Sealing method for vacuum chamber of fire alarm switch

Abstract

The invention discloses a method for sealing a vacuum chamber of a fire alarm switch, which comprises the following steps of: vacuumizing an inner cavity of the vacuum chamber through a vacuum device connected with a vacuum joint, so that the inner cavity is kept in a vacuum state, and further ensuring that the interior of the fire alarm switch is kept in a vacuum state; and then the movable punch and the fixed punch are matched to punch the breather pipe of the fire alarm switch in a segmented manner, so that the breather pipe is plastically deformed and adhered, the breather pipe is sealed in a vacuum environment, and the requirement for the vacuum degree in the fire alarm switch can be met.

Description

Technical Field

[0001] The invention belongs to the technical field of sealing of fire alarm switch devices, and particularly relates to a method for sealing a vacuum chamber of a fire alarm switch device. Background Art

[0002] During the production process of an aero-engine switch device, after evacuating the interior of the fire alarm switch device, the ventilation pipe connected to the interior of the fire alarm switch device needs to be sealed to ensure the vacuum state inside the fire alarm switch device. In the prior art, due to the small diameter of the ventilation pipe of the fire alarm switch device, it is difficult to directly evacuate the interior of the fire alarm switch device effectively through the ventilation pipe, resulting in gas always entering the interior of the fire alarm switch device during the stamping and sealing operation of the ventilation pipe, affecting the vacuum degree inside the fire alarm switch device.

[0003] Therefore, aiming at the problem that it is difficult to ensure the vacuum degree inside the fire alarm switch device during the sealing operation of the ventilation pipe of the fire alarm switch device in the prior art, the invention discloses a method for sealing a vacuum chamber of a fire alarm switch device. Summary of the Invention

[0004] The invention discloses a method for sealing a vacuum chamber of a fire alarm switch device, which can ensure plastic stamping and sealing operation of the ventilation pipe of the fire alarm switch device in a vacuum environment and ensure tight sealing of the ventilation pipe of the fire alarm switch device.

[0005] The invention is realized by the following technical solutions: A method for sealing a vacuum chamber of a fire alarm switch device is realized based on a vacuum chamber sealing device. The vacuum chamber sealing device includes a vacuum chamber 2 with an inner cavity. A vacuum joint 1 and a fire alarm switch device 8 are respectively arranged at two ends of the inner cavity. The ventilation pipe of the fire alarm switch device 8 extends into the interior of the inner cavity, and an adjustable elastic seal is filled between the outer side of the ventilation pipe and the inner wall of the inner cavity. An active punch 4 and a fixed punch 9 are arranged on the upper and lower sides of the inner cavity. The ventilation pipe is located between the active punch 4 and the fixed punch 9, and the method includes the following steps: Step 1: Insert the ventilation pipe of the fire alarm switch device 8 into the inner cavity of the vacuum chamber 2, and squeeze the adjustable elastic seal so that the adjustable elastic seal densely fills the area between the outer side of the ventilation pipe and the inner cavity. Step 2: Connect the vacuum joint 1 to a vacuum machine, evacuate the inner cavity through the vacuum machine, detect the vacuum degree in the inner cavity, and if the vacuum degree in the inner cavity meets the standard, go to Step 3. Step 3: Apply pressure to the ventilation pipe through the active punch 4, and cooperate with the fixed punch 9 to make the ventilation pipe undergo plastic deformation and adhesion to achieve sealing of the ventilation pipe. In order to better implement the present invention, further, a pressure sensor is provided at the stamping end of the movable punch 4 to detect the pressure exerted by the movable punch 4 on the ventilation pipe.

[0006] In order to better implement the present invention, further, step 3 specifically includes: Step 3.1: Apply a gradually increasing pressure to the movable punch 4 through a stamping machine to stamp the ventilation pipe for a first time period, and perform a vacuuming operation on the inner cavity with a first suction power by a vacuum machine during the first time period; Step 3.2: When the pressure increases to the calibrated pressure, maintain the calibrated pressure, stamp the ventilation pipe for a second time period, and perform a vacuuming operation on the inner cavity with a second suction power by a vacuum machine during the second time period; Step 3.3: Loosen the adjustable elastic seal, rotate the ventilation pipe 180°, re - compress the adjustable elastic seal, and then apply a repressing pressure to the ventilation pipe through the movable punch 4 for repressing.

[0007] In order to better implement the present invention, further, the pressure applied during the first time period increases linearly in direct proportion to time, and the calibrated pressure is less than the allowable shear pressure of the ventilation pipe.

[0008] In order to better implement the present invention, further, the repressing pressure is one - third to one - half of the calibrated pressure.

[0009] In order to better implement the present invention, further, the second suction power is 1.2 - 1.5 times the first suction power.

