WO2008122140A1

WO2008122140A1 - Actuator for a fire protection flap

Info

Publication number: WO2008122140A1
Application number: PCT/CH2008/000151
Authority: WO
Inventors: Werner Birchmeier
Original assignee: Newenta Ag
Priority date: 2007-04-04
Filing date: 2008-04-04
Publication date: 2008-10-16

Abstract

The invention relates to an actuator for a fire protection flap, comprising an electric motor (1). Said actuator drives a reducing gear (2) with a last, slowest output wheel (9) having an axial tubular extension (10). Said extension is rotatably arranged on a spring box (3) fixed to a mount (11). Said spring box (3) comprises a central cylindrical borehole (12) comprising the lowest windings (13) of a coil spring (4). The uppermost part (14) of the coil spring (4) is frictionally arranged on the extension (10). A sleeve is rotatably mounted on the extension (10) in such a way that it runs through same, and can receive, in the lowest part thereof, a pivoting axis (6) of the fire protection flap (7) in a form-fitting manner. The extension extends freely over the sleeve (5), between the lowest windings (13) of the coil spring (4) which is frictionally connected to the spring box (3) and the uppermost part (14) thereof, which is frictionally connected to the extension (10) of the output wheel (9). There is a small distance of between 0.05 and 0.5 mm between the sleeve (5) and the extension.

Description

Actuator for a fire damper

The present invention relates to an electric actuator for an actuator such as preferably a fire damper in ventilation ducts according to the preamble of claim 1.

Fire dampers with actuator and spring return are used as safety actuators in ventilation systems and are known per se.

The actuators are brought in the normal operation by the integrated actuator in the open position and held in this position. In the event of a fault or for the purpose of checking, the actuator should assume its safety position and be locked in this position against channel-side effects. The assumption of the safety position takes place in case of interruption of the power supply, either by a power failure or by a targeted, via control electronics and / or sensors triggered power interruption. Such a safety actuator can be used, for example, to prevent the spread of fire and smoke in ventilation systems and seal openings for ventilation ducts in fire walls in the event of fire fireproof.

Actuators with spring return for fire dampers are well known in the air conditioning, ventilation and control technology. For example, the patent EP 1 519 120 Bl (Dl) can be used. D1 discloses an actuator in which the electric motor, which opens the fire damper, simultaneously biases a spring element. The electric motor acts on the fire damper via a strongly reducing gear; The spring element has the task of closing the fire damper in case of power failure or a detected by sensors fire alarm. Its stored spring energy acts - in the reverse direction - over the same gearbox and closes the fire damper. The disadvantage of such a solution is the fact that the gearbox is used both for opening and for closing the fire damper in use, and at the conclusion of the closing process large inertial forces occur due to the large reduction of fast-running first gears. This can result in transmission failures, which are directly relevant to safety.

Further, US-PS 4,334,570 shows an arrangement in which a drive motor drives a pulley, which opens the flap against its own weight or against a biased by the opening process return spring via a wound rope. In this case, the drive motor is also after the opening process, i. as long as the flap is open (ie in normal operation), always under tension, thus keeping its torque constant and thus the flap against the pressure of the return spring open. If the power fails, a wrap spring clutch automatically relaxes due to the lost torque due to the stored spring energy and breaks the connection to the motor, with the result that the pulley can idle freely rotate so that the flap closes. The disclosed solution requires a second, with the housing firmly anchored wrap spring, which is connected via an intermediate sleeve with the first wrap spring. This arrangement has the disadvantage that the drive motor must always provide torque, ie must be under power if the flap is to remain open. In addition, it is disadvantageous that the construction of the coupling with two cooperating wrap springs is complicated.

US-PS 4,723,481 shows an arrangement in which also a drive motor opens the flap against the pressure of a return spring and, as long as the drive motor is energized, holds in the open position. If the drive current fails, a wrap spring releases due to the stored spring force and thus causes the decoupling of the drive motor, so that the flap actuated by the return spring can close. Again, the drive motor must be constantly the electricity; at the same time a cable is necessary for the reduction of the motor drive, which is connected downstream of the clutch.

