Week 11 - Final project

DEVELOPMENT OF LOWER DOOR TRIM PANEL

The aim of the project is to develop the solid body parts of lower door trim panel from the given class A surfaces by creating tooling axis, B and C surface and by adding engineering features like dog house, heat stakes, push pins, ribs, locators, etc with reference to the master section then do the draft analysis for the same and assemble all them together to get the final product.

Steps followed to create the solid body and to do the draft analysis

A surface

• The class A surface is checked for the connectivity of the surface and ensure it is completely joined and ensure there will be no gap between the surfaces.
• Connectivity of the surface can be done by two ways by join method and by boundary method.
• If it is not join together make it with a minimum tolerance of 0.001 to 0.003 and check for connectivity of the surface.
• Split the surfaces into multiple profiles then Identify the surface where it is not possible to create a tooling axis by following the minimum draft angle and check on which direction is best fit for tooling axis and then define the tooling axis and draft direction.
• Here for defining the tooling axis first we have created a point at middle of the base surface and create an axis with respect to that point then define the tooling axis using the intersect method by creating a bisecting line.
• Then do a draft analysis on the class A surface and identify the draft angle then give the nominal value for the draft.

INPUT RECEIVED

Tooling axis creation

• The direction in which the mould open and closes is called the tooling axis direction.
• Check the connectivity of the surface and ensure there will be no gap between the surfaces and then define the tooling axis.
• While creating a tooling axis please ensure to give the tooling axis on a flat length surface or the surface which have a hole on it.
• Create a point on the middle of the base surface by using point on the surface command then create a intersection for the surface and extract the reference lines which will be helpful for creating the dummy tooling axis using the intersect method by creating a bisecting line..
• Use the line command and draw the lines which is aligned with the extracted lines and extended it to the required length.
• Bisecting method
• Identify on which plane we have to do more operations and create the plane or axis on the component area define it on the dummy tooling axis direction.
• Intersect the class A surface with that plane then we will get a intersection sketch. Look for the profile (inclined line) which will create a problem and extract it then extending it by using line command.
• Then create a bisecting lines with reference to the lines we have extended and this will be our main tooling axis.
• In this case we have created tooling axis along with reference to the plane direction and the master sections.

TOOLING AXIS CREATION BY BISECTING METHOD FOR DOOR ARM REST

Draft analysis

• Draft allows for the component to release from the mould, most parts or applications require a minimum of 0.5 to 1 degree draft angle and 3 degree draft angle is widely used as per the norm.
• Change the material mode to customize mode before moving to the draft analysis.
• Insert –analysis-feature draft analysis
• Defining the draft direction Select draft analysis from the tool bar and click on the compass symbol and pull the compass from the right side top corner of the workbench and place it on the component where want to do the draft analysis. ‘W’ of the compass and tooling axis should be aligned on the same line.
• Once the compass is aligned with the tooling axis click on the lock symbol and drag on the surface we will get a wrong mark then select that point a table will appear it shows the draft value on the table we can adjust the draft value and analysis it for all the edges and surfaces.
• By clicking the on the surface and using the flipping tool we can assign the Flipping direction, the color of the surface change as per the flipping direction .
• Analysis under running point and move the mouse on the surface and it will show the details of the surface deg direct at each and every point of the surface.

DRAFT ANALYSIS FOR DOOR LOWER SUBSTRATE

B surface

• In the case of Class A the surface below is called core and the surface above is called cavity.
• Class A is an aesthetics surface and class B is an engineering surface.
• B surface should be inside the class A surface.
• As the class A is more complex and having multiple geometries, in this case we can directly offset the class A surface to 2.5mm thus we can obtain B surface.
• B surface is then checked for the connectivity of the surface but it shows some patches on B surface. We have to close it by extracting the required boundaries with reference to the surface and spline the uncovered area then close it by using the multi section surface, sweep and extrude method.
• All the closed patches is then then joined together by using join command and checked for the connectivity of the surface.

B SURFACE OF DOOR ARM REST

C surface

• C surface has been created from the boundary lines of class A surface and by extracting the supporting surfaces then sweep the boundary lines with reference to the extracted surfaces or tooling axis with nominal draft angle.
• Check for any flanges is given in the master section if so, first create the flanges the reference to the master section and the B surface.
• In order to get the C surface first we have to create a boundary lines of class A surface or by using multiple extrapolated command and check for the continuity of it.
• Create a sweep with reference to the curve and the reference surface with a 90 degree angle and give the inside direction Check for the continuity of the surfaces if there is any gap go for extrapolated and trim all together now we will get the class C surface.

C SURFACE OF UPPER MAP POCKET

JOINING THE CLASS A WITH C SURFACE AND THEN TRIM IT WITH B SURFACE

• All the C surfaces are joined with class A surface by join command and then trimmed to B surface check it for connectivity of the surfaces we will get the final component again check whether the final body is closed by using boundary command.
• Closed solid body is created by using the close surface on part workbench by selecting the final Trimmed component and do the draft analysis for the same.
• Follow the same steps for developing all the other parts of the door trim panel..

CLOSED BODY OF LOWER MAP POCKET

SOLID BODY OF DOOR LOWER SUBSTRATE

ADDING ENGINEERING FEATURES

• During the period of vehicle concept design the evaluation of master section performance mostly depends on reference vehicle data.
• Master section helps to decide the feasibility, clearance, packaging, fixation strategy of a component.
• The first step is to analyze and under stand the master section and identify what are the features need to be added to the main body.
• Follow all the dimensions in the master section to create the sketch and check it with the nominal guidelines of the engineering features.
• Create a plane with reference to the master section and draw the required profile by using positioned sketch by following all the guidelines then extrude and make it into a solid body.
• The draft analysis for the engineering features can be done by using the main tooling axis and the inner portion by adding a side core axis with a minimum draft angle of 0.5 degree.
• The solid body should be match with the master section and follow all the required draft with the tooling axis and side core axis then only it will can be valid for production.

FLANGES

HEAT STAKES

• Thermal staking is an assembly method that uses the controlled melting and reforming of a plastic stud or boss to capture or lock another plastic or metal component of an assembly in place.
• In simple Joining the plastic material to any other parts by controlled heating.
• Heat stakes is used to arrest the degree of freedom of the locators by 3-2-1 principle in automotive tooling design.

Guidelines for creating the heat stakes

• Min 50mm gap between heat stakes
• Max fillet radius: 0.25mm
• Max clearance with the counter clearance should be 0.5mm.
• Min draft-0.5mm

DOG HOUSE

Dog house is a feature helps to avoid sink marks, adjusting the length and perpendicular to the axis.

Dog house can be design by extracting the base surface and create a positioned sketch then extrude or sweep it to the required dimensions and following the design standards.

Then provide the draft, fillet and finally assemble it with the main body.

Design rules to follow while designing the dog house

• Dog house wall thickness at intersection of part wall (C) should be 40% or less than main wall stock (T).
• Height of (B) should be in between 3.0 to 6.0mm.
• Min draft: 1.5mm * to the die draw
• Width of dog house 12mm minimum.

CONCLUSION

Thus we have assembled all the plastic parts of lower door trim panel with engineering features and do the draft analysis by following all the industrial standards used in tier-1 company or OEM.