JPH029244Y2 - - Google Patents

Description

[Detailed Description of the Invention] "Field of Industrial Application" The present invention relates to an improvement of a welding burner.

``Prior Art'' Traditionally, welding burners have two hoses connected to the rear end of the grip, with the rear end of one hose connected to an oxygen or air cylinder, and the rear end of the other hose connected to a fuel such as acetylene. An oxygen flow path and a fuel flow path connected to the cylinder, connected to the ends of both hoses, and passing through the gripping portion are connected to the nozzle body through flow rate regulating valves, respectively.

``Problems to be solved by the invention'' However, the conventional welding burner described above is difficult to solve due to the operating conditions, specifically the temperature rise of the nozzle body, the large difference in the amount of oxygen and fuel supplied, and the difference between the nozzle opening and It is known that the flame that should originally be injected outward from the nozzle body may flow backwards depending on the distance from the object to be welded.

Normally, this backflow of flame ends instantly and does not lead to a major accident, but the flame may also flow back to the hose, and in this case, there is a good chance that the hose will melt due to high heat and cause a major accident. be.

Therefore, the present invention was developed in view of the above-mentioned drawbacks, and if the flame flows back into the burner body, this backflow is reliably blocked in the downstream part of the burner body, and the fuel is also discharged using a solenoid valve in the upstream part. The object of the present invention is to provide a welding burner whose outlet can be automatically closed.

``Means for Solving the Problems'' In line with the above-mentioned purpose, the configuration of the present invention, which has the gist of the above-mentioned utility model registration claims, is to solve the above-mentioned problems when electricity is applied to the discharge port of the fuel gas cylinder 20. The hose 11 is connected via a solenoid valve 52 that opens, and the burner body 30 attached to the tip of the hose 11 has a manual switch 55 in the grip part 33, and the tip nozzle body 31 has a manual switch 55 that turns off when the temperature exceeds a predetermined temperature. A thermo switch 56 is provided, and a conductive wire 51 of low strength is embedded or attached to the hose 11 so as to be cut together when the hose 11 is cut. are interposed in series in the middle to form an energizing circuit to the solenoid valve 52, and the fuel gas flow path 23 of the burner body 30
In the middle, there is a valve 44 that is biased by a spring 45 in a direction to shut off the fuel gas flow path 23, and a valve push rod 47 that pushes the valve 44 open against the bias of the spring 45 and loses it at a predetermined temperature. This technical means is provided with a flame backflow prevention device 40 consisting of the following.

``Function'' Therefore, the welding burner of this invention has nozzle opening 3.
If the flame flows backward into the fuel gas flow path 23 from 2,
The valve push rod 47 is lost due to the flame, and the valve 44 is closed by the force of the spring 45 to block the fuel gas flow path 23 and prevent the flame from flowing back further upstream.

In addition, since the backflow speed of the flame is quite fast, the backflow may advance upstream from the burner main body 30, but in this case, the thermoswitch 56 is activated to shut off the solenoid valve 52 and supply fuel. It has the effect of stopping the flow and preventing backflow.

``Example'' Hereinafter, the present invention will be described in more detail based on an example shown in the accompanying drawings.

In the figure, 30 is a burner main body, which has a grip part 33.

Two hoses 11 are provided at the rear end of the gripping portion 33,
21 are connected, the rear end of one hose 11 is connected to the spout of an oxygen or air cylinder 10, and the rear end of the other hose 21 is connected to a fuel gas cylinder 20 such as acetylene.
They are connected to the respective discharge ports.

Inside the gripping part 33, an oxygen flow path 13 and a fuel gas flow path 23, which communicate at their distal ends with the nozzle body 31 located ahead of the gripping part 33, are passed, and the oxygen flow The tips of both the hoses 11 and 21 are connected to the rear ends of the passage 13 and the fuel gas flow passage 23, respectively. Further, flow rate regulating valves 12, 22a, 22b are provided in the middle of the oxygen flow path 13 and the fuel gas flow path 23.
The layout is the same as before.

In the present invention, the hose 11 is connected to the discharge port of the fuel gas cylinder 20 via a solenoid valve 52 that opens when energized, and the burner main body 30 attached to the tip of the hose 11 has a grip part 33 that allows manual operation. The switch 55 is provided with a thermoswitch 56 that turns off when the temperature exceeds a predetermined temperature on the tip nozzle body 31, and a conductive wire 51 of low strength is embedded in the hose 11 so as to be cut together when the hose 11 is cut. The conductive wire 51 has the switch 55 and the thermoswitch 56 interposed in series therebetween to form an energizing circuit for the electromagnetic valve 52.

In this embodiment, the hose 11 is also connected to the discharge port of the air cylinder 10 via another solenoid valve 54 that opens when energized.
0 is connected to one side of the solenoid of the solenoid valve 52, and the other side of the solenoid is connected to the hose 2.
burner main body 30 via a conductive wire 51 along
It is grounded to. Further, the output on the other side of the power supply box 50 is connected to one side of the solenoid of the electromagnetic valve 54, and the other side of the solenoid is connected to the burner via a conductive wire 53 along the hose 11, a switch 55, and a thermoswitch 56. It is grounded to the main body 30, and when in use, a switch 55 is turned on and electricity is supplied to both solenoid valves 52 and 54 to supply air and fuel gas to the downstream side of the hoses 21 and 11.
If the burner body 30, especially the nozzle body 31, becomes abnormally high temperature (it is known that flame backflow phenomenon frequently occurs when the nozzle body 31 reaches 300°C or higher), the electromagnetic valves 52, 54 The supply of air and fuel gas is stopped by cutting off electricity to the fuel tank.

