Fire damper electric actuator

Abstract

This patent provides a fire damper electric actuator with strong reliability, fast action, automatic closing, local and remote manual or electric opening and closing, easy operation, and adjustable torque. It includes a base plate assembly, a main shaft assembly, a locking assembly, a driving assembly, an electromagnet, and a manual cable; the base plate is used to connect the actuator with the valve body and install other components; the locking assembly includes a lock tongue and a hook, which is used to open and position the actuator; the main shaft assembly is used to store energy and provide power, including a locking disk, a main shaft, a spring box, a spiral spring, a ratchet, and a pawl; the driving assembly is used to open the fire damper; the electromagnet and the manual cable are used to unlock the actuator and close the fire damper. The manual cable is connected to one end of the hook; when the manual cable is pulled, the hook is driven to swing, the free end of the lock tongue is separated from the hook, the locking wheel pushes the lock tongue to swing under the action of the locking disk, and the main shaft rotates rapidly under the action of the spiral spring, and reaches the closed state instantly.

Description

Technical Field

[0001] This patent relates to an electric actuator installed on fire dampers in ventilation systems of ships and high-rise buildings, which is used to manually or electrically open the fire dampers, and automatically close the fire dampers in case of temperature control, automatic power failure, remote manual or remote electric rapid closing. Background Art

[0002] Chinese patents ZL200620106001.5 and ZL201020105713.1 disclose "remote smoke exhaust valve actuators", which also provide a remotely operated actuator, but cannot meet the requirements of fire dampers in ship ventilation systems;

[0003] At present, most of the products on the market are from the Swiss company BELIMO, but this product has a long closing time (~16-20s). When manually operated, one needs to use a ladder to reach the air valve to insert the manual operating handle into the lever hole to open it. This makes the operation difficult, slow, and inconvenient. Summary of the invention

[0004] The purpose of this patent is to provide an electric fire damper actuator with high reliability, fast action, automatic closing, local and remote manual or electric opening and closing, easy operation and adjustable torque.

[0005] The fire damper electric actuator described in this patent includes a base plate assembly, a main shaft assembly, a locking assembly, a drive assembly, an electromagnet, and a manual cable;

[0006] The bottom plate assembly includes a bottom plate, a bearing, a bearing seat fixed on the bottom plate, a first pin shaft, a second pin shaft, and a third pin shaft; the bearing is installed in the bearing seat;

[0007] The spindle assembly includes a locking plate, a spindle, a spring box, a volute spring, a ratchet, and a pawl; the spindle with the locking plate fixed thereon is installed on the bearing, and a groove is provided on the periphery of the locking plate; the outer ring of the volute spring located in the spring box is fixed on the spring box, the inner ring of the volute spring is fixed on the spindle, the ratchet is fixed on the spring box, and the spindle passes through the spring box and the ratchet; the pawl cooperating with the ratchet is swingably arranged on the first pin shaft; a first spring is arranged between the pawl and the first pin shaft, and the first spring keeps the pawl in contact with the ratchet teeth on the ratchet; when the ratchet is rotated, the spring box rotates accordingly, and the preload force of the volute spring can be adjusted, and the output torque also changes accordingly;

[0008] The locking assembly includes a lock tongue and a hook; the lock tongue is swingably arranged on the second pin shaft, the locking wheel is installed on the lock tongue, and a second spring is arranged between the lock tongue and the second pin shaft, the second spring makes the lock tongue swing around the second pin shaft, and the locking wheel keeps in contact with the periphery of the locking disk; when the elastic force of the spiral spring is overcome and the main shaft is rotated, the fire damper electric actuator is in an open state, and the locking wheel falls into the groove on the locking disk; the hook is swingably arranged on the third pin shaft, and a third spring is arranged between the hook and the third pin shaft, and the third spring is in a normal state so that one end of the hook hooks the free end of the lock tongue when the locking wheel falls into the groove, thereby preventing the locking disk and the main shaft from rotating under the action of the spiral spring;

