CN115555712A

CN115555712A - Sealing device and method for metal double-layer vacuum heat-insulation container

Info

Publication number: CN115555712A
Application number: CN202211338716.3A
Authority: CN
Inventors: 刘正林; 唐新新; 王泽龙; 冯兆龙
Original assignee: Chengdu Advanced Metal Materials Industry Technology Research Institute Co Ltd
Current assignee: Chengdu Advanced Metal Materials Industry Technology Research Institute Co Ltd
Priority date: 2022-10-28
Filing date: 2022-10-28
Publication date: 2023-01-03

Abstract

The invention provides a sealing device and a method for a metal double-layer vacuum heat-insulation container, wherein the device comprises an equipment base, a vacuum cover, a vacuum system, a welding system and a welding gun motion system, wherein the equipment base is provided with a fixed structure, the double-layer vacuum container is inverted, and the fixed structure is connected with an opening of the double-layer vacuum container; a circular hole is formed in the outer shell at the bottom of the double-layer vacuum container, and a wafer is placed in the circular hole; the vacuum cover covers the area to be welded on the outer shell at the bottom of the double-layer vacuum container, and the circular hole and the wafer are arranged in the vacuum cover; the vacuum system is connected with the vacuum cover and is used for vacuumizing the inside of the vacuum cover and the gap between the circular hole and the wafer; the welding system is arranged outside the vacuum cover and is used for carrying out vacuum welding on the welding seams between the circular sheets and the circular holes; and the welding gun motion system is connected with the welding system and used for supporting and fixing the welding system and realizing the motion of the welding system. The invention adopts vacuum welding, and has the advantages of compact welding line, no air hole, good sealing effect, durability, stability, high production efficiency and the like.

Description

Sealing device and method for metal double-layer vacuum heat-insulation container

Technical Field

The invention relates to the technical field of manufacturing of vacuum heat-insulating containers, in particular to a sealing device and a sealing method of a metal double-layer vacuum heat-insulating container.

Background

The metal double-layer vacuum heat-insulating container is a container which is made of metal, consists of an inner layer and an outer layer, is vacuum between the inner layer and the outer layer and has the heat-insulating function. There are three heat transfer pathways: heat conduction, convection, radiation. The provision of the inner and outer layer structures and the evacuation between the layers can cut off heat conduction and convection, and if the metal surface is bright and the radiation is reflected, the heat transfer effect will be weak and the object in the inner container will be in a state close to thermal insulation. The vacuum heat-preserving cup for containing hot water is the container, but the metal double-layer vacuum heat-preserving container is not only a heat-preserving cup (and a braising cup), but also comprises a vacuum heat-preserving barrel for the food processing industry, a heat-preserving pot with a built-in electric heating tube, and various industrial heat-preserving containers for storing high-temperature or low-temperature objects in the chemical industry, the medicine industry and the food industry.

To obtain good thermal insulation properties, it is necessary to ensure that the vacuum between the inner and outer layers of the container is good. There are several ways to obtain the vacuum state between the inner and outer layers: (1) Arranging a small hole at the bottom of the outer layer, welding a thin tube, assembling and welding the inner layer and the outer layer in a non-vacuum environment, vacuumizing the space between the inner layer and the outer layer through the thin tube, and sealing the thin tube through a welding method; (2) And (3) arranging small holes at the bottom of the outer layer, firstly, completing assembly welding of the inner layer and the outer layer in a non-vacuum environment, then putting the bottom of the container upwards into a vacuum furnace, placing hot melt adhesive near the small holes, vacuumizing, heating to the melting temperature of the adhesive to enable the adhesive to flow and fill the small holes, and sealing the space between the inner layer and the outer layer after cooling. This method is called "tailless seal" because it does not involve the above-mentioned tubules; (3) Assembling the inner layer and the outer layer, coating brazing materials, carrying out vacuum brazing in a vacuum furnace, cooling and solidifying a welding line, isolating the interlayer space from the outside, and keeping the vacuum state of the interlayer space. In the three ways, a section of tubule is remained at the bottom of the container by a tubule air-extracting sealing method, a base support needs to be additionally arranged at the bottom of the container so as to flatten the bottom of the container for standing, and the remained tubule is shielded so as to be more beautiful; the hot melt adhesive sealing method is the most common method for small heat-insulating containers, and usually tens to hundreds of containers are sealed in a vacuum furnace at the same time, so that the heating temperature is lower (about 200 ℃), the production efficiency is higher than that of a thin tube air-exhaust sealing method, but air leakage often occurs at the sealed position gradually, and a bottom support needs to be additionally arranged; the vacuum brazing method has good sealing effect, attractive weld formation, high brazing temperature, low production efficiency and high production cost. Generally, the prior methods have the problem of insufficient production efficiency.

