professional design project · professional design project ... also study of similar product...

Professional Design Project

PDP‐11‐103

Designing and development of cnc cylindrical grinder

MSME name -City -State -Zone -

Atul machine toolsRajkotGujaratWestZone

Designer/Firm-

West

Jitendra pranla l mehtagCity -State -PROJECT CODE

J pRajkotGujarat

Approved cost :Start Date :Completion date :

Rs.75000001-05-201220-03-2014

PHASE 1 – RESEARCH

PHASE 1. PRODUCT DEFINATION PHASE

IDENTIFY THE CUSTOMERS: WHO ARE THEY?

The key to this step is collecting information from customers. There are essentially three methods commonly used: observations, surveys, and focus groups.

As we are in business of manufacturing Cylindrical Grinder for long time, we are in contact of users of CNC Cylindrical Grinder.

We already have the customer using our machines and CNC Cylindrical grinder machines.

We have contacted them and studied their requirement in detail.

As per survival matrix, we are moving towards Improved Product

TTEE

CCHH

NNOO

LLOO

GGYY

OO

RR

PPRR

OODD

UUCC

TT

NNEEWW

IIMMPPRROOVVEEDD

KKNNOOWWNN

KKNNOOWWNN NNEEIIGGHHBBOOUURRIINNGG NNEEWW

MMAARRKKEETT,, CCUUSSTTOOMMEERRSS

SURVIVAL MATERIX

1 4

6 3

8 7

8

2

COMPETETOR BENCHMARKING

Also study of similar product manufacturer in India and Taiwan for generating the specifications of project machine.

Detail of this study is given in excel sheet

After the study, Detail discussion and brainstorming, we have derived the specifications.

CAPACITIES

Max. Dia. Of swing 250 mm

Max. Distance bet. Centres 600mm

Grinding Length 450 mm

Grinding Diameter (max) 200 mm

Maximum Weight Between Centre 60 kg

Work Head Centre Height 150 mm

WHEEL HEAD

Wheel Surface Speed 30 m/s

Grinding Wheel (OD x ID) 400x127 mm

Grinding Wheel Width (Max) 50 mm

Minimum Wheel Size OD 280 mm

R.P.M of wheel spindle (rpm) 1783 rpm

Linear Velocity 30 m/s

Spindle Type Cartridge Type

Spindle Motor 3.7(5.5) KW/HP

WHEEL SLIDE

Guide way Type V NEEDLE SLIDE

Movement Ball screw dia. 32

Slide Stroke 200

Feed Servo Motor torque 4/6 Nm

Rapid Feed Rate (on dia) 10

(Feed back resolution) Minimum Increment/Pulse 0.0001

WORK HEAD

Spindle Morse Taper MT - 4

Spindle rpm 10 - 300 rpm

Motor 1 HP Freq Drive

Work Head Swivel 45 degree

TABLE

Speed 6/10 m/min

Swivel Angle +7 AND -2 Degree

Table Stroke 625 mm

Minimum Increment/Pulse 0.0001

Feed Servo Motor Torque 6/8 Nm

Guide way Type V & flat

Movement Ball screw dia. 32

TAILSTOCK

Sleeve Morse Taper MT - 4

Quill Travel 25

Jitendra MehtaJitendra MehtaJitendra MehtaJitendra Mehta

PROJ. – ATUL MACHINE TOOLS -RAJKOT

DESIGN PROJECT PHASE 2

TITLE OF PROJECT : DESIGN AND DEVELOPMENT

OF

CNC CYLINDRICAL GRINDER

NAME OF COMPANY ATUL MACHINE TOOLS

CO-APPLICANT (DESIGN

EXPERT)

JITENDRA P. MEHTA

We went to great lengths to understand the design problem and to develop its

specifications and requirements. Now our goal is to use this understanding as a basis

for generating concepts that will lead to a quality product.

Concept is an idea that is sufficiently developed to evaluate the physical principles that

govern its behaviour.

