阅读说明：本技术 一种高可靠性电热管密封结构及方法 (High-reliability electric heating tube sealing structure and method ) 是由 黄昊 于 2019-10-24 设计创作，主要内容包括：一种高可靠性电热管密封结构及方法,电热管管体内设有引棒,引棒与管体之间填充有氧化镁粉,电热管管体的封口处设有一种绝缘密封装置,绝缘密封装置分为上部开口、中部通道、下部通道、下部开口,引棒贯穿所述密封口装置的中部通道,绝缘密封装置与电热管管体之间设有密封胶,绝缘密封装置上部外直径大于电热管管体封口处外壁直径,下部外直径小于电热管管体内壁直径,上部开口直径往密封口装置中部逐渐减小,下部通道直径往绝缘密封装置中部逐渐减小,下部开口位于下部通道下方,下部开口直径逐渐往下部通道减小,下部开口直径最小处等于下部通道最大处。本发明具有在密封胶固化过程结合良好,提高绝缘耐压的优点。(A high-reliability electric heating tube sealing structure and method, wherein a leading rod is arranged in an electric heating tube body, magnesium oxide powder is filled between the leading rod and the tube body, an insulating sealing device is arranged at the sealing position of the electric heating tube body and is divided into an upper opening and a middle channel, lower part passageway, lower part opening, it runs through to draw the stick the middle part passageway of sealing device, be equipped with sealed glue between insulating sealing device and the electrothermal tube body, insulating sealing device upper portion external diameter is greater than electrothermal tube body sealing department outer wall diameter, the lower part external diameter is less than electrothermal tube body inner wall diameter, upper portion opening diameter reduces towards sealing device middle part gradually, lower part passageway diameter reduces towards insulating sealing device middle part gradually, the lower part opening is located lower part passageway below, lower part opening diameter reduces towards lower part passageway gradually, lower part opening diameter minimum equals the maximum department of lower part passageway. The invention has the advantages of good combination in the curing process of the sealant and improved insulation and voltage resistance.)

1. A high reliability electrothermal tube seal structure which characterized in that: comprises an electrothermal tube body, a leading rod is arranged in the electrothermal tube body, magnesium oxide powder is filled between the leading rod and the electrothermal tube body, an insulating sealing device is arranged at the sealing position of the electrothermal tube body, the insulating sealing device comprises a sealing body, an upper opening is arranged at the upper end of the sealing body, a lower opening is arranged at the lower end of the sealing body, a through middle channel is arranged between the upper opening and the lower opening, a gap exists between the middle channel and the leading rod, a step part is arranged on the outer side wall of the sealing body, the leading rod penetrates through the middle channel of the insulating sealing device, sealant is arranged between the insulating sealing device and the electrothermal tube body, the electrothermal tube body is connected with the step part of the sealing body, the diameter of the upper opening of the insulating sealing device is gradually reduced towards the middle channel of the insulating sealing device, and the, the position with the smallest diameter of the lower opening is connected with the position with the largest diameter of the middle channel.

2. The high reliability electric heating tube sealing structure according to claim 1, wherein: the step part of the sealing body comprises a first step part and a second step part, the first step part is connected with the inner side wall of the tubular body of the electric heating tube, and the second step part is connected with the top surface of the tubular body of the electric heating tube.

3. The high reliability electric heating tube sealing structure according to claim 1, wherein: the middle channel sequentially comprises a first middle channel and a lower channel from the upper end to the lower end of the insulating sealing device, the upper end of the first middle channel is communicated with the lower end of the upper opening, the lower end of the first middle channel is communicated with the upper end of the lower channel, and the lower end of the lower channel is communicated with the upper end of the lower opening.

4. A high reliability electric heating tube sealing structure according to claim 3, wherein: the depth of the upper opening of the insulating and sealing device is smaller than that of the lower channel.

5. A high reliability electric heating tube sealing structure according to claim 3, wherein: the diameter of the lower channel is gradually increased from the middle part of the insulating and sealing device to the direction of the lower opening channel.

6. The high reliability electric heating tube sealing structure according to claim 1, wherein: the middle channel is of a cylindrical structure.

7. The method for sealing a high reliability electric heating tube according to claims 1-6, wherein: the method comprises the following steps:

1) filling magnesium oxide powder into the tubular body of the electric heating tube;

2) d mm of magnesia powder is dug at the end part of the electric heating tube;

3) injecting the sealant into the electric heating tube body in advance, and enabling the injected sealant to be d/8mm away from the tube opening of the electric heating tube body;

4) and pressing the insulating sealing device into the sealant, wherein the sealant flows out from the gap between the middle channel and the guide rod to the opening direction of the upper end to fill the gap between the sealing body and the guide rod.

