JPH08110048A - Ignition method of preheated flame - Google Patents

Abstract

PURPOSE: To make it possible to ignite preheated flames definitely and in a short time. CONSTITUTION: This ignition method is so designed that the formation state of preheated flames is monitored with an infrared detection unit 4 which is installed near a gas torch 1 while an automatic ignition operation of a pilot fire nozzle 2 is executed in a continuous mode until a pre-heated gas is ignited and preheated flames 23 are formed to a satisfactory extent.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for igniting a preheating flame of a gas processing apparatus which is automatically operated by a program.

[0002]

2. Description of the Related Art Recently, a gas processing apparatus is automatically operated in accordance with a preset program, and even when a preheating flame is ignited on a gas torch, the automatic ignition is automatically ignited to save labor or unmanned technology. Development is in progress.

When igniting a preheated flame by an automatic ignition device, first, a mixed gas of air and a combustible gas is circulated to a pilot crater by opening and closing a solenoid valve, and sparks are generated by using a high frequency ignition to ignite the pilot crater. Ignite. Then, at the same time as the operation of the ignition, a preheating gas in which oxygen gas and a combustible gas are mixed is circulated through a gas torch by opening and closing a solenoid valve, and the preheating gas is ignited by a pilot flame formed in the pilot crater to preheat the tip nozzle of the gas torch. It is configured to form a flame.

For example, according to the technique disclosed in Japanese Patent Application No. 5236310, which the present applicant is currently applying for a patent, the ignition part of the ignition device of the pilot crater is arranged at a position apart from the nozzle of the gas torch. By doing so, it was possible to improve the ignition rate of the pilot crater, which made it possible to improve the ignition rate of the preheating flame.

However, even if the above technique is used, if an unexpected mechanical or electrical failure occurs, the pilot crater cannot be reliably ignited by one spark,
The preheating flame may misfire.

Therefore, in order to solve the above-mentioned problems, conventionally, as shown in FIG. 4, a period of a predetermined time T4 (for example, about 5 seconds) is maintained by a timer operation after the automatic ignition device starts an ignition operation. Program setting is performed in advance so that the ignition operation is repeated and continued.

That is, in FIG. 4, at the arbitrary time t1, the preheated gas is passed through the gas torch and at the same time, the automatic ignition device is operated. At this time, in the automatic ignition device, the operation of the high-frequency ignition is repeated a plurality of times with the mixed gas flowing through the pilot crater to intermittently continue the spark generation. Then, this state is set for a predetermined time T4.
It continues for (from time t1 to t4).

The preheating flame is ignited at an unspecified time t2 (t1 <t2 <t4) within the range of time T4. Then, even after the preheating flame is completely ignited at time t2, the automatic ignition device continues the ignition operation until time t4, and the ignition operation of the automatic ignition device is started only at time t4 when the set time T4 of the timer ends. To stop. When the set time T4 has passed, the next machining operation programmed in advance is immediately started. In addition, after the time t7, the preheating is completed and the preheating flame is extinguished.

[0009]

However, even if the above-mentioned technique is used, an unexpected mechanical or electrical failure occurs, and this state causes a time T4 during which the automatic ignition device continues the ignition operation. If it exceeds, there is a problem that the preheating flame cannot be ignited. In this case, if the preset ignition operation time T4 elapses, the preheating flame may move to the next operation in a non-ignited state, and it may become impossible to cut by, for example, a cutting process.

During the ignition operation, sparks generated by operating the high frequency ignition of the automatic ignition device generate electrical noise such as high frequency noise. If the noise is generated for a long time, the noise may adversely affect an electric control system such as an NC control device that controls the device and cause a malfunction.

In the above technique, even after the preheating flame is completely ignited, the automatic ignition device is configured to continue the ignition operation until the preset time T4 elapses. Continues for a preset time T4. If the ignition operation time T4 is set to be long for the purpose of ensuring the reliability of ignition, the noise continues for a long time, which is not preferable for the control system such as the NC control device.

A preheating flame ignition method according to the present invention is intended to provide a preheating flame ignition method capable of reliably igniting a preheating flame in a short time.

