JPS5824686B2 - welding torch - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a welding flame lamp useful for heating or welding metals.

In our Australian Patent No. 460066, we described and claimed a welding torch attachment for attachment to the bend of the handle 9 of a welding torch.

The appendage includes a mixing chamber extending downstream from the guide tube and terminating in a nozzle; the mixing chamber has a reed at least eight times its diameter, and the chamber and nozzle walls do not include abrupt steps. The gas passing through it formed a substantially undisturbed streamline.

The welding torch attachment disclosed therein had the property of providing a more concentrated and hotter thermal profile than previously proposed welding torches.

This property has made it economical to use gas.

An independent test carried out by Azoraid University showed that the overall gas savings were around 80%.

However, certain difficulties were encountered with this welding torch.

The most significant of these difficulties has been the cumbersome grip and the relatively long mixing chamber that makes it difficult to use when attached to existing welding torches.

One object of the present invention is to provide an improvement that achieves a higher, more intensive heat profile than common existing welding torches, yet has a much more stylish and convenient grip.

The closest prior art known to the applicant is Fou
In U.S. Pat. 1. Safety requirements have a large influence on the shape of welding torches.

"Blowback" is a phenomenon caused by the forward moving flame returning through the nozzle opening and into the mixing chamber of the welding torch.

Welding torches, such as those currently in use, require more oxygen than acetylene.

(In order to satisfy the combustion equation 502+2C2H224CO2+2H20), it is common to use oxygen at a higher pressure than acetylene.

For oxygen it is now possible to charge an acetylene hose, and to reduce the risk of blowbanking, acetylene is introduced into the mixing chamber of prior art welding torches through several small openings. .

However, "blowback" can cause small explosions within the mixing chamber, and despite the presence of small openings, there have still been instances of explosions damaging acetylene pressure gauges due to combustion within the acetylene hose itself. There is.

Up to the hole (acetylene hose) K that carries flammable gas.
It is another object of the present invention to improve the safety of welding torches so that there is less concern about extended blowback.

Briefly, the present invention provides a welding torch having a first mixing chamber of relatively small volume, a second mixing chamber of relatively large volume, a hole for guiding a gas mixture that is much larger in length than diameter, and a first mixing chamber of relatively small volume. It includes components that define a guide hole for guiding the gas mixed in the mixing chamber to the second mixing chamber, a discharge nozzle at the downstream end of the second mixing chamber, and the like.

If the chamber, guide hole and nozzle are coaxial, and if they are dimensioned accurately, it is possible to use equal pressures for oxygen and acetylene;
This reduces the risk of oxygen entering the acetylene hose.

It has also been found that it is possible to achieve more concentrated heat at higher temperatures than that achieved with the welding torch described in the '066 patent.

If the welding torch directs a central stream of oxygen into the first mixing chamber, which flows into the annularly flowing ring of acetylene, the additional oxygen required and supplied from the atmosphere is added to the acetylene from the nozzle. Enriched tubes are flown in by smoothly flowing undisturbed gas flowing out into the tube.

Furthermore, the gas surrounding the weld zone contains water vapor, nitrogen and carbon dioxide, so that corrosion near the weld zone is largely inhibited.

Furthermore, a phenomenon was observed in which the center of the flame was hotter than in prior art welding torches, which is believed to be due to non-uniform combustion over the cross section of the flame.

More particularly, the present invention provides a grip portion and an oxygen conduit within the grip portion having a coupling device at its upstream end for connecting to an oxygen supply hose, and in gas flow communication with said conduit at its downstream end. combustible in a gripping part having a tubular oxygen director and a small mixing element, a first mixing chamber, and a coupling device for connecting the oxygen director to a flammable gas supply hose at its upstream end; a gas conduit and a wall within the handle portion that brings the downstream end of the gas conduit into gas flow communication with the first mixing chamber, and a hole and a hole having a length exceeding the diameter and for directing a gas mixture of a length exceeding the diameter thereof; a gas mixing structure including a wall defining a second mixing chamber of larger volume than the first mixing chamber with a diameter exceeding the diameter of the gas mixture guiding hole; and a discharge nozzle at the downstream end of the second mixing chamber. The oxygen director, the first mixing chamber, the gas mixture guiding hole, the second mixing chamber and the nozzle all have a common polar axis.

