DAF Project

DAF Project

1. Old ZF Air Cylinder

   • Function and principal of the cylinder
     • Advantage
       • 1. To get a small distance change, Use the bearing to control the small distance. 2. Symmetric, in XYZ axis. Weight symmetric. 3. Consider the bolt will be inserted through the cylinder. Seal good. 4. Certain distance between locked and unlocked situations. 5. When the air inputs, it’s unlocked. The shaft goes inward. Which means you can’t use the compress of the spring to make the shaft inwards.
     • Disadvantage
       • Update and rebuild the air cylinder
         • Requirements to start
           • 1. Fit into current column; 2. Air operated; 3. Meet locking load. We don't want the plate slip when it's locked; 4. Constant air inputs to unlock.
         • Tips to build the model. 1. Simplify the model: decrease the number of parts. 2. Think about unlock the cylinder in the other side; 3. Always think about the area of the surface to push the spring.
           • Pressure, force, spring constant K calculation
             • Decide the dimensions of each part
               • Build the CAD model
                 • Evaluate all the requirements. Ex. 1. If the pressure is enough to push spring; 2. If the spring can be used.
                   • Prototype
       • 1. Hard to assemble. Washers need to be inserted to the tight slot. 2. Manufacture cost of the piston will be relatively high. 3. Customized bearing is required. The balls are inconvenient to keep.

2. Technical Requirements Specification --- Steering Column

   • Requirements for locking mechanism
     • Benchmark for pneumatic actuator
       • Gear actuator
       • Diaphragm actuator
     • 1. Pneumatic actuator; 2. Unlocked if the air pressure is ≥ 4.5 bar (65 lb/in^2) and ≤ 12 bar (174 lb/in^2).
       • Friction requirements, clamping load
   • Build the steering column