Therefore, the invention provides a novel sealing method and a device for a metal double-layer vacuum heat-insulating container, which can ensure the beauty of the sealing position of the container and ensure higher production efficiency of the method while obtaining good sealing performance.

Disclosure of Invention

According to the technical problem that the production efficiency is not high enough in all the existing methods, the sealing device and the sealing method for the metal double-layer vacuum heat-insulation container are provided. The invention mainly removes the air in the interlayer through the gap between the pre-opened round hole and the wafer by a vacuum device to ensure that the interlayer is in a vacuum state. And then, welding the wafer and the round hole through vacuum laser welding, and sealing under the condition of keeping the interlayer space in a vacuum state. Thus, after the welding is completed, the interlayer is maintained in a permanently sealed vacuum.

The technical means adopted by the invention are as follows:

a sealing device of a metal double-layer vacuum insulation container comprises: the welding device comprises an equipment base, a vacuum cover, a vacuum system, a welding system and a welding gun motion system, wherein a fixed structure is arranged on the equipment base, a double-layer vacuum container is inverted, the bottom of the double-layer vacuum container is positioned above an opening, and the fixed structure is connected with the opening of the double-layer vacuum container and used for positioning and fixing the double-layer vacuum container; a circular hole is formed in the outer shell at the bottom of the double-layer vacuum container, and a wafer is placed in the circular hole; the vacuum cover covers a region to be welded on an outer shell at the bottom of the double-layer vacuum container, the circular holes and the circular sheets are arranged in the vacuum cover, and the vacuum cover is used for providing a vacuum sealing environment; the vacuum system is connected with the vacuum cover and is used for vacuumizing the inside of the vacuum cover and gaps between the circular holes and the wafer; the welding system is arranged outside the vacuum cover and is used for carrying out vacuum welding on the welding seam between the wafer and the round hole; and the welding gun motion system is connected with the welding system and is used for supporting and fixing the welding system and realizing the motion of the welding system.

Furthermore, the fixing structure is an annular groove formed in the upper surface of the equipment base, the opening of the double-layer vacuum container is inserted into the annular groove, and the size of the annular groove is consistent with that of the opening of the double-layer vacuum container.

Furthermore, a sealing ring is arranged between the vacuum cover and an outer shell at the bottom of the double-layer vacuum container to realize sealing; and an air exhaust port is arranged on the side part of the vacuum cover and is connected with an external air exhaust pipe, and the vacuum system is connected with the vacuum cover through the air exhaust pipe and the air exhaust port.

Further, the vacuum cover is a cylindrical metal vacuum cover, an opening is formed in the upper portion of the vacuum cover, which is far away from the double-layer vacuum container, and quartz glass is installed at the position of the opening; the quartz glass and the vacuum cover are fixedly connected through a flange and a bolt, and a sealing ring is arranged at the joint to realize sealing.

Furthermore, the vacuum system comprises a vacuum pump set, a pipeline, a valve and a vacuum degree detection system, wherein the vacuum pump set is connected with the air pumping port through an air pumping pipe, the valve is arranged on the air pumping pipe, and the vacuum degree detection system is connected with the inside of the vacuum cover and is used for measuring the vacuum degree in the vacuum cover;

the vacuum pump set is a secondary vacuum pump set, and the secondary vacuum pump set consists of a mechanical vacuum pump and a diffusion pump or consists of a mechanical vacuum pump and a molecular pump; all the vacuum pumps are connected through pipelines;

the vacuum detection system comprises a vacuum gauge and a vacuum gauge pipe which are connected, wherein an interface of the vacuum gauge pipe is connected with the extraction opening and is used for measuring the vacuum degree in the vacuum cover and transmitting the measured vacuum degree value to the vacuum gauge for displaying;

the valve comprises an air suction valve and an air release valve; when air is extracted, the air extraction valve is opened and the air release valve is closed; when the air release valve is opened, air release of the vacuum cover is realized.

Further, the welding system comprises a laser, an optical fiber, a laser welding gun and a control system, wherein the control system is connected with the laser and is used for realizing the operation of the laser; the laser is used for generating laser beams and is connected with a laser welding gun through an optical fiber; the laser welding gun is used for irradiating laser beams to the quartz glass, enabling the laser beams to penetrate through the quartz glass and aligning to a welding seam; the laser is an optical fiber type or disc type laser.

Further, the welding gun motion system adopts a robot or a truss type motion mechanism to clamp the laser welding gun, so that the laser welding gun is vertically placed.

