HMT Limited Project Report

8/11/2019 HMT Limited Project Report

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INDUSTRIAL FAMILIARISATION

A project report on Summer Training

BACHELOR OF TECHNOLOGY

In

MECHANICAL ENGINEERING

By

RAHUL THAKUR 1021130122

DEPARTMENT OF MECHANICAL ENGINEERINGSRM UNIVERSITY, NCR CAMPUS, MODINAGAR-201204,

GHAZIABAD, U.P

ACKNOWLEDGEMENT


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Firstly, I wish to express my deep gratitude to all the concerned persons

without whose generous cooperation and coordination, it would have been verydifficult for me to have a successful training experience in the organization.

It would like to thank Mr. V. K. Grover for giving me a golden opportunity

of industrial training, which would help me to enhance my technical skill and helps

me a lot besides some technical skills.

I am extremely grateful to the management of HMT, Pinjore for giving me

an opportunity to pursue four months training in their reputed organization. This

provides me a wonderful and learning experience for me to go through this

training.

Finally, I would like to thanks all those colleagues who help me out of

intensifying my technical knowledge and provide satisfactory solutions to my all

queries.


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INDEX

12. PPT

13. Sheet Metal and Welding

Sr. no. Particulars Page no.

1. Introduction 4

2. Company profile 5-8

3. Foundry and Pattern Shop 9

4. Heat Treatment 10-14

5. Planning 15-16

6. MTK Small Parts 17-20

7. MTK Heavy Parts 21

8. NH/NL Lathe Assembly 22-23

9.

10.

CNC Assembly

Plant Service

24-26

11. Tool Room

27-28

30

31

32


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INTRODUCTION

HMT Limited, formerly Hindustan Machine Tools Limited, is a state-owned

manufacturing company under the Ministry of Heavy Industries and Public

Enterprises in India

Hindustan Machine Tools was incorporated in 1953 by the Government of India as

a machine tool manufacturing company. Over the years diversified into watches,

tractors, printing machinery, metal forming presses, die casting & plastic

processing machinery, CNC systems & bearings. HMT is headquartered at

Bengaluru ( Bangalore ). Successful technology absorption in all product groups

through collaborations with world renowned manufacturers and further

strengthened by continuous in-house R&D. Today, HMT comprises six subsidiaries

under the ambit of a holding company, which also manages the tractors business

directly.


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COMPANY PROFILE

Birth of HMT

In 1949 the idea of public sector tools was commissioned to be a corner stone for the

governments industrial development plans. This led to the birth of HINDUSTAN MACHINE

TOOLS at Bangalore in 1953 which started a single machine tools factory to produce lathes at

Bangalore, in collaboration with M/s Oerlikon of Switzerland.

Next, the company widened its product range beyond lathes by entering into technical

collaboration with other international leaders in machine tools such as Fritz Werner, Herman

Kolb, Errantly Somua, Gildermeister, Liebherr etc.

The second machine tool unit was set up in Bangalore in 1961 making use of the

Companys own resources. The company diversified itself when, in collaboration with Citizen

Watch Company of Japan, the first watch factory was setup in Bangalore in 1962 to produce

hand watches.

The third machine tool unit was set up in 1963 at Pinjore, Haryana to produce milling

machines. In next few years, Machine Tool Units were set up at Kalamessary in Kerala and in

Hyderabad. The Printing Machinery division was attached to machine tools factory at

Kalamessary to qualities Printing Machine.

HMTs tractor business commenced its operations in 1971 in technical collaboration with

M/s MOTOKOV, Czechoslovakia because of the priority given to the agriculture in the national

development plan and to take advantage of the green revolution. HMT started the operations

with the manufacturing of 25 Hp tractors. Over the years, it has developed tractors ranging from

2575 Hp.

The unit in Hyderabad began to make lamps and lamp making machines in 1973 to cater

to the growing needs of rural. This was followed by producing automatic watches.