For this arrangement, oxygen and gas flowing out of the nozzle.

The flow of acetylene and acetylene (as an example) provides a very smooth flame with a highly concentrated hot center even though less oxygen is used than in a typical welding torch.

This welding torch is covered by the Australian Patent No. 4600.
It is possible to achieve faster welding speeds (for the same gas consumption) than the composite welding torch and attachment described in '66.

For complete combustion, the ratio of oxygen to acetylene should be 1 = 1 part by weight (other oxygen should be (coming from the atmosphere) and can further reduce gas usage.

Some workers use the welding torch with their right hand, others with their left hand.

In another aspect of the invention, the handle part of the welding torch has a swivel nut at the upstream end of each of the oxygen conduit and the gas conduit, a valve connected to the swivel nut, and a valve on the inlet end of the respective valve. Equipped with hose joint pipe.

By loosening the swivel nut, the valve is rotated and moved to a position suitable for the user.

In another embodiment of the invention, the grip portion includes a handle through which the oxygen conduit and the gas conduit pass.

In another aspect of the invention, the gripping part has a connecting block fixed to it and having a gas flow conduit extending through the block, said connecting block being such that the gripping part can be used as a "pencil welding torch". It has a relatively small size.

In the first embodiment of FIGS. 1, 2, 3 and 4, the welding torch 10 has a grip portion 11, and the “end portion” of the grip portion 9 has two joint tubes, each designated 12. established,
Each has a swivel nut to which is connected a respective valve, one designated at 13 for oxygen and the other at 14 for combustible gas.

(The term "gas" used here is usually thought to mean acetylene, but in the present invention, butane,
(Other gases can also be used) The arrangement of the swivel nut allows the joint to occupy the most convenient position for the user, and this means that the arrangement allows the hand-held welding torch to be used by right-handed or left-handed workers. This is an extremely desirable feature.

In this embodiment, the grip portion 11 is constructed to be conveniently held in the hand of the operator and terminates in a projection 17 at the end remote from the nut-joint tube.

The projection is provided with a threaded hole 18 extending through it at an angle with respect to the longitudinal axis of the handle of the grip part, and the grip part incorporates two conduits, one of which is an oxygen conduit 19 at the rear end;
The other is a gas conduit 20 at the front end which terminates in parallel or nearly parallel threaded holes 18.

Oxygen conduit 19 is behind gas conduit 20.

Although the conduit may be formed by a hole drilled into another form of solid handle, a "lightweight" handle, as illustrated, is typically preferred by operators.

The threaded hole is first screwed into engagement by an oxygen director 24, said oxygen director being a threaded member having a thread 25 extending along its length, the thread 25 itself being in an annular recess 26.
is blocked by a wall that forms a

The front end or downstream end of the oxygen director has a pipe shaft 27;
The shaft tapers along its outer circumference and surrounds a central axially extending oxygen guiding hole 28.

The crest hole 28 is of a diameter approximately equal to the largest diameter nozzle used, which in this embodiment is 2.40 mm in diameter.

The plurality of radially extending holes 29 are oxygen guiding holes 2.
8 opens into an annular recess 26 across the rear end of the annular recess 26, this arrangement ensures that when the oxygen inductor is screwed into position, i.e. at the base of the threaded hole 18 in the projection 17 of the handle part, the annular recess 26 is in line with the oxygen conduit, and the oxygen
The annular recess is routed through radial holes to the oxygen induction holes, from where it exits as a relatively small diameter, high-velocity stream.

Close to the mouth or downstream end of the threaded hole in the grip portion protrusion 17 (
, there is a gas mixing structure, generally designated 31, with a first
A mixing member 32 is provided.

This first mixing member 32 has a gas diffusion skirt 33 at its upstream end, which skirt surrounds the tapered pipe shaft 27;
Shoulder 3 at the upstream end of the tapered pipe shaft 27 at its upstream end
4, the gas diffusion skirt has at its upstream end a relatively large diameter central chamber, which constitutes a first mixing chamber 35, into which a small diameter flow of oxygen is communicated.