[0010] In order to better implement the present invention, further, in step 2, after vacuuming the inner cavity by a vacuum machine, maintain the vacuum state of the inner cavity for at least 2 min, and then detect the vacuum degree of the inner cavity. If the vacuum degree of the inner cavity remains unchanged, proceed to step 3; if the vacuum degree of the inner cavity changes, adjust the compression state of the adjustable elastic seal and then re - perform the vacuuming operation on the inner cavity.

[0011] Compared with the prior art, the present invention has the following advantages and beneficial effects: The present invention inserts the ventilation pipe of the fire alarm switch into the inner cavity of the vacuum chamber, fills and seals the area between the ventilation pipe and the inner cavity through an adjustable elastic seal, and at the same time sucks the inner cavity to a vacuum state by a vacuum machine connected to a vacuum joint, thereby ensuring that the inside of the fire alarm switch is sucked to a vacuum state. Then, pressure is applied to the upper and lower sides of the ventilation pipe by a movable punch and a fixed punch, so that the ventilation pipe undergoes plastic deformation and adhesion sealing in a vacuum environment, ultimately ensuring the vacuum degree requirement inside the fire alarm switch. Description of the Drawings

[0012] Figure 1Schematic structural diagram of the sealing device for the vacuum chamber of the fire alarm switch Figure 2 Schematic structural diagram of the vacuum chamber Figure 3 Schematic structural diagram of the movable punch Figure 4 Front view of the fixed punch Figure 5 Side view of the fixed punch

[0013] Wherein: 1 - vacuum connector; 2 - vacuum chamber; 3 - return spring; 4 - movable punch; 5 - sealing ring; 6 - elastic sealing bushing; 7 - compression nut; 8 - fire alarm switch; 9 - fixed punch; 100 - V-shaped protrusion; 200 - V-shaped groove; 300 - arc groove Specific implementation mode

[0014] Example 1 A method for sealing the vacuum chamber of a fire alarm switch in this embodiment is realized based on the vacuum chamber sealing device. The vacuum chamber sealing device includes a vacuum chamber 2 with an inner cavity. One end of the inner cavity is provided with a vacuum connector 1, and the other end of the inner cavity is provided with a fire alarm switch 8. The ventilation pipe of the fire alarm switch 8 extends into the interior of the inner cavity, and an adjustable elastic seal is arranged between the outer side of the ventilation pipe and the inner cavity; a movable punch 4 and a fixed punch 9 are correspondingly arranged on the upper and lower sides of the inner cavity, and the ventilation pipe is located between the movable punch 4 and the fixed punch 9

[0015] As Figure 1 、 Figure 2 shown, an inner cavity is arranged inside the vacuum chamber 2. A vacuum connector 1 is threadedly connected to the left end of the inner cavity, and the ventilation pipe of the fire alarm switch 8 is inserted into the right end of the inner cavity. An adjustable elastic seal is filled between the outer wall of the ventilation pipe and the inner wall of the inner cavity. By applying pressure to the adjustable elastic seal, the adjustable elastic seal elastically deforms to densely fill the area between the outer wall of the ventilation pipe and the inner wall of the inner cavity, thereby realizing the sealing of the inner cavity. A movable punch 4 and a fixed punch 9 are respectively and correspondingly arranged on the upper and lower sides of the inner cavity. The fixed punch 9 is used to support and position the ventilation pipe, and the movable punch 4 applies pressure to the ventilation pipe under the action of a punching machine. Connect the vacuum connector 1 to a vacuum machine to suck the inner cavity to a vacuum state, and then apply pressure to the ventilation pipe through the movable punch 4, so that the ventilation pipe undergoes plastic deformation and adhesion in a vacuum environment to realize the sealing of the ventilation pipe

[0016] Specifically, it includes the following steps Step 1: Insert the ventilation pipe of the fire alarm switch 8 into the inner cavity of the vacuum chamber 2, and squeeze the adjustable elastic seal so that the adjustable elastic seal densely fills the area between the outer side of the ventilation pipe and the inner cavity Step 2: Connect the vacuum joint 1 to the vacuum machine, evacuate the inner cavity through the vacuum machine, detect the vacuum degree in the inner cavity, and if the vacuum degree in the inner cavity meets the standard, proceed to Step 3; Step 3: Apply pressure to the ventilation pipe through the movable punch 4, and cooperate with the fixed punch 9 to cause plastic deformation and adhesion of the ventilation pipe, thereby realizing the sealing of the ventilation pipe.