Further, the welding gun motion system drives the laser welding gun to do circular motion along a preset track during welding.

Furthermore, the diameter of the round hole is 5-30mm, and the tolerance is 0-0.02mm; the tolerance of the wafer is-0.02-0 mm; the diameter and the material of the circular sheet are the same as those of the circular hole, and the thickness of the circular sheet is smaller than or equal to that of the outer metal shell at the bottom of the double-layer vacuum container.

The invention also provides a sealing method of the sealing device of the metal double-layer vacuum heat-insulation container, which comprises the following steps:

step one, preparation before welding: adopting a laser cutting and drilling method to open a round hole on the bottom outer shell of the double-layer vacuum container, wherein the diameter of the round hole is 5-30mm, and the tolerance is 0-0.02mm; preparing a wafer with the same diameter, the same material and the thickness less than or equal to the thickness of the outer metal shell of the container by adopting laser, plasma cutting or a punch press; when the raw material of the wafer is thicker, the surface of the wafer can be machined by a lathe, and the tolerance of the wafer is-0.02-0 mm; removing organic dirt on the surfaces of the round pieces and the round holes by adopting absolute ethyl alcohol or acetone;

step two, solidifying by pointing: placing the wafer in the circular hole, and fixing the wafer and the circular hole by adopting an argon arc welding or laser welding method; the argon arc welding current is 70-150A, and the laser welding power is 600-2000W;

step three, vacuumizing: inverting the double-layer vacuum container, and placing the bottom of the double-layer vacuum container upwards; covering the area to be welded at the bottom of the double-layer vacuum container with a vacuum cover, and tightly attaching the area to the bottom; opening a vacuum system and an air extraction valve, and starting to vacuumize a vacuum cover until the vacuum degree is less than or equal to 0.0067Pa;

step four, welding: setting laser welding parameters, the movement speed and the movement track of a welding gun movement system according to the thickness and the material properties of the outer layer metal or the wafer of the container, starting welding on the principle of penetration or close penetration without damaging the inner layer metal of the vacuum container; setting laser welding parameters and welding gun movement speed: the laser power is 600-5000W, the movement speed is 10-100mm/s, the defocusing amount is minus 3 mm-3 mm, wherein the defocusing amount is 0 when the focal point is on the surface of the material, the defocusing amount is a positive value when the focal point is on the surface of the material, and otherwise, the defocusing amount is a negative value;

step five, breaking vacuum: after welding, closing the air exhaust valve, opening the air exhaust valve, destroying the vacuum state in the vacuum cover, and separating the vacuum cover from the double-layer vacuum container;

step six, post-treatment: grinding and polishing the welding line by adopting a grinding wheel and a cloth wheel to make the welding line smoother; when the outer metal shell of the container is thick and a 'closed arc pit' exists after welding, an argon arc welding filler wire or laser filler wire welding method is adopted to fill the pit and then the weld joint is ground and polished.

Compared with the prior art, the invention has the following advantages:

the sealing device and the method for the metal double-layer vacuum heat-preservation container adopt vacuum welding, and the welding line is compact, has no air holes, and has good sealing effect and durability and stability. The production efficiency is high. Compared with a vacuum brazing method and a hot melt adhesive method, the method does not need heating and saves energy. Compared with the hot melt adhesive method and the method with tail pipes, the method does not need a bottom support with the functions of covering and protecting, saves materials, reduces weight and is more beautiful. Vacuum laser welding can achieve a large penetration depth, and is also suitable for thick-walled cylinders (when the inner and outer layers of the container are thick).

In conclusion, the technical scheme of the invention can solve the problem that the production efficiency is not high enough in the existing methods.

For the above reasons, the present invention can be widely applied to the fields of manufacturing vacuum heat-insulating containers, and the like.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a schematic view of the structure of the apparatus of the present invention.

FIG. 2 is a schematic view of the welding and sealing position of the double-layered vacuum insulation container of the present invention.

In the figure: 1. an equipment base; 2. a vacuum hood; 3. an air exhaust port; 4. a seal ring; 5. a workpiece; 6. welding; 7. a laser beam; 8. quartz glass; 9. a laser welding gun; 10. an outer wall of the container; 11. an inner wall of the container; 12. and (4) carrying out wafer forming.

Detailed Description

It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict. The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all the embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses. All other embodiments, which can be obtained by a person skilled in the art without making any creative effort based on the embodiments in the present invention, belong to the protection scope of the present invention.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of exemplary embodiments according to the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

The relative arrangement of the components and steps, the numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise. Meanwhile, it should be understood that the sizes of the respective portions shown in the drawings are not drawn in an actual proportional relationship for the convenience of description. Techniques, methods, and apparatus that are known by one of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate. In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting. Thus, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, further discussion thereof is not required in subsequent figures.

