Design of backdoor

BACKDOOR

                      A Door is the rear part of the car which access the luggage in or out. It also encloses the stepney and other tools, etc.

                       In the most of the cars, these back doors are operated with the help of gas stay which in turn reduces the effort required to lift the door. Some luxury cars have powered backdoor which in turn is driven by an electric motor.

                      The back door has the space for mounting the tail lamp and braking light

TYPES OF BACK DOOR

• TOP MOUNTED BACKDOOR
• SIDE MOUNTED BACKDOOR
• BOTTOM MOUNTED BACKDOOR

PARTS OF BACKDOOR

Some of the major parts of the backdoor are listed below

• Outer panel
• Inner panel
• Hinge and its reinforcement
• Gas stays and its reinforcement
• Wiper motor and its reinforcement
• Latch and its reinforcement

 

PROCESS USED IN SHEETMETAL FOR MAKING A BACKDOOR

• DEEP DRAWING
• BLANKING
• EMBOSSING
• HEMMING
• TRIMMING

DEEP DRAWING

                     This deep drawn process is extremely popular amongst manufacturing companies for its high precision capabilities at large volumes

                         Starting with a metal blank, the disc of metal cut from a larger sheet is pushed into a cavity around a die, which begins the deep drawn process of drawing the blank into the desired shape.

                        This is completed in gradual steps to ensure an even distribution of the metal across the final shape, which is important for preserving the integrity and strength of the finalised deep-drawn component.

BLANKING

                           Blanking is a metal production process, during which a metal workpiece is removed from the primary metal strip or sheet when it is punched. The material that is removed is the new metal workpiece or blank.

EMBOSSING

                     The metal sheet embossing operation is commonly accomplished with a combination of heat and pressure on the sheet metal, depending on what type of embossing is required.

                      Metal sheet is drawn through the male and female roller dies, producing a pattern or design on the metal sheet.

                       Depending on the roller dies used, different patterns can be produced on the metal sheet. The pressure and a combination of heat actually "irons" while raising the level of the image higher than the substrate to make it smooth

HEMMING

                         Hemming in sheet metal operations refers to the bending of the sheetmetal edge onto itself. It is very similar to edge stitching in clothes. Similar to how an edge stitch strengthens the edge and makes it more durable, a hem imparts strength to the metal edge and improves its appearance. The edge of one part may also be folded onto another part to create a joint.

TRIMMING

Trimming is the removal of excess metal from a stamped part to allow the part to reach the finished stage or to prepare it for subsequent operations.

DESIGN METHODOLOGIES TO CREATE A BACKDOOR

GIVEN STYLING SURFACE

For the above given styling surface has not properly sew to a single sheet, it has contained some gaps and damages in the sheet, so that the sheet has repaired and convert in to the single sheet.

The converted sheet taken as a reference to create a backdoor outer panel

BACKDOOR OUTER PANEL

                         In that edges of the reference surface have been offset to the distance of 10 mm

                         Offset curve taken as a reference to trim the balance sheet

                         The trim sheet surface has offset at a distance of 2.65mm

                         The edges of the offset surface have been extended using the law extension

                         The extend surface has been sew together

                          Using of face blend-Three face, linked face, offset face, law extension

                          The relief have been given to the corner of the sheet metal bending area

                           To make a even corner for mirror the geomentry to extended the component and also trim together

                            To make a mirror of the component taken a plane as a reference using a mirror geometry

                           To sew the two different sheet metal to single sheet

BACK DOOR OUTER PANEL LOWER

For same as the above operation the outer panel lower has been created

BACKDOOR INNER PANEL

                              First create a working surface take as a reference and has been offset at a distance of 1.7 mm backdoor outer panel and lower panel

                              To create a tooling direction based on the reference of edges of the working surface

                              The surface has been offset in to several times at several distance to achieve a required surface

                              Gaps between the surface has been filled up by using law extension with the help of bridge curve

                              The edges of the above surface have extended using a law extension command

                              The reference outer panel offset surface and inner panel offset surface has merged together using a swept command as a reference of bridge curve

                              By using the face blend the sealing surface has been created

       With the help of trim and extend command to create a window fixing surface

       To create a bridge curve on both side one side of the edge is tangent to the surface as g1 and another end is as g0

       To fill the gap between the bridge curve using the through curve mesh also the extra gap has filled up by the extended command

      To create a datum plane, have some offset distance from the edge of surface and to create a hinge mounting base surface

     Create a sketch on the plane surface and has trim out to make a hardness space for the surface

To create a mastic sealant area of the surface and also make a distance limit of 4 to 5 mm

Make a relief between the edges of the surface

For strengthen the flat surface to create a emboss on the surface the create emboss to travel the force outward direction

To remove the material on the top of the emboss to reduce the weight of the sheet

Same as that the wiper motor mounted base and gas stay mounted base has been created

To create a latch same as a hood design method to follow the reverse method

Create a 3d point on the hinge hole to join the point using a line command         

Take a midpoint of the line as a reference to draw a trajectory circle, it has some condition

The circle lies at the middle of the latch surface and the line to be draw tangent to the circle

           The line has drawn on the tangent line perpendicular to the line

            It has 20mm offset to both direction

            To create a surface on the line and has extend using law extension and has trimmed using the trim and extend

            The sharp edges has been blend using the edge blend and also the surface has thicken to 0.75mm

LEFT HAND HINGE REINFORCEMENT

                After thicken the backdoor inner panel to take as a reference

               To make a smooth corner using a curve on surface

               The surface has thickened to 1.5mm

RIGHT HAND HINGE REINFORCEMENT

               Same as the above operation the reinforcement has created

WIPER MOTOR REINFORCEMENT

STRIKER REINFORCEMENT

LH GAS STRAY REINFORCEMENT

RH GAS STRAY REINFORCEMENT

Draft analysis

  A draft analysis is used to see if the draft of a part is sufficient for the moulding process and if the part will separate correctly from the mould. The draft refers to the angle between the face of a part and the direction of pull (refers to direction of the selected plane/face of a part) of each mould side.

Overall design of back door

CONCLUSION

                       Finally, the back door assembly and additionally the emboss and the reinforcement has been created and also the draft analysis has been created