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Modular Fuel Injection System Simplifies Installation and Optimizes Performance
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Since the demise of the carburetor over a decade ago, fuel systems have steadily improved. Today, multi-port fuel injection is the standard method used to deliver fuel to the cylinders in automotive engines. Essentially an electronically controlled valve that squirts pressurized fuel, fuel injectors are refined little devices that require individual electrical connections and exact positioning to operate correctly. In multi-stream fuel injection, individual injectors are installed for every cylinder where they react to the throttle position, injecting more or less fuel into the intake valve in response to the amount of air entering the cylinder. An electro-magnet inside the injector operates a small valve that squirts atomized fuel from a nozzle, setting up the combustion process. How well the injector atomizes the fuel affects combustion and determines overall engine performance.
Common fuel injection technology requires the individual installation of each injector -- a highly labor-intensive process involving plugging each injection valve into the individual intake tube openings and then making the electrical connections. In multi-stream fuel injection, exact positioning of the injection valve in the connection fitting is critical to achieving the correct fuel/air mixture, so great care has to be taken to prevent the valves from rotating in their fittings during installation and operation. To achieve this, individual clamping claws are used to fix each valve in the proper position.
Fast, easy modular installation
In response to this painstaking, valve-by-valve installation process, Bosch has developed a new technology that takes a modular approach to fuel injection. Instead of installing individual valves to the engine, the fuel injectors are mounted on a common connection strip that in turn fastens directly to the engine. All the electrical and valve connections are made precisely and easily. The valves are connected with locking collars that are designed to fit in the exact, correct rotational position, aligning the fuel stream plane perfectly with a predetermined position to optimize the fuel mixture. The electrical lines are coupled to a common connection plug or a cable harness and connected to the electronic control unit (ECU) which controls the combustion process.
Improved cold-starting performance
In addition to simplifying the manufacturing, installation, and maintenance of fuel injection systems, Bosch´s technology also provides for improved cold-starting performance. By incorporating an electric heating element at the fuel jet, Bosch is able to improve fuel atomization, resulting in better combustion, lower exhaust emissions, and reduced fuel consumption. The heating element is mounted on an extension device that is controlled electronically. During the first 120 seconds of cold-start conditions, the heating element is moved into the fuel spray, heating it to optimal combustion temperature after which it is withdrawn.
Bosch´s new fuel injection technology was initially designed for automotive engines, however, it is ideal for in a wide range of combustion engine applications, including power equipment, stationary internal combustion engines, rocket propulsion systems, and any chemical or fuel blending system.
