Week 7:- Base Unit Design Challenges 1
1.What is the Base unit ? What are the typical parts of the Base unit ?
A base unit is the unit designed to mount all other units (clamp unit pin unit rest unit and ect )of the tool also parts necessary for a tool like penumatic valve boxtrucking cable path will also be mounted on to be base unit
Base unit fundamental component of the fixture because all other component are mounted over it is so every fixture have base unit
the base unit design is different accourding to the panel design of clamp system,locating system
TYPE OF BASE UNIT
BASE PLATE
The base plate is machined plate 20 to 40mm thickness made of steel & Aluminum on to which the hole are drilled to mount the individual unit like clamp unit pin ect of a tool
PEDESTAL
A pedestal is a part which connect the base plate to floor plate . A pedestal is a standard part general & in some cases it can be welded frame integrarted with the base plate
1.A standard pedestal can be of different hieght & different size
2.Depend on the size of the base plate the number of pedestal varies for load distribution
3.A pedestal is of different types with different inclination
TRUNKING CHANNEL
A Trunking channel is duct which accommodates all the penumatic & electrical hoses and wires for the unit of the tool it has thickness of few millimeters
Valve box
Valve box is standard part which will accommodates all the penumatic valve for the units . the valve box is the box which includes different solenoid valve The penumatic fixture works in air pressure provided to it . so the arrangement of air pressure inlet & outlet is done within this valve box
EYE Bolt
Eye bolt are used for the transporting of the tool, using lift holes fork lift holes will also be provided in some cases for transporting
Floor plate
Floor plate is groundet to the floor with fixed bolt on the ground. Floor plate are called foundation plates
1.There will be clearance of 10mm maintained between the pedestal base plate & floor plate
2.This clearance will be used by the leveling screw, for leveling the entire tool
3.Weld bars are used to weld the position permanently after leveling is done
4.A weld bars is a plate along the side of the base plate of the pedestal
2.What are the points need to account while designing a Sase unit?
Following point need to be taken into account while designing the base unit
A) Working height
It depends on the nature of the manual or robotic welding fixture design
for the manual fixture we need cosider the working height 850-1100mm depending upon the working height of the worker standard of a specific country will apply
If the base structure is made with base plate having tubular structure welded below it can reach to height 100mm to 250mm In this case to reach the working welding height we need to provided additional some leg structure which many have to top plate welded to the tube
fundamental base unit design
3. what is damp unit ?
sometimes it happen that there are some hard to reach panel & which cannot fixed by simple unit In such cases to fix them we uses dump unit
dump unit can have more than one cylinder to perform such operation the frist cylinder dumps the assembly carrying clamp mylars ,pin &then this assembly perform the required operation . in this unit such open position we should be able to remove the panel
4.what are the point you need to consider while designing a dump unit ?
3-2-1 principle
Once we have designed the rest mylars pins and clamp and added cylinder for clamping . we will check the resting locating and clamping of the padel being welded. This will be done by the assembly being dumped onto the panel to operate
MASS CONSIDERATION
The Assembly being dumped should have as less weight as possible without reduction in the strength of the assembly. This becauses the lesser the weight lesser will be force required to push and pully the assembly we have to consider factor of saftey as well
Time of opeing and closing
Time of opeing and closing of the clamp should be less. this basically depend on the power and capacity of the cylinder and the weight of assembly being dumped we need to keep it less becauses if it take say 2 second to open then for that time we will not be able to unload the panel which will increase the cycle time resulting in more idel time
Cylinder Validation
Cylinder Validation is an important aspect of the damp unit or any clamp unit design because the cylinder should be able to push the load for operation and then pull it back after operation is complete the centre of gravity of the unit distance between the cylinder centre line and end effectors
5.what is a slide unit ?
A slide unit can have a clamp or a pin or a rest unit attached to which slide forward and perform the required opearation .on completion of the operation slide move back it has cylinder which pushes the assembly forward . Assembly is mounted on a plate which is attached to guide rails there are sensors on the extreme ends of the slides to sense the position of slide
6.What are the point you need to consider while desiging a slide unit ?
Slide unit come under the category of complex units few point that need to be considered
Weight Carrying Capacity
There are different kinds of guide rails avaliable in the mark each having different load capacity. Hence we calculating the weight of our assembly & calculate the weight capacity of the rail Hence we choose rail based on its load carrying capacity
