CN2135423Y

CN2135423Y - Air plasma cutting machine

Info

Publication number: CN2135423Y
Application number: CN 92241036
Authority: CN
Inventors: 赵京
Original assignee: Dongsheng Qinghe Electromechanical Equipment Factory Haidian Dist Beijing (cn
Current assignee: Dongsheng Qinghe Electromechanical Equipment Factory Haidian Dist Beijing (cn
Priority date: 1992-11-17
Filing date: 1992-11-17
Publication date: 1993-06-09
Anticipated expiration: 2002-11-17

Abstract

The utility model provides an air plasma cutting machine, which is assembled by functional modules, such as a front panel, a main circuit, a main transformer, and a controlling circuit. A photocoupler is arranged between a high-voltage and a low-voltage circuits to isolate high and low voltages and transmit signals; a protective circuit for short circuit, a protective circuit for cutting torch, an operating-condition circuit, and a trouble-display circuit are positioned in the circuit. The utility model has the advantages of small size, light weight, and convenient production, use, and maintenance.

Description

Air plasma cutting machine

The utility model belongs to a kind of arc cutting machine, is that the plasma arc with high temperature and high speed is the arc cutting machine of thermal source specifically.

As homemade LGK cutting machine, there is following weak point in existing air plasma cutter:

1. circuit design is aging, and by the isolation of transformer realization hi-lo circuit, machine volume weighs greatly.

2. do not have short-circuit protection function, in a single day major loop breaks down, and can only cut off the electricity supply by user's distribution system.

3. whether circuit working does not normally have corresponding demonstration, requires to have maintenance technique preferably.

4. structural design is unreasonable, is unfavorable for product seriation, also is not easy to assembling, maintenance.

In view of the problems referred to above of existing air plasma cutter, the utility model proposes a kind of improved cutting machine.

The purpose of this utility model provides a kind of air plasma cutter, utilizes photoelectrical coupler to realize the isolation and the signal transmission of hi-lo circuit, weight reduction, reduced volume.

Another purpose of the present utility model provides a kind of air plasma cutter with short-circuit protection circuit.

Another purpose of the present utility model provides a kind of air plasma cutter that also has the cutting torch short-circuit protection circuit.

But a purpose more of the present utility model provides a kind of kinds of displays with display circuit duty, so that equipment is carried out the air plasma cutter of self diagnosis.

Next purpose of the utility model provides a kind of air plasma cutter of module combinations structure, so that produce in batches, improve and maintenance.

Below by specific embodiment the utility model air plasma cutter is elaborated, referring to following accompanying drawing:

Fig. 1 is the utility model cutting machine left side view.

Fig. 2 is the utility model cutting machine right side view.

Fig. 3 is the utility model cutting machine circuit function schematic diagram.

Fig. 4-1,4-2,4-3 are the circuit theory diagrams of Fig. 3 each several part.

Basic structure of the present utility model is identical with general cutting machine, is made up of casing and inner major loop, striking unit and control module thereof; Major loop comprises three-phase power line, main transformer B1, rectification and electrode output circuit; The striking unit comprises high-frequency high-voltage circuit with step-up transformer B3 and the transformer B4 that is coupled with major loop output; Control module comprises cutting torch K switch, striking, electromagnetic valve of gas circuit and various display control circuit; Of the present utility model being characterised in that:

Be equiped with photoelectrical coupler between high-tension circuit in the foregoing circuit and the low-voltage circuit, high-low pressure is isolated and the signal transmission to carry out, and this photoelectrical coupler is encapsulated by the receiving terminal 2 of the transmitting terminal 1 of electric light conversion and an opto-electronic conversion and constitutes, and its interlock circuit is:

380 volts of AC powers are through transformer B2 step-down, supply with control module through rectification output low pressure (as 15 volts) DC voltage again, the transmitting terminal 1 of described photoelectrical coupler is connected to the emitter stage of the transistor T 1 of low-voltage direct control circuit, and its receiving terminal 2 is connected to the elementary of transformer B2; The branch road that this primary wire also in parallel is in series by a main circuit power contactor coil CJ1 and a two-way controllable silicon 3, the trigger end of this controllable silicon 3 links to each other with the receiving terminal of described photoelectrical coupler 2; During cutting machine work, transistor T 1 conducting of control circuit, photoelectrical coupler work, controllable silicon 3 conductings, CJ1 coil operate as normal, its contact CJ1 closure, main circuit power conducting.