8. The method of claim 7, wherein the sealing step of the electrical heating tube comprises: also comprising after step 4): and 5) if the upper end opening is not filled with the sealant, filling the upper end opening with the sealant.

9. The method of claim 1, wherein the sealing step comprises the steps of: d is 5-13 mm.

Technical Field

The invention relates to the technical field of electric heating, in particular to a high-reliability electric heating tube sealing structure and a method.

Background

When the traditional electric heater is used, the damage or the non-use of the electric heater caused by the reduction of the insulation resistance of the electric heating tube can happen, and once the damage or the non-use happens, serious safety quality problems can be caused. An important requirement of the electric heating tube is that moisture cannot be contained in the electric heating tube. The general treatment method is to place the electric heating tube in the baking oven and heat the electric heating tube at 180-280 deg.C for several hours to 10 hours to fully remove the water absorbed by the magnesium oxide powder in the electric heating tube. The orifice is then sealed with RTV silicone or epoxy (hereinafter collectively referred to as a sealant).

As shown in fig. 1, in order to increase the creepage distance, a sealing cap 3 'is usually pressed into the orifice of the electrical heating tube 1', a guiding rod 5 'is arranged at the orifice of the electrical heating tube 1', the guiding rod 5 'passes through a middle channel of the sealing cap 3', a step part 6 'is arranged on the outer side wall of the sealing cap 3', a gap exists between the step part 6 'and the inner wall of the orifice of the electrical heating tube 1', the pressed sealing cap 3 'is required to be fully contacted with a pre-injected sealant 4' and bonded into a whole, no gap, pinhole or the like exists between the sealing cap and the pre-injected sealant, otherwise, the insulation resistance.

In the actual production, if the amount of the added sealant 4 ' is not enough in the packaging process, a gap is easily generated between the sealing cap 3 ' and the sealant 4 '; if the glue amount is right, but the bottom of the sealing cap 3 'is flat, the sealing cap 3' is easy to generate the condition of air closing in the pressing process, and a small part of air is enclosed between the sealing cap 3 'and the sealing glue 4'; if the added sealant 4 ' is excessive, the sealant 4 ' can overflow from the orifice of the electrothermal tube 1 ', so that the outer wall of the tube is polluted; even if the above factors are not present, gaps and pinholes may be generated at the interface of the sealant 4 ' and the sealing cap 3 ' due to shrinkage (typically shrinkage between 2-5%) during curing of the sealant 4 '. The conditions can cause the situation of unqualified insulation and voltage resistance, and greatly influence the service life and the quality of the electric heater.

Disclosure of Invention

In order to solve the problems in the prior art, the invention provides the electric heating tube sealing structure and the method which have the advantages of reasonable structure, good curing and bonding property of sealing glue, no gap or bubble and good insulating and sealing properties.

In order to achieve the above objects, the present invention provides a high reliability sealing structure for an electric heating tube, including a tube body of the electric heating tube, a guiding rod is arranged in the tube body of the electric heating tube, magnesium oxide powder is filled between the guiding rod and the tube body of the electric heating tube, an insulating sealing device is arranged at a sealing position of the tube body of the electric heating tube, the insulating sealing device includes a sealing body, an upper opening is arranged at an upper end of the sealing body, a lower opening is arranged at a lower end of the sealing body, a through middle channel is arranged between the upper opening and the lower opening, a step portion is arranged on an outer side wall of the sealing body, the guiding rod penetrates through the middle channel of the insulating sealing device, a gap is arranged between the middle channel and the guiding rod, a sealant is arranged between the insulating sealing device and the tube body of the electric heating tube, the tube body, the diameter of the lower opening is reduced towards the direction of the middle channel, the minimum diameter of the lower opening is connected with the maximum diameter of the middle channel,

