Manuals Fixture Design Pdf


Friday, September 6, 2019

Chapter 1. Introduction to Fixture Design. 1. Introduction. A fixture is a device for locating, holding and supporting a workpiece during a manufacturing operation. Design of Fixtures. Types of Fixture and its Industrial Application. Vise Fixture. Milling Fixture. Facing Fixture. Boring Fixture. fixture is to locate and in some cases hold a workpiece during either a machining FOOL PROOF: The design of jigs and fixtures should be such that it would.

Fixture Design Pdf

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PDF | Modern market imposes stringent demands regarding the product In this paper, a system for computer-aided fixture design is presented and verified. 𝗣𝗗𝗙 | In machining fixtures, minimizing workpiece deformation due to clamping and cutting forces is essential to maintain the machining accuracy. The various. The flexible fixture has been applied in many areas because it can adapt to the worNpiece shape and size change, such as aircraft integral structure.

UNIT I Pupose of Tool Design 5Design designer possesses, these skilled toolmakers can often see solutions that may not be obvious to theIn this phase, the tool designer is responsible for designer. For this reason, it is always a good idea todeveloping the drawings and sketches of the tool build a good working relationship with your toolmak-design ideas. Design drawings are usually subject to ers. In tool design, a cooperative relationship betweenapproval by a chief designer. However, in smaller the designer and the toolmakers is essential.

Not onlycompanies, the tool designer often makes the tooling does working together make the task at hand easier,decisions. Often a tool designer is responsible for obtaining theSupervision for a single section, such as design or materials to make the tool.

In either supply materials and parts that meet the design speci-case, the ability to lead others is helpful.

When selecting a vendor, a good practice is to choose the company that offers the most service to One resource a tool designer may often use to its customers. Services such as design assistance andhelp resolve design problems is the group of skilled problem solving, where their product is involved, arepeople in the toolroom. The toolroom is the area in a important factors to consider before making a finalshop where the machine tools and the skilled work- selection.

Another point to consider is whether theforce are found. These skilled trades employees are vendor can supply special parts or components whencapable of taking the prints for the individual compo- necessary. Generally, the specialty vendors can fur-nents of a tool and manufacturing them, assembling nish special items for much less than those items costthe parts, and verifying their accuracy.

A variety of to make in-house.

Automated fixture design

Regardless of the level of skill aImage not available due to copyright restrictions Copyright Cengage Learning. First, the tool itself is inspectedfor compliance with the tool drawing. Second, several The following important concepts were presented intest parts are produced with the tool and are carefully this unit:checked to ensure that they conform to the specifica-tions shown on the part print.

List the seven objectives of tool design. Determine the source of the following data by indicating 1 for the part drawing, 2 for the pro- duction plan, and 3 for additional instructions.

Time allocation b. Overall size and shape of the part c. Required accuracy d. Sequence of operations e. Type and size of machines used f. Money available Copyright Cengage Learning. Number of pieces 3. What does the term concurrent mean and how ish.

Previous machining it applied to the design of tooling? Locating surfacesj.

Material specifications 4. Describe a toolroom. Type of cutters needed 5.

Jig and Fixture Design Manual - Erik K. Hendriksen_

List the skills of a tool designer. Type of machining required Copyright Cengage Learning. Jigs are usually fitted with hard- ened steel bushings for guiding drills or other cuttingAfter completing this unit, the student should be tools Figure 2—1A.

If, however, holes above. Set blocks and feeler or thickness gauges are used with fixturesJigs and fixtures are production-workholding devices to reference the cutter to the workpiece Figure 2—1B.

Principle of Fixture Design

The A fixture should be securely fastened to the table ofcorrect relationship and alignment between the cutter, the machine upon which the work is done. Thoughor other tool, and the workpiece must be maintained. Fixtures vary in design from relatively simple Jigs and fixtures are so closely related that the tools to expensive, complicated devices.

Fixtures alsoterms are sometimes confused or used interchangeably. It is a production Jigs may be divided into two general classes: boringtool made so that it not only locates and holds the jigs and drill jigs. Boring jigs are used to bore holesworkpiece but also guides the cutting tool as the oper- that either are too large to drill or must be made an odd size Figure 2—2. Drill jigs are used to drill, 8 Copyright Cengage Learning.

The more than one side. The names used to identify thesebasic jig is almost the same for either machining oper- jigs refer to how the tool is built. The only difference is in the size of the bushingsused.

Template jigs are normally used for accuracy rather than speed. Templates are the least expensive and simplest type of jig to use. TheyDrill jigs may be divided into two general types, open may or may not have bushings.

