How It Works: For Stack Height Control

In a hydraulic or pneumatic servo system, the MICROTORK valve provides precise and accurate continuous positioning. An extremely low amount of actuation torque is required to rotate the valve stem. This extremely low positioning torque, which completes the feed back loop in the system is a key feature of the MICROTORK design.

This sample application shows a stack height control system maintaining constant height of the stack as sheets or plates are removed or added. This animation serves to demonstrate the working nature of the MICROTORK design.

When a sheet is removed from the stack the feed back arm drops and rotates the MICROTORK valve clockwise. This slight rotation allows high pressure hydraulic fluid to flow to the bottom of the hydraulic cylinder. Simultaneously it also allows fluid to exit the top of the cylinder and flow to the reservoir tank. This action causes the hydraulic cylinder to rise up placing the top sheet to its original set point. If a sheet is added to the stack the valve arm will rotate counter clockwise and the cylinder will move downwards.

  • Relief
    Valve
    Hydraulic Tank
    Hydraulic Pump
    Hydraulic
    Cylinder
    Stationary
    Table
    Self-
    Adjusting
    Platform
    Control Arm
    Servo
    Valve
    A
    Port Closed: No
    Flow to or from
    Cylinder
    B
    Port Closed: No
    Flow to or from
    Cylinder
    T
    Return to Tank
    P
    Inlet to Valve
    When the valve is in the "NULL" position the product is held at the same level as the platform. No flow of fluid is going to the cylinder and no motion is taking place. Inlet and outlet lines to the cylinder are shown in grey.
  • Relief
    Valve
    Hydraulic Tank
    Hydraulic Pump
    Hydraulic
    Cylinder
    Stationary
    Table
    Self-
    Adjusting
    Platform
    Control Arm
    Servo
    Valve
    A
    Port Opens:
    Flow to Cylinder
    B
    Port Opens: Flow
    allowed from
    Cylinder
    T
    Return to Tank
    P
    Inlet to Valve
    When the product is removed the control arm drops rotating the valve stem out of the "NULL" position. This angular movement of the valve stem allows high pressure fluid to flow through the valve to the bottom side of the cylinder and simultaneously allows fluid to exit the top of the cylinder through the valve. Flow inlet to cylinder is shown in green and fluid return is shown in red.
  • Relief
    Valve
    Hydraulic Tank
    Hydraulic Pump
    Hydraulic
    Cylinder
    Stationary
    Table
    Self-
    Adjusting
    Platform
    Control Arm
    Servo
    Valve
    A
    B
    T
    Return to Tank
    P
    Inlet to Valve
    Servo Control Valve accurately maintains proper stack height with table
  • How It Works: For Coil Winding Device

    The 3D model above shows a typical example of a coil feeding system. For this application it is required that the sheet metal be fed in a parallel fashion. As the coil winds or unwinds and becomes larger or smaller in diameter the guide level must therefore change to maintain the parallel state. For this application we place guide arm of the MICROTORK valve directly on the sheet stock. Any change in angular orientation will immediately be detected by the valve and compensated for with the cylinder.

    How It Works: For Coil Feeding Device

    The 3D model demonstrates a coil feeding device for feeding sheet stock that will eventually be used for a punch press operation. The punch press is equipped with a pulling mechanism that automatically pulls the sheet stock as needed. However, the correct amount of tension is critical for the automatic feed mechanism to function properly and not tangle the sheet stock. In this application the control arm of the MICROTORK valve rests directly in the sheet stock as shown to maintain the exact amount of slack in the coil. If the slack level starts to change, the hydraulic output of the MICROTORK valve will alter the speed of the unwinding wheel accordingly by controlling a brake system or hydraulic motor.

    How It Works: For Web Guiding

    Web, belt or edge guiding is a very common application of the MICROTORK valve. As is always the case in running large flat belts, they have a tendency to drift in one direction or the other depending on the alignment of the rollers. By having the control arm of the MICROTORK valve running along the edge of the belt and the output of the valve controlling the extension length of the piston, automatic alignment adjustment takes place.