1、The Practical ReferenceGuide to PositioningThis publication is designed to provide information in regard to the subject mattercovered. It is made available with the understanding that the publisher is not engaged inthe rendering of professional advice. Reliance upon the information contained in this
2、document should not be undertaken without an independent verification of its applicationfor a particular use. The publisher is not responsible for loss or damage resulting from useof this publication. This document is not a consensus standard. Users should refer to theapplicable standards for their
3、particular application.550 N.W. LeJeune Road, Miami, FL 33126The Practical Reference Guide to Positioning2AcknowledgmentsInformation and excerpts throughout this Guide have been adopted from The NewHandbook of Positioneering, courtesy of Koike Aronson, Inc., Arcade, NY., and additionalinput provided
4、 by Pandjiris, Inc. Photographs are courtesy of Pandjiris, Inc., St. Louis,MO.International Standard Book Number: 978-0-87171-086-4American Welding Society550 N.W. LeJeune Road, Miami, FL 33126 2008 by American Welding SocietyAll rights reservedPrinted in the United States of AmericaPhotocopy Rights
5、. No portion of this document may be reproduced, stored in a retrieval system, ortransmitted in any form, including mechanical, photocopying, recording, or otherwise, without theprior written permission of the copyright owner.Authorization to photocopy items for internal, personal, or educational cl
6、assroom use only or theinternal, personal, or educational classroom use only of specific clients is granted by the AmericanWelding Society provided that the appropriate fee is paid to the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, tel: (978) 750-8400; Internet: .The Practical
7、Reference Guide to Positioning3Basic Safety PrecautionsBurn Protection. Molten metal, sparks, slag, and hot work surfaces are produced bywelding, cutting, and allied processes. These can cause burns if precautionary measuresare not used. Workers should wear protective clothing made of fire-resistant
8、 material. Pantcuffs, open pockets, or other places on clothing that can catch and retain molten metal orsparks should not be worn. High-top shoes or leather leggings and fire resistant glovesshould be worn. Pant legs should be worn over the outside of high-top shoes. Helmets orhand shields that pro
9、vide protection for the face, neck, and ears, and a head covering toprotect the head should be used. In addition, appropriate eye protection should be used.Electrical Hazards. Electric shock can kill. However, it can be avoided. Live electricalparts should not be touched. The manufacturers instructi
10、ons and recommended safepractices should be read and understood. Faulty installation, improper grounding, andincorrect operation and maintenance of electrical equipment are all sources of danger. Allelectrical equipment and the workpiece should be grounded. The workpiece lead is not aground lead. It
11、 is used only to complete the welding circuit. A separate connection isrequired to ground the workpiece. The workpiece should not be mistaken for a groundconnection. Fumes and Gases. Many welding, cutting, and allied processes produce fumes and gaseswhich may be harmful to health. Avoid breathing th
12、e air in the fume plume directly abovethe arc. Do not weld in a confined area without a ventilation system. Use point-of-weldingfume removal when welding galvanized steel, zinc, lead, cadmium, chromium,manganese, brass, or bronze. Do not weld on piping or containers that have heldhazardous materials
13、 unless the containers have been properly made inert.Compressed Gas Cylinders. Keep caps on cylinders when not in use. Make sure that gascylinders are chained to a wall or other structural support. Do not weld on cylinders.Radiation. Arc welding may produce ultraviolet, infrared, or light radiation.
14、 Always wearprotective clothing and eye protection to protect the skin and eyes from radiation. Shieldothers from light radiation from your welding operation.Special Precautions. In the following conditions when welding aluminum alloys: (1)High levels of fumes are produced when using the 5XXX (magne
15、sium-bearing) aluminumfiller metals. (2) The use of argon-based shielding gas blends results in the production ofozone, especially with 4XXX filler metals. The use of filtering masks or airline respiratorswill be required if it is determined that personnel are being exposed to excessivepollutants. C
16、aution must also be observed in the reaction between aluminum and certainsolvents and cleaners. Consult information provided by manufacturers for the necessarysafe practices in the use of their products. AWS also recommends a personal copy of “ArcWelding Safely“, “Fire Safety in Welding and Cutting“
17、, and “Safety in Welding, Cutting,and Allied Processes“. AWS publications may be purchased from the American Welding Society at http:/www.aws.org or by contacting the AWS at 800-854-7149.The Practical Reference Guide to Positioning4Intentionally Left BlankThe Practical Reference Guide to Positioning
