Mobility Solutions

Vehicle exhaust sensors New generation of lambda sensors Series production of LSF Xfour starts

  • Faster response behavior following engine start
  • High temperature resistance and optional thermal shock protection
  • New LSF Xfour switching-type sensor takes up less installation space
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  • August 18, 2011
  • Mobility Solutions
  • Press releases

press release

With the emission limits in exhaust legislation becoming ever stricter, exhaust sensors are becoming increasingly important. At the same time, automakers are becoming increasingly demanding with respect to sensors’ installation space, measurement accuracy, and robustness. For this reason, Bosch is continuously driving the development of lambda sensors forward. It is now launching the LSF Xfour, the successor generation of the tried and true LSF4.2 switching-type sensor. The new lambda sensor is smaller and more robust, and its measurement accuracy has been improved. In addition, it responds faster following a cold start.

Faster and more accurate, smaller and more robust
Compared with the LSF4.2, it takes half as much time to reach control mode following engine start. This significantly reduces the amount of time in which the engine’s emissions are uncontrolled. Combined with greater measurement accuracy, this will make it easier to comply with future exhaust standards. In addition, environmental impact is reduced. As overall length is shorter, the amount of installation space needed for the entire sensor assembly has been significantly reduced, while increasing temperature resistance at the same time. As a result, there is greater choice when deciding where to install it in a passenger car’s exhaust tract. All variants of the sensor element can be equipped with a thermal shock protective coating as an option. This improves the sensor’s resistance to condensation in the exhaust tract following a cold start.

Multifunctional exhaust sensor, simple principle
Upstream of the catalytic converter, and occasionally downstream of it, the lambda sensor measures the oxygen content in the exhaust. This is an indicator of combustion quality. For one kilo of gasoline to be burned completely, roughly 14.7 kilos of air are needed. The ratio of the mixture in the combustion chamber to the optimum mixture is known as lambda. Conventional gasoline combustion processes ideally operate at a setting of “lambda equals one.” If lambda is smaller than one, the mixture is rich, with too little oxygen. If the ratio is greater than one, combustion is lean, with an excess of oxygen. This is the case with diesel engines, for example, or lean-burn gasoline engines. The switching-type sensor, which delivers an abrupt sensor signal when it detects a transition from a lean to a rich mixture, allows the optimum stoichiometric air-fuel mixture (λ = 1) to be set precisely.

Mobility Solutions is the largest Bosch Group business sector. In 2015, its sales came to 41.7 billion euros, or 59 percent of total group sales. This makes the Bosch Group one of the leading automotive suppliers. The Mobility Solutions business sector combines the group’s expertise in three mobility domains – automation, electrification, and connectivity – and offers its customers integrated mobility solutions. Its main areas of activity are injection technology and powertrain peripherals for internal-combustion engines, diverse solutions for powertrain electrification, vehicle safety systems, driver-assistance and automated functions, technology for user-friendly infotainment as well as vehicle-to-vehicle and vehicle-to-infrastructure communication, repair-shop concepts, and technology and services for the automotive aftermarket. Bosch is synonymous with important automotive innovations, such as electronic engine management, the ESP anti-skid system, and common-rail diesel technology.

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.”

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PI7456 - August 18, 2011

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