CN214185730U

CN214185730U - Laser welding system

Info

Publication number: CN214185730U
Application number: CN202023262433.4U
Authority: CN
Inventors: 李康为; 张明军; 张焱; 李河清
Original assignee: Changsha University of Science and Technology
Current assignee: Changsha University of Science and Technology
Priority date: 2020-12-30
Filing date: 2020-12-30
Publication date: 2021-09-14
Anticipated expiration: 2030-12-30

Abstract

The utility model discloses a stainless steel laser welding system for pharmacy container, its characterized in that: the laser welding device comprises a laser emitter, an optical shutter, a first laser welding head, a second laser welding head and a third laser welding head, wherein the laser emitter is connected to the optical shutter through a transmission optical fiber, laser is divided into three beams by the optical shutter and is transmitted to the first laser welding head, the second laser welding head and the third laser welding head which are arranged at the tail end of a mechanical arm through a first operation optical fiber, a second operation optical fiber and a third operation optical fiber, the first laser welding head emits a first laser beam which is vertically irradiated to the center of a butt joint of the surface of a workpiece, the second laser welding head and the third laser welding head are symmetrically distributed on two sides of the first laser welding head and form a certain angle with the first laser welding head, and the second laser beam and the third laser beam are obliquely irradiated to the surface of the workpiece; the system can obtain a molten pool with wide bottom during welding, and because the molten pool has large bottom molten width and long molten pool maintaining time, bubbles in the molten pool have sufficient time to escape, so that bottom air holes are effectively improved.

Description

Laser welding system

Technical Field

The invention relates to the field of laser welding, in particular to a stainless steel laser welding system for a pharmaceutical container.

Background

Laser welding has the advantages of non-contact, high efficiency, small thermal deformation and the like, and is widely applied to industries such as automobiles, molds, electronics and the like.

At present, the welding process in the field of pharmaceutical equipment is mainly manual electric arc welding, the welding heat input is large, the polishing workload after welding is large, and the production efficiency is low. The applicant researches and discovers that one of domestic pharmaceutical equipment faucet enterprises, chutian scientific and technological companies, is searching for a laser welding process solution in recent years, finds out multiple laser enterprises on sale at home and abroad, and finally fails due to the fact that porosity cannot be effectively controlled.

Laser welding is a comparatively high-end welding technique at present, but the in-process of laser welding, the gas in the welding liquid can't obtain fine discharge, makes to have the gas pocket in the welding seam easily, and how to make the gas in the welding liquid by abundant discharge when laser welding for most gas pocket is eliminated in the gas welding seam is the problem that we need solve.

As a new technology, the laser welding technology is widely applied due to the advantages of high production efficiency, small workpiece deformation, high welding precision and the like, but in the aspect of welding metal, the welding seam has obvious pore defects, the porosity is about 8-10%, the surface of the welding seam is rough and irregular, and the mechanical property and the air tightness of a structural part are seriously influenced. This is because the induction of a stable keyhole during laser welding requires a higher energy density threshold due to the special physical properties of the metal, such as high reflectivity and high conductivity to the laser, so that the generation of a keyhole during laser welding is easily caused by the instability of the keyhole, the hydrogen solubility in the metal is significantly changed suddenly, the hydrogen solubility in the metal decreases with the decrease in temperature, and the high energy density of laser welding makes the cooling rate of the molten pool of the metal extremely high, and the hydrogen in the molten pool does not escape in time and remains in the weld to form a keyhole. The pore defects generated in the metal laser welding process greatly restrict the wide application of the metal laser welding process in the industry.

Aiming at the problems occurring when stainless steel materials are welded, the following solutions exist in the field of the existing laser welding:

the invention patent with publication number CN 109894745 a, published in 2019, 6 and 18, discloses a welding system for eliminating laser welding air holes, which seals the connecting part of two workpieces by arranging a funnel-shaped shell device, so as to prevent air holes caused by the entrance of outside air to a certain extent, but still prevents many air holes from being generated and cannot be discharged in the welding process due to the problems of air existing in the cavity and poor sealing.

