ASSEMBLY CHECK LIST IN PRESS TOOL

01 After machining of the Tool components, quality was checked and dimension was inspected as per the drawing.

02 All parts were cleaned and lubricated for Assembly.

03 The mating surface of all was oil stoned for assembly.

04 Before assembling the tool, the fit of mating parts were checked individually.

05 All parts were numbered for easy assembly.

06 The guide pillars and guide bushes were assembled to the housing and tightened.

07 Blanking Die and Piercing Punches were inserted into the Punch Support Plate and were positioned into the top plate by means of screws.

08 The blanking Punch along with the strip guides and stripper plates was clamped to the bottom housing. All the screws were tightened to the respective places.

09 Clearance setting and sliding movement of the punches was confirmed.

10 The movement of punches and guide pillars were assured .It was matched with their respective inserts.

ASSEMBLY CHECK LIST IN PRESS TOOL

01 After machining of the Tool components, quality was checked and dimension was inspected as per the drawing.

02 All parts were cleaned and lubricated for Assembly.

03 The mating surface of all was oil stoned for assembly.

04 Before assembling the tool, the fit of mating parts were checked individually.

05 All parts were numbered for easy assembly.

06 The guide pillars and guide bushes were assembled to the housing and tightened.

07 Blanking Die and Piercing Punches were inserted into the Punch Support Plate and were positioned into the top plate by means of screws.

08 The blanking Punch along with the strip guides and stripper plates was clamped to the bottom housing. All the screws were tightened to the respective places.

09 Clearance setting and sliding movement of the punches was confirmed.

10 The movement of punches and guide pillars were assured .It was matched with their respective inserts.

MACHINE OPERATIONS ARE CARRIED OUT FOR TOOL

1. Pre-tooling

Raw material is cut to overall profile considering machining allowances. This operation is carried out generally by sawing and flame cutting.

2. Surface Grinding

After pre-tooling cleaning all the sides and maintaining right angles, this block is further smooth machined on grinding machine.

3. Conventional Machining

According to drawing and process sheet the raw material is rough machined to the geometric features and size of the part by providing sufficient allowance for finishing. Conventional machining is generally carried out by Lathe, Milling and Shaping machines.

4. CNC Machining

Features such as Pockets, Profiles, which requires close tolerances are machined in this stage.

5. Stage Inspection

After each operation stage inspection is carried out to check the required profiles are having geometric accuracy or not.

6. Bench Work

Drilling, Tapping is done using drilling machines. Finishing, corner radius, cavity profiles are done at this stage.

7. Heat treatment

The cavity block is now quenched and tempered to required hardness of 46 to 48 HRC.

8. Sparking and Wire cutting

Features which cannot be machined by conventional machine are done by this process.

9. FinishingThis is the last stage in manufacturing done by Grinding, Polishing or Lapping as required.

10. Final Inspection (CMM)

Co-ordinate measuring machine is used to check complex profiles which require close tolerance. Detail of CMM and tolerances used for manufacture tool components are detailed.

MACHINE OPERATIONS ARE CARRIED OUT FOR TOOL

1. Pre-tooling

Raw material is cut to overall profile considering machining allowances. This operation is carried out generally by sawing and flame cutting.

2. Surface Grinding

After pre-tooling cleaning all the sides and maintaining right angles, this block is further smooth machined on grinding machine.

3. Conventional Machining

According to drawing and process sheet the raw material is rough machined to the geometric features and size of the part by providing sufficient allowance for finishing. Conventional machining is generally carried out by Lathe, Milling and Shaping machines.

4. CNC Machining

Features such as Pockets, Profiles, which requires close tolerances are machined in this stage.

5. Stage Inspection

After each operation stage inspection is carried out to check the required profiles are having geometric accuracy or not.

6. Bench Work

Drilling, Tapping is done using drilling machines. Finishing, corner radius, cavity profiles are done at this stage.

7. Heat treatment

The cavity block is now quenched and tempered to required hardness of 46 to 48 HRC.

8. Sparking and Wire cutting

Features which cannot be machined by conventional machine are done by this process.

9. FinishingThis is the last stage in manufacturing done by Grinding, Polishing or Lapping as required.

10. Final Inspection (CMM)

Co-ordinate measuring machine is used to check complex profiles which require close tolerance. Detail of CMM and tolerances used for manufacture tool components are detailed.

