DD221663A1 - METHOD AND DEVICE FOR WELDING GAS SUPPLY - Google Patents

Abstract

The effectiveness of the inert gas welding in particular should be increased. The task of reducing the gas losses in the phase of work interruptions and the movement of the welding impulse, in particular small welded parts is using known pressure regulating, flow measuring and welding devices solved by the fact that the welding gas provided in a defined flow rate, then the working pressure pue to an intermediate pressure pz corresponding to pue pz 5 ... 20 and then slightly again to the flow counterpressure pg of the welding device corresponding to pz pg 1.05 ... 1.2 is released and that with an increase of pg to an adjustable maximum pressure level pg max. pz 1.05 pzthis flow backpressure pg is disproportionately increased in pressure to pz. Devices for practicing the inventive method reveal a surprisingly simple and secure solution by a new, opposite to the previous design teachings design and design principle for inert gas pressure reducer, in particular multi-stage design.

Description

Method and device for welding gas supply Field of application of the invention

The invention relates to a method and an associated device for supplying preferably with welding gases.

Characteristic of the known technical solution It is known that a number of welding machines, such as

z. B. Autogen burner are to be supplied with constant gas pressures are '''''.'.' . ·. '"".'- · The variable quantitative dosage of oxyacetylene welding gases either via valves or pressure nozzles certain size. For this purpose, the gases are taken from compressed gas cylinders or loops, with a cylinder or ring line pressure reducer attached to the extraction point. These devices are often referred to as pressure regulator. It is common to have such pressure regulators successively. Coupled to use or so-called multi-stage pressure reducer

to be used, especially on pressurized gas cylinders for high-tension gases.

Furthermore, it is known that the other gas welding devices are to be supplied with constant amounts of gas. In these devices, it does not depend on large Druckkpnstanz in the gas supply lines leading to the welder, but on a constant quantity in the gas flow through the entire welding machine. For this purpose, adjustable cylinder or ring line pressure reducers are equipped at their output with a variable area flowmeter (rotameter) or a metering nozzle.

According to DD-PS 142 919 has been proposed to increase the accuracy of the gas pressure in the rotameter at the output of the pressure reducer in a defined manner in relation to the flow back pressure of the downstream consumer and keep constant. Furthermore, DD-PS 206047 has been proposed to classify a metering nozzle at the outlet of a protective gas pressure reducer known per se as a gas cutting nozzle.

The disadvantage of all known pressure reducers and welding gas supply devices equipped with flow meters (rotameters, metering nozzles) is the relatively high gas losses in the phase of work stoppages (ie interruption of gas flow) and the need for small and medium welded parts to be blown off "must be secured by '" the welding gas flow.

Object of the invention

It is an object of the invention to increase the effectiveness of inert gas welding equipment in particular.

The essence of the invention

The object of the invention is to provide a method and associated facilities for the supply of welding gas.

Winding, rait where the losses of welding gases in the phases of work interruptions and the movement impulse of the welding gas can be significantly reduced to the weld parts, so that small and light weld parts need not be secured. Erfindungsgeraäß the object has been achieved in that using known per se Druckregel-, Druckflußmeß- and welding devices, the inert gas is first provided with a variable or constant working pressure p .. in a defined flow rate, then that this flow rate to an intermediate pressure ρ corresponding

'':. " - ^: - ~. i & . -5 -... 20 .. .. /,.

and then again from the intermediate pressure p, to the flow back pressure ρ of the welding device, but only slightly corresponding

--2-, j? - 1.05 ... 1.2

is relaxed, and that with increasing ρ to an adjustable maximum pressure level

Pg max>? - <ρ

I 1.05 ^z

this flow back pressure is supercharged to ρ in a proportional manner, until ρ = p .., where p .., ρ, ρ and ρ, overpressure is designated. ^r z ^r g ^ g max. when

A device for carrying out the encryption according to the invention, driving is designed in a surprisingly simple manner in that it comprises at least a first conventional per se membrane pressure reducer level, at the working pressure output, designed for operating pressures -p ..- to vorzügsv; else 10 kp / cm, a Float flowmeter with a downstream throttle valve or orifice plate preferably with

an upstream pressure gauge whose pressure is

     '2' '' '' '

selzirkschnitt A-. in mm accordingly

'' - 'δ''<V max . ^; . ^;

in which V is the maximum flow rate of the welding gas in m / h, p .. the maximum working pressure in

2 u max

kp / cm overpressure and K are a gas-dependent factor, with

K? » 0.3 For ^H 2 NH ₃ K ^ 0.5 For He vl _2> air, CO, K ^ 1 For CH ₄ . :O... K J ^, 1.2 For O, r K «^ 1.5 For Ar, K. ft * 1.8 For ^G 3 ^H 8

and that in the flow direction behind the throttle cross-section A, a second pressure reducing stage is arranged, which in contrast to the previous design and operating theory to a closing dumper ρ ^ 2 p_ "is fixed,

where ρ is the maximum flow back pressure (at V) g max max

g is the downstream welding device, and in which the St röinungsquerschnitt A between the housing and sealing cone is smaller than the full opening cross-section between the sealing cone and sealing seat, measured according to

Λ> ^{1OI <} · ^V max.