The invention patent with publication number CN 107186336A, published in 2017, 9, and 22, discloses a method for reducing laser welding pores, which preheats a workpiece, wipes the surface with acetone to generate an oxide film, and then welds by using double laser beams, and further reduces the porosity to a certain extent, but the method has too complex operation flow, and the coating layer is used to cause pollution to the medicine to a certain extent, so the method is not suitable for welding medical equipment.

It can be seen that in the prior art, for the problem of air holes in the welding process of the stainless steel plate, especially for the requirement of zero air holes at the bottom of the medical equipment, the method has the defects of poor effect, poor adaptability and the like; therefore, there is a need for a laser welding system for a stainless steel chemical container that is adaptable, easy to control, and has good welding effects.

Disclosure of Invention

The utility model provides a laser welding system aiming at the special requirement of zero porosity of the bottom of the welding seam of the pharmaceutical container, and the shape of the formed molten pool is narrow above and wide below in the welding process; because the melting width is large, the maintaining time of the molten pool is long, so that bubbles in the molten pool have sufficient time to overflow, and the welding device has a good welding effect.

The utility model provides a laser welding system, including following step:

step 1, providing a first workpiece and a second workpiece which need to be in butt joint welding.

And 2, butting and clamping the first workpiece and the second workpiece, and ensuring that the two workpieces are on the same horizontal plane.

Step 3, providing a laser welding system, wherein the laser welding system is provided with a laser, a transmission optical fiber, an optical gate, a first operation optical fiber, a second operation optical fiber, a third operation optical fiber, a first laser welding head, a second laser welding head, a third laser welding head, a protective gas nozzle and a mechanical arm; the first laser welding head is vertically arranged downwards, and the second laser welding head and the third laser welding head are arranged on two sides of the welding seam in parallel and symmetrically, are transversely distributed in the same plane and are fixed at the tail end of the manipulator through the flange plate.

And 4, starting a laser welding system, starting the protective gas, enabling the first laser welding head to be positioned right above the butt joint, emitting a first laser beam, vertically irradiating the surface of the workpiece, and respectively emitting a second laser beam and a third laser beam to be obliquely irradiated on the surface of the workpiece by the second laser welding head and the third laser welding head.

And 5, clamping the first laser welding head, the second laser welding head and the third laser welding head by the manipulator, and synchronously moving the protection gas nozzle along the butt joint to implement welding work.

And 6, when the manipulator moves to the tail end of the butt joint, closing the laser and the shielding gas to finish the welding process.

In one embodiment, in step 1, the first workpiece and the second workpiece are made of stainless steel plates.

Further, the thickness of the first workpiece and the second workpiece is 5-15 mm.

In one embodiment, in step 3, the laser power of the laser welding system is 10 to 20 kW.

In one embodiment, in step 3, in the laser welding system, the included angle α formed by the second laser beam and the third laser beam with the center line of the first laser beam can be adjusted according to the thickness of the plate.

Furthermore, the adjusting range of the included angle alpha is 15-60 degrees.

In one embodiment, in step 4, the power of the first laser beam, the second laser beam and the third laser beam is 5 to 10 kW.

In one embodiment, in step 4, during laser welding, the second molten pool formed by the second laser beam and the third laser beam and the end of the third molten pool are located at the bottom of the first molten pool formed by the first laser beam.

Furthermore, the formed molten pool has small upper volume and large lower volume, and the welding seam is in a shape with a narrow upper part and a wide lower part.

The utility model also provides a laser welding system, including laser instrument, transmission fiber, optical gate, first operation optic fibre, second operation optic fibre, third operation optic fibre, first laser soldered connection, second laser soldered connection, third laser soldered connection, protection gas nozzle and manipulator; the first laser welding head, the second laser welding head and the third laser welding head are fixed at the tail end of the manipulator through the flange plate.

In one embodiment, the laser emitted by the laser is split by the optical shutter and transmitted to the first laser welding head, the second laser welding head and the third laser welding head through the first operating optical fiber, the second operating optical fiber and the third operating optical fiber respectively.