MANUFACTURE OF PRESS TOOL

Simple forms can be machined easily on milling machines and ground on the tool and a cutter or profile grinder .Punches and dies are marked, milled or filed, hardened and ground or polished. Spherical end mill can be used to obtain the desired corner radii in the in non-cylindrical dies and punches. These radii and milled surfaces of the dies are finished manually using tiny grinding wheels of a variety of shapes. Human skill becomes an important in finishing less accessible crevices.

Irregular forms can be finished by spark erosion machining. The electrode is a male mirror image of the die to be eroded. It is necessary to use a number of electrodes with only the finishing electrode being an exact mirror male replica of the die. Roughing and semi finishing electrodes are smaller. As the electrodes wear considerably during erosion, worn out electrodes can be used for roughing.

Bending tools which are stressed less than 80 N /Square mm can be of cheaper ,easier to machine case hardening steels .Bending and forming tools need not be as hard as the cutting tools. Punches and dies can be hardened and tempered to HRC 55-58.
The manufacture of the tooling is carried out in the tool room department, Prabha Dytek Ltd. The detailed process plan for manufacturing of tools is as follows.

MANUFACTURING PROCESS

1. After receiving the design from the design department, planning department will decides the work movement of the tool.
2. As per bill of material raw material will be procured according to planning date.
3. As per detail drawing all the raw material will be pre machined.
4. As per planning date each job will be sent to respective of their operations. Ex: Round items----turning, Flat items----milling.
5. As per detail drawing spotting work will be carried out.
6. Flat items sent to maintain right angle grinding for spotting reference.
7. According to drawing all drilling work has to be done except dowel holes in soft material (Dowel holes to be transferred after suiting).
8. Punch and dies to be prepared for heat treatment.
9. After heat treatment all dowel holes to be checked for dowel pass if the dowel is not entering easily then lapping is to be done and sent to grinding.
10. Die set was prepared first.
11. All punches and dies are mounted on their respective places.
12. After mounting the punches and dies alignment will be carried out in any one of the following three methods
-Using blue.
-Using shim.
-Using light.
13. After accurate alignment tool will be sent for trials.

PROCESS CAPABILITY

The process capability (or machine tool accuracy study) of a machine or tool or manufacturing process can be defined as the minimum tolerance to which machine can possibly be expected to work and produce no defectives under the specified conditions.

OBJECTIVES OF PROCESS CAPABILITY ANALYSIS

Process capability analysis is a vital part of an overall quality improvement program.
Process capability analysis consists of:

• Measuring the process capability to find out whether the process is inherently capable of meeting the specified tolerance limits.
• Discovering why a process ‘capable’ is failing to meet specifications.
• Assist product developers / designers in selecting or modifying a process.
• Assist in establishing an interval between sampling for process controls.
• Reducing the variability in manufacturing process.
  

Thus process capability is a technique that application in many segments of product life cycle, including product and process design, and production or manufacturing.

MANUFACTURE OF PRESS TOOL

Simple forms can be machined easily on milling machines and ground on the tool and a cutter or profile grinder .Punches and dies are marked, milled or filed, hardened and ground or polished. Spherical end mill can be used to obtain the desired corner radii in the in non-cylindrical dies and punches. These radii and milled surfaces of the dies are finished manually using tiny grinding wheels of a variety of shapes. Human skill becomes an important in finishing less accessible crevices.

Irregular forms can be finished by spark erosion machining. The electrode is a male mirror image of the die to be eroded. It is necessary to use a number of electrodes with only the finishing electrode being an exact mirror male replica of the die. Roughing and semi finishing electrodes are smaller. As the electrodes wear considerably during erosion, worn out electrodes can be used for roughing.

Bending tools which are stressed less than 80 N /Square mm can be of cheaper ,easier to machine case hardening steels .Bending and forming tools need not be as hard as the cutting tools. Punches and dies can be hardened and tempered to HRC 55-58.
The manufacture of the tooling is carried out in the tool room department, Prabha Dytek Ltd. The detailed process plan for manufacturing of tools is as follows.

