Laser welding sealing structure and welding method for ultrathin metal foil and metal tube shell

Abstract

The invention relates to a laser welding sealing structure of an ultrathin metal foil and a metal tube shell and a welding method, and belongs to the technical field of initiating explosive device output end sealing connection. Comprising a tube shell, a foil and a compression ring, wherein the tube shell is of a cylinder structure which is vertically arranged in the axial direction; a through hole is formed in the axis of the tube shell, and a cylindrical groove is formed in the top of the through hole; the foil is of a circular plate-shaped structure; the foil is concentrically arranged in the groove of the tube shell; the pressing ring is of an annular structure. The pressing ring is placed on the upper surface of the foil; the welding method comprises the steps that S1, the foil is placed in the groove of the tube shell; s2, a pressing ring is placed on the foil, and the foil is pressed; s3, preliminarily welding a joint between the inner wall of the tube shell and the outer edge of the pressing ring; s4, a joint between the inner wall of the tube shell and the outer edge of the pressing ring is completely welded; the problem of ablation during laser welding sealing of the ultrathin metal foil and the tube shell is solved, and laser welding sealing connection of the ultrathin foil at the output end of the initiating explosive device is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of sealed connection of output ends of pyrotechnic devices, and relates to a laser welding sealing structure and a welding method of an ultra-thin metal foil and a metal tube shell. Background Art

[0002] Explosives are subject to complex environmental conditions during transportation, storage, and flight. The sealing of the product is directly related to whether the product can work reliably. Traditional pyrotechnics often use gluing or crimping to seal the aluminum foil with the product. As the extreme environment that pyrotechnics have to withstand becomes more and more severe and the storage period is required to be higher, the existing adhesive sealing structure is difficult to meet the needs of long-term stable use of pyrotechnics.

[0003] It is proposed to use laser welding to achieve a sealed connection at the output end of the pyrotechnic. In order to meet the blasting requirements of the sealed structure, after analysis and calculation, the thickness of the foil used for laser welding of pyrotechnics should be less than 0.1mm. Because the foil is too thin, direct laser welding will cause foil ablation and fail to form a sealed connection. At present, there is no report on the laser welding and sealing of ultra-thin metal foil (less than 0.1mm thick) with the shell.

[0004] In the prior art, after overlapping two foils to be welded, the foils are pressed tightly with heat sinks at both ends of the foils, and then the foils are welded with lasers. The heat of the laser is quickly dissipated to the heat sinks, and the foils are welded without the problem of ablating the foils. The thickness of the foil that can be welded is (0.01-0.15) mm. This method only welds the foils, which does not meet the sealing requirements of the pyrotechnic product after a circle of welding. Summary of the invention

[0005] The technical problem solved by the present invention is: to overcome the shortcomings of the prior art, propose a laser welding sealing structure and a welding method for an ultra-thin metal foil and a metal tube shell, overcome the ablation problem during laser welding sealing of the ultra-thin metal foil and the tube shell, and realize the laser welding sealing connection of the ultra-thin foil 2 at the output end of the pyrotechnic device.

[0006] The solution of the present invention is:

[0007] The laser welding sealing structure of an ultra-thin metal foil and a metal tube shell comprises a tube shell, a foil and a pressure ring; wherein the tube shell is a cylindrical structure placed vertically axially; a through hole is provided at the axis of the tube shell, and a cylindrical groove is opened at the top of the through hole; the foil is a circular plate-shaped structure; the foil is concentrically placed in the groove of the tube shell; the pressure ring is a circular ring-shaped structure; and the pressure ring is placed on the upper surface of the foil.

[0008] In the laser welding sealing structure of the ultra-thin metal foil and the metal tube shell, the tube shell, foil and pressure ring are made of the same material, which is stainless steel, titanium alloy, nickel-based alloy, copper alloy or aluminum alloy.

[0009] In the laser welding sealing structure of the ultra-thin metal foil and the metal shell, the thickness of the pressure ring is set to a, the thickness of the metal foil is set to b, the depth of the groove of the shell is set to c, the diameter of the groove of the shell is set to d, the single-side width of the pressure ring is set to e, and the outer diameter of the pressure ring is set to f; the following size requirements are met:

[0010] a+b=c;

[0011] d=f-0.02.

[0012] In the laser welding sealing structure of the ultra-thin metal foil and the metal tube shell, a is 0.4-0.6 mm; b is 0.01-0.1 mm; d is 8-100 mm; and e is 1-10 mm.

[0013] In the laser welding sealing structure of the ultra-thin metal foil and the metal shell, the single side width of the pressure ring is e.

