Week 8:- 3D Finishing - Challenges 1

1).What do you understand by the 3D finish process ?

3D finish process means to finish the design is being completely and make it ready for all final simulation & 2D detailing.

The following are the basic rules to be following in 3d finishing:

1. The nominality of holes is to be checked which ensures the easy assembly of all the units.
2. The hole concentricity & holes sizes should be checked which ensures the easy assembly of different parts.
3. The gap between the different units are checked to ensure the proper individual working of different units.
4. Fasteners are implemented as per the hole size & the standard color code as per the customer requirement are applied to differentiate the type of hole wheather it’s a simple hole, Threaded hole or counterbore hole.
5. The standard colours used for holes are violet for simple hole ,Yellow for Threaded Hole, Cream for machined area, cyan for pin hole.
6. Renaming of the assembly and the parts is to be done to give every part a different identity so everyone can identify in ehich assembly this part is going to be fit.
7. After all the above steps the model is sent for simulation & 2D detailing.

2).What are the points need to be taken care of while finishing the design?

The following points are taken into consideration while finishing the design:

1. Hole concentricity & Hole sizes : All parts are to be cheked for hole concentricity and to be confirmed for easy assembly while finishing the parts.
2. Machining Area : The machining area in every part should be defined and the machining area should be highlighted by using standard color code.
3. Nominality : All units dimensions should be maintained nominal to facilitate easy assembly of the unit.
4. Holes colouring Standard Colour code standard as per the customer requirement should be applied in the 3D finishing . Violet for simple hole, Yellow for threaded hole ,Cream for proper functioning of the units.
5. Pneumatic Layouting : Pneumatic layouting is collection of different pneumatic pipes which works as a inlet to the pneumatic cylinder. It should be done properly for proper functioning of the units.
6. Gaps checking : Proper gap should be maintained between units to avoid the clash between the different units.
7. Fasteners Implementation : Fasteners should be implemented in all unit as per the requirement & load on the part.
8. Mylar splitting as per panel profile : Mylar splitting should be confirmed while finishing the design . This should be done as per the thickness and shape of the panel you have in the fixtures.
9. Proper renaming of parts/assemblies as per standard : Proper renaming of parts & assemblies should be done while finishing the design hence we can identify each & every part easily with identification.

3). What are rough Locators & what is their use?

A rough locator is a part designed to guide the operator , to locate the car panel on tp the pins accordingly. A rough locator can be of standard part or make part.

Rough Locators

Uses of Rough Locators :

• Rough Locators are used to help Locate workpieces in the automation process. Locating refers to the desired location where you want the workpiece to be when it is getting worked on either by a person ,team ,or robot.
• The accuracy of the locating components directly affects the consistency and how the final product will come out .This is why these components are essential to your setup.
• It can be called as food proofing method also. Because due to the rough locator the part cannot be loaded in incorrect position. The rough locators are set according to the angle of the respective panel hence part can be loaded in defined direction & orientation.

4). What are the points you need to consider while designing a rough locator?

Following are the points need to be considered while designing the rough locator

1. Rough locator should be placed at the edges of the car panel, which it has to guide.
2. Rough locators has to be placed in the same angle of the car part edge with a minimum distance of 2-5mm from the edge of the car part.
3. Rough locator should guide the panel in pin arresting direction.
4. Rough locator should start guiding the panel before 10 to 15mm to the start of the pin engagement.
5. Rough locator should be designed with entry angle for the car panel. Generally it ranges between 30-40 degree.
6. Rough locator should be designed with two slots to mount the easy adjustments
7. The slots should be in the direction of the car part guiding.

5). What is the gun study process?

Welding is predominantely used process in automobile industries and requirements for the welding process is a continuouse development task in any industry. In BIW the complicated steel-structure including 300mm to500mm sheets with complex shape and are assembled by means of welding. The first step taken before starting the design of welding fixture is to arrived 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.

The above image shows the weld gun used for spot welding and weld matrix and weld locations where the welding is to be done. There will be two different types of weld points one is geo weld points and respot weld points. Geo weld points are welded in first stretch and the respot welded points are done in second go.

Gun study basically includes the study of the weld gun (A portable device for semiautomatic welding of parts of various articles) which is going to be used for the operation depending upon the size of the part, Thickness of the part etc.