18、5TABLE OF CONTENTSPage NoPractical Reference Guide to Positioning . 1Acknowledgments 2Basic Safety Precautions . 3I. Introduction 9II. Weldment Positioning Equipment 9A. Positioner Basics . 101. Determining the Center of Gravity. 102. Finding the Center of Gravity Experimentally. 123. Mounting Work
19、onto a Weldment Positioner. 144. Welding Chucks 175. Work Lead Connections . 196. Floor Anchors. 20B. Tilting-Rotating Positioners . 211. Selecting Positioner Capacity. 222. Tilt Torque 233. Rotation Torque 264. Swing Clearance. 275. Constant and Variable Speed Positioners . 276. Calculating Surface
20、 Speed 277. Speed Regulation 28C. Powered-Elevation Positioners . 29D. Drop-Center Tilting Positioners . 30E. Turntable Positioners. 311. Turntable Capacity Ratings 32F. Headstock and Tailstock Positioners . 331. Large Workpiece Inertia 342. Mounting Workpieces on Headstock and Tailstock Positioners
21、 . 353. Determining Swing Clearance . 384. Powered-Elevation Headstock and Tailstock Positioners . 39G Balancing Positioners . 391. Determining Load Capacity 392. Mounting the Work on Balancing Positioners 413. Making Minor Balance Adjustments . 414. Motorized Tables . 42III. Turning Rolls 42A. Fixe
22、d Centerline Turning Rolls . 43B. Adjustable Centerline Turning Rolls. 43The Practical Reference Guide to Positioning6Page NoC. Fit-Up Rolls 44D. Unitized-Frame Turning Rolls . 45E. Tilting Turning Rolls . 46F. Sling Style Rolls . 46G. Powered and Idler Rail Cars . 46H. Non-Cylindrical Work 47I. Pip
23、e Hold-Down Attachments 47J. Weight Capacity 48K. Rotation Power Ratings 48L. Tractive-Pull Ratings 48M. Included Angle 50N. Traction Calculation 51O. Selection of Turning Roll Wheel Materials 53P. Alignment . 53Q. Overturning Instability 55R. Setting Up Turning Rolls for Multiple Sections 57S. Shoc
24、k Loading 59T. Weld Joints 59IV. Welding Head Manipulators . 59A. Manipulator Selection . 60B. Lift 62C. Lift System Safety 64D. Reach 64E. Mast Rotation 64F. Car Travel . 65G. Powered Motions . 65H. Manipulator Load Capacity . 65I. Location and Mounting of Welding Head Manipulators 66J. Manipulator
25、 Equipment and Accessories . 66V. Side Beam and Carriage Equipment 67A. Side Beam and Carriage Equipment and Accessories 67The Practical Reference Guide to Positioning7Page NoVI. Safety Considerations. 69A. Environmental Interference 69B. Fastening Loads 70C. Avoiding Instability 70D. Other Safe Pra
26、ctices . 70E. Economic Considerations . 71F. Deposition Rates . 71G. Operator Factor and Set-Up Costs 71H. Welding Skill 71VII. Conclusion . 72VIII. Bibliography 72IX. Safety Documents 73List of TablesTable Page No.1 Determining Traction for Selected Included Angles 53List of FiguresFigure Page No.1
27、 Center of Gravity of a Solid Cube . 112 Center of Gravity of a Cylindrical Object 113 Finding the Center of Gravity of Small Workpieces 134A Finding the Center of Gravity of Large Workpieces by Balancingthem on a Pipe 134B Alternate View 135A Finding the Center of Gravity and Weight of a Workpiece
28、using a Hoist and Scale . 145B Alternate View 146 Effects of Tilting and Weldment Geometry on Positioner Fastener Requirements . 167 Use of a Three-Jaw Self-Centering Chuck. 188 Calculation of Total Tilt-Load Moment Requirements 199 Force of Inertia on the Base of a Positioner . 2010 Typical 135 Til
29、ting-Rotating Positioner with the Table in the Flat Position 2111 Examples of 45 - 90 and 135 Tilting-Rotating Positioner. 2212 Typical Tilting-Rotating Positioner 2413 Workpiece Mounted on Tilting-Rotating Positioner 2414 Capacity Plate Data for a Tilting-Rotating Positioner 2515 Rotation Axis of t
30、he Positioner as the Fulcrum . 2716 Diagram for Determining Revolutions Per Minute 2817 Powered-Elevation Positioner in the 135 Tilt-Down Position 29The Practical Reference Guide to Positioning8Figure Page No.18 Positioning Three Different Welds on a Spool-Shaped WorkpieceUsing an Elevating Position
31、er. 3019 Drop-Center Tilting Positioner . 3120 Typical Turntable Positioner. 3221 Turntable Capacity Ratings 3322 Typical Headstock and Tailstock Positioners . 3523 Headstock and Tailstock Positioner Ratings for Overhanging Load Capacity. 3524 Effect of Rotational Inertia of Large Workpieces. 3625 M
32、isalignment of Headstock and Tailstock Due to Rigid Mounting of Workpiece 3826 Pilot Mounting Method Overcomes Minor Misalignment . 3827 Universal-Pin Mounting System 3828 HTS Positioners with Powered Elevation Feature 3929 Intersection of Tilt and Rotation Axes on Balancing Positioner 4030 Determin
33、ing Load Capacity of a Balancing Positioner 4031 Installation of a Counterweight 4232 Fixed Centerline Turning Rolls 4333 Adjustable Centerline Turning Rolls 4434 Vessel Turning Rolls with Adjustable Centerline. 4435 Using Turning Rolls for Fit-U p Roll Adjustment 4536 Unitized-Frame Turning Rolls 4
