High-reliable electric heating pipe sealing structure and method

[0026] Example 1

[0027] see Figure 2-Figure 3 On the one hand, the present invention provides a high-reliability electric heating pipe sealing structure, comprising an electric heating pipe body 1, a lead rod 5 is arranged in the electric heating pipe 1, and magnesium oxide powder is filled between the lead rod 5 and the electric heating pipe body 1 2. An insulating sealing device 3 is provided at the sealing portion of the electric heating tube body 1. The insulating sealing device 3 includes a sealing body, the upper end of the sealing body is provided with an upper opening 31, the lower end of the sealing body is provided with a lower opening 33, and the upper opening is 31 and the lower opening 33 are provided with a through middle channel 32, the outer side wall of the sealing body is provided with a step 34, the lead rod 5 passes through the middle channel 32 of the insulating sealing device 3, the middle channel There is a gap between 32 and the lead rod 5, and a sealant 4 is provided between the insulating sealing device 3 and the electric heating pipe body 1, and the electric heating pipe body 1 is connected with the step part 34 of the sealing body. The diameter of the upper opening 31 of the insulating sealing device 3 gradually decreases toward the direction of the middle channel 32 of the insulating sealing device 3, the diameter of the lower opening 33 decreases toward the direction 32 of the middle channel, and the smallest diameter of the lower opening 33 is connected with the largest part of the middle channel 32,

[0028] With the above arrangement, since the diameter of the upper opening 31 of the insulating sealing device 3 gradually decreases toward the direction of the middle channel 32 of the insulating sealing device 3, the upper opening 31 is funnel-shaped. By shrinking downward, there will be no gap between the contact surface of the sealing body and the sealant 4, and at the same time, the diameter of the lower opening 33 decreases toward the direction of the middle channel 32, so that the lower opening 33 presents a trumpet shape, and the gap between the lower opening 33 and the upper opening 31 is There is an intermediate channel 32 between, and the opening of the intermediate channel 32 is connected with the upper end opening and the lower end opening, so that the sealant forms a tower-shaped structure, eliminates the horizontal contact surface between the sealant 4 and the sealing body, and eliminates the air-tight condition, thereby The reliability of insulation voltage resistance is greatly improved, and at the same time, there is a gap between the middle channel 32 and the lead rod 5, so that the sealant 4 can be smoothly ascended to provide a channel, and the gap and air bubbles are eliminated, and the sealant 4 is bonded during the curing process. Good, no gaps or air bubbles will be generated. In addition, due to the existence of the middle channel 32, the lower opening 33 and the upper opening 31 on the sealing body, too much sealant 4 will overflow from the middle channel 32, preventing excessive sealant 4 from The overflow between the insulating sealing device 3 and the inside of the electric heating pipe body 1 causes the outer wall of the electric heating pipe to be polluted, and the electric heating pipe has good insulation and sealing performance.

[0029]The stepped portion 34 of the sealing body includes a first stepped portion 341 and a second stepped portion 342 . The first stepped portion 341 is connected to the inner side wall of the electric heating pipe body 1 , and the second stepped portion 342 is connected to the top surface of the electric heating pipe body 1 . In the above arrangement, since the step portion 34 is connected with the inner side wall and the top surface of the electric heating pipe body 1 , it is convenient to insert the sealing body into the electric heating pipe body 1 .

[0030] The depth of the upper opening 31 of the insulating sealing device 3 is smaller than the depth of the lower channel 33. The above setting, due to the increased depth of the lower channel 322, makes more sealant 4 enter the lower channel 322 and the middle channel 32, and a small amount enters the upper channel. Inside the opening 31 , too much sealant 4 is prevented from entering the upper opening 31 .

[0031] The diameter of the lower channel 322 gradually increases from the middle of the insulating sealing device 3 to the channel direction of the lower opening 33 . With the above arrangement, since the opening area of ​​the lower end surface of the lower channel 322 is large, the pressure is strong, and it is convenient for the sealant 4 to enter from the lower opening 33 in the middle channel 32.