[0017] The specific steps of Step 3 include: Step 3.1: Apply gradually increasing pressure to the movable punch 4 through a stamping machine, stamp the ventilation pipe for a first time period, and evacuate the inner cavity through the vacuum machine at a first suction power during the first time period; Step 3.2: When the pressure increases to the calibrated pressure, maintain the calibrated pressure, stamp the ventilation pipe for a second time period, and evacuate the inner cavity through the vacuum machine at a second suction power during the second time period; Step 3.3: Loosen the adjustable elastic seal, rotate the ventilation pipe 180°, re-tighten the adjustable elastic seal, and then apply a re-pressing pressure to the ventilation pipe through the movable punch 4 for re-pressing.

[0018] Further, in Step 2, after evacuating the inner cavity through the vacuum machine, maintain the vacuum state of the inner cavity for at least 2 minutes, then detect the vacuum degree of the inner cavity. If the vacuum degree of the inner cavity remains unchanged, proceed to Step 3; if the vacuum degree of the inner cavity changes, adjust the pressing state of the adjustable elastic seal and then re-perform the evacuation operation of the inner cavity.

[0019] Further, a pressure sensor is provided at the stamping end of the movable punch 4 to detect the pressure applied by the movable punch 4 to the ventilation pipe.

[0020] Further, the pressure applied during the first time period increases linearly in direct proportion to time, and the calibrated pressure is less than the allowable shear pressure of the ventilation pipe.

[0021] Further, the re-pressing pressure is one-third to one-half of the calibrated pressure.

[0022] Further, the second suction power is 1.2 - 1.5 times the first suction power.

[0023] Example 2: This example is further optimized on the basis of Example 1, as Figure 1 shown, the adjustable elastic seal includes an elastic sealing bushing 6 and a compression nut 7. The elastic sealing bushing 6 is filled and arranged inside the inner cavity. One end of the elastic sealing bushing 6 away from the vacuum joint 1 is threadedly fitted with a compression nut 7. Through holes for the ventilation pipe of the fire alarm switch 8 are provided at the centers of the elastic sealing bushing 6 and the compression nut 7.

[0024] By rotating the compression nut 7, the compression nut 7 squeezes the elastic sealing bushing 6, causing the elastic sealing bushing 6 to elastically deform and fill the area between the ventilation pipe and the inner cavity, ultimately achieving the sealing of the inner cavity. By adjusting the rotation angle of the compression nut 7, the pressing force of the compression nut 7 on the elastic sealing bushing 6 is adjusted, and further the elastic deformation degree of the elastic sealing bushing 6 is adjusted.

[0025] Furthermore, the through hole at the center of the elastic sealing bushing 6 is connected with the ventilation pipe by interference fit, ensuring that when the elastic sealing bushing 6 is elastically deformed under pressure, the inner wall of the through hole can closely fit with the outer wall of the ventilation pipe, ensuring the sealing of the inner cavity.

[0026] Furthermore, the diameter of the through hole at the center of the compression nut 7 is larger than the outer diameter of the ventilation pipe, avoiding interference between the compression nut 7 and the ventilation pipe when the compression nut 7 rotates.

[0027] Other parts of this embodiment are the same as those of Embodiment 1, so they will not be elaborated here.

[0028] Embodiment 3: This embodiment is further optimized on the basis of the above Embodiment 1 or 2, such as Figure 3 As shown, an upper stepped hole is provided on the upper side of the inner cavity, and a movable punch 4 is slidably installed in the upper stepped hole, and a return spring 3 is sleeved outside the movable punch 4.

[0029] As shown in the figure, a pressure-receiving surface is provided at the upper end of the movable punch 4. By applying a downward pressure to the pressure-receiving surface by a stamping machine, the movable punch 4 moves downward along the upper stepped hole, and at the same time compresses the return spring 3 so that the return spring 3 is in a compressed state. The movable punch 4 presses down to apply pressure to the ventilation pipe in the inner cavity, causing the ventilation pipe to plastically deform and adhere to be sealed. After the pressure of the puncher is removed, the return spring 3 rebounds to drive the movable punch 4 to move upward to achieve reset.

[0030] Furthermore, a V-shaped protrusion 100 is provided at the stamping head end of the movable punch 4, and an arc portion is provided at one end of the V-shaped protrusion 100 in contact with the ventilation pipe, and the V-shaped protrusion 100 is perpendicular to the axis of the ventilation pipe. By providing the arc portion, it is ensured that the contact between the V-shaped protrusion 100 and the pipe wall of the ventilation pipe is smooth, ensuring that sufficient pressure is applied to the ventilation pipe without directly cutting off the ventilation pipe.

[0031] Furthermore, at least one set of sealing rings 5 is provided between the outer side surface of the movable punch 4 and the inner wall of the upper stepped hole. By providing the sealing rings 5, the vacuum degree inside the inner cavity is ensured.

[0032] Other parts of this embodiment are the same as those of the above Embodiment 1 or 2, so they will not be elaborated here.