[0009] The driving assembly is used to overcome the elastic force of the volute spring to drive the main shaft to rotate, so that the electric actuator of the fire damper is in an open state;

[0010] The armature in the electromagnet arranged on the bottom plate is connected to one end of the hook through a pull rod; the electromagnet is connected to the control circuit; when the electromagnet is energized through the control circuit, the armature moves, and the hook is driven by the pull rod to swing to overcome the elastic force of the third spring, and the free end of the lock tongue is separated from the hook. The locking wheel pushes the lock tongue to swing to overcome the elastic force of the second spring under the action of the locking disk, and the locking wheel leaves the groove. The main shaft rotates rapidly under the action of the spiral spring and reaches the closed state instantly.

[0011] The manual cable is connected to one end of the hook; when the manual cable is pulled, the hook is driven to swing to overcome the elastic force of the third spring, the free end of the lock tongue is separated from the hook, and the locking wheel pushes the lock tongue under the action of the locking disk to overcome the elastic force of the second spring and swing, the locking wheel leaves the groove, and the main shaft rotates rapidly under the action of the spiral spring, and reaches the closed state instantly.

[0012] The above-mentioned fire damper electric actuator also includes a charging and discharging capacitor connected in the control circuit; when the control circuit is powered off, the capacitor discharges to the electromagnet so that the electromagnet is energized and the armature moves.

[0013] The above-mentioned fire damper electric actuator also includes a brake lever and a temperature-sensitive fuse arranged on the bottom plate; the temperature-sensitive fuse includes a slide bar passing through the bottom plate and being able to slide downward relative to the bottom plate, and a fifth spring that makes the slide bar have a downward sliding tendency; the brake lever is swingably arranged on the fourth pin shaft, and a fourth spring is arranged between the brake lever and the fourth pin shaft, the fourth spring makes one side of the brake lever contact with the slide bar extending from the upper part of the bottom plate, the slide bar on the upper part of the bottom plate blocks the swing of the brake lever, prevents the brake lever from contacting with the hook, and prevents the hook from rotating under the action of the brake lever to overcome the elastic force of the third spring; when a fire occurs, the air temperature in the air duct rises, when the air temperature in the air duct exceeds 67°C, the fusible piece on the temperature-sensitive fuse melts, the slide bar slides downward under the action of the fifth spring, the brake lever pushes the hook under the action of the fourth spring, so that the hook swings to overcome the elastic force of the third spring, the free end of the lock tongue detaches from the hook, the locking wheel pushes the lock tongue to swing to overcome the elastic force of the second spring under the action of the locking disk, the locking wheel leaves the groove, the main shaft rotates under the action of the spiral spring, and reaches the closed state instantly.

[0014] The above-mentioned fire damper electric actuator also includes a reset handle. By rotating the reset handle, the main shaft overcomes the elastic force of the spiral spring and rotates, so that the fire damper electric actuator is in an open state.

[0015] The above-mentioned fire damper electric actuator also includes a cover shell fixed on the upper part of the base plate, and the locking plate, spring box, spiral spring, ratchet, pawl, lock tongue and hook are located in the cover shell. A guide hole is opened on the cover shell, through which a manual cable can pass and guide the manual cable.

[0016] The above-mentioned fire damper electric actuator, the driving assembly includes a micro reduction motor with a reduction box, a gear reduction mechanism, and a crank connecting rod mechanism; the micro reduction motor with a reduction box is installed above the base plate, the gear reduction mechanism is installed below the base plate, the input end gear is connected to the output shaft of the micro reduction motor, the output end gear is hinged on the first pull block, one end of the connecting rod is fixedly connected to the first pull block, the connecting rod passes through the second pull block hinged on the cam, the end is screwed with an adjusting nut, and the cam is fixed to the lower end of the main shaft.