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A third watches factory was established in Srinagar to manufacture hand wound watches

for men. In 1975, the company took over the machine tool corporation of Indias unit in Ajmer,

Rajasthan and its name was changed to HMT Limited.

In 1975, a separate international scales network called HMT was set up comprising of

companys own agencies as well as other sales agents in Australia, Europe and America. This

network was to handle the marketing strategy and operations of the company overseas and it also

extended its services to the other leading Indians and overseas engineering companies. Since

then this international arm of the company has set up the turkey project in Algeria, Indonesia,

Iraq, Kenya, Nigeria and Srilanka.

HMTs Products

The main products produced by HMT ltd are

Machine tools,

Watches,

Tractors,

Bearings,

Printing Machinery,

Die Casting Machinery.

The divisions of HMT are described below


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Bangalore

It produces lathes (both CNC and Non CNC), milling/ machining centers, grinding

machines, gear cutting machineries, simple drilling machines, special purpose machines, die

casting and plastic injection moulding.

It also produces refurbishing and retrofitting like heavy duty, turret lathe, multi spindle

drilling machines and fine boring machines.

The other application components include the jigs, fixtures, some radar and transonic

components. It also develops hinomerik control system, Hyderabad.

Hyderabad

It produces the machining centers, CNC, Boring machines, milling machines, die and

mould machining centers, presses and brakes. It also produces special purpose machines like

CNC tube chamfering machines, cam shaft milling machines, filament winding machines,

horizontal and vertical coil winding machines, multi spindle machining centers.


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Kalamessary

It produces CNC lathes and printing machineries.

AjmerIt produces grinders and lathes. It also manufactures some application components like

hydraulic lift mechanism for tractors, valve devices and oil priming pump.

The retrofitting includes center less grinders and double disc grinders.

After establishing two machine factories and a watch factory in Bangalore, the Pinjore

unit was established as the third machine tool factory. Breaking the ground on 2ndmay, 1962,

this factory


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FOUNDARY AND PATTERN SHOP

PATTERN SHOP

Pattern is a replica of final product to be manufactured by casting process. There are different

patterns, which can be classified as :-

1. Solid

2. Loose piece

3. Split pattern

4. Skeleton pattern

Pattern can be made of wood, wax, thermocol, etc. according to users need, the designer

will be providing a drawing from which a 3-d model is made. To make hollow sections in

the casting, cores are used, which is also made in pattern shop. After pattern is made itsdispatched to the foundry for further treatments.

FOUNDARY

1. Sand Making

Sand making is the primary step in foundry for casting process. Sand which is used for

casting process. Sand which is used for moulding are omega sand, black sand, CO2 sand

etc. these above sands are required in the proportion for 1000 kg mix

Ingredients Amount (kg)

US Green US Dry

New sand 300 100

Return sand 700 900

Bentonite 27.5 300

Dextrine 2.5 10

Liquid coal dust 5 -

Saw dust - 10

Furnace oil - 2.5

Water 25 50


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The sand thus prepared is used to make the mould. In order to make complicated

structure, moulding is divided into shape and drag. Pattern made is placed in drag filled

with sand to get a negative impression of similar procedure is applied to the cope.

After that the cores are inserted with the help of core prints and are placed with the helpof chaplets in the drag. Then the cope and drag are assembled together and its sealed. Air

holes and vent holes are provided in the moulding box.

Then the molten metal produced is poured to the mould through the runner and is kept for

solidification for 2-3 days.

Knock out

Its the process of removing core from the casting. As a finishing process the

casting made is machined to required dimensions.

Furnace

Furnace is another important part of foundry. Here metal is melted to do casting

process. There are mainly 2 types of furnace

Main furnace Medium furnace

Power 850 kW 1250 kW

Capacity 3 ton 2.5 ton

Melting rate 1 ton/hr 2.5 ton/hr

The maximum temperature that can be attained is 1500C and the ingredients which areadded to melt metal is pig iron, coke, silicon, chromium, steel scrapes, etc.

While pouring the molten metal to ladle inoculation is done adding calcium silicide in

following proportion:-

1) Wt. of liquid metal * 0.35% for G4 grade.




