Precise control of fuel distribution How Bosch is using tiny, laser-drilled holes to reduce emissions Highly efficient combustion

  • Helps stay below strict exhaust-gas standards
  • Efficient use of energy is a Bosch core competence
  • Fuel atomized into minuscule droplets
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  • December 04, 2013
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press release

Stuttgart – Bosch tames the power of lasers to drill tiny holes in hard metal. But why? Gasoline direct injection is a prime example. The holes' unusual properties contribute to particularly good fuel combustion. And that also means a reduction in emissions.

Advantage 1: Tiny droplets, good combustion
Through five minuscule laser-drilled holes, the gasoline is injected directly into the cylinder at high pressure (200 bar). The sharp edges and smooth inner walls of the holes ensure that the fuel is atomized into extremely small droplets. This is exactly the effect desired. The finer the spray achieved, the greater its surface area. This leads to particularly good contact with the oxygen in the air. On ignition, therefore, the gasoline burns almost entirely.

Advantage 2: Deliberate control
For efficient, clean combustion, it is important to prevent droplets of injected fuel from being deposited on the walls of the cylinder or the surface of the piston. Such deposits result in poor-quality combustion. By drilling the five holes in the injection nozzle with different diameters, Bosch achieves the best possible control over fuel distribution in the combustion chamber. The diameters range from 0.25 millimeters down to 0.1 millimeters. The smallest openings allow less gasoline though, the larger ones slightly more. This creates a specific spray pattern in the cylinder, enabling the fuel to be used to maximum effect.

Advantage 3: Economical concept
“Manufacturing using ultrashort laser pulses is crucial for creating this special hole geometry. And without them, it would not be possible to drill holes of various diameters into the same nozzle in a single step,” says Dr. Rolf Bulander, member of the Bosch board of management. His responsibilities include quality and powertrain technologies. “In this way, laser-based manufacturing helps to reduce fuel consumption in gasoline direct injection by as much as 20 percent compared to conventional port fuel injection,” Bulander says. This also helps engines stay within the strict exhaust gas standards of the future.

Invented for life
“Efficient use of energy is one of our core competencies,” says Dr. Volkmar Denner, chairman of the Bosch board of management. “Many of our 1,300 researchers are working on new solutions in this field every day. At Bosch, there is a common denominator for all their efforts – Invented for life.”

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The Bosch Group is a leading global supplier of technology and services. It employs roughly 375,000 associates worldwide (as of December 31, 2015). The company generated sales of 70.6 billion euros in 2015. Its operations are divided into four business sectors: Mobility Solutions, Industrial Technology, Consumer Goods, and Energy and Building Technology. The Bosch Group comprises Robert Bosch GmbH and its roughly 440 subsidiaries and regional companies in some 60 countries. Including sales and service partners, Bosch’s global manufacturing and sales network covers some 150 countries. The basis for the company’s future growth is its innovative strength. Bosch employs 55,800 associates in research and development at 118 locations across the globe. The Bosch Group’s strategic objective is to deliver innovations for a connected life. Bosch improves quality of life worldwide with products and services that are innovative and spark enthusiasm. In short, Bosch creates technology that is “Invented for life.”

The company was set up in Stuttgart in 1886 by Robert Bosch (1861-1942) as “Workshop for Precision Mechanics and Electrical Engineering.” The special ownership structure of Robert Bosch GmbH guarantees the entrepreneurial freedom of the Bosch Group, making it possible for the company to plan over the long term and to undertake significant up-front investments in the safeguarding of its future. Ninety-two percent of the share capital of Robert Bosch GmbH is held by Robert Bosch Stiftung GmbH, a charitable foundation. The majority of voting rights are held by Robert Bosch Industrietreuhand KG, an industrial trust. The entrepreneurial ownership functions are carried out by the trust. The remaining shares are held by the Bosch family and by Robert Bosch GmbH.

Additional information is available online at and,

PI8319 - December 04, 2013

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