As shown in fig. 1, the invention provides a sealing device and a method for a metal double-layer vacuum heat-insulating container, which is a production and manufacturing method for a vacuum heat-insulating container for a production tool or a vacuum heat-insulating container for daily necessities. The metal double-layer vacuum container is widely applied to the fields of daily necessities, foods, medicines, chemical industry and the like. In the manufacturing process, in order to realize vacuum sealing of the interlayer, methods such as hot melt adhesive vacuum heating sealing, vacuum brazing, tail pipe vacuumizing-tail pipe welding and the like are generally adopted. The invention provides a novel sealing method, and the sealing welding with higher efficiency, better quality and more beautiful appearance is realized. The invention has the advantages of novelty, practicability and certain popularization value. The invention is expected to be popularized in companies, at home and abroad.

The sealing device of the metal double-layer vacuum heat-insulating container comprises:

(1) The equipment base 1 is provided with an annular groove with the size consistent with that of a workpiece 5 (a to-be-welded double-layer vacuum heat-insulation container) on the upper surface of the equipment base, and the annular groove is used for positioning and fixing the double-layer vacuum heat-insulation container. Specifically, the double-layer vacuum container is inverted, the bottom of the double-layer vacuum container is located above the opening (namely, the opening is located below, and the bottom of the double-layer vacuum container is located above), the annular groove is connected with the opening of the double-layer vacuum container in a clamping mode, and the opening of the double-layer vacuum container is inserted into the annular groove. The outer shell at the bottom of the upper double-layer vacuum container is provided with a round hole, and a wafer 12 is placed in the round hole. As shown in fig. 2, the casing of the double-layer vacuum container is composed of an outer container wall 10 and an inner container wall 11, a circular hole is formed at the bottom of the outer container wall, and a welding seam 6 (a ring-shaped welding seam) is formed between the circular hole and the circular sheet. The diameter of the round hole is 5-30mm, and the tolerance is 0-0.02mm; the tolerance of the wafer is-0.02-0 mm; the diameter and the material of the round wafer are the same as those of the round hole, and the thickness of the round wafer is smaller than or equal to that of the bottom outer shell of the double-layer vacuum container.

(2) The vacuum housing 2 and vacuum system comprise a cylindrical metal vacuum housing. The vacuum cover covers the area to be welded on the outer shell at the bottom of the double-layer vacuum container, the vacuum cover and the outer shell at the bottom of the double-layer vacuum container are sealed through a sealing ring, the round hole and the wafer are arranged inside the vacuum cover, and the vacuum cover is used for providing a vacuum sealing environment. The vacuum system is connected with the vacuum cover and is used for vacuumizing the inside of the vacuum cover and the gap between the round hole and the wafer. The upper part of the vacuum cover is provided with a hole, and quartz glass 8 is arranged at the position of the hole. The quartz glass and the metal vacuum cover are fixedly connected through a flange and a bolt, and the joint is sealed by a sealing ring. The side part of the vacuum cover is provided with an air exhaust opening 3 (a vacuum air exhaust opening) which is connected with an air exhaust pipe. The vacuum system is connected with the vacuum cover through an exhaust tube and an exhaust port. The vacuum system mainly comprises a vacuum pump set, a pipeline, a valve and a vacuum degree detection system, wherein the vacuum pump set is connected with an air pumping port through an air pumping pipe, the valve is installed on the air pumping pipe, and the vacuum degree detection system is connected with the inside of the vacuum cover and used for measuring the vacuum degree inside the vacuum cover. The vacuum pump set is a two-stage vacuum pump set consisting of a mechanical vacuum pump and a diffusion pump or a molecular pump. Preferably, a secondary pump group consisting of a mechanical vacuum pump and a molecular pump is selected. The vacuum pumps are connected through pipelines. The vacuum detection system comprises a vacuum gauge and a vacuum gauge, wherein an interface of the vacuum gauge is connected with the extraction opening and is used for measuring the vacuum degree in the vacuum cover and transmitting the measured vacuum degree value to the vacuum gauge for displaying. The air exhaust pipe is provided with an air exhaust valve and an air release valve; when air is exhausted, the air exhaust valve is opened, the air release valve is closed, and when the air release valve is opened, the vacuum cover is exhausted.