The slag produced while melting the metal is removed before its used for casting.

Working Instruction for Sintering Heat

1) When plug melts, charge only small scrap (wt. 15 kgs) a piece to build up the level.

Check for the charge hitting for the lining.

2) Do not charge wet or oily scrap. Check water (temperature and pressure) every half hour.

3) When the furnace is fullraise the temperature to 1550C in about 2 hrs by ON & OFF.

4) Hold the temperature for 4 hrs for stabilising the fritting.


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ShotdownPour out plug and molten metal, cover with lid and let the water flow at 50

psi for 18 hrs.

Tin Bronze

Plug - Cyprus block (1 kg)

Charge - copper (100 kgs)

Temperature - 1150C

Shot Blast

Its a process in which the cast metals are blown with small metallic balls known as

Shots. This is done to remove sand or impurities on the surface of the cast metal. Shots are made

of iron.

Fettling

Small level finishing or something of the surface of the cast metal done in foundry

before sending for machinery.

Zircour Hour

Used (as a white paint) to bring a layer between the sand and the molten metal.

How can you make KAIZENS :-

1) Doing normal work by a different method to improve productivity.

2) Identifying waste and eliminating it.

3)

Copying improvements and improving over it.4) Conducting experiments for making small improvements even if they fail.

5) Communicating improvements to others, encouraging their participation.

6) Doing work which couldnt be done due to lack of time.

7) Helping others to do their improvements even if they fail.


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HEAT TREATMENT

Heat treatment is the process to change the properties of a material (metal). By this process we

can increase and decrease the strength of a metal. Processes that are done in heat treatment are:-

Pre heating

Carburizing

Quenching

Annealing

Chromium platting

Blackening

PRE HEATING

Its the process of heating the metal work piece in its primary stage. In this stage we can heat the

metal up to 500oC.

CARBURISING

To increase the strength of a metal we will dip the metal piece to carbon silicate bath for a 9

hours at 900oC. Due to this carbon atom will penetrate at a depth of 1mm.

(No)

Prepare for carburizing

Pre heat at 450 20oC for 1 hour

Carburize at 920 20oC for 1 hour for 0.15 mm depth

Remove cast and check for depth

Is de th as er s ecifications?

Whether next operation

Hardening Annealing

es


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In HMT, machines have the following composition of materials

MATERIAL ANALYSIS

Cast iron 70%

Steel 20%

Nonferrous alloys 5%

Nonmetals (Plastics, rubber, etc.) 5%

CAST IRON - Itsgot the favourable propertiesCastability, Machinability, Wear

Resistant, Damping characteristics,

Dimensional stability, Pressure tight.

STEEL - It can be shaped by forging hot to acquire any shape. It can be machined to any

required finish by various machining process. Heat treatment can be done to

improve machinability. Steel can be alloyed suitably & heat treated by various

heat treatment processes like toughening, nitriding, etc. In this the shaped

component can withstand.

- High service stress

- Corrosion

- Fatigue loading

-

Wear & fitting resistance- Impact

NON FERROUS - Copper based alloys are used --- copper + tin ---- bronze (split nuts

& brushes)

Copper + zinc ---- brass


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PLANNING

This department is the most vital link between the production design and production

department. The production planning department provides necessary facilitates and technical

know-how for the manufacture of the products. Production requires the organized utilization of

the material, resources, money, men and machines. But before starting work actual production,

production planning has to be done in order to anticipate possible difficulties decision in advance

as how to production should be carried in best and economic way. The principle of production

planning lies in the statement first plans your work, and then worksyour plan. The role of

production department is shown below.

The production planning departments at MTK comprises the following sections:-

1. Productions pre-planning planning estimation (PPE & PPP).

2. Production planning ordering FPS-PPO & FPS.

Objective of Planning

In any business organization, production activity must be related to market demand as

indicated by a continuous stream of consumer order. Aggregate planning is carried out in an

economic manner for maximization of product. From the annual operating plan, roll production

plan for 3 months is made of objective of this production planning department is made to ensure

that annual production target is achieved in an economic manner.