[0017] When in use, the main shaft of the fire damper penetrates into the main shaft of the electric actuator and is fixed to the main shaft of the electric actuator with a set screw, and the valve plate of the fire damper opens and closes with the electric actuator.

[0018] Compared with the existing technology, the advantages of this fire damper electric actuator are: simple operation, the fire damper can be opened or closed by pressing the control button or pulling the manual rope; fast action, the closing time of this fire damper electric actuator is instantaneous; strong reliability, this fire damper electric actuator has four closing modes: temperature-controlled automatic closing, power-off automatic closing, manual or electric closing; adjustable torque, the volute spring preload force can be adjusted through the ratchet pawl mechanism to meet the torque required to close fire dampers of different sizes. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Front view of the fire damper electric actuator in the open state;

[0020] Figure 2 yes Figure 1 A top view of

[0021] Figure 3 yes Figure 1 Side view of

[0022] Figure 4 yes Figure 1 Bottom view of

[0023] Figure 5 yes Figure 2 AA section view in;

[0024] Figure 6 Front view of the fire damper electric actuator in the open state;

[0025] Figure 7 yes Figure 6 A top view of

[0026] Figure 8 yes Figure 6 Side view of

[0027] Fig. 9 yes Figure 6 Bottom view of

[0028] Fig.10 yes Figure 7 BB section view in.

[0029] In the figure, the bottom plate assembly 1, the first pin 11, the second pin 12, the third pin 13, the fourth pin 14, the bearing seat 15, the bearing 16, the bottom plate 17, the cover 18, and the guide hole 181;

[0030] Spindle assembly 2, spindle 21, locking plate 22, groove 221, flat spiral spring 23, spring box 24, ratchet 25, pawl 26, first spiral spring 27;

[0031] Driving assembly 3, secondary reduction cylindrical gear 31, micro reduction motor 32, first pull block 33, connecting rod 34, cam 35, second pull block 36, adjusting nut 37;

[0032] Locking assembly 4, locking tongue 41, locking wheel 42, hook 43, second coil spring 44, third coil spring 45;

[0033] Temperature sensing component 5, temperature sensing fuse 50, sliding rod 51, fifth coil spring 52, fixing rod 53, fusible piece 54, brake lever 55, fourth coil spring 56;

[0034] Reset handle 6, manual pull rope 7, electromagnet 8. DETAILED DESCRIPTION

[0035] The entire fire damper electric actuator is composed of a base plate assembly 1, a main shaft assembly 2, a drive assembly 3, a locking assembly 4, a temperature sensing assembly 5, a reset handle 6, a manual pull cable 7, an electromagnet 8, a capacitor, a micro switch assembly 9, etc.

[0036] Bottom plate assembly 1: The bearing seat 15 is welded to the bottom plate 17, four pins, namely the first pin 11, the second pin 12, the third pin 13, and the fourth pin 14 are riveted to the bottom plate, the bearing 16 is installed in the bearing seat 15, and the bottom of the cover 18 is fixed to the periphery of the bottom plate with screws.

[0037] Spindle assembly 2: The spindle 21 with a locking plate 22 is mounted on the bearing 16, and a groove 221 is formed on the periphery of the locking plate. The inner ring of the plane spiral spring 23 is fixed on the spindle 21, and the outer ring is fixed on the spring box 24. The ratchet 25 is fixed on the spring box, and the spindle passes through the spring box and the ratchet. The pawl 26 is swingably mounted on the first pin 11. The first coil spring 27 is sleeved on the first pin, one end of which is fixed on the pawl and the other end is fixed on the bottom plate, so that the pawl has a counterclockwise rotation torque, so that the pawl keeps in contact with the ratchet teeth of the ratchet.

[0038] Driving component 3: A micro reduction motor 32 with a reduction box is installed above the base plate 17, and a secondary cylindrical reduction gear 31 is installed below the base plate 17. The input end gear is connected to the output shaft of the micro reduction motor. The output end gear is hinged on the first pull block 33, and one end of the connecting rod 34 is fixed to the first pull block 33. The connecting rod 34 passes through the second pull block 36 hinged on the cam 35, and the end is screwed with an adjusting nut 37. The cam 35 is fixed to the lower end of the main shaft 21.