[0033] Example 4: This example further optimizes on the basis of any one of the above Examples 1-3, such as Figure 4 and Figure 5 shown, a lower stepped hole is provided on the lower side of the inner cavity, and a fixed punch 9 is fitted and installed in the lower stepped hole.

[0034] Furthermore, at least one set of sealing rings 5 is provided between the outer side surface of the fixed punch 9 and the inner wall of the lower stepped hole. By providing the sealing rings 5, the vacuum degree inside the inner cavity is ensured.

[0035] Furthermore, a V-shaped groove 200 is provided at the stamping end of the fixed punch 9, and an arc groove 300 perpendicular to the V-shaped groove 200 is provided on one side of the V-shaped groove 200. The contour of the arc groove 300 corresponds to the outer contour of the ventilation pipe to achieve the positioning of the ventilation pipe. The V-shaped groove 200 is perpendicular to the axis of the ventilation pipe and cooperates with the V-shaped protrusion 100 to plastically extrude the upper and lower sides of the ventilation pipe to ensure that the ventilation pipe is plastically deformed and adhesively sealed.

[0036] Other parts of this example are the same as any one of the above Examples 1-3, so they will not be described in detail.

[0037] The above is only a preferred embodiment of the present invention, and does not impose any form of limitation on the present invention. Any simple modification or equivalent change made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A method for sealing the vacuum chamber of a fire alarm switch, which is realized based on a vacuum chamber sealing device. The vacuum chamber sealing device includes a vacuum chamber (2) with an inner cavity. At both ends of the inner cavity, a vacuum joint (1) and a fire alarm switch (8) are respectively arranged. The air vent pipe of the fire alarm switch (8) extends to the inside of the inner cavity, and an adjustable elastic seal is filled between the outer side of the air vent pipe and the inner wall of the inner cavity. An active punch (4) and a fixed punch (9) are arranged on the upper and lower sides of the inner cavity, and the air vent pipe is located between the active punch (4) and the fixed punch (9). The method is characterized in that, It includes the following steps: Step 1: Insert the ventilation pipe of the fire alarm switch (8) into the inner cavity of the vacuum chamber (2), and squeeze the adjustable elastic seal, so that the adjustable elastic seal densely fills the area between the outer side of the ventilation pipe and the inner cavity; Step 2: Connect the vacuum joint (1) to the vacuum machine, perform a vacuuming operation on the inner cavity through the vacuum machine, detect the vacuum degree in the inner cavity, and if the vacuum degree in the inner cavity meets the standard, proceed to Step 3; Step 3: Apply pressure to the ventilation pipe through the movable punch (4), and cooperate with the fixed punch (9) to make the ventilation pipe undergo plastic deformation and adhesion, so as to seal the ventilation pipe.

2. The method for sealing the vacuum chamber of a fire alarm switch according to claim 1, characterized in that, A pressure sensor is arranged at the stamping end of the movable punch (4), and the pressure applied by the movable punch (4) to the ventilation pipe is detected through the pressure sensor.

3. A method for sealing a vacuum chamber of a fire alarm switch according to claim 2, characterized in that, The specific content of Step 3 includes: Step 3.1: Apply a gradually increasing pressure to the movable punch (4) through a stamping machine, stamp the ventilation pipe for a first time period, and perform a vacuuming operation on the inner cavity through the vacuum machine at a first suction power during the first time period; Step 3.2: When the pressure increases to the calibration pressure, maintain the calibration pressure, stamp the ventilation pipe for a second time period, and perform a vacuuming operation on the inner cavity through the vacuum machine at a second suction power during the second time period; Step 3.3: Loosen the adjustable elastic seal, rotate the ventilation pipe 180°, re-press the adjustable elastic seal, and then apply a re-pressing pressure to the ventilation pipe through the movable punch (4) for re-pressing.

4. A method for sealing a vacuum chamber of a fire alarm switch according to claim 3, characterized in that, The pressure applied during the first time period increases linearly in direct proportion to time, and the calibration pressure is less than the allowable shear pressure of the ventilation pipe.

5. A method for sealing the vacuum chamber of a fire alarm switch according to claim 4, characterized in that, The re-pressing pressure is one-third to one-half of the calibration pressure.

6. A method for sealing a vacuum chamber of a fire alarm switch according to claim 5, characterized in that, The second suction power is 1.2 - 1.5 times the first suction power.

7. A method for sealing a vacuum chamber of a fire alarm switch according to any one of claims 1-6, characterized in that, In Step 2, after vacuuming the inner cavity through the vacuum machine, maintain the vacuum state of the inner cavity for at least 2 minutes, and then detect the vacuum degree of the inner cavity. If the vacuum degree of the inner cavity remains unchanged, proceed to Step 3; if the vacuum degree of the inner cavity changes, adjust the pressing state of the adjustable elastic seal and then re-perform the vacuuming operation on the inner cavity.

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