(4) And the welding system is arranged outside the vacuum cover and is used for carrying out vacuum welding on the welding seams between the circular sheets and the circular holes. The welding system comprises a laser, an optical fiber, a laser welding gun 9 and a control system thereof. The control system is connected with the laser and is used for realizing the operation of the laser; the laser is used for generating a laser beam 7 and is connected with a laser welding gun through an optical fiber; the laser is an optical fiber type or disc type laser.

(5) And the welding gun motion system is connected with the welding system and used for supporting and fixing the welding system and realizing the motion of the welding system. The welding gun motion system clamps the laser welding gun by adopting a robot or a truss motion mechanism, enables the laser welding gun to be vertically placed, irradiates laser beams to quartz glass, penetrates through the quartz glass, aims at a welding seam, and drives the welding gun to do circular motion along a preset track during welding.

The sealing method of the metal double-layer vacuum heat-insulating container by adopting the device comprises the following steps:

step 1, preparation before welding: and adopting a laser cutting and drilling method to form a round hole at the bottom of the outer layer of the double-layer vacuum container. The diameter of the round hole is 5-30mm, and the tolerance is 0-0.02mm. Preparing a wafer with the same diameter, the same material and the thickness less than or equal to the thickness of the metal on the outer layer of the container by using laser or plasma cutting or a punch press. When the material is thicker, the surface of the material can be machined by a lathe. The tolerance of the wafer is-0.02-0 mm. And removing organic dirt on the surfaces of the round pieces and the round holes by adopting absolute ethyl alcohol or acetone.

Step 2, solidifying by pointing: and placing the circular sheet in the circular hole, and fixing the circular sheet and the circular hole by adopting an argon arc welding or laser welding method. The argon arc welding current is 70-150A. The laser welding power is 600-2000W.

Step 3, vacuumizing: the bottom of the vacuum heat-preservation container is placed upwards. And covering the area to be welded at the bottom of the vacuum container by the vacuum cover, and tightly attaching the area to the bottom. And opening a vacuum system and an air extraction valve, and starting to vacuumize until the vacuum degree is less than or equal to 0.0067Pa.

Step 4, welding: and setting laser welding parameters, the movement speed and the movement track of a welding gun movement mechanism according to the thickness and the material properties of the metal or the wafer on the outer layer of the container, and starting welding. Setting laser welding parameters and welding gun movement speed: the laser power is 600-5000W, the defocusing amount is-3 mm (the defocusing amount is 0 when the focal point is on the surface of the material, the defocusing amount is a positive value when the focal point is on the surface of the material, and otherwise, the defocusing amount is a negative value), and the movement speed is 10-100mm/s. The principle is that the inner layer metal of the vacuum container is not damaged due to the fact that the welding is completely or nearly completely welded.

Step 5, breaking vacuum: after welding, the air exhaust valve is closed, and the air exhaust valve is opened to destroy the vacuum state in the vacuum cover. The vacuum hood and the vacuum vessel are separated.

And 6, post-treatment: the welding seam is polished by a grinding wheel and a cloth wheel, so that the welding seam is smoother. When the outer layer metal of the container is thick and a 'closed arc pit' (a pit is formed at the end point of laser welding) is formed after welding, an argon arc welding filler wire or a laser filler wire welding method is adopted to fill the pit, and then the welding line is ground and polished.

The principle of the invention is as follows: and removing air in the interlayer through a gap between the pre-opened circular hole and the wafer by a vacuum device to enable the interlayer to reach a vacuum state. And then, welding the wafer and the circular hole by vacuum laser welding, and sealing under the condition of keeping the interlayer space in a vacuum state. Thus, after the welding is completed, the interlayer is maintained in a permanently sealed vacuum.

The invention has the advantages that: (1) The vacuum welding has compact welding line, no air hole, good sealing effect and durability and stability; (2) Compared with a vacuum brazing method and a hot melt adhesive method, the production efficiency is high (3), heating is not needed, and compared with the hot melt adhesive method and a tail pipe method, the energy-saving method (4) does not need a bottom support with covering and protecting functions, so that materials are saved, the weight is reduced, and the appearance is more attractive; (5) Vacuum laser welding can achieve a large penetration depth, and is also suitable for thick-walled cylinders (where the inner and outer layers of the container are thick).

Example 1

The device and the method provided by the invention are adopted to seal the SUS 304 stainless steel double-layer vacuum thermos cup.

