Classifications

• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
  • C23C2/14—Removing excess of molten coatings; Controlling or regulating the coating thickness
  • C23C2/16—Removing excess of molten coatings; Controlling or regulating the coating thickness using fluids under pressure, e.g. air knives
  • C23C2/18—Removing excess of molten coatings from elongated material
  • C23C2/20—Strips; Plates

Definitions

• the invention relates to a device for
• Coating agent bath at least one adjustable guide roller is provided, with one downstream of the at least one guide roller, above the
• a device of this type is known from DE-PS 30 14 651. This known device is used for
• Metal especially zinc, coated metal tape
• the metal strip is guided into a bath with the liquid coating agent and is passed vertically upwards via a deflection roller arranged below the melting level.
• a deflection roller arranged below the melting level.
• Guide rollers arranged in the melt level in the coating agent bath serve to stabilize the belt by ensuring that the coating agent coated tape is as flat as possible when it emerges vertically upward from the coating agent bath and reaches the area of the blow-off nozzle pair.
• the strip is guided in such a way that it runs as centrally as possible through the opposing nozzle bodies of the blow-off nozzles each arranged on a metal strip side.
• Steel strip is known from European patent 0 249 234.
• the nozzle gap is formed by two mutually adjustable nozzle lips, so that the pressure of the blow-off medium acting on the metal strip surface can be adjusted.
• sensors are provided for measuring the layer thickness of the support on the metal strip, which sensors are connected to a computer, by means of whose output control valves are controlled, by means of which the amount of the blow-off medium with which the nozzle gap is acted on can be varied.
• the coating thickness can be reduced to one
• nozzle body is designed as a nozzle line in such a way that several separate from the direction of the nozzle gap
• the invention has for its object a
• this object is achieved in that at least one of the two nozzle bodies which can be adjusted relative to the metal strip has an optical measuring device for detecting the distance between the nozzle gap and
• the measuring beam with its optical axis is directed almost perpendicular to the metal strip surface and the output signal of the adjusting device for the guide roller and / or the adjusting device for the nozzle body can be fed such that the distance between the nozzle gap and the metal strip surface can be predetermined.
• the combination of the optical measuring device and the adjusting devices for the nozzle bodies or guide rollers forms a control loop arrangement which enables an accurate spatial
• Metal strip surface and nozzle gaps are kept constant so that a homogeneous coating is always achieved due to the central strip run even in the event of strip running errors, such as diagonally running or curved strip.
• the optical measuring device leads
• arranged nozzle body has a measuring device, since the positioning of the other nozzle body also in dependence on the distance measurement of the
• Measuring device can take place.
• a structurally simple solution provides that the measuring device is carried by the nozzle body. Due to the structural unit, changes in distance between the belt surface and the reference points of the optical measuring device which are related to the position of the nozzle gap can be corrected with high accuracy.
• each of the plurality of measuring devices is driven by a drive along one
• Guide carriage can be moved parallel to the nozzle gap.
• the measuring devices can be moved continuously along the nozzle gap, so that the metal strip surface can be easily scanned. If a separate drive is assigned to each measuring device, simple adaptation to different metal strip widths can take place, whereby in the case of two measuring devices each of the two measuring devices covers half of the bandwidth.
• the nozzle body can be moved transversely and / or rotationally in the normal plane of the metal strip by means of the adjustment drive.
• the transverse adjustment of the nozzle body comes into play when the position of the metal strip changes parallel to the nominal position, that is to say plane-parallel to the nozzle gap, so that the lateral movement of the nozzle body causes a change
• the rotational adjustment of the nozzle body comes into consideration if the strip is inclined at a certain angle in a plane perpendicular to the running direction, so that it would come into contact with the nozzle gap at the strip edges. This error can also be compensated for by appropriate positioning of the nozzle body.
• the nozzle body can be pivoted about an axis parallel to the nozzle gap, with a pivot angle which detects the pivot angle being used to correct the output signal of the at least one measuring device
• Angle correction device is provided. Such an angle corrector is required if, depending on the viscosity of the coating material
• Stripping conditions need to be changed during the process. Since in the case by pivoting the nozzle body about an axis running parallel to the nozzle gap of a measuring sensor fixedly arranged on the nozzle body, a distortion of the distance signal occurs, an electronic angle detection device is required to correct the above-mentioned error.
• Embodiment of the invention provided that a nozzle body with at least one measuring device is provided on each of the two metal strip sides, with a common evaluation device for the
• Measurement signals for the coupled control of the respective adjusting drives of the two nozzle bodies is assigned.
