03 May 2005
03 May 2005
Bosch has started worldwide production of the first throttle device for gasoline engines made from glass fibre reinforced composite material.
The new component weighs 25 percent less and can be produced much more economically than conventional throttle bodies made from metal. The company stated that other benefits of using composites for the throttle body are that there is a more accurate control of the opening angle of the valve, a much easier adaptation to different engines and vehicle models as well as superior crash behaviour, since components made from FRP composites will break into multiple parts under impact.
A spokesperson for Bosch informed Netcomposites that the conventional Bosch throttle body (DV-E5) has been in production since 1997 and made from aluminium. In the last few years, Bosch has been researching new metals and composites for the throttle part. Following testing, the company have opted for the composite part mainly due to the 25 percent reduction in weight over alternative materials.
The throttle body (pictured) is the central actuator to control the intake airflow in an ETC system (electronic throttle control) – thus also determining the power output of the engine. The engine control unit calculates the required opening of the throttle body, the ignition angle and injection volume on the basis of the accelerator pedal position. The throttle body angle sensor monitors the actual position of the throttle body and provides the precise adherence of the throttle body position.
Dr. Elmar Huber, Project Manager of the Composite Throttle Body of the Bosch Division Gasoline Systems said that "the optimized throttle body geometry with a composite compatible design allows for an even more precise control of smallest air volumes, which has a specially positive effect when the engine runs idle or with only small load." Adding that the otherwise necessary connection to the cooling circuit of the vehicle becomes unnecessary, since the low heat conductivity of the composite material greatly lowers the risk of ice formation.
The new generation of throttle bodies with the denomination DV-E8, housing as well as valve, is made of stable glass fibre reinforced thermoplastic material which offers improvements in withstanding higher temperatures and is more wear resistant. The flexible structure of the throttle body makes an adaptation to various engine and vehicle series much easier. Huber Explained: "Touchless sensors or potentiometers will be used, according to demand. Housings and plugs can be combined in any way the OEM requires."