JPS6234112Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention does not ignite the flammable gas mixture necessary to start cutting work using a manually prepared igniter such as a lighter or a matchstick.
It is designed to make cutting easier by effectively utilizing the pressure energy of oxygen to activate the built-in automatic ignition mechanism. A crater in which conductive cylindrical bodies with an inner and outer heavy structure forming a flow path for a mixed gas of preheating oxygen and combustible gas are electrically insulated from each other and form spark electrodes at their tips; A torch head is provided, which has a flow path communicating with each flow path, and into which the crater is inserted and fixed in a detachable and replaceable manner, and the cutting oxygen flow path at the rear of the crater is provided with a torch head that allows the torches to collide with each other due to the cutting oxygen pressure. a piezoelectric mechanism that generates an electromotive force, and an actuator pullback mechanism that uses a magnet to return and hold the moving member of the piezoelectric mechanism to a standby position by cutting oxygen pressure; The present invention relates to a self-ignition gas cutting torch in which an electrode of a piezoelectric mechanism and the spark electrode are electrically connected.

With the torch configured as described above, the operation of igniting the flammable mixed gas at the start of cutting work is simpler than when using a manual igniter such as a conventional lighter, and the ignition timing is also easier to maintain at an appropriate level. Although it has the advantage of being safe and secure as there is no ignition error or explosive ignition, it has the problem of the following inconveniences occurring when ignition does not occur.

That is, the moving member of the piezoelectric mechanism built in the rear part of the crater is held at the standby position by the magnetic attraction force of the pull-back mechanism except for the ignition operation, and is in a state of blocking the cutting oxygen.
This is because the desired adsorption force cannot be obtained unless the magnet held by the moving member is in uniform contact with the magnetic contact surface such as an iron plate, so the precision of the contact surface between the two is made sufficiently high. This is a natural result since it is common. In addition, even if the contact surface accuracy during manufacturing is somewhat rough, if the moving member is repeatedly detached from and attracted to the contact surface by ignition operation, the surface accuracy will gradually improve, and the cutting oxygen barrier performance during non-ignition operation will improve. , the leakage there will be extremely small,
Therefore, the movable member exhibits the same function as a shutoff valve until a cutting oxygen pressure greater than the suction holding force acting on it is applied.

Therefore, if there is a leak in the valve controlling the cutting oxygen located upstream of the torch head, and the amount of leakage is greater than the amount of leakage at the contact surface, the flow between the control valve and the contact surface will be reduced. The cutting oxygen pressure in the passage section gradually rises, becoming greater than the adsorption and holding force of the magnet, and the movable member moves toward the fixed member in the same way as when the control valve is opened, causing an unexpected impact. is applied to the fixed member.
This phenomenon is inevitable unless the control valve has zero leakage.

If a large amount of flammable gas leaks near the area where the torch is used and the above phenomenon occurs, the resulting spark may become an ignition source and cause an explosion. If this situation occurs during the release of a flammable gas mixture, which is a preparatory step for ignition, the ignition may ignite unintentionally, causing the risk of unexpected burns. .

In view of these circumstances, the present invention aims to solve the above-mentioned problems that arise in devices with a built-in automatic ignition mechanism through extremely simple structural improvements.

A characteristic configuration of the automatic ignition type gas cutting torch according to the present invention, which has been made to achieve the above object, is that an upstream flow path portion near the contact surface between the movable member and the member that comes into contact when the movable member is in the standby position. and a pressure relief passage communicating with the flow path portion downstream of the contact surface, and the effects of the present invention having such a characteristic configuration are as follows.

That is, the cut oxygen for moving the movable member of the piezoelectric mechanism built in the rear part of the crater toward the other fixed member is released downstream of the valve when the control valve thereof is closed and the non-ignition operation is performed. When leaking to the side, the leaked oxygen can be discharged from the pressure relief path to the atmosphere through the cutting oxygen flow path of the crater and flowed, so that the leaked oxygen can flow between the control valve and the contact surface of the moving member. It is possible to reliably prevent the pressure from being accumulated in the passageway and gradually increasing. Moreover, the pressure relief passage is necessary only as a measure against leakage from the control valve, and its flow passage area may be very small. Therefore, when the control valve is opened and a predetermined ignition operation is performed, the pressure loss due to the existence of the pressure relief passage is small, and the cutting oxygen pressure necessary to detach the moving member against the suction holding force is maintained. , it is not necessary to raise the pressure by providing the pressure relief passage. In other words, while maintaining a state in which the cutting action can be performed reliably and well by suppressing as much as possible the increase in the cutting oxygen pressure to ensure that the movable member is detached during the ignition operation, the unexpected ignition action caused by the leakage of the control valve can be prevented. can be reliably prevented.

