Sensing system for metal stamping forming tool
Sensing system for sensing the presence of a blank or part in the metal stamping forming tool. A blank holder assembly has a fixed bracket that is fixed to a lower die of the tool and a movable bracket that is moved with the upper die of the tool. A proximity sensor is attached to the movable bracket and senses the presence or absence of an edge of a blank or part during the course of a metal stamping forming operation.
Metal parts may be formed in metal stamping forming process in which a blank is formed in a series of steps into a finished part. Several presses may be arranged and aligned to sequently form a part. Parts may be initially drawn in a draw die, andthen may be spanked, trimmed, and punched in subsequent press forming operations. The metal stamping parts may also be made in a transfer press in which a die having multiple stations is operated by a single press that has a die with multiple stations thatperform prescribed steps in sequence to form a finished part.
Sensors are used in metal stamping forming processes to control the operation of one or more presses. Sensors may be provided in the dies and also may be provided on loaders, shuttles, conveyors and other material handling equipment that is used toload blanks or partially formed parts. Different types of sensors may be used in metal stamping forming processes include limit switches, reed switches, Hall Effect switches, or proximity sensors.
One application for a sensor used in a metal stamping forming tool is as a blank or part presence detector. A part presence detector is used to detect whether a metal stamping blank or a partially formed part is in the proper position for performingthe next operation. If a part presence detector provides a false indication that a part is in the desired position the part, die, or tool may be damaged if, in fact, the part is out of location. If a part is mishit by a metal stamping forming tool thepart may be scrapped and the tool may be damaged. If a part presence detector indicates the presence of a panel when no panel is in the tool, the tool may be damaged. If a metal stamping forming tool is cycled without performing the desired the operationon the part, the number of parts produced may be inaccurately reflected.
Variations in the strength or resiliency of a blank or part may result in unexpected spring back in the part after a forming operation. Bowed blanks or parts may be difficult to sense by a part presence detector since the blank may be bowed inan area where the sensor is oriented to detect the presence of the blank.
High speed production lines have short cycle times that afford less time for a blank or part to nest within the tool. Less time is also available for sensing that the part is properly nested in the tool. Some part shapes present challenges forlocating sensors that accurately and quickly sense the location of a blank or part.
In some instances, it would be advantageous to provide a part presence detector that senses the presence of a part throughout a forming process even as the edge of a part moves during the drawing or forming cycle.
There is a need for an accurate system for sensing the presence of a blank or metal stamping part. There is a further need for a part sensing system that provides a quick response and is capable of providing an accurate indication of the presence of a partthroughout a forming cycle. By providing an improved part presence detecting system a reduction in false signals from the part sensing system can result in reduced downtime and scrap.
Processing your request, Please wait....