[0013]

A method for igniting a preheating flame according to the present invention is a method for igniting a preheating flame of a gas processing apparatus which is automatically operated by a predetermined program, in which the formation state of the preheating flame is monitored by an infrared sensor. The automatic ignition operation of igniting the preheated gas is continuously executed until the infrared sensor recognizes the state where the preheated flame is completely formed.

[0014]

Since the preheating flame ignition method according to the present invention is constructed as described above, the formation state of the preheating flame is monitored by the infrared sensor when the preheating gas is ignited. Then, the automatic ignition operation is executed until the infrared sensor recognizes that the preheating flame is completely ignited. Immediately after the infrared sensor recognizes the ignition of the preheating flame, the ignition operation of the automatic ignition device is immediately terminated, and the preheating flame is ignited in a short time and reliably by shifting to the next operation programmed in advance. Can be done.

Further, since the preheating flame is detected by the infrared sensor, the presence or absence of the flame can be directly detected to surely recognize the preheating flame.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the preheating flame ignition method according to the present invention is applied to a gas cutting apparatus will be described with reference to the drawings. FIG. 1 is a diagram showing a configuration of a gas torch provided with an automatic ignition device and an infrared detection unit to which the preheating flame ignition method of the present invention can be applied, and FIG. 2 is a gas cutting apparatus to which the preheating flame ignition method of the present invention can be applied. 3 is a block diagram showing a control system for forming the preheating flame, and FIGS. 3 (a) and 3 (b) are graphs showing the ignition operation of the automatic ignition device and the timing at which the preheating flame ignites.

First, the structure of a gas torch provided with an automatic ignition device and an infrared detection unit to which the preheating flame ignition method according to the present invention can be applied will be described with reference to FIGS. 1 and 2. In FIG. 1, a pilot crater 2 serving as an automatic ignition device is arranged near a gas torch 1 at predetermined positions by supporting members 3a and 3b, and an infrared detection unit 4 near the gas torch 1 is fixed by supporting members 5a and 5b. Placed in position.

The pilot crater 2 is a conduit 6 for flowing a mixed gas of fuel gas and air, and a valve for adjusting the flow rate of the fuel gas upstream of the conduit 6 to adjust the flow rate of the mixed gas flowing in the conduit 6. 7 and an injector 8 formed between the conduit 6 and the valve 7 and having an air hole for sucking air in the atmosphere to generate a mixed gas of fuel gas and air, and between the injector 8 and the conduit 6. An electrode 9 for arranging and igniting the mixed gas, a flame forming member 10 detachably attached to the nozzle portion 6a of the conduit 6, and the like.

Further, the infrared detecting unit 4 is provided with a lens unit and the like, a detecting section 11 for detecting the infrared ray amount in the infrared region of the flame, an optical fiber cable 12 connected to the detecting section 11 for transmitting the detected infrared ray, and the optical fiber. The signal converter 13 is connected to the cable 12 and converts the detected infrared information into an electric signal.

As shown in FIG. 2, solenoid valves 17a and 17b and solenoid valves 18a and 18b are provided upstream of the preheating fuel valve 14 and the preheating oxygen valve 15 provided in the gas torch 1, respectively. The electromagnetic drive units of the solenoid valves 17a, 17b, 18a, 18b are connected to the control unit 19, respectively.

Here, the solenoid valves 17a and 18a are configured to form a so-called neutral flame when the preheating flame 23 formed at the tip of the nozzle 1a of the gas torch 1 burns in a normal state according to a predetermined combustion reaction formula. It is configured to open and close the first preheating gas supply path in which the mixing ratio of the fuel gas and the oxygen gas is set to a predetermined value.

The solenoid valves 17b and 18b are provided with a fuel gas and an oxygen gas so that the preheating flame 23 can form a strong oxidizing flame by increasing the mixing ratio of the oxygen gas by a predetermined value as compared with the neutral flame. It is configured to open and close the second preheating gas supply path in which the mixing ratio is set to a predetermined value.

