Week 5:- Rest Unit & Clamp Unit Design Challenge

AIM
To design 3 Different types of Power Clamp Unit with Different Riser, Blade, and Clamp Arm and design 2 Different types of Rest Unit for the given Car Panel.

INTRODUCTION
A Clamp is a device that is used to hold the part tightly in the assembly. The clamp prevents any of movement of the assembly in the fixture and ensures proper operation on the part without any distortion. The clamp must be placed in such a way that it does not interpret the operation.

The clamp plan provides information on the location of pins, rest units, Clamp units, Dumps, etc. It gives the details of the exact position of the clamping locations in form of coordinates The clamp position in some cases will be in such a way that it might damage the tool, or very near to pin position. In such cases, We should not take the decision to change the clamp plan without discussing it with the customer.

Parts which are used in clamp unit are

1. Finger
2. Rest
3. Clamp Arm
4. Clamping Cylinder
5. Shims

Finger

A finger is an NC Block, Which is mounted on the Clamp arm of the cylinder, and will press the car panels towards the rest, so it holds the car panel.

Rest

Rest is an NC block, which is fixed to the unit to support the car panel, also it resists the clamping force of the finger and thus clamps the car panel. Rest and finger always should be in-line to prevent damage in panel.

Clamp Arm

A Clamp arm is a bought-out part, to which all the movable parts are fixed. In general, a clamp arm is a part of a clamp cylinder. There are three type of clamp arm can be used. A11, A10 and A12.

Clamping Cylinder

A Clamp Cylinder is a pneumatic device that works with pressurized air. The Clamp cylinder is used to. open and close the parts fixed to the clamp arm fixed to the clamp body. Clamp arms gre generally bought out parts.

• Study the PLP (Principle Location Points) data along with the nearby spot data and check the position of surrounding location and clamp units.
• Take an overview of the working height having manual welding. For robotic welding also it’s important to see the working height in consideration of the robotic gun, turn table height if manual loading is done.
• Put the proper gun at the spot location for all the spots near the rest unit. If process engineer has gun shape stick to X, C or Y type of gun. Do the proper gun study and place the gun as per the GEO or re-spot decision and operator approach. Once basic gun is placed considering the throat depth and throat gap start building the clamp and rest block at the PLP.
• Panel section creation: Take a section at PLP either in clamp opening direction or normal direction .Sections should be normal to base. Panel section through X, Y or Z direction passing through PLP.Section will help in finalizing the shape of clamp and rest block. Most importantly used for finalization of gun shape.
• Finalization of a base plate plane – consider following things before deciding the base plate. Height of maximum and minimum weld spot from the floor. No gun arm should touch the base plate. Operator ergonomic while accessing all the spots.
• Construction of Rest Block: If standard Mylar has to be used (Few companies make standard height and length of steel blank with few holes and dowels for clamping) then select the proper blank size as per the requirement; consider 5 mm above the panel.
• Select the clamping cylinder as per the pivot point distance from the PLP. You may choose various cylinder 50 Dia, 63Dia, 80 Dia.as per the requirement (distance of clamp arm from the PLP and no of clamping mounted on each cylinder).

Figure shows three Different Clamp Units

Rest Unit

Rest units are used to rest the panel.

The parts of the rest units are as follows
1. Mylar
2. Blade
3. Risers

Mylar

Mylar is the part that holds the panel from above and below during the operation. The top side of Mylar is called the clamping Mylar. Whereas, the bottom side Mylar is known as resting Mylar. Every Clamping Mylar will have a resting Mylar. It holds the panel in such a way that it does not.deform during the welding process.

Riser
A riser is a part that is used to raise the height of the fixture. The raiser is fixed to the base of the fixture and the blade is mounted on the riser.

Blade

Blades are plates that are attached to the riser.

Result

Thus the Design of 3 Different types of Power Clamp Unit with Different Riser, Blade and Clamp Arm for the given Car Panel and Design 2 Different types of Rest Unit for the given Car Panel are completed.