Exhaust flaps for passenger cars are integrated in the exhaust tract. The housing is either a precision casting or of welded sheetmetal construction. This is ordinarily combined with a DC motor actuator with a contact-free sensor. All actuators for our exhaust gas flaps are internally developed.
For gasoline engines, there is a variant of the diesel exhaust gas flap constructed as an acoustic flap. In this case, particular attention is paid to internal leakage in order to achieve optimum noise minimization performance. A range of different actuators from the Pierburg modular system can be used to control the acoustic flap.
Sheetmetal exhaust flaps or exhaust control valves (ECV) are generally weld-in solutions. They are available in standard versions for tube diameters of 55 mm, 65 mm, and 75 mm. As with all other Pierburg actuators, customer specific electrical connectors are available.
Exhaust flaps for commercial vehicles must be able to resist higher vibration and pressure loads. Commercial vehicle exhaust flaps are also used for a range of different functions: for example, in thermal management, exhaust gas recirculation, braking assistance, or shift assist in automatic transmissions. When it comes to actuators for exhaust flaps, we differentiate between smart and non-smart options.
Smart HD Exhaust Flaps
Smart HD exhaust flaps or back-pressure valves (BPV) are available with various flange solutions for tube diameters of up to 120 mm. Due to the high vibration loads, the actuators installed are decoupled from the flap housing. The control functions are performed by a smart heavy duty actuator that communicates with the engine control unit via a CAN signal. Electrical connections are made with either an integrated connector or a pigtail cable solution. A software layer allows the configuration of special service functions.
Non-smart Light Duty / Medium Duty Exhaust Flaps
Non-smart LD/MD exhaust flaps or back pressure valves (BPV) are available for tube diameters of up to 80 mm with various flange solutions. Due to the high vibration loads, the actuators are decoupled from the flap housing. For this application, we rely on a non-smart DC motor. For electrical connection, you can choose between a range of integrated connectors or pigtail cable solutions. Flap actuation is controlled via a PWM signal.
Sheet metal acoustic flaps or acoustic control valves (ACV) are generally weld-in solutions and are available as “sealed” or “unsealed” options. Customer-specific electrical connectors are naturally also available for these products.
The brushless actuators for commercial vehicles manufactured by Pierburg are optimized for the harsh hot-side engine packaging environment and extended lifetime required of today's commercial diesel engines. They are used in the exhaust gas and fresh air systems of medium to heavy duty vehicles, and in the industrial sector, and actuate flaps and valves up to 120 mm diameter via a CAN Bus with OBD ready software. All of our brushless actuators have a lifetime of 20,000 hours, fulfill ISO 16750, and can be used in 12 V and 24 V systems. They are produced within the Pierburg Competence Pool and benefit from synergies and many years of practical experience.
Heay Duty Actuators
Heavy duty actuators, in series production since 2012, are a robust solution for all flap control tasks. They are used at many locations in the power train in both hot and cold conditions, and are optimized for applications that require a linkage. Applications include the actuation of high-pressure exhaust gas recirculation valves or exhaust gas flaps, large flow rate fresh air throttle valves, and turbochargers applications such as variable geometry turbines and wastegates.
Compact Brushless (or Electrically Commutated) Actuators
The dimensions of the compact EC actuator are minimized. It fulfills the requirements of modern applications on both the “hot” and “cold” sides of the engine. The actuator is optimized for direct drive, but can also be used with a linkage. It is a robust solution for most scenarios including high or low-pressure exhaust gas recirculation, exhaust gas flaps, fresh air applications such as throttle valves, and turbocharger applications such as the VGT and wastegate. It can also be employed for the control of waste heat recovery systems with high flow rates.