Therefore, the solenoid valves 17b and 18b are shut off to make the second
Solenoid valves 17a, 18a with the preheating gas supply path of
When the preheating flame 23 is formed at the tip of the nozzle 1a of the gas torch 1 by opening the valve to open the first preheating gas supply path, the preheating flame 23 becomes a neutral flame, and on the contrary, the solenoid valves 17a and 18a are shut off. When the first preheating gas supply path is shut off, the solenoid valves 17b and 18b are opened to circulate the second preheating gas supply path, and the preheating flame 23 is formed at the tip of the nozzle 1a of the gas torch 1. The preheating flame 23 becomes a strong oxidizing flame.

Further, solenoid valves 20 and 21 are provided upstream of the disconnecting oxygen valve 16 provided in the gas torch 1 and the valve 7 provided in the pilot crater 2, respectively. The drive units are connected to the control unit 19, respectively.

The solenoid valves 17a, 17b, 18a,
18b, 20, and 21 are automatically controlled by the control unit 19 according to a predetermined program to control the flow of each gas.

A high voltage generator 22 having an ignition coil or the like is connected to the electrode 9, and the high voltage generator 22 is connected to the controller 19. The control unit 19 can operate the high voltage generator 22 to generate a spark on the electrode 9.

Further, the signal converter 13 of the infrared detection unit 4
Is connected to the control unit 19 and detects the presence of the preheating flame 23.
When 11 detects, flame recognition information corresponding thereto is transmitted from the signal converter 13 to the control unit 19.

The control unit 19 has N for performing a predetermined disconnection.
It has an automatic plumbing device for programming a C cutting program, an operation execution unit for executing the program, an input unit for inputting cutting information to the NC cutting program, and the like. And the distribution and interruption of each gas to be supplied to the gas torch 1 and pilot crater 2,
Then, each device can be controlled in accordance with a preset program, such as operating the high voltage generator 22 corresponding to the gas flowing through the pilot crater 2 to generate a spark on the electrode 9.

A method for forming the preheating flame 23 in the gas torch 1 of the gas cutting apparatus configured as described above is shown in FIG.
A description will be given using (a) and (b). First, valves 7,1
4, 15, 16 are set in advance to the optimum predetermined positions for performing the ignition operation or the cutting process.

Then, an operation panel (not shown) is operated to activate the ignition switch. Then, at an arbitrary time t1, the control unit
Reference numeral 19 causes the solenoid valves 17b and 18b to open to eject a preheated gas having a predetermined mixing ratio for forming a strong acid flame from the nozzle 1a of the gas torch 1. At this time, the solenoid valves 17a and 18a are in a closed state.

At the same time, the control unit 19 controls the solenoid valve 21.
Is opened and a mixed gas in which a combustible gas and air are mixed at a predetermined mixing ratio is ejected from the tip of the flame forming member 10 of the pilot crater 2.

At the same time, the control unit 19 repeatedly operates the high voltage generator 22 to intermittently generate a spark on the electrode 9.

Then, for example, in FIG. 3B, time t3,
In FIG. 3A, the preheating flames 23 are completely ignited at time t5, respectively, and it is recognized by the infrared detection unit 4 that the preheating flames 23 are formed, and the flame recognition information is transmitted to the control unit 19. The ignition procedure of the preheating flame 23 at this time is that the spark generated by the electrode 9 causes the pilot flame on the pilot crater 2.
24 is formed, and the preheating flame 23 ignites the preheating gas by the pilot flame 24.

At this time, the infrared detecting unit 4 detects the amount of infrared rays of the preheating flame 23 formed at the tip of the nozzle 1a of the gas torch 1, and the formation state of the preheating flame 23 is transmitted to the control section 19. Here, the detection unit 11 of the infrared detection unit 4 is set so that it is aimed near the tip of the preheating flame 23 formed in the nozzle 1a of the gas torch 1.

When a signal recognizing that the preheating flame 23 has been formed is transmitted to the control unit 19, the control unit 19 causes the high voltage generator to operate.
22 is stopped to stop the spark generation of the electrode 9, and the solenoid valve 21 is shut off to stop the flow of the flammable gas to the pilot crater 2.

Usually, since the temperature of the material to be cut is low at the start of cutting, the preheating flame 23 is generally composed of a strong acid flame. By doing so, the combustion oxidation reaction with respect to the material to be cut can be forcibly promoted and the cutting time can be shortened. Then, when the temperature of the cutting portion of the material to be cut reaches the cutting temperature, the electromagnetic valve 20 of the cutting oxygen valve 16 is opened to inject the cutting oxygen from the nozzle 1a of the gas torch 1 to perform the cutting process.