Numbering System

A component should be numbered for identification while manufacturing, under the new

system a component is identified by a 9 digits. As the grouping of the assemblies are different for

machine tools & printing machines. Two types of systems are made for component numbering in

MTK & FMT.

FUNCTION AND RESPONSIBILITIES OF PLANNING PERSONNEL

Function and Responsibilities of pre-planning personnel

1) Processing of design documents received for corresponding products.

2) Identification of in house & outside manufacturing items.

3) Preparation of layout for all in house manufacturing items.

4) Implementation of design alteration.


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5) Attending shop problems.

6) Preparation of documents related to the assembly of the product viz. List of assembly

operations, assembly flow chart & segregation of parts list into assembly operation wise.

7) All data entries in computer related to PPP area of concerned products.

8) Verification and approval of material warrant being released by the PPO.

9)

Coordinating all activities related to the concerned product viz. Value engineering, cost

reduction, waste elimination & productivity improvement.

10)Co-ordinate with foundry for the manufacture / alteration of patterns.

Functions and responsibilities of PPE personnel

1) Estimation of standard time for all manufacturing / assembly operations identified in

operation layouts & the assembly list if operations.

2) Data & co-ordination of all activities related to computerization of PPE functions.

3) Authorization of special time in job cards.

Function and responsibilities of monitoring wing:-

Provide all required info to support operations, management and decision making functions into

organizations as detailed below:-

1) Analyse the organizational requirements for information.

2) Design the structures of statement / report & prepare it periodically.

3) Create an appropriate database for the information.

4) Prepare mailing list& ensure the dispatch of statement / report according to the list at the

appropriate time.

5) The information regarding manpower, plant performance, capacity load, production &

sales, stock in trade etc. shall be processed and circulated through weekly, monthly and

yearly statements/ reports.

Function of costing section:-

1) Arranging & finishing data to count department through computer centre about the

standard labour, material & assembly cost of components & assembly groups.

2) Arranging standard labour & material cost for spares, reconditioning machines etc.

3)

Assessment of rectification & rework expenses etc.

STANDARD TIME

Its the required for a qualified worksman under supervision to do a defined amount of

work in the specified quantity following the prescribed method.


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MTK SMALL PARTS

STC 25

The machine has some good features and plenty of power. For example we have a job that

requires the use of a bar puller and need to find the M code or other means to override the

interlock. As it stands now, the turret will not move when the jaws are opened in auto mode. It is

designed for high productivity and accuracy with high transverse rates and reduced non cutting

time.

12 stallion tool turret

Large precision coupling ensure accuracy of indexing and rigidity.

It has slant bed for easy chip flow and heat dissipation

Specifications

Maximum turning dia 250 mm

Maximum turning length 600/1000/1500/2000

Spindle power (100%) 15 kw

Speed range 353500 rpm

Rapid traverse 12m/min

STALLION 200

Latest breed of CNC turning centre offering economical solution for production of high precision

turned parts

30oslant saddle

Programmable tailstock Direct coupled servomotors

Specifications

Swing over bed 460 mm


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Maximum turning length 600 mm

Maximum turning dia 250mm

Main drive power (100%) 7.5 kW

Speed range 1004000 rpm

CNC LATHE ECOCNOCNC 26

Designed to machine complex job profiles with high accuracy and maximum operator fatigue. Its

ideal for small scale industry. Also suitable for medium and not techno-economically justified.

It has got a hydraulic chuck and its run by a program (computer program) in

which Xdefines the diameter of job Ydefines the length of job

Specifications

Height of centers 260 mm

Swing over bed 575 mm

Spindle power (100%) 11 kW

No. of turned stations 8

Control system Siemens/ France

GRINDING MACHINE

These are devices which are used to remove burrs and unevenness on the metal surfaces. The

grinding wheels are made of Aluminium oxide (in HMT). There are different types of grinding

machine which is used to grind different parts of work piece and they are as follows

Cylindrical grinder internal grinder

Centerless grinder Surface grinder

Rotary surface grinder

Rotary surface grindingIt has got a magnetic base. The gears or the jobs are used to grind

surface by grinding wheel and they are fastened to the agnatic


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base.

