Automation transformation and upgrading of traditional spot welding process in home appliance industry
The spot welding process is an important process in the production process of home appliances, which can achieve the purpose of closely connecting different metal plates. With the continuous implementation of automation in the home appliance industry, stamping, injection molding and other sectors have been upgraded to varying degrees. The work intensity and operating environment of employees have been greatly improved. However, the spot welding process is still difficult to implement, and the industry is still using traditional Manual spot welding is the main task. In the past two years, our company has successfully realized the automatic transformation and upgrading of traditional spot welding process through planning and R&D design.
Traditional spot welding process
In the air conditioner, some parts such as the bottom shell assembly, the rear plate assembly, the motor support frame, etc. (Figure 1) are manufactured by manual spot welding of multiple sheet metal parts and metal bolts. Each product is manufactured according to the parts The degree of complexity is different. It requires spot welding of two to dozens of welding points. The production of each product requires multiple people to use an intermediate frequency spot welding machine for spot welding operations (Figure 2). “The working environment of employees is poor, and it consumes a lot of manpower, so there is an urgent need for technology research and development to realize automation.
Process automation upgrade
In order to improve the current situation of traditional manual spot welding that is time-consuming and laborious and the working environment is poor, the project team puts forward the technical improvement idea of ”mainly automatic riveting, supplemented by automatic spot welding” through the research and analysis of components in air conditioner products, which lasted two years Many, realized the automatic transformation and upgrading of the traditional spot welding process of all products.
Figure 1 Some components of an air conditioner
Figure 2 Product spot welding process
For larger components, such as bottom shell components and back plate components, they are in contact with sheet metal surfaces, and the contact area is large, usually the width of the contact surface is not less than 16mm. The products produced by the spot welding process are shown in Figure 3. For these components , We have made process changes and realized a variety of riveting processes (Figure 4) to replace the traditional spot welding process for home appliances, which directly improves the working environment of employees and further improves product quality.
Automated production line
After the process improvement was achieved, the project team planned for different products and implemented automated riveting lines. These lines include line bodies, conveyors, manipulators, riveting mechanisms, robot stacking, etc. The entire automation line has only One employee is required to carry out simple loading work. The rest of the processes such as production, stacking and loading are all automatically completed by manipulators and robots. In traditional manual spot welding production, each line requires 5-6 people to collaborate Finished, the following takes the production of a bottom shell component product as an example to introduce.
Figure 3 Spot welding process products
Figure 4 Riveting instead of spot welding products
The air conditioner bottom shell component is made up of 1 bottom shell, 2 stops, 2 feet, and 3 compressor bolts. The traditional spot welding method requires multiple people to work at the same time (Figure 5), and material loading is required. , Spot welding stopper, spot welding footing 1, spot welding footing 2, spot welding bolts, blanking and loading, etc. 6 processes, the product is complex and there are many processes.
After research by the project team, a flow automated production line for bottom shell components was put on the ground. As shown in Figure 6, this line adopts TOX riveting technology. By establishing a double-layer multi-station circulating flow body, special product carriers are made, and manipulators and robots are configured. , Realizing the automatic riveting production of products.
The specific work flow is: manual loading at the beginning of the line → automatic bolt spot welding → automatic block riveting → automatic footing riveting 1 → footing automatic riveting 2 → robot automatic stacking and loading, the entire process only needs 1 employee to carry out the loading The production process of the automatic line is shown in Figure 7.
Actual production and effect
Figure 5 Manual production mode of bottom shell components
Figure 6 Example of automation line
Figure 7 Production process of automated process
The employee puts the bottom shell product of the air conditioner in the fixture of the wire body, and at the same time places 3 bolts and stoppers on the corresponding part of the fixture, and the product moves on the wire body with the fixture and moves to the stopper of the spot welding station , From this station, the robot grabs the jig with the product and moves to the spot welding machine to automate the spot welding of the three bolts. After the bolt spot welding is completed, the robot puts the jig back to the line body and moves to the stop for riveting Station, this station manipulator grabs the jig and performs the stop riveting operation on the product, and the footing riveting is also completed in the subsequent process.
After completing all the automatic spot welding and automatic riveting production processes of the product, the finished product is moved with the jig to the end of the automatic line body, and then the robot carries the special fixture to complete the automatic receiving and automatic loading of the finished bottom shell component.
Using this idea of changing spot welding to automated riveting, the project team has successively landed a number of automated riveting production lines for bottom shell components of different types, and at the same time, further project research, gradually realizing the automated riveting production of other products, and realizing the traditional spot welding area. Significant improvement.
With the continuous development of technology, through the development and introduction of new connection technologies, and the development of corresponding automation lines, the traditional manual spot welding process of the home appliance industry can be upgraded, which will greatly improve the working environment of employees and the consumption of production materials. Realize downsizing and increasing efficiency, further improve the level of factory automation, and at the same time help realize the transformation of manufacturing employees from direct operators to automated skilled workers.