Jig & Fixture Design
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EPD 332 Tooling Design Group 5
Jig & Fixture DesignGroup Leader : Ong Chern Chung Group Members: 1. Ho Chi Leng 2. Tan Kai Yin 104962 104949 104968
3. Mohd Tasnim Bin Hassan @ Yahya 104958
School of Mechanical Engineering Date of Submission: 11th March 2012
Lecturer: Dr.Mohd.Salman Abu Mansor
Purpose of Tool Design1. Tool Design Tool design is the process of designing and developing the tools, methods, techniques necessary to improve manufacturing efficiency and productivity. 2. Tool Design Objectives
Maintaining Quality Lower Manufacturing Costs Increased Production
Main Objective of Tool Design
To accomplish the main objective, the tool designer must achieve the following objectives: Provide simple, easy-to-operate tools for maximum efficiency Reduce manufacturing expenses by producing parts at the lowest possible cost Design tools that consistently produce parts of high quality Increase the production rate with existing machine tools Design the tool to make it foolproof and to prevent improper use Select materials that will give adequate tool life Provide protection in the design of the tools for maximum safety of the operator 3. Tool Design in Manufacturing
Process Planning Engineers Concurrent Engineering Teams
Quality Control Designers
Concurrent engineering is a process that allows the design team to be invloved in a compressive plan for product design and prodution. Advantages : Result in fewer design errors Team members contribute based on their area of expertise Problems are not discovered on the production floor, but are corrected early in the concurrent process Saves time and money Speeding up the process of getting product to market earlier Company will have a distinct economic advantage in global market
4. Planning the Design Product design changes are continuosly reviewed to determine tooling changes that might be necessary. This is to eliminate or minimize the last-minute costly changes. The team meets regularly to provide any necessary updates or changes in the production plan. The team members usually use e-mail, electronic transfer of materials and teleconferencing to communicate with each other. Team members may consist of customers, designers, and builders in different locations that may take them halfway around the world. 5. Parts Drawing The parts drawing that the tool designers receives are transmitted electronically and may include a solid model. The solid model allows the designer to view the three dimensional part geometry. The prototype, a single physical part provided prior to formal production, is a valuable tool for understanding more complex part geometries. Prototype are usually manufactured using: i) Conventional Computer Numerical Control (CNC) ii) Stereolithography iii)Layered Object Manufacture ( LOM) Whether analyzing the prototype and the part drawing, the designer must consider the following factors that directly influence the design chioces: i) Overall size and shape of the part ii) Type and condition of the material used for the part iii) Type of machining operation to be performed iv) Degree of accuracy v) Number of pieces to be made vi) Locating and clamping surfaces
Stereolithography Stereolithography (SLA), also known as 3D printing, optical fabrication, photosolidification, solid free-form fabrication and solid imaging, is an additive manufacturing technology used for producing models, prototypes, patterns, and production parts.
Layered Object Manufacture ( LOM) Laminated object manufacturing (LOM) is a rapid prototyping system developed by Helisys Inc. (Cubic Technologies is now the successor organization of Helisys) In it, layers of adhesive-coated paper, plastic, or metal laminates are successively glued together and cut to shape with a knife or laser cutter.
6. Production Plan The production plan is an itemized list of the manufacturing operations and the sequence of the operations chosen by the process planning engineer. The production plan include the following: Type and size of the machine tool specified for eaach operation Type and size of cutters specified for each operation Sequence of operations Previous machining operations performed on the part 7. Alternatives Besides given the part drawing and the production plan, the tool designer is informed of the amount of time and money that is available to spend on the design. One of the important step in tool design is determining the alternative solutions to ensure that the best method is chosen.Should multiplespindle or singlespindle machines be used?
Should the tool be single-purpose or multi-purpose?
Will the savings justify the cost of the tool?
What type of gauge, if any, should be used to check each operation?
The tool designer need to answer the questions above and others related to the specific task to develops the alternative solutions. From this alternative solutions, the most efficient, dependable and cost effective design is chosen.
8. Challenges To The Tool Designer In addition to technical design duties, the tool designer need to understand also about obtaining materials, toolroom supervision, and tool inspection.
Tool room supervision
9. Design The tool designer is responsible for developing the drawings and sketches of the tool design ideas. 10. Supervision The extent of a tool designers supervision is normally determined by the size of the company. One resource a tool designer may often use to help resolve design problems is the group of skilled people in the tool room. The skilled toolmakers can often see solutions that may not be obvious to the designer; hence it is always a good idea to build a good working relationship with your toolmakers. Good working relationship between designer and the tool maker make the task at hand easier and by using the available expertise make more sense than trying to do the job alone. 11. Procurement o Tool designer normally relies on vendors or salespeople to supply materials and parts that meet the design specifications. o A few factors to be consider when selecting a vendor: Choose company that offers the most service to its customers Services such as design assistance and problem solving, where their product is involved Whether the vendor can supply special parts or components when necessary Which vendor can meet the designers needs in the most timely, efficient, and dependable manner 12. Inspection Inspection is normally conducted in two phases: First: The tool itself is inspected for compliance with the tool drawing. Second: Several test parts are produced with the tool and are carefully checked to ensure that they conform to the specifications shown on the part print. After the tool has been turned over to the production department, the tool designer should make periodic checks during production to ensure that the specified tolerances are maintained.
13. Requirements To Become A Tool Designer To perform the functions of a tool designer, an individual must have the following skills:
Ability to make mechanical drawings and sketches An understanding of modern manufacturing methods, tools, and techniques A creative mechanical ability
An understanding of basic toolmaking methods A knowledge of technical mathematics through practical trigonometry CAD drafting skills
Electronic communication skills
Geometric dimensioning and tolerancing
Jigs and FixturesJig is a guiding device and fixture is a holding device. Jigs and fixtures are used to locate and hold the work that is to be machined. Jigs and fixtures are production-workholding devices used to manufacture duplicate parts accurately. The correct relationship and alignment between the cutter, or other tool, and the workpiece must be maintained. To do this, a jig or fixture is designed and built to hold, support, and locate every part to ensure that each is drilled or machined within the specified limits.
JigsA jig is a special device that holds, supports, or is placed on a part to be machined. It is a production tool made so that it not only located and hold the workpiece but also guides the cutting tool as the operation is performed. Jigs are usually fitted with hardened steel bushings for guiding drills or other cutting tools. As a rule, small jigs are not fastened to the drill press table. If, however, holes above 0.25 inch in diameter are to be drilled, it is usually necessary to fasten the jig to the table securely. Classes of jigs Jigs may be divided into two general classes: i. Boring jigs. Boring jigs are used to bore holes that either are too large to drill or must be made an odd size. Drill jigs. Drill jigs are used to drill, ream, tap, chamfer, counterbore, countersink, reverse spotface, or reverse counter sink.
The basic jig is almost the same for either the same for either machining operation. The only difference is in the size of the bushings used.
Types of jigs 1. Drill jigs They may be divided into two general types: - Open type. Open jigs are for simple operations where work is done on only one side of the part. - Closed type. Closed, or box, jigs are used for parts that must be machined on more than one side. The names used to identify these jigs refer to how the tool is built.
2. Template jigs They are normally used for accuracy rather than speed. This type of jig fits over, on, or into the work and is not usually clamped. Templates are the leasr expensive and simplest type of jig to use. They may or may not have bushings. When bushings are not used, the whole jig plate is normally hardened
3. Plate jigs. They are simila