Welding system with a real-time weld quality detection sensor

A welding gun for use in a welding system for real-time weld quality detection during resistance welding of a workpiece, the welding gun comprising:

• a cylinder;
• a piston and piston rod assembly mounted for axial movement within the cylinder, the piston rod having an end for affixing an electrode thereto, the end protruding from the cylinder;
• and
• a sensor assembly including a winding arrangement and a core, the winding arrangement and the core being mounted generally coaxially within the cylinder such that axial movement of the piston rod relative to the cylinder causes axial movement of the core relative to the winding arrangement to vary a length of core and winding arrangement overlap,
• wherein the core and the winding arrangement are configured to produce a full range linear output signal based on the length of core and winding arrangement overlap with the signal being formed by a single component that varies over the full range and defines piston rod position relative to the cylinder as the core moves over a full length of the winding arrangement to allow weld control logic receiving the sensor assembly output to control welding of the workpiece in real-time.

A welding gun for use in a welding system for real-time weld quality detection during resistance welding of a workpiece, the welding gun comprising:

• a cylinder;
• a piston and piston rod assembly mounted for axial movement within the cylinder, the piston rod having an end for affixing an electrode thereto, the end protruding from the cylinder;
• and
• a sensor assembly including a winding and a core, the winding and the core being mounted generally coaxially within the cylinder such that axial movement of the piston rod relative to the cylinder causes axial movement of the core relative to the winding to vary a length of core and winding overlap,
• wherein the sensor assembly produces an output signal based on the length of core and winding overlap to indicate piston rod position relative to the cylinder to allow weld control logic receiving the sensor assembly output to control welding of the workpiece in real-time, and wherein the sensor assembly core is made of a magnetic material such that the sensor output is a full range linear output that varies with magnetic material and winding overlap.

A welding gun for use in a welding system for real-time weld quality detection during resistance welding of a workpiece, the welding gun comprising:

• a cylinder;
• a piston and piston rod assembly mounted for axial movement within the cylinder, the piston rod having an end for affixing an electrode thereto, the end protruding from the cylinder;
• and
• a sensor assembly including a winding and a core, the winding and the core being mounted generally coaxially within the cylinder such that axial movement of the piston rod relative to the cylinder causes axial movement of the core relative to the winding to vary a length of core and winding overlap,
• wherein the sensor assembly produces an output signal based on the length of core and winding overlap to indicate piston rod position relative to the cylinder to allow weld control logic receiving the sensor assembly output to control welding of the workpiece in real-time, and wherein the sensor assembly core is made of a non-magnetic conducting material such that the sensor output is a full range linear output that varies with non-magnetic material and winding overlap.

A welding gun for use in a welding system for real-time weld quality detection during resistance welding of a workpiece, the welding gun comprising:

• a cylinder;
• a piston and piston rod assembly mounted for axial movement within the cylinder, the piston rod having an end for affixing an electrode thereto, the end protruding from the cylinder;
• and
• a sensor assembly including a winding and a core, the winding and the core being mounted generally coaxially within the cylinder such that axial movement of the piston rod relative to the cylinder causes axial movement of the core relative to the winding to vary a length of core and winding overlap,
• wherein the sensor assembly produces an output signal based on the length of core and winding overlap to indicate piston rod position relative to the cylinder to allow weld control logic receiving the sensor assembly output to control welding of the workpiece in real-time, and the winding is affixed to the cylinder, and the core is substantially cylindrical and is affixed to the piston rod such that the core encircles the winding.

A welding gun for use in a welding system for real-time weld quality detection during resistance welding of a workpiece, the welding gun comprising:

• a cylinder;
• a piston and piston rod assembly mounted for axial movement within the cylinder, the piston rod having an end for affixing an electrode thereto, the end protruding from the cylinder;
• a first winding having first and second ends, the first winding being axially mounted within the cylinder;
• a second winding having first and second ends, the second winding being axially mounted within the cylinder and being positioned so as to be flux coupled to the first winding, the first and second windings being configured to produce the flux coupling to each other with a flux coupling per unit length that varies as a function of axial position with respect to the first and second windings;
• and
• a magnetic core mounted within the cylinder such that axial movement of the piston rod relative to the cylinder causes axial movement of the core relative to the first and second windings to vary the effective flux coupling between the first and second windings,
• wherein the sensor assembly produces an output signal based on the effective flux coupling to indicate piston rod position relative to the cylinder to allow weld control logic receiving the sensor assembly output to control welding of the workpiece in real-time.

A welding gun for use in a welding system for real-time weld quality detection during resistance welding of a workpiece, the welding gun comprising:

• a cylinder;
• a piston and piston rod assembly mounted for axial movement within the cylinder, the piston rod having an end for affixing an electrode thereto, the end protruding from the cylinder;
• a first winding having first and second ends, the first winding being axially mounted within the cylinder and having a flux per unit length that varies as a function of axial position along the first winding;
• a second winding having first and second ends, the second winding being axially mounted within the cylinder and being positioned so as to be flux coupled to the first winding;
• and
• a magnetic core mounted within the cylinder such that axial movement of the piston rod relative to the cylinder causes axial movement of the core relative to the first and second windings to vary the effective flux coupling between the first and second windings,
• wherein the sensor assembly produces an output signal based on the effective flux coupling to indicate piston rod position relative to the cylinder to allow weld control logic receiving the sensor assembly output to control welding of the workpiece in real-time, and the second winding has a flux per unit length that varies as a function of axial position along the second winding.

A welding gun for use in a welding system for real-time weld quality detection during resistance welding of a workpiece, the welding gun comprising:

• a cylinder;
• a piston and piston rod assembly mounted for axial movement within the cylinder, the piston rod having an end for affixing an electrode thereto, the end protruding from the cylinder;
• a first winding having first and second ends, the first winding being axially mounted within the cylinder and having a flux per unit length that varies as a function of axial position along the first winding;
• a second winding having first and second ends, the second winding being axially mounted within the cylinder and being positioned so as to be flux coupled to the first winding;
• and
• a magnetic core mounted within the cylinder such that axial movement of the piston rod relative to the cylinder causes axial movement of the core relative to the first and second windings to vary the effective flux coupling between the first and second windings,
• wherein the sensor assembly produces an output signal based on the effective flux coupling to indicate piston rod position relative to the cylinder to allow weld control logic receiving the sensor assembly output to control welding of the workpiece in real-time, and the first and second windings are affixed to the cylinder, and the core is substantially cylindrical and is affixed to the piston rod such that the core encircles the first and second windings.

A welding gun for use in a welding system for real-time weld quality detection during resistance welding of a workpiece, the welding gun comprising:

• a cylinder;
• a piston and piston rod assembly mounted for axial movement within the cylinder, the piston rod having an end for affixing an electrode thereto, the end protruding from the cylinder;
• a first winding having first and second ends, the first winding being axially mounted within the cylinder and having a flux per unit length that varies as a function of axial position along the first winding;
• a second winding having first and second ends, the second winding being axially mounted within the cylinder and being positioned so as to be flux coupled to the first winding;
• and
• a magnetic core mounted within the cylinder such that axial movement of the piston rod relative to the cylinder causes axial movement of the core relative to the first and second windings to vary the effective flux coupling between the first and second windings,
• wherein the sensor assembly produces an output signal based on the effective flux coupling to indicate piston rod position relative to the cylinder to allow weld control logic receiving the sensor assembly output to control welding of the workpiece in real-time, and the sensor output signal is further based on an effective transformation ratio between the first and second windings.