DE202013011975U1 - Apparatus for the production of steel barrels - Google Patents

Abstract

Device for producing longitudinally welded steel drums with a roller welding machine (10) with two welding rollers (18a, 18i) through which the cylindrical drum shells (16) pass while welding their overlapping ends in a longitudinal weld, characterized in that an infrared camera (22) for measuring the local welding temperature is arranged in the vicinity of the outer welding roller (18a).

Description

In the production of steel drums tubular casings for the cylindrical barrel coats are first formed from rectangular sheet metal blanks and then welded together the folded edges of the tubular casings via a longitudinal seam.

This longitudinal seam-welding of the cylindrical barrel shells is usually carried out by electrical resistance welding, the barrel shells going through a roller welding machine within a production line for the production of steel barrels. The quality of the welding depends essentially on the welding speed (roller speed) and the current intensity of the welding current. Among other things, these parameters determine the welding temperature in the weld seam. A resistance roller welding machine for longitudinal seams of Metallfassmänteln is z. B. from the document DE-A-1 124 167 known.

It has now been found that the correct and precisely consistent, d. H. Constant welding temperature is a good parameter for optimum welding quality.

Accordingly, it is an object of the present invention to maintain the weld quality and thus the quality of the finished steel barrel at a consistently high level, to reduce the reject rate and to ensure automatic, continuous online monitoring of the longitudinal seam welding.

This object is achieved in that the welding temperature is measured just behind the continuous welding point by means of an infrared camera for temperature measurement and this measured welding temperature is compared with a predetermined target value. The setpoint can be specified in a narrow bandwidth. As soon as the measured welding temperature runs out of the setpoint bandwidth or deviates from the specified setpoint value, individual welding parameters (such as the current intensity, the contact pressure of the welding rollers, the throughput speed or others) are changed until the measured welding temperature returns to the predetermined setpoint for optimum quality of the longitudinal weld coincides.

The use of infrared cameras to measure high temperatures is well known, such. B. from the steel industry, where in this way the temperature of the liquid molten steel is measured. The use of the measured temperatures in the longitudinal weld of welded barrel jackets for programmed online control of the welding process by targeted change of certain welding parameters is in contrast new and inventive.

In an apparatus for producing longitudinally welded steel drums with a roller welding machine with two welding rollers, the cylindrical barrel coats (Fasszargen, sheet steel sleeves) through and thereby their overlapping ends are welded in a longitudinal weld, the inventive construction is characterized in that In the vicinity of the outer welding roller, an infrared camera for measuring the local welding temperature is arranged. Preferably, the stationary arrangement of the infrared camera is aligned to the welding machine behind the outer welding roller at an angle of approximately 45 degrees to the direction of the welded barrel coats.

Best measurement results are achieved when the stationary arrangement of the infrared camera is arranged below the continuous barrel coats in the vicinity of the outer welding roller such that the measuring beam of the infrared camera is aligned at a point on the weld just behind the outlet of the welded barrel coats.

Appropriately, the infrared camera is to be aligned such that the measurement line or the measuring point impinges within a distance of less than 100 mm from the welding point between the welding rollers on the longitudinal weld of the expiring barrel casing.

For automation of the measuring arrangement, the infrared camera with an electronic control unit d. H. Recording and display device (= PC) connected. In order to be able to intervene on the welding parameters, the electronic control unit on the other side is also connected to the electronic unit or the power supply system of the roller welding machine.

In the device according to the invention, a cost-effective control and monitoring system for increasing the product quality in the production of steel drums is provided by using a commercially available infrared laser camera with an electronic recording and display device (PC). The arrangement or positioning of the infrared camera according to the invention leads with shortened response and reaction times to an improved precision of the measurement results and thus to an improvement of the barrel jacket welding process. The purpose of the device according to the invention is to detect and eliminate welding defects which can lead to micro-leaks (leaks). This can be a Conventional manual or visual control system with elaborate product destructive random sampling of individual steel barrels with sawing or cutting of welds can be saved or drastically reduced. With the device according to the invention, each steel drum produced is checked for an optimal and tight longitudinal weld. As a result, the number of Gutstück per layer is increased and it eliminates the destroyed by manual weld inspection barrels.

The measured values are visualized on a display of the PC and used to control the respective welding process. All data is fed to a control program and stored.

In the control program, a preselected range of the measured welding temperature (which, of course, is lower than directly in the welding spot) is specified as the setpoint range. There is a pre-alarm at high temperatures (T pre-max) above 1250 ° C and at lower temperatures (T pre-min) below 950 ° C. Full alarm occurs when an upper limit (T max) exceeds 1300 ° C and falls below a lower limit (T min) of 880 ° C. The optimum measuring temperature should then be around 1100 ° C.

If these temperature values in the weld at the measuring point are above or below these, there may be a welding defect and such a welded drum casing will be sorted out and examined, which could have led to this welding defect, such as: As impurities, oil residues, particles or the like. This error analysis is documented as an error history. As a rule, if the measuring temperatures are greater than T pre-max, the intensity of the welding current is somewhat reduced and, accordingly, slightly increased when the temperature drops below the measuring temperature T pre-min. With the present measuring method smallest temperature differences can be determined. On the measurement log, "red dot" marks can be set in relation to the position of the respective spot weld, in order to be able to locate and analyze the faulty weld on the barrel mantle. With the recorded error history, the detected welding errors can be effectively limited and reduced.

The invention will be described below with reference to the attached drawing 1 schematically illustrated embodiment described and described.

