Assembly Line System Structure

Once the product is assembled and tested it needs to be packed before shipment can occur. Robots can be used to pack finished goods. They can be programmed to pack individual items in different positions on pallets, boxes or trays. Vision systems can be used to guide the robot to pick the part or place the part when the packing pallet or tray does not guarantee the same position always.

Not always a robot is required. If parts can be bulk packed they can be only dropped inside a box. The packing machine can be designed to count the number of parts in a box and when the programmed quantity is reached close the box and begin filling an empty box automatically.

Marking systems enable manufacturers to add important pieces of information (e.g., batch and lot numbers) to parts and products that are essential for quality assurance, traceability, and compliance with regulatory guidelines. They are used to mark manufactured goods in a wide range of industries, including automotive, appliance, consumer goods, and more.

There are many methods to mark a part. As examples we can mention laser marking, ink jet, micropercusion, impact marking, etc.

Leak testing is part of the quality process in manufacturing. It is a critical step when a component or hermetic product is designed to hold liquids or gasses up to a specified limit without leakage. Defects like holes, cracks, inadequate seals, or permeable areas in the material can result in leaks.

There are different methods for leak testing an assembly. The selected method depends on the leak specification of an assembly. The most common method is pressure decay where the assembly is pressurized, stabilized and the pressure decay is measured. In a hermetic assembly pressure decay should be very low.

For very large assemblies it is faster to measure the flow required to keep a certain pressure within the assembly.

For extremely small leak specifications helium leak testing is suggested because of the small size of the helium atom.

For parts that suffer temperature change, like when they are coming out of a welding process and the assembly is cooling, the only available method is the traditional water tank with a pressurized part and bubbles being seen by the operator or detected with sophisticated sound detecting instruments. Even this process can be automated and done at relatively high speeds.

Inspection is usually done without physically touching the part using sensors or vision systems. Dimensions can be inspected as well as the presence or absence of components, the color of a component, the quality of a mark, etc. Implementing advanced testing technology guarantees the highest possible quality standards for your production. The number of out-of-spec parts can be dramatically reduced by implementing in-line testing and inspection during ongoing production, as well as end-of-line inspections. In-line tests offer earlier identification of defective components. Parts that fail partial examinations and meet a set of defined criteria can be disposed of or repaired.

Automated testing systems perform all necessary tests on a device or product without the need for operator intervention or handling. Automated testing technology quickly and accurately performs measurements and evaluates the test results against predetermined criteria to ensure it was fabricated within acceptable standards and tolerances. Testing usually involves mechanically applying and measuring forces or electrical currents to verify compliance with the quality criteria. We have also designed sound testing stations or stations that verify the time it takes for a mechanism to reach a certain position, etc.

A welding robotic cell is where a robot or several robots are equipped with torches and welding equipment to weld an assembly. The cell usually consists of a welding fixture or tool that holds the components firmly in place so that the robots can come in to do the welds. Several factors need to be considered when designing the welding fixture to meet the dimensional tolerances of the part because welding is a process that involves heating the joining surfaces as well as filler metal to melting temperature and then cooling down to harden the joint. This thermal change creates expansion and contraction that can deform the weld and take the final product out of dimensional tolerance.

The cell is usually designed so that the operators load the components in one position and the weld is done in another isolated position thus protecting the operator from the heat involved in the process. Usually the cell has safety guards around and safety elements to protect the personnel.

At AMD we can design custom welding robotic cells for your particular application.

Hot plate welding is a method of joining thermoplastic parts in a permanent, molecular, and frequently hermetic bond. During the process, a heated table called a platen is heated to a specific temperature. Next, the two joining surfaces are brought into contact with the platen for a precise amount of time in order for them to melt before being joined together. A proper hot plate welded joint will be just as strong, if not stronger, than other areas of the part with the added advantage that it can usually correct some of the deformation that can happen in the joining surfaces during the injection process.

AMD designs servo controlled special purpose hot plate welding machines eliminating the need of using hydraulic or pneumatic movements. Servo controlled movements are much more controllable and make adjustments required during the production cycle very easy by using menus on a screen.

Welding is a manufacturing process that is often complicated by the unpredictability of human labor and the inherent risk of error, which is why many manufacturers turn to automated welding systems to improve the productivity and profitability of their welding operation.

