• Technical information-Structure & Principle

    • Shock Absorbers
    • Hydraulic Buffer
    • Hydro Check
    • Gas Spring

    As mechanical operating parts of industrial machineries, such as automated assembly machines, various conveyors,
    and safety devices for machine tools, are becoming faster, they generate shock,
    vibration and noise that affect the performance of overall machineries and cause safety issues in working environments.
    Shock Absorber is developed to solve these problems.

    KOBA Shock Absorber provides controlled, predictable deceleration by absorbing the shock and vibration from production facilities.
    It protects the facilities from destruction, frequent collisions and wearing due to vibration.
    KOBA Shock Absorber is possible to prevent aging of production facilities.
    Save cost by shortening operating hours and improving productivity, reduce noise pollution and increase production.
    KOBA Shock Absorber comes in various types and capacities to satisfy your needs.

    Rubber & Spring When decelerating an object in motion using rubber or spring,
    the compression strength is not consistent and resistance
    increases as it compresses to generate a larger repulsive force.
    Thus the object is shocked again by these devices.
    Even if shock is absorbed at first,
    the repulsive force is delivered back to the object.
    These devices have undesirable recoil effect.
    Hydraulic &
    When using hydraulic cylinders,
    dashpot and Deceleration valve with single orifice hole,
    a huge resistance is generated at the start of the stroke.
    In the case of using pneumatic cylinders ,
    the resistance force is increased from first stage and
    it reach the maximum level at the end.
    Shock Absorbers
    In order to minimize shock that is generated
    when stopping the moving loads,
    it uses several orifice to maintain the resistance
    consistent throughout all ranges of
    stroke and stop the moving loads smoothly.
    All models of KOBA Hydraulic Shock Absorber use
    multiple orifice structure for smooth stopping of moving loads.

    1. Shock Absorber is consists of Body, Bumper Head, Piston Rod, Adjustment Dial and Lock Nut.
    2. Body consists of several screw threads to increase surface area and effectively discharge heat by
    absorbing shock at collision. Screws can also be used for easy fixing.
    3. Bumper Head reduces noise and serves as stopper.
    4. Piston Rod gradually reduces the speed of object and stops it smoothly.
    5. Adjustment Dial can adjust Damping Energy according to the speed of collision and can be controlled according to the load and collision.
    6. Lock Nut can accurately and stably control the position when used with the screws on body.

    Shock Absorber includes Piston, Check Valve, Accumulator, Inner Tube, and Multiple Orifice.
    Return Coil Spring, oil, and, etc. As Piston Rod enters Inner Tube according to stroke,
    Check Valve closes and Oil is inserted into Inner Tube through Orifice. In this process,
    Oil is increased as much as volume of Rod and saved in Accumulator.
    In return, Check valve opens and compressed Coil Spring quickly returns Piston rod to its original position.

    When Moving object collide onto Piston rod, the collision is delivered to the oil in Inner Tube through Piston.
    In result, the oil inside is flown through orifice in Inner Tube and generates pressure in Inner Tube.
    During this process, the shock energy is transferred to thermal energy and it is dissipated outside.

    Single Orifice

    Single Orifice Type consists of Dashpot structure, which uses the gap between piston and Cylinder Tube or creates a Hole,
    Single Tube structure with Orifice on Piston, and Single Orifice structure (adjustable) on Dual Tube Type.
    The resistance of each structure is shown below.
    When Piston moves inside Cylinder Tube, a large pressure is generated inside Inner Tube at first.
    The area of orifice remains consistent throughout all ranges of stoke and the resistance increases instantly
    right after collision and decreases at the end of stroke as speed decreases with the progress of stroke.

    Multiple Orifices

    ■ Adjustable type

    The area of Orifice at collision is larger than that of Single Orifice Type and the resistance is
    maintained consistent throughout all range of Stoke to stop the colliding object smoothly.
    It is also possible to customize the properties of resistance according to operation condition by using adjustment dial.

    ■ Self adjusting type (Non adjustable type)

    The principle of operation is same as Adjustable type and is designed to customize the properties of resistance according to operation condition.
    The below picture is shown the characteristic of damping
    (A1 high velocity / low propelling force B1 low velocity / high propelling force)