DE8337771U1 - Device for controlling the welding of a seam - Google Patents

Description

-δι M.A.N. MASCHINENFABRIK AUGSBURG-NÜRNBERG Corporation

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Munich, December 22, 1983 10

Device for controlling the welding of a seam

The invention relates to a device according to the Preamble of claim 1.

In the case of the article "Automatic regulation of the

brands in arc welding "» trade journal "Swarotschnoje Proiswodstwo" (welding production), pages 23 to 25 »No. 8, 1961« USSR ₁ known device of this type, the binding is automatically regulated or an unchangeable depth of the penetration with a changing size of the seam gap between the welding edges * The penetration is kept stable due to the control of a pendulum width of an electrode. It is a system of automatic control of the pendulum width of the electrode depending on the depth of the penetration of the root of the weld Arranged a crystalline photoelectric diode »First the required

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Melting through the root ensures what the previous one specified intensity of the light emission and the infrared emission of the arc «on the above FUhIer acts, corresponds, and with a decrease and / or amplification of the melting through reduce or increase the intensity of the light of the arc and the electrical resistance of the said diode and, depending on this, will again be the required melting of the shock. All of this takes place via many parts of the control system. These are all electrical type. The device is at two end faces applied to pipes to be welded. So that the sensor is not soiled by molten metal, Is it placed to the side of the joint. It is aligned towards the root · sehmeizfieek. It can be arranged roughly centrally be. When welding the circumferential seam, disadvantageously, it must be rotated with the moving root melt spot will. A device having the sensor is arranged in one of the tubes, in which the sensor is off-center is what makes this device disadvantageously more complicated and expensive because the sensor rotated must be and also must always be aligned towards the root melting point when turning. A large The disadvantage is that the sensor adjusts with respect to the joint, i. H. must be precisely defined.

It is the object of the invention to ensure that the sensor does not adjust or is not precisely defined with respect to the root or has to be arranged and even laterally rela-

tiv can be far away.

According to the invention, this object is achieved by the identifier of claim 1 solved.

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The welding is regulated as a function of the light that is emitted by the root and received by the said light diffuser and passed on to the sensor will. From the root, from the ight diffuser collected b2w. light that has penetrated into him becomes in 1hm homogeneously spread, d. H. scattered in all directions. Its entire volume becomes with maximum intensity fully illuminated. Every point in 1hm acts as a Light source. The sensor takes the 1m generated light diffuser Light radiation from these light sources. It is diffuse light, i.e. scattered light without an orderly course of rays. 2. 6. Light falls from the root of a straight weld through a plate-shaped said light diffuser onto the sensor, the sensor may next to the

! 5 containing the root, perpendicular to the light diffuser Level arranged, moved or moved, because through this light diffuser one without it does not become desirable oblique incidence of light on the sensor avoided and achieved an impingement of diffuse light on the sensor. Thanks to the light diffuser, a pronounced Radiation direction change of the light can be achieved. So then the sensor, if he z. B. because of the Heat not against the root and / or z. B. not compared to one next to this on one of the to be welded Components, e.g. B. Pipes, located bar or panel arranged can be laterally or axially removed from the welding plane, also relatively far away, z. B. in the light shadow the aperture. The light diffuser can diffuse light in all directions, e.g. B. not

only in the direction further away from the root, but also opposite to the middle stabilization device of the light Diverted from the root to the light diffuser by, for example, 50 ° or 90 °, emit to the sensor. An adjustment or precise setting, definition or arrangement of the

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Sensor and also the light diffuser, which is perpendicular to the welding plane generally much wider than the weld seam or the root 1st, 1st is not necessary. The Liahtdiffuser can often be carried out with relatively little construction effort.

β The light diffuser can, for. B. a cylindrical and / or have a squat shape.

Formations and developments of the invention or according to the invention Establishments are in the subclaims specified.

The root-at-the-root arrangement according to claim 1 can easily be carried out due to the root-at-a-time free space. An undisturbed and concentrated light radiation from the root to the light diffuser and on to the sensor is also possible there. This contributes to the accuracy of the light intensity measurement by the sensor and the control of the welding of the seam. In order to transmit or capture as many light beams as possible coming from the root to the sensor and / or pass them on to the sensor, the procedure is preferably according to claim 3. A light measuring device according to claim 4 is generally easy to handle. It can often be made robust and with relatively little construction effort. It can be easily installed in pipes to be welded. With the appropriate construction methods, it can also be used with relatively small pipe cross-sections and with curved pipes. When proceeding and arranging according to claim 5, light penetrates the root or the migrating root melting point or the migrating hottest point of the root

ring-shaped welding seam (Rimdnalrt) radial and conical, in the case of claim 6 past the shield mentioned there, into the light diffuser, in order to be diffuse Light from the light diffuser to reach the sensor axially.