[0039] Locking assembly 4: The lock tongue 41 is swingably set on the second pin shaft 12, and the locking wheel 42 is installed in the middle position of the lock tongue; the second coil spring 44 is sleeved on the second pin shaft 12, one end of which is fixed on the lock tongue 41 and the other end is fixed on the bottom plate 17, so that the lock tongue 41 has a clockwise rotation torque, so that the locking wheel 42 has a tendency to maintain contact with the periphery or groove 221 of the locking plate 22. The middle part of the hook 43 is rotatably set on the third pin shaft 13, and the third coil spring 45 is sleeved on the pin shaft 13, one end of which is fixed on the hook 43 and the other end is fixed on the bottom plate 17, so that the hook 43 has a counterclockwise rotation torque. When the fire damper electric actuator is opened, the left end side of the hook 43 will hook the free end of the lock tongue 41, so that the locking wheel 42 is in the groove 221, so that the main shaft will not rotate counterclockwise due to the action of the spiral spring.

[0040] The reset handle 6 is detachably connected to the upper end of the main shaft 21 passing through the housing.

[0041] When the fire damper electric actuator is in the closed state, when the reset handle is connected to the main shaft, turn the reset handle clockwise (from the upper end to the lower end of the main shaft), the reset handle drives the main shaft to overcome the elastic force of the spiral spring and rotate 90° clockwise, the locking plate rotates clockwise with the main shaft, and the locking wheel on the lock tongue falls into the groove, and the fire damper electric actuator recovers from the closed state to the open state, achieving reset.

[0042] The process of driving the electric actuator of the fire damper to reset by the drive assembly 3 including the micro motor 32 is similar to the process of operating the electric actuator of the fire damper to reset by the reset handle. When the electric actuator of the fire damper is in the closed state, the micro motor 32 is actuated, and the output end gear of the secondary reduction cylindrical gear 31 is rotated, and the first pull block 33 and the connecting rod 34 hinged on the output end gear are actuated, and the adjusting nut 37 at the end of the connecting rod 34 contacts the second pull block 36 hinged on the cam 35, driving the cam 35 installed at the lower end of the main shaft to rotate, and the main shaft 21 rotates clockwise (from the upper end of the main shaft to the lower end), and the locking disk 22 rotates clockwise with the main shaft; when the main shaft and the locking disk 22 rotate 90°, the locking wheel on the lock tongue falls into the groove, and the electric actuator of the fire damper is restored from the closed state to the open state, and the reset is achieved. When the locking wheel on the lock tongue falls into the groove, the main shaft and the locking disk no longer rotate, but the micro motor 32 still moves. At this time, the connecting rod 34 moves relative to the second pull block 36 until the adjusting nut 37 at the end of the connecting rod 34 leaves the second pull block 36 on the cam 35 by a certain distance without contact (the state of the fire damper electric actuator in the open state). In other words, every time the micro motor 32 moves, it drives the output end gear of the secondary reduction cylindrical gear 31 to rotate one circle. Regardless of whether the fire damper electric actuator is in the closed state or in the open state, the positions of the output end gear of the secondary reduction cylindrical gear 31 and the connecting rod 34 are the same. When the fire damper electric actuator is in the open state, the adjusting nut 37 leaves the second pull block 36 by a certain distance without contact, which is to prepare for the subsequent closing of the fire damper electric actuator. When the fire damper electric actuator is closed, the main shaft, locking plate and cam 35 rotate counterclockwise (viewed from the upper end of the main shaft to the lower end) a certain angle under the action of the spiral spring, while the connecting rod 34 does not move at this time. In order to prevent the adjusting nut 37 from hindering the counterclockwise rotation of the cam 35, before closing the fire damper electric actuator, the adjusting nut 37 must be away from the second pull block 36 by a certain distance without contacting it.

