Overview Principles of

PRESS TOOLSand

PRESSESBy

M. J. TAMBVEAssistant Director (Tool Design)

IDEMI

Chapter 1

Tool Design Methods

Chapter 1

Tool Design Methods

INTRODUCTION

The Tool Designer must The Tool Designer must provide drawings of a tool or set of tools to produce the work piece.able to visualize exactly how the work piece is to be made. Know manufacturing procedures.Have knowledge of standards and procedures.methods used by the plant in manufacturing.inventive and original.understand how tools perform their function.a mastery of drafting techniques is as essential.

The word “Tooling” refers to the Hardware necessary to produce a Particular Product

Types of ToolingTypes of Tooling

Cutting tools, such as drills, reamers, milling cutters, broaches, and taps

Jigs and fixtures of guiding the tool and holding the work piece

Gauges and measuring instruments

Sheet-metal press working dies for all types of sheet-metal fabrication

Dies for plastic molding, die casting, permanent molding, and investment casting

Forging dies for hot and cold forging, upsetting, extrusion and cold finishing.

Tool DesignTool Design

The Design Procedure

Statement of the Problem

The Needs Analysis

Tentative Design Solutions

The Finished Design

The Needs AnalysisThe Needs Analysis1)Will the tool be used by skilled or unskilled operators?2)How many parts can be held in the tool?3)What are the hole-location tolerances on the part?4)How should the part nest in the jig to maintain accuracy in hole location?5)Will the forces from the clamping device affect hold location?6)Are pneumatic lines located in the area?7)What are the measurements on the T slots of the machine table?8)Will operating handles of the machine strike the tool?9)Will the location of the tool prevent removal of cutters for resharpening?10)Does the operator need more than one size of wrench or loose handle?11)Is there any obstruction that may hinder the loading and unloading of the fixture?12)Are there variations in shape of the parts?

The Needs AnalysisThe Needs Analysis13) What previous operations have been done on the part?14) If coolant is used, what provisions must be made for coolant passage?15) What provisions should made to prevent accumulation of chips? 16) Surface on the work piece is best suited to locate in relation to the

major reference plane on the machine?17) Are locating points easily visible to the operator?18) Will burrs interfere with unloading?19) Are clamps well out of the way during loading and unloading?20) If a cutting fluid is used, will knurled knobs make the operator’s

fingers sore?21) Can the tool be made with the available components and facilities?22) Is the cutting force heavy or light in this operation?23) Is the cutting force directed toward the solid part of the fixture?24) Is the work supported directly under the clamping points?25) Will the clamping force bend the base plate and cause inaccurate

work?

Chapter 2

DRAFTING AND DESIGN TECHNIQUES

IN TOOLING DRAWINGS

Chapter 2

DRAFTING AND DESIGN TECHNIQUES

IN TOOLING DRAWINGS

DRAFTING AND DESIGN TECHNIQUES IN TOOLING

DRAWINGS Drafting PracticeDrafting Practice

The following list of drafting rules generally applies to tool drawings and is intended as a guide to help maintain uniformity

1)   All lines must be dark enough to produce a clear and sharp print

2)  All drawings should be on standard size that will allow the resulting prints to fold to standard A4 size.

3)  All drawings should have a border line drawn 5 or 10 mm from each side of the paper, depending upon the size of the drawing.

4)  The material and title block should be located in the lower right-hand corner of the drawing.

5)  All dimensions should be expressed in mm, with the mm sign omitted.

6) Full-scale drawings should be used whenever possible. Otherwise, use half or as per IS: 696 standard.

7)  Drawing and dimensioning must help the person who will use the drawing to make the item in the tool room. The toolmaker should not have to make calculations before he can begin producing the tool.

8)   Only as many views as necessary to show all required detail should be given.

Drafting PracticeDrafting Practice

9) Use uppercase engineering lettering (3 mm high) throughout the drawing.

10)  A name is always assigned to each tool and placed in the title block. The name usually is the tool name plus the name of the part as noted on the part drawing. For example, if the name in the title block of a part drawing is ‘Horizontal actuating rod’ the correct title of the drill jig is ‘Drill jig-horizontal actuating rod’.

11) Only critical dimensions, overall dimensions, and location dimensions should be shown on tool drawings Dimensions of individual pieces can be indicated in the bill of materials and need not appear on the drawing.

12) Standard purchased tool components need not be dimensioned. These include die sets, screws, dowels, springs, knobs and tooling specialty items. Dimensions are not necessary because the components come ready-made and are identified in the material list by number.

13)  Standard purchased tool components that are to be altered by the toolmaker should have the altered portion dimensioned.

14)   Special tooling components that have been standardized by a particular company do not need dimensions.

15)    Dimensions that can be determined by or calculated from, dimensions on the part print need not be shown on the tool drawing. Examples would be the center of the nest, cutting edges on a punch, die clearance, etc.

DRAFTING AND DESIGN TECHNIQUES IN TOOLING

DRAWINGS

Drawing LayoutDrawing Layout

•The Tool assembly drawing is drawn on one sheet with different views and material list also shown.

•Each component or groups components are detailed completely on a separate sheet.

DRAFTING AND DESIGN TECHNIQUES IN

TOOLING DRAWINGS

Information BlocksInformation Blocks

DRAFTING AND DESIGN TECHNIQUES IN

TOOLING DRAWINGS

Information BlocksInformation Blocks

DRAFTING AND DESIGN TECHNIQUES IN

TOOLING DRAWINGS

Information BlocksInformation Blocks

DRAFTING AND DESIGN TECHNIQUES IN

TOOLING DRAWINGS Standard SheetStandard Sheet

DRAFTING AND DESIGN TECHNIQUES IN TOOLING DRAWINGS

Jig DesignJig Design