Renault Trucks uses 3D-printed parts to cut engine weight
The Renault Trucks Powertrain Engineering department in Lyon is developing 3D-printed metal to reduce the size and weight of an engine. Its prototype reduced the weight and number of components in the DTI 5 engine by 25%. "Additive manufacturing releases us from constraints and unlocks the creativity of engineers," said Damien Lemasson, project manager. "The procedure is a source of disruptive technology for the engines of tomorrow, which will be lighter and more functional, thereby offering optimal performance," he said.
Renault has designed a prototype DTI 5 4-cylinder Euro 6 step C engine for 3D printing production; the ability of additive manufacturing to produce complex forms resulted in a 25% reduction in the number of components in the DTI 5 engine—a total of 200 fewer parts. The Renault engineers have also manufactured rocker arms and camshaft bearing caps by metal 3D printing and successfully bench-tested these for 600 hours inside a Euro 6 engine.

The Renault Trucks Lyon Powertrain Engineering department is developing metal additive manufacturing—i.e., 3D metal printing—as a future engine manufacturing process. The aim of this project is to demonstrate the positive impact of metal additive manufacturing on the size and weight of an engine, said Damien Lemasson, project manager at Renault Trucks.

This process has enabled us to reduce the weight of a 4-cylinder engine by 120 kg or 25%. The tests we have carried out prove the durability of engine components made using 3D printing. It’s not just cosmetic. —Damien Lemasson



Left: A conventional Renault Trucks DTI 5 Euro 6 engine, 841 parts. Right: the same engine exclusively designed using 3D metal printing to reduce weight and number of components. Click to enlarge.

Metal additive manufacturing opens up new development opportunities for thermal engines. This printing process, which works by adding materials layer after layer, can be used to create complex organic forms, as well as optimizing the sizing of parts and reducing the number of assembly operations and therefore the number of components in an engine.

Additive manufacturing releases us from constraints and unlocks the creativity of engineers. This procedure is a source of disruptive technology for the engines of tomorrow, which will be lighter and more functional, thereby offering optimal performance. —Damien Lemasson



Top: A Renault Trucks Euro 6 DTI5 rocker arm. Bottom: A rocker arm manufactured by 3D printing on a bench test inside a Euro 6 engine. Click to enlarge.

For haulage companies, metal 3D printing carries a number of advantages. They will be able to optimize the overall operating costs of their fleet of vehicles, as a reduction in engine volume will lead to greater payloads and lower fuel consumption.

In the short-term, this manufacturing procedure can be used for highly specific applications or small runs. Following on from these successful initial tests, engineers at Renault Trucks will be continuing their work on this manufacturing process to further increase the performance and functionality of truck components.