SU846155A1 - Welding mode parameter recorder - Google Patents

Description

one

The invention relates to measuring devices for welded joints and can be used in mechanical engineering enterprises for monitoring welded joints of parts of structures by electric arc welding at constant and alternating currents.

A known recorder of parameters of welding modes is used to control and simultaneously register the following parameters: welding current, arc voltage, welding speed, shielding gas flow 1,

The known recorder does not provide a sufficiently objective and accurate assessment of the quality of the welded joint, since in the pulsed mode of welding it cannot monitor and record the pulse duration and pause of the welding current, which adversely affects the quality of the welded joint.

In practice, strict adherence to the established technological regime is required, especially when welding critical parts. A decrease in the current pulse duration can lead to a lack of penetration, and an increase in the burn-through of the material. The reduction of the welding current pause leads to

an increase in the pulse frequency of the current, which entails overheating and burn-through of the material. Increasing the pause respectively reduces the frequency of the pulses of the welding current leads to a weakening of the weld.

The purpose of the invention is to improve the accuracy and objectivity of the quality assessment of the welded joint during welding.

10 in pulsed mode.

The goal is achieved due to the fact that a unit for measuring the pulse current and the pause of the welding current is entered into the device,

15 is connected with its input to the switch and output to the matching unit.

When welding parts in a pulsed mode, the duration of the pulses and pauses of the welding current are set according to the requirements of the technological mode, depending on the material to the thickness of the parts to be welded. Welding step, i.e. pause ratio

25 and welding current pulses, is determined by the required strength characteristics of the product B in general, by the leaktightness of the weld, and t, l. Therefore, the quality of welded carbon dioxide (zeni depends on the accuracy of compliance with the established IHOTO technological mode, and the objectivity and accuracy of the assessment of the quality of the weld increases with monitoring and appropriate correction of the pulse duration and pause of the welding current.

Fig, 1 shows the block diagram of the recorder; in fig. 2 shows a circuit for measuring and recording a welding current pulse; Fig. 3 shows a circuit for measuring and recording a pause in a welding current; in fig. 4 shows timing charts for measuring pulse duration; Fig. 5 shows timing charts for measuring the pause duration.

The recorder is composed of switch 1, units 2-5 for measuring welding current, arc voltage, welding speed and flow of shielding gas, respectively, and block 6. Pulse and pause lengths connected via matching circuit 7 to a meter with 8 digital indicators and to the recorder 9. Unit 6 consists of two autonomous circuits: a circuit for measuring and recording a pulse of a welding current and a circuit for measuring and registering a pause for a welding current. Each of these circuits contains a forming trigger 10, a generator of 11 time intervals, an additional recorder 12 of the type H-3020/5, a multivibrator 13 waiting, a generator of 14 pulses, a counting element 15 and two keys 16 and 17. As the welding current pauses on The first input of the key 16 of the voltage drop is not present, then to simulate between the welding current source and the first input of the key 16, the trigger 18 is turned on.

Rabo a registrar is as follows.

When the welding machine power source is turned on, switch 1 sets the operation mode of measuring devices 2-6, respectively, due to welding (constant or alternating current), switching input matching and forming circuits. Signals from sensors built into the welding machine go through switch 1 to the corresponding measuring devices 2 -6 to form voltage levels of constant current proportional to the measured parameter. These levels, through matching device 7, enter the recorder 9 for registration and simultaneously to the counter 8 with digital indication, where their value is estimated for visual operational control.

When measuring the pulse duration and pause in the measuring device 6, the input signals are converted into positive pulses.

direct current, the duration of which is equal to the duration of the pulse and pause.

At the initial moment of time, the key 16 of the circuit for measuring and registering a welding current pulse is opened and the pulse through its first input enters the forming trigger 10 The trigger 10 is controlled by the front and rear edges of the welding pulse and thus generates a DC pulse equal in duration to the welding pulse. The generated pulse enters the additional recorder 12 for registration and, through the first input of the key 17, to the counting element 15 to determine its duration.

The trailing edge formed by the trigger 10 of the pulse starts the generator 11 time intervals. It generates a pulse duration of 1 second, by which the key 16 is locked at the second input. Therefore, the following welding current pulses do not pass through the key 16 to the registration and measurement circuits during the time specified by the generator 11 time intervals, i.e. for the time required to register and determine the duration of the welding pulse.

To prepare the counting element 15 for measurements, the standby multivibrator 13 serves. It is triggered by the leading edge of the pulse of the trigger 10 and gives a short pulse, resetting the counting element 15 to zero. The generator 14, operating in self-excitation mode, produces pulses of a frequency of 1 thousand Hz, which continuously enter the second input of the key 17, but pass through it to the counting element 15 only when the measured pulse generated by the trigger acts on the first input of the key 17 ten.

At the end of the second impulse of the generator 11 time intervals, the key 17 is opened and the next welding current impulse is fed to the formation, registration and measurement. The cycle is repeated.

The circuit for measuring the welding current pause is also performed with the difference that the trigger 18 is controlled by the falling edge of the previous and the leading edge of the next welding current pulse and thus gives a pulse equal to the duration of the welding current pause. From the outputs of the keys 17 formed in the circuit 6. pulses come through the matching 7 to the counter 8 and the recorder 9.

According to the readings of the digital indicator of the counter 8 and the recording on the diam. Frame paper of the self-feeding device 9 it is judged that the

set mode and quality of welding.

Introduction of a pulse duration meter and a pause current pulse to the recorder will allow determining the stability of these parameters during the welding process, which will increase the accuracy, reliability and objectivity of the quality assessment of the welded joint.

Claims (1)

1. Berdichevsky MG etc. The registrar of parameters of welding modes and its production 5 exploitation Ser. Progressive methods of metal processing, alloy I ldntp, Islands and other materials 1970. Impu / h with double welding current. CSapoiiHbtii current Ci & QHHlillJ