阅读说明：本技术 环缝锁底接头激光焊接方法及系统 (Laser welding method and system for circular seam lock bottom joint ) 是由 胡佩佩 张登明 曾敏 高建新 于 2021-09-14 设计创作，主要内容包括：本发明提供了一种环缝锁底接头激光焊接方法及系统,包括如下步骤：接头设计步骤：在锁底件的两个贴合面的夹角处设计凹槽,两个贴合面分别为第一贴合面和第二贴合面,在其中第一贴合面处设计导气孔,导气孔用于联通凹槽和锁底件外表面；部件制备步骤：加工制备锁底件和被锁底件,并将加工好的锁底件和被锁底件清理干净；装配与点焊步骤：将清理干净后的锁底件和被锁底件配合装夹后,一起装配到旋转变位装置上,并采用激光点焊工艺将第一贴合面断续点固；满焊步骤：采用激光焊接工艺将第一贴合面熔合。本发明通过在锁底件上的两个贴合面的夹角处设计凹槽结构,在结构上实现了激光焊接的穿透状态,解决气孔问题。(The invention provides a laser welding method and a laser welding system for a circular seam lock bottom joint, which comprise the following steps: a joint design step: a groove is designed at the included angle of two binding surfaces of the lock bottom piece, the two binding surfaces are respectively a first binding surface and a second binding surface, and an air guide hole is designed at the first binding surface and is used for communicating the groove and the outer surface of the lock bottom piece; a component preparation step: processing and preparing a bottom locking piece and a bottom locking piece, and cleaning the processed bottom locking piece and the processed bottom locking piece; assembling and spot welding: after the cleaned lock bottom piece and the cleaned lock bottom piece are clamped in a matched mode, the lock bottom piece and the lock bottom piece are assembled on a rotary displacement device together, and the first binding surface is intermittently fixed in a point mode through a laser spot welding process; and (3) full welding: and fusing the first binding surface by adopting a laser welding process. According to the invention, the groove structure is designed at the included angle of the two binding surfaces on the lock bottom piece, the penetration state of laser welding is realized structurally, and the problem of air holes is solved.)

1. A laser welding method for a circular seam lock bottom joint is characterized by comprising the following steps:

a joint design step: a groove is designed at the included angle of two binding surfaces of the lock bottom piece, the two binding surfaces are respectively a first binding surface and a second binding surface, and an air guide hole is designed at the first binding surface and is used for communicating the groove and the outer surface of the lock bottom piece;

a component preparation step: processing and preparing a bottom locking piece and a bottom locking piece, and cleaning the processed bottom locking piece and the processed bottom locking piece;

assembling and spot welding: after the cleaned lock bottom piece and the cleaned lock bottom piece are clamped in a matched mode, the lock bottom piece and the lock bottom piece are assembled on a rotary displacement device together, and the first binding surface is intermittently fixed in a point mode through a laser spot welding process;

and (3) full welding: and fusing the first binding surface by adopting a laser welding process.

2. The laser welding method for a circular seam lock bottom joint according to claim 1, wherein the left boundary of the groove is positioned on the left side of the first abutting surface.

3. The laser welding method for a circular seam lock bottom joint according to claim 1, wherein the gas vent is located on the lock bottom member or the lock bottom member.

4. The laser welding method for a circular seam lock bottom joint according to claim 1, wherein the cross section of the air vent is semicircular or polygonal.

5. The laser welding method for a circular seam lock bottom joint according to claim 4, wherein the cross section of the air vent is semicircular.

6. The laser welding method for the circular seam lock bottom joint according to claim 5, wherein the profile diameter of the air guide hole is 0.05-1 mm.

7. The laser welding method for a circular seam lock bottom joint according to claim 4, wherein the gas holes are uniformly distributed in a radial direction.

8. The laser welding method for the circular seam lock bottom joint according to claim 7, wherein the interval between the air guide holes is 0.1-10 °.

9. The laser welding method for a circular seam lock bottom joint according to claim 1, wherein the pitch between the air-guide holes is 5 °.

10. The utility model provides a circular seam lock bottom connection laser welding system which characterized in that includes following module:

a joint design module: a groove is designed at the included angle of two binding surfaces of the lock bottom piece, the two binding surfaces are respectively a first binding surface and a second binding surface, and an air guide hole is designed at the first binding surface and is used for communicating the groove and the outer surface of the lock bottom piece;

a component preparation module: processing and preparing a bottom locking piece and a bottom locking piece, and cleaning the processed bottom locking piece and the processed bottom locking piece;

assembling and spot welding modules: after the cleaned lock bottom piece and the cleaned lock bottom piece are clamped in a matched mode, the lock bottom piece and the lock bottom piece are assembled on a rotary displacement device together, and the first binding surface is intermittently fixed in a point mode through a laser spot welding process;

and (3) full welding module: and fusing the first binding surface by adopting a laser welding process.

