DE2655585B1

DE2655585B1 - Arrangement for controlling an electric motor

Info

Publication number: DE2655585B1
Application number: DE19762655585
Authority: DE
Inventors: Rolf Anschuetz; Eckhardt Schmid
Original assignee: SWF Spezialfabrik fuer Autozubehoer Gustav Rau GmbH
Current assignee: SWF Auto Electric GmbH
Priority date: 1976-12-08
Filing date: 1976-12-08
Publication date: 1978-06-08
Also published as: GB1592286A; IT1088315B; FR2373912A1; DE2655585C2; FR2373912B3

Description

zum Elektromagneten umzuschalten, dann aber keine Verriegelung vorzusehen, so daß bei völliger Auffüllung des Speichers auch während der Betriebszeit des Hilfsaggregates der Elektromotor wieder abgeschaltet wird.to switch to the electromagnet, but then no locking to be provided, so that when completely filled of the memory, the electric motor is also switched off again during the operating time of the auxiliary unit will.

Die Erfindung wird nachstehend anhand der in der Zeichnung dargestellten Ausführungsbeispiele näher erläutert. Es zeigtThe invention is explained in more detail below with reference to the exemplary embodiments shown in the drawing explained. It shows

F i g. 1 ein erstes Ausführungsbeispiel einer Steuerschaltung, F i g. 1 shows a first embodiment of a control circuit,

F i g. 2 ein zweites Ausführungsbeispiel mit Umsteuerung des Hysteresisschalters undF i g. 2 a second embodiment with reversal of the hysteresis switch and

F i g. 3 einen Längsschnitt durch einen Vakuumschalter. F i g. 3 shows a longitudinal section through a vacuum switch.

In F i g. 1 ist mit 10 ein Elektromotor bezeichnet, der zum Antrieb einer nur schematisch dargestellten Vakuumpumpe 11 dient Der durch die Pumpe 11 erzeugte Unterdruck wird von einem Vakuumschalter 12 gemessen, dessen bewegliches Kontaktstück 13 zur Schließung des Motorstromkreises dient Der Vakuumschalter 12 hat eine Hysteresis derart, daß beispielsweise bei einem Unterdruck von 0,5 Bar der Elektromotor 10 eingeschaltet und bei einem Unterdruck von 0,7 Bar wieder ausgeschaltet wird. Der Unterdruck in dem nicht dargestellten Energiespeicher pendelt also zwischen diesen beiden Werten.In Fig. 1 is denoted by 10 an electric motor, which is only shown schematically for driving a Vacuum pump 11 is used The negative pressure generated by the pump 11 is controlled by a vacuum switch 12 measured, whose movable contact piece 13 is used to close the motor circuit. The vacuum switch 12 has a hysteresis such that, for example, at a negative pressure of 0.5 bar, the electric motor 10 is switched on and switched off again at a vacuum of 0.7 bar. The negative pressure in that is not The energy store shown oscillates between these two values.

In der Praxis wird also beim Einschalten eines Hilfsaggregates nicht der maxmale Unterdruck zur Verfügung stehen und die Betriebssicherheit ist gefährdet, wenn die gespeicherte Energie zu stark verbraucht wird. Zusätzlich zu der selbsttätigen Ansteuerung über den Vakuumschalter 12 ist deshalb der Elektromotor direkt über den Schalter 14 ansteuerbar, der bei Inbetriebnahme des Hilfsaggregates betätigt wird. Bei Servobremsanlagen wird man vorzugsweise den Bremslichtschalter verwenden, der parallel zum Hysteresisschalter geschaltet wird und während der Betriebszeit der Bremse geschlossen ist, so daß in dieser Zeit die Pumpe arbeitet. Ein zu starker Energieverlust wird auf diese Weise unverzögert ausgeglichen.In practice, when an auxiliary unit is switched on, the maximum negative pressure is not used Are available and operational safety is endangered if the stored energy is too strong is consumed. In addition to the automatic control via the vacuum switch 12 is therefore the electric motor can be controlled directly via the switch 14, which is activated when the auxiliary unit is started up is operated. In the case of servo braking systems, the brake light switch will preferably be used, the is switched in parallel to the hysteresis switch and the brake is closed during the operating time, so that the pump is working during this time. In this way, an excessive loss of energy is instantaneous balanced.