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With the or the opposite of the axial weld seam or
Root width axially relatively wide or long light diffuser
or the light entry surface of the light diffuser needs the
Device not axially adjusted, ie not exactly on
to be placed in a particular axial location; the

The main thing is that the light diffuser is axially on both sides
the joining or welding plane has light entry surface.
In addition, claim 5 has the advantage that the sensor
is not arranged centrally in the joining or welding plane,

where it would have to be rotated when welding the circumferential seam with the moving root melting point and it also for
it would usually be too hot; the light diffuser and the sensor
according to claim 5 are not rotated, but stand | fixed. In order to have a relatively high light intensity on the sensor | obtain, it is recommended in the overall training i measured to claim 5 also in accordance with the claim 3, 7 or 8 {

proceed. The receiving body mentioned in claim 8 )

In addition to mirror surface and light diffuser carriers, carriers f

for the features mentioned in claim 16 devices or means \

be. The development or the optical filter according to '

claim 9 is advantageous because to regulate the \

Welding, the radiation \

intensity is to be used and so now the sensor U

I does not yet receive the radiation from the vicinity of the root enamel spot. Through this filter, a linear waste can be achieved by Lichtwelleniänqen i dependence of the measured signal
will. The filter determines the sensitivity of the measurement <; and the regulation even increased. Said rings without the two in the presence I demanding 10 or in claims 10 and Il

many light rays coming from the root melting point go: past the circumference of the light diffuser, ie only arrives
Part of these rays on the light diffuser. If this
and reflective surfaces are provided as specified in claim 7, then one can use a one-dimensional

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Beam bundling speak, while in the design according to claims 7 and 10 or 11, in the case of the other than the specular Surfaces still, those rings are provided, can be spoken of a two-dimensional beam bundling. Due to the rings and the refraction and reflection on them, more light rays fall on the light diffuser and get there thus more light intensity from the light diffuser into the sensor than without the rings, the refraction and the reflection. The design according to claim 12 is well suited for two-dimensional bundling of rays. The outside diameter of the zyl inder-like <»n light diffuser is in relation to the Inner diameter of the pipes to be welded often relatively small, so that the further development according to the claim 13 is not beneficial. The generally cylinder-like receiving body mentioned there has a larger outer diameter than this light diffuser and is generally longer than its own outside diameter. The said Light guides are generally ordered from longitudinal fibers from GTas, i.e. single light guides. But he can also z. B. an inside

^{2 (5 be a} mirrored tube or, for example, a rod made of transparent material whose refractive index is greater than that of the surrounding medium. According to the claim, it is a structurally simple development with simple attachment of the reflective surfaces from the fluid channel mentioned in claim 15 cools various parts of the light measuring device and is used to keep the light measuring device clean by keeping vapors and particles away by constantly blowing out parts of the light measuring device, including the light entry surface of the light diffuser or the said outer ring. The fluid also flows at the root and serves to avoid oxidation of the root. The fluid is generally inert gas. The reflecting surfaces and / or the rings (see claims 3, 7, 8, 10, 11 and 12) can be referred to as light concentrators.

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The entire volume can be used to produce the light diffuser of the body in question ζ. B. by heat treatment in an optically diffuse or light-scattering state be moved. But it can also z. B. only the surface of the body by roughening, in particular by means of Grinding, put in such a state, which only partially reduces the volume of the light diffuser is illuminated. The material of the light diffuser is generally a material that is heat-resistant and against

Impact and / or thermal stresses as little as possible or

is practically insensitive. The light has to go into the light diffuser or its material can penetrate. The material of the light diffuser is in particular glass. The glass is preferably quartz glass. The material of the optical filter is also, in particular, glass. This is also preferred Quartz glass.

In terms of radiation, it can, in particular in the light measuring device, between the root and the sensor, namely before and / or after the light diffuser, at least one lens or collecting lens or at least one lens system for collecting or to concentrate the rays on the light diffuser and / or the sensor.