[0043] The brake lever 55 is swingably set on the fourth pin shaft 14, and the fourth coil spring 56 is sleeved on the fourth pin shaft, one end of which is fixed on the brake lever and the other end is fixed on the bottom plate, so that the brake lever has a torque for clockwise rotation. The temperature-sensitive fuse 50 belongs to the prior art. The temperature-sensitive fuse is fixed on the fuse seat of the bottom plate 17. In normal state, the slide bar 51 of the temperature-sensitive fuse blocks the swing of the brake lever 55. When the air temperature in the air duct reaches 70±3℃, the fusible piece 54 on the temperature-sensitive fuse melts, and the slide bar 51 slides downward under the action of the fifth spring 52. The brake lever 55 pushes the hook 43 under the action of the fourth spring 56, so that the hook 43 swings against the elastic force of the third spring 45, and the free end of the lock tongue 41 is separated from the hook 43. The locking wheel 42 pushes the lock tongue 41 under the action of the locking disk 22 to overcome the elastic force of the second spring and swing, and the locking wheel leaves the groove. The main shaft rotates rapidly under the action of the spiral spring and reaches the closed state instantly. The electromagnet 8 is mounted on the bottom plate, and the armature in the electromagnet is connected to one end of the hook 43 through a pull rod; the electromagnet and the charging and discharging capacitor are connected to the control circuit.

[0044] The control circuit has a closing button. When the closing button is pressed and the electromagnet is energized through the control circuit, the armature moves, and the hook is driven by the pull rod to swing clockwise to overcome the elastic force of the third spring, and the free end of the lock tongue is separated from the hook. The locking wheel pushes the lock tongue to swing under the action of the locking disk to overcome the elastic force of the second spring, and the locking wheel leaves the groove. The locking disk and the main shaft rotate counterclockwise under the action of the spiral spring, and the electric actuator of the fire damper is closed. When the control circuit loses power, the capacitor discharges to the electromagnet, and the electromagnet is energized and also performs similar actions, so that the electric actuator of the fire damper is closed. Because the installation position of the fire damper is generally high, a manual cable 7 is set for easy operation. The manual cable 7 is connected to the left end of the hook and extends downward through the guide hole 181 located on the cover 18 to a position that is easy to operate. People can directly pull the manual cable without climbing. Pull the manual cable to drive the hook to swing clockwise to overcome the elastic force of the third spring, the free end of the lock tongue detaches from the hook, and the locking wheel pushes the lock tongue under the action of the locking disk to overcome the elastic force of the second spring and swing, the locking wheel leaves the groove, and the locking disk and the main shaft rotate counterclockwise under the action of the spiral spring, and the fire damper electric actuator is closed.

[0045] When the fire damper electric actuator is closed, the operation process of opening the fire damper electric actuator is as follows:

[0046] Manual: Turn the reset handle 6 clockwise by hand. The reset handle 6 drives the main shaft 21 to rotate clockwise to overcome the elastic force of the spiral spring 23. The locking plate 22 rotates clockwise with the main shaft. When the rotation angle of the main shaft reaches 90°, the locking wheel 42 on the lock tongue 41 falls into the groove 221, and the left end side of the hook 43 hooks the free end of the lock tongue 41. The fire damper electric actuator remains in the open state to achieve reset.

[0047] Electric: Press the opening button on the control box, the micro-reduction motor 32 will start, the first pull block 33 will be driven to rotate through the secondary reduction cylindrical gear 31, and the second pull block 36 on the cam 35 will be pulled through the connecting rod 34, the main shaft will rotate clockwise (from the upper end of the main shaft to the lower end), the locking plate 22 will rotate clockwise with the main shaft, when the main shaft rotates at an angle of 90°, the locking wheel 42 on the lock tongue 41 will fall into the groove 221, the left end side of the hook 43 will hook the free end of the lock tongue 41, the fire damper electric actuator will remain in the open state, and reset will be achieved. When the main shaft rotates at an angle of 90°, the main shaft stops rotating, and the micro-reduction motor continues to rotate until the output end gear of the secondary reduction cylindrical gear rotates 360 degrees.

