Week 8:- 3D Finishing Challenge 2

AIM:

• Perform 3D finish for all units of Assembly design.
• Create Rough locators for Assembly.

3D-FINISHING:

3d Finish is a process where the design is being completely finish and to be ready for final simulation and 2d detailing.

• While finishing the design the nominality is checked which ensures the easy assembly of all the units.
• The hole concentricity and holes sizes are checked which ensures the assembly of different parts.
• The gaps between the different units are checked to ensure the proper individual working of different units.
• Design the rough locators, which helps to loading a panel in correction orientation.
• Design the pneumatic lay outing for pneumatic connection.
• Gun study is major and most important part in 3d finishing.
• Selection of sensors, Solenoid valves as per the requirement and implementing in design.
• Fasteners are implemented as per the hole size and the standard colour codes as per the customer requirement are applied to differentiate the type of hole whether its dowel hole, Threaded hole or clearance hole.
• Renaming of the assembly and the part is done to give every part a different identity so everyone can identify in which assembly this part is going to be fit.
• After doing all these things the model is sent for simulation and 2d detailing.

Points Need to Be Taken Care of While Finishing the Design:

The following are the points taken into consideration while finishing the design.

1. Hole Concentricity and Hole Sizes:

All part holes concentricity and hole sizes are checked for easy assembly while finishing the parts.

2. Machining Area:

The machining area in every part should be defined and the machining area should be highlighted by using standard colour code. Machining is to be done on parts to properly Mount with mating parts. Machining only on desired faces reduces cost and save time. And also Machining increases accuracy of dimension. So before going to simulation or detailing machining area should be defined.

3. Nominality:

All unit’s dimension should be maintained nominal to facilitate easy assembly of the unit.

4. Holes Colouring Standard:

In a 3D finish hole colouring should be done because it helps to identify what type of hole it is. It depends on customer standards. Customer specific colour like:

Dowel hole should be given blue colour.

Threaded hole should be coloured with yellow.

Counter bore, open hole should be given cyan blue colour.

5. Pneumatic Lay outing:

Pneumatic lay outing is collection of different pneumatic pipes which work as a inlet to the pneumatic cylinder. It should be done properly for proper functioning of the units.

6. Gaps Checking:

The gaps between the different units are checked to ensure the proper individual working of different units.

7. Fasteners Implementation:

Fast should be implemented in all the units as per the requirement and load on the part.

8. Avoiding Clash Between Different Parts:

Proper gap should be maintained between units to avoid the clashes between the different units.

9. Mylar Splitting as Per Panel Profile:

Mylar splitting as for panel profile should be confirmed while finishing the design.

10. Proper Renaming of Parts or Assemblies as Per the Standards:

Proper renaming of parts and assembly should be done while finishing the design and hence we can identify each and every part easily with Unique Identification.

ROUGH LOCATORS:

• A rough locator is a part designed to guide the panel, to locate the car panel on to the pins accordingly. A rough locator can be of standard part or a make part.
• Rough locators also work as Poka yoke. Poka yoke is a Japanese concept used for mistake proofing.
• Rough locators are also used to help to locate the work pieces in the automation process. Locating refers to the desired location where you want the workpiece to be when it is getting worked on either by a person or a team or a robot.
• The accuracy of the locating components directly affects the consistency and how the final product will come out. This is why these components are essential to our setup.
• It can be also called as fool proofing method. Because without rough locator the part cannot be loaded in correct position.
• The rough locators are set accordingly to the angle of the respective panel and hence the part can be loaded in a defined direction and orientation only.

Points Needed to Consider While Designing A Rough Locator:

The following are the points needed to be considered while designing the rough locator.

• Rough locator should be placed at the edges of the car panel, which it has to guide.
• Applicator has to be placed in the same angle of the car part edge with a minimum distance of 2-5 mm from the edge of the car part.
• Prof locator should guide the panel in pin arresting direction.
• Rough locator should start guiding the panel before 10 to 15mm to the start of the pin engagement.
• Applicator should be designed with entry angle for the car panel. Generally, it ranges between 30-45 degree.
• Rough locator should be designed with two slots to mount the easy adjustment.
• The slot should be in the direction of car part guiding.

GUN STUDY:
Welding is predominantly used in automobile industries and requirements for fixtures that ease the welding process is a continuous development task in any industry. Car Body-In-White (BIW) is a complicated steel-structure including 300~500 sheets with complex shape and are assembled by means of welding in a high rhythm through 55~75 robotic work-stations. The foremost step taken before starting the design of welding fixture is to arrive at the spot weld locations. The location and orientation of other critical units of the fixture including clamps, locators etc., are decided based on the weld spot distribution. The weld spots for Front door inner panel Side bracket assembly are located as shown in Table 1 with respect to the body line of car. It includes the study of the weld gun (A portable device for semiautomatic welding of parts of various articles) which is going to be used for the operation depending on the size of the part, Thickness of the part etc. It includes the study of the weld matrix & the weld point positions. There are two types in weld point one is geo weld points which ensures the geometry of the assembly & second is the Re spot weld points which adds strength to the already welded part.

The device used to make spot welding on the panel is called Gun. The Gun may differ depending upon the application. Fixtures will be designed by considering the weld spots on the panel. After designing the Fixture, the CAD file of the gun be placed on the weld spots to check whether the Gun is clearances with the Fixture. After adjusting the Fixtures, the coordinates of the welds be taken for further operations of Weld Gun.

Points needed to consider during gun study:

Weld gun study is very time-consuming process, the entire welding cycle time study depends on the no. of spots & weld gun study.

Following are the points need to consider during gun study.

• The axis of weld spot along welding direction must be normal to the weld surface.
• The no. of weld spots for the panel, the time required to spot each weld & the total time required to complete all weld spots.
• If we have one or more device models & we want to program, the behaviour of each model in the work cell can be simulated over time. Instructions for each device are coded by giving sequences. The sequence defines the motion, manipulation & action of the devices. Based on the distance of each tag point from home position, motion type, speed & acceleration one can obtain cycle time for each device assigned with sequences. This way robot cycle time is precisely calculated.
• After sequencing all the devices, a simulation is run with “collision check” ON & made sure that the welding operation is collision free.

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CONCLUSION:

Hence, 3D finishing is performed on the designed Assembly of Fixtures and Rough Locators were designed for the given panel