Week 3:- BiW Fixture Design Methodologies Challenges

Q1.)ANSWER:-

 Design Methodology:-

             A three-phase methodology for the fixture design activity has been developed. The three phases include predesign analysis (phase I), functional analysis (phase II), and productivity improvement (phase III). In phase I, the product design information is studied, and initial fixture design aspects are developed.

        

Design Methodology is divided into four sub categories:

• Purchase Order
• Inputs from Customer
• percentage completion criteria
• design output

Purchase Order:

         A purchase order is the order from the customer end for the starting of the work. A purchase order (PO)is a commercial document and first official offer issued by a buyer to a seller indicating types, quantities, and agreed price for products or services. It is used to control the purchasing of products and services from external suppliers. Purchase orders can be an essential part of enterprise resources planning system orders. Companies use purchase orders for several reasons. Purchase orders allow buyers to clearly and explicitly communication their intentions to sellers. They may also help a purchasing agent to manage incoming orders and pending orders. Sellers are also protected by pos in case of a buyer's refusal to pay for goods or services.

       Purchase orders provide benefits in that they streamline the purchasing process to a standard procedure. Commercial lenders or financial institutions may provide financial assistance on the basis of purchase orders.

Inputs From Customer:

        Inputs from customer basically are the data given by the customer like requirements, standards, layouts etc.

                    

• Functional Requirements: The purpose of the function of the fixture will be given as input from the customers like what are the function the fixture is going to do i.e., welding, riveting, gluing, or whether it i.e., a checking fixture etc.
• Preferred Standards: As we know different companies follow different standards, followed by the customers. By following the standards in the time of designing and manufacturing of parts we will be saving the time and cost which will be automatically minimizing the time of the projects. As per the standard parts, it can be easily replaced from the used the fixture to the new fixture which reduces cost.
• Car Products: inputs we get from car products are GD&T, parts list, CAD files of car part, clamp plan, produce assembly process sheet.
• Layout: Layout shows the entire assembly plan to understand the process. Layout provides information of floe of parts, station pitch, robot station, accessories like tool changes and tip dressers, sub assembly links, platform height, loading and unloading sequence heights.
• Ergo data: -As same as preferred standards, different companies for the different standards of ergo data we have to customer standards of ergo data. The inputs of ergo data will be the customer mostly in case of manually operated fixtures. The ergo data is mainly used to make the operator comfortable which may be led to improve the efficiency in cycle time and production Data provides inputs like platform height, maximum and minimum treat from operator to fixture, maximum and minimum height of the fixture, whether the child parts or assemblies are visible while clamping for loading and unloading. Also provides information like loading height, working safety zone of operatories etc..
• Weld study: Weld Study is the important inputs given by the customer: It gives details about the study of particular gun that we use for welding. Also like the number of welds, weld position of the components will be given. In short weld study includes welding gun details, weld Matrix and weld points.
• Standard detailing templates: These inputs include the detailing templates of 2D cad drawing as per the customer standards. So, we have to follow the detailing templates as per the customer standards.

Percentage completion criteria:

It is followed in designing stages and dispatch stages of welding fixtures. It Helps to track or identify how much task is completed and how much to go further for completing a fixture.

Input send concept design -0 to 25%

Concept approval and simulation check -25% to 40%

Design freezing and detailing -40% to 85%

check and final dispatch -85% to 100%

Design Output:

The output is 3D models and 2D drawings of the tools

• Unitized tools: multiple units and their placements on the tool base.
• Layout sheets: a detailed drawing of individual units to include all of their components.
• Non utilized tools: tools that can stand alone and can be detailed completely on a layout sheet.

Hence, the design methodologies are explained in detail.

Q2.)ANSWER:-

     Input required from the customer:

  To start the designing the fixture following are the inputs required for the designing a fixture.

• Functional requirement
• preferred Standard components
• car product
• Layout 
• Ergo data
• Weld study
• Standard detailing Templates.                           

 

Functional requirements:

     The purpose of the function of the fixture will be given as input from the customers like what are the function the fixture is going to do i.e. Welding, riveting, gluing, or whether it is a checking fixture, etc.

It is one of the basic requirements to get from the customer to start designing a fixture.

Preferred standards:

     As we know different companies follow different standards .we will be following the standards, followed by the customers. By following the standards in the time of designing and manufacturing of parts we will be saving the time and cost which will be automatically minimizing the time of the projects. As per the standard parts, it can be easily replaced from the used fixture to the new fixture which reduces cost.