• the objective can be achieved in particular, a homogeneous coating of the
• Optical sensors that measure the distance from the sensor are preferably suitable as measuring devices
• the object on which the invention is based is achieved in that at least one of the two nozzle bodies which are adjustable relative to the metal strip carries an optical measuring device which can be moved parallel to the nozzle gap and overlaps at least the area of one edge of the metal strip and that the opposite nozzle body has a reflector has, on which the optical axis of the measuring device is directed in its position outside the metal strip edge.
• This variant is characterized in that an accurate distance measurement both in relation to the distance of the
• Nozzle band is determined in the area
• the nozzle bodies can now be positioned such that both nozzle bodies can be moved to a defined distance with respect to the metal strip, in particular that both
• Nozzle body are arranged symmetrically with respect to the band.
• Subsequent evaluation device which assigns the measurement signal to the current position on the travel axis and to a control loop for the adjusting device
• the evaluation device preferably has a
• Edge nozzles Such edge nozzles, as described in EP 0 219 234, are used to
• the position of the edge nozzle can also be set automatically in that one of the measuring devices detects the respective position of the metal strip edge.
• the measuring devices that detect the metal strip edge area can also be used for continuous monitoring of the actual metal strip width.
• the simplest embodiment of the second variant provides that two measuring devices are assigned to the one nozzle body, each of which can be moved over non-overlapping areas of at least half the metal bandwidth, each measuring device being movable by a separate drive.
• Measuring devices the function of distance measurement
• Measuring devices of separate drives move continuously parallel to the nozzle gap, measuring signals being obtained continuously or in certain time segments.
• Another embodiment provides instead of two individual measuring devices that the one nozzle body has two pairs of measuring devices, each with non-overlapping travel ranges, the
• Measuring devices of the first pair are movable over less than half the metal bandwidth and the
• Measuring devices of the second pair cover the area of the respective metal strip edge.
• the functions distance measurement nozzle-band, measurement of Transfer the metal band width or distance measurement from nozzle to nozzle to separate measuring devices, the first measuring devices for measuring the nozzle band always in
• Area within the belt edge and the second pairs of measuring devices always oscillate around the area of the belt edge and are moved by separate drives.
• each measuring device is arranged on a common guide carriage and each can be driven by separate drives, or, on the other hand, the measuring devices of the first or second pair lie on different nozzle bodies, the measuring devices which can be moved around the area of the metal strip edge on the reflector opposite nozzle body are arranged and here, too, each measuring device is adjustable by a separate drive.
• Both variants shown are technically equivalent, the latter being simpler to manufacture due to the non-overlapping drives.
• the reflector is preferably formed by a flat, in particular reflecting tape, running parallel to the metal tape, the width of which is selected such that
• Nozzle body must be readjusted, but also the optical measuring device, this is preferably attached to the nozzle body carrying it that a
• Compensating screw can be compensated.
• the optical measuring device is arranged on a traverse, with respect to which the associated nozzle body can be pivoted, the angular position of the remains
• Angle compensation can be dispensed with.
• Fig. 1 shows a first embodiment in section
• FIG. 2 shows the first embodiment as a top view in the normal plane of the metal strip, in the detail representing the blow-off unit,
• FIG. 3 shows a section along the line AA in FIG. 1,
• FIG. 4 shows a second exemplary embodiment as a plan view in the normal plane of the metal strip
• Fig. 5 is a section along the line BB in Fig.4 and
• Fig. 6 is a sketch to explain the function of the
• Fig. 6b an inclined position of the metal strip
• Fig. 7 shows a first embodiment as a plan view in the normal plane of the metal strip.
• Fig. 8 shows a second embodiment.
• Fig. 9 shows a section along the line AA in the
• Fig.10 a third embodiment, also
• FIG. 11 shows a section along the line B-B in FIG. 10
• Fig. 12 shows a fourth embodiment in section.
• Coating device shows a metal strip 1, which comes in at an angle from the top right
• the guide rollers 5 are arranged offset in height from each other and each separated by adjusting drives 12 in the direction perpendicular to
• coated metal strip 1 from the coating agent bath 15 and strikes two nozzle bodies 2 arranged on one side of the metal strip 1, the two
• Nozzle gaps 3 have a certain distance X from the respective metal strip surface.
• One of the nozzle bodies 2 carries an attachment for one on its upper side
• the measuring device 4 is an optical one Sensor that detects a beam of light along a
• the side of the measuring device 4 on which the light beam emerges is surrounded by a protective sleeve 7 which is pressurized with compressed air.