Firstly, a laser cutting method is adopted to cut a round hole at the bottom of the outer layer of the stainless steel vacuum cup, and then a 10mm drill bit is used for processing the round hole on a drilling machine, so that the stainless steel vacuum cup has higher precision and smoother surface. The diameter of the round hole is 20mm. Cutting and blanking by laser, and preparing a wafer which has the diameter of 10mm, is made of the same material and has the thickness equal to the thickness (0.6 mm) of the metal on the outer layer of the vacuum cup. And removing organic dirt on the surfaces of the round pieces and the round holes by adopting absolute ethyl alcohol. The disc was placed in a round hole. In this case, the gap is about 0 to 0.02mm. And fixing the two by spot welding by adopting a laser welding method. The laser welding power is 600W; and (3) welding three welding points at equal intervals along the circumference, wherein the distance between every two adjacent welding points is one third of the circumference. The vacuum cup is placed with the bottom facing upwards, and the vacuum cover is placed on the vacuum cup. And applying a little pressure to joint the sealing ring of the vacuum cover with the bottom of the vacuum cup. And opening a vacuum system and an air extraction valve, and starting to vacuumize until the vacuum degree is lower than 0.0067Pa. Setting the laser welding parameters and the movement speed of the welding gun movement mechanism as follows: the laser power is 600W, the defocusing amount is 0, and the moving speed of the welding gun is 20mm/s. And setting the motion track of the welding gun to be uniform motion along the circumference through robot teaching. The welding is started. After welding, the air exhaust valve is closed, and the air exhaust valve is opened to destroy the vacuum state in the vacuum cover. The vacuum hood and the vacuum vessel are separated. And (5) inspecting the welding seam, and finding that the welding seam is complete and has no obvious defects. The welding seam is polished and polished by adopting a grinding wheel and a cloth wheel, so that the welding seam is smoother and more attractive.

Example 2

The device and the method provided by the invention are adopted to seal the 6061 aluminum alloy double-layer vacuum heat-insulating barrel.

Firstly, a laser cutting method is adopted to cut a round hole at the bottom of the outer layer of the double-layer heat-insulating barrel. And then a 20mm drill bit is used for processing a round hole on the drilling machine, so that the circular hole has higher precision and a smoother surface. The diameter of the round hole is 20mm. Cutting and blanking by using plasma, and preparing a wafer with the diameter of 20mm, the same material and the thickness equal to the thickness (6 mm) of the metal on the outer layer of the heat preservation barrel. And (4) turning on a lathe to process the workpiece to ensure higher precision and smoother surface. And removing organic dirt on the surfaces of the round pieces and the round holes by adopting absolute ethyl alcohol. The disc was placed in a round hole. In this case, the gap is about 0 to 0.02mm. And fixing the two by adopting an argon arc welding method. Argon arc welding current 150A, manual spot welding. Three welding spots are spot-welded at equal intervals along the circumference, and the distance between every two adjacent welding spots is one third of the circumference. The bottom of the vacuum heat-preserving barrel is placed upwards, and the vacuum cover is placed on the vacuum heat-preserving barrel. And applying a little pressure to ensure that the sealing ring of the vacuum cover is attached to the bottom of the heat-insulating barrel. And opening a vacuum system and an air extraction valve, and starting to vacuumize until the vacuum degree is lower than 0.0067Pa. Setting laser welding parameters and the movement speed of a welding gun movement mechanism as follows: the laser power is 3000W, the defocusing amount is-3 mm, and the movement speed of the welding gun is 50mm/s. And setting the motion track of the welding gun to be uniform motion along the circumference through robot teaching. The welding is started. After welding, the air exhaust valve is closed, and the air exhaust valve is opened to destroy the vacuum state in the vacuum cover. The vacuum hood and the vacuum vessel are separated. And (4) inspecting the welding seam, and finding out a welding seam complete without obvious defects except a closed arc point (a welding end position). And (4) performing wire filling repair welding on the arc-closing point by adopting manual argon arc welding. The welding wire is an aluminum welding wire with the diameter of 1.2mm, and the argon arc welding current is 150A. The welding seam is polished and polished by adopting a grinding wheel and a cloth wheel, so that the welding seam is smoother and more attractive.

Example 3

The TC4 titanium alloy double-layer vacuum heat-preservation barrel is sealed by adopting the device and the method provided by the invention.

