the lock-up device is preferably designed as a separate component to the starter motor with a starter relay serving as a first switching device. The lockup device can thus be arranged separately on the internal combustion engine or on the body.

According to an alternative embodiment, the bridging devices are formed with the starter motor and the starter relay in a common housing or as a common assembly. In such an embodiment, zugt cables are used, which transmit under very high currents. In terms of safety, the starting device is thus simple, safe and compact.

It goes without saying that the features mentioned above and those yet to be explained below can be used not only in the respectively indicated combination but also in other combinations.

Brief description of the drawings

The invention will be explained in more detail below with reference to drawings. Show it:

1 shows a first circuit arrangement according to the invention, FIG. 2 shows a circuit arrangement according to a second embodiment, FIG. 3 shows a circuit arrangement according to a third embodiment and FIG. 4 shows a time-switching diagram.

Embodiments of the invention

Fig. 1 shows a schematic circuit diagram of an inventive

Circuit arrangement 1 for an electric machine 2. The electric machine 2 is part of a starting device 17. The starting device 17 further comprises a first switching device 5, which is designed as a relay with a pull-in winding 13 and a holding winding 14, to a first with the armature a starter pinion 25 in a ring gear 18 of an internal combustion engine 15 on and auszubpüren and on the other hand to close and open a contact bridge with a switching contact 51 of a main current path 20 of the electric machine 2 between serving as a power source battery 10 and the starter motor 2.

Furthermore, a starting resistor 3 is connected upstream of the starter motor 2 as a series resistor as a current limiting device. The switching contact 51 may be arranged in front of or behind the series resistor 3, it is preferred, as shown in FIG. 1 shown behind the switch contact 51 arranged. The starting device 17 is actuated via a control switch 8 with a switching contact 81 which switches electrical energy from the battery 10, the switching currents in a secondary current path 30 being significantly lower than the switching currents in the main current path 20. The switching currents in the main current path 20 can be in the range from to about 1000

Amperes and more. The secondary flow path 30, which primarily supplies the first switching device 5 and a bridging device 4, is designed for significantly lower currents. The starting resistor 3 is bridged by a bridging device 4 according to the invention.

The bridging device 4 further includes a second switching device 7, which is also designed as a relay, with a second switching contact 71 in order to switch very high currents from the main current path 20. The bridging device 4 is provided as a contact opener, so that in the unloaded state of the second switching device 7 of the lock-up device 4, the circuit is closed and the starting resistor 3 is bridged. The bridging device 4 is connected directly to the high potential of the battery 10 and is also controlled by the control switch 8. For this purpose, the bridging device 4 is connected at the current path node 84 of the secondary current path 30 behind the control switch 8.

Fig. 2 shows a further particular embodiment of the circuit arrangement 1 according to the invention, wherein the bridging device 4 is merely modified. To set the switching delay after opening the contact opener 7, a switching delay device 60 is provided, which in the

Fig. 2 is connected downstream as a component in the form of a resistor 61. With the ohmic resistor 61 in series, the stored energy of the coil is linearly uniformly loaded by the contact opener 7, the turn-off time (tau) = the inductance (L) / resistance (R).

In addition, a diode 9 is connected as a safety device in parallel to the switching delay device 60, so that when switching off the starter motor 2, the relay 7 is not energized vice versa and thus causes the first switching device 5 closes the switching contact 51 again, resulting in a malfunction of the starter motor 2 and thus to premature destruction or a Could cause wear. As shown in FIGS. 1 and 2, the bridging device 4 may be formed as a separate component and thus be connected or mounted separately to a conventional starting device 17 or on the body or on the internal combustion engine 15. The conventional starting device 17th is merely modified in that it comprises the starting resistor 3 and has two current path nodes 32 and 34 before and after the starting resistor 3, is connected to the lock-up device 4.

FIG. 3 again shows a circuit diagram of a circuit arrangement 1 in which only the switching delay device 60 is modified to the effect that a coil 62 is arranged instead of the resistor 61. The coil 62 is thus connected in series with the additional relay 7 and is designed for a period of time as a switching delay from the contact opener 7 is predefined desired. As a result, the so-called short-circuit point, that is to say the undesired voltage drop, is bridged in time by the use of the starting resistor 3, the switching contact 71 being open. With the coil 62, the switching delay can be extended or shortened, depending on the direction in which the coil 62 is energized. Preferably, the coil 62 is wound on the same iron core as the coil of the contact opener 7. If the coil 62 is wound in the same direction as the coil of the contact opener 7 and is also in the same

Energized, the magnetic flux is also amplified when switching off, so that a longer shutdown occurs than in a comparable ohmic resistance. Θ total = Θ7 + Θ62, where Θ total = Φ * N ² / L

If, on the other hand, the coil 62 is wound in the opposite direction to the coil of the contact opener 7 and if it is also energized in the opposite direction, a reverse effect is produced. The effective flooding of the coil of the contact opener 7 is weakened by the flooding of the second coil 62, so that the turn-off time is shortened at a comparable ohmic resistance.

