Welding system monitoring and control system
First Claim
1. A welding control system for a pulse welder having a welding cycle including heat portions and cool portions, the pulse welder including at least one welding head, a source of welding pulses of preselected duration, a standard control circuit for generating a standard connected between the source and the welding head for controlling the application of alternate of the head and cool portions to a welding load by controlling the number of welding pulses fed to the load during the heat portion and the duration of the cool portion, the standard control circuit including means for generating a series of clock pulses for controlling the duration of the heat and cool portions of the welding cycle of the load by counting a preselected number of clock pulses in the heat and cool portions of the cycle, the improvement comprising means connected to the standard control circuit for altering the duration of the heat and/or cool portions of the cycle counted by the standard control including sensing means for sensing a first set of voltage and current characteristics flowing in the load during a heat portion, means for generating a varying standard impedance characteristic from said sensed first set of voltage and current characteristics flowing in the load, an interface circuit connected to the current and voltage sensing means and said impedance characteristic generating means for feeding the voltage and current signals to said impedance characteristic generating means, said sensing means sensing and feeding a second set of voltage and current characteristics to said impedance characteristic generating means, said generating means generating a second impedance characteristic from said second set, and means for comparing said second impedance characteristics of the weld with the standard impedance characteristic and generating a pulse by pulse altering signal when the sensed impedance characteristic is not within the generated standard characteristics, said altering means connected to the standard control for altering the heat and/or cool portions to maintain said second impedance characteristic within limits of said standard characteristic.
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Accused Products
Abstract
A monitoring and control system for use in conjunction with a pulse type welder which utilizes a computer to calculate the impedance characteristics of a weld and compare these characteristics to a preselected set of characteristics to determine if a quality weld has been made. The system then controls the heat and cool time to increase or decrease the tmeperature of the weld and thus control the size of the weld nugget. The monitoring control system is utilized in conjunction with a standard pulse welding control system, which standard system provides a series of heat impulses followed by a series of cool impulses, this cycle being repeated for a preselected number of cycles. The monitoring and control system senses the voltage and current in the welding load and feeds this data to a computer which, in turn, calculates the impedance of the weld. This calculation is then compared to a predetermined set of standards which are evolved as a result of processing a preselected number of previous welds, and corrections are made to assure the weld quality. If the temperature of the weld has not been sufficiently elevated, the number of impulses in the cool portion of the cycle, and thus the cool time, is reduced until the weld meets the set standards. On the other hand, if the temperature exceeds the standard, the number of heat impulses, and thus the heat time, is reduced.
22 Citations
58 Claims
- 1. A welding control system for a pulse welder having a welding cycle including heat portions and cool portions, the pulse welder including at least one welding head, a source of welding pulses of preselected duration, a standard control circuit for generating a standard connected between the source and the welding head for controlling the application of alternate of the head and cool portions to a welding load by controlling the number of welding pulses fed to the load during the heat portion and the duration of the cool portion, the standard control circuit including means for generating a series of clock pulses for controlling the duration of the heat and cool portions of the welding cycle of the load by counting a preselected number of clock pulses in the heat and cool portions of the cycle, the improvement comprising means connected to the standard control circuit for altering the duration of the heat and/or cool portions of the cycle counted by the standard control including sensing means for sensing a first set of voltage and current characteristics flowing in the load during a heat portion, means for generating a varying standard impedance characteristic from said sensed first set of voltage and current characteristics flowing in the load, an interface circuit connected to the current and voltage sensing means and said impedance characteristic generating means for feeding the voltage and current signals to said impedance characteristic generating means, said sensing means sensing and feeding a second set of voltage and current characteristics to said impedance characteristic generating means, said generating means generating a second impedance characteristic from said second set, and means for comparing said second impedance characteristics of the weld with the standard impedance characteristic and generating a pulse by pulse altering signal when the sensed impedance characteristic is not within the generated standard characteristics, said altering means connected to the standard control for altering the heat and/or cool portions to maintain said second impedance characteristic within limits of said standard characteristic.
- 52. In a welding control system for a pulse welder having a welding cycle including heat portions and cool portions, a source of welding pulses of preselected duration, a pulse welder including at least one welding head, a standard control circuit for generating a standard connected between the source and the welding head for controlling the application of alternate of the heat and cool portions to a welding load by controlling the number of welding pulses fed to the load during the heat portion and the duration of the cool portion, the standard control circuit including means for generating a series of clock pulses for controlling the duration of the heat and cool portions of the welding cycle of the load by counting a preselected number of clock pulses in the heat and cool portions of the cycle, an improvement method comprising the steps of altering the duration of heat and/or cool portions of the cycle counted by the standard control, sensing a first set of voltage and current characteristics flowing in the load during a heat impulse, generating a varying standard impedance characteristic from said first set of characteristics, sensing a second set of voltage and current characteristics, comparing impedance characteristics of the second set with the standard impedance characteristic, and generating an altering signal when the sensed impedance characteristic is not within the standard characteristics, and altering the heat and/or cool portions in response to the altering signal to maintain said second impedance characteristic within preselected limits of said standard characteristics.
Specification