In an industrial context, the word automation is often, inaccurately, used to mean only industrial robotics. In fact, it refers to everything from inverter driven conveyor systems to advanced manufacturing software. But it also has a meaning outside the world of industrial engineering.
Here, in its truest sense, it means controlling a process automatically; without human intervention. It’s little wonder then that Ricoh, one of the world’s leaders in office automation solutions, applies that ethos holistically across its business. One example of this is its investment in industrial robotics at its manufacturing arm, Ricoh UK Products Ltd in Telford, which has improved profitability and increased efficiency.
As one of the largest IT companies in the world, Ricoh’s reputation as a provider of printer products is well established. For instance, the company was the first to introduce the digital copy machine. Its product range now spans scanners, colour and black and white laser printers, digital connectable colour and black and white copiers, multifunctional copiers, network utility software, document management software, facsimile machines, digital stencil duplicators and office consumables. The objective of all the company’s products is to help organisations improve the quality and productivity of their office communications.
The company’s holistic approach to automation and efficiency was demonstrated when it began building a new production line for colour toner cartridges to be used on one of its office machines. Ricoh began by investigating a way of using industrial robotics to make manufacturing the toner cartridge shutters a simple process.
“In the past, pick and place activity was done by pneumatics or by hand,” explained Matt Talbot, one of the company’s design engineers. “We had never put an industrial robot project into practice on this level before, although we had used other industrial robots. In the past, they were always part of a turn key solution, however for this application we decided against this approach as the old robots were expensive and their application vague. Prior to this our background had been small assembly jigs. As a result, this project was a big learning curve but a really positive one.”
Ricoh approached Evershed Robotics initially, who suggested using a combination of a Shibaura Machine TH650 SCARA robots, a Shibaura Machine Cartesian robot to work with their six bowl feeders and a rotary index table.
According to Talbot, the product being manufactured is considered high volume by Ricoh. The objective of the automated element of the line is to assemble a shutter to open and close the cap on the cartridge. The shutter itself contains five parts which have to be assembled.
To meet the production demands Ricoh has to assemble the shutter in 7.5 seconds. The company uses a rotary table, surrounded with various pieces of automated equipment, to assemble the device. The intention in incorporating the robots was to load and unload the table itself. After the parts are removed from it, they are stacked in trays, before being moved on into the next element of the assembly line. Over all control is managed by an Omron PLC, which communicates easily with the Shibaura Machine SCARA.
“The parts are quite delicate,” offered Talbot. “Some of the seals can be easily dislodged so we needed quite a precise system. The SCARA robot uses sensitive parallel grippers to pick a raw body from a bowl feeder and place it on the table. Then, from the next unit clockwise around the table it picks up a completed assembly. This assembly is then rotated through ninety degrees so it’s in the correct position to be packed and secured. To do that process with pneumatics would have been a nightmare – we have 72 positions on the packing tray!”
The packing trays are located on a Cartesian robot arm, held there using a vacuum attachment, and the 72 units are arrayed in rows of eight by nine. This robot arm presents the tray to a common position and it stays there until it’s completely loaded. The tray is then replaced back into the magazine from which it came. The Cartesian then selects the next tray down, moving down its vertical axis.
The magazines are replenished manually and the full trays are taken out and stored or moved onto the next step of the process. To ensure personnel safety, there are a series of light guards to stop the operator opening the door. If the door is opened, the robot is prevented from entering the area by the light guards.
“This application needed the speed of a SCARA robot,” outlined Gary Parkes, technical director of Evershed Robotics. “In fact, in this case, the robots aren’t the limiting factor as far as speed is concerned. They could do more if the rest of the system could match them!”
Because the throughput of the system is so high, reliability is crucial at Ricoh. There is a constant demand for cartridges and a failure in production could lead to significant problems in the supply chain. To avoid such problems, Ricoh UK Products keeps a stock of finished components in case of system break down. The SCARA line runs six days a week, with three shifts per day, and the stock is sufficient to cover a breakdown of up to three days in case anything goes wrong here, on the ink filling lines or in the vacuum moulding machines.
To mitigate for technical problems on the shutter assembly line, on which the robots work, Ricoh have been supplied with a comprehensive set of basic spares, such as belts, batteries and sensors. There is also a stock of completed parts and another cell using a TH450 Shibaura Machine SCARA, which can overproduce if necessary.
The installation of the system was exceptionally straightforward, with mechanical installation taking just half a day. According to Talbot, wiring and testing took nearly a week and further developments in reducing cycle time and improving system efficiency accounted for no more than a couple of additional days. The system has more than paid back its installation time in improved efficiency already.
“Without the robots and the automation, the cost of doing this job manually would be very high, and the quality of the assembled parts could not be guaranteed,” explained Talbot. “Also, because it’s so intensively repetitive, this kind of job is made for automation. However, while it was cost that originally prompted us to invest in robotics, we have since become keen advocates of their simplicity, reliability and profitability. So much so that we’ve expanded other areas of the line and added three other SCARA robots at the heart of separate systems. What is more, we are planning to continue working with TM Robotics and Evershed and have recently bought the first Shibaura Machine 6-axis robot the company has sold in the UK.”
More information on the industrial robots used in this project can be found here.