Smoke exhaust fire damper secondary actuator

Abstract

This invention discloses a secondary actuator for a smoke exhaust fire damper, comprising a base plate, a cam fixed to the upper shaft section of the valve body main shaft, a rotating wheel fitted onto the upper shaft section, and a linkage pin of the rotating wheel inserted into the first arc-shaped limiting hole of the cam; the base plate is equipped with a rocker arm, a rocker frame, and an electromagnet, with the electromagnet core shaft connected to the first end of the rocker arm; when the valve body is closed, the electromagnet is de-energized, the rocker arm latch engages with the first end of the rocker frame, and the protrusion of the rocker frame engages with the cam notch; a primary torsion spring for a forward rotating cam is fitted onto the upper shaft section, with both ends of the primary torsion spring fixed to the upper shaft section and the rotating wheel respectively; the base plate is also equipped with a temperature sensor, with the upper part of the rotating wheel abutting against the contact point of the temperature sensor; a secondary torsion spring for a reverse rotating wheel is fitted onto the main shaft; the base plate is equipped with a second arc-shaped limiting hole and a downwardly protruding mounting plate, the main body of the secondary torsion spring is fitted onto the lower shaft section, and the upper vertical section of the secondary torsion spring passes through the second arc-shaped limiting hole and is fixed to the rotating wheel, with the lower end of the secondary torsion spring hooked to the mounting plate. This mechanism can prevent the upper part from impacting the tail end of the rocker frame when the rotating wheel resets and the chain is engaged.

Description

Technical Field

[0001] This invention relates to the field of safety engineering, specifically to a secondary actuator for a smoke exhaust fire damper. Background Technology

[0002] The actuator is an important component of the smoke exhaust fire damper. Its main function is to drive the valve plate to rotate 90 degrees forward or backward via the main shaft to open or close the valve body.

[0003] The most basic valve body actuator is a single-action mechanism. It includes a base plate, with the valve body's main shaft passing through the base plate and fixed to a cam. The cam has a notch. The base plate is rotatably mounted with a rocker arm via a rocker arm shaft and a rocker frame via a rocker frame shaft. An electromagnet is also mounted on the base plate. The electromagnet's spindle is connected to the head end of the rocker arm. In the initial state, the electromagnet is de-energized, the spindle extends, and the latch at the tail end of the rocker arm engages with the head end of the rocker frame. The protrusion in the middle section of the rocker frame engages with the notch in the cam. A reset torsion spring is fitted on the rocker frame shaft to bring the rocker frame closer to the cam, and a primary torsion spring is fitted on the main shaft to rotate the cam in the forward direction. The valve body is in the closed state.

[0004] In the event of a fire, energizing the electromagnet causes the spindle to retract, thereby pulling the first end of the swing arm. Alternatively, the first end of the swing arm can be pulled manually, causing the tail end of the swing arm to rise and detach from the swing frame. Since the force of the primary torsion spring is much greater than that of the reset torsion spring, the swing frame, now free from the constraint of the swing arm, cannot prevent the cam from rotating in the forward direction. That is, the protrusion of the swing frame is pushed out of the notch by the cam, and the cam rotates in the forward direction, driving the main shaft and valve plate to rotate 90 degrees in the forward direction, opening the valve to exhaust smoke.

[0005] However, as the fire develops, flames spread outwards along the opened valve; the basic primary actuator cannot effectively intervene in this situation. Therefore, the industry has developed an upgraded secondary actuator, such as... Figure 1 , Figure 2 As shown, a temperature sensor 102 is added to the base plate 101, and the upper shaft section 103 protruding from the base plate of the main shaft is lengthened and heightened. A movable rotating wheel 104 and a secondary torsion spring 105 are added to this upper shaft section. The rotating wheel is located below the cam 106 and is concentric with the cam. The rotating wheel is fixed with an upwardly protruding linkage pin 107. The cam has an arc-shaped limiting hole 108, and the linkage pin is inserted into the arc-shaped limiting hole. The torque of the secondary torsion spring is greater than that of the primary torsion spring 109 and is located below the primary torsion spring. The upper end of the secondary torsion spring is fixed to the rotating wheel and the lower end is fixed to the base plate. The upper end of the primary torsion spring is still fixed to the main shaft, but the lower end is no longer fixed to the base plate but is hooked to the upper part of the rotating wheel. The secondary torsion spring causes the rotating wheel to have a tendency to rotate in the opposite direction, but because the upper part of the rotating wheel abuts against the contact point of the temperature sensor, the tendency of the rotating wheel to rotate in the opposite direction is counteracted and it remains stationary.