As mentioned above, the ignition operation can be simplified and automatic ignition can be performed reliably and safely without mistakes by making an extremely simple improvement such as providing a pressure release path.
It has now been possible to prevent unexpected ignition operations due to valve leakage, and the resulting dangers such as explosions and unintentional ignition during pre-ignition work.

An embodiment of the present invention will be described below in detail with reference to the drawings. Reference numeral a denotes a nozzle, and b represents a torch head into which the nozzle a is inserted and fixed in a detachable and replaceable manner via a threaded adapter 10. The crater a is made up of a conductive inner cylinder 2 made of copper or the like and a conductive outer cylinder 3 made of copper, which are concentrically fitted and have an inner and outer heavy structure. An annular combustible mixed gas flow path 1 is formed between the inner and outer circumferential surfaces of both 2 and 3, and a cutting oxygen flow path 32 is formed within the inner cylinder 2, and , each tip of the inner cylindrical body 2 and the outer cylindrical body 3 is formed into a pair of electrodes 4 and 5 constituting a spark point. The torch head b includes a combustible gas pipe 12, a combustion-supporting oxygen pipe 13, and a cutting oxygen pipe 14.
are connected and fixed in parallel in this order from the front to the rear, and each of these tubes 12,
13, 14, and a head section 29 having annular chambers 18, 19, and a head section 29 having flow paths 15, 16, 17 corresponding to the annular chambers 18, 19, and combustible gas and combustion-supporting oxygen supplied from both the annular chambers 18, 19. A conductive member 30 in which a flow path 20 is formed for guiding a flammable mixed gas obtained by mixing the gas into the flow path 1 in the crater a is provided at the rear of the crater a, and a conductive member 30 is provided at the rear of the crater a. A flow path 21 is formed in the center of the conductive member 30 to communicate the cut oxygen flow path 32 and the cut oxygen flow path 17 via a magnetic body 22 which also serves as a cylindrical valve seat. In the communication channel 21 at the rear of the crater a, one electrode 6 is attached to a cylindrical power receiving body 23 screwed to the rear end of the inner cylinder 2 at the crater a.
Of the two members 6 and 7 that constitute the piezoelectric mechanism in a state in which A is in constant contact with the other, one member, the piezoelectric unit 6, is fixed in position, and the holder 7A is non-magnetic and has excellent impact resistance. The actuator 7, which is the other member, is composed of a magnet 7B held by this and moves toward the piezoelectric unit 6 side when receiving the cutting oxygen pressure and acts on the other electrode 6B of the piezoelectric unit 6. Fitted and held so as to be movable back and forth between a standby position and an electromotive position along the core direction,
and a pull-back mechanism 8 for automatically returning the actuator 7 to the standby position and maintaining the position.
In addition to the magnet 7B and the magnetic body 22, a coil spring 24 is installed inside. a rear end portion of the inner cylindrical body 2 at the crater a and the power receiving body 23;
An insulator 25 is interposed between the corresponding conductive member 30 at the rear of the crater a, and one electrode 6A of the piezoelectric unit 6 is connected to one side via the power receiving body 23 and the inner cylinder 2. The other electrode 6B of the piezoelectric unit 6 is conductively connected to the other spark electrode 5 via the conductive member 30 and the outer cylindrical member 3. As clearly shown in FIGS. 1 and 4, a portion of the flow path 17 upstream near the contact surface between the actuator 7 and the magnetic body 22, which is a member that contacts when it is in the standby position, and the contact surface A pressure relief passage 9 communicating with the downstream flow passage 21 portion is bored in the conductive member 30 in a bypass shape. This depressurization passage 9 has enough cutting oxygen to separate the actuator 7 from the contact surface of the magnetic body 22 against the position holding force caused by the cooperation of the magnetic adsorption force and the elastic force of the spring 24 during the ignition operation. The area of the flow passage is as small as possible within the range where the pressure can be obtained and within the range where the pressure of the cutting oxygen that leaks and accumulates in the flow passage 17 during non-ignition operation does not rise and accumulate to the above-mentioned actuator withdrawal pressure. It is designed and configured. In the figure, reference numerals 26, 27, and 28 are control valves interposed in the middle of each of the aforementioned pipes 12, 13, and 14. Further, the conductive member 30 at the rear of the crater a is divided into two in the tube axis direction, and both divided members 3
0A, 30B are configured to be connectable and detachable via a cylindrical connector 31 that can be screwed to the adapter 10 and the head portion 29, thereby allowing the piezoelectric unit 6, the actuator 7, The structure is such that the spring 24 can be easily installed, replaced, etc.

