HIGH FREQUENCY HEATING METHOD OF BOLT WITH HOLE

Japanese Patent JP3396344

B2

PROBLEM TO BE SOLVED: To hold stress acted on the small diameter hole surface of a bolt with a hole within the elastic stress when the maximum power is supplied to a heater, and suppress a life consumption by fatigue by setting the maximum heat stress (σmax) to the value of proof stress (σys) and less of a bolt material in the maximum reach temperature (Tmax).
SOLUTION: A temperature difference ΔT(=Tmax-Tmean) between the maximum reach temperature Tmax of the inner surface of a metal bolt at the time of heating and the average temperature Tmeans of the whole of a bolt sectional surface, is found out by using a next formula. σmax≥EαΔT/(1-ν), ΔT≤ΔTmax<ΔT0, E is the Young's modulus, α is a thermal expansion coefficient, ν is a Poisson's ratio, they are a value which is rated by the material of the metal bolt. Numerical analysis is carried out by a finite element method by using Tmax and ΔT which is found out by above formula and a bolt size as a data which is known beforehand, and the maximum input power supplied to a heater at the time of heating of the metal bolt is found out.

WO/2016/135220	SYSTEM FOR TIGHTENING TIE RODS OF A PRESS
JPH09170614	METHOD AND APPARATUS FOR REDUCING ROTATIONAL RESISTANCE OF BOLT
WO/2005/080804	HYDRAULIC NUT AND METHOD OF USE THEREOF

Katsuhiko Takita
Takayuki Kawano
Takijiro Shimamoto
Koichi Ide

JP20948295A

April 14, 2003

August 17, 1995

Click for automatic bibliography generation  

MITSUBISHI HEAVY INDUSTRIES,LTD.

F16B31/04; B23P19/06; C21D1/42; C21D9/00; F01D25/10; F01D25/24; H05B6/10; (IPC1-7): F16B31/04; B23P19/06; C21D1/42; C21D9/00; F01D25/10; F01D25/24; H05B6/10

JP7217626A
JP81458A
JP6256610A
JP6427824A
JP8144712A
JP526005A
JP59171038U
JP1141305U

Arata Ishikawa

Previous Patent: BOARD

Next Patent: PLASMA GENERATOR