Design Of Angular Post Jig 4445d

ABSTRACT In this project it is based on the need for the work holding devices. This design and fabrication which will enable the operation like drilling, reaming, tapping process easier. This project is mainly composed of “DESIGN AND FABRICATION OF THE ANGLE PLATE JIG” which cover the absolute design to the specified dimensions of the work piece. This angle plate jig is economical means to produce

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1. INTRODUCTION 1.1 INTRODUCTION Mass production aims at high productivity to reduce unit cost and interchange ability to facilitate easy assembly. This necessitates production devices to increase the rate of manufacture and inspection device to speed-up inspection Procedure. Jigs are special purpose tools which are used to facilitate production like machining, assembling and inspection operations. The mass production of work-piece is base on the concept of interchange ability according to which every part produced within an established tolerance. Jigs provide a means of manufacturing interchangeable parts since they establish a relation with predetermined tolerances, between the work and the cutting tool. Once the jig is properly set up, any number of duplicate parts may be readily produced without additional set up. Jigs are used on drilling, reaming, tapping, milling and tapping. There are many Advantages for using jigs in production. Jigs eliminate individual making, positioning and frequent checking. This reduces operation time and increase productivity. There is no need for selective assembly. 1.2 OBJECTIVES i.

This jig has built in accuracy, the precision positional relationship b/w jig

ii. iii. iv.

bushes in different planes are ed on work piece. Jig is a source which holds the job strongly and also guides the tool. It eliminates the need for marking on the job. These are light weight these can be used either by fastening them with the

v.

table or holding them in hands. Even an unskilled technician can use them with these features, we sincerely hope that our project serve as a valuable project. We welcome the correction, comments based on our project.

2. LITERATURE REVIEW

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2.1 INTRODUCTION This chapter discussed about literature review of jigs deg for the angular cylindrical part. It begins with introduction to the jigs, type of jigs and components in the jigs. Furthermore, the advantages and disadvantages of the jigs were discussed and the important of the jig design were discussed briefly. 2.2 INTRODUCTION TO JIGS Mass

production

aims

at

high

productivity

to

reduce

unit

cost,

and

interchangeablities to facilitate easy assembly. This production device increases the rate of manufacturing and inspection devices to speed up inspection procedure. Jigs are specially provided for mass production. Jigs provide a means of manufacturing interchangeable parts since they establish a relation, with predetermined tolerances, between work and cutting tool. So, they eliminate the necessity of a special set up for each individual part thereby reducing the cost. So, jigs are generally used i. ii. iii. iv. v.

To reduce the cost of the production. To assure high accuracy of parts. To increase the production. To save labour cost. To value quality control expense.

Some of the basic requirements of a good drill jigs are: i.

Quick and accurate location of the work piece. 3

ii.

Easy loading and unloading of the work piece and prevention of wrong

iii. iv. v.

loading. Prevention of bending or movement of the work piece during drilling. Ample chip clearance which facilitates for swarf removal and cleaning. Light weight to minimize operator fatigue due to repeated handling.

Figure 2.1: jig In the shop, drill jigs are the most-widely used form of jig. Drill jigs are used for drilling, tapping, reaming, chamfering, counter-boring, countersinking, and similar operations.

2.2.1 Elements in Jigs

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Figure 2.2: Elements in Jigs i. ii. iii. iv. v. vi. vii. i.

Jig body Jig feet Jig bushing Jig plate or bush plate Locators Clamps Fool proof element Jig body The jig body s the work piece and has locating and clamping elements in

it. It is provided with four jig feets and rests on the machine table. ii.

Jig feet a jig feet which is not bolted to machine table is provided with four jig feet,

instead of the entire bottom surface lying flat on the machine table. Jig feet are either cast with the jig body or detachable or welded to the base. They are usually hardened and ground to have flat bottom. iii.

Jig bushing For guiding drills, reamers and boring bars, hardened steel jig bushes are

employed which are fixed in the jig plates. The bushes can be replaced when wornout with less cost than replacing the entire jig plate. 5

iv.

