JPH0356738Y2 - - Google Patents

Description

[Detailed description of the invention] <Industrial application field> This invention applies to a cutting torch for gas cutting steel materials, and in particular, the backfire phenomenon that occurs during gas cutting occurs continuously within the cutting torch. The present invention relates to a gas cutting torch that can prevent this from occurring.

<Conventional technology> Conventionally, there are two types of mixing methods for preheating oxygen and fuel gas in gas cutting: an in-crater mixing type and an in-torch mixing type. Cutting torches are often used. If the tinder is pressed against the steel plate during gas cutting work using such a gas cutting torch, or if spatter generated during cutting adheres to the tinder,
The flame flows back to the gas mixture inside the torch, causing a flashback phenomenon within the torch. Sometimes, this flashback phenomenon can cause continuous combustion inside the torch, and in this case, it can lead to melting and damage of the cutting torch. It was hot.

Therefore, in order to reduce the frequency of occurrence of backfire, as shown in FIG.
There is a method of suctioning fuel gas by blowing out high-speed oxygen from the injector hole 3 of the injector hole 3, or as shown in Japanese Patent Application Laid-Open No. 58-224213, each part of the mixing part of oxygen and fuel gas is mixed at a constant ratio. A method in which a buffer is installed in the injector nozzle and the buffer absorbs abnormal pressure when flashback occurs to prevent flashback, as shown in Publication No. 61-17822. is being developed.

<Problems to be solved by the invention> However, the flashback phenomenon during gas cutting is not only caused by flashback to the gas mixture inside the torch as described above, but also by the condition of spatter attached to the tinder. The mixed gas may flow back into the cut oxygen pipe through the cut oxygen nozzle formed in the pipe, causing a flashback inside the pipe.

Furthermore, in the case of the technique shown in FIG. 5 described above, no consideration was given to the continuous flashback phenomenon in which combustion occurs continuously in the gas mixing section, so it was difficult to prevent this phenomenon. Also, JP-A-58-224213
The technique disclosed in the publication is effective when the flow rate of the mixed gas is small, but has problems such as being ineffective when the flow rate increases. In addition, Tokukai Akira
The technology shown in Publication No. 61-17822 is effective when used as a gas welding torch, but when used as a gas cutting torch, a buffer is provided only on the preheated oxygen supply passage side. There are problems such as not being able to prevent backfire on the cutting oxygen side, and with this technology, the injector cannot be attached to the main body without using special tools. There were also some problems.

The gas cutting torch according to the present invention relates to a completely new technology developed in view of these conventional problems.

<Means for solving the problems> The present invention incorporates a buffer in the preheating oxygen supply passage provided inside the injector capable of supplying preheated oxygen, and also incorporates a buffer in the outlet side supply passage for cutting oxygen. This is a gas cutting torch characterized by having a built-in.

<Function> As described above, the gas cutting torch according to the present invention has the following functions:
Backfire occurred because a buffer was built into the preheating oxygen supply passage provided inside the injector that could supply preheated oxygen, and a buffer was built into the outlet side supply passage for cutting oxygen. The shocking abnormal pressure that occurs at this time is absorbed by a buffer provided on the supply passage side of the preheating oxygen, thereby preventing the propagation of the abnormal pressure. The buffer also absorbs the abnormal pressure and prevents the abnormal pressure from propagating to the cutting oxygen supply passage, thereby reliably preventing the continuous flashback phenomenon within the gas cutting torch. .

<Example> An embodiment of the gas cutting torch according to the present invention will be specifically explained with reference to the drawings. In FIGS. 1 to 4, 4 is the main body of the gas cutting torch according to the present invention, and The oxygen supplied from the supply passage 5 is distributed to a cutting oxygen supply passage 6 and a preheating oxygen supply passage 7, respectively, and the oxygen distributed and supplied to these is supplied to a cutting oxygen valve 8 and a preheating oxygen supply passage, respectively. The oxygen valve 9 is configured to adjust the supply amount or supply pressure.

Further, the flow rate of the fuel gas is adjusted by a valve 10, and the fuel gas is configured to be supplied to the gas mixing section 12 through a fuel gas supply passage 11.

Further, at the tip of the torch 4, a head 13 is fixed to a cutting oxygen pipe 14 and a mixed gas pipe 15, and a nozzle 16 is detachably attached to the head 13 with a cap nut 17.

A porous air-permeable buffer 18 in the form of a metal filter, for example, made of sintered metal powder, is inserted into the outlet side of the cut oxygen supply passage 6, that is, on the crater side, and is held in a predetermined position by a nut 19. The cutting oxygen pipe 14 is fixed to the tip of the supply passage 6 on the crater side with a nut 20.

In addition, a buffer 21 is installed inside the preheated oxygen supply passage 7.
An injector 22 is attached. Further, the injector 22 is connected to the gas mixing section 12.
The gas mixing tube 25 is attached to the torch 4 by a screw 26. The mixed gas pipe 15 is attached to the other end of the gas mixing pipe 25 with a nut 27.

Here, the buffers 18 and 21 will be explained.

Figures A, B, and C show examples of the shock absorbers 18 and 21. Figure A is a metal cylinder with a plurality of holes a, and Figure B is a metal cylinder. A plurality of grooves b are carved on the outer periphery of a cylinder made of aluminum, and further, as shown in Fig. C, metal powder is sintered into a cylinder shape with a bottom and has porous air permeability. The above-mentioned examples all have similar buffering effects and can be used selectively. Further, the buffers 18 and 21 are not limited to the above-mentioned examples, and may be of any type as long as they can buffer the shocking abnormal pressure inside the torch caused by flashback.