EP 0 697 571 shows a further advanced arrangement in which the drive motor is designed for the high speeds of today's drive motors and connected to the damper drive via a reduction gear. The flap is held by the constantly energized motor against the force of a return spring in the open position. By the return movement high speeds are generated in the reduction gear and reduced by a centrifugal brake. In the case of spring return (closing the flap), the clutch disconnects the engine from the reduction gear. Coupling and motor form a functional unit and are realized in a single mechanical assembly. The coupling may have a wrap spring or be designed as a planetary gear; in the latter case a motorized movement of the flap in both directions is possible. Motor and flap are connected in this case, when the planet carrier (the outer gear of the planetary gear) is blocked, and released from each other when the planet carrier can rotate. A pawl blocks or releases the planetary carrier when the flap is to be closed by the return spring; in other words, the pawl controls the clutch.

This arrangement is disadvantageous that the drive motor must always be under power to keep the door open; In addition, the disclosed construction is complicated, since a centrifugal brake is provided as part of the reduction gear. Since considerable forces acting on the transmission part, which is located between the flap and the centrifugal brake, there is a risk of damage during operation, which can cause the said transmission part prevents proper closing. Accordingly, it is the object of the present invention to provide a method for operating an actuator and an actuator, which avoids disadvantages of the prior art with a simplified construction.

The solution of the problem is reflected in the characterizing part of claim 1 and of claim 2 with respect to their essential features, in the following patent claims with respect to further advantageous Ausges- configurations.

According to the invention, the following features are provided accordingly:

Firstly, a method for operating a fire damper actuator that can be returned from a closed position to an open position by a drive motor and from a return position to a closed position by a return spring element, the drive motor for starting (or due to the starting operation ) is coupled with the fire damper and this then brings in the open position, then the fire damper simultaneously or first locked in the open position by another lock and simultaneously or decoupled from the drive motor, such that the fire damper held by the lock and independent of the drive motor in the open position is and can close freely after unlocking by the return spring element.

Second, an actuator for a fire damper (7) for carrying out this method, with an electric motor (1) for opening the fire damper (7), a transmission (2) and a clutch, wherein the transmission (2) and the coupling between the electric motor (1 ) and fire damper (7) are arranged, and with a return spring element for closing the fire damper (7), which acts directly on them, wherein a lock is provided which locks the fire damper (7) after reaching the open position in this, such that the fire damper remains in the open position even when the clutch is released, until the lock is released.

Third, an actuator according to item two, wherein the latch has a pawl which operatively cooperates with an element of the fire damper (7) for locking them, and wherein the pawl by a current-carrying element, preferably an electromagnet, can be held in the locked position.

Fourth, an actuator according to point two, wherein the coupling between the transmission (2) and the fire damper (7), preferably directly on the fire damper (7) is arranged.

Fifth, an actuator for a fire damper (7) for carrying out the above method or according to one of claims two to four, with a pivot axis (6), with an electric motor (1), a transmission (2) for reducing the electric motor ( 1), a directly connected to the fire damper (7) spring element for closing the fire damper (7), wherein coupling means are provided to the fire damper (7) only during the opening process with the transmission (2) and the electric motor (1) to couple and to release this coupling immediately after completion of the opening process, and that further means are provided to keep the decoupled fire damper (7) in the open position or to trigger the closing operation of the fire damper (7) bypassing the gearbox (2) and electric motor (1) and to accomplish.

Finally, an actuator according to item 5, wherein the coupling means comprise a wrap spring.

The fact that the fire damper is held in the open position by a lock, their closing movement can be independent of the opening drive, so that the return spring must be designed only for the sufficiently fast and reliable tight closure of the fire damper. In addition, eliminating the need to keep the engine constantly powered, which saves power and allows the use of a conventional, simple and inexpensive series engine. This also applies to the transmission, which is only exposed to the stress of the inherently soft and slow movement during the opening process. It eliminates the cost of, for example, a centrifugal clutch, as provided in EP 0697 571, or for the structural reinforcement of the transmission in this case, since both the braking forces and acceleration forces must be absorbed, as they occur when the decoupling indeed through the closing process, but only after its beginning.