Typical Welding

In the weld gun study the gun which is going to be used while spot welding is checked over the panel by using the 3D software .

The fixture is designed for the car panel to hold it on the position, the weld gun position is checked over the predefined spot weld points, Wheather the gun fall to the fixture unit or not . If the weld gun fall to the fixture unit then redesigning of that unit or the repositioning of that unit is done & again confirmed wheather the gun is falling or not. Fixtures are redesigned if the gun falls to the fixture unit, The weld spot positions remain same.

6). What re the points need to consider during the gun study?

Weld gun study is very time consuming process, the entire welding cycle time study depends on the number of weld spots.

Following are the points need to be consider during gun study

• The axis of weld spot along welding direction must be normal to the weld surface.
• The no. of weld for the panel and the time required to spot the each weld determine the total time required to complete all the weld spots.
• If we have one or more device models and we want to program; the behaviour of each model in the work cell can be simulated over time. Instructions for each device are coded by giving sequences. The sequence defines the motion, manipulation and action of the devices. Based on the distance of each tag point from home position ,motion type ,speed and acceleration – one can obtain cycle time for each device assigned with sequences. This way robot cycle time is precisely calculated.
• After sequencing all the devices, a simulation is run with “collision check ” ON and mode sure that the welding operation is collision free.

7). What is pneumatic routing?

Pneumatic systems should be efficient and leak free. Somtimes, they are not , because of improper tube line routing which resulted due to eiher lack of knowledge, or corners cut on planning time ,or both .

Planning tube line routing is a time investment , but it can have a big ROI , especially for complex systems. During systems design, routing should be developed as the next step after sizing the tube lines and selecting the appropriate fittings.

There are some guidelines provided for as shown below

• Leave fitting joints as possible. Inaccebible joints are difficult and time- consuming
• Leave fitting joints as possible. Inaccebible joints are difficult and time- consuming
• Leave fitting joints as possible. Inaccebible joints are difficult and time- consuming to assemble , tighten and service.
• Use software tools to make labor-intensive calculations such as pressure drop.
• Employ U-bends to allow for line contraction and expansion.
• Include offset bends to allow for motion under load,regardless of how 'rigid ' the system seems.
• keep troubleshooting and maintance in mind. focus on logical design and avoide crossed lines.
• Design the tube line rounting to reduce like lihood of users standing or climbingon plumbing.

• 8). What is the solenoid valve?

  A solenoid valve is an electromechanical valve . Solenoid valves differ in the characteristics of the electric current they use. The strength of the magnetic field they generate, The mechanism they use to regulate the fluid , and the type and characteristics of fluid they control. The mechanism varies from linear action , plunger-type actuators to pivoted-armature actuators and rocker actuators. The valve can use a two port design to regulate a flow or use a three or more port design to switch flows between ports. Multiple solenoid valves can be placed together on a manifold . Solenoid valves are found in many applications areas . Solenoids offer fast and safe switching ,high reliability, long service life, good medium compatibility of the materials used, low control power and compact design.

