Design of Clevis Clamp Unit and Pin Clamp Unit using CATIA
OBJECTIVE:
- Design 3 Different types of Clevis Clamp Unit with Different Riser, Blade and Clamp Arm for the given Car Panel.
- Design a Pin-Clamp Unit for the given Car Panel.
Clevis Cylinder:
Clamp cylinder can order by giving follows input to manufacturer
Here I use Clamp cylinder in my design is CKG1_B_63_100Y
Nomenclature :
CKG1: Series of cylinder
B: Clevis width=19.5
63: Bore size
100: Cylinder Stroke in mm
Y: End Bracket i.e. Double Knuckle joint (M6 without tap)
Typical parts of Clevis clamp unit:
1 | Clamp cylinder
In the clevis clamp unit, swivel type cylinder is used. as shown in fig,
Pneumatic cylinder (sometimes known as air cylinder) are mechanical devices which use the power of compressed gas to produce a force in a reciprocating linear motion.
Like hydraulic cylinder, something forces a piston to move in the desired direction. The piston is a disc or cylinder, and the piston rod transfers the force it develops to the object to be moved. Engineers sometimes prefer to use pneumatics because they are quieter, cleaner, and do not require large amounts of space for fluid storage.
Because the operating fluid is a gas, leakage from a pneumatic cylinder will not drip out and contaminate the surroundings, making pneumatics more desirable where cleanliness is a requirement.
Once actuated, compressed air enters into the tube at one end of the piston and imparts a force on the piston. Consequently, the piston becomes displaced.
2 | Finger
A finger is an NC block, which is mounted on clamp arm of the cylinder, and press the car panel towards the rest, so it holds the car panel.
Mylar: Called as Rest or Clamp block which is used for holding 2/3 BIW sheet metal parts. Mylars are also called NC blocks. In German language Mylar is called as counter stein. Mylars plays an important role in the BIW welded assembly geometrical accuracy. Mylars are made of steel or in plastic material.
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.
3 | Clamp Arm
A clamp arm is taking part, it's made as per the position of clamp cylinder, stopper and shim. clamp arm made from hard material.
4 | Stopper
The function of the stopper is to restrict clamp going beyond the limits. the stopper is mounted between clam arm and rest or blade. the stopper has two-part when this two-part meets they restrict motion.
5 | Blade
The blade is made part, designed according to the position of the riser, clamp cylinder, clamp arm, rest mylar and stopper.
6 | Riser
The riser is a standard part, which provide height to the Pin unit, clamp unit as per requirements. The riser should have adequate strength so it can sustain under a load of car panel, clamping cylinder, blades.
Swivel Clamp Unit :
DESIGN TREE:
- Structuring a design tree implies a process where all the assemblies & parts are named in a specific standard. Different customers have a different set of standards to structure a design tree.
- It is an important process which helps us to identify a specific part or assembly as to which project, tool/unit, it belongs to.
- This helps us to avoid the errors during design study, manufacturing, assembly, inspection, etc.
- If the parts or assemblies are not named properly or the design tree is not structured properly, it will create confusion to understand the design & may create major possibilities of making an error.
- The naming of a fixture or a unit or a part gives the information as to which project or zone or assembly do they belong.
- It can help us to identify the number of items of the same types or different types that are being used in the assembly.
- While start designing a fixture, the first unit will be the base unit.
- In a structure tree, all the manufacturing parts should be first and the standard parts should be at the last.
- Structure tree helps to study or understand the parts in the assemblies easily.
Factors should consider while designing a clamp unit:
- There should be adequate space between the cylinder and another part like riser, car panel. because cylinder moves or swing while opening and closing.
- Pin clamp unit is used where two panels or component are located and clamp for welding. as shown in fig no. 2
- Clamp make in such a way that it clamps two-car panel at once.
- every clamp mylar/ NC block should have rest mylar/ unit.
- Clamp unit has shims in only one direction as shown in fig
- All parts should snap and butt properly to each other.
- make sure that parts of the clamping unit are min 10 to 12 mm away from the car panel, so they do not damage the car panel.
- Design tree should be structured in a way that makes a part on the top and followed the standard part.
- in this design dia. 63 bore and 100 mm stroke size clevis clamp cylinder are used.
- The position of clevis joint pin will be in one line as shown fig.
- Avoid any clash, it will not rise issue at assembly.
- The product should design in such a way that it will easy to make, assemble and quality check.
- We should preferably usw quick-acting clamps. the clamping method must not damage our workpiece. The clamp should open in such a way that clamp arm moves away from the operator.
- There must be adequate clearance for loading and unloading. so that the process becomes fast and easy. the variation in size must be accepted.
- avoid sharp edges and corner, they can harm the operator and cause to the serious injury. provide chamfer or fillet to corner.
- Must possess sufficient rigidity and robustness. it should not vibrate, as it can lead to unwanted movement of the workpiece and tools.
- Must ensure total security in the operation.
FINAL ASSEMBLY: