A method for sealing a vacuum chamber of a fire alarm switch

Abstract

The application discloses a vacuum chamber sealing method for a fire alarm switch device. The inner cavity of the vacuum chamber is vacuumized by a vacuum device connected with a vacuum joint, so that the inner cavity is kept in a vacuum state, and then the internal part of the fire alarm switch device is kept in a vacuum state. Then, the air pipe of the fire alarm switch device is segmented punched by a movable punch and a fixed punch, so that the air pipe is plastically deformed and adhered, and then the air pipe is sealed in a vacuum environment, so that the vacuum degree requirement of the internal part of the fire alarm switch device is guaranteed.

Description

Technical Field

[0001] This invention belongs to the technical field of sealing fire alarm switches, specifically relating to a method for sealing the vacuum chamber of a fire alarm switch. Background Technology

[0002] In the production process of aircraft engine switches, it is necessary to evacuate the internal cavity of the fire alarm switch before sealing the vent pipe connected to the inside of the switch to ensure a vacuum state. In existing technology, due to the small diameter of the vent pipe, it is difficult to effectively evacuate the internal cavity of the fire alarm switch directly through the vent pipe. This results in gas inevitably entering the interior of the fire alarm switch during the stamping and sealing process of the vent pipe, affecting the vacuum level inside the switch.

[0003] Therefore, in view of the problem that it is difficult to ensure the vacuum level inside the fire alarm switch during the sealing operation of the vent pipe of the fire alarm switch in the prior art, the present invention discloses a method for sealing the vacuum chamber of the fire alarm switch. Summary of the Invention

[0004] This invention discloses a method for sealing the vacuum chamber of a fire alarm switch, which can ensure that the vent pipe of the fire alarm switch is plastically stamped and sealed in a vacuum environment, thus ensuring a tight seal of the vent pipe of the fire alarm switch.

[0005] This invention is achieved through the following technical solution: A method for sealing a vacuum chamber of a fire alarm switch, based on a vacuum chamber sealing device, the vacuum chamber sealing device including a vacuum chamber 2 with an inner cavity, a vacuum connector 1 and a fire alarm switch 8 respectively provided at both ends of the inner cavity, a vent pipe of the fire alarm switch 8 extending into the interior of the inner cavity, and an adjustable elastic seal is filled between the outer side of the vent pipe and the inner wall of the inner cavity; a movable punch 4 and a fixed punch 9 are provided on the upper and lower sides of the inner cavity, and the vent pipe is located between the movable punch 4 and the fixed punch 9, including the following steps: Step 1: Insert the vent 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 tightly fills the area between the outer side of the vent pipe and the inner cavity. Step 2: Connect vacuum connector 1 to the vacuum machine, use the vacuum machine to evacuate the inner cavity, and check the vacuum level in the inner cavity. If the vacuum level in the inner cavity meets the standard, proceed to step 3. Step 3: Apply pressure to the vent tube using the movable punch 4, and work with the fixed punch 9 to cause the vent tube to undergo plastic deformation and adhere, thereby sealing the vent tube. To better realize the present invention, the punching end of the movable punch 4 is further provided with a pressure sensor, which detects the pressure applied by the movable punch 4 to the vent pipe.

[0006] To better realize the present invention, step 3 further includes: Step 3.1: Apply gradually increasing pressure to the movable punch 4 using a stamping machine to stamp the vent pipe for the first time period, and use a vacuum machine to perform vacuuming of the inner cavity with the first suction power during the first time period. Step 3.2: When the pressure increases to the calibrated pressure, maintain the calibrated pressure and pressurize the vent pipe for a second time period. During the second time period, use a vacuum machine with the second suction power to perform a vacuuming operation on the inner cavity. Step 3.3: Loosen the adjustable elastic seal, rotate the vent pipe 180°, tighten the adjustable elastic seal again, and then apply repressurization pressure to the vent pipe through the movable punch 4.

[0007] To better realize the present invention, the pressure applied in the first time period increases linearly with respect to time, and the calibrated pressure is less than the allowable shear pressure of the ventilator.