Some of the preferred standard components used in BIW ar Stated below:

• Standards like ABB, NAAMS (North American Association for Mechanical Standards), DESTACO, ZYTRAN, TUNKERS.
• Standard Parts like Risers, L-Blocks, Retainers, Pins.
• Components like Clamps, Cylinders, Slides, Switches, Sensors.
• Weld guns, Tip Dressers, Tool Changers-Tip Dressers are used to sharpen the tip of the tools which are used in robots in various process.

Car Products:

The inputs we get from car products are: GD&T part list, Cad files of car part, Clamp plan, product assembly process sheet.

• GD&T: It provides information of locating pins, rest, clamp, damp & slide unit information of each station .Also includes the information of sequence of openings of clamps, dumps & slide stroke information.
• Part Lists: It gives the lists of parts which are going to be assembled in the fixture. The list contains the information of part number, part name, revision of fixture, part thickness, etc.
• Clamp plan: Clamp plan provides the information of location of pins, Rest units, clamp unit, dump etc. It is the important input from customer. The clamp plan/position should not be changed without the knowledge of customer
• 3D cad file: The 3D model of the car part will be given the customer, from that 3D model we will be developing our fixture design process. The 3D cad file will be in the format of step file (stp) or IGES file igs) process. The 3D cad tile will be in the format of step file (stp) or IGES tile igs).
• Product assembly process sheet: It gives the information of stage wise assembly process like how the parts move from one assembly process to other after the completion of joining process.

Layout:

Lay out shows the entire assembly plan to understand the process. Layout provides information of

•  Flow of parts,
• Station pitch,
• Robot stations,
• Accessories like tool changes and tip dressers,
• Sub assembly links,
• Platform height,
• Loading and unloading sequence heights.

Ergo data:

      As same as preferred standards, different companies for the different standards of ergo data. We have to follow the customary standards of ergo data. The inputs of Ergo data will be given by the customer mostly in case of manually operated fixtures. The Ergo data is mainly used to make the operator comfortable which may lead to improve the efficiency in cycle time and production. Data provides inputs like platform height, maximum and minimum treat from operator to fixture, maximum and minimum height of the fixture, whether the child parts or assemblies are visible while clamping for loading and unloading. Also provides information like loading height, working safety zone of operator etc.

Weld study:

    Weld Study is the important inputs given by the customer. It gives details about the study particular gun that we use for welding.Also like the number of welds, weld position of the components will be fn In short Weld study includes welding gun details. weld Matrix and weld points.

Standard detailing templates:

     These inputs include the detailing templates of 2D cad drawing as per the customer standards we have to follow the detailing templates as per the customer standards.Hence, inputs from the customer to start the designing of the fixture are explained in detail.

Q3.)ANSWER:-

Car Product:

Inputs we get from car products include:

• GD&T
• Parts lists.
• 3D cad file
•  Clamp plan.
• Product assembly process sheet.

Geometry Dimension and Tolerancing:

It provides information of locating pins, rest, clamp, damp & Slide unit information of each station.

Also includes the information of sequence of openings of Clamps, dumps & slide stroke information,

Part List:

Part list gives the information of parts in a unit it consists of part number, part name which helps to identify the part easily, number of parts required and its thickness. This list helps to check all the parts and its dimensions and required number of quantities.

CAD files of the car part:

CAD files of car parts gives the simulations of those 3D models and their analysis is also used throughout the engineering process from conceptual design and layout of products through strength and dynamic analysis of assemblies to definition of manufacturing methods of components,

Clamp plan:

This is the clamping plan while doing the operation-We cannot complain without permission of the customer. It is very important input from the customer. lt provides location of pins, rest, clamps, dumps etc.

If the clamp is nearer to the weld spot, one should not change the clamp position without consulting It even it appears to damage the clamper the tool Design should not change without consulting with superior.

Product Assembly Process Sheet:

It gives information os stage wise assembly process like how the parts move from one assembly station to another after the complition of joining process.It shows the sequence of operation/process to be done in a part or a panel.Also what are the parts to be joined with the panel will shown in sequence.From this sheet we can trace out the pending process which has to further go on for completion of part.From this product assembly process sheet designer can understand the sequence for designing the fixture.

