# US 12,214,438 B2 · Spatter detection method

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- Number: US 12,214,438 B2
- Document ID: US12214438B2
- Status: Granted
- Kind: B2
- Application number: 18/180,872
- Filed: 2023-03-09
- Published: 2023-10-05
- Granted: 2025-02-04
- Earliest claimed: 2022-03-31
- Assignees: Honda Motor Co., Ltd.
- Applicants: Honda Motor Co., Ltd.
- Inventors: Hiroki Toyoda; Xihao Tan; Hitoshi Saito; Shinya Watanabe
- Web page: https://patentgrep.com/patent/US12214438B2

## CPC

- B23K 11/115: {by means of two electrodes placed opposite one another on both sides of the welded parts}
- B23K 11/257: {the measured parameter being an electrical current}
- B23K 31/125: {Weld quality monitoring}
- G01R 29/023: {Measuring pulse width}
- B23K: SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12)

## Abstract

A spot welding method includes supplying a welding current having a pulse-shaped waveform to a workpiece by alternately executing a step of maintaining the welding current within a set peak current range and a step of decreasing the welding current from the peak current range toward a bottom current and then increasing the welding current toward the peak current range when an effective value of the welding current reaches a set target range for a plurality of cycles. The spatter detection method includes measuring a pulse width IW(1), IW(2), . . . in each cycle of the pulse-shaped waveform and detecting the occurrence of spatter when a pulse width difference D(M)=IW(M)−IW(M−1) between a pulse width IW(M) in a target cycle (M-th cycle) and a pulse width IW(M−1) in a cycle immediately before the target cycle exceeds a width threshold value Dth.

## Claims

### Claim 1

A spatter detection method for detecting an occurrence of spatter in a spot welding method for joining a workpiece by supplying a welding current, wherein
the spot welding method includes supplying the welding current having a pulse-shaped waveform by alternately executing a step of maintaining the welding current within a set peak current range and a step of decreasing the welding current from the peak current range toward a bottom current and then increasing the welding current toward the peak current range when an effective value of the welding current reaches a set target range for a plurality of cycles,
the spatter detection method comprising measuring a pulse width in each cycle of the pulse-shaped waveform and detecting the occurrence of spatter when a difference between the pulse width in a target cycle and the pulse width in a cycle immediately before the target cycle exceeds a predetermined width.

### Claim 2 (depends on 1)

The spatter detection method according to claim 1, further comprising, when the occurrence of spatter is detected, estimating a quality of a product manufactured by welding the workpiece based on a timing at which the occurrence of the spatter is detected.

### Claim 3 (depends on 1)

The spatter detection method according to claim 1, wherein the spot welding method includes fixing a slope time, which is a combination of a current rise time until the welding current reaches the peak current range from the bottom current and a peak holding time during which the welding current is maintained within the peak current range.

### Claim 4 (depends on 2)

The spatter detection method according to claim 2, wherein the spot welding method includes fixing a slope time, which is a combination of a current rise time until the welding current reaches the peak current range from the bottom current and a peak holding time during which the welding current is maintained within the peak current range.