Industrial assembly requires the components, fastening methods, operator actions and methods of production control to be compatible with each other. A tool does what it is designed to do. However, if there is variation in the fastening results of the tool in a demanding process, problems occur, especially if the cycle time surpasses the production targets.
In choosing equipment for your plant, be sure to consider all of the steps of the assembly process, as well as the product quality, safety in the workplace, maintenance and consistency of performance. This provides you with a larger view to pick out weak spots before they affect production.
While some standard tools serve as good guidelines, in view of the common performance and how they are used, every product has its own requirements for tolerances, fastening forces, access and inspection.
The result of using tools without considering these points may mean that you will have to do unnecessary rework or will severely restrict your production capacity. This type of problem can be avoided by viewing the assembly tool as a member of a team working together, with application engineering connecting equipment with the processes.
Application engineering connects tools with real production needs
Selecting a tool that is appropriate for your requirements goes beyond just looking at the specifications or whether your equipment has enough power to perform the task. You must also be familiar with the physical properties of the assembly, including the materials used, how well the joint needs to perform, and the conditions under which the workers are going to carry out the task.
Today, Atlas Copco ITBA, which is part of Industrial Technique, has the ability to offer industrial assembly solutions through application engineering. With Application Centers, Atlas Copco brings professionals to work together to implement solutions through established core products that combine proven equipment with some additional configurations.
This enables you to assess whether the application requires particular devices, other fixtures, changes in control parameters, or integration with other equipment. From this point, engineers can evaluate joint accessibility, tolerances, production volumes, and workstation limitations prior to moving equipment to the production site.
Last but not least, Atlas Copco’s Innovation Centers offer assistance in the development of joining processes, feasibility testing, time assessments, and evaluation of materials. All these elements give you practical information regarding your solution and identify limits.
Precision, process control and repeatable quality
Fastening illustrates the point that using good equipment does not guarantee good joints. When a bolt is tightened, the resulting clamp load can be affected by friction, joint rigidity, nut design, and material properties, among many other things.
Although torque appears to provide a convenient means of measurement, it can yield different clamp loads for the same applied torque depending upon friction conditions. Design an appropriate fastening strategy, choose the correct parameters, and confirm that the process satisfies the actual joint design, using calibrated equipment systems to ensure reliable results.
Current fastening systems such as electric or pneumatic equipment, controllers, and sensors can be used to combine fastening results quickly and easily. The equipment can monitor torque levels and angles, flag results that exceed the specified limits, and track measurements related to individual parts of selected production runs, depending upon the nature of the fastening application.
The fastening process can be used in conjunction with powered tools, controllers, and software to keep track of fasteners as they are applied. Depending on which method is chosen, the technician can track torque and angle measurements as they are taken, monitor the accuracy of the system, gauging the degree of variation from the specified parameters for each of the installed fasteners.
When establishing the correct amount of monitoring for your fastening process, you need to consider the consequences of an undetected failure, the level of traceability required in your industry, and what information your quality group needs in order to investigate a problem.
Integration, automation and production traceability
Assembly workstation seldom operates independently. Therefore, it is essential to analyze how it exchanges information with other systems. It can involve connection of tools to programmable logic controllers, production management system, robotic equipment, inspection stations and many more.
If there are no suitable integrations, the operators can be forced to enter data multiple times, maintain disjointed records or face interruptions due to incompatible interfaces. Before designing systems, the engineering team needs to investigate communication protocols, control sequences, fault management and maintenance access. If all these aspects work together, the production process becomes coordinated.
Traceability is even more beneficial in the case of production of safety-critical components or complex supply chains. Associating fastening measurements with a product identification number or production order helps investigate defects and locate affected units. Collected data can help in revealing repeating failures, tool efficiency and ways of shortening time cycles.
Nevertheless, measurement collection will be successful only if its information is reachable, exact, and interpreted in the right way. It is crucial to understand what parameters need to be observed, how long records should stay in force and who is allowed to access them.
Ergonomics, safety and the human operator
During your assembly system’s operation, the operator’s comfort needs to be taken into consideration. Vibration, grip design, tool weight, reaction force, and workstation height affect the comfort of the operator and his/her physical load. The use of a powerful tool can be inappropriate if continuous use places an additional load on the operator.
Application engineering takes these factors into consideration through workstation design, equipment selection, and use of various devices like reaction arms, suspended tools, and special fixtures. According to ISO/TS 20646:2014, it is now possible to reduce the workload of a musculoskeletal system. This further emphasizes the human factor’s importance in process development.
Safety is also defined by how the operated equipment works together with the environment and how the operator accesses far and/or dangerous machinery.
All the associated risks must be conducted at the design and commissioning stage and the required safeguards for the selected equipment must be made in training and maintenance guides before production starts.
Lifecycle value extends beyond the purchase price
When you consider purchasing a standard tool, it may initially seem inexpensive based solely on the upfront cost of that tool. However, that price offers minimal insight into the total ownership cost of the tool over its life cycle. Costs for downtime, rework, scrap, repairs, employee fatigue and quality investigations all serve to increase costs.
When looking at an assembly machine, you must factor in the costs for installation, commissioning, training, spare parts and maintenance costs as well. While the initial investment for a machine specifically designed for your application may be greater, in the long run, it can offer greater efficiency due to consistent fastening techniques, speed in finding faults and less downtime. Thus, the best basis for comparison is total cost of ownership.
In addition, considerations of future product requirements should also be made since the introduction of new product lines, new fasteners or increased productivity requirements can limit the future use of equipment designed only for a single purpose. One must also consider such features as configurable controls, accessible documentation, replaceable parts and ease of service when selecting equipment for a new production process.
To aid your team as they troubleshoot problems, keep appropriate records and modify existing work cells to adapt to changing production needs, it is important for technical documentation and maintenance papers to be clear and complete. Thus, having the flexibility to adapt to changes without drastic interruptions to the operation can extend the useful life of your equipment and avoid downtime.
Standard tools offer the important building blocks of your system; however, the knowledge and creativity of engineers transform your components into working systems. Accordingly, by reviewing your applications, work force needs, quality takes and the entire lifecycle of the equipment together, a more informed choice of equipment can be made to achieve quality production.