Jig plate or bush plate Usually the jig plate carries the jig bush for guiding the tools. The jig plate may

be rigidly constructed as a single unit of jig or it may be of leaf or latch type. In this type, the jig plate must be clamped with the jig frame. v. Locators Locators help a work piece to ret in proper position in a jig. Depending on the type of work piece, various types of locators are used for the locating the components, in the jig with reference to the tools, the locators are usually detachable type, fixed to the jig frame. So whenever wear occurs, the locators can be easily replaced with new ones. vi. Clamps Clamps are used for holding the work piece rigidly against all disturbing forces. They also keep the work piece firmly in with locating pins of surfaces. Sufficient thickness of section should be provided to withstand clamping forces. vii. Fool proof element This element prevents the work from being loaded wrongly into the jig. The elements may be simple fouling pegs, cross pieces or pins.

2.3 IMPORTANT OF JIGS Jigs are very important in manufacturing industry. These tools needed to make sure that manufacturing process in production line going smooth and easier to operator doing their job. Jig helps operator to holding part which will be processing or in operation. In production rate, using jigs increased the productivity because it will minimize the production time. 2.3.1 Advantages i.

Productivity Jigs eliminate individual marking, positioning and frequent checking. This reduces operation time and increases productivity. 6

ii.

Interchange ability Jigs facilitate uniform quality in manufacture. There is no need for selective assembly. Any part of the machine would fit properly in assembly, and all similar components are interchangeable.

iii.

Skill reduction Jigs simplify locating and clamping of the work-pieces. Tool guiding elements ensure correct positioning of the tools with respect to the work pieces. There is no need for skilful setting of the work-piece or tool. Any average person can be trained to use jigs. The replacement of a skilled workman with unskilled labour can effect substantial saving in labour cost.

iv.

Cost reduction Higher production, reduction in scrap, easy assembly and savings in labour costs result in substantial reduction in the cost of work-pieces produced with jigs.

2.3.2 Disadvantages In industry, using jigs is very important in operation. Nowadays, tool is more important than workman skill. This will make the industrial lacking skilful man in workplace. When the tool is breakdown, the production rate will be decrease. Cost for maintenance will be higher.

2.4 TYPES OF JIGS Jigs mainly divided in to two types 1. Boring jigs 2. Drill jigs 1. Boring jig

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Figure 2.3: Boring Jig In machining, boring is the process of enlarging a hole that has already been drilled, by means of a single-point cutting tool or of a boring head containing several such tools, for example as in boring a gun barrel or an engine cylinder. Boring is used to achieve greater accuracy of the diameter of a hole, and can be used to cut a tapered hole.

2. Drill Jig

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Figure 2.4: Drill Jig Drill jigs are used to drill, ream, tap, chamfer, counter bore, counter sink, reverse spot face, or reverse counter sink. The basic jig is almost the same for either machining operation. The only difference is in the size of the bushings used.

2.4.1 Types of Drill Jigs Drill jigs may be divided into two general types 1. Open jig 2. Closed jig Open jigs are for simple operations where work is done on only one side of the part. Closed, or box, jigs are used for parts that must be machined on more than one side. Drill jigs are designed and constructed based on structure work piece. Some type’s jigs listed below 1. Template Jig

2. Plate Jig 9

3. Sandwich Jig 4. Latch or Leaf Jig 5. Channel Jig 6. Box Jig 7. Post jigs 8. Angle plate Jig 9. Angular post Jig 10. Turnover jig or Table type Jig 11. Pot Jig

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12. Solid Jig 13. Trunnion Jig 14. Indexing Jig 15. Universal Jig or Pump Jig 16. Multi Station Jig 17. 18.

19.

I.

20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 35. 36. 37. 38. 39. 40. 41. Template Jig 42.

43.

Figure 2.5: Template Jig 44.

45.

This is a simple plate of metal or wood which carries correct locations

of holes to be made in the work piece. Size of template jig should be same as that of the work piece. It is overlapped with the work piece and drilling is done quickly. Use of this jig avoids the marking operation completely. 46. 47. 48. 49. 50. 51. 52. 53. 54. 55. 56. 57. 58. 59. 60. 61. 62. 63. II. Plate Jig

64.

65. Figure 2.6: Plate Jig 67. 68. Plate jigs are similar to templates jigs. The only difference is that plate jigs have built-in clamps to hold the work. These jigs can also be made with or without bushings, depending on the number of parts to be made. 69. 70. 71. 72. 73. 74. 66.

3. Sandwich Jig 75. 76.

77.

79.