Further, in the present invention, a flame backflow prevention device 40 is interposed in the middle of the fuel gas flow path 23.
This flame backflow prevention device 40, as most clearly shown in FIG.
a, and a valve seat portion 43 is provided between the inlet 23b and the outlet 32a. A valve 44 is housed within the main body 41, and the valve 44 is biased by a spring 45 in the direction of closing the valve, that is, in the direction of blocking the fuel gas flow path 23. This valve 44 also has a valve rod 4 that passes through the valve seat portion 43.
6 is provided in a protruding manner, and a valve pusher rod 47 is disposed toward the distal end of the valve rod 46.

The valve pusher rod 47 is made of a material that loses heat at a predetermined temperature, and is adapted to push open the valve rod 46 to the valve 44 against the force of the spring 45. A celluloid rod or the like is suitable as a material that loses water at a predetermined temperature, and by applying a loss aid such as sulfur to the surface, a valve pusher rod 47 that instantly burns out at 250 to 300°C was obtained. In this embodiment, the valve push rod 47 protrudes from the protective tube 42 by a predetermined length, and the protruding portion from the protective tube 42 is burnt out at once. A push screw 48 is disposed so that the valve pusher rod 47 can be pushed out by the burnt-out amount by the threading of this push screw, but this push screw 48 is a feeding mechanism known as a lead pushing mechanism of a sharp pencil. , once the push button is pressed, the valve push rod 4 will move a certain distance
7 may be sent out, or alternatively, it may be replaced with one that is not burned out but is lost due to melting or breaking.

[Effect of the invention] Since the present invention is as described above, even if the flame flows back into the burner body 30, if this flame reaches the flame backflow prevention device 40, the valve 44
It is possible to provide a welding burner that can close and prevent backflow in the upstream direction, thereby preventing a major accident from occurring.

In addition, the present invention has a structure in which the valve 44 is pushed open by the valve pusher rod 47, so the structure is simple, the valve 44 responds reliably, and the only consumable is the valve pusher rod 47, so it is safe and economical to weld. It is possible to provide a burner for In particular, the structure in which the valve 44 is pushed open with the valve pusher rod 47 allows a sufficient movement distance of the valve 44 to be obtained, so that the pressure loss at the valve 44 portion can be set to be small, and as a result, the flow rate adjustment is adversely affected. It is something that cannot be given.

Further, in the present invention, the hose 11 is connected to the discharge port of the fuel gas cylinder 20 via a solenoid valve 52 that is opened when energized.
The burner main body 30, which is attached to the tip of the hose 11, has a manual switch 5 on a grip part 33.
5, when the tip nozzle body 31 reaches a predetermined temperature or higher.
A thermo switch 56 that turns off is provided, and
A conductive wire 51 of such low strength that it is cut together when the hose 11 is cut is embedded or attached to the hose 11. Since it forms an energizing circuit to the valve 52, by setting the operating temperature of this thermoswitch 56, backflow due to heating of the burner body 30 can be prevented, and backflow can be prevented from extending to the upstream side. It is possible to provide a welding burner that prevents this by closing the solenoid valve 52 even if the welding continues for a certain period of time.

[Brief explanation of the drawing]

FIG. 1 is a front view showing an embodiment of the welding burner of the present invention, and FIG. 2 is a sectional view of the main part. 11...Hose, 20...Gas cylinder, 23...
...Fuel gas flow path, 30...Burner body, 31...
... Nozzle body, 32 ... Nozzle mouth, 33 ... Gripping part, 40 ... Flame backflow prevention device, 44 ... Valve, 4
5... Spring, 47... Valve push rod, 51... Conductor, 52... Solenoid valve, 55... Switch, 56...
...Thermo switch.

Claims (1)

[Claims for Utility Model Registration] A hose 11 is connected to the discharge port of the fuel gas cylinder 20 via a solenoid valve 52 that opens when energized, and a burner body 30 attached to the tip of the hose 11 has a grip part 33. A manual switch 55 is provided at the tip nozzle body 31, and a thermoswitch 56 that turns off when the temperature exceeds a predetermined temperature is provided.The hose 11 is also embedded with a conductive wire 51 of such low strength that it will be cut when the hose 11 is cut. The conductive wire 51 forms an energizing circuit to the solenoid valve 52 by interposing the switch 55 and thermoswitch 56 in series, and also connects the fuel gas flow path 23 of the burner body 30.
In the middle, there is a valve 44 that is biased by a spring 45 in a direction to shut off the fuel gas flow path 23, and a valve push rod 47 that pushes the valve 44 open against the bias of the spring 45 and loses it at a predetermined temperature. A welding burner provided with a flame backflow prevention device 40 consisting of.