[0014] The welding method of the laser welding sealing structure of the ultra-thin metal foil and the metal tube shell comprises the following steps:

[0015] S1, placing the foil in the groove of the tube shell;

[0016] S2, placing the pressure ring on the foil and pressing the foil tightly;

[0017] S3, preliminarily welding the joint between the inner wall of the tube shell and the outer edge of the pressure ring;

[0018] S4. Completely weld the joint between the inner wall of the tube shell and the outer edge of the pressure ring.

[0019] In the above welding method, in S2, the pressure ring is pressurized by an external pressurizing tool so that the pressure ring is pressed tightly against the foil.

[0020] In the above welding method, in S3, the tube shell and the pressure ring are welded by spot welding; during the welding process, the foil is kept in a tight state, and the pressure ring and the top end surface of the tube shell are flat.

[0021] In the above welding method, in S4, a circle of seams between the tube shell and the pressure ring is laser welded; the pressure ring is melted through, and the molten metal droplets in the molten pool realize a sealed connection between the pressure ring, the foil, and the tube shell.

[0022] In the above welding method, the process parameters of the laser welding are:

[0023] The power is 500-900W; the welding time is 1-3s; the defocus is 0~-0.5mm; the optical fiber core diameter is 50μm; the shielding gas is argon, and the shielding gas flow rate is 8-15L / min.

[0024] The beneficial effects of the present invention compared with the prior art are:

[0025] (1) The thickness of the weldable metal foil 2 of the present invention is (0.01-0.1) mm, which is thinner than the conventional laser-weldable foil 2. The bursting pressure of the tube shell sealing structure is lower. The foil 2 is welded by the molten pressure ring 3. The laser welding process parameters are easy to adjust and the welding success rate is high.

[0026] (2) The present invention adopts laser welding for sealing, which has good appearance after welding, can withstand more severe environmental and mechanical conditions, has stable sealing performance, and has good long-term storage performance;

[0027] (3) The present invention adjusts the diameter and thickness of the foil 2 for laser welding and sealing, and can obtain the required tube shell 1 components with different blasting pressures, which is convenient for satisfying the pyrotechnics in different usage scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is an exploded schematic diagram of the sealing structure of the present invention;

[0029] Figure 2 This is a schematic diagram of the sealing structure assembly of the present invention;

[0030] Figure 3 It is a schematic diagram of the sealing structure dimensions of the present invention. DETAILED DESCRIPTION

[0031] The present invention will be further described below in conjunction with the embodiments.

[0032] The present invention provides a laser welding sealing structure and a welding method for an ultra-thin metal foil and a metal tube shell, which overcomes the ablation problem during laser welding sealing of the ultra-thin metal foil and the tube shell, and realizes the laser welding sealing connection of the ultra-thin foil at the output end of the pyrotechnic device.

[0033] Laser welding sealing structure of ultra-thin metal foil and metal shell, such as Figure 1 , Figure 2 As shown, it specifically includes a tube shell 1, a foil 2 and a pressure ring 3. Among them, the tube shell 1 is a cylindrical structure placed vertically in the axial direction; a through hole is provided at the axis of the tube shell 1, and a cylindrical groove is opened at the top of the through hole; the foil 2 is a circular plate-shaped structure; the foil 2 is concentrically placed in the groove of the tube shell 1; the pressure ring 3 is a circular ring-shaped structure; and the pressure ring 3 is placed on the upper surface of the foil 2.

[0034] The tube shell 1, the foil 2 and the pressure ring 3 are made of the same material, which is stainless steel, titanium alloy, nickel-based alloy, copper alloy or aluminum alloy.

[0035] The thickness of the pressing ring 3 is set to a, the thickness of the metal foil 2 is set to b, the depth of the groove of the tube shell 1 is set to c, the diameter of the groove of the tube shell 1 is set to d, the single-side width of the pressing ring 3 is set to e, and the outer diameter of the pressing ring 3 is set to f; the following size requirements are met:

[0036] a+b=c;

[0037] d=f-0.02.

[0038] a is 0.4-0.6mm; b is 0.01-0.1mm; d is 8-100mm; e is 1-10mm.

[0039] The single side width of the pressure ring 3 is e.

[0040] The laser welding method for sealing the ultra-thin metal foil and the metal shell comprises the following steps:

[0041] S1 . Place the foil 2 in the groove of the tube shell 1 .

[0042] S2, placing the pressing ring 3 on the foil 2, and pressing the foil 2. Using an external pressurizing tool to press the pressing ring 3, so that the pressing ring 3 is pressed tightly on the foil 2.

[0043] S3, preliminary welding is performed on the joint between the inner wall of the tube shell 1 and the outer edge of the pressure ring 3. The tube shell 1 and the pressure ring 3 are welded by spot welding; during the welding process, the foil 2 is kept pressed tightly, and the pressure ring 3 and the top end surface of the tube shell 1 are flat.