At this time, the preheating flame 23 is generally switched from a strong acid flame to a neutral flame. If the preheating flame 23 is subjected to a cutting process in a strong acid flame state, the cutting site of the material to be cut causes an excessive oxidation reaction and is melted and damaged, resulting in poor cutting.

When converting the preheating flame 23 from the strong acid flame to the neutral flame, the control unit 19 shuts off the solenoid valves 17b and 18b shown in FIG. 2 and at the same time opens the solenoid valves 17a and 18a. As a result, the mixing ratio of the combustible gas and the oxygen gas is converted from the mixing ratio of the strong acid flame to the mixing ratio of the neutral flame, and the preheating flame 23 is converted from the strong acid flame to the neutral flame.

When the preheating flame 23 is converted as described above, the preheating flame 23 may be extinguished due to a temporary pressure fluctuation of the preheating gas when the preheating flame 23 is converted. Further, at this time, the preheating flame 23 is not changed transiently from the strong acid flame to the neutral flame, but is converted at once, and the preheating flame 23 becomes unstable in maintenance, and there is a risk of extinguishing the fire.

When the preheating flame 23 thus formed is extinguished, the preheating flame 23 can be re-ignited by operating the automatic ignition device again. For example, as shown in FIG. 3B, after the preheating flame 23 is ignited at time t3, the solenoid valves 17b and 18b are shut off at the time t5 and at the same time the solenoid valves 17a and 18a are shut off.
If the preheating flame 23 is extinguished when is opened, the infrared detection unit 4 detects the extinction of the preheating flame 23 and transmits it to the control unit 19.

Then, the control unit 19 shuts off the electromagnetic valve 20 to stop the flow of the cutting oxygen, and then opens the electromagnetic valve 21 to eject the mixed gas from the pilot crater 2 as described above.
At the same time, the controller 19 causes the high voltage generator 22 to intermittently and continuously generate sparks on the electrodes 9.

Then, at time t6, the preheating flame 23 is completely ignited. Then, when the infrared detection unit 4 detects the amount of infrared rays of the preheating flame 23 and a signal recognizing that the preheating flame 23 is formed is transmitted to the control unit 19, the control unit 19 stops the high voltage generator 22. And the spark of the electrode 9 is stopped, and the solenoid valve 21 is shut off to stop the flow of the flammable gas to the pilot crater 2.

Then, the solenoid valve 20 is opened to open the gas torch 1.
The cutting oxygen can be jetted from the nozzle 1a to perform the cutting process on the material to be cut according to the cutting program.

3 (a) and 3 (b) show changes with time in the ignition operation of the above-mentioned preheating flame 23, and t4 and T4 show time and time for comparison with the conventional example. FIG. 3 (a)
At the time t1, when the preheating gas is jetted and the automatic ignition device is operated, the preheating flame 23 is completely ignited at the time t5, and the infrared detection unit 4 detects that the preheating flame 23 is ignited. The figure shows the situation when the automatic ignition device is stopped by the above. The operating time T1 of the automatic ignition device operates longer than the conventional operating time T4, and the preheating flame 23 can be reliably ignited.

FIG. 3B shows an arbitrary time t similar to the above.
When the preheating gas was jetted to 1 and the automatic ignition device was operated, the preheating flame 23 was completely ignited at time t3, and the infrared detection unit 4 detected that the preheating flame 23 was ignited and the automatic ignition device was activated. The figure shows the situation when stopped.
In this case, the operating time T2 of the automatic ignition device is shorter than the operating time T4 of the related art, the generation time of electrical noise due to high frequency ignition is shortened, and it is possible to reduce the adverse effect on the electric control system such as the NC control device. Is.

Further, in FIG. 3 (b), the preheating flame 23 once formed is extinguished at time t5, the infrared detecting unit 4 detects that the preheating flame 23 has extinguished, and activates the automatic ignition device. When the automatic ignition device operates for T3 hours, the preheating flame 23 is completely ignited at time t6, and the infrared detection unit 4 detects that the preheating flame 23 has ignited and stops the automatic ignition device. ing. In this way, since the infrared detection unit 4 constantly monitors the ignition state of the preheating flame 23, even if the preheating flame 23 is extinguished for some reason, the automatic ignition device is restarted as described above to reliably ignite the preheating flame 23. It can be done.

