DE19514229A1 - Electric drive load disconnector e.g. for tilting or hinged window casement - Google Patents

Abstract

There is an electric drive motor with a work shaft and a microswitch (S1) forcibly actuated, or released, at an overload. The motor and microswitch are relatively movable such that an overload, e.g. mechanical blocking of the shaft, the relative motion takes place with automatic microswitch engagement for the motor switch-off. The microswitch is of mechanical or electric type and is coupled to a Triac (T1, 2) and/or a thyristor and/or a transistor, but pref. several thyristors or transistors, or to combinations of thyristors and transistor for the motor (M) load disconnection.

Description

The invention relates to a load cut-off device with the features of Preamble of claim 1.

Such a load cut-off device is e.g. B. from DE-GM 92 18 638 known. It is used there for an electric push rod drive. The boost rod drive has an electromechanical motor, the motorab drive shaft drives a spindle. The push rod is with one on the spindle guided spindle nut connected and serves to actuate a window sash gels or an accessory to such a wing, e.g. B. roller shutters, blinds or similar.

The electromechanical motor is in a stationary drive unit housed via a slip clutch in such a way that when an ab occurs drive side overload triggers the slip clutch and the motor in the housing thereby forcibly moves with the actuation or release of a microphone switch, which is part of the load cut-off device.  

In conventional known designs, the Motors via the microswitch using a relay circuit. The disadvantage is here that the relay is susceptible to wear when larger span occurs voltage can burn the relay and the relay if the voltage is too low does not switch.

The invention has for its object a load cut-off device to create the type mentioned above, the less prone to wear, especially is reliable and switchable without delay.

This object is achieved by the invention with the subject matter of claim 1.

The load cut-off device is preferably used with electric push rods drives with spindle motor used. It can be constructed as in DE-GM 92 18 638. Such drives are preferably used as Ausstellvor directions of window sashes or flaps. The drive comes with one end its housing hinged on the frame or on the wing and in ent speaking, the output end of the push rod on the wing or supported on the frame. The drive housing can also be rigid Frame or attached to the wing and the output-side thrust rod can be coupled with an actuating linkage, which one on the wing orderly operating scissors, e.g. B. fanlight opener drives. Fanlight opener with control rods are z. B. from DE-OS 36 27 741 or DE-OS 31 40 855 be knows.

Further features and advantages result from the following description Exercise, in which an embodiment explained in connection with the figures becomes.

Show:

Fig. 1 is a Lastabschaltvorrichtung with micro switch to an electromechanical motor;

Fig. 2 is a block diagram of the load cut with micro switch and triac of Fig. 1,

Fig. 3 is a circuit diagram of the load shutdown with microswitch and triac of Fig. 1, in an embodiment that is also suitable for a pulse width controlled input signal with line monitoring.

In the exemplary embodiment shown, the load switch-off device is used in a drive which has an electromechanical motor 1 which is supported in a housing 2 via a spring (not shown) acting as a slip clutch. The motor 1 interacts with a microswitch S1 fixedly arranged in the housing 2 . The microswitch S1 is part of the load cut-off device, the circuit of which is shown in FIGS . 2 and 3 in detail.

The storage of the engine 1 via a slip clutch in the housing 2 is, for. B. from DE-GM 92 18 638 known. During normal operation of the motor, ie when there is no overload, ie no blocking, on the output shaft of the motor, the motor 1 is mounted in a rotationally fixed manner via the slip clutch in the housing 2 , ie the spring holds the motor 1 in a certain rotational position in the housing 2 . The microswitch S1 is permanently actuated via a confirmation stop fixed on the motor 1 . If there is now an overload on the motor output shaft, the motor 1 tries to rotate against the action of the spring of the slip clutch in the housing 2 . When a torque is exceeded, the slip clutch is triggered, ie the motor 1 rotates in the housing 2 . The motor-operated actuation stop 1 a releases the microswitch S1.

Reference is made to FIG. 2.

If microswitch S1 is released, motor 1 switches off. When the motor is switched off, the holding current of the triac is undershot and the motor is switched off. The motor now turns back to its normal operating position due to the spring force and actuates the microswitch S1 again and switches back, so that the motor is again connected to the supply voltage. Since the capacitor C is still charged, the triac cannot re-ignite since the capacitor C is charged and an ignition current cannot therefore flow, although the motor is connected to the terminal X1 again via S1. The engine remains switched off.

