Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES, PROFILES OR LIKE SEMI-MANUFACTURED PRODUCTS OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
  • B21C37/00—Manufacture of metal sheets, rods, wire, tubes, profiles or like semi-manufactured products, not otherwise provided for; Manufacture of tubes of special shape
  • B21C37/06—Manufacture of metal sheets, rods, wire, tubes, profiles or like semi-manufactured products, not otherwise provided for; Manufacture of tubes of special shape of tubes or metal hoses; Combined procedures for making tubes, e.g. for making multi-wall tubes
  • B21C37/08—Making tubes with welded or soldered seams
  • B21C37/09—Making tubes with welded or soldered seams of coated strip material ; Making multi-wall tubes

Definitions

• the present invention relates to a method and an apparatus for producing molded by the so-called.
• Bundy method Doppel ⁇ wall pipes, particularly brake lines, fuel or hydraulic pipes in which one or both sides copper-plated steel strip directly to the winding subsequently on an inner tool in each case together with a pre-caliber and finished caliber, each consisting of a pair of form rollers and the internal tool on the outside, is shaped into a compact tube winding and is brazed under protective gas above the copper melting temperature (DE-PS 813 839).
• Such pipes formed from two or more pipe walls, represent safety parts because of their special properties, so that their use as a brake line, fuel pipes or hydraulic pipes is permitted even under statutory or state regulations.
• the prerequisites for the use mentioned above must therefore be created by the particularly good pipe quality, which basically means that a large number of parameters must be taken into account very strictly during manufacture. So affects e.g. the strip thickness with a constant outside diameter is 4 times the inside diameter.
• the dimensional tolerances and the strength of the tube winding are determined by the inner tool, the so-called float, in particular by the float diameter, the float traction, the float position and the like. influenced.
• the present invention is therefore based on the object of adhering to the manufacturing parameters more precisely than hitherto, i.e. by
• REPLACEMENT LEAF a compensation of the parameter changes quickly compensate so that the winding tube can be produced with a uniform and high quality. This adjustment should also be able to take place automatically.
• the object is achieved in connection with the features in the preamble of the main claim according to the invention in that the tube walls are pressed together by a first cold deformation applied via the inner tool in cooperation with the pairs of form rollers and that this pressing together of the tube walls is reinforced by a second cold deformation in such a way that a tensile force generated between a molded part and the pre-caliber on the one hand and the finished caliber on the other hand due to a tensile force controlled in a continuous manner by different roll speeds is transmitted to the tube winding.
• an extension exerted on the tube winding is set to 4-8%. On average, about 5-6% stretching can produce sufficient work hardening.
• the invention then also relates to a device for regulating an extension, which can be transferred to a double-wall tube formed by the so-called bundy method, in order to form a compact tube coil for subsequent soldering of the steel strip surfaces lying against one another, the tube coil between the inner tool and the pre-caliber frame on the one hand and a further inner tool and a finished caliber frame on the other hand is stretchable.
• the desired high quality which remains constant during the production process is achieved due to the device according to the invention in that the stretching between an incoming steel strip and the outgoing tube roll can be measured by means of sensors, and that an actual value measurement signal pending during setup can be stored is and in automatic operation of a hydraulic control as a basic value at a microprocessor and that a hydraulic linear drive for adjusting the position of the inner tool can be regulated or controlled via this or that the tensile force of the inner tool can be measured via a load cell in electronic control, that the actual value measurement signal pending during setup can be stored as a setpoint and is present in automatic mode for the setpoint / actual value comparison at a position controller and , via this, an electric linear drive for adjusting the position of the inner tool can be regulated or controlled.
• An improvement of the invention consists in that, via a separate drive for a finished-caliber roll stand, a regulated higher speed than in the other upstream molds
• REPLACEMENT LEAF roller stand drives is adjustable.
• the tensile force on the tube winding can thus be advantageously controlled.
• a drive alternative consists in that an adjustment gear is provided instead of the separate drive for the finished caliber roller stand.
• a further drive variant results from the fact that instead of the separate drive for the finished-caliber roller stand on this and the other form roller stand drives, a rigid gear with a fixed speed branching specification is provided.
• the linear drive for the position adjustment of the inner tool consists of a hydraulic or mechanical linear drive which is connected to a holder for the inner tool or for an inner tool force transducer.