Bei dem Ausführungsbeispiel gemäß F i g. 2 greift an dem beweglichen Kontaktstück 13 des Vakuumschalters 12 der Anker 15 eines Elektromagneten 16 an, der seinerseits über den Schalter 14, beispielsweise den Bremslichtschalter, angesteuert wird. Mit der Inbetriebnahme des Hilfsaggregates wird daher das Kontaktstück 13 in die stabile Schaltstellung umgeschaltet, in der der Motorstromkreis geschlossen ist Es wird in dieser Schaltstellung durch den Elektromagneten festgehalten, auch wenn der Unterdruck über den einen Grenzwert von beispielsweise 0,7 Bar hinausgeht Andererseits bedeutet dies, daß diese Schaltstellung auch beibehalten wird, wenn der Unterdruck diesen Grenzwert beim Abschalten des Hilfsaggregates nicht erreicht hat In diesem Fall läuft der Elektromotor und damit die Pumpe auch nach dem Abschalten des Hilfsaggregates weiter und es ist sichergestellt, daß bei jeder Betätigung des Hilfsaggregates der Energiespeicher voll aufgefüllt wird. Auf diese Weise wird eine hohe Betriebssicherheit bei einer gegenüber dem bekannten System wesentlich reduzierten Pumpenlaufzeit erreicht.In the embodiment according to FIG. 2 engages the movable contact piece 13 of the vacuum switch 12 of the armature 15 of an electromagnet 16, which in turn via the switch 14, for example the Brake light switch, is controlled. With the start-up of the auxiliary unit, the contact piece is therefore 13 switched to the stable switching position in which the motor circuit is closed. In this Switching position held by the electromagnet, even if the negative pressure is above one limit value of 0.7 bar, for example, on the other hand, this means that this switch position is also maintained If the negative pressure has not reached this limit when the auxiliary unit is switched off, In In this case, the electric motor and thus the pump continue to run even after the auxiliary unit has been switched off and it is ensured that the energy store is fully filled each time the auxiliary unit is actuated will. In this way, a high level of operational reliability is essential in comparison with the known system reduced pump runtime achieved.

In Fig.2 ist schematisch dargestellt, daß der Elektromagnet 16 und der Vakuumschalter 12 zu einer Baueinheit zusammengefaßt sind. Diese Baueinheit hat Anschlußkontakte 20 und 21 zum Anschluß an den positiven und negativen Pol einer Spannungsquelle und eingangsseitig weiterhin einen Kontakt 22 zumIn Figure 2 it is shown schematically that the electromagnet 16 and the vacuum switch 12 to one Structural unit are summarized. This unit has connection contacts 20 and 21 for connection to the positive and negative pole of a voltage source and on the input side also a contact 22 for

ίο Anschluß an den Schalter 14. Ausgangsseitig sind Kontakte 24 und 25 zum Anschluß des Elektromotors 10 vorgesehen. Innerhalb der Baueinheit ist die Wicklung des Elektromagneten an den negativen Pol angeschlossen. Diese Art der Verdrahtung hat sich bewährt, weil dann der Elektromotor direkt an diese Baueinheit anschließbar ist und eine separate Masseleitung von der Spannungsquelle zum Elektromotor 10 entfällt.ίο Connection to switch 14 on the output side Contacts 24 and 25 are provided for connecting the electric motor 10. The winding is inside the unit of the electromagnet connected to the negative pole. This type of wiring has been proven because then the electric motor can be connected directly to this unit and a separate ground line from the There is no voltage source for the electric motor 10.

