Week 4:- Pin Unit Design Challenge
DESIGN OF FIX PIN AND RETRACTABLE PIN UNIT
The fix pin and the retractable pin units are hole constraining fixture for car panels.
FIXED PIN UNIT
Fixed pin unit is a unit designed to locate the car panel using pins.
The parts of fixed pin are:
- Pin
- Pin retainer
- Shim/Spacer
- Block
- Blade or Adapter plate
- Riser
Fundametals of pin unit design
- it is necessary to have 2 pins to locate a car panel & here one pin must arrest 4 way(4 translational) & other must arrest 2 way(i.e. 2 rotational) of a car panel.
- The axis of the car panel hole & the axis of the pin should be same (in general)
- The pin tolerance for a geo pin will be of closer tolerance i.e. -0.15mm & for re-spot pin is -0.28mm
1)Pin should engage 3 to 5 mm from car panel entry surface.
2) All pins should be accomodated with 2 way adjustable shims irrespective of direction of arresting.
3)Round pins should be used in case of 4 way arresting of car part if the hole is round.
4) Round pins can be used for 2 way arresting of car part only if the hole is slot.
5)Diamond pins should be used in case of 2 way arresting of car part if hole is round
6)Diamond pins should be used in case of 4 way arresting of car part if hole is slotted.
There are 2 types of pin units
1) Fixed pin unit : In this type of unit the pin is fixed by means of pin retainer & riser.
2) Retractable pin unit: In this type of unit there is the provision of moving of pin in up-down direction.
PIN
Pin is the part which locates the car panel.
Two type of pins are there:
Round Pin:
Diamond Pin:
