CN213957479U

CN213957479U - Cutting machine pilot arc detection circuitry

Info

Publication number: CN213957479U
Application number: CN202023070962.4U
Authority: CN
Inventors: 陈宇会; 余建国
Original assignee: Shanghai Mealer Welding Equipment Co ltd
Current assignee: Shanghai Mealer Welding Equipment Co ltd
Priority date: 2020-12-18
Filing date: 2020-12-18
Publication date: 2021-08-13
Anticipated expiration: 2030-12-18

Abstract

The utility model relates to a cutting machine pilot arc detection circuitry technical field specifically discloses a cutting machine pilot arc detection circuitry, including drive circuit, signal detection circuitry, filter circuit and transformer T1, be connected through transformer T1 between drive circuit and the signal detection circuitry, filter circuit interconnect; the driving circuit is connected with a driving signal input end and a power supply VCC, the filter circuit is connected with a detection signal output end, and the transformer T1 is connected with a first input end of cutting main arc current and a second input end of cutting main arc current; the utility model discloses utilize the magnetic ring to flow through the electromagnetic field that produces at having the electric current, magnetic ring saturation principle detects cutting main arc output current when magnetic induction intensity is strong enough, keeps apart to detect anti-interference strong, and the voltage value that utilizes the magnetic ring to wind on the magnetic ring after full changes the value and judges whether there is cutting main arc output current for the coil inductance on the magnetic ring after zero.

Description

Cutting machine pilot arc detection circuitry

Technical Field

The utility model relates to a cutting machine pilot arc detection circuitry technical field specifically is a cutting machine pilot arc detection circuitry.

Background

In most plasma cutting machines with pilot arcs in the market, three main ways are mainly adopted when the pilot arcs are cut and main arcs are converted for cutting, wherein a Hall circuit detects whether a main arc loop has cutting output current, a reed switch detects whether the main arc loop has cutting output current, and a shunt circuit detects whether the main arc loop has cutting output current.

The Hall detects whether the main arc loop has cutting output current, the isolation detection has strong anti-interference, but the device cost is high, and the detected main arc current signal processing circuit is complex;

the reed switch detects whether the main arc loop has cutting output current or not, isolation detection is strong in anti-interference, but devices are complex to install and easy to damage, and the devices are easy to shake and damage in the transportation process;

whether a main arc loop of the current divider has cutting output current or not, the detection signal is not isolated and weak in anti-interference, and a detected main arc current signal processing circuit is complex.

Three kinds of modes all have the defect, for solving above-mentioned problem, the utility model discloses utilize the magnetic ring to flow through the electromagnetic field that produces at the electric current, utilize the magnetic ring saturation principle to detect cutting main arc output current when magnetic induction intensity is strong enough.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a cutting machine pilot arc detection circuitry to solve the problem that proposes among the above-mentioned background art.

In order to achieve the above object, the utility model provides a following technical scheme: a pilot arc detection circuit of a cutting machine comprises a driving circuit, a signal detection circuit, a filter circuit and a transformer T1, wherein the driving circuit is connected with the signal detection circuit through a transformer T1, and the signal detection circuit and the filter circuit are connected with each other; the driving circuit is connected with a driving signal input end and a power VCC, the filter circuit is connected with a detection signal output end, and the transformer T1 is connected with a first cutting main arc current input end and a second cutting main arc current input end.

Preferably, the driving circuit comprises a resistor R1, a resistor R2, a resistor R3, a transistor Q1, a transistor Q2 and a transistor Q3, wherein one section of the resistor R1 is connected with the driving signal input end, and the other end of the resistor R1 is connected with pin 2 of the transistor Q1; a pin 1 of the triode Q1, a resistor R3, a pin 2 of the triode Q2 and a pin 2 of the triode Q3 are connected, the resistor R2 and the resistor R3 are connected with a power supply VCC, and the resistor R2 is connected with a pin 1 of the triode Q2; pin 3 of the transistor Q2 and pin 3 of the transistor Q3 are connected to pin 1 of the transformer T1, and pin 3 of the transistor Q1 and pin 1 of the transistor Q3 are grounded.

Preferably, the signal detection circuit comprises a resistor R4, a resistor R6 and a capacitor C1, the resistor R4 is connected with the 4-pin of the transformer T1, the resistor R4, the resistor R6 and the capacitor C1 are connected with each other, and the resistor R6 and the capacitor C1 are grounded.

Preferably, the filter circuit comprises a diode D1, a capacitor C2 and a resistor R5, wherein the anode of the diode D1 is connected with the signal detection circuit, and the cathode of the diode D1, the resistor R5 and the capacitor C2 are connected and then connected with the detection signal output end; the capacitor C2 and the resistor R5 are grounded.

Preferably, pin 8 of the transformer T1 is connected to the first input end of the main arc cutting current, and pin 5 of the transformer T1 is connected to the second input end of the main arc cutting current.