A welding robot cell can be used when difficult trajectories are to be welded and this trajectories need to be adjusted depending on the model being produced. However not always a welding robot cell is required. In some applications a dedicated welding machine might be a better and cheaper option. For example, if the product is round and the welding trajectory is always circular a 360 degree welding machine is an option. In this type of machine the part is loaded and it rotates at a constant programmable speed. The torch advances to within an adequate distance of the assembly and begins welding as the part rotates. Welding can be done on a constant weld or spots along the 360 degrees. When the weld is on a straight line also special dedicated machines can be designed without getting into robotics.

Assembly is the process of making a single product by joining several different components together. In order to achieve high production volume the assembly process is split into as many different steps as required, each step making for an assembly station within an assembly line or an assembly machine, depending on the actual product being manufactured.

Within the assembly line in the initial stations the material can be machined or welded and then cleaned or prepared for the rest of the process. The next steps is where the actual assembly of the different components occurs and this forms usually the middle section of an assembly line. At the end we usually have testing stations where the assemblies are verified so that we are certain they all meet the required quality specifications. At the very end parts are usually marked for traceability and packed for delivery to the customer. This is the general sequence of an assembly line but it is usually modified to accommodate the particular product process requirements.

AMD has designed special purpose machines that offer high pressure washing with either oil or water to remove metal particles or carbon from parts that could contaminate and damage the final product. The oil or water can be heated and can go up to 2,000 PSI pressure. After washing away any residues from cooling agents, smoke, metal particles that can damage the final parts, AMD’s washing machines can contain an air station that dries away the water or oil. For some applications we have used centrifugal force to eliminate excess oil and leave only a light oil layer to prevent corrosion. Each AMD washing system recycles the water or oil used in each cycle by cleaning the solution with filters, so there is no water pollution into the environment.

Washing systems are usually used after a welding process to remove carbon before further assembly or machining process to remove metal particles or cooling liquids from the part before further assembly.

Common industries that can utilize the washing system for cleaning parts include CNC machining and automotive.

Industrial robotic systems are designed to perform repetitive tasks in a variety of industrial facilities. Industrial robotics can consist of multi-axis robotic arms, automated cells, automated guided vehicles, or conveyance. Today, these systems are highly scalable and flexible to meet the specific needs of various applications. Operators can also easily reprogram these systems in the event of increased demand, product changes, or seasonal changes. This combined accuracy, flexibility, and scalability makes industrial robotics ideal for use in worldwide production lines of low to high volume. AMD creates customized robotic cells involved in processing, including stapling, gluing, packing, assembling, screwing, packaging, marking, printing, quality checks, and much more. At AMD we use standard robots made by other robot manufacturers and integrate them into custom roles. It is important to note that robots are not always the solution, when production is very high and variability is low (only one or two product variations are required) building a dedicated single purpose machine may be a cheaper and more effective option. At AMD we can advise you on the best option.

Another issue that you have to take into account when thinking on using Robots is that parts need to be “automation quality”, this means that the quality of the components need to be very stable and uniform. A human operator is able to make small tweaks to correct for part variation when nonconforming parts arrive but a robot is not able to do this. The robot will always repeat the task exactly the same and this requires the parts to assemble exactly in the same movement.

AMD provides robotic arms integrated with CNC machining systems that can load, unload and reload into the machine for efficient machining. Within a machining cell measuring stations can be integrated so that feedback loops to the CNC machines are established to compensate for tool wear to ensure that the correct tolerances and dimensions are being met. This integration communicates with and corrects the CNC machine if tolerances aren’t being met, allowing the process to be much more efficient and accurate.

For high volume special machining processes we have designed dedicated CNC single purpose machining stations. An example is for machining the length and cap seats on the extremes of shock absorber tubes with a 3 second cycle time for the whole process.

AMD creates the robotic arms for the handling and loading of parts for heat treatment machines. These robotic arms place each manufactured part into the machine for treatment or tempering. After the process, the robotic arm removes the part to the next process like a balancing machine, stress relief station, machining or assembly process.

Machine feeders work in an industrial factory and are customized to unique specialties. They perform different types of tasks to ‘feed’ or load machines for the manufacturing of products. The function of the feeder is to separate from the bulk or from the package the manufactured parts and place them in a position so that the individual parts can be easily grabbed by the robot gripper or feeding mechanism and fed to the next machine or process. The type of feeder depends on the way the components are received on the assembly line. If they are received in bulk we use custom designed bowl feeders to orient the part and different mechanisms to isolate one part at a time for pickup. If parts come arranged in trays, robots can be used to pick one part at a time. AMD’s machine feeders are custom designed to the particular package, part and process and work with all sorts of machine parts and can run 24 hours per day.