Table(i) It rotates (which is electrically controlled)

(ii) It also has a to and fro motion (which is hydraulically

controlled).

Internal grinding machineLike other grinding machine, it exceptionally smoothens

the internal surface of a hollow job and has got a

dresser with diamond point so as to redress the grinding

wheel.

MILLING MACHINE

Milling is the machining process of using rotary cutters to remove material from a workpiece

advancing (or feeding) in a direction at an angle with the axis of the tool. Workpiece and cutter

movement are precisely controlled to less than 0.001 in (0.025 mm). Usually by means of

precision ground slides and lead screws an analogous technology. Milling machines may be

manually operated, mechanically automated or digitally automated via computer numerical

control.

Milling machine can perform a vast no. of operations from simple (e.g. slot & key

making, planning, drilling) to complex (e.g. contouring, die sinking). There are usually 3 types of

milling machines at the basic level

1. Horizontal millerhas long arbor

2. Vertical millerhas stub arbor

3. Double head miller

In the miller here in HMT, they have removable tip cutter and usually are in

shapes

All the 3 sides can be used

For step cutting

Arbors are quick release type.


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DRILLING MACHINE

Its a cutiing process that uses a drill bit to cut or enlarge a hole of circular cross- section in solid

material. The drill bit is a rotary cutting tool often multipoint. The bit is pressed against theworkpiece and rotated at 100 to 1000 rpm. This forces the cutting edge against the workpiece,

cutting the chips from what will become the hole being drilled. There are different types of

drilling machines as per requirements, they are as follows

1. Radial drilling machine

2. Sensible drilling machine

3. CNC drilling machine

GEAR MANUFACTURING

There are multiple ways in which a gear blank can be shaped through the cutting and finishing

process.

Hobbing

Its a machining process for making gears, splines and sprockets on a

hobbing machine, which is special type of milling machine. The teeth or

splines are progressively cut into the workpiece by a series of cuts made by

a cutting tool called hob. Oil is used as lubricant.

Shaping

The process of gear shaping uses a toothed disk cutter which reciprocates

in axial rotations. The workpiece (or blank gear) rotates on a second shaft

(spindle). The workpiece is aligned with the cutter and it gradually feeds

into the cutter while rotating. If a two-step process is used, all tooth spaces

are partially cut before finishing.


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HEAVY PARTS

PROFILE MILLING MACHINE

This is a type of milling machine in which heavy parts are cut in special profile and are used

to mill usually the beds, a tail and head stocks and the gear box of normal lathes like NH/N

lathes and slant beds of the CNC lathes. In this the

1) Arbor - In this arbor is perpendicularly with respect to the jobs bed travel.

2) Tool - In this milling machine, it has a profile cutter according to the job and so every

time we have to take the cutter along with the arbor to change the profile of the cutter or

tool. The spacing and the angles between the cutters are changed accordingly. In the

profile cutter there are different types of cutter and of different sizes. This cutter can only

shapes and dos ide milling.3) In this milling is employed, which is milling in going like, doing side milling, surface

milling and all together.The tooth profile and the spacing are custom made according to

the job. The cutters are designed for the parts to the cut.

PLANING MACHINE

It uses linear motion between work piece and single point cutting tool. Analogous to a

shaper but larger & with entre workpiece moving on a table beneath the cutter, instead of a

cutting rod, a ram that moves above a stationary workpiece.

Planning machine uses a quick return mechanism so as to reduce the non-cutting time. The

cutting tool only cuts in one stroke and as the tool undergoes to and fro motion, the return is not

very useful as there is no cutting in return stroke. It also uses a clapper box which raises the

cutting tool in the return stroke. The job moves linearly to & fro and at the same time slightly

sideways after each stroke.

Application

1.

