ITVI20100185A1 - ACOUSTIC SIGNALING SYSTEM EMPLOYABLE IN WELDING PROCESSES AND RELATIVE METHOD - Google Patents

Description

ACOUSTIC SIGNALING SYSTEM THAT CAN BE USED IN

WELDING PROCESSES AND RELATIVE METHOD

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The present invention generally refers to an acoustic signaling system that can be used in welding processes and to a related method.

More specifically, the invention relates to an acoustic signaling system, which can be integrated into a welding generator, which, by means of suitable modulations of the welding arc, is able to emit defined and audible sounds from the Operator, so that the operator himself is able to interpret the changes in the welding parameters he has set.

In modern electric arc welding, be it MIG / MAG or TIG type, complex operating cycles are increasingly required, with alternating, continuous, pulsed, ramp, double pulsation currents, etc. On the basis of this and in order to avoid relying solely on the competence and experience of the operators, we usually tend to leave most of the generator settings to a control logic (relating, for example, to the regulation of the gas flow in welding or air in plasma cutting), leaving the operator to set only a few parameters, such as, for example, the welding current and / or the thickness of the material to be welded or cut.

In this regard, welding torches still exist on the market that incorporate some keys available to the operator, who can thus change the welding parameters and, in particular, increase or decrease the welding current and / or set predefined working modes, without interrupting the work.

However, the operator who welds normally wears a helmet with a darkening visor, which serves to protect the operator's eyes, but inevitably limits their visibility.

Furthermore, during the welding operation, the operator is concentrated on the work and does not have the possibility to see any displays or display panels on the machine that provide him with feedback on the changes or adjustments made.

It follows that, despite having the aforementioned adjustment buttons available on his torch, the operator is still unable to make the best use of this possibility, as he is unable to obtain an immediate confirmation of the adjustment or of the selected processing mode.

In the context of the above-mentioned requirements, the aim of the present invention is therefore to obviate the aforementioned drawbacks.

In particular, the primary purpose of the invention is to indicate an acoustic signaling system that can be used in welding processes, capable of emitting sounds defined and interpretable by the operator, in order to help him, during the welding phase, to monitor particular situations and, ultimately, to simplify the work performed.

Another purpose of the present invention is to provide an acoustic signaling system that can be used in welding processes, which allow the operator to interpret and evaluate the modalities and / or the variations set.

Another purpose of the present invention is to implement an acoustic signaling method that can be used in welding processes by means of the above system. A further aim of the invention is to make available an acoustic signaling system that can be used in welding processes, which is extremely reliable, efficient and functional.

The above objects are achieved by means of an acoustic signaling system, usable in welding processes, according to the attached claim 1, and by means of a relative method, according to the attached claim 4.

Further detailed technical and applicative characteristics of the acoustic signaling system and method respectively, object of the present invention, are described in the corresponding dependent claims.

Advantageously, the sound signals, designed to confirm to the operator that the required variations have been activated (through longer or shorter sound pulses), are produced, according to the invention, by means of appropriate modulations of the welding arc. , however, such as not to compromise the quality of the welding itself.

In this way, the generation of sounds occurs without the addition of electrical and / or electronic components and, therefore, without any increase in costs and, moreover, since the sound is emitted directly from the welding arc, this sound is also It is generated exactly in the vicinity of the operator who will therefore be able to hear it easily. In addition, the sound produced has an intensity proportional to the background noise generated by the welding arc, without generating unnecessarily loud noises for the operatorâ € ™ s ear.

According to the invention, for example, a simple sound impulse can provide the operator with confirmation that the set variation has been activated, while a longer sound impulse can inform, instead, that the setting cannot be activated. (for example, as a setting full scale has been reached).

Finally, any sound messages can also be used for other purposes, such as, for example, alarm signals and / or the like.

Further characteristics and advantages of the system and of the sound signaling method that can be used in welding processes will become more evident from the following description, relating to a preferred embodiment and application of the present invention, given by way of example and by way of non-limiting example, with the Aid of the annexed drawings in which: - figure 1 shows a generic block diagram of a welding apparatus which incorporates a sound signaling system, according to the present invention;

- figure 2 shows a Cartesian graph relating to the trend, over time, of the arc current generated during the welding process (the wave form depends on the selected welding process);

- figure 3 shows a Cartesian graph relating to the trend, over time, of the arc current modulated by the acoustic signaling system according to the present invention.

In relation to the attached figure 1, the numerical reference 10 indicates an arc current generator of a generic welding apparatus, usable for all types of welding, to whose input a single-phase or three-phase power cable 11 is connected and to whose output are connected, respectively, a ground cable 12 and a connection cable 13 to the welding torch.

The arc current generator 10 is essentially composed of an input power supply circuit 14, a control circuit 15 and a power circuit 16, which can be of the chopper or inverter type.

The power circuit 16 is suitable for converting a direct current into an alternating current, possibly at a different voltage, or an alternating current into another having a different frequency.

In the realization of the inverter power circuit 16, switching type power components are normally used, such as IGBTs, thyristors or MOSFETs, as switches, which, driven by an oscillator, produce the desired wave form at the output.

By opening and closing a circuit, in fact, a square wave is generated, which is applied to a transformer to supply the required voltage at the output (rounding the square wave in some way). In any case, the best inverters base their operation on pulse width modulation (PWM) and the system can be retro-operated to provide a stable output voltage as the input voltage varies.

Normally, an attempt is made to establish a working frequency that is a good compromise between response speed and low dissipation and, once the frequency has been set, the inverter control circuit 15 modulates the duty-cycle of the output signal from the component switching to obtain the desired output waveform.

In practice, to control the output arc current, either a frequency modulation (usually with a fixed duty-cycle of a predetermined value established in microseconds) or a duty-cycle modulation (with fixed frequency) is usually used , or a mixed system of the two previous ones, by activating the control circuit 15, in order to obtain the desired output waveform.

