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