1. Valve Body: This is the body of the valve to which the solenoid valve is connected. The valve is usually connected in the process flow pipeline to control the flow of certain fluid like liquid or air. Ordinarily the flow from the valve is controlled by the handle,but in case of the automatic valve the solenoid valve is connected to the valve .
2. Inlet port of the valve : This is the port through which the fluid enters inside the automatic valve and from here it can enter into the final process.
3. Outlet Port : The fluid that is allowed to pass through the automatic valve leaves the valve through the outlet port. The solenoid valve controls the flow of the fluid from inlet port to the outlet port. The outlet port is eventually connected to the process where the fluid is required.
4. Coil/Solenoid : This is body of the solenoid coil. The body of the solenoid coil in cylindrical in shape , and it is hollow from inside. The body is covered with steel covering and it has metallic finish . Inside the solenoid valve there is solenoid coil.
5. Coil winding : The solenoid consists of several turns of the enamelled wire wound around the ferromagnetic materials like steel or iron. The coil forms the shape of the hollow cylinder . Externally this coil is convered with the steel convering these wires to the solenoid valve and when the solenoid valve is de-energized the flow of current stopes.
6. Plunger or piston: This is the solid round metallic part cylindrical in shape and placed in the hollow portion the solenoid valve .when the electrical current is passed through the solenoid valve, the magnetic field is generated inside the hollow space. Due tho this the plunger tends to move vertically in the hollow space. When the electrical current is stopped to the solenoid valve, the magnetic field is stopped and the plunger is remain the existing place due to the force of the spring.
7. Spring : The plunger moves inside the hollow space due to the action of the magnetic field against the action of the spring. The magnetic field generated inside the solenoid valve tends to move the plunger , but the spring tends to stop the motion of the plunger in which evr the position it is . This action of the spring against the magnetic field helps keeping the plunger in the position where the flow of current to the solenoid valve is stopped. The spring helps keeping it at the desired position instead of allowing the plunger to fall to the bottom due to gravity when the current to the solenoid valve is stopped. Secondaly, the spring also prevents the movements of the plunger due to force of the fluid flowing through the valve body. If the spring was not there the plunger would have moved up when up when the fluid is present and moved down when the fluid is not there. Thus the spring actually forces the plunger to carry out the control of the fluid . It allows the movement of the plunger only to the extent when the electric current is following through the solenoid valve.
8. Orifice : The orifice is an important part of the valve through which the fluid is flowing. It is the connection between the inlet and the outlet port. The flow of fluid from the inlet port to the outlet port takes place from this port. In the ordinary valves, this port is converted with the valve disc at the bottom of the stem of the valve to which the handle is connected. Thus in ordinary valves, the opening of the orifice is controlled by the plunger. The movement of the plunger is in turn controlled by the spring and the current flowing through the solenoid valve.

Basic Working of Solenoid valve:

Initially the sensor senses the process towards the outlet side of the solenoid valve. When it senses that certain quantity of the flow of the fluid is required ,it allows the current to pass through the solenoid valve. Due to this valve gets energised and the magnetic field magnetic field is generated which triggers the movement of the plunger against the action of the spring. Due to this the plunger moves in upwards directions , which allows the opening of the office. At this instant the flow of the fluid is allowed from the inlet port to the outlet port.

If the current passing through the solenoid valve is constant ,the position of the plunger and hence opening of the orifice remains constant. If the sensor senses that more flow of the fluid is required , it allows the increase in current passing through the solenoid valve, which creates more magnetic field and more upwards motion of the plunger. This leads to further opening of the orifice and more flow of the fluid from the inlet port to the outlet. If the required flow of fluid is less, the sensor allows passage of the lesser current to the solenoid valve.

When the sensor senses that the fluid is no more required in the process, it stops the flow of the current to the solenoid valve completely. Due to this the solenoid valve gets de-energized and the plunger reaches the bottom most position and closes the orifice completely thus stopping the flow of fluid from the inlet port on the outlet port.

In this way the solenoid coil operates the valve as if it is being operated by the human being. When the flow of certain of fluid is required it opens the valve to required it opens the valve to required extent and when the flow is not required it shuts the valve entirely.

9).What is the valve bank?

The directional seated valves are available as chained valves in a valve bank. This facilitates the combination of different circuit symbols or actuation types in order to save space, and such systems can also be used to actuate independent consumers.

There are many valve design variations. Ordinary valves can have many ports and fluid paths. A 2-way valve, for example, has 2 ports; if the valve is open, then the two ports are connected and fluid may flow between the ports; if the valve is closed, then ports are isolated. If the valve is open when the solenoid is not energized, then the valve is termed normally open (N.O.). Similarly, if the valve is closed when the solenoid is not energized, then the valve is termed normally closed (N.C.).There are also 3-way and more complicated designs. A 3-way valve has 3 ports; it connects one port to either of the two other ports (typically a supply port and an exhaust port).

Common Features of valve bank-

1. These are Designed for high vibration levels
2. It use aluminium alloy manifolds for ligh weight
3. These are designed for high temperature environments
4. Design architecture allows easy selection of two to six solenoid valve.

10).What is sensor & brief about its application in automation?

Sensores is a device which detects or measures a physical property and records, indicates, or otherwise respondes to it. A unit designed to sence car panel using electical sensores is called sensor unit . The form the sensors is send to the PLC so the next process is excuted by this signal. The sensore is very sensitive & easily damaged part so sensor cover is provde to the sensor for safety purpose.

