According to Bosch, the complexities of an automatic transmission makes deployment of a start/stop system slightly more difficult. As Bosch points out, modifications for auto trans applications include adjustments to the system's electric starter motor and ECU modifications that make the starting process faster and more dynamic. Bosch claims its start/stop system can cut fuel consumption and emissions by up to eight percent in urban driving. The start/stop system utilizes many existing components which makes it a cost-effective solution for increasing fuel efficiency. Follow the jump for more info on Bosch's modified start/stop setup.
Start/stop systems now also for automatic vehicles
Starter-based solution the system of choice in the market
· Start/stop systems available for different types of automatic transmissions
· 1.5 million vehicles with Bosch start/stop technology sold since series start at the end of 2007
· Up to 8 percent less CO2 and fuel consumption in urban traffic
Bosch has already sold 1.5 million start/stop starters motors since they went into series production at the end of 2007. To date they have mostly been used in vehicles with manual transmission. Together with automakers, Bosch has now modified start/stop technology so that it can also be used reliably in automatics – for example, in the Volkswagen Passat and in the Porsche Panamera with dual-clutch transmission; in the Fiat 500 in combination with an automated manual transmission; and in the Audi A8 with torque converter clutch. Bosch studies show that start/stop systems reduce fuel consumption and therefore CO2 emissions in the New European Driving Cycle (NEDC) by up to 5 percent, and in the NEDC urban component by as much as 8 percent.
In vehicles featuring automatic transmission, the start/stop function is especially easy to use. The driver only has to step on the brake pedal, and as soon as the car has stopped the engine stops automatically – and it starts again when the brake pedal is released. This is very convenient for the driver, who only has to step on the gas and brake. For engineers, however, it is also a challenge to make the start process faster and more dynamic, as the time for declutching, changing gear, and re-engaging the clutch is not available in an automatic vehicle. To solve this challenge, Bosch engineers adjusted the powerful electric motor, the starter's quiet, enhanced pinion-engaging mechanism, and the injection system. Modifications to the control software were done in collaboration with automakers. The battery sensor, a DC-DC convertor, and a deep-cycle battery all remain unchanged in the system.
Start/stop systems, which largely use existing components such as the starter motor and engine control unit, can be quickly and cost-effectively adapted to different engines and vehicles, which is why this starter motor-based method has now become the system of choice for nearly all European automakers -with Bosch as the supplier in most cases. Efficient generators that charge the battery as fast as possible are an ideal addition to start/stop systems, since they allow the start/stop function to be used more often. Bosch added Efficiency Line generators to its product line at the beginning of the year. "Both technologies are elements of Bosch's Efficiency Plus Solutions. Together, they enable fuel-consumption savings of up to 10 percent in urban traffic," says Dr. Ulrich Kirschner, president of the Bosch Starter Motors and Generators division.
The Bosch Group is a leading global supplier of technology and services. In the areas of automotive and industrial technology, consumer goods, and building technology, some 275,000 associates generated sales of 38.2 billion euros in fiscal 2009. The Bosch Group comprises Robert Bosch GmbH and its more than 300 subsidiaries and regional companies in over 60 countries. If its sales and service partners are included, then Bosch is represented in roughly 150 countries. This worldwide development, manufacturing, and sales network is the foundation for growth. Each year, Bosch spends more than 3.5 billion euros for research and development, and applies for some 3,800 patents worldwide. With all its products and services, Bosch enhances the quality of life by providing solutions which are both innovative and beneficial.
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 can be accessed at www.bosch.com.