Select Drop weight impact testing machine subcategory

DIT-Z Series for safety hemet drop test

Introduction  

Ø  Model: DIT501Z

Ø  Impact energy: 29.4J and 49J

Descriptions

Automatic drop weight impact testing machine type DIT152Z is used primarily for safety helmets’ properties determination of shock absorption and resistance to penetration.  

Shock absorption test

Ø  Choose the right headform according to wearing height ;

Ø  Adjust the helmet to working state according to the manual ;

Ø  Put the helmet on the headform;

Ø  Make sure that the touch between the brim and the headform is natural and in stability;

Ø  Adjust the drop hammer axis to make it coincided with the axis of the sensor;

Ø  Adjust the height of the drop hammer to 1000mm±5mm;

Ø  Do the conditional treatment under the sequential conditions of moisture, high temperature, low temperature, ultraviolet irradiation and record the impact force value, accurate to 1N. 

Penetration test

Ø  Choose the right headform according to the wearing height ;

Ø  Adjust the helmet to normal state according to the manual ;

Ø  Put the helmet on the headform as usual;

Ø  Make sure that the contact between the brim and the headform is natural and in stability;

Ø  Adjust the puncture cone axis so that it passes through the spot with the weakest structure at the circle of 100mm diameter on the top of the helmet;

Ø  Adjust the penetration tip to the point of contact of the crowns height 1000mm ± 5mm;

Ø  Do the conditional treatment under the sequential conditions of moisture, high temperature, low temperature, ultraviolet irradiation. Observe the movement of the energy display device and the destruction of the helmet and record the results of the penetration. 

Specifications

 This testing machine consists of the main frame, hammer components, driving system, release/clamp hammer device, specimen holder, security guards and control system.

Main frame

The backplane is made of a one-body steel plate of No. 45, which is connected by 4 columns with the top plate. There are 2 feed rods standing in the center to lead the hammer in order to guarantee the stability during the shock process.

The hammer components

The hammer assembly consists of the body and stickers. The body weighs 2.3kg. The shock striker weighs 2.7kg, and the penetration striker weighs 0.7kg.  The striker is connected to the body with a screw nail, which makes the change of stickers more convenient. The sticker is made of steel of 40Cr so it has good mechanical properties and good shock properties with small after-test damage and long lifetime.

Power system

Motor drive leads the chain sprocket to tow the chain to raise the hammer assembly. Imported high-precision optical encoder can detect the corresponding height of the sticker during the test and can also raise the sticker to the target height to make sure the accuracy of the impact energy.

Striker release/clamp device

With the self-locking device inside, the striker release/clamp device can lock itself automatically and immediately after the raise of the hammer. There is no decoupling under the gravity of the hammer. Otherwise it will lead to an accident. There is a proximity switch that can detect the place of the hook so that once the hammer is not clamped, the crosshead will not be raised. By adopting the electromagnet to release the hammer, the installation and operation is much easier and this device has a longer lifetime and good security.

Specimen holder

There are two kinds of sample holders separately used for shock absorption test and penetration test.

It is only needed to change the specimen holder for different tests, there is no need to replace the whole set of fixtures seat and headform for another test.

Security guards

   With a closed protective net, the safety guards can effectively prevent the fracture specimen from splashing, and can also prevent the operator from entering the interior of the machine. The safety net has a door limit switch, which will lock the testing machine in the case of the open of the protective door. In this case, any operation is invalid and mistakes will be avoided to guarantee the safety of the operator.

Control system

The testing machine is equipped with a set of automatic control system, which will realize the full-automatic process of the raise, shock and clamp of the hammer. It reduces the intensity of the labor and increases the work efficiency and operating safety.

PLC programmable logic controller from Siemens is introduced to design automatic control system of the testing machine. Equipped with a touch screen as the terminal operating machine, PLC’s reliability and high stability, strong disturbance resistance ability , promote the reliability and stability of the whole control system and avoid malfunction, greatly improving the security of operator .

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