Linear planning2. Generate accurate flat surfaces.

3. Its not as precise as grinding as the surface finish and grind size arent that perfect of

grinding.

4. Its usually and widely used for cutting shots.


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NH/NL LATHES ASSEMBLY

SCRAPPING

Its a man power work done by a tool known as scraper. When a machined job or metalhas dents or minutely uplifted portions, then scrapping is used to flatten or reduce the number of

dents or upliftments on the surface of the job. We use scrapping to increase the extent of

accuracy. We do scrapping for doing the following to the metals job:

1. flatten.

2. for making holes; we use triangular scrapper.

3. to make concave or convex surfaces.

The scraper is made of high speed steel (HSS).

How is scrapping done?

We apply a colored die over a standard surface (which is already flattened or finished or

well surfaced) and then slide it over the surface to be scrapped. The places where the metal to be

scrapped has die is then scrapped off using the scraper. Usually the die is in the form of dots on

unfinished surface. The quality of the scrapped surface is given by counting the number of

colored dots in 1 inch square. The dots are known as bearings (dots per square inch).

For rough surface 2-4 bearings

For finished surface 12-14 bearings

For fine finished surface 24&above bearings

We have a surface plate which has many divided sections of scrapped parts with

different bearings. For the sliding lengths of the lathes for the tools carriage to move is finished

by using it as the standard surface since it is grinded and already finely finished. To alter the

sliding length or the topmost part of the lathe bed we use scraper.

Now, to find whether the sliding surface is flat, convex or concave, we use an instrument

known as spirit meter:

If the motion the spirit meter and the bubble are in the same direction then the surface

is concave. If the motion of the spirit meter and the bubble are in opposite direction then the

surface is convex.


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HEADSTOCK GEARBOX ASSEMBLY

The gears are used in the headstocks gearbox are firstly dipped in boiled water so as to

heat, which will make it easier for slitting it over the shafts, and make its adjust (due to the

expansion) . In lathes we use double role bearing which is specially meant for taking the load on

axial and rotational cutting a high cutting speed of the shaft. The double role bearing is brought

from Germany.

There are many shafts in the headstocks gearbox

1-6 shafts are used for speed selection.

1-9 shafts are used for feed selection.

3

Shaft 1- is main shaft which is the headstock shaft.

Shaft 4 - is the main, powerful and the braking are applied to this shaft.

Shaft 5 - is used for reverse threading and deciding forward and backward.

Shaft 6 - is the shaft with clutch and pulley system.

It has a pump for providing coolant to the shafts which pumps12-13L/min. The shaft 1 needs

upto 3-4L/min of coolant oil for cooling and lubricating of the bearings (the bearings can heat

upto +40C to atmospheric temperature). The shaft 6 has 3 holes for the flow of lubrication and

coolant.

- lubrication of clutch.

- lubrication of shaft.

Brakes are applied by hydraulic pressure and retrieved by compressed springs.

4 2

1


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CNC ASSEMBLY

Ever increasing demands, the need for high accuracy, scrap reduction, etc. have led to the

invention and improvement of CNC machines and undoubtedly termed as one of the milestones

of the century. The accuracy of a micrometer can be acquired in CNC machines.

HMT Kalamassery is famous for its world class CNC turning centers. The earlier models

of machine used Sinumerik and hinumerik control systems and MCUs whereas the new

generation CNC machines of the unit uses Fannuc/ Seimens control system. State of the art

technologies are such as Hydraulic jaws, Ball screws, feedback servomotors, encoders, etc.

The assembly of CNC turning centers can be divided into

Group assembly

Prefinal assembly Final assembly

GROUP ASSEMBLY

This is the place where the assembly of headstock, tailstock, turret- indexing unit, power pack,

turret fixing, etc. is done. HMTK produces following CNCs

STC-20, STC-25, SBCNC-30, SBCNC-40, SBCNC- 60, FMC- gantry loader, STALLION 100

& STALLION 200

The CNC group assembly unit is equipped with various testing apparatus. For ex.