Q4)ANSWER:-

Clamp Plan:

Clamp:

A clamp is a fastening device used to hold or secure objects tightly together to prevent movement or separation through the application of Inward pressure.

Essential requirements of clamps:

All clamps must fulfill four essential requirements. They are,

1. The work piece must be held rigid while undergoing operations
2. The time required for loading / unloading the tool must be as short as possible, which means the clamping device must be quick acting.           
3. when subjected to vibration, chattered, heavy pressure the clamping must be positive.
4. The clamp must not damage the work piece.

                            

CLAMP PLAN:

        Clamp plan provides the information of location of pins, test units, ciamo unit cump etc.It is the important input from customer. The clamp plan/position should not be changed without the knowledge of customer.It gives the detail of the exact position of the camping units by mentioning a co-ordinates the particular position.Clamp Plan is very important input that we get in the car products is where exactly we can place those clamping units are the particular pin Units.We should never change the position of the particular clamp or the pin, which is given in these data.We can change our design a little bit here or there, but we should not change the input design data about the clamp position or the pin position. In the Clamp plan there is clamp unit, pin unit and it is more detailed it also gives the exact location of Y and Z Coordinates designing as well you can just input these coordinates and you can start designing from there.We should never change the position of the particular clamp or the pin, which is given in these data.We can change our design a little bit here or there, but we should not change 'the input design data about the clamp position or the pin position."In the Clamp plan there is clamp unit, pin unit and itis more detailed it also gives 'the exact location of Y and Z Coordinates designing as well you can just input these coordinates and you can start designing from there.

        We should never change the position of the particular clamp or the pin, which is given in these data.We can change our design a little bit here or there, but we should not change 'the input design data about the clamp position or the pin position.

        "In the Clamp plan there is clamp unit, pin unit and itis more detailed it also gives 'the exact location of Y and Z Coordinates designing as well you can just input these coordinates and you can start designing from there,If the three coordinates whole diameter and everything is already given to design the entirefuture design phase, and it sometimes ministry as well, it happens that another thought position, also given very close to the clamp, or the clamp location. So always ask to whether you have changed the clamp position

        You should never change the vent position or the clamp position without asking it so always be valvaboutthese situations So the tool might get damaged or department get damaged so for that itself need to clarify once again before doing any changes in the clamp.

   Hence, this is the clamp plan.

Q.5)ANSWER:-

Layout:

        Layout is basically a layout of the entire assembly line to understand the process flow of work.Layout sheet wilt give you information about all the fixtures are placed the robots are going to work on it.In layout sheet the circle around the robot is called trapped area of that particular robot,So, this is basically the reachability of that robot and which is confined to the particular circle For example robot is going to work on the fixture details also mentioned the geo 250 and then number is given 250, and as you can see 250 02 so 'this is dueling to one or two it is going to use there sq this robot is going to work on the site first. Then after finishing the site. This fixture is going to rotate and then it will come to t 01, and these two robots are going to work on the other side of the fixture similarly this robot is also going to work on the particular component as we this robot is also going to work on the particular component as well.Entire sheet will give you in that plan of the layout of what are the constraints that is there from the customer side itself.If you want to do any changes for example you re changing the geo fixture design and it is going to exceed a little bit bigger or smaller inside you have to inform the customer and you have to get the customers permission to do that so that he will also be able to change the design if we present him with anything.

                          

Layout provides information about:

Flow of parts:

In the flow of parts how the particular component is going to move from one station to another station.

Station pitch:

In station pitch a distance between two stations. What is the space concept that they have between two station.

Robot stations:

Robot stations and positions where the robot placed stations,

Accessories like tool changer and tip dresser.

Accessories like tool changes and tip dresser. So where are those also placed. So that is it the robot wants to change the particular tool, which it has to go to the particular location and change it.

Sub assembly links:

Subs assembly links are basically how the particular fixtures how the assembly fixtures are linked to the mala assembly line.

Loading/ unloading sequence/heights:

Platform height and loading and unloading sequence of height.

Hence, this is the purpose of a layout.

Q6)ANSWER:-

    ERGO DATA:-

         Ergo data is nothing but the data or inputs which gives the human factors engineering data,between operator and his working enviorment.Before detailing about ergo data we should know about ergonomics in details.