The motor 1 can only be switched on again by reversing the polarity or by briefly (a few microseconds) interrupting the supply voltage, since the capacitor is recharged when the polarity is reversed and a current can flow as a result. The supply voltage can be reversed as quickly as desired.

The resistor R ensures that the capacitor is discharged in the event of an supply.

Further functions result from the circuit diagram in FIG. 3.

If microswitch S1 is released, motor 1 switches off and ignites triac T1. When the motor is switched off, the holding current of the Triac T2 is not reached. The motor now turns back to its normal operating position due to the spring force and actuates the microswitch S1 again. Since T1 is now conductive, T2 cannot ignite again, although the motor is connected to terminal X1 again via S1. The engine remains switched off.

The motor 1 can only be switched on again by reversing the polarity or by briefly (a few µs) interrupting the supply voltage. The supply voltage can be reversed as quickly as desired.

Through the additional circuit D3, D4, C1, C2, R1 and R2 one is possibly pulsating supply voltage (e.g. pulse width modulated signal with 25 kHz) depending on the direction (D3, R1 and C1 or D4, R2 and C2) in the same direction tet. As a result, the Triac T1 remains the supplier even during the pulse pauses supply voltage for the memory function of the load cut-off conductive.

The motor is switched on again when the load cut-off is activated by reversing the polarity as quickly as possible or short (depending on the dimensioning, e.g. 100 µs) supply voltage can be interrupted.

The varistor protects the circuit from excessive self-induction voltages when the engine is switched off and before faults caused by the supply voltage nung. The additional circuit R5, D1 and D2 is used for line monitoring Cable break through the control center.

Special features and function of this load cut-off:
The motor runs forwards or backwards depending on the polarity of the supply voltage applied. The speed (and force) of the motor can be adjusted by the level of the DC voltage or by a pulse width modulated voltage.

If the motor is overloaded or runs against an end stop (e.g. one Spindle), then the load cut-off switches off. The engine can by short Interrupting the supply voltage can be started again or by Reverse polarity of the applied supply voltage at X1 and X2 to the other Start again in the direction.

The circuit can be used for a very wide voltage range (only be limits by the dielectric strength of the components used). The Versor voltage can be reversed very quickly with this circuit.  

The microswitch S1 is arranged on a circuit board 3 , which is fixed in an end cap 4 of the housing 2 . On the board 3 , the circuit shown in Fig. 2 Darge is realized. To power the motor 1 and the Lastab switching device with microswitch S1, a connecting cable 5 is provided, which is inserted into the housing 2 in the area of the end cap 4 .

Claims (7)

1. Load cut-off device for an electric drive for a wing, in particular tilting or folding wing, z. B. for a window, a ventilation system, smoke and heat exhaust system or the like, or for an accessory to such a wing, for. B. shutters, blinds or the like Chen,
with an electric motor with output shaft and in the event of overload, forcibly actuatable or releasable switch, in particular micro switch, by the electric motor and the switch being mounted so as to be movable relative to one another and when an overload occurs, for. B. mechanical Blockie ren of the output shaft, the relative movement occurs and the microswitch is actuated or released automatically and thereby the engine is switched off, characterized in that
that the switch (S1) as a mechanical or electronic switch, for. B. microswitch or opto coupler, is formed and for the purpose of load shutdown of the motor (M) with a triac (T, T2) and / or a thyristor and / or a transistor, preferably a plurality of thyristors or transistors or combinations of thyristor and transistor, is connected . 2. Load cut-off device according to claim 1, characterized records that a memory (T1; C) for the overload condition until Reverse polarity or brief interruption of the supply voltage ver is applied. 3. Load cut-off device according to one of the preceding claims, there characterized in that the triac (T1) with a second triac (T2) or a capacitor (C) is connected.   4. Load cut-off device according to one of the preceding claims, there characterized in that a line monitoring with two diodes (D1, D2) and a resistor (R5) is provided. 5. Switch-off device according to one of the preceding claims, there characterized in that a device (D3, D4, C1, C2, R1, R2) is provided for rectification, preferably directionally pending rectification, a pulsating supply voltage for the Memory (T1). 6. Load cut-off device according to one of the preceding claims, there characterized in that a varistor is provided to protect the circuit from excessive self-induction voltages when switching off the engine or previous malfunctions caused by the supply tension. 7. Load cut-off device according to one of the preceding claims, there characterized in that a triac (T, T2) or thyristor or transistor is used to switch the motor on and off.