A plurality of small diameter radially extending holes 37 pass through the gas diffusion skirt, and the arrangement is similar to that of the gas diffusion skirt (
A space surrounding the gas conduit 20, the outer diameter of which is smaller than the thread diameter of the threaded hole, communicates with the downstream end of the gas conduit 20, such that the gas pressure and oxygen flow within the gas conduit directs the gas to the outer circumference of the oxygen stream. Combine them so that they flow into nearby areas.

The first mixing chamber thus contains some mixture of gas and oxygen, although the flow through it is relatively undisturbed, but even at this stage the center is at least oxygen-rich. It is believed that

This is in direct contrast to prior art welding torches, many of which used complex arrangements to obtain a sufficiently turbulent flow of gas.

As best seen in FIG. 3, radially extending holes 37 open into a dividing annular space.

In the event of a "blow back", the risk of combustion within the acetylene hose is reduced by this configuration, even if oxygen enters the acetylene hose.

The first mixing member 32 has only at its upstream end a first mixing chamber 35 of relatively large diameter, which has a gas mixture guiding hole 39
It communicates with a hole surrounded by parallel walls of relatively small diameter, which can be considered as a hole.

In this embodiment, the gas mixture conducting holes are 2.40 millimeters in diameter so that the gas mixture exiting therefrom exits as a relatively unturbulent flow of relatively small diameter.

However, its length is at least five times greater than its diameter, which in this embodiment is about 22 millimeters.

This dimension is important and must be adjusted by empirical means for any welding torch of a given dimension to achieve optimal results.

A threaded outer portion of the first mixing member 32 projects outwardly from the mouth of the handle and is threadedly engaged by a small sleeve 41 constituting an air inlet sleeve, which is threaded throughout its entire length. , having a plurality of radially extending holes extending from and through shallow grooves 42 in its outer surface.

The holes include three relatively large holes 43 and three relatively small holes 44, and this arrangement limits the extent of "blowback" effects more than if all the holes were of the same size. It is more suitable for

The reason is that it creates a non-uniform gas mixture within the welding torch.

The radially extending holes 43 and 44 are located slightly downstream of the downstream end of the first mixing member 32, which has a small protruding protrusion 4 that tapers towards the outlet end.
6, which when said hole is opened for the gas flow exiting the first mixing member, air is admitted into the gas flow as shown in FIG.

The other or downstream end of air mixing sleeve 41 is threadedly engaged by a second mixing member 48 of gas mixing structure 31, which second mixing member 48 has a thread extending over most, but not all, of its length. The screw has a recess 49 which interrupts its end in the middle when the second mixing member is unscrewed to fully expose the air inlet holes 43 and 44 (as can be seen). are doing.

Air inlet holes are only occasionally exposed.

It is clear from welding metals that when a welding torch is required for heating the metal, a large portion of the relatively cold gas is required to exit from the nozzle.

Typically, however, the second mixing member surrounds the protrusion 46 at the downstream end of the first mixing member (screws close to the tapered surface 46') and is threaded through a relatively large diameter central hole 52 in the member 48.
A second mixing chamber is formed as indicated by .

The nozzle 53 is screwed to the downstream end of the second mixing member 48.
The nozzle 53 has a perforation 54 with the same diameter as the second mixing chamber 52, and the perforation has a nozzle or outlet nozzle 5.
It terminates in a tapered wall 55 terminating at 6.

The perforation 55 of the nozzle 53, the inner wall of the injection hole 56, and the perforation of the second mixing chamber 52 are made as smooth as possible, and the smoother the better.

In this embodiment, the walls of the perforations in the second mixing chamber 52 are ground to a high degree of smoothness.

It has also been discovered that the length of the perforation common to the second mixing chamber and the upstream end of the nozzle should be related to its diameter if the perforation is very long.

However, for practical purposes, it is desirable that the perforations be as short as possible, and with a diameter greater than eight times the perforation diameter.