[0006] The aforementioned secondary actuator operates on the same principle as the primary actuator in the basic model during the initial stage of a fire. An electromagnet or manual pull triggers a chain reaction between the swing arm and the swing frame, releasing the cam. Under the action of a primary torsion spring, the cam pushes open the convex post of the swing frame, rotating clockwise until the end of the cam's arc-shaped limiting hole abuts against the linkage pin of the rotating wheel. At this point, the cam has rotated exactly 90 degrees clockwise, opening the valve to vent smoke. As the fire spreads further, it melts the temperature sensor, triggering a secondary action of the mechanism. This causes the temperature sensor contacts to retract and no longer abut against the upper part of the rotating wheel. In this way, the second torsion spring drives the rotating wheel to rotate counterclockwise. Furthermore, because the base has a control mechanism... The stop column of the wheel's reverse rotation amplitude will abut against the stop column after the wheel reverses 90 degrees. In this way, the wheel linkage pin will also drive the cam and main shaft to rotate 90 degrees in the opposite direction, closing the valve again to prevent the flames from spreading. After the fire is extinguished, replace the new temperature sensor, and then use a wrench to rotate the main shaft 90 degrees in the forward direction. The cam and linkage pin will drive the wheel to rotate in the forward direction, so that the upper part of the wheel will re-hook the contact of the temperature sensor. Then use a wrench to rotate the main shaft 90 degrees in the reverse direction, so that the cam reverses and the notch is aligned with the swing frame protrusion again. In this way, the protrusion will re-engage with the cam notch and the first end of the swing frame will be re-engaged by the tail end of the swing rod, thus completing the reset and winding process.

[0007] The aforementioned secondary actuator has the following drawbacks. First, regarding the rotating wheel, a stop post is only provided on the reverse side, but there is no effective limit in the forward rotation direction. Therefore, when a worker uses a wrench to rotate the wheel forward to reset it, it is difficult to control the force, and excessive force can easily be applied, causing the upper part of the wheel to roll past the temperature sensor contact and continue rotating forward, eventually impacting the tail end of the swing frame. This causes vibration damage to the swing frame, swing frame shaft, and the reset torsion spring on the swing frame shaft, leading to loosening and increasing the failure rate. Furthermore, due to the limited size of the actuator itself, and the densely packed components near the tail end of the swing frame, there is no space to install a second stop post to protect the swing frame. Moreover, since the secondary actuator is modified from the primary actuator, due to inertia, technicians, in order to meet the requirements of the second torsion spring… Assembly inevitably involves raising the upper shaft section of the main shaft above the base plate, and fitting the second and first torsion springs together onto the raised shaft section. This means the torque generated by both torsion springs acts on the same side of the base plate, specifically the shaft section above it, causing an imbalance in force. Furthermore, the increased height of this shaft section amplifies the impact of the torque imbalance, increasing the failure rate. Moreover, the presence of the secondary torsion spring and the rotating wheel raises the cam, consequently raising the positions of the swing arm and swing frame. This significantly increases the amplitude of the swing deformation at the swing frame shaft and its cantilevered end when under stress, further increasing the failure rate at that location. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to provide a secondary actuator for a smoke exhaust fire damper that can prevent the upper part from hitting the tail end of the swing frame when the wheel is reset and the chain is engaged, make the main shaft located on both sides of the base plate bear equal force, and prevent the swing rod shaft and the swing frame shaft from swinging and shaking significantly when they are under force.