In F i g. 3 ist ein Längsschnitt durch diese Baueinheit gezeigt. In einem metallischen Gehäuse 30 ist eine bewegliche Membran 31 festgelegt. An dieser Membran stützt sich ein Schaltstück 32 ab, an dem in bekannter Weise eine Schnappfeder 33 aufgehängt ist, die als bewegliches Kontaktstück 13 dient. Das Gehäuse ist abgeschlossen durch eine Bodenplatte 34, die zugleich als Wickelkörper für die Wicklung 35 des Elektromagneten 16 dient. Mit dem Schaltstück 32 ist der Anker 36 des Elektromagneten fest verbunden, der sich auf der anderen Seite an einer einstellbaren Druckfeder 37 abstützt. Diese Druckfeder 37 drückt den Anker 36 und damit das Schaltstück 32 gegen die Membran 31, so daß im Normalfall die Umschaltung des beweglichen Kontaktstückes 13 durch die Bewegung der Membran bewirkt wird.In Fig. 3 shows a longitudinal section through this structural unit. In a metallic housing 30 is a movable membrane 31 set. A contact piece 32 is supported on this membrane, on which in known Manner, a snap spring 33 is suspended, which serves as a movable contact piece 13. The case is completed by a base plate 34, which also acts as a winding body for the winding 35 of the electromagnet 16 serves. With the switching piece 32 of the armature 36 of the electromagnet is firmly connected, which is on the the other side is supported on an adjustable compression spring 37. This compression spring 37 presses the armature 36 and so that the switching piece 32 against the membrane 31, so that in the normal case, the switching of the movable Contact piece 13 is effected by the movement of the membrane.

In F i g. 3 ist die Schaltstellung des Vakuumschalters gezeigt, in der der Motorstromkreis geschlossen ist. Das Kontaktstück an der Schnappfeder 33 liegt auf zwei Festkontakten auf, von denen einer dargestellt und mit 38 bezeichnet ist. Dieser Festkontakt ist mit dem Anschlußkontakt 20 in Fig.2 elektrisch leitend verbunden. Sobald die Pumpe läuft, wird die Membran 31 in Richtung des Pfeiles A ausgelenkt, bis bei Erreichen des Grenzwertes die Schnappfeder 33 umspringt und den Elektromotor abschaltet.In Fig. 3 shows the switching position of the vacuum switch in which the motor circuit is closed. The contact piece on the snap spring 33 rests on two fixed contacts, one of which is shown and denoted by 38. This fixed contact is connected in an electrically conductive manner to the connection contact 20 in FIG. As soon as the pump is running, the membrane 31 is deflected in the direction of arrow A until, when the limit value is reached, the snap spring 33 jumps over and switches off the electric motor.

Wird nun die Wicklung 35 des Elektromagneten erregt, verschiebt sich der Anker 36 entgegen der Kraft der Druckfeder 37 in Richtung des Pfeiles B, so daß die Schnappfeder 33 wieder in ihre andere stabile Lage umspringt. Dabei hebt das Schaltstück 32 von der Membran ab und die Größe der gespeicherten Energie hat auf das Schaltverhalten keinen Einfluß, bis nach Ablauf der Betriebszeit der Anker 36 wieder freigegeben wird. Der Vakuumschalter 12 ist also während der Betriebszeit im leitenden Schaltzustand verriegelt.
Der Grundgedanke der Erfindung ist auch bei Systemen mit einem hydraulischen Druckspeicher anwendbar. Der Vakuumschalter muß dann durch einen entsprechenden Druckschalter mit Hysteresisverhalten ersetzt werden.If the coil 35 of the electromagnet is now excited, the armature 36 moves against the force of the compression spring 37 in the direction of arrow B, so that the snap spring 33 jumps back into its other stable position. The contact piece 32 lifts off the membrane and the size of the stored energy has no influence on the switching behavior until the armature 36 is released again after the operating time has elapsed. The vacuum switch 12 is therefore locked in the conductive switching state during the operating time.
The basic concept of the invention can also be used in systems with a hydraulic pressure accumulator. The vacuum switch must then be replaced by a corresponding pressure switch with hysteresis behavior.

Hierzu 2 Blatt ZeichnungenFor this purpose 2 sheets of drawings

Claims

Patent claims:

1. Arrangement for controlling an electric motor, which has a pump for filling an energy store for the operation of auxiliary units in motor vehicles, in particular for a servo brake drives, in which the electric motor can be controlled via a hysteresis switch that switches to different Responds to limit values of the stored energy, characterized in that the electric motor (10) is also independent of the The value of the stored energy is switched on with the commissioning of the auxiliary unit.