• a control device is characterized by the following features: a) a load cell loaded via an internal tool pull rod, b) a force measurement amplifier which is assigned to the electromechanical servomotor, c) a first module for signal level adjustment, d) a Averaging device with a filter for the measurement signal, e) an inverter and a setpoint memory connected in parallel, f) a position controller for the inner tool and g) a signal amplifier that acts on the servomotor.
• a control device fulfills all the requirements for recording and processing the parameters mentioned.
• a further embodiment of the invention is created in that a counter and a setpoint adjuster are connected via a feedback connection connected in front of the signal output amplifier. are switched.
• Position setting of the inner tool can be determined.
• Another embodiment provides that on a switched between the position controller and SignalendverSystemr AND gate and a second module for signal level adjustment in the competent ⁇ the "machine” or “tape-end detection” the last an ⁇ standing actual value can be stored up to restart.
• control device can be designed electrically or electronically
• the linear drive which is hydraulic for the internal tool position adjustment
• the linear drive is connected to a pressure source via releasable check valves and a proportional valve, via the individual pipe
• the corresponding signals are supplied to a microprocessor as setpoints or as correction values, from which control deviations can be recognized and compensated for via a signal amplifier and the proportional valve, to parameters assigned to signal amplification modules and signal adaptation modules.
• 1 is a block diagram of a first control circuit in electro-mechanical design
• FIG. 2 is a block diagram of a second control circuit with a microprocessor, but in a hydraulic version,
• FIGS. 1 and 3 shows a further block diagram representation on an enlarged scale to supplement FIGS. 1 and
• FIG. 4 shows a partial section through the tube winding with an internal tool and with a pair of caliber rollers.
• Fig.l the device for pipe manufacturing by the so-called.
• Bundy process molded double wall pipes 1 is drawn in a central part of the block diagram.
• steel strip 2 copper-coated on one or both sides is unwound from a bundle 3 and formed to form the finished tube roll 8 by means of skiving rolls 4, forming rolls 5, pre-caliber rolls 6 and finished caliber rolls 7.
• a first phase the steel strip 2 is sharpened at the edges and then wound.
• the tube winding 8 is solidified and then brazing (this process step is not shown).
• the second phase requires an inner tool 9, which is also referred to in technical terms as a "float", which makes its function clear.
• the double wall pipe 1 has at least twice the wall thickness of the steel strip 2.
• the manufacturing method according to the invention is based on the fact that the tube walls (side surfaces of the steel strip 2) are pressed against one another by a first cold deformation applied via the inner tool 9 in cooperation with the scarfing rollers 4, the shaping rollers 5, the pre-caliber rollers 6 and the finished caliber rollers 7 and that this pressing together of the tube walls is reinforced by a second cold deformation in such a way that between a molded part (forming rollers 5) and the pre-caliber rollers 6, on the one hand, and the finished caliber (finished caliber rollers 7), on the other hand, is generated in a controlled manner in the course of the run due to different roller speeds ten tensile force is transmitted to the tube winding 8.
• the stretching exerted on the tube winding 8 should be 4-8%, on average 5-6%.
• the stretch is transmitted by a controlled tensile force to an inner tool pull rod 10, which is connected to the inner tool 9.
• the control device according to the invention is shown in two alternatives.
• the alternative according to Fig. 1 shows an electromechanical solution:
• the control device has a load cell 25 acted upon via the inner tool pull rod 10, furthermore a force measurement amplifier 26, a first module 27, an averager 28 with a filter for the measurement signal, an inverter 29, a setpoint memory 30 and a position controller 31.
• the actual value set via manual operation is stored as a setpoint and is pending in automatic mode for the setpoint-actual value comparison at the position control 31.
• a counter 34 and a setpoint adjuster 35 are connected via a feedback connection 33 connected in front of a signal output amplifier 32.
• a comparator 36 and an adjuster 37 are positive or negative limit values for the position setting of the inner tool 9.
• the last pending actual value which is available until a restart, can be stored in a second module 39 in the "machine off” or “tape end detection” states, switched between the position controller 31 and the signal output amplifier 32 thus remains resident.
• a signal is given to a strip thickness measuring amplifier as signal amplifier component 41, which is connected to the AND element 38.
• the tape thickness is displayed.
• the stretching is determined in a stretching measuring device 42 by means of the differential speed and displayed, using an incremental pulse generator as a measuring value transmitter 13 (strip inlet) and an incremental pulse generator 14 (pipe winding outlet). If the limit values set in the aforementioned measuring amplifiers are exceeded or undershot, a signal is forwarded to an OR logic element 43 and thereby triggers a warning message. After a time x the system is switched off.