Technical Field

The invention relates to the technical field of laser welding, in particular to a laser welding method and a laser welding system for a circular seam lock bottom joint.

Background

The lock bottom joint has smooth inner wall due to the process characteristic of no penetration welding, and the highest temperature of the inner wall temperature thermal cycle is lower than the melting point of the inner wall material, so the lock bottom joint is particularly suitable for the design of the welding joint of a closed structure with fillers, such as a stainless steel combustion chamber shell of a certain type of side force solid rocket engine, and is designed by adopting the lock bottom joint and formed by welding. In addition, for the circular seam butt joint of large-size thin-wall parts, reliable assembly and positioning can be easily realized by the lock bottom joint, for example, the connection between the cylinder section of a certain titanium alloy annular storage box and the end frame adopts the lock bottom joint design and is formed by welding, but in the welding process, the problem that air holes are easily formed in the non-penetrating state of the laser welding of the lock bottom joint is solved.

Patent document No. CN109454330B discloses a circular seam lock bottom joint and a manufacturing and welding method thereof, the method mainly includes a joint design step, a component preparation step, a welding preparation step, an assembly spot welding step, and a formal welding step, the joint design focuses on the problem that an air hole is easily formed in a non-penetration state of the lock bottom joint laser welding, a groove is designed on the lock bottom piece, and a groove is designed on the lock bottom piece. However, this patent document has an adverse effect on the interior of the product: 1. high-temperature metal steam enters the inner cavity of the product to form a heating effect on the filler in the inner cavity of the product, so that safety risk exists, and particularly when the filler is flammable and explosive substances; 2. after the metal vapor is cooled, particles can be formed, the particles can exist in the grooves and even enter the inner cavity of the product to form surplus substances, the composition of the filler is influenced, and the quality risk exists.

Patent document CN104439686A discloses a friction stir welding method for a lock bottom circular seam of a carrier rocket tank. It comprises the following steps: the method comprises the following steps: transforming a welded part, forming a welding leakage groove on the box bottom forked ring, wherein the welding leakage groove is arranged at the bottommost part of the welding line of the box bottom forked ring, and the second step: and (3) overlapping the welding parts, namely overlapping the welded box bottom forked ring and the short shell together to form a welding seam, and performing the third step: and (4) welding, namely welding along the welding seam by using a friction stir welding mode. However, this patent document still has a drawback that the non-penetration state of the laser welding of the lock bottom joint is liable to form the air hole.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide a laser welding method and a laser welding system for a circular seam lock bottom joint.

The invention provides a laser welding method for a circular seam lock bottom joint, which comprises the following steps:

a joint design step: a groove is designed at the included angle of two binding surfaces of the lock bottom piece, the two binding surfaces are respectively a first binding surface and a second binding surface, and an air guide hole is designed at the first binding surface and is used for communicating the groove and the outer surface of the lock bottom piece;

a component preparation step: processing and preparing a bottom locking piece and a bottom locking piece, and cleaning the processed bottom locking piece and the processed bottom locking piece;

assembling and spot welding: after the cleaned lock bottom piece and the cleaned lock bottom piece are clamped in a matched mode, the lock bottom piece and the lock bottom piece are assembled on a rotary displacement device together, and the first binding surface is intermittently fixed in a point mode through a laser spot welding process;

and (3) full welding: and fusing the first binding surface by adopting a laser welding process.

Preferably, the left boundary of the groove is located on the left side of the first abutting surface.

Preferably, the air vent is located on the locking bottom piece or on the locking bottom piece.

Preferably, the cross section of the air guide hole is circular or polygonal.

Preferably, the cross section of the air guide hole is circular.

Preferably, the profile diameter of the air guide hole is 0.05-1 mm.

Preferably, the air holes are uniformly distributed along the radial direction.

Preferably, the distance between the air guide holes is 0.1-10 degrees.

Preferably, the distance between the air guide holes is 5 degrees.

The invention also provides a laser welding system for the circular seam lock bottom joint, which comprises the following modules:

a joint design module: a groove is designed at the included angle of two binding surfaces of the lock bottom piece, the two binding surfaces are respectively a first binding surface and a second binding surface, and an air guide hole is designed at the first binding surface and is used for communicating the groove and the outer surface of the lock bottom piece;

a component preparation module: processing and preparing a bottom locking piece and a bottom locking piece, and cleaning the processed bottom locking piece and the processed bottom locking piece;

assembling and spot welding modules: after the cleaned lock bottom piece and the cleaned lock bottom piece are clamped in a matched mode, the lock bottom piece and the lock bottom piece are assembled on a rotary displacement device together, and the first binding surface is intermittently fixed in a point mode through a laser spot welding process;

and (3) full welding module: and fusing the first binding surface by adopting a laser welding process.