[0009] The technical solution of the present invention is to provide a secondary actuator for a smoke exhaust fire damper, which includes a base plate, a main shaft of the valve body passing through the base plate, a cam fixed on the upper shaft section of the main shaft above the base plate, a notch on the cam, and a rotating wheel concentric with the cam rotatably fitted on the upper shaft section, with a protruding linkage pin fixed on the rotating wheel, and a first arc-shaped limiting hole hollowed out on the cam, with the linkage pin inserted into the first arc-shaped limiting hole.

[0010] The base plate is rotatably mounted with a swing rod via a swing rod shaft and a swing frame via a swing frame shaft. An electromagnet is also provided on the base plate, and the core shaft of the electromagnet is connected to the head end of the swing rod.

[0011] In the initial state, when the valve body is closed, the electromagnet is de-energized and the spindle extends. The latch at the end of the swing arm engages with the head of the swing frame. The protrusion in the middle section of the swing frame engages with the notch in the cam. A return spring is provided between the swing frame and the base plate to bring the swing frame closer to the cam. A primary torsion spring for rotating the cam in the forward direction is also fitted on the upper shaft section. The upper end of the primary torsion spring is fixed to the upper shaft section, and the lower end is fixed to the upper protrusion of the rotating wheel. A temperature sensor is also provided on the base plate. A secondary torsion spring for rotating the wheel in the reverse direction is fitted on the main shaft. The upper end of the secondary torsion spring is fixed to the rotating wheel. The upper part of the rotating wheel abuts against the contact of the temperature sensor.

[0012] The base plate also has a second arc-shaped limiting hole, and the base plate has a downward protruding mounting plate. The main body of the secondary torsion spring is fitted onto the lower shaft section of the main shaft which is lower than the base plate, while the upper vertical section of the secondary torsion spring passes through the second arc-shaped limiting hole and is fixed to the rotating wheel. The lower end of the secondary torsion spring is hooked to the mounting plate.

[0013] When the upper vertical section of the secondary torsion spring abuts against the first end of the second arc-shaped limiting hole, the upward-turning part of the rotating wheel passes over and hooks the temperature sensor contact, but there is a gap between it and the tail end of the swing frame.

[0014] This secondary actuator possesses all the functions of existing secondary actuators. When a fire occurs, an electromagnet or manual pulling triggers the interlocking action of the swing arm, swing frame, and cam, causing the cam to rotate 90 degrees clockwise. The tail end of the first arc-shaped limiting hole abuts against the linkage pin of the rotating wheel, opening the valve to vent smoke. If the fire is extinguished, a wrench is used to reverse the main shaft and cam by 90 degrees, causing the swing frame protrusion to re-engage with the cam notch, triggering the linkage between the swing frame and the swing arm, resetting the cam and winding the chain. However, if the fire spreads, the temperature sensor melts, the contact retracts, the rotating wheel is released, and the linkage pin drives the cam and main shaft to rotate 90 degrees counterclockwise, closing the valve again to isolate the flames. After the fire is extinguished, a new temperature sensor is replaced, and the main shaft is rotated 90 degrees clockwise again to reset the rotating wheel and winding the chain. The main shaft is then rotated 90 degrees counterclockwise again to reset the cam and winding the chain.

[0015] Compared with existing technologies, the secondary actuator with the above structure has the following advantages and technical effects.