• An inner tool adjusting device 44 has one
• a servomotor 16 for the position adjustment of the inner tool 9 is coupled to the mechanical linear drive 21.
• a solution C (FIG. 1) in the form of the separate drive 17 is designed. Furthermore, a solution B in the form of the adjusting gear 19 and then a solution A in the form of the rigid gear 20 with a fixed speed branch are available for use.
• a three-phase motor 46 for the separate drive 17 a three-phase motor 47 for driving the form roller stand drives 18, the adjustment gear 19 and the rigid gear 20 are arranged.
• An inverter 48 is assigned to the three-phase motor 46. The actual speed value is detected by a tachometer 49 and fed to the inverter 48.
• REPLACEMENT BUTT provided for the inner tool position adjustment and is part of an electro-hydraulic inner tool position control.
• a dash-dotted frame 52 shown on the right in FIG. 2 contains a complete hydraulic supply device with, inter alia, a pump 53 and a bladder accumulator 53a as the pressure source.
• the hydraulic linear drive 51 can be connected to the pressure source via unlockable check valves 54 and a proportional valve 55.
• the empirically determined parameters of the extension and the tensile force of the inner tool 9 assigned to the individual pipe dimensions are stored in a microprocessor 31a as setpoints.
• the position of the two internal tools 9 is set in accordance with these setpoints.
• the incremental pulse generators are activated as measured value transmitters 13 (tape inlet) and 14 (pipe winding outlet) and, with only a short delay, the control device for the inner tool 9.
• the stretch measurement value is fed to the microprocessor 31a via the stretch measurement device 42 and a signal adaptation module 59.3.
• the stretch measurement value represents the basic actual value of the control device.
• the two actual correction values are added or subtracted with this basic actual value and are supplied as a control deviation to a proportional valve amplifier as signal amplifier 60.
• the electrical signal is converted into a hydraulic signal and, via a hydraulic cylinder 62 controlled by the proportional valve 55, into a mechanical movement.
• the measuring amplifiers for the inner tool tensile force measurement, the strip thickness measurement and the elongation measurement can also be set
• REPLACEMENT LEAF Limit detectors are equipped, which initially trigger fault messages in the event of an overshoot or undershoot and then shut down the system after some time.
• the force measuring amplifier 26 intervenes here.
• the measurement signal of the force measurement amplifier 26 is supplied to the microprocessor 31a as a correction value during the pipe shaping via the force measurement amplifier 26 and a signal adaptation module 59.1. Deviations from the stored setpoint are offset against the extension control variable and the resulting control deviation is forwarded to the proportional valve amplifier 60. This control deviation is compensated for via the proportional valve 55 and the hydraulic linear drive 51.
• the strip thickness measurement is carried out continuously by means of the strip thickness measurement sensor 12.
• the measurement signal is fed to the microprocessor 31a as a further correction value via the band thickness measuring amplifier 41 and a signal adaptation module 59.2.
• An incremental pulse generator 56 detects the path between the strip thickness measurement sensor 12 and the desired position of the inner tool 9. After a delay determined in accordance with the production speed, the difference that occurs in relation to the desired strip thickness is applied as a correction value in the microprocessor 31a via a signal adjustment module 59.4.
• the two-stage cold-forming operation can be seen in FIG.
• the pre-caliber rolls 6 and the finished-caliber rolls 7 press the tube roll 8 radially together, the second stage of cold forming being carried out axially by pushing the inner tool 9 in the direction 63 or pulling it out in the direction 64.
• the inner tool 9 can be seen as a double cone 65a and 65b. To get the pulling force from
• the finished caliber rolls 7 have a roughened caliber form 66 which may be coated with a wear layer.
• the inner tool 9 it is also necessary for the inner tool 9 to prevent the tube winding 8 from escaping into the interior of the tube.
• the inner tool 9 forms, together with the aforementioned pre-caliber rolls 6 and finished-caliber rolls 7, a roll gap through which the wound double-wall pipe 1 is pulled by means of the roughened caliber form 66.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Control Of Metal Rolling (AREA)
• Bending Of Plates, Rods, And Pipes (AREA)

Applications Claiming Priority (2)

Publications (1)

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ID=6426020

Family Applications (1)

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Family Cites Families (4)

• 1991
  • 1991-02-27 DE DE19914106178 patent/DE4106178C1/de not_active Expired - Lifetime
• 1992
  • 1992-02-25 AU AU13275/92A patent/AU1327592A/en not_active Abandoned
  • 1992-02-25 EP EP19920905552 patent/EP0526614A1/de not_active Withdrawn
  • 1992-02-25 WO PCT/DE1992/000139 patent/WO1992015409A1/de active Application Filing
  • 1992-02-27 GB GB9204191A patent/GB2254025A/en not_active Withdrawn

Non-Patent Citations (1)

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