[0048] The action process of closing the fire damper electric actuator:

[0049] Automatic closing: The temperature sensing component is activated, the brake lever rotates clockwise to push the hook, the hook rotates clockwise and disengages from the lock tongue, the locking wheel disengages from the groove on the locking disk, the main shaft rotates counterclockwise rapidly under the action of the plane volute spring, and the air valve is closed;

[0050] Power failure and closing: disconnect the power supply, the built-in capacitor discharges to the electromagnet, the electromagnet is energized and moves, driving the hook connected to the electromagnet to move, the hook rotates clockwise, disengages from the lock tongue, the locking wheel disengages from the groove on the locking disk, the main shaft rotates counterclockwise rapidly under the action of the plane volute spring, and the air valve is closed;

[0051] Electric closing: Press the closing button on the control box (i.e. the closing button in the control circuit that controls the action of the electromagnet), the electromagnet is energized and actuated, driving the hook connected to the electromagnet to actuate, the hook rotates clockwise, disengages from the lock tongue, the locking wheel disengages from the groove on the locking disk, the main shaft rotates rapidly counterclockwise under the action of the plane volute spring, and the air valve is closed;

[0052] Manual closing: Pull the manual cable by hand, the hook rotates clockwise and disengages from the lock tongue, the locking wheel disengages from the groove on the locking disk, the main shaft rotates counterclockwise rapidly under the action of the flat volute spring, and the air valve is closed.

[0053] In this patent, the base plate is used to connect the actuator to the valve body and install other components; the locking assembly is used to open and position the actuator; the spindle assembly is used to store energy and provide power; the drive assembly and reset handle are used to electrically or manually open the fire damper; the temperature sensing assembly is used to sense the heat in the air duct and automatically close the fire damper after a fire occurs; the electromagnet, capacitor, and manual pull cable are used to unlock the actuator and close the fire damper; the cover serves as a protection and identification.

