Apparatus and method for securing a clinch nut to a sheet of advanced high strength steel

A system to secure a clinch nut to a sheet of advanced high strength steel (AHSS) comprising:

• the clinch nut;
• the sheet of AHSS;
• a joining assembly adjacent to where the AHSS sheet is positioned;
• the joining assembly including a base and an indexing member mounted on the base for movement parallel to the AHSS sheet;
• and the indexing member having a heating opening and a clinch die spaced from each other along a direction parallel to the AHSS sheet;
• an actuator that moves the indexing member between a heating position where its heating opening is located at a work location of the AHSS sheet and a joining position where its clinch die is located at the work location of the AHSS sheet;
• a laser assembly to fire a laser beam through the heating opening of the indexing member while in the heating position to provide heating of the work location of the AHSS sheet;
• a nut ram to which the clinch nut and a plurality of clinch nuts, each of which has a threaded hole, are fed, and the nut ram being aligned with the clinch die when the indexing member is in the joining position to pierce a hole through the heated work location of the AHSS sheet and attach the clinch nut to the AHSS sheet at the heated work location of the AHSS sheet whereby the heated work location of the AHSS sheet flows into an undercut of the clinch nut, so a threaded fastener can be connected to the AHSS sheet;
• a controller configured to operate the joining assembly and the nut ram;
• a slideway that mounts the indexing member on the base for rectilinear movement by the actuator between the heating position and the joining position or a pivotal connection that mounts the indexing member on the base for pivotal movement by the actuator between the heating position and the joining position;
• wherein the actuator moves the indexing member between the heating position and the joining position in 0.3 seconds or less;
• wherein the joining assembly comprises:
• an enclosure defining a chamber containing laser beam radiation partially defined by the base and from which the laser assembly fires the laser beam through an opening in the base and thence through the heating opening in the indexing member while in the heating position to provide the heating of the work location of the AHSS sheet, and
• a detector assembly operated by the controller to only permit operation of the laser assembly when the AHSS sheet is in contact containing laser beam radiation with the indexing member around its heating opening when the indexing member is in the heating position;
• wherein the detector assembly comprises a source of pressurized gas to provide pressurized gas to the chamber and also includes a detector to detect gas flow from the source through the chamber to detect whether the AHSS sheet is in contact that contains laser beam radiation with the indexing member around its heating opening;
• a temperature sensor to sense the temperature of the AHSS sheet at the work location of the AHSS sheet;
• a C frame having one end that supports the joining assembly and having another end that supports the nut ram that cooperates with the clinch die under the operation of the controller to provide the attachments of the clinch nuts to the AHSS sheet;
• and
• a robot that moves the C frame under operation of the controller to provide attachments of the clinch nuts to the AHSS sheet at different locations.

A system to secure a sheet of advanced high strength steel (AHSS) comprising:

• the clinch nut;
• the sheet of AHSS;
• a forming assembly adjacent to where the AHSS sheet is positioned, the forming assembly comprising:
• a base,
• an indexing member mounted on the base for movement parallel to the AHSS sheet, wherein the indexing member has a heating opening, and
• a die spaced from the indexing member along a direction parallel to the AHSS sheet;
• an actuator that moves the indexing member between a heating position where its heating opening is located at a work location of the AHSS sheet and a forming position where its die is located at the work location of the AHSS sheet;
• a heating assembly to provide heating of the work location of the AHSS sheet;
• a ram aligned with the die when the indexing member is in the forming position to pierce a hole through the AHSS sheet to attach the clinch nut to the AHSS sheet at the heated work location of the AHSS sheet whereby the heated work location of the AHSS sheet flows into an undercut of the clinch nut;
• a controller configured to operate the forming assembly and the ram;
• a slideway that mounts the indexing member on the base for rectilinear movement by the actuator between the heating position and the forming position or a pivotal connection that mounts the indexing member on the base for pivotal movement by the actuator between the heating position and the forming position;
• wherein the actuator moves the indexing member between the heating position and the forming position in 0.3 seconds or less;
• a temperature sensor to sense the temperature of the AHSS sheet at the work location of the AHSS sheet;
• a C frame having one end that supports the forming assembly and having another end that supports the ram that cooperates with the die under the operation of the controller;
• and
• a robot that moves the C frame under operation of the controller to provide forming of the AHSS sheet at different locations.