Machine tools and their applications Unit – I Machine tools and their applications

Syllabus Drilling machine: Types of drills and operations. Twist drill geometry, Types of drilling machine, Tool holder, Calculation of machining time for Drilling Process Milling machine: Types of milling machines, Cutter-types and geometry and their applications. Universal dividing head, Methods of Indexing: Simple, Compound, Differential. Numericals based on indexing. Calculation of machining time for Milling processes(Numericals) Broaching: Introduction to broaching, Broach tool geometry, Types of broaching machines and operations. Planer and Boring Machines(Introduction and types)

Unit In Sem Exam Remark End Sem Exam 1 10 TH+NU 7 2 3 8 4 16 5 6

University Questions Explain with sketch types of broaches Explain tool geometry features of broach and values for HSS broach for finishing hole List types of broaching machines and sketch any continuous broaching machine Draw sketch of planing machine and label

University Questions List types of planer machine and their features with application Explain boring operation and need for a boring machine Draw sketch of horizontal boring machine and label List types of boring machines and their applications

Broaching Machines

Broaching Moves a multiple tooth cutting tool linearly relative to work in direction of tool axis Fig. The broaching operation When the broach is fed in a straight line , metal is cut in several successive layers

Broaching Advantages: Good surface finish Close tolerances Variety of work shapes possible Cutting tool called a broach Owing to complicated and often custom‑shaped geometry, tooling is expensive

Broach Geometry Figure (a) Cutting action of a broach showing various features. (b) Terminology for a broach.

Geometry of broaching teeth and their cutting edges Small in-built chip breakers are alternately provided on the roughing teeth to break up the wide curling chips

Chipbreaker Features on Broaches Figure Chip breaker features on (a) a flat broach and (b) a round broach.

Pull-Types Internal Broach Figure Terminology for a pull-type internal broach used for enlarging long holes

Sawing Operations Figure Examples of various sawing operations.

Saw Teeth Figure (a) Terminology for saw teeth. (b) Types of tooth sets on saw teeth staggered to provide clearance for the saw blade to prevent binding during sawing. Figure High-speed-steel teeth welded on a steel blade Carbide inserts brazed to blade teeth.

Mounting blank in broaching machine

Different Types Of Broaches And Their Applications Internal broaching or External broaching Pull type or Push type Ordinary cut or Progressive type Solid, Sectional or Modular type Profile sharpened or form relieved type

Internal and external broaching (tool) Internal broaching tools are used to enlarge and finish various contours in through holes preformed by casting, forging, rolling, drilling, punching etc. internal broaching tools are mostly pull type but may be push type also for lighter work.

Internal broaching (tool)

Internal broaching (tool)

External broaching broaching (tool) Applications of external broaching are : un-obstructed outside surfacing; flat, peripheral and contour surfaces grooves, slots, keyways etc. on through outer surfaces of objects external splines of different forms teeth of external spur gears or gear sectors

External broaching broaching (tool)

External broaching broaching (tool)

Ordinary – cut and Progressive type broach Ordinary – cut type where the teeth increase in height or protrusion gradually from tooth to tooth along the length of the broach Progressive – cut type broaches have their teeth increasing in width instead of height

Ordinary – cut and Progressive type broach

Solid, Sectional and module type broaches

Broaching Machines Broaching needs only one motion and that is the cutting motion (velocity) preferably being imparted to the broach Design, construction and operation of broaching machines, requiring only one such linear motion, are very simple

Broaching Machines Broaching machines are generally specified by Type : horizontal, vertical etc. Maximum stroke length Maximum working force (pull or push) Maximum cutting velocity possible Power

Broaching Machines Classification According to purpose of use general purpose single purpose special purpose According to nature of work internal broaching external (surface) broaching

Broaching Machines Classification According to configuration horizontal vertical According to number of slides or stations single station type multiple station type indexing type According to tool / work motion intermittent (one job at a time) type continuous type

Broaching Machines

Broaching Machines occupies less floor space are more rigid as the ram is supported by base mostly used for external or surface broaching though internal

High production broaching machines incorporating automation in tool – job mounting and releasing increasing number of workstations or slides for simultaneous multiple production quick changing the broach by turret indexing continuity of working

Planer and Boring Machines

Planing Machine

Planing machine simple kinematic system of the planing machine enables transmission and transformation of rotation of the main motor into reciprocating motion of the large work table and the slow transverse feed motions (horizontal and vertical) of the tools

Planing machine The reciprocation of the table, which imparts cutting motion to the job, is attained by rack-pinion mechanism.

Planing machine The rack is fitted with the table at its bottom surface and the pinion is fitted on the output shaft of the speed gear box which not only enables change in the number of stroke per minute but also quick return of the table

Planing machine The blocks holding the cutting tools are moved horizontally along the rail by screw-nut system and the rails again moved up and down by another screw-nut pair

Planing machine operations

Planing machine operations

Planing machine operations All the operations done in shaping machine can be done in planing machine. But large size and stroke length and higher rigidity enable the planing machines do more heavy duty work on large jobs and their long surfaces.

Planing machine operations Simultaneous use of number of tools further enhances the production capacity of planing machines

Planing Machines

Planing Machines

Planing Machines

Planing Machines

Planing Machines

Planing Machines

Boring Machines

Boring Machines

Fllor type BM

Cylinder Boring Machine