The inevitable tide of industrial automation
Toshiba Machine SCARA robots are in use across Europe in countless applications, from the highly regulated pharmaceutical clean room to handling and logistics applications in packaging. Every year, more and more companies are turning to industrial robots to cut costs, improve productivity and increase output.
For instance, three Toshiba Machine TH350 ceiling mounted robots at a pet food factory in Bremen, northern Germany.
In order to maintain the manufacturer's range and improve its productivity, the company has made substantial investment in factory automation. Toshiba Machine robots now package birdseed sticks at a rate of ninety per minute. Where once there were seven people working on the application across three shifts, now three Toshiba Machine TH350 robots achieve the same results. The people have now been re-deployed across the plant.
The SCARA robots are part of a production line that manufactures birdseed sticks that are analogous to a fat based lollypop, embedded with nuts. The birdseed sticks are fed down three conveyors, each with a ceilingmounted SCARA robot at its end. As this happens, the boxes are fed down another conveyor. A robot gripper then picks up the seed sticks and transfers them into boxes on a moving conveyor.
Ceiling mounted SCARA robots make the best use of the available work area. They are perfect for use at the junction of convening conveyors or other areas where space is at a premium. Ceiling Mount makes the best possible use of the robot's working envelope and also saves real estate, which, in turn, saves money. As a result, payback times become quicker and the factory becomes leaner.
Another significant factor in the application was cycle time. In order to match the production rates of the manual version of the line, TM Robotics worked with the pet food manufacturer to specify one of Toshiba Machine's fastest robots.
Another example of manufacturing excellence can be found in Spain, where TM Robotics in conjunction with its key Spanish integrator Maser Robotica SA, has helped Dinalot, a manufacturer of automotive parts, develop a Cartesian robot cell to improve production. The robot has reduced component rejection on a highspeed line that manufactures metal disks for use in vehicle fuel injection systems.
The Cartesian robot works in conjunction with a machine vision system in a quality assurance role. There are five versions of the metal disks, which incorporate six tapped and countersunk holes. Before the process was automated, an operator checked the diameters of the holes and their positions relative to a central notch. This time-consuming process involved selective sampling and, as a result, allowed some non-compliant parts to pass through. "Any process where only a portion of a batch is checked inevitably produces errors," explained Nigel Smith of TM Robotics. "By checking component parts with an automated vision system, the
user can drastically reduce such errors."
The new system uses two vision sensors mounted on the robot arm and a rack mounted PC. The computer controls the sensors and robot, and displays the inspection images and measurement results.
The entire operation at Dinalot now takes just nine seconds, allowing every part produced to be inspected. The data generated by this system has allowed Dinalot to refine other areas of its machining processes, resulting in long-term benefits as well as short-term payback.
Perhaps the most unusual application TM Robotics has been involved in recently can be found in the UK, where robots are applied to test the strength of pipes. Here TM Robotics teamed up with impact testing specialist Imatek Limited to deliver a robot system to handle the task safely for pipes used by a South Korean steel company.
The application uses Toshiba Machine SCARA robots to test large diameter line pipes that will ultimately be used for carrying fluids at high pressure. Preparation for the DWTT (Drop Weight Tear Test) process involves cutting a segment from the pipe, flattening it and putting a notch on one side as a crack initiator. The segment of pipe is then immersed in liquid nitrogen, to cool it to as low as -160°. Placing the pipe in this cooling bath causes embrittlement before the specimen is then positioned on an anvil in a drop-weight testing machine and broken into two pieces.
The tricky bit is moving the pipe specimen from bath to machine and breaking it within the ten seconds allowed by the test method. "This poses a safety problem as an operator cannot be expected to put their hands inside unless the mass is fully supported," explained Richard Sparks, who handles technical sales at Imatek. "However, to achieve the test cycle time required by the standard, the mass instead has to be suspended, ready to drop. As a result we needed an automated solution, where the robot provided sufficient speed to transfer the pipe into position within the drop-weight tester within the required cycle time."
With the specimen in position, a three-tonne weight is dropped from a height of 3.5 metres onto the pipe, striking the opposite side of the segment to the notch. This creates up to 100,000J of impact energy as mentioned already about the same as firing 170, 0.45 calibre handguns at a single spot, or an average man weighing about 140lbs falling 180 metres! In order to ensure that the force is being applied in exactly the right place on the steel pipe, the robot needed to provide positioning accuracy of +/-0.5mm - another reason for choosing the highly precise Toshiba Machine SCARAs.
Usually the operator visually inspects the broken specimen in order to determine mode of failure. This drop-testing machine is fully instrumented ensuring a very repeatable test method. The initial velocity is measured using a proprietary laser system and force is measured during specimen failure to provide the user with force and displacement data from which the quality of the steel can be determined and how well it will operate under pressure. The end result allows the product to meet the demanding quality standards of the American Petroleum Institute.
"We selected the TM Robotics and Toshiba Machine SCARA for a number of reasons," explained Sparks. "Firstly, the robot only had to move in two planes, which is well within the capabilities of the SCARA. In addition, because SCARAs are so compact, the robot fits easily within the available space. We looked at pneumatic alternatives but the solutions on the market couldn't achieve the positioning or repeatability we were looking for. We also looked at servo motion systems as an alternative but the price and performance of the robot solution was way ahead.
"Apart from the technical advantages provided by the product, TM Robotics was also able to help with the application itself thanks to the company's technical knowledge," continued Sparks. "TM's engineers came up with the right robot, trained us in its use and were able to ship at quite short notice. At Imatek we specialise in instrumented drop-weight testers - this includes a lot of work in the automotive and steel industries. However, this is physically the largest project we have done so far, even in this demanding field, so it was important to be able to rely on TM's level of support."
The efficiencies resulting from Imatek's applications, as well the other two, raise the question of what could possibly stop the inevitable tide of robot automation? Perhaps these three case studies suggest that, at least globally, industry is committed to world-class performance? The increased production, higher profitability and improved levels of safety experienced by the companies in question certainly suggest that this is the case.
Case Study originally published on Thu 23 Aug 07 12:36