In one embodiment, the angles between the second laser welding head, the third laser welding head and the first laser welding head which are fixed on the flange plate at the tail end of the manipulator can be adjusted in real time according to the thickness of a workpiece to be welded, and the adjustment range of the angles is between 10 and 45 degrees.

Compared with the prior art, the beneficial effects of the utility model are that:

1. the utility model discloses on the basis that first laser beam executed welding, add parallel second laser beam and third laser beam, first laser beam, second laser beam and third laser beam obtain first welding molten bath, second welding molten bath and third welding molten bath respectively in the welding process. The first welding molten pool, the second welding molten pool and the third welding form a welding molten zone, the upper part of the welding molten zone is divided into three independent areas, the width of the bottom of the welding molten zone is increased, the volume of the bottom molten pool of the welding molten zone is increased, and the cooling speed is low, so that the time for the bubbles in the bottom molten pool of the welding molten zone to move upwards is longer, and the generation of air holes at the bottom of a welding seam is effectively avoided.

2. The utility model discloses on the basis that first laser beam executed welding, add second laser beam and the third laser beam that stands by, improved thick plate butt joint's fit-up gap greatly for welding process's engineering adaptability is better.

Drawings

FIG. 1 is a schematic diagram of the arrangement of the apparatus and parent material involved in a laser welding system for a stainless steel drug container embodying the present invention;

FIG. 2 is a schematic cross-sectional view of a weld zone in the method of FIG. 1;

FIG. 3 is a schematic cross-sectional view of a weld in the state shown in FIG. 2;

in fig. 1: 1. the device comprises a first workpiece 2, a second workpiece 3, a laser 4, a transmission optical fiber 5, a shutter 6, a first operation optical fiber 7, a second operation optical fiber 8, a third operation optical fiber 9, a first laser welding head 10, a second laser welding head 11, a third laser welding head 12, a first laser beam 13, a second laser beam 14, a third laser beam 15, a protective gas nozzle 16, a protective gas cylinder 17, and a manipulator

In fig. 2: 1. a first workpiece 2, a second workpiece 3, a first molten pool 4, a second molten pool 5, a third molten pool 6, a first aperture 7, a second aperture 8, a third aperture 9, a first laser beam 10, a second laser beam 11, a third laser beam

In fig. 3: 1. first workpiece 2, second workpiece 3, molten pool

Detailed Description

The technical solution of the present invention will be described in detail with reference to the accompanying drawings 1-3 and the specific embodiments.

In an embodiment of the present invention, as shown in fig. 1-3, a laser welding system for stainless steel for pharmaceutical containers comprises the following steps.

Step 1, providing a first workpiece 1 and a second workpiece 2 which need to be welded, wherein the first workpiece 1 and the second workpiece 2 are both stainless steel plates and can be prepared and formed by a machining method. In this embodiment, the thickness of the first workpiece 1 and the second workpiece 2 is 5 to 15 mm.

And 2, removing impurities on the upper and lower surfaces of the first workpiece 1 and the second workpiece 2, and accurately butting and clamping the first workpiece 1 and the second workpiece 1 to ensure that the first workpiece 1 and the second workpiece 2 are tightly attached, namely the gap between the butting plates is zero.

And 3, providing a laser welding system, wherein the laser welding system is provided with a laser 3, a transmission optical fiber 4, a shutter 5, a first operating optical fiber 6, a second operating optical fiber 7, a third operating optical fiber 8, a first laser welding head 9, a second laser welding head 10, a third laser welding head 11 and a protective gas nozzle 15.

And 4, starting the laser and the shielding gas, and clamping the first laser welding head 9, the second laser welding head 10, the third laser welding head 11 and the shielding gas nozzle by the manipulator 17 to move along the welding path to implement welding work.

And 5, when the manipulator moves to the tail end of the butt joint, closing the laser and the shielding gas to finish the welding process.