34、537 Rail Cars for Powered and Idler Turning Rolls 4738 Turning Roll Setup for Non-Cylindrical Work. 4739 Tractive-Pull Ratings 4940 Comparison of Included Angle of Workpieces. 5041 Calculating Included Angle for Turning Rolls . 5242 Proper Setup for Turning Roll Alignment 5443 Conditions that Cause
35、End-Creep. 5544 Intentional Misalignment of Turning Rolls to Counteract End-Creep . 5545 Overturning Instability of Workpiece on Turning Rolls. 5646 Turning Roll Set Up for Workpiece with Multiple Sections 5847 Welding Head Manipulator and Multiple Turning Roll Alignment System. 5848 Bent Workpiece
36、Supported by Multiple Turning Roll Units 5849 Basic Motions of a Welding Head Manipulator . 6050 Large Model Welding Head Manipulator. 6151 Welding Head Manipulator with Welding Equipment Installed on BothEnds of the Boom 6152 Determining Extreme arc Positions for Reach and Lift 6153 Determining Ove
37、rall Height of a Vessel on Turning Rolls. 6354 Lift Range of a Welding-Head Manipulator . 6355 Determining Horizontal Boom Travel 6456 Basic Side Beam and Carriage Application 6857 Welding Lathe. 6858 Side Beam and Carriage Application . 69The Practical Reference Guide to Positioning9I. INTRODUCTION
38、This Practical Reference Guide describes the basic operation of weldment positionersand welding head manipulators and gives information on their selection and use.Weldment positioners hold and move a workpiece into the desired positions forwelding and other related operations. Welding head manipulat
39、ors hold and move thewelding head and welding torch as the weld is made. Positioners and welding headmanipulators can be used individually and in combination with each other or with otherequipment for manual, semi-automatic, mechanized, automated, or robotic weldingoperations. Weldment positioners a
40、nd welding head manipulators are particularlyuseful to reduce operator fatigue, increase welding speed, and reduce production timefor long weld joints, circumferential joints, and thick joints that require multiple weldpasses. They can help improve productivity, reduce costs, and improve weld qualit
41、y. CAUTION: THIS DOCUMENT INCLUDES GUIDELINES FOR THE OPERATION,SELECTION AND USE OF WELDMENT POSITIONERS AND WELDINGHEAD MANIPULATORS. CALCULATIONS OF LOADS AND FORCESON EQUIPMENT AND DESIGN OF MOUNTING METHODS FOREQUIPMENT, TOOLING, AND WORKPIECES ALWAYS SHOULD BEDONE BY A QUALIFIED ENGINEER OR BY
42、 THE MANUFACTURER OFTHE EQUIPMENT.II. WELDMENT POSITIONING EQUIPMENTPositioners are mechanical devices that support and move a workpiece to the desiredposition for welding and other related operations. Positioning equipment is available ina number of configurations, depending on the motions required
43、 to properly position thework. Weldment positioning equipment includes the following types: Balancing positioners that are designed to permit manual movement of theworkpiece. (See section: II.G.) Tilting-rotating positioners provide two powered axes of motion. (See section:II.B.) Powered elevation p
44、ositioners add powered vertical motion to tilting androtation motions of the table. (See section: II.C.) Drop-center tilting positioners are specially designed so that the surface of thetable is along or below the tilt axis. (See section: II.D.) Turntable positioners have tables that rotate about a
45、vertical axis but do not tilt.(See section: II.E.) Headstock and tailstock positioners provide motion to rotate a workpiece abouta horizontal axis and do not tilt. (See section: II.F.) Turning rolls hold and turn cylindrical parts about their horizontal axis. (Seesection: III.) The Practical Referen
46、ce Guide to Positioning10Selection of the proper type of positioning device depends on factors that are describedin the following sections of this document. These factors include the size, weight, andcomplexity of the workpiece as well as the number, location, and orientation of theweld joints. One
47、of the first decisions to be made is how many axes of motion will beneeded to properly position the weldment. Turning rolls, turntable positioners, andheadstock and tailstock positioners provide motion about only one axis. Tilting-rotating positioners provide two axes of motion. Three motion axes ar
48、e achieved byadding vertical motion to a tilting-rotating positioner, by combining more than one ofthe basic motion devices, or by the use of fixtures and tooling. This Practical Reference Guide also describes welding head manipulators. Whilewelding positioners can be used to move the workpiece, wel
49、ding head manipulatorsmove the welding process equipment to or over the work. Two types of welding headmanipulators are included in this document: Welding head manipulators consist of a vertical mast and horizontal boom to which the welding head is mounted. The manipulator provides two, three, four, or more axes of motion and can be mounted in a fixed position or on a traveling car. Welding side beams and carriages position the welding head in two axes and provide a single axis of motion, usually straight-line motion.A. Positioner BasicsThe first decision to make when selec