Because the utility model cutting machine has adopted above-mentioned photoelectrical coupler to realize that high-low pressure is isolated and the signal transmission, thereby has replaced the big capacity isolating transformer in the conventional cutter, transformer B2 can replace the transformer of 250W with the 20W miniature transformer;

The utility model cutting machine has short-circuit protection circuit, it consists of: two current transformer B5, B6 are installed in respectively on two phase lines of main circuit power, the input of the bistable voltage comparator A1 of its output in rectification and OR circuit 4 and control circuit links to each other, and another input of comparator A1 is a reference voltage; The transmitting terminal 1 of the output control aforementioned lights electric coupler of comparator A1, such as, can be by the conducting of the aforementioned transistor T 1 of control and by controlling the luminous of photoelectrical coupler transmitting terminal 1 with not luminous; When source current is excessive; transformer B5 or B6 output signal to comparator A1; make comparator A1 be output as high potential; through transistor circuit described transistor T 1 is ended; photoelectrical coupler transmitting terminal 1 is not luminous; its receiving terminal 2 ends; thereby Triggerless is delivered to the trigger electrode of described bidirectional triode thyristor 3; controllable silicon 3 not conductings; the CJ1 coil is not worked; its contact CJ1 disconnects; thereby main circuit power disconnects; realized the short-circuit protection effect; for power supply is reliablely and stablely disconnected, comparator A1 is connected to a positive feedback resistor R1, can make the stable short-circuit protection control signal of its output.

The utility model cutting machine also can be installed the cutting torch short-circuit protection circuit, promptly between the ground terminal of electrode shield 5 and major loop output, be connected to a cutting torch short-circuit protection relay coil CJ4, with CJ4 coils from parallel connection of coils one low-resistance high-power resistance R2, such as 8 ohm of 400 watts of resistance; The normally-closed contact of serial connection one CJ4 on controllable silicon 3 branch roads of aforementioned transformer B2 primary wire; When being short-circuited between guard shield 5 and the electrode 6, big current flowing resistance R2 boosts the R2 two ends; thereby coil CJ4 work, its normally closed contact CJ4 disconnects, thus not conducting of coil CJ1; its contact CJ1 disconnects, so main circuit power is cut off, has realized the cutting torch short-circuit protection.

The utility model also has the display unit of display working condition and fault origination point, comprising:

1. the compressed air ventilation shows: compressed air electromagnetic valve coil 7 is connected with transistor T 2, be connected in the low-voltage dc circuit of control module, and this coil 7 ventilation indicator lamp L1 in parallel, coil 7 conductings, when promptly magnetic valve was opened, indicator lamp L1 was bright, showed that ventilation is normal.

2. cutting work shows: cutting relay indicating light L2 is serially connected on the series arm of aforementioned lights electric coupler transmitting terminal 1 and transistor T 1, when cutting work is carried out, and transistor T 1 conducting, indicator lamp L2 is bright.

