Due to the problems of engine vibration, installation accuracy thermal expansion contraction, the relative position of engine air filter is relatively fixed, so they cannot be rigidly connected with rigid pipes, but need to use soft sections to form a transition connection.

  The requirements of the air inlet hose are:

  The resistance of expansion bending is small to ensure air tightness, follow-up service life. At the same time, the radial deformation is required to be small no deformation, that is to say, it can absorb flat. In order to ensure the smooth flow of gas, the bellows has this function, it is used in many similar occasions. However, the intake pipe does increase the contact area with dust, also increase the expansion strength of the pipe

  The material process requirements are:

  The material must ensure good air tightness, i.e. moderate rigidity softness, good durability weather resistance as well as certain heat resistance.

  The manufacturing process must be economic first. At the same time, it must be ensured that the inner outer surfaces are smooth; secondly, the plate elbow must be a "dead angle" to ensure that no fatigue crack will occur due to stress concentration. This is very important. The air intake is smooth. Other process requirements are the same as general pipe fittings.