The ignition procedure is as follows.

The control valves 26 and 27 are opened to send flammable gas and combustion-supporting oxygen, and a mixed gas of both flows out from the crater a.

Control valve 28 is opened to send cutting oxygen into flow path 17 . Then, the actuator 7 moves toward the piezoelectric unit 6 and collides with it to generate an electromotive force, which causes a spark to fly between the spark electrodes 4 and 5 at the tip of the nozzle a, thereby igniting the flammable mixed gas.

When the control valve 28 is closed, the actuator 7 automatically returns to the above-mentioned standby position due to the magnetic attraction force and the elastic force of the spring 24, contacts the magnetic body 22, and is maintained in the same operating state as a valve.

Next, another embodiment will be described.

[] The pressure relief passage 9 is formed from a notch provided in the cylindrical end of the holder 7A that holds the magnet 7B of the actuator 7, as shown in FIG. 5 A and B. It may also be a hole formed through the magnet 7B and holder 7A of the actuator 7, as shown in FIGS. 6A and 6B.

[] Although it is desirable that the conductive member 30 at the rear of the crater a be divided into two parts, it may be a single piece.

[] What is shown in FIG. 7 is the piezoelectric mechanism 6,
7, the piezoelectric unit 6 side is configured to be moved by cutting oxygen pressure, and in this case, a holder 7A is installed at the rear of the piezoelectric unit 6.
The magnet 7B is held via the magnet 7B.

[] As shown in FIG. 7, the crater a does not have the two-part electrically conductive member 30 shown in the above embodiment, and consists of the cylinders 2 and 3 with an inner and outer heavy structure and an insulator interposed between them. 11, and the combustible mixed gas flow path 1 may be formed in the outer cylindrical body 3 by swaging.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway side view, Fig. 2, Fig. 3, and Fig. 4 are Fig. 1 - lines, - lines, and -.
Figures 5A and 6A and 6A and 6B are longitudinal sectional side views of main parts showing different embodiments, respectively, and longitudinal sectional front views taken along the RO line in each figure. FIG. 7 is a longitudinal sectional side view showing yet another embodiment. DESCRIPTION OF SYMBOLS 1... Combustible mixed gas flow path, 2, 3... Conductive cylinder, 4, 5... Spark electrode, 6... Piezoelectric unit, 7... Actuator, 8... Pullback mechanism, 9...
Pressure release path, a...crater, b...torch head.

Claims (1)

[Scope of utility model registration request] A cut oxygen flow path 32 is provided in the center, and a mixed gas flow path 1 of preheating oxygen and combustible gas is provided on the outer periphery of the cut oxygen flow path 32.
A crater a in which conductive cylindrical bodies 2 and 3 having an inner and outer heavy structure are electrically insulated from each other and have spark electrodes 4 and 5 formed at their tips; Channels 17 and 21 communicating with 1
and 15, 16, and a torch head b for inserting and fixing the crater a in a removable and replaceable manner. piezoelectric mechanisms 6 and 7 that generate electromotive force and the piezoelectric mechanisms 6 and 7
Of these, the member 7 on the side that moves due to the cutting oxygen pressure
Alternatively, an actuator retracting mechanism 8 using a magnet is incorporated to return the actuator 6 to the standby position and maintain the position.
and an automatic ignition type gas cutting torch in which the electrodes 6A, 6B of the piezoelectric mechanisms 6, 7 and the spark electrodes 4, 5 are electrically connected, and the movable member 7 or 6 is in a standby position. An automatic ignition type gas cutting torch is provided with a pressure relief passage 9 that communicates a flow passage 17 portion upstream near a contact surface with a member 22 that sometimes comes into contact with a flow passage 21 portion downstream of the contact surface.