Compared with the prior art, the beneficial effects of the utility model are that: the utility model discloses utilize the magnetic ring to flow through the electromagnetic field that produces at having the electric current, magnetic ring saturation principle detects cutting main arc output current when magnetic induction intensity is strong enough, keeps apart to detect anti-interference strong, and the voltage value that utilizes the magnetic ring to wind on the magnetic ring after full changes the value and judges whether there is cutting main arc output current for the coil inductance on the magnetic ring after zero.

Drawings

Fig. 1 is a schematic structural view of the present invention;

fig. 2 is a graph of voltage waveforms on the capacitors C1 and C2 when no main cutting arc current passes;

fig. 3 is a graph of voltage waveforms on the capacitors C1 and C2 when the main cutting arc current of the present invention passes through;

reference numbers in the figures: 1. a drive circuit; 2. a signal detection circuit; 3. a filter circuit; 4. a drive signal input; 5. a detection signal output end; 6. a first input end for cutting main arc current; 7. a second input end for cutting main arc current; a is the waveform of the capacitance C2; b is the waveform of the capacitor C1.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

Referring to fig. 1-3, the present invention provides a technical solution: a cutting machine pilot arc detection circuit comprises a driving circuit 1, a signal detection circuit 2, a filter circuit 3 and a transformer T1, wherein the driving circuit 1 is connected with the signal detection circuit 2 through a transformer T1, and the signal detection circuit 2 and the filter circuit 3 are connected with each other; the driving circuit 1 is connected with a driving signal input end 4 and a power supply VCC, the filter circuit 3 is connected with a detection signal output end 5, and the transformer T1 is connected with a first cutting main arc current input end 6 and a second cutting main arc current input end 7.

Further, the driving circuit 1 includes a resistor R1, a resistor R2, a resistor R3, a transistor Q1, a transistor Q2, and a transistor Q3, one section of the resistor R1 is connected to the driving signal input terminal 4, and the other end of the resistor R1 is connected to pin 2 of the transistor Q1; a pin 1 of the triode Q1, a resistor R3, a pin 2 of the triode Q2 and a pin 2 of the triode Q3 are connected, the resistor R2 and the resistor R3 are connected with a power supply VCC, and the resistor R2 is connected with a pin 1 of the triode Q2; pin 3 of the transistor Q2 and pin 3 of the transistor Q3 are connected to pin 1 of the transformer T1, and pin 3 of the transistor Q1 and pin 1 of the transistor Q3 are grounded.

Further, the signal detection circuit 2 includes a resistor R4, a resistor R6, and a capacitor C1, the resistor R4 is connected to the 4-pin of the transformer T1, the resistor R4, the resistor R6, and the capacitor C1 are connected to each other, and the resistor R6 and the capacitor C1 are grounded.

Further, the filter circuit 3 includes a diode D1, a capacitor C2, and a resistor R5, wherein the anode of the diode D1 is connected to the signal detection circuit 2, and the cathode of the diode D1, the resistor R5, and the capacitor C2 are connected to the detection signal output terminal 5; the capacitor C2 and the resistor R5 are grounded.

Furthermore, pin 8 of the transformer T1 is connected to the first input terminal 6 of the main arc cutting current, and pin 5 of the transformer T1 is connected to the second input terminal 7 of the main arc cutting current.

The working principle is as follows: a resistor R1, a triode Q1, a resistor R3, a resistor R2, a triode Q2 and a triode Q3 form a driving circuit 1 of a transformer T1, a resistor R4, a resistor R6 and a capacitor C1 form a signal detection circuit 2, and voltage signals generated by cutting main arc current flowing through the transformer T1 to the ground at the resistor R6 are detected; the diode D1, the capacitor C2 and the resistor R5 form a filter circuit 3, convert the pulse signal generated by the resistor R6 into a direct-current voltage signal with a small literal wave, and supply the direct-current voltage signal to other control circuits through a detection signal output end 5.

The resistor R2, the triode Q2, the transformer T1, the resistor R4 and the resistor R6 form a loop when the triode Q2 is switched on, and the capacitor C1 is charged; the capacitor C1 is rectified by the diode D1 to charge the capacitor C2, the resistor R6 discharges the capacitor C1 when the triode Q2 is cut off, and the resistor R5 discharges the capacitor C2 to ensure that the voltage value of the capacitor C2 is changed according to the change of the inductive reactance (XL) of the transformer T1.

A square wave driving signal is input into a driving signal input end 4, and the on and off of a triode Q2 and a triode Q3 are controlled through a resistor R1 and a resistor R3; when the driving signal input end 4 inputs a low level, the triode Q2 is conducted, the triode Q3 is cut off, at the moment, a power supply VCC forms a loop to GND through the resistor R2, the triode Q2, the transformer T1, the resistor R4 and the resistor R6, and the primary current of the transformer T1 cannot generate inductive reactance (XL) suddenly and store energy; when the drive signal input end 4 inputs high level, the triode Q3 is conducted, the triode Q2 is cut off, and the transformer T1 directly faces GND to instantly release the energy stored when being conducted, so that the cycle work is realized.

