2010-04-19 - The Swedish company Ljunghäll, based in Södra Vi in the Swedish province of Småland has been in blacksmithing for over 90 years, but now it is using ABB robots to become a leading manufacturer of technically advanced aluminium die-cast products in the Nordic region.
The company employees 106 robots, in 80 different cells, to produce inlet manifolds, oil cooler covers, and engine blocks for clients such as Scania and Volvo, plus equipment for cell phone towers for Ericsson, and even TV pedestals for Bang & Olufsen. Their specialty is in large complex castings.
Ljunghäll has been an ABB robotics customer since it installed its first robot over 20 years ago. And Nicklas Jaldefeldt, Ljunghälls own "robot guru" has been around ever since.
Hundreds of different parts made with flexible robot systems
“We buy so-called ‘naked robots’ and dress them ourselves with our own in-house gripper expertise and cell technology,” says Jaldefeldt. “We manufacture hundreds of different parts for different customers. It is therefore important to build a flexible system where a stop in one cell doesn’t affect the work in another.”
Ljunghäll’s 35,000-square meter factory is basically a collection of 39 different aluminium die-casting machines. These take molten aluminium and press them into parts, the biggest of which uses pressures upwards of 3,500 metric tons per square centimetre.
Adjacent to each of the die-casting machines are the robot cells, which depending upon the part being made either, cut, grease, grind for smoothness, glue, screw, or assemble the parts. They are then dispatched on a conveyor belt to an operator, who checks the quality and packs them.
Robot applications include: machine tending, materials handling, grinding, screw-driving and assembly
“Automation is a prerequisite in our constant striving for cost efficiency,” says Jaldefeldt, who credits his eight-man robot team for the smooth operations at Ljunghäll. “And human handling is our last and best quality check.”
According to Jaldefeldt, there are two related reasons why the company designs and builds its own robotic cells, and doesn’t use a third party integrator. One reason is that Ljunghäll was a family-owned company for many years and was used to doing everything itself.
“But another reason why we dress our robots ourselves is that we have learned what the optimal set-up needs to be next to huge die-casting machines. Handling hot aluminium requires special equipment due to the corrosive environment and our production schedule,” says Jaldefeldt.
Preference for the ABB True View robot vision guidance system
Despite its preference for homemade solutions, one particular cell at Ljunghäll uses ABB’s TrueView vision guided robotics (VGR) system.
The cell consists of two robots – an IRB 6620 and an IRB 6650 – to smooth out the screw holes on a so-called bed plate, which is a 10-kilogram aluminium casting that encloses the crankshaft of an automobile.
The main advantage of TrueView is that the robot can pick up the bed plate from a pallet and actually see and adjust its position according to the bed plate’s actual location, (it could have lost its location during transportation to the cell); before picking it up and moving it to another workstation.
“TrueView is a flexible system that works well in today’s industrial environment where we need to quickly be able to change over to manufacturing other products. TrueView allows the robot to identify different parts on a belt and identify which one is the right one for the job.”
Ljunghäll in brief
- Founded in 1917 by blacksmiths Edvin and Hilda Ljungkvist and now a leading manufacturer of die-cast aluminium products
- 750 employees
- 37,000 square meter facilities in Södra Vi, in southern Sweden
- Annual production: 15,600 tons of aluminium, of which 100 percent comes from recycled aluminum
- Turnover: SEK 1.14 billion
- Supplier to:VOLVO, SCANIA, DAIMLER, ERICSSON, RENAULT, ELECTROLUX, B&O, FORD, JAGUAR, TANDBERG, AUD,I ANDREW
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Benefits of robotization
- Ljunghäll started with robotic production in 1987 and currently has 106 robots in 80 cells. Applications include: grinding, screw running, greasing, trimming, gluing and assemble
- The benefits are primarily ergonomic as the company produces large unwieldy pieces that weigh up to 30 kilograms, and come out of die casting machines very hot every third minute
- Nicklas Jaldefeldt, responsible for the robots at Ljunghäll, says that without robots, even doubling the amount of employees to 1,500 would not be enough to meet current production levels
- Ljunghäll’s range of robots range from the small IRB 140 to the larger IRB 6650.
- TrueView is ABB’s patented Vision Guided Robotics (VGR) technology that allows robots to identify & pick up randomly located parts.
- TrueView can be retrofitted on any robot and does not require optimal light conditions.
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