The regulation of welding in general or that according to the invention Control device is seen or used in the following context in particular:

The formation of the roots is of particular importance in almost all welded connections. Lie in the root area but with regard to the required melting energy relatively unstable conditions. It occurs more often z. B. not to melt root-sided edges, which is usually the case

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is not allowed. Around non-welded root points too avoid, a root counter-weld is often required. The components to be joined are in a different sequence when welding a first layer, the root seam, for a gap, so that the required penetration is closely observed can be. In the case of welds without additives, on the other hand, the joints should generally meet with as little gaps as possible, with which the risk of unmelted root areas is relatively high. Such mistakes will be

z. B. by different thicknesses of the components, changed Heat dissipation, oxide layers, batch differences or the like. Or fluctuations in the welding current strength, the Welding voltage, the distance between the electrode and the joint or gap, the gas composition or the like. Or at least least caused two of these influences. The root area is particularly sensitive to these influences, because it is furthest away from the place of energy input and often receives too little energy, which is then no longer sufficient to melt the edges.

The root area of the weld seam that is currently melting or the melting spot of the root is recorded the unsteady factors influencing the weld seam quality, where the fluctuations mentioned occur summed up and intensified in appearance. It is the measurement of the light or the strength of the light from the root or the wandering Melting spot or the hottest part of the Root beneficial. The light emission lying between the molten bath that is too large and the edges that are not too molten has a sufficiently resolvable field that can be used for regulation, and the sensor displays spontaneously and lets emissions of largely unrated outside the hottest spot.

36

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l ^<a 'M1t dtn optical signals of the sensor can via a few coupling elements ζ. B, the welding current of a welding device can be regulated or controlled relatively easily and sufficiently quickly to the necessary level, which then produces the desired root melting. The signal provided by the senior is used to regulate or automatically control the welding process. This signal or the height of the same is clearly linked to the thickness of the weld pool and thus the width of the weld pool at the root or of the root melting point, or is dependent on the thickness of this thickness of the joint or on this width. The control device according to the invention is also suitable To regulate the welding current in electron steel welding systems in a very satisfactory manner, with the use of light

lg of the migrating root melting point or with the inventive Control device with the light diffuser that receives this light and also with the control of vision white of the seam 1n depending on the strength of that light emission or of that width, even with fluctuations in the mechanical arc control, such tolerances are the Components that the components with a permanently programmed Welding equipment can no longer be welded, and high quality faults in the welding process Welds achieved. The control device according to the invention is especially for keeping constant, so Regulation that uses the width of the root, namely by adding at least one parameter or characteristic variable from the sensor of the welding or welding process, in particular the welding current or the welding current strength and / or the arc that changes the depth of the skin! ätife and / or the feed rate of the workpiece or of the welding device or torch, controlled accordingly will or will.

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In the drawing, there are four exemplary embodiments in FIGS. 1, 2, 4 and 5 der Regiilungs- b2w. Light measuring device according to of the invention in! two end faces welded to one another Rohnen shown, each 1n a longitudinal section. F1g.3 shows the exemplary embodiment according to F1g, 2 in a cross section ΙΙΙ-ΙΠ.

The following applies to all four exemplary embodiments: This Pipes 10 and 11 are in line. Their outside diameters are the same large, and their inside diameters are the same. Her two corresponding, axially perpendicular end faces form a joint 21. Those there to connect the Tubes 10 and 11 to be produced, coaxial, ring-shaped Weld seam (round seam) 12 has a V-shaped cross-section that decreases radially inward. It is from radial welded on the outside, with a welding torch, not shown. The root or an enamel spot 13 of the same emits light when producing the weld seam 12. The Liehtmeßoinrichtung has a cylinder-like Light diffuser 14 or 38 or 39 and an optical sensor 17, dec centrally at an axial distance from the Joining plane 23 liegii, and is arranged axially so that the Fiigestoß 21 surrounds this light diffuser.