The erfindungsgeroäße device is preferably designed so that the two pressure reducer stages are mounted with the interposed floating body flow meter with nachgeordnetera throttle valve or with the orifice arranged therebetween with upstream pressure gauge in a common housing. In a further preferred embodiment, the device according to the invention is composed only of the two printing

constructed with an in-between throttle valve or orifice plate so that there is no flow rate detection element inside it and additionally equipped with a simple atmospheric pressure calibrated flow rate meter preferably according to the float principle which has a resilient sealing cone connection for application to the welding nozzle is. . ": ·. '.' \ /. ^X

The advantages of the invention are that in a simple manner and with simple means and maintenance-free and with the highest reliability of occurring in the phase of work interruptions pressure increase in the supply line and in the welding torch is kept at reproducible and easily adjustable minimum level, whereby the previously existing Gas losses are reduced when switching on the welding process as a result of the rapid reduction of the pressure increase to a negligible degree and at the same time thereby the previously existing "blowing away" even very small small welded parts is avoided. The device reproducing the method according to the invention derives its particular high reliability from a novel design principle, which in addition to the design of the throttle cross-section A, and the pressure values of p ₈ and ρ in particular based on the fact that the flow cross-section between the housing and sealing cone basically in a defined size smaller than that Opening cross-section between the sealing cone and sealing seat is "By this, the previous design rules for pressure reducer contradictory execution is a previously unknown functional effect available" This is that the sealing cone due to the pressure-wise design of the process and the special design of the flow cross-sections, in particular the Ströiaungsquerschnitts between housing and sealing cone, which receives the functional effect of a flow resistance which can be moved in a gas flow and which is dependent on the flow dynamics and instantaneous position of the flow resistance.

amount and the pressures ρ and ρ on the one hand is affected

' · Ζ g ··,. ·.

and, on the other hand, it is self-feedback-responsive to these variables. From this, the disproportionate pressure increase, which has been realized in a simple manner from ρ when the value of ρ is increased to the maximum pressure level ρ _ _x , has also been realized. The designed as a movable flow resistance sealing cone acts; This means that the maximum flow rate can not be significantly exceeded, because with increasing flow rate of the movable flow resistance through flow envelope and not least also increased flow force is printed against the sealing seats and thus the flow area for the shielding gas quickly reduces or closes.

embodiment

The invention will be explained below in an embodiment near.

The accompanying drawing shows schematically in section an executed as a combined pressure and flow control valve inventive device.

The device is connected by means of connecting piece 1 and union nut 2 to an argon gas cylinder, not shown. In the housing 3 is a first per se conventional Diaphragm Druckraindererstufe, consisting essentially of closing spring 4, sealing cone 5, sealing seat 6, diaphragm 7, spring 8, screw 9 and screw 10. The bottle pressure of this first diaphragm pressure reducing stage is screwed tight with the housing 3 in the tight Bottle pressure gauge 11 checked.

With the adjusting screw 9, the working pressure p .. is set in the range up to 10 kp / cm. The working pressure p .. can be controlled with the screwed also in the housing 3 pressure gauge 12. In the working pressure outlet 13 of the first diaphragm pressure reducing stage, an orifice plate 14 is tightly inserted.

screwed. The throttle cross-section A _{Q of} the orifice 14 is in inventive design for a maximum

Flow rate of 1.2 m / h around 0.25 mm. In contrast to the previously known pressure reducer designs, a second fixed pressure reducing stage is arranged in the same housing 3 in the flow direction behind the first controllable diaphragm pressure reducing stage, which essentially consists of closing spring 15, sealing cone 16, sealing seat 17, diaphragm 18, adjusting spring 19, adjusting screw 20, locking nut 21 and screw cap 12 is made. For a flow rate of ζ »Θ» 0.6 m / h, a working pressure p _ü «2.3 kp / cm is set by means of adjusting screw 9, which, as it flows through the throttle cross-section Ä dosing in the flow restrictor 14, to an intermediate pressure

M ο '' '' ρ = 0.3 kp / cm relaxed and then forwarded to the second pressure reducer stage, in particular ^ past the closing spring 1.5 and the sealing cone 16. The flow cross section A between the housing 3 and sealing cone 16 is with

  '- · "Sp. ...".

