DE2441685A1 - METHOD AND DEVICE FOR MANUFACTURING ONE-PIECE FINED TUBES - Google Patents

Description

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dr. ing. H. NEGENDANK (-1973) dipl.-ing. H. HAUCK · bipi.-phys. W. SCHMITZ dipl.-ing. E. GRAALFS · dipl.-ing. W. WEHNERT

HAMBURG-MUNICH

DELIVERY ADDRESS; HAMBPB & 36 NEWER WAII 41

TEL. 30 74 28 XTND 36 4 115 TEXEGR. NEGETIAPATENT HAMBTTRG

MUNICH 15 MOZARTSTR. 23

TEL ·. 5 38 OS 80

TELEGR. NEGEDAPATENT MITNCH-EN

HAMBURG, ^ ^{en 2} 9.

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Method and device for manufacturing. one-piece finned tubes

The invention relates to a method and an apparatus for the production of finned tube, in which the finned too verse ^ ende tube rotated about a fixed axis and opposite one driven about an axis inclined to the RoHracv> se Form roller with a row of annular form projections, which successively increase in diameter, in axial direction Direction is moved, the axis of the forming roller one having a fixed distance from the pipe, such that the forming projections are in full working engagement, namely when "the Form roller is located at the intersection of the axes with the smallest possible distance from each other. .

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One-piece finned tubes have been produced by subjecting a length of tube to the action of a set of forming rollers became. Typically three are finned at equal intervals around a straight length of pipe is to be used aei forming rollers, each of which is disposed on a head which is substantially radially movable into and out of engagement with the tube. Any forming roller has a plurality of axially spaced apart, annular shaping projections which are stepped in diameter. the Axes of the spindles are inclined with respect to the pipe axis at an angle that corresponds to the angle of inclination of the pipe to be formed Ribs corresponds. The rollers are each rotated about their axes so that the tube is rotated and turned towards the larger becoming forming projections is advanced.

In this known device, when the rollers are moved radially inwardly into engagement with the pipe, the larger forming projections engage the pipe before the smaller forming projections. During the time required to move the rollers into full engagement, partial ribs of increasing depth are created. This conical zone of incomplete ribs has a length that depends mainly on the speed and the advance of the pipe. If multiple ribs are produced at high speed, these conical sections are longer than desired. The heat transfer capacity of such conical sections is of course less than optimal.

In addition, as a result of the fact that the larger

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First attack forming projections on the pipe, there is a tendency in the known device, the pipe with the leading, to stress large projections more heavily. In fact, the protrusions to be engaged first must be heavier work than normal during the advance of the intervention Rollers, which causes excessive material hardening and tends to trap metal behind the rollers. This metal is deformed in a localized zone by one initial, hump-shaped rib section larger than normal height to form, in addition, that the excessive hardening of the tube metal the stress of the following pre-cracks enlarged lower height.

The invention aims to remedy the aforementioned shortcomings of the known Procedure to overcome and an improved procedure as well as to create a device with the thin-walled tube with narrow rib spacings that are multi-threaded are to be produced at high speeds, whereby the transition cones should be short at the beginning of the work.

Another purpose of the invention is to provide an improved method and apparatus in which the aforementioned oversize of the rib diameter or the hump in port case, which are characteristic of the finned tube transition sections when they are with the known Devices are manufactured.

Another purpose is to create a procedure that can be done with simpler machines.

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An exemplary embodiment of the subject matter of the invention is to be described below in conjunction with the drawings will. Bs show:

Figure 1 is a top plan view of the apparatus used in connection with the invention, wherein a section of pipe to be finned and a forming roll in the home position are shown;

Fig. 2 is an elevation of the same in the starting position;

Figure 3 is a plan view of the roll and tube in the rolling position; and

Fig. 4 is an elevation of the roller and tube in Fig Rolling position.

With 10 a forming roller is designated quite generally, which in the illustrated case several disk sizes increasing in increments Has diameters whose circumferential sections engaging the workpiece are profiled in a known manner in order to achieve the To be processed pipe W increasingly deform in order to press Hippen outward from the drilling material. Five slices 11, 12, 13, 14 and 15 are shown, although a greater number are usually used. The details regarding the number and shape of the disks does not form part of the invention and, in fact, the annular, the workpiece deforming projections which form the peripheral portions of the disks, made in one piece from a solid roller will.

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As noted earlier, the ribbing process is typically three such processes are carried out Workpiece are arranged around. When engaging with the workpiece are the inclination of the forming disks to the axis and the Distance between the forming projections engaging the workpiece Discs in such a way that each disc following the leading disc causes an additional deformation of the tube in of the machined zone from the previous slice of the set. V / ie also known in the relevant technology, the discs and the inclination to the axis can be arranged in this way be that they form either a catchy rib or multiple, helical ribs. The multi-thread, helical rib method is preferred because it is a faster work allowed.