We will focus on techniques to help with functional decomposition

Product Assembly Decomposition

After Freezing Specification of the Cylindrical Grinder, Major assembly of machine was decomposed as per table

MAJOR 8 ASSEMBLIES OF CYLINDRICAL GRINDER

1 BASE ASSEMBLY

2 TABLE ASSEMBLY (Z_SLIDE)

3 TABLE_BALL_SCREW (Z_SLIDE)

4 WORK HEAD ASSEMBLY

5 TAIL_STOCK ASSEMBLY

6 WHEEL_HEAD_SLIDE ASSEMBLY (X_SLIDE)

7 WHEEL_HEAD_BALL_SCREW ASSEMBLY

8 WHEEL_HEAD ASSEMBLY



Further to this decomposition of major assembly, are further divided in to sub assemblies to simplify the design process. This finer functional detail leads to a better understanding of the design problem. Breaking down the functions of the design may lead to the realization that there are some already existing components that can provide some of the functionality required.

1 BASE ASSEMBLY

A BASE

B HYDRAULIC POWER PACK

C ELECTRICAL PANEL

D GUARDING

F LEVELING BOLTS

G COOLANT TANK AND ACCESSORIES

2 TABLE ASSEMBLY (Z_SLIDE)

A SLIDE

B Sub-Assembly TABLE_PIVOT_PIN

C Sub-Assembly TOP_PLATE_600

D Sub-Assembly WORK_HEAD_600

E Sub-Assembly Tail Stock_600

F Sub-Assembly TABLE_BS_NUT_BKT

3 TABLE_BALL_SCREW (Z_SLIDE)

A BALL_SCREW

B Sub-Assembly BSB_HOUSING_32

C Sub-Assembly BSB_HOU_FLOT_SIDE

D Sub-Assembly BSB_HOUSING_32

4 WORK HEAD ASSEMBLY

A WORK HEAD

B Sub-Assembly WORK_HEAD_SPINDLE_20

C Sub-Assembly WH_IDELER_SHAFT



5 TAIL_STOCK ASSEMBLY

A TAIL_STOCK

B Sub-Assembly TS_RAM_600

C Sub-Assembly T_S_PINION_SHAFT

6 WHEEL_HEAD_SLIDE ASSEMBLY (X_SLIDE)

A Sub-Assembly G_W_H_BTM_SLIDE

B Sub-Assembly G_W_H_TOP_SLIDE

C Sub-Assembly GWH_MOTOR_STAND

D Sub-Assembly MOTOR_STAND_SCREW

7 WHEEL_HEAD_BALL_SCREW ASSEMBLY

A BALLSCREW

B Sub-Assembly BSB_HOUSING_32

C Sub-Assembly PAD_GWH_SLIDE_FLOT

8 WHEEL_HEAD ASSEMBLY

A HEAD

B Sub-Assembly GRINDING_SPINDLE

C Sub-Assembly GRINDING_WHEEL

Benchmarking is a good practice because many hundreds of engineering hours have

been spent developing the features of existing products, and to ignore this work is

foolish.

We have benchmarked sub assemblies from Existing manufacturers from India and Taiwan

for different assemblies and studies their concept and system in detail.

My experience in design and manufacturing of Grinding Machines and experience of

entrepreneur of making similar conventional machine, makes Concept creation very

comfortable.



TYPE OF GUIDE WAYS FOR TABLE

Guideways are machine component used to guide slides (saddle, table, etc) and to

bear the loads applied on them.

They are devised to constrain five degrees of freedom of the slide and allowing only

the linear motion along the machine axis.

To design these guideways for modern machine tools, a set of requirements should

be met as follows: high positioning accuracy, high load capacity and stiffness,

minimum friction and wear, motion without stick-slip, high damping of vibrations,

long service life and low power-consuming.

The types of guideways most used on machine tools are the following: plain, rolling,

hydrostatic, aerostatic and combined guideways (one type in combination with another).

Normally antifriction guide ways are used in recent technology, but for grinding machine

rigidity is very important when we consider the Indian customers. In Indian condition, in

put to the machine is not as per requirement.

We have decided to go with plastics-coated slideways plain slide with V and Flat.

