US 11,850,674 B2
Spot welding method
Shinya Watanabe, Tochigi (JP); Hitoshi Saito, Tochigi (JP); Xihao Tan, Tochigi (JP); and Shinyu Hirayama, Tochigi (JP)
Assigned to HONDA MOTOR CO., LTD., Tokyo (JP)
Appl. No. 17/040,592
Filed by HONDA MOTOR CO., LTD., Tokyo (JP)
PCT Filed Mar. 23, 2018, PCT No. PCT/JP2018/011770
§ 371(c)(1), (2) Date Sep. 23, 2020,
PCT Pub. No. WO2019/180923, PCT Pub. Date Sep. 26, 2019.
Prior Publication US 2021/0069820 A1, Mar. 11, 2021
Int. Cl. B23K 11/11 (2006.01)
CPC B23K 11/115 (2013.01) 9 Claims
OG exemplary drawing
 
1. A spot welding method comprising:
joining, using pulse current, a laminate which comprises three or more superimposed metal plates, which is formed so that at least one metal plate among the three or more metal plates is different in thickness from the other metal plates, and in which a plate thickness ratio of a total thickness of the three or more metal plates to a thickness of the at least one metal plate is from 3.5 to 10, wherein
the pulse current has a pulsed waveform in which a peak state and a no-peak state are alternately set, the peak state being a state where peak maintaining control is started at a point when the pulse current reaches from a value lower than a lower limit value of a set peak current range to an upper limit value of the peak current range, and is performed as much as a predetermined number of times until the pulse current decreases from the upper limit value of the peak current range to the lower limit value of the peak current range and again increases to the upper limit value of the peak current range, and the no-peak state being a state where after the peak maintaining control is performed as much as the predetermined number of times, the pulse current decreases from the upper limit value of the peak current range to bottom current which is set, and again increases to the upper limit value of the peak current range,
the upper limit value of the peak current range is set to 10.6 kA or more,
a peak duration which is a duration of the peak state is set to 0.9 ms or less, and
a no-peak duration which is a duration of the no-peak state is set to be from 4 ms to 13.6 ms, and from 5 times to 87 times as much as the peak duration.