In this embodiment, the drill hole length is 11.25 x drill diameter, which is 6.4 mm for a drill diameter of approximately 7 mm.
It is required to be 2 mw.

It has been found through experimentation that the hole length should be an odd multiple of 1.25X diameter, and less than 8.75X diameter to achieve the desired mixing conditions.

If the perforation increases beyond the 11.25x diameter of this embodiment, the improvement will often be so slight that the increased length is not required, but the length limit will gradually decrease. will be progressively improved.

It has also been discovered that it is desirable to control the convergence angle of the tapered wall 55 defining the end of the perforation of the second mixing chamber; in this embodiment, the included cone angle is approximately 54 degrees.

Then it should be between 45 and 65, or 54
The closer it is taken to , the better the result will probably be (4).

This is believed to be related to the deflection of gas particles or molecules from the walls of the perforation.

Also, for reasons that are not clear, the diameter of the nozzle exit hole is critical, and a series of experiments are required to confirm that the diameter is appropriate for a given welding torch. was discovered.

In this example embodiment, three satisfactory diameters were found.

The first is 0.90 mm, the second is 1.30 mm, and the largest is 2.40 mm, which is the same diameter as the diameter of the hole through the oxygen director and the first mixing member. be.

It has been discovered that holes having diameters of other values between these diameter values give inferior results.

In use, low pressure gases (approximately 4 P, S, i or 28 P, a) are delivered to the flare lamp in equal amounts and not in the theoretically correct 80:32 ratio of oxygen to acetylene. Flame temperatures are extremely high for extremely small diameters.

The blue smooth cylindrical flame extends approximately 1911 tm for the smallest tip, 29 trtw for the medium tip, and 16 tm for the large tip.

It has been found that if butane and oxygen are used, a 1-1 volume ratio is used and satisfactory processing is obtained, but at much lower temperatures than with acetylene.

It is known that the first combustion of the blue conical flame produces carbon monoxide and hydrogen, and the second combustion of the surrounding flame produces carbon dioxide and water vapor.

However, the surrounding flame is not rich in oxygen, and the oxygen is mixed from the atmosphere by the smooth inlet gas, forming an surrounding flame.

The amount of oxygen introduced is much greater than that associated with prior art welding torches, and welding is carried out under favorable conditions such that metal oxidation is negligible.

This in turn simplifies welding of difficult metals such as aluminum and magnesium alloys.

The present invention results in improvements such that microwelding is possible, and the second
In the embodiment (shown in Figure 5), the construction is substantially similar to the first one, with like numerals indicating like components, the only difference being that as in the first case the handle Instead of using a handle part 11, the handle part 11 is provided with a gas guiding block fixed on one side and near one end of a mounting cylinder 61, which cylinder replaces the protrusion of the handle and which includes an oxygen director and a first mixing member. are screwed together.

Block 60 includes two small flexible tubes 62 to hose valves (not shown), and the device can be held between the fingers like a pencil.

However, if necessary, a simple tubular handle 63 is also provided which slides over the device and secures to the cylindrical member 61 to provide a handle for hand welding.

[Brief explanation of the drawing]

1 is a partially sectional side view of a welding torch according to a first aspect of the invention; FIG. 2 is an "exploded" side view of the oxygen director, gas mixing structure and nozzle; and FIG. 3 is the assembled components. FIG. 4 is a fragmented cross-sectional side view showing two mixing members of the gas mixing structure separated to allow air to flow into the second mixing chamber; FIG. FIG. 3 is a side view of a “pencil-shaped torch” according to the embodiment. In these drawings, 10 is a welding torch, 11 is a grip portion, 12 is a joining pipe, 13 is an oxygen valve, 14 is a flammable gas valve, 17 is a protrusion, 18 is a threaded hole, 19 is an oxygen conduit, and 20 24 is a gas conduit, 24 is an oxygen guide, 26 is an annular recess, 27 is a tapered pipe shaft, 28 is an oxygen guide hole, 29 is a hole extending in the radial direction, 31 is a first mixing structure, 32 is a first
Mixing member, 33 is a gas diffusion skirt, 35 is a first gas mixing chamber, 37 is a radially extending hole, 39 is a gas mixture guide hole, 41 is a sleeve, 42 is a shallow groove, 43°44 is an air inlet hole, 48 52 is a second mixing member, 52 is a second mixing chamber,
53 is a nozzle, 55 is a perforation, 56 is an injection hole, 60 is a gas guide block, 61 is a mounting cylinder, and 62 is a flexible tube.