Therefore, when the preheating flame 23 is extinguished for some reason, it is not necessary to stop the entire apparatus and perform the ignition operation from the ignition start as in the conventional case, and the preheating flame 23 is immediately extinguished automatically. The preheating flame 23 can be re-ignited by operating the device, and the work efficiency is improved.

3A and 3B, after the time t7, the preheating is completed and the preheating flame 23 is extinguished.

In the above embodiment, the operating time of the automatic ignition device is set to be the time until the preheating flame 23 is detected by the infrared detecting unit 4, but the unit operating time is a predetermined time (for example, about 5 seconds). The recognition signal which is set as Ts and the infrared detection unit 4 detects the preheating flame 23 is a control signal.
The unit operation time Ts may be repeatedly extended until it is transmitted to.

Also, the maximum operating time Te of the automatic ignition device is
(For example, about 30 seconds) is set, and when the maximum operation time Te is exceeded, it is possible to stop all operations once and notify the operator of the abnormality of the apparatus.

In the above embodiment, the case where the preheating flame ignition method according to the present invention is applied to the gas cutting device has been described, but it is applied to other gas processing devices such as scarfing, gouging and welding. It is also possible.

[0052]

Since the preheating flame ignition method according to the present invention has the above-described structure and operation, the ignition operation is performed by the automatic ignition device until the infrared sensor recognizes that the preheating flame is completely formed. By continuing, the preheating flame can be reliably ignited.

Therefore, as in the conventional case, when the preset ignition operation time elapses, the preheating flame does not shift to the next operation in the unignited state and the processing becomes impossible, so that the gas processing is automatically operated. The reliability of the device is improved and the work efficiency is improved.

Further, as soon as the infrared sensor recognizes that the preheating flame has ignited, the automatic ignition device can be stopped and the processing operation can be shifted to the next processing operation. Therefore, the working speed is improved, and at the time of sparking due to the high frequency ignition of the automatic ignition device. The electrical noise generation time can be shortened, and the adverse effect of the noise on the control system such as the NC control device can be reduced.

Even when the preheating flame is extinguished due to fluctuations of the preheating flame or when the preheating flame is extinguished for some reason when converting the preheating flame from a strong acid flame to a neutral flame, the automatic ignition device can be restarted to reignite the preheating flame. , Work efficiency is improved.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a gas torch provided with an automatic ignition device and an infrared detection unit to which the preheating flame ignition method of the present invention can be applied.

FIG. 2 is a block diagram showing a control system for forming a preheating flame of the gas cutting device.

3 (a) and 3 (b) are graphs showing an ignition operation of the automatic ignition device and a timing at which a preheating flame is ignited.

FIG. 4 is a diagram illustrating a conventional example.

[Explanation of symbols]

1 ... Gas torch, 1a ... Nozzle, 2 ... Pilot crater,
3a, 3b ... Support member, 4 ... Infrared detection unit, 5
a, 5b ... Support member, 6 ... Conduit, 6a ... Nozzle part, 7 ...
Valve, 8 ... Injector, 9 ... Electrode, 10 ... Flame forming member, 11 ... Detecting part, 12 ... Optical fiber cable, 13 ... Signal converter, 14 ... Preheating fuel valve, 15 ... Preheating oxygen valve, 16 ... Cutting oxygen Valve, 17a, 17a, 18a, 18b ... Solenoid valve, 19 ... Control part, 20, 21 ... Solenoid valve, 22 ... High voltage generator, 23 ... Preheating flame, 24 ... Pilot flame

Claims (1)

[Claims] 1. A method of igniting a preheating flame of a gas processing apparatus which is automatically operated according to a predetermined program, wherein the formation state of the preheating flame is monitored by an infrared sensor, and the infrared sensor indicates the state where the preheating flame is completely formed. A method for igniting a preheating flame, characterized in that it is configured to continuously execute an automatic ignition operation of igniting a preheated gas until it is recognized.