1 : with the reference number 10 is a common longitudinal seam welding machine referred to, the welded steel sheet sleeves (called after welding barrel shells) and thereby welded via two cooperating welding rollers (electrodes) by means of electrical resistance welding along their overlapping longitudinal edges.

The welding machine 10 is with a corresponding power supply unit 12 wired and is supplied by this with the required welding current.

With the arrow 14 is the direction of passage of the barrel shells to be welded 16 illustrated. At the end of the welding machine 10 go through the barrel coats 16 a pair of rollers with upper welding roller 18i and lower welding roller 18a , After the roll pass, the welding process for the longitudinal seam is complete and the finished welded drum shells 16 be from a conveyor belt or roller conveyor 20 transported away for further processing. Below the outer or lower welding roller 18a is an infrared camera 22 (Pyrometer) fixed but adjustable installed. The stationary arrangement of the infrared camera 22 at the welding machine 10 behind the outer welding roller 18a is with her measuring beam at an angle of approximately 45 degrees to the direction of the welded barrel coats 16 aligned to achieve optimal readings.

According to the invention, the arrangement of the infrared camera 22 just below the passing barrel coats 16 in the vicinity of the outer welding roller 18a set up such that the measuring beam of the infrared camera 22 on a fix point on the weld just behind the outlet of the welded barrel shells 16 is aligned. Preferably, the orientation of the infrared camera takes place 22 such that the measuring line or the measuring point (fixed point) is within a distance of less than 100 mm from the welding point between the welding rollers 18a . 18i on the longitudinal weld of the expiring barrel jacket 16 is aligned. For capturing, storing and evaluating the measured values, the infrared camera is used 22 with an electronic control unit 24 connected as a recording and display device (PC = personal computer). On the other side is the electronic control unit 24 continue via an electrical connection cable with the electronic unit 12 , ie the power supply system of the roller welding machine 10 connected.

• – Schweißfehler, die zu Mikro-Undichtigkeiten führen können zu erkennen bzw. zu ermitteln und zu eliminieren,
• – Verbesserung der bestehenden zeitaufwendigen und materialzerstörenden Qualitätskontrolle,
• – durch Beobachtung der Schweißtemperatur die Leistungsfähigkeit des Schweißprozesses zu erhöhen.

The measuring system includes behind the infrared camera a monitoring system with optical representation (screen presentation) of measured values and process parameters and a control and monitoring system with a personal computer (PC) for data evaluation and storage. The preprogrammed interaction of these components of the measuring system advantageously allows very short reaction and correction times. On the Screen (Display) errors are shown immediately This system aims to:

• - weld defects that can lead to micro-leaks to detect or detect and eliminate,
• - improving the existing time-consuming and material-destroying quality control,
• - To increase the performance of the welding process by observing the welding temperature.

Due to the savings of regularly performed manual weld checks by sawing or separating (= destroying) Musterfassmänteln as random samples, the low-cost investment for the fully automatic system according to the present invention has already fully paid for within a year.

LIST OF REFERENCE NUMBERS

10

welding machine

12

Power supply unit

14

Throughput direction

16

Barrel casing (= barrel frame)

18a

Welding roll outside - below

18i

Sweat roll in - up

20

Conveyor belt (= roller conveyor)

22

Infrared camera

24

PC control unit

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 1124167 A [0002]

Claims (7)

Device for producing longitudinally welded steel barrels with a roller welding machine ( 10 ) with two welding rollers ( 18a . 18i ), the cylindrical barrel shells ( 16 ) and thereby their overlapping ends are welded in a longitudinal weld, characterized in that in the vicinity of the outer welding roller ( 18a ) an infrared camera ( 22 ) is arranged for measuring the local welding temperature. Apparatus according to claim 1, characterized in that the stationary arrangement of the infrared camera ( 22 ) on the welding machine ( 10 ) behind the outer welding roller ( 18a ) at an angle of approximately 45 degrees to the running direction of the welded barrel shells ( 16 ) is aligned. Apparatus according to claim 1 or 2, characterized in that the stationary arrangement of the infrared camera ( 22 ) just below the passing barrel coats ( 16 ) in the vicinity of the outer welding roller ( 18a ) is arranged such that the measuring beam of the infrared camera ( 22 ) to a point on the weld just behind the outlet of the welded barrel shells ( 16 ) is aligned. Apparatus according to claim 1, 2 or 3, characterized in that the infrared camera ( 22 ) is aligned such that the measuring line or the measuring point within a distance of less than 100 mm from the welding point between the welding rollers ( 18a . 18i ) on the longitudinal weld of the expiring barrel shell ( 16 ) is aligned. Device according to claim 1, 2, 3 or 4, characterized in that the infrared camera ( 22 ) with an electronic control unit ( 24 ) is connected as a recording and display device (PC). Apparatus according to claim 1, 2, 3, 4 or 5, characterized in that the electronic control unit ( 24 ) with the electronic unit ( 12 ) (Power supply system of the roller welding machine ( 10 ) connected is. Device according to one of the preceding claims 1 to 6, characterized in that using the infrared camera ( 22 ) and the electronic control unit ( 24 ) as a recording and display device (PC) in the production of longitudinally welded steel drums whose welding temperature measured in the vicinity of the continuous welding point of the electrical resistance welding by means of the infrared camera and the measured welding temperature is continuously compared with a predetermined setpoint, and in deviation measured welding temperature is carried out a corresponding readjustment of individual welding parameters until the measured welding temperature again coincides with the specified value for optimum quality of the longitudinal weld.

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