2. Arrangement according to claim 1, characterized in that the electric motor (10) during the Operating time of the auxiliary unit remains switched on

3. Arrangement according to claim 1, characterized in that the electric motor (10) on the Operating time of the auxiliary unit remains switched on until the hysteresis switch (12,13) on the upper limit of the stored energy responds.

4. Arrangement according to claim 2, characterized in that the electric motor (10) has a Switch (14) which is closed during the operating time of the auxiliary unit, for example the Brake light switch, can be controlled parallel to the hysteresis switch (12,13)

5. Arrangement according to claim 1 or 3, characterized in that with the commissioning of the Auxiliary unit of the hysteresis switch is switched to the conductive switching state.

6. Arrangement according to claim 5, characterized in that the hysteresis switch (12, 13) is locked in the conductive switching state during the operating time of the auxiliary unit.

7. Arrangement according to claim 5 or 6, characterized in that the hysteresis switch (12, 13) is switched by an electromagnet (15, 16).

8. Arrangement according to claim 7, characterized in that the electromagnet (15,16) has a during the operating time of the auxiliary unit closed switch (14), for example the Brake light switch, is controlled.

9. Arrangement according to claim 7 or 8, characterized in that the hysteresis switch (12,13) and the electromagnet (15, 16) are combined to form a structural unit that this structural unit on the one hand Connection contacts (20,21,22) for connection to a voltage source and for connecting the switch (14) and on the other hand two connection contacts (24,25) for connecting the motor (10).

10. Arrangement according to one of claims 7 to 9, characterized in that the hysteresis switch (12) has a membrane (31) on which a movable contact piece (22) with a snap spring is located (33) supports that this contact piece with a centrally arranged, movable in the axial direction The armature (36) of the electromagnet (16) is connected, which acts against the force of a compression spring (37) the contact piece (32) lifts off in front of the membrane and the snap spring serving as a contact piece (13) (33) switches to its stable switching position in which the motor circuit is closed

The invention relates to an arrangement for controlling an electric motor according to the preamble of claim 1.

In modern motor vehicles, auxiliary units such as power brakes, power steering, Servo coupling or door and window locking devices with support from a hydraulic or pneumatic energy storage. The one to generate the necessary negative or positive pressure Serving pump is driven in new developments by an electric motor, which has a The hysteresis switch is controlled in such a way that, for example, the negative pressure is between two limit values between 0.5 and 0.7 bar. In contrast to the known systems with one from the drive motor of the motor vehicle continuously driven pump are therefore only the electric motor and thus the pump switched on when the amount of stored energy drops to the lower limit value. Man this achieves a longer service life for the system. On the other hand, that's the disadvantage connected that when starting up the auxiliary unit usually not the maximum negative pressure for Is available and a certain period of time elapses before the electric motor of the pump is switched on.

The invention is based on the object of eliminating the inertia of the arrangement and thus a to achieve greater operational safety of the motor vehicle.

This object is achieved according to the invention with an arrangement of the type mentioned in the preamble of claim 1 solved in that the electric motor is also independent of the value of the stored energy the start-up of the auxiliary unit is switched on.

When the auxiliary unit is put into operation, the energy store is therefore filled up without delay. Included remains in a first embodiment of the invention, the electric motor during the operating time of the Auxiliary unit switched on by having a switch that is very simple in terms of circuit technology is closed during the operating time of the auxiliary unit, such as the brake light switch, parallel to Hystersis switch is activated. A complete filling of the energy storage is, however, with this Execution not guaranteed, on the other hand this solution has the advantage of a short runtime of the Electric motor and the pump.

According to an advantageous embodiment of the invention, it is provided in an improved embodiment, that the electric motor remains switched on beyond the operating time of the auxiliary unit until the Hysteresis switch responds to the upper limit of the stored energy. That’s after everyone Commissioning of the auxiliary unit of the energy storage fully filled.

This can be implemented very easily in that when the auxiliary unit is started up, the The hysteresis switch is switched to the conductive switching state and during the operating time of the Auxiliary unit is locked in this switching state. In a preferred embodiment, it is used for switching an electromagnet that is controlled by the brake light switch, but it is also a purely mechanical one Execution controlled by the brake pedal is conceivable.

Finally, however, a third alternative is conceivable, namely the hysteresis switch with commissioning of the auxiliary unit by a short control pulse