Week 4:- Pin Unit Design Challenge

PROJECT : Pin unit design for the given car panel.

AIM :

1. Design 2 Different types of Fixed Pin Unit with Different Pins, Riser, Blade, and Block.

2. Design 2 Different types of Retractable Pin Unit with Different Pins, Riser, Blade, Cylinder, and Block.

INTRODUCTION :

- If we talk about BIW fixture design , we have a assembly which includes many parts to become a fixture.

  BIW Fixture Design :

  BIW FIXTURE BASIC PARTS TERMINOLOGY

  - Some basic manufacturing parts, which are commonly used in the BIW fixture design. Very commonly used parts are Mylar, Pin, Blade, L Block, Pin Block, Riser, Weldment, etc.

  - In the given project we will start designing the pin unit .

PIN:

Pins are used to locking the rotational movement of the panel. Generally there two types of Pins, one is Round Pin and another one is a Diamond pin. We use two and three-directional shimming for pins as per the angle of the pin w.r.t. the carline. In some cases, we use a collared pin, when the pin is supposed to support the panel as well. For this kind of pin, we provide 3 way shimming irrespective of pin angle to the carline. 

 

- Generally there are two types of pin unit :

 

  1. Fixed pin unit.

 

     - Fixed pin unit is a unit designed to locate the car panel using pins. Pin , pin retainer , shims , blocks , blade , riser are the part of fixed pin units.

 

        

 

    2. Retractable pin unit.

 

              

 

 

LOCATING PINS AND HOW THEY ARE USED :

 

Typically, locating pins are used for controlled, fine tolerance positioning of a work piece. For example, a pallet
that is moved along one axis, where the drive mechanism is not accurate and stable enough to place it in a position
sufficiently accurate to execute a particular process, the use of locating pins may be the best solution.
Usually two locating pins are enough to properly locate the work piece on one plane.
There are dozens of styles of locating pins that can be utilized in a design. We will explain the structure and show
an example of how each style can be applied.
One of the most common pins is a stepped pin with either small or large head.

 

Diamond Shaped Pin 

The Diamond Shape is a critical feature that helps with machining inaccuracies and smoother locating operation.
When two round head pins are installed onto one plate, the distance between two mounting holes must be extremely
precise and even then, the work piece will not be placed on the base as easily as it would with the use of a diamond
shape pin.

 

 

There are other ways of utilizing diamond locating pins. This is one example, where you need to perfectly align the
center of the part, but the angular orientation is not critical.

 

 

 

FUNDAMENTAL OF PIN UNIT :

 

- It is necessary to have two pins to locate a car panel.

 

- One pin must arrest 4 way (4 Translational motion).

 

- One pin must arrest 2 way (2 Rotational motion).

 

  

 

 

DESIGNING PIN UNIT :

 

 

      

 

 

 

- So we have given with a car panel assembly cat part also we have step file for the same so that we can use it in any version of catia , save it as cat product.

 

- As you can see in above images we have rear car panel which is located at rear end of the use to store the spare wheel & other components.

 

- For this panel we have to design 2 types of fixed pin unit & 2 types of retractable pin unit.

 

- A base plate also given for the referance.

 

- Create a new cat product which will our main assembly of the fixture , in that we will first add the car panel which we save earlier.

 

- Now add a new product inside the main assembly which we will name fixed pin unit 1.

 

 

DESIGNING FIXED PIN UNIT 1.

 

- As we created product file we will add parts into it Pin , Pin retainer etc.

 

- All sketchs must be iso contrained.

 

 

PIN DESIGN :

 

       

 

 

PIN RETAINER :

 

        

 

 

L BLOCK :

 

     

 

L TYPE RISER :

 

      

 

RIB TO PROVIDE STRENGTH TO THE RISER :

 

 

 

SHIM PACK :

 

 

ASSEMBLY FIXED PIN UNIT DESIGN :

 

          

 

         

 

 

 

 

DESIGNING FIXED PIN UNIT 2.

 

DIAMOND PIN :

 

    

 

 

PIN RETAINER :

 

    

 

 

BLOCK :

 

     

 

 

I TYPE RISE :

 

      

 

 

ASSEMBLY :

 

        

 

        

 

 

 

DESIGNING THE RETRACTABLE PIN UNIT :

 

RETRACTABLE PIN UNIT 1 :

 

 

PIN :

 

       

 

 

CYLINDER :

 

    

 

CYLINDER SZK_40_1_BR3_A12_T12_TUENKERS.1 SPECIFICATIONS :

 

    

 

 

BLOCK :

 

        

 

 

L TYPE RISER :

 

       

 

 

SPACER :

 

     

 

 

ASSEMBLY :

 

     

 

 

 

 

RETRACTABLE PIN UNIT 2 :

 

PIN :

 

      

 

 

PIN RETAINER :

 

     

 

BLOCK :

 

     

 

 

CYLINDER :

 

 

CYLINDER SZKD_63_5_BR3_40_A13_T12_TUENKERS.1 SPECIFICATIONS :

 

  

 

 

ASSEMBLY :

 

     

 

 

MAINTAINING PROPER TREE STRUCTURE THROUGHOUT THE DESIGN PRACTISE :

 

       

 

 

 

CONCLUSION :

 

- I conclude here designed two types of fixed pin unit & two types of retractable pin unit following the design methology.