Firstly, a laser cutting method is adopted to cut a round hole at the bottom of the outer layer of the double-layer heat-insulating barrel. And then a 20mm drill bit is used for processing a round hole on the drilling machine, so that the circular hole has higher precision and a smoother surface. The diameter of the round hole is 20mm. Cutting and blanking by using laser, and preparing a wafer with the diameter of 20mm, the same material and the thickness equal to the thickness (4 mm) of the outer layer metal of the heat preservation barrel. And (4) turning on a lathe to process the workpiece to ensure higher precision and smoother surface. And removing organic dirt on the surfaces of the round pieces and the round holes by adopting absolute ethyl alcohol. The disc was placed in the round hole. In this case, the gap is about 0 to 0.01mm. And fixing the two by adopting an argon arc welding method. Argon arc welding current 120A, manual spot welding. And (3) welding three welding points at equal intervals along the circumference, wherein the distance between every two adjacent welding points is one third of the circumference. The bottom of the vacuum heat-preserving barrel is placed upwards, and the vacuum cover is placed on the vacuum heat-preserving barrel. Applying a little pressure to make the sealing ring of the vacuum cover fit with the bottom of the vacuum cup. And opening a vacuum system and an air extraction valve, and starting to vacuumize until the vacuum degree is lower than 0.0067Pa. Setting the laser welding parameters and the movement speed of the welding gun movement mechanism as follows: the laser power is 2000W, the defocusing amount is 2mm, and the movement speed of the welding gun is 60mm/s. And setting the motion trail of the welding gun to be uniform motion along the circumference through the teaching of the robot. And starting welding. And after welding is finished, closing the air exhaust valve, opening the air release valve and destroying the vacuum state in the vacuum cover. The vacuum hood and the vacuum vessel are separated. And (5) inspecting the welding seam, and finding out a welding seam which is complete and has no obvious defects except for a closed arc point (a welding end position). And (4) adopting manual argon arc welding to perform wire filling and repair welding on the arc-withdrawing point. The welding wire is a titanium welding wire with the diameter of 2.0mm TA2, and the argon arc welding current is 120A. The welding seam is polished and polished by adopting a grinding wheel and a cloth wheel, so that the welding seam is smoother and more attractive.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. The utility model provides a sealing device of metal bilayer vacuum insulation container which characterized in that includes: the welding device comprises an equipment base (1), a vacuum cover (2), a vacuum system, a welding system and a welding gun motion system, wherein a fixed structure is arranged on the equipment base (1), a double-layer vacuum container is inverted, the bottom of the double-layer vacuum container is positioned above an opening, and the fixed structure is connected with the opening of the double-layer vacuum container and used for positioning and fixing the double-layer vacuum container; a round hole is arranged on the outer shell at the bottom of the double-layer vacuum container, and a wafer (12) is placed in the round hole; the vacuum cover (2) covers a region to be welded on an outer shell at the bottom of the double-layer vacuum container, the round hole and the wafer (12) are arranged inside the vacuum cover (2), and the vacuum cover (2) is used for providing a vacuum sealing environment; the vacuum system is connected with the vacuum cover (2) and is used for vacuumizing the inside of the vacuum cover (2) and gaps between the circular holes and the wafer; the welding system is arranged outside the vacuum cover (2) and is used for carrying out vacuum welding on the welding line (6) between the wafer (12) and the round hole; and the welding gun motion system is connected with the welding system and used for supporting and fixing the welding system and realizing the motion of the welding system.

2. The sealing device of the metal double-layer vacuum heat preservation container according to claim 1, characterized in that the fixing structure is an annular groove formed in the upper surface of the equipment base (1), the opening of the double-layer vacuum container is inserted into the annular groove, and the size of the annular groove is consistent with that of the opening of the double-layer vacuum container.

3. The sealing device of the metal double-layer vacuum heat-preservation container according to claim 1, characterized in that a sealing ring (4) is arranged between the vacuum cover (2) and an outer shell at the bottom of the double-layer vacuum container to realize sealing; an air suction opening (3) is installed on the side portion of the vacuum cover (2), the air suction opening (3) is connected with an external air suction pipe, and the vacuum system is connected with the vacuum cover (2) through the air suction pipe and the air suction opening (3).

4. The sealing device of the metal double-layered vacuum insulation container according to claim 1 or 3, wherein the vacuum cover (2) is a cylindrical metal vacuum cover which is far away from the upper opening of the double-layered vacuum container and is provided with quartz glass (8) at the position of the opening; the quartz glass (8) and the vacuum cover (2) are fixedly connected through a flange and a bolt, and a sealing ring is arranged at the joint to realize sealing.