[0032] The middle channel 32 is a cylindrical structure, and the above setting, due to the larger diameter of the middle channel 32, makes the sealant 4 entering the lower channel 322 transition through the middle channel 32, slowing down the flow rate entering the upper end opening 31, preventing excessive The sealant 4 quickly enters the upper opening 31 .

[0033] Example 2

[0034] like Figure 3-4 As shown, the difference between Embodiment 2 and Embodiment 1 is that the structure of the middle channel is different, and other structures are the same.

[0035] In this embodiment, the middle channel 32 includes a first middle channel 321 and a lower channel 322 in sequence along the upper end to the lower end of the insulating sealing device 3 . The upper end of the first middle channel 321 is communicated with the lower end of the upper opening 31 , and the first The lower end of the middle channel 321 is communicated with the upper end of the lower channel 322, and the lower end of the lower channel 322 is communicated with the upper end of the lower opening 33. The above arrangement divides the middle channel 32 into two parts, and the sealant entering the lower channel 322 passes through 4 When the middle passage 32 is formed, the lead rod and the insulating sealing device are well bonded by the sealant 4, so that the insulating sealing device and the pipe body are tightly combined.

[0036] Example 3

[0037] The present invention provides a sealing method for a high-reliability electric heating tube. The sealing structure of the high-reliability electric heating tube is shown in Embodiment 1 and Embodiment 2. The sealing method includes the following steps:

[0038] 1) Fill magnesium oxide powder 2 in the electric heating tube body 1;

[0039] 2) dig out d mm of magnesium oxide powder 2 at the end of the electric heating pipe body 1;

[0040] 3) Inject the sealant 4 into the electric heating pipe body 1 in advance, and make the injected sealant 4 away from the nozzle d/8mm of the electric heating pipe body 1; in this embodiment, d is 5-13 mm, and the above settings are easy to operate;

[0041] 4) Press the insulating sealing device 3 into the sealant 4, and the sealant 4 flows out from the gap between the intermediate channel 32 and the lead bar 5 to the upper end opening 31 to fill the gap between the sealing body and the lead bar 5.

[0042] In the above method, since the sealant 4 is first injected into the electric heating pipe body 1, and the injected sealant 4 is kept at a certain distance from the nozzle, then the insulating sealing device 3 is pressed into the sealant 4, so that the sealant 4 is removed from the The gap between the intermediate channel 32 and the lead rod 5 flows out and fills the gap between the sealing body and the lead rod 5, so that the sealant 4 can be smoothly ascended to provide a channel, eliminating the gap and air bubbles, and the sealant 4 is well bonded during the curing process. There will be gaps and air bubbles, and at the same time, because the diameter of the upper opening 31 of the insulating sealing device 3 gradually decreases toward the direction of the middle channel 32 of the insulating sealing device 3, the upper opening 31 presents a funnel shape. The sealant 4 at the place shrinks downward, so that no gap will be generated between the contact surface of the sealing body and the sealant 4. At the same time, the diameter of the lower opening 33 decreases toward the direction of the middle channel 32, so that the lower opening 33 presents a trumpet shape. In addition, the lower opening 33 There is an intermediate channel 32 between the upper opening 31, and the opening of the intermediate channel 32 is connected with the upper end opening and the lower end opening, so that the sealant 4 forms a tower-shaped structure, eliminating the horizontal contact surface between the sealant 4 and the sealing body, eliminating the The condition of air-tight is achieved, thereby greatly improving the reliability of insulation voltage resistance, and at the same time, there is a gap between the middle channel 32 and the lead rod 5. In addition, due to the existence of the middle channel 32, the lower opening 33 and the upper opening 31 on the sealing body, Therefore, too much sealant 4 will overflow from the intermediate channel 32, preventing excessive sealant 4 from overflowing between the insulating sealing device 3 and the interior of the electric heating pipe body 1, causing pollution of the outer wall of the electric heating pipe, and the insulation and sealing performance of the electric heating pipe. it is good.

[0043] The above method also includes: step 5) If the sealant 4 does not fill the upper end opening, fill the upper end opening with the sealant 4, and fill the upper end opening by means of post-filling, thereby ensuring the reliability of filling the upper end opening.