As a result of the fact that now the critical flow cross-section for the welding gas under the intermediate pressure p_ consists of argon between the housing 3 and the movable, also oscillating sealing cone 16, the flow rate increases as the flow rate increases Flow force on the sealing cone 16 is first gradually increased without changing the critical flow area. Approaching the maximum flow rate V is a

ΓΠ3Χ

turbulent flow envelope in the critical flow cross-section, whereby the Ströraungskraft on the sealing cone 16 abruptly increases and the sealing cone 16 presses against the sealing seat 17, which in addition to the pressure increase of ρ

in the direction of ρ "to a disproportionate pressure level max

back from p_ and leads to an automatic limitation to the maximum flow rate V. The second

Max

Pressure reducer stage is by means of screw 20, locking nut 21, spring 19 and diaphragm 18 to a maximum

'. '·. ^; , ·. '"-''' ⁸ '-' .-.

 '· 2' · '("

Pressure level ρ _β «0.5 kp / cm of the flow back pressure

y Πι3λ. ,

ρ of the ara outlet connection 23 by means of burner hose 24

closed and not shown welding torch limited mention is still i that the sealing cone 5 and 16 by means of lifters 25 with the membranes 7 and 18 in conjunction «The sealing cone 5 and 16 and closing springs 4 and 15 are above the screw plugs 26 in the housing 3 a ·

If the gas flow to the welding torch is blocked off by means of a conventional valve and the burner tube 24, not shown, the sealing seat 17 is also closed by the sealing cone 16 when ρ _mov = 0.5 kp / cm is reached ,

Thus' can in burner tube 24 no higher pressure than

ρ β 0.5 kp / cra occur. Thus, on the one hand g max, 3

60 m of argon are saved each year if the burner hose has a nominal diameter of 9 mm and a length of 3 m, and on the other hand a "blow-off" is not very small and welds are weaker due to the now extremely low back pressure (p '= 0.5 kg / cm) to watch more.

Claims (4)

invention claims ~ £ ~ # 1.05 _e .. 1,2 ; ; -. , ^p q. · ^: · - ^: ;. ' -.-. . is relaxed, and that with increasing ρ to an adjustable maximum pressure level ρ
9 this back pressure ρ is returned to p ₂ at a disproportionately higher pressure until p ₂ »p .. is reached, where p .., ρ, ρ and ρ are used as top pressures. u g g max are drawn. 1. A method for welding gas supply using pressure control, Durchflußmeß- and welding devices known per se, with which the welding gas is provided in a defined flow rate, characterized in that the welding gas from the working pressure p .. to an intermediate pressure ρ accordingly  - £ - ÄS 5 ... 20 and then again from Zwichendruok ρ on the flow back pressure ρ of the welding device, but only slightly corresponding ^ '2' whose throttle cross-sections A in mm accordingly A _K £ κ .. - max +1 in which V _1n ^ _v the maximum flow rate m max? in m / h., p .. the maximum working pressure in kp / cm overpressure and K are a gas-related factor, with ^ K Äi 1,8 for C_H _O 5 8 and that in the flow direction behind the throttle cross section, a second pressure reducing stage is arranged, which corresponds to a closing pressure ρ pi 2p
, s ^r g max,> where ρ is the maximum flow rate max pressure (at V) of the nachgemax arranged welding device, is fixed and in the flow cross section A _e between the housing (3) and sealing cone (16) accordingly ^A s> ¹⁰ · ^K / ^V max · However, smaller than the full opening cross-section between the sealing cone (16) and sealing seat (17). ; '. · · · · ·. _: . · N ·. - 2, means for performing a method according to I _1, characterized in that it comprises at least one first conventional diaphragm pressure reducing stage, at the working pressure outlet (13). designed for working pressures p "to preferably at most 10 kp / cm, a variable area flowmeter with downstream throttle valve or an orifice (14) preferably with an upstream pressure gauge (12) is arranged, 3 ". Device according to 1 and 2, characterized in that the two pressure reducer stages with the arranged therebetween floating body flow meter with downstream throttle valve or with the interposed Qoöselblende (14) with upstream pressure gauge (12) in a common housing (3) are installed. 4. Device according to 1 to 3, characterized in that it is composed essentially only of the two pressure reducing valve with an interposed throttle valve or orifice plate (14) and that it is completed with an additional, but separate, calibrated to atmospheric pressure, Float flow meter , Which has at its lower end a plastic-elastic sealing cone for vertical attachment to the welding nozzle. to 1