• Human factors and ergonomics is the application of psychological and physiological principles to the engineering and design of products,process,and systems.the goal of human error,increase productivity and enhance safety and comfort with a specific focus on the interaction between the human and the things of interest.
• The final assembly of an automobile involves tasks of complex nature.These processes on the least prority for automation.Manual labor is best suitable for assembly operationa with thw aid of minimal level of automation.All the processes improved countinously in oreder to reduce the costs and increse the productivity.
• Ergo data is study to identify and qualify ergonomics working pstures that contributed to the serious devlopement of musule skeletal injuries and thus investigated possible contributary their related causes.

Benifits of Ergonomics:-

• Improved working conditons.
• Reduce physical woorkload.
• Improved work posture.
• Reduced efforts of certain movements.

                   

Q7)ANSWER:-

  WELD STUDY:-

• Welding is predominantely used in automobile industries and requirements for fixtures that ease the welding process is continous devlopement task in any industry.
• Car Body-In-White is complicated steel-structure including 300-500 sheets with compex shape and are assembled by means of welding in 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.
• It includes the study of the weld matrix and the weld point position.These are two types in weld point one is geo weld points which ensures the geometry of the assembly and second is the re-spot weld points which adds strength to the already weled part.

               

Geo weld points:-               

• The geo weld points are which is planned in the geo fixture.
• These weld will determine the position of the panels as per the given data in drawing.
• The geo weld points are represent in red spehere in the weld study inputs given by the coustomer.

Re-spot weld points:-

• The respot weld points are planned in the respot tool.
• Thses weld will determines the weld strength/stiffness of the panel/components.
• The resopt weld points are represnt in green spheres in the weld study inputs given by the coustomer. 

Q8)ANSWER:-         

The criteria for percentage completion inthe designning stage:- 

• The percentage complition criteria is followed in the designing stages and distpatch stages of welding fixtures.
• This percentage complition criteria is follwed to trace the project wehter it matches the commited date given to the customer for handovering the project to them.
• Also it helps us to identify the stages in the projects like how much the project is competed and what are the further stages are in pending to complete which helps us to complete the project on the commited time and date.
• The foue stage of percentage completion criteria are as follow,

    1.Input and concept design:-

              If the project is in the stage of inputs and concept design then the percentage completion criteria of the project will be between 0-25%.

    2.Concept approval and simulation check:-

             If the project is in stage of concept approval and simulation check then the percentage criteria of the project will be between 25%-40%.

    3.Design freezing and detailing:-

           If the project is in the stage of Design freezzing and detailing the percentage completion criteria of the project will bw between 40%-85%.

    4.Check and final dispatch:-

          if the project is competed then it will be ready to distpatch then the percentage of completion will be between 85%-100%.

Q9)ANSWER:-

    Output in Design:-

           Each manufacturer shall establish and maintain procedures for defining and documenting design output in terms that allow an adequate evalution of conformance to design input requirements.Design output procedures shall contain or make reference to acceptence criteria and shall ensure that those design outputs that are essential for the proper functioning of device are identified.Design output shall be documented,reviewed and approved before release.The approval,including the date and signature of the individual approving the output,shall be documented.

          Design and developement output shall:-

1.Meet the input requirement for design and developent,

2.Provide appropriate information for purcahsing,production and for service provision.

3.Contain or referance product acceptance criteria,and 

4.Specify the characteristics of the product that are essential for its safe and proper use.

• A design output is drawing or specification or manufacturing instruction.Design outputs describes all the parts,components and picecs that go into your medical device.Design outputs describe all assemblies and sub-assemblies of your product.
• Output consist of 3D models,2D drawing which is detailing part,BOM and other related document.
• They required two types of drawing sheet as follows:-

1)key sheet:- 

        It shows the index of the unit and their placement on tool base.

                            

2)Layout sheet:-

         Its the detailed drawing individual unit to include all their components.

                      

Q10)ANSWER:-

    

Structuring a design tree:

          A process where all the assemblies and parts are named in a specific standard Different customers have different set of standards and theEvery company, every customer has different standards of their own structural design tree.so, they will be giving a template on how the structuring and detailing of the design is done and you have to follow that particular designingIn the design tree itself if we mentioned that particular name, wherever that part is We can easily know that this part belongs to this one or this station or this assembly on particular unit. So, this helps us to avoid errors during the design study, manufacturing assembly and inspections.Structuring a design tree is actually to avoid the errors, which might come 'during manufacturing assembly, or either in house inspections as wellIf the part, or assembly are not named properly, or design tree is not structured properly, it will create confusion to understand the design and may create major possibilities of making an error.