[0016] The design of this structure breaks through the traditional approach of lengthening the upper shaft section of the main shaft and adding a secondary torsion spring to the extended section of the main shaft. It creatively drills through the base plate to form a second arc-shaped limiting hole, and instead assembles the main body of the secondary torsion spring on the lower shaft section below the base plate. An installation plate is added under the base plate to fix the lower end of the secondary torsion spring. This solves the following three problems in one fell swoop. Firstly, by using the two ends of the second arc-shaped limiting hole to limit the front and rear extreme positions of the vertical section of the secondary torsion spring, the maximum amplitude of the circumferential rotation of the wheel is limited. This not only eliminates the need for the stop on the reverse side in existing technologies, but more importantly, it precisely locks the extreme position of the wheel in the forward rotation direction. Therefore, when the worker resets the wheel in the forward direction, they only need to push the upward flipping part of the wheel past the temperature sensor contact point without worrying about the upward flipping part continuing to hit the swing frame due to excessive force. This eliminates the drawback of the upward flipping part hitting the oscillating swing frame and swing frame shaft due to excessive force during reset, preventing them from loosening and being damaged, reducing the failure rate, and solving the problem that existing technologies cannot limit the forward extreme position of the upward flipping part of the wheel; Secondly, by placing the second torsion spring and the first torsion spring on opposite sides of the base plate, the two... The torque generated by the two torsion springs acts symmetrically on the shaft sections on both sides of the base plate, making the main shaft more balanced. Moreover, with the two torsion springs positioned on both sides of the base plate, the height of the upper shaft section is significantly reduced, and its cantilever height is also reduced accordingly, further reducing the swaying caused by the two torsion springs under stress, and further reducing the failure rate. Similarly, since the secondary torsion spring is moved to the lower shaft section, the installation height of the rotating wheel cam above the secondary torsion spring is also reduced, and the position of the swing arm and swing frame that are linked with the cam is also lowered. This makes the rotating wheel, cam, swing arm, and swing frame all close to the base plate, with the distance between each of the above components and the base plate not exceeding 10mm. In this way, when the swing arm and swing frame are under stress, the amplitude of the swing deformation of the swing frame shaft and the cantilever end of the swing frame shaft is significantly reduced, further reducing the failure rate at this position.

[0017] The preferred return spring is a return tension spring, with one end fixed to the head of the swing frame and the other end fixed to the electromagnet mounting base on the base plate. This provides continuous and stable traction to the swing frame, ensuring that the swing frame tends to move closer to the cam. Unlike the return torsion spring in the prior art, it does not need to be fitted onto the swing frame shaft, thus shortening the length and height of the swing frame shaft. This ensures that the swing frame is close to the base plate, reduces the sway amplitude of the cantilevered end of the swing frame shaft when the swing frame is under force, improves stability, and reduces the failure rate. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the secondary actuator of a smoke exhaust fire damper in the existing technology.

[0019] Figure 2 yes Figure 1 A schematic diagram of the structure after being deflected at a certain angle.

[0020] Figure 3 This is a schematic diagram of the secondary actuator of the smoke exhaust fire damper of the present invention.

[0021] Figure 4 , Figure 5 , Figure 6 yes Figure 3 Schematic diagrams of the structure from different angles.

[0022] Figure 7 This is a schematic diagram of the structure of the secondary actuator of the smoke exhaust fire damper of the present invention after removing the obstructing parts, leaving the cam, the wheel and the base plate.

[0023] Figure 8 , Figure 9 , Figure 10 yes Figure 7 Schematic diagrams of the structure from different angles.

[0024] Figure 11 yes Figure 7 A schematic diagram of the structure after removing the base plate.

[0025] Figure 12 yes Figure 11 A schematic diagram of the structure after being deflected at a certain angle.

[0026] The figure shows

[0027] Existing technical components include: 101, base plate; 102, temperature sensor; 103, upper shaft section; 104, rotating wheel; 105, secondary torsion spring; 106, cam; 107, linkage pin; 108, arc-shaped limiting hole; and 109, primary torsion spring.

