Linear Motor Driven Valve

Quick Response – Acceleration & Deceleration

In order to control your molding process, your injection must follow its set parameter.  When you consider injection capability, an important factor is not max injection speed, but how quickly it reacts, from 0 to max and max to 0.


Figure: This chart shows a 0.016 sec. fill time molding application overlaying 20 shots. The injection reaction time is critical for repeating this process.

Red = Actual Speed
Brown = Actual Pressure

The injection response time is extremely important. It takes more time to reach a set speed if an injection response time is slower.


Injection Stroke to Reach Set Speed

Response Time (ms)Injection Stroke (mm)

1 ms = 0.001 sec

Sodick uses the linear motor driven servo valve to increase its injection response. With this valve, the injection gains high acceleration and deceleration performance, as well as control of speed and pressure.

  • Micro: Linear Direct Double Motor Valve – LP series
  • Standard: Linear Servo Valve – TR, GL, HSP series


Micro Servo Valve: Double Linear Motor


Standard Servo Valve: Single Linear Motor

MicroStandardElectric Machine
Drive SystemDouble Linear Motor DirectLinear Motor + Pilot ValveAC Servo + Pulley & Belt
AC Servo + Ball Screw Drive
Step Response (ms)2 ~ 315 ~ 2025 ~ 40
NC Loop Control (ms)50 (0.05ms)50 (0.05ms)62.5-100 (0.062 - 0.1ms)

Comparison of Step Response