Claims (1)

[Scope of Claims] 1. An oxygen guide having a tubular oxygen guide hole with the same diameter inside, forming an oxygen supply conduit communication part at one end, and having a tapered stem at the other end; a tubular hole having a large diameter and a suitable length, and a small diameter gas mixture guiding hole communicating with the large diameter hole on the downstream side thereof, and extending radially at a suitable location on the upstream wall. A plurality of small holes are formed to form a combustible gas supply conduit communication section communicating with the large hole, and a protrusion having a tapered part is formed at the downstream end, and the oxygen guide is provided in the direction of the large diameter. A second tapered stem is attached to form an annular space for inflowing flammable gas that is continuous with the small hole between the outside of the tapered part and the inner wall of the hole, and between the end of the tapered stem and the upstream end of the gas mixture guiding hole. a first mixing member that forms a first mixing chamber; a second mixing chamber that has a tubular shape and has the same diameter; A protrusion at the downstream end of the first mixing member is inserted into the upstream side of the mixing member, and an annular gap for air inflow can be adjusted between the tapered part on the upstream side and the tapered part on the downstream side of the first mixing member. a second mixing member formed with four parts in the longitudinal direction on the upstream side thereof, and a longitudinal hole communicating with the recessed part, a tapered hole continuous to the downstream end of the crest hole, and an injection port continuous with the tapered hole. and a nozzle for mounting the downstream end of the second mixing member in the recess, and a plurality of annular holes bored in the wall in the radial direction, and a plurality of annular holes formed in the wall between the first mixing member and the second mixing member. an air inflow sleeve that is attached to the outside, adjustably connects the two members, and adjusts the amount of air inflow by aligning the hole with the annular gap for air inflow formed between the ends of the two members; and a grip flat portion attached to an appropriate location on the rear of the main body, an oxygen supply conduit is adjustably joined to the oxygen supply conduit communication part, and a combustible gas supply conduit is connected to the combustible gas supply conduit communication part. A welding torch, wherein the welding torch is adjustable and is configured such that the holes provided in the longitudinal direction of the main body are all aligned on the same axis. 2. A welding torch according to claim 1, wherein the walls of the gas mixture guiding holes are parallel and the length of the walls of the hole is at least five times greater than the diameter of the hole. 3. The welding torch according to claim 1 or 2, wherein the downstream end of the hole in the oxygen director is separated from the upstream end of the hole through which the gas mixture is guided by the first mixing chamber. 4. The welding torch according to any one of claims 1 to 3, wherein the second mixing chamber has a length exceeding eight times its diameter. 5 said gripping 9 portion is provided with a threaded hole, and each of said tubular oxygen directors, first and second mixing members have external threads, and said oxygen director and first mixing member are screwed into said holes; 5. A welding torch according to claim 4, wherein the threaded sleeve threadably engages the protruding end of the mixing member to connect it to the upstream end of the second mixing member. . 6 The oxygen conduit and the gas conduit include a husband and wife swivel nut on their mounting ends, respective valves connected to said swivel nuts, and a hose junction on their respective inlet ends. A welding torch according to any one of items 1 to 5. 1. The welding torch according to any one of claims 1 to 6, wherein the grip portion further includes a handle, and both the oxygen conduit and the gas conduit are built into the handle. 8 wherein said gripping portion comprises a mounting cylinder, said mounting comprising a block fixed on one side of the cylinder near one end thereof, said block containing said conduit, and said gas mixing structure comprising said mounting cylinder; is coaxial with the cylinder,
The welding torch according to claim 1, wherein the welding torch is supported so as to protrude from the other end. 9. The welding torch of claim 8, wherein the handle is removably engageable on the block and the mounting on the cylinder.