阅读说明：本技术 同位素温差电池气路接口一次密封及二次密封保护的方法 (Method for protecting gas circuit interface of isotope temperature difference battery through primary sealing and secondary sealing ) 是由 侯旭峰 任保国 陈媛媛 阎勇 刘锐 于 2020-04-22 设计创作，主要内容包括：本发明涉及一种同位素温差电池气路接口一次密封及二次密封保护的方法,包括：制造气氛处置接口和保护帽；将气氛处置接口与电池壳端盖螺接定位并进行密封连接；利用超声波高频振荡原理结合特选薄壁铝合金材料,采用超声波封口机对气氛处置接口进行密封焊接,完成气路接口的一次密封；二次密封保护帽,使暴露在电池壳端盖外的气氛处置接口管体和焊口全部伸入保护帽内腔中,采用氩弧焊方式在保护帽台阶坡口环缝位置焊接密封保护帽,完成二次密封保护。本发明有效地提高了同位素温差电池的接口密封成品率和密封性、增强了薄壁接口安全性、缩短了接口密封操作时间,有效保障了同位素温差电池安全性和可靠性、在轨服役寿命、以及操作人员辐射安全性。(The invention relates to a method for protecting a primary seal and a secondary seal of an isotope temperature difference battery gas path interface, which comprises the following steps: manufacturing an atmosphere disposal interface and a protective cap; the atmosphere treatment interface is in threaded connection with the end cover of the battery shell for positioning and sealing connection; the ultrasonic high-frequency oscillation principle is combined with the specially-selected thin-wall aluminum alloy material, and an atmosphere treatment interface is hermetically welded by an ultrasonic sealing machine to finish primary sealing of the gas path interface; and (4) a secondary sealing protective cap, wherein the atmosphere treatment interface pipe body and the welding port exposed outside the end cover of the battery case are enabled to completely extend into the inner cavity of the protective cap, and the sealing protective cap is welded at the position of the circular seam of the step groove of the protective cap in an argon arc welding mode to complete secondary sealing protection. The invention effectively improves the interface sealing yield and the sealing performance of the isotope thermoelectric cell, enhances the safety of the thin-wall interface, shortens the interface sealing operation time, and effectively ensures the safety and the reliability of the isotope thermoelectric cell, the service life of the isotope thermoelectric cell in orbit and the radiation safety of operators.)

1. A method for protecting the primary sealing and the secondary sealing of an air path interface of an isotope temperature difference battery is characterized in that: the method comprises the following steps:

s1 manufacturing atmosphere disposal interface and protective cap

Fabrication of atmosphere treatment interface: selecting a metal pipe fitting to turn and drill to form a thin-walled pipe with the upper end having the wall thickness of 0.8-1.2 mm and the upper end having the pipe length of more than or equal to 50mm, and a short step pipe with threads at the lower end;

manufacturing the protective cap: turning a metal pipe fitting to form a pipe cap with an inner cavity, wherein the upper end of the pipe cap is 2mm thick, the lower end of the pipe cap is provided with an independent groove which is turned and extended outwards and upwards, and the outer end face of the top of the outer edge of the groove is provided with a step groove;

s2, the atmosphere disposal interface and the battery case end cover are positioned through the threaded connection of the lower end of the atmosphere disposal interface, and then the inner side of the battery case end cover is hermetically connected with the annular seam of the atmosphere disposal interface through a fusion welding mode or a compression sealing mode;

s3, after the battery is assembled, integrated and treated in the atmosphere, the atmosphere treatment interface is sealed and welded by an ultrasonic sealing machine, so that a welding opening keeps a uniform fan-shaped grid welding surface, and then a pipe body is cut off at the welding opening grid welding surface by a tail end cutter of the ultrasonic sealing machine, so that the battery atmosphere treatment interface at the gas path connecting passage is separated from an external connecting gas path, and the primary sealing of the gas path interface is completed;

s4, buckling the protective cap on the end cover of the battery shell, and enabling the atmosphere treatment interface tube body and the welding opening exposed outside the end cover of the battery shell to extend into the inner cavity of the protective cap;

s5, adjusting the protective cap to enable the step groove at the bottom of the protective cap to be flush with the end face of the connecting port of the battery case end cover, pressing the protective cap tightly, and welding the sealing protective cap at the position of the step groove circular seam in an argon arc welding mode to finish secondary sealing protection.