According to FIGS. 1 to 3, the light measuring device, which is to be designated as an optical measuring head, has a fully cylindrical, coaxial arrangement of the light diffuser 14, a fully cylindrical, coaxial receiving body 15 or 29 for it, a light guide 16, the optical sensor 17, a shaft circle Tndstirnflache 18 of Aufnahttefckörefs 15 or 29 to shield the sensor 17 against direct light or rays from the root or the melt spot and a light reflector 18, 19, 20 to increase the light intensity, the light diffuser 14. The light"

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Diffuser 14 is firmly seated with one end in one end of the receiving body 15 or 29. In this end of the light diffuser 14 is a central one! coaxial Blind hole 22 «1n the one end of the light guide 16 radially and is firmly seated axially. This power end is there cemented and ends with an axially centered face 65, which rests against the axis-perpendicular bottom of the blind hole. The putty in question is very translucent. The light guide 16 takes 1m over the end face 55 Light diffuser 14 generated light radiation. The light guide 16 runs centrally through the receiving body 15 or 29 to the sensor 17. The other end of the light diffuser 14 carries a perpendicular "circular, coaxial plate 20" whose outside diameter is significant is larger than the outside diameter of the light diffuser 14. The plate 20 has an axially perpendicular end face on, the end face 18 of the receiving body perpendicular to the axis 15 and an end collar 24 of the same (FIG. 1) or of the receiving body 29. The end collar 24 and the plate 20 have the same outside diameter. The end face 18 and the end face 19 also have this outer diameter and are reflective. They are parallel to each other and reflect light rays according to Fig.l and 2 (See Fig.l, not shown in Fig.2 for the sake of simplicity) of the melting spot 13 to the light diffuser 14. The The outer diameter of the receiving body 15 and 29, the end collar 24 and the plate 20 are smaller than the inner diameter of pipes 10 and 11.

0er optical measuring head or the Aufftahmekörpet * 15 or »29 with the light diffuser 14 and the plate 20 is arranged or fixed in the tubes 10 and 11 coaxially, and although by centering devices, which in Fig.l by

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_χ arrows 26 are indicated and are not shown in Fig.2, and axially arranged or almost laid «d» ß the joining plane 23 approximately in the middle between the two reflective surfaces 18 and 19 b2w. the length of the light diffuser 14 irradiated by the light from the Schmälzflecks 13 Hegt.

The receiving body 15 b2w. 29 has a longitudinally extending, circular ring-shaped cross-section having fluid channel 27 (Fig. 1) or 28 (Fig. 2), 2u which a F1u1daufuhrkana! 53 leads and the sewing according to FIG the light diffuser 14 surrounding space 59 and according to Figure 2 The space 32 surrounding an outer ring 31 opens out. Arrows 50 and 51 indicate the direction of flow of the fluid in F1u1dk * channels 53 and 27 or 28 and arrows 52 the flow devices of the fluid after the outlet from the fluid channel 27 or 28. The fluid cools according to Fig.l and 2 the receiving body 15 or 19, the light guide 16, the light diffuser 14 and the light reflector 18, 19, 20 or this and the outer ring 31 and an inner ring 30, if necessary - see later - a sensor 17 'and a color filter 36. This fluid also flushes particles out of the Establishment and also protects the root from oxidation. After leaving the space 59 or the fluid channel 28 flows the fluid out of the tubes 10 and 11 in opposite axial directions. The receiving body 15 and 29 and the plate 20 are made of a material that conducts heat well, in particular made of metal, e.g. B. steel or aluminum.

The outer ring 31 sits - seventh Fig. 2 and 3 * on an inner ring 30 _t which sits on the light diffuser 14. The outer ring 31 has the same outer diameter as the plate 20 in FIG. These rings 30 and 31 fit snugly

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-ΠΙ between the reflective surfaces 18 and 19 and consist of clear transparent glass. The glass of the outer ring 31 is optically denser than the fluid surrounding the outer ring 31 between it and the tubes 10 and 11 ″ and the glass of the inner ring 30 is optically denser than the glass of the outer ring 31. The (relative) refractive index x \\ for the Transfer from the fluid into the glass of the outer ring 31 b »w. in the outer ring 31 and the (relative) refractive index ng for the transition from this glass or outer ring 31 into the glass of the inner ring 30 or into the inner ring 30 are of the magnitude that refraction and reflection of light rays from the root or the melt spot 13 is carried out to the light diffuser 14 toward - see the three by arrows 33 to 35 indicated light beams curves in Figure 3 -, more light beams that the tubes 10 and compared with the \ 11 relatively small in diameter, light diffuser 14 fall | than without the rings 30 and 31 and thus the light intensity \ of the light diffuser 14 is increased and more light intensity! reaches the sensor 17 from the light diffuser 14. \

*

A somewhat modified design can also be seen from FIG. 1 (this is also possible according to FIG of the sensor 17, an optical sensor 17 * on which the up \

receiving body IS (or 29) located end of the light j

diffuser 14 can be provided on the end face or dash-dotted lines shown - with the interposition of a color filter 36 is provided. A central hole of the receiving body 15 (or 29), through which otherwise the light guide 16 leads, then serves to record electrical, am

Sensor 17 * connected lines, 1

The light diffuser end just mentioned and the sensor 17 'can, in particular with a color provided between them.