Figure 2.7: Sandwich Jig 78. The sandwich jig is almost similar to plate jig. The only difference is the

backup plate found on the sandwich jig. This back up plate allows the jig to hold very thin parts that could bend or distort under tool pressure. The sandwich jig can also be used as a combination jig in which one side of the tool is used to locate the part for drilling. The opposite side is used for reaming or tapping the part. 80.

4. Latch or Leaf Jig

81.

83.

Figure 2.8: Latch or Leaf Jig 82. Leaf jig is also called as latch jig. This type of jig is distinguished by its

hinged cover, a leaf which can swing open to load or unload the work piece. After the work piece has been located inside the jig, the leaf is firmly closed and locked inside the jig. The leaf is held on to the jig body with the help of an eyebolt where the eye is hinged to the body with a pin and a nut on the threaded portion of the bolt tightens the leaf. The drill bushes are fitted in the leaf. 84. Leaf jigs can be loaded and unloaded quickly and are suitable for complicate work pieces with irregular contours. The disadvantage of leaf jigs is that chips may accumulate inside and cause trouble unless provisions are made for disposing them. Also, if the drill bushings are fitted in the leaf, play in the hinges may affect drilling accuracy. 85. 86. 87. 88. 89. 90. 91. 92. 93. 5. Channel Jig

94.

95.

97.

96. Channel jigs are the simplest form of box jig. The work is held between

two sides and machined from the third side. In some cases, where jig feet are used, the work can be machined on three sides. 98. 99. 100. 101. 102. 103. 104. 105.

6. Box Jig 106.

107.

109.

Figure 2.11: Box Jig 108. Box jigs, or tumble jigs, usually totally surround the part. This style of

jig allows the part to be completely machined on every surface without the need to reposition the work in the jig. Channel jigs are the simplest form of box jig. The work

is held between two sides and machined from the third side. In some cases, where jig feet are used, the work can be machined on three sides. 110. 111. 112. 113. 114. 115. 116. 7. Post Jig 117. Vertical

118. 119. 120. Horizontal

Figure 2.12: Post Jig Vertical

121.

122.

124.

Figure 2.13: Post Jig Horizontal 123. The post jig is used to locate the drill plate. The swing washer enables

the drill plate to be removed without removing the hand nut. The post jig is also used for drilling and reaming, a ‘C’ washer is used to obviate the need to remove the hand nut. 8. Angle Plate Jig

125.

126.

128.

Figure 2.14: Angle Plate Jig 127. Angle-plate jigs are used to hold parts that are machined at right

angles to their mounting locators. Pulleys, collars, and gears are some of the parts that use this type of jig. 129. 130. 131. 132.

133. 134. 135. 136. 137. 138. 9. Angular Post Jig

139.

140.

Figure 2.15: Angular Post Jig

142.

141. Angle-plate jig, which is used for machining angles other than 90

degrees. Figure shows an angular post jig of welded construction. The drill bush is extended and shaped to prevent drill run, and yet allow removal of work piece. The clamping nut is of the quick-action type because the smallness of the work piece bore demands that the nut be removed when the work piece is removed. 143. 144. 145. 146. 10. Turnover Jig or Table Type Jig

147.

148. 149.

Figure 2.16: Turnover Jig or Table Type Jig

Plate jigs are sometimes made with legs to raise the jig off the table for

large work. This style is called a table jig. 150. 151. 11. Pot Jig 152. Work Piece

153. 154.

155.

157.

Figure 2.17: Pot Jig 156. Pot jig body is in the form of a pot in which the work piece is ed

and clamped. Circular work pieces which have both an external diameter and an internal diameter suitable for location purposes are drilled in pot type jigs. The jig essentially consists of two parts. The body which is in the form of a pot carries the work piece and also the bush plate. 158. Figure illustrate a pot jig in which the work piece is located from its outside in the bush, and the drill bush is located on a post; the drill plate is located to line up with swarf clearance grooves. 12. Solid Jig 159. 160.

161. Figure 2.18: Solid Jig 163. The figure shows a solid jig that is made from a block of steel. The 162.

164.

work piece is clamped by a button clamp, and burr groves are provided so that the work piece can be easily recovered. Two grooves are required because one burr will be produced at the point of drill entry, and a second burr is produced at the point of drill break through. 165. 166. 167.