[0028] The components of this invention are: 1. base plate; 2. upper shaft section; 3. lower shaft section; 4. cam; 5. notch; 6. rotating wheel; 6.1. upward flipping part; 6.2. upper convex plate; 7. linkage pin; 8. first arc-shaped limiting hole; 9. swing rod; 10. swing frame; 11. swing rod shaft; 12. swing frame shaft; 13. electromagnet; 14. compression spring; 15. protruding column; 16. reset tension spring; 17. primary torsion spring; 18. temperature sensor; 19. secondary torsion spring; 19.1. upper vertical section; 20. second arc-shaped limiting hole; 21. mounting plate; 22. third arc-shaped limiting hole. Detailed Implementation

[0029] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0030] like Figures 3 to 12As shown, the secondary actuator of the smoke exhaust fire damper of the present invention includes a base plate 1. The main shaft of the valve body passes through the base plate 1. The section of the main shaft above the base plate 1 is the upper shaft section 2, and the section below the base plate 1 is the lower shaft section 3. A cam 4 is fixed on the upper shaft section 2. The cam 4 has a notch 5. The upper shaft section 2 can also rotatably fit a rotating wheel 6 concentric with the cam 4. The rotating wheel 6 is located below the cam 4. The rotating wheel 6 is fixed with an upwardly protruding linkage pin 7. The cam 4 has a first arc-shaped limiting hole 8. The linkage pin 7 is inserted into the first arc-shaped limiting hole 8.

[0031] A swing rod 9 is rotatably mounted on the base plate 1 via a swing rod shaft 11, and a swing frame 10 is rotatably mounted on the swing frame shaft 12. An electromagnet 13 is also provided on the base plate 1. The spindle of the electromagnet 13 is connected to the head end of the swing rod 9. A compression spring 14 is fitted on the spindle, and the two ends of the compression spring 14 abut against the head end of the swing rod 9 and the housing of the electromagnet 13, respectively.

[0032] In the initial state, when the valve body is closed, the electromagnet 13 is de-energized and the spindle extends under the action of the compression spring 14. The latch at the tail end of the swing rod 9 engages with the head end of the swing frame 10, and the protrusion 15 in the middle section of the swing frame 10 engages with the notch 5 of the cam 4. A return spring is provided between the swing frame 10 and the base plate 1 to make the swing frame 10 move closer to the cam 4. The return spring is preferably a return tension spring 16, one end of which is fixed to the head end of the swing frame 10, and the other end is fixed to the electromagnet 13 fixing seat on the base plate 1. The upper shaft section 2 is also fitted with a primary torsion spring 17 for making the cam 4 rotate in the forward direction. The upper end of the primary torsion spring 17 is fixed to the upper shaft section 2, and the lower end is fixed to the upper protrusion 6.2 of the rotating wheel 6. The base plate 1 is also equipped with a temperature sensor 18, and the main shaft is also fitted with a secondary torsion spring 19 for making the rotating wheel 6 rotate in the opposite direction. The torque of the secondary torsion spring 19 is greater than that of the primary torsion spring 17 and it is located below the primary torsion spring 17. The upper end of the secondary torsion spring 19 is fixed to the rotating wheel 6. The upper part 6.1 of the rotating wheel 6 is hooked and abutted against the contact of the temperature sensor 18.

[0033] The base plate 1 also has a second arc-shaped limiting hole 20. The base plate 1 is provided with a downwardly protruding mounting plate 21. The main body of the secondary torsion spring 19 is fitted onto the lower shaft section 3 of the main shaft which is lower than the base plate 1. The upper vertical section 19.1 of the secondary torsion spring 19 passes through the second arc-shaped limiting hole 20 and is fixed to the rotating wheel 6. The lower end of the secondary torsion spring 19 is hooked to the mounting plate 21.

[0034] For ease of assembly, the upper vertical section 19.1 of the secondary torsion spring 19 and the rotating wheel 6 are fixed in the following way: a mounting hole is cut out on the rotating wheel 6, and the upper vertical section 19.1 passes through the mounting hole. In order to avoid the upper vertical section 19.1 passing through the mounting hole from rubbing against the cam 4, a third arc-shaped limiting hole 22 is also cut out on the cam 4. The upper vertical section 19.1 is accommodated in the third arc-shaped limiting hole 22. Since the circumferential movement range of the secondary torsion spring 19 and the rotating wheel 6 is about 90 degrees, the central angle of the third arc-shaped limiting hole 22 is set to 90 degrees to ensure that the secondary torsion spring 19 completely avoids the cam 4 and does not rub against it.