3. striking work shows: the utility model is identical with general cutting machine, arc ignition circuit also has a step-up transformer B3 and high voltagehigh frequency voltage is coupled to the transformer B4 of telegraph circuit, it is characterized in that having an arc ignition control circuit, this control circuit comprises a voltage comparator A3, the input of comparator A3 is a reference voltage, another input is controlled by the cutting torch K switch, a transistor T 4 is controlled in the output of comparator A3, this transistor T 4 is connected with striking relay coil CJ2, is connected in the control circuit; In the elementary of arc ignition circuit transformer B3 and major loop guard shield circuit, be connected to the CJ2 normally opened contact respectively; A striking indicator lamp L3 in parallel on described CJ2 coil; When the cutting torch K switch was closed, comparator A3 was output as high potential, transistor T 4 conductings, and the CJ2 coil working, its contact CJ2 closure, arc ignition circuit work, indicator lamp L3 is bright simultaneously.

4. also install another indicator lamp L4 in the primary wire of striking transformer B3, such as one with the neon tube of parallel connection of primary windings, L4 is bright during striking work.

5. cutting work shows: in the primary wire of transformer B2, be connected in series a light emitting diode L5-1 with described photoelectrical coupler receiving terminal 2, with described controllable silicon 3 neon tube L5-2 in parallel, during described receiving terminal 2 conductings, L5-1 is bright; Neon tube L5-2 extinguishes during described controllable silicon 3 conductings, and the expression cutting is normally carried out; When bright and L5-2 was also bright as L5-1, expression controllable silicon 3 had triggering signal but not conducting, illustrates that fault is on controllable silicon 3; If L5-1 does not work, L5-2 is still bright, represents that then photoelectrical coupler work is undesired.

6. major loop short circuit indication: the output at control module comparator A1 connects a light emitting diode L6 control circuit, and when the major loop short circuit, comparator A1 is output as high potential, and the L6 conducting is luminous.

Because the utlity model has above-mentioned series of displays function, thus the duty of energy display circuit each several part, helping finding timely and accurately guilty culprit, Operation and Maintenance is all very convenient.

Another distinguishing feature of the utility model cutting machine is that complete machine is combined by each functional module, and module has frontplane cell 8, main loop unit, main transformer B1 and control circuit unit; Attaching plug, gauge tap and indicator lamp are housed on the frontplane cell; Main loop unit is installed on the cutting machine rear board, and main circuit power, fan M and gas pressure reducer 9 are housed; Main transformer B1 is installed in the cutting machine middle part; The control circuit unit comprises striking transformer B3, B4 circuit and striking indicator lamp L4, electromagnetic valve of gas circuit 7, control circuit transformer B2, high-tension line plate 10 and low-voltage circuit plate 11; Bidirectional triode thyristor circuit and indicator lamp L5-1 and neon tube L5-2 are housed on the described hardboard, and arc ignition circuit relay CJ2; On the described low pressing plate low-voltage control circuit is housed, comprises voltage comparator A1, A2, A3, A4 and transistor T 1, T2, T3, T4 circuit, and indicator lamp L1, L2, L3.

Owing to have said structure, the utlity model has following outstanding advantages:

1. little, in light weight, the cost of machine volume.

2. have kinds of protect and Presentation Function, be convenient to control and maintenance.

3. adopt the functional module combining structure, simplified electrical wiring, be convenient to batch production and maintenance, more be conducive to produce series of products.

Claims

1, a kind of air plasma cutter comprises major loop, striking unit and the control module circuit installed in casing and the casing; Major loop comprises three-phase power line, main transformer, rectification and cutting torch electrode output circuit; The striking unit comprises high-frequency high-voltage circuit with step-up transformer B3 and the transformer B4 that is coupled with major loop output; Control module comprises control power transformer B2, arc ignition circuit, electromagnetic valve of gas circuit and various display control circuit, it is characterized in that: between high-tension circuit and low-voltage circuit, being provided with photoelectrical coupler isolates and the signal transmission to carry out high-low pressure, its circuit bank becomes: 380 volts of AC powers are through transformer B2 step-down, again through rectification output supply control module circuit, the transmitting terminal 1 of described photoelectrical coupler is serially connected with on transistor T 1 branch road of control circuit, and its receiving terminal 2 is connected in the primary wire of transformer B2; The branch road that this primary wire also in parallel is in series by a main circuit power contactor CJ1 coil and a two-way controllable silicon 3, the trigger end of this controllable silicon 3 links to each other with the receiving terminal of described photoelectrical coupler 2; During cutting machine work, transistor T 1 conducting, photoelectrical coupler work, controllable silicon 3 conductings, CJ1 adhesive, main circuit power conducting.