[0044] S4. Completely weld the joint between the inner wall of the tube shell 1 and the outer edge of the pressure ring 3.

[0045] A circle of seams between the tube shell 1 and the pressure ring 3 is laser welded; the pressure ring 3 is melted through, and the molten metal droplets in the molten pool realize a sealed connection between the pressure ring 3, the foil 2, and the tube shell 1.

[0046] The process parameters of laser welding are:

[0047] The power is 500-900W; the welding time is 1-3s; the defocus is 0~-0.5mm; the optical fiber core diameter is 50μm; the shielding gas is argon, and the shielding gas flow rate is 8-15L / min.

[0048] The weldable and sealed metal foil 2 of the present invention has a thickness of 0.01-0.1 mm, which is thinner than the conventional laser-weldable foil 2. The bursting pressure of the tube shell sealing structure is lower. The foil 2 is welded by the molten pressure ring 3. The laser welding process parameters are easy to adjust and the welding success rate is high.

[0049] The present invention adopts laser welding for sealing, has good appearance after welding, can withstand more severe environmental, mechanical and other conditions, has stable sealing performance, and has good long-term storage performance.

[0050] By adjusting the diameter and thickness of the foil 2 for laser welding and sealing, a tube shell 1 assembly with different required bursting pressures can be obtained, which is convenient for satisfying pyrotechnics in different usage scenarios.

[0051] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

Claims

1. The laser welding sealing structure of ultra-thin metal foil and metal shell is characterized by: It comprises a tube shell (1), a foil (2) and a pressure ring (3); The tube shell (1) is a cylindrical structure placed vertically in an axial direction; a through hole is provided at the axis of the tube shell (1), and a cylindrical groove is provided at the top of the through hole; the foil (2) is a circular plate-shaped structure; the foil (2) is concentrically placed in the groove of the tube shell (1); the pressure ring (3) is a circular ring-shaped structure; and the pressure ring (3) is placed on the upper surface of the foil (2).

2. The laser welding sealing structure of the ultra-thin metal foil and the metal tube shell according to claim 1 is characterized in that: The tube shell (1), foil (2) and pressure ring (3) are made of the same material, which is stainless steel, titanium alloy, nickel-based alloy, copper alloy or aluminum alloy.

3. The laser welding sealing structure of the ultra-thin metal foil and the metal tube shell according to claim 1 is characterized in that: The thickness of the pressure ring (3) is set to a, the thickness of the metal foil (2) is set to b, the depth of the groove of the tube shell (1) is set to c, the diameter of the groove of the tube shell (1) is set to d, the single-side width of the pressure ring (3) is set to e, and the outer diameter of the pressure ring (3) is set to f; the following size requirements are met: a+b=c; d=f-0.

02.

4. The laser welding sealing structure of the ultra-thin metal foil and the metal tube shell according to claim 3 is characterized in that: The a is 0.4-0.6mm; b is 0.01-0.1mm; d is 8-100mm; and e is 1-10mm.

5. The laser welding sealing structure of the ultra-thin metal foil and the metal tube shell according to claim 3 is characterized in that: The single side width e of the pressure ring (3) is 6. The welding method of the laser welding sealing structure of the ultra-thin metal foil and the metal tube shell according to claim 1 is characterized in that: The steps include: S1, placing the foil (2) in the groove of the tube shell (1); S2, placing the pressure ring (3) on the foil (2) and pressing the foil (2); S3, preliminarily welding the joint between the inner wall of the tube shell (1) and the outer edge of the pressure ring (3); S4. Completely weld the joint between the inner wall of the tube shell (1) and the outer edge of the pressure ring (3).

7. The welding method according to claim 6, characterized in that: In S2, the pressure ring (3) is pressurized by an external pressurizing tool so that the pressure ring (3) is pressed tightly against the foil (2).

8. The welding method according to claim 6, characterized in that: In the above-mentioned S3, the tube shell (1) and the pressure ring (3) are welded by spot welding; during the welding process, the foil (2) is kept in a tight state, and the top end surfaces of the pressure ring (3) and the tube shell (1) are flat.

9. The welding method according to claim 6, characterized in that: In S4, a circle of seams between the tube shell (1) and the pressure ring (3) are laser welded; the pressure ring (3) is melted through, and molten metal droplets in the molten pool realize a sealed connection between the pressure ring (3), the foil (2), and the tube shell (1).

10. The welding method according to claim 9, characterized in that: The process parameters of the laser welding are: The power is 500-900W; the welding time is 1-3s; the defocus is 0~-0.5mm; the optical fiber core diameter is 50μm; the shielding gas is argon, and the shielding gas flow rate is 8-15L / min.

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