Control and monitor for rotating arc welder

• US 3,980,857 A
• Filed: 10/29/1974
• Issued: 09/14/1976
• Est. Priority Date: 10/29/1974
• Status: Expired due to Term

• Current Assignee: Sciaky Bros Incorporated
• Original Assignee: Welding Research Incorporated
• Inventors: Sciaky, David
• Primary Examiner(s): Grimley, Arthur T.
• Assistant Examiner(s): Shaw, Clifford C.
• Application Number:
  US05/518,796
• Time in Patent Office: 686 Days
• Field of Search: 219/97, 219/100, 219/101, 219/104, 219/108, 219/109, 219/110
• US Class Current: 219/100
• CPC Class Codes: B23K 9/08 Arrangements or circuits for magnetic control of the arc stabilising of the arc position by magnetic means B23K9/0737
• CPC Class Codes: B23K 9/22 Percussion welding

Abstract

A method and apparatus for monitoring parameters which control the quality of welds made by the rotating arc method. Total electrical energy delivered to the parts being welded is controlled and its analog divided by the time during which this energy was applied to obtain average rate of energy delivered. Total mechanical work done on parts being welded and the mechanical relative displacement of machine platens is measured and work analog is divided electronically by the displacement analog to determine average mechanical work per unit of displacement. The two averages thus obtained are compared to preset levels of average electrical energy and mechanical work which have been established empirically. Indicators warn the operator of any variation from the norm. Separate indications and comparisons are also made of each of the parameters.

Claims

1. A method of monitoring the parameters which affect the quality of welds produced in parts being welded by the rotating arc process comprising the steps, after initiation of the arc voltage and current, of;

generating a voltage which represents the time average of electrical energy delivered to parts being welded;

generating a voltage which represents the average mechanical work per unit of displacement of the platens supporting the parts, which is performed on the parts during the forging operation as they move with respect to one another;

causing the said voltages to be compared respectively with ranges of preset voltages which represent respectively values of electrical energy per unit time and values of mechanical work per unit distance which, when delivered to the said parts, result in acceptable welds,

developing from said comparison an aural or visual signal when either of said voltages are outside the preset range of voltages to which they are compared.

2. A method, as in claim 1, including the steps of measuring the total electrical energy delivered to the parts being welded and interrupting the flow of said energy when said energy reaches a preset level.

3. A method of monitoring the quality of welds produced by the rotating arc process comprising the steps, after initiation of the arc voltage and current, of;

generating a voltage which represents the voltage fed to the said arc;

generating a second voltage which represents the electric current passing through the said arc;

multiplying by electronic means the voltages which represent the arc voltage and current to obtain a voltage which represents the instantaneous electrical power delivered to the work;

feeding the last mentioned voltage to an electronic integrator so as to obtain a voltage which is the analog of the total electrical energy delivered to the arc;

generating an analog voltage which is proportional to the length of time the said arc current is flowing;

causing the said integrated electrical energy analog voltage to be divided by the said time analog voltage in an electronic divider;

feeding the output of the said divider to a window comparator so as to compare said signal output with a pre-established range of signals;

generating a signal as a result of said comparison which indicates whether the signal resulting from the said division is below, within the range of, or above pre-established limits for average electrical energy per unit of time;

generating a voltage which represents the upsetting force between the parts being welded;

generating a voltage which represents the relative displacement between the platens of the welding machine during the upset period;

multiplying by electronic means the last mentioned voltages so as to obtain a product voltage which represents the instantaneous mechanical work done on the parts being welded;

integrating by electrical means the last mentioned product voltage so as to obtain an analog voltage representing the total mechanical work performed on the parts being welded;

dividing by electrical means the last mentioned analog voltage by the voltage representing the total motion of the platens with respect to each other to obtain a voltage representing average work per unit displacement of the said platens during said motion;

comparing the voltage resulting from the last said division with a pre-established range of voltages;

generating a signal as a result of said comparison which indicates whether the said average work is below, within, or above the range of pre-established limits;

feeding the signals resulting from the aforesaid energy comparison and work comparison to a means which will develop a warning indication if either one of the last mentioned signals are not within their pre-established limits.

4. A method in accordance with claim 3 including the additional step of causing interruption of the flow of welding current when the total electrical energy input to the parts being welded reaches a preset level.

5. Apparatus for monitoring the quality of welds produced by the rotating arc welding process in parts which are upset and forged by the relative motion between a moving and stationary platen which support the parts on the welding machine, comprising;

means for delivering a pre-determined electrical energy to the parts being welded;

means for determining the total time for application of the said energy;

means depending upon the aforesaid two means for generating a voltage which represents the average electrical energy delivered to the work over the said time;

means for comparing the said voltage with a preset voltage range;

means cooperating with said comparison means for indicating whether said voltage is below, within or above the said preset voltage range;

additional means for generating a voltage which represents the upsetting force applied to the parts being welded;

means for generating a voltage which represents the relative displacement between the platens of the welding machine during the upset period;

means depending upon said last two mentioned means for generating a voltage that represents the average mechanical work per unit displacement applied to the parts during the said motion;

means for comparing the last mentioned voltage which represents average mechanical work with a preset reference voltage range;

means associated with the last said comparison means for indicating whether the last mentioned voltage is below, within or above the said second preset voltage range; and

means for providing a warning signal if either of said voltages representing average energy per unit time and work per unit of displacement of said platens is not within its associated preset voltage range.

6. Apparatus as in claim 5 which includes additional means for indicating whether the relative motion between the machine platens is within preset limits.

7. Apparatus as in claim 6 which includes means for indicating whether the total weld time is within preset limits.

8. Apparatus as in claim 6 which includes means for indicating whether the mechanical work is within preset limits.