cooling & mechanical systems. lesson objectives when you finish this lesson you will understand:...

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Cooling & Mechanical Systems

Cooling & Mechanical Systems

Lesson ObjectivesWhen you finish this lesson you will understand:• System for cooling critical components• Systems for exerting electrode Force• Typical Applications

Learning Activities1. View Slides; 2. Read Notes, 3. Listen to lecture4. Do on-line

workbook5. Do Homework

KeywordsCooling System, Mechanical System, Fixed Stroke, Adjustable Stroke, Retractable Stroke, Valves, Rocker Arm, Press Type Welder, Servo Gun

Machines and Equipment• Cooling System

• Mechanical System– Force generation system

• Pneumatic/Hydraulic system

• Motor or foot-operated system

– Electrode application system• Rocker arm or pinch type

• Press or direct action type

• Portable system

• Electrical System– Single-phase system

– Single-phase rectified system

– Three-phase rectified system

– Frequency changer system

– Frequency inverter system

Cooling System• Function:

– Prevent overheating of the components of the welding machine

• Components requiring cooling include:– The welding contactor (ignitron tubes or SCRs)– The welding transformer– The welding electrodes– Power cables (portable welding gun only)

A. Saabria, WE651 Lab Report1999

Machines and Equipment• Cooling System

• Mechanical System– Force generation system

• Pneumatic/Hydraulic system

• Motor or foot-operated system

– Electrode application system• Rocker arm or pinch type

• Press or direct action type

• Portable system

• Servo System

• Electrical System– Single-phase system

– Single-phase rectified system

– Three-phase rectified system

– Frequency changer system

– Frequency inverter system

Pneumatic/Hydraulic System

K

X

A

A

A

L

P

B

R

P

B

C

B

R

P

H

L

M

(a) Fixed Stroke (b) Adjustable Stroke (c) Adjustable, Retractable Stroke

Electrode Force: F=AP

Pneumatic Cylinder Valves

Symbol Physical Symbol Physical

(a) Two-Way Valve (b) Three-Way Valve with Single Acting Cylinder

Pneumatic Cylinder Valves (CONT.)

P1

P1

P2

P2

(c) Four-Way Valve with Double- Acting Cylinder

(d) Four-Way, Five Port Valve with Double-Acting Cylinder

Hirsch, R & Leibovitz, R, “Improved Weld Quality and Electrode Life in Resistance Welding” Practical Welding Today, Nov-Dec, 1997

Electronic Pressure System

Motor or Foot-Operated System

F

Rocker Arm

Anvil

x SpringAssembly

Pivot Point

X

Y

Rocker Arm Machines

Air in

[Reference: Resistance Welding Manual, p.16-2, RWMA]

X Y

Press Type Welding Machines

[Reference: Resistance Welding Manual, p.16-5, RWMA]

C - Type Servo Spot Gun

Slavick, “Overview of Servo-Driven Weldguns..”AWS Sheet Metal Conf. VIII, 1998

Slavick, “Overview of Servo-Driven Weldguns..”AWS Sheet Metal Conf. VIII, 1998

X - Type Servo Spot Gun

Slavick, “Overview of Servo-Driven Weldguns..”AWS Sheet Metal Conf. VIII, 1998

Portable System

[Reference: Automotive Manufacturing, April 1996, p.5, SAE]

Mechanical Systems

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