[0035] When the upper vertical section 19.1 of the secondary torsion spring 19 abuts against the first end of the second arc-shaped limiting hole 20, the upward-turning part 6.1 of the rotating wheel 6 passes over and hooks the contact of the temperature sensor 18, but there is a gap between it and the tail end of the swing frame 10; in other words, when the upper vertical section 19.1 abuts against the first end of the second arc-shaped limiting hole 20, the rotating wheel 6 is at its extreme position in the forward rotation direction, and at this moment the upward-turning part 6.1 of the rotating wheel 6 ensures that it does not touch the tail end of the swing frame 10. When the contact of the temperature sensor 18 retracts, the rotating wheel 6, which is no longer constrained by the contact, rotates in the reverse direction under the action of the secondary torsion spring 19 until the upper vertical section 19.1 of the secondary torsion spring 19 abuts against the tail end of the second arc-shaped limiting hole 20. At this time, the main shaft rotates exactly 90 degrees in the reverse direction, and the valve body closes again.

[0036] The rotating wheel 6, cam 4, swing arm 9, and swing frame 10 are all close to the base plate 1. The distance between the rotating wheel 6, cam 4, swing arm 9, and swing frame 10 and the base plate 1 is generally about 5mm, not exceeding 10mm.

[0037] Of course, since the rotation range of components such as the main shaft, cam 4, and rotary wheel 6 in this application is about 90 degrees, the central angle of the second arc-shaped limiting hole 20 and the first arc-shaped limiting hole 8 are both set to 90 degrees.

Claims

1. A secondary actuator for a smoke exhaust fire damper, comprising a base plate, a main shaft of a valve body passing through the base plate, a cam fixed to an upper shaft section of the main shaft above the base plate, the cam having a notch, a rotating wheel concentric with the cam being rotatably fitted to the upper shaft section, a protruding linkage pin fixed to the rotating wheel, and a first arc-shaped limiting hole hollowed out in the cam, the linkage pin being inserted into the first arc-shaped limiting hole; The base plate is rotatably mounted with a swing rod via a swing rod shaft and a swing frame via a swing frame shaft. An electromagnet is also provided on the base plate, and the core shaft of the electromagnet is connected to the head end of the swing rod. In the initial state, when the valve body is closed, the electromagnet is de-energized and the spindle extends. The latch at the end of the swing arm engages with the head of the swing frame. The protrusion in the middle section of the swing frame engages with the notch in the cam. A return spring is provided between the swing frame and the base plate to bring the swing frame closer to the cam. A primary torsion spring for rotating the cam in the forward direction is also fitted on the upper shaft section. The upper end of the primary torsion spring is fixed to the upper shaft section, and the lower end is fixed to the upper protrusion of the rotating wheel. A temperature sensor is also provided on the base plate. A secondary torsion spring for rotating the wheel in the reverse direction is fitted on the main shaft. The upper end of the secondary torsion spring is fixed to the rotating wheel. The upper part of the rotating wheel abuts against the contact of the temperature sensor. Its features are: The base plate also has a second arc-shaped limiting hole, and the base plate has a downward protruding mounting plate. The main body of the secondary torsion spring is fitted onto the lower shaft section of the main shaft which is lower than the base plate, while the upper vertical section of the secondary torsion spring passes through the second arc-shaped limiting hole and is fixed to the rotating wheel. The lower end of the secondary torsion spring is hooked to the mounting plate. When the upper vertical section of the secondary torsion spring abuts against the first end of the second arc-shaped limiting hole, the upward-turning part of the rotating wheel passes over and hooks the temperature sensor contact, but there is a gap between it and the tail end of the swing frame.

2. The secondary actuator of the smoke exhaust fire damper according to claim 1, characterized in that: The reset spring refers to the reset tension spring, one end of which is fixed to the head of the swing frame, and the other end is fixed to the electromagnet mounting base on the base plate.

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