168. 169. 170. 171. 172. 173. 174. 175. 176. 177. 178. 13. Trunnion Jig

179.

180.

182.

Figure 2.19: Trunnion Jig 181. A trunnion jig is similar to a box jig. When a large sized work piece is to

be drilled in several faces, it is mounted in a trunnion jig so that the faces requiring drilling operations can be turned easily and positioned. Every time, the jig is rotated and it is locked so that the face in which the hole is to be drilled is absolutely horizontal. The pin and the locating hole for locking the jig should be wear resistant. 183. 184. 185. 14. Indexing Jig

186.

187.

Figure 2.20

189.

188. Indexing jigs are used to accurately space holes or other machined

areas around a part. To do this, the jig uses either the part itself or a reference plate and a plunger. Larger indexing jigs are called rotary jigs. 190. 191. 192. 193. 194. 195. 15. Universal Jig or Pump Jig

199.

196. 197. Figure 2.21: Universal Jig or Pump Jig 198. Pump jigs are commercially made jigs that must be adapted by the

. The lever-activated plate makes this tool very fast to load and unload. Since the tool is already made and only needs to be modified, a great deal of time is saved by using this jig. 200. 201. 202. 16. Multi Station Jig

203. 204.

Figure 2.22: Multi Station Jig 205.

206.

Multi station jigs feature is how it locates the work. While one part is

drilled, another can be reamed and a third counter bored. The final station is used for unloading the finished 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 operation accurately, and be simple and safe to operate. 207. 2.5 Materials 208.

Jigs are made of variety of materials, some of which can be

hardened to resist wear. 209. 210. 2.5.1 Materials generally used 211. i. ii.

iii. iv.

v.

High speed Steel 212. Cutting tools like drills, reamers and milling cutters. Die steels 213. Used for press tools, contain 1% carbon, 0.5 to 1% tungsten and less quantity of silicon and manganese. Carbon steels 214. Used for standard cutting tools. Collet steels 215. Spring steels containing 1% carbon, 0.5% manganese and less of silicon. Non shrinking tool steels: 216.

High carbon or high chromium Very little distortion during heat

treatment. Used widely for fine, intricate press tools. vi. vii. viii.

Nickel chrome steels 217. Used for gears. High tensile steels 218. Used for fasteners like high tensile screws Mild steel 219. 220.

ix.

221. Cast Iron 222.

Used in most part of Jigs and Fixtures Cheapest material Contains less than 0.3% carbon Used for odd shapes to some machining and laborious

fabrication 223. CI usage requires a pattern for casting 224. Contains more than 2% carbon

225. 226. 227. x.

xi.

Nylon and Fiber 228. Used for soft lining for clamps to damage to work piece due to clamping pressure Phosphor bronze 229. 230. 231. 232. 233. 234. 235. 236. 237. 238. 239. 240. 241. 242. 243. 244. 245. 246. 247. 248. 249. 250. 251. 252. 253. 254. 255. 256. 257. 258.

261.

Can withstand vibrations and suitable for base

Used for nuts as have high tensile strength Used for nuts of the lead screw

259. 3. DESIGN AND FABRICATION 260. 3.1 Components of Angular Post Jig  Plunger pin  Drill bush  Index plate  Quick-action nut  Angular plate  Jig base plate  Jig top plate



Jig vertical plate 262. 263. 264. 265. 266. 267. 268. 269. 270. 271. 272. 273. 274. 275. 276. 277. 278. 279. 280. 281. 282. 283. 3.2 Construction

284. 285.

286.

The angular post jig construction is vertical plate is welded in the base

plate. Top plate is welded in the vertical plate. The one end of the angular plate is welded in the base plate then other end is welded in the top plate. Angular plate used for ed the work piece. Index plate is fitted upper surface of the angular plate with the help of plunger pin. Quick-action nut is used for locking and also ing the work piece. Drill bushes are fitted in top plate according to the work piece.

287.

288. 289. 290. 291. 292. 293. 294. 295. 296. 297. 3.3 Part drawing 298.

Figure 3.1: Angular Post Jig

299. 300. 301.

302. 303. 304.