The pipe W to be machined can be mounted on an inner mandrel 16 in known way be supported.

All forming rollers in the set are arranged for simultaneous work »Only a single roller and spindle are shown, since all are the same V / ie can be seen from the drawing each roller mounted on a spindle S. The spindles are simultaneously rotatable synchronously in the same angular direction and cause a rotation and a feed of the workpiece as a result the frictional engagement between the rollers and the workpiece. Each of the spindles is supported on a fixed axis, but the spindles and the rollers arranged on them are in one straight path in the longitudinal direction of the spindle axes' movable to the rollers between a retracted or home pitch

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which is shown in FIGS. 1 and 2, in which they release the workpiece and the working position shown in FIGS. 3 and 4, in which they are in full effective engagement with the workpiece.

The workpiece is moving as you look at the drawing of right to left, while the reels from left to right be brought into engagement with the workpiece. As a result of the fact that the smaller protrusions come first with the workpiece come into engagement, there is no catching of metal, which was the case before and the stools mentioned formed. The transition between the smooth pipe section 20 (which can be used for connection purposes, for example), the is shown on the left in Fig. 4 and the subsequent one, with ribs provided pipe section 22 is abrupt. In addition to that, initially no excessive material hardening of the workpiece occurs, as is the case when the rollers are radially in Engagement with the workpiece.

When the desired rib length is finished, the rollers are moved back from the workpiece in the opposite direction to that of the handle feed (indicated by the arrow F in Jj'ig. 1) Starting position of Fig. 1 located rollers are ready for the next workpiece machining. Although the rollers could be withdrawn radially from the workpiece instead of moving along the same path as when they were engaged, that is, along the same line substantially perpendicular to the helix angle, it should be seen that a radial

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Pulling back would cause a "bevel effect" so that some incomplete ribs at the trailing end of the tube. were created.

In the known work feed arrangement in which the rollers are essentially radially in and out of engagement with the workpiece are moved, the elongation effect on the workpiece is different and considerable height forms of the butes occur until the rollers have reached their full working depth. at the inventive improved method, the feed rate of the rollers can be timed so that when the largest disc 15 reaches its full depth of engagement, the first zone touched by the smallest disk 11 reaches the largest disk. That way you can even that full height ribs practically from the point of the initial Touch to be generated. Furthermore, the material hardening increases gradually from Hull am initial point of contact to the full, inevitable degree of hardening caused by the subsequent rollers becomes, "excessive material hardening by the first engaging disc and trapping of metal will thus effectively switched off.

In the exemplary embodiment, the rollers are described as being driven and the itohr to be machined as being driven by the rollers, although it should be understood that this drive arrangement can be reversed, that is to say that the nohr can be rotated in order to rotate the 'rollers, in accordance with the principle äes operation remains in this .. all the same, but the machine construction is less convenient because the .ttohr (or rollers) they ¹ - · also move freely axially to the pipe ·

509830/0249

Claims (3)

O - patent a η s ρ r ü c h e 1.) Process for the production of finned tube, in which the tube to be provided with ribs rotated around a fixed axis and with respect to an axis that is inclined to the pipe axis Forming roller with a series of annular forming projections which successively increase in diameter, is moved in the axial direction, the axis of the forming roller at a fixed distance from the tube such that the forming projections are in full working engagement when the Form roller is located at the intersection of the axes with the smallest distance from each other, characterized in that the form roller in the longitudinal direction of its axis of rotation from an initial position in which the forming roller is out of engagement with the pipe into the Position of full working engagement is moved and held in this position while the forming roll and the tube are rotated synchronously about their axes, so that the pipe moves in the longitudinal direction of its axis relative to the forming roller, wherein the forming projections deform a helical section of the tube, and that the path of longitudinal movement the points of engagement of the forming projections with the pipe during the advance of the forming roll into full working engagement runs essentially at right angles to the slope angle, 2. The method according to claim 1, characterized in that the shaping projections along an increasing diameter the axis of rotation of the forming roller, which is directed away from the pipe when the forming roller is in the starting position - 9 509830/0249 is located so that a projection of the smallest diameter first air. Ro ¹ ^ r attacks, followed by the projections with successively increasing diameters., 3. The method according to claim 2, characterized in that that the forming roller is brought out of engagement with the pipe by moving it along its axis of rotation in the direction of the starting position is moved. 509830/0 2 49
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