2. The method for protecting the primary seal and the secondary seal of the gas path interface of the isotope temperature difference battery according to claim 1, characterized in that: the atmosphere disposal interface is made of aluminum alloy, copper, stainless steel or titanium alloy materials.

3. The method for protecting the primary seal and the secondary seal of the gas path interface of the isotope temperature difference battery according to claim 1, characterized in that: the protective cap is made of aluminum alloy, copper, stainless steel or titanium alloy materials.

4. The method for protecting the primary seal and the secondary seal of the gas path interface of the isotope temperature difference battery according to claim 2 or 3, characterized in that: the aluminum alloy material is 2A16H state aluminum alloy material.

5. The method for protecting the primary seal and the secondary seal of the gas path interface of the isotope temperature difference battery according to claim 1, characterized in that: the fusion welding mode is one of laser welding, argon arc welding and electron beam welding.

Technical Field

The invention belongs to the technical field of isotope temperature difference batteries, and particularly relates to a method for sealing an atmosphere treatment interface of a metal sealed shell of a battery and protecting the sealed interface by secondary sealing.

Background

The isotope thermoelectric cell has the characteristics of compact structure, long service life, high reliability and no dependence on external environment, and is widely applied to deep space exploration tasks. Because the internal working temperature of the product is as high as hundreds of degrees centigrade, the product must be a full-sealing structure in order to ensure the reliability and safety application requirements of the product. Because the product characteristic, need accomplish whole body assembly integrated back at the product, carry out the inside atmosphere of battery and deal with at last, this makes in product design, needs the design to remain independent atmosphere and deals with the interface, handles the back at the completion battery atmosphere, seals the interface again.

In practical work, aiming at the requirements of reducing weight and volume of an isotope temperature difference battery product, a battery shell is usually made of a low-density alloy material, and the height of an interface is reduced as much as possible. Therefore, the sealing of the battery interface must be accomplished at one time. However, since the interface connection tube is usually a hollow thin-walled tube, when the internal atmosphere of the battery is a positive pressure, the interface connection tube is sealed by a direct fusion welding method, and a weld crater is likely to generate pores to cause leakage, so that it is difficult to realize sealed connection under a positive pressure condition by a general fusion welding (for example, TIG argon arc welding) method. In addition, since the isotope thermoelectric cell has radioactivity, if the sealing connection method itself needs a long time or needs a plurality of welding to realize sealing, the irradiation dose of the operator is increased, and unnecessary injuries are caused.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides a method which can quickly and reliably seal an atmosphere treatment interface connecting pipe and finish the sealing of an interface at one time, and takes the structural strength vulnerability of the interface connecting pipe as a thin-wall structure into consideration, thereby increasing a quick secondary sealing protective cap, forming the secondary enhancement effect of the sealing reliability and avoiding the accidental damage to the thin-wall structure of the sealing interface.

The invention is realized in this way, a method for protecting the gas circuit interface of an isotope temperature difference battery by primary sealing and secondary sealing, which comprises the following steps:

s1 manufacturing atmosphere disposal interface and protective cap

Fabrication of atmosphere treatment interface: selecting a metal pipe fitting to turn and drill to form a thin-walled pipe with the upper end having the wall thickness of 0.8-1.2 mm and the upper end having the pipe length of more than or equal to 50mm, and a short step pipe with threads at the lower end;

manufacturing the protective cap: turning a metal pipe fitting to form a pipe cap with an inner cavity, wherein the upper end of the pipe cap is 2mm thick, the lower end of the pipe cap is provided with an independent groove which is turned and extended outwards and upwards, and the outer end face of the top of the outer edge of the groove is provided with a step groove;

s2, the atmosphere disposal interface and the battery case end cover are positioned through the threaded connection of the lower end of the atmosphere disposal interface, and then the inner side of the battery case end cover is hermetically connected with the annular seam of the atmosphere disposal interface through a fusion welding mode or a compression sealing mode;

s3, after the battery is assembled, integrated and treated in the atmosphere, the atmosphere treatment interface is sealed and welded by an ultrasonic sealing machine, so that a welding opening keeps a uniform fan-shaped grid welding surface, and then a pipe body is cut off at the welding opening grid welding surface by a tail end cutter of the ultrasonic sealing machine, so that the battery atmosphere treatment interface at the gas path connecting passage is separated from an external connecting gas path, and the primary sealing of the gas path interface is completed;

s4, buckling the protective cap on the end cover of the battery shell, and enabling the atmosphere treatment interface tube body and the welding opening exposed outside the end cover of the battery shell to extend into the inner cavity of the protective cap;

s5, adjusting the protective cap to enable the step groove at the bottom of the protective cap to be flush with the end face of the connecting port of the battery case end cover, pressing the protective cap tightly, and welding the sealing protective cap at the position of the step groove circular seam in an argon arc welding mode to finish secondary sealing protection.