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filter 36, plug into an insert that is axially screwed into the receiving body 15 or 29 so far that the End faces of the receiving body 15 or 29 and the insert »- piece in one and the same transverse plane.

In this design there is no plate 20, no reflective one End face 19 and not a reflective end face 28, but instead the light diffuser 14 has at the end which otherwise carries the plate 20, an axially perpendicular, to the sensor 17 'reflective forehead 37 - see Fig.l - on. - This everything can also be the case according to Fig.l to 3, so in the types without said insert.

According to Figure 4 and 5, the light measuring devices have a

hollow cylinder-like light diffuser 38 (FIG. 4) or 39 (FIG. 5) coaxial arrangement and two coaxial receiving bodies 40 and 41 or 42 and 43, in which the two ends of the light diffuser 38 and 39 are inserted. According to FIG. 4, the light measuring device also has a coaxial ring 44 surrounding the light diffuser 38 for shielding the sensor 17 from direct light from the root or the melt spot 13; the sensor 17 is provided close to the left in Figure 4 receiving body 40, and that on the 23 shielding ring located 44 and the _{au he} fd other axial side of the joining plane 23 receiving body located achssenkrechte point 41 one axial side of the joining plane surfaces, ie lying in transverse planes, reflective 45 and 46 facing each other. According to FIG. 5, however, the light measuring device has a coaxial hollow space surrounding the light diffuser 39

^ao cylinder 47 for the above-mentioned shield; the sensor 17, which according to FIGS. 4 and 5 is a photodiode, is provided near the receiving body 42 on the left in FIG. 5, and the two receiving bodies 42 and 43 have axially perpendicular, reflective surfaces 57 and 46 facing each other.

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The light measuring devices according to Flg.4 and 5 continue to show a hollow cylindrical, the light diffuser 38 or 39 on a whole length enveloping, optical filter 48 or 49 mentioned purpose, the shielding ring 44 is located between the filter 48 and the light diffuser 38 and the shielding hollow cylinder 47 surrounds the filter 49.

The light measuring devices according to Figure 4 and 5 have with the Receiving bodies 40 and 41 or 42 and 43 indirectly connected, radially extending, radially resilient Pressure pins 54 (not shown in Figure 4 for the sake of simplicity) for fitting or centering the light diffuser 38 or 39. of the light measuring device in the or opposite the tubes 10 and 11. For a flow of a named fluid through one another for the named purposes Different rooms of these light measuring devices have parts of the light measuring devices openings to the passage of the fluid. I.a. have O-rings 56 in this sense, which serve to fix the filter 48 and 49, not shown, and the receiving body 41 and 43 a axial point hole 58 in the area of an axial annular groove in which a light diffuser end is inserted.

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Claims (1)

• · · t «« «« t t «t irr · ι ·. <· L ·> e · -1- Utility model registration 6 83 37 771.9 M.A.N. MASCHINENFABRIK AUGSBUG-NORNBERG Aktfengesel 1 company gü / sd
5 Munich, June 24, 1985 Protection claims l. Device for regulating Schwaißvorgänge depending on the light emission from the weld root, consisting of an optical sensor, characterized in that the sensor (17) is connected to a light guide (16) in a contacting manner is, at the free end of a light diffuser (14, 38) is attached. 2. Apparatus according to claim 1, characterized in that the light diffuser (14, 38) supporting components at least are formed as a mirror (18, 19) on a surface facing the light diffuser. 3. Device for controlling welding processes 1n depending on the light emission from the weld seam root, consisting of an optical sensor, characterized in that a light diffuser (38, 39) is provided which at least partially surrounds the Sorsor (17). 7.2227 : i , K 15 20 25 SO 36 f «· · · * Γ · ft lit f Ψ% f »rri ti in -2- 4. Apparatus according to claim 3, characterized in that the light diffuser (38, 31) is hollow cylindrical and one end surrounds the sensor (17). 7.2227 3c April 1985