Variable Valve Timing (VVT) process is used in internal combustion engines to vary the valve timings. It is the next step forward in appropriate utilization of an engine, post development of the multi-valve technology. VVT aides in improving performance of the engine and also reduces emissions, apart from decreasing fuel consumption. Thus, it helps in increasing the power and torque also. VVT process varies the timing of opening and closing of the inlet valve and exhaust valve of an engine. Overlapping of the two events, namely opening the inlet valve and closing of the exhaust valve is optimized by the VVT process which leads to the difference in power generated by the engine.
At faster speed, VVT ensures maximum overlapping while at moderate or slow speed it tunes the overlapping of opening the inlet valve and closing of the exhaust valve as per the requirement. VVT aides in reducing fuel consumption by optimizing exhaust gas recirculation (EGR). VVT can ensure that some of the exhaust gas is re-circulated in the engine by delaying the opening of the exhaust valve while the fuel-air mix inlet valve is kept open. Thus the recirculation leads to less consumption of the fuel-air mixture which ultimately leads to lesser consumption of fuel.
The global market demand for VVT is constantly increasing primarily due to the increasing demand for fuel economy of engines, combined with power and torque. Various regulations related to emissions have also been positively impacting the demand for better VVT technology since it plays a crucial role in reducing emissions. Various law enforcements are requiring auto makers to ensure that the lowest possible emissions are created from their engines, thus leading to advancements in the VVT technology. Additionally, the global increment in automobile sales has also been boosting the growth of the VVT market.
However, competing technologies such as start-stop system can pose threat to the VVT technology. Also, difficulty in fault recognition of VVT and high cost of replacement has been hindering the growth of this market. Additionally, after-market supply of VVT systems is still quite limited. Several automobile manufacturers are engaging in serious research and development to fully computerize the process for varying the valve timing infinite times and also for better engine output. Also, position and angles of cam shaft are being experimented with regularly for bettering the system.
By technology, the global VVT market can be segmented into cam-changing VVT, cam-phasing VVT, cam changing & cam phasing VVT and others. The market can be segmented by fuel type into diesel VVT system and gasoline VVT system. Furthermore, VVT market can be geographically segmented into North America, Europe, Asia-Pacific (APAC) and rest of the world (ROW).
Some of the key companies leading the VVT market are Aisin Seiki Co. Ltd. (Japan), Continental AG (Germany), Denso Corporation (Japan), Hilite International, Inc. (U.S.), Hitachi Automotive Systems (Japan.), Johnson Controls, Inc. (U.S.), Mitsubishi Electric Corporation (Japan), Robert Bosch GmbH (Germany), Schaeffler AG (Germany) and Valeo SA (France) among others.