MANUFACTURING PROCESS

1. After receiving the design from the design department, planning department will decides the work movement of the tool.
2. As per bill of material raw material will be procured according to planning date.
3. As per detail drawing all the raw material will be pre machined.
4. As per planning date each job will be sent to respective of their operations. Ex: Round items----turning, Flat items----milling.
5. As per detail drawing spotting work will be carried out.
6. Flat items sent to maintain right angle grinding for spotting reference.
7. According to drawing all drilling work has to be done except dowel holes in soft material (Dowel holes to be transferred after suiting).
8. Punch and dies to be prepared for heat treatment.
9. After heat treatment all dowel holes to be checked for dowel pass if the dowel is not entering easily then lapping is to be done and sent to grinding.
10. Die set was prepared first.
11. All punches and dies are mounted on their respective places.
12. After mounting the punches and dies alignment will be carried out in any one of the following three methods
-Using blue.
-Using shim.
-Using light.
13. After accurate alignment tool will be sent for trials.

PROCESS CAPABILITY

The process capability (or machine tool accuracy study) of a machine or tool or manufacturing process can be defined as the minimum tolerance to which machine can possibly be expected to work and produce no defectives under the specified conditions.

OBJECTIVES OF PROCESS CAPABILITY ANALYSIS

Process capability analysis is a vital part of an overall quality improvement program.
Process capability analysis consists of:

• Measuring the process capability to find out whether the process is inherently capable of meeting the specified tolerance limits.
• Discovering why a process ‘capable’ is failing to meet specifications.
• Assist product developers / designers in selecting or modifying a process.
• Assist in establishing an interval between sampling for process controls.
• Reducing the variability in manufacturing process.
  

Thus process capability is a technique that application in many segments of product life cycle, including product and process design, and production or manufacturing.

Design considerations for draw dies

Before beginning the designs make sure that method plan (deciding all the operation that has to be performed in order get finished component) is kept ready in all aspects.

1. Decide the blank holder shape
2. Decide for the beads at appropriate places for deeper draws
3. For shallow draws provide some locations for trim dies in non working area

4. Calculate the draw force required
5. Calculate the cushion force required for blank holder as it plays an important role in flow of material
6. Select the suitable press required either mechanical or hydraulic as specified by the customer
7. Select the cushion area in such a way that it balances the blank holder
8. Select for clamping slots required from the press layout
9. Material for draw punch & die is HcHcr hardened to 56-58 HRC.
10. Provide wear plates for draw punch & blank holder sliding at appropriate position so that it balances
11. Provide guide pillars on blank holder & guide bush on draw die. So that there will be initial alignment between the draw die & blank holder.

12. Provide heel guides with wear plates on draw die only if customer insists or other wise it is not necessary
13. Decide for blank holder travel (blank holder surface should be always above the punch surface by 5-10 mm)
14. Provide shoulder bolt at appropriate position & to be fastened to bottom punch/base plate so that in controls the travel of blank holder.

Design considerations for draw dies

Before beginning the designs make sure that method plan (deciding all the operation that has to be performed in order get finished component) is kept ready in all aspects.

1. Decide the blank holder shape
2. Decide for the beads at appropriate places for deeper draws
3. For shallow draws provide some locations for trim dies in non working area

4. Calculate the draw force required
5. Calculate the cushion force required for blank holder as it plays an important role in flow of material
6. Select the suitable press required either mechanical or hydraulic as specified by the customer
7. Select the cushion area in such a way that it balances the blank holder
8. Select for clamping slots required from the press layout
9. Material for draw punch & die is HcHcr hardened to 56-58 HRC.
10. Provide wear plates for draw punch & blank holder sliding at appropriate position so that it balances
11. Provide guide pillars on blank holder & guide bush on draw die. So that there will be initial alignment between the draw die & blank holder.

12. Provide heel guides with wear plates on draw die only if customer insists or other wise it is not necessary
13. Decide for blank holder travel (blank holder surface should be always above the punch surface by 5-10 mm)
14. Provide shoulder bolt at appropriate position & to be fastened to bottom punch/base plate so that in controls the travel of blank holder.

AUTOFORM

Auto-form is an extremely popular, class-leading modular suite of Simulation software used across a broad spectrum of industries. It’s open & flexible simulation solutions provide a common platform for fast, efficient & cost-effective product development, from design concept to final-stage & performance validation.

Auto Form is a process simulation tool for the sheet-metal sector that plays a pivotal role in achieving the following.

