Method of magnetic pulse welding an end fitting to a driveshaft tube of a vehicular driveshaft

A method of joining an end fitting and a driveshaft tube of a vehicular driveshaft assembly comprising:

• providing a hollow driveshaft tube having an open first end, the driveshaft tube having an inner surface defined by a first inner diameter;
• providing a tubular sleeve having an outer surface defined by a second diameter smaller than the first diameter and an inner surface defined by a third diameter smaller than the second diameter;
• providing an end fitting having a neck with an outer surface defined by a fourth diameter smaller than the third diameter;
• providing an electrical inductor;
• disposing the neck of the end fitting into the tubular sleeve so that a first annular gap is formed between the neck and the tubular sleeve;
• disposing the sleeve into the open end of the driveshaft tube so that a second annular gap is formed between the tubular sleeve and the driveshaft tube;
• disposing the first end of the driveshaft tube containing the sleeve and neck into the inductor;
• and
• energizing the inductor to generate electromagnetic forces to collapse the driveshaft tube onto the tubular sleeve and the tubular sleeve onto the neck at a high velocity, thereby welding the driveshaft tube is to the sleeve and the tubular sleeve to the neck.

A method of joining an end fitting and a driveshaft tube of a driveshaft assembly comprising:

• welding with magnetic pulse welding a generally tubular sleeve of transition material to the outer surface of a neck of an end fitting;
• reducing the thickness of the transition material;
• and
• welding a hollow driveshaft tube to the transition material using magnetic pulse welding to join the driveshaft tube to the end fitting.

A method of securing components of a driveshaft assembly comprising:

• providing a driveshaft tube having an open end;
• providing an end fitting having a neck, where the neck has a frustoconical surface and a shoulder, thereby defining a cavity;
• disposing the neck of the end fitting into the open end of the driveshaft tube so that an annular gap is provided between the neck and the driveshaft tube, with the end of the driveshaft tube being generally axially aligned with the shoulder;
• providing a shield to block the emission of contaminants escaping from the cavity along the shoulder;
• and
• welding the driveshaft tube to the end fitting.

A method of securing components of a driveshaft assembly using magnetic pulse welding apparatus including an inductor coil for magnetic pulse welding a driveshaft to an end fitting, a capacitor for storing energy, a discharge switch for discharging the stored energy in the capacitor to the inductor coil to weld the driveshaft to the end fitting, and a charging circuit for charging the capacitor, where the discharge switch is capable of self breakdown, the method comprising:

• progressively evacuating the gases surrounding the discharge switch, where the evacuation progressively increases the voltage at which the discharge switch will self breakdown;
• charging the capacitor at a rate which maintains the voltage of the capacitor at a level below the self breakdown voltage of the discharge switch;
• and
• discharging the capacitor through the discharge switch after the voltage reaches a predetermined voltage.

A method of securing components of a driveshaft assembly using magnetic pulse welding apparatus including an inductor coil for magnetic pulse welding a driveshaft to an end fitting, a capacitor for storing energy, a discharge switch for discharging the stored energy in the capacitor to the inductor coil to weld the driveshaft to the end fitting, and a charging circuit for charging the capacitor, where the discharge switch is capable of self breakdown, the method comprising:

• assembling the driveshaft and end fitting in preparation for welding them together;
• charging the capacitor to a voltage equal to a predetermined threshold level;
• inserting the assembled driveshaft and end fitting into the inductor coil after the voltage of the capacitor has reached the predetermined level;
• and
• welding the assembled driveshaft and end fitting into a driveshaft assembly.