Sensors in Automation:

In simple terms, Industrial Automation Sensors are input devices which provide an output (signal) with respect to a specific physical quantity (input). Sensors used in Automation: In the industrial automation, sensors play a vital part to make the products intellectual and exceptionally automatic.

In the industrial automation section, sensors play a very important role to make the products intelligent and highly automatic. These allow one to detect, analyze, measure and process various changes like change in position, length, height, appearance and displacement that occurs in the production sites.

In the industrial automation, sensors play a vital part to make the products intellectual and exceptionally automatic. These permit one to detect, analyze, measure and process a variety of transformations like alteration in position, length, height, exterior and dislocation that occurs in the Industrial manufacture sites.

These sensors also play a pivotal role in predicting and preventing numerous potential proceedings, thus, catering to the requirements of many sensing applications.

The following are the various types of sensors used in automation:

• Temperature Sensors
• Pressure sensors
• MEMS Sensors
• Torque Sensors

11). What are the types of the sensor?

Types Of sensor :

There are many different types of sensors. Here at Variohm, we offer a full range of sensors for industrial and commercial use.

Sensors are used throughout almost every industry for applications which we come into contact with on a daily basis as well as more industrial and specialist applications.

Sensors can be found in the home, the office, in our cars, buses, trains, trams, computers, medical facilities, labs, power plants, restaurants, food processing factories, production lines etc

A Sensor is used to take a measurement, the measurement will be processed and the result of the process, an output will be given. The output will then cause something to change or move. A simple example is the temperature sensor in a thermostat. The temperature sensor is constantly monitoring the temperature, once the measurement taken reaches the desired temperature, the measurement is processed and the output causes the boiler to switch off.

There are many different types of sensors, the main categories are;

• Position Sensors
• Pressure Sensors
• Temperature Sensors
• Force Sensors
• Vibration Sensors
• Piezo Sensors
• Fluid Property Sensors
• Humidity Sensors
• Strain gauges
• Photo Optic Sensors
• Flow and Level Switches

These categories can all be split further into subcategories for example, within position sensors there are the following types;

• Contacting
• Non-contacting
• Rotary
• Linear

And these types of sensors can be split even further, within non-contacting you have the following types of sensors;

• Hall effect
• Capacitive
• Eddy Current
• Ultrasonic
• Laser
• Proximity

12).What are the fundamental points that need to consider while designing or selection of sensor?

The accurate choice of selecting a sensor depends on the knowledge about the application type, the variable of product and the condition in the operating environment. In this article, we will be discussing the factors to be considered while selecting a sensor. There may be other conditions based on specific requirements.

1. While selecting a sensor (temperature sensor, proximity sensor, accelerometer sensor, etc), the range of measuring should directly correspond with the physical measuring range so that we can obtain the most precise reading and optimal sensor lifespan.
2. We must be aware of environmental conditions while installing a product. Numerous sensors can be affected by the environmental conditions (such as temperature variation, gas, humidity, chemicals, etc.)
3. While selecting a sensor, we need to check if it can provide flexibility, like features that can adapt to changing the products.
4. It is always better to use a sensor which gave gives a digital output. It is better to avoid using the analog field devices, even though they minimize the cost because while converting from analog to digital that can produce errors. A digital output equivalent sensors are more worth.
5. It is better to adopt intelligent sensors that can be scaled, calibrated or configured remotely.Smart sensors are those which take up data from the environment and use the predefined function to perform some actions.
6. Precision and Accuracy does not mean the same thing, though they are often related. Accuracy is the quality or state of being correct or while the precision ability of the devices to notice small changes (As an example, a temperature sensor that measures the normal body as 35.999°C has high precision but low accuracy.) The Accuracy and precision and one of a given product should be appropriate. Too high precision can give a wrong indication that the value is too accurate. Similarly, a sensor with good accuracy will be expensive. The error can affect both precision and accuracy.
7. We must provide power to most of the devices. The power which is provided must not introduce any error.
8. Electrical noise is present everywhere, mainly on the production floor which can produce huge errors in reading. So, protection circuits and Signal conditioners can provide some protection.In mobile manufacturing industry ESD safety is a must because electronic products are very sensitive to electrostatic charges so we use a wrist strap, grounded floor mat, heel strap, air ionizer, etc.
9. The sensor must be in such a situation that it can overcome the sudden temperature changes and work properly without producing errors.