2, air plasma cutter as claimed in claim 1, it is characterized in that also being provided with short-circuit protection circuit, it consists of: two current transformer B5, B6 are installed in respectively on the two-phase power supply line of main circuit power, its output links to each other with the input of the bistable voltage comparator A1 of control circuit through rectification and OR circuit, and another input of comparator A1 is a reference voltage; The aforementioned transistor T 1 that links to each other with the transmitting terminal 1 of photoelectrical coupler of output control of comparator A1; When source current transshipped, the output of comparator A1 made transistor T 1 not work by, photoelectrical coupler, and controllable silicon 3 not conductings, CJ1 contact disconnect, and main circuit power cuts off.

3, air plasma cutter as claimed in claim 2 is characterized in that being equiped with duty and fault display device, comprising:

1. the compressed air ventilation shows: electromagnetic valve of gas circuit coil 7 is connected with transistor T 2, is connected in the control module coil 7 ventilation indicator lamp L1 in parallel; During ventilation, transistor T 2 conductings, coil 7 work, indicator lamp L1 is bright;

2. cutting work shows: on the series arm of described photoelectricity coupling transmitting terminal 1 and transistor T 1, and serial connection one cutting relay indicating light L2, when normally cutting, indicator lamp L2 is bright;

3. striking work shows: arc ignition control circuit comprises a voltage comparator A3, the input of comparator A3 is a reference voltage, another input is controlled by the cutting torch K switch, a transistor T 4 is controlled in the output of comparator A3, this transistor T 4 is connected with striking relay coil CJ2, is connected in the control circuit; Two CJ2 normal opened contacts are located at respectively in the guard shield circuit of the primary wire of arc ignition circuit transformer B3 and major loop, a striking indicator lamp L3 in parallel on described CJ2 coil; When the cutting torch K switch was closed, comparator A3 was output as high potential, transistor T 4 conductings, and the CJ2 adhesive, arc ignition circuit work, indicator lamp L3 is bright simultaneously;

4. in the primary wire of striking transformer B3, also and meet a neon tube L4, when striking was carried out, L4 was bright;

5. in the primary wire of described transformer B2, be connected in series a light emitting diode L5-1 with described photoelectrical coupler receiving terminal 2, with described controllable silicon 3 neon tube L5-2 in parallel, during 2 conductings of photoelectrical coupler receiving terminal, L5-1 is bright; Neon tube L5-2 extinguishes during controllable silicon 3 conductings, and during controllable silicon 3 not conductings, L5-2 is bright;

6. at the output of control module comparator A1, connect an indicator lamp L6 control circuit, when the major loop short circuit, comparator A1 is output as high potential, and the L6 conducting is luminous.

4, air plasma cutter as claimed in claim 3 is characterized in that complete machine is combined by a plurality of functional modules, and module comprises front panel, major loop, main transformer and control circuit unit.

5, air plasma cutter as claimed in claim 4, it is characterized in that also being equiped with the cutting torch short-circuit protection circuit, it consists of: between electrode shield 5 and major loop direct current output ground terminal, be connected to a cutting torch short-circuit protection relay coil CJ4, a low-resistance high-power resistance R2 in parallel with this coil CJ4; The CJ4 normally closed contact is serially connected on controllable silicon 3 branch roads of described transformer B2 primary wire; When guard shield 5 and electrode 6 short circuits, boost on the resistance R 2, coil CJ4 work, the CJ4 normally closed contact disconnects, and main circuit power cuts off.