           Every part, every component should be named according to their procedures.If we did a mistake or renamed the entire standard parts from the customer as a design part customer is going to manufacture the entire part again from the scratch, but he already have that product in his petrary. but extra cost, extra time and is feasible. This is also known as an error which is actually going to increase the cost of the entire assembly as well Naming a fixture or a unit or a part gives the information as to which project zone or assembly they belong.If we name the part properly or name the fixture properly given it will tell us which unit or which assembly or which zone or in which station it actually belongs.In design tree in which designed parts are at top & all standard parts are at bottom.

The blue highlighted number is HIL-T9A-RRFRA-JG3-OO-OO-OO

• HIL-T9A -The project name
• RRFRA - Panel name JG3 -Jig noB 00 - unit no
• 00 - Part no.
• 00 - Component no.

Under the product there are main assemblies, sub assembled child part standard parts ,etc. . these all parts are provided with specific number, zone etc. to identify easily.

Q.11)Answer:-

Units:

           A unit is a device that has a specified function especially one forming art of a complex mechanism-multiple units are joined together in order to form a fixture and are attached to a common base, which serves as a common support to the units where they are fixed.A welding fixture is assembly of different types of units.As name refers, the different units each serves with different functions and different purposes.

Units are classified into two types:

1. Unitized tools
2. Non unitized tools.

1)Unitized Tool:-

                        These tools are process functionalities tools.It has multiple tools for the process.

Rest pin unit:-used to rest the component.

Fixed pin Unit:-used to locate the panel by a fixed pin.

Retractable pin unit:-Used to locate the panel by a retractable pin.

Rough locator Unit:-Used to guide the operator on safe locating of panel.

sensor unit:-Uses some sensors to sense the panel.

Base unit:-Used to mount all other units.

Slide unit:-Uses in complex way as a sliding mechanism involved.

Dump unit:-It's complex unit sets 

Q12)ANSWER:-

 Fixed pin unit consist of riser,blades,block,shims,pin retainer and pin.

    Riser:- Its the standerd part which is used to rise up the height of whole unit.Blades are plates mounted on the riser.Other parts like cylinder,arms stc are mounted on the blade.

   Shims are the small part which comes with the thickness of 0.1mm,0.2mm,0.5mm etc.These will compensate the stacup tolerance which reflects st the panel holding part called mylars.In fixed pin shims are used to adjust to translation motions.

   Pin retainer will support the pin and locating pin which restrict movement of the car panel.

Purpose of fixed pin unit:-

• Fixed pin unit is a unit designed to locate the car panel using pin.
• The fixed pin unit is part of the 3-2-1 principle.It restricts 6 degree of freedom of the car panel.
• Its necessary to have 2 pins to locate car panel.One pin must arrest 4 ways (4 translation) and other must arrest 2 ways (2 rotational)of car panel.       

                                                   

Q.13) Different parts of a Fixed Unit:

The different parts of a fixed units are:

• Locating Pin
• Pin Retainer
• Shims
• Blade
• Riser 

 Locating Pins:

                      Locating pins are used for controlled, fine tolerance positioning of a work piece. Usually, two locating pins are used to properly locate the work piece on one plane. There are dozens of styles of locating pins that can be utilize a design.

                      Locating pins are great way to locating sure the parts are putting together fit they want to fit it. Drill two holes opposite to each other in each part installed a cylindrical locating pin, parts are aligned exactly the way we want. if we are having alignment issues with using just bolts or other fasteners locating pins can be a great way to form up or assembly.

                                  

Risers:

      Risers is structure generally used to mount the toggle clamp & rest, clamp mylars and location pin.It is not necessary to have one riser where all the parts of clamp & rest or location units are mounted.Generally, risers are either made of plate fabrication of plate and tube welding together or from single gas cut plate.These are generally manufactured to give height to the assembled.

                                              

Blade:

Blades are the plates attached to the riser. Parts like cylinder, arm etc. are mounted on the blade. chamfer is given to straighten to the blade.

                                              

Shims:

          Metal shims are used to finely adjust the location of how the fixture holds the product so that it is welded together within the dimensions set for the product to work well. 

