Containment device for a laser head and associated manufacturing method

A method of laser welding a workpiece using a laser containment device operatively connected to a laser welding head operative to emit a laser beam, the method comprising:

• encircling with a peripheral chamber an opening in a first chamber of said containment device, said opening being operative to accommodate said laser beam, said peripheral chamber being located at a working end of said laser containment device;
• sealing said peripheral chamber of said laser containment device from said first chamber, said sealing occurring against the workpiece;
• creating a differential pressure zone in said peripheral chamber using a differential pressure generator connected to said peripheral chamber, said differential pressure generator being operative to create a pressure value within said peripheral chamber that is higher than an ambient pressure outside said peripheral chamber, wherein said differential pressure zone being at a higher pressure than an ambient pressure outside an outer shell of said laser containment device;
• detecting a pressure value within said peripheral chamber using a pressure sensor, said pressure sensor being in communication with said peripheral chamber;
• manipulating said laser welding head and said laser containment device to follow a joint to be welded in the workpiece using a computer-controlled robotic arm;
• generating a signal indicative of said pressure value within said peripheral chamber using said pressure sensor when said laser welding head and said laser containment device are manipulated to follow the joint to be welded in the workpiece, said pressure sensor being operative to send said signal to a controller;
• determining a predetermined pressure threshold using said controller, said predetermined pressure threshold being based on an acceptable range of said detected pressure value from an initial pressure value, said initial pressure value being indicative of an adequate seal;
• comparing said detected pressure value with said predetermined pressure threshold using said controller when said laser welding head and said laser containment device are manipulated to follow the joint to be welded in the workpiece;
• and
• using said controller for deciding whether or not to emit the laser beam toward the workpiece based on a result of said comparison when said laser welding head and said laser containment device are manipulated to follow the joint to be welded in the workpiece, said controller being operative to send a laser beam operation signal to said laser welding head when said detected pressure value is within said predetermined pressure threshold and to stop sending said laser beam operation signal to said laser welding head when said detected pressure value crosses said predetermined pressure threshold.

A laser welding equipment for welding a workpiece, the laser welding equipment comprising:

• a manipulator;
• a laser welding head operative to emit a laser beam to weld the workpiece along the joint;
• a laser containment device for containing a laser beam emitted by the laser welding head, the laser containment device connected to said laser welding head, said laser containment device having:
• an outer shell at least partially enclosing a containment chamber, said outer shell receiving said laser welding head within said containment chamber and distal a bottom face of said outer shell;
• a laser beam output port in said bottom face operative to let the laser beam reach the workpiece;
• an inner wall;
• a peripheral chamber defined in between said outer shell and said inner wall, said peripheral chamber being open at said bottom face, said peripheral chamber encircling said laser beam output port, wherein said peripheral chamber is split into at least two sub-chambers by at least two dividers, each one of said at least two dividers being equipped with a third seal proximate said bottom face;
• an inner seal mounted to said inner wall proximate said bottom face, said inner seal being operative to contact the workpiece;
• and
• an outer seal mounted to said outer shell proximate said bottom face, said outer seal being operative to contact the workpiece;
• a first pressure sensor adapted to detect a first differential pressure within a first sub-chamber of the at least two sub-chambers of said peripheral chamber and to generate a signal indicative of a value of said first differential pressure;
• a second pressure sensor adapted to detect a second differential pressure within a second sub-chamber of the at least two sub-chambers of said peripheral chamber and to generate a signal indicative of a value of said second differential pressure;
• a differential pressure generator connected to said peripheral chamber, said differential pressure generator being operative to generate said differential pressure at a value that is higher than an ambient pressure outside said peripheral chamber;
• a controller operative to selectively operate said laser welding head based on said signal received from said first pressure sensor and said signal received from said second pressure sensor;
• and
• wherein said manipulator is operative to manipulate said laser welding head and said containment device to follow the joint to be welded in the workpiece during a laser welding operation;
• wherein the controller determines an average value of the differential pressure based on the value of the first differential pressure and the value of the second differential pressure;
• and
• wherein the controller compares the average value of the differential pressure to a predetermined pressure threshold to determine whether the average value of the differential pressure crosses the predetermined pressure threshold.