Next, as shown in FIGS. 4A and 4B, the injector 22 has a screw 28 on its shoulder and can be easily attached to and detached from the mixing tube 25 with a spanner 30, which has a screw 29 that can be screwed into the screw 28. It is structured in such a way that it can be obtained. In the figure, a hole 31 formed in the mixing pipe 25 is a supply hole for supplying fuel gas to the gas mixing section 12.

The internal structure of the injector 22 is as shown in FIG. That is, the shock absorber 21 is inserted into the large diameter portion 22b formed inside the injector 22, and the fixing member 33 having the preheating oxygen supply hole 32 bored in the center thereof is screwed through the opening 22c of the injector 22. According to the buffer 21
is configured to be fixed at a predetermined position inside the injector 22.

In the present invention, as mentioned above, the buffers 18, 2
1 is built into the cutting oxygen supply passage 6 and the injector 22 in the preheating oxygen supply passage 7, respectively, so that the cutting oxygen pipe 1 can be inserted from the tip of the crater 16.
4 cut oxygen passage 23 or mixed gas pipe 1
When fire flows back into the gas mixing section 12 in the mixed gas passage 24 of No. 5 and a flashback phenomenon occurs, the shocking abnormal pressure generated due to the flashback is applied to the buffer 1.
8 and 21, and the abnormal pressure is applied to this buffer 1.
8 and 21 to prevent its propagation.

The flashback phenomenon in the cut oxygen passage 23 continues as long as the backflow of the mixed gas from the crater 16 continues, but in a state where the passage 23 is filled with combustion generated gas, that is, carbon dioxide gas and water vapor. Will it be?
Alternatively, the flashback phenomenon is stopped by preventing the backflow of the mixed gas from the crater 16.

Further, flashback in the mixed gas passage 24 occurs when the shocking abnormal pressure generated due to the flashback collides with the buffer 21 through the injector hole 22a of the injector 22, and the supply of preheated oxygen is cut off. At the same time, the abnormal pressure is
It also spreads to the side, cutting off the fuel gas supply.
The mixed gas passage 24 is filled with combustion generated gas, thereby stopping the flashback phenomenon.

When the flashback is extinguished and the abnormal pressure leaks from the crater 16, and the pressure in the cut oxygen passage 23 or the mixed gas passage 24 drops below the respective supply pressure,
Cutting oxygen or preheated oxygen is again supplied from the respective passages 6 and 7 through the numerous holes of the buffers 18 and 21 as usual, and furthermore, fuel gas is supplied from the fuel gas supply passage 11 to restart gas cutting. I can do it.

Here, since the buffer 21 is provided in the preheated oxygen supply passage 7 and there is no resistance provided on the fuel gas supply passage 11 side, the abnormal pressure is caused deeply in the fuel gas supply passage 11 side. propagate. Therefore, the supply of both gases is returned to the preheated oxygen earlier, the mixed gas passage 24 is cooled by the preheated oxygen ejected from the injector 22, the supply of fuel gas is restored, and the mixed gas passage 24 is filled with the mixed gas. However, no backfire will occur again.

At this time, the gas cutting operation can be promptly restarted by removing spatter etc. attached to the nozzle 16 or replacing the nozzle 16.

As mentioned above, the shocking abnormal pressure generated by flashback is buffered closer to the vent than the valves 8 and 9 and its propagation is prevented, so the abnormal pressure is applied to these valves 8 and 9. It does not act directly,
Therefore, destruction of these valves 8 and 9 can be prevented.

Further, since continuous combustion due to backfire within the torch 4 does not occur, it is possible to prevent the torch 4 from being eroded and damaged.

<Effects of the invention> As mentioned above, the gas cutting torch according to the invention has the following advantages:
Since buffers are provided in both the cutting oxygen supply passage and the preheating oxygen supply passage, these buffers can prevent flashbacks individually, thereby preventing the flashback phenomenon from occurring continuously. It is also possible to prevent the cutting oxygen or preheating oxygen valve from being destroyed due to backfire, and it is also possible to prevent the torch from melting. Furthermore, when a screw is provided on the shoulder of the injector, the injector can be easily attached to and detached from the mixing tube using a spanner.

[Brief explanation of drawings]

Figures 1 and 2 are cross-sectional views showing the main parts of the gas cutting torch according to the present invention, Figures 3A, B, and C are explanatory diagrams of the buffer, and Figures 4A and B are the injector and mixing tube. FIG. 5 is an explanatory diagram showing a conventional example. 1 and 4 are torch bodies, 5 is an oxygen supply passage, 6 is a cutting oxygen supply passage, 7 is a preheating oxygen supply passage, 8,
9 and 10 are valves, 11 is a fuel gas supply passage, 1
2 is a gas mixing part, 13 is a head, 14 is a cutting oxygen pipe, 15 is a mixed gas pipe, 16 is a crater, 1
8, 21 is a buffer, 22 is an injector, 22
a is the injector hole, 23 is the cut oxygen passage, 2
4 is a mixed gas passage, 25 is a gas mixing tube, 31 is a fuel gas supply hole, 32 is a preheated oxygen supply hole, and 33 is a fixing member.

Claims (1)

[Scope of utility model registration request] A gas cutting device characterized in that a buffer is built in a preheated oxygen supply passage provided inside an injector that can supply preheated oxygen, and a buffer is built in an outlet side supply passage for cutting oxygen. torch.