Continuous duty press monitoring system

A press operation monitoring method comprising the steps of:

• activating a press to perform a stamping operation;
• monitoring deformation of a frame of the press relative to opposed first and second, spaced apart ends of a rod member, the first spaced apart end being mounted to the frame at a first mounting point so as to allow axial displacement of the rod corresponding to frame movement at the first mounting point, and the second spaced apart end being mounted to the frame at a second mounting point such that the rod axis is slidable relative to the second mounting point;
• generating, via a linear variable displacement transducer secured to the second spaced apart end, a press deflection signal representative of the deformation induced by operation of the press;
• automatically calibrating the press deflection signal to a base level prior to the step of activating;
• and
• generating a display signal in accordance with the press deflection signal.

A press operation data acquisition device comprising:

• securing means adapted for securing a frame of the press relative to opposed first and second, spaced apart ends of a rod member, the first spaced apart end being mounted to the frame at a first mounting point so as to allow axial displacement of the rod corresponding to frame movement at the first mounting point, and the second spaced apart end being mounted to the frame at a second mounting point such that the rod axis is slidable relative to the second mounting point;
• a linear variable displacement transducer including a coil portion secured to the frame at the second mounting, and
• a core portion secured to the rod at the second spaced part end such that a magnetic flux generated by application of current to the coil portion is affected by a relative position of the core portion thereto;
• means for providing an electric current to the coil portion;
• sensing means continuously sensing the magnetic flux during operation of the associated press by monitoring of current in the coil portion;
• means for acquiring an analog flux level signal representative of sensed magnetic flux from the sensing means;
• digitizing means for digitizing the flux level signal to form a digitized flux level signal;
• filter means for filtering the digitized flux level signal to form a position signal;
• calibrating means adapted for automatically calibrating the position signal to a base level prior to completing a press cycle of the associated press;
• and
• means for calculating a press deflection signal representative of a relative position of the coil portion to the core portion in accordance with the position signal.

A data acquisition apparatus for a metal forming machine, comprising:

• a linear variable displacement transducer including a coil portion movably disposed relative to a core portion such that magnetic flux generated by current impressed on the coil portion is influenced by a position of the core portion relative thereto;
• securing means adapted for securing the core portion to a first portion of a housing of an associated metal forming machine and the coil portion to spaced apart portions of the housing of the associated metal forming machine such that compression and expansion of the housing will influence a relative position of the core portion to the coil portion;
• means for providing an electric current to the coil portion;
• means continuously sensing the magnetic flux induced by operation of the associated metal forming machine by monitoring of current in the coil portion;
• position signal generating means for periodically generating a position signal representative of a relative position of the coil portion to the core portion in accordance with sensed magnetic flux;
• and
• calibrating means adapted for automatically calibrating the position signal to a base level prior to completing a cycle of the associated metal forming machine;
• means for generating a deflection signal in accordance with the position signal.

A monitoring method for a metal forming machine comprising the steps of:

• activating a metal forming machine to perform a metal forming operation;
• monitoring deformation of a frame of the metal forming machine relative to opposed first and second spaced apart ends of a rod member, the first spaced apart end being mounted to the frame at a first mounting point so as to allow axial displacement of the rod corresponding to frame movement at the first mounting point, and the second spaced apart end being mounted to the frame at a second mounting point such that the rod axis is slidable relative to the second mounting point;
• generating, via a linear variable displacement transducer secured to the second spaced apart end, a deflection signal representative of the deformation induced by operation of the metal forming machine;
• automatically calibrating the deflection signal to a base level prior to the step of activating;
• and
• generating a display sign in accordance with the deflection signal.

A data acquisition device for a metal forming machine comprising:

• securing means adapted for securing a frame of the metal forming machine relative to opposed first and second, spaced apart ends of a rod member, the first spaced apart end being mounted to the frame at a first mounting point so as to allow axial displacement of the rod corresponding to frame movement at the first mounting point, and the second spaced apart end being mounted to the frame at a second mounting point such that the rod axis is slidable relative to the second mounting point;
• a linear variable displacement transducer including
• a coil portion secured to the frame at the second mounting, and
• a core portion secured to the rod at the second spaced part end such that a magnetic flux generated by application of current to the coil portion is affected by a relative position of the core portion thereto;
• means for providing an electric current to the coil portion;
• sensing means continuously sensing the magnetic flux during operation of the associated metal forming machine by monitoring of current in the coil portion;
• means for acquiring an analog flux level signal representative of sensed magnetic flux from the sensing means;
• digitizing means for digitizing the flux level signal to form a digitized flux level signal;
• filter means for filtering the digitized flux level signal to form a position signal;
• calibrating means adapted for automatically calibrating the position signal to a base level prior to completing a cycle of the associated metal forming machine;
• and
• means for calculating a deflection signal representative of a relative position of the coil position of the coil portion to the core portion in
• accordance with the position signal.