Fender Design

FENDER (FRONT

AIM:

The main object is to design the BIW(Body in white) of front fender using the fender skin data and master section as the into data by using CATIA V5

INTRODUCTION

Fender is the american english term for the part of an automobile, motorcycle or other vehicle body that frames a wheel well. Its primary propose is to prevent sand, rocks, mud, liquids, and other road spray from being thrown into the air by the rotating tire. Fender are typically rigid and can be damaged by contact with the road surface.

Sticly materials, such as mud, may adhere to the smooth outer tire surface, while smooth loose objects, such as stones, can be become temporarily embedded in the tread grooves as the tire rolls over the ground. These materials can be ejected from the surface of the tire at high velocity as the tire imparts kinetic energy to the attached objects. For a vehicle moving forward, the top of the trie is rotating upward and forward, and can throw objects into the air at other vehicle or pedestrians in front of the vehicle. Fender is a front outer side member of a car, which covers the wheel side. It has so many small features with ups and downs.

THE IMPORTANCE OF CAR FENDER

1. The fenders are an intricate sheet of metal covering the wheel well of your car.
   
   
2. Fenders are designed in a manner to provide resistance against wind and other roadside debris.
   
   
3. When you travel on rough terrains tour vehicle might get minor scratches and dents which look no better. Frequent road bumps can cause your cars paint to chip off which needs a paint job done.
   
   
4. The car fender are located on either side of the front and rear wheels. The front car fenders begin where the front door hinges run and end just before the bumper. The rear car fenders begin where the back doors close and terminate before the back bumpers.

TYPES OF FENDERS

There are two types of fenders,

1.FULL BUMPER TYPE

2.HALF BUMPER TYPE

1.FULL BUMPER TYPE

This type of bumper is not commonly used because this design is more scrap producing one during manufacturing. The blank of steel or aluminum usedto produce this type has more wastages. This type is not economically good to manufacture.

2.HALF BUMPER TYPE

This types of fenders most commonly used. The con's of full bumper type is satisfied in this design, and the blank area of wastage while producing the part is drastically reduced by scrap management.

PURPOSE OF FENDER

Cleanliness: Protect the car, occupants and passers by from items, water, mud, snow, ice, thrown off the tires as you drive.

Safety: Protects pedestrain from the wheel, e.g. its better to be it by a laterally moving fender than a rolling tire, keeps loose, streaming items from being wrapped up in a rolling wheel.

Aerodynamics: Smooths the car profile so you don't get a lot of drag off the uncovered wheels. Some fenders are enclosed on the side for this.

General Appearance: Looks better with fender, gives a finished look, looks more streamlined.

FENDER MOUNTS

As we seen earlier, the mounting areas in a fender is said to be the fender mounts. These fender mounts are classified according to its position like,

• Bumper mount
• Drip
• A-pillar mount
• Sill mount and
• Baffle mounts.

Fender mounts and its associated areas are shown.

MANUFACTURING PROCESS

The manufacturing process includes the following steps that firstly, unfolding and shearing are carried out on a plate, wherein a proper cold roll specification is selected at first, a cold roll is unfolded, and then the unfolded cold roll is sheared to an iron plate of the corresponding size according to production material specifications; secondly, oil pressing and punching are carried out, wherein the iron plate is extended at first, then side shearing and punching are conducted on the iron plate, folding and shaping are carried out on the iron plate, and finally reshaping is carried out on the iron plate; thirdly, small first parts of the fender are machined, wherein first of all, the iron plate is punched to a needed outer contour blank, then the iron plate completing the outer contour blank is further shaped, and the iron plate is punched at last.

Stamping (also known as “pressing”) is the process of placing flat sheet metal in either blank or coil form into a stamping press where a tool and die surface forms the metal into a net shape. Stamping includes a variety of sheet-metal forming manufacturing processes, such as punching using a machine press or stamping press, blanking, embossing, bending, flanging, and coining. This could be a single stage operation where every stroke of the press produces the desired form on the sheet metal part, or could occur through a series of stages.

Stamping sequence is shown.

DESIGNING

MASTER SECTION

Master sections are the 2D outlines which is taken at a particular area of a 3D model or it is an intersection of 3D model about a reference plane to study its outline (or boundary) in a 2D view. These master sections are widely used in OEMs and in automotive industries to convey the functional requirements of commodity to the design engineer.

It gives the parameters like length, width, height, radius and clearance should be considered while designing the particular part or component.

For this project, the given master section gives the parameters to be considered while designing the fender drip mount.

• The drip mount should have atleast or minimum 150mm of clearance at the front side of fender for headlight housing.
• And at the back side of fender, there should be minimum of 200 mm and maximum of 300mm clearance for the cowl (wiper mounting part).
• Then the hood side drip depth must be 40mm or less as maximum productivity is achieved at the depth of 40mm. If depth exceeds 40mm, rigidity bead is to be provided. Also, forming is not feasible if depth exceeds 60mm due to wrinkling and spring back.
• The initial extension of drip flange must be minimum of 3º draft and then a 8mm extension with 40º draft with respect to the previous flange should be maintained with another extension having 5º draft to improve the aesthetics of parting gap between hood and front fender. And all these drafts must be in positive tooling direction.
• Then the extension for fasteners from flange must not exceed 25mm to maintain the clearance of 10mm or more between the engine room and fender drip.