          A pack of thin metal sheet is placed between two components in the fixture. The first component is fixed place and second component is attached to the first component with the pack of the shims in between. Removing one shim or adding one shim slightly adjusts the location of the second component. This is important to the manufacturers who want to have their product’s parts assemble easily after being welded.

                      

Pin Retainers:

       A pin retainers is a part which holds the pin in position ,the pin retainer can be either a make a part or a standard part also .Pin retainer is used to hold the locating pins firmly. 

Hence, these are the different parts of a fixed unit.

                                              

Q.14)ANSWER:-

Rest Unit:

           Rest unit is unit designed to support car panel using Mylar/NC block /rest component is rested only, no upper clamp or force applied there. It is the simplest unit design because it has fewer part to design & purpose to the only resting car panel.It can be combined with clamp unit to clamp as well as to rest the car panel. It can be combined with locating unit to locate as well as to rest the car panel. Also locating, clamping and test unit can be combined unit to reduce cost.

           There is no unit to attached it.it has rest Mylar, blade and rise & below are different parts of rest unit. Rest unit is also divided into simple support, units & retractable support unit.

                                    

 The different parts of a Rest unit are:

• NC Block/Mylars
• Spacers/shims
• Blade
• Riser

                         

NC/MYLAR/FINGERS:-

            Mylars is the component which holds the panel while operation.These are placed from top and bottom side also.The top mylar is called as clamping mylar and the bottom mylar called as resting mylar.

spacers/shims:-

           This are small part which comes with the thickness of 0.1mm,0.2mm,0.5mm etc.These will compansate the stackup tolerances which reflects at the panel holding part called mylar.To adjust the mylar at its defined position we use shims so the panel won't deformed and also don't get any impression on it. 

Blade:-

            These are plates mounted on the riser.Other part like cylinder,arm etc are mounted on the blade.

Risers:-

         Risers is the standard part which is used to rise up the height of the whole unit.

Q.15)ANSWER:-

        SENSORS:

Sensor unit:

        A sensor is a device that measures physical input from its environment that can be interpreted by either a human or a machine Most sensors are electronic (the data is converted into electronic data), but some are simpler, such as a glass thermometer, which presents visual data, People use sensors to measure temperature, gauge distance detect smoke, regulate pressure and a myriad of other uses.

Types of Sensors used in general are:

• Proximity sensors
• Photo electric sensors
• Laser sensors

 Proximity sensors:

     A proximity sensor is a non-contact sensor that detects the presence of an object the target enters, the sensor's field. Depending on the type of proximity sensor, sound, light, infrared radiation (IR), or electromagnetic fields may be utilized by the sensor to detect a target.Proximity sensors are used in phones, recycling plants, self-driving cars, Anti-aircraft system assembly lines. There are many types of proximity sensors, and they each sense targets in distinct ways. The two most common used Proximity sensors are the inductive proximity sensor and the capacitive proximity sensor.

      An inductive proximity sensor can only detect metal targets. This is because the sensor utilize an electromagnetic field. When a metal target enters the electromagnetic field, the inductive characteristics: of the metal if change the field property alerting the proximity sensor of the presence of a metallic target. Depending on how inductive the metal is, the age target can be detected greater or shorter distance.

                        Capacitive proximity sensors, on the other hand, are not limited to etc. These se anything that can carry an electrical charge. Capacitive sensors are commonly used in liquid level detection.

                                                                                                

Photoelectric Sensors:

        Photoelectric Sensors detect object change in surface conditions, and other items through variety of optical properties. A Photoelectric Sensor consists primarily of an Emitter for emitting light and a Receiver of receiving interrupted or reflected by the sensing object; 'it changes the amount of light that arrives at the Receiver. The receiver detects this change and converts it to an electrical output. The light source for the majority of Photoelectric Sensor infrared or & invisible light (generally red, or green/blue for identifying colors).