· Sheet blanking

· Hydro forming

· Sheet forming Deep Draw, Shallow Draw.

Auto form is used by industries for the following:

· Draw ratio optimization

· Prediction of thinning

· Optimization of blank holder force.

· Optimization of punch velocity

· Reduction of thinning regions.

· To incorporate Bauschinger effect for accurate spring back calculations.

· Improving the accuracy and shortening the product development time.

· Optimization of the punch load.

· Design cycles can be optimized for number of stages of forming.

AUTOFORM

Auto-form is an extremely popular, class-leading modular suite of Simulation software used across a broad spectrum of industries. It’s open & flexible simulation solutions provide a common platform for fast, efficient & cost-effective product development, from design concept to final-stage & performance validation.

Auto Form is a process simulation tool for the sheet-metal sector that plays a pivotal role in achieving the following.

· Sheet blanking

· Hydro forming

· Sheet forming Deep Draw, Shallow Draw.

Auto form is used by industries for the following:

· Draw ratio optimization

· Prediction of thinning

· Optimization of blank holder force.

· Optimization of punch velocity

· Reduction of thinning regions.

· To incorporate Bauschinger effect for accurate spring back calculations.

· Improving the accuracy and shortening the product development time.

· Optimization of the punch load.

· Design cycles can be optimized for number of stages of forming.

MATERIAL USED FOR DIE MAKING

In the die making practice a large variety of materials are available for use. These include many different kinds of steels, castings of both ferrous and non-ferrous metals, and even non metallic materials.

Carbon Die Steel-This steel may contain 0.90-1.15 Carbon, 0.20-0.45 Manganese, 0.16 Silicon, 0.025 Phosphorus, and 0.025 Sulphur.

Carbon Die Block Steel- 0.55-0.65 carbon, 0.50-0.70 manganese, 1.25-1.75 nickel, 0.60-1.10 chromium.

Tungsten Oil Hardening Steel- This steel contains about 1.20 carbon, 1.75 tungsten, and 0.25 manganese.

High –Alloy Oil-Hardening Steel- This class of non deforming steel contains about 2.15 carbons, 12.00 chromium, and manganese content of about 0.35.Vanadium, tungsten, and nickel are other elements which may be added to this class of steel.

Manganese Air Hardening Steel- A typical composition contains 0.90 carbon, 2.5 manganese, 1.5 chromium, 1.00 molybdenum, and 0.30 silicon.

Chromium Air Hardening Steel- This steel usually contains about 1.00 carbon, 5.00 chromium, 1.00 molybdenum, 0.50 manganese, 0.25 silicon, and in some cases 0.50 vanadium is added.

High Alloy Air-Hardening Steels- These steels like the high alloy oil-hardening type, have about 12.00 chromium. The carbon content varies from 1.00 to 2.15, manganese 0.35, silicon 0.35, molybdenum 0.80, and in some cases 0.50 vanadium.

Material for producing low cost dies.

In the manufacture of air craft and various other products their have been important developments in making die other than steel or cast steel, which meet practice requirements and yet make it possible to greatly reduce the die cost. This is particularly true where sheets, such as aluminium and magnesium, must be formed or drawn but in quantities that are not large enough to require as durable and expensive a material as steel, for example. These low cost die may be made of non-ferrous alloys such as Kirksite and Cerrobend and non-metallic material may also be used such as Masonite, plastics, Bakelite, dancified wood, and rubber. These die are utilized for drawing or forming in the usual manner and also in conjunction with stretch-forming process. The low cost dies referred to are extensively used for medium

MATERIAL USED FOR DIE MAKING

In the die making practice a large variety of materials are available for use. These include many different kinds of steels, castings of both ferrous and non-ferrous metals, and even non metallic materials.

Carbon Die Steel-This steel may contain 0.90-1.15 Carbon, 0.20-0.45 Manganese, 0.16 Silicon, 0.025 Phosphorus, and 0.025 Sulphur.

Carbon Die Block Steel- 0.55-0.65 carbon, 0.50-0.70 manganese, 1.25-1.75 nickel, 0.60-1.10 chromium.

Tungsten Oil Hardening Steel- This steel contains about 1.20 carbon, 1.75 tungsten, and 0.25 manganese.

