What does a 17th century Japanese craft of creating mechanical dolls have to do with automotive manufacturing? How can it help us reduce our production carbon footprint? What impact does it have on employee productivity? We look at karakuri and how it has become an integral part of the Toyota Way.
Carbon-free manufacturing with karakuri
The intersection of traditional crafts and modern engineering on the road towards carbon neutrality.
26/09/2023
A marvel of 17th century engineering
Karakuri ningyo – mechanical puppets, or automata – originate in 17th century Japan. They are a marvel of engineering and art. The karakuri puppets can move on their own and perform complex actions thanks to an intricate system that takes advantage of gravity, strings, springs and gears to create movement, without any external power source.
Karakuri kaizen
Inspired by the craft behind the mechanical puppets, we at Toyota have adopted a karakuri kaizen philosophy to improve our manufacturing process, with an idea of simple and energy-efficient design at the heart. In practice, that means that in our factories, employees are coached and encouraged to look for ways to improve their work with low-cost mechanical innovations. Simply put, the workers are empowered to hack their workplace to make their jobs easier. And it is all done in the spirit of kaizen.
Reducing waste, improving safety
In Burnaston, UK, the chassis team used karakuri principles to create a device that delivers break tubes and high-voltage (HV) cables to the members of the factory floor at the most ergonomic position, at the exact time they need it. Concretely, a pallet, preloaded with the parts is moved down a conveyor by gravity to a dolly close to the fitting position. Then, the dolly’s rotating arm synchronises with the vehicle carrier which pulls it along the line while members fit tubes and cables. Once empty, the dolly returns to starting position using a spring.
Low-cost automation on a large-scale
Karakuri isn’t always small. Our colleagues from the Toyota factory in Kolin, Czech Republic , built a low-cost, low-energy solution – a Mongata - that carries heavy boxes with parts from Jundate area to the main line. In Jundate, parts, such as radios, tachometer and heater controls, are prepared sequentially for the dashboard part of the line. Before, an operator would prepare the parts, hand them to another operator who would then transport the dolly to the IP (dashboard) line across the logistics route, for around 5 meters.
“The old system was always at the risk of conflict between logistics vehicles and operators. Our staff analysed the situation to solve this issue with a better solution. They started working on prototypes of the different parts of the future Mongata to verify its feasibility and operability before final construction. They then embarked on the complete construction of the Mongata at their site, using electricity, air and karakuri.”
Ladislav Kovařík, Assy engineer at TMMCZ
Now, the operator loads a box to an elevator. The elevator uses electricity to pull the box to 2.5-meter height, and then, using a karakuri mechanism passes it onto a roller track. From there gravity, pulleys, cables and weights take control and deliver the box over and down to the IP line. The Mongata system has been in use for over 2 years now, and it has significantly reduced traffic on the logistics route and optimised workflows and productivity of the entire factory floor.
Towards a carbon-neutral manufacturing
At Toyota Motor Europe, we aim at a carbon-neutral manufacturing in Europe by 2030. And karakuri is one of specific tools we have at our disposal to help achieve it. Beyond being a low-cost alternative to some complicated automations and robotics support, it also uses no or very little energy, this way having a concrete impact on our carbon emissions.
People-driven innovation
In addition to being a great solution to reduce our carbon footprint, karakuri also plays an important role in reducing overwork and waste on the factory floor, and improving safety and productivity of our staff members. And since innovation always stems from our people, the simpler their work is, the more they can innovate. This is central to our signature Toyota Production System.