Θ total = Θ7 - Θ62. Thus, the additional series-connected second coil 62 provides an effective further possibility for adapting the time behavior of the limiting module 4 to the respective application situation and type-specific. 4 shows in a time-switching diagram various switching states of a control switch 8 on the switching contact 81, the additional relay as the second switching device 7 on the switching contact 41, the current I to the second switching contact 71 and the starter motor. 2

The method for operating the circuit arrangement 1 proceeds as follows. At a time TO, the circuit is at rest. At time T1, the control switch 8 is closed and the voltage Nebenstrompfad 30 jumps to the potential voltage P at time T1. Shortly thereafter, at time T2, the voltage at the relay 7 jumps to the potential voltage P and thereby the switching contact 71 is opened, which is shown with a state change at time T2 in FIG. Just below, a time-current curve is shown in dashed line form, as can be measured on the coil of the relay 7. The current increases at time T2 until time T3. At time T3, the switching contact 51 of the first switching device 5 has been closed, so that the starter motor 2 via the main current path 20, the voltage applied.

As a result of the starter motor 2 turning on, the current I decreases, as shown in FIG. 4. The current drop follows the following formula ¹ - ¹ where tau (a time constant) = L / R, where L is equal to the inductance of the coil 7 and R is the resistance of the coil.

Until the time T4, the current has fallen so far that the switch contact 71 closes again and the starter motor M2 is applied from this time on the main current path 20 with the maximum current and the maximum voltage. The control switch 8 remains closed until the internal combustion engine 15 is started or another activation is necessary. The control switch 8 is, for example, an ignition key switch or a pulse from the ignition key switch or is controlled by the engine control, for example, for a start-stop operation. The main current path 20 is thus interrupted by the first switching device 5 only when the application of voltage from the control switch 8 is interrupted and thus switched off. Consequently is the starting resistor 3 only briefly charged in case of malfunction or non-operation of the second switching device 7, the main current path 20, as conventional, closed. Thus, a stable starting device and circuit arrangement is provided, which holds over the life and prevents a voltage dip effectively in the start-stop operation of a vehicle. All figures show only schematic not to scale representations. Incidentally, reference is made in particular to the drawings for the invention.

Claims

claims

1. Circuit arrangement (1) for an electric machine (2), in particular for a starting device with a starter motor (2) for starting an internal combustion engine (15), in a motor vehicle, with a current limiting device (3) for limiting an inrush current of the electric machine ( 2), with a bridging device (4) for bridging the current limiting device (3), wherein the bridging device (4) is directly switchable to a high potential of a voltage source (10), the bridging device (4) comprises a contact opener (7) and the contact opener (7) in a current path (83) is formed, so that the contact opener (7) directly to a control switch (8) of the electric machine (2) is switchable.

2. Circuit arrangement (1) according to claim 1, characterized in that a switching delay device (60) is arranged in a potential-ground current direction in the current path behind the contact opener (7).

3. Circuit arrangement (1) according to one of claims 1 or 2, characterized in that the switching delay device (60) comprises a passive component, in particular a coil (62).

4. Circuit arrangement (1) according to one of claims 1 to 3, characterized in that the switching delay device (60) comprises a passive component, in particular a resistor (61).

5. Circuit arrangement (1) according to one of claims 1 to 4, characterized in that the circuit arrangement (1) comprises a first switching device (5) via which the electrical machine (2) can be acted upon with voltage and wherein the current path (83) the bridging device (4) a safety device (9), in particular a diode, is connected downstream.

6. Circuit arrangement (1) according to one of claims 1 to 5, characterized in that the first switching device (5) comprises a pull-in winding (13) and a holding winding (14), wherein the pull-in winding (13) on the ground side on the potential side (21) of the electric machine (2), in particular on a current path node (24) with the ground of the bridging device (4) is connected.

Method for operating a circuit arrangement (1), in particular according to one of Claims 1 to 6, for an electric machine (2), in particular for a starting device (17) with a starter motor (2) for starting an internal combustion engine (15) in a motor vehicle with a current limiting device (3) for limiting an inrush current of the electric machine (2) and a bridging device (4) for temporary bridging of the current limiting device (3), wherein after switching on a control switch, the lockup device (4) is acted upon as a contact opener with voltage and as a result, a main current path of the starter motor (2) is interrupted by the lock-up device (4), the main current path is closed by a first switching device (5) and the electric machine (2) via the current limiting device (4) is applied with voltage as a result of a voltage drop across the starter motor (2), the S Voltage of the electrical machine connected in series bridging device (4) drops, so that the main current path (20) from the lock-up device (4) is closed again and the current limiting device (3) is bridged, wherein the main current path of the first switching device (5) interrupted becomes as soon as the supply of voltage from the control switch (8) is turned off.

Starting device (17) for starting an internal combustion engine (15) in a motor vehicle, with a circuit arrangement (1), in particular according to one of claims 1 to 8, with a starter motor (2) and with a current limiting device (3) for limiting an inrush current of the starter motor (2) and with a bridging device (4) for bridging the current limiting device (3), wherein the bridging device (4) is switchable by means of a high potential of a voltage source and the bridging device (4) as a contact opener (7), preferably as a switching relay is formed ,

9. Starting device (17) according to claim 8, wherein the bridging device (4) is designed as a separate component to the starter motor with a first switching device serving as a starter relay.

10. Starting device according to claim 8, wherein the bridging device are formed with the starter motor and the starter relay in a common housing or as a common assembly.