Application Of Laser Welding Technology in Washing Machine Inner Drum

In order to further improve the reliability and refinement of the inner barrel, washing machine manufacturers have applied laser welding technology to new uniform-power washing machines to avoid the occurrence of gaps and unevenness in the inner barrel. While comprehensively improving the reliability of the product, it also takes better care of clothes.

 

At present, the inner liner of high-end washing machines on the market is mostly made of stainless steel, and its thickness is mostly between 0.8mm-1.2mm. When the washing machine is working normally, the operating speed can reach 1400R/min. Therefore, the inner tank of the washing machine has extremely "harsh" requirements for the welds: the welds are smooth and flat (tested by scratching with stockings), and the mechanical strength is high enough (the weld strength cannot be Less than the strength of the base metal), the weld cannot be oxidized or discolored and is corrosion-resistant (it must pass a 2400h salt spray test after welding). SDQY Laser focuses on the research and development and production of laser equipment. With many years of experience in laser equipment research and development, its product technology is mature and its product performance is safe and stable, just to provide customers with better product experience and services.

 

 

Laser Seamless Welding Process Solution for Welding the Inner Barrel of Washing Machine:
1. High requirements for welding seam formation: single-sided welding and double-sided forming, the welding seam and the back side of the welding seam must be continuous, uniform and smooth, without any nodes, burrs, or welding slag, otherwise the smoothness requirements will not be met;

 

Laser Welding Solution: Aiming at the Problem of Nodes at the Starting Point and End Point of the Weld
In order to solve the problem of nodes at the starting point and end point of the welding seam, the laser modulation mode is adopted, and the power slope adjustment function is set in the welding equipment control software. The power ramp-up length is set at the starting point, the power ramp-down length is set at the light-off position, and the power ramp-up function is set in the welding equipment control software. , The node problem at the welding seam of the light-off point has been greatly improved, but there is a depression at the light-off point. The light-off point can be placed 2mm outside the sample. Using the above solution, the problem of uneven welds and nodes can be well solved.

During the welding process, the amount of defocus has a great influence on the weld shape of the sample. If the defocus amount is too large, the laser energy loss will be large, and the weld will be discontinuous and uneven; if the defocus amount is too small, the laser energy will be concentrated, which will increase burrs on the back of the weld (especially thin plate welding). Therefore, in the welding of this sample, on the premise of ensuring the penetration of the material, the defocus amount can be adjusted appropriately to make the front weld continuous and even, and the back weld without any burrs. Burrs on the back not only affect the smoothness of the liner, but also affect the salt spray test effect of the sample.

 

 

2. The Appearance of the Weld Is Extremely Demanding:

There should be no oxidation on both the front and back sides of the weld and the edge of the weld. Otherwise, its corrosion resistance will be reduced and the salt spray test will fail.

Laser Welding Solutions: Ensuring a Smooth Appearance of the Weld Seam
In order to ensure that the weld seam has a smooth appearance and that the produced sample can successfully pass the subsequent 2400h salt spray test, the "shielding gas" during the welding process is crucial. The protection effect is good, not only making the front and back sides of the weld smooth and translucent, but also preventing the weld from oxidation during the welding process and successfully passing the corrosion test. During the welding process, in order to prevent welding slag from adhering to the material surface, a dust removal device can be installed in the welding direction. In addition, the usual single-tube side blowing cannot effectively ensure that the front weld is completely protected from oxidation. Therefore, the front shielding gas should be changed to the exhaust pipe side blowing, which can ensure that the front weld is not oxidized. The back side of the weld must also be slotted and a protective gas added to ensure the welding quality of the back weld.

The above is the solution for laser seamless welding process in welding the inner barrel of washing machine. The inner barrel of washing machine is generally 0.8-1.2mm thick stainless steel sheet. Therefore, it is recommended to use 2000W-3000W fiber laser. The core diameter should be 100μm, and the light spot should be larger. It can make the welding effect better.

Laser seamless welding is Haier's first introduction and comprehensive promotion of the inner cylinder manufacturing process in China. It has reduced the gap of the riveted inner cylinder commonly used in the industry from 8mm to 0.55mm, which is only 10 hairs thick. It is a manufacturing breakthrough in the washing machine industry. Craft revolution. The following introduces the process technology of laser welding technology in the inner barrel of washing machine.

Introducing the process technology of laser welding technology in the inner barrel of washing machines. First, understand the changes in the inner barrel technology of washing machines. In 1928, the world's first drum washing machine was born, and riveted inner barrels have always occupied a mainstream position. Riveting technology uses rivets for mechanical connection. There are often gaps or unevenness in the joints. The resulting 8mm gap can easily cause wear and tear on clothing. At the end of the last century, laser welding technology gradually matured and was first used in precision manufacturing industries such as aerospace, aircraft, ships, and even automobiles. Laser welding technology in the home appliance industry started late. While the industry was still focusing on upgrading riveted inner cylinders, Haier took the lead in researching electric welding and laser welding.

 

Although laser welding and riveting processes are also involved in many fields, these two transition trends are particularly obvious in the field of washing machines. From the perspective of process analysis, the inner cylinder made using laser seamless welding technology is nearly 4 times stronger than the inner cylinder using riveting technology, and the smoothness of the interface is improved by nearly 15 times. The purpose of the smooth seams of the inner cylinder is to better protect the clothing fabrics. This is an experience that is difficult to achieve with riveting technology. It also meets the needs of consumers for quality life under the current trend of consumption upgrading.

 

Laser seamless welding is a fusion connection. Compared with riveting technology, it has higher requirements on the refinement of raw material sheets, welding environment and other aspects. During the welding process, more than ten manufacturing processes, including the burrs and straightness of the inner barrel piece, the matching of tooling fixtures, and the power, focal length, and operating speed of laser welding, must be closely coordinated.

 

The washing machine has the industry's largest drum diameter of 525mm, which not only meets the laundry needs of the same volume and larger capacity, but also greatly increases the difficulty of welding the inner drum. During the welding process, the diagonal size error of the raw steel plate does not exceed 1mm, the tangent accuracy of the inner cylinder is controlled within 0.05mm, and the vertical angle of the slice is controlled at 0.05°. Faced with a 10-fold improvement in the manufacturing accuracy of the inner cylinder, Haier introduced multinational resources from six countries around the world to jointly research product solutions and went through repeated experiments. Finally, the inner cylinder is 0.55mm flat and smooth through extremely fast fusion welding within 0.02 seconds at a high temperature of 1500°. Rubbing the inner cylinder repeatedly with silk will not snagging, and the roses will remain intact even after being washed for 20 minutes. Seeing is believing is an example that proves the ultimate care of clothing by laser seamless welding of the inner cylinder.

 

The above is the process technology of laser welding technology in the inner barrel of washing machine. From traditional riveting to laser seamless welding, it is another innovative iteration of the manufacturing process of the washing machine industry. At present, laser seamless welding technology has become the mainstream trend in the washing machine industry, while traditional riveting technology will continue to shrink with the upgrading of market demand, and then withdraw from the stage of history.