CH685221A5 - Automatic operating drive for fire door - Google Patents

Abstract

Automatic operating drive for fire door has eddy current brake incorporated in DC drive motor acting as damping device for door movement

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The invention relates to a drive for doors, gates or flaps, in particular for fire doors with the features in the preamble of claim 1.

In practice, such drives are known in different embodiments. They have an electric motor with which a door, a flap or a gate, in particular a sliding gate, is opened and closed by means of a traction mechanism. In the event that the power and the electric motor fail, a mechanical locking device is provided. It can also be provided for normal locking operations. The mechanical locking device consists of a pre-tensioned spring rope drum or a weight, which then mechanically close the door, gate or flap. In normal operation, at least when the motor is opened, the mechanical locking device is locked by an electrical holding magnet or the like. A separate damping device, e.g. a hydraulic radial damper is provided. The known drive is expensive to build. It also has the disadvantage that the damping can only be set to a constant value over the closing path. For this reason, an additional end position damper is usually required.

From DE-GM 9 000 881.2 a damping device in the form of an eddy current brake is known which is used instead of a hydraulic radial damper. It is also a separate component which, depending on the design of the drive, is arranged externally on the mechanical locking device or the electric motor. Since the damping should only act during the closing movement, the known damping devices require a freewheel for the opening movement of the door, gate or flap.

It is therefore an object of the present invention to show a drive for doors, gates or flaps, in particular for fire protection gates, which requires less construction effort.

The invention solves this problem with the features in claim 1.

The drive according to the invention offers a damping device integrated in the electric motor, which works as an eddy current brake via the winding short circuit which can be switched on and off as required. The short-circuited winding forms an electrical conductor which is flooded by a magnetic field in the motor, with a relative movement between the magnetic field and the winding. A permanent or externally excited DC motor, which still has a magnetic field in the event of a short circuit in the winding, meets the requirements in particular. Due to the eddy current brake integrated in the motor, additional damping devices that are expensive to construct are unnecessary. Furthermore, the winding short circuit, which can be switched on and off, means that freewheeling is no longer required.

The drive according to the invention is suitable for all types of pivoting or sliding gates,

Doors or flaps. For the sake of simplicity, only the preferred exemplary embodiment with sliding gates is referred to below. The statements apply equally to the aforementioned alternative forms of doors or flaps.

In the case of permanently excited DC motors, the drive winding, usually the armature winding, is short-circuited. With externally excited DC motors, the armature winding or the excitation winding can be short-circuited. The other winding then builds up the magnetic field. This winding can be battery-backed to maintain the magnetic field in the event of a power failure.

The winding short circuit can be switched on and off and only occurs during the closing process and under certain specified conditions. For this purpose, the electric motor has a switchable short-circuit device on the winding to be short-circuited depending on the motor design.

In the case of a drive in which the electric motor opens and closes the sliding short circuit or the eddy current brake, it only functions when the power fails in the network, but then automatically, and dampens the closing movement caused by the mechanical locking device.

Another area of application is also semi-motorized drives, in which the electric motor only takes over the opening of the sliding gate, while the mechanical movement always ensures the closing movement. In this case, the winding short circuit or the eddy current brake are in operation with every closing movement, i.e. both in normal operation and in an emergency in the event of a power failure in the network. Both drive variants are particularly suitable for fire protection devices. Fire protection sliding gates are a preferred area of application.

Any permanent or externally excited DC motor is suitable for the drive according to the invention with the integrated eddy current brake. A disc rotor motor has particularly good properties. It has no significant gearbox resistances and develops braking forces at relatively low speeds, which are in a favorable ratio to their available external driving forces.

The drive according to the invention has the particular advantage that the damping effect stabilizes itself. As soon as the effective closing force increases due to reduced friction or for other reasons, the motor speed increases with it. A higher speed also increases the braking effect. Conversely, the braking effect is reduced when the speed or closing force decreases. This automatic adaptation of the braking forces to changes in the closing force results in a very even closing movement.

The size of the braking force depends on the ohmic resistance in the short-circuited motor winding. A pure winding short circuit without additional resistance in the short circuit would have a maximum braking effect. Under certain circumstances, this can not only dampen the closing movement of the sliding gate, but even to stop5

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stand up. The latter is often not desirable. It is therefore recommended in most cases to use an additional ohmic resistor in the short-circuit, the resistance being preferably adjustable to change the damping effect. In the simplest version of a manually controlled drive, a manually adjustable potentiometer is provided for this.

In the optimal configuration of the drive according to the invention, the short-circuiting device has an electronic control which is preferably programmable and microprocessor-controlled. It controls the switch and sets the ohmic resistance in the short circuit. If the eddy current brake is to be activated in normal operation even when the power supply is intact, the control also switches the electric motor off the mains.