We have to check the styling parameters also, before designing the fender to avoid error at early stage. Those parameters are,

• A parting shall be provided within a range of 47.5mm from SRL (reference line on the hood side: a line in which the fender makes contact with the surface inclined by 45º with respect to GL), if there is no problem in terms of styling.
• The height shall be 80mm min (child, and WAD1700 Max).
• The height in the range of WAD 1700 min shall be 94mm (+14mm that corresponds to the amount of increase in inertial energy) to meet the adult impact requirements.

INPUT

The given master section to create the drip area and for the still mount, Bumper mount and A-pillar mount create your own design according to the engineering standard.

DRIP MOUNT AREA

It is most important mounting unit of a fender. Its connected with the engine compartment and therefore a lot of design constraints are to be followed while designing the drip area. It should have sufficient clearance from the front and rear end of the fender to accommodate the cowl mounting region and the headlamp housing unit respectively.

From the master section we have optimize value for draft , drawing and assembly point to view. Such as distance from the engine comportment is 10mm, height of fender etc.

Drip mount is shown.

• The given styling surface already have the initial flange for the mountings.
• In the working surface by using “offset curve in surface or face” command, the lower curve of the blend is offset to 5mm.
• Then using “curve on surface” command, necessary curves were created on this flange with respect to the offset curve to remove the unwanted regions of the flange.
• For the drip area, two planes were created at the front and back of the fender with respect to the master section.
• After creating the planes, intersection curves are created about these planes on the fender surface.
• Then the law extensions are carried out to create the drip mount according to the master section.
• And the sharp edges of the extensions were blended with the face blend command and again the dimensions are taken from the master section.
• Before applying face blends, the darts are created using the dart command to give some support to the flange.
• After creating the drip flange, a plane is created with respect to its flat surface to create the sketch which is going to contain the clearance for fasteners.
• With help of this 2D sketch, the required embosses were created on the drip flange with respect to the plane created before to obtain flat surface for ease of mounting.
• Finally, the clearance for fasteners were created using the sketch in the embosses.

BUMPER MOUNT

It is a mount in the front fender, which is used to assemble it with the bumper part.

Bumper mount is shown.

• The unwanted region in the flange is trimmed off with the help of curves which are created before using the “curve on surface” command.
• Then law extension command is applied to create the required extension which is normal to the fender flange surface and its sharp corners were trimmed with help of bridge curves.
• A new plane is created with respect to the extension created before. On this plane 2D sketch is created and projected to the bumper mount extension.
• With help of this projected curves, embosses and fastener clearance holes were created.
• The support darts also created in a certain gap, to provide extra strength to the mount.
• Finally, the blends were created at the sharp edges and corners.

BAFFLE MOUNT

It is a mount in the front fender, which is used to assemble it with the baffle or splash part.

Baffle mounts are shown.

• The unwanted region in the flange is trimmed off with the help of curves which are created before using the “curve on surface” command and its edge is extended to a certain distance.
• A new plane is created with respect to the extension created before. On this plane 2D sketch is created and projected to the bumper mount extension.
• With help of this projected curves, the clearance holes for the baffle push-pins were created by trimming the flange surface.
• The same procedure is followed for next to flanges also.
• Finally, the blends were created at the sharp edges and corners.

SILL MOUNT

It is a mount in the front fender, which is used to assemble it with the sill (sill is the lowermost part associated at the sides of vehicle BIW).

Sill mount is shown.

• The unwanted region in the flange is trimmed off with the help of curves which are created before using the “curve on surface” command.
• Then law extension command is applied to create the required extension which is normal to the fender flange surface and its sharp corners were trimmed with help of bridge curves.
• A new plane is created with respect to the extension created before. On this plane 2D sketch is created and projected to the bumper mount extension.
• With help of this projected curves, embosses and fastener clearance holes were created.
• The support darts also created in a certain gap, to provide extra strength to the mount.
• Finally, the blends were created at the sharp edges and corners.

A PILLAR MOUNT

It is a mount in the front fender, which is used to assemble it with the A-pillar of a vehicle BIW.

A-pillar mount is shown.

• The unwanted region in the flange is trimmed off with the help of curves which are created before using the “curve on surface” command.
• Then law extension command is applied to create the required extension which is normal to the fender flange surface and its sharp corners were trimmed with help of bridge curves.
• A new plane is created with respect to the extension created before. On this plane 2D sketch is created and projected to the bumper mount extension.
• With help of this projected curves, embosses and fastener clearance holes were created.
• The support darts also created in a certain gap, to provide extra strength to the mount.
• Finally, the blends were created at the sharp edges and corners.
  

  Design Criteria :

  • Embosses are provided to increase the strength.
    
    
  • Smooth curves are designed for easy manufacturing of panel.
    
    
  • Maintain extra 10mm from the flat surface for the fastner holes.
    
    
  • All fillets should maintain 2 or 3mm radius in most regions.
    
    
  • Thickness of fender is 0.75mm.

RESULTS

CONCLUSION,

Thus, all moounting areas for the fender designed from skin data and master section is done by following all design rules .