In the above technical solution, preferably, the atmosphere disposal interface is made of an aluminum alloy, copper, stainless steel or a titanium alloy material.

In the above technical solution, preferably, the protective cap is made of an aluminum alloy, copper, stainless steel or titanium alloy material.

In the above technical solution, it is further preferable that the aluminum alloy material is a 2a 16H-state aluminum alloy material.

In the above technical solution, preferably, the fusion welding mode is one of laser welding, argon arc welding and electron beam welding.

The invention has the advantages and positive effects that:

1. the invention uses the ultrasonic sealing method, seals the air passage by the rapid extrusion deformation of the tube body, and simultaneously leads the aluminum alloy material connecting surface at the extrusion deformation position of the tube body to be rapidly welded and connected by ultrasonic high-frequency vibration, and then leads the battery atmosphere treatment interface at the air passage connecting passage to be separated from the external connecting air passage by the cutting knife at the tail end of the ultrasonic sealing machine, thereby realizing the rapid and one-time sealing of the isotope temperature difference battery atmosphere treatment interface under positive pressure atmosphere.

2. The invention adopts the aluminum alloy material with 2A16H state with better phase fusibility with the light shell material of the thermoelectric cell as an atmosphere disposal interface, the aluminum alloy material can be connected with the material with similar properties by metal fusion welding modes such as electron beam welding, laser welding, argon arc welding and the like, and can also be connected with the dissimilar material by compression sealing and the like; importantly, the aluminum alloy in the 2A16H state has certain mechanical structure strength and good ductility, and is suitable for primary sealing connection by an ultrasonic sealing machine.

3. According to the invention, by selecting the aluminum alloy material with stronger toughness, the sealing connection of the isotope temperature difference battery can be rapidly completed under the atmospheric environment and without the requirement of large heat release, the battery failure caused by the leakage of a fusion welding opening due to the positive pressure atmosphere in the battery when a metal fusion welding mode is adopted can be effectively avoided, the welding time or repair welding times increased due to the connection requirement of a complex welding cooling tool by a large heat welding mode can be effectively avoided, the interface sealing time of the isotope temperature difference battery is shortened by 4/5 due to the ultrasonic welding method of the aluminum alloy thin-wall pipe fitting, and the safety of an operator in a radioactive environment is increased.

4. According to the invention, after the thin-wall interface is subjected to primary ultrasonic sealing, the thick-wall protective cap is adopted to perform secondary sealing protection on the thin-wall interface sealing tube, and as the protective cap is of a thick-wall structure and is connected by a circular seam, an independent cooling protection tool is not required, so that the sealing of the circular seam interface can be conveniently and rapidly completed. Because the volume of the inner cavity of the protective cap is small, the internal air pressure is quickly discharged in the process of high-heat welding, continuous pressure difference cannot be formed, the effectiveness of secondary sealing of the protective cap is ensured, and the sealing reliability is high; meanwhile, the thick-wall protective cap naturally forms physical isolation and protection for the thin-wall interface.

5. The invention utilizes the ultrasonic high-frequency oscillation principle to combine with specially-selected thin-wall aluminum alloy materials, effectively improves the interface sealing yield and the sealing performance of the isotope thermoelectric battery, enhances the safety of the thin-wall interface and shortens the interface sealing operation time; the protective cap structure with the secondary seal is designed, so that the air seal reliability is enhanced, the damage risk to an internal welding opening is avoided, and the safety and reliability of the isotope thermoelectric battery, the service life of an on-orbit and the radiation safety of an operator are effectively guaranteed.

Drawings

FIG. 1 is a schematic diagram of the structure of the atmosphere handling interface of the present invention;

FIG. 2 is a schematic structural view of the protective cap of the present invention;

fig. 3 is a schematic structural view of the battery air passage interface seal of the present invention.

In the figure: 1. an atmosphere disposal interface; 11. a thin-walled tube; 12. a step short pipe; 13. a thread; 2. a protective cap; 21. a trench; 22. an outer edge; 23. step beveling; 3. a battery case end cap; 4. a loop seam; 5. and (5) performing circular seam on the step groove.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.