5. The sealing device of the metal double-layer vacuum heat-preservation container according to claim 3, wherein the vacuum system comprises a vacuum pump set, a pipeline, a valve and a vacuum degree detection system, the vacuum pump set is connected with the air suction port (3) through an air suction pipe, the valve is installed on the air suction pipe, and the vacuum degree detection system is connected with the inside of the vacuum cover (2) and used for measuring the vacuum degree inside the vacuum cover (2);

the vacuum pump group is a secondary vacuum pump group, and the secondary vacuum pump group consists of a mechanical vacuum pump and a diffusion pump or consists of a mechanical vacuum pump and a molecular pump; all the vacuum pumps are connected through pipelines;

the vacuum detection system comprises a vacuum gauge and a vacuum gauge pipe which are connected, wherein an interface of the vacuum gauge pipe is connected with the extraction opening (3) and is used for measuring the vacuum degree in the vacuum cover (2) and transmitting the measured vacuum degree value to the vacuum gauge for displaying;

the valve comprises an air suction valve and a deflation valve; when air is extracted, the air extraction valve is opened and the air release valve is closed; when the air release valve is opened, air release of the vacuum cover (2) is realized.

6. The sealing device of the metal double-layer vacuum heat-insulating container is characterized in that the welding system comprises a laser, an optical fiber, a laser welding gun (9) and a control system, wherein the control system is connected with the laser and is used for realizing the operation of the laser; the laser is used for generating a laser beam (7) and is connected with a laser welding gun (9) through an optical fiber; the laser welding gun (9) is used for irradiating a laser beam (7) to the quartz glass (8) and transmitting the quartz glass (8) to align the welding seam (6); the laser is an optical fiber type or disc type laser.

7. The sealing device of the metal double-layer vacuum heat-preservation container according to claim 6, wherein the welding gun moving system adopts a robot or a truss type moving mechanism to clamp the laser welding gun (9) so that the laser welding gun (9) is vertically placed.

8. The sealing device for the metal double-layer vacuum thermal insulation container according to claim 7, wherein the welding gun moving system drives the laser welding gun (9) to move circularly along a preset track during welding.

9. The sealing device of the metal double-layer vacuum heat-preservation container according to claim 1, wherein the diameter of the circular hole is 5-30mm, and the tolerance is 0-0.02mm; the tolerance of the wafer (12) is-0.02-0 mm; the diameter and the material of the circular sheet (12) are the same as those of the circular hole, and the thickness of the circular sheet (12) is smaller than or equal to that of the shell at the outer layer of the bottom of the double-layer vacuum container.

10. A method for sealing a sealing device of a metal double-layered vacuum insulation container according to any one of claims 1 to 9, comprising the steps of:

step one, preparation before welding: adopting a laser cutting and drilling method to open a round hole on the bottom outer shell of the double-layer vacuum container, wherein the diameter of the round hole is 5-30mm, and the tolerance is 0-0.02mm; preparing a wafer (12) with the same diameter, the same material and the thickness less than or equal to the thickness of the metal shell on the outer layer of the container by adopting laser, plasma cutting or a punch press; when the raw material of the wafer (12) is thicker, the surface of the wafer can be machined by a lathe, and the tolerance of the wafer (12) is-0.02-0 mm; removing organic dirt on the surfaces of the wafer (12) and the round holes by adopting absolute ethyl alcohol or acetone;

step two, solidifying by pointing: placing the wafer (12) in the round hole, and fixing the wafer and the round hole by adopting an argon arc welding or laser welding method; the argon arc welding current is 70-150A, and the laser welding power is 600-2000W;

step three, vacuumizing: inverting the double-layer vacuum container, and placing the bottom of the double-layer vacuum container upwards; covering the area to be welded at the bottom of the double-layer vacuum container with a vacuum cover (2), and tightly attaching the area to the bottom; opening a vacuum system and an air extraction valve, and starting to vacuumize the vacuum cover (2) until the vacuum degree is less than or equal to 0.0067Pa;

step four, welding: setting laser welding parameters, the movement speed and the movement track of a welding gun movement system according to the thickness and the material properties of the outer layer metal or the wafer (12) of the container, starting welding on the principle that the inner layer metal of the vacuum container is not damaged due to penetration or close penetration; setting laser welding parameters and welding gun movement speed: the laser power is 600-5000W, the movement speed is 10-100mm/s, the defocusing amount is minus 3 mm-3 mm, wherein the defocusing amount is 0 when the focal point is on the surface of the material, the defocusing amount is a positive value when the focal point is on the surface of the material, and otherwise, the defocusing amount is a negative value;

step five, breaking vacuum: after welding is finished, closing the air exhaust valve, opening the air exhaust valve, destroying the vacuum state in the vacuum cover (2), and separating the vacuum cover (2) from the double-layer vacuum container;

step six, post-treatment: the welding seam (6) is polished and polished by adopting a grinding wheel and a cloth wheel, so that the welding seam is smoother; when the outer metal shell of the container is thick and a 'closed arc pit' exists after welding, the pit is filled by argon arc welding filler wire or laser filler wire welding, and then the welding seam (6) is ground and polished.