Compared with the prior art, the invention has the following beneficial effects:

1. according to the invention, the groove structure is designed at the included angle of the two binding surfaces on the lock bottom piece, namely a certain free space is created on the back of the welding seam, and the penetration state of laser welding is structurally realized, so that the bottom of a small hole of the laser welding can be in a free state, and bubbles which need to overflow upwards can not be generated, thus the problem of air holes can be solved;

2. according to the invention, the air guide hole is designed at the binding surface of the lock bottom piece, and the air guide hole is communicated with the closed cavity formed by the groove and the outer wall of the lock bottom piece, so that the internal pressure of the closed cavity is reduced, and the phenomenon that the welding process is influenced by the fact that metal steam escapes from the small laser welding hole due to 'air blocking' is avoided;

3. according to the invention, the air guide hole is designed at the binding surface of the lock bottom piece, and the air guide hole is communicated with the closed cavity formed by the groove and the outer wall of the lock bottom piece, so that high-temperature metal steam is guided to the outside of a product, the phenomenon that a filling material in the inner cavity of the product is heated is avoided, and the safety risk is avoided;

4. according to the invention, the air guide hole is designed at the binding surface of the lock bottom piece and is communicated with the closed cavity formed by the groove and the outer wall of the lock bottom piece, so that the situation that particles formed after metal vapor is cooled exist in the groove and even enter the inner cavity of a product to form surplus objects which can influence the components of a filler and can also generate static electricity or sparks by rubbing with the inner wall of the metal in the service process is avoided, and the quality and further safety risk are avoided.

Drawings

Other features, objects and advantages of the invention will become more apparent upon reading of the detailed description of non-limiting embodiments with reference to the following drawings:

FIG. 1 is a first schematic view of a joint design according to an embodiment of the present invention;

FIG. 2 is a cross-sectional view of a lock base along an abutting surface A according to an embodiment of the present invention;

FIG. 3 is a schematic view of an upright weld attitude in an embodiment of the present invention;

fig. 4 is a second schematic diagram of a joint design in an embodiment of the invention.

Detailed Description

The present invention will be described in detail with reference to specific examples. The following examples will assist those skilled in the art in further understanding the invention, but are not intended to limit the invention in any way. It should be noted that it would be obvious to those skilled in the art that various changes and modifications can be made without departing from the spirit of the invention. All falling within the scope of the present invention.

Example 1:

as shown in fig. 1 to 3, the laser welding method for the circular seam lock bottom joint provided in this embodiment includes the following steps:

a joint design step: a groove is designed at the included angle of two binding surfaces of the lock bottom piece, the two binding surfaces are respectively a first binding surface and a second binding surface, and an air guide hole is designed at the first binding surface and is used for communicating the groove and the outer surface of the lock bottom piece;

a component preparation step: processing and preparing a bottom locking piece and a bottom locking piece, and cleaning the processed bottom locking piece and the processed bottom locking piece;

assembling and spot welding: after the cleaned lock bottom piece and the cleaned lock bottom piece are clamped in a matched mode, the lock bottom piece and the lock bottom piece are assembled on a rotary displacement device together, and the first binding surface is intermittently fixed in a point mode through a laser spot welding process;

and (3) full welding: and fusing the first binding surface by adopting a laser welding process.

The left boundary of the groove is positioned on the left side of the first binding surface. The air guide holes are positioned on the bottom locking piece or the bottom locking piece, the cross sections of the air guide holes are circular or polygonal, the cross sections of the air guide holes are circular, the outline diameter of the air guide holes is 0.05-1 mm, the air guide holes are uniformly distributed along the radial direction, the distance between the air guide holes is 0.1-10 degrees, and the distance between the air guide holes is 5 degrees.

Example 2:

the laser welding system for the circular seam lock bottom joint provided by the embodiment comprises the following modules:

a joint design module: a groove is designed at the included angle of two binding surfaces of the lock bottom piece, the two binding surfaces are respectively a first binding surface and a second binding surface, and an air guide hole is designed at the first binding surface and is used for communicating the groove and the outer surface of the lock bottom piece;

a component preparation module: processing and preparing a bottom locking piece and a bottom locking piece, and cleaning the processed bottom locking piece and the processed bottom locking piece;

assembling and spot welding modules: after the cleaned lock bottom piece and the cleaned lock bottom piece are clamped in a matched mode, the lock bottom piece and the lock bottom piece are assembled on a rotary displacement device together, and the first binding surface is intermittently fixed in a point mode through a laser spot welding process;

and (3) full welding module: and fusing the first binding surface by adopting a laser welding process.