High –Alloy Oil-Hardening Steel- This class of non deforming steel contains about 2.15 carbons, 12.00 chromium, and manganese content of about 0.35.Vanadium, tungsten, and nickel are other elements which may be added to this class of steel.

Manganese Air Hardening Steel- A typical composition contains 0.90 carbon, 2.5 manganese, 1.5 chromium, 1.00 molybdenum, and 0.30 silicon.

Chromium Air Hardening Steel- This steel usually contains about 1.00 carbon, 5.00 chromium, 1.00 molybdenum, 0.50 manganese, 0.25 silicon, and in some cases 0.50 vanadium is added.

High Alloy Air-Hardening Steels- These steels like the high alloy oil-hardening type, have about 12.00 chromium. The carbon content varies from 1.00 to 2.15, manganese 0.35, silicon 0.35, molybdenum 0.80, and in some cases 0.50 vanadium.

Material for producing low cost dies.

In the manufacture of air craft and various other products their have been important developments in making die other than steel or cast steel, which meet practice requirements and yet make it possible to greatly reduce the die cost. This is particularly true where sheets, such as aluminium and magnesium, must be formed or drawn but in quantities that are not large enough to require as durable and expensive a material as steel, for example. These low cost die may be made of non-ferrous alloys such as Kirksite and Cerrobend and non-metallic material may also be used such as Masonite, plastics, Bakelite, dancified wood, and rubber. These die are utilized for drawing or forming in the usual manner and also in conjunction with stretch-forming process. The low cost dies referred to are extensively used for medium

TOOL STEELS

Tool steel is specified for numerous die components and it may be well to discuss briefly the most commonly used types. they are:

1. Water hardening tool steel.

2. Oil hardening tool steel.

3. Air hardening tool steel.

4. High carbon high chromium tool steel.

5. High speed steel.

6. Shock resisting tool steel.

7. Hot work die steel.

1. Water hardening tool steel

As its name indicates water hardening tool steel is hardened by quenching it in water after it has first been heated to proper hardening temperature. it is employed for parts which can be ground after hardening. water hardening tool steel is subject to distortion in hardening process and it should not be specified for parts with internal contours that must remain accurate and which cannot be ground after hardening.

2. Oil hardening tool steel.

oil hardening tool steel contains chromium and it is quenched in oil in the hardening process.warpage or distortion is much less than for corresponding grades of water hardening steels. when accurate surfaces cannot be ground after hardening, and anticipated production rates are average, oil hardening tool steel should be specified. the abbreviation is O.H.T.S.

3. Air hardening tool steel.

air hardening tool steel need not be quenched in either oil or water for hardening to occur. after heating beyond the critical range, it is simply exposed in air until cool. air hardening tool steels have minimum warpage and this is combined with greater toughness and wear resistance than corresponding grades of oil or water hardening tool steels.

4. High carbon high chromium tool steel.

high carbon high chromium tool steel, have about the same properties as air hardening steels except that they posses a greater degree of resistance to wear. high carbon high chromium tool steel should be specified for die parts when long production runs are anticipated.

5. High speed steel.

The outstanding quality of high speed steel is its toughness, combined with a high degree of wear resistance. it should be specified for weak die parts such as frail inserts, small diameter punches, and the like another excellent application is in dies for cold working, coining and upsetting of metal.

6. Shock resisting tool steel.

shock resisting tool steel contain a smaller amount of carbon and therefore it is tougher than other types. it is employed for heavy cutting and forming operations where steels with higher carbon content would be subject to breakage.

7. Hot work die steel.

These steels are employed in dies designed for forming hot materials because they posses high resistance to softening under heat.

TYPE OF STEEL	Non deforming properties	Safety in hardening	Toughness	Wear resistance	machinability	Resistance to softening under heat
water hardening tool steel	POOR	FAIR	GOOD	FAIR	BEST	POOR
oil hardening tool steel	GOOD	GOOD	FAIR	FAIR	GOOD	POOR
air hardening tool steel	BEST	BEST	FAIR	GOOD	FAIR	FAIR
high carbon high chromium tool steel	BEST	BEST	POOR	GOOD	POOR	FAIR
high speed steel	GOOD	BEST	BEST	GOOD	FAIR	GOOD
shock resisting tool steel	FAIR	GOOD	BEST	FAIR	FAIR	FAIR
hot work die steel	BEST	BEST	BEST	FAIR	FAIR	GOOD