the arrangement is that the diameter of the upper opening of the insulating sealing device is gradually reduced towards the direction of the middle channel of the insulating sealing device, so that the upper opening presents a funnel shape, when the sealant is cured and contracted, the sealant at the position is contracted downwards, no gap is generated between the sealing body and the contact surface of the sealant, and the diameter of the lower opening is reduced towards the direction of the middle channel, so that the lower opening presents a horn shape, in addition, a middle channel is arranged between the lower opening and the upper opening, and the opening of the middle channel is communicated with the upper opening and the lower opening, so that the sealant forms a tower-shaped structure, the horizontal contact surface between the sealant and the sealing body is eliminated, the air-tight condition is eliminated, thereby greatly improving the reliability of insulation and pressure resistance, meanwhile, a gap exists between the middle channel and the guide rod, so that the sealant smoothly rises to provide a, the bubble condition, sealed glue bonds well at the curing process, can not produce clearance, bubble, in addition because there are middle passageway, lower part opening and upper portion opening on the sealed body to too much sealed glue can upwards spill over from the middle passageway, prevents that too much sealed glue from spilling over from the inside of insulating sealing device and electrothermal tube body and causing the pollution of electrothermal tube pipe outer wall, electrothermal tube insulating sealing performance is good.

Furthermore, the step part of the sealing body comprises a first step part and a second step part, the first step part is connected with the inner side wall of the tubular body of the electric heating tube, and the second step part is connected with the top surface of the tubular body of the electric heating tube.

Further, the middle channel sequentially comprises a first middle channel and a lower channel from the upper end to the lower end of the insulating sealing device, the upper end of the first middle channel is communicated with the lower end of the upper opening, the lower end of the first middle channel is communicated with the upper end of the lower channel, the lower end of the lower channel is communicated with the upper end of the lower opening, the middle channel is divided into two parts, the sealant entering the lower channel is buffered through the middle channel, and the excessive sealant is prevented from entering the sealing body.

Furthermore, the depth of the upper opening of the insulating and sealing device is smaller than that of the lower channel, and due to the fact that the depth of the lower channel is increased, more sealant enters the lower channel and the middle channel, a small amount of sealant enters the upper opening, and the excessive sealant is prevented from entering the upper opening.

Further, the diameter of the lower channel is gradually increased from the middle part of the insulating and sealing device to the lower opening channel, and the lower channel is strong in pressure due to the fact that the opening area of the lower end face of the lower channel is large, and sealant can conveniently enter the middle channel from the lower opening.

Furthermore, the middle channel is of a cylindrical structure, and the middle channel is arranged above the insulating sealing device, so that the sealing glue is well bonded with the insulating sealing device when passing through the middle channel, and the insulating sealing device is tightly combined with the pipe body.

The invention also provides a sealing method of the high-reliability electrothermal tube, which comprises the following steps:

1) filling magnesium oxide powder into the tubular body of the electric heating tube;

2) d mm of magnesia powder is dug at the end part of the electric heating tube;

3) injecting the sealant into the electric heating tube body in advance, and enabling the injected sealant to be d/8mm away from the tube opening of the electric heating tube body;

4) the insulating sealing port device is pressed into the sealant, and the sealant flows out from the gap between the middle channel and the guide rod to the opening direction of the upper end to fill the gap between the sealing body and the guide rod.

In the method, the sealant is firstly injected into the tubular body of the electric heating tube, the injected sealant is away from the tube opening by a certain distance, then the insulating sealing port device is pressed into the sealant, so that the sealant flows out from a gap between the middle channel and the guide rod and fills the gap between the sealing body and the guide rod, the sealant smoothly rises to provide a channel, the gap and the bubble are eliminated, the sealant is well bonded in the curing process, and the gap and the bubble are not generated, in addition, a middle channel is arranged between the lower opening and the upper opening, the opening of the middle channel is communicated with the upper opening and the lower opening, so that the sealant forms a tower-shaped structure, a horizontal contact surface between the sealant and the sealing body is eliminated, and a gas-tight condition is eliminated, thereby greatly improving the reliability of insulation and pressure resistance

Further, the above method further comprises: and 5) if the upper end opening is not filled with the sealant, filling the upper end opening with the sealant, and filling the upper end opening in a post-repairing manner, so that the filling reliability of the upper end opening is ensured.

Furthermore, d is 5-13 mm, and the device is convenient to operate.

Drawings

Fig. 1 is a schematic view of a sealing structure of an electrothermal tube in the prior art.

Fig. 2 is a schematic structural diagram of an electrothermal tube sealing structure according to an embodiment of the present invention.

Fig. 3 is a schematic structural diagram of a first implementation of the insulation sealing device according to the embodiment of the present invention.

Fig. 4 is a schematic structural diagram of a second implementation of the insulation sealing device according to the embodiment of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.