[0008] To better realize the present invention, the additional pressure is one-third to one-half of the rated pressure.

[0009] To better realize the present invention, the second suction power is further 1.2-1.5 times the first suction power.

[0010] To better realize the present invention, in step 2, after the inner cavity is evacuated by the vacuum machine, the vacuum state of the inner cavity is maintained for at least 2 minutes, and then the vacuum degree of the inner cavity is detected. If the vacuum degree of the inner cavity remains unchanged, the process proceeds to step 3; if the vacuum degree of the inner cavity changes, the compression state of the adjustable elastic seal is adjusted, and the evacuation operation of the inner cavity is repeated.

[0011] Compared with the prior art, the present invention has the following advantages and beneficial effects: This invention inserts the vent pipe of a fire alarm switch into the inner cavity of a vacuum chamber, and fills and seals the area between the vent pipe and the inner cavity with an adjustable elastic seal. At the same time, a vacuum machine connected to a vacuum connector evacuates the inner cavity to a vacuum state, thereby ensuring that the inside of the fire alarm switch is evacuated to a vacuum state. Then, pressure is applied to the upper and lower sides of the vent pipe by a movable punch and a fixed punch, causing the vent pipe to undergo plastic deformation and adhere and seal in the vacuum environment, ultimately ensuring the vacuum level requirement inside the fire alarm switch. Attached Figure Description

[0012] Figure 1A schematic diagram of the sealing device for the vacuum chamber of a fire alarm switch. Figure 2 This is a schematic diagram of the vacuum chamber. Figure 3 This is a schematic diagram of the structure of the movable punch; Figure 4 This is the front view of the fixed punch; Figure 5 This is a side view of the fixed punch.

[0013] Wherein: 1-vacuum connector; 2-vacuum chamber; 3-reset 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-circular arc groove. Detailed Implementation

[0014] Example 1: This embodiment provides a method for sealing the vacuum chamber of a fire alarm switch, which is based on a vacuum chamber sealing device. The vacuum chamber sealing device includes a vacuum chamber 2 with an inner cavity. A vacuum connector 1 is provided at one end of the inner cavity, and a fire alarm switch 8 is provided at the other end of the inner cavity. The vent pipe of the fire alarm switch 8 extends into the interior of the inner cavity, and an adjustable elastic seal is provided between the outer side of the vent pipe and the inner cavity. A movable punch 4 and a fixed punch 9 are provided on the upper and lower sides of the inner cavity, respectively, and the vent pipe is located between the movable punch 4 and the fixed punch 9.

[0015] like Figure 1 , Figure 2 As shown, the vacuum chamber 2 has an inner cavity. A vacuum connector 1 is threadedly connected to the left end of the inner cavity, and a vent pipe for the fire alarm switch 8 is inserted into the right end. An adjustable elastic seal is installed between the outer wall of the vent pipe and the inner wall of the inner cavity. By applying pressure to the adjustable elastic seal, it deforms and tightly fills the area between the outer wall of the vent pipe and the inner wall of the inner cavity, thus sealing the inner cavity. A movable punch 4 and a fixed punch 9 are respectively installed on the upper and lower sides of the inner cavity. The fixed punch 9 supports and positions the vent pipe, while the movable punch 4 applies pressure to the vent pipe under the action of a press. The vacuum connector 1 is connected to a vacuum machine to evacuate the inner cavity to a vacuum state. Then, pressure is applied to the vent pipe by the movable punch 4, causing the vent pipe to undergo plastic deformation and adhere in the vacuum environment, thus sealing the vent pipe.

[0016] Specifically, the following steps are included: Step 1: Insert the vent 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 tightly fills the area between the outer side of the vent pipe and the inner cavity. Step 2: Connect vacuum connector 1 to the vacuum machine, use the vacuum machine to evacuate the inner cavity, and check the vacuum level in the inner cavity. If the vacuum level in the inner cavity meets the standard, proceed to step 3. Step 3: Apply pressure to the vent tube using the movable punch 4, and work with the fixed punch 9 to cause the vent tube to undergo plastic deformation and adhere, thereby sealing the vent tube.

