Week 3:- BiW Fixture Design Methodologies Challenges

Q.1-What is Design Methodology?

Design Methodolo&Y- is sequence of steps which we have to follow while doing design.

Above image is of design methodology and steps involve in it.

• Purchase Order: We start designing after customer gives us purchase So, basically it is indication to start designing of particular fixture.

• l nP-uts from Customer: Customer gives us requiremements or specifications of fixture before startingactual design So, we have to design fixture by considering all the points of customers.

• Percentage ComP-letion Criteria:To complete design in time we have to create schedule or time plan called Percentage Completion In this we mention all activities related to design and time required to complete that task like concept design, finalfinished design and 2D of all units in fixture etc.

• Design OutP-ut: Design Output consist of lots of data like 30 and 2D documents,

VMC IGS files, STEP files, gas-cut or laser­ cut files in dwg format and BOM,etc. We have to give these data to our customer as design output.

Q-2What are the inputs required from customers to start design a fixture?

Following are the I/p from customers to start design work:

• Function Reuirement: Generally, function requirement means for what purpose we are goingto design fixture like welding, gluing or riveting fixture and inspection
• Preferred Standard ComP-onents: While designing fixture, we have to use standard components as much as possible to save time, money and efforts to design, manufacture that non-standard components.Car Product: It consist of 30, read files, geometric tolerance and PLP (principle locating points) of

• out: Layout is nothing but management of space which helps to understand process or flow of work of entire assembly line.
• Ergo data: Every company have standard ergo data and they provide it to fixture designer to designfixture consideringthat points height of fixture is decided according to ease while working on fixture. So, we have to design a fixture by considering safety, easy and fool proof design.
• Weld Study: In this input, customerspecify which type of welding (spot or seam) is required to ioin components

Q.3 What is the input we get from "Car Products"?

• GD & T: GD & T stand for Geometrical Dimensioning and Tolerance. GD & T of each part is given in car product in which information of locating pins, clamps, rest and slides are mentioned. Image provided below shows how GD & T is apply for particular part
• Part List: It states about the parts and assembly styl Part list consist of unique part names of each and every parts in assembly and each part has its own part number which helps while assembly process to identify each and every part in assembly.

• Cad Files of Car Part: 30 cad files of parts are necessary while designing
• ClamR Plan: It is one of the important data whie designingfixture because clamp plan mentions location of clamps in which component is going to clamp

• Product AssemblY- Process Sheet: In product assembly process sheet,sequence or stages of assembly ofcomponents are given.

Q-4 What is the Clamp plan?

Clamps are nothing but a mechanism or component used to hold or clamp job in fixture sucurely. Clamps are manual type, hydraulic type or pneumatic type depending on customer requirement. Clamp plan mentions or gives the

location of clamps in which component is going to clamp. We can't change clamplocation without customers approval, first of all we have to take permission from customers side to change clamp location.Clamp plan also provide information regarding location of pins, rest, clamps and dumps.

Q-5 What is the purpose of a Layout?

ANS. Layout is nothing but management of space which helps to understand process or flow of work of entire assembly line. Below image is one of the example of layout.

Q-6 What is Ergo data?

Every company have standard ergo data and they provide it to fixture designer to design fixture considering that points Ex. height of

fixture is decided according to ease while working on fixture. So, we have to design a fixture by considering safety,easy and fool proof design.

Ergo Data is used to reduce human errors, increase productivity, human comfert and safety.

Q-7 What do you understand by Weld study

Weld Study is nothing but a study of welding gun that we are going to use in welding fixture and where we are going to weld. It consist study of welding gun details, weld matrix, weld point, geo weld points and re-spot weld points, etc. Weld study consist of study following points:

• Weld Gun Details: In this we are going to study which type of gun is suitable for particular fixture and selected gun

• Weld Matrix and Wel d Points: Weld points are the points where welding is to be

• Geo Wel d Points and Re-sP-ot Wel d Points: Weld Points are divided usingcolor code, one of them is red color points and remaing points has green col In these, red color points indicate geo weld points which are going to weld in geo tool and green color points indicate re-spot weld points which are going to weld in re-spot tool.

Q-8 What are the criteria in percentage completion in designing stage? Explain it in detai

ANS:To complete design in time we have to create schedule or time plan called Percentage Completion Criteria. In this we mention all activities related to design and time required to complete that task like concept design,final finished design and 2D of all units in fixture etc. The persentage completion criteria is as below:

• 0-25°/ o (lnP-ut & ConceP-t Desigot In this stage of percentage completion criteria, we have to built concept design of fixture in this stage.
• 25-40° / o (ConceP-t AP-P-roval & Simulation) In this stage, concept design is approved by customer and gives some correction points if any. Later we have to to give working simulation of fixture for better understanding of how fixture
• 40-85°/ o (Design Freezing & Detailingt Ifall requirements and specif ications of customers are satisfied then design is freezed and detailing work starts.
• 85-100° / o (Check & Fi nal DisP-atch) In this stage, quality checking is done using CMM (coordinate measuring machine) and then dispatched to customers.