When bushings are notand closed. Open jigs are for simple operations where used, the whole jig plate is normally hardened.

Closed, or Figure 2—2 Boring jig. Figure 2—4 Template jigs. Plate jigs are similar to templates Figure 2—5. Figure 2—6 Table jig. The only difference is that plate jigs have built-inclamps to hold the work.

These jigs can also be madewith or without bushings, depending on the numberof parts to be made. Plate jigs are sometimes madewith legs to raise the jig off the table for large work.

This style is called a table jig Figure 2—6. Sandwich jigs are a form of plate jig with a backplate Figure 2—7. This type of jig is ideal for thin orsoft parts that could bend or warp in another style ofjig. Here again, the use of bushings is determined bythe number of parts to be made. Angle-plate jigs are used to hold parts that aremachined at right angles to their mounting locators Figure 2—8.

Pulleys, collars, and gears are some ofthe parts that use this type of jig. A variation is themodified angle-plate jig, which is used for machiningangles other than 90 degrees Figure 2—9. Both ofthese examples have clearance problems with the cut-ting tool.

As the drill exits the product being drilled,it has little or no room for the drill point to clear theproduct completely, produce a round hole all the waythrough the part wall, and avoid drilling the part loca-tor. This is most noticeable in Figure 2—9, where anangled hole requires additional clearance to therelieved portion of the part locator.

Additional clear-ance here would allow the drill to complete the holeand avoid drilling the relieved portion of the locator.

The part locator will most likely be hardened and the Copyright Cengage Learning. Figure 2—8 Angle-plate jig. Figure 2—9 Modified angle-plate jig. Channel jigs are the simplest form of box jig FigureAdditional clearance on the relieved diameter of the 2— The work is held between two sides andpart locator may be possible.

A larger clearance hole machined from the third side. In some cases, where jigin the locator could also be added if the relieved feet are used, the work can be machined on three sides. The additional designconsideration added to the locator would include the Leaf jigs are small box jigs with a hinged leaf tofeature to provide the correct orientation of this clear- allow for easier loading and unloading Figure 2— Leaf jigs are normally smaller than box jigs and are sometimes made so that Box jigs, or tumble jigs, usually totally surround they do not completely surround the part.

They arethe part Figure 2— This style of jig allows the usually equipped with a handle for easier movement. Indexing jigs are used to accurately space holes or other machined areas around a part. To do this, the Copyright Cengage Learning. Figure 2—11 Channel jig. The final station is used for unloading the fin- ished parts and loading fresh parts. This jig is commonly used on multiple-spindle machines. It could also work on single-spindle models.

There are several other jigs that are combinations of the types described. These complex jigs are often so specialized that they cannot be classified. Regardless of the jig selected, it must suit the part, perform the opera- tion accurately, and be simple and safe to operate. Larger indexing jigs are calledrotary jigs. The names used to describe the various types of fix- tures are determined mainly by how the tool is built.

Trunnion jigs are a form of rotary jig for very Jigs and fixtures are made basically the same way aslarge or odd-shaped parts Figure 2— The part is far as locators and positioners are concerned. Thefirst put into a box-type carrier and then loaded on the main construction difference is mass. Because of thetrunnion.

This jig is well suited for large, heavy parts increased tool forces, fixtures are built stronger andthat must be machined with several separate plate- heavier than a jig would be for the same part. Plate fixtures are the simplest form of fixture Pump jigs are commercially made jigs that must be Figure 2— The basic fixture is made from a flatadapted by the user Figure 2— The lever-activated plate that has a variety of clamps and locators to holdplate makes this tool very fast to load and unload.

Since and locate the part. The simplicity of this fixturethe tool is already made and only needs to be modified, makes it useful for most machining operations. Itsa great deal of time is saved by using this jig. Multistation jigs are made in any of the forms The angle-plate fixture is a variation of the platealready discussed Figure 2— The main feature of fixture Figure 2— With this tool, the part is nor-this jig is how it locates the work.

While one part is mally machined at a right angle to its locator. While Copyright Cengage Learning. Figure 2—13 Indexing jig.

In parts Figure 2— With this type of tool, the stan-these cases, a modified angle-plate fixture can be dard vise jaws are replaced with jaws that are formedused Figure 2— Vise-jaw fixtures are the least expen- Copyright Cengage Learning. Figure 2—15 Pump jig. The parts shown in Figure 2—22 are examples of the uses of an indexing fixture. Their use is limited onlyby the sizes of the vises available.