Last but not least, the arrangement according to the invention thus ensures that damage can not occur in the opening drive, especially as a result of a test run or else by a repeated or cyclical opening and closing of the fire damper.

In addition, according to the invention, the construction of the actuator is much easier and space-saving, it can be a standard commercial, low-cost standard gear can be used.

In a preferred embodiment, the coupling is directly on the fire damper, i. arranged according to the transmission, with the advantage that the fire damper, regardless of the condition of any element of the opening drive can close reliably.

In a particularly preferred embodiment, the slowest running wheel of the transmission, the drive wheel for the pivot axis of the actuator (ie the fire protection flap), henceforth called output gear carries a tubular axially extending extension. On this sits the uppermost part of a wrap. The lowest part of this wrap spring lies frictionally inside the barrel. Turns the output gear in the opening direction, so the wrap spring narrows in its middle part and thus puts in the KraftSchluss outside on a sleeve into which the pivot axis of the fire damper is inserted positively. As soon as this frictional connection comes to a standstill, the said sleeve rotates and thus the fire damper opens; In the same corridor, the closing spring acting directly on the fire damper is tensioned. With the achievement of the frictional connection of the wrap spring with the sleeve solves their frictional connection with the barrel. Once the fire damper is open, which requires about a 90 ° rotation of the sleeve, a stop will engage and the driving electric motor will operate against a much higher resistance. This causes a steeply rising current profile. This current profile is detected and switches off the motor at a specified value. If the fire damper has thus reached the "open" position, it is held in this position by a magnet. Simultaneously with the running of the motor, a capacitor is charged. This discharges after switching off the motor supply via the motor and lets it run backwards. As a result, the wrap is relaxed so far that it releases the sleeve. The wrap spring is thus relaxed, the motor is de-energized and the gearbox torque-free. Upon the occurrence of an alarm condition, the magnet can be released, and the fire damper closes, driven by the closing spring; The transmission is still torque-free.

Reference to the accompanying drawings, the invention is explained in detail. Show it

Fig. 1 shows a section through an assembled actuator, Fig. 2 is a plan view of a portion of the actuator.

3 shows a variant for the representation of FIG. 2.

Fig. 1 is a schematic representation of the assembled actuator. An electric motor 1 drives a reduction gear gearbox 2 with a strong reduction in the range of 500: 1 to 10 * 000: 1, as they are common and known in comparable actuators. The gears of the transmission 2 are therefore not shown. As a frame 11 for the transmission 2 is here a plate. With this frame 11 a barrel 3 is firmly connected. The barrel 3 has a central cylindrical bore 12, in which a wrap spring 4 rests with its lowermost turns 13. The terms "below" and "above" refer exclusively to the illustration of Fig. 1. Depending on the location and direction of installation of the actuator and the fire damper to be opened by them, they can of course both replaced as well as by right / left or be replaced left / right. On the fixed barrel 3, the slowest running gear of the transmission 2 is rotatably mounted and is designated by output gear 9. It has a tubular extension 10 in the axial direction. In this, the uppermost part 14 of the wrap 4 is frictionally mounted. Through the tubular extension 10 runs, rotatably mounted against it, a sleeve 5, which can receive a positive locking in its lowermost part a pivot axis 6 of a fire damper 7. Between the lowermost turns 13 of the wrap spring 4, which frictionally with the barrel 3 and its uppermost part 14 which is non-positively connected to the tubular extension 10 of the output gear 9, it runs freely over the sleeve 5. It points from the sleeve 5 a small distance in the range of 0.05 to 0.5 mm. If now the fire damper 7 are pivoted from the "closed" position to the "open" position, then the electric motor 1 drives the output gear 9 via the transmission 2. The wrap spring is so twisted that it narrows its diameter in this process, since it is frictionally connected with its lowermost turns 13 with the barrel. By this narrowing of its diameter it is now with a middle part 15 frictionally against the sleeve 5. Likewise, the frictional connection of its lowermost turns 13 with the barrel 3 now dissolves. The fire damper 7 is now pivoted into the "open" position. Essential to the invention is the conclusion of the frictional connection between the wrap spring 4 and the lowest part of the bore 12 in the relaxed state of the wrap spring 4. FIG. 2 shows a plan view of the inventive actuator from above. To relieve the figure, the remaining elements of the actuator, s. Figure 1, omitted; The person skilled in the art can readily design the elements shown in FIG. 2 in such a way that they can be operatively arranged on an actuator according to the invention. Fixedly connected to the sleeve 5 is in a first embodiment, an arm 16, which is moved in the "open" position to a holding magnet 17. The holding magnet 17 may either be an electromagnet, which holds the arm 16 in the current flowing state against the moment of a directly connected to the fire damper 7 coil spring or otherwise suitably designed spring element (not shown), or it has a permanent magnet whose magnetic flux through the current flow in the coil of the magnet can be compensated for a short time. To trigger the fire damper 7 in case of alarm, the holding magnet 17 is now briefly de-energized, or the Hai- tefluss the permanent magnet is compensated by a short surge, whereupon the fire damper 7 is driven by the moment of the coil spring in the "closed" state. In a second embodiment, Fig. 3 shows a coupled with the fire damper 7 or the sleeve 5 ratchet wheel 18 with a detent 19. In this catch 19, a pawl 20 by the spring tension of a spring arm 21 carrying them engage. The spring arm 21 is attached directly or indirectly to the frame 11. The catch 19 is arranged so that the latching of the pawl 20 can take place only when the fire damper 7 is open.