Claims

1. Fire damper electric actuator, its characteristics are: It includes a base plate assembly, a spindle assembly, a locking assembly, a driving assembly, an electromagnet, and a manual cable; The bottom plate assembly includes a bottom plate, a bearing, a bearing seat fixed on the bottom plate, a first pin shaft, a second pin shaft, and a third pin shaft; the bearing is installed in the bearing seat; The spindle assembly includes a locking plate, a spindle, a spring box, a spiral spring, a ratchet, and a pawl; the spindle with the locking plate fixed thereon is installed on a bearing, and a groove is formed on the periphery of the locking plate; the outer ring of the spiral spring located in the spring box is fixed on the spring box, the inner ring of the spiral spring is fixed on the spindle, the ratchet is fixed on the spring box, and the spindle passes through the spring box and the ratchet; the ratchet pawl cooperating with the ratchet is swingably arranged on a first pin shaft; a first spring is arranged between the ratchet pawl and the first pin shaft, and the first spring enables the ratchet pawl to keep in contact with the ratchet teeth on the ratchet; Turn the ratchet wheel and the spring box will rotate accordingly, which can adjust the preload force of the volute spring and the output torque will also change accordingly; The locking assembly includes a lock tongue and a hook; the lock tongue is swingably arranged on the second pin shaft, the locking wheel is installed on the lock tongue, and a second spring is arranged between the lock tongue and the second pin shaft, the second spring makes the lock tongue swing around the second pin shaft, and the locking wheel keeps in contact with the periphery of the locking disk; when the elastic force of the spiral spring is overcome and the main shaft is rotated, the fire damper electric actuator is in an open state, and the locking wheel falls into the groove on the locking disk; the hook is swingably arranged on the third pin shaft, and a third spring is arranged between the hook and the third pin shaft, and the third spring is in a normal state so that one end of the hook hooks the free end of the lock tongue when the locking wheel falls into the groove, thereby preventing the locking disk and the main shaft from rotating under the action of the spiral spring; The driving assembly is used to overcome the elastic force of the volute spring to drive the main shaft to rotate, so that the electric actuator of the fire damper is in an open state; The armature in the electromagnet arranged on the bottom plate is connected to one end of the hook through a pull rod; the electromagnet is connected to the control circuit; when the electromagnet is energized through the control circuit, the armature moves, and the hook is driven by the pull rod to swing against the elastic force of the third spring, and the free end of the lock tongue is separated from the hook, and the locking wheel pushes the lock tongue to swing against the elastic force of the second spring under the action of the locking disk, and the locking wheel leaves the groove, and the main shaft rotates rapidly under the action of the spiral spring to reach a closed state; The manual cable is connected to one end of the hook; when the manual cable is pulled, the hook is driven to swing against the elastic force of the third spring, the free end of the lock tongue is separated from the hook, and the locking wheel pushes the lock tongue to swing against the elastic force of the second spring under the action of the locking disk, the locking wheel leaves the groove, and the main shaft rotates rapidly under the action of the spiral spring to reach the closed state; It also includes a brake lever and a temperature-sensitive fuse arranged on the bottom plate; the temperature-sensitive fuse includes a slide rod passing through the bottom plate and being able to slide downward relative to the bottom plate, and a fifth spring that makes the slide rod have a downward sliding tendency; the brake lever is swingably arranged on a fourth pin shaft, and a fourth spring is arranged between the brake lever and the fourth pin shaft, and the fourth spring makes one side of the brake lever contact with the slide rod extending out of the upper part of the bottom plate, and the slide rod on the upper part of the bottom plate blocks the swing of the brake lever, preventing the brake lever from contacting the hook, and preventing the hook from rotating under the action of the brake lever to overcome the elastic force of the third spring; when a fire occurs, the air temperature in the air duct rises, and when the air temperature in the air duct exceeds 67°C, the fusible link on the temperature-sensitive fuse melts, the slide rod slides downward under the action of the fifth spring, and the brake lever pushes the hook under the action of the fourth spring, so that the hook swings to overcome the elastic force of the third spring, and the free end of the lock tongue is separated from the hook, and the locking wheel pushes the lock tongue to swing to overcome the elastic force of the second spring under the action of the locking disk, and the locking wheel leaves the groove, and the main shaft rotates under the action of the spiral spring to reach a closed state; The utility model also comprises a reset handle. By rotating the reset handle, the main shaft overcomes the elastic force of the spiral spring and rotates, so that the electric actuator of the fire damper is in an open state.

2. The fire damper electric actuator according to claim 1, characterized in that: It also includes a charging and discharging capacitor connected in the control circuit; when the control circuit is powered off, the capacitor discharges to the electromagnet so that the electromagnet is energized and the armature moves.

3. The fire damper electric actuator according to claim 1, characterized in that: It also includes a cover shell fixed on the upper part of the bottom plate. The locking plate, spring box, spiral spring, ratchet, pawl, lock tongue and hook are located in the cover shell. A guide hole is opened on the cover shell, through which a manual cable can pass and guide the manual cable.

4. The fire damper electric actuator according to claim 1, characterized in that: The driving assembly includes a micro reduction motor with a reduction box, a gear reduction mechanism, and a crank-connecting rod mechanism; the micro reduction motor with a reduction box is installed above the base plate, the gear reduction mechanism is installed below the base plate, the input end gear is connected to the output shaft of the micro reduction motor, the output end gear is hinged on the first pull block, one end of the connecting rod is fixedly connected to the first pull block, the connecting rod passes through the second pull block hinged on the cam, the end is screwed with an adjusting nut, and the cam is fixed to the lower end of the main shaft.

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