Example 3:

those skilled in the art will understand this embodiment as a more specific description of embodiments 1 and 2.

As shown in fig. 2 to 4, in the laser welding method for the circular seam lock bottom joint provided in this embodiment, the joint design is mainly that, for the problem that the air hole is easily formed in the non-penetrating state of the laser welding of the lock bottom joint, a groove is designed at an included angle between the attaching surface a and the attaching surface B on the lock bottom piece, and an air guide hole is designed at the attaching surface a on the lock bottom piece, and the air guide hole can communicate a closed cavity formed by the groove with the outside, so as to guide high-temperature metal vapor generated by the laser welding to the outside of the lock bottom piece.

The groove is deep into the lock bottom piece, so that the left boundary of the groove is positioned on the left side of the binding surface A, the symmetry of heat capacities of two sides of butt welding can be further improved, and the forming uniformity of a welding seam is improved.

The air guide holes are positioned on the lock bottom piece and are distributed along the radial direction.

The cross section of the air guide hole is semicircular.

The diameter of the air guide hole is 0.5 mm.

The spacing between the gas-guiding holes is 5 deg..

Example 4:

those skilled in the art will understand this embodiment as a more specific description of embodiments 1 and 2.

As shown in fig. 2 to 4, the laser welding method for the circular seam lock bottom joint provided in this embodiment mainly includes the following steps:

(1) joint design: butt joint face thickness is 5 mm's circumferential weld lock base connector, sets up the recess in the contained angle department of the binding face A of lock base spare and binding face B, and the recess is deepened 0.5mm toward the left side, turns right 2mm, down 1 mm. In addition, 72 air guide holes are designed on the binding surface A, an annular cavity formed by the air guide hole communication grooves and the outer surface of the lock bottom piece are uniformly distributed at intervals of 5 degrees, and the cross section of each air guide hole is in a semicircular shape with the diameter of 0.5 mm.

(2) Preparing a part: preparing a bottom locking piece and a bottom locking piece by adopting a machining process, and pickling and drying;

(3) assembling and spot welding: after the bottom locking piece and the bottom locking piece are clamped in a matched mode, the bottom locking piece and the bottom locking piece are assembled on a horizontal rotating displacement device together, and spot welding fixing is carried out vertically downwards at the position A of the binding surface by adopting a laser spot welding process; the main parameters of the laser spot welding process are as follows: the laser power is 1000W, the welding speed is 1m/min, and the defocusing amount is-1 mm.

(4) Full welding: adjusting a laser welding head to be in a vertical welding posture by adopting a laser welding process; the main parameters of the laser welding process are as follows: the laser power is 4000W, the welding speed is 0.8m/min, and the defocusing amount is-1 mm.

The joint design of the invention mainly aims at the problem that the air holes are easily formed in the non-penetration state of the laser welding of the lock bottom joint, the groove is designed on the lock bottom piece, the penetration state of the laser welding is realized on the structure of the groove, and the air hole problem can be solved. In order to further solve the problems that after the bottom locking piece and the bottom locking piece are assembled, a groove forms a closed cavity, severe expansion pressure of gas in the cavity rises when welding is heated, in the welding process, the gas in the closed cavity can seriously disturb a welding pool and influence the stability of a small hole of laser welding to cause the problem of air hole of a welding line, therefore, a circle of air guide hole is designed at an attaching surface A and can be communicated with the closed cavity and the outside of a product, when the laser welding is heated to expand and is cooled to shrink, the gas in the cavity freely breathes to circulate, the pressure in the cavity is kept stable, the laser welding pool and the small hole cannot be disturbed, and meanwhile, heat input or excessive substances cannot be generated in the inner space of the product.

Those skilled in the art will appreciate that, in addition to implementing the system and its various devices, modules, units provided by the present invention as pure computer readable program code, the system and its various devices, modules, units provided by the present invention can be fully implemented by logically programming method steps in the form of logic gates, switches, application specific integrated circuits, programmable logic controllers, embedded microcontrollers and the like. Therefore, the system and various devices, modules and units thereof provided by the invention can be regarded as a hardware component, and the devices, modules and units included in the system for realizing various functions can also be regarded as structures in the hardware component; means, modules, units for performing the various functions may also be regarded as structures within both software modules and hardware components for performing the method.

The foregoing description of specific embodiments of the present invention has been presented. It is to be understood that the present invention is not limited to the specific embodiments described above, and that various changes or modifications may be made by one skilled in the art within the scope of the appended claims without departing from the spirit of the invention. The embodiments and features of the embodiments of the present application may be combined with each other arbitrarily without conflict.