                                          

Laser Sensors:

         These laser distance sensors use a focused, coherent light to measure distance to target object in factory automation applications, the target is usually a product machine element. They detect any solid object an produce an  output proportional to the measure  distance independent of material color and brightness. The high resolution output distance sensors is used to provide position or displacement, usually to the input of some type of industrial controller ,such as PLC is often highly accurate ,and include.includes temperature Compensation to enhance are several types of laser distance sense some including diffuse,

                                                             

 Fundamentals of Sensor Design:

• Every single loose panel, which are being welded in a tool should be Sensed.
• Each panel should be sensed by one or two sensors diagonally opposite ends of the panel
• If a component is really small, we need not use two or three sensors for that you can use one sensor to detect the particular panel.
• If the panel is really big, we will use two sensors in opposite directions to sense the panel.
• So every sensor should be mounted in three directional adjustable ways in general.
• Sensor manufacturers are IFM, OMRON etc.

Q.16)ANSWER:

Rough Locator:

              Rough locator is the element that aim the operator to guide the car panel while loading on to the fixture and ensure full proof assembly.It is used a fool proofing method, because due to the rough locator part cannot be located in correct position. The rough locators are set according to the respective panel. Hence, art can only be loaded in defined direction and orientation.

                                           

FUNDAMENTALS OF ROUGH LOCATOR DESIGN:

• Rough locators should be placed at the edges of the car panel which it has to guide.
• Rough locator has to be placed at the same angle of the car part edge with a minimum distance of 2.5mm from the edge of the car part.
• Rough locator should guide the panel in the pin arresting direction,
• Rough locator should guide the panel before 10-15 mm to start of the pin engagement
• Rough locator should be designed with entry angle for the car panel. Generally, It ranges betweenBO-45 degree. Rough locator should be designed with two slots to mount-the easy adjustments
• The locators should be in the direction of car part guiding.

Q.17)ANSWER:-

Base unit:

          A base unit is the unit designed to mount all the other units (clamp unit in unit, Rest unit etc.) of the tool, also other parts necessary for tool pneumatic valve box, trucking cable path will also be mounted onto a base unit. 

                  

Parts of Base unit:

Parts of base unit are as follows:

• Valve box
• Trunking channel
• Measuring hole cover
• Eye bolt
• Pedestal
• Floor plates.

Valve box:

          Valve box is basically a box which supplies air to all the pneumatic cylindehs assembled 'n the fixture. Valve box consist of one solenoid valve is used to collect the air from the pneumatic cylinders to valve box.

Trunking channel:-

          The trunking channel includes all pressure inlet cables going to penumatic parts of the fixture and protects them from dameging while operation is in process.

Eye bolt:

      An eye bolt is a bolt with a loop at one end They are used to firmly attach a securing eye to a structure, so that ropes of cables may then be tied to it for lifting purpose Eyebolt is used to drag or lift the base unit while relocating.

Pedestal:

Pedestal is a stand like structure where the entire unit of the base will be mounted. Floor Plates used to mount the entire base with floor, Also used to achieve the flatness soft the fixture.

Hence, the base unit and their parts are explain in detail.

Q.18)Answer:-

Dump unit:

                    Dump unit is where you assemble component if you have certain constraint you will have clamp unit, pin unit attached panel will be assembled. So, if you have certain constraint you cannot assemble in normal way. Dump different way, It has dump cylinder & complex design It consists of dump cylinder to perform the operation of clamping & unclamping car panel. A dump unit can have more than one cylinder to perform such operation. The first cylinder dumps the assembly carrying clamp Mylar, pins and then this assembly performs the required operation in this unit, we should make sure that in the open position of panel, we should be able to remove the panel.

                              

Functions of Dump Unit:

          If you have particular constraint and you cannot assemble in a normal way to use this use it in different ways again it has same dump cylinder and it has open position and closed position and it has Clamp Cylinder Unit too.That is why these are very complex and design.If you have any geometrical constraints, you can use this dampener to constrain your components.

Q19)ANSWER:-

   SLIDE UNIT:-Slide unit are positioning units which are used to position the fixture,weld gun,units,robots into position for further operations.Slide units can be classified into two types on the base of type of guide-ways used as 

• Hardened guide ways
• LM guide way

Slide units can be classified into three types on the base of prime mover used 

• Manual slide unit 
• Hydrulic/pneumatic slides
• CNC slides

It may also be classified depending application as

• Horizontal slide 
• Vertical slide
• Angular slide

Guide lines to design the slide unit:- 

• Slide unit essentially consisof LM guides,linear cylinder,Front and rear stoppers,front and rear shock absorber,Two proximity switches/reed switches for sensing the two end positions,bellows or protection cover for rails.
• Slide units are used when we have some space to design different special units and to assemble it.In those case we use sliding units.