The Finite Element Analysis Applied To Design The Hammer Of Air Impact Wrench

Air impact wrench also call wind impact wrench.The air impact wrench with hammeruses a rotary impact mechanism to enlarge several dozen times the torque from outputshaft of air motor.The rotary impact mechanism is the key component in air impactwrench.The hammer is the key part in impact mechanism.The quality of hammer caninfluence the output torque and life of air impact wrench.The air tool industry whendesigning hammer usually references some professional foreign benchmark samples todesign. Because the shape of hammer is complicate, at the same time because ofmanufacture tolerence,the benchmark sample has been used and other a couple reason.There is big design difference between initial hammer deisgn and benchmark’s hammerdesign.The initial hammer usually can cause lower output. The initial hammer can fail easybecause of big stress of some position in hammer.on the other hand the power of air impact wrench is the high-pressure air.Thehigh-pressure air drives air motor, air motor drives impact mechanism to output torque.Butbecause the air can be compressed, the air pressure is very difficult to keep invariable.After impact mechanism impact, the speed of air motor will reduce a lot.The load that airmotort is exerted to the impact mechanism is unstable.If we use the traditional design method, make prototype samples to prove, is it designto improve, make prototype samples to prove again, improve again, prove again. We needspend lots of time and cost to do lots of test. In this case we use dynamice torqueequipment to test dynamic output torque, and use finite element analysis method to designhammer. We exert invariable simulation speed load to impact mechanism in CAE soft ware.To make CAE simulation mechanics load equal to the result that actual mechanics.Baseon the initial design of hammer, we use finite element analysis method to optimize todesign internal shape of hammer have reduced the stress of hammer. Through theoptimization design of hammer’s outline design, have increased weight properly, increase the output torque of air impact wrench.After the optimization design to hammer,the finaldesign hammer can meet requirement, has shortenned development period greatly, havereduced the cost of researching and developing.