For the best possible damping setting, it is advisable to arrange a displacement sensor on the electric motor or at another suitable location. The position encoder is connected to the control and signals both the closing speed and the current position of the sliding gate. The closing movement can be kept constant even better by controlling and adjusting the resistance than by the aforementioned self-regulation of the eddy current effect. This applies in particular to the aforementioned alternative rotor designs. Through the path monitoring, the braking effect at the end of the closing movement can also be specifically increased via the control to achieve end position damping. A separate end position damper is therefore unnecessary.

In order to maintain the advantageous control options in the event of a power failure in the network, it is advisable to equip the electronic control system and, if necessary, the displacement sensor with a backup battery. The control of the closing speed and the end position damping can thus also be implemented in emergency operation, especially in the case of fire protection. Without a backup battery, it is advisable to arrange the manual potentiometer in the short circuit in addition to the electronic control and to integrate it into the control concept. In the event of a control failure, the braking or damping effect can still be set manually.

The invention is shown in the drawings, for example and schematically. Show in detail

Fig. 1: a perspective view of a drive with an electric motor and a short-circuit device for a sliding gate and

Fig. 2: a schematic circuit diagram for the electric motor and the short-circuit device.

In Fig. 1, the drive (1) for a sliding gate (2) is shown. The sliding gate (2) is suspended from a running rail and is opened and closed by a traction device (3), here a revolving traction rope. The pull rope is driven by an electric motor (4), which integrates an integrated damping of the closing movement

Eddy current brake (6) with a short-circuit device (7) which can be switched on and off. The drive (1) also has a mechanical locking device (5), here in the form of a spring rope drum. It can be locked in a controlled manner by an electric holding magnet (not shown) or another suitable device and is at least inoperative when the sliding gate (2) is opened.

In the exemplary embodiment shown, the sliding gate (2) has two leaves and opens centrally. Alternatively, the sliding gate (2) can also have only one wing and open to the left or right. Instead of the sliding gate (2), a rotating door or flap can also be provided, the traction means (3) being designed differently, for example as a linkage. The mechanical locking device (5) can alternatively consist of one or more additional weights, which are connected to the sliding gate (2) or a door or flap via trailing ropes. A closing movement can also take place due to the dead weight of the sliding gate (2), the door or the flap. The configurations of the drive (1) described below for a sliding gate (2) also apply accordingly to pivoting gates, doors or flaps.

The drive (1) shown can be designed in two variants with respect to the closing movement. In the first variant, the electric motor (4) ensures both the opening and the closing movement of the sliding gate (2). The mechanical locking device (5) remains locked in normal operation and out of function. It is suspended from the traction mechanism (3) via a switchable coupling. Only when there is a power failure in the network (17) (see FIG. 2) or upon a signal from a fire alarm, an external higher-level control system or the like is the mechanical locking device (5) released, coupled to the traction mechanism (3) and then closes the sliding gate (2).

In the second variant, the electric motor (4) only ever opens the sliding gate (2). The mechanical closing device (5) also ensures the closing movement in normal operation, which is released by a manual control via a corresponding signal and can be locked in any closed position of the sliding gate (2). For this purpose, it remains coupled to the traction means (3), but has a free-wheel for the motorized opening. In addition, the mechanical locking device (5) is also released in the emergency mentioned for the first variant.

The eddy current brake (6) described in more detail below in the electric motor (4) provides damping in both variants when the sliding gate (2) is closed by the mechanical locking device (5). If, however, the sliding gate (2) is opened or closed by the electric motor (4), the eddy current brake (6) is switched off and has no effect.

2 shows a preferred exemplary embodiment for the electric motor (4) of the drive (1). The electric motor (4) is permanent or

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separately excited DC motor. In the preferred and illustrated embodiment, it is a permanently excited disc rotor motor in a basic design known per se. The motor winding (11) is attached to the disc rotor (9) in the form of preferably printed or stamped lines. The disc rotor (9) rotates between circumferential permanent magnets (10).

The eddy current brake (6) integrated in the electric motor (4) is activated by a controlled short circuit in the motor winding (11). In this case, the permanent magnets (10) induce eddy currents in the rotating disc rotor (9) with its short-circuited motor winding (11). These build up an opposing magnetic field, which leads to a braking of the disc rotor (9) with the motor shaft and thus the sliding gate (2). The braking effect is greater, the lower the ohmic resistance in the motor winding (11) and in the short circuit (8).