In practice, the voltage or single-phase or three-phase alternating current signal present at the input of the generator 10 is rectified, smoothed and converted into a respective voltage or direct current signal and, therefore, alternated again and modulated in frequency ( with fixed duty-cycle) and / or in pulse width (modulation of duty-cycle with fixed frequency, for example equal to about 100 kHz).

As already said, the power circuit 16 is connected with the electronic control circuit 15, driven by a microprocessor logic, which is in turn based on a management software program, which determines the voltage or current pulses. , the shape of these pulses and the desired modulation (in frequency or duty-cycle).

The voltage or alternating current signal is then sent to a transformer and to a rectifier device, so as to result again a voltage or direct current signal at the output cable 13 for connection to the welding torch.

As already noted, the control circuit 15 is responsible for the generation, through the power circuit 16, of an arc current I, which, depending on the welding process used, has a specific wave form A , having a predetermined course in time t, as indicated, purely by way of example, but not limiting, in the Cartesian diagram of the attached figure 2.

In order to generate the acoustic signals necessary, according to the present invention, to provide the desired information to the operator regarding the variations in the welding parameters set by him, usually at the software level, the control circuit 15 is used. , so that it is able to modify, in turn, the trend, in time t, of the waveform A of the arc current I. In particular, it is possible to insert pulses or packets of high frequency P pulses in the wave form A, so as to modify it in time t (as indicated in the schematic diagram of the attached figure 3, where three single P pulses are indicated).

Specifically, moreover, the P impulses must have a fixed distance between two successive P impulses (as this distance determines the tone of the sound) and a predetermined amplitude (since, through the amplitude, the intensity is determined of the sound, which must be audible â € œuperiorlyâ € to the continuous, unmodulated sound or noise generated by the welding arc current).

Furthermore, the number of pulses P, which determines the duration of the sound, must be prefixed and each pulse P must be symmetrical, that is to say that an increase in the current must correspond to an equivalent decrease, so that the current value dâ € ™ arc The media delivered does not change with respect to the original A waveform.

In practice, by perturbing and, in particular, by modulating the trend of the welding arc current I, it is thus possible to obtain the emission of a sound from the generator 10 which offers certain information to the operator during the welding process (for example, the sound of 1 beep can be associated with a specific type of processing selected by the operator using the relative button on the welding torch, the sound of 2 beeps can be associated with another type of work selectable by the operator, etc., as well as it is also possible to use the acoustic signal as an alarm signal, such as the lack of gas to the welding torch).

As mentioned, the sound generation is achieved by perturbing the wave form of the welding arc current and this perturbation is obtained, in particular, by the software present in the microprocessor that manages the control circuit 15, so such as to obtain at the output a predetermined signal to be sent to the analog control.

From the description just made, the characteristics of the acoustic signaling system and method that can be used in the welding processes, both of which are the object of the present invention, are therefore clear, as are the advantages.

Finally, it is clear that numerous other variations can be made to the acoustic signaling system and method in question, without departing from the novelty principles inherent in the inventive idea, just as it is clear that, in practice implementation of the invention, the materials, shapes and dimensions of the illustrated details may be any according to requirements and the same may be replaced with other technically equivalent ones.

Where the construction features and techniques mentioned in the subsequent claims are followed by reference marks or numbers, these reference marks have been introduced with the sole aim of increasing the intelligibility of the claims themselves and, consequently, they have no effect. limiting on the interpretation of each element identified, purely by way of example, by these reference signs.

Claims (6)

CLAIMS 1. Acoustic signaling system usable in welding processes, comprising a voltage or arc current generator (10), at the input of which there is a power supply cable (11) and at the output of which at least one power cable is provided. ground (12) and at least one connection cable (13) to at least one welding torch, said torch being equipped with at least one button for the setting and / or adjustment by an operator of at least one operating parameter of said generator (10), said generator (10) also including at least one power supply circuit (14) and at least one power circuit (16), connected to at least one control circuit (15) and able to generate a voltage signal or current (I) at the output having a specific wave form (A), whose trend over time (t) is a function of the welding process set, characterized by the fact that said control circuit (15) comprises a microprocessor programmed in a way add said waveform (A) of the voltage or current signal (I) over time (t) with the addition of pulses or packages of pulses (P), at high frequency, of predetermined quantity and amplitude , each of said pulses or packages of pulses (P) presenting a symmetry with respect to the trend of said waveform (A), so that the average voltage or current (I) delivered in a given range of time (t) does not change with respect to the original wave form (A). 2. System as per claim 1) characterized in that said power circuit (16) is chopper or inverter. 3. System as in claim 1) characterized in that a predetermined distance is provided between two successive pulses or packets of pulses (P). 4. Acoustic signaling method that can be used in welding processes characterized by the fact of providing at least one modulation phase of a voltage or current signal (I) at the output of a welding generator (10), modifying its wave form (A) in time (t), through the insertion of high frequency pulses or packets of pulses (P), of predetermined quantity and amplitude, in which each of said pulses or packets of pulses (P) presents a symmetry with respect to Trend of said waveform (A), so that the average voltage or current (I) value delivered in a given time interval (t) does not change compared to the original waveform (A) . 5. Method as in claim 4) characterized by the fact that said pulses or packages of pulses (P) produce one or more sounds, which are emitted by said generator (10), having an intensity proportional to the background noise generated by the welding process . 6. Method as in claim 5) characterized by the fact that said sounds provide the operator with certain information on types of processing and / or operating parameters of the welding process and / or confirmations relating to the activation or not of variations set or selected by the operator of certain parameters, said sounds being also usable for alarm signals and / or the like, such as the lack of gas to the welding torch.