Patent ID: 9738063
Date: 2017-08-22
CPC Classifications: B29C,B29L,B32B,G01N

Claim:
1. A method of manufacturing a welded resin article by laser-welding together a first resin member which allows laser light to pass therethrough and a second resin member which absorbs the laser light, the method comprising: (a) bringing the first resin member and the second resin member into contact with each other or close to each other; (b) applying the laser light to a surface of the second resin member from a side where the first resin member is present, while moving the laser light relative to the first and second resin members; (c1) obtaining a value corresponding to the intensity of infrared light emitted from the surface that is heated as a result of applying the laser light, the value being obtained from individual ones of a plurality of locations on the surface as a result of relative movement of the laser light; (d) successively calculating a section average which is the average of a predetermined number of successive values, the number being equal to or greater than 2, among the values obtained from the plurality of locations on the surface and each corresponding to the intensity of the infrared light; (e) successively calculating a deviation judgment value representing the degree of deviation of the value corresponding to the intensity of the infrared light from the section average; and (f) successively judging whether or not the deviation judgment value falls within a predetermined judgment threshold range and judging that a weld state at the surface is good when the deviation judgment value falls within the judgment threshold range, wherein the step (f) includes: defining as a peculiar deviation judgment value a deviation judgment value which does not fall within the predetermined judgment threshold range and calculating an added deviation judgment value by adding together the peculiar deviation judgment value, one or more deviation judgment values preceding the peculiar deviation judgment value and one or more deviation judgment values following the peculiar deviation judgment value; and judging whether the weld state at the surface is good or bad by comparing the added deviation judgment value with a predetermined deviation judgment threshold.