Induction Shrink Fitting Assemble Connecting Rods With IGBT Heating Units

Objective Assemble connecting rods with a more accurate control of the heat
Material Rod has an OD of .9125” (23.18mm), knuckle has an ID of .9125” (23.18mm) with an interference of .0001” (.0025mm). Knuckle assembly is forged steel
Temperature 400 ºF (204 ºC)
Frequency 210 kHz
Equipment • DW-UHF- 3.5 kW induction heating system, equipped with a remote workhead containing two 1.0μF capacitors for a total of 0.5 μF
• An induction heating coil, designed and developed specifically for this application.
Process A six turn helical coil is used to heat the connecting rod for 13 seconds. The coil is perpendicular to the axis of the bore to promote even heating around the circumference. The connecting rod is then assembled with the piston for shrink fitting.
Results/Benefits Induction heating provides:
• More accurate control of heat vs a flame burner. Only heats knuckle, not the whole part.
• Lower temperature used to prevent discoloring.
• Increased productivity due to repeatability & ease of operation. A foot pedal & timer is used.
• No product contamination.