Week 9 - Project - A pillar Design with Master Section

AIM:

Create  A pillar Design with Master Section

OBJECTIVE:

• Craetion of proper tooling direction following themastrer section to create the part that meet the requirements
• Draft analysis check to make sure that the class A surface is meeting the draft required along the tooling direction
• Creation of Dog house, Locators and ribs with meets the draft analysis on the side core axis for dog house

Master Section

• Master sections are the guides for design requirements that decide the component packaging after technical (Styling, Concept, or Class-A) surfaces. Creating this master section should need 5 to 6 years of experience.
• This helps you to decide the feasibility, clearance, packaging, and fixation strategy before working it on a 3D. We have a master section.

PROCEDURE:-

   1)CLASS A SURFACE CHECKING:-

           TOOLING AXIS:-In injection molding, the Class A surface is first analyzed to determine the axis or tooling direction that separates the molds. Tooling direction is critical for plastic product design because it determines mold direction.In this A pilar model the tooling axis is created using one of the method.The tooling axis is created using bisecting method and we will do the draft analysis of the class A with this tolling axis.

                         

 DRAFT ANALYSIS:-

• For molded or cast parts, the draft angle is the amount of taper perpendicular to the parting line. It is measurable in degrees. Because plastic shrinks and sticks on molding surfaces as it cools, we draft the walls of the plastic part so that it ejects or breaks free from the molding surfaces more easily and without dragging. To reduce the risk of damage to the parts and ensure ejection, a functional injection molding part must have drafts on both the cavity and core sides.

   

Importance of Draft in injection molding:-

• Reduces the possibility of part damage due to friction during the release.
• Reduces mold wear and tear.
• Ensures a uniform, smooth, unscratched finish.
• Ensures the integrity and uniformity of other surface finishes and textures.
• Reduces overall cooling time by reducing or eliminating the need for unusual ejection setups.

Steps followed for Draft Analysis:-

• The created part must be changed to the material mode in the display frame.
• Compass is enabled and placed in the direction of the Tooling Axis.
• The lock command is then used to fix the compass along the tooling axis.
• Colour codes are classified and Draft angle is applied.
• Running point analysis is used to display permissible draft angle. 

                      

   FEATURE TREE:-

                                                                                       

  2)CLASS B CREATION:-

• To create the class B surface, offset the class A surface inside as per our thickness requirement (here the thickness is 2.5mm, so I offset the class A to 2.5mm inside).
• Once the offset is created, we can observe some patches on the offset surface by taking the boundary for the offset surface, those patches are formed due to the fillets on the class A surface.
• We covered the patches by using the different surface commands (multi sections surface, fill, blend) in the Generative Shape Design workbench.

                  

                 

                 

                 

                 

                 

3)CLASS C CREATION:-

• To create the class C surface concerning the boundary of the class A surface, I used the sweep command. Initially, I extracted the boundary of the class A surface with tangent continuity, and I sweep the extracted boundary concerning the surface at 90deg (for draft angle) for 4mm to intersect properly with the class B surface.
• Once we sweep all the surface boundaries of class A, extrapolate the swept surfaces until both surfaces got intersected properly, and trim them to remove extended extrapolated surfaces to get a proper sweep boundary throughout the entire surface, including the centre hole of the bumper. 
• Now, join both class A and sweep boundary to get the complete class C surface. 
• Now Class A surface and Class C surface is joined.
• Now Class B surface is also trimmed with the obtained surface to get the closed surface.
• Boundary check is done to check for any open boundaries in the part. The closed surface then obtained moved to part design and close surface tool is used to obtain the part. 

               

                                                          

      FINAL TRIM:- join of A and C surface is trimmed with B surface so that we can get the close surface.

            

            

   CLOSE SURFACE:-Using close surface command in part workbench the the surface geometry is filled.

            

 DRAFT ANALYSIS:-

            

4)B SIDE FEATURE CREATION (DOG HOUSE):-

           

                                               

  The dog house is an engineering feature used in the plastic trim design. Dog houses are used as a supporting feature. Sometimes other engineering features like snaps; locators, etc. are mounded on them to increase their strength.The doghouse is created by following the design rules.The nominal wall thickness guide range is from 0.75 mm to 3 mm for reinforced materials and 0.5 mm to 5 mm for unreinforced materials.Related Courses

WALL THICKNESS (W) = 0.70 (NOMINAL THICKNESS OF PLASTIC MATERIAL)

This process is usually done by Thicken surface command.The fillets and the draft are given as per the design rules.An important thing while designing a doghouse is to maintain 40% less thickness than the wall thickness (T) at the area of the intersection to avoid sink marks. So, a C shape is formed at the intersection.This can be made using the split command to remove the solid at the intersection.

   The Dog house or B side features which will not comein the main core and cavity tooling axis this are created using side core with different tooling axis.

SIDE CORE:-

   To create dog house side core is used because its not its side feature and can't be manufactured by the main core and cavity only.Whentheir are inner and outer holes or undercuts on th eplastic part that are different from the mold opening direction.Plastic parts cannot be enjection.The mold side hole or the undercut part must be made into a movable core.And the movable core is taken out before the plastic part is pushed out.Then take out the plastic parts.The mechanism for accomplishing these actions is called a side core pulling mechanism.

                                              

 CREATING DOG HOUSE:-

              

 SIDE CORE TOOLING AXIS:-

             

             

              

              

              

              

              

             

            

           

          

          

         

         

         

         

         

         

         

        

        

        

        

        

        

        

        

        

        

FINAL RESULT:-

        

        

DRAFT ANALYSIS OF FINAL OBJECT:-

         The draft analysis is done with two different axis.A main axis for the A Pillar solid it should have 3 degree draft and for Dog House the axis will be side core tooling axis it should have 0.5 degree draft.

       

      

      

      

      

CONCLUSION:-

• Created Tooling axis
• Created Class B and Class C surface from provided Class A surface.
• Created solid part out of surface modelling.
• Created engineering features from the master section provided.
• Draft analysis of Class A surface and final part is also done.