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HIAMS in the U.S.A.

Variable Valve Event & Lift (VEL)


  • Fuel consumption improvements & Exhaust emission reduction
    VEL contributes to not only fuel economy and low emission, but also driving pleasure, which means improvement in response and torque at low and middle rpm, maximum power at high rpm.
  • Operated to high lift during Engine is stopping
    VEL can change both valve lift and event (duration) from lowest lift state below 1mm for fuel economy to highest lift state over 12mm which means the valve lift of racing engine.
  • High expansion ratio & Low friction
    VEL can be installed in conventional cylinder head without camshaft axis position large change from conventional axis position. High rpm tolerance and low driving friction can be obtained owing to multi-link valve train mechanism, and quick changing response and low energy consumption can be got by electric powered ball screw actuator.

System construction of VEL


VEL operating principle


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VTC (Valve Timing Control system)


VTC system is the combination of VTC and Solenoid Valve (SOL/V). VTC continuously varies valve timing with engine speed, temperature, and load of engine. Valve timing has been fixed by opposing requests of various engine operations. However, VTC achieves continuous and optimum valve timing in all gasoline engine operation.

Engine Control Unit(ECU) computes the required information of engine speed, temperature, and accelerator opening, and sends the control signal to Solenoid Valve. Oil pressure controlled by Solenoid Valve continuously controls VTC.

Features & Benefits

Optimum valve timing in all engine operation improves Nitrogen Oxide(NOx) and Hydrocarbon(HC) in exhaust gas and greatly improves fuel economy, engine power and engine performance.

  • VTC
    Light weight compared with Aluminum VTC because of thinner PM design
    Standard variable timing
  • SOL/V
    Smallest and lightest because of improvement of valve structure and solenoid design.
  • Prevent pre-Ignition by decompression during engine start-up.
  • Wide shifting angle and high torque capacity

Image:ecss VTCiElectric Control Spiral Structure Valve Timing Controlj

Image:ecss VTCiElectric Control Spiral Structure Valve Timing Controlj