When the primary arc cutting current first input end 6 and the primary arc cutting current second input end 7 of the transformer T1 have no primary arc cutting current: when a low level is input to the driving signal input terminal 4, the transistor Q2 is turned on, the transistor Q3 is turned off, the power source VCC forms a loop to GND through the resistor R2, the transistor Q2, the transformer T1, the resistor R4 and the resistor R6, at this time, the power source VCC charges the capacitor C1 through the resistors R2, XL and the resistor R4, the charging voltage amplitude of the capacitor C1 does not exceed the voltage amplitude of the resistors R2, XL, the resistor R4 and the resistor R6 when forming the loop to GND, the voltage value at two ends of the resistor R6 is calculated through ohm's law, the voltage of the capacitor C1 is rectified through the diode D1 to charge the capacitor C2, the resistor R5 discharges the capacitor C2, the resistor R6 discharges the capacitor C1 when the transistor Q2 is turned off, and the voltage waveforms of the capacitor C1 and the capacitor C2 are as shown in fig. 2.

When the main cutting arc current flows through the first input end 6 of the secondary main cutting arc current of the transformer T1 and the second input end 7 of the main cutting arc current, the primary saturation inductive reactance (XL) of the transformer T1 is zero, a low level is input to the driving signal input terminal 4, the triode Q2 is turned on, the triode Q3 is turned off, the power supply VCC forms a loop to GND through the resistor R2, the triode Q2, the transformer T1, the resistor R4 and the resistor R6, at this time, the power supply VCC charges the capacitor C1 through the resistors R2, XL and the resistor R4, the voltage value at two ends of the resistor R6 is calculated through ohm's law when the charging voltage amplitude of the capacitor C1 does not exceed the voltage amplitude of the resistors R2, XL, the resistor R4 and the resistor R6 form a loop to GND, the voltage of the capacitor C1 is rectified through the diode D1 to charge the capacitor C2, the resistor R5 discharges the capacitor C2, the resistor R6 discharges the capacitor C1 when the triode Q2 is turned off, and at this time, the voltage waveforms on the capacitor C1 and the capacitor C2 are as shown in fig. 3.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims

1. A cutting machine pilot arc detection circuit is characterized in that: the circuit comprises a driving circuit (1), a signal detection circuit (2), a filter circuit (3) and a transformer T1, wherein the driving circuit (1) is connected with the signal detection circuit (2) through a transformer T1, and the signal detection circuit (2) and the filter circuit (3) are connected with each other; drive circuit (1) is connected with drive signal input part (4), power VCC, filter circuit (3) are connected with detect signal output part (5), transformer T1 is connected with cutting main arc electric current first input end (6), cutting main arc electric current second input end (7).

2. The cutter pilot arc detection circuit according to claim 1, wherein: the driving circuit (1) comprises a resistor R1, a resistor R2, a resistor R3, a triode Q1, a triode Q2 and a triode Q3, wherein one section of the resistor R1 is connected with the driving signal input end (4), and the other end of the resistor R1 is connected with a pin 2 of the triode Q1; a pin 1 of the triode Q1, a resistor R3, a pin 2 of the triode Q2 and a pin 2 of the triode Q3 are connected, the resistor R2 and the resistor R3 are connected with a power supply VCC, and the resistor R2 is connected with a pin 1 of the triode Q2; pin 3 of the transistor Q2 and pin 3 of the transistor Q3 are connected to pin 1 of the transformer T1, and pin 3 of the transistor Q1 and pin 1 of the transistor Q3 are grounded.

3. The cutter pilot arc detection circuit according to claim 1, wherein: the signal detection circuit (2) comprises a resistor R4, a resistor R6 and a capacitor C1, wherein the resistor R4 is connected with a pin 4 of a transformer T1, the resistor R4, the resistor R6 and the capacitor C1 are connected with one another, and the resistor R6 and the capacitor C1 are grounded.

4. The cutter pilot arc detection circuit according to claim 1, wherein: the filter circuit (3) comprises a diode D1, a capacitor C2 and a resistor R5, wherein the anode of the diode D1 is connected with the signal detection circuit (2), and the cathode of the diode D1, the resistor R5 and the capacitor C2 are connected and then connected with the detection signal output end (5); the capacitor C2 and the resistor R5 are grounded.

5. The cutter pilot arc detection circuit according to claim 1, wherein: and the pin 8 of the transformer T1 is connected with a first input end (6) of the cutting main arc current, and the pin 5 of the transformer T1 is connected with a second input end (7) of the cutting main arc current.