[0017] Step 3 specifically includes: Step 3.1: Apply gradually increasing pressure to the movable punch 4 using a stamping machine to stamp the vent pipe for the first time period, and use a vacuum machine to perform vacuuming of the inner cavity with the first suction power during the first time period. Step 3.2: When the pressure increases to the calibrated pressure, maintain the calibrated pressure and pressurize the vent pipe for a second time period. During the second time period, use a vacuum machine with the second suction power to perform a vacuuming operation on the inner cavity. Step 3.3: Loosen the adjustable elastic seal, rotate the vent pipe 180°, tighten the adjustable elastic seal again, and then apply repressurization pressure to the vent pipe through the movable punch 4.

[0018] Furthermore, in step 2, after evacuating the inner cavity using a vacuum machine, the vacuum state of the inner cavity is maintained for at least 2 minutes, and then the vacuum degree of the inner cavity is detected. If the vacuum degree of the inner cavity remains unchanged, proceed to step 3; if the vacuum degree of the inner cavity changes, the compression state of the adjustable elastic seal is adjusted, and the evacuation operation of the inner cavity is repeated.

[0019] Furthermore, a pressure sensor is provided at the punching end of the movable punch 4 to detect the pressure applied by the movable punch 4 to the vent pipe.

[0020] Furthermore, the pressure applied during the first time period increases linearly with respect to time, and the calibrated pressure is less than the allowable shear pressure of the ventilator.

[0021] Furthermore, the repressurization pressure is one-third to one-half of the calibrated pressure.

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

[0023] Example 2: This embodiment is a further optimization based on Embodiment 1, such as... Figure 1 As shown, the adjustable elastic seal includes an elastic sealing bushing 6 and a clamping nut 7. The elastic sealing bushing 6 is filled and disposed inside the inner cavity. The end of the elastic sealing bushing 6 away from the vacuum connector 1 is threadedly fitted with the clamping nut 7. Both the elastic sealing bushing 6 and the clamping nut 7 have through holes at their centers for the vent pipe of the fire alarm switch 8 to pass through.

[0024] By rotating the clamping nut 7, the clamping nut 7 compresses the elastic sealing bushing 6, causing the elastic sealing bushing 6 to deform elastically and fill the area between the vent pipe and the inner cavity, ultimately achieving a seal on the inner cavity. By adjusting the rotation angle of the clamping nut 7, the clamping force of the clamping nut 7 on the elastic sealing bushing 6 can be adjusted, thereby adjusting the degree of elastic deformation of the elastic sealing bushing 6.

[0025] Furthermore, the through hole at the center of the elastic sealing bushing 6 is interference-fitted with the vent pipe to ensure that when the elastic sealing bushing 6 is subjected to elastic deformation under pressure, the inner wall of the through hole can fit tightly with the outer wall of the vent pipe, thus ensuring the sealing of the inner cavity.

[0026] Furthermore, the diameter of the through hole at the center of the clamping nut 7 is larger than the outer diameter of the vent pipe to avoid interference between the clamping nut 7 and the vent pipe when the clamping nut 7 rotates.

[0027] The other parts of this embodiment are the same as those in Embodiment 1, so they will not be described again.

[0028] Example 3: This embodiment is a further optimization based on 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. A return spring 3 is sleeved on the outside of the movable punch 4.

[0029] As shown in the figure, the upper end of the movable punch 4 is provided with a pressure-receiving surface. The press applies downward pressure to this surface, causing the movable punch 4 to move downwards along the upper stepped hole. Simultaneously, the return spring 3 is compressed. The downward pressure of the movable punch 4 applies pressure to the vent pipe in the inner cavity, causing it to plastically deform and seal. After the press releases the pressure, the return spring 3 rebounds, causing the movable punch 4 to move upwards to reset.

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

[0031] Furthermore, at least one set of sealing rings 5 ​​is provided between the outer side 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 cavity is ensured.

[0032] The other parts of this embodiment are the same as those in Embodiment 1 or 2 above, so they will not be described again.