The first laser welding head 9 outputs a first laser beam 12 which vertically radiates at the center of the butt joint to form a first molten pool; the second laser head 10 and the third laser welding head 11 are arranged side by side and symmetrically distributed to respectively output a second laser beam 13 and a third laser beam 14 which simultaneously act on two sides of a welding seam to form a second molten pool and a third molten pool. The protective gas nozzle 15 is positioned in front of the molten pool, and 99.995% purity argon is blown out at a flow rate of 15-30L/min to act on a welding central area.

The first laser welding head 9, the second laser welding head 10 and the third laser welding head 11 are fixed by a flange 20 at the end of the robot so as to be in the same plane. The included angles between the second laser welding head 10, the third laser welding head 11 and the first laser welding head 9 are alpha, and the included angles alpha can be adjusted within the range of 10-60 degrees according to the thickness of a welded workpiece, so that the tail ends of a second molten pool and a third molten pool formed by the second laser beam 13 and the third laser beam 14 are just positioned at the bottom of a first molten pool formed by the first laser beam 12, the formed molten pool is small in size above and large in size below.

The embodiment of the utility model provides a stainless steel laser welding system for pharmaceutical container is still provided, send by laser 3 including laser, transmit to optical gate 5 through transmission fiber 4, divide into three bundles of laser by optical gate 5 and export respectively to first operation optic fibre 6, second operation optic fibre 7, third operation optic fibre 8, first operation optic fibre 6, second operation optic fibre 7, third operation optic fibre 8 is connected respectively and is fixed in the terminal first laser welder head 9 of manipulator, second laser welder head 10, third laser welder head 11, first laser welder head 9, second laser welder head 10, first laser beam 12 is launched out to third laser welder head 11, second laser beam 13, third laser beam 14.

The first laser beam focused and emitted by the first laser welding head 9 vertically radiates to the center of the butt joint, the power of the first laser beam is 5-10 kW, and the laser beams focused and emitted by the second laser welding head 10 and the third laser welding head 11 are arranged side by side along the welding direction and are symmetrically distributed, and the power of the second laser welding head is 5-10 kW.

Optionally, the laser welding system further includes a second laser welding head 10, a third laser welding head 11 and the first laser welding head 9, which can be adjusted to have an included angle α according to the thickness of the welded workpiece, and the adjustment range of the included angle α is 10 ° to 60 °.

Optionally, the laser welding system further comprises a shielding gas nozzle 15, 99.995% argon can be blown out to act on the welding center area, and the flow range of the argon is 15-30L/min.

The embodiment of the utility model provides an on the basis that first laser beam executed welding, add parallel second laser beam and third laser beam, first laser beam, second laser beam and third laser beam obtain first welding molten bath, second welding molten bath and third welding molten bath respectively in the welding process. The first welding molten pool, the second welding molten pool and the third welding form a welding molten zone, the upper part of the welding molten zone is divided into three independent areas, the width of the bottom of the welding molten zone is increased, the volume of the bottom molten pool of the welding molten zone is increased, and the cooling speed is low, so that the time for the bubbles in the bottom molten pool of the welding molten zone to move upwards is longer, and the generation of air holes at the bottom of a welding seam is effectively avoided.

Claims

1. A laser welding system, characterized by: the laser welding device comprises a laser emitter, wherein the laser emitter is connected to an optical shutter through a transmission optical fiber, laser is divided into three beams by the optical shutter and is transmitted to a first laser welding head, a second laser welding head and a third laser welding head which are arranged at the tail end of a mechanical arm through a first operation optical fiber, a second operation optical fiber and a third operation optical fiber, the first laser welding head emits a first laser beam and irradiates the center of a butt joint of the surface of a workpiece vertically, the second laser welding head and the third laser welding head are symmetrically distributed on two sides of the first laser welding head and form a certain angle with the first laser welding head, and the second laser beam and the third laser beam are emitted and irradiate the surface of the workpiece obliquely.

2. The laser welding system of claim 1 wherein the first laser weld head, the second laser weld head, and the third laser weld head are held in the same plane by a robot end square flange.

3. The laser welding system of claim 1, wherein the included angle between the second laser welding head, the third laser welding head and the first laser welding head can be adjusted according to the thickness of the workpiece to be welded, and the adjustment range is 15-60 degrees.