FRONT VIEW

SIDE VIEW

TOP VIEW

ISOMETRIC VIEW

305. Figure 3.2: Pictorial View of Angular Post Jig 306. 307. 308. 309. 310. 311. 312. 313. 3.4 Working Principle 314. Angle-plate jig, which is used for machining angles other than 90 degrees. The angular post jig of welded construction. The drill bush is extended and shaped to prevent drill run, and yet allow removal of work piece. The clamping nut is of the quick-action type because the smallness of the work piece bore demands that the nut be removed when the work piece is removed. 315.

316.      

3.5 Advantages Produce high accuracy of parts Save labour cost Quick and accurate location of work piece Easy loading and unloading Mass production Reduce the cost of production 317. 318. 3.6 Applications  Mass production industries  Angular component manufacturing 319. 3.7 Bill of Material 320. S. No

321. Part

322. Mater

323. Quan

324. 1

Name 325. Base

ial 326. M.S.

tity 327. 1

328. 2

plate 329. Vertic

330. M.S.

331. 1

332. 3

al plate 333. Top

334. M.S.

335. 1

336. 4

plate 337. Angul

338. M.S.

339. 1

340. 5 344. 6

ar plate 341. Bush 345. Index

342. M.S. 346. M.S.

343. 1 347. 1

plate 348. 349. Table 3.1: Bill of Material 350. 351. 352. 353. 3.8 Essential Features of Jigs i. Reduction of idle time 354. Should enable easy clamping and unloading such that idle time is ii.

iii.

minimum. Cleanliness of machining process 355. Design must be such that not much time is wasted in cleaning of scarfs, burrs, chips etc. Replaceable part or standardization

356. The locating and ing surfaces as far as possible should be replaceable, should be standardized so that their interchangeable manufacture iv.

is possible. Provision for coolant 357. Provision should be there so that the tool is cooled and the swarfs and

v.

chips are washed away. Hardened surfaces 358. All locating and ing surfaces should be hardened materials as far as conditions permit so that they are not quickly worn out and accuracy is

vi.

retained for a long time. Inserts and pads 359. Should always be riveted to those faces of the clamps which will come

vii.

in with finished surfaces of the work piece so that they are not spoilt. Fool-proofing 360. Pins and other devices of simple nature incorporated in such a position that they will always spoil the placement of the component or hinder

viii.

the fitting of the cutting tool until the latter are in correct pos. Economic soundness 361. Equipment should be economically sound; cost of design and

ix.

manufacture should be in proportion to the quantity and price of producer. Easy manipulation 362. It should be as light in weight as possible and easy to handle so that workman is not subjected to fatigue, should be provided with adequate lift

x.

xi.

xii.

aids. Initial location 363. Should be ensured that work piece is not located on more than 3 points in anyone plane test to avoid rocking, spring loading should be done. 364. Position of clamps 365. Clamping should occur directly above the points ing the work piece to avoid distortion and springing. Clearance 366. Sufficient amount of clearance should be provided around the work so that operator’s hands can easily enter the body for placing the work

xiii.

xiv.

piece and any variations of work can be accommodated. Ejecting devices 367. Proper ejecting devices should be incorporated in the body to push the work piece out after operation. Rigidity and stability

368.

It should remain perfectly rigid and stable during operation.

Provision should be made for proper positioning and rigidly holding the jigs and xv.

fixtures. Safety 369. 370. 371. 372. 373. 374. 375. 376. 377. 378. 379. 380. 381. 382. 383. 384. 385. 386. 387. 388.

The design should assure perfect safety of the operator.

389. CONCLUSION 390.

The project work has provided us an excellent opportunity and

experience to use our limited knowledge. We gained a lot of practical knowledge regarding planning, purchasing, assembling and machining while doing this project work. We feel that the project work is good solution to bridge the gates between institution and industries. 391. 392. We are proud that we have completed the work in limited time successfully. The “Design and Fabrication of Angular Post Jig” is working with satisfactory conditions. We are able to understand the difficulties in maintaining tolerance. We have to done to our ability and skill making maximum use of available facilities. 393. 394. In conclusion remarks of our project work, let us add a few more lines about our impression project work. We feel very proud in submitting this report to our institution. 395. 396. 397. 398.

399. 400. 401. 402. 403. 404. 405. 406. 407. 408. 409. 410. 411.

412. REFERENCE 413.  Jigs and fixtures, press tools – C. Elanchezhilan and B. Vijaya Ramnath

 www.jigsand fixtures.com 414.