[0033] Example 4: This embodiment is a further optimization based on any one of embodiments 1-3 above, such as... Figure 4 and Figure 5 As shown, a lower stepped hole is provided on the lower side of the inner cavity, and a fixed punch 9 is installed in the lower stepped hole.

[0034] Furthermore, at least one set of sealing rings 5 ​​is provided between the outer side 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 cavity is ensured.

[0035] Furthermore, the stamping end of the fixed punch 9 is provided with a V-shaped groove 200, and one side of the V-shaped groove 200 is provided with an arc groove 300 perpendicular to the V-shaped groove 200. The outline of the arc groove 300 corresponds to the outer outline of the vent pipe to achieve positioning of the vent pipe. The V-shaped groove 200 is perpendicular to the axis of the vent pipe, and works with the V-shaped protrusion 100 to plastically compress the upper and lower sides of the vent pipe, ensuring that the vent pipe is plastically deformed and adhered for closure.

[0036] The other parts of this embodiment are the same as any one of the embodiments 1-3 above, so they will not be described again.

[0037] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications or equivalent changes 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 a vacuum chamber of a fire alarm switch, based on a vacuum chamber sealing device, the vacuum chamber sealing device comprising a vacuum chamber (2) with an inner cavity, wherein a vacuum connector (1) and a fire alarm switch (8) are respectively provided at both ends of the inner cavity, the vent pipe of the fire alarm switch (8) extends into the interior of the inner cavity, and an adjustable elastic seal is filled between the outer side of the vent pipe and the inner wall of the inner cavity; a movable punch (4) and a fixed punch (9) are provided on the upper and lower sides of the inner cavity, and the vent pipe is located between the movable punch (4) and the fixed punch (9), characterized in that, Includes the following steps: Step 1: Insert the vent 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 tightly fills the area between the outer side of the vent pipe and the inner cavity. Step 2: Connect the vacuum connector (1) to the vacuum machine, and use the vacuum machine to evacuate the inner cavity. Check the vacuum level in the inner cavity. If the vacuum level in the inner cavity meets the standard, proceed to step 3. Step 3: Apply pressure to the vent pipe with the movable punch (4) and cooperate with the fixed punch (9) to make the vent pipe plastically deform and stick together, thereby sealing the vent pipe.

2. The method for sealing the vacuum chamber of a fire alarm switch according to claim 1, characterized in that, The punching end of the movable punch (4) is equipped with a pressure sensor, which detects the pressure applied to the vent pipe by the movable punch (4).

3. The method for sealing the vacuum chamber of a fire alarm switch according to claim 2, characterized in that, Step 3 specifically includes: Step 3.1: Apply gradually increasing pressure to the movable punch (4) by the press to press the vent pipe for the first time period, and use the vacuum machine to perform vacuuming operation on the inner cavity with the first suction power during the first time period; Step 3.2: When the pressure increases to the calibrated pressure, maintain the calibrated pressure and pressurize the vent pipe for a second time period. During the second time period, use a vacuum machine with the second suction power to perform a vacuuming operation on the inner cavity. Step 3.3: Loosen the adjustable elastic seal, rotate the vent pipe 180°, tighten the adjustable elastic seal again, and then apply pressure to the vent pipe through the movable punch (4) to repressurize it.

4. The method for sealing the vacuum chamber of a fire alarm switch according to claim 3, characterized in that, The pressure applied during the first time period increases linearly with respect to time, and the calibrated pressure is less than the allowable shear pressure of the ventilator.

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

6. The method for sealing the 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 the vacuum chamber of a fire alarm switch according to any one of claims 1-6, characterized in that, In step 2, after evacuating the inner cavity using a vacuum machine, the vacuum state of the inner cavity is maintained for at least 2 minutes. Then, the vacuum degree of the inner cavity is detected. If the vacuum degree of the inner cavity remains unchanged, proceed to step 3. If the vacuum degree of the inner cavity changes, the compression state of the adjustable elastic seal is adjusted, and the evacuation operation of the inner cavity is repeated.

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