In both embodiments, the first according to Fig. 2, the second according to Fig. 3, the current in the electric motor 1 rises sharply when the "open" position is reached, the magnitude of this current being represented by an electronic circuit 22 (shown in FIG ), which then switches off the electric motor 1. While the electric motor 1 protective shutter 7 opens, the circuit 22 charges a capacitor. As soon as the pawl 20 engages in the catch 19, the drive current from electric motor 1 therefore rises and it is then switched off, the capacitor is discharged via the electric motor 1. As a result, this runs in the opposite direction to the normal direction of rotation, ie backwards. This relaxes the wrap 4, which thereby resumes its relaxed diameter in its central part 15 and in that of the lowermost turns 13 rests again on the barrel 3. On the one hand, it releases the sleeve 5, on the other hand, the force closure with the barrel 3 comes about again.

Thus, the fire damper 7 is ready to close and the actuator ready to open the closed fire damper 7 again.

The pawl 20 can be lifted either manually or by an electromagnet 23 from the catch 19, which is also directly or indirectly attached to the frame 11.

Claims

claims

1. A method for operating an actuator for a fire damper, which can be brought back by a drive motor from a closed position to an open position and by a return spring element from the open position to the closed position, characterized in that the drive motor for the start with the fire damper is coupled and then brings it into the open position, then the fire damper in the open position locked by a lock and decoupled from the drive motor, such that the fire damper is held by the lock and independent of the drive motor in the open position and can be freely released after unlocking by the return spring element ,

2. Actuator for a fire damper (7) for carrying out the method according to claim 1, comprising an electric motor (1) for opening the fire damper (7), a transmission (2) and a clutch, wherein the transmission (2) and the clutch between Electric motor (1) and fire damper (7) are arranged, and with a return spring element for closing the fire damper (7), which acts directly on this, characterized in that a lock is provided, the fire damper (7) after reaching the open position in this locked, such that the fire damper remains in the open position even when the clutch is released, until the lock is released.

3. Actuator according to claim 2, wherein the latch has a pawl which operatively cooperates with an element of the fire damper (7) for locking them, and wherein the pawl by a current-carrying element, preferably an electromagnet, in locking position can be held.

4. Actuator according to claim 1, wherein the coupling between the transmission (2) and the fire damper (7), Preferably directly on the fire damper (7) is arranged.