For controlled short-circuiting of the motor winding (11), a short-circuiting device (7) which can be switched on and off is connected to the motor terminals, as is shown schematically in FIG. 2. It contains a line connected in parallel to the power lines to the network (17) with a manually or electrically controllable switch (12) and an additional ohmic resistor. This line forms the said short circuit (8) with the motor winding (11).

The switch (12) is designed as an opener, which is open for normal motor operation and switches off the short-circuiting device (7). It only closes when there is a power failure in the network (17) or when it is triggered by an external signal from a fire detector or the like. Then the short-circuit device (7) and the vortex brake (6) come into operation. In the event of a power failure, the switch (12) closes automatically. The electrical switch (12) can be of any design. In the exemplary embodiment shown, it is coupled to the network (17) via a relay. The relay keeps the switch (12) open against the force of a spring as long as the network (17) is stable.

The ohmic resistor (13) is preferably adjustable and can be designed as a potentiometer. The damping or braking force of the eddy current brake (6) is set via it. The potentiometer can be set externally by hand.

In the exemplary embodiment shown, the resistor (13) is connected to an electronic controller (14) which has a microprocessor and preferably a program memory. The controller (14) can also be connected to the electrical switch (12) and another switch (not shown) in the power lines between the network (17) and the motor winding (11). The network (17) can be suspended via the last-mentioned switch and the eddy current brake (6) can be activated despite the network (17) being intact. This is necessary if, in the aforementioned second variant, the sliding gate (2) is to be closed in normal operation with the network (17) intact via manual control by the mechanical locking device (5).

A displacement sensor (15) sits on the shaft of the electric motor (4). In the preferred embodiment, it consists of a linear or rotary potentiometer with an upstream gear. The position of the sliding gate (2) and its closing speed can be determined via the change in resistance. Alternatively, the rotary encoder (15) can be designed as an incremental encoder with a relative or absolute displacement measurement via a code disk or in any other suitable manner. The encoder signals can be evaluated in the controller (14). The controller (14) and possibly also the displacement sensor (15) are connected to a buffer battery (16) which ensures the operation of these parts even if the network (17) fails.

The controller (14) monitors the closing movement of the sliding gate (2) by means of the displacement sensor (15) and the speed evaluation and regulates it via the resistor (13). For example, it keeps the closing speed constant at 0.2 m per second. If the travel sensor (15) reports an increase in speed, the control (14) reduces the adjustable resistance (13) and thus increases the braking force of the eddy current brake (6) until the setpoint of the closing speed is reached again. Conversely, if the speed falls below the limit, the resistance (13) is increased and thus the braking force is reduced to compensate for the speed deviation.

The control (14) also monitors the path of the sliding gate (2) via the travel sensor (15). If it is at a predetermined distance before the end of the closing path, for example 1 m, the braking force of the eddy current brake (6) is increased in order to achieve end position damping. For this purpose, the control (14) reduces the resistance (13) until the closing speed is only 0.08 m per second, for example. The sliding gate (2) moves very slowly.

To increase security, a light barrier or a corresponding monitoring device for any obstacles in the closing path can be arranged. This monitoring device can be connected to the controller (14). In the event of an obstacle, the resistance (13) is reduced to the minimum value. With the appropriate motor design, this ensures maximum braking force and drive standstill (1).

Claims (9)

Claims 1. Drive for doors, gates or flaps, in particular for fire protection gates, with an electric motor, a traction device, a damping device and a mechanical locking device, characterized in that the electric motor (4) as a permanent * or externally excited DC motor and the damping device as a motor-integrated eddy current brake ( 6) is designed with switchable winding short circuit. 2. Drive according to claim 1, characterized in that the electric motor (4) has a shutdown 5 10th 15 20th 25th 30th 35 40 45 50 55 60 65 4th 7 CH 685 221 A5 Bare (12) short-circuit device (7) on the motor winding (11). 3. Drive according to claim 1 or 2, characterized in that the electric motor (4) is designed as a disc rotor motor. 4. Drive according to claim 2 or 3, characterized in that an ohmic resistor (13) is arranged in the short circuit (8). 5. Drive according to claim 4, characterized in that the resistor (13) is adjustable. 6. Drive according to one of claims 2 to 5, characterized in that an electrical switch (12) is arranged in the short circuit (8), which closes by manual control and / or in the event of a power failure in the network (17). 7. Drive according to claim 5 or 6, characterized in that the resistor (13) and / or the switch (12) are connected to an electronic control (14). 8. Drive according to claim 7, characterized in that a displacement sensor (15) is arranged on the electric motor (4), which is connected to the controller (14) by signal technology. 9. Drive according to claim 7 or 8, characterized in that the controller (14) and the displacement sensor (15) are connected to a backup battery (16). 5 10th 15 20th 25th 30th 35 40 45 50 55 60 65 5