Q-9 Brief about "Output" in design?

Design Output consist of lots of data like 30 and 20 documents, VMC IGS files, STEP files, gas-cut or laser-cut files in dwg format and BOM, etc. We have to give these data to our customer as design output. The basic output are 30

models and 20 drawing of fixture. Output are classified as below: Uni tised Tool: This toolconsist of two type of sheets, they are as follow:

• l<eY. Sheet: Key sheet mentioned or shows thelocation of every units in fixture.
• LaY.out Sheet: Layout sheet is detail drawing of particular unit in fixture.

• Non-uni tised Tools:This type of tools don't require key Ex. stands and tool changer. Tools that can stand alone and details in layout sheet.

Q-10 What do you understand by structuring design tree? How does it reduce errors during design process?

ANS. Structuring a design tree is very necessary whi e designing fixture because it help to identify all manufactured part in whole fixture. Every customer company have there own standard.This will help us during design study,manufacturing and inspection to avoid errors.If we ignore structuring a design tree it will crete confusion to understand design and may errors willappers in fixture.

Q-11 What are Units ? Mention 5 types of

Unit is nothing but a assembly having specific function like clamping,location or resting.In fixture there are number of units. According to 3-2-1 principle of location fixture is designed having two major purpose of clamp and locate the component for which fixture is designed. Image shows fixture consist of different units

• Fixed Pin Unit: Fixed Pin Unit is non movablelocating unit which arrest movement of component in fixture.
• Retract Pin Unit: Retract Pin Unit having retracting unit which is used to move pin to ensure proper loading and unloading of
• Rough Locator Unit: This unit help operator for correctloading of component.

Q-12 Describe Fixed Pin units & their purpose

Fixed Pin Uni t is non movable locating unit which arrest movement of component in fixture. Fig. shows an example of fixed pin unit. It consist of pin, pin retainer, blade, two way shims or spacer which control X, Y direction adjustment, block and riser.

PurP-ose of Fixed Pin Unit are as below:

• Main purpose of fixed pin unit is to locate component
• This unit is used arrest 6 degrees of freedom of component
• Two pins are used to locate First pin restricts 4 translational motion and other one restricts 2 rotational motion.

Q-13 What are the different parts of a fixed unit?

Fixed Pin Unit is non movable locating unit which arrest movement of component in fixture.Fig. shows an example of fixed pin unit. It consist of pin, pin retainer, blade, two way shims or spacer which control X, Y direction adjustment, block and riser.

Purpose of Fixed Pi n Unit are as bel ow:

• Main purpose of fixed pin unit is to locate component
• This unit is used arrest 6 degrees of freedom of component
• Two pins are used to locate First pin restricts 4 translational motion and other one restricts 2 rotational motion.

Q-14 What is the purpose of making a Rest unit & describe its parts

rest unit is one of the simplest unit to fixture to clamp the surfaces of he carthe main components of the simple rest unit are riser,blade,shim or spacer,myler

Riser

risers are used for incrrease the Ht of unit to standard parts

Blade

blades are bolted to the unit body

Shim or Spacer

shims are used to compensate tolerance stack up in we need to control two direcio that are XandY using shim

Mylar

mylers are parts in rest unit which are in contact with ca panel or component used to give support to component.

Q-15 What are the basic fundamentals to design a Sensor unit?

sensor is a device which detect or measure a physical property the unit which is built to sense component or car panel using electrical sensor called unit sensor the O/P signal sensor to PLC

Q-16 What is a Rough locator unit & what are the basic fundamentals to consider while designing it?

rough locator are the parts used to locate components in correctly in the fixture.basically it guide the operator while load component in fixture

fundamentals

• they are used to guidde the component
• the angle in locator should according to component
• entry angle should to be 30 to 45 degree
• for easy adjustment rough locator mounted on base with two slots in it

Q-17 What is a Base unit and describe it's parts?

as name suggest base unit is used to nprovide base for ither units such as location unit is rest unit or sliding unit

• floor plate is used to join fixture and floor
• weld bars and pedestral are support or base on which fixture is mounted
• eyebolt is used to move fixture on its place using cables or rope
• measuring hole cover are also known as tooling hole from which other holes on bae are basically reference holes
• base plate on which all units are mounted called on both plate and it achieve parallism

Q-18 What is a Dump Unit and what are its functions

Q-19 What is a Slide unit? Mention where Slide units are commonly used.