Multistation fixtures are used primarily for high- speed, high-volume production runs, where the Indexing fixtures are very similar to indexing jigs machining cycle must be continuous. Duplex fixtures Figure 2— These fixtures are used for machining are the simplest form of multistation fixture, usingparts that must have machined details evenly spaced.

This form allows the loading and unloading operations to be performed while the machining operation is in progress. For example, once the machining operation is complete at station 1, the tool is revolved and the cycle is repeated at station 2.

At the same time, the part is unloaded at station 1 and a fresh part is loaded. Profiling fixtures are used to guide tools for machining contours that the machine cannot normally follow. These contours can be either internal or exter- nal. The expert systems have been mostly used for the generation of partial fixture solutions, i. Shrikant et al. The proposed eccentric shaft sequence is done then he determined the fixture will fulfilled researcher Production contact forces in clamping sequence as target and enhanced the efficiency, fixture shown in Figure 1.

After that he optimized of reduces operation time and increases clamping sequence for higher stiffness productivity, high quality of operation. He found that with the use of optimal clamping Clamping Approach sequence, good agreements are achieved J Cecil proposed an innovative clamping between predicted results and experimental design approach is described in the context data and the workpiece machining quality can of fixture design activities.

The clamping be improved. This approach can be is emphasized by Djordje Vukelic Michael applied in conjunction with a locator design Stampfer, Detailed steps are given for automated this polynomial fit based method is more clamp design. Geometric reasoning techni- accurate than the traditional method and it ques are used to determine feasible clamp can perform more effectively for fault detec- faces and positions.

The required inputs tion in hydraulic actuator control system.

Configuration of Hydraulic Actuator points and elements. Control System Wang Jinyong, Figure 3: In addition electric booster and hydraulic pump are used to air- operated booster system.

Hydraulic pump is used for larger applications. Accumulator is installed between clamps and power source which maintain the necessary pressure when power is disconnected. To reduce design costs associated with fixturing, various clamping methods have been developed through the years to assist Hydraulic System the fixture designer E Caillaudli D et al.

This are method is used to simulate two kinds of typical hydraulic actuator control system. Through Wildfire 5. Following are the machining parameters for reaming: To avoid this problem consideration of material of fixture and after there is necessity to develop new design to that analytical design of parts such as design improve the productivity. Type of Machine Vertical machining centre is used to perform Criteria for Material Selection of Fixture operation on hydraulic lift housing.

The Mechanical Properties machining is to done on the upper surface of The material must possess a certain strength the workpiece. VMC provides the features and stiffness.

Basically operations such as drilling, reaming and chamfering takes place Wear of Materials on workpiece. Drilling is a cutting process that Wear is a problem when the materials are uses a drill bit to cut or enlarge a hole of contacting each other in a product. When estimating sufficient wear resistance.

It may involve the transportation, The importance of material selection in processing, etc. Also it is an important Design of Base Plate engineering design criterion for designs open While designing base plate total length should to the environment for a longer period of time.

Therefore it must be assured that the material is capable of being employed Design of Clamp for the particular design before selecting it.

Figure 6: Clamp of Fixture Ability to Manufacture The material is well capable of using for the design, it may be difficult to manufacture. This is particularly applicable in mechanical engineering design.

If this selection criteria is neglected the manufacture process might be very costly making it unprofitable as a commercial product. So before selecting the materials this fact also must be considered. Cost Cost is a critical fact to consider when selecting materials for a certain design for most products because they are facing a severe competition in the market.

So you may see that most of the metal or other valuable materials are replaced by plastics in most of the designs which they are applicable such as mechanical engineering designs. Minimum and Maximum Von Misses Stress or Equivalent Tensile Stress Hydraulic clampings are actuated by cylin- ders, clamping fixtures is clamping nut attach- ed to cylinder ram.

When pressurized fluid pulls ram and clamps against workpiece, toggle clamps operate through a linkage Figure 7 shows a stress distribution across system of levers and pivots. The fixed-length the fixture A force of N is applied on three levers, connected by pivoting pins, apply the points where clamping force acting on it. After action and clamping force.

The toggle action analysis it is observe that, von misses has a lock point which fixes and stops linkage. Production cost of Rs. Kailing Li et al. Engineering, Weifang University. Dan Ding Guoliang et al. Automation Washington, DC. E Caillaudli D et al. Research and General Science, Vol.

Weifang Chen, et al. Yan Zhuang and Ken Goldberg , This style is called a table jig Figure 2—6. By Hiren Chauhan. Moreover, HMC costs around Clamping can be of all design and manufacturing industries sequenced automatically during the Dan Ding Guoliang et al. Need an account?