• FIG. 2 which shows a plan view of the detail from FIG. 1 which forms the region of the nozzle body 2
• two measuring devices 4a, 4b are provided along the width of the metal strip 1 and are arranged on a guide carriage 16 , wherein each of the measuring devices 4a, 4b can be moved separately in relation to the nozzle body 2 in a direction parallel to the width of the metal strip 1 or the nozzle gap 3 by means of an associated drive 17a, 17b.
• the two measuring devices 4a, 4b can be moved by means of the drives 17a, 17b so that the left one
• Metal strip 1 and the right measuring device 4b can be moved to the right edge of the metal strip.
• the entire attachment 8 on the nozzle body 2, which contains the measuring device 4, is by means of a
• Fenders 8a, 8b encapsulated.
• the adjustment drive for the nozzle body 2 consists of two linear drives 11, also shown in FIG. 2, the nozzle body being gimbal-mounted relative to the linear drives.
• the nozzle body 2 is laterally adjustable in the normal plane of the metal strip, so that the distance between the nozzle gap 3 and the surface of the metal strip can be changed.
• Nozzle body 2 rotatable in the normal plane of the metal strip 1.
• each nozzle body 2 can be pivoted about a pivot point 9 (see FIG. 3), so that the nozzle gap 3 into the
• an angle detection device 10 is provided, which the
• a shield plate 24 is provided above the nozzle gap 3, which is carried by the nozzle body 2 in the
• Nozzle gap 3 is inclined to prevent contact with the tape. This will load zinc
• optical measuring device which is sensitive to contamination
• the aim of the device according to the invention is the
• Measuring device and nozzle gap corresponds to the respective distance of the point on the nozzle gap from the metal strip surface, to one acting on the adjusting drives for the nozzle body or for the guide roller 5
• Middle position (dashed line) is offset parallel, e.g. in the direction of the upper nozzle gap of the upper
• the measuring devices 4a, 4b will determine the same reduction in distance, whereupon the upper nozzle body 2 is moved upward by means of the adjusting drive 11 in FIG. 6a by the desired value ⁇ the distance between the nozzle gap 3 and the metal strip surface 1
• the adjusting drive 11 of the lower nozzle body 2 also moves upward, so that the desired distance is achieved again as a result. If, according to FIG. 6b, the metal strip is inclined by a certain angle of inclination with respect to the central dashed position, the two measuring devices will each show different distances along the metal strip width, the setpoint of the distance being shown in the upper left area and in the lower right area of FIG. 6b between the nozzle gap and the metal strip surface. The correction is then carried out by rotating the respective nozzle bodies, as indicated by the circular arrows in FIG. 6b. After the correction has been made, the desired width is again the same for this tape running error
• Fig. 6c Another possible tape running error is indicated in Fig. 6c, which consists in that the tape 1 bulges. Due to the curvature, the permissible distance in the upper area, for example in the middle of the belt and in the lower area at the belt edges, is undershot, so that there is a risk of contact between the belt and the nozzle.
• this error is corrected in such a way that the upper nozzle body 2 moves laterally upwards until at least the desired value for the distance between the belt and the nozzle gap is maintained along the entire bandwidth. This means that this value is reached in the middle of the band, while at the
• the setting is made so that it moves away from the respective strip edges until the permissible distance is also reached there. The distance will then necessarily be larger in the middle.
• the device according to the invention provides, in addition to the above-described compensation of tape running errors, the possibility of the nozzle body 2 in relation to the
• Coating agent changes in the course of the process, so that the stripping conditions must be changed accordingly. Then the respective move
• Nozzle column 3 in the dashed position shown in Fig. 1. To occur due to the angle change
• Angle correction device 10 is provided. However, this is not necessary if the measuring devices 4a, 4b are not arranged in a stationary manner on the nozzle body 2, as disclosed in the exemplary embodiments shown in the drawings, but are accommodated in a separate structural unit.
• the measuring devices 4a, 4b shown in Fig. 2 can be easily in a changing width of the
• Metal strip 1 can be adjusted because they are independent
• the first exemplary embodiment of the second variant shown in FIG. 7 shows two nozzle bodies 2 arranged on one side of the metal strip 1 to be coated, the nozzle gaps of which are each at a certain distance x from the surface of the metal strip 1.
• the lower nozzle body 2 shown on the right in FIG. 9 has an attachment for the measuring device 4 on its upper side.
• the housing of the measuring device 4 consists of a
• Housing cover 8b and a rear housing part 8a which can be opened.