TurretIn its assembly, hydraulic motor & power pack assosciated with it are tested.

HeadstockThe bearings and gears are heated above 90oC for easy assembling.

Hydraulic motorThis reaches the spindle through a worm and worm gear arrangement.

The fluids are controlled by solenoid valves. The grease used is special variant called

isoflex. The headstock is run at different speeds and several parameters are noted and then the

next speed I shifted only when the temperature is controlled and then this is done till maximum

speed is achieved.


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PRE- FINAL ASSEMBLY

Its the section where the assemblies of various components of the CNC lathe like

headstock take place to the lathe bed. Its here that the ball screw alignment is done. Theassemblies of saddle, cross slide, etc. to the bed. Once the various parts are assembled together,

the lathe is taken for final assembly.

FINAL ASSEMBLY

Here the electrical components required for the functioning of the lathe are installed. The

electrical drivers, system and special tools like steady rest, etc. are imported. The stabilizer unit

and conveyer belt are also assembled during this stage. Then the machine is carried for tests.

The various functional groups are explained briefly as follows

Bedmost of the CNCs have slant bed to reduce thermal growth, ease chip removal &

to acquire more load capacity.

HeadstockIn CNCs, we have servomotors which are of variable speed type and so we

dont have gears and pulley systems with shafts. Two types of pulley systems are employed

tapered pulley and keyed pulley. The spindle is loaded on Angular contact bearings which could

take both axial & radial loads. These have hydraulic jaws. The main spindle also has an encoder

which acts as the feedback ot the servomotors, so that required speed is attained. The spindle aremanufactured vibration free for accuracy.

DrivesThe machine contains 3 servomotors 1 for main spindle, 1 for saddle traverse

over the bed and third one for cross slide/turret movement across the saddle. These servomotors

are specially designed for providing relatively constant torque at all speeds.

Saddle It is that part which carries the turret & slides over the bed. The ball screw

mounted on it is powered by servomotors. It also uses braked motor for cross feed. An encoder is

coupled to the ball screw to get feedback on the current position of the tool.

TurretIt is the part that holds the various tools and would position the required tool toperform the cutting. Its radial direction is decided by (X) in the computer and axial direction by

(Z).

The sequence of operation during indexing is as given below-

1. UnclampingThe turret male part unclamps from the curvic coupling(a piston

cylinder arrangement within the turret housing).


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2. RotationThe hydraulic motor is actuated by means of direction control

valves(solenoid valves). This rotation is fed back to the controller by

another encoder. This rotation takes place in the direction of shortest

possible angle.

3. CreepAs the turret reaches the desired angle, an opposite flow is given to motor so

as to reduce the speed of rotation.

4. ClampingOnce the desired position is attained, the turret clamps back into the

coupling and is ready for machining. For operation such as drilling/

milling a special Caxis motor is required & is fitted only on customer

request.

TailstockThe tailstock of a CNC machine is highly advanced. Instead of stationary, a

rotating center is used to reduce heat generation. The tailstock quill is attached to a movable

cylinder and tailstock body acts as a piston. A check valve is provided to avoid the loosening

under pressure. A pressure switch continuously monitors the cylinder pressure and terminates the

operation if any sudden drop is detected.

Lubrication SystemEnsuring sufficient lubrication for the rotating as well as parts are

essential to maintain smooth running for the machine as well as to reduce vibrations, heat

generation and errors. Lubrication is consumed and is not returned to the system . the common

lubrication used in CNC machines is Servo68. The lubrication pipes are made of copper pipes

and flow is controlled by metering cartridges.

Axis Alignment Axis alignment is done on every machine produced at HMT. But in

case of CNC machines, it is of slightly higher importance, because CNCs accuracy is

determined by this process. This is done by giving the tool a predefined feed and then comparing

with the actual position of the tool. The actual position is determined by the means of laser

interferometry.


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g) Ensuring compliance to ISO: 9001 standards of all activities in the section.

