Week 4:- Pin Unit Design Challenge
Aim:- Pin Unit Design.
Fundamental of pin unit design:- It is necessary to have two pins to locate a car panel. And here one pin must arrest 4 way (4 translation) and other must arrest 2 way ( i.e 2 rotational or a car panel)
1) Pin should enagage 3 to 5mm from car part entry surface.
2) All pin should be accomadated with 2 way adjustable shims irrespective of direction of arresting.
3) Round pins should be in case of 4 way arresting of car part if the hole 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 the hole is round.
6) Diamond pins should be used of 4 way arresting of car part if the hole is slotted.
The axis of the car panel hole and the axis of pins should be same. ( In general) The pin tolerence for a geo pin will be of closer tolerence. I.e 0-15mm & for re-spot pins is -0.28mm.
# Typical part of pin Design:-
Pin :- Pin a part which locates the car panel. A pin either be a make part or a standard part also.
Pin should have grinding surface on a shaft with fits on to which pin retainer will be fitted.
The mounting surface of the pin should be a fine machined surface.
The pin should have a step machine surface to lock the rotation, which matches with the pin retainer.
The mounting surface of the pin retainer to the block should be a machined surface.
The machined planes should be perpendicular to the axis of the pin shaft.
Pin must have a fastening provision like tapped the hole from the bottom or av grove from the side.
A pin must be burned (Heat treatment) & black oxide finished in general.
Pin Retainer:- A pin retainer is a part which holds the pin position, the pin retainer can either be a make part or a standard part also.
Pin retainer should have a hole with a fit, on to which the pill. Will be fixed.
The pin mounting surface of the pin retainer should have a step to lock the rotation of the pin.
The pin mounting surface of the pin retainer should have a step to lock the rotation of the pin.
The mounting surface of the pin retainer to the block should be a machioned surface.
The pin retainer will be fixed to a block or al block to riser with 2 dowel hole (pins) and at the least with one screw hole to maintain the tolerence.
Block/L Block:- These part are mainly used to accomadate the shimming diraction ad per fundamental in genaral. also in same cases for other design feasibility.
Shims/Spacer:-Shims & Spacer are some standard part in general, which are used for adjustment to locator (NC Block Pin retainer) for the pieces working of a unit with respect to car part in general to adust the design to manufacturing deviation.
Blade:- Blade is a part like a plate, which connects the part of a unit to a riser. In general the blade can be either a make part or a standard part.
Riser:- Riser is a part on which all the part of a unit are mounted, and is monted on the base plate of a tool, In general the riser can either be make part or a standard part.
Dowel Hole & Machined surface:- All makes part which tolerence should be designed with 2 dowel holes and at least of 1 to 6 threaded/ free holes ( Depend on size) and to be fine machined for the mounted surface with 3 to 5mm step machine.
#Retract Pin Unit:- A retract pin unit is a unit designed to locate the car panel using pins, but mounted on the retractable pneumatic cylinder.
Pin:-
Shims:-
L Block:-
Pneumatic single rod retractable cylinder.
Riser.
In this retractable pin unit their two type of cylinder:-
1) Single Rod Cylinder.
2) Double rod cylinder.