• the optical measuring device 4 rests on a carriage 16, on which it can be moved along the width of the metal strip 1.
• Measuring device 4 and housing 8a, 8b can be compared to the nozzle body 2 carrying them by means of a
• Angle of rotation can be adjusted. This is important when the nozzle body 2 rotatable about the pivot point 9 is adjusted and this angle is determined by the electronic angle detection 10.
• Each of the two nozzle bodies 2 can be moved in the normal plane shown in FIG. 7 by means of a drive 11 in the direction perpendicular to the transport direction of the metal strip 1.
• the adjustment drive consists of two linear drives 11,
• the nozzle body 2 can be adjusted laterally towards or away from the metal strip 1, so that the distance between
• Nozzle gap 3 and metal strip surface is changeable.
• Nozzle body 2 rotatable in the normal plane shown.
• two optical measuring devices 4 are provided along the width b of the metal strip, each measuring approximately half of the metal strip 1
• the device shown in FIG. 7 operates as follows:
• Each of the two measuring devices 4 is along the
• Measuring device 4 each the distance between the
• Metal band surface Shows itself in the course of the measurement within the travel path within the
• Metal band edges that the distance changes this means an inclination of the metal band in relation to the nozzle gap. This can be done by appropriate control the adjusting devices 11 or the guide rollers 5 in the "two or three roller system" (FIG. 1) are compensated.
• the measuring device 4 detects a deviation of the measured value from a predetermined value in the area outside the metal strip edges K, this is due to a change in the predetermined distance between the reference points of the two nozzle bodies 2. Knowing both the distance between the
• the second embodiment of the second variant of the invention shown in FIG. 8 differs from that described in that instead of two
• Measuring devices each covering more than the band half, four measuring devices are provided, of which the two inner ones are constantly in the position with ⁇ a
• the two outer measuring devices 4b oscillate within the range denoted by ⁇ b around the strip edges K, the measuring beam of the measuring devices 4b partly from
• FIGS. 10 and 11 differs from that of FIG. 2 only in that the oscillating in the edge region optical measuring devices 4b are not arranged on the common guide carriage of the nozzle body 2, which also carries the optical measuring devices 4a directed onto the metal strip. Rather, there is a further guide carriage 16 on the optical measuring devices 4b directed at the edge regions K
• the reflector is then provided on the nozzle body 2 which also carries the optical measuring devices 4a. The from the respective measuring devices
• each of the nozzle bodies 2 is to be rotated about the pivot point 9.
• the rotation of the nozzle body 2 is determined by an electronic angle detector 10. So that the optical axis everyone
• Measuring device 4a, 4b still falls vertically on the metal strip 1, the angular offset must be compensated for, namely by an angle compensation screw 20.
• Such an angle correction can also be carried out electronically by using the measurement signal of the angle detection 10 to position the compensation screw 20.
• the measuring device 4 does not rest directly on the nozzle body 2 but is on one
• Traverse 22 attached, along which the measuring device 4 can be moved transversely to the tape running direction.
• the traverse 22 can be adjusted with respect to the metal strip 1 by means of a crosshead drive 23.
• the cross member 22 is mounted in the area of the pivot point 9 for the nozzle body 2.
• the nozzle body 2 is rotatable at the pivot point 9 with respect to the crossmember 22, so that when the nozzle body 2 is rotated, it is dashed into that in FIG
• Nozzle body 2 is retained about the pivot point 9.
• a shield plate 24 is provided above the nozzle gap 3, which, carried by the nozzle body 2, runs essentially flat and is only slightly inclined in the direction of the nozzle gap 3 at its edge assigned to the metal strip to prevent contact with the tape.
• Contamination sensitive optical measuring device is protected.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Coating Apparatus (AREA)
• Length Measuring Devices By Optical Means (AREA)
• Coating With Molten Metal (AREA)
• Encapsulation Of And Coatings For Semiconductor Or Solid State Devices (AREA)
• Seal Device For Vehicle (AREA)
• Glass Compositions (AREA)

Applications Claiming Priority (7)

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• 1993
  • 1993-07-16 EP EP93915935A patent/EP0650534B2/fr not_active Expired - Lifetime
  • 1993-07-16 WO PCT/EP1993/001879 patent/WO1994002658A1/fr active IP Right Grant
  • 1993-07-16 AT AT93915935T patent/ATE144003T1/de active
  • 1993-07-16 DE DE59304141T patent/DE59304141D1/de not_active Expired - Lifetime

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