PROCEDURE FOR PREVENTIVE MAINTENANCE

Prepare preventive maintenance

Intimate schedule to chief of

manufacturin

Ensure ability of machine

Perform PM as per check list

After completion of PM handover

machine to production

Update PM schedule

Review in the fortnightly maintenance meeting

for process improvement & effectiveness

Record

deviation if any

Review and

reschedule plan

No


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TOOL DESIGN

Tool room is the place where special purpose tools and jigs and fixtures are produced.

Most of the tools are produced as per outside requirements. The different divisions in thisdepartment are in housing tooling and customer tooling. Jigs are used in machining operations

for grinding the tool they assist in mass production. The operation need not know much about the

final shape of the work piece. He just needs to fix the workpiece on the table and guide the tool

at desire spots using jigs. Fixtures are used for fixing the workpiece on the table.

Different tools in tool room.

JIG BORING

It is used to machine tools which must be related with higher degree of accuracy with

reference to datum surface of workpiece within 0.001mm in addition to all kinds of holes

their precise centre be employed for milling flat surface and also as a measuring machine

for inspection and layout operation.

POLYGON DRILLING

In this machine we can make square and hexagonal holes from 3-27 acres flat for each

size holes. There are different cutters. For making square holes, 3 tipped for hexagonal

holes 5 lifted cutters are used. The working mechanism is cam-gear mechanism.

ENGRAVING MACHINE

This is used for engraving / etching letters and numbers in finished parts. After

completing the special notes, working, drawing, etc. are engraved.

THREAD WINDING MACHINE

This finds an extensive application in toll production. To manufacture threads of higher

grades of accuracy. They are employed to grind thread of any form of screws, taps, thread

gauges, worm shafts, different types of cutters, crushers, etc.

TOOL GRINDING MACHINE

Tool an cutter grinding machine are used for shaping and reconditioning of cutting tools

like twists, drills, holes, mills, reamers, taps, gears, etc. this machine also can be used for

parting or slitting of hardened jobs like collets, taps, etc. for parts rubber, bonded

grinding wheels are used.

CARBIDE PLANNING

Carbide tips are braised with tool shanks for manufacturing of special carbide tool. Thecarbide tips are tapped to the required shapes in this machine. The re-shaping of carbide

tipped tool can also be performed in this machine. 1 carbide and 1 diamond wheel is used

for tapping carbide tolls in this machine.


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PRODUCTION PLANNING TOOLS(PPT)

PPT is divided into 2 sections

(i) Tool issuing

(ii) Tool reshaping

Tool used may be cutting or making tool based on requirements. Spirit level gauge,

dies, micrometers, cutting, milling cutter, reamer, bores, drills, bush, etc. are available from PPT.

Flange micrometer to measure stops on the jobs. The level protracted to measure

angle dial indication to check inside of basis.

The bore diameter is checked using inside micrometer. Die are used to cut treads on

flange manually. Plugs, gauges are used to check holes whereas key ways in bores. These are

based on tolerance.

Spline plug gauges to measure splines in shafts and gears. Taper gauge to check

taper inside above. Its male and female type. Snap gauge to check shaft diameter chaises

substituted for dies that is to cut threads on shaft. Splitting saw are used in milling machine to cut

grooves and for parting.

The radial cutters are used to enlarge the bore and angle cutters are used to cut dove

tails with the help of milling machine.

Grinding mandrels are used to hold grinders, Reamers are used to give a smooth

finish to the holes.

Gear hobs are used to cut gears. Center bore is used to deepen the screw. Flat drill is

the drill with flat base and is used to obtain flat base for hole instead of angles. Slip bash used in

jigs and fixtures. The drill may be taper shank (T/s) or straight shank(S/s).

Hole mill is used just before using reamers. It gives depth of 2mm only. Taper

reamers are used to tapper a given hole and expansion reamer to expand a hole (used in

assembly). Extension sleeves are used to increase the length of tool holders. Fixtures and jigs are

used to hold & guide the jobs of the tool. Grinding involves the reshaping & correcting theangles of tools.


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HMT Limited Project Report

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