These slideways are constructed with thin-film PTFE (Polytetrafluorethylene) bearings pads The materials used for the construction of plain slideways should have the following properties: a) A low coefficient of friction, preferably even under dry friction conditions; b) A coefficient of friction that does not decrease with increasing velocity and that does not vary markedly with lubrication conditions; c) A low rate of wear and a high resistance to abrasion; d) Good dimensional stability and damping behaviour with adequate stiffness; e) Reasonable cost, simplicity of application and good machining properties; f) Good chemical stability and good compatibility with lubricating oils and cutting fluids.

Drive to Slide with Ball Screw and Servo Motor



TYPE OF GUIDE WAYS FOR WHEEL HEAD For guide ways of head, posinitional accuracy is very important, We have decided for antifriction slide. But again to achieve rigidity, we have decided to go with V roller slide Also we have bench marked with other Manufacturer Drive to Slide with Ball Screw and Servo Motor RAPID AND FEED TRAVEL OF BOTH SLIDES We have bench marked from other Manufacturer For Table Slide – 8 mt/Min For Cross Slide – 12 mt/Min WORK HEAD DRIVE To make our machine competitive in the market we have decided to go with A C motor and Frequency variable drive for same. Work Head Drive RPM Varies from 30 to 300 TYPE OF GRINDING WHEEL SPINDLE Spindle manufacturing is very specialised and accurate process. Instead of spending time and money, we have decided to outsource it. Now a day’s good manufacturers are in market. Also recent era is grinding spindle with Antifriction bearing WHEEL DRESSING ARRANGEMENT For wheel dressing, rigid and fixed bracket is to be design TYPE OF BALL SCREWS AND MOUNTING ARRANGEMENT According to accuracy requirement, and length of ball screw, we have decided to go with both end fix for table and One fix and One Floating for Cross Slide TAILSTOCK RAM MOVEMENT Normally tailstock Ram is spring loaded manual but we are planning for Hydraulic movement.



LUBRICATION POSSIBILITIES We will go with Centralised Automatic Lubrication system CNC SYSTEM REQUIREMENTS For CNC System, option available in India is Fanuc and Siemens. Discussion is in process with both.

WORK HEAD

600 mm

TAIL

STOCK

SLIDE

BASE



After creating concept, Design work starts with some standard data and formula used from CMTI Machine tool design data book

Unit Formula

Diameter of Wheel D mm 350

Peripheral Speed of Wheel v m/sec ̟*Dn/1000*60 32mt/Min

Wheel Revolution per Minute n RPM 1740

Diameter of Work piece Dw mm 50

Work piece rev per Minute nw RPM 200

Peripheral work Speed Vw m/min ̟*Dw*nw/1000 3.14

Depth of Grind Traverse grinding t mm/pass 0.025

Table traverse feed rate ft mm/min 2000

Width of cut Plunge Grinding b mm 40

Plunge in feed rate per work revolution S mm/Rev .01

Plunge in feed rate per minute fp mm/min S*nw 2

Metal Removal Rate Q

Traverse Grinding Q1 Cm³/min ̟*Dw*t*ft/1000 7.85

Plunge Grinding Q2 cm³/min ̟*Dw*b*fp/1000 12.56

Unit Power U Kw/.cm³/min From Data Book 0.85

Power at Spindle N Kw U*Q 4.003

Efficiency of Transmission E % 90

Power of Motor Nel Kw N/E 4.447

Tangential Cutting Force Pz Kgf 102*N/v

Torque at Spindle Ts Kgf.m 975N/n 2.22413

DESIGN OF BED Bed is designed with One V and One Flat For each contacting surface, Maximum pressure calculated and compared with maximum permissible value of pressure as obtained from experimental investigation is give in CMTI Machine tool design data book. For cast iron slide ways of grinding machine is .005 to .008 Kgf/mm2 Base on this data Shape and Size of V and flat is decided

PHASE 3 – DRAWINGS

PHASE 2 – CONCEPTS

PHASE 4 – PROTOTOTYPE

BED AND TABLE

FINAL PRODUCT

professional design project · professional design project ... also study of similar product...

Documents