5. Actuator for a fire damper (7) for carrying out the method according to claim 1 or any one of claims 2 to 4, with a pivot axis (6), with an electric motor (1), a transmission (2) for reducing the electric motor (1), a directly connected to the fire damper (7) spring element for closing the fire damper (7), wherein coupling means are provided to the fire damper (7) only during the opening process with the transmission (2) and the electric motor (1) to couple and to release this coupling immediately after completion of the opening process, and that further means are provided to keep the decoupled fire damper (7) in the open position or to trigger the closing operation of the fire damper (7) bypassing the gearbox (2) and electric motor (1) and to accomplish.

6. Actuator according to claim 5, wherein the coupling means comprise a wrap spring.

7. Actuator according to claim 5 or 6, characterized in that the means consist in that - a with a frame (11) for the gearbox (2) connected barrel (3) with a central bore (12) is present,

- A sleeve (5) is provided and inserted in the bore (12) and rotatably mounted, which sleeve (5) the pivot axis (6) of the fire damper (7) receives positively, wherein between the bore (12) and the sleeve (5 ) is a sufficient distance,

the slowest running toothed wheel of the gearbox (2) has a driven wheel (9) mounted rotatably on the spring housing (3) and has an axially extending tubular extension (10), - A wrap spring (4) is present and with play in the sufficient distance between the bore (12) and sleeve (5) is inserted,

- The wrap spring (4) with its uppermost part (14) is placed on the tubular extension (10) of the output gear (9), that a frictional connection with this arises,

- The wrap spring (4) is designed so that their lowest turns (13) with the inner wall of the bore (12) have a frictional connection, wherein the normal sense of rotation of the driven wheel (9) extends so that the wrap spring (4) turned off is, whereby in its middle part (15) on the one hand a frictional connection with the sleeve

(5), on the other hand, the adhesion of the bottom Win- fertilize (13) with the inner wall is canceled, causing the sleeve (5) the fire damper (7) rotates to its open position and the spring element to close the fire damper (7) tensioned becomes.

8. An actuator according to claim 7, characterized in that an arm (16) is present and with the sleeve (5) connected so that it has in the radial direction outwards substantially, - a holding magnet (17) is provided and set up in that it can magnetically hold the arm (16) in the open position of the fire damper (7), the arm (16) abutting the holding magnet (17) when the fire damper is open.

9. Actuator according to claim 8, characterized in that the holding magnet (17) has a permanent magnet, such that the arm (16) is kept de-energized, and for the triggering of the arm (16) th the coil of the holding magnet (17) powered by a surge that compensates for the magnetic flux of the permanent magnet.

10. An actuator according to claim 8, characterized in that the holding magnet (17) is an electromagnet which is flowed through to hold the arm (16) by a Dauerström, and that the currentlessness of the holding magnet (17) triggers the arm (16).

11. Actuator according to claim 7, characterized in that

- The fire damper (7) or the sleeve (5) with a ratchet wheel (18) is directly connected, which has a catch (19), a spring arm (21) with a pawl (20) and the frame (11) so fixed is that the pawl (21) engages in the open position of the fire damper (7) in the catch (19) and the electric motor (1) via the transmission (2) prevents further rotation.

12. An actuator according to claim 6 or 7, characterized in that the electric motor (1) has an electronic circuit (22).

13. Actuator according to claim 11 and 12, characterized in that

- The electronic circuit (22) has a detector which monitors the current of the electric motor (1) and by the engagement of the pawl (20) in a catch (19) or the abutment of the arm (16) on the holding magnet (17 ) ascending increase of the electric motor (1) supplying current, - the electronic circuit (22) further includes a capacitor which is charged during operation of the electric motor (1),

- The electronic circuit, the electric motor (1) turns off upon detection of said current increase and then discharges the capacitor via the electric motor (1), whereby this runs backward in accordance with the stored charge, relieving the wrap spring (4) and thereby the force closure with the sleeve (5) is released, and early the adhesion of the lowermost turns (13) with the wall of the bore (12) is restored.

14. Actuator according to claim 11, characterized in that the pawl (20) can be extended manually for testing purposes.

15. Actuator according to claim 11, characterized in that an electromagnet (23) is present, with whose operation the pawl (20) can be extended.